Project 4: Therapeutic Gene Editing for Rett Syndrome

项目 4：雷特综合征的治疗性基因编辑

• 批准号: 10668770
• 负责人: Cathleen M Lutz
• 金额: $ 46.97万
• 依托单位: JACKSON LABORATORY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-16 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10668770
• 关键词: Adopted; Affect; Age; Age Years; Animals; Behavior Therapy; Biological Models; Birth; Breathing; Cell model; Cells; Characteristics; Clinical Trials; DNA Sequence Alteration; Deceleration; Disease; Disease Progression; Dose; Engineering; Event; Exons; FDA approved; Female; Fibroblasts; Gait abnormality; Genes; Grant; Growth; Hand; Head; Histologic; Human; In Vitro; Incidence; Language; Life Expectancy; Link; Measurement; Methods; Methyl-CpG-Binding Protein 2; Missense Mutation; Modeling; Movement; Mus; Mutation; Nature; Neonatal; Neurodevelopmental Disorder; Neurologic Deficit; Nonsense Mutation; Outcome; Patients; Pharmaceutical Preparations; Preparation; Proteins; Rett Syndrome; Safety; Seizures; Sleep disturbances; Speech; Stereotyping; Technology; Testing; Therapeutic; Titrations; Twin Multiple Birth; Variant; Viral; Work; X Chromosome; base; base editing; design; dosage; effectiveness testing; efficacy evaluation; efficacy study; genome editing; in vivo; male; mouse model; nervous system disorder; overexpression; pre-IND studies; pre-clinical; prime editing; pup; safety assessment; skills; small molecule; success; therapeutic gene; timeline; tool

PROJECT SUMMARY PROJECT 4 (Rett) Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutations in the gene MECP2. The majority of RTT is caused by the same d eight reoccurring mutations in mutational hotspots of the 3rd and 4th exons. These four missense mutations and four nonsense mutations (R106W, R133C, T158M, R168X, R255X, R270X, R294X, and R306C) make up 70% of all Rett cases. RTT predominantly affects females, occurring at an incidence of 1-10,000 live female births and presents as a regression in milestones between the ages of 6-18 months. Hallmark characteristics of Rett include progressive loss of purposeful hand skills, speech and language regression, gait abnormalities, and stereotypic hand movements. Other features of the disorder include decelerated head growth, sleep disturbances, breathing abnormalities, and a high incidence of seizures. The life expectancy for patients with Rett is typically around 40-50 years of age. Landmark studies using conditional mouse models of Mecp2 to turn on the endogenous Mecp2 mouse gene post-symptomatically have convincingly demonstrated that neurological deficits associated with loss of Mecp2 is reversible to a significant degree. To date, clinical trials have focused on small molecules that modulate mechanisms downstream of MECP2. With more the 25+ such trials, limited success has been demonstrated with only modest behavior modifications and no approved FDA drugs for RTT. Gene and protein replacement strategies have been stymied with regards to controlled dosage affects that require precise titration of MECP2, as overexpression of Mecp2 in cells is toxic and are further confounded by the X-linked nature of the disease with cell to cell variation of MECP2 expression resulting from chromosome X-linked inactivation. For these reasons, base editing strategies that directly correct the endogenous genetic mutation and restore MECP2 to endogenous cellular levels are an extremely attractive therapeutic strategy for RTT. In this follower project, we aim to correct missense and nonsense mutations to enable rescue of disease progression in Rett patients. Specifically, we aim to: (1) Design, test and optimize Base Editing, Prime editing and Twin Editing strategies for 5 different mutations; (2) Test these strategies in mouse models containing humanized exons with engineered missense and nonsense mutations. (3) Perform pre-clinical IND enabling studies to assess safety and efficacy. We will work closely with the Gene Editing Core to develop the latest base editing and/or prime editing technologies in RTT model systems. We will iterate with the Gene Editing Core to ensure that our genome editing tools maximize on-target editing efficiencies, minimize undesirable gene editing byproducts and off-target editing events, and maximize compatibility with in vivo delivery methods of potential therapeutic relevance.

项目摘要项目4（RETT） RETT综合征（RTT）是由基因MECP2突变引起的X连锁神经发育障碍。 大多数RTT是由相同的D八个重复发生的突变引起的 第四外显子。这四个错义突变和四个废话突变（R106W，R133C，T158M，R168X，R168X， R255X，R270X，R294X和R306C）占所有RETT案例的70％。 RTT主要影响女性， 发生在1-10,000个活着的女性出生的发生率，并作为在 年龄为6-18个月。 RETT的标志性特征包括逐步丧失有目的的手技能，语音 语言回归，步态异常和刻板印象的手动运动。疾病的其他特征 包括减速的头部生长，睡眠障碍，呼吸异常以及癫痫发作的高发病率。 RETT患者的预期寿命通常约为40-50岁。地标研究使用 MECP2的有条件小鼠模型在遭到杀伤性的内源性MECP2小鼠基因上已有 令人信服地表明，与MECP2丢失相关的神经缺陷对重要的 程度。迄今为止，临床试验集中在调节下游机制的小分子上 MECP2。有了更多的25多个此类试验，仅以适度的行为证明了有限的成功 修改和未经批准的RTT FDA药物。基因和蛋白质替代策略已被阻碍 关于需要精确滴定MECP2的受控剂量影响MECP2的过表达 细胞是有毒的，并被疾病的X连锁性与MECP2细胞变异的X连锁性混淆 染色体X连接失活而产生的表达。由于这些原因，基础编辑策略 直接纠正内源性基因突变并将MECP2恢复为内源性细胞水平是 RTT极具吸引力的治疗策略。 在这个追随者项目中，我们旨在纠正错义和胡说八道突变以拯救疾病 RETT患者的进展。具体来说，我们的目标是：（1）设计，测试和优化基础编辑，主要编辑 以及针对5种不同突变的双编辑策略； （2）在包含的鼠标模型中测试这些策略 人源化外显子具有工程性的错义和胡说八道突变。 （3）执行临床前启用 评估安全性和功效的研究。我们将与基因编辑核心紧密合作，以开发最新的基础 RTT模型系统中的编辑和/或主要编辑技术。我们将用基因编辑核心迭代 确保我们的基因组编辑工具最大化目标编辑效率，最大程度地减少不良基因编辑 副产品和非目标编辑事件，并最大程度地与体内输送方法兼容 治疗意义。