Silencing C9or72 with rAAV Mediated RNAi

用 rAAV 介导的 RNAi 沉默 C9or72

• 批准号: 9042441
• 负责人: Robert H. Brown
• 金额: $ 36.05万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9042441
• 关键词: Amyotrophic Lateral Sclerosis; Antibodies; Brain; C9ORF72; Cell Line; Cells; Cerebellum; Cerebrum; Clinical Trials; Development; Disease; Dose; Effectiveness; Exons; Exposure to; Fibroblasts; Frontotemporal Dementia; Future; Gene Transduction Agent; Genes; Genetic; Genetic Transcription; Goals; Health; Human; In Vitro; Intervention; Intravenous; Introns; Investigation; Lead; Mediating; Messenger RNA; Methods; MicroRNAs; Modeling; Motor Neurons; Mus; Mutation; Nerve Degeneration; Neuraxis; Neurodegenerative Disorders; Neurons; Patients; Pattern; Peripheral; Phenotype; Primates; Proteins; RNA; RNA Interference; Recombinant adeno-associated virus (rAAV); Route; Safety; Sequence Homology; Series; Small RNA; Spinal Cord; Testing; Therapeutic; Toxic effect; Transcript; Transgenes; Transgenic Mice; Translating; Translations; Untranslated RNA; Viral Vector; Virus; Wild Type Mouse; autosomal dominant trait; clinical application; cytotoxic; effective therapy; gain of function; in vivo; knock-down; mRNA Precursor; member; mouse model; mutant; nervous system disorder; neuron loss; nonhuman primate; novel; research study; statistics; transcription factor

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a progressive, untreatable, uniformly fatal motor neuron disorder that sometimes develops concurrently with frontotemporal dementia (FTD). ALS is encountered in both sporadic (SALS) and familial (FALS) forms; about 10% of cases are transmitted as autosomal dominant traits. The cause of sporadic ALS is not known. Recently it was discovered that about 30-50% of FALS cases are caused by expansions of a non-coding hexanucleotide G4C2 expansion in the gene C9ORF72. These expansions are also detected in 10-20% of familial FTD, 10% of sporadic FTD and in ~5% of SALS. These statistics define the C9ORF72 G4C2 expansion as the most common cause of ALS. In the present study, we propose to use rAAV type Rh10 to introduce a microRNA to silence expression of the transcripts of C9ORF72 that harbor the offending G4C2 expansion. In Aim 1, we will screen, identify and optimize potential miRNAs in vitro. In Aim 2, we will further characterize the phenotype of our novel C9ORF72mutant transgenic mouse and investigate use of rAAVRh10-C9miRs to silencing the mutant C9 transgene and thereby mitigate the phenotype in this mouse. In Aim 3 we will investigate delivery and efficacy of the rAAVRh10-C9miRs in a non- human primate model as first step to translating this therapy to clinical application. Relevance: We believe that these studies will be highly relevant for several reasons. (1) There is a compelling unmet need for effective ALS treatments; this project focuses on the most common form of FALS, with applicability as well to some cases of SALS and FTD. (2) This investigation will develop the use of intrathecal rAAVRh10 as a gene therapy vector for the CNS; the intrathecal route is advantageous, permitting widespread delivery within the CNS with doses that are an order-of-magnitude lower than are required via intravenous delivery; and minimizing peripheral exposure to virus. (3) rAAV has not been used in human neurodegenerative disorders. The platform we propose to develop here should have broad applicability across a breadth of neurological disorders.

描述（由申请人提供）：肌萎缩侧索硬化症（ALS）是一种进行性、无法治疗、均致命的运动神经元疾病，有时与额颞叶痴呆（FTD）同时发生。 ALS 有散发性 (SALS) 和家族性 (FALS) 两种形式；约 10% 的病例以常染色体显性遗传特征传播。散发性 ALS 的病因尚不清楚。最近发现，大约 30-50% 的 FALS 病例是由基因 C9ORF72 中非编码六核苷酸 G4C2 扩展引起的。这些扩展也在 10-20% 的家族性 FTD、10% 的散发性 FTD 和约 5% 的 SALS 中检测到。这些统计数据将 C9ORF72 G4C2 扩展定义为 ALS 最常见的原因。 在本研究中，我们建议使用 Rh10 型 rAAV 引入 microRNA 来沉默含有违规 G4C2 扩展的 C9ORF72 转录本的表达。在目标 1 中，我们将在体外筛选、识别和优化潜在的 miRNA。在目标 2 中，我们将进一步表征新型 C9ORF72 突变转基因小鼠的表型，并研究使用 rAAVRh10-C9miR 来沉默突变 C9 转基因，从而减轻该小鼠的表型。在目标 3 中，我们将研究 rAAVRh10-C9miR 在非人灵长类动物模型中的递送和功效，作为将该疗法转化为临床应用的第一步。相关性：我们相信，由于多种原因，这些研究将具有高度相关性。 (1) 对有效的 ALS 治疗存在迫切的未满足需求；该项目重点关注最常见的 FALS 形式，也适用于 SALS 和 FTD 的某些情况。 (2) 本研究将开发鞘内注射 rAAVRh10 作为中枢神经系统基因治疗载体的用途；鞘内途径是有利的，允许在中枢神经系统内广泛递送，其剂量比静脉递送所需的剂量低一个数量级；并尽量减少外周病毒的暴露。 (3) rAAV尚未用于人类神经退行性疾病。我们建议在此开发的平台应该具有广泛的适用性，涵盖各种神经系统疾病。