Volatile anesthetic modulation of glutamate transporters

谷氨酸转运蛋白的挥发性麻醉调节

• 批准号: 7173747
• 负责人: ZHIYI ZUO
• 金额: $ 24.56万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7173747
• 关键词: 1-Phosphatidylinositol 3-Kinase; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Anesthesia procedures; Anesthetics; Antisense Oligonucleotides; Brain Hypoxia-Ischemia; Brain region; Carrier Proteins; Cells; Cerebellum; Cerebral cortex; Clinical; Condition; Confocal Microscopy; Cultured Cells; Data; Dependence; Detection; Disease; Down-Regulation; Energy Supply; Enzymes; Extracellular Space; Functional disorder; Glutamate Transporter; Glutamates; Goals; Hippocampus (Brain); Human; Huntington Disease; Hypoxia; Ischemia; Ischemic Brain Injury; Isoenzymes; Measures; Mediating; Molecular; Neuraxis; Neurodegenerative Disorders; Neuroglia; Neuronal Injury; Neurons; Neurotransmitters; Noise; Phosphorylation; Phosphorylation Site; Physiological; Play; Property; Protein Kinase; Protein Kinase C; Rattus; Regulation; Research; Research Personnel; Role; Secure; Signal Transduction; Site; Stroke; Subcellular Fractions; Synaptic Transmission; Testing; Traumatic Brain Injury; Western Blotting; base; cell type; citrate carrier; extracellular; immunocytochemistry; inhibitor/antagonist; injury prevention; mutant; neuroprotection; neurotoxicity; neurotransmission; prevent; programs; receptor; research study; trafficking

DESCRIPTION (provided by applicant) Glutamate transporters (EAATs) play an important role in the regulation of extracellular levels of glutamate, a major excitatory neurotransmitter in the central nervous system. Current data suggest that increased extracellular glutamate concentration is involved in the pathophysiology of ischemic brain injury and several major human neurodegenerative disorders, such as Alzheimer's and Huntington's diseases, as well as amyotrophic lateral sclerosis. Thus, normal functioning of EAATs is important for maintaining efficient neurotransmission and preventing neuronal injury. Our long-term research goals are to understand the regulation of EAATs and their role in the mechanisms of anesthesia and neuroprotection. Volatile anesthetics increase the activity of EAATs. Ischemia causes reversed transport of glutamate via EAATs. This proposal aims to 1) determine the effects and mechanisms of volatile anesthetics on the trafficking and activity of EAATs, especially the role of protein kinase C (PKC) in mediating these anesthetic effects; 2) study the anesthetic effects on reversed transport of glutamate via EAATs. Cultured cells will be exposed to volatile anesthetics and cellular distribution of EAATs will be studied by immunocytochemistry with confocal microscopy and Western blotting of the subcellular fractions. The importance of potential PKC-dependent phosphorylation sites in mediating the anesthetic effects on the type 3 glutamate transporter will be determined by site-directed mutagensis. The PKC-isozyme dependence of the anesthetic regulation of this transporter also will be investigated by using isozyme specific inhibitors, down-regulation of isozymes and re-introduction of implicated isozymes. Ischemia-/hypoxia-induced reversed transport of glutamate in different rat brain regions (hippocampus, cerebral cortex and cerebellum) and cultured cell types (glia and neurons) will be evaluated in the presence or absence of volatile anesthetics. These studies will provide a molecular basis for the anesthetic and PKC regulation of glutamate transport and may suggest new targets for anesthesia or neuroprotection.

说明（申请人提供）谷氨酸转运蛋白（EAAT）在调节谷氨酸的细胞外水平中起重要作用，谷氨酸是中枢神经系统中的主要兴奋性神经递质。目前的数据表明，细胞外谷氨酸浓度增加涉及缺血性脑损伤和几种主要的人类神经退行性疾病，如阿尔茨海默氏病和亨廷顿病，以及肌萎缩侧索硬化症的病理生理学。因此，EAAT的正常功能对于维持有效的神经传递和防止神经元损伤是重要的。我们的长期研究目标是了解EAAT的调节及其在麻醉和神经保护机制中的作用。挥发性麻醉剂增加EAAT的活性。缺血引起谷氨酸通过EAAT的反向转运。本研究拟探讨挥发性麻醉药对EAATs转运和活性的影响及其机制，特别是蛋白激酶C（PKC）在介导这些麻醉效应中的作用; 2）研究麻醉药对谷氨酸通过EAATs逆向转运的影响。将培养的细胞暴露于挥发性麻醉剂，并通过免疫细胞化学、共聚焦显微镜和亚细胞组分的Western印迹法研究EAAT的细胞分布。将通过定点突变确定潜在PKC依赖性磷酸化位点在介导对3型谷氨酸转运蛋白的麻醉作用中的重要性。还将通过使用同工酶特异性抑制剂、下调同工酶和重新引入相关同工酶来研究该转运蛋白的麻醉调节的PKC同工酶依赖性。将在存在或不存在挥发性麻醉剂的情况下评价不同大鼠脑区域（海马、大脑皮层和小脑）和培养细胞类型（神经胶质和神经元）中缺血/缺氧诱导的谷氨酸盐反向转运。这些研究将为麻醉和PKC调节谷氨酸转运提供分子基础，并可能为麻醉或神经保护提供新的靶点。