Enhancement of trophoblast differentiation and survival by low molecular weight heparin requires heparin-binding EGF-like growth factor

The effect and mechanism of low-molecular-weight heparin on the decidualization of stromal cells in early pregnancy

OBJECTIVE

This study aimed to analyze the effect of low-molecular-weight heparin (LMWH) on the decidualization of stromal cells in early pregnancy and explore the effect of LMWH on pregnancy outcomes.

METHODS

Recurrent spontaneous abortion (RSA) mouse model (CBA/J × DBA/2) and normal pregnant mouse model (CBA/J × BALB/c) were established. The female mice were checked for a mucus plug twice daily to identify a potential pregnancy. When a mucus plug was found, conception was considered to have occurred 12 h previously. The pregnant mice were divided randomly into a normal pregnancy control group, an RSA model group, and an RSA + LMWH experimental group (n = 10 mice in each group). Halfway through the 12th day of pregnancy, the embryonic loss of the mice was observed; a real-time quantitative polymerase chain reaction was used to detect the messenger ribonucleic acid (mRNA) expressions of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) in the decidua of the mice. Additionally, the decidual tissues of patients with RSA and those of normal women in early pregnancy who required artificial abortion were collected and divided into an RSA group and a control group. Decidual stromal cells were isolated and cultured to compare cell proliferation between the two groups, and cellular migration and invasion were detected by membrane stromal cells. Western blotting was used to detect the protein expressions of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteinase- (MMP) 2, and MMP-7 in stromal cells treated with LMWH.

RESULTS

Compared with the RSA group, LMWH significantly reduced the pregnancy loss rate in the RSA mice (p < 0.05). Compared with the RSA group, the LMWH + RSA group had significantly higher expression levels of PRL and IGFBP1 mRNA (p < 0.01). LMWH promoted the proliferation, migration, and invasion of human decidual stromal cells; compared with the control group, the expression levels of MMP-2, MMP-7, cyclin D1, and PCNA proteins in the decidual stromal cells of the LMWH group increased (p < 0.05).

CONCLUSIONS

The use of LMWH can improve pregnancy outcomes by enhancing the proliferation and migration of stromal cells in early pregnancy and the decidualization of stromal cells.

The use of immunomodulation therapy in women with recurrent implantation failure undergoing assisted conception: A multicentre cohort study

PROBLEM

Recurrent implantation failure (RIF) after multiple embryo transfers remains a vexing problem and immunomodulators have been used with conflicting results. This study aims to assess the effect of immunomodulation therapy on live birth rate (LBR) in women with RIF undergoing assisted reproduction treatment (ART).

METHOD OF STUDY DESIGN

This is a retrospective cohort study in multicentre network of private assisted conception units in the UK. The study included women who had at least two failed attempts of embryo transfers at CARE fertility network in the period from 1997 to 2018. Women in the treatment group had immunomodulator drugs in the form of corticosteroids, low molecular weight heparin (LMWH), and intravenous intralipid (IVIL) infusions, either separately or in combination, after immunological testing, in addition to standard ART whilst women in the control group had only ART without immunomodulators. The primary outcome was LBR per cycle. Secondary outcomes included the rates of clinical pregnancy (CPR), cumulative live birth (CLBR), and miscarriage.

RESULTS

A total of 27 163 ART cycles fulfilled the inclusion criteria, of which 5083 had immunomodulation treatment in addition to standard ART treatment, and 22 080 had standard ART treatment alone. Women in the treatment group were significantly older (mean age 38.5 vs. 37.1 years, p < .001), and had a higher number of previous failed ART cycles (mean 4.3 vs. 3.8, p < .01). There was a higher LBR in women who received immunomodulation therapy when compared with the control group (20.9% vs. 15.8%, odds ratio [OR] 1.4, 95% confidence interval [CI] 1.29-1.53, p < .001). Multivariate regression analysis showed that immunomodulation treatment was a significant independent predictor of live birth after adjusting for other confounders (adjusted OR [aOR] 1.33, 95% CI 1.15-1.54, p < .001). Survival analysis showed a higher CLBR in the treatment group (adjusted hazard ratio [aHR] 1.78, 95% CI 1.62-1.94, p < .001).

