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BACKGROUND: Preeclampsia is a serious condition of pregnancy, complicated by aberrant maternal vascular dysfunction. CNP (C-type natriuretic peptide) contributes to vascular homeostasis, acting through NPR-B (natriuretic peptide receptor-B) and NPR-C (natriuretic peptide receptor-C). CNP mitigates vascular dysfunction of arteries in nonpregnant cohorts; this study investigates whether CNP can dilate maternal arteries in ex vivo preeclampsia models. METHODS: Human omental arteries were dissected from fat biopsies collected during cesarean section. CNP, NPR-B, and NPR-C mRNA expression was assessed in arteries collected from pregnancies complicated by preeclampsia (n=6) and normotensive controls (n=11). Using wire myography, we investigated the effects of CNP on dilation of arteries from normotensive pregnancies. Arteries were preconstricted with either serum from patients with preeclampsia (n=6) or recombinant ET-1 (endothelin-1; vasoconstrictor elevated in preeclampsia; n=6) to model vasoconstriction associated with preeclampsia. Preconstricted arteries were treated with recombinant CNP (0.001-100 µmol/L) or vehicle and vascular relaxation assessed. In further studies, arteries were preincubated with NPR-B (5 µmol/L) and NPR-C (10 µmol/L) antagonists before serum-induced constriction (n=4-5) to explore mechanistic signaling. RESULTS: CNP, NPR-B, and NPR-C mRNAs were not differentially expressed in omental arteries from preeclamptic pregnancies. CNP potently stimulated maternal artery vasorelaxation in our model of preeclampsia (using preeclamptic serum). Its vasodilatory actions were driven through the activation of NPR-B predominantly; antagonism of this receptor alone dampened CNP vasorelaxation. Interestingly, CNP did not reduce ET-1--driven omental artery constriction. CONCLUSIONS: Collectively, these data suggest that enhancing CNP signaling through NPR-B offers a potential therapeutic strategy to reduce systemic vascular constriction in preeclampsia. [ABSTRACT FROM AUTHOR]

Mucins are a family of proteins that protect the epithelium. A particular type of mucin, MUC15 is highly expressed in the placenta. This study aimed to characterise MUC15 in preeclampsia and investigate its role in placental stem cell biology. MUC15 mRNA and protein were measured in placentas from patients with early onset (<34 weeks' gestation) preeclampsia. Circulating serum MUC15 was measured via ELISA. MUC15 was localised in the placenta using in situ hybridisation. MUC1 5 mRNA expression was measured across differentiation of human trophoblast stem cells (hTSCs) to syncytiotrophoblast and extravillous trophoblasts. MUC15 was measured after syncytialised hTSCs were cultured in hypoxic (1% O 2) and proinflammatory (TNF α , IL-6) conditions. MUC15 secretion was assessed when syncytialised hTSCs were treated with brefeldin A (impairs protein trafficking) and batimastat (inhibits matrix metalloproteinases). MUC15 protein was significantly increased in the placenta (P = 0.0003, n = 32 vs n = 20 controls) and serum (P = 0.016, n = 32 vs n = 22 controls) of patients with preeclampsia, whilst MUC1 5 mRNA remained unchanged (n = 61 vs n = 18 controls). MUC1 5 mRNA (P = 0.005) and protein secretion (P = 0.006) increased following differentiation to syncytiotrophoblast cells. In situ hybridisation confirmed MUC15 localised to the syncytiotrophoblast cell within the placenta. Neither hypoxic or inflammatory conditions changed MUC1 5 mRNA expression or secretion. Brefeldin A treated hTSCs did not alter MUC15 secretion, whilst batimastat reduced MUC15 secretion (P = 0.044). MUC15 is increased in early onset preeclampsia and is cleaved by matrix metalloproteinases. Increased MUC15 may reflect a protective mechanism associated with placental dysfunction. Further research will aid in confirming this. • MUC15 was increased in the placenta and circulation of patients with preeclampsia. • MUC15 was localised to the syncytiotrophoblast cell layer of the placenta. • Matrix metalloproteinases may be involved in the cleavage of MUC15. [ABSTRACT FROM AUTHOR]

Development of a therapeutic that targets the pathophysiological elements of preeclampsia would be a major advance for obstetrics, with potential to save the lives of countless mothers and babies. We recently identified anti-inflammatory drug sulfasalazine as a prospective candidate therapeutic for treatment of preeclampsia. In primary human cells and tissues in vitro , sulfasalazine potently decreased secretion of anti-angiogenic sFlt-1 and sENG, increased production of pro-angiogenic PlGF, mitigated endothelial dysfunction, and promoted whole vessel vasodilation. Using nitric oxide synthase antagonist Nω-Nitro- l -arginine methyl ester hydrochloride, a preeclampsia-like phenotype was induced in pregnant mice, including high blood pressure, fetal growth restriction, and elevated circulating sFlt-1. Mice were treated with sulfasalazine or vehicle from gestational day (D)13.5, with blood pressure measurements across gestation, fetal measurements at D17.5, and wire myograph assessment of vasoactivity. Sulfasalazine had a modest effect on blood pressure, decreasing diastolic and mean blood pressure on D13.5, but not later in gestation, or systolic blood pressure. Sulfasalazine was not able to rescue fetal growth, in male or female fetuses. There was a suggestion of improved vasoactivity with sulfasalazine, but further clarification is required. In this mouse model of preeclampsia, sulfasalazine did not sustain reductions in blood pressure nor affect fetal parameters of size and weight, both desirable attributes of a viable preeclampsia therapeutic. While these data suggest sulfasalazine might improve vasoactivity, murine toxicity considerations limited the dose range of sulfasalazine that could be tested in the current study. • Sulfasalazine modestly decreases blood pressure in a mouse model of preeclampsia. • Sulfasalazine was unable to rescue fetal growth restriction. • Sulfasalazine may improve vasoactivity. [ABSTRACT FROM AUTHOR]

Background: Dishevelled Associated Activator Of Morphogenesis 2 (DAAM2) levels are elevated in the maternal circulation and placenta in pregnancies complicated by fetal growth restriction. However, placental DAAM2 levels in cases of preeclampsia have not previously been explored. Here, we examined placental DAAM2 in pregnancies complicated by preterm preeclampsia, and whether candidate preeclampsia therapeutics altered its expression.Methods: DAAM2 mRNA and protein levels were assessed in placental tissue from cases of preterm preeclampsia and gestation-matched controls (delivering ≤ 34 weeks; qPCR and western blot respectively). Short interfering RNAs were used to silence DAAM2 in isolated primary cytotrophoblast under normoxic (8 % O2) and hypoxic (1 % O2) conditions, and expression of anti-angiogenic sFLT-1, angiogenic PGF, antioxidant, fetal growth, and inflammatory genes assessed. DAAM2 expression was measured in placental explant tissue from pregnancies complicated by preeclampsia, treated with three proton pump inhibitors (100 µM esomeprazole, lansoprazole, and rabeprazole).Results: DAAM2 expression was significantly reduced in preeclamptic placental tissue compared to controls, but protein production was unchanged. Silencing DAAM2 in hypoxic cytotrophoblast increased sFLT-i13 isoform expression, but did not alter sFLT-e15a or PGF expression, or sFLT-1 secretion. DAAM2 knockdown did not alter expression of antioxidant (NQO-1, TXN, GCLC), fetal growth (SPINT1), or inflammasome (NLRP3) genes. Esomeprazole and lansoprazole, but not rabeprazole, increased DAAM2 expression in placental explant tissue from cases of preeclampsia.Conclusion: Placental DAAM2 protein is not significantly altered in placental tissue in cases of preeclampsia, and its suppression does not alter sFLT-1 secretion. Hence, placental DAAM2 is unlikely to drive the pathogenesis associated with preeclampsia. [ABSTRACT FROM AUTHOR]

