微小RNA let-7b通过结合STAT3抑制颞叶癫痫大鼠海马胶质细胞的活化  

MicroRNA let-7b inhibits hippocampal glial cell activation by targeting STAT3 in a rat model of temporal lobe epilepsy

作　　者：刘云鹏 孟凡刚[1] 韩春雷[1] 赵学敏[1] 王开亮[1] 张鑫[1] 张建国[2] Liu Yunpeng;Meng Fan′gang;Han Cunlei;Zhao Xuemin;Wang Kailiang;Zhang Xin;Zhang Jianguo(Beijing Neurosurgical Institute, Capital Medical University, Beijing 100070, China;Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China)

机构地区：[1]首都医科大学,北京市神经外科研究所,100070 [2]首都医科大学附属北京天坛医院神经外科,100070

出　　处：《中华神经外科杂志》2019年第4期400-406,共7页Chinese Journal of Neurosurgery

基　　金：国家自然科学基金(81471315)。

摘　　要：目的探讨let-7b和STAT3在癫痫发生过程中的表达情况以及let-7b结合STAT3在颞叶癫痫大鼠海马胶质细胞活化中的作用。方法采用立体定向海人酸注射建立癫痫大鼠模型(模型组,40只)。假手术组注射等量的生理盐水(10只)。采用腺相关病毒载体制备let-7b过表达的大鼠。以实时荧光定量PCR检测let-7b的表达。采用双荧光素酶报告基因实验鉴定let-7b与其靶基因STAT3的靶向关系。采用免疫荧光实验检测星形胶质细胞以及小胶质细胞的活化。以免疫印迹法检测Janus激酶(JAK)/信号转导与转录激活因子(STAT)信号通路以及相关炎症因子的表达。结果与假手术组大鼠相比,let-7b在模型组大鼠癫痫发生的潜伏期(造模后3d和7d)的表达降低(均P<0.01),而STAT3在大鼠癫痫发生潜伏期的表达升高(均P<0.001)。双荧光素酶报告基因实验结果表明,let-7b可结合STAT3并抑制其表达(P<0.05)。免疫荧光实验结果表明,let-7b过表达可抑制潜伏期癫痫大鼠海马CA3区的星形胶质细胞和小胶质细胞的活化(均P<0.01)。免疫印迹法实验表明,let-7b过表达可抑制p-Stat3及其下游转录因子c-Myc的表达(均P<0.001)以及相关炎症因子IL-1β、IL-6和TNF-α的释放(均P<0.01)。结论Let-7b可通过结合靶基因STAT3抑制癫痫大鼠海马胶质细胞的活化、增生。Objective To detect the expression of let-7b and STAT3 during epileptogenesis and to explore the effect of let-7b on activation of hippocampal glial cell by targeting STAT3 using a rat model of temporal lobe epilepsy. Methods A rat model of status epilepticus was induced by intra-amygdala kainic acid(KA) injection (n=40). Sham-operated controls received equal-volume intraperitoneal saline injection (n=10). The adeno-associated virus vector was used to construct the let-7b overexpression rats. The expression of let-7b was examined by qPCR. The dual luciferase reporter assay was used to confirm the relationship between let-7b and STAT3. Astrocyte and microglia activation were assessed by immunofluorescence. Expression of proinflammatory cytokines and components of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were evaluated with Western blot. Results Let-7b was decreased (both P<0.01) while its target gene STAT3 was increased (both P<0.001) in the latent period of epilepsy (at 3 d and 7 d post KA injection) compared with sham-operated controls rats. The dual luciferase reporter assay demonstrated that let-7b inhibited the expression of STAT3 (P<0.05). The immunofluorescence analysis showed that let-7b overexpression inhibited the activation of astrocytes and microglia and the release of inflammatory factors in CA3 subfield of the hippocampus of epileptic rats (both P<0.01). Western blot analysis showed that let-7b overexpression inhibited the expression of p-Stat3 and its downstream effector c-Myc(both P<0.001) and the release of inflammatory factors (IL-1β, IL-6 and TNF-α)(all P<0.01). Conclusion Let-7b could lead to suppression of glial cell activation and proliferation of the hippocampus of epileptic rats by targeting STAT3.

关 键 词：癫痫 颍叶 神经胶质增生 微小RNA let-7b STAT3转录因子 大鼠 

分 类 号：R742.1[医药卫生—神经病学与精神病学]