Molecular Targets of Aspirin and Prevention of Preeclampsia and Their Potential Association with Circulating Extracellular Vesicles during Pregnancy

Trimester and severity of SARS-CoV-2 infection during pregnancy and risk of hypertensive disorders in pregnancy

OBJECTIVE

SARS-CoV-2 infection during pregnancy has been linked with an increased risk of hypertensive disorders of pregnancy (HDP). The aim of this study was to examine how both trimester and severity of SARS-CoV-2 infection impact HDP.

METHODS

We conducted a cohort study of SARS-CoV-2-infected individuals during pregnancy (n = 205) and examined the association between trimester and severity of infection with incidence of HDP using modified Poisson regression models to calculate risk ratios (RR) and 95% confidence intervals (CI). We stratified the analysis of trimester by severity to understand the role of timing of infection among those with similar symptomatology and also examined timing of infection as a continuous variable.

RESULTS

Compared to a reference cohort from 2018, SARS-CoV-2 infection did not largely increase the risk of HDP (RR: 1.17; CI:0.90, 1.51), but a non-statistically significant higher risk of preeclampsia was observed (RR: 1.33; CI:0.89, 1.98), in our small sample. Among the SARS-CoV-2 cohort, severity was linked with risk of HDP, with infections requiring hospitalization increasing the risk of HDP compared to asymptomatic/mild infections. Trimester of infection was not associated with risk of HDP, but a slight decline in the risk of HDP was observed with later gestational week of infection. Among patients with asymptomatic or mild symptoms, SARS-CoV-2 in the first trimester conferred a higher risk of HDP compared to the third trimester (RR: 1.70; CI:0.77, 3.77), although estimates were imprecise.

CONCLUSION

SARS-CoV-2 infection in early pregnancy may increase the risk of HDP compared to infection later in pregnancy.

CD169+ Macrophages Mediate the Immune Response of Allergic Rhinitis Through the Keap1/Nrf2/HO-1 Axis

CD169+ macrophages are a newly defined macrophage subpopulation that can recognize and bind with other cells through related ligands, playing an essential role in antigen presentation and immune tolerance. However, its role in Allergic Rhinitis (AR) is still unclear. To investigate the characteristics of CD169+ macrophages in AR, this work first detects their expression patterns in the nasal mucosa of clinical patients. These results show a significant increase in CD169+ macrophages in the nasal mucosa of patients with AR. Subsequently, this work establishes an animal AR model using CD169 transgenic mice and compared the advantages of the two models. Moreover, this work also demonstrates the effects of CD169 knockout on eosinophils, Th cells, Treg cells, and the migration of dendritic cells (DCs). In addition, this metabolomic data shows that CD169+ macrophages can upregulate alanine production and increase reactive oxygen species (ROS) levels. This process may be mediated through the Keap1/Nrf2/HO-1 signaling pathway. In addition, this work also finds that SLC38A2 plays an essential role in the process of CD169+ macrophages promoting alanine uptake by DCs. This study confirms that CD169+ macrophages can upregulate their internal alanine production and increase ROS levels through the Keap1/Nrf2/HO-1 axis, playing an irreplaceable role in AR.

Understanding the role of soluble proteins and exosomes in non-invasive urine-based diagnosis of preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy that can lead to stillbirth and preterm birth if not treated promptly. Currently, the diagnosis of preeclampsia relies on clinical symptoms such as hypertension and proteinuria, along with invasive blood tests. Here, we investigate the role of soluble proteins and exosomes in noninvasive diagnosing preeclampsia non-invasively using maternal urine and urine-derived exosomes. We quantified the levels of particles and the presence of TSG101 and CD63 in urine and urinary exosomes via the biologically intact exosome separation technology (BEST) platform. Then, we obtained higher levels of soluble proteins such as fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) from urine as it was than urinary exosomes. Compared to commercial blood tests, the sensitivity of the sFlt-1/PlGF ratio was found to be 4.0 times higher in urine tests and 1.5 times higher in tests utilizing urine-derived exosomes. Our findings offer promising possibilities for the early and non-invasive identification of high-risk individuals at risk of preeclampsia, allowing for comprehensive preventive management.

