Figure 1: SMAD7 overexpression inhibits TGF-β1-induced extracellular matrix protein production in fibroblasts derived from human Peyronie's disease plaque. Fibroblasts were transfected with an empty PEI25k/pCMV5 vector or a PEI25k/pCMV5-Smad7 polyplex (pSmad7) for 48 h and were then treated with TGF-β1 (10 ng ml−1) for 24 h. ( a ) A representative Western blot for PAI-1, fibronectin, collagen I, and collagen IV in fibroblasts. ( b ) Data are presented as the relative density of each protein compared with that of β-actin. Each bar depicts the mean values (± s.e.) from four experiments per group. *P < 0.05 by Kruskal-Wallis tests. PAI-1: plasminogen activator inhibitor-1; PEI: poly (ethyleneimine); TGF-β1: transforming growth factor-β1; SMAD7: decapentaplegic homolog 7; s.e.: standard error.