The two-stage placental model of preeclampsia: An update

Definition and Quantification of Three-Dimensional Imaging Targets to Phenotype Pre-Eclampsia Subtypes: An Exploratory Study

Pre-eclampsia is a severe placenta-related complication of pregnancy with limited early diagnostic and therapeutic options. Aetiological knowledge is controversial, and there is no universal consensus on what constitutes the early and late phenotypes of pre-eclampsia. Phenotyping of native placental three-dimensional (3D) morphology offers a novel approach to improve our understanding of the structural placental abnormalities in pre-eclampsia. Healthy and pre-eclamptic placental tissues were imaged with multiphoton microscopy (MPM). Imaging based on inherent signal (collagen, and cytoplasm) and fluorescent staining (nuclei, and blood vessels) enabled the visualization of placental villous tissue with subcellular resolution. Images were analysed with a combination of open source (FIJI, VMTK, Stardist, MATLAB, DBSCAN), and commercially (MATLAB) available software. Trophoblast organization, 3D-villous tree structure, syncytial knots, fibrosis, and 3D-vascular networks were identified as quantifiable imaging targets. Preliminary data indicate increased syncytial knot density with characteristic elongated shape, higher occurrence of paddle-like villous sprouts, abnormal villous volume-to-surface ratio, and decreased vascular density in pre-eclampsia compared to control placentas. The preliminary data presented indicate the potential of quantifying 3D microscopic images for identifying different morphological features and phenotyping pre-eclampsia in placental villous tissue.

RISK OF PLACENTA-ASSOCIATED COMPLICATIONS AT PREECLAMPSIA IN PREGNANT WOMEN WITH THROMBOPHILIA

OBJECTIVE

The aim: To study the distribution and influence of coagulation factor gene polymorphisms, endothelial dysfunction, blood pressure regulator on the development of obstetric and perinatal complications in women with preeclampsia (PE).

PATIENTS AND METHODS

Materials and methods: The prospective cohort study included 46 women with PE and maternal or fetal complications and 87 pregnant women with PE, without complications. Genetic polymorphisms of coagulation factors and fibrinolysis (1691 G→A FVL, 20210 G→A prothrombin, 675 5G/4G PAI-1, 455 G→A fibrinogen β), endothelial dysfunction (192 Q→R PON-1, 677 C→T MTHFR) and blood pressure regulator (235 M→T angiotensinogen II) were studied with the help of allele-specific polymerase chain reaction.

RESULTS

Results: Markers of predisposition to the development of obstetric and perinatal complications in pregnant women with PE are the following genotypes: 1691 GA by V Leiden factor gene - increases the risk in 2.9 times (95% CI 1.94-4.33), 20210 GA by prothrombin gene - in 2.36 times (95% CI 1.54-3.6), 20210 AA by prothrombin gene - in 3.12 times (95% CI 2.4-4.0). Pathological polymorphisms in the genes of angiotensinogen II 235 M→T, PAI-1 5G/4G, fibrinogen β 455 G→A, paraoxonase-1 192 Q→R do not significantly affect the development of complications during preeclampsia.

CONCLUSION

Conclusions: The development of PE against the background of the existence of acquired and hereditary types of thrombophilia is associated with a more severe course, early-onset and the development of life-threatening complications for a mother and fetus.

Aspirin 75 mg to prevent preeclampsia in high-risk pregnancies: a retrospective real-world study in China

BACKGROUND

Several randomized clinical trials showed that aspirin could decrease the incidence of preeclampsia (PE) in women at high risk, but data from sources other than traditional clinical trials that investigating the preventive effect of aspirin 75 mg on PE is still lacking, especially in mainland China. We aimed to use Chinese real-world data to estimate the preventive effect of low-dose aspirin (LDA) on PE.

METHODS

Clinical data of pregnant women who were at high risk of PE and had their first prenatal visit at the affiliated Taicang People's Hospital of Soochow University during November 31, 2018 and May 10, 2021 was retrospectively analyzed. Among the 266 included pregnant women, 115 individuals treated with aspirin 75 mg per day and the other 151 without such treatment were considered as the LDA group and the control group, respectively.

RESULTS

In the LDA group, 64 (55.65%) of 115 pregnant women took aspirin before 16 weeks of gestation. Besides, 12 (10.43%) and 34 (22.52%) women developed PE in the LDA group and control group, respectively; the aspirin prophylaxis was associated with a lower risk of PE (odds ratio = 0.40, 95% confidence interval = 0.20-0.82, P = 0.0098). In addition, LDA is slightly more effective when initiated before 16 weeks of gestation or in those without chronic hypertension, when compared with their counterparts.

CONCLUSION

Prophylaxis with 75 mg per day of aspirin in high-risk women resulted in a significantly lower incidence of PE than that in the control group.

New immune horizons in therapeutics and diagnostic approaches to Preeclampsia

Hypertensive disorders of pregnancy (HDP) are one of the commonest maladies, affecting 5%-10% of pregnancies worldwide. The American College of Obstetricians and Gynecologists (ACOG) identifies four categories of HDP, namely gestational hypertension (GH), Preeclampsia (PE), chronic hypertension (CH), and CH with superimposed PE. PE is a multisystem, heterogeneous disorder that encompasses 2%-8% of all pregnancy-related complications, contributing to about 9% to 26% of maternal deaths in low-income countries and 16% in high-income countries. These translate to 50 000 maternal deaths and over 500 000 fetal deaths worldwide, therefore demanding high priority in understanding clinical presentation, screening, diagnostic criteria, and effective management. PE is accompanied by uteroplacental insufficiency leading to vascular and metabolic changes, vasoconstriction, and end-organ ischemia. PE is diagnosed after 20 weeks of pregnancy in women who were previously normotensive or hypertensive. Besides shallow trophoblast invasion and inadequate remodeling of uterine arteries, dysregulation of the nonimmune system has been the focal point in PE. This results from aberrant immune system activation and imbalanced differentiation of T cells. Further, a failure of tolerance toward the semi-allogenic fetus results due to altered distribution of Tregs such as CD4+FoxP3+ or CD4+CD25+CD127(low) FoxP3+ cells, thereby creating a cytotoxic environment by suboptimal production of immunosuppressive cytokines like IL-10, IL-4, and IL-13. Also, intracellular production of complement protein C5a may result in decreased FoxP3+ regulatory T cells. With immune system dysfunction as a major driver in PE pathogenesis, it is logical that therapeutic targeting of components of the immune system with pharmacologic agents like anti-inflammatory and immune-modulating molecules are either being used or under clinical trial. Cholesterol synthesis inhibitors like Pravastatin may improve placental perfusion in PE, while Eculizumab (monoclonal antibody inhibiting C5) and small molecular inhibitor of C5a, Zilucoplan are under investigation. Monoclonal antibody against IL-17(Secukinumab) has been proposed to alter the Th imbalance in PE. Autologous Treg therapy and immune checkpoint inhibitors like anti-CTLA-4 are emerging as new candidates in immune horizons for PE management in the future.

Circ_0004904 suppresses trophoblast cell proliferation, invasion and migration in preeclampsia via upregulating the expression of DNA damage inducible alpha by interacting with miR-19a-3p

Preeclampsia (PE) is the most common complication in the pregnancy of women. PE progression was found to be associated with dysregulated circular RNAs (circRNAs), and we aimed to explore the pathological mechanism with circ_0004904 in PE. The circ_0004904, microRNA-19a-3p (miR-19a-3p) and DNA damage inducible alpha (GADD45A) were quantified via reverse transcription-quantitative polymerase chain reaction assay. Trophoblast cell behaviors were examined by cell viability using Cell Counting Kit-8 assay, cell proliferation using EdU assay, cell apoptosis using flow cytometry, cell invasion using transwell assay and migration using wound healing assay. Western blot was used for protein analysis of epithelial mesenchymal transition (EMT) and GADD45A. Dual-luciferase reporter assay and RNA immunoprecipitation assay were used for target interaction analysis. The circ_0004904 upregulation was detected in placenta tissues from PE patients. Trophoblast cell proliferation, invasion, migration and EMT were repressed but cell apoptosis was promoted after overexpression of circ_0004904. Circ_0004904 acted as a miR-19a-3p sponge in trophoblast cells, and all regulatory effects of circ_0004904 on trophoblast cell behaviors were reversed by miR-19a-3p upregulation. The miR-19a-3p directly targeted GADD45A and miR-19a-3p downregulation inhibited trophoblast cell development through elevating the GADD45A level. Moreover, circ_0004904 enhanced the expression of GADD45A via sponging miR-19a-3p. Our results elucidated that circ_0004904 reduced proliferation and cell motility of trophoblast cells via the miR-19a-3p-mediated GADD45A level elevation, indicating the involvement of circ_0004904/miR-19a-3p/GADD45A in PE progression.

