Role of aminopeptidase in angiogenesis.

Microvessels are composed of endothelial cells and surrounding pericytes. Angiogenesis, a neo-vessel formation from pre-existing microvessels, is a complex phenomenon, which requires following sequential steps: detachment of pre-existing pericytes for vascular destabilization, extracellular matrix turnover, migration, proliferation, tube formation by endothelial cells (ECs), and reattachment of pericytes for vascular stabilization. Aminopeptidases regulate the N-terminal modification of proteins and peptides for maturation, activation or degradation, and thereby relate to a variety of biological processes. Recently, three aminopeptidases have been reported to be involved in angiogenesis. They include type 2 methionine aminopeptidase, aminopeptidase N, and adipocyte-derived leucine aminopeptidase/puromycin insensitive leucyl-specific aminopeptidase. This review will focus on the possible role of these aminopeptidases in angiogenesis.