Upregulation of exofacial peroxiredoxin-thioredoxin system of lymphocytes and monocytes in preeclampsia.

OBJECTIVES: An imbalanced redox homeostasis resulting in oxidative stress is present in preeclampsia. Peroxiredoxin-1 (PRDX1) and thioredoxin-1 (TRX1) regulatory enzymes are also contributing to the redox homeostasis, but were not investigated so far in preeclampsia. Thus, we have aimed to characterize PRDX1, TRX1 and oxidative stress biomarkers in blood samples of pregnant women with preeclampsia. STUDY DESIGN: Twelve patients with preeclampsia (PE) were enrolled into the study. Seven third trimester healthy pregnant women (HP) were accepted as control group. MAIN OUTCOME MEASURES: Peripheral venous blood samples of healthy and preeclamptic pregnant women were analyzed. Plasma level of advanced oxidation protein products (AOPP) was determined by spectrophotometry. The exofacial PRDX1 and TRX1 expression of lymphocytes and monocytes was detected by flow cytometry. RESULTS: The plasma AOPP level was significantly higher in preeclampsia compared to the healthy pregnant group. Significantly higher percentage of PRDX1 and TRX1 expressing lymphocytes and monocytes were detected in the blood samples of preeclamptic women compared to healthy pregnant controls. The ratio of circulating PRDX1 and TRX1 expressing lymphocytes and monocytes showed a significant inverse correlation with the birth weight of newborns. CONCLUSIONS: We have revealed that the level of advanced oxidation protein products is increased and the exofacial peroxiredoxin-1 and thioredoxin-1 system in lymphocytes and monocytes is upregulated in preeclampsia. In addition, the ratio of peroxiredoxin-1 and thioredoxin-1 positive circulating lymphocytes and monocytes correlates inversely with the neonatal birth weight, which finding indicates that pregnancies complicated by intrauterine growth restriction are accompanied by a higher level of oxidative stress.

Platelet-derived extracellular vesicles may contribute to the hypercoagulable state in preeclampsia.

It has previously been shown that preeclampsia is associated with disturbed hemostasis and that extracellular vesicles (EVs) play important role in the regulation of hemostatic homeostasis. Thus, we hypothesized that the altered procoagulant characteristics of circulating platelet-derived EVs may contribute to the disturbed hemostasis in preeclampsia. Using multicolor flow cytometry, we have analyzed both tissue factor expressing procoagulant EVs and platelet-derived EV subpopulations derived from resting and activated thrombocytes by examining them in plasma samples of preeclamptic patients and pregnancy-matched healthy individuals. Compared to pregnancy-matched healthy individuals in preeclamptic patients a significantly (p < 0.05) higher ratio of Annexin-V positive activated platelets and a higher number of CD142+ tissue factor bearing procoagulant EVs were found, whereas the absolute amount of circulating CD41a+ platelet-derived EVs and CD62P+/CD41a+ EVs produced by activated thrombocytes was significantly lower in the plasma of preeclamptic women. In the plasma samples, there was no significant difference in the amount of CD63+ platelet-derived EVs. We propose that increased platelet activation and tissue factor expression of platelet derived extracellular vesicles may contribute to the hypercoagulable state observed in preeclampsia.

Pravastatin induces NO synthesis by enhancing microsomal arginine uptake in healthy and preeclamptic placentas.

BACKGROUND: Pravastatin, a known inducer of endothelial nitric-oxide synthase (eNOS) was demonstrated in human placenta, however the exact mechanism of it's action is not fully understood. Since placental NO (nitric oxide) synthesis is of primary importance in the regulation of placental blood flow, we aimed to clarify the effects of pravastatin on healthy (n = 6) and preeclamptic (n = 6) placentas (Caucasian participants). METHODS: The eNOS activity of human placental microsomes was determined by the conversion rate of C14 L-arginine into C14 L-citrulline with or without pravastatin and Geldanamycin. Phosphorylation of eNOS (Ser1177) was investigated by Western blot. Microsomal arginine uptake was measured by a rapid filtration method. RESULTS: Pravastatin significantly increased total eNOS activity in healthy (28%, p<0.05) and preeclamptic placentas (32%, p<0.05) using 1 mM Ca2+ promoting the dissociation of a eNOS from it's inhibitor caveolin. Pravastatin and Geldanamycin (Hsp90 inhibitor) cotreatment increased microsomal eNOS activity. Pravastatin treatment had no significant effects on Ser1177 phosphorylation of eNOS in either healthy or preeclamptic placentas. Pravastatin induced arginine uptake of placental microsomes in both healthy (38%, p < 0.05) and preeclamptic pregnancies (34%, p < 0.05). CONCLUSIONS: This study provides a novel mechanism of pravastatin action on placental NO metabolism. Pravastatin induces the placental microsomal arginine uptake leading to the rapid activation of eNOS independently of Ser1177 phosphorylation. These new findings may contribute to better understanding of preeclampsia and may also have a clinical relevance.

