“通督启神”电针对SAMP8小鼠认知记忆功能及额叶区炎症因子表达的影响

Effect of‘Tongdu Qishen’Electro-Acupuncture on Cognitive and Memory Function and Expressions of Inflammatory Factors in Frontal Lobe of SAMP8 Mice

目的:探讨“通督启神”电针法对SAMP8小鼠行为学及额叶区炎症因子表达的影响,分析电针对SAMP8小鼠的作用机制。方法:SAMP8小鼠随机分为模型组、电针组和药物组,以同源SAMR1小鼠作为正常对照组,每组各8只。电针组予点刺人中穴、平刺百会和印堂穴,针柄连接电针仪,15 min/次;药物组予以多奈哌齐灌胃给药;4组均给予相同的固定、抓取操作。采用Morris水迷宫观察各组小鼠行为学指标,评价其认知、记忆功能;采用苏木精-伊红(HE)染色观察小鼠额叶区神经细胞的形态学改变;免疫组织化学法观察小鼠额叶区基质金属蛋白酶9(MMP-9)、细胞间黏附分子(ICAM-1)的阳性表达;ELISA法检测小鼠额叶IL-1β、IL-10和Il-6的表达。结果:行为学显示,相比正常对照组,模型组逃避潜伏期显著延长(P<0.01);与模型组相比,药物组与电针组逃避潜伏期显著缩短(P<0.05或P<0.01),药物组与电针组之间差异无统计学意义(P>0.05)。SAMP8小鼠较正常对照组SAMR1小鼠游泳速度偏慢(P<0.05),但各组SAMP8小鼠之间速度差异无统计学意义(P>0.05)。形态学显示:相比正常对照组,模型组额叶区细胞数目减少、边界不清,细胞间结构松散排列紊乱、核固缩深染色明显,且存在炎症细胞增生、聚集的现象,在微血管周围形成血管套,而药物组、电针组可改善上述病理特征。与正常组相比,模型组额叶区MMP-9、ICAM-1表达增加(P<0.01);与模型组相比,药物组、电针组可一定程度抑制MMP-9、ICAM-1表达(P<0.05或P<0.01),药物组与电针组间差异无统计学意义(P>0.05)。分子生物学:与正常对照组对比,模型组IL-1β、IL-6显著升高,IL-10显著减少(P<0.01);而药物组、电针组可改善上述情况,促进IL-10表达,抑制IL-1β、IL-6的表达(P<0.05或P<0.01)。且药物组与电针组间仅在IL-10调控水平上差异有统计学意义(P<0.01)。结论:“通督启神”电针法可有效提高SAMP8小鼠的学习记忆功能,其作用机制可能是通过抑制额叶区ICAM-1、MMP-9的表达,减缓中枢免疫细胞的增生、聚集,抑制过度炎症反应对神经细胞的损伤,提高小鼠认知能力。

Objective:To explore the effect of‘Tongdu Qishen’electro-acupuncture on the behavior and expressions of inflammatory factors in frontal lobe of SAMP8 mice,and to analyze the mechanism of electro-acupuncture(EA)in SAMP8 mice.Methods:SAMP8 mice were randomly divided into the model group,the EA group and the medication group,with 8 mice in each group.Another 8 SAMR1 mice were taken as the normal control.The EA group was treated with electro-needling Renzhong(DU26),Baihui(DU20)and Yintang(EX-HN3),15 minutes per time;the medication group was given Donepezil by gavage.Morris water maze was used to observe the behavioral indexes of mice in each group to evaluate their cognitive and memory functions.HE staining was used to observe the morphological changes of nerve cells in frontal lobe of mice.The expressions of matrix metalloproteinase-9(MMP-9)and intercellular adhesion molecule-1(ICAM-1)in frontal lobe of mice were observed by immunohistochemical method,and the expressions of IL-1β,IL-10 and IL-6 in frontal lobe of mice were detected by ELISA method.Results:In terms of the escape latency,it was significantly prolonged in the model group compared to that in the normal control group(P<0.01);it was significantly shortened in the medication group and in the EA group compared to that in the model group(P<0.05,P<0.01);there was no statistical difference between the medication group and the EA group(P>0.05).The swimming speed of SAMP8 mice was slower than that of SAMR1 mice in the normal control group(P<0.05),but there was no significant difference in swimming speed among SAMP8 mice in each group(P>0.05).Morphology showed that compared to those in the normal control group,the number of cells in the frontal lobe was reduced,the boundary was not clear,the structure between cells was loose and disordered,nuclear pyknosis and deep staining were obvious,and inflammatory cells proliferated and aggregated,forming a vascular sheath around the micro-vessels in the model group;which were improved after the intervention of medication and EA.The expressions of MMP-9 and ICAM-1 in the frontal lobe were significantly increased in the model group compared to those in the normal control group(P<0.01);which were could be inhibited after the interventions of medication and EA(P<0.05,P<0.01);there were no statistical differences between the medication group and the EA group(P>0.05).Molecular biology showed that the expressions of IL-1βand IL-6 were significantly increased,and the expression of IL-10 was significantly decreased in the model group compared to those in the normal control group(P<0.01);the expression of IL-10 was promoted and the expressions of IL-1βand IL-6 were inhibited after the interventions of medication and EA(P<0.05,P<0.01);there were statistical difference in the expression of IL-10 between the medication group and the EA group(P<0.01).Conclusion:‘Tongdu Qishen’electro-acupuncture can effectively improve the learning and memory function of SAMP8 mice,and its mechanism may be through inhibiting the expressions of ICAM-1 and MMP-9 in frontal lobe,slowing down the proliferation and aggregation of central immune cells,inhibiting the injury of nerve cells caused by excessive inflammatory reaction,and improving the cognitive ability of mice.