Leukocyte activation and circulating leukocyte-derived microparticles in preeclampsia

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.

Advances in extracellular vesicles as mediators of cell-to-cell communication in pregnancy

Cell-to-cell communication mediated by Extracellular Vesicles (EVs) is a novel and emerging area of research, especially during pregnancy, in which placenta derived EVs can facilitate the feto-maternal communication. EVs comprise a heterogeneous group of vesicle sub-populations with diverse physical and biochemical characteristics and originate by specific biogenesis mechanisms. EVs transfer molecular cargo (including proteins, nucleic acids, and lipids) between cells and are critical mediators of cell communication. There is growing interest among researchers to explore into the molecular cargo of EVs and their functions in a physiological and pathological context. For example, inflammatory mediators such as cytokines are shown to be released in EVs and EVs derived from immune cells play key roles in mediating the immune response as well as immunoregulatory pathways. Pregnancy complications such as gestational diabetes mellitus, preeclampsia, intrauterine growth restriction and preterm birth are associated with altered levels of circulating EVs, with differential EV cargo and bioactivity in target cells. This implicates the intriguing roles of EVs in reprogramming the maternal physiology during pregnancy. Moreover, the capacity of EVs to carry bioactive molecules makes them a promising tool for biomarker development and targeted therapies in pregnancy complications. This review summarizes the physiological and pathological roles played by EVs in pregnancy and pregnancy-related disorders and describes the potential of EVs to be translated into clinical applications in the diagnosis and treatment of pregnancy complications.

Progesterone modulates TNF receptors expression by Jurkat cells cultured with plasma from pregnant women with preeclampsia

Pregnant women with preeclampsia (PE) present a shift in the immune response to an inflammatory profile. This deviation could be due to the interaction of tumor necrosis factor (TNF) with TNFR1 and TNFR2 receptors, besides the failure in modulation of inflammation regulatory mechanisms. This study evaluated the effects of progesterone on the expression of TNFR1 and TNFR2 by Jurkat cells after stimulation with plasma from PE and normotensive (NT) pregnant women. Jurkat cells were cultured with or without progesterone in a medium containing 20% (v/v) plasma from PE or NT women. The expression of TNF receptors was evaluated by flow cytometry. The concentration of soluble forms of TNF receptors and cytokines was determined in culture supernatant and plasma by ELISA. The plasma of PE women showed significantly higher concentrations of sTNFR1 and TNF and lower concentrations of sTNFR2 compared to the NT group. TNFR1 receptor expression was increased in Jurkat cells, while TNFR2 was decreased after culture with PE plasma when compared with Jurkat cells cultured with progesterone and plasma from NT women. The concentration of sTNFR1, TNF, and IL-10 in the culture supernatant of Jurkat cells was increased after culture with PE plasma, while the sTNFR2 receptor was decreased when compared to the NT group. Results demonstrate that in preeclamptic women a systemic inflammation occurs with an increase of inflammatory molecules, and progesterone may have a modulating effect on the expression of TNF receptors, shifting Jurkat cells towards an anti-inflammatory profile with greater expression of TNFR2.

Post-exercise endothelial function is not associated with extracellular vesicle release in healthy young males

Acute exercise can result in temporary decrease in endothelial functions, which may represent a transient period of risk. Numerous mechanisms underpinning these responses included release of extracellular vesicles (EVs) derived from apoptotic or activated endothelial cells and platelets. This study aims to compare the time course of endothelial responses to moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) and the associations with EV release. Eighteen young healthy males (age: 22.6 ± 3.7 years, BMI: 25.6 ± 2.5 m²/kg, and VO_2peak: 38.6 ± 6.5 mL/kg/min) completed two randomly assigned exercises: HIIE (10 × 1 min-@-90% heart rate reserve (HRR) and 1 min passive recovery) and MICE (30 min-@-70% HRR) on a cycle ergometer. Flow-mediated dilation (FMD) was used to assess endothelial function and blood samples were collected to evaluate endothelial cell-derived EV (CD62E⁺) and platelet-derived EV (CD41a⁺), 10, 60, and 120 min before and after exercise. There were similar increases but different time courses (P = 0.017) in FMD (increased 10 min post-HIIE, P < 0.0001 and 60 min post-MICE, P = 0.038). CD62E⁺ remained unchanged (P = 0.530), whereas overall CD41a⁺ release was reduced 60 min post-exercise (P = 0.040). FMD was not associated with EV absolute release or change (P > 0.05). Acute exercise resulted in similar improvements, but different time course in FMD following either exercise. Whilst EVs were not associated with FMD, the reduction in platelet-derived EVs may represent a protective mechanism following acute exercise.

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.

Healthy and preeclamptic pregnancies show differences in Guanylate-Binding Protein-1 plasma levels

The large interferon-inducible anti-angiogenic pro-inflammatory GTPase Guanylate Binding Protein-1 (GBP-1) is produced and secreted by activated endothelial cells and is highly induced by inflammatory cytokines and inhibited by angiogenic growth factors. During pregnancy a generalized mild inflammatory response is observed. During preeclampsia this generalized inflammatory response is even further activated and activation of the endothelium occurs. We hypothesized that GBP-1 is increased in healthy pregnancy and will be even further increased during preeclampsia. In the first experiment, plasma and placentas were collected from healthy and preeclamptic pregnancies. Plasma was also collected from non-pregnant women. For the second experiment longitudinal blood samples from women with a healthy or preeclamptic pregnancy were collected from the end of the first trimester until birth and one sample postpartum. The plasma GBP-1 levels were measured by ELISA and GBP-1 mRNA and protein levels in the placenta were tested by qPCR and immunohistochemistry. During pregnancy higher plasma concentrations of GBP-1 compared with non-pregnant women were observed. Surprisingly, during preeclampsia, plasma GBP-1 levels were lower than in control pregnancies and similar to the level of non-pregnant controls. Placental GBP-1 mRNA levels were not different between healthy and preeclamptic pregnancies and GBP-1 protein was virtually undetectable in the trophoblast by immunohistochemistry in placental tissue. Evaluation of longitudinal samples showed that plasma GBP-1 concentrations increased towards the end of pregnancy in healthy pregnancies, but not in preeclampsia. In line with our hypothesis, we found higher GBP-1 plasma levels during healthy pregnancy. However, plasma GBP-1 did not further increase during preeclampsia, but was stable. Further studies are needed to evaluate why GBP-1 does not increase during preeclampsia.

