目的研究后肢尾吊模拟失重效应对大鼠比目鱼肌microRNA(miRNA)表达的影响,为失重性肌萎缩发生发展机制提供实验证据。方法 60只SD大鼠,随机分为尾吊组和对照组,分别在尾吊第7天、14天、28天分离SD大鼠比目鱼肌,提取miRNA和总RNA,进行miRNA表达谱分析,并运用生物信息学和Real-time PCR方法验证相关miRNA及其靶基因变化结果。结果后肢尾吊导致比目鱼肌显著萎缩,质量下降。表达谱分析显示尾吊7 d和14 d差异表达miRNA分别有18和13个;PCR结果显示促进肌分化的miR-214持续下调,最高达42%(P<0.05),促肌再生miR-206无显著变化。抑制蛋白降解的miR-486-5p在尾吊初期下调,而抑制IGF-1的miR-320家族在后期下调,均超过50%,并具有显著性差异。共同靶基因whyz表达上调与多数miRNA下调的结果一致。结论 miR-214、miR-486-5p和miR-320在模拟失重诱导肌萎缩过程中表达显著改变。 Objective To investigate the effects of simulated weightlessness effect of tail hindlimb on the expression of miRNA in soleus muscle of rats and provide experimental evidence for the mechanism of development of weightless muscle atrophy. Methods Sixty Sprague-Dawley rats were randomly divided into tail-suspending group and control group. SD rats were isolated from the soleus muscle on the 7th, 14th and 28th day after tail suspension, and miRNA and total RNA were extracted for miRNA expression profiling analysis. Bioinformatics and Real-time PCR methods were used to validate the results of miRNAs and their target genes. Results tail hindlimb caused a significant contraction of the soleus muscle, the quality decline. Expression profiling showed that there were 18 and 13 differentially expressed miRNAs on the 7th day and 14th day respectively. The results of PCR showed that miR-214 was down-regulated up to 42% (P <0.05) No significant change. MiR-486-5p, which inhibits protein degradation, was downregulated at the beginning of tail tails, while the miR-320 family, which inhibits IGF-1, was down-regulated by more than 50% in the later period with significant differences. The upregulation of the common target gene whyz is consistent with the down-regulation of most miRNAs. Conclusion The expression of miR-214, miR-486-5p and miR-320 in the process of simulated weightlessness-induced muscle atrophy significantly changed.