Low Soluble Fms-Like Tyrosine Kinase-1, Endoglin, and Endothelin-1 Levels in Women With Confirmed or Suspected Preeclampsia Using Proton Pump Inhibitors

Anti-hypertensive therapy for preeclampsia: a network meta-analysis and systematic review

BACKGROUND

Preeclampsia (PE) is a pregnancy disorder that represents a major cause of maternal and perinatal morbidity and mortality.

METHODS

This network meta-analysis was registered with PROSPERO. We searched the PubMed, ClinicalTrials.gov. and Embase databases for studies published from inception to the 31st of March 2023. RevMan5.3 software provided by the Cochrane Collaboration was used for direct meta-analysis (DMA) statistical analysis. Funnel maps, network meta-analysis (NMA), the surface under the cumulative ranking curve (SUCRA) to rank the different interventions and publication bias were generated by STATA 17.0 software.

RESULTS

We included eight randomized controlled trials (RCTs) involving a total of 1192 women with PE; two studies were of high quality and six were of moderate quality. Eight interventions were addressed in the NMA. In the DMA, we found that blood pressure in the Ketanserin group were significantly higher than those in the Nicardipine group. NMA showed that blood pressure in the Dihydralazine group was significantly higher than that in the Methyldopa, Labetalol, Nicardipine and Diltiazem groups. And the blood pressure in the Labetalol group was significantly lower than that in the Nicardipine group. SUCRA values showed that Diltiazem was more effective in lowering blood pressure than other drugs looked at in this study.

CONCLUSION

According to the eight RCTs included in this study, Diltiazem was the most effective in reducing blood pressure in PE patients; Labetalol and Nicardipine also had good effects. Diltiazem is preferred for the treatment of patients with severe PE and high blood pressure.

The effects of proton pump inhibitors during pregnancy on treatment of preeclampsia and related outcomes: a systematic review and meta-analysis

OBJECTIVE

This systematic review evaluated the available evidence on the effects of proton pump inhibitors during pregnancy on preeclampsia and related maternal, fetal, and neonatal outcomes.

DATA SOURCES

Five electronic databases (MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Trials, and Global Medicus Index) were searched on November 17, 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials of pregnant women who used any class or dose of proton pump inhibitor were eligible.

METHODS

A meta-analysis was conducted for all outcomes of interest using random-effects models. Results were presented as risk ratios or mean difference. Quality assessment was performed using the Risk of Bias 2 tool, and Grading of Recommendations, Assessment, Development, and Evaluations assessment was completed to evaluate the certainty of the evidence. The study was registered in the International Prospective Register of Systematic Reviews under identifier CRD42023423673.

RESULTS

Our search identified 3879 records that were screened independently by 2 authors. Nine reports (describing 8 trials) met our eligibility criteria, however, 6 trials were ultimately excluded from our analysis because women were only given proton pump inhibitors immediately before cesarean delivery for acid aspiration prevention. The 2 trials that were included in the meta-analysis evaluated the treatment of 177 women with diagnosed preeclampsia. For the primary outcomes, moderate-certainty evidence showed that the use of proton pump inhibitors likely has no effect on the risk for hemolysis, elevated liver enzymes, and low platelet count syndrome (risk ratio, 1.21; 95% confidence interval, 0.37-3.99; I²=0%) or perinatal mortality (risk ratio, 0.81; 95% confidence interval, 0.36-1.79; I²=0%), and there were insufficient data to conduct a meta-analysis on all other primary outcomes, including eclampsia and neonatal mortality. No trials investigated the use of proton pump inhibitors for the prevention of preeclampsia.

CONCLUSION

Given the limited outcome data, we are uncertain about the effect of proton pump inhibitors on women with preeclampsia. Further trials are required to determine what (if any) effects proton pump inhibitors might have for preeclampsia prevention or treatment.

Challenges in Conducting Clinical Trials for Preeclampsia

PURPOSE OF REVIEW

To review recent data describing the challenges and innovations in therapeutic research focused on the prevention and treatment of preeclampsia.

RECENT FINDINGS

Pregnant individuals have traditionally been excluded from therapeutic research, resulting in a paucity of innovation in therapeutics for pregnancy-specific medical conditions, especially preeclampsia. With the increased awareness of maternal morbidity and mortality, there is significant interest among researchers to expand therapeutic research in pregnancy. Several medications, including aspirin, pravastatin, metformin, and esomeprazole, which are commonly used in non-pregnant populations, are now being investigated for preeclampsia prevention. However, given the historic precedent of exclusion, along with the regulatory, ethical, and feasibility concerns that accompany this population, the study of these and novel medications has been complicated by numerous challenges. While complex, and laden with challenges, there is great ongoing need for therapeutic research to address preeclampsia. Aspirin, pravastatin, metformin, and esomeprazole have all shown promise as potential therapeutic agents; however, their use remains to be optimized, and innovative therapeutics need to be developed.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