Neuro-oncological Ventral Antigen 2 Regulates Splicing of Vascular Endothelial Growth Factor Receptor 1 and Is Required for Endothelial Function

Pre-eclampsia (PE) affects 2-8% of pregnancies and is responsible for significant morbidity and mortality. The maternal clinical syndrome (defined by hypertension, proteinuria, and organ dysfunction) is the result of endothelial dysfunction. The endothelial response to increased levels of soluble FMS-like Tyrosine Kinase 1 (sFLT1) is thought to play a central role. sFLT1 is released from multiple tissues and binds VEGF with high affinity and antagonizes VEGF. Expression of soluble variants of sFLT1 is a result of alternative splicing; however, the mechanism is incompletely understood. We hypothesize that neuro-oncological ventral antigen 2 (NOVA2) contributes to this. NOVA2 was inhibited in human umbilical vein endothelial cells (HUVECs) and multiple cellular functions were assessed. NOVA2 and FLT1 expression in the placenta of PE, pregnancy-induced hypertension, and normotensive controls was measured by RT-qPCR. Loss of NOVA2 in HUVECs resulted in significantly increased levels of sFLT1, but did not affect expression of membrane-bound FLT1. NOVA2 protein was shown to directly interact with FLT1 mRNA. Loss of NOVA2 was also accompanied by impaired endothelial functions such as sprouting. We were able to restore sprouting capacity by exogenous VEGF. We did not observe statistically significant regulation of NOVA2 or sFLT1 in the placenta. However, we observed a negative correlation between sFLT1 and NOVA2 expression levels. In conclusion, NOVA2 was found to regulate FLT1 splicing in the endothelium. Loss of NOVA2 resulted in impaired endothelial function, at least partially dependent on VEGF. In PE patients, we observed a negative correlation between NOVA2 and sFLT1.

TMBIM4 Deficiency Facilitates NLRP3 Inflammasome Activation-Induced Pyroptosis of Trophoblasts: A Potential Pathogenesis of Preeclampsia

Impaired invasion of EVTs results in inadequate remodelling of arteries and poor placentation, leading to PE. TMBIM4 was found to promote the migration and invasion of human osteosarcoma U2-OS and breast cancer MCF7 cell lines. However, the effect of TMBIM4 on trophoblast biological behaviour and its relevance to PE pathophysiology remain unclear. In this study, we confirmed that TMBIM4 was highly expressed in cytotrophoblasts, syncytiotrophoblasts, and EVTs of the human placenta during early pregnancy. By comparing the expression levels of TMBIM4 in the placenta of women with normal-term pregnancy and PE, TMBIM4 was found to be significantly decreased in PE. Thereafter, we determined the expression of TMBIM4 in the LPS-treated first-trimester human trophoblast cell line HTR-8/SVneo (mimicking a PE-like cell model), and determined the effect of TMBIM4 on trophoblast function and its underlying mechanism. LPS treatment reduced the expression of TMBIM4 and induced NLRP3 inflammasome activity in HTR-8/SVneo cells. KO of TMBIM4 in the HTR-8/SVneo cell line impaired cell viability, migration, and invasion, which was more severe in the LPS/ATP-treated TMBIM4-KO cell line. Moreover, TMBIM4 deficiency enhanced NLRP3 inflammasome activity and promoted subsequent pyroptosis, with or without LPS/ATP treatment. The negative relationship between TMBIM4 expression and NLRP3 inflammatory activity was verified in PE placentas. Inhibiting the NLRP3 inflammasome with MCC950 in HTR-8/SVneo cells alleviated LPS/ATP-induced pyroptosis and damaged cell function in the TMBIM4-KO cell line. Overall, this study revealed a new PE-associated protein, TMBIM4, and its biological significance in trophoblast pyroptosis mediated by the NLRP3 inflammasome. TMBIM4 may serve as a potential target for the treatment of placental inflammation-associated PE.

Metabolic profiling of pregnancies complicated by preeclampsia: A longitudinal study

INTRODUCTION

Preeclampsia is associated with maternal metabolic disturbances, but longitudinal studies with comprehensive metabolic profiling are lacking. We aimed to determine metabolic profiles across gestation in women who developed preeclampsia compared with women with healthy pregnancies. We also explored the respective effects of body mass index (BMI) and preeclampsia on various metabolic measures.

MATERIAL AND METHODS

We measured 91 metabolites by high-throughput nuclear magnetic resonance spectroscopy at four time points (visits) during pregnancy (weeks 14-16, 22-24, 30-32 and 36-38). Samples were taken from a Norwegian pregnancy cohort. We fitted a linear regression model for each metabolic measure to compare women who developed preeclampsia (n = 38) and healthy controls (n = 70).

RESULTS

Among women who developed preeclampsia, 92% gave birth after 34 weeks of gestation. Compared to women with healthy pregnancies, women who developed preeclampsia had higher levels of several lipid-related metabolites at visit 1, whereas fewer differences were observed at visit 2. At visit 3, the pattern from visit 1 reappeared. At visit 4 the differences were larger in most subgroups of very-low-density lipoprotein particles, the smallest high-density lipoprotein, total lipids and triglycerides. Total fatty acids were also increased, of which monounsaturated fatty acids and saturated fatty acids showed more pronounced differences. Concentration of glycine tended to be lower in pregnancies with preeclampsia until visit 3, although this was not significant after correction for multiple testing. After adjustment for age, BMI, parity and gestational weight gain, all significant differences were attenuated at visits 1 and 2. The estimates were less affected by adjustment at visits 3 and 4.

CONCLUSIONS

In early pregnancy, the metabolic differences between preeclamptic and healthy pregnancies were primarily driven by maternal BMI, probably representing the women's pre-pregnancy metabolic status. In early third trimester, several weeks before clinical manifestation, the differences were less influenced by BMI, indicating preeclampsia-specific changes. Near term, women with preeclampsia developed an atherogenic metabolic profile, including elevated total lipids, very-low-density lipoprotein, triglycerides, and total fatty acids.

Effects of Salvia miltiorrhiza active compounds on placenta-mediated pregnancy complications

Placenta-mediated pregnancy complications (PMPCs), including preeclampsia (PE), fetal growth restriction (FGR), and recurrent spontaneous abortion (RSA), occur in approximately 5% of pregnancies and are caused by abnormal placenta development. The development of effective therapies for PMPCs is still challenging due to the complicated pathogenesis, such as disrupted vascular homeostasis and subsequent abnormal placentation. Synthetic drugs have been recommended for treating PMPCs; however, they tend to cause adverse reactions in the mother and fetus. Salvia miltiorrhiza (S. miltiorrhiza) has potential effects on PMPCs owing to its advantages in treating cardiovascular disorders. S. miltiorrhiza and its active compounds could attenuate the symptoms of PMPCs through anticoagulation, vasodilation, antioxidation, and endothelial protection. Thus, in this review, we summarize the literature and provide comprehensive insights on S. miltiorrhiza and its phytochemical constituents, pharmacological activities, and on PMPCs, which would be valuable to explore promising drugs.

Integrated Proteomic and N-Glycoproteomic Profiling of Placental Tissues of Patients with Preeclampsia

Background

Preeclampsia (PE) is a multi-system disorder of pregnancy that poses a serious threat to maternal and perinatal health worldwide. This study aims to evaluate the global alterations of protein expression and N-glycosylations that are crucial for PE pathogenesis. Here, tandem mass tag labeling combined with LC-MS/MS was employed to determine the global expression of all proteins and intact glycopeptide in placentas from three healthy pregnant women, three patients with early-onset severe PE, and three patients with late-onset severe PE.

Results

A total of 2260 proteins were quantified across 9 placental tissues, of which 37 and 23 were differentially expressed in the early-onset and late-onset PE groups, compared to the controls. A total of 789 glycopeptides were accurately quantified, which were derived from 204 glycosylated sites in 159 glycoproteins and were modified by 59 N-Linked glycans. A total of 123 differently expressed glycopeptides, which were from 47 glycoproteins were identified among three groups. Through a combined analysis of proteomic and glycoproteomic data, it was found that the changes in 10 glycoproteins were caused by the difference in glycosylation level but not in the protein abundance level.

Conclusion

This is the first study to conduct an integrated proteomic and glycoproteomic characterization of placental tissues of PE patients. Our findings suggest that glycosylation modification may affect the molecular function of proteins through changes in the glycosylation structure or the occupancy of glycosylation, which will provide new insights to help elucidating the pathogenic mechanism of PE.

Prevalence of pre-eclampsia and adverse pregnancy outcomes in women with pre-existing cardiomyopathy: a multi-centre retrospective cohort study

Pre-eclampsia is associated with postnatal cardiac dysfunction; however, the nature of this relationship remains uncertain. This multicentre retrospective cohort study aimed to determine the prevalence of pre-eclampsia in women with pre-existing cardiac dysfunction (left ventricular ejection fraction < 55%) and explore the relationship between pregnancy outcome and pre-pregnancy cardiac phenotype. In this cohort of 282 pregnancies, pre-eclampsia prevalence was not significantly increased (4.6% [95% C.I 2.2-7.0%] vs. population prevalence of 4.6% [95% C.I. 2.7-8.2], p = 0.99); 12/13 women had concurrent obstetric/medical risk factors for pre-eclampsia. The prevalence of preterm pre-eclampsia (< 37 weeks) and fetal growth restriction (FGR) was increased (1.8% vs. 0.7%, p = 0.03; 15.2% vs. 5.5%, p < 0.001, respectively). Neither systolic nor diastolic function correlated with pregnancy outcome. Antenatal ß blockers (n = 116) were associated with lower birthweight Z score (adjusted difference - 0.31 [95% C.I. - 0.61 to - 0.01], p = 0.04). To conclude, this study demonstrated a modest increase in preterm pre-eclampsia and significant increase in FGR in women with pre-existing cardiac dysfunction. Our results do not necessarily support a causal relationship between cardiac dysfunction and pre-eclampsia, especially given the population's background risk status. The mechanism underpinning the relationship between cardiac dysfunction and FGR merits further research but could be influenced by concomitant ß blocker use.

