Impact of particle and ozone inhalation co-exposure on alveolar epithelial regeneration

项目总结/摘要 环境吸入暴露本质上是混合的（气体和颗粒），但环境法规 仍然是基于单一的毒物接触在一个标准化的环境中开发和研究共同暴露情景， 和控制的方式将使更好地了解环境暴露如何导致 不良后果。共同暴露的影响研究得很少，特别是在易感人群中， 急性肺损伤（ALI）患者。在缺乏关于环境共同接触的知识的情况下， 如果不是不可能的话，也很难减轻环境疾病的负担， 作为保障公众健康的现实接触限值。本提案的目标是阐明 炭黑（CB;超细颗粒碳核的替代物）和臭氧（O3）吸入共同暴露- 诱导的肺损伤和调节上皮再生。我们将进一步机械化 描述线粒体核苷酸结合寡聚化结构域样受体X1（NLRX 1）在 这些回应。我们推测，共同暴露于CB和O3协同增加肺损伤 通过氧化颗粒表面，引起NLRX 1介导的线粒体功能障碍和微生物生态失调， 导致肺泡祖细胞（AT 2）重编程以改变肺泡再生。我们的研究 该计划专门结合了最先进的吸入共暴露，独特的小鼠模型和3-D类器官 培养以阐明健康和损伤肺中共同暴露诱导的肺损伤的机制 （一种易感性模型）。我们的初步研究表明，O3和CB吸入共同暴露 协同加重肺损伤、氧化应激、炎症、肺功能下降、肺渗透性 线粒体氧化磷酸化和肺微生物生态失调。小鼠 缺乏NLRX 1的小鼠在共同暴露后表现出显著加重的炎症反应。肺泡2型（AT2） 细胞（肺泡祖细胞）显示出显著的凋亡，线粒体损伤， 共暴露后的三维肺泡类器官。博莱霉素（BLM）诱导的肺上皮损伤显著 增加，而共同暴露后上皮细胞增殖受损。我们的具体目标是：（1）确定 协同生物活性和机制的肺部炎症后共同暴露，2）以确定如何 肺泡损伤和肺泡祖细胞功能障碍的改变机制有助于进展， ALI的结果，以及3）表征与或 没有阿里。这些研究将阐明遗传（NLRX 1）和细胞机制（肺泡祖细胞 线粒体功能障碍和微生物生态失调），环境暴露通过这些因素影响ALI 结果。这些发现将有助于了解联合暴露对肺部不良反应的影响 以及开展预防和治疗工作，以改善空气污染对健康的影响。

PROJECT SUMMARY/ABSTRACT Environmental inhalation exposures are inherently mixed (gases and particles), yet environmental regulations are still based on single toxicant exposures. Developing and studying the co-exposure scenario in a standardized and controlled fashion will enable a better mechanistic understanding of how environmental exposures result in adverse outcomes. The impact of co-exposures is poorly studied, especially in susceptible populations such as individuals with acute lung injury (ALI). In the absence of such knowledge on environmental co-exposures, it will be very difficult, if not impossible, to reduce the burden of environmental disease and develop effective as well as realistic exposure limits to safeguard public health. The goal of this proposal is to elucidate mechanisms of carbon black (CB; surrogate of the carbon core of ultrafine particles) and ozone (O3) inhalation co-exposure- induced lung injury and modulation of epithelial regeneration in mice following ALI. We will further mechanistically characterize the role of mitochondrial nucleotide-binding oligomerization domain-like Receptor X1 (NLRX1) in these responses. We hypothesize that co-exposure to CB and O3 synergistically increases pulmonary damage by oxidizing the particle surfaces, causing NLRX1 mediated mitochondrial dysfunction and microbial dysbiosis, leading to reprogramming of the alveolar progenitor (AT2) cells for altered alveolar regeneration. Our research plan exclusively combines state of the art inhalation co-exposures, unique mouse models, and 3-D organoid cultures to elucidate the mechanisms of co-exposure induced pulmonary damage in healthy and injured lungs (a susceptibility model). Our preliminary studies demonstrate that O3 and CB inhalation co-exposures synergistically exacerbates lung injury, oxidative stress, inflammation, lung function decline, lung permeability, mitochondrial oxidative phosphorylation, and lung microbial dysbiosis compared to individual exposures. Mice lacking NLRX1 exhibit significantly aggravated inflammatory response after co-exposure. Alveolar type 2 (AT2) cells (alveolar progenitor cells) show significant apoptosis, mitochondrial damage, and impaired ability to form 3-D alveolar organoids after co-exposure. Bleomycin (BLM)-induced lung epithelial injury is significantly increased, while epithelial proliferation is impaired after co-exposure. Our specific aims are 1) to determine synergistic biological activity and mechanisms of lung inflammation after co-exposure, 2) to identify how the altered mechanisms of alveolar injury and alveolar progenitor cell dysfunction contribute to progression and outcome of ALI, and 3) to characterize microbiome-alveolar progenitor cell cross-talk during co-exposure with or without ALI. These studies will delineate genetic (NLRX1) and cellular mechanisms (alveolar progenitor mitochondrial dysfunction and microbial dysbiosis) through which environmental exposures impact ALI outcomes. These findings will be helpful in understanding the impact of co-exposures on adverse lung effects and developing preventive and therapeutic efforts to ameliorate the health impact of air pollution.