Effect of slip bonds due to type 2B von Willebrand Disease on platelet adhesion, aggregation, and contractile forces

2B 型冯维勒布兰德病导致的滑移键对血小板粘附、聚集和收缩力的影响

基本信息

批准号：
10525260
负责人：
Ava Marie Obenaus
金额：
$ 4.34万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-12-16 至 2023-12-15
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10525260
关键词：
Actins Adhesions Affect Affinity Area Binding Biological Assay Biomechanics Biophysics Blood Blood Coagulation Disorders Blood Platelet Disorders Blood Platelets Blood Proteins Blood specimen Calcium Signaling Cells Cytoskeleton Defect Development Diagnosis Diagnostic Procedure Exposure to Fibrillar Collagen Functional disorder Future Glass Glycoprotein Ib Glycoproteins Goals Hemorrhage Hemostatic function Individual Inherited Integrins Knowledge Measures Mechanics Mediating Methods Microfluidic Microchips Microfluidics Molecular Weight Mutate Mutation Myosin ATPase Nature Patients Phenotype Platelet Activation Platelet aggregation Play Population Process Reporting Research Role Site Surface Therapeutic Thrombocytopenia Thrombosis Thrombus Time Vascular Endothelium Whole Blood Work biomechanical test cantilever cost flexibility gain of function mutation improved interest lonely individuals novel diagnostics platelet function premature receptor response to injury shear stress transmission process vascular injury von Willebrand Disease von Willebrand Factor wound

项目摘要

PROJECT SUMMARY/ABSTRACT Von Willebrand Disease (VWD) is characterized by a defect in the blood protein von Willebrand Factor (VWF) and leads to uncontrolled bleeding. VWF is necessary for initial platelet tethering and subsequent platelet adhesion to the injured vasculature. Glycoprotein Ib (GPIb) is a receptor found on the platelet surface that recognizes the A1 domain of VWF. When the vascular endothelium is damaged, VWF binds to exposed fibrillar collagen and to GPIb, tethering the platelet to the surface. Then, cytoskeletal forces acting through integrin αIIBβ3 allow platelets to adhere and aggregate, forming a strong and stable platelet-rich plug. The GPIb-A1 bond forms under conditions of high shear and is characterized as a “catch” bond, meaning it has a longer lifetime under conditions of increased tensile force. In type 2B VWD, a gain-of-function mutation to VWF causes an increased affinity for platelet binding at low shear. The type 2B VWF mutation leads to spontaneous platelet binding and subsequently uncontrolled bleeding. Previous work has demonstrated that with type 2B VWD, VWF and GPIb no longer form a catch bond but instead a “slip” bond, which is characterized by a shorter bond lifetime under conditions of increased tensile force. Additionally, platelet cytoskeletal forces can act independently of integrin αIIBβ3 through the GPIb-A1 bond. However, prior work has failed to fully explain how slip bonds in type 2B VWD affect the mechanics of platelet adhesion and platelet plug formation. I hypothesize that changes in the force- lifetime relationship of GPIb-A1 bonds due to type 2B VWD will affect platelet adhesion and aggregation due to an inability to withstand cytoskeletal forces. Platelet adhesion and contractile force will be measured at the single platelet level using flexible, cantilever-like nanoposts, while the contractile force generated by a platelet aggregate will be quantified using a microfluidic device. Using these methods, I can characterize how the biomechanics of platelet plug formation are affected by type 2B VWD, further explaining the bleeding phenotype. In the future, this knowledge relating to hemostasis initiation can be utilized to diagnose or treat type 2B VWD.

项目概要/摘要冯·维勒布兰德病 (VWD) 的特点是血液蛋白质冯·维勒布兰德因子 (VWF) 缺陷并导致不受控制的出血，VWF对于初始血小板束缚和随后的血小板是必需的。糖蛋白 Ib (GPIb) 是在血小板表面发现的一种受体。识别 VWF 的 A1 结构域当血管内皮受损时，VWF 与暴露的纤维结合。胶原蛋白和 GPIb，将血小板束缚在表面，然后，细胞骨架力通过整合素 αIIBβ3 起作用。使血小板粘附和聚集，形成坚固且稳定的富含血小板的栓塞。在高剪切条件下，具有“捕获”键的特点，这意味着它在高剪切条件下具有更长的寿命在 2B 型 VWD 中，VWF 的功能获得性突变会导致张力增加。低剪切力下血小板结合的亲和力 2B 型 VWF 突变导致自发血小板结合和先前的研究已证明 2B 型 VWD、VWF 和 GPIb 会出现随后的不受控制的出血。不再形成捕获键，而是形成“滑移”键，其特点是在以下条件下键合寿命较短此外，血小板细胞骨架力可以独立于整合素发挥作用。 αIIBβ3 通过 GPIb-A1 键然而，先前的工作未能完全解释 2B 型 VWD 中的滑移键。影响血小板粘附和血小板栓子形成的机制。 2B型VWD导致的GPIb-A1键的寿命关系将影响血小板粘附和聚集由于无法承受细胞骨架力，将测量血小板粘附力和收缩力。在单个血小板水平上使用灵活的悬臂状纳米柱，而由a产生的收缩力使用微流体装置对血小板聚集体进行定量，我可以描述如何进行定量。血小板栓子形成的生物力学受到2B型VWD的影响，进一步解释了出血将来，与止血启动相关的知识可用于诊断或治疗类型。 2B 大众WD。