The Role of the EHF Transcription Factor in Lung Epithelial Function

 描述(申请人提供)：囊性纤维化(CF)是一种致命的遗传病，由囊性纤维化跨膜传导调节因子(CFTR)基因突变引起。这种疾病的主要死因是肺部病理，由中性粒细胞为主的炎症和其他侮辱引起。这种损伤会导致重塑和纤维化，导致肺功能障碍。肺部疾病的严重程度在携带CFTR相同突变的CF患者中有所不同，但正如双胞胎和兄弟姐妹研究所显示的那样，这些患者受到强大的基因控制。这暗示了CFTR基因外的基因修饰物在调节肺功能障碍中的作用。全基因组关联研究发现，位于染色体11p13区域的单核苷酸多态(SNPs)与CF患者的肺部疾病严重程度相关。这些SNP位于基因组的非编码区，表明它们影响附近基因的顺式作用调控元件。编码Ets同源因子(EHF)的基因位于该基因间隔区的5‘端。此外，11p13中的一个开放染色质区域与流行性出血热基因启动子的增强子相吻合。流行性出血热是一种转录因子，在许多上皮细胞中表达，包括气管和支气管内的那些衬里的上皮细胞，在这些细胞中，其表达被炎症介质增加。流行性出血热可作为基因激活剂或抑制物，尽管其在肺上皮细胞中的靶点在很大程度上尚不清楚。该提案的目的是在全基因组范围内确定流行性出血热的直接靶点，并确定流行性出血热在调节对肺部健康和疾病重要的细胞功能中的作用。该项目将验证流行性出血热通过调节参与炎症和上皮屏障维持的基因来控制肺上皮功能的假设。利用原代呼吸道上皮细胞，第一个目标的实验将通过识别EHF全基因组的结合位点并监测EHF耗竭后的差异基因表达来表征EHF的直接靶点。对这些目标的深入分析将确定受流行性出血热调节的生物途径。在第二个目标中，实验将研究与免疫相关的细胞功能的变化和EHF表达的调节反应上皮屏障的变化。免疫介质的释放和由此产生的中性粒细胞募集将在此背景下进行研究。流行性出血热在控制跨上皮耐药中的作用也将被研究。这项研究的结果将描述一种可能具有 在调节协调健康和疾病状态下肺功能的基因方面发挥重要作用。

 DESCRIPTION (provided by applicant): Cystic fibrosis (CF) is a lethal genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The major cause of death in this disorder is lung pathology, caused by neutrophil-dominant inflammation and other insults. This damage leads to remodeling and fibrosis, causing lung dysfunction. Severity of lung disease varies between CF patients carrying the same mutation in CFTR, but is under strong genetic control as shown by twin and sibling studies. This implicates a role for gene modifiers outside the CFTR locus in regulating lung dysfunction. A genome-wide association study (GWAS) identified single nucleotide polymorphisms (SNPs) on chromosome 11, in the 11p13 region, which associate with lung disease severity in CF patients. These SNPs lie in a non-coding region of the genome, suggesting that they impact cis-acting regulatory elements for nearby genes. The gene encoding ets homologous factor (EHF) maps to the 5' end of this intergenic region. Moreover, a region of open chromatin in 11p13 coincides with an enhancer of the EHF gene promoter. EHF is a transcription factor expressed in many epithelial cell types including those lining the airway within the trachea and bronchi, where its expression is increased by inflammatory mediators. EHF can act as a gene activator or repressor, though its targets in lung epithelial cells are largely unknown. The goal of this proposal is to characterize direct targets of EHF genome-wide, and to determine the role of EHF in regulating cell functions important for lung health and disease. This project will test the hypothesis that EHF controls lung epithelial function by regulating genes involved in inflammation and epithelial barrier maintenance. Using primary airway epithelial cells, experiments in the first aim will characterize direct targets of EHF by identifying binding sites for EHF genome-wide and monitoring differential gene expression following EHF depletion. In depth analysis of these targets will identify biological pathways regulated by EHF. In the second aim, experiments will investigate changes in cell functions relevant to immunity and the epithelial barrier in response to modulation of EHF expression. Immune mediator release and resulting neutrophil recruitment will be studied in this context. The role of EHF in control of transepithelial resistance will alsobe investigated. The outcome of this study will characterize a transcription factor that likely has an important role in regulating genes that coordinate lung function in health and disease states.