Soluble FLT1 sensitizes endothelial cells to inflammatory cytokines by antagonizing VEGF receptor-mediated signalling

A mitochondrial regulator protein, MNRR1, is elevated in the maternal blood of women with preeclampsia

OBJECTIVE

Preeclampsia, one of the most serious obstetric complications, is a heterogenous disorder resulting from different pathologic processes. However, placental oxidative stress and an anti-angiogenic state play a crucial role. Mitochondria are a major source of cellular reactive oxygen species. Abnormalities in mitochondrial structures, proteins, and functions have been observed in the placentae of patients with preeclampsia, thus mitochondrial dysfunction has been implicated in the mechanism of the disease. Mitochondrial nuclear retrograde regulator 1 (MNRR1) is a newly characterized bi-organellar protein with pleiotropic functions. In the mitochondria, this protein regulates cytochrome c oxidase activity and reactive oxygen species production, whereas in the nucleus, it regulates the transcription of a number of genes including response to tissue hypoxia and inflammatory signals. Since MNRR1 expression changes in response to hypoxia and to an inflammatory signal, MNRR1 could be a part of mitochondrial dysfunction and involved in the pathologic process of preeclampsia. This study aimed to determine whether the plasma MNRR1 concentration of women with preeclampsia differed from that of normal pregnant women.

METHODS

This retrospective case-control study included 97 women with preeclampsia, stratified by gestational age at delivery into early (<34 weeks, n = 40) and late (≥34 weeks, n = 57) preeclampsia and by the presence or absence of placental lesions consistent with maternal vascular malperfusion (MVM), the histologic counterpart of an anti-angiogenic state. Women with an uncomplicated pregnancy at various gestational ages who delivered at term served as controls (n = 80) and were further stratified into early (n = 25) and late (n = 55) controls according to gestational age at venipuncture. Maternal plasma MNRR1 concentrations were determined by an enzyme-linked immunosorbent assay.

RESULTS

1) Women with preeclampsia at the time of diagnosis (either early or late disease) had a significantly higher median (interquartile range, IQR) plasma MNRR1 concentration than the controls [early preeclampsia: 1632 (924-2926) pg/mL vs. 630 (448-4002) pg/mL, p = .026, and late preeclampsia: 1833 (1441-5534) pg/mL vs. 910 (526-6178) pg/mL, p = .021]. Among women with early preeclampsia, those with MVM lesions in the placenta had the highest median (IQR) plasma MNRR1 concentration among the three groups [with MVM: 2066 (1070-3188) pg/mL vs. without MVM: 888 (812-1781) pg/mL, p = .03; and with MVM vs. control: 630 (448-4002) pg/mL, p = .04]. There was no significant difference in the median plasma MNRR1 concentration between women with early preeclampsia without MVM lesions and those with an uncomplicated pregnancy (p = .3). By contrast, women with late preeclampsia, regardless of MVM lesions, had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM: 1609 (1392-3135) pg/mL vs. control: 910 (526-6178), p = .045; and without MVM: 2023 (1578-8936) pg/mL vs. control, p = .01].

CONCLUSIONS

MNRR1, a mitochondrial regulator protein, is elevated in the maternal plasma of women with preeclampsia (both early and late) at the time of diagnosis. These findings may reflect some degree of mitochondrial dysfunction, intravascular inflammation, or other unknown pathologic processes that characterize this obstetrical syndrome.

Small RNAs in the pathogenesis of preeclampsia

Preeclampsia is a major contributor to maternal and fetal morbidity and mortality. The disorder can be classified into early- and late-onset subtypes, both of which evolve in two stages. The first stage comprises the development of pre-clinical, utero-placental malperfusion. Early and late utero-placental malperfusion have different causes and time courses. Early-onset preeclampsia (20 % of cases) is driven by dysfunctional placentation in the first half of pregnancy. In late-onset preeclampsia (80 % of cases), malperfusion is a consequence of placental compression within the confines of a limited uterine cavity. In both subtypes, the malperfused placenta releases stress signals into the maternal circulation. These stress signals trigger onset of the clinical syndrome (the second stage). Small RNA molecules, which are implicated in cellular stress responses in general, may be involved at different stages. Micro RNAs contribute to abnormal trophoblast invasion, immune dysregulation, angiogenic imbalance, and syncytiotrophoblast-derived extracellular vesicle signalling in preeclampsia. Transfer RNA fragments are placental signals known to be specifically involved in cell stress responses. Disorder-specific differences in small nucleolar RNAs and piwi-interacting RNAs have also been reported. Here, we summarise key small RNA advances in preeclampsia pathogenesis. We propose that existing small RNA classifications are unhelpful and that non-biased assessment of RNA expression, incorporation of non-annotated molecules and consideration of chemical modifications to RNAs may be important in elucidating preeclampsia pathogenesis.

Genes involved in the cholecystokinin receptor signaling map were differentially expressed in the jejunum of steers with variation in residual feed intake

The jejunum is a critical site for nutrient digestion and absorption, and variation in its ability to take up nutrients within the jejunum is likely to affect feed efficiency. The purpose of this study was to determine differences in gene expression in the jejunum of beef steers divergent for residual feed intake (RFI) in one cohort of steers (Year 1), and to validate those genes in animals from a second study (Year 2). Steers from Year 1 (n = 16) were selected for high and low RFI. Jejunum mucosal tissue was obtained for RNA-seq. Thirty-two genes were differentially expressed (PFDR≤0.15), and five were over-represented in pathways including inflammatory mediator, cholecystokinin receptor (CCKR) signaling, and p38 MAPK pathways. Several differentially expressed genes (ALOX12, ALPI, FABP6, FABP7, FLT1, GSTA2, MEF2B, PDK4, SPP1, and TTF2) have been previously associated with RFI in other studies. Real-time qPCR was used to validate nine differentially expressed genes in the Year 1 steers used for RNA-seq, and in the Year 2 validation cohort. Six genes were validated as differentially expressed (P < 0.1) using RT-qPCR in the Year 1 population. In the Year 2 population, five genes displayed the same direction of expression as the Year 1 population and 3 were differentially expressed (P < 0.1). The CCKR pathway is involved in digestion, appetite control, and regulation of body weight making it a compelling candidate for feed efficiency in cattle, and the validation of these genes in a second population of cattle is suggestive of a role in feed efficiency.

Mechanistic study of pre-eclampsia and macrophage-associated molecular networks: bioinformatics insights from multiple datasets

Background

Pre-eclampsia is a pregnancy-related disorder characterized by hypertension and proteinuria, severely affecting the health and quality of life of patients. However, the molecular mechanism of macrophages in pre-eclampsia is not well understood.

Methods

In this study, the key biomarkers during the development of pre-eclampsia were identified using bioinformatics analysis. The GSE75010 and GSE74341 datasets from the GEO database were obtained and merged for differential analysis. A weighted gene co-expression network analysis (WGCNA) was constructed based on macrophage content, and machine learning methods were employed to identify key genes. Immunoinfiltration analysis completed by the CIBERSORT method, R package "ClusterProfiler" to explore functional enrichment of these intersection genes, and potential drug predictions were conducted using the CMap database. Lastly, independent analysis of protein levels, localization, and quantitative analysis was performed on placental tissues collected from both preeclampsia patients and healthy control groups.

Results

We identified 70 differentially expressed NETs genes and found 367 macrophage-related genes through WGCNA analysis. Machine learning identified three key genes: FNBP1L, NMUR1, and PP14571. These three key genes were significantly associated with immune cell content and enriched in multiple signaling pathways. Specifically, these genes were upregulated in PE patients. These findings establish the expression patterns of three key genes associated with M2 macrophage infiltration, providing potential targets for understanding the pathogenesis and treatment of PE. Additionally, CMap results suggested four potential drugs, including Ttnpb, Doxorubicin, Tyrphostin AG 825, and Tanespimycin, which may have the potential to reverse pre-eclampsia.

Conclusion

Studying the expression levels of three key genes in pre-eclampsia provides valuable insights into the prevention and treatment of this condition. We propose that these genes play a crucial role in regulating the maternal-fetal immune microenvironment in PE patients, and the pathways associated with these genes offer potential avenues for exploring the molecular mechanisms underlying preeclampsia and identifying therapeutic targets. Additionally, by utilizing the Connectivity Map database, we identified drug targets like Ttnpb, Doxorubicin, Tyrphostin AG 825, and Tanespimycin as potential clinical treatments for preeclampsia.

Tumor Necrosis Factor Inhibitor Use Increases Birthweight in Pregnant Women With Rheumatoid Arthritis Independently of the Soluble Fms-Like Tyrosine Kinase-1/Placental Growth Factor Ratio

BACKGROUND

To study whether the use of TNF (tumor necrosis factor) inhibitors (TNFi) by pregnant women with rheumatoid arthritis affects sFlt-1 (soluble Fms-like tyrosine kinase-1), PlGF (placental growth factor), or their impact on birthweight.

