Heme toxicity and vaso-occlusion in sickle cell disease

镰状细胞病中的血红素毒性和血管闭塞

基本信息

批准号：
9240380
负责人：
Gregory M Vercellotti
金额：
$ 48.98万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-02-01 至 2021-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9240380
关键词：
Adhesions Affect Algorithms Alternative Complement Pathway Amino Acids Anaphylatoxins Antibodies Bacterial Infections Binding Binding Sites Biochemical Biological Assay Blood Cells Blood Platelets Blood Vessels Bone Marrow Bone Marrow Transplantation Breeding Cells Cessation of life Coagulation Process Complement Complement Activation Complement Inactivators Complex Computer Assisted Coupled Data Databases Development Endothelial Cells Endothelium Evaluation Foundations Functional disorder Funding Goals Heme Hemolysis Image Immune Inflammation Inflammatory Response Injury Innate Immune System Interruption Ischemia Lead Leukocytes Ligands Link Lipopolysaccharides Longevity Mediating Modeling Molecular Morbidity - disease rate Mus Myelogenous Natural Immunity Nuclear Organ Oxidants Oxidative Stress P-Selectin Pain Pathogenesis Pathology Pathway interactions Patients Pattern Peptides Phosphatidylserines Play Production Quality of life Reperfusion Therapy Reporter Research Role Sickle Cell Sickle Cell Anemia Sickle Hemoglobin Signal Pathway Signal Transduction Site-Directed Mutagenesis Surface TLR2 gene TLR4 gene Techniques Testing Tissues Toll-like receptors Toxic effect Translating Transplantation Vascular Diseases acute chest syndrome complement pathway complement system design effective therapy heme a improved in vivo inhibitor/antagonist insight mortality mouse model new therapeutic target novel therapeutics polymerization sickle cycle sickling small molecule targeted agent targeted treatment therapy development von Willebrand Factor

Adhesions Affect Algorithms Alternative Complement Pathway Amino Acids Anaphylatoxins Antibodies Bacterial Infections Binding Binding Sites Biochemical Biological Assay Blood Cells Blood Platelets Blood Vessels Bone Marrow Bone Marrow Transplantation Breeding Cells Cessation of life Coagulation Process Complement Complement Activation Complement Inactivators Complex Computer Assisted Coupled Data Databases Development Endothelial Cells Endothelium Evaluation Foundations Functional disorder Funding Goals Heme Hemolysis Image Immune Inflammation Inflammatory Response Injury Innate Immune System Interruption Ischemia Lead Leukocytes Ligands Link Lipopolysaccharides Longevity Mediating Modeling Molecular Morbidity - disease rate Mus Myelogenous Natural Immunity Nuclear Organ Oxidants Oxidative Stress P-Selectin Pain Pathogenesis Pathology Pathway interactions Patients Pattern Peptides Phosphatidylserines Play Production Quality of life Reperfusion Therapy Reporter Research Role Sickle Cell Sickle Cell Anemia Sickle Hemoglobin Signal Pathway Signal Transduction Site-Directed Mutagenesis Surface TLR2 gene TLR4 gene Techniques Testing Tissues Toll-like receptors Toxic effect Translating Transplantation Vascular Diseases acute chest syndrome complement pathway complement system design effective therapy heme a improved in vivo inhibitor/antagonist insight mortality mouse model new therapeutic target novel therapeutics polymerization sickle cycle sickling small molecule targeted agent targeted treatment therapy development von Willebrand Factor

