Regulation of Toll-like Receptor 4 in Acute Inflammatory Disease

Toll 样受体 4 在急性炎症性疾病中的调控

• 批准号: 8088111
• 负责人: Justin Eddie Juskewitch
• 金额: $ 3.65万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8088111
• 关键词: Acetaminophen; Acute; Acute Hepatitis; Agonist; Biliary; Binding; Bone Marrow Transplantation; Burn Trauma; Cells; Controlled Environment; Data; Diagnostic; Digestive System Disorders; Dimerization; Disease; Disease model; Distal; Drug Delivery Systems; Endoglycosidases; Endotoxemia; Endotoxins; Enzymes; Event; Extracellular Matrix; Extracellular Matrix Degradation; Family; Functional disorder; Goals; Heparan Sulfate Proteoglycan; Hepatitis; In Vitro; Infection; Inflammation; Inflammatory; Laboratories; Ligand Binding; Liver; Measures; Mediating; Microbe; Mission; Modeling; Mus; NF-kappa B; North Carolina; Organ; Outcome; Pancreas; Pancreatic Diseases; Peptide Hydrolases; Process; Receptor Activation; Recombinants; Regulation; Reporter; Research; Research Support; Role; SLPI gene; Sepsis; Sepsis Syndrome; Serum; Stimulus; TLR4 gene; Testing; Tissues; Toll-like receptors; Universities; Work; acute pancreatitis; base; clinically relevant; cytokine; heparanase; in vivo; innovation; killings; microbial; monomer; new therapeutic target; novel; novel diagnostics; novel therapeutics; nutrition; prevent; public health relevance; receptor; receptor function; therapeutic target; toll-like receptor 4

DESCRIPTION (provided by applicant): Our laboratory's long-term goal is to discover how inflammation is triggered by microbial and non-microbial stimuli and to control that process therapeutically. Since Toll-like receptor (TLR) function appears central to inflammation and TLR4 function is regulated by extracellular matrix (ECM), the overall objective of this project is to determine how local environment controls inflammation and how this control may be breached to initiate the systemic inflammatory response syndrome (SIRS). Our central hypothesis is that inflammatory stimuli are suppressed in healthy tissue by intact ECM while ECM degradation in disease facilitates or triggers local inflammation and, potentially, SIRS. We plan to test this central hypothesis through two specific aims: 1) Identify TLR4 inhibiting component(s) of intact ECM in vitro; 2) Establish the in vivo role of intact ECM and its degradation in 3 murine models of SIRS (endotoxemia, cerulein-induced acute pancreatitis, acetaminophen-induced acijte hepatitis). We hypothesize that heparan sulfate proteoglycans in intact ECM directly tether TLR4 monomers and thus prevent receptor dimerization and activation by TLR4 agonists. Moreover, we hypothesize that early SIRS events in vivo (e.g., elevation of serum cytokines) are mediated by circulating cells that have little ECM contact. These cells activate enzymes that degrade tissue ECM. This ECM breakdown releases TLR4 expressed on parenchymal cells whose activation then leads to late SIRS events (e.g., distal organ dysfunction). We plan to achieve the first aim by using TLR4 positive and TLR4 negative HEK293 cells, ECM plates, and matrix-degrading agents generated in our laboratory or obtained commercially. We plan to achieve the second specific aim by generating several different chimeric TLR4 mice from TLR4 positive and TLR4 negative C57 NF-kB EGFP reporter mice obtained from University of North Carolina or generated in our laboratory respectively. These chimeric mice will undergo infectious and non-infectious models of SIRS and both early and late SIRS events will be measured. These studies will provide a mechanistic explanation for previous in vitro TLR4 observations and a generalizable model for systemic inflammation in several clinically relevant disease models. These results will also provide potential new therapeutic and diagnostic targets for SIRS. PUBLIC HEALTH RELEVANCE: These studies will describe how inflammation spreads from the liver and pancreas. This data could apply to many different diseases and give a general model for inflammation. This model would give new drug targets to treat inflammation.

描述（由申请人提供）：我们实验室的长期目标是发现微生物和非微生物刺激如何引发炎症，并在治疗上控制该过程。由于 Toll 样受体 (TLR) 功能似乎对炎症至关重要，而 TLR4 功能受细胞外基质 (ECM) 调节，因此该项目的总体目标是确定局部环境如何控制炎症以及如何破坏这种控制以引发全身炎症反应综合征 (SIRS)。我们的中心假设是，健康组织中的炎症刺激被完整的 ECM 抑制，而疾病中的 ECM 降解则促进或引发局部炎症，并可能引发 SIRS。我们计划通过两个具体目标来检验这一中心假设：1）在体外鉴定完整 ECM 的 TLR4 抑制成分； 2) 确定完整 ECM 的体内作用及其在 3 个 SIRS 小鼠模型（内毒素血症、雨蛙素诱导的急性胰腺炎、对乙酰氨基酚诱导的急性肝炎）中的降解。我们假设完整 ECM 中的硫酸乙酰肝素蛋白聚糖直接束缚 TLR4 单体，从而阻止 TLR4 激动剂受体二聚化和激活。此外，我们假设体内早期 SIRS 事件（例如血清细胞因子升高）是由与 ECM 接触很少的循环细胞介导的。这些细胞激活降解组织 ECM 的酶。这种 ECM 分解释放实质细胞上表达的 TLR4，其激活随后导致晚期 SIRS 事件（例如远端器官功能障碍）。我们计划通过使用我们实验室产生的或商业获得的 TLR4 阳性和 TLR4 阴性 HEK293 细胞、ECM 板和基质降解剂来实现第一个目标。我们计划通过从北卡罗来纳大学获得或我们实验室分别产生的TLR4阳性和TLR4阴性C57 NF-kB EGFP报告小鼠产生几种不同的嵌合TLR4小鼠来实现第二个具体目标。这些嵌合小鼠将经历感染性和非感染性 SIRS 模型，并且将测量早期和晚期 SIRS 事件。这些研究将为之前的体外 TLR4 观察提供机制解释，并为几种临床相关疾病模型中的全身炎症提供通用模型。这些结果还将为 SIRS 提供潜在的新治疗和诊断靶点。 公共健康相关性：这些研究将描述炎症如何从肝脏和胰腺传播。这些数据可以适用于许多不同的疾病，并给出炎症的通用模型。该模型将为治疗炎症提供新的药物靶点。