Relapses in Illicit Drug Use Among Probationers: Results in a Risk Group of Public Health Services in Bavaria

Objective: We aimed to identify in this study time trends of relapses in the illicit consumption of narcotics in a special at-risk population of former drug users under a public health perspective. Methods: In a pooled dataset of 14 consecutive calendar years (2006-2019), the use of seven different narcotic substances was studied in 380 persons with a total of 2,928 urine samples which were analyzed using a valid marker system for narcotic residues. Results: During the entire observation period, the relapse rate for cannabinoids and opiates was the highest despite abstinence requirements. It was noticeable that the relapses across all narcotics groups occurred primarily during the first 3 years of the probation period (90%) with a decrease in illegal consumption during the following years of the observation period. Conclusion: Special attention should be paid to probationers at the beginning of the probation period to develop more effective prevention strategies for substance abstinence by all involved actors in public health services.

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.

Hofbauer cells of M2a, M2b and M2c polarization may regulate feto-placental angiogenesis

The human placenta comprises a special type of tissue macrophages, the Hofbauer cells (HBC), which exhibit M2 macrophage phenotype. Several subtypes of M2-polarized macrophages (M2a, M2b and M2c) exist in almost all tissues. Macrophage polarization depends on the way of macrophage activation and leads to the expression of specific cell surface markers and the acquisition of specific functions, including tissue remodeling and the promotion of angiogenesis. The placenta is a highly vascularized and rapidly growing organ, suggesting a role of HBC in feto-placental angiogenesis. We here aimed to characterize the specific polarization and phenotype of HBC and investigated the role of HBC in feto-placental angiogenesis. Therefore, HBC were isolated from third trimester placentas and their phenotype was determined by the presence of cell surface markers (FACS analysis) and secretion of cytokines (ELISA). HBC conditioned medium (CM) was analyzed for pro-angiogenic factors, and the effect of HBC CM on angiogenesis, proliferation and chemoattraction of isolated primary feto-placental endothelial cells (fpEC) was determined in vitro. Our results revealed that isolated HBC possess an M2 polarization, with M2a, M2b and M2c characteristics. HBC secreted the pro-angiogenic molecules VEGF and FGF2. Furthermore, HBC CM stimulated the in vitro angiogenesis of fpEC. However, compared with control medium, chemoattraction of fpEC toward HBC CM was reduced. Proliferation of fpEC was not affected by HBC CM. These findings demonstrate a paracrine regulation of feto-placental angiogenesis by HBC in vitro. Based on our collective results, we propose that the changes in HBC number or phenotype may affect feto-placental angiogenesis.

Evidence from the very beginning: endoglandular trophoblasts penetrate and replace uterine glands in situ and in vitro

STUDY QUESTION

How is histiotrophic nutrition of the embryo secured during the first trimester of pregnancy?

SUMMARY ANSWER

Rather than specifically focusing on invasion into spiral arteries, extravillous trophoblasts also invade into uterine glands (endoglandular trophoblast) from the very beginning and open them toward the intervillous space.

WHAT IS KNOWN ALREADY

Extravillous trophoblasts can be found in close contact and within the lumen of uterine glands, sometimes replacing glandular epithelial cells.

STUDY DESIGN, SIZE, DURATION

As well as extensive screening of specimens from first trimester placentation sites in situ we used a previously established three-dimensional co-culture in vitro model system of first trimester villous explants with non-invaded decidua parietalis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

First trimester placentas were obtained from elective terminations of pregnancies (n = 48) at 5-11 weeks of gestational age. A subset was processed for confrontation co-culture (n = 31). Invaded decidua basalis was obtained from 20 placentas. All tissues were sectioned, subsequently immunostained and immunodoublestained with antibodies against keratin 7 (KRT7), major histocompatibility complex, class I, G (HLA-G), matrix metallopeptidase 9 (MMP9), von Willebrand factor (VWF) and the appropriate Immunoglobulin G (IgG) negative controls. Replacement of endothelial/epithelial cells by extravillous trophoblasts was quantified semi-quantitatively. Additionally, hematoxylin and eosin-stained archival specimens from early implantation sites were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

The earliest available specimen was from around Day 10 after conception; already at this stage trophoblasts had penetrated into uterine glands and had started to replace the epithelium of the glands. Endoglandular trophoblasts replaced uterine glands in vitro and in situ and could be found in the lumen of invaded glands. Quantitative analysis revealed significantly more replacement of epithelial cells in glands (63.8 ± 22.1%) compared with endothelial cells in vessels (26.4 ± 8.8%). Accumulated detached glandular epithelial cells could be repeatedly observed in the lumen of invaded glands. Additionally, in areas of trophoblast invasion the glandular epithelium seemed to be completely disintegrated compared with glandular epithelium in the non-invaded parts of the decidua. Whole tissue specimens were used in vitro and in situ instead of cell lines; these systems mostly maintain the context of the in vivo situation.

