Trophoblast Research Articles

Transcription factor-based transdifferentiation of human embryonic to trophoblast stem cells

ABSTRACT During the first week of development, human embryos form a blastocyst composed of an inner cell mass and trophectoderm (TE) cells, the latter of which are progenitors of placental trophoblast. Here, we investigated the expression of transcripts in the human TE from early to late blastocyst stages. We identified enrichment of the transcription factors GATA2, GATA3, TFAP2C and KLF5 and characterised their protein expression dynamics across TE development. By inducible overexpression and mRNA transfection, we determined that these factors, together with MYC, are sufficient to establish induced trophoblast stem cells (iTSCs) from primed human embryonic stem cells. These iTSCs self-renew and recapitulate morphological characteristics, gene expression profiles, and directed differentiation potential, similar to existing human TSCs. Systematic omission of each, or combinations of factors, revealed the crucial importance of GATA2 and GATA3 for iTSC transdifferentiation. Altogether, these findings provide insights into the transcription factor network that may be operational in the human TE and broaden the methods for establishing cellular models of early human placental progenitor cells, which may be useful in the future to model placental-associated diseases.

Reduced bioenergetics and mitochondrial fragmentation in human primary cytotrophoblasts induced by an EGFR-targeting chemical mixture

Exposures to complex environmental chemical mixtures during pregnancy reach and target the feto-placental unit. This study investigates the influence of environmental chemical mixtures on placental bioenergetics. Recognizing the essential role of the epidermal growth factor receptor (EGFR) in placental development and its role in stimulating glycolysis and mitochondrial respiration in trophoblast cells, we explored the effects of chemicals known to disrupt EGFR signaling on cellular energy production. Human primary cytotrophoblasts (hCTBs) and a first-trimester extravillous trophoblast cell line (HTR-8/SVneo) were exposed to a mixture of EGFR-interfering chemicals, including atrazine, bisphenol S, niclosamide, PCB-126, PCB-153, and trans-nonachlor. An RNA sequencing approach revealed that the mixture altered the transcriptional signature of genes involved in cellular energetics. Next, the impact of the mixture on cellular bioenergetics was evaluated using a combination of mitochondrial and glycolytic stress tests, ATP production, glucose consumption, lactate synthesis, and super-resolution imaging. The chemical mixture did not alter basal oxygen consumption but diminished the maximum respiratory capacity in a dose-dependent manner, indicating a disruption of mitochondrial function. The respiratory capacity and ATP production were increased by EGF, while the Chem-Mix reduced both EGF- and non-EGF-mediated oxygen consumption rate in hCTBs. A similar pattern was observed in the glycolytic medium acidification, with EGF increasing the acidification, and the Chem-Mix blocking EGF-induced glycolytic acidification. Furthermore, direct stochastic optical reconstruction microscopy (dSTORM) imaging demonstrated that the Chem-Mix led to a reduction of the mitochondrial network architecture, with findings supported by a decrease in the abundance of OPA1, a mitochondrial membrane GTPase involved in mitochondrial fusion. In conclusion, we demonstrated that a mixture of EGFR-disrupting chemicals alters mitochondrial remodeling, resulting in disturbed cellular bioenergetics, reducing the capacity of human cytotrophoblast cells to generate energy. Future studies should investigate the mechanism by which mitochondrial dynamics are disrupted and the pathological significance of these findings.

Alterations of Placental Sodium in Preeclampsia: Trophoblast Responses.

Evidence suggests that increasing salt intake in pregnancy lowers blood pressure, protecting against preeclampsia. We hypothesized that sodium (Na+) evokes beneficial placental signals that are disrupted in preeclampsia. Blood and urine were collected from nonpregnant women of reproductive age (n=26) and pregnant women with (n=50) and without (n=55) preeclampsia, along with placental biopsies. Human trophoblast cell lines and primary human trophoblasts were cultured with varying Na+ concentrations. Women with preeclampsia had reduced placental and urinary Na+ concentrations, yet increased urinary angiotensinogen and reduced active renin, aldosterone concentrations, and osmotic response signal TonEBP (tonicity-responsive enhancer binding protein) expression. In trophoblast cell cultures, TonEBP was consistently increased upon augmented Na+ exposure. Mechanistically, inhibiting Na+/K+-ATPase or adding mannitol evoked the TonEBP response, whereas inhibition of cytoskeletal signaling abolished it. Enhanced Na+ availability induced osmotic gradient-dependent cytoskeletal signals in trophoblasts, resulting in proangiogenic responses. As placental salt availability is compromised in preeclampsia, adverse systemic responses are thus conceivable.

