Differential expression of microRNAs in plasma of patients with prediabetes and newly diagnosed type 2 diabetes

MicroRNAs (miRNAs) are present in plasma and have emerged as critical regulators of gene expression at posttranscriptional level, and thus are involved in various human diseases, including diabetes. The objective of this study was to screen and validate differentially expressed plasma miRNAs in prediabetes and newly diagnosed type 2 diabetes (T2D). In this study, we screened differentially expressed plasma miRNAs in prediabetes and newly diagnosed T2D by miRNA microarray analysis, and validated the expression of candidate miRNAs using quantitative reverse transcription polymerase chain reaction assays. Furthermore, we performed gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses to disclose functional enrichment of genes predicted to be regulated by the differentially expressed miRNAs. Notably, our results revealed that hsa-miR-1249, hsa-miR-320b, and hsa-miR-572 (P < 0.05) were differentially expressed among the three groups, which yielded an area under the receiver operator characteristics curve (AUC) of 0.784 [95 % confidence interval (CI) 0.685-0.883], 0.946 (95 % CI 0.906-0.985), and 0.843 (95 % CI 0.766-0.920) discriminating T2D patients from NGT control groups, respectively, while the AUC was 0.887 (95 % CI 0.818-0.957), 0.635 (95 % CI 0.525-0.744), and 0.69 (95 % CI 0.580-0.793) discriminating prediabetes patients from NGT control groups, respectively. In addition, GO and KEGG pathway analyses showed that genes predicted to be regulated by differentially expressed miRNAs were significantly enriched in several related biological processes and pathways, including the development of multicellular organisms, signal transduction, cell differentiation, apoptosis, cell metabolism, ion transport regulation, and other biological functions. Taken together, our results showed differentially expressed miRNAs in T2D and prediabetes. Plasma hsa-miR-1249, hsa-miR-320b, and hsa-miR-572 may serve as novel biomarkers for diagnosis and potential targets for the treatment for prediabetes and T2D.