Human Umbilical Cord Mesenchymal Stem Cells and their Extracellular Vesicles Modulate Pro- and Anti-inflammatory Cytokines in Ligature-induced Periodontitis.

BACKGROUND: Periodontitis is a chronic inflammatory condition that affects the tissues supporting the teeth, ultimately leading to tooth loss. Mesenchymal stem cells (MSCs) and their extracellular vesicles (EVs) play a crucial role in periodontitis by modulating the activities of gum cells and the immune system.

OBJECTIVE: To investigate the therapeutic potential of human umbilical cord mesenchymal stem cells (hUCSCs) and EVs in regulating the inflammatory response associated with periodontitis.

METHODS: hUCSCs were isolated, subjected to flow cytometry analysis of surface markers, and differentiated into adipocyte and osteocyte. hUCSC-EVs were isolated and characterized using flow cytometry and electron microscopy. A periodontitis animal model was established in 30 female C57Bl/6 mice. Experimental groups received hUCSCs or hUCSCs-EVs, or vehicles intravenously. Animals were monitored for 4 weeks, and the periodontal tissues were used to assess the effects of hUCSCs and hUCSCs-EVs on the expression of pro- (TNF-α, IFN-γ, and IL-17a) and anti-inflammatory cytokines (TGF-β, IL-10, and IL-4). The secretion of these cytokines by splenocytes was also evaluated using ELISA.

RESULTS: The levels of IL-17a, IFN-γ, and TNFα significantly reduced, while TGF-β and IL-10 significantly increased in the periodontal tissues of the hUCSC and hUCSCEVs-treated mice. The expression of TNF-α, IFN-γ, and IL-17a significantly decreased, while the production of IL-10 and TGF-β significantly increased in splenocytes from the hUCSC and EVs-treated mice.

CONCLUSION: hUCSCs and their EVs have the potential to attenuate the inflammatory response associated with periodontitis, possibly by downregulating pro-inflammatory cytokines and upregulating anti-inflammatory ones.