Activation of NF-kappaB and expression of COX-2 in association with neutrophil infiltration in systemic vascular tissue of women with preeclampsia

NFĸB and its inhibitors in preeclampsia: mechanisms and potential interventions

Preeclampsia (PE), which affects between 2 and 15% of pregnancies, is one of the most often reported prenatal problems. It is defined as gestational hypertension beyond 20 weeks of pregnancy, along with widespread edema or proteinuria and specific types of organ damage. PE is characterized by increased levels and activation of nuclear factor kappa B (NF-κB) in the mother's blood and placental cells. This factor controls over 400 genes linked to inflammatory, apoptotic, angiogenesis, and cellular responses to hypoxia and oxidative stress. In the final stages of physiological pregnancy, NF-κB levels need to be lowered to favor maternal immunosuppressive events and continue gestation to prevent hypoxia and inflammation, which are advantageous for implantation. Pharmacotherapy is thought to be a potential treatment for PE by downregulating NF-κB activation. NF-κB activity has been discovered to be regulated by several medications used for both prevention and treatment of PE. However, in order to guarantee treatment safety and effectiveness, additional creativity is desperately required. This article provides an overview of the current understanding of the defined function of NF-κB in PE progression. According to their effect on the cellular control of NF-κB pathways, newly proposed compounds for preventing and treating PE have also been emphasized.

DOCK1 deficiency drives placental trophoblast cell dysfunction by influencing inflammation and oxidative stress, hallmarks of preeclampsia

Preeclampsia (PE) is a globally prevalent obstetric disorder, pathologically characterized by abnormal placental development. Dysfunctions of angiogenesis, vasculogenesis and spiral artery remodeling are demonstrated to be involved in PE pathogenesis; however, the underlying mechanisms remain largely unknown. Here, we investigated the role of the dedicator of cytokinesis 1 (DOCK1), crucial molecule in various cellular processes, in PE progression using HTR-8 cells derived from first-trimester placental extravillous trophoblasts. Our analysis revealed an aberrant DOCK1 expression in the placental villi of PE patients and its impact on essential cellular functions for vascular network formation. A deficiency of DOCK1 in HTR-8 cells impaired the vascular network formation, exacerbated the expression of anti-angiogenic factor ENG, and reduced VEGF levels. Moreover, DOCK1 knockout amplified apoptosis, as indicated by an altered BCL2: BAX ratio and enhanced levels of cleaved PARP. DOCK1 depletion also boosted NF-κB activation and pro-inflammatory cytokine production (IL-6 and TNF-α). Furthermore, the mice treated with DOCK1 inhibitor, TBOPP, exhibited PE-like symptoms. These findings highlight the multifaceted roles of DOCK1 in the pathophysiology of PE, demonstrating that its deficiency can lead to placental dysfunction by orchestrating inflammatory responses and oxidative stress. These insights emphasize the pathogenic role of DOCK1 in PE development and suggest potential treatment strategies that require further exploration. In the graphical abstract, a split image of placental villi contrasts the effects of normal and reduced DOCK1 expression on preeclampsia. The left side illustrates adequate DOCK1 levels supporting healthy trophoblast function and effective spiral artery remodeling. The right side highlights the consequences of DOCK1 deficiency, leading to trophoblast dysfunction and impaired spiral artery remodeling, accompanied by angiogenic imbalance, increased inflammation, oxidative stress, and apoptosis, contributing to placental dysfunction and the development of preeclampsia.

Placental Senescence and the Two-Stage Model of Preeclampsia

In this review, we summarize how an increasingly stressed and aging placenta contributes to the maternal clinical signs of preeclampsia, a potentially lethal pregnancy complication. The pathophysiology of preeclampsia has been conceptualized in the two-stage model. Originally, highlighting the importance of poor placentation for early-onset preeclampsia, the revised two-stage model explains late-onset preeclampsia as well, which is often preceded by normal placentation. We discuss how cellular senescence in the placenta may fit with the framework of the revised two-stage model of preeclampsia pathophysiology and summarize potential cellular and molecular mechanisms, including effects on placental and maternal endothelial function. Cellular senescence may occur in response to inflammatory processes and oxidative, mitochondrial, or endoplasmic reticulum stress and chronic stress induce accelerated, premature placental senescence. In preeclampsia, both circulating and tissue-based senescence markers are present. We suggest that aspirin prophylaxis, commonly recommended from the first trimester onward for women at risk of preeclampsia, may affect placentation and possibly mechanisms of placental senescence, thus attenuating the risk of preeclampsia developing clinically. We propose that biomarkers of placental dysfunction and senescence may contribute to altered preventive strategies, including discontinuation of aspirin at week 24-28 depending on placenta-associated biomarker risk stratification.

Targeting Neutrophil Extracellular Trap Formation: Exploring Promising Pharmacological Strategies for the Treatment of Preeclampsia

Neutrophils, which constitute the most abundant leukocytes in human blood, emerge as crucial players in the induction of endothelial cell death and the modulation of endothelial cell responses under both physiological and pathological conditions. The hallmark of preeclampsia is endothelial dysfunction induced by systemic inflammation, in which neutrophils, particularly through the formation of neutrophil extracellular traps (NETs), play a pivotal role in the development and perpetuation of endothelial dysfunction and the hypertensive state. Considering the potential of numerous pharmaceutical agents to attenuate NET formation (NETosis) in preeclampsia, a comprehensive assessment of the extensively studied candidates becomes imperative. This review aims to identify mechanisms associated with the induction and negative regulation of NETs in the context of preeclampsia. We discuss potential drugs to modulate NETosis, such as NF-κβ inhibitors, vitamin D, and aspirin, and their association with mutagenicity and genotoxicity. Strong evidence supports the notion that molecules involved in the activation of NETs could serve as promising targets for the treatment of preeclampsia.

Luteolin prevents TNF-α-induced NF-κB activation and ROS production in cultured human placental explants and endothelial cells

INTRODUCTION

Preeclampsia (PE) is a serious hypertensive pregnancy disorder and a leading cause of maternal and perinatal morbidity and mortality. Despite the prevalence and complications, there are no approved therapeutics to relieve PE symptoms. Inflammation, oxidative stress, and angiogenic imbalance have been shown to contribute to the PE pathophysiology, though there is a lack of understanding in how best to target these pathways in PE. We recently demonstrated that the bioflavonoid luteolin is a potent inhibitor of the anti-angiogenic and pro-hypertensive soluble fms-like tyrosine kinase 1 (sFlt-1), and here we aimed to determine if luteolin was also capable of reducing inflammation and oxidative stress pathways.

METHODS

Tumor necrosis factor (TNF)-α, which is upregulated in PE, was utilized to stimulate these pathways in human placental explants and endothelial cells. Endothelin-1 (ET-1) and interleukin (IL)-6 in the media from explants and cells were measured via ELISA, and NF-κB localization and reactive oxygen species were detected via fluorescence microscopy.

RESULTS

Pretreatment with luteolin demonstrated significant reductions in NF-κB activation, reactive oxygen species, superoxide, and IL-6 and ET-1 expression in endothelial cells. We also saw a significant reduction in phosphorylation of NF-κB in human placental explants.

DISCUSSION

These data demonstrate that luteolin inhibits pathways implicated in the development of PE and should be explored further for its potential as a PE therapeutic.

Obesity Correlates with Chronic Inflammation of the Innate Immune System in Preeclampsia and HELLP Syndrome during Pregnancy

HELLP syndrome is characterized by hemolysis, elevated liver enzymes, and a low platelet count and poses an increased risk to the pregnant woman and the unborn child. Individual risk factors such as obesity may alter immunocompetence and influence the course of preeclampsia (PE) or HELLP syndrome. Blood samples were collected from 21 pregnant women (7 healthy, 6 with PE, and 8 with HELLP syndrome) and polymorphonuclear neutrophils (PMNs) were subsequently isolated. Production of radical oxygen species (ROS), cell movement, and NETosis were assessed by live-cell imaging. Surface protein expression and oxidative burst were analyzed by flow cytometry. PE and HELLP patients had significantly higher BMI compared to the healthy control group. Depending on the expression of CD11b, CD62L, and CD66b on PMNs, a surface protein activation sum scale (SPASS) was calculated. PMNs from patients with high SPASS values showed prolonged and more targeted migration with delayed ROS production and NETosis. Obesity is associated with a chronic inflammatory state, which in combination with immunological triggers during pregnancy could modulate PMN functions. Pregnant women with higher BMI tend to have higher SPASS values, indicating activation of the innate immune system that could co-trigger PE or HELLP syndrome.

Integrated bioinformatic analysis reveals NOS2 as a novel ferroptosis-related biomarker for pre-eclampsia

BACKGROUND

Pre-eclampsia (PE) is a common condition in pregnancy; however, methods for early diagnosis and effective treatment options are lacking. Ferroptosis is a newly identified iron-dependent cell death pathway. The aim of this study was to investigate the role of ferroptosis-related genes in PE, the underlying mechanism, and their potential diagnostic value using a bioinformatics approach.

METHODS

We downloaded the GSE48424 and GSE98224 datasets from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between PE and healthy pregnancy samples were identified in the GSE48424 dataset and subjected to weighted gene co-expression network analysis; the most relevant modules were intersected with known ferroptosis-related genes to distinctly identify the role of ferroptosis in PE. We further searched transcription factors and microRNAs that are predicted to regulate these ferroptosis-related genes, and patients in the GSE48424 dataset were divided into two groups according to high or low expression of the key ferroptosis-related genes associated with PE. To obtain robust key ferroptosis-related genes in PE, we validated their expression levels in the external dataset GSE98224. Finally, the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay was utilized to access the expression of these genes in the PE and normal blood samples.

