The Functional Consequences of the 17q12 Asthma Susceptibility Locus

17q12 哮喘易感基因座的功能后果

基本信息

批准号：
9113682
负责人：
Benjamin Alexander Raby
金额：
$ 84.58万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9113682
关键词：
17q12 Albuterol Allergens Asthma Binding Proteins Bronchodilator Agents CD4 Positive T Lymphocytes Cell physiology Cells Chemosensitization Chromosomes Data Development Disease Enzymes Epithelial Epithelial Cells Ethnic Origin Extrinsic asthma Foundations Gene Expression Genes Genetic Genotype Glucosylceramides Haplotypes Health Human In Vitro Individual Inflammatory Knowledge Liquid substance Lung Measures Mediating Mediator of activation protein Metabolic Metabolism Molecular Mus Pathogenesis Physiological Plasma Predisposition Production Resolution Risk Sampling Serine Severity of illness Sphingolipids Susceptibility Gene Testing Time Transferase Transgenic Mice Transgenic Organisms Up-Regulation Variant Zona Pellucida airway hyperresponsiveness airway inflammation allergic airway inflammation asthmatic bronchial epithelium cell type chromatin remodeling cytokine genetic association genetic variant genome wide association study human data in vivo knock-down methacholine mouse model novel overexpression promoter response

项目摘要

DESCRIPTION (provided by applicant): The objective of this proposal is to identify the asthma gene that is responsible for the genetic associations on chromosome 17q12 with asthma. A common haplotype on chromosome 17q12 is the strongest, most consistently reproducible asthma-susceptibility locus to emerge from genome-wide association studies. The 17q12 asthma-risk haplotype confers regional chromatin remodeling of three neighboring genes: ORMDL3, GSDMB, and ZPBP2. However, from the available genetic data alone, it is impossible to conclude with any certainty which of these three is responsible for the genetic association. From our preliminary data, we observe that both ORDML3 and GSDMB are constitutively expressed in bronchial epithelium, and that their overexpression results in discrete molecular and cellular consequences of importance in asthma. In contrast, we find that ZPBP2 is not expressed in either bronchial epithelium or other asthma-relevant cell types. We thus hypothesize that ORMDL3 or GSDMB, but not ZPBP2, confers asthma risk. To test this hypothesis, we propose three Specific Aims. In Specific Aim 1, we will study inducible transgenic mice generated in our lab that conditionally over express ORMDL3 or GSDMB in bronchial epithelium. We will assess the effects of each gene's over expression in an established murine model of allergic asthma, examining the physiological, histological, and metabolic consequences. In Specific Aim 2, we will experimentally assess (via in vitro knockdown and over expression studies) the independent cellular consequences of ORMDL3 and GSDMB expression in human bronchial epithelial cells derived from individuals homozygous for the risk and protective 17q12 haplotypes. In Specific Aim 3, we will study the relationship of 17q12 haplotype with sphingolipid metabolism in several ways (i) we will measure sphingolipid levels in the airways & lung homogenates from our murine studies in Aim 1 to determine the in vivo effects of ORMDL3 expression; (ii) we will examine by genetic association whether the functional 17q12 regulatory variant contributes to variations in plasma sphingolipid levels in 200 asthmatics; and (iii) we will correlate these plasma sphingolipid levels with bronchodilator response to albuterol and airways hyperreactivity to methacholine. The knowledge gained through these proposed efforts will advance our understanding of this most important asthma-susceptibility locus, and will provide the requisite foundations for the development of novel asthma therapies.

描述（由适用提供）：该提案的目的是确定哮喘基因，该基因是导致染色体17q12与哮喘的遗传关联的原因。 17q12染色体上的一种常见单倍型是强的，最始终可再现的哮喘抑制性基因座，从全基因组关联研究中出现。 17q12哮喘风险单倍型赋予了三个相邻基因的区域染色质重塑：ORMDL3，GSDMB和ZPBP2。但是，仅凭可用的遗传数据，就不可能确定任何三个造成遗传关联的任何确定性。从我们的初步数据中，我们观察到ORDML3和GSDMB始终在支气管上皮中表达，并且它们的过表达导致离散哮喘重要性的分子和细胞后果。相反，我们发现ZPBP2在支气管上皮或其他与哮喘相关的细胞类型中均未表达。因此，我们假设ORMDL3或GSDMB（而不是ZPBP2）赋予了哮喘风险。为了检验这一假设，我们提出了三个具体目标。在特定的目标1中，我们将研究在我们的实验室中产生的诱导转基因小鼠，这些小鼠在支气管上皮中有条件的ORMDL3或GSDMB有条件。我们将在既定的过敏性哮喘的鼠模型中评估每个基因的过度表达的影响，从而检查物理，组织学和代谢后果。在特定目标2中，我们将通过实验评估（通过体外敲低和过度表达研究）在人支气管上皮细胞中ORMDL3和GSDMB表达的独立细胞后果，这些细胞源自纯合子的个体风险并保护17q12单倍型。在特定目标3中，我们将研究17q12单倍型与鞘脂代谢的关系（i）我们将在AIM 1中从鼠研究中测量气道和肺匀浆中的鞘脂水平，以确定ORMDL3表达的体内效应；（ii）我们将通过遗传关联检查功能性17q12调节变体是否有助于200哮喘患者血浆鞘脂水平的变化；（iii）我们将关联这些等离子体鞘脂水平用支气管扩张剂对偶然酚和气道对方法的反应性过高的反应。通过这些拟议的努力获得的知识将促进我们对这个最重要的哮喘启发性基因座的理解，并将为开发新型哮喘疗法提供必要的基础。