School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK.
Department of Oral Medicine and Oral Surgery, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan.
Int Endod J. 2021 Jun;54(6):941-950. doi: 10.1111/iej.13483. Epub 2021 Feb 25.
To investigate the ability of dead odontoblasts to initiate NLRP3 inflammasome-dependent sterile inflammation and to explore the effect on dental pulp cell (DPCs) migration, proliferation and odontogenic differentiation.
Odontoblast-like cells were subjected to freezing-thawing cycles to produce odontoblast necrotic cell lysate (ONCL). DPCs were treated with ONCL to assess proliferation and migration. THP-1 differentiated macrophages stimulated with ONCL and live cell imaging and western blotting were used to assess NLRP3 inflammasome activation. Cytokines were measured with multiplex arrays and ELISA. qPCR, alkaline phosphatase and Alizarin red assays were used to assess odontogenic differentiation of DPCs. Data were analysed using the t-test or anova followed by a Bonferroni post hoc test with the level of significance set at P ≤ 0.05.
ONCL induced migration and proliferation of DPCs. Treatment of THP-1 macrophages with ONCL resulted in the release of the inflammatory cytokines IL-1β, IL-6, IL-8, TNFα, IFN-γ, CCL2 and angiogenic growth factors, angiogenin and angiopoietin. This inflammatory response was associated with activation of NFκB, p38MAPK and NLRP3 inflammasome. To confirm that ONCL induced inflammatory response is NLRP3 inflammasome-dependent, treatment with a caspase-1 inhibitor and a specific NLRP3 inhibitor significantly reduced IL-1β release in THP-1 macrophages (P = 0.01 and 0.001). Inflammasome activation product, IL-1β, induced odontogenic differentiation of DPCS as evident by the increase in odontogenic genes expression DMP-1, RUNX-2, DSPP and SPP, alkaline phosphatase activity and mineralization.
Dead odontoblasts induced NLRP3 inflammasome-dependent sterile inflammation and activated the migration, proliferation and differentiation of DPCs.
研究死亡成牙本质细胞引发 NLRP3 炎性小体依赖性无菌性炎症的能力，并探讨其对牙髓细胞（DPCs）迁移、增殖和牙源性分化的影响。
采用冻融循环法制备成牙本质细胞样细胞的坏死细胞裂解物（ONCL）。用 ONCL 处理 DPCs 以评估增殖和迁移。用 ONCL 刺激 THP-1 分化的巨噬细胞，通过实时细胞成像和 Western blot 检测 NLRP3 炎性小体的激活。采用多重微阵列和 ELISA 检测细胞因子。通过 qPCR、碱性磷酸酶和茜素红染色检测 DPCs 的牙源性分化。采用 t 检验或方差分析 followed by Bonferroni 事后检验进行数据分析，显著性水平设为 P≤0.05。
ONCL 诱导 DPCs 迁移和增殖。用 ONCL 处理 THP-1 巨噬细胞可导致促炎细胞因子 IL-1β、IL-6、IL-8、TNFα、IFN-γ、CCL2 和血管生成生长因子、血管生成素和血管生成素释放。这种炎症反应与 NFκB、p38MAPK 和 NLRP3 炎性小体的激活有关。为了证实 ONCL 诱导的炎症反应依赖于 NLRP3 炎性小体，用 caspase-1 抑制剂和特异性 NLRP3 抑制剂处理可显著减少 THP-1 巨噬细胞中 IL-1β 的释放（P=0.01 和 0.001）。炎性小体激活产物 IL-1β 诱导 DPCS 的牙源性分化，表现为牙源性基因表达 DMP-1、RUNX-2、DSPP 和 SPP、碱性磷酸酶活性和矿化增加。
死亡成牙本质细胞诱导 NLRP3 炎性小体依赖性无菌性炎症，并激活 DPCs 的迁移、增殖和分化。
