The expression of cell cycle related proteins PCNA, Ki67, p27 and p57 in normal and preeclamptic human placentas.

Placenta is a transitional area making many physiological activities between mother and fetus and therefore, it is a critical organ influencing the outcome of pregnancy. Fetal growth is directly related to placental development. Accurate placental development depends on coordinated action of trophoblasts' proliferation, differentiation and invasion. Information on cell cycle related proteins that control these events is limited and how they are affected in preeclampsia is not fully understood yet. Therefore, in this study, in order to understand the role of cell cycle regulators in preeclamptic placentas we aimed to determine the spatio-temporal immunolocalizations of cell cycle regulators in preeclamptic and normal human term placentas. Term placentas were obtained from women diagnosed with preeclampsia and from normal pregnancies with informed consent following cesarean deliveries. Placental samples were stained via immunohistochemistry with PCNA, Ki67, p27, p57, vimentin and cytokeratin 7 antibodies and were examined by light microscopy. PCNA and Ki67 staining intensities significantly increased in villous parts, significantly decreased in basal plates of PE group and did not change in chorionic plates. Staining intensities of cell cycle inhibitors p27 and p57 significantly increased in all parts of preeclamptic placentas compared to control. Placental abnormalities of preeclamptic placentas might be associated with proliferation and cell cycle arrest mechanisms' alterations occurred in preeclampsia.