Does a novel signal center exsist at outer enamel epithelium in incisor germ?

• Project/Area Number: 26670805
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Morphological basic dentistry
• Research Institution: Iwate Medical University
• Principal Investigator: Harada Hidemitsu 岩手医科大学, 歯学部, 教授 (70271210)
• Co-Investigator(Kenkyū-buntansha): Fujiwara Naoki 岩手医科大学, 歯学部, 准教授 (20190100) ; Otsu Keishi 岩手医科大学, 歯学部, 講師 (60509066) ; Kumakami Mika 岩手医科大学, 歯学部, 常任研究員 (30710826)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: エナメル上皮幹細胞 / 切歯 / シグナルセンター / 外エナメル上皮 / 発生 / マウス切歯 / 歯の発生 / 切歯歯胚

Outline of Final Research Achievements

In order to examine the mechanisms of apical bud (dental epithelial niche) development in a continuously growing mouse incisor, we had observed incisor germ growth using live cell imaging. We had found a special cell population (dental epithelial bulge of outer enamel epithelium: DEB of OEE), which supply some cells toward incisal end and distal end, in the outer enamel epithelium of labial dental epithelium. First, we attempted to analyze the detail morphology of a developing incisor germ using 3D imaging of sheet laser microscopy and CK14cre/Rosa26-tdTomato. The morphology is similar to a 90 degree rotated molar tooth germ, and exhibit a elongated labial dental epithelium. Next, we observed cell cycle using Fucci mouse and glycogen deposit by immunohistochemistry in DEB of OEE. The results showed that some cells in DEB of OEE showed cessation at G0 and accumulated glycogen. Considering with these results, we presumed that DEB of OEE is an important area for production of apical bud.

Research Products

• [Journal Article] Evidence for bicarbonate secretion by ameloblasts in a novel cellular model. (2016)
  • Author(s): Bori, E, Guo J, Rácz R, Burghardt B, Földes A, Kerémi B, Harada H, Steward MC, DenBesten P, Antonius LJJ Bronckers ALJJ, Varga G.
  • Journal Title: J Dent Res Volume: 95 Issue: 5 Pages: 588-596
  • DOI: 10.1177/0022034515625939
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Sox2 contributes to tooth development via Wnt signaling. (2016)
  • Author(s): Lee MJ, Kim EJ, Otsu K, Harada H, Jung HS
  • Journal Title: Cell Tissue Res Volume: 0 Pages: 0-0
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The glycogen metabolism via Akt signaling is important for the secretion of enamel matrix in tooth development (2016)
  • Author(s): Ida-Yonemochi H, Otsu K, Ohshima H, Harada H
  • Journal Title: Mech Dev Volume: 139 Pages: 18-30
  • DOI: 10.1016/j.mod.2016.01.002
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] The enamel knot-like structure is eternally maintained in the apical bud of postnatal mouse incisors (2015)
  • Author(s): Chihiro Nakatomi, Mitsushiro Nakatomi, Kan Saito, Hidemitsu Harada, Hayato Ohshima
  • Journal Title: Archives of Oral Biology Volume: 0 Pages: 0-0
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Live imaging to elucidate cell dynamics in tooth organogenesis and regeneration. (2015)
  • Author(s): Harada H, Kumakami-Sakano M, Fujiwara N, Otsu K.
  • Journal Title: Journal of Oral Biosciences Volume: 57 Issue: 2 Pages: 65-68
  • DOI: 10.1016/j.job.2015.02.005
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Regenerated teeth: the future of tooth replacement. An update. (2015)
  • Author(s): Thimios A Mitsiadis and Hidemitsu Harada.
  • Journal Title: Regenerative Medicine Volume: 10 Issue: 1 Pages: 5-8
  • DOI: 10.2217/rme.14.78
• [Presentation] Aktシグナルがグルコース代謝を促進しエナメル芽細胞分化を誘導する (2015)
  • Author(s): 依田浩子、大津圭史、大島勇人、原田英光
  • Organizer: 第38回日本分子生物学会・第88回日本生化学会合同大会
  • Place of Presentation: 神戸
  • Year and Date: 2015-12-01
• [Presentation] 歯根発生メカニズムの新規仮説と歯根形態異常 (2015)
  • Author(s): 熊上 深香、大津 圭史、藤原 尚樹、原田 英光
  • Organizer: 第56回 歯科基礎医学会学術大会
  • Place of Presentation: 福岡市
  • Year and Date: 2015-09-25 – 2015-09-27
  • Invited
• [Presentation] 生後マウス切歯apical budにエナメル結節様構造が恒久的に維持されている (2015)
  • Author(s): 中富 千尋、中富 満城、齋藤 幹、原田 英光、大島 勇人
  • Organizer: 第56回 歯科基礎医学会学術大会
  • Place of Presentation: 福岡市
  • Year and Date: 2015-09-25 – 2015-09-27
• [Presentation] イメージングから考える歯の形態形成機構の新規視点 (2015)
  • Author(s): 原田英光, 熊上深香，大津圭史, 藤原尚樹
  • Organizer: 第57回歯科基礎医学会
  • Place of Presentation: 新潟
  • Year and Date: 2015-09-11
  • Invited
• [Presentation] Regulation of stemness of dental epithelial stem cells by Rho signaling (2015)
  • Author(s): Otsu K, Oku Y, Nishiya N. Fujiwara N, Harada H
  • Organizer: ISSCR 2015 Annual Meeting
  • Place of Presentation: Stockholm, Sweden
  • Year and Date: 2015-06-25
  • Int'l Joint Research
• [Presentation] The role of TRPM7 channels in tooth mineralization (2015)
  • Author(s): Oka K., Ogata K., Kira-Tatsuoka M., Tumuraya T., Fukushima H., Okamoto F., Osaki M., Harada H., Matsushita M., Okabe K
  • Organizer: 4thTripartite Conference on Tooth and Bone; Development & Regeneration.
  • Place of Presentation: Narita
  • Year and Date: 2015-06-12
  • Int'l Joint Research
• [Presentation] Role of glucose metabolism during ameloblast differentiation (2015)
  • Author(s): Ida-Yonemochi H., Harada H., Ohshima H
  • Organizer: The 4th Tripartite Conference on Tooth and Bone. Jun. 14, 2015
  • Place of Presentation: Narita
  • Year and Date: 2015-06-12
  • Int'l Joint Research