Trophoblast lineage-specific differentiation and associated alterations in preeclampsia and fetal growth restriction

TFEB safeguards trophoblast syncytialization in humans and mice

Nutrient sensing and adaptation in the placenta are essential for pregnancy viability and proper fetal growth. Our recent study demonstrated that the placenta adapts to nutrient insufficiency through mechanistic target of rapamycin (mTOR) inhibition-mediated trophoblast differentiation toward syncytiotrophoblasts (STBs), a highly specialized multinucleated trophoblast subtype mediating extensive maternal-fetal interactions. However, the underlying mechanism remains elusive. Here, we unravel the indispensable role of the mTORC1 downstream transcriptional factor TFEB in STB formation both in vitro and in vivo. TFEB deficiency significantly impaired STB differentiation in human trophoblasts and placenta organoids. Consistently, systemic or trophoblast-specific deletion of Tfeb compromised STB formation and placental vascular construction, leading to severe embryonic lethality. Mechanistically, TFEB conferred direct transcriptional activation of the fusogen ERVFRD-1 in human trophoblasts and thereby promoted STB formation, independent of its canonical function as a master regulator of the autophagy-lysosomal pathway. Moreover, we demonstrated that TFEB directed the trophoblast syncytialization response driven by mTOR complex 1 (mTORC1) signaling. TFEB expression positively correlated with the reinforced trophoblast syncytialization in human fetal growth-restricted placentas exhibiting suppressed mTORC1 activity. Our findings substantiate that the TFEB-fusogen axis ensures proper STB formation during placenta development and under nutrient stress, shedding light on TFEB as a mechanistic link between nutrient-sensing machinery and trophoblast differentiation.

Identification of HTRA4 as a Transcriptional Target of p63 in Trophoblast

The placenta plays a crucial role in pregnancy success. ΔNp63α (p63), a transcription factor from the TP53 family, is highly expressed in villous cytotrophoblasts (CTBs), the epithelial stem cells of the human placenta, and is involved in CTB maintenance and differentiation. We examined the mechanisms of action of p63 by identifying its downstream targets. Gene expression changes were evaluated following overexpression and knockdown of p63 in the JEG3 choriocarcinoma cell line, using microarray-based RNA profiling. High-temperature requirement A4 (HTRA4), a placenta-specific serine protease involved in trophoblast differentiation and altered in preeclampsia, was identified as a gene reciprocally regulated by p63, and its expression was characterized in primary human placental tissues by RNA-sequencing and in situ hybridization. Potential p63 DNA-binding motifs were identified in the HTRA4 promoter, and p63 occupancy at some of these sites was confirmed using chromatin immunoprecipitation, followed by quantitative PCR in both JEG3 and trophoblast stem cells. These data begin to identify members of the transcriptional network downstream of p63, thus laying the groundwork for probing mechanisms by which this important transcription factor regulates trophoblast stemness and differentiation.

Effect of Granzyme K, FasL and Interferon-γ Expression in Placentas with Preeclampsia

This study aimed to investigate the cytotoxic activity of decidual lymphocytes and the mRNA/protein expression of cytotoxic proteins in various cell types in the context of preeclampsia (PE) compared to those of healthy pregnancies. We analyzed fresh decidua basalis tissue and tissue embedded in paraffin (FFPE) from PE pregnancies (n = 15) and compared them with those of healthy pregnancies (n = 15) of the corresponding gestational age. Using double immunofluorescence staining, we observed differences in the intensity and distribution of staining for granzyme K (GZMK) and FasL in extravillous trophoblasts. RT-qPCR analysis of FFPE placental tissue showed that GZMK mRNA expression was statistically higher (p < 0.0001) in PE compared to that of healthy controls. On the contrary, there was a low expression (p < 0.001) of FasL mRNA in PE compared to controls, while there was no statistically significant difference for IFN-γ mRNA between PE and controls. Although the level of cytotoxic activity changed depending on the ratio of effector and target cells, there was no significant difference observed between PE and controls in this in vitro study. In conclusion, in PE, extravillous trophoblasts exhibited increased expression of GZMK and decreased expression of FasL. These changes may contribute to impaired trophoblast invasion. However, these alterations did not appear to affect the cytotoxic properties of decidual lymphocytes. Additionally, the possibility of cell sorter separation of decidual lymphocytes would greatly contribute to a better understanding of single cells' genetic profiles.

Propofol Promoted the Cell Growth and Epithelial Mesenchymal Transformation of the HTR-8/SVneo Cells through Targeting the METTL3 Mediated ZEB2

Preeclampsia (PE) belongs to hypertensive disorder complicating pregnancy, which is a serious obstetric complication. Propofol is a new type of fast and short-acting general anesthetic, which has also been demonstrated to promote the cell growth recently. Therefore, this study was carried out to explore the effects of propofol on the cell growth, migration and invasion in the HTR-8/SVneo cells. The cell biological behaviors were analyzed using CCK-8, EdU, transwell assays. The relationship between METTL3 and ZEB2 was confirmed by RIP assay. Western blot and RT-qPCR assays were carried out to detect the protein and mRNA levels. The results showed that propofol enhanced the cell viability, proliferation, migration and invasion of the HTR-8/SVneo cells. Besides, METTL3 overexpression neutralized the propofol role. Furthermore, METTL3 overexpression elevated the m6A levels of ZEB2 and decreased the mRNA levels and stability of ZEB2. ZEB2 overexpression neutralized the role of METTL3 in the propofol treated HTR-8/SVneo cells. In conclusion, this study demonstrated the effects of propofol on promoting the cell growth, migration and invasion of HTR-8/SVneo cells. Mechanistically, propofol indirectly regulated ZEB2 expression by targeting METTL3 mediated m6A methylation modification.

Bisphenol S moderately decreases the expression of syncytiotrophoblast marker genes and induces apoptosis in human trophoblast lineages

Bisphenol S (BPS) is currently used in the manufacturing of several household equipment such as water pipes and food containers. Hence, its entrance into the human body is almost inevitable. The presence of BPS in body fluids has been reported. However, its potential toxicity, especially on human placenta development and pregnancy progression, has not been explored. In this study, we assessed the impacts of BPS on the self-renewal and differentiation potentials of placental stem cells, also known as trophoblast stem cells (TSCs), by exposing them to three different BPS concentrations during their self-renewal and differentiation into syncytiotrophoblast (ST), extravillous trophoblast (EVT), and trophoblast organoids. Interestingly, BPS treatment did not affect the stemness, cell cycle and proliferation of the TSCs but it induced apoptosis in each trophoblast lineage. BPS altered the expression of several fusion-related genes. However, this alteration did not translate into significant morphological defects in the STs and organoids. Moreover, BPS did not impair the differentiation of TSCs into EVTs. These findings suggest that the presence of BPS at the feto-maternal interface may exaggerate trophoblast apoptosis and moderately inhibit the trophoblast fusion pathway to affect placenta development and pregnancy. Our study offers valuable insights into the potential toxicity of BPS on human placenta development, emphasizing the need for epidemiological assessment of the relationship between maternal serum levels of BPS and pregnancy complications.

