School of Kinesiology, Auburn University, Auburn, AL, USA.
Department of Nutrition, Dietetics and Hospitality Management, Auburn University, Auburn, AL, USA.
Physiol Rep. 2020 Aug;8(15):e14526. doi: 10.14814/phy2.14526.
We investigated the acute and chronic effects of resistance training (RT) on skeletal muscle markers of mitochondrial content and remodeling in older, untrained adults. Sixteen participants (n = 6 males, n = 10 females; age = 59 ± 4 years) completed 10 weeks of full-body RT (2 day/week). Muscle biopsies from the vastus lateralis were obtained prior to RT (Pre), 24 hr following the first training session (Acute), and 72 hr following the last training session (Chronic). Protein levels of mitochondrial electron transport chain complexes I-V (+39 to +180%, p ≤ .020) and markers of mitochondrial fusion Mfn1 (+90%, p = .003), Mfn2 (+110%, p < .001), and Opa1 (+261%, p = .004) increased following chronic RT. Drp1 protein levels also increased (+134%, p = .038), while Fis1 protein levels did not significantly change (-5%, p = .584) following chronic RT. Interestingly, protein markers of mitochondrial biogenesis (i.e., PGC-1α, TFAM, and NRF1) or mitophagy (i.e., Pink1 and Parkin) were not significantly altered (p > .050) after 10 weeks of RT. In summary, chronic RT promoted increases in content of electron transport chain proteins (i.e., increased protein levels of all five OXPHOS complexes) and increase in the levels of proteins related to mitochondrial dynamics (i.e., increase in fusion protein markers) in skeletal muscle of older adults. These results suggest that chronic RT could be a useful strategy to increase mitochondrial protein content in older individuals.
我们研究了抗阻训练（RT）对未经训练的老年个体骨骼肌中线粒体含量和重塑的急性和慢性影响。16 名参与者（n=6 名男性，n=10 名女性；年龄=59±4 岁）完成了 10 周的全身 RT（每周 2 天）。在 RT 之前（Pre）、第一次训练课后 24 小时（急性）和最后一次训练课后 72 小时（慢性），从股外侧肌获取肌肉活检。线粒体电子传递链复合物 I-V 的蛋白水平（+39 至+180%，p≤.020）和线粒体融合标志物 Mfn1（+90%，p=.003）、Mfn2（+110%，p<.001）和 Opa1（+261%，p=.004）在慢性 RT 后增加。Drp1 蛋白水平也增加（+134%，p=.038），而 Fis1 蛋白水平在慢性 RT 后没有显著变化（-5%，p=.584）。有趣的是，线粒体生物发生的蛋白标志物（即 PGC-1α、TFAM 和 NRF1）或线粒体自噬的蛋白标志物（即 Pink1 和 Parkin）在 10 周 RT 后没有显著改变（p>.050）。总之，慢性 RT 促进了电子传递链蛋白含量的增加（即 OXPHOS 复合体的所有五个蛋白水平均增加）以及与线粒体动力学相关的蛋白水平的增加（即融合蛋白标志物增加），这表明慢性 RT 可能是增加老年人线粒体蛋白含量的一种有用策略。
