Directed biomechanical compressive forces enhance fusion efficiency in model placental trophoblast cultures

The syncytiotrophoblast is a multinucleated structure that arises from fusion of mononucleated cytotrophoblasts, to sheath the placental villi and regulate transport across the maternal-fetal interface. Here, we ask whether the dynamic mechanical forces that must arise during villous development might influence fusion, and explore this question using in vitro choriocarcinoma trophoblast models. We demonstrate that mechanical stress patterns arise around sites of localized fusion in cell monolayers, in patterns that match computational predictions of villous morphogenesis. We then externally apply these mechanical stress patterns to cell monolayers and demonstrate that equibiaxial compressive stresses (but not uniaxial or equibiaxial tensile stresses) enhance expression of the syndecan-1 and loss of E-cadherin as markers of fusion. These findings suggest that the mechanical stresses that contribute towards sculpting the placental villi may also impact fusion in the developing tissue. We then extend this concept towards 3D cultures and demonstrate that fusion can be enhanced by applying low isometric compressive stresses to spheroid models, even in the absence of an inducing agent. These results indicate that mechanical stimulation is a potent activator of cellular fusion, suggesting novel avenues to improve experimental reproductive modelling, placental tissue engineering, and understanding disorders of pregnancy development.

Precision dosing of venlafaxine during pregnancy: a pharmacokinetics modelling approach

OBJECTIVES

Venlafaxine exposure through gestation is affected by the longitudinal changes in maternal physiology. Confounding treatment is also the impact of CYP2D6 polymorphisms affecting plasma concentrations of venlafaxine.

METHODS

A pharmacokinetic modelling approach was employed to assess variations in maternal and foetal cord venlafaxine levels throughout gestation and to identify appropriate doses to maintain venlafaxine levels within the therapeutic range.

KEY FINDINGS

Throughout gestation, there was a significant decrease in simulated venlafaxine trough plasma concentrations in both extensive metaboliser (EM) and ultra-rapid metaboliser (UM) phenotypes. Approximately 70%-87% of EM and UM phenotypes exhibited trough venlafaxine plasma concentrations below the therapeutic level (<25 ng/ml), which increased to 96% at week 30. While for poor metabolizer (PM) phenotypes, the percentage was approximately 4%.

CONCLUSION

The standard daily dose of 75 mg required adjustment for all phenotypes examined during gestation. A daily dose of 37.5-112.5 mg is appropriate for PM throughout pregnancy. For EM, a dose of 225 mg daily in the first trimester, 262.5 mg daily in the second trimester, and 375 mg daily in the third trimester is suggested to be optimal. For UM, a dose of 375 mg daily throughout gestation is suggested to be optimal.

Mitochondrial-targeted antioxidant attenuates preeclampsia-like phenotypes induced by syncytiotrophoblast-specific Gαq signaling

Syncytiotrophoblast stress is theorized to drive development of preeclampsia, but its molecular causes and consequences remain largely undefined. Multiple hormones implicated in preeclampsia signal via the Gαq cascade, leading to the hypothesis that excess Gαq signaling within the syncytiotrophoblast may contribute. First, we present data supporting increased Gαq signaling and antioxidant responses within villous and syncytiotrophoblast samples of human preeclamptic placenta. Second, Gαq was activated in mouse placenta using Cre-lox and DREADD methodologies. Syncytiotrophoblast-restricted Gαq activation caused hypertension, kidney damage, proteinuria, elevated circulating proinflammatory factors, decreased placental vascularization, diminished spiral artery diameter, and augmented responses to mitochondrial-derived superoxide. Administration of the mitochondrial-targeted antioxidant Mitoquinone attenuated maternal proteinuria, lowered circulating inflammatory and anti-angiogenic mediators, and maintained placental vascularization. These data demonstrate a causal relationship between syncytiotrophoblast stress and the development of preeclampsia and identify elevated Gαq signaling and mitochondrial reactive oxygen species as a cause of this stress.

Preterm Birth and Its Association with Maternal Diet, and Placental and Neonatal Telomere Length

Preterm birth (PTB), a multi-causal syndrome, is one of the global epidemics. Maternal nutrition, but also neonatal and placental telomere length (TL), are among the factors affecting PTB risk. However, the exact relationship between these factors and the PTB outcome, remains obscure. The aim of this review was to investigate the association between PTB, maternal nutrition, and placental-infant TL. Observational studies were sought with the keywords: maternal nutrition, placental TL, newborn, TL, and PTB. No studies were found that included all of the keywords simultaneously, and thus, the keywords were searched in dyads, to reach assumptive conclusions. The findings show that maternal nutrition affects PTB risk, through its influence on maternal TL. On the other hand, maternal TL independently affects PTB risk, and at the same time PTB is a major determinant of offspring TL regulation. The strength of the associations, and the extent of the influence from covariates, remains to be elucidated in future research. Furthermore, the question of whether maternal TL is simply a biomarker of maternal nutritional status and PTB risk, or a causative factor of PTB, to date, remains to be answered.

Gestational ozone inhalation elicits maternal cardiac dysfunction and transcriptional changes to placental pericytes and endothelial cells

Ozone (O3) is a criteria air pollutant with the most frequent incidence of exceeding air quality standards. Inhalation of O3 is known to cause lung inflammation and consequent systemic health effects, including endothelial dysfunction. Epidemiologic data have shown that gestational exposure to air pollutants correlates with complications of pregnancy, including low birth weight, intrauterine growth deficiency, preeclampsia, and premature birth. Mechanisms underlying how air pollution may facilitate or exacerbate gestational complications remain poorly defined. The current study sought to uncover how gestational O3 exposure impacted maternal cardiovascular function, as well as the development of the placenta. Pregnant mice were exposed to 1PPM O3 or a sham filtered air (FA) exposure for 4 h on gestational day (GD) 10.5, and evaluated for cardiac function via echocardiography on GD18.5. Echocardiography revealed a significant reduction in maternal stroke volume and ejection fraction in maternally exposed dams. To examine the impact of maternal O3 exposure on the maternal-fetal interface, placentae were analyzed by single-cell RNA sequencing analysis. Mid-gestational O3 exposure led to significant differential expression of 4021 transcripts compared with controls, and pericytes displayed the greatest transcriptional modulation. Pathway analysis identified extracellular matrix organization to be significantly altered after the exposure, with the greatest modifications in trophoblasts, pericytes, and endothelial cells. This study provides insights into potential molecular processes during pregnancy that may be altered due to the inhalation of environmental toxicants.

Exploring maternal-fetal interface with in vitro placental and trophoblastic models

The placenta, being a temporary organ, plays a crucial role in facilitating the exchange of nutrients and gases between the mother and the fetus during pregnancy. Any abnormalities in the development of this vital organ not only lead to various pregnancy-related disorders that can result in fetal injury or death, but also have long-term effects on maternal health. In vitro models have been employed to study the physiological features and molecular regulatory mechanisms of placental development, aiming to gain a detailed understanding of the pathogenesis of pregnancy-related diseases. Among these models, trophoblast stem cell culture and organoids show great promise. In this review, we provide a comprehensive overview of the current mature trophoblast stem cell models and emerging organoid models, while also discussing other models in a systematic manner. We believe that this knowledge will be valuable in guiding further exploration of the complex maternal-fetal interface.

