The placenta in preeclampsia

Efficacy of Magnesium Sulfate on Maternal Mortality in Eclampsia

Eclampsia is a common complication of preeclampsia patients and can be life-threatening for both the mother and the fetus. Hence, timely intervention and appropriate management of this detrimental condition are extremely crucial. Eclampsia is described as the occurrence of generalized convulsions in patients with preeclampsia. Magnesium sulfate (MgSO₄) is the drug of choice for treating and preventing eclampsia. This review aims to study and analyze the available literature on the pathogenesis of eclampsia, the pharmacology of MgSO₄, and its effectiveness in the management of eclampsia. Other proposed treatments and their comparative study with MgSO₄ are also discussed. Additionally, we examine the data regarding the impact of eclampsia, its public health burden, and the cost-effectiveness of MgSO₄. One of the major drawbacks associated with the use of MgSO₄ in low-income countries has been the cost of treatment and the lack of resources. We have analyzed the trials that have proposed alternate treatment regimens which could shape new guidelines to resolve these issues. For this review, we extensively studied abstract and full-text articles from multiple databases. This article discusses the pathophysiology of eclampsia, the pharmacology of MgSO₄, the issues surrounding eclampsia management, and how MgSO₄ benefits these patients.

Overexpression of let-7b exerts beneficial effects on the functions of human placental trophoblasts by activating the ERK1/2 signaling pathway

The present work aimed to explore let-7b's molecular mechanisms that regulate the functions of placental trophoblasts and to examine placental let-7b expression in human pre-eclampsia (PE). Human trophoblast HTR-8/SVneo cells underwent transduction with control and let-7b overexpressing lentiviruses, respectively. Cell proliferation assessment utilized cell counting kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays. Apoptosis, autophagy, inflammation, epithelial-to-mesenchymal transition (EMT), and ERK1/2 signaling-associated proteins were assessed by immunoblot. Placental tissue samples were collected from women with normal pregnancy (n = 20) and PE patients (n = 14). Let-7b overexpression in HTR-8/SVneo cells remarkably induced cell proliferation and invasion, suppressed apoptosis and autophagy, and resulted in decreased tumor necrosis factorα (TNF-α) expression and increased interleukin 6 (IL-6) expression in trophoblasts. Notably, the beneficial effects of let-7b overexpression, including cell invasion and EMT, were largely reversed by treatment with U0126, an indirect ERK1/2 signaling inhibitor, in these cells. TGF-β receptor type-1 (TGFBR1) overexpression weakened let-7b's functions in ERK pathway activation and invasion in trophoblasts. Placental tissue specimens from PE cases demonstrated significantly lower let-7b expression compared with normal controls. Overexpression of let-7b exerts beneficial effects on the functions of human placental trophoblasts via ERK1/2 signaling, and placental let-7b is downregulated in human PE. These findings suggest let-7b is a promising biomarker for the prospective diagnosis and targeted therapy of PE.

Placental apoptotic markers are associated with placental morphometry

INTRODUCTION

Preeclampsia is a hypertensive disorder affecting both mother and the fetus and is a major cause of maternal and neonatal morbidity and mortality. Abnormal placentation is a common feature in preeclampsia that contributes to placental dysfunction. It is likely that increased homocysteine and oxidative stress influence apoptosis in preeclampsia. Increased placental apoptosis may aggravate the symptoms of preeclampsia through disruption of the placental structure. The current study aims to examine the association between various placental apoptotic markers with placental dimensions and maternal and neonatal characteristics in women with preeclampsia.

METHODS

A total of 80 pregnant women [preeclampsia (n = 40); normotensive control (n = 40)] were included in the study. Placental characteristics such as its major axis, minor axis, breadth, thickness (at centre, cord insertion and periphery) and trimmed placental weight were recorded.Placental protein levels of caspase-3, caspase-8, BAX and Bcl-2 were estimated by ELISA and gene expression were examined by real time quantitative PCR.

RESULT

Protein levels of proapoptotic markers such as caspase-8 and 3 were higher (p < 0.01) in the preeclampsia group compared to control whereas, the level of antiapoptotic marker Bcl-2 (p < 0.05) was lower in the preeclampsia group. Caspase-3 and Bcl-2 protein levels were negatively associated with thickness of placenta at cord insertion (p < 0.01). Protein levels of caspase-8 and caspase-3 were positively associated with placental MDA levels (p < 0.01). Caspase-8 was negatively associated with baby length (p = 0.055).

DISCUSSION

This study demonstrates the association of various apoptotic markers with oxidative stress and placental dimensions.

Using ultrasound to define the time point of intrauterine growth retardation in a mouse model of heme oxygenase-1 deficiency†

The enzyme heme oxygenase-1 (HO-1), encoded by the HMOX1 gene, mediates heme catabolism by cleaving free heme. We have previously revealed the importance of HO-1 in pregnancy. Here, we determined the impact of maternal or paternal HO-1 deficiency on fetal growth and placental parameters throughout gestation. We mated Hmox1-sufficient (WT), partial (HET)-, or total (KO)-deficient BALB/c female mice with Hmox1-WT or -KO BALB/c males and performed ultrasound analysis to monitor placental and fetal growth. Doppler measurements were used to determine maternal blood flow parameters. Offspring weights and feto-placental indices (FPI) were also determined. We found a significantly increased number of underdeveloped fetuses at gd10 in HET females that were mated with WT males compared with WT × WT pairings. At the same gestational age, underdeveloped placentas could be detected in HET females mated with KO males. Many fetuses from the KO × KO combination died in utero between gd12 and gd14. At gd14, abnormal placental parameters were found in surviving fetuses, which had significant reduced weights. Moreover, only 3.11% female and 5.33% male KO pups resulted from 10 HET × HET breeding pairs over 1 year. Our results show that HO-1 from both maternal and paternal origins is important for proper placental and fetal growth. Placental growth restriction and occurrence of abortions in mice that were partially or totally deficient in HO-1 were recorded in vivo from gd10 onwards. Future studies will focus on elucidating the cellular and molecular mechanisms behind these observations.

The Global Pregnancy Collaboration (CoLab) Biobank of rare placentas

Many adverse pregnancy outcomes are the result of placental disorders. It has been difficult to decipher the root cause of many of these disorders due to an overlap in identifiable placental pathology and pregnancy outcomes. The reason for this confusion may be related to the lack of an appropriate control placenta. An ideal control placenta that is not related to adverse pregnancy outcomes is rare. We propose our pooled database at the Global Pregnancy Collaboration (CoLab) could be a solution for researchers.

Tryptophan metabolism and immune regulation in the human placenta

The placenta represents the maternal-fetal vascular interface. It is capable of supplying the bioenergetic needs of the developing conceptus. It is composed of different cell types that engage in highly varied functions, ranging from attachment, invasion and vascular remodeling to cell fusion, hormone production, and nutrient transport. A deep knowledge of the immunological mechanisms responsible for maintaining an active tolerance towards an allogeneic fetus and the anti-inflammatory properties of the placenta can be useful to clarify the pathogenesis of adverse events in pregnancy. While the systemic mechanisms of this immunological regulation in pregnancy have been well studied, the metabolic processes involved in the placental immune response are still poorly understood. The aim of this review is to summarize the most important information concerning the immune regulation in pregnancy, focusing on the role of tryptophan (Trp) catabolism performed by indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) in the placenta.