LIMITATIONS, REASONS FOR CAUTION

This is a descriptive study supported by in vitro experiments. However, a histological section will always only be a snapshot and quantification from histological sections has its limitations.

WIDER IMPLICATIONS OF THE FINDINGS

This study further strengthens the hypothesis of histiotrophic nutrition of the embryo prior to the establishment of the maternal blood flow toward the placenta. Invasion of uterine glands by endoglandular trophoblasts may have more impact on the outcome of early pregnancy than assumed up to now.

Expression of serum amyloid A4 in human trophoblast-like choriocarcinoma cell lines and human first trimester/term trophoblast cells

Trophoblast invasion into uterine tissues represents a hallmark of first trimester placental development. As expression of serum amyloid A4 (SAA4) occurs in tumorigenic and invasive tissues we here investigated whether SAA4 is present in trophoblast-like human AC1-M59/Jeg-3 cells and trophoblast preparations of human first trimester and term placenta. SAA4 mRNA was expressed in non-stimulated and cytokine-treated AC1-M59/Jeg-3 cells. In purified trophoblast cells SAA4 mRNA expression was upregulated at weeks 10 and 12 of pregnancy. Western-blot and immunohistochemical staining of first trimester placental tissue revealed pronounced SAA4 expression in invasive trophoblast cells indicating a potential role of SAA4 during invasion.

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SAA4 mRNA is expressed in Jeg-3 and AC1-M59 cells.

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SAA4 mRNA is expressed in first trimester/term trophoblast cells.

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SAA4 mRNA is upregulated at pregnancy week 10 and 12.

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SAA4 protein is present in interstitial, intramural and intraluminal trophoblast cells.

Distribution of decidual natural killer cells and macrophages in the neighbourhood of the trophoblast invasion front: a quantitative evaluation

STUDY QUESTION

Do decidual natural killer (dNK) cells and decidual macrophages (dMph) become enriched in the vicinity of the trophoblast invasion front?

SUMMARY ANSWER

Morphometric image analysis and areal cell density calculations, which excluded observer bias, showed an enrichment of decidual leukocytes in the neighbourhood of the trophoblast invasion front.

WHAT IS KNOWN ALREADY

In previous studies, the number of decidual leukocytes was visually counted in medium- or high power fields. These methods, however, cannot reveal the exact spatial relationship between leukocytes and invasive trophoblast cells, and are therefore prone to subjective errors. Thus, a more objective approach is required.

STUDY DESIGN, SIZE, DURATION

Applying a new method of morphometric image analysis, leukocyte populations were studied in human tissue fragments derived from first trimester placentation sites (n = 7) as well as in co-cultures of first trimester decidual tissue with placental villi of the same pregnancy representing an appropriate in vitro model of trophoblast invasion (n = 15).

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

First trimester decidual tissue was obtained from women undergoing elective terminations of pregnancy at 7-10 weeks of gestational age. Tissue sections were double-stained immunohistochemically for markers of dNK cells or dMph on one hand, and for invasive extravillous trophoblast cells on the other. To analyse the distribution of leukocytes, distinct cell compartments as well as cell neighbourhood areas were defined. Finally, relative areal cell densities were calculated and these data were compared with those of an in vitro model of trophoblast invasion as well as with tissue fragments derived from decidua parietalis without trophoblast cells.

MAIN RESULTS AND THE ROLE OF CHANCE

At first trimester placentation sites, a higher density of dNK cells as well as of dMph was found in close proximity to the invasive trophoblast (P ≤ 0.01), compared with the average areal cell density of decidual leukocytes in the tissue with exclusion of the trophoblast. The highest areal cell density of leukocytes was determined up to a distance of 20 μm from the trophoblast cells, whereas in more distant regions it was even lower than average, indicating a migration of these leukocytes towards the trophoblast invasion front. In the three-dimensional co-culture model, however, we found an enrichment of dMph (P ≤ 0.01) but not of dNK cells (P > 0,05) in the neighbourhood of the invasive trophoblast.

LIMITATIONS, REASONS FOR CAUTION

The morphometric image analysis depends on intense immunohistochemical staining that is free of background and cross-reactivity.

