title: Modulation of angiogenic vascular endothelial growth factor by tumor necrosis factor alpha and interleukin-1 in rheumatoid arthritis.
abstract: OBJECTIVE
  To investigate the regulation of expression of the angiogenic cytokine vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA), in order to determine whether new blood vessel formation could be a potential therapeutic target in RA.
  
  
  METHODS
  Dissociated RA synovial membrane cells were cultured in the presence of cytokine inhibitors, or under hypoxic conditions. Serum VEGF levels were serially measured in RA patients enrolled in clinical trials of anti-tumor necrosis factor alpha (anti-TNFalpha) monoclonal antibody treatment.
  
  
  RESULTS
  Combined neutralization of TNFalpha and interleukin-1 (IL-1) in RA synovial membrane cultures reduced VEGF release by 45% (P < 0.05 versus control), although blockade of either TNFalpha or IL-1 activities alone resulted in only small inhibitory effects. In addition, release of VEGF from RA synovial membrane cells was selectively up-regulated by hypoxia. Serum VEGF levels were significantly elevated in RA patients relative to control subjects, and correlated with disease activity. Treatment of RA patients with anti-TNFalpha significantly decreased serum VEGF, and this effect was enhanced by cotreatment with methotrexate.
  
  
  CONCLUSIONS
  Inhibition of TNFalpha and IL-1 activity in vivo could reduce the drive to new blood vessel formation, and hence pannus mass, adding to other therapeutic effects of anti-TNFalpha therapy in RA.
authors.affiliation: Kennedy Institute of Rheumatology, London, UK.
authors.forename: E M
authors.initials: EM
authors.lastname: Paleolog
authors.forename: S
authors.initials: S
authors.lastname: Young
authors.forename: A C
authors.initials: AC
authors.lastname: Stark
authors.forename: R V
authors.initials: RV
authors.lastname: McCloskey
authors.forename: M
authors.initials: M
authors.lastname: Feldmann
authors.forename: R N
authors.initials: RN
authors.lastname: Maini
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D016228:Endothelial Growth Factors / Q000097:blood / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D008222:Lymphokines / Q000097:blood / Q000378:metabolism*; D008727:Methotrexate / Q000494:pharmacology; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors; D012795:Sialoglycoproteins / Q000494:pharmacology; D013583:Synovial Membrane / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000276:immunology / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D000911:Antibodies, Monoclonal; D016228:Endothelial Growth Factors; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D008222:Lymphokines; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D008727:Methotrexate