FIBRINOGEN STRUCTURE, FUNCTION AND PHYSIOLOGY

成纤维细胞生长对血管内皮细胞的几个重要作用 包括增加扩散，刺激移民，上调调控 几种蛋白质的合成和刺激血管生成。内皮细胞 细胞特性也受到与纤维蛋白原相互作用的影响。和 纤维蛋白可以支持黏附，刺激蛋白质合成和 分泌，改变炎症细胞的相互作用和支持 血管生成。我们最近证明了成纤维细胞的生长 因子-2与纤维蛋白原和纤维蛋白特异结合， 与纤维蛋白原的相互作用增加了它的刺激能力 内皮细胞增殖。这些发现构成了以下研究的基础 建议进行的研究，其目的是界定 纤维蛋白原与成纤维细胞生长因子-2的相互作用及其特性 功能含义。第一个具体目标将是 成纤维细胞生长因子-2与特定实验的相互作用将确定 并确定成纤维细胞生长因子家族的其他成员 还能与纤维蛋白原结合。这种等离子体阻抗技术将被使用 测定缔合和解离速率常数以及 化学计量学定义了结合。初步实验表明 成纤维细胞生长因子-2与纤维蛋白原的结合提供了保护 蛋白质降解，这在延长作用时间中可能是重要的 在凝血酶和纤溶酶活跃的炎症部位。实验 在目标2中，将探索纤维蛋白原对成纤维细胞生长因子-2的保护程度 与纤维蛋白原的血浆衍生物结合，并在以下情况下保持活性 与这种衍生品捆绑在一起。目标3中的实验将延长 观察到成纤维细胞生长因子-2与纤维蛋白原的结合增强了其 刺激内皮细胞增殖的能力。参与其中的 已知的内皮细胞受体在这种活性的增强将 用特定的封闭的单抗、多肽来表征 和去整合素。形成成纤维细胞生长因子-2-纤维蛋白原复合体的必要性 在促进增殖方面将使用非成纤维细胞生长因子-2结合进行检测 成纤维细胞生长因子-2突变体的纤维蛋白原片段。这些将被用来确定 如果缺少结合纤维蛋白(原)能力的成纤维细胞生长因子-2突变体能够支持 纤维蛋白基质中的血管生成。进一步的实验将确定 纤维蛋白原也改变了成纤维细胞生长因子-2对内皮细胞迁移的影响 以及u-PA的合成。所获得的结果将提供信息 关于成纤维细胞生长因子-2和 纤维蛋白(原)对了解正常血管很重要 的发育和功能、对损伤的反应和疾病状况 哪些内皮细胞同时暴露于纤维蛋白(原)和成纤维细胞 增长因素。

Fibroblast growth exert several important effects of endothelial cells including increasing proliferation, stimulating migration, up-regulating synthesis of several proteins and stimulation angiogenesis. Endothelial cell properties are also influenced by interaction with fibrinogen. and fibrin which can support adhesion, stimulate protein synthesis and secretion, alter inflammatory cell interactions and support angiogenesis. We have recently demonstrated that fibroblast growth factor-2 (FGF-2) binds specifically to fibrinogen and fibrin, and that the interaction with fibrinogen increases its capacity to stimulate endothelial cell proliferation. These findings form the basis for the studies proposed which have a goal of defining the structural basis of the interaction between fibrin(ogen) and FGF-2 and characterizing its functional implications. The first specific aim will be to characterize the interaction between FGF-2 and specific experiments will identify the binding sites involved and determine if other members of the FGF family also bind to fibrinogen. Such plasmon resistance techniques will be used to determine the association and dissociation rate constants and stoichiometry defining the binding. Preliminary experiments indicate that the binding of FGF-2 to fibrinogen provides protection from proteolytic degradation, and this may be important in prolonging action at inflammatory sites where thrombin and plasmin are active. Experiments in Aim 2 will explore the extent to which fibrinogen protects FGF-2 binds to plasmic derivatives of fibrinogen and retains activity when bound to such derivatives. The experiments in Aim 3 will extend the observation that the binding of FGF-2 to fibrinogen potentiates its capacity to stimulate endothelial cell proliferation. The involvement of known endothelial cell receptors in this potentiation of activity will be characterized using specific blocking monoclonal antibodies, peptides and disintegrins. The need for formation for an FGF-2-fibrinogen complex in potentiating proliferation will be examined using non-FGF-2-binding fibrinogen fragments of FGF-2 mutants. These will be used to determine if FGF-2 mutants lacking the ability to bind fibrin(ogen) can support angiogenesis in a fibrin matrix. Further experiments will determine if fibrinogen also alters effects of FGF-2 on endothelial cell migration and synthesis of u-PA. The results obtained will provide information regarding fundamental aspects of the association of FGF-2 and fibrin(ogen) which will be important for understanding normal vascular development and function, response to injury, and disease conditions in which endothelial cells are exposed to both fibrin(ogen) and fibroblast growth factors.