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[P-032] 歯石により誘導されるHSC-2口腔上皮細胞の細胞死において結晶構造および菌体成分が果たす役割

The role of crystalline structures and microbial components in HSC-2 oral epithelial cell death induced by dental calculus

SM Ziauddin¹，吉村 篤利¹，Jorge Luis Montenegro Raudales¹，尾崎 幸生¹，樋口 賀奈子¹，金子 高士²，原 宜興¹／SM Ziauddin¹，Atsutoshi Yoshimura¹，Jorge Luis Montenegro Raudales¹，Yukio Ozaki¹，Kanako Higuchi¹，Takashi Kaneko²，Yoshitaka Hara¹ (長崎大学大学院医歯薬学総合研究科 歯周病学分野¹，福岡歯科大学口腔医療センター²／Department of Periodontology, Nagasaki University Graduate School of Biomedical Scieces¹，Center for Oral Diseases, Fukuoka Dental College²)

研修コード：2504

Keywords:歯石、細胞死、結晶構造

Objective: Previously, we found that dental calculus could induce cell death via NLRP3 inflammasome in HSC-2 oral epithelial cells. Dental calculus contains both crystalline structures and microbial components, however, the relative importance of these components in HSC-2 cell death has not been investigated. This study aimed to determine which component of dental calculus plays an important role in HSC-2 cell death.
Materials and methods: To inactivate microbial components, dental calculus samples from five periodontitis patients were treated at 250ﾟC for 1 hour（baked）or left untreated（unbaked）. HSC-2 cells were exposed to 500 μg/ml of unbaked or baked calculus. The cells were also exposed to synthetic hydroxyapatite（HA）crystals, which contain no microbial components, in the presence or absence of LPS or Pam₃CSK₄. After 24 hours, cytotoxicity was quantified by measuring lactate dehydrogenase release in the culture supernatants.
Results: Unbaked and baked calculus induced a similar level of cell death in HSC-2 cells. HA crystals also induced cell death in HSC-2 cells and addition of LPS or Pam ₃CSK ₄ did not change its cytotoxicity.
Conclusion: Crystalline structures play a major role in the HSC-2 cell death induced by dental calculus. The non-significant contribution of microbial products to cell death might be due to the low sensitivity of HSC-2 cells to microbial ligands.