Recent advances in the understanding of the pathophysiology of preeclampsia

Placental hypoxia inducible factor -1α & CHOP immuno-histochemical expression relative to maternal circulatory syncytiotrophoblast micro-vesicles in preeclamptic and normotensive pregnancies

OBJECTIVES

Preeclampsia (PE) occurs as a result placental hypoxia-induced oxidative and endoplasmic reticulum stress, and is associated with the activation of hypoxia inducible factor-1α (HIF-1α) and apoptotic CHOP pathways with the consequential shedding of syncytiotrophoblast microvesicles which may be central in mediating the maternal systemic immune response. The aim of this study was to immune-localise and morphometrically analyse CHOP and HIF-1α within the placenta of normotensive and pre-eclamptic pregnancies and concomitantly quantify syncytiotrophoblast released microvesicles in maternal circulation.

STUDY DESIGN

Placental tissue and plasma were obtained from normotensive and pre-eclamptic pregnant women. The expression of CHOP and HIF-1α was analysed using immunohistochemistry. Isolation and size distribution of the circulating maternal microvesicles was determined using nanoparticle tracking analysis. The concentration of syncytiotrophoblast microvesicles was determined using the placental alkaline phosphatase ELISA.

RESULTS

This study demonstrates a significant increase in immunohistochemical expression of HIF-1 α and CHOP in preeclampsia compared to the normotensive women (p<0.05). In keeping with this, a significant increase in the mean syncytiotrophoblast microvesicles concentration was observed in PE, compared to normotensives (p<0.05). A positive correlation between placental expression of CHOP and HIF-1α and STBMs was obtained.

CONCLUSION

This study demonstrates increased placental expression of HIF-1α and CHOP in preeclampsia compared to normotensive pregnancies which correlate to their increased syncytiotrophoblast microvesicles concentration in maternal circulation. These findings indicate that placental hypoxia and ER stress are interrelated contributory factors to the pathogenesis of PE and the consequential release of placental derived debris into the maternal circulation.

Intrauterine growth restriction and placental gene expression in severe preeclampsia, comparing early-onset and late-onset forms

OBJECTIVE

To evaluate placental gene expression in severe early- or late-onset preeclampsia with intrauterine growth restriction compared to controls.

STUDY DESIGN

Chorionic villus sampling was conducted after cesarean section from the placentas of five women with early- or late-onset severe preeclampsia and five controls for each preeclampsia group. Microarray analysis was performed to identify gene expression differences between the groups.

RESULTS

Pathway analysis showed over-representation of gene ontology (GO) biological process terms related to inflammatory and immune response pathways, platelet development, vascular development, female pregnancy and reproduction in early-onset preeclampsia. Pathways related to immunity, complement and coagulation cascade were overrepresented in the hypergeometric test for the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Ten genes (ABI3BP, C7, HLA-G, IL2RB, KRBOX1, LRRC15, METTL7B, MPP5, RFLNB and SLC20A) had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to early controls. There were 362 genes that had a ≥±1 fold expression difference in severe early-onset preeclampsia group compared to late-onset preeclampsia group including ABI3BP, C7, HLA-G and IL2RB.

CONCLUSION

There are significant differences in placental gene expression between severe early- and late-onset preeclampsia when both are associated with intrauterine growth restriction. ABI3BP, C7, HLA-G and IL2RB might contribute to the development of early form of severe preeclampsia.

Increased expression of NLRP3 inflammasome in placentas from pregnant women with severe preeclampsia

Preeclampsia is a pregnancy disorder characterized by imbalance between pro- and anti-inflammatory cytokines associated with high plasma levels of uric acid and Interleukin-1 beta (IL-1β). The inflammasome is a protein complex that mediates innate immune responses via caspase-1 activation promoting secretion of IL-1β and IL-18 in their active forms, and also release of the high-mobility group box 1 protein (HMGB1). As the placenta seems to play an important role in the pathogenesis of PE, the present study investigated the expression of genes and proteins related to the inflammasome in placentas from pregnant women with severe preeclampsia. Placental tissue was collected from 20 normotensive pregnant women and 20 preeclamptic women, and inflammasome components, NLRP3 (NOD-like receptor family, pyrin domain-containing protein 3), caspase-1, IL-1β and IL-18, as well as tumor necrosis factor-alpha (TNF-α) and HMGB1 were evaluated by immunohistochemistry, enzyme-linked immunosorbent assay (ELISA) and also quantified by reverse transcription-qPCR (RT-qPCR). Compared with normotensive pregnant women, placenta from women with PE showed a significant increase in NLRP3, caspase-1, IL-1β, TNF-α and HMGB1 mRNA. Immunohistochemical staining of NLRP3, caspase-1, IL-1β and TNF-α in placental villi, as well as the levels of caspase-1, IL-1β, TNF-α and HMGB1 in placental homogenate were significantly higher in the preeclamptic group than in the normotensive group. However, mRNA expression of IL-18 and its protein concentrations were lower in placentas from preeclamptic women. The results suggest that placentas from pregnant women with preeclampsia show higher expression of NLRP3 inflammasome, which may be involved in the exaggerated inflammatory state in preeclampsia.

Effects of Intrauterine Growth Restriction and Female Sex on Future Blood Pressure and Cardiovascular Disease

PURPOSE OF THE REVIEW

It is well-established that the age-related increase in blood pressure is augmented after menopause. Yet, the prevalence of hypertension is enhanced in low birth weight women relative to normal birth weight counterparts by 60 years of age suggesting that adverse influences during fetal life heighten cardiovascular risk in later life.

RECENT FINDINGS

A changing hormonal milieu may contribute to increased cardiovascular risk that occurs after the menopausal transition. Low birth weight is associated with early age at menopause. A recent study indicates that a shift towards testosterone excess following early reproductive senescence may contribute to the etiology of age-dependent increases in blood pressure in a rodent model of low birth weight. This review will highlight current findings related to postmenopausal hypertension and discuss potential mechanisms that may contribute to the enhanced cardiovascular risk that develops with age in low birth weight women.

