Cellular Determinants of Fibrin Structure and Stability

描述(申请人提供)：损伤后，携带组织因子(TF)的细胞暴露在血液中，引发血栓形成。血液凝块由纤维蛋白组成的网状网络稳定，纤维蛋白可以保护血块免受血液流动的伤害。纤维蛋白在感染过程中也具有免疫功能，并有助于伤口愈合。研究表明，纤维蛋白网络的形成或质量(结构和/或稳定性)的异常是异常血液凝块(血栓形成和/或出血)的一个既定的独立危险因素。我们和其他人已经证明，不同的细胞通过它们的促凝血活性和受体表达来决定纤维蛋白的质量。有趣的是，细胞促凝血活性和受体都会产生纤维蛋白，这种纤维蛋白在细胞附近比远离细胞表面更致密和稳定。我们假设凝血酶生成的空间位置影响凝块的结构和稳定性。我们将使用激光扫描共聚焦显微镜来表征调节凝血起始部位近端和远端纤维蛋白凝块结构的活动。我们将专门研究细胞刺激、细胞和循环组织因子、可溶性凝血因子和细胞受体在决定凝块结构中的作用。我们将使用被动和磁性驱动的微珠技术和显微镜来研究血管细胞如何调节纤维蛋白网络的渗透性、机械强度和对纤溶的抵抗力。最后，我们将使用透射电子显微镜来比较在不同剪切率下在新鲜切除的人体血管上形成的凝块中的纤维蛋白结构。我们预计我们的数据将显示不同的止血和血栓前机制如何在静态和低剪切条件下对凝块结构和稳定性做出贡献。这些机制可能是预防血管内血栓和/或血栓形成的特定靶点。公共卫生相关性：不适当的血液凝块形成(血栓形成)是西方世界死亡和残疾的主要原因。了解导致血栓形成的机制对于开发预防这种毁灭性疾病的方法至关重要。

DESCRIPTION (provided by applicant): Following injury, tissue factor (TF)-bearing cells are exposed to the blood, triggering blood clot formation. Blood clots are stabilized by a web-like network of fibrin, which protects the clot from the rigors of flowing blood. Fibrin also has immunological functions during infection and contributes to wound healing. Studies have shown that abnormalities in the formation or quality (structure and/or stability) of the fibrin network are an established, independent risk factor for abnormal blood clots (thrombosis and/or bleeding). We and others have shown that different cells determine fibrin quality via their procoagulant activity and receptor expression. Interestingly, both cellular procoagulant activity and receptors produce fibrin that is denser and more stable near the cell than further away from the cell surface. We hypothesize that the spatial location of thrombin generation influences clot structure and stability. We will use laser scanning confocal microscopy to characterize activities that regulate fibrin clot structure proximal and distal to the site of clotting initiation. We will specifically investigate the roles of cell stimulation, cellular and circulating tissue factor, soluble clotting factors, and cell receptors in determining clot structure. We will use passive and magnetically-driven microbead techniques and microscopy to examine how vascular cells modulate fibrin network permeability, mechanical strength and resistance to fibrinolysis. Finally, we will use transmission electron microscopy to compare fibrin structure in clots formed under different shear rates on freshly-excised human vessels. We anticipate our data will show how different hemostatic and prothrombotic mechanisms contribute to clot structure and stability in static and low shear conditions. These mechanisms may be specific targets for preventing intravascular thrombosis and/or embolism. PUBLIC HEALTH RELEVANCE: Inappropriate blood clot formation (thrombosis) is the leading cause of death and disability in the Western world. Understanding the mechanisms leading to thrombosis is critical in order to develop approaches for preventing this devastating disease.