Arterial and venous endothelial cells are molecularly distinct from the
earliest stages of angiogenesis. This distinction is revealed by expression on
arterial 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 endothelial cells are necessary
for angiogenesis. This distinction can be used to advantage in methods to alter
angiogenesis, methods to assess the effect of drugs on artery cells and vein cells,
and methods to identify and isolate artery cells and vein cells, for example.
