Modulation of Jagged1/Pitpna in DMD as a means of therapy

DMD 中 Jagged1/Pitpna 的调节作为治疗手段

• 批准号: 10447111
• 负责人: LOUIS M KUNKEL
• 金额: $ 38.55万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10447111
• 关键词: Affect; Bioinformatics; Blood flow; Canis familiaris; Cardiopulmonary; Cell Line; Cell model; Cessation of life; Clinical Research; Complement; Control Animal; DNA Sequence Alteration; Data; Disease; Disease Progression; Down-Regulation; Duchenne muscular dystrophy; Dystrophin; Evaluation; Exhibits; Failure; Fibrosis; Gene Expression Profiling; Generations; Genes; Genetic; Genetic study; Goals; Grant; Human; In Vitro; Injections; Investigation; Life; Longevity; Messenger RNA; Modeling; Mus; Muscle; Muscle Cells; Muscle function; Muscular Atrophy; Muscular Dystrophies; Myoblasts; Outcome; PTEN gene; Pathology; Pathway interactions; Patient-Focused Outcomes; Patients; Performance; Pharmacology; Phenotype; Phosphatidylinositol Transfer Protein; Predisposition; Proteins; Proto-Oncogene Proteins c-akt; Reading Frames; Replacement Therapy; Research; Role; Sarcolemma; Signal Pathway; Signal Transduction; Skeletal Muscle; Swimming; Symptoms; Terminator Codon; Testing; Therapeutic; Transgenic Organisms; Translations; Viral; Zebrafish; adeno-associated viral vector; base; comparative; disease-causing mutation; exon skipping; experimental study; follow-up; heart function; improved; in vivo; inhibitor; inhibitor therapy; knock-down; mini-dystrophin; mouse model; muscle degeneration; muscular structure; overexpression; premature; prevent; restoration; targeted treatment; therapeutic target; treatment strategy

PROJECT SUMMARY/ABSTRACT Duchenne Muscular Dystrophy (DMD) is a degenerative muscle wasting disease caused by mutations in the dystrophin gene. The absence of dystrophin protein at the muscle sarcolemma results in increased muscle susceptibility to contraction-induced damage as well as dysregulation of secondary signaling pathways, many of which remain poorly understood. Despite advances in treatment strategies under investigation aimed at restoration of dystrophin expression including viral delivery of mini-dystrophin, read-through of translation stop codons, and exon skipping to restore the reading frame, there is no cure for DMD, and the identification of therapies that improve pathology independent of dystrophin would be of significant value to patients. In this vain, genetic modifiers of DMD are emerging as potential therapeutic targets. Our lab recently identified Jagged1 and Pitpna as genetic modifiers of DMD pathology in a Golden Retriever Muscular Dystrophy (GRMD) dog colony in which two exceptional “escaper” dogs exhibited a drastically milder phenotype than typical GRMD dogs despite being dystrophin-deficient. Normally, GRMD dogs show a severe phenotype similar to human DMD including early progressive muscle degeneration, fibrosis, and premature death often within the first 2 years of life due to cardiopulmonary failure. Gene expression analyses of the escaper dogs compared to severely affected GRMD dogs and control animals revealed that Jagged1 overexpression (OE) and decreased Pitpna expression were hallmarks of the mild phenotype, which including maintained ambulation and normal lifespan. In subsequent genetic studies of dystrophin-deficient zebrafish, we demonstrated that modulation of Jagged1 and Pitpna prevents manifestation of the dystrophic muscle phenotype, increases long-term survival, and improves swim performance. In primary myoblasts derived from normal and DMD patients, we also showed that Jagged1 overexpression and Pitpna inhibition impact AKT/PTEN signaling and improve myoblast fusion. Given this positive data, we will now extend our research of Jagged1 and Pitpna modulation into the well-characterized mdx5cv mouse model of DMD. We will also investigate genetic and pharmacological inhibition of PDE10A, which we have shown to elicit decreased Pitpna expression and improve dystrophic pathology in dystrophin-deficient zebrafish. The long-term goal in this project is to assess and validate the therapeutic potential of the genetic modifiers Jagged1 and Pitpna to ameliorate DMD pathology, and to identify a viable pharmacologic modulator to advance into clinical studies. To accomplish this, we will implement experiments in accordance to the following three specific aims: 1) Determine the effect of reduced Pitpna expression on dystrophic pathology in mdx5cv mice, 2) Characterize the functional role of Jagged1 overexpression in mdx5cv mice, and 3) Assess the therapeutic potential of PDE10A inhibition on dystrophic pathology in primary human muscle cells, zebrafish, and mouse models of DMD.

项目总结/摘要 杜氏肌营养不良症（DMD）是一种退行性肌肉萎缩性疾病， dystrophin基因肌肉肌膜中肌营养不良蛋白的缺失导致肌肉萎缩， 对收缩引起的损伤的敏感性以及次级信号通路的失调，许多 其中的原因至今仍知之甚少。尽管正在研究的治疗策略取得了进展， 肌营养不良蛋白表达的恢复，包括微型肌营养不良蛋白的病毒递送，翻译终止的通读 密码子和外显子跳跃来恢复阅读框架，DMD没有治愈的方法， 独立于抗肌萎缩蛋白改善病理的疗法对患者具有重要价值。在这 DMD的无效的遗传修饰剂正在成为潜在的治疗靶点。我们的实验室最近发现 Jagged 1和Pitpna作为金毛猎犬肌营养不良症DMD病理学的遗传修饰因子 （GRMD）狗群，其中两只特殊的“逃脱者”狗表现出比 典型的GRMD狗，尽管是肌营养不良蛋白缺陷。正常情况下，GRMD狗表现出严重的表型 类似于人类DMD，包括早期进行性肌肉变性、纤维化和过早死亡， 由于心肺衰竭，在生命的前2年内。逃逸犬的基因表达分析 与严重受影响的GRMD狗和对照动物相比，Jagged 1过表达（OE） 和Pitpna表达减少是轻度表型的标志，包括维持 和正常的寿命。在随后对肌营养不良蛋白缺陷斑马鱼的遗传研究中，我们 表明Jagged 1和Pitpna的调节可以防止营养不良肌肉的表现， 表型，增加长期生存，并提高游泳性能。在来源于 我们还发现，Jagged 1过表达和Pitpna抑制影响了正常人和DMD患者的神经功能。 AKT/PTEN信号传导和改善成肌细胞融合。鉴于这些积极的数据，我们现在将扩大我们的研究， Jagged 1和Pitpna调节到充分表征的DMD mdx 5cv小鼠模型中。我们还将 研究PDE 10A的遗传和药理学抑制，我们已经证明PDE 10A引起Pitpna降低 表达并改善肌营养不良蛋白缺陷斑马鱼中的营养不良病理学。长期目标是 该项目旨在评估和验证遗传修饰剂Jagged 1和Pitpna的治疗潜力， 改善DMD病理，并确定可行的药理学调节剂以推进临床研究。 为了实现这一目标，我们将按照以下三个具体目标进行实验： 确定降低的Pitpna表达对mdx 5cv小鼠中营养不良病理学的影响。 在mdx 5cv小鼠中Jagged 1过表达的功能作用，和3）评估PDE 10A的治疗潜力 对DMD的原代人肌细胞、斑马鱼和小鼠模型中营养不良病理学的抑制。