title: Expression of thymosin β4 in odontoblasts during mouse tooth development.
abstract: Thymosin β4 (Tβ4) is expressed in developing tissue, where it stimulates             cell differentiation and migration. Further, Tβ4 is expressed during molar development             in mice, but the expression and function of Tβ4 in odontoblasts during mammalian             tooth development have not yet been reported. Therefore, this study examined the             expression and function of Tβ4 in differentiating odontoblasts during tooth development.             As observed by immunohistochemistry, Tβ4 was expressed in the oral epithelium             and inside cells of the tooth bud on embryonic day 15 (E15). Further, on E17,             Tβ4 was expressed strongly in the dental lamina and oral epithelium, but only             expressed in part of the cells in the outer and inner dental epithelium. Tβ4 was             strongly expressed in the entire cytoplasm of odontoblasts on postnatal day 1             (PN1) and expressed intensively in the apical area of odontoblasts on PN4. Further,             expression of Tβ4 was increased gradually in odontoblasts from PN1 to PN21. In             an odontoblast cell line, MDPC-23, expression of Tβ4 mRNA and protein was increased             strongly on day 4 and gradually decreased from day 14. The gene expression of             dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), osteocalcin (OCN),             osteonectin (ON), and collagen type I, related with mineralization, was significantly             decreased in si-Tβ4/MDPC-23 during differentiation compared to that in MDPC-23             cells. Taken together, our results suggest that Tβ4 may be involved in oral epithelial             cell proliferation at the initial stage of tooth development and regulates the             expression and secretion of proteins during odontoblast differentiation.
authors.affiliation: Department of Oral Histology and Developmental Biology, School                     of Dentistry, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Baik-Dong
authors.initials: BD
authors.lastname: Choi
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Yun
authors.forename: Soon-Jeong
authors.initials: SJ
authors.lastname: Jeong
authors.forename: Guanlin
authors.initials: G
authors.lastname: Wang
authors.forename: Heung-Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Do-Seon
authors.initials: DS
authors.lastname: Lim
authors.forename: Moon-Jin
authors.initials: MJ
authors.lastname: Jeong
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D009804:Odontoblasts / Q000166:cytology* / Q000378:metabolism*; D009805:Odontogenesis; D012333:RNA, Messenger / Q000235:genetics; D013947:Thymosin / Q000032:analysis / Q000235:genetics*; D014070:Tooth / Q000166:cytology / Q000254:growth & development*; D000099201:Thymosin beta(4)
chemical_list: D012333:RNA, Messenger; D013947:Thymosin; D000099201:Thymosin beta(4)