Antioxidant therapy to prevent preeclampsia

Red blood cell in preeclampsia: attenuated nitric oxide generation and enhanced reactive oxygen species formation and eryptosis

Preeclampsia (PE) pathogenesis is strongly related to diminished nitric oxide (NO) bioavailability and enhanced oxidative stress. Emerging evidence suggests that red blood cells (RBCs) eNOS enzyme contributes to systemic NO bioavailability by its ability of both NO and ROS generation. We aimed to investigate RBC eNOS enzyme activity, NO and ROS generation capacity, eryptosis index and aggregation levels in preeclamptic and uncomplicated pregnant women. Fifty-eight PE patients and 36 healthy pregnant women were included to the investigation. RBC eNOS enzyme activity, intracellular NO, calcium and ROS concentrations and eryptosis levels were determined via flow cytometric methods. RBC deformability and aggregation were measured via LORRCA. Intracellular NO and phosphorylated RBC eNOS levels decreased in PE group compared to healthy pregnant group (p < 0.05, p < 0.001 respectively). Intracellular ROS and calcium levels, eryptosis values and aggregation indexes in the PE group were significantly higher than healthy pregnant group (p < 0.05, p < 0.01, p < 0.05, p < 0.05 respectively). Our results demonstrate for the first time that RBC produce lower NO and higher ROS under PE conditions. Further, RBC of PE patients were more prone to eryptosis and aggregation compared to control group. Our results suggest that, in addition to endothelial cells, RBC also contribute to decreased plasma NO bioavailability via producing less NO and high ROS in PE. Considering increased tendency to eryptosis and aggregation, RBC seem to play role in haemodynamic changes of PE pathogenesis.

Diverse associations observed between pregnancy complications and RBC or plasma folates determined by an in-house developed LC-MS/MS method

BACKGROUND

As folates are essential for embryonic development and growth, it is necessary to accurately determine the levels of folates in plasma and red blood cells (RBCs) for clinical intervention. The aims of this study were to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantitation of folates in plasma and RBCs and to examine the association between plasma and RBC folate concentrations and gestational diabetes mellitus (GDM), gestational hypertension (GH) and preeclampsia (PE).

METHODS

With the in-house developed LC-MS/MS, a retrospective cross-sectional study was conducted. The healthy pregnant women of first- (n = 147), second- (n = 84) and third-trimester (n = 141) or the women diagnosed with GDM (n = 84), GH (n = 58) or PE (n = 23), that were aged between 22 and 46 years old and registered at our institute, were subjected for measurement of folic acid (FA) and 5-methyltetrahydrofolate (5-MTHF), followed by appropriate statistical association analysis.

RESULTS

The assay for simultaneous quantitation of FA and 5-MTHF in plasma and RBCs was linear, stable, with imprecision less than 15% and recoveries within ±10%. The lower limits of quantification for FA and 5-MTHF measurement in whole blood were 0.57 and 1.09 nmol/L, and in plasma were 0.5 and 1 nmol/L, respectively. In the association analysis, the patients with lower RBC folate level (<906 nmol/L) presented higher risks of PE development (OR 4.861 [95% CI 1.411-16.505]) by logistic regression and restricted cubic spline (RCS) regression in a nonlinear fashion. In addition, higher level of plasma folates in pregnancy was significantly associated with GH risk but may be protective for the development of GDM.

CONCLUSIONS

The in-house developed LC-MS/MS method for folates and metabolites in plasma or RBC showed satisfactory analytical performance for clinical application. Further, the levels of folates and metabolites were diversely associated with GDM, GH and PE development.

Low-dose aspirin inhibits trophoblast cell apoptosis by activating the CREB/Bcl-2 pathway in pre-eclampsia

