FIBRONECTIN AND CELL RECRUITMENT

纤维连接蛋白是一种由成纤维细胞产生的44万道尔顿糖蛋白， 单核细胞、上皮细胞和内皮细胞在人血浆中循环 在300 g/ml的浓度下；激活时与纤维蛋白结合 凝血系统；并沉积在炎症和伤口处 治愈。这些部位的纤维连接蛋白沉积都是由血浆引起的。 和细胞来源，并与增殖，迁移和 定位细胞群，包括单核/巨噬细胞、内皮细胞 细胞、表皮细胞和成纤维细胞。体外血浆或细胞 纤维连接蛋白可以结合到胶原或纤维蛋白原的基质上，并且 同时与成纤维细胞结合。这些数据综合在一起是最令人难以置信的 纤维连接蛋白可能在细胞和细胞之间提供了关键的联系。 底物，尤其是在组织重塑期间。我们建议对此进行测试 通过研究血浆和细胞纤维连接蛋白或 纤维连接蛋白片段影响正常的人细胞黏附和趋化 体外和体内细胞定位。我们已经开发了定量的， 用于研究人体细胞黏附的可重复性分析以确定 正常的人体细胞可以利用纤维连接蛋白进行附着 并研究对纤维连接蛋白的需求是否相同 在各种人类细胞类型中。要解决后一个问题，需要多个 依从性分析中的参数将变化以描绘时间进程 对于粘附性、粘附性、最适量的纤维连接蛋白 每种细胞类型的贴壁和其他最佳贴壁条件(目的 1)。我们还将研究表皮细胞在成纤维细胞上的黏附和 表皮细胞衍生底物(目标1)。因为我们已经 证明纤维连接蛋白促进单核细胞和表皮细胞 坚持，我们将通过以下方式调查发生这种情况的机制 改变蛋白质(目标2)和修饰细胞(目标3)。此外, 我们将调查纤维连接蛋白或纤维连接蛋白片段是否会招募 细胞黏附以外的其他方式。具体地说，我们已经证明了 120K和210K纤维连接蛋白片段刺激单核细胞趋化和 将研究趋化纤维连接蛋白的可能机制(S) 片段可以在体内产生，并将定义限制肽 趋化活性所必需的序列(目标4)。此外，我们还将 测定纤维连接蛋白和其他ECM蛋白对表皮的影响 细胞运动(目标5)。最后，我们将调查纤维连接蛋白或 纤维连接蛋白片段在体内招募细胞(目标6)。我们的最终目标是 了解纤维连接蛋白在伤口愈合中的作用。

Fibronectin, a 440,000 dalton glycoprotein produce by fibroblasts, monocytes, and epithelial and endothelial cells, circulates in human plasma at concentrations of 300 g/ml; associates with fibrin upon activation of the clotting system; and is deposited at sites of inflammation and wound healing. The fibronectin deposition in these sites is both plasma-derived and cell-derived and is associated with proliferating migrating and localizing cell populations including monocyte/macrophage, endothelial cells, epidermal cells and fibroblasts. In vitro plasma or cellular fibronectin can bind to a substratum of collagen or fibrinogen and simultaneously bind to fibroblasts. These data taken together suggeest that fibronectin may provide a critical link between cells and their substrata especially during tissue remodeling. We propose to test this hypothesis by investigating how plasma and cellular fibronectin or fibronectin fragments affect normal human cell adherence and chemotaxis in vitro and cell localization in vivo. We have developed quantitative, reproducible assays for study of human cell adherence to determine whether normal human cells can utilize fibronectin for their attachment as do cell-lines and to study whether the requirement for fibronectin is the same among the various human cell types. To address the latter issue multiple parameters in the adherence assays will be varied to delineate time course for adherence, tenacity of adherence, optimal amounts of fibronectin for adherence and other optimal conditions for adherence of each cell type (Aim 1). We will also study epidermal cell adherence on fibroblast and epidermal cell derived substrates (Aim 1). Since we have already demonstrated that fibronectin enhances monocyte, and epidermal cell adherence, we will investigate mechanisms by which this may occur by altering the protein (Aim 2) and modifying the cell (Aim 3). In addition, we will investigate whether fibronectin or fibronectin fragments recruit cells by means other than cell adherence. Specifically, we have shown that the 120K and 210K fibronectin fragments stimulate monocyte chemotaxis and will study possible mechanism(s) by which chemoattractive fibronectin fragments may be generated in vivo and will define the limiting peptide sequence necessary for chemotactic activity (Aim 4). In addition, we will determine the effect of fibronectin and other ECM proteins on epidermal cell motility (Aim 5). Finally, we will investigate whether fibronectin or fibronectin fragments recruit cells in vivo (Aim 6). Our ultimate goal is to understand the role of fibronectin in wound healing.