Role of estrogen in regulation of cellular differentiation: a study using human placental and rat Leydig cells

Differential response of placental cells to high D-glucose and its impact on extracellular vesicle biogenesis and trafficking via small GTPase Ras-related protein RAB-7A

Placental extracellular vesicles (EVs) can be found in the maternal circulation throughout gestation, and their concentration, content and bioactivity are associated with pregnancy outcomes, including gestational diabetes mellitus (GDM). However, the effect of changes in the maternal microenvironment on the mechanisms associated with the secretion of EVs from placental cells remains to be fully established. Here, we evaluated the effect of high glucose on proteins associated with the trafficking and release of different populations of EVs from placental cells. BeWo and HTR8/SVneo cells were used as placental models and cultured under 5-mM D-glucose (i.e. control) or 25-mM D-glucose (high glucose). Cell-conditioned media (CCM) and cell lysate were collected after 48 h. Different populations of EVs were isolated from CCM by ultracentrifugation (i.e. pellet 2K-g, pellet 10K-g, and pellet 100K-g) and characterised by Nanoparticle Tracking Analysis. Quantitative proteomic analysis (IDA/SWATH) and multiple reaction monitoring protocols at high resolution (MRMHR) were developed to quantify 37 proteins related to biogenesis, trafficking/release and recognition/uptake of EVs. High glucose increased the secretion of total EVs across the pellets from BeWo cells, an effect driven mainly by changes in the small EVs concentration in the CCM. Interestingly, no effect of high glucose on HTR8/SVneo cells EVs secretion was observed. High glucose induces changes in proteins associated with vesicle trafficking in BeWo cells, including Heat Shock Protein Family A (Hsp70) Member 9 (HSPA9) and Member 8 (HSPA8). For HTR8/SVneo, altered proteins including prostaglandin F2α receptor regulatory protein (FPRP), RAB5A, RAB35, RAB5B, and RB11B, STAM1 and TSG101. These proteins are associated with the secretion and trafficking of EVs, which could explain in part, changes in the levels of circulating EVs in diabetic pregnancies. Further, we identified that proteins RAB11B, PDCD6IP, STAM, HSPA9, HSPA8, SDCBP, RAB5B, RAB5A, RAB7A and ERAP1 regulate EV release in response to high and low glucose when overexpressed in cells. Interestingly, immunohistochemistry analysis of RAB7A revealed distinct changes in placental tissues obtained from women with normal glucose tolerance (NGT, n = 6) and those with GDM (n = 6), influenced by diet or insulin treatment. High glucose regulation of proteins involved in intercellular dynamics and the trafficking of multivesicular bodies to the plasma membrane in placental cells is relevant in the context of GDM pregnancies.

Serotonin-estrogen interactions: What can we learn from pregnancy?

We have reviewed the scientific literature related to four diseases in which to serotonin (5-HT) is involved in the etiology, herein named 5-HT-linked diseases, and whose prevalence is influenced by estrogenic status: depression, migraine, irritable bowel syndrome and eating disorders. These diseases all have in common a sex-dimorphic prevalence, with women more frequently affected than men. The co-occurrence between these 5-HT-linked diseases suggests that they have common physiopathological mechanisms. In most 5-HT-linked diseases (except for anorexia nervosa and irritable bowel syndrome), a decrease in the serotonergic tone is observed and estrogens are thought to contribute to the improvement of symptoms by stimulating the serotonergic system. Human pregnancy is characterized by a unique 5-HT and estrogen synthesis by the placenta. Pregnancy-specific disorders, such as hyperemesis gravidarum, gestational diabetes mellitus and pre-eclampsia, are associated with a hyperserotonergic state and decreased estrogen levels. Fetal programming of 5-HT-linked diseases is a complex phenomenon that involves notably fetal-sex differences, which suggest the implication of sex steroids. From a mechanistic point of view, we hypothesize that estrogens regulate the serotonergic system, resulting in a protective effect against 5-HT-linked diseases, but that, in turn, 5-HT affects estrogen synthesis in an attempt to retrieve homeostasis. These two processes (5-HT and estrogen biosynthesis) are crucial for successful pregnancy outcomes, and thus, a disruption of this 5-HT-estrogen relationship may explain pregnancy-specific pathologies or pregnancy complications associated with 5-HT-linked diseases.

