State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Pediatric Dentistry, School of Stomatology, The Fourth Military Medical University, No.145 West Changle Road, Xi'an, 710032, Shaanxi, China.
Department of Orthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.
BMC Oral Health. 2021 Nov 3;21(1):560. doi: 10.1186/s12903-021-01894-5.
Nicotine is an important risk factor and the main toxic component associated with periodontitis. However, the mechanism of nicotine induced periodontitis is not clear. To investigated the mechanism through which nicotine regulates autophagy of human periodontal ligament cells (hPDLCs) through the alpha7 nicotinic acetylcholine receptor (α7 nAChR) and how autophagy further regulates the release of IL-1β and IL-8 secretion in hPDLCs.
HPDLCs were obtained from root of extracted teeth and pre-incubated in alpha-bungarotoxin (α-BTX) or 3-Methyladenine (3-MA), followed by culturing in nicotine. We used a variety of experimental detection techniques including western blotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), transmission electron microscopy (TEM) and RT-qPCR to assess the expression of the LC3 protein, autolysosome, and release of IL-1β and IL-8 from hPDLCs.
Western blots, immunofluorescence and TEM results found that the nicotine significantly increased the autophagy expression in hPDLCs that was time and concentration dependent and reversed by α-BTX treatment (p < 0.05). RT-qPCR and ELISA results revealed a noticeable rise in the release of inflammatory factors IL-1β and IL-8 from hPDLCs in response to nicotine. RT-qPCR and ELISA results showed that nicotine can significantly up-regulate the release of inflammatory factors IL-1β and IL-8 in hPDLCs, and this effect can be inhibited by 3-MA (p < 0.05).
Nicotine regulated autophagy of hPDLCs through α7 nAChR and in turn the regulation of the release of inflammatory factors 1L-1β and 1L-8 by hPDLCs.
尼古丁是牙周炎的一个重要危险因素和主要毒性成分。然而，尼古丁诱导牙周炎的机制尚不清楚。本研究旨在通过α7 烟碱型乙酰胆碱受体（α7 nAChR）探讨尼古丁调节人牙周膜细胞（hPDLCs）自噬的机制，以及自噬如何进一步调节 hPDLCs 中白细胞介素 1β（IL-1β）和白细胞介素 8（IL-8）的释放。
从拔出的牙齿的根部获得 hPDLCs，并在α-银环蛇毒素（α-BTX）或 3-甲基腺嘌呤（3-MA）中预孵育，然后在尼古丁中培养。我们使用各种实验检测技术，包括 Western blot、免疫荧光、酶联免疫吸附试验（ELISA）、透射电子显微镜（TEM）和 RT-qPCR，评估 LC3 蛋白的表达、自噬体以及 hPDLCs 中 IL-1β和 IL-8 的释放。
Western blot、免疫荧光和 TEM 结果发现，尼古丁明显增加了 hPDLCs 的自噬表达，且这种作用具有时间和浓度依赖性，并可被α-BTX 处理逆转（p < 0.05）。RT-qPCR 和 ELISA 结果显示，hPDLCs 对尼古丁的反应导致炎症因子 IL-1β和 IL-8 的释放明显增加。RT-qPCR 和 ELISA 结果表明，尼古丁可显著上调 hPDLCs 中炎症因子 IL-1β和 IL-8 的释放，而 3-MA 可抑制这种作用（p < 0.05）。
尼古丁通过 α7 nAChR 调节 hPDLCs 的自噬，进而调节 hPDLCs 中炎症因子 IL-1β和 IL-8 的释放。
