ABSTRACT
@#Periodontal ligament stem cells (PDLSCs) have the potential for multidirectional differentiation and are the preferred seed cells for periodontal tissue regeneration. In recent years, a large number of studies have confirmed that PDLSCs also possess broad immunomodulatory properties. Therefore, in-depth exploration of their specific molecular mechanisms is of great significance for the treatment of periodontitis. The aim of this paper is to summarize the research progress on the regulation of PDLSCs on various immune cells and the effect of the inflammatory environment on the immune characteristics of PDLSCs to provide an important theoretical basis for the allotransplantation of PDLSCs and improve the therapeutic effect of periodontal tissue regeneration. Studies have shown that PDLSCs possess a certain degree of immunosuppressive effect on both innate and acquired immune cells, and inflammatory stimulation may lead to the impairment of the immunoregulatory properties of PDLSCs. However, current studies are mainly limited to in vitro cell tests and lack in-depth studies on the immunomodulatory effects of PDLSCs in vivo. In vivo studies based on cell lineage tracing and conditional gene knockout technology may become the main directions for future research.
ABSTRACT
@#As a highly conserved signal pathway in evolution, the WNT signaling pathway plays an essential role in periodontium growth, development and injury repair. The Axin-associated protein Axin2 is a direct effector molecule of the WNT signaling pathway and labels WNT-responsive cells well. Studies have shown that Axin2-positive (Axin2+) cells in the periodontium have the potential for self-renewal, replication and multidirectional differentiation. This article reviews the temporal and spatial distribution of Axin2+ cells in periodontal tissue development and the role and regulatory mechanism of Axin2+ cells in periodontal tissue development, regeneration and tissue remodeling to provide new ideas for periodontal tissue regeneration. The literature review showed that Axin2+ cells were the main cell source of periodontium development, and Axin2+ cells played essential roles in tooth extraction socket healing, implant osseointegration, periodontal tissue remodeling and junctional epithelium regeneration. The function of Axin2+ cells was positively regulated by the canonical WNT signaling pathway. However, the regulatory mechanisms of other signaling pathways on Axin2+ cells remain to be elucidated.
ABSTRACT
@#Osteocytes, which develop from osteoblasts, are recognized as the main cells embedded in mature bone tissue. The traditional notion is that osteocytes exclusively play a structural role, however, with the development of related research in recent years, the role of osteocytes in bone metabolism has been explored. Periodontitis is a chronic inflammatory disease initiated by plaque biofilm, and is the main cause of adult tooth loss. Clinically, periodontitis primarily manifests as attachment loss, bleeding on probing and other symptoms. Alveolar bone resorption is the most characteristic pathological change. Current research demonstrated that osteocytes sense mechanical stress, participate in bone remodeling, regulate mineral balance, and participate in endocrine function. Thus, these cells play an important role in bone homeostasis and systemic metabolic balance. Osteocytes are actively involved in the development of periodontitis through the high expression of receptor activator of nuclear factor kappa B ligand (RANKL), secretion of sclerostin, and effect on apoptosis, senescence and autophagy. In the future, the detection of bone cell metabolism-related products will have certain application prospects for the clinical evaluation of periodontitis prevention and treatment. Therefore, this paper reviewed the role of osteocytes in bone homeostasis and the relationship between osteocytes and periodontitis, to provide new ideas for the prevention and treatment of periodontitis.