Preeclampsia. Part 1: clinical and pathophysiologic considerations

Plasma metabolic profile reveals signatures of maternal health during gestational hypertension and preeclampsia without and with severe features

Preeclampsia, a pregnancy-specific syndrome, poses substantial risks to maternal and neonatal health, particularly in cases with severe features. Our study focuses on evaluating the impact of low molecular weight metabolites on the intricate mechanisms and pathways involved in the pathophysiology of preeclampsia when severe features are present. We aim to pinpoint the distinct metabolomic profile in maternal plasma during pregnancies affected by hypertensive disorders and to correlate the metabolite levels with the clinical characteristics of the study cohort. A total of 173 plasma samples were collected, comprising 36 healthy pregnant women (HP), 52 patients with gestational hypertension (GH), 43 with preeclampsia without (PE-), and 42 with severe features (PE+). Nuclear magnetic resonance spectroscopy and metabolite identification were conducted to establish the metabolomic profiles. Univariate and chemometric analyses were conducted using MetaboAnalyst, and correlations were performed using GraphPad Prism. Our study unveils distinct metabolomic profiles differentiating HP women, patients featuring GH, and patients with PE-and PE+. Our analysis highlights an increase in acetate, N,N-dimethylglycine, glutamine, alanine, valine, and creatine levels in the PE+ group compared to the HP and GH groups. The PE+ group exhibited higher concentrations of N,N-dimethylglycine, glutamine, alanine, and valine compared to the PE-group. Moreover, elevated levels of specific metabolites, including N,N-dimethylglycine, alanine, and valine, were associated with increased blood pressure, worse obstetric outcomes, and poorer end-organ function, particularly renal and hepatic damage. Metabolomic analysis of PE+ individuals indicates heightened disturbances in nitrogen metabolism, methionine, and urea cycles. Additionally, the exacerbated metabolic disturbance may have disclosed renal impairment and hepatic dysfunction, evidenced by elevated levels of creatine and alanine. These findings not only contribute novel insights but also provide a more comprehensive understanding of the pathophysiological mechanisms at play in cases of PE+.

Burden, risk factors, and maternal postpartum and birth outcomes of hypertensive disorder of pregnancy in Ethiopia, 2024: A systematic review and meta-analysis

Objectives

This review aimed to report the estimated pooled level of prevalence, risk factors, and birth outcome of hypertensive disorder of pregnancy in Ethiopia, in 2024.

Design

A systematic review and meta-analysis approach was utilized.

Data Sources and Methods

PubMed/MEDLINE, Google Scholar, African Index Medicus, Web of Science, and CINHAL (EBSCO) search was carried out. The result was written according to the PRISMA-updated guidelines. To estimate the pooled prevalence and effect sizes, a random-effect model was used. Heterogeneity was assessed and investigated using I 2 test statistics and meta-regression, respectively. Publication bias was assessed using funnel plot and Egger's test statistics. Statistical tests result at p-value < 0.05 were declared as having significance.

Result

From a total of 52 primary studies with a total sample size of 269, 158 were included in this systematic review and meta-analysis. The pooled prevalence of hypertensive disorder in pregnancy was 8%. Egger's test statistics (p = 0.8013) showed there is no publication bias. Having a history of kidney disease (AOR: 3.47), being rural resident (AOR: 2.5), having fruit intake during pregnancy (AOR: 0.39), being overweight (AOR: 2.24), and having multiple pregnancy (AOR: 2.1) were found to have a significant association with hypertensive disorder of pregnancy.

Conclusion

Overall, the level of prevalence of hypertensive disorders of pregnancy in Ethiopia was significantly increasing. Having a history of kidney disease was found to have a strong association with hypertensive disorders of pregnancy among factors. The most common or dominant adverse maternal and childbirth outcomes were low birth weight, preterm birth, fifth minute low APGAR score; and eclampsia, hemolysis, elevated liver enzymes, and low platelets syndrome, and acute kidney injury. The governments and other stakeholders should work to broaden and strengthen the existing maternal and child health (MCH) practice by incorporating all possible risk factors of hypertensive disorders of pregnancy in MCH guidelines. In addition, a large-scale study is required that considers those important missed variables, especially, in the eastern part of Ethiopia.

Pravastatin Protects Cytotrophoblasts from Hyperglycemia-Induced Preeclampsia Phenotype

There are no effective therapies to prevent preeclampsia (PE). Pravastatin shows promise by attenuating processes associated with PE such as decreased cytotrophoblast (CTB) migration, aberrant angiogenesis, and increased oxidative stress. This study assesses the effects of pravastatin on hyperglycemia-induced CTB dysfunction.

METHODS

Human CTB cells were treated with 100, 150, 200, 300, or 400 mg/dL glucose for 48 h. Some cells were pretreated with pravastatin (1 µg/mL), while others were cotreated with pravastatin and glucose. The expression of urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1) mRNA, vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble endoglin (sEng) were measured. CTB migration was assayed using a CytoSelect migration assay kit. Statistical comparisons were performed using an analysis of variance with Duncan's post hoc test.

RESULTS

The hyperglycemia-induced downregulation of uPA was attenuated in CTB cells pretreated with pravastatin at glucose levels > 200 mg/dL and cotreated at glucose levels > 300 mg/dL (p < 0.05). Hyperglycemia-induced decreases in VEGF and PlGF and increases in sEng and sFlt-1 were attenuated in both the pretreatment and cotreatment samples regardless of glucose dose (p < 0.05). Pravastatin attenuated hyperglycemia-induced dysfunction of CTB migration.

CONCLUSIONS

Pravastatin mitigates stress signaling responses in hyperglycemic conditions, weakening processes leading to abnormal CTB migration and invasion associated with PE in pregnancy.

Prevalence of persistent hypertension following pregnancy complicated by hypertensive disorders in low- and middle-income countries: a systematic review

Background

Hypertensive disorders of pregnancy can lead to persistent hypertension (pHTN) in the months and even years following delivery. However, its prevalence in low- and middle-income countries (LMICs) is not well characterized.

Objective

To synthesize available evidence on the pHTN prevalence following a pregnancy complicated by hypertensive disorders of pregnancy in LMICs.

Search strategy

PubMed, CINAHL Plus, Global Health (EBSCOhost), and Scopus from inception through a search date of July 12, 2022, and updated on January 2, 2024.

Selection criteria

Cross-sectional studies and cohort studies reporting pHTN prevalence were eligible.

Data collection and analysis

We conducted a narrative synthesis of data and categorized reported prevalence time points into several broader categories. We used the Newcastle-Ottawa checklist to assess the risk of bias. The protocol is registered in PROSPERO (CRD42022345739).

Results

We reviewed 1,584 abstracts and identified 22 studies that reported pHTN between 2000 and 2023 from 14 LMICs. The overall prevalence of pHTN ranged between 6.9% and 62.2%, with the highest prevalence noted within African studies and the lowest in South American studies. Estimates at different follow-up periods postpartum were 6.9%-42.9% at six weeks, 34.0%-62.2% at three months, 14.8%-62.2% at six months, 12.7%-61.2% at 12 months, and 7.5%-31.8% at more than 12 months. The quality score of the selected studies ranged from 50% to 100%.

