酒精暴露的阿尔茨海默病小鼠中肝源性外泌体miR-122介导肝-脑交流与神经炎症
Hepatocyte-derived exosomal miR-122 mediates liver-to-brain crosstalk and neuroinflammation in alcohol-exposed Alzheimer’s disease mice
摘要
研究在APP/PS1阿尔茨海默病小鼠中评估反复暴饮对肝、脑的影响。酒精暴露引起肝损伤及肝脑促炎因子升高,增加小细胞外囊泡(sEV)生成与释放,其富含肝细胞来源的miR-122-5p;该miRNA可在脑内检出,并被小胶质细胞摄取。体外实验显示酒精处理肝细胞来源sEV可增强BV-2小胶质细胞对LPS的炎症反应,miR-122-5p模拟物部分重现、抑制剂逆转该效应,且靶基因ADAM10下降。结论提示酒精诱导的肝源性sEV可能经miR-122-5p参与AD神经炎症。
原文摘要
Neuroinflammation and microglial activation are common features in Alzheimer’s disease (AD) and excessive alcohol consumption. Alcohol induces liver damage and inflammation, and altered serum aminotransferases have been reported in patients with AD. Small extracellular vesicles (sEVs) and their cargo are emerging as mediators of intercellular communication in AD and alcohol-induced liver injury. However, the effects of alcohol use on AD progression remain to be elucidated. In this study, we evaluated the effects of repeated binge drinking on the liver and brain in the APP/PS1 mouse model of AD. Alcohol-exposed APP/PS1 mice showed elevated serum alanine aminotransferase levels, indicating liver injury absent in controls, along with increased pro-inflammatory cytokine expression in both liver and brain. Alcohol increased the biogenesis and release of sEVs in AD mice and in mouse hepatocytes. These sEVs were enriched in mature miR-122-5p that is predominant in hepatocytes. In vivo, miR-122-5p was detected in the brain of alcohol-exposed AD mice suggesting EV-mediated miR-122-5p transfer to the brain. Microglial uptake of hepatocyte-derived sEVs was confirmed in vitro. sEVs from alcohol-treated hepatocytes sensitized BV-2 microglia to LPS stimulation, significantly enhancing CCL2, CXCL2, CCL3, and TNF-α production. Transfection of microglia with a miR-122-5p mimic partially recapitulated the pro-inflammatory sensitization by sEVs from alcohol-exposed hepatocytes, which was reversed by miR-122-5p inhibitor delivery. ADAM10, a miR-122-5p target, was reduced in both wild-type and AD brains after alcohol exposure, with cell-specific effects. These results suggest that alcohol-induced hepatocyte-derived sEVs may modulate liver-to-brain signaling via miR-122-5p and contribute to neuroinflammation in AD.
推荐理由:机制设计较完整,但主题为酒精相关肝-脑轴与神经炎症,与生殖医学、辅助生殖及胚胎多组学无直接关联,本领域读者无需优先阅读。
文献解读
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