Versican provides the provisional matrix for uterine spiral artery dilation and fetal growth

The extracellular matrix (ECM) in the endometrium plays a crucial role in mammalian pregnancy. We have shown that versican secreted from the endometrial epithelium promotes embryo implantation. Versican is a proteoglycan, a major player in the provisional matrix, and versikine, its N-terminal fragment cleaved by ADAMTS proteinases, serves as a bioactive molecule. Here, since versican expression in the placenta was dynamically altered in humans and mice, we investigated the role of versican in pregnancy using uterine-specific Vcan deletion mice (uKO mice) and ADAMTS-resistant versican expressing mice (V1R mice). uKO mice exhibited insufficient spiral artery dilation, followed by fetal growth restriction and maternal hypertension. Further analysis revealed impaired proliferation of tissue-resident natural killer cells required for spiral artery dilation. V1R mice showed the same results as the control, eliminating the involvement of versikine. Our results provide a new concept that versican, one factor of ECM, contributes to placentation and following fetal growth.

Pathophysiology of Preeclampsia and L-Arginine/L-Citrulline Supplementation as a Potential Strategy to Improve Birth Outcomes

In preeclampsia, the shallow invasion of cytotrophoblast cells to uterine spiral arteries, leading to a reduction in placental blood flow, is associated with an imbalance of proangiogenic/antiangiogenic factors to impaired nitric oxide (NO) production. Proangiogenic factors, such as vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), require NO to induce angiogenesis through antioxidant regulation mechanisms. At the same time, there are increases in antiangiogenic factors in preeclampsia, such as soluble fms-like tyrosine kinase type 1 receptor (sFIt1) and toll-like receptor 9 (TLR9), which are mechanism derivates in the reduction of NO bioavailability and oxidative stress in placenta.Different strategies have been proposed to prevent or alleviate the detrimental effects of preeclampsia. However, the only intervention to avoid the severe consequences of the disease is the interruption of pregnancy. In this scenario, different approaches have been analysed to treat preeclamptic pregnant women safely. The supplementation with amino acids is one of them, especially those associated with NO synthesis. In this review, we discuss emerging concepts in the pathogenesis of preeclampsia to highlight L-arginine and L-citrulline supplementation as potential strategies to improve birth outcomes. Clinical and experimental data concerning L-arginine and L-citrulline supplementation have shown benefits in improving NO availability in the placenta and uterine-placental circulation, prolonging pregnancy in patients with gestational hypertension and decreasing maternal blood pressure.

COVID-19 and pregnancy: clinical outcomes; mechanisms, and vaccine efficacy

As the COVID-19 pandemic continues into its third year, emerging data indicates increased risks associated with SARS-CoV-2 infection during pregnancy, including pre-eclampsia, intrauterine growth restriction, preterm birth, stillbirth, and risk of developmental defects in neonates. Here, we review clinical reports to date that address different COVID-19 pregnancy complications. We also document placental pathologies induced by SARS-CoV-2 infection, entry mechanisms in placental cells, and immune responses at the maternal-fetal interface. Since new variants of SARS-CoV-2 are emerging with characteristics of higher transmissibility and more effective immune escape strategies, we also briefly highlight the genomic and proteomic features of SARS-CoV-2 investigated to date. Vector and mRNA-based COVID-19 vaccines continue to be rolled out globally. However, because pregnant individuals were not included in the vaccine clinical trials, some pregnant individuals have safety concerns and are hesitant to take these vaccines. We describe the recent studies that have addressed the effectiveness and safety of the current vaccines during pregnancy. This review also sheds light on important areas that need to be carefully or more fully considered with respect to understanding SARS-CoV-2 disease mechanisms of concern during pregnancy.

Epigenetic clocks and female fertility timeline: A new approach to an old issue?

Worldwide increase in life expectancy has boosted research on aging. Overcoming the concept of chronological age, higher attention has been addressed to biological age, which reflects a person's real health state, and which may be the resulting combination of both intrinsic and environmental factors. As epigenetics may exert a pivotal role in the biological aging, epigenetic clocks were developed. They are based on mathematical models aimed at identifying DNA methylation patterns that can define the biological age and that can be adopted for different clinical scopes (i.e., estimation of the risks of developing age-related disorders or predicting lifespan). Recently, epigenetic clocks have gained a peculiar attention in the fertility research field, in particular in the female counterpart. The insight into the possible relations between epigenetic aging and women's infertility might glean additional information about certain conditions that are still not completely understood. Moreover, they could disclose significant implications for health promotion programs in infertile women. Of relevance here is that the impact of biological age and epigenetics may not be limited to fertility status but could translate into pregnancy issues. Indeed, epigenetic alterations of the mother may transfer into the offspring, and pregnancy itself as well as related complications could contribute to epigenetic modifications in both the mother and newborn. However, even if the growing interest has culminated in the conspicuous production of studies on these topics, a global overview and the availability of validated instruments for diagnosis is still missing. The present narrative review aims to explore the possible bonds between epigenetic aging and fertility timeline. In the "infertility" section, we will discuss the advances on epigenetic clocks focusing on the different tissues examined (endometrium, peripheral blood, ovaries). In the "pregnancy" section, we will discuss the results obtained from placenta, umbilical cord and peripheral blood. The possible role of epigenetic aging on infertility mechanisms and pregnancy outcomes represents a question that may configure epigenetic clock as a bond between two apparently opposite worlds: infertility and pregnancy.

Preeclampsia and syncytiotrophoblast membrane extracellular vesicles (STB-EVs)

Preeclampsia (PE) is a hypertensive complication of pregnancy that affects 2-8% of women worldwide and is one of the leading causes of maternal deaths and premature birth. PE can occur early in pregnancy (<34 weeks gestation) or late in pregnancy (>34 weeks gestation). Whilst the placenta is clearly implicated in early onset PE (EOPE), late onset PE (LOPE) is less clear with some believing the disease is entirely maternal whilst others believe that there is an interplay between maternal systems and the placenta. In both types of PE, the syncytiotrophoblast (STB), the layer of the placenta in direct contact with maternal blood, is stressed. In EOPE, the STB is oxidatively stressed in early pregnancy (leading to PE later in gestation- the two-stage model) whilst in LOPE the STB is stressed because of villous overcrowding and senescence later in pregnancy. It is this stress that perturbs maternal systems leading to the clinical manifestations of PE. Whilst some of the molecular species driving this stress have been identified, none completely explain the multisystem nature of PE. Syncytiotrophoblast membrane vesicles (STB-EVs) are a potential contributor to this multisystem disorder. STB-EVs are released into the maternal circulation in increasing amounts with advancing gestational age, and this release is further exacerbated with stress. There are good in vitro evidence that STB-EVs are taken up by macrophages and liver cells with additional evidence supporting endothelial cell uptake. STB-EV targeting remains in the early stages of discovery. In this review, we highlight the role of STB-EVs in PE. In relation to current research, we discuss different protocols for ex vivo isolation of STB-EVs, as well as specific issues involving tissue preparation, isolation (some of which may be unique to STB-EVs), and methods for their analysis. We suggest potential solutions for these challenges.

Role of clusterin in predicting development of early- and late-onset preeclampsia in the first trimester of pregnancy

Preeclampsia (PE) occurs in 2–8% of pregnancies. It is one of the leading causes of maternal and perinatal morbidity and mortality. Today, there are no tests adopted by the practitioners that enable accurate prediction of early (weeks 20 through 34) or late (after week 34) onset of PE when the pregnancy is in its 11th to 14th week. This study aimed to evaluate the feasibility of using secretory clusterin quantification to predict early or late PE during the first trimester of pregnancy. The choice of this protein is determined, on the one hand, by the specificity of its expression for cytotrophoblast, syncytiotrophoblast, and extracellular trophoblast cells, and, on the other hand, by the proven negative effect of clusterin on the invasive properties of trophoblastic cells and gestational transformations of uterine vessels, which play a key role in the pathogenesis of PE. The study included 40 pregnant women aged 27–40 years who underwent a comprehensive screening examination in the first trimester of pregnancy. Western blotting revealed a significant increase in the level of secretory clusterin (40 kDa) in the blood serum of pregnant women in the case of PE compared to physiological pregnancy: in early-onset PE, a twofold increase in the level of clusterin in the vesicular and extravesicular fractions of blood serum (p = 0.03 and p = 0.004, respectively), with late-onset PE — a threefold increase only in the extravesicular fraction of blood serum (p = 0.002). According to logistic regression models, the level of secretory clusterin in the extravesicular fraction of blood serum of pregnant women in the first trimester has prognostic significance in assessing the likelihood of developing early-onset PE (AUC = 0.97, Se = 1, Sp = 0.875, cutoff = 0.3877) and late-onset PE ( AUC = 1, Se = 1, Sp = 1, cutoff = 0.5).