Metformin, widely used to treat diabetes, is now considered a candidate therapeutic for treatment of cardiovascular disease. This study aimed to assess whether metformin's non-glycaemic effects could mitigate cardiovascular disease indices in female mice consuming a high fat diet (HFD). Four-week old female Arc:Arc(S) mice were placed on a standard (std) chow diet or Western-style HFD (22% fat, 0.15% cholesterol). At ∼8 months, the mice were administered 150 mg/kg metformin or vehicle (control) via intraperitoneal injection for 11 days. Blood pressure was measured (tail cuff plethysmography) at Day 9 and 11 of treatment. On Day 11, mice were weighed and culled. The mesenteric arcade and kidneys were collected for assessment of vascular reactivity (wire myography), and assessment of expression of cardiometabolic markers (qPCR), respectively. The HFD fed female mice were significantly heavier than those receiving the std diet at 1–12 weeks on diet, and at cull. Mice on a std diet with metformin treatment were significantly heavier at cull than the mice on a std diet administered the control treatment. Metformin treatment did not alter the weight of the mice receiving the HFD. Neither the HFD (compared to the std diet), nor metformin treatment (compared to control treatment) altered blood pressure, vascular reactivity, or expression of cardiometabolic markers in the kidney. Consumption of a Western-style HFD (without high salt/sugar levels) did not alter the cardiovascular markers measured. Further studies are required to establish the non-glycaemic, cardio-protective effects of metformin in high-risk cohorts. • A high fat diet causes significant, sustained increase in female mouse body weight. • Exposure to metformin did not alter body weight of female mice on a high fat diet. • Sustained high fat diet in female mice did not alter measured cardiovascular indices. • Metformin did not alter measured cardiovascular indices in female mice. [ABSTRACT FROM AUTHOR]

Activin A is aberrantly expressed by the preeclamptic placenta and circulating levels have been investigated as a potential biomarker for the disease. In a nested case-control study we measured Activin A levels in maternal plasma at 28- and 36-weeks' gestation preceding term preeclampsia diagnosis. At 28 weeks Activin A was not significantly altered (n = 73 destined to develop preeclampsia vs n = 191 controls). At 36 weeks' gestation Activin A was significantly increased in 40 women destined to develop preeclampsia relative to 201 controls (p < 0.0001). These findings provide further validation of Activin A as a potential biomarker for subsequent term preeclampsia. [ABSTRACT FROM AUTHOR]

There has been increasing research momentum to identify new therapeutic agents for the prevention or treatment of preeclampsia, drugs that can affect the underlying disease pathophysiology. Molecular targets of candidate treatments include oxidative stress, antiangiogenic factors, and the angiotensin, nitric oxide, and proinflammatory pathways. The proposed treatments undergoing preclinical and clinical trial evaluation are thought to act on placental or endothelial disease or both. Most have adopted the pragmatic strategy of repurposing drugs. Of all the therapeutic agents proposed, pravastatin has received the most interest. There are preclinical studies showing that it has pleiotropic actions that favorably impact on multiple molecular targets and can resolve a preeclampsia phenotype in many animal models. An early phase clinical trial suggests that it may have therapeutic activity. Several large prevention trials are planned or ongoing and, when completed, could definitively address whether pravastatin can prevent preeclampsia. Proton-pump inhibitors, metformin, and sulfasalazine are other drugs with preclinical evidence of multiple molecular actions that could resolve the pathophysiology of preeclampsia. These agents are also currently being evaluated in clinical trials. There have been many recent preclinical studies identifying the potential of numerous natural compounds to treat preeclampsia, such as plant extracts and micronutrients that have potent anti-inflammatory or antioxidant activity. Recent preclinical studies have also proposed novel molecular-targeted strategies, such as monoclonal antibodies targeting tumor necrosis factor alpha, placental growth factor, and short interfering RNA technology, to silence the gene expression of soluble fms-like tyrosine kinase-1 or angiotensinogen. Other treatment approaches that have transitioned to human trials (ranging from single-arm to phase III trials that have been completed or are ongoing) include folic acid, nitric oxide donors (such as L-arginine), recombinant antithrombin III, digoxin immune antigen-binding fragment, and melatonin. There have been case series showing the removal of circulating soluble fms-like tyrosine kinase-1 may help stabilize the disease and prolong pregnancy. Interestingly, there are case reports suggesting that monoclonal antibody eculizumab (complement inhibitor) may have therapeutic potential. If new agents are discovered that are proven to be effective in preventing or treating preeclampsia, the potential to improve global maternal and perinatal health will be significant. [ABSTRACT FROM AUTHOR]

First trimester circulating ADAM12 is reduced in fetal growth restriction (FGR) and preeclampsia. We measured plasma ADAM12 at 36 weeks' gestation preceding diagnosis of term preeclampsia or delivery of a small for gestational age (SGA; birthweight <10th centile) infant in two independent cohorts (Cohort 1 90 SGA, 41 preeclampsia, 862 controls; Cohort 2121 SGA 23 preeclampsia; 190 controls). ADAM12 was reduced with SGA in both cohorts (p = 0.0015 and 0.011 respectively), and further reduced with birthweight <5th centile (p = 0.0013 and 0.0058 respectively). This validates ADAM12 as an SGA biomarker near term. Circulating ADAM12 preceding preeclampsia was not consistently altered. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia is associated with reduced pro-angiogenic Placental Growth Factor (PlGF) and increased levels of anti-angiogenic soluble FMS like tyrosine kinase-1 (sFlt-1). We have previously shown that sFlt-1 secretion is positively regulated via the Epidermal Growth Factor Receptor (EGFR) and mitochondrial respiration pathways. We assessed whether these pathways also regulate endothelial and placental secretion of PlGF.Methods: Primary cytotrophoblast cells and primary human umbilical vein endothelial cells (HUVECs) were treated with EGFR inhibitor gefitinib, or small molecules that inhibit down-stream pathways of the receptor: U0126, PD98059 (ERK/MEK pathway inhibitors), ZM336372 (JAK/STAT inhibitor) or AG490 (JAK inhibitor). We inhibited mitochondrial respiration in primary cytotrophoblasts using mitochondrial complex inhibitors rotenone (complex I), antimycin (complex III) or oligomycin (complex IV). We then measured PlGF secretion in the condition media.Results: Three inhibitors of the EGFR pathway significantly increased PlGF secretion: gefitinib (p = 0.03), AG490 (p < 0.0001) and U0126 (p = 0.03) in primary cytotrophoblasts, while PD98059 reduced PlGF secretion (p = 0.002). In the same cells, neither gefitinib or UO126 altered PlGF mRNA expression, but AG490 significantly increased its expression (p = 0.02). Primary endothelial cell PlGF secretion was significantly reduced when treated with PD98059 and U0126 while ZM336372 had no effect. Rotenone significantly reduced cytotrophoblast PlGF secretion (p = 0.0005). Neither antimycin (p = 0.9) or oligomycin (p = 0.9) had an effect.Discussion: We have shown that PlGF secretion from primary cytotrophoblast and HUVECs is altered by inhibiting EGFR signaling and potentially mitochondrial respiration, coincident with reduced sFlt-1 secretion. This suggests that common pathways are regulating both pro and anti-angiogenic molecules that are changed in association with preeclampsia and provides insight into the pathogenesis of this serious disease. [ABSTRACT FROM AUTHOR]

