Placental Release Research Articles

74: Maternal obesity is associated with decreased placental cfDNA release in a mouse model

74: Maternal obesity is associated with decreased placental cfDNA release in a mouse model

Resveratrol mitigates trophoblast and endothelial dysfunction partly via activation of nuclear factor erythroid 2-related factor-2

IntroductionMaternal endothelial dysfunction underlying preeclampsia arises from excessive placental release of anti-angiogenic factors, such as soluble fms-like tyrosine kinase-1 (sFlt1), soluble endoglin (sEng) and activin A. Resveratrol, an activator of the nuclear factor erythroid 2-related factor-2 (Nrf2) transcription factor, mediates the gene expression of antioxidant and vasoprotective factors that may counter the endothelial damage imposed by these anti-angiogenic factors. The objective of this study was to assess whether resveratrol could reduce placental oxidative stress and production of anti-angiogenic factors in vitro and/or improve in vitro markers of endothelial dysfunction via Nrf2 activation. MethodWe used in vitro term placental explants to assess the effects of resveratrol on placental oxidative stress and production of sFlt1, sEng and activin A. Using human umbilical vein endothelial cells we investigated the effects of resveratrol on markers of in vitro endothelial dysfunction, including the expression of intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), E-selectin and endothelin-1, and endothelial permeability. To confirm that resveratrol mediated its effects via Nrf2, we examined the impact of resveratrol on the same in vitro markers of endothelial and placental dysfunction following Nrf2 knockdown. ResultsResveratrol significantly decreased placental oxidative stress and the production of sFlt1 and activin A. Resveratrol significantly mitigated tumor necrosis factor–α stimulated endothelial expression of ICAM1, VCAM1, E-selectin and endothelin-1 and prevented an increase in endothelial monolayer permeability. Nrf2 knockdown abolished some of the protective effects of resveratrol on endothelial cells, but not in primary trophoblast cells. ConclusionFeatures of placental and endothelial dysfunction characteristic of preeclampsia are improved by resveratrol in vitro, partially via the modulation of Nrf2.

MPS 13-06 APPLICATION OF NOVEL REDUCED UTERINE PERFUSION PRESSURE (RUPP) MODEL OF PREECLAMPSIA IN C57BL/6J MICE

Objective: Preeclampsia (PE) is a pregnancy-induced hypertension with proteinuria that typically develops after 20 weeks of gestation. A reduction in uterine blood flow causes placental ischemia and placental release of anti-angiogenic factors such as soluble fms-like tyrosine kinase (sFlt-1) followed by PE. Although the reduced uterine perfusion pressure (RUPP) model is widely used in rats, investigating the genetics of PE has been problematic because it has been difficult to make a useful RUPP model in mice. We established novel RUPP model of PE in outbred ICR-strain. The aim of the present study is to develop RUPP model ofC57BL/6J (B6)-strain mice, widely used strain in genetically engineered mice. Design and Method: We bilaterally ligated ovarian vessels distal to ovarian branches, uterine vessels, or both in B6-strain mice at 14.5 days post coitum (dpc). BP, renal phenotype and pregnancy outcome were analyzed. Results: Unlike the RUPP models in ICR-strain mice, ligation of ovarian vessels distal to ovarian branches, uterine vessels without space caused miscarriage in B6-strain mice. We next tied uterine vessels with nylon thread, followed by removal of the thread to provide a small space. This caused significant fetal growth restriction. Conclusions: Pregnancy outcome caused by RUPP in mice was different depending on mouse strains. This model is expected to be useful for investigating pathogenesis of PE in genetically engineered mice and for evaluating new therapies for PE.