The short-chain fatty acid butyrate promotes trophoblast differentiation and cell fusion

The short-chain fatty acid butyrate promotes trophoblast differentiation and cell fusion

Nanoparticle-mediated delivery of placental gene therapy via uterine artery catheterization in a pregnant rhesus macaque

Nanoparticles offer promise as a mechanism to non-invasively deliver targeted placental therapeutics. Our previous studies utilizing intraplacental administration demonstrate efficient nanoparticle uptake into placental trophoblast cells and overexpression of human IGF1 (hIGF1). Nanoparticle-mediated placental overexpression of hIGF1 in small animal models of placental insufficiency and fetal growth restriction improved nutrient transport and restored fetal growth. The objective of this pilot study was to extend these studies to the pregnant nonhuman primate and develop a method for local delivery of nanoparticles to the placenta via maternal blood flow from the uterine artery. Nanoparticles containing hIGF1 plasmid driven by the placenta-specific PLAC1 promoter were delivered to a mid-gestation pregnant rhesus macaque via a catheterization approach that is clinically used for uterine artery embolization. Maternal-fetal interface, fetal and maternal tissues were collected four days post-treatment to evaluate the efficacy of hIGF1 treatment in the placenta. The uterine artery catheterization procedure and nanoparticle treatment was well tolerated by the dam and fetus through the four-day study period following catheterization. Nanoparticles were taken up by the placenta from maternal blood as plasmid-specific hIGF1 expression was detected in multiple regions of the placenta via in situ hybridization and qPCR. The uterine artery catheterization approach enabled successful delivery of nanoparticles to maternal circulation in close proximity to the placenta with no concerns to maternal or fetal health in this short-term feasibility study. In the future, this delivery approach can be used for preclinical evaluation of the long-term safety and efficacy of nanoparticle-mediated placental therapies in a rhesus macaque model.

Abstract P194: Metabolic effects of GDF15 and Activin A on trophoblasts

Preeclampsia (PE), a pregnancy-related complication, is a major cause of maternal and fetal morbidity and mortality. The pathophysiology is not fully elucidated. Activin A and GDF15 are part of the TGFβ superfamily and markers for trophoblast differentiation. Both are senescence associated secretory phenotype (SASP) factors that have been associated with cardiovascular disease. Mitochondrial dysfunction is associated with SASP and both have been described in PE. Serum levels of GDF15 and Activin A, were elevated in the maternal blood prior to the onset of PE and found to be elevated in placental tissue of women with PE. BeWo cells were metabolically reprogrammed to a physiological glucose-environment by cultivating them for 10-15 passages in a cell culture medium with 5.5 mM glucose as opposed to the standard high-glucose environment at 17.1mM. Next, BeWo cells were differentiated into multinucleated syncytiotrophoblasts with Forskolin, and with DMSO as solvent control to model cytotrophoblasts. Subsequently, these two trophoblast differentiation states were treated with GDF15 (20 ng/ml) and Activin A (20ng/ml) and the cell metabolic profile was analyzed. Additionally, a single cell human trophoblast organoid transcriptomics dataset from Shannon et al. was investigated for expression patterns of GDF15 and INHBA (Activin A) together with the overall metabolic profile of trophoblast cells. Treating BeWo cells with Activin A and GDF15 leads to an increase in mitochondrial activity, shown by elevated ATP levels in syncytiotrophoblast and an increase in mitochondrial membrane potential in cytotrophoblasts. Additionally, the oxygen consumption rate is significantly higher in syncytiotrophoblasts after Activin A and GDF15 treatment. In human trophoblast organoids, syncytiotrophoblasts showed the lowest metabolic activity measured by the expression of genes related to glycolysis and mitochondrial respiratory chain. Furthermore, GDF15 and INHBA (Activin A) were strongly expressed in syncytiotrophoblasts. Together, Activin A and GDF15 stimulation increases the metabolic activity in BeWo cells. As preeclampsia is associated with mitochondrial dysfunction as well as with senescence, our data indicate a potential role of Activin A and GDF15 in preeclampsia development.

