Liberation of Intracellular Zinc and Neuronal Cell Death

描述(由申请人提供)已知囊泡性锌离子从突触前释放部位转移到注定要死亡的突触后细胞的细胞质中后，对神经元具有毒性。除了这种胞外来源的锌，我们还观察到这种金属可以通过硫醇氧化剂从细胞内的金属结合蛋白中释放出来。我们进一步证明，细胞内释放的锌离子是一种强大的神经元凋亡刺激因子。在这里，我们建议使用分子、细胞和整个动物的方法来评估细胞内锌离子的释放是否代表氧化应激后神经细胞死亡的共同特征。 这项建议的具体目的是：1.确定过氧亚硝酸盐和一氧化氮是否在体外引发细胞内锌释放所导致的神经毒性级联反应。2.确定细胞死亡途径中与细胞内锌释放相关的分子成分。3在轴突切断诱导的在体神经细胞死亡模型中，评价细胞内锌释放是否触发细胞凋亡。在这些目标中描述的实验将检验这一假设，即细胞内锌离子的释放是神经元损伤中细胞死亡的重要和普遍的触发因素。该研究计划的长期目标是提供额外的治疗靶点，以防止或最大限度地减少与氧化损伤相关的大量神经疾病中的神经细胞死亡。

DESCRIPTION (provided by the applicant) Vesicular Zn2+ is known to be toxic to neurons following its translocation from presynaptic release sites into the cytoplasm of postsynaptic cells that are destined to die. In addition to this extracellular source of Zn2+, we have observed that this metal can be released from intracellular metal binding proteins by thiol axidants. We have shown further that intracellularly liberated Zn2+ is a powerful apoptotic stimulus in neurons. Here, using molecular, cellular, and whole animal approaches, we propose to evaluate whether the release of intracellular Zn2+ represents a common feature in neuronal cell death following oxidative stress. The Specific Aims of this proposal are: 1. To determine whether peroxynitrite and nitric oxide trigger a neurotoxic cascade that results from the intracellular release of zinc in vitro. 2. To identify molecular components of the cell death pathway that are associated with the intracellular release of zinc in vitro. 3 To evaluate whether the intracellular release of zinc triggers apoptosis in an axotomy-induced in vivo model of neuronal cell death. Experiments described within these aims will test the hypothesis that the liberation of intracellular Zn2+ represents an important and ubiquitous trigger for cell death in neuronal injury. The long-term goal of this research program is to provide additional therapeutic targets to prevent or minimize neuronal cell death in the large number of neurological disorders associated with oxidative injury.