Aupy Philippine, Zarrouki Faouzi, Sandro Quentin, Gastaldi Cécile, Buclez Pierre-Olivier, Mamchaoui Kamel, Garcia Luis, Vaillend Cyrille, Goyenvalle Aurélie
Université Paris-Saclay, UVSQ, INSERM, END-ICAP, 78000 Versailles, France.
Neuroscience Paris-Saclay Institute (Neuro-PSI), UMR 9197, Université Paris Sud, CNRS, Université Paris Saclay, 91190 Orsay, France.
Mol Ther Methods Clin Dev. 2020 May 4;17:1037-1047. doi: 10.1016/j.omtm.2020.04.025. eCollection 2020 Jun 12.
Gene therapy and antisense approaches hold promise for the treatment of Duchenne muscular dystrophy (DMD). The advantages of both therapeutic strategies can be combined by vectorizing antisense sequences into an adeno-associated virus (AAV) vector. We previously reported the efficacy of AAV-U7 small nuclear RNA (U7snRNA)-mediated exon skipping in the mouse, the mouse, and the golden retriever muscular dystrophy (GRMD) dog model. In this study, we examined the therapeutic potential of an AAV-U7snRNA targeting the human DMD exon 51, which could be applicable to 13% of DMD patients. A single injection of AAV9-U7 exon 51 (U7ex51) induces widespread and sustained levels of exon 51 skipping, leading to significant restoration of dystrophin and improvement of the dystrophic phenotype in the mouse. However, levels of dystrophin re-expression are lower than the skipping levels, in contrast with previously reported results in the mouse, suggesting that efficacy of exon skipping may vary depending on the targeted exon. Additionally, while low levels of exon skipping were measured in the brain, the dystrophin protein could not be detected, in line with a lack of improvement of their abnormal behavioral fear response. These results thus confirm the high therapeutic potential of the AAV-mediated exon-skipping approach, yet the apparent discrepancies between exon skipping and protein restoration levels suggest some limitations of this experimental model.
基因治疗和反义方法有望用于杜兴氏肌营养不良症（DMD）的治疗。通过将反义序列载体化到腺相关病毒（AAV）载体中，可以结合这两种治疗策略的优势。我们之前报道了AAV-U7小核RNA（U7snRNA）介导的外显子跳跃在小鼠、金黄猎犬肌营养不良症（GRMD）犬模型中的疗效。在本研究中，我们检测了靶向人类DMD外显子51的AAV-U7snRNA的治疗潜力，该外显子跳跃策略适用于13%的DMD患者。单次注射AAV9-U7外显子51（U7ex51）可诱导外显子51广泛且持续的跳跃水平，从而导致肌营养不良蛋白显著恢复，并改善mdx小鼠的营养不良表型。然而，与之前在mdx小鼠中报道的结果相比，肌营养不良蛋白的重新表达水平低于跳跃水平，这表明外显子跳跃的疗效可能因靶向的外显子而异。此外，虽然在大脑中检测到低水平的外显子跳跃，但未检测到肌营养不良蛋白，这与它们异常的行为恐惧反应未得到改善一致。因此，这些结果证实了AAV介导的外显子跳跃方法具有很高的治疗潜力，但外显子跳跃和蛋白恢复水平之间的明显差异表明了该实验模型存在一些局限性。
