Identification of BMP-4 as a signal mediating secondary induction between epithelial and mesenchymal tissues during early tooth development.
Growth factor-mediated signaling has been implicated in the regulation of epithelial-mesenchymal interactions during organogenesis. Bone morphogenetic protein 4 (BMP-4), a member of the transforming growth factor beta superfamily, is expressed in the presumptive dental epithelium at the initiation of tooth development. Subsequently, epithelial signaling leads to mesenchymal induction of BMP-4 expression. To address the role of this factor, BMP-4-releasing agarose beads were added to dental mesenchyme in culture. These beads induced a translucent mesenchymal zone similar to that induced by dental epithelium. Moreover, three transcription factors (Msx-1, Msx-2, and Egr-1) whose expression is governed by epithelial signaling were induced in response to BMP-4. In addition, BMP-4 induced its own mesenchymal expression. These findings support the hypothesis that BMP-4 mediates epithelial-mesenchymal interactions during early tooth development.
Vainio
S
S
Department of Pedodontics and Orthodontics, University of Helsinki, Finland.
Karavanova
I
I
Jowett
A
A
Thesleff
I
I
D000818:Animals; D019485:Bone Morphogenetic Proteins; D002455:Cell Division; D004622:Embryo, Mammalian; D004848:Epithelium / Q000502:physiology; D015870:Gene Expression; D005801:Genes, Homeobox; D006133:Growth Substances / Q000378:metabolism*; D017403:In Situ Hybridization; D008648:Mesoderm / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009805:Odontogenesis / Q000187:drug effects; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism* / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction
D019485:Bone Morphogenetic Proteins; D006133:Growth Substances; D011506:Proteins; D011994:Recombinant Proteins