OS 21-08 NOVEL REDUCED UTERINE PERFUSION PRESSURE (RUPP) MODEL OF PREECLAMPSIA IN MICE

Objective: Preeclampsia (PE) is a pregnancy-induced hypertension with proteinuria that typically develops after 20 weeks of gestation. A reduction in uterine blood flow causes placental ischemia and placental release of anti-angiogenic factors such as soluble fms-like tyrosine kinase (sFlt-1) followed by PE. Although the reduced uterine perfusion pressure (RUPP) model is widely used in rats, investigating the genetics of PE has been problematic because it has been difficult to make a useful RUPP model in mice. The aim of the present study is to establish a novel PE model using an improved RUPP method in mice. Design and Method: As shown in the Figure 1B, we bilaterally ligated ovarian vessels distal to ovarian branches, uterine vessels, or both in ICR-strain mice at 14.5 days post coitum (dpc). BP, renal phenotype and pregnancy outcome were analyzed. Results: Unlike the RUPP models described in the literature, this model did not constrict the abdominal aorta, which allowed BP to be measured with a tail cuff. RUPP in mice had elevated BP, increased urinary albumin excretion, severe endotheliosis, and mesangial expansion. They also had an increased incidence of miscarriage and premature delivery. Embryonic weight at 18.5 dpc was significantly lower than that in sham mice. The closer to the ligation site the embryos were, the higher the resorption rate and the lower the embryonic weight. The phenotype was more severe in the order of ligation at the ovarian vessels < uterine vessels < both. Conclusions: We developed a novel RUPP mouse model that recapitulates the phenotype of PE. This model is expected to be useful for investigating pathogenesis of PE in genetically engineered mice and for evaluating new therapies for PE.

In vivo uteroplacental release of placental growth factor and soluble Fms-like tyrosine kinase-1 in normal and preeclamptic pregnancies

Preeclampsia is characterized by maternal endothelial dysfunction, which underlies a highly diverse clinical presentation. The pathophysiologic condition remains to be unraveled fully, but interplay between factors that are released from the placenta and maternal vascular vulnerability is likely. An imbalance in circulating angiogenic factors is a prominent feature of preeclampsia; placental growth factor and soluble Fms-like tyrosine kinase 1 have been implemented as biomarkers of placental function and preeclampsia. Their test accuracies are limited in a clinical setting, which urges better insight into their production and removal. Current data suggest that placental growth factor and soluble Fms-like tyrosine kinase 1 are released from the placenta. Both the circulating levels and the placental expression are altered in preeclamptic pregnancies. However, invivo placental release has not been determined in human pregnancies. Moreover, there is evidence that extra-placental tissues might contribute to the circulating levels placental growth factor and soluble Fms-like tyrosine kinase 1 in normal and preeclamptic pregnancies. We aimed to study the invivo placental release of placental growth factor and soluble Fms-like tyrosine kinase 1 by determining the uteroplacental arteriovenous differences in human pregnancies. Further, we investigated whether this release was altered in early-onset preeclampsia compared with control subjects and whether there was a release of placental growth factor and soluble Fms-like tyrosine kinase 1 from maternal systemic endothelium. We conducted a case-control study at Oslo University Hospital and included 23 women with preeclampsia (diagnosis <34 weeks) and 20 control subjects. During cesarean delivery, we sampled blood from 3 vessels simultaneously (uterine vein, radial artery, and antecubital vein). We determined concentrations of placental growth factor and soluble Fms-like tyrosine kinase 1 and calculated the arteriovenous differences. A possible net placental and extra-placental release was evaluated with the use of a Wilcoxon signed rank test. Differences between groups were compared by a Mann-Whitney U-test. The median gestational age at delivery was 33.4 weeks (Q1, 28.3; Q3, 34.4 weeks) in the preeclamptic group and 39.3 weeks (Q1, 39.0; Q3, 39.6 weeks) in the control subjects. Women with preeclampsia had lower plasma concentrations of placental growth factor and higher concentrations of soluble Fms-like tyrosine kinase 1 compared with control subjects (P<.001). There were significant uteroplacental arteriovenous differences of soluble Fms-like tyrosine kinase 1 in preeclampsia (P<.001), but not in the control subjects. The uteroplacental arteriovenous differences of placental growth factor were significant in both groups (P<.001). Despite lower concentrations of plasma placental growth factor in women with preeclampsia, the arteriovenous differences were not significantly different from normal pregnancies (P=.53), even when we corrected for placental weight (P=.79). We found no placental growth factor or soluble Fms-like tyrosine kinase 1 concentration differences between the radial artery and the antecubital vein. Our findings are consistent with a net release of soluble Fms-like tyrosine kinase 1 from the placenta in early-onset preeclampsia. This study demonstrated a placental release of placental growth factor to the maternal circulation but could not demonstrate that this release was impaired in the preeclamptic group. We could not find evidence of systemic endothelial release of placental growth factor and soluble Fms-like tyrosine kinase 1 by analyzing the arteriovenous differences in the forearm. This study contributes to the pathophysiologic understanding of preeclampsia by the use of the clinical setting to test current concepts invivo and underscores that studies of invivo degradation rates of placentally released compounds are needed.

