Arterial and venous
smooth muscle cells are molecularly distinct from the earliest stages of
angiogenesis through to adulthood. This distinction is revealed by expression on arterial cells (e.g., arterial endothelial cells, arterial
smooth muscle cells) of a transmembrane ligand, called EphrinB2 whose
receptor EphB4 is expressed on venous cells.
Targeted disruption of the EphrinB2
gene prevents the remodeling of veins from a capillary
plexus into properly branched structures. Moreover, it also disrupts the remodeling of arteries, suggesting that reciprocal interactions between pre-specified arterial and venous cells are necessary for
angiogenesis. Expression of EphrinB2 in arterial cells (e.g., arterial endothelial cells, arterial
smooth muscle cells) can be used to
advantage in methods for targeting agents and / or encoded polypeptides to arterial smooth
muscle cells, altering
angiogenesis, assessing the effect of agents on arterial smooth
muscle cells, identifying arterial smooth
muscle cells, isolating arterial smooth muscle cells and production of artificial vessels, for example.