Date of Award
2010
Degree Type
Thesis
Degree Name
Master of Science
Program
Physiology
Supervisor
Dr. Jane Rylett
Second Advisor
Dr. Marco Prado
Third Advisor
Dr. Frank Beier
Abstract
The 82-kDa isoform of choline acetyltransferase (82-ChAT) is unique to primates and is found in cholinergic cell nuclei. The functional significance of this protein is not well understood. Previous studies showed that nuclear 82-ChAT levels decrease with advancing age, and this is accelerated in Alzheimer’s disease (AD). The present studies examined the effect of 82-ChAT on amyloid precursor protein (APP) metabolism and amyloid-P (Ap) production. Levels of enzymes involved in processing of APP were examined in human SH-SY5Y neuroblastoma cells and in primary neuronal cultures prepared from cerebral cortex of embryonic APP/PS1 double transgenic mice that serve as a model of AD. A significant amount of APi^2 was released into cell culture media from neurons cultured from transgenic mice for 8 DIV, and this was associated with an elevation of total APP levels rather than changes in levels of APP processing enzymes. Upon expression of 82-ChAT, a 20% reduction in AP-m2 release was found when compared to GFP-expressing control neurons. This was associated with a significant reduction in the protein but not mRNA of the p-secretase BACE1, indicating that 82-ChAT may alter proteins involved in post-translational modification and regulation of BACE1. These studies have important implications for AD pathology and broaden our understanding of the function of 82-ChAT proteins.
Recommended Citation
Abji, Fatima S., "Modulation of APP Processing and Amyloid-P Levels by Human 82-kDa Choline Acetyltransferase" (2010). Digitized Theses. 4117.
https://ir.lib.uwo.ca/digitizedtheses/4117