Skeletal muscle fiber type conversion during the repair of mouse soleus: Potential implications for muscle healing after injury
Skeletal muscle fiber type conversion during the repair of mouse soleus: Potential implications for muscle healing after injury
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DOI：
10.1002/jor.20451
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发表时间：
2007-11-01
影响因子：
2.8
通讯作者：
Huard, Johnny
中科院分区：
文献类型：
--
作者：
Matsuura, Tetsuya;Li, Yong;Huard, Johnny
我们使用心脏毒素损伤的小鼠模型来检查肌肉修复过程中的纤维类型转换。我们在受伤后 2、4、8 和 12 周评估了 37 只野生型小鼠的比目鱼肌。我们还使用针对快肌球蛋白重链和慢肌球蛋白重链的抗体（fMHC 和 sMHC）将肌纤维分为三类：快型、慢型和混合（混合）型肌纤维（同时表达 fMHC 和 sMHC 的肌纤维）。我们的结果显示，在修复过程中，慢型肌纤维的百分比增加，快速型肌纤维的百分比减少。混合型肌纤维的百分比在受伤后 2 周增加，然后在接下来的 6 周内逐渐下降。同样，我们对中心核肌纤维的分析表明，慢速型肌纤维的百分比增加，而快速型和混合型肌纤维的百分比下降。我们还研究了肌纤维类型转换与过氧化物酶体增殖物激活受体-gamma coactivator-1 α (PGC-1 α) 之间的关系。注射心脏毒素后，在再生肌纤维的细胞核和细胞质中表达的 PGC-1 α 蛋白和 sMHC 蛋白的表达随着时间的推移而增加，但我们在肌肉修复过程中观察到再生肌纤维中 fMHC 蛋白的表达没有显着差异。 PGC-1 α 阳性肌纤维在修复过程中经历了快速到缓慢的肌纤维类型转换。这些结果表明 PGC-1 α 有助于肌肉损伤后肌纤维类型的转换，并且这种现象可能会影响受伤肌肉的恢复。 (C) 2007 年骨科研究学会。由 Wiley 期刊公司出版
We used a mouse model of cardiotoxin injury to examine fiber type conversion during muscle repair. We evaluated the soleus muscles of 37 wild-type mice at 2, 4, 8, and 12 weeks after injury. We also used antibodies (fMHC and sMHC) against fast and slow myosin heavy chain to classify the myofibers into three categories: fast-, slow-, and mixed (hybrid)-type myofibers (myofibers expressing both fMHC and sMHC). Our results revealed an increase in the percentage of slow-type myofibers and a decrease in the percentage of fast-type myofibers during the repair process. The percentage of hybrid-type myofibers increased 2 weeks after injury, then gradually decreased over the following 6 weeks. Similarly, our analysis of centronucleated myofibers showed an increase in the percentage of slow-type myofibers and decreases in the percentages of fast- and hybrid-type myofibers. We also investigated the relationship between myofiber type conversion and peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha). The expression of both PGC-1 alpha protein, which is expressed in both the nucleus and the cytoplasm of regenerating myofibers, and sMHC protein increased with time after cardiotoxin injection, but we observed no significant differential expression of fMHC protein in regenerating muscle fibers during muscle repair. PGC-1 alpha-positive myofibers underwent fast to slow myofiber type conversion during the repair process. These results suggest that PGC-1 alpha contributes to myofiber type conversion after muscle injury and that this phenomenon could influence the recovery of the injured muscle. (C) 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.