BMP9 increases collagen I, fibronectin and CTGF/CCN2 expression in fibroblasts.
BMP9 promotes both Smad1/5/8 and Smad2/3 phosphorylation in fibroblasts.
ALK1 is necessary for BMP9 to induce Smad1/5/8 and Smad2/3 phosphorylation.
Overexpression of endoglin increases BMP9-induced Smad1/5/8 and Smad2/3 phosphorylation and its profibrotic properties.