West China Journal of Stomatology ›› 2023, Vol. 41 ›› Issue (6): 662-670.doi: 10.7518/hxkq.2023.2023114

• Basic Research • Previous Articles     Next Articles

Morinda officinalis polysaccharides inhibit the expression and activity of NOD-like receptor thermal protein domain associated protein 3 in inflammatory periodontal ligament cells by upregulating silent information regulator sirtuin 1

Cai Hongxuan1(), Wang Zheng’an2, Zhang Zan1, Dai Jingyi1, Si Weixing1, Fu Qiya1, Yang Jingwen3(), Tian Yaguang4,5()   

  1. 1.School of Stomatology, Hainan Medical University, Haikou 570100, China
    2.Dept. of Stomatology, The First Affiliated Hospital of Hainan Medical College, Haikou 570100, China
    3.Dept. of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100080, China
    4.Dept. of Stomatology, Hainan Affiliated Hospital of Hainan Medical University, Haikou 570100, China
    5.Dept. of Stomatology, Hainan General Hospital, Haikou 570100, China
  • Received:2023-04-14 Revised:2023-09-27 Online:2023-12-01 Published:2023-11-27
  • Contact: Yang Jingwen,Tian Yaguang E-mail:Cai_hongxuan@163.com;jingwen.yang@foxmail.com;yaguangtian@163.com
  • Supported by:
    Key Research and Development Project of Hainan(ZDYF2021SHFZ229);Hainan Provincial Natural Science Foundation of China(822CXTD534);Correspondence: Tian Yaguang, E-mail: yaguangtian@163.com;Yang Jing-wen, E-mail: jingwen.yang@foxmail.com

Abstract:

Objective This study aims to investigate the effect of morinda officinalis polysaccharides (MOP) in inflammatory microenvironment on the expression of silent information regulator sirtuin 1 (SIRT1) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) in periodontal ligament cells. Methods Thirty rats were randomly divided into control group (n=6) and model group (n=24). The model group used orthodontic wire ligation to establish periodontitis, and six rats from each group were killed after 3 weeks. The successful modeling was confirmed by Micro-CT. The remaining rats in the model group were randomly divided into natural recovery group, normal saline (NS) group, and MOP group. In the MOP group, MOP [200 mg/(kg·3d), 50 µL for 4 weeks] was injected into the palatal side of the left maxillary first molar of the rats, while the NS group was injected with equal volume of NS. The natural recovery group did not undergo any treatment. The left maxilla tissues of the rats were collected, and pathological changes in perio-dontal ligament cells were observed by hematoxylin-eosin (HE) staining. The expression of SIRT1 and NLRP3 was detected by immunohistochemistry. Cultivate periodontal ligament fibroblasts in vitro and detect the effect of MOP on cell activity using CCK-8. The 4th generation cells were divided into control group, inflammation group (10 µg/mL lipopolysaccharide), and experimental group (5 µmol/L MOP, 5 µmol/L MOP+10 µg/mL lipopolysaccharide). The expression of SIRT1 and NLRP3 was detected by quantitative realtime polymerase chain reaction (qRT-PCR) and Western blot analyses. The acetylation of NLRP3 and the contents of interleukin (IL)-1β and IL-18 were detected by immunoprecipitation and enzyme-linked immunosorbent assay, respectively. Statistical analysis of data was conducted using Prism 9.0 software. Results In the vivo experiments, the expression of NLRP3 and SIRT1 in the MOP group decreased significantly compared with that in the natural recovery group and NS group, while the expression of SIRT1 increased (P<0.05) and inflammatory cell infiltration decreased. In the in vitro experiments, the expression of NLRP3 mRNA and protein in the inflammation group increased (P<0.05), while the expression of SIRT1 significantly decreased (P<0.01); MOP upregulated the expression of SIRT1 in inflammatory cells (P<0.05), reduced the expression of NLRP3 and its acetylation level significantly (P<0.05), suppressed the content of IL-1β and IL-18 in the supernatant (P<0.01). Conclusion The SIRT1 expression decreased, and that of NLRP3 expression increased in inflammatory periodontal ligament cells. MOP intervention promoted SIRT1 expression, resulting in the inhibition of NLRP3. Meanwhile, the acetylation level of NLRP3 reduced through deacetylation, leading to the decreased activity of NLRP3. Thus, MOP acted as inflammatory suppressor.

Key words: periodontitis, morinda officinalis polysaccharides, silent information regulator transcript 1, NOD-like receptor thermal protein domain associated protein 3, deacetylation

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