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治疗靶向导致人类疾病的前信使核糖核酸剪接缺陷的方法。一种可能通过靶向前mRNA剪接而治愈的疾病是脊髓性肌萎缩症(SMA)。SMA是一种儿童神经退行性疾病，目前还没有治愈或有效的治疗方法。这种疾病是由运动神经元存活基因SMN1纯合缺失引起的。人类有第二个基因SMN1，它与SMN1几乎完全相同。SMN1和SMN2都编码SMN蛋白。然而，大多数SMN2mRNA转录产物剪接出外显子7。这种替代的mRNA亚型编码一种截短的、不稳定的蛋白质。因此，SMA是由于SMN1缺失导致SMN蛋白水平降低所致。在大多数SMA患者中，SMN2的存在提供了一个独特的机会，通过增加SMN2外显子7的剪接来治疗该病，从而恢复SMN水平。我们最近发现了一种四环素衍生物，它通过直接靶向剪接反应来增加SMN外显子7的剪接，从而提高SMN蛋白水平。由于四环素分子家族良好的药代动力学特性，以及该化合物似乎在基因表达途径中的一个非常特定的步骤起作用，这种化合物作为一种治疗药物特别有吸引力。我们的应用目标是开发这种有效的SMN2剪接激活剂，用于治疗SMA和潜在的由剪接缺陷引起的其他疾病。这项研究的中心假设是，针对SMA等疾病的有缺陷的剪接将导致蛋白质表达的治疗性增加。本研究的目的1是使用来自SMA患者的诱导多能干细胞，以确定剪接效应分子(如四环素衍生物)在挽救运动神经元变性中的有效性，并表征运动神经元变性过程中SMN蛋白丢失的细胞学后果。目的2确定四环素类化合物促进SMN2剪接的分子靶点和作用机制。目标3是发现新的靶点并开发SMA治疗的替代策略。拟议的实验将为SMA的治疗提供见解和治疗方法，并将推进治疗由剪接缺陷引起的其他疾病的方法。这些研究还将对我们理解诱导多能干细胞作为人类疾病的模型以及SMA患者运动神经元SMN蛋白丢失的细胞缺陷的理解产生广泛的影响。 公共卫生相关性：这项提案的目标是发现和开发有效的疗法来治疗儿童神经退行性疾病、脊髓性肌萎缩症(SMA)和其他人类疾病，这些疾病具有目前无法治愈的常见分子缺陷。基于抗生素四环素结构的化合物已被确定为脊髓性肌萎缩症缺陷的调节剂。这类药物相对安全，是治疗疾病的理想疗法。