METHODS AND RESULTS

sFlt-1 and PlGF were measured in all trimesters of pregnancy in the Preconception Counseling in Active Rheumatoid Arthritis study and were compared according to the use of TNFi. The association of sFlt-1 and PlGF with birthweight in relation to TNFi was determined. The study included 158 women, of whom 52.5% used TNFi during pregnancy. Both sFlt-1 and PlGF increased during pregnancy, whereas their ratio declined. Taking into consideration the trimester-related variation in levels of sFlt-1 and PlGF, after correction for relevant confounders, the sFlt-1/PlGF ratio was not significantly different between patients who did or did not use TNFi (sFlt-1/PlGF ratio in the second trimester compared with the first trimester: estimated change 8.17 [95% CI, 2.54-26.29], P=0.79; sFlt-1/PlGF ratio in the third trimester compared with the first trimester: estimated change 6.25 [95% CI, 1.73-22.50], P=0.25). In women who did not use TNFi, birthweight was significantly lower (3180 versus 3302 g; P=0.03), and sFlt-1 displayed a negative correlation with birthweight (r=-0.462, P<0.001) and birthweight percentile (r=-0.332, P=0.008). In TNFi users, these correlations were absent.

CONCLUSIONS

TNF inhibitor use increases birthweight in pregnant women with rheumatoid arthritis independently of the sFlt-1/PlGF ratio.

REGISTRATION

http://clinicaltrials.gov. Unique identifier: NCT01345071.

Preeclampsia at term: evidence of disease heterogeneity based on the profile of circulating cytokines and angiogenic factors

BACKGROUND

Intravascular inflammation and an antiangiogenic state have been implicated in the pathophysiology of preeclampsia. On the basis of the profiles of their angiogenic/antiangiogenic factors, women with preeclampsia at term may be classified into 2 subgroups with different characteristics and prevalence of adverse outcomes. This study was undertaken to examine whether these 2 subgroups of preeclampsia at term also show differences in their profiles of intravascular inflammation.

OBJECTIVE

This study aimed to determine the plasma profiles of cytokines and chemokines in women with preeclampsia at term who had a normal or an abnormal angiogenic profile.

STUDY DESIGN

A nested case-control study was conducted to include women classified into 3 groups: women with an uncomplicated pregnancy (n=213) and women with preeclampsia at term with a normal (n=55) or an abnormal (n=41) angiogenic profile. An abnormal angiogenic profile was defined as a plasma ratio of placental growth factor and soluble fms-like tyrosine kinase-1 multiple of the median <10th percentile for gestational age. Concentrations of cytokines were measured by multiplex immunoassays.

RESULTS

Women with preeclampsia at term and an abnormal angiogenic profile showed evidence of the greatest intravascular inflammation among the study groups. These women had higher plasma concentrations of 5 cytokines (interleukin-6, interleukin-8, interleukin-12/interleukin-23p40, interleukin-15, and interleukin-16) and 7 chemokines (eotaxin, eotaxin-3, interferon-γ inducible protein-10, monocyte chemotactic protein-4, macrophage inflammatory protein-1β, macrophage-derived chemokine, and thymus and activation-regulated chemokine compared to women with an uncomplicated pregnancy. By contrast, women with preeclampsia at term and a normal angiogenic profile, compared to women with an uncomplicated pregnancy, had only a higher plasma concentration of monocyte chemotactic protein-4. A correlation between severity of the antiangiogenic state, blood pressure, and plasma concentrations of a subset of cytokines was observed.

CONCLUSION

Term preeclampsia can be classified into 2 clusters. One is characterized by an antiangiogenic state coupled with an excessive inflammatory process, whereas the other has neither of these features. These findings further support the heterogeneity of preeclampsia at term and may explain the distinct clinical outcomes.

Differential 5'-tRNA Fragment Expression in Circulating Preeclampsia Syncytiotrophoblast Vesicles Drives Macrophage Inflammation

BACKGROUND

The relationship between placental pathology and the maternal syndrome of preeclampsia is incompletely characterized. Mismatch between placental nutrient supply and fetal demands induces stress in the syncytiotrophoblast, the layer of placenta in direct contact with maternal blood. Such stress alters the content and increases the release of syncytiotrophoblast extracellular vesicles (STB-EVs) into the maternal circulation. We have previously shown 5'-tRNA fragments (5'-tRFs) constitute the majority of small RNA in STB-EVs in healthy pregnancy. 5'-tRFs are produced in response to stress. We hypothesized STB-EV 5'-tRF release might change in preeclampsia.

METHODS

We perfused placentas from 8 women with early-onset preeclampsia and 6 controls, comparing small RNA expression in STB-EVs. We used membrane-affinity columns to isolate maternal plasma vesicles and investigate placental 5'-tRFs in vivo. We quantified 5'-tRFs from circulating STB-EVs using a placental alkaline phosphatase immunoassay. 5'-tRFs and scrambled RNA controls were added to monocyte, macrophage and endothelial cells in culture to investigate transcriptional responses.

RESULTS

5'-tRFs constitute the majority of small RNA in STB-EVs from both preeclampsia and normal pregnancies. More than 900 small RNA fragments are differentially expressed in preeclampsia STB-EVs. Preeclampsia-dysregulated 5'-tRFs are detectable in maternal plasma, where we identified a placentally derived load. 5'-tRF-Glu-CTC, the most abundant preeclampsia-upregulated 5'-tRF in perfusion STB-EVs, is also increased in preeclampsia STB-EVs from maternal plasma. 5'-tRF-Glu-CTC induced inflammation in macrophages but not monocytes. The conditioned media from 5'-tRF-Glu-CTC-activated macrophages reduced eNOS (endothelial NO synthase) expression in endothelial cells.

CONCLUSIONS

Increased release of syncytiotrophoblast-derived vesicle-bound 5'-tRF-Glu-CTC contributes to preeclampsia pathophysiology.

A multi-tissue metabolome atlas of primate pregnancy

Pregnancy induces dramatic metabolic changes in females; yet, the intricacies of this metabolic reprogramming remain poorly understood, especially in primates. Using cynomolgus monkeys, we constructed a comprehensive multi-tissue metabolome atlas, analyzing 273 samples from 23 maternal tissues during pregnancy. We discovered a decline in metabolic coupling between tissues as pregnancy progressed. Core metabolic pathways that were rewired during primate pregnancy included steroidogenesis, fatty acid metabolism, and arachidonic acid metabolism. Our atlas revealed 91 pregnancy-adaptive metabolites changing consistently across 23 tissues, whose roles we verified in human cell models and patient samples. Corticosterone and palmitoyl-carnitine regulated placental maturation and maternal tissue progenitors, respectively, with implications for maternal preeclampsia, diabetes, cardiac hypertrophy, and muscle and liver regeneration. Moreover, we found that corticosterone deficiency induced preeclampsia-like inflammation, indicating the atlas's potential clinical value. Overall, our multi-tissue metabolome atlas serves as a framework for elucidating the role of metabolic regulation in female health during pregnancy.

Hypertensive Disorders in Pregnancy: Global Burden From 1990 to 2019, Current Research Hotspots and Emerging Trends

Hypertensive disorders in pregnancy (HDP) constitute a worldwide health problem for pregnant women and their infants. This study provided HDP burden over 1990 to 2019 by region and age distribution, and predicted changes in related values for the next 25 years. We then conducted an econometric analysis of the author distribution, collaborative networks, keyword burst clustering, and spatio-temporal analysis of HDP-related publications from 2012 to 2022 to access current scientific developments and hotspots. The number of pregnant women with HDP has been increasing over the past 30 years, with regional and age-stratified differences in the burden of disease. Additionally, projections suggest an increase of deaths due to maternal HDP among adolescents younger than 20 years. Current research is mostly centered on pre-eclampsia, with hot keywords including trophoblast, immune tolerance, frozen-thawed embryo transfer, aspirin, gestational diabetes association, and biomarkers. Researches on the pathological mechanism, classification, and subtypes of HDP need to be further advanced.

Diabetic retinopathy: emerging concepts of current and potential therapy

Diabetic retinopathy (DR) is one of the leading causes of permanent central blindness worldwide. Despite the complexity and inadequate understanding of DR pathogenesis, many of the underlying pathways are currently partially understood and may offer potential targets for future treatments. Anti-VEGF medications are currently the main medication for this problem. This article provides an overview of the established pharmacological treatments and those that are being developed to cure DR. We firstly reviewed the widely utilized approaches including pan-retinal photocoagulation therapy, anti-VEGF therapy, corticosteroid therapy, and surgical management of DR. Next, we discussed the mechanisms of action and prospective benefits of novel candidate medications. Current management are far from being a perfect treatment for DR, despite mild-term favorable efficiency and safety profiles. Pharmacological research should work toward developing longer-lasting treatments or new drug delivery systems, as well as on identifying new molecular targets in the pathogenetical mechanism for DR. In order to find a treatment that is specifically designed for each patient, it is also necessary to properly characterize patients, taking into account elements like hereditary factors and intraretinal neovascularization stages for effective utilization of drugs. The current and potential approaches for diabetic retinopathy. Image was constructed using Biorender.com.

