Oxidative Stress Enhanced The Transforming Growth Factor-Beta 2-Induced Epithelial-Mesenchymal Transition Through Chemokine Ligand 1 On Arpe-19 Cell

Fibroblast-like transformation of retinal pigment epithelial (RPE) cells is a pathological feature of proliferative vitreoretinopathy (PVR) that may cause blindness. The effect of oxidative stress alone or together with transforming growth factor-beta 2 (TGF-beta 2) on epithelial-mesenchymal transformation (EMT) is not fully understood in RPE. TGF-beta 2 induced the upregulation EMT markers including alpha-smooth muscle actin (alpha-SMA), Snail, and Slug and downregulation of E-cadherin (E-cad) in ARPE-19 cells. Hydrogen peroxide (H2O2) not only upregulated alpha-SMA but also enhanced the effect of TGF-beta 2 on the expression of Snail and Slug. The CXCL family of cytokines could be the mediators of EMT induced by H2O2 and TGF-beta 2. H2O2 induced CXCL1, that upregulated alpha-SMA and fibronectin. Both SB225002, an inhibitor of CXCR2, and antioxidant N-acetylcysteine suppressed the TGF-beta 2-induced EMT in ARPE-19 cells. Taken together, the results suggest that oxidative stress enhanced TGF-beta 2-induced EMT through the possible autocrine effect of CXCL1 on CXCR2 in ARPE-19 cells.