Myeloperoxidase in Hypertensive Disorders of Pregnancy and Its Relation With Nitric Oxide

Elevated levels of myeloperoxidase have been demonstrated in women with preeclampsia where it may contribute to endothelial dysfunction mediated, in part, by nitric oxide impairment. In this study, we investigated myeloperoxidase in hypertensive disorders of pregnancy and its contribution to the impairment of the vasodilator nitric oxide. We found higher levels of myeloperoxidase in supernatant from human umbilical vein endothelial cells cultures incubated with plasma from preeclampsia group compared with healthy pregnant women. Further, we measured plasma concentration and activity of myeloperoxidase in 219 healthy pregnant women, 130 gestational hypertension (on antihypertensive therapy or not), and 143 preeclampsia patients (on antihypertensive therapy or not). We found that patients with preeclampsia and gestational hypertension without antihypertensive treatment showed higher levels and activity of this enzyme, respectively. Moreover, the inhibition of myeloperoxidase activity in vitro improved nitric oxide bioavailability. Our results indicate a higher cardiovascular risk in pregnant women with hypertensive disorders, and that active myeloperoxidase may play a role in endothelial dysfunction in these conditions by impairment of nitric oxide availability. Besides, the use of antihypertensive drugs seems to decrease enzyme levels suggesting a new protective feature for these drugs.

Pharmacogenetics in the treatment of pre-eclampsia: current findings, challenges and perspectives

Pre-eclampsia (PE) is defined as pregnancy-induced hypertension and proteinuria, and is a major cause of maternal and perinatal morbidity and mortality. A large subgroup of pregnant women with PE is nonresponsive to antihypertensive drugs, including methyldopa, nifedipine and hydralazine. Pharmacogenomics may help to guide the individualized therapy for this nonresponsive subgroup. However, just a few pharmacogenetic studies examined the effects of genetic polymorphisms on response to antihypertensive drugs in PE, and the criteria of responsiveness used to define responsive or nonresponsive subgroups to antihypertensive therapy should be replicated by others. We review these gene–drugs interactions, novel approaches to pharmacogenomics research and potential novel drugs for PE therapy. Finally, we discuss the challenges and perspectives of pharmacogenetics in the treatment of PE.

Up-regulation of CD81 inhibits cytotrophoblast invasion and mediates maternal endothelial cell dysfunction in preeclampsia

Preeclampsia (PE) is initiated by abnormal placentation in the early stages of pregnancy, followed by systemic activation of endothelial cells of the maternal small arterioles in the late second or third trimester (TM) of pregnancy. During normal pregnancy, placental cytotrophoblasts (CTBs) invade the maternal uterine wall and spiral arteries, whereas this process is interrupted in PE. However, it is not known how the malformed placenta triggers maternal endothelial crisis and the associated manifestations. Here, we have focused on the association of CD81 with PE. CD81, a member of the tetraspanin superfamily, plays significant roles in cell growth, adhesion, and motility. The function of CD81 in human placentation and its association with pregnancy complications are currently unknown. In the present study, we have demonstrated that CD81 was preferentially expressed in normal first TM placentas and progressively down-regulated with gestation advance. In patients with early-onset severe PE (sPE), CD81 expression was significantly up-regulated in syncytiotrophoblasts (STBs), CTBs and the cells in the villous core. In addition, high levels of CD81 were observed in the maternal sera of patients with sPE. Overexpressing CD81 in CTBs significantly decreased CTB invasion, and culturing primary human umbilical vein endothelial cells (HUVECs) in the presence of a high dose of exogenous CD81 resulted in interrupted angiogenesis and endothelial cell activation in vitro. Importantly, the phenotype of human PE was mimicked in the CD81-induced rat model.

Do racial differences exist in the association between pregnancy-induced hypertension and breast cancer risk?

BACKGROUND

Previous studies investigating the relationship between pregnancy-induced hypertension (PIH) and breast cancer risk have yielded inconsistent results. Unlike numerous Western studies, studies have reported that PIH may be a risk factor for breast cancer in Western Asian women. To confirm these results, we designed a retrospective population-based cohort study to assess the relationship between PIH and subsequent risk for breast cancer in Taiwan.

METHODS

Patients with newly diagnosed PIH were selected from the Taiwan National Health Insurance Research Database (NHIRD), and a 1:4 matched cohort of women without PIH based on age and the year of delivery was randomly selected from the same database as the comparison group. The incidence of new-onset breast cancer was assessed in both cohorts.

RESULTS

Among the 23.3 million individuals registered in the NHIRD, 26,638 patients with PIH and 106,552 matched controls were identified. The incidence rate of breast cancer was higher in patients with PIH than in the matched controls (incidence rate ratio = 1.09, 95% confidence interval [CI] = 1.09-1.10, p < 0.0001). However, the Kaplan-Meier analysis revealed a similar cumulative incidence rate of breast cancer between the PIH and comparison cohorts (log-rank p = 0.4303). Moreover, results from a multivariate analysis indicated that PIH was not a statistically significant independent risk factor for breast cancer (adjusted hazard ratio = 1.10, 95% CI = 0.87-1.39, p = 0.4247).

CONCLUSIONS

The present study demonstrated no significant temporal relationship between PIH and risk for subsequent breast cancer in Eastern Asian women.

