高脂诱导肥胖小鼠视网膜变性的形态学改变

Morphological changes of retinal degeneration in obese mice fed with high-fat diet

目的探讨高脂饮食建立的C57BL/6小鼠肥胖模型的视网膜变性的超微结构改变。方法高脂饲料喂养19周后,小鼠分为肥胖抵抗(DIO-R)组和肥胖倾向(DIO)组,同时对照组小鼠给予基础饲料喂养。应用光镜,透射电镜及TUNEL法检测三组小鼠视网膜超微结构的改变及凋亡情况。结果与对照组及DIO-R组比较,DIO组小鼠视网膜及外核层(ONL)变薄,感光细胞出现凋亡及坏死,其外段视盘排列紊乱,视盘膜溶解、断裂,视网膜神经节细胞体积变小,细胞质分布紊乱,核染色质固缩。TUNEL法检测结果显示,在ONL层可见较多的凋亡细胞体,DIO组细胞凋亡率显著高于对照组和DIO-R组。结论高脂诱导的肥胖可能导致C57BL/6小鼠视网膜变性及细胞凋亡。

Objective To investigate the ultrostructural changes of retina caused by high-fat diet induced obesity in C57BL/6 mice. Methods Mice were fed a high-fat diet for 19 weeks and then divided into diet induced obesity-resistant （DIO-R） group and diet induced obesity （DIO） group, mice in control group were fed with a basal diet at the same time. The retinal ultrostructural changes were detected by light and transmission electron microscope, the cellular apoptosis was detected by TUNEL. Results The retinal and outer nuclear layer（ONL） thicknesses were thinner in DIO group than in control and DIO-R groups. The photo- receptors showed characteristic features of apoptosis and necrosis, the photoreceptor disk membranes were disordered and some of them were dissolved and fractured in DIO group. The retinal ganglion cells in DIO group showed smaller and condensation of nuclear chromatin and increased electron density of the cytoplasm. TUNEL staining showed that the percentage of apoptosis cells in ONL increased in DIO group than in control and DIO-R groups. Conclusion High-fat diet induced obesity may cause ultrastructural changes of retinal degeneration and cellular apotosis in C57BL/6 mice.