Figure 4. Pirfenidone inhibited transforming growth factor-β1 (TGF-β1)-induced migration of human retinal pigment epithelial cells (ARPE-19) cells. Cells were incubated in the absence or presence of varying doses of pirfenidone, SB202190 (10 μmol/l), or hydroxyfasudil (10 μmol/l) for 1 h and then scratched with a 200-μl micropipette tip to form a cell-free (wounded) area. The cells were then incubated in the absence or presence of TGF-β1 (10 μg/l) for an additional 48 h. The vertical axis represents the number of cells that migrated into the wounded region. Stacked bars display the portion of migratory cells classified by migration distance (the gray bar indicates the number of cells that migrated a moderate distance, and the black bar indicates the number of cells that migrated the longest distance). Samples significantly different from the control sample treated with DMSO were indicated with symbols (*, error bar indicates standard deviation (SD), p<0.05; **, p<0.0001; n=10).