Maternal Endothelial Dysfunction Research Articles

Heme Oxygenase-1 Attenuates Hypoxia-Induced sFlt-1 and Oxidative Stress in Placental Villi through Its Metabolic Products CO and Bilirubin

One of the most prevalent complications of pregnancy is preeclampsia, a hypertensive disorder which is a leading cause of maternal and perinatal morbidity and premature birth with no effective pharmacological intervention. While the underlying cause is unclear, it is believed that placental ischemia/hypoxia induces the release of factors into the maternal vasculature and lead to widespread maternal endothelial dysfunction. Recently, HO-1 has been shown to downregulate two of these factors, reactive oxygen species and sFlt-1, and we have reported that HO-1 induction attenuates many of the pathological factors of placental ischemia experimentally. Here, we have examined the direct effect of HO-1 and its bioactive metabolites on hypoxia-induced changes in superoxide and sFlt-1 in placental vascular explants and showed that HO-1 and its metabolites attenuate the production of both factors in this system. These findings suggest that the HO-1 pathway may be a promising therapeutic approach for the treatment of preeclampsia.

Nitric oxide generation affects pro- and anti-angiogenic growth factor expression in primary human trophoblast

ObjectivesPreeclampsia is associated with reduced trophoblast placenta growth factor (PGF) expression, elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased bioactivity of nitric oxide (NO). Elevated sFlt-1 reduces bio-availability of PGF and vascular endothelial growth factor (VEGF) leading to maternal endothelial dysfunction. Although NO can regulate gene expression, its ability to regulate trophoblast expression of angiogenic growth factors is not known. Study designHuman primary term trophoblast and JEG-3 choriocarcinoma cells were cultured under 21%O2 or 1%O2 conditions in the presence or absence of NO donor (SNP) or inhibitor (L-NAME). Effects on PGF, VEGF and Flt-1 isoform mRNA expression were determined by quantitative real-time PCR. Changes in expression of soluble protein isoforms of FLT-1 was monitored by ELISA. ResultsHypoxia decreased PGF mRNA but increased VEGF, sFlt-1 and Flt-1 mRNA expression in trophoblast. Generation of NO in trophoblast under 1%O2 culture conditions significantly reversed sFlt-1 mRNA and protein expression, independent of mFlt-1. Conversely NO generation in hypoxic trophoblast increased VEGF and PGF mRNA expression. ConclusionsNO production in primary human trophoblast cultures had divergent effects on pro-angiogenic (PGF, VEGF) versus anti-angiogenic (sFlt-1) mRNA expression, resulting in an enhanced pro-angiogenic gene expression environment in vitro.

Peroxisome Proliferator-Activated Receptor-γ as a Potential Therapeutic Target in the Treatment of Preeclampsia

Preeclampsia is a multisystemic disorder of pregnancy characterized by hypertension, proteinuria, and maternal endothelial dysfunction. It is a major cause of maternal and perinatal morbidity and mortality and is thought to be attributable, in part, to inadequate trophoblast invasion. Peroxisome proliferator-activated receptor-γ (PPAR-γ) is a ligand-activated transcription factor expressed in trophoblasts, and the vasculature of which activation has been shown to improve endothelium-dependent vasodilatation in hypertensive conditions. We investigated the effects of the administration of a PPAR-γ agonist using the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. The selective PPAR-γ agonist, rosiglitazone, was administered to pregnant rats that had undergone RUPP surgery. To investigate whether any observed beneficial effects of PPAR-γ activation were mediated by the antioxidant enzyme, heme oxygenase 1, rosiglitazone was administered in combination with the heme oxygenase 1 inhibitor tin-protoporphyrin IX. RUPP rats were characterized by hypertension, endothelial dysfunction, and elevated microalbumin:creatinine ratios. Rosiglitazone administration ameliorated hypertension, improved vascular function, and reduced the elevated microalbumin:creatinine ratio in RUPP rats. With the exception of microalbumin:creatinine ratio, these beneficial effects were abrogated in the presence of the heme oxygenase 1 inhibitor. Administration of a PPAR-γ agonist prevented the development of several of the pathophysiological characteristics associated with the RUPP model of preeclampsia, via a heme oxygenase 1-dependent pathway. The findings from this study provide further insight into the underlying etiology of preeclampsia and a potential therapeutic target for the treatment of preeclampsia.

