Program for RNA Biology, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 2014 Jan 21;111(3):1002-7. doi: 10.1073/pnas.1313768111. Epub 2013 Dec 26.
Thousands of large intergenic noncoding RNAs (lincRNAs) have been identified in the mammalian genome, many of which have important roles in regulating a variety of biological processes. Here, we used a custom microarray to identify lincRNAs associated with activation of the innate immune response. A panel of 159 lincRNAs was found to be differentially expressed following innate activation of THP1 macrophages. Among them, linc1992 was shown to be expressed in many human tissues and was required for induction of TNFα expression. Linc1992 bound specifically to heterogenous nuclear ribonucleoprotein L (hnRNPL) and formed a functional linc1992-hnRNPL complex that regulated transcription of the TNFα gene by binding to its promoter. Transcriptome analysis revealed that linc1992 was required for expression of many immune-response genes, including other cytokines and transcriptional and posttranscriptional regulators of TNFα expression, and that knockdown of linc1992 caused dysregulation of these genes during innate activation of THP1 macrophages. Therefore, we named linc1992 THRIL (TNFα and hnRNPL related immunoregulatory LincRNA). Finally, THRIL expression was correlated with the severity of symptoms in patients with Kawasaki disease, an acute inflammatory disease of childhood. Collectively, our data provide evidence that lincRNAs and their binding proteins can regulate TNFα expression and may play important roles in the innate immune response and inflammatory diseases in humans.
数以千计的哺乳动物基因组中的长链非编码 RNA(lincRNA)已被鉴定出来,其中许多在调节多种生物过程中发挥着重要作用。在这里,我们使用定制的微阵列来识别与先天免疫反应激活相关的 lincRNA。在 THP1 巨噬细胞先天激活后,发现有 159 个 lincRNA 表达谱发生差异。其中,linc1992 在许多人类组织中表达,并需要诱导 TNFα 表达。linc1992 特异性地与异质核核糖核蛋白 L(hnRNPL)结合,并形成功能性 linc1992-hnRNPL 复合物,通过结合其启动子来调节 TNFα 基因的转录。转录组分析显示,linc1992 是许多免疫反应基因表达所必需的,包括其他细胞因子和 TNFα 表达的转录和转录后调节剂,并且敲低 linc1992 导致 THP1 巨噬细胞先天激活时这些基因的失调。因此,我们将 linc1992 命名为 THRIL(TNFα 和 hnRNPL 相关免疫调节 LincRNA)。最后,THRIL 的表达与川崎病患者症状的严重程度相关,川崎病是一种儿童急性炎症性疾病。总之,我们的数据提供了证据表明 lincRNA 及其结合蛋白可以调节 TNFα 的表达,并可能在人类先天免疫反应和炎症性疾病中发挥重要作用。