Latest advances in understanding preeclampsia

Hypertensive diseases of pregnancy and risk of breast cancer in the Black Women's Health Study

PURPOSE

Compared to white women, Black women have increased risk of developing hypertensive diseases of pregnancy (HDOP) and have a higher incidence of aggressive breast cancer subtypes. Few studies of HDOP and breast cancer risk have included large numbers of Black women. This study examined the relation of HDOP to incidence of breast cancer overall and by estrogen receptor (ER) status in Black women.

METHODS

We followed 42,982 parous women in the Black Women's Health Study, a nationwide prospective study of Black women. Multivariable Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to assess associations of self-reported HDOP, including preeclampsia and gestational hypertension, with breast cancer incidence overall and by ER subtype, adjusted for age and established breast cancer risk factors.

RESULTS

Over 20 years of follow-up, we identified 2376 incident breast cancer cases. History of HDOP (11.7%) was not associated with breast cancer risk overall (HR 0.98; 95% CI 0.87, 1.11). HRs for invasive ER+ and ER- breast cancer were 1.11 (95% CI 0.93, 1.34) and 0.81 (95% CI 0.61, 1.07), respectively.

CONCLUSIONS

HDOP was not associated with risk of overall breast cancer in Black women. A suggestive inverse association with ER- breast cancer may reflect an anti-tumorigenic hormone profile in HDOP, but those results require confirmation in other studies.

Soluble endoglin versus sFlt-1/PlGF ratio: detection of preeclampsia, HELLP syndrome, and FGR in a high-risk cohort

The angiogenic factors sFlt-1 and PlGF play an established role in the detection of preeclampsia (PE). Recent data suggest that sEng might contribute to the pathogenesis of PE. However, only a few studies so far have addressed its role.This monocentric cross-sectional study of high-risk pregnancies aims to compare the levels of sFlt-1/PlGF ratio and sEng depending on different placental-related adverse pregnancy outcomes. The statistical analysis takes into account Pearson's correlation coefficient between angiogenic factors, the area under the curve estimates (AUCs) for detection, and adjusted odds ratios (aOR) with 95% confidence intervals (95%-CIs). The analysis included 206 patients: 60 controls, 90 PE (59 EOPE, 35 LOPE), 94 FGR, and 35 HELLP cases. Some outcomes overlapped because FGR commonly complicated PE and HELLP syndrome. Serum levels of sFlt-1/PlGF and sEng correlated with each other. Higher levels were observed in HELLP syndrome and EOPE cases. AUCs for sFlt-1/PlGF ratio and sEng were, respectively, 0.915 (95%-Cl 0.87-0.96) and 0.872 (95%-Cl 0.81-0.93) in PE, 0.895 (95%-Cl 0.83-0.96) and 0.878 (95%-Cl 0.81-0.95) in HELLP syndrome, 0.891 (95%-Cl 0.84-0.94), and 0.856 (95%-Cl 0.79-0.92) in FGR.aORsfor sFlt-1/PlGF ratio and sEng were, respectively: 2.69 (95%-Cl 1.86-3.9) and 2.33 (95%-Cl 1.59-3.48) in PE, 2.38 (95%-Cl 1.64-3.44) and 2.28 (95%-Cl 1.55-3.4) in FGR, and 2.10 (95%-Cl 1.45-3.05) and 1.88 (95%-Cl 1.31-2.69) in HELLP syndrome. In addition, the aORs between sFlt-1/PlGF and sEng were very similar but higher for PE and FGR than HELLP syndrome.In conclusion,sEng performed similarly to sFlt-1/PlGF to detect placental dysfunctions.

Mesenchymal Stem/Stromal Cells and Their Role in Oxidative Stress Associated with Preeclampsia

Preeclampsia (PE) is a serious medically important disorder of human pregnancy, which features de novo pregnancy-induced hypertension and proteinuria. The severe form of PE can progress to eclampsia, a convulsive, life-threatening condition. When placental growth and perfusion are abnormal, the placenta experiences oxidative stress and subsequently secretes abnormal amounts of certain pro-angiogenic factors (eg, PlGF) as well as anti-angiogenic factors (eg, sFlt-1) that enter the maternal circulation. The net effect is damage to the maternal vascular endothelium, which subsequently manifests as the clinical features of PE. Other than delivery of the fetus and placenta, curative treatments for PE have not yet been forthcoming, which reflects the complexity of the clinical syndrome. A major source of reactive oxygen species that contributes to the widespread maternal vascular endothelium damage is the PE-affected decidua. The role of decidua-derived mesenchymal stem/stromal cells (MSC) in normotensive and pathological placenta development is poorly understood. The ability to respond to an environment of oxidative damage is a "universal property" of MSC but the biological mechanisms that MSC employ in response to oxidative stress are compromised in PE. In this review, we discuss how MSC respond to oxidative stress in normotensive and pathological conditions. We also consider the possibility of manipulating the oxidative stress response of abnormal MSC as a therapeutic strategy to treat preeclampsia.

Circulating Levels of Anti-C1q and Anti-Factor H Autoantibodies and Their Targets in Normal Pregnancy and Preeclampsia

Preeclampsia (PE) generally manifests in the second half of pregnancy with hypertension and proteinuria. The understanding of the origin and mechanism behind PE is incomplete, although there is clearly an immune component to this disorder. The placenta constitutes a complicated immune interface between fetal and maternal cells, where regulation and tolerance are key. Stress factors from placental dysfunction in PE are released to the maternal circulation evoking the maternal response. Several complement factors play a role within this intricate landscape, including C1q in vascular remodeling and Factor H (FH) as the key regulator of alternative pathway complement activation. We hypothesize that decreased levels of C1q or FH, or disturbance of their function by autoantibodies, may be associated with PE. Autoantibodies against C1q and FH and the concentrations of C1q and FH were measured by ELISA in maternal sera from women with preeclamptic and normal pregnancies. Samples originated from cohorts collected in the Netherlands (n=63 PE; n=174 control pregnancies, n=51 nonpregnant), Finland (n=181 PE; n=63 control pregnancies) and Norway (n=59 PE; n=27 control pregnancies). Serum C1q and FH concentrations were higher in control pregnancy than in nonpregnant women. No significant differences were observed for serum C1q between preeclamptic and control pregnancy in any of the three cohorts. Serum levels of FH were lower in preeclamptic pregnancies compared to control pregnancies in two of the cohorts, this effect was driven by the early onset PE cases. Neither anti-C1q autoantibodies nor anti-FH autoantibodies levels differed between women with PE and normal pregnancies. In conclusion, levels of anti-C1q and anti-FH autoantibodies are not increased in PE. C1q and FH are increased in pregnancy, but importantly, a decrease in FH concentration is associated with PE.

MicroRNA-30a contributes to pre-eclampsia through regulating the proliferation, apoptosis, and angiogenesis modulation potential of mesenchymal stem cells by targeting AVEN

Pre-eclampsia (PE) is a pregnancy-associated disease related to an unprecedented hypertension attack. Mesenchymal stem cells (MSCs) play a crucial role in PE pathology. . Our research was designed to illustrate the functions of microRNA-30a (miR-30a) in proliferation, apoptosis, and the potential of regulating angiogenesis in MSCs, and to analyze its potential molecular mechanisms. TargetScan software and the luciferase reporter assay were used to forecast and verify the relationship between miR-30a and AVEN. MiR-30a and AVEN expression in the decidual tissue and decidua (d)MSCs of healthy pregnant women and PE patients were assessed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell proliferation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT), flow cytometry, and transwell assays were used to evaluate cell proliferation, growth, the cell cycle, apoptosis, and migration. Furthermore, the tube formation ability was evaluated using the human umbilical vein endothelial cell (HUVEC) tube formation assay. AVEN is the target gene of miR-30a. MiR-30a was upregulated in decidual tissues and dMSCs of PE patients. However, AVEN was weakly expressed, and AVEN expression was negatively related to miR-30a levels in decidual tissues and dMSCs of PE patients. Compared to the mimic control group, upregulation of miR-30a inhibited dMSC proliferation and cell growth, promoted G0/G1 phase arrest, and induced apoptosis. Furthermore, the miR-30a mimic transfected dMSC culture supernatant suppressed HTR-8/SVneo cell migration ability and HUVEC tube formation ability. However, AVEN reversed these changes. In conclusion, miR-30a/AVEN may serve as a new axis for PE treatment.

