Genetic Susceptibility to Nanoparticle-Induced Respiratory Disease

描述(申请人提供)：纳米技术的快速发展将伴随着数百万人接触到含有纳米材料的产品。碳纳米管(CNTs)是在原子水平上设计和修饰的一种主要的工程纳米材料，可用于多种用途(电子、工程、医学)。虽然碳纳米管有许多有益的用途，但也有强有力的证据表明，它们会导致小鼠和大鼠的肺损伤和呼吸系统疾病。一个主要的担忧是，碳纳米管具有一些类似于石棉的特性，石棉是一种与肺纤维化(组织疤痕形成)和间皮瘤(一种罕见的肺部胸膜表面癌症)的发展有关的纤维。我们发现，吸入的碳纳米管迁移到小鼠的胸膜(肺周围敏感的间皮衬里)，导致胸膜损伤和炎症。我们还报道了碳纳米管增加了预先暴露于过敏原或细菌脂多糖的小鼠的肺纤维化。在人类暴露变得广泛之前，了解碳纳米管如何导致小鼠呼吸道疾病，特别是纤维化和癌症，并确定易感因素以明确评估风险，这是至关重要的。这项建议的总体目标是利用基因工程小鼠对特定呼吸系统疾病的易感性模型来阐明CNT的毒性，特别是肺纤维化和间皮瘤。我们进一步试图确定通过原子层沉积(ALD)获得的选择性表面涂层是否影响碳纳米管缓解或加重这些呼吸道疾病的潜力。在这项建议中要检验的特定假设是，对CNT诱导的肺纤维化和间皮瘤的易感性是由于COX-2、STAT-1和P53之间的表达减少或功能相互作用受损。在目标1中，我们将确定COX-2是否介导了ALD-CNTs暴露后P53水平的升高，以及COX-2的缺失是否降低了暴露于ALD-CNTs的小鼠肺中的P53水平，从而导致纤维化或间皮瘤。在目标2中，我们将确定在暴露于ALD-CNTs后，STAT-1的激活是否诱导并激活P53，以及STAT-1的缺失是否会降低暴露于ALD-CNTs的小鼠肺中的P53，从而导致纤维化或间皮瘤。在目标3中，我们将确定在接触碳纳米管后，p53基因缺失的小鼠是否易患肺纤维化或间皮瘤，以及修饰碳纳米管的ALD是否会改变疾病结果。在目标4中，我们将确定ALD修饰的碳纳米管是否通过ROS激活MAPKs作为近端信号来诱导COX-2、STAT-1或P53，以及COX-2、STAT-1或P53的缺失是否放大了CNT诱导的MAPK信号。这一新方法将为碳纳米管引起呼吸道疾病的机制提供有价值的信息。此外，我们将确定特定的基因，其缺失将使个体因接触CNT而面临更大的风险。我们的方法还利用一种创新的跨学科方法来具体修改碳纳米管的表面化学，以确定毒性和疾病易感性是增加还是减少。对碳纳米管促进小鼠慢性肺部疾病的分子机制的新见解将提高我们对特定类型肺部疾病的易感性的理解。 这项工作的广泛影响将为设计更安全的纳米材料提供必要的信息，从而直接影响美国和世界各地数百万人的健康和福祉。

DESCRIPTION (provided by applicant): Rapid advances in nanotechnology will be accompanied by the exposure of millions of individuals to products containing nanomaterials. Carbon Nanotubes (CNTs) are a major type of engineered nanomaterial designed and modified at the atomic level for multiple uses (electronics, engineering, medicine). While there are many beneficial uses for CNTs, there is also strong evidence that they cause lung injury and respiratory disease in mice and rats. A major concern is that CNTs have some properties similar to asbestos, a fiber that is linked with the development of pulmonary fibrosis (tissue scarring) and mesothelioma (a rare cancer on the pleural surface of the lung). We discovered that inhaled CNTs migrate to the pleura (the sensitive mesothelial lining surrounding the lungs) in mice to cause pleural injury and inflammation. We have also reported that CNTs increase pulmonary fibrosis in mice pre-exposed to allergens or bacterial lipopolysaccharide. It is paramount to understand how CNTs cause respiratory diseases in mice, especially fibrosis and cancer, before human exposures become widespread and identify susceptibility factors to clearly evaluate risk. The overall goal of this proposal is to elucidate CNT toxicity using genetically engineered mouse models of susceptibility to specific respiratory diseases; specifically pulmonary fibrosis, and mesothelioma. We further seek to determine whether selective surface coatings achieved by atomic layer deposition (ALD), a novel technique of engineering nanoscale structures, affect the potential of CNTs to mitigate or exacerbate these respiratory diseases. The specific hypothesis to be tested in this proposal is that susceptibility to CNT-induced pulmonary fibrosis and mesothelioma is due to reduced expression or impaired functional interaction between COX-2, STAT-1, and p53. The following specific aims will be carried out to test this hypothesis: In Aim 1, we will determine whether COX-2 mediates increased p53 levels after exposure to ALD-CNTs and whether COX-2 deletion reduces p53 levels in the lungs of exposed mice to cause fibrosis or mesothelioma. In Aim 2, we will determine whether STAT-1 activation induces and activates p53 after exposure to ALD-CNTs and whether STAT-1 deletion reduces p53 in the lungs of exposed mice to cause fibrosis or mesothelioma. In Aim 3, we will determine whether p53-deficient mice are susceptible to pulmonary fibrosis or develop mesothelioma after exposure to CNTs and whether ALD modification of CNTs alters disease outcome. In Aim 4, we will determine whether ALD-modified CNTs activate MAPKs via ROS as a proximal signal to induce COX-2, STAT-1, or p53, and whether loss of COX-2, STAT-1, or p53 amplifies CNT-induced MAPK signaling. This novel approach will provide valuable information on mechanisms through which CNTs cause respiratory diseases. Moreover, we will identify specific genes whose deficiency will put individuals at greater risk resulting from CNT exposure. Our approach also takes advantage of an innovative cross-disciplinary approach to specifically modify the surface chemistry of carbon nanotubes to determine whether toxicity and disease susceptibility are increased or decreased. The new insights into the molecular mechanisms through which CNTs promote chronic lung disease in mice will improve our understanding of susceptibility to specific types of lung disease. The broad impact of this work will directly affect the health and well-being of millions of individuals in the U.S. and worldwide by providing essential information for the design of safer nanomaterials.