Relationship between hypoxia and downstream pathogenic pathways in preeclampsia

Defects in angiogenesis and mitochondrial function in the placenta contribute to the pathogenesis of preeclampsia; however upstream regulators of these pathways are not known. It has been argued that placental hypoxia secondary to abnormal spiral artery remodeling may play a causal role in the angiogenic and mitochondrial abnormalities noted in preeclampsia. The aim of this study was to evaluate the relationship between hypoxia-inducible factor-1α (HIF-1α) ¸ a surrogate of hypoxia, and soluble fms-tyrosine kinase 1 (sFlt1), a circulating anti-angiogenic factor, and microRNA 210 (miR-210), a microRNA that regulates mitochondrial function, in human placentas from preeclamptic and non-hypertensive pregnancies. We first confirmed a 2.5-fold upregulation of HIF-1α protein in placentas from preeclampsia when compared to non-hypertensive controls. Consistent with prior studies, we also observed a 10-fold upregulated sFlt1 mRNA and 2-fold upregulated miR-210 in preeclamptic tissue. Interestingly, while sFlt1 mRNA correlated with miR-210 in preeclampsia (R² = 0.77, p = 0.0004), there were no significant correlations between these molecules and HIF1α expression. We conclude that non-hypoxia pathways may be involved in the abnormal angiogenic and metabolic alterations noted in preeclampsia.

Metabolic abnormalities and obesity's impact on the risk for developing preeclampsia

Preeclampsia (PE), a hypertensive disorder of pregnancy, is increasing as a major contributor to perinatal and long-term morbidity of mother and offspring. PE is thought to originate from ischemic insults in the placenta driving the release of prohypertensive anti-angiogenic [soluble fms-like tyrosine kinase-1 (sFlt-1)] and proinflammatory [tumor necrosis factor-α (TNF-α)] factors into the maternal circulation. Whereas the increased incidence of PE is hypothesized to be largely due to the obesity pandemic, the mechanisms whereby obesity increases this risk are unknown. The maternal endothelium is targeted by placental and adipose tissue-derived factors like sFlt-1 and TNF-α that promote hypertension during pregnancy, resulting in vascular dysfunction and hypertension. Interestingly, not all obese pregnant women develop PE. Data suggest that obese pregnant women with the greatest metabolic abnormalities have the highest incidence of PE. Identifying obesity-related mechanisms driving hypertension in some obese pregnant women and pathways that protect normotensive obese pregnant women, may uncover novel protocols to treat PE. Metabolic abnormalities, such as increased circulating leptin, glucose, insulin, and lipids, are likely to increase the risk for PE in obese women. It is not only important to understand whether each of these metabolic factors contribute to the increased risk for PE in obesity, but also their cumulative effects. This is particularly relevant to obese pregnant women with gestational diabetes mellitus (GDM) where all of these factors are increased and the risk for PE is highest. It is speculated that these factors potentiate the anti-angiogenic and proinflammatory mechanisms of placental ischemia-induced vascular dysfunction thereby contributing to the increasing incidence of PE.

Towards biomarker-based tests that can facilitate decisions about prevention and management of preeclampsia in low-resource settings

In recent years, an increasing amount of literature is emerging on candidate urine and blood-based biomarkers associated with incidence and severity of preeclampsia (PE) in pregnant women. While enthusiasm on the usefulness of several of these markers in predicting PE is evolving, essentially all work so far has focused on the needs of high-resource settings and high-income countries, resulting primarily in multi-parameter laboratory assays based on proteomic and metabolomics analysis techniques. These highly complex methods, however, require laboratory capabilities that are rarely available or affordable in low-resource settings (LRS). The importance of quantifying maternal and perinatal risks and identifying which pregnancies can be safely prolonged is also much greater in LRS, where intensive care facilities that can rapidly respond to PE-related health threats for women and infants are limited. For these reasons, simple, low cost, sensitive, and specific point-of-care (POC) tests are needed that can be performed by antenatal health care providers in LRS and that can facilitate decisions about detection and management of PE. Our study aims to provide a comprehensive systematic review of current and emerging blood and urine biomarkers for PE, not only on the basis of their clinical performance, but also of their suitability to be used in LRS-compatible test formats, such as lateral flow and other variants of POC rapid assays.

Diagnosis of Acute Neurologic Emergencies in Pregnant and Postpartum Women

Acute neurologic symptoms in pregnant and postpartum women may be caused by exacerbation of a preexisting neurologic condition, the initial presentation of a non-pregnancy-related problem, or a new neurologic problem. Pregnant and postpartum patients with headache and neurologic symptoms are often diagnosed with preeclampsia or eclampsia; however, other etiologies must also be considered. A team approach with close communication between emergency physicians, neurologists, maternal-fetal medicine specialists, and radiologists is the key to obtaining best outcomes. This article reviews the clinical features and differential diagnosis of acute serious neurologic conditions in pregnancy and the puerperium, focusing on diagnosis.

Assessment, Management, and Health Implications of Early-Onset Preeclampsia

Early-onset preeclampsia is a serious condition of pregnancy with the potential for adverse maternal and fetal health outcomes. A strong body of evidence supports the need for postpartum follow-up and health counseling, because these women and their offspring are at risk for future cardiovascular disease; nurses play a key role in this education. An understanding of the diagnosis, risk screening for, pathogenesis, and management of severe preeclampsia and its sequelae, such as intrauterine growth restriction and pulmonary edema, enables nurses to develop a comprehensive plan of care that will support women and their families through this challenging and dynamic complication of pregnancy.

Placental origins of adverse pregnancy outcomes: potential molecular targets: an Executive Workshop Summary of the Eunice Kennedy Shriver National Institute of Child Health and Human Development

