Center for Cardiovascular Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii.
Bioinformatics Core, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii.
Physiol Genomics. 2020 Aug 1;52(8):358-368. doi: 10.1152/physiolgenomics.00041.2020. Epub 2020 Jul 27.
MicroRNAs (miRNAs) are powerful regulators of protein expression. Many play important roles in cardiac development and disease. While several miRNAs and targets have been well characterized, the abundance of miRNAs and the numerous potential targets for each suggest that the vast majority of these interactions have yet to be described. The goal of this study was to characterize miRNA expression in the mouse heart after coronary artery ligation (LIG) and identify novel mRNA targets altered during the initial response to ischemic stress. We performed small RNA sequencing (RNA-Seq) of ischemic heart tissue 1 day and 3 days after ligation and identified 182 differentially expressed miRNAs. We then selected relevant mRNA targets from all potential targets by correlating miRNA and mRNA expression from a corresponding RNA-Seq data set. From this analysis we chose to focus, as proof of principle, on two miRNAs from the miR-125 family, miR-125a and miR-351, and two of their potential mRNA targets, Xin actin-binding repeat-containing protein 1 () and factor inhibiting hypoxia-inducible factor (). We found miR-125a to be less abundant and XIRP1 more abundant after ligation. In contrast, the related murine miRNA miR-351 was substantially upregulated in response to ischemic injury, and FIH expression correspondingly decreased. Luciferase reporter assays confirmed direct interactions between these miRNAs and targets. In summary, we utilized a correlative analysis strategy combining miRNA and mRNA expression data to identify functional miRNA-mRNA relationships in the heart after ligation. These findings provide insight into the response to ischemic injury and suggest future therapeutic targets.
微小 RNA（miRNA）是蛋白质表达的强大调控因子。许多 miRNA 在心脏发育和疾病中发挥着重要作用。尽管已经对一些 miRNA 和靶标进行了很好的描述，但 miRNA 的丰富度和每个 miRNA 的众多潜在靶标表明，绝大多数这些相互作用尚未被描述。本研究的目的是描述结扎冠状动脉后（LIG）小鼠心脏中 miRNA 的表达，并确定在缺血应激初始反应期间改变的新的 mRNA 靶标。我们对结扎后 1 天和 3 天的缺血性心脏组织进行了小 RNA 测序（RNA-Seq），鉴定出 182 个差异表达的 miRNA。然后，我们通过将相应的 RNA-Seq 数据集的 miRNA 和 mRNA 表达相关联，从所有潜在靶标中选择相关的 mRNA 靶标。在此分析中，我们选择了 miR-125 家族中的两个 miRNA（miR-125a 和 miR-351）及其两个潜在的 mRNA 靶标，Xin 肌动蛋白结合重复蛋白 1（）和因子抑制缺氧诱导因子（），作为原理验证的焦点。我们发现 miR-125a 在结扎后丰度降低，XIRP1 丰度增加。相比之下，相关的鼠 miRNA miR-351 对缺血性损伤有明显的上调反应，相应的 FIH 表达下降。荧光素酶报告基因测定证实了这些 miRNA 和靶标之间的直接相互作用。总之，我们利用结合 miRNA 和 mRNA 表达数据的相关分析策略，鉴定了结扎后心脏中功能性 miRNA-mRNA 关系。这些发现为缺血性损伤的反应提供了深入的了解，并提出了未来的治疗靶点。