Placental mitochondrial function as a driver of angiogenesis and placental dysfunction

The placenta is a highly vascularized and complex foetal organ that performs various tasks, crucial to a healthy pregnancy. Its dysfunction leads to complications such as stillbirth, preeclampsia, and intrauterine growth restriction. The specific cause of placental dysfunction remains unknown. Recently, the role of mitochondrial function and mitochondrial adaptations in the context of angiogenesis and placental dysfunction is getting more attention. The required energy for placental remodelling, nutrient transport, hormone synthesis, and the reactive oxygen species leads to oxidative stress, stemming from mitochondria. Mitochondria adapt to environmental changes and have been shown to adjust their oxygen and nutrient use to best support placental angiogenesis and foetal development. Angiogenesis is the process by which blood vessels form and is essential for the delivery of nutrients to the body. This process is regulated by different factors, pro-angiogenic factors and anti-angiogenic factors, such as sFlt-1. Increased circulating sFlt-1 levels have been linked to different preeclamptic phenotypes. One of many effects of increased sFlt-1 levels, is the dysregulation of mitochondrial function. This review covers mitochondrial adaptations during placentation, the importance of the anti-angiogenic factor sFlt-1in placental dysfunction and its role in the dysregulation of mitochondrial function.

The Role of ApoE Expression and Variability of Its Glycosylation in Human Reproductive Health in the Light of Current Information

Apolipoprotein E (ApoE), a 34-kDa glycoprotein, as part of the high-density lipoprotein (HDL), has antioxidant, anti-inflammatory and antiatherogenic properties. The variability of ApoE expression in the course of some female fertility disorders (endometriosis, POCS), and other gynecological pathologies such as breast cancer, choriocarcinoma, endometrial adenocarcinoma/hyperplasia and ovarian cancer confirm the multidirectional biological function of ApoE, but the mechanisms of its action are not fully understood. It is also worth taking a closer look at the associations between ApoE expression, the type of its genotype and male fertility disorders. Another important issue is the variability of ApoE glycosylation. It is documented that the profile and degree of ApoE glycosylation varies depending on where it occurs, the type of body fluid and the place of its synthesis in the human body. Alterations in ApoE glycosylation have been observed in the course of diseases such as preeclampsia or breast cancer, but little is known about the characteristics of ApoE glycans analyzed in human seminal and blood serum/plasma in the context of male reproductive health. A deeper analysis of ApoE glycosylation in the context of female and male fertility will both enable us to broaden our knowledge of the biochemical and cellular mechanisms in which glycans participate, having a direct or indirect relationship with the fertilization process, and also give us a chance of contributing to the enrichment of the diagnostic panel in infertile women and men, which is particularly important in procedures involved in assisted reproductive techniques. Moreover, understanding the mechanisms of glycoprotein glycosylation related to the course of various diseases and conditions, including infertility, and the interactions between glycans and their specific ligands may provide us with an opportunity to interfere with their course and thus develop new therapeutic strategies. This brief overview details some of the recent advances, mainly from the last decade, in understanding the associations between ApoE expression and some female and male fertility problems, as well as selected female gynecological diseases and male reproductive tract disorders. We were also interested in how ApoE glycosylation changes influence biological processes in the human body, with special attention to human fertility.

Current State of Preeclampsia Mouse Models: Approaches, Relevance, and Standardization

Preeclampsia (PE) is a multisystemic, pregnancy-specific disorder and a leading cause of maternal and fetal death. PE is also associated with an increased risk for chronic morbidities later in life for mother and offspring. Abnormal placentation or placental function has been well-established as central to the genesis of PE; yet much remains to be determined about the factors involved in the development of this condition. Despite decades of investigation and many clinical trials, the only definitive treatment is parturition. To better understand the condition and identify potential targets preclinically, many approaches to simulate PE in mice have been developed and include mixed mouse strain crosses, genetic overexpression and knockout, exogenous agent administration, surgical manipulation, systemic adenoviral infection, and trophoblast-specific gene transfer. These models have been useful to investigate how biological perturbations identified in human PE are involved in the generation of PE-like symptoms and have improved the understanding of the molecular mechanisms underpinning the human condition. However, these approaches were characterized by a wide variety of physiological endpoints, which can make it difficult to compare effects across models and many of these approaches have aspects that lack physiological relevance to this human disorder and may interfere with therapeutic development. This report provides a comprehensive review of mouse models that exhibit PE-like symptoms and a proposed standardization of physiological characteristics for analysis in murine models of PE.

The role of resistin in early preeclampsia prediction

Resistin might be involved with general inflammation and endothelial dysfunction observed in preeclampsia. We aimed to investigate longitudinal changes in resistin concentrations during high-risk pregnancies and evaluate their significance in preeclampsia development. Ninety-one patients were recruited at 11-14 weeks of gestation. They were followed towards the end of each trimester and before their deliveries. Of the 91 pregnant women, 21 developed preeclampsia, while 70 women did not develop preeclampsia despite being at risk. Compared to the 1^st trimester, resistin concentration significantly increased during the 2^nd trimester (p<.001). When women were divided into groups of those who developed preeclampsia and those who did not develop preeclampsia, we noticed a significant difference only in women who did not develop preeclampsia (p<.001). Moreover, resistin concentration in the 1^st trimester was statistically higher in women who developed preeclampsia when compared to those who did not develop preeclampsia (p<.001). The analysis of the Receiver Operating Characteristics (ROC) curves indicated that inclusion of triglycerides (TG), high-sensitivity C-reactive protein (CRP), and resistin (AUC = 0.870) improved diagnostic accuracy of the basic model including demographic and clinical parameters (AUC = 0.777) for preeclampsia prediction (p<.05). If the concentration of resistin is high in the 1^st trimester, such pregnancy at risk is likely to develop preeclampsia as a complication, indicating that resistin concentration in the 1^st trimester might contribute to existing predictive and prognostic models for preeclampsia. A multi-marker model, possibly including also resistin and other clinical, metabolic, and inflammatory parameters, seems to be the best approach in late-onset preeclampsia prediction.

The Role of Oxidative Stress in Hypertensive Disorders of Pregnancy (Preeclampsia, Gestational Hypertension) and Metabolic Disorder of Pregnancy (Gestational Diabetes Mellitus)

Purpose of the Review.To highlight the role of oxidative stress in hypertensive disorders of pregnancy (HDP) and metabolic disorders of pregnancy (gestational diabetes mellitus). Recent Findings. In both preeclampsia (PE) and gestational hypertension (GH), oxidative stress leads to inadequate placental perfusion thus resulting in a hypoxic placenta, which generally leads to the activation of maternal systemic inflammatory response. In PE, this causes inflammation in the kidneys and leads to proteinuria. A proteinuria marker known as urinary 8-oxoGuo excretion is expressed in preeclampsia. In GDM, oxidative stress plays a role in the pathogenesis of the disease, as a result of over secretion of insulin during pregnancy. This uncontrolled secretion of insulin results in the production of lipid peroxidation factors that also mask the secretion of antioxidants. Therefore, ROS becomes abundant at cellular level and prevents the cells from transporting glucose to body tissues. Summary. There is a need for more research investigating the role of oxidative stress, especially in obstetrics-related conditions. More studies are required in order to understand the difference between the pathogenesis and pathophysiology of PE versus GH since investigations on the differences in genetic aspects of each condition are lacking. Furthermore, research to improve diagnostic procedures for GDM in pregnancy is needed.

Can a Difference in Gestational Age According to Biparietal Diameter and Abdominal Circumference Predict Intrapartum Placental Abruption?

