The role of DLC1β in attenuating cardiac ischemia-reperfusion injury during heart transplantation
Abstract
Cardiac ischemia-reperfusion injury (IRI) occurs intra-operatively during heart transplantation (HTx), underpinning graft survival. Past research implicated the PI3K/Akt1 & RhoA/ROCK pathways in IRI. Rho-GTPase activity/Akt regulates Deleted-in-liver-cancer 1 protein’s beta-isoform (DLC1β). Therefore, we hypothesized that DLC1β overexpression (OE) had anti-apoptotic effects. In vitro, HL-1 cells (mouse cardiomyocytes) received chamber hypoxia-oxygenation reperfusion (H/R) for 24H4R with/without DLC1β plasmid, before collection for protein/mRNA analyses. DLC1β-OE resulted in downregulated pro-apoptotic mRNA expression (Bax/Cycs/Casp3), upregulated protective mRNA targets (BCl2/Akt1) and less late/early apoptosis via flow cytometry. Results were confirmed via H9C2 (rat cardiomyocyte) cell lines. In vivo, C57/BL6 mice received heterotopic HTx with/without DLC1β-OE plasmid tail-vein injections. Grafts were analyzed POD1/7 via mRNA/protein/histopathology. Treatment with DLC1β-OE reduced IRI as evidenced by decreased cumulative injury via histopathology. In summary, future translational applications are of interest as DLC1β-OE demonstrated novel anti-apoptotic effects conferred via RT-qPCR in vitro; moreover, in vivo grafts demonstrated reduced neutrophilic infiltrate/fibrosis/overall injury.