Although much progress is being made in understanding the molecular pathways in the placenta that are involved in the pathophysiology of pregnancy-related disorders, a significant gap exists in the utilization of this information for the development of new drug therapies to improve pregnancy outcome. On March 5-6, 2015, the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health sponsored a 2-day workshop titled Placental Origins of Adverse Pregnancy Outcomes: Potential Molecular Targets to begin to address this gap. Particular emphasis was given to the identification of important molecular pathways that could serve as drug targets and the advantages and disadvantages of targeting these particular pathways. This article is a summary of the proceedings of that workshop. A broad number of topics were covered that ranged from basic placental biology to clinical trials. This included research in the basic biology of placentation, such as trophoblast migration and spiral artery remodeling, and trophoblast sensing and response to infectious and noninfectious agents. Research findings in these areas will be critical for the formulation of the development of future treatments and the development of therapies for the prevention of a number of pregnancy disorders of placental origin that include preeclampsia, fetal growth restriction, and uterine inflammation. Research was also presented that summarized ongoing clinical efforts in the United States and in Europe that has tested novel interventions for preeclampsia and fetal growth restriction, including agents such as oral arginine supplementation, sildenafil, pravastatin, gene therapy with virally delivered vascular endothelial growth factor, and oxygen supplementation therapy. Strategies were also proposed to improve fetal growth by the enhancement of nutrient transport to the fetus by modulation of their placental transporters and the targeting of placental mitochondrial dysfunction and oxidative stress to improve placental health. The roles of microRNAs and placental-derived exosomes, as well as messenger RNAs, were also discussed in the context of their use for diagnostics and as drug targets. The workshop discussed the aspect of safety and pharmacokinetic profiles of potential existing and new therapeutics that will need to be determined, especially in the context of the unique pharmacokinetic properties of pregnancy and the hurdles and pitfalls of the translation of research findings into practice. The workshop also discussed novel methods of drug delivery and targeting during pregnancy with the use of macromolecular carriers, such as nanoparticles and biopolymers, to minimize placental drug transfer and hence fetal drug exposure. In closing, a major theme that developed from the workshop was that the scientific community must change their thinking of the pregnant woman and her fetus as a vulnerable patient population for which drug development should be avoided, but rather be thought of as a deprived population in need of more effective therapeutic interventions.

Increased risk of systemic lupus erythematosus in pregnancy-induced hypertension: A nationwide population-based retrospective cohort study

Dysregulation of the immune system plays a role in the pathogenesis of both, pregnancy-induced hypertension (PIH) and systemic lupus erythematosus (SLE). It is well known that SLE predisposes to be complicated with PIH. However, few studies have attempted to investigate whether PIH increased subsequent SLE risk.The objectives of this study were to assess the association between PIH and subsequent SLE risk and identify predictive risk factors.Patients with newly diagnosed PIH were selected from the Taiwan National Health Insurance Research Database (NHIRD) and compared with a matched cohort without PIH based on age and the year of delivery. The incidence of new-onset SLE was evaluated in both cohorts. The overall observational period was from January 1, 2000 to December 31, 2013.Among the 23.3 million individuals registered in the NHIRD, 29,091 patients with PIH and 116,364 matched controls were identified. The incidence of SLE was higher among patients with PIH than in the matched controls (incidence rate ratio [IRR] = 4.02, 95% confidence interval [CI] 3.98-4.05, P < 0.0001). The IRR for subsequent SLE development remained significantly higher in all stratifications during the follow-up years. The multivariate Cox regression model was performed and the results showed that PIH may be an independent risk factors for the development of subsequent SLE (hazard ratio [HR] = 2.87, 95% CI 2.07-3.98, P < 0.0001). Moreover, multivariate Cox regression model was used again among the PIH cohort only in order to identify the possible risk factors for subsequent SLE in the population with PIH.Patients with PIH may have higher risk of developing newly diagnosed SLE than those without PIH. In addition, among individuals who have experienced PIH, those younger than 30 years, having experienced preeclampsia/eclampsia, single parity, preterm birth, or chronic kidney disease, may display an increased subsequent risk of SLE.

Endothelial dysfunction and arterial stiffness in pre-eclampsia demonstrated by the EndoPAT method

OBJECTIVES

The EndoPAT method has been used as a non-invasive method for assessing endothelial function in several non-pregnant populations. We investigated its possible use in assessing endothelial dysfunction in pre-eclampsia.

METHODS

Two hundred and fifteen participants were recruited and grouped as pre-eclamptic cases (105) and normotensive controls (110). Endothelial function and arterial stiffness were measured as reactive hyperaemia index and augmentation index, respectively, using the EndoPAT 2000 machine.

RESULTS

The reactive hyperaemia index was significantly lower in the pre-eclamptic group compared to the normotensive group (p < 0.05). Augmentation index on the other hand was significantly higher in the pre-eclamptic group compared to the normotensive group (p < 0.0001).

CONCLUSION

The EndoPAT method demonstrates endothelial dysfunction and arterial stiffness in pre-eclampsia.

Increased Risk of Intracranial Hemorrhage in Patients With Pregnancy-Induced Hypertension: A Nationwide Population-Based Retrospective Cohort Study

Pregnancy-induced hypertension (PIH) may be a major predictor of pregnancy-associated intracranial hemorrhage (ICH). However, the relationship between PIH and long-term ICH risk is unknown.The objective of the study was to determine the association between PIH and ICH and to identify the predictive risk factors.Patients with newly diagnosed PIH were recruited from the Taiwan National Health Insurance Research Database. PIH patients were divided into gestational hypertension (GH) and preeclampsia groups. The 2 groups were separately compared with matched cohorts of patients without PIH based on age and date of delivery. The occurrence of ICH was evaluated in both cohorts. The overall observational period was from January 1, 2000 to December 31, 2013.Among the 23.3 million individuals registered in the National Health Insurance Research Database, 28,346 PIH patients, including 7390 with GH and 20,956 with preeclampsia, were identified. The incidences of ICH were increased in both groups (incidence rate ratio [IRR] = 3.72 in the GH group, 95% confidence interval [CI] 3.63-3.81, P < 0.0001 and IRR = 8.21 in the preeclampsia group, 95% CI 8.12-8.31, P < 0.0001, respectively). In addition, according to the results of stratification of follow-up years, both groups were associated with a highest risk of ICH at 1 to 5 years of follow-up (IRR = 11.99, 95% CI 11.16-12.88, P < 0.0001 and IRR = 21.83, 95% CI 21.24-22.44, P < 0.0001, respectively). After adjusting for age, parity, severity of PIH, number of PIH occurrences, gestational age, and comorbidities in the multivariate survival analysis using Cox regression model, age ≥30 years (hazard ratio [HR] 1.99, 95% CI 1.27-3.10, P = 0.0026), patients with preeclampsia (HR 2.18, 95% CI 1.22-3.90, P = 0.0089), multiple PIH occurrences (HR 4.08, 95% CI 1.85-9.01, P = 0.0005), hypertension (HR 4.51, 95% CI 1.89-10.74, P = 0.0007), and obesity (HR 7.21, 95% CI 1.58-32.84, P = 0.0107) were independent risk factors for the development of ICH among patients with PIH.Patients with PIH, especially those with older age, preeclampsia, and multiple PIH occurrences, may have an increased risk of developing ICH later in life.