Excessive apoptosis of placental trophoblast cells is considered a major cause of pre-eclampsia (PE) pathogenesis. Phosphorylation of the widely expressed cAMP response element binding protein (CREB) regulates apoptosis and may be involved in PE incidence. Low-dose aspirin (LDA) is an effective approach for preventing PE with unclear mechanisms. Thus we examined whether LDA protects against PE by inhibiting trophoblast cell apoptosis through CREB. The effects of LDA on human PE placenta, PE model rat placenta, and hydrogen peroxide (H2O2)-induced HTR-8/SVneo cell apoptosis were analyzed. TUNEL assay, immunohistochemistry, Cell Counting Assay Kit-8 (CCK-8) assay, western blot, and flow cytometry assay were performed. In the placenta of human PE and rat PE models, the TUNEL index increased and was partially corrected with LDA pre-treatment. Meanwhile, decreased Bcl-2 and increased Bax expression were significantly reversed by LDA pre-treatment. In HTR-8/SVneo cells, H2O2 decreased cell viability, promoted apoptosis, reduced the Bcl-2/Bax ratio, aggravated loss of mitochondrial membrane potential (MMP), increased cytoplasmic cytochrome c release, and simultaneously activated caspase-9 and caspase-3. These effects were effectively restored by LDA pre-treatment in the cells. Moreover, LDA promoted CREB phosphorylation in trophoblast cells. CREB interference further promoted apoptosis, reduced the Bcl-2/Bax ratio, and increased MMP loss. CREB interference also reversed the inhibitory effect of LDA on H2O2-induced apoptosis in HTR-8/SVneo cells. Thus, LDA was shown to inhibit trophoblast cell mitochondrial apoptosis by activating the CREB/Bcl-2 pathway, providing novel evidence for the protective mechanism of LDA in PE.Abbreviations; PE: Pre-eclampsia; LDA: low-dose aspirin; CREB: cAMP response element binding protein; ROS: reactive oxygen species; H2O2: hydrogen peroxide; PBS: Phosphate-buffered saline; Bcl-2: B-cell lymphoma-2; MMP: Mitochondrial membrane potential; Cyt-c: CytochromeC.

CTHRC1 promotes growth, migration and invasion of trophoblasts via reciprocal Wnt/β-catenin regulation

Preeclampsia (PE) is a pregnancy complication that is characterized by high blood pressure and is associated with high maternal and fetal morbidities. At a mechanistic level, PE is characterized by reduced invasion ability of trophoblasts. Collagen triple helix repeat containing-1 (CTHRC1) is a well-known tumor-promoting factor in several malignant tumors, but its role in trophoblasts remains unknown. In this study, we characterized the expression of CTHRC1 in placenta tissue samples from PE pregnancies and from normal pregnancies. We used the trophoblasts cell lines HTR-8/SVneo and JEG-3 to investigate the role of CTHRC1 in cell migration, invasion and proliferation. Western blot, PCR and TOP/FOP luciferase activity assays were used to investigate the molecular mechanisms underlying these cell behaviors. Placenta tissue samples obtained from pregnant women with PE expressed lower levels of CTHRC1 than those of placenta tissues from women with normal pregnancies. Down-regulation of CTHRC1 impaired cell proliferation, migration and invasion of trophoblasts, while CTHRC1 overexpression promoted nuclear translocation of β-catenin, a result that was further confirmed by TOP/FOP luciferase activity assay. Our findings suggest that CTHRC1 promotes migration and invasion of trophoblasts via reciprocal Wnt/β-catenin signaling pathway. Down-regulation of CTHRC1 may be a potential mechanism underpinning the development of preeclampsia.

Effect of high-dose folic acid supplementation on the prevention of preeclampsia in twin pregnancy

Objective: To determine the efficacy of high-dose folic acid for the prevention of preeclampsia in twin pregnancies.Methods: Secondary analysis of a randomized controlled trial in 70 obstetrical sites in Argentina, Australia, Canada, Jamaica, and the UK between 2011 and 2015. Eligible women pregnant with twins who were aged 18 y or older and between 8 and 16 completed weeks' gestation were randomized between to receive daily high-dose folic acid (4.0-5.1 mg) or placebo. The primary outcome was preeclampsia, presenting as hypertension after 20 weeks' gestation with significant proteinuria. Secondary outcomes included severe preeclampsia, preterm birth, and adverse fetal and neonatal outcomes.Results: Of 2464 participants randomized between 18 April 2011 and 14 December 2015, 462 (18.8%) had a confirmed twin pregnancy. Thirty-four of these participants withdrew consent or did not have primary outcome data available, and 428 women were analyzed. The rate of preeclampsia was significantly higher in the folic acid group compared to the placebo group in crude analyses (17.2 versus 9.9%; relative risk 1.75 [95% CI 1.06-2.88], p = .029). Multivariable analyses attenuated this effect, rendering it not statistically significant (RR 1.58 [95% CI 0.95-2.63], p = .079).Conclusion: High-dose folic acid supplementation was not significantly associated with preeclampsia in a subgroup of twin pregnancies. Although a suggested elevated risk cannot be confirmed, these results may help to gain novel insights in the etiology of preeclampsia, which continues to be poorly understood.Clinical trial registration: ClinicalTrials.gov NCT01355159.

