Involvement of apoptosis in Periodontal diseases

细胞凋亡参与牙周疾病

• 批准号: 18592267
• 负责人: KATO Satsuki
• 金额: $ 2.55万
• 依托单位: Health Sciences University of Hokkaido
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18592267/
• 关键词: Periodonatl diseases; A. actinomycetemcomitans; human monocytes; apoptosis; TNF-α; p38 MAP kinase; toll-like receptors (TLRs); Toll様レセプター(TLR); A. actinomycetemcomitans; p38 MAPキナーゼ

Objective: Aggregatibacter actinomycetemcomitans infection induces apoptosis in the human monocyte cell line THP-1. Toll-like receptors (TLRs), which are key components of the innate immune system, recognize conserved sequences on the surface of pathogens and trigger host cell function. However, roles of TLRs in the induction of apoptosis in A. actinomycetemcomitans-infected cells is unclear. The objective of this study was to examine the roles of TLRs in apoptosis of A. actinomycetemcornitans-infected THP-1 cells.Methods : A. actinomycetemcomitans was added to THP-1 cells suspended in microtubes ; subsequently, the tubes were centrifuged (1000 x g, 10 min). Non-adherent bacteria were removed via serial centrifugation. Infected cells were transferred to 6-well culture plates and incubated in the presence of either anti- TLR2 or -TLR4 antibody (10 μg/ ml). TLR mRNA level was confirmed by RT-PCR. Apoptotic cells were detected by APOPercentage ([○!R]) dye staining. Cellular p38 activity and NFκB activity were assessed with ELISA kitsResults: A significant increased in TLR2 mRNA level was observed in A. actinomycetemcomitans-infected cells. However, no meaningful change was detected in TLR4 mRNA level. NFκB activity increased following infection. Moreover, percentages of apoptotic cells as well as p38 MAPK and NFκB activities in infected cells decreased upon addition of anti-TLR2 antibody.Conclusion : These findings indicate that TLR2 play a key role in the apoptotic signal pathway and that both p38 MAPK and NFκB are involved in the pathway. Apoptosis of infected human immune cells may be an important mechanism in the progression of periodontal disease.

目的：伴生放线杆菌感染人单核细胞系THP-1诱导细胞凋亡。Toll样受体(Toll-like Receptor，TLRs)是天然免疫系统的重要组成部分，识别病原体表面的保守序列，启动宿主细胞功能。然而，TLRs在伴放线放线菌感染的细胞中诱导细胞凋亡的作用尚不清楚。本研究的目的是探讨TLRs在角放线杆菌感染THP-1细胞中的作用。方法：将伴生放线菌加入悬浮在微管中的THP-1细胞中，然后将管离心(1000×g，10min)。未贴壁细菌通过连续离心法去除。将感染细胞转移到6孔培养板上，加入抗TLR2或-TLR4抗体(10μg/ml)培养。逆转录聚合酶链式反应(RT-PCR)证实TLR基因表达。APO Percentage([0！R])染色检测细胞凋亡。结果：伴生放线菌感染细胞后，TLR2mRNA表达水平明显升高。而TLR4基因表达水平无明显变化。感染后，NF-κB活性升高。结论：TLR2在细胞凋亡信号通路中起关键作用，p38MAPK和NFκB均参与了这一信号通路。感染的人免疫细胞的凋亡可能是牙周病发生发展的重要机制。