This study aimed to investigate whether a difference in gestational age according to biparietal diameter (BPD) and abdominal circumference (AC) could be a clinically useful predictor of placental abruption during the intrapartum period. This retrospective cohort study was based on singletons who were delivered after 32 + 0 weeks between July 2015 and July 2020. We only included cases with at least two antepartum sonographies available within 4 weeks of delivery (n = 2790). We divided the study population into two groups according to the presence or absence of placental abruption and compared the clinical variables. The incidence of placental abruption was 2.0% (56/2790) and was associated with an older maternal age, a higher rate of preeclampsia, and being small for the gestational age. A difference of >2 weeks in gestational age according to BPD and AC occurred at a higher rate in the placental abruption group compared to the no abruption group (>2 weeks, 21.4% (12/56) vs. 7.5% (205/2734), p < 0.001; >3 weeks, 12.5% (7/56) vs. 2.0% (56/2734), p < 0.001). Logistic regression analysis revealed that the differences of >2 weeks and >3 weeks were both independent risk factors for placental abruption (odds ratio (OR) (95% confidence interval), 2.289 (1.140-4.600) and 3.918 (1.517-9.771), respectively) after adjusting for maternal age, preeclampsia, and small for gestational age births. We identified that a difference in gestational age of >2 weeks between BPD and AC could be an independent predictor of placental abruption.

Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery

Functional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue's scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

The Role of Leptin in Fetal Growth during Pre-Eclampsia

Leptin is secreted by the placenta and has a multi-facetted role in the regulation of functions related to pregnancy. Metabolic disorders and insufficient homeostatic compensatory mechanisms involving leptin during pregnancy play a decisive role in the development of pre-eclampsia (PE) and give rise to compromised intrauterine growth conditions and aberrant birth weight of offspring. This review was compiled to elucidate the metabolic background of PE and its relationship with adverse intrauterine growth conditions through the examination of leptin as well as to describe possible mechanisms linking leptin to fetal growth restriction. This review illustrates that leptin in PE is dysregulated in maternal, fetal, and placental compartments. There is no single set of unifying mechanisms within the spectrum of PE, and regulatory mechanisms involving leptin are specific to each situation. We conclude that dysregulated leptin is involved in fetal growth at many levels through complex interactions with parallel pregnancy systems and probably throughout the entirety of pregnancy.

Abnormal development of cerebral arteries and veins in offspring of experimentally preeclamptic rats: Potential role in perinatal stroke

Preeclampsia, a hypertensive disorder of pregnancy, complicates up to 10 % of all pregnancies and increases the risk for perinatal stroke in offspring. The mechanism of this increase is unknown, but may involve vascular dysfunction. The goal of this study was to evaluate the effect of experimental preeclampsia (ePE) on cerebrovascular function in offspring to eludciate a possible mechanism for this association. Dams were fed a high cholesterol diet beginning on day 7 of gestation to induce experimental preeclampsia. Middle cerebral arteries (MCA) and the Vein of Galen (VoG) were isolated from pups from ePE dams and compared to pups from normal pregnant (NP) dams at postnatal days 16, 23, and 30 and studied pressurized in an arteriograph chamber. Markers of inflammation and oxidative stress were measured in serum. Our results suggest altered structure and function in both MCA and VoG of ePE pups. We also found evidence of systemic inflammation and oxidative stress in ePE pups. These findings provide a potential link between preeclampsia and the occurrence or severity of perinatal stroke.

Severe Preeclampsia is Associated with Functional and Structural Cardiac Alterations: A Case-control Study

BACKGROUND

The aim of the current study is to compare electrocardiographic and echocardiographic changes in patients with severe preeclampsia (PE) and those with uncomplicated pregnancies.

METHODS

This is a case-controlled prospective study consisting of 21 pregnant women with severe preeclampsia and a control group consisting of age- and gestational age-matched 24 healthy pregnant women. All patients underwent electrocardiographic and echocardiographic investigation.

RESULTS

QRS intervals were shorter and PR intervals were longer in the PE group (QRS duration: 80 (60-120) ms and 80 (40-110) ms, p=0.035; PR duration: 160 (100-240) ms and 120 (80-200) ms, respectively; p=0.046). The left ventricular end-systolic diameters of the patients with severe PE group were significantly larger than the control group (31 (24-36) mm and 30 (24-33) mm, respectively; p=0.05). Similarly, posterior wall thickness values of the PE group were significantly higher compared to the control group (9 (7-11) mm vs. 8 (6-10) mm, respectively; p=0.020). Left ventricular mass (146.63±27.73 g and 128.69±23.25 g, respectively; p=0.033) and relative wall thickness values (0.385±0.054 and 0.349±0.046, respectively; p=0.030) were also higher in the PE group. In addition, patients with early-onset severe PE had significantly a higher left ventricular end-diastolic diameter and volume compared with late-onset PE patients.

CONCLUSIONS

The structural changes detected in the severe PE group suggest a chronic process rather than an acute effect. In addition, diastolic dysfunction and left ventricular remodeling are most marked in patients with severe early-onset PE.

Effects of Nrf-2 expression in trophoblast cells and vascular endothelial cells in preeclampsia

The present study aimed to explore the role of kelch-like ECH-associated protein-1 (Keap1)/Nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling pathway in regulating heme oxygenase-1 (HO-1) expression in adverse outcomes of preeclampsia (PE). Adult Wistar rats, HTR-8/SVneo and hESC cells were used for models in vitro and in vivo, respectively. Inhibition of Nrf-2 could slightly reduce the elevation of systolic blood pressure (SBP) and urinary protein in PE rats. The percentages of dead fetuses during pregnancy and within seven days of birth were decreased by Nrf-2 inhibitor. There was no significant effect on the pathology and HO-1 expression of Nrf-2 in placental tissue. Deficiency of Nrf-2 increased significantly the levels of chemokine 2 (CCL2), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), angiotensin II receptor type 1 (AT1R) and reactive oxygen species (ROS) in the embryonic tissues. Knockdown of Nrf-2 suppressed cell proliferation, improved cell apoptosis and invasion with an increase of ROS and HO-1, but the effect on cells apoptosis was greater. Activation of Nrf-2 pathway could reduce oxidative stress in PE rats and trophoblast cells induced by Ang II, and enhance the adverse outcome of PE via increasing HO-1. Nrf-2 silence reshaped blood vessels and achieved the effect of treating PE. Our results might provide theoretical guidance for the application of Nrf-2 in the treatment of PE.

Maternal systemic vascular dysfunction in a primate model of defective uterine spiral artery remodeling

Uterine spiral artery remodeling (UAR) is essential for placental perfusion and fetal development. A defect in UAR underpins placental ischemia disorders, e.g., preeclampsia, that result in maternal systemic vascular endothelial dysfunction and hypertension. We have established a model of impaired UAR by prematurely elevating maternal serum estradiol levels during the first trimester of baboon pregnancy. However, it is unknown whether this experimental paradigm is associated with maternal vascular endothelial dysfunction. Therefore, in the present study baboons were administered estradiol on days 25-59 of gestation to suppress UAR and maternal vascular function determined on day 165 (term = 184 days) peripherally and in skeletal muscle, which accounts for over 40% of body mass and 25% of resting systemic vascular resistance. Maternal serum sFlt-1 levels were 2.5-fold higher (P < 0.05), and skeletal muscle arteriolar endothelial nitric oxide synthase (eNOS) protein expression and luminal area, and skeletal muscle capillary density were 30-50% lower (P < 0.05) in UAR suppressed baboons. Coinciding with these changes in eNOS expression, luminal area, and capillary density, maternal brachial artery flow-mediated dilation and volume flow were 70% and 55% lower (P < 0.05), respectively, and mean arterial blood pressure 29% higher (P < 0.01) in UAR defective baboons. In summary, maternal vascular function was disrupted in a baboon model of impaired UAR. These results highlight the translational impact of this primate model and relevance to adverse conditions of human pregnancy underpinned by improper uterine artery transformation.NEW & NOTEWORTHY Maternal vascular dysfunction is a hallmark of abnormal human pregnancy, particularly early-onset preeclampsia, elicited by impaired UAR. The present study makes the novel discovery that maternal systemic vascular dysfunction was induced in a baboon experimental model of impaired UAR. This study highlights the translational relevance of this nonhuman primate model to adverse conditions of human pregnancy underpinned by defective UAR.

