Terrill Jessica R, Grounds Miranda D, Arthur Peter G
The University of Western Australia.
School of Anatomy and Human Biology, the University of Western Australia, Perth, Australia.
PLoS Curr. 2016 Apr 29;8:ecurrents.md.77be6ec30e8caf19529a00417614a072. doi: 10.1371/currents.md.77be6ec30e8caf19529a00417614a072.
The mdx mouse model for the fatal muscle wasting disease Duchenne Muscular Dystrophy (DMD) shows a very mild pathology once growth has ceased, with low levels of myofibre necrosis in adults. However, from about 3 weeks of post-natal age, muscles of juvenile mdx mice undergo an acute bout of severe necrosis and inflammation: this subsequently decreases and stabilises to lower adult levels by about 6 weeks of age. Prior to the onset of this severe dystropathology, we have shown that mdx mice are deficient in the amino acid taurine (potentially due to weaning), and we propose that this exacerbates myofibre necrosis and inflammation in juvenile mdx mice.
The purpose of this study was to increase taurine availability to pre-weaned juvenile mdx mice (from 14 days of age), to evaluate the impact on levels of myofibre necrosis and inflammation (at 22 days) during the acute period of severe dystropathology.
Untreated 22 day old mdx muscle was not deficient in taurine, with similar levels to normal C57 control muscle. However taurine treatment, which increased the taurine content of young dystrophic muscle (by 40%), greatly reduced myofibre necrosis (by 75%) and prevented significant increases in 3 markers of inflammation.
Taurine was very effective at preventing the acute phase of muscle damage that normally results in myofibre necrosis and inflammation in juvenile mdx mice, supporting continued research into the use of taurine as a therapeutic intervention for protecting growing muscles of young DMD boys.
用于致命性肌肉萎缩疾病杜氏肌营养不良症(DMD)的mdx小鼠模型在生长停止后病理表现非常轻微,成年小鼠肌纤维坏死水平较低。然而,从出生后约3周起,幼年mdx小鼠的肌肉会经历一阵严重的坏死和炎症:随后这种情况会减少并在约6周龄时稳定至较低的成年水平。在这种严重肌营养不良病理发生之前,我们已经表明mdx小鼠缺乏氨基酸牛磺酸(可能是由于断奶),并且我们提出这会加剧幼年mdx小鼠的肌纤维坏死和炎症。
本研究的目的是提高断奶前幼年mdx小鼠(从14日龄开始)的牛磺酸供应量,以评估在严重肌营养不良病理急性期(22日龄时)对肌纤维坏死和炎症水平的影响。
未经治疗的22日龄mdx肌肉并不缺乏牛磺酸,其水平与正常C57对照肌肉相似。然而,牛磺酸治疗增加了幼年营养不良肌肉中的牛磺酸含量(增加了40%),大大减少了肌纤维坏死(减少了75%),并防止了三种炎症标志物的显著增加。
牛磺酸在预防通常导致幼年mdx小鼠肌纤维坏死和炎症的肌肉损伤急性期方面非常有效,支持继续研究将牛磺酸用作保护年轻DMD男孩正在生长的肌肉的治疗干预措施。