CYTOKINE-MEDIATED ENHANCEMENT OF NEURONAL INJURY

描述(摘自申请者摘要)：病理生理学 迟发性神经元死亡，发生在脑损伤后数小时甚至数天 人们对脑缺血知之甚少。最近在动物模型中的研究表明 细胞因子诱导型一氧化氮合酶(INOS)被强烈诱导 广泛神经元变性周围星形胶质细胞1-3天 在脑缺血损伤后。休伊特博士之前的工作证明了 NO来源于细胞因子诱导的星形胶质细胞iNOS，而不是毒性的 单独使用会显著增加N-甲基-D-天冬氨酸的含量 氧糖剥夺诱导体外培养的神经元损伤 体内iNOS的激活可能会产生危险的后果，即 兴奋性中毒性神经元损伤。进一步的研究表明，这种增强作用是 与细胞外谷氨酸水平的增加有关，并 依赖于活性氧物种和NO。因此，这一目标是 该项目旨在阐明特定的细胞和分子事件，通过这些事件 星形胶质细胞中的NO和活性氧物种参与了 细胞因子介导的兴奋性毒性神经元损伤的增强作用。实验 将在原代皮质细胞培养中进行体外实验。星形细胞 诱导型一氧化氮合酶是由外源性促炎细胞因子诱导的。 文化。联合氧糖剥夺和兴奋性氨基 酸性给药将用于脑缺血的体外模型。 研究的目的是回答以下问题： 1.NO和活性氧物种如何相互作用以增加 兴奋性毒性及其细胞来源和酶来源是什么 活性氧？2.星形细胞诱导型一氧化氮合酶的诱导如何导致 增强胞外谷氨酸？具体地说，就是 细胞因子刺激改变谷氨酸e-通量和/或重新摄取将是 评估过了。这项研究的长期目标是更好地了解 炎性细胞因子参与的途径和机制 兴奋性中毒性神经元损伤的增强。改进的清晰度 这些事件可能导致新的治疗策略的发展。 旨在减缓以下神经细胞破坏的进展 卒中。

DESCRIPTION (Adapted from Applicant's Abstract): The pathophysiology of delayed neuronal death as it occurs hours or even days following cerebral ischemia is poorly understood. Recent study in animal models indicate that cytokine-inducible nitric oxide synthase (iNOS) is strongly induced in astrocytes surrounding areas of extensive neuronal degeneration 1 to 3 days following cerebral ischemic insult. Previous work by Dr Hewett demonstrated that NO derived from cytokine induction of astrocyte iNOS while not toxic alone dramatically increased the magnitude of N-methyl-D-aspartate and oxygen glucose deprivation induced neuronal injury in vitro suggesting that in vivo activation of iNOS could have the dangerous consequence of enhancing excitotoxic neuronal injury. Further it was shown that the potentiation was associated with an increase in extracellular glutamate levels and was dependent on reactive oxygen species as well as NO. Thus, the goal of this project is to elucidate specific cellular and molecular events by which astrocytic NO and reactive oxygen species contribute to the cytokine-mediated enhancement of excitotoxic neuronal injury. Experiments will be performed in vitro in primary cortical cell cultures. Astrocytic iNOS will be induced by exogenous addition of pro-inflammatory cytokines to cultures. Combined oxygen glucose deprivation as well as excitatory amino acid administration will be used in in vitro models of cerebral ischemia. Studies will be designed to answer the following questions: 1. How do NO and reactive oxygen species interact to augment excitotoxicity and what is the cellular source and enzymatic source of reactive oxygen species? 2. How does astrocytic iNOS induction lead to enhancement of extracellular glutamate? Specifically, the ability of cytokine stimulation to alter glutamate e-flux and/or re-uptake will be assessed. The long-term objectives of this study is to better understand the pathways and mechanisms by which inflammatory cytokines contribute to the enhancement of excitotoxic neuronal injury. Improved definition of these events could lead to the development of new therapeutic strategies designed to attenuate the progression of neuronal destruction following stroke.