Genetic and Longitudinal Analysis of Airway Remodeling

摘要 哮喘是一种慢性肺部疾病，可导致25岁以上患者的呼吸道狭窄和高反应性。 百万美国人。尽管有吸入性皮质类固醇治疗哮喘的现有方法，但显著未达到治疗效果 需求依然存在。呼吸道细胞和组织成分的变化，称为气道重塑， 预计会影响哮喘患者肺功能的下降。这些削减不能完全通过 现有的治疗方法，可导致致命哮喘发作时呼吸道粘液阻塞。虽然 许多遗传和环境因素导致哮喘的风险和严重程度，确定驱动因素 由于无法从大量的肺组织中提取样本，气道重塑仍然具有挑战性 并追踪随着时间的推移重塑的轨迹。气道重塑的分子调控机制研究进展 是更全面地理解哮喘发病机制的必要步骤，需要设计 有效的治疗方法。 这个项目将询问慢性呼吸道重塑的遗传和转录调节。 过敏原诱导的过敏性呼吸道疾病小鼠模型。这些分析将有力地定义这些关系 在重塑表型之间，确定新的治疗靶点，并跟踪重塑的发展和 进步。小鼠长期暴露于屋尘螨(HDM)变应原后，出现呼吸道症状 反映人类疾病的重塑，包括杯状细胞化生、上皮下纤维化和光滑 肌肉变厚。我将通过一项研究来研究这些重塑表型的机制 合作杂交(CC)小鼠群体的无偏全基因组方法。CC是一个小组，由 重组自交系，其中每一系的基因组代表八个创始菌株的独特马赛克 包括5个经典的近交系和3个野生来源的变异4500万单核苷酸的菌株 多态现象。这种遗传变异导致了不同菌株之间的高度表型变异，使得有可能 除了观察新的菌株外，在表型和基因变异之间建立联系 表型。我将量化30株慢性使用HDM和HDM治疗的CC菌株的气道重构表型 估计基因变异对重塑的贡献，这是更好地理解呼吸道的重要一步 重塑驱动因素，这在人类身上还不可能实现。此外，我将执行整个转录组 对呼吸道组织进行测序，并使用生物信息学方法确定候选转录调控因子 以粘液高分泌为重点的气道重塑表型。这些候选监管机构和 其他基因将在慢性HDM暴露的时间过程中进行评估，该过程跟踪HDM的启动和 重塑的进展。总之，这项建议的结果将进一步加深我们对呼吸道的理解 重塑机制以及重塑是如何随着时间的推移而发展的，为 寻找治疗哮喘的新靶向疗法。

ABSTRACT Asthma is a chronic lung condition that causes airway narrowing and hyperresponsiveness in over 25 million Americans. Despite available inhaled corticosteroid treatments for asthma, significant unmet therapeutic needs remain. Changes in the cellular and tissue composition of the airways, referred to as airway remodeling, are predicted to influence reduced lung function in asthmatics. These reductions cannot be fully resolved with available therapeutics and can lead to mucus occlusion of the airways seen in fatal asthma attacks. Although numerous genetic and environmental factors contribute to asthma risk and severity, identifying the drivers of airway remodeling remains challenging due to the inability to sample lung tissue from a large number of affected individuals and track remodeling over time. Elucidating the molecular regulators of airway remodeling is a necessary step toward a more comprehensive understanding of asthma pathogenesis required to design effective therapeutics. This project will interrogate the genetic and transcriptional regulation of airway remodeling in a chronic allergen-induced mouse model of allergic airway disease. These analyses will robustly define the relationships between remodeling phenotypes, identify novel therapeutic targets, and track remodeling development and progression. Upon chronic exposure to house dust mite (HDM) allergen, mice develop features of airway remodeling that mirror human disease, including goblet cell metaplasia, subepithelial fibrosis, and smooth muscle thickening. I will investigate the mechanisms underlying these remodeling phenotypes through an unbiased genome-wide approach with the Collaborative Cross (CC) mouse population. The CC is a panel of recombinant inbred lines where the genome of each line represents a unique mosaic of eight founder strains including five classical inbred and three wild-derived strains varying by 45 million single nucleotide polymorphisms. This genetic variation results in high phenotypic variability across strains, making it possible to make associations between phenotypic and genotypic variation, in addition to observing strains with novel phenotypes. I will quantify airway remodeling phenotypes in 30 CC strains chronically treated with HDM and estimate the contribution of genetic variation to remodeling, an important step in better understanding airway remodeling drivers that has not yet been possible in humans. Furthermore, I will perform whole transcriptome sequencing of airway tissue and use bioinformatic approaches to identify candidate transcriptional regulators of airway remodeling phenotypes with a specific focus on mucus hypersecretion. These candidate regulators and other genes will be evaluated in a time course of chronic HDM exposure that tracks the initiation and progression of remodeling. In summary, the results of this proposal will further our understanding of airway remodeling mechanisms and how remodeling is developed over time, providing a significant foundation for identifying new targeted therapeutics for asthma.!