Diminished trophoblast differentiation in early onset preeclampsia

The Role of Oxidative Stress-Induced Senescence in the Pathogenesis of Preeclampsia

Preeclampsia is a hypertension condition of human pregnancy that poses a significant risk to pregnant women and their fetus. It complicates about 2-8% of human pregnancies worldwide and displays multifactorial pathogenesis, including increased placental oxidative stress because of disturbed utero-placental blood flow. Recent evidence suggests that increased oxidative stress promotes acceleration of the placental senescence which is implicated in the pathogenesis of preeclampsia. This review focuses on the mechanisms that lead to oxidative stress in preeclamptic patients and examines the role of oxidative stress-induced placental senescence in the pathogenesis of the disease.

Type I interferon exposure of an implantation-on-a-chip device alters invasive extravillous trophoblast function

Inappropriate type I interferon (IFN) signaling during embryo implantation and placentation is linked to poor pregnancy outcomes. Here, we evaluate the consequence of elevated type I IFN exposure on implantation using a human implantation in an organ-on-a-chip device. We reveal that type I IFN reduces extravillous trophoblast (EVT) invasion capacity. Analyzing single-cell transcriptomes, we uncover that IFN truncates invasive EVT emergence in the implantation-on-a-chip device by stunting EVT epithelial-to-mesenchymal transition. Disruptions to the epithelial-to-mesenchymal transition are associated with the pathogenesis of preeclampsia, a life-threatening disorder of pregnancy. Strikingly, IFN stimulation induces genes associated with increased preeclampsia risk in EVTs. These dysregulated EVT phenotypes ultimately reduce EVT-mediated endothelial cell vascular remodeling in the implantation-on-a-chip device. Overall, our work implicates unwarranted type I IFN as a maternal disturbance that can result in abnormal EVT function that could trigger preeclampsia.

NAD+ depletion is central to placental dysfunction in an inflammatory subclass of preeclampsia

Preeclampsia (PE) is a hypertensive disorder of pregnancy and a major cause of maternal/perinatal adverse health outcomes with no effective therapeutic strategies. Our group previously identified distinct subclasses of PE, one of which exhibits heightened placental inflammation (inflammation-driven PE). In non-pregnant populations, chronic inflammation is associated with decreased levels of cellular NAD+, a vitamin B3 derivative involved in energy metabolism and mitochondrial function. Interestingly, specifically in placentas from women with inflammation-driven PE, we observed the increased activity of NAD+-consuming enzymes, decreased NAD+ content, decreased expression of mitochondrial proteins, and increased oxidative damage. HTR8 human trophoblasts likewise demonstrated increased NAD+-dependent ADP-ribosyltransferase (ART) activity, coupled with decreased mitochondrial respiration rates and invasive function under inflammatory conditions. Such adverse effects were attenuated by boosting cellular NAD+ levels with nicotinamide riboside (NR). Finally, in an LPS-induced rat model of inflammation-driven PE, NR administration (200 mg/kg/day) from gestational days 1-19 prevented maternal hypertension and fetal/placental growth restriction, improved placental mitochondrial function, and reduced inflammation and oxidative stress. This study demonstrates the critical role of NAD+ in maintaining placental function and identifies NAD+ boosting as a promising preventative strategy for PE.

KLF6 negatively regulates HIF-1α in extravillous trophoblasts under hypoxia

INTRODUCTION

HIF-1α, the master regulator of hypoxia cellular response, is stabilized under low oxygen levels and degraded in the presence of oxygen but its transcription, translation, and degradation are tightly regulated by numerous pathways. KLF6 is a transcription factor involved in proliferation, differentiation, and apoptosis in several cell systems. Under hypoxia it is upregulated in a HIF-1α-dependent manner in extravillous trophoblasts. Considering the importance of hypoxia modulation of EVT behavior through HIF1-α we aimed to study whether KLF6 modulates HIF-1α expression in HTR8/SVneo cells.

