The regulation of apoptosis in intrauterine growth restriction: a study ofBcl-2andBaxgene expression in human placenta

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.

Sexual dimorphism in placental development and function: Comparative physiology with an emphasis on the pig

Across mammalian species, it has been demonstrated that sex influences birth weight, with males being heavier than females; a characteristic that can be observed from early gestation. Male piglets are more likely to be stillborn and have greater preweaning mortality than their female littermates, despite the additional maternal investment into male fetal growth. Given the conserved nature of the genome between the sexes, it is hypothesized that these developmental differences between males and females are most likely orchestrated by differential placental adaptation. This review summarizes the current understanding of fetal sex-specific differences in placental and endometrial structure and function, with an emphasis on pathways found to be differentially regulated in the pig including angiogenesis, apoptosis, and proliferation. Given the importance of piglet sex in agricultural enterprises, and the potential for skewed litter sex ratios, it is imperative to improve understanding of the relationship between fetal sex and molecular signaling in both the placenta and endometria across gestation.

The role of apoptosis in the complex pathogenesis of the most common obstetrics and gynaecology diseases

Purpose

We aimed to assess the etiological role of apoptotic genes Bcl-2 and Bax in the background of major obstetric and gynaecological diseases.

Methods

Placental tissue samples were collected from 101 pregnancies with intrauterine growth restriction and 104 pregnancies with premature birth with 140 controll samples from term, eutrophic newborns. In addition, gene expression assessment of the genes Bax and Bcl-2 was performed in 101 uterine leiomyoma tissue samples at our disposal with 110 control cases. Gene expression levels were assessed by PCR method.

Results

The expression of the Bcl-2 gene was decreased in placental samples with intrauterine growth restriction. Significant overexpression of the proapoptotic Bax gene was detected in samples from premature infants. Antiapoptotic Bcl-2 gene expression was found to be significantly increased in fibroid tissues.

Conclusion

Apoptosis plays a crucial role in the development of the most common OB/GYN conditions. Decrease in the placental expression of the antiapoptotic gene Bcl-2 may upset the balance of programmed cell death.

Evaluation of Apoptosis, Proliferation, and Adhesion Molecule Expression in Trophoblastic Tissue of Women With Recurrent Spontaneous Abortion and Infected With Toxoplasma gondii

Recurrent spontaneous abortion is an obstetric complication with undefined causes. Apoptosis, proliferation, and adhesion are considered important factors in the pathogenesis of abortion. This work aimed to determine Bax and Bcl-2 as a proapoptotic and antiapoptotic protein, Ki67 and P27kip as proliferative and antiproliferative proteins, and E-cadherin and CD44 as adhesion molecules in the trophoblastic tissues in cases with recurrent miscarriage. Immunohistochemistry and quantitative polymerase chain reaction analysis of Bax, Bcl-2, Ki67, P27kip, E-cadherin, and CD44 in paraffin-embedded sections of placental tissues obtained from 108 women were divided into 3 categories: 66 Toxoplasma gondii-positive women with recurrent abortion, 22 T. gondii-negative women with recurrent abortion, and 20 women with no history of abortion as a control group. The mean ratio of the expression of Bax and P27kip proteins was 35.3% and 36.1%, which is significantly higher than that of the second group (19.88 and 20.02%), and the third group (12.3% and 10.98%), while the mean ratio of the expression of Bcl-2, Ki67, E-cadherin, and CD44 proteins was 12.35%, 11.23%, 10.32%, and 9.97%, which is significantly lower than that of the second group (33.75%, 13.18%, 21.88%, and 23.29%) and that of the third group (38.58%, 39.27%, 37.98%, and 35.79%). The presence of proapoptotic protein (Bax) and antiproliferative protein (P27kip) at high levels and the presence of antiapoptotic protein (Bcl-2), proliferative protein (Ki67), and adhesion molecules (E-cadherin and CD44) in lower levels in the T. gondii-positive group clarify the mechanism involved in the induction of abortion and loss of pregnancy.

