Dosing Regimen Has a Significant Impact on the Efficiency of Morpholino Oligomer-Induced Exon Skipping in mdx Mice
Dosing Regimen Has a Significant Impact on the Efficiency of Morpholino Oligomer-Induced Exon Skipping in mdx Mice
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DOI：
10.1089/hum.2008.157
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发表时间：
2009-09-01
影响因子：
4.2
通讯作者：
Graham, Ian R.
中科院分区：
文献类型：
--
作者：
Malerba, Alberto;Thorogood, Francesca C.;Graham, Ian R.
杜氏肌营养不良症 (DMD) 是一种肌退行性疾病，主要由导致肌营养不良蛋白翻译过早终止的突变引起。跳过肌营养不良蛋白外显子的反义寡核苷酸方法可以恢复肌营养不良蛋白转录物中的正确阅读框，从而产生更短的蛋白质。在人类身上采用类似的方法会导致 DMD 转化为较轻度的贝克尔肌营养不良症。先前已经证明，在 mdx 小鼠中重复血管内注射磷酸二酰胺吗啉寡聚物 (PMO) 比单次注射诱导更多的肌营养不良蛋白表达，但这种方法成本高昂，并且无法获得证明高剂量全身注射 PMO 安全性的数据。此外，一些出版物已经证明了肽缀合的 PMO 的功效，但此类化合物的临床适用性现阶段尚不清楚。在这里，我们报告说，与单次剂量相同总量相比，在给药8周后，多次血管内注射低剂量的裸PMO显示出在各种肌肉群中显着更多的肌营养不良蛋白阳性纤维。每公斤注射总共 200 毫克 PMO 后，重复注射治疗的小鼠的组织学特征（如横截面积、中心核指数和肌营养不良蛋白相关蛋白复合物的表达）显示出显着改善。此外，仅 5 mg/kg 的四次给药就诱导了大量的肌营养不良蛋白表达。这些结果清楚地证明了优化给药方案对于患者全身给予 PMO 的关键作用，并支持这种裸 PMO 方法的临床可行性。
Duchenne muscular dystrophy (DMD) is a myodegenerative disorder caused primarily by mutations that create premature termination of dystrophin translation. The antisense oligonucleotide approach for skipping dystrophin exons allows restoration of the correct reading frame in the dystrophin transcript, thus producing a shorter protein. A similar approach in humans would result in the conversion of DMD to the milder Becker muscular dystrophy. It has been demonstrated previously that repeated intravascular injection of phosphorodiamidate morpholino oligomers (PMOs) in the mdx mouse induces more dystrophin expression than a single injection, but this approach is costly, and data demonstrating the safety of high doses of systemically injected PMO are unavailable. Furthermore, several publications have demonstrated the efficacy of peptide-conjugated PMOs, but the clinical applicability of such compounds is unclear at this stage. Here, we report that multiple intravascular injections of low doses of naked PMO show significantly more dystrophin-positive fibers in a variety of muscle groups, 8 weeks after administration compared with a single dose of the same total amount. After administration of a total of 200 mg of PMO per kilogram, histological features, such as the cross-sectional area, centronucleation index, and expression of the dystrophin-associated protein complex, showed significant improvement in mice treated by repeated injection. Furthermore, four administrations of just 5 mg/kg induced a significant amount of dystrophin expression. These results clearly demonstrate the key role of the optimization of dosing regimen for the systemic administration of PMO in patients, and support the clinical feasibility of this approach with naked PMO.