title: Increased matrix metalloproteinase-2 and bone sialoprotein response to human coronal caries.
abstract: BACKGROUND
  It has been suggested that host matrix metalloproteinase-2 (MMP-2) present in dentin may be involved in caries progression, however, its response to caries is not known. Bone sialoprotein (BSP) has been implicated in dentin mineralization and MMP-2 modulation.
  
  
  OBJECTIVE
  To identify and compare the distribution of MMP-2 and BSP in healthy human coronal dentin and those with early caries.
  
  
  METHODS
  Freshly extracted 3rd molars and premolars with and without early caries were fixed, demineralized and subjected to immunohistochemistry using a monoclonal anti-MMP-2 antibody and monoclonal anti-BSP antibody with an avidin-biotin complex method. Immunoreactivity was visualized with 3,3'-diaminobenzidine substrate and observed under light microscopy.
  
  
  RESULTS
  Immunohistochemical analysis revealed that MMP-2 and BSP are not detected in the tubule lumens of healthy dentin. However, intense immunoreactivity for MMP-2 and BSP was detected in association with the full length of the caries-affected dentinal tubules. The MMP-2 and BSP at the dentino-enamel junction appeared unaltered.
  
  
  CONCLUSIONS
  The results indicate that MMP-2 and BSP may be actively secreted by odontoblasts in response to carious insult. MMP-2 and BSP accumulation in the caries-affected dentinal tubules may indicate their potential involvement in the host defense mechanism which results in calcification of regions affected by the carious process.
authors.affiliation: Department of Operative Dentistry, University of North Carolina, Chapel Hill, NC 27599, USA. boushell@dentistry.unc.edu
authors.forename: L W
authors.initials: LW
authors.lastname: Boushell
authors.forename: H
authors.initials: H
authors.lastname: Nagaoka
authors.forename: H
authors.initials: H
authors.lastname: Nagaoka
authors.forename: M
authors.initials: M
authors.lastname: Yamauchi
mesh_terms: D015100:3,3'-Diaminobenzidine; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D003731:Dental Caries / Q000201:enzymology / Q000473:pathology*; D003743:Dental Enamel / Q000201:enzymology / Q000648:ultrastructure; D003804:Dentin / Q000201:enzymology / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007150:Immunohistochemistry; D058574:Integrin-Binding Sialoprotein / Q000032:analysis*; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D009804:Odontoblasts / Q000201:enzymology / Q000473:pathology; D019228:Tooth Crown / Q000201:enzymology / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal; D058574:Integrin-Binding Sialoprotein; D015100:3,3'-Diaminobenzidine; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2