WIDER IMPLICATIONS OF THE FINDINGS

The presented method will be useful not only for the investigation of recurrent miscarriage but also in the fields of tumour immunology and inflammation.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the European Commission (Network of Excellence 'The Control of Embryo Implantation (EMBIC)', FP6-512040, lead researcher: P.S.), and by the Franz Lanyar Foundation of the Medical University of Graz, Austria (Grant #347). None of the authors declared a conflict of interests.

The placental exposome: placental determinants of fetal adiposity and postnatal body composition

Offspring of obese and diabetic mothers are at increased risk of being born with excess adiposity as a consequence of their intrauterine environment. Excessive fetal fat accretion reflects additional placental nutrient transfer, suggesting an effect of the maternal environment on placental function. High plasma levels of particular nutrients in obese and diabetic mothers are likely to be the important drivers of nutrient transfer to the fetus, resulting in excess fat accretion. However, not all offspring of obese and diabetic mothers are born large for gestational age and the explanation may involve the regulation of placental nutrient transfer required for fetal growth. The placenta integrates maternal and fetal signals across gestation in order to determine nutrient transfer rate. Understanding the nature of these signals and placental responses to them is key to understanding the pathology of both fetal growth restriction and macrosomia. The overall effects of the maternal environment on the placenta are the product of its exposures throughout gestation, the 'placental exposome'. Understanding these environmental influences is important as exposures early in gestation, for instance causing changes in the function of genes involved in nutrient transfer, may determine how the placenta will respond to exposures later in gestation, such as to raised maternal plasma glucose or lipid concentrations. Longitudinal studies are required which allow investigation of the influences on the placenta across gestation. These studies need to make full use of developing technologies characterising placental function, fetal growth and body composition. Understanding these processes will assist in the development of preventive strategies and treatments to optimise prenatal growth in those pregnancies at risk of either excess or insufficient nutrient supply and could also reduce the risk of chronic disease in later life.

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells

BACKGROUND

Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis.

MATERIALS AND METHODS

Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n = 12), 13 and 22°C (test groups, n = 12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24 h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy.

RESULTS

Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24 h (total 120 h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42 days of storage independent of temperature profiles.

CONCLUSION

Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24 h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

Preeclampsia - Aetiology, Current Diagnostics and Clinical Management, New Therapy Options and Future Perspectives

Preeclampsia is a multisystem disease for which the exact causes have not yet been sufficiently clarified. However, in the past few years it has become clear that a placental imbalance between angiogenic and anti-angiogenic proteins is the decisive pathogenetic factor for the occurrence of preeclampsia. With the possibility to measure these angiogenic factors (sFlt-1/PlGF ratio) in maternal blood full new diagnostic possibilities have been opened that enable the certain diagnosis or exclusion of the diseases as well as a short-term prognosis to be made. In secondary prevention the current data situation for ASA confirms a moderate but measurable utility. The management concept depends on gestational age. In the case of early clinical manifestations (< 34th week of pregnancy) the clinical management in a perinatal centre remains unchanged with foeto-maternal monitoring and induction of pulmonary maturation, symptomatic therapy under careful blood pressure lowering and determination of the optimal delivery time. A balance must be made here between foetal immaturity and maternal risks upon prolongations. The pathomechanism of anti-angiogenic overload with sFlt-1 provides a starting point for first therapeutic interventions. The present article gives an overview of current diagnostic options and presents possible future therapeutic perspectives for discussion.

Pixelwise quantification of placental perfusion visualized by 3D power Doppler sonography

PURPOSE

We present a new method for noninvasive automatic measurement of perfusion intensity (PixelFlux method) in standardized 3 D power Doppler sonography to quantify differences of perfusion intensities among different placental layers.

MATERIALS AND METHODS

Power Doppler sonographic videos of anterior and central placentas were recorded at various gestational ages (13 to 38 weeks) under defined conditions in 22 women with uncomplicated pregnancies which ended in the delivery of an appropriately grown fetus. Tissue perfusion intensity in four placental layers was calculated as the product of the Doppler amplitude and the perfused area encoded by power Doppler signals related to the area of the respective layer. Measurements are given as the percentage of maximal possible perfusion.

RESULTS

Significant differences in placental perfusion intensities in the uterine wall (6.6 %), the maternal flow within the intervillous space (2.4 %), the fetal flow within placental villi (1.6 %) and the chorionic plate (9.3 %) were demonstrated with a continuous increase in the uterine wall and the placental villi.

CONCLUSION

Placental perfusion intensity was quantified noninvasively from 3 D power Doppler signal data in an easily accomplishable manner with a new software-based measurement procedure. There are significant differences in perfusion intensities among placental layers. Placenta perfusion measurement with the PixelFlux method is feasible and can discern significant perfusion differences among different placenta layers.