Vitamin D stimulates placental L-type amino acid transporter 1 (LAT1) in preeclampsia

Vitamin D insufficiency/deficiency has been linked to an increased risk of preeclampsia. Impaired placental amino acid transport is suggested to contribute to abnormal fetal intrauterine growth in pregnancies complicated by preeclampsia. However, if vitamin D-regulated amino acid transporter is involved in the pathophysiologic mechanism of preeclampsia has not been clarified yet. The aberrant expression of key isoform of L-type amino acid transporter LAT1 was determined by western blot and immunohistochemistry in the placenta from normotensive and preeclamptic pregnancies. The role for vitamin D on placental LAT1 expression was investigated through the exposure of HTR-8/SVneo human trophoblast cells to the biologically active 1,25(OH)₂D₃ and the oxidative stress-inducer cobalt chloride (CoCl₂). Our results showed that placental LAT1 expression was reduced in women with preeclampsia compared to normotensive pregnancies, which was associated with decreased expression of vitamin D receptor (VDR). 1,25(OH)₂D₃ significantly upregulated LAT1 expression in placental trophoblasts, and also prevented the decrease of mTOR activity under CoCl₂-induced oxidative stress. siRNA targeting VDR significantly attenuated 1,25(OH)₂D₃-stimulated LAT1 expression and mTOR signaling activity. Moreover, treatment of rapamycin specifically inhibited the activity of mTOR signaling and resulted in decrease of LAT1 expression. In conclusion, LAT1 expression was downregulated in the placenta from women with preeclampsia. 1,25(OH)₂D₃/VDR could stimulate LAT1 expression, which was likely mediated by mTOR signaling in placental trophoblasts. Regulation on placental amino acid transport may be one of the mechanisms by which vitamin D affects fetal growth in preeclampsia.

Biochemical markers in the pathogenesis of preeclampsia: novel link between placental growth factor and interleukin-6

Preeclampsia (PE) is a multisystem disorder of pregnancy characterized by sudden onset of hypertension and proteinuria. The appearance and diagnosis of the disease remain elusive and the only treatment is the termination of pregnancy. The onset of the disease is preceded by a shift in the balance of the angiogenic and antiangiogenic proteins in the maternal circulation. We surmised that the assessment of the levels of these proteins during pregnancy could lead to a proper diagnosis of the disease. In this study, we determined the levels of angiogenic and antiangiogenic proteins and IL-6 in maternal circulation during normotensive and hypertensive pregnancy, including PE. Serum isolated from pregnant women during antenatal visits was used to determine the concentrations of these proteins. The levels of antiangiogenic proteins, sFlt-1 and sEng, were higher in hypertensive disorders [gestational hypertension (GH), mild PE, and PE] of pregnancy and were significantly higher for PE than for GH. The levels of sFlt-1 and sEng were higher in PE samples compared to those in GH and NT samples. These proteins may have contributed to increased blood pressure. The levels of PlGF were decreased in pregnant women having GH, mild PE, and PE. The levels of the inflammatory intermediate, IL-6, were increased in PE samples compared to those in the GH and normotensive samples. The evaluation of the altered levels of antiangiogenic and angiogenic proteins can be useful for diagnosis of PE.

Mitochondrial dysfunction-induced high hCG associated with development of fetal growth restriction and pre-eclampsia with fetal growth restriction

Fetal growth restriction (FGR) and pre-eclampsia with fetal growth restriction (PE/FGR) are high-risk perinatal diseases that may involve high levels of human chorionic gonadotropin (hCG) and mitochondrial dysfunction. However, little is known about how these factors affect placental function. We investigated how mitochondrial dysfunction and high hCG expression affected placental function in unexplained FGR and PE/FGR. We observed elevated expression of hCGβ and growth differentiation factor 15 mRNA and protein levels in the placenta with both diseases. Likewise, antiangiogenic factors, such as Ang2, IP10, sFlt1, IL8, IL1B, and TNFα, were also upregulated at the mRNA level. In addition, the expression of COXI and COXII which encoded by mitochondrial DNA were significantly decreased in both diseases, suggesting that mitochondrial translation was impaired. Treatment with hCG increased Ang2, IP10, IL8, and TNFα mRNA levels in a dose-dependent manner via the p38 and JNK pathways. Mitochondrial translation inhibitors increased hCGβ expression through stabilization of HIF1α, and increased IL8 and TNFα mRNA expression. These results revealed that high expression of hCG due to mitochondrial translational dysfunction plays an important role in the pathogenesis of FGR and PE/FGR.

SARS- CoV-2 infection and oxidative stress in early-onset preeclampsia

SARS-CoV-2 causes coronavirus disease 2019 (COVID-19) also in pregnant women. Infection in pregnancy leads to maternal and placental functional alterations. Pregnant women with vascular defects such as preeclampsia show high susceptibility to SARS-CoV-2 infection by undefined mechanisms. Pregnant women infected with SARS-CoV-2 show higher rates of preterm birth and caesarean delivery, and their placentas show signs of vasculopathy and inflammation. It is still unclear whether the foetus is affected by the maternal infection with this virus and whether maternal infection associates with postnatal affections. The SARS-CoV-2 infection causes oxidative stress and activation of the immune system leading to cytokine storm and next tissue damage as seen in the lung. The angiotensin-converting-enzyme 2 expression is determinant for these alterations in the lung. Since this enzyme is expressed in the human placenta, SARS-CoV-2 could infect the placenta tissue, although reported to be of low frequency compared with maternal lung tissue. Early-onset preeclampsia (eoPE) shows higher expression of ADAM17 (a disintegrin and metalloproteinase 17) causing an imbalanced renin-angiotensin system and endothelial dysfunction. A similar mechanism seems to potentially account for SARS-CoV-2 infection. This review highlights the potentially common characteristics of pregnant women with eoPE with those with COVID-19. A better understanding of the mechanisms of SARS-CoV-2 infection and its impact on the placenta function is determinant since eoPE/COVID-19 association may result in maternal metabolic alterations that might lead to a potential worsening of the foetal programming of diseases in the neonate, young, and adult.

How Soluble Fms-Like Tyrosine Kinase 1 Could Contribute to Blood-Brain Barrier Dysfunction in Preeclampsia?

Preeclampsia is a pregnancy-related syndrome that courses with severe cerebrovascular complications if not properly managed. Findings from pre-clinical and clinical studies have proposed that the imbalance between pro- and anti-angiogenic factors exhibited in preeclampsia is a major component of its pathophysiology. In this regard, measurement of circulating levels of soluble tyrosine kinase-1 similar to fms (sFlt-1), a decoy receptor for vascular endothelial growth factor (VEGF), is a moderately reliable biomarker for the diagnosis of preeclampsia. However, few studies have established a mechanistic approach to determine how the high levels of sFlt-1 are responsible for the endothelial dysfunction, and even less is known about its effects at the blood-brain barrier (BBB). Since the expression pattern of VEGF receptors type 1 and 2 in brain endothelial cells differs from the observed in peripheral endothelial cells, and components of the neurovascular unit of the BBB provide paracrine secretion of VEGF, this compartmentalization of VEGF signaling could help to see in a different viewpoint the role of sFlt-1 in the development of endothelial dysfunction. In this article, we provide a hypothesis of how sFlt-1 could eventually be a protective factor for brain endothelial cells of the BBB under preeclampsia.

TAGLN2-Regulated Trophoblast Migration, Invasion and Fusion are Impaired in Preeclampsia

Preeclampsia (PE) is a serious disease during pregnancy that affects approximately eight million mothers and infants worldwide each year and is closely related to abnormal trophoblast function. However, research on placental trophoblast functional abnormalities is insufficient, and the etiology of PE is unclear. Here, we report that the expression of transgelin-2 (TAGLN2) was downregulated in the placenta of patients with PE. In addition, a lack of TAGLN2 significantly reduced the ability of trophoblasts to migrate, invade and fuse. A co-immunoprecipitation (Co-IP) and microscale thermophoresis analysis showed that TAGLN2 bound directly to E-cadherin. A decrease in TAGLN2 expression led to a reduction in cleavage of the E-cadherin extracellular domain, thereby regulating the function of trophoblasts. In addition, we found that a reduction in soluble E-cadherin may also have an effect on blood vessel formation in the placenta, which is necessary for normal placental development. What’s more, the in vivo mouse model provided additional evidence of TAGLN2 involvement in the development of PE. By injecting pregnant mice with Ad-TAGLN2, we successfully generated a human PE-like syndrome that resulted in high blood pressure and some adverse pregnancy outcomes. Overall, the association between TAGLN2 and PE gives a new insight into PE diagnosis and treatment.

