Latest advances in understanding preeclampsia

Fusiogenic endogenous-retroviral syncytin-1 exerts anti-apoptotic functions in staurosporine-challenged CHO cells

Fusiogenic glycoprotein syncytin-1, expressed in human placenta, is a promising candidate for acquiring a basic knowledge of placental syncytialization. However, its cellular mode of action is unidentified. We investigated whether syncytin-1 may exert influence on apoptotic processes. Therefore, we incubated CHO cells after stable transfection with syncytin-1 (CHO-52) in the presence or absence of staurosporine (STS), a kinase inhibitor well characterized to induce apoptosis. When testing the phenotype of CHO-52 cells, we could demonstrate that the induction of apoptosis by STS was delayed over a period of up to 24 h. Furthermore, the cell death rate was decreased by approx 75% following transfection of syncytin-1 in CHO-52 compared to mock-treated cells. In detail, after 18h of incubation with 500 nM STS, 64 +/- 2% of CHO-52 cells were viable compared to 16 +/- 1% of CHO-mocks, after 24 h 43 +/- 3% vs 5 +/- 2%, respectively. CHO-52 cells exhibited a lower expression of active caspase 3 and anti-apoptotic Bcl-2 was found to be increased in CHO-52 cells at baseline and following STS treatment. Our study provides first evidence that syncytin-1 serves anti-apoptotic function under certain conditions. A lessened activation of caspase 3 and an increased expression of Bcl-2 are possible mechanisms.

Elevated serum levels of interleukin-15 and interleukin-16 in preeclampsia

A generalized inflammatory response has been considered to be the main pathology and has an important role in the pathogenesis of preeclampsia. The immune aberrations per se and immunomodulatory milieu present in serum need to be elucidated. The purpose of the current investigation was to characterize changes in serum levels of interleukin (IL)-15 and IL-16 in preeclampsia. Thirty-seven women with preeclampsia were recruited and 36 age- and gestational age-matched women with normal pregnancy served as control. Levels of IL-15 and IL-16 were detected with immune assays in all serum samples. We found that serum levels of IL-15 and IL-16 were significantly higher in preeclampsia than in normal pregnancy (p<0.001 for both). There were significant differences in serum IL-15 and IL-16 between mild and severe preeclampsia (p<0.01 for both). Our data corroborate the hypothesis of an increased inflammatory response in preeclampsia, as illustrated by the elevated serum levels of IL-15 and IL-16, suggesting their possible role in the pathogenesis of preeclampsia. These associations may offer insight into the pathophysiology of preeclampsia.

Arginase activity mediates reversible T cell hyporesponsiveness in human pregnancy

Complex regulation of T cell functions during pregnancy is required to ensure materno-fetal tolerance. Here we reveal a novel pathway for the temporary suppression of maternal T cell responses in uncomplicated human pregnancies. Our results show that arginase activity is significantly increased in the peripheral blood of pregnant women and remarkably high arginase activities are expressed in term placentae. High enzymatic activity results in high turnover of its substrate L-arginine and concomitant reduction of this amino acid in the microenvironment. Amino acid deprivation is emerging as a regulatory pathway of lymphocyte responses and we assessed the consequences of this enhanced arginase activity on T cell responses. Arginase-mediated L-arginine depletion induces down-regulation of CD3 zeta, the main signalling chain of the TCR, and functional T cell hyporesponsiveness. Importantly, this arginase-mediated T cell suppression was reversible, as inhibition of arginase activity or addition of exogenous L-arginine restored CD3 zeta chain expression and T cell proliferation. Thus, L-arginine metabolism constitutes a novel physiological mechanism contributing to the temporary suppression of the maternal immune response during human pregnancy.

Angiogenic growth factor levels in maternal and fetal blood: correlation with Doppler ultrasound parameters in pregnancies complicated by pre-eclampsia and intrauterine growth restriction

OBJECTIVES

To correlate levels of angiogenic growth factors with Doppler ultrasound parameters in pregnancies complicated by pre-eclampsia and intrauterine growth restriction (IUGR).

METHODS

In 16 women with pre-eclampsia and 15 women with isolated IUGR, pulsatility indices (PI) in the umbilical and uterine arteries were measured by Doppler ultrasonography. At delivery, maternal and fetal blood (umbilical vein and artery separately) was sampled and angiogenic growth factors measured by means of enzyme linked immunosorbent assay (ELISA).

RESULTS

Umbilical artery PI was significantly higher in women with IUGR than in those with pre-eclampsia, whereas uterine artery PI was not statistically significantly different. Maternal soluble fms-like tyrosine kinase-1 (sFlt-1) levels were higher in women with pre-eclampsia than in those with IUGR (P < 0.0001). Umbilical vein basic fibroblast growth factor (bFGF) levels were lower in women with pre-eclampsia than in those with IUGR (P < 0.05). Placental growth factor (PlGF) levels in the umbilical vein were below the detection limit in nearly all samples of IUGR fetuses and lower than in those with pre-eclampsia (P < 0.001). Maternal PlGF levels were inversely correlated with PI values of both vessels. In the umbilical vein sFlt-1 was positively and soluble kinase insert domain receptor (sKDR) negatively correlated with umbilical artery PI. No correlation could be found in the serum of the umbilical artery for all growth factors and for vascular endothelial growth factor (VEGF) in all compartments.

CONCLUSIONS

The correlations between maternal and fetal angiogenic growth factor serum levels and Doppler ultrasound indices of uterine and umbilical arteries in pre-eclampsia and IUGR reflect the severity of the disorders especially for the fetus. A combination of both measurements may be useful in future screening for early prediction of pregnancy complications. Published by John Wiley & Sons, Ltd.

Identification of patients at risk for early onset and/or severe preeclampsia with the use of uterine artery Doppler velocimetry and placental growth factor

OBJECTIVE

Preeclampsia has been proposed to be an antiangiogenic state that may be detected by the determination of the concentrations of the soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and placental growth factor (PlGF) in maternal blood even before the clinical development of the disease. The purpose of this study was to determine the role of the combined use of uterine artery Doppler velocimetry (UADV) and maternal plasma PlGF and sVEGFR-1 concentrations in the second trimester for the identification of patients at risk for severe and/or early onset preeclampsia.

STUDY DESIGN

A prospective cohort study was designed to examine the relationship between abnormal UADV and plasma concentrations of PlGF and sVEGFR-1 in 3348 pregnant women. Plasma samples were obtained between 22 and 26 weeks of gestation at the time of ultrasound examination. Abnormal UADV was defined as the presence of bilateral uterine artery notches and/or a mean pulsatility index above the 95th percentile for the gestational age. Maternal plasma PlGF and sVEGFR-1 concentrations were determined with the use of sensitive and specific immunoassays. The primary outcome was the development of early onset preeclampsia (< or = 34 weeks of gestation) and/or severe preeclampsia. Secondary outcomes included preeclampsia, the delivery of a small for gestational age (SGA) neonate without preeclampsia, spontaneous preterm birth at < or = 32 and < or = 35 weeks of gestation, and a composite of severe neonatal morbidity. Contingency tables, chi-square test, receiver operating characteristic curve, and multivariate logistic regression were used for statistical analyses. A probability value of < .05 was considered significant.

RESULTS

(1) The prevalence of preeclampsia, severe preeclampsia, and early onset preeclampsia were 3.4% (113/3296), 1.0% (33/3296), and 0.8% (25/3208), respectively. UADV was performed in 95.4% (3146/3296) and maternal plasma PlGF concentrations were determined in 93.5% (3081/3296) of the study population. (2) Abnormal UADV and a maternal plasma PlGF of < 280 pg/mL were independent risk factors for the occurrence of preeclampsia, severe preeclampsia, early onset preeclampsia, and SGA without preeclampsia. (3) Among patients with abnormal UADV, maternal plasma PlGF concentration contributed significantly in the identification of patients destined to develop early onset preeclampsia (area under the curve, 0.80; P < .001) and severe preeclampsia (area under the curve, 0.77; P < .001). (4) In contrast, maternal plasma sVEGFR-1 concentration was of limited use in the prediction of early onset and/or severe preeclampsia. (5) The combination of abnormal UADV and maternal plasma PlGF of < 280 pg/mL was associated with an odds ratio (OR) of 43.8 (95% CI, 18.48-103.89) for the development of early onset preeclampsia, an OR of 37.4 (95% CI, 17.64-79.07) for the development of severe preeclampsia, an OR of 8.6 (95% CI, 5.35-13.74) for the development of preeclampsia, and an OR of 2.7 (95% CI, 1.73-4.26) for the delivery of a SGA neonate in the absence of preeclampsia.

