TNF-α and OSX mRNA of Salivary Small Extracellular Vesicles in Periodontitis: A Pilot Study

This cross-sectional pilot study explored extracellular vesicle (EV)-derived gene expression of markers for bone turnover and pro-inflammatory cytokines in periodontal disease. Whole unstimulated saliva was collected from 52 participants (18 healthy, 13 gingivitis, and 21 stages III/IV periodontitis), from which salivary small extracellular vesicles (sEVs) were enriched using the size-exclusion chromatography method, and characterized by morphology, EV-protein, and size distribution, using transmission electron microscopy (TEM), enzyme-linked immunosorbent assay (ELISA), and Nanoparticle Tracking Analysis (NTA), respectively. Bone turnover markers and pro-inflammatory cytokines in salivary sEVs were evaluated using reverse transcription PCR. Salivary sEVs morphology, mode, size distribution, and particle concentration were comparable between healthy, gingivitis, and periodontitis patients. The CD9+ subpopulation was significantly higher in periodontitis-derived salivary sEVs compared with healthy. The detection of sEVs mRNA for osterix and tumor necrosis factor-alpha was significantly decreased and increased, respectively, in periodontitis compared with healthy controls, with good discriminatory power for periodontitis diagnosis (area under the curve >0.72). This pilot study demonstrated that salivary sEVs mRNAs may serve as a potential noninvasive biomarker source for periodontitis diagnosis.