Poukalov Kiril K, Valero M Carmen, Muscato Derek R, Adams Leanne M, Chun Heejae, Lee Young Il, Andrade Nadja S, Zeier Zane, Sweeney H Lee, Wang Eric T
Department of Molecular Genetics & Microbiology, University of Florida.
Center for NeuroGenetics, University of Florida.
bioRxiv. 2023 Nov 6:2023.11.06.565807. doi: 10.1101/2023.11.06.565807.
Successful CRISPR/Cas9-based gene editing in skeletal muscle is dependent on efficient propagation of Cas9 to all myonuclei in the myofiber. However, nuclear-targeted gene therapy cargos are strongly restricted to their myonuclear domain of origin. By screening nuclear localization signals and nuclear export signals, we identify "Myospreader", a combination of short peptide sequences that promotes myonuclear propagation. Appending Myospreader to Cas9 enhances protein stability and myonuclear propagation in myoblasts and myofibers. AAV-delivered Myospreader dCas9 better inhibits transcription of toxic RNA in a myotonic dystrophy mouse model. Furthermore, Myospreader Cas9 achieves higher rates of gene editing in CRISPR reporter and Duchenne muscular dystrophy mouse models. Myospreader reveals design principles relevant to all nuclear-targeted gene therapies and highlights the importance of the spatial dimension in therapeutic development.
基于CRISPR/Cas9的骨骼肌基因编辑能否成功取决于Cas9能否有效地扩散到肌纤维中的所有肌细胞核。然而，靶向细胞核的基因治疗载体被严格限制在其起源的肌细胞核区域内。通过筛选核定位信号和核输出信号，我们鉴定出了“Myospreader”，这是一种短肽序列的组合，可促进肌细胞核内的扩散。将Myospreader附加到Cas9上可增强其在成肌细胞和肌纤维中的蛋白质稳定性及肌细胞核内的扩散。在强直性肌营养不良小鼠模型中，腺相关病毒递送的Myospreader dCas9能更好地抑制毒性RNA的转录。此外，在CRISPR报告基因和杜氏肌营养不良小鼠模型中，Myospreader Cas9实现了更高的基因编辑效率。Myospreader揭示了与所有靶向细胞核的基因治疗相关的设计原则，并突出了空间维度在治疗开发中的重要性。
