Migrating vascular smooth muscle cells polarize cell surface urokinase receptors after injury in vitro.
Migrating vascular smooth muscle cells polarize cell surface urokinase receptors after injury in vitro.
复制标题
体外损伤后，迁移的血管平滑肌细胞使细胞表面尿激酶受体极化。
DOI：
10.1006/excr.1995.1077
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发表时间：
1995
影响因子：
3.7
通讯作者：
Barnathan,ES
中科院分区：
文献类型：
--
作者：
Okada,SS;Tomaszewski,JE;Barnathan,ES
蛋白酶通过受体定位于细胞表面可以促进细胞迁移、侵袭和基质降解。由于血管平滑肌细胞（SMC）迁移可能是动脉粥样硬化和血管损伤后内膜增厚的重要事件，我们研究了培养的人血管SMC中尿激酶型纤溶酶原激活物（u-PAR）受体的细胞表面表达。使用免疫荧光显微镜，我们证明了几种染色模式的SMC u-PAR：在细胞膜的周边，在前缘，并在细胞-细胞接触部位。当使用伤口测定进行迁移实验时，伤口边缘处三分之一的SMC显示细胞表面u-PAR朝向细胞膜的前缘极化（32 ± 2%，± SEM，n = 7）。用小窝蛋白（一种在小窝中发现的跨膜蛋白）的抗体观察到类似的模式，但用5′-核苷酸酶（另一种细胞表面糖磷脂酰肌醇锚定蛋白，在细胞表面均匀表达）的抗体则没有。低密度脂蛋白受体相关蛋白，介导的u-PAR结合配体的内化，分布在一个弥漫性点状图案，不极化的前沿。双重免疫荧光研究表明，SMC u-PAR与黏着斑蛋白和小窝蛋白在伤口试验的前沿迁移SMC中共分布。极化的细胞表面的a-PAR没有观察到无论是非创伤或subconfluent文化，尽管随机迁移行为。这些研究表明，在响应创伤，人血管平滑肌细胞增殖和浓缩细胞表面u-PAR的前沿，也许有利于定向迁移。
The localization of proteases to cell surfaces via receptors may facilitate cell migration, invasion, and matrix degradation. Since vascular smooth muscle cell (SMC) migration may be an important event in atherosclerosis and in intimal thickening after vascular injury, we studied the cell surface expression of a receptor for urokinase-type plasminogen activator (u-PAR) in cultured human vascular SMC. Using immunofluorescence microscopy, we demonstrated several staining patterns of SMC u-PAR: at the periphery of the cell membrane, at the leading edge, and at cell-cell contact sites. When migration experiments were performed using a wound assay, one-third of the SMC at the wound edge demonstrated polarization of cell surface u-PAR toward the leading edge of the cell membrane (32 ± 2%, ± SEM, n = 7). A similar pattern was seen with an antibody to caveolin, a transmembrane protein found in caveolae, but not with an antibody to 5′-nucleotidase, another cell surface glycophosphatidylinositol-anchored protein, which was homogeneously expressed on the cell surface. Low-density lipoprotein receptor-related protein, which mediates internalization of u-PAR bound ligands, was distributed in a diffuse punctate pattern, not polarized to the leading edge. Double immunofluorescent studies demonstrated codistribution of SMC u-PAR with vinculin and caveolin in migrating SMC at the leading edge in a wound assay. Polarization of cell surface a-PAR was not observed in either non-wounded or subconfluent cultures, despite random migratory behavior. These studies suggest that in response to wounding, human vascular SMC polarize and concentrate cell surface u-PAR to their leading edge, perhaps facilitating directional migration.