Introduction: The human placenta has a defined lifespan and placental aging is a key feature as pregnancy progresses. Placental aging and mitochondrial dysfunction are known to play a key role in pregnancy pathophysiology. Premature aging of the placenta has also been linked with placental dysfunction resulting in poor fetal development and premature birth.Methods: The expression of key mitochondrial-related genes were analysed in a series of publicly available databases then expression changes were validated in placental samples collected from term, pre-term, post-term pregnancies and pregnancies complicated by fetal growth restriction (FGR). Gene and protein expression levels of MFN1, MFN2, TFAM, TOMM20, OPA3 and SIRT4 were measured in placental tissues via qPCR and western blotting.Results: Initial analysis found that key mitochondrial transcripts related to biogenesis, bioenergetics and mitophagy clustered by pregnancy trimester. A refined list of 13 mitochondrial-related genes were investigated in additional external datasets of pregnancy complications. In the new cohort, protein expression of MFN1 was decreased in FGR and MFN2 is decreased in post-term placenta. Analysis of placental tissues revealed that TOMM20 gene and protein expression was altered in FGR and post-term placenta.Discussion: MFN1 and MFN2 play a major role in mitochondrial dynamics, and alterations in these markers have been highlighted in early unexplained miscarriage. TOMM20 is an importer protein that plays a major role in mitophagy and changes have also been identified in age-related diseases. Significant changes in MFN1, MFN2 and TOMM20 indicate that mitochondrial regulators play a critical role in placental aging and placental pathophysiology. [ABSTRACT FROM AUTHOR]

Objectives: The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is upregulated in the maternal vasculature in preeclampsia, and contributes to oxidative stress and endothelial dysfunction. However, its function in the placenta is unclear. This paper investigated LOX-1 expression in models of placental dysfunction and preeclampsia, and whether candidate therapeutics for preeclampsia could alter its expression.Study Design: Placentas were collected from preterm pregnancies and cases of preterm preeclampsia and fetal growth restriction. Blood was collected from participants whose pregnancies were complicated by preterm fetal growth restriction and/or preeclampsia. Primary cytotrophoblast and placental explant tissue were cultured under hypoxic (1% O2) or normoxic (8% O2) conditions. Cytotrophoblast were exposed to 10% preeclamptic or control serum. Cytotrophoblast and preeclamptic explant tissue were treated with 100 µM esomeprazole, lansoprazole or rabeprazole.Main Outcome Measures: LOX-1 expression was assessed in all samples via qPCR.Results: LOX-1 expression was reduced in placentas from cases of preterm preeclampsia, but not fetal growth restriction, compared to controls. LOX-1 expression was reduced in cytotrophoblast under hypoxia, but not in explant tissue. Treatment with preeclamptic serum in vitro did not alter cytotrophoblast LOX-1 expression. Circulating LOX-1 mRNA was unaltered in patients with fetal growth restriction, preeclampsia, and fetal hypoxia, compared to controls. Treatment with esomeprazole or lansoprazole in vitro increased placental LOX-1 expression.Conclusions: LOX-1 expression is reduced in preeclamptic placentas and hypoxic cytotrophoblast. Esomeprazole and lansoprazole increase placental LOX-1 expression. These findings demonstrate a role for LOX-1 in the placenta, and improve our understanding of maternal adaptations in pregnancy complications. [ABSTRACT FROM AUTHOR]

Fetal growth restriction arising from placental insufficiency is a leading cause of stillbirth. We recently identified low maternal circulating SPINT1 concentrations as a novel biomarker of poor fetal growth. Here we measured SPINT1 in a prospective cohort in Singapore. Circulating SPINT1 concentrations were significantly lower among 141 pregnant women destined to deliver small-for-gestational age infants (birthweight <10th centile), compared to 772 controls (p < 0.01) at as early as 26 weeks' gestation. There were no correlations between infant body composition and circulating SPINT1 concentrations at 26 weeks. This provides validation that low maternal SPINT1 concentration is associated with poor fetal growth. [ABSTRACT FROM AUTHOR]

Introduction: Tissue Factor Pathway Inhibitor (TFPI) is a part of the extrinsic coagulation pathway, and highly expressed in the placenta. We aimed to assess its potential as a preeclampsia biomarker.Methods: Maternal plasma was prospectively collected at 36 weeks' gestation. Circulating TFPI was measured in a nested case-control group (39 women who developed preeclampsia, 98 controls), before being measured in a larger independent cohort along with Placental Growth Factor (PlGF; 41 who developed preeclampsia, 954 controls). Circulating TFPI was then measured in women with underlying vascular disease, and also assessed in the plasma and placentas from women with preterm preeclampsia (delivered at <34 weeks).Results: Circulating TFPI was significantly increased in women destined to develop preeclampsia in the case-control study, a finding that validated in Cohort 2, with median TFPI in the preeclampsia group being 42.3 ng/ml (IQR 30-51 ng/ml) compared to 30 ng/ml (IQR 23.1-38.6 ng/ml) in controls (p < 0.0001). The area under the receiver operator characteristic curve (AUC) was 0.70. PlGF was significantly reduced in the preeclampsia group, and a ratio of TFPI/PlGF had an improved AUC of 0.78. In women with underlying vascular disease who were later diagnosed with early onset preeclampsia, circulating TFPI was significantly increased with a 0.29 (95% CI 0.13-0.44) increase in logTFPI (adjusted for gestation and hypertensive status). Circulating and placental TFPI were significantly increased in women with preterm preeclampsia.Discussion: Circulating TFPI is increased in women preceding diagnosis of preeclampsia (at 36 weeks) and in women with preterm disease. TFPI may beneficially contribute to a multi-marker blood test to predict preeclampsia. [ABSTRACT FROM AUTHOR]

Preeclampsia is a complex disease affecting 2-8% of pregnancies worldwide. It poses significant risk of maternal and perinatal morbidity and mortality. Despite the rising research interest to discover new therapeutic approaches to prevent and treat preeclampsia, options remain limited. Identifying the important pathological stages in the progression of this disease allows us to evaluate effective candidate therapeutics. Three important stages in the pathophysiology are: 1) placental hypoxia and oxidative stress, 2) excess release of anti-angiogenic and pro-inflammatory factors, and 3) widespread systemic endothelial dysfunction and vasoconstriction. Repurposing drugs already safe for use in pregnancy is an attractive option for discovery of novel therapeutics. There are many drugs currently being assessed to treat preeclampsia, including proton pump inhibitors (PPIs), metformin, statins, sulfasalazine, sofalcone, resveratrol, melatonin, and sildenafil citrate. These drugs show positive effects in preclinical studies, targeting placental and endothelial dysfunction. However, using novel therapeutics can raise safety concerns for the developing fetus. Therefore, innovative targeted delivery systems are being developed to safely administer these therapeutics directly to the placenta and/or endothelium. These include nanoparticle delivery systems, developed and used by the oncology field, now being adapted for obstetrics. This technology is currently being assessed in animal models and shows promise for treating preeclampsia. Combining effective therapeutics with targeted drug delivery could be the future of preeclampsia treatment. [ABSTRACT FROM AUTHOR]

