The two-stage placental model of preeclampsia: An update

Missing links in preeclampsia cell model systems of endothelial dysfunction

Preeclampsia, one of the main hypertensive disorders of pregnancy, is associated with circulating factors released by the ischemic placenta accompanied by systemic endothelial dysfunction. The etiology of preeclampsia remains poorly understood although it is associated with high maternal and fetal mortality and increased cardiovascular disease risk. Most cell model systems used for studying endothelial dysfunction have not taken into account hemodynamic physical factors such as shear-stress forces which may prevent extrapolation of cell data to in vivo settings. We overview the role of hemodynamic forces in modulating endothelial cell function and discuss strategies to reproduce this biological characteristic in vitro to improve our understanding of endothelial dysfunction associated with preeclampsia.

Assessment of CA-125 First-Trimester Values as a Potential Screening Marker for Pre-Eclampsia

Background: Pre-eclampsia is a major public health issue. Current screening methods are based on maternal characteristics and medical history, but complex predictive models combining different clinical and biochemical markers have been proposed. However, although their accuracy is high, the implementation of these models in clinical practice is not always feasible, especially in low- and middle-resource settings. CA-125 is a tumoral marker, accessible and cheap, with proven potential as a severity marker in the third trimester of pregnancy in pre-eclamptic women. Assessment of its use as a first-trimester marker is necessary. Methods: This observational study involved fifty pregnant women between 11 and 14 weeks of pregnancy. Clinical and biochemical markers (PAPP-A), known for their value in pre-eclampsia screening, were recorded for every patient as well as first-trimester value of CA-125 and third-trimester data regarding blood pressure and pregnancy outcome. Results: No statistical correlation between CA-125 and first-trimester markers was observed except with PAPP-A, with which it exhibited a positive correlation. Additionally, no correlation was made between it and third-trimester blood pressure or pregnancy outcomes. Conclusions: CA-125 first-trimester values do not represent a valuable marker for pre-eclampsia screening. Further research on identifying an accessible and cheap marker to improve pre-eclampsia screening in low- and middle-income settings is needed.

Expression of placental glycans and its role in regulating peripheral blood NK cells during preeclampsia: a perspective

Preeclampsia is a pregnancy-related multisystem disorder characterized by altered trophoblast invasion, oxidative stress, exacerbation of systemic inflammatory response, and endothelial damage. The pathogenesis includes hypertension and mild-to-severe microangiopathy in the kidney, liver, placenta, and brain. The main mechanisms involved in its pathogenesis have been proposed to limit trophoblast invasion and increase the release of extracellular vesicles from the syncytiotrophoblast into the maternal circulation, exacerbating the systemic inflammatory response. The placenta expresses glycans as part of its development and maternal immune tolerance during gestation. The expression profile of glycans at the maternal-fetal interface may play a fundamental role in physiological pregnancy changes and disorders such as preeclampsia. It is unclear whether glycans and their lectin-like receptors are involved in the mechanisms of maternal-fetal recognition by immune cells during pregnancy homeostasis. The expression profile of glycans appears to be altered in hypertensive disorders of pregnancy, which could lead to alterations in the placental microenvironment and vascular endothelium in pregnancy conditions such as preeclampsia. Glycans with immunomodulatory properties at the maternal-fetal interface are altered in early-onset severe preeclampsia, implying that innate immune system components, such as NK cells, exacerbate the systemic inflammatory response observed in preeclampsia. In this article, we discuss the evidence for the role of glycans in gestational physiology and the perspective of glycobiology on the pathophysiology of hypertensive disorders in gestation.

Is artificial endometrial preparation more associated with early-onset or late-onset preeclampsia after frozen embryo transfer?

PURPOSE

To explore whether the risks of early- or late-onset preeclampsia vary among frozen embryo transfer (FET) with different regimens for endometrial preparation and fresh embryo transfer (FreET).

