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

基本信息

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
项目类别：
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&apos 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

项目摘要

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).

抽象的炎症小体是多蛋白信号传导支架，在细胞质的刺激下形成病原体和损伤信号激活 caspase-1。典型的炎症小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）的蛋白质，例如如 NLRP1、NLRP3 和 NLRP6。一旦炎症小体被激活，caspase-1 就会被招募到平台并通过邻近诱导的自蛋白水解作用激活。激活的 caspase-1 过程白细胞介素原 (IL)-1b、IL-18 前体和成孔蛋白gasdermin D (GSDMD)，产生这些细胞因子的成熟和释放以及焦亡细胞死亡。 NLRP6 播放在宿主防御中发挥多种作用。它在肠道和肝脏中高度表达。这据报道，NLRP6 的炎症小体功能可保护宿主免受病原体逃避和损伤引起的组织损伤。另一方面，过量的NLRP6炎症小体激活和随后过度活跃的 IL-18 信号传导可能会加剧组织损伤并引起炎症性肠病（IBD）等慢性炎症性疾病。无论有一种内在的细胞信号可以调节 NLRP6 炎症小体的活性有趣的问题。这个问题对于理解我们的身体如何维持组织至关重要通过利用这种重要的炎症小体来维持体内平衡，并为以下疾病提供靶向治疗：某些疾病。核输入是通过易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 本身据报道，通过病原体效应子介导的核启用宿主防御易位。在我们的初步研究中，我们发现 importin-b1，一种常见的核导入受体，在体外抑制 dsRNA 诱导的 NLRP6 液-液相分离，暗示核输入和 NLRP6 炎性体信号传导之间的潜在联系。在此应用中，我们将研究导入蛋白在调节 NLRP6 中的潜在作用通过解决两个问题来研究炎症小体：1) importin-NLRP6 相互作用的分子基础（冷冻电子显微镜和生物化学），2) importin-b1 在负面影响中的作用在病毒感染时调节 NLRP6 炎症小体（炎症小体细胞生物学）。