Project/Area Number |
06454509
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
Morphological basic dentistry
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Research Institution | Osaka University |
Principal Investigator |
KURISU Kojiro Osaka University, Faculty of Dentistry, Professor, 歯学部, 教授 (50028346)
|
Co-Investigator(Kenkyū-buntansha) |
TABATA Makoto Osaka University, Faculty of Dentistry, Assistant, 歯学部, 助手 (20243248)
KATO Jouji Osaka University, Faculty of Dentistry, Assistant, 歯学部, 助手 (90243245)
IWAMOTO Tomomi Osaka University, Faculty of Dentistry, Instractor, 歯学部, 講師 (80203644)
WAKISAKA Satoshi Osaka University, Faculty of Dentistry, Associate Professor, 歯学部, 助教授 (40158598)
|
Project Period (FY) |
1994 – 1995
|
Project Status |
Completed (Fiscal Year 1995)
|
Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥5,800,000 (Direct Cost: ¥5,800,000)
|
Keywords | Tooth germ / Hepatocyte growth factor / Organ culture / Mouse / Morphogenesis / Development / Tissue differentiation / Antisense oligonucleotide / 免疫組織化学 |
Research Abstract |
The pattern of gene expression for hepatocyte growth factor (HGF) and its receptor, c-Met were revealed in the tooth germ of rat mandibular molars using RT-PCR.In situ hybridization demonstrated that the HGF gene was expressed only in the cells of the dental papilla of the tooth germ in vivo. The characteristic temporospatial distribution of HGF and c-Met during germ development was revealed using immunohistochemical studies in vivo. In order to demonstrate the functional role playd by HGF in tooth development, H translation arrest by antisense phosphorothioate oligonucleotide (ODN) was carried out in vitro. In the control experiment, explants of tooth germs from embryonic 14 day mice were cultured in a modification of Trowell's system under serum-free and chemically defined conditions for two weeks. Other explants were cultured with 15mer antisense or sense ODN targeted to the mRNA.Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hands, anti-sense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layr of dentin and dental papilla, appearing 'inside-out' compared to the control and sense-treated explants, although the cytodifferentiation of ameloblasts and odontoblasts was not inhibited. The explants treated with recombinant human combined with antisense ODN showed normal deve-lopment, indicating the exogenous HGF rescued the explants from the abnormal strcture caused by antisense ODN.The findings of a BrdU incorporation experiment suggest that the imbalance between the proliferation activity of the inner enamel epithelium and that of the dental papilla caused by HGF translation arrest results in the abnormal structure of the tooth germ. These results indicate that HGF is involved in the morphogenesis of the murine molar.
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