2024-03-28T12:19:06Z
http://ir.lib.uwo.ca/do/oai/
oai:works.bepress.com:richard_philp-1000
2024-03-28T12:18:59Z
publication:richard_philp
oai:ir.lib.uwo.ca:physpharmpub-1000
2009-12-12T02:27:43Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:paedpub
18505471
Connexin Expression and Gap Junctional Coupling in Human Cumulus Cells: Contribution to Embryo Quality
Wang, Hong-Xing
Tong, Dan
El-Gehani, Faraj
Tekpetey, Francis R.
Kidder, Gerald M.
Article
2008-05-24T07:00:00Z
Gap junction
Conductance
Connexin43
Pregnancy
Journal of Cellular and Molecular Medicine
Journal of Cellular and Molecular Medicine
13
5
972
984
10.1111/j.1582-4934.2008.00373.x
Medical Physiology
Obstetrics and Gynecology
Gap junctional coupling among cumulus cells is important for oogenesis since its deficiency in mice leads to impaired folliculogenesis. Multiple connexins (Cx), the subunits of gap junction channels, have been found within ovarian follicles in several species but little is known about the connexins in human follicles. The aim of this study was to determine which connexins contribute to gap junctions in human cumulus cells and to explore the possible relationship between connexin expression and pregnancy outcome from in vitro fertilization (IVF). Cumulus cells were obtained from IVF patients undergoing intracytoplasmic sperm injection (ICSI). Connexin expression was examined by RT-PCR and confocal microscopy. Cx43 was quantified by immunoblotting and gap junctional coupling was measured by patch-clamp electrophysiology. All but five of 20 connexin mRNAs were detected. Of the connexin proteins detected, Cx43 forms numerous gap junction-like plaques but Cx26, Cx30, Cx30.3, Cx32, and Cx40 appeared to be
restricted to the cytoplasm. The strength of gap junctional conductance varied between
patients and was significantly and positively correlated with Cx43 level, but neither was correlated with patient age. Interestingly, Cx43 level and intercellular conductance were positively correlated with embryo quality as judged by cleavage rate and morphology, and were significantly higher in patients who became pregnant than in those who did not. Thus, despite the presence of multiple connexins, Cx43 is a major contributor to gap junctions in human cumulus cells and its expression level may influence pregnancy outcome after ICSI.
https://ir.lib.uwo.ca/physpharmpub/4
oai:ir.lib.uwo.ca:physpharmpub-1001
2009-11-15T15:06:29Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
19176884
A Dominant Loss-of-Function GJA1 (Cx43) Mutant Impairs Parturition in the Mouse
Tong, Dan
Lu, Xuerong
Wang, Hong-Xing
Plante, Isabelle
Lui, Ed
Laird, Dale W.
Bai, Donglin
Kidder, Gerald M.
Article
2009-06-01T07:00:00Z
Connexin43
Gap junction
Myometrium
Intercellular communication
Oculodentodigital dysplasia
ODDD
Biology of Reproduction
Biology of Reproduction
80
6
1099
1106
10.1095/biolreprod.108.071969
Medical Physiology
Obstetrics and Gynecology
Expression of GJA1 (commonly known as connexin43 or Cx43), a major myometrial gap junction protein, is upregulated before the onset of delivery, suggesting an essential role for Cx43-mediated gap junctional intercellular communication (GJIC) in normal uterine contraction during parturition. To determine how a disease-linked Cx43 mutation affects myometrial function, we studied a mutant mouse model carrying an autosomal dominant mutation (Gja1Jrt) in the gene encoding Cx43 that displays features of the human genetic disease oculodentodigital dysplasia. We found that Cx43 level, specifically the phosphorylated species of the protein, is significantly reduced in the myometrium of the mutant mice (Gja1Jrt/+), as revealed by Western blotting and immunostaining. Patch-clamp electrophysiological measurements demonstrated that coupling between myometrial smooth muscle cells is reduced to <15% of wild-type, indicating that the mutant protein acts dominantly on its wild-type counterpart. The phosphorylated species of Cx43 in the mutant myometrium failed to increase prior to parturition as well as in response to exogenous estrogen. Correspondingly, in vitro experiments with uterine strips revealed weaker contraction of the mutant myometrium and reduced responsiveness to oxytocin, providing an explanation for the prolonged gestation and presence of suffocated fetuses in the uteri that were observed in some of the mutant mice. We conclude that the Gja1Jrt mutation has a dominant-negative effect on Cx43 function in the myometrium, severely reducing GJIC, leading to impaired parturition.
https://ir.lib.uwo.ca/physpharmpub/3
oai:ir.lib.uwo.ca:physpharmpub-1003
2009-05-23T02:13:47Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:paedpub
19038973
Identification of WNT/β-CATENIN Signaling Pathway Components in Human Cumulus Cells
Wang, Hong-Xing
Tekpetey, Francis R.
Kidder, Gerald M.
Article
2009-01-01T08:00:00Z
Ovarian follicle
Paracrine signaling
Folliculogenesis
Gene expression
Signal transduction
Assisted reproduction
Molecular Human Reproduction
Molecular Human Reproduction
15
1
11
17
Medical Physiology
Obstetrics and Gynecology
Signaling via the conserved WNT/β-CATENIN pathway controls diverse developmental processes. To explore its potential role in the ovary, we investigated the expression of WNTs, frizzled (FZD) receptors and other pathway components in human cumulus cells obtained from oocytes collected for in vitro fertilization. Proteins were detected in cultured cells using immunofluorescence microscopy. Protein–protein interactions were analyzed by means of immunoprecipitation. WNT2, FZD2, FZD3 and FZD9 were identified but WNT1, WNT4 and FZD4 were not detected. WNT2 is co-expressed with FZD2, FZD3 and FZD9. Co-immunoprecipitation using WNT2 antibody demonstrated that WNT2 interacts with both FZD3 and FZD9, but only FZD9 antibody precipitated WNT2. We also identified DVL (disheveled), AXIN, GSK-3β (glycogen synthase kinase-3β) and β-CATENIN. β-CATENIN is concentrated in the plasma membranes. DVL co-localizes with FZD9 and AXIN in the membranes, but GSK-3β has little co-localization with AXIN and β-CATENIN. Interestingly, β-CATENIN is highly co-localized with FZD9 and AXIN. CDH1 (E-cadherin) was also detected in the plasma membranes and cytoplasm, co-localized with β-CATENIN, and CDH1 antibody precipitated β-CATENIN. The results suggest that WNT2 could act through its receptor FZD9 to regulate the β-CATENIN pathway in cumulus cells, recruiting β-CATENIN into plasma membranes and promoting the formation of adherens junctions involving CDH1.
Published in: Molecular Human Reproduction 2009 15(1):11-17; doi:10.1093/molehr/gan070
https://ir.lib.uwo.ca/physpharmpub/1
oai:ir.lib.uwo.ca:physpharmpub-1002
2009-05-23T02:06:54Z
publication:anatomy
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:paed
publication:pmid
publication:faculties
publication:anatomypub
publication:physpharm
publication:paedpub
19259389
Oogenesis Defects in a Mutant Mouse Model of Oculodentodigital Dysplasia
Tong, Dan
Colley, Deanne
Thoo, Renee
Li, Tony Y.
Plante, Isabelle
Laird, Dale W.
Bai, Donglin
Kidder, Gerald M.
Article
2009-03-01T08:00:00Z
Connexin43
Gap junction
Granulosa cell
Folliculogenesis
ODDD
Primordial germ cell
Oocyte maturation
Fertilization
Disease Models & Mechanisms
Disease Models & Mechanisms
2
3/4
157
167
Medical Physiology
Obstetrics and Gynecology
The essential role of connexin43 (Cx43) during oogenesis has been demonstrated by
the severe germ cell deficiency and arrested folliculogenesis observed in Cx43
knockout mice. Recently, another mutant mouse strain became available (Gja1Jrt/+) that
carries the dominant loss-of-function Cx43 mutation, Cx43G60S. Gja1Jrt/+ mice display
features of the human disease, oculodentodigital dysplasia (ODDD), caused by
mutations in the GJA1 gene. We have used this new mutant strain to study how a
disease-linked Cx43 mutant affects oogenesis. We found that female mutant mice are
subfertile with significantly reduced mating success and small litters. The
phosphorylated species of the Cx43 protein are reduced in the mutant ovaries in
association with impaired trafficking and assembly of gap junctions in the membranes
of granulosa cells, confirming that the mutant protein acts dominantly on its wild-type
counterpart. Correspondingly, although starting with normal abundance of germ cells,
ovaries of the mutant mice contain significantly fewer pre-ovulatory follicles and do
not respond to superovulation by gonadotropins, which is at least partially due to
reduced proliferation and increased apoptosis of granulosa cells. We conclude that the
Gja1Jrt mutation has a dominant negative effect on Cx43 function in the ovary,
rendering the females subfertile. Given these findings, closer examination of
reproductive function in ODDD human females is warranted.
Published in: Dis Model Mech. 2009 Mar–Apr; 2(3-4): 157–167. Published online 2009 February 23. doi: 10.1242/dmm.000935. PMCID: PMC2650217
https://ir.lib.uwo.ca/physpharmpub/2
oai:ir.lib.uwo.ca:physpharmpub-1004
2009-05-06T03:37:26Z
publication:animalpub
publication:animal
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:campusunits
19173746
The Retinoic Acid Binding Protein CRABP2 Is Increased in Murine Models of Degenerative Joint Disease
Welch, Ian D.
Cowan, Matthew F.
Beier, Frank
Underhill, Tully M.
Article
2009-01-28T08:00:00Z
Osteoarthritis
Degenerative joint disease
Medical Physiology
Introduction Osteoarthritis (OA) is a ebilitating disease with poorly defined aetiology. Multiple signals are involved in directing the formation of cartilage during development and the vitamin A derivatives, the retinoids, figure prominently in embryonic cartilage formation. In the present study, we examined the expression of a retinoid-regulated gene in murine models of OA.
Methods Mild and moderate forms of an OA-like degenerative disease were created in the mouse stifle joint by meniscotibial transection (MTX) and partial meniscectomy (PMX), respectively. Joint histopathology was scored using an Osteoarthritis Research Society International (OARSI) system and gene expression (Col1a1, Col10a1, Sox9 and Crabp2) in individual joints was determined using TaqMan quantitative PCR on RNA from microdissected articular knee cartilage.
Results For MTX, there was a significant increase in the joint score at 10 weeks (n = 4, p < 0.001) in comparison to sham surgeries. PMX surgery was slightly more severe and produced significant changes in joint score at six (n = 4, p < 0.01), eight (n = 4, p < 0.001) and 10 (n = 4, p < 0.001) weeks. The expression of Col1a1 was increased in both surgical models at two, four and six weeks post-surgery. In contrast, Col10a1 and Sox9 for the most part showed no significant difference in expression from two to six weeks post-surgery. Crabp2 expression is induced upon activation of the retinoid signalling pathway. At two weeks after surgery in the MTX and PMX animals, Crabp2 expression was increased about 18-fold and about 10-fold over the sham control, respectively. By 10 weeks, Crabp2 expression was increased about three-fold (n = 7, not significant) in the MTX animals and about five-fold (n = 7, p < 0.05) in the PMX animals in comparison to the contralateral control joint.
Conclusions Together, these findings suggest that the retinoid signalling pathway is activated early in the osteoarthritic process and is sustained during the course of the disease.
Published in: Arthritis Research & Therapy 2009, 11:R14 (doi:10.1186/ar2604). This article is online at: http://arthritis-research.com/content/11/1/R14
https://ir.lib.uwo.ca/physpharmpub/5
oai:ir.lib.uwo.ca:physpharmpub-1007
2009-05-06T03:35:35Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
18405384
The PI3K Pathway Regulates Endochondral Bone Growth through Control of Hypertrophic Chondrocyte Differentiation
Ulici, Veronica
Hoenselaar, Katie D.
Gillespie, J. Ryan
Beier, Frank
Article
2008-04-11T07:00:00Z
Endochondral ossification
PI3K
Chondrocyte differentiation
Medical Physiology
Background: The majority of our bones develop through the process of endochondral ossification that involves chondrocyte proliferation and hypertrophic differentiation in the cartilage growth plate. A large number of growth factors and hormones have been implicated in the regulation of growth plate biology, however, less is known about the intracellular signaling pathways involved. PI3K/Akt has been identified as a major regulator of cellular proliferation, differentiation and death in multiple cell types.
Results and Discussion: Employing an organ culture system of embryonic mouse tibiae and LY294002, a pharmacological inhibitor of PI3K, we show that inhibition of the pathway results in significant growth reduction, demonstrating that PI3K is required for normal endochondral bone growth in vitro. PI3K inhibition reduces the length of the proliferating and particularly of the hypertrophic zone. Studies with organ cultures and primary chondrocytes in micromass culture show delayed hypertrophic differentiation of chondrocytes and increased apoptosis in the presence of LY294002. Surprisingly, PI3K inhibition had no strong effect on IGF1-induced bone growth, but partially blocked the anabolic effects of C-type natriuretic peptide.
Conclusion: Our data demonstrate an essential role of PI3K signaling in chondrocyte differentiation and as a consequence of this, in the endochondral bone growth process.
Published in: BMC Developmental Biology 2008, 8:40 (doi:10.1186/1471-213X-8-40). The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-213X/8/40
https://ir.lib.uwo.ca/physpharmpub/8
oai:ir.lib.uwo.ca:physpharmpub-1006
2009-05-06T03:36:21Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
19014648
Connective Tissue Growth Factor Promoter Activity in Normal and Wounded Skin
Kapoor, Mohit
Liu, Shangxi
Huh, Kun
Parapuram, Sunil
Kennedy, Laura
Leask, Andrew
Article
2008-10-13T07:00:00Z
Connective tissue growth factor
Tissue repair
Myofibroblast
Medical Physiology
In skin, connective tissue growth factor (CTGF/CCN2) is induced during tissue repair. However,
what the exact cell types are that express CTGF in normal and wounded skin remain controversial.
In this report, we use transgenic knock-in mice in which the Pacific jellyfish Aequorea victoria
enhanced green fluorescent protein (E-GFP) gene has been inserted between the endogenous
CTGF promoter and gene. Unwounded (day 0) and wounded (days 3 and 7) skin was examined for
GFP to detect cells in which the CTGF promoter was active, α-smooth muscle actin (α-SMA) to
detect myofibroblasts, and NG2 expression to detect pericytes. In unwounded mice, CTGF
expression was absent in epidermis and was present in a few cells in the dermis. Upon wounding,
CTGF expression was induced in the dermis. Double immunolabeling revealed that CTGFexpressing
cells also expressed α-SMA, indicating the CTGF was expressed in myofibroblasts. A
subset (~30%) of myofibroblasts were also NG2 positive, indicating that pericytes significantly
contributed to the number of myofibroblasts in the wound. Pericytes also expressed CTGF.
Collectively, these results indicate that CTGF expression in skin correlates with myofibroblast
induction, and that CTGF-expressing pericytes are significant contributors to myofibroblast activity
during cutaneous tissue repair.
Published in: Fibrogenesis & Tissue Repair 2008, 1:3 (doi:10.1186/1755-1536-1-3). The electronic version of this article is the complete one and can be found online at: http://www.fibrogenesis.com/content/1/1/3
https://ir.lib.uwo.ca/physpharmpub/7
oai:ir.lib.uwo.ca:physpharmpub-1008
2009-05-06T03:35:02Z
publication:robartspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:robarts
publication:institutes
17284317
Forced Mobilization Accelerates Pathogenesis: Characterization of a Preclinical Surgical Model of Osteoarthritis
Appleton, C Thomas G.
McErlain, David D.
Pitelka, Vasek
Schwartz, Neil
Bernier, Suzanne M.
Henry, James L.
Holdsworth, David W.
Beier, Frank
Article
2007-02-06T08:00:00Z
Preclinical osteoarthritis
Articular cartilage degradation
Subchondral bone sclerosis
Medical Physiology
Preclinical osteoarthritis (OA) models are often employed in
studies investigating disease-modifying OA drugs (DMOADs).
In this study we present a comprehensive, longitudinal
evaluation of OA pathogenesis in a rat model of OA, including
histologic and biochemical analyses of articular cartilage
degradation and assessment of subchondral bone sclerosis.
Male Sprague-Dawley rats underwent joint destabilization
surgery by anterior cruciate ligament transection and partial
medial meniscectomy. The contralateral joint was evaluated as a
secondary treatment, and sham surgery was performed in a
separate group of animals (controls). Furthermore, the effects of
walking on a rotating cylinder (to force mobilization of the joint)
on OA pathogenesis were assessed. Destabilization-induced
OA was investigated at several time points up to 20 weeks after
surgery using Osteoarthritis Research Society International
histopathology scores, in vivo micro-computed tomography
(CT) volumetric bone mineral density analysis, and biochemical
analysis of type II collagen breakdown using the CTX II
biomarker. Expression of hypertrophic chondrocyte markers was also assessed in articular cartilage. Cartilage degradation,
subchondral changes, and subchondral bone loss were
observed as early as 2 weeks after surgery, with considerable
correlation to that seen in human OA. We found excellent
correlation between histologic changes and micro-CT analysis
of underlying bone, which reflected properties of human OA,
and identified additional molecular changes that enhance our
understanding of OA pathogenesis. Interestingly, forced
mobilization exercise accelerated OA progression. Minor OA
activity was also observed in the contralateral joint, including
proteoglycan loss. Finally, we observed increased chondrocyte
hypertrophy during pathogenesis. We conclude that forced
mobilization accelerates OA damage in the destabilized joint.
This surgical model of OA with forced mobilization is suitable for
longitudinal preclinical studies, and it is well adapted for
investigation of both early and late stages of OA. The time
course of OA progression can be modulated through the use of
forced mobilization.
Published in: Arthritis Research & Therapy 2007, 9:R13 (doi:10.1186/ar2120). The electronic version of this article is the complete one and can be found online at: http://arthritis-research.com/content/9/1/R13
https://ir.lib.uwo.ca/physpharmpub/9
oai:ir.lib.uwo.ca:physpharmpub-1005
2009-05-06T03:36:55Z
publication:physpharmpub
publication:faculties
publication:physpharm
Abelson Tyrosine Kinase Links PDGFbeta Receptor Activation to Cytoskeletal Regulation of NMDA Receptors in CA1 Hippocampal Neurons
Beazely, Michael A.
Weerapura, Manjula
MacDonald, John F.
Article
2008-12-12T08:00:00Z
PDGF receptor
Cytoskeletal dynamics
Hippocampal neuron
Medical Physiology
Background: We have previously demonstrated that PDGF receptor activation indirectly inhibits N-methyl-D-aspartate (NMDA) currents by modifying the cytoskeleton. PDGF receptor ligand is also neuroprotective in hippocampal slices and cultured neurons. PDGF receptors are tyrosine kinases that control a variety of signal transduction pathways including those mediated by PLCγ. In fibroblasts Src and another non-receptor tyrosine kinase, Abelson kinase (Abl), control PDGF receptor regulation of cytoskeletal dynamics. The mechanism whereby PDGF receptor regulates cytoskeletal dynamics in central neurons remains poorly understood.
Results: Intracellular applications of active Abl, but not heat-inactivated Abl, decreased NMDAevoked currents in isolated hippocampal neurons. This mimics the effects of PDGF receptor activation in these neurons. The Abl kinase inhibitor, STI571, blocked the inhibition of NMDA currents by Abl. We demonstrate that PDGF receptors can activate Abl kinase in hippocampal neurons via mechanisms similar to those observed previously in fibroblasts. Furthermore, PDGFβ receptor activation alters the subcellular localization of Abl. Abl kinase is linked to actin cytoskeletal dynamics in many systems. We show that the inhibition of NMDA receptor currents by Abl kinase is blocked by the inclusion of the Rho kinase inhibitor, Y-27632, and that activation of Abl correlates with an increase in ROCK tyrosine phosphorylation.
Conclusion: This study demonstrates that PDGFβ receptors act via an interaction with Abl kinase and Rho kinase to regulated cytoskeletal regulation of NMDA receptor channels in CA1 pyramidal neurons.
Published in: Molecular Brain 2008, 1:20 (doi:10.1186/1756-6606-1-20). The electronic version of this article is the complete one and can be found online at: http://www.molecularbrain.com/content/1/1/20
https://ir.lib.uwo.ca/physpharmpub/6
oai:ir.lib.uwo.ca:physpharmpub-1009
2009-05-06T03:34:32Z
publication:physpharmpub
publication:faculties
publication:physpharm
Correction: Forced Mobilization Accelerates Pathogenesis: Characterization of a Preclinical Surgical Model of Osteoarthritis
Appleton, C Thomas G.
McErlain, David D.
Pitelka, Vasek
Schwartz, Neil
Bernier, Suzanne M.
Henry, James L.
Holdsworth, David W.
Beier, Frank
Article
2008-09-22T07:00:00Z
Preclinical osteoarthritis
Articular cartilage degradation
Subchondral bone sclerosis
Medical Physiology
Published in: Arthritis Research & Therapy 2008, 10:407 (doi:10.1186/ar2513).
https://ir.lib.uwo.ca/physpharmpub/10
oai:ir.lib.uwo.ca:physpharmpub-1010
2009-05-06T03:20:45Z
publication:physpharmpub
publication:surgerypub
publication:faculties
publication:physpharm
publication:surgery
Viable Group A Streptococci in Macrophages during Acute Soft Tissue Infection
Thulin, Pontus
Johansson, Linda
Low, Donald E.
Gan, Bing S.
Kotb, Malak
McGeer, Allison
Norrby-Teglund, Anna
Article
2006-01-17T08:00:00Z
Group A streptococcus
Streptococcal soft tissue infection
Medical Physiology
Background: Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells.
Methods and Findings: We characterized in vivo interactions between group A streptococci (GAS) and cells involved in innate immune responses, using human biopsies (n = 70) collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria.
Conclusions: This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis of streptococcal soft tissue infections highlights a need for alternative therapeutic strategies.
Published in: Thulin P, Johansson L, Low DE, Gan BS, Kotb M, et al. (2006) Viable Group A Streptococci in Macrophages during Acute Soft Tissue Infection. PLoS Med 3(3): e53. doi:10.1371/journal.pmed.0030053
https://ir.lib.uwo.ca/physpharmpub/11
oai:ir.lib.uwo.ca:psychologypub-1003
2009-05-16T00:36:44Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:psychologypub
publication:psychology
18431477
Distinct Haptic Cues Do Not Reduce Interference When Learning to Reach in Multiple Force Fields
Cothros, Nicholas
Wong, Jeremy
Gribble, Paul L.
Article
2008-04-23T07:00:00Z
Force field learning
Haptic cue
Motor skill
Cognitive Psychology
Neurosciences
Background: Previous studies of learning to adapt reaching movements in the presence of novel forces show that learning
multiple force fields is prone to interference. Recently it has been suggested that force field learning may reflect learning to
manipulate a novel object. Within this theoretical framework, interference in force field learning may be the result of static
tactile or haptic cues associated with grasp, which fail to indicate changing dynamic conditions. The idea that different
haptic cues (e.g. those associated with different grasped objects) signal motor requirements and promote the learning and
retention of multiple motor skills has previously been unexplored in the context of force field learning.
Methodology/Principle Findings: The present study tested the possibility that interference can be reduced when two
different force fields are associated with differently shaped objects grasped in the hand. Human subjects were instructed to
guide a cursor to targets while grasping a robotic manipulandum, which applied two opposing velocity-dependent curl
fields to the hand. For one group of subjects the manipulandum was fitted with two different handles, one for each force
field. No attenuation in interference was observed in these subjects relative to controls who used the same handle for both
force fields.
Conclusions/Significance: These results suggest that in the context of the present learning paradigm, haptic cues on their
own are not sufficient to reduce interference and promote learning multiple force fields.
Published as: Cothros N, Wong J, Gribble PL (2008) Distinct Haptic Cues Do Not Reduce Interference when Learning to Reach in Multiple Force Fields. PLoS ONE 3(4): e1990. doi:10.1371/journal.pone.0001990
https://ir.lib.uwo.ca/psychologypub/4
oai:ir.lib.uwo.ca:anatomypub-1000
2009-05-23T00:15:13Z
publication:anatomy
publication:physpharmpub
publication:dentistrypub
publication:pmid
publication:faculties
publication:anatomypub
publication:physpharm
publication:dentistry
19144181
Egr-1 Inhibits the Expression of Extracellular Matrix Genes in Chondrocytes by TNFα-induced MEK/ERK Signalling
Rockel, Jason S.
Bernier, Suzanne M.
Leask, Andrew
Article
2009-01-14T08:00:00Z
TNF?
Mitogen-activated kinase kinase
Extracellular regulated kinase
Early growth response 1
Osteoarthritis
Rheumatoid arthritis
Arthritis Research & Therapy
11
R8
Cell Anatomy
Cell and Developmental Biology
Introduction TNFα is increased in the synovial fluid of patients
with rheumatoid arthritis and osteoarthritis. TNFα activates
mitogen-activated kinase kinase (MEK)/extracellular regulated
kinase (ERK) in chondrocytes; however, the overall functional
relevance of MEK/ERK to TNFα-regulated gene expression in
chondrocytes is unknown.
Methods Chondrocytes were treated with TNFα with or without
the MEK1/2 inhibitor U0126 for 24 hours. Microarray analysis
and real-time PCR analyses were used to identify genes
regulated by TNFα in a MEK1/2-dependent fashion. Promoter/
reporter, immunoblot, and electrophoretic mobility shift assays
were used to identify transcription factors whose activity in
response to TNFα was MEK1/2 dependent. Decoy
oligodeoxynucleotides bearing consensus transcription factor
binding sites were introduced into chondrocytes to determine
the functionality of our results.
Results Approximately 20% of the genes regulated by TNFα in
chondrocytes were sensitive to U0126. Transcript regulation of
the cartilage-selective matrix genes Col2a1, Agc1 and Hapln1,
and of the matrix metalloproteinase genes Mmp-12 and Mmp-9,
were U0126 sensitive – whereas regulation of the inflammatory
gene macrophage Csf-1 was U0126 insensitive. TNFα-induced
regulation of Sox9 and NFKB activity was also U0126
insensitive. Conversely, TNFα-increased early growth response
1 (Egr-1) DNA binding was U0126 sensitive. Transfection of
chondrocytes with cognate Egr-1 oligodeoxynucleotides
attenuated the ability of TNFα to suppress Col2a1, Agc1 or
Hapln1 mRNA expression.
Conclusions Our results suggest that MEK/ERK and Egr1 are
required for TNFα-regulated catabolic and anabolic genes of the
cartilage extracellular matrix, and hence may represent potential
targets for drug intervention in osteoarthritis or rheumatoid
arthritis.
Published in: Arthritis Research & Therapy 2009, 11:R8 (doi:10.1186/ar2595). The electronic version of this article is the complete one and can be found online at: http://arthritis-research.com/content/11/1/R8
https://ir.lib.uwo.ca/anatomypub/1
oai:ir.lib.uwo.ca:physpharmpub-1011
2011-09-06T02:19:35Z
publication:robartspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:robarts
publication:institutes
19079541
Connectivity of the Primate Superior Colliculus Mapped by Concurrent Microstimulation and Event-Related fMRI
Field, Courtney B.
Johnston, Kevin
Gati, Joseph S.
Menon, Ravi S.
Everling, Stefan
Article
2008-12-11T08:00:00Z
Superior colliculus
Neuroanatomical studies
PLoS ONE
PLoS ONE
3
12
e3928
e3928
http://dx.doi.org/10.1371/journal.pone.0003928
Bioimaging and Biomedical Optics
Medical Physiology
Neuroscience and Neurobiology
<p>Background: Neuroanatomical studies investigating the connectivity of brain areas have heretofore employed procedures in which chemical or viral tracers are injected into an area of interest, and connected areas are subsequently identified using histological techniques. Such experiments require the sacrifice of the animals and do not allow for subsequent electrophysiological studies in the same subjects, rendering a direct investigation of the functional properties of anatomically identified areas impossible. Methodology/Principal Findings: Here, we used a combination of microstimulation and fMRI in an anesthetized monkey preparation to study the connectivity of the superior colliculus (SC). Microstimulation of the SC resulted in changes in the blood oxygenation level-dependent (BOLD) signals in the SC and in several cortical and subcortical areas consistent with the known connectivity of the SC in primates. Conclusions/Significance: These findings demonstrates that the concurrent use of microstimulation and fMRI can be used to identify brain networks for further electrophysiological or fMRI investigation.</p>
https://ir.lib.uwo.ca/physpharmpub/12
oai:ir.lib.uwo.ca:surgerypub-1004
2009-05-30T01:00:50Z
publication:physpharmpub
publication:surgerypub
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:surgery
Identification of differentially expressed genes in fibroblasts derived from patients with Dupuytren's Contracture
Satish, Latha
LaFramboise, William A.
