Mechanisms of activation of the NLRP3 Inflammasome by extracellular calcium ions

细胞外钙离子激活NLRP3炎症小体的机制

• 批准号: 264002799
• 负责人: Professor Dr. Norbert Sträter
• 金额: --
• 依托单位: Bereich Rheumatologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/264002799?language=en
• 关键词: Mechanisms; activation; NLRP3; Inflammasome; extracellular

Extracellular Ca2+ ions were identified by the group of the lead applicant as potent stimuli of pro-inflammatory cellular effector mechanisms in monocytes, which act through triggering of the G protein coupled receptors CaSR and GPRC6A. For both receptors, the precise ligand binding sites and signal transduction pathways into the cell are not known.Unpublished data of the applicants show that for the exCa2+-induced stimulation, the presence of phosphate ions is an absolut requirement. Under such pro-inflammatory condition of increased Ca2+ and phosphate concentrations, however, calcium phosphate pre-nucleation cluster and calcium phosphate crystals can develop. The aim of the project is to investigate the mechanisms behind the pro-inflammatory Ca2+ and phosphate sensing, as well as the role of ion clusters and calcium phosphate crystals in this process.The required experiments will be performed using a floxed CaSR knockout and a GPRC6A deficient mouse model as well as genetic knockdown experiments of the phosphate sensitive, sodium dependent Pi-Co-transporter PiT-1. The ectodomains and full length protein of the two GPCRs will be expressed in vitro for functional studies of ligand binding and receptor activation as well for structural analysis of both receptors.

细胞外Ca 2+离子被主要申请人的小组鉴定为单核细胞中促炎细胞效应器机制的有效刺激物，其通过触发G蛋白偶联受体CaSR和GPRC 6A起作用。申请人未公开的数据表明，对于exCa 2+诱导的刺激，磷酸根离子的存在是绝对需要的。然而，在Ca 2+和磷酸盐浓度增加的这种促炎条件下，可以形成磷酸钙预成核簇和磷酸钙晶体。该项目的目的是研究促炎性Ca 2+和磷酸盐感知背后的机制，以及离子簇和磷酸钙晶体在这一过程中的作用。所需的实验将使用floxed CaSR敲除和GPRC 6A缺陷小鼠模型以及磷酸盐敏感的钠依赖性Pi-Co-转运蛋白PiT-1的基因敲除实验进行。两种GPCR的胞外域和全长蛋白将在体外表达，用于配体结合和受体活化的功能研究以及两种受体的结构分析。