Development and repurposing of therapies that show promise in the prevention or treatment of preeclampsia would be a major advance for the obstetrics field. We recently identified esomeprazole and sulfasalazine as potential candidates for the treatment of preeclampsia. Both reduce placental and endothelial secretion of sFlt-1 and sENG and mitigate endothelial dysfunction in vitro. Here we assessed whether esomeprazole and sulfasalazine in combination would additively attenuate the elevated release of anti-angiogenic factors and markers of endothelial dysfunction, key characteristics of preeclampsia. Primary placental tissue and cells, and primary endothelial cells were treated with esomeprazole and sulfasalazine alone and in combination. We assessed secretion of sFlt-1 and sENG and performed in vitro assays of endothelial dysfunction. Combining esomeprazole and sulfasalazine in lower concentrations caused an additive reduction in sFlt-1 secretion in primary cytotrophoblasts, placental explants and endothelial cells. No additive reduction was observed in sENG secretion when esomeprazole and sulfasalazine were combined. Together, esomeprazole and sulfasalazine additively reduced TNF-α-induced VCAM and ET-1 mRNA expression, and monocyte adhesion to endothelial cells. In conclusion, combining esomeprazole and sulfasalazine additively reduced secretion of sFlt-1 and markers of endothelial dysfunction. Combined administration of esomeprazole and sulfasalazine may provide a more effective treatment or prevention for preeclampsia compared to either as single agents. [ABSTRACT FROM AUTHOR]

Introduction: Oxidative damage and biochemical ageing are implicated in placental dysfunction and potentially fetal death. Cellular senescence may play a role in the pathophysiology of fetal growth restriction (FGR) and preeclampsia (PE). Aurora kinases (AURKA, B and C) are important regulators of cellular division in mitosis and meiosis with implications in cellular senescence. We aimed to investigate whether aurora kinase expression is altered with placental dysfunction or placental ageing.Methods: Placenta and blood was obtained across gestation from pregnancies complicated by PE, FGR or both PE and FGR, as well as gestation-matched control samples. Expression of AURKA, B and C mRNA was examined using real time qPCR in both the placenta and maternal circulation.Results: Placental aurora kinase expression decreased as gestation progressed: AURKA and AURKB were significantly reduced at 37-40 weeks, whereas AURKC was significantly reduced at 34-37 weeks, when compared to <34 weeks. In the maternal circulation, the mRNA level of AURKB was significantly reduced at >40 weeks compared to <34 weeks gestation. A significant reduction in AURKC was seen in FGR pregnancies <34 weeks compared to gestation-matched controls.Conclusion: Placental AURK expression is reduced with increased gestation. Circulating AURKB mRNA reduces at >40 weeks gestation, when compared to <34 weeks. AURKC is significantly reduced in placentas from pregnancies complicated by severe early onset (<34 weeks) FGR compared with gestation-matched controls. The functional role of aurora kinase in the placenta and in gestational age warrants further investigation. [ABSTRACT FROM AUTHOR]

Introduction: The antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sENG) are elevated in preeclampsia and have been implicated in its pathogenesis. We have previously demonstrated metformin and sulfasalazine independently reduce antiangiogenic factor secretion. Here we examined whether combining metformin and sulfasalazine may be more effective than either alone in reducing placental expression and secretion of antiangiogenic and angiogenic factors and the expression of markers of endothelial dysfunction.Methods: We performed functional experiments using primary human placenta to explore the effect of metformin and sulfasalazine, at lower doses than previously explored, individually and in combination, on sFlt-1 and sENG secretion and placental growth factor (PlGF) and vascular endothelial growth factor (VEGFα) expression. Using primary endothelial cells we induced dysfunction using cytokine tumor necrosis factor-α (TNF-α) and assessed the effect of low dose combination treatment on the expression of vascular cell adhesion molecule-1 (VCAM-1) and Endothelin-1 (a potent vasoconstrictor).Results: We demonstrated combination metformin and sulfasalazine was additive in reducing sFlt-1 secretion from cytotrophoblasts and placental explants. Combination treatment was also additive in reducing sENG secretion from placental explants. Furthermore, combination treatment increased cytotrophoblast VEGFα mRNA expression. Whilst combination treatment increased PlGF mRNA expression this was similar to treatment with sulfasalazine alone. Combination therapy reduced TNFα induced endothelin-1 mRNA expression however did not change VCAM expression.Discussion: Low dose combination metformin and sulfasalazine reduced cytotrophoblast sFlt-1 and sENG secretion, increased VEGFα expression and reduced TNFα induced endothelin-1 expression in primary endothelial cells. Combination therapy has potential to treat preeclampsia. [ABSTRACT FROM AUTHOR]

Objectives: There is avid interest in pravastatin as a therapeutic intervention for pre-eclampsia, however little is known on statin action on endothelial dysfunction. This study aimed to evaluate the ability of pravastatin, simvastatin and rosuvastatin to reduce pre-eclampsia-associated markers of endothelial dysfunction in human endothelial cells.Study Design: Primary human umbilical vein endothelial cells (HUVECs) and uterine microvascular cells (UtMVs) were isolated and treated with 0.2, 2, 20 and 200 µM pravastatin, simvastatin and rosuvastatin for 24 h, either with or without pre-treatment with TNF-α to induce endothelial dysfunction.Main Outcome Measures: Cell viability (MTS) assays were performed and cells were visually inspected. Expression of endothelial dysfunction markers, endothelin-1 (ET-1) and vascular cell adhesion molecule-1 (VCAM-1) were assessed by qPCR (n=3). Intracellular VCAM-1 protein was examined by Western Blotting (n=5). ET-1 and soluble fms-like tyrosine kinase-1 (sFLT-1) protein secretion was assessed by ELISA in HUVEC conditioned media (n=3).Results: High doses of simvastatin and rosuvastatin significantly compromised HUVEC survival. 200 µM simvastatin significantly reduced UtMV survival. Abnormal cell structure was observed with these doses and thus were excluded from further analysis. The statins did not mitigate TNF-α induced ET-1 or VCAM-1 expression in either HUVECs or UtMVs, nor VCAM-1 protein expression in HUVECs. 0.2 µM pravastatin and simvastatin significantly reduced ET-1 and sFLT-1 protein secretion.Conclusions: Pravastatin significantly reduced secretion of both ET-1 and sFLT-1, key mediators of endothelial dysfunction. Importantly, pravastatin had no toxic effects, in contrast to rosuvastatin and simvastatin. This further supports selection of pravastatin for clinical applications to combat pre-eclampsia. [ABSTRACT FROM AUTHOR]

