Sleep Quality in Individuals with and without Persistent Postpartum Hypertension

OBJECTIVE

 This study aimed to compare sleep quality at 1 year postpartum following a hypertensive disorder of pregnancy (HDP) among individuals with persistent postpartum hypertension (HTN) compared with those with normal blood pressures (BPs).

STUDY DESIGN

 We combined data from the Heart Health 4 New Moms pilot randomized trial (n = 118) and the Pathways prospective cohort study (n = 36). Individuals with a singleton pregnancy complicated by gestational HTN or preeclampsia underwent a research study visit at a mean 48.7 ± 9.5 weeks postpartum with standardized BP measurement and assessment of subjective sleep quality with the Pittsburgh Sleep Quality Index (PSQI). Persistent postpartum HTN was defined as Stage 1 HTN or greater (mean systolic BP ≥ 130 mm Hg or mean diastolic BP ≥ 80 mm Hg over three measurements at rest) or requiring antihypertensive medication. Statistical analysis was performed using univariate and multivariable logistic regression analyses.

RESULTS

 Of 154 individuals with an HDP included in the analysis, 84 (55%) were normotensive at 1 year postpartum and 70 (45%) had persistent postpartum HTN. Individuals with persistent postpartum HTN were more likely to be older, self-identify as Black race, have higher prepregnancy and 1-year postpartum body mass index (BMI), be multiparous, and deliver at an earlier gestational age. The mean global PSQI score was 8.7 ± 3.7, with 81% reporting poor sleep (PSQI > 5), and scores were higher among individuals who were persistently hypertensive (9.6 ± 3.5) compared with those who were normotensive at 1 year postpartum (7.9 ± 3.6), p < 0.01. Findings were unchanged in a multivariable model adjusting for age, self-reported race, prepregnancy BMI, and parity.

CONCLUSION

 Following an HDP, individuals reported poor sleep quality at 1 year postpartum. Individuals with persistent postpartum HTN reported lower sleep quality, suggesting that sleep behavior may be a target for intervention to improve maternal cardiovascular health following an HDP.

KEY POINTS

· After an HDP, poor sleep quality was common at 1 year postpartum.. · Those with persistent postpartum HTN reported worse sleep quality at 1 year postpartum.. · Sleep behavior may be a target for intervention to improve maternal cardiovascular health..

Inflammatory markers are elevated in early pregnancy, but not late pregnancy, in women with overweight and obesity that later develop preeclampsia

PROBLEM

Obesity and preeclampsia both involve a pathological inflammatory response, which may be how obesity increases preeclampsia risk. Previous studies have failed to assess robust measurements of inflammatory markers across gestation, specifically in overweight/ obese women in the context of preeclampsia.

METHOD OF STUDY

We measured 20 inflammatory markers in plasma via multiplex assay (ThermoFisher Inflammation 20 plex Human ProcartaPlex Panel) across the three trimesters of pregnancy in an existing cohort of overweight and obese women who developed preeclampsia (n = 37) and without preeclampsia (n = 74). Mann-Whitney U tests examined differences in inflammatory marker concentrations between cases and controls. Repeated measures ANOVA tests were used to explore differences in inflammatory marker concentrations over time within cases and controls.

RESULTS

Pro-inflammatory markers (IL-1α, IL-1β, IL-6, IFN-α, IFN-γ, GM-CSF, IL-12p70, IL-17α, TNF-α, IL-8) and anti-inflammatory markers (IL-4, IL-10, IL-13) were higher in the first and second trimester in participants who later developed preeclampsia compared to those who did not (p < .05). Only TNF-α and IL-8 remained elevated in the third trimester. Inflammatory markers did not change across pregnancy in preeclampsia cases but did increase across pregnancy in controls.

CONCLUSION

Our findings diverge from prior studies, predominantly of non-obese women, that report lower circulating concentrations of anti-inflammatory cytokines in preeclampsia versus normotensive pregnancy, particularly by late pregnancy. We posit that women with overweight and obesity who develop preeclampsia entered pregnancy with a heightened pro-inflammatory state likely related to obesity, which increased risk for preeclampsia. Further studies are needed to investigate if inflammatory maker profiles differ between obese and non-obese women.

A longitudinal epigenome-wide association study of preeclamptic and normotensive pregnancy

Background

While preeclampsia (PE) is a leading cause of pregnancy-related morbidity/mortality, its underlying mechanisms are not fully understood. DNA methylation (DNAm) is a dynamic regulator of gene expression that may offer insight into PE pathophysiology and/or serve as a biomarker (e.g., risk, subtype, a therapeutic response). This study's purpose was to evaluate for differences in blood-based DNAm across all trimesters between individuals eventually diagnosed with PE (cases) and individuals who remained normotensive throughout pregnancy, did not develop proteinuria, and birthed a normally grown infant (controls).

Results

In the discovery phase, longitudinal, genome-wide DNAm data were generated across three trimesters of pregnancy in 56 participants (n=28 cases, n=28 controls) individually matched on self-identified race, pre-pregnancy body mass index, smoking, and gestational age at sample collection. An epigenome-wide association study (EWAS) was conducted, using surrogate variable analysis to account for unwanted sources of variation. No CpGs met the genome-wide significance p value threshold of 9×10-8, but 16 CpGs (trimester 1: 5; trimester 2: 1; trimester 3: 10) met the suggestive significance threshold of 1×10-5. DNAm data were also evaluated for differentially methylated regions (DMRs) by PE status. Three DMRs in each trimester were significant after Bonferonni-adjustment. Since only third-trimester samples were available from an independent replication sample (n=64 cases, n=50 controls), the top suggestive hits from trimester 3 (cg16155413 and cg21882990 associated with TRAF3IP2-AS1/TRAF3IP2 genes, which also made up the top DMR) were carried forward for replication. During replication, DNAm data were also generated for validation purposes from discovery phase third trimester samples. While significant associations between DNAm and PE status were observed at both sites in the validation sample, no associations between DNAm and PE status were observed in the independent replication sample.

Conclusions

The discovery phase findings for cg16155413/cg21882990 (TRAF3IP2-AS1/TRAF3IP2) were validated with a new platform but were not replicated in an independent sample. Given the differences in participant characteristics between the discovery and replication samples, we cannot rule out important signals for these CpGs. Additional research is warranted for cg16155413/cg21882990, as well as top hits in trimesters 1-2 and significant DMRs that were not examined in the replication phase.

Maternal Vascular Lesions in the Placenta Predict Vascular Impairments a Decade After Delivery

Women with adverse pregnancy outcomes later experience excess hypertension and cardiovascular disease, but how the events are linked is unknown. Examination of the placenta may provide clues to vascular impairments after delivery. Maternal vascular malperfusion lesions (MVMs) were abstracted from clinical reports, validated and characterized using clinical guidelines and severity score. A total of 492 women (170 with MVMs and 322 without MVMs) participated in a study visit 8 to 10 years after delivery to assess blood pressure, cardiometabolic factors, and sublingual microvascular features using sidestream dark field imaging. Covariates included age, race, adverse pregnancy outcomes (preeclampsia, small for gestational age, and preterm birth), and health behaviors. Women with versus without MVM had a distinct sublingual microvascular profile comprised of (1) lower microvascular density (-410 μm/mm², P=0.015), (2) higher red blood cell filling as a marker of perfusion (2%, P=0.004), and (3) smaller perfused boundary region (-0.07 µm, P=0.025) as a measure of glycocalyx integrity, adjusted for covariates including adverse pregnancy outcomes. Women with MVM also had higher adjusted diastolic blood pressure (+2.6 mm Hg, P=0.021), total and LDL (low-density lipoprotein)-cholesterol (+11.2 mg/dL, P=0.016; +8.7 mg/dL, P=0.031). MVM associations with subsequent cardiovascular measures did not vary by type of adverse pregnancy outcome, except among women with preterm births where blood pressure was higher only among those with MVM. Results were similar when evaluated as MVM severity. A decade after delivery, women with placental vascular lesions had an adverse cardiovascular profile comprised of microvascular rarefaction, higher blood pressure and more atherogenic lipids. Placental histopathology may reveal a woman's early trajectory toward subsequent vascular disease.