A global view of hypertensive disorders and diabetes mellitus during pregnancy

Two important maternal cardiometabolic disorders (CMDs), hypertensive disorders in pregnancy (HDP) (including pre-eclampsia) and gestational diabetes mellitus (GDM), result in a large disease burden for pregnant individuals worldwide. A global consensus has not been reached about the diagnostic criteria for HDP and GDM, making it challenging to assess differences in their disease burden between countries and areas. However, both diseases show an unevenly distributed disease burden for regions with a low income or middle income, or low-income and middle-income countries (LMICs), or regions with lower sociodemographic and human development indexes. In addition to many common clinical, demographic and behavioural risk factors, the development and clinical consequences of maternal CMDs are substantially influenced by the social determinants of health, such as systemic marginalization. Although progress has been occurring in the early screening and management of HDP and GDM, the accuracy and long-term effects of such screening and management programmes are still under investigation. In addition to pharmacological therapies and lifestyle modifications at the individual level, a multilevel approach in conjunction with multisector partnership should be adopted to tackle the public health issues and health inequity resulting from maternal CMDs. The current COVID-19 pandemic has disrupted health service delivery, with women with maternal CMDs being particularly vulnerable to this public health crisis.

Associations Between Late-Onset Preeclampsia and the Use of Calcium-Based Antacids and Proton Pump Inhibitors During Pregnancy: A Prospective Cohort Study

Purpose

Preeclampsia is a leading cause of maternal morbidity and mortality. Calcium-based antacids and proton pump inhibitors (PPIs) are commonly used during pregnancy to treat symptoms of gastroesophageal reflux disease. Both have been hypothesized to reduce the risk of preeclampsia. We determined associations of calcium-based antacid and PPI use during pregnancy with late-onset preeclampsia (≥34 weeks of gestation), taking into account dosage and timing of use.

Patients and Methods

We included 9058 pregnant women participating in the PRIDE Study (2012–2019) or The Dutch Pregnancy Drug Register (2014–2019), two prospective cohorts in The Netherlands. Data were collected through web-based questionnaires and obstetric records. We estimated risk ratios (RRs) for late-onset preeclampsia for any use and trajectories of calcium-based antacid and PPI use before gestational day 238, and hazard ratios (HRs) for time-varying exposures after gestational day 237.

Results

Late-onset preeclampsia was diagnosed in 2.6% of pregnancies. Any use of calcium-based antacids (RR 1.2 [95% CI 0.9–1.6]) or PPIs (RR 1.4 [95% CI 0.8–2.4]) before gestational day 238 was not associated with late-onset preeclampsia. Use of low-dose calcium-based antacids in gestational weeks 0–16 (<1 g/day; RR 1.8 [95% CI 1.1–2.9]) and any use of PPIs in gestational weeks 17–33 (RR 1.6 [95% CI 1.0–2.8]) seemed to increase risks of late-onset preeclampsia. We did not observe associations between late-onset preeclampsia and use of calcium-based antacids (HR 1.0 [95% CI 0.6–1.5]) and PPIs (HR 1.4 [95% CI 0.7–2.9]) after gestational day 237.

Conclusion

In this prospective cohort study, use of calcium-based antacids and PPIs during pregnancy was not found to reduce the risk of late-onset preeclampsia.

Serum Collected from Preeclamptic Pregnancies Drives Vasoconstriction of Human Omental Arteries-A Novel Ex Vivo Model of Preeclampsia for Therapeutic Development

New-onset maternal hypertension is a hallmark of preeclampsia, driven by widespread endothelial dysfunction and systemic vasoconstriction. Here, we set out to create a new ex vivo model using preeclamptic serum to cause injury to the endothelium, mimicking vascular dysfunction in preeclampsia and offering the potential to evaluate candidate therapeutic interventions. Human omental arteries were collected at caesarean section from normotensive pregnant patients at term (n = 9). Serum was collected from pregnancies complicated by preterm preeclampsia (birth < 34 weeks’ gestation, n = 16), term preeclampsia (birth > 37 weeks’ gestation, n = 5), and healthy gestation-matched controls (preterm n = 16, term n = 12). Using wire myography, we performed ex vivo whole vessel assessment where human omental arteries were treated with increasing doses of each serum treatment (2−20%) and vasoreactivity was assessed. All pregnant serum treatments successfully drove vasoconstriction; no significant difference was observed in the degree of vasoconstriction when exposed to preeclamptic or control serum. We further demonstrated the ability of esomeprazole (a candidate therapeutic for preeclampsia; 0.1−100 µM) to drive vasorelaxation of pre-constricted vessels (only with serum from preeclamptic patients). In summary, we describe a novel human physiological model of preeclamptic vascular constriction. We demonstrate its exciting potential to screen drugs for their therapeutic potential as treatment for vasoconstriction induced by preeclampsia.

