有氧运动对阿尔兹海默症小鼠Notch信号通路甲基化的影响

Effects of Aerobic Exercise on Methylation of Notch Signaling Pathway in Alzheimer’s Disease Mice

目的:观察有氧运动后阿尔茨海默病(AD)小鼠大脑Notch信号通路相关因子表达及甲基化水平的变化,探究有氧运动如何影响AD小鼠Notch信号通路。方法:将3月龄APP/PS1双转基因AD小鼠随机分为两组:对照组(ADC组),运动组(ADE组),每组20只。对照组不进行运动,运动组进行每周5天、每天30min、持续5个月的跑台运动干预。干预5个月后取小鼠脑组织,采用Real-time PCR、免疫荧光及Western Blot技术分别检测海马组织Notch1、Hes1及神经元素2(Neurogenin2,Ngn2)蛋白和mRNA的表达,采用甲基化特异性PCR检测海马组织Notch1、Hes1、Ngn2的甲基化水平。结果:与ADC组相比,ADE组小鼠大脑海马组织Notch1、Hes1蛋白和mRNA表达显著降低(P<0.01),海马DG区Notch1阳性细胞数量、Hes1阳性细胞数量显著降低(P<0.01),Hes1免疫阳性产物荧光强度显著降低(P<0.05);而ADE组小鼠海马Ngn2蛋白和mRNA表达显著升高(P<0.05),海马DG区Ngn2阳性细胞数量显著升高(P<0.01),Ngn2免疫阳性产物荧光强度显著升高(P<0.05)。通过甲基化特异性PCR检测发现,与ADC组相比,ADE组小鼠海马Notch1及Hes1的甲基化率显著增加,Ngn2的甲基化率则显著减少(P<0.01)。结论:长期有氧运动后AD小鼠海马Notch1及Hes1的甲基化率显著增加,而其Ngn2的甲基化率则显著减少,而这可能是长期有氧运动可以显著下调AD小鼠海马Notch1、Hes1的表达,以及显著上调Ngn2表达的原因之一。

ObjectiveTo observe the expression of Notch signaling pathway-related factors and their methylation in the brain of Alzheimer’s disease(AD)mice after aerobic exercise,and explore how aerobic exercise affects their Notch signaling pathway.MethodsForty 3-month-old APP/PS1 double transgenic AD mice were randomly divided into a control group(ADC) and an exercise group(ADE),each of 20. The control group did not exercise,while the exercise group underwent 30-minaerobic exercise5 days a week for 5 months. After the intervention,their brain tissue was taken and the protein and mRNA expressions of Notch1,Hes1 and Neurogenin2(Ngn2) were detected using the real-time polymerase chain reaction(PCR),immunofluorescence and Western blotting,respectively. The methylationspecific PCR was employed to detect their methylation.ResultsCompared with ADC group,a significant decrease was observed in the average protein and mRNA expression of Notch1 and Hes1(P<0.01),the number of Notch1 and Hes1 positive cells in the hippocampal DG region(P<0.01),as well as the fluorescence intensity of Hes1 immunopositive products of ADE group(P<0.05),but a significant increase was found in the average protein and mRNA expression of Ngn2(P<0.05),the number of Ngn2 positive cells in the DG region of the hippocampus(P<0.01),and the fluorescence intensity of Ngn2 immunopositive products(P<0.05) of the latter group. The methylation specific PCR detection showed that the methylation rate of Notch1 and Hes1 in the hippocampus of ADE group increased significantly compared with ADC group,while that of Ngn2 decreased significantly(P<0.01).Conclusions After long-term aerobic exercise,the methylation rate of Notch1 and Hes1 in the hippocampus of AD mice increases significantly,while that of Ngn2 decreases significantly. It may be one of the reasons for the long-term aerobic exercise significantly down-regulating the expressions of Notch1 and Hes1,and up-regulating that of Ngn2 in AD mice.