An exploratory study of white blood cell proportions across preeclamptic and normotensive pregnancy by self-identified race in individuals with overweight or obesity

Objective: Examine white blood cell (WBC) proportions across preeclamptic (n = 28 cases) and normotensive (n = 28 controls) pregnancy in individuals with overweight/obesity.Methods: WBC proportions were inferred from genome-wide DNA methylation data and compared by case/control status and self-identified race.Results: In Trimester 1, ean B cell proportions were suggestively lower in cases in the overall sample and significantly lower in White participants but not in Black participants. More significant WBC proportion changes were observed across normotensive than preeclamptic pregnancy.Conclusions: These findings in a small sample demonstrate need for additional studies investigating the relationship between self-identified race and WBCs in pregnancy.

An Exploratory Study of Epigenetic Age in Preeclamptic and Normotensive Pregnancy Reveals Differences by Self-Reported Race but Not Pregnancy Outcome

Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality. Chronological age and race are associated with preeclampsia, but the role of these factors is not entirely understood. We hypothesized that DNA methylation age, a measure of biological age, would be higher in individuals with preeclampsia than in individuals with normotensive pregnancy and that DNA methylation age would differ by race across pregnancy. This was a longitudinal, exploratory study of 56 pregnant individuals (n = 28 preeclampsia cases and n = 28 normotensive controls). Genome-wide DNA methylation data were generated from trimester-specific peripheral blood samples. DNA methylation age was estimated using the "Improved Precision" clock, and ∆age, the difference between DNA methylation age and chronological age, was computed. DNA methylation age was compared with chronological age using Pearson correlations. The relationships between ∆age and preeclampsia status, self-reported race, and covariates were tested using multiple linear regression and performed both with and without consideration of cell-type heterogeneity. We observed strong correlation between chronological age and DNA methylation age across pregnancy, with significantly stronger correlation observed in White participants than in Black participants. We observed no association between ∆age and preeclampsia status. However, ∆age was higher in participants with higher pre-pregnancy body mass index in trimester 1 and lower in Black participants than in White participants in trimesters 2 and 3. Observations were largely consistent when controlling for cell-type heterogeneity. Our findings in a small sample support the need for additional studies to investigate the relationship between race and biological age, which could provide further insight into racial disparities across pregnancy. However, this study does not support an association between ∆age and preeclampsia status.

Go Red for Women Strategically Focused Research Network: Summary of Findings and Network Outcomes

The Go Red for Women movement was initiated by the American Heart Association (AHA) in the early 2000s to raise awareness concerning cardiovascular disease (CVD) risk in women. In 2016, the AHA funded 5 research centers across the United States to advance our knowledge of the risks and presentation of CVD that are specific to women. This report highlights the findings of the centers, showing how insufficient sleep, sedentariness, and pregnancy-related complications may increase CVD risk in women, as well as presentation and factors associated with myocardial infarction with nonobstructive coronary arteries and heart failure with preserved ejection fraction in women. These projects were augmented by collaborative ancillary studies assessing the relationships between various lifestyle behaviors, including nightly fasting duration, mindfulness, and behavioral and anthropometric risk factors and CVD risk, as well as metabolomic profiling of heart failure with preserved ejection fraction in women. The Go Red for Women Strategically Focused Research Network enhanced the evidence base related to heart disease in women, promoting awareness of the female-specific factors that influence CVD.

DNA Methylation of Endoglin Pathway Genes in Pregnant Women With and Without Preeclampsia

Objective

We compared blood-based DNA methylation levels of endoglin (ENG) and transforming growth factor beta receptor 2 (TGFβR2) gene promoter regions between women with clinically-overt preeclampsia and women with uncomplicated, normotensive pregnancies.

Methods

We used EpiTect Methyl II PCR Assays to evaluate DNA methylation of CpG islands located in promoter regions of ENG (CpG Island 114642) and TGFβR2 (CpG Island 110111). Preeclampsia was diagnosed based on blood pressure, protein, and uric acid criteria. N = 21 nulliparous preeclampsia case participants were 1:1 frequency matched to N = 21 nulliparous normotensive control participants on gestational age at sample collection (±2 weeks), smoking status, and labor status at sample collection. Methylation values were compared between case and control participant groups [(ENG subset: n = 20 (9 cases, 11 controls); TGFβR2 subset: n = 28 (15 cases, 13 controls)].

Results

The majority of the preeclampsia cases delivered at ⩾34 weeks' gestation (83%). Average methylation levels for ENG ([M ± (SD)]; Case Participant Group = 6.54% ± 4.57 versus Control Participant group = 4.81% ± 5.08; P = .102) and TGFβR2 (Case Participant Group = 1.50% ± 1.37 vs Control Participant Group = 1.70% ± 1.40; P = .695) promoter CpG islands did not differ significantly between the participant groups. Removal of 2 extreme outliers in the ENG analytic subset revealed a trend between levels of ENG methylation and pregnancy outcome (Case Participant Group = 5.17% ± 2.16 vs Control Participant Group = 3.36% ± 1.73; P = .062).

Conclusion

Additional epigenetic studies that include larger sample sizes, investigate preeclampsia subtypes, and capture methylation status of CpG island shores and shelves are needed to further inform us of the potential role that ENG and TGFβR2 DNA methylation plays in preeclampsia pathophysiology.

Abstract 3: Preeclampsia-induced T Helper-associated Cytokine Imbalances Persist Postpartum

Preeclampsia (PreE), a hypertensive disorder in pregnancy, contributes to long-term maternal cardiovascular disease risk. By 2025, it is estimated that more women than men will have hypertension (HTN), yet the mechanisms contributing to the development of HTN in women are less understood. One potential mechanism underlying HTN in women is a persistent imbalance of anti- and pro- inflammatory T H cells following PreE. Consistent with this, anti-inflammatory T helper (T H ) cytokines are reduced and pro-inflammatory T H cytokines are increased during a PreE pregnancy.

De-identified and coded plasma samples and clinical data were obtained from the Magee-Women’s Research Institute & Foundation or the University of Iowa Maternal-Fetal Tissue Bank (IRB 201808705) from women 1-3 (N=93) or 8-10 (N=58) years (yrs) following a normotensive (CTL) or PreE-affected pregnancy. Postpartum (PP) HTN was defined as having stage 1 or higher HTN as designated in the updated 2017 ACC/AHA guidelines. Women with PreE had higher rates of HTN at 1-3 years and at 8-10 years PP, (24% vs. 5% and 65% vs. 17%, all p<0.05) compared to women with a normotensive pregnancy.

To determine if T H cells play a role in the future development of HTN, we investigated if the T H cytokine changes observed in PreE persist 1-3 yrs and 8-10 yrs PP. Cytokine concentrations were determined via ELISAs and normalized to total protein. Average cytokine concentrations are reported in pg/g. At 1-3 yrs PP, concentrations of anti-inflammatory cytokines IL-4 (47 vs. 6819, p<0.05), IL-10 (1204 vs. 15042, p<0.05) and TGFβ (8.2x10 5 vs. 4.4x10 6 , p<0.05) were reduced in women with a prior PreE pregnancy vs. women with a CTL pregnancy. At 8-10 yrs PP, pro-inflammatory IL-6 (86 vs. 18, p<0.05) and TNFα (298 vs. 53, p<0.05) were both significantly increased in women with prior PreE compared to women with a CTL pregnancy.

Here, we confirm women with a prior PreE pregnancy present with a higher prevalence of HTN early (1-3 yrs) and later (8-10 yrs) PP compared to women with a normotensive pregnancy. Further, we show an altered T H cytokine milieu persists following delivery in women with PreE. This pro-inflammatory milieu is associated with increased rates of HTN and thus, may underlie the future development of HTN in women with a history of PreE.

Life Course Changes in Cardiometabolic Risk Factors Associated With Preterm Delivery: The 30-Year CARDIA Study

Background

Women who deliver preterm infants (<37 weeks) have excess cardiovascular risk; however, it is unclear whether the unfavorable changes in the cardiometabolic profile associated with preterm delivery initiate before, during, or after childbearing.

