Peroxiredoxin 6 attenuates hydrogen peroxide-induced RPE cell's oxidative damage via EGFR/ERK signaling pathway

Abstract

Purpose : Oxidative injury of retinal pigment epithelium (RPE) cells is involved in the pathogenesis of several blinding retinal diseases, such as Age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerations. The mechanisms involved in this process remain poorly understood. The goal of this study was to investigate the role of peroxiredoxin 6 (PRDX6) on H₂O₂-induced oxidative stress in RPE cells.

Methods : Human RPE cell lines (ARPE-19 cells) were treated with hydrogen peroxide (H₂O₂) and epidermal growth factor (EGF). Cell viability was tested by a methyl thiazolyl tetrazolium(MTT) assay. Additionally, cell death and reactive oxygen species (ROS) were detected by flow cytometry. PRDX6, EGF receptor (EGFR), extracellular signal-regulated kinase (ERK), P38 mitogen-activated protein kinase (P38MAPK), and c-Jun N-terminal kinase (JNK) were all detected by Western blot. PRDX6 and EGFR levels were also detected by immunofluorescence.

Results : H₂O₂ inhibited ARPE-19 cell viability, caused cell death, and increased ROS production in a dose-dependent manner. It also decreased the expression levels of PRDX6, EGFR, and phosphorylated ERK proteins and initiated the phosphorylation of P38MAPK and JNK proteins. The H₂O₂-induced inhibition of ARPE-19 cell viability, cell death, and increase of ROS production were all alleviated by PRDX6 overexpression. PRDX6 overexpression also increased the expression level of EGFR protein and alleviated an H₂O₂-induced decrease in expression levels of EGFR and phosphorylated ERK. Moreover, inhibition of EGF-induced EGFR and ERK signaling in oxidative stress was partly blocked by PRDX6 overexpression. PRDX6 overexpression protects RPE cells from oxidative damage by decreasing ROS production and partly blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress.

Conclusions : PRDX6 might be an important target for protecting RPE cells from oxidative damage related to retinal diseases.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.