Toxicological Impact of Mine Tailings Dust on Developing and Adult Lung

项目总结(项目2；兰茨、博伊塔诺、鲁尼扬) 美国西南部干旱地区的粉尘，特别是遗留尾矿和冶炼厂的顺风向粉尘， 例如铁王矿和洪堡冶炼厂超级基金厂址(IKMHSS)，可能含有高水平的砷 和其他污染物。吸入这些粉尘会导致不良的健康后果。几乎没有数据存在 关于接触含砷粉尘的风险和砷之间的潜在相互作用 在水和灰尘暴露中摄入。上皮向间充质转化(EMT)对适当的器官至关重要 发育，在上皮伤口修复中也是重要的，并在疾病过程中发挥作用。中断 胚胎发育期间的胚胎移植会导致器官发育的改变，而成年人的改变则可能 导致伤口愈合功能障碍，包括上皮屏障功能丧失和上皮重塑 这会增加患呼吸系统疾病的风险。总体目标：确定毒理学反应 (EMT改变)到真实世界，周围存在的含砷粉尘吸入和/或砷摄取 遗留的矿场。我们将使用在IKMHSS现场收集的粉尘和模拟这些粉尘的暴露水平 在现场发现的。粉尘中的砷化合物的化学和物理性质(在项目5中分析)将 与毒性相关。假设：粉尘中的砷暴露会扰乱发育和胚胎发育过程中的EMT 这种EMT的改变会导致呼吸道功能障碍。三个特定的目标将在体外和在 活体模型，以确定暴露于砷和含砷粉尘对EMT的影响。特定的 目的1)应用xCELigence实时细胞分析(RTCA)筛选法检测含砷粉尘 导致细胞毒性的性质，并确定参与砷诱导的EMT中断的途径。 这将涉及一个高容量的测试系统，可以对大量样本进行毒性筛选。筛选 将指导吸入研究中的粉尘选择，并允许将粉尘特性与EMT变化相关联 和细胞毒性。明确目标2)确定砷暴露对肺气道发育的影响。 宫内和出生后早期暴露对成年小鼠肺功能和解剖的影响 发育情况将被评估，并与EMT途径基因表达的变化相关联。特定目标 3)采用原代细胞培养和活体实验研究砷对成人上皮细胞内皮细胞转移率的影响。 成年小鼠暴露于砷的体内和体外评估使用原代小鼠 将进行呼吸道上皮细胞的传导。发育阶段(目标2)和成人之间的反应 将比较反应(这一目的)，以确定类似的通路是否参与了砷诱导的EMT 在这两个不同的发育时期发生的暴露中断。因为现实世界的尘埃和 浓度将被使用，这些数据将有助于告知类似暴露对人类的风险。此外, 通过将体外和体内毒性测量与化学和物理表征相结合， 尘埃中的砷化合物，我们将能够确定尘埃砷的性质，以预测毒性。

PROJECT SUMMARY (Project 2; Lantz, Boitano, Runyan) Dusts in the arid Southwest of the United States, especially downwind of legacy mine tailings and smelters, such as the Iron King Mine and Humboldt Smelter Superfund site (IKMHSS), can contain high levels of arsenic and other contaminants. Inhalation of these dusts can lead to adverse health outcomes. Little data exist concerning the risk from exposure to arsenic containing dusts and the potential interactions between arsenic ingestion in water and dust exposures. Epithelial to mesenchymal transition (EMT) is vital for appropriate organ development, is also important in epithelial wound repair and plays a role in disease processes. Disruption of EMT during embryological development results in altered organ development while alterations in adults can result in dysfunctional wound healing that includes loss of epithelial barrier function and epithelial remodeling that increases risk for respiratory diseases. Overall Objective: To determine toxicological responses (alterations in EMT) to real world, arsenic containing dust inhalation and/or arsenic ingestion that exist around legacy mining sites. We will use dusts collected at the IKMHSS site and exposure levels that mimic those found at the site. Chemical and physical properties of arsenicals in the dusts (analyzed in Project 5) will be correlated with toxicity. Hypothesis: Dust borne arsenic exposure disrupts EMT both during development and in adults and this alteration in EMT results in airway dysfunction. Three Specific Aims will utilize in vitro and in vivo models to determine the effects of exposure to arsenic and arsenic containing dusts on EMT. Specific Aim 1) Use xCELLigence Real Time Cell Analysis (RTCA) screening to determine arsenic containing dust properties that cause cytotoxicity and to determine pathways involved in arsenic induced disruption of EMT. This will involve a high capacity test system that can screen large numbers of samples for toxicity. Screening will guide dust selection for inhalation studies and allow for correlation of dust properties with EMT changes and cellular toxicity. Specific Aim 2) Determine the effects of arsenic exposure on lung airway development. Alterations in lung function and anatomy in adult mice exposed during in utero and early postnatal development will be assessed and correlated with changes in EMT pathway gene expression. Specific Aim 3) Determine impact of arsenic on EMT in adult epithelium using primary cell cultures and in vivo measures. Adult mice will be exposed to arsenic where both in vivo and in vitro assessments using primary mouse conducting airway epithelial cells will be undertaken. Responses between developmental (Aim 2) and adult responses (this aim) will be compared to determine if similar pathways are involved in arsenic-induced EMT disruption for exposures occurring at these two distinct developmental times. Because real world dusts and concentrations will be used, these data will help to inform risk to humans from similar exposures. In addition, by combining in vitro and in vivo toxicity measurements with the chemical and physical characterization of arsenicals in the dust, we will be able to determine dust arsenical properties that predict toxicity.