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. Author manuscript; available in PMC: 2009 Jun 29.
Published in final edited form as: Am J Physiol Renal Physiol. 2008 Mar 19;294(5):F1076–F1083. doi: 10.1152/ajprenal.00323.2007

Figure 8.

Figure 8

Smad2 and Smad3 mediate fibronection induction by TGF-β1 in tubular epithelial cells. (A–C) Knockdown of Smad2 and Smad3 expression by siRNA. HKC-8 cells were transiently transfected with control siRNA, Smad2 siRNA or Smad3 siRNA (120 nM). Representative Western blots show the expression levels of Smad2 and Smad3 (A) at 72 h after transfection. Graphic presentations of the relative abundance of Smad2 (B) and Smad3 (C) protein levels after normalization with actin are also given. Data (relative to the controls = 1.0) are presented as mean ± SEM of four experiments. ** P <0.01 versus control siRNA group. (D, E) Knockdown of Smad2 and Smad3 expression inhibited the TGF-β1-mediated fibronectin induction. HKC-8 cells were transiently transfected with control siRNA, Smad2 siRNA or Smad3 siRNA (120 nM) for 24 h, followed by incubation without or with different concentrations of TGF-β1 for 48 h. (F, G) Overexpression of Smad2 and Smad3 enhance TGF-β1-mediated fibronectin expression in tubular epithelial cells. HKC-8 cells were transiently transfected with empty pcDNA3 vector, HA-tagged Smad2 or HA-tagged Smad3 expression vector for 24 h, respectively, and then treated with TGF-β1 for an additional 48 h. Whole-cell lysates were immunoblotted with anti-fibronectin and anti-GAPDH antibodies, respectively.