The Potential for Placental Activation of PPARγ to Improve the Angiogenic Profile in Preeclampsia

Preeclampsia (PE) is one of the most common causes of maternal-fetal morbidity and mortality world-wide. While the underlying causes of PE remain elusive, aberrant trophoblast differentiation and function are thought to cause an imbalance of secreted angiogenic proteins resulting in systemic endothelial dysfunction and organ damage in the mother. The placental dysfunction is also characterized by a reduction of the transcription factor, peroxisome proliferator activated receptor γ (PPARγ) which normally promotes trophoblast differentiation and healthy placental function. This study aimed to understand how placental activation of PPARγ effects the secretion of angiogenic proteins and subsequently endothelial function. To study this, healthy and PE placental tissues were cultured with or without the PPARγ agonist, Rosiglitazone, and a Luminex assay was performed to measure secreted proteins from the placenta. To assess the angiogenic effects of placental activation of PPARγ, human umbilical vein endothelial cells (HUVECs) were cultured with the placental conditioned media and the net angiogenic potential of these cells was measured by a tube formation assay. This is the first study to show PPARγ's beneficial effect on the angiogenic profile in the human preeclamptic placenta through the reduction of anti-angiogenic angiopoietin-2 and soluble endoglin and the upregulation of pro-angiogenic placental growth factor, fibroblast growth factor-2, heparin-binding epidermal growth factor, and follistatin. The changes in the angiogenic profile were supported by the increased angiogenic potential observed in the HUVECs when cultured with conditioned media from rosiglitazone-treated preeclamptic placentas. The restoration of these disrupted pathways by activation of PPARγ in the preeclamptic placenta offers potential to improve placental and endothelial function in PE.

Decrease in Nitric Oxide Production as a Key Mediator in the Pathogenesis of Preeclampsia and a Potential Therapeutic Target: A Case-Control Study

Pregnancy-induced hypertension (GH) complicates 6−10% of all pregnancies and, in 2019, was responsible for approximately 28,000 deaths. The most common cause of gestational hypertension is pre-eclampsia (PE), which afflicts 2−8% of all pregnancies and is one of the three leading causes of maternal morbidity and mortality worldwide. The aim of this study was to clarify how NO metabolism changes during the course of PE. Due to the short half-life of NO, we measured the concentrations of its stable metabolites, nitrite and nitrate (NOx). Out of 100 enrolled patients: 58 pregnant women with a diagnosed early form of PE formed a study group, and 42 healthy pregnant women formed a control group. NOx concentrations were significantly lower in the PE group than in the control group, with mean values of 5.33 and 27.64 μmol/L, respectively (p < 0.0001). The decrease in NO is most likely the result and mediator of systemic endothelial dysfunction. The impairment of NO metabolism in PE appears to play an important role in its pathogenesis. Therefore, it is a potential therapeutic target.

Molecular Mechanisms Underlying Twin-to-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome is a unique disease and a serious complication occurring in 10–15% of monochorionic multiple pregnancies with various placental complications, including hypoxia, anemia, increased oxidative stress, and ischemia-reperfusion injury. Fetoscopic laser photocoagulation, a minimally invasive surgical procedure, seals the placental vascular anastomoses between twins and dramatically improves the survival rates in twin-to-twin transfusion syndrome. However, fetal demise still occurs, suggesting the presence of causes other than placental vascular anastomoses. Placental insufficiency is considered as the main cause of fetal demise in such cases; however, little is known about its underlying molecular mechanisms. Indeed, the further association of the pathogenic mechanisms involved in twin-to-twin transfusion syndrome placenta with several molecules and pathways, such as vascular endothelial growth factor and the renin–angiotensin system, makes it difficult to understand the underlying pathological conditions. Currently, there are no effective strategies focusing on these mechanisms in clinical practice. Certain types of cell death due to oxidative stress might be occurring in the placenta, and elucidation of the molecular mechanism underlying this cell death can help manage and prevent it. This review reports on the molecular mechanisms underlying the development of twin-to-twin transfusion syndrome for effective management and prevention of fetal demise after fetoscopic laser photocoagulation.

Prevalence, maternal characteristics, and birth outcomes of preeclampsia: A cross-sectional study in a single tertiary healthcare center in greater Kuala Lumpur Malaysia

Background

Preeclampsia is associated with an increased risk of adverse maternal and perinatal outcomes. This study aimed to assess preeclampsia prevalence in a Malaysian referral maternity hospital and the association between preeclampsia and maternal characteristics and outcomes.

Methods

A cross-sectional study was conducted between January 2010 and December 2020 using secondary data from a single tertiary healthcare center in Greater Kuala Lumpur, Malaysia. A total of 40,212 deliveries were included for analysis to investigate the association between conditions (maternal characteristics and adverse birth outcomes) and preeclampsia. Multivariable logistic regression was conducted to assess the association between multiple independent variables and the outcome variable (preeclampsia).

Results

The reported prevalence of preeclampsia was 1.6%. Pregnant women with preeclampsia had a higher risk of preterm delivery (67.7%), instrumental and cesarean delivery (74.7%), neonatal low birth weight (48.5%), neonatal 5-min Apgar score <7 (18.1%), and neonatal intensive care unit (NICU) admission (19.8%). There were significantly higher odds of developing preeclampsia among nullipara [adjusted odd ratio (adjOR) 1.792, 95% CI: 1.518-2.115], women with a previous history of preeclampsia (adjOR 5.345, 95% CI: 2.670-10.698) and women with multiple pregnancies (adjOR 1.658, 95% CI: 1.071-2.566). However, there is a significant association between maternal characteristic variables. There was a significant association when a combination of variables for risk assessment: the presence of anemia and gestational hypertension effect on preeclampsia (OR 26.344, 95% CI: 9.775-70.993, p < 0.002) and gestational hypertension without anemia on preeclampsia (OR 3.084, 95% CI: 2.240-4.245, p < 0.001). Similarly, an association was seen between chronic hypertension and younger age (<35 years old) on preeclampsia (OR 14.490, 95% CI: 9.988-21.021, p < 0.001), and having chronic hypertension with advanced maternal age (≥35 years old) on preeclampsia (OR 5.174, 95% CI: 3.267-8.195, p < 0.001). Both conditions had increased odds of preeclampsia, in varying magnitudes. Overall, the significant interaction effects suggest that a history of chronic or gestational hypertension has a different relationship to the incidence of preeclampsia depending on the maternal age and anemia status. Pregnant women with preeclampsia had significantly higher odds for preterm delivery (adjOR 6.214, 95% CI: 5.244-7.364), instrumental and cesarean delivery (adjOR 4.320, 95% CI: 3.587-5.202), neonatal low birth weight (adjOR 7.873, 95% CI: 6.687-9.271), 5-min Apgar score <7 (adjOR 3.158, 95% CI: 2.130-4.683), and NICU admission (adjOR 8.778, 95% CI: 7.115-10.830).

Conclusions

Nulliparity, previous history of preeclampsia, and multiple pregnancies were associated with an increased risk of preeclampsia. The presence of different underlying conditions, such as chronic hypertension, anemia, and extremes of maternal age played an important role in increasing preeclampsia risk in the considered study. Larger samples are needed to validate such findings.

Emerging pharmacologic interventions for pre-eclampsia treatment

INTRODUCTION

Pre-eclampsia is a serious pregnancy complication and a major global concern for the mortality of both mother and fetus. Existing symptomatic treatments do not delay disease progression; thus, timely delivery of the baby is the most effective measure. However, the risk of various maternal and fetal injuries remains.

AREAS COVERED

In this review, we summarize the potential strategies for pharmacologic interventions in pre-eclamptic therapy. Specifically, we discuss the pathophysiological process of various effective candidate therapeutics that act on potential pathways and molecular targets to inhibit key stages of the disease. We refer to this pathogenesis-focused drug discovery model as a pathogenesis-target-drug (P-T-D) strategy. Finally, we discuss the introduction of nanotechnologies to improve the safety and efficacy of therapeutics via their specific placental targeting ability and placental retention effects.

EXPERT OPINION

Despite the active development of novel pharmacological treatments based on our current knowledge of pre-eclamptic pathogenesis, investigations are still in the early phase. Thus, further exploration of the pathological mechanisms, integrated with the P-T-D strategy and novel nanosystems, could encourage the development of more effective and safer strategies. Such advances could lead to a shift from expectant management to mechanistic-based therapy for pre-eclampsia.

Use of antihistamines before or during pregnancy and risk of early-onset pre-eclampsia in allergic women: a population-based cohort study

OBJECTIVE

We have previously found that allergy is a risk factor for early-onset pre-eclampsia. The aim of this study was to assess the association between pregestational maternal use of antihistamines and early-onset pre-eclampsia.

DESIGN

A population-based cohort study.

SETTING AND PARTICIPANTS

All women giving birth in Norway 2004-2016, including 692 487 pregnancies. Data from the Medical Birth Registry of Norway were linked with data from the Norwegian Prescription Database. Prescriptions of antihistamines were divided into three groups: before pregnancy (<6 months), early pregnancy (<20 weeks) and late pregnancy (20-36 weeks). ORs with 95% CIs for pre-eclampsia <34 and <37 weeks by antihistamine use were estimated by logistic regression and stratified on multiple pregnancy and parity. Predicted proportions (%) with 95% CIs were estimated.

