title: Phosphodiesterase inhibition mediates matrix metalloproteinase activity and the level of collagen degradation fragments in a liver fibrosis ex vivo rat model.
abstract: BACKGROUND
  Accumulation of extracellular matrix (ECM) and increased matrix metalloproteinase (MMP) activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl(4) treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M), known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model.
  
  
  RESULTS
  In vivo: Rats were treated for 8 weeks with CCl(4)/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control) or treated with IBMX (phosphodiesterase inhibitor). Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography. Ex vivo: The levels of serum C3M increased 77% in the CCl(4)-treated rats at week 8 (p < 0.01); Levels of C3M increased significantly by 100% in fibrotic liver slices compared to controls after 48 hrs (p < 0.01). By adding GM6001 or IBMX to the media, C3M was restored to control levels. Gelatin zymography demonstrated CCl(4)-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals.
  
  
  CONCLUSIONS
  We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.
authors.affiliation: Nordic Bioscience A/S, Herlev Hovedgade 207, 2730, Herlev, Denmark.
authors.forename: Sanne Skovgård
authors.initials: SS
authors.lastname: Veidal
authors.forename: Mette Juul
authors.initials: MJ
authors.lastname: Nielsen
authors.forename: Diana Julie
authors.initials: DJ
authors.lastname: Leeming
authors.forename: Morten Asser
authors.initials: MA
authors.lastname: Karsdal
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000818:Animals; D002470:Cell Survival / Q000502:physiology; D024061:Collagen Type III / Q000097:blood / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007150:Immunohistochemistry; D008103:Liver Cirrhosis / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D024061:Collagen Type III; D010726:Phosphodiesterase Inhibitors; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D020780:Matrix Metalloproteinase 9; D015056:1-Methyl-3-isobutylxanthine