RESULTS

Six ferroptosis-related genes involved in PE were obtained by overlapping 3661 genes most associated with PE, 565 DEGs between PE and normal samples, and 259 known ferroptosis-related genes. Among these genes, patients with PE displaying lower expression levels of NOS2 and higher expression levels of PTGS2 had a higher ferroptosis potential index. The expression pattern of NOS2 was consistent in the GSE48424 and GSE98224 datasets. RT-qPCR data confirmed that NOS2 expression was more significantly elevated in patients with PE than in those with a normal pregnancy.

CONCLUSIONS

Our study explored the diagnostic value of ferroptosis-related genes in PE, and identified NOS2 as the key gene linking ferroptosis and PE, suggesting a new candidate biomarker for early PE diagnosis.

Gestational low dietary protein induces intrauterine inflammation and alters the programming of adiposity & insulin sensitivity in the adult offspring

Malnutrition associated with low dietary protein can induce gestational inflammation and sets a long-lasting metabolic impact on the offspring even after replenishment. The work investigated whether a low-protein diet (LPD) during pregnancy and lactation induces intrauterine inflammation and predisposes offspring to adiposity and insulin resistance in their adult life. Female Golden Syrian hamsters were fed LPD (10.0% energy from protein) or a control diet (CD, 20.0 % energy from protein) from preconception until lactation. All pups were switched to CD after lactation and continued until the end. Maternal LPD increased intrauterine inflammation by enhancing neutrophil infiltration, amniotic hsCRP, oxidative stress, and mRNA expression of NFκβ, IL8, COX2, and TGFβ in the chorioamniotic membrane (P<.05). The prepregnancy body weight, placental, and fetal weights, serum AST and ALT were decreased, while blood platelets, lymphocytes, insulin, and HDL were significantly increased in LPD-fed dams (P<.05). A postnatal switch to an adequate protein could not prevent hyperlipidemia in the 6-months LPD/CD offspring. The lipid profile and liver functions were restored over 10 months of protein feeding but failed to normalize fasting glucose and body fat accumulation compared to CD/CD. LPD/CD showed elevated GLUT4 expression & activated pIRS1 in the skeletal muscle and increased expression of IL6, IL1β, and p65-NFκB proteins in the liver (P<.05). In conclusion, present data suggest that maternal protein restriction may induce intrauterine inflammation and affect liver inflammation in the adult offspring by an influx of fats from adipose that may alter lipid metabolism and reduce insulin sensitivity in skeletal muscle.

Neutrophil-to-lymphocyte ratio (NLR) as a predictive index for liver and coagulation dysfunction in preeclampsia patients

BACKGROUND

Pre-eclampsia (PE) is a pregnancy disorder that is related to an enhanced immune response. Immune cell characteristics such as neutrophil or monocyte to lymphocyte ratios (NLR, MLR) are known to be related to kidney and liver dysfunction in hypertensive patients. Here, we aimed to analyze the correlations between NLR, MLR and platelet to lymphocyte ratio (PLR) and liver, renal and coagulation functional parameters and the impacts of these immune cell profiles to the prognostic significance in PE patients.

METHODS

Pre-delivery hematological and biochemical parameters of 320 first-time pregnant women registered at the Obstetrics Department of Yanbian University Hospital from 2016 to 2019 were analyzed retrospectively. Patients were divided into normal pregnancy (normal, n = 161), mild PE (mPE, n = 28) and severe PE (sPE, n = 131) groups according to diagnostic criteria. Pearson correlation analysis were performed and area under the curve (AUC) were conducted for the diagnostic values of NLR, MLR and PLR. Results were validated with data from the Department of Obstetrics and Gynecology of Seoul National University Hospital (SNUH).

RESULTS

Kidney functional indexes were adversative in mPE and sPE and liver and coagulation indexes were worse in sPE compared to normal groups. Among immune cells, lymphocytes were increased in mPE and sPE patients, resulted in reduced NLR, MLR and PLR in PE groups, more significant difference were shown in sPE. NLR and PLR were associated with CREA and/or BUN negatively and positive associations were observed with total protein (TP) and albumin (ALB) in sPE. Only NLR showed positive associations with coagulation indexes (PT and APTT) in sPE. AUC analysis for NLR, MLR and PLR were 0.700, 0.656, 0.643, respectively, and NLR < 3.7 predicted hypertension (95% CI in all participants: 0.647-0.749, p < 0.001). Blood pressure, liver, kidney and coagulation indexes were worse at cut off value (NLR < 3.7), and this was validated with the data from SNUH.

CONCLUSION

NLR could be used as an independent predictor of liver and coagulation dysfunction in PE patients. Our results may provide non-invasive and efficient way of the risk assessment among PE patients.

Aspirin Inhibits the Inflammatory Response of Protease-Activated Receptor 1 in Pregnancy Neutrophils: Implications for Treating Women with Preeclampsia

Neutrophils expressing cyclooxygenase-2 (COX-2) extensively infiltrate maternal blood vessels in preeclampsia, associated with vascular inflammation. Because pregnancy neutrophils also express protease-activated receptor 1 (PAR-1, F2R thrombin receptor), which they do not in non-pregnant subjects, they can be activated by proteases. We tested the hypothesis that aspirin at a dose sufficient to inhibit COX-2 would reduce inflammatory responses in preeclampsia neutrophils. Neutrophils were isolated from normal pregnant and preeclamptic women at approximately 30 weeks' gestation. Normal pregnancy neutrophils were treated with elastase, a protease elevated in preeclampsia, or elastase plus aspirin to inhibit COX-2, or elastase plus pinane thromboxane, a biologically active structural analog of thromboxane and a thromboxane synthase inhibitor. Preeclamptic pregnancy neutrophils were treated with the same doses of aspirin or pinane thromboxane. Confocal microscopy with immunofluorescence staining was used to determine the cellular localization of the p65 subunit of nuclear factor-kappa B (NF-κB) and media concentrations of thromboxane were measured to evaluate the inflammatory response. In untreated neutrophils of normal pregnant women, p65 was localized to the cytosol. Upon stimulation with elastase, p65 translocated from the cytosol to the nucleus coincident with increased thromboxane production. When neutrophils were co-treated with aspirin or pinane thromboxane, elastase was not able to cause nuclear translocation of p65 or increase thromboxane. In untreated neutrophils of preeclamptic women, the p65 subunit was present in the nucleus and thromboxane production was elevated, but when preeclamptic neutrophils were treated with aspirin or pinane thromboxane, p65 was cleared from the nucleus and returned to the cytosol along with decreased thromboxane production. These findings suggest that COX-2 is a downstream mediator of PAR-1 and demonstrate that PAR-1- mediated inflammation can be inhibited by aspirin. Given the extensive and ubiquitous expression of PAR-1 and COX-2 in preeclamptic women, consideration should be given to treating women with preeclampsia using a dose of aspirin sufficient to inhibit COX-2.

Bioinformatics methods in biomarkers of preeclampsia and associated potential drug applications

Background

Preeclampsia is a pregnancy-related condition that causes high blood pressure and proteinuria after 20 weeks of pregnancy. It is linked to increased maternal mortality, organ malfunction, and foetal development limitation. In this view, there is a need critical to identify biomarkers for the early detection of preeclampsia. The objective of this study is to discover critical genes and explore medications for preeclampsia treatment that may influence these genes.

Methods

Four datasets, including GSE10588, GSE25906, GSE48424 and GSE60438 were retrieved from the Gene Expression Omnibus database. The GSE10588, GSE25906, and GSE48424 datasets were then removed the batch effect using the “sva” R package and merged into a complete dataset. The differentially expressed genes (DEGs) were identified using the “limma” R package. The potential small-molecule agents for the treatment of PE was further screened using the Connective Map (CMAP) drug database based on the DEGs. Further, Weight gene Co-expression network (WGNCA) analysis was performed to identified gene module associated with preeclampsia, hub genes were then identified using the logistic regression analysis. Finally, the immune cell infiltration level of genes was evaluated through the single sample gene set enrichment analysis (ssGSEA).

Results

A total of 681 DEGs (376 down-regulated and 305 up-regulated genes) were identified between normal and preeclampsia samples. Then, Dexamethasone, Prednisone, Rimexolone, Piretanide, Trazodone, Buflomedil, Scoulerin, Irinotecan, and Camptothecin drugs were screened based on these DEGs through the CMAP database. Two modules including yellow and brown modules were the most associated with disease through the WGCNA analysis. KEGG analysis revealed that the chemokine signaling pathway, Th1 and Th2 cell differentiation, B cell receptor signalling pathway and oxytocin signalling pathway were significantly enriched in these modules. Moreover, two key genes, PLEK and LEP were evaluated using the univariate and multivariate logistic regression analysis from the hub modules. These two genes were further validated in the external validation cohort GSE60438 and qRT-PCR experiment. Finally, we evaluated the relationship between immune cell and two genes.

Conclusion

In conclusion, the present study investigated key genes associated with PE pathogenesis that may contribute to identifying potential biomarkers, therapeutic agents and developing personalized treatment for PE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08937-3.

