Molecular mechanism of dipeptide repeat protein production from hexanucleotide repeats in C9ORF72-related ALS and FTD

C9ORF72相关ALS和FTD中六核苷酸重复产生二肽重复蛋白的分子机制

• 批准号: 10378768
• 负责人: Shuying Sun
• 金额: $ 35.82万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10378768
• 关键词: Affect; Amyotrophic Lateral Sclerosis; Antisense RNA; Biochemical; C9ORF72; CRISPR screen; CRISPR/Cas technology; Candidate Disease Gene; Cell Nucleus; Cells; Cytoplasm; Cytoplasmic Inclusion; Cytosol; Dipeptides; Disease; Event; Frontotemporal Dementia; Gene-Modified; Genes; Genetic; Genetic Screening; Genomics; Goals; Human; Induced pluripotent stem cell derived neurons; Inherited; Introns; Knock-out; Link; Mediating; Molecular; Nerve Degeneration; Neurodegenerative Disorders; Nuclear Export; Nuclear RNA; Nucleotides; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Patients; Phenotype; Process; Production; Proteins; RNA; RNA Processing; RNA Splicing; Reading Frames; Regulation; Regulatory Element; Reporter; Series; System; Techniques; Technology; Testing; Therapeutic; Tissues; Toxic effect; Translating; Translations; Untranslated RNA; base; frontotemporal lobar dementia-amyotrophic lateral sclerosis; genome-wide; induced pluripotent stem cell; insight; mRNA Precursor; novel; nucleocytoplasmic transport; prevent; protein expression; research and development; screening; stem cell model; therapeutic target; tool

PROJECT SUMMARY Hexanucleotide repeat expansion in a non-coding region of C9orf72 is the most common genetic cause of both amyotrophic lateral sclerosis (ALS) and frontal temporal dementia (FTD). One potential pathogenic mechanism is the aberrant accumulation of dipeptide repeat (DPR) proteins produced by repeat-associated non-AUG (RAN) translation in all six reading frames (poly-GA, poly-GR, poly-PA, poly-PR and poly-PG) of both sense and antisense RNAs. Abnormal cytoplasmic inclusions of these DPR proteins have been found in C9ORF72 patient tissues and cells. Several lines of evidence indicate that some forms of the DPR proteins can be pathogenic, yet little is known how the DPRs are generated from the expanded repeats. The goal of this proposal is to understand the molecular mechanisms and identify genetic modifiers of DPR production from both sense and antisense repeats, combining the genome-scale CRISPR/Cas9 knockout screening technology with biochemical and molecular approaches. We will primarily focus on two major steps of repeat RNA processing that could influence the final protein expression level: RNA nuclear export and RAN translation. We will dissect the molecular pathways of nuclear export for both sense and antisense repeats, what factors mediate this process, and how this is affected by C9-mediated toxicity on nucleocytoplasmic transport. We will decipher the molecular mechanisms of C9 RAN translation, and examine whether there are common modifiers between sense and antisense repeats. Altogether, these studies can provide novel insights on how DPRs are produced from C9 repeats and what approaches can be taken to prevent it. This will guide the development of research tools to understand how DRPs contribute to the disease pathogenesis. It will also possibly provide potential therapeutic targets to reduce DPR-mediated toxicity by inhibiting their production.

项目总结 C9orf72非编码区的六核苷酸重复扩增是导致这两种疾病最常见的遗传原因 肌萎缩侧索硬化症(ALS)和额叶颞叶痴呆(FTD)。一种潜在的致病机制 二肽重复序列(DPR)蛋白的异常积累是由重复相关的非AUG (RAN)在两个正义的所有六个阅读框架(PolyGA、PolyGR、PolyPA、PolyPR和PolyPG)中的翻译 和反义RNA。在C9ORF72中发现了这些DPR蛋白的异常胞质包涵体 患者组织和细胞。几条证据表明，某些形式的DPR蛋白可以是 致病，但几乎不知道dprs是如何从扩增的重复序列中产生的。这样做的目的是 建议了解DPR产生的分子机制并确定遗传修饰物 正义和反义重复，结合基因组规模的CRISPR/Cas9基因敲除筛选技术 用生化和分子方法。我们将主要关注重复RNA的两个主要步骤 可能影响最终蛋白质表达水平的处理：RNA核输出和RAN翻译。我们 将剖析正义和反义重复的核出口的分子途径，哪些因素 调节这一过程，以及C9介导的核质转运毒性如何影响这一过程。我们会 破译C9 RAN翻译的分子机制，并检查是否有共同的修饰因素 在正义和反义重复之间。总之，这些研究可以提供关于dprs是如何的新的见解。 由C9重复产生，以及可以采取什么方法来防止它。这将指导...的发展 研究工具，以了解DRP如何在疾病发病机制中做出贡献。它还可能提供 潜在的治疗靶点，通过抑制DPR的产生来减少DPR介导的毒性。

项目成果

Measuring Repeat-Associated Non-AUG (RAN) Translation.

测量重复相关的非 AUG (RAN) 翻译。

• DOI: 10.1007/978-1-0716-1975-9_8
• 发表时间: 2022
• 期刊: Methods in molecular biology (Clifton, N.J.)
• 作者: Wang,Shaopeng;Sun,Shuying
• 通讯作者: Sun,Shuying

Translation dysregulation in neurodegenerative diseases: a focus on ALS.

• DOI: 10.1186/s13024-023-00642-3
• 发表时间: 2023-08-25
• 期刊: MOLECULAR NEURODEGENERATION
• 影响因子: 15.1
• 作者: Wang, Shaopeng;Sun, Shuying
• 通讯作者: Sun, Shuying

DDX3X overexpression decreases dipeptide repeat proteins in a mouse model of C9ORF72-ALS/FTD.

DDX3X 过表达会减少 C9ORF72-ALS/FTD 小鼠模型中的二肽重复蛋白。

• DOI: 10.1016/j.expneurol.2024.114768
• 发表时间: 2024
• 期刊: Experimental neurology
• 影响因子: 5.3
• 作者: Fu,Xiujuan;Zhang,Zhe;Hayes,LindseyR;Wright,Noelle;Asbury,Julie;Li,Shelley;Ye,Yingzhi;Sun,Shuying
• 通讯作者: Sun,Shuying