METHODS

HTR8/SVneo cells were cultured in a 1 % oxygen chamber or in 3D format where a spontaneous oxygen gradient is generated. qRT-PCR and Western blot were performed to analyze mRNA and protein expression, respectively. SiRNA, shRNA, or plasmids were used to down- or up-regulate gene expression. Wound healing assay was performed under hypoxia to evaluate migration. The NFκB pathway was modulated with dominant negative mutants and a chemical inhibitor. Cobalt chloride was used to block HIF-1α degradation.

RESULTS

KLF6 up- and down-regulation in HTR8/SVneo cells exposed to acute hypoxia revealed a negative regulation on HIF-1α. KLF6 silencing led to a partially HIF-1α-dependent increase in MMP9 and VEGF. The NF-κB pathway and HIF-1α degradation were involved in KLF6-dependent HIF-1α regulation. HTR8/SVneo-3D culture showed that KLF6 negatively regulates HIF-1α in a microenvironment with naturally generated hypoxia.

DISCUSSION

Present results reveal that KLF6 contributes to a fine tune modulation of HIF-1α level under hypoxia. Thus, sustaining a HIF-1α homeostatic level, KLF6 might contribute to control EVT adaptation to hypoxia.

Prenatal triphenyl phosphate exposure impairs placentation and induces preeclampsia-like symptoms in mice

Triphenyl phosphate (TPhP) is an organophosphate flame retardant that is widely used in many commercial products. The United States Environmental Protection Agency has listed TPhP as a priority compound that requires health risk assessment. We previously found that TPhP could accumulate in the placentae of mice and impair birth outcomes by activating peroxisome proliferator-activated receptor gamma (PPARγ) in the placental trophoblast. However, the underlying mechanism remains unknown. In this study, we used a mouse intrauterine exposure model and found that TPhP induced preeclampsia (PE)-like symptoms, including new on-set gestational hypertension and proteinuria. Immunofluorescence analysis showed that during placentation, PPARγ was mainly expressed in the labyrinth layer and decidua of the placenta. TPhP significantly decreased placental implantation depth and impeded uterine spiral artery remodeling by activating PPARγ. The results of the in vitro experiments confirmed that TPhP inhibited extravillous trophoblast (EVT) cell migration and invasion by activating PPARγ and inhibiting the PI3K-AKT signaling pathway. Overall, our data demonstrated that TPhP could activate PPARγ in EVT cells, inhibit cell migration and invasion, impede placental implantation and uterine spiral artery remodeling, then induce PE-like symptom and impair birth outcomes. Although the exposure doses used in this study was several orders of magnitude higher than human daily intake, our study highlights the placenta as a potential target organ of TPhP worthy of further research.

Epigenetic changes regulating the epithelial-mesenchymal transition in human trophoblast differentiation

The phenotype of human placental extravillous trophoblast (EVT) at the end of pregnancy reflects both first trimester differentiation from villous cytotrophoblast (CTB) and later gestational changes, including loss of proliferative and invasive capacity. Invasion abnormalities are central to two major placental pathologies, preeclampsia and placenta accreta spectrum, so characterization of the corresponding normal processes is crucial. In this report, our gene expression analysis, using purified human CTB and EVT cells, highlights an epithelial-mesenchymal transition (EMT) mechanism underlying CTB-EVT differentiation and provides a trophoblast-specific EMT signature. 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. However, a small subgroup of genes undergoes gains of methylation (GOM) in their regulatory regions or gene bodies, associated with differential mRNA expression (DE). Prominent in this GOM-DE group are genes involved in the EMT, including multiple canonical EMT markers and the EMT-linked transcription factor RUNX1, for which we demonstrate a functional role in modulating the migratory and invasive capacities of JEG3 trophoblast cells. This analysis of DE associated with locus-specific GOM, together with functional studies of an important GOM-DE gene, highlights epigenetically regulated genes and pathways acting in human EVT differentiation and invasion, with implications for obstetric disorders in which these processes are dysregulated.

