miR-106b在阿尔茨海默病中的作用机制

目的 探讨miR-106b在阿尔茨海默病(Alzheimer's disease,AD)发病中的作用.方法 取3月龄和6月龄APPswe/PSΔE9小鼠脑组织,进行microRNA芯片的检测;利用real-time PCR检测3、6、9月龄APPswe/PSΔE9小鼠脑组织中miR-106b的表达,对芯片检测结果进行验证;通过构建miR-106b稳定转染细胞系和miR-106b knockdown研究miR-106b与TGFBR2表达之间的关系; 构建TGFBR2 3'UTR-荧光素酶报告载体,验证miR-106b是否可以直接调控TGFBR2蛋白的表达;采用Western blot的方法检测APPswe/ΔPSΔE9小鼠和对照小鼠脑组织中TGFBR2蛋白的表达情况.结果 miR-106b在3月龄和6月龄AD模型小鼠脑组织中表达升高,在9月龄模型小鼠脑组织中表达降低;通过体外实验,我们发现miR-106b与TGFBR2蛋白的表达呈负相关;荧光素酶报告实验表明TGFBR2 3'UTR序列中包含miR-106b的结合位点;TGFBR2蛋白在3、6、9、12月龄AD模型小鼠脑组织中表达均降低.结论 miR-106b可能通过调控TGFBR2蛋白的表达影响TGF-β信号通路,从而参与AD的发病.

The role of miR-106b in Alzheimer's Disease

Objective To explore the role of miR-106b in Alzheimer＇s disease.Methods A microRNA array was used for the analysis of microRNA expression in the brain tissue of 3-month-old and 6-month-old APPswe /PSΔE9 mice.The results of microRNA array were validated by real time PCR.The expression correlation between miR-106b and TGFBR2 was detected through construction of miR-106b stably transfected SH-SY5Y cell line and miR-106b knockdown.To deter-mine whether miR-106b can directly regulate the expression of TGFBR2,The TGFBR2 3’UTR-luciferase reporter was con-structed and luciferase reporter assay was performed.The protein level of TGFBR2 in brain tissue from APPswe /PSΔE9 mice and control mice was detected by Western blot.Results The expression of miR-106b was a increased in 3-month-old and 6-month-old APPswe /PSΔE9 mice and decreased in 9-month-old AD mice compared with that in age-matched controls.The expression of miR-106b and TGFBR2 was negatively correlated in vitro.The luciferase assay showed that there was a binding site for miR-106b in 3’UTR of TGFBR2 and miR-106b can directly regulate the expression of TGFBR2.The protein level of TGFBR2 was downregulated in 3-to 12-month-old APPswe /PSΔE9 mice.Conclusions Our results suggest that miR-106b may contribute to the pathogenesis of Alzheimer＇s disease,at least in part by affecting the expression of TGFBR2.