Procyanidin B2 ameliorates endothelial dysfunction and impaired angiogenesis via the Nrf2/PPARγ/sFlt-1 axis in preeclampsia

Preeclampsia is a severe complication of pregnancy characterized by variable degrees of placental malperfusion. A growing body of evidence indicates that soluble endoglin and soluble fms-like tyrosine kinase-1 (sFlt-1) play important pathophysiological roles in preeclampsia, causing endothelial dysfunction, hypertension, and multiorgan injury. A drug that is safe in pregnancy and inhibits placental sFlt-1 and soluble endoglin secretion would be an attractive treatment strategy for preeclampsia. Procyanidin B2, a bioactive food compound, has been reported to exert multiple beneficial functions. Placental explant cultures in vitro are useful for studying tissue functions including release of secretory components, pharmacology, toxicology, and disease processes. The reduced uterine perfusion pressure (RUPP) rat model has been widely used as a model of preeclampsia. We aimed to investigate the effect of procyanidin B2 on preeclampsia via using placental explant cultures and RUPP rat model. In this study, we demonstrated that procyanidin B2 reduced soluble endoglin and sFlt-1 secretion from human umbilical vein endothelial cells (HUVECs), primary trophoblasts, and placental explants from preeclamptic pregnancies. Moreover, procyanidin B2 alleviated endothelial dysfunction and impaired angiogenesis induced by sFlt-1, including increasing the migration, invasion and angiogenesis of endothelial cells and decreasing the expression of vascular cell adhesion molecule-1 (VCAM-1) and leukocyte adhesion on HUVECs. In addition, procyanidin B2 promoted nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear accumulation and induced peroxisome proliferator-activated receptor γ (PPARγ) expression in primary placental tissues and endothelial cells. Importantly, Nrf2 specifically binds to the PPARγ promoter region (-1227/-1217) and enhances its transcriptional activity. Procyanidin B2 inhibits sFlt-1 secretion via the Nrf2/PPARγ axis. In the RUPP rat model of preeclampsia, procyanidin B2 attenuated RUPP-induced maternal angiogenic imbalance, hypertension and improved placental and fetal weight. Taken together, our results demonstrate that procyanidin B2 inhibits sFlt-1 secretion and ameliorates endothelial dysfunction and impaired angiogenesis via the Nrf2/PPARγ axis in preeclampsia. Procyanidin B2 may be a novel therapeutic agent for treatment of preeclampsia.

The Pivotal Role of the Placenta in Normal and Pathological Pregnancies: A Focus on Preeclampsia, Fetal Growth Restriction, and Maternal Chronic Venous Disease

The placenta is a central structure in pregnancy and has pleiotropic functions. This organ grows incredibly rapidly during this period, acting as a mastermind behind different fetal and maternal processes. The relevance of the placenta extends far beyond the pregnancy, being crucial for fetal programming before birth. Having integrative knowledge of this maternofetal structure helps significantly in understanding the development of pregnancy either in a proper or pathophysiological context. Thus, the aim of this review is to summarize the main features of the placenta, with a special focus on its early development, cytoarchitecture, immunology, and functions in non-pathological conditions. In contraposition, the role of the placenta is examined in preeclampsia, a worrisome hypertensive disorder of pregnancy, in order to describe the pathophysiological implications of the placenta in this disease. Likewise, dysfunction of the placenta in fetal growth restriction, a major consequence of preeclampsia, is also discussed, emphasizing the potential clinical strategies derived. Finally, the emerging role of the placenta in maternal chronic venous disease either as a causative agent or as a consequence of the disease is equally treated.

Hypoxic stress disrupts HGF/Met signaling in human trophoblasts: implications for the pathogenesis of preeclampsia

Background

Preeclampsia (PE), a placenta-associated pregnancy complication, is the leading cause of maternal and perinatal morbidity and mortality. Met/Erk signaling is inhibited in the placentas of patients with early-onset preeclampsia (E-PE), but the underlying mechanisms remain elusive. In this study, the expression modes of Met and endocytic vesicles in normal and preeclamptic placentas were compared. Biotinylation internalization/recycling assays were used to measure the endocytosis of Met under hypoxia and normoxia in HTR8/SVneo cells. In addition, the expression level of Cbl, a specific E3 ligase of Met, was measured under hypoxia and normoxia, and the endocytosis of Met was studied by using confocal microscopy.

Results

We found considerable intracellular accumulation of Met, which was colocalized with caveolin-1 (CAV-1), in trophoblasts from E-PE placentas. Prolonged hypoxic stimulation led to the remarkable augmentation of CAV-1-mediated Met endocytosis in HTR8/SVneo cells. In addition, the expression of Cbl was substantially repressed by sustained hypoxia, disrupting ubiquitin degradation and the subsequent intracellular accumulation of Met in HTR8/SVneo cells. The abnormal degradation of Met hampered the ability of hepatocyte growth factor (HGF) to promote trophoblast cell invasion. In E-PE placentas, aberrant upregulation of CAV-1 and downregulation of Cbl were observed in parallel to the intracellular accumulation of Met.

Conclusions

These findings reveal that prolonged hypoxic stress induces the augmentation of endocytosis and repression of ubiquitin-mediated Met degradation, which leads to the impaired regulation of trophoblast invasion by HGF/Met signaling. These data provide novel evidence for elucidating the pathogenesis of preeclampsia, especially of the early-onset subtype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00791-5.

Perinatal outcomes of singleton live births after preimplantation genetic testing during single frozen-thawed blastocyst transfer cycles: a propensity score-matched study

OBJECTIVE

To determine whether singleton pregnancy achieved after preimplantation genetic testing (PGT) is associated with a higher risk of adverse perinatal outcomes than in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) singleton pregnancy.

DESIGN

A retrospective cohort study.

SETTING

A university-affiliated fertility center.

PATIENT(S)

This cohort study included singleton live births resulting from PGT (n = 232) and IVF/ICSI singleton pregnancies (n = 2,829) with single frozen-thawed blastocyst transfer. Multiple baseline covariates were used for propensity score matching, yielding 214 PGT singleton pregnancies matched to 617 IVF/ICSI singleton pregnancies.

INTERVENTION(S)

Trophectoderm biopsy.

MAIN OUTCOME MEASURE(S)

The primary outcome was gestational hypertension, and various clinical perinatal secondary outcomes related to maternal and neonatal health were measured.

RESULT(S)

Compared with IVF/ICSI singleton pregnancy, PGT singleton pregnancy was associated with a significantly higher risk of gestational hypertension (adjusted odds ratio, 2.58; 95% confidence interval, 1.32, 5.05). In the matched sample, the risk of gestational hypertension remained higher with PGT singleton pregnancy (odds ratio, 2.33; 95% confidence interval, 1.04, 5.22) than with IVF/ICSI singleton pregnancy. No statistical differences were noted in any other measured outcomes between the groups.

CONCLUSION(S)

The perinatal outcomes of PGT and IVF/ICSI singleton pregnancies were similar except for the observed potentially higher risk of gestational hypertension with PGT singleton pregnancy. However, because the data on PGT singleton pregnancies are limited, this conclusion warrants further investigation.

Maternal Adverse Outcomes in Hypertensive Disorders of Pregnancy and Their Association with Serum Adiponectin and Redox Markers

Background: Premature termination of pregnancy because of unmanageable maternal complications in hypertensive disorders of pregnancy (HDP) results in adverse neonatal outcome. Identification of biochemical derangements associated with maternal complications may help in the better medical management of the mother resulting in better neonatal outcomes. Method: Healthy pregnant women (C); pregnant women with gestational hypertension (GH), and preeclampsia (late [LP] and early [EP] onset) were studied. Maternal serum redox markers and adipokines were evaluated for their association with maternal complications. Results: Adiponectin levels were significantly raised in preeclampsia groups when compared with control and GH groups. Univariate and multivariate analysis confirmed that malondialdehyde (MDA) and total antioxidant status (TAS) were associated with eclampsia; adiponectin and TAS with HELLP syndrome; adiponectin, MDA and TAS with severe preeclampsia; and adiponectin with impaired renal function. Conclusion: We identified that increased serum adiponectin, MDA, and TAS were associated with adverse maternal outcomes.

The role of statins in the prevention of preeclampsia

Preeclampsia is a common hypertensive disorder of pregnancy associated with considerable neonatal and maternal morbidities and mortalities. However, the exact cause of preeclampsia remains unknown; it is generally accepted that abnormal placentation resulting in the release of soluble antiangiogenic factors, coupled with increased oxidative stress and inflammation, leads to systemic endothelial dysfunction and the clinical manifestations of the disease. Statins have been found to correct similar pathophysiological pathways that underlie the development of preeclampsia. Pravastatin, specifically, has been reported in various preclinical and clinical studies to reverse the pregnancy-specific angiogenic imbalance associated with preeclampsia, to restore global endothelial health, and to prevent oxidative and inflammatory injury. Human studies have found a favorable safety profile for pravastatin, and more recent evidence does not support the previous teratogenic concerns surrounding statins in pregnancy. With reassuring and positive findings from pilot studies and strong biological plausibility, statins should be investigated in large clinical randomized-controlled trials for the prevention of preeclampsia.

Soluble CD146 is increased in preeclampsia and interacts with galectin-1 to regulate trophoblast migration through VEGFR2 receptor

OBJECTIVE

To explore the regulatory role of soluble CD146 (sCD146) and its interaction with galectin-1 (Gal1) in placenta-mediated complications of pregnancy.

DESIGN

Prospective pilot and experimental studies.

SETTING

University-affiliated hospital and academic research laboratory.

PATIENT(S)

One hundred fifteen women divided into three groups: 30 healthy, nonpregnant women, 50 women with normal pregnancies, and 35 with placenta-mediated pregnancy complications.

INTERVENTION(S)

Wound-healing experiments were conducted to study trophoblast migration.