Conclusions

The extant literature reports a high prevalence of pHTN in LMICs following a pregnancy complicated by hypertensive disorders. To reduce long-term complications of pHTN, programs should emphasize early screening and linkages to long-term care for at-risk women.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=345739, PROSPERO (CRD42022345739).

Predictability of adverse outcomes in hypertensive disorders of pregnancy: a multicenter prospective cohort study

OBJECTIVES

To explore variables associated with adverse maternal/fetal/neonatal outcomes among pregnant/postpartum patients admitted to ICU for hypertensive disorders of pregnancy (HDP).

METHODS

Multicenter, prospective, national cohort study.

RESULTS

Variables independently associated with maternal/fetal/neonatal mortality among 172 patients were as follows: Acute Physiology and Chronic Health Evaluation-II (APACHE-II)(OR1.20[1.06-1.35]), gestational age (OR0.698[0.59-0.82]) and aspartate aminotransferase (AST)(OR1.004[1.001-1.006]). Positive likelihood ratio for headache, epigastric pain, and visual disturbances to predict composite adverse outcomes were 1.23(1.16-1.30), 0.76(0.59-1.02), and 1.1(0.98-1.2), respectively.

CONCLUSIONS

Maternal/fetal mortality due to HDP was independently associated with severity of illness on admission, gestational age, and elevated AST. Accuracy of clinical symptoms to predict composite adverse outcomes was low.

Cartiotonic steroids affect monolayer permeability in lymphatic endothelial cells

Edema is common in preeclampsia (preE), a hypertensive disorder of pregnancy. Cardiotonic steroids (CTSs) such as marinobufagenin (MBG) are involved in the pathogenesis of preE. To assess whether CTSs are involved in the leakage of lymphatic endothelial cell (LEC), we evaluated their effect on monolayer permeability of LECs (MPLEC) in culture. A rat mesenteric LECs were treated with DMSO (vehicle), and CTSs (MBG, CINO, OUB) at concentrations of 1, 10, and 100 nM. Some LECs were pretreated with 1 μM L-NAME (N-Nitro-L-Arginine Methyl Ester) before adding 100 nM MBG or cinobufotalin (CINO). Expression of β-catenin and vascular endothelial (VE)-cadherin in CTS-treated LECs was measured by immunofluorescence and MPLEC was quantified using a fluorescence plate reader. Western blot was performed to measure β-catenin and VE-cadherin protein levels and myosin light chain 20 (MLC20) phosphorylation. MBG (≥ 1 nM) and CINO (≥ 10 nM) caused an increase (p < 0.05) in the MPLEC compared to DMSO while ouabain (OUB) had no effect. Pretreatment of LECs with 1 μM L-NAME attenuated (p < 0.05) the MPLEC. The β-catenin expression in LECs was downregulated (p < 0.05) by MBG and CINO. However, there was no effect on the LECs tight junctions for the CINO group. VE-cadherin expression was downregulated (p < 0.05) by CINO, and MLC20 phosphorylation was upregulated (p < 0.05) by MBG. We demonstrated that MBG and CINO caused an increase in the MPLEC, which were attenuated by L-NAME pretreatment. The data suggest that CTSs exert their effect via nitric-oxide-dependent signaling pathway and may be involved in vascular leak syndrome of LEC lining in preE.

Maternal and Fetal Outcomes of Pregnancy-related Hypertensive Disorders in a Tertiary Care Hospital in Sukkur, Pakistan

Introduction Pregnancy-related hypertensive disorders are a significant cause of adverse maternal and fetal outcomes, especially in developing areas of the world. Preeclampsia and eclampsia are the most significant causes of maternal and perinatal morbidity and mortality. Methods We conducted a prospective observational study in the Obstetrics and Gynaecology Department of Ghulam Muhammad Meher Medical College and Hospital. One hundred twelve (n=112) women with pregnancy-related hypertensive disorders admitted for delivery were included in the study. Results The major pregnancy-related hypertensive disorder was eclampsia (n=48; 43.24%) and preeclampsia (n=28; 25.23%). Among the women who developed one or more complications during or after delivery, postpartum hemorrhage (PPH) was the most frequent (n=31; 27.6%). Conclusions Pregnancy-related hypertensive disorders are common and adversely impact maternal and fetal outcomes. Efforts should be made at both the community and hospital levels to increase awareness regarding hypertensive disorder of pregnancy and reduce its associated morbidity and mortality.

Diabetes and pre-eclampsia affecting pregnancy: a retrospective cross-sectional study

The interaction between pre-eclampsia and diabetes mellitus (DM) is far from being completely understood. In this study, we compared normal pregnancies with those complicated with pre-eclampsia, gestational DM, and/or pre-existing diabetes to assess the effects of hyperglycemia on placental development. AnInstitutional Review Board (IRB) approved retrospective cross-sectional study with 621 subjects was performed. Statistical analysis was performed using Duncan's post hoc test and analysis of variance. Regardless of diabetes status, patients with pre-eclampsia delivered prematurely. Patients in the group with pre-eclampsia and pregestational diabetes delivered much earlier, at 35.0±0.4 weeks, when compared with the patients that had pre-eclampsia with gestational diabetes and pre-eclampsia with no diabetes (*P<0.05 for each). Additionally, patients with pre-existing diabetes who developed pre-eclampsia delivered smaller babies than those with pre-existing diabetes without pre-eclampsia (1.00±0.03, P<0.05 for each). Pre-existing diabetes with added insult of pre-eclampsia led to fetal growth restriction. This outcome validates the understanding that elevated glucose earlier in pregnancy alters placentogenesis and leads to fetal growth restriction.

Oxidative Stress in the Rostral Ventrolateral Medulla Contributes To Cardiovascular Regulation in Preeclampsia

Background: It has been demonstrated that preeclampsia, a pregnancy-specific hypertension disorder, is characterized by high blood pressure (BP) and sympathetic overactivity. Increased reactive oxygen species (ROS) in the rostral ventrolateral medulla (RVLM), a key region for controlling sympathetic tone, has been reported to contribute to high level of BP and sympathetic outflow. The aim of the present study was to determine the role of the RVLM ROS in mediating the preeclampsia-associated cardiovascular dysfunction.

Methods: The animal model of preeclampsia was produced by administration of desoxycorticosterone acetate (DOCA) to pregnant rats.

Results: Compared with normal pregnant rats without DOCA treatment (NP), the protein concentration and norepinephrine excretion in 24-h urine, as well as BP in pregnant rats with DOCA treatment (PDS) were significantly increased. The levels of superoxide anion and the protein expression of NADPH oxidase subtype (NOX4) in the RVLM were significantly increased in PDS than in NP groups. Furthermore, microinjection of the superoxide dismutase (SOD) mimic Tempol (5 nmol) into the RVLM significantly decreased BP, heart rate, and renal sympathetic never activity in PDS but not in NP group.

Conclusion: The present data suggest that high BP and sympathetic overactivity in preeclampsia rats is associated with increased oxidative stress in the RVLM via upregulation of NOX4 expression.