Assessment of the Proton Pump Inhibitor, Esomeprazole Magnesium Hydrate and Trihydrate, on Pathophysiological Markers of Preeclampsia in Preclinical Human Models of Disease

Previously, we demonstrated that the proton pump inhibitor, esomeprazole magnesium hydrate (MH), could have potential as a repurposed treatment against preeclampsia, a serious obstetric condition. In this study we investigate the difference in the preclinical effectiveness between 100 µM of esomeprazole MH and its hydration isomer, esomeprazole magnesium trihydrate (MTH). Here, we found that both treatments reduced secretion of sFLT-1 (anti-angiogenic factor) from primary cytotrophoblast, but only esomeprazole MH reduced sFLT-1 secretion from primary human umbilical vein endothelial cells (assessed via ELISA). Both drugs could mitigate expression of the endothelial dysfunction markers, vascular cell adhesion molecule-1 and endothelin-1 (via qPCR). Neither esomeprazole MH nor MTH quenched cytotrophoblast reactive oxygen species production in response to sodium azide (ROS assay). Finally, using wire myography, we demonstrated that both compounds were able to induce vasodilation of human omental arteries at 100 µM. Esomeprazole is safe to use in pregnancy and a candidate treatment for preeclampsia. Using primary human tissues and cells, we validated that esomeprazole is effective in enhancing vascular relaxation, and can reduce key factors associated with preeclampsia, including sFLT-1 and endothelial dysfunction. However, esomeprazole MH was more efficacious than esomeprazole MTH in our in vitro studies.

Proton Pump Inhibitors Use and Risk of Preeclampsia: A Meta-Analysis

Evidence from preclinical studies suggests a preventive effect of proton pump inhibitors (PPIs) in preeclampsia. Recently, several epidemiological studies have described a conflicting association between the use of PPIs during pregnancy and preeclampsia risk. This study aimed to evaluate the association between PPI use and the risk of preeclampsia. We searched databases, including MEDLINE, Embase, Scopus, Web of Science Core Collection, Emcare, CINAHL, and the relevant grey literature from inception until 13 September 2021. Studies reporting the preeclampsia risk with the use of PPIs were eligible for inclusion. Literature screening, data extraction, and the risk of bias assessment were performed independently by two investigators. Random-effect meta-analysis was performed to generate relative risks (RR) and 95% confidence intervals (CI). The risk of preeclampsia and preterm preeclampsia among women receiving PPIs during pregnancy were the primary outcomes of interest. This meta-analysis comprised three studies involving 4,877,565 pregnant women, of whom 119,017 were PPI users. The included studies were judged to have a low risk of bias. The risk of preeclampsia among pregnant women who received PPIs anytime during pregnancy was significantly increased (RR 1.27 (95% CI: 1.23-1.31)), although the increase was trivial in absolute terms (2 per 1000). The subgroup analysis revealed that the risk was increased in each of the three trimesters. The risk of preterm preeclampsia among pregnant women receiving PPIs anytime during pregnancy was not significantly increased (RR 1.04 (95% CI: 0.70-1.55)). The certainty evaluated by GRADE in these estimates was low. PPI use may be associated with a trivial increase in the risk of preeclampsia in pregnant women. There is no evidence supporting that PPI use decreases the risk of preeclampsia or preterm preeclampsia.

Mitochondrial Dysfunction in the Pathogenesis of Preeclampsia

PURPOSE OF REVIEW

Preeclampsia complicates 5-10% of all pregnancies and is a leading cause of maternal and perinatal mortality and morbidity. The placenta plays a pivotal role in determining pregnancy outcome by supplying the fetus with oxygen and nutrients and by synthesizing hormones. Placental function is highly dependent on energy supplied by mitochondria. It is well-known that preeclampsia is originated from placental dysfunction, although the etiology of it remains elusive.

RECENT FINDINGS

During the last three decades, substantial evidence suggests that mitochondrial abnormality is a major contributor to placental dysfunction. In addition, mitochondrial damage caused by circulating bioactive factors released from the placenta may cause endothelial dysfunction and subsequent elevation in maternal blood pressure. In this review, we summarize the current knowledge of mitochondrial abnormality in the pathogenesis of preeclampsia and discuss therapeutic approaches targeting mitochondria for treatment of preeclampsia.

Omeprazole Administration in Preterm Preeclampsia: a Randomized Controlled Trial to Study Its Effect on sFlt-1 (Soluble Fms-Like Tyrosine Kinase-1), PlGF (Placental Growth Factor), and ET-1 (Endothelin-1)

Low sFlt-1 (soluble Fms-like tyrosine kinase-1) and ET-1 (endothelin-1) levels have been reported in preeclamptic women using proton pump inhibitors.

Pravastatin, proton-pump inhibitors, metformin, micronutrients, and biologics: new horizons for the prevention or treatment of preeclampsia

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

Esomeprazole inhibits hypoxia/endothelial dysfunction–induced autophagy in preeclampsia

Preeclampsia (PE) affects 3 to 5% of pregnant women worldwide and is associated with fetal and maternal morbidity and mortality. Although a complete understanding of PE remains elusive, it has been widely accepted that a dysfunction of the placenta plays a key role in the pathogenesis of PE. In this study, we investigated the role of excessive placental autophagy during PE pathogenesis and explored whether esomeprazole ameliorates PE by inhibiting the autophagy in the placenta. The PE cellular model was established by treating the cells’ L-NAME and hypoxia. The PE mice model was established by L-NAME administration and was confirmed by the increased systolic blood pressure (SBP) and urinary protein detected. The autophagy and key proteins were detected in human placental tissue, in cells, and in the mice model by Western blot and immunofluorescence staining. Results showed that excessive autophagy could be detected in human PE placental tissue, in the PE cellular model, and in the PE mice model. Hypoxia induces autophagy by activating AMPKα and inhibiting mTOR in vivo and in vitro. Esomeprazole inhibits L‐NAME-induced autophagy in mice by inhibiting AMPKα and activating mTOR. In conclusion, this study demonstrates that the excessive autophagy induced by the SIRT1/AMPKα-mTOR pathway plays a significant role in the pathogenesis of PE. However, esomeprazole treatment inhibits AMPKα but activates mTOR, resulting in the inhibition of autophagy in the placenta and, therefore, mitigates PE symptoms.

