Oxidative stress affects retinal pigment epithelial cell survival through epidermal growth factor receptor/AKT...

To investigate the cross-talk between oxidative stress and the epidermal growth factor receptor (EGFR)/AKT signaling pathway in retinal pigment epithelial (RPE) cells.

Human RPE cell lines (ARPE-19 cell) were treated with different doses of epidermal growth factor (EGF) and hydrogen peroxide (H₂O₂). Cell viability was determined by a methyl thiazolyl tetrazolium assay. Cell proliferation was examined by a bromodeoxyuridine (BrdU) incorporation assay. EGFR/AKT signaling was detected by Western blot. EGFR localization was also detected by immunofluorescence. In addition, EGFR/AKT signaling was intervened upon by EGFR inhibitor (erlotinib), PI3K inhibitor (A66) and AKT inhibitor (MK-2206), respectively. H₂O₂-induced oxidative stress was blocked by antioxidant N-acetylcysteine (NAC).

EGF treatment increased ARPE-19 cell viability and proliferation through inducing phosphorylation of EGFR and AKT. H₂O₂ inhibited ARPE-19 cell viability and proliferation and also suppressed EGF-stimulated increase of RPE cell viability and proliferation by affecting the EGFR/AKT signaling pathway. EGFR inhibitor erlotinib blocked EGF-induced phosphorylation of EGFR and AKT, while A66 and MK-2206 only blocked EGF-induced phosphorylation of AKT. EGF-induced phosphorylation and endocytosis of EGFR were also affected by H₂O₂ treatment. In addition, antioxidant NAC attenuated H₂O₂-induced inhibition of ARPE-19 cell viability through alleviating reduction of EGFR, and phosphorylated and total AKT proteins.

Oxidative stress affects RPE cell viability and proliferation through interfering with the EGFR/AKT signaling pathway. The EGFR/AKT signaling pathway may be an important target in oxidative stress-induced RPE cell dysfunction.