Brain lesions in eclampsia: A series of 39 cases admitted in an Intensive Care Unit

The aim of this study was to identify the encephalic lesions in the eclampsia occurrences. Within a period of 18 months, computed tomography (CT) of the brain was performed in all patients admitted in intensive care for eclampsia. These CTs were analyzed and intracerebral lesions were identified. Thirty-nine patients were included. We noted 10 cases of ischemic stroke, 9 cases of cerebral edema, and 3 cases of hemorrhagic stroke and subarachnoid hemorrhage. The CT scan came back to normal in 20 eclamptic patients. Overall, delays in obstetric and intensive care and time of completion of the CT were long. CT has allowed highlighting in patients with eclampsia varied intracerebral lesions. The early performance of the CT is therefore essential for a better support of patients.

Increased secretory sphingomyelinase activity in the first trimester of pregnancy in women later developing preeclampsia: a nested case-control study

The pathogenic basis of abnormal placentation and dysfunction in preeclampsia (PE) is highly complex and incompletely understood. Secretory sphyngomyelinase activity (S-ASM) was analyzed in plasma samples from 158 pregnant women developing PE and 112 healthy pregnant controls. Serum PlGF, sFlt-1, s-Endoglin and sVCAM were measured. Results showed S-ASM activity to be higher in women who later developed PE than in those with uncomplicated pregnancies (40.6% and 28.8% higher in the late- and early-onset groups, respectively). Plasma S-ASM activity correlated significantly with circulating markers of endothelial damage in the late-PE group (endoglin and sVCAM-1), with plasma cholesterol and total lipid levels. However, these significant associations were not observed in the early-PE or control groups. This work provides the first evidence of significantly elevated circulating S-ASM activity in the first trimester of pregnancy in women who go on to develop PE; thus, it may be deduced that the circulating form of ASM is biologically active in PE and could contribute to promoting endothelial dysfunction and cardiovascular programming. Plasma S-ASM measurement may have clinical relevance as a further potential biomarker contributing to the earliest identification of women at risk of developing preeclampsia.

Prospective study of the hemodynamic behavior of ophthalmic arteries in postpartum preeclamptic women: A doppler evaluation

The aim of this study was to evaluate the hemodynamic behavior of the ophthalmic artery by means of the Doppler ultrasound, in postpartum preeclamptic women. It was an observational prospective study with 44 postpartum preeclamptic women (group 1) and 49 postpartum normal women with normal blood pressure and with no previous illnesses known (group 2). All the pregnant women had a Doppler ultrasound exam of the ophthalmic artery in the immediate puerperium, that is, 10 days for the delivery (time 1). Group 1 was then followed prospectively, 26 patients of which returned to the last test in the remote puerperium in 45 days (time 2) and 29 patients returned to the last test in the remote puerperium in 90 days (time 3). All these women had preeclampsia before the delivery. The resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV), end diastolic flow velocity (EDV), second peak of systolic velocity (P2), and the peak ratio (PR) were calculated. The data obtained are expressed in average and standard deviation, by using the Lilliefors test for normality. The average of the Doppler indexes in groups 1 and 2 was compared by means of test t of the student. Group 1 was analyzed separately, comparing the three times, using the test of ANOVA for repetitive measures and Tukey post-hoc range test. In the "Results" section, the statically meaningful differences in RI, PI, P2, RPV, and EDV (p < 0.0001, p < 0.0001, p < 0.0009, p < 0.0001, p < 0.0028) were found in the immediate puerperium of group 1 in relation to group 2, indicating the persistence of hyperperfusion and orbital vasodilatation in the immediate postpartum period in patients who had complicated pregnancies previously due to preeclampsia. In the evolutionary analysis of group 1, comparing the Doppler indexes between the immediate and late puerperium, statistically relevant differences between the rates of RI, P2, and PR (p < 0,01) were observed, showing a raise of RI and reduction of P2 and PR, and also a tendency of normalization of these rates in the late puerperium. When the same indexes were compared (PI, P2, and PR) now in times 2 and 3, the remote, and late puerperium, respectively, there were no significant differences, indicating the stabilization of these indexes since the 45th day of the puerperium. Within 90 days, RI, PI, and PR are not stabilized yet in relation to the control, even though there is a tendency of these indexes to reach the control. In conclusion, there was persistence of signs of vasodilatation and hyperperfusion of the orbital territory, represented by Doppler of the ophthalmic artery in the immediate puerperium of preeclamptic women. A tendency of normalization of the orbital hemodynamic standard in the pregnant women from the period of the late puerperium was observed, but there was no complete normalization of the vascular pattern on the remote postpartum.

Glucocorticoid exposure in early placentation induces preeclampsia in rats via interfering trophoblast development

In pregnancy, placenta can be exposed to glucocorticoids (GCs) via several ways, which may disturb placentation and adversely affect pregnancy. Preeclampsia (PE) is thought to be attributed, in part, to impaired trophoblast development. The purpose of the present study was to confirm that GC exposure in early placentation could lead to PE in rats, with the mechanisms involving dysregulated trophoblast development. In the study, pregnant rats were administered with 2.5mg/kg Dex subcutaneously once per day from gestational day 7 to 13. Maternal systolic blood pressure and urinary albumin were increased, while both fetus and placenta were restricted after GC exposure relative to the control group. GC exposure also contributed to placental abnormalities and renal impairment. Moreover, placental oxidative damage was increased along with placental hypoxia-inducible factor 1-alpha (HIF1A) overexpression after GC treatment. Mechanically, GC induced PE in rat partially through inhibiting trophoblast proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), which involved phospho-extracellular signal regulated kinase (p-ERK) downregulation. Furthermore, GC receptor was required for the inhibition of GC on trophoblast proliferation, migration, invasion and EMT in vitro. These findings suggest that GC exposure in early placentation could contribute to PE in pregnant rats, with the mechanisms involving inhibition of trophoblast proliferation, migration, invasion and EMT by GC.