O'Gorman, David B.
Johnson, Sandra
Janto, Benjamin
Gan, Bing Siang
Baratz, Mark E.
Hu, Fen Z.
Post, J. Christopher
Ehrlich, Garth D.
Kathju, Sandeep
Article
2008-04-23T07:00:00Z
Dupuytren's contracture
Significance Analysis of Microarrays
BMC Medical Genomics
1
Medical Genetics
Medical Physiology
Surgery
Dupuytren's contracture (DC) is the most common inherited connective tissue disease of humans and is hypothesized to be associated with aberrant wound healing of the palmar fascia. Fibroblasts and myofibroblasts are believed to play an important role in the genesis of DC and the fibroproliferation and contraction that are hallmarks of this disease. This study compares the gene expression profiles of fibroblasts isolated from DC patients and controls in an attempt to identify key genes whose regulation might be significantly altered in fibroblasts found within the palmar fascia of Dupuytren's patients. Total RNA isolated from diseased palmar fascia (DC) and normal palmar fascia (obtained during carpal tunnel release; 6 samples per group) was subjected to quantitative analyses using two different microarray platforms (GE Code Link™ and Illumina™) to identify and validate differentially expressed genes. The data obtained was analyzed using The Significance Analysis of Microarrays (SAM) software through which we identified 69 and 40 differentially regulated gene transcripts using the CodeLink™ and Illumina™ platforms, respectively. The CodeLink™ platform identified 18 upregulated and 51 downregulated genes. Using the Illumina™ platform, 40 genes were identified as downregulated, eleven of which were identified by both platforms. Quantitative RT-PCR confirmed the downregulation of three high-interest candidate genes which are all components of the extracellular matrix: proteoglycan 4 (PRG4), fibulin-1 (FBLN-1) transcript variant D, and type XV collagen alpha 1 chain. Overall, our study has identified a variety of candidate genes that may be involved in the pathophysiology of Dupuytren's contracture and may ultimately serve as attractive molecular targets for alternative therapies.
Published in: BMC Medical Genomics 2008, 1:10 (doi:10.1186/1755-8794-1-10). The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1755-8794/1/10
https://ir.lib.uwo.ca/surgerypub/5
oai:ir.lib.uwo.ca:physpharmpub-1012
2009-07-28T00:08:10Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
17116261
Dexamethasone stimulates expression of C-type Natriuretic Peptide in chondrocytes
Agoston, Hanga
Baybayan, Laurie
Beier, Frank
Article
2006-11-20T08:00:00Z
Dexamethasone
C-type Natriuretic Peptide
glucocorticoid
chondrocyte
BMC Musculoskeletal Disorders
BMC Musculoskeletal Disorders
7
87
Dentistry
Medical Biochemistry
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Background: Growth of endochondral bones is regulated through the activity of cartilaginous growth
plates. Disruption of the physiological patterns of chondrocyte proliferation and differentiation – such as in
endocrine disorders or in many different genetic diseases (e.g. chondrodysplasias) – generally results in
dwarfism and skeletal defects. For example, glucocorticoid administration in children inhibits endochondral
bone growth, but the molecular targets of these hormones in chondrocytes remain largely unknown. In
contrast, recent studies have shown that C-type Natriuretic Peptide (CNP) is an important anabolic
regulator of cartilage growth, and loss-of-function mutations in the human CNP receptor gene cause
dwarfism. We asked whether glucocorticoids could exert their activities by interfering with the expression
of CNP or its downstream signaling components.
Methods: Primary mouse chondrocytes in monolayer where incubated with the synthetic glucocorticoid
Dexamethasone (DEX) for 12 to 72 hours. Cell numbers were determined by counting, and real-time PCR
was performed to examine regulation of genes in the CNP signaling pathway by DEX.
Results: We show that DEX does influence expression of key genes in the CNP pathway. Most
importantly, DEX significantly increases RNA expression of the gene encoding CNP itself (Nppc). In
addition, DEX stimulates expression of Prkg2 (encoding cGMP-dependent protein kinase II) and Npr3
(natriuretic peptide decoy receptor) genes. Conversely, DEX was found to down-regulate the expression
of the gene encoding its receptor, Nr3c1 (glucocorticoid receptor), as well as the Npr2 gene (encoding the
CNP receptor).
Conclusion: Our data suggest that the growth-suppressive activities of DEX are not due to blockade of
CNP signaling. This study reveals a novel, unanticipated relationship between glucocorticoid and CNP
signaling and provides the first evidence that CNP expression in chondrocytes is regulated by endocrine
factors.
Published in: BMC Musculoskeletal Disorders 2006, 7:87. doi: 10.1186/1471-2474-7-87
https://ir.lib.uwo.ca/physpharmpub/13
oai:ir.lib.uwo.ca:biochempub-1018
2009-07-25T20:37:01Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:surgery
publication:biochem
A Novel Mass Spectrometry-based Assay for GSK-3β Activity
Bowley, Erin
Mulvihill, Erin
Howard, Jeffrey C.
Pak, Brian J.
Gan, Bing Siang
O'Gorman, David B.
Article
2005-12-16T08:00:00Z
kinase assay
Glycogen Synthase Kinase-3beta activity
BMC Biochemistry
6
29
Biochemistry
Medical Physiology
Surgery
Background: As a component of the progression from genomic to proteomic analysis, there is a need for accurate assessment of protein post-translational modifications such as phosphorylation. Traditional kinase assays rely heavily on the incorporation of γ-P32 radiolabeled isotopes, monoclonal anti-phospho-protein antibodies, or gel shift analysis of substrate proteins. In addition to the expensive and time consuming nature of these methods, the use of radio-ligands imposes restrictions based on the half-life of the radionucleotides and pose potential health risks to researchers. With the shortcomings of traditional assays in mind, the aim of this study was to develop a high throughput, non-radioactive kinase assay for screening Glycogen Synthase Kinase-3beta (GSK-3β) activity.
Results: Synthetic peptide substrates designed with a GSK-3β phosphorylation site were assayed with both recombinant enzyme and GSK-3β immunoprecipitated from NIH 3T3 fibroblasts. A molecular weight shift equal to that of a single phosphate group (80 Da.) was detected by surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) in a GSK-3β target peptide (2B-Sp). Not only was there a dose-dependent response in molecular weight shift to the amount of recombinant GSK-3β used in this assay, this shift was also inhibited by lithium chloride (LiCl), in a dose-dependent manner.
Conclusion: We present here a novel method to sensitively measure peptide phosphorylation by GSK-3β that, due to the incorporation of substrate controls, is applicable to either purified enzyme or cell extracts. Future studies using this method have the potential to elucidate the activity of GSK-3β in vivo, and to screen enzyme activity in relation to a variety of GSK-3β related disorders.
Published in: BMC Biochemistry 2005, 6:29. doi:10.1186/1471-2091-6-29
https://ir.lib.uwo.ca/biochempub/18
oai:ir.lib.uwo.ca:physpharmpub-1013
2011-03-17T02:50:18Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
17374144
C-type Natriuretic Peptide Regulates Endochondral Bone Growth through p38 MAP Kinase-dependent and – Independent Pathways
Agoston, Hanga
Khan, Sameena
James, Claudine G
Gillespie, J. Ryan
Serra, Rosa
Stanton, Lee-Anne
Beier, Frank
Article
2007-03-20T07:00:00Z
C-type natriuretic peptide
Endochondral bone growth
Skeletal disease
BMC Developmental Biology
BMC Developmental Biology
7
18
http://dx.doi.org/10.1186/1471-213X-7-18
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Background: C-type natriuretic peptide (CNP) has recently been identified as an important anabolic regulator of endochondral bone growth, but the molecular mechanisms mediating its effects are not completely understood. Results: We demonstrate in a tibia organ culture system that pharmacological inhibition of p38 blocks the anabolic effects of CNP. We further show that CNP stimulates endochondral bone growth largely through expansion of the hypertrophic zone of the growth plate, while delaying mineralization. Both effects are reversed by p38 inhibition. We also performed Affymetrix microarray analyses on micro-dissected tibiae to identify CNP target genes. These studies confirmed that hypertrophic chondrocytes are the main targets of CNP signaling in the growth plate, since many more genes were regulated by CNP in this zone than in the others. While CNP receptors are expressed at similar levels in all three zones, cGMP-dependent kinases I and II, important transducers of CNP signaling, are expressed at much higher levels in hypertrophic cells than in other areas of the tibia, providing a potential explanation for the spatial distribution of CNP effects. In addition, our data show that CNP induces the expression of NPR3, a decoy receptor for natriuretic peptides, suggesting the existence of a feedback loop to limit CNP signaling. Finally, detailed analyses of our microarray data showed that CNP regulates numerous genes involved in BMP signaling and cell adhesion. Conclusion: Our data identify novel target genes of CNP and demonstrate that the p38 pathway is a novel, essential mediator of CNP effects on endochondral bone growth, with potential implications for understanding and treatment of numerous skeletal diseases.</p>
https://ir.lib.uwo.ca/physpharmpub/14
oai:ir.lib.uwo.ca:nursingpub-1050
2009-08-25T22:58:43Z
publication:fammedpub
publication:fammed
publication:physpharmpub
publication:paed
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:nursing
publication:nursingpub
publication:paedpub
18845069
Rural Women and Pharmacologic Therapy: Needs and Issues in Rural Canada
Leipert, Beverly
Matsui, Doreen
Wagner, Jessica
Rieder, Michael J.
Article
2008-01-01T08:00:00Z
Rural woman
pharmacologic therapy
Canada
Canadian Journal of Rural Medicine
Canadian Journal of Rural Medicine
13
4
171
179
Nursing
Introduction: The needs and issues of rural women regarding pharmacologic information and therapy are rarely explored. We sought to explore the needs and issues of rural women in Canada regarding drug-related information and prescription and nonprescription pharmaceuticals.
Methods: We used the qualitative methodology of interpretive description. In-depth semistructured face-to-face interviews were conducted with 20 women aged 17–88 years who lived in rural southwestern Ontario.
Results: Although rural women accessed prescription medications, complementary and alternative medicine (CAM) was highly favoured, and alcohol and illicit drugs such as marijuana, crystal meth and cocaine were prevalent in rural communities. Factors that affected rural women's decisions about which medications to use included access to health care practitioners, costs of medications, experiences of family members and friends with prescribed and alternative medications, attitudes and approaches of health care providers and health store employees, and the women's own expectations and desires. Factors that affected the use of illicit drugs included availability, boredom, peer pressure and cultural norms. Rural factors that influenced access to drug information and use included presence or lack of confidential care, distance to resources, and presence, accessibility and acceptability of rural resources.
Conclusion: Rural women use a variety of drug therapies and sources of information, and experience unique socioeconomic and environmental issues that affect access to appropriate drug-related information and therapies. Further research is needed to clarify and articulate pharmacologic needs, issues and solutions for women in diverse rural settings.
https://ir.lib.uwo.ca/nursingpub/46
oai:ir.lib.uwo.ca:physpharmpub-1014
2009-08-04T23:04:04Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
17927818
Src Kinase Inhibition Promotes the Chondrocyte Phenotype
Bursell, Laura
Woods, Anita
James, Claudine G.
Pala, Daphne
Leask, Andrew
Beier, Frank
Article
2007-10-10T07:00:00Z
Animals
Cell Differentiation
Cell Line
Cell Shape
Cells
Cultured
Chondrocytes
Female
Mice
Phenotype
Pregnancy
Protein Kinase Inhibitors
src-Family Kinases
Arthritis Research & Therapy
Arthritis Research & Therapy
9
R105
Medical Physiology
Musculoskeletal, Neural, and Ocular Physiology
Regulated differentiation of chondrocytes is essential for both normal skeletal development and maintenance of articular cartilage. The intracellular pathways that control these events are incompletely understood, and our ability to modulate the chondrocyte phenotype in vivo or in vitro is therefore limited. Here we examine the role played by one prominent group of intracellular signalling proteins, the Src family kinases, in regulating the chondrocyte phenotype. We show that the Src family kinase Lyn exhibits a dynamic expression pattern in the chondrogenic cell line ATDC5 and in a mixed population of embryonic mouse chondrocytes in high-density monolayer culture. Inhibition of Src kinase activity using the pharmacological compound PP2 (4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo [3,4-d]pyrimidine) strongly reduced the number of primary mouse chondrocytes. In parallel, PP2 treatment increased the expression of both early markers (such as Sox9, collagen type II, aggrecan and xylosyltransferases) and late markers (collagen type X, Indian hedgehog and p57) markers of chondrocyte differentiation. Interestingly, PP2 repressed the expression of the Src family members Lyn, Frk and Hck. It also reversed morphological de-differentiation of chondrocytes in monolayer culture and induced rounding of chondrocytes, and reduced stress fibre formation and focal adhesion kinase phosphorylation. We conclude that the Src kinase inhibitor PP2 promotes chondrogenic gene expression and morphology in monolayer culture. Strategies to block Src activity might therefore be useful both in tissue engineering of cartilage and in the maintenance of the chondrocyte phenotype in diseases such as osteoarthritis.
Published in: Arthritis Research & Therapy, 2007, 9:R105. doi: 10.1186/ar2308
https://ir.lib.uwo.ca/physpharmpub/15
oai:ir.lib.uwo.ca:physpharmpub-1016
2009-08-11T00:10:30Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16984628
The Transcription Factor ATF3 is Upregulated During Chondrocyte Differentiation and Represses Cyclin D1 and A Gene Transcription
James, Claudine G.
Woods, Anita
Underhill, T. Michael
Beier, Frank
Article
2006-09-19T07:00:00Z
Actins
Activating Transcription Factor 3
Animals
Cell Differentiation
Cells
Cultured
Chondrocytes
Core Binding Factor Alpha 1 Subunit
Cyclic AMP Response Element-Binding Protein
Cyclin A
Cyclin D1
Cytochalasin D
Female
High Mobility Group Proteins
Male
Mice
Models
Biological
Mutation
Oligonucleotide Array Sequence Analysis
Pregnancy
Promoter Regions
Genetic
RNA
Messenger
Response Elements
SOX9 Transcription Factor
Transcription Factors
Transcription
Genetic
BMC Molecular Biology
BMC Molecular Biology
7
30
Medical Physiology
Molecular Biology
Background: Coordinated chondrocyte proliferation and differentiation are required for normal endochondral bone growth. Transcription factors binding to the cyclicAMP response element (CRE) are known to regulate these processes. One member of this family, Activating Transcription Factor 3 (ATF3), is expressed during skeletogenesis and acts as a transcriptional repressor, but the function of this protein in chondrogenesis is unknown.
Results: Here we demonstrate that Atf3 mRNA levels increase during mouse chondrocyte differentiation in vitro and in vivo. In addition, Atf3 mRNA levels are increased in response to cytochalasin D treatment, an inducer of chondrocyte maturation. This is accompanied by increased Atf3 promoter activity in cytochalasin D-treated chondrocytes. We had shown earlier that transcription of the cell cycle genes cyclin D1 and cyclin A in chondrocytes is dependent on CREs. Here we demonstrate that overexpression of ATF3 in primary mouse chondrocytes results in reduced transcription of both genes, as well as decreased activity of a CRE reporter plasmid. Repression of cyclin A transcription by ATF3 required the CRE in the cyclin A promoter. In parallel, ATF3 overexpression reduces the activity of a SOX9-dependent promoter and increases the activity of a RUNX2-dependent promoter.
Conclusion: Our data suggest that transcriptional induction of the Atf3 gene in maturing chondrocytes results in down-regulation of cyclin D1 and cyclin A expression as well as activation of RUNX2-dependent transcription. Therefore, ATF3 induction appears to facilitate cell cycle exit and terminal differentiation of chondrocytes.
Published in: BMC Molecular Biology, 2006, 7:30. doi: 10.1186/1471-2199-7-30
https://ir.lib.uwo.ca/physpharmpub/17
oai:ir.lib.uwo.ca:physpharmpub-1015
2009-08-07T00:11:15Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
17603917
Expression Profiling of Dexamethasone-treated Primary Chondrocytes Identifies Targets of Glucocorticoid Signalling in Endochondral Bone Development
James, Claudine G.
Ulici, Veronica
Tuckermann, Jan
Underhill, T. Michael
Beier, Frank
Article
2007-07-01T07:00:00Z
Animals
Bone Development
Bone and Bones
Cartilage
Chondrocytes
Dexamethasone
Gene Expression Profiling
Gene Expression Regulation
Developmental
Glucocorticoids
Mice
Oligonucleotide Array Sequence Analysis
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Time Factors
Tissue Distribution
BMC Genomics
BMC Genomics
8
205
Medical Physiology
Background: Glucocorticoids (GCs) are widely used anti-inflammatory drugs. While useful in clinical practice, patients taking GCs often suffer from skeletal side effects including growth retardation in children and adolescents, and decreased bone quality in adults. On a physiological level, GCs have been implicated in the regulation of chondrogenesis and osteoblast differentiation, as well as maintaining homeostasis in cartilage and bone. We identified the glucocorticoid receptor (GR) as a potential regulator of chondrocyte hypertrophy in a microarray screen of primary limb bud mesenchyme micromass cultures. Some targets of GC regulation in chondrogenesis are known, but the global effects of pharmacological GC doses on chondrocyte gene expression have not been comprehensively evaluated.
Results: This study systematically identifies a spectrum of GC target genes in embryonic growth plate chondrocytes treated with a synthetic GR agonist, dexamethasone (DEX), at 6 and 24 hrs. Conventional analysis of this data set and gene set enrichment analysis (GSEA) was performed. Transcripts associated with metabolism were enriched in the DEX condition along with extracellular matrix genes. In contrast, a subset of growth factors and cytokines were negatively correlated with DEX treatment. Comparing DEX-induced gene expression data to developmental changes in gene expression in micromass cultures revealed an additional layer of complexity in which DEX maintains the expression of certain chondrocyte marker genes while inhibiting factors that promote vascularization and ultimately ossification of the cartilaginous template.
Conclusion: Together, these results provide insight into the mechanisms and major molecular classes functioning downstream of DEX in primary chondrocytes. In addition, comparison of our data with microarray studies of DEX treatment in other cell types demonstrated that the majority of DEX effects are tissue-specific. This study provides novel insights into the effects of pharmacological GC on chondrocyte gene transcription and establishes the foundation for subsequent functional studies.
Published in: BMC Genomics, 2007, 8:205. doi: 10.1186/1471-2164-8-205
https://ir.lib.uwo.ca/physpharmpub/16
oai:ir.lib.uwo.ca:physpharmpub-1017
2010-09-09T02:05:20Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
15634359
Sicily Statement on Evidence-based Practice
Dawes, Martin
Summerskill, William
Glasziou, Paul
Cartabellotta, Antonino
Martin, Janet
Hopayian, Kevork
Porzsolt, Franz
Burls, Amanda
Osborne, James
Article
2005-01-05T08:00:00Z
Adult
Clinical Competence
Curriculum
Decision Making
Educational Measurement
Evidence-Based Medicine
Health Personnel
Humans
Information Storage and Retrieval
Middle Aged
Program Development
Teaching
BMC Medical Education
BMC Medical Education
5
1
http://dx.doi.org/10.1186/1472-6920-5-1
Epidemiology
Medical Physiology
Public Health
Background: A variety of definitions of evidence-based practice (EBP) exist. However, definitions are in themselves insufficient to explain the underlying processes of EBP and to differentiate between an evidence-based process and evidence-based outcome. There is a need for a clear statement of what Evidence-Based Practice (EBP) means, a description of the skills required to practise in an evidence-based manner and a curriculum that outlines the minimum requirements for training health professionals in EBP. This consensus statement is based on current literature and incorporating the experience of delegates attending the 2003 Conference of Evidence-Based Health Care Teachers and Developers ("Signposting the future of EBHC").
Discussion: Evidence-Based Practice has evolved in both scope and definition. Evidence-Based Practice (EBP) requires that decisions about health care are based on the best available, current, valid and relevant evidence. These decisions should be made by those receiving care, informed by the tacit and explicit knowledge of those providing care, within the context of available resources.Health care professionals must be able to gain, assess, apply and integrate new knowledge and have the ability to adapt to changing circumstances throughout their professional life. Curricula to deliver these aptitudes need to be grounded in the five-step model of EBP, and informed by ongoing research. Core assessment tools for each of the steps should continue to be developed, validated, and made freely available.
Summary: All health care professionals need to understand the principles of EBP, recognise EBP in action, implement evidence-based policies, and have a critical attitude to their own practice and to evidence. Without these skills, professionals and organisations will find it difficult to provide 'best practice'.
https://ir.lib.uwo.ca/physpharmpub/18
oai:ir.lib.uwo.ca:physpharmpub-1018
2009-08-18T23:43:22Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
17214902
Mouse Preimplantation Embryo Responses to Culture Medium Osmolarity Include Increased Expression of CCM2 and p38 MAPK Activation
Fong, Barry
Watson, Patricia H.
Watson, Andrew J.
Article
2007-01-10T08:00:00Z
Animals
Blastocyst
Cells
Cultured
Culture Media
Enzyme Activation
Female
Fluorescent Antibody Technique
Indirect
Gene Expression
Mice
Microfilament Proteins
Microscopy
Confocal
Osmolar Concentration
Phosphorylation
Pregnancy
Reverse Transcriptase Polymerase Chain Reaction
p38 Mitogen-Activated Protein Kinases
BMC Developmental Biology
BMC Developmental Biology
7
2
Medical Physiology
Obstetrics and Gynecology
Background: Mechanisms that confer an ability to respond positively to environmental osmolarity are fundamental to ensuring embryo survival during the preimplantation period. Activation of p38 mitogen-activated protein kinase (MAPK) occurs following exposure to hyperosmotic treatment. Recently, a novel scaffolding protein called Osmosensing Scaffold for MEKK3 (OSM) was linked to p38 MAPK activation in response to sorbitol-induced hypertonicity. The human ortholog of OSM is cerebral cavernous malformation 2 (CCM2). The present study was conducted to investigate whether CCM2 is expressed during mouse preimplantation development and to determine whether this scaffolding protein is associated with p38 MAPK activation following exposure of preimplantation embryos to hyperosmotic environments.
Results: Our results indicate that Ccm2 along with upstream p38 MAPK pathway constituents (Map3k3, Map2k3, Map2k6, and Map2k4) are expressed throughout mouse preimplantation development. CCM2, MAP3K3 and the phosphorylated forms of MAP2K3/MAP2K6 and MAP2K4 were also detected throughout preimplantation development. Embryo culture in hyperosmotic media increased p38 MAPK activity in conjunction with elevated CCM2 levels.
Conclusion: These results define the expression of upstream activators of p38 MAPK during preimplantation development and indicate that embryo responses to hyperosmotic environments include elevation of CCM2 and activation of p38 MAPK.
Published in: BMC Developmental Biology, 2007, 7:2. doi: 10.1186/1471-213X-7-2
https://ir.lib.uwo.ca/physpharmpub/19
oai:ir.lib.uwo.ca:obsgynpub-1000
2009-08-20T00:20:45Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:pmid
publication:faculties
publication:physpharm
12646061
Responsiveness of Bovine Cumulus-Oocyte-Complexes (COC) to Porcine and Recombinant Human FSH, and the Effect of COC Quality on Gonadotropin Receptor and Cx43 Marker Gene mRNAs During Maturation In Vitro
Calder, Michele D.
Caveney, Anita N.
Smith, Lawrence C.
Watson, Andrew J.
Article
2003-02-11T08:00:00Z
Animals
Cattle
Connexin 43
Culture Media
Serum-Free
Dose-Response Relationship
Drug
Estradiol
Female
Follicle Stimulating Hormone
Humans
Oocytes
Oogenesis
Ovarian Follicle
RNA
Messenger
Receptors
FSH
Receptors
LH
Recombinant Proteins
Swine
Reproductive Biology and Endocrinology
Reproductive Biology and Endocrinology
1
14
Medical Physiology
Obstetrics and Gynecology
Substantially less development to the blastocyst stage occurs in vitro than in vivo and this may be due to deficiencies in oocyte competence. Although a large proportion of bovine oocytes undergo spontaneous nuclear maturation, less is known about requirements for proper cytoplasmic maturation. Commonly, supraphysiological concentrations of FSH and LH are added to maturation media to improve cumulus expansion, fertilization and embryonic development. Therefore, various concentrations of porcine FSH (pFSH) and recombinant human FSH (rhFSH) were investigated for their effect on bovine cumulus expansion in vitro. Expression of FSHr, LHr and Cx43 mRNAs was determined in cumulus-oocyte complexes to determine whether they would be useful markers of oocyte competence. In serum-free media, only 1000 ng/ml pFSH induced marked cumulus expansion, but the effect of 100 ng/ml pFSH was amplified in the presence of 10% serum. In contrast, cumulus expansion occurred with 1 ng/ml rhFSH in the absence of serum. FSHr mRNA was highest at 0-6 h of maturation, then abundance decreased. Similarly, Cx43 mRNA expression was highest from 0-6 h but decreased by 24 h of maturation. However, the relative abundance of LHr mRNA did not change from 6-24 h of maturation. Decreased levels of FSHr, LHr and Cx43 mRNAs were detected in COCs of poorer quality. In conclusion, expansion of bovine cumulus occurred at low doses of rhFSH in serum-free media. In summary, FSHr, LHr and Cx43 mRNA abundance reflects COC quality and FSHr and Cx43 mRNA expression changes during in vitro maturation; these genes may be useful markers of oocyte developmental competence.
Published in: Reproductive Biology and Endocrinology, 2003, 1:14. doi: 10.1186/1477-7827-1-14
https://ir.lib.uwo.ca/obsgynpub/1
oai:ir.lib.uwo.ca:biochempub-1024
2009-08-21T22:04:54Z
publication:fammedpub
publication:fammed
publication:robartspub
publication:physpharmpub
publication:brescia
publication:pmid
publication:affiliates
publication:faculties
publication:physpharm
publication:bresciafoodnutritionalsciences
publication:biochempub
publication:foodpub
publication:robarts
publication:biochem
publication:institutes
11063434
HDL-cholesterol-raising Effect of Orange Juice in Subjects with Hypercholesterolemia
Kurowska, Elzbieta M.
Spence, J. David
Jordan, John
Wetmore, Stephen
Freeman, David J.
Piché, Leonard A.
Serratore, Paula
Article
2000-11-01T08:00:00Z
Adult
Aged
Ascorbic Acid
Beverages
Body Mass Index
Cholesterol
HDL
Cholesterol
LDL
Citrus
Energy Intake
Female
Folic Acid
Homocysteine
Humans
Hypercholesterolemia
Male
Middle Aged
Nutritional Physiological Phenomena
Triglycerides
American Journal of Clinical Nutrition
72
5
1095
1100
Biochemistry
Food Science
Medicine and Health Sciences
Nutrition
Background: Orange juice-a rich source of vitamin C, folate, and flavonoids such as hesperidin-induces hypocholesterolemic responses in animals.
Objective: We determined whether orange juice beneficially altered blood lipids in subjects with moderate hypercholesterolemia.
Design: The sample consisted of 16 healthy men and 9 healthy women with elevated plasma total and LDL-cholesterol and normal plasma triacylglycerol concentrations. Participants incorporated 1, 2, or 3 cups (250 mL each) of orange juice sequentially into their diets, each dose over a period of 4 wk. This was followed by a 5-wk washout period. Plasma lipid, folate, homocyst(e)ine, and vitamin C (a compliance marker) concentrations were measured at baseline, after each treatment, and after the washout period.
