CELL MEDIATED HEMOSTASIS

描述(申请人逐字描述)：这一提议背后的假设是，指导凝血反应的是细胞，而不是蛋白质。 其推论是：1)激活的凝血的细胞位置 因素决定了它们在凝固级联中的作用；和2)特定的 不同细胞类型的特征，如特定受体的存在， 确定细胞的抗凝和促凝血特性。这些研究将 使用我们开发的基于细胞的混凝模型系统。我们有 拟议的研究属于四个具体目标。第一个目的是检查 活化蛋白C对内皮细胞的作用与 它对磷脂小泡或活化的血小板的活性。这些研究 将使用具有裂解位点突变的因子V分子。我们还将 看看因子V和因子V的切割形式作为一个 激活蛋白C灭活第VIII因子的辅因子。第二个目的 研究细胞组织因子活性是如何被控制的。这些研究将 看看组织因子加密和解密，氧化剂在 改变细胞组织因子活性及组织因子的作用 途径抑制物与抗凝血酶病在组织因子V1a/组织失活中的作用 因子复合体。第三个目标是检查什么因素决定了比率和 激活的血小板上产生的凝血酶的量。这些研究将检验 限制血小板表面凝血酶生成的机制。第四次 Aim研究了在基于细胞的模型中产生的凝血酶数量是如何 与体内稳定止血凝块的形成有关吗？这些研究 将检查纤维蛋白原结构和对溶解的敏感性，以及 凝血酶激活的纤溶抑制物的作用。

DESCRIPTION (Applicant's Description Verbatim): The hypothesis underlying this proposal is that cells, rather than proteins, direct the coagulation reactions. Corollaries of this are: 1) the cellular location of the activated coagulation factors determines their function in the coagulation cascade; and 2) specific features of different cell types, such as the presence of specific receptors, determine the anti- and pro-coagulant features of the cells. These studies will use a cell based model system of coagulation we have developed. We have proposed studies that fall within four specific aims. The first aim examines how the function of activated protein C on endothelial cells is different from its activity on phospholipid vesicles or activated platelets. These studies will use factor V molecules that have cleavage site mutations. We will also look at the ability of factor V and cleaved forms of factor V to act as a cofactor for activated protein C inactivation of factor VIII. The second aim examines how cellular tissue factor activity is controlled. These studies will look at tissue factor encryption and de-encryption, the role of oxidants in altering cellular tissue factor activity, and the roles of tissue factor pathway inhibitor and anti-thrombin Ill in inactivating the factor VIla/tissue factor complex. The third aim examines what factors determine the rate and amount of thrombin generated on activated platelets. These studies will examine mechanisms that limit thrombin generation on the platelet surface. The fourth aim examines how the amount of thrombin generated in the cell-based model correlates with formation of a stable hemostatic clot in vivo? These studies will examine fibrinogen structure and susceptibility to lysis as well as the role of thrombin activatable fibrinolysis inhibitor.