[Effect of electroacupuncture on complement C1q and microglia phagocytosis in hippocampus of SAMP8 mice].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of Iba-1, complement C1q and CD68 in hippocampus of SAMP8 mice, so as to explore its mechanisms underlying improvement of Alzheimer's disease (AD). METHODS: Twenty-four male SAMP8 mice were randomly and equally divided into model and EA groups, and 12 SAMR1 mice were used as the control group. EA (2 Hz, 1.5-2.0 mA) was applied to "Baihui" (GV20), "Dazhui"(GV14) and "Shen-shu"(BL23) for 20 min once daily in the EA group, each course of treatment was 8 days, with an interval of 2 days between two courses, and the mice were treated for 3 courses. Morris water maze test was performed to assess the learning-memory ability of mice. The positive expression levels of Iba-1 and CD68 proteins in the hippocampus CA1 region were detected by immunohistochemistry. The mRNA and protein expression levels of Iba-1,C1q and CD68 in the hippocampus were detected by real-time PCR and Western blot, separately. RESULTS: Compared with the control group, the average escape latency of Morris water maze test was prolonged in the model group (P<0.01), duration of swimming in the original platform quadrant and the number of original platform crossing were significantly shorter and decreased respectively (P<0.01). Compared with the model group, the average escape latency in the EA group was shortened (P<0.05, P<0.01), the duration of swimming in the original platform quadrant and the number of original platform crossing were significantly prolonged and increased (P<0.01). The immunoactivity of Iba-1 and CD68 in hippocampal CA1 region, and mRNA and protein expression levels of hippocampal Iba-1,C1q and CD68 were significantly up-regulated in the model group in contrast to the control group (P<0.01, P<0.05), and obviously down-regulated except the mRNA expression level of hippocampal Iba-1 in the EA group relevant to the model group (P<0.01, P<0.05). CONCLUSION: EA can improve the learning and memory ability of SAMP8 mice, which may be associated with its effect in inhibiting of complement C1q-dependent microglial phagocytosis in the hippocampus.

[Effect of early intervention of electroacupuncture on learning-memory ability and level of hippocampal phosphorylated Tau protein in SAMP8 mice].

OBJECTIVE: To explore the effect of early intervention electroacupuncture (EA) at "Baihui" (GV 20), "Dazhui" (GV 14) and "Shenshu" (BL 23) on the learning-memory ability and the expression of phosphorylated Tau protein in the hippocampus of SAMP8 mice, so as to provide reference for the intervening period of EA for Alzheimer's disease (AD). METHODS: A total of 36 3-month old SAMP8 mice were randomly divided into a model group, a 3-month-old EA group and a 9-month-old EA group, 12 mice in each group. Twelve normal SAMR1 mice with the same age were taken as the control group. The mice in the 3-month-old EA group and 9-month-old EA group were treated with EA at "Baihui" (GV 20), "Dazhui" (GV 14) and "Shenshu" (BL 23) separately 3 months old and 9 months old (continuous wave, 2 Hz, 1.5-2 mA), 20 min each time, once a day, 8 days as a course of treatment, with an interval of 2 days between courses, totally 3 courses of treatment were given. The mice sample in each group was collected at the age of 10 months after the learning-memory ability tested by Morris water maze. The expression of phosphorylated Tau protein in the hippocampus was detected by immunohistochemistry and Western blot, and the expression of Tau mRNA was detected by real-time PCR. RESULTS: Compared with the control group, in the model group, the escape latency was significantly increased (P<0.01), the time of stay in the original platform quadrant and the number of crossing the platform quadrant were reduced (P<0.01), and the expressions of phosphorylated Tau protein and Tau mRNA in hippocampus were increased (P<0.01). Compared with the model group, in the 3-month-old EA group and 9-month-old EA group, the escape latency was significantly reduced (P<0.05), the time of stay in the original platform quadrant and the number of crossing the platform quadrant were increased (P<0.05), and the expressions of phosphorylated Tau protein and Tau mRNA in hippocampus were reduced (P<0.05). Compared with the 9-month-old EA group, in the 3-month-old EA group, the escape latency was significantly reduced (P<0.05), the time of stay in the original platform quadrant and the number of crossing the platform quadrant were increased (P<0.05), and the expressions of phosphorylated Tau protein and Tau mRNA were reduced (P<0.01). CONCLUSION: The early EA intervention could more effectively improve the learning-memory ability and inhibit phosphorylation of Tau protein in the hippocampus of SAMP8 mice.

Electroacupuncture Reduces Aß Production and BACE1 Expression in SAMP8 Mice.

Electroacupuncture (EA) has been reported to have beneficial effects on Alzheimer's disease (AD). BACE1 (ß-site amyloid precursor protein-cleaving enzyme 1) is involved in the abnormal production of amyloid-ß plaque (Aß), a hallmark of AD pathophysiology. Thus, the present study investigated the effects of EA on memory impairment, Aß production, and BACE1 expression in senescence-accelerated mouse prone 8 (SAMP8) mice. We found that EA improved spatial learning and memory impairment of SAMP8 mice. Furthermore, EA attenuated Aß production and repressed the expression of BACE1 in the hippocampus of SAMP8 mice. Taken together, our results suggest that EA could have a potential therapeutic application in AD and that BACE1 may be an important target of EA in the treatment of AD.