Results: Consumption of 750 mL but not of 250 or 500 mL orange juice daily increased HDL-cholesterol concentrations by 21% (P: < 0.001), triacylglycerol concentrations by 30% (from 1.56 +/- 0.72 to 2.03 +/- 0.91 mmol/L; P: < 0.02), and folate concentrations by 18% (P: < 0.01); decreased the LDL-HDL cholesterol ratio by 16% (P: < 0.005); and did not affect homocyst(e)ine concentrations. Plasma vitamin C concentrations increased significantly during each dietary period (2.1, 3.1, and 3.8 times, respectively).
Conclusions: Orange juice (750 mL/d) improved blood lipid profiles in hypercholesterolemic subjects, confirming recommendations to consume >/=5-10 servings of fruit and vegetables daily.
https://ir.lib.uwo.ca/biochempub/23
oai:ir.lib.uwo.ca:nursingpub-1124
2009-09-07T00:02:45Z
publication:fammedpub
publication:fammed
publication:physpharmpub
publication:paed
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:nursing
publication:nursingpub
publication:paedpub
Women and Pharmacologic Therapy in Rural and Remote Canada
Leipert, Beverly D.
Matsui, Doreen
Rieder, Michael J.
Article
2006-10-01T07:00:00Z
Adolescent
Aged
Community Pharmacy Services
Complementary Therapies
Female
Health Services Accessibility
Humans
Medical Errors
Patient Education as Topic
Physician's Practice Patterns
Pregnancy
Pregnancy in Adolescence
Rural Health Services
Women's Health
Canadian Journal of Rural Medicine
Canadian Journal of Rural Medicine
11
4
296
300
Nursing
https://ir.lib.uwo.ca/nursingpub/65
oai:ir.lib.uwo.ca:surgerypub-1006
2009-09-16T00:32:03Z
publication:mnipub
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:mni
publication:biochem
publication:surgery
12866952
Elevated Levels of β-catenin and Fibronectin in Three-dimensional Collagen Cultures of Dupuytren's Disease Cells are Regulated by Tension in Vitro
Howard, Jeffrey C.
Varallo, Vincenzo M.
Ross, Douglas C.
Roth, James H.
Faber, Kenneth J.
Alman, Benjamin
Gan, Bing Siang
Article
2003-07-16T07:00:00Z
Biomechanics
Cells
Cultured
Collagen
Cytoskeletal Proteins
Dupuytren's Contracture
Fibroblasts
Fibronectins
Humans
Trans-Activators
beta Catenin
BMC Musculoskeletal Disorders
4
16
Surgery
Background: Dupuytren's contracture or disease (DD) is a fibro-proliferative disease of the hand that results in the development of scar-like, collagen-rich disease cords within specific palmar fascia bands. Although the molecular pathology of DD is unknown, recent evidence suggests that beta-catenin may play a role. In this study, collagen matrix cultures of primary disease fibroblasts show enhanced contraction and isometric tension-dependent changes in beta-catenin and fibronectin levels.
Methods: Western blots of beta-catenin and fibronectin levels were determined for control and disease primary cell cultures grown within stressed- and attached-collagen matrices. Collagen contraction was quantified, and immunocytochemistry analysis of filamentous actin performed.
Results: Disease cells exhibited enhanced collagen contraction activity compared to control cells. Alterations in isometric tension of collagen matrices triggered dramatic changes in beta-catenin and fibronectin levels, including a transient increase in beta-catenin levels within disease cells, while fibronectin levels steadily decreased to levels below those seen in normal cell cultures. In contrast, both fibronectin and beta-catenin levels increased in attached collagen-matrix cultures of disease cells, while control cultures showed only increases in fibronectin levels. Immunocytochemistry analysis also revealed extensive filamentous actin networks in disease cells, and enhanced attachment and spreading of disease cell in collagen matrices.
Conclusion: Three-dimensional collagen matrix cultures of primary disease cell lines are more contractile and express a more extensive filamentous actin network than patient-matched control cultures. The elevated levels of beta-catenin and Fn seen in collagen matrix cultures of disease fibroblasts can be regulated by changes in isometric tension.
Published in: BMC Musculoskeletal Disorders, 2003, 4:16. doi: 10.1186/1471-2474-4-16
https://ir.lib.uwo.ca/surgerypub/7
oai:ir.lib.uwo.ca:medpub-1011
2009-09-19T03:17:32Z
publication:biophysicspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:biophysics
publication:apmaths
publication:apmathspub
17509156
Erythropoietin Improves Skeletal Muscle Microcirculation and Tissue Bioenergetics in a Mouse Sepsis Model
Kao, Raymond
Xenocostas, Anargyros
Rui, Tao
Yu, Pei
Huang, Weixiong
Rose, James
Martin, Claudio M.
Article
2007-05-18T07:00:00Z
Animals
Disease Models
Animal
Energy Metabolism
Erythropoietin
Mice
Mice
Inbred C57BL
Microcirculation
Muscle
Skeletal
Sepsis
Treatment Outcome
Critical Care
Critical Care
11
R58
Medical Sciences
Musculoskeletal, Neural, and Ocular Physiology
Introduction: The relationship between oxygen delivery and consumption in sepsis is impaired, suggesting a microcirculatory perfusion defect. Recombinant human erythropoietin (rHuEPO) regulates erythropoiesis and also exerts complex actions promoting the maintenance of homeostasis of the organism under stress. The objective of this study was to test the hypothesis that rHuEPO could improve skeletal muscle capillary perfusion and tissue oxygenation in sepsis.
Methods: Septic mice in three experiments received rHu-EPO 400 U/kg subcutaneously 18 hours after cecal ligation and perforation (CLP). The first experiment measured the acute effects of rHuEPO on hemodynamics, blood counts, and arterial lactate level. The next two sets of experiments used intravital microscopy to observe capillary perfusion and nicotinamide adenine dinucleotide (NADH) fluorescence post-CLP after treatment with rHuEPO every 10 minutes for 40 minutes and at 6 hours. Perfused capillary density during a three-minute observation period and NADH fluorescence were measured.
Results: rHuEPO did not have any effects on blood pressure, lactate level, or blood cell numbers. CLP mice demonstrated a 22% decrease in perfused capillary density compared to the sham group (28.5 versus 36.6 capillaries per millimeter; p < 0.001). Treatment of CLP mice with rHuEPO resulted in an immediate and significant increase in perfused capillaries in the CLP group at all time points compared to baseline from 28.5 to 33.6 capillaries per millimeter at 40 minutes; p < 0.001. A significant increase in baseline NADH, suggesting tissue hypoxia, was noted in the CLP mice compared to the sham group (48.3 versus 43.9 fluorescence units [FU]; p = 0.03) and improved with rHuEPO from 48.3 to 44.4 FU at 40 minutes (p = 0.02). Six hours after treatment with rHuEPO, CLP mice demonstrated a higher mean perfused capillary density (39.4 versus 31.7 capillaries per millimeter; p < 0.001) and a lower mean NADH fluorescence as compared to CLP+normal saline mice (49.4 versus 52.7 FU; p = 0.03).
Conclusion: rHuEPO produced an immediate increase in capillary perfusion and decrease in NADH fluorescence in skeletal muscle. Thus, it appears that rHuEPO improves tissue bioenergetics, which is sustained for at least six hours in this murine sepsis model.
Published in: Critical Care, 2007, 11:R58. doi: 10.1186/cc5920
https://ir.lib.uwo.ca/medpub/7
oai:ir.lib.uwo.ca:surgerypub-1013
2009-10-08T01:16:30Z
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:surgery
15541177
Enhanced Dupuytren's Disease Fibroblast Populated Collagen Lattice Contraction is Independent of Endogenous Active TGF-beta2
Tse, Raymond
Howard, Jeffrey
Wu, Yan
Gan, Bing Siang
Article
2004-11-12T08:00:00Z
Antibodies
Anti-Idiotypic
Cells
Cultured
Collagen
Dose-Response Relationship
Drug
Dupuytren's Contracture
Fibroblasts
Humans
Transforming Growth Factor beta
Transforming Growth Factor beta2
BMC Musculoskeletal Disorders
5
41
Medical Biochemistry
Musculoskeletal, Neural, and Ocular Physiology
Surgery
Background: Dupuytren's disease (DD) is a debilitating fibro-proliferative disorder of the hand characterized by the appearance of fibrotic lesions (nodules and cords) leading to flexion contractures of the fingers and loss of hand function. Although the molecular mechanism of DD is unknown, it has been suggested that transforming growth factor-beta2 (TGF-beta2) may play an important role in the underlying patho-physiology of the disease. The purpose of this study was to further explore this hypothesis by examining the effects of TGF-beta2 on primary cell cultures derived from patient-matched disease and normal palmar fascia tissue using a three-dimensional collagen contraction assay.
Methods: Fibroblast-populated collagen lattice (FPCL) contraction assays using primary cell cultures derived from diseased and control fascia of the same DD patients were studied in response to exogenous TGF-beta2 and neutralizing anti-TGF-beta2 antibodies.
Results: Contraction of the FPCLs occurred significantly faster and to a greater extent in disease cells compared to control cells. The addition of TGF-beta2 enhanced the rate and degree of collagen contraction in a dose-dependent fashion for both control and diseased cells. Neutralizing anti-TGF-beta2 antibodies abolished exogenous TGF-beta2 stimulated collagen contraction, but did not inhibit the enhanced basal collagen contraction activity of disease FPCL cultures.
Conclusions: Although exogenous TGF-beta2 stimulated both disease and control FPCL contraction, neutralizing anti-TGF-beta2 antibodies did not affect the elevated basal collagen contraction activity of disease FPCLs, suggesting that the differences in the collagen contraction activity of control and disease FPCL cultures are not due to differences in the levels of endogenous TGF-beta2 activity.
Published in: BMC Musculoskeletal Disorders, 2004, 5:41. doi: 10.1186/1471-2474-5-41
https://ir.lib.uwo.ca/surgerypub/15
oai:ir.lib.uwo.ca:physpharmpub-1019
2009-09-21T00:03:52Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16774692
Scar Wars: Is TGFβ the Phantom Menace in Scleroderma?
Leask, Andrew
Article
2006-06-09T07:00:00Z
Cicatrix
Cytokines
Drug Synergism
Fibrosis
Humans
Scleroderma
Systemic
Smad Proteins
Transforming Growth Factor beta
Arthritis Research & Therapy
Arthritis Research & Therapy
8
213
Medical Physiology
Oral Biology and Oral Pathology
The autoimmune disease scleroderma (systemic sclerosis (SSc)) is characterized by extensive tissue fibrosis, causing significant morbidity. There is no therapy for the fibrosis observed in SSc; indeed, the underlying cause of the scarring observed in this disease is unknown. Transforming growth factor-β (TGFβ) has long been hypothesized to be a major contributor to pathological fibrotic diseases, including SSc. Recently, the signaling pathways through which TGFβ activates a fibrotic program have been elucidated and, as a consequence, several possible points for anti-fibrotic drug intervention in SSc have emerged.
Published in: Arthritis Research & Therapy, 2006, 8:213. doi: 10.1186/ar1976
https://ir.lib.uwo.ca/physpharmpub/20
oai:ir.lib.uwo.ca:patholpub-1004
2009-10-12T02:47:14Z
publication:patholpub
publication:physpharmpub
publication:pmid
publication:cns
publication:faculties
publication:cnspub
publication:pathol
publication:physpharm
15285794
Antioxidant Protection from HIV-1 gp120-induced Neuroglial Toxicity
Walsh, Kimberley A.
Megyesi, Joseph F.
Wilson, John X.
Crukley, Jeff
Laubach, Victor E.
Hammond, Robert R.
Article
2004-05-27T07:00:00Z
glycoprotein 120
antioxidant
HIV
neuroglial toxicity
Journal of Neuroinflammation
Journal of Neuroinflammation
1
8
Medical Pathology
Pathology
Background: The pathogenesis of HIV-1 glycoprotein 120 (gp120) associated neuroglial toxicity remains unresolved, but oxidative injury has been widely implicated as a contributing factor. In previous studies, exposure of primary human central nervous system tissue cultures to gp120 led to a simplification of neuronal dendritic elements as well as astrocytic hypertrophy and hyperplasia; neuropathological features of HIV-1-associated dementia. Gp120 and proinflammatory cytokines upregulate inducible nitric oxide synthase (iNOS), an important source of nitric oxide (NO) and nitrosative stress. Because ascorbate scavenges reactive nitrogen and oxygen species, we studied the effect of ascorbate supplementation on iNOS expression as well as the neuronal and glial structural changes associated with gp120 exposure.
Methods: Human CNS cultures were derived from 16-18 week gestation post-mortem fetal brain. Cultures were incubated with 400 microM ascorbate-2-O-phosphate (Asc-p) or vehicle for 18 hours then exposed to 1 nM gp120 for 24 hours. The expression of iNOS and neuronal (MAP2) and astrocytic (GFAP) structural proteins was examined by immunohistochemistry and immunofluorescence using confocal scanning laser microscopy (CSLM).
Results: Following gp120 exposure iNOS was markedly upregulated from undetectable levels at baseline. Double label CSLM studies revealed astrocytes to be the prime source of iNOS with rare neurons expressing iNOS. This upregulation was attenuated by the preincubation with Asc-p, which raised the intracellular concentration of ascorbate. Astrocytic hypertrophy and neuronal injury caused by gp120 were also prevented by preincubation with ascorbate.
Conclusions: Ascorbate supplementation prevents the deleterious upregulation of iNOS and associated neuronal and astrocytic protein expression and structural changes caused by gp120 in human brain cell cultures.
Published in: Journal of Neuroinflammation, 2004, 1:8. doi: 10.1186/1742-2094-1-8
https://ir.lib.uwo.ca/patholpub/5
oai:ir.lib.uwo.ca:medpub-1017
2009-10-12T05:01:19Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
11056725
Variation in Red Cell Transfusion Practice in the Intensive Care Unit: A Multicentre Cohort Study
Hébert, Paul C.
Wells, George
Martin, Claudio
Tweeddale, Martin
Marshall, John
Blajchman, Morris
Pagliarello, Giuseppe
Sandham, Dean
Schweitzer, Irwin
Boisvert, Denis
Calder, Lisa
Article
1999-04-29T07:00:00Z
Red Cells
Transfusions
Haemoglobin
Intensive Care
Critical Care
Critical Care
3
2
57
63
Medicine and Health Sciences
Objectives: To determine the degree of interinstitutional transfusion practice variation and reasons why red cells are administered in critically ill patients.
Study Design: Multicentre cohort study combined with a cross-sectional survey of physicians requesting red cell transfusions for patients in the cohort.
Study Population: The cohort included 5298 consecutive patients admitted to six tertiary level intensive care units in addition to administering a survey to 223 physicians requesting red cell transfusions in these units.
Measurements: Haemoglobin concentrations were collected, along with the number and reasons for red cell transfusions plus demographic, diagnostic, disease severity (APACHE II score), intensive care unit (ICU) mortality and lengths of stay in the ICU.
Results: Twenty five per cent of the critically ill patients in the cohort study received red cell transfusions. The overall number of transfusions per patient-day in the ICU averaged 0.95 +/- 1.39 and ranged from 0.82 +/- 1.69 to 1.08 +/- 1.27 between institutions (P < 0.001). Independent predictors of transfusion thresholds (pre-transfusion haemoglobin concentrations) included patient age, admission APACHE II score and the institution (P < 0.0001). A very significant institution effect (P < 0.0001) persisted even after multivariate adjustments for age, APACHE II score and within four diagnostic categories (cardiovascular disease, respiratory failure, major surgery and trauma) (P < 0.0001). The evaluation of transfusion practice using the bedside survey documented that 35% (202 of 576) of pre-transfusion haemoglobin concentrations were in the range of 95-105 g/l and 80% of the orders were for two packed cell units. The most frequent reasons for administering red cells were acute bleeding (35%) and the augmentation of O2 delivery (25%).
Conclusions: There is significant institutional variation in critical care transfusion practice, many intensivists adhering to a 100g/l threshold, and opting to administer multiple units despite published guidelines to the contrary. There is a need for prospective studies to define optimal practice in the critically ill.
Published in: Critical Care, 1999, 3:57-63. doi: 10.1186/cc310
https://ir.lib.uwo.ca/medpub/11
oai:ir.lib.uwo.ca:biochempub-1029
2009-09-23T16:51:23Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:mbrainpub
publication:robarts
publication:biochem
publication:institutes
19339245
Identification of a Novel Zn2+-binding Domain in the Autosomal Recessive Juvenile Parkinson-related E3 Ligase Parkin
Hristova, Ventzislava A.
Beasley, Steven A.
Rylett, Jane
Shaw, Gary S.
Article
2009-05-29T07:00:00Z
Amino Acid Sequence
Animals
Conserved Sequence
Humans
Models
Biological
Molecular Sequence Data
Parkinsonian Disorders
Protein Folding
Protein Processing
Post-Translational
Protein Stability
Protein Structure
Tertiary
Rats
Recombinant Fusion Proteins
Sequence Alignment
Serine Endopeptidases
Trypsin
Ubiquitin-Protein Ligases
Ubiquitination
Zinc
Journal of Biological Chemistry
284
22
14978
14986
Biochemistry
Neurosciences
Structural Biology
Missense mutations in park2, encoding the parkin protein, account for approximately 50% of autosomal recessive juvenile Parkinson disease (ARJP) cases. Parkin belongs to the family of RBR (RING-between-RING) E3 ligases involved in the ubiquitin-mediated degradation and trafficking of proteins such as Pael-R and synphillin-1. The proposed architecture of parkin, based largely on sequence similarity studies, consists of N-terminal ubiquitin-like and C-terminal RBR domains. These domains are separated by a approximately 160-residue unique parkin sequence having no recognizable domain structure. We used limited proteolysis experiments on bacterially expressed and purified parkin to identify a new domain (RING0) within the unique parkin domain sequence. RING0 comprises two distinct, conserved cysteine-rich clusters between Cys(150)-Cys(169) and Cys(196)-His(215) consisting of CX(2)-(3)CX(11)CX(2)C and CX(4-6)CX(10-16)-CX(2)(H/C) motifs. The positions of the cysteine/histidine residues in this region bear similarity to parkin RING1 and RING2 domains, as well as other E3 ligase RING domains. However, in parkin a 26-residue linker region separates the motifs, which is not typical of other RING domain structures. Further, the RING0 domain includes all but one of the known ARJP mutation sites between the ubiquitin-like and RBR regions of parkin. Using electrospray ionization mass spectrometry and inductively coupled plasma-atomic emission spectrometry analysis, we determined that the RING0, RING1, IBR, and RING2 domains each bind two Zn(2+) ions, the first observation of an E3 ligase with the ability to bind eight metal ions. Removal of the zinc from parkin causes near complete unfolding of the protein, an observation that rationalizes cysteine-based ARJP mutations found throughout parkin, including RING0 (C212Y) that form cellular inclusions and/or are defective for ubiquitination likely because of poor zinc binding and misfolding. The identification of the RING0 domain in parkin provides a new overall domain structure for the protein that will be important in assessing the roles of ARJP mutations and designing experiments aimed at understanding the disease.
Published in: J. Biol. Chem. 2009, 284: 14978-14986. doi: 10.1074/jbc.M808700200
https://ir.lib.uwo.ca/biochempub/26
oai:ir.lib.uwo.ca:surgerypub-1015
2009-09-23T00:46:56Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:faculties
publication:physpharm
publication:biophysics
publication:surgery
Wnt Expression Is Not Correlated with β-catenin Dysregulation in Dupuytren's Disease
O'Gorman, David B.
Wu, Yan
Seney, Shannon
Zhu, Rebecca D.
Gan, Bing Siang
Article
2006-08-30T07:00:00Z
Wnt expression
?-catenin
Dupuytren's Disease
Journal of Negative Results in BioMedicine
5
13
Medical Biophysics
Medical Physiology
Surgery
Background: Dupuytren's contracture or disease (DD) is a fibro-proliferative disease of the hand that results in finger flexion contractures. Increased cellular β-catenin levels have been identified as characteristic of this disease. As Wnts are the most widely recognized upstream regulators of cellular β-catenin accumulation, we have examined Wnt gene expression in surgical specimens and in DD-derived primary cell cultures grown in two-dimensional monolayer culture or in three-dimensional FPCL collagen lattice cultures.
Results: The Wnt expression profile of patient-matched DD and unaffected control palmar fascia tissue was determined by a variety of complimentary methods; Affymetrix Microarray analysis, specific Wnt and degenerative primer-based Reverse Transcriptase (RT)-PCR, and Real Time PCR. Microarray analysis identified 13 Wnts associated with DD and control tissues. Degenerate Wnt RT-PCR analysis identified Wnts 10b and 11, and to a lesser extent 5a and 9a, as the major Wnt family members expressed in our patient samples. Competitive RT-PCR analysis identified significant differences between the levels of expression of Wnts 9a, 10b and 11 in tissue samples and in primary cell cultures grown as monolayer or in FPCL, where the mRNA levels in tissue > FPCL cultures > monolayer cultures. Real Time PCR data confirmed the down-regulation of Wnt 11 mRNA in DD while Wnt 10b, the most frequently isolated Wnt in DD and control palmar fascia, displayed widely variable expression between the methods of analysis.
Conclusion: These data indicate that changes in Wnt expression per se are unlikely to be the cause of the observed dysregulation of β-catenin expression in DD.
Published in: Journal of Negative Results in BioMedicine, 2006, 5:13. doi: 10.1186/1477-5751-5-13
https://ir.lib.uwo.ca/surgerypub/12
oai:ir.lib.uwo.ca:surgerypub-1016
2009-10-10T03:22:14Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:biochem
publication:surgery
19545383
Type-1 Collagen Differentially Alters Beta-catenin Accumulation in Primary Dupuytren's Disease Cord and Adjacent Palmar Fascia Cells
Vi, Linda
Njarlangattil, Anna
Wu, Yan
Gan, Bing Siang
O'Gorman, David B.
Article
2009-06-19T07:00:00Z
Actins
Case-Control Studies
Cells
Cultured
Collagen Type I
Dupuytren's Contracture
Fascia
Humans
Recombinant Proteins
Time Factors
Transforming Growth Factor beta1
beta Catenin
BMC Musculoskeletal Disorders
10
72
Medical Biochemistry
Medical Biophysics
Medical Physiology
Surgery
Background: Dupuytren's Disease (DD) is a debilitating contractile fibrosis of the palmar fascia characterised by excess collagen deposition, contractile myofibroblast development, increased transforming growth factor-beta levels and beta-catenin accumulation. The aim of this study was to determine if a collagen-enriched environment, similar to in vivo conditions, altered beta-catenin accumulation by primary DD cells in the presence or absence of transforming growth factor-beta.
Methods: Primary DD and patient matched, phenotypically normal palmar fascia (PF) cells were cultured in the presence or absence of type-1 collagen and transforming growth factor-beta1. beta-catenin and alpha-smooth muscle actin levels were assessed by western immunoblotting and immunofluorescence microscopy.
Results: DD cells display a rapid depletion of cellular beta-catenin not evident in patient-matched PF cells. This effect was not evident in either cell type when cultured in the absence of type-1 collagen. Exogenous addition of transforming growth factor-beta1 to DD cells in collagen culture negates the loss of beta-catenin accumulation. Transforming growth factor-beta1-induced alpha-smooth muscle actin, a marker of myofibroblast differentiation, is attenuated by the inclusion of type-1 collagen in cultures of DD and PF cells.
Conclusion: Our findings implicate type-1 collagen as a previously unrecognized regulator of beta-catenin accumulation and a modifier of TGF-beta1 signaling specifically in primary DD cells. These data have implications for current treatment modalities as well as the design of in vitro models for research into the molecular mechanisms of DD.
Published in: BMC Musculoskeletal Disorders, 2009, 10:72. doi: 10.1186/1471-2474-10-72
https://ir.lib.uwo.ca/surgerypub/16
oai:ir.lib.uwo.ca:physpharmpub-1020
2010-05-20T00:07:51Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16469114
The Induction of CCN2 by TGFbeta1 Involves Ets-1
Van Beek, Jonathan P.
Kennedy, Laura
Rockel, Jason S.
Bernier, Suzanne M.
Leask, Andrew
Article
2006-01-16T08:00:00Z
Animals
Base Sequence
Connective Tissue Growth Factor
Drug Synergism
Gene Expression Regulation
Immediate-Early Proteins
Intercellular Signaling Peptides and Proteins
Mice
NIH 3T3 Cells
Promoter Regions
Genetic
Proto-Oncogene Protein c-ets-1
Proto-Oncogene Protein c-fli-1
Smad3 Protein
Transfection
Transforming Growth Factor beta
Transforming Growth Factor beta1
Arthritis Research & Therapy
Arthritis Research & Therapy
8
R36
http://dx.doi.org/10.1186/ar1890
Medical Physiology
CCN2 is encoded by an immediate-early gene induced in mesenchymal cells during the formation of blood vessels, bone and connective tissue. It plays key roles in cell adhesion and migration, as well as matrix remodeling. CCN2 is overexpressed in fibrosis, arthritis and cancer; thus, an understanding of how to control CCN2 expression is likely to have importance in developing therapies to combat these pathologies. Previously, we found that the promoter sequence GAGGAATG is important for Ccn2 gene regulation in NIH 3T3 fibroblasts. In this report, we show that this sequence mediates activation of the CCN2 promoter by the ETS family of transcription factors. Endogenous Ets-1 binds this element of the CCN2 promoter, and dominant negative Ets-1 and specific Ets-1 small interfering RNA block induction of CCN2 expression by TGFbeta. In the absence of added TGFbeta1, Ets-1, but not the related fli-1, synergizes with Smad 3 to activate the CCN2 promoter. Whereas the ability of transfected Ets-1 to activate the CCN2 promoter is dependent on protein kinase C (PKC), Ets-1 in the presence of co-transfected Smad3 does not require PKC, suggesting that the presence of Smad3 bypasses the requirement of Ets-1 for PKC to activate target promoter activity. Our results are consistent with the notion that Smad3 and Ets-1 cooperate in the induction of the CCN2 promoter by TGFbeta1. Antagonizing Ets-1 might be of benefit in attenuating CCN2 expression in fibrosis, arthritis and cancer, and may be useful in modulating the outcome of these disorders.
https://ir.lib.uwo.ca/physpharmpub/21
oai:ir.lib.uwo.ca:immunologypub-1017
2009-10-14T01:42:55Z
publication:mnipub
publication:physpharmpub
publication:pmid
publication:immunologypub
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:mni
publication:robarts
publication:institutes
16860758
Bacterial Superantigens Bypass Lck-Dependent T Cell Receptor Signaling by Activating a Gα11-Dependent, PLC-β-Mediated Pathway
Bueno, Clara
Lemke, Caitlin D.
Criado, Gabriel
Baroja, Miren L.
Ferguson, Stephen S. G.
Rahman, A. K. M. Nur-Ur
Tsoukas, Constantine D.
McCormick, John K.
Madrenas, Joaquin
Article
2006-07-01T07:00:00Z
Antigens
Bacterial
Antigens
CD4
Calcium
Cells
Cultured
Enterotoxins
Enzyme Activation
Extracellular Signal-Regulated MAP Kinases
GTP-Binding Protein alpha Subunits
Gq-G11
Humans
Interleukin-2
Isoenzymes
Lymphocyte Activation
Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
Phospholipase C beta
Phosphoserine
Protein Kinase C
Receptors
Antigen
T-Cell
Signal Transduction
Superantigens
Type C Phospholipases
Immunity
Immunity
25
1
67
78
Immunology and Infectious Disease
Medical Physiology
The paradigm to explain antigen-dependent T cell receptor (TCR) signaling is based on the activation of the CD4 or CD8 coreceptor-associated kinase Lck. It is widely assumed that this paradigm is also applicable to signaling by bacterial superantigens. However, these bacterial toxins can activate human T cells lacking Lck, suggesting the existence of an additional pathway of TCR signaling. Here we showed that this alternative pathway operates in the absence of Lck-dependent tyrosine-phosphorylation events and was initiated by the TCR-dependent activation of raft-enriched heterotrimeric Galpha11 proteins. This event, in turn, activated a phospholipase C-beta and protein kinase C-mediated cascade that turned on the mitogen-activated protein kinases ERK-1 and ERK-2, triggered Ca(2+) influx, and translocated the transcription factors NF-AT and NF-kappaB to the nucleus, ultimately inducing the production of interleukin-2 in Lck-deficient T cells. The triggering of this alternative pathway by superantigens suggests that these toxins use a G protein-coupled receptor as a coreceptor on T cells.