CONCLUSION

The combination of abnormal UADV and maternal plasma PlGF concentration of < 280 pg/mL in the second trimester is associated with a high risk for preeclampsia and early onset and/or severe preeclampsia in a low-risk population. Among those with abnormal UADV, a maternal plasma concentration of PlGF of < 280 pg/mL identifies most patients who will experience early onset and/or severe preeclampsia.

Negative regulation of soluble Flt-1 and soluble endoglin release by heme oxygenase-1

BACKGROUND

Preeclampsia is characterized clinically by hypertension and proteinuria. Soluble Flt-1 (sFlt-1; also known as soluble vascular endothelial growth factor receptor-1 [VEGFR-1]) and soluble endoglin (sEng) are elevated in preeclampsia, and their administration to pregnant rats elicits preeclampsia-like symptoms. Heme oxygenase-1 (HO-1) and its metabolite carbon monoxide (CO) exert protective effects against oxidative stimuli. Thus, we hypothesized that HO-1 upregulation may offer protection against preeclampsia by inhibiting sFlt-1 and sEng release.

METHODS AND RESULTS

Preeclamptic villous explants secreted high levels of sFlt-1 and sEng. Adenoviral overexpression of HO-1 in endothelial cells inhibited VEGF-mediated sFlt-1 release and interferon-gamma- and tumor necrosis factor-alpha-induced sEng release, whereas HO-1 inhibition potentiated sFlt-1 and sEng production from endothelial cells and placental villous explants. Consistent with these findings, mice lacking HO-1 produced higher levels of sFlt-1 and sEng compared with wild-type mice. Using selective ligands (VEGF-E and placental growth factor) and a receptor-specific inhibitor (SU-1498), we demonstrated that VEGF-induced sFlt-1 release was VEGFR-2 dependent. Furthermore, CO-releasing molecule-2 (CORM-2) or CO decreased sFlt-1 release and inhibited VEGFR-2 phosphorylation. Treatment of endothelial cells with statins upregulated HO-1 and inhibited the release of sFlt-1, whereas vitamins C and E had no effect.

CONCLUSIONS

The present study demonstrates that the HO-1/CO pathway inhibits sFlt-1 and sEng release, providing compelling evidence for a protective role of HO-1 in pregnancy, and identifies HO-1 as a novel target for the treatment of preeclampsia.

Malaria in pregnancy: pathogenesis and immunity

Understanding of the biological basis for susceptibility to malaria in pregnancy was recently advanced by the discovery that erythrocytes infected with Plasmodium falciparum accumulate in the placenta through adhesion to molecules such as chondroitin sulphate A. Antibody recognition of placental infected erythrocytes is dependent on sex and gravidity, and could protect from malaria complications. Moreover, a conserved parasite gene-var2csa-has been associated with placental malaria, suggesting that its product might be an appropriate vaccine candidate. By contrast, our understanding of placental immunopathology and how this contributes to anaemia and low birthweight remains restricted, although inflammatory cytokines produced by T cells, macrophages, and other cells are clearly important. Studies that unravel the role of host response to malaria in pathology and protection in the placenta, and that dissect the relation between timing of infection and outcome, could allow improved targeting of preventive treatments and development of a vaccine for use in pregnant women.

Inflammatory Changes in Preeclampsia: Current Understanding of the Maternal Innate and Adaptive Immune Response

Preeclampsia is characterized by generalized endothelial dysfunction as a result of an inappropriate maternal immune response against the fetus. It has been postulated that the adaptive immune system plays a key role in the etiology of preeclampsia by generating a pro-inflammatory Th1 type immune reaction. In this review, recent studies on Th1 and Th2 type cytokine mapping in preeclampsia are reviewed, as well as on the sources of pro-inflammatory cytokines and the role of regulatory cytokines and chemokines. In addition, we discuss the possible role of Toll-like receptors of the innate immune system in the pathophysiology of preeclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to summarize the newer concepts related to the pathogenesis of preeclampsia and explain the role of the maternal immune system and the role of pro-inflammatory and regulatory cytokines and chemokines in the pathophysiology of the disease.

Pre-eclampsia but not pregnancy-induced hypertension is a risk factor for diabetic nephropathy in type 1 diabetic women

AIMS/HYPOTHESIS

Our aim was to study whether pre-eclampsia and pregnancy-induced hypertension are predictors of diabetic nephropathy in type 1 diabetic women.

MATERIALS AND METHODS

A total of 203 type 1 diabetic women, who were pregnant between 1988 and 1996 and followed at the Department of Obstetrics and Gynaecology in Helsinki, were re-assessed after an average of 11 years within the nationwide, multi-centre Finnish Diabetic Nephropathy Study. Diabetic nephropathy was defined as microalbuminuria, macroalbuminuria or end-stage renal disease.

RESULTS

Patients with prior pre-eclampsia had diabetic nephropathy more often than patients with a normotensive pregnancy (diabetic nephropathy vs normal albumin excretion rate: 41.9% vs 8.9%; p<0.001), whereas patients with a history of pregnancy-induced hypertension did not (10.3% vs 8.9%; p=0.81). CHD was more prevalent in patients with a history of pre-eclampsia than in patients with a normotensive pregnancy (12.2% vs. 2.2%; p=0.03). Pre-eclampsia (odds ratio [OR] 7.7, 95% CI 1.6-36.1; p=0.01) and HbA(1c) (OR 2.0, 95% CI 1.1-3.8; p<0.05) were associated with incident diabetic nephropathy even when adjusted for follow-up time, BMI, smoking, diabetes duration and age.

CONCLUSIONS/INTERPRETATION

These data suggest that a history of pre-eclamptic pregnancy but not pregnancy-induced hypertension is associated with an elevated risk of diabetic nephropathy.

Cell-Free mRNA Concentrations of Plasminogen Activator Inhibitor-1 and Tissue-Type Plasminogen Activator Are Increased in the Plasma of Pregnant Women with Preeclampsia

Background: Detection of placental mRNA in maternal plasma has been reported in high-risk pregnancies. We attempted to investigate the concentrations of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) mRNA in maternal plasma in preeclampsia.

Methods: Peripheral blood samples were obtained from healthy pregnant women before and after delivery and also from women with or without preeclampsia. Plasma was isolated from these samples, and RNA was extracted. Plasma PAI-1 and tPA mRNA concentrations were then measured by use of reverse transcription PCR assays. The concentrations were converted into multiples of the median (MoM) of the controls adjusted for gestational age. Data were stratified and analyzed according to the clinical severity of preeclampsia and quantitative distribution of blood pressure and proteinuria.

Results: The median (minimum–maximum) PAI-1 mRNA MoM values for women with preeclampsia and controls were 2.48 (0.82–8.53) and 1.00 (0.41–2.33), respectively, whereas the median (minimum–maximum) tPA mRNA MoM values were 3.33 (1.01–10.58) and 1.00 (0.95–1.20), respectively. The concentrations of both PAI-1 and tPA mRNA were significantly increased in cases of preeclampsia, compared with controls (P &lt;0.0001). The MoM values of both mRNA species were directly correlated with the severity of preeclampsia and were greatest among a subgroup of hemolysis, increased liver enzymes, and low platelets pregnancies.

Conclusion: Maternal plasma PAI-1 and tPA mRNAs are significantly increased in patients with preeclampsia and are positively correlated with the severity of preeclampsia.

