Raf激酶抑制蛋白RKIP负向调控FcεR1信号活化和肥大细胞介导的过敏性反应
发布时间：2018-07-16 11:17
【摘要】：肥大细胞是一类由骨髓来源的造血干细胞分化而来的免疫细胞,主要分布在与外界环境接触紧密的皮肤、气道和肠道等组织的黏膜,是引发机体I型超敏反应和过敏性反应的极为关键的效应细胞。就目前研究认为,肥大细胞是过敏反应的初级效应细胞,在过敏反应中居于十分关键的位置[1,2]。活化的肥大细胞通过释放颗粒中预先合成的化学介质,并产生多种细胞因子和趋化因子,以及分泌新合成的花生四烯酸和各种蛋白质从而导致信号级联放大,促发过敏反应[3]Raf激酶抑制蛋白RKIP是磷脂酰乙醇胺结合蛋白家族成员之一,能够抑制MEK的磷酸化而影响下游信号通路的活化,参与调控肿瘤细胞的转移及心肌细胞的功能。也有研究表明RKIP还可以通过影响NF-κB的活化而在天然免疫反应中发挥一定的作用。我们最近研究发现RKIP正向调控抗病毒免疫反应和促进炎症性肠炎的发病。RKIP广泛表达于各类哺乳动物的脑、肝脏、胃、脾脏及肌肉等组织中,在小鼠肥大细胞中也有较高表达。目前,尚未报道RKIP在肥大细胞及过敏性疾病中作用,我们从数据库中检索发现RKIP的表达量在肥大细胞被动致敏和受到抗原刺激后发生显著性变化,同时检测哮喘患者外周血中RKIP基因水平的表达变化,我们发现RKIP的mRNA表达明显低于正常人的外周血中RKIP的表达水平。同时,我们在体外培养的小鼠原代肥大细胞中发现,IgE/BSA致敏并刺激小鼠原代肥大细胞后,RKIP表达下降。分离培养野生型WT和RKIP敲除KO原代肥大细胞,进行体外研究,结果显示,RKIP敲除后,显著增加DNP-IgE/DNP-BSA(FcεRI活化)诱导的炎症性细胞因子和趋化因子产生,同时增强肥大细胞脱颗粒过程。进一步研究发现,而RKIP在小鼠中敲除后,能明显地促进FCεRI活化的肥大细胞介导的全身性以及局部过敏反应。信号通路实验发现RKIP靶向PI3K调节亚基p85cα从而负向调控FcεRI介导的肥大细胞的PI3K/AKT/NF-κB信号通路。进一步机制研究发现,RKIP是通过与Gab2竞争性结合PI3K调节亚基p85a而抑制PI3K活化。综上所述,本研究结果揭示了RKIP负向调控肥大细胞的介导的过敏反应重要作用机制,丰富了RKIP的生理功能,并为机体免疫防御及过敏性疫病疾病的治疗提供新的思路。
[Abstract]:Mast cells are a class of immune cells derived from hematopoietic stem cells derived from bone marrow, mainly distributed in the mucous membranes of skin, airways and intestines that are in close contact with the outside environment. It is a key effector cell for type I hypersensitivity and hypersensitivity. It is believed that mast cells are primary effector cells of allergic reaction and play a key role in anaphylaxis [1]. Activated mast cells produce a variety of cytokines and chemokines, as well as newly synthesized arachidonic acid and proteins, resulting in signal cascade amplification by releasing pre-synthesized chemical mediators in the particles. RKIP is a member of phosphatidylethanolamine binding protein family, which can inhibit the phosphorylation of MEK and affect the activation of downstream signal pathway. RKIP is involved in regulating the metastasis of tumor cells and the function of cardiomyocytes. Some studies have also shown that RKIP can also play a role in innate immune response by affecting the activation of NF- 魏 B. We recently found that RKIP positively regulates the antiviral immune response and promotes the pathogenesis of inflammatory enteritis. RKIP is widely expressed in the brain, liver, stomach, spleen and muscle of various mammals, as well as in mouse mast cells. At present, we have not reported the role of RKIP in mast cells and allergic diseases. We found that the expression of RKIP changed significantly after the mast cells were sensitized passively and stimulated by antigen. At the same time, we detected the expression of RKIP gene in the peripheral blood of asthmatic patients. We found that the mRNA expression of RKIP was significantly lower than that of the normal controls. At the same time, we found that IgE / BSA sensitized primary mast cells in vitro and stimulated the expression of RKIP in primary mast cells of mice. Wild type WT and RKIP knockout KO primary mast cells were isolated and cultured in vitro. The results showed that RKIP knockout significantly increased the production of inflammatory cytokines and chemokines induced by DNP-IgE / DNP-BSA (FC 蔚 RI activation) and enhanced the degranulation process of mast cells. Further studies showed that RKIP could significantly promote FC 蔚 RI activated mast cell mediated systemic and local hypersensitivity after knockout in mice. RKIP targeted PI3K regulatory subunit p85c 伪 and negatively regulated the PI3K / AKT / NF- 魏 B signaling pathway of mast cells mediated by FC 蔚 RI. Further studies revealed that RKIP inhibited the activation of PI3K by competing with Gab2 PI3K regulatory subunit p85a. In conclusion, this study revealed the important mechanism of RKIP negative regulation of mast cell mediated allergic reaction, enriched the physiological function of RKIP, and provided a new idea for immune defense and the treatment of allergic blight disease.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R392