Introduction: Recently, Delta-like homolog 1 (DLK1) was identified as a potential marker of small-for-gestational-age (SGA; <10th centile) fetuses; mouse studies suggest reduced levels may represent a fetal stress signal. We sought to measure DLK1 in a large independent cohort of maternal blood samples, correlate levels with measures of placental insufficiency and assess whether DLK1 might be placental derived.Methods: The Fetal Longitudinal Assessment of Growth (FLAG) study was a prospective blood collection from 2000 women. We assessed a case-control cohort at 28 and 36 weeks from the first 1000 FLAG women, before validating changes in the entire second 1000. A subgroup of FLAG participants underwent ultrasound examinations, and 137 neonates, body composition assessment (PEAPOD). DLK1 secretion was assessed from human placentas ex vivo.Results: Circulating DLK1 was significantly reduced at 28 and 36 weeks' gestation in women destined to deliver a SGA fetus and associated with birthweight centile (n = 999, p < 0.0001), and placental weight (n = 96, p = 0.0064). Ex vivo, DLK1 was abundantly released from human placenta and significantly reduced under hypoxia (n = 7, p < 0.05). We found no relationship between circulating DLK1 and estimated fetal weight, cerebroplacental ratio, uterine artery or umbilical artery pulsatility index. Nor was there a relationship between DLK1 and neonatal fat or lean mass (n = 137).Conclusion: We confirmed circulating DLK1 is reduced at both 28 and 36 weeks' gestation preceding delivery of a SGA infant, shown that it is not significantly associated with clinical measures of placental insufficiency, and provide new data demonstrating it may be placenta-derived in humans. [ABSTRACT FROM AUTHOR]

Introduction: Death associated protein kinase-1 (DAPK-1) is highly expressed in the placenta relative to all other human tissues. We examine whether it is differentially expressed with preeclampsia.Methods: We examined samples from a large prospective collection of plasma from 2002 women. We split the samples into two cohorts: Cohort 1 (n = 1000) and Cohort 2 (n = 1002). We first measured circulating DAPK-1 at 36 weeks' gestation in a nested case-control group (from Cohort 1) of 39 women who developed preeclampsia and 98 controls. We then validated our findings by measuring circulating levels in all samples from both cohorts. We also measured DAPK-1 in the circulation and placentas of women who were diagnosed with preterm preeclampsia or delivered a growth restricted infant at <34 weeks' gestation.Results: In the case-control study, circulating DAPK-1 was significantly increased in women destined to develop preeclampsia (p < 0.01). We validated this by measuring circulating levels in Cohorts 1 and 2. Again, circulating DAPK-1 was significantly higher (p < 0.001) among women destined to develop preeclampsia (Cohort 1, Area under the receiver operator characteristic curve (AUC) = 0.66; Cohort 2 AUC = 0.67). Circulating DAPK-1 was also significantly elevated in women with established preterm preeclampsia. Placental DAPK-1 mRNA and protein expression were elevated in women with established preeclampsia.Discussion: DAPK-1 is a novel placenta-enriched molecule that is elevated in the circulation of women preceding the diagnosis of preeclampsia and is likely to be secreted from the placenta. [ABSTRACT FROM AUTHOR]

Objectives: Preeclampsia is a hypertensive disorder of pregnancy with no available medical treatment. We recently reported sulfasalazine, an anti-inflammatory medication, to be a candidate therapeutic for preeclampsia. We showed sulfasalazine decreases placental secretion of soluble Fms-like tyrosine kinase-1 (sFlt-1), an anti-angiogenic factor strongly implicated in the pathogenesis of preeclampsia. However, the cellular mechanism(s) by which sulfasalazine reduces placental sFlt-1 are yet to be determined. Recently we also reported that both the mitochondria and the epidermal growth factor receptor (EGFR) signalling pathways regulate secretion of placental sFlt-1. In this study we sought to assess directly whether sulfasalazine's capacity to reduce sFlt-1 secretion may be mediated via EGFR or the mitochondria.Methods and Results: Using primary cytotrophoblast cells, we confirmed sulfasalazine reduced sFlt-1 secretion. Interestingly, when we measured the mRNA expression of EGFR, we found a reduction in EGFR expression which closely mirrored the changes in sFlt-1 secretion. At the protein level, sulfasalazine significantly reduced phosphorylated and active EGFR (phosphorylated/total) expression. Additionally, sulfasalazine significantly reduced the protein expression of ERK1/2 and STAT3 which are key adaptor molecules downstream of EGFR. Next, we assessed mitochondrial respiration following sulfasalazine treatment and found no effect on basal respiration, ATP production, proton leak or maximal respiration.Conclusion: Sulfasalazine reduces EGFR and down-stream signalling molecule expression coincident with reduced sFlt-1 secretion. EGFR signalling is a potential mechanism by which sulfasalazine decreases placental secretion of sFlt-1. Further interrogation of the EGFR may identify new candidate treatments for preeclampsia. [ABSTRACT FROM AUTHOR]

Soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sENG) are increased in the circulation of women with preeclampsia. We examined whether they differ in concentration between plasma and serum samples. Maternal blood was collected and processed for serum and plasma, from 28 women with preterm preeclampsia and 18 gestation matched controls (<34weeks). Significantly higher sFlt-1 was detected in preeclamptic serum compared to plasma. Significantly higher levels of sENG were identified in serum compared to plasma from control pregnancies. Thus these data show the sample type (serum or plasma) needs to be consistent within comparisons for both sFlt-1 and sENG. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia (PE) and fetal growth restriction (FGR) are among the leading causes of perinatal morbidity and mortality. Placental insufficiency is central to these conditions. The mechanisms underlying placental insufficiency are poorly understood. Apoptosis has long been considered the only form of regulated cell death, recent research has identified an alternate process of programmed cell death known as necroptosis [1]. Necroptosis is distinct from apoptosis, relying on the deacetylase sirtuin-2 [2], receptor interacting kinases RIPK1 and 3, and the pseudokinase MLKL [3]. We aimed to determine whether these key necroptosis effector molecules were present in human placenta and whether they are differentially expressed in severe preterm (PT) PE and FGR.Methods: PT placentas from severe early onset (<34 weeks) PE (n = 30), FGR (n = 12) and control (18) pregnancies were collected. SIRT2 and RIPK1 localization and quantitation was determined by immunohistochemistry and western blot. Immunocytochemistry was used to detect SIRT2 and RIPK1 in trophoblastic debris from first trimester, term control and PE pregnancies. Expression of SIRT2, RIPK1, RIPK3 and MLKL was examined by qPCR.Results: SIRT2 and RIPK1 were localized to the syncytiotrophoblast, villous leukocytes and vasculature in all PT placentas. A significant reduction in SIRT2 protein expression in both PE and FGR placentas was identified. RIPK1 mRNA expression was significantly increased in PE placentas. Immunofluorescence identified both SIRT2 and RIPK1 in the cytotrophoblast cytoplasm.Discussion: We have identified the presence of activators of necroptosis in human placenta. Interestingly, there is differential expression in major pregnancy complications. We conclude necroptosis may contribute to placental pathophysiology that underlies serious pregnancy complications. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia is a serious complication of pregnancy affecting 5% of pregnancies. Our team identified 137 genes highly expressed in placenta relative to other human tissues. Here, we have explored a role for steroid sulfatase (STS) in preeclampsia by characterising STS expression and the functional effects of STS on primary placental trophoblasts.Methods: Characterisation of STS was performed on preterm preeclamptic and gestation-matched normotensive preterm controls who delivered at <34 weeks gestation. We characterised placental and maternal whole blood STS mRNA and placental protein expression via qRT-PCR, immunohistochemistry and Western Blot. To assess whether STS is involved in sFlt1 secretion and syncytialisation, we administered siRNA to silence STS in primary trophoblasts before measuring sFlt1 and hCG secretion and E-Cadherin expression.Results: A custom array containing 45 placental specific genes identified 10 genes significantly altered in the placentas of preeclamptic patients relative to normotensive gestation-matched controls. Of these genes, qRT-PCR and western blot on a larger cohort confirmed that the expression of STS was significantly elevated in preeclamptic placentas (n = 44) relative to gestation matched controls (n = 26). Given placental RNA leaks in to the maternal circulation, we also assessed STS mRNA expression in the whole blood of patients with preeclampsia and found it was significantly increased relative to normotensive controls. siRNA knockdown of STS in primary trophoblast resulted in a modest but significant reduction in sFlt1 secretion, but had no affect on hCG secretion or E-Cadherin protein expression.Discussion: STS is increased in preeclamptic placentas and maternal whole blood. Our data suggests that STS may affect sFlt1 secretion by regulating sFlt1-i13 transcription, and not via alterations in syncytialisation. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia is a serious complication affecting 5-8% of pregnancies. Central to its pathogenesis is placental hypoxia and inflammation which leads to secretion of soluble fms-like tyrosine kinase 1 (sFlt-1). sFlt-1 causes widespread endothelial dysfunction. The molecular mechanisms regulating sFlt-1 production remain poorly understood. Recently, a binding site for the nuclear factor activated T cells (NFAT) transcription factor has been found on fms-like tyrosine kinase 1 (FLT-1) promoter.Methods: We assessed whether inhibiting NFAT impacts FLT-1, sFlt-1 and cytokine expression, as well as sFlt-1 secretion in primary cytotrophoblasts, placental explants and human umbilical vein endothelial cells (HUVECs). We investigated whether NFAT is regulated by hypoxia in primary cytotrophoblasts. We characterised the expression of NFAT1-4 in preterm preeclamptic compared to gestationally matched placentas.Results: Inhibiting NFAT reduced FLT-1 and sFlt-1 splice variant e15a transcription, concordant with reduced total sFlt-1 and sFlt-1 e15a secretion from primary human cytotrophoblasts. This effect appeared tissue specific as inhibiting NFAT did not change sFlt-1 secretion from endothelial cells. Inhibiting NFAT also reduced transcription of inflammatory cytokines IL-1β and IL-10 in primary cytotrophoblasts. NFAT1 and NFAT3 mRNA expression were significantly increased under hypoxia (1% O2). Inhibiting NFAT under hypoxia significantly reduced FLT-1 and sFlt-1 e15a transcription, but did not reduce sFlt-1 secretion. NFAT mRNA and protein localisation was not different in preeclamptic compared to gestationally matched placenta.Discussion: NFAT positively regulates placental FLT-1 and sFlt-1 e15a, secretion of sFlt-1 and inflammatory cytokine expression. It may be involved in the pathophysiology of preeclampsia. [ABSTRACT FROM AUTHOR]

Introduction: Infection and inflammation stimulate pro-inflammatory cytokines, prostaglandins and matrix metalloproteinase (MMP)-9, which play a central role in myometrial contractions and rupture of fetal membranes. In human and mouse immune cells, activating transcription factor 3 (ATF3) is a negative regulator of inflammation. No studies have examined the role of ATF3 in human labour.Methods: Primary amnion cells were used to determine the effect of interleukin (IL)-1β and the bacterial product fibroblast-stimulating lipopeptide (fsl-1) on ATF3 expression, and the effect of ATF3 siRNA on pro-labour mediators. ATF3 expression was assessed in fetal membranes from non-labouring and labouring women at term and preterm, and after preterm pre-labour rupture of membranes (PPROM).Results: IL-1β and fsl-1 significantly increased ATF3 expression. Silencing ATF3 significantly increased IL-1β- or fsl-1-induced expression of pro-inflammatory cytokines (TNF-α, IL-1α, IL-1β, IL-6) and chemokines (IL-8 and monocyte chemoattractant protein-1 (MCP-1)); cyclooxygenase-2 (COX-2) mRNA expression and prostaglandin PGF2α release; and MMP-9 expression. ATF3 expression was decreased in fetal membranes with term labour. There was no effect of preterm labour or PPROM on ATF3 expression.Discussion: ATF3 is a negative regulator of inflammation in human fetal membranes; in primary amnion cells, ATF3 expression is induced by IL-1β and fsl-1, and ATF3 silencing further exacerbates the inflammatory response when stimulated with these factors. Subsequently, ATF3 expression is decreased in fetal membranes after term labour and with preterm chorioamnionitis, conditions closely associated with inflammation and infection. Our data suggest that ATF3 may play a role in the terminal processes of human labour and delivery. [ABSTRACT FROM AUTHOR]

Pregnancy complications such as fetal growth restriction and preeclampsia are diseases with limited biomarkers for prediction, and a complete lack of therapeutic options. We define placenta-enriched molecules as those that are highly expressed in the placenta relative to all other human tissues. Many exist including mRNAs, miRNAs and proteins. It is now well established that placenta-enriched mRNAs are found within the maternal circulation and are cleared rapidly after birth. Similarly, distinct clusters of miRNAs that are placenta-enriched have been identified and are measurable within the circulation. However, perhaps the most established potential diagnostics thus far are circulating placental proteins such as placental growth factor (PlGF), pregnancy associated pregnancy protein-A (PAPP-A) and soluble FMS-like tyrosine kinase 1 (sFlt-1). There has also been much interest in targeting placenta-enriched molecules as a means to treat diseases of pregnancy. We have shown promising results in targeting placenta-enriched epidermal growth factor receptor (EGFR) to treat ectopic pregnancy. Others have focused on using placenta-enriched molecules as a means of homing therapeutic-filled nanoparticles to the placenta, or to directly target sFlt-1 to improve disease outcomes. Importantly, many placenta-enriched molecules remain largely unstudied. We propose that a better understanding of their biology, and potential contribution to the pathogenesis of diseases, may yield more predictive diagnostic and therapeutic targets. [ABSTRACT FROM AUTHOR]