Preeclampsia, a disease of the maternal endothelium: the role of antiangiogenic factors and implications for later cardiovascular disease.

Preeclampsia is a clinical syndrome defined as the new onset of hypertension and proteinuria during the second half of pregnancy.1 It afflicts 3% to 5% of pregnancies and is a leading cause of maternal mortality, especially in developing countries.2,3 Because the only known remedy is delivery of the placenta, in developed countries preeclampsia is an important cause of premature delivery, usually medically indicated for the benefit of the mother. This results in infant morbidity and substantial healthcare expenditure.4 Despite the considerable morbidity and mortality, the cause of preeclampsia has remained enigmatic. Both hypertension and proteinuria implicate the endothelium as the target of the disease. The hypertension of preeclampsia is characterized by peripheral vasoconstriction and decreased arterial compliance.5,6 The proteinuria of preeclampsia is associated with a pathognomonic renal lesion known as glomerular endotheliosis, in which the endothelial cells of the glomerulus swell and endothelial fenestrations are lost.7,8 Podocyturia has been recently associated with preeclampsia during clinical disease9; however, whether this is the cause or effect of proteinuria is unknown. The glomerular filtration rate is decreased compared with normotensive pregnant women; in rare cases, acute renal failure may develop. Preeclampsia is a systemic vascular disorder that may also affect the liver and the brain in the mothers. When the liver is involved, women may present with abdominal pain, nausea, vomiting, and elevated liver enzymes. Pathological examination of the liver reveals periportal and sinusoidal fibrin deposition and, in more extreme cases, hemorrhage and necrosis.10 The severe preeclampsia variant HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) occurs in ≈20% of women with severe preeclampsia,11 and is named not only for the liver involvement, but also for the disorder of the coagulation system that develops.12 Approximately 20% of …

Endothelin: Key Mediator of Hypertension in Preeclampsia

Preeclampsia is a pregnancy-induced hypertensive disorder characterized by proteinuria and widespread maternal endothelial dysfunction. It remains one of the most common disorders in pregnancy and remains one of the leading causes of maternal and fetal morbidity. Recent research has revealed that placental insufficiency, resulting in hypoxia and ischemia, is a central causative pathway in the development of the disorder. In response, the placenta secretes soluble substances into the maternal circulation which are responsible for the symptomatic phase of the disease. Among the most well characterized factors in the disease pathology are the anti-angiogenic protein soluble fms-like tyrosine kinase-1 (sFlt-1), inflammatory cytokines, and agonistic angiotensin II type-1 receptor autoantibodies. Each of these factors has been shown to induce hypertension experimentally through the production of endothelin-1 (ET-1), a powerful vasoconstrictor. Antagonism of the endothelin-A receptor has proved beneficial in numerous animal models of gestational hypertension, and it remains an intriguing target for pharmacological intervention in preeclampsia.

Changes in cardiac structure in hypertension produced by placental ischemia in pregnant rats: effect of tumor necrosis factor blockade

Chronic reduction of uteroplacental perfusion pressure (RUPP) in pregnant rats leads to placental ischemia, maternal endothelial cell dysfunction, hypertension and elevated levels of tumor necrosis factor-alpha (TNF-α). In this study we investigated the hypothesis that placental ischemia in pregnant rat, a model of preeclampsia, stimulates cardiac hypertrophy and fibrosis via a TNF-α-dependent mechanism. Normal pregnant Sprague-Dawley rats and RUPP rats were evaluated on day 19 of gestation. To test the role of TNF-α in mediating change in the RUPP rat heart, a TNF-α inhibitor, etanercept, was administered on day 18 of gestation at a dose of 0.8 mg/kg, s.c. In comparison to normal pregnant rats, RUPP animals display enlarged cardiomyocytes, microvascular rarefaction, fibrosis, apoptosis as well as increased expression of markers of heart hypertrophy and fibrosis. Etanercept (E) treatment prevented enlargement of cardiomyocytes, fibrosis and apoptosis and this was accompanied by significantly lowered blood pressure in RUPP rats. Etanercept treatment lowered expression of mRNA for brain natriuretic peptide, a marker of cardiac hypertrophy. It also heightened expression of endothelial nitric oxide synthase and its phosphorylation as well as oxytocin receptor identified in cardiac microvessels. TNF-α inhibition prevented microvascular rarefaction in the heart as indicated by augmented CD31, a marker of angiogenesis. These results suggest that RUPP leads to microvascular rarefaction in the heart, exaggerated cardiomyocyte size, apoptosis, fibrosis, and the alteration of cardiac gene expression that are modulated by the inflammatory cytokine TNFα.