In vitro fertilization and embryo transfer alter human placental function through trophoblasts in early pregnancy

The mechanism underlying the potential risk associated with in vitro fertilization and embryo transfer (IVF‑ET) has been previously investigated but remains to be fully elucidated. As the placenta is a critical organ that sustains and protects the fetus, this is an important area of research. The aim of the present study was to determine the difference in trophoblast cell function in the first trimester between naturally conceived pregnancies and pregnancies achieved via IVF‑ET therapy. A total of 20 placental villi in first trimester samples were obtained through fetal bud aspiration from patients undergoing IVF‑ET due to oviductal factors between January 2016 and August 2018. In addition, a further 20 placental villi were obtained from those who naturally conceived and had normal pregnancies but were undergoing artificial abortion; these patients were recruited as the controls. Reverse transcription‑quantitative (RT‑q)PCR and semi‑quantitative immunohistochemical methods were used to detect the mRNA and protein expression of α‑fetoprotein (AFP), vascular endothelial growth factor (VEGF), transferrin (TF), tubulin β1 class VI (TUBB1), metallothionein 1G (MT1G), BCL2, glial cells missing transcription factor 1 (GCM1), epidermal growth factor (EGF) receptor (EGFR), PTEN and leukocyte associated immunoglobulin like receptor 2 (LAIR2) in villi from both groups. Differentially expressed genes were analyzed using Search Tool for the Retrieval of Interacting Genes, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted. The RT‑qPCR data revealed that the mRNA expression levels of AFP, VEGF and TF were significantly higher in the IVF‑ET group than in the control group (P<0.05), and those of TUBB1, MT1G, BCL2, GCM1, EGFR, PTEN and LAIR2 were significantly lower (P<0.05). These gene products were expressed in the placental villus tissues, either in the cytoplasm, or in the membrane of syncytiotrophoblast and cytotrophoblast cells. The immunohistochemistry results were in line with those observed using RT‑qPCR. KEGG pathway analysis indicated that the trophoblast cell function of the IVF‑ET group in the first trimester was different from naturally conceived pregnancies with regard to proliferation, invasion, apoptosis and vascular development. The IVF‑ET process may trigger adaptive placental responses, and these compensatory mechanisms could be a risk for certain diseases later in life.

Synthetic cannabinoids JWH-018, JWH-122, UR-144 and the phytocannabinoid THC activate apoptosis in placental cells

The increasing use of synthetic cannabinoids (SCBs) in recreational settings is becoming a new paradigm of drug abuse. Although SCBs effects mimic those of the Cannabis sativa plant, these drugs are frequently more potent and hazardous. It is known that endocannabinoid signalling plays a crucial role in diverse reproductive events such as placental development. Moreover, the negative impact of the phytocannabinoid Δ⁹-tetrahydrocannabinol (THC) in pregnancy outcome, leading to prematurity, intrauterine growth restriction and low birth weight is well recognized, which makes women of childbearing age a sensitive group to developmental adverse effects of cannabinoids. Placental trophoblast turnover relies on regulated processes of proliferation and apoptosis for normal placental development. Here, we explored the impact of the SCBs JWH-018, JWH-122 and UR-144 and of the phytocannabinoid THC in BeWo cell line, a human placental cytotrophoblast cell model. All the cannabinoids caused a significant decrease in cell viability without LDH release, though this effect was only detected for the highest concentrations of THC. Moreover, a cell cycle arrest at the G₂/M phase was also observed. JWH-018 and JWH-122 increased reactive oxygen species (ROS) production and THC, UR-144 and JWH-122 caused loss of mitochondrial membrane potential. All the compounds were able to induce caspase-9 activation. The involvement of apoptotic pathways was further confirmed through the significant increase in caspase -3/-7 activities. For UR-144, this effect was reversed by the CB1 antagonist AM281, for JWH-018 and THC this effect was mediated by both cannabinoid receptors CB1 and CB2 while for JWH-122 it was cannabinoid receptor-independent. This work demonstrates that THC and SCBs are able to induce apoptotic cell death. Although they may act through different mechanisms and potencies, the studied cannabinoids have the potential to disrupt gestational fundamental events.