Preeclampsia is a pregnancy complication associated with elevated placental secretion of anti-angiogenic factors, maternal endothelial dysfunction and end-organ injury. Adrenomedullin (ADM) is a pro-angiogenic peptide hormone which regulates blood pressure and vascular integrity. It is highly expressed in both the placenta and vascular endothelial cells. We performed a nested case-control study, selected from a large prospective cohort of over 2000 participants. Circulating ADM mRNA was reduced at both 28 (n = 39 vs 248 controls, p = 0.005) and 36 weeks' of pregnancy (n = 39 vs 205 controls, p < 0.0001) in those destined to develop term preeclampsia. It was also significantly reduced in the circulation of women with established early-onset preeclampsia (n = 34 vs 21 controls, p = 0.01). ADM mRNA (n = 34 vs 12 controls) and protein (n = 53 vs 17 controls) were significantly decreased in placental tissue from women with early-onset preeclampsia (p = 0.02, p = 0.0002 respectively), suggesting the placenta is a possible source of the reduced circulating mRNA. Functional studies in primary endothelial cells revealed significantly reduced ADM mRNA expression when cells were exposed to cytotrophoblast conditioned media (derived from normotensive pregnancies, p < 0.0001) or TNFα (p < 0.0001), suggesting another possible source of reduced circulating ADM mRNA is the endothelium. Circulating ADM mRNA, but not protein, is reduced 10-12 weeks before the diagnosis of term preeclampsia. It may be of endothelial or placental origin. Whole blood mRNA is a rich source of potential biomarker discovery in the prediction of preeclampsia. [ABSTRACT FROM AUTHOR]

Preeclampsia is a hypertensive disorder of pregnancy characterized by maternal endothelial dysfunction and end-organ damage. The antiangiogenic factor, sFlt-1 (soluble FMS-like tyrosine kinase-1) has been strongly implicated in the pathogenesis of preeclampsia. sFlt-1 is secreted into the maternal circulation where it antagonizes VEGF (vascular endothelial growth factor) and ultimately disrupts vascular homeostasis. However, the upstream mechanisms regulating release of sFlt-1 are poorly characterized. We investigated the roles of key prosurvival pathways, EGFR (epidermal growth factor receptor) signaling, and the mitochondria, in regulating sFlt-1 production. We initially found that the mRNA and protein of EGFR and downstream adaptor molecules were significantly increased in preeclamptic placental tissue relative to normotensive controls. Inhibiting the EGFR signaling cascade using siRNA (small interfering ribonucleic acid) or small molecule inhibitors significantly reduced sFlt-1 release from primary cytotrophoblast (placental cells). Additionally, inhibiting the mitochondrial electron transport chain or activating downstream energy-sensing molecules (AMPK [AMP-activated kinase], SIRT1 [sirtuin 1 ], and PGC1α [PPAR-γ co-activator 1]) also significantly reduced sFlt-1 secretion from cytotrophoblast cells, without affecting EGFR signaling. In vivo, treating pregnant mice with gefitinib (an EGFR inhibitor) or resveratrol (perturbs mitochondrial function) significantly reduced circulating murine sFlt-1 compared with vehicle control. Furthermore, treating primary cytotrophoblasts with therapeutics which have been previously found to reduce sFlt-1 secretion, either reduced EGFR signaling (esomeprazole and statins) or perturbed mitochondrial function (esomeprazole, resveratrol, and metformin). Additionally, targeting both pathways simultaneously produced additive reductions in sFlt-1 secretion. Thus, we have identified 2 key survival pathways that seem to be overactive in preeclampsia and involved in the regulation of placental sFlt-1 secretion. [ABSTRACT FROM AUTHOR]

Preeclampsia is associated with intermittent placental hypoxia, inflammation and the release of antiangiogenic factors, namely sFLT-1 and sEng. These factors cause maternal endothelial dysfunction and the manifestation of clinical disease. Disulfiram is a dehydrogenase inhibitor used to treat alcoholism and has been suggested as a proteasome inhibitor. Inhibiting the proteasome has been previously shown to reduce FLT-1 gene expression. Thus, we aim to investigate whether disulfiram alters the secretion of sFLT-1 and sEng and reduces endothelial dysfunction. METHODS AND RESULTS: We assessed the effects of disulfiram on primary cytotrophoblast and human umbilical vein endothelial cells (HUVECs). Disulfiram significantly reduced mRNA expression of membrane bound FLT-1 and sFLT-1 variants in primary cytotrophoblasts, which translated into a significant reduction in the protein secretion of sFLT-1. Additionally, sFLT-1 was reduced in primary HUVECs treated with disulfiram, whilst sEng was only reduced in primary cytotrophoblasts. Next, we investigated the effect of disulfiram on endothelial dysfunction using primary HUVECs treated with 5% preeclamptic serum ± disulfiram. Serum from preeclamptic women induced endothelial dysfunction evidenced by increased mRNA expression of vascular cell adhesion molecule-1 (VCAM-1) and adhesion of peripheral blood mononuclear cells (PBMCs) to HUVECs. The addition of disulfiram reduced VCAM-1 mRNA expression, however did not affect the adhesion of PBMCs to endothelial cells. Lastly, we assessed the effects of disulfiram on the 20S subunit of the proteasome and found disulfiram did not inhibit this subunit in either primary cytotrophoblast or HUVECs. CONCLUSIONS: Disulfiram quenches sFLT-1 and sEng via mechanisms independent of the 20S subunit of the proteasome. Understanding of the mechanisms by which disulfiram inhibits antiangiogenic secretion may reveal insights into the pathogenesis and potential therapeutic targets for preeclampsia. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia is a severe complication of pregnancy, and likely arises from abnormal placental development in early pregnancy. Persistent placental hypoxia is thought to trigger the release of anti-angiogenic factors into the maternal circulation leading to widespread endothelial dysfunction. Epidermal growth factor-like domain 7 (EGFL7) is a secreted angiogenic factor that may play a key role in the disrupted angiogenesis seen in response to placental hypoxia that characterizes preeclampsia.Methods: Primary trophoblasts were isolated and cultured in both normoxic and hypoxic conditions. Under hypoxia HIF1α was silenced and EGFL7 mRNA expression was assessed. EGFL7 mRNA expression was measured in placentas obtained from women with early (<34 weeks) and late onset preeclampsia; and in peripheral whole blood maternal samples from women with preeclampsia and gestation matched controls. EGFL7 plasma levels were assessed in plasma from women with preeclampsia, compared to gestation-matched controls.Results: EGFL7 expression was significantly upregulated in primary human trophoblasts cultured in hypoxia (>2-fold, p < 0.0001), however this was not regulated via a HIF1α dependent manner. EGFL7 mRNA expression was not altered in placenta from women with early or late onset preeclampsia. Circulating EGFL7 protein levels were not different in women with severe preeclampsia. In contrast, EGFL7 mRNA expression was increased in maternal blood in women with early onset preeclampsia (∼1.6-fold, p < 0.05).Discussion: EGFL7 mRNA expression is increased with hypoxia in human trophoblast and is increased in the maternal circulation in women with preeclampsia. Further studies aimed at understanding the role and regulation of EGLF7 in the pathophysiology of preeclampsia are required. [ABSTRACT FROM AUTHOR]

