TY - JOUR
T1 - Hepatocyte growth factor is involved in the morphogenesis of tooth germ in murine molars
AU - Tabata, Makoto J.
AU - Kim, Kenji
AU - Liu, Ji Guang
AU - Yamashita, Kazuo
AU - Matsumura, Tatsushi
AU - Kato, Joji
AU - Iwamoto, Masahiro
AU - Wakisaka, Satoshi
AU - Matsumoto, Kunio
AU - Nakamura, Toshikazu
AU - Kumegawa, Masayoshi
AU - Kurisu, Kojiro
PY - 1996/4/1
Y1 - 1996/4/1
N2 - The patterns 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 played by HGF in tooth development, HGF translation arrest by antisense phosphorothioate oligodeoxynucleotide (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 HGF mRNA. Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hand, antisense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layer 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 HGF combined with antisense ODN showed normal development, indicating that exogenous HGF rescued the explants from the abnormal structure caused by antisense ODN. The findings of a BrdU incorporation experiment suggested 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.
AB - The patterns 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 played by HGF in tooth development, HGF translation arrest by antisense phosphorothioate oligodeoxynucleotide (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 HGF mRNA. Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hand, antisense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layer 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 HGF combined with antisense ODN showed normal development, indicating that exogenous HGF rescued the explants from the abnormal structure caused by antisense ODN. The findings of a BrdU incorporation experiment suggested 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.
KW - Antisense oligodeoxynucleotide
KW - Hepatocyte growth factor (HGF/SF)
KW - Murine tooth development
KW - Organ culture of tooth germ
KW - c-met
UR - http://www.scopus.com/inward/record.url?scp=15844364380&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=15844364380&partnerID=8YFLogxK
M3 - Article
C2 - 8620851
AN - SCOPUS:15844364380
VL - 122
SP - 1243
EP - 1251
JO - Development (Cambridge)
JF - Development (Cambridge)
SN - 0950-1991
IS - 4
ER -