Molecular mechanisms involved in pre-eclampsia through expressional regulation of endothelin-1

Preeclampsia (PE) is a condition affecting 2-8% of all pregnancies and is a leading cause of perinatal morbidity and mortality. In our study; we aim to investigate the differences in endothelin-1 (ET-1) at both tissue and blood level in the placenta, umbilical cord, and maternal blood obtained from different experimental groups and the changes in the contraction response of umbilical arteries in order to explain how PE affects mother and fetus.

Umbilical cord and placenta samples were obtained from normotensive controls (n = 10) and patients with preeclampsia (n = 10), aged 20-39 years, who delivered by cesarean section at term (between 37 and 39 weeks). All samples were investigated with isolated tissue bath, histopathological, immunohistochemical and real-time PCR methods.

ET-1 messenger RNA expression levels and immunoreactivity were found significantly higher in the PE group while microRNA-1 and microRNA-125b (miR-125b) levels were significantly decreased in placenta compared to control. miR-125b levels were found significantly higher in maternal and umbilical cord blood samples of the PE group. The enlargement in intervillous space, decrease in villous branching, increase in syncytial knots and smaller lumen areas in umblicard cord vessels were also observed. In tissue bath experiments, there were no significant differences in ET-1 responses between groups.

We tried to evaluate molecular mechanisms of PE pathogenesis through expressional regulation and contraction response of ET-1. Although quite abundant work in this field has previously highlighted the importance of ET-1 system, further work is needed to determine the molecular mechanisms underlying expressional regulation of ET-1 in PE.