Introduction: Preeclampsia is a serious pregnancy complication for which there are no medical treatments. Soluble endoglin is an anti-angiogenic factor implicated in the pathogenesis of the disease, however little is known about its molecular regulation. The PI3K/Akt pathway is down regulated in preeclamptic placentas and decreased PI3K/Akt signaling has been linked to increased soluble endoglin release from endothelial cells. MMP14 is a key protease that functions to release soluble endoglin from the placental surface.Objective: This study aimed to determine whether reduced placental PI3K/Akt causes elevated release of soluble endoglin via MMP14.Study Design: Akt mRNA and protein expression were assessed in early onset preeclamptic and preterm control placentas (delivered <34weeks gestation). PI3K/Akt inhibition was achieved by administering PI3K inhibitor wortmannin, a specific Akt inhibitor or Akt siRNA to primary human umbilical vein endothelial cells, primary trophoblast and placental explants. The effect of PI3K/Akt inhibition on soluble endoglin release, MMP14, endoglin and TIMP-3 mRNA expression was determined.Results: We identified significantly reduced pAkt and total Akt in preeclamptic placentas relative to preterm control. Inhibition of PI3K/Akt resulted in significantly elevated soluble endoglin release from HUVECs, had no effect on MMP14 mRNA expression but resulted in significantly reduced TIMP3. In contrast inhibiting PI3K/Akt in placental explants or primary trophoblast did not change soluble endoglin release.Conclusion: This study confirms that the PI3K/Akt cell protection pathway is down regulated in preeclampsia, but demonstrates that this dysregulation is unlikely to be responsible for the excessive placental soluble endoglin release characteristic of preeclampsia. [ABSTRACT FROM AUTHOR]

There is recent interest for uniform placental collection protocols so laboratories can share samples. However, concerns have been raised a wash step at collection causes significant loss of sFlt-1 and soluble endoglin, among the most studied proteins in placentology. We measured Flt-1 and endoglin mRNA and protein in 10 preeclamptic placentas that were washed, or left unwashed. Reassuringly, there was no significant change in the Flt-1, sFlt-1-e15a or sFlt-1-i13 mRNA or Flt-1 or sFlt-1 protein expression or localization. There was also no change in endoglin mRNA expression or protein localization. Washing preeclamptic placental samples does not alter anti-angiogenic factor expression. [ABSTRACT FROM AUTHOR]

Objectives: To examine the effect of sildenafil on level of antiangiogenic proteins of preeclampsia. Firstly to examine the effect of sildenafil on serum biomarkers in a patient with preterm preeclampsia. Secondly, to examine the effect of sildenafil on sFlt-1 and soluble endoglin secretion from primary trophoblasts and placental explants.Study Design: The clinical team administered 50 mg tds sildenafil to a 26-year-old primigravid woman with severe preeclampsia at the threshold of viability (24 3/7 weeks gestation) and we collected bloods to examine the effect of slidenafil on antiangiogenic factors sFlt-1 and soluble endoglin (sENG), pro-angiogenic factor PlGF and vascular cell adhesion molecule 1 (VCAM-1) and endothelin-1 (ET1). We administered sildenafil to human primary trophoblasts and placental explants and explored its effect on sFlt-1 and sENG secretion.Main Outcome Measures: We examined serum anti-angiogenic factors sFlt-1 and sENG, pro-angiogenic factor PlGF, the potent vasoconstrictor ET1 and VCAM-1 by ELISA. We explored the effect of sildenafil on sFlt-1 secretion from primary trophoblasts and sFlt-1 and sENG secretion from placental explants.Results: We found a reduction in serum sFlt-1, stabilisation in sENG and PlGF in a patient with peri-viable preterm preeclampsia administered oral sildenafil 50 mg three times daily (tds). Furthermore there was an initial stabilisation in serum VCAM-1 and a decline in ET1 with sildenafil administration. This was concordant with stabilisation of clinical and biochemical features of preeclampsia. Interestingly, treating placental cells and tissues in vitro with sildenafil did not appear to change sFlt-1 or sENG secretion.Conclusion: Sildenafil administration was associated with a reduction in serum sFlt-1 and sENG secretion and increase in PlGF secretion in a patient with preterm preeclampsia, potentially via increasing placental perfusion rather than acting directly on the placenta. [ABSTRACT FROM AUTHOR]

Preeclampsia is a major pregnancy complication associated with poor placental perfusion and placental hypoxia. Systemic and placental inflammation and elevated placental secretion of the antiangiogenic factors sFlt-1 (soluble fms-like tyrosine kinase 1) and sEng (soluble endoglin) are hallmarks of preeclampsia, causing endothelial dysfunction and multiorgan injury. A molecule that links placental hypoxia, inflammation, and antiangiogenic factor release has not been described. ATF3 (activating transcription factor 3) is highly expressed in placenta. We assessed whether placental ATF3 is dysregulated in preterm preeclampsia, is altered by hypoxia, and regulates proinflammatory cytokine and antiangiogenic factor production. ATF3 mRNA and protein expression was significantly reduced in preterm preeclamptic placentas compared with gestation-matched controls. Hypoxia reduced ATF3 expression in primary cytotrophoblast and placental explants. Silencing ATF3 in primary cytotrophoblast increased proinflammatory cytokine (IL-6 [interleukin 6], TNF-α [tumor necrosis factor α]) and NF-κB (nuclear factor κB) expression. In silico analysis identified an ATF3-binding site in the promoter of Flt-1 (the transcript from which sFlt-1 is produced). Silencing ATF3 increased sFlt-1 and sEng secretion from primary cytotrophoblast possibly by increasing Rab11a and Arf1, cargo proteins that facilitate exosomal release of sFlt-1. ATF3 knockout mice did not have a preeclampsia phenotype, suggesting that these pathways may be specific to humans (preeclampsia is a uniquely human condition). To conclude, we have shown that ATF3 is decreased in preeclamptic placentas and that this decrease is likely to occur after prolonged hypoxia. We show that ATF3 is a regulator of placental proinflammatory cytokines and antiangiogenic factors sFlt-1 and sEng. Therefore, reduced ATF3 may be centrally involved in the pathology of preeclampsia. [ABSTRACT FROM AUTHOR]

Preeclampsia is a severe complication of pregnancy. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. Oxidative stress and vascular inflammation exacerbate the endothelial injury. A drug that can block these pathophysiological steps would be an attractive treatment option. Proton pump inhibitors (PPIs) are safe in pregnancy where they are prescribed for gastric reflux. We performed functional studies on primary human tissues and animal models to examine the effects of PPIs on sFlt-1 and soluble endoglin secretion, vessel dilatation, blood pressure, and endothelial dysfunction. PPIs decreased sFlt-1 and soluble endoglin secretion from trophoblast, placental explants from preeclamptic pregnancies, and endothelial cells. They also mitigated tumor necrosis factor-α-induced endothelial dysfunction: PPIs blocked endothelial vascular cell adhesion molecule-1 expression, leukocyte adhesion to endothelium, and disruption of endothelial tube formation. PPIs decreased endothelin-1 secretion and enhanced endothelial cell migration. Interestingly, the PPI esomeprazole vasodilated maternal blood vessels from normal pregnancies and cases of preterm preeclampsia, but its vasodilatory effects were lost when the vessels were denuded of their endothelium. Esomeprazole decreased blood pressure in a transgenic mouse model where human sFlt-1 was overexpressed in placenta. PPIs upregulated endogenous antioxidant defenses and decreased cytokine secretion from placental tissue and endothelial cells. We have found that PPIs decrease sFlt-1 and soluble endoglin secretion and endothelial dysfunction, dilate blood vessels, decrease blood pressure, and have antioxidant and anti-inflammatory properties. They have therapeutic potential for preeclampsia and other diseases where endothelial dysfunction is involved. [ABSTRACT FROM AUTHOR]