Figure 4. Inhibitory effect of R667 on the TGF-β1-induced phosphorylation of FAK in HTFs cultured in collagen gels. A: 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 phosphorylated (p-) or total forms of focal adhesion kinase (FAK). The
abundance of β-actin was examined as an internal control. B: Immunoblots similar to those in (A) were subjected to densitometric analysis to determine the intensity of each band for phosphorylated FAK relative to that
of the corresponding band for FAK. Data are means ± standard deviation (SD) from three independent experiments. *p<0.01 versus
the corresponding value for cells cultured without TGF-β1; †p<0.05 versus the corresponding value for cells cultured with
TGF-β1 alone (the Tukey-Kramer test).