The Role of Melatonin in Oxidative Stress, DNA Damage, Apoptosis and Angiogenesis in Fetal Eye under Preeclampsia and Melatonin Deficiency Stress

Aim: The aim of this study was to investigate the possible mechanisms of ocular damage induced by pinealectomy (PNX) and preeclampsia (PE), and to determine the cellular and molecular effects of melatonin treatment on oxidative stress, DNA damage, molecular chaperone responses, induction of apoptosis and angiogenesis in the fetal eye of both PNX and PNX+PE animals. Material and Methods: We analysed therapeutic potential of melatonin on fetal eye damage in PNX and PNX+PE animals using Malondialdehyde (MDA), Random Amplified Polymorphic DNA (RAPD), qRT-PCR and Western blot assays. Results: Our study presents three preliminary findings: (a) in fetal eye tissues, PNX and PNX+PE significantly induce oxidative damage to both DNA and protein contents, leading to a dramatic increase in caspase-dependent apoptotic signalling in both mitochondrial and death receptor pathways; (b) the same conditions trigger hypoxia biomarkers in addition to significant overexpression of HIF1-α, HIF1-β, MMP9 and VEGF genes in the fetal eye; (c) finally, melatonin regulates not only the expression of genes encoding antioxidant enzymes and increase in DNA damage as well as lipid peroxidation but also limits programmed cell death processes in the fetal eye of PNX and PNX+PE animals . Furthermore, melatonin can relatively modulate genes in the HIF1 family, TNF-α and VEGF, thus acting as a direct anti-angiogenic molecule. In conclusion, both PNX and PNX+PE induce ocular damage at both cellular and molecular levels in fetal eye tissue of rats. Conclusion: Our results clearly indicate the potential of melatonin as a preventative therapeutic intervention for fetal ocular damage triggered by both PNX and PNX+PE.

A perspective on pre-eclampsia and neurodevelopmental outcomes in the offspring: Does maternal inflammation play a role?

Pre-eclampsia is a leading cause of maternal death and maternal and perinatal morbidity. Whilst the clinical manifestations of pre-eclampsia often occur in late pregnancy, the molecular events leading into the onset of this disease are thought to originate in early pregnancy and result in insufficient placentation. Although the causative molecular basis of pre-eclampsia remains poorly understood, maternal inflammation is recognised as a core clinical feature. While the adverse effects of pre-eclampsia on maternal and fetal health in pregnancy is well-recognised, the long-term impact of pre-eclampsia exposure on the risk of autism spectrum disorder (ASD) in exposed offspring is a topic of on-going debate. In particular, a recent systematic review has reported an association between exposure to pre-eclampsia and increased risk of ASD, however the molecular basis of this association is unknown. Here we review recent evidence for; 1) maternal inflammation in pre-eclampsia; 2) epidemiological evidence for alterations in neurodevelopmental outcomes in offspring exposed to pre-eclampsia; 3) long-term changes in the brains of offspring exposed to pre-eclampsia; and 4) how maternal inflammation may lead to altered neurodevelopmental outcomes in pre-eclampsia exposed offspring. Finally, we discuss the implications of this for the development of future studies in this field.