INTERVENTIONS

Use of antihistamines in relation to pregnancy in allergic women.

MAIN OUTCOME MEASURES

Development of early-onset pre-eclampsia.

RESULTS

2997 (0.43%) and 5769 (0.83%) women had pre-eclampsia <34 and <37 weeks, respectively. Use of antihistamines before and in early pregnancy was associated with a risk of developing early-onset pre-eclampsia that was comparable to the background population (OR 1.0, 95% CI 0.8 to 1.2 and OR 0.9, 95% CI 0.7 to 1.1, respectively). Antihistamine use only in late pregnancy was not treated as exposure, but as an indicator of allergy, and was associated with an increased risk of early-onset pre-eclampsia (OR 1.8, 95% CI 1.5 to 2.2). Predicted proportions of pre-eclampsia <34 weeks were significantly lower in women using antihistamines before (0.41%, 95% CI 0.34 to 0.49) and in early pregnancy (0.37%, 95% CI 0.31 to 0.44), compared with women using antihistamines after placentation (0.69%, 95% CI 0.57 to 0.83). Results were similar for pre-eclampsia <37 weeks.

CONCLUSIONS

Antihistamine use before or during placentation was associated with reduced risk of developing early-onset pre-eclampsia in allergic women compared with women using antihistamines after placentation.

Role of microRNAs in trophoblast invasion and spiral artery remodeling: Implications for preeclampsia

It is now well-established that microRNAs (miRNAs) are important regulators of gene expression. The role of miRNAs in placental development and trophoblast function is constantly expanding. Trophoblast invasion and their ability to remodel uterine spiral arteries are essential for proper placental development and successful pregnancy outcome. Many miRNAs are reported to be dysregulated in pregnancy complications, especially preeclampsia and they exert various regulatory effects on trophoblasts. In this review, we provide a brief overview of miRNA biogenesis and their mechanism of action, as well as of trophoblasts differentiation, invasion and spiral artery remodeling. We then discuss the role of miRNAs in trophoblasts invasion and spiral artery remodeling, focusing on miRNAs that have been thoroughly investigated, especially using multiple model systems. We also discuss the potential role of miRNAs in the pathogenesis of preeclampsia.

DCAF13 is essential for the pathogenesis of preeclampsia through its involvement in endometrial decidualization

Preeclampsia (PE) is a syndrome that occurs during pregnancy and affects more than 8 million mother-infant pairs each year. Most previous studies on the pathogenesis of PE have focused on the placenta. However, decidualization is the basis for placentation and subsequent development. The CRL4 (Cullin 4-RING E3 ubiquitin ligase) complex ubiquitinates and degrades substrates, while DCAF13 (DDB1 and CUL4-associated factor 13) is a component and substrate receptor of this complex, which recognizes and recruits the complex different substrates. DCAF13 plays a major role in the maintenance of follicles and the development of oocytes. However, its role in subsequent pregnancies remains unclear. In the present study, we first investigated DCAF13 levels in the decidua of PE patients and found that it is significantly lower than that of normal pregnant women. Second, we found that DCAF13 expression increases during decidualization, and reducing expression of DCAF13 by siRNA prevents decidualization. Third, in vivo experiments in mice further revealed that Dcaf13 expression increases with decidualization. Finally, we generated and found that uteri of pseudopregnant conditional Dcaf13 knockout mice fails to undergo decidualization. Therefore, we propose that DCAF13 plays a key role in decidualization. Abnormal expression of DCAF13 affects the decidualization process, which is likely involved in the occurrence and development of PE.

Elevated trophoblastic Siglec6 contributes to the impairment of vascular endothelial cell functions by downregulating Wnt6/β-catenin signaling in preeclampsia

Preeclampsia (PE), a systemic vascular disorder, is the leading cause of maternal and perinatal morbidity and mortality, and its pathogenesis has yet to be fully elucidated. Siglec6, a transmembrane protein, is highly expressed in human placental trophoblasts, and previous studies have shown that Siglec6 overexpression correlates with PE, but the role of Siglec6 during PE progression is unknown. Here, we demonstrated that the mRNA and protein expression levels of Siglec6 were upregulated in early-onset PE placentas compared with uncomplicated pregnancies, and Siglec6 was primarily located in syncytiotrophoblasts (STBs) and extravillous trophoblasts (EVTs). Moreover, our results showed that chemical reagent-induced HIF-1α accumulation promoted the mRNA and protein levels of Siglec6 in HTR8/SVneo and BeWo cells. Although Siglec6 overexpression did not affect HTR8/SVneo cell proliferation, migration, and invasion, the conditional medium derived from the Siglec6 overexpressed HTR8/SVneo cells (Siglec6-OE-CM) significantly impaired the proliferation, migration, invasion, and tube formation of human umbilical vein endothelial cells (HUVECs). Subsequently, the transcriptome sequencing results revealed that Siglec6 overexpression led to the downregulation of Wnt6 in HTR8/SVneo cells, which was further confirmed by qPCR and ELISA. Recombinant human Wnt6 reversed Siglec6-OE-CM-mediated suppression of HUVEC functions by reactivating the Wnt/β-catenin signaling pathway. Altogether, our study found that elevated trophoblastic Siglec6 contributed to the impairment of vascular endothelial cell functions by downregulating Wnt6/β-catenin signaling.

Prevention of intrauterine fetal growth restriction by administrating C1q/TNF-related protein 6, a specific inhibitor of the alternative complement pathway

PURPOSE

The latest treatments do not sufficiently prevent miscarriage and fetal growth restriction (FGR) in pregnant women. Here, we assessed the effects of a human protein, CTRP6, that specifically inhibits the activation of the alternative complement pathway on miscarriage, fetal and placental development.

METHODS

Pregnant CBA/J mice mated with DBA/2 male mice as a model of spontaneous abortion and FGR were randomly divided into the control and CTRP6 groups. In the CTRP6 group, the mice were intravenously administered CTRP6 on days 4.5 and 6.5 post-conception (dpc). The abortion rate and fetal and placental weights on 14.5 dpc were examined. Remodeling of the spiral artery was also assessed.

RESULTS

The abortion rate in the CTRP6 group (13%) was reduced compared to the control group (21%), but there was no statistical difference. The placental and fetal weights in the CTRP6 group were also heavier than those in the control (P < 0.05). Moreover, the thickness of the blood vessel wall in the CTRP6 group was significantly thinner than that in the control (P < 0.05) and comparable to that in the non-abortion model (CBA/J x BALB). The ratio of the inner-per-the-outer diameter of the spiral artery increased more in the CTRP6 group than that in the control (P < 0.05). As well, the Th1/Th2 cytokine ratio was significantly reduced by CTRP6 treatment.

CONCLUSIONS

Taken together, the supplementation with a protein that regulates the alternative complement pathway in vivo improves FGR and promotes spiral artery remodeling in a mouse model of miscarriage and FGR.

Neonatal outcomes of twins &lt;29 weeks gestation of mothers with hypertensive disorders of pregnancy

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are associated with dysfunctional placentation and are a major cause of maternal and neonatal morbidity and mortality. Twin pregnancies have a larger placental mass and are a risk factor for HDP. The effect of HDP on neonatal outcomes in twin pregnancies is unknown.

METHODS

Retrospective cohort study using the Canadian Neonatal Network database from 2010-2018 of twin infants &lt;29 weeks gestation born to mothers with HDP and normotensive pregnancies. Using multivariable models, we determined adjusted odds ratios (AORs) and 95% confidence intervals (CI) for mortality, bronchopulmonary dysplasia, severe neurologic injury, severe retinopathy of prematurity (ROP), necrotizing enterocolitis, and nosocomial infection in twin infants of mothers with HDP compared to twin infants of normotensive mothers.

RESULTS

Of the 2414 eligible twin infants &lt;29 weeks gestational age, 164 (6.8%) were born to mothers with HDP and had higher odds of severe ROP (AOR 2.48, 95% CI 1.34-4.59). Preterm twin infants born to mothers with HDP also had higher odds of mortality (AOR 2.02, 95% CI 1.23-3.32). There was no difference in other outcomes.

CONCLUSION

Preterm twin infants &lt;29 weeks gestation of HDP mothers have higher odds of severe ROP and mortality.

IMPACT

Hypertensive disorders of pregnancy, associated with placental dysfunction, are a major cause of maternal and neonatal morbidity and mortality. Twin pregnancy, associated with a larger placental mass, is a risk factor for hypertensive disorders of pregnancy. The effect of hypertensive disorders of pregnancy on outcomes of preterm twins is unknown. Preterm twins of mothers with hypertensive disorders of pregnancy are at higher risk of severe retinopathy of prematurity and mortality. Our data can be used to counsel parents and identify infants at higher risk of severe retinopathy of prematurity and mortality.