Human placental transthyretin in fetal growth restriction in combination with preeclampsia and the HELLP syndrome

Fetal growth restriction is a serious, still poorly understood pregnancy-related pathology often associated with preeclampsia. Recent studies speculate on the role of human transthyretin, a carrier protein for thyroxin and retinol binding protein, in the etiology of both pregnancy pathologies. Objective was to investigate the localization and abundance of transthyretin (TTR) in placentas of pregnancies suffering from fetal growth restriction with and without preeclampsia and HELLP. This was a retrospective case control study on human paraffin-embedded placentas from pregnancies with a gestational age at delivery between the 24th and 34th week of gestation. 16 placentas were included in this study, 11 cases and 5 from normotensive pregnancies as controls. Cases were divided into three groups: four from early onset idiopathic intrauterine growth restriction (IUGR), four from early-onset severe preeclampsia (PE), and three from early-onset IUGR with preeclampsia plus HELLP syndrome. Distribution and abundance of TTR were investigated by means of immunohistochemistry. Semi quantitative analysis of TTR staining of placental sections revealed that TTR was mostly expressed in the villous trophoblast covering placental villi. Only weak staining of TTR in villous stroma could be detected. The comparison of placentas revealed that in pure IUGR and severe PE there is a much stronger TTR reactivity compared to controls and cases with IUGR + PE + HELLP. Concluding, the study showed that TTR is dysregulated in cases of IUGR and severe early onset preeclampsia. Interestingly, TTR expression is not affected in cases with HELLP syndrome that reveal the same staining intensities as age-matched controls.

PP014. Estimating fully and minimal oxidized low density lipoprotein accumulation in placental tissue in intrauterine growth restriction and healthy controls

INTRODUCTION

We recently demonstrated that maternal serum LDL- and fetal serum HDL-cholesterol concentration is significantly reduced in intrauterine growth restriction (IUGR) [1].

OBJECTIVES

We now hypothesized that increased oxidative stress in IUGR placenta leads to an accumulation of oxidized LDL (oxLDL) particles which then become trapped within the placenta subsequently leading to reduced availability of cholesterol for mother and fetus.

METHODS

Fully oxidized LDL (oxLDL) was determined via immunohistochemistry in placental paraffin sections of 18 women suffering from IUGR and 18 gestational age matched controls. Ten 'High Power Fields' were chosen randomly by the newCAST software and oxLDL expression was estimated via standardized methods by two independent and blinded observers. Minimal oxidatively modified LDL (MM-LDL) and non-modified Apolipoprotein B (ApoB) concentration was measured in full placental tissue lysates by ELISA. Values were correlated with maternal and fetal total cholesterol, LDL-, and HDL-cholesterol concentrations. Statistical examinations were carried out by Student's t-test and calculation of Pearson's correlation coefficient.

RESULTS

oxLDL was found predominantly to be in villous trophoblast and placental endothelium. OxLDL intensity tended to be increased in IUGR (Table 1). We found MM-LDL concentrations in whole placental tissue lysates to be highly correlated to placental ApoB concentration (r=0.93). Both parameters were non-significantly decreased in placenta of IUGR compared to controls (Table 1). Maternal serum LDL-C, and fetal serum LDL-C, TC, and HDL-C concentrations were significantly decreased in IUGR compared to controls (Table 2). OxLDL staining intensity was mildly negatively correlated to maternal LDL-C (r=-0.315) and much less to fetal HDL-C concentrations (r=-0.212). Placental ApoB and MM-LDL concentration were moderately positively correlated with fetal HDL-C concentrations (r=0.492 and r=0.447).

CONCLUSION

Conformational changes of the ApoB lipoprotein during the process of oxidation might lead to an accumulation of oxLDL particles in placental tissue of IUGR and reduced fetal cholesterol bioavailability as evidenced by a decrease in fetal serum cholesterol levels. However, our analysis lacks in sufficient power and further studies are underway focussing on that subject.

PP015. Differential expression of Nrf2 and VEGF in human placental beds from normal and pregnancies complicated with preeclampsia and IUGR

INTRODUCTION

Impaired trophoblast invasion into the uteroplacental arteries is accompanied with an evidence of oxidative stress in the extravillous trophoblast in preeclampsia complicated with IUGR.

OBJECTIVES

Preeclampsia is characterised by increased lipid oxidation and diminished antioxidant capacity; recently, we have shown that PE is associated with an increased expression of the nuclear factor erythroid 2-related factor 2 (Nrf2) in villous cytotrophoblast. A possible relationship between the vascular endothelial growth factor (VEGF) and Nrf2 was established in vitro and the activation of Nrf2 pathway could lead to upregulation of VEGF synthesis through the induction of Nrf2-dependent Heme oxygenase-1 (HO-1). In this study the expression of Nrf2 and VEGF was determined in the interstitial and intramural extravillous trophoblast in normal pregnancies and those complicated by preeclampsia and intra-uterine growth restriction (IUGR).

