State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Cell Prolif. 2022 Dec;55(12):e13330. doi: 10.1111/cpr.13330. Epub 2022 Aug 31.
Nucleotide oligomerization domain receptor 1 (NOD1) mediates host recognition of pathogenic bacteria in periodontium. However, the specific role of NOD1 in regulating osteogenesis is unclear. Therefore, this study focused on the activation status of NOD1 in periodontitis and its effect on the osteogenic capacity of human periodontal ligament stem cells (hPDLSCs) as well as the underlying mechanism.
Histological staining and Western blot were utilized to assess NOD1 expression in the periodontium of people with or without periodontitis. HPDLSCs were cultured under NOD1 agonist or antagonist treatment. Q-PCR and Western blot were employed to assess the expression of osteogenic marker genes and proteins. Alizarin red staining and alkaline phosphatase staining were used to determine the osteogenic capability of hPDLSCs. The activation of downstream signalling was determined and specific inhibitors were utilized to confirm the signalling pathway in NOD1-regulated osteogenesis.
NOD1 expression is significantly elevated in periodontitis. With NOD1 activated by particular agonist tri-DAP, the osteogenic potential of hPDLSCs was impaired. NOD1 antagonist co-incubation partially restored the decreased osteogenesis in hPDLSCs. P38/MAPK was phosphorylated in tri-DAP-induced NOD1 activation. The inhibitor of p38 rescued the suppression of osteogenesis induced by tri-DAP in hPDLSCs.
Our study revealed the expression status of NOD1 in periodontitis. Its activation greatly decreased the osteogenic capacity of hPDLSCs which was mediated by the phosphorylation of p38 downstream signalling.
核苷酸寡聚化结构域受体 1（NOD1）介导宿主对牙周致病菌的识别。然而，NOD1 调节成骨作用的具体机制尚不清楚。因此，本研究聚焦于牙周炎中 NOD1 的激活状态及其对人牙周膜干细胞（hPDLSCs）成骨能力的影响，并探讨其潜在机制。
采用组织学染色和 Western blot 检测牙周炎患者和牙周健康者牙周组织中 NOD1 的表达。用 NOD1 激动剂或拮抗剂处理 hPDLSCs。采用 Q-PCR 和 Western blot 检测成骨标志物基因和蛋白的表达。茜素红染色和碱性磷酸酶染色检测 hPDLSCs 的成骨能力。检测下游信号通路的激活情况，并使用特定抑制剂证实 NOD1 调节成骨过程中的信号通路。
NOD1 的表达在牙周炎中显著上调。用特定激动剂三-DAP 激活 NOD1 后，hPDLSCs 的成骨潜能受损。用 NOD1 拮抗剂共孵育可部分恢复 hPDLSCs 中降低的成骨作用。三-DAP 诱导的 NOD1 激活导致 p38/MAPK 磷酸化。p38 的抑制剂挽救了三-DAP 诱导的 hPDLSCs 中成骨作用的抑制。
本研究揭示了 NOD1 在牙周炎中的表达状态。其激活通过下游 p38 信号通路的磷酸化极大地降低了 hPDLSCs 的成骨能力。
