Amphiregulin regulates the production of human chorionic gonadotropin in trophoblasts

Gene expression profile of human placental villous pericytes in the first trimester - An analysis by single-cell RNA sequencing

Mesenchymal cells within theplacental villi play a crucial role in shaping the morphology of branching structures and driving the development of blood vessels. However, the markers and functions of placental villous pericytes (PVPs) as distinct subgroups of placental villous mesenchymal cells, remain unclear. Therefore, in this study, the markers and functions of PVPs were investigated. Single-cell sequencing data from the first-trimester placental villi was obtained and the Seurat tool was used to identify PVP markers. Gene Ontology (GO) analysis of specific genes was performed using the DAVID database. The Cellchat tool was employed to investigate the interaction signals between the PVPs and other cells. Expression of the PVP markers was confirmed using immunofluorescence. Presence of extracellular vesicles in the placental villous mesenchyme and PVPs was examined by transmission electron microscopy. Our findings revealed that renin (REN) and amphiregulin (AREG)-positive fibroblasts in the placental villi specifically expressed several classic pericyte markers. In the first trimester, certain conserved functions of pericytes were observed and they displayed tissue-specific functions such as in the integrin-mediated signaling pathway and extracellular exosomes. Moreover, the placental villous mesenchyme was found to be rich in extracellular vesicles. AREG is specifically transcribed in the first trimester PVPs, however, its protein was located in syncytiotrophoblasts. These insights contribute to a comprehensive understanding of early placental development and offer new therapeutic targets for placenta-derived pregnancy complications.

Investigation of Serum Amphiregulin Concentrations in Pregnant Women Diagnosed with Isolated Fetal Growth Restriction in the Third Trimester

OBJECTIVE

We aimed to investigate serum amphiregulin (AREG) concentrations in pregnant women with isolated fetal growth restriction (FGR) in the third trimester.

MATERIALS AND METHODS

This cross-sectional study was conducted with 90 pregnant women who applied to the Umraniye Training and Research Hospital Gynecology and Obstetrics Clinic between January 2022 and May 2022. The FGR group consisted of 45 pregnant women diagnosed with FGR in the third trimester, and the control group consisted of 45 healthy pregnant women matched with the FGR group in terms of age and body mass index (BMI). Demographic characteristics, ultrasound findings, and neonatal outcomes were noted. As a primary outcome, the two groups were compared for maternal serum AREG concentrations.

RESULTS

Both groups were similar in terms of demographic characteristics (p>0.05). While fetal BPD, AC, and FL measurements in the group diagnosed with FGR were significantly lower than in the control group, umbilical artery Doppler PI and S/D were higher (p=0.000, for all). Gestational age at birth, newborn birth weight, birth height, and 1-minute Apgar score were significantly lower and the NICU admission rate was higher in the FGR group (p=0.000, p=0.000, p=0.000, p=0.027, p=0.011 respectively). Gestational age at blood sampling for AREG was similar in both groups (p=0.869). While maternal serum AREG concentration was 969.39 ng/L in the FGR group, it was 795.20 ng/L in the control group (p=0.018). AUC analysis of AREG for estimation of FGR in ROC analysis was 0.57 (p<0.247, 95% CI=0.44-0.69). The optimal threshold value for FGR estimation of maternal serum AREG concentration was determined as 874.03 ng/L with 55% sensitivity and 55% specificity.

CONCLUSION

High maternal serum AREG concentrations appear to be associated with isolated FGR in the third trimester. The pathways through which AREG modulates fetal growth remain to be investigated.

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.

