Human microvascular endothelial cells use beta 1 and beta 3 integrin receptor complexes to attach to laminin.
Human microvascular endothelial cells use beta 1 and beta 3 integrin receptor complexes to attach to laminin.
复制标题
DOI：
10.1083/jcb.111.3.1233
复制
发表时间：
1990-09
期刊：
影响因子：
--
通讯作者：
Clyman R
中科院分区：
文献类型：
--
作者：
Kramer RH;Cheng YF;Clyman R
微血管内皮细胞（MEC）使用一组表面受体不仅粘附于血管基底膜，而且在血管生成刺激期间粘附于血管内皮细胞。我们研究了培养的人MEC如何与富含层粘连蛋白的基底膜相互作用。通过使用一组单克隆抗体，我们发现MEC细胞表达许多整合素相关受体复合物，包括α 1 β 1、α 2 β 1、α 3 β 1、α 5 β 1、α 6 β 1、α V β 3。对基底膜中主要粘附蛋白层粘连蛋白的粘附进行了详细研究。阻断特异于不同整合素受体复合物的单克隆抗体表明，α 6 β 1复合物对MEC粘附层粘连蛋白是重要的。此外，阻断抗体还涉及层粘连蛋白粘附中的玻连蛋白受体（α V β 3）。我们使用洗涤剂增溶受体复合物的配体亲和色谱法来进一步确定受体特异性。在层粘连蛋白-琼脂糖凝胶柱上，我们确定了几种整合素受体复合物，其对配体的亲和力取决于存在的二价阳离子的类型。几种β 1复合物，包括α 1 β 1、α 2 β 1和α 6 β 1，与层粘连蛋白强烈结合。与抗体阻断实验一致，发现α V β 3与层粘连蛋白结合良好。然而，与结合其其他配体（例如，玻连蛋白、纤维蛋白原、血管性血友病因子），α V β 3与层粘连蛋白的相互作用似乎不是Arg-Gly-Asp（RGD）敏感的。最后，免疫荧光染色表明，粘附层粘连蛋白包被的基板上的MEC的基底表面上的黏着斑蛋白阳性粘着斑中的β 1和β 3复合物。结果表明，这两个亚家族的整合素异源二聚体参与促进MEC粘附层粘连蛋白和血管基底膜。
Microvascular endothelial cells (MEC) use a set of surface receptors to adhere not only to the vascular basement membrane but, during angiogenic stimulation, to the interstitium. We examined how cultured human MEC interact with laminin-rich basement membranes. By using a panel of monoclonal antibodies, we found that MEC cells express a number of integrin-related receptor complexes, including alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha 6 beta 1, alpha V beta 3. Attachment to laminin, a major adhesive protein in basement membranes, was studied in detail. Blocking monoclonal antibodies specific to different integrin receptor complexes showed that the alpha 6 beta 1 complex was important for MEC adhesion to laminin. In addition, blocking antibody also implicated the vitronectin receptor (alpha V beta 3) in laminin adhesion. We used ligand affinity chromatography of detergent-solubilized receptor complexes to further define receptor specificity. On laminin-Sepharose columns, we identified several integrin receptor complexes whose affinity for the ligand was dependent on the type of divalent cation present. Several beta 1 complexes, including alpha 1 beta 1, alpha 2 beta 1, and alpha 6 beta 1 bound strongly to laminin. In agreement with the antibody blocking experiments, alpha V beta 3 was found to bind well to laminin. However, unlike binding to its other ligands (e.g., vitronectin, fibrinogen, von Willebrand factor), alpha V beta 3 interaction with laminin did not appear to be Arg-Gly-Asp (RGD) sensitive. Finally, immunofluorescent staining demonstrated both beta 1 and beta 3 complexes in vinculin-positive focal adhesion plaques on the basal surface of MEC adhering to laminin-coated substrates. The results indicate that both these subfamilies of integrin heterodimers are involved in promoting MEC adhesion to laminin and the vascular basement membrane.