Ex vivo human placental transfer study on recombinant Von Willebrand factor (rVWF).

Deficiency or mutation of von Willebrand factor (VWF) leads to a coagulation disorder (von Willebrand disease; VWD) which requires a lifelong therapy. For avoiding maternal complications treatment may be necessary also in pregnancy, but placental transfer to the fetus might impact its coagulation system and evoke undesired side effects. As VWF is a very large molecule it may be assumed that it does not pass the placental barrier. To prove this hypothesis the materno-fetal transfer of recombinant VWF (rVWF) has been analyzed ex vivo in a total of 21 valid dual side placenta perfusions. Three groups of five placentas each have been perfused with physiological and up to ten-fold increased concentrations of rVWF for 2 h. Six placentas have been used for control perfusions. A series of different control parameters has been assessed for documentation of intactness and functionality of the placenta and the perfusion system. In not a single analysis, independent of time and concentration, rVWF was detected in the fetal circuit. In the maternal circuit VWF concentration decreased slightly during perfusion. These results demonstrate that recombinant VWF does not pass the human placenta.

N-cadherin knockdown leads to disruption of trophoblastic and endothelial cell interaction in a 3D cell culture model - New insights in trophoblast invasion failure.

INTRODUCTION: Trophoblast homing to maternal spiral arteries is mandatory for successful placentation. Cell-cell adhesion molecules regulate this process and adhesion molecule expression is altered in impaired placentation. We hypothesize that, similar to immune cell recruitment, trophoblast cell adherence and rolling are primarily mediated by adhesion molecules like, cadherins, immunoglobulins, selectins and their partnering ligands. Here, the interdependence of adhesion molecule expression in trophoblastic cell lines of diverse origin was investigated in relation to their interaction with endothelial cell networks on Matrigel® co-cultures and the effect of specific adhesion molecule knockdown analyzed. METHODS: Trophoblastic cells were labeled in red and co-cultured with green HUVEC networks on Matrigel®. Association was quantified after collection of fluorescence microscopy pictures using Wimasis® internet platform and software. Expression of adhesion molecules was analyzed by PCR and Western blot, immuno-fluorescence and flow cytometry. The impact of adhesion molecules on trophoblast-endothelial-cell interaction was investigated using siRNA technique. RESULTS: N-cadherin and CD162 were specifically expressed in the trophoblast cell line HTR-8/SVneo, which closely adhere to and actively migrate toward HUVEC networks on Matrigel®. Suppression of N-cadherin led to a significant alteration in trophoblast-endothelial cell interaction. Expression of VE-cadherin in closely interacting trophoblast cells was not confirmed in vitro. DISCUSSION: We identified N-cadherin to mediate specific interaction between HUVEC and the migrating trophoblast cells HTR-8/SVneo in a Matrigel® co-culture model. VE-cadherin contribution could not be confirmed in vitro. Our results support the hypothesis that impaired N-cadherin but not VE-cadherin expression is involved in trophoblast recruitment to the maternal endothelium.

IFPA meeting 2015 workshop report III: nanomedicine applications and exosome biology, xenobiotics and endocrine disruptors and pregnancy, and lipid.

Workshops are an important part of the IFPA annual meeting, as they allow for discussion of specialized topics. At the IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops were related to various aspects of placental biology but collectively covered areas of pregnancy pathologies and placental metabolism: 1) nanomedicine applications and exosome biology; 2) xenobiotics and endocrine disruptors and pregnancy; 3) lipid mediators and placental function.

PP055. Preliminary results of the more prepared study (microparticle orientated risk evaluation in the prediction of preeclampsia among risk gravidas): A multicenter prospective prognostic marker study.

INTRODUCTION: Preeclampsia (PE) is a potentially dangerous pregnancy pathology contributing to a higher worldwide mortality and morbidity. The negative influence of syncytiotrophoblastic microparticles (STBMs) on the placenta and maternal endothelia is thought to play a key role in generating the inflammatory effects that lead to PE symptoms. Doppler sonography of the uterine arteries assists in identifying a risk population, however, the positive predictive value for this method is low. OBJECTIVES: Aim of this study is to evaluate whether STBMs can serve as an accessory marker to conventional Doppler sonography to better identify pregnant women who will actually develop PE. METHODS: Pregnant women between 19-21 gestational weeks (GW) with abnormal uterine perfusion were enrolled into this prospective study. Plasma samples were taken at inclusion (baseline) and at two further visits at 8 week intervals to follow STBM concentration alterations during pregnancy. The primary endpoint assessed is PE and/or hemolysis, elevated liver, low platelets (HELLP) syndrome. Other PE-associated pathologies (intrauterine growth retardation [IUGR], intrauterine fetal demise [IUFD], placental abruption, premature delivery) constitute the secondary endpoints. Maternal STBM concentrations were measured using a home made Enzyme Linked Sorbent Assay (ELSA) which specifically measures STBMs. The receiver operating characteristics (ROC) for baseline measures are graphically displayed and area under curve (AUC) is estimated including 95% confidence levels. RESULTS: Of the 73 women included in the study, 16 developed PE (cases) and 56 did not (control). After analyses of mid-gestational probes, the ROC curve was in close proximity to the line of no-discrimination. CONCLUSION: Our preliminary results indicate that the maternal STBM concentration at mid-gestation does not predict the development of PE or associated pregnancy pathologies. Further analysis is underway to assess whether STBM measurements at later gestational time points can predict PE shortly before onset of disease.