Circulating exosomal and Argonaute-bound microRNAs in preeclampsia.

INTRODUCTION: microRNAs (miRNAs) play important role in the regulation of placental development, and abnormal miRNA expression is associated with preeclampsia (PE). miRNAs are released from trophoblast cells to maternal blood flow, where they are highly stable, being encapsulated inside extracellular vesicles, like exosomes or bound to Argonaute proteins. In PE, placental dysfunction leads to aberrant extracellular miRNA secretion. hsa-miR-210 is a hypoxia-sensitive miRNA found to be upregulated in PE; however, it is unknown whether it is the cause or the consequence of the disease. OBJECTIVE: Our aim was to analyze the expression of several miRNAs, including hsa-miR-210 in placenta, exosome and Ago-bound fractions comparing normal (N) and PE pregnancies. We performed in vitro analyses of extracellular hsa-miR-210 secretion of trophoblast cell cultures (of villous and extravillous origin) under hypoxic condition. METHODS: PE and N placenta samples were collected from C-sections, and blood samples were drawn from each pregnant woman in the third trimester. HTR-8 and JAR cell lines were cultured in exosome-free media and treated with hypoxia-mimetic agents. Exosome and Ago-bound fractions were isolated by membrane affinity spin column method from plasma and cell media. Short RNAs were extracted from exosomes and vesicle-free fractions, and total-RNA was isolated from the placenta samples. The RNA purity and concentration were measured by spectrophotometry. Expression analysis was carried out by qPCR with specific primers to target and reference miRNAs. RESULTS: The level of hsa-miR-210 was significantly higher in PE placentas, which could cause a minor increase of exosomal and a high elevation of Ago-bound miR-210 in circulation. Hypoxia lead to intracellular hsa-miR-210 upregulation in trophoblast cell lines. In extravillous cell (HTR-8) media, only the level of exosomal hsa-miR-210 was increased but no change in Ago-bound hsa-miR-210 level was observed. In contrast, in villous cell (JAR) media, the level of exosomal hsa-miR-210 was increased and enhanced release of Ago-bound hsa-miR-210 was also observed. CONCLUSION: Based on our data, we postulate that in PE, exosomal hsa-miR-210 is secreted actively from the trophoblast, and by intercellular communication, it may have a role in disease etiology. In addition, there is a passive release of Ago-bound hsa-miR-210 into the circulation, which may represent by-products of cell-death and is thereby a possible consequence of the disease.

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

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

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.

Various levels of circulating exosomal total-miRNA and miR-210 hypoxamiR in different forms of pregnancy hypertension.

INTRODUCTION: Hypertension is a common complication during pregnancy, affecting 10% of pregnant women worldwide. Several microRNA (miRNA) were shown to be involved in hypertensive disorders of pregnancy. In preeclampsia (PE), placental dysfunction causes the enhanced release of extracellular vesicle-derived miRNAs. The hypoxia-sensitive hsa-mir-210 is the most common PE-associated miRNA, but its exosomal profile has not been investigated. OBJECTIVES: Our aims were to measure exosomal total-miRNA concentration and to perform expression analysis of circulating exosomal hsa-miR-210 in women affected by chronic hypertension (CHT) gestational hypertension (GHT) or PE. MATERIALS AND METHODS: We collected plasma samples from women with CHT, GHT, PE (moderate: mPE and severe: sPE) and from normotensive pregnancies. Exosomal miRNAs were extracted and miRNA concentration was measured. RT-PCR was carried out with hsa-miR-210-3p-specific primers and relative expression was calculated using the comparative Ct method. RESULTS: The total-miRNA concentration was different in the disease subgroups, and was significantly higher in mPE and sPE compared to the other groups. We found a significant difference in the relative exosomal hsa-miR-210-3p expression between all hypertensive groups compared to the normotensive samples, but significant upregulation was only observed in case of mPE and sPE patients. Both the level of total-miRNA and hsa-miR-210 expression was higher in case of severe PE. CONCLUSIONS: The level of circulating exosomal total-miRNA and hsa-miR-210 was elevated in women with PE, and it was higher in the severe form. We showed that hsa-miR-210 is secreted via exosomes, which may have a role in the pathomechanism of the disease.

