Oxidative Damage induced by UV in Cultured Retinal Pigment Epithelial Cells

Purpose: The death of retinal pigment epithelial(RPE) cells plays an important role in the development of age-related macular degeneration. We studied whether ultraviolet could induce apoptotic cell death and the increase of reactive oxygen intermediates (ROI) in the RPE cells. 2 Methods: Cultured human RPE cells were exposed to doses of between 0 and 80 mJ/ UVB as an attached monolayer. The number of viable cells was assessed by trypan blue assay. The apoptosis was determined by flow cytometry using annexin V and propidium iodide (PI). Intracellular ROI was measured using DCFH-DA. Results: UVB-exposed cells showed a dose-dependent cell death. The number of cells decreased in 2030% at the dose of 40 mJ/ UVB 24 hours after UVB exposure. The proportion of annexin V positive cells and intracellular ROI increased after UVB exposure. Conclusions: These results suggest that UV-induced oxidative damage may be one of the important mechanisms of RPE cell death.