CONCLUSION(S)

This study provides evidence of a potential beneficial effect of immunomodulation therapy in women with RIF after immunological testing. There remains a need for high quality, adequately powered multicentre RCTs to robustly address the role of immunomodulation in women with RIF. There is also an urgent need for standardised screening tests for immune disorders that could preclude implantation.

Prophylactic low-molecular-weight heparin in women with thrombophilia undergoing in vitro fertilization

OBJECTIVE

To verify whether low-molecular-weight heparin (LMWH) could increase pregnancy rates and/or decrease abortion rates in women with thrombophilia undergoing assisted reproduction cycles.

METHODS

Cross-sectional study with patients undergoing in vitro fertilization (IVF) (N = 104). Women without thrombophilia (control group, n = 20), women with thrombophilia who did not receive LMWH (untreated group, n = 30), and women with thrombophilia, treated with daily enoxaparin from the day of embryo transfer until week 36 of gestation (treated group, n = 54). All women underwent controlled ovarian hyperstimulation. IVF was performed by intracytoplasmic sperm injection, and embryos were transferred on day 3. Pregnancy was detected by β-human chorionic gonadotropin (biochemical pregnancy) and fetal heartbeat at week 5 to 6. Ongoing pregnancy was determined by ultrasound on week 12.

RESULTS

Patients in the untreated thrombophilia group presented with significantly lower ongoing pregnancy rates and live birth rates and significantly higher early pregnancy loss and abortion rates when compared with the control and the treated thrombophilia groups.

CONCLUSIONS

In women with diagnosed coagulation disorders, use of LMWH is important to avoid miscarriages.

Oleuropein Stimulates Migration of Human Trophoblast Cells and Expression of Invasion-Associated Markers

Successful pregnancy establishment requires highly synchronized cross talk between the invasive trophoblast cells and the receptive maternal endometrium. Any disturbances in this tightly regulated process may lead to pregnancy complications. Local factors such as nutrients, hormones, cytokines and reactive oxygen species modulate the invasion of extravillous trophoblasts through critical signaling cascades. Epidemiological studies strongly indicate that a Mediterranean diet can significantly impact molecular pathways during placentation. Therefore, the aim of the current study was to examine whether oleuropein (OLE), one of the main compounds of the Mediterranean diet, may influence trophoblast cell adhesion and migration, as well as the expression of invasion-associated molecular markers and inflammatory pathways fostering these processes. HTR-8/SVneo cells were incubated with OLE at selected concentrations of 10 and 100 µM for 24 h. Results showed that OLE did not affect trophoblast cell viability, proliferation and adhesion after 24 h in in vitro treatment. The mRNA expression of integrin subunits α1, α5 and β1, as well as matrix-degrading enzymes MMP-2 and -9, was significantly increased after treatment with 10 µM OLE. Furthermore, OLE at a concentration of 10 µM significantly increased the protein expression of integrin subunits α1 and β1. Also, OLE inhibited the activation of JNK and reduced the protein expression of COX-2. Finally, a lower concentration of OLE 10 µM significantly stimulated migration of HTR-8/SVneo cells. In conclusion, the obtained results demonstrate the effects of OLE on the function of trophoblast cells by promoting cell migration and stimulating the expression of invasion markers. As suggested from results, these effects may be mediated via inhibition of the JNK signaling pathway.

Cooperation between NSPc1 and DNA methylation represses HOXA11 expression and promotes apoptosis of trophoblast cells during preeclampsia

Accumulating evidence has shown that the apoptosis of trophoblast cells plays an important role in the pathogenesis of preeclampsia, and an intricate interplay between DNA methylation and polycomb group (PcG) protein-mediated gene silencing has been highlighted recently. Here, we provide evidence that the expression of nervous system polycomb 1 (NSPc1), a BMI1 homologous polycomb protein, is significantly elevated in trophoblast cells during preeclampsia, which accelerates trophoblast cell apoptosis. Since NSPc1 acts predominantly as a transcriptional inactivator that specifically represses HOXA11 expression in trophoblast cells during preeclampsia, we further show that NSPc1 is required for DNMT3a recruitment and maintenance of the DNA methylation in the HOXA11 promoter in trophoblast cells during preeclampsia. In addition, we find that the interplay of DNMT3a and NSPc1 represses the expression of HOXA11 and promotes trophoblast cell apoptosis. Taken together, these results indicate that the cooperation between NSPc1 and DNMT3a reduces HOXA11 expression in preeclampsia pathophysiology, which provides novel therapeutic approaches for targeted inhibition of trophoblast cell apoptosis during preeclampsia pathogenesis.