Synthetic Receptors Induce Anti Angiogenic and Stress Signaling on Human First Trimester Cytotrophoblast Cells

The cytotrophoblast (CTB) cells of the human placenta have membrane receptors that bind certain cardiotonic steroids (CTS) found in blood plasma. One of these, marinobufagenin, is a key factor in the etiology of preeclampsia. Herein, we used synthetic receptors (SR) to study their effectiveness on the angiogenic profile of human first trimester CTB cells. The humanextravillous CTB cells (Sw.71) used in this study were derived from first trimester chorionic villus tissue. Culture media of CTB cells treated with ≥1 nM SR level revealed sFlt-1 (Soluble fms-like tyrosine kinase-1) was significantly increased while VEGF (vascular endothelial growth factor) was significantly decreased in the culture media (* p < 0.05 for each) The AT₂ receptor (Angiotensin II receptor type 2) expression was significantly upregulated in ≥1 nM SR-treated CTB cells as compared to basal; however, the AT₁ (Angiotensin II receptor, type 1) and VEGFR-1 (vascular endothelial growth factor receptor 1) receptor expression was significantly downregulated (* p < 0.05 for each). Our results show that the anti-proliferative and anti-angiogenic effects of SR on CTB cells are similar to the effects of CTS. The observed anti angiogenic activity of SR on CTB cells demonstrates that the functionalized-urea/thiourea molecules may be useful as potent inhibitors to prevent CTS-induced impairment of CTB cells.

Cinobufotalin impedes Sw.71 cytotrophoblast cell line function via cell cycle arrest and apoptotic signaling

Preeclampsia (preE) is a hypertensive disorder of pregnancy. Cardiotonic steroids (CTS) are endogenous inhibitors of Na⁺/K⁺ ATPase, and at least one CTS, marinobufagenin (MBG), is elevated in a rat model of preE prior to the development of the syndrome. MBG and ouabain impair cytotrophoblast (CTB) cell function, which is critical for placental development. We evaluated the effect of a CTS, cinobufotalin (CINO), on CTB cell function in vitro. CINO at ≥1 nM inhibited CTB cell proliferation, migration, and invasion (p < 0.05), but had no effect on cell viability. There was a higher (p < 0.05) percentage of G0/G1 phase cells in groups treated with CINO at ≥1 nM. CINO caused an increase in stress signaling p38 MAPK and a positive annexin-V staining in CTB cells, indicating the activation of apoptotic signaling. However, the CINO-induced apoptotic signaling was prevented by p38 inhibition. These data demonstrate that CINO impairs CTB cell function via cell cycle arrest and apoptotic signaling.

Hemostatic Abnormalities in Patients With Severe Preeclampsia

Preeclampsia is the most common medical disorder of pregnancy. Early onset preeclampsia is defined as presentation of hypertension and proteinuria before 34 weeks of gestation. Alterations of endothelial cells and fibrin deposition in microvasculature lead to enhanced activation of the coagulation cascade and impaired fibrinolysis associated with multiple organ dysfunctions. Plasma samples were obtained from 50 patients with severe preeclampsia before 34 weeks of gestation and in 61 patients with late preeclampsia. Factor VIIIR:Ag, fibrinogen, D-dimer, and thrombomodulin increased with advanced pregnancy. The platelet count is very important because of the close correlation with the activations parameters of D-dimer and antithrombin. Our results were consistent with activated coagulation and lowering of platelet count in severe cases with early onset preeclampsia. Women who develop early onset preeclampsia characterized a subgroup of patients with more and severe hematologic abnormalities than women with late preeclampsia (after 34 weeks of gestation).

Attenuation of hyperglycemia-induced apoptotic signaling and anti-angiogenic milieu in cultured cytotrophoblast cells

OBJECTIVE

Preeclampsia (preE) is a hypertensive disorder that occurs 20% in diabetic pregnancy. We have shown that hyperglycemia impairs cytotrophoblast cell (CTB) function. In this study, we assess apoptotic and anti-angiogenic signaling in excess glucose-induced CTBs.

STUDY DESIGN

Human extravillous CTBs (Sw. 71) were treated with 100, 150, 200, 300, or 400 mg/dL glucose for 48 h. Some cells were pretreated with a p38 inhibitor (SB203580) or a peroxisome proliferator-activated receptor gamma (PPARγ) ligand (rosiglitazone) or with D-mannitol. Cell lysates were utilized to measure p38 MAPK phosphorylation, PPARγ, Bcl-2-associated-X protein (Bax), anti-apoptotic Bcl-2, caspase-9, and cyclooxygenase-2 (Cox-2) expression by western blot. Levels of the vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), and interleukin 6 (IL-6) were measured in culture media using ELISA kits. Statistical comparisons were performed using analysis of variance with Duncan's post hoc test.

RESULTS

p38 phosphorylation and PPARγ were upregulated (p < 0.05) in CTBs treated with ≥150 mg/dL glucose compared to basal (100 mg/dL). Expressions of Bax/Bcl-2, Cox-2, and caspase-9 were upregulated (p < 0.05) in CTBs treated with ≥150 mg/dL glucose. Secretion of sFlt-1, sEng, and IL-6 was increased while VEGF and PIGF were decreased in CTB-treated ≥150 mg/dl of glucose (*p < 0.01 for each). SB203580 or rosiglitazone pretreatment significantly attenuated hyperglycemia-induced apoptotic and anti-angiogenic signaling. D-Mannitol had no effect.

CONCLUSION

Hyperglycemia induced apoptotic and anti-angiogenic signaling in CTBs. The observed diminution of hyperglycemia-induced signaling by SB203580 or rosiglitazone pretreatment suggests the involvement of apoptotic and anti-angiogenic signaling in CTB dysfunction.

Elevation of (Pro)Renin and (Pro)Renin Receptor in Preeclampsia

OBJECTIVE

Preeclampsia (preE), a syndrome of hypertension, proteinuria, and edema, has many elusive triggers. The renin-angiotensin system has been implicated in preE pathogenesis. In this study, we test the hypothesis that (pro)renin levels are increased in preE patients and that levels of (pro)renin and (pro)renin receptor ((P)RR) are elevated in a rat model of preE.

METHODS

We recruited 30 preE and 43 normal pregnant consenting patients. We used normally pregnant rats (NP, n = 10) and pregnant rats receiving weekly injections of desoxycorticosterone acetate and whose drinking water was replaced with 0.9% saline (preE, n = 10). Plasma and placental levels of (pro)renin were assayed by ELISA. Placental and kidney (P)RR was measured both by immunoblotting and immunohistochemistry.

RESULTS

The mean plasma (pro)renin of 27.1±5.2 in preE patients differs from that in patients without preE: 14.8±5.2 ng Ang I/ml/hour (P < 0.0001). In rats, both plasma (NP: 22.7±4.3 and preE: 49.2±10.0 ng Ang I/ml/hour) and placental (NP: 152±24 and preE: 302±39 ng/g tissue) levels of (pro)renin were higher (P < 0.001) in preE compared to NP rats. (P)RR expression was greater (P < 0.05) in placental tissue of preE rats, while kidney (P)RR expression was similar.

CONCLUSION

Elevated levels of circulating (pro)renin have been observed in preE patients and in a rat model of preE. We also found the increased expression of placental (P)RR in preE rats.

