Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Perth, Australia.
Mol Ther Nucleic Acids. 2012 Oct 16;1(10):e48. doi: 10.1038/mtna.2012.40.
Protein-truncating mutations in the dystrophin gene lead to the progressive muscle wasting disorder Duchenne muscular dystrophy, whereas in-frame deletions typically manifest as the milder allelic condition, Becker muscular dystrophy. Antisense oligomer-induced exon skipping can modify dystrophin gene expression so that a disease-associated dystrophin pre-mRNA is processed into a Becker muscular dystrophy-like mature transcript. Despite genomic deletions that may encompass hundreds of kilobases of the gene, some dystrophin mutations appear "leaky", and low levels of high molecular weight, and presumably semi-functional, dystrophin are produced. A likely causative mechanism is endogenous exon skipping, and Duchenne individuals with higher baseline levels of dystrophin may respond more efficiently to the administration of splice-switching antisense oligomers. We optimized excision of exons 8 and 9 in normal human myoblasts, and evaluated several oligomers in cells from eight Duchenne muscular dystrophy patients with deletions in a known "leaky" region of the dystrophin gene. Inter-patient variation in response to antisense oligomer induced skipping in vitro appeared minimal. We describe oligomers targeting exon 8, that unequivocally increase dystrophin above baseline in vitro, and propose that patients with leaky mutations are ideally suited for participation in antisense oligomer mediated splice-switching clinical studies.Molecular Therapy - Nucleic Acids (2012) 1, e48; doi:10.1038/mtna.2012.40; published online 16 October 2012.
肌营养不良蛋白基因中的蛋白截断突变导致进行性肌肉消耗障碍杜氏肌营养不良症,而框内缺失通常表现为较轻的等位基因状态,贝克肌营养不良症。反义寡核苷酸诱导的外显子跳跃可以修饰肌营养不良蛋白基因的表达,从而使疾病相关的肌营养不良蛋白前体 RNA 被加工成类似于贝克肌营养不良症的成熟转录本。尽管基因组缺失可能包含数百千碱基对的基因,但一些肌营养不良蛋白突变似乎是“渗漏的”,并且会产生低水平的高分子量、可能具有部分功能的肌营养不良蛋白。一种可能的致病机制是内源性外显子跳跃,并且具有较高基线肌营养不良蛋白水平的杜氏肌营养不良症个体可能对施用剪接转换反义寡核苷酸更有效。我们优化了正常人肌母细胞中外显子 8 和 9 的切除,并在已知肌营养不良蛋白基因“渗漏”区域缺失的 8 名杜氏肌营养不良症患者的细胞中评估了几种寡核苷酸。体外反义寡核苷酸诱导跳跃反应的患者间变异性似乎最小。我们描述了针对外显子 8 的寡核苷酸,可在体外明确增加肌营养不良蛋白的基线水平,并提出渗漏突变患者非常适合参与反义寡核苷酸介导的剪接转换临床研究。分子治疗 - 核酸(2012 年)1,e48;doi:10.1038/mtna.2012.40;在线发表 2012 年 10 月 16 日。