Overview of extracellular vesicles in the pathogenesis of preeclampsia†

Preeclampsia (PE) is a leading cause of maternal and fetal-neonatal deaths, and its pathogenesis has been linked to the involvement of extracellular vesicles (EVs). EVs are a heterogeneous group of cell-originated membranous vesicles including exosomes, microvesicles, and apoptotic bodies. EVs transport various bioactive cargos such as lipids, proteins, or nucleic acids, and thus mediate cellular communication and contribute to the proper functioning of cells, organs and processes, including normal pregnancy. Numerous studies have reported that EVs are associated with abnormal levels of soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and placental growth factor (PlGF) in PE. EVs isolated from preeclamptic women have been implicated in trophoblast dysfunction and have been reported to activate endothelium, monocytes, and platelets, and to be involved in defective placentation, imbalanced angiogenesis, and intravascular inflammation. When injected into pregnant rodents, these EVs induced hypertension, proteinuria, and adverse fetal outcomes. Deciphering the contribution of EVs to PE will advance our current understanding of this disorder and may lead to more clinical strategies for the management of PE. Of note, the composition of EV cargos may be characteristic of the status and stages of gestation, providing researchers the possibility of one day using EVs as novel, noninvasive, biomarkers for early screening of PE. Herein, we reviewed the latest research into EVs with emphasis on their role in the pathogenesis of PE and their applications as biomarkers in the early screening of this pregnancy-specific disorder.

Progesterone and vitamin D downregulate the activation of the NLRP1/NLRP3 inflammasomes and TLR4-MyD88-NF-κB pathway in monocytes from pregnant women with preeclampsia

This study evaluated the in vitro modulatory effect of progesterone (PG) and vitamin D (VD) on NLRP1/NLRP3 inflammasomes and TLR4/NF-κB pathway in monocytes from pregnant women with preeclampsia (PE). Monocytes from 20 preeclamptic and 20 normotensive (NT) pregnant women, and THP-1 cells were cultured with/without hyaluronan (HA), PG, or VD to determine gene and protein expression of TLR4 receptor, phosphorylated NF-κB, IκBα, TLR4, MYD88, NF-κB, NLRP1, NLRP3, caspase-1, IL-1β, IL-18, TNF-α, and IL-10. Higher endogenous activation of inflammatory genes and higher protein expression of TLR4 and NF-κB was detected in monocytes of PE group and decreased after PG or VD treatment. Monocyte from PE stimulated with HA increased while treatment with PG or VD decreased the expression of genes and proteins related to the inflammasomes. THP-1 cells showed a similar immune response profile as monocytes from PE. These results demonstrate that PG and VD play an immunomodulatory role in monocyte activation.

Extracellular Vesicles and Preeclampsia: Current Knowledge and Future Research Directions

Preeclampsia (PE) is associated with long-term morbidity in mothers and lifelong morbidities for their children, ranging from cerebral palsy and cognitive delay in preterm infants, to hypertension, diabetes and obesity in adolescents and young adults. There are several processes that are critical for development of materno-fetal exchange, including establishing adequate perfusion of the placenta by maternal blood, and the formation of the placental villous vascular tree. Recent studies provide persuasive evidence that placenta-derived extracellular vesicles (EVs) represent a significant intercellular communication pathway, and that they may play an important role in placental and endothelial cell (both fetal and maternal) function. These functions are known to be altered in PE. EVs can carry and transport a wide range of bioactive molescules that have potential to be used as biomarkers and therapeutic delivery tools for PE. EV content is often parent cell specific, thus providing an insight or "thumbprint" of the intracellular environment of the originating cell (e.g., human placenta). EV have been identified in plasma under both normal and pathological conditions, including PE. The concentration of EVs and their content in plasma has been reported to increase in association with disease severity and/or progression. Placenta-derived EVs have been identified in maternal plasma during normal pregnancy and PE pregnancies. They contain placenta-specific proteins and miRNAs and, as such, may be differentiated from maternally-derived EVs. The aim of this review, thus, is to describe the potential roles of EVs in preecmpatic pregnancies, focussing on EVs secreted from placental cells. The biogenesis, specificity of placental EVs, and methods used to characterise EVs in the context of PE pregnancies will be also discussed.

Glycosylated Siglec-6 expression in syncytiotrophoblast-derived extracellular vesicles from preeclampsia placentas

INTRODUCTION

Preeclampsia (PE) is associated with an exaggerated maternal systemic inflammatory response. Throughout gestation, the placenta releases extracellular vesicles through the syncytiotrophoblast layer (STB) into the maternal circulation and this is increased in PE. Expression of Siglec-6, a transmembrane receptor of molecular weight 50 KDa, is upregulated in PE placental tissue.

METHODS

Here we investigated respective abundance of Siglec-6 in PE -and normal pregnancy- (NP) derived placental lysates (PL) and syncytiotrophoblast-derived extracellular vesicles (STBEV). STBEV from PE and NP placentas were isolated through dual-lobe placental perfusion and serial ultracentrifugation. Siglec-6 was characterized by immunohistochemistry, immunoblotting, mass spectrometry (MS), and deglycosylation.

RESULTS

Immunoblotting revealed the expected Siglec-6 (50 KDa) band present in both PE and NP PL, however an additional heavier band was observed at 70 KDa only in PE PL, but not in NP. When interrogating STBEV we saw an absence of the expected 50 KDa band but the 70 KDa was present predominantly only in the PE STBEV. Deglycosylation of PL and STBEV from PE showed that the 70 KDa and the 50 KDa bands were reduced to 48 KDa, suggesting glycosylation. Both 48 KDa and 70 KDa bands were subjected to MS, confirming Siglec-6 expression in both.

DISCUSSION

Our data shows that the inability to detect Siglec-6 in circulation might be due to the placenta secreting STBEV carrying a modified glycosylated form of Siglec-6 with a 70 KDa molecular weight, significantly and uniquely upregulated in PE STBEV.

Laboratory options for risk assessment of pregnancy pathologies

The most effective method of screening for chromosomal abnormalities and evaluating the risk of pregnancy pathologies in the first trimester is combined screening. The algorithm of screening is based on the combination of maternal age, measuring of the nuchal translucency and the fetal heart rate and analysis of the placental products of free ß-hCG and PAPP-A. For the screening of preeclampsia, placental growth factor (PlGF) is added. To distinguish between preeclampsia and other pathologies caused by placental dysfunction it is recommended to also extend the screening with selected immunological markers. We concluded that elevated biochemical and immunological markers can help to predict the threat of preeclampsia in the third trimester. Some markers can probably predict the development of particularly severe pathological conditions.