Hyperglycemia down-regulates cGMP-dependent protein kinase I expression in first trimester cytotrophoblast cells

Diabetes in pregnancy is associated with microvascular complications and a higher incidence of preeclampsia. The regulatory signaling pathways involving nitric oxide, cGMP, and cGMP-dependent protein kinase (PKG) have been shown to be down-regulated under diabetic conditions and contribute to the pathogenesis of vascular complications in diabetes. The present study was undertaken to investigate how high glucose concentrations regulate PKG expression in cytotrophoblast cells (CTBs). Human CTBs (Sw. 71) were treated with 45, 135, 225, 495, or 945 mg/dL glucose for 48 h. Some cells were pretreated with a p38 inhibitor (10 μM SB203580) or 10 μM rosiglitazone. After treatment, the cell lysates were subjected to measure the expression of protein kinase G1α (PKG1α), protein kinase G1β (PKG1β), soluble guanylate cyclase 1α (sGC1α), and soluble guanylate cyclase 1 β (sGC1β) by Western blot. Statistical comparisons were performed using analysis of variance with Duncan's post hoc test. The expressions of PKG1α, PKG1β, sGC1α, and sGC1β were significantly down-regulated (p < 0.05) in CTBs treated with >135 mg/dL glucose compared to basal (45 mg/dL). The hyperglycemia-induced down-regulation of cGMP and cGMP-dependent PKG were attenuated by the SB203580 or rosiglitazone pretreatment. Exposure of CTBs to excess glucose down-regulates cGMP and cGMP-dependent PKG, contributing to the development of vascular complications in diabetic mothers during pregnancy. The attenuation of hyperglycemia-induced down-regulation of PKG proteins by SB203580 or rosiglitazone pretreatment further suggests the involvement of stress signaling mechanisms in this process.

Hyperglycemia impairs cytotrophoblast function via stress signaling

OBJECTIVE

Diabetes mellitus is a risk factor for preeclampsia. Cytotrophoblast (CTB) invasion is facilitated from the conversion of plasminogen to plasmin by urokinase plasminogen activator (uPA), regulated by plasminogen activator inhibitor 1 (PAI-1), and may be inhibited in preeclampsia. This study assessed signaling mechanisms of hyperglycemia-induced CTB dysfunction.

STUDY DESIGN

Human CTBs were treated with 45, 135, 225, 495, or 945 mg/dL glucose for 48 hours. Some cells were pretreated with a p38 inhibitor (SB203580) or a peroxisome proliferator-activated receptor-gamma (PPAR-γ) ligand (rosiglitazone). Expression of uPA, PAI-1, and PPAR-γ levels and p38 mitogen-activated protein kinase phosphorylation were measured by Western blot in cell lysates. Messenger ribonucleic acid of uPA and PAI-1 was measured by quantitative polymerase chain reaction. Levels of interleukin-6, angiogenic (vascular endothelial growth factor [VEGF], placenta growth factor [PlGF]) and antiangiogenic factors (soluble fms-like tyrosine kinase-1 [sFlt-1], soluble endoglin [sEng]) were measured in the media by enzyme-linked immunosorbent assay kits. Statistical comparisons were performed using analysis of variance with a Duncan's post-hoc test.

RESULTS

Both uPA and PAI-1 protein and messenger ribonucleic acid were down-regulated (P < .05) in CTBs treated with 135 mg/dL glucose or greater compared with basal (45 mg/dL). The sEng, sFlt-1, and interleukin-6 were up-regulated, whereas the VEGF and PlGF were down-regulated by 135 mg/dL glucose or greater. p38 phosphorylation and PPAR-γ were up-regulated (P < .05) in hyperglycemia-treated CTBs. The SB203580 or rosiglitazone pretreatment showed an attenuation of glucose-induced down-regulation of uPA and PAI-1.

CONCLUSION

Hyperglycemia disrupts the invasive profile of CTB by decreasing uPA and PAI-1 expression; down-regulating VEGF and PlGF; and up-regulating sEng, sFlt-1, and interleukin-6. Attenuation of CTB dysfunction by SB203580 or rosiglitazone pretreatment suggests the involvement of stress signaling.

Suppression of aldosterone and progesterone in preeclampsia

OBJECTIVE

Preeclampsia (preE) is a hypertensive disorder seen in 3-10% of human pregnancies and is diagnosed by de novo onset of hypertension and proteinuria. Several research groups provided evidence for reduced aldosterone (Aldo) and progesterone (Prog) availability in preE. The aim of this study was to determine the levels of Aldo and Prog in preE.

METHODS

Normal pregnant (NP; n = 39) and preE (n = 30) patients were recruited to have their blood drawn between 21 and 40 weeks of pregnancy. Two groups of rats were used in this study: NP rats (n = 10) and preE rats (n = 10), which were given weekly injections of desoxycorticosterone acetate and 0.9% saline to drink. Aldo and Prog levels were assayed in plasma and urine samples by ELISA kits.

RESULTS

In preE patients, the mean Aldo and Prog levels were suppressed (p < 0.05) compared to NP patients. NP patients exhibited a trend of increased levels of Aldo with an increase in gestational age; however, preE patients had the opposite trend. Both normal and preE patients exhibited a trend of increased levels of Prog with an increase in gestational age. The plasma and urinary Aldo and Prog levels were lower (p < 0.05) in preE rats compared to NP rats.

CONCLUSIONS

We have demonstrated using a rat model and patients that both Aldo and Prog are suppressed in preE and thus may be used as biomarkers for preE.

A synthetic thiourea-based tripodal receptor that impairs the function of human first trimester cytotrophoblast cells

A synthetic tripodal-based thiourea receptor (PNTTU) was used to explore the receptor/ligand binding affinity using CTB cells. The human extravillous CTB cells (Sw.71) used in this study were derived from first trimester chorionic villus tissue. The cell proliferation, migration and angiogenic factors were evaluated in PNTTU-treated CTB cells. The PNTTU inhibited the CTBs proliferation and migration. The soluble fms-like tyrosine kinase-1 (sFlt-1) secretion was increased while vascular endothelial growth factor (VEGF) was decreased in the culture media of CTB cells treated with ≥1 nM PNTTU. The angiotensin II receptor type 2 (AT2) expression was significantly upregulated in ≥1 nM PNTTU-treated CTB cells in compared to basal; however, the angiotensin II receptor, type 1 (AT1) and vascular endothelial growth factor receptor 1 (VEGFR-1) expression was downregulated. The anti-proliferative and anti-angiogenic effect of this compound on CTB cells are similar to the effect of CTSs. The receptor/ligand affinity of PNTTU on CTBs provides us the clue to design a potent inhibitor to prevent the CTS-induced impairment of CTB cells.

