【作者】 夏小春；

【导师】 俞春东；

【作者基本信息】 厦门大学 ， 细胞生物学， 2013， 博士

【摘要】 肥大细胞是在IgE介导的过敏反应中起到关键作用的效应细胞,当过敏原引发其表面高亲和受体FcsRI聚集交联后即可触发信号通路的激活从而引起细胞的脱颗粒和炎症因子的产生。因此,研究抑制IgE和FcεRI言号通路成为研究新的抗过敏药物的重要手段。环氧二烯(Mcoyepoxydiene, MED)是海洋木栖真菌菜豆间坐壳菌(Diaporthe sp. HLY-1)的次级代谢产物,是一个以含有氧桥的八元环二烯为骨架的化合物。已有的研究显示MED有抗肿瘤活性,抑制炎症反应等功能,而过敏反应的发生和炎症的产生有密切的关系,但MED在过敏反应发生的过程中的作用尚无研究。在本课题研究中发现MED可明显抑制抗原引起的肥大细胞脱颗粒和炎症因子的产生,分子机制研究发现,MED通过抑制抗原刺激引起的酪氨酸激酶(Spleen tyrosine kinase, Syk)的磷酸化后进一步抑制其下游基因磷酸酯酶C(phospholipase C. PLCyl),丝氨酸/苏氨酸激酶Akt的磷酸化,且MED对在炎症因子表达中起重要作用的丝裂原活化蛋白激酶(Mitogen activated protein kinase. MAPKs,包括ERK, JNK, p38)磷酸化也有明显的抑制作用。小鼠被动型皮肤过敏反应(Passive cutaneous anaphylaxis. PCA)模型研究结果表明,MED可明显抑制小鼠耳朵血管渗透的发生,发挥了明显的抑制过敏反应发生的作用。综上所述,MED通过抑制Syk的磷酸化进而抑制PI3K/Akt和MAPKs的信号通路,抑制肥大细胞的活性从而抑制小鼠过敏反应的发生。本研究为进一步将MED开发为治疗过敏药物提供了一定的理论依据。同时,我们利用了类固醇激素受体辅激活子3(Steriod receptor coactivator. SRC-3)野生型和敲除型小鼠进行过敏的实验研究。通过体外肥大细胞诱导系统和(Passive systemic anaphylaxis, PSA)动物模型的研究,我们发现来源SRC-3敲除小鼠的细胞在抗原抗体刺激下炎症因子的产生量明显高于来源于野生型小鼠的细胞,动物模型结果显示,SRC-3敲除小鼠表现出比野生型小鼠更为强烈的过敏反应,提示SRC-3在小鼠过敏反应发生中起到了一个保护作用。更多还原

【Abstract】 Mast cells play a critical role in IgE-mediated allergic response. Aggregation of the high affinity IgE receptor (FcεRl) which is on the surface of mast cell activates a cascade of signaling events leading to the degranulation and cytokines production. Therefore, inhibition of IgE and FcεRI signaling pathway provides a new method for development of novel anti-anaphylaxis drugs.Mycoepoxydiene (MED) is a compound which was extracted from Diaporthe phaseolorum as a secondary metabolic product. Previous study has revealed that MED has many kinds of biologic activity including anti-cancer and inhibiting inflammation. However. the function of MED in allergic reaction is still unknown.It is well known that allergic response displays cytokines production and degranulation features. In our study, we found that MED could significantly suppress antigen-stimulated degranulation and cytokines production in bone marrow derived mast cells (BMMCs). The study showed that MED could significantly inhibit the phosphorylation of Syk and in turn to inhibit the phosphorylation of its downstream molecules PLCy and Akt. Beside. MED suppressed the phosphorylation of MAPKs including extracellular signal-regulated kinase (ERK). c-jun N-terminal kinase (JNK). and p38in antigen stimulated mast cells.Based on the results of cell experiments, we studied MED in PCA mouse model, and MED effectively alleviated the ear blood vessel permeation caused by antigen. These results suggested that MED is a potential compound for developing a promising anti-anaphylaxis drug.At the same time. we studied the role of SRC-3in allergic response. Our results displayed that the BMMCs from SRC-3knockout mice produced more cytokines than the cells from wide type mice. PSA mouse model also showed that the SRC-3knockout mice suffered a more severe allergic response. These results demonstrated that SRC-3play a protect role in the anaphylaxis in mice.更多还原