目的:探讨高脂饮食诱导的C57 BL/6肥胖小鼠视网膜神经节细胞( RGCs)凋亡的机制。 方法:高脂饲料喂养19 wk后,小鼠分为肥胖抵抗( DIO-R)组和肥胖倾向( DIO)组,同时对照组( CON)小鼠给予基础饲料。 TUNEL法检测各组小鼠RGCs的凋亡情况,并应用激光共聚焦显微镜检测RGCs内钙离子的浓度。 结果:TUNEL法凋亡检测结果显示,DIO组小鼠视网膜神经节细胞层可见较多黄色着染的凋亡细胞,其凋亡指数为(6.7±1.2)%,显著高于对照组和DIO-R组(P<0.01, P<0.05);对照组和DIO-R组间比较无显著差异( P>0.05)。激光共聚焦结果显示,与对照组和DIO-R组比较,DIO组小鼠视网膜神经节细胞内Ca2+荧光染色明显增强,其荧光染色强度比值显著升高(均P<0.01);对照组和DIO-R组视网膜神经节细胞内Ca2+荧光染色强度无明显差异(P>0.05)。 结论:细胞内钙离子超载可能介导了肥胖型C57 BL/6小鼠视网膜神经节细胞的凋亡过程。
AIM:To investigate the mechanism of retinal ganglion cells (RGCs) apoptosis in the diet-induced obese C57BL/6 mice. METHODS: Mice were fed high-fat diet. After 19 weeks of feeding, the mice were divided into diet induced obesity-resistant ( DIO-R ) group and diet induced obesity ( DIO) group, while mice of the control ( CON) group were fed a basal diet at the same time. The apoptosis of RGCs was detected by TUNEL.Laser scanning confocal microscope was used to detect the intracellular calcium ion concentration. RESULTS: TUNEL staining showed apoptosis cells in ganglion cell layer ( GCL) in DIO group increased and the percentage of apoptotic cells was (6.7±1.2)%which was much higher than in CON and DIO-R groups ( P〈0.01, P〈0.05).There was no significant difference between CON group and DIO-R group ( P〉0.05 ).Laser scanning confocal microscope detection showed Ca2+ staining intensity of RGCs in DIO group increased and its staining intensity was significantly higher than in CON and DIO-R mice (P〈0.01,P〈0.01), whereas there was no significant difference between CON group and DIO-R group ( P〉0.05 ) . CONCLUSION:Intracellular calcium ion overload might be involved in the RGCs apoptosis in the diet-induced obese C57BL/6 mice.