Marinobufagenin regulates permeability and gene expression of brain endothelial cells

Marinobufagenin (MBG) is a cardiotonic steroid that increases in the circulation in preeclampsia. Preeclampsia and eclampsia are associated with cerebral edema. Therefore, we examined the effects of MBG on human brain microvascular endothelial cells (HBMEC) in vitro. MBG enhanced the permeability of HBMEC monolayers at 1-, 10-, and 100-nM doses, but had no effect at 0.1 nM. Agilent Human Gene Expression microarrays were utilized in these studies. MBG treatment (10 nM for 12 h) downregulated concentrations of the soluble VEGFR transcript sFLT by 59% but did not alter those of FLTv3 mRNA (determined by quantitative PCR). When treated and control HBMEC transcriptomes were interrogated on microarrays, 1,069 genes appeared to be regulated by MBG. Quantitative RT-PCR confirmed that MBG treatment upregulated ENKUR mRNA concentrations by 57%. Its protein product interacts with calmodulin and calcium channel proteins. MBG treatment downregulated several genes whose protein products are involved in cell adhesion (ITGA2B, FERMT1, CLDN16, and TMEM207) and cell signaling (GRIN2C, SLC8A1, and ESR1). The level of downregulation ranged from 22 to 66%. Altogether, MBG actively enhanced the permeability of HBMEC monolayers while downregulating genes involved in adhesion. MBG treatment had variable effects on ENKUR, GRIN2C, and SLC8A1 genes, all associated with calcium transport. These studies provide the basis for future investigations of MBG actions in normal physiology and disease.

Matrix metalloproteinases as drug targets in preeclampsia

Preeclampsia is an important syndrome complicating pregnancy. While the pathogenesis of preeclampsia is not entirely known, poor placental perfusion leading to widespread maternal endothelial dysfunction is accepted as a major mechanism. It has been suggested that altered placental expression of matrix metalloproteinases (MMPs) may cause shallow cytotrophoblastic invasion and incomplete remodeling of the spiral arteries. MMPs are also thought to link placental ischemia to the cardiovascular alterations of preeclampsia. In fact, MMPs may promote vasoconstriction and surface receptors cleavage affecting the vasculature. Therefore, the overall goal of this review article is to provide an overview of the pathophisiology of preeclampsia, more specifically regarding the role of MMPs in the pathogenesis of preeclampsia and the potential of MMP inhibitors as therapeutic options.

Endothelial NO Synthase Augments Fetoplacental Blood Flow, Placental Vascularization, and Fetal Growth in Mice

It is not known whether eNOS deficiency in the mother or the conceptus (ie, placenta and fetus) causes fetal growth restriction in mice lacking the endothelial NO synthase gene (eNOS knockout [KO]). We hypothesized that eNOS sustains fetal growth by maintaining low fetoplacental vascular tone and promoting fetoplacental vascularity and that this is a conceptus effect and is independent of maternal genotype. We found that eNOS deficiency blunted fetal growth, and blunted the normal increase in umbilical blood flow and umbilical venous diameter and the decrease in umbilical arterial Resistance Index in late gestation (14.5–17.5 days) in eNOS KO relative to C57Bl/6J controls. On day 17.5, fetoplacental capillary lobule length and capillary density in vascular corrosion casts were reduced in eNOS KO placentas. Reduced vascularization may be a result of decreased vascular endothelial growth factor mRNA and protein expression in eNOS KO placentas at this stage. These factors, combined with significant anemia found in eNOS KO fetuses, would be anticipated to reduce fetal oxygen delivery and contribute to the fetal tissue hypoxia that was detected in the heart, lung, kidney, and liver by immunohistochemistry using pimonidazole. Although maternal eNOS deficiency impairs uteroplacental adaptations to pregnancy, maternal genotype was not a significant factor affecting growth in heterozygous conceptuses. This indicates that fetal growth restriction was primarily caused by conceptus eNOS deficiency. In mice, placental hemodynamic and vascular changes with gestation and growth restriction showed strong parallels with human pregnancy. Thus, the eNOS KO model could provide insights into the pathogenesis of human intrauterine growth restriction.

Pathogenesis of pre-eclampsia: marinobufagenin and angiogenic imbalance as biomarkers of the syndrome

Pre-eclampsia (preE), a pregnancy disorder with the de novo onset of hypertension and proteinuria after 20 weeks of gestation, has multiple triggers that initiate pathophysiologic mechanisms. This review addresses translational aspects of preE by synthesizing information on preE pathogenesis, describing diagnostic biomarkers that predict disease, and suggesting strategies to lessen adverse outcomes. Key to this understanding is the role of cardiotonic bufodienolides, with marinobufagenin (MBG) as the prototype, and angiogenic factors in preE pathogenesis. Data from a rat model believed to mimic human preE show that urinary excretion of MBG increases before the onset of hypertension and proteinuria and that affected animals have an increased vascular leakage and blood brain barrier permeability. Angiogenic imbalance occurs with the onset of the syndrome in this model. Also, we report that MBG levels in preE patients exceed those in normal pregnancy and that angiogenic factors are altered in patients showing signs and symptoms of overt disease. In vitro administration of MBG inhibits cytotrophoblast function and triggers hyperpermeability in endothelial cell monolayers. We advance the hypotheses that MBG precedes preE; MBG causes disruption of tight junction proteins leading to vascular leak via activation of MAPK which triggers apoptotic mechanisms resulting in further endothelial dysfunction leading to edema with the release of angiogenic factors. This review provides new evidence about the role of MBG and vasoactive intermediates in preE pathogenesis including the neurologic sequela and may reveal new therapeutic targets for the prevention of preE complications.

The pathophysiology of preeclampsia in view of the two-stage model

Preeclampsia is a common and severe disease in pregnancy, a major cause of maternal and fetal morbidity and mortality. The main features of the disease are de novo hypertension after the 20th gestational week and proteinuria, and it is frequently accompanied by edema and other subjective symptoms. The origin of the disease is the placenta, but its sequelae affect multiple organ systems. According to the two-stage model of preeclampsia, the abnormal and hypoperfused placenta (stage 1) releases factors to the bloodstream, which are responsible for the maternal symptoms (stage 2). Oxidative stress, impaired function of nitric-oxide synthase, cellular and humoral immunological factors play an important role in the pathophysiology of the placenta. Endothelial dysfunction is the common denominator of the clinical symptoms. The theory explains the origins of hypertension, proteinuria, edema and other symptoms as well. Orv. Hetil., 2012, 153, 1167–1176.

Periodontitis as a risk factor for preeclampsia

BACKGROUND

Periodontitis is an inflammatory process caused by a specific group of microorganisms, resulting in the destruction of the tooth-supporting tissue and the resorption of the alveolar bone. Therefore, periodontitis has been considered a risk factor for preeclampsia because infection is one of the factors involved in the etiology and pathogenesis of preeclampsia. The aim of the present study is to determine whether periodontitis is a risk factor for preeclampsia and to identify other possible risk factors.

METHODS

A case-control study was performed with 574 puerperae under care at the university hospital at the Universidade Federal de Pernambuco in the city of Recife, Brazil. Data collection was preceded by a training exercise and a pilot study. Biologic and socioeconomic data were collected along with medical and dental records. A periodontal examination was performed on all dental elements to determine probing depth and gingival recession. The association between periodontitis and preeclampsia was first adjusted for the variables within each block, and adjusted for the variables of all blocks in the final multivariate model.

RESULTS

The multivariate logistic regression analysis showed that, after adjustment for other risk factors, periodontitis remained an independent risk factor for preeclampsia (adjusted odds ratio [OR] = 8.60, confidence interval [CI] = 3.92 to 18.88, P < 0.001 and adjusted OR = 2.03, 95% CI = 1.43 to 2.90, P < 0.001, when using the Centers for Disease Control and Prevention/American Academy of Periodontology definition).

