A comprehensive survey of maternal plasma miRNAs expression profiles using high-throughput sequencing

Recently, microRNAs (miRNAs) had been shown as potential important regulators in pregnancy. Circulating miRNAs are considered as potentially useful non-invasive biomarkers for the diagnosis of pregnancy-related disease and congenital disorders, but maternal peripheral blood miRNAs expression profile in pregnancy remains less investigated. We thus set out to investigate maternal plasma miRNAs expression profile using genome-wide sequencing.

Maternal plasma miRNA expression profiles of different pregnancy stages were detected by SOLiD sequencing. We observed the expression level of the most abundant miRNAs in maternal plasma during pregnancy process. We examined functional relationships of targets of pregnancy-relative miRNAs by enrichment analyzing of signaling pathways.

147 miRNAs were sequenced from maternal plasma in this study, among them, 90 types of miRNAs were found in all of the samples, while 136 miRNAs in the first trimester gestation, 108 in second trimester gestation, and 99 miRNAs in the third trimester gestation, respectively. The varieties and the expression level of maternal plasma miRNAs were changing during pregnancy. The expression level of miRNA cluster members was changing with the same trend during pregnancy. The function and functional relationship analysis of target genes of pregnancy-relative miRNAs showed that genetic disorder, immunological disease, cell signaling, cancer, and cell cycle were the enriched pathways.

Maternal plasma miRNA expression profiles are dynamically changing during pregnancy. The results of function analysis suggested that miRNAs may play an important role in regulating pregnancy process, which can help us understand the refine regulation mechanism in pregnancy. Moreover, the results of this present study may be the basis for a further study to find useful prenatal diagnosis biomarkers.