RNAi therapy for Huntingtons disease: safety & efficacy in the nonhuman primate

亨廷顿病的 RNAi 疗法：安全性

• 批准号: 7873076
• 负责人: Jodi L. McBride
• 金额: $ 8.99万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7873076
• 关键词: 18q; Adult; Affect; Aggressive behavior; Alleles; Animals; Anxiety; Area; Behavioral; Behavioral Assay; Binding; Biological Assay; Brain; Brain region; CAG repeat; Chorea; Clinic; Cognition; Cognitive; Cognitive deficits; Corpus striatum structure; Dancing; Data; Development; Disease; Emotional; Emotional Disturbance; Emotions; Evaluation; Exons; Functional disorder; Genes; Genetic; Genetic Polymorphism; Glutamine; Human; Huntington Disease; In Vitro; Injection of therapeutic agent; Knockout Mice; Left; Longevity; Macaca mulatta; Magnetic Resonance Imaging; Mediating; Mental Depression; Messenger RNA; Methods; MicroRNAs; Modeling; Molecular; Monkeys; Motor; Mus; Mutate; Neck; Nerve Degeneration; Neurodegenerative Disorders; Nucleotides; Pathology; Patients; Play; Postdoctoral Fellow; Prevention; RNA Interference; Recombinant adeno-associated virus (rAAV); Recombinants; Research; Research Personnel; Rodent Model; Role; Safety; Short-Term Memory; Symptoms; Testing; Therapeutic; Therapeutic Effect; Toxic effect; Training; Transgenic Mice; United States; Viral; Viral Vector; Virus; caudate nucleus; design; experience; gain of function; human Huntingtin protein; in vivo; limb movement; motor control; motor deficit; mutant; neuropathology; nonhuman primate; novel; pre-clinical; prevent; programs; psychologic; public health relevance; putamen; response

DESCRIPTION (provided by applicant): Huntington's disease (HD) is a fatal, neurodegenerative disorder resulting from an expanded tri-nucleotide repeat (CAG) in exon 1 of the HD gene (HTT). The glutamine expansion in the encoded protein, huntingtin (HTT) confers a toxic gain of function, causing degeneration of neurons in many brain regions, particularly in the striatum. Because these brain regions are involved with various aspects of motor programming and cognition, HD patients experience many symptoms including chorea (involuntary dance-like movements of the limbs and neck), loss of short-term memory and emotional disturbances that can include anxiety, depression and aggression. RNA interference (RNAi) has recently emerged as a leading candidate approach to reduce expression of disease genes by degrading the encoding mRNA. While normal huntingtin plays a vital role in development, we have demonstrated that a partial (60%) non-allele specific reduction in HTT expression is both well tolerated and therapeutically beneficial in adult HD transgenic mice. Here, we propose to test the efficiency, safety and therapeutic benefit of this approach in the nonhuman primate (NHP) as a pre-clinical step towards developing RNAi as a therapy for HD patients. We first aim to characterize the efficiency and safety of non-allele specific RNAi targeting HTT mRNA in the normal NHP brain as a proof-of-principle. Rhesus macaques (n=4) will receive unilateral, stereotaxic injections into the striatum of a recombinant viral vector that expresses mi2.4 (rAAV-mi2.4), a HTT-specific microRNA. The opposite hemisphere will be injected with a control miRNA (rAAV-miMIS) that does not reduce HTT expression. Animals will undergo behavioral evaluation to assess the efficacy and tolerability of this approach. Three months post-injection, animals will be euthanized and brains will be examined for silencing efficiency and several different safety profiles. Next, we aim to establish a NHP model of HD that includes motor dysfunction, cognitive deficits and emotional manifestations. Rhesus monkeys will receive injections into the striatum of a virus expressing a fragment of mutant HTT (mHTT) with 82 CAG repeats (rAAV-mHTT82Q, n=4) or a control fragment of mHTT with only 18 repeats (rAAV-mHTT-18Q, n=4). This strategy has been previously utilized to create a successful rodent model of HD. Animals will evaluated monthly on a variety of motor, cognitive and psychological assays. Six months post- injection, animals will be euthanized and their brains will be analyzed for signs of HD pathology. Lastly, we aim to test the therapeutic benefit of RNAi in the NHP model of HD. NHPs will be co-injected into the striatum with rAAV-mi2.4 (n=4) or rAAV-miMIS (n=4) along with rAAV-mHTT82Q. Animals will be evaluated monthly on a variety of motor, cognitive and psychological assays. Upon sacrifice at 6 months post-injection, brains will be analyzed for the prevention of HD-related pathology. Together, these studies will assess the safety and therapeutic benefit of RNAi in the NHP brain. The studies proposed here, along with the didactic and applied training, will be invaluable in assisting my transition from a post-doctoral fellow to an independent investigator. PUBLIC HEALTH RELEVANCE: The proposed set of studies aims at testing the benefit of RNA interference as a potential therapy for Huntington's disease (HD). There is no cure for this devastating, fatal disease and currently 30,000 people are affected in the United States alone. Testing the utility of RNA interference in a nonhuman primate model of HD is a necessary and key step towards its potential use in the clinic.