Mannose-binding lectin (MBL) codon 54 gene polymorphism protects against development of pre-eclampsia, HELLP syndrome and pre-eclampsia-associated intrauterine growth restriction

Insufficient invasion of the spiral arteries by trophoblast cells is associated with the etiology of pre-eclampsia, the syndrome of hemolysis, elevated liver enzymes and low platelet counts (HELLP) and pre-eclampsia-associated intrauterine growth restriction (IUGR). Mannose-binding lectin (MBL) is a component of the innate immune system. MBL-mediated activation of the complement cascade is an important event in the destruction of invading trophoblasts. The gene coding for MBL is polymorphic, and variant alleles result in greatly reduced circulating MBL levels. The aim of this study was to test the association between an MBL polymorphism and pre-eclampsia, HELLP syndrome and IUGR. DNA was extracted from buccal swabs of 51 women with pre-eclampsia, 81 women with HELLP syndrome and 184 healthy pregnant controls. Aliquots were tested for a single nucleotide MBL gene polymorphism at codon 54 by PCR and endonuclease digestion. Homozygosity for the wild-type allele was more frequent in patients with pre-eclampsia (P = 0.04) and HELLP syndrome (P = 0.02) when compared with controls. The presence of the variant allele was more prevalent among controls than in women with pre-eclampsia (P = 0.02) or HELLP syndrome (P = 0.028). Twenty-two (55%) patients with pre-eclampsia and 43 (53%) women with HELLP syndrome delivered an IUGR neonate. MBL-54 heterozygosity was more frequent in controls (27.2%) than in pre-eclamptic women (4.5%, P = 0.025) and those with HELLP syndrome (11.7%, P = 0.05) who delivered an IUGR neonate. Genotype frequencies of neonates born to mothers in all study groups were similar. Carriage of the MBL codon 54 polymorphism protects against pre-eclampsia, HELLP syndrome and IUGR and implies that an MBL-mediated event might be involved in the pathogenesis of these disorders.

Genome-wide expression profiling of placentas in the p57Kip2 model of pre-eclampsia

Pre-eclampsia affects 6-10% of pregnancies and is one of the primary causes of premature birth. It is widely accepted that inappropriate placental development, combined with environmental factors, plays a major role in disease pathogenesis. The p57(Kip2) mouse is the only mouse model of pre-eclampsia that recapitulates the full spectrum of symptoms of the human disease, including placental abnormalities, hypertension, proteinuria and premature labour. In addition, pregnant females expressing wild-type levels of p57(Kip2) develop pre-eclampsia when carrying fetuses that lack p57(Kip2) expression. This demonstrates that either the fetus or the placenta causes the disease. Here, taking advantage of the unique genetics of the p57(Kip2) mouse, we have used full genome expression profiling to define the placental aspect of the p57(Kip2) phenotype at a molecular level and to conduct an unbiased search for factors involved in pre-eclampsia pathogenesis. During this analysis, we found that although mutant embryos demonstrate altered placental architecture and have histological changes indicative of reduced utero-placental blood flow, the p57(Kip2) pregnant females do not demonstrate hypertension or renal pathology. This suggests a model in which placental abnormalities cause pre-eclampsia only given other environmental variables. On the basis of this model, we expect that misregulation of molecular factors, while not able to cause a full spectrum of disease symptoms in this context, still occurs in these p57(Kip2) mutant mice. Our studies suggest a role for environmental factors in the p57(Kip2) pre-eclampsia phenotype and have identified several candidates for pre-eclampsia predisposition in this model, including known regulators of blood pressure, inflammation and apoptosis.

Control of human trophoblast function

The trophoblast, i.e. the peripheral part of the human conceptus, exerts a crucial role in implantation and placentation. Both processes properly occur as a consequence of an intimate dialogue between fetal and maternal tissues, fulfilled by membrane ligands and receptors, as well as by hormone and local factor release. During blastocyst implantation, generation of distinct trophoblast cell types begins, namely the villous and the extravillous trophoblast, the former of which is devoted to fetal-maternal exchanges and the latter binds the placental body to the uterine wall. Physiological placentation is characterized by the invasion of the uterine spiral arteries by extravillous trophoblast cells arising from anchoring villi. Due to this invasion, the arterial structure is replaced by amorphous fibrinoid material and endovascular trophoblastic cells. This transformation establishes a low-resistance, high-capacity perfusion system from the radial arteries to the intervillous space, in which the villous tree is embedded. The physiology of pregnancy depends upon the orderly progress of structural and functional changes of villous and extravillous trophoblast, whereas a derangement of such processes can lead to different types of complications of varying degrees of gravity, including possible pregnancy loss and maternal life-threatening diseases. In this review we describe the mechanisms which regulate trophoblast differentiation, proliferation, migration and invasiveness, and the alterations in these mechanisms which lead to pathological conditions. Furthermore, based on the growing evidence that proper inflammatory changes and oxidative balance are needed for successful gestation, we explain the mechanisms by which agents able to influence such processes may be useful in the prevention and treatment of pregnancy disorders.

Chronic hypoxia in vivo reduces placental oxidative stress

Decreased placental oxygenation and increased oxidative stress are implicated in the development of preeclampsia. Oxidative stress arises from imbalance between pro-versus anti-oxidants and can lead to biological oxidation and apoptosis. Because pregnant women living at high altitude (3100 m, HA) have lowered arterial PO2 and an increased incidence of preeclampsia, we hypothesized that HA placentas would have decreased anti-oxidant enzyme activity, increased oxidative stress (lipid peroxidation, protein oxidation and nitration) and greater trophoblast apoptosis than low-altitude (LA) placentas. We measured enzymatic activities, lipid and protein oxidation and co-factor concentrations by spectrophotometric techniques and ELISA in 12 LA and 18 HA placentas. Immunohistochemistry (IHC) was used to evaluate nitrated proteins and specific markers of apoptosis (activated caspase 3 and M30). Superoxide dismutase activity was marginally lower (p=0.05), while glutathione peroxidase activity (p<0.05), thioredoxin concentrations (p<0.005) and thioredoxin reductase activity p<0.01 were all reduced in HA placentas. Decreased anti-oxidant activity was not associated with increased oxidative stress: lipid peroxide content and protein carbonyl formation were lower at HA (p<0.01). We found greater nitrotyrosine residues in the syncytiotrophoblast at 3100 m (p<0.05), but apoptosis did not differ between altitudes. Our data suggest that hypoxia does not increase placental oxidative stress in vivo. Nitrative stress may be a consequence of hypoxia but does not appear to contribute to increased apoptosis. Lowered placental concentrations of anti-oxidants may contribute to the susceptibility of women living at HA to the development of preeclampsia, but are unlikely to be etiological.

Recent advances in the prevention and treatment of congenital cytomegalovirus infections

Continued but slow progress has led to recent advances in our understanding that congenital cytomegalovirus (CMV) infection has occurred. We understand that the most severe congenital disease occurs following a primary maternal infection during pregnancy. We now have the ability to accurately diagnosis a primary maternal infection using serologic studies of single serum sample. For pregnant women with young children, we know that child-to-mother CMV transmission can probably be prevented by hygienic intervention, and that for pregnant women who have acquired a primary CMV infection, mother-to-fetal transmission is probably preventable using CMV hyperimmune globulin. Although additional studies are needed, treatment of congenitally infected fetuses or newborns should be possible using either CMV hyperimmune globulin or antiviral agents such as ganciclovir or its derivates. Finally, recent evidence indicates that CMV replicates in the placenta, impairs development, and causes inflammation and dysfunction. This plus the reversibility of many manifestations of congenital infection in the fetus and newborn indicate that congenital CMV disease is in part a syndrome of placental insufficiency.

Paradoxical Discrepancy Between the Serum Level and the Placental Intensity of PP5/TFPI-2 in Preeclampsia and/or Intrauterine Growth Restriction: Possible Interaction and Correlation with Glypican-3 Hold the Key

There have been controversies whether maternal serum placental protein 5 (PP5)/tissue factor pathway inhibitor (TFPI)-2 is increased in the patients with preeclampsia and/or intrauterine growth restriction (IUGR). Here, we have estimated the serum PP5/TFPI-2 in these patients by a sandwich enzyme-linked immunosorbent assay with a newly developed monoclonal antibody, coupled with placental immunohistochemical studies of their placentae with semiquantitative scoring. Serum PP5/TFPI-2 level was significantly elevated only in the patients with preeclampsia alone (p=0.033), while PP5/TFPI-2 was detected significantly less intensely in the placentae of the same patients (p=0.035) in immunohistochemistry, as compared to Controls. A proteoglycan present on the placental villous surface, glypican-3, showed the same pattern of staining as PP5/TFPI-2, and there was a positive correlation (C.I.=0.506, p=0.004) between the immunohistochemical scores for these. Further experiments using HepG2 cells transfected with PP5/TFPI-2 suggested that glypican-3 could anchor PP5/TFPI-2 on the placental villi. A possibility that a decrease in glypican-3 in the placenta increases the outflow of PP5/TFPI-2, which in turn increases its serum level, was proposed. Preeclampsia and IUGR, often regarded to have the same pathological basis in common, showed distinct distributions of PP5/TFPI-2, which could be a clue to elucidate the pathogenesis of preeclampsia and IUGR.

