Reversal of Tau Pathology with MSUT2 siRNA Conjugates

使用 MSUT2 siRNA 缀合物逆转 Tau 病理学

• 批准号: 10240452
• 负责人: Brian C. Kraemer
• 金额: $ 9.99万
• 依托单位: DTX PHARMA, LLC
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2021-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10240452
• 关键词: Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease therapy; Amyloid beta-Protein; Animal Disease Models; Antibodies; Antisense Oligonucleotides; Biological; Brain Diseases; Caenorhabditis elegans; Cell Line; Cells; Clinic; Clinical Research; Clinical Trials; Data; Deposition; Development; Disease; Dose; Drug Delivery Systems; Drug Targeting; Evaluation; Failure; Fatty Acids; Frontotemporal Dementia; Funding; Gene Expression; Gene Proteins; Generations; Genes; Genetic; Goals; Health; Human; Impaired cognition; In Vitro; Knock-out; Knockout Mice; Knowledge; Lead; Lesion; Liver; Measurement; Measures; Mediating; Medical; Memory; Mus; Nerve Degeneration; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Pathologic; Pathology; Pathway interactions; Pharmaceutical Preparations; Pharmacology; Phase; Phase II Clinical Trials; Phenotype; Predisposition; Preventive measure; Problem Solving; Progressive Supranuclear Palsy; Rare Diseases; Resources; Risk; Safety; Small Business Innovation Research Grant; Small Interfering RNA; Tauopathies; Technology; Testing; Therapeutic; Therapeutic Trials; Time; Tissues; Toxic effect; Transgenic Animals; Validation; Wild Type Mouse; Work; brain tissue; cost; design; drug discovery; experimental study; genetic approach; improved; in vivo; inflammatory marker; interest; knock-down; lead candidate; mRNA Expression; mindfulness; mouse model; neuroinflammation; neuron loss; novel; novel strategies; novel therapeutic intervention; novel therapeutics; overexpression; prevent; programs; protein expression; screening; siRNA delivery; spatial memory; targeted agent; tau Proteins; tau aggregation; tau mutation; tau-1; therapeutic evaluation; therapeutic target; uptake

Project Summary Genetic and pathologic evidence in 'pure' tauopathies such as Progressive Supranuclear Palsy (PSP), Corticobasilar Degeneration (CBD) and some cases of Fronto-temporal Dementia (FTD) directly implicate tau as causing neuronal cell death, while in Alzheimer’s Disease (AD) tau accumulation correlates with development and progression of cognitive impairment. Because of failure (to date) of drugs targeting amyloid beta, tau has now emerged as 'the next best' therapeutic target in the search for disease modifying drugs. There are currently 2 active phase 2 clinical studies using anti-tau antibodies in both AD and PSP underway, with additional tau targeting agents under development. Here, we propose a novel, alternative strategy to ameliorate neuronal tau toxicity by targeting MSUT2 gene expression. The body of knowledge supporting this approach includes amelioration of tau toxicity in vivo when MSUT2 is knocked out in transgenic animals expressing a pathologic tau species and in vitro where siRNA's that knock down MSUT2 are cytoprotective. Effective in vivo delivery of siRNA conjugates that lower MSUT2 levels will provide a distinct means of intervening against tauopathy with the advantage of having a viable pathway forward for development of a human therapeutic. We hypothesize that siRNA-mediated reduction of MSUT2 levels will protect against and potentially reverse in vivo neurodegeneration driven by tau accumulation. DTx Pharma has created a novel, proprietary fatty acid motif that delivers siRNA in vivo into multiple cells/tissues, including CNS neurons, allowing efficient target gene knockdown. Here we outline the initial steps of a collaborative drug discovery program with Brian Kraemer that uses the DTx motif to deliver MSUT2 specific siRNA to neurons in vivo to test whether knockdown of MSUT2 is neuro-protective in a well-characterized mouse model of tau-mediated degeneration. If successful, this approach would be advanced to generate lead, fatty acid-modified, MSUT2 siRNAs for potential therapeutic application in tauopathies. We propose 3 specific aims: SA1, generation and screening of MSUT2 siRNAs for gene knockdown activity in MSUT2 expressing cells. Conjugation of the most active siRNAs to the DTx fatty acid motif for evaluation of knockdown efficiency in cell lines and primary neurons. SA2, in vivo experiments to optimize dosing, evaluate duration of activity and assess for potential toxicities of DTx-conjugated MSUT2 siRNAs in wildtype mice. SA3, a potent, safe and efficacious siRNA identified in SA2 will be used to treat mutant tau expressing mice (PS19) in a therapeutic trial. Analyses will include the measurement of memory function, accumulation of phosphorylated tau, deposition of aggregated/oligomeric tau, neuroinflammation, and neurofibrillary degeneration. We will compare the effect of siRNA mediated MSUT2 knockdown on tau pathology with prior results in the same mouse model using anti-tau antibodies (C2N/Abbvie) and tau-targeted antisense oligonucleotides (Ionis/Biogen) that supported advancement of novel therapeutics that are currently in phase 2 clinical trials. If we have similar or better activity—we will seek to advance a lead MSUT2 targeted siRNA.