Vitamins supplementation affects the onset of preeclampsia

Preeclampsia may affect between 2-8% of all pregnancies. It seriously affects maternal health after pregnancy. This meta-analysis was performed to define the efficacy of vitamins supplementation on the risk of preeclampsia. Potential articles were systematically searched on the databases of Pubmed, Embase and Web of Science up to May 2016. Relative risk (RR) and 95% confidence intervals (95%CIs) were used to analyze the relationship of vitamins supplementation with risk of preeclampsia. Cochran Q test was used to test inter-study heterogeneity. Begg's funnel plot was adopted to assess the potential publication bias. 28 eligible studies were selected. Pooled results indicated that vitamins supplementation could reduce the risk of preeclampsia (RR = 0.74, 95%CI = 0.64-0.86). The studies with non-randomized controlled trial (RCT) analysis also suggested the significant relationship of vitamins supplementation with risk of preeclampsia (RR = 0.60, 95%CI = 0.42-0.85). However, negative results were observed in studies with RCT analysis. Subgroup analysis by vitamin type was performed among the studies with RCT analysis. The results indicated that vitamin D supplementation could significantly reduce the risk of preeclampsia (RR = 0.41, 95%CI = 0.22-0.78). Similar results were observed in the studies with multivitamins supplementation (RR = 0.69, 95%CI = 0.51-0.93). Vitamins supplementation could reduce the onset of preeclampsia.

Aspirin prevents TNF-α-induced endothelial cell dysfunction by regulating the NF-κB-dependent miR-155/eNOS pathway: Role of a miR-155/eNOS axis in preeclampsia

Preeclampsia is an inflammatory disease with endothelial cell dysfunction that occurs via decreased endothelial nitric oxide synthase/nitric oxide (eNOS/NO) activity. Aspirin reduces the incidence of hypertensive pregnancy complications. However, the underlying mechanism has not been clearly explained. Here, we found that tumor necrosis factor (TNF)-α, microRNA (miR)-155, and eNOS levels as well as endothelial redox phenotype were differentially regulated in preeclamptic patients, implying the involvement of TNF-α- and redox signal-mediated miR-155 biogenesis and eNOS downregulation in the pathogenesis of preeclampsia. Aspirin prevented the TNF-α-mediated increase in miR-155 biogenesis and decreases in eNOS expression and NO/cGMP production in cultured human umbilical vein endothelial cells (HUVECs). Similar effects of aspirin were also observed in HUVECs treated with H₂O₂. The preventive effects of aspirin was associated with the inhibition of nuclear factor-κB (NF-κB)-dependent MIR155HG (miR-155 host gene) expression. Aspirin recovered the TNF-α-mediated decrease in wild-type, but not mutant, eNOS 3'-untranslated region reporter activity, whose effect was blocked by miR-155 mimic. Moreover, aspirin prevented TNF-α-mediated endothelial cell dysfunction associated with impaired vasorelaxation, angiogenesis, and trophoblast invasion, and the preventive effects were blocked by miR-155 mimic or an eNOS inhibitor. Aspirin rescued TNF-α-mediated eNOS downregulation coupled with endothelial dysfunction by inhibiting NF-κB-dependent transcriptional miR-155 biogenesis. Thus, the redox-sensitive NF-κB/miR-155/eNOS axis may be crucial in the pathogenesis of vascular disorders including preeclampsia.

Folic acid supplementation and dietary folate intake, and risk of preeclampsia

BACKGROUND/OBJECTIVES

Folic acid supplementation has been suggested to reduce the risk of preeclampsia. However, results from few epidemiologic studies have been inconclusive. We investigated the hypothesis that folic acid supplementation and dietary folate intake before conception and during pregnancy reduce the risk of preeclampsia.

SUBJECTS/METHODS

A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. A total of 10,041 pregnant women without chronic hypertension or gestational hypertension were enrolled.

RESULTS

Compared with nonusers, folic acid supplement users had a reduced risk of preeclampsia (OR=0.61, 95% CI: 0.43-0.87). A significant dose-response of duration of use was observed among women who used folic acid supplemention during pregnancy only (P-trend=0.007). The reduced risk associated with folic acid supplement was similar for mild or severe preeclampsia and for early- or late-onset preeclampsia, although the statistical significant associations were only observed for mild (OR=0.50, 95% CI: 0.30-0.81) and late-onset (OR=0.60, 95% CI: 0.42-0.86) preeclampsia. The reduced risk associated with dietary folate intake during pregnancy was only seen for severe preeclampsia (OR=0.52, 95% CI: 0.31-0.87, for the highest quartile of dietary folate intake compared with the lowest).

CONCLUSIONS

Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia. Future studies are needed to confirm the associations.

