College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, P. R. China.
Metallomics. 2019 Feb 20;11(2):415-428. doi: 10.1039/c8mt00319j.
Selenium (Se) is imperative for normal myocardial differentiation and development, and these basic cellular functions can be regulated by miRNA during cardiogenesis. Here, we show that Se deficiency can cause defects in myocardial development and abnormalities of cardiomyocyte differentiation. In previous work using microRNAome analysis, we found that miR-215-5p was differentially expressed in Se-deficient myocardial tissues. However, the relationship between miR-215-5p and Se deficiency in myocardial development remains unknown. In this study, CCCTC-binding factor (CTCF) was confirmed as the target gene of miR-215-5p by dual luciferase reporter assay, western blot and quantitative real-time polymerase chain reaction (qRT-PCR) in cardiomyocytes. Based on in vivo and in vitro results, we found that the increased expression of miR-215-5p induced by Se deficiency may cause transcriptional disorders of myocardial genes, mitochondrial biosynthesis imbalance, and a reduction of myocardial development and differentiation-related factors. Moreover, miR-215-5p may target CTCF to regulate myocardial development and differentiation via the noncanonical Wnt signaling pathway and induce mitochondrial dysfunction via the PGC-1α-TFAM-NRF1/2 pathway in the heart. Our results not only demonstrated that Se deficiency affected myocardial development and differentiation by directly targeting the miR-215-5p/CTCF axis but also found that miR-215-5p inhibitor promoted normal differentiation of cardiomyocytes and myocardial development and ameliorated myocardium structural abnormalities via the noncanonical Wnt signaling pathway in chicken. Our findings support the potential of applying miRNAs during the process of cardiogenesis and indicate that miR-215-5p could be a novel candidate for treatment of cardiac hypoevolutism.
硒（Se）对于正常的心肌分化和发育是必不可少的，而这些基本的细胞功能可以在心脏发生过程中被 miRNA 调节。在这里，我们表明硒缺乏可导致心肌发育缺陷和心肌细胞分化异常。在之前使用 microRNAome 分析的工作中，我们发现 miR-215-5p 在硒缺乏的心肌组织中差异表达。然而，miR-215-5p 与心肌发育中的硒缺乏之间的关系仍不清楚。在这项研究中，通过双荧光素酶报告基因检测、western blot 和定量实时聚合酶链反应（qRT-PCR），证实了 CTCF 是 miR-215-5p 的靶基因。基于体内和体外的结果，我们发现硒缺乏引起的 miR-215-5p 表达增加可能导致心肌基因转录紊乱、线粒体生物合成失衡以及心肌发育和分化相关因子减少。此外，miR-215-5p 可能通过非经典 Wnt 信号通路靶向 CTCF 来调节心肌发育和分化，并通过 PGC-1α-TFAM-NRF1/2 通路在心脏中诱导线粒体功能障碍。我们的研究结果不仅表明硒缺乏通过直接靶向 miR-215-5p/CTCF 轴影响心肌发育和分化，而且发现 miR-215-5p 抑制剂通过非经典 Wnt 信号通路促进鸡心肌细胞的正常分化和心肌发育，并改善心肌结构异常。我们的研究结果支持在心脏发生过程中应用 miRNAs 的潜力，并表明 miR-215-5p 可能是治疗心脏发育不全的一种新的候选药物。