A Critical Review on the Opportunity to Use Placenta and Innovative Biomonitoring Methods to Characterize the Prenatal Chemical Exposome

Adverse effects associated with chemical exposures during pregnancy include several developmental and reproductive disorders. However, considering the tens of thousands of chemicals present on the market, the effects of chemical mixtures on the developing fetus is still likely underestimated. In this critical review, we discuss the potential to apply innovative biomonitoring methods using high-resolution mass spectrometry (HRMS) on placenta to improve the monitoring of chemical exposure during pregnancy. The physiology of the placenta and its relevance as a matrix for monitoring chemical exposures and their effects on fetal health is first outlined. We then identify several key parameters that require further investigations before placenta can be used for large-scale monitoring in a robust manner. Most critical is the need for standardization of placental sampling. Placenta is a highly heterogeneous organ, and knowledge of the intraplacenta variability of chemical composition is required to ensure unbiased and robust interindividual comparisons. Other important variables include the time of collection, the sex of the fetus, and mode of delivery. Finally, we discuss the first applications of HRMS methods on the placenta to decipher the chemical exposome and describe how the use of placenta can complement biofluids collected on the mother or the fetus.

The Application of Engineered Nanomaterials in Perinatal Therapeutics

Pregnancy is a vulnerable life stage for the mother and developing fetus. Because of this dual concern, approved therapeutic options for pre-existing conditions or pregnancy-induced pathologies, placental deformities, or fetal concerns are extremely limited. These cases often leave patients and clinicians having to choose between maternal health and fetal development. Recent advancements in nanomedicine and nanotherapeutic devices have made the development of perinatal therapeutics an attractive objective. However, perinatal medicine requires a multifaceted approach given the interactions between maternal, placental, and fetal physiology. Maternal-fetal interactions are centralized to the placenta, a specialized transient barrier organ, to allow for nutrient and waste exchange. Perinatal nanotherapeutics must be designed for placental avoidance or uptake. In this review, pregnancy-related conditions, experimental models, and modes of drug delivery during pregnancy are discussed.

Effect of Extra-abdominal Vein Varix on the Stress Distribution in Umbilical Cord: A Simulation Study

The umbilical cord is a critical structure linking the fetus to the placenta and is surrounded by the amniotic fluid. It is composed of a vein, two arteries coiled around the vein, and Wharton's jelly surrounding the blood vessels. In this study, the stress distribution of the arteries, vein, and Wharton's jelly of an umbilical cord with extra-abdominal umbilical vein varix is analyzed for varying amniotic pressure using finite element analysis. Four diameters are considered for the umbilical vein, 6.5 mm, 11 mm, 15.5 mm, and 20 mm, with 6.5 mm corresponding to the normal vein diameter. The amniotic pressure is varied from 15-105 mmHg in steps of 15 mmHg, to simulate contractions during labour. Stress distribution is obtained and the peak stresses are analyzed. According to the results, the peak stress in the Wharton's jelly and the umbilical vein increases nonlinearly with increasing amniotic pressure. The peak stress in umbilical arteries initially decreases till the amniotic pressure reaches 45 mmHg and thereafter increases. This might be due to asymmetric deformation of the Wharton's jelly at the pressure range below arterial pressure.Clinical Relevance- This study could be useful in understanding the fundamental mechanics of extra-abdominal umbilical vein varix and help in development of better treatment protocols.

Unveiling Distribution of Per- and Polyfluoroalkyl Substances in Matched Placenta-Serum Tetrads: Novel Implications for Birth Outcome Mediated by Placental Vascular Disruption

The placenta is pivotal for fetal development and maternal-fetal transfer of many substances, including per- and polyfluoroalkyl substances (PFASs). However, the intraplacental distribution of PFASs and their effects on placental vascular function remain unclear. In this study, 302 tetrads of matched subchorionic placenta (fetal-side), parabasal placenta (maternal-side), cord serum, and maternal serum samples were collected from Guangzhou, China. Eighteen emerging and legacy PFASs and five placental vascular biomarkers were measured. Results showed that higher levels of perfluorooctanoic (PFOA), perfluorooctane sulfonic acid (PFOS), and chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs) were detected in subchorionic placenta compared to parabasal placenta. There were significant associations of PFASs in the subchorionic placenta, but not in the serum, with placental vascular biomarkers (up to 32.5%) and lower birth size. Birth weight was negatively associated with PFOA (β: -103.8, 95% CI: -186.3 and -21.32) and 6:2 Cl-PFESA (β: -80.04, 95% CI: -139.5 and -20.61), primarily in subchorionic placenta. Mediation effects of altered placental angiopoietin-2 and vascular endothelial growth factor receptor-2 were evidenced on associations of adverse birth outcomes with intraplacental PFOS and 8:2 Cl-PFESA, explaining 9.5%-32.5% of the total effect. To the best of our knowledge, this study is the first to report on differential intraplacental distribution of PFASs and placental vascular effects mediating adverse birth outcomes and provides novel insights into the placental plate-specific measurement in PFAS-associated health risk assessment.

Development and evaluation of a wearable peripheral vascular compensation sensor in a swine model of hemorrhage

Postpartum hemorrhage (PPH) is both the leading and most preventable cause of maternal mortality. PPH is currently diagnosed through visual estimation of blood loss or vital sign analysis of shock index (ratio of heart rate to systolic blood pressure). Visual assessment underestimates blood loss, particularly in the setting of internal bleeding, and compensatory mechanisms stabilize hemodynamics until hemorrhage is massive, beyond the point of pharmaceutical intervention. Quantitative monitoring of hemorrhage-induced compensatory processes, such as the constriction of peripheral vessels to shunt blood to the central organs, may provide an early alert for PPH. To this end, we developed a low-cost, wearable optical device that continuously monitors peripheral perfusion via laser speckle flow index (LSFI) to detect hemorrhage-induced peripheral vasoconstriction. The device was first tested using flow phantoms across a range of physiologically relevant flow rates and demonstrated a linear response. Subsequent testing occurred in swine hemorrhage studies (n=6) by placing the device on the posterior side of the swine's front hock and withdrawing blood from the femoral vein at a constant rate. Resuscitation with intravenous crystalloids followed the induced hemorrhage. The mean LSFI vs. percent estimated blood volume loss had an average correlation coefficient of -0.95 during the hemorrhage phase and 0.79 during resuscitation, both of which were superior to the performance of the shock index. With continued development, this noninvasive, low-cost, and reusable device has global potential to provide an early alert of PPH when low-cost and accessible management strategies are most effective, helping to reduce maternal morbidity and mortality from this largely preventable problem.

Obstetric Outcomes in Singleton Pregnancies with Abnormal Placental Cord Insertions

OBJECTIVE

There is wide variation in the management of pregnancies complicated by abnormal placental cord insertion (PCI), which includes velamentous cord insertion (VCI) and marginal cord insertion (MCI). We tested the hypothesis that abnormal PCI is associated with small for gestational age (SGA) infants.

STUDY DESIGN

This is a retrospective cohort study of all pregnant patients undergoing anatomic ultrasound at a single institution from 2010 to 2017. Patients with abnormal PCI were matched in a 1:2 ratio by race, parity, gestational age at the time of ultrasound, and obesity to patients with normal PCIs. The primary outcome was SGA at delivery. Secondary outcomes were cesarean delivery, preterm delivery, cesarean delivery for nonreassuring fetal status, 5-minute Apgar score < 7, umbilical artery pH < 7.1, and neonatal intensive care unit admission. These outcomes were compared using univariate and bivariate analyses.

