HEPC1和HEPC2对小鼠巨噬细胞铁贮存与释放影响的实验研究

发布时间：2018-04-25 12:45

本文选题：Hepcidin + 巨噬细胞　；参考：《第三军医大学》2005年硕士论文

【摘要】：Hepcidin(hep=hepatic,cidin=antimicrobial activity,简称HEPC 或HAMP)是近年来发现的第一种由哺乳动物肝脏特异性合成与分泌的抗菌肽,从鱼类到人类众多的脊椎动物肝脏中均检测到其同源基因,具有很高的保守性。其成熟肽只有20 几个氨基酸残基,且在保守位置上都有8 个半胱氨酸并形成4 个链内二硫键。人和其它动物只有一个基因拷贝,但小鼠7 号染色体上有2 个拷贝,分别称为hepc1 和hepc2。Hepcidin 除具有抗菌活性外还参与铁代谢,其在铁稳态的维持过程中起着重要的调控作用,并参与和介导多种铁代谢紊乱性疾病。许多研究表明,hepcidin在体内具有抑制小肠铁吸收、胎盘铁转运以及促进铁在网状内皮系统中滞留的作用。但hepcidin在体内的这种作用是它的直接作用还是通过其它机制或蛋白然后再作用于小肠和网状内皮系统的间接作用,以及它的具体作用机制都还不明了。已有人研究体外hepcidin对分离的大鼠肠段和肠上皮细胞系Caco-2细胞铁吸收的作用,并证明体外hepcidin可直接抑制分离的大鼠肠段和Caco-2细胞的铁吸收,但其作用机制尚未阐明。体外hepcidin是否对网状内皮系统和单核-巨噬细胞铁滞留有影响目前还不清楚,但它的阐明无疑对进一步探讨hepcidin通过调节网状内皮系统铁代谢来维持铁稳态的机制,以及研究hepcidin与血色素沉着病、慢性病贫血等疾病所出现的特征性网状内皮系统铁紊乱的关系都有很重要的指导作用。由于网状内皮系统(即单核-巨噬细胞系统,由骨髓到血液以及定居于组织的各发育阶段的单核细胞和巨噬细胞组成)不象其它实体组织或器官如小肠等,不能完全分离和模拟,但巨噬细胞在多数情况下能很好地反映体内网状内皮系统,因此它也被常用来作为网状内皮系统的体外模型。为此,我们以小鼠巨噬细胞系作为体内网状内皮系统的体外模型设计本实验,观察了体外HEPC1和HEPC2对两株起源不同的小鼠巨噬细胞系Ana-1(起源于小鼠正常或遗传变异的巨噬细胞系)和RAW264.7(起源于小鼠肿瘤的单核巨噬细胞系)铁贮存与释放的影响,为进一步探讨体内hepcidin促进网状内皮系统铁滞留的机制打下基础。研究目的构建小鼠HEPC1 和HEPC2 基因的真核表达载体;观察体外HEPC1 和HEPC2 对小鼠巨噬细胞铁贮存与释放的影响,为探讨hepcidin 作用网状内皮系统促进铁滞留的机制打下基础。
[Abstract]:Hepatitis C (HEPC) is the first antimicrobial peptide specifically synthesized and secreted by mammalian liver in recent years. Homologous genes have been detected from fish to human vertebrate liver. Its mature peptide has only 20 amino acid residues and has 8 cysteine and 4 intrachain disulfide bonds in conserved position. Human and other animals have only one copy of the gene, but there are two copies on chromosome 7 of mice, hepc1 and hepc2.Hepcidin are involved in iron metabolism in addition to their antibacterial activity, which plays an important role in the maintenance of iron homeostasis. And participate in and mediate a variety of iron metabolism disorders. Many studies have shown that hepcidin inhibits iron absorption in the small intestine, placental iron transport and the retention of iron in reticular endothelial system. But it is not clear whether hepcidin acts directly in vivo or indirectly through other mechanisms or proteins and then acts on the small intestine and reticular endothelial system, as well as its specific mechanism. The effect of hepcidin on iron absorption in isolated rat intestinal segment and intestinal epithelial cell line Caco-2 has been studied, and it has been proved that hepcidin in vitro can directly inhibit iron absorption in isolated rat intestinal segment and Caco-2 cell line, but the mechanism has not been clarified. It is not clear whether hepcidin can affect the retention of iron in reticular endothelial system and monocyte-macrophage in vitro, but its elucidation will undoubtedly further explore the mechanism of hepcidin maintaining iron homeostasis by regulating iron metabolism in reticuloendothelial system. It is important to study the relationship between hepcidin and iron disturbance of reticuloendothelial system in patients with hemoglobin and anemia of chronic diseases. Because the reticular endothelial system (monocyte-macrophage system), consisting of bone marrow to blood and monocytes and macrophages at various stages of development settled in tissues, is not like other solid tissues or organs such as the small intestine. Macrophages can not be completely separated and simulated but in most cases macrophages can well reflect the reticuloendothelial system in vivo so it is often used as an in vitro model of reticuloendothelial system. Therefore, we designed the mouse macrophage cell line as an in vitro model of reticular endothelial system in vivo. The effects of HEPC1 and HEPC2 on iron storage and release of two murine macrophage cell lines Ana-1 (derived from normal or genetic variation in mice) and RAW264.7 (mononuclear macrophages derived from mouse tumors) were investigated in vitro. To further explore the mechanism of hepcidin in promoting iron retention in reticular endothelial system. Research purpose The eukaryotic expression vectors of mouse HEPC1 and HEPC2 genes were constructed, and the effects of HEPC1 and HEPC2 on the iron storage and release of mouse macrophages in vitro were observed, which laid a foundation for the study of the mechanism of the role of hepcidin in promoting iron retention in reticuloendothelial system.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R341

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