Clinical utility of sFlt-1 and PlGF in screening, prediction, diagnosis and monitoring of pre-eclampsia and fetal growth restriction.

Pre-eclampsia (PE) is characterized by placental and maternal endothelial dysfunction, and associated with fetal growth restriction (FGR), placental abruption, preterm delivery and stillbirth. The angiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are altered in pregnancies complicated by placenta-related disorders. In this Review, we summarize the existing knowledge, examining the performance of maternal PlGF, sFlt-1 and the sFlt-1/PlGF ratio for screening PE, predicting development of PE in the short term, diagnosing PE, monitoring established PE and predicting other placenta-related disorders in singleton pregnancy. We also discuss the performance of PlGF and the sFlt-1/PlGF ratio for predicting PE in twin pregnancy. For first-trimester screening in singleton pregnancy, a more accurate way of identifying high-risk women than current practice is to combine maternal PlGF levels with clinical risk factors and ultrasound markers. Later in pregnancy, the sFlt-1/PlGF ratio has advantages over PlGF because it has a higher pooled sensitivity and specificity for diagnosing and monitoring PE. It has clinical value because it can rule out the development of PE in the 1-4-week period after the test. Once a diagnosis of PE is established, repeat measurement of sFlt-1 and PlGF can help monitor progression of the condition and may inform clinical decision-making regarding the optimal time for delivery. The sFlt-1/PlGF ratio is useful for predicting FGR and preterm delivery, but the association between stillbirth and the angiogenic factors is unclear. The sFlt-1/PlGF ratio can be used to predict PE in twin pregnancy, although different sFlt-1/PlGF ratio cut-offs from those for singleton pregnancy should be applied for optimal performance. In summary, PlGF, sFlt-1 and the sFlt-1/PlGF ratio are useful for screening, diagnosing, predicting and monitoring placenta-related disorders in singleton and twin pregnancy. We propose that tests for these angiogenic factors are integrated more fully into clinical practice.© 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Transcriptomic profiling of trophoblast fusion using BeWo and JEG-3 cell lines.

In human placenta, alteration in trophoblast differentiation has a major impact on placental maintenance and integrity. However, little is known about the mechanisms that control cytotrophoblast fusion. The BeWo cell line is used to study placental function, since it forms syncytium and secretes hormones after treatment with cAMP or forskolin. In contrast, the JEG-3 cell line fails to undergo substantial fusion. Therefore, BeWo and JEG-3 cells were used to identify a set of genes responsible for trophoblast fusion. Cells were treated with forskolin for 48 h to induce fusion. RNA was extracted, hybridised to Affymetrix HuGene ST1.0 arrays and analysed using system biology. Trophoblast differentiation was evaluated by real-time PCR and immunocytochemistry analysis. Moreover, some of the identified genes were validated by real-time PCR and their functional capacity was demonstrated by western blot using phospho-specific antibodies and CRISPR/cas9 knockdown experiments. Our results identified a list of 32 altered genes in fused BeWo cells compared to JEG-3 cells after forskolin treatment. Among these genes, four were validated by RT-PCR, including salt-inducible kinase 1 (SIK1) gene which is specifically upregulated in BeWo cells upon fusion and activated after 2 min with forskolin. Moreover, silencing of SIK1 completely abolished the fusion. Finally, SIK1 was shown to be at the center of many biological and functional processes, suggesting that it might play a role in trophoblast differentiation. In conclusion, this study identified new target genes implicated in trophoblast fusion. More studies are required to investigate the role of these genes in some placental pathology.

Soluble fms-like tyrosine kinase-1 to placental growth factor ratio: ruling out pre-eclampsia for up to 4 weeks and value of retesting.

