MMP-2 colocalizes with caveolae on the surface of endothelial cells
MMP-2 colocalizes with caveolae on the surface of endothelial cells
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DOI：
10.1006/excr.2000.5069
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发表时间：
2001-01-01
影响因子：
3.7
通讯作者：
Menashi, S
中科院分区：
文献类型：
--
作者：
Puyraimond, A;Fridman, R;Menashi, S
我们使用免疫荧光和共聚焦显微镜检查了人内皮细胞表面 MMP-2 的空间分布。用 MMP-2 特异性抗体对内皮细胞进行染色，发现细胞外周基底外侧有点状标记，该标记与小窝的主要成分 Caveolin-1 斑块共定位。通过免疫金电子显微镜证实了这种共定位。 MT1-MMP、TIMP-2 和 alphav beta3 整合素表现出相似的染色模式，细胞周斑块与 MMP-2 或 Caveolin-1 共定位。仅在用刀豆球蛋白 A 处理后才能在小凹斑块中看到 MT1-MMP 和 TIMP-2 的存在，刀豆球蛋白 A 诱导 MMP-2 激活，但对 MMP-2 免疫染色的模式或强度没有明显影响。相反，MMP-9和TIMP-1染色显示与MMP-2和TIMP-2完全不同的模式，阳性斑点均匀分布在整个细胞体中。我们的数据表明，MMP-2、其激活剂 MT1-MMP 及其拟议受体 αv beta3 整联蛋白均靶向内皮细胞上的相同膜微结构域，从而将基质蛋白水解限制在细胞表面的有限微环境中。 (C) 2001 年学术出版社。
We examined the spatial distribution of MMP-2 on the surface of human endothelial cells using immunofluorescence and confocal microscopy. Staining endothelial cells with MMP-2-specific antibodies revealed a punctate labeling at the basolateral side of the cell periphery, which colocalized with patches of caveolin-1, a major constituent of the caveolae. This colocalization was confirmed by immunogold electron microscopy. MT1-MMP, TIMP-2, and the alphav beta3 integrin exhibited a similar pattern of staining, with pericellular patches that colocalized with either MMP-2 or caveolin-1. The presence of MT1-MMP and TIMP-2 in caveolae patches could be seen only after treatment with concanavalin A, which induced MMP-2 activation but had no noticeable effect on the pattern or intensity of MMP-2 immunostaining. In contrast, MMP-9 and TIMP-1 staining showed a pattern completely different from that of MMP-2 and TIMP-2, with positive spots uniformly distributed throughout the cell body. Our data show that MMP-2, its activator the MT1-MMP, and its proposed receptor, the alphav beta3 integrin, are all targeted to the same membrane microdomains on the endothelial cell, thereby restricting matrix proteolysis to a Limited microenvironment at the cell surface. (C) 2001 Academic Press.