title: Differential chemokine receptor expression regulates functional specialization of endothelial progenitor cell subpopulations.
abstract: Postnatal vasculogenesis is mediated by endothelial progenitor cells (EPCs) which consist of subpopulations with different functional capacities. Our goal was to profile chemokine receptor expression on relevant subsets of EPCs and to characterize their role for effector functions. CD34(+)/CD133(+)/VEGFR2(+) EPCs were characterized by high expression of chemokine receptors CXCR4, CX3CR1, BLT1, and low level expression of CXCR2 and CCR2, while primordial CD34(-)/CD133(+)/VEGFR2(+) EPCs express these chemokine receptors at comparably low levels. Migration assays revealed that SDF-1, fractalkine, and LTB4 significantly increase migration of CD34(-)/CD133(+)/VEGFR2(+) EPCs, while SDF-1 was the only potent agonist of migration of CD34(+)/CD133(+)/VEGFR2(+) EPCs. SDF-1, fractalkine, and LTB4 trigger significant increase adhesion of CD34(+)/CD133(+)/VEGFR2(+) EPCs, while in CD34(-)/CD133(+)/VEGFR2(+) EPCs SDF-1 and fractalkine are equipotent agonists and LTB4 triggers a smaller though still significant increase in adhesion. Differential expression of specific chemokine receptors is an important regulator in terms of migration and adhesion of biologically relevant EPC-subpopulations, which may have implications for cell therapeutic strategies for treatment of ischemic vascular disease.
authors.affiliation: Klinik für Innere Medizin III (Kardiologie, Angiologie, Internistische Intensivmedizin), Universitätsklinikum des Saarlandes, 66421 Homburg/Saar, Germany. kwalent@hotmail.de
authors.forename: Katrin L H
authors.initials: KL
authors.lastname: Walenta
authors.forename: Stephanie
authors.initials: S
authors.lastname: Bettink
authors.forename: Michael
authors.initials: M
authors.lastname: Böhm
authors.forename: Erik B
authors.initials: EB
authors.lastname: Friedrich
mesh_terms: D000328:Adult; D053687:Adult Stem Cells / Q000378:metabolism*; D002448:Cell Adhesion; D002465:Cell Movement; D018932:Chemokine CCL2 / Q000378:metabolism; D054428:Chemokine CX3CL1 / Q000378:metabolism; D054377:Chemokine CXCL12 / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007975:Leukotriene B4 / Q000378:metabolism; D008297:Male; D019707:Receptors, Chemokine / Q000378:metabolism*
chemical_list: C111835:CCL2 protein, human; C515255:CXCL12 protein, human; D018932:Chemokine CCL2; D054428:Chemokine CX3CL1; D054377:Chemokine CXCL12; D016209:Interleukin-8; D019707:Receptors, Chemokine; D007975:Leukotriene B4