P10-19 A comparative study of the cytotoxic effects of cannabidiol and minor cannabinoids on placental trophoblast cells

P10-19 A comparative study of the cytotoxic effects of cannabidiol and minor cannabinoids on placental trophoblast cells

TROP2 in colorectal carcinoma: associations with histopathology, molecular phenotype, and patient prognosis.

Antibody-drug conjugates (ADCs) directed to trophoblast cell surface antigen 2 (TROP2) have gained approval as a therapeutic option for advanced triple-negative breast cancer, and TROP2 expression has been linked to unfavourable outcomes in various malignancies. In colorectal carcinoma (CRC), there is still a lack of comprehensive studies on its expression frequency and its prognostic implications in relation to the main clinicopathological parameters. We examined the expression of TROP2 in a large cohort of 1,052 CRC cases and correlated our findings with histopathological and molecular parameters, tumour stage, and patient outcomes. TROP2 was heterogeneously expressed in 214/1,052 CRCs (20.3%), with only a fraction of strongly positive tumours. TROP2 expression significantly correlated with an invasive histological phenotype (e.g. increased tumour budding/aggressive histopathological subtypes), advanced tumour stage, microsatellite stable tumours, and p53 alterations. While TROP2 expression was prognostic in univariable analyses of the overall cohort (e.g. for disease-free survival, p < 0.001), it exhibited distinct variations among important clinicopathological subgroups (e.g. right- versus left-sided CRC, microsatellite stable versus unstable CRC, Union for International Cancer Control [UICC] stages) and lost its significance in multivariable analyses that included stage and CRC histopathology. In summary, TROP2 is quite frequently expressed in CRC and associated with an aggressive histopathological phenotype and microsatellite stable tumours. Future clinical trials investigating anti-TROP2 ADCs should acknowledge the observed intratumoural heterogeneity, given that only a subset of TROP2-expressing CRC show strong positivity. The prognostic implications of TROP2 are complex and show substantial variations across crucial clinicopathological subgroups, thus indicating that TROP2 is a suboptimal parameter to predict patient prognosis.

Deciphering the role of rapamycin in modulating decidual senescence: implications for decidual remodeling and implantation failure.

Physiological decidual senescence promotes embryo implantation, whereas pathological decidual senescence causes many pregnancy pathologies. The aim of this study was to evaluate the effect of rapamycin on decidual cell subpopulations and endometrial function in physiological and induced senescence and to investigate the decidual cell subpopulations present in physiological conditions during early pregnancy and implantation in mice. Control, physiological decidualization (0.5mM cAMP and 1μM MPA added), and induced senescence (0.1mM HU added) models with and without 200nM rapamycin treatment were established using a human endometrial stromal cell line, and decidual cell subpopulations were analyzed by immunofluorescence and flow cytometry. The human extravillous trophoblast cell line AC-1M88 was also cultured in decidualization models, and spheroid expansion analysis was performed. In in vivo studies, decidual cell subpopulations were analyzed by immunofluorescence during early mouse pregnancy. The results revealed that rapamycin decreased DIO2 and β-GAL expressions in physiological and induced senescence without FOXO1. Notably, in induced senescence, increased fragmentation was observed in AC-1M88 cells, and rapamycin treatment successfully attenuated the fragmentation of spheroids. We showed that the FOXO1-DIO2 signaling axis can trigger decidual senescence during early gestation and days of implantation in mice. Our study underlines the importance of rapamycin in modulating decidual cell subpopulations and endometrial tissue function during decidual senescence. The information obtained may provide insight into the pathologies of pregnancy seen due to decidual senescence and guide better treatment strategies for reproductive problems.