Influence of the duration of calving and obstetric assistance on the placental retention index in Holstein dairy cows.

The aim of this study is to evaluate the influence of duration of calving and obstetric assistance on retained placenta incidence of high milk production Holstein cows. Experimental groups were determined according to the duration of the expulsive phase of calving: 2 h (n = 16), 2-4 h (n = 16) and >4 h (n = 12), and additionally allocated in two sub-groups: spontaneous calving (n = 22) and intervention calving (n = 22). Diagnosis of retained placenta was considered with a threshold of 8 h after the expulsive phase. Cows without obstetric intervention, with labor duration of 2 h, presented reduced time needed for placental release, in comparison to those with obstetric assistance. In the 2-4 h group and >4 h, there was no statistical difference. The 2 h and 2-4 h groups with intervention and the spontaneous >4 h group were considered retained placenta groups. On the other hand, performing obstetric intervention when calving period was superior to 4 h nulled the occurrence of retention of fetal membranes. As a conclusion, obstetric assistance predisposes placental retention to calving with <2 h of duration in dairy cows. Conversely, when calving is more than 4 h, performing fetal extraction has a beneficial influence on preventing retained placenta.

25 Low dose aspirin corrects in vitro the placental cell derived sFlt-1/PlGF imbalance characteristic of preeclampsia

Introduction Preeclampsia (PE) is a multi-system disorder typically involving pregnancy-induced maternal hypertension and proteinuria presenting in the second half of pregnancy. The placenta is the key organ responsible for the pathogenesis of PE, with altered release of placenta-derived anti- (eg sFlt-1) and pro- (eg PlGF) angiogenic proteins implicated in maternal PE pathophysiological events. Epidemiological data indicate that low-dose aspirin (LDA) commenced before 16 weeks gestation is clinically effective in preventing PE, but its mechanism of action is unclear. We hypothesized that the prophylactic efficacy of LDA treatment may be associated with a corrective effect of LDA on the altered release of placenta-derived angiogenic proteins seen in PE pregnancies. Objective To test this hypothesis, we examined the effects of pregnancy sera from normotensive and PE cases with and without LDA on the in vitro production and release of sFlt-1 and PlGF from a trophoblast-derived cell line (BeWo). Methods The effects of LDA (5 μg/mL) following treatment of BeWo cells in vitro with either PE or normotensive serum on the expression of angiogenic proteins sFlt-1 and PlGF were determined using real-time PCR. The secretion of these angiogenic proteins in the conditioned media was screened with a commercially designed protein array. Candidate protein validation was then performed using an ELISA. All experiments were performed in triplicate at least six independent occasions. A p-value Results Angiogenic profiling at the mRNA level identified significantly increased expression of Flt-1 [Normotensive: 1.04 ± 0.03 vs PE: 2.68 ± 0.07, p Conclusion Increased placental release of the anti-angiogenic protein sFlt-1 and reduced placental release of the pro-angiogenic protein PlGF into the maternal circulation are key contributors to the maternal vascular endothelial cell dysfunction that is central to the development of the maternal syndrome of PE. The ability of LDA to rebalance these key angiogenic proteins in an in vitro trophoblast cell-line model may offer an important mechanistic insight at a molecular level regarding the clinical utility of LDA in preventing PE.

Effects of simvastatin, rosuvastatin and pravastatin on soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sENG) secretion from human umbilical vein endothelial cells, primary trophoblast cells and placenta

