Fig. 1

Strategy for identifying circulating miRNAs with the best discriminatory power in detecting post-AMI AKI. a Quantification of 36 miRNAs by qRT-PCR in 108 serum samples. The means of individual miRNA expressions are presented as 40-Ct, and sorted in a descending order. The gray bars indicate the non-detected rate (%) of each miRNA, which was defined as the percentage of samples with Ct > 40. b Sample hemolysis was determined by the absorbance of hemoglobin at 414 nm greater than 0.2. The means and standard errors for the expression levels of 31 miRNAs in the hemolytic and the non-hemolytic groups were calculated. (*P < 0.05; **P < 0.01; ***P < 0.001). c 15 of 17 miRNAs are significantly altered among all 4 groups (determined by non-parametric Kruskal–Wallis test). The significant levels of the 15 miRNAs of the AMI⁺AKI⁻ versus AMI⁺AKI⁺ groups and the AMI⁻AKI⁻ versus AMI⁻AKI⁺ groups are indicated (− Log P-values above 1.301 was considered significant). P-values are calculated by Dunn’s multiple comparison test. d Flow chart displaying the step-wise strategy for practical miRNA biomarkers selection. AKI acute kidney injury, AMI acute myocardial infarction, AUC area under receiver operating characteristic curve, ND not detected