Abstract
Purpose: :
Oxidative stress is a major risk factor that contributes to RPE damage leading to retina degeneration in diseases such as age-related macular degeneration (AMD). In this study we investigate protein networking of oxidative stress by using 2D differential gel electrophoresis. Major hub proteins and minor membrane associated enzymes in this network were selected for further study. These proteins may serve as new biomarkers of oxidative stress and therapeutic targets for AMD treatment.
Methods: :
RPE from Bovine eye cups and the RPE cell line D407 were treated with various amounts of hydrogen peroxide or PBS. Total proteins were extracted then separated on two-dimensional gel electrophoresis. Differences in protein expression were examined using quantitative fluorescent dye labeling. Proteins were identified by MALDI-TOF-TOF mass spectrometry and their post-translational modifications were studied. Proteome network of oxidative stress was investigated using various bioinformatics tools.
Results: :
Several RPE proteins showed altered expression in response to oxidative stress. These includes signal transduction molecules responsive to reactive oxygen species such as prohibitin, guanine nucleotide binding proteins and plasminogen activator inhibitor 1, metabolic enzymes involved in nucleotides and protein syntheses represented by RNA helices and translation elongation factors, chaperones and redox-balance proteins of the heat shock family and peroxiredoxins, and a mitochondrial ion channel involved in apoptosis . Proteome network focused on minor membrane-bound enzymes and major hub proteins implies that MAPK and ERK pathway are involved in this process.
Keywords: retinal pigment epithelium • oxidation/oxidative or free radical damage • proteomics