Pathogenesis and promising non-invasive markers for preeclampsia

Hypoxic modulation of fetal vascular MLCK abundance, localization, and function

Changes in vascular contractility are among the most important physiological effects of acute and chronic fetal hypoxia. Given the essential role of myosin light-chain kinase (MLCK) in smooth muscle contractility and its heterogeneous distribution, this study explores the hypothesis that subcellular changes in MLCK distribution contribute to hypoxic modulation of fetal carotid artery contractility. Relative to common carotid arteries from normoxic term fetal lambs (FN), carotids from fetal lambs gestated at high altitude (3,802 m) (FH) exhibited depressed contractility without changes in MLCK mRNA or protein abundance. Patterns of confocal colocalization of MLCK with α-actin and 20-kDa regulatory myosin light chain (MLC20) enabled calculation of subcellular MLCK fractions: 1) colocalized with the contractile apparatus, 2) colocalized with α-actin distant from the contractile apparatus, and 3) not colocalized with α-actin. Chronic hypoxia did not affect MLCK abundance in the contractile fraction, despite a concurrent decrease in contractility. Organ culture for 72 h under 1% O2 decreased total MLCK abundance in FN and FH carotid arteries, but decreased the contractile MLCK abundance only in FH carotid arteries. Correspondingly, culture under 1% O2 depressed contractility more in FH than FN carotid arteries. In addition, hypoxia appeared to attenuate ubiquitin-independent proteasomal degradation of MLCK, as reported for other proteins. In aggregate, these results demonstrate that the combination of chronic hypoxia followed by hypoxic culture can induce MLCK translocation among at least three subcellular fractions with possible influences on contractility, indicating that changes in MLCK distribution are a significant component of fetal vascular responses to hypoxia.

Involvement of Receptor for Advanced Glycation Endproducts in Hypertensive Disorders of Pregnancy

Preeclampsia/hypertensive disorders of pregnancy (PE/HDP) is a serious and potentially life-threatening disease. Recently, PE/HDP has been considered to cause adipose tissue inflammation, but the detailed mechanism remains unknown. We exposed human primary cultured adipocytes with serum from PE/HDP and healthy controls for 24 h, and analyzed mRNA expression of several adipokines, cytokines, and ligands of the receptor for advanced glycation endproducts (RAGE). We found that the mRNA levels of interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), high mobility group box 1 (HMGB1), and RAGE were significantly increased by the addition of PE/HDP serum. Among RAGE ligands, advanced glycation endproducts (AGE) and HMGB1 increased mRNA levels of IL-6 and CCL2 in SW872 human adipocytes and mouse 3T3-L1 cells. The introduction of small interfering RNA for RAGE (siRAGE) into SW872 cells abolished the AGE- and HMGB1-induced up-regulation of IL-6 and CCL2. In addition, lipopolysaccharide (LPS), a ligand of RAGE, increased the expression of IL-6 and CCL2 and siRAGE attenuated the LPS-induced expression of IL-6 and CCL2. These results strongly suggest that the elevated AGE, HMGB1, and LPS in pregnant women up-regulate the expression of IL-6 and CCL2 via the RAGE system, leading to systemic inflammation such as PE/HDP.

Syndecan 4, galectin 2, and death receptor 3 (DR3) as novel proteins in pathophysiology of preeclampsia

INTRODUCTION

Preeclampsia has the highest rate of obstetric morbidity and mortality.

METHODS

We recruited 21 women with preeclampsia and 27 women with uncomplicated pregnancies. We used a quantitative protein macroarray that allowed for analysis of 40 proteins.

RESULTS

We found a statistically significant increase in the concentration of DR3, LIF and a significant decrease of VEGF, PlGF, syndecan-4 and galectin-2, in the plasma of women with preeclampsia.

CONCLUSIONS

There are no previous studies assessing syndecan 4, galectin 2, and DR3 concentrations in women with preeclampsia; Our results indicate these proteins are new factors that play important roles in the immunological pathomechanism of preeclampsia.

