A novel neuroprotective strategy

项目摘要 本申请旨在研究病毒阻断肝细胞凋亡的机制是否可以 被翻译和优化以阻断损伤后的神经元细胞死亡。虽然有几个信号级联 负责脑卒中和相关疾病后神经退行性变化的 治疗人类病症的特征性的有效神经保护疗法仍然远离我们。因此，在本发明中， 旨在揭示新的神经保护策略的研究，如本文所述， 可能具有非常重要的意义。我们的实验室正在测试一个普遍的假设， 途径，由不同的有害刺激触发或由独特的生化信号级联组成， 需要一组共同的条件来优化操作。在过去的十年里，我们已经定义了一个神经元 以电压依赖性K+电流的稳健增强为特征的促凋亡信号级联。 这种现象通过为细胞死亡提供一个场所来确保细胞死亡程序的完成。 细胞质K+，建立蛋白酶和核酸酶活化的容许环境。干扰 导致细胞凋亡的K+电流浪涌的过程可以有效地阻断神经元细胞死亡。在 在哺乳动物皮层和中脑神经元中，电流浪涌由从头SNARE依赖性 Kv2.1编码的K+通道胞吐插入细胞膜。值得注意的是， 丙型肝炎病毒基因组RNA，即非结构蛋白5A（NS5A）的翻译和加工， 最近显示有效干扰Kv2.1介导的肝细胞凋亡K+电流，并抑制 肝细胞死亡。在初步研究中，我们观察到NS5A也可以用于拯救 这种蛋白质干扰神经元Kv2.1介导的凋亡K+电流 浪涌。在本申请中，我们打算（i）研究负责NS5A干扰的机制， Kv2.1功能性表达，和（ii）限定限制通道所必需的NS5A的分子结构域 功能这些后面的实验将建立可用于本发明的最小NS5A衍生序列。 新型神经保护探针的设计。我们研究计划的首要目标是设计新的 损伤后保护神经元的治疗策略。我们正在探索一部小说， 通过建设性地利用一种生物学策略来实现这一目标的方法，这种生物学策略可以阻止细胞死亡 并将其转化为治疗中风和其他形式的肝硬化的新方法。 神经变性

PROJECT SUMMARY This application aims to investigate whether a mechanism used by a virus to block hepatocyte apoptosis can be translated and optimized to block neuronal cell death following injury. Although several signaling cascades responsible for neurodegenerative changes following stroke and related disorders have been well characterized, effective neuroprotective therapies to treat human conditions continue to elude us. Thus, investigations designed to uncover novel neuroprotective strategies, such as those describe here, are potentially of very high significance. Our laboratory is testing the general hypothesis that distinct cell death pathways, triggered by diverse injurious stimuli or composed of unique biochemical signaling cascades, require a set of common conditions to operate optimally. Over the last ten years, we have defined a neuronal pro-apoptotic signaling cascade characterized by a robust enhancement of voltage dependent K+ currents. This phenomenon ensures the completion of cell death programs by providing a venue for the loss of cytoplasmic K+, establishing a permissive environment for protease and nuclease activation. Interfering with the processes responsible for the apoptotic K+ current surge can effectively block neuronal cell death. In mammalian cortical and midbrain neurons, the current surge is mediated by a de novo SNARE-dependent exocytotic insertion of Kv2.1-encoded K+ channels into the cell membrane. Remarkably, a product of the translation and processing of the hepatitis C virus genomic RNA, the non-structural protein 5A (NS5A), was recently shown to effectively interfere with Kv2.1-mediated apoptotic K+ currents in liver cells and inhibit hepatocyte cell death. In preliminary studies we observed that NS5A could also be employed to rescue neurons following injury and that this protein interferes with the neuronal Kv2.1-mediated apoptotic K+ current surge. In this application we intend to (i) investigate the mechanism responsible for NS5A interference with Kv2.1 functional expression, and (ii) define the molecular domains of NS5A necessary for restricting channel function. These latter experiments will establish the minimal NS5A-derived sequences that can be used for the design of novel neuroprotective probes. The overarching goal of our research program is to devise new therapeutic strategies to protect neurons following injury. We are exploring a novel, possibly groundbreaking approach to achieve this goal by constructively harnessing a biological strategy that evolved to block cell death in the liver and translating it towards the generation of novel methods to treat stroke and other forms of neurodegeneration.