Oxidative and Inflammatory Imbalance in Placenta and Kidney of sFlt1-Induced Early-Onset Preeclampsia Rat Model

Preeclampsia (PE) is a pregnancy-specific disorder characterized by the new onset of hypertension plus proteinuria and/or end-organ dysfunction. Here, we investigate the role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system as a major component of reactive oxygen species generation, in a rodent model of early-onset preeclampsia induced by excess sFlt1 (soluble fms-like tyrosine kinase 1). Placenta and kidney samples were obtained from normal pregnant and PE rats to measure the sFlt1/PlGF (placental growth factor) ratio in addition to oxidative stress-related parameters, including the activities and expressions of NADPH oxidase isoforms (NOX1, NOX2, and NOX4), components of nitric oxide (NO) metabolism, and antioxidant enzymes. Peroxisome proliferator-activated receptors (PPARα, PPARγ) and cytokines IL1β, IL3, IL6, IL10, and IL18 were also measured to evaluate the inflammation status in our experimental setting. Excessive O₂^●− production was found in rats that were treated with sFlt1; interestingly, this alteration appears to be mediated mainly by NOX2 in the placenta and by NOX4 in the kidney. Altered NO metabolism and antioxidant defense systems, together with mitochondrial dysfunction, were observed in this model of PE. Preeclamptic animals also exhibited overexpression of proinflammatory biomarkers as well as increased collagen deposition. Our results highlight the role of NADPH oxidase in mediating oxidative stress and possibly inflammatory processes in the placenta and kidney of an sFlt1-based model of early-onset preeclampsia.

Blood biomarkers representing maternal-fetal interface tissues used to predict early-and late-onset preeclampsia but not COVID-19 infection

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Endothelial dysfunction misleads blood marker discovery by differential expression.

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Blood-derived surrogate transcriptome of target-tissue avoids the false discovery.

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ITGA5 implies polymicrobial infection of maternal-fetal interface in preeclampsia.

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ITGA5 and IRF6 implies viral co-infection in early-onset preeclampsia.

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ITGA5, IRF6, and P2RX7 differ imminent preeclampsia from COVID-19 infection.

Background

A well-known blood biomarker (soluble fms-like tyrosinase-1 [sFLT-1]) for preeclampsia, i.e., a pregnancy disorder, was found to predict severe COVID-19, including in males. True biomarker may be masked by more-abrupt changes related to endothelial instead of placental dysfunction. This study aimed to identify blood biomarkers that represent maternal-fetal interface tissues for predicting preeclampsia but not COVID-19 infection.

Methods

The surrogate transcriptome of tissues was determined by that in maternal blood, utilizing four datasets (n = 1354) which were collected before the COVID-19 pandemic. Applying machine learning, a preeclampsia prediction model was chosen between those using blood transcriptome (differentially expressed genes [DEGs]) and the blood-derived surrogate for tissues. We selected the best predictive model by the area under the receiver operating characteristic (AUROC) using a dataset for developing the model, and well-replicated in datasets both with and without an intervention. To identify eligible blood biomarkers that predicted any-onset preeclampsia from the datasets but that were not positive in the COVID-19 dataset (n = 47), we compared several methods of predictor discovery: (1) the best prediction model; (2) gene sets of standard pipelines; and (3) a validated gene set for predicting any-onset preeclampsia during the pandemic (n = 404). We chose the most predictive biomarkers from the best method with the significantly largest number of discoveries by a permutation test. The biological relevance was justified by exploring and reanalyzing low- and high-level, multiomics information.

Results

A prediction model using the surrogates developed for predicting any-onset preeclampsia (AUROC of 0.85, 95 % confidence interval [CI] 0.77 to 0.93) was the only that was well-replicated in an independent dataset with no intervention. No model was well-replicated in datasets with a vitamin D intervention. None of the blood biomarkers with high weights in the best model overlapped with blood DEGs. Blood biomarkers were transcripts of integrin-α5 (ITGA5), interferon regulatory factor-6 (IRF6), and P2X purinoreceptor-7 (P2RX7) from the prediction model, which was the only method that significantly discovered eligible blood biomarkers (n = 3/100 combinations, 3.0 %; P =.036). Most of the predicted events (73.70 %) among any-onset preeclampsia were cluster A as defined by ITGA5 (Z-score ≥ 1.1), but were only a minority (6.34 %) among positives in the COVID-19 dataset. The remaining were predicted events (26.30 %) among any-onset preeclampsia or those among COVID-19 infection (93.66 %) if IRF6 Z-score was ≥-0.73 (clusters B and C), in which none was the predicted events among either late-onset preeclampsia (LOPE) or COVID-19 infection if P2RX7 Z-score was <0.13 (cluster C). Greater proportions of predicted events among LOPE were cluster A (82.85 % vs 70.53 %) compared to early-onset preeclampsia (EOPE). The biological relevance by multiomics information explained the biomarker mechanism, polymicrobial infection in any-onset preeclampsia by ITGA5, viral co-infection in EOPE by ITGA5-IRF6, a shared prediction with COVID-19 infection by ITGA5-IRF6-P2RX7, and non-replicability in datasets with a vitamin D intervention by ITGA5.

Conclusions

In a model that predicts preeclampsia but not COVID-19 infection, the important predictors were genes in maternal blood that were not extremely expressed, including the proposed blood biomarkers. The predictive performance and biological relevance should be validated in future experiments.

A novel regulated network mediated by downregulation HIF1A-AS2 lncRNA impairs placental angiogenesis by promoting ANGPTL4 expression in preeclampsia

Preeclampsia (PE) is the predominant medical condition leading to maternal and fetal mortality, and the lack of effective treatment increases its risk to the public health. Among the numerous predisposing factors, the ineffectual remodeling of the uterine spiral arteries, which can induce abnormal placental angiogenesis, has been focused to solve the pathogenesis of PE. According to the preceding research results, abnormal expression of long non-coding RNAs (lncRNA)s could be associated with the pathological changes inducing PE. To be more specific, lncRNA HIF1A-AS2 was proposed for its potential to participate in the molecular mechanisms underlying PE. In vitro, in trophoblast cell lines HTR-8/SVneo and human umbilical vein endothelial cells HUVECs, HIF1A-AS2 knockdown inhibited cell proliferation, migration and tube formation. Mechanistically, transcription factor FOXP1 could regulate the expression of HIF1A-AS2. Moreover, a series of assays, including RNA pull down and mass spectrometry, RNA immunoprecipitation and chromatin immunoprecipitation assay, revealed that HIF1A-AS2 interacted with Lamin A/C (LMNA) to inhibit ANGPTL4 expression in trophoblast cells, thus further participating in the progression of PE. Taken together, these findings suggested that further analysis on HIF1A-AS2 could contribute to the development of prospective therapeutic strategy for PE.

Novel Early Pregnancy Multimarker Screening Test for Preeclampsia Risk Prediction

Preeclampsia (PE) is a common pregnancy-linked disease, causing preterm births, complicated deliveries, and health consequences for mothers and offspring. We have previously developed 6PLEX, a multiplex assay that measures PE-related maternal serum biomarkers ADAM12, sENG, leptin, PlGF, sFlt-1, and PTX3 in a single test tube. This study investigated the potential of 6PLEX to develop novel PE prediction models for early pregnancy. We analyzed 132 serum samples drawn at 70–275 gestational days (g days) from 53 pregnant women (PE, n = 22; controls, n = 31). PE prediction models were developed using a machine learning strategy based on the stepwise selection of the most significant models and incorporating parameters with optimal resampling. Alternative models included also placental FLT1 rs4769613 T/C genotypes, a high-confidence risk factor for PE. The best performing PE prediction model using samples collected at 70–98 g days comprised of PTX3, sFlt-1, and ADAM12, the subject's parity and gestational age at sampling (AUC 0.94 [95%CI 0.84–0.99]). All cases, that developed PE several months later (onset 257.4 ± 15.2 g days), were correctly identified. The model's specificity was 80% [95%CI 65–100] and the overall accuracy was 88% [95%CI 73–95]. Incorporating additionally the placental FLT1 rs4769613 T/C genotype data increased the prediction accuracy to 93.5% [AUC = 0.97 (95%CI 0.89–1.00)]. However, 6PLEX measurements of samples collected at 100–182 g days were insufficiently informative to develop reliable PE prediction models for mid-pregnancy (accuracy <75%). In summary, the developed model opens new horizons for first-trimester PE screening, combining the easily standardizable 6PLEX assay with routinely collected antenatal care data and resulting in high sensitivity and specificity.

Factors Involved in Endothelial Dysfunction Related to Angiogenic Disbalance and Oxidative Stress, in Women at High Risk of Term Pre-Eclampsia

Oxidative and inflammatory stress, angiogenic imbalance, and endothelial dysfunction are pathophysiological mechanisms occurring in pre-eclampsia (PE) that may persist over time and predispose women to a higher risk of cardiovascular disease (CVD) in the future. However, there is little evidence on the vascular function of women at risk of PE who have not developed the disease. The main objective of this research is to study factors and biomarkers involved in endothelial dysfunction related to oxidative stress, angiogenic disbalance, and inflammation in women at high risk of term PE who do not develop the disease. An observational, analytical, retrospective, and descriptive study was carried out in a selected sample of 68 high-risk and 57 non-risk of term PE participants in the STATIN study (FFIS/2016/02/ST EUDRACT No: 2016-005206-19). A significant increase in mean arterial pressure (MAP) levels and oxidative stress biomarkers (uric acid, homocysteine, and total serum antioxidant capacity) was found. Biomarkers of inflammation (interleukin-6 and growth differentiation factor 15) and endothelial function (asymmetric dimethylarginine) were significantly elevated in the group at risk of pre-eclampsia. A significative dependence relationship was also established between MAP and interleukin-6 and uric acid. These results suggest that women at high risk of term PE may represent pregnancies with pre-existing maternal risk factors for CVD, manifested by the own cardiovascular overload of pregnancy. A better understanding of maternal cardiovascular function in pregnancy would allow the improved prediction of CVD late in life in women.