Update on Preeclampsia and Hypertensive Disorders of Pregnancy

There have been recent advances in the prevention, diagnosis, and management of hypertensive disorders of pregnancy which complicate approximately 16% of pregnancies in the United States. Initiation of low-dose aspirin by 16 weeks' gestation reduces preeclampsia in high-risk women. The Food and Drug Administration approved the use of the soluble fms-like tyrosine kinase 1/placental growth factor ratio for the short-term prediction of preeclampsia. Pregnancy outcomes are improved in women with chronic hypertension when antihypertensives are initiated at a threshold blood pressure of 140/90 mm Hg. Women with prior preeclampsia have increased cardiovascular disease risk and should receive risk reduction counseling.

Exogenous Hydrogen Sulfide Prevents Necroptosis by Inhibiting p38MAPK Pathway Activation in JEG-3 Trophoblast Cells: A Role in Preeclampsia

OBJECTIVES

Necroptosis, a form of programmed cell death, can occur in the placenta of patients with preeclampsia (PE). Hydrogen sulfide (H2S) can inhibit necroptosis of human umbilical vein endothelial cells under the high glucose-induced injury. Whether H2S can protect trophoblasts against necroptosis underlying PE has not been elucidated. This study aimed to explore the protective role of H2S in trophoblast cells against necroptosis underlying PE.

DESIGN

This is an in vitro experimental study.

PARTICIPANTS

A total of 10 pregnant women with severe PE and 10 matched control normotensive pregnant women were included. The placenta tissues were extracted from participators. The human JEG-3 trophoblasts were commercially available.

METHODS

The expression and localization of necrotic proteins were assayed in human placenta samples, and the effect of necrotic cell death on the proliferation and apoptosis of human JEG-3 trophoblasts was evaluated. The component expressions of inflammatory cytokine and p38MAPK signaling pathway were measured in samples pretreated with or without NaHS (H2S donor) and SB203580 (p38 inhibitor).

RESULTS

RIPA1, RIPA3, and p-p38 levels were significantly higher in PE placental tissue, whereas cystathionine β-synthase expression was decreased. In JEG-3 trophoblasts, necroptosis increased apoptotic cell numbers, suppressed cell proliferation, increased inflammatory cytokine expression, and increased p38MAPK activation, which can be prevented by NaHS.

LIMITATIONS

In the present study, we did not provide sufficient evidence that necroptosis was a part of the pathogenesis of PE.

CONCLUSIONS

We proposed the putative role of necroptosis in early-onset PE, reflected by the blockage of caspase-8/3 and increased expression of RIPA1 and RIPA3 in PE placenta tissues. Furthermore, we demonstrated that exogenous H2S protected cytotrophoblasts against ceramide-induced necroptosis via the p38MAPK pathway.

Placenta-mediated pregnancy complications in women with a history of late fetal loss and placental infarction without thrombophilia: risk of recurrence and efficacy of pharmacological prophylactic interventions. A 10-year retrospective study

PURPOSE

To evaluate the risk of recurrence of severe placenta-mediated pregnancy complications and compare the efficacy of two different anti-thrombotic regimens in women with a history of late fetal loss without thrombophilia.

PATIENTS AND METHODS

We performed a 10-year retrospective observational study (2008-2018) analyzing a cohort of 128 women who suffered from pregnancy fetal loss (>20 weeks of gestational age) with histological evidence of placental infarction. All the women tested negative for congenital and/or acquired thrombophilia. In their subsequent pregnancies, 55 received prophylaxis with acetylsalicylic acid (ASA) only and 73 received ASA plus low molecular weight heparin (LMWH).

