Targeting STAU1 for TDP-43 proteinopathies

项目摘要/摘要 我们的U01创建拨款支持的BIIB105的开发，一种ATXN2反义寡核苷酸(ASO)，用于 目前正在进行肌萎缩侧索硬化症(ALS)的1期试验。我们现在提议扩大 通过将ASOS开发为STAU1来实现ATXN_2目标空间。STAU1与ATXN2相互作用，并在 多种神经退行性变的体外和体内模型。我们的概念验证数据显示PD为正 疗效，因为降低STAU1可以改变疾病相关的表型。ATXN2型[Q127]sca2小鼠 单倍体不足的Stau1使小脑基因和自噬蛋白丰度正常化，ATXN2蛋白 聚集体被消除，运动行为得到改善。此外，异常缓慢的内在 经Stau1 ASO治疗后，SCA2小鼠的浦肯野细胞(PC)放电频率恢复。STAU1扩展了 ATXN2靶区，可能被证明是ALS和其他TDP-43的更有效的治疗靶点 蛋白质病，其蛋白质丰度在多个体外和体内神经退行性变中增加3-4倍 模型包括散发性ALS脊髓。我们已经筛选了针对STAU1的ASO，确定 10个TOP可将SCA2患者成纤维细胞中STAU1的表达降低90-99%，其中包括两个有效的ASO 这也针对小鼠Stau1，对于疾病模型的体内疗效研究来说是非常宝贵的。我们的总体目标是 优化ASO序列和化学成分以降低STAU1的表达，并完善体内疗效模型 用于表征体内的靶点接合和PD/PK参数。目前，还没有治疗方法存在 显著改变散发性肌萎缩侧索硬化。STAU1在多种神经退行性疾病模型中过多， 通过基因相互作用的Stau1基因敲除改善了体内的表型。我们研究的R61阶段将跨越一个 目标1将为以下目标准备序列优化的化学修饰ASO BAC-STAU1小鼠和PRP-TDP43Q331K小鼠的药效试验。AIM 2改进了PRP-TDP43Q331K小鼠的用途 用于表征STAU1 ASO的有效性，从而得出有效敲除STAU1所需的最佳剂量 和表型修饰。R33阶段跨越研究的剩余两年，包括 另外两个目标：目标3将证明Asos铅改变了TDP-43的丰度和溶解度，使之正常化 PRP-TDP43Q331K的自噬标记、组织表型、运动神经元计数和运动行为 老鼠。目标4将使用PRP确定ASO对提高三种最有效的铅ASO的存活率的效果。 TDP43WTxQ331K双转基因小鼠。这项研究的最终里程碑将是体内疗效的验证 对于三个优化的ASO，对于Staufen击倒具有较长的作用时间，并且对于额外的 ASO序列对今后的研究有帮助。关键的目标是鉴定铅STAU1 ASO 修改适合进展为紧急或蓝图的ALS神经退行性表型 神经治疗网络(BPN)在美国国立卫生研究院的应用。最终，我们的研究将显著扩展 肌萎缩侧索硬化症和其他神经退行性疾病的治疗目标。

Project Summary/Abstract Our U01 CREATE grant supported development of BIIB105, an ATXN2 antisense oligonucleotide (ASO) for treatment that is now in a phase 1 trial for amyotrophic lateral sclerosis (ALS). We are now proposing to expand the ATXN2 target space by developing ASOs to STAU1. STAU1 interacts with ATXN2, and is overabundant in multiple in vitro and in vivo models of neurodegeneration. Our proof-of-concept data showed positive PD efficacy, in that lowering STAU1 modifies disease-related phenotypes. ATXN2[Q127] SCA2 mice haploinsufficient for Stau1 had normalized cerebellar gene and autophagy protein abundances, ATXN2 protein aggregates were eliminated, and motor behavior was improved. In addition, the abnormally slow intrinsic Purkinje cell (PC) firing frequency in SCA2 mice is restored following Stau1 ASO treatment. STAU1 expands the ATXN2 target space and may prove more effective as a therapeutic target for ALS and other TDP-43 proteinopathies as its protein abundance is increased 3-4 fold in multiple in vitro and in vivo neurodegenerative models including sporadic ALS spinal cord. We have already screened for ASOs targeting STAU1, identifying 10 top leads that lower STAU1 expression by 90-99% in SCA2 patient fibroblasts, including two potent ASOs that also target mouse Stau1 invaluable for in vivo efficacy studies in disease models. Our overall objective is to optimize ASO sequence and chemistry for lowering STAU1 expression, and to refine an in vivo efficacy models for characterizing target engagement and PD/PK parameters in vivo. Currently, no therapeutics exist that significantly modify sporadic ALS. STAU1 is overabundant in multiple neurodegenerative disease models, and Stau1 knockdown by genetic interaction improves in vivo phenotypes. The R61 phase of our study will span one year and is organized in two aims: Aim 1 will prepare sequence optimized chemically-modified ASOs for efficacy testing in BAC-STAU1 mice and Prp-TDP43Q331K mice. Aim 2 refines the use of Prp-TDP43Q331K mice for characterizing efficacy of STAU1 ASO, resulting in optimal doses required for effective STAU1 knockdown and phenotype modification. The R33 phase spans the remaining two years of the study and is comprised of two additional aims: Aim 3 will demonstrate that lead ASOs modify TDP-43 abundance & solubility, normalizes autophagy markers, histological phenotypes and motor neuron counts and motor behavior of Prp-TDP43Q331K mice. Aim 4 will determine ASO effects for improving survival for three most efficacious lead ASOs using Prp- TDP43WTxQ331K double transgenic mice. The terminal milestone for this study will be validation of in vivo efficacy for three optimized ASOs with long duration of action for Staufen knockdown, and efficacy data for additional ASO sequences useful or future investigation. The crucial objective is the identification of lead STAU1 ASOs that modify an ALS neurodegenerative phenotype suitable for advancing to a URGenT or Blueprint Neurotherapeutics Network (BPN) application to the NIH. Ultimately, our study will significantly expand therapeutic targets for ALS and other neurodegenerative diseases.