基于PI3K/AKT信号通路探讨针刺对脑缺血再灌注损伤大鼠线粒体自噬作用的机制研究

目的 观察针刺疗法对脑缺血再灌注损伤(Cerebral ischemia-reperfusion injury,CIRI)大鼠脑组织线粒体自噬的影响,并探究其对脑组织保护作用的机制。方法 将SD大鼠随机分为假手术组、CIRI组、非穴位针刺组、针刺穴位组,每组10只。采用改良线栓法构建脑缺血再灌注大鼠模型,针刺穴位组针刺“大椎”、“人中”、“百会”三穴,非穴位针刺组针刺穴位左侧旁开0.3cm处,假手术组和CIRI组不行针刺。在脑缺血再灌注后24h用Zea Longa评分法对大鼠进行神经功能评分,取大鼠脑组织TTC染色法检测梗死体积,JC-1法检测大鼠脑组织线粒体膜电位变化。通过Western blot检测自噬相关蛋白及PI3K-AKT信号通路相关蛋白表达。结果 相较于假手术组,CIRI组大鼠神经功能评分显著升高,脑组织线粒体自噬相关蛋白LC3II、BNIP3水平显著升高,p62水平降低,自噬水平增强,线粒体膜电位降低,同时PI3K-AKT信号通路相关蛋白磷酸化水平显著降低;相较于非穴位针刺组,针刺穴位对脑缺血再灌注大鼠脑组织起保护作用,表现为大鼠神经功能缺损评分、脑梗死体积以及脑半球肿胀显著降低(P＜0.05),线粒体膜电位升高,自噬水平降低,同时PI3K-AKT信号通路相关蛋白p-PI3K、p-AKT和p-mTOR水平显著升高。结论 针刺疗法可能通过激活PI3K/AKT信号通路抑制线粒体自噬,从而实现对脑缺血再灌注损伤大鼠的脑保护作用。

To explore the mechanism of mitochondrial autophagy in rats with cerebral ischemia-reperfusion injury by acupuncture based on PI3K/AKT signaling pathway Zhang Lian,Li Lei,Zhao Jing

Objective To observe the effect of acupuncture on mitochondria autophagy in brain tissue of rats with cerebral ischemia-reperfusion injury (CIRI), and explore the mechanism of its protective effect on brain tissue. Methods SD rats were randomly divided into sham operation group, CIRI group, non-point acupuncture group and point acupuncture group, with 10 rats in each group. The model of cerebral ischemia-reperfusion rats was constructed by the modified thread embolism method. The acupuncture point group was acupunctured at the three points "Dazhui Renzhong Baihui Zea Longa score, infarct volume was detected by TTC staining, mitochondrial membrane potential changes in brain tissue were detected by JC-1 method. The expressions of autophagy related proteins and PI3K-AKT signaling pathway were detected by Western blot. Results Compared with sham operation group, the neural function scores of CIRI group were significantly increased, the levels of autophagy related proteins LC3II and BNIP3 in brain tissue were significantly increased, the levels of p62 were decreased, autophagy was enhanced, mitochondrial membrane potential was decreased, and the phosphorylation levels of PI3K-AKT signaling pathway related proteins were significantly decreased. Compared with the non-acupoint acupuncture group, acupoint acupuncture had a protective effect on the brain tissue of cerebral ischemia reperfusion rats, which showed that the neurological deficit score, cerebral infarction volume and cerebral hemisphere swelling of rats were significantly decreased (P < 0.05), mitochondrial membrane potential was increased, and autophagy level was decreased. Meanwhile, the levels of PI3K-AKT signaling pathway related proteins p-PI3K, p-AKT and p-mTOR were significantly increased. Conclusion Acupuncture may inhibit mitochondrial autophagy by activating PI3K/AKT signaling pathway, thus achieving brain protection in rats with cerebral ischemia-reperfusion injury.