膳食诱导的肥胖型C57BL/6小鼠视网膜神经节细胞凋亡的机制

目的：探讨高脂饮食诱导的C57BL/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19wk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C57BL/6小鼠视网膜神经节细胞的凋亡过程。

Mechanism of retinal ganglion cells apoptosis in the diet-induced obese C57BL/6 mice

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.