Li Bin, Hu Jie, Chen Xingpeng
Department of Cardiac Surgery, Luoyang Central Hospital Affiliated to Zhengzhou University, Luoyang, Henan 471009, P.R. China.
Exp Ther Med. 2018 Jun;15(6):5125-5132. doi: 10.3892/etm.2018.6039. Epub 2018 Apr 10.
The aim of the present study was to determine the expression of plasminogen activator inhibitor-1 (PAI-1) and microRNA (miR)-30b in the blood of patients with acute myocardial ischemia (AMI) and in the blood and myocardial tissue of mice with AMI. In addition, the present study aimed to identify the mechanism of action of miR-30b in AMI. A total of 36 patients with AMI were included in the present study and 28 healthy subjects were included as a control. Peripheral blood was collected from all subjects. For animal experiments, mice in the AMI group received an intraperitoneal injection of pituitrin (20 U/kg), whereas mice in the negative control group received an intraperitoneal injection of the same volume of saline. Blood and myocardial tissue was collected from all mice for analysis. Reverse transcription-quantitative polymerase chain reaction was performed to determine the expression of PAI-1 mRNA and miR-30b in the serum and myocardial tissue. An enzyme-linked immunosorbent assay was performed to measure the expression of PAI-1 protein in the serum of humans and mice, whereas western blotting was performed to determine the expression of PAI-1 protein in mouse myocardial tissue. Catalase, glutathione peroxidase and superoxide dismutase activity was measured using an automatic biochemical analyzer. A dual luciferase assay was performed to identify the interactions between PAI-1 mRNA and miR-30b. The results indicated that patients with AMI have higher PAI-1 levels and lower miR-30b expression in the peripheral blood compared with healthy subjects. AMI damaged the myocardium tissue of mice and reduced catalase, glutathione peroxidase and superoxide dismutase activity. Mice that have undergone AMI exhibit increased PAI-1 levels but decreased miR-30b expression in the peripheral blood and myocardial tissues. It was also demonstrated that miR-30b is able to bind to the 3'-untranslated region of PAI-1 mRNA to regulate its expression. The present study demonstrates that patients with AMI exhibit decreased miR-30b expression and elevated PAI-1 expression in the peripheral blood. miR-30b may therefore inhibit the damage to myocardial cells that occurs following AMI and protect myocardial cell function by targeting PAI-1 expression.
本研究的目的是测定急性心肌缺血（AMI）患者血液以及AMI小鼠血液和心肌组织中纤溶酶原激活物抑制剂-1（PAI-1）和微小RNA（miR）-30b的表达。此外，本研究旨在确定miR-30b在AMI中的作用机制。本研究共纳入36例AMI患者，并纳入28例健康受试者作为对照。采集所有受试者的外周血。对于动物实验，AMI组小鼠腹腔注射垂体后叶素（20 U/kg），而阴性对照组小鼠腹腔注射相同体积的生理盐水。采集所有小鼠的血液和心肌组织进行分析。采用逆转录-定量聚合酶链反应测定血清和心肌组织中PAI-1 mRNA和miR-30b的表达。采用酶联免疫吸附测定法检测人和小鼠血清中PAI-1蛋白的表达，而采用蛋白质印迹法测定小鼠心肌组织中PAI-1蛋白的表达。使用自动生化分析仪测量过氧化氢酶、谷胱甘肽过氧化物酶和超氧化物歧化酶活性。采用双荧光素酶报告基因检测法确定PAI-1 mRNA与miR-30b之间的相互作用。结果表明，与健康受试者相比，AMI患者外周血中PAI-1水平较高，miR-30b表达较低。AMI损伤了小鼠的心肌组织，并降低了过氧化氢酶、谷胱甘肽过氧化物酶和超氧化物歧化酶活性。经历过AMI的小鼠外周血和心肌组织中PAI-1水平升高，但miR-30b表达降低。还证明miR-30b能够与PAI-1 mRNA的3'非翻译区结合以调节其表达。本研究表明，AMI患者外周血中miR-30b表达降低，PAI-1表达升高。因此，miR-30b可能通过靶向PAI-1表达来抑制AMI后发生的心肌细胞损伤并保护心肌细胞功能。