Aberrant endothelial expression of hnRNPC1/C2 and VDR and reduced maternal vitamin D levels in women with preeclampsia

Vitamin D deficiency is a widespread health problem globally and vitamin D deficiency/ insufficiency in pregnancy is a risk factor for preeclampsia, a hypertensive disorder in human pregnancy. Vitamin D elicits its biological effects through binding to its receptor VDR. In the present study, we determined maternal vascular expression of VDR and hnRNPC1/C2, a native repressor of VDR, in subcutaneous adipose tissue from women with normal pregnancy and preeclampsia. Maternal antenatal and postnatal vitamin D levels were measured. We found that hnRNPC1/C2 expression was markedly increased, while VDR expression was markedly reduced, in maternal vessel endothelium and smooth muscle cells from women with preeclampsia compared to that from normal pregnant controls. Reduced VDR expression was relevant to low maternal antenatal and postnatal vitamin D levels in women with preeclampsia. Using human umbilical vein endothelial cells (HUVECs) as an endothelial model, we further investigated the role of hnRNPC1/C2-mediated VDR expression in endothelial cells, and tested effect of hnRNPC1/C2 inhibition on endothelial response to bioactive vitamin D, 1,25(OH)₂D₃. Our results showed that inhibition of hnRNPC1/C2 by hnRNPC1/C2 siRNA resulted in not only an increase in endothelial VDR expression, but further improved endothelial response to 1,25(OH)₂D₃. These findings indicate that aberrant hnRNPC1/C2 expression may contribute to reduced vascular expression of VDR in women with preeclampsia and suggest that hnRNPC1/C2 could be a target for improving vascular endothelial cell response to vitamin D.

Gene Expression of Pregnancy Neutrophils Differs for Protease versus Lipopolysaccharide Stimulation

Neutrophils, which extensively infiltrate maternal systemic blood vessels in preeclampsia, express protease-activated receptor 1 (PAR-1) but only during pregnancy. Neutrophils are generally considered to be non-specific in their response, but the pregnancy-specific expression of PAR-1 could result in a gene expression profile unique to pregnancy, which could help explain why the maternal inflammatory response in preeclampsia is systemic rather than localized. We sought to determine if gene expression of pregnancy neutrophils would differ if stimulated by a protease versus bacterial lipopolysaccharide (LPS). We isolated neutrophils from normal pregnant women at 30 weeks’ gestation and cultured them with elastase or LPS. We used elastase because it is a protease elevated in women with preeclampsia, and it activates pregnancy neutrophils via PAR-1. RNA was isolated from the neutrophils for sequencing of the transcriptomes. We discovered many differences in the gene expression profiles. For example, exposure to elastase resulted in three times more uniquely expressed genes than LPS, and the number of significantly differentially upregulated and downregulated genes was greater for elastase. Analysis of canonical pathways revealed similarities for innate immunity but also differences. LPS treatment enriched more pathways, but elastase activated more genes in each pathway. Elastase treatment enriched the MAPK signaling pathway, whereas LPS did not. This is significant because MAPK is a key mediator of transcriptional responses. These findings indicate that protease stimulation of pregnancy neutrophils results in a different profile than stimulation with LPS, which may help explain why the sterile inflammatory response of preeclampsia is systemic and unique to pregnancy.

Pregnancy-specific expression of protease-activated receptor 1: a therapeutic target for prevention and treatment of preeclampsia?

Neutrophils extensively infiltrate maternal blood vessels in preeclampsia. This could explain why multiple organs are affected in this enigmatic disorder. Lipid peroxides produced by the placenta are probably the first factors that activate neutrophils as they circulate through the intervillous space, but then a second factor specific to pregnancy comes into play, protease-activated receptor 1. The only time neutrophils express protease-activated receptor 1 is during pregnancy. This means that neutrophils can be activated by a mechanism specific to pregnancy, that is, by proteases. Two proteases that are elevated in preeclampsia and activate protease-activated receptor 1 are matrix metalloproteinase-1 and neutrophil elastase. There is an 8-fold increase in vascular protease-activated receptor 1 expression in women with preeclampsia, and protease-activated receptor 1 is also expressed on the placenta, a pregnancy-specific tissue. The question arises if the pregnancy-specific expression of protease-activated receptor 1 is essential to the pathophysiology of preeclampsia. Protease activation of protease-activated receptor 1 in neutrophils of women with normal pregnancies causes activation of RhoA kinase. RhoA kinase phosphorylates nuclear factor-kappa B causing its translocation from the cytosol into the nucleus, increasing the expression of inflammatory genes. This signaling pathway is blocked by inhibition of either protease-activated receptor 1 or RhoA kinase activity. In contrast, neutrophils obtained from preeclamptic women are already activated, with nuclear factor-kappa B localized in the nucleus. Surprisingly, inhibition of either protease-activated receptor 1 or RhoA kinase results in an efflux of nuclear factor-kappa B from the nucleus back into the cytoplasm. Cyclooxygenase-2 seems to be a downstream mediator between protease-activated receptor 1 and RhoA kinase because aspirin inhibits the nuclear translocation of nuclear factor-kappa B and inhibits neutrophil production of superoxide, thromboxane, and tumor necrosis factor alpha. Currently, low-dose aspirin is the standard of care to prevent preeclampsia in high-risk women. Generally, the actions of low-dose aspirin are attributed to selective inhibition of maternal platelet thromboxane production. However, a recent study showed that beneficial effects extend to the placenta, where aspirin corrected the imbalance of increased thromboxane and reduced prostacyclin and oxidative stress. Selective inhibition of placental thromboxane is possible because thromboxane and prostacyclin are compartmentalized. Thromboxane is produced by trophoblast cells and prostacyclin by endothelial cells, so as aspirin crosses the placenta, its levels decline, sparing prostacyclin. Placental oxidative stress is attenuated because cyclooxygenase-2 inhibition decreases the generation of reactive oxygen species to decrease the formation of isoprostanes. The clinical manifestations of preeclampsia can be explained by protease activation of protease-activated receptor 1 in different tissues. In neutrophils, it can account for their activation and inflammatory response. In vascular tissue, protease-activated receptor 1 activation leads to enhanced vascular reactivity to angiotensin II to cause hypertension. In the placenta, it leads to oxidative stress, increased soluble fms-like tyrosine kinase, and thromboxane production. Activation of protease-activated receptor 1 on endothelial cells causes contraction, leading to edema and proteinuria, and activation on platelets leads to coagulation abnormalities. As proteases that activate protease-activated receptor 1 are elevated in the circulation of women with preeclampsia, consideration should be given to the inhibition of protease-activated receptor 1 as a treatment. Recently, The Food and Drug Administration (FDA) approved a protease-activated receptor 1 inhibitor, creating an opportunity to test whether protease-activated receptor 1 inhibition can prevent and/or treat preeclampsia, but a standard dose of aspirin might be just as effective by blocking its downstream actions.

Epigenetic Regulation of Interleukin-17-Related Genes and Their Potential Roles in Neutrophil Vascular Infiltration in Preeclampsia

DNA methylation is an epigenetic mechanism controlling gene expression, and reduced methylation is associated with increased gene expression. We hypothesized that IL-17 cytokines are regulated by DNA methylation, are elevated in the circulation of preeclamptic women, and stimulate vascular neutrophil chemokine expression, which could account for vascular infiltration of neutrophils in preeclampsia. We found significantly reduced DNA methylation of IL17A, IL17E, and IL17F genes in omental arteries of preeclamptic women, significantly reduced methylation of IL2, which regulates IL-17-producing T-lymphocytes, and significantly reduced methylation of genes encoding neutrophil chemokines and TNFα receptors related to lymphocyte function. Maternal plasma levels of IL-17A were significantly elevated in the second trimester of preeclamptic pregnancy as compared to normal pregnancy. To test if methylation regulates IL-17 cytokines, a lymphocyte cell line (Jurkat) was cultured with a hypomethylating agent. Hypomethylation increased expression of IL17E (aka IL25), IL17F, and IL2. IL17A was not expressed by Jurkat cells. To test the potential role of IL-17 cytokines in vascular neutrophil infiltration associated with preeclampsia, human vascular smooth muscle cells were cultured with IL-17 cytokines. IL-17A, but not IL-17E or IL-17F, increased gene expression of neutrophil chemokines (IL-8, CXCL5, and CXCL6) that are increased in vascular smooth muscle of preeclamptic women. The monocyte chemokine, CCL-2, was not increased. TNFα also increased neutrophil chemokines. IL-17 cytokines are regulated by DNA methylation; IL-17A is elevated in preeclampsia and stimulates expression of neutrophil chemokines in vascular smooth muscle. IL-17A could be responsible for vascular infiltration of neutrophils in preeclampsia.

Cellular immune responses in the pathophysiology of preeclampsia

Preeclampsia, defined as new-onset hypertension accompanied by proteinuria occurring at 20 weeks of gestation or later, is a leading cause of perinatal morbidity and mortality worldwide. The pathophysiology of this major multi-systemic syndrome includes defective deep placentation, oxidative stress, endothelial dysfunction, the presence of an anti-angiogenic state, and intravascular inflammation, among others. In this review, we provide a comprehensive overview of the cellular immune responses involved in the pathogenesis of preeclampsia. Specifically, we summarize the role of innate and adaptive immune cells in the maternal circulation, reproductive tissues, and at the maternal-fetal interface of women affected by this pregnancy complication. The major cellular subsets involved in the pathogenesis of preeclampsia are regulatory T cells, effector T cells, NK cells, monocytes, macrophages, and neutrophils. We also summarize the literature on those immune cells that have been less characterized in this clinical condition, such as γδ T cells, invariant natural killer T cells, dendritic cells, mast cells, and B cells. Moreover, we discuss in vivo studies utilizing a variety of animal models of preeclampsia to further support the role of immune cells in this disease. Finally, we highlight the existing gaps in knowledge of the immunobiology of preeclampsia that require further investigation. The goal of this review is to promote translational research leading to clinically relevant strategies that can improve adverse perinatal outcomes resulting from the obstetrical syndrome of preeclampsia.