OBJECTIVES: The soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio is generally elevated some time before and at the clinical onset of pre-eclampsia. The PROGNOSIS study validated a sFlt-1/PlGF ratio cut-off of ≤ 38 to rule out the onset of pre-eclampsia within 1 week of testing in women with suspected disease. The aim of this study was to assess the predictive value of the sFlt-1/PlGF ratio to rule out the onset of pre-eclampsia for up to 4 weeks, and to assess the value of repeat measurements. METHODS: This was an exploratory post-hoc analysis of data from the PROGNOSIS study performed in pregnant women aged ≥ 18 years with suspected pre-eclampsia, who were at 24 + 0 to 36 + 6 weeks' gestation at their first clinic visit. Serum samples were collected at the first visit and weekly thereafter. sFlt-1 and PlGF levels were measured using Elecsys® sFlt-1 and PlGF immunoassays. Whether the sFlt-1/PlGF ratio cut-off of ≤ 38 used to rule out the onset of pre-eclampsia within 1 week could predict the absence of pre-eclampsia 2, 3, and 4 weeks post-baseline was assessed. The value of repeat sFlt-1/PlGF testing was assessed by examining the difference in sFlt-1/PlGF ratio 2 and 3 weeks after the first measurement in women with, and those without, pre-eclampsia or adverse fetal outcome. RESULTS: On analysis of 550 women, sFlt-1/PlGF ratio ≤ 38 ruled out the onset of pre-eclampsia 2 and 3 weeks post-baseline with high negative predictive values (NPV) of 97.9% and 95.7%, respectively. The onset of pre-eclampsia within 4 weeks was ruled out with a high NPV (94.3%) and high sensitivity and specificity (66.2% and 83.1%, respectively). Compared with women who did not develop pre-eclampsia, those who developed pre-eclampsia had significantly larger median increases in sFlt-1/PlGF ratio at 2 weeks (∆, 31.22 vs 1.45; P < 0.001) and at 3 weeks (∆, 48.97 vs 2.39; P < 0.001) after their initial visit. Women who developed pre-eclampsia and/or adverse fetal outcome compared with those who did not had a significantly greater median increase in sFlt-1/PlGF ratio over the same period (∆, 21.22 vs 1.40; P < 0.001 at 2 weeks; ∆, 34.95 vs 2.30; P < 0.001 at 3 weeks). CONCLUSION: The Elecsys® immunoassay sFlt-1/PlGF ratio can help to rule out the onset of pre-eclampsia for 4 weeks in women with suspected pre-eclampsia. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

HLA-DR is aberrantly expressed at feto-maternal interface in pre-eclampsia.

In normal pregnancy, villous cytotrophoblast and syncytiotrophoblast do not express HLA Class I and Class II molecules, while invasive extravillous trophoblast only express class I HLA-C and the atypical class Ib antigens, HLA-G, -E and -F. Inadequate maternal tolerance of invasive trophoblast has been proposed as a possible immunologic trigger of poor trophoblast invasion and subsequent occurrence of pre-eclampsia. This study aimed to investigate possible aberrant expression of class II HLA-DR on placentae and syncytiotrophoblast-derived extracellular vesicles (STEVs), obtained by dual placental perfusion, from pre-eclampsia (n = 23) and normal pregnant (n = 14) women. Here we demonstrate that HLA-DR can be detected in syncytiotrophoblast from a significant proportion of pre-eclampsia but not control placentae. HLA-DR was also observed, by flow cytometry, on STEVs and associated with placental alkaline phosphatase to validate their placental origin. HLA-DR positive syncytiotrophoblast was detected in placental biopsies from pre-eclampsia but not normal control cases, using immunohistochemistry. The HLA may be fetal or maternal origin. In the latter case a possible mechanism of acquisition is trogocytosis.

Angiogenic factors: potential to change clinical practice in pre-eclampsia?

Pre-eclampsia is a complex disease with significant maternal and fetal morbidity and mortality. Its syndromic nature makes diagnosis and management difficult. The field is rapidly evolving with the definition of pre-eclampsia being challenged by some organisations, with proteinuria no longer being essential in the presence of other features. In the last decade, angiogenic factors, in particular soluble fms-like tyrosine kinase 1 (sFlt-1), have emerged as important molecules in the pathogenesis of pre-eclampsia. Here we review the most recent evidence regarding the potential of these factors as biomarkers and therapeutic targets for pre-eclampsia. TWEETABLE ABSTRACT: A review of angiogenic factors, sFlt-1 and PlGF, in the diagnosis, prediction and management of pre-eclampsia.

sFlt-1/PlGF ratio test for pre-eclampsia: an economic assessment for the UK.

