title: Chemically modified tetracyclines stimulate matrix metalloproteinase-2 production by periodontal ligament cells.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases.
  
  
  METHODS
  Human PDL cells were cultured with CMT-1, -3, -5, -7 or -8 in concentrations of 0, 1, 5, 10, 20, 50, 100, 200 and 500 microm. Gelatin zymography was used to determine MMP-2 and -9 production of the cells. The amount of DNA present in the cultures was analyzed using a fluorescent assay. The cytotoxicity of the CMTs was also determined. Recombinant human MMP-2 and -9 were incubated with the CMTs (0-500 microm) and their activity was analyzed using an internally quenched fluorogenic substrate.
  
  
  RESULTS
  MMP-2 production was stimulated up to sevenfold by CMT-1, -3, -7 and -8 at low concentrations (10-200 microm). No significant amounts of MMP-9 were produced. In contrast, MMP-2 and -9 activity was reduced by approximately 10-40-fold at higher concentrations (200-500 microm). CMT-5 had no effect on the production or on the activity of MMP-2 and -9. Only CMT-3 and -8 had cytotoxic effects on the PDL cells at the highest concentrations.
  
  
  CONCLUSIONS
  Surprisingly, CMTs are able to stimulate MMP-2 production at relatively low concentrations. However, at higher concentrations they exert a much stronger inhibitory effect on gelatinase activity. A possible stimulatory effect of CMTs on MMP production should be considered in their clinical use.
authors.affiliation: Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: M M
authors.initials: MM
authors.lastname: Bildt
authors.forename: A M P
authors.initials: AM
authors.lastname: Snoek-Van Beurden
authors.forename: J
authors.initials: J
authors.lastname: DeGroot
authors.forename: B
authors.initials: B
authors.lastname: Van El
authors.forename: A M
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
authors.forename: J W
authors.initials: JW
authors.lastname: Von den Hoff
mesh_terms: D000704:Analysis of Variance; D015153:Blotting, Western; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005780:Gelatin / Q000032:analysis; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis* / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D010513:Periodontal Ligament / Q000187:drug effects* / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D018709:Statistics, Nonparametric; D013754:Tetracyclines / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D011994:Recombinant Proteins; D013754:Tetracyclines; D005780:Gelatin; D004247:DNA; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9