Objective  To observe the effect of visible light (white light, red light, blue light) on the expression of reactive oxygen species (ROS), 8-OHdG and hOGG1 in cultured human retinal pigment epithelial (RPE) cells. Methods  Cultured human RPE-19 cells (4th-6th generations) were divided into white light, red light, blue light and control group. The illumination was 600 Lux. The cells of experimental groups were exposed to white light or red light for 6, 12, 24 and 48 hours, and exposed to blue light for 1, 3, 6 and 12 hours, while cells of the control group were cultured in foil packaged dishes to avoid light. The levels of ROS expression were detected by 2 prime;,7-dichlorofluorescin-diacetate (DCFH-DA), the levels of 8-OHdG protein expression were observed by immunocytochemistry (ICC), and the levels of hOGG1 were measured by western blot. Results  Compared to the control group, the ROS expression in RPE cells were increased in white and red light group after 12, 24 and 48 hours and in blue light group after 1, 3, 6 and 12 hours (Fwhite light=11.611, Fred light=6.706, Fblue light=23.259; P＜0.05 ). Additionally, the ROS expression had a tendency to increase gradually along with exposure time. Compared to the control group, the 8-OHdG expression in RPE cells were increased significantly in both white and red light group after 12, 24 and 48 hours and in blue light group after 1, 3, 6 and 12 hours (Fwhite light=16.032,Fred light=6.378, Fblue light=19.484;P＜0.05). Additionally, the 8-OHdG expression in white and red light group were increased gradually with exposure time but decreased when exposure time was up to 48 hours, while that in blue light group was increased firstly though it started to decrease when exposure time was up to 6 hours. Compared to the control group, the hOGG1 expression in RPE cells were increased in white and red light group after 12, 24 and 48 hours and in blue light group after 6 and 12 hours (Fwhite light=15.121,Fred lig=21.041,Fblue light=12.479;P＜0.05). Conclusions  Exposure to white, red or blue light could induce ROS production and DNA oxidative damage in RPE cells in a time-dependent way. Exposure to visible light could switch on self-protection of RPE cells against DNA oxidative damage by up-regulating of the hOGG1 expression.

Citation： min FU,Jie LUAN,Zhonghong Zhang. Visible light induce oxidative damage to human retinal pigment epithelial cells. Chinese Journal of Ocular Fundus Diseases, 2011, 27(5): 466-470. doi: Copy