Potential molecular mechanisms and clinical implications of piRNAs in preeclampsia: a review

Preeclampsia is a multisystem progressive condition and is one of the most serious complications of pregnancy. Owing to its unclear pathogenesis, there are no precise and effective therapeutic targets for preeclampsia, and the only available treatment strategy is to terminate the pregnancy and eliminate the clinical symptoms. In recent years, non-coding RNAs have become a hotspot in preeclampsia research and have shown promise as effective biomarkers for the early diagnosis of preeclampsia over conventional biochemical markers. PIWI-interacting RNAs, novel small non-coding RNA that interact with PIWI proteins, are involved in the pathogenesis of various diseases at the transcriptional or post-transcriptional level. However, the mechanisms underlying the role of PIWI-interacting RNAs in the pathogenesis of preeclampsia remain unclear. In this review, we discuss the findings of existing studies on PIWI-interacting RNA biogenesis, functions, and their possible roles in preeclampsia, providing novel insights into the potential application of PIWI-interacting RNAs in the early diagnosis and clinical treatment of preeclampsia.

Clinical value of serum SIRT1 combined with uterine hemodynamics in predicting disease severity and fetal growth restriction in preeclampsia

Background

To investigate the effect and correlation of serum SIRT1 combined with uterine hemodynamic parameters on disease severity and fetal uterine growth restriction in the progression of preeclampsia, and to evaluate its clinical value as potential markers.

Methods

A total of 100 patients with preeclampsia who were hospitalized in Qufu Normal University Hospital from June 2017 to June 2021 were selected as the research objects. According to the severity, they were divided into Mild group (62 cases) and Severe group (38 cases), and according to whether the fetal growth restriction was combined or not, they were divided into the Combined fetal growth restriction group (56 cases) and the Uncomplicated fetal growth restriction group (44 cases). Serum SIRT1 levels and uterine artery hemodynamic parameters were detected, and spearman analysis was used to evaluate the association of serum SIRT1 levels and uterine artery hemodynamic parameters (peak-to-trough ratio of arterial blood velocity, pulsatility index, resistance index) with disease severity (systolic blood pressure, diastolic blood pressure, and random urinary protein levels) and fetal growth restriction (femoral length, biparietal diameter, head circumference and neonatal weight); unsupervised PCA analysis, supervised PLS-DA analysis, Cluster heat map analysis, ROC curve and AUC analysis were used to evaluate the diagnostic value of serum SIRT1 levels combined with uterine artery hemodynamic parameters in the severity of disease and fetal growth restriction in patients with preeclampsia.

Results

Serum SIRT1 levels was decreased in patients with severe preeclampsia (p < 0.0001), arterial blood flow velocity peak-to-trough ratio, pulsatility index and resistance index were increased (p < 0.001; p < 0.0001), and serum SIRT1 levels and uterine artery hemodynamic parameters were closely related to disease severity (p < 0.001; p < 0.0001). In addition, the levels of serum SIRT1 in patients with preeclampsia combined with fetal growth restriction was decreased (p < 0.0001), the peak-to-trough ratio of arterial blood flow velocity, pulsatility index and resistance index were increased (p < 0.0001), and serum SIRT1 levels and uterine artery hemodynamics were closely related to fetal growth restriction (p < 0.0001). Unsupervised PCA analysis and supervised PLS-DA analysis showed that patients with different severity of disease and patients with or without fetal growth restriction were similar within groups, and there were significant differences between groups; cluster heat map analysis showed that mild and severe groups were stratified clustering, the combined fetal growth restriction group and the uncombined group were hierarchically clustered; ROC curve and AUC analysis showed that serum SIRT1 levels combined with uterine artery hemodynamic parameters had a significant effect on the severity of preeclampsia and whether combined with fetal growth restriction high diagnostic value.

