Objective: To observe the effect of acupuncture on the cerebral infarct volume and expressions of Beclin1, microtubule-associated protein 1 light chain 3 (LC3) and p62 proteins related to cell autophagy in rats with cerebral ischemia (CI), so as to explore its mechanisms underlying improvement of CI injury.
Methods: Male SD rats were randomized into 3 groups: sham operation, model and acupuncture which were further divided into 4 subgroups according to different ischemia time-points: 3, 6, 12 and 24 h (n=7 in each subgroup). The CI model was established by occlusion of the middle cerebral artery (MCAO) with surgical suture-embolus. For rats of the acupuncture group, acupuncture was applied to "Shuigou" (GV26) and bilateral "Neiguan" (PC6), and twirled for 1-3 min every time, 10 times altogether, and kept for 30 min. The neurological deficit score accoding to Longa's method was used for assessing the neurological function. The CI volume was measured after 2, 3, 5-triphenyltetrazolium chloride staining. The expression levels of autophagy-related proteins Beclin1，LC3 and p62 in the brain tissue were detected using Western blot.
Results: Compared with those of the sham operation group，the neurological deficit scores at 2, 3, 6， 12 and 24 h after CI, and the infarct volumes, the expression levels of Beclin1 and the ratios of LC3-Ⅱ/LC3-Ⅰ at 3, 6, 12 and 24 h were considerably increased (P<0.01, P<0.05), and the expression levels of p62 at 3, 6, 12 and 24 h were significantly decreased (P<0.01) in the model group. Relevant to the model group, acupuncture stimulation of GV26 and PC6 induced an obvious decrease in the neurological deficit scores at 6, 12 and 24 h, CI volumes at 3, 6, 12 and 24 h, and the expression levels of Beclin1 and the ratios of LC3-Ⅱ/LC3-Ⅰ both at 6 and 12 h (P<0.01, P<0.05), and an evident increase in the expression levels of p62 at 6, 12 and 24 h after CI (P<0.05, P<0.01).
Conclusion: Acupuncture stimulation of GV26 and PC6 can reduce the CI volume and improve neurological function in CI rats， which may be related to its efficacy in down-regulating the expression of Beclin1 and the ratio of LC3-Ⅱ/LC3-Ⅰ, and up-regulating the expression of p62 in the ischemic brain tissue， thereby improving autophagy flux.
目的：观察针刺对脑缺血损伤大鼠脑梗死体积及自噬相关蛋白表达的影响，探讨针刺拮抗大鼠脑缺血损伤的效应及其可能的机制。方法：SD大鼠随机分为假手术组、模型组、针刺组，每组根据缺血时间不同分为3、6、12和24 h亚组，每个亚组7只。采用线栓法制备大脑中动脉栓塞模型。造模成功后，各针刺组于“水沟”“内关”进行针刺，留针30 min。观察干预后不同时点各组大鼠神经功能缺损评分变化；用2，3，5-三苯基氯化四氮唑染色法观察各组大鼠脑梗死体积百分比；Western blot法检测各组大鼠大脑皮层缺血区域自噬相关基因Beclin1、微管相关蛋白1轻链3(LC3)、p62的表达。结果：与同时点假手术组比较，模型组大鼠神经功能缺损评分、脑梗死体积百分比、大脑皮层Beclin1蛋白表达水平及LC3-Ⅱ/LC3-Ⅰ比值均明显升高(P<0.01，P<0.05)，p62蛋白表达水平降低(P<0.01)。与同时点模型组比较，针刺组大鼠6、12、24 h神经功能缺损评分及各时点脑梗死体积百分比、3 h的p62表达水平降低(P<0.01，P<0.05)，6、12 h的Beclin1表达水平及LC3-Ⅱ/LC3-Ⅰ比值降低（P<0.01，P<0.05），6、12、24 h的p62表达水平升高(P<0.05，P<0.01)。结论：针刺治疗可使大鼠脑缺血后脑梗死体积缩小，改善其神经功能损伤，该效应可能与其调控大鼠缺血脑组织中Beclin1、p62表达和LC3-Ⅱ/LC3-Ⅰ，从而改善自噬流有关。.
Keywords: Acupuncture; Autophagy flux; Beclin1; Cerebral ischemia; Microtubule-associated protein 1 light chain 3; p62.