Neurochemical and metabolic regulation in the visual cortex

视觉皮层的神经化学和代谢调节

• 批准号: 7302274
• 负责人: MARGARET TT WONG-RILEY
• 金额: $ 34.09万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7302274
• 关键词: AMPA Receptors; Affect; Binding; Binding Sites; Blindness; Blood flow; Cell Death; Cell Respiration; Cells; Cessation of life; Condition; Coupled; Coupling; Data; Defect; Diabetic Retinopathy; Energy Metabolism; Energy Supply; Enzymes; Genes; Genetic; Glutamate Receptor; Glutamates; Goals; Heart; In Vitro; Kainic Acid Receptors; Kidney; Lead; Leber' s Hereditary Optic Neuropathy; Light; Mediating; Metabolic; Mitochondria; Modeling; Molecular; N-Methyl-D-Aspartate Receptors; Nervous system structure; Neurons; Nitric Oxide Synthase Type I; Normal Statistical Distribution; Organ; Pattern; Physiological; Play; Positioning Attribute; Primates; Production; Property; Prostaglandin-Endoperoxide Synthase; Protein Overexpression; Proteins; RNA Interference; Rattus; Regulation; Reporting; Research Personnel; Role; Skeletal Muscle; Stress; Synapses; Synaptic Transmission; System; Testing; Transcriptional Activation; Visual; Visual Cortex; Work; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; amino 3 hydroxy 5 methylisoxazole 4 propionate; cyclooxygenase 1; cytochrome c oxidase; in vivo; mitochondrial DNA mutation; neurochemistry; neurotransmission; nuclear respiratory factor; programs; promoter; response; transcription factor; visual process; visual processing

DESCRIPTION (provided by applicant): Neuronal activity and energy metabolism are tightly coupled. Under normal conditions, neuronal activity controls energy metabolism and not vice versa. Visual neurons are among the metabolically most active cells in the nervous system, and their energy is derived almost exclusively from oxidative metabolism. Defective energy metabolism adversely affects visual neurons, often leading to blindness. Thus far, energy metabolism and neuronal activity have been assumed to be regulated at the molecular level by two independent mechanisms. The present proposal aims to test the hypothesis that a candidate transcription factor, nuclear respiratory factor 1 (NRF-1), co-regulates both energy metabolism and synaptic neurochemicals (glutamate AMPA receptor subunit 2 [GluR2] and/or neuronal nitric oxide synthase [nNOS]) in specific types of visual cortical neurons. NRF-1 is known to activate genes involved in mitochondrial function, including subunit genes of cytochrome oxidase (CO). Binding sites for NRF-1 have been reported on the promoters of GluR2 and nNOS genes, but it is not known if NRF-1 is necessary for their expression. Recently, NRF-1 was found to be present in mammalian visual cortical neurons and its expression was regulated by neuronal activity. Both GluR2 and nNOS are associated with glutamatergic synaptic neurotransmission and are present in mammalian visual cortex. Specific aim 1 is to establish baseline data on the normal distribution and levels of NRF-1, GluR2, and nNOS mRNAs and proteins in visual cortical neurons in vivo and in vitro, using rat as a model. Specific aim 2 is to suppress the expression of NRF-1 by means of small interference RNA silencing to determine if expressions of GluR2, nNOS, and CO will be severely affected in visual cortical neurons. NRF-1 knockdown neurons will be subjected to depolarizing stimulation to determine if increased activity differentially stresses GluR2-rich and nNOS-rich neurons, and if one or both of them will undergo cell death. Specific aim 3 is to overexpress NRF-1 to ascertain if expressions of GluR2, nNOS, and CO reduced by impulse blockade can be rescued. These studies will shed light on how a transcription factor can simultaneously regulate both energy metabolism and synaptic neurochemicals in visual cortical neurons, and how genetic perturbation of this factor can lead to impaired energy production, defective expression of neurochemicals, and possible death of visual cortical neurons.

描述（由申请人提供）：神经元活动和能量代谢紧密耦合。在正常情况下，神经元活动控制能量代谢，而不是相反。视觉神经元是神经系统中代谢最活跃的细胞之一，它们的能量几乎完全来自氧化代谢。能量代谢缺陷会对视觉神经元产生不利影响，常常导致失明。迄今为止，能量代谢和神经元活动被认为在分子水平上通过两种独立的机制进行调节。本提案旨在检验以下假设：候选转录因子核呼吸因子 1 (NRF-1) 共同调节能量代谢和突触神经化学物质（谷氨酸 AMPA 受体亚基 2 [GluR2] 和/或神经元一氧化氮合酶 [ nNOS]）在特定类型的视觉皮层神经元中。 NRF-1 已知可激活参与线粒体功能的基因，包括细胞色素氧化酶 (CO) 的亚基基因。已报道 GluR2 和 nNOS 基因的启动子上有 NRF-1 的结合位点，但尚不清楚 NRF-1 是否是其表达所必需的。最近，发现NRF-1存在于哺乳动物视觉皮层神经元中，其表达受神经元活动调节。 GluR2 和 nNOS 均与谷氨酸能突触神经传递相关，并且存在于哺乳动物视觉皮层中。具体目标1是以大鼠为模型，在体内和体外建立视觉皮层神经元中NRF-1、GluR2和nNOS mRNA和蛋白质的正态分布和水平的基线数据。具体目标2是通过小干扰RNA沉默的方式抑制NRF-1的表达，以确定视觉皮层神经元中GluR2、nNOS和CO的表达是否会受到严重影响。 NRF-1 敲低的神经元将受到去极化刺激，以确定增加的活性是否对富含 GluR2 和富含 nNOS 的神经元产生不同的压力，以及它们中的一个或两个是否会经历细胞死亡。具体目标 3 是过表达 NRF-1，以确定是否可以挽救因脉冲阻断而减少的 GluR2、nNOS 和 CO 的表达。这些研究将揭示转录因子如何同时调节视觉皮层神经元中的能量代谢和突触神经化学物质，以及该因子的遗传扰动如何导致能量产生受损、神经化学物质表达缺陷以及视觉皮层神经元可能的死亡。