Antagonistic Functions of USAG-1 and RUNX2 during Tooth Development.

Antagonistic Functions of USAG-1 and RUNX2 during Tooth Development.

Blog Article

Supernumerary teeth and tooth agenesis are common morphological anomalies in humans.We previously obtained evidence that supernumerary maxillary incisors form as a result of the successive development of the rudimentary maxillary incisor tooth germ in Usag-1 null mice.The development of tooth germs is arrested in Runx2 null mice, and such mice also exhibit lingual epithelial buds associated with the bovi-shield gold fp 5 l5 upper molars and incisors.The aim of this study is to investigate the potential crosstalk between Usag-1 and Runx2 during tooth development.

In the present study, three interesting phenomena were observed in double null Usag-1-/-/Runx2-/- mice: the prevalence of supernumerary teeth was lower than in Usag-1 null mice; tooth development progressed further compared than in Runx2 null mice; and the frequency of molar lingual buds was lower than in Runx2 null mice.Therefore, we suggest that RUNX2 and USAG-1 act in an antagonistic manner.The lingual bud was completely filled with odontogenic epithelial Sox2-positive cells in the Usag-1+/+/Runx2-/- mice, whereas almost no odontogenic epithelial Sox2-positive cells contributed to supernumerary tooth formation in the rudimentary maxillary incisors of the Usag-1-/-/Runx2+/+ mice.Our findings suggest that RUNX2 directly or indirectly prevents the differentiation and/or proliferation of odontogenic epithelial Sox2-positive cells.

We hypothesize that RUNX2 inhibits the bone morphogenetic protein (BMP) and/or Wnt signaling pathways regulated by USAG-1, whereas RUNX2 expression echofix spring reverb is induced by BMP signaling independently of USAG-1.