Identification of differentially expressed miRNAs in plasma exosomes from patients with early-onset pre-eclampsia using next generation sequencing

Pre-eclampsia (PE), a major cause of perinatal morbidity and mortality, accounts for up to 14 % mortality of maternal and 18 % of fetal or infant mortalities. However, the pathogenesis process of PE remains unclear. The aim of this study was to identify differentially expressed microRNAs (miRNAs) in the peripheral blood exosomes of early-onset PE patients versus healthy pregnant women using high-throughput sequencing, and to find candidate miRNAs as molecular markers. Methods: Peripheral blood samples were collected from five preeclamptic patients and five healthy women. Exosomal miRNAs were sequenced using the Illumina HiSeq4000 sequencing platform. The target gene prediction, biological function enrichment, and signaling pathway prediction of the miRNAs with significant differences were carried out using the Starbase database software, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Our results showed 65 significantly differentially expressed miRNAs in the exosomes of early-onset PE patients compared to control group, with 17 up-regulated and 48 down-regulated (P < 0.05). A total of 2231 target genes were predicted for all differentially expressed miRNAs. Biological functions enriched by these target genes were mainly associated with Ras protein signal transduction, GTPase-mediated signal transduction regulation, histone modification, and beta-transforming growth factor regulatory process. Key regulatory signaling pathways included TGF-beta signaling pathway, PI3K-Akt signaling pathway, MAPK signaling pathway, tumor necrosis factor signaling pathway and EGFR tyrosine kinase inhibition signaling pathways. QPCR validation in 40 independent samples for 10 miRNAs, identified three miRNAs were confirmed in the second population. MIR7151 was a most significant differentially expressed miRNAs, and predicted its downstream regulatory gene, KCNQ10T1, using Starbase software. There were significant differences in miRNA expression profiles between peripheral blood exosomes of early-onset PE patients and normal pregnant women, suggesting that these miRNAs may contribute to the pathophysiology of early -onset PE by regulating various biological functions and signaling pathways.