OBJECTIVES: To assess the economic impact of introducing into clinical practice in the UK the soluble fms-like tyrosine kinase (sFlt-1) to placental growth factor (PlGF) ratio test for guiding the management of pre-eclampsia. METHODS: We used an economic model estimating the incremental value of information, from a UK National Health Service payer's perspective, generated by the sFlt-1/PlGF ratio test, compared with current diagnostic procedures, in guiding the management of women with suspected pre-eclampsia. The economic model estimated costs associated with the diagnosis and management of pre-eclampsia in pregnant women between 24 + 0 and 36 + 6 weeks' gestation, managed in either a 'test' scenario in which the sFlt-1/PlGF test is used in addition to current diagnostic procedures, or a 'no-test' scenario in which clinical decisions are based on current diagnostic procedures alone. Test characteristics and resource use were derived from PROGNOSIS, a non-interventional study in women presenting with clinical suspicion of pre-eclampsia. The main outcome measure from the economic model was the cost per patient per episode of care, from first suspicion of pre-eclampsia to birth. RESULTS: Introduction of the sFlt-1/PlGF ratio test into clinical practice is expected to result in cost savings of £344 per patient compared with a no-test scenario. Savings are generated primarily through an improvement in diagnostic accuracy and subsequent reduction in unnecessary hospitalization. CONCLUSIONS: Introducing the sFlt-1/PlGF ratio test into clinical practice in the UK was shown to be cost-saving by reducing unnecessary hospitalization of women at low risk of developing pre-eclampsia. In addition, the test ensures that those women at higher risk are identified and managed appropriately. © 2016 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Elevated fetal adipsin/acylation-stimulating protein (ASP) in obese pregnancy: novel placental secretion via Hofbauer cells.

CONTEXT AND OBJECTIVE: Obesity in pregnancy is associated with increased risks of obesity in the offspring. We investigated the relationship between obesity in pregnancy and circulating maternal and fetal levels of adipose tissue-derived factors adipsin and acylation stimulating protein (ASP) in lean and obese mothers. DESIGN: Paired peripheral and cord blood samples were taken. Paired fat and placenta tissue were taken for explant culture. Media were assayed for secreted adipsin and ASP. Clinical parameters assayed included fasting insulin, glucose, and adipsin. SETTING: The study was conducted at a university hospital maternity unit. PATIENTS: Patients included 35 lean [body mass index (BMI) 19-25 kg/m(2), mean age 32 years and 39 obese (BMI) > 30 kg/m(2), mean age 32.49 years] pregnant Caucasian women, delivered by cesarean section at term. MAIN OUTCOME MEASURE: Identification of placental macrophages [Hofbauer cells (HBCs)], as a source of adipsin and ASP was determined. RESULTS: HBCs secreted both adipsin and ASP. Cord levels of adipsin (1663.78 ± 52.76 pg/mL) and ASP (354.48 ± 17.17 ng/mL) were significantly elevated in the offspring of obese mothers compared with their lean controls [1354.66 ± 33.87 pg/mL and 302.63 ± 14.98 ng/mL, respectively (P < .05 for both)]. Placentae from obese mothers released significantly more adipsin and ASP than placentae from lean mothers [546.0 ± 44 pg/mL · g vs 284.56 ± 43 pg/mL · g and 5485.75 ± 163.32 ng/mL · g vs 2399.16 ± 181.83 ng/mL · g, respectively (P < .05 for both)]. Circulating fetal adipsin and ASP positively correlated with maternal BMI (r = 0.611, P < .0001, and r = 0.391, P < .05, respectively). Fetal adipsin correlated positively with maternal (r = 0.482, P < .01) and fetal homeostasis model assessment of insulin resistance (r = 0.465, P < .01). CONCLUSIONS: We demonstrate novel secretion of adipsin and ASP by placental HBCs.

Pre-eclampsia is associated with, and preceded by, hypertriglyceridaemia: a meta-analysis.

BACKGROUND: Elevated triglycerides are a feature of the metabolic syndrome, maternal obesity, maternal vasculitis (i.e. systemic lupus erythematosus) and diabetes mellitus. These conditions are all known risk factors for pre-eclampsia. Hypertriglyceridaemia therefore may be associated with pre-eclampsia and indeed this may precede the presence of overt disease. OBJECTIVE: In this study we determine the association between hypertriglyceridaemia and pre-eclampsia in pregnant women. SEARCH STRATEGY: We searched MEDLINE, EMBASE, Web of Science, Excerpta Medica Database, ISI Web of Knowledge, Cumulative Index to Nursing and Allied Health Literature, Cochrane Library from inception until June 2012 and reference lists of relevant studies. SELECTION CRITERIA: Two reviewers independently selected studies on pregnant women where triglycerides were measured and women were followed up until the development of pre-eclampsia or selected on the basis of presence of pre-eclampsia and compared with controls. DATA COLLECTION AND ANALYSIS: We collected and meta-analysed the weighted mean differences (WMDs) of triglyceride levels from individual studies using a random effects model. MAIN RESULTS: We found strong evidence from meta-analysis of 24 case-control studies (2720 women) that pre-eclampsia is associated with higher levels of serum triglycerides (WMD 0.78 mmol/l, 95% confidence interval 0.6-0.96, P < 0.00001). This finding is also confirmed in five cohort studies, that recruited 3147 women in the second trimester before the onset of pre-eclampsia, which proves that hypertriglyceridaemia precedes the onset of pre-eclampsia (WMD 0.24 mmol/l, 95% confidence interval 0.13-0.34, P < 0.0001). AUTHOR'S CONCLUSIONS: Hypertriglyceridaemia is associated with and precedes the onset of pre-eclampsia. Further research should focus on defining the prognostic accuracy of this test to identify women at risk and the beneficial effect of triglyceride-lowering therapies in pregnancy.

