自噬在TLR4介导蓖麻毒素炎性损伤中的作用机制研究

The mechanism of ricin toxicity is inhibition of protein synthesis and inflammatory damage. Ricin, as a biological toxin which is extremely fatal to almost all animals, has been listed as potentially important ricin warfare agent. Studying the mechanism of ricin-mediated inflammatory response is important to understand the mechanism of toxicity. Autophagy and pattern recognition receptors are different ways of cells response to pathogens and various foreign matter intrusions, which play an important role in the immune response. Cross-talk between autophagy and pattern recognition receptors, is current focus of international research. Preliminary experiments show that intestinal and immune cell inflammation damage can be induced in mice by administration of ricin via a p38MAPK-sensitive pathway. Ricin of low concentration can promote mouse peritoneal macrophages to secrete NO and upregulate the expression of Toll like receptor 4(TLR4). On the foundation of the integral experiment and cellular experiment, this study is planned to explore the function of TLR4 and the interaction between autophagy and TLR4 during the process of ricin inflammatory injury. Moreover, employing comparative proteomics and other technologies，this study seeks and confirms related protein involved in autophagy and TLR4 signalling pathway in ricin-mediated inflammatory and injury process in order to explain the damage mechanism induced by ricin and provide theoretical foundation for ricin protection and detoxification.

蓖麻毒素毒性作用主要为抑制蛋白质合成和诱导炎性损伤,几乎对所有动物细胞都有毒性,是一种致命、毒性极强的生物毒素,被列为潜在重要生物战剂和恐怖剂。开展蓖麻毒素致炎机制研究,对阐明其毒性机理具有重要意义。自噬和模式识别受体是细胞应对病原体及各种外来物质入侵的不同途径,在诱导机体天然免疫应答反应中具有重要作用,它们间的相互作用机制目前是国际研究热点。前期实验表明蓖麻毒素诱导小鼠肠道及免疫细胞产生炎性损伤,可能通过激活p38/MAPKs通路来实现;低浓度蓖麻毒素可促进小鼠巨噬细胞NO分泌、Toll样受体4(TLR4)表达上调。本研究拟从整体实验及细胞实验水平,探讨蓖麻毒素炎性损伤过程中TLR4的作用、自噬发生与TLR4的相互作用,并利用比较蛋白质组学等技术手段,寻找、验证蓖麻毒素炎性损伤过程中与自噬和TLR4信号通路相关的蛋白,从而进一步阐明蓖麻毒素诱导炎性损伤机制,为蓖麻毒素防护、解毒奠定基础。

蓖麻毒素毒性作用主要为抑制蛋白质合成和诱导炎性损伤,几乎对所有动物细胞都有毒性,是一种致命、毒性极强的生物毒素,被列为潜在重要生物战剂和恐怖剂。开展蓖麻毒素致炎机制研究,对阐明其毒性机理具有重要意义。本课题研究发现自噬和模式识别受体是细胞应对RT入侵的不同途径，RT损伤后巨噬细胞可以通过其表面TLR4受体，触发天然免疫，RT损伤巨噬细胞后可以诱导自噬发生，RT诱导发生自噬可能与p38/MAPK信号通路有关，与JNK信号通路无关。自噬在RT诱导机体天然免疫应答中起负调控作用，可以避免TLR4信号过度活化，维持机体免疫稳态。利用高通量测序技术、比较蛋白质组学和生物信息学技术，筛选到与RT炎性损伤相关的蛋白187个，其中20个蛋白表达上调，167个蛋白表达下调，从转录组和蛋白质组层面阐明RT诱导炎性损伤机制，为蓖麻毒素防护、解毒奠定基础。