BACKGROUND MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that regulate gene expression. There is increasing evidence that some miRNAs are involved in the pathology of diabetes mellitus (DM) and its complications. We hypothesized that the functions of certain miRNAs and the changes in their patterns of expression may contribute to the pathogenesis of impaired fractures due to DM. METHODS In this study, 108 male Sprague-Dawley rats were divided into DM and control groups. DM rats were created by a single intravenous injection of streptozotocin. Closed transverse femoral shaft fractures were created in both groups. On post-fracture days 5, 7, 11, 14, 21, and 28, miRNA was extracted from the newly generated tissue at the fracture site. Microarray analysis was conducted with miRNA samples from each group on post-fracture days 5 and 11. The microarray findings were validated by real-time polymerase chain reaction (PCR) analysis at each time point. RESULTS Microarray analysis revealed that, on days 5 and 11, 368 and 207 miRNAs, respectively, were upregulated in the DM group, compared with the control group. The top four miRNAs on day 5 were miR-339-3p, miR451-5p, miR-532-5p, and miR-551b-3p. The top four miRNAs on day 11 were miR-221-3p, miR376a-3p, miR-379-3p, and miR-379-5p. Among these miRNAs, miR-221-3p, miR-339-3p, miR-376a-3p, miR-379-5p, and miR-451-5p were validated by real-time PCR analysis. Furthermore, PCR analysis revealed that these five miRNAs were differentially expressed with dynamic expression patterns during fracture healing in the DM group, compared with the control group. CONCLUSIONS Our findings will aid in understanding the pathology of impaired fracture healing in DM and may support the development of molecular therapies using miRNAs for the treatment of impaired fracture healing in patients with DM.

中文翻译：

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糖尿病大鼠骨折愈合过程中微小RNA谱的改变。

背景技术微小RNA（miRNA）是一类调节基因表达的小的非编码RNA分子。越来越多的证据表明，某些miRNA参与了糖尿病（DM）的病理及其并发症。我们假设某些miRNA的功能及其表达模式的变化可能与DM导致的受损骨折的发病机理有关。方法在本研究中，将108只雄性Sprague-Dawley大鼠分为DM组和对照组。通过单次静脉内注射链脲佐菌素产生DM大鼠。两组均发生闭合性股骨干横断骨折。在骨折后第5、7、11、14、21和28天，从骨折部位新产生的组织中提取了miRNA。在骨折后第5天和第11天对来自各组的miRNA样品进行微阵列分析。通过实时聚合酶链反应（PCR）分析在每个时间点验证微阵列的发现。结果微阵列分析显示，与对照组相比，DM组在第5天和第11天分别有368和207个miRNA上调。第5天排名前四的miRNA是miR-339-3p，miR451-5p，miR-532-5p和miR-551b-3p。第11天的前四个miRNA是miR-221-3p，miR376a-3p，miR-379-3p和miR-379-5p。在这些miRNA中，通过实时PCR分析验证了miR-221-3p，miR-339-3p，miR-376a-3p，miR-379-5p和miR-451-5p。此外，PCR分析显示，在DM组的骨折愈合过程中，这五个miRNA以动态表达方式差异表达，与对照组相比。结论我们的发现将有助于理解DM骨折愈合受损的病理学，并可能支持使用miRNAs治疗DM骨折愈合受损的分子疗法。