title: Localization of MMP-2, MMP-9, TIMP-1, and TIMP-2 in human coronal dentine.
abstract: OBJECTIVE
  Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) play important roles in dentine formation, caries progression and hybrid layer degradation. This study tested the hypothesis that the distribution and concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 are different at different depths of human coronal dentine, including odontoblasts.
  
  
  METHODS
  Protein localization was performed using immunohistochemistry. Co-localization of the MMPs and their inhibitors was conducted using immunofluorescence double labelling. Protein concentrations were measured by ELISA and gelatinolytic potential was assessed with gelatine zymography.
  
  
  RESULTS
  MMP-2 was the main gelatinase in dentine and was concentrated in the odontoblasts, deep dentine and the dentinoenamel junction. TIMP-2 was co-localized with MMP-2 mainly in the odontoblasts but its concentration was low. Both MMP-9 and TIMP-1 showed a decreasing distribution from the deep to the superficial dentine layers; however, the concentration of TIMP-1 was much higher than that of MMP-9. The gelatinolytic potential of dentine protein extracts decreased gradually from deep to superficial dentine.
  
  
  CONCLUSIONS
  The concentrations and distribution patterns of MMP-2, MMP-9, TIMP-1 and TIMP-2, and the gelatinolytic potential of dentine matrix are variable along different dentine depths. Thus, differential collagen degradation potentials may be expected depending upon the depth in which dentine is exposed.
authors.affiliation: Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, 145 West Changle Road, Xi'an, China.
authors.forename: L N
authors.initials: LN
authors.lastname: Niu
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Jiao
authors.forename: F
authors.initials: F
authors.lastname: Li
authors.forename: Y X
authors.initials: YX
authors.lastname: Ding
authors.forename: D Y
authors.initials: DY
authors.lastname: Wang
authors.forename: M Q
authors.initials: MQ
authors.lastname: Wang
authors.forename: F R
authors.initials: FR
authors.lastname: Tay
authors.forename: J H
authors.initials: JH
authors.lastname: Chen
mesh_terms: D003743:Dental Enamel / Q000201:enzymology; D003804:Dentin / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D009804:Odontoblasts / Q000201:enzymology; D011480:Protease Inhibitors / Q000032:analysis*; D011506:Proteins / Q000032:analysis; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000032:analysis*; D019228:Tooth Crown / Q000201:enzymology
chemical_list: D011480:Protease Inhibitors; D011506:Proteins; C560822:TIMP1 protein, human; C560823:TIMP2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9