Angiogenic factor screening in women with mild preeclampsia - New and significant proteins in plasma

INTRODUCTION

The aim of this study was to analyse a panel of 60 angiogenic factors (pro-angiogenic and antiangiogenic) in the plasma of women with mild preeclampsia.

MATERIALS AND METHODS

We recruited 21 women between 25 and 40 weeks gestation with diagnosed mild preeclampsia into the study group and 27 healthy women with uncomplicated pregnancies of corresponding gestational age to that of the study to the control group. We used a quantitative protein macroarray method that allowed for analysis of 60 angiogenic proteins per sample simultaneously.

RESULTS

We showed a statistically significant increase in the concentration of 8 proteins, interferon gamma (IFN-γ), interleukin 6 (IL-6), leukaemia inhibitory factor (LIF), heparin-binding EGF-like growth factor (HB-EGF), hepatocyte growth factor (HGF), C-X-C motif chemokine 10 (IP-10), leptin and platelet-derived growth factor BB (PDGF-BB), as well as a significant decrease in the concentration of 3 proteins, vascular endothelial growth factor (VEGF), placental growth factor (PlGF) and follistatin, in the plasma of women with preeclampsia.

CONCLUSION

Based on our findings, it seems that protein factors may play an important role in the pathogenesis of preeclampsia, and there are many proteins that have not been studied in PE to date. There are no previous studies assessing the LIF, follistatin, HGF, HB-EGF and PDGF-BB concentrations in the plasma of women with PE; therefore, our obtained results indicate that these proteins are new factors that can play an important role in the pathomechanisms of PE.

Sphingolipids as a new factor in the pathomechanism of preeclampsia - Mass spectrometry analysis

Objective(s) and design

The aim of the study was to analyse a panel of 11 sphingolipids in plasma and three blood fractions (platelet-poor plasma, platelets and red blood cells) of women with mild preeclampsia.

Materials and methods

We recruited 21 women between 25–40 weeks gestation with diagnosed mild preeclampsia to the study group and 36 healthy women with uncomplicated pregnancies, who corresponded with the study group according to gestational age, to the control group. To assess the concentration of 11 sphingolipids in the blood plasma and blood fractions, we used ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/MS/MS).

Results

We showed a significant increase in the concentration of eight sphingolipids in the plasma of women with preeclampsia in comparison to the control group: Sph (p = 0.0032), S1P (p = 0.0289), C20-Cer (p < 0.0001), C18-Cer (p < 0.0001), C16-Cer (p = 0.012), C18:1-Cer (p = 0.003), C22-Cer (p = 0.0071), and C24:1-Cer (p = 0.0085).

Conclusion

We showed that selected sphingolipids, especially C20-Cer and C18-Cer, are totally new factors in the pathomechanism of PE and that these bioactive lipids may play an important role in apoptosis and autophagy.

Synthetic Receptors Induce Anti Angiogenic and Stress Signaling on Human First Trimester Cytotrophoblast Cells

The cytotrophoblast (CTB) cells of the human placenta have membrane receptors that bind certain cardiotonic steroids (CTS) found in blood plasma. One of these, marinobufagenin, is a key factor in the etiology of preeclampsia. Herein, we used synthetic receptors (SR) to study their effectiveness on the angiogenic profile of human first trimester CTB cells. The humanextravillous CTB cells (Sw.71) used in this study were derived from first trimester chorionic villus tissue. Culture media of CTB cells treated with ≥1 nM SR level revealed sFlt-1 (Soluble fms-like tyrosine kinase-1) was significantly increased while VEGF (vascular endothelial growth factor) was significantly decreased in the culture media (* p < 0.05 for each) The AT₂ receptor (Angiotensin II receptor type 2) expression was significantly upregulated in ≥1 nM SR-treated CTB cells as compared to basal; however, the AT₁ (Angiotensin II receptor, type 1) and VEGFR-1 (vascular endothelial growth factor receptor 1) receptor expression was significantly downregulated (* p < 0.05 for each). Our results show that the anti-proliferative and anti-angiogenic effects of SR on CTB cells are similar to the effects of CTS. The observed anti angiogenic activity of SR on CTB cells demonstrates that the functionalized-urea/thiourea molecules may be useful as potent inhibitors to prevent CTS-induced impairment of CTB cells.