Receipt of Proton-Pump Inhibitors during Pregnancy and Risk for Preeclampsia

OBJECTIVE

This study aimed to determine whether receiving a proton-pump inhibitor (PPI) prescription during pregnancy was associated with decreased risk for preeclampsia.

STUDY DESIGN

The Truven Health MarketScan database was used to determine whether receiving a PPI prescription was associated with risk for preeclampsia. Risk for preeclampsia was evaluated based on the presence or absence of receiving a PPI prescription (1) any time during pregnancy, and 2) individually during the 1st, 2nd, and 3rd trimesters. In addition to evaluating risk for all preeclampsia, severe preeclampsia and preterm severe preeclampsia were evaluated. Adjusted models including risk factors such as chronic hypertension, maternal age, multiple gestation, and diabetes were performed with adjusted risk ratios (aRR) with 95% confidence intervals [CIs] as measures of effect.

RESULTS

A total of 2,755,885 women were included in the analysis of whom 69,249 were prescribed a PPI during pregnancy (2.5%). In adjusted models, receiving a PPI prescription anytime during pregnancy (aRR 1.28, 95% CI 1.24-1.32), the 1st trimester (aRR 1.12, 95% CI 1.04-1.22), the 2nd trimester (aRR 1.20, 95% CI 1.15-1.26), and the 3rd trimester (aRR 1.41, 95% CI 1.35-1.47) were all associated with increased risk for preeclampsia. Risk for severe preeclampsia was also significantly increased with receiving a PPI prescription anytime during pregnancy (aRR 1.21, 95% CI 1.15-1.27), during the 2nd trimester (aRR 1.14, 95% CI 1.06-1.23), and during the 3rd trimester (aRR 1.33, 95% CI 1.24-1.43), but not the first trimester (aRR 1.04, 95% CI 0.92-1.19). Evaluating the risk for preterm severe preeclampsia, adjusted risk was significantly increased with receiving a PPI prescription in the second trimester (aRR 1.35, 95% CI 1.21-1.52) but not the first trimester (aRR 1.06, 95% CI 0.86-1.32).

CONCLUSION

In this analysis of payer data, receiving a PPI prescription during pregnancy was not associated with decreased risk for preeclampsia. Further empiric research is required to determine whether an effect may be present.

KEY POINTS

· Proton pump inhibitors were not associated with decreased risk for preeclampsia.. · Proton pump inhibitors were not associated with decreased risk for severe preterm preeclampsia.. · Proton pump inhibitors are commonly prescribed during pregnancy..

Megalin, Proton Pump Inhibitors and the Renin-Angiotensin System in Healthy and Pre-Eclamptic Placentas

Soluble Fms-like tyrosine kinase-1 (sFlt-1) is increased in pre-eclampsia. The proton pump inhibitor (PPI) lowers sFlt-1, while angiotensin increases it. To investigate whether PPIs lower sFlt-1 by suppressing placental renin–angiotensin system (RAS) activity, we studied gene expression and protein abundance of RAS components, including megalin, a novel endocytic receptor for prorenin and renin, in placental tissue obtained from healthy pregnant women and women with early-onset pre-eclampsia. Renin, ACE, ACE2, and the angiotensin receptors were expressed at identical levels in healthy and pre-eclamptic placentas, while both the (pro)renin receptor and megalin were increased in the latter. Placental prorenin levels were upregulated in pre-eclamptic pregnancies. Angiotensinogen protein, but not mRNA, was detectable in placental tissue, implying that it originates from maternal blood. Ex vivo placental perfusion revealed a complete washout of angiotensinogen, while prorenin release remained constant. The PPI esomeprazole dose-dependently reduced megalin/(pro)renin receptor-mediated renin uptake in Brown Norway yolk sac epithelial cells and decreased sFlt-1 secretion from placental villous explants. Megalin inhibition blocked angiotensinogen uptake in epithelial cells. In conclusion, our data suggest that placental RAS activity depends on angiotensinogen taken up from the maternal systemic circulation. PPIs might interfere with placental (pro)renin-AGT uptake/transport, thereby reducing angiotensin formation as well as angiotensin-induced sFlt-1 synthesis.

