Figure 5.

Conditioned medium from TβRII^−/− CD cells stimulates increased collagen I production by interstitial cells. (A) Fibroblasts are incubated with conditioned medium from both TβRII^flox/flox and TβRII^−/− CD cells and immunoblotted for collagen I expression in the presence or absence of 2G7 (a blocking pan–TGF-β antibody at 20 μg/ml). Fibroblasts are incubated with serum-free (SF) medium as a negative control. The white lines separating samples represent where the order of samples within the same blot was changed. (B) Densitometry of collagen I/focal adhesion kinase (FAK) is performed using three separate experiments and reported as means ± SEM. *P < 0.05. (C) Conditioned medium from CD cells with and without TβRII is placed on fibroblasts in the presence or absence of 2G7 (blocking pan–TGF-β antibody) for varying periods, after which the fibroblasts are lysed and immunoblotted for pSmad2. The vertical white line separating samples indicates where the order of samples from the same experiment on two gels developed for equivalent times is changed.