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Wnt10a regulates dentin sialophosphoprotein mRNA expression and possibly links odontoblast differentiation and tooth morphogenesis

Authors

  • Takashi Yamashiro,

    Corresponding author
    1. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Dentistry Osaka University, 1-8 Yamadaoka, Suita Osaka 565-0871, Japan
    2. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Medicine and Dentistry Okayama University, 2-5-1 Shikata-cho Okayama 700-8558, Japan
      Tel: +81 86 2356690
      Fax: +81 86 2356694
    3. Developmental Biology Programme, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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  • Li Zheng,

    1. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Medicine and Dentistry Okayama University, 2-5-1 Shikata-cho Okayama 700-8558, Japan
      Tel: +81 86 2356690
      Fax: +81 86 2356694
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  • Yuko Shitaku,

    1. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Dentistry Osaka University, 1-8 Yamadaoka, Suita Osaka 565-0871, Japan
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  • Masahiro Saito,

    1. Department of Oral Medicine, Division of Operative Dentistry and Endodontics, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan
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  • Takanori Tsubakimoto,

    1. Department of Oral Medicine, Division of Operative Dentistry and Endodontics, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan
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  • Kenji Takada,

    1. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Dentistry Osaka University, 1-8 Yamadaoka, Suita Osaka 565-0871, Japan
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  • Teruko Takano-Yamamoto,

    1. Department of Orthodontics and Dentofacial Orthopedics Graduate School of Medicine and Dentistry Okayama University, 2-5-1 Shikata-cho Okayama 700-8558, Japan
      Tel: +81 86 2356690
      Fax: +81 86 2356694
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  • Irma Thesleff

    1. Developmental Biology Programme, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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✉ E-mail: yamataka@md.okayama-u.ac.jp

Abstract

Abstract We have explored the role of Wnt signaling in dentinogenesis of mouse molar teeth. We found that Wnt10a was specifically associated with the differentiation of odontoblasts and that it showed striking colocalization with dentin sialophosphoprotein (Dspp) expression in secretory odontoblasts. Dspp is a tooth specific non-collagenous matrix protein and regulates dentin mineralization. Transient overexpression of Wnt10 in C3H10T1/2, a pluripotent fibroblast cell line induced Dspp mRNA. Interestingly, this induction occurred only when transfected cells were cultured on Matrigel basement membrane extracts. These findings indicated that Wnt10a is an upstream regulatory molecule for Dspp expression, and that cell–matrix interaction is essential for induction of Dspp expression. Furthermore, Wnt10a was specifically expressed in the epithelial signaling centers regulating tooth development, the primary and secondary enamel knots. The spatial and temporal distribution of Wnt10a mRNA demonstrated that the expression shifts from the secondary enamel knots, to the underlying preodontoblasts in the tips of future cusps. The expression patterns and overexpression studies together indicate that Wnt10a is a key molecule for dentinogenesis and that it is associated with the cell–matrix interactions regulating odontoblast differentiation. We conclude that Wnt10a may link the differentiation of odontoblasts and cusp morphogenesis.

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