Markers of epithelial-mesenchymal transformation in the placenta and amniotic membranes by chorioamnionitis

Abstract

Premature rupture of membranes (PROM) is a significant problem in obstetric practice, causing significant complications for both the mother and the fetus.

Aim - to study the prevalence of markers of epithelial-mesenchymal transformation (EMT) in placentas from women with PROM depending on the level of glucose in the amniotic fluid and gestational age.

Materials and methods. A study was conducted on the placentas of 40 women, which, depending on the gestational age and the determined amniotic glucose concentration, were divided into groups: I group - 10 placentas from births at 24-37 weeks against the background of amniotic glucose concentration <0.5 mmol/l, II group - 10 placentas from births at 24-37 weeks by amniotic glucose concentration ≥0.5 mmol/l, III group - 10 placentas from term births  with amniotic glucose concentration <0.5 mmol/l, IV group - 10 placentas from term by amniotic glucose concentration ≥0.5 mmol/l. In all placentas the content of vimentin and cytokeratin in the amnion and decidual membrane was determined by immunohistochemical method.

Results. In the II group cytokeratin expression was 0.178±0.006 c.u., which was significantly higher compared to the I group (0.156±0.007 c.u), in full-term pregnancies - 0.186±0.007 c.u and 0.138±0.005 c.u in the III group and the IV group respectively. In the I group vimentin expression was 0.267±0.004 c.u, but in the I group decreased to 0.178±0.003 c.u, in full-term pregnancies vimentin was also lower in the III group (0.138±0.006 c.u) compared to the IV group (0.207±0.005 c.u). This pattern indicates that low glucose levels suppress mesenchymal activity of chorionic villus cells

Conclusions. Chorioamnionitis as a complication of PROM is accompanied by significant structural rearrangements of placental tissues and amniotic membranes, which is manifested by a decrease in the expression of cytokeratin (a marker of epithelial cells) and an increase in the level of vimentin (a mesenchymal marker). This indicates a weakening of epithelial properties and activation of mesenchymal transformation. A clear dependence of the level of cytokeratin and vimentin expression on the glucose concentration in the amniotic fluid and gestational age was revealed: in the groups with low glucose levels (<0.5 mmol/l) a significant decrease in cytokeratin was observed, indicating a loss of epithelial cell integrity. An increase in vimentin levels at low glucose levels is associated with EMT activation, structural destabilization of membranes and an increased risk of their rupture.

The study was conducted in accordance with principles of the Declaration of Helsinki. Research protocol was approved by local ethics committee of the participating institution. Informed consent was obtained.

The authors declare no conflict of interest.