MAIN OUTCOME MEASURE(S)

Quantification of sCD146 and Gal1 by enzyme-linked immunosorbent assay. Analysis of trophoblast migration by wound closure.

RESULT(S)

Concomitant detection of sCD146 and Gal1 showed lower sCD146 and higher Gal1 concentrations in women with normal pregnancies compared with nonpregnant women. In addition, follow-up of these women revealed a decrease in sCD146 associated with an increase in Gal1 throughout pregnancy. In contrast, in women with preeclampsia, we found significantly higher sCD146 concentrations compared with women with normal pregnancies and no modification of Gal1. We emphasize the opposing effects of sCD146 and Gal, since, unlike Gal1, sCD146 inhibits trophoblast migration. Moreover, the migratory effect of Gal1 was abrogated with the use of an anti-CD146 blocking antibody or the use of small interfering RNA to silence VEGFR2 expression. This suggests that trophoblast migration is mediated though the interaction of Gal1 with CD146, further activating the VEGFR2 signaling pathway. Significantly, sCD146 blocked the migratory effects of Gal1 on trophoblasts and inhibited its secretion, suggesting that sCD146 acts as a ligand trap.

CONCLUSION(S)

Soluble CD146 could be proposed as a biomarker in preeclampsia and a potential therapeutic target.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 01736826.

Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

First trimester preeclampsia screening and prediction

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality. Early-onset disease requiring preterm delivery is associated with a higher risk of complications in both mothers and babies. Evidence suggests that the administration of low-dose aspirin initiated before 16 weeks' gestation significantly reduces the rate of preterm preeclampsia. Therefore, it is important to identify pregnant women at risk of developing preeclampsia during the first trimester of pregnancy, thus allowing timely therapeutic intervention. Several professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) and National Institute for Health and Care Excellence (NICE) have proposed screening for preeclampsia based on maternal risk factors. The approach recommended by ACOG and NICE essentially treats each risk factor as a separate screening test with additive detection rate and screen-positive rate. Evidence has shown that preeclampsia screening based on the NICE and ACOG approach has suboptimal performance, as the NICE recommendation only achieves detection rates of 41% and 34%, with a 10% false-positive rate, for preterm and term preeclampsia, respectively. Screening based on the 2013 ACOG recommendation can only achieve detection rates of 5% and 2% for preterm and term preeclampsia, respectively, with a 0.2% false-positive rate. Various first trimester prediction models have been developed. Most of them have not undergone or failed external validation. However, it is worthy of note that the Fetal Medicine Foundation (FMF) first trimester prediction model (namely the triple test), which consists of a combination of maternal factors and measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has undergone successful internal and external validation. The FMF triple test has detection rates of 90% and 75% for the prediction of early and preterm preeclampsia, respectively, with a 10% false-positive rate. Such performance of screening is superior to that of the traditional method by maternal risk factors alone. The use of the FMF prediction model, followed by the administration of low-dose aspirin, has been shown to reduce the rate of preterm preeclampsia by 62%. The number needed to screen to prevent 1 case of preterm preeclampsia by the FMF triple test is 250. The key to maintaining optimal screening performance is to establish standardized protocols for biomarker measurements and regular biomarker quality assessment, as inaccurate measurement can affect screening performance. Tools frequently used to assess quality control include the cumulative sum and target plot. Cumulative sum is a sensitive method to detect small shifts over time, and point of shift can be easily identified. Target plot is a tool to evaluate deviation from the expected multiple of median and the expected median of standard deviation. Target plot is easy to interpret and visualize. However, it is insensitive to detecting small deviations. Adherence to well-defined protocols for the measurements of mean arterial pressure, uterine artery pulsatility index, and placental growth factor is required. This article summarizes the existing literature on the different methods, recommendations by professional organizations, quality assessment of different components of risk assessment, and clinical implementation of the first trimester screening for preeclampsia.

Puerarin attenuates preeclampsia-induced trophoblast mobility loss and inflammation by modulating miR-181b-5p/RBAK axis

PROBLEM

Preeclampsia (PE) is a serious pregnancy complication characterized by inflammation and impaired trophoblast motility. Puerarin (Pue) is a functional compound with anti-PE potential. The current study aimed to explore the therapeutic effects of Pue on PE as well as the associated mechanism by focusing on the interaction between Pue and microRNAs (miRs).

METHODS OF STUDY

Human villous trophoblast HTR-8/SVneo cells were treated with TNF-α and Pue, and a change in miR expression profile was determined. The anti-PE effects of Pue were validated in rat models by measuring blood pressure, 24-h proteinuria, and cytokine levels. The mechanism was explored by focusing on miR-181b-5p/RBAK axis.

RESULTS

The induction of PE increased blood pressure and 24-h proteinuria, and induced TNF-α, IL-1β, and IL-6 levels, which was reversed by Pue. In in vitro assays, TNF-α suppressed viability, induced apoptosis and inflammatory response, and inhibited migration in trophoblasts, which was attenuated by Pue. At molecular level, the expression level of miR-181b-5p was both induced in vivo and in vitro with the development of PE symptoms, contributing to the inhibited expression of RBAK. The induced expression of miR-181b-5p under Pue treatment showed that the reinduction of miR-181b-5p counteracted the effects of Pue, indicating the key role of the miR in the protective effects of Pue against PE.

CONCLUSIONS

The current study verified the anti-PE function of Pue: the compound suppressed inflammatory response associated with PE, and improved trophoblast motility. The effects depended on the inhibition of miR-181b-5p that inhibited the expression of RBAK.

Chronic hypertension and superimposed preeclampsia: screening and diagnosis

Superimposed preeclampsia complicates about 20% of pregnancies in women with chronic hypertension and is associated with increased maternal and perinatal morbidity compared with preeclampsia alone. Distinguishing superimposed preeclampsia from chronic hypertension can be challenging because, in chronic hypertension, the traditional criteria for the diagnosis of preeclampsia, hypertension, and significant proteinuria can often predate the pregnancy. Furthermore, the prevalence of superimposed preeclampsia is unlikely to be uniformly distributed across this high-risk group but is related to the severity of preexisting endothelial dysfunction. This has led to interest in identifying biomarkers that could help in screening and diagnosis of superimposed preeclampsia and in the stratification of risk in women with chronic hypertension. Elevated levels of uric acid and suppression of other renal biomarkers, such as the renin-angiotensin aldosterone system, have been demonstrated in women with superimposed preeclampsia but perform only modestly in its prediction. In addition, central to the pathogenesis of preeclampsia is a tendency toward an antiangiogenic state thought to be triggered by an impaired placenta and, ultimately, contributing to the endothelial dysfunction pathognomonic of the disease. In the general obstetrical population, angiogenic factors, such as soluble fms-like tyrosine kinase-1 and placental growth factor, have shown promise in the prediction of preeclampsia. However, soluble fms-like tyrosine kinase-1 and placental growth factor are impaired in women with chronic hypertension irrespective of whether they develop superimposed preeclampsia. Therefore, the differences in levels are less discriminatory in the prediction of superimposed preeclampsia compared with the general obstetrical population. Alternative biomarkers to the angiogenic and renal factors include those of endothelial dysfunction. A characteristic of both preeclampsia and chronic hypertension is an exaggerated systemic inflammatory response causing or augmenting endothelial dysfunction. Thus, proinflammatory mediators, such as tumor necrosis factor-α, interleukin-6, cell adhesion molecules, and endothelin, have been investigated for their role in the screening and diagnosis of superimposed preeclampsia in women with chronic hypertension. To date, the existing limited evidence suggests that the differences between those who develop superimposed preeclampsia and those who do not are, as with angiogenic factors, also modest and not clinically useful for the stratification of women with chronic hypertension. Finally, pro-B-type natriuretic peptide is regarded as a sensitive marker of early cardiac dysfunction that, in women with chronic hypertension, may predate the pregnancy. Thus, it has been proposed that pro-B-type natriuretic peptide could give insight as to the ability of women with chronic hypertension to adapt to the hemodynamic requirements of pregnancy and, subsequently, their risk of developing superimposed preeclampsia. Although higher levels of pro-B-type natriuretic peptide have been demonstrated in women with superimposed preeclampsia compared with those without, current evidence suggests that pro-B-type natriuretic peptide is not a predictor for the disease. The objectives of this review are to, first, discuss the current criteria for the diagnosis of superimposed preeclampsia and, second, to summarize the evidence for these potential biomarkers that may assist in the diagnosis of superimposed preeclampsia.

