Elucidating the novel mechanism of importins in NLRP6 inflammasome regulation

阐明NLRP6炎症小体调节中输入蛋白的新机制

• 批准号: 10574850
• 负责人: Chen Shen
• 金额: $ 23.33万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-10 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10574850
• 关键词: Adaptor Signaling Protein; Affect; American; Binding; Biochemical; Biochemistry; Biological Assay; Biology; CASP1 gene; Caspase; Cell Death; Cell Nucleus; Cell physiology; Cells; Cellular biology; Chronic Disease; Co-Immunoprecipitations; Colon; Complex; Crohn' s disease; Cryoelectron Microscopy; Cytosol; Disease; Double-Stranded RNA; Drug Targeting; Event; Gastrointestinal tract structure; Homeostasis; Host Defense; Hyperactivity; IL18 gene; Image; Immune; Importins; In Vitro; Inflammasome; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Injury; Interferons; Interleukins; Intestines; Leucine-Rich Repeat; Light; Link; Liquid substance; Liver; Mass Spectrum Analysis; Mediating; Molecular; Molecular Machines; Monitor; Mus; Mutation; Nuclear Import; Nuclear Translocation; Nucleotides; Outcome; Phase; Plants; Play; Polymers; Process; Production; Protein Family; Proteins; Publishing; RNA-Binding Proteins; Regulation; Reporting; Role; Signal Induction; Signal Transduction; Signaling Protein; Structure; Syndrome; Testing; Therapeutic Intervention; Tissues; Ulcerative Colitis; VDAC1 gene; Viral; Virus; Virus Diseases; Western Blotting; autoinflammatory; chronic inflammatory disease; cytokine; dextran sulfate sodium induced colitis; experimental study; in vivo; insight; meter; mutant; novel; nucleocytoplasmic transport; pathogen; polymerization; prevent; receptor; recruit; response; scaffold; sensor; targeted treatment; tissue injury; tool; transcription factor; transport inhibitor

Abstract Inflammasomes are multi-protein signaling scaffolds that form in the cytosol upon stimulation by pathogen and damage signals to activate caspase-1. Canonical inflammasome sensors are mainly nucleotide-binding domain (NBD) and leucine-rich repeat containing (NLR) proteins, such as NLRP1, NLRP3 and NLRP6. Once inflammasome is activated, caspase-1 is recruited to the platform and activated through proximity-induced autoproteolysis. Activated caspase-1 processes pro-interleukin (IL)-1b, pro-IL-18, and the pore-forming protein gasdermin D (GSDMD), resulting in the maturation and release of these cytokines, as well as pyroptotic cell death. NLRP6 plays versatile roles in host defense. It is highly expressed in the intestine and the liver. The inflammasome function of NLRP6 has been reported to protect the host from pathogen evasion and injury-induced tissue damage. On the other hand, the excessive NLRP6 inflammasome activation and the subsequent hyperactive IL-18 signaling may exacerbate the tissue damage and cause chronic inflammatory diseases such as inflammatory bowel disease (IBD). Whether there is an intrinsic cellular signal that tunes the activity of NLRP6 inflammasome becomes an intriguing question. The question is critical to understanding how our body maintains tissue homeostasis by harnessing this important inflammasome and to provide targeted therapy for certain diseases. Nuclear import is an essential cellular process in innate immune defense by translocating activated transcription factors into the nucleus for interferon production. Plant NLRs themselves have been reported to enable host defense through pathogen effector-mediated nuclear translocation. In our preliminary study, we found that importin-b1, a common nuclear import receptor, inhibits dsRNA-induced liquid-liquid phase separation of NLRP6 in-vitro, which implicates the potential link between nuclear import and NLRP6 inflammasome signaling. In this application, we will investigate the potential role of importins in regulating the NLRP6 inflammasome by tackling two questions: 1) molecular basis of the importin-NLRP6 interaction (cryo-electron microscopy and biochemistry), and 2) the roles of importin-b1 in negatively regulating NLRP6 inflammasome upon viral infection (inflammasome cell biology).

摘要 炎性小体是一种多蛋白质信号支架，在受到 病原体和损伤信号激活caspase-1。典型的炎症体传感器是 主要是核苷酸结合域(NBD)和富含亮氨酸重复序列(NLR)蛋白，如 NLRP1、NLRP3和NLRP6。一旦炎症小体被激活，caspase-1就被招募到 平台，并通过邻近诱导的自蛋白分解激活。激活的caspase-1过程 前白介素1b、前白介素18和致孔蛋白Gasdermin D(GSDMD)，结果 在这些细胞因子的成熟和释放，以及焦链细胞的死亡。NLRP6玩法 在主场防守中扮演着多面手的角色。它在肠道和肝脏中高度表达。这个 据报道，NLRP6的炎症体功能可以保护宿主免受病原体的逃避 和损伤引起的组织损伤。另一方面，过量的NLRP6炎症体 激活和随后过度活跃的IL-18信号可能会加剧组织损伤 并导致慢性炎症性疾病，如炎症性肠病(IBD)。是否 有一种内在的细胞信号调节NLRP6的活性，炎症小体成为一种 耐人寻味的问题。这个问题对于理解我们的身体如何维持组织是至关重要的 通过利用这一重要的炎症体实现内稳态，并提供靶向治疗 某些疾病。 核输入是通过移位进行先天免疫防御的重要细胞过程 激活转录因子进入细胞核以产生干扰素。植物NLR本身 已有报道通过病原体效应器介导的核来实现宿主防御 易位。在我们的初步研究中，我们发现进口素-b1，一种常见的核进口 受体，在体外抑制dsRNA诱导的NLRP6液-液相分离，这 暗示核进口与NLRP6炎症小体信号之间的潜在联系。 在这个应用中，我们将研究重要蛋白在调节NLRP6中的潜在作用 解决两个问题的炎症组：1)Importin-NLRP6相互作用的分子基础 (冷冻电子显微镜和生物化学)，以及2)Importin-b1在负性 调节NLRP6炎症体对病毒感染的影响(炎症体细胞生物学)。