METHODS

We retrospectively included a total of 24129 women who achieved singleton delivery during their first cycles of in vitro fertilization (IVF) between January 2012 and March 2020. The risks of early- and late-onset preeclampsia after FET with endometrial preparation by natural ovulation cycles (FET-NC) or by artificial cycles (FET-AC) were compared to that after FreET.

RESULTS

After adjustment via multivariable logistic regression, the total risk of preeclampsia was higher in the FET-AC group compared to the FreET group [2.2% vs. 0.9%; adjusted odds ratio (aOR): 2.00; 95% confidence interval (CI): 1.45-2.76] and FET-NC group (2.2% vs. 0.9%; aOR: 2.17; 95% CI: 1.59-2.96).When stratified by the gestational age at delivery based on < 34 weeks or ≥ 34 weeks, the risk of late-onset preeclampsia remained higher in the FET-AC group than that in the and FreET group (1.8% vs. 0.6%; aOR: 2.56; 95% CI: 1.83-3.58) and the FET-NC group (1.8% vs. 0.6%; aOR: 2.63; 95% CI: 1.86-3.73). We did not find a statistically significant difference in the risk of early-onset preeclampsia among the three groups.

CONCLUSIONS

An artificial regimen for endometrial preparation was more associated with an increased risk of late-onset preeclampsia after FET. Given that FET-AC is widely used in clinical practice, the potential maternal risk factors for late-onset preeclampsia when using the FET-AC regimen should be further explored, considering the maternal origin of late-onset preeclampsia.

Prediction of Early- and Late-Onset Pre-Eclampsia in the Preclinical Stage via Placenta-Specific Extracellular miRNA Profiling

Pre-eclampsia (PE) is one of the severe complications of pregnancy in 3-8% of all cases and is one of the leading causes of maternal and perinatal mortality. The fundamental role in the pathogenesis of PE is assigned to maternal and/or placental factors, whereby the combination and manifestation of which determines the time of onset of the clinical symptoms of PE (before or after 34 weeks of gestation) and their severity. It is known that the expression level of miRNAs, the regulators of signaling cascades in the cell, depends on gestational age. In the present study, we focused on the identification of the placenta-specific miRNAs that differentiate between early- and late-onset pre-eclampsia (ePE and lPE) throughout pregnancy, from the first to the third trimester. A total of 67 patients were analyzed using small RNA deep sequencing and real-time quantitative PCR, which resulted in a core list of miRNAs (let-7b-5p, let-7d-3p, let-7f-5p, let-7i-5p, miR-22-5p, miR-451a, miR-1246, miR-30e-5p, miR-20a-5p, miR-1307-3p, and miR-320e), which in certain combinations can predict ePE or lPE with 100% sensitivity and 84-100% specificity in the 1st trimester of pregnancy. According to the literature data, these miRNA predictors of PE control trophoblast proliferation, invasion, migration, syncytialization, the endoplasmic reticulum unfolded protein response, immune tolerance, angiogenesis, and vascular integrity. The simultaneous detection of let-7d-3p, miR-451a, and miR-1307-3p, resistant to the repeated freezing/thawing of blood serum samples, in combination with biochemical (b-hCG and PAPP-A) and ultrasound (UAPI) parameters, allowed us to develop a universal model for the prediction of ePE and lPE onset (FPR = 15.7% and FNR = 9.5%), which was validated using a test cohort of 48 patients and demonstrated false-positive results in 26.7% of cases and false negatives in 5.6% of cases. For comparison, the use of the generally accepted Astraia program in the analysis of the test cohort of patients led to worse results: FPR = 62.1% and FNR = 33.3%.

