The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
Int Endod J. 2018 Oct;51(10):1130-1138. doi: 10.1111/iej.12921. Epub 2018 Mar 25.
To identify the role of astrocyte elevated gene-1 (AEG-1) and the mechanism underlying the inflammatory response in dental pulp cells.
Astrocyte elevated gene-1 expression was detected at different stages of pulpitis in a rat model using immunohistochemistry. RT-qPCR and Western blot were used to assess AEG-1 expression in human dental pulp cells stimulated by lipopolysaccharide (LPS). The LPS-induced expression of inflammatory cytokine genes was quantified by RT-qPCR in cells transfected with AEG-1 or negative control (NC) siRNA. Immunofluorescence and Western blot were utilized to evaluate the activation of NF-κB signalling in AEG-1 knockdown cells. AEG-1 expression was also investigated by Western blot in dental pulp cells pre-treated with inhibitors of NF-κB and PI-3K signalling before the addition of LPS. Data were analysed statistically using one-way anova.
The exposure of dental pulp tissue to LPS resulted in acute inflammation with necrosis and AEG-1 expression in the pulp tissue beneath the perforation. In LPS-stimulated dental pulp cells, AEG-1 mRNA and protein were significantly up-regulated (P < 0 .05) in a time- and dose-dependent manner. In AEG-1 knockdown cells, the synthesis of IL-1, IL-6 and TNF-α mRNA was suppressed significantly (P < 0.05) upon LPS induction. AEG-1 knockdown also inhibited nuclear translocation of p65. Suppression of NF-κB and PI-3K abrogated the LPS-induced up-regulation of AEG-1.
Astrocyte elevated gene-1 participated in inflammatory cytokine synthesis via NF-κB signalling in the dental pulp. Both NF-κB and PI-3K signalling are involved in LPS-induced AEG-1 expression in dental pulp cells.
鉴定星形细胞上调基因-1（AEG-1）在牙髓细胞炎症反应中的作用及其机制。
采用免疫组织化学法检测大鼠模型中牙髓炎不同阶段的 AEG-1 表达。采用 RT-qPCR 和 Western blot 检测脂多糖（LPS）刺激下人牙髓细胞 AEG-1 的表达。用 AEG-1 或阴性对照（NC）siRNA 转染细胞，通过 RT-qPCR 定量检测 LPS 诱导的炎症细胞因子基因表达。用免疫荧光和 Western blot 检测 AEG-1 敲低细胞中 NF-κB 信号的激活。用 NF-κB 和 PI-3K 信号通路抑制剂预处理牙髓细胞，然后加入 LPS，用 Western blot 检测 AEG-1 的表达。采用单因素方差分析对数据进行统计学分析。
牙髓组织暴露于 LPS 导致穿孔下方牙髓组织发生急性炎症伴坏死和 AEG-1 表达。在 LPS 刺激的牙髓细胞中，AEG-1mRNA 和蛋白水平呈时间和剂量依赖性显著上调（P<0.05）。在 AEG-1 敲低细胞中，LPS 诱导时 IL-1、IL-6 和 TNF-αmRNA 的合成显著受抑制（P<0.05）。AEG-1 敲低也抑制了 p65 的核转位。NF-κB 和 PI-3K 的抑制消除了 LPS 诱导的 AEG-1 上调。
AEG-1 通过牙髓中的 NF-κB 信号参与炎症细胞因子的合成。NF-κB 和 PI-3K 信号通路均参与 LPS 诱导的牙髓细胞中 AEG-1 的表达。
