2025 Volume 67 Issue 3 Pages 95-102
Periodontal tissue is composed of epithelial-derived and mesenchymal-derived tissues, including alveolar bone, periodontal ligament, cementum, and gingival epithelium. Due to the complex structure composed of epithelial and mesenchymal tissues, a deep understanding of the characteristics of this tissue is necessary for elucidating the pathophysiological mechanisms underlying the development of periodontal diseases and for developing effective methods for preventing and treating periodontal diseases.
Using laser microdissection and microarray analysis, we identified factors that are specifically expressed in the junctional epithelium. For example, peptides were specifically expressed in the junctional epithelium. Furthermore, neutrophils were present only in the junctional epithelium and were continuously prepared to respond to infection. On the other hand, the gingival epithelium also showed expression of factors such as tumor necrosis factor (TNF)-α, which are involved in periodontal tissue destruction, suggesting a dual role of the gingival epithelium of 'defense' and 'destruction.'
Periodontal ligament stem cells present in the periodontal ligament possess multipotent differentiation capability and are expected to be a useful starting material for periodontal tissue regeneration. We cultured periodontal ligament stem cells in spheroid culture (3D culture) and investigated their application in tissue regeneration. As compared to monolayer-cultured periodontal ligament stem cells, periodontal ligament stem cell spheroids showed significantly increased expressions of stem cell markers such as OCT4 and NANOG. Furthermore, when the culture was carried out under osteoblast differentiation-inducing conditions, enhanced calcification was also observed. When periodontal ligament stem cell spheroids were transplanted into cranial bone or periodontal tissue defect models, the amount of tissue regeneration was significantly greater than that noted after transplantation of cells from the monolayer culture group. These findings suggest that periodontal ligament stem cells and spheroid culture technology are useful for tissue regeneration.
