Effect of DNA damage marker γH2AX in the process of oxygen-induced retinal neovascularization

Abstract

Background Changes in the concentration of oxygen induced retinal neovascularization and DNA damage repair response.Overexpression of angiogenic factors is the main reason of angiogenesis.Whether the DNA damage related to retinal neovascularization is unclear. Objective This study was to study the role of DNA damage marker γH2AX in the process of retinal neovascularization of mouse. Methods Seventy-two 17-day-old C57BL/6J mice were randomly classified into normal control group, oxygen induced retinopathy (OIR) model group, OIR positive control group and OIR negative control group, 18 for each group.The retinal tissue were obtained from the 4 groups, the retinal patch immunofluorescence was used to observe and compare the area of retinal neovascularization and non-perfusion region and γH2AX expression of the four groups.The human umbilical vein endothelial cells (HUVECs) were classified into normal control group, hypoxia model control group, positive interference group and negative interference group.The cells from the 4 groups were obtained 12 hours after treatment, the expression of the γH2AX from different HUVECs groups were compared by immunofluorescence.Western blot was performed to detect the expressions of the γH2AX from different HUVECs groups. Results The retinal patch immunofluorescence showed that the OIR model was successfully established.The area of retinal neovascularization and the area of non-perfusion region among the 4 groups had statistical significances (F=437.62, 93.05, both at P<0.01). The area of retinal neovascularization and non-perfusion region in OIR model group and OIR negative control group was larger than that in the normal control group.The non-perfusion region was smaller in the OIR positive control group than that in the OIR model group and OIR negative control group (both at P<0.01). The appearance of the retinal γH2AX focus congestion was consistent with the area of neovascularization and non-perfusion in the 17-day-old mouse.The difference of γH2AX positive percentage in the four groups of HUVECs was statistically significant (F=64.97, P<0.01). The percentages of γH2AX positive cells in the hypoxia model control group and negative interference group were significantly higher than that in the normal control group (both at P<0.01). The percentage of γH2AX positive cells in the positive interference group was lower than that in the hypoxia model control group and negative interference group (both at P<0.01). Conclusions γH2AX is abundant in OIR neovascularization.Inhibiting the formation of γH2AX may reduce the OIR neovascularization. Key words: Retina; Neovascularization; Human umbilical vein endothelial cells; γH2AX