PLA2G7 R92H基因多态性对药源性急性严重过敏反应的作用及机制研究

Drug-induced anaphylaxis (DIA) is an unpredictable and severe allergic reaction. Histamine, leukotriene, along with platelet-activating factor acetylhydrolase (PAF), which is the most potent allergic mediator, would have impact on patients undergoing the acute phase of anaphylaxis. Our previous studies have showed that PAF could provoke DIA-like symptoms in mice. And in our latest unpublished study, it has showed that the frequency of R92H polymorphism of the gene encoding platelet-activating factor acetylhydrolase(PLA2G7) was significant lower among patients with DIA history compared to those without allergic history. This indicates that PLA2G7 R92H polymorphism might be highly correlated with DIA. However, the regulatory mechanism of PLA2G7 R92H on DIA remains unknown. This study intends to confirm the correlation between PLA2G7 R92H polymorphism and DIA in patients undergoing the acute phase of anaphylaxis and investigate the relationship between PAF-AH-related genes and the onset of DIA by next generation sequencing. Furthermore, the exact function of PLA2G7 R92H on PAF-AH will be tested in mouse AML12 cells and Kupffer cells by gene editing, and the function of PLA2G7 R92H in DIA will be tested in PLA2G7 R92H KI mice by gene knockin. The potential results of this study will reveal the regulatory mechanism of PLA2G7 R92H on DIA, and provide new experimental evidence and theoretical basis for the mechanism of DIA and DIA treatment.

药源性急性严重过敏反应（DIA）难以预测且危害严重，DIA患者受组胺、白三烯及更强的过敏介质血小板活化因子（PAF）的影响。我们的研究表明：PAF可激发小鼠典型DIA样表现；既往DIA患者PAF乙酰水解酶（PAF-AH）编码基因的PLA2G7 R92H突变频率显著低于无过敏史者，提示该基因多态性与DIA密切相关，但机制尚不明确。本项目通过二代基因捕获测序技术检测DIA急性期患者PAF信号通路（含PAF-AH）基因多态性，验证PLA2G7 R92H与急性期DIA的相关性，寻找影响DIA的其他可能位点；通过基因编辑技术，在鼠肝实质细胞、肝巨噬细胞中研究PLA2G7 R92H对PAF-AH酶活性的影响；在基因敲入技术制备的PLA2G7 R92H KI小鼠模型中，验证PLA2G7 R92H的功能。研究将揭示PLA2G7 R92H在DIA发生中的作用，为认识和防治DIA的发生提供新的研究证据。

药源性严重过敏反应(DIA)是危及生命的严重的药物不良反应，血小板活化因子(PAF)是DIA是主要介质之一，本项目提出PAF乙酰水解酶（PAF-AH）基因多态性可能会影响DIA的发生。因此我们设计了过敏介质相关的二代基因捕获测序芯片并应用于检测DIA患者PAF信号通路基因多态性。通过基因编辑技术在小鼠肝实质细胞验证了PLA2G7 R92H对PAF-AH酶活性的影响；通过基因敲入技术，分别在野生型和PLA2G7 R92H基因型小鼠中验证了PLA2G7 R92H的功能。. 研究结果显示PLA2G7 rs1805017、CEPT1 rs3795823、HDC rs17740607以及HNMT rs1050891 可能与DIA发生相关；PLA2G7 rs1805017-T与对应编码蛋白(PAF-AH)酶活性增加有关；同时证实PLA2G7 R92H基因多态性在细胞及动物模型中与PAF-AH含量、活性及过敏反应相关。. 本项目揭示了PLA2G7 R92H基因多态性对于严重过敏反应的调控作用及机制，并基于研究发现牵头制定了《严重过敏反应急救指南》，为认识和防治DIA的发生提供新的研究证据。