Proteomic Analysis of Plasminogen Receptors

描述(申请人提供)：纤溶酶原和纤溶酶原激活剂在细胞表面的组装是积极调节细胞表面蛋白分解活性的关键控制点，在需要细胞迁移的生理和病理过程中都是必需的。我们实验室的长期目标是了解纤溶酶原与细胞结合的调节机制，以便在生理和病理过程中发挥作用。这一建议基于的数据表明，纤溶酶原结合功能的上调发生在活性单核细胞向活性巨噬细胞分化的过程中。在初步研究中，我们确定了三个主要的候选纤溶酶原受体，它们是单核细胞上的纤溶酶原结合部位，对M-CSF的反应是上调的。这项应用的目的是阐明M-CSF上调的纤溶酶原受体在单核/巨噬细胞募集中的作用。需要解决的中心假设是，纤溶酶原受体在单核/巨噬细胞成熟过程中上调，并通过促进纤溶酶原激活和定位纤溶酶在细胞表面的蛋白分解活性，促进这些细胞对炎症刺激的招募。为了验证这一假说，我们将1)鉴定M-CSF刺激的细胞上的主要纤溶酶原结合蛋白，并量化它们在体内单核细胞发育过程中的表达；2)检验M-CSF上调的纤溶酶原受体在体外和体内促进纤溶酶原激活、细胞外基质降解和细胞迁移的假说。我们预计，我们特定目标的实现将提供适用于炎症调控的基本见解。此外，由于单核/巨噬细胞聚集和渗透是动脉粥样硬化病变的一个关键特征，我们的结果应该应用于对动脉粥样硬化的理解。

DESCRIPTION (provided by applicant): The assembly of plasminogen and plasminogen activators on cell surfaces is a crucial control point for positive regulation of cell surface proteolytic activity necessary in both physiological and pathological processes requiring cell migration. The long-term goal of our laboratory is to understand the mechanisms by which plasminogen binding to cells is regulated, in order to function in physiological and pathological processes. This proposal is based on data demonstrating that up-regulation of plasminogen binding function occurs during differentiation of viable monocytes into viable macrophages. In preliminary studies, we identified three major candidate plasminogen receptors up-regulated in response to M-CSF that have not been recognized previously as plasminogen binding sites on monocytes. The objective of this application is to elucidate the role of M-CSF-up-regulated plasminogen receptors in monocyte/macrophage recruitment. The central hypothesis to be addressed is that plasminogen receptors are up-regulated during monocyte/macrophage maturation and facilitate recruitment of these cells in response to inflammatory stimuli, by promoting plasminogen activation and localizing the proteolytic activity of plasmin on the cell surface. To test this hypothesis we will I) identify the major pro- fibrinolytic plasminogen binding proteins on M-CSF-stimulated cells and quantify their expression during monocyte development in vivo and II) test the hypothesis that M-CSF-up-regulated plasminogen receptors promote plasminogen activation, extracellular matrix degradation and cell migration in vitro and in vivo. We expect that accomplishment of our specific aims will provide fundamental insights that will apply to the regulation of inflammation. Furthermore, because monocyte/macrophage recruitment and infiltration is a key feature of the atherosclerotic lesion, our results should apply to the understanding of atherosclerosis.