PURPOSE: To examine whether transforming growth factor-beta 2 (TGF-beta 2) induces the expression of alpha-smooth muscle actin (SMA), a biochemical marker of myofibroblasts, in cultured bovine retinal pigment epithelial (RPE) cells. METHODS: Bovine RPE cells were cultured in F-12 nutrient mixture supplemented with 5% fetal bovine serum (FBS), with or without TGF-beta 2 (0.01-10 ng/ml) for 6 days. During this culture period, cells did not reach a confluence. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the ratio of the number of alpha-SMA positive cells to the total number of cells was calculated. RESULTS: About 10% of the cells in control cultures with only FBS were positive for alpha-SMA. TGF-beta 2 increased the ratio of positive cells dose-dependently (p < 0.0001), while a neutralizing antibody against TGF-beta 2 blocked this effect. CONCLUSIONS: TGF-beta 2 induced expression of alpha-SMA in bovine RPE cells.
PURPOSE: To examine whether transforming growth factor-beta 2 (TGF-beta 2) induces the expression of alpha-smooth muscle actin (SMA), a biochemical marker of myofibroblasts, in cultured bovine retinal pigment epithelial (RPE) cells. METHODS:Bovine RPE cells were cultured in F-12 nutrient mixture supplemented with 5% fetal bovine serum (FBS), with or without TGF-beta 2 (0.01-10 ng/ml) for 6 days. During this culture period, cells did not reach a confluence. Alpha-SMA was detected immunocytochemically with a mouse monoclonal antibody, and the ratio of the number of alpha-SMA positive cells to the total number of cells was calculated. RESULTS: About 10% of the cells in control cultures with only FBS were positive for alpha-SMA. TGF-beta 2 increased the ratio of positive cells dose-dependently (p < 0.0001), while a neutralizing antibody against TGF-beta 2 blocked this effect. CONCLUSIONS:TGF-beta 2 induced expression of alpha-SMA in bovine RPE cells.