Profile of CYP19A1 mRNA expression and aromatase activity during syncytialization of primary human villous trophoblast cells at term

Estrogen production by the human villous trophoblast is dependent on the biosynthetic enzyme aromatase (CYP19; CYP19A1) and is crucial for successful placental development and pregnancy outcome. Using villous cytotrophoblast cells (vCTs) freshly isolated from normal term placenta, we characterized the promoter-specific expression of CYP19A1 mRNA (derived from promoters I.1, I.4, I.8 or total transcript) and aromatase activity during villous trophoblast syncytialization. CYP19A1 mRNA levels and aromatase activity in vCTs reached a maximum after about 48 h of culture. The cAMP inducer forskolin (10 μM) and protein kinase C stimulant phorbol myristate acetate (1 μM) increased CYP19A1 mRNA levels by 1.8- and 1.6-fold, respectively, as well as inducing aromatase catalytic activity. Dexamethasone (100 nM) and vascular endothelial growth factor (5 ng/mL) decreased CYP19A1 mRNA levels, while having no effect on aromatase activity. Our results emphasize the importance of not solely studying CYP19A1 regulation and function at the mRNA level but also considering posttranslational mechanisms that alter the final catalytic activity of aromatase.

The xenoestrogens, bisphenol A and para-nonylphenol, decrease the expression of the ABCG2 transporter protein in human term placental explant cultures

Many endogenous and xenobiotic compounds are substrates and regulators of human placental ABC transporters. ABCG2 is protecting fetus against foreign chemicals. Environmental xenoestrogens, like bisphenol A (BPA) and p-nonylphenol (p-NP), mimic natural estrogens and can affect hormonal systems. Effects of BPA, p-NP, DES (diethylstilbestrol) and estradiol (E2), on ABCG2 expression were studied using human first trimester and term placental explants. Role of estrogen receptors (ER) in the effects of chemicals was studied by ER antagonist. Term placenta expressed less ABCG2 protein. In term placentas BPA (p < 0.05), p-NP (p < 0.01) and E2 (p < 0.05) decreased the ABCG2 protein expression after 48 h exposure while after 24 h exposure, only E2 decreased the expression (p < 0.05). The chemicals did not affect ABCG2 in first trimester placentas. The ER antagonist affected differently the responses of chemicals. In conclusion, environmental xenoestrogens downregulate placental ABCG2 protein expression depending on gestational age.

Placental development during early pregnancy in sheep: estrogen and progesterone receptor messenger RNA expression in pregnancies derived from in vivo-produced and in vitro-produced embryos

Sex steroids are important regulators of angiogenesis and growth in reproductive tissues, including the placenta. In experiment (exp.) 1, to examine the expression of a suite of sex steroid receptors throughout early pregnancy, maternal (caruncular [CAR]) and fetal (fetal membranes [FM]) placental tissues were collected on days 14 to 30 after mating and on day 10 after estrus (nonpregnant controls). In exp. 2, to examine the hypothesis that assisted reproductive technology would affect the expression of the same suite of sex steroid receptors, pregnancies were achieved through natural mating (NAT) or transfer of embryos from natural mating (NAT-ET), in vitro fertilization (IVF), or in vitro activation (IVA), and CAR and FM were collected on day 22. In exp. 1, for CAR messenger RNA (mRNA) expression of estrogen receptors (ESR) 1 and 2, nuclear (n) progesterone receptors (PGR) and membrane (m) PGRα, β, and γ were affected (P < 0.02) by pregnancy stage, as were ESR1, nPGR, and mPGRα, β, and γ for FM (P < 0.03). In exp. 2, for CAR, mRNA expression of ESR1 and nPGR was decreased (P < 0.001) in NAT-ET, IVF, and IVA groups compared with NAT. For FM, mRNA expression of ESR1 tended to be greater (P = 0.10) in the IVA group compared with NAT and NAT-ET, and GPER1 was greater (P < 0.05) in NAT-ET and IVF compared with NAT. These data establish the normal pattern of sex steroid receptor mRNA expression in maternal and fetal placenta during early pregnancy in sheep, and in addition, suggest that altered expression of placental sex steroid receptors may be an early event leading to poor placental vascularization and growth after assisted reproductive technology.

