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(申请人提供)：放射性肺纤维化(RiPF)是一种由放射治疗引发的“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。尽管在识别引起RPF的病理生理事件方面已经取得了进展，但关于导致这种辐射诱导的迟发效应的分子底物仍有很大的认识空白。我们的长期目标是确定调节RPF易感性的因素，并阐明其分子机制，以便最终设计出预防和/或减轻RPF的治疗策略。这个应用程序的目标是提供因素之间的机械联系 调节转化生长因子β1/Smad3信号转导和RiPF。我们的中心假设是转录因子核因子(红系衍生2)样蛋白2(NRF2)是调节转化生长因子的关键分子 ？调解的RiPF，这是基于我们初步和公布的数据。我们将用三个目标来检验这一假设。目的1验证Nrf2抑制转化生长因子β1/Smad3纤维化信号的工作假说。这一目的将决定Nrf2介导的对转化生长因子-1/Smad信号的抑制是针对促纤维化基因的一个子集，还是代表一种全局的抑制机制。芯片测序/生物信息学分析将用于在原代肺成纤维细胞和肺泡上皮II型(AET II)细胞中确定NRF2启动子在转化生长因子-1/Smad3调节的纤维化诱导基因的cagA位点的相互作用。体内实验将用于验证Nrf2和纤维化的转化生长因子-β信号之间的机制联系。目的2将确定胸部照射后肌成纤维细胞募集的来源，并测试募集是否依赖于Nrf2。纤维化的转化生长因子-β信号涉及复杂的电路。在这一目标中概述的研究集中在一个关键途径上：募集分泌胶原/基质的肌成纤维细胞，这是对肺纤维化发展至关重要的自我永久化细胞。然而，他们在RiPF的起源细胞并没有得到很好的描述。我们将使用CRE-LOX技术/细胞命运报告 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依赖于Nrf2。目的3将检验假设，即Nrf2缺乏会增加辐射引起的危及生命的肺损伤的发生。这一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缺乏症与表型联系起来。AIM 1的成功完成将为Nrf2信号确定一个新的范例。目的2将Nrf2信号与肌成纤维细胞的病理生理募集联系起来。目标3针对的是结果。这些目的有可能为RiPF提供新的机械性见解，最终导致预防或减轻RiPF的新治疗策略。