Epigenetic mechanisms of inflammatory memory propagation in human airway epithelia

项目摘要/摘要 哮喘和慢性支气管炎是全球死亡和住院的主要原因之一。 哮喘的慢性呼吸道炎症导致杯状细胞化生(GCM)、粘液高分泌和 呼吸道堵塞，导致呼吸衰竭和生活质量下降。收购和收购的机制 慢性炎症的持续性尚不清楚。目前对哮喘的抗炎治疗可以是 无效且不能治愈；慢性GCM在停止治疗后恢复。因此，有 迫切需要了解哮喘慢性炎症和GCM的发病机制。寄主遗传学 和环境都会导致哮喘；环境通过诱导免疫来促进哮喘 和呼吸道上皮细胞表观遗传记忆。呼吸道上皮中的基础干细胞可能获得表观遗传学 改变并起到记忆库的作用；当肺部发生细胞更替时，基底细胞补充 并可能传播炎性记忆，导致GCM。呼吸道上皮细胞的重要性 慢性肺部炎症的表观遗传记忆是一个新兴的研究领域。的中心假说 这一假设是，基础干细胞获得IL-13诱导的表观遗传学变化并传播炎症 记忆，因为它们有丝分裂地补充上皮，导致GCM和异常的上皮功能；我们计划 解决以下目标：特定目标1：确定IL-13诱导人类记忆的机制 采用转录、表观基因组和克隆型分析的大小呼吸道上皮细胞； 将确定IL-13诱导的记忆对GCM和呼吸道上皮细胞功能的影响。特定目标 2：检测哮喘患者鼻气道基底层细胞的表观遗传炎性记忆 使用鼻部刷牙和体外扩张；这将允许我们确定记忆是如何 哮喘患者基底细胞获得性参与GCM，哮喘患者的炎性记忆是否为IL-13- 干劲十足。具体目标3：研究气管-支气管内获得性表观遗传学改变 利用原代气管、支气管生物库，体内的基底细胞决定对IL-13的体外反应 由PI发育的基底细胞；我们将确定表观遗传、转录和表型记忆 上皮对IL-13诱导的GCM高度敏感，对IL-13诱导的GCM具有抵抗力。我们还将确定是否 针对GCM的药物可以逆转表观遗传记忆。随着这项提案的完成，我们预计将拥有 确定了A)新机制，B)治疗目标，以及C)生物标志物和精确医学战略 在哮喘患者和其他慢性炎症性肺部疾病中。这是治愈哮喘的第一步。 治疗。我们将进一步推动NHLBI的使命，将基本发现转化为临床实践，并 “增强所有人的健康，让他们活得更长、更有成就感。”

PROJECT SUMMARY / ABSTRACT Asthma and chronic bronchitis are among the top causes of death and hospitalizations worldwide. Chronic airway inflammation in asthma causes goblet cell metaplasia (GCM), mucus hypersecretion, and airway plugging, resulting in respiratory failure and poor quality of life. The mechanism for acquisition and persistence of chronic inflammation is not known. Current anti-inflammatory treatments for asthma can be ineffective and are not curative; chronic GCM resumes upon treatment discontinuation. Therefore, there is an urgent need to understand the mechanisms of chronic inflammation and GCM in asthma. Host genetics and the environment both contribute to asthma; the environment contributes to asthma by inducing immune and airway epithelial epigenetic memory. Basal stem cells in the airway epithelium may acquire epigenetic changes and act as a memory reservoir; as cellular turnover in the lungs occurs, basal cells replenish the epithelium and may propagate inflammatory memory, causing GCM. The importance of airway epithelial epigenetic memory in chronic lung inflammation is an emerging area of research. The central hypothesis of this proposal is that basal stem cells acquire IL-13-induced epigenetic changes and propagate inflammatory memory as they mitotically replenish the epithelium causing GCM and abnormal epithelial function; we plan to address the following aims: Specific Aim 1: Identify mechanisms of IL-13-induced memory in human large and small airway epithelia basal cells using transcriptomic, epigenomic, and clonotype analysis; we will determine the effect of IL-13-induced memory on GCM and function of airway epithelia. Specific Aim 2: Determine epigenetic inflammatory memory in asthmatic nasal airway basal cells obtained non- invasively using nasal brushings and in vitro expansion; this will allow us to determine how memory acquired by basal cells in asthma contribute to GCM, and whether inflammatory memory in asthma is IL-13- driven. Specific Aim 3: Investigate whether epigenetic changes acquired by tracheobronchial airway basal cells in vivo determine response to IL-13 in vitro leveraging a biobank of primary tracheobronchial basal cells developed by the PI; we will determine the epigenetic, transcriptional and phenotypic memory of epithelia highly susceptible to and epithelia resistant to IL-13-induced GCM. We will also determine whether drugs targeting GCM revert epigenetic memory. With the completion of this proposal, we expect to have identified A) novel mechanisms, B) treatment targets, and C) biomarkers and precision medicine strategies in asthmatics and other chronic inflammatory lung diseases. This is a first step to enable curative asthma treatments. We will further the NHLBI’s mission to “translate basic discoveries into clinical practice” and to “enhance the health of all individuals so that they can live longer and more fulfilling lives.”