基于 PI3K／A kt信号转导通路探讨电针足三里、曲池对脑缺血再灌注大鼠神经细胞凋亡的影响

目的：观察电针干预对大鼠脑缺血再灌注损伤的神经保护作用，应用磷脂酰肌醇‐3激酶／丝氨酸‐苏氨酸蛋白激酶（PI3K／Akt）信号转导通路抑制剂LY294002，深入探讨电针的神经保护作用与 PI3K／Akt信号转导通路的关系。方法本研究采用Zealonga线栓法制备大鼠大脑中动脉闭塞（MCAO）缺血再灌注模型。将60只SD大鼠随机分为5组：假手术（SC）组、模型（IC）组、电针（EA）组、电针＋溶剂（DMSO）组，电针＋抑制剂（LY294002）组，每组各12只。术后24 h开始电针治疗30 min ，1次／天，治疗3 d。采用Zealonga 5分评价方法观察神经功能缺损恢复程度；氯化三苯四唑（TTC）法脑组织染色计算脑梗死体积；TUNEL法观察皮质区缺血周围神经细胞凋亡的情况；应用Western blot检测脑组织中PI3K、Akt、p‐Akt、bad、p‐bad蛋白表达水平。结果神经功能评分、TTC染色显示EA组与DMSO组的神经功能恢复及脑缺血改善明显优于IC组和LY294002组（P＜0．05）；EA组与DMSO组凋亡阳性细胞数少于IC组和LY294002组，差异有统计学意义（P＜0．01）；与 IC组及 LY294002组比较，EA组与DMSO组提高了PI3K、p‐Akt及p‐bad的蛋白表达（P＜0．05）。结论 PI3K／Akt信号转导通路参与了电针足三里穴、曲池穴对脑缺血再灌注损伤的神经保护作用。

Electro-acupuncture at points of Zusanli and Quchi exerts anti-apoptotic effect through the modulation of PI3K/Akt signalling pathway

Objective To evaluate the neuroprotective effect of electro‐acupuncture(EA) on cerebral ischemia‐reperfusion (IR) injury and deeply investigate the relationship between this neuroprotective effect and PI3K/Akt pathway .Methods A total of 60 Male adult SD rats were randomly divided into five groups:sham control group(SC ,n=12) ,ischemia control group ,(IC group , n=12) electro‐acupuncture group(EA group ,n= 12) ,EA + DMSO group(DMSO group ,n= 12) and EA + LY294002 group (LY2940002 group ,n=12) .Rats in the IC group、EA group、DMSO group and LY2940002 group underwent 2 h of middle cerebral artery occlusion(MCAO) ,followed by 72 h of reperfusion .DMSO or LY294002 was injected into the lateral ventricle at 30 min be‐fore the ischemia .Rats of the IC group ,EA group ,DMSO group and LY2940002 group received electro‐acupuncture at 24 h after the operation and continued until animals were sacrificed at 72 h after the operation ,and the stimulation parameters were set as fol‐lows :disperse wave ,30 min of each time ,once a day .Neurological deficit scores were assessed at 24 h ,48 h and 72 h after the IR in‐jury .The infarct volume was determined at 72 h after the IR injury using TTC staining .Apoptotic cells in the cerebral cortex were quantified under confocal fluorescence microscope using TUNEL staining .The expression of PI3K ,Akt ,p‐Akt ,Bad and p‐Bad at the protein level was assessed by Western blotting .Results Significant differences were observed in terms of neurological deficit scores between and among the EA group ,DMSO group and other groups at 48 h and 72 h after the cerebral IR injury(P<0 .05) .At 72 h after the cerebral IR injury ,the infarct volume of the IC group and LY294002 group was significantly larger than those of the EA group and DMSO group(P<0 .05) .Compared with the IC group and LY294002 group ,EA treatment greatly reduced the number of apoptotic nerve cells(P<0 .01) .The expression of PI3K ,p‐Akt and p‐Bad at the protein level in the EA group and DMSO group were higher than those of the IC group and LY294002 group(P<0 .05) .Conclusion EA treatment at points of Zusanli(ST36) and Quchi(LI11) exerted the neuroprotective effect on the cerebral IR injury through the modulation of PI3K/Akt pathway .