外源铜离子对斑马鱼造血系统的氧化应激效应

发布时间：2018-07-05 07:09

本文选题：铜离子 + 氧化应激　；参考：《华中农业大学》2017年硕士论文

【摘要】：铜(Cu,copper)是人体必需的微量元素,作为辅基参与合成多种生物酶。人体内铜代谢紊乱会引发多种疾病。斑马鱼(Danio rerio)是一种重要的模式水生生物,在生态毒理学、发育生物学、分子生物学等领域应用广泛,诸如评价环境胁迫因子、构建疾病病理模型。本论文研究了铜离子暴露引起的斑马鱼造血系统和相关调控机制的功能基因表达、生理代谢调节的变化。旨在探讨铜离子对胚胎发育早期及成体期造血系统的相关影响及其机制,为促进铜离子机体代谢、铜离子代谢相关的血液类疾病、肿瘤等癌细胞增生类疾病的预防研究提供新方法。主要结果如下:1.铜离子对斑马鱼造血系统发育和再生的影响通过分析外源铜离子对斑马鱼胚胎造血发生的影响,发现铜处理胚胎红系细胞(RBC)的基因表达增强、造血干细胞(HSC)标记基因及其相关的调控信号Notch和Wnt信号通路因子表达减弱。铜处理成鱼的外周和肾脏血流式细胞分析结果显示,处理成鱼的肾脏血、外周血的细胞分化程度均明显增强。结果显示,外源铜离子破坏了鱼类胚胎造血系统发育及其成体造血细胞的再生及平衡。2.铜离子激发斑马鱼的氧化应激通过基因表达谱分析、转录水平验证、活性氧(ROS)含量检测,发现铜处理胚胎氧化应激过程的基因表达增强、活性氧含量增加,氧结合和氧转运基因的表达增强。此外,预先添加抗氧化剂可以高效恢复铜处理胚胎中氧化还原类反应的基因表达、恢复活性氧含量。3.铜调控斑马鱼造血系统发育和再生的作用机制抗氧化剂还可以恢复红系细胞的基因表达、血红蛋白的合成量,协助机体完成过量铜离子的代谢、恢复胚胎内的铜离子含量。全基因组甲基化分析发现,造血干细胞关键基因在启动子预测区的甲基化修饰增强。外源铜离子是通过激活氧化应激基因、促进活性氧分子的合成,增强造血系统的红系分化、扰乱铜代谢平衡的。添加外源抗氧化剂,不仅可以恢复造血系统的红系分化,而且可恢复机体铜代谢平衡。铜可能通过氧化应激反应和甲基化修饰DNA分子,调控造血系统的分化和再生。
[Abstract]:Copper (copper) is a necessary trace element in human body, which is involved in the synthesis of a variety of biological enzymes as an auxiliary group. Disorders of copper metabolism in the human body can lead to many diseases. Zebrafish (Danio rerio) is an important model aquatic organism, which is widely used in ecotoxicology, developmental biology, molecular biology and so on. In this paper, the changes of functional gene expression and physiological metabolic regulation in zebrafish hematopoietic system and related regulatory mechanisms induced by copper ion exposure were studied. The aim of this study was to investigate the effects of copper ion on hematopoietic system in early embryonic and adult stages and its mechanism. In order to promote the metabolism of copper ions, the related blood diseases related to copper ion metabolism were studied. A new method is provided for the prevention of cancer cell proliferation diseases such as tumor. The main results are as follows: 1. Effects of copper ions on the development and regeneration of hematopoietic system of zebrafish by analyzing the effects of exogenous copper ions on embryonic hematopoiesis of zebrafish, it was found that the gene expression of erythroid cells (RBC) of zebrafish embryos treated with copper was enhanced. Hematopoietic stem cells (HSC)-labeled genes and their associated regulatory signaling Notch and Wnt signal pathway factors were down-regulated. The results of peripheral and renal blood flow cytometry analysis showed that the differentiation degree of peripheral blood cells of adult fish treated with copper was significantly increased. The results showed that exogenous copper ions destroyed the development of hematopoietic system of fish embryo and the regeneration and balance of adult hematopoietic cells. Oxidative stress induced by copper ions in zebrafish was detected by gene expression profiling, transcription level verification and reactive oxygen species (Ros) content detection. It was found that the expression of genes increased and the content of reactive oxygen species increased in the process of oxidative stress induced by copper. The expression of oxygen binding and oxygen transport genes was enhanced. In addition, pretreatment with antioxidants could effectively restore the gene expression of redox reaction and the content of reactive oxygen species (Ros) in copper treated embryos. The mechanism of copper regulating the development and regeneration of hematopoietic system in zebrafish, antioxidants can also restore gene expression and hemoglobin synthesis of erythroid cells, assist the body to complete the metabolism of excessive copper ions, and recover the copper ion content in embryos. Genomic methylation analysis showed that the methylation modification of hematopoietic stem cell key genes in the promoter predictive region was enhanced. Exogenous copper ions promote the synthesis of reactive oxygen species by activating oxidative stress genes, enhance the erythroid differentiation of hematopoietic system, and disturb the balance of copper metabolism. The addition of exogenous antioxidants can not only restore the erythroid differentiation of hematopoietic system, but also restore the balance of copper metabolism. Copper may regulate the differentiation and regeneration of hematopoietic system by oxidative stress and methylation of DNA molecules.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X503.225

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