Transthyretin regulates the migration and invasion of JEG-3 cells

Preeclampsia (PE) is a pregnancy-specific disorder characterized by new-onset hypertension and proteinuria that occurs after 20 weeks of gestation. It involves several organs and continues to be a leading cause of maternal and perinatal morbidity and mortality worldwide. Shallow trophoblast invasion is a common pathological feature of PE. Transthyretin (TTR) is a 56-kDa homotetrameric protein that binds thyroid hormone and retinol binding protein. Dysregulated TTR expression has been found in cases of PE. The aim of the present study was to determine the functional role of TTR in the migration and invasion of JEG-3 choriocarcinoma cells. JEG-3 cells were transfected with a plasmid construct expressing TTR (pCMV-Myc-TTR) or an empty plasmid (pCMV-Myc). Cell migration and invasion capacities were assessed by Transwell migration and invasion assays, respectively. These experiments demonstrated that TTR overexpression significantly increased the migration and invasion potential of JEG-3 cells. Matrix metalloproteinases (MMPs) are a family of zinc-containing endopeptidases capable of degrading a wide range of extracellular matrix components. Western blot analysis revealed that TTR overexpression resulted in significantly increased levels of MMP2 and MMP9 in JEG-3 cells. In conclusion, our findings suggest an important role for TTR in regulating trophoblast invasion and migration, representing a possible underlying pathological and molecular mechanisms of PE.

Risk of Preeclampsia in Pregnancies After Assisted Reproductive Technology and Ovarian Stimulation

Objective To compare the risk of preeclampsia among spontaneously conceived pregnancies to those after hyperestrogenic ovarian stimulation (hyperestrogenic OS) with and without assisted reproductive technology (ART), and stimulation with non-hyperestrogenic aromatase inhibitor stimulation (non-hyperestrogenic OS). Methods Live-born singleton deliveries among women 20-49 years were identified in the 2004-2012 Truven Health MarketScan Commercial Claims and Encounters Databases using ICD-9 and CPT codes. Maternal characteristics were compared using Chi squared and Fisher exact tests. We performed multilevel multivariable logistic regression, controlling for maternal age, parity, comorbid conditions, and region of delivery, and calculated adjusted odds ratios (aOR) and 95 % confidence intervals for mild and severe preeclampsia. Results 1,014,526 spontaneously conceived, 6881 hyperestrogenic OS with ART, 27,516 hyperestrogenic OS without ART, and 2117 non-hyperestrogenic OS pregnancies were identified. The adjusted odds of developing preeclampsia were increased for deliveries after hyperestrogenic OS with ART (mild preeclampsia aOR 1.42, 1.24-1.62; severe preeclampsia aOR 1.83, 1.59-2.11) and without ART (mild preeclampsia aOR 1.32, 1.24-1.42; severe preeclampsia aOR 1.53, 1.41-1.66). Adjusted odds of preeclampsia were similar between spontaneously conceived and non-hyperestrogenic OS pregnancies. Conclusions for Practice Risk of preeclampsia after ART may in part be related to supraphysiologic estrogen associated with hyperestrogenic OS.

Aortic Fibrosis, Induced by High Salt Intake in the Absence of Hypertensive Response, is Reduced by a Monoclonal Antibody to Marinobufagenin

BACKGROUND

Marinobufagenin (MBG) is an endogenous Na/K-ATPase inhibitor, a natriuretic and a vasoconstrictor. MBG is implicated in salt-sensitive hypertension, cardiac hypertrophy, and initiate the pro-fibrotic signaling. Previously it was demonstrated that immunoneutralization of an endogenous MBG by 3E9 anti-MBG-antibody (mAb) in vivo lowered blood pressure (BP) and reversed cardiac fibrosis in salt-sensitive, and in partially nephrectomized rats. In the present study, we investigated whether mAb alleviates vascular remodeling induced in normotensive rats on high salt intake.