CONCLUSION

The results suggest that within the population studied, periodontitis was a risk factor for preeclampsia.

A chemifluorescent immunoassay for the determination of marinobufagenin in body fluids

We describe here the development of a chemifluorescent competitive enzyme-linked immunosorbent assay (ELISA) that quantifies marinobufagenin (MBG) levels in biological fluids. Based on a polyclonal antibody raised against a novel MBG-bovine serum albumin conjugate, this assay achieved an MBG detection limit of less than 9 pg/mL. MBG levels in various rat urine and serum samples were effectively determined using this methodology. Interassay variability averaged 9.8%, while intra-assay variability averaged 1.9 and 2.5% in representative serum and urine samples, respectively. Recovery of exogenously added MBG averaged 106%, and parallelism data further established the accuracy of the assay. Employment of this assay to detect MBG abnormalities represents a powerful tool for the possible diagnosis, prevention and management of human hypertensive states, particularly preeclampsia.

Genetic variation in solute carrier genes is associated with preeclampsia

OBJECTIVE

The objective of the study was to evaluate allelic variation in 26 members of the solute carrier (SLC) gene family for an association with preeclampsia.

STUDY DESIGN

Preeclampsia cases were women with mild or severe preeclampsia. Controls were enrolled from women without hypertension-related complications who presented for delivery at term (≥37 weeks). The association between preeclampsia and SLC gene single-nucleotide polymorphisms (SNPs) and haplotypes was evaluated by logistic regression models.

RESULTS

Rs4957061 in SLC9A3 was significantly associated with a reduced risk of preeclampsia in whites (T allele, P = .002; odds ratio [OR], 0.33; 95% confidence interval [CI], 0.16-0.67). For SLC4A1 in blacks, the G allele of rs2074107 (P = .004; OR, 1.56; 95% CI, 1.15-2.12) and the A allele of rs2857078 (P < .001; OR, 1.67; 95% CI, 1.27-2.17) were significantly associated with preeclampsia. Also in blacks, rs10066650 in SLCO4C1 (G allele, P = .002; OR, 1.72; 95% CI, 1.21-2.46) was significantly associated with increased risk. Sliding window haplotype analyses identified significantly associated haplotypes in these genes.

CONCLUSION

SNPs and haplotypes in SLC9A3 in whites and SLC4A1 and SLCO4C1 in blacks are significantly associated with preeclampsia.

Haptoglobin phenotype in women with preeclampsia

In pre-eclampsia, poor placentation causes both oxidative and endoplasmic reticulum stress of the placenta. The anti-oxidative protein Haptoglobin has three phenotypes: 1-1, 1-2, and 2-2. Haptoglobin 1-1 is a more potent antioxidant. Our objective was to determine whether haptoglobin 1-1 was less common in women with preeclampsia which is a disease with an oxidatives-stress component, compared to the healthy population. Haptoglobin phenotype was compared in 240 healthy and 120 preeclamptic gravida in a case-control study. Statistical analysis was performed using Chi square test. The prevalence of haptoglobin 1-1 was 13% among healthy women and 6% among preeclamptic women (P=0.049). Secondary analysis was also performed. The prevalence of haptoglobin 1-1 is higher in healthy compared to preeclamptic subjects, a finding compatible with a protective role. Haptoglobin 1-1 might have a protective role in preeclampsia. Further work is needed with more Hp 1-1 subjects before we can conclude on the possible use of Haptoglobin phenotype to assess the risk of preeclampsia.

Marinobufagenin is an upstream modulator of Gadd45a stress signaling in preeclampsia

Preeclampsia (PE) is a hypertensive disorder of pregnancy, in which marinobufagenin (MBG), a circulating cardiotonic steroid, is increased. The Gadd45a stress sensor protein is an upstream modulator of the pathophysiological changes observed in PE. However, the effects of MBG on Gadd45a stress signaling remain unknown. We examined the expression of Gadd45a, the sFlt-1 receptor, and p38, as well as caspase 3 and 8 activities in placental samples from four groups of rats. These were: normal pregnant (NP, n=8); pregnant rats which received weekly injections of desoxycorticosterone acetate and 0.9% saline as their drinking water (PDS, n=9); normal pregnant rats injected with MBG (NPM, n=8); and PDS rats injected with resibufogenin (RBG), an in vivo antagonist of MBG (PDSR, n=8). Utilizing human cytotrophoblast (CTB) cells, we examined the effect of MBG on these stress signaling proteins in vitro. Placental Gadd45a expression, caspase 3 and 8 activities, sFlt-1 concentrations, and sFlt-1 receptor expression were significantly higher in PDS and NPM compared to NP and PDSR rats. Gadd45a protein was significantly upregulated in the CTB cells when MBG was present in concentrations ≥1nM. Treatment with MBG (≥1nM) also significantly arrested cell cycle progression and activated the expression of the Gadd45a-mediated stress signaling proteins. Inhibition of Gadd45a through RNAi-mediation attenuated MBG-induced CTB cell stress signaling. In conclusion, MBG is involved in the alteration in Gadd45a stress signaling both in vivo and in vitro and RBG prevents these changes when administered in vivo.

Marinobufagenin, resibufogenin and preeclampsia

The bufodienolides are cardiac glycosides which have the ability to inhibit the enzyme, Na(+)/K(+) ATPase (sodium potassium adenosine triphosphatase). They are cardiac inotropes, cause vasoconstriction (and, potentially, hypertension) and are natriuretic. Evidence has accrued over time which supports the view that they are mechanistically involved in volume expansion-mediated hypertension. In this communication, the authors summarize data which support the view that the bufodienolides and, in particular, marinobufagenin (MBG) are involved in the pathogenesis of preeclampsia. In a rat model of the syndrome, MBG causes hypertension, proteinuria, intrauterine growth restriction and increased weight gain. All of these phenotypic characteristics are prevented by an antagonist to MBG, resibufogenin (RBG). The "preeclamptic" animals also develop a vascular leak syndrome, resulting in hemoconcentration. Abnormalities in the MAPK (mitogen-activated protein kinase) system play a role in the mechanism by which MBG produces the abnormalities in the pregnant rat. Studies to discover the relevance of these findings to human preeclampsia are currently underway in several laboratories and clinics.

Immune thrombocytopenia in pregnancy

Management of immune thrombocytopenia in pregnancy can be a complex and challenging task and may be complicated by fetal-neonatal thrombocytopenia. Although fetal intracranial hemorrhage is a rare complication of immune thrombocytopenia in pregnancy, invasive studies designed to determine the fetal platelet count before delivery are associated with greater risk than that of fetal intracranial hemorrhage and are discouraged. Moreover, the risk of neonatal bleeding complications does not correlate with the mode of delivery, and cesarean section should be reserved only for obstetric indications.

Association of parathyroid adenoma and pregnancy with preeclampsia

OBJECTIVE

Case reports have described associations between calcium metabolism disturbances and primary hyperparathyroidism with preeclampsia, suggesting parathyroid involvement in preeclampsia etiology. This study examines whether parathyroid adenoma, the main cause of hyperparathyroidism, diagnosed and treated before pregnancy is associated with preeclampsia.

