Laboratory of Molecular Immunobiology, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan.
Life Science Collaboration Center (LiSCo), Nara Institute of Science and Technology (NAIST), Nara 630-0192, Japan.
Int Immunol. 2024 Aug 13;36(9):471-481. doi: 10.1093/intimm/dxae024.
Interleukin-6 (IL-6) plays a crucial role in various cellular functions, including innate and adaptive immune responses. Dysregulated expression of IL-6 is associated with hyperinflammation and chronic inflammatory diseases. In this study, we aimed to identify the enhancer regions responsible for robust Il6 mRNA expression in murine macrophages. Through comprehensive genome-wide ChIP- and ATAC-seq analyses, we identified two distinct clusters, termed E1 and E2 regions, located at -144 to -163 kb relative to the Il6 transcription start site in lipopolysaccharide (LPS)-activated murine macrophages. These clusters exhibited an accumulation of histone modification marks (H3K27ac and H3K4me1), as well as open chromatin, and were found to contain binding sites for the transcription factors PU.1, NF-κB, C/EBPβ, and JunB. Upregulation of non-coding RNA (ncRNA) transcripts from the E1 and E2 regions was observed upon LPS stimulation, and repression of these ncRNAs resulted in abrogation of Il6 expression. Additionally, deletion of either E1 or E2 region significantly impaired Il6 expression, while CRISPR/dCas9 activation-mediated recruitment of the co-activator p300 to the E1 and E2 regions facilitated Il6 expression. Collectively, our findings suggest that the E1 and E2 regions serve as putative enhancers for Il6 expression.
白细胞介素 6（IL-6）在各种细胞功能中发挥着关键作用，包括先天和适应性免疫反应。IL-6 的表达失调与过度炎症和慢性炎症性疾病有关。在这项研究中，我们旨在鉴定负责在鼠巨噬细胞中产生强烈 Il6 mRNA 表达的增强子区域。通过全面的全基因组 ChIP 和 ATAC-seq 分析，我们在脂多糖（LPS）激活的鼠巨噬细胞中，鉴定了两个位于 Il6 转录起始位点的 -144 到 -163 kb 相对位置的独特簇，分别称为 E1 和 E2 区域。这些簇表现出组蛋白修饰标记（H3K27ac 和 H3K4me1）的积累，以及开放染色质，并且被发现包含转录因子 PU.1、NF-κB、C/EBPβ 和 JunB 的结合位点。在 LPS 刺激下，观察到来自 E1 和 E2 区域的非编码 RNA（ncRNA）转录本的上调，并且这些 ncRNA 的抑制导致 Il6 表达的阻断。此外，E1 或 E2 区域的缺失显著损害 Il6 表达，而 CRISPR/dCas9 激活介导的共激活因子 p300 募集到 E1 和 E2 区域促进 Il6 表达。总之，我们的研究结果表明，E1 和 E2 区域是 Il6 表达的假定增强子。