Follistatin like 3 modulation of trophoblast cell development and hemochorial placentation

Follistatin like 3 modulation of trophoblast cell development and hemochorial placentation

Cellular fate during extravillous trophoblast cell differentiation

Cellular fate during extravillous trophoblast cell differentiation

Abstract P197: Identification and Characterization of Rho-related BTB Domain Containing 1 (RhoBTB1)-Cullin 3 (CUL3) Proteins in Placenta

Preeclampsia is life threatening condition affecting about 10% of all pregnancies. A potential mechanism is via malfunctioning syncytiotrophoblasts in the placenta. RhoBTB1 is an adapter protein for the CUL3 E3 ubiquitin ligase which delivers protein substrates for proteasomal degradation. An analysis of gene expression databases revealed that the highest level of RhoBTB1 expression is in the placenta. RNAscope in situ hybridization data reveals that RhoBTB1 expression is specifically localized to syncytiotrophoblasts. In blood vessels, RhoBTB1 controls the state of nitric oxide mediated vasodilation because it acts as a substrate adaptor for Phosphodiesterase 5. Thus, we wanted to identify potential protein targets of RhoBTB1 in the placenta to assess if RhoBTB1 plays a role in placental function. To simplify the first identification of RhoBTB1 binding proteins, we employed HTR-8 /SVneo (HTR-8) cells as a model of placental trophoblast cells. We biotinylated the HTR-8 proteome utilizing ascorbate peroxidase (APEX2) proximity labelling system followed by mass spectrometry to identify RhoBTB1 targets. We employed a fusion protein consisting of the C-terminal half of RhoBTB1 (B1B2C), the region required for the binding of other protein substrates, and a control lacking the most C-terminal region (B1B2). We next chose proteins with binding to B1B2C &gt; B1B2 of 2-fold or greater that were expressed in the placenta based on the Human Protein Atlas. Rho GTPase Activating Protein 29 (ARHGAP29), which controls the regulation of small GTP binding proteins, and S-phase Kinase associated Protein 2 (SKP2), a regulator of cell cycle progression was studied further. SKP2 is interesting because it exhibits a tissue specific tropism for placental expression with its highest expression in extravillous trophoblasts, cytotrophoblasts, and syncytiotrophoblasts. Expression of ARHGAP29 and SKP2 in HTR-8 cells were markedly upregulated by MLN4924 suggesting they are regulated by the CUL pathway. They were also modestly upregulated after partial inhibition of RhoBTB1 by siRNA suggesting they may be RhoBTB1-CUL3 targets. Studies are ongoing to validate the physical interaction of ARHGAP29 and SKP2 with RhoBTB1 by co-immunoprecipitation. We are also using RNAscope to assess the co-expression of RhoBTB1, ARHGAP29 and SKP2 in the human placenta from normal and preeclamptic pregnancies.

Papillomavirus infection and male infertility: A systematic review and meta-analysis.

Increasing attention is being paid to the role of human papillomavirus (HPV) in men and specifically reproduction. Growing evidence suggests an association between HPV infection with many adverse effects including the impairment of semen parameters, the increase of blastocyst apoptosis, the reduction of endometrial implantation of trophoblastic cells, as well as the increase rate of miscarriages and spontaneous preterm birth. We systematically searched PubMed/MEDLINE, Scopus, Embase, Web of Science, CINHAL, PsycINFO, and ERIC from inception to 2nd of July 2024, for studies that investigated the association between HPV infection with sperm parameters and fertility outcomes. The meta-analysis was conducted on mean data and standard deviations. We included 25 studies with a total of 6942 patients. Sperm morphology was lower in HPV positive groups versus HPV negative control groups (SMD = -0.52 95% CI -0.84; -0.21; p = 0.001). Sperm motility was also significantly lower in HPV positive groups when compared to HPV negative controls (SMD = -0.82 95% CI -1.07; -0.57; p = <0.001). Sperm volume, concentration, and pH were not significantly different between the two groups. The other 15 studies included in the systematic review for which it was not possible to conduct a meta-analysis showed strong associations between HPV infection and impairment of sperm parameters, reduced couple fertility and increased risk of pregnancy loss. The current evidence highlights the link between HPV infection and sperm parameters, male fertility and reproductive outcomes, which has the potential to lead to a decreased couple fertility, increased risk of pregnancy loss, re-infection and increased treatment costs.

