Mechanisms of HuR Overexpression in Asthmatic Endotypes

哮喘内型中 HuR 过度表达的机制

• 批准号: 10570322
• 负责人: ULUS ATASOY
• 金额: $ 23.4万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-14 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10570322
• 关键词: 3' Untranslated Regions; Affect; Allergens; Asthma; Binding; CD4 Positive T Lymphocytes; Characteristics; Competitive Binding; Cytokine Gene; Data; Disease; Elements; Equilibrium; Family member; GATA3 gene; Gene Expression; Genes; Genetic Transcription; Goals; HuR protein; Human; Immune; Immunity; Inflammation; Inflammatory; Knowledge; Mediating; Messenger RNA; MicroRNAs; Mission; Modeling; Molecular; Morbidity - disease rate; Mus; Network-based; Outcome; Ovum; Play; Population; Post-Transcriptional Regulation; Production; Proteins; Public Health; Publishing; Pulmonary Inflammation; RNA-Binding Proteins; Regulation; Research; Research Personnel; Ribonucleoproteins; Role; System; T-Lymphocyte; TIS11 protein; Testing; Translations; United States National Institutes of Health; Work; ZFP36L2 gene; adaptive immunity; airway inflammation; allergic airway inflammation; asthmatic; asthmatic airway; cytokine; economic cost; genome-wide; mRNA Expression; mRNA Stability; messenger ribonucleoprotein; mouse model; novel; novel therapeutics; overexpression; posttranscriptional; symptom treatment; transcriptomics

Abstract Despite extensive research, asthma remains a difficult to treat disease with staggering economic costs. Mechanisms in different asthmatic endotype are poorly understood. Posttranscriptional gene regulation by RNA- binding proteins (RBPs) and microRNAs (miRNAs) is increasingly recognized as important control mechanisms for pro-inflammatory genes but is understudied. RBPs, such as HuR (Elavl1), tristetraprolin (TTP) family members which bind to mRNA AU-rich elements (ARE), play critical roles in regulating mRNA stability and expression of key pro-inflammatory genes in asthma. HuR is a stabilizer RBP, whereas TTP family members are destabilizer RBPs. Due to the discordance between steady-state mRNA levels and protein, purely transcriptomic approaches may overlook critical inflammatory genes regulated by RBPs such as HuR and TTP. Yet, much of immunity and inflammation is controlled at the posttranscriptional level by RBPs and miRNAs. Many cytokine genes in CD4+ T cells are controlled by the balance between HuR and TTP family members. The field cannot move forward unless we better understand how RBPs posttranscriptionally regulate pro-inflammatory gene expression in different asthmatic endotypes. Our long-term goal is to understand posttranscriptional gene regulation in different endotypes of asthmatic airway inflammation. The objective of this application, which is our next step in pursuit of that goal, is to determine how HuR and TTP family members competitively regulate HuR expression, which in turn controls CD4+ T produced cytokines in asthma. Our central hypothesis is that HuR overproduction in type 2 high asthma is driven by an imbalance between stabilizing and destabilizing RBPs acting upon Elavl1 mRNA to affect its stability and translation. Our data indicate that HuR is over-expressed in type 2 high asthmatic CD4+ T cells, compared with normal controls and non-type 2 high. Furthermore, we have shown that conditional HuR KO in T cells significantly ameliorates allergen-induced lung inflammation in murine models. We have also demonstrated that HuR inhibition blocks Th2/Th17 secretion in asthmatic CD4+ T cells. Up to the present, the field has focused mostly on downstream HuR targets genes. In contrast, HuR regulation is not as well understood. The rationale for this research is that the proposed research will enable us to identify molecular mechanisms which drive HuR over-production in the context of type 2 high asthmatic lung inflammation. We plan to test the central hypothesis and accomplish these objectives by the following two specific aims: 1) Determine normal mechanisms of HuR expression in airway inflammation; 2) Determine molecular mechanisms underlying HuR dysregulation in type 2 high asthma. At the completion of the proposed research, our expected outcomes are to identify how HuR and TTP cooperate to normally control HuR expression and how they become dysfunctional in type 2 high asthmatic CD4+ T cells. These results are expected to have a positive impact on the field because it will further define molecular mechanisms and provide opportunities to develop novel therapies to treat asthma.

抽象的 尽管进行了广泛的研究，哮喘仍然是一种难以治疗的疾病，其经济成本惊人。 不同哮喘内型的机制尚不清楚。 RNA-转录后基因调控 结合蛋白 (RBP) 和 microRNA (miRNA) 越来越被认为是重要的控制机制 促炎症基因，但尚未得到充分研究。 RBP，例如 HuR (Elavl1)、三四脯氨酸 (TTP) 家族 与富含 mRNA AU 的元件 (ARE) 结合的成员在调节 mRNA 稳定性和 哮喘中关键促炎基因的表达。 HuR 是 RBP 的稳定剂，而 TTP 家族成员是 不稳定 RBP。由于稳态 mRNA 水平和蛋白质之间的不一致，纯转录组学 这些方法可能会忽视由 RBP（例如 HuR 和 TTP）调节的关键炎症基因。然而，很多 免疫和炎症在转录后水平由 RBP 和 miRNA 控制。许多细胞因子 CD4+ T 细胞中的基因由 HuR 和 TTP 家族成员之间的平衡控制。田地不能 除非我们更好地了解 RBP 如何转录后调节促炎基因，否则我们将继续前进 在不同的哮喘内型中表达。我们的长期目标是了解转录后基因 哮喘气道炎症不同内型的调节。这个应用程序的目标是我们 实现这一目标的下一步是确定 HuR 和 TTP 家族成员如何竞争性地监管 HuR 表达，进而控制哮喘中 CD4+ T 产生的细胞因子。我们的中心假设是 HuR 2 型高位哮喘的过度产生是由稳定 RBP 和不稳定 RBP 之间的不平衡造成的 作用于 Elavl1 mRNA，影响其稳定性和翻译。我们的数据表明 HuR 在 2 型哮喘 CD4+ T 细胞高，与正常对照和非 2 型相比高。此外，我们还有 结果表明，T 细胞中的条件性 HuR KO 可显着改善过敏原诱导的小鼠肺部炎症 模型。我们还证明 HuR 抑制可阻断哮喘 CD4+ T 细胞中 Th2/Th17 的分泌。 到目前为止，该领域主要关注下游 HuR 靶基因。相比之下，HuR 监管 不太理解。这项研究的基本原理是，拟议的研究将使我们能够确定 2 型高哮喘肺背景下驱动 HuR 过度产生的分子机制 炎。我们计划通过以下两个具体步骤来检验中心假设并实现这些目标 目的：1）确定HuR表达在气道炎症中的正常机制； 2) 确定分子 2 型高位哮喘中 HuR 失调的潜在机制。在完成拟议的研究后， 我们的预期结果是确定 HuR 和 TTP 如何合作来正常控制 HuR 表达以及如何 它们在 2 型高哮喘 CD4+ T 细胞中变得功能失调。这些结果预计将产生积极影响 对该领域的影响，因为它将进一步定义分子机制并提供发展机会 治疗哮喘的新疗法。