Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA.
Department of Health and Kinesiology, Texas A&M University College Station, College Station, TX, USA.
Physiol Rep. 2020 Nov;8(21):e14605. doi: 10.14814/phy2.14605.
In this pilot work, we selected two inbred strains that respond well to endurance training (ET) (FVB/NJ, and SJL/J strains), and two strains that respond poorly (BALB/cByJ and NZW/LacJ), to determine the effect of a standardized ET treadmill program on mitochondrial and nuclear DNA (nucDNA) integrity, and mitochondrial DNA (mtDNA) copy number. DNA was isolated from plantaris muscles (n = 37) and a gene-specific quantitative PCR-based assay was used to measure DNA lesions and mtDNA copy number. Mean mtDNA lesions were not different within strains in the sedentary or exercise-trained states. However, mtDNA lesions were significantly higher in trained low-responding NZW/LacJ mice (0.24 ± 0.06 mtDNA lesions/10 Kb) compared to high-responding strains (mtDNA lesions/10 Kb: FVB/NJ = 0.11 ± 0.01, p = .049; SJL/J = 0.04 ± 0.02; p = .003). ET did not alter mean mtDNA copy numbers for any strain, although both sedentary and trained FVB/NJ mice had significantly higher mtDNA copies (99,890 ± 4,884 mtDNA copies) compared to low-responding strains (mtDNA copies: BALB/cByJ = 69,744 ± 4,675; NZW/LacJ = 65,687 ± 5,180; p < .001). ET did not change nucDNA lesions for any strain, however, SJL/J had the lowest mean nucDNA lesions (3.5 ± 0.14 nucDNA lesions/6.5 Kb) compared to all other strains (nucDNA lesions/6.5 Kb: FVB/NJ = 4.4 ± 0.11; BALB/cByJ = 4.7 ± 0.09; NZW/LacJ = 4.4 ± 0.11; p < .0001). Our results demonstrate strain differences in plantaris muscle mtDNA lesions in ET mice and, independent of condition, differences in mean mtDNA copy and nucDNA lesions between strains.
在这项初步研究中，我们选择了两种对耐力训练反应良好的近交系（FVB/NJ 和 SJL/J 品系）和两种反应较差的品系（BALB/cByJ 和 NZW/LacJ），以确定标准化耐力训练方案对线粒体和核 DNA（nucDNA）完整性以及线粒体 DNA（mtDNA）拷贝数的影响。从比目鱼肌中分离出 DNA（n=37），并使用基因特异性定量 PCR 测定法测量 DNA 损伤和 mtDNA 拷贝数。在安静或运动训练状态下，各品系之间的 mtDNA 损伤平均值没有差异。然而，在高反应性品系中，训练有素的低反应性 NZW/LacJ 小鼠的 mtDNA 损伤明显更高（0.24±0.06 mtDNA 损伤/10 Kb），与高反应性品系相比（mtDNA 损伤/10 Kb：FVB/NJ=0.11±0.01，p=0.049；SJL/J=0.04±0.02；p=0.003）。耐力训练并没有改变任何品系的平均 mtDNA 拷贝数，尽管安静和训练有素的 FVB/NJ 小鼠的 mtDNA 拷贝数（99890±4884 mtDNA 拷贝）明显高于低反应性品系（mtDNA 拷贝：BALB/cByJ=69744±4675；NZW/LacJ=65687±5180；p<0.001）。耐力训练没有改变任何品系的 nucDNA 损伤，但 SJL/J 的 nucDNA 损伤平均值最低（3.5±0.14 nucDNA 损伤/6.5 Kb），与所有其他品系相比（nucDNA 损伤/6.5 Kb：FVB/NJ=4.4±0.11；BALB/cByJ=4.7±0.09；NZW/LacJ=4.4±0.11；p<0.0001）。我们的结果表明，在耐力训练的小鼠中，比目鱼肌 mtDNA 损伤存在品系差异，并且独立于条件，mtDNA 拷贝和 nucDNA 损伤在各品系之间存在差异。
