EMA-1, a Novel Endothelial Cell Surface Molecule That is Preferentially Expressed by Migrating Endothelial Cells

Abstract

The vascular endothelium forms a continuous sheet of squamous epithelium that lines the inside of all vessels. Extending throughout the body, it is a tissue with considerable biological potential. Many of the complex functions of endothelial cells appear to involve specific structural and chemical domains of the lumenal cell surface.^9,10 Structural differences characterized by the formation of continuous, fenestrated and discontinuous endothelia serve the need for different transendothelial perfusion rates in various organs, while the biochemical heterogeneity of endothelial cells is closely linked to their role in inflammation, immunity, and neoplasia. Constitutively expressed and inducible endothelial cell surface molecules have been identified that play critical roles in the regulation of lymphocyte and leukocyte trafficking, and in the metastatic colonization of select organ sites.^10,14 Distinct biochemical cell surface properties have recently been associated with the migratory phenotype of endothelial cells.¹ The lumenal surface of migrating endothelial cells expresses a distinct pattern of hyperglycosylation and specific migration-associated cell surface molecules. These findings suggested that endothelial cells express a distinct phenotype during angiogenesis and/or reendothelialization.