[The pathogenetic role and expression profile of microRNAs in preeclampsia]

Preeclampsia is the leading cause of maternal and fetal morbidity and mortality that affects 3-8% of pregnancies worldwide. Its main symptoms include new onset of high blood pressure and proteinuria after 20 weeks of pregnancy. The cause of the disease is still debated. microRNAs are short, non-coding RNA molecules that play a pivotal part in the posttranscriptional regulation of eukaryotic genes. They are involved in fine-tuning of vital physiological processes such as cell cycle, proliferation, differentiation and cell death. In genomic studies, hundreds of microRNAs were detected in the placenta, which are supposed to regulate placental development and contribute to uncomplicated pregnancy. Several studies have reported changes in the expression of microRNAs in pregnancy. Abnormal microRNA expression may have a role in the development of preeclampsia as it affects the proliferation, migration, and invasion of the trophoblast cells, spiral artery remodeling, and angiogenesis. Some placental microRNAs (e.g., the C19MC microRNA cluster) are able to reach the maternal circulation through their release via exosomes from the trophoblast layer. These 'circulating' microRNA molecules can be applied as biomarkers for the detection of various placental disorders owing to their stability and specificity. Orv Hetil. 2018; 159(14): 547-556.