Effect Of Acupuncture Given At “si-guan Points”(Taichong LR-3 Combine With Hegu LI-4) On Hippocampal Autophagy Of Alzheimer’s Disease Model Rats

Objective To discuss the possible mechanism of the acupuncture treatment on model rats with Alzheimer’s Disease learning and memory ability, the expression of A-beta42, phosphorylated tau protein(p S396, p T231), and the influence of the hippocampus neuron, by given acupuncture at “Si-Guan points”(Taichong LR-3 combine with Hegu LI-4).Methods A total of 60, 2 months healthy male SD rats were divided randomly into normal group(n=15), sham group(n=15), model group(n=15), acupuncture group(n=15). The rats of the normal group of conventional feed were without any treatment, the sham group were given citric acid/sodium citrate buffer by lateral ventricle injection,and the rats of the orther groups were injected with the same vilume of STZ into the lateral ventricle, to construct AD model.The rats of the acupuncture group, were acupunctured LR-3 and LI-4 on both sides, stabbed 2-3 mm, each acupoint retained 15 min. Acupuncture treatment frequency was once a day, takes six days then has a rest day as one course. Treatment lasted four weeks. The twisting was performed within the range of 90–180° at a rate of 120-150 times/min. Morris Water Maze was used to test the ability of learning and memory of rats. Hematoxylin-eosin staining was used to observe the morphology of neurons in the hippocampus. Immunohistochemical was used to detect the expression of Phosphorylated tau protein and Aβ42 in hippocampus. Western Blot was used to detect the expressionof p62 and LC3-Ⅱ in hippocampus.Results 1.Morris water maze test results: The escape latency of rats of groups were shorter with the increase of training days in place navigation test. Compared with the sham groups, the escape latency of the model group were significantly prolonged(P<0.01); and more prolonged than the acupuncture group(P<0.01). According to the results of space exploration test, the number of model rats through the original machine area were less than the sham groups(P<0.01), and the acupuncture group were more than the model group(P<0.01). 2.HE dyeing observation:morphology and structure of neurons in hippocampus of rats in Normal group were as normal as Sham group. The loss of normal neurons were evident in model group, morphology and structure of neurons were also abnormal;The acupuncture group was better than the model group. 3.Immunohistochemical results: The expression of A-beta 42, p S396, p T231 in model group rats hippocampus increased significantly compared with the sham groups(P<0.05); There was no significant difference between Sham group and Normal group(P>0.05); The expression of the acupuncture group were less than the model group(P<0.05). 4.Western Blot test results: The expression of Autophagy related proteins, p62 and LC3-Ⅱ, there was no significant difference between Sham group and Normal group(P>0.05); The expression of LC3-Ⅱ in the model group were significantly decreased relative to the sham groups(P<0.05), and the p62 increased marked(P<0.05); The relative expression of p62 in Acupuncture group were less than the model group(P<0.05), and the LC3-Ⅱ increased(P<0.05).Conclusions AD model rats were established by lateral intracerebroventricular injection of STZ, the ability of learning and memory was impaired, and expression of A-beta 42 and phosphorylated tau protein(p S396, p T231) were increased, Autophagy dysfunction emerged. The treatment by given acupuncture at “Si-Guan points” could improve the learning and memory ability of AD model rats, reduced the abnormal expression of phosphorylated tau protein, regulated the hippocampus disorder of autophagy function, reduced the expression of A-beta 42,and thus protected hippocampus neurons.