描述（由申请人提供）：亨廷顿病（HD）是一种致命的神经退行性疾病，由 HD 基因（HTT）外显子 1 中的三核苷酸重复序列（CAG）扩展引起。编码蛋白亨廷顿蛋白 (HTT) 中的谷氨酰胺扩增会产生有毒的功能增益，导致许多大脑区域的神经元退化，特别是纹状体。由于这些大脑区域涉及运动编程和认知的各个方面，HD 患者会出现许多症状，包括舞蹈症（四肢和颈部的不自主舞蹈样运动）、短期记忆丧失和情绪障碍（包括焦虑、抑郁）和侵略性。 RNA 干扰 (RNAi) 最近已成为通过降解编码 mRNA 来减少疾病基因表达的主要候选方法。虽然正常的亨廷顿蛋白在发育中起着至关重要的作用，但我们已经证明，HTT 表达的部分（60％）非等位基因特异性减少对于成年 HD 转基因小鼠来说具有良好的耐受性和治疗效果。在这里，我们建议在非人灵长类动物 (NHP) 中测试这种方法的效率、安全性和治疗益处，作为开发 RNAi 作为 HD 患者疗法的临床前步骤。我们首先旨在表征正常 NHP 大脑中针对 HTT mRNA 的非等位基因特异性 RNAi 的效率和安全性，作为原理验证。恒河猴 (n = 4) 将接受单侧立体定向注射到纹状体中的重组病毒载体，该载体表达 mi2.4 (rAAV-mi2.4)（一种 HTT 特异性 microRNA）。对侧半球将注射不会降低 HTT 表达的对照 miRNA (rAAV-miMIS)。动物将接受行为评估，以评估这种方法的功效和耐受性。注射后三个月，动物将被安乐死，并检查大脑的沉默效率和几种不同的安全性。接下来，我们的目标是建立一个 HD 的 NHP 模型，包括运动功能障碍、认​​知缺陷和情绪表现。恒河猴将接受纹状体注射病毒，该病毒表达具有 82 个 CAG 重复序列的突变 HTT (mHTT) 片段 (rAAV-mHTT82Q，n=4) 或仅具有 18 个重复序列的 mHTT 对照片段 (rAAV-mHTT-18Q， n=4）。该策略之前已被用来创建成功的 HD 啮齿动物模型。每月对动物进行各种运动、认知和心理测试评估。注射后六个月，动物将被安乐死，并分析它们的大脑是否有亨廷顿病病理学迹象。最后，我们的目标是测试 RNAi 在 HD 的 NHP 模型中的治疗效果。 NHP 将与 rAAV-mi2.4 (n=4) 或 rAAV-miMIS (n=4) 以及 rAAV-mHTT82Q 共同注射到纹状体中。每月将对动物进行各种运动、认知和心理分析评估。注射后 6 个月处死后，将对大脑进行分析，以预防 HD 相关病理。这些研究将共同​​评估 RNAi 在 NHP 大脑中的安全性和治疗效果。这里提出的研究，以及教学和应用培训，对于帮助我从博士后研究员过渡到独立研究者来说将是非常宝贵的。 公共健康相关性：拟议的一系列研究旨在测试 RNA 干扰作为亨廷顿病 (HD) 潜在疗法的益处。这种毁灭性的致命疾病无法治愈，目前仅在美国就有 30,000 人受到影响。在 HD 的非人类灵长类动物模型中测试 RNA 干扰的效用是其在临床中潜在应用的必要且关键的一步。