s / Placenta 36 (2015) 469e521 509 endocytosis blocker) and 1 mmol/L nitrobenzylthioinosine (NBTI, an adenosine transport inhibitor), human equilibrative nucleoside transporter 1 (hENT1) immunofluorescence, protein abundance and mRNA expression levels were measured in primary cultures of HUVEC from normal or GD pregnancies coursing without (N or GD groups, respectively) or with OP (OP and GD+OP groups, respectively). Results: hENT1-mediated adenosine uptake was reduced in OP, GD and GD+OP compared with N, a result that was seen even in the presence of the endocytosis inhibitor. hENT1 expression was increased in OP (~1.7 and ~3fold protein abundance and mRNA expression, respectively), but reduced in GD and GD+OP compared with N. Moreover, hENT1 was unable to reach the plasma membrane in OP, meanwhile in GD and GD+OP, hENT1 accumulated in the plasma membrane. Conclusion: GD and OP are associated with alteration in hENT1 recycling, and GD+OP reduces hENT1 expression in HUVEC. PB.9. HUMAN AMNIOTIC EPITHELIAL CELLS: PROLIFERATION AND APOPTOSIS DURING THEIR HEPATIC DIFFERENTIATION J. Maym o , A. P erez-P erez , R. Riedel , B. Maskin , M. Jaime , O. Parolini , V. S anchez-Margalet , C. Varone . Departamento de Quimica Biol ogica, FCEN, UBA, IQUIBICEN, CONICET, Buenos Aires, Argentina; Departamento de Bioquimica M edica y Biologia Molecular, Universidad de Sevilla, Sevilla, Spain; Hospital Alejandro Posadas, Buenos Aires, Argentina; Centro di Ricerca E. Menni e Fondazione Poliambulanza e Istituto Ospedaliero, Brescia, Italy Objective: The placenta and fetal membranes have recently been proposed as an important stem cell source for regenerative medicine. Gestational cells offer considerable advantages over other stem cells such as bone marrow or embryo-derived cells. The collection and use of such tissues have a virtually unlimited potential, an easy access, and minimal ethical and legal barriers. Epithelial amniotic cells (hAECs) can be isolated from the amnion of the human placenta at term. They express embryonic stem cell markers and have the ability to differentiate toward all three germ layers. hAECs are non-tumorigenic and have immunosuppressive properties. These characteristics would make hAECs ideal candidates for tissue engineering and application in regenerative medicine. Hepatic failure is one of the major causes of morbidity and mortality worldwide. Recently, stem cells have been spotlighted as alternative sources of hepatocytes because of their specific potential for differentiation. The aim of this work was to study the proliferation and apoptosis of hAECs, during early and late hepatic differentiation. We also analyzed expression of hepatic markers expression through this process. Methods and results: Hepatic differentiation was assayed by specific factors (EGF + dexamethasone) or by HepG2 conditioned medium (CM). We found a significant increment of caspase-3 fragmentation, after 72 h of CM treatment, measured by western blot. We observed an augmentation in p53 and p21 genes expression and a decline in cyclin D1, measured by qRT-PCR. The opposite effects were observed with the specific factors treatment. We also determined by 3H-thymidine incorporation that EGF significantly increased cell proliferation while CM diminished it. During hAEC differentiation we observed a significant increment in hepatocyte-related gene expression (a-fetoprotein, a1-AT, albumin, CYP7A1) and in albumin expression, measured by qRT-PCR and Western blot, respectively. Conclusions. Our results begin to unravel the molecular and cellular processes that take place during hepatic differentiation of hAECs. PB.10. CAN MAGNESIUM GLUCONATE IMPROVE THE OSMOTIC FRAGILITY OF RED BLOOD CELLS FROM PREECLAMPTIC PREGNANT WOMEN? Cilia Abad, Cindy Ampueda, Sandy Pi~ nero, Delia I. Chiarello, Reinaldo Marin, Fulgencio Proverbio. Laboratory of Cell Bioenergetics, Center of Biophysics and Biochemistry (CBB), Venezuelan Institute for Scientific Research (IVIC), AP 20632, Caracas 1020A, Venezuela Magnesium gluconate (MgGl2) has been proposed as an oral substitute of magnesium sulfate for the treatment of preeclampsia. Our group has shown that preeclampsia is associated with a rise in lipid peroxidation of the placental plasma membranes and red blood cell ghosts. The osmotic fragility of the intact red blood cell is influenced by its membrane characteristics. Evenwhen the erythrocyte is not thought to contribute per se to the etiology of preeclampsia, it may nevertheless be important in the progression of the disease, particularly in view of the occurrence of oxidative stress. Objectives: To determine the effect of MgGl2 on the osmotic fragility of red blood cells from preeclamptic pregnant women. Methodology: Venous blood was drawn from uncomplicated and preeclamptic pregnant women. Red blood cells were incubated for 24 h in the presence or absence of MgGl2. The red cell osmotic fragility was determined. Results and conclusions: We found an increased level of osmotic fragility in red blood cells from preeclamptic pregnant women, as compared to that from uncomplicated pregnant women. Osmotic fragility from red blood cells from preeclamptic pregnant women returned to normal values after 24 h of incubationwith MgGl2. MgGl2 improves the osmotic fragility in red cells from preeclamptic pregnant women. PB.11. HUMAN TROPHOBLAST CELL MIGRATION AND INVASION ARE INDUCED BY ENDOGENOUS VASOACTIVE INTESTINAL PEPTIDE (VIP) THROUGH AUTOCRINE CIRCUITS AND VPAC2 OVEREXPRESSION Vota Daiana , Hauk Vanesa , Toro Ayelen , Grasso Esteban , Paparini Daniel , Ramhorst Rosanna , Varone Cecilia , P erez Leir os Claudia . 1 Laboratorio de Inmunofarmacologia, Dpto. Quimica Biol ogica, IQUIBICEN e CONICET, Facultad de Ciencias Exactas y Naturales-UBA, Argentina; 2 Laboratorio de Fisiologia Molecular Placentaria, Dpto. Quimica Biol ogica, IQUIBICEN e CONICET, Facultad de Ciencias Exactas y NaturalesUBA, Buenos Aires, Argentina The generation of the human maternal-placental interface requires trophoblast differentiation into phenotypes able to migrate and invade the deciduas. VIP is a pleiotropic polypeptide with immunomodulatory effects through VPAC1 and VPAC2 receptors. Previously, we have reported on its immune homeostasis maintenance role at early pregnancy. The expression of VIP in various cell types is induced by growth factors or neurotransmitters and depends on CRE (cAMP responsive elements) and gp130 cytokine (CyRE) sites on its promoter. Objective: To investigate VIP/VPAC2 expression on first trimester cytotrophoblast cells (Swan-71; HTR-8) and its impact on trophoblast cell migration and invasion. Methods: VIP expression was measured by flow cytometry and RT-qPCR; cell migration was determined by wound healing assays and invasiveness in Matrigel-covered transwells. Trophoblast cells were transfected with XtremeGENE HPDNA reagent with VPAC2 or CRE-Luciferase plasmids for 24h prior to the stimuli, normalized to GFP or beta-gal. Results: Endogenous VIP expression was detected in trophoblast cells and its synthesis was induced after 18 h incubation with 10nM VIP (P