Dendritic Cells and the Establishment of Fetomaternal Tolerance for Successful Human Pregnancy

Pregnancy is a remarkable event where the semi-allogeneic fetus develops in the mother's uterus, despite genetic and immunological differences. The antigen handling and processing at the maternal-fetal interface during pregnancy appear to be crucial for the adaptation of the maternal immune system and for tolerance to the developing fetus and placenta. Maternal antigen-presenting cells (APCs), such as macrophages (Mφs) and dendritic cells (DCs), are present at the maternal-fetal interface throughout pregnancy and are believed to play a crucial role in this process. Despite numerous studies focusing on the significance of Mφs, there is limited knowledge regarding the contribution of DCs in fetomaternal tolerance during pregnancy, making it a relatively new and growing field of research. This review focuses on how the behavior of DCs at the maternal-fetal interface adapts to pregnancy's unique demands. Moreover, it discusses how DCs interact with other cells in the decidual leukocyte network to regulate uterine and placental homeostasis and the local maternal immune responses to the fetus. The review particularly examines the different cell lineages of DCs with specific surface markers, which have not been critically reviewed in previous publications. Additionally, it emphasizes the impact that even minor disruptions in DC functions can have on pregnancy-related complications and proposes further research into the potential therapeutic benefits of targeting DCs to manage these complications.

Placental cell conditioned media modifies hematopoietic stem cell transcriptome invitro

INTRODUCTION

Hematopoietic stem cells are cells that differentiate into blood cell types. Although the placenta secretes hormones, proteins and other factors important for maternal/fetal health, cross-talk between placental and hematopoietic stem cells is poorly understood. Moreover, toxicant impacts on placental-hematopoietic stem cell communication is understudied. The goals of this study were to determine if factors secreted from placental cells alter transcriptomic responses in hematopoietic stem cells and if monoethylhexyl phthalate (MEHP), the bioactive metabolite of the pollutant diethylhexyl phthalate, modifies these effects.

METHODS

We used K-562 and BeWo cells as in vitro models of hematopoietic stem cells and placental syncytiotrophoblasts, respectively. We treated K-562 cells with medium conditioned by incubation with BeWo cells, medium conditioned with BeWo cells treated with 10 μM MEHP for 24 h, or controls treated with unconditioned medium. We extracted K-562 cell RNA, performed RNA sequencing, then conducted differential gene expression and pathway analysis.

RESULTS

Relative to controls, K-562 cells treated with BeWo cell conditioned medium differentially expressed 173 genes (FDR<0.05 and fold-change>2.0), including 2.4-fold upregulatation of tropomyosin 4 (TPM4, a cytoskeletal regulator involved in processes such as cell morphology and migration) and 3.3-fold upregulatation of sphingosine-1-phosphate receptor 3 (S1PR3, a mediator of myeloid cell differentiation and inflammatory responses). Upregulated genes were enriched for pathways including stem cell maintenance, cell proliferation and immune processes. Downregulated genes were enriched for terms involved in protein translation and transcriptional regulation. MEHP treatment differentially expressed eight genes (FDR<0.05), including genes involved in lipid metabolism (e.g., Perilipin 2, fold-change: 1.4; Carnitine Palmitoyltransferase 1A, fold-change: 1.4).

DISCUSSION

K-562 cells, a model of hematopoietic stem cells, are responsive to media conditioned by placental cells, potentially impacting pathways like stem cell maintenance.

Cytology Techniques Can Provide Insight into Human Placental Structure Including Syncytiotrophoblast Nuclear Spatial Organisation

The aim of this study was to provide the first systematic description of human placental cytology appearances and to investigate syncytiotrophoblast nuclear organisation patterns using cytology techniques. Term placentas from normal pregnancies were sampled using fine-needle aspiration (FNA) and direct scrapes. Standard histological examination was also performed to exclude pathological changes in the placentas being studied. Both Papanicolaou-stained cytospin preparations and air-dried Giemsa slides from FNA provided high-quality material for cytological assessment with good cellularity. Among the key features of the cytology preparations were villous "microbiopsies" that allowed for the three-dimensional appreciation of villous branching patterns. Cytological appearances, including nuclear characteristics of villous cytotrophoblast and syncytiotrophoblast, were also well demonstrated. In microbiopsies and detached villous trophoblast sheets, complex patterns of syncytiotrophoblast nuclear organisation, not previously described cytologically, were observed, including irregular spacing of nuclei, syncytioplasm windows and linear nuclear arrangements. This study showed that placental cytology (a) provides technically excellent material for cytological evaluation, (b) confirms the presence of complex nuclear organisational patterns in the syncytiotrophoblast by eliminating the possibility of tangential sectioning artefact, (c) provides superior nuclear detail over standard histological sections and (d) may be an untapped research resource for the investigation of normal and pathological processes because of its ability to look at the placenta in a novel way and through its potential for both ex vivo and in vivo placental sampling.

NOTCH3 signalling controls human trophoblast stem cell expansion and differentiation

Failures in growth and differentiation of the early human placenta are associated with severe pregnancy disorders such as pre-eclampsia and fetal growth restriction. However, regulatory mechanisms controlling development of placental epithelial cells, the trophoblasts, remain poorly elucidated. Using trophoblast stem cells (TSCs), trophoblast organoids (TB-ORGs) and primary cytotrophoblasts (CTBs) of early pregnancy, we herein show that autocrine NOTCH3 signalling controls human placental expansion and differentiation. The NOTCH3 receptor was specifically expressed in proliferative CTB progenitors and its active form, the nuclear NOTCH3 intracellular domain (NOTCH3-ICD), interacted with the transcriptional co-activator mastermind-like 1 (MAML1). Doxycycline-inducible expression of dominant-negative MAML1 in TSC lines provoked cell fusion and upregulation of genes specific for multinucleated syncytiotrophoblasts, which are the differentiated hormone-producing cells of the placenta. However, progenitor expansion and markers of trophoblast stemness and proliferation were suppressed. Accordingly, inhibition of NOTCH3 signalling diminished growth of TB-ORGs, whereas overexpression of NOTCH3-ICD in primary CTBs and TSCs showed opposite effects. In conclusion, the data suggest that canonical NOTCH3 signalling plays a key role in human placental development by promoting self-renewal of CTB progenitors.