[The role of angiogenic factors in preeclampsia]. / Az angiogén faktorok szerepe praeeclampsiában.

Preeclampsia is one of the most common and most serious complications of pregnancy and the management of this condition still challenges obstetricians. Despite intensive research the etiology of preeclampsia still remains unclear. At the beginning of the 2000s preeclampsia-related research was directed towards factors that influence angiogenesis. Most studies have been carried out on the placental growth factor and soluble fms-like tyrosine kinase-1. Most publications confirm the increased concentrations of antiangiogenic factors and decreased concentrations of proangiogenic factors in maternal blood samples in preeclampsia even before the onset of clinical symptoms. According to our current knowledge antiangiogenic proteins are responsible for the endothelial dysfunction in the symptomatic stage of the disease. Placental growth factor and soluble fms-like tyrosine kinase-1 may have important roles in the prediction and treatment of the disease. The point of care detection of placental growth factor and soluble fms-like tyrosine kinase-1 may be used to predict preeclampsia. Rapid tests are available to determine the serum levels of the two proteins. Removal of soluble fms-like tyrosine kinase-1 from maternal circulation is a potential treatment option for early onset preeclampsia.

[Screening of trisomy 21 nowadays. Is maternal age so important?]. / A 21-es triszómia szurése napjainkban. Az anyai életkor valóban olyan fontos?

INTRODUCTION: Trisomy 21 is the most common chromosomal abnormality, therefore, screening and diagnosis of this disorder is in the centre of attention worldwide. An efficient screening method is the combined test based on maternal age, ultrasound signs, biochemical markers, and a risk ratio can be calculated based on these data. AIM: The aim of the authors was to determine the causes of missed prenatal diagnosis of Down's syndrome at the 2nd Department of Obstetrics and Gynecology, Semmelweis University. METHOD: A retrospective study was carried out by collecting data from medical records of mothers who had delivered a newborn with Down's syndrome in the Department between 2008 and 2012. Each medical record was analyzed individually. RESULTS: In most cases the missed diagnosis of Down's syndrome occurred when the expectant mother failed to attend the first trimester screening or did not take the risk of invasive diagnostic procedures needed for fetal kariotyping. CONCLUSIONS: Analysis of fetal DNA circulating in maternal plasma can be a solution for those who refuse invasive fetal diagnostics. This test has high sensitivity and very low false positive rate. It has become available since the end of 2011 in the United States and, since the autumn of 2012, in Hungary, too. The test, however, is not reimbursed by national health insurance.

[The pathophysiology of preeclampsia in view of the two-stage model]. / A praeeclampsia kórélettana a kétlépcsos modell tükrében.

Preeclampsia is a common and severe disease in pregnancy, a major cause of maternal and fetal morbidity and mortality. The main features of the disease are de novo hypertension after the 20th gestational week and proteinuria, and it is frequently accompanied by edema and other subjective symptoms. The origin of the disease is the placenta, but its sequelae affect multiple organ systems. According to the two-stage model of preeclampsia, the abnormal and hypoperfused placenta (stage 1) releases factors to the bloodstream, which are responsible for the maternal symptoms (stage 2). Oxidative stress, impaired function of nitric-oxide synthase, cellular and humoral immunological factors play an important role in the pathophysiology of the placenta. Endothelial dysfunction is the common denominator of the clinical symptoms. The theory explains the origins of hypertension, proteinuria, edema and other symptoms as well.