Calcitonin gene-related peptide (CALCA) is a proangiogenic growth factor in the human placental development

Recent studies have shown that homozygous knockout of gene for calcitonin gene-related peptide (CALCA) receptor component, calcitonin receptor-like receptor (CALCRL), led to extreme hydrops fetalis and embryonic death, underlining the critical role of CALCA in embryonic development and fetal growth. The present study was designed to determine the cellular localization of CALCA and its receptor components, CALCRL and receptor activity modifying protein 1 (RAMP1), at the human implantation site during early pregnancy; to assess whether CALCA regulates in vitro angiogenesis of human endothelial cells; and to examine whether CALCA can improve angiogenic imbalance in preeclamptic placental explants. Our studies demonstrated that both protein and mRNA for CALCA were expressed by the villous and extravillous trophoblasts and decidual cells in the first-trimester villous tissues. CALCA receptor components, CALCRL and RAMP1, were expressed by both villous and extravillous trophoblast cells, as well as vascular endothelial cells. CALCA induced both endothelial proliferation and migration in a dose- and time-dependent manner, and it promoted capillarylike tube formation of human umbilical vein endothelial cells (HUVECs) on Matrigel. CALCA-induced angiogenesis of human endothelial cells was completely blocked by CALCA antagonist CALCA(8-37). Further, conditioned medium from preeclamptic placental explants significantly inhibited HUVEC capillarylike tube formation compared with gestational age-matched controls, and conditioned medium from preeclamptic placental explants incubated with CALCA significantly improved capillarylike tube formation. We conclude that CALCA induces in vitro angiogenesis by stimulating endothelial cell proliferation, migration, and capillarylike tube formation; thus, CALCA at the human implantation site may constitute a potential autocrine or paracrine mechanism that could modify placental angiogenesis and neovascularization.

Dysregulation of the circulating and tissue-based renin-angiotensin system in preeclampsia

The renin-angiotensin system (RAS) participates in preeclampsia; however, the relative contributions from the circulating RAS and the tissue-based, uteroplacental RAS are unknown. We hypothesized that the tissue-based uteroplacental RAS is dysregulated in preeclampsia. We performed microarray and gene expression studies and confirmed the findings on the protein level by immunohistochemistry in ureteroplacental units from 10 preeclamptic women and 10 women with uneventful pregnancies. All of the women were delivered by cesarean section. We also analyzed plasma renin activity and circulating agonistic angiotensin II type 1 (AT1) receptor autoantibodies. In preeclampsia, we found that the angiotensin II AT1 receptor gene was 5-fold upregulated in decidua (maternal origin). We also found AT1 autoantibodies in preeclamptic women and in their offspring by neonatal cardiomyocyte bioassay compared with women with normal pregnancies and their infants (mother: 17.5+/-2.2 versus 0.05+/-0.4; fetus: 14.5+/-1.8 versus 0.5+/-0.5 Deltabpm). Gene expressions for renin (35.0-fold), angiotensin-converting enzyme (2.9-fold), and angiotensinogen (8.9-fold) were higher in decidua than placenta (fetal origin) in both control and preeclamptic women, whereas the AT1 receptor was expressed 10-fold higher in placenta than in decidua in both groups. Our findings elucidate the ureteroplacental unit RAS in preeclamptic and normal pregnancies. We found that, in preeclampsia, the AT1 receptor expression is particularly high in decidua, combined with pregnancy-specific tissue RAS involving decidual angiotensin II production and AT1 autoantibodies. We also showed that AT1 autoantibodies cross the ureteroplacental barrier. These components could participate in the pathophysiology of preeclampsia.

Lower rate of preeclampsia after antioxidant supplementation in pregnant women with low antioxidant status

OBJECTIVE

To investigate maternal and neonatal outcomes after antioxidant supplementation relatively early in pregnancy (8 to 12 weeks) for pregnant women with low antioxidant status.

METHODS

A randomized, double-blind, placebo-controlled trial of daily antioxidant supplementation was performed on pregnant women screening positive for low antioxidant status at 8 to 12 weeks of gestation. Low antioxidant status was defined as a superoxidedismutase (SOD) level below 1102 U/g Hb or 164 U/mL. The supplementation group received the following antioxidants daily: vitamins A (1000 IU), B6 (2.2 mg), B12 (2.2 microg), C (200 mg), and E (400 IU), folic acid (400 microg), N-acetylcysteine (200 mg), Cu (2 mg), Zn (15 mg), Mn (0.5 mg), Fe (30 mg), calcium (800 mg), and selenium (100 microg). The control group received Fe (30 mg) and folic acid (400 microg). Maternal (preeclampsia, abortion, and hypertension) and perinatal outcomes were assessed.

RESULTS

In the supplementation group (29 subjects), we observed 2 cases of preeclampsia (6.8%, 1 mild and 1 severe), 1 of IUGR (birth weight 2300 g at 38 weeks), and 1 preterm delivery. In the control group (31 subjects), there were 8 abortions, 9 cases of preeclampsia (29%, 6 mild and 3 severe) with perinatal outcome: 3 preterm delivery cases and 1 IUGR (birth weight 2030 g at 39 weeks). Preeclampsia was significantly less frequent in the supplementation group when compared to the control group (2 vs. 9 cases, p = 0.043, OR = 0.18 [95% CI: 0.03, 0.92]). Finally we focused on the prediction of preeclampsia at 8 to 12 weeks. Combined sensitivity of markers of antioxidant status (SOD slutathione peroxidase, [GPx], and total anti-oxidant status [TAS]) was 33% (false-positive rate of 4.5%).

CONCLUSION

Antioxidant supplementation was associated with better maternal and perinatal outcome in pregnant women with low antioxidant status than control supplementation with iron and folate alone. In a selected population already screened positive for low SOD, preeclampsia can be detected in 33% of asymptomatic cases in the first trimester using SOD, GPx, and TAS. It seems feasible that panels of both biochemical and molecular markers may be clinically useful in the prediction of this disease.

KIR and disease: a model system or system of models?

The discovery of an unexpected level of diversity among the killer cell immunoglobulin-like receptors has led to a search for their role in human disease. Due to their polymorphism and also that of their human leukocyte antigen class I ligands, these studies are difficult to perform and complex to interpret. Nevertheless, as the number of data sets increase, consistent trends and themes are beginning to emerge in both viral and inflammatory disorders. In this review, we summarize the findings from a number of disease association studies and discuss these in the context of the activating and inhibitory roles of the members of this gene family.

Uterine natural killer cells: a specialized differentiation regulated by ovarian hormones

In adult females of many species, a transient population of natural killer (NK) cells appears in cycles within the uterine endometrium (lining). Appearance of these lymphocytes coincides with specific phases of the ovarian hormone cycle and/or early pregnancy. Studies in rodents, women, and pigs dominate the literature and suggest the uterine (u)NK cells are an activated subset sharing many but not all features with circulating or lymphoid organ-residing NK cells. During successful murine pregnancy, uNK cells appear to regulate initiation of structural changes in the feed arterial systems that support maternal endometrial tissue at sites of implantation and subsequent placental development. These changes, which reverse after pregnancy, create a higher volume arterial bed with flaccid vessels unresponsive to vasoactive compounds. These unique pregnancy-associated arterial changes elevate the volume of low-pressure, nutrient-rich, maternal arterial blood available to conceptuses. Regulation of the differentiation, activation, and functions of uNK cells is only partially known, and there is lively debate regarding whether and how uNK cells participate in infertility or spontaneous abortion. This review highlights the biology of uNK cells during successful pregnancy.

