Targeting an atypical G protein-coupled receptor signaling pathway for cardiac fibrosis therapy.

Cardiac fibrosis independently predicts adverse outcomes in heart failure (HF), yet no Food and Drug Administration-approved therapy directly targets fibrotic remodeling in the heart. To address this unmet clinical need, we used a multidimensional drug discovery pipeline centered on a human induced pluripotent stem cell (iPSC)-based platform. Through high-throughput screening, we identified CGS15943 (CGS) as the lead antifibrotic compound and validated its activity in human cardiac fibroblasts, three-dimensional engineered heart tissues, and animal models of HF. Mechanistic studies revealed an atypical adenosine receptor (AR)-dependent signaling pathway in which AR subtypes converge on Gβγ (the βγ subunits of heterotrimeric GTP-binding proteins) to activate phosphoinositide 3-kinase (PI3K)-AKT and yes-associated protein (YAP). CGS suppressed this signaling axis, thereby reducing fibrotic gene expression and fibroblast activation. These findings establish AR-driven Gβγ signaling as a potential therapeutic target for cardiac fibrosis.