Focal Brain Ischemia in the TNF-alpha-Transgenic Rat

TNF-α 转基因大鼠的局灶性脑缺血

• 批准号: 6846319
• 负责人: L. CREED Pettigrew
• 金额: $ 27.25万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6846319
• 关键词: apoptosis; behavior test; biological signal transduction; brain circulation; cerebral ischemia /hypoxia; cognition; cytokine receptors; disease /disorder model; gel mobility shift assay; genetically modified animals; immune response; immunocytochemistry; laboratory rat; model design /development; neural degeneration; neurochemistry; polymerase chain reaction; tumor necrosis factor alpha

DESCRIPTION (provided by applicant): Tumor necrosis factor-alpha (TNFalpha) is a pleotrophic cytokine secreted by astroglia, macrophages, and other cells participating in the inflammatory reaction initiated by cerebral infarction. Levels of TNFalpha rise sequentially in the infarct core, the ischemic penumbra, and in unaffected tissue in human brain damaged by stroke and may persist up to 40 days afterward. The Overall Goal of this R01 proposal is to establish the TNFalpha-transgenic rat as a new model for investigation of TNF receptor (TNFR)-mediated signal transduction and cell death pathways activated during brain infarction in man. This animal was constructed to overexpress the murine TNFalpha gene with its own promoter and has never been used to investigate the pathophysiology of any brain disorder. Cerebral tissue obtained from the transgenic rat shows elevated levels of TNFalpha mRNA and protein. When subjected to middle cerebral artery occlusion, transgenic animals have larger mean percent infarct volume than wild type controls. We will employ this unique animal to test our principal Hypothesis: Upregulated synthesis of TNFalpha in ischemic brain augments neuronal apoptosis by receptor-mediated activation of signal transduction cascades. We propose to accomplish the following Specific Aims: 1) to characterize the neurochemical and cerebrovascular anatomy, physiology, and cognitive function of the TNFalpha-transgenic rat under normal conditions and in response to ischemic brain injury, 2) to identify the cellular origin of TNFalpha and define the immune response to cerebral ischemic injury in the TNFalpha-transgenic rat, 3) to use the transgenic animal to simulate how elevated TNFalpha levels affect TNFR number or distribution and modulate signal transduction cascades in ischemic human brain, 4) to use the transgenic animal to simulate how elevated TNFalpha levels influence apoptotic neuronal degeneration in ischemic human brain, and 5) to assess the research utility of the TNFalpha-transgenic rat as a model for therapeutic intervention by determining if pre- or post-ischemic inhibition of TNFalpha synthesis attenuates ischemic injury.

描述（申请人提供）：肿瘤坏死因子-α（TNFα）是一种多效细胞因子，由星形胶质细胞、巨噬细胞和其他参与脑梗塞引发的炎症反应的细胞分泌。梗塞核心、缺血半暗带和因中风受损的人脑中未受影响的组织中的 TNFα 水平依次升高，并可能持续长达 40 天。 R01提案的总体目标是建立TNFα转基因大鼠作为研究TNF受体（TNFR）介导的信号转导和人类脑梗塞期间激活的细胞死亡途径的新模型。这种动物被构建为过度表达鼠类 TNFα 基因及其自身的启动子，并且从未用于研究任何脑部疾病的病理生理学。从转基因大鼠获得的脑组织显示 TNFα mRNA 和蛋白质水平升高。当大脑中动脉闭塞时，转基因动物比野生型对照具有更大的平均梗塞体积百分比。我们将利用这种独特的动物来测试我们的主要假设：缺血性脑中 TNFα 合成的上调通过受体介导的信号转导级联激活来增强神经元凋亡。我们建议实现以下具体目标：1）表征 TNFα 转基因大鼠在正常条件下和对缺血性脑损伤的反应中的神经化学和脑血管解剖学、生理学和认知功能，2）确定 TNFα 的细胞起源并定义 TNFα 转基因大鼠对脑缺血损伤的免疫反应，3) 使用转基因动物模拟 TNFα 水平升高如何影响 TNFR 数量或分布，以及调节缺血人脑中的信号转导级联，4) 使用转基因动物模拟 TNFα 水平升高如何影响缺血人脑中的细胞凋亡神经元变性，以及 5) 评估 TNFα 转基因大鼠作为治疗模型的研究效用通过确定缺血前或缺血后抑制 TNFα 合成是否减轻缺血性损伤来进行干预。