Liu Hongxia, Li Guofen, Zhao Wenxue, Hu Yibo
Department of Clinical Laboratory Medicine, The Central Hospital of Nanyang, Nanyang, Henan, China (mainland).
Cell Morphology Inspection of Clinical Laboratory Medicine, The Central Hospital of Nanyang, Nanyang, Henan, China (mainland).
Med Sci Monit. 2016 Jul 14;22:2451-62. doi: 10.12659/msm.897266.
BACKGROUND This study was designed to investigate the effects of microRNA-92 (miR-92), Kruppel-like factor 2 (KLF2), and Kruppel-like factor 4 (KLF4) on endothelial injury after acute myocardial infarction (AMI). MATERIAL AND METHODS Blood samples were collected from 50 AMI patients for detection of cardiac troponin I (cTnI), heart-type fatty acid-binding protein (H-FABP), and von Willebrand factor (vWF). The Sprague-Dawley rat models of AMI (n=30) were established by ligating their left anterior descending coronary artery. The cardiac markers of AMI patients and rat models were analyzed with enzyme-linked immunosorbent assay and immunohistochemistry. Human umbilical vein endothelial cells were processed into 5 groups: control, negative control, miR-92a inhibitors, miR-92a inhibitors + KLF2 small interfering RNA (siRNA), and miR-92a inhibitors + KLF4 siRNA. Cell proliferation and apoptosis were detected using MTT assay and flow cytometry. RT-PCR and Western blot were conducted to analyze KLF2 and KLF4 expressions. RESULTS AMI patients exhibited significantly higher expression of both endothelial injury markers (e.g., cTnI, H-FABP, vWF) and miR-92a in blood samples, when compared with controls (P<0.05). Model rats also had similar expressional tendencies, along with lower KLF2 and KLF4 expressions (P<0.05). Further, it could be observed in cellular experiments that treatment of miR-92a mimics can further upregulate endothelial injury markers, and miR-92a and both KLF2 and KLF4 were downregulated by miR-92a mimics (all, P<0.05). Also, the luciferase activity assay confirmed the direct binding of miR-92a to 3' UTR of KLF2/4. CONCLUSIONS MiR-92a was involved in the endothelial injury process after AMI and was able to suppress KLF2 and KLF4 expression.
背景 本研究旨在探讨微小RNA-92（miR-92）、Kruppel样因子2（KLF2）和Kruppel样因子4（KLF4）对急性心肌梗死（AMI）后内皮损伤的影响。材料与方法 收集50例AMI患者的血样，检测心肌肌钙蛋白I（cTnI）、心型脂肪酸结合蛋白（H-FABP）和血管性血友病因子（vWF）。通过结扎左冠状动脉前降支建立Sprague-Dawley大鼠AMI模型（n=30）。采用酶联免疫吸附试验和免疫组织化学方法分析AMI患者和大鼠模型的心脏标志物。将人脐静脉内皮细胞分为5组：对照组、阴性对照组、miR-92a抑制剂组、miR-92a抑制剂+KLF2小干扰RNA（siRNA）组和miR-92a抑制剂+KLF4 siRNA组。采用MTT法和流式细胞术检测细胞增殖和凋亡。采用RT-PCR和Western blot法分析KLF2和KLF4的表达。结果 与对照组相比，AMI患者血样中内皮损伤标志物（如cTnI、H-FABP、vWF）和miR-92a的表达均显著升高（P<0.05）。模型大鼠也有类似的表达趋势，同时KLF2和KLF4的表达较低（P<0.05）。此外，在细胞实验中可以观察到，miR-92a模拟物处理可进一步上调内皮损伤标志物，miR-92a模拟物可下调miR-92a以及KLF2和KLF4的表达（均P<0.05）。此外，荧光素酶活性测定证实miR-92a与KLF2/4的3'UTR直接结合。结论 miR-92a参与了AMI后的内皮损伤过程，并能够抑制KLF2和KLF4的表达。
