Enhanced cardiac mitochondrial biogenesis by nitro-oleic acid remedies diastolic dysfunction in a mouse model of heart failure with preserved ejection fraction

Prevalence of heart failure with preserved ejection fraction (HFpEF) is increasing, while treatment options are inadequate. Hypertension and obesity-related metabolic dysfunctions contribute to HFpEF progression. Nitro-oleic acid (NO2-OA) impacts metabolic processes by improving glucose tolerance and adipocyte function. In this study, 4 week treatment with NO2-OA ameliorated diastolic dysfunction in a HFpEF mouse model induced by high-fat diet and inhibition of the endothelial nitric oxide synthase. A proteomic analysis of left ventricular tissue revealed, that one third of the identified proteins, mostly mitochondrial proteins, were upregulated in hearts of NO2-OA-treated HFpEF mice compared to controls and vehicle-treated HFpEF mice, which was confirmed by immunoblot. Activation of the 5-adenosine-monophosphate-activated-protein-kinase (AMPK) signaling pathway mediated an enhancement of mitochondrial biogenesis in hearts of NO2-OA-treated HFpEF mice. In cardiomyocytes under metabolic stress, NO2-OA increased mitochondrial protein level accompanied by enhanced oxidative phosphorylation. In conclusion, targeting mitochondrial integrity in HFpEF leads to improved diastolic function.