title: Glucocorticoid-mediated inhibition of angiogenic changes in human endothelial cells is not caused by reductions in cell proliferation or migration.
abstract: BACKGROUND
  Glucocorticoid-mediated inhibition of angiogenesis is important in physiology, pathophysiology and therapy. However, the mechanisms through which glucocorticoids inhibit growth of new blood vessels have not been established. This study addresses the hypothesis that physiological levels of glucocorticoids inhibit angiogenesis by directly preventing tube formation by endothelial cells.
  
  
  RESULTS
  Cultured human umbilical vein (HUVEC) and aortic (HAoEC) endothelial cells were used to determine the influence of glucocorticoids on tube-like structure (TLS) formation, and on cellular proliferation (5-bromo-2'-deoxyuridine (BrdU) incorporation), viability (ATP production) and migration (Boyden chambers). Dexamethasone or cortisol (at physiological concentrations) inhibited both basal and prostaglandin F(2α) (PGF(2α))-induced and vascular endothelial growth factor (VEGF) stimulated TLS formation in endothelial cells (ECs) cultured on Matrigel, effects which were blocked with the glucocorticoid receptor antagonist RU38486. Glucocorticoids had no effect on EC viability, migration or proliferation. Time-lapse imaging showed that cortisol blocked VEGF-stimulated cytoskeletal reorganisation and initialisation of tube formation. Real time PCR suggested that increased expression of thrombospodin-1 contributed to glucocorticoid-mediated inhibition of TLS formation.
  
  
  CONCLUSIONS
  We conclude that glucocorticoids interact directly with glucocorticoid receptors on vascular ECs to inhibit TLS formation. This action, which was conserved in ECs from two distinct vascular territories, was due to alterations in cell morphology rather than inhibition of EC viability, migration or proliferation and may be mediated in part by induction of thrombospodin-1. These findings provide important insights into the anti-angiogenic action of endogenous glucocorticoids in health and disease.
authors.affiliation: Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: James J
authors.initials: JJ
authors.lastname: Logie
authors.forename: Sadaf
authors.initials: S
authors.lastname: Ali
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Marshall
authors.forename: Margarete M S
authors.initials: MM
authors.lastname: Heck
authors.forename: Brian R
authors.initials: BR
authors.lastname: Walker
authors.forename: Patrick W F
authors.initials: PW
authors.lastname: Hadoke
mesh_terms: D001011:Aorta / Q000166:cytology; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D003094:Collagen / Q000737:chemistry; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology*; D005938:Glucocorticoids / Q000737:chemistry*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007797:Laminin / Q000737:chemistry; D015735:Mifepristone / Q000494:pharmacology; D009389:Neovascularization, Pathologic; D011509:Proteoglycans / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019700:Thrombospondin 1 / Q000096:biosynthesis; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D004338:Drug Combinations; D005938:Glucocorticoids; D007797:Laminin; D011509:Proteoglycans; D019700:Thrombospondin 1; C059485:matrigel; D015735:Mifepristone; D003094:Collagen; D001973:Bromodeoxyuridine; D006854:Hydrocortisone