HuR in Allergic Asthma

描述(申请人提供)：由于不明原因，哮喘的患病率和严重程度一直在增加。虽然我们对哮喘的病理生理机制的了解仍然很少，但人们普遍认为哮喘是一种炎症性疾病，而分泌Th2细胞因子的CD4+T细胞被认为是其发展的主要罪魁祸首。这些基因中有许多是转录后调控的，但它们的调控还不是很清楚。我们开发了一种新的范式，即转录后操纵子假说，该假说认为RNA结合蛋白正在协调调节生物相关分子的表达。我们的假设是，RNA结合蛋白HUR在过敏性气道炎症中协调调节Th2极化和细胞因子基因的表达。HUR是不稳定的mRNAs的主要稳定剂，在其3‘非翻译区含有富含AU的不稳定元素(ARE)。所有Th2细胞因子和90%的细胞因子和趋化因子都有ARs。1.确定HUR调节对淋巴细胞Th2极化和细胞因子产生的影响。我们将使用慢病毒载体在CD4+T细胞中低表达Hur，并检测Th1/Th2极化和细胞因子基因的表达。2.确定HUR高表达和低表达在小鼠过敏性气道炎症模型中的作用。我们将测试改变HUR水平是否会改善过敏性呼吸道炎症动物模型中哮喘的发展。3.HUR介导的过敏性炎症是否涉及microRNAs？我们将使用阵列从卵子致敏动物的肺中分离和鉴定microRNA。我们的方法将提供一个更全面的了解与哮喘相关的促炎基因的身份和调控。在转录后水平上更好地了解促炎基因调控可能会导致有针对性的治疗哮喘。与公共卫生相关：目前，全球过敏症和哮喘发病率和流行率不断上升的原因尚不清楚。在转录后基因调控和microRNAs方面令人兴奋的新发现可能会对我们对过敏原驱动的哮喘的理解产生广泛的影响。这项建议的目的是更好地了解细胞因子基因是如何在转录后水平上进行调控的。这将极大地帮助我们了解疾病的发病机制和治疗方法，并对公众健康产生直接影响。PHS 398/2590(09/04版)第15页续格式页

DESCRIPTION (provided by applicant): Asthma has been increasing in prevalence and severity for unknown reasons. Though our understanding of the pathophysiology remains poor, it is widely accepted that asthma is an inflammatory disease and CD4+ T cells elaborating Th2 cytokines have been identified as major culprits in its development. Many of these genes are posttranscriptionally regulated but their regulation is not well understood. We have developed a new paradigm, the posttranscriptional operon hypothesis, which states that RNA binding proteins are coordinately regulating the expression of biologically related molecules. Our hypothesis is that the RNA binding protein, HuR, is coordinately regulating Th2 polarization and cytokine gene expression in allergic airway inflammation. HuR is a major stabilizer of labile mRNAs containing AU rich instability elements (AREs) in their 3' untranslated regions. All the Th2 cytokines and 90% of cytokines and chemokines have AREs. 1. Determine effects of HuR modulation upon Th2 polarization and cytokine production in lymphocytes. We will employ lentiviral vectors to under-express HuR in CD4+ T cells and assay Th1/Th2 polarization and cytokine gene expression. 2. Determine role of HuR over-expression and under-expression in murine models of allergic airway inflammation. We will test whether altering HuR levels will modify asthma development in animal models of allergic airway inflammation. 3. Does HuR mediated allergic inflammation involves microRNAs? We will isolate and identify microRNAs from lungs of ova sensitized animals using arrays. Our approach will provide a fuller understanding of the identity and regulation of proinflammatory genes involved in asthma. Better understanding of proinflammatory gene regulation at the posttranscriptional level may potentially lead to targeted therapies to treat asthma. PUBLIC HEALTH RELEVANCE: The reasons for the increasing incidence and prevalence of allergies and asthma worldwide are presently unknown. Exciting new discoveries in posttranscriptional gene regulation and microRNAs potentially may have broad impacts on our understanding of allergen driven asthma. The aim of this proposal is to better understand how cytokine genes are regulated at the posttranscriptional level. This would greatly aid in our understanding of disease pathogenesis and treatment and have a direct impact on public health. PHS 398/2590 (Rev. 09/04) Page 15 Continuation Format Page