Expression of NF-κB and VEGF in normal placenta and placenta previa patients

Background: Placenta previa is a pregnancy condition associated with the development of complications related to placental insufficiency, including hypertension, preeclampsia and perinatal mortality. Dysfunction in uteroplacental arteries causes the release of cytokines, leukotrienes and immunomodulatory hormones, which leads to an inflammatory reaction.

Objectives: The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway and vascular endothelial growth factor (VEGF) are known to play crucial roles in inflammation and angiogenetic regulation. This study aimed to demonstrate the morphometric and immunohistochemical effects on inflammation and angiogenesis underlying placenta previa.

Material and methods: Twenty pregnant patients with placenta previa and 20 healthy pregnant patients, all between 30 and 38 weeks gestational age, were included in the study. The gestational age of the pregnancies was determined according to the last date of menstruation and/or ultrasonographic measurements. Blood samples and clinical data were obtained from the prenatal patient groups. Samples were taken from the connecting stem region from both groups.

Results: The mean difference between the control and placenta previa patients was statistically significant for the parameters of blood vessels in villi, diameter of floating small villus, decidual cells, syncytial knots, congestion in blood vessels, fibrinoid accumulation, and inflammation. Significant degeneration and apoptotic changes in the syncytial cells of the root villi and an increase in syncytial nodes and bridges were observed in the placenta previa specimens. In the connecting stem region of the placenta previa samples, blood vessel dilatation, endothelial cell hyperplasia and a higher number of syncytial nodes were observed. In the immunohistochemical examination of the placenta previa samples, an increase in NF-κB and VEGF expression was observed in the endothelial cells, syncytial cells and Hofbauer cells.

Conclusions: Vascular endothelial growth factor was found to stimulate endothelial cell proliferation and migration, and to significantly affect angiogenesis during the developmental process of the placenta and remodeling of the uterine vessels, inducing NF-κB signaling and apoptotic development during cytotrophoblastic invasion in the vascularization of the placenta.