Cytoplasmic-nuclear redox signaling: Disruption by dietary cadmium levels

描述（由申请人提供）：细胞质-核氧化还原信号传导：饮食镉水平的破坏我们最近对半胱氨酸蛋白质组氧化还原依赖性的研究表明，美国饮食中存在的镉（Cd）水平刺激硫氧还蛋白1（Trx 1）易位到细胞核中，并增强NF-κB的炎症信号传导。这些水平低于公认的毒性水平，因此必须谨慎对待结果。尽管如此，这一发现对健康有重大影响，因为炎症会导致许多慢性疾病。流行病学研究将低水平环境镉与肺癌、肺气肿和其他肺部疾病的风险以及心力衰竭和中风、骨质疏松症、贫血、生殖衰竭和其他癌症联系起来;对低水平镉和混杂变量的机械理解不足限制了这些发现在风险评估或政策决策中的应用。这个基础科学项目的目的是通过测试饮食镉水平通过破坏与肌动蛋白细胞骨架控制和核功能相关的氧化还原蛋白质组增强炎症性肺病的中心假设来提高对机制的理解。该项目是基于最近的进展，氧化还原敏感的细胞质-核信号，我们最近的数据氧化还原蛋白质组学的低剂量镉和大量的文献镉的生物效应。我们将使用分子和细胞的方法沿着与质谱为基础的氧化还原蛋白质组学研究镉破坏细胞质-核氧化还原系统在体外和体内肺部疾病模型。我们特别关注肺，因为氧化还原敏感性转录在肺功能，特别是炎症和纤维化中的核心作用，并且因为饮食镉的影响可以通过镉吸入而加剧。目的1探讨低剂量镉对氧化还原蛋白质组的影响机制。我们将测试的假设，镉对肌动蛋白细胞骨架蛋白的影响，导致易位的Trx 1到细胞核和刺激的转录因子调节炎症和纤维化反应的活动。目的2是确定低剂量镉是否通过影响核氧化还原信号增强促纤维化和促炎症机制。研究将使用肺疾病的体外细胞模型，分别使用博来霉素和H1N1流感病毒作为促纤维化剂和炎症剂。目的3使用与目的2平行的肺部疾病小鼠模型，以测试低剂量Cd是否通过影响体内核氧化还原控制系统和转录因子活性来增强炎症和纤维化信号传导;目的还包括对人类肺部样本的研究，以允许 模型系统对人肺镉含量的直接校正。这些结果将表明，镉暴露在美国饮食中发现的水平是否会对炎症和纤维化的细胞质-核细胞信号传导机制产生不利影响。如果是这样的话，全球蛋白质组学和转录组学数据，沿着校准的炎症和纤维化标志物的镉依赖性，将为人类饮食镉健康风险的有针对性的评估提供必要的数据。

DESCRIPTION (provided by applicant): Cytoplasmic-nuclear redox signaling: Disruption by dietary cadmium levels Our recent research on the redox dependence of the cysteine proteome shows that levels of cadmium (Cd) present in the American diet stimulate translocation of thioredoxin-1 (Trx1) into cell nuclei and potentiate inflammatory signaling by NF-κB. These levels are below recognized toxic levels and so the results must be approached with caution. None-the-less, the finding has substantial health implications because inflammation contributes to many chronic diseases. Epidemiologic studies associate low-level environmental Cd to the risk of lung cancer, emphysema and other lung diseases, as well as heart failure and stroke, osteoporosis, anemia, reproductive failure and other cancers; poor mechanistic understanding of low-level Cd and confounding variables limit use of these findings in risk assessment or policy decisions. The purpose of this basic science project is to improve mechanistic understanding by testing the central hypothesis that dietary Cd levels potentiate inflammatory lung disease through disruption of the redox proteome associated with actin cytoskeleton control and nuclear function. The project is based upon recent advances in redox-sensitive cytoplasmic-nuclear signaling, our recent data on redox proteomics of low-dose Cd and an extensive literature on biologic effects of Cd. We will use molecular and cellular methods along with mass spectrometry-based redox proteomics to study Cd disruption of cytoplasmic-nuclear redox systems in in vitro and in vivo lung disease models. We specifically focus on the lung because of the central role of redox-sensitive transcription in lung function, especially inflammation and fibrosis, and because dietary Cd effects can be exacerbated by Cd inhalation. Aim 1 is to investigate mechanisms of low-dose Cd on the redox proteome. We will test the hypothesis that Cd effect on actin cytoskeleton proteins causes translocation of Trx1 into nuclei and stimulates activity of transcription factors regulating inflammation and fibrotic responses. Aim 2 is to determine whether low-dose Cd potentiates profibrosis and proinflammation mechanisms by affecting nuclear redox signaling. Studies will use in vitro cell models of pulmonary diseases using bleomycin and H1N1 influenza virus for profibroitc and inflammatory agents, respectively. Aim 3 uses mouse models of pulmonary disease paralleling Aim 2, to test whether low-dose Cd potentiates inflammatory and fibrotic signaling by affecting nuclear redox control systems and transcription factor activity in vivo; the Aim also includes studies of human lung samples to allow direct calibration of model systems to human lung Cd contents. These results will show whether Cd exposures at levels found in the American diet adversely impacts the mechanisms of cytoplasmic-nuclear cell signaling of inflammation and fibrosis. If so, the global proteomic and transcriptomic data, along with calibrated Cd-dependence of markers of inflammation and fibrosis, will provide essential data for targeted evaluation of dietary Cd health risks in humans.