Patterns of Maternal Neutrophil Gene Expression at 30 Weeks of Gestation, but Not DNA Methylation, Distinguish Mild from Severe Preeclampsia

Neutrophils are activated and extensively infiltrate blood vessels in preeclamptic women. To identify genes that contribute to neutrophil activation and infiltration, we analyzed the transcriptomes of circulating neutrophils from normal pregnant and preeclamptic women. Neutrophils were collected at 30 weeks’ gestation and RNA and DNA were isolated for RNA sequencing and 5-hydroxy-methylcytosine (5-hmC) sequencing as an index of dynamic changes in neutrophil DNA methylation. Women with normal pregnancy who went on to develop mild preeclampsia at term had the most uniquely expressed genes (697) with 325 gene ontology pathways upregulated, many related to neutrophil activation and function. Women with severe preeclampsia who delivered prematurely had few pathways up- or downregulated. Cluster analysis revealed that gene expression in women with severe preeclampsia was an inverse mirror image of gene expression in normal pregnancy, while gene expression in women who developed mild preeclampsia was remarkably different from both. DNA methylation marks, key regulators of gene expression, are removed by the action of ten-eleven translocation (TET) enzymes, which oxidize 5-methylcytosines (5mCs), resulting in locus-specific reversal of DNA methylation. DNA sequencing for 5-hmC revealed no differences among the three groups. Genome-wide DNA methylation revealed extremely low levels in circulating neutrophils suggesting they are de-methylated. Collectively, these data demonstrate that neutrophil gene expression profiles can distinguish different preeclampsia phenotypes, and in the case of mild preeclampsia, alterations in gene expression occur well before clinical symptoms emerge. These findings serve as a foundation for further evaluation of neutrophil transcriptomes as biomarkers of preeclampsia phenotypes. Changes in DNA methylation in circulating neutrophils do not appear to mediate differential patterns of gene expression in either mild or severe preeclampsia.

Modulation of preeclampsia by the cholinergic anti-inflammatory pathway: Therapeutic perspectives

The cholinergic anti-inflammatory pathway (CAP) is vital for the orchestration of the immune and inflammatory responses under normal and challenged conditions. Over the past two decades, peripheral and central circuits of CAP have been shown to be critically involved in dampening the inflammatory reaction in a wide array of inflammatory disorders. Additionally, emerging evidence supports a key role for CAP in the regulation of the female reproductive system during gestation as well as in the advent of serious pregnancy-related inflammatory insults such as preeclampsia (PE). Within this framework, the modulatory action of CAP encompasses the perinatal maternal and fetal adverse consequences that surface due to antenatal PE programming. Albeit, a considerable gap still exists in our knowledge of the precise cellular and molecular underpinnings of PE/CAP interaction, which hampered global efforts in safeguarding effective preventive or therapeutic measures against PE complications. Here, we summarize reports in the literature regarding the roles of peripheral and reflex cholinergic neuroinflammatory pathways of nicotinic acetylcholine receptors (nAChRs) in reprogramming PE complications in mothers and their progenies. The possible contributions of α7-nAChRs, cholinesterases, immune cells, adhesion molecules, angiogenesis, and endothelial dysfunction to the interaction have also been reviewed.

The Road to Low-Dose Aspirin Therapy for the Prevention of Preeclampsia Began with the Placenta

The road to low-dose aspirin therapy for the prevention of preeclampsia began in the 1980s with the discovery that there was increased thromboxane and decreased prostacyclin production in placentas of preeclamptic women. At the time, low-dose aspirin therapy was being used to prevent recurrent myocardial infarction and other thrombotic events based on its ability to selectively inhibit thromboxane synthesis without affecting prostacyclin synthesis. With the discovery that thromboxane was increased in preeclamptic women, it was reasonable to evaluate whether low-dose aspirin would be effective for preeclampsia prevention. The first clinical trials were very promising, but then two large multi-center trials dampened enthusiasm until meta-analysis studies showed aspirin was effective, but with caveats. Low-dose aspirin was most effective when started <16 weeks of gestation and at doses >100 mg/day. It was effective in reducing preterm preeclampsia, but not term preeclampsia, and patient compliance and patient weight were important variables. Despite the effectiveness of low-dose aspirin therapy in correcting the placental imbalance between thromboxane and prostacyclin and reducing oxidative stress, some aspirin-treated women still develop preeclampsia. Alterations in placental sphingolipids and hydroxyeicosatetraenoic acids not affected by aspirin, but with biologic actions that could cause preeclampsia, may explain treatment failures. Consideration should be given to aspirin's effect on neutrophils and pregnancy-specific expression of protease-activated receptor 1, as well as additional mechanisms of action to prevent preeclampsia.

Vitamin D stimulates miR-26b-5p to inhibit placental COX-2 expression in preeclampsia

Vitamin D insufficiency or deficiency during pregnancy has been associated with an increased risk of preeclampsia. Increased placental cyclooxygenase-2 (COX-2) activity was proposed to contribute to the inflammatory response in preeclampsia. This study was to investigate if vitamin D can benefit preeclampsia by inhibiting placental COX-2 expression. Placenta tissues were obtained from 40 pregnant women (23 normotensive and 17 preeclampsia). miR-26b-5p expression was assessed by quantitative PCR. Vitamin D receptor (VDR) expression and COX-2 expression were determined by immunostaining and Western blot. HTR-8/SVneo trophoblastic cells were cultured in vitro to test anti-inflammatory effects of vitamin D in placental trophoblasts treated with oxidative stress inducer CoCl₂. 1,25(OH)₂D₃ was used as bioactive vitamin D. Our results showed that reduced VDR and miR-26b-5p expression, but increased COX-2 expression, was observed in the placentas from women with preeclampsia compared to those from normotensive pregnant women. Transient overexpression of miR-26b-5p attenuated the upregulation of COX-2 expression and prostaglandin E₂ (PGE₂) production induced by CoCl₂ in placental trophoblasts. 1,25(OH)₂D₃ treatment inhibited CoCl₂-induced upregulation of COX-2 in placental trophoblasts. Moreover, miR-26b-5p expression were significantly upregulated in cells treated with 1,25(OH)₂D₃, but not in cells transfected with VDR siRNA. Conclusively, downregulation of VDR and miR-26b-5p expression was associated with upregulation of COX-2 expression in the placentas from women with preeclampsia. 1,25(OH)₂D₃ could promote miR-26b-5p expression which in turn inhibited COX-2 expression and PGE₂ formation in placental trophoblasts. The finding of anti-inflammatory property by vitamin D through promotion of VDR/miR-26b-5p expression provides significant evidence that downregulation of vitamin D/VDR signaling could contribute to increased inflammatory response in preeclampsia.

New indicators in evaluation of hemolysis, elevated liver enzymes, and low platelet syndrome: A case-control study

BACKGROUND

Indices such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and red cell distribution width (RDW) are considered new markers of the systemic inflammatory response (SIR), and have been widely implemented for the diagnosis of patients with inflammatory diseases. These new indicators have also been widely investigated in preeclampsia (PE) but less analyzed in hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome.

AIM

To compare SIR markers among HELLP patients, PE only patients, and healthy gravidae.

METHODS

This retrospective case-control study enrolled 630 cases, including 210 patients with HELLP syndrome (HELLP group), 210 patients with only PE (PE group) and 210 healthy gravidae (control group). The three groups were matched by age, parity, status of assisted reproduction, and multiple pregnancies. Birthweight, gestational age at complete blood count collection, gestational age at delivery, mode of delivery, etc. were recorded. The main indices as NLR, PLR, MPV, PDW, and RDW among the groups were compared, as well as some secondary outcomes including neutrophil, platelets, and hemoglobin.

RESULTS

The NLR (6.4 vs 4.3 vs 3.5), MPV (11.9 vs 11.2 vs 10.7), PDW (16.4 vs 13.3 vs 14.2), leukocyte (12.4 × 10⁹/L vs 9.7 × 10⁹/L vs 8.7 × 10⁹/L) and neutrophil count (9.9 × 10⁹/L vs 7.3 × 10⁹/L vs 6.1 × 10⁹/L) were highest in the HELLP group, lower in the PE group, and lowest in the control group. Both the overall comparisons between the three groups (all ^bP < 0.01) and pairwise comparisons between every two groups elicited statistically significant differences (all ^dP < 0.01, except control vs PE: ^cP < 0.05 in PDW). The average lymphocyte counts were 1.4 (1.1, 2.0) × 10⁹/L in the HELLP group, 1.6 (1.3, 2.0) × 10⁹/L in the PE group and 1.7 (1.4, 2.0) × 10⁹/L in the control group. The overall comparison of lymphocyte count within the three groups had statistically significant differences (P = 0.000). The pairwise comparisons between every two groups demonstrated that the HELLP group had a lower lymphocyte count than both the PE (P = 0.019) and control groups (P = 0.000), but the difference between the PE and control groups was not statistically significant (P = 0.432). The overall comparisons on platelet counts and the PLR among these three groups also showed statistically significant differences (both P = 0.000), from low to high being those in the HELLP group (43.4 × 10⁹/L, 64.0), control group (180.5 × 10⁹/L, 103.6) and PE group (181.5 × 10⁹/L, 112.8). Pairwise comparisons of neither index displayed statistically significant differences between the PE and control groups (both P > 0.05), while the differences in the two indices between the HELLP group and the two other groups were still statistically significant (all P = 0.000). RDW values were highest in the HELLP group (14.5% [13.6, 15.3]), lower in the control group (14.1% [13.5, 14.8]) and lowest in the PE group (13.9% [13.4, 14.9]). The difference between the PE and control group did not show statistical significance (P = 1.000), while RDW values in the HELLP group were higher than those in the other two groups (^cP < 0.05 vs control, ^dP < 0.01 vs PE).