Conclusions

Serum SIRT1 combined with uterine hemodynamic parameters in preeclampsia is closely related to disease severity and fetal growth restriction, and is expected to become potential biomarkers for early clinical intervention in patients.

Novel insights into the complex interplay of immune dysregulation and inflammatory biomarkers in preeclampsia and fetal growth restriction: A two-step Mendelian randomization analysis

Background

The relationship between genetic immune dysregulation and the occurrence of preeclampsia (PE) or PE with fetal growth restriction (PE with FGR) has yielded inconsistent findings, and the underlying mediators of this association remain elusive. We aimed to explore the causal impact of genetic immune dysregulation on the risk of PE or PE with FGR and to elucidate the role of specific transcriptomes in mediating this relationship.

Methods

A two-step Mendelian randomization (MR) analysis was performed to explore the link between immune dysregulation and PE or PE with FGR, as well as to identify potential inflammatory biomarkers that act as mediators. GWAS summary data for outcomes were obtained from the FinnGen dataset. The analyses encompassed five systemic immune-associated diseases, four chronic genital inflammatory diseases, and thirty-one inflammatory biomarkers. Summary-data-based MR (SMR) and HEIDI analysis were conducted to test whether the effect size of single nucleotide polymorphisms (SNPs) on outcomes was mediated by the expression of immune-associated genes.

Results

The primary univariable analysis revealed a significant positive correlation between systemic lupus erythematosus (SLE), type 1 diabetes (T1D), type 2 diabetes (T2D), and rheumatoid arthritis (RA) with the risk of PE or PE with FGR. Surprisingly, a counterintuitive finding showed a significant negative association between endometriosis of pelvic peritoneum (EMoP) and the risk of PE with FGR. None of the inflammatory factors had a causal relationship with PE or PE with FGR. However, there was a significant association between lymphocyte count and the risk of PE with FGR. Within the lymphocyte subset, both the proportion of Natural Killer (NK) cells and absolute counts of naïve CD4+ T cells demonstrated significant effects on the risk of PE with FGR. Two-step MR analysis underscored the genetically predicted lymphocyte count as a significant mediator between T1D and PE with FGR. Additionally, SMR analysis indicated the potential involvement of SH2B3 in the occurrence of PE with FGR.

Conclusions

Our findings provided substantial evidence of the underlying causal relationship between immune dysregulation and PE or PE with FGR and some of these diseases proved to accelerate immune cells disorders and then contribute to the risk of incident PE or PE with FGR.

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

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

Laminin switches terminal differentiation fate of human trophoblast stem cells under chemically defined culture conditions

Human trophoblast stem cells (hTSCs) have emerged as a powerful tool to model early placental development in vitro. Analogous to the epithelial cytotrophoblast in the placenta, hTSCs can differentiate into cells of the extravillous trophoblast (EVT) lineage or the multinucleate syncytiotrophoblast (STB). Here we present a chemically defined culture system for STB and EVT differentiation of hTSCs. Notably, in contrast to current approaches, we neither utilize forskolin for STB formation nor transforming growth factor-beta (TGFβ) inhibitors or a passage step for EVT differentiation. Strikingly, the presence of a single additional extracellular cue-laminin-111-switched the terminal differentiation of hTSCs from STB to the EVT lineage under these conditions. In the absence of laminin-111, STB formation occurred, with cell fusion comparable to that obtained with differentiation mediated by forskolin; however, in the presence of laminin-111, hTSCs differentiated to the EVT lineage. Protein expression of nuclear hypoxia-inducible factors (HIF1α and HIF2α) was upregulated during EVT differentiation mediated by laminin-111 exposure. A heterogeneous mixture of Notch1+ EVTs in colonies and HLA-G+ single-cell EVTs were obtained without a passage step, reminiscent of heterogeneity in vivo. Further analysis showed that inhibition of TGFβ signaling affected both STB and EVT differentiation mediated by laminin-111 exposure. TGFβ inhibition during EVT differentiation resulted in decreased HLA-G expression and increased Notch1 expression. On the other hand, TGFβ inhibition prevented STB formation. The chemically defined culture system for hTSC differentiation established herein facilitates quantitative analysis of heterogeneity that arises during hTSC differentiation and will enable mechanistic studies in vitro.

Clinical Value of Serum SIRT1 Combined with Uterine Hemodynamics in Predicting Disease Severity and Fetal Growth Restriction in Preeclampsia

Objective

The sirtuin regulator 1-related enzyme (SIRT1) has been shown to play an important role in various pathophysiological processes. Our aim was to investigate the effect and correlation of serum SIRT1 combined with uterine hemodynamic parameters on disease severity and fetal uterine growth restriction in the progression of preeclampsia and to evaluate its clinical value as a potential marker.

Methods

A total of 100 patients with preeclampsia who were hospitalized in Qufu Normal University Hospital from June 2017 to June 2021 were selected as the research objects. According to the severity, they were divided into the mild (62 cases) and severe groups (38 cases), and according to whether the fetal growth restriction was combined or not, they were divided into the combined fetal growth restriction group (56 cases) and the uncomplicated fetal growth restriction group (44 cases). Serum SIRT1 expression and uterine artery hemodynamic parameters were detected, and Spearman analysis was used to evaluate the association of serum SIRT1 expression and uterine artery hemodynamic parameters (the peak-to-trough ratio of arterial blood velocity, the pulsatility index, and the resistance index) with disease severity (systolic blood pressure, diastolic blood pressure, and random urinary protein levels) and fetal growth restriction (femoral length, biparietal diameter, head circumference, and neonatal weight); unsupervised principal component analysis (PCA), supervised partial least-squares discrimination analysis (PLS-DA), cluster heat map analysis, the receiver operating characteristic (ROC) curve, and the area under curve (AUC) were used to evaluate the diagnostic value of serum SIRT1 expression combined with uterine artery hemodynamic parameters in the severity of disease and fetal growth restriction in patients with preeclampsia.

Results

Compared with patients with mild preeclampsia, serum SIRT1 expression was lower in patients with severe preeclampsia (p < 0.0001), the arterial blood flow velocity peak-to-trough ratio, pulsatility index, and resistance index were higher (p < 0.001; p < 0.0001); and serum SIRT1 expression and uterine artery hemodynamic parameters were closely related to disease severity (p < 0.001; p < 0.0001). In addition, the expression of serum SIRT1 in patients with preeclampsia combined with fetal growth restriction was lower than patients without preeclampsia (p < 0.0001); the peak-to-trough ratio of arterial blood flow velocity, the pulsatility index, and the resistance index were higher (p < 0.0001); and serum SIRT1 expression and uterine artery hemodynamics were closely related to fetal growth restriction (p < 0.0001). Unsupervised PCA analysis and supervised PLS-DA analysis showed that patients with different severity of disease and patients with or without fetal growth restriction were similar within the groups, and there were significant differences between the groups; cluster heat map analysis showed that the mild and severe groups were stratified clustering, and the combined fetal growth restriction group and the uncombined group were hierarchically clustered; ROC curve showed that the AUC of serum SIRT1 expression combined with uterine artery hemodynamic parameters was 0.776 in identifying the severity of preeclampsia and 0.956 in identifying the preeclampsia complicated by fetal growth restriction.

Conclusion

Serum SIRT1 combined with uterine hemodynamic parameters in preeclampsia is closely related to disease severity and fetal growth restriction and is expected to become a potential biomarker for early clinical intervention in patients.