Effect of Selenium and Iodine on Oxidative Stress in the First Trimester Human Placenta Explants

Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p < 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p < 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.

MicroRNA-mRNA Networks in Pregnancy Complications: A Comprehensive Downstream Analysis of Potential Biomarkers

Pregnancy complications are a major cause of fetal and maternal morbidity and mortality in humans. The majority of pregnancy complications initiate due to abnormal placental development and function. During the last decade, the role of microRNAs (miRNAs) in regulating placental and fetal development has become evident. Dysregulation of miRNAs in the placenta not only affects placental development and function, but these miRNAs can also be exported to both maternal and fetal compartments and affect maternal physiology and fetal growth and development. Due to their differential expression in the placenta and maternal circulation during pregnancy complications, miRNAs can be used as diagnostic biomarkers. However, the differential expression of a miRNA in the placenta may not always be reflected in maternal circulation, which makes it difficult to find a reliable biomarker for placental dysfunction. In this review, we provide an overview of differentially expressed miRNAs in the placenta and/or maternal circulation during preeclampsia (PE) and intrauterine growth restriction (IUGR), which can potentially serve as biomarkers for prediction or diagnosis of pregnancy complications. Using different bioinformatics tools, we also identified potential target genes of miRNAs associated with PE and IUGR, and the role of miRNA-mRNA networks in the regulation of important signaling pathways and biological processes.

Downregulation of aromatase plays a dual role in preeclampsia

Preeclampsia (PE) is a gestational disease, which seriously impairs maternal and infant health. However, the pathogenesis of PE remains unclear. The aromatase (CYP19A1) in placenta converts androgens from maternal and fetal adrenal glands to estrogen. Therefore, this change in the aromatase expression or function and the subsequent change of steroids in the placenta could be related to the pathophysiology of PE. In this study, we first analyzed the expression of CYP19A1 in clinical placental tissues as well as the level of sex hormones in corresponding serum samples. The results showed that the expression of aromatase in the placenta of PE patients was relatively low and accompanied by a sex hormone imbalance. Subsequently, animal experiments showed that ischemia and hypoxia lead to a low expression of CYP19A1, and that PE-like symptoms appear in pregnant mice following decreased or inhibited CYP19A1 expression. It was also found that, with the downregulation of CYP19A1 expression, the invasion and migration abilities of trophoblast cells were enhanced, which benefited placental implantation. However, alongside this, apoptosis and the inflammatory response were also increased, which was detrimental to placental development. Phosphoproteomic analyses revealed that the activation of the PI3K/AKT signaling pathway may play a key role in these processes. In conclusion, the downregulation of aromatase has a dual role in PE, among which the induction of the disease is the main role. Our study provides a potential novel method for the early prediction and treatment of PE.

Maternal Serum Cytokine Concentrations in Healthy Pregnancy and Preeclampsia

The maternal immune response is essential for successful pregnancy, promoting immune tolerance to the fetus while maintaining innate and adaptive immunity. Uncontrolled, increased proinflammatory responses are a contributing factor to the pathogenesis of preeclampsia. The Th1/Th2 cytokine shift theory, characterised by bias production of Th2 anti-inflammatory cytokine midgestation, was frequently used to reflect the maternal immune response in pregnancy. This theory is simplistic as it is based on limited information and does not consider the role of other T cell subsets, Th17 and Tregs. A range of maternal peripheral cytokines have been measured in pregnancy cohorts, albeit the changes in individual cytokine concentrations across gestation is not well summarised. Using available data, this review was aimed at summarising changes in individual maternal serum cytokine concentrations throughout healthy pregnancy and evaluating their association with preeclampsia. We report that TNF-α increases as pregnancy progresses, IL-8 decreases in the second trimester, and IL-4 concentrations remain consistent throughout gestation. Lower second trimester IL-10 concentrations may be an early predictor for developing preeclampsia. Proinflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-8, and IL-6) are significantly elevated in preeclampsia. More research is required to determine the usefulness of using cytokines, particularly IL-10, as early biomarkers of pregnancy health.

The association between dietary fatty acid intake and the risk of developing preeclampsia: a matched case-control study

The association between dietary fat intake during pregnancy and the risk of developing preeclampsia has been examined in many epidemiological studies, but the results remain inconsistent. The aim of this study was to clarify this association in pregnant Chinese women. After conducting 1:1 matching, 440 pairs consisting of pregnant women with preeclampsia and hospital-based, healthy pregnant women matched by gestational week (± 1 week) and age (± 3 years) were recruited. A 79-item semi-quantitative food frequency questionnaire administered during face-to-face interviews was used to estimate the participants’ dietary intake of fatty acids. We found that the intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were inversely associated with the risk of developing preeclampsia. Compared with the lowest quartile intake, the multivariate-adjusted odds ratios (95% confidence interval) of the highest quartile intake were 0.42 (0.26–0.68, p-trend < 0.001) for EPA, 0.52 (0.3–0.83, p-trend = 0.005) for DHA, and 0.41 (0.19–0.88, p-trend = 0.007) for AA. However, we did not observe any significant associations between the intake of total fatty acids, saturated fatty acids, and mono-unsaturated fatty acids and the risk of developing preeclampsia. Our results showed that the dietary intake of long-chain polyunsaturated fatty acids (i.e., EPA, DHA, and AA) may protect pregnant Chinese women against the development of preeclampsia.

Relative Sinus Bradycardia: An Unexpected Finding in Preeclampsia With Acute Pulmonary Edema

Preeclampsia is a multifactorial pregnancy-specific syndrome, which can result in significant alterations in cardiovascular hemodynamics. We report an observation of unexpected relative bradycardia in a previously healthy woman who presented with postpartum preeclampsia and acute pulmonary edema. We observed an increase in heart rate following normalization of blood pressure, which suggested that the initial slower than expected heart rate may reflect a baroreceptor response to hypertension. Whether this finding should be regarded as a severe aspect of the disease spectrum needs further study.

Decidual and placental NOD1 is associated with inflammation in normal and preeclamptic pregnancies

INTRODUCTION

Inflammation is a normal physiological process that increases to harmful levels in preeclampsia. It affects the interaction between maternal immune cells and fetal trophoblasts at both sites of the maternal-fetal interface; decidua and placenta. The pattern recognition receptor nucleotide-binding oligomerization domain-containing protein (NOD)1 is expressed at both sites. This study aimed to characterize the cellular expression and functionality of NOD1 at the maternal-fetal interface of normal and preeclamptic pregnancies.

METHODS

Women with normal or preeclamptic pregnancies delivered by caesarean section were included. Decidual (n = 90) and placental (n = 91) samples were analyzed for NOD1 expression by immunohistochemistry and an automated image-based quantification method. Decidual and placental explants were incubated with or without the NOD1-agonist iE-DAP and cytokine responses measured by ELISA.

RESULTS

NOD1 was markedly expressed by maternal cells in the decidua and by fetal trophoblasts in both decidua and placenta, with trophoblasts showing the highest NOD1 expression. Preeclampsia with normal fetal growth was associated with a trophoblast-dependent increase in decidual NOD1 expression density. Compared to normal pregnancies, preeclampsia demonstrated stronger correlation between decidual and placental NOD1 expression levels. Increased production of interleukin (IL)-6 or IL-8 after in vitro explant stimulation confirmed NOD1 functionality.

