Placental mesenchymal dysplasia associated with androgenetic/biparental mosaicism

s / Placenta 34 (2013) A1–A99 A25 Objectives: The placenta is arguably the most anatomically variable organ in mammals. Understanding gene expression patterns among placentas from multiple species can illuminate the molecular basis of placenta function. The placentas of most marsupials are distinguished from those of eutherianmammals by being predominantly derived from the chorion and yolk sac, as well as apposing maternal tissue for a relatively shorter period of time. Here we characterize the mRNA landscape of the Monodelphis placenta. Methods: In order to gain insight regarding the molecular features that distinguish marsupial placentas from their eutherian counterparts, we profiled the term placenta of the gray short-tailed opossum (Monodelphis domestica) using RNA-Seq, and compared this transcriptome to that of six species of eutherian mammals. Results: We show substantial expression of galectins in the opossum, especially LGALS1, as well as cathepsins. This implies that high galectin and cathepsin expression, common in the placentas of eutherians, is the ancestral state in therian mammals. The opossum placenta also shows abundant expression of embryonic andmarsupial-specific hemoglobins, in addition to a novel gene that was lost in eutherians. Unlike the tammar wallaby, growth hormone and prolactin were not expressed in the opossum placenta, but relaxin showed moderate expression levels. Overrepresentation of functional annotation categories of genes that showed relatively increased expression on the opossum lineage were clustered in many categories not seen in other mammalian lineages (Placenta 34(2): A67), including mitochondrion, peroxisome, urea cycle, glycolysis, and cell membrane transport. Conclusions: These findings imply that the choriovitelline placenta characteristic of marsupials is metabolically active, as well as suggesting placental involvement in the transport of nutrients between maternal and fetal tissues. In addition, the high expression of genes engaged in the urea cycle may be Monodelphis specific, as the opossum lacks a vesicular allantois to exchange waste, unlike many other marsupials. http://dx.doi.org/10.1016/j.placenta.2013.06.075 P1.39. PLACENTAL MESENCHYMAL DYSPLASIA ASSOCIATED WITH ANDROGENETIC/BIPARENTAL MOSAICISM Atsuko Hichijo, Mikio Morine Department of Maternal Fetal Medicine, Center for Maternal, Fetal and Neonatal Medicine, National Hospital Organization, Kagawa Children's Hospital, Zentsuji, Japan Objectives: Placental mesenchymal dysplasia (PMD) is a distinct syndrome of unknown etiopathogenesis associated with significant fetal morbidity and mortality. We report two cases of PMD with trisomy and tetrasomy mosaic cells in the placenta. Case 1: The case was referred at 14 weeks of gestation because of suggesting molar placenta with a live fetus. The amniocentesis detected the diploid karyotype of the fetus. As the result of breach presentation, cesarean section was performed at 37 weeks of gestation. Chromosomal analysis of cord blood and placenta confirmed karyotype of 46,XY and 48,XY,+7,+16/46,XY, respectively. Case 2: The case was referred at 15 weeks of gestation because ultrasound scan showedmolar like placenta with a live fetus. At 17 weeks of gestation, the amniocentesis showed a karyotype of 47,XX,+5/46,XX. Cordocentesis performed at 20 weeks of gestation revealed a normal female karyotype. Subsequent ultrasound examinations revealed the fetus associated with fetal intra-abdominal umbilical vein (FIUV) varix and two large hepatic tumors. At 32 weeks of gestation, as the results of previous cesarean birth and the possibility of intrauterine demise due to FIUV varix, cesarean section was performed at 32 weeks of gestation after antenatal corticosteroid therapy for fetal lung maturation. Chromosome analysis of cord blood and placenta confirmed karyotype of 46,XX and 47,XX,+5/46,XX, respectively. In the both cases, molecular genetic analysis using a single nucleotide polymorphism (SNP) microarray was performed on placental samples from case 2 and confirmed an excess of placental alleles, consistent with the presence of confined placental androgenetic/biparental mosaicism for paternal uniparental isodisomy (UPiD) for chromosome 5. Conclusion: The abnormal expression of imprinted genes has also been raised as a possible etiology for PMD and similar imbalance may occasionally affect fetal tissue. Such pregnancies offer a rare opportunity to consider the imprinting effects associated with uniparental inheritance in different tissues. http://dx.doi.org/10.1016/j.placenta.2013.06.076 P1.40. RAP1 FUNCTIONS AS A MEDIATOR OF EGF SIGNALING PATHWAY AND A REGULATOR OF EGF RECEPTOR IN EXTRAVILLOUS TROPHOBLAST CELLS INVASION Mikihiro Yoshie , Kazuya Kusama , Kensuke Ohishi , Kazuhiro Tamura , Hirotaka Nishi , Keiichi Isaka , Masahiko Kutsukake , Eiichi Tachikawa 1 Department of Endocrine and Neural Pharmacology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan; Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo, Japan Objective: Extravillous trophoblasts (EVT), which develop from anchoring villi invade into maternal decidua and myometrium and replace with arterial endothelium to establish the interaction between feto-maternal interfaces. Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) bind to the EGF receptor (EGFR) and stimulate EVT invasion through activation of phosphoinositol-3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways. We examined possible roles of small GTP-binding protein Rap1 in EGF and HB-EGFmediated EVT invasion. Methods: Rap1 activation (GTP-Rap1) was examined by pull-down assay after stimulation with EGF or HB-EGF in EVT cell line (HTR8/SVneo). Effect of siRNA-mediated Rap1 knockdown on EGFor HB-EGF-stimulated invasion was assessed by transwell assay. In addition, effect of Rap1 knockdown and enforced expression of Rap1GAP, an inhibitor of Rap1, on the activation of EGF signaling pathways and the expression of EGFR were examined. Results: EGF or HB-EGF activated Rap1 in HTR8/SVneo. EGFor HB-EGFstimulated invasion was significantly abrogated by knocking down Rap1. Silencing of Rap1 expression inhibited EGFor HB-EGF-induced phosphorylation of AKT, ERK1/2 and p38MAPK. Rap1 knockdown significantly decreased EGFR protein level but not its mRNA level. Furthermore, enforced expression of Rap1GAP blocked EGFor HB-EGF-stimulated activation of Rap1 and EGFR-mediated AKT and MAPK signalling pathway. EGFR protein level was also decreased in Rap1GAP overexpressed cells without affecting its mRNA expression. Conclusions: These results suggest that Rap1 may function as a mediator of EGFR-mediated signal transduction and a posttranscriptional modulator of EGFR in the process of EVT invasion. http://dx.doi.org/10.1016/j.placenta.2013.06.077 P1.41. UNFRACTIONATED HEPARIN REVERSES THE INCREASED THROMBIN GENERATION ASSOCIATED WITH DECORIN DEFICIENCY IN FETAL GROWTH RESTRICTION Amy Chui , Tilini Gunatillake , Padma Murthi , Vera Ignjatovic , Paul Monagle , John Whitelock , Shaun Brennecke , Joanne Said 1 Department of Medicine, The University of Melbourne, St Albans, Victoria, Australia; Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, Victoria, Australia; Department of Pediatrics, The