RUNX2 Promotes Fibrotic Activation in Skin Fibroblasts and Is Targetable by Small-Molecule Inhibition

Fibrosis is driven by activated fibroblasts, but key transcriptional regulators remain unclear. We investigated the role of RUNX2 using three human skin fibroblast lines with RUNX2 knockdown (shRUNX2) and matched controls (shControl), treated with or without TGF-β, followed by bulk RNA sequencing. RUNX2 depletion attenuated TGF-β–induced pro-fibrotic gene programs, including extracellular matrix organization and myofibroblast differentiation. In primary fibroblasts, the small molecule F0565-0303 reduced TGF-β–induced fibrotic signatures and decreased RUNX2 expression, partially mimicking RUNX2 knockdown, while showing minimal effects under basal conditions. These results identify RUNX2 as a key driver of fibroblast activation and support its pharmacological targeting as an anti-fibrotic strategy.