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）：巨噬细胞释放17 kDa IL-12是一种高度调节的事件，其超出了巨噬细胞转录和合成前体31 kDa proIL-12的能力。该事件的中心是半胱天冬酶-1的激活，并涉及称为炎性体的复杂蛋白质聚集体。炎性体组分是存在于植物和动物中的古老先天宿主防御系统的同源物。目前的建议旨在扩大从IL-12的巨噬细胞生物学的线索，并将这些过程扩展到脓毒症的宿主反应的基础。我们最近的数据表明，这种细胞内炎性体复合物的关键成分显着有助于破坏性激活先天宿主反应，定义感染性休克。更具体地说，半胱天冬酶-1，炎性小体的中心靶点，已经直接与脓毒症相关。不仅胱天蛋白酶-1敲除动物免于败血症死亡，而且胱天蛋白酶-1炎性体复合物的单个组分（例如，半胱天冬酶-5，ASC和NALP 1）也与脓毒症结果相关。这些蛋白质通过半胱天冬酶募集结构域（CARD）和结构相关的pyrin结构域（PYD）相互作用。我们的假设是，这些CARD和PYD结构域的翻译后事件是中央脓毒症的发病机制。炎性小体组装不仅调节IL-12和IL-18等炎性细胞因子的加工和活化，而且还延伸到NF-？B和宿主细胞凋亡。目前的提案旨在将这些令人兴奋的巨噬细胞功能生物学突破应用于脓毒症的挑战。我们知道炎性小体组装中的关键调节事件之一是CARD/CARD和PYD/PYD相互作用的触发。我们最近已经证明，调节含CARD的分子（例如，RIP 2和ASC）可以将以caspase-1为中心的炎症反应导向NF-？B或朝向IL-12加工。有趣的是，这些事件涉及早期磷酸化事件，因为酪氨酸激酶活性的抑制深刻地影响炎性小体，也保护动物免于败血症。因此，这项建议试图剖析这些事件是如何调节的分子细节。中心假设是，决定脓毒症激发的促炎和抗炎反应的方向和严重程度的主调节开关在胞质溶胶中由特异性CARD/CARD和PYD/PYD相互作用控制。我们将剖析调节caspase-1和RIP 2相互作用，运输到膜，然后直接宿主炎症的能力的机制。这些事件最初诱导NF-？B激活，但随后，通过caspase-1催化激活，可能最终诱导凋亡和下调NF-？B类事件。这些研究将提高我们对脓毒症的基本先天宿主反应的理解，并在此过程中发现脓毒性休克和其他炎症性疾病的新治疗方法，这些疾病受caspase-1中心过程的调节。公共卫生关系：感染性休克是一种全身性损伤，可能是由于大量感染而发生的，在美国很常见，每年造成20多万人死亡。在这种情况下，身体对感染因子的反应涉及新描述的传感蛋白，我们认为这些蛋白对防御损伤至关重要。该提案旨在了解这些防御蛋白如何与感染因子反应以调节细胞死亡和炎症反应，特别是在脓毒症的背景下。