游离的LIFα胞内功能片段对HL-60细胞的生长调节

发布时间：2018-11-03 13:25

【摘要】：白血病抑制因子(LIF)是一种多效性细胞因子,作用于多种细胞组织发挥不同的生物学作用,广泛调节细胞的生长、增殖和分化。如抑制胚胎干细胞的体外分化;刺激血小板生成,造血细胞增殖;促进成骨细胞增殖;促进神经原形成,肌肉卫星细胞的增殖,参与神经肌肉修复;参与肝的急性期反应,参与炎症的生理病理过程等。这些生物学效应有赖于其结合靶细胞膜上的LIF受体α亚基(gp190),与另一亚基(gp130)形成异源性二聚体,激活下游信号转导通路。gp190(LIFRα亚基)是低亲和力的LIF特异性受体,属于造血细胞素受体超家族,缺乏内生激酶的活性。生理状态下存在可溶性LIFR和跨膜LIFR。可溶性受体,游离于胞外,无跨膜区和细胞内区,对LIF发挥的正常生理效应有拮抗效应。跨膜LIFR(gp190)胞内区含三个功能域——BOX1、2、3。YXXQ序列位于远膜端(Y酪氨酸,X任意氨基酸,Q谷氨酰胺),与STAT3的SH2位点特异性识别结合。细胞内是否存在胞内区游离受体,胞内区受体游离后如何影响信号传递,发挥其生物学效应?有关膜受体信号启动位点的游离多肽对细胞增殖分化的影响已有报道,提示我们,单一亚基的单一信号启动位点在离膜状态下完全能够在细胞内启动相应的信号转导通路。LIF信号传导激活JAK-STAT途径和RAS-MAPK途径,我们前期研究根据gp190细胞内区的不同功能域分别设计了两种小分子——190CT2+3(含BOX2+3)和190CT3(含BOX3),发现gp190细胞内区的多个功能域成为游离多肽在细胞内存在时,对细胞分化有不同的影响,激活不同的信号分子。为进一步验证前期工作,研究发生机制,本研究成功获得了重组190CT2+3和190CT3两种白血病HL-60细胞株,并进一步对190CT3的YXXQ基团定点突变研究相关信号转导通路,发现稳定表达重组目的基因(190CT2+3和190CT3)的肿瘤细胞,增殖均受到抑制,促进细胞成熟分化,JAK/STAT3通路激活;通过该研究,我们明确了gp190不同的功能域190CT2+3、190CT3在胞内游离存在时,对急性早幼粒白血病细胞HL-60增殖分化的功能效应和相
[Abstract]:Leukemia inhibitory factor (LIF) is a multipotent cytokine, which acts on various cell tissues and plays different biological roles, and regulates cell growth, proliferation and differentiation widely. Such as inhibiting the differentiation of embryonic stem cells in vitro, stimulating platelet formation, hematopoietic cell proliferation, promoting osteoblast proliferation, promoting neurogen formation, proliferation of muscle satellite cells, and participating in neuromuscular repair. Participate in the acute stage of liver reaction, participate in the physiological and pathological process of inflammation, etc. These biological effects depend on its binding to the LIF receptor 伪 subunit (gp190) on the target cell membrane, forming heterodimer with another subunit (gp130) and activating the downstream signal transduction pathway. Gp190 (LIFR 伪 subunit) is a low affinity LIF specific receptor. It belongs to the hematopoietic receptor superfamily and lacks the activity of endogenous kinase. Soluble LIFR and transmembrane LIFR. exist in physiological state Soluble receptors, free from extracellular, transmembrane and intracellular regions, have antagonistic effects on the normal physiological effects of LIF. Transmembrane LIFR (gp190) contains three functional domains-BOX1,2,3.YXXQ sequence located at the distal end of the membrane (Y tyrosine, X arbitrary amino acid, Q glutamine), which binds specifically to the SH2 site of STAT3. Is there a intracellular free receptor in the cell? how does the intracellular receptor affect signal transduction and exert its biological effect? The effects of free peptides on cell proliferation and differentiation at the membrane receptor signal initiation site have been reported, suggesting that we, The single signal priming site of the single subunit can activate the corresponding signal transduction pathway in the cell under the condition of membrane separation. LIF signal transduction activates the JAK-STAT pathway and the RAS-MAPK pathway. We designed two kinds of small molecules, 190CT2 3 (including BOX2 3) and 190CT3 (including BOX3), according to the different functional domains of the intracellular region of gp190. We found that many functional domains of the intracellular region of gp190 become free peptides in the cell. It has different effects on cell differentiation and activates different signal molecules. In order to further verify the previous work and study the pathogenesis, two leukemia HL-60 cell lines, recombinant 190CT2 3 and 190CT3, were successfully obtained in this study, and the signal transduction pathway related to the YXXQ group site-directed mutation of 190CT3 was further studied. It was found that the proliferation of tumor cells expressing recombinant target genes (190CT2 3 and 190CT3) was inhibited, the cell maturation and differentiation were promoted, and the JAK/STAT3 pathway was activated. Through this study, we have determined the functional effect and phase of 190CT2 3190CT3 on the proliferation and differentiation of acute promyelocytic leukemia cell line HL-60 in the presence of different functional domains of gp190 in the presence of intracellular 190CT2 3190CT3.
【学位授予单位】：第二军医大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R341

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