The effects of vitamin C supplementation on pre-eclampsia in Mulago Hospital, Kampala, Uganda: a randomized placebo controlled clinical trial

Background

Oxidative stress plays a role in the pathogenesis of pre-eclampsia. Supplementing women with antioxidants during pregnancy may reduce oxidative stress and thereby prevent or delay the onset pre-eclampsia. The objective of this study was to evaluate the effect of supplementing vitamin C in pregnancy on the incidence of pre-eclampsia, at Mulago hospital, Kampala, Uganda.

Methods

This was a (parallel, balanced randomization, 1:1) placebo randomized controlled trial conducted at Mulago hospital, Department of Obstetrics and Gynecology. Participants included in this study were pregnant women aged 15-42 years, who lived 15 km or less from the hospital with gestational ages between 12-22 weeks. The women were randomized to take 1000mg of vitamin C (as ascorbic acid) or a placebo daily until they delivered. The primary outcome was pre-eclamsia. Secondary outcomes were: severe pre-eclampsia, gestational hypertension, preterm delivery, low birth weight and still birth delivery. Participants were 932 pregnant women randomized into one of the two treatment arms in a ratio of 1:1. The participants, the care providers and those assessing the outcomes were blinded to the study allocation.

Results

Of the 932 women recruited; 466 were randomized to the vitamin and 466 to the placebo group. Recruitment of participants was from November 2011 to June 2012 and follow up was up to January 2013. Outcome data was available 415 women in the vitamin group and 418 women in the placebo group.

There were no differences in vitamin and placebo groups in the incidence of pre-eclampsia (3.1% versus 4.1%; RR 0.77; 95% CI: 0.37-1.56), severe pre-eclampsia (1.2% versus 1.0%; RR 1.25; 95% CI: 0.34-4.65), gestational hypertension(7.7% versus 11.5%; RR 0.67; 95% CI: 0.43-1.03), preterm delivery (11.3% versus 12.2%; RR 0.92; 95% CI: 0.63-1.34), low birth weight (11.1% versus 10.3%; RR 1.07; 95% CI: 0.72-1.59) and still birth delivery (4.6% versus 4.5%; RR 1.01; 95% CI: 0.54-1.87).

Conclusions

Supplementation with vitamin C did not reduce the incidence of pre-eclampsia nor did it reduce the adverse maternal or neonatal outcomes. We do not recommend the use of vitamin C in pregnancy to prevent pre-eclampsia.

Trial registration

This study was registered at the Pan African Clinical Trial Registry, PACTR201210000418271 on 25^th October 2012.

Calcium supplementation and prevention of preeclampsia: a meta-analysis

BACKGROUND

Since the early 1980s, epidemiological evidence has suggested a connection between low calcium intake and preeclampsia The purpose of this meta-analysis is to summarize current evidence regarding calcium supplementation during pregnancy in predicting preeclampsia and associated maternal-fetal complications.

METHODS

Literature revision of all RCT (random allocation of calcium versus placebo) available in MEDLINE/PUBMED up to 2/29/2012 regarding calcium supplementation during pregnancy for preventing preeclampsia. We used the Mantel-Haenszel's Method for four subgroup of patients: Adequate calcium intake; Low calcium intake; Low risk of preeclampsia; High risk of preeclampsia. We considered p < 0.05 as significant.

RESULTS

There is no consensus in Literature about: (1) the efficacy of calcium supplementation in the prevention of preeclampsia, (2) other/adverse/long-term effects of calcium supplementation in pregnancy.

CONCLUSIONS

Preeclampsia is likely to be a multifactorial disease. However, inadequate calcium intake represents a factor associated with an increased incidence of hypertensive disease. The results of our meta-analysis demonstrate that the additional intake of calcium during pregnancy is an effective measure to reduce the incidence of preeclampsia, especially in populations at high risk of preeclampsia due to ethnicity, gender, age, high BMI and in those with low baseline calcium intake.