Kisspeptin in the Prediction of Pregnancy Complications

Kisspeptin and its receptor are central to reproductive health acting as key regulators of the reproductive endocrine axis in humans. Kisspeptin is most widely recognised as a regulator of gonadotrophin releasing hormone (GnRH) neuronal function. However, recent evidence has demonstrated that kisspeptin and its receptor also play a fundamental role during pregnancy in the regulation of placentation. Kisspeptin is abundantly expressed in syncytiotrophoblasts, and its receptor in both cyto- and syncytio-trophoblasts. Circulating levels of kisspeptin rise dramatically during healthy pregnancy, which have been proposed as having potential as a biomarker of placental function. Indeed, alterations in kisspeptin levels are associated with an increased risk of adverse maternal and foetal complications. This review summarises data evaluating kisspeptin's role as a putative biomarker of pregnancy complications including miscarriage, ectopic pregnancy (EP), preterm birth (PTB), foetal growth restriction (FGR), hypertensive disorders of pregnancy (HDP), pre-eclampsia (PE), gestational diabetes mellitus (GDM), and gestational trophoblastic disease (GTD).

The effect of nicotine-containing products and fetal sex on placenta-associated circulating midpregnancy biomarkers

Background

In utero exposure to nicotine, largely assessed by smoking, is a risk factor for impaired offspring health, while potential effects of non-combustible nicotine use such as snus (oral moist tobacco), are less well-known. Maternal serum concentrations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) may be viewed as “placenta health markers”, known to differ by fetal sex. Maternal smoking during pregnancy has been associated with lower levels of circulating sFlt-1, while the effect of snus on placenta-associated angiogenic factors is unknown. Our aim was to explore if snus and/or smoking exposure was associated with midpregnancy maternal levels of sFlt-1, PlGF and sFlt-1/PlGF ratio if these associations were modified by fetal sex.

Methods

Midpregnancy (16–22 gestational weeks) serum from 2603 Scandinavian women enrolled in the population-based multi-center PreventADALL (Preventing Atopic Dermatitis and ALLergies in children) study was analysed for sFlt-1 and PlGF concentrations by electrochemiluminescence, deriving the sFlt-1/PGF ratio. Nicotine use was assessed by electronic questionnaires at enrollment in 2278 of the women. Univariable and multivariable linear regression models on log transformed outcomes were used to assess the association between nicotine use and biomarker levels. Interaction terms were included to identify whether the associations were modified by fetal sex.

Results

Median sFlt-1, PlGF and sFlt-1/PlGF ratios among women with nicotine exposure information were similar to those of all included women and differed by fetal sex. Current snus use was significantly associated with reduced maternal circulating PlGF levels in adjusted analyses [β − 0.12, (95% CI − 0.20; 0.00) compared to never use, p = 0.020]. A significant interaction between fetal sex and snus exposure was observed for PIGF (p = 0.031). Prior or periconceptional snus use was significantly associated with PIGF in male fetus pregnancies [β − 0.05 (95% CI − 0.09 to (− 0.02)) and β − 0.07 (95% CI − 0.12 to (− 0.02)) compared to never use, p = 0.002]. Smoking was not significantly associated with any circulating biomarkers levels.

Conclusions

Midpregnancy maternal angiogenic profile differed by periconceptional snus use and fetal sex. Snus exposure, perceived as “safe” by users, before or during pregnancy seems to affect midpregnancy placental health in a sex dimorphic manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00443-1.

Prediction of Differentially Expressed Genes and a Diagnostic Signature of Preeclampsia via Integrated Bioinformatics Analysis

Background

Preeclampsia (PE), which has a high incidence rate worldwide, is a potentially dangerous syndrome to pregnant women and newborns. However, the exact mechanism of its pathogenesis is still unclear. In this study, we used bioinformatics analysis to identify hub genes, establish a logistic model, and study immune cell infiltration to clarify the physiopathogenesis of PE.

Methods

We downloaded the GSE75010 and GSE10588 datasets from the GEO database and performed weighted gene coexpression network analysis (WGCNA) as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The online search tool for the retrieval of interacting genes and Cytoscape software were used to identify hub genes, which were then used to establish a logistic model. We also analyzed immune cell infiltration. Finally, we verified the expression of the genes included in the predictive model via RT-PCR.

Results

A total of 100 and 212 differently expressed genes were identified in the GSE75010 and GSE10588 datasets, respectively, and after overlapping with WGCNA results, 17 genes were identified. KEGG and GO analyses further indicated the involvement of these genes in bioprocesses, such as gonadotropin secretion, immune cell infiltration, and the SMAD and MAPK pathways. Additionally, protein-protein interaction network analysis identified 10 hub genes, six (FLT1, FLNB, FSTL3, INHA, TREM1, and SLCO4A1) of which were used to establish a logistic model for PE. RT-PCR analysis also confirmed that, except FSTL3, these genes were upregulated in PE. Our results also indicated that macrophages played the most important role in immune cell infiltration in PE.

Conclusion

This study identified 10 hub genes in PE and used 6 of them to establish a logistic model and also analyzed immune cell infiltration. These findings may enhance the understanding of PE and enable the identification of potential therapeutic targets for PE.

Placental Syndromes-A New Paradigm in Perinatology

Placental syndromes include pregnancy loss, fetal growth restriction, preeclampsia, preterm delivery, premature rupture of membranes, placental abruption and intrauterine fetal demise. This paper discusses the common etiopathogenesis of those syndromes and the role of angiogenic biomarkers in their development. Pregnancy implantation, placental development and maternal adaptation are complex processes in which fetal and maternal cells interact. The syncytiotrophoblast, trophoblast, uterine natural killer cells and regulatory T cells interfere and interact in all the above-mentioned processes. The proper angioneogenesis and vasculogenesis of the placenta, as well as maternal circulatory adaptation, are dependent on angiogenic factor expression. Insufficient maternal immunotolerance, dysregulation in uterine natural killer or regulatory T cell function, syncytiotrophoblast and trophoblast ischemia and hypoxia or impaired balance in angiogenic factors are all related to the occurrence of placental syndromes. Differences in the time of impairment onset and its intensity and correlation with other dysfunctions result in the development of a specific syndrome. The clinical manifestations in the form of a combination of specific symptoms determine the diagnosis. However, they are just symptoms of an underlying complex trophoblast disorder.

Levels of blood pressure, cardiovascular biomarkers and their correlations in women with previous pre-eclamptic pregnancy within 7 years postpartum: a cross-sectional study in Thailand

OBJECTIVE

To assess the levels of blood pressure, cardiovascular biomarkers and their correlations measured within 7 years postpartum in women with previous pre-eclamptic pregnancies compared with women with previous normotensive pregnancies.

DESIGN

Cross-sectional study.

SETTING

Two tertiary hospitals in the southern region of Thailand.

PARTICIPANTS

Women with pre-eclamptic and normotensive pregnancies in the past 7 years were enrolled from 1 October 2019 to 30 April 2021. Eligible women were interviewed, examined for body mass index (BMI) and blood pressure, and donated morning spot urine and blood samples.

PRIMARY OUTCOME MEASURES

Serum high-sensitivity C reactive protein, creatinine, fasting blood glucose (FBS), glycated haemoglobin (HbA1c), low-density lipoprotein (LDL) cholesterol, urine microalbumin to creatinine ratio (UACR) and sodium were measured. Group differences in biomarkers were tested using unpaired t-test, Wilcoxon rank-sum test or χ² test. The levels of blood pressure and biomarkers between the two study groups at <2 years, 2-4 years and >4 years were also compared. The correlations between blood pressure and biomarkers were analysed using Pearson's correlation and partial correlation methods.

RESULTS

From 206 women included in the analysis, 88 had pre-eclamptic pregnancies and 118 had normotensive pregnancies. Compared with women with previous normotensive pregnancies, women with previous pre-eclamptic pregnancies had significantly increased rates of hypertension (31.8% vs 7.6%, p<0.001) and obesity (55.7% vs 40.7%, p=0.038), as well as higher serum levels of FBS (p<0.001), HbA1c (p<0.001), LDL cholesterol (p=0.03), creatinine (p<0.001) and UACR (p<0.001). Correlation coefficients of BMI, serum creatinine and UACR with blood pressure ranged from 0.27 to 0.31.

CONCLUSION

The risk of hypertension after a pre-eclamptic pregnancy increased. Blood pressure measurement combined with BMI, serum creatinine and UACR screening at least once during 7 years postpartum is suggested for early detection of cardiovascular risk.

