Using RNA signatures for therapy development in neurodegeneration due to C9orf72 expansions

使用 RNA 特征开发 C9orf72 扩展引起的神经退行性疾病的治疗方法

• 批准号: 8921307
• 负责人: Clotilde Lagier-Tourenne
• 金额: $ 3.49万
• 依托单位: LUDWIG INSTITUTE FOR CANCER RES LTD
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8921307
• 关键词: Affect; Amyotrophic Lateral Sclerosis; Antisense Oligonucleotides; Binding; C9ORF72; Cells; Chemicals; Clinical Trials; Collaborations; Consensus; Dipeptides; Disease; Employee Strikes; Engineering; FDA approved; Familial Amyotrophic Lateral Sclerosis; Fibroblasts; Frontotemporal Dementia; Genes; Genetic; Genetic Transcription; Genomic approach; Health; High-Throughput Nucleotide Sequencing; Human; In Vitro; Individual; Link; Mediating; Messenger RNA; Methods; Molecular Profiling; Motor Cortex; Motor Neurons; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Play; Preclinical Drug Evaluation; Process; Production; Property; Proteins; RNA; RNA Processing; RNA Splicing; RNA-Binding Proteins; Reporting; Role; Seminal; Spinal; System; Testing; Therapeutic; Toxic effect; Transcript; Translating; Translations; Untranslated RNA; Work; cost effective; cytotoxic; cytotoxicity; design; drug efficacy; gain of function; genome editing; high throughput screening; induced pluripotent stem cell; innovation; loss of function; novel therapeutics; screening; small molecule; therapeutic development; therapy development

DESCRIPTION (provided by applicant): RNA processing alterations are increasingly recognized to play a crucial role in the pathogenesis of a wide range of diseases including two devastating neurodegenerative conditions, amyotrophic lateral sclerosis (ALS) and frontal temporal dementia (FTD). The seminal discovery in 2011 of a hexanucleotide expansion in the C9orf72 gene as the most common cause of familial ALS and FTD significantly changed our perspective of these neurodegenerative diseases. The pathogenic mechanisms of this expansion are not yet understood. However recent lines of evidence, including from my own work, strongly support a gain of toxic property by accumulation of repeat-containing RNAs that are bidirectionally transcribed from the C9orf72 locus. Independent reports of RNA changes in fibroblasts, neurons derived from iPS cells and motor cortex from C9orf72 patients have offered evidence that RNA processing misregulation accompanies C9orf72 disease. However, it is still unresolved whether these RNA alterations are induced by the functional disruption of one or more RNA binding proteins sequestered into RNA foci or induced by another cytotoxic mechanism such as the striking accumulation of dipeptide repeat proteins translated from expanded RNAs that was recently reported in C9orf72 patients. In this project, I propose to define a set of alterations in mRNA processing that delineate a disease-dependent signature and that will serve as functional readouts to distinguish among current hypotheses for disease mechanism underlying C9orf72 ALS/FTD. By using genomic approaches optimized for precise identification of splicing and expression changes and human neurons specifically engineered to individually explore toxic mechanisms currently proposed, my group will determine which factor(s) drive the emergence of RNA processing alterations in C9orf72 disease. In particular, we will test the hypothesis that RNA alterations are induced either by sense or antisense repeat- containing RNAs. We will also use a functional screen to determine whether C9orf72-related RNA alterations are driven by reduced activity of one or more RNA binding proteins, including the proteins recently found to interact with the C9orf72 expanded repeats. Finally, my team will use the C9orf72 molecular signature to screen therapeutic compounds. Indeed, we and others have already established that antisense oligonucleotides (ASOs) targeting C9orf72 transcripts efficiently reduce pathological RNA foci in patient cells. I now propose to determine whether degradation of expanded RNAs transcribed from either the sense or antisense directions (or both), is necessary to restore RNA processing alterations linked to C9orf72 disease, an approach that may provide crucial information for the design of a clinical trial using ASOs in C9orf72 ALS/FTD patients. Disease-related RNA signatures will also serve as readouts to screen new therapeutic compounds in neurons directly derived from patient fibroblasts. Indeed, instead of using a single target RNA to determine drug efficacy, we will use quantitative analysis of a large panel of genes perturbed by C9orf72 expansions to identify small molecules that can intervene with disease-linked pathways to restore levels of the most affected RNAs.

描述（由申请人提供）：越来越多的人认识到RNA加工改变在多种疾病的发病机制中起关键作用，包括两种破坏性神经退行性疾病，肌萎缩性侧索硬化症（ALS）和额颞叶痴呆（FTD）。2011年的开创性发现C9 orf 72基因中的六核苷酸扩增是家族性ALS和FTD的最常见原因，这显著改变了我们对这些神经退行性疾病的看法。这种扩张的致病机制尚不清楚。然而，最近的证据，包括我自己的工作，强烈支持通过积累从C9 orf 72位点双向转录的含重复序列的RNA获得毒性。来自C9 orf 72患者的成纤维细胞、iPS细胞衍生的神经元和运动皮层中的RNA变化的独立报告提供了RNA加工失调伴随C9 orf 72疾病的证据。然而，它仍然是未解决的，这些RNA的变化是由一个或多个RNA结合蛋白的功能中断，隔离到RNA病灶或诱导的另一种细胞毒性机制，如显着积累的二肽重复蛋白翻译的扩展RNA，最近报道在C9 orf 72患者。在这个项目中，我建议定义一组mRNA加工的改变，描绘一个疾病依赖的签名，并将作为功能读数，以区分目前的疾病机制的基础C9 orf 72 ALS/FTD的假设。通过使用优化的基因组方法精确识别剪接和表达变化，以及专门设计用于单独探索目前提出的毒性机制的人类神经元，我的团队将确定哪些因素驱动C9 orf 72疾病中RNA加工改变的出现。特别地，我们将检验RNA改变是由含有正义或反义重复序列的RNA诱导的假设。我们还将使用功能筛选来确定C9 orf 72相关的RNA改变是否由一种或多种RNA结合蛋白的活性降低驱动，包括最近发现的与C9 orf 72扩增重复序列相互作用的蛋白质。最后，我的团队将使用C9 orf 72分子标记来筛选治疗化合物。事实上，我们和其他人已经确定靶向C9 orf 72转录物的反义寡核苷酸（ASO）有效地减少患者细胞中的病理性RNA病灶。我现在建议确定从正义或反义方向（或两者）转录的扩增RNA的降解是否是恢复与C9 orf 72疾病相关的RNA加工改变所必需的，这种方法可能为在C9 orf 72 ALS/FTD患者中使用ASO的临床试验设计提供关键信息。疾病相关的RNA特征也将作为读数，在直接来源于患者成纤维细胞的神经元中筛选新的治疗化合物。事实上，我们将使用C9 orf 72扩增干扰的大量基因的定量分析来确定可以干预疾病相关通路以恢复最受影响的RNA水平的小分子，而不是使用单一靶RNA来确定药物疗效。