RESULTS

Abnormal PCI was associated with an increased risk of SGA (relative risk [RR]: 2.43; 95% confidence interval [CI]: 1.26-4.69), increased risk of preterm delivery <37 weeks (RR: 3.60; 95% CI: 1.74-7.46), and <34 weeks (RR: 3.50; 95% CI: 1.05-11.63) compared with patients with normal PCI. There was no difference in rates of cesarean delivery, Apgar score of <7 at 5 minutes, acidemia, or neonatal intensive care unit admission between normal and abnormal PCI groups. In a stratified analysis, the association between abnormal PCI and SGA did not differ by the type of abnormal PCI (p for interaction = 0.46).

CONCLUSION

Abnormal PCI is associated with an increased risk of SGA and preterm delivery. These results suggest that serial fetal growth assessments in this population may be warranted.

KEY POINTS

· Abnormal PCI is associated with SGA infants and preterm birth.. · If an abnormal PCI is identified, the provider should consider serial growth ultrasounds.. · There is no difference in obstetric outcomes between VCI and MCI..

The O-GlcNAc cycling in neurodevelopment and associated diseases

Proper neuronal development is essential to growth and adult brain function. Alterations at any step of this highly organized sequence of events, due to genetic mutations or environmental factors, triggers brain malformations, which are leading causes of diseases including epilepsy, intellectual disabilities, and many others. The role of glycosylation in neuronal development has been emphasized for many years, notably in studying human congenital disorders of glycosylation (CDGs). These diseases highlight that genetic defects in glycosylation pathways are almost always associated with severe neurological abnormalities, suggesting that glycosylation plays an essential role in early brain development. Congenital disorders of O-GlcNAcylation are no exception, and all mutations of the O-GlcNAc transferase (OGT) are associated with X-linked intellectual disabilities (XLID). In addition, mouse models and in vitro mechanistic studies have reinforced the essential role of O-GlcNAcylation in neuronal development and signaling. In this review, we give an overview of the role of O-GlcNAcylation in this critical physiological process and emphasize the consequences of its dysregulation.

Infectious Complications of Abortion

This article reviews the infectious complications of abortion (both spontaneous and induced) and the management of this condition. The key points are: (1) Making abortion illegal does not reduce its incidence or prevalence; rather, it only makes abortions unsafe, increasing the likelihood of infectious complications. (2) Timely recognition of developing sepsis in the pregnant patient is critical. This requires constant vigilance and a high index of suspicion. (3) Rapid intravenous administration of broad-spectrum antibiotics targeted to the likely intrauterine source of infection as soon as sepsis is diagnosed is critical to prevent severe sepsis, septic shock, and multisystem organ failure. (4) The mainstay of treatment is prompt evacuation of any residual products of conception from within the uterine cavity under broad-spectrum antibiotic cover targeting the likely intrauterine source of infection. (5) Prompt engagement of specialists in both critical care and obstetrics-gynecology is necessary to optimize outcomes in patients with septic abortion.

Allometric scaling relationships in mouse placenta

Fetal growth and maturation are highly intertwined with placental development during pregnancy. Here we used placental vascular morphology measurements (depth and span) as well as the umbilical artery (UA) diameter of previously published studies on three different mouse strains (C57BL6/J, CD-1 and BALB/c), which were exposed to different conditions (combination antiretroviral therapy, chronic maternal hypoxia and malaria infection) at different embryonic days, to test the hypothesis that placental vascularization and specifically the UA size affect conceptus weight. Interaction of each study parameter with embryonic day, strain and exposure to treatments are studied to investigate the stability of the scaling relationships across and/or within strains and conditions. In addition, the effect of UA diameter on the placental growth measurements (depth and span) is studied. These results show that the power-law scaling relationship of conceptus weight and placental depth with the UA diameter is conserved across strains and conditions with the scaling exponent of approximately 3/8 and 5/8, respectively. By contrast, the relationship between conceptus weight and either the placental span or depth is different between strains and conditions, suggesting multiple mechanisms of vascular adaptation.

Systemic lupus erythematosus dysregulates the expression of long noncoding RNAs in placentas

Background

Systemic lupus erythematosus (SLE) can cause placental dysfunctions, which may result in pregnancy complications. Long noncoding RNAs (lncRNAs) are actively involved in the regulation of immune responses during pregnancy. The present study aimed to determine the lncRNA expression profiles in placentas from women with SLE to gain new insights into the underlying molecular mechanisms in SLE pregnancies.

Methods

RNA sequencing (RNA-seq) analysis was performed to identify SLE-dysregulated lncRNAs and mRNAs in placentas from women with SLE and normal full-term (NT) pregnancies. Bioinformatics analysis was conducted to predict the biological functions of these SLE-dysregulated lncRNAs and mRNAs.

Results

RNA-seq analysis identified 52 dysregulated lncRNAs in SLE placentas, including 37 that were upregulated and 15 downregulated. Additional 130 SLE-dysregulated mRNAs were discovered, including 122 upregulated and 8 downregulated. Bioinformatics analysis revealed that SLE-dysregulated genes were associated with biological functions and gene networks, such as regulation of type I interferon-mediated signaling pathway, response to hypoxia, regulation of MAPK (mitogen-activated protein kinase) cascade, response to steroid hormone, complement and coagulation cascades, and Th1 and Th2 cell differentiation.

Conclusions

This is the first report of the lncRNA profiles in placentas from SLE pregnancies. These results suggest that the aberrant expression and the potential regulatory function of lncRNAs in placentas may play comprehensive roles in the pathogenesis of SLE pregnancies. SLE-dysregulated lncRNAs may potentially serve as biomarkers for SLE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02825-7.

Large-scale placenta DNA methylation integrated analysis reveals fetal sex-specific differentially methylated CpG sites and regions

Although male–female differences in placental structure and function have been observed, little is understood about their molecular underpinnings. Here, we present a mega-analysis of 14 publicly available placenta DNA methylation (DNAm) microarray datasets to identify individual CpGs and regions associated with fetal sex. In the discovery dataset of placentas from full term pregnancies (N = 532 samples), 5212 CpGs met genome-wide significance (p < 1E−8) and were enriched in pathways such as keratinization (FDR p-value = 7.37E−14), chemokine activity (FDR p-value = 1.56E−2), and eosinophil migration (FDR p-value = 1.83E−2). Nine differentially methylated regions were identified (fwerArea < 0.1) including a region in the promoter of ZNF300 that showed consistent differential DNAm in samples from earlier timepoints in pregnancy and appeared to be driven predominately by effects in the trophoblast cell type. We describe the largest study of fetal sex differences in placenta DNAm performed to date, revealing genes and pathways characterizing sex-specific placenta function and health outcomes later in life.

