Role of biliverdin reductase during sterile inflammation in the liver.

胆绿素还原酶在肝脏无菌炎症过程中的作用。

基本信息

批准号：
9030443
负责人：
Barbara Wegiel
金额：
$ 39.15万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-01-01 至 2020-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9030443
关键词：
Acetaminophen Acute Alleles Anti-Inflammatory Agents Anti-inflammatory Bile Pigments Bilirubin Biliverdin reductase Biliverdine Binding Catabolism Catalysis Cell Death Cell Membrane Proteins Cell membrane Cell surface Cells Cessation of life Complex Cytochromes DNA DNA Binding DNA delivery Data Enzymes Exhibits Feedback Genetic Transcription HMGB1 gene Health Heat-Shock Response Heme IRF3 gene Immune response In Vitro Infiltration Inflammation Inflammation Mediators Inflammatory Inflammatory Response Injury Injury to Liver Interleukin-1 beta Interleukin-6 Ischemia Knockout Mice Lead Liver Macrophage Activation Mediating Mediator of activation protein Metabolic Mitochondria Mitochondrial DNA Modeling Molecular Mouse Strains Necrosis Nuclear Operative Surgical Procedures Organ Organ failure Oxygenases Pathway interactions Pattern Pattern recognition receptor Pharmaceutical Preparations Production Proteins Rattus Reperfusion Therapy Role Scheme Shock Signal Pathway Signal Transduction Signaling Molecule Sterility Surface TLR4 gene TLR9 gene TNF gene Testing Therapeutic Trauma Xenobiotics Zinc Fingers acetaminophen overdose clinical practice cytokine cytotoxic extracellular heme oxygenase-1 in vivo liver injury macrophage microbial novel pathogen prevent receptor response response to injury sensor trafficking transcription factor

项目摘要

DESCRIPTION (provided by applicant): Sterile inflammation is caused by injury, infiltration and activation of inflammatory cells in the absence of a pathogen and is an acute response to organ injury after cell necrosis, however if uncontrolled can lead to organ failure and death. Among the Danger Associated Molecular Patterns (DAMPs) that are released from the necrotic cells is mitochondrial (mt) and nuclear DNA, which are recognized by toll like receptor 9 (TLR9). Sterile inflammation in response to cellular necrosis mimics microbial inflammation and is regulated by multiple signaling pathways including heme degradation enzymes: heme oxygenase-1 (HO-1) and biliverdin reductase (BVR). Biliverdin reductase (BVR) is a metabolic enzyme whose principal function is to convert biliverdin (BV) to bilirubin (BR), however BVR is also expressed on the cell surface (BVRsurf) where it can function as a receptor and activate PI3K-Akt signaling in macrophages. In this proposal, we hypothesize that BVRsurf also serves as a novel pattern recognition receptor-like protein, and can interact with extracellular mtDNA fragments to mediate and amplify pro-inflammatory signaling in macrophages. Bile pigments have been shown to prevent shock-induced liver injury as well as protected against acetaminophen (APAP) injury in rats. The immunomodulatory function of BVR has not been tested in vivo in response to liver injury due to lack of available knockout mice. We have now generated BVRflfl conditional knockout mice and demonstrated that deletion of BVR in macrophages results in inhibition of DNA-mediated signaling in macrophages. Part of our hypothesis is that BVR binds extracellular mtDNA and delivers it to TLR9 intracellular. The major focus of this application is to elucidate the ability of BVRsurf to acts as a receptor for extracellular mtDNA fragments and therefore mediate part of the responses in macrophages during sterile inflammation. Specifically, in this proposal we intend to: 1. Investigate a role of BVR in models of sterile inflammation in the liver using a novel strain of BVRflfl with conditional deletion of BVR in macrophages (CreLyz:BVRflfl). 2. Evaluate the potential therapeutic role of bile pigments in sterile inflammation models to suppress inflammation by directly impacting BVRsurf activity. 3. Study a detail mechanism of BVR and bile pigments in macrophages. We will test whether mtDNA-BVR interaction results in activation of its downstream signaling. We will test whether BVRsurf binds mtDNA fragments independent of the ecto-enzymatic activity and whether and how BVRsurf expression, BVRsurf:DNA interaction, trafficking and signaling are influenced by extracellular bile pigments. In summary, this study will unravel the novel mechanisms of BVR and bile pigments in macrophages that contribute to innate immune responses during pathogen-free associated inflammation in the liver.

描述（申请人提供）：无菌性炎症是在没有病原体的情况下由炎症细胞损伤、浸润和活化引起的，是细胞坏死后对器官损伤的急性反应，但如果不加以控制，可导致器官衰竭和死亡。坏死细胞释放的危险相关分子模式 (DAMP) 是线粒体 (mt) 和核 DNA，可被 Toll 样受体 9 (TLR9) 识别。细胞坏死引起的无菌炎症类似于微生物炎症，并受到多种信号通路的调节，包括血红素降解酶：血红素加氧酶-1 (HO-1) 和胆绿素还原酶 (BVR)，胆绿素还原酶 (BVR) 是一种代谢酶，其主要功能是。是将胆绿素 (BV) 转化为胆红素 (BR)，但是 BVR 也表达在细胞表面 (BVRsurf)，它可以作为受体发挥作用，并且激活巨噬细胞中的 PI3K-Akt 信号传导在本提案中，我们发现 BVRsurf 还可以作为一种新型模式识别受体样蛋白，并且可以与细胞外 mtDNA 片段相互作用，介导和放大巨噬细胞中的促炎信号传导。在大鼠中，BVR 的免疫调节功能尚未在体内测试，以应对休克引起的肝损伤，并可防止对乙酰氨基酚 (APAP) 损伤。由于缺乏可用的基因敲除小鼠，我们现在已经生成了 BVRflfl 条件敲除小鼠，并证明巨噬细胞中 BVR 的缺失会导致巨噬细胞中 DNA 介导的信号传导受到抑制，我们的部分假设是 BVR 结合细胞外 mtDNA 并将其传递至细胞内 TLR9。该应用的主要重点是阐明 BVRsurf 作为细胞外 mtDNA 片段受体的能力，从而介导无菌期间巨噬细胞的部分反应具体而言，在本提案中，我们打算： 1. 使用具有条件的新型 BVRflfl 菌株研究 BVR 在肝脏无菌炎症模型中的作用。巨噬细胞中 BVR 的缺失 (CreLyz:BVRflfl)。 2. 评估胆汁色素在无菌炎症模型中通过直接影响 BVRsurf 活性来抑制炎症的潜在治疗作用。我们将研究巨噬细胞中 BVR 和胆汁色素的详细机制。测试 mtDNA-BVR 相互作用是否导致其下游信号的激活我们将测试 BVRsurf 是否独立于 mtDNA 片段结合。胞外酶活性以及 BVRsurf 表达、BVRsurf：DNA 相互作用、运输和信号传导是否以及如何受到细胞外胆汁色素的影响总而言之，本研究将揭示巨噬细胞中 BVR 和胆汁色素促进先天免疫反应的新机制。肝脏中无病原体相关的炎症。