Experimental Therapy of Myotonic Dystrophy

强直性肌营养不良症的实验治疗 强直性肌营养不良1型(DM1)是成人最常见的肌营养不良症，可导致 进行性残疾和过早死亡。没有任何治疗方法可以延缓病情进展或逆转症状 的DM1目前可用。这种疾病是由3‘端未翻译的CTG重复序列的扩大引起的 DMPK基因的区域，这导致了一种新的，RNA介导的疾病过程。这个项目的重点是 是关于治疗的发展。似乎rna病的机制提供了一种独特的治疗方法。 DM1中的商机。已经确定了可行的治疗目标，有迹象表明， DM1的症状可能会被证明是令人惊讶的可逆的。RNA结合蛋白活性的变化是一种 这种疾病的基本特征。粘虫蛋白1(MBNL1)与CUG有直接相互作用 扩展(CUGexp)RNA，导致蛋白质在病灶中隔离，MBNL1功能缺陷 核，以及一组特定的前mRNAs的错误调控的选择性剪接。生化异常 而DM1小鼠模型的生理缺陷对MBNL1水平敏感。在转基因小鼠中， 当MBNL1减少时，CUGexp RNA引起的表型加重，当 这种蛋白的增加，表明突变的RNA和MBNL1蛋白的化学计量是关键 疾病活动性的决定因素。我们提出了一个三管齐下的方法来开发DM1的治疗方法。目标 1采用全身性AAV介导的基因治疗来增加MBNL1的表达。这一目标建立在 以往的工作表明，局部注射MBNL1基因治疗载体可以逆转兔骨骼肌缺损 DM1转基因小鼠模型的建立。目标2建议开发一种小分子、口服生物利用度疗法。 在转录后水平上调MBNL1蛋白。目标3将使用吗啡反义技术 由CAG重复序列组成的寡核苷酸，与CUGexp RNA杂交并取代隔离的蛋白质。 这一目标建立在初步研究表明这种材料具有良好的耐受性和逆转效果的基础上。 转基因小鼠的肌强直和生化缺陷。我们建议确定这一策略是否可以防止 或者在有条件的DM1小鼠模型中逆转肌肉萎缩。总体而言，这个项目将改善我们的 理解疾病的发病机制并继续翻译最新的机械学见解的过程 用于DM1患者的治疗。

Experimental Therapy of Myotonic Dystrophy Myotonic dystrophy type 1 (DM1), the most prevalent form of muscular dystrophy in adults, leads to progressive disability and premature death. No treatment that slows the progress or reverses the symptoms of DM1 is currently available. This disorder is caused by expansion of a CTG repeat in the 3' untranslated region of the DMPK gene, which leads to a novel, RNA-mediated disease process. The focus of this project is on therapeutic development. It appears that RNA-disease mechanisms provide a unique therapetic opportunity in DM1. Viable targets for treatment have been identified, and there are indications that symptoms of DM1 may prove to be surprisingly reversible. Changes in activity of RNA binding proteins are a fundamental aspect of this disease. Muscleblind 1 (MBNL1) protein has a direct interaction with CUG expansion (CUGexp) RNA, which leads to protein sequestration in foci, functional deficiency of MBNL1 in the nucleus, and misregulated alternative splicing for a specific group of pre-mRNAs. Biochemical abnormalities and physiological defects in mouse models of DM1 are sensitive to levels of MBNL1. In transgenic mice, phenotypes caused by CUGexp RNA are aggravated when MBNL1 is reduced and mitigated when levels of this protein are increased, suggesting that stoichiometry of mutant RNA and MBNL1 protein is a key determinant of disease activity. We propose a three-pronged approach to develop treatments for DM1. Aim 1 employs systemic AAV-mediated gene therapy to increase MBNL1 expression. This aim builds on previous work showing that local injection of MBNL1 gene therapy vector can reverse muscle defects in a transgenic mouse model of DM1. Aim 2 proposes to develop a small molecule, orally bioavailable treatment to upregulate MBNL1 protein at a post-transcriptional level. Aim 3 will employ morpholino antisense oligonucleotides, consisting of CAG repeats, to hybridize CUGexp RNA and displace sequestered proteins. This aim builds on preliminary studies indicating that this material is well tolerated and effective for reversing myotonia and biochemical defects in transgenic mice. We propose to determine if this strategy can prevent or reverse muscle wasting in a conditional mouse model of DM1. Overall, this project will improve our understanding of disease pathogenesis and continue the process of translating recent mechanistic insights into treatments for people with DM1.