Essential role of osterix for tooth root but not crown dentin formation.
Essential role of osterix for tooth root but not crown dentin formation.
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DOI：
10.1002/jbmr.2391
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发表时间：
2015-04
期刊：
影响因子：
--
通讯作者：
Feng JQ
中科院分区：
文献类型：
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作者：
Zhang H;Jiang Y;Qin C;Liu Y;Ho SP;Feng JQ
Tooth is made of crown and root. It is widely believed that dentin formation in crown and root uses the same regulatory mechanism. However, identification of NFIC’s unique function in determining root but not crown dentin formation challenges the old thought. In searching for the target molecules downstream of NFIC, we unexpectedly found a sharp reduction of OSX (osterix), the key transcription factor in skeleton formation, in the Nfic knockout (KO) tooth root. We then demonstrated a dose-dependent increase of Osx in the odontoblast cell line due to a transient transfection of Nfic expression plasmid. Studies of global and conditional Osx KO mice revealed no apparent changes in the crown dentin tubules and dentin matrix. However, the OSX conditional KO mice (crossed to the 2.3 kb Col 1-Cre) displayed an increase in cell proliferation but great decreases in expressions of root dentin matrix proteins (DMP1 and DSPP), leading to an inhibition in odontoblast differentiation, and short thin root dentin with few dentin tubules. Compared to the Nfic KO tooth, which contains essentially no dentin tubules and remains in a “root-less” status at adult stages, the Osx cKO root phenotype had partially improved at the late stage, indicating that other factors can compensate for OSX function. Thus, we conclude that OSX, one of the key downstream molecules of NFIC, plays a critical role in root, but not crown, formation.