Decidualization resistance in the origin of preeclampsia

Preeclampsia is a major obstetrical complication with short- and long-term life-threatening consequences for both mother and child. Shallow cytotrophoblast invasion through the uterine decidua into the spiral arteries is implicated in the pathogenesis of preeclampsia, although the cause of deficient arterial invasion remains unknown. Research that is focused on the "soil"-the maternal decidua-highlights the importance of this poorly understood but influential uterine layer. Decidualization of endometrial cells regulates embryo invasion, which is essential for spiral artery remodeling and establishing the maternal-fetal interface. Exploration of the association between impaired decidualization and preeclampsia revealed suboptimal endometrial maturation and uterine natural killer cells present in the decidua before preeclampsia development. Furthermore, decidualization defects in the endometrium of women with severe preeclampsia, characterized by impaired cytotrophoblast invasion, were detected at the time of delivery and persisted 5 years after the affected pregnancy. Recently, a maternal deficiency of annexin A2 expression was found to influence aberrant decidualization and shallow cytotrophoblast invasion, suggesting that decidualization resistance, which is a defective endometrial cell differentiation during the menstrual cycle, could underlie shallow trophoblast invasion and the poor establishment of the maternal-fetal interface. Based on these findings, the transcriptional signature in the endometrium that promotes decidualization deficiency could be detected before (or after) conception. This would serve to identify women at risk of developing severe preeclampsia and aid the development of therapies focused on improving decidualization, perhaps also preventing severe preeclampsia. Here, we discuss decidualization deficiency as a contributor to the pathogenesis of pregnancy disorders with particular attention to severe preeclampsia. We also review current diagnostic strategies and discuss future directions in diagnostic methods based on decidualization.

Effect of Placenta-Derived Mesenchymal Stromal Cells Conditioned Media on an LPS-Induced Mouse Model of Preeclampsia

We tested the pro-angiogenic and anti-inflammatory effects of human placenta-derived mesenchymal stromal cells (hPDMSCs)-derived conditioned media (CM) on a mouse model of preeclampsia (PE), a severe human pregnancy-related syndrome characterized by maternal hypertension, proteinuria, endothelial damage, inflammation, often associated with fetal growth restriction (FGR). At d11 of pregnancy, PE was induced in pregnant C57BL/6N mice by bacterial lipopolysaccharide (LPS) intravenous injection. At d12, 300 μL of unconditioned media (control group) or 300 μL PDMSCs-CM (CM group) were injected. Maternal systolic blood pressure was measured from 9 to 18 days of pregnancy. Urine protein content were analyzed at days 12, 13, and 17 of pregnancy. At d19, mice were sacrificed. Number of fetuses, FGR, fetal reabsorption, and placental weight were evaluated. Placentae were analyzed for sFlt-1, IL-6, and TNF-α gene and protein expressions. No FGR and/or reabsorbed fetuses were delivered by PDMSCs-CM-treated PE mice, while five FGR fetuses were found in the control group accompanied by a lower placental weight. PDMSCs-CM injection significantly decreased maternal systolic blood pressure, proteinuria, sFlt-1, IL-6, and TNF-α levels in PE mice. Our data indicate that hPDMSCs-CM can reverse PE-like features during pregnancy, suggesting a therapeutic role for hPDMSCs for the treatment of preeclampsia.

Dysregulated GLUT1 may be involved in the pathogenesis of preeclampsia by impairing decidualization

Preeclampsia (PE), a hypertensive complication in pregnancy, is a major contributor to maternal and fetal morbidity and mortality. PE has long been regarded a heterogeneous disorder with a pathogenesis that involves multiple genes and factors. Glucose transporter 1 (GLUT1) is a central rate-limiting pump that is involved in glucose uptake and subsequent utilization. Our previous RNA-seq results demonstrated GLUT1 was significantly downregulated in deciduas from patients with severe PE. Therefore, in this study, we aimed to explore the role of GLUT1 in the occurrence of PE. Our data showed that mRNA and protein levels of GLUT1 were significantly downregulated in the deciduas from patients with severe PE. Additionally, GLUT1 levels were substantially upregulated in human endometrial stromal cells (HESCs) during in vitro decidualization. Moreover, GLUT1 knockdown significantly reduced the mRNA levels of decidualization markers (IGFBP1 and PRL) and aerobic glycolysis-related genes (LDHA and MCT4), as well as decreased glucose uptake and lactate production. Furthermore, upon GLUT1 knockdown, the levels of apoptotic genes P53, P21, and BAX increased whereas the level of BCL2 decreased. Target prediction results and luciferase analysis showed that GLUT1 is one of the targets of miR-140-5p, which is partly responsible for downregulated GLUT1 levels. Collectively, these results demonstrate that GLUT1 exerts a pivotal role in human decidualization by participating in glycolysis, and that GLUT1 deficiency may trigger aberrant glycolysis, thereby leading to destructive decidualization that may impede blastocyst implantation, trophoblast invasion, and subsequent placental development, which are associated with PE. Taken together, these data suggest that GLUT1 might be a promising target for PE therapy.

Manipulating CD4+ T Cell Pathways to Prevent Preeclampsia

Preeclampsia (PreE) is a placental disorder characterized by hypertension (HTN), proteinuria, and oxidative stress. Individuals with PreE and their children are at an increased risk of serious short- and long-term complications, such as cardiovascular disease, end-organ failure, HTN, neurodevelopmental disorders, and more. Currently, delivery is the only cure for PreE, which remains a leading cause of morbidity and mortality among pregnant individuals and neonates. There is evidence that an imbalance favoring a pro-inflammatory CD4+ T cell milieu is associated with the inadequate spiral artery remodeling and subsequent oxidative stress that prime PreE's clinical symptoms. Immunomodulatory therapies targeting CD4+ T cell mechanisms have been investigated for other immune-mediated inflammatory diseases, and the application of these prevention tactics to PreE is promising, as we review here. These immunomodulatory therapies may, among other things, decrease tumor necrosis factor alpha (TNF-α), cytolytic natural killer cells, reduce pro-inflammatory cytokine production [e.g. interleukin (IL)-17 and IL-6], stimulate regulatory T cells (Tregs), inhibit type 1 and 17 T helper cells, prevent inappropriate dendritic cell maturation, and induce anti-inflammatory cytokine action [e.g. IL-10, Interferon gamma (IFN-γ)]. We review therapies including neutralizing monoclonal antibodies against TNF-α, IL-17, IL-6, and CD28; statins; 17-hydroxyprogesterone caproate, a synthetic hormone; adoptive exogenous Treg therapy; and endothelin-1 pathway inhibitors. Rebalancing the maternal inflammatory milieu may allow for proper spiral artery invasion, placentation, and maternal tolerance of foreign fetal/paternal antigens, thereby combatting early PreE pathogenesis.

Placental Dysfunction in Assisted Reproductive Pregnancies: Perinatal, Neonatal and Adult Life Outcomes

Obstetric and newborn outcomes of assisted reproductive technology (ART) pregnancies are associated with significative prevalence of maternal and neonatal adverse health conditions, such as cardiovascular and metabolic diseases. These data are interpreted as anomalies in placentation involving a dysregulation of several molecular factors and pathways. It is not clear which extent of the observed placental alterations are the result of ART and which originate from infertility itself. These two aspects probably act synergically for the final obstetric risk. Data show that mechanisms of inappropriate trophoblast invasion and consequent altered vascular remodeling sustain several clinical conditions, leading to obstetric and perinatal risks often found in ART pregnancies, such as preeclampsia, fetal growth restriction and placenta previa or accreta. The roles of factors such as VEGF, GATA3, PIGF, sFLT-1, sEndoglin, EGFL7, melatonin and of ART conditions, such as short or long embryo cultures, trophectoderm biopsy, embryo cryopreservation, and supraphysiologic endometrium preparation, are discussed. Inflammatory local conditions and epigenetic influence on embryos of ART procedures are important research topics since they may have important consequences on obstetric risk. Prevention and treatment of these conditions represent new frontiers for clinicians and biologists involved in ART, and synergic actions with researchers at molecular levels are advocated.

ceRNA Network and Functional Enrichment Analysis of Preeclampsia by Weighted Gene Coexpression Network Analysis

BACKGROUND

Preeclampsia (PE) is a multisystemic syndrome which has short- and long-term risk to mothers and children and has pluralistic etiology.

OBJECTIVE

This study is aimed at constructing a competitive endogenous RNA (ceRNA) network for pathways most related to PE using a data mining strategy based on weighted gene coexpression network analysis (WGCNA).

METHODS

We focused on pathways involving hypoxia, angiogenesis, and epithelial mesenchymal transition according to the gene set variation analysis (GSVA) scores. The gene sets of these three pathways were enriched by gene set enrichment analysis (GSEA). WGCNA was used to study the underlying molecular mechanisms of the three pathways in the pathogenesis of PE by analyzing the relationship among pathways and genes. The soft threshold power (β) and topological overlap matrix allowed us to obtain 15 modules, among which the red module was chosen for the downstream analysis. We chose 10 hub genes that satisfied ∣log2Fold Change | >2 and had a higher degree of connectivity within the module. These candidate genes were subsequently confirmed to have higher gene significance and module membership in the red module. Coexpression networks were established for the hub genes to unfold the connection between the genes in the red module and PE. Finally, ceRNA networks were constructed to further clarify the underlying molecular mechanism involved in the occurrence of PE. 56 circRNAs, 17 lncRNAs, and 20 miRNAs participated in the regulation of the hub genes. Coagulation factor II thrombin receptor (F2R) and lumican (LUM) were considered the most relevant genes, and ceRNA networks of them were constructed.