Reduction of progesterone, estradiol and hCG secretion by perfluorooctane sulfonate via induction of apoptosis in human placental syncytiotrophoblasts

INTRODUCTION

Perfluorooctane sulfonate (PFOS) is widely used as surfactants, lubricants, adhesives, fire retardants and propellants. Animal experiments have shown that PFOS can potentially influence reproductive function. The objective of the present study was to investigate the effects of PFOS on the endocrine function of human placental syncytiotrophoblasts.

METHODS

Primary human placental cytotrophoblasts were isolated from term placenta. After syncytialization, the levels of aromatase and apoptosis-related proteins including caspase3, Bcl-2 and Bax were examined after treatment with PFOS from 0.0001 μM to 1 μM or PFOS (0.1 μM) in the presence and absence of apoptosis inhibitor Z-VAD-FMK (30 μM) for 24 h.

RESULTS

PFOS suppressed aromatase level and the secretion of estradiol, hCG and progesterone in a concentration-dependent manner from 0.0001 μM to 1 μM with a significant inhibition at 0.001 μM and above in human placental syncytiotrophoblasts. Furthermore PFOS reduced cell viability and induced apoptosis in human placental syncytiotrophoblasts as revealed by increases of pro-apoptosis proteins such as Bax and cleaved-caspase3, and decreases of pro-caspase3 and anti-apoptosis protein Bcl-2. The apoptosis induced by PFOS was further illustrated by increased DNA fragmentation and nuclear condensation. Blocking apoptosis with pan-caspase inhibitor Z-VAD-FMK, the impairment of placental endocrine function by PFOS was restored.

DISCUSSION

These results indicate that PFOS may disrupt the secretion of hCG, progesterone and estradiol by human placental syncytiotrophoblasts via induction of apoptosis.

A unique co-culture model for fundamental and applied studies of human fetoplacental steroidogenesis and interference by environmental chemicals

BACKGROUND

Experimental tools for studying the complex steroidogenic interactions that occur between placenta and fetus during human pregnancy are extremely limited.

OBJECTIVES

We aimed to develop a co-culture model to study steroidogenesis by the human fetoplacental unit and its disruption by exposure to environmental contaminants.

METHODS

We cultured BeWo human choriocarcinoma cells, representing the villous cytotrophoblast, and H295R human adrenocortical carcinoma cells, representing the fetal unit, in a carefully adapted co-culture medium. We placed H295R cells in 24-well plates and BeWo cells on transwell inserts with or without pesticide treatment (atrazine or prochloraz) and assessed CYP19 activity and hormonal production after 24 hr of co-culture.

RESULTS

The co-culture exhibited the steroidogenic profile of the fetoplacental unit, allowing a synergistic production of estradiol and estriol (but not of estrone) of 133.3 ± 11.3 pg/mL and 440.8 ± 44.0 pg/mL, respectively. Atrazine and prochloraz had cell-type specific effects on CYP19 activity and estrogen production in co-culture. Atrazine induced CYP19 activity and estrogen production in H295R cells only, but did not affect overall estrogen production in co-culture, whereas prochloraz inhibited CYP19 activity exclusively in BeWo cells and reduced estrogen production in co-culture by almost 90%. In contrast, prochloraz did not affect estradiol or estrone production in BeWo cells in monoculture. These differential effects underline the relevance of our co-culture approach to model fetoplacental steroidogenesis.

