摘要
Objective:To observe the effects of electroacupuncture(EA)with three frequencies(100 Hz,2 Hz,and 2 Hz/100 Hz)on the apoptosis of neurons and c-Jun N-terminal kinase(JNK)signaling pathway in the hippocampus of rats with vascular dementia(VD),and explore the mechanism of EA intervention for VD.Methods:Fifty male Sprague-Dawley rats were randomly divided into a model group,a sham operation group,a 100 Hz EA group,a 2 Hz EA group,and a 2 Hz/100 Hz EA group,with ten rats in each group.The VD model rats were established by repeated ischemia-reperfusion of bilateral common carotid arteries.The rats in the EA groups received EA intervention at Baihui(GV20),Dazhui(GV14),Geshu(BL17)and Zusanli(ST36),once a day for 14 d.Afterward,Morris water maze was used to examine the learning and memory performances of the rats in each group,hematoxylin-eosin staining to observe the histomorphological changes in the hippocampal CA1 region,terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling to test the apoptosis of neurons in the hippocampal CA1 region,and Western blot to detect the protein expression levels of JNK,phosphorylated JNK(p-JNK),Caspase-8,and Caspase-3 in the hippocampus tissue.Results:Compared with the sham operation group,the escape latency of the model group in water maze test was prolonged;the number of crossing the original platform was decreased(P<0.01);the hippocampal neurons were severely damaged and the number of surviving neurons was decreased(P<0.01),whereas the number of apoptotic neurons was increased(P<0.01);the protein expression levels of JNK,p-JNK,Caspase-8,and Caspase-3 in the hippocampus were significantly increased(P<0.01).Compared with the model group,the escape latency of each EA group was significantly shortened;the number of crossing the original platform was significantly increased(P<0.01);the damage of hippocampal neurons was alleviated,the number of surviving neurons was increased(P<0.01),and the number of apoptotic neurons was decreased(P<0.01);the protein expression levels of JNK,p-JNK,Caspase-8,and Caspase-3 in the hippocampus were decreased(P<0.01).The results in the 2 Hz EA group and the 2 Hz/100 Hz EA group were superior to those in the 100 Hz EA group.Conclusion:EA with the three frequencies(100 Hz,2 Hz,and 2 Hz/100 Hz)can improve the learning and memory performances in VD rats subjected to ischemia-reperfusion,its mechanism may be related to the inhibition of neuronal apoptosis and the regulation of the related protein expression of JNK signaling pathway,and the intervention effects of EA with 2 Hz and 2 Hz/100 Hz are more significant.
目的:观察100 Hz、2 Hz、2 Hz/100 Hz三种频率电针(EA)对血管性痴呆(VD)大鼠海马神经元凋亡和c-jun氨基末端激酶(JNK)信号通路的影响,探讨电针干预VD的效应机制.方法:将50只雄性Sprague-Dawley大鼠随机分为假手术组、模型组、100 Hz电针组、2 Hz电针组和2 Hz/100 Hz电针组,每组10只.采用双侧颈总动脉反复缺血再灌注制备VD模型,造模后各电针组取百会、大椎、膈俞和足三里进行相应频率的电针干预,每天1次,连续14 d.干预结束后,使用Morris水迷宫检测各组大鼠学习记忆成绩;苏木素-伊红染色法观察海马CA1区组织形态学变化;原位末端转移酶标记法(TUNEL)检测海马CA1区神经元凋亡;免疫印迹法检测海马组织JNK、磷酸化JNK(p-JNK)、半胱氨酸蛋白酶-8(Caspase-8)和半胱氨酸蛋白酶-3(Caspase-3)蛋白表达.结果:与假手术组相比,模型组大鼠水迷宫测试逃避潜伏期延长,穿越原平台次数减少(P<0.01);海马区神经元损伤严重,神经元存活数量减少(P<0.01),凋亡神经元增多(P<0.01);海马JNK、p-JNK、Caspase-8和Caspase-3蛋白表达显著升高(P<0.01).与模型组相比,各电针组大鼠逃避潜伏期显著缩短,穿越原平台次数显著增多(P<0.01);海马神经元损伤减轻,神经元存活数量增多(P<0.01),凋亡神经元减少(P<0.01);海马JNK、p-JNK、Caspase-8和Caspase-3蛋白表达降低(P<0.01).2 Hz电针组和2 Hz/100 Hz电针组优于100 Hz电针组(P<0.01).结论:100 Hz、2 Hz和2 Hz/100 Hz三种频率电针均能改善缺血再灌注VD大鼠的学习记忆能力;其机制可能与电针抑制神经元细胞凋亡及调控JNK信号通路相关蛋白表达相关,且2 Hz与2 Hz/100 Hz电针干预效果更显著.
基金
河北省高等学校科学技术研究重点项目,No.ZD2018017
河北省自然科学基金面上项目,No.H2013206245
河北省中医药管理局科技支撑项目,No.2013002
河北中医学院省属高校基本科研业务费专项项目,No.YXZ2019005
