Figure 5. Effect of R667 on α-SMA expression in HTFs cultured in collagen gels. Cells embedded in collagen gels were incubated first for 12 h with various concentrations of R667 and then for 3 days in the additional absence or presence of transforming growth factor-β1 (TGF-β1; 1 ng/ml). Cell lysates were then prepared and subjected to immunoblot analysis with antibodies to alpha-smooth muscle actin (α-SMA). The abundance of β-actin was examined as an internal control. Data are representative of three independent experiments.