CONCLUSION

SIR markers such as NLR, RDW, MPV, and PDW were increased and PLR was decreased in HELLP. These SIR markers may become new indicators in the evaluation of HELLP syndrome.

MicroRNA-138 improves LPS-induced trophoblast dysfunction through targeting RELA and NF-κB signaling

Preeclampsia is a pregnancy complication classified by new onset of elevated blood pressure and proteinuria after 20 weeks of gestation. During preeclampsia, extra villous trophoblasts fail to adequately invade the myometrial spiral arteries, leading to incomplete and impaired vessel transformation and initiating or aggravating preeclampsia. Although NF-κB and proinflammatory cytokines have been reported to be related to trophoblast dysfunction, the underlying mechanism remains unclear. Herein, we demonstrated the miR-138/RELA axis modulating the migratory ability, and invasive ability of HTR-8/SVneo and JEG-3 cells, as well as the inflammatory factor levels in response to LPS stimulation. miR-138 expression was upregulated in preeclampsia placenta and LPS-stimulated HTR-8/SVneo and JEG-3 cell lines. miR-138 overexpression rescued the migratory and invasive ability of HTR-8/SVneo and JEG-3 cells inhibited by LPS stimulation, and decreased LPS-induced TNF-α and IL-6 levels. By binding the 3'-UTR of RELA, miR-138 negatively regulated p65 expression. The silencing of p65 also improved LPS-induced HTR-8/SVneo and JEG-3 cell dysfunction and TNF-α and IL-6 levels. More importantly, p65 overexpression partially reversed the functions of miR-138 overexpression upon both cells, indicating that miR-138 exerted its biological effects through targeting RELA. In conclusion, miR-138 improves LPS-induced inflammation and oxidative stress on trophoblasts through targeting RELA and affecting NF-κB signaling. The miR-138/RELA axis might be involved in preeclampsia pathogenesis, which requires further in vivo and clinical researches.

Tumor infiltrating neutrophil might play a major role in predicting the clinical outcome of breast cancer patients treated with neoadjuvant chemotherapy

Background

This study was aimed to explore the predictive ability of tumor infiltrating neutrophil (TIN) in patients with breast cancer treated with neoadjuvant chemotherapy (NACT). Furthermore, the significance of TIN’s dynamic change before and after NACT was investigated.

Methods

Between January 2004 and December 2017, a total of 133 patients with breast cancer who underwent NACT before surgery were enrolled in this retrospective cohort. Eighty-nine of them were able to get the core needle biopsy (CNB) samples and all the pathological samples after surgery were available. TIN was detected by immunohistochemical staining of CD66b. The optimal cut-off value was determined via receiver operating characteristic (ROC) curve analysis. The association of clinicopathologic characteristics and chemotherapy efficiency was analyzed using X² test or Fisher’s exact test or t-test as appropriate, and the prognostic significances were assessed by univariate and multivariate analyses.

Results

Patients with higher TIN after NACT were confirmed to be significantly associated with worse prognosis (P = 0.002). After stratifying patients into two groups, high difference group was prone to have better chemotherapy efficiency (P < 0.001) and clinical outcome in both univariate (P = 0.002) and multivariate analyses (P = 0.003).

Conclusions

In this study, higher TIN after NACT was confirmed to be associated with breast cancer patients’ worse chemotherapy efficiency and shorter disease-free survival (DFS). Furthermore, the TIN’s dynamic change before and after NACT was firstly proved to be a more accurate predictive marker compared with TIN after NACT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07789-6.

Proteases Activate Pregnancy Neutrophils by a Protease-Activated Receptor 1 Pathway: Epigenetic Implications for Preeclampsia

We tested a novel hypothesis that elevated levels of proteases in the maternal circulation of preeclamptic women activate neutrophils due to their pregnancy-specific expression of protease-activated receptor 1 (PAR-1). Plasma was collected longitudinally from normal pregnant and preeclamptic women and analyzed for MMP-1 and neutrophil elastase. Neutrophils were isolated for culture and confocal microscopy. Omental fat was collected for immunohistochemistry. Circulating proteases were significantly elevated in preeclampsia. Confocal microscopy revealed that tet methylcytosine dioxygenase 2 (TET2), a DNA de-methylase, and p65 subunit of NF-κB were strongly localized to the nucleus of untreated neutrophils of preeclamptic women, but in untreated neutrophils of normal pregnant women they were restricted to the cytosol. Treatment of normal pregnancy neutrophils with proteases activated PAR-1, leading to activation of RhoA kinase (ROCK), which triggered translocation of TET2 and p65 from the cytosol into the nucleus, mimicking the nuclear localization in neutrophils of preeclamptic women. IL-8, an NF-κB-regulated gene, increased in association with TET2 and p65 nuclear localization. Co-treatment with inhibitors of PAR-1 or ROCK prevented nuclear translocation and IL-8 did not increase. Treatment of preeclamptic pregnancy neutrophils with inhibitors emptied the nucleus of TET2 and p65, mimicking the cytosolic localization of normal pregnancy neutrophils. Expression of PAR-1 and TET2 were markedly increased in omental fat vessels and neutrophils of preeclamptic women. We conclude that elevated levels of circulating proteases in preeclamptic women activate neutrophils due to their pregnancy-specific expression of PAR-1 and speculate that TET2 DNA de-methylation plays a role in the inflammatory response.

The Role of NFκB in Healthy and Preeclamptic Placenta: Trophoblasts in the Spotlight

The NFκB protein family regulates numerous pathways within the cell-including inflammation, hypoxia, angiogenesis and oxidative stress-all of which are implicated in placental development. The placenta is a critical organ that develops during pregnancy that primarily functions to supply and transport the nutrients required for fetal growth and development. Abnormal placental development can be observed in numerous disorders during pregnancy, including fetal growth restriction, miscarriage, and preeclampsia (PE). NFκB is highly expressed in the placentas of women with PE, however its contributions to the syndrome are not fully understood. In this review we discuss the molecular actions and related pathways of NFκB in the placenta and highlight areas of research that need attention.

HSPA1L rs1061581 polymorphism is associated with the risk of preeclampsia in Han Chinese women

Preeclampsia (PE) is an excessive systemic inflammation response with dysfunction of endothelial. As a stress protein, heat shock protein 70 (HSP70) plays a pivotal role in protecting cells against apoptosis, oxidative damage and genetic damage. In humans, three genes encode members of the HSP70 class: HSPA1A, HSPA1B and HSPA1L. Our study was to investigate the association between genetic variations of HSPA1L and the susceptibility for PE in Chinese Han population. The polymorphisms of rs2227956, rs1043618 and rs1061581 in HSPA1L were genotyped by TaqMan allelic discrimination real time polymerase chain reaction (PCR) in 929 PE patients and 1024 healthy pregnant women. Statistic difference of the genotypic and allelic frequencies were found in HSPA1L rs1061581 between PE patients and controls (χ2 = 29.863, P < 0.001 by genotype; χ2 = 27.298, P < 0.001, OR = 1.874, 95%CI 1.476-2.379 by allele) and HSPA1L rs1061581 A alleles occurred more frequently in PE patients compared with healthy controls (PE vs. controls 10.28% vs. 5.76%). Furthermore, we divided the PE cases into early-onset/late-onset PE and mild/severe PE subgroups and found statistical differences in genotypic and allelic frequencies of the HSPA1L rs1061581 between early-onset PE, late-onset PE, mild PE, severe PE and controls, respectively. Moreover, HSPA1L rs1061581 A alleles were more frequent in early-onset PE, late-onset PE, mild PE and severe PE than controls respectively. Therefore, we concluded that HSPA1L rs1061581 polymorphism is associated with the risk of PE in Han Chinese women and A alleles may play a role in the susceptibility for PE.