Identification and Validation of a Five-Gene Diagnostic Signature for Preeclampsia

Preeclampsia is the leading cause of morbidity and mortality for mothers and newborns worldwide. Despite extensive efforts made to understand the underlying pathology of preeclampsia, there is still no clinically useful effective tool for the early diagnosis of preeclampsia. In this study, we conducted a retrospectively multicenter discover-validation study to develop and validate a novel biomarker for preeclampsia diagnosis. We identified 38 differentially expressed genes (DEGs) involved in preeclampsia in a case-control study by analyzing expression profiles in the discovery cohort. We developed a 5-mRNA signature (termed PE5-signature) to diagnose preeclampsia from 38 DEGs using recursive feature elimination with a random forest supervised classification algorithm, including ENG, KRT80, CEBPA, RDH13 and WASH9P. The PE5-signature showed high accuracy in discriminating preeclampsia from controls with a receiver operating characteristic area under the curve value (AUC) of 0.971, a sensitivity of 0.842 and a specificity of 0.950. The PE5-signature was then validated in an independent case-control study and achieved a reliable and robust predictive performance with an AUC of 0.929, a sensitivity of 0.696, and a specificity of 0.946. In summary, we have developed and validated a five-mRNA biomarker panel as a risk assessment tool to assist in the detection of preeclampsia. This gene panel has potential clinical value for early preeclampsia diagnosis and may help us better understand the precise mechanisms involved.

MiR-200b-3p is upregulated in the placental tissues from patients with preeclampsia and promotes the development of preeclampsia via targeting profilin 2

Preeclampsia is a serious pregnancy disorder affecting both maternal and fetal health. However, the pathogenesis of preeclampsia has not been fully understood. This study aimed to investigate the key microRNAs (miRNAs) in the development of preeclampsia. A high-throughput miRNA sequencing analysis for the placental tissues from patients with preeclampsia and healthy controls was conducted, followed by investigation of differentially expressed miRNAs (DEMs) and functional enrichment analysis. Moreover, the expression of a key DEM, named miR-200b-3p, in the preeclampsia patients was validated, and the effects of miR-200b-3p overexpression on the proliferation, migration, and apoptosis of HTR8 trophoblast cells were investigated in vitro. Furthermore, the target gene of miR-200b-3p was investigated based on gene expression profile GSE177049 and miRWalk 2.0 database. The target relationship between miR-200b-3p and profilin 2 (PFN2) was investigated in vitro. A total of 12 DEMs including miR-200b-3p were identified between preeclampsia placental tissues and control placental tissues, which were significantly enriched in several pathways, such as cell adhesion molecules (CAMs) and tight junction. Moreover, increased expression of miR-200b-3p was revealed in the placental tissues of preeclampsia patients, and overexpression of miR-200b-3p suppressed cell proliferation and migration but promoted apoptosis of trophoblast cells. Furthermore, PFN2 was confirmed as a target of miR-200b-3p, and overexpression of PFN2 reversed the inhibitory effects of miR-200b-3p overexpression on trophoblast cell migration. Our findings reveal that miR-200b-3p is upregulated in the placental tissues of patients with preeclampsia and promotes preeclampsia development via PFN2. miR-200b-3p may serve as a promising therapeutic target against preeclampsia.

EZH2 enhances proliferation and migration of trophoblast cell lines by blocking GADD45A-mediated p38/MAPK signaling pathway

Impaired activity of the trophoblasts is a major contributor to the progression of pregnancy pathologies including preeclampsia (PE). This research probed the function of enhancer of zeste homolog 2 (EZH2) in activity of trophoblast cells and its correlation with growth arrest and DNA damage inducible alpha (GADD45A). EZH2 was predicted to be downregulated in placental tissues in PE according to a gene chip analysis, and reduced expression of EZH2 was detected in the placental tissues of patients with PE. Overexpression of EZH2 augmented proliferation and invasiveness of two trophoblast cell lines HTR-8/SVneo and JEG3 cells. EZH2 catalyzed trimethylation of lysine 27 on histone 3 (H3K27me3) in GADD45A promoter to suppress its transcription. GADD45A silencing increased the activity of the trophoblast cell lines and inactivated the p38/mitogen-activated protein kinase (MAPK) signaling pathway. Rescue experiments confirmed that either inhibition of GADD45A or p38 restored the proliferation, migration, and invasiveness of the trophoblast cell lines suppressed by EZH2 silencing. In conclusion, this work suggests that EZH2 enhances activity of trophoblast cell lines by suppressing GADD45A-mediated p38/MAPK signaling pathway.

The Relationship between Angiogenic Factors and Energy Metabolism in Preeclampsia

Antiangiogenic factors are currently used for the prediction of preeclampsia. The present study aimed to evaluate the relationship between antiangiogenic factors and lipid and carbohydrate metabolism in maternal plasma and placenta. We analyzed 56 pregnant women, 30 healthy and 26 with preeclampsia (including early and late onset). We compared antiangiogenic factors soluble Fms-like Tyrosine Kinase-1 (sfLt-1), placental growth factor (PlGF), and soluble endoglin (sEng)), lipid and carbohydrate metabolism in maternal plasma, and lipid metabolism in the placenta from assays of fatty acid oxidation, fatty acid esterification, and triglyceride levels in all groups. Antiangiogenic factors sFlt-1, sFlt-1/PlGF ratio, and sEng showed a positive correlation with triglyceride, free fatty acid, and C-peptide maternal serum levels. However, there was no relationship between angiogenic factors and placental lipid metabolism parameters. Free fatty acids were predictive of elevated sFlt-1 and sEng, while C-peptide was predictive of an elevated sFlt1/PlGF ratio. The findings in this study generate a model to predict elevated antiangiogenic factor values and the relationship between them with different products of lipid and carbohydrate metabolism in maternal serum and placenta in preeclampsia.

Polycyclic aromatic hydrocarbons (PAHs) may explain the paradoxical effects of cigarette use on preeclampsia (PE)

Tobacco smoking and use of snus (smokeless tobacco) are associated with adverse effects on pregnancy and neonatal outcomes. Nicotine is considered a key toxicant involved in effects caused by both smoking and snus, while pyrolysis products including polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke represents the constituents most unequally divided between these two groups of tobacco products. The aim of this review was: i) to compare the impact, in terms of relative effect estimates, of cigarette smoking and use of Swedish snus on pregnancy outcomes using similar non-tobacco user controls, and ii) to examine whether exposure to PAHs from smoking could explain possible differences in impact on pregnancy outcomes. We systematically searched MEDLINE, Embase, PsycInfo, Web of Science and the Cochrane Database of Systematic Reviews up to October 2021 and identified studies reporting risks for adverse pregnancy and neonatal outcomes associated with snus use and with smoking relative to pregnant women with no use of tobacco. Both snus use and smoking were associated with increased risk of stillbirth, preterm birth, and oral cleft malformation, with comparable point estimates. These effects were likely due to comparable nicotine exposure. We also found striking differences. While both smoking and snus increased the risk of having small for gestational age (SGA) infants, risk from maternal smoking was markedly higher as was the reduction in birthweight. In contrast, the risk of preeclampsia (PE) was markedly lower in smokers than in controls, while snus use was associated with a slightly increased risk. We suggest that PAHs acting via AhR may explain the stronger effects of tobacco smoking on SGA and also to the apparent protective effect of cigarette smoking on PE. Possible mechanisms involved include: i) disrupted endocrine control of fetal development as well as placental development and function, and ii) stress adaption and immune suppression in placenta and mother.

Pre-eclampsia: a Scoping Review of Risk Factors and Suggestions for Future Research Direction

Abstract

Most of maternal deaths are preventable, and one-quarter of maternal deaths are due to pre-eclampsia and eclampsia. Prenatal screening is essential for detecting and managing pre-eclampsia. However, pre-eclampsia screening is solely based on maternal risk factors and has low (< 5% in the USA) detection rates. This review looks at pre-eclampsia from engineering, public health, and medical points of view. First, pre-eclampsia is defined clinically, and the biological basis of established risk factors is described. The multiple theories behind pre-eclampsia etiology should serve as the scientific basis behind established risk factors for pre-eclampsia; however, African American race does not have sufficient evidence as a risk factor. We then briefly describe predictive statistical models that have been created to improve screening detection rates, which use a combination of biophysical and biochemical biomarkers, as well as aspects of patient medical history as inputs. Lastly, technologies that aid in advancing pre-eclampsia screening worldwide are explored. The review concludes with suggestions for more robust pre-eclampsia research, which includes diversifying study sites, improving biomarker analytical tools, and for researchers to consider studying patients before they become pregnant to improve pre-eclampsia detection rates. Additionally, researchers must acknowledge the systemic racism involved in using race as a risk factor and include qualitative measures in study designs to capture the effects of racism on patients.

Lay Summary

Pre-eclampsia is a pregnancy-specific hypertensive disorder that can affect almost every organ system and complicates 2-8% of pregnancies globally. Here, we focus on the biological basis of the risk factors that have been identified for the condition. African American race currently does not have sufficient evidence as a risk factor and has been poorly studied. Current clinical methods poorly predict a patient's likelihood of developing pre-eclampsia; thus, researchers have made statistical models that are briefly described in this review. Then, low-cost technologies that aid in advancing pre-eclampsia screening are discussed. The review ends with suggestions for research direction to improve pre-eclampsia screening in all settings.Overall, we suggest that the future of pre-eclampsia screening should aim to identify those at risk before they become pregnant. We also suggest that the clinical standard of assessing patient risk solely on patient characteristics needs to be reevaluated, that study locations of pre-eclampsia research need to be expanded beyond a few high-income countries, and that low-cost technologies should be developed to increase access to prenatal screening.