Methods and Results

We identified 1306 women (51% Black) with births between baseline (1985–1986) and year 30 in the CARDIA (Coronary Artery Risk Development in Young Adults) study. We compared life course changes in blood pressure, body mass index, waist circumference, and lipids in women with preterm deliveries (n=318) with those with all term deliveries (n=988), using piecewise linear mixed‐effects models. Specifically, we evaluated group differences in rates of change before and after the childbearing period and change in level across the childbearing period. After adjusting for the covariates, women with preterm deliveries had a higher change in diastolic blood pressure across the childbearing period than those with all term deliveries (1.59 versus −0.73 mm Hg, P<0.01); the rates of change did not differ by group, both prechildbearing and postchildbearing. Women with preterm deliveries had a larger body mass index increase across the childbearing period (1.66 versus 1.22 kg/m², P=0.03) compared with those with all term deliveries, followed by a steeper increase after the childbearing period (0.22 versus 0.17 kg/m² per year, P=0.02).

Conclusions

Preterm delivery was associated with unfavorable patterns of change in diastolic blood pressure and adiposity that originate during the childbearing years and persist or exacerbate later in life. These adverse changes may contribute to the elevated cardiovascular risk among women with preterm delivery.

Noninvasive sublingual microvascular imaging reveals sex-specific reduction in glycocalyx barrier properties in patients with coronary artery disease

BACKGROUND

Risk factors for coronary artery disease (CAD) have been associated with endothelial dysfunction and degradation of the endothelial glycocalyx. This study was designed to compare sublingual microvascular perfusion and glycocalyx barrier properties in CAD patients and controls using noninvasive side stream darkfield imaging.

METHODS

Imaging of the sublingual microvasculature was performed in 52 case subjects (CAD confirmed by left heart catheterization) and 63 controls (low Framingham risk score). Red blood cell (RBC) filling percentage and functional microvascular density, measures of microvascular perfusion, and perfused boundary region (PBR), an index of glycocalyx barrier function, were measured in microvessels with a diameter ranging from 5-25 µm.

RESULTS

RBC filling percentage was lower in patients with CAD compared to controls (p < .001). Functional microvascular density did not differ between groups. The overall PBR was marginally greater in the CAD group compared to the control group (p = .08). PBR did not differ between male CAD cases and controls (p = .17). However, PBR was greater in females with CAD compared with female controls (p = .04), indicating reduced glycocalyx barrier function. This difference became more pronounced after adjusting for potential confounders.

CONCLUSIONS

Our data suggest that patients with CAD are characterized by a reduction in percentage of time microvessels are occupied by RBCs. In addition, CAD is significantly associated with impaired sublingual microvascular glycocalyx barrier function in women but not men. More research is needed to determine the significance of peripheral microvascular dysfunction in the pathophysiology of CAD, and how this may differ by sex.

Role of vitamin D in cell-cell interaction of fetal endothelial progenitor cells and umbilical cord endothelial cells in a preeclampsia-like model

Maternal endothelial dysfunction is a cental feature of preeclampsia (PE), a hypertensive disorder of pregnancy. Factors in the maternal circulation are thought to contribute to this endothelial dysfunction. Although understudied, factors in the fetal circulation may influence fetal endothelial cell interactions with endothelial progenitor cells as critical steps in placental angiogenesis. We hypothesize that cell-cell interactions that are important for pregnancy health are impaired by fetal serum from PE pregnancies and that 1,25(OH)₂-vitamin D₃ attenuates the negative effects of this serum on cell function. We tested the ability of fetal cord blood-derived endothelial progenitor cells [endothelial colony-forming cells (ECFCs)] to invade into established monolayers and capillary tubule-like structures of human fetal umbilical venous endothelial cells (HUVECs), while in the presence/absence of fetal cord serum from uncomplicated or PE pregnancies, and tested the ability of 1,25(OH)₂-vitamin D₃ to modulate the serum-mediated effects. PE cord serum reduced the invasion of fetal ECFCs into HUVEC monolayers or tubule networks. Vitamin D attenuated these effects of PE fetal serum on endothelial functional properties. Immunocytochemical studies revealed involvement of VE-cadherin contacts in interactions between ECFCs and mature fetal endothelial cells. PE cord serum reduces the ability of fetal endothelial progenitor cells to incorporate into fetal endothelial cell networks. Physiologic concentrations of vitamin D reverse these PE serum-mediated effects. These data appear consistent with lines of evidence that vitamin D has antipreeclampsia effects.

Preeclampsia-Associated Alteration of DNA Methylation in Fetal Endothelial Progenitor Cells

Objective

The pregnancy complication preeclampsia represents an independent risk factor for cardiovascular disease. Our previous research shows a diminished function of fetal endothelial colony-forming cells (ECFC), a proliferative subgroup of endothelial progenitor cells (EPC) in preeclampsia. The aim of this study was to further investigate whether DNA methylation of fetal EPC is affected in preeclampsia.

Methods

The genomic methylation pattern of fetal ECFC from uncomplicated and preeclamptic pregnancies was compared for 865918 CpG sites, and genes were classified into gene networks. Low and advanced cell culture passages were compared to explore whether expansion of fetal ECFC in cell culture leads to changes in global methylation status and if methylation characteristics in preeclampsia are maintained with increasing passage.

Results

A differential methylation pattern of fetal ECFC from preeclampsia compared to uncomplicated pregnancy was detected for a total of 1266 CpG sites in passage 3, and for 2362 sites in passage 5. Key features of primary networks implicated by methylation differences included cell metabolism, cell cycle and transcription and, more specifically, genes involved in cell-cell interaction and Wnt signaling. We identified an overlap between differentially regulated pathways in preeclampsia and cardiovascular system development and function. Cell culture passages 3 and 5 showed similar gene network profiles, and 1260 out of 1266 preeclampsia-associated methylation changes detected in passage 3 were confirmed in passage 5.

Conclusion

Methylation modification caused by preeclampsia is stable and detectable even in higher cell culture passages. An epigenetically modified endothelial precursor may influence both normal morphogenesis and postnatal vascular repair capacity. Further studies on epigenetic modifications in complicated pregnancies are needed to facilitate development of EPC based therapies for cardiovascular alterations.

Plasma concentrations of soluble endoglin in the maternal circulation are associated with maternal vascular malperfusion lesions in the placenta of women with preeclampsia

We evaluated the association between plasma soluble endoglin (sENG) and maternal vascular malperfusion (MVM) lesions of the placenta in women with preeclampsia. We measured sENG (sCD105) by ELISA in N = 70 women diagnosed with preeclampsia (median [IQR] GA at sampling = 36.4 [6.0] weeks) and available placental pathology. Placental pathology reports were reviewed for evidence of MVM based on the presence of ≥1 of the following: villous infarct, decidual vasculopathy, accelerated villous maturation, intervillous fibrin deposition, and/or low placental weight (<10th percentile for GA). We categorized plasma sENG concentrations into tertiles and used a modified Poisson regression approach to estimate the prevalence of MVM associated with sENG. We separately estimated the association between sENG and accelerated villous maturation, villous infarct, and low placental weight, the three most frequent lesions in the sample. We adjusted all models for age, parity, pre-pregnancy obesity, smoking, and infant sex. The prevalence of MVM in our sample of women with preeclampsia was 74%. Women in the highest sENG tertile had a higher prevalence of MVM (aPR[adjusted prevalence ratio] 1.70, 95% CI 1.15-2.52), low placental weight (aPR 3.26, 95% CI 1.25-8.50), and villous infarcts (aPR 2.93, 95% CI 1.27-6.73) compared with women in the lowest sENG tertile, after adjusting for covariates. Medium (aPR 2.57, 95% CI 1.17-5.66) and high (aPR 3.14, 95% CI 1.47-6.70) tertile concentrations of sENG were associated with higher accelerated villous maturation. Our results suggest that sENG may mark a more severe placental phenotype of preeclampsia, although findings should be replicated in larger cohorts.

Risk of hypertension and abnormal biomarkers in the first year postpartum associated with hypertensive disorders of pregnancy among overweight and obese women

OBJECTIVES

Hypertension and obesity are common cardiometabolic risk factors in reproductive age women. The association of hypertensive disorders of pregnancy with later-life cardiovascular disease is well-established, however, it is unknown how obesity and hypertensive disorders of pregnancy converge to accelerate development of hypertension in the postpartum period. The aim of this study was to characterize rates of sustained hypertension at one year postpartum using the new American Heart Association/American College of Cardiology Guidelines among overweight and obese women with a normotensive pregnancy or hypertensive disorder of pregnancy.

