FIGURE 4:
TGF-β induces the IPF phenotype. (A) Conditioned medium was collected from MRC5, LL29, and LL97a cells and assayed for active TGF-β present in the supernatant by ELISA. (B) MRC5 cells were treated with 10 ng/ml TGF-β for 24 h. Cells were lysed, and lysates were evaluated by Western blot for FN, collagen I, SMA, and Erk2. (C) MRC5 cells were treated with 10 ng/ml TGF-β for 24 h. Cells were lysed, and active RhoA was precipitated from lysates using GST-RBD and immunoblotted with RhoA antibodies. (D) Quantification of RhoA activity from three independent assays. (E) MRC5 cells were treated with 10 ng/ml TGF-β for 24 h. Cells were lysed, and p190 GAP activity was assessed through a GST-RhoAQ63L pull-down assay. (F) Quantification of p190 GAP activity from three independent assays. (G) MRC5 cells were treated with 10 ng/ml TGF-β for 24 h. Cells were lysed, and lysates were evaluated by Western blot with antibodies against Rnd3, Rnd2, and Rnd1. (H) Quantification of Rnd3 expression in three independent assays. *p < 0.05 vs. (–)TGF-β as determined by a t test.