망막색소상피세포에서 TGF-β에 의한 섬유성 신호전달에 미치는 pirfenidone의 효과Inhibitory effect of pirfenidone on TGF-beta-induced fibrosis signaling of retinal pigment epithelial cells
Purpose: Fibrotic disorders of the retina are characterized by excessive proliferation of retinal pigment epithelial cells (RPE), which is mainly mediated by transforming growth factor-β(TGF- β). The purpose of this study is to examine the in vitro effect of pirfenidone, a novel anti-fibrotic agent, on the TGF-β-mediated epithelial-mesenchymal transition in human RPE cells. Materials and Methods: The effect of pirfenidone on the TGFβ-induced phenotype in ARPE-19, a human RPE cell line, were measured as the changes in a-smooth muscle actin and F-actin by western blot and immunofluorescence staining. The induction of fibronectin and collagen was examined by ELISA, while cell migration was measured by a cell scratch assay. Immunoblot analysis of smad 2/3, p38 MAPK and cofilin expression was performed to delineate the signaling responsible for the anti-fibrotic effect of pirfenidone. Results: The treatment with TGF-β induced the expression of a-smooth muscle actin, fibroblast-like morphological changes and cellular migration of ARPE-19 cells, which was suppressed by pirfenidone. Moreover, pretreatment with pirfenidone significantly inhibited the TGF-β-induced expression of extracellular matrix components such as collagen type I and fibronectin. Treatment with TGF-βinduced the time-dependent phosphorylation of smad2/3, p38 MAPK and cofilin, which was abrogated by pretreatment with pirfenidone. Conclusion: Our results suggest the potential of pirfenidone as a novel anti-fibrotic agent for fibrotic retinal disorders.