Increased cystatin C expression in the pre-eclamptic placenta

Trophoblast invasion is regulated by proteinases and their inhibitors. Cystatin C inhibits cysteine proteinases. The serum concentration of cystatin C is increased in late pregnancy and pre-eclampsia. We aimed to investigate whether the expression of cystatin C is increased in the pre-eclamptic placenta and to investigate the expression pattern of cystatin C mRNA and protein in placental tissue. Tissue samples from the central part of the placenta from 13 normal and 22 pre-eclamptic pregnancies were included. We used real-time polymerase chain reaction (RT-PCR) and in situ hybridization for mRNA expression analysis and immunohistochemistry and Western blotting for protein expression analysis. RT-PCR showed a significantly higher expression of cystatin C mRNA in pre-eclampsia than in normal pregnancy, with the highest expression in cases with severe pre-eclampsia. In situ hybridization revealed a distinct pattern of high expression in the extravillous trophoblast cells of the basal plate and low expression in the syncytiotrophoblast covering villi. The cystatin C protein distribution matched the mRNA expression pattern. Western blot analysis revealed an increased protein expression in cases with severe pre-eclampsia and confirmed the presence of cystatin C in amniotic fluid samples. The high expression of cystatin C mRNA in the extravillous trophoblast cells of the basal plate suggests a role for cystatin C in the regulation of proteases in placentation. Placental expression and secretion of cystatin C could contribute to the elevated maternal plasma levels seen in pre-eclampsia.

Elevated Plasma Levels of Interleukin 1β, Tumour Necrosis Factor α and Monocyte Chemotactic Protein 1 Are Associated with Pregnancy Toxaemia in Ewes

Pregnancy toxaemia is a metabolic disorder that results from an inadequate energy supply to the growing maternal-fetal unit. The mechanism underlying the pathogenesis of the syndrome has not been fully clarified; however, a key role for cytokines and chemokines including interleukin 1 beta (IL-1 beta), tumour necrosis factor alpha (TNF-alpha) and monocyte chemotactic protein 1 (MCP-1) has been indicated in women and experimental animals. However, information on the maternal plasma levels of IL-1 beta, TNF-alpha and MCP-1 in ewes with pregnancy toxaemia is limited. Thus, the present study was designed to determine plasma IL-1 beta, TNF-alpha and MCP-1 concentrations in ewes with severe (n=6) and mild (n=4) naturally occurring pregnancy toxaemia and in uncomplicated pregnant ewes (n=10) using enzyme-linked immunosorbent assay (ELISA). All ewes with pregnancy toxaemia had significantly lower body temperature and respiratory rate than uncomplicated pregnant ewes (p<0.05). With the highest concentrations in severe cases, heart rate, proteinuria and serum uric acid levels as well as plasma IL-1 beta, TNF-alpha and MCP-1 were significantly different among all three groups (p<0.05). The plasma concentrations of IL-1 beta in control ewes and ewes with mild and severe toxaemia were 15.81 +/- 3.90 pg/ml, 23.83 +/- 2.42 pg/ml and 34.55 +/- 8.03 pg/ml, respectively. The plasma concentrations of TNF-alpha in control ewes and ewes with mild and severe toxaemia were 7.71 +/- 1.61 pg/ml, 16.13 +/- 3.63 pg/ml, and 22.85 +/- 3.64 pg/ml, respectively. The plasma concentrations of MCP-1 in control ewes and ewes with mild and severe toxaemia were 101.70 +/- 9.86 pg/ml, 134.75 +/- 6.24 pg/ml, and 157.67 +/- 9.69 pg/ml, respectively. Moreover, plasma IL-1 beta, TNF-alpha and MCP-1 levels were positively correlated with clinical and well-establish biochemical parameters of pregnancy toxaemia, serum uric acid and proteinuria (p<0.01). Concomitant increase of plasma IL-1 beta, TNF-alpha and MCP-1 concentrations along with serum uric acid, proteinuria, and worsening of the clinical signs indicates that such cytokines are involved in the aetiopathogenesis and in perpetuation of the local and systemic inflammatory reactions in pregnancy toxaemia in ewes. Hence, plasma IL-1 beta, TNF-alpha and MCP-1 may potentially serve as markers to monitor prognosis of pregnancy toxaemia in ewes.

Oxidative stress and the induction of cyclooxygenase enzymes and apoptosis in the murine placenta

Placental oxidative stress has been implicated in many complications of human pregnancy, including preterm delivery and preeclampsia. It is now appreciated that reactive oxygen species can induce a spectrum of changes, ranging from homeostatic induction of enzymes to apoptotic cell death. Little is known regarding the occurrence of placental oxidative stress in other species. We investigated markers of oxidative stress in the labyrinthine (LZ) and junctional (JZ) zones of the murine placenta across gestational age, and correlated these with expression of the cyclooxygenase enzymes COX-1 and COX-2, and apoptosis. We tested a causal link between the two by subjecting placental explants to hypoxia-reoxygenation (H/R) in vitro, a known stimulus for generation of oxidative stress. Western blotting demonstrated significant increases in the concentrations of hydroxynonenal (HNE), COX-1 and COX-2 with gestational age. Dual-labelling demonstrated co-localisation of HNE, and COX-1 and COX-2 within the trophoblast of the LZ, and glycogen cells of the JZ. An apoptotic index based on TUNEL-positivity demonstrated an increase with gestational age, and dual-labelling showed co-localisation of TUNEL labelling with HNE and active caspase-3 within the trophoblast of the LZ. H/R significantly increased oxidative stress, induction of COX-1 and COX-2, and the apoptotic index. Co-localisation demonstrated the increases in COX to be within the trophoblast of the LZ, and in particular the glycogen cells of the JZ. Apoptosis was restricted to the LZ. We speculate that the induction of COX enzymes is a physiological response to oxidative stress, and may play a role in initiating or augmenting parturition. Generation of oxidative stress may also play a role in influencing the growth trajectory of the placenta, and its component cell types. The mouse may provide an experimental genetic model in which to investigate these phenomena.

Occurrence of neutrophil extracellular DNA traps (NETs) in pre-eclampsia: a link with elevated levels of cell-free DNA?

Manifest pre-eclampsia is associated with activation of peripheral neutrophils as well as elevations in maternal cell-free DNA. For this reason, we were very intrigued by recent reports indicating that activated circulatory neutrophils secrete nuclear DNA to generate extracellular DNA lattices, termed NETs (neutrophil extracellular traps). Our preliminary data indicate that placental syncytiotrophoblast microparticles, which are released in elevated amounts in pre-eclampsia, can induce NETs in isolated neutrophils. Furthermore, we found evidence for the increased presence of NETs directly in the intervillous space of pre-eclamptic placentae. Therefore, these newly discovered entities may be implicated in the underlying etiology of this disorder.

Immunoregulation in normal pregnancy and pre-eclampsia: an overview

Pre-eclampsia is a major disorder of human pregnancy, which may have an immunological basis. It is a disease of two stages. The first stage concerns the relative failure of early trophoblast invasion and remodelling of the spiral arteries, leading to a poor blood supply to the placenta, exposing it to oxidative stress. The inadequate trophoblast invasion may result from decreased expression of human leukocyte antigen-G (HLA-G) leading to an abnormal interaction with decidual natural killer (NK) cells, which are believed to play a major role in these processes through the production of immunoregulatory cytokines and angiogenic factors. Recent evidence suggests that the interaction between trophoblast human leukocyte antigen-C (HLA-C) molecules and decidual NK cell receptors may be the point at which the apparent partner specificity of the disease originates. The second stage is the maternal syndrome, which is characterized by a generalized systemic inflammatory response involving both leukocytes and endothelium. The inflammatory stimulus is believed to come from the placenta. In pre-eclampsia, placental oxidative stress may lead to increased shedding of apoptotic and/or necrotic syncytiotrophoblast debris into the maternal circulation. There is evidence that such trophoblast debris interacts with maternal leukocytes and endothelial cells to stimulate the release of proinflammatory cytokines, which could then trigger the maternal disease.