Maternal endothelial dysfunction and its association with abnormal fetal growth in diabetic pregnancy

Some authors consider the vascular endothelium to be a target organ in diabetes. However, there have only been a few studies of the function of the maternal endothelium during pregnancy in women with diabetes. We analysed the relationship between maternal vascular endothelial dysfunction and fetal growth in such pregnancies. Markers of endothelial dysfunction (serum concentration of sE-selectin and sVCAM-1) were measured at admission (baseline) and before delivery in 97 women with pregestational diabetes and a singleton pregnancy,. After delivery, the group with pregestational diabetes was divided retrospectively according to neonatal birthweight into three groups-appropriate, small and large for gestational age- and the maternal variables were analysed in relation to birthweight. The baseline concentration of sE-selectin was significantly higher in the large-for-gestational-age group vs. the small-for-gestational-age group (median: 53.1 vs. 39.0 ng/ml, P<0.05). The concentration of sVCAM-1 at baseline was significantly higher in the small-for-gestational-age vs. the appropriate- and large-for-gestational-age groups (median: 846.2 vs. 576.8 and 524.1 ng/ml, respectively; P<0.01 and P<0.001, respectively). The concentration of sE-selectin at baseline and gestational changes in the concentration of sVCAM-1 were related to birthweight. The baseline concentrations of sE-selectin and sVCAM-1 and the gestational change in sVCAM-1 concentration were predictive factors for large for gestational age (cut-off values: 45.0, 644.6 and 38.4 ng/ml; sensitivity: 67.7, 89.3 and 34.4%; specificity: 65.5, 39.7 and 85.5%, respectively). Our study showed a relationship between maternal endothelial dysfunction and fetal growth disturbances during pregnancy in women with diabetes that was not associated with maternal metabolic control. Higher levels of maternal sE-selectin in early pregnancy were associated with increased risk of the large-for-gestational-age condition. High levels of maternal sVCAM-1 in early pregnancy were characteristic of gestation complicated by the small-for-gestational-age condition. Further studies in larger groups are warranted to determine whether markers of maternal endothelial dysfunction are of use in the prediction of abnormal birthweight (large or small for gestational age) in pregnant women with diabetes.

VEGF: a possible therapeutic for the treatment of preeclampsia?

Evaluation of: Woods AK, Hoffmann DS, Weydert CJ et al. Adenoviral delivery of VEGF121 early in pregnancy prevents spontaneous development of preeclampsia in BPH/5 mice. Hypertension 57(1), 94–102 (2011).Preeclampsia is a pregnancy-specific hypertension characterized by proteinuria and maternal endothelial dysfunction. Recent research has focused on the balance of pro- and anti-angiogenic factors in the development of the disorder, specifically the proteins VEGF, PlGF, sFlt-1 and sEng. In a recent paper, Woods et al. demonstrated that administration of adenovirally delivered VEGF attenuates the pathological features of preeclampsia that are present in a novel murine model of the disorder, the BPH/5 mouse. This is a recent addition to a body of literature that suggests an important role for VEGF bioavailability in the maintenance of a healthy endothelium during pregnancy, and suggests an intriguing target for the development of new therapeutics for the treatment of preeclampsia.

Multiple Reaction Monitoring Assay for Pre-eclampsia Related Calcyclin Peptides in Formalin Fixed Paraffin Embedded Placenta

Although the cause of pre-eclampsia during pregnancy has not been elucidated yet, it is evident that placental and maternal endothelial dysfunction is involved. We previously demonstrated that in early onset pre-eclampsia placental calcyclin (S100A6) expression is significantly higher compared to controls ( De Groot , C. J. ; Clin. Proteomics 2007 , 1 , 325 ). In the current study, the results were confirmed and relatively quantified by using multiple reaction monitoring (MRM) on two peptide fragments of calcyclin. Cells were obtained from control (n = 5) and pre-eclamptic placental (n = 5) tissue collected by laser capture microdissection from formalin-fixed paraffin-embedded (FFPE) material treated with a solution to reverse formalin fixation. Two calcyclin peptides with an extra glycine inserted in the middle of the amino acid sequence were synthesized and used as an internal reference. Data presented show that MRM on laser microdissected material from FFPE tissue material is possible. The developed MRM assay to study quantitative levels of proteins in FFPE laser microdissected cells using nonisotopic-labeled chemical analogs of mass tagged internal references showed that in pre-eclamptic patients elevated levels of calcyclin is observed in placental trophoblast cells compared to normal trophoblast cells. By immunohistochemistry, we were able to confirm this observation in a qualitative manner.