Low-molecular-weight heparin in addition to low-dose aspirin for preventing preeclampsia and its complications: A systematic review and meta-analysis

Background

In this systematic review, we aimed to investigate the efficacy and safety of adding low-molecular-weight heparin (LMWH) or unfractionated heparin to low-dose aspirin (LDA) started ≤16 weeks'gestation in the prevention of preeclampsia (PE) in high-risk women.

Methods

PubMed, Cochrane Library, Embase, and ClinicalTrials.gov databases were searched from their inception to April 2022 for randomized controlled trials (RCTs) that to determine whether the combined treatment of LMWH and LDA is better than single anticoagulant drugs in preventing PE and improving live birth rate of fetus in high-risk women with pregnancy ≤16 weeks. We also searched Embase, OVID MEDLINE and OVID MEDLINE in-process using the OVID platform.

Results

14 RCTs involving 1,966 women were found. The LMWH (or unfractionated heparin) and LDA groups included 1,165 wemen, and the LDA group included 960 women. The meta-analysis showed that the addition of LMWH to LDA reduced the risk of PE (RR: 0.59, 95% CI: 0.44-0.79, P < 0.05), small-for-gestational age (SGA, RR: 0.71, 95% CI: 0.52-0.97, P = 0.03), fetal and neonatal death (RR: 0.45, 95% CI: 0.23-0.88, P = 0.02) and gestational hypertension (RR: 0.47, 95% CI: 0.25-0.90, P = 0.02). It is worth emphasizing that LMWH (or unfractionated heparin) combined with LDA did not increase the risk of bleeding.

Conclusions

LMWH combined with LDA can effectively improve the pregnancy outcome of women with high risk factors for PE and its complications. Although this study showed that combined medication also did not increase the risk of bleeding, but such results lack the support of large sample size studies. The clinical safety analysis of LMWH combined with LDA in patients with PE should be more carried out.

Monitoring hypertensive disorders in pregnancy to prevent preeclampsia in pregnant women of advanced maternal age: Trial mimicking with retrospective data

This study investigated the implication of monitoring hypertensive disorders in pregnancy (HDP) to prevent preeclampsia (PE) in pregnant women of advanced maternal age. Between January 2016 and April 2021, 262 consecutive pregnant women aged ≥40 years were recruited. Extensive monitoring of hypertensive disorders in pregnancy, including blood hypercoagulability screening and subsequent interventions, was performed in 129 pregnant women in our university hospital. The remaining 133 patients from other centres, who did not receive antenatal maternal pregnancy screening and preventive intervention during the same period, constituted the non-intervention group enabling comparison to mimic a trial. The incidences of hypertensive disorders, mild and severe PE, eclampsia, and chronic hypertension complicated by PE in the intervention group were significantly lower than in the non-intervention group (10.08 versus 20.30%, 8.52 versus 18.80%, 7.75 versus 21.05%, 0 versus 3.01%, and 3.86 versus 15.04%, respectively; P < 0.05). Premature birth, low birth weight, and foetal loss were significantly rarer in the intervention group than in the non-intervention group (6.98 versus 24.81%, 7.75 versus 21.80%, and 0.78 versus 14.29% respectively; P < 0.001). The comparison of MP with routine blood coagulation biochemical examination found that the MP detection system of Beijing Yes Medical Devices Co., Ltd., had similar sensitivity as thromboelastogram. Still, it was significantly better than the routine biochemical indicators (P < 0.01). Based on MP parameters, early anticoagulant treatment with low-molecular-weight heparin or low-dose aspirin in pregnant women with hypercoagulability can effectively prevent the occurrence of PE and significantly improve the prognosis of both mothers and infants.

Emerging pharmacologic interventions for pre-eclampsia treatment

INTRODUCTION

Pre-eclampsia is a serious pregnancy complication and a major global concern for the mortality of both mother and fetus. Existing symptomatic treatments do not delay disease progression; thus, timely delivery of the baby is the most effective measure. However, the risk of various maternal and fetal injuries remains.