Detection of extracellular vesicles in plasma and urine of prostate cancer patients by flow cytometry and surface plasmon resonance imaging

Large (> 1 μm) tumor-derived extracellular vesicles (tdEVs) enriched from the cell fraction of centrifuged whole blood are prognostic in metastatic castration-resistant prostate cancer (mCRPC) patients. However, the highest concentration of tdEVs is expected in the cell-free plasma fraction. In this pilot study, we determine whether mCRPC patients can be discriminated from healthy controls based on detection of tdEVs (< 1μm, EpCAM+) and/or other EVs, in cell-free plasma and/or urine. The presence of marker+ EVs in plasma and urine samples from mCRPC patients (n = 5) and healthy controls (n = 5) was determined by flow cytometry (FCM) and surface plasmon resonance imaging (SPRi) using an antibody panel and lactadherin. For FCM, the concentrations of marker positive (+) particles and EVs (refractive index <1.42) were determined. Only the lactadherin+ particle and EV concentration in plasma measured by FCM differed significantly between patients and controls (p = 0.017). All other markers did not result in signals exceeding the background on both FCM and SPRi, or did not differ significantly between patients and controls. In conclusion, no difference was found between patients and controls based on the detection of tdEVs. For FCM, the measured sample volumes are too small to detect tdEVs. For SPRi, the concentration of tdEVs is probably too low to be detected. Thus, to detect tdEVs in cell-free plasma and/or urine, EV enrichment and/or concentration is required. Furthermore, we recommend testing other markers and/or a combination of markers to discriminate mCRPC patients from healthy controls.

Inflammation-The role of ATP in pre-eclampsia

Sterile inflammation may be initiated by molecules in the host organism that signal "damage" or "danger" also known as danger-associated molecular pattern (DAMPs). In pre-eclampsia (PE), a variety of DAMPs may be involved in the etiology or exacerbation of the disorder. Adenosine 5'-triphosphate (ATP) is a key intracellular energy molecule as well as a ligand for purinergic receptors. In humans, under physiological conditions, extracellular ATP (eATP) levels are distinctly low, but can rise to several hundred fold when cells become injured, stressed, or even necrotic. This often initiates a sterile inflammatory response with eATP acting as a DAMP. Extracellular ATP and its derivative nucleotides synthetized by endonucleotidases exhibit many of their effects through purinergic receptors, via inflammatory cascades and the production of proinflammatory molecules. This is clearly seen in the P2X₇ gated receptor, which is linked to release of cytokines of the interleukin-1 family. Considering its fundamental role in innate immunity, an imbalance of P2X₇ receptor activation may lead to deleterious effects in the coordination of placental vessel tone via the synthesis of various proinflammatory cytokines. This review explores the implication of DAMPs, specifically ATP and uric acid in the inflammation associated with PE.

Contribution of regulatory T cells to immune tolerance and association of microRNA‑210 and Foxp3 in preeclampsia

Increasing evidence suggests that an exaggerated maternal systemic inflammatofrery response may play a central role in the pathogenesis of preeclampsia (PE). Considering the growing evidence on microRNAs (miRNAs) and tissue‑specific regulators of gene expression, we investigated the potential association of miR‑210 and forkhead box p3 (Foxp3) in preeclamptic patients. Serum levels of the cytokines interleukin (IL)‑6, IL‑10, IL‑17, and transforming grown factor‑β1 were detected with ELISA. Reverse‑transcription‑quantitative polymerase chain reaction was performed to detect mRNA expression for maternal placenta retinoic acid‑related orphan receptor C, Foxp3 and miRNA (miR)‑210. Foxp3 protein expression was evaluated by western blot analysis. Serum levels of cytokines IL‑10 were significantly lower in preeclamptic patients than in normal pregnant women. mRNA expression of Foxp3 was significantly lower in placenta of PE. mRNA expression of miR‑210 was significantly increased in PE. Results of western blot analysis indicated that Foxp3 protein expression was lower in PE than in normal pregnant women. Our data suggest that PE manifests as a decreased number of regulatory T cells (Tregs), which regulate maternal tolerance of the fetus. In placenta from women with PE, compared with normal pregnant women, mRNA expression of Foxp3 was significantly decreased, and expression of miR‑210 was significantly increased.

Extracellular Vesicles in Human Reproduction in Health and Disease

Extensive evidence suggests that the release of membrane-enclosed compartments, more commonly known as extracellular vesicles (EVs), is a potent newly identified mechanism of cell-to-cell communication both in normal physiology and in pathological conditions. This review presents evidence about the formation and release of different EVs, their definitive markers and cargo content in reproductive physiological processes, and their capacity to convey information between cells through the transfer of functional protein and genetic information to alter phenotype and function of recipient cells associated with reproductive biology. In the male reproductive tract, epididymosomes and prostasomes participate in regulating sperm motility activation, capacitation, and acrosome reaction. In the female reproductive tract, follicular fluid, oviduct/tube, and uterine cavity EVs are considered as vehicles to carry information during oocyte maturation, fertilization, and embryo-maternal crosstalk. EVs via their cargo might be also involved in the triggering, maintenance, and progression of reproductive- and obstetric-related pathologies such as endometriosis, polycystic ovarian syndrome, preeclampsia, gestational diabetes, and erectile dysfunction. In this review, we provide current knowledge on the present and future use of EVs not only as biomarkers, but also as therapeutic targeting agents, mainly as vectors for drug or compound delivery into target cells and tissues.

Extracellular vesicles and their immunomodulatory functions in pregnancy

Extracellular vesicles (EVs) are membrane-bound vesicles released into the extracellular space by almost all types of cells. EVs can cross the physiological barriers, and a variety of biological fluids are enriched in them. EVs are a heterogeneous population of vesicles, including exosomes, microvesicles, and apoptotic bodies. The different subpopulations of vesicles can be differentiated by size and origin, in which exosomes (~100 nm and from endocytic origin) are the most studied so far. EVs have essential roles in cell-to-cell communication and are critical modulators of immune response under normal and pathological conditions. Pregnancy is a unique situation of immune-modulation in which the maternal immune system protects the fetus from allogenic rejection and maintains the immunosurveillance. The placenta is a vital organ that performs a multitude of functions to support the pregnancy. The EVs derived from the human placenta have crucial roles in regulating the maternal immune response for successful pregnancy outcome. Placenta-derived vesicles perform a myriad of functions like suppression of immune reaction to the developing fetus and establishment and maintenance of a systemic inflammatory response to combat infectious intruders. A fine-tuning of these mechanisms is quintessential for successful completion of pregnancy and healthy outcome for mother and fetus. Dysregulation in the mechanisms mentioned above can lead to several pregnancy disorders. In this review, we summarize the current literature regarding the critical roles played by the EVs in immunomodulation during pregnancy with particular attention to the placenta-derived exosomes.

