title: [Localization and quantitative detection of matrix metalloproteinase in human coronal dentine].
abstract: OBJECTIVE
  To compare the distribution and concentrations of matrix metalloproteinase (MMP)-1, 2, 3, 8, 9 in human coronal dentin.
  
  
  METHODS
  The localization of five types of MMP was performed using immunohistochemistry. Molars were demineralized and sectioned into 5 µm thick specimens. All specimens were randomly divided into five groups according to the antibodies. Each group contained two subgroups (n = 6). Immunoreactivity of each subgroup was visualized with 3, 3-diaminobenzidine solution or fluorescein isothiocyanate and observed under microscopy respectively. Molars were sectioned into slices. The slices were divided into two groups according to superficial or deep dentin and pulverized to fine powder. After dentin protein was extracted, the concentrations of MMP-1, 2, 3, 8, 9 were detected by using fluorescent microsphere immunoassay.
  
  
  RESULTS
  Immunohistochemical staining revealed that MMP-1, 2, 3, 8, 9 were highly concentrated in the deep dentin. However, intense immunoreactivities of MMP-2, 8, 9 were identified in a 6-10 µm wide zone adjacent to the dentino-enamel junction. The content of MMP-1 in superficial layer and deep layer of dentin were (0.037±0.025) and (0.433±0.089) ng/mg. The content of MMP-2 in superficial layer and deep layer of dentin were (0.445±0.115) and (2.730±0.712) ng/mg. The content of MMP-3 in superficial layer and deep layer of dentin were (0.071±0.069) and (0.460±0.108) ng/mg. The content of MMP-8 in superficial layer and deep layer of dentin were (0.586±0.246) and (6.159±0.948) ng/mg. The content of MMP-9 in superficial layer and deep layer of dentin were (0.384±0.185) and (1.460±0.251) ng/mg. The concentrations of all tested MMP were significantly higher in deep dentin than those in superficial dentin (P < 0.05).
  
  
  CONCLUSIONS
  There are five types of MMP contained in human coronal dentin, and the distribution of MMP shows a decreasing trend from the deep dentin to the superficial dentin.
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Danyang
authors.initials: D
authors.lastname: Wang
authors.affiliation: Email: zhang.ling1978@gmail.com.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Keqiang
authors.initials: K
authors.lastname: Ma
authors.forename: Jihua
authors.initials: J
authors.lastname: Chen
mesh_terms: D003743:Dental Enamel; D003804:Dentin / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D020781:Matrix Metalloproteinase 1; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008963:Molar
chemical_list: D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1