title: H2 O2 activates matrix metalloproteinases through the nuclear factor kappa B pathway and Ca(2+) signals in human periodontal fibroblasts.
abstract: BACKGROUND
  The mechanisms involved in reactive oxygen species and matrix metalloproteinase (MMP)-mediated periodontal tissue breakdown are unknown.
  
  
  OBJECTIVE
  To determine the effect of H2 O2 in MMP-2 and MMP-9 activity, and the involvement of nuclear factor kappa B (NFκB) and Ca(2+) -mediated signals in human periodontal ligament fibroblasts.
  
  
  METHODS
  Primary cultures were characterized for their phenotype and exposed for 24 h to sublethal doses (2.5-10 μm) of H2 O2 or control media. NFκB involvement was evaluated through immunofluorescence of p65 subunit, using the NFκB blocking peptide SN50 and catalase. Ca(2+) signals were analyzed by loading the cells with Fluo4-AM and recording the fluorescence changes in a confocal microscope before and after the addition of H2 O2 . 1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl was used to chelate intracellular Ca(2+) . The activity and levels of MMP-2 and MMP-9 were analyzed by gelatin zymogram and densitometric scanning, and enzyme-linked immunosorbent assay, respectively. Statistical analysis was performed with stata V11.1 software using the ANOVA test.
  
  
  RESULTS
  H2 O2 at concentrations of 2.5-5 μm induced Ca(2+) signaling and NFκB subunit p65 nuclear translocation, whereas catalase, SN50 and BAPTA-AM prevented p65 nuclear translocation. H2 O2 at 2.5-5 μm significantly increased MMP-9 and MMP-2 activity, while SN50 resulted in lower MMP-2 and MMP-9 activity rates compared with controls.
  
  
  CONCLUSIONS
  Sublethal H2 O2 induces Ca(2+) -dependent NFκB signaling with an increase in MMP gelatinolytic activity in human periodontal ligament.
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Osorio
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.|Laboratory of Periodontal Biology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.
authors.forename: F
authors.initials: F
authors.lastname: Cavalla
authors.affiliation: Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Paula-Lima
authors.affiliation: Department of Chemical Pharmacology and Toxicology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile.
authors.forename: G
authors.initials: G
authors.lastname: Díaz-Araya
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.|Laboratory of Periodontal Biology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.
authors.forename: R
authors.initials: R
authors.lastname: Vernal
authors.affiliation: Laboratory of Periodontal Biology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.
authors.forename: P
authors.initials: P
authors.lastname: Ahumada
authors.affiliation: Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.|Laboratory of Periodontal Biology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.
authors.forename: J
authors.initials: J
authors.lastname: Gamonal
authors.affiliation: Laboratory of Periodontal Biology, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.|Department of Pathology, Faculty of Dentistry Universidad de Chile, Santiago, Chile.
authors.forename: M
authors.initials: M
authors.lastname: Hernández
mesh_terms: D000328:Adult; D020013:Calcium Signaling; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010513:Periodontal Ligament / Q000166:cytology; D013312:Stress, Physiological
chemical_list: D016328:NF-kappa B; D006861:Hydrogen Peroxide; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9
keywords: Ca2+; H
  2
  O
  2; matrix metalloproteinases; nuclear factor kappa B; periodontal fibroblasts