Interplay of cAMP and MAPK pathways in hCG secretion and fusogenic gene expression in a trophoblast cell line.

Differentiation of human placental mononuclear trophoblasts into a multinucleate syncytium involves up-regulation of key proteins promoting cell fusion and increased capacity for placental hormonogenesis. It is well established that the activation of adenylyl cyclase leads to increased expression of trophoblast fusogenic gene machinery and human chorionic gonadotropin (hCG) secretion. We used the forskolin-induced syncytialisation of BeWo choriocarcinoma cells as a model to characterise in detail the signalling pathway downstream of adenylyl cyclase. Forskolin treatment induced a rapid and potent ERK1/2 and p38MAPK phosphorylation; this cascade required PKA-AKAP interactions and led to downstream CREB-1/ATF-1 phosphorylation via ERK1/2-dependent but p38MAPK-independent mechanisms. Interestingly both p38MAPK and ERK1/2 were involved in forskolin-induced hCG-secretion, suggesting the presence of additional p38MAPK-dependent but CREB-1/ATF-1-independent pathways. Forskolin treatment of BeWo cells significantly up-regulated the expression of various fusogenic gene mRNAs, including syncytin-1 and -2 (by 3- and 10-fold, respectively) the transcription factors old astrocyte specifically induced substance (OASIS) and glial cells missing a (GCMa) (by 3- and 6-fold, respectively) and the syncytin-2 receptor, major facilitator superfamily domain containing 2 (MFSD2) (by 2-fold). Up-regulation of AKAP79 and AKAP250 (by 2.5- and 4-fold, respectively) was also identified in forskolin-treated BeWo cells. Forskolin effects on all these genes were suppressed by chemical inhibition of p38MAPK whereas only specific genes were sensitive to ERK1/2 inhibition. This data provide novel insights into the signalling molecules and mechanisms regulating fusogenic gene expression by the adenylyl cyclase pathway.

Diurnal variation is lost in preterm deliveries before 28 weeks of gestation.

Preterm delivery is the primary cause of neonatal mortality and morbidity worldwide. Labour at term occurs as a culmination of maturational events in both the fetus and maternal uterus. This process exhibits diurnal variation, with the onset of labour being more common at night. We have confirmed that this diurnal variation is present in gestations between 28 and 36 weeks, but is absent below 28 weeks. We hypothesise that this is because before 28 weeks of gestation, the onset of labour may result from a pathological rather than a physiological process. This may have important implications regarding any pharmacological approach to the prevention and/or treatment of very early preterm labour.

Placental expression of 2,3 bisphosphoglycerate mutase in IGF-II knock out mouse: correlation of circulating maternal 2,3 bisphosphoglycerate and fetal growth.

Bisphosphoglycerate mutase (BPGM) catalyses the formation of 2,3 bisphosphoglycerate (BPG) a ligand of haemoglobin. BPG facilitates liberation of oxygen from haemoglobin at low oxygen tension enabling efficient delivery of oxygen to tissues. We describe expression of BPGM in mouse labyrinthine trophoblasts, located at the maternal-placental interface. Expression is lower in placentae of igf2(+/-) knockout mice, a widely used model of growth restriction, compared to wild type placentae. Circulating maternal BPG increased throughout gestation but this increase was less in wt mothers carrying igf2(+/-) pups than in those carrying exclusively wt pups. This reduction was observed well before term and may contribute to the low birth weight of igf2(+/-) pups. Strikingly, we also measured reductions of fetal and placental weight in wt littermates of igf2(+/-) pups compared to pups developing in an exclusively wt environment. These data suggest that placental expression of BPGM can influence maternal BPG concentrations and supports a hypothesis under which BPG synthesized in the placenta may act on maternal haemoglobin to enhance delivery of oxygen to the developing fetus.

Epithelial ovarian cancer in pregnancy: a review of the literature.