Pathophysiological impact of CXC and CX3CL1 chemokines in preeclampsia and gestational diabetes mellitus

Diabetes-related pathophysiological alterations and various female reproductive difficulties were common in pregnant women with gestational diabetes mellitus (GDM), who had 21.1 million live births. Preeclampsia (PE), which increases maternal and fetal morbidity and mortality, affects approximately 3%-5% of pregnancies worldwide. Nevertheless, it is unclear what triggers PE and GDM to develop. Therefore, the development of novel moderator therapy approaches is a crucial advancement. Chemokines regulate physiological defenses and maternal-fetal interaction during healthy and disturbed pregnancies. Chemokines regulate immunity, stem cell trafficking, anti-angiogenesis, and cell attraction. CXC chemokines are usually inflammatory and contribute to numerous reproductive disorders. Fractalkine (CX3CL1) may be membrane-bound or soluble. CX3CL1 aids cell survival during homeostasis and inflammation. Evidence reveals that CXC and CX3CL1 chemokines and their receptors have been the focus of therapeutic discoveries for clinical intervention due to their considerable participation in numerous biological processes. This review aims to give an overview of the functions of CXC and CX3CL1 chemokines and their receptors in the pathophysiology of PE and GDM. Finally, we examined stimulus specificity for CXC and CX3CL1 chemokine expression and synthesis in PE and GDM and preclinical and clinical trials of CXC-based PE and GDM therapies.

Fetal microchimerism and the two-stage model of preeclampsia

Fetal cells cross the placenta during pregnancy and some have the ability to persist in maternal organs and circulation long-term, a phenomenon termed fetal microchimerism. These cells often belong to stem cell or immune cell lineages. The long-term effects of fetal microchimerism are likely mixed, potentially depending on the amount of fetal cells transferred, fetal-maternal histocompatibility and fetal cell-specific properties. Both human and animal data indicate that fetal-origin cells partake in tissue repair and may benefit maternal health overall. On the other hand, these cells have been implicated in inflammatory diseases by studies showing increased fetal microchimerism in women with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. During pregnancy, preeclampsia is associated with increased cell-transfer between the mother and fetus, and an increase in immune cell subsets. In the current review, we discuss potential mechanisms of transplacental transfer, including passive leakage across the compromised diffusion barrier and active recruitment of cells residing in the placenta or fetal circulation. Within the conceptual framework of the two-stage model of preeclampsia, where syncytiotrophoblast stress is a common pathophysiological pathway to maternal and fetal clinical features of preeclampsia, we argue that microchimerism may represent a mechanistic link between stage 1 placental dysfunction and stage 2 maternal cardiovascular inflammation and endothelial dysfunction. Finally, we postulate that fetal microchimerism may contribute to the known association between placental syndromes and increased long-term maternal cardiovascular disease risk. Fetal microchimerism research represents an exciting opportunity for developing new disease biomarkers and targeted prophylaxis against maternal diseases.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

Dietary supplements and vascular function in hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy are complications that can lead to maternal and infant mortality and morbidity. Hypertensive disorders of pregnancy are generally defined as hypertension and may be accompanied by other end organ damages including proteinuria, maternal organ disturbances including renal insufficiency, neurological complications, thrombocytopenia, impaired liver function, or uteroplacental dysfunction such as fetal growth restriction and stillbirth. Although the causes of these hypertensive disorders of pregnancy are multifactorial and elusive, they seem to share some common vascular-related mechanisms, including diseased spiral arteries, placental ischemia, and endothelial dysfunction. Recently, preeclampsia is being considered as a vascular disorder. Unfortunately, due to the complex etiology of preeclampsia and safety concerns on drug usage during pregnancy, there is still no effective pharmacological treatments available for preeclampsia yet. An emerging area of interest in this research field is the potential beneficial effects of dietary intervention on reducing the risk of preeclampsia. Recent studies have been focused on the association between deficiencies or excesses of some nutrients and complications during pregnancy, fetal growth and development, and later risk of cardiovascular and metabolic diseases in the offspring. In this review, we discuss the involvement of placental vascular dysfunction in preeclampsia. We summarize the current understanding of the association between abnormal placentation and preeclampsia in a vascular perspective. Finally, we evaluate several studied dietary supplementations to prevent and reduce the risk of preeclampsia, targeting placental vascular development and function, leading to improved pregnancy and postnatal outcomes.

Investigating the Effects of Atrial Natriuretic Peptide on the Maternal Endothelium to Determine Potential Implications for Preeclampsia

Preeclampsia is associated with an increased lifelong risk of cardiovascular disease (CVD). It is not clear whether this is induced by persistent systemic organ and vascular damage following preeclampsia or due to a predisposition to both conditions that share cardiovascular pathophysiology. Common to both CVD and preeclampsia is the dysregulation of corin and its proteolytic product, atrial natriuretic peptide (ANP). ANP, a hypotensive hormone converted from pro-ANP by corin, is involved in blood pressure homeostasis. While corin is predominantly a cardiac enzyme, both corin and pro-ANP are significantly upregulated in the gravid uterus and dysregulated in preeclampsia. Relatively little is known about ANP function in the endothelium during a pregnancy complicated by preeclampsia. Here, we investigated the effect of ANP on endothelial cell proliferation and migration, markers of endothelial dysfunction, and receptor expression in omental arteries exposed to circulating preeclamptic toxins. ANP receptor expression is significantly upregulated in preeclamptic vasculature but not because of exposure to preeclampsia toxins tumour necrosis factor α or soluble fms-like tyrosine kinase-1. The supplementation of endothelial cells with ANP did not promote proliferation or migration, nor did ANP improve markers of endothelial dysfunction. The role of ANP in preeclampsia is unlikely to be via endothelial pathways.

The Endothelial Glycocalyx as a Target of Excess Soluble Fms-like Tyrosine Kinase-1

Soluble fms-like tyrosine kinase-1 (sFlt-1) is a secreted protein that binds heparan sulfate expressed on the endothelial glycocalyx (eGC). In this paper we analyze how excess sFlt-1 causes conformational changes in the eGC, leading to monocyte adhesion, a key event triggering vascular dysfunction. In vitro exposure of primary human umbilical vein endothelial cells to excess sFlt-1 decreased eGC height and increased stiffness as determined by atomic force microscopy (AFM). Yet, structural loss of the eGC components was not observed, as indicated by Ulex europaeus agglutinin I and wheat germ agglutinin staining. Moreover, the conformation observed under excess sFlt-1, a collapsed eGC, is flat and stiff with unchanged coverage and sustained content. Functionally, this conformation increased the endothelial adhesiveness to THP-1 monocytes by about 35%. Heparin blocked all these effects, but the vascular endothelial growth factor did not. In vivo administration of sFlt-1 in mice also resulted in the collapse of the eGC in isolated aorta analyzed ex vivo by AFM. Our findings show that excess sFlt-1 causes the collapse of the eGC and favors leukocyte adhesion. This study provides an additional mechanism of action by which sFlt-1 may cause endothelial dysfunction and injury.

Perturbation of placental protein glycosylation by endoplasmic reticulum stress promotes maladaptation of maternal hepatic glucose metabolism

Placental hormones orchestrate maternal metabolic adaptations to support pregnancy. We hypothesized that placental ER stress, which characterizes early-onset pre-eclampsia (ePE), compromises glycosylation, reducing hormone bioactivity and these maladaptations predispose the mother to metabolic disease in later life. We demonstrate ER stress reduces the complexity and sialylation of trophoblast protein N-glycosylation, while aberrant glycosylation of vascular endothelial growth factor reduced its bioactivity. ER stress alters the expression of 66 of the 146 genes annotated with "protein glycosylation" and reduces the expression of sialyltransferases. Using mouse placental explants, we show ER stress promotes the secretion of mis-glycosylated glycoproteins. Pregnant mice carrying placentas with junctional zone-specific ER stress have reduced blood glucose, anomalous hepatic glucose metabolism, increased cellular stress and elevated DNA methyltransferase 3A. Using pregnancy-specific glycoproteins as a readout, we also demonstrate aberrant glycosylation of placental proteins in women with ePE, thus providing a mechanistic link between ePE and subsequent maternal metabolic disorders.

One-third of patients with eclampsia at term do not have an abnormal angiogenic profile

OBJECTIVES

An abnormal angiogenic profile is present in about one-half of women with preeclampsia at term. Few studies examined the roles of angiogenic biomarkers in eclampsia. The aims of this study were to determine (1) whether the degree of an anti-angiogenic state, reflected by a low placental growth factor (PlGF) to soluble fms-like tyrosine kinase-1 (sFlt-1) ratio, in women with eclampsia differed from that of women with severe preeclampsia; and (2) the prevalence of women who had an abnormal angiogenic profile at the diagnoses of preterm and term eclampsia.

METHODS

A cross-sectional study was conducted to include women in the following groups: (1) uncomplicated pregnancy (n=40); (2) severe preeclampsia (n=50); and (3) eclampsia (n=35). Maternal serum concentrations of PlGF and sFlt-1 were determined by immunoassays.

RESULTS

Women with preterm, but not term, eclampsia had a more severe anti-angiogenic state than those with severe preeclampsia (lower PlGF and PlGF/sFlt-1 ratio, each p<0.05). However, the difference diminished in magnitude with increasing gestational age (interaction, p=0.005). An abnormal angiogenic profile was present in 95% (19/20) of women with preterm eclampsia but in only 67% (10/15) of women with eclampsia at term.