Downregulation of miR-455-3p in decidual cells promotes macrophage polarization and suppresses trophoblasts invasion

Preeclampsia (PE) is a common complication of pregnancy, usually accompanied by symptoms such as hypertension and proteinuria. It can induce severe conditions that may result in maternal and fetal morbidity and fatality. In this study, we use bioinformatics analysis to compare microRNA microassay in decidual stromal cells from PE patients and healthy donors. Our result indicated that placentas from PE patients had a higher CCL1/CXCL2 expression, compared with those from healthy donors. Bioinformatics analysis confirmed that decidual stromal cells derived from PE patients expressed significantly lower miR-455-3p than those derived from healthy donors. Transfection of miR-455-3p inhibitors enhanced the CCL2/CXCL8 expression in decidual stromal cells, and luciferase activity assay confirmed that nuclear factor of activated T cells 5 (NFAT5) mRNA was the direct target of miR-455-3p; NFAT5 also promoted cytokine secretion. In the flow cytometry study, higher M1 macrophage infiltration was observed in placentas from PE patients than in those from healthy donors. We also observed that condition medium (CM) derived from decidual stromal cells could significantly promote M1 polarization of macrophages after transfection with miR-455-3p inhibitor; further, transwell invasion assay confirmed that decidual stromal cells-CM educated macrophages suppressed trophoblast invasion. Taken together, our result demonstrates that downregulation of miR-455-3p in decidual stromal cells can promote macrophage polarization and suppress trophoblasts invasion.

Placental exosomal miR-125b triggered endothelial barrier injury in preeclampsia

INTRODUCTION

Preeclampsia (PE) is an elusive life-threatening complication of pregnancy, and maternal endothelial dysfunction induced by components from the impaired placenta is a key hallmark of PE. Placenta-derived exosomes in maternal circulation have been correlated with risk of PE, however, the role of exosomes in PE remains to be determined. We hypothesized that placenta-released exosomes link the placental abnormalities with maternal endothelial dysfunction in PE.

METHODS

Circulating exosomes were collected from plasma samples of preeclamptic patients and normal pregnancies. Endothelial barrier function was examined by transendothelial electrical resistance (TEER) and cell permeability to FITC-dextran assays in human umbilical vein endothelial cells (HUVECs). miR-125b and VE-cadherin gene expression in exosomes and endothelial cells were assessed by qPCR and Western, and the possible post-transcriptional regulation of miR-125b on VE-cadherin was detected by luciferase assay.

RESULTS

We isolated placenta-derived exosomes in the maternal circulation and found that placenta-derived exosomes from preeclamptic patients (PE-exo) leads to endothelial barrier dysfunction. We then identified decreased expression of VE-cadherin in endothelial cells contribute to the breakdown of the endothelial barrier. Further investigations revealed increased exosomal miR-125b in PE-exo directly inhibited VE-cadherin in HUVECs, thereby mediating the adverse effect of PE-exo on endothelial barrier function.

DISCUSSION

Placental exosomes link impaired placentation and endothelial dysfunction, thus providing new insight into the pathophysiology of preeclampsia. Exosomal miRNAs derived from placenta contribute to the endothelial dysfunction in PE and could be a promising therapeutic target for PE.

Growth-Restricted Fetuses and Offspring Reveal Adverse Sex-Specific Metabolic Responses in Preeclamptic Mice Expressing Human sFLT1

Fetal adaptations to harmful intrauterine environments due to pregnancy disorders such as preeclampsia (PE) can negatively program the offspring's metabolism, resulting in long-term metabolic changes. PE is characterized by increased circulating levels of sFLT1, placental dysfunction and fetal growth restriction (FGR). Here we examine the consequences of systemic human sFLT1 overexpression in transgenic PE/FGR mice on the offspring's metabolic phenotype. Histological and molecular analyses of fetal and offspring livers as well as examinations of offspring serum hormones were performed. At 18.5 dpc, sFLT1 overexpression resulted in growth-restricted fetuses with a reduced liver weight, combined with reduced hepatic glycogen storage and histological signs of hemorrhages and hepatocyte apoptosis. This was further associated with altered gene expression of the molecules involved in fatty acid and glucose/glycogen metabolism. In most analyzed features males were more affected than females. The postnatal follow-up revealed an increased weight gain of male PE offspring, and increased serum levels of Insulin and Leptin. This was associated with changes in hepatic gene expression regulating fatty acid and glucose metabolism in male PE offspring. To conclude, our results indicate that sFLT1-related PE/FGR in mice leads to altered fetal liver development, which might result in an adverse metabolic pre-programming of the offspring, specifically targeting males. This could be linked to the known sex differences seen in PE pregnancies in human.

