电针激活大脑中动脉闭塞大鼠miRNA调控NF-κB信号通路的机制研究

关键词：电针  脑缺血  微小RNA-9a  NF-κB信号通路

Keywords:electroacupuncture  cerebral ischemia  miR-9a  NF-κB

摘要：

      摘要 目的：探讨电针通过NF-κB信号通路治疗局灶性脑缺血再灌注损伤大鼠所产生的抗炎作用的miRNA调控机制。 方法：将54只SD大鼠随机分为假手术组、模型组及电针组，以大脑中动脉闭塞（middle cerebral artery occlusion, MCAO）法建立大鼠局灶性脑缺血再灌注模型。利用TargetScan预测miR-9a的靶基因，并用双荧光素酶报告载体验证。运用HE染色及TTC染色观察脑缺血后大鼠皮质炎症反应及梗死面积；应用蛋白免疫印迹法和实时PCR检测缺血侧皮质组织中NF-κB，TNF-α及miR-9a的表达情况。 结果：电针曲池、足三里穴可明显改善MCAO大鼠的神经功能缺损症状，降低脑梗死范围，炎症反应明显缓解。可以提高缺血侧皮质miR-9a的表达（P＜0.05），降低炎症因子NF-κB，TNF-α的表达（P＜0.05）。 结论：电针调控NF-κB信号通路，抑制炎症因子分泌，来实现对脑缺血的治疗作用的机制可能与促进miR-9a的表达上调相关。

Abstract:

      Abstract Objective: To investigate the possible anti-inflammatory mechanism of electroacupuncture (EA) via regulating NF-κB pathway in rats with focal cerebral ischemia-reperfusion (I/R). Method: Fifty-four male adult SD rats were randomly divided into the sham operation control group (SC group), the ischemia model group (IC group) and the electroacupuncture group (EA group). Middle cerebral artery occlusion (MCAO) was performed to establish the focal cerebral ischemia- reperfusion injury model. The potential target genes of miR-9a was predicted and identified by dualluciferase reporter assay. TTC stain was used to examine the volume of infarction, HE staining was observed inflammatory responses. Western blot analysis was employed to determine the expression of NF-κB, TNF-α in ischemic regions. Quantitative RT-PCR was used to detect miR-9a. Result: Electroacupuncture at Quchi (LI11) and Zusanli (ST36) acupoints significantly improved the ischemia-associated scores of neurological deficits, reduced cerebral infarction and improved inflammatory responses. The expression of miR-9a significantly increased and NF-κB, TNF-α decreased in the EA group compared with those of IC group (P＜0.05). Conclusion: Electroacupuncture exerts a neuroprotective function in cerebral ischemia through inhibition of NF-κB-mediated inflammation, and the mechanism may be associated with the upregulation of miR-9a.