脑缺血后大鼠室管膜下区miR-34a及其相关靶基因Sirt1、Nrf2的动态表达及意义  

Dynamic expressions of miR-34a and related target genes sirtuin 1 and nuclear factor-E2-related factor 2 and their significances in subependymal zone of rats with cerebral ischemia

作　　者：廖伟[1] 张雷英[2] 刘鹏[1] 邹连生[1] 娄建云[1] 杨少春[1] Liao Wei;Zhang Leiying;Liu Peng;Zou Liansheng;Lou Jianyun;Yang Shaochun(Department of Neurosurgery, First Affiliated Hospital of Gannan Medical College, Ganzhou 341000, China;Department of Obstetrics and Gynecology, First Affiliated Hospital of Gannan Medical College, Ganzhou 341000, China)

机构地区：[1]赣南医学院第一附属医院神经外科,赣州341000 [2]赣南医学院第一附属医院妇产科,赣州341000

出　　处：《中华神经医学杂志》2019年第5期447-452,共6页Chinese Journal of Neuromedicine

基　　金：江西省卫生厅科技计划项目(20155415);赣州市指导性科技计划项目(GZ2017ZSF039).

摘　　要：目的观察大鼠脑缺血后室管膜下区微小RNA 34a(miR-34a)及其相关靶基因沉默信息调节因子2相关酶1(Sirt1)、核因子E2相关因子2(Nrf2)的表达变化,探讨miR-34a对脑缺血后内源性神经干细胞增殖的影响。方法40只SD大鼠按随机数字表法分为对照组、脑缺血1 d组、脑缺血3 d组、脑缺血7 d组,每组10只。后3组采用线栓法制备成大脑中动脉栓塞局灶性脑缺血模型,并分别于造模1、3、7 d后取室管膜下区进行实验。采用免疫荧光染色检测各组大鼠神经干细胞标志物巢蛋白(nestin)的表达,采用荧光定量PCR检测miR-34a、Sirt1、Nrf2 mRNA的表达水平,采用Western blotting检测Sirt1、Nrf2蛋白的表达水平。结果(1)脑缺血1 d组、脑缺血3 d组、脑缺血7 d组nestin阳性细胞计数逐渐增加[(2.013±0.526、4.821±1.154、6.394±1.027)个/视野],差异均有统计学意义(P<0.05)。(2)脑缺血1 d组、脑缺血3 d组、脑缺血7 d组miR-34a mRNA的表达水平逐渐增高(0.295±0.145、0.701±0.075、1.136±0.018),Sirt1 mRNA的表达水平逐渐下降(0.835±0.024、0.620±0.153、0.278±0.110),Nrf2 mRNA的表达水平逐渐下降(1.032±0.256、0.833±0.187、0.630±0.123),Sirt1蛋白的表达水平逐渐下降(0.832±0.018、0.731±0.156、0.454±0.132),Nrf2蛋白的表达水平逐渐下降(1.003±0.133、0.813±0.111、0.671±0.071),差异均有统计学意义(P<0.05)。(3)相关性分析显示,脑缺血后nestin阳性细胞计数与miR-34a mRNA的表达水平呈正相关关系(r=0.887,P=0.003),与Sirt1 mRNA和蛋白的表达水平呈负相关关系(r=-0.746,P=0.005;r=-0.521,P=0.013),与Nrf2 mRNA和蛋白的表达水平呈负相关关系(r=-0.344,P=0.025;r=-0.863,P=0.000)。结论MiR-34a有可能通过Sirt1/Nrf2途径调控脑缺血后内源性神经干细胞的增殖。Objective To observe the expression changes of miR-34a and its related target genes sirtuin 1 (Sirt1) and nuclear factor-E2-related factor 2 (Nrf2) in subependymal zone (SVZ) of rats after cerebral ischemia, and to explore the effect of miR-34a on proliferation of endogenous neural stem cells (NSCs) after cerebral ischemia. Methods Forty SD rats were randomly divided into control group, cerebral ischemia one d group, cerebral ischemia three d group and cerebral ischemia 7 d group (n=10). Middle cerebral artery occlusion models were established by thread embolization in the latter three groups, and the SVZs were taken one, three and 7 d after model making, respectively. Immunofluorescence staining was used to detect the expression of nestin, real-time PCR was used to detect the mRNA expressions of miR-34a, Sirt1 and Nrf2, and Western blotting was used to detect the protein expressions of Sirt1 and Nrf2. Results (1) In SVZs of cerebral ischemia one d group, cerebral ischemia three d group and cerebral ischemia 7 d group, the number of nestin positive cells increased gradually ([2.013±0.526],[4.821±1.154], and [6.394±1.027]) cells/filed, with statistical differences (P< 0.05).(2) In SVZs of cerebral ischemia one d group, cerebral ischemia three d group and cerebral ischemia 7 d group, the expression levels of miR-34a mRNA increased gradually (0.295±0.145, 0.701±0.075, and 1.136±0.018), the Sirt1 mRNA expression levels showed a downward trend (0.835±0.024, 0.620±0.133, and 0.278±0.110), the Nrf2 mRNA expression levels obviously decreased (1.032±0.256, 0.833±0.187, and 0.630±0.123), the Sirt1 protein expression levels showed a downward trend (0.832±0.018, 0.731±0.156, and 0.454±0.132), and the Nrf2 protein expression levels obviously decreased (1.003±0.133, 0.813±0.111, and 0.671±0.071), with statistically significant differences (P<0.05).(3) Statistical correlation analysis showed that the number of nestin positive cells was positively correlated with miR-34a mRNA expression level and negatively cor

关 键 词：脑缺血 微小RNA 34a 沉默信息调节因子2相关酶1 核因子E2相关因子2 神经干细胞 细胞增殖 

分 类 号：R743.3[医药卫生—神经病学与精神病学]