BackgroundPreeclampsia is associated with the placental release of soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sENG). These anti-angiogenic factors cause hypertension and multi-organ injury. Pravastatin decreases placental secretion of sFlt-1 in vitro and is currently being examined in clinical trials as a potential treatment for preeclampsia. However, it is possible that different classes of statins may be more potent at decreasing sFlt-1 secretion. We compared the relative potency of three different generations of statins on sFlt-1 and sENG secretion from human endothelial cells, trophoblast cells, and placenta explants.MethodsWe performed functional experiments using primary human umbilical vein endothelial cells, trophoblast cells and preterm preeclamptic placental explants to assess the affect of simvastatin, rosuvastatin and pravastatin on sFlt-1 and sENG secretion and compared the relative potency of each statin at reducing these factors (Inhibitory Concentration 50). Furthermore we assessed the effect of each statin on the antioxidant and cytoprotective enzyme, heme-oxygenase 1.ResultsAll statins reduced sFlt-1 secretion from endothelial cells, trophoblasts and preterm preeclamptic placental explants. Simvastatin was the most potent inhibitor of sFlt-1 secretion from endothelial cells (IC 50 3.2 μM), trophoblast cells (IC 50 61.4 μM) and placental explants. Simvastatin was 28 times and 3 times more potent at reducing sFlt-1 secretion from endothelial cells and 85 times and 33 times more potent at reducing sFlt-1 secretion from trophoblast cells than pravastatin or rosuvastatin respectively.All statins increased sENG secretion from endothelial cells however did not change secretion from placental explants.While all statins up-regulated heme-oxygenase 1 in endothelial cells, only simvastatin up-regulated its expression in placenta from patients with preterm preeclampsia.ConclusionSimvastatin may be a more potent inhibitor of sFlt-1 secretion from endothelial cells, trophoblast cells and placenta from women with preterm preeclampsia than either pravastatin or rosuvastatin.

Reduced Uterine Perfusion Pressure (RUPP) Model of Preeclampsia in Mice

Preeclampsia (PE) is a pregnancy-induced hypertension with proteinuria that typically develops after 20 weeks of gestation. A reduction in uterine blood flow causes placental ischemia and placental release of anti-angiogenic factors such as sFlt-1 followed by PE. Although the reduced uterine perfusion pressure (RUPP) model is widely used in rats, investigating the role of genes on PE using genetically engineered animals has been problematic because it has been difficult to make a useful RUPP model in mice. To establish a RUPP model of PE in mice, we bilaterally ligated ovarian vessels distal to ovarian branches, uterine vessels, or both in ICR-strain mice at 14.5 days post coitum (dpc). Consequently, these mice had elevated BP, increased urinary albumin excretion, severe endotheliosis, and mesangial expansion. They also had an increased incidence of miscarriage and premature delivery. Embryonic weight at 18.5 dpc was significantly lower than that in sham mice. The closer to the ligation site the embryos were, the higher the resorption rate and the lower the embryonic weight. The phenotype was more severe in the order of ligation at the ovarian vessels < uterine vessels < both. Unlike the RUPP models described in the literature, this model did not constrict the abdominal aorta, which allowed BP to be measured with a tail cuff. This novel RUPP model in mice should be useful for investigating the pathogenesis of PE in genetically engineered mice and for evaluating new therapies for PE.

Apoptose e maturação placentária bovina: um estudo imunohistoquímico e morfométrico

Resumo: A liberação da placenta após o parto envolve a perda da adesão materno-fetal e ocorre somente após a maturação completa do placentoma, que está relacionada com a diminuição da celularidade dos tecidos fetal e materno. A apoptose é requerida tanto para a maturação quanto para a liberação normal da placenta após o parto. O objetivo do presente estudo foi avaliar a ocorrência de apoptose em amostras de placenta de vacas em diferentes fases de gestação. Amostras de placentomas de 15 vacas saudáveis com 4 (n=5), 6 (n=5) e 9 (n=5) meses de gestação foram colhidas e processadas rotineiramente para a histologia, imunoistoquímica e histoquímica. As lâminas obtidas foram coradas em HE, Picrosirius Red e submetidas à análise imunoistoquímica das proteínas Caspase 3, Caspase 8, Bax e Bid. O aumento no número de vasos não necessariamente se associou ao aumento do calibre destes durante a evolução da gestação. Os resultados de histomorfometria revelaram aumento da marcação para Bax e Caspases 3 e 8 em células trofoblásticas binucleadas no final da gestação, enquanto o Bid se manteve sem alteração significativa. A histomorfometria das células trofoblásticas mononucleadas revelou expressão alta para Bax no início de gestação, com diminuição aos 6 meses de gestação e aumento das imunomarcações para Caspases 3 e 8, e Bid com o avanço gestacional. Os colágenos tipo I e III não aumentaram do terço médio ao final da gestação, o que é importante para a diminuição da adesão materno-fetal. Esses resultados confirmam que as Caspases 3 e 8, e o Bax estão envolvidos nos mecanismos de ativação da apoptose pela via intrínseca mitocondrial e/ou extrínseca ao longo da gestação em células trofoblásticas binucleadas, e que nas células trofoblásticas mononucleadas o Bax deixa de ser importante, enquanto o Bid e as Caspases 3 e 8 se tornam os mais significativos.

