Sirtuin 1 ablation in endothelial cells is associated with impaired angiogenesis and diastolic dysfunction

Discordant myocardial growth and angiogenesis can explain left ventricular (LV) hypertrophy progressing toward heart failure with aging. Sirtuin 1 expression declines with age; therefore we explored the role played by angiogenesis and Sirtuin 1 in the development of cardiomyopathy. We compared the cardiac function of 10- to 15-wk-old (wo), 30–40 wo, and 61–70 wo endothelial Sirtuin 1-deleted (Sirt1endo−/−) mice and their corresponding knockout controls (Sirt1Flox/Flox). After 30–40 wk, Sirt1endo−/− animals exhibited diastolic dysfunction (DD), decreased mRNA expression of Serca2a in the LV, and decreased capillary density compared with control animals despite a similar VEGFa mRNA expression. However, LV fibrosis and hypoxia-inducible factor (HIF)1α expression were not different. The creation of a transverse aortic constriction (TAC) provoked more severe DD and LV fibrosis in Sirt1endo−/− compared with control TAC animals. Although the VEGFa mRNA expression was not different and the protein expression of H...