[Endothelial cell-cell junctions in vessel formation]

The endothelium, lining the inner side of all vessel types, is constituted of a monolayer of endothelial cells with cobblestone morphology. Endothelial cell-cell contacts contain numerous transmembrane adhesive proteins that are either clustered in junctional structures or located along the intercellular cleft. These proteins promote cell-cell adhesion and control vascular permeability to fluids and molecules, as well as transmigration of various types of leukocytes. In addition, recent findings showed that constituents of the junctions might be part of the vascular invasion machinery by activating cell protrusions. Such activities may thus be considered as markers of pathological angiogenesis or targets of antiangiogenic therapy.