In vivo modelling and therapy development for stathmin-2 loss in TDP-43 proteinopathies

项目总结 TDP-43蛋白病代表了一组以RNA-43重新定位为特征的神经系统疾病。 结合蛋白TDP-43从其天然核室到细胞质，在那里它积聚成 集合体。在超过95%的肌萎缩侧索硬化症(ALS)患者中发现了TDP-43病理， 大约一半的额颞叶痴呆(FTD)患者和超过30%的阿尔茨海默病患者。 TDP-43参与基本的RNA加工活动，并结合数千个转录本来调节其 表达、剪接和运输。我们和其他人最近确定了TDP-43在调节 参与轴突的微管蛋白结合蛋白神经元生长相关因子Stathmin-2的表达 生长和再生。TDP-43中断导致截断(通过异常剪接和过早 多聚腺苷酸化)，从而在TDP-43核水平下降时沉默stathmin-2。 在绝大多数ALS/FTD患者的受影响神经元中，stathmin-2受到抑制，神经元 TDP-43缺失的IPSC来源运动神经元的再生能力可通过提高水平来挽救 STMN2.值得注意的是，虽然stathmin-2是受TDP-43减少影响最大的人mRNA，但stahmin-2 在啮齿动物中，前-mRNA既不受TDP-43的结合，也不受TDP-43的调节，这是TDP-43动物模型的主要警告 蛋白质病。在这里，我们建议使用新生成的小鼠模型来确定灭活(Aim 1)或人源化的stathmin-2(Aim 2)等位基因与TDP-43、原颗粒蛋白或C9ORF72 ALS/FTD协同作用 突变以驱动运动神经元或认知疾病。虽然有证据支持stathmin-2对 轴突再生，Stathmin-2缺失在神经退行性变中的作用仍有待确定。我们 提出一项雄心勃勃的计划，以确定体内stathmin-2减少对TDP-43蛋白病变的影响。 在这个项目中产生的小鼠模型将概括与TDP-43相关的主要分子改变 蛋白质病，是ALS/FTD治疗发展的重要平台。此外, 认识到恢复stathmin-2水平是一项有吸引力的战略，在#年具有广泛影响 神经退行性疾病，我们将测试反义寡核苷酸(ASO)的治疗潜力 防止Stmn2的异常剪接(目标3)。这一合作努力有可能发现以下方面的新见解 Stathmin-2缺失在神经退行性变中的作用，产生新的临床前模型，并发展一种 ALS和FTD的新治疗策略。

PROJECT SUMMARY TDP-43 proteinopathies represent a set of neurological disorders characterized by relocalization of the RNA- binding protein TDP-43 from its native nuclear compartment to the cytoplasm where it accumulates into aggregates. TDP-43 pathology is found in more than 95% of patients with amyotrophic lateral sclerosis (ALS), approximately half of frontotemporal dementia (FTD) cases, and more than 30% of Alzheimer’s disease patients. TDP-43 is involved in fundamental RNA processing activities and binds thousands of transcripts to regulate their expression, splicing and transport. We and others have recently identified a critical role for TDP-43 in regulating the expression of the neuronal growth-associated factor stathmin-2, a tubulin-binding protein involved in axon outgrowth and regeneration. TDP-43 disruption induces truncation (by aberrant splicing and premature polyadenylation) of stathmin-2 pre-mRNA, thereby silencing stathmin-2 when TDP-43 nuclear levels fall. Stathmin-2 is suppressed in affected neurons from the vast majority of ALS/FTD patients, and the neuronal regeneration capacity of iPSC-derived motor neurons with TDP-43 depletion can be rescued by increasing levels of STMN2. Notably, while stathmin-2 is the human mRNA most affected by reduction in TDP-43, the stahmin-2 pre-mRNA is neither bound nor regulated by TDP-43 in rodents, a major caveat for animal modeling of TDP-43 proteinopathies. Here we propose to use newly generated mouse models to determine whether inactivated (Aim 1) or humanized stathmin-2 (Aim 2) alleles synergize with TDP-43, progranulin, or C9ORF72 ALS/FTD mutations to drive motor neuron or cognitive disease. While evidence supports that stathmin-2 is essential for axonal regeneration, the contribution of stathmin-2 loss in neurodegeneration remains to be determined. We propose an ambitious program to establish the impact of in vivo stathmin-2 reduction in TDP-43 proteinopathies. Mouse models generated in this project will recapitulate a major molecular alteration associated with TDP-43 proteinopathy and represent an important platform for therapeutic development in ALS/FTD. In addition, recognizing that restoration of stathmin-2 level is an attractive strategy with broad implications in neurodegenerative diseases, we will test the therapeutic potential of antisense oligonucleotides (ASO) that prevent aberrant splicing of Stmn2 (Aim 3). This collaborative effort has the potential to uncover new insights on the contribution of stathmin-2 loss in neurodegeneration, to generate new preclinical models, and to develop a novel therapeutic strategy for ALS and FTD.