Physical Training Modulates Structural and Functional Features of Cell Nuclei in Type II Myofibers of Old Mice
Physical Training Modulates Structural and Functional Features of Cell Nuclei in Type II Myofibers of Old Mice
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DOI：
10.1089/rej.2011.1175
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发表时间：
2011-10-01
影响因子：
2.6
通讯作者：
Zancanaro, Carlo
中科院分区：
文献类型：
--
作者：
Malatesta, Manuela;Fattoretti, Patrizia;Zancanaro, Carlo
衰老与肌肉质量、力量和功能的进行性丧失有关，这种情况被称为石棺减少，这是老年人身体残疾的一个重要风险因素。导致骨质疏松症的机制在很大程度上仍不清楚，目前还没有特效的治疗方法来对抗其发生或进展。许多研究强调了体育锻炼作为预防/限制年龄相关性肌肉质量下降的有效方法的重要性。本研究用超微结构细胞化学方法研究了运动对老年小鼠股四头肌和腓肠肌中前信使核糖核酸通路的影响：以成人为对照，比较了运动和久坐不动的老年小鼠股四头肌和腓肠肌中II型纤维的肌核和卫星细胞核的结构和原位分子特征。我们的结果表明，在老年小鼠的肌核中，运动刺激了前mRNA的转录、剪接并输出到细胞质，可能会增加肌肉蛋白质的周转。在卫星细胞中，体育锻炼的效果似乎仅限于重新激活参与转录和剪接设备的某些因子，而不增加RNA的产生，可能使这些静止的细胞对激活的刺激更有反应。
Aging is associated with a progressive loss of muscle mass, strength, and function, a condition known as sarcopenia, which represents an important risk factor for physical disability in elderly. The mechanisms leading to sarcopenia are still largely unknown, and no specific therapy is presently available to counteract its onset or progress. Many studies have stressed the importance of physical exercise as an effective approach to prevent/limit the age-related muscle mass loss. This study investigated the effects of physical training on pre-mRNA pathways in quadriceps and gastrocnemius muscles of old mice by ultrastructural cytochemistry: Structural and in situ molecular features of myonuclei and satellite cell nuclei of type II fibers were compared in exercised versus sedentary old mice, using adult individuals as control. Our results demonstrated that in myonuclei of old mice physical exercise stimulates pre-mRNA transcription, splicing, and export to the cytoplasm, likely increasing muscle protein turnover. In satellite cells, the effect of physical exercise seems to be limited to the reactivation of some factors involved in the transcriptional and splicing apparatus without increasing RNA production, probably making these quiescent cells more responsive to activating stimuli.