Adrenomedullin has a pivotal role in trophoblast differentiation: A promising nanotechnology-based therapeutic target for early-onset preeclampsia

Early-onset preeclampsia (EOPE) is a severe pregnancy complication associated with defective trophoblast differentiation and functions at implantation, but manifestation of its phenotypes is in late pregnancy. There is no reliable method for early prediction and treatment of EOPE. Adrenomedullin (ADM) is an abundant placental peptide in early pregnancy. Integrated single-cell sequencing and spatial transcriptomics confirm a high ADM expression in the human villous cytotrophoblast and syncytiotrophoblast. The levels of ADM in chorionic villi and serum were lower in first-trimester pregnant women who later developed EOPE than those with normotensive pregnancy. ADM stimulates differentiation of trophoblast stem cells and trophoblast organoids in vitro. In pregnant mice, placenta-specific ADM suppression led to EOPE-like phenotypes. The EOPE-like phenotypes in a mouse PE model were reduced by a placenta-specific nanoparticle-based forced expression of ADM. Our study reveals the roles of trophoblastic ADM in placental development, EOPE pathogenesis, and its potential clinical uses.

A comprehensive review of human trophoblast fusion models: recent developments and challenges

As an essential component of the maternal-fetal interface, the placental syncytiotrophoblast layer contributes to a successful pregnancy by secreting hormones necessary for pregnancy, transporting nutrients, mediating gas exchange, balancing immune tolerance, and resisting pathogen infection. Notably, the deficiency in mononuclear trophoblast cells fusing into multinucleated syncytiotrophoblast has been linked to adverse pregnancy outcomes, such as preeclampsia, fetal growth restriction, preterm birth, and stillbirth. Despite the availability of many models for the study of trophoblast fusion, there exists a notable disparity from the ideal model, limiting the deeper exploration into the placental development. Here, we reviewed the existing models employed for the investigation of human trophoblast fusion from several aspects, including the development history, latest progress, advantages, disadvantages, scope of application, and challenges. The literature searched covers the monolayer cell lines, primary human trophoblast, placental explants, human trophoblast stem cells, human pluripotent stem cells, three-dimensional cell spheres, organoids, and placenta-on-a-chip from 1938 to 2023. These diverse models have significantly enhanced our comprehension of placental development regulation and the underlying mechanisms of placental-related disorders. Through this review, our objective is to provide readers with a thorough understanding of the existing trophoblast fusion models, making it easier to select most suitable models to address specific experimental requirements or scientific inquiries. Establishment and application of the existing human placental trophoblast fusion models.

The pathogenesis of obstetric APS: a 2023 update

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the persistent presence of antibodies directed against phospholipids and phospholipid-binding proteins that are associated with thrombosis and pregnancy-related morbidity. The latter includes fetal deaths, premature birth and maternal complications. In the early 1990s, a distinct set of autoantibodies, termed collectively antiphospholipid antibodies (aPL), were identified as the causative agents of this disorder. Subsequently histological analyses of the placenta from APS pregnancies revealed various abnormalities, including inflammation at maternal-fetal interface and poor placentation manifested by reduced trophoblast invasion and limited uterine spiral artery remodeling. Further preclinical investigations identified the molecular targets of aPL and the downstream intracellular pathways of key placental cell types. While these discoveries suggest potential therapeutics for this disorder, definitive clinical trials have not been completed. This concise review focuses on the recent developments in the field of basic and translational research pursuing novel mechanisms underlying obstetric APS.

A review of feto-placental vasculature flow modelling

The placenta provides the vital nutrients and removal of waste products required for fetal growth and development. Understanding and quantifying the differences in structure and function between a normally functioning placenta compared to an abnormal placenta is vital to provide insights into the aetiology and treatment options for fetal growth restriction and other placental disorders. Computational modelling of blood flow in the placenta allows a new understanding of the placental circulation to be obtained. This structured review discusses multiple recent methods for placental vascular model development including analysis of the appearance of the placental vasculature and how placental haemodynamics may be simulated at multiple length scales.

Biogenesis and function of exosome lncRNAs and their role in female pathological pregnancy

Preeclampsia, gestational diabetes mellitus, and recurrent spontaneous abortion are common maternal pregnancy complications that seriously endanger women's lives and health, and their occurrence is increasing year after year with a rejuvenation trend. In contrast to biomarkers found freely in tissues or body fluids, exosomes exist in a relatively independent environment and provide a higher level of stability. As backbone molecules, guidance molecules, and signaling molecules in the nucleus, lncRNAs can regulate gene expression. In the cytoplasm, lncRNAs can influence gene expression levels by modifying mRNA stability, acting as competitive endogenous RNAs to bind miRNAs, and so on. Exosomal lncRNAs can exist indefinitely and are important in intercellular communication and signal transduction. Changes in maternal serum exosome lncRNA expression can accurately and timely reflect the progression and regression of pregnancy-related diseases. The purpose of this paper is to provide a reference for clinical research on the pathogenesis, diagnosis, and treatment methods of pregnancy-related diseases by reviewing the role of exosome lncRNAs in female pathological pregnancy and related molecular mechanisms.

Cis P-tau is a central circulating and placental etiologic driver and therapeutic target of preeclampsia

Preeclampsia (PE) is the leading cause of maternal and fetal mortality globally and may trigger dementia later in life in mothers and their offspring. However, the etiological drivers remain elusive. Cis P-tau is an early etiological driver and blood biomarker in pre-clinical Alzheimer's and after vascular or traumatic brain injury, which can be targeted by stereo-specific antibody, with clinical trials ongoing. Here we find significant cis P-tau in the placenta and serum of PE patients, and in primary human trophoblasts exposed to hypoxia or sera from PE patients due to Pin1 inactivation. Depletion of cis P-tau from PE patient sera by the antibody prevents their ability to disrupt trophoblast invasion and endovascular activity and to cause the PE-like pathological and clinical features in pregnant humanized tau mice. Our studies uncover that cis P-tau is a central circulating etiological driver and its stereo-specific antibody is valuable for early PE diagnosis and treatment.

