Thrombin signaling in Hemostatis and thrombosis

我的实验室的中心目标一直是确定凝血酶如何调节细胞行为 止血，血栓形成，炎症等过程，并阐明凝血酶信号在 活着。这笔赠款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(PARs)是凝血酶激活血小板所必需的，对血栓形成和 小鼠模型的止血作用。这些研究和其他研究支持探索PAR拮抗 预防或治疗人类的血栓形成。我们现在建议进行研究，以确定PAR在 更多细节，并确定凝血酶信号如何与其他血小板激活和凝血结合 体内机制。我们会问：1)vWF、胶原和凝血酶是血小板的主要起始物吗？ 活体内激活？这些途径是如何相互作用的？使用复杂的鼠标模型，我们将测试 假设GPIB和GP-VI信号是驱动血小板黏附和 在损伤部位形成动脉壁旁血栓，但PAR信号是传播血栓所必需的 血栓远离血管壁。将使用遗传和药理学方法。PAR交互作用 对P2Y12和Tbxa2r(TP)也进行了探讨。2)凝血酶诱导的血小板活化和纤维蛋白 形成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改变？ 代谢物或活性减少或抑制？我们将确定凝血酶激活血小板是否 对于远离血管壁的凝血酶生成和纤维蛋白形成的传播很重要。我们会 还要询问在凝血酶生成较低的情况下，PAR信号的中断是否具有协同效应 血栓形成或止血。3)组织因子在内皮和造血细胞中的表达有何作用 止血和血栓形成中的细胞？内毒素血症？这种组织因子的作用能否被发现或 被凝血传播的替代机制敲除而放大？组织因子表达 将消融于血管内皮细胞和造血组织中，以探讨其来源和作用 这些研究将阐明止血和血栓形成的关键影响因素是如何相互作用的。

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.