Regulatory Control of Glutamate - Induced Superoxide Production

描述（由申请人提供）：谷氨酸诱导的神经元超氧化物产生的监管控制项目摘要/摘要谷氨酸兴奋性毒性是中风、脑创伤中细胞死亡的主要原因。神经元产生的超氧化物是必要的兴奋性细胞死亡的发生。谷氨酸诱导的超氧化物产生长期以来一直被认为是钙内流和导致线粒体功能障碍的不可避免的物理后果，但最近的研究表明，超氧化物是由信号酶NADPH氧化酶产生的。在这里，我们的目标是描绘关键的调节步骤，在信号转导通路连接神经元谷氨酸受体激活NADPH氧化酶激活，和这个过程中的作用，在局部细胞到细胞的兴奋性毒性损伤的传播。初步研究表明，该途径的关键组分包括NMDA型谷氨酸受体的NR 2B亚基、磷酸肌醇-3-激酶（PI 3 K）、PTEN和磷脂酶A2。本文提出的研究将使用药理学、显性阴性和遗传学方法评估这些组分中每一种的重要性。我们还旨在确定NADPH氧化酶和线粒体可能在超氧化物产生中相互作用的机制。这些研究将使用分离的神经元培养物、脑切片和整体动物实验模型进行。这些研究的成功完成将调和这一领域长期存在的矛盾，并将确定新的目标和机制，促进急性和慢性神经系统疾病。这些研究也将进一步加深我们对神经元之间正常超氧化物信号传导的分子框架的理解，这一过程被认为是调节大脑中突触可塑性的过程。1 公共卫生相关性：谷氨酸诱导的神经元死亡是急性发作的疾病如中风和创伤以及更慢性的疾病如肌萎缩性侧索硬化和阿尔茨海默病中神经损伤的重要原因。活性氧，超氧化物，已知介导谷氨酸诱导的神经元死亡。本文提出的研究将确定从谷氨酸受体激活到超氧化物产生的关键步骤，从而确定阻断或调节这一重要细胞损伤途径的方法。

DESCRIPTION (provided by applicant): Regulatory control of glutamate - induced neuronal superoxide production Project Summary/Abstract Glutamate excitotoxicity is a primary cause of cell death in stroke, brain trauma. Neuronal production of superoxide is necessary for excitotoxic cell death to occur. Glutamate-induced superoxide production has long been considered an inevitable, physical consequence of calcium influx and resulting mitochondrial dysfunction, but recent studies show that the superoxide is instead produced by the signaling enzyme, NADPH oxidase. Here we aim to delineate key regulatory steps in the signal transduction pathway linking neuronal glutamate receptor activation to NADPH oxidase activation, and the role of this process in local cell-to-cell propagation of excitotoxic injury. Preliminary studies suggest that key components of this pathway include the NR2B subunit of NMDA-type glutamate receptors, phosphoinositol-3-kinase (PI3K), PTEN, and phospholipase A2. The studies proposed here will evaluate the importance of each of these components using pharmacological, dominant negative, and genetic approaches. We also aim to identify mechanisms by which NADPH oxidase and mitochondria may interact in superoxide production. These studies will be performed using dissociated neuronal cultures, brain slices, and whole-animal experimental models. Successful completion of these studies will reconcile long-standing contradictions in this field, and will identify novel targets and mechanisms contributing to both acute and chronic neurological disorders. These studies will also further our understanding of the molecular framework for normal superoxide signaling between neurons, a process thought to modulate synaptic plasticity in brain. 1 PUBLIC HEALTH RELEVANCE: Glutamate - induced neuronal death is an important cause of neural injury in both acute-onset disorders such as stroke and trauma, and more chronic disorders such as amyotrophic lateral sclerosis and Alzheimer's disease. The reactive oxygen species, superoxide, is known to mediate glutamate-induced neuronal death. Studies proposed here will identify key steps leading from glutamate receptor activation to the production of superoxide, and thereby identify ways of blocking or modulating this important cell injury pathway.