Search Results (73)

Defective placentation is a recognized etiology for several gestational complications that include early pregnancy loss, preeclampsia, and intrauterine growth restriction. Sustained viability, migration, and invasion are essential cellular properties for embryonic extravillous trophoblasts to execute their roles in placental development and function, while derailment of these cellular processes is linked to placental disorders. Although the cellular functions of extravillous trophoblasts are well recognized, our understanding of the pivotal molecular determinants of these functions is incomplete. Using the HTR-8/SVneo immortalized human extravillous trophoblast cell line, we report that steroid receptor coactivator-2 (SRC-2), a coregulator of transcription factor-mediated gene expression, is essential for extravillous trophoblast cell viability, motility, and invasion. Genome-scale transcriptomics identified an SRC-2-dependent transcriptome in HTR-8/SVneo cells that encodes a diverse spectrum of proteins involved in placental tissue development and function. Underscoring the utility of this transcriptomic dataset, we demonstrate that WNT family member 9A (WNT 9A) is not only regulated by SRC-2 but is also crucial for maintaining many of the above SRC-2-dependent cellular functions of human extravillous trophoblasts. Full article

Recurrent pregnancy loss (RPL) is a multifactorial condition affecting 1–5% of couples, often with unclear etiology. Idiopathic pregnancy losses (iPLs) are particularly challenging due to unknown molecular mechanisms. This study investigates the transcriptomic profiles of first-trimester products of conception (POC) from iPLs to uncover underlying molecular pathways. We performed RNA-sequencing on nine POC samples, identifying two distinct clusters enriched in trophoblast and decidual cells. Deconvolution analysis revealed reduced syncytiotrophoblast (STB) cells, with increased cytotrophoblast (CTB) and extravillous trophoblast (EVT) cells in iPLs. Gene Set Enrichment Analysis highlighted immune pathways enrichment in both villous trophoblasts and decidua. Gene ontology (GO) analysis of downregulated genes implicated hormonal and endocrine processes, consistent with STB reduction, while upregulated genes were associated with MHC protein complex and immune system processes, aligning with EVT increases. Histological analysis showed chronic histiocytic intervillositis (CHI) in iPL samples, supporting maternal immune dysregulation in unexplained RPL. Together, transcriptomic and histological analyses indicate that immune signaling dysregulation and impaired trophoblast differentiation may underlie unexplained iPLs. These findings bridge molecular and histopathological evidence, underscoring the interplay between trophoblast dysfunction and immune imbalance. Our results provide insights into iPL pathogenesis, highlighting potential biomarkers that may contribute to improved diagnosis and future research. Full article

The phenotype of human placental extravillous trophoblast (EVT) at the end of pregnancy reflects both differentiation from villous cytotrophoblast (CTB) and later gestational changes, including loss of proliferative and invasive capacity. Invasion abnormalities are central to major obstetric pathologies, including placenta accreta spectrum, early onset preeclampsia, and fetal growth restriction. Characterization of the normal differentiation processes is, thus, essential for the analysis of these pathologies. Our gene expression analysis, employing purified human CTB and EVT cells, demonstrates a mechanism similar to the epithelial–mesenchymal transition (EMT), which underlies CTB–EVT differentiation. In parallel, DNA methylation profiling shows that CTB cells, already hypomethylated relative to non-trophoblast cell lineages, show further genome-wide hypomethylation in the transition to EVT. A small subgroup of genes undergoes gains of methylation (GOM), associated with differential gene expression (DE). Prominent in this GOM-DE group are genes involved in epithelial–mesenchymal plasticity (EMP). An exemplar is the transcription factor RUNX1, for which we demonstrate a functional role in regulating the migratory and invasive capacities of trophoblast cells. This analysis highlights epigenetically regulated genes acting to underpin the epithelial–mesenchymal plasticity characteristic of human trophoblast differentiation. Identification of these elements provides important information for the obstetric disorders in which these processes are dysregulated. Full article