DISCUSSION

These findings suggest that NOD1 contributes to inflammation at the maternal-fetal interface in normal pregnancies and preeclampsia and indicate a role in direct maternal-fetal communication. The strong expression of NOD1 by all trophoblast types highlights the importance of combined assessment of decidua and placenta for overall understanding of pathophysiological processes at the maternal-fetal interface.

Placental mitochondrial function in response to gestational exposures

Poor environmental conditions, including malnutrition, hypoxia and obesity in the mother increase the risk of pregnancy complications, such as pre-eclampsia and gestational diabetes mellitus, which impacts the lifelong health of the mother and her offspring. The placenta plays an important role in determining pregnancy outcome by acting as an exchange interface and endocrine hub to support fetal growth. Mitochondria are energy powerhouses of cells that fuel placental physiology throughout pregnancy, including placental development, substrate exchange and hormone secretion. They are responsive to environmental cues and changes in mitochondrial function may serve to mediate or mitigate the impacts of poor gestational environments on placental physiology and hence, the risks of pregnancy complications. Thus, a more integrated understanding about the role of placental mitochondria in orchestrating changes in relation to environmental conditions and pregnancy outcome is paramount. This review summarises the functions of mitochondria in the placenta and findings from humans and experimental animals that demonstrate how mitochondrial structure and function are altered in different gestational environments (namely complicated pregnancies and adverse environmental conditions). Together the available data suggest that mitochondria in the placenta play a major role in determining placental physiology, fetal growth and pregnancy outcome.

High altitude regulates the expression of AMPK pathways in human placenta

INTRODUCTION

High-altitude (>2500 m) residence augments the risk of intrauterine growth restriction (IUGR) and preeclampsia likely due, in part, to uteroplacental hypoperfusion. Previous genomic and transcriptomic studies in humans and functional studies in mice and humans suggest a role for AMP-activated protein kinase (AMPK) pathway in protecting against hypoxia-associated IUGR. AMPK is a metabolic sensor activated by hypoxia that is ubiquitously expressed in vascular beds and placenta.

METHODS

We measured gene expression and protein levels of AMPK and its upstream regulators and downstream targets in human placentas from high (>2500 m) vs. moderate (~1700 m) and low (~100 m) altitude.

RESULTS

We found that phosphorylated AMPK protein levels and its downstream target TSC2 were increased in placentas from high and moderate vs. low altitude, whereas the phosphorylated form of the downstream target translation repressor protein 4E-BP1 was increased in high compared to moderate as well as low altitude placentas. Mean birth weights progressively fell with increasing altitude but no infants, by study design, were clinically growth-restricted. Gene expression analysis showed moderate increases in PRKAG2, encoding the AMPK γ2 subunit, and mechanistic target of rapamycin, MTOR, expression.

DISCUSSION

These results highlight a differential regulation of placental AMPK pathway activation in women residing at low, moderate or high altitude during pregnancy, suggesting AMPK may be serving as a metabolic regulator for integrating hypoxic stimuli with placental function.

Improvement Effect of Metformin on Female and Male Reproduction in Endocrine Pathologies and Its Mechanisms

Metformin (MF), a first-line drug to treat type 2 diabetes mellitus (T2DM), alone and in combination with other drugs, restores the ovarian function in women with polycystic ovary syndrome (PCOS) and improves fetal development, pregnancy outcomes and offspring health in gestational diabetes mellitus (GDM) and T2DM. MF treatment is demonstrated to improve the efficiency of in vitro fertilization and is considered a supplementary drug in assisted reproductive technologies. MF administration shows positive effect on steroidogenesis and spermatogenesis in men with metabolic disorders, thus MF treatment indicates prospective use for improvement of male reproductive functions and fertility. MF lacks teratogenic effects and has positive health effect in newborns. The review is focused on use of MF therapy for restoration of female and male reproductive functions and improvement of pregnancy outcomes in metabolic and endocrine disorders. The mechanisms of MF action are discussed, including normalization of metabolic and hormonal status in PCOS, GDM, T2DM and metabolic syndrome and restoration of functional activity and hormonal regulation of the gonadal axis.

Genomic imbalances in the placenta are associated with poor fetal growth

Background

Fetal growth restriction (FGR) is associated with increased risks for complications before, during, and after birth, in addition to risk of disease through to adulthood. Although placental insufficiency, failure to supply the fetus with adequate nutrients, underlies most cases of FGR, its causes are diverse and not fully understood. One of the few diagnosable causes of placental insufficiency in ongoing pregnancies is the presence of large chromosomal imbalances such as trisomy confined to the placenta; however, the impact of smaller copy number variants (CNVs) has not yet been adequately addressed. In this study, we confirm the importance of placental aneuploidy, and assess the potential contribution of CNVs to fetal growth.

Methods

We used molecular-cytogenetic approaches to identify aneuploidy in placentas from 101 infants born small-for-gestational age (SGA), typically used as a surrogate for FGR, and from 173 non-SGA controls from uncomplicated pregnancies. We confirmed aneuploidies and assessed mosaicism by microsatellite genotyping. We then profiled CNVs using high-resolution microarrays in a subset of 53 SGA and 61 control euploid placentas, and compared the load, impact, gene enrichment and clinical relevance of CNVs between groups. Candidate CNVs were confirmed using quantitative PCR.

Results

Aneuploidy was over tenfold more frequent in SGA-associated placentas compared to controls (11.9% vs. 1.1%; p = 0.0002, OR = 11.4, 95% CI 2.5–107.4), was confined to the placenta, and typically involved autosomes, whereas only sex chromosome abnormalities were observed in controls. We found no significant difference in CNV load or number of placental-expressed or imprinted genes in CNVs between SGA and controls, however, a rare and likely clinically-relevant germline CNV was identified in 5.7% of SGA cases. These CNVs involved candidate genes INHBB, HSD11B2, CTCF, and CSMD3.

Conclusions

We conclude that placental genomic imbalances at the cytogenetic and submicroscopic level may underlie up to ~ 18% of SGA cases in our population. This work contributes to the understanding of the underlying causes of placental insufficiency and FGR, which is important for counselling and prediction of long term outcomes for affected cases.

Role of maternal nutrition and oxidative stress in placental telomere attrition in women with preeclampsia

Background:Maternal nutrition influences the growth and development of the fetus and influences pregnancy outcome. We have earlier demonstrated altered maternal nutrition and increased oxidative stress in women with preeclampsia. Oxidative stress is known to be associated with reduced telomere length and short telomere aggregates. Increased telomere attrition leads to increased cellular senescence and tissue ageing. Methods:The present review focuses on the role of maternal nutrition and oxidative stress in telomere attrition in preeclampsia. Results and Conclusion:Future studies need to examine the association between maternal nutritional status in early pregnancy, oxidative stress and telomere attrition in preeclampsia.

miR-16-5p, miR-103-3p, and miR-27b-3p as Early Peripheral Biomarkers of Fetal Growth Restriction

Current tests available to diagnose fetal hypoxia in-utero lack sensitivity thus failing to identify many fetuses at risk. Emerging evidence suggests that microRNAs derived from the placenta circulate in the maternal blood during pregnancy and may be used as non-invasive biomarkers for pregnancy complications. With the intent to identify putative markers of fetal growth restriction (FGR) and new therapeutic druggable targets, we examined, in maternal blood samples, the expression of a group of microRNAs, known to be regulated by hypoxia. The expression of microRNAs was evaluated in maternal plasma samples collected from (1) women carrying a preterm FGR fetus (FGR group) or (2) women with an appropriately grown fetus matched at the same gestational age (Control group). To discriminate between early- and late-onset FGR, the study population was divided into two subgroups according to the gestational age at delivery. Four microRNAs were identified as possible candidates for the diagnosis of FGR: miR-16-5p, miR-103-3p, miR-107-3p, and miR-27b-3p. All four selected miRNAs, measured by RT-PCR, resulted upregulated in FGR blood samples before the 32nd week of gestation. By contrast, miRNA103-3p and miRNA107-3p, analyzed between the 32nd and 37th week of gestation, showed lower expression in the FGR group compared to aged matched controls. Our results showed that measurement of miRNAs in maternal blood may form the basis for a future diagnostic test to determine the degree of fetal hypoxia in FGR, thus allowing the start of appropriate therapeutic interventions to alleviate the burden of this disease.

