Department of Anesthesiology, Nihon University School of Dentistry, Tokyo, Japan.
Division of Immunology and Pathology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan.
Immun Inflamm Dis. 2021 Mar;9(1):265-273. doi: 10.1002/iid3.389. Epub 2020 Dec 3.
Transcriptional regulation of autophagy depends on the transcription factors coordinated inflammatory feedback mechanism. Here, we provide a comprehensive functional characterization of periodontal ligament fibroblasts (PDLFs) treated with Porphyromonas gingivalis lipopolysaccharide (LPS), aiming to reveal previously unappreciated biological changes and to investigate how a transcription factor differentiated embryonic chondrocytes 2 (Dec2)-deficient environment influences the function of autophagy in nflamed human PDLFs.
A Dec2-deficient (Dec2KO) experimental periodontal inflammation mouse model and treatment with P. gingivalis LPS were employed to examine the role of autophagy in PDLFs using hematoxylin and eosin staining and immunohistochemistry in vivo. A Dec2 small interfering RNA (siRNA) was used to modulate autophagy, and the effect of autophagy on the Dec2 pathway was explored using real-time polymerase chain reaction and western blot analysis in vitro.
LPS-treated human PDLFs (HPDLFs) induced autophagy, as demonstrated by the enhanced levels of microtubule-associated protein 1 light chain 3-II (LC3-II) and the induction of ATG5, Beclin1, and Dec2. Compared with a scrambled siRNA, a Dec2 siRNA triggered the detrimental influences of LPS and markedly enhanced autophagy expression in inflamed HPDLFs. The expression of phosphorylated ERK was increased and levels of phosphorylated mammalian target of rapamycin (mTOR) were decreased after exposure to LPS in Dec2 siRNA transfected HPDLFs. The Dec2KO model exhibited that P. gingivalis in Dec2 deficient conditions increases the inflammation of PDLFs by regulating autophagy.
These results demonstrate that a Dec2 deficiency can alleviate LPS-induced inflammation via the ERK/mTOR signaling pathway by regulating autophagy, conceivably delivering a novel approach for the detection of periodontal treatments.
自噬的转录调控依赖于转录因子协调的炎症反馈机制。在这里，我们对牙周膜成纤维细胞（PDLFs）进行了全面的功能特征分析，这些细胞用牙龈卟啉单胞菌脂多糖（LPS）处理，旨在揭示以前未被重视的生物学变化，并研究转录因子分化胚胎软骨细胞 2（Dec2）缺陷环境如何影响炎症人牙周膜成纤维细胞（HPDLFs）中的自噬功能。
使用 Dec2 缺陷（Dec2KO）实验性牙周炎小鼠模型和牙龈卟啉单胞菌 LPS 处理，在体内使用苏木精和伊红染色和免疫组织化学检查自噬在 PDLFs 中的作用。使用 Dec2 小干扰 RNA（siRNA）调节自噬，并使用实时聚合酶链反应和 Western blot 分析体外探索自噬对 Dec2 途径的影响。
LPS 处理的人牙周膜成纤维细胞（HPDLFs）诱导自噬，微管相关蛋白 1 轻链 3-II（LC3-II）水平升高，ATG5、Beclin1 和 Dec2 诱导。与 scrambled siRNA 相比，Dec2 siRNA 触发了 LPS 的有害影响，并在炎症 HPDLFs 中显著增强了自噬表达。暴露于 LPS 后，在转染 Dec2 siRNA 的 HPDLFs 中，磷酸化 ERK 的表达增加，磷酸化哺乳动物雷帕霉素靶蛋白（mTOR）的水平降低。Dec2KO 模型表明，在 Dec2 缺乏的情况下，牙龈卟啉单胞菌通过调节自噬增加 PDLFs 的炎症。
这些结果表明，Dec2 缺乏可通过调节自噬通过 ERK/mTOR 信号通路减轻 LPS 诱导的炎症，为牙周治疗的检测提供了一种新方法。