Published in: Immunity, Volume 25, Issue 1, 67-78, 1 July 2006. doi: 10.1016/j.immuni.2006.04.012
https://ir.lib.uwo.ca/immunologypub/17
oai:ir.lib.uwo.ca:physpharmpub-1022
2009-10-27T01:06:23Z
publication:physpharmpub
publication:pmid
publication:cns
publication:faculties
publication:cnspub
publication:physpharm
19501086
Pilocarpine Model of Temporal Lobe Epilepsy Shows Enhanced Response to General Anesthetics
Long, Jennifer J. A.
Shen, Bixia
Luo, Tao
Stewart, Lee
McMurran, Thomas J. A.
Leung, L. Stan
Article
2009-09-01T07:00:00Z
Anesthetics
General
Animals
Brain
Consciousness Disorders
Convulsants
Disease Models
Animal
Electroencephalography
Entorhinal Cortex
Epilepsy
Temporal Lobe
GABA Agonists
Halothane
Kindling
Neurologic
Male
Muscimol
Nerve Degeneration
Olfactory Pathways
Pentobarbital
Pilocarpine
Propofol
Rats
Rats
Sprague-Dawley
Status Epilepticus
Experimental Neurology
Experimental Neurology
219
1
308
318
Life Sciences
Medical Physiology
Neuroscience and Neurobiology
Pharmacy and Pharmaceutical Sciences
Systems Neuroscience
Complex partial seizures, commonly arising from temporal lobe epilepsy (TLE), are associated with neuronal loss and post-seizure impairment of consciousness. We tested the hypothesis that TLE subjects, in between seizures, are associated with a decreased level of consciousness that is manifested by an enhanced response to a general anesthetic. Two animal models of TLE--amygdala kindling and pilocarpine-induced status epilepticus (Pilo-SE)--were tested. Pilo-SE rats, but not amygdala-kindled rats, showed a prolonged loss of pain and righting responses after 20 and 40 mg/kg i.p. pentobarbital, 2% halothane, and 5 and 10 mg/kg i.v. propofol as compared to control saline-treated rats. Since the major pathology of Pilo-SE rats was cell loss in the piriform cortex (PC) and the entorhinal cortex (EC), we studied the anesthetic response after inactivation of the EC or PC by locally infusing GABAA receptor agonist muscimol. Muscimol inactivation of the PC or EC, as compared to saline infusion in the same rats, prolonged the duration of loss of righting reflex, typically without changing the duration of loss of tail-pinch response, after 20 mg/kg i.p. pentobarbital, 2% halothane and 5 mg/kg i.v. propofol. Muscimol infusion, as compared to saline infusion, in the PC or EC also tended to decrease 30-100 Hz gamma EEG in the frontal cortex. In conclusion, a TLE model that resulted in neuronal loss, Pilo-SE, enhanced the response to a general anesthetic that could partly be attributed to a loss of neurons in the EC and PC.
Published in: Experimental Neurology, Volume 219, Issue 1, September 2009, Pages 308-318. doi: 10.1016/j.expneurol.2009.05.036
https://ir.lib.uwo.ca/physpharmpub/23
oai:ir.lib.uwo.ca:physpharmpub-1021
2009-10-27T00:51:54Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
19744527
Kindled Seizure in the Prefrontal Cortex Activated Behavioral Hyperactivity and Increase in Accumbens Gamma Oscillations through the Hippocampus
Ma, Jingyi
Leung, L. Stan
Article
2010-01-05T08:00:00Z
prefrontal cortex
hippocampus
nucleus accumbens
behavioral hyperactivity
gamma waves
seizures
kindling
prepulse inhibition
Behavioral Brain Research
Behavioral Brain Research
206
1
68
77
Behavioral Neurobiology
Medical Physiology
Neuroscience and Neurobiology
Pharmacy and Pharmaceutical Sciences
Systems Neuroscience
In previous studies, we reported that a single afterdischarge (AD) or repeated ADs (kindling) in the hippocampus resulted in schizophrenia-like behaviors such as hyperactivity and loss of sensorimotor gating. Given that medial prefrontal cortex (PFC) dysfunction is also found in models of schizophrenia, we hypothesized that a single AD in the PFC induces postictal hyperactivity, and PFC kindling results in loss in prepulse inhibition (PPI). An AD was induced by stimulating the PFC with a 5s stimulus train of 60Hz frequency and 600-800muA intensity. An initial AD evoked in the PFC was not accompanied by clear postictal behavioral change. After partial kindling (11+/-2 ADs) of the PFC, the PFC-AD propagated into the hippocampus and nucleus accumbens (NAC) and postictal hyperactivity lasted >5min. The postictal hyperactivity was accompanied by increased gamma EEG oscillations in both PFC and NAC. A single AD in hippocampal CA1 also induced >5min of postictal hyperactivity and increased gamma oscillations in the NAC and the PFC, with a transient increase in hippocampus-NAC gamma coherence occurring 2-3min after a hippocampal AD. Electrolytic lesion or inactivation of the dorsal hippocampus abolished the behavioral hyperactivity and the NAC/PFC gamma wave increase induced by a PFC-AD. Kindling of the PFC (21 ADs) but not of the lateral frontal cortex resulted in a deficit of PPI to the acoustic startle response tested 3 days after the last AD. In summary, gamma waves in the NAC were found to accompany postictal hyperactivity induced by an AD in the PFC. Postictal gamma and hyperactivity required an intact hippocampus, perhaps through the hippocampal-NAC pathway. PFC kindling, similar to hippocampal CA1 kindling, resulted in a prolonged deficit in PPI.
Published in: Behavioural Brain Research, Volume 206, Issue 1, 5 January 2010, Pages 68-77. doi: 10.1016/j.bbr.2009.08.038
https://ir.lib.uwo.ca/physpharmpub/22
oai:ir.lib.uwo.ca:biochempub-1030
2009-11-10T17:38:45Z
publication:physpharmpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
19814781
Retinoic Acid Enhances Skeletal Muscle Progenitor Formation and Bypasses Inhibition by Bone Morphogenetic Protein 4 but not Dominant Negative β-catenin
Kennedy, Karen A. M.
Porter, Tammy
Mehta, Virja
Ryan, Scott D.
Price, Feodor
Peshdary, Vian
Karamboulas, Christina
Savage, Josée
Drysdale, Thomas A.
Li, Shun-Cheng
Bennett, Steffany A. L.
Skerjanc, Ilona S.
Article
2009-10-08T07:00:00Z
retinoic acid
skeletal myogenesis
?-catenin
bone morphogenetic protein
BMC Biology
7
67
Biochemistry
Physiology
Background: Understanding stem cell differentiation is essential for the future design of cell therapies. While retinoic acid (RA) is the most potent small molecule enhancer of skeletal myogenesis in stem cells, the stage and mechanism of its function has not yet been elucidated. Further, the intersection of RA with other signalling pathways that stimulate or inhibit myogenesis (such as Wnt and BMP4, respectively) is unknown. Thus, the purpose of this study is to examine the molecular mechanisms by which RA enhances skeletal myogenesis and interacts with Wnt and BMP4 signalling during P19 or mouse embryonic stem (ES) cell differentiation.
Results: Treatment of P19 or mouse ES cells with low levels of RA led to an enhancement of skeletal myogenesis by upregulating the expression of the mesodermal marker, Wnt3a, the skeletal muscle progenitor factors Pax3 and Meox1, and the myogenic regulatory factors (MRFs) MyoD and myogenin. By chromatin immunoprecipitation, RA receptors (RARs) bound directly to regulatory regions in the Wnt3a, Pax3, and Meox1 genes and RA activated a β-catenin-responsive promoter in aggregated P19 cells. In the presence of a dominant negative β-catenin/engrailed repressor fusion protein, RA could not bypass the inhibition of skeletal myogenesis nor upregulate Meox1 or MyoD. Thus, RA functions both upstream and downstream of Wnt signalling. In contrast, it functions downstream of BMP4, as it abrogates BMP4 inhibition of myogenesis and Meox1, Pax3, and MyoD expression. Furthermore, RA downregulated BMP4 expression and upregulated the BMP4 inhibitor, Tob1. Finally, RA inhibited cardiomyogenesis but not in the presence of BMP4.
Conclusion: RA can enhance skeletal myogenesis in stem cells at the muscle specification/progenitor stage by activating RARs bound directly to mesoderm and skeletal muscle progenitor genes, activating β-catenin function and inhibiting bone morphogenetic protein (BMP) signalling. Thus, a signalling pathway can function at multiple levels to positively regulate a developmental program and can function by abrogating inhibitory pathways. Finally, since RA enhances skeletal muscle progenitor formation, it will be a valuable tool for designing future stem cell therapies.
Published in: BMC Biology, 2009, 7:67. doi: 10.1186/1741-7007-7-67
https://ir.lib.uwo.ca/biochempub/28
oai:ir.lib.uwo.ca:kinpub-1004
2012-02-11T23:57:13Z
publication:kin
publication:fammedpub
publication:fammed
publication:rwkex_researcharticles
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:rwkex
publication:kinpub
publication:physmed
publication:med
publication:physpharm
publication:healthstudies
publication:physmedpub
publication:healthstudiespub
19646259
The Use of Group Dynamics Strategies to Enhance Cohesion in a Lifestyle Intervention Program for Obese Children
Martin, Luc J.
Burke, Shauna M.
Shapiro, Sheree
Carron, Albert V.
Irwin, Jennifer D.
Petrella, Robert
Prapavessis, Harry
Shoemaker, Kevin
Article
2009-07-31T07:00:00Z
Group dynamics
Obesity
Children
Lifestyle intervention
BMC Public Health
BMC Public Health
9
277
http://dx.doi.org/10.1186/1471-2458-9-277
Kinesiology
Public Health
<p>Background: Most research pertaining to childhood obesity has assessed the effectiveness of preventative interventions, while relatively little has been done to advance knowledge in the treatment of obesity. Thus, a 4-week family- and group-based intervention utilizing group dynamics strategies designed to increase cohesion was implemented to influence the lifestyles and physical activity levels of obese children.</p>
<p>Methods/Design: This paper provides an overview of the rationale for and implementation of the intervention for obese children and their families. Objectives of the intervention included the modification of health behaviors and cohesion levels through the use of group dynamics strategies. To date, a total of 15 children (7 boys and 8 girls, mean age = 10.5) and their families have completed the intervention (during the month of August 2008). Physiological and psychological outcomes were assessed throughout the 4-week intervention and at 3-, 6-, and 12-month follow-up periods.</p>
<p>Discussion: It is believed that the information provided will help researchers and health professionals develop similar obesity treatment interventions through the use of evidence-based group dynamics strategies. There is also a need for continued research in this area, and it is our hope that the Children's Health and Activity Modification Program (C.H.A.M.P.) will provide a strong base from which others may build.</p>
https://ir.lib.uwo.ca/kinpub/5
oai:ir.lib.uwo.ca:physpharmpub-1023
2010-01-07T07:29:39Z
publication:mnipub
publication:physpharmpub
publication:paed
publication:pmid
publication:immunologypub
publication:faculties
publication:physpharm
publication:mni
publication:robarts
publication:institutes
publication:paedpub
11481253
Inhibition of Cytokine Production and Interference in IL-2 Receptor-mediated Jak-Stat Signaling by the Hydroxylamine Metabolite of Sulfamethoxazole
Hess, David A.
O'Leary, Erin F.
Lee, James T.
Almawi, Wassim Y.
Madrenas, Joaquin
Rieder, Michael J.
Article
2001-08-01T07:00:00Z
Cytokines
DNA-Binding Proteins
Humans
Interferon-gamma
Interleukin-1
Interleukin-4
Janus Kinase 1
Janus Kinase 3
Milk Proteins
Phosphorylation
Protein-Tyrosine Kinases
Receptors
Interleukin-2
STAT3 Transcription Factor
STAT5 Transcription Factor
Signal Transduction
Sulfamethoxazole
Trans-Activators
Tumor Necrosis Factor-alpha
FASEB Journal
FASEB Journal
15
10
1855
1857
10.1096/fj.00-0583fje
Medical Immunology
Medical Microbiology
Pediatrics
Pharmacy and Pharmaceutical Sciences
Sulfonamides, used for the treatment of opportunistic infections in immunocompromised patients, are associated with a high incidence of adverse drug events, including severe hypersensitivity reactions. Imbalances in the production and detoxification of reactive sulfonamide metabolites have been implicated in the pathogenesis of these life-threatening reactions. The hydroxylamine metabolite of sulfamethoxazole (SMX-HA) inhibits the proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMCs) in vitro without reducing Interleukin 2 (IL-2) expression. We investigated the effects of SMX-HA on accessory cytokine expression and IL-2 receptor (IL-2R) mediated signal transduction. SMX-HA did not reduce significantly mRNA production of proinflammatory [tumor necrosis factor a (TNF-a) and IL-1b], Th1-type (IFN-g), and Th2-type cytokines (IL-4 and IL-10). Sublethal concentrations of SMX-HA (25 mM) reduced significantly the production of TNF-a, IL-1b, and IL4 protein without inhibiting the production of IFN-g. This finding suggests that exposure to SMX-HA might direct a response towards a Th-1 vs. a Th-2 response. Immunoblot analysis of IL-2R-mediated Janus kinases and signal transduction activators of transcription (Jak-Stat) signal transduction revealed diminished phosphorylation of Jak1 and Jak3 and inhibited downstream phosphorylation of Stat3, Stat5a, and IL-2Rg in phytohemagglutinin/rIL-2 activated PBMCs treated with SMX-HA. SMX-HA did not inhibit Jak association with IL-2Rg or IL-2Rb. These data illustrated that sublethal concentrations of SMX-HA interfere with IL-2R-mediated signal transduction, resulting in altered cytokine production and inhibition of lymphocyte proliferation.
https://ir.lib.uwo.ca/physpharmpub/28
oai:ir.lib.uwo.ca:physpharmpub-1024
2010-01-07T07:37:27Z
publication:mnipub
publication:physpharmpub
publication:paed
publication:pmid
publication:immunologypub
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:mni
publication:robarts
publication:institutes
publication:paedpub
10506572
Cytotoxicity of Sulfonamide Reactive Metabolites: Apoptosis and Selective Toxicity of CD8(+) Cells by the Hydroxylamine of Sulfamethoxazole
Hess, David A.
Sisson, Margaret E.
Suria, Hamza
Wijsman, John
Puvanesasingham, Ram
Madrenas, Joaquín
Rieder, Michael J.
Article
1999-10-01T07:00:00Z
Apoptosis
CD8-Positive T-Lymphocytes
DNA Fragmentation
Dose-Response Relationship
Drug
Humans
Immunomagnetic Separation
Phosphatidylserines
Sulfamethoxazole
Sulfonamides
T-Lymphocyte Subsets
FASEB Journal
FASEB Journal
13
13
1688
1698
Medical Immunology
Medical Microbiology
Pediatrics
Pharmacy and Pharmaceutical Sciences
Treatment with sulfonamide antibiotics in HIV-infected patients is associated with a high incidence (> 40%) of adverse drug events, including severe hypersensitivity reactions. Sulfonamide reactive metabolites have been implicated in the pathogenesis of these adverse reactions. Sulfamethoxazole hydroxylamine (SMX-HA) induces lymphocyte toxicity and suppression of proliferation in vitro; the mechanism(s) of these immunomodulatory effects remain unknown. We investigated the cytotoxicity of SMX-HA via apoptosis on human peripheral blood mononuclear cells and purified cell subpopulations in vitro. CD19(+), CD4(+), and CD8(+) cells were isolated from human peripheral blood by positive selection of cell surface molecules by magnetic bead separation. SMX-HA induced significant CD8(+) cell death (67 +/- 7%) at 100 microM SMX-HA, with only minimal CD4(+) cell death (8 +/- 4%). No significant subpopulation toxicity was shown when incubated with parent drug (SMX). Flow cytometry measuring phosphatidylserine externalization 24 h after treatment with 100 microM and 400 microM SMX-HA revealed 14.1 +/- 0.7% and 25. 6 +/- 4.2% annexin-positive cells, respectively, compared to 3.7 +/- 1.2% in control PBMCs treated with 400 microM SMX. Internucleosomal DNA fragmentation was observed in quiescent and stimulated PBMCs 48 h after incubation with SMX-HA. Our data show that CD8(+) cells are highly susceptible to the toxic effects of SMX-HA through enhanced cell death by apoptosis.
https://ir.lib.uwo.ca/physpharmpub/29
oai:ir.lib.uwo.ca:immunologypub-1049
2009-12-03T06:42:14Z
publication:mnipub
publication:physpharmpub
publication:pmid
publication:immunologypub
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:mni
publication:robarts
publication:institutes
10602045
Identification of a Novel Mechanism for Endotoxin-mediated Down-modulation of CC Chemokine Receptor Expression
Xu, Luoling
Khandaker, Masud H.
Barlic, Jana
Ran, Longsi
Borja, Miren L.
Madrenas, Joaquín
Rahimpour, Rahbar
Chen, Kong
Mitchell, Gordon
Tan, Christopher M.
DeVries, Mark
Feldman, Ross D.
Kelvin, David J.
Article
2000-01-01T08:00:00Z
Chemokine CCL2
Down-Regulation
Genistein
Humans
Lipopolysaccharides
Monocytes
Receptors
CCR2
Receptors
Chemokine
Receptors
Cytokine
Serine Endopeptidases
Serine Proteinase Inhibitors
Tosyllysine Chloromethyl Ketone
European Journal of Immunology
European Journal of Immunology
30
1
227
235
10.1002/1521-4141(200001)30:1<227::AID-IMMU227>3.0.CO;2-X
Immunology and Infectious Disease
In the present study, we explored the molecular mechanisms by which bacterial endotoxin (LPS) mediates the down-regulation of CCR2 receptors on human monocytes. We found that LPS induced a marked reduction in CCR2 cell surface protein levels which was blocked by pretreatment with the tyrosine kinase inhibitors genistein and herbimycin A. The effector mechanism underlying LPS-induced CCR2 down-modulation appears to involve the enzymatic activity of proteinases since Western blot analysis of LPS-stimulated monocytes revealed the degradation of a 38-kDa species corresponding to the CCR2B monomer. In RBL cells expressing the CCR2B-green fluorescent protein (GFP) fusion chemokine receptor, LPS stimulated the internalization and degradation of CCR2. The serine proteinase inhibitor N-alpha-p-tosyl-L-lysine chloromethyl ketone blocked LPS-induced down-modulation of CCR2 in monocytes and CCR2B-GFP in RBL cells. This work describes a previously uncharacterized mechanism for CC chemokine receptor down-modulation that is dependent upon tyrosine kinase activation and serine proteinase-mediated receptor degradation and may provide further insight into the mechanisms of leukocyte regulation during immunological and inflammatory responses.
https://ir.lib.uwo.ca/immunologypub/46
oai:ir.lib.uwo.ca:physpharmpub-1025
2010-01-07T07:42:37Z
publication:mnipub
publication:physpharmpub
publication:pmid
publication:immunologypub
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:mni
publication:robarts
publication:institutes
10359100
CD45 Modulation of CXCR1 and CXCR2 in Human Polymorphonuclear Leukocytes
Mitchell, Gordon B.
Khandaker, Masud H.
Rahimpour, Rahbar
Xu, Luoling
Lazarovits, Andrew I.
Pickering, J. Geoffrey
Suria, Hamza
Madrenas, Joaquín
Pomerantz, David K.
Feldman, Ross D.
Kelvin, David J.
Article
1999-05-01T07:00:00Z
Antibodies
Monoclonal
Antigens
CD
Antigens
CD45
Benzoquinones
Cells
Cultured
Chemokine CCL2
Chemokine CCL4
Down-Regulation
Genistein
Humans
Interleukin-8
Lactams
Macrocyclic
Macrophage Inflammatory Proteins
Neutrophils
Phosphorylation
Protein-Tyrosine Kinases
Quinones
Receptors
Chemokine
Receptors
Interleukin
Receptors
Interleukin-8A
Receptors
Interleukin-8B
Tyrosine
European Journal of Immunology
European Journal of Immunology
29
5
1467
1476
10.1002/(SICI)1521-4141(199905)29:05<1467::AID-IMMU1467>3.0.CO
Medical Immunology
Medical Microbiology
Medical Physiology
All leukocytes express the cell surface glycoprotein CD45, which has intrinsic intracellular protein tyrosine phosphatase activity. CD45 is known to play a regulatory role in activation-induced signaling in lymphocytes; however, little is known of its role in non-lymphoid leukocytes. Therefore, we examined the potential effect of CD45 on chemokine-induced signaling in human neutrophils (polymorphonuclear cells, PMN). Treating isolated PMN for 2 h with an anti-CD45RB antibody (Bra11) down-modulated expression of the chemokine receptors CXCR1 and CXCR2 to 44 +/- 10% and 47 +/- 9% of their respective controls. The tyrosine kinase inhibitors genistein and herbimycin A significantly inhibited the Bra11-induced down-modulation of CXCR1 and CXCR2. Furthermore, Bra11-treated PMN were functionally inhibited in their capacity to exhibit IL-8-induced transient intracellular Ca2+ increases. Selected targeting of CXC receptors is indicated by the fact that N-formyl-Met-Leu-Phe (fMLP) receptor expression and function were not lost following Bra11 treatment. The effect of Bra11 on IL-8-mediated function and receptor expression was paralleled by decreased tyrosine phosphorylation of a 54- to 60-kDa protein. These findings indicate that CD45 can act to modulate PMN responses to chemokines; thus agents regulating CD45 can potentially modulate leukocyte traffic and may represent a novel therapeutic approach towards the treatment of inflammatory diseases.
https://ir.lib.uwo.ca/physpharmpub/30
oai:ir.lib.uwo.ca:immunologypub-1053
2009-12-12T02:00:34Z
publication:mnipub
publication:physpharmpub
publication:pmid
publication:immunologypub
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:mni
publication:robarts
publication:institutes
10090924
Metalloproteinases Are Involved in Lipopolysaccharide- and Tumor Necrosis Factor-alpha-mediated Regulation of CXCR1 and CXCR2 Chemokine Receptor Expression
Khandaker, Masud H.
Mitchell, Gordon
Xu, Luoling
Andrews, Joseph D.
Singh, Rajkumari
Leung, Harry
Madrenas, Joaquín
Ferguson, Stephen S. G.
Feldman, Ross D.
Kelvin, David J.
Article
1999-04-01T08:00:00Z
Antigens
CD
Apoptosis
Calcium Signaling
Chemotaxis
Leukocyte
Dexamethasone
Down-Regulation
Edetic Acid
Endocytosis
GTP-Binding Proteins
Humans
Interleukin-8
Leucine
Leukocytes
Lipopolysaccharides
Metalloendopeptidases
Microscopy
Confocal
Phenanthrolines
Protease Inhibitors
Receptors
Chemokine
Receptors
Interleukin
Receptors
Interleukin-8A
Receptors
Interleukin-8B
Tumor Necrosis Factor-alpha
Blood
Blood
93
7
2173
2185
Immunology and Infectious Disease
The neutrophil-specific G-protein-coupled chemokine receptors, CXCR1 and CXCR2, bind with high affinity to the potent chemoattractant interleukin-8 (IL-8). The mechanisms of IL-8 receptor regulation are not well defined, although previous studies have suggested a process of ligand-promoted internalization as a putative regulatory pathway. Herein, we provide evidence for two distinct processes of CXCR1 and CXCR2 regulation. Confocal microscopy data showed a redistribution of CXCR1 expression from the cell surface of neutrophils to internal compartments after stimulation with IL-8, whereas stimulation with bacterial lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) did not induce CXCR1 internalization but instead mediated a significant loss of membrane-proximal CXCR1 staining intensity. To investigate whether proteolytic cleavage was the mechanism responsible for LPS- and TNF-alpha-induced downmodulation of IL-8 receptors, we tested a panel of proteinase inhibitors. The downmodulation of CXCR1 and CXCR2 by LPS and TNF-alpha was most dramatically inhibited by metalloproteinase inhibitors; 1, 10-phenanthroline and EDTA significantly attenuated LPS- and TNF-alpha-induced loss of CXCR1 and CXCR2 cell surface expression. Metalloproteinase inhibitors also blocked the release of CXCR1 cleavage fragments into the cell supernatants of LPS- and TNF-alpha-stimulated neutrophils. In addition, while treatment of neutrophils with LPS and TNF-alpha inhibited IL-8 receptor-mediated calcium mobilization and IL-8-directed neutrophil chemotaxis, both 1, 10-phenanthroline and EDTA blocked these inhibitory processes. In contrast, metalloproteinase inhibitors did not affect IL-8-mediated downmodulation of CXCR1 and CXCR2 cell surface expression or receptor signaling. Thus, these findings may provide further insight into the mechanisms of leukocyte regulation during immunologic and inflammatory responses.
https://ir.lib.uwo.ca/immunologypub/49
oai:ir.lib.uwo.ca:vascularpub-1016
2009-12-08T07:34:25Z
publication:vascularpub
publication:biophysicspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:biophysics
publication:biochempub
publication:robarts
publication:biochem
publication:institutes
19149606
NAD+, Sirtuins, and Cardiovascular Disease
Borradaile, Nica M.
Pickering, J. Geoffrey
Article
2009-01-01T08:00:00Z
Cardiovascular Diseases
Gene Expression Regulation
Enzymologic
Humans
Myocardium
NAD
Sirtuins
Current Pharmaceutical Design
15
1
110
117
Cardiology
Cardiovascular disease (CVD) is the most prevalent disease worldwide and there is intense interest in pharmaceutical approaches to reduce the burden of this chronic, aging-related condition. The sirtuin (SIRT) family of NAD(+)-dependent protein deacetylases and ADP-ribosyltransferases have emerged as exciting targets for CVD management that can impact the cardiovascular system both directly and indirectly, the latter by modulating whole body metabolism. SIRT1-4 regulate the activities of a variety of transcription factors, coregulators, and enzymes that improve metabolic control in adipose tissue, liver, skeletal muscle, and pancreas, particularly during obesity and aging. SIRT1 and 7 can control myocardial development and resist stress- and aging-associated myocardial dysfunction through the deacetylation of p53 and forkhead box O1 (FoxO1). By modulating the activity of endothelial nitric oxide synthase (eNOS), FoxO1, and p53, and the expression of angiotensin II type 1 receptor (AT1R), SIRT1 also promotes vasodilatory and regenerative functions in endothelial and smooth muscle cells of the vascular wall. Given the array of potentially beneficial effects of SIRT activation on cardiovascular health, interest in developing specific SIRT agonists is well-substantiated. Because SIRT activity depends on cellular NAD+ availability, enzymes involved in NAD+ biosynthesis, including nicotinamide phosphoribosyltransferase (Nampt), may also be valuable pharmaceutical targets for managing CVD. Herein we review the actions of the SIRT proteins on the cardiovascular system and consider the potential of modulating SIRT activity and NAD+ availability to control CVD.
https://ir.lib.uwo.ca/vascularpub/16
oai:ir.lib.uwo.ca:physpharmpub-1026
2009-12-21T00:44:30Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
19381935
Biochemical Analysis of Arginine Methylation in Transcription
Tini, Marc
Naeem, Hina
Torchia, Joseph
Book Chapter
2008-12-01T08:00:00Z
Animals
Antibody Specificity
Arginine
Baculoviridae
Biochemistry
Biological Assay
Biotinylation
Cell Extracts
Chromatin Immunoprecipitation
Histone Acetyltransferases
Humans
Mass Spectrometry
Methylation
Methyltransferases
Nuclear Receptor Coactivator 3
Peptides
Protein-Arginine N-Methyltransferases
Recombinant Fusion Proteins
Staining and Labeling
Trans-Activators
Transcription
Genetic
Methods in Molecular Biology Series
Methods in Molecular Biology Series
523
235
247
10.1007/978-1-59745-190-1_16
Medical Biochemistry
Medical Physiology
Protein arginine methylation has emerged as an important mechanism for regulating the functions of proteins involved in diverse aspects of gene regulation such as transcriptional activation and repression, mRNA processing and nuclear-cytoplasmic shuttling. This modification is catalyzed by the PRMT family of enzymes which utilize intracellular S-adenosyl methionine as a cofactor to dimethylate-specific arginines found within many target proteins.The establishment of in vitro biochemical assays as well as the development of modification-specific antibodies, and more recently mass spectrometry, have increased our understanding of the mechanism of catalysis of the PRMT family of enzymes. In the following discussion, we present some of the more commonly used in vivo and in vitro techniques which can be utilized to study the mechanism of arginine methylation and its role in transcription.