CONCLUSIONS

Angiogenic biomarkers can be used for risk assessment of preterm eclampsia. By contrast, a normal profile of angiogenic biomarkers cannot reliably exclude patients at risk for eclampsia at term. This observation has major clinical implications given that angiogenic biomarkers are frequently used in the triage area as a test to rule out preeclampsia.

The Soluble Fms-like Tyrosine Kinase-1 Contributes to Structural and Functional Changes in Endothelial Cells in Chronic Kidney Disease

Endothelial cells are a critical target of the soluble Fms-like tyrosine kinase-1 (sFlt-1), a soluble factor increased in different diseases with varying degrees of renal impairment and endothelial dysfunction, including chronic kidney disease (CKD). Although the mechanisms underlying endothelial dysfunction are multifactorial and complex, herein, we investigated the damaging effects of sFlt-1 on structural and functional changes in endothelial cells. Our results evidenced that sera from patients with CKD stiffen the endothelial cell cortex in vitro, an effect correlated with sFlt-1 levels and prevented by sFlt-1 neutralization. Besides, we could show that recombinant sFlt-1 leads to endothelial stiffening in vitro and in vivo. This was accompanied by cytoskeleton reorganization and changes in the endothelial barrier function, as observed by increased actin polymerization and endothelial cell permeability, respectively. These results depended on the activation of the p38 MAPK and were blocked by the specific inhibitor SB203580. However, sFlt-1 only minimally affected the expression of stiffness-sensitive genes. These findings bring new insight into the mechanism of action of sFlt-1 and its biological effects that cannot be exclusively ascribed to the regulation of angiogenesis.

The role of miRNA-210 in pre-eclampsia development

MicroRNAs (miRNAs) are a class of small non-coding, single-stranded RNAs (ribonucleic acids) that play important roles in many vital processes through their impact on gene expression. One such miRNA, miR210, represents a hypoxia-induced cellular miRNA group that hold a variety of functions. This review article highlights the importance of miR-210 in the development of pre-eclampsia.KEY MESSAGEmiR-210 is a promising biomarker for monitoring pregnancy with pre-eclampsia. Overexpression of miR-210 had a negative impact on the process of cell migration and trophoblast invasion.

The Role of Cluster C19MC in Pre-Eclampsia Development

Pre-eclampsia is a placenta-related complication occurring in 2-10% of all pregnancies. miRNAs are a group of non-coding RNAs regulating gene expression. There is evidence that C19MC miRNAs are involved in the development of the placenta. Deregulation of chromosome 19 microRNA cluster (C19MC) miRNAs expression leads to impaired cell differentiation, abnormal trophoblast invasion and pathological angiogenesis, which can lead to the development of pre-eclampsia. Information was obtained through a review of articles available in PubMed Medline. Articles on the role of the C19MC miRNA in the development of pre-eclampsia published in 2009-2022 were analyzed. This review article summarizes the current data on the role of the C19MC miRNA in the development of pre-eclampsia. They indicate a significant increase in the expression of most C19MC miRNAs in placental tissue and a high level of circulating fractions in serum and plasma, both in the first and/or third trimester in women with PE. Only for miR-525-5p, low levels of plasma expression were noted in the first trimester, and in the placenta in the third trimester. The search for molecular factors indicating the development of pre-eclampsia before the onset of clinical symptoms seems to be a promising diagnostic route. Identifying women at risk of developing pre-eclampsia at the pre-symptomatic stage would avoid serious complications in both mothers and fetuses. We believe that miRNAs belonging to cluster C19MC could be promising biomarkers of pre-eclampsia development.

Vascular endothelial growth factor and its receptors regulation in gestational diabetes mellitus and eclampsia

Background

An imbalance in the expression of vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) during pregnancy plays an important role in the pathogenesis of gestational diabetes mellitus (GDM) and eclampsia. VEGF and its receptors change during the regulation of blood vessels as a result of risk factors such as familial genetics. These modifications include loss of original balance of serological indicators, upregulation or downregulation of growth factor indicators, and changes in the placenta, kidney, liver and other organs to varying degrees of damage. This has an impact on both the pregnant woman's and the fetus's health.

Main body

This paper summarizes the mechanisms of unbalanced VEGF and receptor expression based on data from relevant literature on GDM and eclampsia. An Imbalance in VEGF and its binding receptor is often associated with the occurrence of multiple pregnancy disorders. In recent years, researchers have focused on the potential role of VEGF and its receptors in the development of GDM and eclampsia.

Conclusion

This paper summarizes the different VEGF subtypes and their binding receptors, as well as mechanisms that cause GDM and eclampsia, in order to provide valuable data to inform monitoring, diagnosis, and prognosis.

Increased Risk of Preeclampsia in Women With a Genetic Predisposition to Elevated Blood Pressure

BACKGROUND

Preeclampsia causes significant maternal and perinatal morbidity. Genetic factors seem to affect the onset of the disease. We aimed to investigate whether the polygenic risk score for blood pressure (BP; BP-PRS) is associated with preeclampsia, its subtypes, and BP values during pregnancy.

METHODS

The analyses were performed in the FINNPEC study (Finnish Genetics of Pre-Eclampsia Consortium) cohort of 1514 preeclamptic and 983 control women. In a case-control setting, the data were divided into percentiles to compare women with high BP-PRS (HBP-PRS; >95th percentile) or low BP-PRS (≤5th percentile) to others. Furthermore, to evaluate the effect of BP-PRS on BP, we studied 3 cohorts: women with preeclampsia, hypertensive controls, and normotensive controls.

RESULTS

BP values were higher in women with HBP-PRS throughout the pregnancy. Preeclampsia was more common in women with HBP-PRS compared with others (71.8% and 60.1%, respectively; P=0.009), and women with low BP-PRS presented with preeclampsia less frequently than others (44.8% and 61.5%, respectively; P<0.001). HBP-PRS was associated with an increased risk for preeclampsia (odds ratio, 1.7 [95% CI, 1.1-2.5]). Furthermore, women with HBP-PRS presented with recurrent preeclampsia and preeclampsia with severe features more often.

CONCLUSIONS

Our results suggest that HBP-PRS is associated with an increased risk of preeclampsia, recurrent preeclampsia, and preeclampsia with severe features. Furthermore, women with HBP-PRS present higher BP values during pregnancy. The results strengthen the evidence pointing toward the role of genetic variants associated with BP regulation in the etiology of preeclampsia, especially its more severe forms.

Assessment of the Proton Pump Inhibitor, Esomeprazole Magnesium Hydrate and Trihydrate, on Pathophysiological Markers of Preeclampsia in Preclinical Human Models of Disease

Previously, we demonstrated that the proton pump inhibitor, esomeprazole magnesium hydrate (MH), could have potential as a repurposed treatment against preeclampsia, a serious obstetric condition. In this study we investigate the difference in the preclinical effectiveness between 100 µM of esomeprazole MH and its hydration isomer, esomeprazole magnesium trihydrate (MTH). Here, we found that both treatments reduced secretion of sFLT-1 (anti-angiogenic factor) from primary cytotrophoblast, but only esomeprazole MH reduced sFLT-1 secretion from primary human umbilical vein endothelial cells (assessed via ELISA). Both drugs could mitigate expression of the endothelial dysfunction markers, vascular cell adhesion molecule-1 and endothelin-1 (via qPCR). Neither esomeprazole MH nor MTH quenched cytotrophoblast reactive oxygen species production in response to sodium azide (ROS assay). Finally, using wire myography, we demonstrated that both compounds were able to induce vasodilation of human omental arteries at 100 µM. Esomeprazole is safe to use in pregnancy and a candidate treatment for preeclampsia. Using primary human tissues and cells, we validated that esomeprazole is effective in enhancing vascular relaxation, and can reduce key factors associated with preeclampsia, including sFLT-1 and endothelial dysfunction. However, esomeprazole MH was more efficacious than esomeprazole MTH in our in vitro studies.

A Review of Nanotechnology for Treating Dysfunctional Placenta

The placenta plays a significant role during pregnancy. Placental dysfunction contributes to major obstetric complications, such as fetal growth restriction and preeclampsia. Currently, there is no effective treatment for placental dysfunction in the perinatal period, and prophylaxis is often delivered too late, at which point the disease manifestation cannot be prevented. However, with recent integration of nanoscience and medicine to perform elaborate experiments on the human placenta, it is expected that novel and efficient nanotherapies will be developed to resolve the challenge of managing placental dysfunction. The advent of nanomedicine has enabled the safe and targeted delivery of drugs using nanoparticles. These smart nanoparticles can load the necessary therapeutic substances that specifically target the placenta, such as drugs, targeting molecules, and ligands. Packaging multifunctional molecules into specific delivery systems with high targeting ability, diagnosis, and treatment has emerged as a novel theragnostic (both therapeutic and diagnostic) approach. In this review, the authors discuss recent advances in nanotechnology for placental dysfunction treatment. In particular, the authors highlight potential candidate nanoparticle-loaded molecules that target the placenta to improve utero-placental blood flow, and reduce reactive oxygen species and oxidative stress. The authors intend to provide basic insight and understanding of placental dysfunction, potential delivery targets, and recent research on placenta-targeted nanoparticle delivery systems for the potential treatment of placental dysfunction. The authors hope that this review will sensitize the reader for continued exploration of novel nanomedicines.

