Abstract
BackgroundThe dysregulated expressions of circulating miRNAs have been detected in various cardiovascular diseases. In our previous experiments, the altered expressions of circulating miRNA-21-5p, miRNA-361-5p and miRNA-519e-5p were confirmed in patients with coronary atherosclerosis by miRNA microarrays. However, the expression levels of these circulating miRNAs in the early phase of acute myocardial infarction (AMI) are still unknown. In the present study, our aims were to examine the expressions of circulating miR-21-5p, miR-361-5p and miR-519e-5p in AMI patients, and assess their clinical applications for diagnosing and monitoring AMI.ResultsTwo different cohorts were enrolled in this study. The first cohort included 17 AMI patients and 28 healthy volunteers, and the second cohort included 9 AMI patients, 9 ischemic stroke patients, 8 patients with pulmonary embolism, and 12 healthy volunteers. Quantitative real-time PCR and ELISA assays were preformed to detect the concentrations of plasma miRNAs and cardiac troponin I (cTnI), respectively. The results showed that the plasma levels of miR-21-5p and miR-361-5p were significantly increased in AMI patients, whereas the concentration of circulating miR-519e-5p was reduced. Interestingly, the levels of these circulating miRNAs correlated with the concentrations of plasma cTnI. Receiver operating characteristic (ROC) analysis revealed that these three circulating miRNAs had considerable diagnostic accuracy for AMI with high values of area under ROC curve (AUC). Importantly, combining the three miRNAs significantly increased the diagnostic accuracy. Furthermore, cell experiments demonstrated that these plasma miRNAs may originate from injured cardiomyocytes induced by hypoxia. In addition, the levels of all the three circulating miRNAs in ischemic stroke (IS) and pulmonary embolism (PE) were elevated, whereas the decreased level of plasma miR-519e-5p was only detected in AMI. ROC analysis demonstrated that circulating miR-519e-5p may be a useful biomarker for distinguishing AMI from other ischemic diseases.ConclusionsCirculating miRNAs may be novel and powerful biomarkers for AMI and they could be potential diagnostic tool for AMI.
Highlights
The dysregulated expressions of circulating miRNAs have been detected in various cardiovascular diseases
To investigate the expression patterns of circulating miRNAs in early acute myocardial infarction (AMI), 17 patients with AMI and 28 healthy volunteers without evidence for coronary artery disease (CAD) were enrolled in the first cohort
Six blood samples were collected from each AMI patient at various time points as described in the Methods
Summary
The dysregulated expressions of circulating miRNAs have been detected in various cardiovascular diseases. The expression levels of these circulating miRNAs in the early phase of acute myocardial infarction (AMI) are still unknown. Some studies demonstrated that miRNAs are abundantly present in plasma/serum in a remarkably stable form and can be detected by real-time PCR assays [10,11,12], and the expression profiling of circulating miRNAs may change in various diseases. These results cTnI in AMI patients at a time course, The initial time (T0) was 12.461.5 hours after the onset of AMI symptoms. Data are presented as mean 6 SEM, *p,0.05, **p,0.01 versus healthy control; #p,0.05, ##p,0.01 versus peak level
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