FOLATE METABOLISM AND PREECLAMPSIA

Preeclampsia (PE) is a multisystem disorder of human pregnancy, affecting about 6% of all pregnancies worldwide, and is one of the leading causes of maternal and infant morbidity and mortality. Despite decades of research into the pathogenesis of this complex disease, the underlying mechanisms remain unclear. As a result, the options for prevention and management of PE are limited. In recent years, there has been a growing body of evidence suggesting that folate deficiency is associated with PE, and folic acid supplementation may reduce the risk of developing PE in certain populations. Folate contributes to cell division and growth, and folate metabolism is involved in a large number of physiological and pathophysiological processes in human development. Sufficient supply of folate is therefore particularly important during pregnancy. Nevertheless, the exact mechanisms of folic acid deficiency increasing the risk of developing PE are still unclear. This article reviews what is understood about the aetiology of PE and the relationship between folate metabolism and PE so as to enhance further discussions on the subject.

Preeclampsia and gestational diabetes mellitus: pre-conception origins?

Preeclampsia (PE) and gestational diabetes mellitus (GDM) are two of the most common medical complications of pregnancy, with risks for both mother and child. Like many other antepartum complications, PE and GDM occur only in pregnancy. However, it is not clear if pregnancy itself is the cause of these complications or it these conditions are caused by factors that existed prior to gestation. In this paper, we hypothesize that although the clinical findings of PE and GDM are first noted during pregnancy, the origins of both conditions may actually precede pregnancy. We further hypothesize that pathophysiologic changes underlying PE and GDM are present prior to pregnancy, but remain undetected in the non-gravid state either because pregnancy is the trigger that makes these pathologies become clinically detectable or because there has been limited prospective longitudinal data comparing the pre-gravid and antepartum status of women that go on to develop these conditions. Rigorous prospective cohort studies in which women undergo serial systematic evaluation in the pre-conception period, throughout pregnancy and into the postpartum are ideally needed to test this hypothesis of pre-conception origins of PE and GDM. In this context, we are creating a pre-conception cohort, involving about 5000 couples who plan to have a baby within six months in Liuyang county in the Chinese province of Hunan. Results from this pre-conception cohort program should be able to provide definitive answer to the question of whether the underpinnings of PE and GDM originate prior to pregnancy. Ultimately, the significance of addressing this hypothesis is underscored by its potential implications for targeted interventions that could be designed to (i) prevent the deleterious effects of PE/GDM and (ii) thereby interrupt the vicious cycle of disease that links affected women and their offspring.

Plasma level of soluble c-Met is tightly associated with the clinical risk of preeclampsia

OBJECTIVE

The objective of the study was to examine the relevance of the soluble form c-Met (sMet) with the clinical risk for severe preeclampsia.

STUDY DESIGN

This prospective case-control study was performed by using plasma derived from 44 preeclamptic and 51 uncomplicated pregnant women. Plasma concentration of sMet was measured with specific enzyme-linked immunosorbent assay, and the predictive values were determined based on the receiver-operating characteristic (ROC) curves analysis.

RESULTS

Plasma s-Met level in normal pregnant women changed in a gestation-dependent manner, peaking at weeks 19-24. In women with severe preeclampsia, the circulating sMet level was significantly lower than that in the gestational stage-matched controls during gestational weeks 15-30. The ROC curve analysis revealed a significant correlation between plasma sMet level and the risk of developing severe preeclampsia.

CONCLUSION

Plasma sMet could serve as a potential biomarker for predicting severe preeclampia at early second trimester of pregnancy.

Intake of vitamin C and E in pregnancy and risk of pre-eclampsia: prospective study among 57 346 women

OBJECTIVE

It has been suggested that vitamin C, alone or in combination with vitamin E, may protect against pre-eclampsia, whereas the safety of high-dose vitamin E supplements has been questioned. We investigated dietary intakes of vitamins C and E to see if they correlated with the incidence of pre-eclampsia.

DESIGN

Prospective cohort study.

SETTING

The Danish National Birth Cohort; a population-based pregnancy cohort; analyses were based on 57 346 pregnancies.

METHODS

Vitamin intake was estimated from a food frequency questionnaire completed in gestational week 25, recording intake from diet and supplements during the previous four weeks. Pre-eclampsia diagnoses were obtained from the Danish National Patient Registry; we worked with two entities, 'pre-eclampsia (all types)' and 'severe pre-eclampsia/eclampsia/HELLP'. We adjusted for confounding factors by logistic regression.

MAIN OUTCOME MEASURES

A small increase in the incidence of severe disease was also seen in the group of women (64, n = 49 373) with a high intake of vitamin E from supplements and dietary sources.

