H-J. AT-MSCs were transfected with 50 nM miR-21 inhibitor or control inhibitor, and were exposed to r.h. TGF-β1 2 days after transfection at indicated concentrations for another 24 h, and subsequently subjected to the analysis of expression of miR-21 (H), Smad7 protein (I) and human TGF-β1 mRNA (J). Data is given as mean ± SEM of three independent experiments. 