title: Establishment of primary cultures for mouse ameloblasts as a model of their lifetime.
abstract: To understand how the properties of ameloblasts are spatiotemporally regulated during amelogenesis, two primary cultures of ameloblasts in different stages of differentiation were established from mouse enamel epithelium. Mouse primary ameloblasts (MPAs) prepared from immature enamel epithelium (MPA-I) could proliferate, whereas those from mature enamel epithelium (MPA-M) could not. MPA-M but not MPA-I caused apoptosis during culture. The mRNA expression of amelogenin, a marker of immature ameloblasts, was down-regulated, and that of enamel matrix serine proteiase-1, a marker of mature ameloblasts, was induced in MPA-I during culture. Using green fluorescence protein as a reporter, a visualized reporter system was established to analyze the promoter activity of the amelogenin gene. The region between -1102bp and -261bp was required for the reporter expression in MPA-I. These results suggest that MPAs are valuable in vitro models for investigation of ameloblast biology, and that the visualized system is useful for promoter analysis in MPAs.
authors.affiliation: Department of Biochemistry, School of Dentistry, Showa University, Tokyo 142-8555, Japan. suzawa@dent.showa-u.ac.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Suzawa
authors.forename: Nao
authors.initials: N
authors.lastname: Itoh
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Takenobu
authors.initials: T
authors.lastname: Katagiri
authors.forename: Naoko
authors.initials: N
authors.lastname: Morimura
authors.forename: Yasuna
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Kamijo
mesh_terms: D000565:Ameloblasts / Q000166:cytology*; D000818:Animals; D017209:Apoptosis; D001973:Bromodeoxyuridine / Q000494:pharmacology; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D003743:Dental Enamel / Q000166:cytology*; D017353:Gene Deletion; D017930:Genes, Reporter; D020287:In Situ Nick-End Labeling; D051379:Mice; D011401:Promoter Regions, Genetic
chemical_list: D001973:Bromodeoxyuridine