METHODS

Full-thickness uterine tissues were obtained from caesarean hysterectomies performed in 5 healthy normotensive women delivering term infants and from 5 women with severe early-onset preeclampsia and IUGR (29-34 week's gestation). The interstitial and intramural trophoblasts were studied by immunohistochemical analysis of paraffin sections stained with anti VEGF and anti Nrf2.

RESULTS

Cases suffering from preeclampsia with IUGR were characterised by reduced invasion of extravillous trophoblast into uteroplacental arteries in the endometrial and myometrial segments. In addition, these cells showed an increased expression of Nrf2 in the pathological sections. The overexpression of Nrf2 in cases with preeclampsia was associated with restricted expression of VEGF in these cells compared to controls.

CONCLUSION

Our data suggest that besides villous cytotrophoblast, also the extravillous trophoblast is a source of Nrf2-dependent genes. VEGF deficiency may cause higher oxidative stress in extravillous trophoblast in cases with preeclampsia with IUGR. The resulting reduced basal defence against oxidative stress and the higher vulnerability to oxidative damage may play a role in the limited trophoblast invasion into uteroplacental arteries in cases suffering from early onset preeclampsia and IUGR.

IFPA Meeting 2011 workshop report III: Placental immunology; epigenetic and microRNA-dependent gene regulation; comparative placentation; trophoblast differentiation; stem cells

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialised topics. At IFPA meeting 2011 there were twelve themed workshops, five of which are summarized in this report. These workshops related to various aspects of placental biology: 1) immunology; 2) epigenetics; 3) comparative placentation; 4) trophoblast differentiation; 5) stem cells.

Endothelin-1 stimulates proliferation of first-trimester trophoblasts via the A- and B-type receptor and invasion via the B-type receptor

CONTEXT

Endothelin-1 (ET-1) stimulates proliferation and invasion of first-trimester human trophoblast cells.

OBJECTIVE

To test the hypothesis that ET-1 effects are mediated by different receptor subtypes [ET receptor (ETR)-A and ETR-B].

DESIGN

The location of ETR in trophoblast cell columns (wk 6-12) was investigated by immunohistochemistry and autoradiography. Trophoblasts were isolated from first-trimester human placentas and proliferative and invasive subpopulations separated using an integrin α6 antibody. Cells were incubated for 24 h with 10 μm ET-1 and different ETR antagonists: PD142893 (unselective), BQ-610 (ETR-A), and RES-701-1 (ETR-B). After ETR down-regulation by antisense oligonucleotides, proliferation (thymidine incorporation, protein synthesis) and invasion (Matrigel invasion) were measured. ETR expression in isolated cells was analyzed by Western blotting and semiquantitative RT-PCR.

RESULTS

Both ETR are expressed in both subpopulations in the cell column with predominance of ETR-A in the proximal part and proliferative subpopulation, whereas ETR-B is present at similar levels in both subpopulations. These results were confirmed at the mRNA level. ET-1 increased proliferation (maximum 267% of control) and invasion (maximum 288% of control) of first-trimester trophoblasts. The mitogenic ET-1 effect was inhibited (P < 0.05) by 40-80% with each receptor antagonist and by 44 and 40%, respectively, by ETR-A and ETR-B antisense oligonucleotides. The invasion-promoting effect was almost completely blocked in the presence of the ETR-B antagonists.

CONCLUSION

The effect of ET-1 on cell proliferation in first-trimester trophoblasts is mediated by both ETR, whereas its effect on invasion is mediated predominantly by ETR-B. These effects are in line with the receptor subtype location.

