Krajnak Kristine, Waugh Stacey, Miller Roger, Baker Brent, Geronilla Kenneth, Alway Stephen E, Cutlip Robert G
Engineering and Controls Technology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS 2027, Morgantown, West Virginia 26505, USA.
Muscle Nerve. 2006 Dec;34(6):720-30. doi: 10.1002/mus.20656.
Aging impairs the ability of muscle to adapt to exercise or injury. The goal of this study was to determine whether age-related changes in muscle adaptability could be the result of satellite cell apoptosis. Ten days after exposure to an injury protocol, estimates of edema in the exposed tibialis anterior muscles were higher in old (30 months) than young (3 months) rats, and isometric force levels were lower in old rats. Both young and old rats displayed an increase in MyoD labeling in the exposed muscle, indicating that injury induced satellite-cell activation. However, there were more MyoD-labeled cells that coexpressed the proapoptotic factor, Bax, in old than in young rats, suggesting that decrements in muscle recovery may be associated with an increase in satellite-cell apoptosis. Based on these findings we conclude that reducing satellite-cell apoptosis in aged animals may improve muscle recovery after injury.
衰老会损害肌肉适应运动或损伤的能力。本研究的目的是确定肌肉适应性方面与年龄相关的变化是否可能是卫星细胞凋亡的结果。在接受损伤处理方案10天后，老龄（30个月）大鼠暴露的胫前肌中的水肿估计值高于幼龄（3个月）大鼠，且老龄大鼠的等长力水平较低。幼龄和老龄大鼠在暴露的肌肉中MyoD标记均增加，表明损伤诱导了卫星细胞激活。然而，与幼龄大鼠相比，老龄大鼠中同时共表达促凋亡因子Bax的MyoD标记细胞更多，这表明肌肉恢复能力的下降可能与卫星细胞凋亡增加有关。基于这些发现，我们得出结论，减少老龄动物的卫星细胞凋亡可能会改善损伤后的肌肉恢复。
