Urolithin A Restores Mitochondrial Function and Reverses Cardiac Remodeling in HFpEF

Heart failure with preserved ejection fraction (HFpEF) accounts for half of all heart failure cases, yet no therapies are based on the underlying mechanisms. Mitochondrial dysfunction and defective mitophagy are key drivers of HFpEF pathogenesis. We investigated whether urolithin A (UA), a mitophagy activator produced by the gut microbiome, could reverse HFpEF. We used a two-hit mouse model involving a high-fat diet and L-NAME, administering UA during disease progression. Cardiac structure and function were evaluated using echocardiography, histology, and transmission electron microscopy. Mitochondrial bioenergetics were measured using Seahorse respirometry. Mitophagy flux was monitored via mt-Keima assays in H9c2 cells and hiPSC-derived cardiomyocytes. We also performed immunoblotting and integrated shotgun metagenomics, as well as lipidomics and single-nucleus RNA sequencing. UA was found to attenuate cardiac remodelling, fibrosis and diastolic dysfunction in HFpEF mice. Transmission electron microscopy revealed restored mitochondrial ultrastructure. Mitochondrial stress tests showed enhanced oxidative phosphorylation and glycolytic capacity. Immunoblotting confirmed the recovery of PINK1/Parkin-mediated mitophagy markers. Mt-Keima assays demonstrated increased mitophagic flux under HFpEF-like stress. Integrated multi-omics analysis revealed reduced ceramides and normalised mitochondrial quality control gene programmes. In conclusion, UA reversed cardiac remodelling in HFpEF by restoring mitophagy-mediated mitochondrial quality control, thus establishing its potential as mitochondria-targeted therapeutics.