Fetal endothelium dysfunction is associated with circulating maternal levels of sE-selectin, sVCAM1, and sFlt-1 during pre-eclampsia

Objectives. To evaluate the association between endothelial activation markers in the maternal circulation with nitric oxide (NO) synthesis in human umbilical endothelial cells.Study design. This is a case-control study of normal and pre-eclamptic pregnancies. The levels of sE-selectin, soluble vascular cell adhesion molecule 1 (sVCAM-1), and soluble fms-like tyrosine kinase 1 (sFlt-1) were measured by enzyme-linked immunosorbent assay, and histamine-induced NO synthesis was detected by fluorometric examination of the human umbilical vein endothelial cells (HUVECs) isolated from normal and pathological pregnancies.Results. Mothers with severe pre-eclamptic pregnancies have premature and smaller babies than mothers with normal pregnancies (P < 0.05); they also have high maternal plasma levels of sVCAM-1 (∼2-fold), sFlt-1 (∼2.5-fold), and lower (∼70%) histamine-stimulated NO synthesis in HUVECs. A positive relationship between systolic blood pressure (SBP) and plasma levels of sE-selectin, sVCAM-1, and sFlt-1 was demonstrated. Moreover, levels of sE-selectin, sVCAM-1, and sFlt-1 were negatively associated with newborn weight (NBW), gestational age at delivery, and NO synthesis. Women with high E-selectin (>63 ng/ml), VCAM-1 (>752 ng/ml), and sFlt-1 (>15204 pg/ml) showed high risk (∼2-fold) for preterm delivery and very preterm delivery, or fetal weight <1500 g (∼1.5-fold) compared with women with low levels.Conclusions. High circulating levels of maternal endothelial dysfunction markers present in pre-eclampsia are associated with decreased NO synthesis in fetal endothelium.

The Functions of Microparticles in Pre-Eclampsia

Pre-eclampsia (P-EC), a heterogenic multisystem disorder characterized by hypertension and proteinuria, usually develops in the second half of pregnancy. The incidence is 2 to 5%, and P-EC is therefore a major cause of maternal and perinatal morbidity and mortality. Although the exact etiology is unknown, placental factors released into the maternal circulation lead to systemic maternal inflammation and endothelial dysfunction. Growing evidence indicates that placenta-derived microparticles, best known as syncytiotrophoblast microparticles (STBM), are important among these factors. This review provides an overview of the presence and function(s) of STBM and other cell-derived microparticles and exosomes.

HSP70-mediated control of endothelial cell apoptosis during pre-eclampsia

Objective Pre-eclampsia is a hypertensive disorder characterized by maternal vascular endothelial dysfunction. It is likely that this enhanced rate of endothelial cell stress is associated with the pre- and post-partum complications of both mother and fetus. Deciphering the expression pattern of factors involved in altering placental endothelial cell viability in pre-eclampsia aids in identifying components that may protect the fetus from the consequences of placental dysfunction and oxidative stress. Study design Expression of thioredoxin (Trx), an antioxidant protein; heat shock protein (HSP) 70, a cytoprotective protein; heat shock factor (HSF)1, a transcriptional factor of HSPs; and apoptosis signal-regulating kinase 1 (ASK1), a pro-apoptotic protein, was elucidated in endothelial cells from human term placentas of normotensive and pre-eclamptic subjects ( n = 35). Results A significant increase in HSP70 ( p < 0.05), HSF1 ( p < 0.05), Trx ( p < 0.05) and an insignificant increase in ASK1 were noted in pre-eclamptic endothelial cells. Conclusion This analysis supports the role of HSP70 expression in promoting cell survival by regulating ASK expression in pre-eclampsia.