The impact of circulating preeclampsia-associated extracellular vesicles on the migratory activity and phenotype of THP-1 monocytic cells

Intercellular communication via extracellular vesicles (EVs) and their target cells, especially immune cells, results in functional and phenotype changes that consequently may play a significant role in various physiological states and the pathogenesis of immune-mediated disorders. Monocytes are the most prominent environment-sensing immune cells in circulation, skilled to shape their microenvironments via cytokine secretion and further differentiation. Both the circulating monocyte subset distribution and the blood plasma EV pattern are characteristic for preeclampsia, a pregnancy induced immune-mediated hypertensive disorder. We hypothesized that preeclampsia-associated EVs (PE-EVs) induced functional and phenotypic alterations of monocytes. First, we proved EV binding and uptake by THP-1 cells. Cellular origin and protein cargo of circulating PE-EVs were characterized by flow cytometry and mass spectrometry. An altered phagocytosis-associated molecular pattern was found on 12.5 K fraction of PE-EVs: an elevated CD47 "don't eat me" signal (p < 0.01) and decreased exofacial phosphatidylserine "eat-me" signal (p < 0.001) were found along with decreased uptake of these PE-EVs (p < 0.05). The 12.5 K fraction of PE-EVs induced significantly lower chemotaxis (p < 0.01) and cell motility but accelerated cell adhesion of THP-1 cells (p < 0.05). The 12.5 K fraction of PE-EVs induced altered monocyte functions suggest that circulating EVs may have a role in the pathogenesis of preeclampsia.

Increased circulating microparticles in women with preeclampsia

INTRODUCTION

Preeclampsia (PE) is associated with hypercoagulability, endothelial dysfunction and inflammation, which generate microparticles (MPs). Therefore, MPs may be important for PE.

METHODS

We established a verified MP measurement procedure to detect MPs in nonpregnant women (n = 25), healthy pregnant women (n = 29) and PE women (n = 73) and compared their MP levels.

RESULTS

Microparticles prepared from platelets (PMPs), endothelial cells (EMPs) and leucocytes (LMPs) were confirmed by transmission electron microscopy and were analysed by our established flow cytofluorimetric approach, which showed good specificity for determining the cell origin and level of MPs. The levels of total MPs (tMPs) and PMPs in the healthy pregnant group were significantly higher than those in the nonpregnant group (158.78 vs 93.00 and 45.04 vs 17.41, P = .004 and P = .007, respectively) but were not significantly different from those of the PE group. However, EMPs and LMPs were significantly higher in the PE group than in the healthy pregnant group (14.62 vs 11.48 and 8.94 vs 5.03, P = .015 and P < .001, respectively). Furthermore, the area under the receiver operating characteristic curves (AUC) for EMPs, LMPs and the combined sum of EMPs and LMPs were 0.661, 0.746 and 0.718, respectively (P < . 05); at their optimal cut-off values, the sensitivities were 50.68%, 87.67% and 46.58%, respectively, and the specificities were 80.77%, 58.33% and 95.65%, respectively.

CONCLUSION

Determining the MP level, especially that of EMPs and LMPs, by a specificity-verified method may reflect the endothelial dysfunction and inflammation involved in PE pathogenesis.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Characterization of intravascular cellular activation in relationship to subclinical atherosclerosis in postmenopausal women

Objective

Mechanisms and interactions among intravascular cells contributing to development of subclinical atherosclerosis are poorly understood. In women, both menopausal status and pregnancy history influence progression of atherosclerosis. This study examined activation and interactions among blood elements with subclinical atherosclerosis in menopausal women with known pregnancy histories.

Methods

Carotid intima-media thickness (CIMT), as a marker of subclinical atherosclerosis, was measured using B-mode ultrasound in age- and parity-matched women [40 with and 40 without a history of preeclampsia] 35 years after the index pregnancy. Interactions among intravascular cells (38 parameters) were measured by flow cytometry in venous blood. Data analysis was by principal component which retained 7 independent dimensions accounting for 63% of the variability among 38 parameters.

Results

CIMT was significantly greater in women with a history of preeclampsia (P = 0.004). Platelet aggregation and platelet interactions with granulocytes and monocytes positively associated with CIMT in postmenopausal women independent of their pregnancy history (ρ = 0.258, P< 0.05). However, the association of the number of platelets, platelet activation and monocyte-platelet interactions with CIMT differed significantly depending upon pregnancy history (test for interaction, P<0.001).

Conclusion

Interactions among actived intravascular cells and their association with subclinical atherosclerosis differ in women depending upon their pregnancy histories.

Association between cytokine profile and transcription factors produced by T-cell subsets in early- and late-onset pre-eclampsia

Pre-eclampsia (PE) is an obstetric pathology characterized by abnormal activation of the innate and adaptive immune systems dependent on the imbalance of T helper subsets. The present study aimed to evaluate the gene and protein expression of T helper type 1 (Th1)/Th2/Th17/regulatory T (Treg) cell transcription factors in peripheral blood lymphocytes from pregnant women with PE employing quantitative RT-PCR and flow cytometry techniques, as well as the cytokine profile produced by these CD4+ T-cell subsets in the plasma of pregnant women with PE, classified as early-onset PE (n = 20), late-onset PE (n = 20) and normotensive pregnant women (n = 20). Results showed a higher percentage of CD4+ T cells expressing the RORc transcription factor (Th17) and a lower percentage of cells expressing FoxP3 (Treg) in women with early-onset PE compared with late-onset PE and normotensive groups. A lower gene expression of GATA-3 transcription factor was detected in cells of women with early-onset PE compared with the late-onset PE group. Endogenous plasma levels of interleukin-6 (IL-6), IL-17 and tumour necrosis factor-α were significantly higher in the early-onset PE group than in the late-onset PE and normotensive groups, whereas IL-4 (Th2 profile) and IL-22 (Th17 profile), were not significantly different between the studied groups. The endogenous levels of transforming growth factor-β and IL-10 were significantly lower in the pre-eclamptic than in the normotensive groups of the same gestational age, with a significant difference between early- and late-onset PE. The results show that in women with PE there is an imbalance between inflammatory and anti-inflammatory profiles in CD4+ T-cell subsets, with polarization to Th17 profiles in the early-onset PE, considered as the severe form of PE.

