PDF(Pubmed)
Abstract：
Excessive cytosolic calcium accumulation contributes to muscle degeneration in Duchenne muscular dystrophy (DMD). Sarco/endoplasmic reticulum calcium ATPase (SERCA) is a sarcoplasmic reticulum (SR) calcium pump that actively transports calcium from the cytosol into the SR. We previously showed that adeno-associated virus (AAV)-mediated SERCA2a therapy reduced cytosolic calcium overload and improved muscle and heart function in the murine DMD model. Here, we tested whether AAV SERCA2a therapy could ameliorate muscle disease in the canine DMD model. 7.83 × 1013 vector genome particles of the AAV vector were injected into the extensor carpi ulnaris (ECU) muscles of four juvenile affected dogs. Contralateral ECU muscles received excipient. Three months later, we observed widespread transgene expression and significantly increased SERCA2a levels in the AAV-injected muscles. Treatment improved SR calcium uptake, significantly reduced calpain activity, significantly improved contractile kinetics, and significantly enhanced resistance to eccentric contraction-induced force loss. Nonetheless, muscle histology was not improved. To evaluate the safety of AAV SERCA2a therapy, we delivered the vector to the ECU muscle of adult normal dogs. We achieved strong transgene expression without altering muscle histology and function. Our results suggest that AAV SERCA2a therapy has the potential to improve muscle performance in a dystrophic large mammal.
摘要：
在Duchenne型肌营养不良症(DMD)中,过量的胞浆钙积累有助于肌肉变性。Sarco/内质网钙ATP酶（SERCA）是一种肌浆网（SR）钙泵，可将钙从细胞质中主动转运到SR中。我们先前表明，腺相关病毒（AAV）介导的SERCA2a治疗减少了鼠DMD模型中的胞浆钙超载并改善了肌肉和心脏功能。这里,我们测试了AAVSERCA2a治疗是否可以改善犬DMD模型中的肌肉疾病。将AAV载体的7.83×1013载体基因组颗粒注射到四只幼年受影响的狗的尺骨伸肌（ECU）肌肉中。对侧ECU肌肉接受赋形剂。三个月后,我们观察到AAV注射肌肉中广泛的转基因表达和SERCA2a水平显着增加。治疗改善SR钙摄取，显著降低钙蛋白酶活性，显著改善收缩动力学，并显着增强了对偏心收缩引起的力损失的抵抗力。尽管如此，肌肉组织学没有改善。为了评估AAVSERCA2a治疗的安全性，我们将载体传递到成年正常狗的ECU肌肉。我们在不改变肌肉组织学和功能的情况下实现了强转基因表达。我们的结果表明，AAVSERCA2a疗法有可能改善营养不良的大型哺乳动物的肌肉性能。