A review of the amino acid metabolism in placental function response to fetal loss and low birth weight in pigs

The fertility of sows mainly depends on the embryo losses during gestation and the survival rate of the post-farrowing piglets. The selection of highly-prolific sows has been mainly focused on the selection of genotypes with high ovulatory quota. However, in the early- and post-implantation stages, the rate of embryo losses was increased with the increase of zygotes. Among the various factors, placental growth and development is the vital determinant for fetal survival, growth, and development. Despite the potential survival of fetuses with deficient placental development, their life-conditions and growth can be damaged by a process termed intrauterine growth retardation (IUGR). The newborn piglets affected by IUGR are prone to increased morbidity and mortality rates; meanwhile, the growth, health and welfare of the surviving piglets will remain hampered by these conditions, with a tendency to exacerbate with age. Functional amino acids such as glycine, proline, and arginine continue to increase with the development of placenta, which are not only essential to placental growth (including vascular growth) and development, but can also be used as substrates for the production of glutathione, polyamines and nitric oxide to benefit placental function in many ways. However, the exact regulation mechanism of these amino acids in placental function has not yet been clarified. In this review, we provide evidence from literature and our own work for the role and mechanism of dietary functional amino acids during pregnancy in regulating the placental functional response to fetal loss and birth weight of piglets. This review will provide novel insights into the response of nutritionally nonessential amino acids (glycine and proline) to placental development as well as feasible strategies to enhance the fertility of sows.

Placental Trophoblast Specific Overexpression of Chemerin Induces Preeclampsia-like Symptoms

Maternal circulating levels of the adipokine chemerin are elevated in preeclampsia, but its origin and contribution to preeclampsia remain unknown. We therefore studied 1) placental chemerin expression and release in human pregnancy, and 2) the consequences of chemerin overexpression via lentivirus-mediated trophoblast-specific gene manipulation in both mice and immortalized human trophoblast. Placental chemerin expression and release were increased in women with preeclampsia, and their circulating chemerin levels correlated positively with the soluble Fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor ratio, a well-known biomarker of preeclampsia severity. Placental trophoblast chemerin overexpression in mice induced a preeclampsia-like syndrome, involving hypertension, proteinuria, and endotheliosis, combined with diminished trophoblast invasion, a disorganized labyrinth layer, and upregulation of sFlt-1 and the inflammation markers nuclear factor-kappa B, tumor necrosis factor-α and interleukin-1β. It also led to embryo resorption, while maternal serum chemerin levels correlated negatively with fetal weight in mice. Chemerin overexpression in human trophoblasts upregulated sFlt-1, reduced vascular endothelial factor-A, and inhibited migration and invasion, as well as tube formation during co-culture with human umbilical vein endothelial cells. The chemokine-like receptor 1 (CMKLR1) antagonist α-NETA prevented the latter phenomena, although it did not reverse the chemerin-induced downregulation of the phosphoinositide 3-kinase/Akt pathway. In conclusion, upregulation of placental chemerin synthesis disturbs normal placental development via its CMKLR1 receptor, thereby contributing to fetal growth restriction/resorption and the development of preeclampsia. Chemerin might be a novel biomarker of preeclampsia, and inhibition of the chemerin/CMKLR1 pathway is a promising novel therapeutic strategy to treat preeclampsia.

Preeclamptic Women Have Disrupted Placental microRNA Expression at the Time of Preeclampsia Diagnosis: Meta-Analysis

Introduction: Preeclampsia (PE) is a pregnancy-associated, multi-organ, life-threatening disease that appears after the 20th week of gestation. The aim of this study was to perform a systematic review and meta-analysis to determine whether women with PE have disrupted miRNA expression compared to women who do not have PE. Methods: We conducted a systematic review and meta-analysis of studies that reported miRNAs expression levels in placenta or peripheral blood of pregnant women with vs. without PE. Studies published before October 29, 2021 were identified through PubMed, EMBASE and Web of Science. Two reviewers used predefined forms and protocols to evaluate independently the eligibility of studies based on titles and abstracts and to perform full-text screening, data abstraction and quality assessment. Standardized mean difference (SMD) was used as a measure of effect size. Results: 229 publications were included in the systematic review and 53 in the meta-analysis. The expression levels in placenta were significantly higher in women with PE compared to women without PE for miRNA-16 (SMD = 1.51,95%CI = 0.55-2.46), miRNA-20b (SMD = 0.89, 95%CI = 0.33-1.45), miRNA-23a (SMD = 2.02, 95%CI = 1.25-2.78), miRNA-29b (SMD = 1.37, 95%CI = 0.36-2.37), miRNA-155 (SMD = 2.99, 95%CI = 0.83-5.14) and miRNA-210 (SMD = 1.63, 95%CI = 0.69-2.58), and significantly lower for miRNA-376c (SMD = -4.86, 95%CI = -9.51 to -0.20). An increased level of miRNK-155 expression was found in peripheral blood of women with PE (SMD = 2.06, 95%CI = 0.35-3.76), while the expression level of miRNA-16 was significantly lower in peripheral blood of PE women (SMD = -0.47, 95%CI = -0.91 to -0.03). The functional roles of the presented miRNAs include control of trophoblast proliferation, migration, invasion, apoptosis, differentiation, cellular metabolism and angiogenesis. Conclusion: miRNAs play an important role in the pathophysiology of PE. The identification of differentially expressed miRNAs in maternal blood creates an opportunity to define an easily accessible biomarker of PE.

Frequently used strategies to isolate ECM proteins from human placenta and adipose tissue

BACKGROUND

The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the last years. However, every single isolation strategy reported so far is associated with specific bottlenecks. Experiment: In this study, frequently used strategies to isolate extracellular matrix (ECM) from human placenta or adipose tissue using Tris-, serum, or pepsin-based buffers were compared. The resulting ECM proteins were biochemically characterized by analysis of cellular remnants using HOECHST DNA staining, glycosaminoglycan (GAG) content by dimethylemethylene blue (DMMB), visualization of protein bands using SDS PAGE analysis combined with amino acid quantification and assessment of the pro-angiogenic profile using an angiogenesis array.

RESULTS

Tris-NaCl extracted ECM proteins showed a high heterogenic degree of extracted proteins, bioactive growth factors and GAGS, but no collagen-I. Active serum extracted ECM showed significant lower DNA remnants when compared to the Tris-NaCl isolation strategy. Pepsin-extracted ECM was rich in collagen-I and low amounts of remaining bioactive growth factors. This strategy was most effective to reduce DNA amounts when compared to the other isolation strategies. Pepsin-extracted ECM from both tissues easily gelled at 37°C, whereas the other extracted ECM strategies did not gel at 37°C (Tris-NaCl: liquid; serum: sponge).

CONCLUSIONS

All relevant characteristics (DNA residues, ECM diversity and bioactivity, shape) of the extracted ECM proteins highly depend on its isolation strategy and could still be optimized.

Novel Human Placenta-Based Extract for Vascularization Strategies in Tissue Engineering

There is critical unmet need for new vascularized tissues to support or replace injured tissues and organs. Various synthetic and natural materials were already established for use of two-dimensional (2D) and three-dimensional (3D) in vitro neovascularization assays, however, they still cannot mimic the complex functions of the sum of the extracellular matrix (ECM) in native intact tissue. Currently, this issue is only addressed by artificial products such as Matrigel^™, which comprises a complex mixture of ECM proteins, extracted from animal tumor tissue. Despite its outstanding bioactivity, the isolation from tumor tissue hinders its translation into clinical applications. Since nonhuman ECM proteins may cause immune reactions, as are frequently observed in clinical trials, human ECM proteins represent the best option when aiming for clinical applications. Here, we describe an effective method of isolating a human placenta substrate (hpS) that induces the spontaneous formation of an interconnected network of green fluorescence-labeled human umbilical vein endothelial cells (gfpHUVECs) in vitro. The substrate was biochemically characterized by using a combination of bicinchoninic acid (BCA) assay, DNA, and glycosaminoglycan (GAG) content assays, sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) analysis and Western blot, angiogenesis arrays, chromatographic thrombin detection, high performance liquid chromatography (HPLC)-based amino acid quantification analysis, and assessment of antimicrobial properties. 2D in vitro cell culture experiments have been performed to determine the vasculogenic potential of hpS, which demonstrated that cell networks developed on hpS show a significantly higher degree of complexity (number of tubules/junctions; total/mean tube length) when compared with Matrigel. As 3D cell culture techniques represent a more accurate representation of the in vivo condition, the substrate was 3D solidified using various natural polymers. 3D in vitro vasculogenesis assays have been performed by seeding gfpHUVECs in an hpS-fibrinogen clot. In conclusion, hpS provides a potent human/material-based alternative to xenogenic-material-based biomaterials for vascularization strategies in tissue engineering.

