Differential expression of beta-catenin and dickkopf-1 in the third trimester placentas from normal and preeclamptic pregnancies: a comparative study

BACKGROUND Beta-catenin is a key nuclear effector of Wnt signaling which could be antagonized by dickkopf-1(DKK1). Beta-catenin and DKK1 are involved in a variety of biological processes; however, their expression in the placenta with severe preeclampsia (PE) has not been elucidated. This study was aimed to detect the localization and compare the expression of beta-catenin and DKK1 in normal and preeclamptic placenta. METHODS Sixty pregnant women who underwent cesarean section were enrolled in this study, including 30 healthy pregnant women in the control group and 30 preeclamptic women in the severe PE group. Real-time polymerase chain reaction (real-time-PCR) and western blot were employed to detect the beta-catenin and DKK1 mRNA and protein expression levels, respectively, and their locations were evaluated by immunohistochemistry (IHC). RESULTS Our results indicated that beta-catenin and DKK1 were expressed predominantly in the syncytiotrophoblast and the extravillous trophoblast (EVT). The beta-catenin mRNA and protein expressions were significantly decreased, whereas the DKK1 significantly increased in preeclamptic placental tissues compared to normal placental controls. CONCLUSIONS In conclusion, decreased beta-catenin expression, as well as DKK1 over-expression might be associated with the process of the pathogenesis of PE. Further studies would elucidate their exact roles in the pathogenesis of PE.