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）：放射性肺纤维化（RiPF）是由放射治疗引发的“晚期正常组织肺损伤”，可导致癌症幸存者的显著发病率和死亡率。虽然在识别引起RiPF的病理生理学事件方面取得了进展，但关于这种辐射诱导的迟发效应的分子基础的知识仍存在很大差距。我们的长期目标是鉴定调节RiPF易感性的因素并阐明其分子机制，以便最终设计用于预防和/或减轻RiPF的治疗策略。本申请的目的是提供因素之间的机械联系 调节TGF-β 1/Smad 3信号和RiPF。我们的中心假设是，转录因子核因子（红细胞衍生2）样2（Nrf 2）是调节TGF的关键分子 介导的RiPF，这是基于我们的初步和公开的数据。三个目标将被用来测试这一假设。目的1将测试Nrf 2抑制TGF-β 1/Smad 3纤维化信号传导的工作假设。这一目标将确定Nrf 2介导的TGF-β 1/Smad信号转导的抑制是否对促纤维化基因的子集具有特异性，或者是否代表了一种全面的抑制机制。将使用ChIP测序/生物信息学分析来鉴定原代肺成纤维细胞和肺泡上皮II型（AET II）细胞中TGF-β 1/Smad 3调节的纤维化诱导基因中CAGA位点的Nrf 2-启动子相互作用。体内实验将B验证Nrf 2和纤维化TGF-β信号传导之间的机制联系。目的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Nrf 2。纤维化TGF-β信号传导涉及复杂的电路。在这一目标中概述的研究集中在一个关键途径：胶原蛋白/基质分泌肌成纤维细胞，自我永存细胞的发展肺纤维化的关键招募。然而，它们在RiPF中的起源细胞还没有得到很好的表征。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募集是否是Nrf 2依赖性的。目的3将检验Nrf 2缺乏会增加辐射诱导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Nrf 2小鼠来解决这一概念验证。目标是将细胞特异性Nrf 2缺陷与表型相关。目标1的成功完成将为Nrf 2信号转导确定一个新的范例。目的2将Nrf 2信号传导与肌成纤维细胞的病理生理募集联系起来。目标3涉及成果。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。