LAUSR

AIM To examine the immunomodulatory effect of exosomes originating from gingival mesenchymal stem cells (GMSC-Exo) on periodontal bone regeneration and its role in the regulation of the Nuclear factor-κB (NF-κB) and Wnt/β-catenin pathways in the periodontal inflammatory microenvironment. MATERIALS AND METHODS Firstly, the periodontal ligament stem cells (PDLSCs) were treated with GMSC-Exo or Porphyromonas gingivalis-derived lipopolysaccharide (P.g-LPS) in vitro. qRT-PCR and western blot were conducted to detect the expressions of osteogenic differentiation-related factors in cells. Further, PDLSCs were treated with P.g-LPS or inhibitors. The expression of NF-κB pathway-related factors as well as Wnt/β-catenin pathway-related factors were detected by qRT-PCR and western blot. RESULTS GMSC-Exo treatment promoted the expression of osteogenic differentiation-related factors within PDLSCs in both normal and inflammatory environments. Further investigations showed that GMSC-Exo could also inhibit the P.g-LPS-induced activation of the NF-κB pathway, leading to the upregulation of the Wnt/β-catenin pathway. When the Wnt/β-catenin signaling was blocked, the inhibitory effect of GMSC-Exo on the NF-κB pathway was abolished. CONCLUSION GMSC-Exo could promote the osteogenic differentiation of PDLSCs. There could be mutually exclusive regulatory roles between the NF-κB and Wnt/β-catenin signaling pathways in a periodontal inflammatory environment. GMSC-Exo exhibited an effective cross-regulation ability for both two pathways.