METHODS

Wistar rats (5 months old) received normal (CTRL; n = 8) or high salt intake (2% NaCl in drinking water) for 4 weeks ( n = 16). Rats from the group on a high salt intake were administered vehicle (SALT; n = 8) or mAb (50 µg/kg) (SALT-AB; n = 8) during the last week of high salt diet. BP, erythrocyte Na/K-ATPase activity, levels of MBG in plasma and 24-hour urine, and sensitivity of aortic explants to the vasorelaxant effect of sodium nitroprusside (SNP) were measured. Aortic collagen abundance was determined immunohistochemically.

RESULTS

In SALT vs. CTRL, heightened levels of MBG were associated with inhibition of erythrocyte Na/K-ATPase in the absence of BP changes. High salt intake was accompanied by a 2.5-fold increase in aortic collagen abundance and by a reduction of sensitivity of aortic explants to the vasorelaxant effect of SNP following endothelin-1-induced constriction. In the SALT-AB group, all NaCl-mediated effects were reversed by immunoneutralization of MBG.

CONCLUSIONS

High salt intake in young normotensive rats can induce vascular fibrosis via pressure-independent/MBG-dependent mechanisms, and this remodeling is reduced by immunoneutralization of MBG.

Involvement of Visceral Adipose Tissue in Immunological Modulation of Inflammatory Cascade in Preeclampsia

Objectives. The pathophysiology of preeclampsia is characterized by abnormal placentation, an exaggerated inflammatory response, and generalized dysfunction of the maternal endothelium. We investigated the effects of preeclampsia serum on the expression of inflammation-related genes by adipose tissue. Materials and Methods. Visceral adipose tissue was obtained from the omentum of patients with early ovarian cancer without metastasis. Adipose tissue was incubated with sera obtained from either five women affected with severe preeclampsia or five women from control pregnant women at 37°C in a humidified incubator at 5% CO₂ for 24 hours. 370 genes in total mRNA were analyzed with quantitative RT-PCR (Inflammatory Response & Autoimmunity gene set). Results. Gene expression analysis revealed changes in the expression levels of 30 genes in adipose tissue treated with preeclampsia sera. Some genes are related to immune response, oxidative stress, insulin resistance, and adipogenesis, which plays a central role in excessive systemic inflammatory response of preeclampsia. In contrast, other genes have shown beneficial effects in the regulation of Th2 predominance, antioxidative stress, and insulin sensitivity. Conclusion. In conclusion, visceral adipose tissue offers protection against inflammation, oxidative insults, and other forms of cellular stress that are central to the pathogenesis of preeclampsia.

Introduction of a nomogram for predicting adverse pregnancy outcomes based on maternal serum markers in the quad screen test

PURPOSE

The aim of this study was to develop a nomogram that can calculate a total score, derived from each serum marker in the quad screen test, for systematically predicting adverse pregnancy outcomes (APOs).

METHODS

We retrospectively reviewed 3684 singleton pregnant women who underwent a quad screen test and gave birth at a single medical centre from January 2005 to December 2010. The serum marker data from the quad screen test and pregnancy outcomes were used to construct logistic regression models for predicting the risks of APOs. APO was defined as the presence of at least one of the following: preeclampsia, preterm delivery before 34 weeks of gestation, small for gestational age, foetal loss, and foetal demise. A graphic nomogram was generated to represent the scoring model using the regression coefficient of each serum marker.

RESULTS

A nomogram for the prediction of APOs using each serum marker in the quad test was developed based on the logistic regression analysis. The positive predictive values for the subsequent development of an APO were ascended stepwise as the calculated score increases. The area under the receiver operating characteristic curve of this score for the prediction of APO was 0.596 (95 % confidence interval 0.569-0.623).

