动物造模,氧诱导视网膜病变小鼠模型 z-bio 2022-08-17 323

　　Objective To investigate the mechanism of microRNA (miR)-20a-5p regulating vascular endothelial growth factor (VEGF) pathway in mice with oxygen-induced retinopathy (OIR).

　　Methods The experiment was divided into normal group, model group, hyperoxia control group, and miR-20a-5p high expression group, with 24 mice in each group. Except for the normal group, the mice in the other groups were placed in an oxygen concentration (75.00±2.00)% oxygen box to establish the OIR mouse model on the 7th day after birth, and then placed in normoxia for 5 days in a continuous hyperoxia environment. rearing. One day before the end of the hyperoxia environment, 1 μL of phosphate-buffered saline (PBS) was injected into the vitreous cavity of the hyperoxia control group, and 1 μL of miR-20a-5p agonist (miR-20a-5p) was injected into the vitreous cavity of the miR-20a-5p high expression group 20a-5p agomir) (1 μmol/L), the model group did not do any treatment. The normal group was kept in the air and raised normally. After the end of hyperoxia, the mice in each group were reared in normal air for another 5 days for the experiment. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expressions of miR-20a-5p, VEGF, vascular endothelial growth factor receptor (VEGFR)-1, and VEGFR-2 in retinal tissue; retinal slices were used to observe retinal blood vessels; hematoxylin- Eosin (HE) staining was used to count the nuclei of retinal neovascular endothelial cells; immunohistochemistry was used to detect VEGF-positive cells in retinal tissue.

　　Results On the 17th day after birth, in the model group and the hyperoxia control group, the radial large blood vessels from the optic disc to the periphery were circuitous and irregularly expanded, and a large number of new blood vessels appeared, and the structure and distribution of the new blood vessels were disordered, and the peripheral capillary network was blocked; miR-20a Compared with the model group and the hyperoxia control group, in the -5p high expression group, the radial large blood vessels emanating from the optic disc to the periphery on the 17th day of birth were less obvious, the irregular expansion of blood vessels was alleviated, and the new blood vessels were significantly reduced. Compared with the normal group, the level of miR-20a-5p in the retina tissue of the model group and the hyperoxia control group decreased (P<0.05), the number of retinal vascular endothelial cell nuclei, the percentage of VEGF protein positive area, VEGF, VEGFR- 1. The expression level of VEGFR-2 mRNA was increased (P<0.05); compared with the model group and the hyperoxia control group, the level of miR-20a-5p in the retina tissue of the miR-20a-5p high expression group was increased (P<0.05). P < 0. 05), the number of retinal vascular endothelial cell nuclei, the percentage of positive area of VEGF protein, and the expression levels of VEGF, VEGFR-1 and VEGFR-2 mRNA in retinal tissue decreased (P < 0.05).

　　Conclusion Elevating miR-20a-5p can inhibit the VEGF pathway to reduce retinal angiogenesis in OIR mice, and achieve retinal protection in OIR mice.