Abstract
Purpose: :
Oxidative stress plays an important role in the pathogenesis of AMD. Current studies have demonstrated that miRNAs are involved in regulation of cell survival in response to oxidative stress. The purpose of this study is to investigate miR-23a expression level in RPE cells from AMD donor eyes. Furthermore, the role of miR-23a in modulating RPE cells survival in response to oxidative stress have been studied.
Methods: :
The expression of miR-23a in macular RPE cells from AMD donor eyes and age-match normal control donor eyes were analyzed by qRT-PCR. Cultured ARPE-19 cells were transfected with miR-23a mimic or inhibitor and treated with different concentration of H2O2. Apoptosis were determined by the cell Death Detection ELISA plus kit (Roche, Hertfordshire, UK). Caspase-3 activity and DNA fragmentation was measured using an enzyme-linked immunosorbent assay. Fas expression level was determined by Western blot.
Results: :
The expression level of MiR-23a decreased in macular RPE cells from AMD donor compare to normal control. Over-expression of pre-miR-23a in ARPE-19 cells decreased the cell death induced by H2O2. In contrast, miR-23 inhibitor promoted ARPE-19 cell death induced by H2O2. Computational analysis found that Fas is one of the possible target genes of miR-23a, which was verified by luciferase reporter assay in vitro. Over-expression of miR-23a inhibits the induction of Fas by H2O2 in ARPE19 cells, and this effect was blocked by abrogation of miR-23a.
Conclusions: :
The protection of RPE cells against oxidative damage is afforded by miR-23a via regulation of Fas. Decrease miR-23a expression level in RPE cells may increase cell vulnerability to oxidative stress. Therefore, miR-23a may serve as novel therapeutic targets for AMD.
Keywords: retinal pigment epithelium • oxidation/oxidative or free radical damage • antioxidants