动物造模 z-bio 2021-07-28 963

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

　　Method: The experiment is divided into normal group, model group, hyperoxia control group, miR-20a-5p high expression group, 24 mice in each group. Except for the normal group, the mice in the other groups were placed in an oxygen box with an oxygen concentration of (75.00 ± 2.00). The OIR mouse model was established on the 7th day after birth. The mice maintained a normal oxygen state for 5 consecutive days. All drooling. High oxygen environment. One day before the end of the hyperoxia environment, the hyperoxia control group was injected with 1 μL of phosphate buffered saline (PBS) into the vitreous cavity, and the miR-20a-5p high expression group was injected with 1 μL of miR-20a-5p. I injected it. An agonist (miR-20a-5pagomir) (1 μmol/L) was placed in the vitreous cavity, and the model group did not do any treatment. The normal group stays in the air and remains normal. After the end of hyperoxia, each group of mice was raised in normal air for another 5 days for experiment. Real-time fluorescent quantitative PCR (qRT-PCR) was used to detect the expression of miR-20a-5p, VEGF, vascular endothelial growth factor receptor (VEGFR)-1, and VEGFR-2 in retinal tissues. The morphology of retinal blood vessels; hematoxylin-eosin (HE) staining is used to count the nuclei of retinal neovascular endothelial cells, and immunohistochemistry is used to detect VEGF-positive cells in retinal tissues.

　　Results: In the model group and the hyperoxic control group, on the 17th day after birth, the radial great blood vessels expanded irregularly from the optic disc to the periphery, and many new blood vessels appeared, their structure and distribution were relatively new, the blood vessels appeared disordered, and the peripheral capillaries Net occlusion; compared with the miR model group and the hyperoxia control group, the -20a-5p high expression group has no obvious detour from the optic disc to the radial great vessels. paddy. At 17 days of age, irregular expansion of blood vessels is reduced, and angiogenesis is significantly reduced. Compared with the normal group, the level of miR-20a-5p in the network tissue of the model group and the hyperoxia control group decreased (Pu003c0.05), and the number of retinal vascular endothelial cell nuclei and the positive area of VEGF protein decreased. Compared with the model group and the hyperoxia control group, the percentage of VEGF, VEGFR-1 and the expression level of VEGF VEGFR-2 mRNA in retinal tissue increased the level of miR-20a-5p in retinal tissue. P \u003c 0.05). The miR-20a-5p high expression group increased (Pu003c0.05), the number of retinal vascular endothelial cell nuclei, the proportion of VEGF protein-positive areas increased, and the expression levels of VEGF, VEGFR-1, and VEGFR-2 mRNA decreased (Pu003c0.05).

　　Conclusion: Increasing miR-20a-5p inhibits the VEGF pathway, reduces retinal angiogenesis in OIR mice, and protects the retina of OIR mice.