Molecular mechanisms of posttranscriptional gene regulation in asthmatic airway inflammation

哮喘仍然是一种难以治疗的疾病，极大地影响了已部署的军事人员和退伍军人。 目前使用的药物：1)非常昂贵(生物制品)，给退伍军人管理局带来了巨大的负担 医疗系统；2)有显著的副作用(口服类固醇)；或3)在某些内型中不起作用，例如， 激素抵抗型哮喘。由于稳定状态的信使核糖核酸水平和蛋白质之间的不一致，转录 这些方法可能会忽略受RNA结合蛋白(RBPs)调控的基因。转录后基因调控 通过限制性商业惯例和微小RNAs(MiRNAs)越来越被认为是一种重要的控制机制。 炎症基因，但研究不足。限制性商业惯例，如Hur(Eavl1)，它与富含AU的信使核糖核酸结合 (ARES)，通过调节mRNA的稳定性和关键致炎基因表达的翻译发挥关键作用 得了哮喘。我们最近发表的数据表明，HUR消融小鼠可以改善过敏原驱动的肺 发炎。此外，HUR在哮喘CD4T细胞中过表达，其抑制减少了细胞因子 表情。利用RNA免疫沉淀技术(RIP-seq)结合基因工程小鼠 模型中，我们已经证明了HUR控制Th2和Th17 CD4T谱系。如果没有更好的 了解转录后控制炎症，该领域将继续有有限的洞察力 可能导致哮喘内型和治疗反应不平等的分子机制 患者的结局。我们的长期目标是了解不同基因转录后的调控。 哮喘呼吸道炎症的内型学研究。该应用程序目标是确定HUR和TTP如何 家族成员调节不同哮喘患者CD4T细胞产生的关键致炎分子 内型。我们的理论基础是，对HUR驱动的基因表达的研究将确定分子机制 哮喘内型之间的差异，特别是2型高与非2型高。中心假设是 CD4T细胞中Hur-GATA3的相互作用控制着2型高哮喘患者的呼吸道炎症(由 GATA3)和非2型高哮喘(由IL17驱动)。我们计划检验中心假设并实现 这些目标通过以下三个具体目标：1)确定了HUR调节的分子机制 2型-高气道炎的小鼠模型；2)阐明人类CD4T细胞基因簇允许 3)HUR抑制对哮喘患者T细胞介导的炎症的影响 2高发组和非2型高发组。在完成拟议的研究后，我们的预期结果是 确定HUR如何控制CD4T细胞的分化和功能，这对疾病的发展至关重要 过敏性呼吸道炎症。预计这些结果将对实地产生持续的积极影响。 因为他们将进一步确定区分2型高哮喘和非2型高哮喘的分子机制 内型。所获得的基本重要知识将为开发新疗法提供机会。 通过干预HUR功能治疗哮喘肺部炎症，包括类固醇抵抗型哮喘。

Asthma remains a difficult to treat disease that greatly impacts deployed military personnel and Veterans. Currently used medications either: 1) are very expensive (biologics), placing enormous burdens on the VA Healthcare System; 2) have significant side effects (oral steroids); or 3) do not work in some endotypes, e.g., steroid-resistant asthma. Due to discordance between steady-state mRNA levels and protein, transcriptomic approaches may overlook genes regulated by RNA binding proteins (RBPs). Posttranscriptional gene regulation by RBPs and microRNAs (miRNAs) is increasingly recognized as an important control mechanism for pro- inflammatory genes but understudied. RBPs, such as HuR (Elavl1), which binds to mRNA AU-rich elements (AREs), play critical roles by regulating mRNA stability and translation of key pro-inflammatory gene expression in asthma. Our recently published data indicates that HuR ablation in mice ameliorates allergen-driven lung inflammation. Furthermore, HuR is over-expressed in asthmatic CD4+ T cells and its inhibition reduces cytokine expression. Using RNA Immunoprecipitation techniques (RIP-seq) combined with genetically engineered murine models, we have demonstrated that HuR controls both Th2 and Th17 CD4+ T lineages. Without a better understanding of posttranscriptional control of inflammation, the field will continue to have a limited insight into molecular mechanisms, which likely contribute to asthma endotypes and unequal treatment responses and outcomes in patients. Our long-term goal is to understand posttranscriptional gene regulation in different endotypes of asthmatic airway inflammation. The objective of this application is to determine how HuR and TTP family members regulate key pro-inflammatory molecules produced by CD4+ T cells in different asthma endotypes. Our rationale is that investigation of HuR-driven gene expression will identify molecular mechanisms that differ between asthma endotypes, especially type 2-high vs. non-type 2-high. The central hypothesis is that the HuR-Gata3 interaction in CD4+ T cells controls airway inflammation in type 2-high asthma (driven by Gata3) and in non-type 2-high asthma (driven by Il17). We plan to test the central hypothesis and accomplish these objectives by the following three specific aims: 1) Define molecular mechanisms of HuR regulation in murine models of type 2-high airway inflammation; 2) Elucidate human CD4+ T cell gene clusters permissive for asthmatic lung inflammation and 3) Determine effects of HuR inhibition on T cell-mediated inflammation in type 2 high and non-type 2 high asthma. At the completion of the proposed research, our expected outcomes are to identify how HuR controls CD4+ T cell differentiation and function, which are critical for the development of allergic airway inflammation. These results are anticipated to have a sustained positive impact upon the field because they will further define molecular mechanisms distinguishing type 2 high from non-type 2 high asthma endotypes. The fundamentally important knowledge gained will provide opportunities to develop novel therapies to treat asthmatic lung inflammation by interfering with HuR function, including in steroid-resistant asthma.