Published as a book chapter in: <em>Chromatin Protocols</em>. (2nd ed.). Srikumar P. Chellappan. (Ed.).
https://ir.lib.uwo.ca/physpharmpub/24
oai:ir.lib.uwo.ca:biochempub-1047
2011-09-06T02:14:05Z
publication:physpharmpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
19774083
Loss of ATRX in Chondrocytes Has Minimal Effects on Skeletal Development
Solomon, Lauren A.
Li, Jennifer R.
Bérubé, Nathalie G.
Beier, Frank
Article
2009-09-23T07:00:00Z
Genetics
Genomics
Developmental Biology
PLoS ONE
4
9
7106
7106
http://dx.doi.org/10.1371/journal.pone.0007106
Biochemistry
Medical Physiology
Pediatrics
<p>BACKGROUND: Mutations in the human ATRX gene cause developmental defects, including skeletal deformities and dwarfism. ATRX encodes a chromatin remodeling protein, however the role of ATRX in skeletal development is currently unknown. METHODOLOGY/PRINCIPAL FINDINGS: We induced Atrx deletion in mouse cartilage using the Cre-loxP system, with Cre expression driven by the collagen II (Col2a1) promoter. Growth rate, body size and weight, and long bone length did not differ in Atrx(Col2cre) mice compared to control littermates. Histological analyses of the growth plate did not reveal any differences between control and mutant mice. Expression patterns of Sox9, a transcription factor required for cartilage morphogenesis, and p57, a marker of cell cycle arrest and hypertrophic chondrocyte differentiation, was unaffected. However, loss of ATRX in cartilage led to a delay in the ossification of the hips in some mice. We also observed hindlimb polydactily in one out of 61 mutants. CONCLUSIONS/SIGNIFICANCE: These findings indicate that ATRX is not directly required for development or growth of cartilage in the mouse, suggesting that the short stature in ATR-X patients is caused by defects in cartilage-extrinsic mechanisms.</p>
https://ir.lib.uwo.ca/biochempub/45
oai:ir.lib.uwo.ca:biochempub-1049
2023-03-16T14:02:16Z
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:surgery
publication:biochem
19331810
Keloid Scarring, but Not Dupuytren's Contracture, Is Associated with Unexplained Carotid Atherosclerosis
Bhavsar, Sankalp
Nimigan, Andre
Hackam, Daniel G.
O'Gorman, David B.
Gan, Bing Siang
Spence, J. David
Article
2009-01-01T08:00:00Z
Aged
Carotid Artery Diseases
Dupuytren Contracture
Female
Humans
Keloid
Male
Middle Aged
Multivariate Analysis
Regression Analysis
Risk Factors
Clinical & Investigative Medicine
32
2
95
102
Biochemistry
Surgery
<p>BACKGROUND: Atherosclerosis, a response to injury, may be thought of as scarring in the artery wall. TGF-beta and associated signaling molecules have been implicated in the pathophysiology of keloid scarring, Dupuytren's Contracture and atherosclerotic plaques in independent studies. PURPOSE: To test the hypothesis that excess cutaneous scarring and Dupuytren's contractures predispose independently to carotid atherosclerosis . METHODS: Among 1,747 patients with plaque measurements and complete data for multivariable regression analysis, 57 Caucasian patients had Dupuytren's contractures and 12 had keloid scars. Carotid total plaque area (TPA) was measured by 2-Dimensional ultrasound. RESULTS: In linear multivariable regression analysis with coronary risk factors, keloid scars were associated with TPA (P= 0.018), but Dupuytren's contractures were not. Patients with keloid scarring were younger (P < 0.0001), and more likely to be diabetic (P < 0.0001) CONCLUSIONS: Keloid scarring is a clinical clue to excess atherosclerosis not explained by traditional risk factors. Such patients may benefit from therapy directed at targets related to signalling molecules common to both the process of keloid scarring and atherosclerosis. These findings suggest previously unexplored possibilities for the prevention and treatment of atherosclerosis. The differences between Dupuytren's and keloid scars that may identify such targets are discussed.</p>
https://ir.lib.uwo.ca/biochempub/47
oai:ir.lib.uwo.ca:physpharmpub-1027
2009-12-23T21:07:48Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:biochem
publication:surgery
19331809
An Alternative Kinase Activity Assay for Primary Cultures Derived from Clinical Isolates
McLean, Kristopher
Wu, Yan
Gan, Bing Siang
O'Gorman, David B.
Article
2009-01-01T08:00:00Z
Biological Assay
Biotinylation
Cells
Cultured
Humans
Peptides
Phosphorylation
Proto-Oncogene Proteins c-akt
Reproducibility of Results
Spectrometry
Mass
Matrix-Assisted Laser Desorption-Ionization
Clinical & Investigative Medicine
Clinical & Investigative Medicine
32
2
84
94
Medical Biochemistry
Medical Biophysics
Medical Physiology
Surgery
PURPOSE: The measurement of protein kinase activity is central to understanding the signaling pathways that regulate cellular proliferation and apoptosis in virtually all disease processes. These measurements typically involve either indirect, time consuming assessment methods that require large amounts of sample, such as western immunoblotting, or the use of high maintenance, specialized equipment not typically available to a small clinical research facility. The purpose of this project was to determine if a benchtop Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) unit could be used to detect and directly assess kinase activity of the serine/threonine kinase Akt.
METHOD: Biotinylated substrate peptides, predicted to be recognized and phosphorylated by Akt to varying extents, were incubated in crude lysates of primary cells derived directly from clinical isolates. Streptavidin-coated chips were then used to isolate the substrate peptides from the lysates after incubation. Finally SELDI-TOF-MS was used to detect the peptide substrates and identify any changes in mass resulting from phosphorylation.
RESULTS: The biotinylated peptide substrates were readily detected and a simple, rapid procedure that allows direct measurement of Akt activity in less than 1 microg of cell lysate in a 2microL volume was developed. Further, a linear correlation between native to phospho-peptide ratios and SELDI-TOF-MS output demonstrated that this approach is semi-quantitative.
CONCLUSION: This assay avoids many of the pitfalls associated with the currently available kinase protocols as well as labour-intensive mass-spectrometry analysis by specialist laboratories. We propose that this approach may be a viable alternative for clinical research laboratories aiming to measure the activity of kinases in clinical isolates.
https://ir.lib.uwo.ca/physpharmpub/25
oai:ir.lib.uwo.ca:obsgynpub-1003
2009-12-28T00:12:29Z
publication:anatomy
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:paed
publication:pmid
publication:faculties
publication:anatomypub
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
19369450
Gonadotropin-releasing Hormone-regulated Chemokine Expression in Human Placentation
Cavanagh, P. Craig
Dunk, Caroline
Pampillo, Macarena
Szereszewski, Jacob M.
Taylor, Jay E.
Kahiri, Caroline
Han, Victor
Lye, Stephen
Bhattacharya, Moshmi
Babwah, Andy V.
Article
2009-07-01T07:00:00Z
Angiogenic Proteins
Buserelin
Cell Line
Transformed
Chemokine CXCL2
Chemokine CXCL6
Chemokines
Chemokines
CXC
Chemotaxis
Leukocyte
Culture Media
Conditioned
Female
Fluorescent Antibody Technique
Gene Expression Profiling
Gonadotropin-Releasing Hormone
Hormone Antagonists
Humans
Interleukin-8
Jurkat Cells
Killer Cells
Natural
Neovascularization
Physiologic
Oligonucleotide Array Sequence Analysis
Oligopeptides
Placentation
Pregnancy
Receptors
Interleukin-8A
Receptors
Interleukin-8B
Receptors
LHRH
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
T-Lymphocytes
Time Factors
Trophoblasts
American Journal of Physiology-Cell Physiology
American Journal of Physiology-Cell Physiology
297
1
C17
C27
10.1152/ajpcell.00013.2009
Anatomy
Medical Physiology
Obstetrics and Gynecology
Pediatrics
Placental expression of gonadotropin-releasing hormone (GnRH)-I and II, as well as their cognate receptor, coincides with a period of extensive remodeling of the maternal-fetal interface, near the end of the first trimester of pregnancy. To further define the role of GnRH in human placentation, we performed a microarray screen of HTR-8/SVneo trophoblasts to identify GnRH-regulated genes and their roles in placentation. This screen revealed that GnRH regulates the expression of four angiogenic chemokines: CXCL2, CXCL3, CXCL6, and CXCL8. The microarray data were subsequently confirmed by an extensive Q-PCR time-course analysis. CXCL8, a representative chemokine, was selected for further analysis and shown to be strongly expressed by trophoblasts at the maternal-fetal interface of the human placenta, as well as to accumulate in a GnRH-dependent manner in trophoblast-conditioned media in culture. Trophoblasts were subsequently shown to recruit lymphocytes (Jurkat T cells and primary peripheral blood T and uterine natural killer cells) in chemotaxis assays and this was shown to be GnRH dependent. Furthermore, this recruitment was shown to occur via the release of CXCR1/CXCR2 interacting chemokines, such as the CXCLs investigated in this study. This novel regulation of chemokines by GnRH signaling demonstrates the role of GnRH in regulating the recruitment of lymphocytes to the decidua and the possibility of a direct effect on spiral artery remodeling via the release of proangiogenic chemokines and secondary effects via release of angiogenic factors by recruited lymphocytes.
https://ir.lib.uwo.ca/obsgynpub/4
oai:ir.lib.uwo.ca:physpharmpub-1028
2009-12-28T00:51:51Z
publication:physpharmpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
19439446
Integrin-linked Kinase Interactions with ELMO2 Modulate Cell Polarity
Ho, Ernest
Irvine, Tames
Vilk, Gregory J. A.
Lajoie, Gilles
Ravichandran, Kodi S.
D'Souza, Sudhir J. A.
Dagnino, Lina
Article
2009-07-01T07:00:00Z
Adaptor Proteins
Signal Transducing
Animals
Animals
Newborn
Ankyrin Repeat
Binding Sites
Cell Movement
Cell Polarity
Cells
Cultured
Cytoskeletal Proteins
GTP Phosphohydrolases
Green Fluorescent Proteins
Humans
Immunoblotting
Immunoprecipitation
Infant
Newborn
Keratinocytes
Male
Mice
Microscopy
Confocal
Protein Binding
Protein-Serine-Threonine Kinases
Proteome
Proteomics
Molecular Biology of the Cell
Molecular Biology of the Cell
20
13
3033
3043
10.1091/mbc.E09-01-0050
Medical Biochemistry
Medical Physiology
Pediatrics
Cell polarization is a key prerequisite for directed migration during development, tissue regeneration, and metastasis. Integrin-linked kinase (ILK) is a scaffold protein essential for cell polarization, but very little is known about the precise mechanisms whereby ILK modulates polarization in normal epithelia. Elucidating these mechanisms is essential to understand tissue morphogenesis, transformation, and repair. Here we identify a novel ILK protein complex that includes Engulfment and Cell Motility 2 (ELMO2). We also demonstrate the presence of RhoG in ILK-ELMO2 complexes, and the localization of this multiprotein species specifically to the leading lamellipodia of polarized cells. Significantly, the ability of RhoG to bind ELMO is crucial for ILK induction of cell polarization, and the joint expression of ILK and ELMO2 synergistically promotes the induction of front-rear polarity and haptotactic migration. This places RhoG-ELMO2-ILK complexes in a key position for the development of cell polarity and forward movement. Although ILK is a component of many diverse multiprotein species that may contribute to cell polarization, expression of dominant-negative ELMO2 mutants is sufficient to abolish the ability of ILK to promote cell polarization. Thus, its interaction with ELMO2 and RhoG is essential for the ability of ILK to induce front-rear cell polarity.
https://ir.lib.uwo.ca/physpharmpub/26
oai:ir.lib.uwo.ca:dentistrypub-1004
2009-12-28T23:07:18Z
publication:physpharmpub
publication:dentistrypub
publication:chemengpub
publication:pmid
publication:faculties
publication:physpharm
publication:dentistry
publication:biochempub
publication:chemeng
publication:biochem
19531334
Tissue Engineering Scaffolds for the Regeneration of Craniofacial Bone
Chan, Wailan D.
Perinpanayagam, Hiran
Goldberg, Harvey A.
Hunter, Graeme K.
Dixon, S. Jeffrey
Santos, Gildo C.
Rizkalla, Amin S.
Article
2009-06-01T07:00:00Z
Biocompatible Materials
Biomimetic Materials
Bone Regeneration
Calcium Phosphates
Electrochemistry
Extracellular Matrix
Humans
Materials Testing
Methacrylates
Nanostructures
Osteopontin
Polyesters
Polymers
Porosity
Surface Properties
Tissue Engineering
Tissue Scaffolds
Journal of the Canadian Dental Association
Journal of the Canadian Dental Association
75
5
373
377
Chemical Engineering
Dentistry
Medical Biochemistry
Medical Physiology
Current strategies for skeletal regeneration involve the use of autogenous and allogenic bone grafts that may not always be available or safe to use. One alternative is to develop materials for use as scaffolds for the tissue engineering of bone. We created architecturally nanofibrous scaffolds using the electrospinning technique. These calcium phosphate- based materials are porous, have a large surface-area-to-volume ratio and can be used to deliver drugs, biologics or cells for tissue engineering applications. Bone-matrix proteins were also conjugated to the surface of a polymer network of polycaprolactone and poly(2-hydroxyethyl methacrylate) to create a material with enhanced cellular responses. This biomimetic strategy resulted in favourable cell-surface interactions that will likely enhance bone-matrix synthesis and regeneration. These collective advancements enable the development of innovative scaffolds for applications in tissue engineering and bone regeneration.
https://ir.lib.uwo.ca/dentistrypub/4
oai:ir.lib.uwo.ca:physpharmpub-1029
2009-12-29T23:27:25Z
publication:physpharmpub
publication:dentistrypub
publication:pmid
publication:faculties
publication:physpharm
publication:dentistry
publication:biochempub
publication:biochem
19531332
Skeletal Biology Research at the University of Western Ontario: Successful Synergy among Dental and Medical Scientists
Dixon, S. Jeffrey
Hunter, Graeme K.
Article
2009-06-01T07:00:00Z
Biomedical Research
Cooperative Behavior
Dental Research
Humans
Mouth Diseases
Musculoskeletal Diseases
Ontario
Schools
Dental
Schools
Medical
Universities
Journal of the Canadian Dental Association
Journal of the Canadian Dental Association
75
5
347
351
Dentistry
Medical Biochemistry
Medical Physiology
https://ir.lib.uwo.ca/physpharmpub/27
oai:ir.lib.uwo.ca:surgerypub-1022
2010-01-01T02:38:39Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:biochem
publication:surgery
19619531
Periostin Differentially Induces Proliferation, Contraction and Apoptosis of Primary Dupuytren's Disease and Adjacent Palmar Fascia Cells
Vi, Linda
Feng, Lucy
Zhu, Rebecca D.
Wu, Yan
Satish, Latha
Gan, Bing Siang
O'Gorman, David B.
Article
2009-12-10T08:00:00Z
Dupuytren's disease
palmar fascia cell
Experimental Cell Research
315
20
3574
3586
10.1016/j.yexcr.2009.07.015
Medical Biochemistry
Medical Biophysics
Medical Physiology
Surgery
Dupuytren's disease, (DD), is a fibroproliferative condition of the palmar fascia in the hand, typically resulting in permanent contracture of one or more fingers. This fibromatosis is similar to scarring and other fibroses in displaying excess collagen secretion and contractile myofibroblast differentiation. In this report we expand on previous data demonstrating that POSTN mRNA, which encodes the extra-cellular matrix protein periostin, is up-regulated in Dupuytren's disease cord tissue relative to phenotypically normal palmar fascia. We demonstrate that the protein product of POSTN, periostin, is abundant in Dupuytren's disease cord tissue while little or no periostin immunoreactivity is evident in patient-matched control tissues. The relevance of periostin up-regulation in DD was assessed in primary cultures of cells derived from diseased and phenotypically unaffected palmar fascia from the same patients. These cells were grown in type-1 collagen-enriched culture conditions with or without periostin addition to more closely replicate the in vivo environment. Periostin was found to differentially regulate the apoptosis, proliferation, alpha smooth muscle actin expression and stressed Fibroblast Populated Collagen Lattice contraction of these cell types. We hypothesize that periostin, secreted by disease cord myofibroblasts into the extra-cellular matrix, promotes the transition of resident fibroblasts in the palmar fascia toward a myofibroblast phenotype, thereby promoting disease progression.
https://ir.lib.uwo.ca/surgerypub/21
oai:ir.lib.uwo.ca:paedpub-1012
2010-10-04T18:42:45Z
publication:physpharmpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
19664632
Fibroblast Growth Factor 21 Reduces the Severity of Cerulein-Induced Pancreatitis in Mice
Johnson, Charis L.
Weston, Jacqueline Y.
Chadi, Sami A.
Fazio, Elena N.
Huff, Murray W.
Kharitonenkov, Alexei
Köester, Anja
Pin, Christopher L.
Article
2009-11-01T07:00:00Z
Animals
Caerulein
Cell Culture Techniques
Early Growth Response Protein 1
Fibroblast Growth Factors
Mice
Mice
Inbred C57BL
Pancreas
Exocrine
Pancreatitis
RNA
Messenger
Rats
Receptors
Fibroblast Growth Factor
Gastroenterology
Gastroenterology
137
5
1795
1804
http://dx.doi.org/10.1053/j.gastro.2009.07.064
Medical Biochemistry
Pediatrics
BACKGROUND & AIMS: Fibroblast growth factor 21 (FGF21) acts as a hormonal regulator during fasting and is involved in lipid metabolism. Fgf21 gene expression is regulated by peroxisome proliferator-activated receptor (PPAR)-dependent pathways, which are enhanced during pancreatitis. Therefore, the aim of this study was to investigate FGF21's role in pancreatic injury.
METHODS: Fgf21 expression was quantified during cerulein-induced pancreatitis (CIP) or following mechanical or thapsigargin-induced stress through Northern blot analysis, in situ hybridization, and quantitative reverse transcription polymerase chain reaction. FGF21 protein was quantified by Western blot analysis. Isolated acinar cells or AR42J acinar cells were treated with recombinant FGF21 protein, and extracellular regulated kinase 1/2 activation was examined. The severity of CIP was compared between wild-type mice and mice overexpressing FGF21 (FGF21Tg) or harboring a targeted deletion of Fgf21 (Fgf21(-/-)).
RESULTS: Acinar cell Fgf21 expression markedly increased during CIP and following injury in vitro. Purified FGF21 activated the extracellular regulated kinase 1/2 pathway in pancreatic acinar cells. The severity of CIP is inversely correlated to FGF21 expression because FGF21Tg mice exhibited decreased serum amylase and decreased pancreatic stellate cell activation, whereas Fgf21(-/-) mice had increased serum amylase and tissue damage. The expression of Fgf21 was also inversely correlated to expression of Early growth response 1, a proinflammatory and profibrotic transcription factor.
CONCLUSIONS: These studies suggest a novel function for Fgf21 as an immediate response gene protecting pancreatic acini from overt damage.
https://ir.lib.uwo.ca/paedpub/12
oai:ir.lib.uwo.ca:physpharmpub-1030
2010-01-10T02:43:38Z
publication:vascularpub
publication:biophysicspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:biophysics
publication:biochempub
publication:robarts
publication:biochem
publication:institutes
19846757
Polyploidy Impairs Human Aortic Endothelial Cell Function and Is Prevented by Nicotinamide Phosphoribosyltransferase
Borradaile, Nica M.
Pickering, J. Geoffrey
Article
2010-01-01T08:00:00Z
Polyploid endothelial cell
artery
American Journal of Physiology - Cell Physiology
American Journal of Physiology - Cell Physiology
298
1
66
74
10.1152/ajpcell.00357.2009
Medical Biochemistry
Medical Biophysics
Medical Physiology
Polyploid endothelial cells are found in aged and atherosclerotic arteries. However, whether increased chromosome content has an impact on endothelial cell function is unknown. We show here that human aortic endothelial cells become tetraploid as they approach replicative senescence. Furthermore, accumulation of tetraploid endothelial cells was accelerated during growth in high glucose. Interestingly, induction of polyploidy was completely prevented by modest overexpression of the NAD+ regenerating enzyme, nicotinamide phosphoribosyltransferase (Nampt). To determine the impact of polyploidy on endothelial cell function, independent of replicative senescence, we induced tetraploidy using the spindle poison, nocodazole. Global gene expression analyses of tetraploid endothelial cells revealed a dysfunctional phenotype characterized by a cell cycle arrest profile (decreased CCNE2/A2, RBL1, BUB1B; increased CDKN1A) and increased expression of genes involved in inflammation (IL32, TNFRSF21/10C, PTGS1) and extracellular matrix remodeling (COL5A1, FN1, MMP10/14). The protection from polyploidy conferred by Nampt was not associated with enhanced poly(ADP-ribose) polymerase-1 or sirtuin (SIRT) 2 activity, but with increased SIRT1 activity, which reduced cellular reactive oxygen species and the associated oxidative stress stimulus for the induction of polyploidy. We conclude that human aortic endothelial cells are prone to chromosome duplication that, in and of itself, can induce characteristics of endothelial dysfunction. Moreover, the emergence of polyploid endothelial cells during replicative aging and glucose overload can be prevented by optimizing the Nampt-SIRT1 axis.
https://ir.lib.uwo.ca/physpharmpub/31
oai:ir.lib.uwo.ca:medpub-1031
2010-01-13T01:51:35Z
publication:vascularpub
publication:fammedpub
publication:fammed
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
publication:epidem
publication:biochempub
publication:robarts
publication:biochem
publication:institutes
publication:epidempub
19417859
The 2009 Canadian Hypertension Education Program Recommendations for the Management of Hypertension: Part 2--Therapy
Khan, Nadia A.
Hemmelgarn, Brenda
Herman, Robert J.
Bell, Chaim M.
Mahon, Jeff L.
Leiter, Lawrence A.
Rabkin, Simon W.
Hill, Michael D.
Padwal, Raj
Touyz, Rhian M.
Larochelle, Pierre
Feldman, Ross D.
Schiffrin, Ernesto L.
Campbell, Norman R. C.
Moe, Gordon
Prasad, Ramesh
Arnold, Malcolm O.
Campbell, Tavis S.
Milot, Alain
Stone, James A.
Jones, Charlotte
Ogilvie, Richard I.
Hamet, Pavel
Fodor, George
Carruthers, George
Burns, Kevin D.
Ruzicka, Marcel
deChamplain, Jacques
Pylypchuk, George
Petrella, Robert
Boulanger, Jean-Martin
Trudeau, Luc
Hegele, Robert A.
Woo, Vincent
McFarlane, Phil
Vallée, Michel
Howlett, Jonathan
Bacon, Simon L.
Lindsay, Patrice
Gilbert, Richard E.
Lewanczuk, Richard Z.
Tobe, Sheldon
Canadian Hypertension Education Program
Article
2009-05-01T07:00:00Z
Adult
Aged
Antihypertensive Agents
Blood Pressure Determination
Canada
Case Management
Combined Modality Therapy
Diet
Sodium-Restricted
Female
Health Promotion
Humans
Hypertension
Life Style
Male
Middle Aged
Patient Education as Topic
Prognosis
Program Evaluation
Randomized Controlled Trials as Topic
Treatment Outcome
Canadian Journal of Cardiology
Canadian Journal of Cardiology
25
5
287
298
Cardiology
OBJECTIVE: To update the evidence-based recommendations for the prevention and management of hypertension in adults for 2009.
OPTIONS AND OUTCOMES: For lifestyle and pharmacological interventions, evidence from randomized controlled trials and systematic reviews of trials was preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. Progression of kidney dysfunction was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.
EVIDENCE: A Cochrane collaboration librarian conducted an independent MEDLINE search from 2007 to August 2008 to update the 2008 recommendations. To identify additional published studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.
RECOMMENDATIONS: For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium to less than 2300 mg (100 mmol)/day (and 1500 mg to 2300 mg [65 mmol to 100 mmol]/day in hypertensive patients); perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m(2) to 24.9 kg/m(2)) and waist circumference (smaller than 102 cm for men and smaller than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a diet that is reduced in saturated fat and cholesterol, and that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and consider stress management in selected individuals with hypertension. For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on by the patient's global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to lower than 140/90 mmHg in all patients, and to lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. Antihypertensive therapy should be considered in all adult patients regardless of age (caution should be exercised in elderly patients who are frail). For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin- converting enzyme (ACE) inhibitors (in patients who are not black), long-acting calcium channel blockers (CCBs), angiotensin receptor antagonists (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered as the initial treatment of hypertension if the systolic blood pressure is 20 mmHg above the target or if the diastolic blood pressure is 10 mmHg above the target. The combination of ACE inhibitors and ARBs should not be used. Other agents appropriate for first-line therapy for isolated systolic hypertension include long- acting dihydropyridine CCBs or ARBs. In patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with proteinuric nondiabetic chronic kidney disease, ACE inhibitors or ARBs (if intolerant to ACE inhibitors) are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.
VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.
https://ir.lib.uwo.ca/medpub/25
oai:ir.lib.uwo.ca:physpharmpub-1031
2010-02-22T03:42:05Z
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:surgery
19896280
The Potential Roles of Cell Migration and Extra-cellular Matrix Interactions in Dupuytren's Disease Progression and Recurrence
Vi, Linda
Gan, Bing Siang
O'Gorman, David B.
Article
2010-03-01T08:00:00Z
cell migration
extra-cellular matrix interactions
Dupuytren’s disease
Medical Hypotheses
Medical Hypotheses
74
3
510
512
http://dx.doi.org/10.1016/j.mehy.2009.10.009
Medical Biochemistry
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Dupuytren's disease is a pathological condition of the palmar fascia characterized by the formation of contractile disease cords that result in permanent finger contracture. This condition is believed to progress from a myofibroblast-rich nodule in the early clinical stages of the disease to a contractile disease cord spanning a portion of the fascia, leading to contracture of one or more digits. The mechanism(s) by which this disease progresses from a nodule to a collagenous disease cord are poorly understood. Here, we discuss two possible models of disease progression. Firstly, disease progression might be mediated by the proliferation and outward migration of disease cells from within the nodule to populate the adjacent palmar fascia, resulting in a disease cord containing contractile cells derived from the nodule itself. Alternatively, nodular cells may secrete disease-associated factors into the surrounding extra-cellular matrix, thereby altering its composition and triggering quiescent, phenotypically normal cells in the adjacent palmar fascia to take on a proliferative and contractile phenotype. Based on the available evidence and the current state of knowledge of myofibroblast biology, we hypothesize that extra-cellular matrix interactions resulting in conversion of adjacent palmar fascia cells to a disease phenotype is more likely than cell migration from the nodule. Understanding the mechanisms of Dupuytren's disease progression will assist in the development of effective therapeutic interventions to address the high clinical recurrence rate of this condition.
https://ir.lib.uwo.ca/physpharmpub/32
oai:ir.lib.uwo.ca:physpharmpub-1032
2010-03-09T01:51:48Z
publication:physpharmpub
publication:oncpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:onc
19966277
Opposing Regulatory Roles of Phosphorylation and Acetylation in DNA Mispair Processing by Thymine DNA Glycosylase
Mohan, Ryan D.
