FIGURE 9.

Bcl2 mediated the anti-autophagic effect of GATA4. A, increased GATA4 enhanced the interaction between Bcl2 and Beclin 1. Cardiomyocytes were infected with Adβgal or AdG4, and protein samples were prepared 24 h later. 100 μg of protein was used for co-IP with Bcl2 antibodies (left panel), and 10 μg of protein was used as the input control (right panel). IB, immunoblotting. B, two different siRNAs against rat Bcl2 mRNA sequence (siBcl2) were transfected into cardiomyocytes. Both siRNAs were able to knock down Bcl2 protein levels in a dose-dependent manner, with siBcl2 #2 having a higher efficiency. C, cardiomyocytes were infected with Adβgal or AdG4 and then followed by siRNA transfection with a Silencer Negative Control siRNA (siCon) or a mixture of the two siBcl2 (#1 and #2 each at 50 nm). Knocking down Bcl2 markedly attenuated the ability of GATA4 to inhibit autophagy as shown by the difference in protein levels of LC3-II in the absence and presence of BFA. D, cardiomyocytes were infected with AdshG4 or AdshCon for 48 h and then infected with AdBcl2 for another 24 h. Western blot analysis was performed showing that GATA4 depletion-induced autophagy was reversed by Bcl2 overexpression.