Role of NADPH oxidase 1-derived ROS in the pathogenesis of Parkinson's disease

摘要 线粒体功能障碍、氧化应激、蛋白酶体功能受损和蛋白质聚集 是黑质多巴胺能神经元丢失的共同分子基础 康培达(SNPC)。线粒体功能障碍与多巴胺能神经元易损性增加 氧化应激与帕金森病的发病机制密切相关。活性物质的分子来源 然而，PD中的氧物种(ROS)还没有被清楚地阐明。ROS是生理副产品 几种细胞器和生物反应，包括线粒体，过氧化物体，细胞色素P-450， 黄嘌呤氧化酶、环氧合酶和一氧化氮合酶。 NADPH氧化酶家族(NOX)是第一个被发现的专门针对 产生超氧化物。在中枢神经系统中已经明确了氮氧化物的同系物。 (中枢神经系统)，并被证明在发育、记忆、神经信号和心血管方面发挥重要作用 动态平衡。与此同时，同样重要的证据表明，生产过剩 NOx异常激活引起的ROS也可能参与神经退行性变。此外，最近的研究 提示线粒体在NADPH氧化酶(尤其是NOX1)介导的超氧化物歧化中起作用 一代。线粒体和NOX1之间的相互作用放大ROS的产生并导致细胞 死亡。这表明两个主要因素，线粒体功能障碍和氧化应激，牵涉其中 在帕金森病发病机制中可能通过NOX系统相互联系。 我们的初步结果表明，DA细胞中配备了NOX介导的超氧化物 代建制。NOX1是由6-OHDA和线粒体毒素等氧化应激诱导的， 鱼藤酮。抑制NOx激活或Nox1基因敲除的关键成分rac1导致保护 6-羟基多巴胺处理的黑质DA神经元。LRRK2突变(G2019S)增加ROS N27 DA细胞的产生和NADPH氧化酶特异性抑制剂apocynin减少ROS的产生 由LRRK2突变体诱导。这些拟议的研究将调查1)抑制NOX1是否会导致 DA神经保护，2)DA细胞特异性转录调控的分子机制 NOX1和线粒体参与以及3)LRRK2突变是否影响NOX-1的激活 介导ROS的产生和相应的DA神经退行性变。

ABSTRACT Mitochondrial dysfunction, oxidative stress, impairment of proteasomal function and protein aggregation are the common molecular basis of the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpC). Mitochondrial dysfunction and increased vulnerability of dopaminergic (DA) neurons to oxidative stress has specifically implicated in the pathogenesis of PD. Molecular sources for reactive oxygen species (ROS) in PD however have not been clearly elucidated. ROS are physiologic byproduct of several organelles and biological reactions including mitochondria, peroxisomes, cytochrome P-450, xanthine oxidase, cyclooxygenase and NO synthase. A family of NADPH oxidase (NOX) is the first enzyme complex discovered which is specialized to generate superoxide. Nox homologues have been specifically identified in the central nervous system (CNS) and shown to play major roles in development, memory, neuronal signaling, and cardiovascular homeostasis. At the same time, an equally significant body of evidence has shown that overproduction of ROS by abnormal Nox activation may also contribute to neurodegeneration. Moreover, recent studies indicate that mitochondria play a role in NADPH oxidase-mediated (especially NOX1) superoxide generation. The interplay between mitochondria and NOX1 amplifies ROS generation and results in cell death. This suggests that two cardinal factors, mitochondrial dysfunction and oxidative stress, implicated in the PD pathogenesis may link each other through the NOX system. Our preliminary results demonstrate that DA cells are equipped with the NOX-mediated superoxide generation system. NOX1 was induced by oxidative stress such as 6-OHDA and mitochondrial toxin, rotenone. Inhibition of Rac1, a key component for Nox activation or Nox1 knockdown led to protection of substantia nigra DA neurons from 6-OHDA administration. LRRK2 mutation (G2019S) increased ROS generation in N27 DA cells and apocynin, a specific NADPH oxidase inhibitor reduced ROS production elicited by LRRK2 mutant. These proposed studies will investigate 1) whether inhibition of NOX1 leads to DA neuroprotection, 2) the molecular mechanism underlying DA cell-specific transcriptional regulation of NOX1 and mitochondrial involvement and 3) whether LRRK2 mutations affect the activation of NOX- mediated ROS production and consequential DA neurodegeneration.