Soronen Jarkko, Yki-Järvinen Hannele, Zhou You, Sädevirta Sanja, Sarin Antti-Pekka, Leivonen Marja, Sevastianova Ksenia, Perttilä Julia, Laurila Pirkka-Pekka, Sigruener Alexander, Schmitz Gerd, Olkkonen Vesa M
Genomics and Biomarkers Unit, National Institute for Health and Welfare Biomedicum, Helsinki, Finland Minerva Foundation Institute for Medical Research, Helsinki, Finland.
Minerva Foundation Institute for Medical Research, Helsinki, Finland Department of Medicine, Division of Diabetes, University of Helsinki, Helsinki, Finland.
Physiol Rep. 2016 Jan;4(1). doi: 10.14814/phy2.12661.
MicroRNAs (miRNAs) control gene expression by reducing mRNA stability and translation. We aimed to identify alterations in human liver miRNA expression/function in nonalcoholic fatty liver disease (NAFLD). Subjects with the highest (median liver fat 30%, n = 15) and lowest (0%, n = 15) liver fat content were selected from >100 obese patients for miRNA profiling of liver biopsies on microarrays carrying probes for 1438 human miRNAs (a cross-sectional study). Target mRNAs and pathways were predicted for the miRNAs most significantly upregulated in NAFLD, their cell-type-specific expression was investigated by quantitative PCR (qPCR), and the transcriptome of immortalized human hepatocytes (IHH) transfected with the miRNA with the highest number of predicted targets, miR-576-5p, was studied. The screen revealed 42 miRNAs up- and two downregulated in the NAFLD as compared to non-NAFLD liver. The miRNAs differing most significantly between the groups, miR-103a-2*, miR-106b, miR-576-5p, miRPlus-I137*, miR-892a, miR-1282, miR-3663-5p, and miR-3924, were all upregulated in NAFLD liver. Target pathways predicted for these miRNAs included ones involved in cancer, metabolic regulation, insulin signaling, and inflammation. Consistent transcriptome changes were observed in IHH transfected with miR-576-5p, and western analysis revealed a marked reduction of the RAC1 protein belonging to several miR-576-5p target pathways. To conclude, we identified 44 miRNAs differentially expressed in NAFLD versus non-NAFLD liver, 42 of these being novel in the context of NAFLD. The study demonstrates that by applying a novel study set-up and a broad-coverage array platform one can reveal a wealth of previously undiscovered miRNA dysregulation in metabolic disease.
微小RNA（miRNA）通过降低mRNA稳定性和翻译来控制基因表达。我们旨在确定非酒精性脂肪性肝病（NAFLD）患者肝脏中miRNA表达/功能的改变。从100多名肥胖患者中选取肝脏脂肪含量最高（中位肝脏脂肪30%，n = 15）和最低（0%，n = 15）的受试者，对肝脏活检组织进行miRNA芯片分析，该芯片带有针对1438种人类miRNA的探针（一项横断面研究）。预测NAFLD中上调最显著的miRNA的靶mRNA和信号通路，通过定量PCR（qPCR）研究其细胞类型特异性表达，并研究用预测靶标数量最多的miRNA即miR-576-5p转染的永生化人肝细胞（IHH）的转录组。筛选结果显示，与非NAFLD肝脏相比，NAFLD中有42种miRNA上调，2种miRNA下调。两组间差异最显著的miRNA，即miR-103a-2*、miR-106b、miR-576-5p、miRPlus-I137*、miR-892a、miR-1282、miR-3663-5p和miR-3924，在NAFLD肝脏中均上调。预测这些miRNA的靶信号通路包括与癌症、代谢调节、胰岛素信号传导和炎症相关的通路。在用miR-576-5p转染的IHH中观察到了一致的转录组变化，蛋白质免疫印迹分析显示属于几个miR-576-5p靶信号通路的RAC1蛋白显著减少。总之，我们鉴定出44种在NAFLD肝脏与非NAFLD肝脏中差异表达的miRNA，其中42种在NAFLD背景下是新发现的。该研究表明，通过应用一种新颖的研究设置和广泛覆盖的芯片平台，可以揭示代谢性疾病中大量先前未被发现的miRNA失调情况。
