SMAD3 Inhibitor, SIS3

SMAD3 is a receptor-regulated intracellular protein that functions downstream of TGF-β and activin receptors and mediates their signaling, playing a role in cell proliferation, differentiation, apoptosis and formation of extracellular matrix. SMAD3 Inhibitor, SIS3 selectively inhibits TGF-β and activin signaling by suppressing Smad3 phosphorylation (IC = 3 µM) without affecting the MAPK/p38, ERK, or PI3-kinase signaling pathways. It has been shown to reduce TGF-β1-induced type 1 procollagen expression and myofibroblast differentiation in normal dermal fibroblasts as well as scleroderma fibroblasts.