HARP induces angiogenesis in vivo and in vitro: Implication of N or C terminal peptides

HARP (heparin affin regulatory peptide) is a growth factor displaying high affinity for heparin, In the present work, we studied the ability of human recombinant HARP as well as its two terminal peptides (HARP residues 1-21 a nd residues 121-139) to promote angiogenesis. HARP stimulates endothelial c ell tube formation on matrigel, collagen and fibrin gels, stimulates endoth elial cell migration and induces angiogenesis in the in vivo chicken embryo chorioallantoic membrane assay. The two HARP peptides seem to be involved in most of the angiogenic effects of HARP. They both stimulate in vivo angi ogenesis and in vitro endothelial cell migration and tube formation on matr igel, We conclude that HARP has an angiogenic activity when applied exogeno usly in several in vitro and in vivo models of angiogenesis and its NH2 and COOH termini seem to play an important role. (C) zool Academic Press.