Downregulation of Cullin 3 Ligase Signaling Pathways Contributes to Hypertension in Preeclampsia

Background: Preeclampsia (PE) is a leading cause of maternal and perinatal morbidity and mortality; however, its etiology and pathophysiology remain obscure. PE is initiated by inadequate spiral artery remodeling and subsequent placental ischemia/hypoxia, which stimulates release of bioactive factors into maternal circulation, leading to hypertension and renal damage. Methods and Results: Abundance of key components of cullin 3-ring ubiquitin ligase (CRL3), including cullin 3 (CUL3) and its neddylated modification, and adaptors including Kelch-like 2 (KLHL2) and Rho-related BTB domain containing protein 1 was all decreased in spiral arteries and placentas of PE patients. Similar changes were found in aortic tissues and renal distal tubules of pregnant mice treated with Nω-nitro-l-arginine methyl ester hydrochloride. The downregulation of CRL3 function led to accumulation of with-no-lysine kinases, phosphodiesterase 5, and RhoA in vessels and renal distal tubules, which promoted vasoconstriction and Na-Cl cotransporter activation in the distal convoluted tubule (DCT), as well as vascular and DCT structure remodeling. Proton pump inhibitor esomeprazole partially restored CRL3 function. In vitro studies have shown that increased abundance of JAB1, a component of the COP9 signalosome, inhibited CUL3 neddylation and promoted the expression of hypoxia-inducible factor 1α, which downregulated peroxisome proliferator-activated receptor γ and further promoted CUL3 inactivation. KLHL3/2 was degraded by increased autophagy. Conclusion: These findings support that the downregulation of CRL3 function disrupts the balance of vasoconstriction and vasodilation and aggravates excess reabsorption of sodium in PE.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction

BACKGROUND

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders.

OBJECTIVE AND RATIONALE

The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth.

SEARCH METHODS

An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020).

OUTCOMES

Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR.

WIDER IMPLICATIONS

There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.

Differential expression of serum proteins before 20 weeks gestation in women with hypertensive disorders of pregnancy: A potential role for SH3BGRL3

INTRODUCTION

The objective of this study was to explore serum levels of differentially abundant proteins between women with hypertensive disorders of pregnancy (HDP) and women with normal-term pregnancy, and to explore the contribution of SH3BGRL3 to the pathogenesis of HDP.

METHODS

At 6-20 weeks gestation 48 pregnant women who later developed HDP (HDP group) and 48 women with normal-term pregnancy (normal group) were recruited based on maternal age and gestational age at a 1:1 ratio. Total serum protein was extracted, denatured, deoxidized, and subjected to enzymolysis. The sample was labeled with Tandem Mass Tags and analyzed via mass spectroscopy to identify differentially abundant proteins. The role of SH3BGRL3 in trophoblast invasion, proliferation and apoptosis was examined using the HTR-8/SVneo cell line and primary isolates of extravillous trophoblast (EVT) cells.

RESULTS

In the proteomic profiling analysis, there were 19 proteins that showed significant differential abundance (P < 0.05). Among them, 13 proteins were more abundant and 6 proteins were less abundant in the serum from the HDP group compared with the normal group. The function of one of the more abundant proteins, SH3BGRL3, in trophoblast cell invasion, proliferation and apoptosis was investigated. Treatment of the EVT cells or the HTR-8/SVneo cell line with anti-SH3BGRL3 inhibited proliferation, but stimulated both apoptosis and invasion. MMP2 and p-ERK levels were also decreased in EVT after anti-SH3BGRL3 treatment.

DISCUSSION

The SH3BGRL3 protein can regulate various aspects of trophoblast biology, and may be useful in the clinical diagnosis of HDP.

Contribution of placental 11β-HSD2 to the pathogenesis of preeclampsia

Preeclampsia, a major human pregnancy-specific disorder, leads to maternal and fetal morbidity and mortality. Here we reported that 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), an enzyme that degrades active glucocorticoids, is one of the key factors that contributes to preeclampsia development. In the pregnant rat model, we firstly confirmed that administration of 11β-HSD2 inhibitor carbenoxolone (CBX) subcutaneously or by placenta-targeted delivery system could lead to a decrease in placental 11β-HSD2 expression and activity and an increase in corticosterone level in placenta and maternal circulation. Then, we showed that subcutaneous administration and placenta-targeted delivery of CBX resulted in the hallmark of preeclampsia-like features including hypertension, proteinuria, renal damages as well as elevated circulatory soluble fms-like tyrosine kinase 1 (sFlt1) and increased sFlt1/placental growth factor (PlGF) ratio in pregnant rats. These animals displayed decreased trophoblast invasion in uterus, impaired spiral artery remodeling, and reduced placental blood flow. Preeclampsia-like features could also be induced by administration of dexamethasone in pregnant rats. In the cultured human trophoblast models, we found that cortisol only inhibited migration and invasion of the extravillous trophoblasts with 11β-HSD2 knockdown, and promoted sFlt1 release in the cultured syncytiotrophoblasts with 11β-HSD2 knockdown. Furthermore, we elucidated that cortisol stimulated a disintegrin and metalloprotease (ADAM)17 expression in placentas, thereby promoting sFlt1 release in placenta. Collectively, our study provided the evidence that placental 11β-HSD2 dysfunction plays a key role in the development of preeclampsia and immediately identified innovative target to counteract preeclampsia.