Correlation of Plasma Neutrophil Elastase Activity and Endogenous Protease Inhibitor Levels with the Severity of Pre-eclampsia

INTRODUCTION

Pre-eclampsia (PE) is a common maternal syndrome characterized by severe systemic inflammatory response including neutrophil activation leading to uncontrolled activity of elastase. The excessive activity of elastase would lead to destroyal of the integrity of endothelial cells and could exacerbate the pathophysiological symptoms in PE. Thus, assessment of NE activity and its control mechanisms would be of relevance in the determination of severity of PE.

AIM

To correlate the activity of plasma NE and its endogenous inhibitors α₁-antitrypsin (α₁-AT) and α₂-macroglobulin (α₂-MG) with severity of PE.

MATERIALS AND METHODS

A comparative study was conducted between normotensive pregnant (n=50) and pre-eclamptic (n=50) women. Serum C-Reactive Protein (CRP) was estimated by rapid latex slide and uric acid by uricase method. Plasma elastase was estimated using succinyl tri- L-alanyl-p-nitroanilide as substrate. Plasma α₁-AT, α₂-MG and NE- α₁-AT complex were quantified by ELISA. ANOVA and Pearson's correlation tests were used to analyze the data. The results were expressed as mean±SD and p-value <0.001 was considered statistically highly significant.

RESULTS

The activity of elastase was increased significantly in severe PE (0.62±0.08) in comparison to normal (0.35±0.10) and mild pre-eclamptic subjects (0.37±0.03). The values of α₁-AT were significantly less in mild (83.94±25.08) and severe PE (68.58+26.39) in comparison to normal (110.26±42.39). There was a significant rise in the levels of α₂-MG in severe PE. However, the complex estimation did not evince any significant changes.

CONCLUSION

The results of the present study indicate a significantly elevated elastase activity, α₂-MG levels and decreased α₁-AT in severe PE patients. The correlation analyses of PE severity parameters with NE, α₁-AT and α₂-MG further support the roles of these molecules in the assessment of severity of PE.

Extracellular vesicles in blood, milk and body fluids of the female and male urogenital tract and with special regard to reproduction

Extracellular vesicles (EVs) are released from almost all cells and tissues. They are able to transport substances (e.g. proteins, RNA or DNA) at higher concentrations than in their environment and may adhere in a receptor-controlled manner to specific cells or tissues in order to release their content into the respective target structure. Blood contains high concentrations of EVs mainly derived from platelets, and, at a smaller amount, from erythrocytes. The female and male reproductive tracts produce EVs which may be associated with fertility or infertility and are released into body fluids and mucosas of the urogenital organs. In this review, the currently relevant detection methods are presented and critically compared. During pregnancy, placenta-derived EVs are dynamically detectable in peripheral blood with changing profiles depending upon progress of pregnancy and different pregnancy-associated pathologies, such as preeclampsia. EVs offer novel non-invasive diagnostic tools which may reflect the situation of the placenta and the foetus. EVs in urine have the potential of reflecting urogenital diseases including cancers of the neighbouring organs. Several methods for detection, quantification and phenotyping of EVs have been established, which include electron microscopy, flow cytometry, ELISA-like methods, Western blotting and analyses based on Brownian motion. This review article summarises the current knowledge about EVs in blood and cord blood, in the different compartments of the male and female reproductive tracts, in trophoblast cells from normal and pre-eclamptic pregnancies, in placenta ex vivo perfusate, in the amniotic fluid, and in breast milk, as well as their potential effects on natural killer cells as possible targets.

Preeclampsia and Extracellular Vesicles

Preeclampsia is a hypertensive pregnancy disorder characterized by development of hypertension and proteinuria after 20 weeks of gestation that remains a leading cause of maternal and neonatal morbidity and mortality. While preeclampsia is believed to result from complex interactions between maternal and placental factors, the proximate pathophysiology of this syndrome remains elusive. Cell-to-cell communication is a critical signaling mechanism for feto-placental development in normal pregnancies. One mechanism of cellular communication relates to activated cell-derived sealed membrane vesicles called extracellular vesicles (EVs). The concentrations and contents of EVs in biological fluids depend upon their cells of origin and the stimuli which trigger their production. Research on EVs in preeclampsia has focused on EVs derived from the maternal vasculature (endothelium, vascular smooth muscle) and blood (erythrocytes, leukocytes, and platelets), as well as placental syncytiotrophoblasts. Changes in the concentrations and contents of these EVs may contribute to the pathophysiology of preeclampsia by accentuating the pro-inflammatory and pro-coagulatory states of pregnancy. This review focuses on possible interactions among placental- and maternal-derived EVs and their contents in the initiation and progression of the pathogenesis of preeclampsia. Understanding the contributions of EVs in the pathogenesis of preeclampsia may facilitate their use as diagnostic and prognostic biomarkers.

Endogenous and Uric Acid-Induced Activation of NLRP3 Inflammasome in Pregnant Women with Preeclampsia

Preeclampsia (PE) is a specific syndrome of pregnancy, characterized by hypertension and proteinuria. This pathology is associated with hyperuricemia and elevated serum levels of inflammatory cytokines. Uric acid crystals may activate an intracellular complex called inflammasome, which is important for processing and release of inflammatory cytokines. This study investigated the state of monocyte activation, both endogenous and stimulated with monosodium urate (MSU), by gene expression of NLRP1 and NLRP3 receptors as well as their association with inflammatory cytokines expression. Monocytes were obtained from peripheral blood of 23 preeclamptic pregnant women, 23 normotensive pregnant women (NT) and 23 healthy non-pregnant women (NP). Inflammasome activation was evaluated by the gene expression of NLRP1, NLRP3, caspase-1, IL-1β, IL-18 and TNF-α by RT-qPCR in unstimulated monocytes (endogenous expression), or after cell stimulation with MSU (stimulated expression). The concentration of cytokines was assessed by ELISA. In preeclamptic pregnant women, gene expression of NLRP1, NLRP3, caspase-1, IL-1β and TNF-α by monocytes stimulated or not with MSU was significantly higher than in NT and NP groups. Stimulation of monocytes from preeclamptic and non-pregnant women with MSU induced increased gene expression of NLRP3, caspase-1 and TNF-α in relation to the endogenous expression in these groups, while this was not observed in the NT group. The cytokine determination showed that monocytes from women with PE produced higher endogenous levels of IL-1β, IL-18 and TNF-α compared to the other groups, while the stimulus with MSU led to higher production of these cytokines in preeclamptic group than in the NT group. In conclusion, the results showed increased basal gene expression of NLRP1 and NLRP3 receptors in monocytes from PE group. These cells stimulation with MSU demonstrates that uric acid plays a role in NLRP3 inflammasome activation, suggesting the participation of this inflammatory complex in the pathogenesis of preeclampsia.

