miR1934，一种脂联素特异性调控的靶microRNA，在肥胖小鼠的脂肪组织中表达降低

miR1934，an adiponectin specially-regulated microRNA，is downregulated in adipose tissues of obese mice

摘要:

目的：脂联素（Adiponectin，ApN）是脂肪细胞分泌的最主要抗炎细胞因子。利用ApN过表达 （ApN-Over）和ApN基因敲除（ApN-KO）小鼠模型筛选出ApN的靶microRNAs（miRNAs），以探寻脂肪组织新的具抗炎作用的功能性miRNAs。方法：给予4周龄雄性ApN-Over小鼠和其野生型对照小鼠高脂饮食6周后，分离提取腹股沟脂肪组织。采用miRNA 微陈列芯片筛选出两组小鼠脂肪组织间表达有差异的miRNAs；在ApN-Over，ApN-KO和高脂（HFD）诱发的肥胖小鼠脂肪组织中用定量PCR验证上述筛选出的差异miRNAs；采用生物信息学数据库预测miRNAs的靶基因。结果：ApN-Over小鼠脂肪组织中有12个miRNAs的表达与野生对照小鼠显著不同；定量PCR验证结果显示有3个miRNAs确实受到ApN的调节：miR532-5p的表达被ApN下调，而miR883b-5p 和miR1934 的表达被上调；其中仅有miR1934在ApN-KO小鼠的脂肪组织中明显下降，与ApN-Over小鼠脂肪组织呈现相反的表达模式；miR1934在HFD诱发的肥胖小鼠的内脏脂肪组织中的表达明显低于普通饮食喂养的小鼠（1.00±0.22 vs. 0.54±0.13，P=0.04）。生物信息数据库预测出miR1934有53个靶基因，其中2个靶基因为丝氨酸/苏氨酸激酶3 （serine/threonine kinase 3，STK3）和趋化因子（C-C motif）配体[chemokine （C-C motif）ligand，CCL19]，二者均为参与JNK信号通路的分子。结论：miR1934是体内脂肪组织中受脂联素特异性调节的miRNA。肥胖小鼠内脏脂肪组织中miR1934的表达显著降低；生物信息学分析初步发现miR1934可能参与调节JNK信号通路。因此脂联素特异性的靶miR1934有可能为改善脂肪组织炎症及其相关的代谢异常提供新的治疗前景。

Abstract:

Objective：Mice over-expressing ApN specifically in adipose tissues（AT，ApN-Over） and the mice knocking-out ApN （ApN-KO） were used to identify microRNAs（miRNAs） targeted by ApN in AT. Methods：Male ApN-Over mice，ApN-KO mice and C57/Bl6J mice fed with high-fat diet（HFD） were used. miRNA expression profiling was performed by using microRNA arrays. The expressions of miRNAs and adipokines were quantified by real-time PCR. The gene targets of miR1934 were predicted by bioinfor－matic data base. Results：There were 12 miRNAs differently expressed between AT of ApN-Overex mice and wild-type mice. By PCR validation，the expression of miR532-5p was down-regulated，while that of miR883b-5p and miR1934 was up-regulated in AT of ApN-Over mice. Moreover，the expression of miR1934 in AT of ApN-KO mice was down-regulated，exhibiting a reverse expression pattern compared to ApN-Over mice. The expression of miR1934 was significantly lower in epididymal AT of HFD-induced obese mice than that in chow diet-fed mice（1.00±0.22 vs. 0.54±0.13，P=0.04）. The predicted gene targets of miR-1934，serine/threonine kinase 3（STK3） and chemokine（C-C motif） ligand（CCL19），were annotated to be involved in Jun N-terminal kinases（JNK） signal－ing pathway. Conclusion：We identified a novel miRNA，miR-1934，which was up-regulated by ApN in AT in vivo. The expression of miR1934 was decreased in visceral AT of obese mice. The possible roles of miR-1934 may be involved in the JNK signaling pathway. This novel miRNA may open new therapeutic perspectives for controlling the pro-inflammatory state of obese AT.