Novel approaches to combat preeclampsia: from new drugs to innovative delivery

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

Esomeprazole and sulfasalazine in combination additively reduce sFlt-1 secretion and diminish endothelial dysfunction: potential for a combination treatment for preeclampsia

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

MZe786 Rescues Cardiac Mitochondrial Activity in High sFlt-1 and Low HO-1 Environment

Hypertensive disorder in pregnancy is a major cause of maternal and perinatal mortality worldwide. Women who have had preeclampsia are at three to four times higher risk in later life of developing high blood pressure and heart disease. Soluble Flt-1 (sFlt-1) is elevated in preeclampsia and may remain high postpartum in women with a history of preeclampsia. Heme oxygenase-1 (Hmox1/HO-1) exerts protective effects against oxidative stimuli and is compromised in the placenta of pregnant women with preeclampsia. We hypothesized that sFlt-1 inhibits cardiac mitochondrial activity in HO-1 deficient mice. HO-1 haplo-insufficient mice (Hmox1^+/−) were injected with adenovirus encoding sFlt-1 (Ad-sFlt-1) or control virus (Ad-CMV). Subsequently, they were treated daily with either placebo or MZe786 for six days, when the heart tissue was harvested to assess cardiac mitochondrial activity. Here, we show that the loss of HO-1 disturbed cardiac mitochondrial respiration and reduced mitochondrial biogenesis. The overexpression of sFlt-1 resulted in the inhibition of the cardiac mitochondrial activity in Hmox1^+/− mice. The present study demonstrates that the hydrogen sulfide (H₂S) releasing molecule, MZe786, rescues mitochondrial activity by stimulating cardiac mitochondrial biogenesis and antioxidant defense in Hmox1^−/− mice and in Hmox1^+/− mice exposed to a high sFlt-1 environment.

Human Placental Vascular Reactivity in Health and Disease: Implications for the Treatment of Pre-eclampsia

Adequate development of the placenta is essential for optimal pregnancy outcome. Pre-eclampsia (PE) is increasingly recognized to be a consequence of placental dysfunction and can cause serious maternal and fetal complications during pregnancy. Furthermore, PE increases the risk of neonatal problems and has been shown to be a risk factor for cardiovascular disease of the mother later in life. Currently, there is no adequate treatment for PE, mainly because its multifactorial pathophysiology remains incompletely understood. It originates in early pregnancy with abnormal placentation and involves a cascade of dysregulated systems in the placental vasculature. To investigate therapeutic strategies it is essential to understand the regulation of vascular reactivity and remodeling of blood vessels in the placenta. Techniques using human tissue such as the ex vivo placental perfusion model provide insight in the vasoactive profile of the placenta, and are essential to study the effects of drugs on the fetal vasculature. This approach highlights the different pathways that are involved in the vascular regulation of the human placenta, changes that occur during PE and the importance of focusing on restoring these dysfunctional systems when studying treatment strategies for PE.

Novel Interventions for the Prevention of Preeclampsia

PURPOSE OF REVIEW

To review the rationale and biological plausibility and discuss the current research on novel interventions for the prevention of preeclampsia.

RECENT FINDINGS

Preeclampsia affects up to 8% of pregnancies worldwide and remains a major cause of maternal and neonatal morbidity and mortality. Multiple medications have been investigated or repurposed as potential effective interventions for preeclampsia prevention. Aspirin is currently the only drug for which there is some evidence of benefit for preeclampsia prevention, and its use is recommended by professional societies for pregnancies at risk. Statins have shown promise for prevention of preeclampsia in animal models and human pilot studies, without any trend or concerns for safety signals or teratogenicity. The use of metformin has also gained popularity in experimental studies, but observations from randomized clinical trials were not consistent on its utility as a possible intervention for preeclampsia prevention. While initial studies evaluating esomeprazole were promising, randomized trials failed to show benefit. Contemporary research shows exciting new opportunities for prophylactic treatment for preeclampsia, to prevent this debilitating and life-threatening disease.

Maternal use of drugs and preeclampsia

AIMS

The aim was to compare and describe maternal use of drugs between women with preeclampsia and controls and to estimate the possible association with preeclampsia.

METHODS

The study cohort was collected from the Kuopio University Hospital Birth Register, which includes information about all women who gave birth in Kuopio University Hospital during the years 2002-2016, including information from approximately 36 000 parturients, of whom 1252 had preeclampsia. Maternal use of 16 groups of drugs during pregnancy was analysed from all women with preeclampsia and 1256 controls.

RESULTS

Every second woman had used at least 1 drug during pregnancy but those with preeclampsia had used significantly more than the controls (cases 59.5% vs controls 35.5%; p < 0.001). In both study groups, the most commonly used drugs were antibiotics (cases 19.5%, controls 17.0%), antihypertensives (cases 29.0%, controls 7.6%) and paracetamol (cases 13.1%, controls 5.9%). Women with preeclampsia had used significantly more benzodiazepines, paracetamol, antihypertensives and acid-suppressive drugs than the women in the control group (p < 0.05).

CONCLUSIONS

Women with preeclampsia were more likely to use medicines during pregnancy. While the association between benzodiazepines, antihypertensives and acid-suppressive drugs and preeclampsia may be explained by reverse causation, the association of paracetamol with preeclampsia remains to be clarified. Because paracetamol is a frequently used drug, more information about its safety during pregnancy including its role in preeclampsia is urgently needed.