Protease Amplification of the Inflammatory Response Induced by Commensal Bacteria: Implications for Racial Disparity in Term and Preterm Birth

Decidual macrophages secrete proteases that activate protease-activated receptor 1 (PAR-1). We hypothesized that activation of the inflammatory response by bacteria is amplified by proteases, initiating labor. In addition, we hypothesized that commensal bacteria trigger an inflammatory response by activating NF-κB and TET methylcytosine dioxygenase 2 (TET2), a DNA de-methylase, via a protease amplified PAR-1, RhoA kinase (ROCK) pathway. To evaluate these hypotheses, we compared responses of mononuclear cells with Lactobacillus crispatus, prevalent in the vaginal microbiome of women of European ancestry, with L. iners and Fusobacterium nucleatum, which are more prevalent in vaginal samples collected from African-American women. Decidual tissue was collected at term not-in-labor (TNL), term labor (TL), spontaneous preterm labor (sPTL), and infected preterm labor (iPTL) and immunostained for PAR-1, TET2, and CD14. Mononuclear cells and THP-1 macrophage cells were treated with bacteria and elastase, a known activator of PAR-1. The inflammatory response was monitored by confocal microscopy of TET2 and the p65 subunit of NF-κB, as well as IL-8 production. Decidual staining for PAR-1, TET2, and CD14 increased TNL < TL < sPTL < iPTL. All treatments stimulated translocation of TET2 and p65 from the cytosol to the nucleus and increased IL-8, but L. iners and F. nucleatum caused more robust responses than L. crispatus. Inhibition of PAR-1 or ROCK prevented TET2 and p65 nuclear translocalization and increases in IL-8. Our findings demonstrate that proteases amplify the inflammatory response to commensal bacteria. The more robust response to bacteria prevalent in African-American women may contribute to racial disparities in preterm birth.

Biopolymer-Delivered, Maternally Sequestered NF-κB (Nuclear Factor-κB) Inhibitory Peptide for Treatment of Preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy that causes significant acute and long-term risk to the mother and the baby. The multifaceted maternal syndrome is driven by overproduction of circulating anti-angiogenic factors, widespread inflammation, and endothelial dysfunction. Nuclear factor-κB (NF-κB) is a transcription factor that plays a central role in the inflammatory response. Its activity is increased in the preeclamptic placenta, and it promotes the systemic endothelial dysfunction present in preeclampsia. There is an acute need for new therapeutics targeted to the causative pathways of preeclampsia. Our group has developed a drug delivery system based on the bioengineered protein ELP (elastin-like polypeptide) that is capable of stabilizing therapeutics in the maternal circulation and preventing their placental transfer. Here we used the ELP carrier system to deliver a peptide known to inhibit the NF-κB pathway. This polypeptide, containing a cell-penetrating peptide and an NF-κB inhibitory peptide derived from the p50 nuclear localization sequence (abbreviated SynB1-ELP-p50i), blocked NF-κB activation and prevented TNF-α (tumor necrosis factor alpha)-induced endothelin production in vitro. Fusion of the p50i peptide to the SynB1-ELP carrier slowed its plasma clearance and prevented its placental transfer in pregnant rats, resulting in increased deposition in the maternal kidney, liver, and placenta relative to the free peptide. When administered in a rat model of placental ischemia, SynB1-ELP-p50i partially ameliorated placental ischemia-induced hypertension and reduced placental TNF-α levels with no signs of toxicity. These data support the continued development of ELP-delivered NF-κB inhibitors as maternally sequestered anti-inflammatory agents for preeclampsia therapy.

Protective effect of metformin on a rat model of lipopolysaccharide-induced preeclampsia

Recent in vitro and clinical studies have found that metformin (MET) may play a preventive or therapeutic role in preeclampsia (PE) and may be a candidate drug for the prevention and/or treatment of PE. In this study, we used lipopolysaccharide (LPS) to induce a PE-like rat model and investigated the intervention effect of MET from the perspectives of clinical manifestations, placental morphology, serum marker for placental injury, systemic inflammatory response and oxidative/nitrative stress, and placental nuclear factor-κB (NF-κB) signaling. The results showed that MET improved LPS-induced hypertension, proteinuria, fetal growth restriction (FGR) and stillbirth, alleviated placental injury and decreased maternal serum marker alpha-fetoprotein (MS-AFP) level; MET suppressed LPS-induced TNF-α and IL-6 productions, reduced oxidative/nitrative stress as evidenced by increased superoxide dismutase (SOD) activity, decreased inducible nitric oxide synthase (iNOS) activity, and decreased levels of malondialdehyde (MDA) and nitric oxide (NO); MET inhibited LPS-induced NF-κB activation in placentas. Based on these findings, it can be concluded that MET is beneficial to the PE-like rat model by protecting placentas from injury, suppressing systemic inflammatory response and oxidative/nitrative stress, and inhibiting placental NF-κB signaling pathway. MET is a promising drug for prevention and/or treatment of PE.

MicroRNA‑144‑3p may participate in the pathogenesis of preeclampsia by targeting Cox‑2

Preeclampsia remains a major cause of maternal mortality and morbidity worldwide. It is generally accepted that the development of the placenta, including spiral artery remodelling, normal trophoblast cells function and maternal-fetal inflammation-immune interactions, is critical for the pathogenesis of preeclampsia. Several investigations have demonstrated that microRNAs (miRNAs/miRs) in the placenta may be potential molecular markers for diagnosis of preeclampsia. In the current study, the aim was to investigate the expression of miR-144-3p in the placenta of patients with preeclampsia and normal placentas, and to explore the potential target genes. miRNA microarray analysis was performed using three paired placentas (preeclampsia and normal) in order to find differential expression of miRNAs. Following this, miR-144-3p was selected as a differentially expressed miRNA and validated using in situ hybridization to determine the clinical significance in placentas with preeclampsia. A potential target gene of miR-144-3p, cyclooxygenase-2 (Cox-2), was identified by bioinformatics, luciferase reporter assay and western blotting. The expression of Cox-2 was also examined by immunohistochemical staining of samples of placenta from patients with preeclampsia and normal placenta. Western blot analysis was performed to investigate the effect of miR-144-3p on the expression of Cox-2 in HTR-8/SVneo cells in vitro. miR-144-3p was decreased in placentas from patients with preeclampsia. A luciferase reporter assay demonstrated that Cox-2 was a potential miR-144-3p target gene and the result was verified by western blotting. A negative correlation was observed between miR-144-3p and Cox-2 in preeclamptic placenta by immunohistochemical staining and in situ hybridization. Western blot analysis demonstrated that overexpression of miR-144-3p decreased Cox-2 expression by 38.2% in HTR-8/SVneo cells. Understanding the differential expression of miR-144-3p and its association with Cox-2 may aid the exploration of the pathogenesis of preeclampsia, and contribute to the development of miRNA-based therapies in the future.

Activation of a TLR9 mediated innate immune response in preeclampsia

Preeclampsia is a multisystemic disorder leading to the development of a placental ischemic microenvironment with a resultant increase in oxidative stress. There is evidence that mitochondrial dysfunction and the innate immune system both play a role in the pathophysiology of this disease. Mitochondrial DAMPs such as mtDNA bind specific pattern recognition receptors such as Toll-like receptor 9 (TLR9) on the endosomal surface of immune cells, in particular neutrophils, subsequently activating them and triggering an innate response. We hypothesised that the exaggerated innate immune response seen in preeclampsia is provoked by dysfunctional mitochondria. Here we provide evidence that TLR9 activity is significantly increased at time of disease in women with preeclampsia. Furthermore, we show activation of neutrophil markers, Calprotectin, Myeloperoxidase (MPO), and IL-8 are significantly increased at time of disease compared to uncomplicated pregnancies. This research supports a potential role of TLR9 activation of an innate immune response evident in preeclampsia which may possibly be initially triggered by dysfunctional mitochondria.

The role of α2-adrenergic receptors in hypertensive preeclampsia: A hypothesis

Preeclampsia, a major disorder of human pregnancy, manifests as persistent hypertension and proteinuria presenting after 20 weeks of pregnancy. Multiple systemic symptoms might be associated with preeclampsia including thrombocytopenia, liver impairment, pulmonary edema, and cerebral disturbances. However, vascular dysfunction remains the core pathological driver of preeclampsia. Defective placental implantation followed by dysfunctional placental spiral artery development promotes a hypoxic environment. Massive endothelial dysfunction characterized by reduced vasodilation, augmented vasoconstriction, and increased vascular permeability and inflammation ensues. Interestingly, the same signaling and inflammatory pathways implicated in preeclampsia appear to be shared with other vascular disorders involving alteration of α₂ -AR function. The role of α₂ -ARs in the regulation of microcirculatory function has long been recognized, thus raising the question of whether they are involved in the pathogenesis of vascular dysfunction in preeclampsia. Here, we review possible interplay between signaling and inflammatory pathways common to preeclampsia and α₂ -AR function/regulation. We speculate on the potential contribution of these receptors to the observed phenotype and the potential role for their pharmacological modulators as therapeutic interventions with preeclampsia.

NF-κB-responsive miRNA-31-5p elicits endothelial dysfunction associated with preeclampsia via down-regulation of endothelial nitric-oxide synthase

Inflammatory cytokines, including tumor necrosis factor-α (TNFα), were elevated in patients with cardiovascular diseases and are also considered as crucial factors in the pathogenesis of preeclampsia; however, the underlying pathogenic mechanism has not been clearly elucidated. This study provides novel evidence that TNFα leads to endothelial dysfunction associated with hypertension and vascular remodeling in preeclampsia through down-regulation of endothelial nitric-oxide synthase (eNOS) by NF-κB-dependent biogenesis of microRNA (miR)-31-5p, which targets eNOS mRNA. In this study, we found that miR-31-5p was up-regulated in sera from patients with preeclampsia and in human endothelial cells treated with TNFα. TNFα-mediated induction of miR-31-5p was blocked by an NF-κB inhibitor and NF-κB p65 knockdown but not by mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase inhibitors, indicating that NF-κB is essential for biogenesis of miR-31-5p. The treatment of human endothelial cells with TNFα or miR-31-5p mimics decreased endothelial nitric-oxide synthase (eNOS) mRNA stability without affecting eNOS promoter activity, resulting in inhibition of eNOS expression and NO/cGMP production through blocking of the functional activity of the eNOS mRNA 3'-UTR. Moreover, TNFα and miR-31-5p mimic evoked endothelial dysfunction associated with defects in angiogenesis, trophoblastic invasion, and vasorelaxation in an ex vivo cultured model of human placental arterial vessels, which are typical features of preeclampsia. These results suggest that NF-κB-responsive miR-31-5p elicits endothelial dysfunction, hypertension, and vascular remodeling via post-transcriptional down-regulation of eNOS and is a molecular risk factor in the pathogenesis and development of preeclampsia.