Circulating microparticles in umbilical cord blood in normal pregnancy and pregnancy with preeclampsia

INTRODUCTION

Placenta microthrombi being one of the prevalent recurrent histological findings in women with preeclampsia (PE), it is reasonable to think that the study of coagulation alterations in cord blood could be more informative than that observed in maternal blood. The aim of the present study was to measure different subtypes of microparticles (MP) plasma levels in the maternal peripheral blood at labour and in the venous cord blood of pregnant women with PE compared to those in a group of women without PE.

MATERIALS AND METHODS

Thirty-two pregnant women in labour, 16 with and 16 without PE, were enrolled. Blood samples were collected immediately after delivery from cord blood and from maternal peripheral blood. Total, cellular-derived and tissue factor- bearing MP were analyzed using flow-cytometry. Procoagulant activity of MP was assessed using the STA® Procoag PPL assay.

RESULTS

Total MP, platelet activated-derived (P-Selectin+), leukocyte-derived and TF+MP were higher in pregnancies complicated by PE as compared with normotensive women (p<0.05). Platelet-derived MP (CD61+) levels were lower in PE than in healthy women and no difference was found in endothelial-derived MP levels between the two groups. The PPL clotting time was significantly shorter in PE compared with controls. When only venous cord blood was analysed, all MP detected were significantly higher in PE than in healthy normotensive women (p<0.05).

CONCLUSIONS

MP are very likely involved in the hypercoagulable and pro-inflammatory intravascular reactions during PE. Prospective studies in a larger population are needed to define the clinical meaning of MP measurement in the PE setting.

Networks in Coronary Heart Disease Genetics As a Step towards Systems Epidemiology

We present the use of innovative machine learning techniques in the understanding of Coronary Heart Disease (CHD) through intermediate traits, as an example of the use of this class of methods as a first step towards a systems epidemiology approach of complex diseases genetics. Using a sample of 252 middle-aged men, of which 102 had a CHD event in 10 years follow-up, we applied machine learning algorithms for the selection of CHD intermediate phenotypes, established markers, risk factors, and their previously associated genetic polymorphisms, and constructed a map of relationships between the selected variables. Of the 52 variables considered, 42 were retained after selection of the most informative variables for CHD. The constructed map suggests that most selected variables were related to CHD in a context dependent manner while only a small number of variables were related to a specific outcome. We also observed that loss of complexity in the network was linked to a future CHD event. We propose that novel, non-linear, and integrative epidemiological approaches are required to combine all available information, in order to truly translate the new advances in medical sciences to gains in preventive measures and patients care.

Microparticle analysis in disorders of hemostasis and thrombosis

Microparticles (MPs) are submicron vesicles released from the plasma membrane of eukaryotic cells in response to activation or apoptosis. MPs are known to be involved in numerous biologic processes, including inflammation, the immune response, cancer metastasis, and angiogenesis. Their earliest recognized and most widely accepted role, however, is the ability to promote and support the process of blood coagulation. Consequently, there is ongoing interest in studying MPs in disorders of hemostasis and thrombosis. Both phosphatidylserine (PS) exposure and the presence of tissue factor (TF) in the MP membrane may account for their procoagulant properties, and elevated numbers of MPs in plasma have been reported in numerous prothrombotic conditions. To date, however, there are few data on true causality linking MPs to the genesis of thrombosis. A variety of methodologies have been employed to characterize and quantify MPs, although detection is challenging due to their submicron size. Flow cytometry (FCM) remains the most frequently utilized strategy for MP detection; however, it is associated with significant technological limitations. Additionally, preanalytical and analytical variables can influence the detection of MPs by FCM, rendering data interpretation difficult. Lack of methodologic standardization in MP analysis by FCM confounds the issue further, although efforts are currently underway to address this limitation. Moving forward, it will be important to address these technical challenges as a scientific community if we are to better understand the role that MPs play in disorders of hemostasis and thrombosis.

Differential regulation of TNF receptors in maternal leukocytes is associated with severe preterm preeclampsia

We tested the hypothesis that maternal peripheral blood leukocytes contribute to elevated levels of soluble TNF receptors (sTNFR) in preeclampsia (PE) with concomitant intrauterine growth restriction (IUGR). TNFR1 and TNFR2 were evaluated in a cross-sectional study comparing preeclamptic (n = 15) with or without IUGR versus normotensive pregnant women (PREG, n = 30), and non-pregnant controls (Con; n = 20). Plasma levels of sTNFR1 were higher in PE (1675.0 ± 227.1 pg/mL) compared with PREG (1035.0 ± 101.1 pg/mL) and Con (589.3 ± 82.67 pg/mL), with the highest values observed in PE with IUGR (2624.0 ± 421.4 pg/mL; n = 6). Plasma sTNFR2 was higher during pregnancy (PE: 1836.0 ± 198.7 pg/mL; PREG: 1697.0 ± 95.0 pg/mL) compared with Con (598.3 ± 82.7 pg/mL). Urinary levels of sTNFR1 and sTNFR2 were higher in PE and PREG compared with the Con group. Abundance of TNFR1 mRNA in peripheral blood leukocytes was strongly correlated with plasma levels of sTNFR1 in PE. However, TNFR2 mRNA accumulation in leukocytes did not correlate with sTNFR2 plasma levels. The level of sTNFR1 in plasma was correlated with body weight of the newborn (r = -0.56). The data suggest that maternal leukocytes contribute to sTNFR1 levels in plasma in association with decreasing newborn weight and PE with concomitant IUGR.

