Liberation of Intracellular Zinc and Neuronal Cell Death

描述(由申请人提供)：在中风、创伤和癫痫等神经退行性疾病中，细胞锌调节失调与神经元损伤密切相关。我们的小组首次提出，氧化和亚硝化应激从细胞内结合蛋白中释放出的锌代表着在这些和其他神经系统疾病中激活神经细胞死亡过程中的关键和普遍存在的成分。在这笔赠款的第一个资助期进行的工作中，我们描述了伴随着细胞内锌释放的细胞死亡信号级联，并在体内证明了在没有突触锌释放的情况下，这种金属在神经元内的损伤积累。几乎所有最初提出的实验的完成和发表使我们能够继续扩大我们在这一新颖和令人兴奋的研究领域的工作。在这一竞争性更新应用中，我们建议：1)建立细胞内释放锌激活特定的MAPK依赖的细胞死亡信号通路的机制。通过这些研究，我们的目标是最终表征锌可以启动不同信号转导过程的过程。2)探讨锌调节神经元基因表达的因素，以解决影响锌缓冲系统的条件，最终影响锌细胞的动态平衡。这些研究旨在阐明锌介导的神经元基因表达的基本特性，这是一个相对未被探索但至关重要的研究领域。3)确定体内细胞内锌释放所激活的分子细胞死亡途径，揭示体内锌释放的内源性刺激。我们的长期目标是详细描述细胞内锌释放后导致神经细胞死亡的分子信号级联反应。因此，这些研究的结果可能会为与氧化和亚硝化性损伤相关的大量神经退行性疾病的治疗干预提供新的途径。公共卫生相关性：这些研究的结果将提供有关导致包括中风、创伤和癫痫在内的一系列神经疾病的细胞机制的基本信息。有了这些信息，我们希望发现新的治疗策略来防止或阻止这些和其他神经退行性疾病的进展。

DESCRIPTION (provided by applicant): Dysregulation of cellular Zn2+ has been tightly linked to neuronal injury in neurodegenerative conditions present in stroke, trauma and epilepsy. Our group first suggested that Zn2+ released from intracellular binding proteins by oxidative and nitrosative stress represents a critical and ubiquitous component in the activation of neuronal cell death processes in these and other neurological disorders. In work performed during the first funding period of this grant, we characterized cell death signaling cascades accompanied by intracellular Zn2+ liberation, and demonstrated in vivo injurious intraneuronal accumulation of this metal in the absence of synaptic Zn2+ release. The completion and publication of nearly all of the originally proposed experiments has allowed us to continue to expand our work in this novel and exciting area of research. In this competitive renewal application we propose: 1) To establish the mechanism by which intracellular Zn2+ release activates specific MAPK-dependent cell death signaling pathways. With these studies, we aim to eventually characterize the process by which Zn2+ can initiate divergent signaling processes. 2) To investigate the factors that modulate Zn2+-regulated neuronal gene expression in order to resolve conditions affecting Zn2+ buffering systems and, ultimately, Zn2+ cellular homeostasis. These studies aim to elucidate the fundamental properties of Zn2+-mediated gene expression in neurons, a relatively unexplored but critically important area of research. And 3) to determine the molecular cell-death pathway activated by intracellular Zn2+ release in vivo and uncover the endogenous stimulus for the liberation of this metal. Our long-term objectives are to characterize in detail the molecular signaling cascades leading to neuronal cell death following the liberation of intracellular Zn2+. As such, results of these studies will likely generate new avenues for therapeutic intervention in the large number of neurodegenerative disorders associated with oxidative and nitrosative injury. PUBLIC HEALTH RELEVANCE: Results from these studies will provide fundamental information about the cellular mechanisms responsible for a host of neurological disorders, including stroke, trauma and epilepsy. With this information, we hope to uncover novel therapeutic strategies to prevent or halt the progression of these and other neurodegenerative conditions.