Cultural competency: Agenda for Cultural Competency Using Literature and Evidence

BACKGROUND

Cultural competency has been recognized as an important issue relevant to all health professions. A research agenda is needed to establish a systematic approach to developing an understanding of factors relevant to the delivery of culturally competent health care.

OBJECTIVE

Within the context of existing literature, evidence-based, concrete recommendations are developed as an Agenda for Cultural Competency Using Literature and Evidence (ACCULTURE).

METHODS

First, key points representing opportunities for intervening in promotion of cultural competent health care are discussed. Following is a review of existing literature with a focus on identifying next steps for future research. Recommendations for licensing, education, and continuing education requirements suggest developing educational research establishing course content and delivery strategies that have measurable impact on improving cultural competency. In addition, existing initiatives need to be evaluated regarding effectiveness in recruiting, retaining, and preparing a diverse workforce. Patient care recommendations focus on further developing an understanding of the factors impacting health outcomes for culturally diverse patients.

RESULTS

Further work is needed for translating theoretically-based research into concrete curricula maintaining evidence-based outcomes. It is important to continue with promoting policies ensuring that research and clinical trials include diverse samples and a broad range of variables implicated in differential outcomes.

CONCLUSIONS

Based on connections between cultural competency and workforce diversity established within existing literature, data are needed regarding the effectiveness of existing initiatives promoting scholarships, grants, and incentives for improving workforce diversity and funding research on diversity issues. Finally, additional research is needed to evaluate existing and new policies for funding services and access for health services.

Cell-free mRNA concentrations of CRH,PLAC1, and selectin-P are increased in the plasma of pregnant women with preeclampsia

OBJECTIVE

To compare mRNA concentrations of corticotrophin-releasing hormone (CRH), placenta specific-1 (PLAC1), and selectin-P in preeclamptic and normal pregnancies.

METHODS

Peripheral blood samples were obtained from 43 pregnant women with preeclampsia and 41 control subjects. Plasma was harvested from samples and RNA extracted. Plasma RNA was analyzed using reverse transcription polymerase chain reaction (PCR) assay. Median concentrations of CRH, PLAC1, and selectin-P mRNA in plasma were compared, to assess possible differences in distribution. Data were also stratified and compared according to clinical severity of preeclampsia. Finally, CRH, PLAC1, and selectin-P were plotted against quantitative distributions of blood pressure and proteinuria.

RESULTS

All markers were differently distributed between cases and controls. Median values in subgroups correlated with severity of preeclampsia. All markers correlated with both. Selectin-P was identified as the marker with the highest degree of correlation. No correlation was found between any markers in the control group and proteinuria or blood pressure.

CONCLUSION

CRH, PLAC1, and selectin-P are distributed differently in preeclampsia cases compared to controls and correlate with signs of preeclampsia.

Innate immune response by ficolin binding in apoptotic placenta is associated with the clinical syndrome of preeclampsia

BACKGROUND

Unidentified circulating factors derived from placenta are thought to be responsible for the exaggerated systemic inflammation leading to preeclampsia. Our aim was to identify the circulating factors present in preeclampsia and to investigate their relationship to the underlying systemic immune response responsible for the associated clinical manifestations.

METHODS

We obtained blood samples from pregnant women with and without preeclampsia and performed comparative proteomic analyses to identify the abnormal circulating factors by 2-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight for protein separation and identification. In placentas from preeclamptic pregnancies, we evaluated the potential role of the candidate proteins identified by Western and immunohistochemical analysis. We also used proinflammatory cytokine antibody arrays to investigate local and systemic immune responses.

RESULTS

We found that ficolins, the pattern-recognition proteins involved in the lectin-complement pathway, were differentially expressed in plasma from preeclamptic pregnancies. Ficolins were present in low concentrations in plasma but at high concentrations in the placenta, particularly in syncytiotrophoblasts undergoing apoptosis. The binding of ficolins in apoptotic trophoblasts induced innate immunity through local and systemic cytokine activation and correlated with the clinical manifestation of preeclampsia.

CONCLUSIONS

We identified specific in vivo circulating factors derived from the placenta that are responsible for the local immune recognition and systemic inflammatory response in the development of clinical manifestations of preeclampsia. These findings may have predictive value and also therapeutic applications to lessen adverse clinical outcomes of preeclampsia.

Inositol Phosphoglycan P-Type in Preeclampsia

A state of insulin resistance has been demonstrated in active preeclampsia, and women with clinical evidence of insulin resistance are at higher risk to develop this syndrome during pregnancy. Recently, inositol phosphoglycan P-type, a putative second messenger of insulin action, has been implicated in the pathophysiology of preeclampsia and is increased in the placenta, amniotic fluid, and maternal urine of preeclamptic women compared with normal pregnant women. We report here a case–control study to assess the potential of urinary levels of inositol phosphoglycan P-type as a screening test for preeclampsia. Twenty-seven preeclamptic women and 47 healthy pregnant women were recruited. A polyclonal antibody-based ELISA was developed to detect levels of inositol phosphoglycan P-type in urine. Its content in urinary specimens was found to be 30-fold higher in preeclamptic subjects than control subjects (329.1±21.8 versus 9.2±1.5; P <0.001), with a higher level in all of the preeclamptic cases. For 6 women who developed preeclampsia, >1 gestational date sample of urine was available, and retrospective analysis showed a significant time-related increase of the urinary level of inositol phosphoglycan P-type ≤7 weeks before clinical diagnosis of preeclampsia. Urinary level of inositol phosphoglycan P-type increased after diagnosis indicating a possible pathophysiological threshold level and steeply decreased after delivery.

Fetal growth restriction is associated with reduced FasL expression by decidual cells

The Fas-Fas ligand (FasL) system contributes to immune tolerance at the feto-maternal site and has been ascribed a role in implantation and placental development by regulating trophoblast invasion and spiral artery remodelling. In the present study, we have examined FasL expression in decidual tissue from pregnancies with impaired placental development. Women with pre-eclampsia (PE) and/or fetal growth restriction (FGR) were enrolled as cases (n=33), and women with normal pregnancies were used as controls (n=27). Decidua basalis tissue was obtained by vacuum suction of the placental bed after delivery. FasL expression by extravillous trophoblasts (EVTs) and decidual cells (DeCs), together with EVT apoptosis, were assessed by immunohistochemistry. Levels of soluble FasL in maternal serum and apoptosis-related gene expression in decidual tissue were determined. The proportion of FasL-expressing DeCs was high in controls (72.0+/-10.2%), with a significant reduction among cases (58.1+/-19.7%; p=0.002), especially in those with FGR (54.3+/-19.9%; p<0.001). EVTs had a lower proportion of FasL expression than DeCs, with a less pronounced reduction in cases compared to controls (10.9+/-3.9 and 8.3+/-4.0%, respectively; p=0.02). Decidual FasL expression correlated with placental growth. The EVT apoptosis rate did not differ between cases and controls (1.1+/-1.9 and 1.1+/-1.3%, respectively). These findings indicate a reduction of immune privilege in decidua of PE/FGR pregnancies by reduced FasL expression and that DeCs may have a central role in the Fas-FasL-based feto-maternal immune balance.

Stranger in a strange land

Mammalian mothers and their embryos/fetuses are almost invariably genetically different, which raises the question of how the mother's immune system is diverted so as to permit cohabitation with the 'foreign' body. Several decades of research have shown that multiple cooperative systems sanction uteroplacental immune privilege. These systems include production of several varieties of soluble immunosuppressive molecules in the uterus and the placenta and strict regulation of the molecules expressed on or by placental trophoblast cells. Trophoblast, a unique lineage without counterpart in adult tissues, is in direct contact with maternal blood and tissue. The major graft rejection-promoting molecules, human leukocyte antigens (HLAs), are tightly regulated in these cells, with none of HLA-A, HLA-B, or HLA class II antigens expressed. The HLA class Ib antigens, HLA-E, HLA-F, and HLA-G, are detectable on some subpopulations. Our studies have focused on the expression, regulation, and functions of the soluble isoforms of HLA-G, which circulate in maternal blood and are present at high levels in the pregnant uterus. These isoforms are derived from the single HLA-G gene by alternative splicing and are now known to have immunosuppressive properties. Ours and other studies indicate that soluble HLA-G proteins may comprise a unique tolerogenic system for establishing local immune privilege during pregnancy.