STUDY DESIGN

315 early pregnant women were enrolled prospectively and followed up to 12 months after delivery (mean 7.0 ± 1.8 months). At a postpartum research visit, we measured blood pressure and collected blood samples to measure cystatin C and high sensitivity C-reactive protein.

RESULTS

A total of 254 women had a normotensive pregnancy, 39 had gestational hypertension (12.4%) and 22 had preeclampsia (7.0%). 91 women had hypertension at the postpartum study visit (28.9%). After adjustment for maternal age, BMI, lactation and time postpartum, preeclampsia was associated with an aOR 2.35 (95%CI 1.63-3.41) of development of sustained hypertension and an aOR 3.23 (95%CI 1.56-6.68) of hypertension with abnormal biomarkers compared to women with normotensive pregnancies.

CONCLUSIONS

We demonstrate a high prevalence of hypertension and abnormal biomarkers associated with hypertensive disorders of pregnancy among overweight and obese women. Our findings support the need for structured follow up and risk reduction in overweight and obese women with hypertensive disorders of pregnancy as early as the first year postpartum.

Adverse pregnancy outcomes and future maternal cardiovascular disease

Cardiovascular disease (CVD) remains the leading cause of death in women. Although traditional risk factors increase later-life CVD, pregnancy-associated complications additionally influence future CVD risk in women. Recent guidelines for the prevention of CVD in women have added adverse pregnancy outcomes as major CVD risk factors. Studies have shown that women with a history of preeclampsia, gestational diabetes, preterm delivery, and delivery of a small-for-gestational-age infant have an increased risk of developing cardiometabolic risk factors and subsequent CVD. A history of multiple adverse pregnancy outcomes further increases this risk. It has been suggested that these pregnancy complications may unmask preexisting elevated CVD risk; however, whether the pathophysiologic changes underlying these conditions directly result in long-term cardiovascular damage is unclear. The purpose of this review was to highlight the associations between adverse pregnancy outcomes and future CVD, and to emphasize the importance of considering pregnancy history in assessing a woman's CVD risk. Targeted efforts to initiate screening and risk-reduction strategies in women with prior history of pregnancy complications, particularly lifestyle modification, may help decrease the burden of CVD in women.

Low Soluble Syndecan-1 Precedes Preeclampsia

INTRODUCTION

Syndecan-1 (Sdc1; CD138) is a major transmembrane heparan sulfate proteoglycan expressed on the extracellular, luminal surface of epithelial cells and syncytiotrophoblast, thus comprising a major component of the glycocalyx of these cells. The "soluble" (shed) form of Sdc1 has paracrine and autocrine functions and is normally produced in a regulated fashion. We compared plasma soluble Sdc1 concentrations, in relation to placental Sdc1 expression, in uncomplicated (control) and preeclamptic pregnancies.

METHODS

We evaluated soluble Sdc1 across uncomplicated pregnancy, and between preeclamptic, gestational hypertensive and control patients at mid-pregnancy (20 weeks) and 3rd trimester by ELISA. Placental expression level of Sdc1 was compared between groups in relation to pre-delivery plasma soluble Sdc1. Participants were recruited from Magee-Womens Hospital.

RESULTS

In uncomplicated pregnancy, plasma soluble Sdc1 rose significantly in the 1st trimester, and reached an approximate 50-fold increase at term compared to post pregnancy levels. Soluble Sdc1 was lower at mid-pregnancy in women who later developed preeclampsia (P<0.05), but not gestational hypertension, compared to controls, and remained lower at late pregnancy in preeclampsia (P<0.01) compared to controls. Sdc1 was prominently expressed on syncytiotrophoblast of microvilli. Syncytiotrophoblast Sdc1 immunostaining intensities, and mRNA content in villous homogenates, were lower in preeclampsia vs. controls (P<0.05). Soluble Sdc1 and Sdc1 immunostaining scores were inversely associated with systolic blood pressures, and positively correlated with infant birth weight percentile.

CONCLUSION

Soluble Sdc1 is significantly lower before the clinical onset of preeclampsia, with reduced expression of Sdc1 in the delivered placenta, suggesting a role for glycocalyx disturbance in preeclampsia pathophysiology.

Evaluating the effects of preanalytical variables on the stability of the human plasma proteome

High quality clinical biospecimens are vital for biomarker discovery, verification, and validation. Variations in blood processing and handling can affect protein abundances and assay reliability. Using an untargeted LC-MS approach, we systematically measured the impact of preanalytical variables on the plasma proteome. Time prior to processing was the only variable that affected the plasma protein levels. LC-MS quantification showed that preprocessing times <6h had minimal effects on the immunodepleted plasma proteome, but by 4 days significant changes were apparent. Elevated levels of many proteins were observed, suggesting that in addition to proteolytic degradation during the preanalytical phase, changes in protein structure are also important considerations for protocols using antibody depletion. As to processing variables, a comparison of single- vs double-spun plasma showed minimal differences. After processing, the impact ⩽3 freeze-thaw cycles was negligible regardless of whether freshly collected samples were processed in short succession or the cycles occurred during 14-17 years of frozen storage (-80 °C). Thus, clinical workflows that necessitate modest delays in blood processing times or employ different centrifugation steps can yield valuable samples for biomarker discovery and verification studies.

Vitamin D rescues dysfunction of fetal endothelial colony forming cells from individuals with gestational diabetes

INTRODUCTION

Gestational diabetes (GDM) is associated with long-term cardiovascular and metabolic diseases in offspring. However, the mechanisms are not well understood. We explored whether fetal exposure to a diabetic environment is associated with fetal endothelial progenitor cell dysfunction, and whether vitamin D can reverse the impairment.

METHODS

Nineteen women with uncomplicated pregnancies and 18 women with GDM were recruited before delivery. Time to first appearance of endothelial colony forming cell (ECFC) colonies and number of ECFC colonies formed from culture of cord peripheral blood mononuclear cells were determined. Angiogenesis-related functions of ECFCs in vitro were tested in the presence or absence of vitamin D.

RESULTS

Fetal ECFCs from GDM pregnancies formed fewer colonies in culture (P = 0.04) and displayed reduced proliferation (P = 0.02), migration (P = 0.04) and tubule formation (P = 0.03) compared to uncomplicated pregnancies. Fetal ECFCs exposed to hyperglycemia in vitro exhibited less migration (P < 0.05) and less tubule formation (P < 0.05) than normoglycemic control. Vitamin D significantly improved the dysfunction of fetal ECFCs from pregnancies complicated by GDM or after exposure of healthy ECFCs to hyperglycemia.

DISCUSSION

Fetal ECFCs from GDM pregnancies or ECFCs exposed to hyperglycemia in vitro exhibit reduced quantity and impaired angiogenesis-related functions. Vitamin D significantly rescues these functions. These findings may have implications for vascular function of infants exposed to a diabetic intrauterine environment.

The -93T/G LPL Promoter Polymorphism Is Associated With Lower Third-Trimester Triglycerides in Pregnant African American Women

BACKGROUND

Hypertriglyceridemia is a risk factor for cardiovascular disease and several pregnancy complications. Lipoprotein lipase (LPL) genetic variation modulates nonpregnancy plasma triglycerides, but its effects during pregnancy are unknown. The G allele of the LPL -93T/G promoter polymorphism is 16-23 times more prevalent in Blacks than in Whites, contributing to lower triglycerides in nonpregnant African Americans by increasing LPL expression.

PURPOSE

This study investigated whether the triglyceride-lowering effect of -93G is observed in African Americans during pregnancy.

METHODS

Genotyping was performed on 124 African American women with uncomplicated pregnancies for common functional LPL polymorphisms/mutations (-93T/G, D9N, N291S, and S447X). Third-trimester plasma triglyceride, high- and low-density lipoprotein cholesterol, apolipoprotein B, and free fatty acid concentrations were measured with colorimetric assays. Clinical characteristics and lipid values were compared across the -93T/G genotypes.

