Department of Comprehensive Dentistry, College of Dentistry, Texas A&M University, Dallas, TX 75246, USA; West China School of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
Department of Comprehensive Dentistry, College of Dentistry, Texas A&M University, Dallas, TX 75246, USA.
Dev Cell. 2020 Sep 14;54(5):639-654.e6. doi: 10.1016/j.devcel.2020.06.006. Epub 2020 Jul 10.
Teeth are attached to alveolar bone by the periodontal ligament (PDL), which contains stem cells supporting tissue turnover. Here, we identified Gli1+ cells in adult mouse molar PDL as multi-potential stem cells (PDLSCs) giving rise to PDL, alveolar bone, and cementum. They support periodontium tissue turnover and injury repair. Gli1+ PDLSCs are surrounding the neurovascular bundle and more enriched in the apical region. Canonical Wnt signaling is essential for their activation. Alveolar bone osteocytes negatively regulate Gli1+ PDLSCs activity through sclerostin, a Wnt inhibitor. Blockage of sclerostin accelerates the PDLSCs lineage contribution rate in vivo. Sclerostin expression is modulated by physiological occlusal force. Removal of occlusal force upregulates sclerostin and inhibits PDLSCs activation. In summary, Gli1+ cells are the multipotential PDLSCs in vivo. Osteocytes provide negative feedback to PDLSCs and inhibit their activities through sclerostin. Physiological occlusal force indirectly regulates PDLSCs activities by fine-tuning this feedback loop.
牙齿通过牙周韧带 (PDL) 附着在牙槽骨上，牙周韧带包含支持组织更新的干细胞。在这里，我们鉴定出成年小鼠磨牙 PDL 中的 Gli1+ 细胞为多能干细胞 (PDLSCs)，可分化为 PDL、牙槽骨和牙骨质。它们支持牙周组织更新和损伤修复。Gli1+PDLSCs 环绕着神经血管束，在根尖区更为丰富。经典 Wnt 信号通路对其激活至关重要。成骨细胞通过 Wnt 抑制剂骨硬化素负向调节 Gli1+PDLSCs 的活性。阻断骨硬化素可加速体内 PDLSCs 谱系的贡献速率。骨硬化素的表达受生理咬合力的调节。去除咬合可上调骨硬化素并抑制 PDLSCs 的激活。综上所述，Gli1+细胞是体内的多能 PDLSCs。成骨细胞通过骨硬化素提供负反馈，并抑制 PDLSCs 的活性。生理咬合力通过微调这个反馈环间接调节 PDLSCs 的活性。
