RESUMO
Objective To explore the expression profiles of circulating microRNA(miRNA)and potential markers for the diagnosis of adult fulminant myocarditis(FM). Methods The expression profiles of circulating miRNA were determined by microarray analysis and verified by real-time quantitative PCR.The key role of circulating miRNA in FM was determined via KEGG pathway enrichment.The correlations between miRNA and cardiac function parameters in patients with FM were analyzed.The receiver operating characteristic(ROC)curve was established to evaluate the sensitivity and specificity of circulating miRNA in the diagnosis of FM. Results Compared with healthy controls,the FM patients had up-regulated expression levels of miR-29b(t=18.925,P<0.001)and miR-125b(t=5.981,P=0.029)in the plasma.After treatment,the expression levels of miR-29b(t=12.943,P<0.001)and miR-125b(t=14.016,P<0.001)were significantly down-regulated.KEGG pathway enrichment showed that the targets of miR-29b were involved in inflammatory response and apoptosis pathways.The results of cell proliferation and apoptosis assay demonstrated the transfection of miR-29b mimic had a more significant inducing effect on cardiomyocyte apoptosis than that of miR-125b mimic(χ 2=6.168,P=0.047),whereas there was no significant difference in the inhibition of cell proliferation between the two groups(χ2=1.452,P=0.417).The expression levels of miR-29b and miR-125b were negatively correlated with left ventricular ejection fraction(r=-0.67,P=0.071;r=-0.49,P=0.003).They were positively correlated with cardiac troponin I level(r=0.61,P=0.019;r=0.52,P=0.016),interferon β level(r=0.42,P=0.014;r=0.36,P=0.021),and myocardial edema area(r=0.86,P=0.005;r=0.73,P=0.013).The ROC curve analysis demonstrated that miR-29b had higher sensitivity for the diagnosis of FM(93.6% vs.89.2%;t=0.896,P=0.795)and specificity(72.4% vs.59.6%;t=9.478,P=0.002)than miR-125b. Conclusion The circulating miR-29b may be a potential biomarker for the diagnosis of FM.