Nrf2 and Radiation-induced pulmonary fibrosis.

Nrf2 和辐射诱导的肺纤维化。

• 批准号: 8606883
• 负责人: MICHAEL L. FREEMAN
• 金额: $ 42.92万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8606883
• 关键词: Address; Adverse effects; Affect; Alveolar; Bioinformatics; Bleomycin; Bone Marrow; CCL3 gene; CCR1 gene; Cancer Survivor; Cells; Cessation of life; ChIP-seq; Chest; Chimera organism; Collagen; Complex; Data; Development; Dose-Limiting; Epithelial; Erythroid; Event; Exhibits; Fibroblasts; Fibrosis; Genes; Genetic; Genetic Engineering; Genetic Transcription; Goals; Human; Injury; Knockout Mice; Knowledge; Late Effects; Life; Link; Lung; Lung diseases; Lysophospholipids; Mediating; Modeling; Molecular; Morbidity - disease rate; Mus; Myofibroblast; Normal tissue morphology; Nuclear; Outcome; Oxidative Stress; Pathway interactions; Patients; Phenotype; Plasminogen Activator Inhibitor 1; Predisposition; Production; Proteins; Publishing; Pulmonary Fibrosis; Radiation; Radiation therapy; Reporter; Repression; Research; Risk; S100A8 gene; Signal Transduction; Site; Technology; Testing; Therapeutic; Time; Type II Epithelial Receptor Cell; Wild Type Mouse; Work; base; connective tissue growth factor; in vivo; insight; irradiation; lung injury; lysophosphatidic acid; mortality; mouse model; novel; novel therapeutics; prevent; promoter; public health relevance; transcription factor

DESCRIPTION (provided by applicant): Radiation-induced pulmonary fibrosis (RiPF) is a 'late normal tissue lung injury' initiated by radiation therapy and can result in significant morbidity ad mortality among cancer survivors. Although progress has been made toward identifying pathophysiological events that give rise to RiPF, there is a substantial gap in knowledge regarding the molecular under-pinnings responsible for this radiation-induced late effect. Our long- term goal is to identify factors that regulate RiPF susceptibility and elucidate their molecular mechanisms in order to ultimately devise therapeutic strategies for preventing and/or mitigating RiPF. The objective of this application is to provide a mechanistic link between factors that regulate TGF-¿1/Smad3 signaling and RiPF. Our central hypothesis is that the transcription factor Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a critical molecule for regulating TGF ¿-mediated RiPF and this is based on our preliminary and published data. Three aims will be used to test this hypothesis. Aim 1 will test the working hypothesis that Nrf2 repressesTGF-¿1/Smad3 fibrogenic signaling. This aim will determine if Nrf2-mediated repression of TGF- ¿1/Smad signaling is specific for a subset of profibrotic genes or represents a global mechanism of repression. A ChIP-sequencing/bioinformatics analysis will be used to identify Nrf2-promoter interactions at CAGA sites in TGF-¿1/Smad3-regulated fibrosis-inducing genes in primary pulmonary fibroblast and alveolar epithelial type II (AET II) cells. In vivo experimentation will b used to validate a mechanistic link between Nrf2 and fibrotic TGF-¿ signaling. Aim 2 will determine the origin of myofibroblast recruitment following thoracic irradiation and test whether recruitment is Nrf2 dependent. Fibrotic TGF-¿ signaling involves complex circuitry. Research outlined in this aim focuses on a key pathway: recruitment of collagen/matrix secreting myofibroblasts, self perpetuating cells critical for development of pulmonary fibrosis. Yet their cell-of-origin in RiPF is not well characterized. We will use Cre-lox technology/cell fate reporter mice and bone marrow chimera experimentation to determine the contribution of resident fibroblasts, AET II cells, and bone marrow- derived fibrocytes to myofibroblast formation and whether recruitment is Nrf2 dependent. Aim 3 will test the hypothesis that an Nrf2 deficiency increases the occurrence of radiation-induced life-threatening pulmonary injury. This aim will use genetically engineered Nrf2 mice to address this proof of concept. The goal is to relate a cell-specific Nrf2 deficiency with phenotype. Successful completion of Aim 1 will identify a new paradigm for Nrf2 signaling. Aim 2 will connect Nrf2 signaling with pathophysiological recruitment of myofibroblasts. Aim 3 addresses outcome. These aims have the potential to provide novel mechanistic insights into RiPF, leading eventually to new therapeutic strategies for preventing or mitigating RiPF.

描述（由申请人提供）：辐射诱发的肺纤维化（RiPF）是由放射治疗引起的“晚期正常组织肺损伤”，可导致癌症幸存者显着的发病率和死亡率。尽管在识别引起 RiPF 的病理生理学事件方面已经取得了进展，但关于导致这种辐射诱导的晚期效应的分子基础的知识还存在很大差距。我们的长期目标是确定调节 RiPF 易感性的因素并阐明其分子机制，以便最终设计预防和/或减轻 RiPF 的治疗策略。该应用程序的目的是提供因素之间的机械联系 调节 TGF-¿1/Smad3 信号传导和 RiPF。我们的中心假设是转录因子核因子（红细胞衍生 2）样 2 (Nrf2) 是调节 TGF 的关键分子 ¿ 介导的 RiPF，这是基于我们的初步和已发布的数据。将使用三个目标来检验这一假设。目标 1 将检验 Nrf2 抑制 TGF-¿1/Smad3 纤维化信号传导的工作假设。这一目标将确定 Nrf2 介导的 TGF-β1/Smad 信号传导抑制是否对促纤维化基因的子集具有特异性，或者是否代表了全局抑制机制。 ChIP 测序/生物信息学分析将用于鉴定原代肺成纤维细胞和 II 型肺泡上皮 (AET II) 细胞中 TGF-¿1/Smad3 调节的纤维化诱导基因中 CAGA 位点的 Nrf2 启动子相互作用。体内实验将用于验证 Nrf2 和纤维化 TGF-¿ 信号传导之间的机制联系。目标 2 将确定胸部照射后肌成纤维细胞募集的起源，并测试募集是否依赖于 Nrf2。纤维化 TGF-¿ 信号传导涉及复杂的电路。该目标概述的研究重点关注一个关键途径：分泌胶原/基质的肌成纤维细胞的募集，这是对肺纤维化发展至关重要的自我永存细胞。然而，它们在 RiPF 中的起源细胞尚未得到很好的表征。我们将使用Cre-lox技术/细胞命运报告器 小鼠和骨髓嵌合体实验以确定常驻成纤维细胞、AET II 细胞和骨髓来源的纤维细胞对肌成纤维细胞形成的贡献以及招募是否依赖于 Nrf2。目标 3 将检验 Nrf2 缺乏会增加辐射引起的危及生命的肺损伤发生率的假设。该目标将使用基因工程 Nrf2 小鼠来解决这一概念验证问题。目标是将细胞特异性 Nrf2 缺陷与表型联系起来。目标 1 的成功完成将为 Nrf2 信号传导确定新的范例。目标 2 将 Nrf2 信号传导与肌成纤维细胞的病理生理招募联系起来。目标 3 涉及结果。这些目标有可能为 RiPF 提供新的机制见解，最终导致预防或减轻 RiPF 的新治疗策略。