Figure 4. TGZ suppresses TGFβ2-induced expression of fibronectin and collagen type I in subconfluent ARPE-19 cells.ARPE-19 cells at subconfluent density of 5 X 10⁵ cells per well in six-well plates were either left untreated (UT) or were treated with 4 ng/ml TGFβ2, or were pretreated with different doses of TGZ (1, 5, 10 μM; 1 h) or DMSO (0.05%, 1 h) and then incubated with TGFβ2. The expressions of fibronectin and collagen type I were assayed by RT–PCR analysis (A), western blot analysis (B), and ELISA (C) as Figures 1–3 described. *p<0.05 versus TGFβ2-treated cells. Experiments were repeated twice and the results were reproducible.