BIOLOGICAL FUNCTIONS OF THROMBIN AND THROMBIN RECEPTORS

凝血酶是凝血级联反应中的关键调节酶 在细胞激活和趋化中起关键作用，以及 参与炎症、组织修复和神经细胞活性。 凝血酶对细胞的作用是通过凝血酶受体介导的 通过G蛋白偶联和蛋白质激活第二信使信号 磷酸化。测定凝血酶的生物学功能 体内的凝血酶受体，基因打靶将被用来创造 胚胎干细胞中这些蛋白质的遗传缺陷和 老鼠。这些模型将被用来研究细胞因子的生物学作用。 凝血酶和凝血酶受体在止血和造血方面的作用。 凝血酶原和凝血酶受体缺陷对细胞的影响 增殖和分化将直接分成两部分进行研究 基因敲除ES细胞和基因敲除小鼠。如果小鼠缺乏凝血酶原或 凝血酶受体不活，将使用双基因敲除ES细胞 准备嵌合小鼠以确定哪些组织可以 容忍这些蛋白质中的缺陷。免疫组织化学，一起 通过原位RNA杂交，将被用来表征 凝血酶原和凝血酶受体在正常人群中的表达 发育过程中的嵌合小鼠。凝血酶受体缺陷型ES细胞 来自缺陷小鼠的品系和组织将被研究以确定 是否可以识别更多的蛋白水解酶激活受体。这些 研究追求一种直接的方法来定义细胞的生物学功能 凝血酶原和凝血酶受体与生长发育和 止血。

Thrombin is a crucial regulating enzyme in the coagulation cascade and plays a critical role in cellular activation and chemotaxis, as well as being involved in inflammation, tissue repair and neural cell viability. Thrombin's effects on cells are mediated by the thrombin receptor, which evokes second messenger signaling through G-protein coupling and protein phosphorylation. To determine the biological functions of thrombin and the thrombin receptor in vivo, gene targeting will be used to create genetic deficiencies of these proteins in embryonic stem (ES) cells and mice. These models will be used to study the biological roles of thrombin and thrombin receptor in terms of hemostasis and hematopoiesis. The effects of prothrombin- and thrombin receptor-deficiencies on cell proliferation and differentiation will be studied directly in double knockout ES cells and knockout mice. If mice lacking prothrombin or the thrombin receptor are not viable, double knockout ES cells will be used to prepare chimeric mice to determine specifically which tissues can tolerate deficiencies in these proteins. Immunohistochemistry, together with in situ RNA hybridization, will be used to characterize the expressions of prothrombin and the thrombin receptor in normal or chimeric mice during development. Thrombin receptor deficient ES cell lines and tissues from deficient mice will be studied to determine whether additional protease activated receptors can be identified. These studies pursue a direct approach to define the biological functions of prothrombin and the thrombin receptor in growth, development and hemostasis.