RESULTS

The incidence of 'pre-eclampsia (all types)' did not correlate with dietary vitamin C and E intake. There was a decreasing trend (P = 0.01) in the incidence of 'severe pre-eclampsia/eclampsia/HELLP' with increasing dietary vitamin C intake; with an intake of 130-170 mg/day as reference, odds ratios ranged from 1.21 (95% confidence interval 0.83 to 1.75) for an intake below 70 mg/day to 0.70 (0.40 to 1.23) for an intake exceeding 275 mg/day (total n = 57 346). For vitamin E intake aggregated from diet and supplements (n = 49 373), with an intake of 10.5-13.5 mg/day as reference, the 'severe pre-eclampsia/eclampsia/HELLP' odds ratio was 1.46 (1.02 to 2.09) for an intake exceeding 18 mg/day.

CONCLUSIONS

Low dietary intake of vitamin C was associated with a trend towards an increased incidence of either severe pre-eclampsia, eclampsia or HELLP. A small increase in the incidence of severe disease was also seen in the group of women with a high intake of vitamin E from supplements and dietary sources.

World Health Organisation multicentre randomised trial of supplementation with vitamins C and E among pregnant women at high risk for pre-eclampsia in populations of low nutritional status from developing countries

OBJECTIVE

To determine if vitamin C and E supplementation in high-risk pregnant women with low nutritional status reduces pre-eclampsia.

DESIGN

Multicentred, randomised, controlled, double-blinded trial.

SETTING

Antenatal care clinics and Hospitals in four countries.

POPULATION

Pregnant women between 14 and 22 weeks' gestation.

METHOD

Randomised women received 1000 mg vitamin C and 400 iu of vitamin E or placebo daily until delivery.

MAIN OUTCOME MEASURES

Pre-eclampsia, low birthweight, small for gestational age and perinatal death.

RESULTS

Six hundred and eighty-seven women were randomised to the vitamin group and 678 to the placebo group. Groups had similar gestational ages (18.1; SD 2.4 weeks), socio-economic, clinical and demographical characteristics and blood pressure at trial entry. Risk factors for eligibility were similar, except for multiple pregnancies: placebo group (14.7%), vitamins group (11.8%). Previous pre-eclampsia, or its complications, was the most common risk factor at entry (vitamins 41.6%, placebo 41.3%). Treatment compliance was 87% in the two groups and loss to follow-up was low (vitamins 2.0%, placebo 1.3%). Supplementation was not associated with a reduction of pre-eclampsia (RR: 1.0; 95% CI: 0.9-1.3), eclampsia (RR: 1.5; 95% CI: 0.3-8.9), gestational hypertension (RR: 1.2; 95% CI: 0.9-1.7), nor any other maternal outcome. Low birthweight (RR: 0.9; 95% CI: 0.8-1.1), small for gestational age (RR: 0.9; 95% CI: 0.8-1.1) and perinatal deaths (RR: 0.8; 95% CI: 0.6-1.2) were also unaffected.

CONCLUSION

Vitamins C and E at the doses used did not prevent pre-eclampsia in these high-risk women.

Folic acid supplementation in early second trimester and the risk of preeclampsia

OBJECTIVE

The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia.

STUDY DESIGN

We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks' gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis.

RESULTS

A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 micromol/L), decreased plasma homocysteine (on average 0.39 micromol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75).

CONCLUSION

Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.

Validity of preeclampsia-related diagnoses recorded in a national hospital registry and in a postpartum interview of the women

In a population-based sample, the authors examined the validity of preeclampsia and related diagnoses recorded in a mandatory Danish national hospital discharge registry and in a standardized telephone interview of women who gave birth between 1998 and 2002. Using a "gold standard" for preeclampsia defined in accordance with the guidelines from the American College of Obstetricians and Gynecologists, the authors reviewed hospital charts of 3,039 women and found that 61 of 88 preeclampsia cases (69.3%) and 24 of 55 cases of serious subtypes of preeclampsia (43.6%) were recorded as such by the registry. A total of 21 of 2,951 women without preeclampsia (0.71%) had a preeclampsia diagnosis in the registry. All registrations of serious subtypes of preeclampsia reflected true cases. The positive predictive value of a preeclampsia diagnosis in the registry was 74.4%. Including interview data reduced the sample size to 2,307 women. In this sample, of 62 women with preeclampsia, 45 (72.6%) reported in the interview to have had preeclampsia. Of 2,245 women with no preeclampsia, 31 (1.4%) reported to have had preeclampsia. The positive predictive value of the women's own report on preeclampsia was 59.2%. The authors conclude, for the purpose of etiologic studies, that the registry had acceptable validity, whereas the usefulness of self-reported information may be limited.

