Role of von Willebrand Factor in Platelet Thrombus Formation

血管性血友病因子在血小板血栓形成中的作用

• 批准号: 7768171
• 负责人: Zaverio M Ruggeri
• 金额: $ 47.48万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-18 至 2010-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7768171
• 关键词: Acute; Address; Adhesions; Adhesives; Animals; Applications Grants; Binding; Biochemistry; Bleeding time procedure; Blood; Blood Platelets; Blood Vessels; Blood flow; Cellular biology; Clinical; Collaborations; Collagen; Complex; Development; Diagnosis; Disease; Elements; Event; Exhibits; Functional disorder; Funding; Gene Mutation; Glycoproteins; Goals; Hemostatic function; Human; Immune system; Immunoglobulin G; Injury; Lead; Length; Link; Measures; Mediating; Membrane; Modeling; Molecular; Mouse Strains; Mus; Mutation; Nature; Physiological; Plasma; Platelet Activation; Platelet aggregation; Play; Population; Process; Property; Proteins; Proteolysis; Publishing; Regulation; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Solutions; Structure; Surface; Tail; Testing; Thrombin; Thrombosis; Thrombus; Vascular Diseases; atherothrombosis; base; cross reactivity; design; dimer; improved; in vivo; in vivo Model; novel; physical state; programs; public health relevance; receptor; research study; response; shear stress; stem; structural biology; von Willebrand Factor

DESCRIPTION (provided by applicant): The studies proposed in this application continue efforts to elucidate von Willebrand factor (VWF) in the VWF A1 domain (VWFA1) can differentially regulate specific adhesive functions. Experimental evidence indicates that the interaction of glycoprotein (GP) Ib1 with VWFA1 immobilized onto a surface, leading to platelet adhesion, or in solution, mediating platelet aggregation, may occur through different mechanisms. Our goal is to define the distinctive structural determinants underlying the initiation and regulation of these diverse VWF activities and establish their functional relevance in models of vascular injury. In aim 2 we intend to ascertain whether 1-thrombin is a physiologic modulator of VWF adhesive properties. We hypothesize that VWFA1 and 1-thrombin establish inter- molecular contacts when bound to the same GPIb1 receptor, and this influences the stability of the VWFA1-GPIb1 bond independently of shear stress. We propose to identify the VWFA1 residues that support the interaction with GPIb1-bound 1-thrombin, thus defining a novel mechanism for the regulation of VWF function during thrombogenesis. In aim 3 we propose to evaluate whether a specific IgG found in the human population is a modulator of VWF activity. We have identified in human and mouse blood a specific IgG that binds selectively to VWFA1, and obtained preliminary evidence that this IgG may play a role in thrombus formation. Our goal is to characterize the structure of the specific IgG, define the mode of interaction with VWFA1 and obtain definitive in vivo evidence for its physiopathological significance. In aim 4 we intend to define the signaling function of collagen- bound VWF leading to platelet activation. We have characterized the distinctive intracytoplasmic Ca++ signals that follow platelet adhesion to immobilized VWFA1 or collagen under flow conditions, and found that they are enhanced when platelets interact with collagen-bound VWF. We propose to dissect the mechanisms of platelet activation supported by the collagen-VWF complex and the effects of hydrodynamic force on the process. The results of this research will improve our ability to influence disease processes that involve platelets in atherothrombosis. PUBLIC HEALTH RELEVANCE: Experimental and clinical evidence points to a key role of VWF in thrombus formation, orchestrated by interactions with other proteins and modulated through forces generated by flowing blood. Understanding these different functions requires addressing structural details as well as verification of concepts in intravidal models. This will lead to a better diagnosis and treatment for cardio- and cerebro-vascular diseases.

描述（由申请人提供）：本申请中提出的研究继续努力阐明VWF A1域（VWFA1）中的von Willebrand因子（VWF）可以差异地调节特定的粘合功能。实验证据表明，糖蛋白（GP）IB1与固定在表面上的VWFA1的相互作用，导致血小板粘附或溶液中介导血小板聚集的溶液可能通过不同的机制发生。我们的目标是定义这些不同VWF活动的启动和调节的独特结构决定因素，并在血管损伤模型中建立其功能相关性。在AIM 2中，我们打算确定1-凝血酶是否是VWF胶粘性能的生理调节剂。我们假设VWFA1和1-凝血酶在与同一GPIB1受体结合时建立分子间接触，这会影响vWFA1-GPIB1键的稳定性，独立于剪切应力。我们建议确定支持与GPIB1结合1-凝血酶相互作用的VWFA1残基，从而定义了在血栓形成过程中调节VWF功能的新机制。在AIM 3中，我们建议评估人口中发现的特定IgG是否是VWF活动的调节剂。我们已经在人和小鼠血液中鉴定出一种特定的IgG，该特异性IgG与VWFA1有选择性结合，并获得了该IgG可能在血栓形成中起作用的初步证据。我们的目标是表征特定IgG的结构，定义与VWFA1相互作用的模式，并获得其生理病理学意义的体内证据。在AIM 4中，我们打算定义胶原蛋白结合VWF的信号传导功能，从而导致血小板激活。我们已经表征了与固定的VWFA1或胶原蛋白在流动条件下遵循血小板粘附的独特性内Ca ++信号，并发现当血小板与胶原蛋白结合的VWF相互作用时，它们会得到增强。我们建议剖析胶原蛋白-VWF复合物支持的血小板激活机制，以及流体动力对过程的影响。这项研究的结果将提高我们影响涉及血小板中血小板的疾病过程的能力。 公共卫生相关性： 实验和临床证据表明，VWF在血栓形成中的关键作用，通过与其他蛋白质相互作用，并通过流动血液产生的力调节。了解这些不同的功能需要解决结构细节以及经体模型中概念的验证。这将导致对心脏和脑血管疾病的更好诊断和治疗。