title: Amelogenin and enamelysin localization in human dental germs.
abstract: Odontogenesis is extensively studied in animal models but less understood in human. In early amelogenesis, amelogenin constitutes 90% of enamel organic matrix, which is degraded by enamelysin and replaced by hydroxyapatite crystals. Here, amelogenin and enamelysin distribution changes during amelogenesis were shown by co-localization experiments by confocal microscopy. Early bell stage showed more amelogenin labeling than enamelysin, as free immune-reactive granular patches towards basal membrane between ameloblast and odontoblast. Increased amelogenin expression and secretion towards extracellular matrix formation region was found. Enamelysin distribution was perinuclear in early bell stage. During late bell stage, a decreasing amelogenin labeling in contrast with enamelysin increasing along the cells was found, suggesting specific temporal amelogenin degradation. Enamelysin was located initially around nuclei and later was found in all the ameloblast and stellate reticulum cytoplasm. Amelogenin was observed inside ameloblast, stellate reticulum, and intermediate stratum cells in the enamel as well as in the newly formed dentin extracellular matrix. In contrast, in dentin more amelogenin than enamelysin was found located close to the periphery.
authors.affiliation: Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, C. U. Aguascalientes, Aguascalientes, Mexico.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Gutiérrez-Cantú
authors.forename: Alfredo
authors.initials: A
authors.lastname: Feria-Velasco
authors.forename: Laura Nayeli
authors.initials: LN
authors.lastname: Palacios-Arenas
authors.forename: Keila Neri
authors.initials: KN
authors.lastname: Alvarado-Estrada
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Avelar-González
authors.forename: Héctor
authors.initials: H
authors.lastname: Flores-Reyes
authors.forename: Jairo
authors.initials: J
authors.lastname: Mariel-Cárdenas
authors.forename: Alma Lilián
authors.initials: AL
authors.lastname: Guerrero-Barrera
mesh_terms: D000565:Ameloblasts / Q000737:chemistry* / Q000378:metabolism; D053523:Amelogenin / Q000032:analysis*; D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D003743:Dental Enamel / Q000737:chemistry / Q000378:metabolism; D003746:Dental Enamel Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D053519:Matrix Metalloproteinase 20 / Q000032:analysis*; D018613:Microscopy, Confocal; D051381:Rats
chemical_list: D053523:Amelogenin; D003746:Dental Enamel Proteins; D053519:Matrix Metalloproteinase 20