The soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) is a polypeptide secreted by endothelial cells that contains six out of the seven extracellular Ig-like domains of the transmembrane VEGFR-1 and a unique sequence of 30 amino acids. The biological role of sVEGFR-1 has not been clarified yet, even though it is considered a negative modulator of VEGF and PlGF activity, blocking the interaction of these growth factors with their membrane receptors. We have recently demonstrated that endothelial cells adhere on sVEGFR-1 and migrate in response to the polypeptide through a mechanism that involves the integrin alpha5beta1. Moreover, endothelial cells deposit the sVEGFR-1 into the extracellular matrix. These data suggest a role for sVEGFR-1 in processes of primary importance during angiogenesis, such as migration and interaction of endothelial cells with the extracellular matrix. To test this hypothesis, we designed a series of VEGFR-1 peptides, potentially able to block the sVEGFR-1/alpha5beta1 integrin interaction. Based on the structural analysis of VEGFR-1 second Ig-like domain, a set of eight peptides was synthesised. Peptides were tested for the ability to inhibit endothelial cell adhesion on sVEGFR-1 or fibronectin. Peptide A4 reduced cell adhesion on sVEGFR-1 and fibronectin by 50% and 30%, respectively. We next evaluated the effects of peptide A4 on endothelial cell migration induced by fibronectin, sVEGFR-1, VEGF or PlGF. Treatment with peptide A4 resulted in 30% inhibition of basal migration (without stimulus) and abrogation of the response to either sVEGFR-1 or PlGF, whereas it did not affect migration induced by fibronectin or VEGF. A control peptide, containing the amino acids of peptide A4 in a scrambled sequence, did not have any effect on endothelial cell migration. To further define the region of peptide A4 responsible of its inhibitory activity, a second set of peptides corresponding to a part of peptide A4 sequence was tested. Peptide B3 resulted to be the most efficient in inhibiting endothelial cell migration. In conclusion, peptide B3 behaves as a selective inhibitor of endothelial cell migration induced by sVEGFR-1 or PlGF. As cell migration is a fundamental step in the process of angiogenesis, peptide B3 could represent a leading molecule for the design of new drugs to be used in the treatment of cancer or other angiogenesis-related diseases. Supported by the Italian Ministry of Health and Compagnia di San Paolo.
Lacal, P., Ruffini, F., Orecchia, A., Failla, C., Morea Soro, S., Vergati, M., et al. (2005). Inhibition of endothelial cell migration by vascular endothelial growth factor receptor-1 peptides.. In Proceedings of the 5th ESH Interdisciplinary Euroconference on Angiogenesis, Sitges, Spain.
Inhibition of endothelial cell migration by vascular endothelial growth factor receptor-1 peptides.
TENTORI, LUCIO;GRAZIANI, GRAZIA;
2005-01-01
Abstract
The soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) is a polypeptide secreted by endothelial cells that contains six out of the seven extracellular Ig-like domains of the transmembrane VEGFR-1 and a unique sequence of 30 amino acids. The biological role of sVEGFR-1 has not been clarified yet, even though it is considered a negative modulator of VEGF and PlGF activity, blocking the interaction of these growth factors with their membrane receptors. We have recently demonstrated that endothelial cells adhere on sVEGFR-1 and migrate in response to the polypeptide through a mechanism that involves the integrin alpha5beta1. Moreover, endothelial cells deposit the sVEGFR-1 into the extracellular matrix. These data suggest a role for sVEGFR-1 in processes of primary importance during angiogenesis, such as migration and interaction of endothelial cells with the extracellular matrix. To test this hypothesis, we designed a series of VEGFR-1 peptides, potentially able to block the sVEGFR-1/alpha5beta1 integrin interaction. Based on the structural analysis of VEGFR-1 second Ig-like domain, a set of eight peptides was synthesised. Peptides were tested for the ability to inhibit endothelial cell adhesion on sVEGFR-1 or fibronectin. Peptide A4 reduced cell adhesion on sVEGFR-1 and fibronectin by 50% and 30%, respectively. We next evaluated the effects of peptide A4 on endothelial cell migration induced by fibronectin, sVEGFR-1, VEGF or PlGF. Treatment with peptide A4 resulted in 30% inhibition of basal migration (without stimulus) and abrogation of the response to either sVEGFR-1 or PlGF, whereas it did not affect migration induced by fibronectin or VEGF. A control peptide, containing the amino acids of peptide A4 in a scrambled sequence, did not have any effect on endothelial cell migration. To further define the region of peptide A4 responsible of its inhibitory activity, a second set of peptides corresponding to a part of peptide A4 sequence was tested. Peptide B3 resulted to be the most efficient in inhibiting endothelial cell migration. In conclusion, peptide B3 behaves as a selective inhibitor of endothelial cell migration induced by sVEGFR-1 or PlGF. As cell migration is a fundamental step in the process of angiogenesis, peptide B3 could represent a leading molecule for the design of new drugs to be used in the treatment of cancer or other angiogenesis-related diseases. Supported by the Italian Ministry of Health and Compagnia di San Paolo.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
