Poly(ADP-ribose) promotes the condensation and toxicity of C9orf72 arginine-rich dipeptide repeat proteins

聚（ADP-核糖）促进 C9orf72 富含精氨酸的二肽重复蛋白的缩合和毒性

• 批准号: 10448297
• 负责人: Tania France Gendron
• 金额: $ 58.25万
• 依托单位: MAYO CLINIC JACKSONVILLE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10448297
• 关键词: Age; Arginine; Attention; Autopsy; Behavioral; Binding; Biological Models; Biology; C9ORF72; Cell physiology; Cells; Cerebellum; Data; Development; Diagnosis; Dipeptides; Disease; Disease Pathway; Drosophila genus; Evaluation; Exhibits; Eye; Functional disorder; G3BP1 gene; Genes; Genetic; Gliosis; Goals; Health; Homologous Gene; Human; In Vitro; Investigation; Knock-out; Light; Mediating; Molecular; Motor Cortex; Mus; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neurons; Nuclear Pore Complex Proteins; Onset of illness; Pathogenesis; Pathology; Patients; Phenotype; Physical condensation; Play; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerases; Pre-Clinical Model; Production; Proteins; Proteomics; RNA; Ribosomes; Role; Tissues; Toxic effect; Transcript; Translation Initiation; Translations; biophysical properties; brain tissue; c9FTD/ALS; effective therapy; fly; frontal lobe; frontotemporal lobar dementia-amyotrophic lateral sclerosis; human tissue; in vivo; knock-down; member; mouse model; neurotoxicity; new therapeutic target; novel; nucleocytoplasmic transport; protein TDP-43; protein aggregation; sporadic amyotrophic lateral sclerosis; stem; stress granule; therapeutic target; therapy development

A GGGGCC hexanucleotide repeat expansion in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two devastating neurodegenerative diseases with no effective treatment. We have shown that transcripts of the expanded repeat undergo an unconventional mode of translation, resulting in the production of five dipeptide repeat proteins (DPRs). Our group and others demonstrated that DPRs form neuronal inclusions throughout the central nervous system of patients with C9orf72-associated ALS and FTD (“c9ALS/FTD”). The identification of this neuropathological hallmark shed new light on possible disease mechanisms, and our systematic assessment of DPRs in human tissues, along with their evaluation in mice and other preclinical models, indicate that the arginine-rich DPRs, poly(GR) and poly(PR), are especially toxic. Our data further suggest that this toxicity stems, at least in part, from the co-condensation and/or co-aggregation of these DPR proteins with proteins that regulate essential cellular functions, such as stress granule biology and nucleocytoplasmic transport. We have also shown that poly(GR) aggregation induces TDP-43 pathology, another hallmark feature of c9ALS/FTD and of the majority of sporadic ALS and FTD cases. Nevertheless, since poly(GR) and poly(PR) interact with more than 200 endogenous proteins, they are likely to adversely influence a host of cellular functions – a line of investigation that merits attention. Also of importance is determining the underlying factors that regulate poly(GR) and poly(PR) condensation and aggregation, and their interactions with other proteins. It is thus notable that our preliminary data show that poly(ADP-ribose) (PAR) promotes poly(GR) and poly(PR) condensation, and enhances their co-condensation or co-aggregation with disease-related proteins in vitro. Moreover, we observed that reducing PAR suppresses poly(GR)- or poly(PR)-mediated neurodegeneration in Drosophila. In light of these exciting findings, we hypothesize that PAR mediates the aggregation and toxicity of arginine-rich DPRs and the proteins to which they bind. Thus, the goal of the proposed project is to determine how PAR does so. To this end, we will identify proteins that interact with poly(GR) or poly(PR) in a PAR-dependent fashion, and investigate the contribution of PAR to arginine-rich DPR aggregation and toxicity using multiple preclinical models and brain tissues from C9orf72 expansion carriers. Overall, by availing the diverse expertise of our team members, we endeavor to elucidate the role of PAR and arginine-rich DPR proteins in c9ALS/FTD pathogenesis, and thus uncover novel therapeutic targets to expedite the development of effective treatments for c9ALS/FTD.

GGGGCC六核苷酸在C9orf72基因中的重复膨胀是最常见的遗传原因 肌萎缩性侧索硬化症（ALS）和额颞痴呆（FTD），两个毁灭性神经退行性的 没有有效治疗的疾病。我们已经表明，扩展的重复的成绩单经历了 非常规翻译模式，导致产生五种二肽重复蛋白（DPRS）。我们的 小组和其他人表明，DPR在整个中枢神经系统中形成神经元内包含 C9ORF72相关的ALS和FTD患者（“ C9ALS/FTD”）。这种神经病理学的识别 Hallmark对可能的疾病机制和我们对人类DPR的系统评估开发了新的启示 组织以及它们在小鼠和其他临床前模型中的评估表明，富含精氨酸的DPRS， poly（gr）和聚（PR），特别有毒。我们的数据进一步表明，这种毒性至少部分部分是 从这些DPR蛋白与调节必需的蛋白的共凝结和/或共聚集 细胞功能，例如应力颗粒生物学和核质胞质转运。我们还表明 poly（gr）聚集诱导TDP-43病理学，C9als/ftd的另一个标志特征和大多数的特征 散发性ALS和FTD病例。然而，由于poly（gr）和poly（pr）与200多个 内源性蛋白质，它们可能会对许多细胞功能产生不利影响 - 研究线 这值得关注。同样重要的是确定调节多（gr）和 聚（PR）缩合和聚集，及其与其他蛋白质的相互作用。因此，值得注意的是我们 初步数据表明，poly（adp-ribose）（PAR）促进poly（gr）和poly（pr）凝结，并且 增强其在体外与疾病相关蛋白的共凝结或共聚集。而且，我们 观察到减少PAR抑制果蝇中的聚（GR）或聚（PR）介导的神经退行性。在 这些令人兴奋的发现的光线，我们假设par介导了精氨酸富集的聚集和毒性 DPRS及其结合的蛋白质。这是拟议项目的目标是确定如何 这样做。为此，我们将确定与poly（gr）或pry（pr）相互依赖的蛋白质 时尚，并研究PAR对精氨酸富的DPR聚集和毒性的贡献 C9ORF72膨胀载体的临床前模型和脑组织。总体而言，利用潜水员的专业知识 在我们的团队成员中，我们努力阐明PAR和精氨酸DPR蛋白在C9ALS/FTD中的作用 发病机理，因此发现了新型的治疗靶标，以加快有效治疗的发展 对于C9ALS/FTD。