Background-Diet-induced obesity is associated with metabolic heart disease characterized by left ventricular hypertrophy and diastolic dysfunction. Polyphenols such as resveratrol and the synthetic flavonoid derivative S17834 exert beneficial systemic and cardiovascular effects in a variety of settings including diabetes mellitus and chronic hemodynamic overload. Methods and Results-We characterized the structural and functional features of a mouse model of diet-induced metabolic syndrome and used the model to test the hypothesis that the polyphenols prevent myocardial hypertrophy and diastolic dysfunction. Male C57BL/6J mice were fed a normal diet or a diet high in fat and sugar (HFHS) with or without concomitant treatment with S17834 or resveratrol for up to 8 months. HFHS diet-fed mice developed progressive left ventricular hypertrophy and diastolic dysfunction with preservation of systolic function in association with myocyte hypertrophy and interstitial fibrosis. In HFHS diet-fed mice, there was increased myocardial oxidative stress with evidence of oxidant-mediated protein modification via tyrosine nitration and 4-OH-2-nonenol adduction. HFHS diet-fed mice also exhibited increases in plasma fasting glucose, insulin, and homeostasis model assessment of insulin resistance indicative of insulin resistance. Treatment with S17834 or resveratrol prevented left ventricular hypertrophy and diastolic dysfunction. For S17834, these beneficial effects were associated with decreases in oxidant-mediated protein modifications and hyperinsulinemia and increased plasma adiponectin. Conclusions-Resveratrol and S17834 administered concurrently with a HFHS diet prevent the development of left ventricular hypertrophy, interstitial fibrosis, and diastolic dysfunction. Multiple mechanisms may contribute to the beneficial effects of the polyphenols, including a reduction in myocardial oxidative stress and related protein modifications, amelioration of insulin resistance, and increased plasma adiponectin. The polyphenols resveratrol and S17834 may be of value in the prevention of diet-induced metabolic heart disease. (Circulation. 2012;125:1757-1764.)

BackgroundA hallmark of aging of the cardiac myocyte is impaired sarcoplasmic reticulum (SR) calcium uptake and relaxation due to decreased SR calcium ATPase (SERCA) activity. We tested the hypothesis that H2O2‐mediated oxidation of SERCA contributes to impaired myocyte relaxation in aging.Methods and ResultsYoung (5‐month‐old) and senescent (21‐month‐old) FVB wild‐type (WT) or transgenic mice with myocyte‐specific overexpression of catalase were studied. In senescent mice, myocyte‐specific overexpression of catalase (1) prevented oxidative modification of SERCA as evidenced by sulfonation at Cys674, (2) preserved SERCA activity, (3) corrected impaired calcium handling and relaxation in isolated cardiac myocytes, and (4) prevented impaired left ventricular relaxation and diastolic dysfunction. Nitroxyl, which activates SERCA via S‐glutathiolation at Cys674, failed to activate SERCA in freshly isolated ventricular myocytes from senescent mice. Finally, in adult rat ventricular myocytes in primary culture, adenoviral overexpression of SERCA in which Cys674 is mutated to serine partially preserved SERCA activity during exposure to H2O2.ConclusionOxidative modification of SERCA at Cys674 contributes to decreased SERCA activity and impaired myocyte relaxation in the senescent heart. Strategies to decrease oxidant levels and/or protect target proteins such as SERCA may be of value to preserve diastolic function in the aging heart.