DESIGN

We conducted a register-based study to assess the association between parathyroid adenoma and subsequent preeclampsia.

SETTING

Births among Sweden's general population were studied.

POPULATION

The study population included 52 women with a diagnosis of parathyroid adenoma and 519 without, all of whom had a subsequent singleton pregnancy between 1973 and 1997.

METHODS

We performed a conditional logistic regression investigating the association of parathyroid adenoma with subsequent preeclampsia in the first singleton pregnancy with adjustment for potential confounding factors.

MAIN OUTCOME MEASURE

The main outcome was a diagnosis of preeclampsia that does not include women with prior chronic hypertension. To ensure that treatment of parathyroid adenoma was completed before pregnancy, those with a diagnosis of parathyroid adenoma made less than 2 yr before delivery (and the matched comparison women) were excluded.

RESULTS

Statistically, parathyroid adenoma prior to delivery is significantly (P < 0.001) associated with preeclampsia, producing an adjusted odds ratio of 6.89 (95% confidence interval, 2.30, 20.58).

CONCLUSION

A history of parathyroid adenoma should be viewed as a risk for preeclampsia.

Morphologic Changes of the Uteroplacental Unit in Preeclampsia-Like Syndrome in Rats

OBJECTIVE

Chronic administration of the nitric oxide synthase inhibitor NG-nitro-L-arginine methylester (L-NAME) induces a preeclampsia-like syndrome in rats. This animal study aims to determine whether L-NAME-induced preeclampsia-like syndrome is also associated with morphologic changes in the uteroplacental unit.

METHODS

Mating was induced in 20 adult Sprague-Dawley rats. On day 14, five pregnant rats were randomly assigned to receive L-NAME, whereas six served as controls. Weight, continuous blood pressure, urine volume, urine protein content, litter size, number of resorption sites, placental weight, and weight of pups were documented. Uteroplacental tissue of three L-NAME and three control animals were processed for microscopy using corrosion cast technique.

RESULTS

The L-NAME-treated animals had a significantly smaller litter size (p=.033) and a significantly higher number of resorption sites (p=.021) when compared to controls. In L-NAME-treated rats midlength inner-diameter of maternal arterial channels (p<.001) and cross-sectional area (p<.001) were significantly smaller than were those in controls.

CONCLUSIONS

Chronic administration of L-NAME to pregnant rats is associated with significant morphologic changes of the uteroplacental vasculature. The L-NAME-induced pathologic alterations resulted in decreased litter size and increased number of resorption sites that may be contributed to diminished uteroplacental perfusion.

The Correlation Between Renal Function and Systolic or Diastolic Blood Pressure in Severe Preeclamptic Women

OBJECTIVE

To evaluate the correlation between renal function and systolic or diastolic blood pressure in preeclamptic mothers.

METHODS

In this prospective study from August 1998 to September 2002, 28 women >or= 28 weeks gestation with severe preeclampsia were selected. Meanwhile, 56 normotensive pregnant women without proteinuria or edema served as the control group. Urine was collected for 24 hours for all subjects. The concentration of uric acid, blood urea nitrogen, creatinine, sodium, calcium, and albumin in the 24-hour urine and blood of both groups were examined. Neonatal outcome also was evaluated.

RESULTS

The serum and 24-hour urine concentration of blood urea nitrogen, creatinine, and albumin were significantly higher in severe preeclamptic women. Serum uric acid and urinary albumin/creatinine ratio was significantly higher in severe preeclamptic women compared with that in normotensive mothers and showed positive correlation with systolic or diastolic blood pressure. On the other hand, serum calcium/creatinine ratio was significantly lower in the severe preeclamptic group and negatively correlated to blood pressure. In multiple regressions, systolic or diastolic blood pressure was dependent on serum uric acid, albumin/creatinine, and calcium/creatinine ratios. Fetal birth weight was significantly lower in women with severe preeclampsia and with a lower Apgar score < 7 at 1 minute and 5 minutes and more preterm delivery compared with that in normotensive women.

CONCLUSION

Renal function in women with severe preeclampsia was significantly impaired and highly correlated with systolic or diastolic blood pressure.

Development and Use of Quality of Care Indicators for Obstetric Care in Women with Preeclampsia, Severe Preeclampsia, and Severe Morbidity

OBJECTIVE

To develop indicators for evaluating the quality of care in managing preeclampsia.

METHODS

An expert group helped to develop and validate the following indicators for evaluating quality of care: availability of intensive care; completeness of laboratory tests; appropriateness of drug treatment at admission and before delivery (antihypertensive drugs, anticonvulsants, and dexamethasone); gestational age at which pregnancy should be interrupted; and type of delivery. By using these indicators, it was possible to evaluate the quality of care in 432 patients with preeclampsia.

RESULTS

A significant percentage of patients with preeclampsia and "near misses" received low quality of care, regardless of disease severity.

CONCLUSION

A number of interventions are needed to increase the quality of care to help avert maternal deaths in patients with preeclampsia.

A Rat Model of Preeclampsia

Preeclampsia/eclampsia is a disorder of human pregnancy that continues to exact significant maternal morbidity and mortality and fetal wastage. Therapy of these disorders has not changed in over 50 years and there are no proven preventive measures. We describe a model of the development of a syndrome in the pregnant rat that resembles preeclampsia, which results from the imposition of excessive volume expansion early in gestation. We administered desoxycorticosterone acetate (DOCA) to pregnant animals whose drinking water had been replaced with saline. We compared the results obtained in these animals with those resulting from the study of control, virgin animals, virgin animals receiving DOCA and saline, and normal pregnant (NP) animals. The virgin animals given DOCA and saline did not become hypertensive. The experimental paradigm in the DOCA plus saline pregnant (PDS) animals provides many of the phenotypic characteristics of the human disorder including the development of hypertension, proteinuria, and intrauterine growth restriction. In addition, the mean blood nitrite/nitrate concentration was reduced in the PDS rats compared with their NP counterparts. We propose that this model may prove to be useful in the study of the human condition.

Marinobufagenin causes endothelial cell monolayer hyperpermeability by altering apoptotic signaling

Marinobufagenin (MBG) is an endogenous mammalian cardiotonic steroid that is involved in the inhibition of the sodium pump Na(+)/K(+)-ATPase. Increased plasma levels of MBG have been reported in patients with preeclampsia. MBG increases microvascular barrier permeability in an animal model of preeclampsia. However, the mechanism by which MBG impairs endothelial permeability is unknown. We utilized rat lung microvascular endothelial cells (RLMEC) to examine alterations in MBG-induced monolayer permeability and the effect of MBG on the phosphorylation status of ERK1/2, Jnk, and p38. Apoptosis was evaluated by examining alterations in caspases 3/7, 8, and 9 and annexin-V staining. We also examined the effect of MBG on the endothelial adherens junctions of the RLMEC monolayer. MBG inhibited the proliferation, and increased the monolayer permeability, of RLMEC. These actions of MBG were attenuated by ERK, p38, and pan caspase inhibition. MBG significantly decreased the phosphorylation of ERK1/2 and activated the phosphorylation of Jnk and p38. MBG also significantly increased the expression of caspases 3/7, 8, and 9, indicating the activation of apoptosis. MBG-induced apoptosis signaling was not observed in cells pretreated with a p38 inhibitor. MBG treatment induced the disruption of endothelial cell junctions. This effect was prevented by a pan caspase inhibitor. In conclusion, 1) MBG induced an impairment of RLMEC proliferation; 2) the bufadienolide also caused endothelial hyperpermeability; and 3) these effects of MBG were mediated by the downregulation of ERK1/2, the upregulation of Jnk and p38, by the activation of apoptosis, and by the disruption of endothelial cell junctions.