CONCLUSIONS

The co-culture of H295R and BeWo cells creates a unique in vitro model to reproduce the steroidogenic cooperation between fetus and placenta during pregnancy and can be used to study the endocrine-disrupting effects of environmental chemicals.

Distinct properties of cell-type-specific and shared transcription factor binding sites

Most human transcription factors bind a small subset of potential genomic sites and often use different subsets in different cell types. To identify mechanisms that govern cell-type-specific transcription factor binding, we used an integrative approach to study estrogen receptor α (ER). We found that ER exhibits two distinct modes of binding. Shared sites, bound in multiple cell types, are characterized by high-affinity estrogen response elements (EREs), inaccessible chromatin, and a lack of DNA methylation, while cell-specific sites are characterized by a lack of EREs, co-occurrence with other transcription factors, and cell-type-specific chromatin accessibility and DNA methylation. These observations enabled accurate quantitative models of ER binding that suggest tethering of ER to one-third of cell-specific sites. The distinct properties of cell-specific binding were also observed with glucocorticoid receptor and for ER in primary mouse tissues, representing an elegant genomic encoding scheme for generating cell-type-specific gene regulation.

Identification of CD147 (basigin) as a mediator of trophoblast functions

STUDY QUESTION

Does CD147 regulate trophoblast functions in vitro?

SUMMARY ANSWER

CD147 exists as a receptor complex on human trophoblast and regulates the implantation, invasion and differentiation of trophoblast.

WHAT IS KNOWN ALREADY

CD147 is a membrane protein implicated in a variety of physiological and pathological conditions due to its regulation of cell-cell recognition, cell differentiation and tissue remodeling. Reduced placental CD147 expression is associated with pre-eclampsia, but the mechanism of actions remains unclear.

STUDY DESIGN, SIZE, DURATION

A loss of function approach or functional blocking antibody was used to study the function of CD147 in primary human cytotrophoblasts isolated from first trimester termination of pregnancy and/or in the BeWo cell line, which possesses characteristics of human cytotrophoblasts.

PARTICIPANTS/MATERIALS, SETTING METHODS

CD147 expression was analyzed by immunofluorescence staining and western blotting. CD147-associated protein complex on plasma membrane were separated by blue native gel electrophoresis and identified by reversed-phase liquid chromatography coupled with quadrupole time-of-flight hybrid mass spectrometer. Cell proliferation and invasion were determined by fluorometric cell proliferation assays and transwell invasion assays, respectively. Matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA) activities were measured by gelatin gel zymography and uPA assay kits, respectively. Cell migration was determined by wound-healing assays. Cell fusion was analyzed by immunocytochemistry staining of E-cadherin and 4',6-diamidino-2-phenylindole. The transcripts of matrix proteinases and trophoblast lineage markers were measured by quantitative PCR. Extracellular signal-regulated kinase (ERK) activation was analyzed by western blot using antibodies against ERKs.

MAIN RESULTS AND THE ROLE OF CHANCE

CD147 exists as protein complexes on the plasma membrane of primary human cytotrophoblasts and BeWo cells. Several known CD147-interacting partners, including integrin β1 and monocarboxylate transporter-1, were identified. Suppression of CD147 by siRNA significantly (P < 0.05) reduced trophoblast-endometrial cell interaction, cell invasion, syncytialization, differentiation and ERK activation of BeWo cells. Consistently, anti-CD147 functional blocking antibody suppressed the invasiveness of primary human cytotrophoblasts. The reduced invasiveness was probably due to the restrained (P < 0.05) enzyme activities of MMP-2, MMP-9 and uPA.

LIMITATIONS, REASONS FOR CAUTION

Most of the above findings are based on BeWo cell lines. These results need to be confirmed with human first trimester primary cytotrophoblast.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study on the role of CD147 in trophoblast function. Further investigation on the function of CD147 and its associated protein complexes will enhance our understanding on human placentation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by the University of Hong Kong Grant 201011159200. The authors have no competing interests to declare.

