瑞香素对阿尔茨海默病模型小鼠自噬的影响

Effect of Daphnetin on Autophagy in Alzheimer's Disease Model Mice

关键词:  阿尔茨海默病  瑞香素  自噬

Key words:  Alzheimer's disease  daphnetin  autophagy

摘要:

目的 探讨瑞香素对阿尔茨海默病(Alzheimer’s disease，AD)自噬的影响以及对AD神经保护的作用机制。方法 选用APP/PS1双转基因模型小鼠，3个月龄后开始灌胃给药。药物治疗3个月后，通过Morris水迷宫试验观察瑞香素对AD模型小鼠空间探索和记忆能力的影响；采用ELISA试剂盒检测AD模型小鼠海马脑组织Aβ_1-40、Aβ_1-42水平；利用Western blotting检测瑞香素对AD模型小鼠海马组织微管相关蛋白轻链3Ⅱ(microtubule-associated proteins light chain 3 Ⅱ，LC3-Ⅱ)、beclin-1及p62表达水平的影响。结果 Morris水迷宫试验显示，APP/PS1双转基因模型小鼠逃避潜伏期较对照组明显延长，原象限停留时间明显缩短；瑞香素组小鼠逃避潜伏期较模型组明显缩短，原象限停留时间明显延长。与对照组比较，APP/PS1双转基因模型小鼠脑组织中Aβ水平增多，而瑞香素减少模型小鼠Aβ水平；Western blotting结果显示AD模型小鼠海马区LC3-Ⅱ及beclin-1显著降低，p62显著增加，而瑞香素可上调APP/PS1双转基因模型小鼠LC3-Ⅱ及beclin-1表达并抑制p62的蛋白表达。结论 瑞香素通过上调LC3Ⅱ和beclin-1自噬相关蛋白增强自噬，改善AD模型小鼠的学习记忆功能。

Abstract:

OBJECTIVE To explore the effect of daphnetin on autophagy in Alzheimer's disease(AD) and its mechanism of neuroprotection in AD. METHODS Drugs were administered to 3-month old APP/PS1 double transgenic mice. After 3 months of drug treatment, the effect of daphnetin on spatial exploration and memory in AD model mice was observed by Morris water maze test; ELISA kits were used to detect the levels of Aβ_1-40 and Aβ_1-42 in the hippocampus of AD model mice. Western blotting was used to detect the effect of daphnetin on microtubule-associated protein light chain 3 Ⅱ(LC3-Ⅱ), beclin-1 and the effect of p62 expression level. RESULTS Morris water maze test showed that the escape latency of APP/PS1 double transgenic mice was significantly longer than that of the control group, and the residence time of the original quadrant was significantly shorter. The escape latency of daphnetin group was significantly shorter and the residence time of the original quadrant was prolonged compared with the model group. Compared with the control group, the levels of Aβ in the brain of APP/PS1 double transgenic mice were increased, and the levels of Aβ in daphnetin group were significantly decreased. Western blotting results showed that LC3-Ⅱ and beclin-1 in hippocampus of AD model mice decreased significantly, daphnetin increased the expression of LC3-Ⅱ and beclin-1 and inhibited the protein expression of p62. CONCLUSION Daphnetin enhances autophagy by up regulating LC3-Ⅱ and beclin-1 proteins and improves the learning and memory function of AD mice.