S-Nitrosoglutathione Reductase Deficiency Causes Aberrant Placental S-Nitrosylation and Preeclampsia

Background

Preeclampsia, a leading cause of maternal and fetal mortality and morbidity, is characterized by an increase in S‐nitrosylated proteins and reactive oxygen species, suggesting a pathophysiologic role for dysregulation in nitrosylation and nitrosative stress.

Methods and Results

Here, we show that mice lacking S‐nitrosoglutathione reductase (GSNOR^−⁄−), a denitrosylase regulating protein S‐nitrosylation, exhibit a preeclampsia phenotype, including hypertension, proteinuria, renal pathology, cardiac concentric hypertrophy, decreased placental vascularization, and fetal growth retardation. Reactive oxygen species, NO, and peroxynitrite levels are elevated. Importantly, mass spectrometry reveals elevated placental S‐nitrosylated amino acid residues in GSNOR^−⁄− mice. Ascorbate reverses the phenotype except for fetal weight, reduces the difference in the S‐nitrosoproteome, and identifies a unique set of S‐nitrosylated proteins in GSNOR^−⁄− mice. Importantly, human preeclamptic placentas exhibit decreased GSNOR activity and increased nitrosative stress.

Conclusions

Therefore, deficiency of GSNOR creates dysregulation of placental S‐nitrosylation and preeclampsia in mice, which can be rescued by ascorbate. Coupled with similar findings in human placentas, these findings offer valuable insights and therapeutic implications for preeclampsia.

Tocotrienol in Pre-Eclampsia Prevention: A Mechanistic Analysis in Relation to the Pathophysiological Framework

The pathophysiology of pre-eclampsia involves two major pathways, namely systemic oxidative stress and subsequent generalised inflammatory response, which eventually culminates in endothelial cell injury and the syndrome of pre-eclampsia with multi-organ dysfunction. Aspirin has been used to reduce the risk of pre-eclampsia, but it only possesses anti-inflammatory properties without any antioxidant effect. Hence, it can only partially alleviate the problem. Tocotrienols are a unique form of vitamin E with strong antioxidant and anti-inflammatory properties that can be exploited as a preventive agent for pre-eclampsia. Many preclinical models showed that tocotrienol can also prevent hypertension and ischaemic/reperfusion injury, which are the two main features in pre-eclampsia. This review explores the mechanism of action of tocotrienol in relation to the pathophysiology of pre-eclampsia. In conclusion, the study provides sufficient justification for the establishment of a large clinical trial to thoroughly assess the capability of tocotrienol in preventing pre-eclampsia.

Slowing of fetal growth and elevated maternal serum sFLT1:PlGF are associated with early term spontaneous labor

Background

The physiological control of human parturition at term is unknown.

Objective

This study aimed to test the hypothesis that slowing of fetal growth or elevated maternal serum levels of markers of placental hypoxia in late gestation will be associated with earlier term labor.

Study Design

We observed 2208 women having first births and performed serial blinded ultrasonography and immunoassay of soluble fms-like tyrosine kinase-1 and placenta growth factor. We estimated the probability of spontaneous delivery from 37 weeks of gestational age concerning (1) fetal growth between 20 and 36 weeks of gestational age and (2) the maternal serum soluble fms-like tyrosine kinase-1–to–placenta growth factor ratio measured at approximately 36 weeks of gestational age. Data were analyzed using logistic regression and Cox regression.

Results

Fetal size at 36 weeks of gestational age was not independently associated with the timing of delivery at term. However, there was an inverse relationship between fetal growth between 20 weeks of gestational age and 36 weeks of gestational age and the probability of spontaneous labor at 37 to 38 weeks’ gestation (hazard ratio [95% confidence interval] for a 50 percentile increase in abdominal circumference growth velocity, 0.60 [0.47–0.78]; P=.0001). This association was weaker at 39 to 40 weeks’ gestation (0.83 [0.74–0.93]; P=.0013), and there was no association at ≥41 weeks’ gestation. Very similar associations were observed for estimated fetal weight growth velocity. There was a positive relationship between soluble fms-like tyrosine kinase-1–to–placenta growth factor ratio and the probability of spontaneous labor at 37 to 38 weeks’ gestation (hazard ratio [95% confidence interval] for a 50 percentile increase in soluble fms-like tyrosine kinase-1–to–placenta growth factor ratio, 3.05 [2.32–4.02]; P<.0001). This association was weaker at 39 to 40 weeks’ gestation (1.46 [1.30–1.63]; P<.0001), and there was no association at ≥41 weeks’ gestation. Adjustment for maternal characteristics was without material effect on any of these associations.

Conclusion

Slowing of fetal growth and biomarkers of placental insufficiency were associated with an increased probability of early onset of spontaneous term labor. We speculated that progressive placental insufficiency may be a physiological phenomenon that occurs with advancing gestational age near and at term and promotes the initiation of labor.

A Novel Peptide Ameliorates TNFα- and LPS-Induced Endothelia Dysfunction in Preeclampsia

BACKGROUND

To investigate the protective effects of the novel peptide antiendothelial dysfunction peptide in preeclampsia (AEDPPE) on tumor necrosis factor α (TNFα)- and lipopolysaccharide (LPS)-induced injury in the vascular endothelium in preeclampsia.

METHODS

The effects of AEDPPE on TNFα-induced vascular endothelial injury were assessed by enzyme-linked immunosorbent assay, quantitative real-time PCR, mitochondrial membrane potential assay, Cell Counting Kit-8 assay, THP-1 monocyte-human umbilical vein endothelial cell (HUVEC) adhesion assay, endothelial tube-forming assay, transcriptomic analysis, preeclamptic symptom analysis, and histological analysis in preeclampsia-like rat models induced by LPS.

RESULTS

AEDPPE alleviated the upregulation of antiangiogenic factors including soluble fms-like tyrosine kinase-1, endothelin-1, and tissue plasminogen activator and attenuated the reduction in mitochondrial potential induced by TNFα in HUVECs. In addition, AEDPPE treatment counteracted the decrease in tube formation and decreased the numbers of THP-1 monocytes attached to HUVECs caused by TNFα. Mechanistically, cytokine-cytokine receptor interactions enriched many genes and the TNF signaling pathway may be involved in this phenomenon. Moreover, cotreatment with LPS and AEDPPE significantly reversed the preeclampsia-like phenotype including hypertension and proteinuria and improved the functions of the kidney and placenta.

CONCLUSIONS

AEDPPE effectively ameliorated the vascular endothelial injury induced by TNFα and LPS in preeclampsia. We suggest that AEDPPE may be a novel therapeutic candidate for preeclampsia treatment. These findings demonstrate that AEDPPE may play an effective role in ameliorating vascular endothelial dysfunction and be a potential therapeutic agent for preeclampsia.

sFlt-1 and CA 15.3 are indicators of endothelial damage and pulmonary fibrosis in SARS-CoV-2 infection

COVID-19 pandemic led to a worldwide increase of hospitalizations for interstitial pneumonia with thrombosis complications, endothelial injury and multiorgan disease. Common CT findings include lung bilateral infiltrates, bilateral ground-glass opacities and/or consolidation whilst no current laboratory parameter consents rapidly evaluation of COVID-19 risk and disease severity. In the present work we investigated the association of sFLT-1 and CA 15.3 with endothelial damage and pulmonary fibrosis. Serum sFlt-1 has been associated with endothelial injury and sepsis severity, CA 15.3 seems an alternative marker for KL-6 for fibrotic lung diseases and pulmonary interstitial damage. We analysed 262 SARS-CoV-2 patients with differing levels of clinical severity; we found an association of serum sFlt-1 (ROC AUC 0.902, decision threshold > 90.3 pg/mL, p < 0.001 Sens. 83.9% and Spec. 86.7%) with presence, extent and severity of the disease. Moreover, CA 15.3 appeared significantly increased in COVID-19 severe lung fibrosis (ICU vs NON-ICU patients 42.6 ± 3.3 vs 25.7 ± 1.5 U/mL, p < 0.0001) and was associated with lung damage severity grade (ROC AUC 0.958, decision threshold > 24.8 U/mL, p < 0.0001, Sens. 88.4% and Spec. 91.8%). In conclusion, serum levels of sFlt-1 and CA 15.3 appeared useful tools for categorizing COVID-19 clinical stage and may represent a valid aid for clinicians to better personalise treatment.

