title: Immunohistochemical localization of MMP-2, MMP-9, TIMP-1, and TIMP-2 in the forming rat incisor.
abstract: Western blots analyses and gelatin zymography established the presence of matrix metalloproteinase (MMP)-2 and -9 in the forming zone of rat incisor. Light microscope immunohistochemistry carried out on undemineralized material provided evidence for strong MMP-2 staining in the secretory ameloblasts, odontoblasts, in the enamel organ, and in the pulp. A weaker staining was observed in predentin and in the outer part of the forming enamel. Using MMP-9 antibodies, the staining was generally weak, except for the secretory ameloblasts that were positively stained. Electron microscopic immunohistochemistry of undemineralized sections revealed a close association between gold-antibodies complexes and cytoskeletal microfilaments in the cytosol of secretory ameloblasts and odontoblasts, within the rough endoplasmic reticulum and along the plasma membrane. The striking feature of MMP-2 and -9 electron immunostaining was the particularly high labeling in the mantle dentin. By contrast, staining of tissue inhibitors of metalloproteinases (TIMP-1 and -2) was lowest in this region. We suggest that this uneven distribution may have some functional implications.
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000565:Ameloblasts / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003786:Dental Pulp Cavity / Q000378:metabolism / Q000648:ultrastructure; D003804:Dentin / Q000378:metabolism / Q000648:ultrastructure; D004658:Enamel Organ / Q000378:metabolism / Q000648:ultrastructure; D018870:Endoplasmic Reticulum, Rough / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D007180:Incisor / Q000201:enzymology* / Q000254:growth & development* / Q000648:ultrastructure; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008854:Microscopy, Electron; D009804:Odontoblasts / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*
chemical_list: D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9