Candidate-gene association study of mothers with pre-eclampsia, and their infants, analyzing 775 SNPs in 190 genes

Pre-eclampsia (PE) affects 5-7% of pregnancies in the US, and is a leading cause of maternal death and perinatal morbidity and mortality worldwide. To identify genes with a role in PE, we conducted a large-scale association study evaluating 775 SNPs in 190 candidate genes selected for a potential role in obstetrical complications. SNP discovery was performed by DNA sequencing, and genotyping was carried out in a high-throughput facility using the MassARRAY(TM) System. Women with PE (n = 394) and their offspring (n = 324) were compared with control women (n = 602) and their offspring (n = 631) from the same hospital-based population. Haplotypes were estimated for each gene using the EM algorithm, and empirical p values were obtained for a logistic regression-based score test, adjusted for significant covariates. An interaction model between maternal and offspring genotypes was also evaluated. The most significant findings for association with PE were COL1A1 (p = 0.0011) and IL1A (p = 0.0014) for the maternal genotype, and PLAUR (p = 0.0008) for the offspring genotype. Common candidate genes for PE, including MTHFR and NOS3, were not significantly associated with PE. For the interaction model, SNPs within IGF1 (p = 0.0035) and IL4R (p = 0.0036) gave the most significant results. This study is one of the most comprehensive genetic association studies of PE to date, including an evaluation of offspring genotypes that have rarely been considered in previous studies. Although we did not identify statistically significant evidence of association for any of the candidate loci evaluated here after adjusting for multiple testing using the false discovery rate, additional compelling evidence exists, including multiple SNPs with nominally significant p values in COL1A1 and the IL1A region, and previous reports of association for IL1A, to support continued interest in these genes as candidates for PE. Identification of the genetic regulators of PE may have broader implications, since women with PE are at increased risk of death from cardiovascular diseases later in life.

Subinvolution of the placental site as an anatomic cause of postpartum uterine bleeding: a review

CONTEXT

Subinvolution of the placental site is an anatomic cause of delayed postpartum uterine bleeding that may be underrecognized by general surgical pathologists.

OBJECTIVE

To review the physiology of uteroplacental arterial development and normal postpartum involution, and to present the characteristic clinical and histopathologic features of subinvolution.

DATA SOURCES

Literature review (MEDLINE via PubMed and Ovid) regarding the pathology and pathophysiology of placental site subinvolution. Review of the clinical and pathologic characteristics of our own institution's previously diagnosed cases of subinvolution from hysterectomy and endomyometrial curettage specimens.

CONCLUSIONS

Surgical pathologists must be aware of the cardinal histopathologic findings of subinvolution, and this diagnosis must be considered in every postpartum curettage or hysterectomy specimen presented to the surgical pathologist. Subinvolution of the placental site is an important diagnosis, as this process implies an idiopathic cause, rather than an iatrogenic cause, of postpartum uterine bleeding. The etiology of placental site subinvolution remains poorly characterized.

Matrix metalloproteinase-9 gene -1562C/T polymorphism mitigates preeclampsia

Although the aetiology of preeclampsia is unknown, there is substantial evidence that it finds its roots in abnormal placentation. Prerequisites for successful placentation include trophoblast invasion, degradation and remodelling of the uterine decidual extracellular matrix, and apoptosis without thrombosis. We tested this hypothesis by analysing the effect of functional polymorphisms in the genes coding for MMP9, MMP3 and annexin A5 on the risk of preeclampsia using a case-control design. In 163 women with preeclampsia and 163 controls we studied the association with polymorphisms in the MMP9 (-1562 C/T), MMP3 (-1612 5A/6A) and annexin A5 (-1 C/T) genes using logistic regression analysis. A lower prevalence of the rare T allele of the MMP9 (-1562 C/T) polymorphism in women with preeclampsia was found (odds ratio 0.48, 95% confidence interval 0.25-0.90). The distribution of the MMP3 (-1612 5A/6A) and annexin A5 (-1 C/T) gene polymorphisms were similar in cases and controls. Our results suggest that the MMP9-1562T allele is associated with a reduced risk of preeclampsia and therefore may protect against maladaptation of the spiral arteries and decreased decidual degradation. The elevated MMP9 concentrations reported to be associated with the -1562T allele might be essential for the development of an adequate maternal-fetal interface early in pregnancy by facilitating trophoblast apoptosis and degradation.

Expression and characterization of vitamin C transporter in the human trophoblast cell line HTR-8/SVneo: effect of steroids, flavonoids and NSAIDs

Vitamin C plays an important role in embryogenesis and fetal growth as well as in the progression of pregnancy and delivery. Therefore, it is important to understand the mechanism that mediates its transport to the fetus as well as the possible influences by endogenous and exogenous substances on its placental uptake. The aim of this study was to investigate placental sodium-dependent vitamin C transporters (SVCT) 1 and 2. By means of RT-PCR, we found that SVCT2, but not SVCT1, mRNA is expressed in human trophoblast cell line HTR-8/SVneo. Our method was able to confirm SVCT2 mRNA expression in human first-trimester chorionic villi but not in term placental tissue. Cell line kinetic studies of [(14)C] ascorbic acid (AA) uptake indicated a one-site model and a saturable process. Fetal bovine serum (FBS) and epidermal growth factor (EGF) do not influence the transport properties, although they significantly increase the expression of SVCT2. Steroid hormones (17beta-estradiol, progesterone and cortisol), flavonoids (genistein and quercetin) and non-steroidal anti-inflammatory drugs (NSAIDs) (indomethacin and diclofenac) inhibit [(14)C]AA uptake in a dose-dependent and non-competitive manner. On the contrary, the process is not influenced by aspirin. Our study suggests the use of HTR-8/SVneo cells as a suitable model for trophoblast vitamin C transport investigation.

Expressional and epigenetic alterations of placental serine protease inhibitors: SERPINA3 is a potential marker of preeclampsia

Preeclampsia is the major pregnancy-induced hypertensive disorder. It modifies the expression profile of placental genes, including several serine protease inhibitors (SERPINs). The objective of this study was to perform a systematic expression analysis of these genes in normal and pathological placentas and to pinpoint epigenetic alterations inside their promoter regions. Expression of 18 placental SERPINs was analyzed by quantitative RT-PCR on placentas from pregnancies complicated by preeclampsia, intrauterine growth restriction, or both and was compared with normal controls. SERPINA3, A5, A8, B2, B5, and B7 presented significant differences in expression in >or=1 pathological situation. In parallel, the methylation status of the CpG islands located in their promoter regions was studied on a sample of control and preeclamptic placentas. Ten SERPIN promoters were either totally methylated or totally unmethylated, whereas SERPINA3, A5, and A8 presented complex methylation profiles. For SERPINA3, the analysis was extended to 81 samples and performed by pyrosequencing. For the SERPINA3 CpG island, the average methylation level was significantly diminished in preeclampsia and growth restriction. The hypomethylated CpGs were situated at putative binding sites for developmental and stress response (hypoxia and inflammation) factors. Our results provide one of the first observations of a specific epigenetic alteration in human placental diseases and provide new potential markers for an early diagnosis.

Use of a gestational carrier for a patient with recurrent adverse pregnancy outcomes from early onset severe pre-eclampsia

OBJECTIVE

To describe the first reported case of gestational carrier treatment to prevent severe early onset pre-eclampsia.

DESIGN

Case report.

SETTING

A university-based reproductive endocrinology and infertility clinic and a tertiary care hospital.

PATIENT(S)

A 29-year-old woman and her husband with three consecutive pregnancies complicated by early onset severe pre-eclampsia causing fetal demises at 22 and 24 weeks gestation; a neonatal death at 25 weeks gestation; and life-threatening maternal hemolysis, elevated liver enzymes, and low platelets.

INTERVENTION(S)

An IVF procedure in the patient using her husband's sperm with the transfer of two embryos to a friend who offered to be a gestational carrier.

