Epitranscriptomic regulation of cardiac fibrosis via YTHDF1-dependent PIEZO2 mRNA m6A modification.

Background: Mechanosensitive ion channels play a key role in heart development, physiology, and disease. However, little is known about the molecular mechanisms of the mechanosensitive nonselective cationic channel Piezo family in cardiac fibrosis.

Methods and results: Mice were treated with ISO/Ang-II/TAC to induce cardiac fibrosis. AAV9 carrying POSTN promoter-driven small hairpin RNA targeting YTHDF1, and Piezo2 were administered to ISO mice to investigate their roles in cardiac fibrosis. RNA-seq, single-cell sequencing, and histological and biochemical analyses were performed to determine the mechanism by which YTHDF1 regulates Piezo2 expression in cardiac fibrosis. Piezo2 was reconstituted in YTHDF1-deficient cardiac fibroblasts and mouse hearts to study its effects on cardiac fibroblast autophagy and fibrosis. Piezo2 but not Piezo1 expression increased in experimental cardiac fibrosis and TGF-β1-induced cardiac fibroblasts. Fibroblast-specific Piezo2 deficiency ameliorated fibroblast activation and autophagy and inhibited cardiac fibrosis. Mechanistically, Piezo2 upregulation was associated with elevated m6A mRNA levels. Site-specific m6A modifications at peak_26355 were crucial for regulating the binding of YTHDF1 to Piezo2 mRNA and inducing Piezo2 translation. Notably, Piezo2 epitranscriptomic repression ameliorated experimental cardiac fibrosis.

Conclusions: We demonstrated a novel epitranscriptomic mechanism through which YTHDF1 recognizes Piezo2 and controls cardiac fibroblast autophagy and fibrosis through m6A-dependent modulation. Our findings provide new insights for the development of preventive measures for cardiac fibrosis.