Research Center for Genetic Medicine, Children's National Hospital, 111 Michigan Ave NW, Washington, DC 20010, USA.
Department of Genomics and Precision Medicine, The George Washington University School of Medicine and Health Science, 111 Michigan Ave NW, Washington, DC 20010, USA.
Int J Mol Sci. 2020 Aug 4;21(15):5575. doi: 10.3390/ijms21155575.
Deficits in plasma membrane repair have been identified in dysferlinopathy and Duchenne Muscular Dystrophy, and contribute to progressive myopathy. Although Facioscapulohumeral Muscular Dystrophy (FSHD) shares clinicopathological features with these muscular dystrophies, it is unknown if FSHD is characterized by plasma membrane repair deficits. Therefore, we exposed immortalized human FSHD myoblasts, immortalized myoblasts from unaffected siblings, and myofibers from a murine model of FSHD () to focal, pulsed laser ablation of the sarcolemma. Repair kinetics and success were determined from the accumulation of intracellular FM1-43 dye post-injury. We subsequently treated FSHD myoblasts with a -targeting antisense oligonucleotide (AON) to reduce expression, and with the antioxidant Trolox to determine the role of expression and oxidative stress in membrane repair. Compared to unaffected myoblasts, FSHD myoblasts demonstrate poor repair and a greater percentage of cells that failed to repair, which was mitigated by AON and Trolox treatments. Similar repair deficits were identified in myofibers. This is the first study to identify plasma membrane repair deficits in myoblasts from individuals with FSHD, and in myofibers from a murine model of FSHD. Our results suggest that expression and oxidative stress may be important targets for future membrane-repair therapies.
在肌营养不良症和杜氏肌营养不良症中已经发现了质膜修复的缺陷，并导致进行性肌病。虽然面肩肱型肌营养不良症 (FSHD) 与这些肌营养不良症具有临床病理特征，但尚不清楚 FSHD 是否存在质膜修复缺陷。因此，我们使永生的人类 FSHD 成肌细胞、未受影响的兄弟姐妹的永生成肌细胞以及 FSHD 小鼠模型的肌纤维暴露于肌膜的点状、脉冲激光消融。从损伤后细胞内 FM1-43 染料的积累来确定修复动力学和修复成功率。随后，我们用 -靶向反义寡核苷酸 (AON) 处理 FSHD 成肌细胞以降低 表达，并使用抗氧化剂 Trolox 来确定 表达和氧化应激在膜修复中的作用。与未受影响的成肌细胞相比，FSHD 成肌细胞表现出较差的修复能力和更大比例的未能修复的细胞，这可以通过 AON 和 Trolox 处理得到缓解。在 FSHD 小鼠模型的肌纤维中也发现了类似的修复缺陷。这是第一项在 FSHD 个体的成肌细胞和 FSHD 小鼠模型的肌纤维中鉴定质膜修复缺陷的研究。我们的研究结果表明， 表达和氧化应激可能是未来膜修复治疗的重要靶点。
