Sterile Hepatic Inflammation

无菌性肝脏炎症

• 批准号: 7929861
• 负责人: WAJAHAT Zafar MEHAL
• 金额: --
• 依托单位: VA CONNECTICUT HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7929861
• 关键词: Acetaminophen; Alcoholic Hepatitis; Antigens; Apoptotic; Caspase-1; Cells; Cessation of life; DNA; Development; Disease; Drug toxicity; Endothelial Cells; Event; Funding; Grant; Hepatic; Hepatitis; Hepatocyte; Hepatotoxicity; Immune response; Infection; Inflammation; Inflammatory; Inflammatory Response; Injury; Interleukin-18; Knowledge; Liver; Liver diseases; Mitochondrial DNA; Molecular; Necrosis; Nuclear; Nucleic Acids; Pathway interactions; Pattern; Population; Production; Reperfusion Injury; Role; Signal Pathway; Signal Transduction; Sterility; TLR7 gene; Testing; Therapeutic; Toxic effect; Transcript; Up-Regulation; Urate; abstracting; base; cytokine; design; improved; in vivo; microbial; mouse model; non-alcoholic; nonalcoholic steatohepatitis; novel strategies; pathogen; problem drinker; protein complex; receptor

DESCRIPTION (provided by applicant): Project Summary/Abstract Pathological hepatocyte death results in a sterile inflammatory response (SIR) which amplifies the original liver injury. The SIR is an important component of injury in a wide range of diseases including acetaminophen (APAP) hepatotoxicity, as well as alcoholic and non-alcoholic steatohepatitis. The molecular mechanisms responsible for sterile inflammation in the liver are largely unknown. Hypothesis. There is a two signal requirement for the development of sterile inflammation in the liver: Signal 1) Activation of TLR 7 and 9 by mammalian nucleic acids resulting in up-regulation of pro-IL-1b and pro-IL-18 and signal 2) Activation of the inflammasome and caspapse-1 for cleavage of pro-IL-1b and pro-IL-18, and secretion of active cytokines. To examine these issues, we have used the mouse model of APAP hepatotoxicity and show that: i) IL- 1b and IL-18 are required for full APAP hepatotoxicity. ii) Activation of TLR7 and 9 is required for up-regulation of pro-IL-1b and pro-IL-18 transcripts in the liver and full APAP hepatotoxicity. iii) DNA from apoptotic hepatocytes can activate TLR9 on sinusoidal endothelial cells, and cause liver injury. iv) Components of the inflammasome (NLRP3, ASC, caspase-1) are required for full APAP hepatotoxicity. Based on this background we propose the following objectives: 1: Identify the interactions between mammalian nucleic acids and TLR 7 and 9 which result in up- regulation of pro-IL-1b and pro-lL-18. 1a) Test if ssRNA and nuclear and mitochondrial DNA from healthy, necrotic and apoptotic hepatocytes can up-regulate pro-IL-1b and pro-lL-18 in liver cell populations. 1b) Test if TLR 7 and 9 signaling is required for the effects seen in 1a. 1c) Identify the signaling pathways fromTLR7 and TLR9 which result in up-regulation of pro-IL-1b and pro-IL-18. 1d) Test if TLR7 and 9 are sufficient or required for inflammasome activation. 2: Identify the mechanisms of activation of the NLRP3 inflammasome. 2a) Determine the role of ATP and monosodium urate (MSU) in inflammasome activation in liver cell populations. 2b) Determine the role of the pannexin channel in-vivo in the APAP induced hepatic SIR. 2c) Determine the role of MSU in-vivo in the APAP induced hepatic SIR. PUBLIC HEALTH RELEVANCE: Project Narrative Chronic liver disease due to drug toxicity, alcoholic steatohepatitis (ASH), non-alcoholic hepatitis (NASH), hepatitis C and B are over-represented in the veteran population. This is due to a higher incidence of substance abuse, diabetes and exposure to needle sticks and blood products. This results in a very high degree of morbidity due to fatigue, jaundice, ankle swelling and pruritis. In addition this also results in increased mortality due to cirrhosis, hepatocellular cancer as well as liver failure. Currently there are no effective treatments these liver diseases. This is due to the fact that we have a very poor understanding of how liver inflammation and injury start in these conditions. We propose to identify the molecules in the TLR and inflammasome pathways, which are required to start the process of liver inflammation and injury. The knowledge gained from this project will therefore directly result in designing rational therapies for these conditions.

描述（由申请人提供）： 项目摘要/摘要病理性肝细胞死亡会导致无菌炎症反应 (SIR)，从而放大原有的肝损伤。 SIR 是多种疾病损伤的重要组成部分，包括对乙酰氨基酚 (APAP) 肝毒性以及酒精性和非酒精性脂肪性肝炎。导致肝脏无菌性炎症的分子机制在很大程度上尚不清楚。假设。肝脏中发生无菌性炎症需要两个信号： 信号 1) 哺乳动物核酸激活 TLR 7 和 9，导致 IL-1b 前体和 IL-18 前体上调；信号 2)激活炎症小体和 caspapse-1，裂解 pro-IL-1b 和 pro-IL-18，并分泌活性细胞因子。 为了研究这些问题，我们使用了 APAP 肝毒性的小鼠模型，并表明： i) 完全 APAP 肝毒性需要 IL-1b 和 IL-18。 ii) TLR7 和 9 的激活是肝脏中 pro-IL-1b 和 pro-IL-18 转录物上调以及完全 APAP 肝毒性所必需的。 iii) 凋亡肝细胞的DNA可以激活肝窦内皮细胞上的TLR9，并引起肝损伤。 iv) 完整的 APAP 肝毒性需要炎性小体的成分（NLRP3、ASC、caspase-1）。基于这一背景，我们提出以下目标： 1：鉴定哺乳动物核酸与TLR 7和9之间的相互作用，其导致IL-1b原和IL-18原的上调。 1a) 测试来自健康、坏死和凋亡肝细胞的 ssRNA 以及核 DNA 和线粒体 DNA 是否可以上调肝细胞群中的 pro-IL-1b 和 pro-IL-18。 1b) 测试 1a 中所见的效果是否需要 TLR 7 和 9 信号传导。 1c) 鉴定导致 IL-1b 前体和 IL-18 前体上调的 TLR7 和 TLR9 信号传导途径。 1d) 测试 TLR7 和 9 是否足以或是炎性体激活所必需的。图 2：确定 NLRP3 炎症小体的激活机制。 2a) 确定 ATP 和尿酸钠 (MSU) 在肝细胞群炎症小体激活中的作用。 2b) 确定体内 pannexin 通道在 APAP 诱导的肝脏 SIR 中的作用。 2c) 确定 MSU 体内在 APAP 诱导的肝脏 SIR 中的作用。 公共卫生相关性： 项目叙述 由于药物毒性、酒精性脂肪性肝炎 (ASH)、非酒精性肝炎 (NASH)、丙型肝炎和乙型肝炎导致的慢性肝病在退伍军人群体中所占比例过高。这是由于药物滥用、糖尿病以及接触针刺和血液制品的发生率较高。由于疲劳、黄疸、踝关节肿胀和瘙痒，这导致非常高的发病率。此外，这还导致肝硬化、肝细胞癌以及肝功能衰竭导致的死亡率增加。 目前这些肝脏疾病还没有有效的治疗方法。这是因为我们对这些情况下肝脏炎症和损伤如何开始的了解非常少。我们建议鉴定 TLR 和炎症小体途径中的分子，这些分子是启动肝脏炎症和损伤过程所必需的。因此，从该项目中获得的知识将直接导致为这些病症设计合理的疗法。