Regulation of retinal neovascularization in mice treated by recombinant PGC-1α protein

Abstract

To evaluate the regulatory effect of recombinant peroxisome-proliferatoractivatedreceptor- γ coactivator-1α (PGC-1α) on retinal neovascularization in mice. Forty 7-day-old C57BL/6J mice were randomly divided into 2 groups including a normal injection group and a normal control group. Additional 40 7-day-old C57BL/6J mice were randomly divided into 2 groups including a model injection group and a model control group, in which the mice were induced retinal neovascularization by hypoxia. Liposome with recombinant PGC-1α protein was injected into the vitreous of mice in the normal injection group and the model injection group at postnatal day 12 (P12). No injection was performed in the control group. Fluorescein angiography was used to assess the vascular pattern. The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections. PGC-1α levels in retina were measured by Western blot, and the vascular endothelial growth factor (VEGF) level in retina was measured by quantitative Real-time polymerase chain reaction and Western blot. Neovascular tuft was found in the normal injection group, but there was almost no neovascular tuft in the normal control group. Neovascular tuft and fluorescein leakage were increased in the model injection group compared with the model control group. The neovascular nuclei were increased both in the normal injection group and the model injection group compared with the control group (P<0.01). The expression of PGC-1α protein in retina was increased significantly both in the normal injection group and the model injection group as compared with the normal control group and the model control group, respectively (P<0.01). The expression of VEGF mRNA and protein in retina was increased significantly both in the normal injection group and the model injection group as compared with the normal control group and the model control group, respectively (P<0.01). PGC-1α can induce the formation of retinal neovascularization in the mice.