Increased expression of toll-like receptors 2 and 9 is associated with reduced DNA methylation in spontaneous preterm labor

The cause of spontaneous preterm labor (sPTL) is not known, but it could be due to epigenetic alterations that increase the sensitivity of decidual tissue to inflammatory stimuli. We collected decidual tissue from women at term not in labor (TNL), women at term in labor (TL), and women with sPTL. Illumina Infinium HumanMethylation450 BeadChip analysis revealed significantly reduced DNA methylation for TLR-2 and TLR-9 in sPTL as compared to TL. Immunohistochemical staining documented significantly increased expression of TLR-2 and TLR-9 in decidual tissue of women with sPTL as compared to TL or TNL. TLR expression was not present in decidual cells, but localized to tissue leukocytes as revealed by staining for CD14, a macrophage antigen, and neutrophil elastase. Microarray analysis of inflammatory genes to assess innate immune response demonstrated marked increases in expression of inflammatory cytokines and chemokines in women with TL as compared to TNL. However, when sPTL was compared to TL, there was a further increase in inflammatory cytokines, and a remarkable increase in neutrophil chemokines. These results suggest that epigenetic mechanisms could play a role in increasing leukocyte infiltration, and increasing the sensitivity of decidual tissue to inflammatory stimuli that could precipitate labor prematurely.

Effects of selenium-lead interaction on the gene expression of inflammatory factors and selenoproteins in chicken neutrophils

Lead (Pb) is one of the most highly toxic metal pollutant that can cause damage to the immune system. It is known that selenium (Se) can antagonize heavy metals. To explore the toxic effects of Pb poisoning on bird immune cells, as well as the alleviating effects of Se on Pb, Se supplement and/or Pb poisoning chicken models were established. One hundred and eighty Hyline 7-day-old male chickens received either Se (1mg Se per kg of diet), Pb (350mg Pb per liter water) or Se+Pb in their diet and water for 90 days. Then, whole blood was collected from the four groups of chickens, and serum and neutrophils were isolated. The levels of Se and Pb in chicken serum, mRNA levels of 24 selenoproteins (GPX1, GPX2, GPX3, GPX4, Dio1, Dio2, Dio3, Txnrd1, Txnrd2, Txnrd3, SELS, SPS2, SELK, SELW1, SEP15, SEPX1, SELT, SELI, SELO, SELM, SEPN1, SEPP1, SELU, SELH) and inflammatory factors (TNF-α, COX-2, iNOS, NF-κB), and iNOS protein level in chicken neutrophils were determined, and protein-protein interaction prediction and principal component analysis were performed. The data showed that Pb exposure increased Pb content in serum, activated the NF-κB pathway, and increased the expression of selenoproteins in chicken neutrophils. Se supplements could reduce Pb concentration in serum, had a mitigative effect on the activation of the NF-κB pathway and further enhanced the upward trend of selenoprotein expression induced by Pb exposure. These results suggest that Se supplement could eliminate Pb in serum and alleviate the activation of the NF-κB pathway under Pb exposure by increasing the expression of selenoproteins.

High levels of HtrA4 observed in preeclamptic circulation drastically alter endothelial gene expression and induce inflammation in human umbilical vein endothelial cells

Introduction

Preeclampsia (PE) is a life-threatening pregnancy disorder characterized by wide-spread endothelial dysfunction. Placental factors circulating in the maternal blood are believed to cause endothelial dysfunction. Our previous study identified HtrA4 as a placenta-specific serine protease that is released into the maternal circulation and significantly increased in early-onset PE. In this study, we examined the impact of HtrA4 on expression of endothelial genes related to vessel biology, using human umbilical vein endothelial cells (HUVECs) as a model.

Methods

HUVECs were treated with 0 or 3 μg/ml HtrA4 (highest concentration seen in PE circulation) for 24 h and analysed by an endothelial cell biology PCR array containing 84 genes. HtrA4-induced changes were then validated by real-time RT-PCR and ELISA for time and dose dependency.

Results

High levels of HtrA4 significantly altered the expression of a range of genes related to inflammation, vaso-activity, angiogenesis, cell adhesion, platelet activation and coagulation. In particular, pro-inflammatory genes IL6, PTGS2 (COX2) and IL1B were significantly increased by HtrA4. IL6 protein in HUVEC media was also drastically increased. THBD, an anticoagulant factor reported to be increased in PE, was significantly up-regulated by HtrA4. In contrast, THBS1, which is involved in many regulatory processes of endothelial cell biology, was severely down-regulated by HtrA4.

Discussion

HtrA4 significantly increased the inflammatory responses of HUVECs, and altered their expression of a number of genes important for vessel biology. These data suggest that placenta-derived HtrA4 that is increased in PE circulation is a potential causal factor of endothelial dysfunction.

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HtrA4 altered expression of endothelial genes involved in vessel biology.

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HtrA4 significantly induced inflammation in endothelial cells.

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Placental-derived HtrA4 is a potential causal factor of endothelial dysfunction.

Astaxanthin blocks preeclampsia progression by suppressing oxidative stress and inflammation

To investigate the antioxidative effect of astaxanthin on Nω-nitro-L-arginine methyl ester (L-NAME)-induced preeclamptic rats. Cell survival, the level of reactive oxygen species (ROS) and the changes in mitochondrial membrane potential (MMP) were examined in astaxanthin and H2O2-treated human umbilical vein endothelial cells (HUVECs). The preeclamptic Sprague-Dawley (SD) rat model was established by injection of L‑NAME and treatment with astaxanthin. The activities of malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) in serum were analyzed. Pathological changes were examined by hematoxylin and eosin (H&E) staining. The expression of nuclear factor (NF)‑κB, Rho‑associated protein kinase II (ROCK II), heme oxygenase‑1 (HO‑1) and caspase 3 in preeclamptic placentas were examined by immunohistochemistry. Astaxanthin significantly reduced H2O2‑induced HUVEC cell death, decreased ROS and increased MMP. Astaxanthin significantly reduced blood pressure and the content of MDA, but significantly increased the activity of SOD in preeclamptic rats. The urinary protein and the level of NO and NOS were also decreased. H&E staining revealed that the thickness of the basilar membrane was increased, while the content of trophoblast cells and spiral arteries were reduced following astaxanthin treatment. Immunohistochemistry results showed that the expression of NF‑κB, ROCK II and caspase 3 in preeclamptic placentas was significantly decreased after astaxanthin treatment, while HO‑1 expression was increased. In conclusion, astaxanthin inhibited H2O2‑induced oxidative stress in HUVECs. Astaxanthin treatment significantly improved L‑NAME‑induced preeclamptic symptoms and reduced the oxidative stress and inflammatory damages in preeclamptic placentas. Astaxanthin treatment may effectively prevent and treat preeclampsia.

Amnion as a surrogate tissue reporter of the effects of maternal preeclampsia on the fetus

BACKGROUND

Preeclampsia, traditionally characterized by high blood pressure and proteinuria, is a common pregnancy complication, which affects 2-8 % of all pregnancies. Although children born to women with preeclampsia have a higher risk of hypertension in later life, the mechanism of this increased risk is unknown. DNA methylation is an epigenetic modification that has been studied as a mediator of cellular memory of adverse exposures in utero. Since each cell type in the body has a unique DNA profile, cell subtype composition is a major confounding factor in studies of tissues with heterogeneous cell types. The best way to avoid this confounding effect is by using purified cell types. However, using purified cell types in large cohort translational studies is difficult. The amnion, the inner layer of the fetal membranes of the placenta, is derived from the epiblast and consists of two cell types, which are easy to isolate from the delivered placenta. In this study, we demonstrate the value of using amnion samples for DNA methylation studies, revealing distinctive patterns between fetuses exposed to proteinuria or hypertension and fetuses from normal pregnancies.

RESULTS

We performed a genome-wide DNA methylation analysis, HpaII tiny fragment Enrichment by Ligation-mediated PCR (HELP)-tagging, on 62 amnion samples from the placentas of uncomplicated, normal pregnancies and from those with complications of preeclampsia or hypertension. Using a regression model approach, we found 123, 85, and 99 loci with high-confidence hypertension-associated, proteinuria-associated, and hypertension- and proteinuria-associated DNA methylation changes, respectively. A gene ontology analysis showed DNA methylation changes to be selecting genes with different biological processes in exposure status. We also found that these differentially methylated regions overlap loci previously reported as differentially methylated regions in preeclampsia.

CONCLUSIONS

Our findings support prior observations that preeclampsia is associated with changes of DNA methylation near genes that have previously been found to be dysregulated in preeclampsia. We propose that amniotic membranes represent a valuable surrogate fetal tissue on which to perform epigenome-wide association studies of adverse intrauterine conditions.

