IL8-induced Post-transcriptional Regulation of the MUC5AC mucin gene

IL8 诱导的 MUC5AC 粘蛋白基因转录后调控

• 批准号: 7923924
• 负责人: Mary C Rose
• 金额: $ 21.5万
• 依托单位: CHILDREN'S RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7923924
• 关键词: 3' Untranslated Regions; A549; Abbreviations; Accounting; Asthma; Binding; Boxing; Bronchitis; Cell Line; Cells; Characteristics; Chronic Obstructive Airway Disease; Chronic lung disease; Complex; Cystic Fibrosis; Data; Development; Disease; Doctor of Philosophy; Double-Stranded RNA; Epithelial Cells; Event; Exposure to; Foundations; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Glycoproteins; Goblet Cells; Human; IL8 gene; Immune response; Inflammation; Inflammation Mediators; Inflammatory; Interleukin-8; Lead; Leukocyte Elastase; Location; Lung; Lung diseases; MUC5AC gene; Mediating; Mediator of activation protein; Messenger RNA; MicroRNAs; Molecular; Morbidity - disease rate; Mucins; Mucous body substance; Obstruction; Patients; Pharmacologic Substance; Polypyrimidine Tract-Binding Protein; Post-Transcriptional Regulation; Principal Investigator; Production; Protein Binding; Proteins; RNA-Binding Proteins; Recruitment Activity; Regulation; Reporting; Repression; Research; Research Project Grants; Respiratory System; Respiratory tract structure; Ribonucleoproteins; Role; Rosa; Site; Structure; System; Tail; Therapeutic Intervention; Toxic Environmental Substances; Transcript; Translations; Up-Regulation; airway epithelium; chemokine; mRNA Expression; mRNA Stability; macromolecule; mortality; novel; overexpression; pathogen; public health relevance

DESCRIPTION (provided by applicant): Secretory mucin glycoproteins are the major macromolecular component of lung mucus, which coats and protects the respiratory tract. Mucins are hypersecreted and overproduced in lung diseases, thereby contributing to airway mucus obstruction and to disease morbidity and mortality in patients with asthma, cystic fibrosis, and chronic obstructive pulmonary diseases. MUC5AC, a major airway mucin, is localized to goblet cells in the conducting airway epithelium and overexpressed in lung diseases. Our long term objective is to understand regulation of MUC5AC mucin gene expression at the molecular level in order to provide a better foundation for developing novel pharmaceutical agents to diminish mucin overproduction. The MUC5AC gene is regulated at the transcriptional and post-transcriptional level by specific inflammatory mediators. Mechanisms of transcriptional upregulation of the MUC5AC gene expression have been studied. However, post-transcriptional mechanisms of MUC5AC gene regulation are markedly understudied, but predictably are mediated by RNA binding proteins (RBPs) and/or microRNA (miRNAs), a newly identified mechanism for post- transcriptional regulation. The inflammatory mediator IL8 stabilizes MUC5AC mRNA abundance in lung cells and regulates MUC5AC at the post-transcriptional level. In this R21 project, we will focus on defining how the IL8-induced post-transcriptional regulation of MUC5AC gene expression is mediated by interactions induced by binding of RBPs, specifically PTB1 and candidate RBPs, and of Let-7 miRNA to target sequences in the 3'UTR of the MUC5AC mRNA. We will investigate mechanisms underlying these events in differentiated human bronchial epithelial cells and in the A549 lung cell line. In Aim 1 we will functionally evaluate the role of PTB1 in the IL8-induced stability of MUC5AC and identify and study additional candidate RBPs to determine whether they bind to cognate cis-sequences in the 3'UTR of MUC5AC after IL8 exposure to increase MUC5AC mRNA stability. In Aim 2 we will determine whether a Let-7 miRNA/micro-ribonucleprotein (mRNP) complex targets the 3'UTR of MUC5AC mRNA and recruits other miRNP to increase the stability of the MUC5AC transcript. This project will lay the groundwork to identify molecular mechanisms that regulate the stability of the MUC5AC transcript by inflammatory mediators to sustain mucin overproduction and hypersecretion during inflammation. PUBLIC HEALTH RELEVANCE: Secretory mucins are large, viscoelastic glycoproteins that are overproduced and hypersecreted in lung diseases. They contribute to airway mucus obstruction and to disease morbidity and mortality in patients with asthma, cystic fibrosis, and other chronic obstructive pulmonary diseases. MUC5AC is a predominant lung mucin and the MUC5AC gene is regulated by inflammatory mediators present in the lung secretions of patients. This project will investigate how the inflammatory mediator, IL8, mediates MUC5AC gene expression at the post-transcriptional level to increase MUC5AC stability and thus sustain MUC5AC production in lung cells during inflammatory states. Understanding the mechanisms whereby MUC5AC mRNA expression is stabilized by cellular factors following exposure to inflammatory factors will be important for understanding how mucin production is sustained n diseased airways. This will be fundamental for formulating therapeutic interventions for lung diseases that manifest with mucin overproduction.