CONCLUSION

The microarray data mining process based on bioinformatics methods constructed lncRNA and miRNA networks for ten hub genes that were closely related to PE and focused on ceRNAs of F2R and LUM finally. The results of our study may provide insight into the mechanisms underlying PE occurrence.

Estrogen-Induced Uterine Vasodilation in Pregnancy and Preeclampsia

Normal pregnancy is associated with dramatically increased estrogen biosynthesis whose role is believed to raise uterine blood flow to facilitate the bi-directional maternal-fetal exchanges of gases (O₂ and CO₂), to deliver nutrients, and exhaust wastes to support fetal development and survival. Constrained uterine blood flow in pregnancy is a leading cause of preeclampsia with fetal growth restriction, rendering investigations of uterine hemodynamics to hold a high promise to inform pathways as targets for therapeutic interventions for preeclampsia. The mechanisms of estrogen-induced uterine vasodilation in pregnancy have long been attributed to enhanced endothelium production of nitric oxide, but clinical trials targeting this pathway that dominates uterine hemodynamics have achieved no to little success. Emerging evidence has recently shown a novel proangiogenic vasodilatory role of hydrogen sulfide in regulating uterine hemodynamics in pregnancy and preeclampsia, provoking a new field of perinatal research in searching for alternative pathways for pregnancy disorders especially preeclampsia and intrauterine growth restriction. This minireview is intended to summarize the nitric oxide pathway and to discuss the emerging hydrogen sulfide pathway in modulating estrogen-induced uterine vasodilation in pregnancy and preeclampsia.

RNA profiles reveal signatures of future health and disease in pregnancy

Maternal morbidity and mortality continue to rise, and pre-eclampsia is a major driver of this burden1. Yet the ability to assess underlying pathophysiology before clinical presentation to enable identification of pregnancies at risk remains elusive. Here we demonstrate the ability of plasma cell-free RNA (cfRNA) to reveal patterns of normal pregnancy progression and determine the risk of developing pre-eclampsia months before clinical presentation. Our results centre on comprehensive transcriptome data from eight independent prospectively collected cohorts comprising 1,840 racially diverse pregnancies and retrospective analysis of 2,539 banked plasma samples. The pre-eclampsia data include 524 samples (72 cases and 452 non-cases) from two diverse independent cohorts collected 14.5 weeks (s.d., 4.5 weeks) before delivery. We show that cfRNA signatures from a single blood draw can track pregnancy progression at the placental, maternal and fetal levels and can robustly predict pre-eclampsia, with a sensitivity of 75% and a positive predictive value of 32.3% (s.d., 3%), which is superior to the state-of-the-art method2. cfRNA signatures of normal pregnancy progression and pre-eclampsia are independent of clinical factors, such as maternal age, body mass index and race, which cumulatively account for less than 1% of model variance. Further, the cfRNA signature for pre-eclampsia contains gene features linked to biological processes implicated in the underlying pathophysiology of pre-eclampsia.

Cellular immune responses in the pathophysiology of preeclampsia

Preeclampsia, defined as new-onset hypertension accompanied by proteinuria occurring at 20 weeks of gestation or later, is a leading cause of perinatal morbidity and mortality worldwide. The pathophysiology of this major multi-systemic syndrome includes defective deep placentation, oxidative stress, endothelial dysfunction, the presence of an anti-angiogenic state, and intravascular inflammation, among others. In this review, we provide a comprehensive overview of the cellular immune responses involved in the pathogenesis of preeclampsia. Specifically, we summarize the role of innate and adaptive immune cells in the maternal circulation, reproductive tissues, and at the maternal-fetal interface of women affected by this pregnancy complication. The major cellular subsets involved in the pathogenesis of preeclampsia are regulatory T cells, effector T cells, NK cells, monocytes, macrophages, and neutrophils. We also summarize the literature on those immune cells that have been less characterized in this clinical condition, such as γδ T cells, invariant natural killer T cells, dendritic cells, mast cells, and B cells. Moreover, we discuss in vivo studies utilizing a variety of animal models of preeclampsia to further support the role of immune cells in this disease. Finally, we highlight the existing gaps in knowledge of the immunobiology of preeclampsia that require further investigation. The goal of this review is to promote translational research leading to clinically relevant strategies that can improve adverse perinatal outcomes resulting from the obstetrical syndrome of preeclampsia.

Clinical tools and biomarkers to predict preeclampsia

Preeclampsia is pregnancy-specific, and significantly contributes to maternal, and perinatal morbidity and mortality worldwide. An effective predictive test for preeclampsia would facilitate early diagnosis, targeted surveillance and timely delivery; however limited options currently exist. A first-trimester screening algorithm has been developed and validated to predict preterm preeclampsia, with poor utility for term disease, where the greatest burden lies. Biomarkers such as sFlt-1 and placental growth factor are also now being used clinically in cases of suspected preterm preeclampsia; their high negative predictive value enables confident exclusion of disease in women with normal results, but sensitivity is modest. There has been a concerted effort to identify potential novel biomarkers that might improve prediction. These largely originate from organs involved in preeclampsia's pathogenesis, including placental, cardiovascular and urinary biomarkers. This review outlines the clinical imperative for an effective test and those already in use and summarises current preeclampsia biomarker research.

Role of GRK2 in Trophoblast Necroptosis and Spiral Artery Remodeling: Implications for Preeclampsia Pathogenesis

Impaired invasion of extravillous trophoblasts and severe oxidative stress manifest the poor placentation in preeclampsia, which is life-threatening and more than a hypertensive disease of pregnancy. Previous studies have reported that G protein-coupled receptor kinases (GRKs) play a key role in initiating hypertension and hypertensive renal damage, yet little evidence so far suggests a link between GRKs and preeclampsia-related hypertension. Here, we demonstrate GRK2 expression is significantly downregulated (P < 0.0001) in preeclamptic placentae compared to normotensive controls. Knockdown or inhibition of GRK2 in placentae caused insufficient arterial remodeling and elevated trophoblast necroptosis in vivo. These further induced preeclampsia-like phenotype in mice: hypertension, proteinuria, and elevated pro-angiogenic cytokines. By human extra-villous invasive trophoblast cell line (HTR8/SVneo cells), we revealed the knockdown or inhibition of GRK2 triggered excessive death with typical necroptotic characteristics: nuclear envelope rupture and the activation of RIPK1, RIPK3, and MLKL. Necrostatin-1, an inhibitor of RIPK1, is able to restore the survival of trophoblasts. Together, our findings demonstrated that insufficient GRK2 activity compromises spiral artery remodeling and initiates necrotic events in placentae, thereby leading to preeclampsia. These findings advance our understanding of GRK2 in the pathogenesis of preeclampsia and could shed light on a potential treatment for preeclampsia.

The Role of Type I and Type II NKT Cells in Materno-Fetal Immunity

NKT cells represent a small but significant immune cell population as being a part of and bridging innate and adaptive immunity. Their ability to exert strong immune responses via cytotoxicity and cytokine secretion makes them significant immune effectors. Since pregnancy requires unconventional maternal immunity with a tolerogenic phenotype, investigation of the possible role of NKT cells in materno-fetal immune tolerance mechanisms is of particular importance. This review aims to summarize and organize the findings of previous studies in this field. Data and information about NKT cells from mice and humans will be presented, focusing on NKT cells characteristics during normal pregnancy in the periphery and at the materno-fetal interface and their possible involvement in female reproductive failure and pregnancy complications with an immunological background.

Association of IL1R1 gene (SNP rs2071374) with the risk of preeclampsia

BACKGROUND

Association of IL1R1rs2071374 with the risk of preeclampsia compared with normotensive pregnant women.

METHODOLOGY

The study was a case-control study with 304 pregnant women comprising of preeclampsia (n = 152) and normotensive pregnancies (n = 152). And SNP rs2071374 was genotyped by PCR-RFLP method.

RESULTS

The presence of IL1R1rs2071374G allele was associated with the increased risk of preeclampsia P = 0.01741, odds ratio = 0.7006 (95% CI: 0.5023-0.9759).

CONCLUSION

The results indicated that there was an association in IL1R1 rs2071374SNP with preeclampsia compared to non-preeclampsia women. It is the first study to evaluate that IL1R1 polymorphism is correlated with preeclampsia pathogenesis in the Population in India.

