MicroRNA-125b protects against myocardial ischaemia/reperfusion injury via targeting p53-mediated apoptotic signalling and TRAF6
MicroRNA-125b protects against myocardial ischaemia/reperfusion injury via targeting p53-mediated apoptotic signalling and TRAF6
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DOI：
10.1093/cvr/cvu044
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发表时间：
2014-06-01
影响因子：
10.8
通讯作者：
Li, Chuanfu
中科院分区：
文献类型：
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作者：
Wang, Xiaohui;Ha, Tuanzhu;Li, Chuanfu
本研究探讨了 microRNA-125b (miR-125b) 在心肌缺血/再灌注 (I/R) 损伤中的作用。我们构建了表达慢病毒的miR-125b（LmiR-125b）并开发了miR-125b过表达的转基因小鼠。LmiR-125b通过右颈总动脉转染到小鼠心脏中。慢病毒载体（LmiR-Con）用作载体对照。未治疗的小鼠作为 I/R 对照。假手术作为假手术对照。转染后7天，使心脏缺血（45分钟），然后再灌注（4小时）。通过2,3,5-三苯基氯化四唑染色分析心肌梗塞大小。在单独的实验中，心脏遭受缺血（45 分钟），然后再灌注长达 7 天。在心肌I/R之前以及之后3天和7天通过超声心动图测量心功能。 miR-125b 表达增加可显着降低 I/R 诱导的心肌梗死面积 60%，并阻止 I/R 诱导的射血分数 (EF%) 和缩短分数 (%FS) 降低。过度表达 miR-125b 的转基因小鼠也显示出对心肌 I/R 损伤的保护作用。 miR-125b 表达增加可减弱 I/R 诱导的心肌细胞凋亡以及 caspase-3/7 和 -8 活性。 Western blot 显示，miR-125b 表达增加会抑制心肌中 p53 和 Bak1 的表达。此外，转染LmiR-125b可降低TNF受体相关因子6 (TRAF6)的水平，并阻止I/R诱导的NF-kappa B激活。miR-125通过阻止p53介导的细胞凋亡信号传导和抑制TRAF6介导的NF-kappa B激活来保护心肌免受I/R损伤。
The present study examined the role of microRNA-125b (miR-125b) in myocardial ischaemia/reperfusion (I/R) injury. We constructed lentivirus-expressing miR-125b (LmiR-125b) and developed transgenic mice with overexpression of miR-125b.LmiR-125b was transfected into mouse hearts through the right common carotid artery. Lentivirus vector (LmiR-Con) served as vector control. Untreated mice served as I/R control. Sham operation served as sham control. Seven days after transfection, the hearts were subjected to ischaemia (45 min) followed by reperfusion (4 h). Myocardial infarct size was analysed by 2,3,5-triphenyltetrazolium chloride staining. In separate experiments, hearts were subjected to ischaemia (45 min) followed by reperfusion for up to 7 days. Cardiac function was measured by echocardiography before, as well as 3 and 7 days after myocardial I/R. Increased expression of miR-125b significantly decreased I/R-induced myocardial infarct size by 60% and prevented I/R-induced decreases in ejection fraction (EF%) and fractional shortening (%FS). Transgenic mice with overexpression of miR-125b also showed the protection against myocardial I/R injury. Increased expression of miR-125b attenuated I/R-induced myocardial apoptosis and caspase-3/7 and -8 activities. Western blot showed that increased expression of miR-125b suppresses p53 and Bak1 expression in the myocardium. In addition, transfection of LmiR-125b decreased the levels of TNF receptor-associated factor 6 (TRAF6) and prevented I/R-induced NF-kappa B activation.miR-125 protects the myocardium from I/R injury by preventing p53-mediated apoptotic signalling and suppressing TRAF6-mediated NF-kappa B activation.