Localization of matrix metalloproteinases (MMPs-2, 8, 9 and 20) in normal and carious dentine.
Aust Dent J. 2009 Dec;54(4):347-54
Authors: Shimada Y, Ichinose S, Sadr A, Burrow MF, Tagami J
Abstract
BACKGROUND: Dentine matrix metalloproteinases (MMPs) may participate in the destruction of dentine following demineralization by bacterial acids. This study investigated the localization of MMPs in carious dentine.
METHODS: Frozen sections of dentine caries were prepared without demineralization and immersed in monoclonal antibody against MMP-2, -8, -9 and -20. The sections were labelled by IgG conjugated with gold colloidal particles, and observed under FE-SEM. Labelling indexes (number of gold particles/mum(2)) of outer and inner carious dentine, respectively, with and without bacterial infection, were compared with that of normal dentine.
RESULTS: MMP-2 was distributed in both carious and normal dentine; the level of MMP-2 showed no significant difference among the outer caries, inner caries, and normal dentine. The labelling indexes of MMP-8 and MMP-9 both significantly decreased at the inner carious dentine compared with the level of normal dentine, but intensified again at the outer caries region. The labelling index of MMP-20 was the highest at normal dentine.
CONCLUSIONS: The localization of MMPs was visibly detected using immunogold labelling. The localization of MMP-2 showed no significant difference among the three regions, while MMP-8 and MMP-9 showed significant reduction at the inner caries layer, and MMP-20 reduced toward the outer caries.
[cite source='pubmed']20415934[/cite] – indexed for MEDLINE]