B-D. AT-MSCs were transfected with 30 nM Smad7-siRNAs or control siRNA. Untransfected AT-MSCs served as control. RNA and protein were isolated 2 days after transfection for Smad7 expression by qPCR (B) and western blot (C). The remaining cells were treated with r.h. TGF-β1 at indicated concentrations for another 24 h. The expression of human TGF-β1 was analyzed by qPCR and normalized on human GAPDH (D). Data is given as mean ± SEM of three independent experiments. 