scholarly journals Expression of Axin2 indicates a role for canonical Wnt signaling in development of the crown and root during pre- and postnatal tooth development

2009 ◽  
pp. NA-NA ◽  
Author(s):  
Mahtab Lohi ◽  
Abigail S. Tucker ◽  
Paul T. Sharpe
Keyword(s):  
Wnt Signaling ◽  
Tooth Development ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

Wnt Production in Dental Epithelium Is Crucial for Tooth Differentiation

2019 ◽  
Vol 98 (5) ◽  
pp. 580-588 ◽  
Author(s):  
Y. Xiong ◽  
Y. Fang ◽  
Y. Qian ◽  
Y. Liu ◽  
X. Yang ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Tooth Development ◽  
Wnt Signaling Pathway ◽  
Conditional Knockout ◽  
Canonical Wnt Signaling ◽  
Odontoblast Differentiation ◽  
Wnt Ligands ◽  
Dental Epithelium ◽  
Canonical Wnt

The Wnt ligands display varied spatiotemporal expression in the epithelium and mesenchyme in the developing tooth. Thus far, the actions of these differentially expressed Wnt ligands on tooth development are not clear. Shh expression specifies the odontogenic epithelium during initiation and is consistently restricted to the dental epithelium during tooth development. In this study, we inactivate Wntless ( Wls), the key regulator for Wnt trafficking, by Shh-Cre to investigate how the Wnt ligands produced in the dental epithelium lineage act on tooth development. We find that conditional knockout of Wls by Shh-Cre leads to defective ameloblast and odontoblast differentiation. WlsShh-Cre teeth display reduced canonical Wnt signaling activity in the inner enamel epithelium and the underlying mesenchyme at the early bell stage, as exhibited by target gene expression and BAT-gal staining. The expression of Wnt5a and Wnt10b is not changed in WlsShh-Cre teeth. By contrast, Wnt10a expression is significantly increased in response to epithelial Wls deficiency. In addition, the expression of Hedgehog signaling pathway components Shh, Gli1, and Patched1 was greatly decreased in WlsShh-Cre teeth. Epithelial Wls loss of function in Shh lineage also leads to aberrant cell proliferation in dental epithelium and mesenchyme at embryonic day 16.5; however, the cell apoptosis is unaffected. Moreover, we find that Decorin and Col1a1, the key markers for odontoblast differentiation that are downregulated in WlsShh-Cre teeth, act as direct downstream targets of the canonical Wnt signaling pathway by chromatin immunoprecipitation analysis. Additionally, Decorin and Col1a1 expression can be increased by lithium chloride (LiCl) treatment in the in vitro tooth explants. Taken together, our results suggest that the spatial expression of Wnt ligands within the dental epithelial lineage regulates the differentiation of tooth structures in later stages.

Sign in / Sign up

Export Citation Format

Share Document