Analyses of placental gene expression in pregnancy-related hypertensive disorders

Objective: To explore the changes in placental gene expression between women with preeclampsia and those with superimposed preeclampsia on chronic hypertension. Materials and Methods: In Taiwanese population, we compared gene expression between the placentas from preeclamptic patients and those with superimposed preeclampsia on chronic hypertension. Results: Although top-ranked activated genes between preeclampsia and superimposed preeclampsia on chronic hypertension were different, functional network analyses indicate that these genes are mainly involved in the regulation of cell death and apoptosis. These results suggest that apoptosis and other types of cell death in the placenta are common consequences of both diseases. However, placental endoglin (ENG) was expressed at a significantly higher level in preeclampsia than in superimposed preeclampsia. Results of functional network analysis indicated that ENG may play a role in the pathogenesis of preeclampsia through its interference with the endothelial nitric oxide synthase-regulated vasodilation. Conclusion: Our results support the fact that ENG is the culprit for the development of preeclampsia. In addition, this study identifies several other genes in the placenta, which are transcriptionally regulated in pregnancy-related hypertensions.