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.

肌萎缩侧索硬化症（ALS）和脊髓性肌萎缩症（SMA）是致命的神经系统疾病， 涉及脊髓运动神经元的选择性变性。SMA -婴儿最常见的遗传原因 死亡-是一种单基因疾病引起的广泛缺乏生存运动神经元（SMN） 由于SMN 1基因的缺失，相比之下，ALS主要是一种散发性疾病，但在一个 在少数家族性病例中，超过20种不同基因的突变导致运动神经元变性。遗传和 越来越多的分子研究表明，ALS和SMA可能有共同的潜在机制， 疾病该项目的重点是由RNA结合蛋白突变引起的一种家族性ALS 融合肉瘤（FUS）-与广泛的临床表型相关，包括一些 最具侵略性的，青少年发病形式的疾病-和SMN生物学的可能作用， FUS依赖性运动神经元变性的发病机制。SMN在以下方面具有完善的功能： 参与多种mRNA加工途径的小核核糖核蛋白（snRNP）的组装， 越来越多的证据将SMN依赖性RNA失调与SMA的病因联系起来。值得注意的是， 在培养的哺乳动物细胞和ALS患者的成纤维细胞中的研究已经表明，FUS消耗或 ALS连锁的FUS突变的表达破坏了SMN在核小体上的正常定位， 宝石.此外，FUS已被证明与SMN以及特定的snRNP相关， 生物发生是SMN依赖性的，并且可能被ALS连锁的FUS突变破坏。总之，这些发现 表明FUS和SMN通过共享的分子途径在功能上连接，并支持 认为SMA和ALS是相关的运动神经元疾病。然而，FUS的正常要求是 snRNP生物发生和FUS突变对SMN生物学的致病影响尚未确定 SMN功能障碍对FUS-ALS病理学的贡献仍然未知。解决 这些突出的问题直接，我们的项目采取了系统的，多学科的方法，涉及新的 FUS依赖性ALS小鼠模型，以探索FUS介导的潜在SMN依赖性机制 运动神经元变性在目标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的SMN表达。在Aim 2中，我们将使用 一套全面的分子方法来建立正常和致病的功能相关性， 运动神经元中snRNP生物合成途径中的FUS-SMN相互作用，使用细胞内 和动物模型系统。总的来说，这些研究旨在建立ALS的会聚机制， SMA，并将产生一个更完整的了解FUS和SMN的生物学是相关的运动 神经元存活鉴定导致死亡和运动功能障碍的共同分子途径 SMA和ALS中的神经元也可能扩大这些疾病的治疗靶点范围。