Caspase-1 Activation by the Inflammasomes

炎症小体激活 Caspase-1

• 批准号: 10401755
• 负责人: Emad S Alnemri
• 金额: $ 52.66万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10401755
• 关键词: 1-Phosphatidylinositol 4-Kinase; Acidity; Anti-Inflammatory Agents; Arthritis; Atherosclerosis; Binding; CASP1 gene; Cations; Cell Death; Cell Volumes; Chlorides; Cholesterol; Crystallization; Data; Development; Disease; Generations; Genetic; Gout; Health; Homeostasis; Human; Infection; Inflammasome; Inflammatory; Inflammatory Response; Innate Immune Response; Interleukin-1 beta; Interleukin-18; Ions; Laboratories; Lead; Ligands; Light; Lysine; Mass Spectrum Analysis; Mediating; Mitosis; Molecular; Molecular Conformation; Multiprotein Complexes; NIMA; Natural Immunity; Non-Insulin-Dependent Diabetes Mellitus; Nucleotides; Pathway interactions; Pattern; Phase; Phosphorylation; Phosphotransferases; Physiological; Post-Translational Protein Processing; Process; Production; Protein Dephosphorylation; Proteins; Receptor Activation; Receptor Signaling; Regulation; Research; Role; Signal Pathway; Signal Transduction; Silicon Dioxide; Site; Stimulus; Tissues; Toll-Like Receptor Pathway; Toll-like receptors; Ubiquitination; Urate; Virus Diseases; cell injury; crystallinity; cytokine; experimental study; in vivo; insight; macrophage; marenostrin; microbial; novel; novel therapeutics; pathogen; pathogenic microbe; pathogenic virus; phosphatidylinositol 4-phosphate; protein kinase D; recruit; response; stress granule; symporter; therapeutic development; trans-Golgi Network

Inflammasomes are multi-protein complexes that assemble to activate caspase-1 in response to tissue damage and infection by microbial or viral pathogens. Once activated, caspase-1 processes the inactive proforms of interleukin-1β (IL-1β) and interleukin-18 (IL-18) to produce the active pro-inflammatory cytokines IL-1β and IL- 18, respectively. In addition, caspase-1 processes the gasdermin protein GSDMD to induce pyroptosis or inflammatory cell death. The NLRP3 inflammasome is unique among the different inflammasomes in that it is activated by diverse pathogen-associated and danger-associated molecular patterns (PAMPs and DAMPs) derived from infection with microbial pathogens, or tissue damage. As a result, uncontrolled NLRP3 activation can lead to a number of human inflammatory diseases, including gout, arthritis, atherosclerosis, and type 2 diabetes. The mechanism of NLRP3 activation by these seemingly unrelated stimuli is poorly understood but is currently believed to require two distinct signals; a priming signal or “signal 1” produced by Toll-like receptors (TLRs) and an activation signal or “signal 2” that induces fragmentation of trans Golgi network (TGN) and binding to NEK7. Studies in the applicant's laboratory demonstrated that signal 1 induces post-translational modification (PTM) of NLRP3 at critical sites via the MyD88 and TRIF signaling pathways and partial oligomerization of NLRP3. In this application, studies are proposed to elucidate how TLR-induced PTM contributes to posttranslational priming of the NLRP3 inflammasome by employing mass spectrometry to identify and characterize all critical changes in the phosphorylation and other PTM profile of NLRP3 induced by signal 1, and investigating how these changes contribute to activation of NLRP3. Additional aims will investigate the effect of signal 1 and signal 1-induced PTM on NLRP3 association with dispersed TGN and NEK7, and identify the TGN-associated kinases required for final assembly and activation of the inflammasome. Finally, preliminary evidence suggest that kinases involved in the regulation of intracellular ion homeostasis exert negative control on activation of NLRP3 by signal 2. Thus, additional experiments will investigate how signaling from these kinases in macrophages impacts NEK7 phosphorylation and interaction with NLRP3, and how genetic deficiency in these kinases impacts NLRP3-mediated pro-inflammatory responses to PAMPs and DAMPs in vivo. Results from this research will provide fundamental new insights into the pathways that regulate the assembly and activation of the NLRP3 inflammasome, and the cellular mechanisms that control its activation. Successful completion of this study should have a high impact on the field by providing a unifying paradigm for how NLRP3 can be regulated by an exceptionally diverse group of activating stimuli. Understanding these mechanisms is of great scientific and health significance as this should better our understanding of the molecular basis of NLRP3-related diseases and should in the long term help in the development of therapeutics to alleviate these inflammatory diseases.

炎性小体是多蛋白复合物，其组装以响应组织损伤而激活caspase-1 以及微生物或病毒病原体的感染。一旦被激活，caspase-1处理非活性的前体， 白细胞介素-1 β（IL-1β）和白细胞介素-18（IL-18）产生活性促炎细胞因子IL-1β和IL-18。 18、分别此外，caspase-1加工gasdermin蛋白GSDMD以诱导细胞凋亡或 炎性细胞死亡NLRP 3炎性小体在不同炎性小体中是独特的，因为它是 由多种病原体相关和病原体相关分子模式（PAMP和DAMP）激活 来源于微生物病原体感染或组织损伤。结果，不受控制的NLRP 3激活 可导致许多人类炎症性疾病，包括痛风、关节炎、动脉粥样硬化和2型糖尿病。 糖尿病NLRP 3被这些看似无关的刺激激活的机制知之甚少， 目前认为需要两种不同的信号：由Toll样受体产生的启动信号或“信号1” （TLR）和诱导反式高尔基体网络（TGN）片段化的激活信号或“信号2”，以及 与NEK 7结合。申请人实验室的研究表明，信号1诱导翻译后表达。 通过MyD 88和TRIF信号传导途径在关键位点修饰NLRP 3（PTM）， NLRP 3的寡聚化。在本申请中，提出了研究来阐明TLR诱导的PTM是如何发生的。 有助于NLRP 3炎性体的翻译后引发， 鉴定和表征由以下物质诱导的NLRP 3磷酸化和其他PTM谱的所有关键变化： 信号1，并研究这些变化如何有助于NLRP 3的激活。其他目标将 研究信号1和信号1诱导的PTM对NLRP 3与分散的TGN的关联的影响， NEK 7，并确定TGN相关激酶的最终组装和激活所需的 炎性小体最后，初步证据表明，激酶参与调节细胞内离子 稳态通过信号2对NLRP 3激活施加负控制。因此，额外的实验将 研究巨噬细胞中这些激酶的信号传导如何影响NEK 7磷酸化和相互作用 以及这些激酶的遗传缺陷如何影响NLRP 3介导的促炎反应 PAMPs和DAMPs在体内。这项研究的结果将为这些途径提供基本的新见解， 调节NLRP 3炎性体的组装和激活，以及控制NLRP 3炎性体的细胞机制。 其激活。本研究的成功完成将通过提供统一的 NLRP 3是如何被一组异常多样的激活刺激调节的。理解 这些机制具有重要的科学和健康意义，因为这将使我们更好地了解 NLRP 3相关疾病的分子基础，并应在长期帮助治疗的发展 来缓解这些炎症性疾病。