Characterization of glomerular epithelial cell matrix receptors.
Characterization of glomerular epithelial cell matrix receptors.
复制标题
DOI：
--
复制
发表时间：
1992-09
期刊：
影响因子：
--
通讯作者：
S. Adler
中科院分区：
文献类型：
--
作者：
S. Adler
肾小球上皮细胞（glomerular epithelial cells， GEC）上的整合素基质受体可能在GEC粘附到肾小球基底膜（glomerular basal membrane， GBM）和维持正常肾小球通透性中发挥重要作用。因此，作者确定了培养大鼠GEC中存在的基质受体的类型，并检查了它们与细胞外基质的几种成分的相互作用。体内大鼠肾三种肾小球细胞均检测到β 1整合素基质受体，并在培养的GEC细胞接触区域检测到β 1整合素基质受体。肾小球上皮细胞对I型和IV型胶原的粘附略大于对层粘连蛋白和纤维连接蛋白的粘附。含有RGD粘附序列的合成肽可显著抑制对纤维连接蛋白的粘附。表面碘化GEC裂解物的免疫沉淀显示存在α 3 β 1整合素。固定化胶原裂解物的层析显示，α 3 β 1整合素和70- 75-kd蛋白带是GEC上的胶原受体。对120-kd的纤维连接蛋白细胞结合片段进行色谱分析，发现只有α 3 β 1是特异性的纤维连接蛋白受体。1整合素链抗体抑制层粘连蛋白和胶原的粘附。这些研究表明，在体外和体内，GEC似乎只表达α 3 β 1整合素。此外，该基质受体能够介导GEC与胶原、纤维连接蛋白和层粘连蛋白（GBM的成分）的粘附，并且可能在体内促进GEC与GBM的粘附中发挥类似的作用。
Integrin matrix receptors on glomerular epithelial cells (GEC) may play an important role in adhesion of GEC to the glomerular basement membrane (GBM) and in the maintenance of normal glomerular permeability. Therefore, the author determined the types of matrix receptors present on cultured rat GEC and examined their interactions with several components of the extracellular matrix. Beta 1 integrin matrix receptors were detected on all three glomerular cell types in rat kidney in vivo and at areas of cell-cell contact on cultured GEC. Glomerular epithelial cell adhesion to types I and IV collagen was slightly greater than to laminin and fibronectin. Adhesion to fibronectin was significantly inhibited by a synthetic peptide containing the RGD adhesion sequence. Immunoprecipitation of lysates of surface-iodinated GEC showed the presence of alpha 3 beta 1 integrin. Chromatography of lysates on immobilized collagen showed alpha 3 beta 1 integrin and a 70- to 75-kd protein band as the collagen receptors on GEC. Chromatography on the 120-kd cell-binding fragment of fibronectin disclosed only alpha 3 beta 1 as a specific fibronectin receptor. Antibody to the beta 1 integrin chain inhibited adhesion to laminin and collagen. These studies demonstrate that in vitro, as in vivo, GEC appear to express only alpha 3 beta 1 integrin. Furthermore, this matrix receptor is capable of mediating GEC adhesion to collagen, fibronectin, and laminin, components of the GBM, and presumably plays a similar role in promoting GEC adhesion to GBM in vivo.