Department of Veterinary Clinical Sciences, Royal Veterinary College, London, United Kingdom.
PLoS One. 2010 Jan 13;5(1):e8647. doi: 10.1371/journal.pone.0008647.
Duchenne muscular dystrophy (DMD), which afflicts 1 in 3500 boys, is one of the most common genetic disorders of children. This fatal degenerative condition is caused by an absence or deficiency of dystrophin in striated muscle. Most affected patients have inherited or spontaneous deletions in the dystrophin gene that disrupt the reading frame resulting in unstable truncated products. For these patients, restoration of the reading frame via antisense oligonucleotide-mediated exon skipping is a promising therapeutic approach. The major DMD deletion "hot spot" is found between exons 45 and 53, and skipping exon 51 in particular is predicted to ameliorate the dystrophic phenotype in the greatest number of patients. Currently the mdx mouse is the most widely used animal model of DMD, although its mild phenotype limits its suitability in clinical trials. The Golden Retriever muscular dystrophy (GRMD) model has a severe phenotype, but due to its large size, is expensive to use. Both these models have mutations in regions of the dystrophin gene distant from the commonly mutated DMD "hot spot".
METHODOLOGY/PRINCIPAL FINDINGS: Here we describe the severe phenotype, histopathological findings, and molecular analysis of Cavalier King Charles Spaniels with dystrophin-deficient muscular dystrophy (CKCS-MD). The dogs harbour a missense mutation in the 5' donor splice site of exon 50 that results in deletion of exon 50 in mRNA transcripts and a predicted premature truncation of the translated protein. Antisense oligonucleotide-mediated skipping of exon 51 in cultured myoblasts from an affected dog restored the reading frame and protein expression.
CONCLUSIONS/SIGNIFICANCE: Given the small size of the breed, the amiable temperament and the nature of the mutation, we propose that CKCS-MD is a valuable new model for clinical trials of antisense oligonucleotide-induced exon skipping and other therapeutic approaches for DMD.
杜氏肌营养不良症（DMD）是一种常见的儿童遗传性疾病，每 3500 名男童中就有 1 名患病。这种致命的退行性疾病是由于横纹肌中缺乏或缺乏肌营养不良蛋白引起的。大多数受影响的患者都遗传或自发地出现肌营养不良蛋白基因缺失，从而破坏了阅读框，导致不稳定的截短产物。对于这些患者，通过反义寡核苷酸介导的外显子跳跃来恢复阅读框是一种很有前途的治疗方法。主要的 DMD 缺失“热点”位于外显子 45 和 53 之间，特别是跳过外显子 51，预计会使最多的患者的肌营养不良表型得到改善。目前，mdx 小鼠是 DMD 最广泛使用的动物模型，尽管其轻度表型限制了其在临床试验中的适用性。金毛寻回猎犬肌营养不良症（GRMD）模型具有严重的表型，但由于其体型较大，使用成本较高。这两种模型的肌营养不良蛋白基因都发生了突变，与常见的 DMD“热点”区域相距甚远。
方法/主要发现：在这里，我们描述了具有肌营养不良蛋白缺陷性肌营养不良症（CKCS-MD）的骑士查理王小猎犬的严重表型、组织病理学发现和分子分析。这些狗在 exon50 的 5'供体位点发生错义突变，导致 mRNA 转录物中外显子 50 的缺失和翻译蛋白的提前截短。来自受影响的狗的培养肌母细胞中的反义寡核苷酸介导的外显子 51 跳跃恢复了阅读框和蛋白表达。
结论/意义：鉴于该品种的体型较小、性格温顺以及突变的性质，我们建议 CKCS-MD 是一种有价值的新模型，可用于反义寡核苷酸诱导的外显子跳跃和其他治疗 DMD 的方法的临床试验。
Zotero 插件