Contribution of -1031T/C and -376G/A tumor necrosis factor alpha polymorphisms and haplotypes to preeclampsia risk in Tunisia (North Africa)

Preeclampsia is a gestational disorder characterized by hypertension and proteinuria. Excessive release of pro-inflammatory cytokines, particularly tumour necrosis factor-alpha, has been demonstrated to contribute to endothelial activation and poor trophoblast invasion in placental development, resulting in preeclampsia's clinical symptoms. Genetic polymorphisms of tumour necrosis factor-alpha can regulate its production and may play an important role in the pathogenesis of this disease. This study aimed to evaluate the association of five tumour necrosis factor-alpha gene promoter single nucleotide polymorphisms, or their haplotype combinations, with preeclampsia prevalence. This case-control study was conducted on 300 women with preeclampsia and 300 age-matched women with normal pregnancy from Tunisian hospitals. Genotyping of tumour necrosis factor-alpha -1031 T/C, -376 G/A, -308 G/A, -238 G/A, and +489 G/A SNPs was performed on DNA extracted from blood samples using PCR-restriction fragment-length polymorphism analysis. Statistical analysis was performed using the chi-square test. P < 0.01 were considered statistically significant to take into consideration the multiple comparisons. A significantly higher frequency of the minor allele -1031C (p < 0.001) was observed in preeclampsia cases compared to controls. Notably, the -1031C and -376A (CA) haplotype, which correlates with a higher production of TNF-α protein, had a higher incidence in women with preeclampsia (p = 0.0005). Conversely, the TG haplotype had a low frequency in preeclampsia cases compared to controls (p = 0.002) which suggests that it is associated with a reduced incidence of preeclampsia. These results suggest that tumour necrosis factor-alpha polymorphisms, in particular the -1031C/A, and the haplotype CA, contribute to an increased risk of preeclampsia in Tunisian women.

The Complement System, T Cell Response, and Cytokine Shift in Normotensive versus Pre-Eclamptic and Lupus Pregnancy

Successful pregnancy requires an immunological shift with T helper CD4⁺ bias based on disbalance Th1/Th17 versus Th2/T regulatory (Tregs) required to induce tolerance against the semi-allogeneic fetus and placenta and to support fetal growth. Considered a pregnancy-specific hypertensive disorder, pre-eclampsia is characterized by multifaceted organ involvement related to impaired maternal immune tolerance to paternal antigens triggered by hypoxic placental injury as well as excessive local and systemic anti-angiogenic and inflammatory factor synthesis. Both systemic and local Th1/Th2 shift further expands to Th17 cells and their cytokines (IL-17) complemented by suppressive Treg and Th2 cytokines (IL-10, IL-4); alterations in Th17 and Tregs cause hypertension during pregnancy throughout vasoactive factors and endothelial dysfunction, providing an explanatory link between immunological and vascular events in the pathobiology of pre-eclamptic pregnancy. Apart from immunological changes representative of normotensive pregnancy, lupus pregnancy is generally defined by higher serum pro-inflammatory cytokines, lower Th2 polarization, defective and lower number of Tregs, potential blockade of complement inhibitors by anti-phospholipid antibodies, and similar immune alterations to those seen in pre-eclampsia. The current review underpins the immune mechanisms of pre-eclampsia focusing on local (placental) and systemic (maternal) aberrant adaptive and innate immune response versus normotensive pregnancy and pregnancy in systemic autoimmune conditions, particularly lupus.

Impaired Sphingosine-1-Phosphate Synthesis Induces Preeclampsia by Deactivating Trophoblastic YAP (Yes-Associated Protein) Through S1PR2 (Sphingosine-1-Phosphate Receptor-2)-Induced Actin Polymerizations

Incomplete spiral artery remodeling, caused by impaired extravillous trophoblast invasion, is a fundamental pathogenic process associated with malplacentation and the development of preeclampsia. Nevertheless, the mechanisms controlling this regulation of trophoblast invasion are largely unknown. We report that sphingosine-1-phosphate synthesis and expression is abundant in healthy trophoblast, whereas in pregnancies complicated by preeclampsia the placentae are associated with reduced sphingosine-1-phosphate and lower SPHK1 (sphingosine kinase 1) expression and activity. In vivo inhibition of sphingosine kinase 1 activity during placentation in pregnant mice led to decreased placental sphingosine-1-phosphate production and defective placentation, resulting in a preeclampsia phenotype. Moreover, sphingosine-1-phosphate increased HTR8/SVneo (immortalized trophoblast cells) cell invasion in a Hippo-signaling-dependent transcriptional coactivator YAP (Yes-associated protein) dependent manner, which is activated by S1PR2 (sphingosine-1-phosphate receptor-2) and downstream RhoA/ROCK induced actin polymerization. Mutation-based YAP-5SA demonstrated that sphingosine-1-phosphate activation of YAP could be either dependent or independent of Hippo signaling. Together, these findings suggest a novel pathogenic pathway of preeclampsia via disrupted sphingosine-1-phosphate metabolism and signaling-induced, interrupted actin dynamics and YAP deactivation; this may lead to potential novel intervention targets for the prevention and management of preeclampsia.

A randomized pilot clinical trial of pravastatin versus placebo in pregnant patients at high risk of preeclampsia

BACKGROUND

Preeclampsia remains a major cause of maternal and neonatal morbidity and mortality. Biologic plausibility, compelling preliminary data, and a pilot clinical trial support the safety and utility of pravastatin for the prevention of preeclampsia.

OBJECTIVE

We previously reported the results of a phase I clinical trial using a low dose (10 mg) of pravastatin in high-risk pregnant women. Here, we report a follow-up, randomized trial of 20 mg pravastatin versus placebo among pregnant women with previous preeclampsia who required delivery before 34+6 weeks' gestation with the objective of evaluating the safety and pharmacokinetic parameters of pravastatin.

STUDY DESIGN

This was a pilot, multicenter, blinded, placebo-controlled, randomized trial of women with singleton, nonanomalous pregnancies at high risk for preeclampsia. Women between 12+0 and 16+6 weeks of gestation were assigned to receive a daily pravastatin dose of 20 mg or placebo orally until delivery. In addition, steady-state pravastatin pharmacokinetic studies were conducted in the second and third trimesters of pregnancy and at 4 to 6 months postpartum. Primary outcomes included maternal-fetal safety and pharmacokinetic parameters of pravastatin during pregnancy. Secondary outcomes included maternal and umbilical cord blood chemistries and maternal and neonatal outcomes, including rates of preeclampsia and preterm delivery, gestational age at delivery, and birthweight.

RESULTS

Of note, 10 women assigned to receive pravastatin and 10 assigned to receive the placebo completed the trial. No significant differences were observed between the 2 groups in the rates of adverse or serious adverse events, congenital anomalies, or maternal and umbilical cord blood chemistries. Headache followed by heartburn and musculoskeletal pain were the most common side effects. We report the pravastatin pharmacokinetic parameters including pravastatin area under the curve (total drug exposure over a dosing interval), apparent oral clearance, half-life, and others during pregnancy and compare it with those values measured during the postpartum period. In the majority of the umbilical cord and maternal samples at the time of delivery, pravastatin concentrations were below the limit of quantification of the assay. The pregnancy and neonatal outcomes were more favorable in the pravastatin group. All newborns passed their brainstem auditory evoked response potential or similar hearing screening tests. The average maximum concentration and area under the curve values were more than 2-fold higher following a daily 20 mg dose compared with a 10 mg daily pravastatin dose, but the apparent oral clearance, half-life, and time to reach maximum concentration were similar, which is consistent with the previously reported linear, dose-independent pharmacokinetics of pravastatin in nonpregnant subjects.

CONCLUSION

This study confirmed the overall safety and favorable pregnancy outcomes for pravastatin in women at high risk for preeclampsia. This favorable risk-benefit analysis justifies a larger clinical trial to evaluate the efficacy of pravastatin for the prevention of preeclampsia. Until then, pravastatin use during pregnancy remains investigational.

Gestational chronic intermittent hypoxia induces hypertension, proteinuria, and fetal growth restriction in mice

PURPOSE

Pregnant women are predisposed to obstructive sleep apnea (OSA). Based on the fact that OSA is an independent risk factor for hypertension among the general population, we hypothesized that chronic intermittent hypoxia (CIH), as a feature of OSA, may lead to preeclampsia.

METHODS

Pregnant and non-pregnant C57BL/6 J mice were exposed to two conditions of chronic intermittent hypoxia: CIH1 (21-5% O₂ alternations), CIH2 (21-10% O₂ alternations), and room air until day 19.

RESULTS

In non-pregnant mice, compared with their respective baseline values, systolic blood pressure (SBP) started to rise from day 14 in the CIH1 group, and SBP rose until day 19 in the CIH2 group. Compared with the pregnant mice exposed to room air, pregnant mice exposed to CIH1 maintained elevated SBP from day 14, accompanied by proteinuria, fetal and placental growth restriction, and a reduction in the number of fetuses. An imbalance between proangiogenic and antiangiogenic factors and impairment of vascular remodeling existed in the placenta of pregnant mice exposed to CIH1. Maternal serum levels of the soluble form of vascular endothelial growth factor receptor-1 were also significantly increased. Pregnant mice exposed to CIH2 seemed to have milder changes than pregnant mice exposed to CIH1.

CONCLUSION

Our results demonstrated that gestational CIH may induce gestational hypertension, proteinuria, fetal and placental growth restriction as well as impairments in placental angiogenesis and vascular remodeling.

