SMN dysfunction in FUS-dependent ALS

FUS 依赖性 ALS 中的 SMN 功能障碍

• 批准号: 9329512
• 负责人: Livio Pellizzoni
• 金额: $ 20万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9329512
• 关键词: Address; Adolescent; Adult; Age; Alleles; Amyotrophic Lateral Sclerosis; Anabolism; Animal Model; Biogenesis; Biological Assay; Biological Models; Biology; Birth; Cell model; Cessation of life; Child; Code; Complex; Defect; Denervation; Disease; Disease Pathway; ES Cell Line; Etiology; Evaluation; Event; Familial Amyotrophic Lateral Sclerosis; Fibroblasts; Foundations; Functional disorder; Gene Delivery; Genes; Genetic; Genotype; Histones; Human; In Vitro; Induced Mutation; Infant Mortality; Injection of therapeutic agent; Knowledge; Lasers; Link; Mammalian Cell; Mediating; Mendelian disorder; Messenger RNA; Microdissection; Minority; Modeling; Molecular; Monitor; Morphology; Motor; Motor Neuron Disease; Motor Neurons; Mus; Mutant Strains Mice; Mutation; Nature; Nerve Degeneration; Nervous system structure; Nuclear; Pathogenesis; Pathogenicity; Pathology; Pathway interactions; Patients; Phenotype; Property; Protein Isoforms; RNA; RNA Processing; RNA Splicing; RNA-Binding Proteins; Risk; Role; SMN protein (spinal muscular atrophy); SMN1 gene; Series; Severity of illness; Small Nuclear RNA; Small Nuclear Ribonucleoproteins; Solid; Spinal; Spinal Cord; Spinal Muscular Atrophy; Testing; Toxic effect; Transgenic Mice; Work; behavior test; clinical phenotype; defined contribution; design; experimental study; gain of function; gene product; human disease; interdisciplinary approach; mRNA Precursor; motor disorder; motor neuron degeneration; motor neuron function; mouse model; mutant; nervous system disorder; neuromuscular; novel; overexpression; sarcoma; skeletal muscle wasting; survival motor neuron gene; therapeutic target

Amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) are fatal neurological disorders that involve the selective degeneration of spinal motor neurons. SMA – the most common genetic cause of infant mortality – is a monogenic disorder caused by widespread deficiency in the survival motor neuron (SMN) protein due to deletion of the SMN1 gene. In contrast, ALS is predominantly a sporadic disorder, but in a minority of familial cases, mutations in over 20 different genes cause motor neuron degeneration. Genetic and molecular studies increasingly suggest that ALS and SMA may share common underlying mechanisms of disease. This project focuses on one form of familial ALS caused by mutations in the RNA binding protein fused in sarcoma (FUS) - which are associated with a broad range of clinical phenotypes including some of the most aggressive, juvenile-onset forms of the disease - and the possible role of SMN biology in the pathogenesis of FUS-dependent motor neuron degeneration. SMN has a well-established function in the assembly of small nuclear ribonucleoproteins (snRNPs) involved in diverse mRNA processing pathways and increasing evidence links SMN-dependent RNA dysregulation with the etiology of SMA. Remarkably, recent studies in cultured mammalian cells and ALS patients' fibroblasts have shown that FUS depletion or expression of ALS-linked FUS mutations disrupt the normal localization of SMN to nuclear bodies known as Gems. Furthermore, FUS has been shown to associate with SMN as well as specific snRNPs whose biogenesis is SMN-dependent and might be disrupted by ALS-linked FUS mutations. Together, these findings suggest that FUS and SMN are functionally linked through a shared molecular pathway(s) and support the view that SMA and ALS are related motor neuron diseases. However, the normal requirement of FUS for snRNP biogenesis and the pathogenic impact of FUS mutations on SMN biology have not yet been defined mechanistically, and the contribution of SMN dysfunction to FUS-ALS pathology remains unknown. To address these outstanding questions directly, our project takes a systematic, multi-disciplinary approach involving novel mouse models of FUS-dependent ALS to explore potential SMN-dependent mechanisms of FUS-mediated motor neuron degeneration. In Aim 1, we will investigate the phenotypic effects of both reduced and increased SMN expression on FUS-dependent motor neuron pathology in mouse models of ALS. In Aim2, we will employ a comprehensive set of molecular approaches to establish the functional relevance of normal and pathogenic FUS-SMN interactions in the pathway(s) of snRNP biogenesis in motor neurons using a combination of cellular and animal model systems. Collectively, these studies aim to establish convergent mechanisms in ALS and SMA and will yield a more complete understanding of the biology of FUS and SMN that is relevant to motor neuron survival. Identification of shared molecular pathways contributing to death and dysfunction of motor neurons in SMA and ALS may also expand the range of therapeutic targets for these diseases.

肌萎缩性外侧硬化症（ALS）和脊柱肌肉萎缩（SMA）是致命的神经系统疾病 涉及脊柱运动神经元的选择性变性。 SMA - 婴儿最常见的遗传原因 死亡率 - 是一种由生存运动神经元（SMN）宽度缺乏引起的单基因疾病 由于缺失SMN1基因而引起的蛋白质。相反，ALS主要是零星疾病，但在 少数家庭病例，超过20种不同基因的突变会导致运动神经元变性。遗传和 分子研究越来越多地表明，ALS和SMA可能具有共同的潜在机制 疾病。该项目重点是由RNA结合蛋白突变引起的一种族ALS 融合在肉瘤（FUS）中 - 与广泛的临床表型有关 最具侵略性，少年发作的疾病形式 - SMN生物学在 FUS依赖性运动神经元变性的发病机理。 SMN在 参与潜水mRNA加工途径和 越来越多的证据将依赖SMN的RNA失调与SMA病因联系起来。值得注意的是，最近 对培养的哺乳动物细胞和ALS患者的成纤维细胞的研究表明，FUS耗竭或 ALS连接的FUS突变的表达破坏了SMN在核体上的正常定位 宝石。此外，已显示FUS与SMN以及特定的SNRNP相关 生物发生是SMN依赖性的，可能会因ALS连接的FUS突变而破坏。在一起，这些发现 表明FUS和SMN通过共享分子途径在功能上连接并支持 观察SMA和ALS是相关的运动神经元疾病。但是，FUS的正常要求 尚未定义SNRNP生物发生和FUS突变对SMN生物学的致病影响 从机械上讲，SMN功能障碍对FUS-ALS病理学的贡献仍然未知。解决 这些出色的问题直接采用了一种系统的，多学科的方法，涉及新颖 FUS依赖性ALS的小鼠模型，以探索FUS介导的潜在SMN依赖性机制 运动神经元变性。在AIM 1中，我们将研究减少和增加的表型效应 ALS小鼠模型中FUS依赖性运动神经元病理学上的SMN表达。在AIM2中，我们将雇用 一组全面的分子方法，以建立正常和致病性的功能相关性 使用细胞的组合，在运动神经元中SnRNP生物发生途径中的FUS-SMN相互作用 和动物模型系统。这些研究旨在在ALS中建立收敛机制，并 SMA并将对与电机相关的FUS和SMN的生物学产生更完整的了解 神经元的生存。识别导致死亡和功能障碍的共享分子途径 SMA和ALS中的神经元也可能扩大这些疾病的治疗靶点范围。