Placental markers of folate-related metabolism in preeclampsia

The etiology and degree of clinical symptoms of preeclampsia depend on genotypic and phenotypic maternal and trophoblast factors, and elevated levels of plasma homocysteine (Hcy) are one of the pathogenetic factors of preeclampsia. To assess the impact of the folate-related metabolism, we characterized the indices of this metabolism in 40 samples from uncomplicated term placentas and 28 samples from preeclamptic pregnancies by quantifying the total content of folate, methionine (Met), Hcy and related cysteine, and glutathione (GSH) in compliance with the 677 C/T genotype of methylene tetrahydrofolate reductase (MTHFR). The prevalence ofMTHFRgenotypes was not significantly different between the two groups. The polymorphism ofMTHFRwas not unambiguously connected with the content of total placental Met, Hcy and related cysteine, and GSH either in uncomplicated or in complicated pregnancies. By contrast, the combination of the heterozygousMTHFRgenotype with folate deficiency in the samples from preeclamptic pregnancies was characterized by a statistically significant decrease in the Met content, a trend toward increased Hcy levels and a tight association between metabolically directly and indirectly related compounds, e.g. positive relation between Hcy versus cysteine and folate versus GSH and negative relation between folate versus Hcy and both Hcy and cysteine versus GSH. We demonstrated the expression of cystathionine-β-synthase (CBS) in human placenta at term by RT-PCR and western blot analysis, for the first time, and confirmed its catalytic activity and the accumulation of cysteine and CBS in placental explants cultivated in the presence of elevated Hcy concentrations. We suggest that disturbance in placental folate-related metabolism may be one of the pathogenetic factors in preeclampsia.

Placenta-bound and body fluid PP13 and its mRNA in normal pregnancy compared to preeclampsia, HELLP and preterm delivery

OBJECTIVES

To compare the distribution of placental protein 13 (PP13) in fetal and maternal blood and amnionic fluid and to correlate it with PP13 protein and mRNA in the placenta.

METHODS

Umbilical arterial serum, amnionic fluid, maternal venous serum and placental tissues were collected from normal outcome pregnancies (N = 63) (GA>37), early onset preeclampsia (PE) (N = 12, GA: 26-33), and HELLP syndrome (N = 5, GA: 27-29). Because PE and HELLP cases delivered preterm, cases of preterm delivery (PTD) (N = 6, GA: 31-36) served as additional control. PP13 was determined by ELISA, Western blot, and immunohistochemistry. PP13 mRNA was measured by PCR (RT-PCR). Continuous parameters were compared by t-test, P < 0.05 was considered significant.

RESULTS

In women with normal pregnancy outcome significantly higher PP13 levels were found in maternal serum compared to amnionic fluid and negligible amount was found in fetal serum. A similar pattern was identified in cases of PTD with concentrations similar to term control. In PE and HELLP cases PP13 levels in amnionic fluid level were more than twice compared to maternal serum (P < 0.001). Umbilical cord level was negligible in PE but high in HELLP corresponding to the much higher level of PP13 in this patient group compared to all others. In the placenta PP13 level in term controls was higher compared to PTD. In PE and HELLP (similar early delivery time as PTD) the level was significantly higher (P < 0.01) compared to PTD or term controls. PP13 mRNA levels in term control and PTD were similar while PP13 mRNA levels in PE and HELLP placentas were significantly lower compared to term controls or PTD or the two combined. Syncytiotrophoblast labeling appeared stronger in PE and HELLP compared to term controls and PTD.

CONCLUSIONS

In all cases but HELLP, PP13 in fetal blood is very low indicating that routing of PP13 to fetal blood is limited and that the fetus is unlikely to generate PP13. PP13 mRNA is lower in the third trimester at the time of disease while protein level accumulates and become higher creating an unparallel change in the level of the mRNA and the corresponding protein.

Placental and trophoblastic in vitro models to study preventive and therapeutic agents for preeclampsia

In the field of preeclampsia, enormous efforts are ongoing to identify biomarkers predicting the syndrome already in the first trimester of pregnancy. At the same time, there is the need for in vitro models to test such biomarkers prior to their use in clinical trials. In addition, in vitro models may accelerate the development and evaluation of the benefit of any putative therapeutics. Therefore, in vitro systems have been established to evaluate the release of biomarkers and measure the effect of putative therapeutics using placental villous explants as well as the choriocarcinoma cell line BeWo. For explants, a cryogenic method to freeze, transport and thaw villous explants was developed to use such tissues for a multi-site tissue culture evaluation. Here we focus on three out of many in vitro models that have been established for human placental trophoblast. (1) Choriocarcinoma cell lines such as BeWo, Jeg-3 and Jar cells (2) isolated primary trophoblast cells, and (2) villous explants from normal placentas delivered at term. Cell lines were used to assess the effect of differentiation and fusion on the expression and release of a preeclampsia marker (placental protein 13; PP13) and beta-hCG. Moreover, cell lines were used to study the effect of putative preeclampsia therapeutics such as vitamins C and E, heparin and aspirin on marker release and viability. Cryopreservation of villous explants enabled shipment to a remote laboratory and testing of parameters in different countries using explants from one and the same placenta. Recently published data make it tempting to speculate that the choriocarcinoma cell line BeWo as well as fresh and cryogenically stored placental villous explants may well serve as in vitro models to study preventive and therapeutic agents in the field of preeclampsia.

