Nanoparticle Fibrogenicity and Fibroblast Stem-Like Cells

 描述(申请人提供)：包括碳纳米管(CNTs)在内的工程异型材料已成为最重要的新材料类别之一，具有创造新的和更好的产品的巨大潜力。越来越多的证据表明，肺暴露于碳纳米管会导致肺纤维化，这是一种无法治愈的胎儿肺部疾病，目前尚无有效的治疗方法。该项目的长期目标是通过了解纤维形成的潜在机制和确定控制纳米材料的纤维形成效应的关键物理化学因素来实现安全的纳米技术。不断发展的研究表明，具有无限增殖潜力的成纤维细胞干细胞(FSCs)可能是纤维化的驱动力，但其潜在机制及其在CNT纤维化形成中的作用尚不清楚。我们已经获得突破性的证据表明，碳纳米管能够诱导具有激活的成纤维细胞功能表型的FSCS，这种表型负责细胞外基质的积累，这是肺纤维化的标志。我们假设碳纳米管通过一个涉及FSC诱导的过程来诱导肺纤维化，并且这种诱导依赖于碳纳米管的特定物理化学性质。本文提出了三个具体的目标来检验这些假设。在目标1中，我们将表征碳纳米管处理的成纤维细胞和动物中的FSC获取，并确定它们在纤维化形成中的作用。目的2将建立三维高通量成纤维细胞结节模型，用于定量评估CNT的纤维原性，并记录CNT特性对FSC获取和纤维化形成的影响。这一目标还将识别特定的FSC生物标记物，并在动物身上验证体外模型。Aim 3将研究FSC发育和纤维化形成的氧化还原调节，并确定参与这一过程的特定氧化物种和关键调节酶。我们的期望是，在本项目结束时，我们将确定FSCS在CNT纤维化形成中的作用，并确定影响其纤维性的CNT的特定生物标志物和关键物理化学性质。这项工作之所以重要，是因为它将对安全纳米材料的发展以及对纳米材料引起的纤维化的风险评估、早期发现和预防产生整体影响。我们预计这一影响将是广泛的，因为该项目的发现非常适用于其他致纤维化药物、纳米材料和外源物质。这项拟议的工作具有创新性，因为它是第一次研究胚胎干细胞及其在纤维化中的作用。它还将开发新的实验模型和测试方法，以快速评估纳米材料的纤维原性，并在各种干细胞应用中发挥潜在的作用。

 DESCRIPTION (provided by applicant): Engineered anomaterials including carbon nanotubes (CNTs) have emerged as one of the most important classes of new materials having enormous potential to create new and better products. Accumulating evidence indicates that pulmonary exposure to CNTs induces lung fibrosis, a fetal and incurable lung disease with no known effective treatments. The long-term objective of this project is to enable safe nanotechnology through the understanding of underlying mechanisms of fibrogenesis and determining key physicochemical factors controlling the fibrogenic effect of nanomaterials. Evolving research indicates that fibroblast stem cells (FSCs) with unlimited proliferative potential are likely a driing force of fibrosis, but the underlying mechanisms and their role in CNT fibrogenesis are not known. We have obtained breakthrough evidence showing the ability of CNTs to induce FSCs with a functional phenotype of activated fibroblasts that are responsible for extracellular matrix accumulation, a hallmark of lung fibrosis. We hypothesize that CNTs induce lung fibrosis through a process that involves FSC induction and that such induction is dependent on specific physicochemical properties of CNT. Three specific aims are proposed to test the hypotheses. In Aim 1, we will characterize FSC acquisition in CNT-treated fibroblasts and animals and determine their role in fibrogenesis. Aim 2 will develop 3D high-throughput fibroblastic nodule models for quantitative assessment of CNT fibrogenicity and document the impact of CNT characteristics on FSC acquisition and fibrogenesis. This Aim will also identify specific FSC biomarkers and validate the in vitro models in animals. Aim 3 will examine redox regulation of FSC development and fibrogenesis, and determine specific oxidative species and key regulatory enzymes involved in the process. Our expectations are that at the conclusion of this project, we will have determined the role of FSCs in CNT fibrogenesis and identified specific biomarkers and key physicochemical properties of CNTs that influence their fibroticity. This work is important because of the overall impact it will have on the development of safe nanomaterials as well as on risk assessment, early detection and prevention of nanomaterial-induced fibrosis. We expect this impact to be broad since the findings from this project are highly applicable to other fibrogenic agents, nanomaterials and xenobiotics. The proposed work is innovative because it is the first to study FSCs and their role in fibrosis. It will also develop novel experimental models and assay methods for rapid assessment of nanomaterial fibrogenicity and for their potential utility in various stem cell applications.