WNK1 mediates amphiregulin-induced MMP9 expression and cell invasion in human extravillous trophoblast cells

The invasion of human extravillous trophoblast (EVT) cells is a critical event required for a successful pregnancy. Amphiregulin, a ligand of the epidermal growth factor receptor (EGFR), has been shown to stimulate cell invasion in an immortalized human EVT cell line, HTR-8/SVneo. The with-no-lysine kinase 1 (WNK1) is involved in regulating cell invasion. It is known that WNK1 is expressed in the human placenta, but its role in human EVT cells remains unknown. In the present study, we show that AREG treatment phosphorylated WNK1 at Thr60 in both HTR-8/SVneo and primary human EVT cells. The stimulatory effect of AREG on WNK1 phosphorylation was mediated by the activation of PI3K/AKT, but not the ERK1/2 signaling pathway. AREG upregulated matrix metalloproteinase 9 (MMP9) but not MMP2. In addition, cell invasiveness was increased in response to the treatment of AREG. Using the siRNA-mediated knockdown approach, our results showed that the knockdown of WNK1 attenuated the AREG-induced upregulation of MMP9 expression and cell invasion. Moreover, the expression of WNK1 was downregulated in the placentas with preeclampsia, a disease resulting from insufficiency of EVT cell invasion during pregnancy. This study discovers the physiological function of WNK1 in human EVT cells and provides important insights into the regulation of MMP9 and cell invasion in human EVT cells.

Amphiregulin stimulates human chorionic gonadotropin expression by inducing ERK1/2-mediated ID3 expression in trophoblast cells

INTRODUCTION

The human chorionic gonadotropin (hCG) is a dimer consisting of an α subunit and a β subunit which is encoded by the CGB gene and is unique to hCG. hCG is a hormone mainly synthesized by syncytiotrophoblast cells in the placenta, plays a critical role in stimulating progesterone production that is necessary for maintaining normal pregnancy in the early stage. Epidermal growth factor receptor (EGFR) belongs to the receptor tyrosine kinase family which has been shown to regulate various physiological and pathological events. In human chorionic villi and amniotic fluid, amphiregulin (AREG) is reported to be the most abundant EGFR ligand and can stimulate hCG expression. However, the underlying mechanism remains unknown.

METHODS

We use BeWo cells, the commonly used cell model for the hCG production of trophoblast cells, as an in vitro model. The effects of AREG on CGB expression and hCG secretion as well as the underlying mechanisms were explored by a series of in vitro experiments.

RESULTS

We show that treatment with AREG stimulates CGB expression and hCG secretion. Using pharmacological inhibitors, we show that the stimulatory effects of AREG on CGB expression and hCG secretion are mediated by the EGFR-activated ERK1/2 signaling pathways. In addition, the expression of inhibitor of DNA-binding protein 3 (ID3) is upregulated by AREG. Knockdown of ID3 attenuates the AREG-induced upregulation of CGB expression and hCG secretion.

DISCUSSION

This study provides important insights into the molecular mechanisms that mediate AREG-induced upregulation of hCG production in human trophoblast cells which may lead to the development of alternative therapeutic approaches for the treatment of placental diseases.

Amphiregulin enhances intercellular adhesion molecule-1 expression and promotes tumor metastasis in human osteosarcoma

Osteosarcoma is a common, high malignant, and metastatic bone cancer. Amphiregulin (AREG) has been associated with cancer cellular activities. However, the effect of AREG on metastasis activity in human osteosarcoma cells has yet to be determined. We determined that AREG increases the expression of intercellular adhesion molecule-1 (ICAM-1) through PI3K/Akt signaling pathway via its interaction with the epidermal growth factor receptor, thus resulting in the enhanced cell migration of osteosarcoma. Furthermore, AREG stimulation increased the association of NF-κB to ICAM-1 promoter which then up-regulated ICAM-1 expression. Finally, we observed that shRNA silencing of AREG decreased osteosarcoma metastasis in vivo. Our findings revealed a relationship between osteosarcoma metastatic potential and AREG expression and the modulating effect of AREG on ICAM-1 expression.

