成纤维细胞生长因子21糖尿病引发的非酒精性脂肪肝性肝炎中的作用及其机制研究

发布时间：2018-03-15 17:39

本文选题：成纤维细胞生长因子21　切入点：非酒精性脂肪性肝炎　出处：《吉林大学》2017年博士论文　论文类型：学位论文

【摘要】：背景:糖尿病是一种慢性疾病,90%以上为II型糖尿病。长期糖代谢紊乱,会严重影响机体的脂质代谢,致使脂蛋白合成出现障碍,导致脂肪酸在肝脏内大量存积,形成非酒精性脂肪肝性肝炎(NASH),肝脏长期被慢性炎症反复刺激成为肝癌变的驱动因素。随着当今人们生活方式的改变,如高脂肪高热量饮食、多坐少动等,糖尿病相关性肝癌的发生率也逐年上升。据流行病学调查显示,糖尿病患者患肝细胞癌的风险比常人高3倍。然而有70%的糖尿病患者患有不同程度的非酒精性脂肪肝病(NAFLD),者被认为是肝脏代谢综合征的表现.Chen等人的研究中显示,在2型糖尿病以及非酒精性肝病患者内体的FGF21的浓度是升高的[1]。由脂肪引发的炎症以及胰岛素抵抗,可能是非酒精性脂肪性肝炎的形成以及发展为肝细胞癌重要机制。FGF21主要在肝脏中特异性表达。已有研究表明,FGF21是一种非常有意义的保护糖代谢稳态的细胞因子,其生物学功能主要体现在糖脂代谢调控方面,具有与胰岛素类似的作用[2]。因此本课题通过建立FGF21基因敲除糖尿老鼠和高脂喂养老鼠模型,并通过检测炎症程度,代谢异常水平,细胞性活动,以及Wnt/β-catenin信号通路和上皮细胞向间质细胞的转化(EMT)来探讨FGF21对糖尿病小鼠非酒精性脂肪肝炎的发生以及转化为肝细胞癌(HCC)过程中的作用。目的:观察FGF21在由糖尿病引发的非酒精性肝炎小鼠体内的作用及其机制。方法:构建通过糖尿病以及高脂喂养诱导的非酒精性肝炎FGF21基因敲除小鼠模型,分别建立野生型对照组(WT-CT),野生型糖尿病组(WT-DM),野生型高脂组(WT-HFD),FGF21基因敲除对照组(KO-CT),FGF21基因敲除糖尿病组(KO-DM),FGF21基因敲除高脂组(KO-HFD)。应用Western blot,RT-PCR,TUNEL,生化分析,免疫组化、和HE染色等方法分别通过观察小鼠体内炎症程度,脂代谢水平,细胞性活动,上皮细胞-间充质细胞转换,以及Wnt/β-catenin信号通路等方面探讨其作用机制。结果:成功构建糖尿病以及高脂喂养诱导的非酒精性肝炎FGF21基因敲除小鼠模型.我们的结果证明:KO-DM小鼠的肝脏损伤程度,脂代谢异常水平,肝细胞增殖,凋亡水平显著高于WT-DM小鼠(P0.05)。并且上调了E-cadherin,Vinmentin,Fibronectin,β-catenin,GSK-3β等蛋白水平,从而激活了Wnt/β-catenin信号通路并且引发了EMT的发生。在高脂喂养诱导的非酒精性肝炎FGF21基因敲除小鼠模型中的肝脏损伤程度,以及脂代谢异常水平明显高于对照组。结论:在糖尿病引发的非酒精性脂肪肝炎的微环境中,FGF21基因的缺失导致小鼠肝脏脂代谢系统进一步紊乱,并激活了Wnt/β-catenin信号通路以及EMT的发生,从而促进了肝细胞癌(HCC)干细胞的形成。
[Abstract]:Background: diabetes is a chronic disease with more than 90% of type II diabetes. Long-term disorder of glucose metabolism can seriously affect lipid metabolism of the body and lead to an obstacle of lipoprotein synthesis, resulting in a large accumulation of fatty acids in the liver. The liver is stimulated by chronic inflammation for a long time to become the driving factor of liver cancer. With the change of people's lifestyle nowadays, such as high-fat and high-calorie diet, more sitting and less exercise, etc. The incidence of diabetes-associated liver cancer has also increased year by year. The risk of hepatocellular carcinoma in diabetic patients is three times higher than that in normal people. However, 70% of diabetics have varying degrees of nonalcoholic fatty liver disease, which is thought to be a manifestation of hepatic metabolic syndrome. Chen et al. In patients with type 2 diabetes and non-alcoholic liver disease, FGF21 concentrations were elevated [1]. Inflammation induced by fat and insulin resistance. It may be the formation of non-alcoholic fatty hepatitis and its development into an important mechanism of hepatocellular carcinoma. FGF21 is mainly expressed specifically in the liver. It has been shown that FGF21 is a very meaningful cytokine that protects the homeostasis of glucose metabolism. Its biological function is mainly embodied in the regulation of glycolipid metabolism and has a similar effect to insulin [2] .Therefore, we have established FGF21 gene knockout mice and hyperlipidemic mice models, and detected the degree of inflammation and the abnormal level of metabolism. Cellular activity, And the Wnt/ 尾 -catenin signaling pathway and the transformation of epithelial cells to mesenchymal cells to explore the role of FGF21 in the development of non-alcoholic fatty liver disease and its transformation into hepatocellular carcinoma in diabetic mice. Objective: to observe the role of FGF21 in the development of diabetes mellitus. Methods: the mouse model of FGF21 gene knockout induced by diabetes mellitus and high fat feeding was established. In wild type control group, wild-type diabetes group and wild type hyperlipidemic group were established respectively. Western blotRT-PCRLL, biochemical analysis, immunohistochemistry, FGF21 gene knockout control group, KO-CTU FGF21 gene knockout control group, KO-DMG21 gene knockout FGF21 gene knockout group, KO-HFD-FGF21 gene knockout group, KO-HFDL, biochemical analysis, immunohistochemistry, FGF21 gene knockout control group, KO-HFD-FGF21 gene knockout control group, wild-type diabetes mellitus group, wild type diabetes group and wild type high-fat group, respectively. The degree of inflammation, lipid metabolism, cellular activity, epithelial-mesenchymal cell transformation were observed by HE staining in mice. The mechanism of Wnt/ 尾 -catenin signaling pathway was discussed. Results: the FGF21 gene knockout mice induced by diabetes mellitus and high fat feeding were successfully constructed. The levels of lipid metabolism abnormality, hepatocyte proliferation and apoptosis were significantly higher than those in WT-DM mice (P 0.05), and the levels of E-cadherin Vinmentinine fibronectin, 尾 -catenin GSK-3 尾 were up-regulated. Thus activating the Wnt/ 尾 -catenin signaling pathway and triggering the occurrence of EMT. The degree of liver damage in high-fat feeding induced non-alcoholic hepatitis FGF21 knockout mice, Conclusion: the absence of FGF21 gene in the microenvironment of non-alcoholic fatty liver disease caused by diabetes may lead to a further disorder of the lipid metabolism system in the liver of mice. It also activates Wnt/ 尾 -catenin signaling pathway and the occurrence of EMT, thus promoting the formation of hepatocellular carcinoma (HCC) stem cells.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R575;R587.2

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