CCl4诱导的小鼠纤维化肝组织微小RNA差异表达谱及初步功能分析

 目的：应用微小RNA(miRNA)芯片技术研究miRNAs在四氯化碳（CCl4）诱导的小鼠纤维化肝脏中的差异表达谱，并基于基因本体论（gene ontology，GO)分析及信号转导通路分析发现差异miRNAs的主要功能。方法：实验分为正常组及模型组，皮下注射 CCl4复制小鼠肝纤维化模型；应用Agilent 小鼠 miRNA 寡核苷酸基因芯片检测各组肝脏miRNA表达谱。用随机方差模型t检验筛选2组间的差异miRNAs，并预测其靶基因。对靶基因进行GO分析及信号转导通路分析发现差异miRNAs发挥的主要功能。结果：正常组与模型组间共筛选出39个差异miRNAs，其中模型组较正常组上调的23个，下调的16个。GO分析及信号转导通路分析结果提示差异miRNAs可能调控的靶基因及其参与的生物学功能包括细胞的增殖与活化、细胞凋亡、细胞周期、细胞黏附、细胞迁移、炎症反应、转化生长因子β（TGF-β）/Smads信号转导通路、Wnt受体信号转导通路、蛋白代谢过程的调控等。GO分析发现关键的上调miRNA包括mmu-miR-322、mmu-miR-15b、mmu-miR-195、mmu-miR-200b、mmu-miR-214等,关键的下调miRNA包括mmu-miR-16、mmu-miR-130a、mmu-miR-101b、mmu-miR-30a和mmu-miR-30e等。对显著性GO与显著性信号通路所属的靶基因取交集，对网络中miRNA在网络中的调控地位进行评价，结果发现关键的上调miRNAs包括mmu-miR-200b、mmu-miR-322、mmu-miR-106b、mmu-miR-23a、mmu-miR-15b等,关键的下调miRNAs包括mmu-miR-16、mmu-miR-30e、mmu-miR-30c、mmu-miR-30a、mmu-miR-130a等。结论：纤维化肝组织miRNAs表达较正常肝组织发生明显变化；肝纤维化形成的各个环节，包括细胞的增殖与活化、细胞黏附、细胞凋亡、细胞迁移与分化、物质代谢、TGF-β信号通路等都可能受miRNAs的调控。

Functional analysis of differential microRNA expression profile in mouse fibrotic liver tissues induced by CCl4

AIM:To discover the expression profile of microRNAs (miRNAs) in mouse fibrotic liver tissues induced by carbon tetrachloride (CCl4), and to investigate the functions of these differential miRNAs based on the gene ontology (GO) analysis and KEGG Pathway analysis. METHODS:The mice were randomly divided into normal group and model group. Liver fibrosis was induced by subcutaneous injection of CCl4. miRNA expression profile of the liver tissues was assayed by a mouse miRNA microarray (Agilent 12.0). The differential expression of miRNAs between the normal and model mice was screened, and GO analysis and KEGG Pathway analysis were performed to determine the functions of these differential miRNAs. RESULTS:Thirty-nine miRNAs with differential expression were discovered in the model mice compared with the normal mice, among which 23 were up-regulated and 16 were down-regulated. GO analysis and KEGG Pathway analysis indicated that most pathological processes of liver fibrosis regulated by miRNAs included cell proliferation and activation, cell apoptosis, cell cycle, cell adhesion, inflammatory reaction, cell migration, transforming growth factor β (TGF-β) signaling pathway, Wnt signaling pathway and proteometabolism process. GO analysis revealed that the key up-regulated miRNAs were mmu-miR-322, mmu-miR-15b, mmu-miR-195, mmu-miR-200b and mmu-miR-214, and the key down-regulated miRNAs were mmu-miR-16, mmu-miR-130a, mmu-miR-101b, mmu-miR-30a and mmu-miR-30e. Analyzing the target genes screened out by GO analysis and Pathway analysis simultaneously, we found that the key up-regulated miRNAs included mmu-miR-200b, mmu-miR-322, mmu-miR-106b, mmu-miR-23a and mmu-miR-15b, and the key down-regulated miRNAs included mmu-miR-16, mmu-miR-30e, mmu-miR-30c, mmu-miR-30a and mmu-miR-130a. CONCLUSION: Differential expression of miRNAs is discovered in mouse fibrotic liver tissues induced by CCl4 compared with the normal liver tissues. Most of the pathological processes involved in liver fibrosis may be regulated by miRNA, such as cell proliferation and activation, cell adhesion and apoptosis, cell migration and differentiation, metabolism, TGF-β receptor signaling pathway and so on.