Different levels of IL-1α, IL-6, TNF-α, NF-κB and PPAR-γ in monocyte cultures exposed by plasma preeclampsia and normotensive pregnancy

OBJECTIVE

To determine different levels of proinflammatory cytokines IL-1α, IL-6, TNF-α, nuclear NF-κB p50 and PPAR-γ in monocyte cultures exposed to normotensive pregnancy plasma compared with those exposed to preeclamptic plasma. Study design The study involved primigravidae with preeclampsia (12) and normotensive pregnancy (12) in which their blood plasma was given to monocyte cultures from isolated PBMC of healthy and non-pregnant women. They were divided into 2 groups, the first group was incubated for 24h and the second one was incubated for 48h (step 1). The levels of IL-1α, IL-6, TNF-α, and nuclear NF-κB p50 as well as PPAR-γ of both groups were subsequently measured and compared (step 2). Data were analyzed to determine the differences and interaction between both treatment groups using one-way ANOVA.

RESULTS

There was a significantly different level (p-value <0.05) of IL-1α in monocyte cultures incubated for 24h compared with those incubated for 48h, as shown in step 1 of the study. Meanwhile, step 2 of the study found significantly different levels of IL-1α, IL-6, TNF-α, and NF-κB p50 in monocyte cultures exposed to preeclamptic plasma compared with those exposed to normotensive pregnancy, in which the latter showed higher levels. Both groups also showed decreased levels of PPARγ, in which monocyte culture exposed to severe preeclamptic plasma (p value <0.05).

CONCLUSION

Preeclamptic plasma significantly increased levels of proinflammatory cytokines IL-1a, IL-6, and TNF-a in monocyte cultures. This condition was consistent with the increasing of NF-κB p50 and decreasing of PPARγ.

Monocytes from pregnant women with pre-eclampsia are polarized to a M1 phenotype

PROBLEM

This study evaluated whether the monocyte inflammatory state in pre-eclampsia (PE) might be associated with polarization to either M1 classically or M2 alternatively activated monocyte subsets.

METHOD OF STUDY

Eighty-five women with (PE) and 52 normotensive (NT) pregnant women matched for gestational age were included. Expression of surface receptors characteristic of M1, such as Toll-like receptor (TLR)2, TLR4, and CD64, or M2, such as CD163 and CD206 monocyte subsets were evaluated in peripheral blood monocytes by flow cytometry. Tumour necrosis factor-alpha (TNF-α), interleukin-(IL)-12p40, IL-12p70, and IL-10 were evaluated in the supernatant of monocyte cultures by ELISA.

RESULTS

Expression of TLR4 and CD64 by monocytes from pre-eclamptic women was significantly higher, while the expression of CD163 and CD206 expression was significantly lower compared with NT pregnant women. Endogenous production of TNF-α, IL-12p40, and IL-12p70 by monocytes was increased, while synthesis of IL-10 was lower in women with PE than in NT pregnant women.

CONCLUSIONS

Monocytes from women with PE are classically activated, producing higher levels of pro-inflammatory cytokines, and express surface receptors characteristic of the M1 subset. These results provide evidence that the systemic inflammatory environment in PE may differentiate and polarize these cells to the M1 phenotype.

High levels of heat shock protein 70 are associated with pro-inflammatory cytokines and may differentiate early- from late-onset preeclampsia

Preeclampsia (PE), a specific syndrome of pregnancy, can be classified into early and late onset, depending on whether clinical manifestations occur before or after 34 weeks' gestation. We determined whether plasma concentrations of Hsp60 and Hsp70 were related to circulating cytokine levels, as well as kidney and liver functions, in early- and late-onset PE. Two hundred and thirty-seven preeclamptic women (95 with early- and 142 with late-onset PE) were evaluated. Plasma levels of Hsp60, Hsp70, and their specific antibodies, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1, IL-10, IL-12, and soluble TNF-α-receptor I (sTNFRI) concentrations, were determined by enzyme-linked immunosorbent assay (ELISA). Concentrations of Hsp70, TNF-α, IL-1β, IL-12, and sTNFRI were significantly elevated in patients with early-onset PE compared with women with late-onset PE; IL-10 levels were significantly lower in the early-onset PE group. Concentrations of urea, uric acid, proteinuria, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) were also significantly higher in early-onset PE. The percentage of infants with intrauterine growth restriction was also significantly higher in women with early-onset PE. There were positive correlations between Hsp70 levels and TNF-α, TNFRI, IL-1β, IL-12, GOT, GPT, LDH, and uric acid concentrations in early-onset PE group. Thus, early-onset PE was associated with greater maternal and fetal impairment. There are differences in pathophysiology between early- and late-onset PE, highlighting by the difference in Hsp70 levels.

Role of microparticles in recurrent miscarriages and other adverse pregnancies: a review

The multiple functions attributed to microparticles (MPs) include blood coagulation, inflammation, tumorigenesis, angiogenesis, immunomodulatory functions and intercellular cross talk. These have drawn considerable interest during the last few years. The prothrombotic nature of MPs has linked them with almost all groups of thrombotic disorders including recurrent miscarriage (RM) and other abnormal pregnancy outcomes. Two authors (SS and RP) conducted a search independently on the computerized databases MEDLINE and EMBASE using relevant key words. Contradictory reports were observed on the association of MPs with RM. While most of the reports showed increased prevalence of MPs, both platelet and endothelial cell derived, in RM, some did not show any association. Almost all the reports showed a strong association of MPs with preeclampsia (PE), while the association with other adverse pregnancy conditions was not very conclusive. It may be concluded that MPs by themselves may result in adverse conditions or that they may be additive factors to an already existing prothrombotic state due to acquired or genetic thrombophilia or some unknown thrombophilic condition, besides the pre-existing hypercoagulable status of pregnancy.