Long-Term Complications of Preeclampsia

Preeclampsia is a multi-organ syndrome of pregnancy, defined by the new onset of hypertension and proteinuria after 20 weeks' gestation. This working definition ignores the variable multi-organ involvement of a syndrome that can include seizures in the absence of hypertension, or fulminating hepatic necrosis in the absence of proteinuria. These disparate clinical features are akin to an accelerated metabolic syndrome with widespread maternal endothelial dysfunction in the presence of a relatively underperfused placenta. Delivery of the placenta remains the only cure, but years after a pregnancy complicated by preeclampsia, women are at increased risk of chronic hypertension, diabetes mellitus, ischemic heart disease, cerebrovascular disease, kidney disease, thromboembolism, hypothyroidism, and even impaired memory. This article describes how pregnancy propels vulnerable women toward preeclampsia and how a brief, usually single, episode of this acute pregnancy syndrome defines those vulnerable to chronic disease in later life.

Angiogenic Factors and Preeclampsia

Preeclampsia, a hypertensive disorder peculiar to pregnancy, is a systemic syndrome that appears to originate in the placenta and is characterized by widespread maternal endothelial dysfunction. Until recently, the molecular pathogenesis of phenotypic preeclampsia was largely unknown, but recent observations support the hypothesis that altered expression of placental anti-angiogenic factors are responsible for the clinical manifestations of the disease. Soluble Flt1 and soluble endoglin, secreted by the placenta, are increased in the maternal circulation weeks before the onset of preeclampsia. These anti-angiogenic factors produce systemic endothelial dysfunction, resulting in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, and as of 2011 the role of angiogenic proteins in early placental vascular development was starting to be explored. The data linking angiogenic factors to preeclampsia have exciting clinical implications, and likely will transform the detection and treatment of preeclampsia.

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

AimsPre-eclampsia affects 5–7% of pregnancies, and is a major cause of maternal and foetal death. Elevated serum levels of placentally derived splice variants of the vascular endothelial growth factor (VEGF) receptor, soluble fms-like tyrosine kinase-1 (sFLT1), are strongly implicated in the pathogenesis but, as yet, no underlying mechanism has been described. An excessive inflammatory-like response is thought to contribute to the maternal endothelial cell dysfunction that characterizes pre-eclampsia. We hypothesized that sFLT1 antagonizes autocrine VEGF-A signalling, rendering endothelial cells more sensitive to pro-inflammatory factors also released by the placenta. We tested this by manipulating VEGF receptor signalling and treating endothelial cells with low doses of tumour necrosis factor-α (TNF-α).Methods and resultsApplication of recombinant sFLT1 alone did not activate human umbilical vein endothelial cells (HUVECs). However, antagonizing the autocrine actions of endothelial VEGF-A and/or placenta growth factor (PlGF) by pre-incubation with recombinant sFLT1, anti-FLT1, anti-VEGF receptor 2 (KDR), anti-VEGF-A, VEGF receptor tyrosine kinase inhibitor SU5614, or knocking-down FLT1 or KDR transcripts rendered cells more sensitive to low doses of TNF-α. Each treatment increased activation, as measured by increases in endothelial intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), endothelin 1 (ET-1), von Willebrand factor (vWF), and leucocyte adhesion, and led to reduction in AKT Ser473 and endothelial nitric oxide synthase (eNOS) Ser1177 phosphorylation.ConclusionsOur data describe a mechanism by which sFLT1 sensitizes endothelial cells to pro-inflammatory factors, providing an explanation for how placental stress may precipitate the pre-eclamptic syndrome.

Protein composition of microparticles shed from human placenta during placental perfusion: Potential role in angiogenesis and fibrinolysis in preeclampsia

