Adiponectin activates AKT and protects rat cardiomyocytes against H2O2-induced apoptosis

AIM: To study the effect of adiponectin on H₂O₂-induced apoptosis in rat cardiomyocytes (H9c2 cells). METHODS: Terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) was used to determine H₂O₂-induced apoptosis of H9c2 cells in the absence or presence of adiponectin. The content of caspase-3 and Akt (protein kinase B, PKB) was examined by Western blotting. RESULTS: Adiponectin significantly inhibited H₂O₂-induced apoptosis in H9c2 cells (P<0.01). Adiponectin increased basal and H₂O₂-induced Akt activity and significantly inhibited H₂O₂-induced activation of caspase-3 (P<0.01). Pretreatment with LY294002, a specific inhibitor of Akt upstream kinase PI3K (phosphatidylinositol 3-kinase), not only increased H₂O₂-induced H9c2 cell apoptosis, but also abrogated the anti-apoptotic effect of adiponectin. CONCLUSION: Adiponectin protects H9c2 cells against H₂O₂-induced apoptosis by activating PI3K/Akt signaling pathway.