乙脑病毒对基因表达谱和FOXO信号通路的调控研究

发布时间：2018-07-05 21:01

本文选题：乙脑病毒 + 内质网应激反应　；参考：《江西农业大学》2017年硕士论文

【摘要】：乙型脑炎是由乙脑病毒感染引起的中枢神经系统疾病,其突出病理特征是在脑组织内引起广泛分布的炎症和细胞死亡。目前针对此疾病的致病机制了解的很少,也无治疗此疾病的特异性药物。因此,研究乙脑病毒感染的表达谱变化和细胞死亡机制,进而开发特异性的乙型脑炎治疗药物具有重要意义。内质网应激反应是细胞内外刺激引起的从内质网到胞浆和胞核的信号传导途径,该应激反应参与调控多种疾病,如神经系统疾病、肝脏疾病,糖尿病和多种病毒性疾病等。本实验室的前期工作发现乙脑病毒可通过诱导内质网应激反应中的IRE1/JNK信号通路引起乳仓鼠肾细胞BHK-21细胞死亡。为进一步在蛋白质组水平上揭示乙型脑炎致病的分子机制,本研究分析了乙脑病毒体外感染小鼠脑神经瘤细胞Neuro2a和体内感染鼠的脑组织的基因表达谱变化,发现乙脑病毒在体外和体内均引起分子伴侣基因Hsp70表达上调,诱导内质网应激反应。乙脑病毒感染也调控其他多种细胞信号通路例如FOXO、p53、TNF、、MAPK和ECM受体相关信号通路。FOXO蛋白具有广泛的生理功能。例如调控细胞周期、衰老及凋亡。乙脑病毒感染诱导Neuro2a细胞凋亡,然而转录组测序分析、荧光定量RT-PCR和Western blot实验均表明,乙脑病毒感染48小时,FOXO1基因以及其下游促凋亡基因Bim表达出现下调,提示乙脑病毒诱导的Neuro2a细胞凋亡不是通过促凋亡基因Bim介导。FOXO1基因沉默可引起Neuro2a细胞核内FOXO1和Bim转录水平的显著降低,但Neuro-2a细胞凋亡率的大幅升高,与之相反的是,FOXO1的过表达造成上述二种蛋白表达量的显著增加和Neuro-2a细胞死亡率的明显降低。这些结果证明FOXO1可抑制Neuro-2a细胞凋亡,但不是通过调控促凋亡基因Bim。
[Abstract]:Encephalitis B is a central nervous system disease caused by encephalitis B virus infection. Little is known about the pathogenesis of the disease and no specific drug is available to treat it. Therefore, it is of great significance to study the expression profile and cell death mechanism of encephalitis B virus infection and to develop specific Japanese encephalitis drugs. Endoplasmic reticulum (ER) stress is a signal transduction pathway from endoplasmic reticulum to cytoplasm and nucleus caused by intracellular and extracellular stimuli. The stress response is involved in the regulation of many diseases, such as nervous system diseases, liver diseases, diabetes mellitus and many viral diseases. The previous work in our laboratory showed that je could induce the death of BHK-21 cells by inducing the IRE1 / JNK signaling pathway in endoplasmic reticulum stress response. In order to further reveal the molecular mechanism of encephalitis B at the proteome level, the gene expression profiles of neuro2a cells infected with Japanese encephalitis virus in vitro and the brain tissues of mice infected with Japanese encephalitis virus in vivo were analyzed. It was found that encephalitis B virus up-regulated the expression of molecular chaperone gene Hsp70 in vitro and in vivo and induced endoplasmic reticulum stress. Encephalitis B virus also regulates many other cell signaling pathways, such as FOXOp53, TNFAMAPK and ECM receptor-related signaling pathway. FOXO protein has a wide range of physiological functions. For example, regulating cell cycle, aging and apoptosis. The apoptosis of Neuro2a cells was induced by encephalitis B virus infection. However, the expression of FOXO1 gene and its downstream apoptosis-promoting gene Bim were down-regulated by transcription sequencing, fluorescent quantitative RT-PCR and Western blot assay at 48 hours after encephalitis B virus infection. The results suggested that the apoptosis induced by Japanese encephalitis virus in Neuro2a cells was not mediated by Bim-mediated. FOXO1 gene silencing induced by Japanese encephalitis virus could significantly decrease the transcription level of FOXO1 and Bim in the nucleus of Neuro2a, but the apoptosis rate of Neuro-2a cells increased significantly. In contrast, the overexpression of FOXO1 resulted in a significant increase in the expression of both proteins and a significant decrease in the cell death rate of Neuro-2a. These results suggest that FOXO1 can inhibit the apoptosis of Neuro-2a cells, but not by regulating the apoptosis-promoting gene Bim.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R373

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