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

• 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
• 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

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）：脊髓小脑共济失调7型（SCA 7）是一种常染色体显性遗传疾病，导致视网膜变性的视锥-视杆细胞营养不良形式。SCA 7患者遗传的突变是共济失调蛋白-7基因中的CAG/多聚谷氨酰胺（polyQ）重复扩增。SCA 7突变导致产生毒性polyQ扩增的共济失调蛋白-7。由于毒性基因产物驱动SCA 7中的所有后续疾病病理，因此最有吸引力的治疗范例是终止突变基因产物的表达。在这里，我们建议继续一个翻译研究计划，旨在产生治疗药物的SCA 7视网膜疾病，并可能为相关的SCA引起的CAG重复扩增突变。我们正在使用一种已经成功应用于减少毒性蛋白表达的策略来追求ataxin-7“基因沉默”：基于阿糖胞苷的敲低。为了实现这一转化研究计划的目标，我们已经建立了学术-工业合作伙伴关系。在与ISIS Pharmaceuticals（一家专门从事反义寡核苷酸（阿索）生产和单链siRNA（ss-siRNA）创建的公司）的密切合作中，我们确定了显着敲低ataxin-7表达的线索。基于这些体外结果，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验性玻璃体内注射。与注射稀释剂的眼睛相比，这些先导性玻璃体内注射产生注射抗共济失调蛋白-7阿索的眼睛的共济失调蛋白-7表达的稳健（> 0%）敲低。在SCA 7基因敲入小鼠中的进一步初步研究导致治疗眼中视网膜感光细胞中共济失调蛋白-7蛋白聚集体的显著减少。我们还鉴定了用于在来自患者的成纤维细胞系中等位基因选择性靶向polyQ扩增的共济失调蛋白-7的CAG重复靶向寡核苷酸。因此，我们提出两个目标：1）基于敲低的功效和眼毒性参数，我们将选择一种共济失调蛋白-7阿索，并在SCA 7敲入小鼠的右眼中进行共济失调蛋白-7阿索的玻璃体内注射，并在右眼中进行对照阿索/稀释剂的玻璃体内注射，以确定阿索递送是否可以预防或改善SCA 7视网膜变性。读数将包括共济失调蛋白-7聚集、视网膜组织学和视觉功能。一旦我们确定了有效的共济失调蛋白-7阿索，我们将重复试验以确认疗效，比较ASO治疗和对照治疗眼睛中的基因表达变化，确定在有症状的SCA 7小鼠中递送阿索是否可以阻止或逆转疾病进展，并评估共济失调蛋白-7阿索作为SCA 7小脑变性治疗的效用。2)在我们选择CAG重复靶向寡核苷酸后，我们将测试寡核苷酸是否可以预防或改善SCA 7基因敲入小鼠的视网膜变性，然后将寡核苷酸用于验证性研究、转录组表达分析、症状干预试验和评估作为SCA 7神经变性的治疗，应用与共济失调蛋白-7阿索类似的实验策略。在该项目结束时，我们将有能力与我们的行业合作者一起继续进行IND支持研究，作为人类SCA 7患者临床试验的前奏。