RESULTS

Overall, one-third of all pregnancies (31%) had adverse outcomes related to placental dysfunction: pre-term births (25% <37 weeks, 5.6% <34 weeks), newborns with birth weight <2500 g (17%), and newborns small for gestational age (5%). The prevalence of placental abruption, early and/or severe preeclampsia, and fetal loss >20 weeks were 6%, 5%, and 4% respectively. We found a risk reduction for combination therapy (ASA plus LMWH) compared with ASA alone for delivery <34 weeks (RR 0.11, 95% CI: 0.01-0.95 p = 0.045) and a trend for the prevention of early/severe preeclampsia (RR 0.14, 95% CI: 0.01-1.18, p = 0.0715), while no statistically significant difference was observed for composite outcomes (RR 0.51, 95%CI: 0.22-1.19, p = 0.1242). An absolute risk reduction of 5.31% was observed for the ASA plus LMWH group. Multivariate analysis confirmed a risk reduction for delivery <34 weeks (RR 0.32, 95% CI 0.16-0.96 p = 0.041).

CONCLUSION

In our study population, the risk of recurrence of placenta-mediated pregnancy complications is substantial, even in the absence of maternal thrombophilic conditions. A reduction of the risk of delivery <34 weeks was detected in the ASA plus LMWH group.

Disrupted Balance of the Oxidant-Antioxidant System in the Pathophysiology of Female Reproduction: Oxidative Stress and Adverse Pregnancy Outcomes

The significance of oxidative stress in the pathophysiology of male reproductive processes has been closely studied in the last two decades. Recently, it has become clear that oxidative stress can lead to numerous pathological conditions during female reproductive processes as well, contributing to the development of endometriosis, polycystic ovary syndrome and various forms of infertility. During pregnancy, physiological generation of reactive oxygen species (ROS) occurs in association with several developmental processes including oocyte maturation and implantation. An overproduction of ROS can lead to disturbances in fetal development and increases the risk for missed abortion, intrauterine growth restriction, pre-eclampsia, premature delivery and gestational diabetes. Our review focuses on the etiological role of the disrupted oxidant-antioxidant system during human gestation as it relates to adverse pregnancy outcomes.

Evaluation of a Maternal Plasma RNA Panel Predicting Spontaneous Preterm Birth and Its Expansion to the Prediction of Preeclampsia

Preterm birth is the principal contributor to neonatal death and morbidity worldwide. We previously described a plasma cell-free RNA panel that between 16 and 20 weeks of pregnancy had potential to predict spontaneous preterm birth (sPTB) ≤ 32 weeks caused by preterm labor (PTL) or preterm premature rupture of membranes (PPROM). The present study had three objectives: (1) estimate the RNA panel prognostic accuracy for PTL/PPROM ≤ 32 weeks in a larger series; (2) improve accuracy by adding clinical characteristics to the predictive model; and (3) examine the association of the RNA panel with preeclampsia. We studied 289 women from Memphis TN prospectively sampled 16.0-20.7 weeks and found: (1) PSME2 and Hsa-Let 7g were differentially expressed in cases of PTL/PPROM ≤ 32 weeks and together provided fair predictive accuracy with AUC of 0.76; (2) combining the two RNAs with clinical characteristics improved good predictive accuracy for PTL/PPROM ≤ 32 weeks (AUC 0.83); (3) NAMPT and APOA1 were differentially expressed in women with 'early-onset preeclampsia' (EOP) and together provided good predictive accuracy with AUC of 0.89; and (4) combining the two RNAs with clinical characteristics provided excellent predictive accuracy (AUC 0.96). Our findings suggest an underlying common pathophysiological relationship between PTL/PPROM ≤ 32 weeks and EOP and open inroads for the prognostication of high-risk pregnancies.

Efficacy and safety of low-dose aspirin combined with low-molecular-weight heparin in treatment of preeclampsia: a meta-analysis and systematic review

INTRODUCTION

The role of low-dose aspirin combined with low-molecular-weight heparin (LMWH) in the treatment of preeclampsia (PE) remains unclear. We aimed to assess the efficacy and safety of low-dose aspirin combined with LMWH in PE treatment, to provide evidence for clinical PE management.

