title: Increased VEGFR2 expression during human late endothelial progenitor cells expansion enhances in vitro angiogenesis with up-regulation of integrin alpha(6).
abstract: In vitro expansion of late endothelial progenitor cells (EPCs) might yield a cell therapy product useful for myocardial and leg ischaemia, but the influence of EPC expansion on the angiogenic properties of these cells is unknown. In the present study, we investigated the effect of in vitro EPC expansion on vascular endothelial growth factor (VEGF) receptor expression. EPCs were obtained from CD34(+) cord blood cells and expanded for up to 5 weeks. Real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) showed that VEGFR2 expression, contrary to VEGFR1 and VEGFR3 expression, was significantly higher on expanded EPCs than on freshly isolated CD34(+) cells or on human umbilical vein endothelial cells (HUVECs). Quantitative flow cytometry confirmed that VEGFR2 density on EPCs increased during the expansion process and was significantly higher than on HUVECs. The impact of VEGFR2 increase was studied on the three theoretical steps of angiogenesis, i.e., EPC proliferation, migration and differentiation. VEGFR2 up-regulation had no effect on VEGF-induced cell proliferation, but significantly enhanced EPC migration and pseudotubes formation dependent on integrin alpha(6) subunit overexpression. In vitro expansion of late EPCs increases the expression of VEGFR2, the main VEGF receptor, with possible implications for EPC-based angiogenic therapy.
authors.affiliation: AP-HP, Service d'Hématologie Biologique A, Hôpital Européen Georges Pompidou, Paris, France.
authors.forename: David M
authors.initials: DM
authors.lastname: Smadja
authors.forename: Ivan
authors.initials: I
authors.lastname: Bièche
authors.forename: Dominique
authors.initials: D
authors.lastname: Helley
authors.forename: Ingrid
authors.initials: I
authors.lastname: Laurendeau
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Simonin
authors.forename: Laurent
authors.initials: L
authors.lastname: Muller
authors.forename: Martine
authors.initials: M
authors.lastname: Aiach
authors.forename: Pascale
authors.initials: P
authors.lastname: Gaussem
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D039503:Integrin alpha6 / Q000235:genetics*; D007797:Laminin / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics* / Q000378:metabolism; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000235:genetics / Q000378:metabolism
chemical_list: D004338:Drug Combinations; D039503:Integrin alpha6; D007797:Laminin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011509:Proteoglycans; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C059485:matrigel; D003094:Collagen; D040301:Vascular Endothelial Growth Factor Receptor-2; D040321:Vascular Endothelial Growth Factor Receptor-3