动物造模,小鼠年龄相关性黄斑变性模型 z-bio 2021-10-09 696

　　Objective: To guide the establishment of a mouse age-related macular degeneration model combining chronic light and hydroquinone feeding, to observe the changes in its pathological characteristics, microstructure and retinal function, and to provide a model for the new pathogenesis and prevention of AMD.

　　Method: Twenty 4-month-old C57BL/6 mice were randomly divided into model group and normal group, with 10 mice in each group. The mice in the model group were fed a diet containing 8 g/(kg? bw) hydroquinone synthesized based on the basic purity and exposed to 2500 lx intensity light for 12 hours every day. The mice in the normal group were fed the same formula feed without hydroquinone under normal light for 3.5 months. Electroretinogram (ERG), optical microscope, and electron microscope were used to observe the changes in the function and structure of the retina of the two groups of mice. The apoptosis of retinal cells was observed by TUNEL method, and by immunofluorescence method. Detection of retinal and choroidal vascular endothelial growth factor (VEGF) and CD31, expression and distribution.

　　Results: ERG examination results showed that the retinal function of the model group was lower than that of the normal group; under light microscope, the structure of the retinal pigment epithelium and Bruch's membrane in the model group showed atrophy-like changes. , The number of photoreceptor cells in the model group was (164.67±34.37), the normal group was (243.33±15.23), and the number of photoreceptor cells in the model group was significantly less than that in the model group. For the normal group, the difference was statistically significant (t=-9.77, Pu003c0.05); transmission electron microscopy showed that the retinal photoreceptor cell membrane disc structure in the model group was loose. Deformed and partially broken. The number of retinal pigment epithelial cells becomes shorter, Bruch's membrane becomes irregularly thick, the outer collagen layer is deposited in layers, and endothelial cells protrude into Bruch's membrane. TUNEL results showed that there were almost no apoptotic cells in the normal group, and a large number of apoptotic cells appeared in the retinal pigment epithelial layer and photoreceptor layer of the model group, and the photoreceptor apoptotic rate was (43±2.73). ), and the difference between the two groups was statistically significant (Pu003c0.01). The results of immunofluorescence examination showed that the expression of VEGF in the outer plexiform layer and nerve fiber layer of the normal group was weakly positive. In addition to the cells in the model group, the RPE cell layer also showed strong positive staining. There was no obvious CD31 positive staining in the cells of each layer of the retina in the normal group. The expression of CD31 in the RPE cell layer of the model group was strong, suggesting angiogenesis in the RPE layer.

　　Conclusion: The pathogenesis and characteristics of mice on long-term light combined with hydroquinone diet are very similar to human AMD, which can provide a reliable animal model for further research on the pathogenesis and prevention of AMD.