Proteome profiling of human placenta reveals developmental stage-dependent alterations in protein signature

Introduction

Placenta is a complex organ that plays a significant role in the maintenance of pregnancy health. It is a dynamic organ that undergoes dramatic changes in growth and development at different stages of gestation. In the first-trimester, the conceptus develops in a low oxygen environment that favors organogenesis in the embryo and cell proliferation and angiogenesis in the placenta; later in pregnancy, higher oxygen concentration is required to support the rapid growth of the fetus. This oxygen transition, which appears unique to the human placenta, must be finely tuned through successive rounds of protein signature alterations. This study compares placental proteome in normal first-trimester (FT) and term human placentas (TP).

Methods

Normal human first-trimester and term placental samples were collected and differentially expressed proteins were identified using two-dimensional liquid chromatography-tandem mass spectrometry.

Results

Despite the overall similarities, 120 proteins were differently expressed in first and term placentas. Out of these, 72 were up-regulated and 48 were down-regulated in the first when compared with the full term placentas. Twenty out of 120 differently expressed proteins were sequenced, among them seven showed increased (GRP78, PDIA3, ENOA, ECH1, PRDX4, ERP29, ECHM), eleven decreased (TRFE, ALBU, K2C1, ACTG, CSH2, PRDX2, FABP5, HBG1, FABP4, K2C8, K1C9) expression in first-trimester compared to the full-term placentas and two proteins exclusively expressed in first-trimester placentas (MESD, MYDGF).

Conclusion

According to Reactome and PANTHER softwares, these proteins were mostly involved in response to chemical stimulus and stress, regulation of biological quality, programmed cell death, hemostatic and catabolic processes, protein folding, cellular oxidant detoxification, coagulation and retina homeostasis. Elucidation of alteration in protein signature during placental development would provide researchers with a better understanding of the critical biological processes of placentogenesis and delineate proteins involved in regulation of placental function during development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12014-021-09324-y.

Placental Villous Explant Culture 2.0: Flow Culture Allows Studies Closer to the In Vivo Situation

During pregnancy, freely floating placental villi are adapted to fluid shear stress due to placental perfusion with maternal plasma and blood. In vitro culture of placental villous explants is widely performed under static conditions, hoping the conditions may represent the in utero environment. However, static placental villous explant culture dramatically differs from the in vivo situation. Thus, we established a flow culture system for placental villous explants and compared commonly used static cultured tissue to flow cultured tissue using transmission and scanning electron microscopy, immunohistochemistry, and lactate dehydrogenase (LDH) and human chorionic gonadotropin (hCG) measurements. The data revealed a better structural and biochemical integrity of flow cultured tissue compared to static cultured tissue. Thus, this new flow system can be used to simulate the blood flow from the mother to the placenta and back in the most native-like in vitro system so far and thus can enable novel study designs.

Effects of Maternal Obesity and Gestational Diabetes Mellitus on the Placenta: Current Knowledge and Targets for Therapeutic Interventions

Obesity and gestational diabetes mellitus (GDM) are becoming more common among pregnant women worldwide and are individually associated with a number of placenta-mediated obstetric complications, including preeclampsia, macrosomia, intrauterine growth restriction and stillbirth. The placenta serves several functions throughout pregnancy and is the main exchange site for the transfer of nutrients and gas from mother to fetus. In pregnancies complicated by maternal obesity or GDM, the placenta is exposed to environmental changes, such as increased inflammation and oxidative stress, dyslipidemia, and altered hormone levels. These changes can affect placental development and function and lead to abnormal fetal growth and development as well as metabolic and cardiovascular abnormalities in the offspring. This review aims to summarize current knowledge on the effects of obesity and GDM on placental development and function. Understanding these processes is key in developing therapeutic interventions with the goal of mitigating these effects and preventing future cardiovascular and metabolic pathology in subsequent generations.

Uterine Vascular Control Preconception and During Pregnancy

Successful pregnancy and reproduction are dependent on adequate uterine blood flow, placental perfusion, and vascular responsivity to fetal demands. The ability to support pregnancy centers on systemic adaptation and endometrial preparation through decidualization, embryonic implantation, trophoblast invasion, arterial/arteriolar reactivity, and vascular remodeling. These adaptations occur through responsiveness to endocrine signaling and local uteroplacental mediators. The purpose of this article is to highlight the current knowledge associated with vascular remodeling and responsivity during uterine preparation for and during pregnancy. We focus on maternal cardiovascular systemic and uterine modifications, endometrial decidualization, implantation and invasion, uterine and spiral artery remodeling, local uterine regulatory mechanisms, placentation, and pathological consequences of vascular dysfunction during pregnancy. © 2021 American Physiological Society. Compr Physiol 11:1-23, 2021.

Placental decidual arteriopathy and vascular endothelial growth factor A (VEGF-A) expression among women with and without HIV

BACKGROUND

Women with HIV (WHIV) are at higher risk of adverse birth outcomes. Proposed mechanisms for the increased risk include placental arteriopathy (vasculopathy) and maternal vascular malperfusion (MVM) due to antiretroviral therapy (ART) and medical comorbidities. However, these features and their underlying pathophysiologic mechanisms have not been well characterized in WHIV.

METHODS

We performed gross and histologic examination and immunohistochemistry staining for vascular endothelial growth factor A (VEGF-A), a key angiogenic factor, on placentas from women with one or more MVM risk factors including: weight <5 th percentile, histologic infarct or distal villous hypoplasia, nevirapine-based ART, hypertension, and pre-eclampsia/eclampsia during pregnancy. We compared pathologic characteristics by maternal HIV serostatus.

RESULTS

A total of 27/41 (66%) placentas assessed for VEGF-A were from WHIV. Mean maternal age was 27 years. Among WHIV, median CD4 T-cell count was 440 cells/mm 3 and HIV viral load was undetectable in 74%. Of VEGF-A stained placentas, both decidua and villous endothelium tissue layers were present in 36 (88%). VEGF-A was detected in 31/36 (86%) with decidua present, and 39/40 (98%) with villous endothelium present. There were no differences in VEGF-A presence in any tissue type by maternal HIV serostatus (P=0.28-1.0). MVM was more common in placentas selected for VEGF-A staining (51 versus 8%, P<0.001).

CONCLUSIONS

VEGF-A immunostaining was highly prevalent, and staining pattern did not differ by maternal HIV serostatus among those with MVM risk factors, indicating the role of VEGF-A in placental vasculopathy may not differ by maternal HIV serostatus.