AREAS COVERED

In this review, we summarize the potential strategies for pharmacologic interventions in pre-eclamptic therapy. Specifically, we discuss the pathophysiological process of various effective candidate therapeutics that act on potential pathways and molecular targets to inhibit key stages of the disease. We refer to this pathogenesis-focused drug discovery model as a pathogenesis-target-drug (P-T-D) strategy. Finally, we discuss the introduction of nanotechnologies to improve the safety and efficacy of therapeutics via their specific placental targeting ability and placental retention effects.

EXPERT OPINION

Despite the active development of novel pharmacological treatments based on our current knowledge of pre-eclamptic pathogenesis, investigations are still in the early phase. Thus, further exploration of the pathological mechanisms, integrated with the P-T-D strategy and novel nanosystems, could encourage the development of more effective and safer strategies. Such advances could lead to a shift from expectant management to mechanistic-based therapy for pre-eclampsia.

Toxicity assessments of selected trichloroethylene and perchloroethylene metabolites in three in vitro human placental models

Residential and occupational exposures to the industrial solvents perchloroethylene (PERC) and trichloroethylene (TCE) present public health concerns. In humans, maternal PERC and TCE exposures can be associated with adverse birth outcomes. Because PERC and TCE are biotransformed to toxic metabolites and placental dysfunction can contribute to adverse birth outcomes, the present study compared the toxicity of key PERC and TCE metabolites in three in vitro human placenta models. We measured cell viability and caspase 3 + 7 activity in the HTR-8/SVneo and BeWo cell lines, and caspase 3 + 7 activity in first trimester villous explant cultures. Cultures were exposed for 24 h to 5-100 µM S-(1,2-dichlorovinyl)-L-cysteine (DCVC) and S-(1,2,2-trichlorovinyl)-L-cysteine (TCVC), or 5-200 µM trichloroacetate (TCA) and dichloroacetate (DCA). DCVC significantly reduced cell viability and increased caspase 3 + 7 activity in HTR-8/SVneo cells at a lower concentration (20 µM) compared with concentrations toxic to BeWo cells and villous explants. Similarly, TCVC reduced cell viability and increased caspase 3 + 7 activity in HTR-8/SVneo cells but not in BeWo cells. TCA and DCA had only negligible effects on HTR-8/SVneo or BeWo cells. This study advances understanding of potential risks of PERC and TCE exposure during pregnancy by identifying metabolites toxic in placental cells and tissues.

The Ontogeny and Function of Placental Macrophages

The placenta is a fetal-derived organ whose function is crucial for both maternal and fetal health. The human placenta contains a population of fetal macrophages termed Hofbauer cells. These macrophages play diverse roles, aiding in placental development, function and defence. The outer layer of the human placenta is formed by syncytiotrophoblast cells, that fuse to form the syncytium. Adhered to the syncytium at sites of damage, on the maternal side of the placenta, is a population of macrophages termed placenta associated maternal macrophages (PAMM1a). Here we discuss recent developments that have led to renewed insight into our understanding of the ontogeny, phenotype and function of placental macrophages. Finally, we discuss how the application of new technologies within placental research are helping us to further understand these cells.

Efficacy of Low Molecular Heparin on Preeclampsia by Inhibiting Apoptosis of Trophoblasts via the p38MAPK Signaling Pathway

OBJECTIVE

To explore the efficacy of low molecular heparin on preeclampsia by inhibiting apoptosis of trophoblasts via the p38MAPK signaling pathway.

METHODS

A preeclampsia rat model was established, and the effects of low molecular heparin on preeclampsia via the p38MAPK signaling pathway were analyzed based on intervention of the rats with different combinations of low molecular heparin and p38MAPK signaling pathway activator. Furthermore, a hypoxia/reoxygenation model of trophoblasts in vitro was established to explore the effects of low molecular heparin on trophoblasts via the p38MAPK signaling pathway.

