Atypical TDP43 isoforrms driving neurodegeneration in FTD/ALS

非典型 TDP43 亚型导致 FTD/ALS 神经退行性变

基本信息

批准号：
10295762
负责人：
Sami Barmada
金额：
$ 39万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-12-01 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10295762
关键词：
ALS patients Address Affect Alternative Splicing Amino Acids Amyotrophic Lateral Sclerosis Antibodies Automobile Driving Autopsy Binding Brain C9ORF72 CRISPR/Cas technology Cell Death Cell Nucleus Characteristics Clinical Cultured Cells Data Deposition Disease Disease model Exclusion Frontotemporal Dementia Generations Genome engineering Goals Homeostasis Human Hyperactivity In Vitro Induced Mutation Induced pluripotent stem cell derived neurons Label Length Link Michigan Modeling Mutation Nerve Degeneration Neurons Nuclear Nuclear Export Nuclear Protein Pathogenesis Pathologic Pathology Pathway interactions Patients Play Prevalence Production Protein Isoforms Proteins RNA RNA Splicing RNA-Binding Proteins Reagent Reporter Rodent Specificity Stress Testing Therapeutic Time Tissues Toxic effect Transcript Universities cohort design frontotemporal lobar dementia-amyotrophic lateral sclerosis in vivo induced pluripotent stem cell locked nucleic acid mutant neuron loss neuroprotection novel novel therapeutics overexpression prevent protein TDP-43 stress granule stressor targeted treatment therapeutically effective therapy development

项目摘要

Cytosolic mislocalization of the RNA binding protein TDP43 and neuronal hyperexcitability are cardinal features of TDP43-related frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Nuclear exclusion and cytosolic deposition of TDP43 are found in over half of those with FTD, and nearly 95% of those with ALS, but the origin of these changes remains unknown. Likewise, neuronal hyperexcitability is a ubiquitous finding in FTD/ALS patients, in vivo and in vitro disease models, yet the cause and consequences of this phenomenon are unclear. Our preliminary data show for the first time an intrinsic connection between TDP43 deposition and neuronal hyperexcitabilty that may play a pivotal part in the neurodegeneration observed in TDP43-related FTD/ALS. Elevated neuronal activity upregulates an uncommon TDP43 isoform that lacks the canonical, low-complexity carboxy-terminus of the protein. Due to its active nuclear export and its ability to bind full-length (fl)TDP43, This shortened (s)TDP43 isoform is actively exported from the nucleus, accumulates in cytosolic aggregates, and sequestrates full-length (fl)TDP43, thereby recapitulating TDP43 pathology in FTD/ALS. Our central goal with this project is to determine the impact of sTDP43 in FTD/ALS pathogenesis, with a long-term objective of defining novel and effective therapeutic strategies targeting TDP43 homeostasis. We will test the hypothesis that sTDP43 drives neurodegeneration in TDP43-related FTD/ALS by three specific aims. First, we will take advantage of an sTDP43-specific antibody that we developed to determine the prevalence and distribution of sTDP43 accumulation in a large cohort of sporadic and familial FTD/ALS cases curated by the University of Michigan Brain Bank. We will also investigate the impact of sTDP43 on RNA homeostasis, and determine the relationship between sTDP43, stress, and stress granules in disease models. Lastly, we will assess the contribution of sTDP43 to neurodegeneration in rodent primary neurons and human induced pluripotent stem cell-derived neurons from patients carrying FTD/ALS-associated C9orf72 hexanucleotide expansion mutations. At the completion of these studies, we will have delineated a unique disease mechanism leading to neurodegeneration in TDP43-related FTD/ALS, and highlighted potential therapeutic approaches focusing on the abnormal activity-dependent production of toxic TDP43 isoforms.

RNA结合蛋白TDP43和神经元过度兴奋性的胞质错误定位是基本的 TDP43相关的额颞痴呆（FTD）和肌萎缩性侧索硬化症（ALS）的特征。核 TDP43的排除和胞质沉积在有FTD的一半以上，其中近95％使用ALS，但是这些变化的起源仍然未知。同样，神经元过度兴奋性是在FTD/ALS患者，体内和体外疾病模型中无处不在的发现，但是这种现象尚不清楚。我们的初步数据首次显示 TDP43沉积和神经元过度舒适，可能在神经变性中发挥关键作用在TDP43相关的FTD/ALS中观察到。升高的神经元活性上调了不常见的TDP43同工型缺乏蛋白质的规范，低复杂的羧基末端。由于其主动核出口及其能够结合全长（FL）TDP43的能力，该缩短（S）TDP43同工型被积极从细胞核中导出，积聚在胞质聚集体中，并螯合全长（FL）TDP43，从而概括TDP43 FTD/ALS中的病理学。该项目的核心目标是确定STDP43在FTD/ALS中的影响发病机理，具有定义针对TDP43的新颖有效的治疗策略的长期目标稳态。我们将测试STDP43通过TDP43相关FTD/ALS的神经变性的假设三个具体目标。首先，我们将利用我们开发的STDP43特异性抗体确定在零星和家族的大量队列中STDP43积累的患病率和分布密歇根大学大脑银行策划的FTD/ALS病例。我们还将调查在RNA稳态上的STDP43，并确定STDP43，应力颗粒和应力颗粒之间的关系疾病模型。最后，我们将评估STDP43对啮齿动物原发性神经退行性的贡献神经元和人类诱导的多能干细胞衍生的神经元，来自携带FTD/ALS相关的患者 C9ORF72六核苷酸膨胀突变。这些研究完成后，我们将描述独特的疾病机制导致与TDP43相关的FTD/ALS的神经变性，并强调了潜力治疗方法着重于毒性TDP43同工型的活性异常的产生。