Effects of voluntary wheel running on mitochondrial content and dynamics in rat skeletal muscle
Effects of voluntary wheel running on mitochondrial content and dynamics in rat skeletal muscle
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DOI：
10.1007/s10974-020-09580-9
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发表时间：
2020-05-21
影响因子：
2.7
通讯作者：
Murphy, Robyn M.
中科院分区：
文献类型：
--
作者：
Frankish, Barnaby P.;Najdovska, Petra;Murphy, Robyn M.
该研究报告了在大鼠骨骼肌中，与主要糖酵解的趾长伸肌（EDL）肌肉相比，氧化比目鱼肌（SOL）中特异性负责线粒体动力学的蛋白质，即线粒体融合蛋白-2（MFN 2）和线粒体动力学蛋白49（MiD 49）更高（p < 0.05），但在视神经萎缩1（OPA 1; p = 0.06）中未见。线粒体含量的标志物，复合物I组分，NADH：泛醌氧化还原酶亚基A9（NDUFA 9）和复合物IV蛋白，细胞色素C氧化酶亚基IV（COXIV; p < 0.05）在SOL中也高于EDL肌肉;然而，如使用柠檬酸合酶测定所测量的，肌肉之间的线粒体含量没有差异（p > 0.05）。SOL和EDL肌肉在年龄匹配的久坐大鼠之间进行比较，这些大鼠单独饲养（RUN）或没有（SED）自由接近转轮12周，并且通过NDUFA 9和COXIV蛋白的丰度以及柠檬酸合酶活性在任一肌肉中检查，线粒体含量没有变化（p > 0.05）。与SED动物相比，MiD 49和OPA 1在EDL或SOL肌肉中没有差异，并且MFN 2在来自RUN大鼠的SOL肌肉中更高（p < 0.05）。总的来说，这些研究结果表明，自愿轮运行是一个不够的刺激，导致在一个显着更高的丰度的大多数标志物的线粒体内容或动态，它很可能是一个更大的刺激，如增加阻力的车轮或增加运行量，通过使用跑步机，需要线粒体适应大鼠骨骼肌。
This study reports that in rat skeletal muscle the proteins specifically responsible for mitochondrial dynamics, mitofusin-2 (MFN2) and mitochondrial dynamics protein 49 (MiD49), are higher (p < 0.05) in oxidative soleus (SOL) muscle compared with predominantly glycolytic extensor digitorum longus (EDL) muscle, but not seen for optic atrophy 1 (OPA1; p = 0.06). Markers of mitochondrial content, complex I component, NADH:Ubiquinone oxidoreductase subunit A9 (NDUFA9) and complex IV protein, cytochrome C oxidase subunit IV (COXIV; p < 0.05) were also higher in SOL compared with EDL muscle; however, there was no difference in mitochondrial content between muscles, as measured using a citrate synthase assay (p > 0.05). SOL and EDL muscles were compared between age-matched sedentary rats that were housed individually with (RUN) or without (SED) free-access to a running wheel for 12 weeks and showed no change in mitochondrial content, as examined by the abundances of NDUFA9 and COXIV proteins, as well as citrate synthase activity, in either muscle (p > 0.05). Compared to SED animals, MiD49 and OPA1 were not different in either EDL or SOL muscles, and MFN2 was higher in SOL muscles from RUN rats (p < 0.05). Overall, these findings reveal that voluntary wheel running is an insufficient stimulus to result in a significantly higher abundance of most markers of mitochondrial content or dynamics, and it is likely that a greater stimulus, such as either adding resistance to the wheel or an increase in running volume by using a treadmill, is required for mitochondrial adaptation in rat skeletal muscle.