Thrombin signaling in Hemostatis and thrombosis

我的实验室的一个中心目标是确定凝血酶如何调节细胞行为， 止血，血栓形成，炎症和其他过程，并阐明凝血酶信号转导的作用， vivo.该补助金的重点是止血和血栓形成。我们之前的工作表明蛋白酶- 活化受体（PAR）是凝血酶活化血小板所必需的，对血栓形成很重要， 在小鼠模型中止血。这些和其他研究支持探索PAR拮抗作用， 预防或治疗人体血栓形成。我们现在提出的研究，以确定的作用，PAR在 更详细地，并确定凝血酶信号如何与其他血小板活化和凝血整合， 体内机制我们要问：1）vWF、胶原和凝血酶是血小板聚集的主要引发剂吗？ 体内激活？这些途径如何相互作用？使用复杂的小鼠模型，我们将测试 假设GPIb和GP-VI信号传导对于驱动血小板粘附是必要且充分的， 损伤部位血栓形成，但PAR信号是血栓传播所必需的。 血栓远离血管壁。将使用遗传学和药理学方法。PAR相互作用 与P2 Y12和Tbxa 2 r（TP）的反应也将被探测。2)凝血酶诱导的血小板活化和纤维蛋白 在止血和血栓形成中相互作用？当凝血酶时，它们的相对重要性是否会改变 生成或活动是否减少或受到抑制？我们将确定凝血酶是否能激活血小板， 对于远离血管壁的凝血酶生成和纤维蛋白形成的传播是重要的。我们将 我还想知道在低凝血酶生成的情况下PAR信号的中断是否具有协同效应 血栓形成或止血。3)组织因子表达在内皮和造血中的作用是什么？ 细胞止血和血栓形成？内毒素血症？这种组织因子的作用是否可以被发现， 通过敲除凝固传播的替代机制来放大？组织因子表达 将在内皮和造血组织中消融，以探测“循环组织”的来源和作用 因素”。这些研究将阐明止血和血栓形成的关键效应物如何相互作用。

A central goal of my laboratory has been to determine how thrombin regulates cellular behaviors involved in hemostasis, thrombosis, inflammation and other processes, and to elucidate the roles of thrombin signaling in vivo. This grant has focused on hemostasis and thrombosis. Our previous work showed that protease- activated receptors (PARs) are necessary for platelet activation by thrombin and important for thrombosis and hemostasis in mouse models. These and other studies support exploration of PAR antagonism for the prevention or treatment of thrombosis in humans. We now propose studies to define the roles of PARs in more detail and to determine how thrombin signaling integrates with other platelet activation and coagulation mechanisms in vivo. We shall ask:1) Are vWF, collagen and thrombin the major initiators of platelet activation in vivo? How do these pathways interact? Using sophisticated mouse models, we will test the hypothesis that GPIb and GP-VI signaling is necessary and sufficient to drive platelet adhesion and juxtamural thrombus formation at a site of injury but that PAR signalingis necessary for propagation of the thrombus away from the vessel wall. Genetic and pharmacological approaches will be used. PAR interactions with P2Y12 and Tbxa2r (TP) will also be probed. 2) How do thrombin-inducedplatelet activation and fibrin formation interact in hemostasis and thrombosis? Does their relative importance change when thrombin generation or activity is reduced or inhibited? We shall determine whether platelet activation by thrombin is important for propagation of thrombin generation and fibrin formation away from the vessel wall. We shall also ask whether disruption of PAR signalingin the setting of low thrombin generation has synergistic effects on thrombosis or hemostasis. 3) What is the role of tissue factor expression in endothelial and hematopoietic cells in hemostasis and thrombosis? In endotoxemia? Can roles for such tissue factor be uncovered or amplified by knockout of alternative mechanisms for propagation of coagulation? Tissue factor expression will be ablated in endothelial and hematopoietic tissues to probe the source and roles of "circulatingtissue factor". These studies will illuminate how key effectors of hemostasis and thrombosis interact.