Effects of calcium, magnesium, low-dose aspirin and low-molecular-weight heparin on the release of PP13 from placental explants

BACKGROUND

Preeclampsia is one of the leading causes for maternal and fetal morbidity. Attempts to prevent preeclampsia have already been made using low-dose aspirin, low-molecular-weight heparin (LMWH), and calcium supplementation. Magnesium sulphate is used at the time of disease to prevent eclampsia. Here we investigated the effect of these agents on PP13 release from placental explants.

METHODS

Placentas harvested after C-section of term or preterm control and preeclampsia cases or first trimester terminations were used to obtain explants. Explants were incubated for 24h with/without respective agents, harvested, weighed and subjected to PP13 determination in the culture medium and the explant. LDH was used to determine viability. Dose response curves were obtained for each drug. P < 0.05 was considered significant.

RESULTS

Exposure to magnesium (0.7-7g/day) slightly decreased PP13 release from controls, and slightly increased it in preeclampsia and first trimester termination. Calcium (0. 3-6g/day) showed a tendency to decrease the release in control and preeclampsia, whereas in first trimester release was increased in a bell-shaped manner. Aspirin (0-250 mg/day) tended to decrease the release in controls but increased it in a bell-shaped manner in first trimester and preeclampsia. LMWH showed no effect from 0 to 80 mg/day in controls but tended to decrease PP13 release in preeclampsia and first trimester.

CONCLUSION

This data might point to a beneficial effect of aspirin and calcium supplementation in the first trimester of pregnancy and aspirin at the time of disease, although the interaction with the maternal system still needs to be elucidated.

Endoglandular trophoblast, an alternative route of trophoblast invasion? Analysis with novel confrontation co-culture models

BACKGROUND

Routes of trophoblast invasion seem to be clear, whereas specific invasive pathways need further elucidation. Extravillous trophoblasts (EVTs) transform spiral arteries to guarantee appropriate blood flow to the placenta in the second trimester. Embryo nutrition during the first trimester is thought to be histiotrophic, whereas proof that EVTs also invade uterine glands is lacking. We developed novel three-dimensional confrontation co-culture models to elucidate invasion of EVTs into uterine glands.

METHODS

First trimester decidua parietalis and placental villous explants were directly confronted and co-cultured for 72 h, or confronted indirectly after 72 h pre-culture for re-epithelialization of decidua pieces. Cryosections were stained by immunohistochemistry or immunofluorescent/immunohistochemical double labelling and compared with first trimester placentation sites in situ.

RESULTS

EVTs deeply invaded decidual tissues in direct confrontation assays and were found between the decidual epithelial cells and epithelial basement membrane. EVTs were also detected in the decidual stroma in direct proximity to glands, sometimes even replacing glandular epithelial cells. Similar observations were made in sections from the first trimester decidua/placental bed. In the invaded parts of sections of decidua basalis, 55% +/- 7% (mean +/- SEM; n = 10, range 6-11 weeks) of glandular cross sections were associated with or infiltrated by EVTs.

CONCLUSIONS

Using novel confrontation co-culture assays, a potential new route of EVT invasion was detected. EVTs appear to break through the basement membrane of uterine glands to open their lumen towards the intervillous space. These data support the hypothesis of histiotrophic nutrition of the embryo prior to onset of maternal blood flow within the placenta.

Differential expression of VE-cadherin and VEGFR2 in placental syncytiotrophoblast during preeclampsia - New perspectives to explain the pathophysiology

The pathophysiology of preeclampsia includes an unbalanced syncytiotrophoblast renewal from the underlying cytotrophoblast and increased necrotic/aponecrotic shedding of syncytiotrophoblast particles into the maternal circulation. These non-apoptotic syncytiotrophoblast fragments cause the maternal endothelial dysfunction underlying the syndrome of preeclampsia. In order to understand the pathophysiological changes at the fetomaternal interface in preeclampsia we studied the expression of VE-cadherin and vascular endothelial growth factor receptor-2 (VEGFR2) in preeclampsia. We show that VE-cadherin is expressed in the syncytiotrophoblast and is upregulated in fusing BeWo cells, while inhibition of VE-cadherin expression by siRNA does not block BeWo cell fusion. Our immunohistochemistry data show lower VE-cadherin expression in early onset preeclampsia compared to early controls. In late onset preeclampsia VE-cadherin was significantly more expressed compared to late controls. Concurrently VE-cadherin expression decreased significantly in control pregnancies towards term, but not in pregnancies complicated by preeclampsia. VEGFR2 expression was significantly reduced in all cases of preeclampsia compared to control placentas. Because of their close interaction in barrier function regulation we speculate that sustained expression of VE-cadherin in late onset preeclampsia could counteract VEGFR2 deficiency by enhancing survival pathway stimulation in the syncytiotrophoblast, thus preventing further decompensation of unbalanced villous trophoblast turnover.

