Angiogenesis - the formation of capillaries from pre-existing microvessels - is important in many normal and pathological processes, including embryogenesis and tumour development. On , Georges Bellon and colleagues report that elastin-derived peptides (EDPs) enhance angiogenesis through upregulation of membrane-type metalloproteinase 1 (MT1-MMP). EDPs are involved in many biological activities, their cellular effects being mediated through binding of a VGVAPG hexapeptide sequence to elastin-binding protein, a lectin-like receptor. The authors show that VGVAPG-motif-containing EDPs accelerate tubulogenesis in in vivo and in vitro models of angiogenesis and stimulate cell migration in a wound-healing assay. Furthermore, EDPs upregulate proMT1-MMP and proMMP-2 expression and activation, and EDP-mediated angiogenesis is triggered through elastin-binding protein. Then, by using small interfering RNAs specific for MT1-MMP, the authors reveal a crucial role for MT1-MMP in EDP-mediated angiogenesis. They conclude that EDPs, by upregulating MT1-MMP expression in endothelial cells, are important in processes in which matrix pericellular proteolysis, MT1-MMP endocytosis, MMP proteolytic activation cascades and/or cell surface receptor shedding are required for angiogenesis.