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.

Is vitamin E a safe prophylaxis for preeclampsia?

The prophylactic use of vitamins E and C for the prevention of preeclampsia is currently being evaluated in multiple clinical trials in Canada, Mexico, the United Kingdom, the United States, and other developing countries. In addition to its antioxidant capacity, exogenous vitamin E may prevent an immunologic switch (Th1 to Th2) that is vital for early-to late transition in normal pregnancies. Moreover, vitamin E could be a potential interferon-gamma (IFN-gamma) mimic facilitating persistent proinflammatory reactions at the fetal-maternal interface. These untoward effects of dietary intake of vitamin E may be more pronounced in those treated cases that fail to develop preeclampsia. A critical test of this hypothesis would be to establish whether, under variable O2 tension, vitamin E is capable of affecting cytokine signaling in placental trophoblasts and maternal immune effector cells, both in early and late human pregnancies.

Mechanisms of Disease: pre-eclampsia

Pre-eclampsia, a syndrome of pregnant women, is one of the leading causes of maternal and fetal morbidity and mortality. Despite active research, the etiology of this disorder remains an enigma. Recent work has, however, provided promising explanations for the causation of the disorder and some of its phenotypes. Evidence indicates that the symptoms of hypertension and proteinuria, upon which the diagnosis of pre-eclampsia is based, have several underlying causes. Nevertheless, the treatment of pre-eclampsia has not changed significantly in over 50 years. This review describes the most recent insights into the pathophysiology of pre-eclampsia from both basic and clinical research, and attempts to provide a unifying hypothesis to reconcile the abnormalities at the feto-placental level and the clinical features of the maternal syndrome. The novel findings outlined in this review provide a rationale for potential future prophylactic and therapeutic interventions for pre-eclampsia.

Tyrosine Phosphorylation of Caveolin 1 by Oxidative Stress Is Reversible and Dependent on the c-src Tyrosine Kinase but Not Mitogen-Activated Protein Kinase Pathways in Placental Artery Endothelial Cells1

Acute H(2)O(2) exposure to placental artery endothelial cells induced an array of tyrosine-phosphorylated proteins, including caveolin 1 (CAV1) rapid and transient tyr(14) phosphorylated in a time- and concentration-dependent manner. Basal tyr(14) phosphorylated CAV1 was primarily located at the edges of cells and associated with actin filaments. Phosphorylated CAV1 was markedly increased and diffused with the disorganization of actin filaments at 20 min, disappeared at 120 min treatment with 0.2 mM H(2)O(2). Treatment with H(2)O(2) also disorganized actin filaments and changed cell shape in a time-dependent manner. Pretreatment with antioxidants catalase completely, whereas the other tested superoxide dismutase, N-acetyl-l-cysteine and sodium formate partially attenuated H(2)O(2)-induced CAV1 phosphorylation in a concentration-dependent manner. Acute treatment with H(2)O(2) activated multiple signaling pathways, including the mitogen-activated protein kinases (MAPK) members (MAPK3/1-ERK2/1, MAPK8/9-JNK1/2, and MAPK11-p38(mapk)) and the c-src tyrosine kinase (CSK). Pharmacological studies demonstrated that, among these pathways, only the blockade of CSK activation abolished H(2)O(2)-induced CAV1 phosphorylation. Additionally, H(2)O(2)-induced CAV1 phosphorylation was reversible rapidly (<10 min) upon H(2)O(2) withdrawal. Because maternal and fetal endothelia must make dynamic adaptations to oxidative stress resulting from enhanced pregnancy-specific oxygen metabolism favoring prooxidant production, which is emerging as one of the leading causes of the dysfunctional activated endothelium during pregnancy, these unique features of CAV1 phosphorylation on oxidative stress observed implicate an important role of CAV1 in placental endothelial cell biology during pregnancy.