The bidirectional relationship between periodontitis and diabetes: New prospects for stem cell-derived exosomes

Small Extracellular Vesicles Laden Oxygen-Releasing Thermosensitive Hydrogel for Enhanced Antibacterial Therapy against Anaerobe-Induced Periodontitis Alveolar Bone Defect

Periodontitis is a bacterially induced chronic destructive inflammatory disease that leads to irreversible destruction of the tooth supporting structure, including connective tissue destruction, bone resorption, and even tooth loss. Until now, there has been no effective treatment to repair inflammatory bone loss in periodontitis. Recently, small extracellular vesicles (sEVs) emerged as the essential paracrine factors of mesenchymal stem cells (MSCs) that mediated tissue regeneration. However, limitations of antimicrobial activity associated with the use of sEVs have led to the urgency of new alternative strategies. Currently, we investigated the potential of a biocompatible oxygen-releasing thermosensitive hydrogel laded with sEVs secreted by bone marrow MSCs (BMMSCs) for the alveolar bone defect in periodontitis. The hydrogel composed of different polymers such as chitosan (CS), poloxamer 407 (P407), and cross-linked hyaluronic acid (c-HA) conglomerating is a kind of nanoporous structure material. Then, the gel matrix further encapsulated sEVs and calcium peroxide nanoparticles to realize the control of sEVs and oxygen release. Furthermore, ascorbic acid was added to achieve the REDOX equilibrium and acid-base equilibrium. The experiments in vivo and in vitro proved its good biocompatibility and effectively inhibited the growth of the periodontal main anaerobe, relieved periodontal pocket anaerobic infections, and promoted the periodontal defect regeneration. Therefore, this finding demonstrated that it was a promising approach for combating anaerobic pathogens with enhanced and selective properties in periodontal diseases, even in other bacteria-induced infections, for future clinical application.

Periodontal Ligament Stem Cell Exosomes Key to Regulate Periodontal Regeneration by miR-31-5p in Mice Model

Introduction

Periodontitis is a chronic inflammatory disease that causes alveolar bone loss. Diabetes is one of the most important factors contributing to periodontitis. Exosomes derived from mesenchymal stem cells (MSCs-Exo) have been reported to promote bone regeneration. This study aimed to examine the function and mechanism of exosomes derived from periodontal ligament stem cells (PDLSCs-Exo) in regulating periodontal regeneration in diabetic periodontitis.

Methods

Exosomes derived from normal-glucose-cultured PDLSCs (NG-PDLSCs-Exo) and high-glucose-preconditioned PDLSCs (HG-PDLSCs-Exo) were used. Their effects on RAW264.7 cells were investigated by TRAP staining and quantitative real time-polymerase chain reaction (qRT-PCR). The role of exosomal miR-31-5p in osteoclast differentiation was tested using qRT-PCR, double luciferase analysis, and Western blotting. We investigated the effects of these two types of PDLSCs-Exo on alveolar bone loss in vivo in mice with experimental periodontitis.

Results

PDLSCs-Exo were transferred to RAW264.7, and HG-PDLSCs-Exo inhibited osteoclast formation to a lesser extent than NG-PDLSCs-Exo. Further studies revealed the effect of PDLSCs-Exo on osteoclastogenesis via the miR-31-5p/eNOS signaling pathway. In mice with experimental periodontitis, PDLSCs-Exo reduced alveolar bone destruction and decreased the number of osteoclasts on the alveolar bone surface.

Conclusion

Our results suggest that exosomal miR-31-5p derived from PDLSCs regulates alveolar bone regeneration by targeting eNOS.