SCM-198 protects endometrial stromal cells from oxidative damage through Bax/Bcl-2 and ERK signaling pathways

Increasing amounts of evidence demonstrated that accumulative reactive oxygen species (ROS) and apoptosis of human endometrial stromal cells (ESCs) are closely associated with endometrial dysfunction induced by oxidative stress, which plays an important role in the pathological process of multiple gynecological and reproduction-related diseases. SCM-198, an alkaloid active component of Leonurus japonicas Houtt, has been reported to have anti-oxidative activity. However, the specific mechanisms of SCM-198 in the prevention of endometrial damage remain unknown. In the present study, we assessed the effect of SCM-198 on hydrogen peroxide (H2O2)-induced oxidative injury in ESCs. ESCs were pretreated with SCM-198 for 4 h and then challenged with H2O2. Morphology changes, apoptosis rate, and intracellular ROS production were measured to assess the level of oxidative injury. Flow cytometry and western blot analysis were performed to detect the expression levels of Bax, Bcl-2, active-caspase-3, and mitogen-activated protein kinases pathways. Classic inflammation cytokines were measured by real-time polymerase chain reactions. Our results showed that SCM-198 attenuated apoptosis and ROS generation of ESCs induced by H2O2. H2O2 induced the apparent apoptotic characteristics, including fragmentation of DNA, upregulation of Bax/Bcl2, activation of caspase-3, and secretion of inflammation cytokines, which were all ameliorated by SCM-198. Furthermore, H2O2-induced apoptosis-related ERK1/2 pathway activation was restrained by SCM-198 pretreatment. These findings suggested that SCM-198 could protect ESCs from oxidative injury, mainly by inhibiting oxidative stress and reducing apoptosis.

Effects of lentivirus-mediated astrocyte elevated gene-1 overexpression on proliferation and apoptosis of human retinoblastoma cells

PURPOSE

To investigate the effect of astrocyte elevated gene-1 (AEG-1) overexpression on the biological behaviour of human retinoblastoma (RB) cells and its possible mechanism.

METHODS

Three human RB cell lines (SO-RB50, Y79 and WERI-RB1) were infected with AEG-1-GFP recombinant lentiviral vectors to induce AEG-1 overexpression, while the cells infected with negative lentiviral vectors and cells without any intervention formed control groups.

RESULTS

All three RB cell lines showed an overexpression of AEG-1 after lentivirus infection (p < 0.001 for all three cell lines). The survival rate of RB cells increased (all p < 0.001) in the AEG-1 overexpressed groups when compared with the control groups. There was a decrease in G0/G1 cell cycle phase arrest and an accumulation in G2/M cell cycle phase in all three RB cell lines (p < 0.001), with an induction in the S phase in WERI-RB1 cells. It was paralleled by a downregulation of p21 and p27 proteins and an upregulation of the Cdc2 protein. The apoptosis rate of RB cells declined (p < 0.001) when AEG-1 was overexpressed, in association with an upregulation of Bcl-2 protein and a downregulation of Bax protein and cleaved caspase-3 proteins.

CONCLUSIONS

A lentivirus-mediated AEG-1 overexpression in RB cells led in vitro to a growth promotion and an apoptosis inhibition of human RB cells, associated with an upregulation of the Bcl-2 protein, a downregulation of the Bax protein and of cleaved caspase-3 proteins, and with alterations of the cell cycle. AEG-1 may be involved in the development and progression of RB.

LncRNA-MEG3 alleviates high glucose induced inflammation and apoptosis of retina epithelial cells via regulating miR-34a/SIRT1 axis

BACKGROUND

Diabetic retinopathy (DR) is the serious complication of diabetes, which could lead to blindness. Inflammation and apoptosis are hallmark of DR, but mechanism of their regulation is little known. LncRNA-MEG3 is associated with multiple biological processes including proliferation, apoptosis and inflammation response, and is dramatically decreased in DR. However, the role and underlying mechanism of MEG3 in DR is unclear. This study is aimed to reveal the signaling mechanisms of MEG3 in inflammation and apoptosis of DR.

METHODS

ARPE-19 cells were applied for this research. MEG3 was cloned into pcDNA3.1. miR-34a was overexpressed and inhibited by transfecting with mimics and inhibitor, respectively. The expression level was detected by qRT-PCR and western blotting. The targeted regulatory relationship was analyzed by dual luciferase assay. Cytokine secretion, cell viability and apoptosis were detected by ELISA assay, MTT assay and flow cytometry analysis, respectively.

RESULTS

High glucose (HG) inhibited MEG3 and SIRT1 expression and enhanced miR-34a expression. MEG3 could promote SIRT1 expression by targeting miR-34a. MEG3 overexpression and miR-34a knockdown could inhibit HG-induced apoptosis and secretion of inflammation cytokines including IL-1β, IL-6 and TNF-α, but miR-34a overexpression alleviated such effects of MEG3. Furthermore, MEG3 overexpression also inhibited NF-κB signaling pathway and increased Bcl-2/Bax ratio via down-regulating miR-34a.

CONCLUSION

MEG3 could alleviate HG-inducing apoptosis and inflammation via inhibiting NF-κB signaling pathway by targeting miR-34a/SIRT1 axis. This finding illustrated the function and mechanism of MEG3 in DR, and MEG3 might serve as potential therapeutic target for DR.

Children Born Small for Gestational Age: Differential Diagnosis, Molecular Genetic Evaluation, and Implications

Children born small for gestational age (SGA), defined as a birth weight and/or length below -2 SD score (SDS), comprise a heterogeneous group. The causes of SGA are multifactorial and include maternal lifestyle and obstetric factors, placental dysfunction, and numerous fetal (epi)genetic abnormalities. Short-term consequences of SGA include increased risks of hypothermia, polycythemia, and hypoglycemia. Although most SGA infants show catch-up growth by 2 years of age, ∼10% remain short. Short children born SGA are amenable to GH treatment, which increases their adult height by on average 1.25 SD. Add-on treatment with a gonadotropin-releasing hormone agonist may be considered in early pubertal children with an expected adult height below -2.5 SDS. A small birth size increases the risk of later neurodevelopmental problems and cardiometabolic diseases. GH treatment does not pose an additional risk.

Associations between fetal size, sex and both proliferation and apoptosis at the porcine feto-maternal interface

Introduction

Inadequate fetal growth has severe consequences for both neonatal and adult development. It is hypothesised that the feto-maternal interface associated with the lightest and male fetuses will undergo more apoptosis and less proliferation than those supplying the closest to mean litter weight (CTMLW) and female fetuses respectively.

Methods

Placental and endometrial samples associated with the lightest and CTMLW (gestational day (GD) 18 and 30), male and female (GD45, 60 and 90) Large White X Landrace conceptuses or fetuses were obtained. The mRNA expression of candidate genes involved in apoptosis or proliferation (BAX, BCL2, P53 and KI67) was quantified by qPCR. TUNEL staining was performed on placental samples supplying the lightest and CTMLW fetuses (GD45 and 60), of both sex (GD60).

Results

Placentas associated with the lightest fetuses had decreased P53 and KI67 expression compared to the CTMLW fetuses at GD45. At GD60, P53 expression was increased in placentas supplying the lightest compared to CTMLW fetuses. P53 expression was increased in endometrial samples associated with the lightest compared to the CTMLW fetuses at GD45. At GD30 and GD60 respectively, BAX expression was increased and BCL2, P53 and KI67 expression were decreased in endometrial samples associated with females compared to their male littermates. TUNEL staining revealed no association between fetal size or sex, and apoptotic cell number.

Discussion

This study has highlighted dynamic associations between fetal size, sex, and apoptosis and proliferation at the porcine feto-maternal interface. Further studies should be performed to improve the understanding of the mechanisms behind these findings.

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Gestational day influence feto-maternal interface apoptotic mRNA expression.

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Fetal size is associated with feto-maternal interface apoptotic mRNA expression.

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Sexual dimorphism exists in feto-maternal interface apoptotic mRNA expression.

The endocannabinoid system: A novel player in human placentation

Cannabis sativa is the most consumed illegal drug around the world. Its consumption during pregnancy is associated with gestational complications, particularly with fetal growth restriction. Endocannabinoids (eCBs) are lipid molecules that act by activating the G-protein coupled cannabinoid receptors, which are also target of the phytocannabinoid Δ(9)-tetrahydrocannabinol (THC). The endocannabinoid system (ECS) participates in distinct biological processes, including pain, inflammation, neuroprotection, and several reproductive events. In addition, an abnormal expression of ECS is associated with infertility and miscarriages. This manuscript will review and discuss the expression of ECS in normal and pathological human placentas, and the role of eCBs and THC in trophoblast proliferation, apoptosis, differentiation, and function. The current evidence points towards a role of ECS in human placentation, shedding light on the contribution of the eCBs in the coordination of human placentation, and in the cellular mechanisms underlying the deleterious effects of cannabis consumption during pregnancy.

Intrauterine growth restriction - part 1

Intrauterine growth restriction (IUGR) is a major and silent cause of various morbidity and mortality for the fetal and neonatal population. It is defined as a rate of fetal growth that is less than normal for the growth potential of that specific infant. The terms IUGR and small for gestational age (SGA) are often used interchangeably, although there exists subtle differences between the two. IUGR/SGA is an end result of various etiologies that includes maternal, placental and fetal factors and recently added genetic factors too, also contribute to IUGR. In this review article we will cover the antenatal aspect of IUGR and management with proven preventive intervention.

Intraplacental gene therapy with Ad-IGF-1 corrects naturally occurring rabbit model of intrauterine growth restriction

Intrauterine growth restriction (IUGR) due to placental insufficiency is a leading cause of perinatal complications for which there is no effective prenatal therapy. We have previously demonstrated that intraplacental injection of adenovirus-mediated insulin-like growth factor-1 (Ad-IGF-1) corrects fetal weight in a murine IUGR model induced by mesenteric uterine artery branch ligation. This study investigated the effect of intraplacental Ad-IGF-1 gene therapy in a rabbit model of naturally occurring IUGR (runt) due to placental insufficiency, which is similar to the human IUGR condition with onset in the early third trimester, brain sparing, and a reduction in liver weight. Laparotomy was performed on New Zealand White rabbits on day 21 of 30 days of gestation and litters were divided into five groups: Control (first position)+phosphate-buffered saline (PBS), control+Ad-IGF-1, runt (third position)+PBS, runt+Ad-IGF-1, and runt+Ad-LacZ. The effect of IGF-1 gene therapy on fetal, placental, liver, heart, lung, and musculoskeletal weights of the growth-restricted pups was examined. Protein expression after gene transfer was seen along the maternal-fetal placenta interface (n=12) 48 hr after gene therapy. There was minimal gene transfer detected in the pups or maternal organs. At term, compared with the normally grown first-position control, the runted third-position pups demonstrated significantly lower fetal, placental, liver, lung, and musculoskeletal weights. The fetal, liver, and musculoskeletal weights were restored to normal by intraplacental Ad-IGF-1 gene therapy (p<0.01), with no change in the placental weight. Intraplacental gene therapy is a novel strategy for the treatment of IUGR caused by placental insufficiency that takes advantage of an organ that will be discarded at birth. Development of nonviral IGF-1 gene delivery using placenta-specific promoters can potentially minimize toxicity to the mother and fetus and facilitate clinical translation of this novel therapy.

The role of apoptosis in human embryo implantation

The process of embryo attachment and invasion through the endometrial epithelial cells and subsequent implantation into the decidualized endometrial stroma is the groundbreaking step for the establishment of a successful pregnancy. Necessary prerequisites are a receptive endometrium, a good-quality embryo and a well-orchestrated molecular dialog between embryo and maternal endometrium. The embryo-maternal dialog is conducted via a wide scope of factors, including secreted cytokines, chemokines, and growth factors in addition to the expression of corresponding receptors and co-receptors. Several embryonic proteins, including the aforementioned, are involved in the process of apoptosis, which necessarily needs to take place at the maternal endometrium to allow the embryo to invade. The endometrial epithelium is thereby disintegrated completely within a particular area, whereas the endometrial stroma seems to require a more depth-limited apoptosis. As of today, the exact mechanisms and factors mediating the apoptotic process involved in those apparently differently regulated incidents are not fully understood, particularly with regard to stromal cell apoptosis. There is evidence though, that cytokines and their respective receptors play a major role. A suggested important co-receptor for cytokines, which is highly upregulated in the receptive human endometrium, is the heparan sulfate proteoglycan syndecan-1. It is present on the cell surface and involved in the regulation of cell-cell-interaction, cell binding, cell signaling and cytoskeletal organization and therefore represents a possible mediator of apoptosis regulation in human endometrium. Herein, the literature on endometrial epithelial and stromal apoptosis in general, and in light of the influence of syndecan-1, is reviewed.

UNDERSTANDING THE PLACENTAL AETIOLOGY OF FETAL GROWTH RESTRICTION; COULD THIS LEAD TO PERSONALIZED MANAGEMENT STRATEGIES?

Fetal growth restriction (FGR) is defined as the failure of a fetus to attain its full genetic growth potential. It is a leading cause of stillbirth, prematurity, cerebral palsy and perinatal mortality. Small size at birth increases surviving infants’ lifelong risk of adverse health outcomes associated with the metabolic syndrome. The pathophysiology of abnormal fetal growth is extremely complex and incompletely understood, with a plethora of genetic, signalling and metabolic candidates under investigation, many of which may result in abnormal structure and function of the placenta. In contrast to, or maybe because of, the underlying complexities of FGR, the strategies clinicians have for identifying and managing this outcome are conspicuously limited. Current clinical practice is restricted to identifying pregnancies at risk of FGR, and when FGR is detected, using intensive monitoring to guide the timing of delivery to optimise fetal outcomes. Abnormal Doppler indices in the umbilical artery are strongly associated with poor perinatal outcomes and are currently the “gold standard” for clinical surveillance of the growth-restricted fetus.

The endocannabinoid anandamide induces apoptosis in cytotrophoblast cells: involvement of both mitochondrial and death receptor pathways

INTRODUCTION

A balanced proliferation, apoptosis and differentiation in trophoblast cells of the human placenta is crucial for a proper placental development. Alteration in trophoblast apoptosis and differentiation are associated with gestational-related complications, such as preeclampsia, intrauterine growth restriction or miscarriages. The endocannabinoids (eCBs) have been recognized as new interveners in pregnancy events such as implantation and decidualization. However, their importance in placentation is poorly understood. We hypothesise that these novel lipid mediators may intervene in cytotrophoblast apoptosis and, concomitantly, have a role during placental development.

METHODS

primary human cytotrophoblasts (hCTs) and the human trophoblast-like choriocarcinoma cell line BeWo cells were exposed to Anandamide (AEA). It was investigated the cellular pathways involved in cell death, by the assessment of cell morphology, caspases activity, mitochondrial membrane potential (Δψm), reactive oxygen/nitrogen species (ROS/RNS) and western blot of cleaved Poly (ADP-ribose) polymerase 1 (PARP-1), truncated Bid (t-Bid) and IκB-α.

RESULTS

AEA decreased hCTs viability and induced morphological features of apoptosis (chromatin condensation and fragmentation), caspase-3/7 activation and PARP-1 cleavage. In BeWo, AEA also increased the activities of caspase-3/7 and 9, induced loss in Δψm and production of ROS/RNS. These effects were reversed by either CB1 or CB2 antagonists, whereas the increase in caspase-3/7 activity was only reversed with CB2 blockage. AEA-treated cells showed increased caspase-8 activation and formation of t-Bid, suggesting the interplay between intrinsic and extrinsic apoptotic pathways. AEA also increased IκB-α expression, a NF-κB regulatory protein.