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项目摘要

Hemolysis and the intravascular release of hemoglobin S are central to the pathophysiology of sickle cell disease (SCD). During the current funding period, we showed that heme derived from sickle red blood cells acts as a damage-associated molecular pattern that can activate toll-like receptor 4 (TLR4) of the innate immune system, independently of its cognate ligand lipopolysaccharide, leading to oxidant production, rapid P-selectin and von Willebrand factor expression on endothelium, and vaso-occlusion (VO) in SCD mice. We hypothesize that the innate immune system, including TLR4 and complement, is fundamental to understanding hemolysis-driven inflammation, coagulation, VO, and the cumulative organ pathology in SCD. The first aim of our proposal is to identify the heme- binding site on the myeloid differentiation factor 2 (MD-2)/TLR4 complex. To date, no studies have examined the heme-binding site on the MD-2/TLR4 complex. Identifying the heme-binding site on MD-2/TLR4 is vital for developing therapies to interrupt heme-driven inflammation and VO. The second aim will examine the impact of global Tlr4 deficiency and the specific contribution of TLR4 in leukocytes, platelets, and the vessel wall to SCD pathogenesis. Recent studies by our group and others used Tlr4-/-, non-sickle cell mice transplanted with Tlr4+/+ sickle bone marrow to underscore the importance of TLR4 in the vessel wall in promoting VO and acute chest syndrome in SCD. However, the impact of Tlr4 deficiency on inflammation, coagulation, and cumulative organ pathology has not been tested in a global Tlr4-/- SCD mouse model. We will test the hypothesis that TLR4 is a key signaling pathway that translates hemolysis into inflammation, VO, and organ pathology in SCD. Our third aim will examine the role of complement activation in SCD hemolysis, inflammation, and VO. The alternative complement pathway is abnormally activated in SCD and is amplified by phosphatidylserine on the outer leaflet of sickle red blood cells and microparticles. We will test the hypothesis that complement activation on the surface of sickle red blood cells and microparticles stimulates inflammation, coagulation, hemolysis, and VO in SCD. Using state-of-the-art molecular techniques including site-directed mutagenesis, bone marrow transplants, cellular/biochemical studies, breeding a unique sickle/Tlr4-deficient mouse model, and in vivo vascular imaging in murine models of SCD, we will provide the foundation for the development of new therapies targeting multiple pathways to interrupt SCD pathophysiology. Understanding TLR4 and complement activation in SCD is expected to lead to therapies targeting the heme-binding site on the MD-2/TLR4 complex and complement inhibitors that will improve the quality of life of SCD patients.

血红蛋白S的溶血和血管内释放是镰状病理生理学的核心细胞病（SCD）。在当前的资金期间，我们表明血红素是从镰状红色衍生的血细胞充当与损伤相关的分子模式，可以激活Toll样受体4 （TLR4）先天免疫系统，独立于其同源配体脂多糖，领先对于氧化剂的产生，内皮上的快速P-选择素和von Willebrand因子的表达，以及 SCD小鼠的血管封闭（VO）。我们假设先天免疫系统，包括TLR4 和补体是理解溶血驱动的炎症，凝结，vo，以及SCD中的累积器官病理学。我们提案的第一个目的是确定血红素髓样分化因子2（MD-2）/TLR4复合物上的结合位点。迄今为止，没有研究检查了MD-2/TLR4复合物上的血红素结合位点。在 MD-2/TLR4对于开发中断血红素驱动的炎症和VO的疗法至关重要。这第二个目标将研究全球TLR4缺乏症的影响以及TLR4在白细胞，血小板和血管壁为SCD发病机理。我们小组的最新研究以及其他人则使用TLR4 - / - ，用TLR4+/+镰刀骨髓移植的非icickle细胞小鼠来强调在促进SCD中促进VO和急性胸部综合征的血管壁中TLR4的重要性。然而， TLR4缺乏对炎症，凝结和累积器官病理学的影响尚未在全局TLR4 - / - SCD鼠标模型中进行了测试。我们将测试TLR4是关键的假设在SCD中将溶血，VO和器官病理转化为炎症，VO和器官病理的信号通路。我们的第三个目标将研究补体激活在SCD溶血，炎症和VO中的作用。替代补体途径在SCD中异常激活，并被放大镰状血细胞和微粒的外小叶上的磷脂酰丝氨酸。我们将测试假设补体在镰状红细胞和微粒表面激活刺激SCD中的炎症，凝结，溶血和VO。使用最先进的分子包括位置定向诱变，骨髓移植，细胞/生化的技术研究，繁殖独特的镰刀/TLR4缺陷小鼠模型，以及在鼠中的体内血管成像 SCD的模型，我们将为开发新疗法的靶向奠定基础中断SCD病理生理学的多种途径。了解TLR4并补充激活在SCD中，预计将导致针对MD-2/TLR4复合物上的血红素结合位点的疗法并补充将改善SCD患者生活质量的抑制剂。