title: Immunohistochemical and biochemical assay of MMP-3 in human dentine.
abstract: OBJECTIVE
  The function of endogenous MMP-3 and its distribution within the human dentine is unclear. Thus, the aim of the present study was to assay the presence and distribution of MMP-3 within human sound dentine by means of biochemical and immunohistochemical assays.
  
  
  METHODS
  Powdered dentine from extracted human teeth was prepared and (1) partially demineralised with 1% H(3)PO(4) for 10min or (2) untreated (control). The presence of MMP-3 was measured using a colorimetric assay system (QuantiSir™, Epigentek, USA). Additional cryo-fractured dentine fragments were processed for immunohistochemical identification of MMP-3 under FEI-SEM. Casein-zymography was used to investigate MMP-3 activity.
  
  
  RESULTS
  MMP-3 detected level was 2.732ng/μL in partially demineralised dentine powder, whilst it increased to 3.280ng/μL in mineralised dentine. The FEI-SEM analysis revealed positive immunolabelling patterns for MMP-3, predominantly localized on the intertubular collagen fibrillar network showing MMP-3 directly or indirectly bound to the collagen fibrils. Casein-zymograms showed positive proteolytic activity for MMP-3 in demineralised dentine powder.
  
  
  CONCLUSIONS
  The results of the study clearly revealed the presence and distribution of MMP3 in human sound dentine. Whilst the presence was verified, its role is still unclear. Future studies are needed to investigate the possible involvement of MMP-3 in physiological and pathological condition of the dentine-pulp complex.
authors.affiliation: Department of SAU&FAL, University of Bologna, Bologna, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Mazzoni
authors.forename: Veronica
authors.initials: V
authors.lastname: Papa
authors.forename: Fernando
authors.initials: F
authors.lastname: Nato
authors.forename: Marcela
authors.initials: M
authors.lastname: Carrilho
authors.forename: Leo
authors.initials: L
authors.lastname: Tjäderhane
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ruggeri
authors.forename: Pietro
authors.initials: P
authors.lastname: Gobbi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mazzotti
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Breschi
mesh_terms: D000911:Antibodies, Monoclonal; D002364:Caseins / Q000032:analysis; D003094:Collagen / Q000032:analysis / Q000648:ultrastructure; D003124:Colorimetry / Q000379:methods; D003648:Decalcification Technique; D003804:Dentin / Q000201:enzymology* / Q000648:ultrastructure; D005614:Freeze Fracturing; D006801:Humans; D007150:Immunohistochemistry; D019278:Matrix Metalloproteinase 3 / Q000032:analysis*; D008855:Microscopy, Electron, Scanning
chemical_list: D000911:Antibodies, Monoclonal; D002364:Caseins; D003094:Collagen; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3