Maternal epithelial ovarian cancer (EOC) is rare, and consequently, management strategies remain unclear due to the low incidence and paucity of reported data. Management depends on gestation, disease stage, future fertility desires, and the mother's wishes to continue pregnancy. Forty-one cases of maternal EOC were identified in the literature. Reporting of clinicopathological variables, treatment regimens, and follow up varied markedly. There are currently no definitive guidelines regarding the management of maternal EOC. Case reporting should contain detailed information on clinicopathological variables, treatment regimens, and maternal and neonatal outcomes. Data centralisation may be beneficial in identifying optimal management strategies in these rare tumours.

Midfoot plantar pressure significantly increases during late gestation.

BACKGROUND: A rise in plantar pressure has been observed in pregnant women with foot pain. The current literature on plantar pressure in pregnancy is sparse. It has been postulated that changes in plantar pressure result from the physiological effects of pregnancy. In this study we aim to quantify the plantar pressure of women in late pregnancy. METHODS: Twenty-two pregnant women undergoing a caesarean section and twenty non-pregnant women were recruited from University Hospital Coventry and Warwickshire between May to June 2007. Plantar pressure measurements were performed using an in-shoe measurement system. The control group was compared with the pregnant group at 38 weeks gestation. A selection of the pregnant group had repeat measurements at 4 months post-partum. The pre and post-partum measurements were also compared. RESULTS: The pregnant group (PG) exerted a significantly higher mean midfoot pressure compared to the non-pregnant control group (CG) (PG=115.5kPa, CG=95.4kPa; p=0.001). Post-partum (PP), there was a significant reduction in the mean and maximum midfoot pressure (mean; PG=111.9kPa, PP=66.2kPa; p<0.001, maximum; PG=184.0kPa, PP=108.3kPa; p<0.001). CONCLUSIONS: The physiological changes in late pregnancy result in an increase in midfoot plantar pressure. This increase resolves post-partum.

Elevated serum levels of visfatin in gestational diabetes: a comparative study across various degrees of glucose tolerance.

AIMS/HYPOTHESIS: Concentrations of visfatin are increased in insulin-resistant conditions, but the relationship between visfatin and insulin and/or insulin resistance indices in pregnancy remains unclear. Insulin resistance in pregnancy is further accentuated in women with gestational diabetes mellitus (GDM). Thus we assessed serum levels of visfatin in pregnant women with varying degrees of glucose tolerance. MATERIALS AND METHODS: Fasting visfatin levels were measured at 28 weeks of gestation in 51 women divided according to their response to a 50-g glucose challenge test (GCT) and a 75-g OGTT: control subjects (n = 20) had normal responses to both a GCT and an OGTT; the intermediate group (IG; n = 15) had a false-positive GCT, but a normal OGTT; the GDM group (n = 16) had abnormal GCTs and OGTTs. RESULTS: There were no age or BMI differences between analysed groups. Across the subgroups there was a progressive increase in glucose and insulin at 120 min of the OGTT (p < 0.01). This was accompanied by an increase in visfatin, from 76.8 +/- 14.1 ng/ml in the control subjects, to 84.0 +/- 14.7 ng/ml in the IG group and 93.1 +/- 12.3 ng/ml in the GDM group (p < 0.01 for GDM vs control subjects). There was a positive correlation between visfatin and fasting insulin (r = 0.38, p = 0.007) and insulin at 120 min of the OGTT (r = 0.39, p = 0.006). CONCLUSIONS/INTERPRETATION: An increase in fasting visfatin, the levels of which correlate with both fasting and post-glucose-load insulin concentrations, accompanies worsening glucose tolerance in the third trimester of pregnancy. However, the significance of these findings, and in particular the role of visfatin in the regulation of insulin sensitivity during pregnancy, remains to be elucidated.

Expression and regulation of prostaglandin E synthase isoforms in human myometrium with labour.