Maternal obesity alters the apelinergic system at the feto-maternal interface

Apelin and its receptor APJ have been implicated in pathologies including cardiovascular disease, diabetes and obesity. Little is known about the function of the apelinergic system during gestation. We evaluated in mice this system at the feto-maternal interface in insulin-resistant obese female (HF) mice. Maternal apelinemia was decreased at term and fetal apelinemia was sixfold higher than maternal level. Ex-vivo, the placenta releases apelin at E12.5 and E18.5. In HF pregnant mice at term, apelinemia as well as placental apelin and APJ mRNA levels were increased whereas placental release of apelin was drastically reduced compared to controls.

Increased risk for the development of preeclampsia in obese pregnancies: weighing in on the mechanisms

Preeclampsia (PE) is a pregnancy-specific disorder typically presenting as new-onset hypertension and proteinuria. While numerous epidemiological studies have demonstrated that obesity increases the risk of PE, the mechanisms have yet to be fully elucidated. Growing evidence from animal and human studies implicate placental ischemia in the etiology of this maternal syndrome. It is thought that placental ischemia is brought about by dysfunctional cytotrophoblast migration and invasion into the uterus and subsequent lack of spiral arteriole widening and placental perfusion. Placental ischemia/hypoxia stimulates the release of soluble placental factors into the maternal circulation where they cause endothelial dysfunction, particularly in the kidney, to elicit the clinical manifestations of PE. The most recognized of these factors are the anti-angiogenic sFlt-1 and pro-inflammatory TNF-α and AT1-AA, which promote endothelial dysfunction by reducing levels of the provasodilator nitric oxide and stimulating production of the potent vasoconstrictor endothelin-1 and reactive oxygen species. We hypothesize that obesity-related metabolic factors increase the risk for developing PE by impacting various stages in the pathogenesis of PE, namely, 1) cytotrophoblast migration and placental ischemia; 2) release of soluble placental factors into the maternal circulation; and 3) maternal endothelial and vascular dysfunction. This review will summarize the current experimental evidence supporting the concept that obesity and metabolic factors like lipids, insulin, glucose, and leptin affect placental function and increase the risk for developing hypertension in pregnancy by reducing placental perfusion; enhancing placental release of soluble factors; and by increasing the sensitivity of the maternal vasculature to placental ischemia-induced soluble factors.

Heme Oxygenase-1 Is Not Decreased in Preeclamptic Placenta and Does Not Negatively Regulate Placental Soluble fms-Like Tyrosine Kinase-1 or Soluble Endoglin Secretion.

Elevated placental release of the antiangiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sENG), is central to the pathophysiology of preeclampsia. It is widely accepted that heme oxygenase-1 (HO-1) is decreased in preeclamptic placenta and negatively regulates sFlt-1 and sENG production. We set out to verify these contentions. There was no difference in HO-1 mRNA or protein levels in preterm preeclamptic placentas (n=17) compared with gestationally matched controls (n=27). In silico analysis of microarray studies did not identify decreased placental HO-1 expression in preeclamptic placenta. Silencing HO-1 in primary trophoblasts did not affect sFlt-1 protein secretion after 24 or 48 hours. Silencing nuclear factor (erythroid-derived 2)-like 2 (transcription factor that upregulates HO-1) in trophoblasts also did not affect sFlt-1 secretion. Administering tin protoporphyrin IX dichloride (HO-1 inhibitor) or cobalt protoporphyrin (HO-1 inducer) into placental explants did not affect sFlt-1 or sENG secretion. Silencing HO-1 in 2 types of primary endothelial cells (human umbilical vein endothelial and uterine microvascular endothelial cells) significantly increased sFlt-1 secretion but not sENG secretion. However, HO-1 silencing selectively increased mRNA expression of sFlt-1 i13 (generically expressed sFlt-1 variant) but not of sFlt-1 e15a (sFlt-1 variant mainly expressed in placenta). Furthermore, adding tin protoporphyrin IX dichloride decreased sFlt-1, whereas adding HO-1 inducers (cobalt protoporphyrin, dimethyl fumarate, and rosiglitazone) either had no effect or increased sFlt-1 or sENG secretion (these trends are opposite to what is expected). We conclude that HO-1 expression is not decreased in preeclamptic placenta and HO-1 does not negatively regulate placental sFlt-1 and sENG secretion in placental or endothelial cells.

