title: Wnt10a regulates dentin sialophosphoprotein mRNA expression and possibly links odontoblast differentiation and tooth morphogenesis.
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.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita Osaka 565-0871, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamashiro
authors.forename: Li
authors.initials: L
authors.lastname: Zheng
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shitaku
authors.forename: Masahiro
authors.initials: M
authors.lastname: Saito
authors.forename: Takanori
authors.initials: T
authors.lastname: Tsubakimoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Takada
authors.forename: Teruko
authors.initials: T
authors.lastname: Takano-Yamamoto
authors.forename: Irma
authors.initials: I
authors.lastname: Thesleff
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002462:Cell Membrane; D003094:Collagen / Q000378:metabolism; D004338:Drug Combinations; D004847:Epithelial Cells / Q000378:metabolism; D016326:Extracellular Matrix Proteins; D017403:In Situ Hybridization; D007797:Laminin / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009804:Odontoblasts / Q000166:cytology* / Q000378:metabolism; D010750:Phosphoproteins; D039904:Pluripotent Stem Cells / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins; D015398:Signal Transduction; D014070:Tooth / Q000196:embryology* / Q000378:metabolism; D051153:Wnt Proteins / Q000502:physiology*; D000099311:Dentin Sialophosphoprotein
chemical_list: D003094:Collagen; D004338:Drug Combinations; D016326:Extracellular Matrix Proteins; D007797:Laminin; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D011498:Protein Precursors; D011509:Proteoglycans; D012333:RNA, Messenger; D012795:Sialoglycoproteins; D051153:Wnt Proteins; D000099311:Dentin Sialophosphoprotein; C484143:Wnt10a protein, mouse; C059485:matrigel