The association of MOV10 polymorphism and expression levels with preeclampsia in the Chinese Han population

BACKGROUND

To assess the relationship between MOV10 rs2932538 polymorphism and susceptibility to preeclampsia (PE) in the Chinese Han population and to investigate whether the placental expression of MOV10 have association with PE.

METHODS

We enrolled 1021 pregnant women with PE and 1594 normotensive pregnant women to analyze genotyping of MOV10 rs2932538. Clinical data and related test results of all subjects were collected and analyzed. For volunteers providing placentas, real-time PCR, Western blot, and immunohistochemistry were applied to assess the expression level of MOV10.

RESULTS

There was significant statistical difference between preeclamptic patients and healthy subjects in genotype distributions and alleles. The frequencies of genotypes TT+CT were significantly associated with the increased risk of preeclampsia. Besides, T alleles were found to be related to a higher risk of PE. Significant statistical difference was also observed on distributions of genotype in PE without/with severe features group compared or early onset/late onset versus controls. The placental expression of MOV10 was lower in preeclamptic women, however, no relationship was found between MOV10 expression level and MOV10 rs2932538 genotypes.

CONCLUSION

This study suggests that MOV10 rs2932538 polymorphism may be associated with PE susceptibility in the Chinese Han population. The placental expression of MOV10 decrease in PE but have no relationship with rs2932538 polymorphism.

Role of first-trimester three-dimensional (3D) power Doppler of placental blood flow and 3D placental volume in early prediction of pre-eclampsia

OBJECTIVE

To assess the efficacy of first-trimester three-dimensional (3D) placental volume as well as 3D power Doppler of placental vascular indices for early prediction of pre-eclampsia.

METHODS

The prospective cohort study included over 2019 women with a singleton pregnancy in their first trimester at 11-13+ weeks of pregnancy. All women were examined by 3D abdominal ultrasound, including Doppler techniques for the placental volume and placental vascular indices. Uterine artery Doppler indices were also assessed. All participants were cared for until delivery for assessment of pregnancy outcomes.

RESULTS

In all, 163 women developed pre-eclampsia while 1856 women remained normotensive. The women with pre-eclampsia had significantly lower placental volume (77.09 ml vs. 99.8 ml, p < 0.001), and placental vascular indices (vascularization index, flow index, and vascularization flow index were 7.41 vs. 9.89, 39.03 vs. 46.63, and 2.77 vs. 4.4, respectively, p < 0.001). In contrast, women with pre-eclampsia had significantly high mean uterine pulsatility index and resistance index (2.02 vs. 1.11, 0.83 vs. 0.64, respectively, p < 0.001) compared with the normotensive women. The placental vascular indices were highly sensitive, whereas the placental volume and the mean uterine pulsatility index and resistance index had higher specificity for the prediction of pre-eclampsia.

CONCLUSION

First-trimester assessment through 3D placental volume and power Doppler of placental vascular indices, especially in combination with uterine artery Doppler assessment, revealed an increase in the accuracy of early detection of women at risk for developing pre-eclampsia.

Pregnancy-Induced High Plasma Levels of Soluble Endoglin in Mice Lead to Preeclampsia Symptoms and Placental Abnormalities

Preeclampsia is a pregnancy-specific disease of high prevalence characterized by the onset of hypertension, among other maternal or fetal signs. Its etiopathogenesis remains elusive, but it is widely accepted that abnormal placentation results in the release of soluble factors that cause the clinical manifestations of the disease. An increased level of soluble endoglin (sEng) in plasma has been proposed to be an early diagnostic and prognostic biomarker of this disease. A pathogenic function of sEng involving hypertension has also been reported in several animal models with high levels of plasma sEng not directly dependent on pregnancy. The aim of this work was to study the functional effect of high plasma levels of sEng in the pathophysiology of preeclampsia in a model of pregnant mice, in which the levels of sEng in the maternal blood during pregnancy replicate the conditions of human preeclampsia. Our results show that wild type pregnant mice carrying human sEng-expressing transgenic fetuses (fWT(hsEng⁺)) present high plasma levels of sEng with a timing profile similar to that of human preeclampsia. High plasma levels of human sEng (hsEng) are associated with hypertension, proteinuria, fetal growth restriction, and the release of soluble factors to maternal plasma. In addition, fWT(hsEng⁺) mice also present placental alterations comparable to those caused by the poor remodeling of the spiral arteries characteristic of preeclampsia. In vitro and ex vivo experiments, performed in a human trophoblast cell line and human placental explants, show that sEng interferes with trophoblast invasion and the associated pseudovasculogenesis, a process by which cytotrophoblasts switch from an epithelial to an endothelial phenotype, both events being related to remodeling of the spiral arteries. Our findings provide a novel and useful animal model for future research in preeclampsia and reveal a much more relevant role of sEng in preeclampsia than initially proposed.

Low Bioactive Vitamin D Is Associated with Pregnancy-Induced Hypertension in a Cohort of Pregnant HIV-Infected Women Sampled Over a 23-Year Period

OBJECTIVE

To examine the association of vitamin D insufficiency and risk of pregnancy-induced hypertension (PIH) among human immunodeficiency virus (HIV)-infected pregnant women.

STUDY DESIGN

This is a retrospective cohort study evaluating the impact of low maternal vitamin D levels on PIH and perinatal outcomes among HIV-infected pregnant women receiving care at an urban HIV center from 1991 to 2014.

RESULTS

A total of 366 pregnant women were included, of which 11% developed PIH. Lower levels of 25-hydroxyvitamin D (25(OH)D) and bioactive 1,25-dihydroxyvitamin D (1,25(OH)2D) were associated with increased HIV disease activity. 25(OH)D levels were not significantly associated with the incidence of PIH. Higher 1,25(OH)2D levels were associated with reduced incidence of PIH in univariate (odds ratio, OR: 0.87 [95% confidence interval, CI: 0.79-0.95], p = 0.004) and multivariate (OR: 0.88 [95% CI: 0.80-0.97], p = 0.010) analyses. No association was found between 25(OH)D levels and other obstetric outcomes. Lower 1,25(OH)2D levels were associated with group B Streptococcus colonization (OR: 0.92 [95% CI: 0.86-0.99]) and low birth weight (LBW) (OR: 0.90 [95% CI: 0.83-0.98]) on multivariate analysis. Mean 1,25(OH)2D levels were significantly lower in women with preterm delivery and LBW infants.

CONCLUSION

Lower bioactive vitamin D levels are related to PIH in HIV-infected women. This association may be related to the coexistence of abnormal placental vitamin D metabolism and abnormal placental implantation.

Social Determinants of Placental Health and Future Disease Risks for Babies

Birthweight is a well-known predictor of adult-onset chronic disease. The placenta plays a necessary role in regulating fetal growth and determining birth size. Maternal stressors that affect placental function and prenatal growth include maternal overnutrition and undernutrition, toxic social stress, and exposure to toxic chemicals. These stressors lead to increased vulnerability to disease within any population. This vulnerability arises from placental and fetal exposure to stressors during fetal life. The biological drivers linking various social determinants of health to compromised placental function and fetal development have been little studied.