Litchfield, David W.
Torchia, Joseph
Tini, Marc
Article
2010-03-01T08:00:00Z
phosphorylation
acetylation
DNA mispair processing
thymine DNA glycosylase
Nucleic Acids Research
Nucleic Acids Research
38
4
1135
1148
http://dx.doi.org/10.1093/nar/gkp1097
Medical Biochemistry
Medical Physiology
Oncology
CpG dinucleotides are mutational hotspots associated with cancer and genetic diseases. Thymine DNA glycosylase (TDG) plays an integral role in CpG maintenance by excising mispaired thymine and uracil in a CpG context and also participates in transcriptional regulation via gene-specific CpG demethylation and functional interactions with the transcription machinery. Here, we report that protein kinase C alpha (PKCalpha) interacts with TDG and phosphorylates amino-terminal serine residues adjacent to lysines acetylated by CREB-binding protein (CBP) and p300 (CBP/p300). We establish that acetylation and phosphorylation are mutually exclusive, and their interplay dramatically alters the DNA mispair-processing functions of TDG. Remarkably, acetylation of the amino-terminal region abrogates high-affinity DNA binding and selectively prevents processing of G:T mispairs. In contrast, phosphorylation does not markedly alter DNA interactions, but may preserve G:T processing in vivo by preventing CBP-mediated acetylation. Mutational analysis suggests that the acetyl-acceptor lysines are not directly involved in contacting DNA, but may constitute a conformationally sensitive interface that modulates DNA interactions. These findings reveal opposing roles of CBP/p300 and PKCalpha in regulating the DNA repair functions of TDG and suggest that the interplay of these modifications in vivo may be critically important in the maintenance of CpG dinucleotides and epigenetic regulation.
https://ir.lib.uwo.ca/physpharmpub/33
oai:ir.lib.uwo.ca:mbrainpub-1004
2010-03-12T21:53:28Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:mbrainpub
publication:robarts
publication:institutes
20180987
Pyk2 uncouples metabotropic glutamate receptor G protein signaling but facilitates ERK1/2 activation.
Nicodemo, Alexander A.
Pampillo, Macarena
Ferreira, Lucimar T.
Dale, Lianne B.
Cregan, Tamara
Ribeiro, Fabiola M.
Ferguson, Stephen S. G.
Article
2010-01-21T08:00:00Z
ERK1/2 activation
Pyk2
Molecular Brain
Molecular Brain
3
1
4
http://dx.doi.org/10.1186/1756-6606-3-4
Medical Neurobiology
Molecular and Cellular Neuroscience
Neurology
Neurosciences
Group I metabotropic glutamate receptors (mGluRs) are coupled via Galphaq/11 to the activation of phospholipase Cbeta, which hydrolyzes membrane phospholipids to form inositol 1,4,5 trisphosphate and diacylglycerol. This results in the release of Ca2+ from intracellular stores and the activation of protein kinase C. The activation of Group I mGluRs also results in ERK1/2 phosphorylation. We show here, that the proline-rich tyrosine kinase 2 (Pyk2) interacts with both mGluR1 and mGluR5 and is precipitated with both receptors from rat brain. Pyk2 also interacts with GST-fusion proteins corresponding to the second intracellular loop and the distal carboxyl-terminal tail domains of mGluR1a. Pyk2 colocalizes with mGluR1a at the plasma membrane in human embryonic kidney (HEK293) cells and with endogenous mGluR5 in cortical neurons. Pyk2 overexpression in HEK293 results in attenuated basal and agonist-stimulated inositol phosphate formation in mGluR1 expressing cells and involves a mechanism whereby Pyk2 displaces Galphaq/11 from the receptor. The activation of endogenous mGluR1 in primary mouse cortical neuron stimulates ERK1/2 phosphorylation. Treatments that prevent Pyk2 phosphorylation in cortical neurons, and the overexpression of Pyk2 dominant-negative and catalytically inactive Pyk2 mutants in HEK293 cells, prevent ERK1/2 phosphorylation. The Pyk2 mediated activation of ERK1/2 phosphorylation is also Src-, calmodulin- and protein kinase C-dependent. Our data reveal that Pyk2 couples the activation mGluRs to the mitogen-activated protein kinase pathway even though it attenuates mGluR1-dependent G protein signaling.
https://ir.lib.uwo.ca/mbrainpub/5
oai:ir.lib.uwo.ca:obsgynpub-1005
2011-02-28T00:41:53Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:paed
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
publication:paedpub
20171025
IL-6 and TNFalpha across the Umbilical Circulation in Term Pregnancies: Relationship with Labour Events
Duncombe, Greg
Veldhuizen, Ruud A. W.
Gratton, Robert J.
Han, Victor K. M.
Richardson, Bryan S.
Article
2010-02-01T08:00:00Z
IL-6
TNFalpha
Umbilical circulation
Term labour
Early Human Development
Early Human Development
86
2
113
117
http://dx.doi.org/10.1016/j.earlhumdev.2010.01.027
Medical Physiology
Obstetrics and Gynecology
Pediatrics
<p>OBJECTIVE: We have determined venous and arterial cord blood levels for IL-6 and TNFalpha at the time of delivery to assess gestational tissue versus fetal sources in labouring and non-labouring patients at term, and the relationship to labour events. METHODS: Fifty-five patients were studied (elective cesarean section n=24, and labouring n=31) with blood sampling from a clamped segment of cord after delivery of the fetus and from the cord at its insertion into the placenta after delivery of the placenta, with subsequent measurement of blood gases, pH, IL-6 and TNFalpha. RESULTS: Umbilical cord levels for IL-6 were increased by 4 fold in low risk labouring patients, and a further 6 fold when showing histologic chorioamnionitis, but with no evident effect of nuchal cord with 'variable' fetal heart rate decelerations, fetal acidemia, nor of labour duration. IL-6 levels from the cord at its insertion into the placenta were generally higher than those from the respective umbilical levels indicating that placental release of IL-6 into cord blood must be occurring. However, a consistent venoarterial difference for IL-6 and thereby a net flux from the placenta could not be demonstrated. TNFalpha levels for both patient groups were uniformly low for all of the cord measurements with no significant differences noted. CONCLUSION: Umbilical cord levels for IL-6 are increased in low risk labouring patients at term in the absence of evident infection which likely involves both gestational tissue and fetal contributions. Cord levels for IL-6 are further increased in low risk labouring patients showing histologic chorioamnionitis which might then contribute to newborn morbidity in these pregnancies.</p>
https://ir.lib.uwo.ca/obsgynpub/6
oai:ir.lib.uwo.ca:vascularpub-1046
2010-04-05T21:18:55Z
publication:vascularpub
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:robarts
publication:institutes
20214792
Human Cord Blood Progenitors with High Aldehyde Dehydrogenase Activity Improve Vascular Density in a Model of Acute Myocardial Infarction
Sondergaard, Claus S.
Hess, David A.
Maxwell, Dustin J.
Weinheimer, Carla
Rosová, Ivana
Creer, Michael H.
Piwnica-Worms, David
Kovacs, Attila
Pedersen, Lene
Nolta, Jan A.
Article
2010-03-09T08:00:00Z
blood progenitors
aldehyde dehydrogenase
vascular density
acute myocardial infarction
Journal of Translational Medicine
8
24
http://dx.doi.org/10.1186/1479-5876-8-24
Cardiology
Human stem cells from adult sources have been shown to contribute to the regeneration of muscle, liver, heart, and vasculature. The mechanisms by which this is accomplished are, however, still not well understood. We tested the engraftment and regenerative potential of human umbilical cord blood-derived ALDH(hi)Lin(-), and ALDH(lo)Lin(-) cells following transplantation to NOD/SCID or NOD/SCID beta2m null mice with experimentally induced acute myocardial infarction. We used combined nanoparticle labeling and whole organ fluorescent imaging to detect human cells in multiple organs 48 hours post transplantation. Engraftment and regenerative effects of cell treatment were assessed four weeks post transplantation. We found that ALDH(hi)Lin(-) stem cells specifically located to the site of injury 48 hours post transplantation and engrafted the infarcted heart at higher frequencies than ALDH(lo)Lin(-) committed progenitor cells four weeks post transplantation. We found no donor derived cardiomyocytes and few endothelial cells of donor origin. Cell treatment was not associated with any detectable functional improvement at the four week endpoint. There was, however, a significant increase in vascular density in the central infarct zone of ALDH(hi)Lin(-) cell-treated mice, as compared to PBS and ALDH(lo)Lin(-) cell-treated mice.
CONCLUSIONS: Our data indicate that adult human stem cells do not become a significant part of the regenerating tissue, but rapidly home to and persist only temporarily at the site of hypoxic injury to exert trophic effects on tissue repair thereby enhancing vascular recovery.
https://ir.lib.uwo.ca/vascularpub/47
oai:ir.lib.uwo.ca:mbrainpub-1005
2010-06-12T02:04:41Z
publication:physpharmpub
publication:pmid
publication:cns
publication:faculties
publication:cnspub
publication:physpharm
publication:mbrainpub
publication:robarts
publication:institutes
20409323
Rapid and Direct Transport of Cell Surface APP to the Lysosome Defines a Novel Selective Pathway
Lorenzen, Angela
Samosh, Jonathan
Vandewark, Kenneth
Anborgh, Pieter H.
Seah, Claudia
Magalhaes, Ana C.
Cregan, Sean P.
Ferguson, Stephen S. G.
Pasternak, Stephen H.
Article
2010-04-21T07:00:00Z
Alzheimer's disease
amyloid precursor protein
APP
Lysosome
Molecular Brain
Molecular Brain
3
11
http://dx.doi.org/10.1186/1756-6606-3-11
Medical Neurobiology
Molecular and Cellular Neuroscience
Neurology
Neurosciences
BACKGROUND: A central feature of Alzheimer's disease is the cleavage of the amyloid precursor protein (APP) to form beta-amyloid peptide (Abeta) by the beta-secretase and gamma-secretase enzymes. Although this has been shown to occur after endocytosis of APP from the cell surface, the exact compartments of APP processing are not well defined. We have previously demonstrated that APP and gamma-secretase proteins and activity are highly enriched in purified rat liver lysosomes. In order to examine the lysosomal distribution and trafficking of APP in cultured cells, we generated constructs containing APP fused to a C-terminal fluorescent protein tag and N-terminal HA-epitope tag. These were co-transfected with a panel of fluorescent-protein tagged compartment markers.
RESULTS: Here we demonstrate using laser-scanning confocal microscopy that although APP is present throughout the endosomal/lysosomal system in transfected Cos7 and neuronal SN56 cell lines as well as in immunostained cultured mouse neurons, it is enriched in the lysosome. We also show that the Swedish and London mutations reduce the amount of APP in the lysosome. Surprisingly, in addition to its expected trafficking from the cell surface to the early and then late endosomes, we find that cell-surface labelled APP is transported rapidly and directly from the cell surface to lysosomes in both Cos7 and SN56 cells. This rapid transit to the lysosome is blocked by the presence of either the London or Swedish mutations.
CONCLUSIONS: These results demonstrate the presence of a novel, rapid and specific transport pathway from the cell surface to the lysosomes. This suggests that regulation of lysosomal traffic could regulate APP processing and that the lysosome could play a central role in the pathophysiology of Alzheimer's disease.
https://ir.lib.uwo.ca/mbrainpub/6
oai:ir.lib.uwo.ca:physpharmpub-1033
2011-05-04T00:17:54Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
20416102
De Novo Sequencing and Analysis of the American Ginseng Root Transcriptome Using a GS FLX Titanium Platform to Discover Putative Genes Involved in Ginsenoside Biosynthesis
Sun, Chao
Li, Ying
Wu, Qiong
Luo, Hongmei
Sun, Yongzhen
Song, Jingyuan
Lui, Edmund M. K.
Chen, Shilin
Article
2010-04-24T07:00:00Z
American ginseng root transcriptome
ginsenoside biosynthesis
BMC Genomics
BMC Genomics
11
262
http://dx.doi.org/10.1186/1471-2164-11-262
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>BACKGROUND: American ginseng (Panax quinquefolius L.) is one of the most widely used herbal remedies in the world. Its major bioactive constituents are the triterpene saponins known as ginsenosides. However, little is known about ginsenoside biosynthesis in American ginseng, especially the late steps of the pathway. RESULTS: In this study, a one-quarter 454 sequencing run produced 209,747 high-quality reads with an average sequence length of 427 bases. De novo assembly generated 31,088 unique sequences containing 16,592 contigs and 14,496 singletons. About 93.1% of the high-quality reads were assembled into contigs with an average 8-fold coverage. A total of 21,684 (69.8%) unique sequences were annotated by a BLAST similarity search against four public sequence databases, and 4,097 of the unique sequences were assigned to specific metabolic pathways by the Kyoto Encyclopedia of Genes and Genomes. Based on the bioinformatic analysis described above, we found all of the known enzymes involved in ginsenoside backbone synthesis, starting from acetyl-CoA via the isoprenoid pathway. Additionally, a total of 150 cytochrome P450 (CYP450) and 235 glycosyltransferase unique sequences were found in the 454 cDNA library, some of which encode enzymes responsible for the conversion of the ginsenoside backbone into the various ginsenosides. Finally, one CYP450 and four UDP-glycosyltransferases were selected as the candidates most likely to be involved in ginsenoside biosynthesis through a methyl jasmonate (MeJA) inducibility experiment and tissue-specific expression pattern analysis based on a real-time PCR assay. CONCLUSIONS: We demonstrated, with the assistance of the MeJA inducibility experiment and tissue-specific expression pattern analysis, that transcriptome analysis based on 454 pyrosequencing is a powerful tool for determining the genes encoding enzymes responsible for the biosynthesis of secondary metabolites in non-model plants. Additionally, the expressed sequence tags (ESTs) and unique sequences from this study provide an important resource for the scientific community that is interested in the molecular genetics and functional genomics of American ginseng.</p>
https://ir.lib.uwo.ca/physpharmpub/34
oai:ir.lib.uwo.ca:obsgynpub-1007
2010-06-21T00:03:30Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
20453524
Cerebral Protein Synthesis in the Ovine Fetus Near Term with Amino Acid Infusion and Insulin-Induced Hypoaminoacidemia.
Maclachlan, James N.
McCallum, Jeremy D.
Smith, Norman
Matushewski, Brad
Richardson, Bryan S.
Article
2010-05-04T07:00:00Z
Fetal sheep
Cerebral protein synthesis
Amino acids
Insulin
Neonatology
Neonatology
98
4
297
304
http://dx.doi.org/10.1159/000291416
Medical Biochemistry
Medical Pharmacology
Medical Physiology
Obstetrics and Gynecology
Background: Studies during early development have shown that the precursor availability of amino acids directly affects protein synthesis both at the whole-body level and for select organ tissues, although this has not been studied for the brain.
Objective: We utilized a mixed amino acid infusate and an insulin euglycemic clamp technique in the ovine fetus near term, with increases and decreases in circulating amino acid levels of approximately 30 to 40% on average, and determined the impact on cerebral protein synthesis. Methods: Fetal sheep received a 6-hour infusion of Primene(R) 10% (amino acid infusate group) or a co-infusion of insulin and 10% dextrose (insulin/dextrose infusate group) together with a continuous infusion of L-[1-(13)C]-leucine. Measurements were obtained for fetal plasma leucine enrichment at steady-state and brain tissue intracellular free and protein-bound leucine enrichment at necropsy, followed by the determination of cerebral protein fractional synthetic rates (FSR).
Results: Protein FSR for the cerebral cortex averaged approximately 58 and approximately 39%/day when using the intracellular free and plasma enrichment values for the precursor pool measurements, respectively, providing for maximal and minimal FSR values, and with little difference between the amino acid and insulin/dextrose groups, although significantly higher than respective values for the cerebellum.
Conclusion: Accordingly, there was no evidence of a differential effect of increases versus decreases in circulating amino acids on cerebral protein synthesis as studied, which may be attributed to the saturable nature of the blood-brain barrier transporters for amino acids.
https://ir.lib.uwo.ca/obsgynpub/8
oai:ir.lib.uwo.ca:chempub-1020
2010-06-21T01:08:21Z
publication:robartspub
publication:biophysicspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:mbrainpub
publication:chempub
publication:robarts
publication:biochem
publication:institutes
publication:chem
20485791
A Paramagnetic Chemical Exchange-based MRI Probe Metabolized by Cathepsin D: Design, Synthesis and Cellular Uptake Studies
Suchý, Mojmír
Ta, Robert
Li, Alex X.
Wojciechowski, Filip
Pasternak, Stephen H.
Bartha, Robert
Hudson, Robert H. E.
Article
2010-06-07T07:00:00Z
Cathepsin D
MRI
Organic & Biomolecular Chemistry
Organic & Biomolecular Chemistry
8
11
2560
2566
http://dx.doi.org/10.1039/b926639a
Biochemistry, Biophysics, and Structural Biology
Chemistry
Medical Biophysics
Medical Pharmacology
Medical Physiology
Overexpression of the aspartyl protease cathepsin D is associated with certain cancers and Alzheimer's disease; thus, it is a potentially useful imaging biomarker for disease. A dual fluorescence/MRI probe for the potential detection of localized cathepsin D activity has been synthesized. The probe design includes both MRI and optical reporter groups connected to a cell penetrating peptide by a cathepsin D cleavable sequence. This design results in the selective intracellular deposition (determined fluorimetrically) of the MRI and optical reporter groups in the presence of overexpressed cathepsin D. The probe also provided clearly detectable in vitro MRI contrast by the mechanism of paramagnetic chemical exchange effects (OPARACHEE).
https://ir.lib.uwo.ca/chempub/21
oai:ir.lib.uwo.ca:biochempub-1107
2010-07-05T23:23:19Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
20233719
Mammalian Numb-interacting Protein 1/Dual Oxidase Maturation Factor 1 Directs Neuronal Fate in Stem Cells
Kennedy, Karen A. M.
Ostrakhovitch, Elena A.
Sandiford, Shelley D. E.
Dayarathna, Thamara
Xie, Xiaojun
Waese, Elaine Y. L.
Chang, Wing Y.
Feng, Qingping
Skerjanc, Ilona S.
Stanford, William L.
Li, Shawn S. C.
Article
2010-06-04T07:00:00Z
Animals
Brain
Cell Line
Tumor
Cell Lineage
Cytoskeleton
Lamin Type A
Mice
NADPH Oxidase
Neurons
Nuclear Cap-Binding Protein Complex
Phenotype
RNA
Small Interfering
Reactive Oxygen Species
Stem Cells
Journal of Biological Chemistry
285
23
17974
17985
http://dx.doi.org/10.1074/jbc.M109.084616
Biochemistry
Medical Physiology
In this study, we describe a role for the mammalian Numb-interacting protein 1 (Nip1) in regulation of neuronal differentiation in stem cells. The expression of Nip1 was detected in the developing mouse brain, embryonic stem cells, primary neuronal stem cells, and retinoic acid-treated P19 embryonal carcinoma cells. The highest expression of Nip1 was observed in undifferentiated neuronal stem cells and was associated with Duox1-mediated reactive oxygen species ROS production. Ectopic nip1 expression in P19 embryonal carcinoma cells induced neuronal differentiation, and this phenotype was also linked to elevated ROS production. The neuronal differentiation in nip1-overexpressing P19 cells was achieved in a retinoic acid-independent manner and was corroborated by an increase in the expression of the neuronal basic helix-loop-helix transcription factors and neural-lineage cell markers. Furthermore, depletion of nip1 by short hairpin RNA led to a decrease in the expression of neuronal basic helix-loop-helix transcription factors and ROS. However, inhibition of ROS production in nip1-overexpressing P19 cells restricted but did not extinguish neuronal differentiation. Microarray and mass spectrometry analysis identified intermediate filaments as the principal cytoskeletal elements affected by up-regulation of nip1. We show here the first evidence for a functional interaction between Nip1 and a component of the nuclear lamina, lamin A/C. associated with a neuronal-specific phenotype. Taken together, our data reveal an important role for Nip1 in the guidance of neuronal differentiation through ROS generation and modulation of intermediate filaments and implicate Nip1 as a novel intrinsic regulator of neuronal cell fate.
https://ir.lib.uwo.ca/biochempub/105
oai:ir.lib.uwo.ca:dentistrypub-1023
2010-07-08T00:24:23Z
publication:physpharmpub
publication:dentistrypub
publication:pmid
publication:faculties
publication:physpharm
publication:dentistry
20507556
Towards an Anti-fibrotic Therapy for Scleroderma: Targeting Myofibroblast Differentiation and Recruitment
Leask, Andrew
Article
2010-05-27T07:00:00Z
Anti-fibrotic therapy
Scleroderma
Myofibroblast
Fibrogenesis & Tissue Repair
Fibrogenesis & Tissue Repair
3
8
http://dx.doi.org/10.1186/1755-1536-3-8
Dentistry
Medical Physiology
BACKGROUND: In response to normal tissue injury, fibroblasts migrate into the wound where they synthesize and remodel new extracellular matrix. The fibroblast responsible for this process is called the myofibroblast, which expresses the highly contractile protein alpha-smooth muscle actin (alpha-SMA). In normal tissue repair, the myofibroblast disappears. Conversely, abnormal myofibroblast persistence is a key feature of fibrotic dieases, including scleroderma (systemic sclerosis, SSc). Myofibroblasts can be derived from differentiation of local resident fibroblasts or by recruitment of microvascular pericytes.
CLINICAL PROBLEM ADDRESSED: Controlling myofibroblast differentiation and persistence is crucial for developing anti-fibrotic therapies targeting SSc.
BASIC SCIENCE ADVANCES: Insights have been recently generated into how the proteins transforming growth factor beta (TGFbeta), endothelin-1 (ET-1), connective tissue growth factor (CCN2/CTGF) and platelet derived growth factor (PDGF) contribute to myofibroblast differentiation and pericyte recruitment in general and to the persistent myofibroblast phenotype of lesional SSc fibroblast, specifically.
RELEVANCE TO CLINICAL CARE: This minireview summarizes recent findings pertinent to the origin of myofibroblasts in SSc and how this knowledge might be used to control the fibrosis in this disease.
CONCLUSIONS: TGFbeta, ET-1, CCN2 and PDGF are likely to cooperate in driving tissue repair and fibrogenic responses in fibroblasts. TGFbeta, ET-1 and CCN2 appear to contribute to myofibroblast differentiation; PDGF appears to be involved with pericyte recruitment. Thus, different therapeutic strategies may exist for targeting the multisystem fibrotic disorder SSc.
https://ir.lib.uwo.ca/dentistrypub/23
oai:ir.lib.uwo.ca:physicspub-1001
2018-02-15T20:20:04Z
publication:physics
publication:physpharmpub
publication:chemengpub
publication:pmid
publication:faculties
publication:physicspub
publication:physpharm
publication:biochempub
publication:chemeng
publication:biochem
20560559
Controlled Deposition of Highly Oriented Type I Collagen Mimicking In Vivo Collagen Structures
Tenboll, Annabell
Darvish, Behafarid
Hou, Weimin
Duwez, Anne-Sophie
Dixon, S. Jeffrey
Goldberg, Harvey A.
Grohe, Bernd
Mittler, Silvia
Article
2010-07-20T07:00:00Z
Collagen
In Vivo Collagen
Langmuir
Langmuir
26
14
12165
12172
http://dx.doi.org/10.1021/la1018136
Biochemistry, Biophysics, and Structural Biology
Biomedical Engineering and Bioengineering
Physics
Physiology
<p>The structural arrangement of type I collagen in vivo is critical for the normal functioning of tissues, such as bone, cornea, and blood vessels. At present, there are no low-cost techniques for fabricating aligned collagen structures for applications in regenerative medicine. Here, we report a straightforward approach to fabricate collagen films, with defined orientation of collagen fibrillar aggregates within a matrix of oriented collagen molecules. Langmuir−Blodgett (LB) technology was used to deposit thin films of oriented type I collagen onto substrates. It was found that collagen does not behave like classical LB materials, such as amphiphilic hydrocarbon acids or lipids. The thickness of the deposited collagen films and the area-pressure isotherms were found to depend on the amount of material spread. In addition, no film collapse was detected and the deposited LB films were thicker than the theoretical dimension of a collagen monolayer (1.5 nm) formed by triple helical collagen molecules. Individual LB films with thicknesses of up to 20 nm were obtained, and multiple depositions yielded overall film thicknesses of up to 100 nm. Films consisted of a matrix of collagen molecules containing thicker fibrillar aggregates of collagen (micrometers in length). These fibrillar aggregates were built up of shorter unit molecules forming “spun thread” structures, some of which exhibited a zigzag pattern. In addition to aligning collagen unidirectionally (similar for example to tendon), we performed a two-step deposition procedure, in which the substrate was turned 90° between two consecutive collagen deposition steps. The resulting films showed orthogonally aligned collagen layers, mimicking the structure of cornea. Thus, this technique permits control of the thickness of individual layers, the orientation of successive layers, and the number of layers within the construct. Therefore, it may have widespread applicability for the engineering of collagen-rich tissues.</p>
https://ir.lib.uwo.ca/physicspub/2
oai:ir.lib.uwo.ca:ptpub-1023
2010-08-07T21:49:41Z
publication:pt
publication:physpharmpub
publication:faculties
publication:physpharm
publication:ptpub
Influence of Age and Gender of Healthy Adults on Scoring Patterns on the Community Balance and Mobility Scale
Rocque, Rohini
Bartlett, Doreen
Brown, Janet
Garland, S. Jayne
Article
2005-01-01T08:00:00Z
Age
Balance
Gender
Mobility
Outcome measure
Physiotherapy Canada
Physiotherapy Canada
57
4
285
292
http://dx.doi.org/10.3138/ptc.57.4.285
Physical Therapy
Purpose: The purpose of the study was to describe and compare scoring patterns on the Community Balance and Mobility Scale (CB&M) in healthy men and women between 30 and 59 years of age.
Methods: Following criterion testing on 5 individuals, 90 healthy volunteers who met the inclusion criteria and consented to participate in the study were tested on the CB&M. The subjects were recruited through quota sampling in three age categories: 30 to 39 years, 40 to 49 years, and 50 to 59 years, with 15 men and 15 women in each age category. The groups were not matched for any anthropometric variables.
Results: Women within the age category of 50 to 59 years had significantly lower scores on the CB&M compared with all other age and gender categories.
Conclusions: The results from this study indicate that although the items on the CB&M were appropriate for the 30- to 59-year age categories, some items still posed a challenge to healthy participants because most were unable to score full points on the CB&M. The normative data from the present study could help clinicians put the CB&M scores of middle-aged patients into context. These data may also be useful in making recommendations regarding the safe integration of patients back into the community following mild stroke.
https://ir.lib.uwo.ca/ptpub/24
oai:ir.lib.uwo.ca:physpharmpub-1034
2010-08-30T06:17:15Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
20566646
Synthetic Triterpenoids Target the Arp2/3 Complex and Inhibit Branched Actin Polymerization
To, Ciric
Shilton, Brian H.
Di Guglielmo, Gianni M.