TNFα blockade reverses vascular and uteroplacental matrix metalloproteinases imbalance and collagen accumulation in hypertensive pregnant rats

Preeclampsia is a pregnancy-related disorder of maternal hypertension-in-pregnancy (HTN-Preg) and often fetal growth restriction (FGR). Placental ischemia could be an initiating event leading to inadequate vascular and uteroplacental remodeling and HTN-Preg; however, the molecular targets are unclear. To test the hypothesis that placental ischemia-induced release of proinflammatory cytokines target vascular and uteroplacental matrix metalloproteinases (MMPs), we tested if infusing TNFα (200 ng/kg/day) in day-14 pregnant (Preg) rats causes MMP imbalance and collagen accumulation, and if infusing TNFα decoy receptor Etanercept (0.4 mg/kg/day) in HTN-Preg rats with reduced uteroplacental perfusion pressure (RUPP) reverses MMP imbalance and collagen accumulation. On gestational day-19, blood pressure (BP) was higher in Preg + TNFα and RUPP vs Preg rats, and restored in RUPP + Etanercept rats. Gelatin zymography and Western blots revealed decreases in MMP-2 and MMP-9 and increases in MMP-1 and MMP-7 in aorta, uterus and placenta of Preg + TNFα and RUPP, that were reversed in RUPP + Etanercept rats. Collagen-I and IV were abundant in Preg + TNFα and RUPP, and were decreased in RUPP + Etanercept rats. The litter size, uterine, placenta, and pup weight were markedly reduced in RUPP, insignificantly reduced in Preg + TNFα, and slightly improved in RUPP + Etanercept rats. Thus TNFα blockade reverses the decreases in vascular and uteroplacental MMP-2 and MMP-9, and the increases in MMP-1, MMP-7 and accumulation of collagen-I and IV induced by placental ischemia and TNFα in HTN-Preg rats. Targeting TNFα using cytokine antagonists, or MMPs using MMP modulators could rectify MMP imbalance and collagen accumulation, restore vascular and uteroplacental remodeling, and improve BP in HTN-Preg and preeclampsia.

Preeclampsia and postpartum mental health: mechanisms and clinical implications

Preeclampsia is one of the leading causes of maternal morbidity and mortality worldwide, with the short and long-term implications for maternal health being increasingly recognized. Yet the effects of preeclampsia on mental health are often overlooked, effects which can be evident both immediately postpartum and decades later. In particular, preeclampsia has been associated with increased risk and severity of cognitive impairment, psychosocial distress, and psychiatric disorders including depression, anxiety, and post-traumatic stress disorder. While these outcomes are reported, few have proposed how the pathophysiology of preeclampsia may contribute to changes in postpartum mental health. Studies have suggested that anti-angiogenic factors and pro-inflammatory cytokines released from the preeclamptic placenta may damage the blood-brain barrier endothelium, leading to long-term structural and functional cerebral changes. These changes may contribute to subsequent impairments in mental health. In addition, the pro-inflammatory profile and patterns of cerebral damage observed in preeclampsia are similar to that of psychiatric disorders and cognitive impairment, suggesting they may share common mechanisms. Yet, there is limited evidence on how these mechanisms may interact. The purpose of this review is to summarize the evidence for these pathophysiological mechanisms and propose how they may work synergistically to affect brain structure, cognition, and postpartum mental health in preeclampsia. The role of psychosocial factors, disease severity, and psychological treatment in the mental health of preeclampsia patients will also be discussed.

Circulating Soluble Fms-like Tyrosine Kinase in Renal Diseases Other than Preeclampsia

Soluble Fms-like tyrosine kinase (sFlt-1/sVEGFR1) is a naturally occurring antagonist of vascular endothelial growth factor (VEGF). Despite being a secreted, soluble protein lacking cytoplasmic and transmembrane domains, sFlt-1 can act locally and be protective against excessive microenvironmental VEGF concentration or exert autocrine functions independently of VEGF. Circulating sFlt-1 may indiscriminately affect endothelial function and the microvasculature of distant target organs. The clinical significance of excess sFlt-1 in kidney disease was first shown in preeclampsia, a major renal complication of pregnancy. However, circulating sFlt-1 levels appear to be increased in various diseases with varying degrees of renal impairment. Relevant clinical associations between circulating sFlt-1 and severe outcomes (e.g., endothelial dysfunction, renal impairment, cardiovascular disease, and all-cause mortality) have been observed in patients with CKD and after kidney transplantation. However, sFlt-1 appears to be protective against renal dysfunction-associated aggravation of atherosclerosis and diabetic nephropathy. Therefore, in this study, we provide an update on sFlt-1 in several kidney diseases other than preeclampsia, discuss clinical findings and experimental studies, and briefly consider its use in clinical practice.

Elevated Levels of Soluble Axl (sAxl) Regulates Key Angiogenic Molecules to Induce Placental Endothelial Dysfunction and a Preeclampsia-Like Phenotype

Preeclampsia (PE), a severe pregnancy-specific syndrome, is characterized by impaired placental angiogenesis. Although the pathogenesis of this condition remains largely unclear, vascular systemic endothelial injury is thought to be the common contributing factor. Soluble Axl (sAxl), a biomarker of endothelial dysfunction, is known to be abnormally increased in a variety of diseases associated with vascular injury. In a previous study, we found that the plasma levels of sAxl were significantly higher in PE with severe features (sPE) than in pregnant women who did not have PE. The current study aimed to further explore the potential role of sAxl in vascular injury in patients with sPE. We found that the upregulation of sAxl in maternal plasma was positively correlated with the plasma levels of sFlt-1 and negatively correlated with placental NO synthase (eNOS) in women with sPE. Furthermore, elevated levels of sAxl suppressed proliferation and endothelial tube formation and promoted cytotoxicity in human umbilical vein endothelial cells (HUVECs) through the downregulation of p-Akt, p-p70S6K, p-mTOR, and Grb2. Subsequently, we established a pregnant rat model with PE-like characteristics by injecting pregnant rats with an adenovirus expressing sAxl. These rats exhibited a typical PE-like phenotype, including increased blood pressure, proteinuria, and fetal growth restriction, along with abnormal placental and fetal renal morphology. In conclusion, our study demonstrated the role of sAxl in systemic vascular injury through the regulation of the expression of key molecules of angiogenesis and described its potential contribution to the development of sPE.

Model for Early Prediction of Preeclampsia: A Nested Case Controlled Study in Indian Women

Purpose

Preeclampsia (PE) affects 5-7% of the pregnancies worldwide, and is one of the most dreaded disorders of pregnancy contributing to maternal and neonatal mortality. PE is mostly presented in the third trimester of pregnancy. Here, we used serum placental growth factor (PIGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) to develop a model for predicting PE in Indian women in early second trimester.

Methods

In this case-control study, a total 1452 healthy pregnant women were recruited. Blood samples were collected at the following gestational weeks (GWs), 12-20 (GW1), 21-28 (GW2) and 29-term (GW3), and post-delivery. Body mass index (BMI) was calculated by anthropometric measurements. Serum sFlt-1, PIGF and VEGF were analyzed by ELISA. A predictive model for PE was developed using multivariable logistic regression analysis.

Results

In PE cases, serum PlGF and VEGF levels were significantly lower at each GW, while serum sFlt-1 was lower only at GW1, relative to age-matched controls, (n = 132/group). Age-matched comparison between PE cases and controls indicated that sFlt-1 was associated with decreased PE outcome (Odds ratio. OR = 0.988, CI = 0.982-0.993), whereas sFlt-1/PlGF ratio (OR = 1.577, CI = 1.344-1.920) and BMI (OR = 1.334, CI = 1.187-1.520) were associated with increased PE outcome. Logistic regression was used to develop a predictive model for PE at GW1. Using testing dataset, model was externally validated which resulted in 88% accuracy in predicting PE cases at 0.5 probability cutoff.

Conclusion

Prediction model using sFlt-1, sFlt-1/PlGF ratio and BMI may be useful to predict PE as early as 12-20 weeks in women with optimal sensitivity and specificity.

Transforming growth factor-β1 signalling triggers vascular endothelial growth factor resistance and monocyte dysfunction in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) leads to monocyte dysfunction associated with atherogenesis and defective arteriogenesis. Transforming growth factor (TGF)-β1, placenta growth factor (PlGF)-1 and vascular endothelial growth factor (VEGF)A play important roles in atherogenesis and arteriogenesis. VEGF-receptor (VEGFR)-mediated monocyte migration is inhibited in T2DM (VEGFA resistance), while TGF-β1-induced monocyte migration is fully functional. Therefore, we hypothesize that TGF-β antagonises the VEGFA responses in human monocytes. We demonstrate that monocytes from T2DM patients have an increased migratory response towards low concentrations of TGF-β1, while PlGF-1/VEGFA responses are mitigated. Mechanistically, this is due to increased expression of type II TGF-β receptor in monocytes under high-glucose conditions and increased expression of soluble (s)VEGFR1, which is known to interfere with VEGFA signalling. VEGFA resistance in monocytes from T2DM patients can be rescued by either experimental down-regulation of TGF-β receptor expression in vitro or by functional blocking of TGF-β signalling using either a TGF-β receptor kinase inhibitor or a TGF-β neutralizing antibody. Our data demonstrate that both T2DM and high-glucose potentiate the TGF-β pathway. TGF-β signalling impairs VEGFR-mediated responses in T2DM monocytes and in this way contributes to mononuclear cell dysfunction, provide novel insights into T2DM vascular dysfunction.

