Caspase-1 Activation by the Inflammasomes

炎症小体激活 Caspase-1

• 批准号: 10616513
• 负责人: Emad S Alnemri
• 金额: $ 53.19万
• 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/10616513
• 关键词: 1-Phosphatidylinositol 4-Kinase; Acidity; Anti-Inflammatory Agents; Arthritis; Atherosclerosis; Binding; CASP1 gene; Cations; Cell Death; Cell Volumes; Chlorides; Cholesterol; Data; Development; Disease; Generations; Genetic; Gout; Health; Homeostasis; Human; IL18 gene; Infection; Inflammasome; Inflammatory; Inflammatory Response; Innate Immune Response; Interleukin-1 beta; Ions; Laboratories; Ligands; Light; Lysine; Macrophage; 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 Signaling; Regulation; Research; Role; Signal Induction; Signal Pathway; Signal Transduction; Silicon Dioxide; Site; Stimulus; Tissues; Toll-Like Receptor Pathway; Toll-like receptors; Ubiquitination; Urate; Virus Diseases; cell injury; cytokine; experimental study; in vivo; insight; 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.

炎症小体是多蛋白复合物，可聚集激活 caspase-1 以响应组织损伤 以及微生物或病毒病原体的感染。一旦激活，caspase-1 就会处理非活性的前体 白细胞介素-1β (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- 分别为 18 个。此外，caspase-1 处理 Gasdermin 蛋白 GSDMD 来诱导细胞焦亡或 炎症细胞死亡。 NLRP3 炎症小体在不同的炎症小体中是独特的，因为它 由多种病原体相关和危险相关分子模式（PAMP 和 DAMP）激活 源自微生物病原体感染或组织损伤。结果，失控的 NLRP3 激活 可导致多种人类炎症性疾病，包括痛风、关节炎、动脉粥样硬化和2型 糖尿病。人们对这些看似无关的刺激激活 NLRP3 的机制知之甚少，但 目前认为需要两个不同的信号； 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) 碎片的激活信号或“信号 2” 与 NEK7 结合。申请人实验室的研究表明信号1诱导翻译后 通过 MyD88 和 TRIF 信号通路在关键位点对 NLRP3 进行修饰 (PTM) NLRP3 的寡聚化。在此应用中，建议进行研究以阐明 TLR 诱导的 PTM 通过使用质谱分析来促进 NLRP3 炎症小体的翻译后启动 识别和表征 NLRP3 磷酸化和其他 PTM 谱中由以下因素引起的所有关键变化： 信号 1，并研究这些变化如何促进 NLRP3 的激活。额外的目标将 研究信号 1 和信号 1 诱导的 PTM 对 NLRP3 与分散的 TGN 关联的影响 NEK7，并鉴定最终组装和激活所需的 TGN 相关激酶 炎症小体。最后，初步证据表明激酶参与细胞内离子的调节 稳态通过信号 2 对 NLRP3 的激活施加负控制。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 NEK7 磷酸化和相互作用 NLRP3 的作用，以及这些激酶的遗传缺陷如何影响 NLRP3 介导的促炎症反应 体内的 PAMP 和 DAMP。这项研究的结果将为这些途径提供基本的新见解 调节 NLRP3 炎症小体的组装和激活，以及控制的细胞机制 它的激活。这项研究的成功完成应该会通过提供统一的结果对该领域产生重大影响 NLRP3 如何通过一组异常多样化的激活刺激进行调节的范例。理解 这些机制具有重大的科学和健康意义，因为这可以更好地我们了解 NLRP3 相关疾病的分子基础，从长远来看应该有助于治疗方法的开发 来缓解这些炎症性疾病。

项目成果

Chloride sensing by WNK1 regulates NLRP3 inflammasome activation and pyroptosis.

• DOI: 10.1038/s41467-021-24784-4
• 发表时间: 2021-07-27
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Mayes-Hopfinger L;Enache A;Xie J;Huang CL;Köchl R;Tybulewicz VLJ;Fernandes-Alnemri T;Alnemri ES
• 通讯作者: Alnemri ES