Depression and antidepressant treatment in the development of hypertensive disorders of pregnancy: Results from a prospective cohort study

BACKGROUND

Hypertensive disorders of pregnancy are associated with longer term cardiovascular risk. Understanding if depression or antidepressant use in pregnancy is associated with HDP is important in identifying those potentially vulnerable to poorer health in later life. This study examines if depression and antidepressants are associated with HDP.

METHODS

In all, 815 pregnant women were recruited within an Australian pregnancy cohort study at less than 20 weeks of pregnancy, all undertook the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and were assigned to four groups for this paper: those with unmedicated depression meeting criteria for current depression (n = 97), those taking selective serotonin reuptake inhibitors in early pregnancy (n = 101), those taking serotonin and noradrenaline reuptake inhibitors in early pregnancy (n = 31), and those without depression or taking antidepressant medication (control; n = 586). Women were then assessed again following birth. Hypertensive disorders of pregnancy were diagnosed according to the Society of Obstetric Medicine in Australia and New Zealand Guidelines.

RESULTS

Use of serotonin and noradrenaline reuptake inhibitors (SNRIs) (adjusted risk ratio = 9.10, 95% confidence interval = [3.82, 21.67]) and unmedicated depression (adjusted risk ratio = 3.11, 95% confidence interval = [1.32, 7.35]) were independently associated with significantly higher risk for developing hypertensive disorders of pregnancy compared to controls. Selective serotonin reuptake inhibitors (SSRIs) use did not confer any increased risk. Higher doses of SNRIs, but not selective serotonin reuptake inhibitors, were associated with significantly higher risk for developing HDP (adjusted risk ratio = 4.83, 95% confidence interval = [1.50, 15.58]).

CONCLUSIONS

Our findings suggest that those with depression in pregnancy and/or on an serotonin and noradrenaline reuptake inhibitor should have closer surveillance for the development of hypertensive disorders of pregnancy. These findings support treatment of depression in pregnancy, however, also the consideration of class of antidepressant.

Aspirin for the Prevention of Early and Severe Pre-Eclampsia Recurrence: A Real-World Population-Based Study

BACKGROUND

Many clinical trials have reported that low-dose aspirin decreases the risk of pre-eclampsia in women with prior pre-eclampsia. However, its impact in a real-world population has not been fully assessed.

OBJECTIVES

To assess the rates of low-dose aspirin initiation during pregnancy in women with a history of pre-eclampsia, and to evaluate the impact of low-dose aspirin in prevention of pre-eclampsia recurrence in a real-world population.

STUDY DESIGN

CONCEPTION is a French nationwide cohort study which uses data from the country's National Health Data System database. We included all women in France who gave birth at least twice between 2010-2018, and who had pre-eclampsia during their first pregnancy. Every dispensing of low-dose aspirin (75-300 mg) between the beginning of their second pregnancy and 36 weeks of gestation (WG) was identified. We used Poisson regression models to estimate the adjusted incidence rate ratios (aIRRs) of receiving aspirin at least once during their second pregnancy. In women who had early and/or severe pre-eclampsia during their first pregnancy, we estimated the IRRs of pre-eclampsia recurrence during their second pregnancy according to the aspirin therapy.

