Development of an UNC13A antisense oligonucleotide treatment for ALS and FTD

UNC13A反义寡核苷酸治疗ALS和FTD的研究进展 项目摘要 背景：在97%的ALS病例和大约一半的FTD病例中，TAR DNA结合蛋白43(TDP-43)是 从细胞核流失到细胞质，在那里形成聚集体。TDP-43在细胞周期中的主要作用 在RNA剪接过程中，核是为了抑制隐蔽外显子(CE)的包涵体。最近的研究表明，行政长官是 当TDP-43从神经元的细胞核中耗尽时，包括在UN13A mRNA中，导致 UNC13A蛋白。UNC13A单核苷酸多态(SNPs)是相关的最强的命中 与肌萎缩侧索硬化症和FTD在人类GWAS研究中的应用。CE位于与主要风险相同的内含子区域 苏格兰民族党。SNP加剧UNC13A CE包涵体的风险-同时具有两个风险等位基因的ALS/FTD患者 有一个风险等位基因的患者比有一个风险等位基因的患者有更多的CE包含， 非风险等位基因。同样，风险SNP携带者的存活率也有剂量依赖性的降低。这种附加风险 强烈建议靶向UNC13A抑制CE包涵体可能有实质性的治疗作用 利益。由于几乎所有的ALS患者都有TDP-43病理，这样的治疗对他们有利，而不是 仅限于SNP携带者。UNC13A在突触传递中起关键作用，对突触是必不可少的 大多数兴奋性突触和神经肌肉接头的囊泡释放。在所有已知的基因中 由于TDP-43从细胞核中丢失，因此只有UNC13A具有如此强大的基因验证能力。更改后的 在TDP-43缺失的背景下，STMN2的表达是ALS/FTD的一个标志，但ALS之间没有联系 Risk和STMN2变种已经建立。因此，Ok13A靶向治疗应优先用于 快速进入临床概念验证研究。 AcuraStem的任务是确定拯救多种形式的肌萎缩侧索硬化症/功能性肌萎缩侧索硬化的目标。因此，我们有 建立了基因定义疾病和散发性疾病的特定患者ALS/FTD疾病模型。我们 在这些模型中显示，患有SNP风险的ALS患者的皮质神经元具有更多的UNC13A CE包涵体比来自ALS患者的神经元具有非危险等位基因。当我们耗尽TDP-43时 使用短干扰RNA(SiRNA)的患者来源的神经元它诱导了CES的强阳性包涵体，并减少了 在许多患者系列中，UNC13A的mRNA和蛋白水平正常。反义寡核苷酸(ASO)是 一种在中枢神经系统中寻找遗传靶点的有吸引力的方法，如UN13A，包括Nusinesen在内的几个成功案例 用于脊髓性肌萎缩症(SMA)和tofersen，很快将被批准用于SOD1-ALS。我们用我们的专有技术 ASO设计平台合成&gt；125 ASO并鉴定了几个新的ASO序列 阻断CE包涵体，恢复UNC13A的mRNA和蛋白水平。AcuraStem的独特定位是 有效的UNC13A ASO候选药物，可用于ALS和FTD的临床治疗。 目标和影响：这个直接到第二阶段的项目旨在优化这些候选者并确定真正的 在研究性新药(IND)毒性研究方面取得进展的开发候选者。这 该项目涉及与杰克逊实验室合作，以表征一种新的人类UC 13A TDP-43 ALS /ftd鼠标模型，这将是该领域必不可少的。这个项目很有可能在商业上获得成功 因为目前还缺乏治疗散发性肌萎缩侧索硬化症的治疗方法 和FTD人口，一个巨大的未得到满足的需求和商业机会。

Development of an UNC13A antisense oligonucleotide treatment for ALS and FTD Project Summary Background: In 97% of ALS cases, and roughly half of FTD cases, TAR DNA-binding protein 43 (TDP-43) is lost from the nucleus to the cytoplasm, where it forms into aggregates. A major function of TDP-43 in the nucleus is to repress cryptic exon (CE) inclusion during RNA splicing. Recent studies have shown that a CE is included in UNC13A mRNA when TDP-43 is depleted from the nucleus of neurons resulting in a loss of UNC13A protein. UNC13A single nucleotide polymorphisms (SNPs) are among the strongest hits associated with ALS and FTD in human GWAS studies. The CE is located in the same intronic region as the primary risk SNP. The risk SNP exacerbates the UNC13A CE inclusion - ALS / FTD patients with both risk alleles have more CE inclusion than patients with one risk allele, who have more CE inclusion than patients with the non-risk alleles. Similarly, risk SNP carriers have a dose-dependent reduction in survival. This additive risk strongly suggests that targeting UNC13A to suppress the CE inclusion could have a substantial therapeutic benefit. Since nearly all ALS patients have TDP-43 pathology, such a treatment would benefit them and not be limited to SNP carriers. UNC13A plays a critical role in synaptic transmission and is essential for synaptic vesicle release at most excitatory synapses and neuromuscular junctions. Among all the genes known to be dysregulated by the loss of TDP-43 from the nucleus, only UNC13A has such strong genetic validation. Altered STMN2 expression in the context of TDP-43 depletion is a hallmark of ALS / FTD, yet no link between ALS risk and STMN2 variants has been established. Thus, UNC13A targeting treatments should be prioritized for rapid advancement into clinical proof of concept studies. AcuraStem’s mission is to identify targets that rescue multiple forms of ALS / FTD. Thus we have established patient-specific ALS / FTD disease models of both genetically defined and sporadic diseases. We show in these models that cortical neurons derived from an ALS patient with the risk SNP have more UNC13A CE inclusion than neurons derived from ALS patients with non-risk alleles. When we depleted TDP-43 in patient-derived neurons using short interfering RNAs (siRNA) it induced a robust inclusion of CEs and reduced normal UNC13A mRNA and protein levels across many patient lines. Antisense oligonucleotides (ASOs) are an attractive approach for genetic targets in the CNS like UNC13A with several successes, including nusinersen for spinal muscular atrophy (SMA) and tofersen, soon to be approved for SOD1-ALS. We used our proprietary ASO design platform to synthesize >125 ASOs and identified several novel ASO sequences that potently blocked CE inclusion and restored UNC13A mRNA and protein levels. AcuraStem is uniquely positioned with potent UNC13A ASO candidates that can be advanced towards the clinic for ALS and FTD. Objectives & Impact: This Direct to Phase 2 project aims to optimize these candidates and identify a bona fide development candidate for advancement in investigational new drug (IND)-enabling toxicity studies. This project involves collaborating with the Jackson Laboratory to characterize a new human UNC13A TDP-43 ALS / FTD mouse model that will be essential for the field. This project has a high probability of commercial success because there is a dearth of disease-modifying treatments in development that could work for the sporadic ALS and FTD population, a large unmet need and commercial opportunity.