RESULTS

Triglycerides were significantly lower in women with the -93GG compared to the -93TT genotype, both with (n = 124, p = .02) and without (n = 108, p = .03) inclusion of participants with other LPL variant alleles. Triglyceride differences persisted after adjustment for prepregnancy body mass index, gestational age at delivery, and smoking. There were no significant differences in the other lipids or apolipoprotein B by -93T/G genotype.

CONCLUSIONS

Despite the considerable metabolic changes accompanying pregnancy, the triglyceride-lowering effect associated with the -93GG LPL genotype in African Americans persists during late pregnancy. The -93GG genotype might protect against pregnancy complications stemming from hypertriglyceridemia, but the overall increased risk of pregnancy complications in African American women points to complex, multifactorial relationships among risk factors, race, and adverse pregnancy outcomes.

Vitamin D antagonizes negative effects of preeclampsia on fetal endothelial colony forming cell number and function

CONTEXT

Endothelial dysfunction is a primary feature of preeclampsia, a pregnancy complication associated with an increased future cardiovascular risk for mother and offspring. Endothelial colony forming cells (ECFC) are endothelial progenitor cells that participate in vasculogenesis and endothelial repair.

OBJECTIVE

We hypothesized that the number and functional properties of fetal cord blood-derived ECFCs are reduced in preeclampsia compared to uncomplicated pregnancy (controls), and asked if adverse effects of preeclampsia on ECFC function are reversed by 1,25 (OH)2 vitamin D3.

DESIGN, SETTING, PATIENTS

This was a nested, case-control study. Forty women with uncomplicated pregnancy and 33 women with PE were recruited at Magee-Womens Hospital (USA) or at Hannover Medical School (Germany).

MAIN OUTCOME MEASURES

Time to ECFC colony appearance in culture, and number of colonies formed, were determined. Functional abilities of ECFCs were assessed in vitro by tubule formation in Matrigel assay, migration, and proliferation. ECFC function was tested in the presence or absence of 1,25 (OH)2 vitamin D3, and after vitamin D receptor (VDR) or VEGF signaling blockade.

RESULTS

The number of cord ECFC colonies was lower (P = 0.04) in preeclampsia compared to controls. ECFCs from preeclampsia showed reduced proliferation (P<0.0001), formed fewer tubules (P = 0.02), and migrated less (P = 0.049) than control. Vitamin D3 significantly improved preeclampsia ECFC functional properties. VDR- or VEGF blockade reduced tubule formation, partially restorable by vitamin D3.

CONCLUSION

Fetal ECFCs from preeclamptic pregnancies are reduced in number and dysfunctional. Vitamin D3 had rescuing effects. This may have implications for the increased cardiovascular risk associated with preeclampsia.

Vitamin D prevents endothelial progenitor cell dysfunction induced by sera from women with preeclampsia or conditioned media from hypoxic placenta

CONTEXT

Placenta-derived circulating factors contribute to the maternal endothelial dysfunction underlying preeclampsia. Endothelial colony forming cells (ECFC), a sub-population of endothelial progenitor cells (EPCs), are thought to be involved in vasculogenesis and endothelial repair. Low vitamin D concentrations are associated with an increased risk for preeclampsia.

OBJECTIVE

We hypothesized that the function of human fetal ECFCs in culture would be suppressed by exposure to preeclampsia-related factors--preeclampsia serum or hypoxic placental conditioned medium--in a fashion reversed by vitamin D.

DESIGN, SETTING, PATIENTS

ECFCs were isolated from cord blood of uncomplicated pregnancies and expanded in culture. Uncomplicated pregnancy villous placenta in explant culture were exposed to either 2% (hypoxic), 8% (normoxic) or 21% (hyperoxic) O2 for 48 h, after which the conditioned media (CM) was collected.

OUTCOME MEASURES

ECFC tubule formation (Matrigel assay) and migration were examined in the presence of either maternal serum from preeclampsia cases or uncomplicated pregnancy controls, or pooled CM, in the presence or absence of 1,25(OH)2 vitamin D3.

RESULTS

1,25(OH)2 vitamin D3 reversed the adverse effects of preeclampsia serum or CM from hypoxic placenta on ECFCs capillary-tube formation and migration. Silencing of VDR expression by VDR siRNA, VDR blockade, or VEGF pathway blockade reduced ECFC functional abilities. Effects of VDR or VEGF blockade were partially prevented by vitamin D.

CONCLUSION

Vitamin D promotes the capillary-like tubule formation and migration of ECFCs in culture, minimizing the negative effects of exposure to preeclampsia-related factors. Further evaluation of the role of vitamin D in ECFC regulation and preeclampsia is warranted.

Nonesterified fatty acids and spontaneous preterm birth: a factor analysis for identification of risk patterns

We considered that accumulation of nonesterified (free) fatty acids (NEFAs) in the first trimester of pregnancy would mark women at excess risk of spontaneous preterm birth (sPTB) and examined the interplay between NEFAs, lipids, and other markers to explore pathways to sPTB. In a case-control study nested in the Pregnancy Exposures and Preeclampsia Prevention Study (Pittsburgh, Pennsylvania, 1997-2001), we assayed NEFA levels in nonfasting serum collected at a mean gestational week of 9.4 (range, 4-20 weeks) in 115 women with sPTB (<37 weeks) and 222 women with births occurring at ≥37 weeks. C-reactive protein, total cholesterol, low-density lipoprotein and high-density lipoprotein (HDL) cholesterol, triglycerides, and uric acid were also measured. Polytomous logistic regression models were used to evaluate tertiles of NEFA levels and sPTB at <34 weeks and 34-36 weeks; factor analysis was used to characterize patterns of biomarkers. Women with NEFA levels in the highest tertile versus the lowest were 2.02 (95% confidence interval: 1.13, 3.48) times more likely to have sPTB, after adjustment for covariates. Risk of sPTB before 34 weeks was particularly high among women with high NEFA levels (odds ratio = 3.73, 95% confidence interval: 1.33, 10.44). Six biomarker patterns were identified, and 2 were associated with sPTB: 1) increasing NEFA and HDL cholesterol levels and 2) family history of gestational hypertension. NEFA levels early in pregnancy were independently associated with sPTB, particularly before 34 weeks. We also detected a novel risk pattern suggesting that NEFAs together with HDL cholesterol may be related to sPTB.

Uterine vasculature remodeling in human pregnancy involves functional macrochimerism by endothelial colony forming cells of fetal origin

The potency of adult-derived circulating progenitor endothelial colony forming cells (ECFCs) is drastically surpassed by their fetal counterparts. Human pregnancy is associated with robust intensification of blood flow and vascular expansion in the uterus, crucial for placental perfusion and fetal supply. Here, we investigate whether fetal ECFCs transmigrate to maternal bloodstream and home to locations of maternal vasculogenesis, primarily the pregnant uterus. In the first instance, endothelial-like cells, originating from mouse fetuses expressing paternal eGFP, were identified within uterine endothelia. Subsequently, LacZ or enhanced green fluorescent protein (eGFP)-labeled human fetal ECFCs, transplanted into immunodeficient (NOD/SCID) fetuses on D15.5 pregnancy, showed similar integration into the mouse uterus by term. Mature endothelial controls (human umbilical vein endothelial cells), similarly introduced, were unequivocally absent. In humans, SRY was detected in 6 of 12 myometrial microvessels obtained from women delivering male babies. The copy number was calculated at 175 [IQR 149-471] fetal cells per millimeter square endothelium, constituting 12.5% of maternal vessel lumina. Cross-sections of similar human vessels, hybridized for Y-chromosome, positively identified endothelial-associated fetal cells. It appears that through ECFC donation, fetuses assist maternal uterine vascular expansion in pregnancy, potentiating placental perfusion and consequently their own fetal supply. In addition to fetal growth, this cellular mechanism holds implications for materno-fetal immune interactions and long-term maternal vascular health.

Vascular pool of releasable soluble VEGF receptor-1 (sFLT1) in women with previous preeclampsia and uncomplicated pregnancy

CONTEXT

Research examining the source of excess soluble fms-like tyrosine kinase 1 (sFLT1) in preeclampsia has focused on the placenta. The potential contribution of the releasable store of sFLT1 in the systemic vasculature is unknown.

OBJECTIVE

We asked whether the nonplacental releasable store of sFLT1 is larger in women with previous preeclampsia than in women with a previous uncomplicated pregnancy.

