Proteomic Analysis of Plasminogen Receptors

描述（由申请方提供）：纤溶酶原和纤溶酶原激活剂在细胞表面上的组装是细胞表面蛋白水解活性正调控的关键控制点，这在需要细胞迁移的生理和病理过程中是必需的。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。该提议是基于证明纤溶酶原结合功能的上调发生在活的单核细胞分化成活的巨噬细胞期间的数据。在初步研究中，我们确定了三个主要的候选人纤溶酶原受体上调响应M-CSF尚未被公认为以前的单核细胞上的纤溶酶原结合位点。本申请的目的是阐明M-CSF上调的纤溶酶原受体在单核细胞/巨噬细胞募集中的作用。要解决的中心假设是，纤溶酶原受体在单核细胞/巨噬细胞成熟过程中上调，并通过促进纤溶酶原活化和将纤溶酶的蛋白水解活性定位在细胞表面上，促进这些细胞响应炎症刺激的募集。为了检验这一假设，我们将I）鉴定M-CSF刺激的细胞上的主要促纤溶纤溶酶原结合蛋白，并在体内单核细胞发育期间定量其表达，和II）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活化、细胞外基质降解和细胞迁移的假设。我们期望我们特定目标的实现将提供适用于炎症调节的基本见解。此外，由于单核/巨噬细胞的募集和浸润是动脉粥样硬化病变的一个关键特征，我们的研究结果应适用于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.