The paradox of caspase 8 in human villous trophoblast fusion

Differentiation and subsequent fusion of villous cytotrophoblasts with the overlying syncytiotrophoblast is an essential process for growth and maintenance of the villous trophoblast layer in the human placenta. The understanding of intrinsic mechanisms behind this process is in its infancy, while the list of suggested factors, involved in intercellular fusion of trophoblasts, rapidly increased in the recent past and promises progress on this issue. The early stages of the apoptosis cascade, in particular caspase 8, was suggested to trigger differentiation of cytotrophoblasts, priming them for upcoming fusion. This may sound paradoxical, especially for those who still associate caspase activity with apoptosis only. Here, we summarize data on caspase 8 in the villous trophoblast layer, with a specific focus on localization of pro- and active forms, the sites of its activation and deactivation, and its role and regulation during fusion. Moreover, we revisit the knowledge on fusogens in the villous trophoblast, compare in vitro models for trophoblast fusion and discuss methods to quantify fusion.

IFPA Award in Placentology Lecture: Biology of the placental syncytiotrophoblast--myths and facts

About 15 years ago apoptosis was attributed a role in the development of the human placenta. Since then an increasing number of publications has shown that programmed cell death plays an essential role in placental growth and differentiation, especially in the villous trophoblast. During the last ten years a concept was established linking the progress of apoptosis to differentiation of cytotrophoblasts and syncytiotrophoblast. Thus, development and maintenance of the syncytiotrophoblast depends on the precise orchestration of different processes and stages of the apoptosis cascade. This review focuses on the maintenance and growth of the syncytiotrophoblast as well as the deportation of trophoblast material into the maternal circulation. Nuclear morphology is related to transcriptional activity, RNA protection and storage strategies are discussed and the differences between syncytial expression rates of RNA and protein are highlighted. Moreover, deportation of trophoblast fragments is related to the relevant morphological structures (syncytial knots) and to their effects on the maternal system. Finally, different modes of release of trophoblast fragments such as apoptotic, aponecrotic and necrotic are discussed as being responsible for the maternal inflammatory response during pre-eclampsia.

Caspases rather than calpains mediate remodelling of the fodrin skeleton during human placental trophoblast fusion

Fusion of cytotrophoblasts with the overlying syncytiotrophoblast is an integral step in differentiation of the human placental villous trophoblast. Multiple factors, such as growth factors, hormones, cytokines, protein kinases, transcription factors and structural membrane proteins, were described to modulate trophoblast fusion. However, the knowledge on remodelling of the membrane-associated cytoskeleton during trophoblast fusion is very limited. This study describes the link between remodelling of spectrin-like alpha-fodrin and intercellular trophoblast fusion. Experiments with primary trophoblasts isolated from term placentas and the choriocarcinoma cell line BeWo revealed a biphasic strategy of the cells to achieve reorganization of alpha-fodrin. Syncytialization of trophoblasts was accompanied by down-regulation of alpha-fodrin mRNA, whereas the full-length alpha-fodrin protein was cleaved into 120 and 150 kDa fragments. Application of calpeptin and calpain inhibitor III did not affect alpha-fodrin fragmentation in primary term trophoblasts and forskolin-treated BeWo cells, but decreased secretion of beta human chorionic gonadotropin. In contrast, inhibitors of caspases 3, 8 and 9 attenuated generation of the 120 kDa fragment and a general caspase inhibitor completely blocked fragmentation, suggesting an exclusive function of caspases in alpha-fodrin remodelling. Immunofluorescence double staining of human placenta revealed co-localization of active caspase 8 with alpha-fodrin positive vesicles in fusing villous cytotrophoblasts. These results suggest that caspase-dependent fragmentation of alpha-fodrin may be important for reorganization of the sub-membranous cytoskeleton during trophoblast fusion.

[Effect of homocysteine on the structure and functions of human placenta trophoblasts]

Elevated level of homocysteine in blood serum of pregnant women is the risk factor for placental malfunction and fetal abnormalities. Our study has shown the activation of apoptosis, inhibition of proliferation, destruction of placental trophoblast and activation of the transsulfuration pathway under elevated homocysteine level in the incubation medium in the range of 20-80 microM. The activation of the transsulfuration pathway indicates that placenta may to some extent withstand elevated homocysteine level.