白藜芦醇对阿尔茨海默病动物模型miRNA-106 b的影响

Effect of resveratrol on miRNA-106b in Alzheimer′s disease animal model

目的：探讨白藜芦醇对阿尔茨海默病（ AD）动物模型中miRNA-106b的影响。方法取3月龄健康昆明雄性小鼠50只，按照完全随机区组的抽样方法将其分为正常对照组、AD模型组和白藜芦醇高、中、低剂量组，每组10只。除正常对照组外，对其余各组均制作AD模型，连续30 d。从第31天起对对照及模型组每天灌胃双蒸水，其余组分别灌胃不同剂量白藜芦醇，连续60 d。给药结束后，观测小鼠行为记忆功能；检测各组小鼠大脑组织中淀粉样前体蛋白（ APP）、P62、载脂蛋白A1（ApoA1）、miRNA-106b、三磷酸腺苷结合盒转运子A1（ABCA1）表达变化；同时验证APP 3′UTR 序列中是否包含miRNA-106b的结合位点。结果通过跳台实验发现模型组小鼠记忆功能较对照组有不同程度下降，白藜芦醇干预组小鼠记忆功能较模型组均有不同程度提高（均P＜0.05）；AD小鼠大脑组织中APP表达（1.131±0.035）较正常对照组（0.652±0.026）高，而P62（0.412±0.022）、ApoA1（0.534±0.032）表达较低（均P＜0.05），高、中剂量白藜芦醇处理后可不同程度下调APP水平（0.733±0.018，0.929±0.019，F＝177.733）并升高P62（0.954±0.035，0.633±0.015，F＝434.5）、ApoA1（1.042±0.051，0.824±0.034，F＝286.582）水平（均P＜0.05）。 AD模型组动物脑组织miRNA-106b （0.464±0.314）及ABCA1（0.293±0.042）的表达较正常对照组miRNA-106b（1.064±0.032，F＝238.159）及ABCA1（0.781±0.027，F＝341.61）降低（均P＜0.05），高、中剂量白藜芦醇处理后miRNA-106b（0.843±0.034，0.601±0.012）及ABCA1（0.882±0.025，0.624±0.036）水平有不同程度升高（均P＜0.05）；荧光素酶报告载体实验表明APP 3′UTR序列中包含miRNA-106b的结合位点。结论 APP是miRNA-106b的靶基因之一，白藜芦醇可通过提高AD动物模型中miRNA-106b的表达并降低其靶基因APP的表达，同时可通过提高其他靶基因P62、ApoA1的水平来改善AD情况。这为AD的临床治疗提供了新的理论依据。

Objective To investigate the effect of resveratrol on miRNA-106b in Alzheimer′s disease （ AD ） animal model.Methods Fifty Kunming male mice were divided into five groups by completely randomized block sampling.The five groups included three dosage resveratrol groups , an AD model group and a control group.The AD models were established in one month prior to treatments. Subsequently, from the 31st day various doses of resveratrol were provided intragastricly for 60 days.Then the memory function was observed by the step-down test.Meanwhile, the varying expressions of APP , P62, ApoA1, miRNA-106b, ABCA1 were tested in each group to determine whether there is the binding site for miRNA-106b in APP 3′UTR sequence.Results Compared with the control group by step-down test, the memory function of the AD model group mice decreased in different degree , which in the drug treatment group was higher than that in the model group （P〈0.05）.Compared with the AD group, the expression of APP （1.131 ±0.035） in the drug treatment group was higher than that in the model group （0.652 ± 0.026）, while the P62 （0.412 ±0.022） and ApoA1 （0.534 ±0.032） were lower than the model group （ all P〈0.05 ）.High and medium dose groups of resveratrol treatment reduced varying degrees of APP （0.733 ±0.018,0.929 ±0.019,F=177.733） levels, and increased P62（0.954 ±0.035,0.633 ±0.015, F=434.5 ） and ApoA1 （ 1.042 ±0.051, 0.824 ±0.034, F=286.582 ） levels （ all P〈0.05 ）.The expression of miRNA-106b （0.464 ±0.313） and ABCA1（0.293 ±0.042） in the model group was lower than that in the control group （miRNA-106b 1.064 ±0.032, F=238.159; ABCA1 0.781 ±0.027,F=341.61;both P〈0.05）.The miRNA-106b （0.843 ±0.034, 0.601 ±0.012） and ABCA1 （0.882 ± 0.025, 0.624 ±0.036） levels in the high, medium dose resveratrol treatment groups increased to different extent （ both P〈0.05 ）.After the drug treatment , luciferase reporter vector experiments showed that the APP 3′UTR sequence contains the binding site of miRNA-106b.Conclusions APP is one of the target genes of miRNA-106b.Resveratrol is capable of improving AD by enhancing the expression of miRNA-106b and down-regulating the target genes including APP , P62 and ApoA1.This provides a new theoretical basis for the clinical treatment of AD.