ML216 Alleviates Age-Related Cardiac Fibrosis by Suppressing TGF-β1 Signaling Pathway

Cardiac fibrosis is a hallmark of cardiac aging and a major contributor to development of heart failure. However, therapeutic strategies that specifically target cardiac fibrosis remain limited. In this study, we demonstrate that small-molecule compound ML216 exerts protective effects against aging-associated or β-adrenoceptor agonist isoproterenol-induced cardiac fibrosis in vitro or in vivo. Mechanistically, ML216 inhibits transforming growth factor-β1 (TGF-β1) signaling by reducing TGF-β1 protein levels, thereby attenuating Mothers against decapentaplegic homolog (SMAD) phosphorylation and downstream induction of connective tissue growth factor (CTGF). This leads to a marked suppression of fibrotic genes Col1a1, Cnn2, and Acta2, ultimately resulting in reduced fibrosis. Additionally, the inhibition of the TGF-β1 pathway alleviates cardiomyocytes apoptosis, which may further limit inflammatory responses and contributes to the overall attenuation of cardiac fibrosis. Collectively, these findings demonstrate that ML216 mitigates cardiac fibrosis through the inhibition of TGF-β1 pathway-mediated fibrotic signaling and apoptosis, highlighting its potential as a therapeutic candidate for the treatment of cardiac fibrosis.