NLRP3 inflammasome activation and its crosstalk with RLR signaling at the mitochondria

NLRP3 炎症小体激活及其与线粒体 RLR 信号传导的串扰

基本信息

批准号：
10430234
负责人：
Naeha Subramanian
金额：
$ 45.75万
依托单位：
INSTITUTE FOR SYSTEMS BIOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-15 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10430234
关键词：
Adaptor Signaling Protein Autoimmune Diseases Bioenergetics Biological Assay CASP1 gene Cells Chemicals Communicable Diseases Complement Complex Crystallization Data Detection Fluorescence Fluorescence Microscopy Functional disorder Generations Goals IRF3 gene Infection Inflammasome Inflammation Mediators Interferon-beta Interferons Interleukin-1 beta Interleukin-18 Investigation Knock-out Link Location Mass Spectrum Analysis Mediating Membrane Metabolic Diseases Metabolic dysfunction Mitochondria Mitochondrial Proteins Modeling Mus N-terminal Nigericin Organelles Outer Mitochondrial Membrane Pathway interactions Phase Physiological Play Production Proteins RNA RNA Virus Infections RNA Viruses Receptor Signaling Resolution Role Sendai virus Signal Pathway Signal Transduction Site Solid Stimulus Structure Toxin Urate Virus Diseases X-Ray Tomography autoinflammatory crystallinity cytokine insight mouse model mutant peroxisome receptor recruit response sensor viral RNA viral detection

项目摘要

Project Summary NLRP3 (NOD-Like Receptor Protein 3) is an intracellular sensor that detects a variety of stimuli including infection and metabolic dysfunction resulting in assembly of a macromolecular signaling complex called the inflammasome which promotes caspase-1 dependent processing of the cytokines IL-1b and IL-18 to their bioactive forms; these cytokines in turn underlie the pathophysiology of many autoinflammatory, autoimmune, metabolic and infectious diseases. NLRP3 is activated by a wide-range of molecules including monosodium urate crystals, viral RNA and even bacterial pore-forming toxins, but little is known about the mechanisms by which NLRP3 senses and elicits a response to these chemically and structurally dissimilar stimuli. We and others have previously shown that NLRP3 associates with mitochondria upon activation. Whether this link simply points to a requirement for a membrane platform to achieve efficient solid-phase assembly of inflammasome signaling components or an active modulation of NLRP3 activation by mitochondrial components or even mitochondrial proteins remains ambiguous. It is also unclear if and how interaction of NLRP3 with mitochondria influences mitochondrial functions. We have previously shown that NLRP3 mitochondrial recruitment and the ensuing inflammasome response is dependent on interaction of a short N- terminal sequence in NLRP3 with the outer mitochondrial adapter protein MAVS. However, MAVS specifically augments inflammasome assembly in response to non-crystalline, but not crystalline NLRP3 activators suggesting an interesting and complex mechanism by which mitochondria regulate NLRP3 inflammasome activation. In this study, we propose that additional mitochondrial proteins control NLRP3 inflammasome activation in response to different activators, conceivably in a stimulus-specific manner. In response to detection of RNA viruses MAVS is engaged not only by NLRP3 but also by the RIG-I- like receptors (RLRs) to produce type 1 interferons, suggesting an unexpected crosstalk between the NLRP3 and RLR signaling pathways. In this proposal, we will elucidate the mechanisms by which mitochondria/MAVS regulate NLRP3 activation and examine its crosstalk with the RLR pathway. This will be accomplished by: 1) mass spectrometry to identify additional mitochondrial proteins that associate with inflammasome complexes in response to crystals and non-crystalline NLRP3 activators, followed by assays to evaluate their effect on inflammasome activation and mitochondrial functions, 2) soft X-ray tomography and correlative fluorescence microscopy to assess a requirement for subcellular membrane platforms in inflammasome assembly, and 3) models of viral infection to identify the physiological consequences of MAVS-dependent crosstalk between the NLRP3 and RLR pathways. These investigations will yield important mechanistic insights into how mitochondria and MAVS regulate NLRP3 inflammasome activation, which may be of relevance for modulation of NLRP3 activity not only in viral infections but also in a variety of metabolic diseases.

项目概要 NLRP3（NOD 样受体蛋白 3）是一种细胞内传感器，可检测多种刺激，包括感染和代谢功能障碍导致大分子信号复合物的组装，称为炎症小体促进细胞因子 IL-1b 和 IL-18 的 caspase-1 依赖性加工生物活性形式；这些细胞因子反过来是许多自身炎症、自身免疫、代谢性疾病和感染性疾病。 NLRP3 被多种分子激活，包括单钠尿酸盐晶体、病毒 RNA 甚至细菌成孔毒素，但人们对其机制知之甚少 NLRP3 能够感知这些化学和结构不同的刺激并引发反应。我们和其他人之前已经表明，NLRP3 在激活后与线粒体结合。无论是这个链接只是指出了对膜平台的要求，以实现高效的固相组装炎症小体信号传导成分或线粒体对 NLRP3 激活的主动调节成分甚至线粒体蛋白仍然不明确。还不清楚是否以及如何相互作用 NLRP3 与线粒体一起影响线粒体功能。我们之前已经证明 NLRP3 线粒体募集和随后的炎症反应取决于短 N- 的相互作用 NLRP3 中的末端序列与外部线粒体接头蛋白 MAVS。然而，MAVS 特别增强炎症小体组装以响应非晶体而非晶体 NLRP3 激活剂提示线粒体调节 NLRP3 炎症小体的有趣而复杂的机制激活。在这项研究中，我们提出额外的线粒体蛋白控制 NLRP3 炎症小体可以想象，以特定刺激的方式响应不同的激活剂而激活。作为回应 RNA 病毒的检测 MAVS 不仅受 NLRP3 的影响，还受 RIG-I 样受体 (RLR) 的影响产生 1 型干扰素，表明 NLRP3 和 RLR 信号传导之间存在意外的串扰途径。在本提案中，我们将阐明线粒体/MAVS 调节 NLRP3 的机制激活并检查其与 RLR 通路的串扰。这将通过以下方式完成：1）质量光谱法鉴定与炎性体复合物相关的其他线粒体蛋白对晶体和非晶体 NLRP3 激活剂的反应，然后进行测定来评估它们对炎症小体激活和线粒体功能，2) 软 X 射线断层扫描和相关荧光显微镜评估炎性体组装中对亚细胞膜平台的要求，以及3) 病毒感染模型，以确定 MAVS 依赖性串扰的生理后果 NLRP3 和 RLR 途径。这些研究将产生重要的机制见解线粒体和 MAVS 调节 NLRP3 炎性体激活，这可能与调节相关 NLRP3 活性不仅在病毒感染中，而且在多种代谢疾病中也存在。