Silibinin attenuates oxidative metabolism and cytokine production by monocytes from preeclamptic women

Silibinin is a polyphenolic plant flavonoid with anti-inflammatory properties. The present study investigated the effect of silibinin on oxidative metabolism and cytokine production - tumor necrosis factor-alpha (TNF-α), interleukin (IL)12, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, IL-10, and transforming growth factor beta (TGF-β1) - by peripheral blood monocytes (PBM) from preeclamptic pregnant women. It is a case-controlled study involving women with preeclampsia (PE, n = 30) compared with normotensive pregnant (NT, n = 30) and with non-pregnant (NP, n = 30) women. Monocytes were obtained and cultured with or without silibinin (5 μM or 50 μM) for 18 h. Superoxide anion (O2-) and hydrogen peroxide (H2O2) release were determined by specific assays, and cytokine levels were determined by immunoenzymatic assays (ELISA). Monocytes from preeclamptic women cultured without stimulus released higher levels of O22, H2O2 and TNF-α, and lower levels of IL-10 and TGF-β1 than did monocytes from NT and NP women. Treatment in vitro with silibinin significantly inhibited spontaneous O2- and H2O2 release and TNF-α production by monocytes from preeclamptic women. The main effect of silibinin was obtained at 50 μM concentration. Thus, silibinin exerts anti-oxidative and anti-inflammatory effects on monocytes from preeclamptic pregnant women by inhibiting the in vitro endogenous release of reactive oxygen species and TNF-α production.

Inflammatory disturbances in preeclampsia: relationship between maternal and umbilical cord blood

Preeclampsia (PE) is one of the main causes of maternal and fetal mortality and morbidity. PE is associated with an inflammatory state and with oxidative stress, in maternal circulation. Our aim was to evaluate and compare the levels of oxidative stress and inflammatory markers in maternal and umbilical cord blood (UCB), in normal and PE pregnancies. We measured acute-phase proteins (CRP and α1-antitrypsin), proinflammatory cytokines (IL-6 and TNF-α), leukocyte activation (elastase, lactoferrin, sL-selectin, sVCAM, sPECAM), total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), and uric acid levels. We studied 42 healthy pregnant women, 46 PE women, and their neonates. The concentrations of IL-6, TNF-α, α1-antitrypsin, CRP, sVCAM, uric acid, and TBARS were significantly higher, and sL-selectin was significantly lower in PE pregnant women as compared with normotensive pregnant women. In newborns uric acid, α1-antitrypsin, and CRP values were significantly higher in PE; leukocyte count, sL-selectin, lactoferrin, and the ratio elastase/α1-antitrypsin were significantly lower. Our data suggest that PE pregnancy is associated with an enhanced maternal inflammatory condition, which is reflected in fetal circulation. This enhanced inflammatory state seems to be related to endothelial dysfunction and increased cytokine synthesis, rather than with neutrophil activation.

Leukocyte-derived microparticles in vascular homeostasis

Leukocyte-derived microparticles (LMPs) may originate from neutrophils, monocytes/macrophages, and lymphocytes. They express markers from their parental cells and harbor membrane and cytoplasmic proteins as well as bioactive lipids implicated in a variety of mechanisms, maintaining or disrupting vascular homeostasis. When they carry tissue factor or coagulation inhibitors, they participate in hemostasis and pathological thrombosis. Both proinflammatory and anti-inflammatory processes can be affected by LMPs, thus ensuring an appropriate inflammatory response. LMPs also play a dual role in the endothelium by either improving the endothelial function or inducing an endothelial dysfunction. LMPs are implicated in all stages of atherosclerosis. They circulate at a high level in the bloodstream of patients with high atherothrombotic risk, such as smokers, diabetics, and subjects with obstructive sleep apnea, where their prolonged contact with the vessel wall may contribute to its overall deterioration. Numbering microparticles, including LMPs, might be useful in predicting cardiovascular events. LMPs modify the endothelial function and promote the recruitment of inflammatory cells in the vascular wall, necessary processes for the progression of the atherosclerotic lesion. In addition, LMPs favor the neovascularization within the vulnerable plaque and, in the ruptured plaque, they take part in coagulation and platelet activation. Finally, LMPs participate in angiogenesis. They might represent a novel therapeutic tool to reset the angiogenic switch in pathologies with altered angiogenesis. Additional studies are needed to further investigate the role of LMPs in cardiovascular diseases. However, large-scale studies are currently difficult to set up because microparticle measurement still requires elaborate techniques which lack standardization.

Microparticles of pregnant women and preeclamptic patients activate endothelial cells in the presence of monocytes

PROBLEM

Preeclampsia is a pregnancy-specific disorder that may result from an adverse maternal response to circulating placenta-derived factors, causing a systemic inflammation including endothelial activation. Plasma from preeclamptic patients was shown to induce endothelial activation in the presence of monocytes. We investigated whether microparticles (MP) are the plasma factors causing this activation of endothelial cells.

METHOD OF STUDY

Monocultures and co-cultures of monocytes and endothelial cells were incubated with plasma, MP-poor plasma or isolated MP from non-pregnant and pregnant women and preeclamptic patients (each n = 8). ICAM-1 expression was analyzed with flow cytometry.

RESULTS

The expression of ICAM-1 was significantly increased in monocytes and endothelial cells in co-cultures after the addition of isolated MP from preeclamptic patients (P = 0.017) and to a lesser extent in pregnant women (P = 0.012) compared to non-pregnant controls.

CONCLUSIONS

Microparticles from preeclamptic patients activate endothelial cells in the presence of monocytes. Whether all MP have the same effect on monocytes and endothelial cells or only a specific subgroup is the focus of future research.

Increased reactive oxygen species and tumor necrosis factor-alpha production by monocytes are associated with elevated levels of uric acid in pre-eclamptic women

PROBLEM

To evaluate associations between hyperuricemia and increases in production of reactive oxygen species (ROS) and tumor necrosis factor alpha (TNF-α) in pre-eclamptic pregnancies.

METHOD OF STUDY

This study investigated serum uric acid levels, monocyte production of TNF-α, superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)), as well as superoxide dismutase (SOD) and catalase (CAT) activities in erythrocytes from 30 women with pre-eclampsia (PE) compared with 30 normotensive (NT) pregnant women in the last trimester of pregnancy.

RESULTS

Serum uric acid levels (6.1 versus 2.8 mg/dL) as well as endogenous O(2)(-) (2.2 versus 1.6 nm), H(2)O(2) (1.8 versus 1.4 nm) and TNF-α (91.6 versus 40.4 pg/mL) released from monocytes were significantly higher in the pre-eclamptic group than in the NT group (P < 0.05). SOD activity in erythrocytes was also significantly elevated in the PE group (5969.2 versus 4834.7 U/g Hb). No significant difference between groups was observed in relation to CAT activity.

CONCLUSIONS

Elevated serum uric acid levels are correlated with higher O(2)(-) and TNF-α production by monocytes in women with PE. This may contribute to the enhanced oxidative and inflammatory state characteristic of this disorder.