Proton Pump Inhibitors and Preeclampsia Risk Among 157 720 Women

Preeclampsia is a hypertensive disorder of pregnancy with a high rate of maternal and neonatal morbidity and mortality. The only definite treatment is delivery. Preclinical investigations have identified proton pump inhibitors (PPIs), which are commonly used to treat reflux during pregnancy, as a potential treatment for preeclampsia. The aim of this study was to determine the association between PPI use during pregnancy and preeclampsia risk in a population-based register cohort. Using the Swedish Pregnancy Register, we conducted a cohort study of nulliparous pregnant women delivering from January 2013 to July 2017. Associations between PPI use and preeclampsia were investigated using logistic regression analyses with risk estimates presented as crude and adjusted odds ratios (aOR) with 95% CI. Of 157 720 nulliparous pregnant women, 6051 (3.8%) reported PPI use during pregnancy. PPI use during any point of pregnancy was associated with an increased risk of overall preeclampsia (aOR of 1.17; 95% CI, 1.04-1.32) and preeclampsia at term (aOR of 1.20; 95% CI, 1.04-1.39). However, PPI use recorded after 28 gestational weeks was associated with a reduced risk of preterm (delivery <37 weeks) preeclampsia (aOR of 0.63; 95% CI, 0.41-0.96) and early (delivery <34 weeks) preeclampsia (aOR of 0.41; 95% CI, 0.20-0.82). These findings highlight the heterogeneity of this disease, with a potential role PPIs for preventing preterm preeclampsia when used in close proximity to disease onset. Targeting PPI use to women at greatest risk of preterm preeclampsia may help prevent this severe form of disease.

Targeting the vascular dysfunction: Potential treatments for preeclampsia

Preeclampsia is a pregnancy-specific disorder, primarily characterized by new-onset hypertension in combination with a variety of other maternal or fetal signs. The pathophysiological mechanisms underlying the disease are still not entirely clear. Systemic maternal vascular dysfunction underlies the clinical features of preeclampsia. It is a result of oxidative stress and the actions of excessive anti-angiogenic factors, such as soluble fms-like tyrosine kinase, soluble endoglin, and activin A, released by a dysfunctional placenta. The vascular dysfunction then leads to impaired regulation and secretion of relaxation factors and an increase in sensitivity/production of constrictors. This results in a more constricted vasculature rather than the relaxed vasodilated state associated with normal pregnancy. Currently, the only effective "treatment" for preeclampsia is delivery of the placenta and therefore the baby. Often, this means a preterm delivery to save the life of the mother, with all the attendant risks and burdens associated with fetal prematurity. To lessen this burden, there is a pressing need for more effective treatments that target the maternal vascular dysfunction that underlies the hypertension. This review details the vascular effects of key drugs undergoing clinical assessment as potential treatments for women with preeclampsia.

Beta-Arrestin1 Prevents Preeclampsia by Downregulation of Mechanosensitive AT1-B2 Receptor Heteromers

Preeclampsia is the most frequent pregnancy-related complication worldwide with no cure. While a number of molecular features have emerged, the underlying causal mechanisms behind the disorder remain obscure. Here, we find that increased complex formation between angiotensin II AT1 and bradykinin B2, two G protein-coupled receptors with opposing effects on blood vessel constriction, triggers symptoms of preeclampsia in pregnant mice. Aberrant heteromerization of AT1-B2 led to exaggerated calcium signaling and high vascular smooth muscle mechanosensitivity, which could explain the onset of preeclampsia symptoms at late-stage pregnancy as mechanical forces increase with fetal mass. AT1-B2 receptor aggregation was inhibited by beta-arrestin-mediated downregulation. Importantly, symptoms of preeclampsia were prevented by transgenic ARRB1 expression or a small-molecule drug. Because AT1-B2 heteromerization was found to occur in human placental biopsies from pregnancies complicated by preeclampsia, specifically targeting AT1-B2 heteromerization and its downstream consequences represents a promising therapeutic approach.

Esomeprazole to treat women with preterm preeclampsia: a randomized placebo controlled trial

BACKGROUND

Preterm preeclampsia has a high rate of fetal death or disability. There is no treatment to slow the disease, except delivery. Preclinical studies have identified proton pump inhibitors as a possible treatment.

OBJECTIVE

The purpose of this study was to examine whether esomeprazole could prolong pregnancy in women who have received a diagnosis of preterm preeclampsia.

STUDY DESIGN

We performed a double-blind, randomized controlled trial at Tygerberg Hospital in South Africa. Women with preterm preeclampsia (gestational age 26 weeks+0 days to 31 weeks+6 days) were assigned randomly to 40-mg daily esomeprazole or placebo. The primary outcome was a prolongation of gestation of 5 days. Secondary outcomes were maternal and neonatal outcomes. We compared circulating markers of endothelial dysfunction that was associated with preeclampsia and performed pharmacokinetic studies.

RESULTS

Between January 2016 and April 2017, we recruited 120 participants. One participant was excluded because of incorrect randomization, which left 59 participants in the esomeprazole and 60 participants in the placebo group. Median gestational age at enrolment was 29+4 weeks gestation. There were no between-group differences in median time from randomization to delivery: 11.4 days (interquartile range, 3.6-19.7 days) in the esomeprazole group and 8.3 days (interquartile range, 3.8-19.6 days) in the placebo group (3 days longer in the esomeprazole arm; 95% confidence interval, -2.9-8.8; P=.31). There were no placental abruptions in the esomeprazole group and 6 (10%) in the placebo group (P=.01, P=.14 adjusted). There were no differences in other maternal or neonatal outcomes or markers of endothelial dysfunction. Esomeprazole and its metabolites were detected in maternal blood among those treated with esomeprazole, but only trace amounts in the umbilical cord blood.