MATERIAL AND METHODS

We searched PubMed and other databases for randomized controlled trials (RCTs) on the effects and safety of low-dose aspirin and LMWH in the treatment of PE up to January 31, 2021. Two researchers strictly followed the inclusion and exclusion criteria to independently conduct the literature screening, data extraction and quality evaluation. We used RevMan 5.3 statistical software for synthesized analysis.

RESULTS

A total of 8 RCTs involving 861 patients were included. The synthesized outcome indicated that the differences in systolic blood pressure (MD = -10.61, 95% CI: -13.19 - -8.02), diastolic blood pressure (MD = -9.24, 95% CI: -14.49- -4.00), 24-hour urinary protein (MD = -2.24, 95% CI: -3.97- -0.50), prothrombin time (MD = 1.42, 95% CI: 0.53-2.32), activated partial thromboplastin time (MD = 2.91, 95% CI: 2.06-3.75), FIB (MD = -1.24, 95% CI: -1.32- -1.15), and adverse perinatal outcomes (MD = 0.41, 95% CI: 0.20-0.85) between the two groups were statistically significant (all p < 0.05), while the difference in the adverse reactions of pregnant women (MD = 0.44, 95% CI: 0.18-1.10) between the two groups was not statistically significant (p = 0.08). No publication bias was detected in all the synthesized outcomes (all p > 0.05).

CONCLUSIONS

Low-dose aspirin combined with LMWH treatment of PE may be advantageous to improve blood pressure, 24-hour proteinuria and coagulation function, and it may reduce the adverse reactions in pregnant women without increasing adverse perinatal outcomes.

Hypoxia-inducible factor-1β is essential for upregulation of the hypoxia-induced FLT1 gene in placental trophoblasts

Placental hypoxia and increased levels of maternal blood anti-angiogenic protein, soluble fms-like tyrosine kinase-1 (sFLT1), are associated with the pathogenesis of pre-eclampsia. We have demonstrated that hypoxia-inducible factor (HIF)-2α mediates the upregulation of the hypoxia-induced FLT1 gene in trophoblasts and their cell lines. Here, we investigated the involvement of HIF-1β, which acts as a dimerization partner for HIF-α, in the upregulation of the FLT1 gene via hypoxia. We confirmed the interactions between HIF-1β and HIF-2α in the nuclei of BeWo, JAR and JEG-3 cells under hypoxia via co-immunoprecipitation. We found that hypoxia-induced upregulation of the FLT1 gene in BeWo cells and secretion of sFLT1 in human primary trophoblasts were significantly reduced by siRNAs targeting HIF-1β. Moreover, the upregulation of the FLT1 gene in BeWo cells induced by dimethyloxaloylglycine (DMOG) was also inhibited by silencing either HIF-2α or HIF-1β mRNA. It was recently shown that DNA demethylation increases both basal and hypoxia-induced expression levels of the FLT1 gene in three trophoblast-derived cell lines. In the demethylated BeWo cells, siRNAs targeting HIF-2α and HIF-1β suppressed the further increase in the expression levels of the FLT1 gene due to hypoxia or treatment with DMOG. However, luciferase reporter assays and bisulfite sequencing revealed that a hypoxia response element (-966 to -962) of the FLT1 gene is not involved in hypoxia or DMOG-induced upregulation of the FLT1 gene. These findings suggest that HIF-1β is essential for the elevated production of sFLT1 in the hypoxic trophoblasts and that the HIF-2α/HIF-1β complex may be a crucial therapeutic target for pre-eclampsia.

Prothrombotic state associated with preeclampsia

PURPOSE OF REVIEW

Preeclampsia is a common complication of pregnancy and contributes significantly to maternal and fetal morbidity and mortality. A protective hypercoagulable state is often developed during late pregnancy and can evolve into a prothrombotic state in patients with preeclampsia. The underlying mechanism of this prothrombotic transition remains poorly understood. We discuss recent progress in understanding the pathophysiology of preeclampsia and associated prothrombotic state.