项目概要 “纯”tau蛋白病的遗传和病理证据，例如进行性核上性麻痹 (PSP)、 皮质基底节变性 (CBD) 和一些额颞叶痴呆 (FTD) 病例直接涉及 tau tau 蛋白会导致神经细胞死亡，而在阿尔茨海默病 (AD) 中，tau 蛋白的积累与发育相关 和认知障碍的进展。由于（迄今为止）针对 β 淀粉样蛋白的药物失败，tau 蛋白已 现在成为寻找疾病修饰药物中的“下一个最佳”治疗靶标。目前有 正在进行 2 项使用抗 tau 抗体治疗 AD 和 PSP 的 2 期临床研究，另外还有其他 tau 抗体 正在开发的靶向药物。在这里，我们提出了一种新颖的替代策略来改善神经元 tau 蛋白 通过靶向 MSUT2 基因表达来产生毒性。支持这种方法的知识体系包括 当 MSUT2 在表达病理学的转基因动物中被敲除时，体内 tau 毒性的改善 tau 物种和体外，敲低 MSUT2 的 siRNA 具有细胞保护作用。有效的体内递送 降低 MSUT2 水平的 siRNA 结合物将提供一种独特的干预 tau 蛋白病的方法 具有开发人类治疗方法的可行途径的优势。我们假设 siRNA 介导的 MSUT2 水平降低将在体内预防并可能逆转 tau 积累驱动的神经退行性变。 DTx Pharma 创造了一种新颖的专有脂肪酸基序 将 siRNA 体内递送至多个细胞/组织，包括 CNS 神经元，从而实现有效的靶基因 击倒。在这里，我们概述了与 Brian Kraemer 合作药物发现计划的初始步骤 使用 DTx 基序将 MSUT2 特异性 siRNA 递送至体内神经元，以测试 MSUT2 的敲低是否有效 在 tau 介导的变性小鼠模型中具有神经保护作用。如果成功的话，这个方法 将进一步产生脂肪酸修饰的先导 MSUT2 siRNA，用于潜在的治疗应用 tau蛋白病。我们提出了 3 个具体目标：SA1、用于基因敲除的 MSUT2 siRNA 的生成和筛选 MSUT2 表达细胞中的活性。将最活跃的 siRNA 与 DTx 脂肪酸基序缀合 评估细胞系和原代神经元的敲低效率。 SA2，体内实验优化 剂量、评估活性持续时间并评估 DTx 缀合的 MSUT2 siRNA 的潜在毒性 野生型小鼠。 SA3是SA2中鉴定出的一种强效、安全且有效的siRNA，将用于治疗突变tau蛋白 在治疗试验中表达小鼠（PS19）。分析将包括记忆功能的测量， 磷酸化 tau 蛋白的积累、聚集/寡聚 tau 蛋白的沉积、神经炎症和 神经原纤维变性。我们将比较 siRNA 介导的 MSUT2 敲低对 tau 病理学的影响 使用抗 tau 抗体 (C2N/Abbvie) 和 tau 靶向反义抗体在同一小鼠模型中获得先前结果 支持目前处于第 2 阶段的新型疗法进展的寡核苷酸（Ionis/Biogen） 临床试验。如果我们有类似或更好的活性，我们将寻求推进领先的 MSUT2 靶向 siRNA。