Multi-tissue transcriptomic analysis reveals that L-methionine supplementation maintains the physiological homeostasis of broiler chickens than D-methionine under acute heat stress

The objective of this study was to compare the effects of supplementation with two methionine isoforms, L-methionine (L-Met) or D-methionine (D-Met), on transcriptome expression in broiler chickens under acute heat stress. A total of 240 one-day-old chicks were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement: thermo-neutral vs. acute heat-stress and L-Met vs. D-Met supplementation. On day 14, the heat-stressed group was exposed to 32°C for 5 h, while the others remained at 25°C. Six chicks were randomly selected per treatment and total RNA was isolated from whole blood, ileum, and liver tissues. Two RNA samples from each tissue of each treatment group were randomly selected and pooled in equal amounts. A total of 1.87 billion raw reads obtained from 36 samples (four treatments × three tissues × three composited replicates) were mapped to the reference genome build (Gallus_gallus-5.0) and used to identify differentially expressed genes (DEGs) using DESeq2. Functional enrichment of DEGs was tested using DAVID. Comparing the two isoforms of supplemented methionine, two, three, and ten genes were differentially expressed (> 1 or < -1 log₂ fold change) in whole blood, ileum, and liver, respectively. A total of 38, 71, and 16 genes were differentially expressed in response to the interaction between heat stress and Met isoforms in the blood, ileum, and liver, respectively. Three-tissue-specific DEGs were functionally enriched for regulation of cholesterol homeostasis and metabolism, glucose metabolism, and vascular patterning. Chicks fed with L-Met had lower immune (e.g., IL4I1 and SERPINI1) and intestinal angiogenic responses (e.g., FLT1 and FGD5), and stable glucose and lipid metabolism (e.g., PCK1 and LDLR) under heat stress conditions. In conclusion, unlike D-Met, L-Met supplementation seems to help maintain physiological homeostasis and enhances cellular defense systems against external stresses like high environmental temperature.

Influenza A virus causes maternal and fetal pathology via innate and adaptive vascular inflammation in mice

Influenza infection during pregnancy is associated with increased maternal and perinatal complications. Here, we show that, during pregnancy, influenza infection leads to viral dissemination into the aorta, resulting in a peripheral “vascular storm” characterized by enhanced inflammatory mediators; the influx of Ly6C monocytes, neutrophils, and T cells; and impaired vascular function. The ensuing vascular storm induced hypoxia in the placenta and fetal brain and caused an increase in circulating cell free fetal DNA and soluble Flt1 release. We demonstrate that vascular dysfunction occurs in response to viral infection during pregnancy, which may explain the high rates of morbidity and mortality in pregnant dams, as well as the downstream perinatal complications associated with influenza infection.

Influenza A virus (IAV) infection during pregnancy causes severe maternal and perinatal complications, despite a lack of vertical transmission of IAV across the placenta. Here, we demonstrate a significant alteration in the maternal vascular landscape that underpins the maternal and downstream fetal pathology to IAV infection in mice. In IAV infection of nonpregnant mice, the local lung inflammatory response was contained to the lungs and was self-resolving, whereas in pregnant mice, virus dissemination to major maternal blood vessels, including the aorta, resulted in a peripheral "vascular storm," with elevated proinflammatory and antiviral mediators and the influx of Ly6C^low and Ly6C^high monocytes, plus neutrophils and T cells. This vascular storm was associated with elevated levels of the adhesion molecules ICAM and VCAM and the pattern-recognition receptors TLR7 and TLR9 in the vascular wall, resulting in profound vascular dysfunction. The sequalae of this IAV-driven vascular storm included placental growth retardation and intrauterine growth restriction, evidence of placental and fetal brain hypoxia, and increased circulating cell free fetal DNA and soluble Flt1. In contrast, IAV infection in nonpregnant mice caused no obvious alterations in endothelial function or vascular inflammation. Therefore, IAV infection during pregnancy drives a significant systemic vascular alteration in pregnant dams, which likely suppresses critical blood flow to the placenta and fetus. This study in mice provides a fundamental mechanistic insight and a paradigm into how an immune response to a respiratory virus, such as IAV, is likely to specifically drive maternal and fetal pathologies during pregnancy.

Hemodynamic Complications in Pregnancy: Preeclampsia and Beyond

Normal pregnancy is a complex and dynamic process that requires significant adaptation from the maternal system. Failure of this adaptive process in pregnancy contributes to many pregnancy related disorders, including the hypertensive disorders of pregnancy. This article discusses placental development and how abnormalities in the process of vascular remodeling contribute to the multisystem maternal and fetal disease that is preeclampsia and fetal growth restriction. We review some of the consequences of this condition on the mother and fetus, aspects of the clinical management of preeclampsia and how it can influence both mother and infant in the postnatal period and beyond.

MZe786 Rescues Cardiac Mitochondrial Activity in High sFlt-1 and Low HO-1 Environment

Hypertensive disorder in pregnancy is a major cause of maternal and perinatal mortality worldwide. Women who have had preeclampsia are at three to four times higher risk in later life of developing high blood pressure and heart disease. Soluble Flt-1 (sFlt-1) is elevated in preeclampsia and may remain high postpartum in women with a history of preeclampsia. Heme oxygenase-1 (Hmox1/HO-1) exerts protective effects against oxidative stimuli and is compromised in the placenta of pregnant women with preeclampsia. We hypothesized that sFlt-1 inhibits cardiac mitochondrial activity in HO-1 deficient mice. HO-1 haplo-insufficient mice (Hmox1^+/−) were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) or control virus (Ad-CMV). Subsequently, they were treated daily with either placebo or MZe786 for six days, when the heart tissue was harvested to assess cardiac mitochondrial activity. Here, we show that the loss of HO-1 disturbed cardiac mitochondrial respiration and reduced mitochondrial biogenesis. The overexpression of sFlt-1 resulted in the inhibition of the cardiac mitochondrial activity in Hmox1^+/− mice. The present study demonstrates that the hydrogen sulfide (H₂S) releasing molecule, MZe786, rescues mitochondrial activity by stimulating cardiac mitochondrial biogenesis and antioxidant defense in Hmox1^−/− mice and in Hmox1^+/− mice exposed to a high sFlt-1 environment.

Updates in Diagnosis and Management of Preeclampsia in Women with CKD

It is estimated that women with CKD are ten times more likely to develop preeclampsia than women without CKD, with preeclampsia affecting up to 40% of pregnancies in women with CKD. However, the shared phenotype of hypertension, proteinuria, and impaired excretory kidney function complicates the diagnosis of superimposed preeclampsia in women with CKD who have hypertension and/or proteinuria that predates pregnancy. This article outlines the diagnoses of preeclampsia and superimposed preeclampsia. It discusses the pathogenesis of preeclampsia, including abnormal placentation and angiogenic dysfunction. The clinical use of angiogenic markers as diagnostic adjuncts for women with suspected preeclampsia is described, and the limited data on the use of these markers in women with CKD are presented. The role of kidney biopsy in pregnancy is examined. The management of preeclampsia is outlined, including important advances and controversies in aspirin prophylaxis, BP treatment targets, and the timing of delivery.

The role of circulating soluble fms-like tyrosine kinase-1 in patients with diabetic foot ulcer: A possible mechanism of pathogenesis via a novel link between oxidative stress, inflammation and angiogenesis

BACKGROUND

Diabetic foot ulcer (DFU) is one of the most devastating diabetic consequences leading to amputations. Oxidative stress, inflammation, vascular insufficiency and neuropathy have been linked to DFU development. Since soluble fms-like tyrosine kinase-1 (sFlt-1) is one of the anti-angiogenic factors regulating vascular endothelial growth factor (VEGF) biological activity. So, we aimed to evaluate its role in pathogenesis of DFU and its correlation with oxidative stress and inflammatory markers.

METHODS

60 type 2 diabetic patients: 30 without DFU and 30 with DFU in addition to 20 healthy controls were enrolled in the study. sFlt-1 and VEGF mRNA relative gene expressions and levels and sFlt-1/VEGF ratio were assessed. Also, Advanced oxidation protein products (AOPPs), malondialdhyde (MDA), Total thiol and, tumor necrosis factor alpha (TNF-α) levels were measured.

RESULTS

sFlt-1 expression and level, AOPPs, MDA and TNF-α were significantly higher in diabetic patients as compared with the control group with highest levels in DFU patients. However, there were significant decrease in total thiol level and VEGF expression and level in diabetic patients with DFU.

CONCLUSION

This study revealed that sFlt-1 is a major player in DFU pathogenesis and may be considered as a novel diagnostic biomarker for early detection of DFU.

Pre-eclampsia: pathophysiology and clinical implications

Pre-eclampsia is a common disorder that particularly affects first pregnancies. The clinical presentation is highly variable but hypertension and proteinuria are usually seen. These systemic signs arise from soluble factors released from the placenta as a result of a response to stress of syncytiotrophoblast. There are two sub-types: early and late onset pre-eclampsia, with others almost certainly yet to be identified. Early onset pre-eclampsia arises owing to defective placentation, whilst late onset pre-eclampsia may center around interactions between normal senescence of the placenta and a maternal genetic predisposition to cardiovascular and metabolic disease. The causes, placental and maternal, vary among individuals. Recent research has focused on placental-uterine interactions in early pregnancy. The aim now is to translate these findings into new ways to predict, prevent, and treat pre-eclampsia.