The near term shift of syndecan protein to an epithelial localization suggests an involvement in placental maturation and release of bovine fetal membranes

The near term shift of syndecan protein to an epithelial localization suggests an involvement in placental maturation and release of bovine fetal membranes

Additive effects of maternal depressive symptoms during pregnancy and three years after childbirth on offspring psychiatric symptoms in early childhood

Introduction: Themechanisms underlying the effects ofmaternal prenatal stress on foetal development remain elusive. One hypothesis is that maternal stress leads to increased cortisol blood concentrations, which in turn may overstimulate the secretion of placental corticotropin releasing hormone (CRH) into the foetal circulation. However, whether acute stress-induced rises in maternal cortisol affect foeto-placental CRH levels is unknown. We therefore aimed at exploring the association between the acutematernal psychobiological stress response as well as chronic maternal stress perception and foeto-placental CRH levels. Methods: We examined thirty-four healthy pregnant women (37.4±4.0 years) undergoing second-trimester amniocentesis. The amniocentesis served as a naturalistic stress situationduringwhich we repeatedly obtained questionnaires on maternal acute stress perception and saliva samples for cortisol analysis. We furthermore monitored maternal cardiac activity continuously (i.e., heart rate, heart rate variability). Thewomen also responded to the social overload scale of the Trier Inventory of Chronic Stress (Schultz and Schlotz, 1999). CRH levels were analysed from an amniotic fluid aliquot. Results: The amniocentesis induced significant changes in maternal stress perception, salivary cortisol, and cardiac activity. No significant association between the acute psychobiological stress response and amniotic CRH was apparent (all p> .10). However, maternal chronic social overload was positively correlated with CRH levels (Kendall’s tau= .34, p= .02). Conclusions: The current findings provide evidence thatmaternal chronic stress affects placental CRH secretion. However, we cannot exclude that a different or longer timeframe might be required to detect an association between acute maternal stress and foeto-placental CRH. Further studies are called for.

Effects of Pravastatin on Human Placenta, Endothelium, and Women With Severe Preeclampsia.

Preeclampsia is a major pregnancy complication where excess placental release of soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin causes maternal endothelial and multisystem organ injury. Clinical trials have commenced examining whether pravastatin can be used to treat preeclampsia. However, the preclinical evidence supporting pravastatin as a treatment is limited to animal models, with almost no studies in human tissues. Therefore, we examined whether pravastatin reduced sFlt-1 and soluble endoglin secretion and decreased endothelial dysfunction in primary human tissues. Pravastatin reduced sFlt-1 secretion from primary endothelial cells, purified cytotrophoblast cells, and placental explants obtained from women with preterm preeclampsia. It increased soluble endoglin secretion from endothelial cells but did not change secretion from placental explants. The regulation of sFlt-1 by pravastatin seemed to be mediated via the 3-hydroxy-3-methylglutaryl-coenzyme A reductase cholesterol synthesis pathway. Pravastatin also reduced markers of endothelial dysfunction, including vascular cell adhesion molecule-1 expression and leukocyte adhesion on endothelial cells and increased endothelial cell migration and invasion. We also treated 4 patients with preterm preeclampsia presenting at <30 weeks of gestation with daily pravastatin. Pravastatin seemed to stabilize blood pressure, proteinuria, and serum uric acid levels. Furthermore, serum sFlt-1 levels decreased. We collected the placentas at delivery and found that pravastatin reduced sFlt-1 secretion. These results indicate that pravastatin reduced sFlt-1 and soluble endoglin production and decreased endothelial dysfunction in primary human tissues. We also present pilot data, suggesting that pravastatin can stabilize clinical and biochemical features of preterm preeclampsia. Our data obtained in human tissues support the concept that pravastatin is a candidate therapeutic for preeclampsia. URL: http://www.anzctr.org.au. Unique identifier: ACTRN12613000268741.