Article
2010-09-03T07:00:00Z
Actin
Cdc42
Cell Migration
Cytoskeleton
Mass Spectrometry
The Journal of Biological Chemistry
The Journal of Biological Chemistry
285
36
27944
27957
http://dx.doi.org/10.1074/jbc.M110.103036
Biochemistry, Biophysics, and Structural Biology
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Synthetic triterpenoids are anti-tumor agents that affect numerous cellular functions including apoptosis and growth inhibition. Here, we used mass spectrometric and protein array approaches and uncovered that triterpenoids associate with proteins of the actin cytoskeleton, including Actin-related protein 3 (Arp3). Arp3, a subunit of the Arp2/3 complex, is involved in branched actin polymerization and the formation of lamellipodia. CDDO-Im and CDDO-Me were observed to 1) inhibit the localization of Arp3 and actin at the leading edge of cells, 2) abrogate cell polarity and 3) inhibit Arp2/3-dependent branched actin polymerization. We confirmed our drug effects with siRNA targeting of Arp3 and observed a decrease in Rat2 cell migration. Taken together, our data suggest that synthetic triterpenoids target Arp3 and branched actin polymerization to inhibit cell migration.
https://ir.lib.uwo.ca/physpharmpub/35
oai:ir.lib.uwo.ca:physpharmpub-1035
2010-09-08T00:00:37Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:med
publication:physpharm
20812871
Hair Cortisol and the Risk for Acute Myocardial Infarction in Adult Men
Pereg, David
Gow, Rachel
Mosseri, Morris
Lishner, Michael
Rieder, Michael
Van Uum, Stan
Koren, Gideon
Article
2010-09-02T07:00:00Z
Acute myocardial infarction
Chronic stress
Cortisol
Hair
HPA-axis
Glucocorticoids
Stress
Stress
http://dx.doi.org/10.3109/10253890.2010.511352
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Acute stress is increasingly recognized as a precipitant of acute myocardial infarction (AMI). However, the role of chronic stress in developing AMI is less clear. We have developed a method to measure cortisol in hair, which allows longitudinal assessment of cortisol levels prior to an acute event. We aimed to evaluate the hypothesis that chronic stress, as assessed by hair cortisol content, is associated with the development of AMI. A prospective case-control study included 56 patients admitted to hospital with AMI and 56 control patients, admitted to internal medicine wards for other indications. An enzyme immunoassay technique was used to measure cortisol in the most proximal 3 cm of hair, considered to represent the most recent 3 months of exposure. Median hair cortisol contents (range) were 295.3 (105.4-809.3)ng/g in AMI patients and 224.9 (76.58-949.9)ng/g in controls (p = 0.006, Mann-Whitney U-test). After controlling for other risk factors for AMI using multiple logistic regression, log-transformed hair cortisol content remained the strongest predictor (OR 17.4, 95% CI 2.15-140.5; p = 0.007). We demonstrated elevated hair cortisol concentrations in patients with AMI. This suggests that chronic stress, as assessed by increased hair cortisol in the 3 months prior to the event, may be a contributing factor for AMI.
https://ir.lib.uwo.ca/physpharmpub/36
oai:ir.lib.uwo.ca:physpharmpub-1036
2010-10-13T00:28:49Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:psychologypub
publication:psychology
20935644
Cross-modal Plasticity in Specific Auditory Cortices Underlies Visual Compensations in the Deaf
Lomber, Stephen G.
Meredith, M. Alex
Kral, Andrej
Article
2010-10-10T07:00:00Z
Cross-modal plasticity
Auditory cortices
Visual compensations
Deaf
Nature Neuroscience
Nature Neuroscience
http://dx.doi.org/10.1038/nn.2653
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Psychology
When the brain is deprived of input from one sensory modality, it often compensates with supranormal performance in one or more of the intact sensory systems. In the absence of acoustic input, it has been proposed that cross-modal reorganization of deaf auditory cortex may provide the neural substrate mediating compensatory visual function. We tested this hypothesis using a battery of visual psychophysical tasks and found that congenitally deaf cats, compared with hearing cats, have superior localization in the peripheral field and lower visual movement detection thresholds. In the deaf cats, reversible deactivation of posterior auditory cortex selectively eliminated superior visual localization abilities, whereas deactivation of the dorsal auditory cortex eliminated superior visual motion detection. Our results indicate that enhanced visual performance in the deaf is caused by cross-modal reorganization of deaf auditory cortex and it is possible to localize individual visual functions in discrete portions of reorganized auditory cortex.
https://ir.lib.uwo.ca/physpharmpub/37
oai:ir.lib.uwo.ca:kinpub-1008
2010-11-22T01:33:11Z
publication:vascularpub
publication:kin
publication:physpharmpub
publication:pmid
publication:faculties
publication:medpub
publication:kinpub
publication:med
publication:physpharm
publication:biochempub
publication:robarts
publication:biochem
publication:institutes
20732959
Increased Blood Pressure and Hyperdynamic Cardiovascular Responses in Carriers of a Common Hyperfunctional Variant of Adenylyl Cyclase 6
Hodges, Gary J.
Gros, Robert
Hegele, Robert A.
Van Uum, Stan
Shoemaker, J. Kevin
Feldman, Ross D.
Article
2010-11-01T07:00:00Z
Blood Pressure
Hyperdynamic Cardiovascular Response
Adenylyl Cyclase 6
The Journal of Pharmacology and Experimental Therapeutics
The Journal of Pharmacology and Experimental Therapeutics
335
2
451
457
http://dx.doi.org/10.1124/jpet.110.172700
Cardiology
Kinesiology
Medical Physiology
Adenylyl cyclase (ADCY) is a critical regulator of metabolic and cardiovascular function. We have identified a genetic variant (A674S) in ADCY isoform 6 (ADCY6). Subsequent studies demonstrated that the expression of this ADCY6 variant paralleled an increase in adenylyl cyclase-mediated functions. However, the impact of this hyperfunctional variant on cardiovascular function is unknown. Therefore, we evaluated the hemodynamic profile of carriers of ADCY6 A674S. The association of ADCY6 A674S with anthropometric and hemodynamic parameters was assessed in 364 healthy white subjects. The allele encoding this variant was present in 6.9% of the subjects, and those individuals had increased blood pressure. To determine the hemodynamic basis for increased blood pressure in carriers of ADCY6 A674S, we assessed forearm blood flow (FBF) and cardiac output at rest, during handgrip exercise (to test vasodilator responsiveness), and with lower body negative pressure [to test forearm vasoconstrictor and heart rate (HR) responsiveness] in a subsample of 21 subjects. At rest, cardiac output and blood pressure were higher in carriers of ADCY6 A674S. This was paralleled by an increase in plasma renin activity, but not in plasma norepinephrine. During handgrip exercise, FBF and vasodilator responses were greater in carriers of ADCY6 A674S. Responses to reactive hyperemia were not different between genotypes. With lower body negative pressure, the HR response to this orthostatic stress was markedly higher in carriers of ADCY6 A674S. These data indicate that the relatively common hyperfunctional ADCY6 A674S variant underlies a hyperdynamic cardiovascular response and increased blood pressure.
https://ir.lib.uwo.ca/kinpub/9
oai:ir.lib.uwo.ca:surgerypub-1111
2010-12-07T03:29:59Z
publication:biophysicspub
publication:physpharmpub
publication:surgerypub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:biochem
publication:surgery
20856684
Molecular Mechanisms and Treatment Strategies for Dupuytren's Disease
O'Gorman, David B.
Vi, Linda
Gan, Bing Siang
Article
2010-09-07T07:00:00Z
Dupuytren’s contracture
Dupuytren’s disease
Fibrosis
Therapeutics and Clinical Risk Management
6
383
390
http://dx.doi.org/10.2147/TCRM.S9165
Medical Biochemistry
Medical Biophysics
Medical Physiology
Surgery
Dupuytren's disease (DD) is a common disease of the hand and is characterized by thickening of the palmar fascia and formation of tight collagenous disease cords. At present, the disease is incurable and the molecular pathophysiology of DD is unknown. Surgery remains the most commonly used treatment for DD, but this requires extensive postoperative therapy and is associated with high rates of recurrence. Over the past decades, more indepth exploration of the molecular basis of DD has raised the hopes of developing new treatment modalities. This paper reviews the clinical presentation and molecular pathophysiology of this disease, as well as current and emerging treatment. It also explores the implications of new findings in the laboratory for future treatment.
https://ir.lib.uwo.ca/surgerypub/109
oai:ir.lib.uwo.ca:chemengpub-1000
2010-12-07T02:33:12Z
publication:physpharmpub
publication:dentistrypub
publication:chemengpub
publication:pmid
publication:faculties
publication:physpharm
publication:dentistry
publication:biochempub
publication:chemeng
publication:biochem
20730931
Modification of Polymer Networks with Bone Sialoprotein Promotes Cell Attachment and Spreading
Chan, Wailen D.
Goldberg, Harvey A.
Hunter, Graeme K.
Dixon, S. J.
Rizkalla, Amin S.
Article
2010-09-01T07:00:00Z
PCL/pHEMA
Bone sialoprotein
Osseous tissue engineering
Journal of Biomedical Materials Research Part A
Journal of Biomedical Materials Research Part A
94A
3
945
952
http://dx.doi.org/10.1002/jbm.a.32715
Biomedical Engineering and Bioengineering
Chemical Engineering
Medical Physiology
Biomaterials used for tissue engineering scaffolds act as temporary substrates, on which cells deposit newly synthesized extracellular matrix. In cartilage tissue engineering, polycaprolactone/poly(2-hydroxyethyl methacrylate) (PCL/pHEMA) polymer blends have been used as scaffold materials, but their use in osseous tissue engineering has been more limited. The objective of this study was to evaluate modification of PCL/pHEMA surfaces with bone sialoprotein (BSP), an extracellular matrix protein important in regulating osseous tissue formation. Modification of surfaces with BSP significantly enhanced osteoblastic cell attachment and spreading, without compromising proliferation. Thus, BSP-immobilization may be a useful strategy for optimizing scaffolds for skeletal tissue engineering.
https://ir.lib.uwo.ca/chemengpub/1
oai:ir.lib.uwo.ca:mbrainpub-1006
2011-03-12T02:09:33Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:mbrainpub
publication:robarts
publication:institutes
21122141
The Modulation of TRPM7 Currents by Nafamostat Mesilate Depends Directly upon Extracellular Concentrations of Divalent Cations
Chen, Xuanmao
Numata, Tomohiro
Li, Minghua
Mori, Yasuo
Orser, Beverley A.
Jackson, Michael F.
Xiong, Zhi-Gang
MacDonald, John F.
Article
2010-12-01T08:00:00Z
Modulation
TRPM7 currents
Nafamostat mesilate
Extracellular concentration
Divalent cation
Molecular Brain
Molecular Brain
3
38
http://dx.doi.org/10.1186/1756-6606-3-38
Medical Neurobiology
Molecular and Cellular Neuroscience
Neurology
Neurosciences
<p>Concentrations of extracellular divalent cations (Ca2+ and Mg2+) fall substantially during intensive synaptic transmission as well as during some pathophysiological conditions such as epilepsy and brain ischemia. Here we report that a synthetic serine protease inhibitor, nafamostat mesylate (NM), and several of its analogues, block recombinant TRPM7 currents expressed in HEK293T cells in inverse relationship to the concentration of extracellular divalent cations. Lowering extracellular Ca2+ and Mg2+ also evokes a divalent-sensitive non-selective cation current that is mediated by TRPM7 expression in hippocampal neurons. In cultured hippocampal neurons, NM blocked these TRPM7-mediated currents with an apparent affinity of 27 μM, as well as the paradoxical Ca2+ influx associated with lowering extracellular Ca2+. Unexpectedly, pre-exposure to NM strongly potentiated TRPM7 currents. In the presence of physiological concentrations of extracellular divalent cations, NM activates TRPM7. The stimulating effects of NM on TRPM7 currents are also inversely related to extracellular Ca2+ and Mg2+. DAPI and HSB but not netropsin, blocked and stimulated TRPM7. In contrast, mono-cationic, the metabolites of NM, p-GBA and AN, as well as protease inhibitor leupeptin and gabexate failed to substantially modulate TRPM7. NM thus provides a molecular template for the design of putative modulators of TRPM7.</p>
https://ir.lib.uwo.ca/mbrainpub/7
oai:ir.lib.uwo.ca:physpharmpub-1037
2011-04-21T00:53:53Z
publication:physpharmpub
publication:dentistrypub
publication:pmid
publication:faculties
publication:physpharm
publication:dentistry
21266028
mPGES-1 Null Mice Are Resistant to Bleomycin-induced Skin Fibrosis
McCann, Matthew R.
Monemdjou, Roxana
Ghassemi-Kakroodi, Parisa
Fahmi, Hassan
Perez, Gemma
Liu, Shangxi
Shi-Wen, Xu
Parapuram, Sunil K
Kojima, Fumiaki
Denton, Christopher P
Abraham, David J
Martel-Pelletier, Johanne
Crofford, Leslie J
Leask, Andrew
Kapoor, Mohit
Article
2011-01-25T08:00:00Z
mPGES-1
Bleomycin-induced skin fibrosis
Arthritis Research & Therapy
Arthritis Research & Therapy
13
6
http://dx.doi.org/10.1186/ar3226
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>INTRODUCTION: Microsomal prostaglandin E2 synthase-1 (mPGES-1) is an inducible enzyme that acts downstream of cyclooxygenase (COX) to specifically catalyze the conversion of prostaglandin (PG) H2 to PGE2. mPGES-1 plays a key role in inflammation, pain and arthritis; however, the role of mPGES-1 in fibrogenesis is largely unknown. Herein, we examine the role of mPGES-1 in a mouse model of skin scleroderma using mice deficient in mPGES-1.</p>
<p>METHODS: Wild type (WT) and mPGES-1 null mice were subjected to the bleomycin model of cutaneous skin scleroderma. mPGES-1 expressions in scleroderma fibroblasts and in fibroblasts derived from bleomycin-exposed mice were assessed by Western blot analysis. Degree of fibrosis, dermal thickness, inflammation, collagen content and the number of α-smooth muscle actin (α-SMA)-positive cells were determined by histological analyses. The quantity of the collagen-specific amino acid hydroxyproline was also measured.</p>
<p>RESULTS: Compared to normal skin fibroblasts, mPGES-1 protein expression was elevated in systemic sclerosis (SSc) fibroblasts and in bleomycin-exposed mice. Compared to WT mice, mPGES-1-null mice were resistant to bleomycin-induced inflammation, cutaneous thickening, collagen production and myofibroblast formation.</p>
<p>CONCLUSIONS: mPGES-1 expression is required for bleomycin-induced skin fibrogenesis. Inhibition of mPGES-1 may be a viable method to alleviate the development of cutaneous sclerosis and is a potential therapeutic target to control the onset of fibrogenesis.</p>
<p>Correction to this article is available at: <a href="http://dx.doi.org/10.1186/ar3285">http://dx.doi.org/10.1186/ar3285</a></p>
https://ir.lib.uwo.ca/physpharmpub/38
oai:ir.lib.uwo.ca:scsdpub-1001
2011-04-09T04:19:19Z
publication:kin
publication:rwkex_researcharticles
publication:physpharmpub
publication:pmid
publication:cns
publication:faculties
publication:cnspub
publication:rwkex
publication:kinpub
publication:physpharm
publication:scsdpub
publication:scsd
21294905
Stuttered Swallowing: Electric Stimulation of the Right Insula Interferes with Water Swallowing. A Case Report
Sörös, Peter
Al-Otaibi, Faisal
Wong, Savio W. H.
Shoemaker, J. Kevin
Mirsattari, Seyed M.
Hachinski, Vladimir
Martin, Ruth E.
Article
2011-02-05T08:00:00Z
Stuttered swallowing
Electric stimulation
Insula
Water swallowing
BMC Neurology
BMC Neurology
11
20
http://dx.doi.org/10.1186/1471-2377-11-20
Communication Sciences and Disorders
Kinesiology
Medical Physiology
Neurology
<p>BACKGROUND: Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear.</p>
<p>CASE PRESENTATION: Invasive electroencephalographic monitoring was performed in a 24-year-old man with medically intractable stereotyped nocturnal hypermotor seizures due to a ganglioglioma. During stimulation of the right inferior posterior insular cortex with depth electrodes the patient spontaneously reported a perception of a "stutter in swallowing". Stimulation of the inferior posterior insular cortex at highest intensity (4 mA) was also associated with irregular and delayed swallows. Swallowing was not impaired during stimulation of the superior posterior insular cortex, regardless of stimulation intensity.</p>
<p>CONCLUSIONS: These results indicate that the right inferior posterior insular cortex is involved in the neural circuitry underlying the control of swallowing.</p>
https://ir.lib.uwo.ca/scsdpub/2
oai:ir.lib.uwo.ca:physpharmpub-1038
2011-04-21T01:18:34Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
21453480
Thrombospondin 1 Is a Key Mediator of Transforming Growth Factor β-mediated Cell Contractility in Systemic Sclerosis via a Mitogen-activated Protein Kinase Kinase (MEK)/Extracellular Signal-regulated Kinase (ERK)-dependent Mechanism
Chen, Yunliang
Leask, Andrew
Abraham, David J.
Kennedy, Laura
Xu, Shi-wen
Denton, Christopher P.
Black, Carol M.
Verjee, Liaquat S.
Eastwood, Mark
Article
2011-03-31T07:00:00Z
Thrombospondin 1
β-mediated cell contractility
Systemic sclerosis
Protein kinase
Fibrogenesis & Tissue Repair
Fibrogenesis & Tissue Repair
4
9
http://dx.doi.org/10.1186/1755-1536-4-9
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>BACKGROUND: The mechanism underlying the ability of fibroblasts to contract a collagen gel matrix is largely unknown. Fibroblasts from scarred (lesional) areas of patients with the fibrotic disease scleroderma show enhanced ability to contract collagen relative to healthy fibroblasts. Thrombospondin 1 (TSP1), an activator of latent transforming growth factor (TGF)β, is overexpressed by scleroderma fibroblasts. In this report we investigate whether activation of latent TGFβ by TSP1 plays a key role in matrix contraction by normal and scleroderma fibroblasts.</p>
<p>METHODS: We use the fibroblast populated collagen lattices (FPCL) model of matrix contraction to show that interfering with TSP1/TGFβ binding and knockdown of TSP1 expression suppressed the contractile ability of normal and scleroderma fibroblasts basally and in response to TGFβ. Previously, we have shown that ras/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) mediates matrix contraction basally and in response to TGFβ.</p>
<p>RESULTS: During mechanical stimulation in the FPCL system, using a multistation tensioning-culture force monitor (mst-CFM), TSP1 expression and p-ERK activation in fibroblasts are enhanced. Inhibiting TSP1 activity reduced the elevated activation of MEK/ERK and expression of key fibrogenic proteins. TSP1 also blocked platelet-derived growth factor (PDGF)-induced contractile activity and MEK/ERK activation.</p>
<p>CONCLUSIONS: TSP1 is a key mediator of matrix contraction of normal and systemic sclerosis fibroblasts, via MEK/ERK.</p>
https://ir.lib.uwo.ca/physpharmpub/39
oai:ir.lib.uwo.ca:physpharmpub-1039
2011-11-15T04:22:51Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
21054136
Analysis of Oocyte-Like Cells Differentiated from Porcine Fetal Skin-Derived Stem Cells
Dyce, Paul W.
Shen, Wei
Huynh, Evanna
Shao, Hua
Villagómez, Daniel A. F.
Kidder, Gerald M.
King, W. Allan
Li, Julang
Article
2011-05-01T07:00:00Z
Stem cell
Reproduction
Oocyte-Like cell
Stem Cells and Development
Stem Cells and Development
20
5
809
819
http://dx.doi.org/10.1089/scd.2010.0395
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>We previously reported the differentiation of cells derived from porcine female fetal skin into cells resembling germ cells and oocytes. A subpopulation of these cells expressed germ cell markers and formed aggregates resembling cumulus-oocyte complexes. Some of these aggregates extruded large oocyte-like cells (OLCs) that expressed markers consistent with those of oocytes. The objective of the current study was to further characterize OLCs differentiated from porcine skin-derived stem cells. Reverse transcriptase (RT)-polymerase chain reaction and Western blot revealed the expression of connexin37 and connexin43, both of which are characteristic of ovarian follicles. The expression of meiosis markers DMC1 and synaptonemal complex protein, but not STRA8 and REC8, was detected in the OLC cultures. Immunofluorescence with an antibody against synaptonemal complex protein on chromosome spreads revealed a very small subpopulation of stained OLCs that had a similar pattern to leptotene, zytotene, or pachytene nuclei during prophase I of meiosis. Sodium bisulfite sequencing of the differentially methylated region of H19 indicated that this region is almost completely demethylated in OLCs, similar to in vivo-derived oocytes. We also investigated the differentiation potential of male skin-derived stem cells in the same differentiation medium. Large cells with oocyte morphology were generated in the male stem cell differentiation cultures. These OLCs expressed oocyte genes such as octamer-binding transcription factor 4 (OCT4), growth differentiation factor-9b (GDF9B), deleted in azoospermia-like (DAZL), VASA, zona pellucida B (ZPB), and zona pellucida C (ZPC). It was concluded that skin-derived stem cells from both male and female porcine fetuses are capable of entering an oocyte differentiation pathway, but the culture system currently in place is inadequate to support the complete development of competent oocytes.</p>
<p>This is a copy of an article published in <em>Stem Cells and Development</em> © 2011 Mary Ann Liebert, Inc.; <em>Stem Cells and Development</em> is available online at: http://www.liebertonline.com.</p>
https://ir.lib.uwo.ca/physpharmpub/40
oai:ir.lib.uwo.ca:physpharmpub-1040
2011-05-04T00:16:43Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16730687
Antioxidant Effect of Zinc and Zinc-metallothionein in the Acute Cytotoxicity of Hydrogen Peroxide in Ehrlich Ascites Tumour Cells
Suntres, Zacharias E.
Lui, Edmund M. K.
Article
2006-07-25T07:00:00Z
Animals
Antioxidants
Calcium
Carcinoma
Ehrlich Tumor
Cell Line
Tumor
Cell Survival
Copper
Cytosol
Glutathione
Hydrogen Peroxide
Lipid Peroxidation
Metallothionein
Mice
Neoplasm Transplantation
Protein Binding
Time Factors
Tumor Cells
Zinc
Chemico-biological Interactions
Chemico-biological Interactions
162
1
11
23
http://dx.doi.org/10.1016/j.cbi.2006.04.007
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>This study was concerned with the role of zinc (Zn) and zinc-metallothionein (Zn-MT) in oxidative stress. Hydrogen peroxide-induced oxidative injury was examined in Ehrlich ascites tumour cells isolated from control host mice, mice pretreated with 10 mg/kg ZnSO4 (i.p.) to increase cellular Zn/Zn-MT levels, and mice exposed to Zn-deficient diet to reduce the cellular Zn/Zn-MT levels. The results of the present study showed that Ehrlich cells with seven-fold differences in Zn-MT concentrations could be obtained by manipulating the Zn status of host mice and that high Zn and Zn-MT levels can make Ehrlich cells more resistant to H2O2-induced oxidative injury (cell viability, lipid peroxidation, [Ca2+]i) while cells with reduced Zn/Zn-MT levels were more susceptible to this treatment. H2O2 treatment resulted in oxidation of MT thiolate groups and loss of its metal binding capacity with translocation of Zn released from oxidized MT to other cellular sites. Preincubation of Ehrlich cells with ZnSO4 in vitro also conferred some degree of resistance to H2O2 toxicity, suggesting the inherent antioxidative property of Zn ions. These data suggested that Zn-MT can be considered as an antioxidant by virtue of its thiolate groups and its Zn ions that are released in the presence of oxidative stress.</p>
https://ir.lib.uwo.ca/physpharmpub/41
oai:ir.lib.uwo.ca:physpharmpub-1041
2011-05-04T00:16:06Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16221516
Prooxidative Effect of Copper-metallothionein in the Acute Cytotoxicity of Hydrogen Peroxide in Ehrlich Ascites Tumour Cells
Suntres, Zacharias E.
Lui, Edmund M. K.
Article
2006-01-16T08:00:00Z
Animals
Calcium
Carcinoma
Ehrlich Tumor
Cell Survival
Copper
Copper Sulfate
Deferoxamine
Dose-Response Relationship
Drug
Glutathione Disulfide
Hydrogen Peroxide
Injections
Intraperitoneal
Iron
Lipid Peroxidation
Mannitol
Metallothionein
Mice
Oxidative Stress
Penicillamine
Pinocytosis
Time Factors
Tumor Cells
Zinc
Toxicology
Toxicology
217
2-3
155
168
http://dx.doi.org/10.1016/j.tox.2005.09.004
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>This study was concerned with the role of copper (Cu) and Cu-metallothionein (Cu-MT) in oxidative stress. Hydrogen peroxide (H(2)O(2))-induced oxidative injury was examined in Ehrlich ascites tumour cells isolated from host mice pretreated with 0, 1 or 2mg of CuSO(4) (ip) 24h earlier. Control Ehrlich cells contained low levels of Cu and Cu treatment produced dose-related increases in cellular Cu and Cu-MT levels and corresponding increases in sensitivity to oxidative toxicity of H(2)O(2) (LC(50), cell blebbing, lipid peroxidation, GSH depletion, and increase in intracellular free [Ca(2+)](i)). Hydrogen peroxide treatment also resulted in the oxidation of MT thiolates, reduction in the binding of Cu to MT resulting in translocation of Cu to other subcellular sites. d-penicillamine, a Cu-chelating agent, obliterated the sensitization effect of Cu-pretreatment and reduced the redistribution of MT-bound Cu, suggesting the participation of Cu ions derived from MT in promoting oxidant stress. Additional experiments with desferoxamine and mannitol have revealed the involvement of a Cu-dependent Fenton reaction in the mediation of the prooxidative effect of Cu-MT. These data suggest that cells with high levels of Cu-MT may be particularly susceptible to oxidative stress.</p>
https://ir.lib.uwo.ca/physpharmpub/42
oai:ir.lib.uwo.ca:physpharmpub-1043
2011-05-24T00:13:05Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
20959150
The Increased In Vitro Osteoclastogenesis in Patients with Rheumatoid Arthritis Is due to Increased Percentage of Precursors and Decreased Apoptosis — The In Vitro Osteoclast Differentiation in Arthritis (IODA) Study
Durand, M.
Boire, G.
Komarova, S. V.
Dixon, S. J.
Sims, S. M.
Harrison, R. E.
Nabavi, N.
Maria, O.
Manolson, M. F.
Mizianty, M.
Kurgan, L.
de Brum-Fernandes, A. J.
Article
2011-03-01T08:00:00Z
Rheumatoid arthritis
Bone
Osteoclast
Apoptosis
CD14+
Osteoclastogenesis
Biomarker
Diagnostic model
Bone
Bone
48
3
588
596
http://dx.doi.org/10.1016/j.bone.2010.10.167
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Increases in local and systemic bone resorption are hallmarks of rheumatoid arthritis (RA). Osteoclasts are implicated in these processes and their enhanced differentiation may contribute to bone destruction. We observed that in vitro osteoclastogenesis varies among healthy individuals and hypothesized that increased osteoclastogenesis could be a marker for the presence of RA. Our objective in the present study was to determine if in vitro osteoclastogenesis from peripheral blood mononuclear cells (PBMCs) was different in patients with RA compared to healthy controls and osteoarthritis (OA) patients. Expression of CD14 in PBMCs was quantified and PBMCs were incubated for 21 days in the presence of the osteoclastogenic cytokines M-CSF and RANKL. Differentiation on cortical bone slices permitted the analysis of bone resorption while apoptotic potential was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. In vitro osteoclastogenesis was higher in PBMCs from RA patients compared to controls, and a similar increase was observed in the percentage of osteoclast precursors in RA patients. Osteoclasts from RA patients showed lower apoptotic rates than osteoclasts from healthy controls. No difference was observed in bone resorption activity between RA patients and controls. Interestingly, the difference in osteoclast number and apoptosis rate allowed the implementation of an algorithm capable of distinguishing patients with RA from controls. In conclusion, our study shows that osteoclast differentiation from PBMCs is enhanced in patients with RA, and this difference can be explained by both a higher percentage of osteoclast precursors in the blood and by the reduced apoptotic potential of mature osteoclasts.</p>
https://ir.lib.uwo.ca/physpharmpub/44
oai:ir.lib.uwo.ca:physpharmpub-1044
2011-05-24T00:52:10Z
publication:physics
publication:physpharmpub
publication:pmid
publication:faculties
publication:physicspub
publication:physpharm
20615020
Optical Waveguides Formed by Silver Ion Exchange in Schott SG11 Glass for Waveguide Evanescent Field Fluorescence Microscopy: Evanescent Images of HEK293 Cells
Hassanzadeh, Abdollah
Nitsche, Michael
Armstrong, Souzan
Dixon, S. Jeffrey
Nabavi, Noushin
Harrison, Rene
Langbein, Uwe
Mittler, Silvia
Article
2010-05-01T07:00:00Z
Algorithms
Cell Line
Glass
Humans
Ion Exchange
Microscopy
Fluorescence
Refractometry
Silver
Spectrometry
Fluorescence
Temperature
Journal of Biomedical Optics
Journal of Biomedical Optics
15
3
036018
036018
http://dx.doi.org/10.1117/1.3443796
Medical Physiology
Pharmacy and Pharmaceutical Sciences
Physics
<p>Planar glass waveguides with a specific number of modes were fabricated by Ag(+)-Na(+) exchange in Schott SG11 glass. The effective refractive indices were determined using m-line spectroscopy in both s- and p-polarization. By using the reversed Wentzel-Kramers-Brillouin approximation, the index profiles were described by a nonlinear diffusion equation. The diffusion coefficients for Ag(+) were established, as well as the penetration depth of the evanescent field in an aqueous environment for the different modes. The integrals of \E\(2) fields for the evanescent-guided fields were investigated. These are important when evanescent fields are used for illumination in interface microscopy, an alternative method to total internal reflection fluorescence (TIRF) microscopy. The photoluminescent behavior of the waveguides was investigated as a function of ion exchange time and excitation wavelengths. Comparable images were obtained of fluorescently labeled HEK293 cells using TIRF microscopy and waveguide evanescent field fluorescence microscopy. Imaging was performed using HEK293 cells, delivering similar images and information.</p>
https://ir.lib.uwo.ca/physpharmpub/45
oai:ir.lib.uwo.ca:physpharmpub-1050
2011-05-24T01:25:38Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
18404419
Activation of Transcription Factors by Extracellular Nucleotides in Immune and Related Cell Types
Armstrong, Souzan
Korcok, Jasminka
Sims, Stephen M.