Background: Preeclampsia (PE) is a deadly obstetric complication in pregnant women leading to escalated rates of maternal and fetal mortality. Current research indicates that inadequate invasion of extravillous trophoblasts (EVTs) is a primary factor associated with the pathogenesis of PE. Insulin-like growth factor binding protein 2 (IGFBP2) plays a significant role in promoting cell migration, invasion, and angiogenesis. Researchers aim to investigate the clinical significance and elucidate the molecular mechanisms of IGFBP2 in the pathogenesis of preeclampsia. Methods: This study included 40 pregnant women categorized into 20 PE patients and 20 healthy controls. Expression levels of the mRNA were quantified using real-time quantitative polymerase chain reaction (qRT-PCR), and protein levels were assessed through Western blotting and immunofluorescence techniques. Moreover, the gain- and loss-of-function assays were conducted in human trophoblast cell line HTR-8/SVneo, and cellular models exhibiting overexpression and the knockdown of IGFBP2 were established. The proliferation, migration, and invasion of HTR-8/Svneo cells were determined using CCK8, wound-healing, and transwell assays, respectively. Results: The IGFBP2 was significantly downregulated, and the EMT was suppressed in the placental tissues of the PE patients. Functional experiments demonstrated that IGFBP2 enhanced the proliferation, invasion, and EMT of trophoblast cells activated through the PI3K/AKT signaling pathway. Conclusion: Our findings indicated that IGFBP2 enhances the proliferation, invasion, and EMT of trophoblast cells by activating the PI3K/AKT signaling pathway, serving as a potential therapeutic target in PE patients. Full article

To clarify the physiological importance of the tryptophan catabolizing enzyme, indoleamine 2,3-dioxygenase, in human pregnancy, we have studied how the expression of this enzyme controls extravillous cytotrophoblast invasion into the decidua. We have generated an Ishikawa cell line stably transfected with a plasmid encoding indoleamine 2,3-dioxygenase under the control of a tetracycline inducible promoter. Using this Ishikawa cell line and extravillous cytotrophoblast cell line, HTR-8/SVneo, we developed a quantitative in vitro trophoblast invasion assay. When trophoblast cells were cultured on a layer of Ishikawa cells expressing indoleamine 2,3-dioxygenase, tryptophan degradation was enhanced and trophoblast cell invasion was suppressed. These findings suggest that indoleamine 2,3-dioxygenase expressed in the decidua may play a role in regulating trophoblast invasion. Full article

Epidural-related maternal fever (ERMF) occurs with significant incidence in women receiving local anesthetics such as ropivacaine via epidural catheter for pain relief during labor. The causal mechanism behind this phenomenon is still not fully resolved, but evidence suggests that these anesthetics cause sterile inflammation. In this observational study, we investigated a possible contributory role of the dual-specificity phosphatase-9 (DUSP9) controlling the activity of mitogen-activated protein kinases (MAPK), and also PH-domain and Leucine-rich repeat phosphatase (PHLPP) regulating AKT kinases. The data show that ropivacaine differentially affects the expression of these phosphatases in distinct cell types of the umbilical cord and placenta. The gene expression of DUSP9 was almost completely switched off in the presence of ropivacaine in HUVECs and extravillous trophoblasts for up to 6 h, while the expression of PHLPP1 was upregulated in HUVECs and syncytiotrophoblasts. Extravillous trophoblasts were identified as a source of pro-inflammatory mediators and regulatory miRNAs in response to ropivacaine. Placentae at term exhibited a distinct DUSP9 expression pattern, whether the patients belonged to the control group or received epidural analgesia with or without elevated body temperature. The observed data imply that ropivacaine induces complex effects on the MAPK and AKT pathways at the feto–maternal interface, which contribute to the ERMF phenomenon. Full article

PLAC8, expressed by interstitial extravillous trophoblasts (iEVTs), plays a crucial role in trophoblast invasion, differentiation, and immunotolerance. Its dysregulation may contribute to pregnancy complications, such as preeclampsia. This study investigates the role of PLAC8 in trophoblast invasiveness and endothelial-like differentiation under different oxygen tensions. Swan-71 cells were transiently transfected with PLAC8 overexpression or knockdown plasmids. Invasion was assessed using Matrigel-coated transwells, endothelial-like differentiation through tube formation assays, and vasculogenic marker expression (VEGF, PGF, ANGPT2) by RT-PCR. Hypoxia experiments were performed at different oxygen conditions. PLAC8 overexpression enhanced trophoblast invasion but reduced endothelial-like differentiation, downregulating VEGF and PGF while upregulating ANGPT2. Hypoxia increased PLAC8 expression, indicating oxygen tension as a regulatory factor. PLAC8 manipulation did not affect cell viability. PLAC8 modulates trophoblast behavior by promoting invasion while inhibiting endothelial-like differentiation. Its regulation of vasculogenic and angiogenic factors suggests a critical role in placental homeostasis and potential relevance to pregnancy disorders, such as preeclampsia. Full article

Maternal–fetal tolerance mechanisms are crucial during human pregnancy to prevent the immune rejection of the embryo. A well-known mechanism blocking NK-cell cytotoxicity is the interaction of their inhibitory killer-cell immunoglobulin-like receptors (iKIR) with HLA-C molecules on the target cells. In this study, we aimed to investigate the expression of iKIRs (KIR2DL1 and KIR2DL2/3) on the matched decidual and peripheral γδT cells and the localization of HLA-C ligands throughout human pregnancy. The degranulation of γδT cells of pregnant and non-pregnant women in the presence of trophoblast cells was evaluated as well. Our results showed a higher proportion of iKIR-positive γδT cells at the maternal–fetal interface early in human pregnancy compared to the paired blood of pregnant women and full-term pregnancy decidua. In accordance, HLA-C was intensively expressed by the intermediate cytotrophoblasts and decidua-invading extravillous trophoblasts (EVTs) in early but not late pregnancy. Decidual γδT cells during early pregnancy showed higher spontaneous degranulation compared to their blood pairs, but neither decidual nor peripheral γδ T cells increased their degranulation in the presence of Sw71 EVT-like cells. The latter were unable to suppress the higher cytotoxicity of γδT cells, suggesting a complex regulatory landscape beyond NK-like activity inhibition. Full article

Molybdenum is an essential trace element sourced during pregnancy from the maternal diet. Studies regarding molybdenum have primarily focused on overexposure in animal and cell culture studies. The effects of molybdenum supplementation on placental function are unknown. An immortalised trophoblast cell line was used to examine the placental cellular response to molybdenum in its bioavailable form as molybdate. Cells of the extravillous trophoblast first-trimester cell line HTR8-SVneo were cultured in complete cell media in the presence of 10 nM to 1 mM of ammonium molybdate or sodium molybdate. Following the addition of the molybdate salts, cell growth, viability, and several gene pathways were monitored. Sodium molybdate salt in doses from 10 nM to 1 mM did not affect cell growth or viability. Exposure to ammonium molybdate at a 1 mM concentration significantly decreased cell growth and viability (p < 0.05). Gene pathways involving molybdoenzyme expression, molybdenum cofactor synthesis, antioxidant response, and angiogenesis were affected following supplementation, although these effects differed depending on the dose and molybdate salt utilised. Molybdoenzyme activity was not affected by supplementation in a dose-dependent manner. The results indicate sodium molybdate is a more appropriate salt to use in vitro, as ammonium molybdate exposure reduced cell viability and growth and downregulated the expression of antioxidant genes NFE2L2 (p < 0.01), SOD1 (p < 0.001) and SOD2 (p < 0.001), suggestive of an inflammatory response. Sodium molybdate affected gene, protein, and activity levels of molybdoenzyme, antioxidant, and angiogenic molecules in vitro. This work demonstrates that sodium molybdate supplementation has pleiotropic effects in vitro and is well tolerated by placental cells at a range of nanomolar and micromolar concentrations. Full article

Elevated glucose levels at the fetal–maternal interface are associated with placental trophoblast dysfunction and increased incidence of pregnancy complications. Trophoblast cells predominantly utilize glucose as an energy source, metabolizing it through glycolysis in the cytoplasm and oxidative respiration in the mitochondria to produce ATP. The TGFβ1/SMAD2 signaling pathway and the transcription factors PPARγ, HIF1α, and AMPK are key regulators of cell metabolism and are known to play critical roles in extravillous trophoblast cell differentiation and function. While HIF1α promotes glycolysis over mitochondrial respiration, PPARγ and AMPK encourage the opposite. However, the interplay between TGFβ1 and these energy-sensing regulators in trophoblast cell glucose metabolism remains unclear. This study aimed to investigate whether and how TGFβ1 regulates energy metabolism in trophoblast cells exposed to normal and high glucose conditions. The trophoblast JEG-3 cells were incubated in normal (5 mM) and high (25 mM) glucose conditions for 24 h in the absence and the presence of TGFβ1. The protein expression levels of phosphor (p)-SMAD2, GLUT1/3, HIF1α, PPARγ, p-AMPK, and specific OXPHOS protein subunits were determined by western blotting, and ATP and lactate production by bioluminescent assay kits. JEG-3 cells exposed to 25 mM glucose decreased ATP production but did not affect lactate production. These changes led to a reduction in the expression levels of GLUT1/3, mitochondrial respiratory chain proteins, and PPARγ, coinciding with an increase in HIF1α expression. Conversely, TGFβ1 treatment at 25 mM glucose reduced HIF1α expression while enhancing the expression levels of GLUT1/3, PPARγ, p-AMPK, and mitochondrial respiratory chain proteins, thereby rejuvenating ATP production. Our findings reveal that high glucose conditions disrupt cellular glucose metabolism in trophoblast cells by perturbing mitochondrial oxidative respiration and decreasing ATP production. Treatment with TGFβ1 appears to counteract this trend, probably by enhancing both glycolytic and mitochondrial metabolism, suggesting a potential regulatory role of TGFβ1 in placental trophoblast cell glucose metabolism. Full article

Placentation disorders, including severe preeclampsia and fetal growth restriction, have their origins in early pregnancy, whereas symptoms typically present later on. To investigate the pathogenesis of these diseases, there is a need for a reliable in vitro model system of early placenta development with known pregnancy outcomes. Therefore, we optimized the generation of human induced trophoblast stem cells (iTSCs) from term umbilical cord, enabling non-invasive collection of patient-derived material immediately after birth. Using a direct reprogramming approach previously described for dermal fibroblasts, we investigated the effects of three supplements (A-485, BMP4, and EPZ-6438) to assess their potential to enhance iTSC induction. The generated iTSCs fulfilled the criteria for bona fide first-trimester trophoblasts and exhibited key functional capacities, including long-term self-renewal, differentiation into hormone-producing syncytiotrophoblasts and invasive extravillous trophoblasts, and the formation of organoids. Furthermore, transcriptomic analysis revealed high similarity between the generated iTSCs and trophoblast stem cells derived from first-trimester placental tissue. The supplements did not improve the generation of iTSCs. In conclusion, we successfully generated bona fide iTSCs from term umbilical cord using a direct reprogramming approach, providing a robust and clinically relevant model to study early placentation mechanisms in patient-derived trophoblasts. Full article

Recurrent pregnancy loss (RPL) is a complex early pregnancy complication affecting 1–2% of couples and is often linked to immune dysfunction. Aberrations in T and B cell subpopulations, as well as natural killer (NK) cell activity, are particularly influential, with studies showing that abnormal NK cell activation and imbalances in T and B cell subtypes contribute to immune-mediated miscarriage risk. Successful pregnancy requires a tightly regulated balance between pro-inflammatory and anti-inflammatory immune responses. In the early stages, inflammation supports processes such as trophoblast invasion and spiral artery remodeling, but this must be tempered to prevent immune rejection of the fetus. In this review, we explore the underlying immune mechanisms of RPL, focusing on how dysregulated T, B, and NK cell function disrupts maternal tolerance. Specifically, we discuss the essential role of uterine NK cells in the early stages of vascular remodeling in the decidua and regulate the depth of invasion by extravillous trophoblasts. Furthermore, we focus on the delicate Treg dynamics that enable the maintenance of optimal immune homeostasis, where the balance, and not only the quantity of Tregs, is crucial for fostering maternal–fetal tolerance. Other T cell subpopulations, such as Th1, Th2, and Th17 cells, also contribute to immune imbalance, with Th1 and Th17 cells promoting inflammation and potentially harming fetal tolerance, while Th2 cells support immune tolerance. Finally, we show how changes in B cell subpopulations and their functions have been associated with adverse pregnancy outcomes. We further discuss current therapeutic strategies aimed at correcting these immune imbalances, including intravenous immunoglobulin (IVIg), glucocorticoids, and TNF-α inhibitors, examining their efficacy, challenges, and potential side effects. By highlighting both the therapeutic benefits and limitations of these interventions, we aim to offer a balanced perspective on clinical applications for women facing immune-related causes of RPL. Full article

We have previously reported that the calcineurin inhibitor macrolide immunosuppressant Tacrolimus (TAC, FK506) can promote the migration and invasion of the human-derived extravillous trophoblast cells conducive to preventing implantation failure in immune-complicated gestations manifesting recurrent implantation failure. Although the exact mode of action of TAC in promoting implantation has yet to be elucidated, the integral association of its binding protein FKBP12 with the inositol triphosphate receptor (IP3R) regulated intracellular calcium [Ca²⁺]i channels in the endoplasmic reticulum (ER), suggesting that TAC can mediate its action through ER release of [Ca²⁺]i. Using the immortalized human-derived first-trimester extravillous trophoblast cells HTR8/SVneo, our data indicated that TAC can increase [Ca²⁺]I, as measured by fluorescent live-cell imaging using Fluo-4. Concomitantly, the treatment of HTR8/SVneo with TAC resulted in a major dynamic reorganization in the actin cytoskeleton, favoring a predominant distribution of cortical F-actin networks in these trophoblasts. Notably, the findings that TAC was unable to recover [Ca²⁺]i in the presence of the IP3R inhibitor 2-APB indicate that this receptor may play a crucial role in the mechanism of action of TAC. Taken together, our results suggest that TAC has the potential to influence trophoblast migration through downstream [Ca²⁺]i-mediated intracellular events and mechanisms involved in trophoblast migration, such as F-actin redistribution. Further research into the mono-therapeutic use of TAC in promoting trophoblast growth and differentiation in clinical settings of assisted reproduction is warranted. Full article

Galectins are a class of lectins that are extensively expressed in all organisms. Galectins are involved in a range of functions, including early development, tissue regeneration, cancer and inflammation. It has been shown that galectin-8 is expressed in the villous and extravillous trophoblast (EVT) cells of the human placenta; however, its physiological role in pregnancy establishment has not been elucidated. Taking these factors into account, we investigated the functional role of galectin-8 in HTR-8/SVneo cells—a human EVT cell line—and human primary cytotrophoblast cells isolated from a first-trimester placenta. We analyzed the effects of recombinant human galectin-8 (rh galectin-8) on the adhesion, migration and invasion of HTR-8/SVneo cells. We used qPCR, cell-based ELISA (cELISA) and gelatin zymography to study the effects of galectin-8 on mediators of these processes, such as integrin subunits alpha-1 and beta-1 and matrix metalloproteinases (MMPs)-2 and -9, on the mRNA and protein levels. Further, we studied the effects of galectin-8 on primary cytotrophoblast cells’ invasion. Galectin-8 stimulated the adhesion, migration and invasion of HTR-8/SVneo cells, as well as the invasion of primary cytotrophoblasts. In addition, the MMP-2 and -9 levels were increased, while the expression of integrins alpha-1 and beta-1 was not affected. Galectin-8 has the ability to positively affect EVTs’ invasion, so it can be considered a significant factor in the trophoblast cell invasion process. Full article

A key aspect of preeclampsia pathophysiology is the reduced invasiveness of trophoblasts and the impairment of spiral artery remodelling. Understanding the causes of altered trophoblast function is critical to understand the development of preeclampsia. B7-H4, a checkpoint molecule, controls a wide range of processes, including T-cell activation, cytokine release, and tumour progression. Our previous findings indicated that B7-H4 levels are elevated in both maternal blood and placental villous tissue during the early stages of preeclampsia. Here, we investigated the function of B7-H4 in trophoblast physiology. Recombinant B7-H4 protein was used to treat human SGHPL-5 extravillous trophoblast cells. Biological functions were investigated using MTT, wound healing, and transwell assays. Signalling pathways were analysed by immunoblotting and immunofluorescence. The functionality of B7-H4 was further confirmed by immunoblotting and immunohistochemical analysis in placental tissues from control and preeclamptic patients following therapeutic plasma exchange (TPE) or standard of care treatment. This study showed that B7-H4 inhibited the proliferation, migration, and invasion capacities of SGHPL-5 extravillous cells while promoting apoptosis by downregulating the PI3K/Akt/STAT3 signalling pathway. These results were consistently confirmed in placental tissues from preterm controls compared to early-onset preeclamptic placental tissues from patients treated with standard of care or TPE treatment. B7-H4 may play a role in the development of preeclampsia by inhibiting essential functions of extravillous trophoblast cells during placental development. One possible mechanism by which TPE improves pregnancy outcomes in preeclampsia is through the elimination of B7-H4 amongst other factors. Full article