Neurotoxicity of nanomaterials: evaluation of subcellular redox state

描述(由申请人提供) 几种制造的纳米材料诱导氧化应激的能力被认为是评估制造的纳米材料潜在毒性的最合适的手段。由于氧化应激是包括各种神经退行性疾病在内的许多疾病的共同致病机制，因此各种纳米材料可能参与了疾病的进程。我们已经证明，神经元(在体外和体内)的氧化还原状态(还原和氧化成分之间的动态平衡)可以通过亚细胞隔间在空间上分解。神经毒物可以优先氧化细胞质、线粒体或核氧化还原成分，如硫氧还蛋白或谷胱甘肽。我们假设，纳米材料的总体毒性将与它们在不同亚细胞隔间诱导氧化应激的能力相对应，这些措施将为评估其潜在毒性提供更好的手段。我们提出了一系列体外和体内实验，旨在确定已知特别容易受到氧化损伤的细胞群体的亚细胞氧化还原状态，即黑质致密部中的多巴胺神经元。目的1.测定制备的纳米材料富勒烯(C60)、富勒醇(C60(OH)22-24)、氧化锰(MnO2)、二氧化钛(TiO2)、磁性氧化铁(FeO4)和纳米零价铁(n-ZVI)优先氧化细胞内氧化还原成分的能力。在这一目标中，我们将检测悬浮纳米颗粒在没有和存在氧化挑战(6-OHDA)的情况下，在神经源性细胞培养中诱导氧化应激的能力。此外，我们将评估纳米材料在接触细胞模型之前和之后的物理化学性质。目的：检测纳米材料二氧化锰(MnO2)、二氧化钛(TiO2)、磁性氧化铁(FeO4)和纳米零价铁(n-Zvi)诱导多巴胺能脑区氧化应激的能力。这一目标将检测纳米材料改变亚细胞氧化还原状态和诱导多巴胺能脑区氧化损伤的能力，并确定纳米材料在给药前和暴露动物的脑组织中的物理化学状态。目的3.测定生物可用抗氧化剂减轻人工纳米材料所致氧化应激的能力。为此，将在体外和体内环境中测试N-乙酰半胱氨酸和α-生育酚减轻氧化应激的能力。这些目标的实现将提供有关纳米材料以亚细胞空间分辨率诱导氧化应激能力的新信息，并确定它们在暴露于生物系统后是否发生了物理化学状态的改变。

DESCRIPTION (provided by applicant) The ability to several manufactured nanomaterials to induce oxidative stress has been suggested to be the most appropriate means of assessing the potential toxicity of manufactured nanomaterials. Since oxidative stress is a common pathogenic mechanism in numerous diseases, including various neurodegenerative diseases, it is possible that the various nanomaterials may contribute to the disease process. We have shown that the redox state (dynamic balance between reduced and oxidized components) of neurons (in vitro and in vivo) can be spatially resolved by subcellular compartment. Neurotoxicants can preferentially oxidize cytoplasmic, mitochondrial, or nuclear redox components, such as thioredoxin or GSH. We hypothesize that the overall toxicity of nanomaterials will correspond to their ability to induce oxidative stress in distinct subcellular compartments and that these measures will provide a superior means of assessing their potential toxicity. We propose a series of in vitro and in vivo experiments aimed at determining the subcellular redox state of a cellular population known to be especially vulnerable to oxidative injury, namely, the dopamine neurons in the substantia nigra pars compacta. Aim 1. To determine the ability of the manufactured nanomaterials fullerene (C60), fullerol (C60(OH)22-24), manganese oxide (MnO2), titanium dioxide (TiO2), magnetic iron oxide (FeO4), and nanoscale zero valent iron (n-ZVI) to preferentially oxidize sucellular redox components. In this aim, we will examine the ability of suspended nanoparticles to induce oxidative stress in cell cultures of neuronal origin in the absence and presence of an oxidative challenge (6-OHDA). In addition, we will assess the physico-chemical properties of the nanomaterials prior to and after exposure to the cellular model. Aim 2. To determine the ability of the manufactured nanomaterials "manganese oxide (MnO2), titanium dioxide (TiO2), magnetic iron oxide (FeO4), and nanoscale zero valent iron (n-ZVI) to induce oxidative stress in dopaminergic brain regions. This aim will examine the ability of nanomaterials to alter subcellular redox state and induce oxidative damage in dopaminergic brain regions and determine the physico-chemical state of the nanomaterials prior to administration and in the brain tissue of exposed animals. Aim 3. To determine the ability of bioavailable antioxidants to attenuate the oxidative stress induced by manufactured nanomaterials. In this aim N-acetyl cysteine and alpha tocopherol will be tested for their ability to attenuate oxidative stress in in vitro and in vivo settings. Completion of these aims will provide novel information on the ability of nanomaterials to induce oxidative stress with subcellular spatial resolution and determine if their physico-chemical state is altered after exposure to the biological system.