Human Leukocyte Antigen HLA-C, HLA-G, HLA-F and HLA-E placental profiles are altered in Early Severe Preeclampsia and Preterm Birth with Chorioamnionitis

BACKGROUND

The extravillous trophoblast expresses each of the non-classical MHC class I antigens - HLA-E, F, and G and a single classical class I antigen HLA-C. We recently demonstrated dynamic expression patterns of HLA-C, G and F during early EVT invasion and placentation.

OBJECTIVE

In this study we investigate the hypothesis that the immune inflammatory mediated complications of pregnancy such as early preeclampsia and preterm labor, may show altered expression profiles of non-classical HLA.

STUDY DESIGN

Real time q-PCR, western blot and immunohistochemistry were performed on placental villous tissues and basal plate sections from term non-laboring deliveries, preterm deliveries and severe early onset preeclampsia both with and without small for gestational age neonates.

RESULTS

HLA-G is strongly and exclusively expressed by the EVT within the placental basal plate and its levels increase in pregnancies complicated by severe early onset PE with SGA neonates as compared to healthy term controls. HLA-C shows a similar profile in the EVT of PE pregnancies, but significantly decreases in the villous placenta. HLA-F protein levels are decreased in both EVT and villous placenta of severe early onset PE pregnancies both with and without SGA babies as compared to Term and PTB deliveries. HLA-E decreases in blood vessels in placentas from PE pregnancies as compared to Term and PTB deliveries. HLA-F and HLA-C are increased in the placenta of PTBs with chorioamnionitis as compared to idiopathic PTB.

CONCLUSION

Dysregulation of placental HLA expression at the maternal fetal interface may contribute to the compromised maternal tolerance in PTB with chorioamnionitis and excessive maternal systemic inflammation associated with severe early onset PE.

Molecular regulation of trophoblast stem cell self-renewal and giant cell differentiation by the Hippo components YAP and LATS1

Background

Trophoblast stem cells (TSCs), the precursors of trophoblast cells of placenta, possess the potential to differentiate into various trophoblastic subtypes in vitro. Establishment of extraembryonic trophoblastic lineage is preceded by the “outside versus inside” positional information in preimplantation embryos, critically synchronized by the Hippo components. Abundant expression of Hippo effector YAP in TSCs and differentiated cells with paucity of information on Hippo regulation of TSC proliferation/differentiation led us test the hypothesis that Hippo dynamics is one of the regulators of  TSC proliferation/differentiation.

Methods

Blastocyst-derived murine TSCs were used. Dynamics of Hippo components were analyzed using immunofluorescence, western blotting, immunoprecipitation, qRT-PCR. Interaction studies were performed using full-length and deletion constructs. BrdU incorporation assay, flow cytometry-based polyploidy analysis and confocal microscopy were used to decipher the underlying mechanism.

Results

YAP translocates to the nucleus in TSCs and utilizes its WW₂ domain to interact with the PPQY motif of the stemness factor, CDX2. YAP limits TSC proliferation with associated effect on CDX2 target CyclinD1. Trophoblast giant cells (TGC) differentiation is associated with cytoplasmic retention of YAP, heightened pYAP^Ser127, decrease in the level of the core Hippo component, LATS1, which thereby impedes LATS1-LIMK2 association. Decreased LATS1-LIMK2 complex formation in TGCs was associated with elevated pLIMK2^Thr505 as well as its target pCOFILIN^Ser3. Precocious overexpression of LATS1 during trophoblast differentiation decreased TGC marker, Prl2c2, diminished pLIMK2^Thr505 and inactive COFILIN (pCOFILIN^Ser3) while COFILIN-phosphatase, CHRONOPHIN remained unchanged. LATS1 overexpression inhibited trophoblast endoreduplication with smaller-sized TGC-nuclei, lower ploidy level and disintegrated actin filaments. Inhibition of LIMK2 activity recapitulated the effects of LATS1 overexpression in trophoblast cells.

Conclusion

These results unveil a multilayered regulation of trophoblast self-renewal and differentiation by the Hippo components.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02844-w.