GEF-H1-GBP5信号平台通过Pyrin域寡聚化调控炎性小体对腹腔感染脓毒症发生机制的研究

脓毒症临床上极具威胁，肠道固有免疫机制失调不但诱发脓毒症，也是脓毒症“受害者”，更能加重脓毒症病程。其机制尚不明确。申请人在以往研究基础上，拟采用基因敲除腹腔脓毒症小鼠，体外细胞模型，肠类器官-巨噬细胞共培养系统，特异性炎性小体激活剂刺激后，通过质谱免疫共沉淀磷酸化，蛋白寡聚化分析，相关蛋白基因表达测定，激光共聚焦观察，病理变化及其他指标检测验证以下假说：巨噬细胞在PAMPs或DAMPs模式下，鸟嘌呤核苷酸交换因子1（GEF-H1）磷酸化状态改变，结合鸟苷酸结合蛋白5（GBP5），形成新的信号募集平台，促进NLRP3炎性小体Pyrin 结构域的寡聚化，招募pro-Caspase1，促使焦亡底物蛋白GSDMD切割,完成炎性小体组装，上调炎性因子表达，引发炎症级联反应，导致肠屏障二次损伤，加重脓毒症的发展。为脓毒症防治提供新思路和治疗靶点。

Sepsis is very threatening in clinical practice. The disorder of intestinal innate immune mechanism not only causes sepsis, but also is a "victim" of sepsis, and further aggravates the course of sepsis. The mechanism is unclear. Based on the previous research, the applicant is going to use the methods such as gene knockout abdominal sepsis model mice, in vitro cell experiment, intestine organoid-macrophage co-cultured system, with specific inflammasome activator stimulation, following mass spectrometry immune coprecipitation phosphorylation, protein oligomerization analysis, determination of related protein gene expression, laser confocal observation, pathological changes and other indicators testing to verify the following hypothesis. When macrophages face the stimulation of PAMPs and DAMPs, change the phosphorylation status of GEF-H1, then GEF-H1 bind GBP5 and form a novel signaling hub which further promotes Pyrin domain oligomerization of NLRP3 inflammasome, then recruit pro-Caspase-1, promotes GSDMD, a pyroptosis-related protein, incise and complete inflammasome assembling. Finally upregulates inflammatory cytokines and triggers inflammation cascade, which results in the secondary damage of the intestinal barrier and deterioration of sepsis course. This research would apply a novel target to prevent and treat sepsis.