目的:探究N-乙酰基-5-羟色胺-甲基转移酶(ASMT)基因敲除和运动对小鼠抑郁行为及神经炎症和肠道菌群的影响。方法:将6-7周龄雌性野生型小鼠和ASMT基因敲除小鼠随机分为安静组和运动组。12周的有氧跑台训练结束后，所有小鼠进行行为学测试，训练期间收集小鼠粪便，然后将小鼠麻醉处死后取前额皮质和下丘脑。采用RT-PCR检测前额皮质促炎与抗炎因子和TLR4/NF-κB信号通路相关基因的表达水平;采用 Western blotting检测下丘脑TLR4、p-IKBα、p65、p-p65和IL-Iβ的蛋白水平;采用16SrRNA基因测序检测小鼠运动干预第四周及第八周的粪便样本中菌群组成和丰度。结果:ASMT基因敲除会诱发小鼠的抑郁行为，运动可以有效缓解小鼠的抑郁行为。ASMT基因敲除后促炎因子水平和TLR4/NF-KB信号通路表达水平增加。肠道菌群16SrRNA基因测序结果显示ASMT基因敲除后α多样性及β多样性发生改变，细菌群落相对丰度有显著差异，持续的运动干预可以减少炎症从而调节肠道菌群稳态。结论:ASMT基因敲除可导致小鼠的抑郁行为，与TLR4/NF-κB信号通路影响神经炎症及肠道菌群有关，运动可以通过调节"微生物—肠—炎症—脑"轴改善肠道菌群紊乱进而缓解ASMT基因敲除导致的抑郁行为。
Inflammatory Mechanism of ASMT in Antidepressant Effect of Exercise
The objective of this study was to explore the effects of N-acetyl-5-hydroxytryptamine-methyltransferase(ASMT)gene knockout and exercise on depressive behavior,neuroinflammation and gut microbiota in mice.6-7 week old female wild-type mice and ASMT gene knockout mice were randomly divided into sedentary group and exercise group.After 12 weeks of aerobic treadmill training,all mice were tested for behavioral tests.During the training period,mouse feces were collected,and then the mice were anesthetized and sacrificed to collect prefrontal cortex,and hypothalamus.RT-PCR was used to detect the expression levels of pro-inflammatory and anti-inflammatory factors in the prefrontal cortex and genes related to the TLR4/NF-κB signaling pathway.Western Blotting was used to detect the protein levels of TLR4,p-IKBα,p65,p-p65 and IL-Iβ in the hypothalamus;16SrRNA gene sequencing was used to detect the composition and abundance of bacterial flora in fecal samples of mice at the fourth and eighth weeks of exercise intervention.The results showed that ASMT gene knockout could induce depressive behavior in mice,and exercise could effectively alleviate depressive behavior in mice.The levels of pro-inflammatory factors and the expression levels of TLR4/NF-κB signaling pathway increased after ASMT gene knockout.The 16SrRNA gene sequencing results of gut microbiota showed that α-diversity and β-diversity were changed after ASMT gene knockout,and the relative abundance of bacterial communities was significantly different.Continuous exercise intervention could reduce inflammation and regulate gut microbiota homeostasis.It could be concluded that ASMT gene knockout could lead to depressive behavior in mice,which was related to the TLR4/NF-κB signaling pathway affecting neuroinflammation and gut microbiota.Exercise could improve the"microbe-gut-inflammation-brain"axis and relieve the depressive behavior caused by ASMT knockout.
万方数据
维普