Shedding of syncytiotrophoblast microparticles (MPs) from placenta to maternal blood occurs in normal pregnancy and is enhanced during preeclampsia (PE). The syncytiotrophoblast synthesizes plasminogen activator inhibitors (PAIs) which regulate fibrinolysis, as well as soluble forms of the fms-like tyrosine kinase (sFlt-1) and endoglin, which exert anti-angiogenic actions. An increase in the ratio of PAI-1/PAI-2 and elevated levels of sFlt-1 and sEng in maternal serum are linked to placental damage and maternal endothelial cell dysfunction in PE. The goal of the current study was to determine whether MPs released to maternal perfusate during dual perfusion contain these factors associated with placental pathophysiology in PE. Initially, high levels of alkaline phosphatase activity and Annexin V binding were found in MPs isolated by sequential centrifugation of maternal perfusates at 10,000 and 150,000×g(10 K and 150 K MPs), indicating their plasma membrane origin. ELISA revealed the presence of these factors at the following relative levels: Eng>PAI-2⋙PAI-1>sFlt-1. Based on comparisons of their concentration in perfusates, MPs, and MP-free 150 K supernatants, we determined that MPs constitute a significant portion of Eng released by placenta. Flow cytometric analysis of 10 K MPs supported the levels of expression found by ELISA and indicated that Eng and PAI-2 were almost exclusively localized to the surface of MPs, a site with biological potential. These results indicate that MPs shed from the syncytial surface express factors which may alter the fibrinolytic and angiogenic balance at the maternal–fetal interface and play a role in the pathophysiology of PE.

W6.4 Plasma ADMA is elevated throughout pregnancy in women who develop preeclampsia and is accentuated by pre-pregnancy obesity

W6.4 Plasma ADMA is elevated throughout pregnancy in women who develop preeclampsia and is accentuated by pre-pregnancy obesity

W6.2 High prepregnancy body mass index is associated with low PlGF in preeclampsia and uncomplicated pregnancies

W6.4 – Table 1 Group 4 to 15 weeks gestation 15.1 to 25 weeks gestation 25.1 to 33 weeks gestation 33.1 to 42 weeks gestation Lean/Control 0.32 [0.27-0.39] 0.30 [0.24-0.36] 0.31 [0.25-0.36] 0.34 [0.28-0.39] Overweight-Obese/Control 0.39 [0.34-0.47]* 0.42 [0.37-0.48]* 0.40 [0.35-0.46]* 0.43 [0.35-0.49]* Lean/Preeclampsia 0.44 [0.37-0.51]* 0.39 [0.30-0.48]* 0.44 [0.36-0.49]* 0.48 [0.37-0.55]* Overweight-Obese/Preeclampsia 0.44 [0.36-0.54]*# 0.47 [0.41-0.51]* 0.54 [0.46-0.58]*# 0.51 [0.43-0.56]*# Data are median [interquartile range], *p 25 kg/m2. Obesity may influence the risk of preeclampsia by negatively affecting maternal PlGF concentrations. Supported by National Institutes of Health grant number P01-HD30367 and Abbott Laboratories. W6.3 Central adiposity influences the lipid response to pregnancy and is associated with reduced vascular function Eleanor Jarvie, Frances Stewart, Muriel Caslake, Jane Ramsay, William Ferrell, Dilys Freeman. University of Glasgow, Glasgow, UK Central adiposity is a risk factor for pre-eclampsia. Maternal obesity is associated with an inappropriate metabolic adaptation to pregnancy which may provoke the maternal endothelial dysfunction characteristic of preeclampsia. Adipose tissue depots have different metabolic activities and location of fat storage either at the outset of pregnancy or accumulated during pregnancy may be critical to the gestational metabolic response. We examined whether body fat distribution at booking determines the metabolic response to pregnancy and vascular function. In 60 women at booking, upper body subcutaneous (USAT) and visceral adipose tissue (UVAT) thicknesses were assessed by ultrasound. Lower body subcutaneous fat (LSAT) was assessed by hip circumference. Endothelium-dependent microvascular function (EDMVF) determined by laser Doppler iontophoresis and plasma markers of lipid & carbohydrate metabolism and inflammation were assessed in the 1st, 2nd and 3rd trimester. Baseline USAT is positively associated with baseline inflammatory status and contributes to 8.4% (p=0.009) and 11.2% (p=0.004) of the variation in baseline IL-6 and CRP respectively, independent of other adipose tissue depots. Baseline UVAT is negatively associated with baseline EDMVF (7.7%, p=0.025). UVAT is associated with an increased sVCAM-1 exposure [total area under the curve (AUC) 30.0%, p=0.003] and USAT is associated with a reduction in EDMVF (9.9%, p=0.027) throughout pregnancy. Lipid mobilisation, assessed as incremental AUC of VLDL-1 (p=0.005) and VLDL-2 (p=0.004) concentrations, was lower in women with large UVAT but higher in those with large USAT (p=0.014). UVAT is associated with endothelial activation and a less flexible lipid response to pregnancy. USAT is related to chronic inflammation at the outset and with poor microvascular function over the course of pregnancy. Upper body adiposity influences the metabolic and vascular adaptation to pregnancy and may be the mechanism by which maternal central adiposity increases risk of preeclampsia. W6.4 Plasma ADMA is elevated throughout pregnancy in women who develop preeclampsia and is accentuated by pre-pregnancy obesity Robert Powers, James Roberts, Arun Jeyabalan, Robin Gandley, Carl Hubel. University of Pittsburgh, USA Context: Vascular dysfunction is an important aspect of the pathophysiology of preeclampsia. Pre-pregnancy obesity is an independent risk factor for preeclampsia. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. ADMA is an emerging risk factor for vascular disease and is elevated in obesity. Objective: The aim of the study was to investigate the concentration of maternal ADMA across pregnancy, and the association of ADMA to obesity and pregnancy outcome. Study design: Maternal plasma ADMA was quantified by HPLC in longitudinal samples from 50 women who developed preeclampsia and 100 controls who remained normotensive. Data were analyzed by ANOVA and significance accepted at p<0.05. Results: Maternal plasma ADMA was significantly elevated throughout pregnancy in subjects who developed preeclampsia compared to controls (p<0.01). ADMA was significantly elevated in overweight-obese controls compared to lean controls throughout pregnancy (p<0.05, table). ADMA was significantly elevated throughout pregnancy among lean subjects who developed preeclampsia compared to lean controls (p<0.05, table). ADMA was also significantly elevated among overweight-obese subjects who

