The role of NOX4 and its interaction with mitochondria and Nrf2 in hyperexcitability-induced neurodegeneration

NOX4 的作用及其与线粒体和 Nrf2 的相互作用在过度兴奋诱导的神经变性中的作用

• 批准号: 408780607
• 负责人: Dr. Stjepana Kovac, Ph.D.
• 金额: --
• 依托单位: Klinik für Neurologie mit Institut für Translationale Neurologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408780607?language=en
• 关键词: role; NOX4; its; interaction; mitochondria

Hyperexcitability is a common mechanism leading to neurodegeneration in a plethora of central nervous system (CNS) diseases. It occurs amongst others in epilepsy and multiple sclerosis (MS) where reactive oxygen species (ROS) have been shown to play a role. Despite overwhelming evidence of their critical role in neurodegeneration, targeting ROS has been challenging, and clinical trials aimed at scavenging ROS, once they have been produced, have largely failed. One explanation for this is that scavenging of ROS with direct antioxidants is futile since large doses and a sustained supply of antioxidants are needed, which by themselves might have other adverse effects. Thus, targeting sources of ROS, rather than ROS once they have already been produced, represents an appealing strategy. This in turn requires a careful characterization of the sources of ROS production, as some may be beneficial to the cell.We have previously shown that nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) oxidases, which are enzymes highly specialized in ROS production, play a pivotal role in hyperexcitability-induced neurodegeneration. Seven different isoforms of NADPH oxidases exist (NOX1-5, and DUOX1 and 2). In preliminary experiments, we recently found high expression of NOX4 in brain resident cells, and that NOX4 interacts both with mitochondria and nuclear factor erythroid 2–related factor 2 (Nrf2). On the one hand, these interactions are important since energy depletion and thus mitochondria, as the “powerhouses of the cell”, play a lead role in hyperexcitability-induced neurodegeneration. On the other hand, the transcription factor Nrf2, which upon activation drives transcription of antioxidant proteins, has also been shown to contribute to neurodegeneration during hyperexcitability. This implies that targeting NOX4 is likely a promising strategy to combat hyperexcitability-induced neurodegeneration.We here propose to first study the impact of NOX4 on hyperexcitability-induced neurodegeneration and the interaction between NOX4 and mitochondria and NOX4 and Nrf2 during hyperexcitability. This will be done with live cell imaging techniques in different brain resident cells (astrocytes, neurons, endothelial cells and microglia) in addition to molecular biology analyses in NOX4-deficient mice. Next, we will use a mouse model of hyperexcitability-induced neurodegeneration to study the role of NOX4, taking advantage of global and tissue-specific NOX4-deficient animals, i.e. mice with a NOX4 deficiency in endothelial or neuronal tissue (NOX4endo -/- and NOX4neuro -/-) and live-cell imaging analyses in brain slices in addition to electrophysiology and immunohistochemistry. Finally, we will corroborate data obtained from animal experiments by analysing post mortem human brain tissues of patients suffering from MS, a disease characterized by hyperexcitability-induced neurodegeneration, using immunohistochemistry.

过度兴奋是导致大量中枢神经系统（CNS）疾病中神经退行性变的常见机制。它发生在癫痫和多发性硬化症（MS）中，其中活性氧（ROS）已被证明发挥作用。尽管有压倒性的证据表明它们在神经退行性变中起着关键作用，但靶向ROS一直具有挑战性，并且旨在清除ROS的临床试验一旦产生，就基本上失败了。对此的一种解释是，用直接抗氧化剂清除ROS是徒劳的，因为需要大剂量和持续供应抗氧化剂，其本身可能具有其他不良影响。因此，靶向ROS的来源，而不是一旦它们已经产生的ROS，代表了一种有吸引力的策略。这反过来又需要一个仔细的ROS生产的来源的特性，因为有些可能是有益的cell.We以前已经表明，烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NADPH）氧化酶，这是高度专业化的ROS生产的酶，在过度兴奋性诱导的神经变性中发挥了关键作用。NADPH氧化酶有七种不同的亚型（NOX 1 -5和DUOX 1和2）。在初步的实验中，我们最近发现了高表达的NOX 4在脑驻留细胞，NOX 4与线粒体和核因子红细胞2相关因子2（Nrf 2）相互作用。一方面，这些相互作用是重要的，因为能量耗尽，因此线粒体，作为“细胞的动力”，在过度兴奋诱导的神经变性中发挥主导作用。另一方面，转录因子Nrf 2在激活后驱动抗氧化蛋白的转录，也已被证明有助于过度兴奋期间的神经变性。这意味着，针对NOX 4可能是一个有前途的战略，以打击过度兴奋诱导的neurodegeneration.We在这里建议首先研究NOX 4对过度兴奋诱导的神经退行性变的影响和NOX 4和线粒体之间的相互作用和NOX 4和Nrf 2在过度兴奋。除了在NOX 4缺陷小鼠中进行分子生物学分析外，还将在不同的脑驻留细胞（星形胶质细胞、神经元、内皮细胞和小胶质细胞）中使用活细胞成像技术进行。接下来，我们将使用过度兴奋诱导的神经变性的小鼠模型来研究NOX 4的作用，利用全局和组织特异性NOX 4缺陷动物，即内皮或神经元组织中NOX 4缺陷的小鼠（NOX 4 endo-/-和NOX 4 neuro-/-）以及脑切片中的活细胞成像分析以及电生理学和免疫组织化学。最后，我们将证实从动物实验中获得的数据，通过分析尸检人脑组织的患者患有MS，一种疾病的特点是过度兴奋诱导的神经变性，使用免疫组织化学。