Effect of Ataluren on dystrophin mutations
Effect of Ataluren on dystrophin mutations
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DOI：
10.1111/jcmm.15319
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发表时间：
2020-04-28
影响因子：
5.3
通讯作者：
Currie, Peter D.
中科院分区：
文献类型：
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作者：
Berger, Joachim;Li, Mei;Currie, Peter D.
杜氏肌营养不良症是由肌营养不良蛋白基因（dmd）突变引起的一种严重的肌肉萎缩疾病。Ataluren已被欧洲药品管理局批准用于治疗杜氏肌营养不良症。据报道，Ataluren可促进核糖体过早终止密码子的读取，导致全长肌营养不良蛋白的恢复。然而，Ataluren的作用机制尚未得到充分的描述。为了评估Ataluren对三种不同终止强度的过早终止密码子（UAA > UAG > UGA）的作用，我们培育了新型抗肌营养不良蛋白缺陷斑马鱼。通过双折射定量（一种直接测量肌肉完整性的工具）对肌肉进行病理评估，在受精后3天，没有发现Ataluren对任何分析的肌营养不良蛋白缺陷突变体有显著影响。通过直接测量产生的力对受精后6天肌肉组织的功能分析显示，Ataluren仅对携带uaa的突变体dmd（ta222a）有显著改善。然而，有趣的是，所有其他分析的肌营养不良蛋白缺陷突变体都没有受到Ataluren的影响，包括分别含有较弱的过早停止密码子UAG和UGA的dmd（pc3）和dmd（pc2）突变体。这些体内结果与Ataluren体外疗效的报道数据相矛盾，表明Ataluren可能不会促进过早终止密码子的读取。此外，Ataluren对抗肌营养不良蛋白转录水平没有影响，但对野生型幼虫有轻微的不良影响。对n端截断的肌营养不良蛋白的进一步评估开启了Ataluren促进肌营养不良蛋白内替代翻译密码子的可能性，从而有可能改变适用于Ataluren的患者群体。
Duchenne muscular dystrophy is a severe muscle wasting disease caused by mutations in the dystrophin gene (dmd). Ataluren has been approved by the European Medicines Agency for treatment of Duchenne muscular dystrophy. Ataluren has been reported to promote ribosomal read-through of premature stop codons, leading to restoration of full-length dystrophin protein. However, the mechanism of Ataluren action has not been fully described. To evaluate the efficacy of Ataluren on all three premature stop codons featuring different termination strengths (UAA > UAG > UGA), novel dystrophin-deficient zebrafish were generated. Pathological assessment of the muscle by birefringence quantification, a tool to directly measure muscle integrity, did not reveal a significant effect of Ataluren on any of the analysed dystrophin-deficient mutants at 3 days after fertilization. Functional analysis of the musculature at 6 days after fertilization by direct measurement of the generated force revealed a significant improvement by Ataluren only for the UAA-carrying mutant dmd(ta222a). Interestingly however, all other analysed dystrophin-deficient mutants were not affected by Ataluren, including the dmd(pc3) and dmd(pc2) mutants that harbour weaker premature stop codons UAG and UGA, respectively. These in vivo results contradict reported in vitro data on Ataluren efficacy, suggesting that Ataluren might not promote read-through of premature stop codons. In addition, Ataluren had no effect on dystrophin transcript levels, but mild adverse effects on wild-type larvae were identified. Further assessment of N-terminally truncated dystrophin opened the possibility of Ataluren promoting alternative translation codons within dystrophin, thereby potentially shifting the patient cohort applicable for Ataluren.