Urolithin A activates mitophagy via the AMPK–mTOR axis and modulates the gut–ceramide axis to ameliorate cardiac remodeling in HFpEF

Heart failure with preserved ejection fraction (HFpEF) accounts for nearly half of all heart failure cases. However, effective therapies targeting its underlying pathophysiological mechanisms remain lacking. Previous studies have indicated mitochondrial dysfunction and impaired mitophagy as key contributors to HFpEF pathophysiology. In this study, we investigated whether urolithin A (UA), a gut microbiome-derived mitophagy-activating compound, can ameliorate HFpEF. A two-hit mouse model was established using a high-fat diet and Nω-nitro-L-arginine methyl ester, and UA was administered during disease progression. In vitro and in vivo experiments, together with multi-omics analyses, showed that UA alleviated diastolic dysfunction, cardiac hypertrophy, and fibrosis in HFpEF mice. These effects were accompanied by restoration of mitochondrial ultrastructure and enhanced mitochondrial respiration and glycolytic capacity. Notably, UA activated AMPK signaling while inhibiting mTOR, promoting ULK1-dependent autophagy initiation and restoring impaired mitophagic flux. These effects were associated with improved mitochondrial quality control and function. Concurrently, multi-omics analyses revealed that UA remodels the gut microbiome-ceramide axis and reduces circulating ceramide accumulation, thereby alleviating lipotoxic stress. Furthermore, single-nucleus transcriptomic analysis revealed that UA treatment leads to the attenuation of fibrosis-related cellular programming in human induced pluripotent stem cell-derived cardiomyocytes. Taken together, these findings indicate that UA improves cardiac remodeling in HFpEF by activating mitophagy-dependent mitochondrial quality control and modulating the gut microbiome-ceramide axis, highlighting its potential as a mechanism-based, mitochondria-targeted therapeutic strategy for HFpEF.