Comprehensive Proteomic Analysis Reveals Distinct Features and a Diagnostic Biomarker Panel for Early Pregnancy Loss in Histological Subtypes

Early pregnancy loss (EPL) is a common event in human reproduction and is classified into histological subtypes such as hydropic abortion (HA) and hydatidiform moles (HMs), including complete hydatidiform moles (CHMs) and partial hydatidiform moles (PHMs). However, accurate diagnosis and improved patient management remain challenging due to high rates of misdiagnosis and diverse prognostic risks. Therefore, diagnostic biomarkers for EPL are urgently needed. Our study aimed to identify biomarkers for EPL through comprehensive proteomic analysis. Ten CHMs, six PHMs, ten HAs and ten normal control (NC) products of conception (POC) were used to obtain a proteomic portrait. Parallel reaction monitoring (PRM)-targeted proteomic and regression analyses were used to verify and select the diagnostic signatures. Finally, 14 proteins were selected and a panel of diagnostic classifiers (DLK1, SPTB/COL21A1, and SAR1A) was built to represent the CHM, PHM, and NC groups (auROC=0.900, 0.804/0.885, and 0.991, respectively). This high diagnostic power was further validated in another independent cohort (n = 148) by immunohistochemistry (IHC) (n = 120) and western blot (WB) analyses (n = 28). The protein SPTB was selected for further biological behaviour experiments in vitro. Our data suggest that SPTB maintains trophoblast cell proliferation, angiogenesis, cell motility and the cytoskeleton network. This study provides a comprehensive proteomic portrait and identifies potential diagnostic biomarkers. These findings enhance our understanding of EPL pathogenesis and offer novel targets for diagnosis and therapeutic interventions.

Involvement of mitochondrial DHODH and IFN-induced transmembrane protein in cell fusion during syncytialization of trophoblast cells

Involvement of mitochondrial DHODH and IFN-induced transmembrane protein in cell fusion during syncytialization of trophoblast cells

Novel extracellular nanoparticles secreted by human villous trophoblast cells influence peripheral blood mononuclear cells

Novel extracellular nanoparticles secreted by human villous trophoblast cells influence peripheral blood mononuclear cells

Interferon regulatory factor 1 mediated inhibition of Treg cell differentiation induces maternal-fetal immune imbalance in preeclampsia

The establishment and maintenance of a successful pregnancy rely heavily on maternal-fetal immune tolerance. Inflammatory and immune mechanisms during pregnancy bear a resemblance to those observed in tumor progression, with Treg cells exhibiting similar immunoregulatory functions in both contexts. Interferon regulatory factor 1 (IRF1) is implicated in modulating the immune milieu within tumors and influencing regulatory T (Treg) cell differentiation. However, the precise association between IRF1 and the onset of preeclampsia (PE) remains unclear. In our investigation, we identified trophoblasts as a significant source of IRF1 expression at the maternal-fetal interface through immunofluorescence analysis. Moreover, heightened levels of IRF1 expression were detected in both placental tissues and peripheral blood samples obtained from PE patients, concomitant with an imbalance in the Th17/Treg ratio. In the peripheral circulation, a notable inverse correlation was observed between IRF1 mRNA levels and Foxp3 mRNA, a transcription factor specific to Treg cells. IRF1 mRNA expression showed a positive association with systolic blood pressure and a negative association with serum albumin levels. Furthermore, co-culturing naïve T cells with supernatants from HTR-8/SV neo cells overexpressing IRF1 resulted in diminished differentiation of T cells into Treg cells. In summary, our study indicates elevated IRF1 expression in the peripheral blood and trophoblast cells of PE patients. Elevated IRF1 in trophoblast cells hinders the differentiation of maternal Treg cells, disrupting maternal-fetal immune tolerance and contributing to PE pathogenesis. Additionally, IRF1 expression correlates with disease severity, suggesting its potential as a novel sensitive target in PE.