Interleukin-10 inhibits the in vivo and in vitro adverse effects of TNF-α on the endothelium of murine aorta

TNF-α is a proinflammatory cytokine and is an important mediator of maternal endothelial dysfunction leading to preeclampsia. In this study, we tested whether IL-10 protects against TNF-α-induced endothelial dysfunction in murine aorta. In in vitro experiments, aortic rings of C57BL/6 female mice were incubated in Dulbecco's modified Eagle's medium in the presence of either vehicle (distilled H(2)O), TNF-α (4 nmol/l), or recombinant mouse IL-10 (300 ng/ml) or in the presence of both TNF-α and IL-10 for 22 h at 37°C. In in vivo experiments C57BL6/IL-10 knockout female mice were treated with saline or TNF-α (220 ng·kg(-1)·day(-1)) for 14 days. Aortic rings were isolated from in vitro and in vivo experiments and mounted in a wire myograph (Danish Myotech) and stretched to a tension of 5 mN. Endothelium-dependent relaxation was assessed by constructing cumulative concentration-response curves to acetylcholine (ACh, 0.001-10 μmol/l) during phenylephrine (10 μmol/l)-induced contraction. As a result, overnight exposure of aortic rings to TNF-α resulted in significant blunted maximal relaxing responses (E(max)) to ACh compared with untreated rings (22 ± 4 vs. 82 ± 3%, respectively). IL-10 knockout mice treated with TNF-α showed significant impairment in ACh responses (E(max)) compared with C57BL/6 mice treated with TNF-α (51 ± 3 vs. 72 ± 3%, respectively). Western blot analysis showed that endothelial nitric oxide synthase (eNOS) expression was reduced by TNF-α in in vitro and in vivo experiments, whereas IL-10 restored the eNOS expression. In conclusion, the anti-inflammatory cytokine IL-10 prevents impairment in endothelium-dependent vasorelaxation caused by TNF-α by protecting eNOS expression.

Dysregulated Complement Activation as a Common Pathway of Injury in Preeclampsia and Other Pregnancy Complications

The complement system protects the host against invading organisms, initiates inflammation and dispose of immune complexes and the products of inflammatory injury. The complement system provides an important link between the innate and adaptive immune systems. Experimental observations suggest that increased complement activation causes and/or perpetuates inflammation during pregnancy. Recent studies suggest a link between complement activation and preeclampsia. Excessive activation or insufficient regulation of complement recruits leukocytes and unleashes potent inflammatory and anti-angiogenic mediators associated with placental insufficiency and maternal endothelial dysfunction characteristic of preeclampsia. We review the animal and human studies that link complement activation and pathogenic events in preeclampsia, present evidence that activation of the complement system is associated with the development of preeclampsia and provides new targets to prevent its complications.