p53 Acetylation Exerts Critical Roles in Pressure Overload-Induced Coronary Microvascular Dysfunction and Heart Failure in Mice.

Background: Coronary microvascular dysfunction (CMD) has been shown to contribute to cardiac hypertrophy and heart failure (HF) with preserved ejection fraction. At this point, there are no proven treatments for CMD.

Methods: We have shown that histone acetylation may play a critical role in the regulation of CMD. By using a mouse model that replaces lysine with arginine at residues K98, K117, K161, and K162R of p53 (p53), preventing acetylation at these sites, we test the hypothesis that acetylation-deficient p53 could improve CMD and prevent the progression of hypertensive cardiac hypertrophy and HF. Wild-type and p53 mice were subjected to pressure overload by transverse aortic constriction to induce cardiac hypertrophy and HF.

Results: Echocardiography measurements revealed improved cardiac function together with a reduction of apoptosis and fibrosis in p53 mice. Importantly, myocardial capillary density and coronary flow reserve were significantly improved in p53 mice. Moreover, p53 upregulated the expression of cardiac glycolytic enzymes and Gluts (glucose transporters), as well as the level of fructose-2,6-biphosphate; increased PFK-1 (phosphofructokinase 1) activity; and attenuated cardiac hypertrophy. These changes were accompanied by increased expression of HIF-1α (hypoxia-inducible factor-1α) and proangiogenic growth factors. Additionally, the levels of SERCA-2 were significantly upregulated in sham p53 mice, as well as in p53 mice after transverse aortic constriction. In vitro, p53 significantly improved endothelial cell glycolytic function and mitochondrial respiration and enhanced endothelial cell proliferation and angiogenesis. Similarly, acetylation-deficient p53 significantly improved coronary flow reserve and rescued cardiac dysfunction in SIRT3 (sirtuin 3) knockout mice.

Conclusions: Our data reveal the importance of p53 acetylation in coronary microvascular function, cardiac function, and remodeling and may provide a promising approach to improve hypertension-induced CMD and to prevent the transition of cardiac hypertrophy to HF.