The HELLP syndrome: clinical issues and management. A Review

BACKGROUND

The HELLP syndrome is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10-20% of cases with severe preeclampsia. The present review highlights occurrence, diagnosis, complications, surveillance, corticosteroid treatment, mode of delivery and risk of recurrence.

METHODS

Clinical reports and reviews published between 2000 and 2008 were screened using Pub Med and Cochrane databases.

RESULTS AND CONCLUSION

About 70% of the cases develop before delivery, the majority between the 27th and 37th gestational weeks; the remainder within 48 hours after delivery. The HELLP syndrome may be complete or incomplete. In the Tennessee Classification System diagnostic criteria for HELLP are haemolysis with increased LDH (> 600 U/L), AST (>or= 70 U/L), and platelets < 100 x 10(9)/L. The Mississippi Triple-class HELLP System further classifies the disorder by the nadir platelet counts. The syndrome is a progressive condition and serious complications are frequent. Conservative treatment (>or= 48 hours) is controversial but may be considered in selected cases < 34 weeks' gestation. Delivery is indicated if the HELLP syndrome occurs after the 34th gestational week or the foetal and/or maternal conditions deteriorate. Vaginal delivery is preferable. If the cervix is unfavourable, it is reasonable to induce cervical ripening and then labour. In gestational ages between 24 and 34 weeks most authors prefer a single course of corticosteroid therapy for foetal lung maturation, either 2 doses of 12 mg betamethasone 24 hours apart or 6 mg or dexamethasone 12 hours apart before delivery. Standard corticosteroid treatment is, however, of uncertain clinical value in the maternal HELLP syndrome. High-dose treatment and repeated doses should be avoided for fear of long-term adverse effects on the foetal brain. Before 34 weeks' gestation, delivery should be performed if the maternal condition worsens or signs of intrauterine foetal distress occur. Blood pressure should be kept below 155/105 mmHg. Close surveillance of the mother should be continued for at least 48 hours after delivery.

Vascular leak in a rat model of preeclampsia

BACKGROUND/AIMS

Preeclampsia is a hypertensive disorder which develops de novo in women during pregnancy. The urinary excretion of the cardiotonic steroid, marinobufagenin (MBG), is increased prior to the development of hypertension. Preeclamptic patients are volume expanded but much of the excess salt and water appears to be located primarily in the interstitial space. Therefore, 'capillary leak' syndrome has been postulated in this disorder.

METHODS

We evaluated the vascular leakage in normal rats following MBG injection and in a rat model of human preeclampsia. We measured the changes in light intensity comparing that in the intravascular to the extravascular space by assessing 'leak' of fluorescein-labeled albumin (FITC-albumin) from mesenteric postcapillary venules.

RESULTS

FITC-albumin extravasation continued to increase in a time-dependent fashion after MBG infusion and was significant (p < 0.05) at 60 min of observation when compared to sham rats. We also observed a significant difference in 'vascular leakage' in preeclamptic rats compared to control non-pregnant and normal pregnant groups starting at 20 min after the FITC-albumin infusion.

CONCLUSION

We propose that MBG is involved in the production of a 'vascular leak' in our rat model of preeclampsia.

High aldosterone-to-renin variants of CYP11B2 and pregnancy outcome

BACKGROUND

Increased aldosterone concentrations and volume expansion of normal pregnancies are hallmarks of normal pregnancies and blunted in pre-eclampsia. Accordingly, we hypothesized an active mineralocorticoid system to protect from pre-eclampsia.

METHODS

In pregnant women (normotensive n = 44; pre-eclamptic n = 48), blood pressure, urinary tetrahydro-aldosterone excretion and activating polymorphisms (SF-1 site and intron 2) of the aldosterone synthase gene (CYP11B2) were determined; 185 non-pregnant normotensive individuals served as control. Amino acid-changing polymorphisms of the DNA- and agonist-binding regions of the mineralocorticoid receptor were evaluated by RT-PCR, SSCP and sequencing.

RESULTS

Urinary tetrahydro-aldosterone excretion was reduced in pre-eclampsia as compared to normal pregnancy (P < 0.05). It inversely correlated with blood pressure (r = 0.99, P < 0.04). Homozygosity for activating CYP11B2 polymorphisms was preferably present in normotensive as compared to pre-eclamptic pregnancies, identified (intron 2, P = 0.005; SF-1 site, P = 0.016). Two mutant haplotypes decreased the risk of developing pre-eclampsia (RR 0.16; CI 0.05-0.54; P < 0.001). In contrast, intron 2 wild type predisposed to pre-eclampsia (P < 0.0015). No functional mineralocorticoid receptor mutant has been observed.

CONCLUSIONS

High aldosterone availability is associated with lower maternal blood pressure. In line with this observation, gain-of-function variants of the CYP11B2 reduce the risk of developing pre-eclampsia. Mutants of the mineralocorticoid receptor cannot explain the frequent syndrome of pre-eclampsia.

Examination of the cellular mechanisms by which marinobufagenin inhibits cytotrophoblast function

Marinobufagenin (MBG) is an endogenous mammalian cardiotonic steroid involved in the inhibition of Na(+)/K(+)-ATPase. Increased plasma levels have been reported in patients with volume expansion-related hypertension. We have recently demonstrated that MBG impairs first trimester cytotrophoblast (CTB) cell proliferation, migration, and invasion, which may play a role in the development of preeclampsia. However, whether apoptosis contributes to altered CTB cell function by MBG remains unknown. Using the human extravillous CTB cell line SGHPL-4, we examined the effect of MBG and a similar Na(+)/K(+)-ATPase inhibitor, ouabain, on the phosphorylation status of Jnk, p38, and Src. Additionally, we measured apoptosis by caspase 9 and 3/7 activity and by annexin-V staining. We also investigated interleukin-6 (IL-6) secretion with or without p38 and Jnk inhibition. MBG significantly increased the phosphorylation of Jnk, p38, and Src and increased the expression of caspase 9 and 3/7 indicating the activation of apoptosis. MBG treatment also stimulated the expression of the early apoptosis marker, annexin-V, which was prevented by Jnk and p38 inhibition. MBG also stimulated the secretion of IL-6, which was attenuated by p38 inhibition. Ouabain had similar effects to those of MBG, suggesting that the apoptotic effects on CTB cells may be mediated by inhibition of Na(+)/K(+)-ATPase. In conclusion, the MBG-induced impairment of CTB function occurs via activation of Jnk, p38, and Src leading to increased apoptosis and IL-6 secretion. These observations may have clinical applicability with respect to the therapy of preeclampsia.