描述（由申请人提供）：分泌性粘蛋白糖蛋白是肺粘液的主要大分子成分，其覆盖并保护呼吸道。粘蛋白在肺部疾病中过度分泌和过量产生，从而导致气道粘液阻塞以及哮喘、囊性纤维化和慢性阻塞性肺病患者的疾病发病率和死亡率。 MUC5AC 是一种主要气道粘蛋白，定位于传导气道上皮的杯状细胞，并在肺部疾病中过度表达。我们的长期目标是在分子水平上了解 MUC5AC 粘蛋白基因表达的调控，以便为开发减少粘蛋白过量产生的新型药物制剂提供更好的基础。 MUC5AC 基因在转录和转录后水平上受到特定炎症介质的调节。 MUC5AC 基因表达转录上调的机制已被研究。然而，MUC5AC 基因调控的转录后机制尚未得到充分研究，但可以预见的是，MUC5AC 基因调控的转录后机制是由 RNA 结合蛋白 (RBP) 和/或 microRNA (miRNA) 介导的，这是一种新发现的转录后调控机制。炎症介质 IL8 稳定肺细胞中 MUC5AC mRNA 丰度，并在转录后水平调节 MUC5AC。在这个 R21 项目中，我们将重点定义 IL8 诱导的 MUC5AC 基因表达转录后调控如何通过 RBP（特别是 PTB1 和候选 RBP）以及 Let-7 miRNA 与 MUC5AC mRNA 3'UTR 中的靶序列的结合诱导的相互作用来介导。我们将研究分化的人支气管上皮细胞和 A549 肺细胞系中这些事件的机制。在目标 1 中，我们将功能性评估 PTB1 在 IL8 诱导的 MUC5AC 稳定性中的作用，并鉴定和研究其他候选 RBP，以​​确定它们在 IL8 暴露后是否与 MUC5AC 3'UTR 中的同源顺式序列结合，以增加 MUC5AC mRNA 稳定性。在目标 2 中，我们将确定 Let-7 miRNA/微核糖核蛋白 (mRNP) 复合物是否靶向 MUC5AC mRNA 的 3'UTR 并招募其他 miRNP 以提高 MUC5AC 转录本的稳定性。该项目将为确定通过炎症介质调节 MUC5AC 转录物稳定性以维持炎症期间粘蛋白过量产生和分泌过多的分子机制奠定基础。公共健康相关性：分泌性粘蛋白是一种大的粘弹性糖蛋白，在肺部疾病中过量产生和过度分泌。它们会导致气道粘液阻塞，并导致哮喘、囊性纤维化和其他慢性阻塞性肺病患者的发病率和死亡率。 MUC5AC 是一种主要的肺粘蛋白，MUC5AC 基因受患者肺部分泌物中存在的炎症介质调节。该项目将研究炎症介质 IL8 如何在转录后水平介导 MUC5AC 基因表达，以增加 MUC5AC 稳定性，从而在炎症状态下维持肺细胞中 MUC5AC 的产生。了解暴露于炎症因子后细胞因子稳定 MUC5AC mRNA 表达的机制对于了解粘蛋白产生如何在患病气道中持续非常重要。这对于制定针对粘蛋白过量产生的肺部疾病的治疗干预措施至关重要。