Dixon, S. Jeffrey
Article
2007-03-01T08:00:00Z
Transcription factors
Extracellular nucleotides
Immune cell
Purinergic Signal
Purinergic Signal
3
1-2
59
69
http://dx.doi.org/10.1007/s11302-006-9037-8
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Extracellular nucleotides, acting through P2 receptors, can regulate gene expression via intracellular signaling pathways that control the activity of transcription factors. Relatively little is known about the activation of transcription factors by nucleotides in immune cells. The NF-kappaB family of transcription factors is critical for many immune and inflammatory responses. Nucleotides released from damaged or stressed cells can act alone through certain P2 receptors to alter NF-kappaB activity or they can enhance responses induced by pathogen-associated molecules such as LPS. Nucleotides have also been shown to regulate the activity of other transcription factors (AP-1, NFAT, CREB and STAT) in immune and related cell types. Here, we provide an overview of transcription factors shown to be activated by nucleotides in immune cells, and describe what is known about their mechanisms of activation and potential functions. Furthermore, we propose areas for future work in this new and expanding field.</p>
https://ir.lib.uwo.ca/physpharmpub/50
oai:ir.lib.uwo.ca:physpharmpub-1046
2011-05-24T00:49:51Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
20551326
Lysophosphatidic Acid Signals through Multiple Receptors in Osteoclasts to Elevate Cytosolic Calcium Concentration, Evoke Retraction, and Promote Cell Survival
Lapierre, Danielle M.
Tanabe, Natsuko
Pereverzev, Alexey
Spencer, Martha
Shugg, Ryan P. P.
Dixon, S. Jeffrey
Sims, Stephen M.
Article
2010-08-13T07:00:00Z
Bone
Calcium
Cell Death
Cell-Cell Interaction
G Protein-coupled Receptors (GPCR)
Nuclear Translocation
Osteoclast Acidification
NFATc1
Lysophosphatidic Acid
The Journal of Biological Chemistry
The Journal of Biological Chemistry
285
33
25792
25801
http://dx.doi.org/10.1074/jbc.M110.109322
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Lysophosphatidic acid (LPA) is a bioactive phospholipid whose functions are mediated by multiple G protein-coupled receptors. We have shown that osteoblasts produce LPA, raising the possibility that it mediates intercellular signaling among osteoblasts and osteoclasts. Here we investigated the expression, signaling and function of LPA receptors in osteoclasts. Focal application of LPA elicited transient increases in cytosolic calcium concentration ([Ca(2+)](i)), with 50% of osteoclasts responding at approximately 400 nm LPA. LPA-induced elevation of [Ca(2+)](i) was blocked by pertussis toxin or the LPA(1/3) receptor antagonist VPC-32183. LPA caused sustained retraction of osteoclast lamellipodia and disrupted peripheral actin belts. Retraction was insensitive to VPC-32183 or pertussis toxin, indicating involvement of a distinct signaling pathway. In this regard, inhibition of Rho-associated kinase stimulated respreading after LPA-induced retraction. Real-time reverse transcription-PCR revealed transcripts encoding LPA(1) and to a lesser extent LPA(2), LPA(4), and LPA(5) receptor subtypes. LPA induced nuclear translocation of NFATc1 and enhanced osteoclast survival, effects that were blocked by VPC-32183 or by a specific peptide inhibitor of NFAT activation. LPA slightly reduced the resorptive activity of osteoclasts in vitro. Thus, LPA binds to at least two receptor subtypes on osteoclasts: LPA(1), which couples through G(i/o) to elevate [Ca(2+)](i), activate NFATc1, and promote survival, and a second receptor that likely couples through G(12/13) and Rho to evoke and maintain retraction through reorganization of the actin cytoskeleton. These findings reveal a signaling axis in bone through which LPA, produced by osteoblasts, acts on multiple receptor subtypes to induce pleiotropic effects on osteoclast activity and function.</p>
<dl><dt>PMCID: PMC2919141 [Available on 2011/8/13]</dt></dl>
https://ir.lib.uwo.ca/physpharmpub/46
oai:ir.lib.uwo.ca:physpharmpub-1052
2011-05-24T01:40:34Z
publication:anatomy
publication:physpharmpub
publication:pmid
publication:faculties
publication:anatomypub
publication:physpharm
17620283
P2Y Nucleotide Receptor Signaling through MAPK/ERK Is Regulated by Extracellular Matrix: Involvement of β3 Integrins
Kudirka, Julie C.
Panupinthu, Nattapon
Tesseyman, Mark A.
Dixon, S. Jeffrey
Bernier, Suzanne M.
Article
2007-10-01T07:00:00Z
Animals
Calcium
Cultured Cells
Chondrocytes
Extracellular Matrix
Integrin beta3
MAP Kinase Signaling System
Nucleotides
Oligopeptides
Phospholipase D
Phosphorylation
Protein Kinase C
RNA
Messenger
Rats
Receptors
Purinergic P2
Signal Transduction
Journal of Cellular Physiology
Journal of Cellular Physiology
213
1
54
64
http://dx.doi.org/10.1002/jcp.21087
Medical Cell Biology
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Extracellular matrix influences cell behavior through receptors such as integrins and through transmission of mechanical forces. Nucleotides are released in response to mechanical stimuli and bind to P2 nucleotide receptors. As chondrocytes are subjected to frequent mechanical stimulation within a rich extracellular matrix, they are an excellent model for studying integration of signals induced by matrix and nucleotides. We investigated signaling of G protein-coupled P2Y receptors to MAPK/ERK and how this is influenced by matrix. Rat articular chondrocytes expressed transcripts for P2Y1, P2Y2, P2Y4, and P2Y6 receptors and responded to extracellular nucleotides by transient elevation of cytosolic calcium and MAPK/ERK phosphorylation. ERK1/2 activation was suppressed by the protein kinase C (PKC) inhibitors bisindolylmaleimide I and rottlerin, and by the phospholipase D inhibitor 1-butanol. Thus, nucleotides stimulate P2Y receptors to activate ERK1/2 through a mechanism dependent on PKC and phospholipase D. We next examined the involvement of integrins. Both an RGD-containing pentapeptide and a beta3 integrin blocking antibody, but not a beta1 integrin blocking antibody, abolished nucleotide-induced ERK1/2 phosphorylation. Moreover, chondrocytes adhering to fibronectin (which binds to beta1 and beta3 containing integrins in an RGD-dependent manner) displayed prolonged ERK1/2 signaling compared to cells grown on type I or II collagen (which bind to beta1-containing integrins in an RGD-independent manner). In conclusion, P2Y receptor signaling through ERK1/2 is gated selectively by matrix proteins. Thus, nucleotides released in response to mechanical stimulation will have differing effects on cell function due to changes in the composition of the extracellular matrix during development and disease.</p>
https://ir.lib.uwo.ca/physpharmpub/52
oai:ir.lib.uwo.ca:physpharmpub-1047
2011-05-24T01:00:12Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
19224395
Expression, Signaling, and Function of P2X7 Receptors in Bone
Grol, Matthew W.
Panupinthu, Nattapon
Korcok, Jasminka
Sims, Stephen M.
Dixon, S. Jeffrey
Article
2009-06-01T07:00:00Z
Expression
Signaling
Function
P2X7 receptors
Bone
Purinergic Signal
Purinergic Signal
5
2
205
221
http://dx.doi.org/10.1007/s11302-009-9139-1
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Nucleotides released from cells in response to mechanical stimulation or injury may serve as paracrine regulators of bone cell function. Extracellular nucleotides bind to multiple subtypes of P2 receptors on osteoblasts (the cells responsible for bone formation) and osteoclasts (cells with the unique ability to resorb mineralized tissues). Both cell lineages express the P2X7 receptor subtype. The skeletal phenotype of mice with targeted disruption of P2rx7 points to interesting roles for this receptor in the regulation of bone formation and resorption, as well as the response of the skeleton to mechanical stimulation. This paper reviews recent work on the expression of P2X7 receptors in bone, their associated signal transduction mechanisms and roles in regulating bone formation and resorption. Areas for future research in this field are also discussed.</p>
https://ir.lib.uwo.ca/physpharmpub/47
oai:ir.lib.uwo.ca:physpharmpub-1048
2011-05-24T01:07:55Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
19066285
Activation of P2X7 Receptors Causes Isoform-specific Translocation of Protein Kinase C in Osteoclasts
Armstrong, Souzan
Pereverzev, Alexey
Dixon, S. Jeffrey
Sims, Stephen M.
Article
2009-01-01T08:00:00Z
Adenosine Triphosphate
Animals
Calcium
Cell Line
Cell Membrane
Enzyme Activation
Isoenzymes
Mice
Osteoclasts
Protein Kinase C
Receptors
Purinergic P2
Receptors
Purinergic P2X7
Recombinant Fusion Proteins
Journal of Cell Science
Journal of Cell Science
122
Pt 1
136
144
http://dx.doi.org/10.1242/jcs.031534
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Nucleotides, released in response to mechanical or inflammatory stimuli, signal through P2 nucleotide receptors in many cell types. Osteoclasts express P2X7 receptors (encoded by P2rx7) - Ca(2+)-permeable channels that are activated by high concentrations of extracellular ATP. Genetic disruption of P2rx7 leads to increased resorption and reduced skeletal response to mechanical stimuli. To investigate whether P2X7 receptors couple to activation of protein kinase C (PKC), RAW 264.7 cells were differentiated into multinucleated osteoclast-like cells and live-cell confocal imaging was used to localize enhanced green fluorescent protein (EGFP)-tagged PKC. Benzoylbenzoyl-ATP (BzATP; a P2X7 agonist) induced transient translocation of PKCalpha to the basolateral membrane. UTP or ATP (10 microM), which activate P2 receptors other than P2X7, failed to induce translocation. Moreover, BzATP failed to induce PKC translocation in osteoclasts derived from the bone marrow of P2rx7(-/-) mice, demonstrating specificity for P2X7. BzATP induced a transient rise of cytosolic Ca(2+), and removal of extracellular Ca(2+) abolished the translocation of PKCalpha that was induced by BzATP (but not by phorbol ester). We examined the isoform specificity of this response, and observed translocation of the Ca(2+)-dependent isoforms PKCalpha and PKCbetaI, but not the Ca(2+)-independent isoform PKCdelta. Thus, activation of P2X7 receptors specifically induces Ca(2+)-dependent translocation of PKC to the basolateral membrane domain of osteoclasts, an aspect of spatiotemporal signaling not previously recognized.</p>
https://ir.lib.uwo.ca/physpharmpub/48
oai:ir.lib.uwo.ca:physpharmpub-1049
2011-05-24T01:15:21Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
18519738
P2X7 Receptors on Osteoblasts Couple to Production of Lysophosphatidic Acid: A Signaling Axis Promoting Osteogenesis
Panupinthu, Nattapon
Rogers, Joseph T.
Zhao, Lin
Solano-Flores, Luis Pastor
Possmayer, Fred
Sims, Stephen M.
Dixon, S. Jeffrey
Article
2008-06-02T07:00:00Z
Animals
Chondrocytes
Cyclooxygenase Inhibitors
Dinoprostone
Gene Expression Regulation
Lipids
Lysophospholipids
Transgenic Mice
Biological Models
Osteoblasts
Osteogenesis
Rats
Receptors
Purinergic P2
Receptors
Purinergic P2X7
Signal Transduction
Skull
The Journal of Cell Biology
The Journal of Cell Biology
181
5
859
871
http://dx.doi.org/10.1083/jcb.200708037
Medical Biochemistry
Medical Physiology
Obstetrics and Gynecology
Pharmacy and Pharmaceutical Sciences
<p>Nucleotides are released from cells in response to mechanical stimuli and signal in an autocrine/paracrine manner through cell surface P2 receptors. P2rx7-/- mice exhibit diminished appositional growth of long bones and impaired responses to mechanical loading. We find that calvarial sutures are wider in P2rx7-/- mice. Functional P2X7 receptors are expressed on osteoblasts in situ and in vitro. Activation of P2X7 receptors by exogenous nucleotides stimulates expression of osteoblast markers and enhances mineralization in cultures of rat calvarial cells. Moreover, osteogenesis is suppressed in calvarial cell cultures from P2rx7-/- mice compared with the wild type. P2X7 receptors couple to production of the potent lipid mediators lysophosphatidic acid (LPA) and prostaglandin E2. Either an LPA receptor antagonist or cyclooxygenase (COX) inhibitors abolish the stimulatory effects of P2X7 receptor activation on osteogenesis. We conclude that P2X7 receptors enhance osteoblast function through a cell-autonomous mechanism. Furthermore, a novel signaling axis links P2X7 receptors to production of LPA and COX metabolites, which in turn stimulate osteogenesis.</p>
https://ir.lib.uwo.ca/physpharmpub/49
oai:ir.lib.uwo.ca:physpharmpub-1051
2011-05-24T01:32:17Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
17964236
Extracellular Acidification Enhances Osteoclast Survival through an NFAT-independent, Protein Kinase C-dependent Pathway
Pereverzev, Alexey
Komarova, Svetlana V.
Korcok, Jasminka
Armstrong, Souzan
Tremblay, Gilles B.
Dixon, S. Jeffrey
Sims, Stephen M.
Article
2008-01-01T08:00:00Z
Acidosis
Apoptosis
Bone resorption
Cytosolic calcium
Ovarian cancer G protein-coupled receptor 1 (OGR1)
Bone
Bone
42
1
150
161
http://dx.doi.org/10.1016/j.bone.2007.08.044
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Systemic acidosis has detrimental effects on the skeleton and local acidosis is associated with bone destruction in inflammatory and neoplastic diseases. However, the mechanisms by which acidosis enhances osteoclastic bone resorption are poorly understood. Our aim was to examine the effects of acid on osteoclast survival and the involvement of cytosolic Ca(2+) in mediating these effects. Osteoclasts were isolated from long bones of newborn rats, and multinucleated osteoclast-like cells were generated from RAW 264.7 cells. Cytosolic free Ca(2+) concentration ([Ca(2+)](i)) was monitored using fura-2. Survival of rat osteoclasts over a period of 18 h was significantly enhanced by acidification of the medium from 40+/-10% at pH 7.6 to 83+/-4% at pH 7.0. Consistent with its effects on survival, acidosis suppressed osteoclast apoptosis at 6 h. We examined the possible involvement of the proton-sensing receptor ovarian cancer G protein-coupled receptor 1 (OGR1) in mediating the effects of acid. Acid-induced rise of [Ca(2+)](i) was inhibited by the OGR1 antagonist Cu(2+) and was suppressed in osteoclast-like cells in which OGR1 transcripts were depleted using RNA interference. These findings support an essential role for OGR1 in acid-induced Ca(2+) signaling in osteoclasts. Addition of Cu(2+) or chelation of cytosolic Ca(2+) with BAPTA abolished the ability of acidification to enhance osteoclast survival. Inhibition of NFAT activation with the cell-permeable peptide 11R-VIVIT did not alter the ability of acid to promote survival; however, it suppressed the increase in survival induced by RANKL. In contrast, inhibition of protein kinase C (PKC) blocked the effect of acid on osteoclast survival. Thus, this study reveals that extracellular acidification enhances osteoclast survival through an NFAT-independent, PKC-dependent pathway. Increased osteoclast survival may contribute to bone loss in systemic and local acidosis.</p>
https://ir.lib.uwo.ca/physpharmpub/51
oai:ir.lib.uwo.ca:physpharmpub-1056
2011-05-24T02:31:34Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16950788
Up-regulation of Endogenous RGS2 Mediates Cross-desensitization between Gs and Gq Signaling in Osteoblasts
Roy, Anju Anne
Nunn, Caroline
Ming, Hong
Zou, Min-Xu
Penninger, Josef
Kirshenbaum, Lorrie A.
Dixon, S. Jeffrey
Chidiac, Peter
Article
2006-10-27T07:00:00Z
Adenosine Triphosphate
Adenoviridae
Animals
Cell Culture Techniques
Cultured Cells
Indirect Fluorescent Antibody Technique
Forskolin
GTP-Binding Protein alpha Subunits
Gq-G11
GTP-Binding Protein alpha Subunits
Gs
Mice
Inbred C57BL
Confocal Microscopy
Osteoblasts
Parathyroid Hormone
Peptide Fragments
RGS Proteins
Signal Transduction
Skull
Tetradecanoylphorbol Acetate
Up-Regulation
The Journal of Biological Chemistry
The Journal of Biological Chemistry
281
43
32684
32693
http://dx.doi.org/10.1074/jbc.M604416200
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Regulator of G protein signaling (RGS) proteins limit G protein signals. In this study, we investigated the role of RGS2 in the control of G protein signaling cascades in osteoblasts, the cells responsible for bone formation. Expression of RGS2 was up-regulated in primary cultures of mouse calvarial osteoblasts by parathyroid hormone-related peptide (PTHrP)-(1-34), which stimulates G(s) signaling. RGS2 was also up-regulated by extracellular ATP, which selectively activates G(q), as well as by forskolin and phorbol myristate acetate, which activate targets downstream of G(s) and G(q), respectively. To assess the role of endogenous RGS2, we characterized G(s) and G(q) signaling in osteoblasts derived from wild type and rgs2(-/-) mice. Under control conditions, nucleotide-stimulated calcium release, endothelin-stimulated accumulation of inositol phosphates, and PTHrP-stimulated cAMP accumulation were equivalent in osteoblasts isolated from wild type and rgs2(-/-) mice. Thus, basal levels of endogenous RGS2 do not appear to regulate G(s) or G(q) signaling in osteoblasts. Interestingly, forskolin treatment of wild type but not rgs2(-/-) osteoblasts suppressed both endothelin-stimulated accumulation of inositol phosphates and nucleotide-stimulated calcium release, indicating that up-regulation of RGS2 by G(s) signaling desensitizes G(q) signals. Furthermore, pretreatment with ATP suppressed PTHrP-dependent cAMP accumulation in wild type but not rgs2(-/-) osteoblasts, implying that up-regulation of RGS2 by G(q) signaling desensitizes G(s) signals. Our findings demonstrate that endogenously expressed RGS2 can limit G(s) signaling. Moreover, up-regulation of RGS2 contributes to cross-desensitization of G(s)- and G(q)-coupled signals.</p>
https://ir.lib.uwo.ca/physpharmpub/56
oai:ir.lib.uwo.ca:physpharmpub-1058
2011-05-24T00:00:28Z
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
16572175
Regulation of Cancer Cell Migration and Bone Metastasis by RANKL
Jones, D. Holstead
Nakashima, Tomoki
Sanchez, Otto H.
Kozieradzki, Ivona
Komarova, Svetlana V.
Sarosi, Ildiko
Morony, Sean
Rubin, Evelyn
Sarao, Renu
Hojilla, Carlo V.
Komnenovic, Vukoslav
Kong, Young-Yun
Schreiber, Martin
Dixon, S. Jeffrey
Sims, Stephen M.
Khokha, Rama
Wada, Teiji
Penninger, Josef M.
Letter to the Editor
2006-03-30T08:00:00Z
Animals
Bone Neoplasms
Breast Neoplasms
Carrier Proteins
Cell Death
Cell Differentiation
Cell Line
Tumor
Cell Movement
Cell Proliferation
Epithelial Cells
Humans
Melanoma
Membrane Glycoproteins
Mice
Neoplasm Metastasis
Organ Specificity
Paralysis
RANK Ligand
Receptor Activator of Nuclear Factor-kappa B
Signal Transduction
Nature
Nature
440
7084
692
696
http://dx.doi.org/10.1038/nature04524
Medical Physiology
Pharmacy and Pharmaceutical Sciences
<p>Bone metastases are a frequent complication of many cancers that result in severe disease burden and pain. Since the late nineteenth century, it has been thought that the microenvironment of the local host tissue actively participates in the propensity of certain cancers to metastasize to specific organs, and that bone provides an especially fertile 'soil'. In the case of breast cancers, the local chemokine milieu is now emerging as an explanation for why these tumours preferentially metastasize to certain organs. However, as the inhibition of chemokine receptors in vivo only partially blocks metastatic behaviour, other factors must exist that regulate the preferential metastasis of breast cancer cells. Here we show that the cytokine RANKL (receptor activator of NF-kappaB ligand) triggers migration of human epithelial cancer cells and melanoma cells that express the receptor RANK. RANK is expressed on cancer cell lines and breast cancer cells in patients. In a mouse model of melanoma metastasis, in vivo neutralization of RANKL by osteoprotegerin results in complete protection from paralysis and a marked reduction in tumour burden in bones but not in other organs. Our data show that local differentiation factors such as RANKL have an important role in cell migration and the tissue-specific metastatic behaviour of cancer cells.</p>
https://ir.lib.uwo.ca/physpharmpub/43
oai:ir.lib.uwo.ca:physpharmpub-1054
2011-05-24T01:58:02Z
publication:physpharmpub
publication:obsgyn
publication:obsgynpub
publication:pmid
publication:faculties
publication:physpharm
publication:biochempub
publication:biochem
17135244
P2X7 Nucleotide Receptors Mediate Blebbing in Osteoblasts through a Pathway Involving Lysophosphatidic Acid
Panupinthu, Nattapon
Zhao, Lin
Possmayer, Fred
Ke, Hua Z.
Sims, Stephen M.
Dixon, S. Jeffrey
Article
2007-02-02T08:00:00Z
Adenosine Triphosphate
Animals
Newborn Animals
Genetic Crosses
Intracellular Signaling Peptides and Proteins
Lysophospholipids
Mice
Mice
Inbred C57BL
Mice
Inbred DBA
Osteoblasts
Phospholipases
Protein-Serine-Threonine Kinases
Rats
Receptors
Purinergic P2
Receptors
Purinergic P2X7
rho-Associated Kinases
The Journal of Biological Chemistry
The Journal of Biological Chemistry
282
5
3403
3412
http://dx.doi.org/10.1074/jbc.M605620200
Medical Biochemistry
Medical Physiology
Obstetrics and Gynecology
Pharmacy and Pharmaceutical Sciences
<p>Extracellular nucleotides, released in response to mechanical or inflammatory stimuli, signal through P2 receptors in many cell types, including osteoblasts. P2X7 receptors are ATP-gated cation channels that can induce formation of large membrane pores. Disruption of the gene encoding the P2X7 receptor leads to decreased periosteal bone formation and insensitivity of the skeleton to mechanical stimulation. Our purpose was to investigate signaling pathways coupled to P2X7 activation in osteoblasts. Live cell imaging showed that ATP or 2 ',3 '-O-(4-benzoylbenzoyl)-ATP (BzATP), but not UTP, UDP, or 2-methylthio-ADP, induced dynamic membrane blebbing in calvarial osteoblasts. Blebbing was observed in calvarial cells from wildtype but not P2X7 knock-out mice. P2X7 receptors coupled to activation of phospholipase D and A2, inhibition of which suppressed BzATP-induced blebbing. Activation of these phospholipases leads to production of lysophosphatidic acid (LPA). LPA caused dynamic blebbing in osteoblasts from both wild-type and P2X7 knock-out mice, similar to that induced by BzATP in wildtype cells. However, LPA-induced blebbing was more rapid in onset and was not affected by inhibition of phospholipase D or A2. Blockade or desensitization of LPA receptors suppressed blebbing in response to LPA and BzATP, without affecting P2X7-stimulated pore formation. Thus, LPA functions downstream of P2X7 receptors to induce membrane blebbing. Furthermore, inhibition of Rho-associated kinase abolished blebbing induced by both BzATP and LPA. In summary, we propose a novel signaling axis that links P2X7 receptors through phospholipases to production of LPA and activation of Rho-associated kinase. This pathway may contribute to P2X7-stimulated osteogenesis during skeletal development and mechanotransduction.</p>
https://ir.lib.uwo.ca/physpharmpub/54
oai:ir.lib.uwo.ca:physpharmpub-1057
2011-05-24T02:37:50Z
publication:biophysicspub
publication:physpharmpub
publication:pmid
publication:faculties
publication:physpharm
publication:biophysics
publication:biochempub
publication:biochem
16715520
Real-time Measurement of Cytosolic Free Calcium Concentration in Jurkat Cells during ELF Magnetic Field Exposure and Evaluation of the Role of Cell Cycle
McCreary, Cheryl R.
Dixon, S. Jeffrey
Fraher, Laurence J.
Carson, Jeffrey J. L.
Prato, Frank S.
Article
2006-07-01T07:00:00Z
Calcium
Cell Cycle
Cytosol
DNA
Homeostasis
Jurkat Cells
Radiometry
Spectrometry
Fluorescence
Bioelectromagnetics
Bioelectromagnetics
27
5
354
364
http://dx.doi.org/10.1002/bem.20248
Medical Biophysics
Medical Physiology
<p>Extremely low frequency magnetic fields (ELF MF) have been reported to alter a number of cell signaling pathways, including those involved in proliferation, differentiation and apoptosis where cytosolic free calcium ([Ca(2+)](c)) plays an important role. To better understand the biological conditions under which ELF MF exposure might alter [Ca(2+)](c), we measured [Ca(2+)](c) by ratiometric fluorescence spectrophotometry during exposure to ELF MF in Jurkat E6.1 cells synchronized to different phases of the cell cycle. Suspensions of cells were exposed either to a near zero MF (Null) or a 60 Hz, 100 microT sinusoidal MF superimposed upon a collinear 78.1 microT static MF (AC + DC). An initial series of experiments indicated that the maximum increase in [Ca(2+)](c) above baseline after stimulation with anti-CD3 was significantly higher in samples exposed to AC + DC (n = 30) compared to Null (n = 30) with the largest difference in G2-M enriched samples. However, in a second study with G2-M enriched cells, samples treated with AC + DC (n = 17) were not statistically different from Null-treated samples (n = 27). Detailed analysis revealed that the dynamics in [Ca(2+)](c) before and after stimulation with anti-CD3 were dissimilar between Null samples from each study. From the results, we concluded (i) that the ELF MF increased [Ca(2+)](c) during an antibody-induced signaling event, (ii) that the ELF MF effect did not depend to a large degree on cell cycle, and (iii) that a field-related change in [Ca(2+)](c) signaling appeared to correlate with features in the [Ca(2+)](c) dynamics. Future work could evaluate [Ca(2+)](c) dynamics in relation to the phase of the cell cycle and inter-study variation, which may reveal factors important for the observation of real-time effects of ELF MF on [Ca(2+)](c).</p>
https://ir.lib.uwo.ca/physpharmpub/57
704024/qualified-dublin-core/100//