Ataxin-7 oligonucleotide knock-down to treat SCA7 retinal and cerebellar disease

Ataxin-7 寡核苷酸敲低治疗 SCA7 视网膜和小脑疾病

基本信息

批准号：
9321472
负责人：
ALBERT R LA SPADA
金额：
$ 24.41万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2018-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9321472
关键词：
Alleles Antisense Oligonucleotides Brain Stem CAG repeat Catalogs Categories Cell Line Cerebellar Ataxia Cerebellar Diseases Cerebellar degeneration Cerebellum Clinical Trials Collaborations Contralateral Degenerative Disorder Disease Disease Progression Evaluation Eye Fibroblasts Functional disorder Funding Gene Expression Gene Expression Alteration Gene Proteins Gene Silencing Genes Genetic Transcription Goals Histology Human In Vitro Industrialization Inherited Injectable Injection of therapeutic agent Intervention Trial Knock-in Mouse Lead Methods Molecular Mus Mutation Nerve Degeneration Oligonucleotides Pathogenesis Pathology Patients Pharmacologic Substance Photoreceptors Pilot Projects Positioning Attribute Production Program Development Proteins Reagent Retina Retinal Retinal Degeneration Retinal Diseases Retinal Photoreceptors Retinitis Pigmentosa Rhodopsin Role SCA7 protein Series Small Interfering RNA Techniques Testing Therapeutic Therapeutic Agents Toxic effect Type 7 Spinocerebellar Ataxia Validation Vision Visual Wild Type Mouse Work ataxin-1 base experimental study gene product in vivo industry partner intravitreal injection knock-down member misfolded protein mouse model mutant polyglutamine preclinical trial prevent protein aggregate protein aggregation protein expression public health relevance retinal neuron stem therapy development transcriptome translational research program

项目摘要

DESCRIPTION (provided by applicant): Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder that results in a cone-rod dystrophy form of retinal degeneration. The mutation inherited by SCA7 patients is a CAG/polyglutamine (polyQ) repeat expansion in the ataxin-7 gene. The SCA7 mutation results in production of a toxic polyQ-expanded ataxin-7 protein. Since the toxic gene product drives all subsequent disease pathology in SCA7, the most attractive therapeutic paradigm is to terminate expression of the mutant gene product. Here we propose continuation of a translational research program intended to yield therapeutic agents for SCA7 retinal disease, and potentially for related SCAs caused by CAG repeat expansion mutations. We are pursuing ataxin-7 "gene silencing" using a strategy that has already been successfully applied to reduce the expression of a toxic protein: oligonucleotide-based knock-down. To achieve the goals of this translational research program, we have created an academic-industrial partnership. In close collaboration with ISIS Pharmaceuticals, a company that specializes in anti-sense oligonucleotide (ASO) production and single-stranded siRNA (ss-siRNA) creation, we identified leads that markedly knock-down ataxin-7 expression. Based upon these in vitro results, we selected leads for in vivo validation, and performed pilot intra-vitreal injections in wild-type mice. These pilot intra-vitreal injections yielded robust (> 0%) knock-down of ataxin-7 expression for eyes injected with anti-ataxin-7 ASO, in comparison to eyes injected with diluent. Further pilot studies in SCA7 knock-in mice resulted in significant reductions in ataxin-7 protein aggregates in retinal photoreceptor cells in treated eyes. We also identified CAG-repeat targeting oligonucleotides for allele-selective targeting of polyQ-expanded ataxin-7 in fibroblast cell lines from patients. We therefore propose two aims: 1) Based upon efficacy of knock-down and ocular toxicity parameters, we will select one ataxin-7 ASO and perform intra-vitreal injections of ataxin-7 ASO in the right eye and control ASO/diluent in the let eye of SCA7 knock-in mice to determine if ASO delivery can prevent or ameliorate SCA7 retinal degeneration. Read-outs will include ataxin-7 aggregation, retinal histology, and visual function. Once we identify an efficacious ataxin-7 ASO, we will repeat the trial to confirm efficacy, compare gene expression alterations in ASO-treated and control-treated eyes, determine if ASO delivery in symptomatic SCA7 mice can stop or reverse disease progression, and evaluate the utility of the ataxin-7 ASO as a therapy for SCA7 cerebellar degeneration. 2) After we select a CAG-repeat targeting oligonucleotide, we will test if the oligonucleotide can prevent or ameliorate retinal degeneration in SCA7 knock-in mice, and then advance the oligonucleotide for confirmatory studies, transcriptome expression analysis, symptomatic intervention trials, and evaluation as a therapy for SCA7 neurodegeneration, applying similar experimental strategies as with the ataxin-7 ASO. At the conclusion of this project, we will be well positioned to proceed with IND-enabling studies with our industrial collaborator, as a prelude to a clinical trial in humn SCA7 patients.

