title: Inhibition of synoviocyte collagenase gene expression by adenosine receptor stimulation.
abstract: OBJECTIVE
  To characterize the regulation of matrix metalloproteinases (MMPs) by adenosine.
  
  
  METHODS
  Cultured fibroblast-like synoviocytes (FLS) were stimulated with interleukin-1 (IL-1) in the presence or absence of adenosine receptor agonists. Immunoreactive MMPs were measured using specific enzyme-linked immunosorbent assays, and gene expression was assessed by Northern blot analysis.
  
  
  RESULTS
  The nonselective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) decreased collagenase production by IL-1-stimulated synoviocytes from 196 +/- 28 ng/ml (mean +/- SEM) to 66 +/- 9 ng/ml (P < 0.001). There was minimal effect on stromelysin production (decrease from 107 +/- 16 ng/ml to 97 +/- 15 ng/ml). Selective adenosine receptor agonists implicated the A2b adenosine receptor in this activity, and reverse transcriptase-polymerase chain reaction studies confirmed that FLS express this receptor. Northern blot analysis demonstrated that the mechanism of action was pre-translational since NECA decreased collagenase, but not stromelysin or tissue inhibitor of metalloproteinases 1 (TIMP-1), messenger RNA levels. Cyclic AMP levels were increased by NECA, and a direct adenylate cyclase activator (forskolin) also suppressed collagenase gene expression. These data suggest that cAMP mediates the inhibitory effect of NECA on collagenase production.
  
  
  CONCLUSIONS
  Stimulation of the A2b receptor on FLS decreases collagenase gene expression, with little or no effect on stromelysin and TIMP-1. The combination of antiinflammatory and MMP-regulating properties of adenosine or adenosine-regulating agents suggest that treatment based on this approach might be useful in rheumatoid arthritis.
authors.affiliation: Gensia, Inc., San Diego, California 92093, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Boyle
authors.forename: F G
authors.initials: FG
authors.lastname: Sajjadi
authors.forename: G S
authors.initials: GS
authors.lastname: Firestein
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D001483:Base Sequence; D002478:Cells, Cultured; D017364:Collagenases / Q000378:metabolism*; D000242:Cyclic AMP / Q000502:physiology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D019278:Matrix Metalloproteinase 3; D008666:Metalloendopeptidases / Q000187:drug effects / Q000378:metabolism; D008969:Molecular Sequence Data; D058906:Purinergic P1 Receptor Agonists; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000378:metabolism; D018047:Receptors, Purinergic P1 / Q000737:chemistry; D013583:Synovial Membrane / Q000166:cytology / Q000201:enzymology*; D013997:Time Factors
chemical_list: D007375:Interleukin-1; D058906:Purinergic P1 Receptor Agonists; D012333:RNA, Messenger; D018047:Receptors, Purinergic P1; D019830:Adenosine-5'-(N-ethylcarboxamide); D000242:Cyclic AMP; D017364:Collagenases; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3; D000241:Adenosine