Reversal of Tau Pathology with MSUT2 siRNA Conjugates

使用 MSUT2 siRNA 缀合物逆转 Tau 病理学

• 批准号: 9909831
• 负责人: Brian C. Kraemer
• 金额: $ 21.3万
• 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/9909831
• 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.

项目摘要 诸如进行性次脑性麻痹（PSP）等“纯”呼吸病中的遗传和病理证据， 皮质碱性变性（CBD）和某些额叶痴呆（FTD）的病例直接暗示tau 由于引起神经元细胞死亡，而在阿尔茨海默氏病（AD）tau积累与发育相关 和认知障碍的进展。由于靶向淀粉样蛋白β的药物的失败（迄今为止），tau具有 现在，在寻找修饰疾病的药物中，成为“下一个最佳”热目标。目前有 2在进行AD和PSP中使用抗TAU抗体的2个活性阶段2临床研究，还有其他TAU 正在开发的目标代理。在这里，我们提出了一种新颖的替代策略，以改善神经元tau 通过靶向MSUT2基因表达来毒性。支持这种方法的知识体系包括 当在表达病理学的转基因动物中敲出MSUT2时，体内Tau毒性的改善 tau物种和在体外敲低MSUT2的siRNA具有细胞保护作用。有效的体内输送 siRNA结合，较低的MSUT2水平将提供一种与Tauopathy进行干预的不同方法 在发展人类治疗方面具有可行的途径的优势。我们假设 siRNA介导的MSUT2水平的降低将防止并有可能在体内逆转 由tau积累驱动的神经变性。 DTX Pharma创建了一种新颖的专有脂肪酸基序 这将体内的siRNA输送到包括CNS神经元在内的多个细胞/组织中，允许有效的靶基因 击倒。在这里，我们概述了与布莱恩·克雷默（Brian Kraemer）合作的药物发现计划的初始步骤 使用DTX图案将MSUT2特异性siRNA传递到体内神经元，以测试MSUT2的敲低是否为 在tau介导的变性的良好特征小鼠模型中神经保护。如果成功，这种方法 将要进行铅，脂肪酸改性，MSUT2 siRNA，以用于潜在的治疗应用 tauopathies。我们提出了3个特定目标：SA1，MSUT2 siRNA的生成和筛选，用于基因敲低 MSUT2表达细胞的活性。最活跃的siRNA与DTX脂肪酸基序结合 评估细胞系和原发性神经元中敲低效率。 SA2，体内实验以优化 剂量，评估活动的持续时间和评估DTX偶联的MSUT2 siRNA的潜在战术 野生型小鼠。 SA3，在SA2中鉴定出的潜在，安全有效的siRNA将用于治疗突变体tau 在治疗试验中表达小鼠（PS19）。分析将包括记忆函数的测量， 磷酸化tau的积累，聚集/寡聚tau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病理的影响 使用抗TAU抗体（C2N/ABBVIE）和Tau靶向反义的相同小鼠模型的先前结果 寡核苷酸（Ionis/Biogen）支持了新疗法的进步，目前处于第2阶段 临床试验。如果我们有相似或更好的活动 - 我们将寻求推进铅MSUT2靶向siRNA。