描述（由申请人提供）：脊髓小脑性共济失调 7 型（SCA7）是一种常染色体显性遗传疾病，可导致视锥杆营养不良形式的视网膜变性。 SCA7 患者遗传的突变是 ataxin-7 基因中的 CAG/聚谷氨酰胺 (polyQ) 重复扩增。 SCA7 突变导致产生有毒的 PolyQ 扩展的 ataxin-7 蛋白。由于有毒基因产物驱动SCA7中所有后续疾病病理，因此最有吸引力的治疗范例是终止突变基因产物的表达。在此，我们建议继续开展一项转化研究计划，旨在产生治疗 SCA7 视网膜疾病的药物，并可能治疗由 CAG 重复扩增突变引起的相关 SCA。我们正在使用一种已成功应用于减少有毒蛋白表达的策略来追求ataxin-7“基因沉默”：基于寡核苷酸的敲低。为了实现这一转化研究计划的目标，我们建立了学术与工业合作伙伴关系。 ISIS Pharmaceuticals 是一家专门从事反义寡核苷酸 (ASO) 生产和单链 siRNA (ss-siRNA) 创建的公司，通过与 ISIS Pharmaceuticals 的密切合作，我们发现了能够显着降低 ataxin-7 表达的先导化合物。根据这些体外结果，我们选择了用于体内验证的引线，并在野生型小鼠中进行了试点玻璃体内注射。与注射稀释剂的眼睛相比，这些试点玻璃体内注射对注射抗ataxin-7 ASO的眼睛产生了强烈（> 0%）ataxin-7表达的敲低。在 SCA7 敲入小鼠中进行的进一步初步研究导致接受治疗的眼睛视网膜感光细胞中的 ataxin-7 蛋白聚集体显着减少。我们还鉴定了 CAG 重复靶向寡核苷酸，用于等位基因选择性靶向患者成纤维细胞系中的 PolyQ 扩增的 ataxin-7。因此，我们提出两个目标：1）根据击倒效果和眼毒性参数，我们将选择一种ataxin-7 ASO，并在右眼进行ataxin-7 ASO玻璃体内注射，并在右眼进行对照ASO/稀释剂。让 SCA7 敲入小鼠的眼睛确定 ASO 递送是否可以预防或改善 SCA7 视网膜变性。读数将包括 ataxin-7 聚集、视网膜组织学和视觉功能。一旦我们确定了有效的 ataxin-7 ASO，我们将重复试验以确认功效，比较 ASO 治疗和对照治疗眼睛的基因表达变化，确定有症状的 SCA7 小鼠中 ASO 递送是否可以阻止或逆转疾病进展，并评估ataxin-7 ASO 作为 SCA7 小脑变性疗法的用途。 2）选择CAG重复序列靶向寡核苷酸后，我们将测试该寡核苷酸是否可以预防或改善SCA7敲入小鼠的视网膜变性，然后将该寡核苷酸进行验证性研究、转录组表达分析、对症干预试验和评估作为 SCA7 神经变性的治疗方法，采用与 ataxin-7 ASO 类似的实验策略。在该项目结束时，我们将能够与我们的工业合作者一起进行 IND 启用研究，作为人类 SCA7 患者临床试验的前奏。