Exposure to stimulatory CpG oligonucleotides during gestation induces maternal hypertension and excess vasoconstriction in pregnant rats

Bacterial infections increase risk for pregnancy complications, such as preeclampsia and preterm birth. Unmethylated CpG DNA sequences are present in bacterial DNA and have immunostimulatory effects. Maternal exposure to CpG DNA induces fetal demise and craniofacial malformations; however, the effects of CpG DNA on maternal cardiovascular health have not been examined. We tested the hypothesis that exposure to synthetic CpG oligonucleotides (ODNs) during gestation would increase blood pressure and cause vascular dysfunction in pregnant rats. Pregnant and nonpregnant female rats were treated with CpG ODN (ODN 2395) or saline (Veh) starting on gestational day 14or corresponding day for the nonpregnant groups. Exposure to CpG ODN increased systolic blood pressure in pregnant (Veh: 121 ± 2 mmHg vs. ODN 2395: 134 ± 2 mmHg,P< 0.05) but not in nonpregnant rats (Veh: 111 ± 2 mmHg vs. ODN 2395: 108 ± 5 mmHg,P> 0.05). Mesenteric resistance arteries from pregnant CpG ODN-treated rats had increased contractile responses to U46619 [thromboxane A2(TxA2) mimetic] compared with arteries from vehicle-treated rats [Emax(%KCl), Veh: 87 ± 4 vs. ODN 2395: 104 ± 4,P< 0.05]. Nitric oxide synthase (NOS) inhibition increased contractile responses to U46619, and CpG ODN treatment abolished this effect in arteries from pregnant ODN 2395-treated rats. CpG ODN potentiated the involvement of cyclooxygenase (COX) to U46619-induced contractions. In conclusion, exposure to CpG ODN during gestation induces maternal hypertension, augments resistance artery contraction, increases the involvement of COX-dependent mechanisms and reduces the contribution of NOS-dependent mechanisms to TxA2-induced contractions in mesenteric resistance arteries.

Is neutrophil/lymphocyte ratio a useful marker to predict the severity of pre-eclampsia?

OBJECTIVE

To evaluate the relationship of neutrophil/lymphocyte ratio (NLR) with proteinuria and blood pressure level in patients with pre-eclampsia and to investigate whether or not NLR has a role in predicting the severity of pre-eclampsia.

STUDY DESIGN

The study comprised 30 healthy pregnant females (Group 1), 37 females with mild pre-eclampsia (Group 2) and 40 with severe pre-eclampsia (Group 3). All the study participants were statistically compared in respect of demographic data, proteinuria levels, and blood pressure levels.

RESULT

Age, body mass index, and gestational weeks were similar in all the groups. Maternal NLR was determined to be significantly high in the pre-eclamptic patients (Groups 2 and 3) compared to the healthy pregnant patients (Group 1) (p=0.017). NLR was significantly higher in the severe pre-eclampsia group than in the mild pre-eclampsia group (p=0.032). A significant positive correlation was determined in correlation analysis between NLR and proteinuria (p=0.013, r=0.319). There was also a significant and positive correlation between NLR and systolic/diastolic arterial pressure (p=0.007, r=0.285; p=0.044, r=0.213, respectively).

CONCLUSION

In conclusion, while NLR was determined as significantly high in patients with pre-eclampsia, to be able to use this in the classification of the severity of pre-eclampsia, there is a need for further studies on a more extensive population.

Correlation of long-chain fatty acid oxidation with oxidative stress and inflammation in pre-eclampsia-like mouse models

INTRODUCTION

Pre-eclampsia has been further recognized as a syndrome during pregnancy. Recent studies have found that long-chain fatty acid oxidation (FAO) disorders may be associated with some of pre-eclampsia. However, the mechanism remains unclear. In this study, we investigated the role of FAO and its relationship with oxidative stress and inflammatory signaling pathways in the pathogenesis of pre-eclampsia.

METHODS

PE-like groups included ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nω-nitro-l-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS), and antiphospholipid syndrome (APS) mouse model with β2GPI injection. The control group included wild-type mice with normal saline injection. Serum FFA was compared and placental and hepatic LCHAD, p47phox and NF-κB mRNA and protein were detected using real-time quantitative PCR and western blot.

RESULTS

FFA levels were significantly increased and were positively correlated with P47phox and NF-κB mRNA and protein expression in liver of all groups (p < 0.05), except LPS group (p < 0.05) as compared to control. LCHAD mRNA and protein expression in the liver and placenta was significantly increased in ApoC3+NS, ApoC3+L-NA, and β2GPI group, whereas decreased in L-NA group (p < 0.05) as compared to the control group. P47phox mRNA, NF-κB mRNA, and protein expression in the liver of all groups, except in LPS and in the placenta of β2GPI and L-NA groups, significantly increased (p < 0.05).

DISCUSSION

FAO disorders were involved in the pathogenesis of pre-eclampsia through oxidative stress and inflammatory endothelial cell injury.

Matrix Metalloproteinase 1 Causes Vasoconstriction and Enhances Vessel Reactivity to Angiotensin II via Protease-Activated Receptor 1

Matrix metalloproteinase 1 (MMP-1) is an activator of protease-activated receptor 1 (PAR-1), which is known to mediate the release of endothelin 1 (ET-1) in endothelial cells and activate the RhoA kinase (ROCK) pathway. Recently, we reported increased serum and vascular MMP-1 in women with preeclampsia and hypothesized that the action of MMP-1 on PAR-1 might have vasoconstrictive effects. Resistance-sized omental arteries obtained from normal pregnant women were mounted on a myograph system and perfused with MMP-1 in a dose range of 0.025 to 25 ng/mL or with angiotensin II (Ang II) in a dose range of 0.001 to 10 µmol/L in the presence of intraluminal MMP-1 (2.5 ng/mL) perfusion. Angiotensin II dose response was also performed with omental arteries from women with preeclampsia. Matrix metalloproteinase 1 caused dose-dependent vasoconstriction in endothelium-intact, but not in endothelium-denuded, vessels from normal pregnant women, which was blocked by inhibitors of PAR-1 and ET-1 type A receptor blocker. Intraluminal perfusion with a constant amount of MMP-1 enhanced vessel reactivity to Ang II, which was blocked by inhibitors of PAR-1, ROCK, and ET-1. Enhanced vascular reactivity to Ang II was observed in endothelium-intact, but not in endothelium-denuded, arteries of women with preeclampsia. Inhibitors of PAR-1, ROCK, and ET-1 blocked enhanced vascular reactivity to Ang II in endothelium-intact preeclamptic arteries. These data demonstrate that MMP-1 has potent vasoconstrictor effects and the ability to enhance vascular reactivity to vasoconstrictor hormones, which are mediated by an endothelial PAR-1, ROCK, and ET-1 pathway. Increased circulating levels of MMP-1 and its increased expression in systemic vessels of women with preeclampsia may contribute to the development of maternal hypertension.

Neutrophil functions in morbidly obese subjects

The present study aimed to determine different peripheral blood neutrophil functions in 18 morbidly obese subjects with body mass index (BMI) ranging between 35 and 69 kg/m(2) in parallel with age- and gender-matched lean controls. Peripheral blood neutrophil functions of obese subjects and matched lean controls were determined. Neutrophils of obese subjects showed significant elevation of the release of basal superoxides (P < 0.0001), formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated superoxides (P < 0.0001) and opsonized zymosan (OZ)-stimulated superoxides (P < 0.045) compared with lean controls. Interestingly, there were no differences in phorbol myristate acetate (PMA)-stimulated superoxide production by neutrophils of the obese subjects and controls. There was also a significant elevation of chemotactic (P < 0.0003) and random (P < 0.0001) migration of neutrophils from obese subjects compared with lean controls. Phagocytosis, CD11b surface expression and adherence of neutrophils from obese subjects were not significantly different from those of the lean controls. The elevated superoxide production and chemotactic activity, together with the normal phagocytosis and adherence, suggest that neutrophils from obese subjects are primed and have the capability to combat infections. However, neutrophils in the priming state may participate in the pathogenesis of obesity-related diseases.

Neutrophil release of myeloperoxidase in systemic vasculature of obese women may put them at risk for preeclampsia

Obesity is a risk factor for preeclampsia, but the reason for this risk is unknown. Neutrophils infiltrate into systemic blood vessels of both obese and preeclamptic women. Neutrophils are a major source of myeloperoxidase (MPO), which is associated with hypertension. We tested the hypothesis that systemic vasculature of both obese and preeclamptic women will have a significant presence of MPO as a result of neutrophil infiltration. We found that immunohistochemical staining of MPO was significantly greater in subcutaneous fat blood vessels of obese women than overweight women, which was significantly greater than normal weight women. Expression of MPO was significantly greater in maternal blood vessels of preeclamptic women than normal pregnant or normal nonpregnant women. In general, when vessels of overweight or normal pregnant women were stained it was primarily for leukocytes in the lumen and not infiltrated into the vessel. In contrast, in obese and preeclamptic women staining was present for leukocytes in the lumen, flattened, and adhered to the endothelium and infiltrated into the vessel wall. There was also extensive diffuse staining for MPO in vessels of obese and preeclamptic women. In conclusion, both obese and preeclamptic women have increased presence of MPO in systemic vasculature as a result of neutrophil infiltration. We speculate that obese women may be at risk of preeclampsia because their vasculature is already prone to hypertension.