The two-stage placental model of preeclampsia: An update

Early-onset preeclampsia has been linked to poor placentation and fetal growth restriction, whereas late-onset preeclampsia was suggested to result from maternal factors. We have proposed an alternative model, suggesting that both early- and late-onset preeclampsia result from placental syncytiotrophoblast stress. This stress represents a common endpoint of several Stage 1 processes, promoting the clinical stage 2 of preeclampsia (new-onset hypertension and proteinuria or other signs of end-organ dysfunction), but the causes and timing of placental malperfusion differ. We have suggested that late-onset preeclampsia, without evidence of poor spiral artery remodelling, may be secondary to intraplacental (intervillous) malperfusion due to mechanical restrictions. As the growing placenta reaches its size limit, malperfusion and hypoxia occurs. This latter pathway reflects what is observed in postmature or multiple pregnancies. Our revised two-stage model accommodates most risk factors for preeclampsia including primiparity, chronic pre-pregnancy disease (e.g. obesity, diabetic-, chronic hypertensive-, and some autoimmune diseases), and pregnancy risk factors (e.g. multiple or molar pregnancies, gestational diabetes or hypertension, and low circulating Placental Growth Factor). These factors may increase the risk of progressing to the second stage of preeclampsia (both early- and late-onset) by affecting one of or both pathways leading to Stage 1, as well as potentially accelerating the steps towards Stage 2, including priming the maternal cardiovascular susceptibility to inflammatory factors shed by the placenta. This paper reviews previous preeclampsia findings and concepts, which fit with the revised two-stage model, and argues that "maternal" preeclampsia does not exist, as all preeclampsia requires a placenta.

The prediction of early preeclampsia: Results from a longitudinal proteomics study

OBJECTIVES

To identify maternal plasma protein markers for early preeclampsia (delivery <34 weeks of gestation) and to determine whether the prediction performance is affected by disease severity and presence of placental lesions consistent with maternal vascular malperfusion (MVM) among cases.

STUDY DESIGN

This longitudinal case-control study included 90 patients with a normal pregnancy and 33 patients with early preeclampsia. Two to six maternal plasma samples were collected throughout gestation from each woman. The abundance of 1,125 proteins was measured using high-affinity aptamer-based proteomic assays, and data were modeled using linear mixed-effects models. After data transformation into multiples of the mean values for gestational age, parsimonious linear discriminant analysis risk models were fit for each gestational-age interval (8-16, 16.1-22, 22.1-28, 28.1-32 weeks). Proteomic profiles of early preeclampsia cases were also compared to those of a combined set of controls and late preeclampsia cases (n = 76) reported previously. Prediction performance was estimated via bootstrap.

RESULTS

We found that 1) multi-protein models at 16.1-22 weeks of gestation predicted early preeclampsia with a sensitivity of 71% at a false-positive rate (FPR) of 10%. High abundance of matrix metalloproteinase-7 and glycoprotein IIbIIIa complex were the most reliable predictors at this gestational age; 2) at 22.1-28 weeks of gestation, lower abundance of placental growth factor (PlGF) and vascular endothelial growth factor A, isoform 121 (VEGF-121), as well as elevated sialic acid binding immunoglobulin-like lectin 6 (siglec-6) and activin-A, were the best predictors of the subsequent development of early preeclampsia (81% sensitivity, FPR = 10%); 3) at 28.1-32 weeks of gestation, the sensitivity of multi-protein models was 85% (FPR = 10%) with the best predictors being activated leukocyte cell adhesion molecule, siglec-6, and VEGF-121; 4) the increase in siglec-6, activin-A, and VEGF-121 at 22.1-28 weeks of gestation differentiated women who subsequently developed early preeclampsia from those who had a normal pregnancy or developed late preeclampsia (sensitivity 77%, FPR = 10%); 5) the sensitivity of risk models was higher for early preeclampsia with placental MVM lesions than for the entire early preeclampsia group (90% versus 71% at 16.1-22 weeks; 87% versus 81% at 22.1-28 weeks; and 90% versus 85% at 28.1-32 weeks, all FPR = 10%); and 6) the sensitivity of prediction models was higher for severe early preeclampsia than for the entire early preeclampsia group (84% versus 71% at 16.1-22 weeks).

CONCLUSION

We have presented herein a catalogue of proteome changes in maternal plasma proteome that precede the diagnosis of preeclampsia and can distinguish among early and late phenotypes. The sensitivity of maternal plasma protein models for early preeclampsia is higher in women with underlying vascular placental disease and in those with a severe phenotype.

Increased soluble fms-like tyrosine kinase 1 after ischemia reperfusion contributes to adverse clinical outcomes following kidney transplantation

Renal ischemia reperfusion injury (IRI) adversely affects clinical outcomes following kidney transplantation. Understanding the cellular mechanisms and the changes in gene/protein expression following IRI may help to improve these outcomes. Serum soluble fms-like tyrosine kinase 1 (sFlt-1), a circulating antiangiogenic protein, is increased in the first week following kidney transplantation. We evaluated the casual relationship of elevated sFlt-1 levels with renal microvascular dysfunction following IRI in a longitudinal study of 93 kidney transplant recipients and in several animal models. Transplant recipients with higher sFlt-1 levels had higher odds of delayed graft function, graft rejection, impaired graft function, and death. In a subgroup of 25 participants who underwent kidney biopsy within 4 months of kidney transplantation, peritubular capillary area was lower in those with elevated serum sFtl-1 levels. The administration of recombinant sFlt-1 into rodents resulted in significant structural and functional changes of the renal microvasculature, including reduced peritubular capillary density and intracapillary blood volume, and lead to increased expression of inflammatory genes and increased fibrosis. In a murine model of IRI, the kidney was a site of sFlt-1 production, and systemic neutralization of sFlt-1 preserved peritubular capillary density and alleviated renal fibrosis. Our data indicate that high sFlt-1 levels after IRI play an important role in the pathogenesis of microvascular dysfunction, thereby contributing to adverse clinical outcomes following kidney transplantation.

Endothelial dysfunction in pregnancy metabolic disorders

In recent years, the vascular endothelium has gained attention as a key player in the initiation and development of pregnancy disorders. Endothelium acts as an endocrine organ that preserves the homeostatic balance by responding to changes in metabolic status. However, in metabolic disorders, endothelial cells adopt a dysfunctional function, losing their normal responsiveness. During pregnancy, several metabolic changes occur, in which endothelial function decisively participates. Similarly, when pregnancy metabolic disorders occur, endothelial dysfunction plays a key role in pathogenesis. This review outlines the main findings regarding endothelial dysfunction in three main metabolic pathological conditions observed during pregnancy: gestational diabetes, hypertensive disorders, and obesity and hyperlipidemia. Organ, histological and cellular characteristics were thoroughly described. Also, we focused in discussing the underlying molecular mechanisms involved in the cellular signaling pathways that mediate responses in these pathological conditions.

Galectin-9 Alleviates LPS-Induced Preeclampsia-Like Impairment in Rats via Switching Decidual Macrophage Polarization to M2 Subtype

Dysfunction of decidual macrophages (DMs) is considered a critical event in the pathogenesis of pre-eclampsia (PE). T cell immunoglobulin mucin 3 (Tim-3) is an important negative regulatory molecule that induces immune tolerance by interacting with its ligand Galectin-9 (Gal-9) and thus modulating function of various immune cells, including macrophages. However, the regulatory effects of Tim-3/Gal-9 signaling on DMs polarization and its role in PE remain unclear. In this study, we established a PE-like rat model by administering 1.0 μg/kg lipopolysaccharide (LPS) to normal pregnant Sprague-Dawley rats via the tail vein at embryonic day 5 (E5). Apart from the pre-eclamptic manifestations, increased M1 subtype and decreased M2 subtype were observed at the maternal-fetal interface, as well as increased pro-inflammatory cytokines (TNF-α and IL-1β) and reduced anti-inflammatory cytokines (TGF-β and IL-10). Moreover, the expression of Tim-3 in DMs and that of Gal-9 at the maternal-fetal interface were reduced. After administration of recombinant Galectin-9 (rGal-9) protein, we found that liver and renal injuries and maternofetal placental functional deficiency, including inadequate trophoblast cells invasion, impaired spiral artery remodeling and fetal capillary development, were reversed. In addition, the polarization of DMs was inclined to M2 subtype, which was similar to the polarization of DMs in the control rats but contrary to the PE-like rats. Interestingly, at E9, the expression of Tim-3 in DMs and that of Gal-9 at the maternal-fetal interface were significantly increased in the rGal-9 protein intervention group. Taken together, our findings show that administration of rGal-9 protein can alleviate the PE-like rat manifestations induced by LPS. This finding may be related to the activation of the Tim-3/Gal-9 signaling pathway, which promotes DMs polarization dominantly shifting to M2 subtype. Moreover, upregulation of Tim-3 in DMs and Gal-9 at the maternal-fetal interface at E9 suggests that Tim-3/Gal-9 pathway may play some important roles in early pregnancy and even embryo development.