RECENT FINDINGS

The hypercoagulable state developed during pregnancy is initiated by placental factors and progresses into the prothrombotic state in preeclampsia when the placenta is subjected ischemic and oxidative injuries. The cause of the preeclampsia-induced prothrombotic state is multifactorial, involving not only placental factors but also maternal conditions, which include genetic predisposition, preexisting medical conditions, and conditions acquired during pregnancy. Endotheliopathy is the primary pathology of preeclampsia and contributes to the prothrombotic state by inducing the dysregulation of coagulation, platelets, and adhesive ligands.

SUMMARY

Patients with preeclampsia often develop a severe prothrombotic state that predisposes them to life-threatening thrombosis and thromboembolism during and after pregnancy. Early recognition and treatment of this prothrombotic state can improve maternal and infant outcomes of preeclampsia patients.

The Road to Low-Dose Aspirin Therapy for the Prevention of Preeclampsia Began with the Placenta

The road to low-dose aspirin therapy for the prevention of preeclampsia began in the 1980s with the discovery that there was increased thromboxane and decreased prostacyclin production in placentas of preeclamptic women. At the time, low-dose aspirin therapy was being used to prevent recurrent myocardial infarction and other thrombotic events based on its ability to selectively inhibit thromboxane synthesis without affecting prostacyclin synthesis. With the discovery that thromboxane was increased in preeclamptic women, it was reasonable to evaluate whether low-dose aspirin would be effective for preeclampsia prevention. The first clinical trials were very promising, but then two large multi-center trials dampened enthusiasm until meta-analysis studies showed aspirin was effective, but with caveats. Low-dose aspirin was most effective when started <16 weeks of gestation and at doses >100 mg/day. It was effective in reducing preterm preeclampsia, but not term preeclampsia, and patient compliance and patient weight were important variables. Despite the effectiveness of low-dose aspirin therapy in correcting the placental imbalance between thromboxane and prostacyclin and reducing oxidative stress, some aspirin-treated women still develop preeclampsia. Alterations in placental sphingolipids and hydroxyeicosatetraenoic acids not affected by aspirin, but with biologic actions that could cause preeclampsia, may explain treatment failures. Consideration should be given to aspirin's effect on neutrophils and pregnancy-specific expression of protease-activated receptor 1, as well as additional mechanisms of action to prevent preeclampsia.

Effect of L-Arginine supplementation in pregnant women with chronic hypertension and previous placenta vascular disorders receiving Aspirin prophylaxis: a randomized control trial

BACKGROUND

The aim of the study is to evaluate the effects of supplementation with Arginine (L-Arg) 3g, (together with Magnesium (Mg) 350 mg and Salicilate (Sal) 100 mg) on maternal blood pressure (BP), uterine artery doppler PI and neonatal outcomes in women with high-risk pregnancy for chronic hypertension (CH) and other previous placenta vascular disorders (PVD) already treated with low dose of aspirin (LDA), as recommended by guidelines.

METHODS

We enrolled women affected by CH and other previous PVD referred to the High-Risk Clinic of the Mother-Infant Department of the University of Modena and Reggio Emilia from September 2017 to June 2019. The study design was a controlled, randomized trial of oral supplementation of L-Arg 3g (together with Mg 350 mg and Sal extract 100 mg) + LDA 100 mg/die versus only LDA 100 mg/die. Inclusion criteria were: singleton pregnancy; diagnosis of chronic hypertension, previous preeclampsia < 34 weeks, previous intrauterine growth restriction (IUGR) < 10° centile or previous stillbirth (SB) related to placenta vascular disorders; gestational age < 14 weeks. Each woman was enrolled between 12-14 weeks gestation and underwent 24-h ambulatory BP monitoring with an automatic device (SpaceLab 92710, Critikon, WA), repeated at 18-20th and 24-26th weeks. Moreover Uterine artery Doppler ultrasound evaluation including PI were performed at 18-20 weeks gestation and repeated at 24-26th weeks. Pregnancy outcomes data were collected in a password protected database.

