SMAD3

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 is a cell-permeable pyrrolopyridine compound that selectively inhibits TGF-β1-dependent Smad3 phosphorylation and Smad3-mediated cellular signaling with no effect on Smad2, p38 MAPK, ERK, or PI 3-K signaling. 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.