Differential expression of microRNAs in the placentae of Chinese patients with severe pre-eclampsia.

BACKGROUND The pathogenesis of pre-eclampsia (PE) is incompletely understood. The placenta is considered to play a key role in this disease. Recent research showed that many microRNAs (miRNAs) are expressed in human placenta. Our aim in this study was to determine differential expression of miRNAs in placenta with severe PE, and normal placenta. METHODS Differential expression of miRNAs in placenta (four severe PE and a control group of four normal pregnant women) was first screened using microarray analysis. Following this, some differential miRNAs were selected and validated using real-time quantitative reverse transcription-polymerase chain reaction in placenta from women with severe PE (n=24), and a healthy control group (n=26). RESULTS We found the following miRNAs were significantly increased in placenta from women with severe PE: miR-16, miR-29b, miR-195, miR-26b, miR-181a, miR-335 and miR-222. Gene ontology analysis of the target genes revealed enrichment for specific biological process categories, i.e., regulation of cellular physiological process including miR-16, miR-29b, miR-195, miR-26b and miR-335, and signal transduction including miR-181a and miR-222. CONCLUSIONS These different miRNAs may play an important role in pathogenesis of PE and may become diagnostic markers for PE.