HUMAN MICROVASCULAR ENDOTHELIAL-CELLS EXPRESS INTEGRIN-RELATED COMPLEXES THAT MEDIATE ADHESION TO THE EXTRACELLULAR-MATRIX
HUMAN MICROVASCULAR ENDOTHELIAL-CELLS EXPRESS INTEGRIN-RELATED COMPLEXES THAT MEDIATE ADHESION TO THE EXTRACELLULAR-MATRIX
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DOI：
10.1002/jcp.1041390209
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发表时间：
1989-05-01
影响因子：
5.6
通讯作者：
KRAMER, RH
中科院分区：
文献类型：
--
作者：
CHENG, YF;KRAMER, RH
Microvascular endothelial cells (MEC) must use a set of surface receptors to adhere not only to the vascular basement membrane but, during angiogenic stimulation, to the interstitum. We examined how cultured MEC isolated from human foreskin interact with their subendothelial matrix. MEC were able to attach to diverse extracellular matrix proteins, including fibronectin (Fn), vitronectin (Vn), laminin (Ln), type I and IV collagent, as well as to fibrinogen and gelatin. Adhesion to Fn, but not to laminin or collagens, was specifically blocked in the presence of Arg-Gly-Asp (RGD)-containing peptides. When surface radioiodinated MEC were solubilized and subjected to affinity chromatography on Fn-Sepharose columns, two polypeptides of 150 and 125 kD, corresponding to the integrin heterodimer .alpha.5.beta.1, were identified. MEC also express a complex of 150 (.alpha.) and 95 kD (.beta.3) that is related to the Vn receptor. Immunofluorescent staining of MEC cultures with antibodies to the integrin .beta.1 subunit demonstrated receptors on the basolateral surface a focal adhesion plaques that co-localized with vinculin and with Fn-positive matrix fibers. Occasionally, antibodies to the Vn receptor stained the vinculin-positive focal adhesion plaques that frequently co-localized with the .beta.1 complex. However, in cultures of MEC that were attached to substrates coated with alternating strips of Fn and Vn, the .beta.1 complex was preferentially localized to the Fn substrate, while the Vn receptor was concentrated on the Vn substrate. The results indicate that MEC express at least two different heterodimer adhesion receptors that belong to the integrin superfamily and appear to have distinct ligand specificities: the Fn receptor and the Vn receptor. These receptors mediate cell adhesion to the extracellular matrix and presumably have an important role in hemostatis and neovascularization.
