Post-Initiation control of transcription in inflammatory macrophages

炎症巨噬细胞转录起始后控制

• 批准号: 10540683
• 负责人: INEZ ROGATSKY
• 金额: $ 59.08万
• 依托单位: HOSPITAL FOR SPECIAL SURGERY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-23 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10540683
• 关键词: Acute; Anti-Inflammatory Agents; Autoimmune Diseases; Behavior; Binding; Cartilage; Cells; Chemicals; Chromatin; Chronic; Complex; Data; Dependence; Disease; Elongation Factor; Endotoxins; Enhancers; Enzymes; Epigenetic Process; Equilibrium; Future; Gene Expression; Genes; Genetic; Genetic Transcription; Glucocorticoid Receptor; Glucocorticoids; Goals; Health; Hyperactivity; Immune; Immunity; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Arthritis; Inflammatory Response; Invaded; Ligand Binding; Macrophage; Malignant - descriptor; Malignant Neoplasms; Mediating; Modeling; Molecular; Mus; NF-kappa B; Pathogenesis; Pathology; Pathway interactions; Patient Care; Peritonitis; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Play; Polymerase; Positive Transcriptional Elongation Factor B; Pre-Clinical Model; Productivity; Progressive Disease; Proliferating; Proteins; Publishing; RNA; RNA Polymerase II; Regulation; Reporting; Repression; Rheumatoid Arthritis; Role; Shock; Signal Transduction; Testing; Therapeutic; Therapeutic Glucocorticoid; Time; Tissues; Toxic effect; Transcription Elongation; Transcription Factor AP-1; Transcription Initiation; Transcriptional Regulation; Translating; Work; anticancer research; arthropathies; attenuation; bone; bone invasion; cancer therapy; cyclin T1; gene induction; genome-wide; in vivo; inhibitor; insight; mouse model; negative elongation factor; neoplastic cell; novel; novel therapeutic intervention; permissiveness; pharmacologic; promoter; recruit; response; small molecule; transcription factor; transcriptome; tumor

Macrophage (MΦ)-driven inflammation is at the core of autoimmune diseases including rheumatoid arthritis (RA), signifying imbalance between circuits that turn inflammatory genes on and off. The `on' state is conferred by transcription factors such as NFκB that activate basal transcription machinery and chromatin at pro- inflammatory enhancers and promoters. An equally robust `off' signal is conveyed by the glucocorticoid (GC) receptor (GR) which, upon ligand binding, tethers to NFκB and represses its targets. Notably, these genes form distinct classes: those for which RNA polymerase (Pol) II recruitment and transcription initiation are rate- limiting, and those whose promoters are pre-loaded by initiated but paused Pol II and pause-enforcing factors, NELF and DSIF. Pause-release requires the positive elongation factor, P-TEFb, a kinase that phosphorylates Pol II, NELF and DSIF leading to NELF release and productive elongation. Importantly, assembly of the Pol II- NELF-DSIF `paused complex' is tightly regulated by another kinase, CDK7. To date, the role of post-initiation control of transcription in immunity and disease is unknown. Our preliminary data in MΦ reveal transcriptome- wide Pol II pausing and unexpectedly dynamic behavior of NELF upon inflammatory stimulation. NELF deletion dramatically shifted the balance of pro- and anti-inflammatory mediators and blunted inflammatory responses over time. The pausing complex is also a critical target of GC - the cornerstone of anti-inflammatory therapies. Although basal machinery and chromatin were once considered too general to be `druggable', pioneering work in cancer research uncovered the benefits of targeting epigenetic regulators and, more recently, CDK7. In RA, the transformation of the synovial lining into aggressively proliferating cartilage- and bone-invading tissue is often viewed as malignant. Like tumor cells, synovial MΦ enter a state of transcriptional dependency with a few super-enhancers dominating the inflammatory transcriptome. These data point to CDK7 inhibition as a novel promising avenue to treat RA as a monotherapy or in combination with GC. Our objective is to dissect the specific contribution of post-initiation control to inflammation - in MΦ and in mouse models of RA. Our central hypothesis is that pausing plays an essential `permissive' role in MΦ-driven inflammation by constraining anti- inflammatory gene expression. We further propose that genetic and pharmacologic manipulation of Pol II pausing will yield important insights into the pathogenesis of inflammatory diseases such as RA, with potential to be translated into advances in patient care. Our Specific Aims are to: 1. Dissect the role of the pause- release checkpoint in inflammatory gene induction in MΦ; 2. Evaluate early elongation and higher-order chromatin interactions in MΦ as targets for GR; 3. Assess the utility of manipulating elongation control in vivo using inflammatory arthritis models. The successful completion of this project will: i) reveal the contribution of Pol II pausing to inflammatory MΦ activation; ii) help refine the anti-inflammatory actions of GC; iii) uncover the potential of new therapeutic strategies targeting the early elongation checkpoint in preclinical models of RA.