Immune Mechanisms Linking Obesity and Preeclampsia

Preeclampsia (PE) is characterized by hypertension occurring after the twentieth week of pregnancy. It is a significant contributor to maternal and perinatal morbidity and mortality in developing countries and its pervasiveness is increasing within developed countries including the USA. However, the mechanisms mediating the pathogenesis of this maternal disorder and its rising prevalence are far from clear. A major theory with strong experimental evidence is that placental ischemia, resulting from inappropriate remodeling and widening of the maternal spiral arteries, stimulates the release of soluble factors from the ischemic placenta causing maternal endothelial dysfunction and hypertension. Aberrant maternal immune responses and inflammation have been implicated in each of these stages in the cascade leading to PE. Regarding the increased prevalence of this disease, it is becoming increasingly evident from epidemiological data that obesity, which is a state of chronic inflammation in itself, increases the risk for PE. Although the specific mechanisms whereby obesity increases the rate of PE are unclear, there are strong candidates including activated macrophages and natural killer cells within the uterus and placenta and activation in the periphery of T helper cells producing cytokines including TNF-α, IL-6 and IL-17 and the anti-angiogenic factor sFlt-1 and B cells producing the agonistic autoantibodies to the angiotensin type 1 receptor (AT1-aa). This review will focus on the immune mechanisms that have been implicated in the pathogenesis of hypertension in PE with an emphasis on the potential importance of inflammatory factors in the increased risk of developing PE in obese pregnancies.

Increased risk for the development of preeclampsia in obese pregnancies: weighing in on the mechanisms

Preeclampsia (PE) is a pregnancy-specific disorder typically presenting as new-onset hypertension and proteinuria. While numerous epidemiological studies have demonstrated that obesity increases the risk of PE, the mechanisms have yet to be fully elucidated. Growing evidence from animal and human studies implicate placental ischemia in the etiology of this maternal syndrome. It is thought that placental ischemia is brought about by dysfunctional cytotrophoblast migration and invasion into the uterus and subsequent lack of spiral arteriole widening and placental perfusion. Placental ischemia/hypoxia stimulates the release of soluble placental factors into the maternal circulation where they cause endothelial dysfunction, particularly in the kidney, to elicit the clinical manifestations of PE. The most recognized of these factors are the anti-angiogenic sFlt-1 and pro-inflammatory TNF-α and AT1-AA, which promote endothelial dysfunction by reducing levels of the provasodilator nitric oxide and stimulating production of the potent vasoconstrictor endothelin-1 and reactive oxygen species. We hypothesize that obesity-related metabolic factors increase the risk for developing PE by impacting various stages in the pathogenesis of PE, namely, 1) cytotrophoblast migration and placental ischemia; 2) release of soluble placental factors into the maternal circulation; and 3) maternal endothelial and vascular dysfunction. This review will summarize the current experimental evidence supporting the concept that obesity and metabolic factors like lipids, insulin, glucose, and leptin affect placental function and increase the risk for developing hypertension in pregnancy by reducing placental perfusion; enhancing placental release of soluble factors; and by increasing the sensitivity of the maternal vasculature to placental ischemia-induced soluble factors.

Combined Screening for Early Detection of Pre-Eclampsia

Although the precise pathophysiology of pre-eclampsia remains unknown, this condition continues to be a major cause of maternal and fetal mortality. Early prediction of pre-eclampsia would allow for timely initiation of preventive therapy. A combination of biophysical and biochemical markers are superior to other tests for early prediction of the development of pre-eclampsia. Apart from the use of parameters in first-trimester aneuploidy screening, cell-free fetal DNA quantification is emerging as a promising marker for prediction of pre-eclampsia. This article reviews the current research of the most important strategies for prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters, and biomarkers.

Association between an abnormal cerebroplacental ratio and the development of severe pre-eclampsia

OBJECTIVE

To study the association between the cerebroplacental ratio (CPR) and the development of pre-eclampsia.

STUDY DESIGN

Three study groups were determined: Group 1-normal umbilical artery (UA; referent), Group 2-abnormal UA and normal CPR and Group 3-abnormal UA and an abnormal CPR. The primary outcome was the development of severe pre-eclampsia.

RESULTS

We included 270 women. Women in Group 3 had significantly elevated rates of severe pre-eclampsia versus those in Group 1 and Group 2, 52.5% versus 5.1% and 15.4%, respectively, (P<0.01), adjusted odds ratio 4.14 (95% confidence interval, 2.59 to 6.61). Kaplan-Meier analysis revealed earlier delivery in women with pre-eclampsia in Group 3 versus Group 1, Cox-Mantel hazard ratio 2.39 (1.17 to 4.88), log rank P=0.01.

CONCLUSION

An abnormal CPR is associated with a higher rate severe pre-eclampsia with delivery at earlier gestational ages than with a normal UA or an abnormal UA, but normal CPR.

