目的:美国国家航空航天局(NASA)为期70天的卧床休息研究期间的运动训练有效地抵消了有氧能力的下降,肌肉质量,力量,和耐力。我们的目的是描述参与者在有和没有运动对策的卧床休息第64天的基因组反应。
方法:将22名健康年轻男性随机分为三组:1)仅卧床休息(n=7),2)卧床休息+有氧(6d/wk)和标准设备阻力训练(3d/wk)(n=7),3)卧床休息+使用飞轮装置的有氧和阻力训练(n=8)。使用GeneSpringGX14.9.1分析VL基因和microRNA微阵列。
结果:卧床休息显著改变了三个研究组中至少一个的2113个注释基因的表达(倍数变化(FC)>1.2;P<0.05)。交互作用分析表明,运动减弱了511个注释基因的卧床休息效应(FC1.2,P<0.05)。只在床上休息组,观察到基因的主要下调,而在两个运动组中,这种作用显着减弱或逆转,两种运动方式之间没有显着差异。富集分析确定了功能类别和基因途径,其中许多与线粒体有关。此外,卧床休息显著改变了35个microRNAs的表达(FC>1.2,P<0.05),三组间差异无统计学意义。已知有12种调节一些线粒体相关基因,这些基因在卧床休息后发生了变化。
结论:线粒体基因表达是长期卧床反应的重要组成部分。虽然运动减弱了许多基因下调的FC,它并没有完全抵消所有的分子后果。
OBJECTIVE: Exercise training during the National Aeronautics and Space Administration 70-d bed rest study effectively counteracted the decline in aerobic capacity, muscle mass, strength, and endurance. We aimed to characterize the genomic response of the participants\' vastus lateralis on day 64 of bed rest with and without exercise countermeasures.
METHODS: Twenty-two healthy young males were randomized into three groups: 1) bed rest only ( n = 7), 2) bed rest + aerobic (6 d·wk -1 ) and resistance training (3 d·wk -1 ) on standard equipment ( n = 7), and 3) bed rest + aerobic and resistance training using a flywheel device ( n = 8). The vastus lateralis gene and microRNA microarrays were analyzed using GeneSpring GX 14.9.1 (Agilent Technologies, Palo Alto, CA).
RESULTS: Bed rest significantly altered the expression of 2113 annotated genes in at least one out of the three study groups (fold change (FC) > 1.2; P < 0.05). Interaction analysis revealed that exercise attenuated the bed rest effect of 511 annotated genes (FC = 1.2, P < 0.05). In the bed rest only group, a predominant downregulation of genes was observed, whereas in the two exercise groups, there was a notable attenuation or reversal of this effect, with no significant differences between the two exercise modalities. Enrichment analysis identified functional categories and gene pathways, many of them related to the mitochondria. In addition, bed rest significantly altered the expression of 35 microRNAs (FC > 1.2, P < 0.05) with no difference between the three groups. Twelve are known to regulate some of the mitochondrial-related genes that were altered following bed rest.
CONCLUSIONS: Mitochondrial gene expression was a significant component of the molecular response to long-term bed rest. Although exercise attenuated the FC in the downregulation of many genes, it did not completely counteract all the molecular consequences.