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

• 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
• 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

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.

项目摘要/摘要 冯·威勒布兰氏病（VWD）的特征是血液蛋白von willebrand因子（VWF）缺陷 并导致不受控制的出血。 VWF对于初始血小板绑扎和随后的血小板是必需的 对受伤的脉管系统的粘附。糖蛋白IB（GPIB）是在血小板表面发现的一种受体 识别VWF的A1域。当血管内皮受损时，VWF与暴露的纤维结合 胶原蛋白和GPIB，将血小板绑在表面上。然后，通过整联蛋白αIIBβ3作用的细胞骨架力 允许血小板粘附并聚集，形成强大而稳定的血小板插头。 GPIB-A1债券形式 在高剪切的条件下，被描述为“捕获”键，这意味着它的寿命更长 拉伸力增加的条件。在2B型VWD中，功能奖励突变导致增加 在低剪切时血小板结合的亲和力。 2B型vWF突变导致赞助血小板结合和 随后不受控制的出血。先前的工作表明，使用2B型VWD，VWF和GPIB 不再形成捕获键，而是“滑动”键，其特征是较短 拉伸力增加的条件。此外，血小板细胞骨架力可以独立起作用整合素 αIIBβ3通过GPIB-A1键。但是，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塞形成的力学。我假设力量的变化 - GPIB-A1债券与2B类VWD有关的终身关系会影响血小板广告和聚合 由于无法承受细胞骨架力。将测量血小板粘附和收缩力 在单个血小板级别使用柔性，类似悬臂的纳米管，而收缩力是由A产生的 血小板聚集体将使用微流体设备进行量化。使用这些方法，我可以表征 血小板塞形成的生物力学受2B型VWD的影响，进一步解释了出血 表型。将来，这种与止血倡议有关的知识可用于诊断或治疗类型 2B VWD。