CONCLUSIONS

We here introduced a nomogram for stratifying the risk of APOs in patients with abnormal serum markers in the quad screen test. Although the validity of the nomogram is too weak to be used in clinical routine, but it may provide additional information for practitioners counselling pregnant women and for predicting APOs.

Preeclampsia and maternal cardiovascular disease: consequence or predisposition?

Formerly preeclamptic women stand a higher chance of developing cardiovascular disease (CVD) later in life and may experience a shortened life span. This review updates the pathophysiology and definition of this complex disease and highlights the protective role of pregnancy by considering the relationship between pregnancy interval and likelihood of disease recurrence. The evidence for persistent maternal cardiovascular impairment following preeclampsia (PE) is considered, e.g. postpartum changes in CVD occurrence, blood pressure elevation and changes in the renin-angiotensin-aldosterone system). Since maternal endothelial dysfunction is a hallmark of PE, we summarize the evidence for reduced flow-mediated dilation in women with previous PE, and consider the utility and shortcomings of this clinical measure. In addition to viewing postpartum changes as a consequence of this disease, we consider the alternative view that PE might be the manifestation of a maternal phenotype that already has some predisposition to or is in the earlier stages of CVD; in this case, some of the postpartum residual deficits (or their antecedents) may have already been present prior to pregnancy. Finally, we consider the use of novel biomarkers for predicting or detecting PE prior to the appearance of clinical symptoms.

The possible involvement of microRNAs in preeclampsia and gestational diabetes mellitus

Great obstetrical syndromes is a collective name for several complications of pregnancy that affect >15% of pregnancies. They may confer adverse pregnancy outcomes and maternal and fetal morbidity, and require close medical monitoring and treatment. The etiology, pathogenesis, and outcome of these syndromes are obscure in the majority of cases. All appear during mid-to-late pregnancy with no reliable biomarkers for early detection and possibly prevention at present. This article focuses on the quest for early reliable markers for preeclampsia and gestational diabetes mellitus (GDM) development, mainly on the involvement of microRNA in the pathogenesis and its possible role as an early biomarker for disease development.

Association between hypoxia and perinatal arterial ischemic stroke: a meta-analysis

BACKGROUND

Perinatal arterial ischemic stroke (AIS) occurs in an estimated 17 to 93 per 100000 live births, yet the etiology is poorly understood. Although investigators have implicated hypoxia as a potential cause of AIS, the role of hypoxia in AIS remains controversial. The aim of this study was to estimate the association between perinatal hypoxia factors and perinatal arterial ischemic stroke through a meta-analysis of published observational studies.

PATIENTS AND METHODS

A systematic search of electronically available studies published through July 2013 was conducted. Publication bias and heterogeneity across studies were evaluated and summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with fixed-effects or random-effects models.

RESULTS

A total of 8 studies describing the association between perinatal hypoxia factors and neonatal arterial ischemic stroke (AIS) met inclusion criteria, and 550 newborns with AIS were enrolled. The associations were found for AIS: preeclampsia (OR 2.14; 95% CI, 1.25 to 3.66), ventouse delivery (OR 2.23; 95% CI, 1.26 to 3.97), fetal heart rate abnormalities (OR 6.30; 95% CI, 3.84 to 10.34), reduced fetal movement (OR 5.35; 95% CI, 2.17 to 13.23), meconium-stained liquor (OR 3.05; 95% CI, 2.02 to 4.60), low Apgar score (OR 5.77; 95% CI, 1.66 to 20.04) and resuscitation at birth (OR 4.59; 95% CI, 3.23 to 6.52). Our data did not show any significant change of the mean risk estimate for oxytocin induction (OR 1.33; 95% CI, 0.84 to 2.11) and low arterial umbilical cord ph (OR 4.63; 95% CI 2.14 to 9.98).

CONCLUSIONS

There is a significant association between perinatal hypoxia factors and AIS. The result indicates that perinatal hypoxia maybe one of causes of AIS. Large scale prospective clinical studies are still warranted.