RESULTS

In 28,467 women who were included in the study, the aspirin initiation rate during the second pregnancy ranged from 27.8% for women in whose first pregnancy the pre-eclampsia was mild and late, to 79.9% for those women whose pre-eclampsia was severe and early. Just over half (54.3%) of those treated with aspirin-initiated treatment before 16 WG and adhered to treatment. Compared with women with mild and late pre-eclampsia, the aIRRs (95% CI) for receiving aspirin at least once during the second pregnancy were 1.94 (1.86-2.03) for women with severe and late pre-eclampsia, 2.34 (2.17-2.52) for those with early and mild pre-eclampsia, and 2.87 [2.74-3.01] for those with early and severe pre-eclampsia E. Social deprivation was associated with a lower initiation of aspirin (IRR = 0.74 [0.70-0.78]). Aspirin was not associated with a lower risk of mild and late pre-eclampsia, severe and late pre-eclampsia, or mild and early pre-eclampsia during the second pregnancy. The aIRRs for severe and early pre-eclampsia during the second pregnancy were 0.77 (0.62-0.95) for women who received prescribed aspirin at least once, 0.71 (0.5-0.89) for those who initiated aspirin therapy before 16 WG, and 0.60 (0.47-0.77) for those who adhered to aspirin treatment throughout their second pregnancy. The risk of severe and early pre-eclampsia was lower only when the prescribed mean daily dose was ≥ 100 mg/day.

CONCLUSION

In women with a history of pre-eclampsia, aspirin initiation during a second pregnancy and adherence to the prescribed dosage were largely insufficient, especially for women experiencing social deprivation. Aspirin initiated before 16 WG at a dose ≥ 100 mg/day was associated with a lower risk of severe and early pre-eclampsia.

Understanding the Role of Chemerin in the Pathophysiology of Pre-Eclampsia

Chemerin is a multifaceted adipokine that is involved in multiple biological processes, including inflammation, angiogenesis, adipogenesis, and energy metabolism, as well as oxidative stress. There is a vast body of evidence for a crucial role of chemerin in the development of different cardiovascular diseases. Blood chemerin levels, as well as its placental expression, are elevated in patients with pre-eclampsia (PE) and correlate positively with the severity of the disease. This narrative review summarizes the current knowledge about the potential role of chemerin during PE development, with a particular focus on its involvement in oxidative stress and endothelial dysfunction.

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.

Placental cell type deconvolution reveals that cell proportions drive preeclampsia gene expression differences

The placenta mediates adverse pregnancy outcomes, including preeclampsia, which is characterized by gestational hypertension and proteinuria. Placental cell type heterogeneity in preeclampsia is not well-understood and limits mechanistic interpretation of bulk gene expression measures. We generated single-cell RNA-sequencing samples for integration with existing data to create the largest deconvolution reference of 19 fetal and 8 maternal cell types from placental villous tissue (n = 9 biological replicates) at term (n = 40,494 cells). We deconvoluted eight published microarray case-control studies of preeclampsia (n = 173 controls, 157 cases). Preeclampsia was associated with excess extravillous trophoblasts and fewer mesenchymal and Hofbauer cells. Adjustment for cellular composition reduced preeclampsia-associated differentially expressed genes (log2 fold-change cutoff = 0.1, FDR < 0.05) from 1154 to 0, whereas downregulation of mitochondrial biogenesis, aerobic respiration, and ribosome biogenesis were robust to cell type adjustment, suggesting direct changes to these pathways. Cellular composition mediated a substantial proportion of the association between preeclampsia and FLT1 (37.8%, 95% CI [27.5%, 48.8%]), LEP (34.5%, 95% CI [26.0%, 44.9%]), and ENG (34.5%, 95% CI [25.0%, 45.3%]) overexpression. Our findings indicate substantial placental cellular heterogeneity in preeclampsia contributes to previously observed bulk gene expression differences. This deconvolution reference lays the groundwork for cellular heterogeneity-aware investigation into placental dysfunction and adverse birth outcomes.

FtMt reduces oxidative stress-induced trophoblast cell dysfunction via the HIF-1α/VEGF signaling pathway

BACKGROUND

Preeclampsia (PE) is a complication of pregnancy that causes long-term adverse outcomes for the mother and fetus and may even lead to death. Oxidative stress caused by the imbalance of oxidants and antioxidants in the placenta has been considered as one of the key mechanisms of preeclampsia (together with inflammation, etc.), in which the placental mitochondria play an important role. The expression of hypoxia-inducible factor-1 (HIF-1α) and vascular endothelial growth factor (VEGF) is known to be increased in patients with PE. Mitochondrial ferritin (FtMt) is known to protect the mitochondria from oxidative stress, although its specific role in PE remains unclear.