RESULTS

Seventy-nine women agreed to participate in the study. No significant differences between the demographic characteristics in the two groups at enrollment (Group LDA + L-Arg: 30 patients versus Group LDA: 49 patient) were found. In the LDA-L-Arg group there isn't the significant increase in both systolic (127.22 ± 12.02 and 132.75 ± 7.51 mmHg, p=0.002) and diastolic (75.85 ± 8.53 and 83.63 ± 6.05 mmHg, p=0.0000) BP values at 24-26 weeks reveled in the LDA group. The value of the Uterine Artery Doppler median PI > 95° centile at 24-26 weeks show a significant reduction in the LDA+L-Arg group respect the LDA group (7 women, 23.3% vs 21 women, 42.9%; p=0.04). A significantly lower percentage of women received new antihypertensive drugs in the LDA+ L-Arg group than the LDA group (6.7% vs 24.5%) (p= 0.02). There was neither statistically significant difference in perinatal outcomes between 2 groups, except for trend of significance.

CONCLUSIONS

Although we found only trends of improvements of perinatal outcomes in LDA+LArg group, considering the promising results on BP values, uterine artery PI and the low need to start a new antihypertensive treatment, thus the resulting impact in reducing pregnancy medicalization, number of maternal-fetal well-being monitoring visits and the need of induction of labour, we believe that further studies should be performed to enlarge our observation and clarify the role of L-Arg 3g supplementation as a protective integration in high-risk pregnancies already in prophylaxis with LDA.

Aspirin facilitates trophoblast invasion and epithelial-mesenchymal transition by regulating the miR-200-ZEB1 axis in preeclampsia

Preeclampsia is a severe gestational hypertensive disorder that occurs after 20 weeks' of gestation. It involves several maternal systems, such as cardiovascular, renal, coagulatory systems, and poses a major threat to the maternal and fetal health. Recent clinical evidence showed that aspirin is an effective preventative treatment for reducing the incidence of premature preeclampsia among high-risk pregnant women, however, the mechanism of drug action is not clear. miR-200 family has been shown to be associated with preeclampsia and upregulated in the plasma and placenta of preeclamptic patients. Here we revealed that miR-200 family inhibited trophoblast invasion and epithelial-mesenchymal transition (EMT) process by stimulating epithelial marker expression (E-cadherin and ZO-1) and repressing mesenchymal marker expression (ZEB1 and TGFβ1). Similarly, EMT markers in the placenta of preeclamptic patients showed higher E-cadherin and lower ZEB1 and TGF-β1 protein expression. Moreover, aspirin was shown to suppress miR-200 family and these miR-200 family-mediated cell functions, including cell invasion and EMT changes, were completely reversed. In conclusion, this study demonstrates the effect of miR-200 family on trophoblast invasion and EMT. For the first time, aspirin was shown to fully reverse miR-200-mediated trophoblast biology and act through the network signaling of TGF-β1/ZEB1/miR-200. These results provide a plausible mechanism explaining aspirin's effect on preeclampsia prevention and a therapeutic target for disease intervention.

Overexpressed Hsa_circ_0001326 Contributes to the Decreased Cell Viability in SWAN71 Cells by Regulating MiR-186-5p/p27 Kip1 Axis