DESIGN

We administered heparin to nulligravid women and to women with previous preeclampsia or a previous uncomplicated pregnancy. We compared post-heparin sFLT1 concentrations with those observed in uncomplicated pregnancy and preeclampsia.

SETTING

The study was performed at Magee-Womens Hospital.

PATIENTS

Participants included nulligravidas (n = 8), women 6-24 months postpartum (previous uncomplicated pregnancy, n = 16; previous preeclampsia, n = 15), and pregnant women (uncomplicated pregnancy, n = 30; preeclampsia, n = 25).

INTERVENTION

Nonpregnant women received an unfractionated heparin bolus.

MAIN OUTCOME MEASURES

Pre- and post-heparin plasma sFLT1, placental growth factor, and vascular endothelial growth factor were measured.

RESULTS

In nonpregnant women, heparin increased plasma sFLT1 by 250-fold (P < .01), increased placental growth factor by 7-fold (P < .01), and decreased free vascular endothelial growth factor (P < .01). These changes did not differ between nulligravidas, women with previous preeclampsia, and women with a previous uncomplicated pregnancy. Post-heparin sFLT1 in nonpregnant women was higher than sFLT1 in uncomplicated pregnancy, but lower than sFLT1 in preeclampsia. Baseline and post-heparin sFLT1 were positively correlated (r(2) = 0.19; P < .01). Heparin increased the concentration of the 100-kDa sFLT1 isoform. Adding heparin to whole blood or plasma did not increase sFLT1.

CONCLUSIONS

Nonpregnant women have a significant vascular store of releasable sFLT1. The size of this store does not differ between women with previous preeclampsia vs women with previous uncomplicated pregnancy.

Endothelial colony-forming cells derived from pregnancies complicated by intrauterine growth restriction are fewer and have reduced vasculogenic capacity

CONTEXT

Endothelial colony-forming cells (ECFCs) are the only putative endothelial progenitor cells capable of vasculogenesis, and their dysfunction may represent a risk factor for cardiovascular disease. Intrauterine growth restriction (IUGR) is a pregnancy-related disorder associated with long-term cardiovascular risk.

OBJECTIVE

Our objective was to determine whether ECFCs derived from pregnancies complicated by IUGR exhibit altered vasculogenic potential.

DESIGN AND SETTING

This was a prospective cohort study; patients were recruited at St. Mary's Hospital, Manchester, United Kingdom.

PARTICIPANTS

Twenty-three women with normal pregnancies and 13 women with IUGR-complicated pregnancies at gestational ages above 37 weeks were included.

MAIN OUTCOME MEASURES

Vasculogenic capacity of rigorously characterized ECFCs was investigated in vivo by measuring blood vessel formation in collagen/fibronectin gels implanted in mice; proliferative, migratory, and chemotactic abilities were assessed in cell culture. Placental uptake of fetal ECFCs, assessed by differences in arterial and venous cord blood content, was determined by flow cytometry.

RESULTS

In vivo, IUGR ECFCs formed fewer blood vessels (P < .001) and capillaries (P = .001) compared with normal pregnancy-derived ECFCs. In culture conditions, IUGR ECFCs had reduced proliferation (P = .01) and migration (P = .007) and diminished chemotactic abilities to stromal cell-derived factor 1 (P = .007) coupled with reduced hypoxia-induced matrix metalloproteinase-2 release (P = .02). Finally, in IUGR pregnancies, the number of ECFCs was lower in arterial cord blood (P = .002) and placental uptake of cells was reduced (P < .001).

CONCLUSIONS

ECFCs derived from IUGR cord blood are rarefied and dysfunctional, resulting in diminished vasculogenic potential; this could be a cause of placental dysfunction in IUGR, with long-term postnatal implications for cardiovascular function in offspring.

Increased oxidized low-density lipoprotein causes blood-brain barrier disruption in early-onset preeclampsia through LOX-1

Early-onset preeclampsia (EPE) is a severe form of preeclampsia that involves life-threatening neurological complications. However, the underlying mechanism by which EPE affects the maternal brain is not known. We hypothesized that plasma from women with EPE increases blood-brain barrier (BBB) permeability vs. plasma from women with late-onset preeclampsia (LPE) or normal pregnancy (NP) and investigated its underlying mechanism by perfusing cerebral veins from nonpregnant rats (n=6-7/group) with human plasma from women with EPE, LPE, or NP and measuring permeability. We show that plasma from women with EPE significantly increased BBB permeability vs. plasma from women with LPE or NP (P<0.001). BBB disruption in response to EPE plasma was due to a 260% increase of circulating oxidized LDL (oxLDL) binding to its receptor, LOX-1, and subsequent generation of peroxynitrite (P<0.001). A rat model with pathologically high lipid levels in pregnancy showed symptoms of preeclampsia, including elevated blood pressure, growth-restricted fetuses, and LOX-1-dependent BBB disruption, similar to EPE (P<0.05). Thus, we have identified LOX-1 activation by oxLDL and subsequent peroxynitrite generation as a novel mechanism by which disruption of the BBB occurs in EPE. As increased BBB permeability is a primary means by which seizure and other neurological symptoms ensue, our findings highlight oxLDL, LOX-1, and peroxynitrite as important therapeutic targets in EPE.

Cytochrome P450 subfamily 2J polypeptide 2 expression and circulating epoxyeicosatrienoic metabolites in preeclampsia

BACKGROUND

Preeclampsia is a multisystem disorder of pregnancy, originating in the placenta. Cytochrome P450 (CYP)-dependent eicosanoids regulate vascular function, inflammation, and angiogenesis, which are mechanistically important in preeclampsia.

METHODS AND RESULTS

We performed microarray screening of placenta and decidua (maternal placenta) from 25 preeclamptic women and 23 control subjects. The CYP subfamily 2J polypeptide 2 (CYP2J2) was upregulated in preeclamptic placenta and decidua. Reverse-transcription polymerase chain reaction confirmed the upregulation, and immunohistochemistry localized CYP2J2 in trophoblastic villi and deciduas at 12 weeks and term. The CYP2J2 metabolites, 5,6-epoxyeicosatrienoic acid (EET), 14,15-EET, and the corresponding dihydroxyeicosatrienoic acids, were elevated in preeclamptic women compared with controls in the latter two thirds of pregnancy and after delivery. Stimulating a trophoblast-derived cell line with the preeclampsia-associated cytokine tumor necrosis factor-α enhanced CYP2J2 gene and protein expression. In 2 independent rat models of preeclampsia, reduced uterine-perfusion rat and the transgenic angiotensin II rat, we observed elevated EET, dihydroxyeicosatrienoic acid, and preeclamptic features that were ameliorated by the CYP epoxygenase inhibitor N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide (MsPPOH). Uterine arterial rings of these rats also dilated in response to MsPPOH. Furthermore, 5,6-EET could be metabolized to a thromboxane analog. In a bioassay, 5,6-EET increased the beating rate of neonatal cardiomyocytes. Blocking thromboxane synthesis reversed that finding and also normalized large-conductance calcium-activated potassium channel activity.

CONCLUSIONS

Our data implicate CYP2J2 in the pathogenesis of preeclampsia and as a potential candidate for the disturbed uteroplacental remodeling, leading to hypertension and endothelial dysfunction.

