title: Promotion of mouse ameloblast proliferation by Lgr5 mediated integrin signaling.
abstract: Rodent incisors grow throughout the animal's lives, and the tooth-forming cells are provided from proximal ends of the incisors where the tooth epithelium forms a stem cell niche called cervical loop. The committing cells in a cervical loop actively begin to proliferate (pre-ameloblasts), and differentiating into ameloblasts. This study showed that the lower incisors of mice null for CD61 (CD61(-/-) ), also known as integrin β3, were significantly shorter than those of the wild-type mice at 8-week-old. The protein and mRNA expressions levels of Fgfr2, Lgr5, and Notch1, which are known to be involved in pre-ameloblastic cell proliferation and stem cell maintenance, were reduced in the cervical loop of 2-week-old CD61(-/-) mice. The proliferation of pre-ameloblasts was reduced in CD61(-/-) ameloblasts. The siRNA-mediated suppression of CD61 (siCD61) reduced the proliferation of pre-ameloblastic cell line ALC, and the expression levels of Lgr5 and Notch1 were reduced by the transfection with siCD61. The suppression of Lgr5 by transfection with siLgr5 suppressed the proliferation of the ALC cells. These results suggested that CD61 signaling is required for the proper growth of the cervical loop and for the promotion of the proliferation of pre-ameloblastic cells through Lgr5.
authors.affiliation: Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yoshida
authors.forename: Takanori
authors.initials: T
authors.lastname: Iwata
authors.forename: Terumasa
authors.initials: T
authors.lastname: Umemoto
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Shiratsuchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawashima
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D000565:Ameloblasts / Q000166:cytology* / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D007150:Immunohistochemistry; D007180:Incisor / Q000254:growth & development / Q000378:metabolism; D039661:Integrin beta3 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009805:Odontogenesis / Q000235:genetics / Q000502:physiology; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000235:genetics / Q000378:metabolism; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D014057:Tomography, X-Ray Computed
chemical_list: D039661:Integrin beta3; C493597:Lgr5 protein, mouse; D051881:Receptor, Notch1; D043562:Receptors, G-Protein-Coupled; D051497:Receptor, Fibroblast Growth Factor, Type 2
keywords: CELL PROLIFERATION; HYPOPLASIA; INCISOR; ODONTOGENESIS; STEM CELL; TRANSGENIC MICE