(A, B) Reduced Tgf-β signaling by Srf (A), or Mrtf1a/b silencing (B), as assessed by Tgf-β-responsive Smad-binding-element (SBE)-luciferase reporter assay (n=4/group). *P < 0.05, ** P < 0.01, *** P < 0.001. (C) Immunoblot analysis of Tgf-β-induced Smad2 and Smad3 phosphorylation (2ng/ml, 1hr) in shSrf-expressing 10T1/2 cells as compared to shScr control. *P < 0.05, ** P < 0.01. (D, E) Induction of BMP signaling in 10T1/2 cells with inhibition of Srf (D), or Mrtfa/b (E), as assessed by BMP-responsive luciferase reporter assay (n=4/group). (F, G) Immunoblot analysis of Smad1/5 phosphorylation upon BMP4 treatment (1ng/ml, 40min) in shSrf-expressing (F), or shMrtf-expressing (G), as compared to shScr 10T1/2 cells.