DNA-Damage Repair In Pulmonary Fibrosis

肺纤维化中的 DNA 损伤修复

• 批准号: 9013893
• 负责人: Jonathan Andrew Kropski
• 金额: $ 3.73万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9013893
• 关键词: 3-Dimensional; Abnormal DNA Repair; Affect; Age; Alveolar; Bioinformatics; Bleomycin; Cell Cycle; Cell Cycle Arrest; Cell Cycle Checkpoint; Cell Cycle Progression; Cell Line; Cell Proliferation; Cell Survival; Cell model; Cells; Clinical; Complex; DNA Damage; DNA Repair; DNA Repair Pathway; Data; Development; Disease; Epithelial; Epithelial Cells; Family; Fibrosis; Functional disorder; Genes; Genetic Risk; Hamman-Rich syndrome; Histopathology; Homologous Gene; Injury; Interstitial Pneumonia; Investigation; Length; Leukocytes; Link; Lymphocyte; Mediating; Modeling; Mus; Mutation; Pathogenesis; Pathway interactions; Patients; Play; Predisposition; Pulmonary Fibrosis; Role; Signal Transduction; Suggestion; Syndrome; TP53 gene; Telomerase; Telomere Shortening; Testing; alveolar epithelium; base; exome sequencing; genetic risk factor; genetic variant; helicase; insight; kindred; loss of function; loss of function mutation; mouse model; peripheral blood; programs; public health relevance; rare variant; repaired; response; response to injury; telomere

 DESCRIPTION (provided by applicant): Up to 20% of idiopathic pulmonary fibrosis cases (IPF) are familial, comprising a syndrome known as Familial Interstitial Pneumonia (FIP). Short peripheral blood telomere length has been associated with sporadic IPF and FIP, and rare loss of function mutations in telomerase complex genes have been found in 15-20% of FIP families, however, investigations to date regarding the mechanisms linking telomerase dysfunction and telomere shortening with lung fibrosis have been largely unrevealing. Using whole-exome sequencing, we have recently identified loss-of-function mutations in regulator of telomere elongation helicase (RTEL1) that segregated with disease in 15 FIP families, and our preliminary data suggest impaired RTEL1 function leads to inefficient repair of DNA-damage in alveolar epithelial cells (AECs), leading to activation of p53 mediated cell- cycle arrest signalin programs that may contribute to AEC dysfunction in the context of pulmonary fibrosis. Using bioinformatics approaches, we identified a large group of FIP families (>50%) that carry rare variants in other genes related to cell cycle, DNA damage-repair, and p53 signaling, suggesting that abnormalities in these interrelated pathways may underlie genetic risk for a large subset of FIP families. In this proposal, we hypothesize that loss-of-function genetic variants in FIP-associated genes (including RTEL1) predispose to pulmonary fibrosis by altering DNA-damage repair and activating p53-mediated cell-cycle checkpoint arrest signaling in alveolar epithelial cells, resulting in impaired re-epithelialization following injury and progressive fibrotic remodeling. Our specific aims are: (1) To determine the role of Rtel in experimental lung fibrosis. (2) To determine the mechanisms through which RTEL1 regulates DNA damage-repair and cell survival/proliferation in response to injury, and (3) To determine whether DNA damage-repair capacity is altered in a large subset of FIP families and patients with sporadic IPF. To accomplish these aims, we will utilize Rtel deficient mouse models, RTEL1 deficient cell lines, primary cells from Rtel deficient mice, and primary cells from FIP and IPF patients. Together, these studies hold the promise of elucidating the role of DNA-damage repair and signaling in the development of pulmonary fibrosis, thus adding important new insights into disease pathogenesis.

 描述（由申请人提供）：高达20%的特发性肺纤维化病例（IPF）是家族性的，包括称为家族性间质性肺炎（FIP）的综合征。外周血端粒长度短与散发性IPF和FIP相关，并且在15-20%的FIP家族中发现了端粒酶复合物基因的罕见功能缺失突变，然而，迄今为止关于端粒酶功能障碍和端粒缩短与肺纤维化相关的机制的研究在很大程度上尚未揭示。使用全外显子组测序，我们最近在15个FIP家族中鉴定了端粒延伸解旋酶（RTEL 1）调节因子的功能缺失突变，这些突变与疾病分离，我们的初步数据表明，受损的RTEL 1功能导致肺泡上皮细胞（AEC）中DNA损伤的修复效率低下，导致p53介导的细胞周期阻滞信号程序的激活，这可能有助于肺纤维化背景下的AEC功能障碍。使用生物信息学方法，我们确定了一大组FIP家族（>50%），这些家族携带与细胞周期，DNA损伤修复和p53信号传导相关的其他基因的罕见变异，这表明这些相关通路的异常可能是FIP家族大子集的遗传风险的基础。在这个提议中，我们假设FIP相关基因（包括RTEL 1）中的功能丧失遗传变异通过改变肺泡上皮细胞中DNA损伤修复和激活p53介导的细胞周期检查点阻滞信号而易患肺纤维化，导致损伤后上皮再形成受损和进行性纤维化重塑。我们的具体目的是：（1）研究Rtel在实验性肺纤维化中的作用。(2)确定RTEL 1调节DNA损伤修复和细胞存活/增殖以响应损伤的机制，以及（3）确定DNA损伤修复能力是否在FIP家族和散发性IPF患者的大子集中改变。为了实现这些目标，我们将利用Rtel缺陷型小鼠模型、RTEL 1缺陷型细胞系、来自Rtel缺陷型小鼠的原代细胞以及来自FIP和IPF患者的原代细胞。总之，这些研究有望阐明DNA损伤修复和信号传导在肺纤维化发展中的作用，从而为疾病发病机制提供重要的新见解。