Physical activity differentially regulates VEGF, PlGF, and their receptors in the human placenta

Physical activity (PA) has beneficial effects on the function of many organs by modulating their vascular development. Regular PA during pregnancy is associated with favorable short‐ and long‐term outcomes for both mother and fetus. During pregnancy, appropriate vascularization of the placenta is crucial for adequate maternal–fetal nutrient and gas exchange. How PA modulates angiogenic factors, VEGF, and its receptors in the human placenta, is as of yet, unknown. We objectively measured the PA of women at 24–28 and 34–38 weeks of gestation. Participants were considered “active” if they had met or exceeded 150 min of moderate‐intensity PA per week during their 2nd trimester. Term placenta tissues were collected from active (n = 23) or inactive (n = 22) women immediately after delivery. We examined the expression of the angiogenic factors VEGF, PlGF, VEGFR‐1, and VEGFR‐2 in the placenta. Western blot analysis showed VEGF and its receptor, VEGFR‐1 was significantly (p < 0.05) higher both at the protein and mRNA levels in placenta from physically active compared to inactive women. No difference in VEGFR‐2 was observed. Furthermore, immunohistochemistry showed differential staining patterns of VEGF and its receptors in placental endothelial, stromal, and trophoblast cells and in the syncytial brush border. In comparison, PlGF expression did not differ either at the protein or mRNA level in the placenta from physically active or inactive women. The expression and localization pattern of VEGF and its receptors suggest that PA during pregnancy may support a pro‐angiogenic milieu to the placental vascular network.

COVID-19 in 28-Week Triplets Caused by Intrauterine Transmission of SARS-CoV-2-Case Report

Since the beginning of the COVID-19 pandemic, in-utero transmission of SARS-CoV-2 remains a rarity and only very few cases have been proven across the world. Here we depict the clinical, laboratory and radiologic findings of preterm triplets born at 28 6/7 weeks to a mother who contracted COVID-19 just 1 week before delivery. The triplets showed SARS-CoV-2 positivity right after birth, developed significant leukopenia and early-onset pulmonary interstitial emphysema. The most severely affected triplet I required 10 days of high-frequency oscillatory ventilation due to failure of conventional invasive ventilation, and circulatory support for 4 days. Despite a severe clinical course in two triplets (triplet I and II), clinical management without experimental, targeted antiviral drugs was successful. At discharge home, the triplets showed no signs of neurologic or pulmonary sequelae. Placental immunohistology with SARS-CoV-2 N-protein localized strongly to syncytiotrophoblast cells and, to a lesser extent, to fetal Hofbauer cells, proving intrauterine virus transmission. We discuss the role of maternal viremia as a potential risk factor for vertical transmission. To the best of our knowledge, our report presents the earliest unequivocally confirmed prenatal virus transmission in long-term surviving children, i.e., at the beginning of the third trimester.

Association between blood lead level during pregnancy and birth weight: A meta-analysis

BACKGROUND

We aimed to provide a quantitative summary of evidence for a relationship between prenatal lead (Pb) exposure and birth weight.

METHODS

PubMed and Web of Science databases were searched for eligible epidemiological studies. We transformed findings in eligible studies with different effect-size metrics to standardized regression coefficients, and used fixed-effects or random-effects models to assess the pooled effects of prenatal Pb exposure on birth weight.

RESULTS

There was a significant negative association between prenatal Pb exposure and birth weight. Birth weight reduction was associated with elevated lead levels in maternal blood (β = -0.094; 95% confidence interval [CI]: -0.157 to -0.030) and cord blood (β = -0.120; 95% CI: -0.239 to -0.001).

CONCLUSIONS

This meta-analysis is the first to provide a quantitative assessment of Pb exposure during pregnancy and an increased risk of lower birth weight.

Human placental cell line HTR-8/SVneo accumulates cadmium by divalent metal transporters DMT1 and ZIP14

Cadmium (Cd) is a global pollutant that accumulates in the placenta and can cause placental dysfunction. Although iron transporters have been suggested to participate in placental Cd uptake, it is still unknown which transporters are actually involved in this process. We specifically aimed to study the role of three iron transporters in the uptake of Cd into the placental cell line HTR-8/SVneo. For this purpose, Divalent Metal Transporter (DMT)1 and ZRT/IRT like protein (ZIP)8 and ZIP14 were downregulated and changes in cellular Cd levels analysed in relation to controls. As clearly shown by the reduction of the Cd content by ∼60% in DMT1- and ZIP14-downregulated cells, the two proteins are essential for Cd accumulation in HTR-8/SVneo cells. Using a validated antibody, we show DMT1 to be localised in situ in trophoblast and stromal cells. We further wanted to investigate how placental cells cope with Cd loading and which metallothionein (MT) isoforms they express. Cd-exposed cells accumulate Cd in a dose-dependent manner and upregulate MT2A accordingly (up to 15-fold induction upon 5 μM CdCl₂ treatment for 72 h). 5 μM Cd exposure for 72 h decreased cell number to 60%, an effect that was aggravated by MT2A depletion (cell number reduced to 30%) indicating additive effects. In conclusion, our data suggest that DMT1 and ZIP14 are required for Cd uptake into human placental cells that upregulate MT2A to store and detoxify the metal. Cd storage in the placenta reduces Cd transport to the fetus, which, however, could impair placental functions and fetal development.

Effect of Maternal Retinol Status at Time of Term Delivery on Retinol Placental Concentration, Intrauterine Transfer Rate, and Newborn Retinol Status

Retinol (vitamin A) is essential, so the objective of this Institutional Review Board approved study is to evaluate retinol placental concentration, intrauterine transfer, and neonatal status at time of term delivery between cases of maternal retinol adequacy, insufficiency, and deficiency in a United States population. Birth information and biological samples were collected for mother–infant dyads (n = 260). Maternal and umbilical cord blood retinol concentrations (n = 260) were analyzed by HPLC and categorized: deficient (≤0.7 umol/L), insufficient (>0.7–1.05 umol/L), adequate (>1.05 umol/L). Intrauterine transfer rate was calculated: (umbilical cord blood retinol concentration/maternal retinol concentration) × 100. Non-parametric statistics used include Spearman’s correlations, Mann–Whitney U, and Kruskal–Wallis tests. p-values <0.05 were statistically significant. Only 51.2% of mothers were retinol adequate, with 38.4% insufficient, 10.4% deficient. Only 1.5% of infants were retinol adequate. Placental concentrations (n = 73) differed between adequate vs. deficient mothers (median 0.13 vs. 0.10 μg/g; p = 0.003). Umbilical cord blood concentrations were similar between deficient, insufficient, and adequate mothers (0.61 vs. 0.55 vs. 0.57 μmol/L; p = 0.35). Intrauterine transfer increased with maternal deficiency (103.4%) and insufficiency (61.2%) compared to adequacy (43.1%), p < 0.0001. Results indicate that intrauterine transfer rate is augmented in cases of maternal retinol inadequacy, leading to similar concentrations in umbilical cord blood at term delivery.