METHODS

We used qRT-PCR and western blotting to detect the expression levels of FtMt, HIF-1α, and VEGF in placental tissues from patients with PE. Human chorionic trophoblast cells were also administered with hypoxia treatment, followed by the detection of cell proliferation, invasion and angiogenic capacity by CCK8, Transwell, and endothelial cell angiogenesis assays; we also detected the expression of HIF-1α and VEGF in these cells. Finally, overexpression or inhibitory FtMt lentiviral vectors, along with negative control vectors, were constructed and transfected into hypoxia-treated human chorionic trophoblast cells; this was followed by analyses of cell function.

RESULTS

The expression levels of FtMt, HIF-1α and VEGF in the PE group were higher than those in the control group (P < 0.05). Following hypoxia, there was an increase in the expression levels of HIF-1α and VEGF protein in trophoblast cells. There was also an increase in invasion ability and vascular formation ability along with a reduction in cell proliferation ability. These effects were reversed by transfecting cells with the knockout FtMt lentivirus vector. The differences were statistically significant.

CONCLUSION

Analyses showed that FtMt plays a key role in the vascular regulation of PE trophoblast cells after hypoxia possibly acting via the HIF-1α/VEGF signaling pathway. These results provide us an enhanced understanding of the pathogenesis of PE and suggest that the HIF-1α/VEGF signaling pathway represents a new target for the treatment of PE.

Hypertension in Pregnancy: What We Now Know

PURPOSE OF REVIEW

Hypertensive disorders of pregnancy remain a highly morbid condition that affects both the mother and fetus, complicate approximately 10% of pregnancies worldwide, and contribute to immediate and long-term cardiovascular outcomes. There is still much to learn regarding pathogenesis and treatment goals.

RECENT FINDINGS

There is updated information on the pathogenesis of preeclampsia and treatment thresholds for HTN in pregnancy. l-Kynurenine, a metabolite of the essential amino acid l-tryptophan, has been implicated in preeclampsia as decreased levels were found in a uninephrectomized pregnant mouse model of preeclampsia, where replacement of l-kynurenine rescued the preeclamptic state. Further, data from CHIPS (The Control of HTN in Pregnancy Study) and CHAP (Chronic HTN and Pregnancy) trials demonstrate not only the safety of lowering blood pressure to either a diastolic goal of 85 mmHg (CHIPS) or less than 160/105 mmHg (CHAP) without detriment to the fetus but the CHAPS trial has also shown a decrease in the rate of preeclampsia in the treatment group.

SUMMARY

We will summarize the different types of hypertensive disorders in pregnancy, updates on the pathogenesis of preeclampsia, and appropriate HTN management based on the latest evidence in order to better care for mother and child.

The Yin and Yang Effect of the Apelinergic System in Oxidative Stress

Apelin is an endogenous ligand for the G protein-coupled receptor APJ and has multiple biological activities in human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. This article reviews the crucial role of apelin in regulating oxidative stress-related processes by promoting prooxidant or antioxidant mechanisms. Following the binding of APJ to different active apelin isoforms and the interaction with several G proteins according to cell types, the apelin/APJ system is able to modulate different intracellular signaling pathways and biological functions, such as vascular tone, platelet aggregation and leukocytes adhesion, myocardial activity, ischemia/reperfusion injury, insulin resistance, inflammation, and cell proliferation and invasion. As a consequence of these multifaceted properties, the role of the apelinergic axis in the pathogenesis of degenerative and proliferative conditions (e.g., Alzheimer's and Parkinson's diseases, osteoporosis, and cancer) is currently investigated. In this view, the dual effect of the apelin/APJ system in the regulation of oxidative stress needs to be more extensively clarified, in order to identify new potential strategies and tools able to selectively modulate this axis according to the tissue-specific profile.