Fetal exposure to placental corticotropin-releasing hormone (pCRH) programs developmental trajectories

The maternal endocrine stress system is profoundly altered during the course of human pregnancy. The human placenta expresses the genes for CRH as early as the seventh week of gestation and it is the expotential increase in placental CRH (pCRH) over the course of human gestation that is responsible for the greatest modification in the maternal stress system. The bi-directional placental release of hormones into the maternal and fetal compartments has profound influences for both. The influential Fetal Programming model predicted that early or fetal exposures to maternal signals of threat or adverse conditions have lifelong consequences for health outcomes. A basic assumption of this model was that developing organisms play a dynamic role in their own construction. Data are reviewed and new data are presented that elevated pCRH over the course of human gestation plays a fundamental role in the organization of the fetal nervous system, modifies birth phenotype (the timing of the onset of spontaneous labor and delivery), and influences developmental, temperamental and metabolic trajectories. Evidence for sex differences and conserved function across species is presented. Finally, a model is presented that proposes several pathways that pCRH can program risk for health and disease.

18-OR

Objectives While obesity is a major risk factor for preeclampsia, which is new-onset hypertension in pregnancy, the mechanisms linking obesity and hypertension during preeclampsia are not understood. Hypertension in preeclampsia is associated with placental ischemia-induced release of factors such as anti-angiogenic sFlt-1 into the maternal circulation which antagonizes vascular endothelial growth factor (VEGF) and promotes endothelial dysfunction. The purpose of this study was to determine the effect of obesity on angiogenic factors and endothelial function in obese melanocortin 4 receptor (MC4R) knockout rats (MC4R+/−, n = 4–9) and lean control MC4R+/+ rats ( n = 4–8). Methods EchoMRI for measuring total body fat mass; carotid arterial catheters for measuring mean arterial blood pressure; ELISAs; wire myography. Results At gestational day (GD) 18, body weight (362 ± 6 vs. 336 ± 5 g) and total body fat mass (62 ± 6 vs. 45 ± 5 g) were greater ( P P P P Conclusions These data indicate that during normal pregnancy, obesity is associated with greater circulating VEGF levels and nitric oxide-dependent vasorelaxation in resistance arteries. Because soluble factors from the ischemic placental target reduce nitric oxide bioavailability, we propose that the hypertensive and endothelial dysfunction responses to reductions in uterine perfusion may be exaggerated in obese pregnant animals. Funding: HL105324, HL51971. Disclosures F.T. Spradley: None. A.C. Palei: None. J.P. Granger: None.

262: Heparin stimulates placental release and increases circulating levels of amyloid-like aggregates in women with prophylactic anticoagulation

262 Heparin stimulates placental release and increases circulating levels of amyloid-like aggregates in women with prophylactic anticoagulation Katherine Rodewald Millen, Catalin Buhimschi, Guomao Zhao, Sammy Tabbah, Stephen Thung, Michael Paidas, Edmund Funai, Irina Buhimschi The Ohio State University College of Medicine, Department of Obstetrics and Gynecology, Columbus, OH, Nationwide Children’s Hospital, Center for Perinatal Research, Columbus, OH, Yale University School of Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, New Haven, CT OBJECTIVE: Heparin interacts with amyloidogenic proteins, modifying their propensity to aggregate. Heparin’s stabilizing fibril property carries a powerful anti-cytotoxic effect. The clinical implication of these observations is that heparin could serve as a potential therapeutic target for severe placental-mediated pregnancy complications. We sought to determine whether heparin alters maternal circulating levels of amyloid-like aggregates in women receiving anticoagulation during pregnancy as measured by Thioflavin T (ThT) fluorescence. STUDY DESIGN: We analyzed serial serum samples from 42 pregnant women followed longitudinally across gestation. Heparin anticoagulation was clinically indicated in 21 women with a history of thrombophilia and/or antiphospholipid syndrome. Each woman was matched to a control (CRL) that delivered at term without complications (n1⁄421). Anticoagulation level was assessed by Factor Xa activity. To determine whether heparin’s effects were confounded by the disease, we used a villous explant system (term CS, n1⁄45) to measure levels of ThT-induced fluorescence preand postincubation with either unfractionated (UFH) or low-molecular weight (LMW) heparin, at doses relevant for human treatment (0.5, 5, 50 U/mL). RESULTS: 1) In-vivo, beyond 34 weeks, heparin significantly increased serum ThT-induced fluorescence (P<0.001, Figure A); 2) A heparin typeand dose-dependent increase in ThT-induced fluorescence was observed in-vitro for both UFH and LMW heparin (P1⁄40.004, Figure B). CONCLUSION: Cumulative exposure to heparin results in increased ThT-induced fluorescence, both in-vivo and in-vitro. Our study provides evidence that a potential beneficial effect of anticoagulation could be the result of improved protein folding in the placenta.

