运动训练上调小胶质细胞α/β-水解酶结构域12改善阿尔茨海默病小鼠认知功能的作用与机制研究

关键词：阿尔茨海默病  运动训练  认知功能  小胶质细胞  α/β-水解酶结构域12

Keywords:Alzheimer's disease  physical exercise  cognitive impairment  microglia  α/β-hydrolase domain-containing 12

摘要：

      摘要 目的：研究运动训练调控小胶质细胞功能转变并改善阿尔茨海默病（Alzheimer’s disease，AD）小鼠认知功能的作用及分子机制。 方法：动物水平：将5月龄雄性5xFAD小鼠随机分为运动训练组和对照组，将5月龄雄性C57BL/6J小鼠纳入野生型对照组。运动训练组进行3个月的自主跑轮运动。训练结束后，利用水迷宫实验和旷场实验评估小鼠的情绪和认知能力。Western Blot法检测α/β-水解酶结构域12（α/β-hydrolase domain-containing 12，ABHD12）蛋白水平，免疫荧光法检测ABHD12在神经细胞中的定位。细胞水平：BV-2细胞转染慢病毒过表达或敲减ABHD12，Aβ-42聚合物诱导构建AD细胞模型，探索ABHD12对AD小胶质细胞功能调控的影响。 结果：①运动训练改善5xFAD小鼠的认知功能和焦虑情绪；②运动训练减少Aβ沉积，维持突触可塑性；③运动训练上调ABHD12，ABHD12表达在小胶质细胞，不表达在星形胶质细胞和神经元；④运动训练增加M2型小胶质细胞，减少M1型小胶质细胞；⑤敲减ABHD12可加重BV-2细胞炎症反应。 结论：运动训练可通过上调ABHD12，促使小胶质细胞向抗炎的M2表型极化，减少大脑Aβ沉积，从而改善阿尔茨海默病小鼠认知功能。

Abstract:

      Abstract Objective： To investigate the protective mechanism of physical exercise in regulating the transition of microglial phenotype and cognitive impairment in Alzheimer's disease（AD）. Method： Male 5xFAD mice at the age of 5 months were randomly divided into physical exercise （PE） and control group， and 5-month-old male C57BL/6J mice were taken as wild type group. Three months of wheel-running exercise was conducted in PE group. After completion of exercise program， the anxiety-like behavior and cognitive impairment were assessed by Morris water maze test and open field test. The protein expression of α/β-hydrolase domain-containing 12（ABHD12） was detected by Western Blots. The cellular location of ABHD12 was detected by immunofluorescence staining. In vitro study， BV-2 cells were transfected with lentivirus overexpression or knockdown ABHD12. Aβ-42 oligomer was incubated to establish the AD model in vitro. RT-qPCR、western blots and immunofluorescence staining were performed to verify the up- and down- regulation of ABHD12， as well as to explore the effect of ABHD12 in the transition of microglial phenotype. Result： Physical exercise ameliorated the cognitive and emotional dysfunction in 5xFAD mice. Physical exercise also reduced Aβ deposition and maintained the synaptic plasticity. Mechanically， physical exercise up-regulated the expression of ABHD12， which is expressed in microglia， but not in astrocytes or neurons. Physical exercise also increased the number of M2 microglia and decreased the number of M1 microglia. The knockdown of ABHD12 exacerbates the inflammatory response of Aβ oligomer induced BV-2 cells. Conclusion： Physical exercise ameliorated cognitive dysfunction in Alzheimer's disease by up-regulating ABHD12， prompting the transition of microglial phenotype to inhibit the inflammation， and to reduce the Aβ deposition.