A cost-effective machine learning-based method for preeclampsia risk assessment and driver genes discovery

BACKGROUND

The placenta, as a unique exchange organ between mother and fetus, is essential for successful human pregnancy and fetal health. Preeclampsia (PE) caused by placental dysfunction contributes to both maternal and infant morbidity and mortality. Accurate identification of PE patients plays a vital role in the formulation of treatment plans. However, the traditional clinical methods of PE have a high misdiagnosis rate.

RESULTS

Here, we first designed a computational biology method that used single-cell transcriptome (scRNA-seq) of healthy pregnancy (38 wk) and early-onset PE (28-32 wk) to identify pathological cell subpopulations and predict PE risk. Based on machine learning methods and feature selection techniques, we observed that the Tuning ReliefF (TURF) score hybrid with XGBoost (TURF_XGB) achieved optimal performance, with 92.61% accuracy and 92.46% recall for classifying nine cell subpopulations of healthy placentas. Biological landscapes of placenta heterogeneity could be mapped by the 110 marker genes screened by TURF_XGB, which revealed the superiority of the TURF feature mining. Moreover, we processed the PE dataset with LASSO to obtain 497 biomarkers. Integration analysis of the above two gene sets revealed that dendritic cells were closely associated with early-onset PE, and C1QB and C1QC might drive preeclampsia by mediating inflammation. In addition, an ensemble model-based risk stratification card was developed to classify preeclampsia patients, and its area under the receiver operating characteristic curve (AUC) could reach 0.99. For broader accessibility, we designed an accessible online web server ( http://bioinfor.imu.edu.cn/placenta ).

CONCLUSION

Single-cell transcriptome-based preeclampsia risk assessment using an ensemble machine learning framework is a valuable asset for clinical decision-making. C1QB and C1QC may be involved in the development and progression of early-onset PE by affecting the complement and coagulation cascades pathway that mediate inflammation, which has important implications for better understanding the pathogenesis of PE.

NPFFR2 gene compound heterozygous variants associated with preeclampsia identified by whole-exome sequencing

BACKGROUND

Preeclampsia (PE) is an idiopathic disorder of pregnancy. The exact cause of PE remains unknown. Emerging evidence indicates that the cause of PE is linked to genetic factors. Therefore, the aim of this study was to identify the susceptibility genes for PE.

METHODS

Nine families with severe PE were recruited. The whole-exome sequencing (WES) was performed on each family, and Sanger sequencing was used to identify the potential pathogenic genetic variants.

RESULTS

After a rigorous bioinformatics analysis, compound heterozygous variants in the NPFFR2 gene, NM_004885.2: c.601A > G, p.Met201Val and c.995C > T, p.Ala332Val were found in the No.4 pedigree. Bioinformatics analysis showed that these sites were highly conserved among several species and were predicted to be pathogenic variants according to multiple online mutational function prediction software packages. Due to the compound heterozygous variants of NPFFR2, more bonds are generated between mutant amino acids and spatial adjacent amino acids, which may lead to more stable active conformation of protein and not easy to be degraded.

CONCLUSIONS

We demonstrated for the first time that compound heterozygous variants of the NPFFR2 gene might be potentially associated with severe PE, the results of this study provide clinicians and researchers with a better understanding of the molecular mechanisms underlying severe PE in pregnant women.

