Neuroprotection after Isoflurane Preconditioning

异氟烷预处理后的神经保护

• 批准号: 6826226
• 负责人: ZHIYI ZUO
• 金额: $ 28.21万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6826226
• 关键词: RNA interference; biological signal transduction; cerebral ischemia /hypoxia; cyclic GMP; cytoprotection; enzyme activity; gene expression; genetic regulation; glutamate transporter; glutamates; ischemic preconditioning; isoflurane; laboratory rat; mitogen activated protein kinase; neuroprotectants; nitric oxide; phosphorylation; sectioning; stroke; transcription factor; western blottings

DESCRIPTION (provided by applicant): Stroke is a major killer in the USA. The underlying pathophysiology for stroke is ischemia and reperfusion brain injury. Although many neuroprotective interventions have been identified, clinically practical methods to reduce ischemic brain injury are not well established yet. Our long-term research goals are to identify effective interventions for ischemic brain injury and to understand the mechanisms of these interventions. Our preliminary results suggest a novel neuroprotective method in which a prior brief exposure to isoflurane (preconditioning) is used to induce ischemic tolerance. Initial studies suggest that the mechanisms for this isoflurane preconditioning (IsoP)-induced neuroprotection involve alteration of glutamate transporter function in the acute phase and activation of p38 mitogen-activated protein kinase (MAPK) in the delayed phase. The proposed studies will: 1) investigate which glutamate transporters are involved and how the functional changes of the involved glutamate transporters translate into improved neurological outcome; 2) examine how p38 is activated by isoflurane; 3) determine whether the high mobility group (HMG) I (Y) transcription factor is downstream of p38 for IsoP-induced neuroprotection. Brain slices and in vivo temporary middle cerebral arterial occlusion models will be used. Neuronal survival will be evaluated by histological analysis. Extracellular glutamate levels in the ischemic penumbra will be quantified by microdialysis. Antisense oligonucleotides will be used to downregulate selective proteins such as glutamate transporters, p38 MAPK kinases and HMG I(Y). Western analysis and immunohistochemistry will be used to quantify and localize protein expression. Brain regional expression of HMG I(Y) will be determined by quantitative in vitro autoradiography. These studies will provide insight into the mechanisms of neuroprotection by IsoP and may elucidate mechanisms that could be exploited by new drugs. Since isoflurane has been used safely in clinical practice for many years, IsoP may prove to be a useful clinical method to reduce ischemic brain injury.

描述（由申请人提供）：中风是美国的主要杀手。中风的潜在病理生理学是缺血和再灌注脑损伤。虽然已经确定了许多神经保护性干预措施，但临床上减少缺血性脑损伤的实用方法还没有很好地建立。我们的长期研究目标是确定缺血性脑损伤的有效干预措施，并了解这些干预措施的机制。我们的初步研究结果表明，一种新的神经保护方法，其中预先短暂暴露于异氟烷（预处理）是用来诱导缺血耐受。初步研究表明，这种异氟醚预处理（IsoP）诱导的神经保护作用的机制涉及改变谷氨酸转运体功能的急性期和激活p38丝裂原活化蛋白激酶（MAPK）在延迟相。拟议的研究将：1）研究涉及哪些谷氨酸转运蛋白以及所涉及的谷氨酸转运蛋白的功能变化如何转化为改善的神经学结果; 2）研究p38如何被异氟烷激活; 3）确定高迁移率族（HMG）I（Y）转录因子是否位于p38下游，以实现IsoP诱导的神经保护。将使用脑切片和体内暂时性大脑中动脉闭塞模型。将通过组织学分析评价神经元存活。将通过微透析定量缺血半暗带中的细胞外谷氨酸水平。反义寡核苷酸将用于下调选择性蛋白质，如谷氨酸转运蛋白、p38 MAPK激酶和HMG I（Y）。Western分析和免疫组织化学将用于定量和定位蛋白质表达。HMG I（Y）的脑区域表达将通过定量体外放射自显影术来确定。这些研究将为IsoP的神经保护机制提供深入了解，并可能阐明可被新药利用的机制。由于异氟醚已安全地应用于临床多年，IsoP可能被证明是一种有效的临床方法，以减少缺血性脑损伤。