Coagulation Factor XII Recruitment and Activation During Thrombus Formation

血栓形成过程中凝血因子 XII 的募集和激活

基本信息

批准号：
10741964
负责人：
Pavan Bendapudi
金额：
$ 72.17万
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：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2028-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10741964
关键词：
Affinity Anticoagulation Binding Binding Sites Biological Assay Blood Coagulation Disorders Blood Platelets Cell Line Clinical Co-Immunoprecipitations Coagulation Process Competitive Binding Complex Cryoelectron Microscopy Data Deuterium Development Disease susceptibility Drug Targeting Electron Microscopy Enzyme Precursors Event Exhibits Factor XII Factor XII Deficiency Factor XIIa Fibrinolytic Agents Flow Cytometry Follow-Up Studies Generations Hemorrhage Hemostatic function Human Hydrogen In Vitro Integrin Binding Integrins Interferometry Knockout Mice Kringles Ligands Maps Mass Spectrum Analysis Mediating Membrane Proteins Molecular Molecular Conformation Negative Staining Pathway interactions Patients Phase Physiological Plasma Play Pre-Clinical Model Process Property Proteomics RGD (sequence)Reagent Recombinant Proteins Recombinants Reproducibility Research Personnel Risk Role Signal Transduction Site Solid Surface Therapeutic Thrombosis Thrombus Treatment Efficacy Work experimental study factor A follow-up in vivo inhibitor insight interest microscopic imaging mouse model novel novel strategies novel therapeutics particle prevent receptor reconstitution recruit stem targeted agent therapeutic target thrombotic vascular injury

项目摘要

PROJECT SUMMARY An antithrombotic medication not associated with increased hemorrhage would be a transformative advance in the treatment of coagulation disorders. Inhibiting coagulation factor XII (FXII) has emerged as a therapeutic strategy that could “decouple” hemostasis from thrombosis to achieve antithrombotic efficacy without bleeding complications. Enthusiasm for FXII as a therapeutic target stems from the observation that severe congenital FXII deficiency is not associated with a bleeding diathesis while blockade or deletion of FXII in preclinical models consistently protects against thrombosis. However, despite its potential clinical importance, the mechanisms underlying platelet-dependent FXII activation in vivo remain unclear. Using a mass spectrometry-based proteomic screen, we have identified integrin αIIbβ3 as the putative platelet receptor for FXII. These results have been followed up with a number of additional studies reproducibly demonstrating the FXII-αIIbβ3 interaction and localizing the integrin binding region to the kringle domain (KD) of the FXII heavy chain. Our central hypothesis is that binding of FXII zymogen to platelet integrin αIIbβ3 potentiates FXII activation and is necessary and sufficient for FXII-mediated coagulation. In Aim 1 of this proposal, we will map the region(s) of the FXII KD responsible for binding to αIIbβ3 via competitive inhibition assays using recombinantly-generated fragments of the KD. We will also evaluate the role of the FXII KD in a mouse model of thrombosis to determine if loss of the KD can prevent thrombus formation in vivo. In Aim 2, we will work closely with our collaborators to conduct precision structural studies of the FXII-αIIbβ3 complex. In Aim 3, we will focus on the mechanisms by which FXII binding to αIIbβ3 leads to activation of FXII and downstream coagulation. The proposed work will provide important new insights into the molecular mechanism of FXII recruitment, activation, and propagation at the platelet surface and inform efforts to develop novel therapeutics based on inhibition of the FXII-αIIbβ3 complex.

项目摘要与出血无关的抗血栓药物将是一种变革性的进步凝血疾病的治疗。抑制凝血因子XII（FXII）已成为一种治疗可能会从血栓形成中“解除”止血以达到抗血栓效率而不会出血而止血的策略并发症。 FXII作为治疗靶点的热情源于严重先天性的观察 FXII缺乏症与临床前模型中FXII的dise或缺失无关始终防止血栓形成。但是，其潜在的临床重要性是机制基本的血小板依赖性FXII在体内尚不清楚。使用基于质谱的蛋白质组学筛选，我们已经确定整联蛋白αIIBβ3是FXII的假定血小板受体。这些结果有随后进行了许多其他研究，可重复证明FXII-αiiBβ3相互作用和将整合素结合区域定位于FXII重链的Kringle结构域（KD）。我们的中心假设是FXII Zymogen与血小板整合素αIIBβ3电位FXII激活的结合，是必要且充分的用于FXII介导的凝结。在本提案的目标1中，我们将绘制FXII KD负责的区域使用重组生成的KD片段，通过竞争性抑制测定法与αIIBβ3结合。我们还将评估FXII KD在血栓形成小鼠模型中的作用，以确定KD的丢失是否可以预防体内血栓形成。在AIM 2中，我们将与我们的合作者紧密合作以进行精确 FXII-αIIBβ3复合物的结构研究。在AIM 3中，我们将重点放在FXII结合的机制上到αIIBβ3导致FXII和下游凝血的激活。拟议的工作将提供重要的新对FXII募集，激活和在血小板表面的传播的分子机制的见解并为基于FXII-αIIBβ3复合物的抑制而开发新疗法的努力。