，
本文编号：2126218
[Abstract]:Mast cells are a class of immune cells derived from hematopoietic stem cells derived from bone marrow, mainly distributed in the mucous membranes of skin, airways and intestines that are in close contact with the outside environment. It is a key effector cell for type I hypersensitivity and hypersensitivity. It is believed that mast cells are primary effector cells of allergic reaction and play a key role in anaphylaxis [1]. Activated mast cells produce a variety of cytokines and chemokines, as well as newly synthesized arachidonic acid and proteins, resulting in signal cascade amplification by releasing pre-synthesized chemical mediators in the particles. RKIP is a member of phosphatidylethanolamine binding protein family, which can inhibit the phosphorylation of MEK and affect the activation of downstream signal pathway. RKIP is involved in regulating the metastasis of tumor cells and the function of cardiomyocytes. Some studies have also shown that RKIP can also play a role in innate immune response by affecting the activation of NF- 魏 B. We recently found that RKIP positively regulates the antiviral immune response and promotes the pathogenesis of inflammatory enteritis. RKIP is widely expressed in the brain, liver, stomach, spleen and muscle of various mammals, as well as in mouse mast cells. At present, we have not reported the role of RKIP in mast cells and allergic diseases. We found that the expression of RKIP changed significantly after the mast cells were sensitized passively and stimulated by antigen. At the same time, we detected the expression of RKIP gene in the peripheral blood of asthmatic patients. We found that the mRNA expression of RKIP was significantly lower than that of the normal controls. At the same time, we found that IgE / BSA sensitized primary mast cells in vitro and stimulated the expression of RKIP in primary mast cells of mice. Wild type WT and RKIP knockout KO primary mast cells were isolated and cultured in vitro. The results showed that RKIP knockout significantly increased the production of inflammatory cytokines and chemokines induced by DNP-IgE / DNP-BSA (FC 蔚 RI activation) and enhanced the degranulation process of mast cells. Further studies showed that RKIP could significantly promote FC 蔚 RI activated mast cell mediated systemic and local hypersensitivity after knockout in mice. RKIP targeted PI3K regulatory subunit p85c 伪 and negatively regulated the PI3K / AKT / NF- 魏 B signaling pathway of mast cells mediated by FC 蔚 RI. Further studies revealed that RKIP inhibited the activation of PI3K by competing with Gab2 PI3K regulatory subunit p85a. In conclusion, this study revealed the important mechanism of RKIP negative regulation of mast cell mediated allergic reaction, enriched the physiological function of RKIP, and provided a new idea for immune defense and the treatment of allergic blight disease.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R392
，
本文编号：2126218
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