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: 7574935
• 负责人: Mary C Rose
• 金额: $ 25.8万
• 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 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7574935
• 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，它涂层并保护呼吸道。粘蛋白在肺部疾病中脱粒和产生过多，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部疾病的患者的疾病发病率和死亡率。 MUC5AC是一种主要的气道粘蛋白，被定位为导电上皮细胞的杯状细胞，并在肺部疾病中过表达。我们的长期目标是了解分子水平上MUC5AC粘蛋白基因表达的调节，以便为开发新型药物的粘蛋白过量生产提供更好的基础。 MUC5AC基因受特定的炎症介体在转录和转录后水平的调节。已经研究了MUC5AC基因表达的转录上调的机制。然而，MUC5AC基因调节的转录后机制被明显研究，但是可以预见，RNA结合蛋白（RBP）和/或microRNA（miRNA）介导，这是一种新鉴定的转录后调节机制。炎症介质IL8稳定肺细胞中的MUC5AC mRNA丰度，并在转录后水平调节MUC5AC。在这个R21项目中，我们将重点介绍IL8诱导的MUC5AC基因表达的转录后调控是如何由RBP的结合，特别是PTB1和候选RBP的结合引起的相互作用，以及MUC5AC mRNA 3''UTR中靶序列的let-7 miRNA介导的。我们将研究在分化的人支气管上皮细胞和A549肺细胞系中这些事件的基础机制。在AIM 1中，我们将在功能上评估PTB1在IL8诱导的MUC5AC稳定性中的作用，并识别和研究其他候选RBP，以​​确定它们在IL8暴露后与MUC5AC 3'UTR中的同源顺式序列结合，以提高MUC5AC mRNA稳定性。在AIM 2中，我们将确定Let-7 miRNA/微核核蛋白（MRNP）复合物是否针对MUC5AC mRNA的3'UTR并募集其他miRNP以提高MUC5AC转录本的稳定性。该项目将奠定基础，以确定通过炎症介质在炎症过程中通过炎症介质来调节MUC5AC转录物的稳定性的分子机制。公共卫生相关性：分泌性粘蛋白是大的粘弹性糖蛋白，它们在肺部疾病中产生过多和分泌过度。它们有助于气道粘液阻塞以及哮喘，囊性纤维化和其他慢性阻塞性肺部疾病的患者的疾病发病率和死亡率。 MUC5AC是一种主要的肺粘蛋白，MUC5AC基因受患者肺分泌物中存在的炎症介质的调节。该项目将调查炎症介质IL8如何在转录后水平上介导MUC5AC基因表达，以提高MUC5AC稳定性，从而在炎症状态下在肺细胞中维持MUC5AC的产生。了解MUC5AC mRNA表达在暴露于炎症因子后稳定的机制对于理解粘蛋白的产生如何持续N患病气道非常重要。这将是针对表现出粘蛋白过量生产的肺部疾病的治疗干预措施的基础。