Neurotoxicity of nanomaterials: evaluation of subcellular redox state

描述（由申请人提供） 若干人造纳米材料诱导氧化应激的能力被认为是评估人造纳米材料潜在毒性的最适当方法。由于氧化应激是许多疾病（包括各种神经退行性疾病）的常见致病机制，因此各种纳米材料可能有助于疾病过程。我们已经表明，氧化还原状态（还原和氧化成分之间的动态平衡）的神经元（在体外和体内），可以空间分辨的亚细胞区室。神经毒物可优先氧化细胞质、线粒体或核氧化还原组分，如硫氧还蛋白或GSH。我们假设纳米材料的总体毒性将与其在不同亚细胞区室中诱导氧化应激的能力相对应，并且这些措施将提供评估其潜在毒性的上级方法。我们提出了一系列的体外和体内实验，旨在确定亚细胞的氧化还原状态的细胞群已知是特别容易受到氧化损伤，即多巴胺神经元在黑质pars延髓。目标1.确定人造纳米材料富勒烯（C60）、富勒醇（C60（OH）22-24）、氧化锰（MnO 2）、二氧化钛（TiO 2）、磁性氧化铁（FeO 4）和纳米级零价铁（n-ZVI）优先氧化亚细胞氧化还原组分的能力。在这个目标中，我们将研究悬浮的纳米颗粒在不存在和存在氧化挑战（6-OHDA）的情况下诱导神经元来源的细胞培养物中的氧化应激的能力。此外，我们将评估纳米材料暴露于细胞模型之前和之后的物理化学性质。目标2.确定人造纳米材料氧化锰（MnO 2）、二氧化钛（TiO 2）、磁性氧化铁（FeO 4）和纳米级零价铁（n-ZVI）诱导多巴胺能脑区氧化应激的能力。该目的将检查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，并确定给药前和暴露动物脑组织中纳米材料的理化状态。目标3.确定生物可利用的抗氧化剂减弱人造纳米材料诱导的氧化应激的能力。为此，将测试N-乙酰半胱氨酸和α-生育酚在体外和体内环境中减弱氧化应激的能力。这些目标的完成将提供新的信息，纳米材料的能力，以诱导氧化应激与亚细胞空间分辨率，并确定其物理化学状态是否改变后，暴露于生物系统。

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.