miR-19b与TGF-β1交互作用对肝星状细胞增殖影响机制研究

发布时间：2018-04-21 06:01

本文选题：囊型包虫病 + 肝纤维化　；参考：《新疆大学》2014年硕士论文

【摘要】：棘球蚴病（Echinococcosis），又称为包虫病，是由棘球绦虫的幼虫寄生于宿主体内导致的一种人畜共患寄生虫疾病，其中，95%的病例为细粒棘球绦虫（Echinococcus granulosus, E.g）感染所致的囊型包虫病（Cystis Echinococcosis,CE）该病呈全球分布，后果较为严重。microRNA隶属于非编码小RNA（smallnoncoding RNAs），长度为18-23个核苷酸，它可以通过mRNA剪切或与靶基因mRNA结合而干扰其转录过程来调控靶基因在蛋白水平的表达。现已在哺乳动物鉴定出约1400个miRNA，每个miRNA可以影响数百个基因的转录，而每个mRNA也可被多个miRNA调节。越来越多的研究显示，miRNA在肝脏的分化及其形态和功能维持和包括寄生虫感染在内的肝脏疾病的发生发展密切相关。现有研究显示miR-19b在肝星状细胞HSC活化进程中表达量下调，与之相似的是，miR-19b在肝纤维化患者的肝脏组织和肝纤维化的小鼠模型中的表达下调；miR-19b过表达可通过抑制其靶基因TGFβRII的表达而达到抑制TGF-β信号通路的效果，进而抑制细胞中α-SMA和胶原蛋白的表达。探讨miR-19b在囊性包虫病患者肝脏组织中的表达情况，，对于囊性包虫病发病机制的研究有重要的理论和临床意义。我们通过QRT-PCR检测α-SMA、COL1A1、COL3A1、TGFβRII及miR-19b在囊性包虫病患者肝脏组织中的表达；并检测了HCF外源刺激对人肝星状细胞LX-2增殖的影响，最后通过脂质体2000转染miR-19b及miRNA-NC分析miR-19b对HCF所致LX-2细胞增殖过程中的调控。结果显示囊性包虫病患者肝脏组织中，α-SMA、COL1A1、COL3A1和TGFβRII mRNA在病灶近旁部位的表达量较远端组织增加；miR-19b在病灶近旁部位的表达较远端组织的表达量下降，且miR-19b表达量与COL1A1的表达量负相关。向体外培养的LX-2细胞中添加外源HCF发现，HCF可通过促进LX-2细胞由G0/G1期向S期的转变而促进细胞增殖，与此同时，HCF外源刺激可促进α-SMA、COL1A1、COL3A1和TGFβRII mRNA及蛋白水平表达的增加。miR-19b过表达可抑制LX-2细胞的增殖，并通过阻碍TGF-β信号传递而达到降低COL1A1和COL3A1沉积的效果，从而延缓或逆转纤维化的进程。因此， miR-19b可能成为囊性包虫病治疗的潜在靶点。
[Abstract]:Echinococcus coensis, also known as echinococcosis, is a zoonotic parasitic disease caused by the larva of Echinococcus granulosus. Among them, 95% of the cases were caused by Echinococcus granulosus (E.g) infection. Cystis Echinococcus coensis (CEE) was a global disease with serious consequences. MicroRNAs belonged to a small, non-coding RNA(smallnoncoding, RNAsN, with a length of 18-23 nucleotides. It can interfere with the transcriptional process of target gene by mRNA splicing or binding with target gene mRNA to regulate the expression of target gene at protein level. About 1400 miRNAs have been identified in mammals, each miRNA can affect the transcription of hundreds of genes, and each mRNA can also be regulated by multiple miRNA. More and more studies have shown that miRNA is closely related to liver differentiation, morphological and functional maintenance, and the occurrence and development of liver diseases including parasitic infection. Current studies have shown that miR-19b expression is down-regulated in the process of HSC activation in hepatic stellate cells. Similarly, the down-regulated expression of miR-19b in liver tissues of patients with liver fibrosis and mouse model of liver fibrosis can inhibit the signal pathway of TGF- 尾 by inhibiting the expression of its target gene TGF 尾 RII. Furthermore, the expression of 伪 -SMA and collagen was inhibited. To investigate the expression of miR-19b in liver tissue of patients with cystic hydatid disease, it is of great theoretical and clinical significance to study the pathogenesis of cystic hydatid disease. The expression of TGF- 尾 RII and miR-19b in liver tissues of patients with cystic hydatid disease was detected by QRT-PCR, and the effect of exogenous stimulation of HCF on LX-2 proliferation of human hepatic stellate cells was detected. Finally, the regulation of miR-19b on the proliferation of LX-2 cells induced by HCF was analyzed by transfection of liposome 2000 into miR-19b and miRNA-NC. The results showed that the expression of 伪 -SMA-COL1A1 and TGF 尾 RII mRNA in liver tissues of patients with cystic hydatid disease was higher than that in distal tissues, and the expression of miR-19b was negatively correlated with the expression of COL1A1. It was found that the addition of exogenous HCF to LX-2 cells in vitro could promote the proliferation of LX-2 cells by promoting the transformation of LX-2 cells from G0/G1 phase to S phase. At the same time, the overexpression of 伪 -SMA-COL1A1 and TGF 尾 RII mRNA and protein could inhibit the proliferation of LX-2 cells and reduce the deposition of COL1A1 and COL3A1 by blocking TGF- 尾 signal transduction. Thus delaying or reversing the process of fibrosis. Therefore, miR-19b may be a potential target for the treatment of cystic hydatid disease.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R532.32

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