Endoplasmic Reticulum Stress and Parkinson's Disease

内质网应激与帕金森病

• 批准号: 6835944
• 负责人: DAVID RON
• 金额: $ 2.69万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6835944
• 关键词: 6 hydroxydopamine; CHO cells; Caenorhabditis elegans; PC12 cells; Parkinson' s disease; SDS polyacrylamide gel electrophoresis; apoptosis; biological signal transduction; disulfide bond; endoplasmic reticulum; free radical oxygen; gene expression; gene mutation; glycosylation; immunocytochemistry; immunoprecipitation; laboratory mouse; mitochondria; neurons; neurotoxins; oxidative stress; protein degradation; protein folding; protein signal sequence; protein structure function

DESCRIPTION (provided by applicant) Recent observations suggest that abnormal conformations of proteins that are normal constituents of the dopaminergic neuron participate in death of this cell type in Parkinson Disease (PD). Some rare forms of PD can be linked to mutations that cause such proteotoxicity, either directly by affecting the primary structure of the protein converting it to a proteotoxin (e.g. a-SYN mutations) or indirectly, by affecting cellular processes that impact on the accumulation of proteotoxins (e.g. PARK2 mutations). However, such mutations are found in only a small fraction of PD patients, raising the question of how proteotoxicity is triggered in other cases. Recent experiments from our lab indicate that 6-hydroxydopamine and Rotenone, toxins implicated in experimental and environmental PD, cause an imbalance between the folding capacity of the endoplasmic reticulum (ER) and the load of client proteins placed on that organelle (so called ER stress). Uncompensated ER stress can promote proteotoxicity by competing for limited capacity of the ubiquitin proteasomal system and by producing ROS that can alter protein structure. Neurons are naturally prone to ER stress because of their extensive secretory activity and because of their highly elaborate membrane enclosed processes, which must be maintained by high rates of ER trafficking of client proteins. ER stress is normally counteracted by the unfolded protein response (UPR), an adaptive cellular signaling pathway that is activated specifically by ER stress. Impaired UPR signaling sensitizes cells specifically to the effect of ER stress. Therefore, we propose to test the role of ER stress in the development of PD by examining the effect of mutations that impair signaling in the UPR on an established model of experimental PD and on a component of genetic PD. We will determine if in mice lacking the key UPR gene, PERK dopaminergic neurons are hypersensitive to 6-hydroxydopamine. We will seek to identify the defect in ER function imparted by 6-hydroxydopamine and relate it, if possible, to the known ability of the toxin to inhibit mitochondrial complex-1. Finally, we will critically examine PARK2's role in ER-associated degradation of proteins. If the proposed experiments support a role for ER stress in the development of PD, this will effect a paradigmatic shift in our thinking about the pathogenesis of this common disorder.

描述（由申请人提供） 最近的观察表明，蛋白质的异常构象 多巴胺能神经元的正常成分参与了该神经元的死亡 帕金森病 (PD) 中的细胞类型。一些罕见的帕金森病可能与 导致这种蛋白质毒性的突变，或者直接影响 将其转化为蛋白毒素的蛋白质的一级结构（例如 a-SYN 突变）或间接地通过影响细胞过程来影响 蛋白毒素积累（例如 PARK2 突变）。然而，这样的突变 仅在一小部分 PD 患者中发现，这就提出了一个问题： 在其他情况下会引发蛋白质毒性。我们实验室最近的实验 表明 6-羟基多巴胺和鱼藤酮，与实验有关的毒素 和环境PD，导致折叠能力之间的不平衡 内质网 (ER) 及其上的客户蛋白负载 细胞器（所谓的 ER 应激）。未代偿的 ER 压力会促进 通过竞争泛素蛋白酶体的有限能力而产生蛋白质毒性 系统并通过产生可以改变蛋白质结构的ROS。神经元是 由于其广泛的分泌活动和 由于其高度复杂的膜封闭工艺，必须 由客户蛋白的高内质网运输率维持。 ER 应力为 通常会被未折叠蛋白反应（UPR）所抵消，这是一种适应性的反应。 内质网应激特异激活的细胞信号通路。 受损的 UPR 信号使细胞对 ER 的作用特别敏感 压力。因此，我们建议测试 ER 应激在发育中的作用 通过检查削弱 UPR 信号传导的突变对 PD 的影响 已建立的实验性 PD 模型和遗传性 PD 的一个组成部分。我们 将确定在缺乏关键 UPR 基因的小鼠中，PERK 多巴胺能神经元是否 对6-羟基多巴胺过敏。我们将努力找出其中的缺陷 6-羟基多巴胺赋予的 ER 功能，如果可能的话，将其与 已知该毒素具有抑制线粒体复合物-1 的能力。最后，我们将 严格检查 PARK2 在 ER 相关蛋白质降解中的作用。如果 拟议的实验支持 ER 应激在 PD 发展中的作用， 这将影响我们对发病机制的思考的范式转变 这种常见的疾病。