Liberation of Intracellular Zinc and Neuronal Cell Death

这项拨款提案代表了一项高产研究的第三次竞争性更新（16-20年） 研究与人类相关的基本细胞和分子信号通路的计划 神经退行性疾病在过去15年的资助，从这个赠款，我们的研究特点是 详细描述了将细胞内锌的氧化释放连接到神经元细胞死亡的信号级联，其使Kv2.1通道的质膜插入增加。这一过程介导了 细胞质钾，在编程期间最佳蛋白酶和核酸酶催化活性的必要步骤 和其他形式的细胞死亡。在目前的资助期内（11-15年），我们研究了 磷酸化事件导致突触融合蛋白依赖性胞吐插入Kv2.1进入神经元 损伤后的细胞膜。我们还研究了Kv2.1体树突状细胞簇的作用， 在凋亡期间占主导地位的膜通道插入枢纽。最重要的是，我们在体内建立了一个新的 通过开发一种细胞渗透肽来干预脑卒中损伤的关键神经保护方法 Kv2.1与突触融合蛋白的相互作用。我们的工作有力地表明，特异性靶向Kv2.1促进细胞， 死亡过程可以提供用于神经保护的机械驱动的新颖治疗策略。在这 我们建议通过以下方式果断推进这一战略目标： 新的神经保护肽和衍生的小分子类似物的性质， 突触融合蛋白/Kv2.1相互作用;（ii）建立原型神经保护工具，旨在分散Kv2.1 体树突簇，和（iii）设计一种创新的神经保护策略，将正常的 沉默基因的神经元，旨在表达Kv2.1靶向调节蛋白时，细胞是致命的 受伤了因此，我们采取了三项独特的、具有潜在变革性的战略， 前提是细胞死亡诱导途径需要一组共同的条件来最佳地运行。损失 细胞内钾离子通过Kv2.1介导的离子电流的激增可能构成广泛的，如果不是 普遍存在的，在许多类型的神经元中程序性细胞死亡的要求。因此，实验 这里描述的目的是翻译的细胞和分子途径，我们的特点是与 长期的资金从这个赠款，到合理的治疗方法，神经变性。

This grant proposal represents the third competitive renewal (Years 16-20) of a highly productive research program investigating fundamental cellular and molecular signaling pathways relevant to human neurodegenerative disorders. Over the last 15 years of funding from this grant, our studies have characterized in detail a signaling cascade connecting the oxidative liberation of intracellular zinc to a neuronal cell death-enabling increase in the plasma membrane insertion of Kv2.1 channels. This process mediates a loss of cytoplasmic potassium, a requisite step for optimal protease and nuclease catalytic activity during programmed and other forms of cell death. In the current funding period (Years 11-15), we have studied the phosphorylation events leading to the syntaxin-dependent exocytotic insertion of Kv2.1 into the neuronal plasma membrane following injury. We also investigated the role of Kv2.1 somatodendritic clusters as dominant membrane channel insertion hubs during apoptosis. Most importantly, we established a novel in vivo neuroprotective approach to stroke injury by developing a cell-permeant peptide that interferes with a critical Kv2.1 interaction with syntaxin. Our work strongly indicates that specifically targeting Kv2.1-facilitated cell death processes can provide mechanistically driven, novel therapeutic strategies for neuroprotection. In this application we propose to decisively move forward with this strategic objective by: (i) characterizing the properties of novel neuroprotective peptides and derived small molecule analogs targeting the syntaxin/Kv2.1 interaction; (ii) establishing prototypical neuroprotective tools aimed at dispersing Kv2.1 somatodendritic clusters, and (iii) devising an innovative neuroprotective strategy that transfers a normally silent gene to neurons, designed to express a Kv2.1-targeted modulatory protein when cells are lethally injured. We thus have adopted three unique and potentially transformative strategies, all based on the premise that cell death-inducing pathways require a set of common conditions to operate optimally. The loss of intracellular potassium via a surge of Kv2.1-mediated ionic currents may constitute a widespread, if not ubiquitous, requirement for programmed cell death in many types of neurons. As such, the experiments described here are aimed at translating the cellular and molecular pathways we have characterized with long-term funding from this grant, into rational therapeutic approaches to neurodegeneration.