Mahmoudi Javad, Sabermarouf Babak, Baradaran Behzad, Sadat-Hatamnezhad Leila, Shotorbani Siamak Sandoghchian
Neurosciences Research Center, Tabriz University of Medical Science, Tabriz, Iran.
Immunology Research Center, Tabriz University of Medical Science, Tabriz, Iran.
Iran J Basic Med Sci. 2017 Feb;20(2):209-215. doi: 10.22038/ijbms.2017.8250.
High Mobility Group Box1 (HMGB1) is a nonhistone, DNA-binding protein that serves a crucial role in regulating gene transcription and is involved in a variety of proinflammatory, extracellular activities. The aim of this study was to explore whether HMGB1 stimulation can up-regulate the expression of Toll-like Receptor 2 (TLR2) and Toll-like Receptor 4 (TLR4) on macrophages from pulpitis and to clarify the subsequent events involving Th17 cells and Th17 cell-associated cytokine changes.
Having prepared dental pulp tissues of pulpitis and healthy controls, macrophage were isolated and cultured. Macrophages were thereafter stimulated by HMGB1 time course. RT-QPCR, flowcytometer, immunofluorescence, Western blotting, and ELISA techniques were used in the present research.
Our results showed that the expression of TLR2 and TLR4 on macrophages stimulated with HMGB1 increased in pulpitis compared with controls (macrophages without HMGB1 stimulation) with a statistical significance (<0.001). In addition, the levels of IL-17, IL-23, and IL-6 in supernatants from cultured macrophages stimulated with HMGB1 from pulpitis increased, and NF-kB, the downstream target of TLR2 and TLR4, also showed a marked elevation after macrophages' stimulation by HMGB1.
The evidence from the present study suggests that the enhanced TLR2 and TLR4 pathways and Th17 cell polarization may be due to HMGB1 stimulation in pulpitis.
高迁移率族蛋白B1（HMGB1）是一种非组蛋白DNA结合蛋白，在调节基因转录中起关键作用，并参与多种促炎细胞外活动。本研究旨在探讨HMGB1刺激是否能上调牙髓炎巨噬细胞上Toll样受体2（TLR2）和Toll样受体4（TLR4）的表达，并阐明随后涉及Th17细胞的事件以及Th17细胞相关细胞因子的变化。
制备牙髓炎和健康对照的牙髓组织，分离并培养巨噬细胞。此后，巨噬细胞接受HMGB1时间进程刺激。本研究采用实时定量聚合酶链反应（RT-QPCR）、流式细胞仪、免疫荧光、蛋白质印迹法和酶联免疫吸附测定（ELISA）技术。
我们的结果表明，与对照组（未接受HMGB1刺激的巨噬细胞）相比，HMGB1刺激的牙髓炎巨噬细胞上TLR2和TLR4的表达增加，具有统计学意义（<0.001）。此外，来自牙髓炎HMGB1刺激的培养巨噬细胞上清液中白细胞介素-17（IL-17）、白细胞介素-23（IL-23）和白细胞介素-6（IL-6）水平升高，TLR2和TLR4的下游靶点核因子-κB（NF-κB）在巨噬细胞接受HMGB1刺激后也显著升高。
本研究证据表明，牙髓炎中TLR2和TLR4途径增强以及Th17细胞极化可能是由于HMGB1刺激所致。