Sofalcone upregulates the nuclear factor (erythroid-derived 2)-like 2/heme oxygenase-1 pathway, reduces soluble fms-like tyrosine kinase-1, and quenches endothelial dysfunction: potential therapeutic for preeclampsia

Preeclampsia is a severe complication of pregnancy, characterized by hypertension, oxidative stress, and severe endothelial dysfunction. Antiangiogenic factors, soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin, play key pathophysiological roles in preeclampsia. Heme oxygenase-1 (HO-1) is a cytoprotective, antioxidant enzyme reported to be downregulated in preeclampsia. Studies propose that inducing HO-1 may also decrease sFlt-1 production. Sofalcone, a gastric antiulcer agent in clinical use, is known to induce HO-1 in gastric epithelium. We aimed to investigate whether sofalcone induces HO-1 and reduces sFlt-1 release from primary human placental and endothelial cells and blocks endothelial dysfunction in vitro. We isolated human trophoblasts and endothelial cells (human umbilical vein endothelial cells) and also used uterine microvascular cells. We investigated the effects of sofalcone on (1) HO-1 production, (2) activation of the nuclear factor (erythroid-derived 2)-like 2 pathway, (3) sFlt-1 and soluble endoglin release, (4) tumor necrosis factor α-induced monocyte adhesion and vascular cell adhesion molecule upregulation, and (5) endothelial tubule formation. Sofalcone potently increased HO-1 mRNA and protein in both primary trophoblasts and human umbilical vein endothelial cells. Furthermore, sofalcone treatment caused nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 and transactivation of other nuclear factor (erythroid-derived 2)-like 2 responsive genes (NQO1, TXN, and GCLC). Importantly, sofalcone significantly decreased the secretion of sFlt-1 from primary human trophoblasts. Sofalcone potently suppressed endothelial dysfunction in 2 in vitro models, blocking tumor necrosis factor α-induced monocyte adhesion and vascular cell adhesion molecule 1 expression in human umbilical vein endothelial cells. These results indicate that in primary human tissues, sofalcone can potently activate antioxidant nuclear factor (erythroid-derived 2)-like 2/HO-1 pathway, decrease sFlt-1 production, and ameliorate endothelial dysfunction. We propose that sofalcone is a novel therapeutic candidate for preeclampsia.

Synergistic effect of gestational hypertension and postpartum incident hypertension on cardiovascular health: a nationwide population study

BACKGROUND

Gestational hypertension (GH) is a common complication of pregnancy and is associated with increased risk of incident hypertension in later life (IH) and cardiovascular events. However, the interactive effect of GH and IH on postpartum cardiovascular health remains unclear.

METHODS AND RESULTS

A nationwide population-based study was conducted using 1 million individuals from the Taiwan National Health Insurance database. Records from 1998 to 2009 were used to identify 1260 pregnant women with GH and without previous cardiovascular disease. The control group comprised 5040 pregnant women without GH, matched for age and date of delivery. During the follow-up period (median duration, 5.8 years), 182 cardiovascular events developed. Women with GH had significantly higher risk of cardiovascular events (hazard ratio [95% CI], 2.44 [1.80 to 3.31]) and IH (8.29 [6.30 to 10.91]) than controls. Compared with women without GH and IH, there was a significantly higher risk of cardiovascular events for women without GH but with IH (relative risk [95% CI], 2.89 [1.27-6.58]), women with GH but without IH (1.66 [1.16-2.39]), and women with GH and IH (8.11 [5.36-12.30]). The synergy index was 2.91 (95% CI 1.11 to 7.59), suggesting a positive interaction between GH and IH.

CONCLUSIONS

GH increased the risk of subsequent IH. Women with both GH and IH were at a substantially higher cardiovascular risk than were women with either GH or IH. The synergistic adverse effect of GH and IH on postpartum cardiovascular health indicates that more attention should be paid to this special population.

Evaluation of association of maternal IL-10 polymorphisms with risk of preeclampsia by A meta-analysis

Emerging evidence shows that interleukin (IL)-10 gene polymorphisms can regulate its expression level and thus influence person's susceptibility to preeclampsia. However, various published results were inconsistent. To explore the association between maternal IL-10 gene polymorphisms and preeclampsia, we performed a meta-analysis based upon 11 individual studies here. Our meta-analysis results indicated that IL-10 -819C/T (C versus T, OR = 1.28, 95% CI = 1.08–1.50, P = 0.003) and -592C/A (C versus A, OR = 1.28, 95% CI = 1.03–1.59, P = 0.03) polymorphisms were associated with preeclampsia. Although there was no overall association between -1082A/G polymorphism and preeclampsia (G versus A, OR = 0.93, 95% CI = 0.77–1.13, P = 0.49), such association existed among Asian (G versus A, OR = 1.29, 95% CI = 1.04–1.60, P = 0.02) and South American (G versus A, OR = 0.72, 95% CI = 0.54–0.94, P = 0.02) populations in the subgroup analysis stratified by continents.

Novel cardiovascular biomarkers in women with a history of early preeclampsia

OBJECTIVE

Women with a history of preeclampsia are at increased risk for future cardiovascular disease. Determination of cardiovascular biomarkers may be useful to understand the pathophysiological mechanism of cardiovascular disease development in these women.

METHODS

We performed an analysis in the Preeclampsia Risk EValuation in FEMales study, a retrospective cohort consisting of 339 women with a history of early preeclampsia and 332 women after normotensive pregnancy. Women attended a follow-up visit ten years after the index pregnancy. A subset of 8 different cardiovascular biomarkers was investigated, reflecting inflammatory, metabolic, thrombotic and endothelial function markers. Associations between PE and these novel biomarkers were analyzed by linear regression analysis and adjusted for traditional cardiovascular risk factors.

RESULTS

Mean age of 671 women of the PREVFEM cohort was 39 years and women were on average 10 years post index pregnancy. Women post preeclampsia had significantly higher levels of SE-selectin (adjusted difference 4.55, 99%CI 0.37; 8.74) and PAPPA (adjusted difference 19.08; 99%CI 13.18; 24.99), whereas ApoB (adjusted difference -0.23 99%CI -0.32; -0.14) was inversely associated with preeclampsia, compared to women with a previous normotensive pregnancy. Adiponectin, leptin, sICAM-1, sVCAM-1 and PAI-1 were not different between both groups.

CONCLUSION

We demonstrated an independent association of preeclampsia with SE-selectin and PAPPA (markers of vascular dysfunction), which may contribute to future cardiovascular events in women post preeclampsia. However, ApoB (an apolipoprotein) was significantly lower and could point at a protective mechanism in our PE study women.

