Axin2+-Mesenchymal PDL Cells, Instead of K14+ Epithelial Cells, Play a Key Role in Rapid Cementum Growth.
Academic Article
Overview
Research
Identity
Additional Document Info
View All
Overview
abstract
To date, attempts to regenerate functional periodontal tissues (including cementum) are largely unsuccessful due to a lack of full understanding about the cellular origin (epithelial or mesenchymal cells) essential for root cementum growth. To address this issue, we first identified a rapid cementum growth window from the ages of postnatal day 28 (P28) to P56. Next, we showed that expression patterns of Axin2 and -catenin within cementum-forming periodontal ligament (PDL) cells are negatively associated with rapid cementum growth. Furthermore, cell lineage tracing studies revealed that the Axin2+-mesenchymal PDL cells and their progeny rapidly expand and directly contribute to postnatal acellular and cellular cementum growth. In contrast, the number of K14+ epithelial cells, which were initially active at early stages of development, was reduced during rapid cementum formation from P28 to P56. The in vivo cell ablation of these Axin2+ cells using Axin2CreERT2/+; R26RDTA/+ mice led to severe cementum hypoplasia, whereas constitutive activation of -catenin in the Axin2+ cells resulted in an acceleration in cellular cementogenesis plus a transition from acellular cementum to cellular cementum. Thus, we conclude that Axin2+-mesenchymal PDL cells, instead of K14+ epithelial cells, significantly contribute to rapid cementum growth.