Gestational weight gain in twin gestations and pregnancy outcomes: a systematic review and meta-analysis

BACKGROUND

Data on the association of inappropriate gestational weight gain (GWG) and adverse outcomes in twin pregnancies are limited and inconsistent.

OBJECTIVES

To perform a systematic review and meta-analysis on the association between GWG and adverse outcomes in twin pregnancies.

SEARCH STRATEGY

Ovid, Medline, EMBASE and Cochrane Central databases from 1 January 1990 until 23 September 2020.

SELECTION CRITERIA

Interventional and observational studies evaluating the association between GWG and adverse outcomes in twin pregnancies.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers. Summary odds ratios (OR) were calculated using a random-effects model in a subset of studies that analysed GWG as a categorical variable in relation to the Institute of Medicine (IOM) recommendations. The primary outcome was preterm birth.

MAIN RESULTS

From 277 citations, 19 studies involving 36 023 women with twin pregnancies were included in the qualitative analysis, of which 14 were included in the meta-analysis. Overall, 56.8% of women experienced inappropriate GWG: 35.4% (95% CI 30.0-41.0%) gained weight below and 21.4% (95% CI 14.2-29.5%) gained weight above IOM recommendations. Compared with GWG within IOM guidelines, GWG below IOM guidelines was associated with preterm birth before 32 weeks of gestation (OR 3.38; 95% CI 2.05-5.58), and a reduction in the risk of pre-eclampsia (OR 0.68; 95% CI 0.48-0.97). GWG above IOM guidelines was associated with an increased risk of pre-eclampsia that was consistent across all body mass index categories.

CONCLUSIONS

Inappropriate GWG affects over half of twin pregnancies, so is a common and potentially modifiable risk factor for preterm birth and pre-eclampsia.

Biomarkers of Inflammation and Redox Imbalance in Umbilical Cord in Pregnancies with and without Preeclampsia and Consequent Perinatal Outcomes

OBJECTIVE

To compare redox imbalance and inflammation biomarkers in umbilical cords from pregnancies with and without preeclampsia (PE) and to analyse their relationships with perinatal outcomes.

METHODS

A controlled cross-sectional study was conducted in Maceió, Alagoas, Brazil, that involved pregnant women with PE and a group of women without the disease, through the application of a standardized questionnaire. After delivery, umbilical cord samples were collected to measure antioxidant defense, products from oxidative damage, and inflammation biomarkers such as myeloperoxidase (MPO), interleukin- (IL-) 6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α). Statistical analyses were performed using Stata version 13.0 software and IBM Statistical Package for the Social Sciences (SPSS) 20.0, adopting a 95% confidence level (α = 0.05), with the chi-square test, the Wilcoxon-Mann-Whitney test, and the multinomial and Poisson regression tests.

RESULTS

One hundred PE pregnant women and 50 women without the disease were studied. The umbilical cords from PE pregnancies showed higher levels of reduced glutathione (GSH) (p ≤ 0.001), glutathione peroxidase (GPx) (p = 0.016), and malondialdehyde (MDA) (p = 0.028) and lower levels of IL-6 (p = 0.030) and TNF-α (p ≤ 0.001) than the other group, with some associations among these biomarkers with perinatal outcomes.

CONCLUSION

The higher levels of GSH and GPx, in addition to the lower levels of IL-6 and TNF-α, found in the PE umbilical cord, may result from adaptive mechanisms to maintain the oxidative and inflammatory balance; however, despite these changes, the damage to the cell membranes was not minimized, as the MDA level was higher in women with PE than in women without the disease. This implies that a redox imbalance is present, confirming that other physiological and adaptive mechanisms are being activated to preserve foetal health. Therefore, the present work unveils an important role of the umbilical cord in controlling redox imbalance and inflammation in PE pregnancies. Our results reinforce the necessity for continuous research on GSH as a protective compound for the perinatal outcome, especially in PE women.

Reduced urinary angiotensinogen excretion in preeclampsia

OBJECTIVE

This study evaluated urinary angiotensinogen in preeclampsia.

METHODS

Normal pregnant (n = 57) and preeclamptic patients (n = 31); Normal pregnant (n = 10) and preeclamptic rats (n = 10) were studied. Urinary angiotensinogen and plasma angiotensin II were assayed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Urinary angiotensinogen in preeclampsia patients (2.0 ± 1.1 ng/mg creatinine) was suppressed (*p < 0.05) compared to normal pregnant (2.7 ± 1.5 ng/mg creatinine). Plasma angiotensin II in preeclampsia patients (preeclampsia: 36.2 ± 7; normal pregnant: 48.1 ± 5 fmol/mL) was lower. The similar result was observed in preeclampsia rat model.

CONCLUSIONS

The reduced urinary excretion of angiotensinogen was both in human preeclampsia patients and rat model of preeclampsia.

Lifetime Psychosocial Stress Exposure Associated with Hypertensive Disorders of Pregnancy

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) complicate 5 to 10% of all pregnancies and are a major cause of pregnancy-related morbidity. Exposure to psychosocial stress has been associated with systemic inflammation and adverse birth outcomes in pregnant women. Thus, it is probable that psychosocial stress and inflammation play a role in the development of HDP. The primary objective of this analysis was to determine if a woman's lifetime psychosocial stress exposure was associated with an increased risk of HDP. Additionally, we examined whether serum inflammation was an underlying biological mediator for this relationship.

STUDY DESIGN

A multisite prospective study was conducted in a sociodemographically diverse cohort of 647 pregnant women. At a study visit between 12 and 20^6/7 weeks' gestation, maternal psychosocial stress was assessed with six validated assessments and inflammation was measured via log-transformed serum concentrations of interferon-γ, interleukin (IL)-10, IL-13, IL-6, IL-8, and tumor necrosis factor-α. A composite stress score was calculated for each participant from the six stress assessments. The diagnosis of HDP was abstracted from the medical record and was defined as the presence of gestational hypertension after 20 weeks of pregnancy and/or preeclampsia. The association between composite stress and HDP was determined using binary logistic regression. Inflammation, using the six inflammatory biomarkers, was tested as a potential mediator between stress and HDP.

RESULTS

Participants with higher composite stress scores were more likely to develop HDP (odds ratio [OR]: 1.50, 95% confidence interval [CI]: 1.06-2.12). When adjusted for known risk modifiers, including maternal age, race/ethnicity, parity, pre-pregnancy body mass index, diabetes, chronic hypertension, and smoking during pregnancy, the risk remained unchanged (OR: 1.50, 95% CI: 1.03-2.20). No mediation effect by inflammation was observed.

CONCLUSION

Independent of known risk factors, women exposed to greater composite stress burden across the life course are at increased risk of developing HDP.

KEY POINTS

· This study was conducted to determine if women with high levels of psychosocial stress have differences in risk for hypertensive disorders of pregnancy (HDP).. · Independent of known risk factors, women with increased lifetime psychosocial burden are at higher risk for HDP.. · A model that captures multiple domains of life stress may better predict HDP than a unimodal stress assessment..

Progesterone Induced Blocking Factor Reduces Hypertension and Placental Mitochondrial Dysfunction in Response to sFlt-1 during Pregnancy

Preeclampsia (PE) is characterized by new onset hypertension in association with placental ischemia, reduced fetal weight, elevated soluble fms-like tyrosine kinase-1 (sFlt-1), and placental mitochondrial (mt) dysfunction and oxidative stress (ROS). Progesterone induced blocking factor (PIBF) is a product of progesterone signaling that blocks inflammatory processes and we have previously shown PIBF to lower mean arterial blood pressure (MAP) and sFlt-1 in a rat model of PE. Infusion of sFlt-1 causes hypertension and many characteristics of PE in pregnant rodents, however, its role in causing mt dysfunction is unknown. Therefore, we hypothesize that PIBF will improve mt function and MAP in response to elevated sFlt-1 during pregnancy. We tested our hypothesis by infusing sFlt-1 via miniosmotic pumps in normal pregnant (NP) Sprague-Dawley rats (3.7 μg·kg-1·day-1) on gestation days (GD) 13-19 in the presence or absence of PIBF (2.0 µg/mL) injected intraperitoneally on GD 15 and examined mean arterial blood pressure (MAP) and placental mt ROS on GD 19. sFlt-1 increased MAP to 112 + 2 (n = 11) compared to NP rats (98 + 2 mmHg, n = 15, p < 0.05), which was lowered in the presence of sFlt-1 (100 + 1 mmHg, n = 5, p < 0.05). Placental mtATP was reduced in sFlt-1 infused rats versus NP controls, but was improved with PIBF. Placental mtROS was elevated with sFlt-1 compared to NP controls, but was reduced with PIBF. Sera from NP + sFlt-1 increased endothelial cell mtROS, which was attenuated with PIBF. These data demonstrate sFlt-1 induced HTN during pregnancy reduces placental mt function. Importantly, PIBF improved placental mt function and HTN, indicating the efficacy of improved progesterone signaling as potential therapeutics for PE.