Vitamin D improves the angiogenic properties of endothelial progenitor cells

The main pathogenic feature of preeclampsia is maternal endothelial dysfunction that results from impaired angiogenesis and reduced endothelial repair capacity. In addition, preeclampsia risk is associated with vitamin D deficiency. We hypothesized that vitamin D(3) stimulates proangiogenic properties of endothelial colony-forming cells (ECFCs). ECFCs were obtained and cultured from cord blood and characterized by immunocytochemistry and flow cytometry. Proliferation, total length of tubule formation on Matrigel, expression of VEGF mRNA, and pro-matrix metalloproteinases (MMP)-2 activity were assessed after treatment of ECFCs with vitamin D(3). Specificity of the observed effects was tested by blocking the vitamin D receptor (VDR) or the VEGF signaling pathway. ECFCs treated with 10 nM vitamin D(3) showed a 1.27 times higher tubule formation compared with vehicle-treated controls (1.27 ± 0.19) as well as a 1.36 times higher proliferation rate (1.36 ± 0.06). Vitamin D(3) induced pro-MMP-2 activity (1.29 ± 0.17) and VEGF mRNA levels (1.74 ± 0.73) in ECFCs. VDR blocking by pyridoxal-5-phosphate (0.73 ± 0.19) or small interfering RNA (0.75 ± 0.17) and VEGF inhibition by Su5416 (0.56 ± 0.16) or soluble fms-like tyrosine kinase-1 (0.7 ± 0.14) reduced tubule formation and pro-MMP-2 activity (pyridoxal-5-phosphate: 0.84 ± 0.09; Su5416: 0.79 ± 0.11; or sFlt: 0.88 ± 0.13). This effect was neutralized by vitamin D(3). Consequently, vitamin D(3) significantly promoted angiogenesis in ECFCs in vitro possibly due to an increase in VEGF expression and pro-MMP-2 activity. Since angiogenesis is a crucial feature in the pathophysiology of preeclampsia these findings could explain the positive influence of vitamin D(3) in reducing preeclampsia risk.

PP085. Angiotensin II type 1 receptor antibodies increase angiotensin II sensitivity in pregnant rats

INTRODUCTION

Pregnant women who subsequently develop preeclampsia are highly sensitive to infused angiotensin (Ang) II; the sensitivity persists postpartum. Activating autoantibodies against the Ang II type 1 (AT1) receptor are present in preeclampsia. In vitro and in vivo data suggest that they could be involved in the disease process.

OBJECTIVES

The aim of the study was to show if AT1-AB generated by immunisation alters Ang II sensitivity in pregnant rats.

METHODS

We generated and purified activating antibodies against the AT1 receptor (AT1-AB) by immunizing rabbits against the AFHYESQ epitope of the second extracellular loop, which is the binding epitope of endogenous activating autoantibodies against AT1 from patients with preeclampsia. We then purified AT1-AB using affinity chromatography with the AFHYESQ peptide.

RESULTS

We were able to detect AT1-AB both by ELISA and a functional bioassay. We then passively transferred AT1-AB into pregnant rats, alone or combined with Ang II. AT1-AB activated protein kinase C-alpha and extracellular-related kinase 1/2. Passive transfer of AT1-AB alone or Ang II (435ng/kg per minute) infused alone did not induce a preeclampsia-like syndrome in pregnant rats. However, the combination (AT1-AB plus Ang II) induced hypertension, proteinuria, intrauterine growth retardation, and arteriolosclerosis in the uteroplacental unit. We next performed gene-array profiling of the uteroplacental unit and found that hypoxia-inducible factor 1alpha was upregulated by Ang II plus AT1-AB, which we then confirmed by Western blotting in villous explants. Furthermore, endothelin 1 was upregulated in endothelial cells by Ang II plus AT1-AB. We show that AT1-AB induces Ang II sensitivity.

CONCLUSION

Our mechanistic study supports the existence of an "autoimmune-activating receptor" that could contribute to Ang II sensitivity and possibly to preeclampsia.

OS063. Vitamin D promotes endothelial progenitor cell differentiationand upregulates VEGF

INTRODUCTION

Preeclampsia is multifactorial in origin but the primary trigger is thought to be related to impaired placentation which is followed by systemic maternal responses. Vitamin D3 deficiency is a worldwide problem and is associated with a substantial increase in preeclampsia risk. Endothelial progenitor cells, in particular their highly proliferative subpopulation of endothelial colony forming cells (ECFC), play an important role in placental vasculogenesis and endothelial repair capacity. However, the mechanisms of vitamin D3 influence on placental development are poorly understood.

OBJECTIVES

Therefore we investigated the influence of vitamin D3 on the differentiation of endothelial progenitor cells (ECFCs) in a placental angiogenesis model and hypothesized that vitamin D3 stimulates the expression of vascular endothelial growth factor (VEGF) in ECFCs.

METHODS

Umbilical cord blood was obtained from uncomplicated, term pregnancies, the mononuclear cells were isolated and seeded onto collagen-coated culture plates for outgrowth of ECFCs. After preincubation with 10 nM vitamin D3, ECFCs were plated onto Matrigel (BD Biosciences) in the presence of the treatment media. After 6 hours capillary-like tubules were fixed and their total length was determined per well and median values were calculated from n=38 experiments. For mRNA expression analyses total RNA isolation was performed. High capacity cDNA reverse transcription kit (Invitrogen) was used for cDNA synthesis and Real time RT-PCR was performed on the Rotor Gene 6000 PCR instrument (Corbett Research) using VEGF-A primers according to existing literature. Statistical analysis was performed using Wilcoxon signed rank test.

RESULTS

Our experiments show a significant promoting effect of vitamin D3 on tubule formation in ECFCs. ECFCs treated with 10nM vitamin D3 showed a 1.27 times higher tubule formation compared to vehicle-treated controls (1.27±0.19, p<0.05, n=38). mRNA expression analysis showed a 1.8 times higher expression of VEGF-A mRNA in ECFCs treated with 10nM vitamin D3 compared to controls (1.82±0.43, p<0.0001, n=18).

CONCLUSION

Physiological concentrations of vitamin D3 significantly promote the formation of capillary-like structures by ECFCs in a cell culture model. This effect is mediated by an up-regulation of VEGF-mRNA in ECFCs by Vitamin D3. Since the de novo angiogenesis is a crucial step in development of the placenta, a vitamin D deficiency could play an important role in the pathophysiology of preeclampsia. This finding goes along with clinical studies in which vitamin D deficiency increases the risk of preeclampsia substantially.

Low placental growth factor across pregnancy identifies a subset of women with preterm preeclampsia: type 1 versus type 2 preeclampsia?

Preeclampsia is a heterogeneous syndrome affecting 3% to 5% of all pregnancies. An imbalance of the antiangiogenic and proangiogenic factors, soluble receptor fms-like tyrosine kinase 1 and placental growth factor (PGF), is thought to contribute to the pathophysiology of preeclampsia. Maternal plasma PGF and soluble receptor fms-like tyrosine kinase 1 were quantified by specific immunoassays in cross-sectional samples from 130 preeclamptic subjects and 342 normotensive controls at delivery and longitudinally in samples from 50 women who developed preeclampsia and 250 normotensive controls. Among women who developed preeclampsia, 46% (n=23) evidenced a pattern of consistently low maternal PGF across pregnancy below the lower 95% CI of controls from 15 weeks' gestation to term. In contrast, the remaining 54% (n=27) of women who developed preeclampsia had maternal PGF concentrations similar to or above (n=7) those of normotensive controls. Subjects with low PGF across pregnancy who developed preeclampsia evidenced significantly higher blood pressure in early pregnancy (P<0.05) and, after diagnosis, earlier gestational age at delivery (P<0.05) and more preterm birth (P<0.05) compared with preeclamptic patients with high PGF. A significant subset of women who develop preeclampsia show evidence of consistently low PGF across pregnancy. Low PGF with preeclampsia was associated with preterm delivery compared with preeclamptic patients with high PGF. Identifying women with consistently low plasma PGF during pregnancy may provide a greater understanding of preeclampsia pathophysiology and may provide more focused research and clinical activities.

The expression profile of C19MC microRNAs in primary human trophoblast cells and exosomes

The largest gene cluster of human microRNAs (miRNAs), the chromosome 19 miRNA cluster (C19MC), is exclusively expressed in the placenta and in undifferentiated cells. The precise expression pattern and function of C19MC members are unknown. We sought to profile the relative expression of C19MC miRNAs in primary human trophoblast (PHT) cells and exosomes. Using high-throughput profiling, confirmed by PCR, we found that C19MC miRNAs are among the most abundant miRNAs in term human trophoblasts. Hypoxic stress selectively reduced miR-520c-3p expression at certain time-points with no effect on other C19MC miRNAs. Similarly, differentiation in vitro had a negligible effect on C19MC miRNAs. We found that C19MC miRNAs are the predominant miRNA species expressed in exosomes released from PHT, resembling the profile of trophoblastic cellular miRNA. Predictably, we detected the similar levels of circulating C19MC miRNAs in the serum of healthy pregnant women at term and in women with pregnancies complicated by fetal growth restriction. Our data define the relative expression levels of C19MC miRNAs in trophoblasts and exosomes, and suggest that C19MC miRNAs function in placental-maternal signaling.