CONCLUSION

Daily esomeprazole (40 mg) did not prolong gestation in pregnancies with preterm preeclampsia or decrease circulating soluble fms-like tyrosine kinase 1 concentrations. Higher levels in the maternal circulation may be needed for clinical effect.

Preeclampsia: Novel Mechanisms and Potential Therapeutic Approaches

Preeclampsia is a serious complication of pregnancy where it affects 5–8% of all pregnancies. It increases the morbidity and mortality of both the fetus and pregnant woman, especially in developing countries. It deleteriously affects several vital organs, including the kidneys, liver, brain, and lung. Although, the pathogenesis of preeclampsia has not yet been fully understood, growing evidence suggests that aberrations in the angiogenic factors levels and coagulopathy are responsible for the clinical manifestations of the disease. The common nominator of tissue damage of all these target organs is endothelial injury, which impedes their normal function. At the renal level, glomerular endothelial injury leads to the development of maternal proteinuria. Actually, peripheral vasoconstriction secondary to maternal systemic inflammation and endothelial cell activation is sufficient for the development of preeclampsia-induced hypertension. Similarly, preeclampsia can cause hepatic and neurologic dysfunction due to vascular damage and/or hypertension. Obviously, preeclampsia adversely affects various organs, however it is not yet clear whether pre-eclampsia per se adversely affects various organs or whether it exposes underlying genetic predispositions to cardiovascular disease that manifest in later life. The current review summarizes recent development in the pathogenesis of preeclampsia with special focus on novel diagnostic biomarkers and their relevance to potential therapeutic options for this disease state. Specifically, the review highlights the renal manifestations of the disease with emphasis on the involvement of angiogenic factors in vascular injury and on how restoration of the angiogenic balance affects renal and cardiovascular outcome of Preeclamptic women.

First trimester prediction and prevention of adverse pregnancy outcomes related to poor placentation

PURPOSE OF REVIEW

To summarize recent research findings related to first trimester prediction and prevention of adverse pregnancy outcomes associated with poor placentation. Recent publications related to prediction and prevention of preeclampsia, intrauterine growth restriction (IUGR) and stillbirth were reviewed.

RECENT FINDINGS

Researchers continue to identify markers that will help predict pregnancies that go on to develop preeclampsia through screening at 11-13 weeks. A number of multivariate algorithms describing risks for preeclampsia have been published and some of these have been validated in independent populations. A large randomized controlled trial has proven the efficacy of a first trimester prediction - prevention programme for preeclampsia with an 80% reduction in prevalence of disease leading to delivery less than 34 weeks. Screening tools for IUGR and stillbirth are less advanced and require further validation in other populations. The value of these models in preventing disease still needs to be demonstrated.

SUMMARY

Significant progress has been made in developing predictive and preventive strategies which can affect the prevalence of severe early-onset preeclampsia. This approach could be adopted for population-based screening aiming to prevent this disease.

Long Non-Coding RNAs Serve as Diagnostic Biomarkers of Preeclampsia and Modulate Migration and Invasiveness of Trophoblast Cells

Background

Long non-coding RNAs (lncRNAs) have emerged as crucial regulators of tumor progression. However, the effects of lncRNAs in preeclampsia are not entirely clear. The aim of this study was to demonstrate the potential of lncRNAs to serve as biomarkers in preeclampsia.

Material/Methods

The RNA expression levels of lncRNAs (NR_027457, BC030099, AF037219, NR_024178, AF085938, G43016, G36948, NR_029420, NR_024015, AK002210, NR_026643, and AL049277) in the serum of patients with preeclampsia and in the serum of normal controls were measured by qRT-PCR. The area under the curve (AUC), the optimal cut-off values, the specificity, and the sensitivity of NR_027457, AF085938, G36948, and AK002210 were analyzed by receiver operating characteristic (ROC) curve analysis. We designed RNA interference species to suppress NR_027457 and G36948 and identified the roles of NR_027457 and G36948 in the functions of a trophoblast cell line (HTR-8/SVneo).

Results

The qRT-PCR results indicated that NR_027457 and AF085938 were significantly up-regulated, whereas G36948 and AK002210 were significantly down-regulated in preeclampsia. We found that NR_027457, AF085938, G36948, and AK002210 had potential diagnostic value for the detection of preeclampsia. Furthermore, the levels of NR_027457, AF085938, G36948, and AK002210 in the serum of patients were significantly different before vs. after surgery. The silencing of NR_027457 inhibited the proliferation, migration, and invasion abilities of HTR-8/SVneo cells, while the silencing of G36948 promoted the proliferation, migration, and invasion abilities of HTR-8/SVneo cells.

Conclusions

NR_027457, AF085938, G36948, and AK002210 can serve as potential diagnostic biomarkers in preeclampsia, and NR_027457 and G36948 might be involved in the pathogenesis of preeclampsia.