Preeclampsia (PE) is a severe pregnancy-specific complication responsible for a majority of maternal and fetal mortality. The dysfunction of trophoblast cells is known to be associated with the etiology of PE. Moreover, elevated expression of hsa_circ_0001326 was found in patients with PE without elucidating specific mechanisms. Thus, this study aimed to investigate the role of hsa_circ_0001326 in the dysfunction of trophoblast cells in vitro. Human trophoblast SWAN71 cells were used in this study. Cell proliferation, apoptosis and cell cycle were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, cell counting kit-8 assay, Annexin V/propidium iodide (PI) staining and flow cytometry, respectively. Dual luciferase assay was performed to validate the predicted targets. Additionally, Western blot was conducted for protein detection. The results indicated overexpression (OE) of hsa_circ_0001326 remarkably decreased the viability and proliferation of SWAN71 cells. MiR-186-5p was identified as the target of hsa_circ_0001326. Meanwhile, p27 Kip1 was validated as the target of hsa_miR-186-5p. Moreover, the increased apoptosis and decreased migration induced by hsa_circ_0001326 OE were inhibited by p27 Kip1 knockdown. Hsa_circ_0001326 OE upregulated p27 Kip1 and cleaved caspase3 and downregulated CDK2 and cyclin E1 in cells, while these phenomena were reversed by p27 Kip1 knockdown. In addition, hsa_circ_0001326 OE induced G0/G1 cell cycle arrest was also attenuated in the presence of p27 Kip1 knockdown. Taken together, hsa_circ_0001326 OE contributed to the decreased viability of SWAN71 cells by targeting miR-186-5p via upregulation of p27 Kip1. Our findings were helpful to uncover the pathophysiological process of PE, as well as inspire the development of novel targeted therapy against PE.

Immune Regulation, Maternal Infection, Vaccination, and Pregnancy Outcome

About 12.5% of all maternal deaths in the United States are due to infectious causes. This proportion, although stable during the past three decades, represents an increase in infectious causes of mortality, as the overall mortality rate in U.S. pregnant women had increased steadily during that same period. During healthy pregnancies, a delicate immunological balance-in which a mother's immune system tolerates the semi-allogeneic fetus yet maintains immune competency against infectious agents-is achieved and maintained. This immunological paradigm, however, results in increased susceptibility to infectious diseases during pregnancy, particularly in later stages and during the early postpartum period. The inflammatory process induced by these infectious insults, as well as some noninfectious insults, occurring during pregnancy can disrupt this carefully achieved balance and, in turn, lead to a state of rampant inflammation, immune activation, and dysregulation with deleterious health outcomes for the mother and fetus. Elucidating mechanisms contributing to the disruption of this immunologic homeostasis, and its disruption by infectious pathogens, might offer opportunities for interventions to reduce maternal and fetal morbidity and mortality.

The promise of placental extracellular vesicles: models and challenges for diagnosing placental dysfunction in utero†

Monitoring the health of a pregnancy is of utmost importance to both the fetus and the mother. The diagnosis of pregnancy complications typically occurs after the manifestation of symptoms, and limited preventative measures or effective treatments are available. Traditionally, pregnancy health is evaluated by analyzing maternal serum hormone levels, genetic testing, ultrasonographic imaging, and monitoring maternal symptoms. However, researchers have reported a difference in extracellular vesicle (EV) quantity and cargo between healthy and at-risk pregnancies. Thus, placental EVs (PEVs) may help to understand normal and aberrant placental development, monitor pregnancy health in terms of developing placental pathologies, and assess the impact of environmental influences, such as infection, on pregnancy. The diagnostic potential of PEVs could allow for earlier detection of pregnancy complications via noninvasive sampling and frequent monitoring. Understanding how PEVs serve as a means of communication with maternal cells and recognizing their potential utility as a readout of placental health have sparked a growing interest in basic and translational research. However, to date, PEV research with animal models lags behind human studies. The strength of animal pregnancy models is that they can be used to assess placental pathologies in conjunction with isolation of PEVs from fluid samples at different time points throughout gestation. Assessing PEV cargo in animals within normal and complicated pregnancies will accelerate the translation of PEV analysis into the clinic for potential use in prognostics. We propose that appropriate animal models of human pregnancy complications must be established in the PEV field.