Transcriptionally active syncytial aggregates in the maternal circulation may contribute to circulating soluble fms-like tyrosine kinase 1 in preeclampsia

The cardinal manifestations of the pregnancy-specific disorder preeclampsia, new-onset hypertension, and proteinuria that resolve with placental delivery have been linked to an extracellular protein made by the placenta, soluble fms-like tyrosine kinase 1 (sFlt1), that injures the maternal vasculature. However, the mechanisms by which sFlt1, which is heavily matrix bound, gain access to the systemic circulation remain unclear. Here we report that the preeclamptic placenta's outermost layer, the syncytiotrophoblast, forms abundant "knots" that are enriched with sFlt1 protein. These syncytial knots easily detach from the syncytiotrophoblast, resulting in free, multinucleated aggregates (50-150 μm diameter) that are loaded with sFlt1 protein and mRNA, are metabolically active, and are capable of de novo gene transcription and translation. At least 25% of the measurable sFlt1 in the third-trimester maternal plasma is bound to circulating placental microparticles. We conclude that detachment of syncytial knots from the placenta results in free, transcriptionally active syncytial aggregates that represent an autonomous source of sFlt1 delivery into the maternal circulation. The process of syncytial knot formation, shedding of syncytial aggregates, and appearance of placental microparticles in the maternal circulation appears to be greatly accelerated in preeclampsia and may contribute to the maternal vascular injury that characterizes this disorder.

Angiotensin II type 1 receptor antibodies and increased angiotensin II sensitivity in pregnant rats

Pregnant women who subsequently develop preeclampsia are highly sensitive to infused angiotensin (Ang) II; the sensitivity persists postpartum. Activating autoantibodies against the Ang II type 1 (AT(1)) receptor are present in preeclampsia. In vitro and in vivo data suggest that they could be involved in the disease process. We generated and purified activating antibodies against the AT(1) receptor (AT(1)-AB) by immunizing rabbits against the AFHYESQ epitope of the second extracellular loop, which is the binding epitope of endogenous activating autoantibodies against AT(1) from patients with preeclampsia. We then purified AT(1)-AB using affinity chromatography with the AFHYESQ peptide. We were able to detect AT(1)-AB both by ELISA and a functional bioassay. We then passively transferred AT(1)-AB into pregnant rats, alone or combined with Ang II. AT(1)-AB activated protein kinase C-α and extracellular-related kinase 1/2. Passive transfer of AT(1)-AB alone or Ang II (435 ng/kg per minute) infused alone did not induce a preeclampsia-like syndrome in pregnant rats. However, the combination (AT(1)-AB plus Ang II) induced hypertension, proteinuria, intrauterine growth retardation, and arteriolosclerosis in the uteroplacental unit. We next performed gene-array profiling of the uteroplacental unit and found that hypoxia-inducible factor 1α was upregulated by Ang II plus AT(1)-AB, which we then confirmed by Western blotting in villous explants. Furthermore, endothelin 1 was upregulated in endothelial cells by Ang II plus AT(1)-AB. We show that AT(1)-AB induces Ang II sensitivity. Our mechanistic study supports the existence of an "autoimmune-activating receptor" that could contribute to Ang II sensitivity and possible to preeclampsia.

Maternal gene expression profiling during pregnancy and preeclampsia in human peripheral blood mononuclear cells

Preeclampsia is a major obstetrical complication affecting maternal and fetal health. While it is clear that there is a substantial placental contribution to preeclampsia pathogenesis, the maternal contribution is less well characterized. We therefore performed a genome-wide transcriptome analysis to explore disease-associated changes in maternal gene expression patterns in peripheral blood mononuclear cells (PBMCs).

METHODS

Preeclampsia was defined as gestational hypertension, proteinuria and hyperurecimia. Total RNA was isolated from PBMCs obtained from women with uncomplicated pregnancies (n = 5) and women with preeclamptic pregnancies (n = 5). Gene expression analysis was carried out using Agilent oligonucleotide microarrays. Biological pathway analysis was undertaken using Ingenuity Pathway Analysis software. Quantitative real-time PCR (QRTPCR) was performed to validate the gene expression changes of selected genes in normotensive and preeclamptic patients (n = 12 each).

RESULTS

We identified a total of 368 genes that were differentially expressed in women with preeclampsia compared to normal controls with false discovery rate (FDR) controlled at 10%. In follow up experiments we further analyzed the expression levels of a number of genes that were identified as altered by the microarray data including survivin (BIRC5), caveolin (CAV1), GATA binding protein-1 (GATA1), signal tranducer and activator of transcription 1 (STAT1), E2F transcription factor-1 (E2F1), fibronectin-1 (FN1), interleukin-4 (IL-4), matrix metalloprotease-9 (MMP-9) and WAP four disulfide domain protein (WFDC-1) by QRTPCR. Additionally we performed immuno blot analysis and zymography to verify some of these candidate genes at the protein level. Computational analysis of gene function identified an anti-proliferative and altered immune function cellular phenotype in severe preeclamptic samples.

CONCLUSIONS

We have characterized the genome-wide mRNA expression changes associated with preeclampsia-specific genes in circulating maternal blood cells at the time of delivery. In addition to providing information relating to the biological basis of the preeclampsia phenotype, our data provide a number of potential biomarkers for use in the further characterization of this disease.

The levels of hypoxia-regulated microRNAs in plasma of pregnant women with fetal growth restriction

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression at the post-transcriptional level. While mostly intracellular, a portion of cellular miRNAs is released to the circulation and their level in the plasma is altered in certain pathological conditions such as cancer, and also during pregnancy. We examined the circulating levels of a set of trophoblastic miRNAs, which we recently found to be regulated by hypoxia, in the plasma of pregnant women with fetal growth restriction (FGR). Pregnancy was associated with increased plasma levels of several placenta-specific miRNAs, compared to non-pregnant controls. Among pregnant women, the overall levels of miRNA species that we analyzed were increased by 1.84-fold (p < or = 0.01) in plasma of women with pregnancies complicated by FGR, but decreased in FGR placentas by 24% (p < or = 0.01) compared to values from uncomplicated pregnancies. Together, our results show that plasma concentration of miRNAs is regulated in pregnancy, and that FGR is associated with increased circulating miRNA levels, highlighting the need to explore plasma miRNAs as potential biomarkers for placental diseases.

Maternal circulating CD34+VEGFR-2+ and CD133+VEGFR-2+ progenitor cells increase during normal pregnancy but are reduced in women with preeclampsia

Circulating endothelial progenitor cells (EPCs) may contribute to vascular endothelial cell homeostasis, and low levels of these cells are predictive of cardiovascular disease. We hypothesized that circulating EPCs increase in number during uncomplicated pregnancy but are reduced in women with preeclampsia. Peripheral blood was obtained from pregnant women and from nulligravidas in cross-sectional design. Cells expressing CD34 or CD133, in combination with vascular endothelial growth factor receptor-2 (VEGFR-2), were enumerated by flow cytometry. Both CD34(+)VEGFR-2(+) (doubly positive) and CD133(+)VEGFR-2( +) cells were significantly increased during the second and third trimesters of uncomplicated pregnancy compared to the first trimester. First trimester and nulligravida groups did not differ. Endothelial progenitor cells, quantified by flow cytometry or by circulating angiogenic cell (CAC) culture assay, were significantly reduced in women with preeclampsia compared to third trimester controls. Circulating EPCs appear to increase during normal pregnancy, and comparatively reduced numbers of these cells exist during preeclampsia.

Endothelial progenitor cells: their potential in the placental vasculature and related complications

Endothelial progenitor cells (EPCs) have received significant attention in recent times. A role for EPCs has been suggested in a range of pathologies and some recent studies of EPCs in pregnancy have been published. This review provides a guide to the confusing field of EPCs. Attention is paid to their phenotyping, as although elementary this remains a highly debated topic. The current understanding of different subtypes and physiological role of EPCs in the placenta, fetus and adult are also considered. An overview is given as to role of EPC's in the pathophysiology of different disease states and the possible therapeutic and diagnostic applications expected from EPC-related research in obstetrics.