RNA Processing Defects in SMA and Their Contribution to the Disease Phenotype

SMA 中的 RNA 加工缺陷及其对疾病表型的贡献

• 批准号: 9265971
• 负责人: Wilfried Rossoll
• 金额: $ 34.23万
• 依托单位: MAYO CLINIC JACKSONVILLE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9265971
• 关键词: Active Biological Transport; Affect; Animal Model; Axon; Binding; Binding Proteins; Biological; Catalogs; Cells; Defect; Denervation; Development; Disease; Functional disorder; Genes; Genetic; Goals; Growth Cones; Housekeeping; Human Pathology; Impairment; In Vitro; Knowledge; Link; Maintenance; Mediating; Messenger RNA; Microfilaments; Microtubules; Modeling; Molecular; Molecular Chaperones; Molecular and Cellular Biology; Morphology; Motor; Motor Neuron Disease; Motor Neurons; Multiprotein Complexes; Mus; Muscular Atrophy; Mutation; Nerve; Nerve Degeneration; Neurodegenerative Disorders; Neuromuscular Diseases; Neuromuscular Junction; Neurons; Outcome; Pathology; Pathway interactions; Patients; Play; Process; Proteins; Proteome; Proteomics; Public Health; RNA; RNA Processing; RNA Splicing; Research; Ribonucleoproteins; Ribosomes; Role; SMN protein (spinal muscular atrophy); Small Nuclear Ribonucleoproteins; Spinal; Spinal Cord; Spinal Muscular Atrophy; Stem cells; Synapses; System; Tail; Testing; Therapeutic Intervention; Time; Tissues; Transcript; Transduction Gene; Translations; Up-Regulation; Vertebrates; Viral; axon growth; axonal degeneration; base; cell type; disease phenotype; experimental study; in vivo; in vivo Model; infant death; insight; mRNA Precursor; messenger ribonucleoprotein; motor neuron degeneration; mouse model; neurodevelopment; neuromuscular; neuromuscular system; new therapeutic target; novel; novel therapeutics; public health relevance; survival motor neuron gene; therapy development; trafficking; transcriptome; transcriptome sequencing

 DESCRIPTION (provided by applicant): Spinal muscular atrophy (SMA) is a devastating neurodegenerative disease that represents the most common genetic cause of infant death. SMA is caused by reduced levels of functional survival of motor neuron (SMN) protein, leading to cell autonomous defects at the neuromuscular junctions, axon degeneration, and loss of motor neurons in the spinal cord. The ubiquitously expressed SMN protein has a well characterized essential function in the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs) in all tissues, but it is still unclear to what extent pre-mRNA splicing defects contribute to SMA. It is a central question in the field why spinal motor neurons are more severely affected by low SMN protein levels than other cell types. We and others have shown that SMN is also present in highly mobile multi-protein complexes that are actively transported along microtubules and actin filaments in axons of cultured neurons. More recently, we have discovered that axons of cultured SMN-deficient motor neurons have impaired localization of specific mRNA binding proteins (mRBPs) and mRNAs in axons that are known to play roles in axon growth. These findings have led us to hypothesize that SMN plays a critical role in the assembly and trafficking of messenger ribonucleoproteins (mRNPs) in neuronal processes that serve axonal growth and maintenance. However, how defects in these SMN-dependent processes may contribute to the SMA pathomechanism is still unknown. With the goal to reveal mRNA processing defects in SMA and their contribution to the disease phenotype, we propose two specific aims: in Aim 1, we will uncover disease-specific molecular axonal defects by a de- tailed and comprehensive analysis of differences in the axonal transcriptome and proteome. The use of novel SMA patient stem cell-derived motor neurons and compartmentalized cultures will allow us for the first time to comprehensively catalogue SMA-specific defects in mRNA processing and their consequences on axon development, and identify ways to rescue these defects. These studies will provide insight into mRNA processing defects in SMA patient stem cell-derived motor neurons and how they contribute to axonal defects in vitro. In Aim 2, we will use cell type-specific tagging of ribosomes with the RiboTag system to thoroughly characterize differences in the ribosome-associated transcriptome in spinal cord motor neurons of SMA mouse models. We will characterize axonal localization of known SMN targets, and rescue these axonal defects in SMA mice via AAV9-based viral transduction of genes that enhance axonal mRNP localization. These experiments will allow for the first time the assessment of the spectrum of mRNA processing defects in spinal motor neurons from an SMA mouse model and how they contribute to the disease phenotype in vivo. This proposal is expected to both increase our understanding of human pathology in the neuromuscular sys- tem, and to facilitate the development of therapies that are specifically targeted at mRNA processing defects in motor neurons in SMA and related neuromuscular diseases.

 描述：脊柱肌肉萎缩（SMA）是毁灭性神经退行性C的病因，SMA是由运动神经元（SMN）蛋白的功能生存水平降低引起的脊髓中的运动神经元在所有组织R中的剪接核核糖核蛋白（SNRNP）中的基本功能在何种程度上与其他细胞类型相比，SMN也存在于何种程度上。在培养的神经元中积极运输的流动多蛋白复合物，发现培养的运动神经元的轴突损害了特定的mRNA Bindins（MRBPS）的定位，这些轴是在轴突生长中起着作用SMN在轴突生长和维持的神经元过程中起着至关重要的作用。 SMA的处理缺陷及其对疾病表型的贡献，我们提出了两个具体的目的：在AIM 1中，我们将通过对轴突转录组中的差异和原生动物的差异分析来揭示疾病特异性的分子轴突缺陷培养物将首次在mRNA散文中进行分类，这些研究将对SMA患者干细胞衍生的运动神经元的mRNA加工进行培养，以及它们如何在AIM 2中促进轴突缺陷。核糖体系统的特定标记以彻底表征与核糖体相关的三个脊髓运动神经元的脊髓运动神经元，该神经元通过基于AAV9的基因轴突MRNP定位的基因的Viral Trancuction eav9 smn靶标。脊柱运动神经元中的mRNA处理缺陷来自smouse模型，以及它们如何在体内促进疾病表型。 SMA中的运动神经元和相关的神经肌肉疾病。