巨噬细胞(MΦ)诱导的炎症是包括类风湿性关节炎在内的自身免疫性疾病的核心 (RA)，意味着启动和关闭炎症基因的回路之间的失衡。‘on’状态被授予 通过转录因子，如核因子κB，激活基础转录机制和染色质在蛋白- 炎症增强剂和促进剂。糖皮质激素(GC)也传递着同样强烈的“关”信号。 受体(GR)，与配体结合后，与核因子κB结合并抑制其靶标。值得注意的是，这些基因 形成不同的类别：那些RNA聚合酶(POL)II招募和转录启动是速率- 限制，以及其启动者被启动但暂停的POLII和暂停强制因素预加载的那些， NELF和DSIF。暂停释放需要正的延长因子P-TEFb，这是一种磷酸化的激酶 POL II、NELF和DSIF导致NELF的释放和生产伸长。重要的是，POL II的组装- NELF-DSIF“暂停的复合体”受到另一种激酶CDK7的严格调控。迄今为止，印心后的作用 免疫和疾病中的转录调控尚不清楚。我们在MΦ上的初步数据揭示了转录组- 炎性刺激时NELF的广角停顿和意外的动态行为。NELF删除 极大地改变了促炎和抗炎介质的平衡，钝化了炎症反应 随着时间的推移。停顿的复合体也是GC的关键靶点--GC是抗炎治疗的基石。 尽管基础机械和染色质曾被认为过于笼统，不能用药，但开创性的工作 在癌症研究中发现了靶向表观遗传调节因子和最近的CDK7的好处。在RA， 滑膜衬里转化为侵袭软骨和骨的组织。 通常被认为是恶性的。像肿瘤细胞一样，滑膜MΦ进入转录依赖状态 控制炎症转录组的超级增强子。这些数据表明，CDK7的抑制是一种新的 作为单一疗法或与GC联合治疗类风湿关节炎，前景看好。我们的目标是剖析 在MΦ和RA小鼠模型中，启动后控制对炎症的特定贡献。我们的中央 假设停顿在M-Φ引起的炎症中起着重要的“允许”作用，因为它抑制了抗- 炎性基因表达。我们进一步提出，POL II的遗传和药理作用 暂停将为类风湿性关节炎等炎症性疾病的发病机制提供重要的见解，具有潜在的 转化为病人护理方面的进步。我们的具体目标是：1.剖析停顿的作用-- M-Φ炎症基因诱导中的释放检查点；2.评估早期延长和更高阶数 作为GR靶点的M-Φ中的染色质相互作用；3.评估体内操纵伸长控制的有效性 使用炎症性关节炎模型。该项目的成功完成将：i)揭示以下贡献 POL II暂停炎症性MΦ激活；ii)帮助改进GC的抗炎作用；III)揭示 针对RA临床前模型早期延长检查点的新治疗策略的可能性。