Modulation of Oxidative Stress Responses by Vitamin E, or Vitamin A plus Vitamin C Treatment in Human Retinal Pigment Epithelial Cells

Abstract

The purpose of this study was to characterize the potential of vitamins to protect the retinal pigment epithelium (RPE) from oxidative stress (OS). We have previously shown that OS induces the expression of AP1 transcription factors (FOSB, CFOS and ATF3), but is modulated by pretreatment with vitamin C (200 mM). We propose that OS-induced AP1 expression can be used as a biomarker of OS to test the efficacy of vitamins to limit the impact of OS in the RPE. Here we examined the efficacy of vitamin E or combined vitamin A plus vitamin C to modulate OS-induced AP1 expression in the RPE. We pretreated human ARPE-19 cells with vitamin E (0 - 7.5 mM) or with combined vitamin A (10 or 15 mM) plus vitamin C (50 or 100 mM) for 3 days prior to exposure to 500 mM H2O2 OS for 1 - 4 h. AP1 expression was assessed using qRT-PCR. Pretreatment with ≥2.5 mM vitamin E significantly decreased OS-induced AP1 expression at 1 - 4 h OS, compared to controls. Lower doses of vitamin E were ineffective at