Trophectoderm grade is associated with the risk of placenta previa in frozen-thawed single-blastocyst transfer cycles.

Do obstetric and perinatal complications vary according to different blastocyst developmental parameters after frozen-thawed single-blastocyst transfer (SBT) cycles? Pregnancies following the transfer of a blastocyst with a grade C trophectoderm (TE) were associated with an increased risk of placenta previa compared to those with a blastocyst of grade A TE. Existing studies investigating the effect of blastocyst morphology grades on birth outcomes have mostly focused on fetal growth and have produced conflicting results, while the risk of obstetric complications has rarely been reported. Additionally, growing evidence has suggested that the appearance of TE cells could serve as the most important parameter for predicting implantation and live birth. Given that the TE ultimately develops into the placenta, it is plausible that this independent predictor may also impact placentation. This retrospective cohort study at a tertiary-care academic medical center included 6018 singleton deliveries after frozen-thawed SBT cycles between January 2017 and December 2021. Singleton pregnancies were grouped into two groups according to blastocyst developmental stage (Days 5 and 6), four groups according to embryo expansion (Stages 3, 4, 5, and 6), three groups according to inner cell mass (ICM) quality (A, B, and C), and three groups according to TE quality (A, B, and C). The main outcomes included pregnancy-induced hypertension, preeclampsia, gestational diabetes mellitus, preterm premature rupture of membrane, placenta previa, placental abruption, placenta accreta, postpartum hemorrhage, preterm birth, low birth weight, small for gestational age, and birth defects. Multivariate logistic regressions were performed to evaluate the effect of blastocyst developmental stage, embryo expansion stage, ICM grade, and TE grade on measured outcomes adjusting for potential confounders. No association was found between blastocyst developmental stage and obstetric or perinatal outcomes both before and after adjusting for potential confounders, and similar results were found with regard to embryo expansion stage and ICM grade. Meanwhile, the incidence of placenta previa derived from a blastocyst with TE of grade C was higher compared with those derived from a blastocyst with TE of grade A (1.7%, 2.4%, and 4.0% for A, B, and C, respectively, P = 0.001 for all comparisons). After adjusting for potential covariates, TE grade C blastocysts had 2.81 times the likelihood of resulting in placenta previa compared to TE grade A blastocysts (adjusted odds ratio 2.81, 95% CI 1.11-7.09). No statistically significant differences were detected between any other measured outcomes and TE grades both before or after adjustment. The study is limited by its retrospective, single-center design. Additionally, although the sample size was relatively large for the study group, the sample size for certain subgroups was relatively small and lacked adequate power, particularly the ICM grade C group. Therefore, these results should be interpreted with caution. The study extends our knowledge of the potential downstream effect of TE grade on placental abnormalities. This study was supported by the National Key Research and Development Program of China (2023YFC2705500, 2023YFC2705501, 2023YFC2705505, 2019YFA0802604); National Natural Science Foundation of China (82130046, 82320108009, 82371660, 32300710); Shanghai leading talent program, Innovative research team of high-level local universities in Shanghai (SHSMU-ZLCX20210201, SHSMU-ZLCX20210200, SHSMU-ZLCX20180401), Shanghai Jiaotong University School of Medicine Affiliated Renji Hospital Clinical Research Innovation Cultivation Fund Program (RJPY-DZX-003), Science and Technology Commission of Shanghai Municipality (23Y11901400), Shanghai's Top Priority Research Center Construction Project (2023ZZ02002), and Three-Year Action Plan for Strengthening the Construction of the Public Health System in Shanghai (GWVI-11.1-36). The authors have no conflicts of interest to declare. N/A.

Overlapping peri-implantation phenotypes of ZNHIT1 and ZNHIT2 despite distinct functions during early mouse development.

