Preconditioning Protect the ARPE–19 Cells from Oxidative Stress Induced Cell Death

Abstract

Abstract: : Purpose:Oxidative stress plays an important role in numerous ocular diseases including age related macular degeneration (AMD). Injury to retinal pigment epithelium (RPE) cells plays a pivotal role in the pathogenesis of AMD. In this study we investigated the effect of preconditioning on oxidative stress–induced apoptosis in a widely used RPE cell line (ARPE–19). Methods: Optimum doses of H₂O₂ for inducing cell death in ARPE–19 cells was determined. Cultured ARPE–19 cells were preconditioned with various small, non–lethal doses of H₂O₂. In the preconditioned cells, death was induced by a lethal dose of H₂O₂. Cell death was quantitated. Effect of increasing doses of H₂O₂ were also noted on cell attachment. Results: The optimum dose for inducing cell–death in ARPE–19 cells was between 600–900 µM. No cell death was observed when cells were exposed to lower doses of H₂O_2. Preconditioning the cells with 0.1, 1, 10 and 50 µM of H₂O₂ showed dose–dependent, increasing protection against apoptosis induced by a lethal dose (700–900 µM) of H₂O₂. There was dose–dependent inhibition of cell attachment to the substrate. Conclusions: Results show that preconditioning the cells with small, non–lethal doses of oxidative stress confers significant protection against lethal dose induced cell death. Presumably, during preconditioning protective cellular pathways are up–regulated. This finding may help in understanding the pathogenesis of diseases in which oxidative stress plays an important role, and to develop treatment strategies.

Keywords: age–related macular degeneration • cell death/apoptosis • oxidation/oxidative or free radical damage