RESULTS

After treatment with low molecular heparin, pregnant rats in the heparin group showed significantly decreased blood pressure, 24 h proteinuria, and p38MAPK protein levels in placenta tissues and decreased apoptosis rate of placenta tissue cells (all P < 0.05) and showed more fetal rats and lowered weight of them (both P < 0.05) but showed no significant change in the weight of placenta (all P > 0.05). Pregnant rats treated with low molecular heparin and p38MAPK activator showed significantly higher blood pressure, 24 h proteinuria, and p38MAPK protein levels in placenta tissues and apoptosis rate of placenta tissue cells than those of pregnant rats in the heparin group (all P < 0.05) and also showed less fetal rats and lighter fetal rats than those in the heparin group (both P < 0.05) but showed no difference with them in the weight of placenta (P > 0.05). Further analysis revealed that low molecular heparin could protect the survival and migration of trophoblasts under hypoxia/reoxygenation conditions and reduce apoptosis of them (all P < 0.05).

CONCLUSION

Low molecular heparin can alleviate preeclampsia by inhibiting the p38MAPK signaling pathway and can inhibit apoptosis of trophoblasts and promote proliferation and migration of them.

Transcriptional profiling of the response to the trichloroethylene metabolite S-(1,2-dichlorovinyl)-L-cysteine revealed activation of the eIF2α/ATF4 integrated stress response in two in vitro placental models

Trichloroethylene (TCE) is an industrial solvent and widespread environmental contaminant. Although TCE exposure is prevalent, epidemiological studies of TCE exposure associations with adverse birth outcomes are inconclusive. Prior studies show that the TCE metabolite S-(1,2-dichlorovinyl)-l-cysteine (DCVC) exhibits toxicity in a placental cell line. In the current study, genome-wide gene expression and gene set enrichment analyses were used to identify novel genes and pathway alterations in the HTR-8/SVneo human trophoblast cell line and human placental villous explants treated with DCVC at concentrations relevant to human exposures. In the cells, concentration- and time-dependent effects were observed, as evidenced by the magnitude of altered gene expression after treatment with 20 µM DCVC versus 10 µM, and 12-h versus 6-h of treatment. Comparing the two models for the transcriptional response to 12-h 20 µM DCVC treatment, no differentially expressed genes reached significance in villous explants, whereas 301 differentially expressed genes were detected in HTR-8/SVneo cells compared with non-treated controls (FDR < 0.05 + LogFC > 0.35 [FC > 1.3]). GSEA revealed five upregulated enriched pathways in common between explants and cells (FDR < 0.05). Moreover, all 12-h DCVC treatment groups from both models contained upregulated pathways enriched for genes regulated by the ATF4 transcription factor. The overrepresentation of ATF4 regulation of differentially expressed genes indicated activation of the integrated stress response (ISR), a condition triggered by multiple stress stimuli, including the unfolded protein response. DCVC-induced ISR activation was confirmed by elevated eIF2α phosphorylation, ATF4 protein concentrations, and decreased global protein synthesis in HTR-8/SVneo cells. This study identifies a mechanism of DCVC-induced cytotoxicity by revealing the involvement of a specific stress signaling pathway.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

Palmitic acid induces inflammation in placental trophoblasts and impairs their migration toward smooth muscle cells through plasminogen activator inhibitor-1

A critical component of early human placental development includes migration of extravillous trophoblasts (EVTs) into the decidua. EVTs migrate toward and displace vascular smooth muscle cells (SMCs) surrounding several uterine structures, including spiral arteries. Shallow trophoblast invasion features in several pregnancy complications including preeclampsia. Maternal obesity is a risk factor for placental dysfunction, suggesting that factors within an obese environment may impair early placental development. Herein, we tested the hypothesis that palmitic acid, a saturated fatty acid circulating at high levels in obese women, induces an inflammatory response in EVTs that hinders their capacity to migrate toward SMCs. We found that SMCs and SMC-conditioned media stimulated migration and invasion of an EVT-like cell line, HTR8/SVneo. Palmitic acid impaired EVT migration and invasion toward SMCs, and induced expression of several vasoactive and inflammatory mediators in EVTs, including endothelin, interleukin (IL)-6, IL-8 and PAI1. PAI1 was increased in plasma of women with early-onset preeclampsia, and PAI1-deficient EVTs were protected from the anti-migratory effects of palmitic acid. Using first trimester placental explants, palmitic acid exposure decreased EVT invasion through Matrigel. Our findings reveal that palmitic acid induces an inflammatory response in EVTs and attenuates their migration through a mechanism involving PAI1. High levels of palmitic acid in pathophysiological situations like obesity may impair early placental development and predispose to placental dysfunction.

