title: Human embryo-conditioned medium stimulates in vitro endometrial angiogenesis.
abstract: OBJECTIVE
  Successful implantation and placentation depend on the interaction between the endometrium and the embryo. Angiogenesis is crucial at this time. In this article we investigate the direct influence of the human embryo on in vitro endometrial angiogenesis.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Human endometrial microvascular endothelial cells (hEMVEC) grown on an in vitro angiogenesis model.
  
  
  METHODS
  Conditioned media (CM) of human embryos were used to stimulate in vitro angiogenesis.
  
  
  METHODS
  In vitro angiogenesis of hEMVEC.
  
  
  RESULTS
  Conditioned media of human embryos, containing significant amounts of vascular endothelial growth factor (VEGF)-A, as determined by enzyme-linked immunosorbent assay (ELISA), caused an increase in hEMVEC tube formation. This effect was prevented by soluble VEGF receptor 1, which quenches VEGF-A activity. Recombinant EGF alone and leukemia inhibitory factor in combination with VEGF-A stimulated hEMVEC tube formation. None of the other tested recombinant mediators, which have been described as produced by the early embryo/trophoblast (interleukin (IL) 10, transforming growth factor (TGF) beta, placental growth factor, hCG, colony-stimulating factor 1, interferon-gamma, insulin-like growth factor I and II, IL-6, platelet-derived growth factor, and TGFalpha), had an effect on tube formation by hEMVEC.
  
  
  CONCLUSIONS
  For the first time, it is shown that the human embryo is able to stimulate in vitro endometrial angiogenesis at the time of implantation, a process that is mediated by VEGF-A.
authors.affiliation: Division of Biomedical Research, TNO Quality of Life, Leiden, The Netherlands.
authors.forename: Kitty
authors.initials: K
authors.lastname: Kapiteijn
authors.forename: Pieter
authors.initials: P
authors.lastname: Koolwijk
authors.forename: Robin M F
authors.initials: RM
authors.lastname: van der Weiden
authors.forename: Geerten
authors.initials: G
authors.lastname: van Nieuw Amerongen
authors.forename: Margreet
authors.initials: M
authors.lastname: Plaisier
authors.forename: Victor W M
authors.initials: VW
authors.lastname: van Hinsbergh
authors.forename: Frans M
authors.initials: FM
authors.lastname: Helmerhorst
mesh_terms: D042501:Angiogenic Proteins / Q000494:pharmacology*; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D042501:Angiogenic Proteins; D017077:Culture Media, Conditioned