MAIN OUTCOME MEASURE(S)

Successful IVF cycle in the patient and uncomplicated pregnancy and delivery in the gestational carrier.

RESULT(S)

The gestational carrier achieved a pregnancy and progressed without complications to delivery of a healthy, 3.2-kg infant at 39 weeks gestation.

CONCLUSION(S)

The use of a gestational carrier deserves consideration as a treatment option in patients with poor reproductive histories because of early onset severe pre-eclampsia and hemolysis, elevated liver enzymes, and low platelets syndrome. This experience also suggests that development of pre-eclampsia may be in large part maternally rather than embryologically or paternally driven.

Hypertension and maternal-fetal conflict during placental malaria

BACKGROUND

Malaria and hypertension are major causes of maternal mortality in tropical countries, especially during first pregnancies, but evidence for a relationship between these syndromes is contradictory.

METHODS AND FINDINGS

In a cross-sectional survey of Tanzanian parturients, the rate of hypertension was similar in placental malaria (PM)-positive (11/85 = 13%) and PM-negative (73/602 = 12%) individuals. However, we found that PM was associated with hypertension in first-time mothers aged 18-20 y but not other mothers. Hypertension was also associated with histologic features of chronic malaria, which is common in first-time mothers. Levels of soluble vascular endothelial growth factor receptor 1 (sVEGFR1), a preeclampsia biomarker, were elevated in first-time mothers with either PM, hypertension, or both, but levels were not elevated in other mothers with these conditions. In first-time mothers with PM, the inflammatory mediator vascular endothelial growth factor (VEGF) was localized to maternal macrophages in the placenta, while sVEGFR1, its soluble inhibitor, was localized to the fetal trophoblast.

CONCLUSIONS

The data suggest that maternal-fetal conflict involving the VEGF pathway occurs during PM, and that sVEGFR1 may be involved in the relationship between chronic PM and hypertension in first-time mothers. Because placental inflammation causes poor fetal outcomes, we hypothesize that fetal mechanisms that promote sVEGFR1 expression may be under selective pressure during first pregnancies in malaria-endemic areas.

Aberrant Uterine Natural Killer (NK)-Cell Expression and Altered Placental and Serum Levels of the NK-Cell Promoting Cytokine Interleukin-12 in Pre-Eclampsia

PROBLEM

Natural killer (NK) cells are the most abundant lymphocyte population at the maternal-fetal interface. They are suggested to be important during placentation by controlling trophoblast invasion. If placentation is suboptimal, pre-eclampsia can occur.

METHOD OF STUDY

Decidual NK (dNK) cells were examined at delivery in 46 women, 22 pre-eclamptic women and 24 healthy controls, by staining for CD56 and CD94 with immunohistochemistry (IHC). Furthermore, we investigated the placental expression and the serum levels of the NK-cell activating cytokines interleukin(IL)-12, IL-15, IL-18 and the anti-inflammatory cytokine IL-10 by IHC and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

Pre-eclamptic women had higher number of CD56+ and CD94+ cells in the decidua, indicating an altered receptor expression of dNK cells. We also demonstrate for the first time that the villous trophoblasts show strong immunostaining for IL-12 in placentae from healthy controls, while women suffering from pre-eclampsia have significantly less IL-12. However, pre-eclamptic women had significantly elevated IL-12 and IL-15 levels in serum.

CONCLUSION

Results show increased numbers and altered phenotype of dNK cells in pre-eclampsia, supporting the importance of these cells for a healthy pregnancy. The altered receptor expression of dNK cells together with diminished placental IL-12 expression could implicate an altered NK cell-regulation in pre-eclampsia.

Vasoreactivity of chorionic plate arteries in response to vasoconstrictors produced by preeclamptic placentas

Inadequate blood flow and increased vasoconstriction of the placenta contribute to pregnancy associated disorders such as preeclampsia (PE). Because placental vessels lack autonomic innervation, humoral effects of the placenta must play critical roles in regulation of fetal-placental vascular contractility. In this study, we examined the nature of humoral factors produced by PE trophoblasts on placental vessel contractility using an organ bath perfusion model. Vasomotor responses were studied in vitro using placental chorionic plate arteries. Vessel rings from third branch chorionic plate arteries were dissected from human placentas following normal or PE delivery. The arterial rings were equilibrated in Krebs Henseleit buffer and exposed to placental conditioned medium, which was prepared by culture of villous tissue from PE placentas. Receptor antagonists for angiotensin II (ANG II), thromboxane (TX), and endothelin (ET) were used to determine which humoral factor produced by placental tissue (trophoblasts) was more effective in promoting vasoconstriction. The role of angiotensin converting enzyme (ACE) and non-ACE ANG II generating enzymes in regulation of placental vasomotor tone were also investigated. A total of 80 arterial rings from 48 placentas were studied. Our results showed: 1) enhanced vasomotor tone in arteries from PE placentas compared to those from normal placentas; 2) PE-CM induced vaso-constrictive activity could be partially attenuated by receptor antagonists for TX, ANG II and ET, respectively; and 3) chymostatin (a chymase inhibitor) produced a stronger inhibitory effect than captopril (ACE inhibitor) on PE conditioned medium induced vasoconstriction. Our data demonstrate increased vasocontractility in PE placentas and suggest that the non-ACE pathway is probably a major source of ANG II produced in the human placenta.

Maternal obesity, metabolism, and pregnancy outcomes

About one third of all pregnant women in the United States are obese. Maternal obesity at conception alters gestational metabolic adjustments and affects placental, embryonic, and fetal growth and development. Neural tube defects and other developmental anomalies are more common in infants born to obese women; these defects have been linked to poor glycemic control. Preeclampsia, a gestational disorder occurring more frequently in obese women, appears to be due to a subclinical inflammatory state that impairs early placentation and development of its blood supply. Fetal growth and development during the last half of pregnancy depends on maternal metabolic adjustments dictated by placental hormones and the subsequent oxygen and nutrient supply. Maternal obesity affects these metabolic adjustments as well. Basal metabolic rates are significantly higher in obese women, and maternal fat gain is lower, possibly in response to altered leptin function. The usual increase in insulin resistance seen in late pregnancy is enhanced in obese mothers, causing marked postprandial increases in glucose, lipids, and amino acids and excessive fetal exposure to fuel sources, which in turn increases fetal size, fat stores, and risk for disease postnatally. Impaired glucose tolerance, gestational diabetes, and hyperlipidemia are more common among obese mothers. To date, little attention has been given to the role of diet among obese women in preventing these problems. However, studies of women with impaired glucose tolerance show that replacing refined carbohydrates and saturated fat with complex, low-glycemic carbohydrates and polyunsaturated fatty acids improves metabolic homeostasis and pregnancy outcomes. Thus, current dietary guidelines regarding the amount and type of carbohydrates and fat for nonpregnant women seem appropriate for pregnant women as well.

Anti-inflammatory interventions in pregnancy: now and the future

A growing body of evidence implicates inflammatory pathways in adverse reproductive outcomes. This expanding evidence suggests that anti-inflammatory interventions may hold promise in reducing the maternal and neonatal morbidities and mortalities associated with these obstetrical complications. Preterm birth, preeclampsia, pregnancy loss and adverse neonatal outcomes have all been associated with the activation of inflammatory pathways during pregnancy. Because of the number of observational human studies, as well as animal models of preterm birth, the mechanisms by which inflammation may promote preterm parturition and adverse effects on the fetus are beginning to be elucidated. Although the future use of anti-inflammatory interventions in this context holds significant promise, much research is still warranted. Only when the pathogenesis of obstetrical complications is more fully understood can meaningful therapeutic interventions become a realistic goal.

Genetics of preeclampsia: paradigm shifts

Segregation of preeclampsia into early-onset, placental and late-onset, maternal subtypes along with the acknowledgement of the contribution of epigenetics in placentally expressed genes proved to be a key first step in the identification of essential gene variants associated with preeclampsia. Application of this insight to other populations and related pregnancy-induced syndromes, such as HELLP, and acknowledgment of the features shared between chromosomal loci associated with preeclampsia in different populations provide the rationale for new strategies for the identification of susceptibility genes and for new and more effective diagnostic strategies.