Skeletal muscle satellite cells are located at a closer proximity to capillaries in healthy young compared with older men.
Skeletal muscle satellite cells are located at a closer proximity to capillaries in healthy young compared with older men.
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DOI：
10.1002/jcsm.12105
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发表时间：
2016-12
期刊：
影响因子：
--
通讯作者：
Parise G
中科院分区：
文献类型：
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作者：
Nederveen JP;Joanisse S;Snijders T;Ivankovic V;Baker SK;Phillips SM;Parise G
骨骼肌卫星细胞（SC）在维持肌肉纤维、对运动的适应性反应中起着重要作用，并且SC的下降与年龄有关。SC与肌肉纤维毛细血管之间存在空间关系。在本研究中，我们旨在探讨年龄是否对SC和肌肉纤维毛细血管的空间关系有影响。其次，我们确定了这种空间关系是否会随着单次阻力运动而改变。对未训练的年轻男性（YM， 24±3岁，n = 23）和老年男性（OM， 67±4岁，n = 22）静息时进行股外侧肌活检。YM的一个子集（n = 9）进行了单次阻力运动，在运动恢复后24和72小时进行了额外的肌肉活检。使用肌肉横截面免疫荧光显微镜评估骨骼肌纤维毛细血管化、SC含量和激活状态。与OM相比，YM的II型肌纤维SC和毛细血管含量显著降低（P < 0.05）。此外，与YM相比，OM中II型肌纤维SC距离最近的毛细血管的距离更大（分别为21.6±1.3µm比17.0±0.8µm, P < 0.05）。在单次运动后，我们观察到SC数量和激活状态显著增加（P < 0.05）。此外，激活SC与静止SC更靠近毛细血管（P < 0.05）。我们证明，与YM相比，OM的毛细血管和II型纤维相关的SC之间的距离更大。此外，在单次运动后，静止SC比活跃SC离毛细血管远得多。我们的数据暗示了肌肉如何适应运动，以及衰老如何影响这种适应。
Skeletal muscle satellite cells (SC) are instrumental in maintenance of muscle fibres, the adaptive responses to exercise, and there is an age‐related decline in SC. A spatial relationship exists between SC and muscle fibre capillaries. In the present study, we aimed to investigate whether chronologic age has an impact on the spatial relationship between SC and muscle fibre capillaries. Secondly, we determined whether this spatial relationship changes in response to a single session of resistance exercise. Muscle biopsies were obtained from the vastus lateralis of previously untrained young men (YM, 24 ± 3 years; n = 23) and older men (OM, 67 ± 4 years; n = 22) at rest. A subset of YM (n = 9) performed a single bout of resistance exercise, where additional muscle biopsies taken at 24 and 72 h post‐exercise recovery. Skeletal muscle fibre capillarization, SC content, and activation status were assessed using immunofluorescent microscopy of muscle cross sections. Type II muscle fibre SC and capillary content was significantly lower in the YM compared with OM (P < 0.05). Furthermore, type II muscle fibre SC were located at a greater distance from the nearest capillary in OM compared with YM (21.6 ± 1.3 vs. 17.0 ± 0.8 µm, respectively; P < 0.05). In response to a single bout of exercise, we observed a significant increase in SC number and activation status (P < 0.05). In addition, activated vs. quiescent SC were situated closer (P < 0.05) to capillaries. We demonstrate that there is a greater distance between capillaries and type II fibre‐associated SC in OM as compared with YM. Furthermore, quiescent SC are located significantly further away from capillaries than active SC after single bout of exercise. Our data have implications for how muscle adapts to exercise and how aging may affect such adaptations.