Abstract
Purpose: Smad4 is a central mediator for transforming growth factor-<TEX>${\beta}$</TEX>/bone morphogenetic protein (<TEX>$TGF-{\beta}/BMP$</TEX>) signals, which are involved in regulating cranial neural crest cell formation, migration, proliferation, and fate determination. Accumulated evidences indicate that <TEX>$TGF-{\beta}/BMP$</TEX> signaling plays key roles in the early tooth morphogenesis. However, their roles in the late tooth formation, such as cellular differentiation and matrix formation are not clearly understood. The objective of this study is to understand the roles of Smad4 in vivo during enamel and dentin formation through tissue-specific inactivation of Smad4. Methods: We generated and analyzed mice with dental epithelium-specific inactivation of the Smad4 gene (K14-Cre:<TEX>$Smad4^{fl/fl}$</TEX>) and dental mesenchyme-specific inactivation of Smad4 gene (Osr2Ires-Cre:<TEX>$Smad4^{fl/fl}$</TEX>). Results: In the tooth germs of K14-Cre:<TEX>$Smad4^{fl/fl}$</TEX>, ameloblast differentiation was not detectable in inner enamel epithelial cells, however, dentin-like structure was formed in dental mesenchymal cells. In the tooth germs of Osr2Ires-Cre:<TEX>$Smad4^{fl/fl}$</TEX> mice, ameloblasts were normally differentiated from inner enamel epithelial cells. Interestingly, we found that bone-like structures, with cellular inclusion, were formed in the dentin region of Osr2Ires-Cre:<TEX>$Smad4^{fl/fl}$</TEX> mice. Conclusion: Taken together, our study demonstrates that Smad4 plays a crucial role in regulating ameloblast and odontoblast differentiation, as well as in regulating epithelial-mesenchymal interactions during tooth development.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: The Journal Of Korean Association of Maxillofacial Plastic and Reconstructive Surgeons
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
