[Effect of moxibustion with deqi on Aβ-receptor mediated transport and enzymatic degradation in hippocampus in rats with Alzheimer's disease].

To observe the clinical effect of moxibustion with deqi on Alzheimer's disease (AD) rats, and evaluate its effect on β-amyloid (Aβ) transport and enzymatic degradation proteins, to explore its molecular mechanism for improving cognitive function.Sixty SPF-grade male SD rats were randomly divided into a blank group (8 rats), a sham-operation group (8 rats) and a model establishment group (44 rats). The rats in the model establishment group were injected with Aβ1-42 at bilateral ventricles to establish AD model. Among the 38 rats with successful model establishment, 8 rats were randomly selected as the model group, and the remaining rats were treated with mild moxibustion at "Dazhui" (GV 14), once a day, 40 min each time, for 28 days. According to whether deqi appeared and the occurrence time of deqi, the rats were divided into a deqi group (12 rats), a delayed deqi group (10 rats) and a non-deqi group (8 rats). After the intervention, the Morris water maze test was applied to evaluate the cognitive function; the HE staining was applied to observe the brain morphology; the Western blot method was applied to measure the protein expression of Aβ and its receptor mediated transport [low-density lipoprotein receptor-related protein (LRP) 1, receptor for advanced glycation end products (RAGE), apolipoprotein E (ApoE)] and enzymatic degradation [neprilysin (NEP), insulin degrading enzyme (IDE), endothelin converting enzyme (ECE)-1 and angiotensin converting enzyme (ACE) 2].Compared with the sham-operation group, in the model group, the escape latency was prolonged (P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were reduced (P<0.01); the brain tissue was seriously damaged; the expression of hippocampal Aβ and RAGE was increased (P<0.01), and the expression of hippocampal LRP1, ApoE, NEP, IDE, ECE-1 and ACE2 was decreased (P<0.01). Compared with the model group, the escape latency was shortened in the deqi group (P<0.05, P<0.01), and the escape latency in the delayed deqi group and the non-deqi group was shortened from Day 2 to Day 5 (P<0.05, P<0.01), and the times of platform crossing and the ratio of platform quadrant to total time were increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the brain damage in each moxibustion group was reduced, which was smallest in the deqi group, followed by the delayed deqi group and the non-deqi group; the expression of Aβ and RAGE was decreased (P<0.01, P<0.05) and the expression of LRP1 and IDE was increased in each moxibustion group (P<0.01, P<0.05); the expression of ApoE was increased in the deqi group and the delayed deqi group (P<0.01, P<0.05); the expression of NEP was increased in deqi group (P<0.05), and the expression of ECE-1 and ACE2 was increased in the deqi group and the delayed deqi group (P<0.05). Compared with the delayed deqi group and the non-deqi group, the escape latency in the deqi group was shortened from Day 3 to Day 5 (P<0.05), and the times of platform crossing and the ratio of platform quadrant to total time were increased (P<0.05, P<0.01). Compared with the non-deqi group, the expression of Aβ was reduced (P<0.05), the expression of LRP1 and ApoE was increased in the deqi group (P<0.05). The expression of NEP in the deqi group was higher than that in the delayed deqi group and the non-deqi group (P<0.05).Compared with non-deqi, moxibustion with deqi could promote Aβ transport and degradation, thereby reducing Aβ level in the brain and improving cognitive function for AD rats.目的：观察艾灸“得气”对阿尔茨海默病（Alzhemier's disease, AD）模型大鼠的疗效及脑内β淀粉样蛋白（Aβ）转运和降解相关酶蛋白表达的影响，探讨其改善认知功能的分子机制。方法：将60只SPF级SD雄性大鼠随机分为空白组（8只）、假手术组（8只）和造模组（44只），造模组采用双侧脑室注射Aβ1-42建立AD模型。38只造模成功的大鼠随机取8只作为模型组，剩余大鼠于“大椎”穴行温和灸，每天1次，每次40 min，共28 d。根据“得气”出现与否及出现早晚分为艾灸得气组（12只）、艾灸迟发得气组（10只）和艾灸非得气组（8只）。干预后各组大鼠行Morris水迷宫试验检测认知功能；HE染色观察大鼠脑组织形态；Western blot法检测大鼠海马Aβ及其受体介导转运相关蛋白[低密度脂蛋白受体相关蛋白（LRP）1、高级糖化终产物受体（RAGE）、载脂蛋白E（ApoE）]和降解相关酶[中性内肽酶（NEP）、胰岛素降解酶（IDE）、内皮素转换酶（ECE）-1和血管紧张素转换酶（ACE）2]的蛋白表达。结果：与假手术组比较，模型组逃避潜伏期延长（P<0.01），平台穿越次数、平台象限与总时间之比减少（P<0.01）；脑组织损伤较重；海马Aβ、RAGE蛋白表达升高（P<0.01），海马LRP1、ApoE、NEP、IDE、ECE-1、ACE2蛋白表达降低（P<0.01）。与模型组比较，艾灸得气组逃避潜伏期缩短（P<0.05，P<0.01），艾灸迟发得气组和艾灸非得气组第2~5天逃避潜伏期缩短（P<0.05，P<0.01），艾灸得气组和艾灸迟发得气组平台穿越次数、平台象限与总时间之比增加（P<0.01，P<0.05）；各艾灸组脑损伤均减轻，其中艾灸得气组损伤程度最轻，艾灸迟发得气组次之，艾灸非得气组稍有改善；各艾灸组Aβ、RAGE蛋白表达均降低（P<0.01，P<0.05），LRP1、IDE蛋白表达升高（P<0.01，P<0.05），艾灸得气组和艾灸迟发得气组ApoE蛋白表达升高（P<0.01，P<0.05），艾灸得气组NEP表达增加（P<0.05），艾灸得气组、艾灸迟发得气组ECE-1和ACE2蛋白表达增加（P<0.05）。与艾灸迟发得气组、艾灸非得气组比较，艾灸得气组第3~5天逃避潜伏期缩短（P<0.05），平台穿越次数、平台象限与总时间之比增加（P<0.05，P<0.01）；与艾灸非得气组比较，艾灸得气组Aβ降低（P<0.05），LRP1和ApoE蛋白表达升高（P<0.05）；艾灸得气组NEP表达高于艾灸迟发得气组、艾灸非得气组（P<0.05）。结论：艾灸“得气”较非“得气”能更好地促进Aβ转运和降解，从而降低脑内Aβ水平，改善AD模型大鼠认知功能。.