RIP2 caspase-1 signaling in macrophages

巨噬细胞中的 RIP2 caspase-1 信号传导

• 批准号: 7755854
• 负责人: Mark Damian Wewers
• 金额: $ 37.5万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-12 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7755854
• 关键词: AG 126; Affect; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Apoptosis; Biology; CASP1 gene; Caspase; Caspase-1; Cell Death; Cells; Cessation of life; Complex; Cytosol; Data; Disease; Down-Regulation; Enzyme Activation; Event; Homologous Gene; Host Defense; Immune response; Individual; Infection; Infectious Agent; Inflammation; Inflammatory; Inflammatory Response; Injury; Interleukin-12; Interleukin-18; Laboratories; Lead; Leucine; Link; Lung; Mediating; Membrane; Molecular; Outcome; Pathogenesis; Phosphorylation; Phosphotransferases; Plants; Play; Process; Protein Tyrosine Kinase; Proteins; RIPK2 gene; Regulation; Role; Sepsis; Septic Shock; Severities; Signal Transduction; System; Tyrphostins; United States; caspase-5; cytokine; improved; knockout animal; macrophage; marenostrin; mortality; novel therapeutic intervention; pathogen; protein complex; public health relevance; response; septic; trafficking

DESCRIPTION (provided by applicant): Macrophage release of 17 kDa IL-12 is a highly regulated event that extends beyond the macrophage's ability to transcribe and synthesize the precursor, 31 kDa proIL-12. This event is centered upon activation of the enzyme caspase-1 and involves a complex protein assemblage termed the inflammasome. Inflammasome components are homologues of an ancient innate host defense system that exists in both plants and animals. The present proposal seeks to expand upon the clues derived from the macrophage biology of IL-12 and extend these processes to the basics of the host response to sepsis. We have recent data to demonstrate that key components of this intracellular inflammasome complex contribute significantly to the devastating activation of the innate host response that defines septic shock. More specifically, caspase-1, the central target of the inflammasome has been directly linked to sepsis. Not only are caspase-1 knockout animals protected from sepsis mortality but individual components of the caspase-1 inflammasome complex (e.g., caspase-5, ASC and NALP1) have also been linked to sepsis outcomes. These proteins interact with each other via caspase recruitment domains (CARDs) and structurally related pyrin domains (PYDs). Our hypothesis is that posttranslational events centered upon these CARD and PYD domains are central to the pathogenesis of sepsis. Inflammasome assembly not only regulates the processing and activation of inflammatory cytokines like IL-12 and IL-18 but extends to the regulation of NF-?B and host cell apoptosis. The current proposal seeks to apply these exciting breakthroughs in the biology of macrophage function to the challenge of sepsis. We know that one of the key regulatory events in inflammasome assembly is the triggering of CARD/CARD and PYD/PYD interactions. We have recently demonstrated that regulating CARD-containing molecules (e.g., RIP2 and ASC) can direct the caspase-1 centered inflammatory response either toward NF-?B or toward IL-12 processing. Interestingly, these events involve an early phosphorylation event since inhibition of tyrosine kinase activity profoundly affects the inflammasome and also protects animals from sepsis. Thus, this proposal seeks to dissect the molecular details of how these events are regulated. The central hypothesis is that the master regulatory switch that determines the direction and severity of the pro and anti-inflammatory responses to septic challenge are controlled in the cytosol by specific CARD/CARD and PYD/PYD interactions. We will dissect the mechanisms that regulate the ability of caspase-1 and RIP2 to interact, traffic to membranes and then direct host inflammation. These events initially induce NF-?B activation but subsequently, via caspase-1 catalytic activation, may finally induce apoptosis and down regulation of NF-?B events. These studies will improve our understanding of the basic innate host responses to sepsis and in doing so uncover novel therapeutic approaches to septic shock and other inflammatory disorders that are regulated by this caspase-1-centric process. PUBLIC HEALTH RELEVANCE: Septic shock, the whole body injury that can occur as a result of overwhelming infections, is common and represents the cause of over 200,000 deaths annually in the United States. In this context, the body's response to infectious agents involves newly described sensing proteins that we believe are critical to the defense against the injuries. This proposal seeks to understand how these defense proteins react with infectious agents to regulate cell death and inflammatory responses, particularly in the context of sepsis.

描述（由申请人提供）：17 kDa IL-12的巨噬细胞释放是一个高度调节的事件，超出了巨噬细胞转录和合成前体的能力，即31 kDa proil-12。该事件以激活酶caspase-1的激活为中心，并涉及称为炎症体的复杂蛋白质组合。炎症组成部分是植物和动物中存在的古代先天宿主防御系统的同源物。本提案旨在扩大IL-12的巨噬细胞生物学的线索，并将这些过程扩展到宿主对败血症的基础知识。我们最近有数据证明，这种细胞内炎症体复合物的关键成分对定义败血性休克的先天宿主反应的毁灭性激活产生了显着贡献。更具体地说，caspase-1是炎症体的核心目标与败血症直接相关。 caspase-1基因敲除动物不仅可以保护败血症死亡率，而且还与caspase-1炎性体复合物（例如caspase-5，ASC和NALP1）的个体成分也与败血症结果有关。这些蛋白质通过caspase募集域（卡）和结构相关的吡啶域（PYDS）相互相互作用。我们的假设是，以这些卡和PYD结构域为中心的翻译后事件对于败血症的发病机理至关重要。炎性体组装不仅调节IL-12和IL-18等炎性细胞因子的加工和激活，而且还扩展到NF- b和宿主细胞凋亡的调节。当前的提案旨在将这些令人兴奋的突破应用于巨噬细胞功能的生物学，以挑战败血症。我们知道，炎性组组装中的关键调节事件之一是触发卡/卡和PYD/PYD相互作用。我们最近证明，调节含卡的分子（例如RIP2和ASC）可以将CASPASE-1中心炎症反应引导到NF-？b或朝向IL-12处理。有趣的是，这些事件涉及早期的磷酸化事件，因为抑制酪氨酸激酶活性会深刻影响炎症体，并保护动物免受败血症的侵害。因此，该提议旨在剖析这些事件如何调节的分子细节。中心假设是确定Pro的方向和严重程度和抗炎反应对化粪池挑战的方向和严重程度的主调节开关受到特定卡/卡和PYD/PYD相互作用的控制。我们将剖析调节caspase-1和RIP2相互作用的能力，流量到膜，然后直接宿主炎症的机制。这些事件最初会诱导NF-？B激活，但随后通过caspase-1催化激活，最终可能诱导凋亡并下调NF- b事件。这些研究将提高我们对败血症的基本先天宿主反应的理解，并在这样的过程中揭示了因这种以caspase-1的过程调节的败血性休克和其他炎症性疾病的新型治疗方法。公共卫生相关性：败血性冲击是由于压倒性感染而导致的全身伤害，是普遍的，代表了美国每年超过200,000人死亡的原因。在这种情况下，人体对传染剂的反应涉及新描述的感应蛋白，我们认为这对于防御伤害至关重要。该提案试图了解这些防御蛋白如何与传染剂反应以调节细胞死亡和炎症反应，特别是在败血症的背景下。