Tissue inhibitor of matrix metalloproteinase-1 polymorphism, plasma TIMP-1 levels, and antihypertensive therapy responsiveness in hypertensive disorders of pregnancy

Tissue inhibitor of metalloproteinase (TIMP)-1 is a major endogenous inhibitor of matrix metalloproteinase (MMP)-9, which may affect the responsiveness to therapy in hypertensive disorders of pregnancy. We examined whether TIMP-1 polymorphism (g.-9830T>G, rs2070584) modifies plasma MMP-9 and TIMP-1 levels and the response to antihypertensive therapy in 596 pregnant: 206 patients with preeclampsia (PE), 183 patients with gestational hypertension (GH) and 207 healthy pregnant controls. We also studied the TIMP-3 polymorphism (g.-1296T>C, rs9619311). Plasma MMP-9 and TIMP-1 levels were measured by ELISA. GH patients with the GG genotype for the TIMP-1 polymorphism had lower MMP-9 levels and MMP-9/TIMP-1 ratios than those with the TT genotype. PE patients with the TG genotype had higher TIMP-1 levels. The G allele and the GG genotype were associated with PE and responsiveness to antihypertensive therapy in PE, but not in GH. Our results suggest that the TIMP-1 g.-9830T>G polymorphism not only promotes PE but also decreases the responses to antihypertensive therapy.

Enhancement of the HIF-1α/15-LO/15-HETE axis promotes hypoxia-induced endothelial proliferation in preeclamptic pregnancy

Preeclampsia (PE) is an extremely serious condition in pregnant women and the leading cause of maternal and fetal morbidity and mortality. Despite active research, the etiological factors of this disorder remain elusive. The increased release of 15-hydroxyeicosatetraenoic acid (15-HETE) in the placenta of preeclamptic patients has been studied, but its exact role in PE pathogenesis remains unknown. Mounting evidence shows that PE is associated with placental hypoxia, impaired placental angiogenesis, and endothelial dysfunction. In this study, we confirmed the upregulated expression of hypoxia-inducible factor 1α (HIF-1α) and 15-lipoxygenase-1/2 (15-LO-1/2) in patients with PE. Production of the arachidonic acid metabolite, 15-HETE, also increased in the preeclamptic placenta, which suggests enhanced activation of the HIF-1α–15-LO–15-HETE axis. Furthermore, this study is the first to show that the umbilical cord of preeclamptic women contains significantly higher serum concentrations of 15-HETE than that of healthy pregnant women. The results also show that expression of 15-LO-1/2 is upregulated in both human umbilical vein endothelial cells (HUVECs) collected from preeclamptic women and in those cultured under hypoxic conditions. Exogenous 15-HETE promotes the migration of HUVECs and in vitro tube formation and promotes cell cycle progression from the G0/G1 phase to the G2/M + S phase, whereas the 15-LO inhibitor, NDGA, suppresses these effects. The HIF-1α/15-LO/15-HETE pathway is therefore significantly associated within the pathology of PE.

Vitamin D status and hypertensive disorders in pregnancy

PURPOSE

Several studies have reported increased risk of preeclampsia when 25-hyrdoxyvitamin D (25[OH]D) levels are low. The extent to which 25(OH)D may lower risk for hypertensive disorder during pregnancy remains unclear.

METHODS

Among women enrolled in the Project Viva prenatal cohort in Massachusetts, we examined associations of 25(OH)D levels obtained at 16.4-36.9 weeks of gestation (mean 27.9 weeks) with hypertensive disorders of pregnancy, including preeclampsia (56/1591, 3.5%) and gestational hypertension (109/1591, 6.9%).

RESULTS

We did not detect an association between plasma 25(OH)D concentration (mean 58, standard deviation 22 nmol/L) and preeclampsia. For each 25 nmol/L increase in 25(OH)D, the adjusted odds ratio for preeclampsia was 1.14 (95% confidence interval, 0.77-1.67). By contrast and contrary to hypothesis, higher 25(OH)D concentrations were associated with higher odds of gestational hypertension: adjusted odds ratio for gestational hypertension was 1.32 (95% confidence interval, 1.01-1.72) per each 25 nmol/L increment in 25(OH)D. Vitamin D intake patterns suggest that this association was not because of reverse causation. Although the elevated hypertension risk may be due to chance, randomized trials of vitamin D supplementation during pregnancy should monitor for gestational hypertension.

CONCLUSIONS

These data do not support the hypothesis that higher 25(OH)D levels lower the overall risk of hypertensive disorders of pregnancy.

Dynamic Cerebral Autoregulation in Pregnancy and the Risk of Preeclampsia

Preeclampsia may affect severely the cerebral circulation leading to impairment of cerebral autoregulation, edema, and ischemia. It is not known whether impaired autoregulation occurs before the clinical onset of preeclampsia, and whether this can predict the occurrence of preeclampsia. Seventy-two women at 25 to 28 weeks of gestation were studied. Control values were derived from 26 nonpregnant women. Dynamic properties of cerebral autoregulation (DCA) were measured in the middle and posterior cerebral artery using transcranial Doppler and transfer function analysis (phase and gain) of respiratory-induced 0.1 Hz hemodynamic oscillations. Uterine artery ultrasound was performed to search for a notch sign as an early marker of general endothelial dysfunction. All women were followed up until 6 weeks after delivery for the occurrence of preeclampsia. The autoregulation parameter gain did not differ between pregnant and nonpregnant women. Phase was slightly but significantly higher in pregnant women, indicating better DCA. Women with a notch sign did not show altered DCA. A history of preeclampsia during a previous pregnancy was associated with lower phase in middle cerebral artery and posterior cerebral artery ( P <0.05 each). During follow-up, 9 women developed preeclampsia. None of the DCA parameters were associated with the occurrence of preeclampsia. In conclusion, DCA is well preserved during late midterm pregnancy, even in women with disturbed uterine blood flow. Yet, pregnant women with preeclampsia in a previous pregnancy seem to have poorer DCA. Although limited in statistical power, this study does not support DCA as a strong early risk marker of preeclampsia.