An in vitro high-throughput assay for screening reproductive and toxic effects of anticancer compounds

An in vitro assay was developed that simultaneously tested the effects of anticancer drug candidates on cytotoxicity, hormone synthesis, and gonadotrophin responsiveness using the choriocarcinoma JAr cell line. JAr culture conditions were optimized and then cells were exposed to a marine mollusc extract in the presence and absence of hCG. The intra- and interassay coefficients of variation of the optimized 1 H thiazolyl blue tetrazolium bromide assay were 11.3% and 10.9%, respectively. hCG (1,000 mIU/mL) increased progesterone (P4) synthesis after 24 H (P<0.05). The mollusc extract significantly decreased cell viability, with the IC50 affected by incubation time, but not hCG. P4 synthesis was inhibited at low concentrations of the anticancer extract, but stimulated at the highest concentration, and complex interactions of P4 were also found with hCG. In conclusion, the optimized assay is useful to characterize the effects of novel drugs on cytotoxicity, basal, and gonadotrophin-stimulated P4 synthesis in vitro, and can be used to inform subsequent in vivo studies.

Expression of epidermal growth factor receptors and epidermal growth factor, amphiregulin and neuregulin in bovine uteroplacental tissues during gestation

INTRODUCTION

Growth factors are proteins that bind to specific cell surface receptors that initiate signalling pathways and result in proliferation or differentiation of the affected cells. During gestation, epidermal growth factor receptors (ErbB1-4) and its ligands (epidermal growth factor-EGF, amphiregulin-AREG, neuregulin1-NRG1) play a significant role in differentiation, function and growth of the uterus.

OBJECTIVES

To determine the role of ErbB receptors and EGF, AREG and NRG1 in bovine uteroplacental tissues during gestation.

METHODS

Placentomes and interplacentomal areas from 30 cows from early gestation until near term were analysed by immunohistochemistry.

RESULTS

ErbB receptors and its ligands were observed in uteroplacental tissues and its expression was maintained throughout pregnancy, but ErbB1 receptor did not exist in the caruncular and cotyledonary stromal cells. Besides, caruncular stromal cells did not present with any immune reaction for EGF, AREG and NRG1. Generally, it was observed that total scores for ErbB receptors and its ligands (EGF, AREG and NRG1) had decreased from early to late gestation (p < 0.05).

CONCLUSION

Our study shows the presence of ErbB receptors and its ligands participate in the mid- and late-phases of pregnancy. To our knowledge, this is the first study on the expression of NRG1 during bovine pregnancy. These results indicates that these factors may play a crucial role not only to enable cellular proliferation and differentiation in the uterus throughout gestation, but also to have a potential role in the cellular communication maintained between the embryo/fetus and uterus by the placenta.

The tyrosine phosphatase SHP-1 negatively regulates cytotrophoblast proliferation in first-trimester human placenta by modulating EGFR activation

Insulin-like growth factors (IGFs) influence placental cell (cytotrophoblast) kinetics. We recently reported that the protein tyrosine phosphatase (PTP) SHP-2 positively regulates IGF actions in the placenta. In other systems, the closely related PTP, SHP-1, functions as a negative regulator of signaling events but its role in the placenta is still unknown. We examined the hypothesis that SHP-1 negatively regulates IGF actions in the human placenta. Immunohistochemical (IHC) analysis demonstrated that SHP-1 is abundant in cytotrophoblast. SHP-1 expression was decreased in first-trimester placental explants using siRNA; knockdown did not alter IGF-induced proliferation but it significantly enhanced proliferation in serum-free conditions, revealing that placental growth is endogenously regulated. Candidate regulators were determined by using antibody arrays, Western blotting, and IHC to examine the activation status of multiple receptor tyrosine kinases (RTKs) in SHP-1-depleted explants; amongst the alterations observed was enhanced activation of EGFR, suggesting that SHP-1 may interact with EGFR to inhibit proliferation. The EGFR tyrosine kinase inhibitor PD153035 reversed the elevated proliferation seen in the absence of SHP-1. This study demonstrates a role for SHP-1 in human trophoblast turnover and establishes SHP-1 as a negative regulator of EGFR activation. Targeting placental SHP-1 expression may provide therapeutic benefits in common pregnancy conditions with abnormal trophoblast proliferation.