title: Essential roles of ameloblastin in maintaining ameloblast differentiation and enamel formation.
abstract: During tooth development, dental epithelial cells interact with extracellular matrix components, such as the basement membrane and enamel matrix. Ameloblastin, an enamel matrix protein, plays a crucial role in maintaining the ameloblast differentiation state and is essential for enamel formation. Ameloblastin-null mice developed severe enamel hypoplasia. In mutant mice, dental epithelial cells started to differentiate into ameloblasts, but ameloblasts soon lost cell polarity, proliferated, and formed multiple cell layers, indicative of some aspects of preameloblast phenotypes. In addition, the expression of amelogenin, another component of the enamel matrix, was specifically reduced in mutant ameloblasts. More than 20% of amelobastin-null mice developed odontogenic tumors. We also found that recombinant ameloblastin specifically bound to ameloblasts and inhibited proliferation of dental epithelial cells. These results suggest that ameloblastin is an important regulator to maintain the differentiation state of ameloblasts.
authors.affiliation: Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Faculty of Dental Science, Kyushu University, Fukuoka, Japan. fukumoto@dent.kyushu-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Aya
authors.initials: A
authors.lastname: Yamada
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nonaka
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000565:Ameloblasts / Q000166:cytology* / Q000378:metabolism; D000566:Amelogenesis / Q000235:genetics*; D000818:Animals; D002454:Cell Differentiation; D003743:Dental Enamel / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D003746:Dental Enamel Proteins / Q000235:genetics / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D051379:Mice; D008817:Mice, Mutant Strains; D009369:Neoplasms / Q000235:genetics; D014070:Tooth / Q000254:growth & development
chemical_list: C490890:Ambn protein, mouse; D003746:Dental Enamel Proteins; D016326:Extracellular Matrix Proteins