title: Human vascular endothelial cells produce tumor necrosis factor-alpha in response to proinflammatory cytokine stimulation.
abstract: OBJECTIVE
  To determine whether human vascular endothelial cells produce tumor necrosis factor-alpha (TNF-alpha) after stimulation with proinflammatory cytokines and bacterial lipopolysaccharides (LPS).
  
  
  METHODS
  Prospective, in vitro repeated-measurements analysis of cellular responses.
  
  
  METHODS
  Research laboratory in an academic medical center.
  
  
  METHODS
  Human umbilical vein endothelial cells (HUVECs).
  
  
  METHODS
  HUVECs were incubated with interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta), and LPS, or their different combinations for 2 to 48 hrs.
  
  
  RESULTS
  TNF-alpha was measured by time-resolved immunofluorometric assay. Unstimulated HUVECs did not produce detectable amounts of TNF-alpha, but IFN-gamma, IL-1beta, and LPS when added together induced TNF-alpha production of HUVECs in a time-dependent manner. Immunofluorescent staining confirmed that the TNF-alpha was produced by endothelial cells. IFN-gamma, IL-1beta, or LPS alone did not induce TNF-alpha production, whereas IFN-gamma and IL-1beta in combination were able to induce TNF-alpha production to some extent, and the production could be further increased with LPS. TNF-alpha messenger RNA expression was detected with reverse transcriptase-coupled polymerase chain reaction in stimulated, but not in unstimulated, HUVECs.
  
  
  CONCLUSIONS
  HUVECs are capable of producing TNF-alpha after proinflammatory cytokine stimulation and may therefore contribute to the increased amount of TNF-alpha found in pathologic states such as septic shock.
authors.affiliation: Department of Obstetrics and Gynecology, University of Helsinki, Finland.
authors.forename: V
authors.initials: V
authors.lastname: Ranta
authors.forename: A
authors.initials: A
authors.lastname: Orpana
authors.forename: O
authors.initials: O
authors.lastname: Carpén
authors.forename: U
authors.initials: U
authors.lastname: Turpeinen
authors.forename: O
authors.initials: O
authors.lastname: Ylikorkala
authors.forename: L
authors.initials: L
authors.lastname: Viinikka
mesh_terms: D002452:Cell Count; D002478:Cells, Cultured; D003470:Culture Media; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015200:Fluoroimmunoassay; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D011446:Prospective Studies; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012486:Salmonella typhimurium; D013268:Stimulation, Chemical; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D003470:Culture Media; D007375:Interleukin-1; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma