Inhibition of Cytotrophoblastic (JEG-3) Cell Invasion by Interleukin 12 Involves an Interferon γ-mediated Pathway

Maternal and Neonatal Outcomes in Vedolizumab- and Ustekinumab-Exposed Pregnancies: Results From the PIANO Registry

BACKGROUND

Pregnancy outcomes in patients with inflammatory bowel disease with quiescent disease are similar to those in the general population. Data from the Pregnancy Inflammatory bowel disease And Neonatal Outcomes registry have demonstrated the safety of antitumor necrosis factor (TNF) α agents and thiopurines in pregnancy. The objective of this study was to provide information from the Pregnancy Inflammatory bowel disease And Neonatal Outcomes registry on maternal and fetal outcomes in patients exposed to the newer biologics ustekinumab (UST) and vedolizumab (VDZ).

METHODS

In this multicenter prospective observational study, we included pregnant women with singleton pregnancies and a diagnosis of inflammatory bowel disease. Questionnaires were administered to women at study intake, each subsequent trimester, delivery, and 4, 9, and 12 months after birth. Bivariate analyses were used to determine the independent effects of specific drug classes on outcomes. The exposure cohorts were VDZ, UST, anti-TNF, immunomodulators, and combination with anti-TNF and immunomodulators. All were compared with no exposure and with biologics/immunomodulators.

RESULTS

There were 1,669 completed pregnancies with 1,610 live births. The maternal mean age was 32.1 (SD 4.6) years at delivery with 66 VDZ exposed and 47 UST exposed. Women on UST were more likely to have Crohn's disease. There was no increased risk of spontaneous abortion, small for gestational age, low birth weight, neonatal intensive care unit stay, congenital malformations, or intrauterine growth restriction with in utero VDZ or UST exposure. The rate of preterm birth was lower (0.0%) for the UST-exposed cohort when compared with other cohorts including VDZ (13.8%), anti-TNF (8.2%), combination therapy (14.2%), immunomodulators (12.3%), and unexposed (9.7%) ( P = 0.03). Rates of serious infections at birth, 4 months, and within the first 12 months of life were comparable among all cohorts. Nonserious infections were lower at 12 months in UST-exposed pregnancies. There was no increased risk signal for placental complications in the VDZ cohort. UST infant concentrations at birth were increased whereas VDZ concentrations were overall decreased compared with maternal serum drug concentration.

DISCUSSION

This analysis of UST and VDZ exposure during pregnancy suggests no increase in complications compared with TNF, immunomodulators, and combination TNF/immunomodulators. No signal was found for increased placental events with either therapy. Continuation of UST and VDZ throughout pregnancy is recommended.

Oncostatin M and STAT3 Signaling Pathways Support Human Trophoblast Differentiation by Inhibiting Inflammatory Stress in Response to IFNγ and GM-CSF

Interleukin-6 (IL-6) superfamily cytokines play critical roles during human pregnancy by promoting trophoblast differentiation, invasion, and endocrine function, and maintaining embryo immunotolerance and protection. In contrast, the unbalanced activity of pro-inflammatory factors such as interferon gamma (IFNγ) and granulocyte-macrophage colony-stimulating factor (GM-CSF) at the maternal-fetal interface have detrimental effects on trophoblast function and differentiation. This study demonstrates how the IL-6 cytokine family member oncostatin M (OSM) and STAT3 activation regulate trophoblast fusion and endocrine function in response to pro-inflammatory stress induced by IFNγ and GM-CSF. Using human cytotrophoblast-like BeWo (CT/BW) cells, differentiated in villous syncytiotrophoblast (VST/BW) cells, we show that beta-human chorionic gonadotrophin (βhCG) production and cell fusion process are affected in response to IFNγ or GM-CSF. However, those effects are abrogated with OSM by modulating the activation of IFNγ-STAT1 and GM-CSF-STAT5 signaling pathways. OSM stimulation enhances the expression of STAT3, the phosphorylation of STAT3 and SMAD2, and the induction of negative regulators of inflammation (e.g., IL-10 and TGFβ1) and cytokine signaling (e.g., SOCS1 and SOCS3). Using STAT3-deficient VST/BW cells, we show that STAT3 expression is required for OSM to regulate the effects of IFNγ in βhCG and E-cadherin expression. In contrast, OSM retains its modulatory effect on GM-CSF-STAT5 pathway activation even in STAT3-deficient VST/BW cells, suggesting that OSM uses STAT3-dependent and -independent mechanisms to modulate the activation of pro-inflammatory pathways IFNγ-STAT1 and GM-CSF-STAT5. Moreover, STAT3 deficiency in VST/BW cells leads to the production of both a large amount of βhCG and an enhanced expression of activated STAT5 induced by GM-CSF, independently of OSM, suggesting a key role for STAT3 in βhCG production and trophoblast differentiation through STAT5 modulation. In conclusion, our study describes for the first time the critical role played by OSM and STAT3 signaling pathways to preserve and regulate trophoblast biological functions during inflammatory stress.

Myeloperoxidase enhances the migration and invasion of human choriocarcinoma JEG-3 cells

Myeloperoxidase (MPO) is one of the most abundant proteins in neutrophil granules. It catalyzes the production of reactive oxygen species, which are important in inflammation and immune defense. MPO also binds to several proteins, lipids, and DNA to alter their function. MPO is present at the feto-maternal interface during pregnancy, where neutrophils are abundant. In this study, we determined the effect of MPO on JEG-3 human choriocarcinoma cells as a model of extravillous trophoblasts (EVTs) during early pregnancy. We found that MPO was internalized by JEG-3 cells and localized to the cytoplasm and nuclei. MPO internalization and activity enhanced JEG-3 cell migration and invasion, whereas this effect was impaired by pre-treating cells with heparin, to block cellular uptake, and MPO-activity inhibitor 4-ABAH. This study identifies a novel mechanism for the effect of MPO on EVT function during normal pregnancy and suggests a potential role of MPO in abnormal pregnancies.

The Role of Interferon (IFN)-γ in Extravillous Trophoblast Cell (EVT) Invasion and Preeclampsia Progression

The involvement of the immune system in pregnancy is a controversial subject. The functions of T helper (Th) 1 and Th2 cells have been proposed, that Th1 cytokines promoting allograft rejection may impair pregnancy, whereas Th2-type cytokines suppressing Th1 responses improve allograft tolerance and hence embryonic survival. Maternal-fetal tolerance begins in the uterus; therefore, optimal adaptation to the fetus is the result of a complex interference. The invasion of extravillous trophoblast cells (EVTs) into the decidua and the inner third of the myometrium is essential for a healthy pregnancy. The mechanisms that influence trophoblast invasion are unknown; however, cytokines from uterine natural killer (uNK) cells, NKT cells, macrophages, and T cells appear to be involved. All these cells are major sources of interferon gamma (IFN-γ). Recent studies have shown that IFN-γ can inhibit EVT invasion via a mechanism dependent on an increase in EVT apoptosis and a decrease in matrix metalloproteinases (MMPs). Regarding controversies in this context, this study aimed to comprehensively review the role of IFN-γ and IFN-γ-producing cells in EVT invasion, successful pregnancy, and preeclampsia.

(Dis)similarities between the Decidual and Tumor Microenvironment

Placenta-specific trophoblast and tumor cells exhibit many common characteristics. Trophoblast cells invade maternal tissues while being tolerated by the maternal immune system. Similarly, tumor cells can invade surrounding tissues and escape the immune system. Importantly, both trophoblast and tumor cells are supported by an abetting microenvironment, which influences invasion, angiogenesis, and immune tolerance/evasion, among others. However, in contrast to tumor cells, the metabolic, proliferative, migrative, and invasive states of trophoblast cells are under tight regulatory control. In this review, we provide an overview of similarities and dissimilarities in regulatory processes that drive trophoblast and tumor cell fate, particularly focusing on the role of the abetting microenvironments.

Association of interleukin-12B gene polymorphisms and mRNA expression with preeclampsia

OBJECTIVE

To explore the effects of functional genetic polymorphisms of the interleukin-12B (IL-12B) gene on the susceptibility to preeclampsia in northern Chinese women.

STUDY DESIGN

Maternal peripheral blood from 306 preeclamptic women and 310 control women and the placentas from 52 preeclamptic and 55 control women were collected. Two polymorphisms (rs17860508 and rs3212227) of the IL-12B gene were genotyped by polymerase chain reaction (PCR) with a direct sequencing method. The mRNA expression of IL-12B in the placentas was measured by quantitative real-time PCR (qRT-PCR).

RESULTS

Significant differences were observed between preeclamptic women and the control group in the genotype frequencies of rs17860508 (P = 0.017). Compared with the TTAGAG/TTAGAG genotype of rs17860508, the GC/GC genotype were associated with a higher risk of preeclampsia (adjusted OR: 1.95; 95% CI = 1.18-3.22; P = 0.009), especially the early-onset preeclampsia (adjusted OR: 2.40; 95% CI = 1.23-4.68; P = 0.010). The qRT-PCR results showed that the mRNA levels of IL-12B were significantly higher in the placentas of preeclampsia patients than that in the placentas of controls (P = 0.001). Moreover, the expression of IL-12B mRNA was significantly higher in the placentas of patients carrying the GC/GC genotype than in those carrying the TTAGAG/GC (P = 0.007) and TTAGAG/TTAGAG (P = 0.005) genotypes.

CONCLUSION

The GC/GC genotype of rs17860508 polymorphism may be a risk factor for the early-onset preeclampsia by upregulating the expression of IL-12B in northern Chinese women.

Downregulation of HIF-2α Enhances Apoptosis and Limits Invasion in Human Placental JEG-3 Trophoblast Cells

Pre-eclampsia, one of the major disorders of pregnancy, is characterized by inadequate trophoblast invasion and defective trophoblast-mediated remodeling of placental vasculature. Hypoxia-inducible transcription factor (HIF)-2α plays a critical role in regulating cellular function of trophoblasts; however, its role in placental development and in the pathogenesis of pre-eclampsia remains elusive. CCK-8 assay was used to detect cell viability. Invasion assay was performed to determine the effect of HIF-2α on trophoblast function. Flow cytometry was used for detecting apoptosis and cell cycle. The mRNA and protein expressions of HIF-2α, VEGF, iNOS, and ET-1 were determined by quantitative real-time PCR and western blot techniques. The roles of HIF-2α in JEG-3 trophoblast cells were examined using siRNA technology. The presence of HIF-2α siRNA reduced the levels of cell viability after 48 h incubation, and the cell viability further reduced at 72 h. Besides, HIF-2α siRNA enhanced trophoblast apoptosis, as determined by flow cytometric measurement. Increased G1-phase and decreased S-phase cell population were induced by HIF-2α siRNA based on the determination of cell cycle distribution using propidium iodide staining. Furthermore, the invasive ability of JEG-3 trophoblasts was significantly reduced by HIF-2α siRNA. In addition, knockdown of the HIF-2α gene significantly decreased VEGF, iNOS, and ET-1 levels in JEG-3 human trophoblasts. Our findings provide preliminary evidence of the functions of HIF-2α in trophoblast biology and suggest that the downregulation of HIF-2α enhances cell apoptosis and limits trophoblast invasion.

Safety of New Biologics (Vedolizumab and Ustekinumab) and Small Molecules (Tofacitinib) During Pregnancy: A Review

Two new biological drugs (vedolizumab and ustekinumab) and one small molecule (tofacitinib) have been recently approved for the treatment of inflammatory bowel disease. Therefore, we must be familiar with the safety of these "new" drugs during pregnancy and breastfeeding. In the present article, we critically review available data on the safety of new biologics (vedolizumab and ustekinumab) and small molecules (tofacitinib) during pregnancy and breastfeeding, with special focus on women with inflammatory bowel disease. Bibliographical searches (MEDLINE) up to April 2020 were performed. The timing and mechanisms of placental transfer of vedolizumab and ustekinumab are expected to be similar to anti-TNF agents. Animal studies show no evidence of adverse effects on pre- or post-natal development after administration of vedolizumab and ustekinumab. Just a few studies including patients treated with vedolizumab or ustekinumab during pregnancy have been published, reporting uneventful pregnancies in most cases. The clinical programme of both drugs and post-marketing studies showed no new safety concerns. Due to the expected safety of vedolizumab and ustekinumab during pregnancy, it may be recommended to plan the final pregnancy dose approximately 8 or 12 weeks, respectively, before the estimated date of delivery. Live vaccines should be avoided for up to a year in children exposed in utero to vedolizumab or ustekinumab unless drug elimination has been documented. Miniscule amounts of vedolizumab and ustekinumab are transferred to breast milk, so breastfeeding is probably safe. There is no evidence of adverse effect of vedolizumab or ustekinumab paternal exposure. Regarding tofacitinib, it is reasonable to assume that this molecule crosses the placenta from the beginning of pregnancy. In animal studies, tofacitinib was feticidal and teratogenic in rats and rabbits, although at exposures many times greater than the standard human dose. Reported outcomes of pregnancy cases identified from tofacitinib randomised controlled trials, post-approval and non-interventional studies, and spontaneous adverse-event reporting appear similar to those observed in the general population. Nevertheless, at present, the use of tofacitinib during pregnancy should be avoided. Although no human studies have reported outcomes of breastfeeding with small molecules such as tofacitinib, this drug is present in lactating rat milk so, at present, breastfeeding should be avoided. Pregnancy among patients with paternal exposure to tofacitinib appears to be safe. In summary, we can conclude that new biologic agents (vedolizumab and ustekinumab) and small molecules (tofacitinib) should be used during pregnancy only if the benefits to the mother outweigh the risks to the mother and unborn child.

Transcriptomic analysis of interferon-γ-regulated genes in endometrial explants and their possible role in regulating maternal endometrial immunity during the implantation period in pigs, a true epitheliochorial placentation species

The implantation process requires precisely controlled interactions between the maternal uterine endometrium and the implanting conceptus. Conceptus-derived secretions affect endometrial cells to facilitate the adhesion and attachment of trophoblasts, and endometrial secretions support the growth and development of the conceptus. In pigs, the conceptus secretes a large amount of type II interferon, interferon-γ (IFNG), during the implantation period. However, the role of IFNG in the implantation process has not been fully understood in pigs. Thus, to determine the role of IFNG in the endometrium during early pregnancy in pigs, we treated endometrial explant tissues with increasing doses of IFNG and analyzed the transcriptome regulated by IFNG using an RNA-sequencing analysis. Data analyses identified 276 differentially regulated genes, their Gene Ontology terms, and 94 signature genes in a Gene Set Enrichment Analysis. Furthermore, we analyzed the expression of IFNG-regulated genes, including CIITA, KYNU, IDO1, WARS, and MHC class II molecules, in the endometrium throughout pregnancy and found that levels of those genes in the endometrium were highest on Day 15 of pregnancy, corresponding to the time of peak IFNG secretion by porcine conceptuses. In addition, immunohistochemical analyses revealed that CIITA, KYNU, and IDO proteins were expressed in a cell type- and pregnancy status-specific manner in the endometrium. These results show that genes overrepresented in endometrial tissues in response to IFNG were mainly related to immune responses, suggesting that conceptus-derived IFNG could play critical roles in regulating the maternal immune response for the establishment of pregnancy in pigs.

Investigation of human trophoblast invasion in vitro

BACKGROUND

In humans, inadequate trophoblast invasion into the decidua is associated with the 'great obstetrical syndromes' which include pre-eclampsia, foetal growth restriction (FGR) and stillbirth. The mechanisms regulating invasion remain poorly understood, although interactions with the uterine environment are clearly of central importance. Extravillous trophoblast (EVT) cells invade the uterus and transform the spiral arteries. Progress in understanding how they invade has been limited due to the lack of good in vitro models. Firstly, there are no non-malignant cell lines that have an EVT phenotype. Secondly, the invasion assays used are of limited use for the small numbers of primary EVT available from first-trimester placentas. We discuss recent progress in this field with the generation of new EVT lines and invasion assays using microfluidic technology.

OBJECTIVE AND RATIONALE

Our aim is to describe the established models used to study human trophoblast invasion in vivo and in vitro. The difficulties of obtaining primary cells and cell lines that recapitulate the phenotype of EVT are discussed together with the advantages and pitfalls of the different invasion assays. We compare these traditional end point assays to microfluidic assays where the dynamics of migration can be measured.

SEARCH METHODS

Relevant studies were identified by PubMed search, last updated on February 2020. A search was conducted to determine the number of journal articles published using the cell lines JEG-3, BeWo, JAR, HTR-8/Svneo, Swan-71 and primary human extravillous trophoblast in the last 5 years.

OUTCOMES

Deep trophoblast invasion into the maternal decidua is a particular feature of human pregnancy. This invasion needs to be finely regulated to allocate resources between mother and baby. A reliable source of EVT is needed to study in vitro how the uterine environment regulates this process. First, we critically discuss the issues with the trophoblast cell lines currently used; for example, most of them lack expression of the defining marker of EVT, HLA-G. Recently, advances in human stem cell and organoid technology have been applied to extraembryonic tissues to develop trophoblast cell lines that can grow in two (2D) and three dimensions (3D) and differentiate to EVT. This means that the 'trophoblast' cell lines currently in use should rapidly become obsolete. Second, we critically discuss the problems with assays to study trophoblast invasion. These lack physiological relevance and have simplified migration dynamics. Microfluidic assays are a powerful tool to study cell invasion because they require only a few cells, which are embedded in 3D in an extracellular matrix. Their major advantage is real-time monitoring of cell movement, enabling detailed analysis of the dynamics of trophoblast migration.

WIDER IMPLICATIONS

Trophoblast invasion in the first trimester of pregnancy remains poorly understood despite the importance of this process in the pathogenesis of pre-eclampsia, FGR, stillbirth and recurrent miscarriage. The new technologies described here will allow investigation into this critical process.

Changing the paradigm of IFN-γ at the interface between innate and adaptive immunity: Macrophage-derived IFN-γ

IFN-γ plays a critical role in the immune response to bacterial infections. It is established that IFN-γ is mainly produced by NK/ILC1 cells and T cells, and most of papers have rejected the biologic reality of alternative sources for more than 20 years. Here, we are proposing to revisit this dogma and discuss the role of macrophage-derived IFN-γ in bacterial infections. Our hypothesis is based on a panel of publications and is recently revived by our results on placenta, a chimeric organ in which the immune response is tailored to protect the fetus from mother's immune response. The culture of purified placental macrophages is associated with a production of IFN-γ that may contribute to fetal protection from bacterial infections before eliciting a Th1-like immune response potentially pathogenic for pregnancy. Hence, macrophage IFN-γ may be a novel actor of early crosstalk between innate and adaptive immunity in the context of host defense against bacterial infections.

Leukemia inhibitory factor regulates the activation of inflammatory signals in macrophages and trophoblast cells

The pleiotropic cytokine leukemia inhibitory factor (LIF) is a key gestational factor known to establish dynamic cellular and molecular cross talk at the feto-maternal interface. Previously, we described the regulatory role of the LIF-trophoblast-IL10 axis in the process of macrophage deactivation in response to pro-inflammatory cytokines. However, the direct regulatory effects of LIF in macrophage and trophoblast cell function remains elusive. In this study, we aimed to examine whether and how LIF regulates the behavior of macrophages and trophoblast cells in response to pro-inflammatory stress factors. We found that LIF modulated the activating effects of interferon-gamma (IFNγ) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in macrophages and trophoblast cells by reducing the phosphorylation levels of signal transducer and activator of transcription-1 (Stat1) and -5 (Stat5). Cell activation with IFNγ inhibited cell invasion and migration but this immobilizing effect was abrogated when macrophages and trophoblast cells were deactivated with LIF; macrophage cell motility restitution could in part be explained by the positive effects of LIF in Stat3 activation and matrix metalloproteinase 9 (MMP-9) expression. Pharmacological inhibition of Stat1 and Stat3 indicated that IFNγ-induced Stat1 activation mediated macrophage motility inhibition, and that cell motility in IFNγ-activated macrophages is restored via LIF-induced Stat3 activation and Stat1 inhibition. Moreover, IFNγ-induced TNFα gene expression was also abrogated by LIF through Stat1 inhibition and Stat3 activation. Finally, we have found that cell invasion of trophoblast cells is inhibited when they were cocultured with GM-CSF-differentiated, IFNγ-stimulated macrophages. This effect, however, was inhibited when macrophages were exposed to LIF. Overall, this in vitro study reveals for the first time the anti-inflammatory and pro-gestational activities of LIF by acting directly on macrophages and trophoblast cells.

Pregnant women with inflammatory bowel disease: the effects of biologicals on pregnancy, outcome of infants, and the developing immune system

Relapse of inflammatory bowel disease (IBD) during conception and pregnancy has been associated with a negative pregnancy outcome. Therefore, it is advised to maintain drugs in order to prevent relapse. The effect of drugs, which cross the placenta, on children who have been exposed during pregnancy will be discussed in this review. Areas covered: A literature search was performed using the following search terms: inflammatory bowel disease, pregnancy, infant, antitumor necrosis factor alpha, infliximab, adalimumab, golimumab, certolizumab, anti-integrins, vedolizumab, anti-interleukin (IL)-12/23 ustekinumab, placenta, vaccination. Other studies were identified by using references from articles identified through our original literature search. The occurrence of unfavorable pregnancy outcome and congenital malformations does not seem to be increased after exposure to anti-TNFα, but the effects on the developing immune system are largely unknown. For anti-integrins and anti IL-12/23, the numbers of exposed pregnancies are too small to draw any conclusions. Expert commentary: Follow-up of the developing immune system in children exposed to these drugs seems warranted, preferably in a prospective study design.

Increased AIF-1-mediated TNF-α expression during implantation phase in IVF cycles with GnRH antagonist protocol

STUDY QUESTION

Is allograft inflammatory factor-1 (AIF-1), a cytokine associated with inflammation and allograft rejection, aberrantly elevated in in vitro fertilization (IVF) cycles with gonadotropin-releasing hormone (GnRH) antagonist protocol with potential effects on endometrial receptivity?

SUMMARY ANSWER

Our findings indicated AIF-1 is increased in IVF cycles with GnRH antagonist protocol and mediates greater TNF-α expression during implantation phase, which may be unfavorable for embryo implantation.

WHAT IS KNOWN ALREADY

Studies have shown that GnRH antagonist protocol cycles have lower implantation and clinical pregnancy rates than GnRH agonist long protocol cycles. Endometrial receptivity but not embryo quality is a key factor contributing to this phenomenon; however, the mechanism is still unknown.

STUDY DESIGN, SIZE, DURATION

Implantation and pregnancy rates were studied in 238 patients undergoing their first cycle of IVF/ICSI between 2012 and 2014. Forty of these patients opted to have no fresh embryo replacement and were divided into two equal groups: (i) GnRH antagonist protocol and (ii) GnRH agonist long protocol, group 3 included 20 infertile women with a tubal factor in untreated cycles. During the same interval, endometrial tissues were taken from 18 infertile women with a tubal factor in the early proliferative phase, late proliferative phase, and mid-secretory phase of the menstrual cycle (n = 6/group).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Microarray analysis, RT-qPCR, Western blot analysis, immunohistochemistry were used to investigate the expression levels of AIF-1 and the related cytokines (TNF-α, IL1β, IL1RA, IL6, IL12, IL15 and IL18). The effect of AIF-1 on uterine receptivity was modeled using in vitro adhesion experiments (coculture of JAR cells and Ishikawa cells).

MAIN RESULTS AND THE ROLE OF CHANCE

The expression of AIF-1 was the highest in early proliferative phase, decreasing thereafter in the late proliferative phase, and almost disappearing in the mid-secretory phase, indicating that low AIF-1 expression might be important for embryo implantation during implantation phase. Microarray results revealed that AIF-1 was upregulated in the antagonist group compared with the control group (fold change [FC] = 3.75) and the agonist (FC = 2.20) group. The raw microarray data and complete gene expression table were uploaded to GEO under the accession number of GSE107914. Both the mRNA and protein expression levels of AIF-1 and TNF-α were the higher in the antagonist group than in the other two groups (P < 0.05) which did not differ significantly (P > 0.05). The protein levels of TNF-α in both Ishikawa cells and primary endometrial cells were significantly increased (P < 0.05) at 96 h after transfection with the AIF-1 expression vector, indicating that TNF-α was mediated by AIF-1 in endometrial cells. Overexpression of AIF-1 in Ishikawa cells inhibited adhesion of JAR cells to them. Thus, increased AIF-1 might inhibit adhesion during implantation via raised TNF-α.

LIMITATIONS REASONS FOR CAUTION

The sample size of the microarray was small, which might weaken the accuracy of our results; however, the sample size of RT-qPCR and the Western blotting assays were sufficient to compensate for this deficiency in our study. In addition, the aberrant AIF-1 and thus TNF-α expression is one of many factors that may contribute to limiting implantation success. Therefore, further extensive in vitro mechanistic and in vivo animal studies are needed to assess the actual functional impact of this pathway.

WIDER IMPLICATIONS OF THE FINDINGS

Anti-TNF-α therapy might mitigate the adverse effects of GnRH antagonist on endometrial receptivity and improve the implantation rate in GnRH antagonist protocols in IVF.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Natural Science Foundation of China, Grant numbers 81771656 and 81370763; Clinical research special fund of Chinese Medical Association, Grant number 16020480664; Shanghai Jiao Tong University Medicine-Engineering Fund, Grant number YG2017ZD11 and YG2017MS57; and the Merck-Serono China Research Fund for Fertility Agreement. P.C.K.L. is supported by a Canadian Institutes of Health Research Foundation Scheme Grant 143317. None of the authors has any competing interests.

IL-12-mediated transcriptional regulation of matrix metalloproteinases

Matrix metalloproteinases (MMPs) are extracellular matrix (ECM) remodelling enzymes involved in developmental processes, tissue remodelling and repair, inflammatory and immune diseases and cancer. In a recent issue of Bioscience Reports (vol. 37, issue 6, BSR20170973), Liu and colleagues investigated the expression of MMPs such as MMP-1 (interstitial collagenase), MMP-3 (stromelysin 1) and MMP-13 (collagenase 3) in human periodontal ligament fibroblasts (hPDLFs) regulated by interleukin-12 (IL-12), a cytokine implicated in inflammatory and immune responses. They showed that IL-12 activates canonical nuclear factor-κB (NF-κB) signalling leading to increased expression of MMP-1, MMP-3 and MMP-13, and to a smaller reduction in the expression of MMP-2 (gelatinase A) and MMP-9 (gelatinase B) at both mRNA and protein levels, with corresponding changes in the secreted levels of these ECM-remodelling and immune regulatory metalloproteinases. While canonical NF-κB signalling regulates these MMPs, it also interacts with additional factors to determine whether some of these MMPs are induced or downregulated, in response to IL-12. Here, we comment on the possible mechanisms of IL-12-mediated transcriptional regulation of MMPs.

Decrease in invasion of HTR-8/SVneo trophoblastic cells by interferon gamma involves cross-communication of STAT1 and BATF2 that regulates the expression of JUN

Trophoblast invasion is one of the critical steps during embryo implantation. IFNG secreted during pregnancy by uterine NK cells acts as a negative regulator of invasion. IFNG in a dose dependent fashion inhibits invasion of HTR-8/SVneo trophoblastic cells. It phosphorylates STAT1 both at tyr 701 and ser 727 residues. Silencing of STAT1 significantly increases invasion (∼59%) of the cells. Based on NGS data, out of 207 genes, BATF2 expression was significantly increased after IFNG treatment. Silencing of BATF2 significantly increases the invasion of cells with (∼53%) or without (∼44%) treatment with IFNG. Expression of BATF2 and STAT1 is dependent on each other, silencing of one significantly inhibit the expression of other. Interestingly, phosphorylated JUN is also regulated by BATF2 and STAT1. Collectively, these findings showed that decrease in the invasion of HTR-8/SVneo cells after IFNG treatment is controlled by STAT1 and BATF2, which further regulates the expression of JUN.

Effect of Cytokines on the Formation Tube-Like Structures by Endothelial Cells in the Presence of Trophoblast Cells

Despite ample data on cytokine secretion in the uteroplacental interface, the influence of microenvironment cells, in particular, trophoblast cells on angiogenesis and the role of cytokines in this process remain poorly studied. We studied the influence of cytokines on the formation of tube-like structures by endothelial cells in the presence of trophoblast cells and showed that trophoblast cells suppressed the angiogenic potential of endothelial cells. Antiangiogenic cytokines IFN-γ, IL-10, TNF-α, and TGFβ via modulation of trophoblast cells stimulated the formation of tube-like structures by endothelial cells. In the co-culture of endothelial and trophoblast cells, the effects of cytokines changed and they gained additional regulatory functions.

An In Vitro Coculture Model to Study Cytokine Profiles of Natural Killer Cells During Maternal Immune Cell-Trophoblast Interactions

OBJECTIVES

The cytokine milieu at the implantation site plays a role in human pregnancy. Th2 cytokines, such as interleukin (IL)-4 and IL-10, stimulate growth and development of placenta, whereas Th1 cytokines, such as tumor necrosis factor-alpha (TNF-alpha), are associated with pregnancy complications. Natural killer (NK) cells predominate at the implantation site. The aim of the present study is to investigate cytokine expression in NK cells when they are in close contact with JEG-3 trophoblast-like cells using an in vitro coculture model.

METHODS

Female peripheral blood mononuclear cells (PBMCs) were cocultured with JEG-3 cells for 24 hours. PBMCs were harvested from the cocultures and stimulated with 25 ng/mL phorbol myristate acetate and 1 micromol/mL ionomycin in the presence of 2 micromol/mL monensin. NK cells were analyzed by flow cytometry for intracellular TNF-alpha, interferon-gamma (IFN-gamma), and IL-4 and IL-10 cytokines. Controls were PBMCs cultured without JEG-3 cells.

RESULTS

The proportion of CD56+/TNF-alpha(+) NK cells was significantly decreased when they were in coculture with JEG-3 cells (26.1%) as compared to without JEG-3 cell coculture (40.8%) (P < .05). There was no difference in the proportion of CD56(+) NK cells expressing intracellular IFN-gamma, IL-4, and IL-10. Down-regulation of CD56+/TNF-alpha(+) NK cell levels was dependent on direct cell-to-cell contact between NK cells and JEG-3 cells. The expression of human leukocyte antigen (HLA)-G on trophoblast cell lines did not affect CD56+/TNF-alpha(+) NK cell levels under these experimental conditions.

CONCLUSION

We report that JEG-3 cells induce down-regulation of intracellular CD56+/TNF-alpha(+) NK cell levels. It is speculated that trophoblasts may secure themselves from NK cell cytotoxicity via this mechanism.

Molecular Cross-Talk at the Feto-Maternal Interface

Molecular cross-talk at the feto-maternal interface occurs between many different cell types, including uterine leukocytes, extravillous trophoblast cells, and uterine spiral arteries, is essential for the establishment and maintenance of pregnancy. This review concentrates on human pregnancy and examines three main areas in which cross-talk occurs; immune tolerance, regulation of extravillous trophoblast invasion, and remodeling of the uterine spiral arteries.

Anti-metastatic effects of antrodan, the Antrodia cinnamomea mycelia glycoprotein, in lung carcinoma cells

This study investigated the anti-metastatic effects of antrodan, the glycoprotein from Antrodia cinnamomea (AC) mycelia, through direct actions and indirect immunomodulatory effects in Lewis lung carcinoma (LLC). Antrodan was isolated from AC mycelia by alkali extraction, acid precipitation, and purification using sepharose CL-6B column chromatography. In the direct anti-metastatic action, antrodan (30-70 μg/mL) was found to significantly inhibit invasion and migration of LLC cells, and these effects involved up-regulation of tissue inhibitor of matrix metalloproteinase (TIMP)-1, TIMP-2, and nm23-H1 protein expression leading to decreased activities and protein expression of MMP-2 and MMP-9. For testing the indirect immunomodulatory effect, antrodan was incubated for 3d with mononuclear cells (MNCs) isolated from human peripheral blood to obtain the condition medium (CM). Antrodan significantly increased interleukin (IL)-12 and IL-1β levels, but decreased TNF-α, IL-6 and IL-8 levels in the MMC-CM, which also significantly inhibited invasion, migration, and the activities and protein expression of MMP-2 and MMP-9, but significantly increased protein expression of TIMP-1, TIMP-2, and nm23-H1 in LLC cells. The indirect immunomodulatory effect of antrodan was stronger than the direct anti-metastatic effect at the same concentrations (50 and 60 μg/mL). Overall, the results suggest the anti-metastatic potential of antrodan in LLC cells.

Role of IGF2BP3 in trophoblast cell invasion and migration

The insulin-like growth factor-2 mRNA-binding protein 3 (IGF2BP3) is a member of a highly conserved protein family that is expressed specifically in placenta, testis and various cancers, but is hardly detectable in normal adult tissues. IGF2BP3 has important roles in RNA stabilization and translation, especially during early stages of both human and mouse embryogenesis. Placenta is an indispensable organ in mammalian reproduction that connects developing fetus to the uterine wall, and is responsible for nutrient uptake, waste elimination and gas exchange. Fetus development in the maternal uterine cavity depends on the specialized functional trophoblast. Whether IGF2BP3 plays a role in trophoblast differentiation during placental development has never been examined. The data obtained in this study revealed that IGF2BP3 was highly expressed in human placental villi during early pregnancy, especially in cytotrophoblast cells (CTBs) and trophoblast column, but a much lower level of IGF2BP3 was detected in the third trimester placental villi. Furthermore, the expression level of IGF2BP3 in pre-eclamptic (PE) placentas was significantly lower than the gestational age-matched normal placentas. The role of IGF2BP3 in human trophoblast differentiation was shown by in vitro cell invasion and migration assays and an ex vivo explant culture model. Our data support a role of IGF2BP3 in promoting trophoblast invasion and suggest that abnormal expression of IGF2BP3 might be associated with the etiology of PE.

The role of interferons in early pregnancy

The interferons (IFNs) form part of the large family of glycoproteins known as cytokines. They are secreted by host cells as a line of defence against pathogens and certain tumours. IFNs affect cell proliferation and differentiation and also play a very important role in the functioning of the immune system. Miscarriage in both humans has been associated with higher levels of IFN, particularly IFN-γ. However, this cytokine is evidently vital in successful murine pregnancies since it is involved in maintaining the decidual layer in addition to remodelling of the vasculature in the uterus. The effects of IFN on human pregnancies are more difficult to study. Hence, there is still a lot more to be discovered in the hope of reaching a definite conclusion regarding the impact of IFN.

The tumor suppressor gastrokine-1 is expressed in placenta and contributes to the regulation of trophoblast migration

INTRODUCTION

Gastrokine-1 (GKN1) is a secreted auto-/paracrine protein, described to be expressed in the gastric mucosa. In gastric cancers GKN1 expression is commonly down-regulated. While current research focusses on the exploration of tumor-suppressive properties of GKN1 with regard to its potential clinical use in the treatment of gastroenterologic tumor disease, nothing is known about GKN1 expression and function in other organ systems. We investigated GKN1 expression in placental tissue and cells.

MATERIALS AND METHODS

GKN1 was localized using immunohistochemistry in first and third trimester placental tissue, hydatidiform moles and various gestational trophoblastic neoplasias. We determined the expression of GKN1 in immunomagnetic bead-separated term placental cells and in choriocarcinoma cell lines. The role of GKN1 for JEG-3 migration was studied using live cell imaging. E-cadherin, MMP-2 and -9, TIMP-1 and -2, as well as urokinase (uPA) expression levels were determined.

RESULTS

GKN1 is expressed in healthy third trimester placentas. Its expression is specifically limited to the extravillous trophoblast (EVT). GKN1 expression is significantly reduced in choriocarcinoma cell lines and gestational trophoblastic neoplasias. GKN1 attenuates the migration of JEG-3 choriocarcinoma cells in vitro, possibly via AKT-mediated induction of E-cadherin. GKN1 treatment reduced MMP-9 expression in JEG-3.

DISCUSSION

Besides its role in gastric physiology our results clearly indicate regulatory functions of GKN1 in the EVT at the feto-maternal interface during pregnancy. Based on our findings in the JEG-3 choriocarcinoma cell line, an auto-/paracrine role of GKN1 for EVT motility and villous anchorage at the basal plate is conceivable. Thus, the tumor suppressor GKN1 is expressed in placental EVT and might contribute to the regulation of EVT migration/invasion.

Comparative analysis of the invasion-associated genes expression pattern in first trimester trophoblastic (HTR-8/SVneo) and JEG-3 choriocarcinoma cells

Several cellular models of trophoblast have been proposed to understand their invasion. We had reported that JEG-3 and HTR-8/SVneo cells show differential invasive behavior in response to IL-11 treatment. So, the present study aims to compare the expression of invasion-associated molecules in these two cell lines by performing cDNA microarray followed by quantitative RT-PCR. We have observed that HTR-8/SVneo cells have significantly higher invasiveness than JEG-3 cells, which might be due to higher expression of proteases and signaling intermediates of JAK/STAT and MAPK signaling pathways. Like extravillous trophoblasts (EVTs), a higher expression of functionally significant proteases like MMP1, MMP2, MMP9, PLAU etc in HTR-8/SVneo cells, project them as a close mimic of EVTs under in vitro conditions.

Triggering of Toll-like receptor 4 on metastatic breast cancer cells promotes αvβ3-mediated adhesion and invasive migration

Triggering of Toll-like receptor 4 (TLR4) on tumor cells has been found to promote tumor progression by promoting tumor cell proliferation and survival. So far, however, the effect of TLR4 signaling on tumor metastasis has not been well elucidated. Here, we report that triggering of TLR4 on metastatic breast cancer cells could reciprocally regulate the expression of αvβ3 and the expressions of TPM1 and maspin, and promote αvβ3-mediated adhesion and invasive migration of the cells. In metastatic breast cancer cells, TLR4 signaling increased the expression of integrin αvβ3 by activating NF-κB, resulting in the increased adhesion capacity of tumor cells to the ligand for αvβ3, and the increased polymerization of actin and production of MMP-9 in tumor cells in response to ECM. HoxD3 was required for the up-regulation of αv and β3 expressions by NF-κB. Moreover, TLR4 signaling increased the expression of miR-21 in breast cancer cells by activating NF-κB. Accordingly, the expressions of TPM1 and maspin were decreased at protein level, whereas the transcription activity of these genes was not influenced. Consistent with the promoting effect on αvβ3-mediated adhesion and invasive migration, TLR4 signaling promoted the arrest of metastatic breast cancer cells in circulation and following invasion. The effect of TLR4 signaling could be abrogated by inhibiting NF-κB. These findings suggest that metastatic breast cancer cells could acquire higher metastatic potential due to triggering of TLR4 and activation of NF-κB in the cells, and that both TLR4 and NF-κB could be therapeutic targets for preventing metastasis of breast cancer cells.

Immunomodulator expression in trophoblasts from the feline immunodeficiency virus (FIV)-infected cat

Background

FIV infection frequently compromises pregnancy under experimental conditions and is accompanied by aberrant expression of some placental cytokines. Trophoblasts produce numerous immunomodulators that play a role in placental development and pregnancy maintenance. We hypothesized that FIV infection may cause dysregulation of trophoblast immunomodulator expression, and aberrant expression of these molecules may potentiate inflammation and compromise pregnancy. The purpose of this project was to evaluate the expression of representative pro-(TNF-α, IFN-γ, IL-1β, IL-2, IL-6, IL-12p35, IL-12p40, IL-18, and GM-CSF) and anti-inflammatory cytokines (IL-4, IL-5, and IL-10); CD134, a secondary co-stimulatory molecule expressed on activated T cells (FIV primary receptor); the chemokine receptor CXCR4 (FIV co-receptor); SDF-1α, the chemokine ligand to CXCR4; and FIV gag in trophoblasts from early-and late-term pregnancy.

Methods

We used an anti-cytokeratin antibody in immunohistochemistry to identify trophoblasts selectively, collected these cells using laser capture microdissection, and extracted total RNA from the captured cell populations. Real time, reverse transcription-PCR was used to quantify gene expression.

Results

We detected IL-4, IL-5, IL-6, IL-1β, IL-12p35, IL-12p40, and CXCR4 in trophoblasts from early-and late-term pregnancy. Expression of cytokines increased from early to late pregnancy in normal tissues. A clear, pro-inflammatory microenvironment was not evident in trophoblasts from FIV-infected queens at either stage of pregnancy. Reproductive failure was accompanied by down-regulation of both pro-and anti-inflammatory cytokines. CD134 was not detected in trophoblasts, and FIV gag was detected in only one of ten trophoblast specimens collected from FIV-infected queens.

Conclusion

Feline trophoblasts express an array of pro-and anti-inflammatory immunomodulators whose expression increases from early to late pregnancy in normal tissues. Non-viable pregnancies were associated with decreased expression of immunomodulators which regulate trophoblast invasion in other species. The detection of FIV RNA in trophoblasts was rare, suggesting that the high rate of reproductive failure in FIV-infected queens was not a direct result of viral replication in trophoblasts. The influence of placental immune cells on trophoblast function and pregnancy maintenance in the FIV-infected cat requires additional study.

Ubiquitin ligase cullin 7 induces epithelial-mesenchymal transition in human choriocarcinoma cells

Germ line mutations of the ubiquitin ligase cullin 7 (CUL7) are linked to 3-M syndrome and Yakuts short stature syndrome, both of which are characterized by pre- and post-natal growth retardation. CUL7 knock-out mice show placental and embryonic defects similar to intrauterine growth retardation, suggesting a role of CUL7 in placentation. CUL7 was found in this study to be highly expressed in first trimester invasive human placental villi as well as in HTR8/SVneo and B6Tert cells, two cell lines derived from human first trimester trophoblast cells. However, CUL7 levels in term trophoblast cells or JEG-3 cells, which are derived from human choriocarcinoma but exhibit weak invasion capacity, were low or undetectable. Forced expression of CUL7 in JEG-3 cells induced cell morphological changes characteristic of epithelial-mesenchymal transition, which was accompanied by a complete loss of the epithelial markers E-cadherin and P-cadherin and a significant elevation of mesenchymal markers Vimentin and N-cadherin. JEG-3 cells expressing CUL7 exhibited enhanced cell migration and invasion. Conversely, CUL7-specific RNA interference in HTR8/SVneo cells resulted in increased E-cadherin expression and reduced cell migration and invasion. Furthermore, CUL7 expression down-regulated E-cadherin mRNA expression by up-regulating ZEB1 and Slug, two transcriptional repressors of E-cadherin. Finally, CUL7-induced loss of E-cadherin expression was partially reversed by treatment of CUL7-expressing cells with the proteasome inhibitor MG-132. These results suggest that the CUL7 E3 ligase is a key regulator in trophoblast cell epithelial-mesenchymal transition and placental development.

The proprotein convertase furin in human trophoblast: Possible role in promoting trophoblast cell migration and invasion

Furin, a proprotein convertase (PC), is ubiquitously expressed and implicated in many physiological and pathological processes. This study is aimed to identify the role of furin in human trophoblast invasion and migration. Furin was found to be highly expressed in placental villi of both rhesus monkeys and human beings during early pregnancy. Specifically, furin was found in trophoblast column and trophoblast shell, regions where highly invasive cytotrophoblast cells invade the maternal decidua during human placentation. To determine whether furin plays any role in trophoblast invasion and migration, we employed human extravillous HTR8/SVneo cells in Matrigel invasion and transwell migration assays. Knocking-down furin expression by siRNA significantly inhibited invasion and migration of HTR8/SVneo cells (P<0.01), with corresponding decrease of matrix metalloproteinase-9 (MMP-9) activities. In contrast, over-expression of furin markedly increased cell invasion and migration (P<0.01), accompanied by significant increase of MMP-9 activities. Furthermore, furin siRNA significantly increased the levels of both tissue inhibitors of MMPs (TIMP)-1 and -2. Our results suggest that furin may play an important role in the invasion and migration of human trophoblast cells during early pregnancy.

Interleukin-11 increases invasiveness of JEG-3 choriocarcinoma cells by modulating STAT3 expression

Amongst the interleukin-6 (IL-6) family of cytokines, leukemia inhibitory factor (LIF) has been shown to promote trophoblast invasion and proliferation. In the present study interleukin-11 (IL-11), another member of the IL-6 family, was investigated for its role in regulating invasion, migration and proliferation of JEG-3 choriocarcinoma cells. JEG-3 cells, like extra villous trophoblast (EVT), express mRNA transcripts encoding IL-11 and IL-11 receptor-alpha (IL-11Ralpha). Treatment of JEG-3 cells with IL-11 led to an increase in invasion across Matrigel extracellular matrix without an increase in proliferation. There was a dose-dependent increase in activation of STAT3 under the influence of IL-11 with maximum Tyr705 phosphorylation by 10min. In addition, treatment of JEG-3 cells with IL-11 for 24h led to an increase in expression of unphosphorylated STAT1 and STAT3. Analysis of the nuclear fraction showed an increased localization of STAT3 following IL-11 treatment while STAT1 was absent. Silencing the expression of STAT3 by siRNA caused a 25% reduction in invasion compared to control cells, however this was not significant. Furthermore, treatment of STAT3-silenced JEG-3 cells with IL-11 led to a significant increase in invasion compared to STAT3-silenced cells without cytokine, but this was not significant compared to non-transfected control cells. Silencing the expression of gp130 but not of IL-6R abrogated the increase in invasiveness of JEG-3 cells following IL-11 treatment. In conclusion, activation and upregulation of STAT3 appears to be critical for the IL-11-mediated increase in invasiveness of JEG-3 cells.

Cytokine regulation during the formation of the fetal-maternal interface: focus on cell-cell adhesion and remodelling of the extra-cellular matrix

The establishment of human pregnancy requires the orchestration of substantial cell differentiation and tissue remodelling processes in the context of a complex dialogue between the receptive endometrium and the implanting blastocyst, and is therefore dependent upon a complex sequence of signalling events. Cytokines play an important role in each step of implantation, modulating expression of adhesion molecules on both the fetal and maternal surfaces, regulating expression of the proteases that remodel the extra-cellular matrix, and promoting invasion and differentiation of trophoblasts. Here we review the role of cytokines in regulating the establishment of the fetal-maternal interface, with a particular focus on regulation of the functional expression of CAMs, the ECM and of the proteinases that modulate their function.

Interferon gamma in successful pregnancies

Interferon gamma (IFNG) is a proinflammatory cytokine secreted in the uterus during early pregnancy. It is abundantly produced by uterine natural killer cells in maternal endometrium but also by trophoblasts in some species. In normal pregnancies of mice, IFNG plays critical roles that include initiation of endometrial vasculature remodeling, angiogenesis at implantation sites, and maintenance of the decidual (maternal) component of the placenta. In livestock and in humans, deviations in these processes are thought to contribute to serious gestational complications, such as fetal loss or preeclampsia. Interferon gamma has broader roles in activation of innate and adaptive immune responses to viruses and tumors, in part through upregulating transcription of genes involved in cell cycle regulation, apoptosis, and antigen processing/presentation. Despite this, rodent and human trophoblast cells show dampened responses to IFNG that reflect the resistance of these cells to IFNG-mediated activation of major histocompatibility complex (MHC) class II transplantation antigen expression. Lack of MHC class II antigens on trophoblasts is thought to facilitate survival of the semiallogeneic conceptus in the presence of maternal lymphocytes. This review describes the dynamic roles of IFNG in successful pregnancy and briefly summarizes data on IFNG in gestational pathologies.

Smurf2 participates in human trophoblast cell invasion by inhibiting TGF-beta type I receptor

Successful embryo implantation depends on the ability of the trophoblast cells to invade the endometrium and the receptivity of the endometrium. Unlike tumor invasion, trophoblast invasion is spatio-temporaly restricted. Transforming growth factor (TGF)-beta is a key inhibitory factor in the invasion of early trophoblast cells. Smad ubiquitination regulatory factor 2 (Smurf2), a HECT type E3 ubiquitin ligase, is an important regulator of the TGF-beta signaling pathway, targeting TGF-beta receptors and various Smads for proteasome-mediated degradation. In this context, we wished to determine whether Smurf2 has a physiological role during embryo implantation, especially in trophoblast invasion. We examined the spatio-temporal expression of Smurf2 in human placental villi and the function of Smurf2 in trophoblast cell migration and invasion in a model system involving a human extravillous trophoblast cell line, HTR-8/SVneo. Results from RT-PCR and immunohistochemical studies showed that expression of Smurf2 in placental villi was the highest during the first trimester and decreased as the pregnancy progressed. Overexpression of Smurf2 in HTR-8/SVneo cells reduced TGF-beta type I receptor levels, and enhanced cell migration and invasion. Conversely, RNA interference-mediated downregulation of Smurf2 resulted in a significant increase in TGF-beta type I receptor protein levels. However, the levels of Smad2, another potential target of Smurf2, remained unchanged. In conclusion, the present study suggests that Smurf2 promotes trophoblast cell migration and invasion, and this function may involve downregulation of TGF-beta type I receptor.

The expression and activity of MMPs are increased in residual tumor tissues after the termination of immunotherapy

To investigate the invasive ability of the residual tumor cells after immunotherapy and explore the feasible approach suppressing the invasion, mice were inoculated with B16 cells, and then treated by gene therapy with p4-1BBL/psPD-1 or IFN-gamma. The production and activities of MMP-9 and MMP-2 in residual tumor tissues were analyzed with gelatin zymography 1 day and 7 days after the termination of the immunotherapy. The production of MMP-9 and MMP-2 by B16 cells treated with IFN-gamma was also analyzed. IFN-gamma-treated B16 cells were inoculated to mice via subcutaneous injection. The invasion of tumor to muscular tissue was analyzed. Gene therapy with CH50 was used to suppress the invasive growth of tumor. The results showed that the expression and the activities of MMP-9 and MMP-2 were significantly increased 7 days after the end of immunotherapy. The response of tumor cells to ECM molecules was intensified after the removal of IFN-gamma, resulting in significant increase of both the production and activities of MMP-9 and MMP-2, and the increased invasion of tumor. Gene therapy with CH50 effectively suppressed the invasive growth of tumor. It is concluded that the termination of immunotherapy may result in a higher metastatic potential of residual tumor cells. Suppressing tumor invasion by suitable treatment will improve the efficacy of immunotherapy.

The granulocyte colony stimulating factor (G-CSF) activates Jak/STAT and MAPK pathways in a trophoblastic cell line

Granulocyte colony-stimulating factor receptor (G-CSFR) has been found in placenta tissues, although its functional role has not yet been defined. In order to explore the molecular pathways induced by G-CSF in this tissue, we first reveal the presence of G-CSFR in the JEG-3 human trophoblastic cell line and then examined the phosphorylation of Janus tyrosine kinases (Jak), signal transducers and activators of transcription (STAT) proteins and mitogen-activated protein kinases (MAPK) after G-CSF binding to receptors. We showed that Jak1, Jak2, Tyk2, and STAT3 were phosphorylated after incubation with G-CSF. Phosphorylation of p38 and p44/42 MAPK was also activated by G-CSF, and specifically blocked in the presence of the corresponding inhibitors. Similar intracellular pathways were induced by G-CSF in a myeloid leukemia NFS-60 cell line that was studied in parallel. Conversely to cytokine action in myeloid cells, G-CSF did not induce a proliferative response in JEG-3 cells. When the effect of G-CSF on cellular viability was evaluated, cytokine-stimulated JEG-3 cells were protected from foetal serum starvation. In addition, when JEG-3 cells deprived of serum were incubated at different times in the presence of G-CSF, a progressive decrease in the percentage of hypodiploid cells was observed. In summary, we identified the molecular pathways activated after G-CSF binding to trophoblastic cell receptors and showed that G-CSF behaved as a protective cytokine, which supports JEG-3 cells survival.

Dickkopf-1 secreted by decidual cells promotes trophoblast cell invasion during murine placentation

Dickkopf-1 (Dkk1) is one of the secreted antagonists in the canonical Wnt signaling pathway. It plays important roles in diverse developmental processes. However, the role of Dkk1 in trophoblast cell invasion during placentation remains unclear. In this study, we found that Dkk1 was mainly expressed in maternal decidual tissue but trivially in ectoplacental cones (EPCs) in day 8 post coitum (p.c.) pregnant mouse uterus and that the efficiency of EPC attachment and outgrowth was increased when co-cultured with decidual cells, which secreted Dkk1, and this enhancement was abolished by pretreating decidual cells with Dkk1 blocking antibody before co-culture experiment. This indicates that Dkk1 secreted by decidual cells plays an important role in trophoblast cell invasion. Indeed, when recombinant mouse Dkk1 was added to EPCs in vitro, the efficiency of attachment and outgrowth was increased. Migration of EPCs toward the decidua was retarded when antisense Dkk1 oligonucleotide (ODN) was administered via intrauterine injection in vivo. Furthermore, the active beta-catenin nuclear location was lost when we treated cultured EPCs with recombinant mouse Dkk1, and the efficiency of EPCs attachment and outgrowth was obviously increased when we treated cultured EPCs with antisense beta-catenin ODN. Taken together, Dkk1 secreted by decidual cells may induce trophoblast cell invasion in the mouse and beta-catenin may be involved in such functions of Dkk1.

Cytokines: Important for implantation?

PROBLEM

Cytokines are obviously very important in an established pregnancy, but what about human embryo implantation?

METHODS

Literature review.

RESULTS

We first discuss the necessity and limits of animal models, and then review the few cytokines which have been demonstrated by knock-out methods to be absolutely necessary for embryo implantation using in animal models. We then review what is known or discussed about the role of other cytokines as deduced from quantitative and/or qualitative dysregulation in animals and in humans.

CONCLUSIONS

Cytokines are indeed involved in implantation as they are in ongoing pregnancy and delivery. Relevance to infertility and recurrent pregnancy loss is discussed.

[Physiology of implantation]

This article explains why we have had to come to a central role for innate immunity rather than the threat of maternal rejection of the foetal allograft. We encompass briefly the role of inflammation in implantation, not only for invasion adhesion, but also to prepare future "tolerance". In this context, we envisage the role of TWEAK and complement.

Preeclampsia: new insights

PURPOSE OF REVIEW

Preeclampsia is a disorder of gestation characterized by hypertension and proteinuria and can be complicated by eclamptic seizures. This review describes recent advances in the role of the renin-angiotensin system and angiogenic and anti-angiogenic factors of placental origin in its pathogenesis.

RECENT FINDINGS

Deficient uteroplacental perfusion has been recognized to be a feature in all preeclampsia syndromes. Increased renin expression observed in humans and animal models supports the concept that activation of the decidual renin-angiotensin system may mediate the pathogenesis of preeclampsia. Novel angiotensin II-related biomolecular mechanisms, angiotensin II type 1-B2 receptor heterodimerization and autoantibody against angiotensin II type 1 have recently been described in preeclampsia. New evidence suggests that vascular endothelial growth factor and its receptors, antagonists, and reduced placental growth factor may play a role in the development of proteinuria and other renal injury-mediated manifestations in preeclampsia.

SUMMARY

Vascular maladaptation, with increased vasomotor tone, endothelial dysfunction, increased sensitivity to angiotensin II and norepinephrine, and multiorgan dysfunction seen in preeclampsia, may be explained by angiotensin II-mediated mechanisms. Future investigations need to define the mechanism of activation of the decidual renin-angiotensin system and the release of placental factors in the pathogenesis of preeclampsia.

Cyclosporin a improves pregnancy outcome by promoting functions of trophoblasts and inducing maternal tolerance to the allogeneic fetus in abortion-prone matings in the mouse

The embryo expresses paternal antigens foreign to the mother, and therefore has been viewed as a natural allograft. Cyclosporin A (CsA) is an immunosuppressant for preventing allograft rejection. Little is known, however, about the modulating effect of CsA on the materno-fetal relationship. In this study, pregnant CBA/J female mice mated with DBA/2 or BALB/c male mice as abortion-prone and normal pregnancy matings were administered, respectively, with CsA at Day 4 of gestation. We demonstrated that the administration of CsA at the window of implantation resulted in maternal T-cell tolerance to paternal antigen, and it improved pregnancy outcome in the CBA/J multiply sign in box DBA/2 abortion-prone matings. CsA administration enhanced Th2 and reduced Th1 cytokine production at the materno-fetal interface, and it expanded peripheral CD4(+)CD25(+) FOXP3(+) regulatory T cells in abortion-prone matings, implying development of Th2 bias and regulatory T cells. On the other hand, we observed that treatment with CsA led to enhanced growth and invasiveness of trophoblasts in the abortion-prone matings. Together, these findings indicate that CsA in lower dosages can induce materno-fetal tolerance and improve the biologic functions of trophoblast cells in the abortion-prone matings, leading to a successful pregnancy, which is useful in clinical therapeutics for spontaneous pregnancy wastage and other pregnancy complications.

Interferon-gamma inhibits extravillous trophoblast cell invasion by a mechanism that involves both changes in apoptosis and protease levels

BACKGROUND

Extravillous trophoblast cell (EVT) invasion of decidua and inner third of the myometrium is critical for a successful pregnancy. Many decidual factors are likely to play a role in regulating this process, including uterine natural killer (uNK) cell-derived cytokines.

HYPOTHESES

1) uNK cells are a major source of IFN gamma (IFN-gamma) and 2) IFN-gamma inhibits EVT invasion via an increase in EVT apoptosis and/or a decrease in active protease levels.

METHODS

Total decidual and uNK cells from 8-10 wk and 12-14 wk gestational age were cultured. IFN-gamma mRNA (real-time RT-polymerase chain reaction) and protein levels (FastQuant multicytokine analysis) were determined. EVT invasion in the presence of IFN-gamma or anti-IFN-gamma-neutralizing antibodies was assessed. Trophoblast apoptosis and proliferation was assessed in explants by immunohistochemistry for M30 and Ki67. Substrate zymography was performed to determine levels of secreted MMP2, MMP9, and uPA.

RESULTS

mRNA and protein for IFN-gamma was detected in both total decidual and uNK cell fractions. Trophoblast invasion was inhibited by IFN-gamma. The level of M30-positive EVT was increased in the presence of IFN-gamma whereas levels of secreted MMP2 were decreased.

CONCLUSIONS

uNK cells are a source of IFN-gamma within early human pregnancy decidua. Mechanisms of IFN-gamma inhibition of EVT invasion include both increased EVT apoptosis and reduced levels of active proteases.

Dickkopf-1 induced apoptosis in human placental choriocarcinoma is independent of canonical Wnt signaling

Placental choriocarcinoma, a reproductive system carcinoma in women, has about 0.81% occurrence frequency in China, which leads to over 90% lethality due to indistinct pathogenesis and the absence of efficient therapeutic treatment. In the present study, using immunostaining and reverse transcription PCR, we reported that Dickkopf-1 (Dkk-1) is prominently expressed in human cytotrophoblast (CTB) cell, but absent in the human placental choriocarcinoma cell line JAR and JEG3, implicating an unknown correlation between Dkk-1 and carcinogenesis of placental choriocarcinoma. Further, through exogenous introduction of Dkk-1, we found repressed proliferation in JAR and JEG3, induced apoptosis in JAR, and discovered significant tumor suppression effects of Dkk-1 in placental choriocarcinoma. Moreover we found that this function of Dkk-1 is achieved through c-Jun N-terminal kinase (JNK), whereas the canonical Wnt pathway may not have a great role. This discovery is not symphonic to previous functional understanding of Dkk-1, a canonical Wnt signaling antagonist. Together, our data indicate the possible correlation between Dkk-1 and human placental choriocarcinoma and suggest potential applications of Dkk-1 in treatment of human placental choriocarcinomas.

Effect of low oxygen concentrations on trophoblast-like cell line invasion

The applicability of trophoblast-like cell lines to the study of trophoblast function has been widely debated. The present study investigated the effect of oxygen on the invasiveness, apoptosis, proliferation and secreted proteases of four different trophoblast cell lines; HTR-8/SVneo, SGHPL-4, JEG3 and JAR. All experiments were performed at 20% and 3% oxygen for 24, 48 and 72h. Immunostaining for integrins alpha1, alpha6 and beta3, cytokeratin 7 and HLA-G was used to determine the phenotype of the different cell lines. Invasion was assessed using the Matrigel invasion assay. Immunostaining for M30 and Ki67 determined levels of apoptosis and proliferation, respectively. Gelatin and casein/plasminogen zymography were performed on conditioned media to determine levels of secreted matrix metalloproteinase (MMP) 2 and MMP9 and urokinase plasminogen activator (uPA), respectively. None of the cell lines immunostained for all markers normally expressed by extravillous trophoblast cells. Invasiveness of HTR-8/SVneo and JEG3 cells cultured in 3% oxygen was increased after 24h but was inhibited by 72h in culture. Invasion of SGHPL-4 cells was inhibited after culture in 3% oxygen for 24h. Invasion by JAR cells was not affected by changes in oxygen concentration. The different cell lines also displayed different responses to culture period in 3% oxygen with respect to apoptosis, proliferation and secreted proteases. Care should be taken before results obtained using cell lines as a model for EVT are extrapolated to extravillous trophoblast cell behaviour in vivo.