The CCR5Δ32 polymorphism as a pre-eclampsia susceptibility marker: an evaluation in Brazilian women

a cluster with other chemokine receptor genes [5]. the CCr5Δ32 (rs333) is an allelic variant of which 32 bp were deleted in the coding region resulting in a nonfunctional receptor. First described as a co-receptor for hIV-1 virus infection, this variant was also associated to several inflam-matory conditions (see Vargas et al. for a review). homozy-gous individuals for CCr5Δ32 do not express a functional protein, while heterozygous may express low amounts of the functional receptor when compared to the wild-type homozygous individuals.Pre-eclampsia, for instance, is one of the most common pregnancy complications and along with other hyperten-sive disorders, is a major contributor to maternal mortal-ity worldwide [6]. Despite its severity, the etiology of Pe is not fully elucidated, affecting 5–10% of all pregnan -cies globally. In Brazil, this disease accounts for more than 7 % of maternal–fetal mortality. thus, the understanding of such phenomenon is of great importance to elucidate the immunological mechanisms involved during the gesta-tional period. Pe is characterized, among others symptoms, by the occurrence of hypertension (diastolic blood pres-sure of ≥90 mm hg), edema and substantial proteinuria (≥300 mg in 24 h) at or after 20 weeks of gestation [7]. 6, Furthermore, Pe is characterized by events of endothelial dysfunction and excessive inflammation, mainly in the first trimester of pregnancy [6]. One of the pathophysiologi-cal mechanisms of Pe is a failure to develop an adequate blood supply to the placenta, leading to placental oxidative stress and excessive release of placental factors in mater-nal circulation. In addition, an inadequate trophoblast inva-sion results in an incomplete remodeling of uterine spiral arteries, being the main cause of placental ischemia in PeImmunogenetics laboratory, Department of[8, 9]. It is known that genetic factors play a role in pre-eclampsia. Also, an immune unbalance in pre-eclampsia has been reported. Altered cytokine production and marked Dear Sir,We read with interest the manuscript by Gurdol et al. [1] that suggested a protective effect of the CCr5Δ32 poly-morphic variant of the CCr5 gene in inflammation asso-ciated to pre-eclampsia (Pturkish women. e) in the CCr5Δ32 allelic variant was observed in a lower fre-quency among pre-eclamptic women as compared to con-trols, and therefore the authors suggested that its presence conferred protection against this disease. As it is well-estab-lished, chemokines are chemotactic cytokines involved in several cellular processes including innate immunity, cellu-lar recruitment, cell activation, induction of adhesion mol-ecules expression and inflammation [2]. Chemokine recep-tors (CCr) are members of the G protein-coupled receptors and present seven transmembrane domains, being con-sidered as important determinants of early inflammatory responses [2]. Different works already evaluated the asso-ciation of CCr genes polymorphisms as well as cytokine levels and the inflammatory state and pathogenesis of pre-eclampsia [3, 4]. CCr5 is a member of the CC chemokine receptors mainly expressed in immune system cells, such as macrophages and t lymphocytes. CCr5 plays an impor-tant role in migration of immune cells to inflammatory sites. It has been shown that chemokines are essential for the regulation of immune responses, being crucial in patho-genesis of both autoimmune and hypersensitivity-based diseases [2t]. he gene encoding CCr5 (