针加灸对阿尔茨海默病大鼠海马区蛋白酪氨酸激酶-2/信号转导和转录激活因子-3信号通路的影响

Acupuncture plus moxibustion intervention improves learning-memory ability by suppressing hippocampal JAK2/STAT3 signaling in Alzheimer's rats

目的:通过观察针加灸对阿尔茨海默病(AD)大鼠海马区蛋白酪氨酸激酶-2(JAK2)、信号转导和转录激活因子-3(STAT3)、细胞因子信号转导抑制因子-3(SOCS3)的影响,探讨针加灸治疗AD的作用机制。方法:SD大鼠随机分为对照组、假手术组、模型组、治疗组,每组15只。采用双侧海马注射5!L Aβ1-42法(1!L/min)制备AD大鼠模型。治疗组予针刺加艾灸"百会"、双侧"肾俞"穴进行治疗,15min/次,每日1次,5次为1个疗程,共治疗4个疗程,每个疗程期间休息2d。治疗结束后Morris水迷宫实验检测各组大鼠记忆和空间探索能力,免疫组化法和Western blot法分别测定各组大鼠海马区JAK2、STAT3、SOCS3的阳性细胞数及蛋白表达水平。结果:与对照组和假手术组比较,模型组大鼠平均逃避潜伏期明显延长(P<0.01),跨越原平台次数和在安全象限平台停留时间明显缩短(P<0.01);与模型组比较,治疗组大鼠平均逃避潜伏期明显缩短(P<0.01),跨越原平台次数和安全象限平台停留时间明显延长(P<0.01)。与对照组和假手术组比较,模型组大鼠海马区JAK2、STAT3阳性细胞数及蛋白表达明显增多(P<0.01),SOCS3阳性细胞数及蛋白表达明显减少(P<0.01);与模型组比较,治疗组大鼠海马区JAK2、STAT3阳性细胞数及蛋白明显减少(P<0.01),SOCS3阳性细胞数及蛋白表达明显增多(P<0.01)。结论:JAK2/STAT3信号通路和负反馈因子SOCS3均参与了AD发病的病理过程,针灸可能通过上调SOCS3来抑制JAK2/STAT3信号通路,降低其活化,减少慢性炎性反应发生发展,从而提高AD大鼠学习记忆能力,达到治疗AD的作用。

Objective To investigate the effect of acupuncture plus moxibustion on learning-memory ability and expression of hippocampal Janus kinase-2(JAK2)/signal transducer and activator of transcription-3(STAT3)/suppressors of cytokine signaling-3(SOCS3)signaling in Alzheimer’s Disease(AD)rats,so as to reveal their mechanisms underlying improvement of AD.Methods A total of 60 SD rats were randomly divided into four groups:normal control,sham-operation,model and acupuncture-moxibustion(Acu-moxi,n=15 in each group)groups.The AD model was established by microinjection ofβ-amyloid 1-42(Aβ1-42,5μL)into the bilateral hippocampus.Seven days after modeling,Acu-moxi intervention was given.After insertion of acupuncture needles into"Baihui"(GV20)and bilateral"Shenshu"(BL23)and manipulating them for a while,the needles were then retained for 15 min,when,the mild moxibustion was performed at the same time.The treatment was conducted once daily,5 times a week for consecutive 4 weeks.After the treatment,Morris water maze test was used to detect the animals’learning-memory ability.Immunohistochemistry and Western blot were respectively used to detect the number of positive cells and protein expression levels of JAK2,STAT3 and SOCS3 in the hippocampus tissue.Results Following modeling and compared with the normal control and sham-operation groups,the average escape latency was significantly prolonged(P<0.01),and the number of the original platform crossing and the residence time in the platform quadrant were significantly shortened in the model group(P<0.01).The numbers of hippocampal JAK2-and STAT3-positive cells and expression levels of hippocampal JAK2 and STAT3 proteins were significantly increased(P<0.01),and the number of hippocampal SOCS3-positive cells as well as the expression of SOCS3 protein significantly decreased in the model group relevant to the normal control and sham-operation groups(P<0.01).After the intervention,the average escape latency was significantly shortened(P<0.01),and the number of the original platform crossing and the residence time in the platform quadrant were significantly increased in the Acu-moxi group(P<0.01),and the expression levels of JAK2 and STAT3 were significantly down-regulated and that of SOCS3 was considerably up-regulated in the Acu-moxi group relevant to the model group(P<0.01).Conclusion Acu-moxi intervention can improve the learning-memory ability in AD rats,which is associated with its functions in inhibiting hippocampal JAK2/STAT3 signaling and up-regulating SOCS3(a negative feedback factor)protein level.