The Association of Tuberculosis Mono-infection and Tuberculosis-Human Immunodeficiency Virus (TB-HIV) Co-infection in the Pathogenesis of Hypertensive Disorders of Pregnancy

PURPOSE OF REVIEW

This review highlights the impact of TB mono-infection and TB-HIV co-infection on the pathogenesis of adverse maternal outcomes such as hypertensive disorders of pregnancy (HDP) and adverse fetal outcomes such as recurrent spontaneous abortion (RSA), fetal growth restriction (FGR), and low birth weight.

RECENT FINDINGS

Research has shown that HDP, such as severe pre-eclampsia (PE) and eclampsia, as well as adverse fetal outcomes such as recurrent spontaneous abortion, fetal growth restriction, and low birth weight, are higher in women diagnosed with TB mono-infection and even higher in TB-HIV co-infection compared to those without TB. This is speculated to occur due to exaggerated activation of both angiogenic factors such as vascular endothelial growth factor (VEGF), nitric oxide (NO), angiotensin 2, (Ang 2), intracellular adhesion molecules (ICAMs), and inflammatory cytokines such as interleukin 2 (IL-2), (IL-17), and interferon-gamma (INF-γ). There is a lack of information with regard to the pathogenesis of adverse maternal and fetal outcomes upon TB mono-infection and TB-HIV co-infection; therefore, further investigations on the impact of TB mono-infection and TB-HIV co-infection on adverse maternal and fetal outcomes are urgently needed. This will assist in improving diagnostic procedures in pregnant women affected with TB as wells as TB-HIV co-infection.

Single nuclei RNA-seq of mouse placental labyrinth development

The placenta is the interface between mother and fetus in all eutherian species. However, our understanding of this essential organ remains incomplete. A substantial challenge has been the syncytial cells of the placenta, which have made dissociation and independent evaluation of the different cell types of this organ difficult. Here, we address questions concerning the ontogeny, specification, and function of the cell types of a representative hemochorial placenta by performing single nuclei RNA sequencing (snRNA-seq) at multiple stages of mouse embryonic development focusing on the exchange interface, the labyrinth. Timepoints extended from progenitor-driven expansion through terminal differentiation. Analysis by snRNA-seq identified transcript profiles and inferred functions, cell trajectories, signaling interactions, and transcriptional drivers of all but the most highly polyploid cell types of the placenta. These data profile placental development at an unprecedented resolution, provide insights into differentiation and function across time, and provide a resource for future study.

Evaluation of BRD4 levels in patients with early-onset preeclampsia

OBJECTIVE

This study aimed to detect Bromodomain Containing Protein 4 (BRD4) concentrations in the serum of early-onset preeclamptic patients and compare them with the healthy control group.

MATERIAL AND METHODS

This prospective case-control study was performed from June 2019 to December 2019. Of the 80 pregnant patients included in the study, we enrolled 40 patients with early-onset preeclampsia as the study group, and 40 normotensive healthy gestational age- and gravidity-matched patients with normal blood pressure without proteinuria as the control group. Demographic characteristics, amount of proteinuria, and serum BRD4 concentrations were recorded.

RESULTS

Maternal serum BRD4 concentrations were significantly higher in patients with preeclampsia (39.10 ± 42.14 ng/mL) compared to the participants in the control group (13.64 ± 7.24 ng/mL, p < 0.001). There was a positive intermediate correlation between serum BRD4 levels and the amount of proteinuria (r = 0.447, p = 0.006).

CONCLUSION

Maternal serum BRD4 levels were significantly higher in preeclamptic patients compared to healthy pregnant women. Also, the amount of proteinuria was positively correlated with serum BRD4 levels. Although this preliminary study shows increased BRD4 levels in preeclampsia, its utility as a biomarker must be clarified.

Early-pregnancy transcriptome signatures of preeclampsia: from peripheral blood to placenta

Several studies have linked maternal asthma, excess BMI, and low vitamin D status with increased risk of Preeclampsia (PE) development. Given prior evidence in the literature and our observations from the subjects in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), we hypothesized that PE, maternal asthma, vitamin D insufficiency, and excess body mass index (BMI) might share both peripheral blood and placental gene signatures that link these conditions together. We used samples collected in the VDAART to investigate relationships between these four conditions and gene expression patterns in peripheral blood obtained at early pregnancy. We identified a core set of differentially expressed genes in all comparisons between women with and without these four conditions and confirmed them in two separate sets of samples. We confirmed the differential expression of the shared gene signatures in the placenta from an independent study of preeclampsia cases and controls and constructed the preeclampsia module using protein-protein interaction networks. CXC chemokine genes showed the highest degrees of connectivity and betweenness centrality in the peripheral blood and placental modules. The shared gene signatures demonstrate the biological pathways involved in preeclampsia at the pre-clinical stage and may be used for the prediction of preeclampsia.

Differences in Placental Imprinted Gene Expression across Preeclamptic and Non-Preeclamptic Pregnancies

Preeclampsia is a multi-systemic syndrome that presents in approximately 5% of pregnancies worldwide and is associated with a range of subsequent postpartum and postnatal outcomes, including fetal growth restriction. As the placenta plays a critical role in the development of preeclampsia, surveying genomic features of the placenta, including expression of imprinted genes, may reveal molecular markers that can further refine subtypes to aid targeted disease management. In this study, we conducted a comprehensive survey of placental imprinted gene expression across early and late onset preeclampsia cases and preterm and term normotensive controls. Placentas were collected at delivery from women recruited at the Magee-Womens Hospital prenatal clinics, and expression levels were profiled across 109 imprinted genes. We observed downregulation of placental Mesoderm-specific transcript (MEST) and Necdin (NDN) gene expression levels (false discovery rate (FDR) < 0.05) among early onset preeclampsia cases compared to preterm controls. No differences in placental imprinted gene expression were observed between late onset preeclampsia cases and term controls. While few studies have linked NDN to pregnancy complications, reductions in MEST expression levels, as observed in our study, are consistently reported in the literature in relation to various pregnancy complications, including fetal growth restriction, suggesting a potential role for placental MEST expression as a biosensor of an adverse in utero environment.

A Review of the Potential Interaction of Selenium and Iodine on Placental and Child Health

A healthy pregnancy is important for the growth and development of a baby. An adverse pregnancy outcome is associated with increased chronic disease risk for the mother and offspring. An optimal diet both before and during pregnancy is essential to support the health of the mother and offspring. A key mediator of the effect of maternal nutrition factors on pregnancy outcomes is the placenta. Complicated pregnancies are characterized by increased oxidative stress in the placenta. Selenium and iodine are micronutrients that are involved in oxidative stress in placental cells. To date, there has been no comprehensive review investigating the potential synergistic effect of iodine and selenium in the placenta and how maternal deficiencies may be associated with increased oxidative stress and hence adverse pregnancy outcomes. We undertook a hypothesis-generating review on selenium and iodine, to look at how they may relate to pregnancy complications through oxidative stress. We propose how they may work together to impact pregnancy and placental health and explore how deficiencies in these micronutrients during pregnancy may impact the future health of offspring.