MAIT Cells at the Fetal-Maternal Interface During Pregnancy

One of the main functions of the human placenta is to provide a barrier between the fetal and maternal blood circulations, where gas exchange and transfer of nutrients to the developing fetus take place. Despite being a barrier, there is a multitude of crosstalk between maternal immune cells and fetally derived semi-allogeneic trophoblast cells. Therefore, the maternal immune system has a difficult task to both tolerate the fetus but at the same time also defend the mother and the fetus from infections. Mucosal-associated invariant T (MAIT) cells are an increasingly recognized subset of T cells with anti-microbial functions that get activated in the context of non-polymorphic MR1 molecules, but also in response to inflammation. MAIT cells accumulate at term pregnancy in the maternal blood that flows into the intervillous space inside the placenta. Chemotactic factors produced by the placenta may be involved in recruiting and retaining particular immune cell subsets, including MAIT cells. In this Mini-Review, we describe what is known about MAIT cells during pregnancy and discuss the potential biological functions of MAIT cells at the fetal-maternal interface. Since MAIT cells have anti-microbial and tissue-repairing functions, but lack alloantigen reactivity, they could play an important role in protecting the fetus from bacterial infections and maintaining tissue homeostasis without risks of mediating harmful responses toward semi-allogenic fetal tissues.

Advances in imaging feto-placental vasculature: new tools to elucidate the early life origins of health and disease

Optimal placental function is critical for fetal development, and therefore a crucial consideration for understanding the developmental origins of health and disease (DOHaD). The structure of the fetal side of the placental vasculature is an important determinant of fetal growth and cardiovascular development. There are several imaging modalities for assessing feto-placental structure including stereology, electron microscopy, confocal microscopy, micro-computed tomography, light-sheet microscopy, ultrasonography and magnetic resonance imaging. In this review, we present current methodologies for imaging feto-placental vasculature morphology ex vivo and in vivo in human and experimental models, their advantages and limitations and how these provide insight into placental function and fetal outcomes. These imaging approaches add important perspective to our understanding of placental biology and have potential to be new tools to elucidate a deeper understanding of DOHaD.

Oxidative status of maternal blood in pregnancies burdened by inherited thrombophilias

Oxidative status of maternal blood represents an important parameter of pregnancy that is involved in both, regulation of physiological processes and (if significantly altered) development of different pregnancy complications. Inherited thrombophilias represent genetic disorders that increase the risk of thromboembolism in pregnancy. Little is known about the impact of thrombophilia on the oxidative status of maternal blood. In this study, we analyzed oxidative status of blood of 56 women with pregnancies burdened by inherited thrombophilias. The status was established at three different trimesters using biochemical assays and electrochemical measurements, and it was compared to 10 age- and trimester-matching controls. Activities of superoxide dismutase, catalase, and glutathione reductase in the 1st and the 2nd trimester of thrombophilic pregnancy were lower than controls. Also, there was less oxidation in the plasma, according to higher concentration of reduced thiols and lower oxidation-reduction potential. Therefore, it appears that thrombophilic mothers do not experience oxidative stress in the circulation in the first two trimesters. However, the rise in GPx, GR and SOD activities in the 3rd trimester of thrombophilic pregnancy implies that the risk of oxidative stress is increased during the late pregnancy. These results are important for developing antioxidative treatment that could tackle thrombophilia-related pregnancy complications.

Relevance of the Materno-Fetal Interface for the Induction of Antigen-Specific Immune Tolerance

In humans, maternal IgGs are transferred to the fetus from the second trimester of pregnancy onwards. The transplacental delivery of maternal IgG is mediated by its binding to the neonatal Fc receptor (FcRn) after endocytosis by the syncytiotrophoblast. IgGs present in the maternal milk are also transferred to the newborn through the digestive epithelium upon binding to the FcRn. Importantly, the binding of IgGs to the FcRn is also responsible for the recycling of circulating IgGs that confers them with a long half-life. Maternally delivered IgG provides passive immunity to the newborn, for instance by conferring protective anti-flu or anti-pertussis toxin IgGs. It may, however, lead to the development of autoimmune manifestations when pathological autoantibodies from the mother cross the placenta and reach the circulation of the fetus. In recent years, strategies that exploit the transplacental delivery of antigen/IgG complexes or of Fc-fused proteins have been validated in mouse models of human diseases to impose antigen-specific tolerance, particularly in the case of Fc-fused factor VIII (FVIII) domains in hemophilia A mice or pre-pro-insulin (PPI) in the case of preclinical models of type 1 diabetes (T1D). The present review summarizes the mechanisms underlying the FcRn-mediated transcytosis of IgGs, the physiopathological relevance of this phenomenon, and the repercussion for drug delivery and shaping of the immune system during its ontogeny.

Chromosome 19 microRNA cluster enhances cell reprogramming by inhibiting epithelial-to-mesenchymal transition

During implantation, cytotrophoblasts undergo epithelial-to-mesenchymal transition (EMT) as they differentiate into invasive extravillous trophoblasts (EVTs). The primate-specific microRNA cluster on chromosome 19 (C19MC) is exclusively expressed in the placenta, embryonic stem cells and certain cancers however, its role in EMT gene regulation is unknown. In situ hybridization for miR-517a/c, a C19MC cistron microRNA, in first trimester human placentas displayed strong expression in villous trophoblasts and a gradual decrease from proximal to distal cell columns as cytotrophoblasts differentiate into invasive EVTs. To investigate the role of C19MC in the regulation of EMT genes, we employed the CRISPR/dCas9 Synergistic Activation Mediator (SAM) system, which induced robust transcriptional activation of the entire C19MC cistron and resulted in suppression of EMT associated genes. Exposure of human iPSCs to hypoxia or differentiation of iPSCs into either cytotrophoblast-stem-like cells or EVT-like cells under hypoxia reduced C19MC expression and increased EMT genes. Furthermore, transcriptional activation of the C19MC cistron induced the expression of OCT4 and FGF4 and accelerated cellular reprogramming. This study establishes the CRISPR/dCas9 SAM as a powerful tool that enables activation of the entire C19MC cistron and uncovers its novel role in suppressing EMT genes critical for maintaining the epithelial cytotrophoblasts stem cell phenotype.

The effect of antenatal depression and antidepressant treatment on placental tissue: a protein-validated gene expression study

Background

Antenatal depression affects 10–20% of pregnant women. Around 2–4% of European pregnant women use antidepressant treatment, most commonly selective serotonin reuptake inhibitors (SSRIs). Poor pregnancy outcomes, such as preterm birth and low birth weight, have been described in women with antenatal depression and in pregnant women on SSRI treatment. However, the effects of antenatal depression and antidepressant treatment on the placenta are largely unknown. The aim of this work was to compare placental gene and protein expression in healthy women, women with untreated antenatal depression and women on antidepressant treatment during pregnancy.

Methods

Placental samples from 47 controls, 25 depressed and 45 SSRI-treated women were analysed by means of qPCR using custom-designed TaqMan low-density arrays (TLDAs) for 44 genes previously known to be involved in the pathophysiology of depression, and expressed in the placenta. Moreover, placental protein expression was determined by means of immunohistochemistry in 37 healthy controls, 13 women with untreated depression and 21 women on antidepressant treatment. Statistical comparisons between groups were performed by one-way ANOVA or the Kruskal–Wallis test.

Results

Nominally significant findings were noted for HTR1A and NPY2R, where women with untreated depression displayed higher gene expression than healthy controls (p < 0.05), whereas women on antidepressant treatment had similar expression as healthy controls. The protein expression analyses revealed higher expression of HTR1A in placentas from women on antidepressant treatment, than in placentas from healthy controls (p < 0.05).

Conclusion

The differentially expressed HTR1A, both at the gene and the protein level that was revealed in this study, suggests the involvement of HTR1A in the effect of antenatal depression on biological mechanisms in the placenta. More research is needed to elucidate the role of depression and antidepressant treatment on the placenta, and, further, the effect on the fetus.

