NADPH Oxidase 2 in Parkinson's Disease Pathogenesis

摘要 黑质纹状体神经元的氧化还原失衡被认为是 家族性和特发性帕金森病患者的黑质纹状体变性。虽然人们通常认为 帕金森病患者的氧化损伤来自于线粒体电子传递链功能障碍，有 越来越多的共识认为，NADPH氧化酶亚型2(NOX2)可能是重要的，在一些细胞系统中， 这两个似乎在氧化还原调节途径中密切相关，最近被称为“ROS诱导的ROS产生”。 (RIRP)。然而，NOX2在帕金森病发病机制中的相关性尚不清楚。此外，现场 NOX2活性状态的检测一直很难评估。使用一种新的组织学邻近结扎术(PL) 检测NOX2激活状态的方法具有出色的细胞分辨率，我们的初步发现解决了 特发性帕金森病和帕金森病动物模型中NOX2活性的相关性。 我们的初步研究表明，NOX2可以被线粒体来源的ROS以RIRP方式激活， 这有助于极大地放大ROS的生产。由此产生的NOX2活性是必要的，也是充分的 激活野生型LRRK2并导致α-突触核蛋白的积聚和氧化翻译后修饰 (4-hne-α-syn和no-α-syn)。NOX2激活的LRRK2激酶活性导致内切溶酶体和 自噬缺陷和α-突触核蛋白的有毒物种的降解减少，如pSer129-α-突触核蛋白。在……里面 通过这种方式，NOX2的活性既推动了有毒形式的α-突触核蛋白的形成，又抑制了其处置。反过来, 如以前的工作所示，这些形式的α-突触核蛋白与线粒体TOM20结合，阻止蛋白质的输入和释放。 导致线粒体功能改变和相对增加的ROS产生。因此，似乎有 一个前馈循环，其中NOX2在帕金森病的发病机制中起着重要的放大作用。 然而，其他NOx，包括亚型1和亚型4--也在大脑中高度表达--可能起到了某种作用 这一致病过程。在这方面，目前的提案旨在进一步探讨和界定 NOX2在帕金森病中的排他性作用。 阳性结果表明NOX2在帕金森病发病机制中的相关性和NOX2导向的疗效 使用反义寡核苷酸(ASO)的治疗将揭示潜在的治疗策略 神经保护和改善帕金森病相关的运动障碍。因此，这个项目具有令人信服的实用性 对帕金森病治疗的意义。

ABSTRACT Reductive-oxidative (redox) imbalance in nigrostriatal neurons has been indicated as an important cause of nigrostriatal degeneration in familial and idiopathic Parkinson disease (PD). While it is generally assumed that the oxidative damage seen in PD derives from dysfunctional mitochondrial electron transport chain, there is growing consensus that NADPH oxidase isoform 2 (NOX2) may be important and, in some cellular systems, the two appear intimately related in a redox regulatory pathway recently termed “ROS-induced ROS production” (RIRP). However, the relevance of NOX2 in PD pathogenesis remains underexplored. Additionally, the in-situ detection of NOX2 activity state has been difficult to assess. Using a novel histological proximity ligation (PL) assay to detect NOX2 activation state with excellent cellular resolution, our preliminary findings address the relevance of NOX2 activity, in idiopathic PD and in PD animal models of parkinsonism. Our preliminary studies reveal that NOX2 can be activated by mitochondrially-derived ROS in a RIRP manner, which serves to greatly amplify ROS production. The resultant NOX2 activity is necessary and sufficient to both activate wildtype LRRK2 and to cause accumulation and oxidative post-translational modifications of α-synuclein (4-HNE-α-syn and NO-α-syn). The NOX2-activated LRRK2 kinase activity leads to endo-lysosomal and autophagic defects and decreased degradation of toxic species of α-synuclein, such as pSer129-α-synuclein. In this way, NOX2 activity both drives the formation and inhibits the disposal of toxic forms of α-synuclein. In turn, as shown in previous work, these forms of α-synuclein bind to mitochondrial TOM20, blocking protein import and leading to mitochondrial functional alterations and relative increased ROS production. Thus, there appears to be a feedforward cycle, in which NOX2 plays an essential amplification role in PD pathogenesis. However, other NOXs, including isoforms 1 and 4 – also highly expressed in brain - might contribute somehow to this pathogenic process. In this context, the current proposal is designed to further explore and define the exclusive role of NOX2 in PD. Positive outcomes demonstrating the relevance of NOX2 in PD pathogenesis and the efficacy of NOX2-directed therapies using antisense oligonucleotides (ASOs), will reveal potential therapeutic strategies for neuroprotection and ameliorate the PD-related movement disorder. As such, this project has compelling practical significance for PD therapeutics.