SS‐31 protect retinal pigment epithelial cells from H(2)O(2)‐induced cell injury by reducing apoptosis

Evidence has shown that effects from oxidative stress induced damage of retinal or human retinal pigment epithelial (RPE) cells. Antioxidant supplementation is a plausible strategy to avoid oxidative stress and maintain the function of retina. d‐Arg‐2,6‐dimethyltyrosine‐Lys‐Phe‐NH2 (SS‐31) has been used in the treatment of many diseases. In this study, we found that SS‐31 attenuated hydrogen peroxide (H(2)O(2))‐induced loss of cell viability, reduced oxidative damage and cell apoptosis in RPE cells. HO‐1, Trx‐1 and Nrf‐2 expression levels significantly increased on pre‐treatment with SS‐31 compared with the H(2)O(2) group. SS‐31 inhibited apoptosis through the downregulation of Bax and the upregulation of Bcl‐2. Our results suggest that SS‐31 had a protective effect against H(2)O(2) treatment in ARPE‐19 cells by enhancing the antioxidative enzymes expression and decreasing apoptosis, which could be considered a promising therapeutic intervention for retinal degeneration.