CXC chemokines in angiogenesis

A variety of factors have been identified that regulate angiogenesis, inclu ding the CXC chemokine family, The CXC chemokines are a unique family of cy tokines for their ability to behave in a disparate manner in the regulation of angiogenesis, CXC chemokines have four highly conserved cysteine amino acid residues, with the first two cysteine amino acid residues separated by one nonconserved amino acid residue (i.e., CXC). A second structural domai n within this family determines their angiogenic potential. The NH, terminu s of the majority of the CXC chemokines contains three amino acid residues (Glu-Leu-Arg: the ELR motif), which precedes the first cysteine amino acid residue of the primary structure of these cytokines. Members that contain t he ELR motif (ELR+) are potent promoters of angiogenesis. In contrast, memb ers that are inducible by interferons and lack the ELR motif (ELR-) are pot ent inhibitors of angiogenesis. This difference in angiogenic activity may impact on the pathogenesis of a variety of disorders.