Mammalian preimplantation development culminates in the formation of a blastocyst which undergoes extensive gene expression regulation to successfully implant into the maternal endometrium. Zinc-finger HIT domain-containing (ZNHIT) 1 and 2 are members of a highly conserved family, yet they have been identified as subunits of distinct complexes. Here we report that knockout of either Znhit1 or Znhit2 results in embryonic lethality during peri-implantation stages. Znhit1 and Znhit2 mutant embryos have overlapping phenotypes, including reduced proportion of SOX2-positive ICM cells, a lack of Fgf4 expression and aberrant expression of NANOG and SOX17. Furthermore, we find that the similar phenotypes are caused by distinct mechanisms. Specifically, embryos lacking ZNHIT1 likely fail to incorporate sufficient H2A.Z at the promoter region of Fgf4 and other genes involved in cell projection organization resulting in impaired invasion of trophoblast cells during implantation. In contrast, Znhit2 mutant embryos display a complete lack of nuclear EFTUD2, a key component of U5 spliceosome, indicating a global splicing deficiency. Our findings unveil the indispensable yet distinct roles of ZNHIT1 and ZNHIT2 in early mammalian embryonic development.

Differential effect of lead and cadmium on mitochondrial function and NLRP3 inflammasome activation in human trophoblast.

Heavy metals disrupt mitochondrial function and activate the NOD-like receptor pyrin-containing 3 (NLRP3) inflammasome. We investigated the effect of lead (Pb)/cadmium (Cd) on mitochondrial function and NLRP3 inflammasome activation in human trophoblast under normoxic, hypoxic and pro-inflammatory conditions. JEG-3, BeWo and HTR-8/SVneo cells were exposed to Pb or Cd for 24h in the absence or presence of hypoxia or pro-inflammatory lipopolysaccharide (LPS) or poly(I:C). Then, we evaluated cell viability, apoptosis, mitochondrial DNA copy number (mtDNAcn), mitochondrial membrane potential (ΔΨ), NLRP3 inflammasome proteins and interleukin (IL)-1β secretion. Although our data showed that Pb, Cd, hypoxia, poly(I:C) and LPS decreased mtDNAcn in the three cell lines, the effects of these treatments on other biomarkers were different in the different cell lines. We found that hypoxia decreased ΔΨ and promoted apoptosis in JEG-3 cells, increased ΔΨ and prevented apoptosis in BeWo cells, and did not change ΔΨ and apoptosis in HTR-8/SVneo cells. Moreover, Pb under hypoxic conditions reduced ΔΨ and promoted apoptosis of BeWo cells. Exposure of BeWo and HTR-8/SVneo cells to hypoxia, Pb or Cd alone upregulated the expression of NLRP3 and pro-caspase 1 but did not activate the NLRP3 inflammasome since cleaved-caspase 1 and IL-1β were not increased. To conclude, Pb and Cd affected trophoblast mitochondrial function and NLRP3 proteins in trophoblast cell lines, but in a cell line-specific way. KEY POINTS: The objective of this work was an understanding of the effect of lead (Pb) and cadmium (Cd) on mitochondrial function and NLRP3 inflammasome activation in human trophoblast cell lines under normoxic, hypoxic and pro-inflammatory conditions. Apoptosis of JEG-3 cells was increased by hypoxia, while in BeWo cells, apoptosis was decreased by hypoxia, and in HTR-8/SVneo, apoptosis was not affected by hypoxic treatment. Exposure to either Pb or Cd decreased mtDNAcn in three human placental trophoblast cell lines. However, Pb under hypoxia induced a decrease of ΔΨ and promoted apoptosis of BeWo cells, but Cd did not induce a reduction in ΔΨ in the three trophoblast cell lines under any conditions. Exposure to hypoxia, Pb or Cd increased NLRP3 and pro-caspase 1 in BeWo and HTR-8/SVneo cells. Our findings highlight that Pb and Cd affected trophoblast mitochondrial function and NLRP3 proteins in trophoblast cell lines but in a cell line-specific way.