Circulating microRNAs are elevated in plasma from severe preeclamptic pregnancies

Until recently, the molecular pathogenesis of preeclampsia (PE) remained largely unknown. Reports have shown that circulating microRNAs (miRNAs) are promising novel biomarkers for cancer, pregnancy, tissue injury, and other conditions. The objective of this study was to identify differentially expressed miRNAs in plasma from severe preeclamptic pregnancies compared with plasma from normal pregnancies. By mature miRNA microarray analysis, 15 miRNAs, including 13 up- and two downregulated miRNAs, were screened to be differentially expressed in plasma from women with severe PE (sPE). Seven miRNAs, namely miR-24, miR-26a, miR-103, miR-130b, miR-181a, miR-342-3p, and miR-574-5p, were validated to be elevated in plasma from severe preeclamptic pregnancies by real-time quantitative stem-loop RT-PCR analysis. Gene ontology and pathway enrichment analyses revealed that these miRNAs were involved in specific biological process categories (including regulation of metabolic processes, regulation of transcription, and cell cycle) and signaling pathways (including the MAP kinase signaling pathway, the transforming growth factor-β signaling pathway, and pathways in cancer metastasis). This study presents, for the first time, the differential expression profile of circulating miRNAs in sPE patients. The seven elevated circulating miRNAs may play critical roles in the pathogenesis of sPE, and one or more of them may become potential markers for diagnosing sPE.