Perspective: L-arginine and L-citrulline Supplementation in Pregnancy: A Potential Strategy to Improve Birth Outcomes in Low-Resource Settings

The available data support the hypothesis that L-arginine or L-citrulline supplementation would be suitable for implementation in resource-constrained settings and will enhance placental vascular development and improve birth outcomes. In resource-constrained settings, the rates of adverse birth outcomes, including fetal growth restriction, preterm birth, and low birth weight, are disproportionately high. Complications resulting from preterm birth are now the leading cause of mortality in children <5 y of age worldwide. Despite the global health burden of adverse birth outcomes, few effective interventions are currently available and new strategies are urgently needed, especially for low-resource settings. L-arginine is a nutritionally essential amino acid in pregnancy and an immediate precursor of nitric oxide. During pregnancy, placental and embryonic growth increases the demand for L-arginine, which can exceed endogenous synthesis of L-arginine from L-citrulline, necessitating increased dietary intake. In many low-resource settings, dietary intake of L-arginine in pregnancy is inadequate owing to widespread protein malnutrition and depletion of endogenous L-arginine due to maternal infections, in particular malaria. Here we examine the role of the L-arginine-nitric oxide biosynthetic pathway in pregnancy including placental vascular development and fetal growth. We review the evidence for the relations between altered L-arginine bioavailability and pregnancy outcomes, and strategies for arginine supplementation in pregnancy. Existing studies of L-arginine supplementation in pregnancy in high-resource settings have shown improved maternal and fetal hemodynamics, prevention of pre-eclampsia, and improved birth outcomes including higher birth weight and longer gestation. Arginine supplementation studies now need to be extended to pregnant women in low-resource settings, especially those at risk of malaria.

Persistent free-floating pelvic trophoblastic cysts following an interstitial ectopic pregnancy

Persistent trophoblast after ectopic pregnancy has been demonstrated at the surgical site or as peritoneal implants. A 37-year-old woman (G5P2) experienced persistently low levels of beta-human chorionic gonadotropin (hCG) after surgical treatment for an interstitial pregnancy. Evaluation for persistent trophoblast, gestational trophoblastic neoplasm and heterophilic antibodies was negative. After 15 months without resolution, she elected for hysterectomy. We found four smooth, freely floating avascular cysts intraoperatively; pathological evaluation identified the cysts as trophoblastic tissue. Serum beta-hCG resolved postoperatively and remained negative at 1 year. Our case demonstrates the novel finding of trophoblastic tissue existing as free-floating cysts in the peritoneal cavity. With appropriate suspicion, these cysts can be identified on radiologic investigation and removed laparoscopically.

Mature naïve B cells are retained in the placental intervillous blood and positively associate with specific chemokines in full-term healthy pregnancy

PROBLEM

Circulating B-cell numbers are lower during pregnancy compared with non-pregnant women, but the underlying reasons for this are unknown. Pregnancy-related hormones could influence B-cell lymphopoiesis in the bone marrow, but B cells may also be recruited to the placenta. To investigate the latter, we examined whether the proportions of total B cells and B cells at different maturational stages in placental intervillous blood (IVB) differ compared with peripheral blood (PB).

METHOD OF STUDY

From 23 paired samples of PB and IVB following full-term healthy pregnancies, total B cells and immature/transitional, mature/naïve, and memory B cells were identified by flow cytometry. Chemokine levels in blood were analyzed using a Luminex assay. Placental explant-derived supernatant was assayed for B-cell chemotactic activity.

RESULTS

The proportions of total B cells and mature/naïve B cells were significantly higher in IVB relative to PB, while the fractions of immature/transitional cells and memory B cells were higher in PB. Multivariate factor analysis demonstrated that a specific chemokine profile in IVB, including CCL20, positively associated with higher proportions of mature/naïve B cells in the intervillous space. All B cells expressed CCR6, the corresponding receptor for CCL20, but the intensity of CCR6 expression was significantly higher in mature/naïve B cells relative to immature/transitional B cells. Migration assays showed that placental explant-derived supernatants attract B cells.

CONCLUSION

These results indicate that B cells, and mature/naïve B cells in particular, are retained in the intervillous blood in response to certain chemokines produced by the placenta during late healthy pregnancy.

Zika virus: Molecular responses and tissue tropism in the mammalian host

Zika virus (ZIKV) outbreaks have raised alarm because of reports of congenital Zika virus syndrome in infants. The virus is also known to cause the debilitating Guillain-Barré syndrome in adults. As a result, extensive research has been carried out on the virus over the past few years. To study the molecular responses of viral infectivity in mammals, in vitro two-dimensional and three-dimensional cellular models have been employed. The in vivo models of mouse, pig, chicken, and nonhuman primates are primarily used to investigate the teratogenicity of the virus, to study effects of the virus on specific tissues, and to study the systemic effects of a proposed antiviral agent. The virus exhibits wide tissue tropism in the mammalian host. The major host tissues of viral persistence and propagation are neural tissue, ocular tissue, testicular tissue and placental tissue. An understanding of the function of viral components, viral replication cycle, and the molecular responses elicited in the host tissues is imperative for designing antiviral treatment strategies and for development of vaccines. This review provides an update on ZIKV research models and mammalian host responses with respect to ZIKV tissue infection.

Differential adhesion and fibrinolytic activity of mesenchymal stem cells from human bone marrow, placenta, and Wharton's jelly cultured in a fibrin hydrogel

Mesenchymal stem cells isolated from different tissues should share associated markers and the capability to differentiate to mesodermal lineages. However, their behavior varies in specific microenvironments. Herein, adhesion and fibrinolytic activity of mesenchymal stem cells from placenta, bone marrow, and Wharton’s jelly were evaluated in fibrin hydrogels prepared with nonpurified blood plasma and compared with two-dimensional cultures. Despite the source, mesenchymal stem cells adhered through focal adhesions positive for vinculin and integrin αV in two dimensions, while focal adhesions could not be detected in fibrin hydrogels. Moreover, some cells could not spread and stay rounded. The proportions of elongated and round phenotypes varied, with placenta mesenchymal stem cells having the lowest percentage of elongated cells (~10%). Mesenchymal stem cells degraded fibrin at distinct rates, and placenta mesenchymal stem cells had the strongest fibrinolytic activity, which was achieved principally through the plasminogen–plasmin axis. These findings might have clinical implications in tissue engineering and wound healing therapy.

Rural and urban differences in prenatal exposure to essential and toxic elements

Excess or inadequate levels of inorganic ions may induce significant acute and long-term irreversible dysfunction in humans. The fetus and placenta are particularly vulnerable to toxins due to the immaturity of the blood-brain barrier and diminished biotransformation enzymatic activity. A comparative cross-sectional study was conducted on 172 pregnant women, 79 rural, and 93 urban. Umbilical cord blood was collected at the time of delivery and analyzed for 20 inorganic elements. Significant differences were found between urban and rural samples for two elements where copper (Cu) and molybdenum (Mo) were higher in urban samples. No marked differences between groups occurred for: arsenic, barium, cadmium, calcium, cobalt, lead, lithium, magnesium, manganese, mercury, selenium, strontium, or zinc. All samples were devoid of platinum, silver, thallium or uranium. Data demonstrated significant differences in urban and rural prenatal exposure to Cu and Mo. Further study is needed to determine if there is a causal link between neonatal outcomes and prenatal exposure to these elements.

Gestational Hypoxia and Developmental Plasticity

Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.