title: Hematopoietic stem cell cytokines and fibroblast growth factor-2 stimulate human endothelial cell-pericyte tube co-assembly in 3D fibrin matrices under serum-free defined conditions.
abstract: We describe a novel 3D fibrin matrix model using recombinant hematopoietic stem cell cytokines under serum-free defined conditions which promotes the assembly of human endothelial cell (EC) tubes with co-associated pericytes. Individual ECs and pericytes are randomly mixed together and EC tubes form that is accompanied by pericyte recruitment to the EC tube abluminal surface over a 3-5 day period. These morphogenic processes are stimulated by a combination of the hematopoietic stem cell cytokines, stem cell factor, interleukin-3, stromal derived factor-1α, and Flt-3 ligand which are added in conjunction with fibroblast growth factor (FGF)-2 into the fibrin matrix. In contrast, this tube morphogenic response does not occur under serum-free defined conditions when VEGF and FGF-2 are added together in the fibrin matrices. We recently demonstrated that VEGF and FGF-2 are able to prime EC tube morphogenic responses (i.e. added overnight prior to the morphogenic assay) to hematopoietic stem cell cytokines in collagen matrices and, interestingly, they also prime EC tube morphogenesis in 3D fibrin matrices. EC-pericyte interactions in 3D fibrin matrices leads to marked vascular basement membrane assembly as demonstrated using immunofluorescence and transmission electron microscopy. Furthermore, we show that hematopoietic stem cell cytokines and pericytes stimulate EC sprouting in fibrin matrices in a manner dependent on the α5β1 integrin. This novel co-culture system, under serum-free defined conditions, allows for a molecular analysis of EC tube assembly, pericyte recruitment and maturation events in a critical ECM environment (i.e. fibrin matrices) that regulates angiogenic events in postnatal life.
authors.affiliation: Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Sciences Center and University of Missouri School of Medicine, Columbia, Missouri, United States of America.
authors.forename: Annie O
authors.initials: AO
authors.lastname: Smith
authors.affiliation: Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Sciences Center and University of Missouri School of Medicine, Columbia, Missouri, United States of America.
authors.forename: Stephanie L K
authors.initials: SL
authors.lastname: Bowers
authors.affiliation: Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Sciences Center and University of Missouri School of Medicine, Columbia, Missouri, United States of America.
authors.forename: Amber N
authors.initials: AN
authors.lastname: Stratman
authors.affiliation: Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Sciences Center and University of Missouri School of Medicine, Columbia, Missouri, United States of America.
authors.forename: George E
authors.initials: GE
authors.lastname: Davis
mesh_terms: D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D016207:Cytokines / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism*; D005337:Fibrin / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D039081:Integrin alpha5beta1 / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D020286:Pericytes / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D016895:Culture Media, Serum-Free; D016207:Cytokines; D039081:Integrin alpha5beta1; D042461:Vascular Endothelial Growth Factor A; D016222:Fibroblast Growth Factor 2; D005337:Fibrin