Endothelial cell adhesive receptors.

Endothelial cells express a variety of adhesive receptors that regulate their adhesion to extracellular matrix and organization of cell-cell junctions. Most of the endothelial cell receptors for matrix proteins, characterized so far, belong to the integrin superfamily. Endothelial cells, as many other cell types, have many different integrins on their surface. This indicates that the interaction with matrix proteins is a complex phenomenon that requires multiple (and possibly redundant) recognition mechanisms. We have only a limited knowledge of the structures involved in endothelial cell-cell junctions. Integrins have been found to be localized in these structures too. This suggests that they can play a role also in this homotypic type of cell interaction. Other molecules, however, that are structurally and functionally distinct from integrins have been found in endothelial cell-to-cell contacts. The reciprocal role of these proteins remains to be fully defined.