Adropin protects against cardiac remodeling and metabolic dysfunction in a male mouse HFpEF model

Cardiometabolic heart failure with preserved ejection fraction (HFpEF) is a heterogenous metabolic disease, which in the heart presents as left ventricle diastolic dysfunction, ventricular stiffness, and myocardial structural remodeling. Deleterious changes in cardiac metabolism are central to HFpEF pathophysiology, and proposed treatments for the disease have focused on repairing these defects. In the present study, we used a preclinical mouse model that recapitulates cardiometabolic HFpEF to elucidate the molecular mechanisms driving cardiac dysfunction and tested whether recombinant adropin (Adr.) (a liver- and brain-derived endogenous peptide hormone) could reverse observed defects. We show that long-term treatment with Adr. reversed multiple markers of HFpEF-related cardiac dysfunction (including fibrosis, diastolic dysfunction, and cardiomyocyte hypertrophy). Using untargeted metabolomics, we found that Adr. treatment reduced hexosamine biosynthesis pathway activity, leading to a reduction in the O-GlcNAcylation of the cardiac fatty acid oxidation enzyme long-chain acyl-CoA dehydrogenase (LCAD). Reducing LCAD O-GlcNAcylation increased LCAD activity in vitro and reduced the accumulation of long-chain acylcarnitines in HFpEF mouse hearts in vivo. Our results suggest that Adr. may restore cardiac metabolic function in HFpEF and that targeting this pathway may be a novel therapeutic avenue for this disease.