Angiogenic activity of syndecan-binding laminin peptide AG73 (RKRLQVQLSIRT).

The AG73 peptide (RKRLQVQLSIRT, mouse laminin alpha 1 chain 2719-2730) promotes cell adhesion and tumor metastasis, and interacts with transmembrane syndecan proteoglycans. Here, we demonstrate AG73 peptide angiogenic activity using in vitro, ex vivo, and in vivo models. AG73 induced murine endothelial cell (SVEC4-10) tube formation on Cultrex Basement Membrane Extract (Cultrex BME) and stimulated sprouting of aortic rings. None of the homologous sequences from the laminin alpha2, alpha3, alpha4, or alpha5 chains was as active as AG73 in promoting sprouting formation. AG73 also mediated angiogenesis in the chick chorioallantonic membrane (CAM) assay. Using subcutaneously injected Cultrex BME supplemented with AG73, we observed a large angiogenic response. Furthermore, AG73-conjugated to a chitosan membrane promoted a strong angiogenic response in the CAM assay. These results indicate that the AG73 peptide is a potent syndecan-binding angiogenesis stimulator and may be useful for therapeutic application to treat ischemic injuries.