458-P: Resveratrol Attenuates Diabetic Cardiomyopathy by Inhibiting Asymmetric Dimethylarginine-Induced PGC-1a Acetylation

Abstract

The cardiac protection of resveratrol may due to improvement of mitochondrial function through SIRT1 activation and PGC-1α deacetylation. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, is associated with diabetic cardiovascular complications and reported to have cross-talk with lysine acetylation in cells. This study was to determine the role of ADMA in the pathogenesis of diabetic cardiomyopathy, whether resveratrol could revise ADMA-induced pathological changes and elucidate the underlying mechanisms in rat model of type 2 diabetes mellitus (T2DM). Resveratrol was orally administered (50mg/kg/d) to T2DM rats for 16w. Echocardiography was performed to detect cardiac function. Contents of myocardial ATP and mitochondrial DNA were measured to evaluate mitochondrial function and biogenesis. Elevated endogenous ADMA content and its signal disorders were associated with cardiac and mitochondrial dysfunction in the myocardium of T2DM rats compared with control rats. Treatment with resveratrol significantly attenuated endogenous ADMA accumulation and cardiac dysfunction, increased myocardial mitochondrial DNA and ATP contents, as well as upregulated PGC-1α expression in the myocardium of resveratrol-treated diabetic rats compared with untreated diabetic rats. A positive feedback was observed in vitro that elevated ADMA return promoting its synthetic enzyme PRMT1 expression, reducing its metabolic enzymes DDAH2 expression, reproducing myocardial hypertrophy and mitochondrial dysfunction. Resveratrol treatment could reverse these pathological changes. More importantly, ADMA could enhance PGC-1α acetylation and reduced SIRT1 expressions, all of which were antagonized by resveratrol in cardiomyocytes. These results suggest that ADMA-induced PGC-1α hyperacetylation may serve as potential therapeutic targets for resveratrol to improve diabetic cardiomyopathy.