Tracking placental development in health and disease

Pre-eclampsia and fetal growth restriction arise from disorders of placental development and have some shared mechanistic features. Initiation is often rooted in the maldevelopment of a maternal-placental blood supply capable of providing for the growth requirements of the fetus in later pregnancy, without exerting undue stress on maternal body systems. Here, we review normal development of a placental bed with a safe and adequate blood supply and a villous placenta-blood interface from which nutrients and oxygen can be extracted for the growing fetus. We consider disease mechanisms that are intrinsic to the maternal environment, the placenta or the interaction between the two. Systemic signalling from the endocrine placenta targets the maternal endothelium and multiple organs to adjust metabolism for an optimal pregnancy and later lactation. This signalling capacity is skewed when placental damage occurs and can deliver a dangerous pathogenic stimulus. We discuss the placental secretome including glycoproteins, microRNAs and extracellular vesicles as potential biomarkers of disease. Angiomodulatory mediators, currently the only effective biomarkers, are discussed alongside non-invasive imaging approaches to the prediction of disease risk. Identifying the signs of impending pathology early enough to intervene and ameliorate disease in later pregnancy remains a complex and challenging objective.

Microphysiological systems of the placental barrier

Methods to evaluate maternal-fetal transport across the placental barrier have generally involved clinical observations after-the-fact, ex vivo perfused placenta studies, or in vitro Transwell assays. Given the ethical and technical limitations in these approaches, and the drive to understand fetal development through the lens of transport-induced injury, such as with the examples of thalidomide and Zika Virus, efforts to develop novel approaches to study these phenomena have expanded in recent years. Notably, within the past 10 years, placental barrier models have been developed using hydrogel, bioreactor, organ-on-a-chip, and bioprinting approaches. In this review, we discuss the biology of the placental barrier and endeavors to recapitulate this barrier in vitro using these approaches. We also provide analysis of current limitations to drug discovery in this context, and end with a future outlook.

Canonical, Non-Canonical and Atypical Pathways of Nuclear Factor кb Activation in Preeclampsia

Although higher nuclear factor κB (NFκB) expression and activity is observed in preeclamptic placentas, its mechanism of activation is unknown. This is the first study to investigate whether the canonical, non-canonical, or atypical NFκB activation pathways may be responsible for the higher activation of NFκB observed in preeclamptic placentas. The study included 268 cases (130 preeclamptic women and 138 controls). We studied the expression of the genes coding for NFκB activators (NIK, IKKα, IKKβ, and CK2α) and inhibitors (IκBα and IκBβ) using RT-PCR in real time. The RT-PCR results were verified on the protein level using ELISA and Western blot. To determine the efficiency of the pathways, the ratios of activator(s) to one of the inhibitors (IκBα or IκBβ) were calculated for each studied pathway. The preeclamptic placentas demonstrated significantly lower IKKα and CK2α but higher IκBα and IκBβ protein levels. In addition, the calculated activator(s) to inhibitor (IκBα or IκBβ) ratios suggested that all studied pathways might be downregulated in preeclamptic placentas. Our results indicate that preeclamptic placentas may demonstrate mechanisms of NFκB activation other than the canonical, non-canonical, and atypical forms. In these mechanisms, inhibitors of NFκB may play a key role. These observations broaden the existing knowledge regarding the molecular background of preeclampsia development.

Effect of embryo stage at transfer on placental histopathology features in singleton live births resulting from fresh embryo transfers

OBJECTIVE

To evaluate the effect of embryo stage at transfer on placental histopathology and perinatal outcome in singleton live births resulting from fresh embryo transfers (ETs).

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

The study population included all live births after fresh ETs during the period from 2009 to 2017.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcomes included anatomic, inflammatory, vascular malperfusion, and villous maturation placental features. Secondary outcomes included fetal, maternal, and perinatal complications.

RESULT(S)

A total of 677 live births were included in the final analysis and were allocated to the cleavage-stage (n = 252) and blastocyst (n = 425) ET groups. After the adjustment for confounding factors, the blastocyst group was found to be associated with a higher incidence of circummarginate membranes insertion (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.2-3.4), delayed villous maturation (OR 8.5, 95% CI 1.2-69.3), chorangiosis (OR 2.0, 95% CI 1.2-3.8), parenchymal calcifications (OR 10.6, 95% CI 1.4-80.2), and intrapartum nonreassuring fetal heart rate tracing (OR 2.4, 95% CI 1.3-4.5). Compared with cleavage-stage ETs, live births resulting from the blastocysts were associated with a lower incidence of velamentous cord insertion (OR 0.5, 95% CI 0.3-0.9), retroplacental hematoma (OR 0.3, 95% CI 0.1-0.8), subchorionic thrombi (OR 0.3, 95% CI 0.1-0.8), and avascular villi (OR 0.2, 95% CI 0.03-0.7).

CONCLUSION(S)

Live births resulting from fresh cleavage-stage and blastocyst ETs have different placental histopathology features, with a higher rate of intrapartum nonreassuring fetal heart rate tracing in the blastocyst group.

Added prognostic value of longitudinal changes of angiogenic factors in early-onset severe pre-eclampsia: a prospective cohort study

OBJECTIVE

To assess in women with early-onset severe pre-eclampsia whether longitudinal changes in angiogenic factors improve the prediction of adverse outcome.

DESIGN

Prospective cohort study.

SETTING

Maternity units in two Spanish hospitals.

POPULATION

Women with diagnosis of early-onset severe pre-eclampsia.

METHODS

Levels of placental growth factor (PlGF), soluble fms-like tyrosine kinase (sFlt-) and sFlt-1/PlGF ratio were measured at admission and before delivery, and average daily change calculated. The association of longitudinal changes of angiogenic factors with the time interval to delivery and with complications was evaluated by logistic and Cox regression.

MAIN OUTCOME MEASURES

Interval to delivery and composite of adverse outcomes.

RESULTS

We included 63 women, of which 26 (41.3%) had a complication. Longitudinal changes of sFlt-1 were more pronounced in complicated pregnancies (median: 1047 versus 342 pg/ml/day; P = 0.04). On the multivariate analysis, the clinical risk score and sFlt-1 at admission explained 6.2% of the uncertainty for complication; the addition of sFlt-1 longitudinal changes improved this to 25.3% (P = 0.002). The median time from admission to delivery was 4 days (95% CI 1.6-6.04) in those in the highest quartile of sFlt-1 longitudinal changes versus 16 days (95% CI 12.4-19.6) in the remaining women (Log-rank test P < 0.001).

CONCLUSIONS

Longitudinal changes in sFlt-1 maternal levels from admission for confirmed early-onset severe pre-eclampsia add to baseline characteristics in the prediction of adverse outcome and interval to delivery.

TWEETABLE ABSTRACT

In early-onset severe pre-eclampsia, longitudinal changes in sFlt-1 levels improve the prediction of complications and interval to delivery.

LASP2 inhibits trophoblast cell migration and invasion in preeclampsia through inactivation of the Wnt/β-catenin signaling pathway

Preeclampsia (PE) is a specific disorder of pregnancy with significant morbidity and mortality to the mother and the fetus. It has been reported that abnormal regulation of trophoblast cells contributes to the development of PE. LIM and SH3 Protein 2 (LASP2) belongs to nebulin protein family of actin-binding protein that has broad biological functions. In this study, we evaluated the role of LASP2 in the regulation of trophoblast cells. Our results demonstrated that LASP2 was markedly up-regulated in the placentas of patients with PE. Overexpression of LASP2 significantly suppressed the cell proliferation, migration, and invasion of trophoblast cells. LASP2 overexpression reduced the expression levels of β-catenin, cyclin D1, and c-Myc in trophoblast cells. Furthermore, activation of Wnt/β-catenin pathway booked the effects of LASP2 on trophoblast cells. In conclusion, these findings indicated that LASP2 might contribute to the pathogenesis of PE via regulating cell proliferation, migration, and invasion of trophoblast cells. Thus, LASP2 might be a prospective therapeutic target for the prevention and treatment of PE.