Adjuvants in IVF-evidence for what works and what does not work

The field of assisted reproductive technology is shaped and changed constantly by advances in science and cutting-edge innovations. In a quest to maximise outcomes, add-on interventions are often adopted and utilised prematurely while the principles of evidence-based medicine seem to be less strictly adhered to. In this review we will attempt to summarise the latest evidence about some of the adjuvants.

Irisin induces trophoblast differentiation via AMPK activation in the human placenta

Irisin, an adipokine, regulates differentiation and phenotype in various cell types including myocytes, adipocytes, and osteoblasts. Circulating irisin concentration increases throughout human pregnancy. In pregnancy disorders such as preeclampsia and gestational diabetes mellitus, circulating irisin levels are reduced compared to healthy controls. To date, there are no data on the role and molecular function of irisin in the human placenta or its contribution to pathophysiology. Aberrant trophoblast differentiation is involved in the pathophysiology of preeclampsia. The current study aimed to assess the molecular effects of irisin on trophoblast differentiation and function. First-trimester placental explants were cultured and treated with low (10 nM) and high (50 nM) physiological doses of irisin. Treatment with irisin dose-dependently increased both in vitro placental outgrowth (on Matrigel™) and trophoblast cell-cell fusion. Adenosine monophosphate-activated protein kinase (AMPK) signaling, an important regulator of cellular energy homeostasis that is involved in trophoblast differentiation and pathology, was subsequently investigated. Here, irisin exposure induced placental AMPK activation. To determine the effects of irisin on trophoblast differentiation, two trophoblast-like cell lines, HTR-8/SVneo and BeWo, were treated with irisin and/or a specific AMPK inhibitor (Compound C). Irisin-induced AMPK phosphorylation in HTR-8/SVneo cells. Additionally, as part of the differentiation process, integrin switching from α6 to α1 occurred as well as increased invasiveness. Overall, irisin promoted differentiation in villous and extravillous cell-based models via AMPK pathway activation. These findings provide evidence that exposure to irisin promotes differentiation and improves trophoblast functions in the human placenta that are affected in abnormal placentation.

Upregulated ARRDC3 limits trophoblast cell invasion and tube formation and is associated with preeclampsia

OBJECTIVE

Bioinformatics analysis indicated that the arrestin ARRDC3 was upregulated in placental tissue from patients with preeclampsia (PE). The study aimed to confirm the finding by examining placenta samples from women with and without early-onset PE and to investigate ARRDC3 roles in trophoblast function.

METHODS

ARRDC3 expression level and localization in placental tissue were determined by Western blot, real-time quantitative PCR and immunohistochemistry. An in vitro hypoxia and an in vitro ischemia (hypoxia/reoxygenation) cell models were used to determine the hypoxic and ischemic effects on ARRDC3 expression in extravillous trophoblast-derived HTR/8SVneo cells and trophoblast cell activity. The role of ARRDC3 in HTR8/SVneo cell proliferation, invasion and tube formation in vitro was investigated by testing the effects of ARRDC3 gene overexpression or siRNA-based gene silencing.

RESULTS

ARRDC3 expression was significantly elevated in placental tissue from women with early-onset PE compared to preterm birth pregnancies. ARRDC3 protein was localized in human placental trophoblasts. Hypoxia and ischemia both enhanced ARRDC3 protein expression in HTR8/SVneo cells. Hypoxia altered trophoblast cell activities. Overexpression of ARRDC3 in HTR8/SVneo cells suppressed cell invasion and tube formation. ARRDC3 gene silencing, by contrast, promoted invasion and tube formation under hypoxic conditions.

CONCLUSION

ARRDC3 was highly expressed in placental tissues of PE patients and directly affected biological activities of trophoblasts under hypoxic conditions. In regulation of ARRDC3- protein expression, ischemia (hypoxia/reoxygenation) are also important. These findings suggest that ARRDC3 may play a clinically significant role in the pathogenesis of PE.

