Targeting SMN2 Alternative Splicing for the Treatment of Spinal Muscular Atrophy

靶向 SMN2 选择性剪接治疗脊髓性肌萎缩症

• 批准号: 7866381
• 负责人: Michelle L Hastings
• 金额: $ 33.69万
• 依托单位: ROSALIND FRANKLIN UNIV OF MEDICINE & SCI
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7866381
• 关键词: Alternative Splicing; Animal Disease Models; Animal Model; Biochemical; Biological Assay; Biology; Cell model; Cells; Chemistry; Childhood; Clinical; Code; Data; Defect; Disease; Effectiveness; Event; Exons; Family; Frequencies; Future; Gene Expression; Gene Proteins; Genetic; Goals; Health; Hereditary Disease; Human; In Vitro; Infant Mortality; Interdisciplinary Study; Lead; Length; Live Birth; Messenger RNA; Methods; Modeling; Molecular; Molecular Target; Motor Neurons; Mutation; Neurodegenerative Disorders; Outcome; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Pharmacology; Preclinical Drug Development; Process; Protein Isoforms; Proteins; Qualifying; RNA; RNA Binding; RNA Splicing; Reaction; Research; SMN1 gene; SMN2 gene; Screening procedure; Specificity; Spinal Muscular Atrophy; Spliceosomes; Structure; Symptoms; System; Testing; Tetracyclines; Therapeutic; Transcript; base; cell type; design; effective therapy; human disease; improved; in vivo; induced pluripotent stem cell; innovation; insight; mRNA Precursor; motor neuron degeneration; nervous system disorder; novel; novel strategies; pharmacokinetic characteristic; protein expression; public health relevance; research study; small molecule; stem cell biology; survival motor neuron gene; therapeutic development; tool; treatment strategy

DESCRIPTION (provided by applicant): The long term objective of this project is to develop methods to therapeutically target defects in pre-mRNA splicing that cause human disease. One disease that can potentially be cured by targeting pre- mRNA splicing is spinal muscular atrophy (SMA). SMA is a pediatric neurodegenerative disease for which there is currently no cure or effective therapy. The disease is caused by the homozygous loss of the survival of motor neuron, SMN1, gene. Humans have a second gene, SMN2, which is nearly identical to SMN1. Both SMN1 and SMN2 code for SMN protein. However, the majority of SMN2 mRNA transcripts splice out exon 7. This alternative mRNA isoform codes for a truncated, unstable protein. Thus, SMA results from the reduction of SMN protein levels caused by the loss of SMN1. The presence of SMN2 in most SMA patients provides a unique opportunity to treat the disease by increasing SMN2 exon 7 splicing and thereby restoring SMN levels. We have recently identified a tetracycline derivative that improves SMN protein levels by directly targeting the splicing reaction to increase SMN2 exon 7 splicing. This compound is particularly attractive as a therapeutic due to the favorable pharmacokinetic characteristics of the tetracycline family of molecules and because the compound appears to act at a very specific step in the gene expression pathway. The goal of our application is to develop this potent activator of SMN2 splicing as a therapeutic for the treatment of SMA and potentially other diseases caused by splicing defects. The central hypothesis of the study is that targeting defective splicing in diseases such as SMA will lead to a therapeutic increase in protein expression. Aim 1 of this study is to use induced pluripotent stem cells derived from SMA patients to determine the effectiveness of splicing effector molecules, such as the tetracycline derivatives, in rescuing motor neuron degeneration and also to characterize the cellular consequences of SMN protein loss during motor neuron degeneration. Aim 2 is to identify the molecular target and mechanism of action by which tetracycline derivatives increase SMN2 splicing. Aim 3 is to discover novel targets and develop alternative strategies for SMA therapy. The proposed experiments will provide insights and therapeutics for the treatment of SMA and will also advance therapeutic approaches to treat other diseases caused by splicing defects. These studies will also have a broad impact on our understanding of induced pluripotent stem cells as models for human disease and the cellular defects of SMN protein loss in motor neurons of SMA patients. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to discover and develop effective therapeutics for the treatment of the pediatric neurodegenerative disease, spinal muscular atrophy (SMA), and other human diseases that have common molecular defects for which there is currently no cure. Compounds based on the structure of the antibiotic tetracycline have been identified as modulators of a defect in spinal muscular atrophy. This class of drug is relatively safe and would be an ideal therapeutic for the treatment of disease.

描述（由申请人提供）：该项目的长期目标是开发方法，以治疗靶向引起人类疾病的MRNA剪接中的缺陷。一种可能通过靶向前mRNA剪接来治愈的疾病是脊柱肌肉萎缩（SMA）。 SMA是一种儿科神经退行性疾病，目前尚无治愈或有效治疗。该疾病是由运动神经元SMN1，基因生存的纯合丧失引起的。人类具有第二个基因SMN2，该基因与SMN1几乎相同。 SMN1和SMN2代码均用于SMN蛋白。然而，大多数SMN2 mRNA转录本将外显子7。这种替代的mRNA同工型编码截断，不稳定的蛋白质。因此，SMA是由于SMN1丢失引起的SMN蛋白水平的降低而引起的。在大多数SMA患者中，SMN2的存在提供了一个独特的机会来通过增加SMN2外显子7剪接并恢复SMN水平来治疗该疾病。我们最近确定了四环素衍生物，该衍生物通过直接靶向剪接反应来增加SMN2外显子7剪接来改善SMN蛋白水平。由于四环素分子家族的有利的药代动力学特性，因此该化合物特别有吸引力，因为该化合物似乎在基因表达途径中起着非常具体的步骤。我们应用的目的是开发这种有效的SMN2剪接激活因子作为治疗SMA和可能由剪接缺陷引起的其他疾病的治疗方法。该研究的中心假设是，靶向诸如SMA之类的疾病中的有缺陷的剪接将导致蛋白质表达的治疗性增加。这项研究的目标1是使用源自SMA患者的诱导多能干细胞来确定剪接效应子分子的有效性，例如四环素衍生物，以挽救运动神经元变性，并表征运动神经元变性过程中SMN蛋白质丧失的细胞后果。目标2是确定四环素衍生物增加SMN2剪接的分子靶标和作用机理。目标3是发现新颖的目标并制定SMA治疗的替代策略。提出的实验将为治疗SMA提供见解和治疗剂，还将进步治疗因剪接缺陷引起的其他疾病的治疗方法。这些研究还将对我们对诱导的多能干细胞作为人类疾病的模型以及SMA患者运动神经元中SMN蛋白损失的细胞缺陷的理解有广泛的影响。 公共卫生相关性：该提案的目的是发现并开发有效的治疗剂，以治疗小儿神经退行性疾病，脊柱肌肉萎缩（SMA）和其他具有常见分子缺陷的人类疾病，目前尚无治愈。基于抗生素四环素结构的化合物已被确定为脊柱肌肉萎缩缺陷的调节剂。这类药物相对安全，将是治疗疾病的理想治疗方法。