CONCLUSION

Our results highlight the importance of eCBs in cytotrophoblast cell apoptosis and indicate that a crosstalk between intrinsic and extrinsic apoptotic pathways is involved in AEA-induced effects.

2-arachidonoylglycerol effects in cytotrophoblasts: metabolic enzymes expression and apoptosis in BeWo cells

The major endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) is a member of the endocannabinoid system (ECS) that participates in cell proliferation and apoptosis, important events for the homoeostasis of biological systems. The formation of placenta is one of the most important stages of pregnancy and its development requires highly regulated proliferation, differentiation and apoptosis of trophoblasts. Anomalies in these processes are associated with gestational pathologies. In this work, we aimed to study the involvement of 2-AG in cytotrophoblast cell turnover. We found that 2-AG biosynthetic (diacylglycerol lipase A) and degradative (monoacylglycerol lipase) enzymes are expressed in human cytotrophoblasts and in BeWo cells. We also found that 2-AG induces a decrease in cell viability in a time- and concentration-dependent manner and exerts antiproliferative effects. The loss of cell viability induced by a 48-h treatment with 2-AG (10 μM) was accompanied by chromatin fragmentation and condensation, morphological features of apoptosis. Additionally, 2-AG induced an increase in caspase 3/7 and 9 activities, a loss of mitochondrial membrane potential (Δψm) and an increase in reactive oxygen species (ROS)/reactive nitrogen species (RNS) generation, suggesting the activation of the mitochondrial pathway. Moreover, whereas Δψm loss and ROS/RNS generation were significantly attenuated by the antagonists of both the cannabinoid receptors 1 and 2 (CB1 and CB2), the increase in caspase 3/7 and 9 activities and loss of cell viability were reversed only by the antagonist of CB2 receptor; the blockage of the eCB membrane transporter and the depletion of cholesterol failed to reverse the effects of 2-AG. Therefore, this work supports the importance of cannabinoid signalling during cytotrophoblast cell turnover and that its deregulation may be responsible for altered placental development and poor pregnancy outcomes.

The long non-coding RNA NEAT1 is increased in IUGR placentas, leading to potential new hypotheses of IUGR origin/development

INTRODUCTION

Intrauterine Growth Restriction (IUGR) is a multifactorial disease defined by an inability of the fetus to reach its growth potential. IUGR not only increases the risk of neonatal mortality/morbidity, but also the risk of metabolic syndrome during adulthood. Certain placental proteins have been shown to be implicated in IUGR development, such as proteins from the GH/IGF axis and angiogenesis/apoptosis processes.

METHODS

Twelve patients with term IUGR pregnancy (birth weight < 10th percentile) and 12 CTRLs were included. mRNA was extracted from the fetal part of the placenta and submitted to a subtraction method (Clontech PCR-Select cDNA Subtraction).

RESULTS

One candidate gene identified was the long non-coding RNA NEAT1 (nuclear paraspeckle assembly transcript 1). NEAT1 is the core component of a subnuclear structure called paraspeckle. This structure is responsible for the retention of hyperedited mRNAs in the nucleus. Overall, NEAT1 mRNA expression was 4.14 (±1.16)-fold increased in IUGR vs. CTRL placentas (P = 0.009). NEAT1 was exclusively localized in the nuclei of the villous trophoblasts and was expressed in more nuclei and with greater intensity in IUGR placentas than in CTRLs. PSPC1, one of the three main proteins of the paraspeckle, co-localized with NEAT1 in the villous trophoblasts. The expression of NEAT1_2 mRNA, the long isoform of NEAT1, was only modestly increased in IUGR vs. CTRL placentas.

DISCUSSION/CONCLUSION

The increase in NEAT1 and its co-localization with PSPC1 suggests an increase in paraspeckles in IUGR villous trophoblasts. This could lead to an increased retention of important mRNAs in villous trophoblasts nuclei. Given that the villous trophoblasts are crucial for the barrier function of the placenta, this could in part explain placental dysfunction in idiopathic IUGR fetuses.