Demonstration of all-or-none loss of imprinting in mRNA expression in single cells.

Loss of imprinting (LOI) is the reactivation of the silenced allele of an imprinted gene, leading to perturbation of monoallelic expression. We tested the hypothesis that LOI of PLAGL1, a representative maternally imprinted gene, occurs through an all-or-none process leading to a mixture of fully imprinted and nonimprinted cells. Herein using a quantitative RT-PCR-based experimental approach, we measured LOI at the single cell level in human trophoblasts and demonstrated a broad distribution of LOI among cells exhibiting LOI, with the mean centered at approximately 100% LOI.

Placental expression of ceruloplasmin in pregnancies complicated by severe preeclampsia.

There is consensus that ischemia/reperfusion injury associated with preeclampsia (PE) promotes both placental damage and the release of factors leading to maternal endothelium dysfunction, a hallmark of this potentially life-threatening syndrome. These factors include plasminogen activator inhibitor-1 (PAI-1) and soluble fms-like tyrosine kinase-1 (sFlt-1). The goal of this study was to further characterize placental factors involved in the pathophysiology of PE.

The placental syncytium and the pathophysiology of preeclampsia and intrauterine growth restriction: a novel assay to assess syncytial protein expression.

Preeclampsia is associated with an increased release of factors from the placental syncytium into maternal blood, including the antiangiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin, the antifibrinolytic factor plasminogen activator inhibitor-1, prostanoids, lipoperoxides, cytokines, and microparticles. These factors are suggested to promote maternal endothelium dysfunction and are associated with placental damage in pregnancies also complicated with intrauterine growth restriction (IUGR). In this report, we briefly describe the interaction of syncytial factors with hypoxia, reactive oxygen species, and apoptosis in the pathophysiology of preeclampsia and IUGR.