Characterisation of Dupuytren's disease and control tissue specimens. (A) Immunostaining of Dupuytren's disease (DD) and control tissue specimens for transforming growth factor β3 (TGF-β3), phosphorylated Smad2 (P-Smad2), α-smooth muscle actin (α-SMA) and H & E. Representative staining from DD patient 4 and control patient 1 is shown. Insets within each image are higher-magnification views. Evaluation of all four control and DD tissue samples are described in Table 2. (B) Protein expression analysis for P-Smad2; phosphorylated Smad3 (P-Smad3); total Smad2, Smad3 and Smad1; α-SMA; type I collagen; and fibronectin/ED-A by Western blot analysis of 100 μg of total protein extract isolated from four individual control patient-derived and four individual DD patient-derived tissue samples. β-actin was used as a loading control.