Clinical Translation Unit (CTU), Tulane University, New Orleans, USA.
Agency for Science, Technology & Research (A*STAR), Singapore Bioimaging Consortium (SBIC), Singapore, Singapore.
J Transl Med. 2021 Feb 16;19(1):71. doi: 10.1186/s12967-021-02737-1.
Skeletal muscle aging is associated with a decline in motor function and loss of muscle mass- a condition known as sarcopenia. The underlying mechanisms that drive this pathology are associated with a failure in energy generation in skeletal muscle, either from age-related decline in mitochondrial function, or from disuse. To an extent, lifelong exercise is efficacious in preserving the energetic properties of skeletal muscle and thus may delay the onset of sarcopenia. This review discusses the cellular and molecular changes in skeletal muscle mitochondria during the aging process and how different exercise modalities work to reverse these changes. A key factor that will be described is the efficiency of mitochondrial coupling-ATP production relative to O uptake in myocytes and how that efficiency is a main driver for age-associated decline in skeletal muscle function. With that, we postulate the most effective exercise modality and protocol for reversing the molecular hallmarks of skeletal muscle aging and staving off sarcopenia. Two other concepts pertinent to mitochondrial efficiency in exercise-trained skeletal muscle will be integrated in this review, including- mitophagy, the removal of dysfunctional mitochondrial via autophagy, as well as the implications of muscle fiber type changes with sarcopenia on mitochondrial function.
骨骼肌衰老与运动功能下降和肌肉质量丧失有关，这种情况被称为肌肉减少症。导致这种病理的潜在机制与骨骼肌能量产生的失败有关，要么是由于线粒体功能随年龄的增长而下降，要么是由于不活动。在某种程度上，终生运动对于保持骨骼肌的能量特性是有效的，因此可能会延迟肌肉减少症的发生。这篇综述讨论了骨骼肌线粒体在衰老过程中的细胞和分子变化，以及不同的运动方式如何逆转这些变化。将描述的一个关键因素是肌细胞中线粒体偶联的效率-相对于 O 摄取的 ATP 产生，以及这种效率如何成为与年龄相关的骨骼肌功能下降的主要驱动因素。有鉴于此，我们推测最有效的运动方式和方案来逆转骨骼肌衰老的分子特征并延缓肌肉减少症的发生。与运动训练骨骼肌中线粒体效率相关的另外两个概念也将纳入本综述，包括-自噬通过自噬清除功能失调的线粒体，以及肌肉纤维类型变化对线粒体功能的影响。