Since the controversies regarding the use of non-steroidal anti-inflammatory drugs (NSAIDs) and selective cyclo-oxygenase (COX)-2 antagonists for the treatment of preterm labour (PTL), more emphasis has been placed on investigating the terminal synthases involved in the production of prostaglandins (PGs) to allow more targeted therapy in PTL. Prostaglandin E(2) (PGE(2)) is synthesized by one of three enzymes, cytosolic prostaglandin E synthase (cPGES), microsomal PGES-1 (mPGES-1) and microsomal PGES-2 (mPGES-2). We have determined (i) the immuno-localization of all three PGES enzymes in lower segment pregnant human myometrium, (ii) the expression of PGES and COX-2 mRNA expression at term and preterm gestation with and without labour and (iii) the effect of interleukin (IL)-1beta on COX-2 and PGES mRNA and protein expression in human myometrial smooth muscle (HMSM) cell cultures. We show mPGES-1 protein located predominantly in myometrial and vascular smooth muscle cells (SMCs), whilst mPGES-2 protein is largely in stromal cells surrounding the SMC and cPGES is diffusely located throughout the myometrium. Expression of mPGES-2 mRNA increased with term labour and PTL and expression of COX-2 and mPGES-1 mRNA with term labour, whereas cPGES expression did not change. IL-1beta stimulated release of PGE(2) by HMSM cells and increased COX-2 and mPGES-1 mRNA and protein expression. Thus, COX-2 expression and mPGES-1 expression are co-ordinately up-regulated in lower segment myometrium with term labour and with IL-1beta treatment in HMSM cells.

Secretion of adiponectin by human placenta: differential modulation of adiponectin and its receptors by cytokines.

AIMS/HYPOTHESIS: Pregnancy, a state of insulin resistance, is associated with elevated levels of cytokines and profound alterations in metabolism. Serum adiponectin, an adipokine with anti-inflammatory and insulin-sensitising properties, has been shown to be lower in patients with gestational diabetes mellitus, a state of greater insulin resistance than normal pregnancies. Hypothesising that the human placenta is a source of adiponectin, we investigated its expression and secretion, and the regulation by cytokines of adiponectin and its receptors. METHODS: Real-time RT-PCR, radioimmunoassay, Western blotting, radioligand binding and immunofluorescent analyses were applied to demonstrate the expression, secretion and functionality of placental adiponectin. RESULTS: Adiponectin gene expression and protein were found in the human term placenta, with expression primarily in the syncytiotrophoblast. RIA of conditioned media from explant experiments revealed that the placenta can secrete adiponectin in vitro. Addition of conditioned media to HEK-293 cells transfected with the gene for adiponectin receptor-1 (ADIPOR1) altered the phosphorylation status of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase, an effect abolished after preabsorption with adiponectin antibody. Cytokines, including TNF-alpha, IFN-gamma, IL-6 and leptin, differentially modulated placental adiponectin receptors as well as adiponectin gene expression and secretion. Interestingly, in placentae from women with gestational diabetes mellitus, we observed significant downregulation of adiponectin mRNA, significant upregulation of ADIPOR1 expression, and a non-significant increase in ADIPOR2 expression. CONCLUSIONS/INTERPRETATION: Our results indicate that the human placenta produces and secretes adiponectin, and that adiponectin and its receptors are differentially regulated by cytokines and their expression altered in women with gestational diabetes mellitus. Collectively, our novel data suggest that adiponectin may play a role in adapting energy metabolism at the materno-fetal interface.

Novel placental expression of 2,3-bisphosphoglycerate mutase.

2,3-Bisphosphoglycerate mutase (2,3-BPGM), an erythroid-expressed enzyme, synthesises 2,3-bisphosphoglycerate (2,3-BPG), the allosteric modulator of haemoglobin. This ligand has a higher affinity for adult haemoglobin than for fetal haemoglobin and differential binding of it facilitates transfer of oxygen between adult and fetal blood by lowering the affinity of adult haemoglobin for oxygen. This paper reports the discovery that 2,3-BPGM is synthesised in non-erythroid cells of the human placenta. Western blot analysis of placental extracts revealed high levels of 2,3-BPGM in the human placenta. Immunohistochemical staining and in situ hybridisation experiments indicated that abundant 2,3-BPGM is present in the syncytiotrophoblast layer of the placental villi at the feto-maternal interface. A cytochemical staining technique showed that the placental 2,3-BPGM is active, indicating that 2,3-BPG is synthesised in the outermost cells of the placenta. These observations demonstrate an unexpected and abundant presence of an enzyme key to oxygen release from adult haemoglobin, at the interface between maternal and fetal circulations.

Emerging technologies for the identification of therapeutic targets for the management of pre-eclampsia.

Pre-eclampsia is a common and serious complication of pregnancy characterised by hypertension and proteinuria. Genetic and environmental factors influence the occurrence and progression of the disease. Emerging experimental systems and increasingly specific analytical methods for the study of differences between normal and pre-eclamptic placentae are close to identifying specific indicators of disease, which may allow early diagnosis and intervention and reveal targets against which therapeutic agents can be developed.