MIF Increases sFLT1 Expression in Early Uncomplicated Pregnancy and Preeclampsia

Insufficient immune tolerance during pregnancy is associated with pathological conditions such as preeclampsia (PE). Soluble fms-like tyrosine kinase-1 (sFLT1), which exerts a role in the late stage of PE, has shown its beneficial anti-inflammatory effects in inflammation-associated diseases. Macrophage migration inhibitory factor (MIF) was reported to upregulate sFLT1 production in experimental congenital diaphragmatic hernia. However, the placental sFLT1 expression in early uncomplicated pregnancy and whether MIF can regulate sFLT1 expression in uncomplicated and preeclamptic pregnancy are unclear. We collected first-trimester placentas and term placentas from uncomplicated and preeclamptic pregnancies to investigate sFLT1 and MIF expression in vivo. Primary cytotrophoblasts (CTBs) and a human trophoblast cell line (Bewo) were used to study the regulation of MIF on sFLT1 expression in vitro. In placentas from first-trimester pregnancy, we observed a high expression of sFLT1, specifically in extravillous trophoblasts (EVTs) and syncytiotrophoblast (STB) cells. MIF mRNA levels strongly correlated with sFLT1 expression in term placentas from preeclamptic pregnancies. In in vitro experiments, sFLT1 and MIF levels increased significantly in CTBs during their differentiation to EVTs and STBs, and MIF inhibitor (ISO-1) significantly reduced sFLT1 expression in a dose-dependent manner during this process. sFLT1 showed significant upregulation with increasing doses of MIF in Bewo cells. Our results show that sFLT1 is highly expressed at the maternal-fetal interface during early pregnancy and that MIF can increase sFLT1 expression in early uncomplicated pregnancy and PE, which suggests that sFLT1 plays an essential role in the modulation of inflammation in pregnancy.

First‐trimester plasma extracellular heat shock proteins levels and risk of preeclampsia

Preeclampsia (PE) occurs annually in 8% of pregnancies. Patients without risk factors represent 10% of these. There are currently no first-trimester biochemical markers that accurately predict PE. An increase in serum 60- and 70-KDa extracellular heat shock proteins (eHsp) has been shown in patients who developed PE at 34 weeks. We sought to determine whether there is a relationship between first-trimester eHsp and the development of PE. This was a prospective cohort study performed at a third level hospital in Mexico City from 2019 to 2020. eHsp levels were measured during the first-trimester ultrasound in singleton pregnancies with no comorbidities. First-trimester eHsp levels and biochemical parameters of organ dysfunction were compared between patients who developed preeclampsia and those who did not. All statistical analyses and model of correlation (r) between eHsp and clinical parameter were performed using bootstrapping R-software. p-values <0.05 were considered significant. The final analysis included 41 patients. PE occurred in 11 cases. eHsp-60 and eHsp-70 were significantly higher at 12 weeks in patients who developed PE (p = 0.001), while eHsp-27 was significantly lower (p = 0.004). Significant differences in first-trimester eHsp concentration suggest that these are possible early biomarkers useful for the prediction of PE.

Placental Cell Conditioned Media Modifies Hematopoietic Stem Cell Transcriptome In Vitro

Background

Hematopoietic stem cells are cells that differentiate into all blood cell types. Although the placenta secretes hormones, proteins and other factors important for maternal and fetal health, cross-talk between placental cells and hematopoietic stem cells is poorly understood. Moreover, toxicant impacts on placental-hematopoietic stem cell communication is understudied. The goals of this study were to determine if factors secreted from placental cells alter transcriptomic responses in hematopoietic stem cells and if monoethylhexyl phthalate (MEHP), the bioactive metabolite of the pollutant diethylhexyl phthalate, modifies these effects.

Methods

We used K-562 and BeWo cells as in vitro models of hematopoietic stem cells and placental syncytiotrophoblasts, respectively. We treated K-562 cells with medium conditioned by incubation with BeWo cells, medium conditioned with BeWo cells treated with 10 μM MEHP for 24 hours, or controls treated with unconditioned medium. We extracted K-562 cell RNA, performed RNA sequencing, then conducted differential gene expression and pathway analysis by treatment group.

Results

Relative to controls, K-562 cells treated with BeWo cell conditioned medium differentially expressed 173 genes (FDR<0.05 and fold-change>2.0), including 2.4 fold upregulatation of TPM4 and 3.3 fold upregulatation of S1PR3. Upregulated genes were enriched for pathways including stem cell maintenance, cell proliferation and immune processes. Downregulated genes were enriched for terms involved in protein translation and transcriptional regulation. MEHP treatment differentially expressed eight genes (FDR<0.05), including genes involved in lipid metabolism (PLIN2, fold-change: 1.4; CPT1A, fold-change: 1.4).

Conclusion

K-562 cells, a model of hematopoietic stem cells, are responsive to media conditioned by placental cells, potentially impacting pathways like stem cell maintenance and proliferation.

Ligustrazine promotes hypoxia/reoxygenation-treated trophoblast cell proliferation and migration by regulating the microRNA-27a-3p/ATF3 axis

OBJECTIVE

Preeclampsia (PE) is a pregnancy-specific syndrome. Ligustrazine (LSZ) is involved in hypoxia/reoxygenation (H/R)-treated trophoblast cell regulation, but its mechanism remains elusive. This study explored the mechanism of LSZ in H/R-treated trophoblast cells to provide a theoretical basis for the new treatment method development for PE.

METHODS

H/R HTR8/SVneo cell model was established for PE simulation to some extent. Trophoblast cell proliferation, apoptosis rate, migration, and invasion were detected by MTT assay, flow cytometry, scratch test, and Transwell assay. miR-27a-3p expression in trophoblast cells was detected by RT-qPCR. Binding sites between miR-27a-3p and ATF3 were predicted using Starbase and verified by dual-luciferase reporter assay. Activating transcription factor 3 (ATF3), β-catenin, Cyclin D1, and c-Myc protein levels were examined using Western blot. After LSZ treatment, H/R-induced HTR8/SVneo cells were delivered with miR-27a-3p mimic or ATF3 siRNA to verify their roles in HTR8/SVneo cells.

RESULTS

LSZ facilitated the proliferation, migration, and invasion of trophoblast cells and inhibited apoptosis. miR-27a-3p was elevated in H/R-induced HTR8/SVneo cells and miR-27a-3p overexpression annulled the effect of LSZ on trophoblast cells. miR-27a-3p targeted ATF3. ATF3 silencing averted the property of LSZ on trophoblast cells. Wnt/β-catenin pathway-related proteins were repressed in H/R-induced HTR8/SVneo cells, and LSZ activated the Wnt/β-catenin pathway by promoting ATF3 expression.

CONCLUSION

LSZ mediated the Wnt pathway by regulating the miR-27a-3p/ATF3 axis, thus promoting the proliferation and migration of trophoblast cells. The protective mechanism of LSZ showed the potential application value in the treatment of PE.

Roles of human trophoblasts' pattern recognition receptors in host defense and pregnancy complications

The immune system in pregnancy is able to protect pregnant mothers and fetuses from pathogenic microorganisms even while permitting the mother to tolerate the semi-allogenic fetus. Trophoblasts, which are fetal-derived placental cells, play a central role on both sides of this duality at the maternal-fetal interface. In brief, the trophoblasts express pattern recognition receptors (PRRs) and are involved in the local innate immune response in the placenta. That response eliminates pathogenic microbes but also causes tissue damage. In this review, we summarize the research findings to date regarding the roles of those human trophoblast PRRs. Multiple types of PRRs (Toll-like receptors, Nod-like receptors, and RIG-I-like receptors) are expressed in the placenta and on trophoblasts. Trophoblasts' PRRs participate in protecting the fetus against viruses, bacteria, and parasites by triggering production of proinflammatory cytokines and chemokines in the placenta. On the negative side, PRR signaling in trophoblasts can also initiate inflammation and trophoblast cell death, which can lead to placental inflammation-associated pregnancy complications such as preeclampsia, anti-phospholipid antibody syndrome, and miscarriage. Further elucidation of these dual roles of trophoblasts' PRRs may shed light on the mechanisms by which fetuses are protected against congenital infections and also give us a better understanding of the etiologies of pregnancy complications, which can help us prevent/reduce adverse prenatal/neonatal outcomes.

Mono(2-ethylhexyl) phthalate induces transcriptomic changes in placental cells based on concentration, fetal sex, and trophoblast cell type

Phthalates are ubiquitous plasticizer chemicals found in consumer products. Exposure to phthalates during pregnancy has been associated with adverse pregnancy and birth outcomes and differences in placental gene expression in human studies. The objective of this research was to evaluate global changes in placental gene expression via RNA sequencing in two placental cell models following exposure to the phthalate metabolite mono(2-ethylhexyl) phthalate (MEHP). HTR-8/SVneo and primary syncytiotrophoblast cells were exposed to three concentrations (1, 90, 180 µM) of MEHP for 24 h with DMSO (0.1%) as a vehicle control. mRNA and lncRNAs were quantified using paired-end RNA sequencing, followed by identification of differentially expressed genes (DEGs), significant KEGG pathways, and enriched transcription factors (TFs). MEHP caused gene expression changes across all concentrations for HTR-8/SVneo and primary syncytiotrophoblast cells. Sex-stratified analysis of primary cells identified different patterns of sensitivity in response to MEHP dose by sex, with male placentas being more responsive to MEHP exposure. Pathway analysis identified 11 KEGG pathways significantly associated with at least one concentration in both cell types. Four ligand-inducible nuclear hormone TFs (PPARG, PPARD, ESR1, AR) were enriched in at least three treatment groups. Overall, we demonstrated that MEHP differentially affects placental gene expression based on concentration, fetal sex, and trophoblast cell type. This study confirms prior studies, as enrichment of nuclear hormone receptor TFs were concordant with previously published mechanisms of phthalate disruption, and generates new hypotheses, as we identified many pathways and genes not previously linked to phthalate exposure.

N6-methyladenosine modification in trophoblasts promotes circSETD2 expression, inhibits miR-181a-5p, and elevates MCL1 transcription to reduce apoptosis of trophoblasts

Preeclampsia (PE) is an obstetric disorder. N6-methyladenosine (m6A) modification is related to PE trophoblast biological behaviors. This study explored the mechanism of m6A-modified circSETD2 in trophoblast biological behaviors. Chorionic trophoblast apoptosis and circSETD2 expression in PE rat models were detected. HTR8/SVneo cells were induced by CoCl2 to establish PE trophoblast models. circSETD2 was silenced or overexpressed to evaluate its effect on cell proliferation, invasion, and apoptosis. m6A level of circSETD2 in trophoblasts was changed by pcDNA3.1-METTL3 and pcDNA3.1-FTO. The targeting relations among miR-181a-5p, circSETD2, and MCL1 were verified by dual-luciferase assay. miR-181a-5p and MCL1 expressions were interfered with to confirm the effect of m6A-modified circSETD2. m6A methylation level was changed in PE rats for in vivo validation. PE rats showed diminished circSETD2 expression and increased apoptosis index. circSETD2 overexpression promoted trophoblast proliferation and invasion, and reduced apoptosis. METTL3 overexpression increased total m6A, circSETD2 m6A, and circSETD2 levels. m6A modification mediated circSETD2 upregulation. circSETD2 was a sponge of miR-181a-5p to elevate MCL1 transcription. miR-181a-5p overexpression or MCL1 silencing annulled the role of m6A-modified circSETD2. circSETD2 inhibition negated suppression of METTL3 overexpression on chorionic trophoblast apoptosis in vivo. Collectively, m6A modification of circSETD2 suppressed miR-181a-5p and increased MCL1 transcription, thus regulating trophoblasts.

Matrix metalloproteinase -12: A marker of preeclampsia?

INTRODUCTION

Enzymes, including matrix metalloproteinases (MMPs), play a significant role in trophoblast invasion - the cornerstone of preeclampsia pathogenesis.

METHODS

This study aimed to explore the dynamics of the MMP-12 concentration in blood serum during the gestational period at determined weeks in preeclampsia and physiological pregnancy to compare the results with the expression of MMP-12 in placental tissue and reveal the MMP-12 predicting role in preeclampsia.

RESULTS

Circulating serum MMP-12 was significantly decreased. The level of 0.5 ng/ml had high sensitivity and low false positivity at 11-13 weeks of pregnancy in women destined to develop pre-eclampsia in the case-control study. The dynamics curve of serum MMP-12 varied between study groups: a sharp decrease in MMP-12 concentration was found from the first trimester to the second trimester, followed by a slight increase in the third trimester of pregnancy in controls compared to the increase in concentration from the first trimester to the second trimester in pre-eclampsia. The absence of a significant difference in the concentration of MMP-12 in the II and III trimesters as well as no difference in the expression of MMP-12 protein in placental tissue in the third trimester indicates a decrease in its role after the end of placentation.

DISCUSSION

To our knowledge, this is the first study to show the dynamics of serum MMP-12 concentration during the gestational period and indicates a significant role for MMP-12 in the initial stages of placentation. The data obtained may pave the way to new early prediction strategies for preeclampsia.

Effects of KCa channels on biological behavior of trophoblasts

The Ca²⁺-activated potassium (KCa) channels are involved in many cellular functions, but their roles in trophoblasts are unclear. This study aimed to clarify the effects of KCa channels on the biological behavior of trophoblasts. The localization and expression of the three types of KCa channels, including large-conductance KCa channels (BKCa), intermediate-conductance KCa channels (IKCa), and small-conductance KCa channels (SKCa), were detected in human chorionic villi taken from pregnant women between 5 and 8 weeks of gestation (n = 15) and HTR-8/SVneo cells. The effects of KCa channels on proliferation, apoptosis, and migration of HTR-8/SVneo cells were examined by using the activators or inhibitors of KCa channels. Results showed that KCa channels were mainly localized on the membrane and in the cytoplasm of trophoblasts in human chorionic villi and HTR-8/SVneo cells. The proliferation and migration of HTR-8/SVneo cells were inhibited by activating KCa channels. Apoptosis of trophoblasts was promoted through activating BKCa channels but was not affected by neither activating nor inhibiting IKCa and SKCa channels. This study substantiated the abovementioned biological roles of KCa channels in trophoblast cells, which is fundamental to further research on whether dysfunction of KCa channels is involved in the pathogenesis of pregnancy-related complications.

Fetoplacental transmission and placental response to SARS-CoV-2: Evidence from the literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a dreadful novel coronavirus with global health concerns among pregnant women. To date, the vertical transmission of SARS-CoV-2 during pregnancy remains controversial. We briefly report recent findings of placental response to SARS-CoV-2 infection and updates on vertical transmission. We systematically searched PubMed and Google Scholar databases according to PRISMA guidelines for studies reporting the effects of SARS-CoV-2 infection on the placenta and possibility of vertical transmission. We identified 45 studies reporting 1,280 human placentas that were analyzed by molecular pathology methods and 11,112 placenta-derived cells from a publicly available database that was analyzed using bioinformatics tools. The main finding of this study is that the SARS-CoV-2 canonical entry receptors (ACE2 and TMPRSS2) are abundantly expressed on the placenta during the first trimester, and this expression diminishes across gestational age. Out of 45 eligible studies identified, 24 (53.34%) showed no evidence of vertical transmission, 15 (33.33%) supported the hypothesis of very rare, low possibility of vertical transmission and 6 (13.33%) were indecisive and had no comment on vertical transmission. Furthermore, 433 placentas from 12 studies were also identified for placental pathology investigation. There was evidence of at least one form of maternal vascular malperfusion (MVM), 57/433 (13.1%), fetal vascular malperfusion (FVM), 81/433 (18.7%) and placental inflammation with excessive infiltration of CD3+ CD8+ lymphocytes, CD68+ macrophages and CD20+ lymphocytes in most of the eligible studies. Decidual vasculopathy (3.2%), infarction (3.2%), chronic histiocytic intervillositis (6.0%), thrombi vasculopathy (5.1%) were also observed in most of the MVM and FVM reported cases. The results indicated that SARS-CoV-2 induces placenta inflammation, and placenta susceptibility to SARS-CoV-2 decreases across the pregnancy window. Thus, SARS-CoV-2 infection in early pregnancy may adversely affect the developing fetus.

Transforming growth factor-β signaling governs the differentiation program of extravillous trophoblasts in the developing human placenta

Abnormal placentation has been noticed in a variety of pregnancy complications such as miscarriage, early-onset preeclampsia, and fetal growth restriction. Defects in the developmental program of extravillous trophoblasts (EVTs), migrating from placental anchoring villi into the maternal decidua and its vessels, is thought to be an underlying cause. Yet, key regulatory mechanisms controlling commitment and differentiation of the invasive trophoblast lineage remain largely elusive. Herein, comparative gene expression analyses of HLA-G-purified EVTs, isolated from donor-matched placenta, decidua, and trophoblast organoids (TB-ORGs), revealed biological processes and signaling pathways governing EVT development. In particular, bioinformatics analyses and manipulations in different versatile trophoblast cell models unraveled transforming growth factor-β (TGF-β) signaling as a crucial pathway driving differentiation of placental EVTs into decidual EVTs, the latter showing enrichment of a secretory gene signature. Removal of Wingless signaling and subsequent activation of the TGF-β pathway were required for the formation of human leukocyte antigen-G⁺ (HLA-G⁺) EVTs in TB-ORGs that resemble in situ EVTs at the level of global gene expression. Accordingly, TGF-β-treated EVTs secreted enzymes, such as DAO and PAPPA2, which were predominantly expressed by decidual EVTs. Their genes were controlled by EVT-specific induction and genomic binding of the TGF-β downstream effector SMAD3. In summary, TGF-β signaling plays a key role in human placental development governing the differentiation program of EVTs.

Single-cell transcriptional profiling reveals cellular and molecular divergence in human maternal-fetal interface

Placenta plays essential role in successful pregnancy, as the most important organ connecting and interplaying between mother and fetus. However, the cellular characteristics and molecular interaction of cell populations within the fetomaternal interface is still poorly understood. Here, we surveyed the single-cell transcriptomic landscape of human full-term placenta and revealed the heterogeneity of cytotrophoblast cell (CTB) and stromal cell (STR) with the fetal/maternal origin consecutively localized from fetal section (FS), middle section (Mid_S) to maternal section (Mat_S) of maternal–fetal interface. Then, we highlighted a subpopulation of CTB, named trophoblast progenitor-like cells (TPLCs) existed in the full-term placenta and mainly distributed in Mid_S, with high expression of a pool of putative cell surface markers. Further, we revealed the putative key transcription factor PRDM6 that might promote the differentiation of endovascular extravillous trophoblast cells (enEVT) by inhibiting cell proliferation, and down-regulation of PRDM6 might lead to an abnormal enEVT differentiation process in PE. Together, our study offers important resources for better understanding of human placenta and stem cell-based therapy, and provides new insights on the study of tissue heterogeneity, the clinical prevention and control of PE as well as the maternal–fetal interface.

Antinuclear antibodies in follicular fluid may be a risk factor in vitro fertilization and embryo transfer

OBJECTIVE

To explore the effect of anti-nuclear antibodies (ANAs) on the outcome of in vitro fertilization-embryo transplantation (IVF-ET) and to study the effect of ANAs in follicular fluid (FF) on embryonic development.

METHODS

The expression of ANAs in FF of patients treated with IVF-ET and healthy group. The patients were divided into ANAs-positive group and ANA-negative group. The age, duration of infertility, body mass index (BMI), basic follicle stimulating hormone (bFSH), anti-Mullerian hormone (AMH), number of retrieved oocytes, portion of metaphase II oocytes (MII), number of embryos in the cleavage stage, bipronuclear (2PN), number of embryos, number of high-quality embryos and the outcome of IVF-ET were compared between the two groups. In vitro, HTR8/SVneo trophoblast cells were cultivated and divided into ANAs-negative group (control group) and ANAs-positive group (ANAs-positive FF was added to cytotrophoblasts). The ANAs titer in the serum and FF of patients who treated with IVF-ET was detected using ELSIA method. CCK-8 assay and flow cytometry (at 24 h and at 48 h) were used to detect the cell proliferation and apoptosis frequency of the two groups, respectively.

RESULTS

Among those who underwent IVF-ET treatment, the number of retrieved oocytes, the number of fertilization and the portion of MII oocytes in the FF-positive group were significantly lower than those in the FF-negative group. Furthermore, the implantation rate and the clinical pregnancy rate were decreased, and early miscarriage rate was increased in the FF-positive patients than those in the FF-negative patients. In vitro, the cytotrophoblasts proliferation activity in the ANAs group was significantly lower than that in the control group. Moreover, the cytotrophoblasts apoptosis rate in the ANAs group was significantly higher than that in the control group.

CONCLUSIONS

Our data suggested that ANAs in FF might become an obstacle to embryonic development through promoting trophoblast apoptosis and inhibiting trophoblast proliferation. ANAs in FF might be an unfavorable factor for the outcome of those who undergo IVF-ET treatment.

Current Studies of Mitochondrial Quality Control in the Preeclampsia

Mitochondria are cellular energy powerhouses that play important roles in regulating cellular processes. Mitochondrial quality control (mQC), including mitochondrial biogenesis, mitophagy, mitochondrial fusion and fission, maintains physiological demand and adapts to changed conditions. mQC has been widely investigated in neurodegeneration, cardiovascular disease and cancer because of the high demand for ATP in these diseases. Although placental implantation and fetal growth similarly require a large amount of energy, the investigation of mQC in placental-originated preeclampsia (PE) is limited. We elucidate mitochondrial morphology and function in different pregnancy stages, outline the role of mQC in cellular homeostasis and PE and summarize the current findings of mQC-related PE studies. This review also provides suggestions on the future investigation of mQC in PE, which will lead to the development of new prevention and therapy strategies for PE.

WNT and NOTCH signaling in human trophoblast development and differentiation

Correct development of the human placenta and its differentiated epithelial cells, syncytial trophoblasts (STBs) and extravillous trophoblasts (EVTs), is crucial for a successful pregnancy outcome. STBs develop by cell fusion of mononuclear cytotrophoblasts (CTBs) in placental floating villi, whereas migratory EVTs originate from specialized villi anchoring to the maternal decidua. Defects in trophoblast differentiation have been associated with severe pregnancy disorders such as early-onset preeclampsia and fetal growth restriction. However, the evolutionary pathways underlying normal and adverse placentation are poorly understood. Herein, we discuss Wingless (WNT) and NOTCH signaling, two pathways that play pivotal roles in human placenta and trophoblast development. Whereas WNT is necessary for expansion of trophoblast progenitors and stem cells, NOTCH1 is required for proliferation and survival of EVT precursors. Differentiation of the latter is orchestrated by a switch in NOTCH receptor expression as well as by changes in WNT ligands and their downstream effectors.

Role of autocrine bone morphogenetic protein Signaling in trophoblast stem cells

The Bone Morphogenetic Protein (BMP) pathway is involved in numerous developmental processes, including cell growth, apoptosis, and differentiation. In mouse embryogenesis, BMP signaling is a well-known morphogen for both mesoderm induction and germ cell development. Recent evidence points to a potential role in development of the extra-embryonic compartment, including trophectoderm-derived tissues. In this study, we investigated the effect of BMP signaling in both mouse and human trophoblast stem cells (TSC) in vitro, evaluating the expression and activation of the BMP signaling response machinery, and the effect of BMP signaling manipulation during TSC maintenance and differentiation. Both mTSC and hTSC expressed various BMP ligands and the receptors BMPR1A and BMPR2, necessary for BMP response, and displayed maximal active BMP signaling when undifferentiated. We also observed a conserved modulatory role of BMP signaling during trophoblast differentiation, whereby maintenance of active BMP signaling blunted differentiation of TSC in both species. Conversely, the effect of BMP signaling on the undifferentiated state of TSC appeared to be species-specific, with SMAD-independent signaling important in maintenance of mTSC, and a more subtle role for both SMAD-dependent and -independent BMP signaling in hTSC. Altogether, these data establish an autocrine role for the BMP pathway in the trophoblast compartment. As specification and correct differentiation of the extra-embryonic compartment are fundamental for implantation and early placental development, insights on the role of the BMP signaling in early development might prove useful in the setting of in vitro fertilization as well as targeting trophoblast-associated placental dysfunction.

Whole transcriptome analysis of trophoblasts under hypoxia

INTRODUCTION

A physiological hypoxia environment exists at maternal-fetal interface during early pregnancy. In addition, there is a pathological hypoxic microenvironment in patients with preeclampsia. Therefore, investigating the hypoxic adaptation and the effects of hypoxia on trophoblasts transcriptome is helpful to better understand the function and regulatory mechanism of trophoblasts at the maternal-fetal interface.

METHODS

Trophoblast cell line HTR-8/SVneo was cultured under normoxia and hypoxia for 24 h, the full transcriptome was analyzed via RNA-Seq. GO and KEGG enrichment were performed on differentially expressed mRNA, adjacent genes of differentially expressed lncRNA, host genes of differentially expressed circRNA and target genes of differential expressed miRNA.

RESULTS

The results showed that hypoxia differentially regulated 373 mRNAs, 334 lncRNAs, 71 circRNAs and 33 miRNAs. GO and KEGG enrichment showed that hypoxia negatively regulated TLR3 and PI3K-Akt signaling pathways. Consistently, we found hypoxia significantly inhibited TLR3 agonist-induced cytokines expression and the phosphorylation of Akt and mTOR.

DISCUSSION

Our study obtained the full transcriptome data and potential regulatory network of trophoblasts under hypoxia, providing supportive data for revealing the function of trophoblasts.

Decreased Expression of Cytotoxic Proteins in Decidual CD8+ T Cells in Preeclampsia

Simple Summary

CD8⁺ T cells are prominent decidual cells in the third trimester of healthy human pregnancy. They have a cytotoxic capacity which may control invasion of extravillous trophoblast and therefore affect placentation and play the role in development of preeclampsia. In this study, we examined the expression of CD8⁺ T cells in decidual tissue and peripheral blood of women with severe and mild preeclampsia in comparison to gestational age-matched healthy pregnancies. Additionally, the expression of cytotoxic proteins in CD8⁺ T cells was examined in order to specify their subpopulations.

Abstract

In our study, we aimed to establish expression of cytotoxic CD8⁺ T cells in the decidua basalis and the maternal peripheral blood (mPBL) of severe and mild preeclampsia (PE) and compare to healthy pregnancies. Decidual tissue and mPBL of 10 women with mild PE, 10 women with severe PE, and 20 age-matched healthy pregnancy controls were analyzed by double immunofluorescence and qPCR, respectively. By double immunofluorescence staining, we found a decreased total number of cells/mm² in decidua basalis of granulysin (GNLY)⁺ (p ˂ 0.0001), granzyme B (GzB)⁺(p ˂ 0.0001), GzB⁺CD8⁺(p ˂ 0.0001), perforin (PRF1)⁺ (p ˂ 0.0001), and PRF1⁺CD8⁺ (p ˂ 0.01) in the severe PE compared to control group. Additionally, we noticed the trend of lower mRNA expression for GNLY, granzyme A (GZMA), GzB, and PRF1 in CD8⁺ T cells of mPBL in mild and severe PE, with the latter marker statistically decreased in severe PE (p ˂ 0.001). Forkhead box P3 (FOXP3) mRNA in CD8⁺ T cells mPBL was increased in mild PE (p ˂ 0.001) compared to controls. In conclusion, severe PE is characterized by altered expression of cytotoxic CD8⁺ T cells in decidua and mPBL, suggesting their role in pathophysiology of PE and fetal-maternal immune tolerance.

Maternal exposure to tributyltin during early gestation increases adverse pregnancy outcomes by impairing placental development

Tributyltin (TBT) is a persistent organotin pollutant widely used as agricultural and wood biocides, exhibiting well-documented toxicity to reproductive functions in aquatic organisms. However, the effect of TBT on early pregnancy and placental development has been rarely studied in mice. Pregnant mice were fed with 0, 0.2, and 2 mg/kg/day TBT from gravid day 1 to day 8 or 13. TBT exposure led to an increase in the number of resorbed embryo and a reduction in the weight of fetus at gestational days 13. Further study showed that TBT significantly decreased placental weight and area, lowered laminin immunoreactivity and the expressions of placental development-related molecules including Fra1, Eomes, Hand1, and Ascl2. Moreover, TBT treatment markedly inhibited the placental proliferation and induced up-regulation of p53 and cleaved caspase-3 proteins, and down-regulation of Bcl-2 protein. In addition, TBT administration increased levels of malondialdehyde and H₂ O₂ and decreased activities of catalase and superoxide dismutase. Collectively, these results suggested TBT-induced adverse pregnancy outcomes during early pregnancy might be involved in developmental disorders of the placenta via dysregulation of key molecules, proliferation, apoptosis, and oxidative stress.

Modeling preeclampsia using human induced pluripotent stem cells

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder, affecting up to 10% of pregnancies worldwide. The primary etiology is considered to be abnormal development and function of placental cells called trophoblasts. We previously developed a two-step protocol for differentiation of human pluripotent stem cells, first into cytotrophoblast (CTB) progenitor-like cells, and then into both syncytiotrophoblast (STB)- and extravillous trophoblast (EVT)-like cells, and showed that it can model both normal and abnormal trophoblast differentiation. We have now applied this protocol to induced pluripotent stem cells (iPSC) derived from placentas of pregnancies with or without PE. While there were no differences in CTB induction or EVT formation, PE-iPSC-derived trophoblast showed a defect in syncytialization, as well as a blunted response to hypoxia. RNAseq analysis showed defects in STB formation and response to hypoxia; however, DNA methylation changes were minimal, corresponding only to changes in response to hypoxia. Overall, PE-iPSC recapitulated multiple defects associated with placental dysfunction, including a lack of response to decreased oxygen tension. This emphasizes the importance of the maternal microenvironment in normal placentation, and highlights potential pathways that can be targeted for diagnosis or therapy, while absence of marked DNA methylation changes suggests that other regulatory mechanisms mediate these alterations.

Decreased circUBAP2 Expression Is Associated with Preeclampsia by Limiting Trophoblast Cell Proliferation and Migration

Preeclampsia (PE) is a common obstetric disease and a major cause of maternal, newborn, and fetal death. This condition is a multisystem disorder characterized by hypertension, proteinuria, and involvement of the kidney, liver, and nervous system. It is generally believed that the placenta is the main cause of PE. circRNAs are a special class of noncoding RNAs that can form covalently closed continuous ring structures with tissue-specific conservation, and they have been reported to play a wide range of regulatory functions in various diseases, including PE. In this study, we reported a novel circUBAP2 (hsa_circ_0003496) and found that it was downregulated in placental tissues from patients with PE compared to healthy controls. After knocking down circUBAP2 in trophoblast cells, we found that cell proliferation and migration were significantly suppressed. In addition, preliminary mechanistic studies showed that circUBAP2 can sponge miR-1244, and FOXM1 was identified as a target gene for miR-1244. Cotransfection of si-circUBAP2 and a miR-1244 inhibitor partially reversed the suppressive effect induced by circUBAP2 depletion on proliferation and migration. In conclusion, the circUBAP2/miR-1244/FOXM1 axis might be a promising molecular marker for the diagnosis and treatment of PE.