Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China; and.
School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China.
J Immunol. 2018 Mar 1;200(5):1618-1626. doi: 10.4049/jimmunol.1601689. Epub 2018 Jan 29.
Inflammation that complicates many autoimmune diseases, such as multiple sclerosis (MS), has been correlated to abnormal differentiation of Th17 cells. However, the reasons that promote Th17 cell-driven autoimmunity are yet to be discovered. In this study, we sought evidence that DNA-damage-inducible transcript 4 (DDIT4) and its associated long noncoding RNA DDIT4 (lncDDIT4) inhibit Th17 cell differentiation. We recruited 36 patients. Six MS patients and five healthy volunteers (controls) contributed PBMCs as material for microarray analysis. Microarray assays of lncDDIT4 and DDIT4 RNA expression identified outstanding differences between MS and control subjects, which were verified with real-time quantitative PCR. We then interrupted the expression of lncDDIT4 and DDIT4 mRNA in MS patients' naive CD4 T cells and observed the resulting changes in Th17 cells. The expression of lncDDIT4 and DDIT4 mRNA were higher both in PBMCs and CD4 T cells of MS patients than in healthy controls. DDIT4 (2.79-fold upregulation) was then recognized as a candidate for the -regulated target of lncDDIT4 (4.32-fold upregulation). Isolation of naive CD4 T cells revealed enhanced levels of lncDDIT4 and DDIT4 after stimulated with Th17-inducing cytokines, but not after Th1, Th2, or T regulatory cell induction. Overexpression of lncDDIT4 in naive CD4 T cells inhibited IL-17 transcription through increased DDIT4 expression and decreased activation of the DDIT4/mTOR pathway. Consistently, silencing lncDDIT4 in naive CD4 T cells enhanced Th17 differentiation through increased activation of the DDIT4/mTOR pathway. However, these results vanished when DDIT4 was silenced. This outcome suggests that lncDDIT4 regulates Th17 cell differentiation by directly targeting DDIT4.
在多发性硬化症（MS）等许多自身免疫性疾病中，炎症与 Th17 细胞的异常分化有关。然而，促进 Th17 细胞驱动自身免疫的原因仍有待发现。在这项研究中，我们试图证明 DNA 损伤诱导转录物 4（DDIT4）及其相关的长非编码 RNA DDIT4（lncDDIT4）可抑制 Th17 细胞分化。我们招募了 36 名患者。6 名 MS 患者和 5 名健康志愿者（对照）提供 PBMC 作为微阵列分析的材料。lncDDIT4 和 DDIT4 RNA 表达的微阵列分析鉴定了 MS 和对照组之间的显著差异，并用实时定量 PCR 进行了验证。然后，我们中断了 MS 患者的幼稚 CD4 T 细胞中 lncDDIT4 和 DDIT4 mRNA 的表达，并观察了 Th17 细胞的变化。MS 患者的 PBMC 和 CD4 T 细胞中 lncDDIT4 和 DDIT4 mRNA 的表达均高于健康对照组。然后，DDIT4（上调 2.79 倍）被认为是 lncDDIT4 的 -调节靶标（上调 4.32 倍）。分离幼稚 CD4 T 细胞后发现，经 Th17 诱导细胞因子刺激后，lncDDIT4 和 DDIT4 水平升高，但经 Th1、Th2 或 T 调节细胞诱导后则不然。lncDDIT4 在幼稚 CD4 T 细胞中的过表达通过增加 DDIT4 表达和降低 DDIT4/mTOR 通路的激活来抑制 IL-17 转录。一致地，在幼稚 CD4 T 细胞中沉默 lncDDIT4 通过增加 DDIT4/mTOR 通路的激活增强了 Th17 分化。然而，当沉默 DDIT4 时，这些结果消失了。这一结果表明，lncDDIT4 通过直接靶向 DDIT4 调节 Th17 细胞分化。