Exploiting the placenta for nanoparticle-mediated drug delivery during pregnancy

A major challenge to treating diseases during pregnancy is that small molecule therapeutics are transported through the placenta and incur toxicities to the developing fetus. The placenta is responsible for providing nutrients, removing waste, and protecting the fetus from toxic substances. Thus, the placenta acts as a biological barrier between the mother and fetus that can be exploited for drug delivery. Nanoparticle technologies provide the opportunity for safe drug delivery during pregnancy by controlling how therapeutics interact with the placenta. In this Review, we present nanoparticle drug delivery technologies specifically designed to exploit the placenta as a biological barrier to treat maternal, placental, or fetal diseases exclusively, while minimizing off-target toxicities. Further, we discuss opportunities, challenges, and future directions for implementing drug delivery technologies during pregnancy.

Relevant Features of Polypharmacologic Human-Target Antimicrobials Discovered by Machine-Learning Techniques

Polypharmacologic human-targeted antimicrobials (polyHAM) are potentially useful in the treatment of complex human diseases where the microbiome is important (e.g., diabetes, hypertension). We previously reported a machine-learning approach to identify polyHAM from FDA-approved human targeted drugs using a heterologous approach (training with peptides and non-peptide compounds). Here we discover that polyHAM are more likely to be found among antimicrobials displaying a broad-spectrum antibiotic activity and that topological, but not chemical features, are most informative to classify this activity. A heterologous machine-learning approach was trained with broad-spectrum antimicrobials and tested with human metabolites; these metabolites were labeled as antimicrobials or non-antimicrobials based on a naïve text-mining approach. Human metabolites are not commonly recognized as antimicrobials yet circulate in the human body where microbes are found and our heterologous model was able to classify those with antimicrobial activity. These results provide the basis to develop applications aimed to design human diets that purposely alter metabolic compounds proportions as a way to control human microbiome.

Placental syncytiotrophoblast extracellular vesicles enter primary endothelial cells through clathrin-mediated endocytosis

INTRODUCTION

The aim was to investigate syncytiotrophoblast extracellular vesicle (STBEV) uptake mechanisms by primary endothelial cells, the effects on gene expression, cell activation as well as the effect of aspirin.

METHODS

The STBEVs were derived using the placental perfusion system, from normal or preeclamptic placentas. Endothelial uptake was analysed with flow cytometry. To elucidate uptake, different inhibitors were tested; Cytochalasin D, Chlorpromazine hydrochloride, Methyl-B-cyclodextrin, Dynasore and Wortmannin. Endothelial gene expression was evaluated using an endothelial cell biology qPCR array. Cell activation was studied by ICAM-1 surface expression after STBEV exposure, with and without aspirin treatment.

RESULTS

Normal and preeclamptic STBEV uptake was blocked in similar ways. Chlorpromazine, Dynasore and Wortmannin almost completely blocked STBEV uptake. Methyl-B-cyclodextrin blocked 45-60% of the uptake while Cytochalasin D did not block uptake at all. Neither normal nor preeclamptic STBEVs had any significant effects on endothelial gene expression. Normal STBEVs down-regulated cell surface protein ICAM-1 expression, with and without aspirin treatment. Aspirin had no effect on STBEV uptake or cellular gene expression on its own, however it down regulated ICAM-1 protein expression in combination with preeclamptic STBEV exposure.

DISCUSSION

STBEV uptake primarily occurred through clathrin-mediated endocytosis. The STBEVs had no significant effect on gene expression but did have effects on ICAM-1 surface expression. The prophylactic mechanisms of aspirin may be by preventing the endothelium from being activated by the preeclamptic STBEVs.

Exosomes as Messengers Between Mother and Fetus in Pregnancy

The ability of exosomes to transport different molecular cargoes and their ability to influence various physiological factors is already well known. An exciting area of research explores the functions of exosomes in healthy and pathological pregnancies. Placenta-derived exosomes were identified in the maternal circulation during pregnancy and their contribution in the crosstalk between mother and fetus are now starting to become defined. In this review, we will try to summarize actual knowledge about this topic and to answer the question of how important exosomes are for a healthy pregnancy.