电针刺激对APP/PS1双转基因阿尔兹海默病模型小鼠皮质老年斑形成的影响及机制研究

关键词：电针  阿尔兹海默病  老年斑  皮质

Keywords:electro-acupuncture  Alzheimer's disease  senile plaques  cortex

摘要：

      摘要 目的：研究电针刺激对APP/PS1双转基因阿尔兹海默病（AD）模型小鼠学习记忆和空间探索能力、皮质内老年斑（SP）的变化及形成机制的影响。 方法：将3月龄雄性小鼠随机分为4组：对照组、模型组、电针两疗程组和三疗程组，每组6只；对照组为野生型小鼠，其余三组为APP/PS1双转基因小鼠。通过电针刺激小鼠百会穴和肾俞穴，频率为2Hz，电流2mA，持续15min，每天1次，7天1疗程。应用水迷宫实验观察学习记忆和空间探索能力,Western Blot分析各组皮质区的顶叶和颞叶APP、IDE和BACE1蛋白的表达水平，免疫组化检测皮质区SP的表达。 结果：行为学实验结果发现，与对照组相比，模型组小鼠的逃避潜伏期和搜索路径均明显增加（P<0.05），穿越平台的次数明显减少（P<0.0001）；而与模型组相比，治疗组小鼠的逃避潜伏期和搜索路径均明显缩短（P<0.05），穿越平台的次数明显增加（P<0.01）；与电针两疗程组相比，电针三疗程组的逃避潜伏期和搜索路径也明显缩短（P<0.05），穿越平台的次数明显增加（P<0.05）。免疫组化结果显示：对照组小鼠皮质区的顶叶和颞叶没有SP；与模型组相比，电针三疗程组的SP数目明显降低（P<0.01）。Western Blot检测结果显示,模型组小鼠皮质区的顶叶和颞叶APP、BACE1的水平明显高于对照组（P<0.0001），IDE的水平明显低于对照组（P<0.0001）；而与模型组相比，两个治疗组APP、BACE1的表达明显下调（P<0.05；P<0.001），IDE的表达明显上调（P<0.05；P<0.01）；电针三疗程组APP、BACE1的水平明显低于电针两疗程组（P<0.01）。 结论：电针刺激能够改善APP/PS1双转基因AD模型小鼠的学习记忆和空间探索能力；另外，电针刺激可能通过影响皮质区APP、BACE1以及IDE等蛋白表达来调节Aβ的浓度，从而减少SP的形成和沉积。

Abstract:

      Abstract Objective: To study effects of electro-acupuncture on the learning, memory and spatial abilities of the APP /PS1 double transgenic Alzheimer's disease (AD) model mice, the change of senile plaque (SP) in cortex and its formation mechanism. Method: The male mice(3-month-old) were divided into four groups，the control group, the model group, the 2 periods of EA treatment group and the 3 periods of EA treatment group, six mice in each group， the control group consisted of the wild type mice, the other three groups consisted of APP / PS1 double transgenic mice. Acupuncture at “Baihui” and “Shenshu” acupoints of the treatment groups, then apply 2Hz, 2mA for 15 minutes, once a day, 7 days a period, a day break between two periods. Morris water maze test was conducted to observe the learning, memory and spatial exploration ability. The expressions of APP, IDE and BACE1 in Parietal lobe and temporal lobe of cortex were analyzed by Western Blot, and the expression of SP in cortex was detected by immunohistochemistry. Result: Behavioral test showed that, the escape latency and the search path of the model group were significantly longer than that of the control group (P<0.05). the number of crossing platforms was significantly lower(P<0.0001). However, compared with model group, the escape latency and the search path of the treatment group were significantly shortened (P<0.05), the number of crossing platforms were significantly increased (P<0.01). Compared with the 2 periods of electro-acupuncture treatment group, the escape latency and the search path of the 3 periods of electro-acupuncture treatment group were also significantly shortened (P<0.05), the number of crossing platforms was also significantly increased (P<0.05). Immunohistochemical results showed that there was no SP in the Parietal lobe and temporal lobe of cortex of the control group， the number of SP in the 3 periods of electro-acupuncture treatment group was significantly decreased (P<0.01) comparing with the model group. The results of Western and Blot showed that, comparing to the control group, the model group had more contents with APP，BACE1 in the Parietal lobe and temporal lobe of cortex（P<0.0001）, and less IDE（P<0.0001）. However, comparing to the model group, the two treatment groups had less contents with APP, BACE1（P<0.05, P<0.001）, and more contents with IDE（P<0.05, PP<0.01），the 3 periods of electro-acupuncture treatment group had less contents with APP and BACE1（P<0.01）than the 2 periods of electro-acupuncture treatment group. Conclusion: Electro-acupuncture can improve the learning, memory and spatial exploration abilities of APP / PS1 double transgenic AD model mice. In addition, electro-acupuncture may regulate the content of Aβ by affecting the expression of APP, BACE1 and IDE in cortex, thereby reducing the formation and deposition of SP.