title: Inhibition of human gingival gelatinases (MMP-2 and MMP-9) by metal salts.
abstract: OBJECTIVE
  The interaction between metal ions and the oral environment is a major subject matter in dental research. Matrix metalloproteinases (MMPs) have been implicated in several pathologic oral processes such as periodontal tissue destruction, root caries, tumour invasion and temporomandibular joint disorders. The aim of this work was to test the effect of Zn, Cu, Sn and Hg ions on the activity of the major gingival gelatinolytic MMPs.
  
  
  METHODS
  Gingival explants were cultured overnight in DMEM and the activity of secreted enzymes was analyzed by gelatin zymography in buffers containing different metal ion concentrations. The major gelatinolytic proteinases present in the conditioned media were characterized as MMP-2 and MMP-9 by immunoprecipitation with specific antibodies. The eletrophoretic bands were scanned and the transmittance values were analyzed with the Sigmagel software (Sigma).
  
  
  RESULTS
  ZnSO4 was a strong inhibitor of MMP-2 (I50 = 15 microM) and MMP-9 (I50 = 40 microM), whereas CuSO4, HgSO4 and SnCl2 showed less efficient inhibition potential.
  
  
  CONCLUSIONS
  Our findings show that the activity of oral tissue MMPs may be modulated by metal ions present in the oral environment. Therefore, the accumulation of metals in connective tissue may interfere with the formation and resorption of the extracellular matrix components.
authors.affiliation: Departamento de Morfologia, Faculdade de Odontologia de Piracicaba-UNICAMP, Av. Limeira, 901, 13414-018 Piracicaba SP, Brazil. serglin@fop.unicamp.br
authors.forename: A P
authors.initials: AP
authors.lastname: de Souza
authors.forename: R F
authors.initials: RF
authors.lastname: Gerlach
authors.forename: S R
authors.initials: SR
authors.lastname: Line
mesh_terms: D000328:Adult; D000906:Antibodies; D002478:Cells, Cultured; D003300:Copper / Q000494:pharmacology; D019327:Copper Sulfate / Q000494:pharmacology; D017077:Culture Media, Conditioned; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000201:enzymology; D005260:Female; D005891:Gingivitis / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D008628:Mercury / Q000494:pharmacology; D017669:Mercury Compounds / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D008875:Middle Aged; D010518:Periodontitis / Q000201:enzymology* / Q000473:pathology; D011233:Precipitin Tests; D013431:Sulfates / Q000494:pharmacology; D014001:Tin / Q000494:pharmacology; D017971:Tin Compounds / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology; D019287:Zinc Sulfate / Q000494:pharmacology
chemical_list: D000906:Antibodies; D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D017669:Mercury Compounds; D008670:Metals; D013431:Sulfates; D017971:Tin Compounds; C023599:stannous chloride; D014001:Tin; D019287:Zinc Sulfate; D003300:Copper; D008628:Mercury; D015032:Zinc; C028430:mercuric sulfate; D019327:Copper Sulfate