Experimental Therapy of Myotonic Dystrophy

强直性肌营养不良的实验治疗 强直性肌营养不良1型（DM1），成人中最普遍的肌营养不良形式，导致 进行性残疾和过早死亡。没有减缓进展或逆转症状的治疗 目前，DM1已经上市。这种疾病是由3'端非翻译区CTG重复序列的扩增引起的。 DMPK基因的区域，这导致了一种新的RNA介导的疾病过程。本项目的重点 正在进行治疗开发RNA疾病机制似乎提供了一种独特的治疗方法， DM1的机会。已经确定了可行的治疗目标，有迹象表明， DM1的症状可能会令人惊讶地被证明是可逆的。RNA结合蛋白活性的变化是一种 这种疾病的根本原因。肌盲蛋白1（MBNL1）与CUG有直接的相互作用 扩增（CUGexp）RNA，这导致病灶中的蛋白质隔离， 细胞核，以及一组特定的前mRNA的错误调节的选择性剪接。生化异常 DM 1小鼠模型中的生理缺陷对MBNL1的水平敏感。在转基因小鼠中， 当MBNL1降低时，CUGexp RNA引起的表型加重，当CUGexp RNA水平降低时，CUGexp RNA引起的表型减轻。 这种蛋白质增加，表明突变RNA和MBNL1蛋白质的化学计量是一个关键， 疾病活动的决定因素。我们提出了一种三管齐下的方法来开发DM1的治疗方法。目的 1采用系统性AAV介导的基因治疗来增加MBNL1表达。这一目标建立在 先前的工作表明，局部注射MBNL1基因治疗载体可以逆转肌肉缺陷， DM1转基因小鼠模型。目的2提出开发一种小分子，口服生物可利用的治疗 在转录后水平上调MBNL1蛋白。AIM3将使用吗啉代反义核酸 通过使用由CAG重复序列组成的寡核苷酸来杂交CUGexp RNA并置换隔离的蛋白质。 这一目标建立在初步研究的基础上，初步研究表明该材料耐受性良好，可有效逆转 转基因小鼠的肌强直和生化缺陷。我们建议确定这种策略是否可以防止 或逆转DM1条件性小鼠模型中的肌肉萎缩。总的来说，这个项目将改善我们的 了解疾病的发病机制，并继续翻译最近的机制见解的过程 用于治疗1型糖尿病患者

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.