Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Sci Rep. 2022 Aug 20;12(1):14239. doi: 10.1038/s41598-022-18412-4.
Dysbiosis of the oral microbiota plays an important role in the progression of periodontitis, which is characterized by chronic inflammation and alveolar bone loss, and associated with systemic diseases. Bacterial extracellular vesicles (EVs) contain various bioactive molecules and show diverse effects on host environments depending on the bacterial species. Recently, we reported that EVs derived from Filifactor alocis, a Gram-positive periodontal pathogen, had osteoclastogenic activity. In the present study, we analysed the osteoclastogenic potency and immunostimulatory activity of EVs derived from the Gram-negative periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia, the oral commensal bacterium Streptococcus oralis, and the gut probiotic strain Lactobacillus reuteri. Bacterial EVs were purified by density gradient ultracentrifugation using OptiPrep (iodixanol) reagent. EVs from P. gingivalis, T. forsythia, and S. oralis increased osteoclast differentiation and osteoclstogenic cytokine expression in osteoclast precursors, whereas EVs from L. reuteri did not. EVs from P. gingivalis, T. forsythia, and S. oralis preferentially activated Toll-like receptor 2 (TLR2) rather than TLR4 or TLR9, and induced osteoclastogenesis mainly through TLR2. The osteoclastogenic effects of EVs from P. gingivalis and T. forsythia were reduced by both lipoprotein lipase and polymyxin B, an inhibitor of lipopolysaccharide (LPS), while the osteoclastogenic effects of EVs from S. oralis were reduced by lipoprotein lipase alone. These results demonstrate that EVs from periodontal pathogens and oral commensal have osteoclastogenic activity through TLR2 activation by lipoproteins and/or LPS.
口腔微生物群落失调在牙周炎的进展中起着重要作用，牙周炎的特征是慢性炎症和牙槽骨丧失，并与全身性疾病有关。细菌细胞外囊泡 (EV) 包含各种生物活性分子，并根据细菌种类对宿主环境表现出不同的影响。最近，我们报道了源自革兰氏阳性牙周病原体 Filifactor alocis 的 EV 具有破骨细胞生成活性。在本研究中，我们分析了源自革兰氏阴性牙周病原体牙龈卟啉单胞菌和福赛斯坦纳菌、口腔共生菌链球菌和肠道益生菌乳杆菌的 EV 的破骨细胞生成能力和免疫刺激活性。使用 OptiPrep（碘克沙醇）试剂通过密度梯度超速离心纯化细菌 EV。来自 P. gingivalis、T. forsythia 和 S. oralis 的 EV 增加了破骨细胞前体中的破骨细胞分化和破骨细胞生成细胞因子表达，而来自 L. reuteri 的 EV 则没有。来自 P. gingivalis、T. forsythia 和 S. oralis 的 EV 优先激活 Toll 样受体 2 (TLR2) 而不是 TLR4 或 TLR9，并主要通过 TLR2 诱导破骨细胞生成。脂蛋白脂肪酶和多粘菌素 B（脂多糖 LPS 的抑制剂）降低了来自 P. gingivalis 和 T. forsythia 的 EV 的破骨细胞生成作用，而来自 S. oralis 的 EV 的破骨细胞生成作用仅被脂蛋白脂肪酶降低。这些结果表明，牙周病原体和口腔共生菌的 EV 通过脂蛋白和/或 LPS 激活 TLR2 具有破骨细胞生成活性。