Effects of glycol-split low molecular weight heparin on placental, endothelial, and anti-inflammatory pathways relevant to preeclampsia

Low molecular weight heparin (LMWH) is being investigated as a potential preventative therapy against preeclampsia. There is evidence suggesting that LMWH may prevent preeclampsia through anticoagulation-independent mechanisms. In this study, we compared the in vitro placental, endothelial, and anti-inflammatory effects of an LMWH (dalteparin) with a nonanticoagulant, glycol-split heparin derivative (gsHep). In contrast with dalteparin, gsHep did not interact with antithrombin III, possess significant anti-Factor Xa activity, or significantly prolong in vitro plasma clotting time. However, dalteparin and gsHep were otherwise mechanistically similar, both interacting with soluble fms-like tyrosine kinase-1 (sFlt1) and promoting release of the pro-angiogenic protein placental growth factor, but not the antiangiogenic sFlt1, from healthy placental villous explants. Placental explant media pretreated with dalteparin or gsHep significantly stimulated endothelial cell tube formation compared to untreated explants. Lastly, dalteparin and gsHep both significantly suppressed inflammation by inhibiting complement activation and leukocyte adhesion to endothelial cells that were activated using serum from preeclamptic women. Our data suggest that nonanticoagulant heparin derivatives may be utilized as a tool to distinguish the anticoagulation-independent mechanisms of LMWH, and provide insight into the role of anticoagulation in the prevention of preeclampsia.

Paracrine action of human placental trophoblast cells attenuates cisplatin-induced acute kidney injury

AIMS

The action of cell-based therapy against acute kidney injury (AKI) has been demonstrated by different groups for years. However, which kind of cells hold best therapeutic effect remains unclear. In this study, we mainly explored whether human placental trophoblast cells hold the potential to be applied in AKI therapy.

MAIN METHODS

To study the renoprotective effect, the trophoblast cells were isolated from human placenta and characterized by flow cytometry first. The AKI model was induced using cisplatin in NOD-SCID mice. The therapeutic effect of human placental trophoblast cells on renal function, apoptosis and inflammation were analyzed respectively.

KEY FINDINGS

The administration of trophoblast cells isolated from human placenta improved the pathological changes of kidney tissues and renal dysfunction induced by cisplatin. In addition, the placental trophoblast cell-based treatment also showed anti-apoptotic effect and decreased the level of apoptotic genes (Bax and Caspase 3) expression in damaged kidney tissues obviously. All of the inflammatory components (MCP-1, IL-10 and RANTES) in kidney tissues were down-regulated with the therapy of placental trophoblast cells. Further analysis indicated that the paracrine effects of human placental trophoblast cells may hold a key position in the AKI therapy process.

SIGNIFICANCE

In this study, we mainly developed a novel therapeutic strategy to treat cisplatin-induced AKI with human placental trophoblast cells. Even though the detailed mechanism and the optimizations of this cell-based therapy still need further investigation, the application of placental trophoblast cell holds special potential in the treatment of patients with AKI.

Molecular actions of heparin and their implications in preventing pre-eclampsia

Pre-eclampsia, a hypertensive disorder of pregnancy, continues to be a significant cause of global maternal morbidity. Low-dose aspirin remains the only standard-of-care prophylactic therapy for preventing pre-eclampsia, but is limited in efficacy. Heparin and its derivatives may further enhance the efficacy of aspirin therapy to prevent pre-eclampsia, but the mechanisms mediating this augmentative effect are not known. Although heparin is an anticoagulant agent, it also possesses many anticoagulant-independent properties that may be relevant in the prevention of pre-eclampsia, including effects on placental, vascular and inflammatory function. This review summarizes the non-anticoagulant properties of heparin, and extrapolates how these actions may influence the trajectory of pre-eclampsia pathogenesis as a means of pathway-specific therapy.

Oxidative Stress in Preeclampsia and Placental Diseases

Preeclampsia is a persistent hypertensive gestational disease characterized by high blood pressure and proteinuria, which presents from the second trimester of pregnancy. At the cellular level, preeclampsia has largely been associated with the release of free radicals by the placenta. Placenta-borne oxidative and nitrosative stresses are even sometimes considered as the major molecular determinants of the maternal disease. In this review, we present the recent literature evaluating free radical production in both normal and pathological placentas (including preeclampsia and other major pregnancy diseases), in humans and animal models. We then assess the putative effects of these free radicals on the placenta and maternal endothelium. This analysis was conducted with regard to recent papers and possible therapeutic avenues.