持续冷暴露通过循环miRNA影响小鼠血脂代谢的实验研究

Effects of Continuous Cold Exposure on Lipid Metabolism through Circulating miRNA in Mice

目的分析持续冷暴露后小鼠血清miRNA表达特征,寻找与小鼠血脂代谢相关的差异表达miRNA。方法选用C57BL/6J雄性小鼠建立高脂饮食诱导的高脂血症模型,随机分为4℃冷暴露组和30℃等热区对照组,分别给予4℃冷暴露与30℃对照处理,检测两组血脂水平,应用二代测序对处理后的血清进行miRNAS表达谱分析,筛选显著差异表达miRNAs,同时行靶基因预测,随后进行基因本体(GO)功能注释、京都基因和基因组百科全书(KEGG)信号通路分析。结果与30℃等热区对照组相比,4℃持续冷暴露组小鼠血脂明显降低(P<0.05)。对比两组小鼠血清miRNAs表达谱,发现311条miRNA表达显著下调,其中miR-149-5p可靶向到低密度脂蛋白受体(LDLR)等多种糖脂代谢相关基因,novel_mir114、novel_mir389、novel_mir431等新预测到的未知miRNA亦靶向LDLR基因。GO和KEGG分析显示,涉及的生物学过程主要为代谢过程、胰岛素抵抗、mTOR信号通路等。结论持续冷暴露可使小鼠血脂水平下降且血清外泌体miRNA表达模式发生显著改变。

Objective To analyze the effect of continuous cold exposure,and the differentially expressed miRNAs related to blood lipid metabolism in mice were searched.Methods C57BL/6J mice were fed with a high-fat diet to establish the hyperlipidemia model,and them mice were treated with cold exposure at 4℃and 30℃,respectively.The blood lipid levels were detected,and the next-generation sequencing was used to analyze the miRNAs,expression profile of the treated serum.Significantly differentially expressed miRNAs were screened and target genes were predicted,followed by Gene Ontology(GO)functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway analysis.Results The blood lipids of mice exposed to continuous cold at 4℃were significantly decreased.Comparing the expression profiles of serum miRNAs in the continuous cold exposure group and the control group,it was found that the expression of 311 miRNAs was significantly down-regulated.Among them,miR-149-5p could predict a variety of glycolipid metabolism-related genes such as low density lipoprotein receptor(LDLR),etc.The newly predicted unknown miRNAs such as novel_mir114,and novel_mir389,novel_mir431 which targeted the LDLR gene.GO and KEGG analysis showed that the biological processes involved were mainly metabolic process,insulin resistance,mTOR signaling pathway,etc.Conclusion Continuous cold exposure can reduce the blood lipid level and significantly change the expression pattern of serum exosomal miRNA in mice.