Pre-eclampsia

Pre-eclampsia is a life-threatening disease of pregnancy unique to humans and a leading cause of maternal and neonatal morbidity and mortality. Women who survive pre-eclampsia have reduced life expectancy, with increased risks of stroke, cardiovascular disease and diabetes, while babies from a pre-eclamptic pregnancy have increased risks of preterm birth, perinatal death and neurodevelopmental disability and cardiovascular and metabolic disease later in life. Pre-eclampsia is a complex multisystem disease, diagnosed by sudden-onset hypertension (>20 weeks of gestation) and at least one other associated complication, including proteinuria, maternal organ dysfunction or uteroplacental dysfunction. Pre-eclampsia is found only when a placenta is or was recently present and is classified as preterm (delivery <37 weeks of gestation), term (delivery ≥37 weeks of gestation) and postpartum pre-eclampsia. The maternal syndrome of pre-eclampsia is driven by a dysfunctional placenta, which releases factors into maternal blood causing systemic inflammation and widespread maternal endothelial dysfunction. Available treatments target maternal hypertension and seizures, but the only 'cure' for pre-eclampsia is delivery of the dysfunctional placenta and baby, often prematurely. Despite decades of research, the aetiology of pre-eclampsia, particularly of term and postpartum pre-eclampsia, remains poorly defined. Significant advances have been made in the prediction and prevention of preterm pre-eclampsia, which is predicted in early pregnancy through combined screening and is prevented with daily low-dose aspirin, starting before 16 weeks of gestation. By contrast, the prediction of term and postpartum pre-eclampsia is limited and there are no preventive treatments. Future research must investigate the pathogenesis of pre-eclampsia, in particular of term and postpartum pre-eclampsia, and evaluate new prognostic tests and treatments in adequately powered clinical trials.

Preeclampsia: Recent Advances in Predicting, Preventing, and Managing the Maternal and Fetal Life-Threatening Condition

Preeclampsia accounts for one of the most common documented gestational complications, with a prevalence of approximately 2 to 15% of all pregnancies. Defined as gestational hypertension after 20 weeks of pregnancy and coexisting proteinuria or generalized edema, and certain forms of organ damage, it is life-threatening for both the mother and the fetus, in terms of increasing the rate of mortality and morbidity. Preeclamptic pregnancies are strongly associated with significantly higher medical costs. The maternal costs are related to the extra utility of the healthcare system, more resources used during hospitalization, and likely more surgical spending due to an elevated rate of cesarean deliveries. The infant costs also contribute to a large percentage of the expenses as the babies are prone to preterm deliveries and relevant or causative adverse events. Preeclampsia imposes a considerable financial burden on our societies. It is important for healthcare providers and policy-makers to recognize this phenomenon and allocate enough economic budgets and medical and social resources accordingly. The true cellular and molecular mechanisms underlying preeclampsia remain largely unexplained, which is assumed to be a two-stage process of impaired uteroplacental perfusion with or without prior defective trophoblast invasion (stage 1), followed by general endothelial dysfunction and vascular inflammation that lead to systemic organ damages (stage 2). Risk factors for preeclampsia including race, advanced maternal age, obesity, nulliparity, multi-fetal pregnancy, and co-existing medical disorders, can serve as warnings or markers that call for enhanced surveillance of maternal and fetal well-being. Doppler ultrasonography and biomarkers including the mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), and serum pregnancy-associated plasma protein A (PAPP-A) can be used for the prediction of preeclampsia. For women perceived as high-risk individuals for developing preeclampsia, the administration of low-dose aspirin on a daily basis since early pregnancy has proven to be the most effective way to prevent preeclampsia. For preeclamptic females, relevant information, counseling, and suggestions should be provided to facilitate timely intervention or specialty referral. In pregnancies complicated with preeclampsia, closer monitoring and antepartum surveillance including the Doppler ultrasound blood flow study, biophysical profile, non-stress test, and oxytocin challenge test can be arranged. If the results are unfavorable, early intervention and aggressive therapy should be considered. Affected females should have access to higher levels of obstetric units and neonatal institutes. Before, during, and after delivery, monitoring and preparation should be intensified for affected gravidas to avoid serious complications of preeclampsia. In severe cases, delivery of the fetus and the placenta is the ultimate solution to treat preeclampsia. The current review is a summary of recent advances regarding the knowledge of preeclampsia. However, the detailed etiology, pathophysiology, and effect of preeclampsia seem complicated, and further research to address the primary etiology and pathophysiology underlying the clinical manifestations and outcomes is warranted.

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.

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.