Figure 8
Expression of T β R-1, Smad7 and Smurf2 in HPMCs stimulated by TGF- β 1 and treated with Akt, Smurf siRNA and USP4 siRNA. Panel A: Western blot profiles of TβR-1, Smad7 and Smurf2 following various treatments as indicated. The β-actin served as a loading control. Panel B: The bar graphs represent the relative density of the TβR-1 (B1), Smurf2 (B2) and Smad7 (B3) Western blots bands relative to β-actin. Treatment of TGF- β1 or over-expression of Akt (Flag-Akt) enhances the TβR-1 and Smurf2 protein expression, while it reduces the Smad7 expression. A concomitant treatment and over-expression further enhances their expression. No change is seen in cells treated with Smurf2 siRNA or USP4 siRNA alone. The TGF-β1+ Flag Akt-induced Smurf2 expression was slightly reduced by Smurf2-siRNA and not by USP4-siRNA. The Smad7 expression is reduced with TGF-β1 or Flag-Akt individually, and it is slightly reversed by Smurf2 siRNA. Panel C: Immunoprecipitation/Western blot analyses represent changes seen in interactions between Smurf2 & Smad7, and Smurf2 & TβR-1 (upper panels). The Smurf2 expression served as loading controls (bottom panels). Values are the mean ± SEM, n = 3, *p <0.01 versus control, #p <0.01 vs. TGF-β1, $p <0.01 vs. TGF-β1+ Flag-Akt.