Comparative analysis of miRNA expression between normal and pregnancy-induced hypertension placenta

Abstract

Pregnancy-induced hypertension (PIH) may threaten both maternal and fetal lives. The molecular mechanism underlying the development of PIH has not been clarified. MicroRNAs (miRNAs) have been proved to play a critical role in post-transcriptional gene regulation. Although majority of miRNAs are ubiquitously expressed in mammals, some minority of miRNAs exhibit specific expressional patterns in an organ- or cell-type-dependent manner. In this study, the profiling of miRNAs was constructed by the large-scale, high-throughput sequencing method from the normal and PIH placentas. A total of 5,368,807 and 4,954,045 miRNAs which have matched the miRNA sequence library were identified by cloning from the normal and PIH placentas respectively and three novel miRNAs which could not match the sequence library of updated miRNAs warranted further confirmation. Comparing miRNA data between normal and PIH placenta, eight microRNAs were found significantly upregulated in human PIH placentas, the majority of them were clustered on the chromosome 19 and were assumed placenta-specific. The upregulated expression of the eight miRNAs was further identified by quantitative RT-PCR assays. In summary, a significant differentiated expression between normal miRNA libraries and PIH miRNA libraries was revealed, which suggests abnormal miRNA regulation might be involved in the pathogenesis of PIH. Simultaneously, our larger-scale sequencing results has provided a general insight on exploring the pathogenesis of PIH from an miRNA-based method.