Fig. 7.
Cardiomyocyte deletion of Ogt suppresses GATA-4 expression during pressure overload. Markers of differentiation and lineage were detected via RT-PCR in WT and i-cmOgt−/− groups following 2 and 4 weeks of TAC. Gene expression of adult cardiomyocyte markers (Myh6, Myh7) remained unchanged (a, b) in both 2- and 4-week TAC groups. Markers of lineage commitment (Mef2c, Nxk2-5, and Gata4) remained unchanged at 2-week post-TAC (a). At 4-week post-TAC, Gata4 mRNA expression was significantly down-regulated in the i-cmOgt−/− group (b). GATA-4 protein expression was assessed at both 2 and 4 weeks (c, d). GATA-4 protein was significantly depressed at both 2 and 4 weeks in the i-cmOgt−/− groups. In additional experiments, NRCMs were transduced with adenovirus to overexpress OGA (which decreases O-GlcNAc levels). OGA overexpression was verified by qRT-PCR (e) and western blotting (f). In these same NRCMs, Gata4 mRNA (g) and GATA-4 protein expression (h) were measured. *p < 0.05 vs. WT TAC