17-β-Estradiol counteracts the effects of high frequency electromagnetic fields on trophoblastic connexins and integrins

We investigated the effect of high-frequency electromagnetic fields (HF-EMFs) and 17-β-estradiol on connexins (Cxs), integrins (Ints), and estrogen receptor (ER) expression, as well as on ultrastructure of trophoblast-derived HTR-8/SVneo cells. HF-EMF, 17-β-estradiol, and their combination induced an increase of Cx40 and Cx43 mRNA expression. HF-EMF decreased Int alpha1 and β1 mRNA levels but enhanced Int alpha5 mRNA expression. All the Ints mRNA expressions were increased by 17-β-estradiol and exposure to both stimuli. ER-β mRNA was reduced by HF-EMF but augmented by 17-β-estradiol alone or with HF-EMF. ER-β immunofluorescence showed a cytoplasmic localization in sham and HF-EMF exposed cells which became nuclear after treatment with hormone or both stimuli. Electron microscopy evidenced a loss of cellular contact in exposed cells which appeared counteracted by 17-β-estradiol. We demonstrate that 17-β-estradiol modulates Cxs and Ints as well as ER-β expression induced by HF-EMF, suggesting an influence of both stimuli on trophoblast differentiation and migration.

Insulin-like growth factor binding protein 7 modulates estrogen-induced trophoblast proliferation and invasion in HTR-8 and JEG-3 cells

Previous research has reported that IGFBP7 functions as a tumor suppressor gene in different tumors, but its role in the trophoblast has not been elucidated. In this research, we studied the regulation mechanism of IGFBP7 in trophoblast proliferation and invasion in HTR-8 and JEG-3 cell lines. We found that IGFBP7 was abundantly expressed in normal human syncytiotrophoblast tissue samples but that this was lacking in hydatidiform moles. The proliferation and invasion capacities of HTR-8 and JEG-3 cells were significantly inhibited by recombinant IGFBP7. Estrogen (E2) stimulated the expression of IGFBP7 at a concentration of 5-10 ng/mL. This stimulation was inhibited by the estrogen receptor antagonist Fulvestrant (ICI182.780) and a TGFβ-neutralizing antibody. In conclusion, our data reveals that estrogen stimulates the expression of IGFBP7 through estrogen receptors and TGFβ. The expression of IGFBP7 could be stimulated by TGFβ in a dose-dependent manner and inhibited by IFNγ in HTR-8 and JEG-3 cells. IGFBP7 could also inhibit the phosphorylation of ERK and the expression of PCNA, MMP2 and MMP9 in HTR-8 and JEG-3 cells. These findings suggest that IGFBP7 is a key regulator of E2-induced trophoblast proliferation and invasion.

Stimulation of serotonergic 5-HT2A receptor signaling increases placental aromatase (CYP19) activity and expression in BeWo and JEG-3 human choriocarcinoma cells

It is known that serotonin can influence the production and function of sex hormones, such as estrogens. Estrogens are critical for maintenance of pregnancy and regulate placental and fetal development. The key enzyme controlling estrogens synthesis during pregnancy is placental aromatase (CYP19). To better understand the regulation of placental aromatase, this study determined whether serotonin is involved in the regulation of this enzyme. BeWo and JEG-3 choriocarcinoma cells were used as models of the human placental trophoblast to evaluate the effects of serotonin and selective 5-HT(2A) receptor agonists on CYP19 activity and expression. Serotonin and selective 5-HT(2A) receptor agonists as well as PKC activation increased aromatase activity and expression in BeWo and JEG-3 cells. Dexamethasone, which regulates aromatase expression via JAK/STAT activation in certain tissues, had no effect. Increased CYP19 gene transcription by 5-HT(2A) receptor and PKC stimulation was mediated by activation of the placental I.1 aromatase promoter. This study shows that the serotonergic system modulates placental aromatase expression, which would result in altered estrogens biosynthesis in trophoblast cells. Future detailed studies of serotonin-estrogen interactions in placenta are crucial for an improved understanding of the endo-, para- and autocrine role of serotonin during pregnancy and fetal development.

The contribution of lower vertebrate animal models in human reproduction research

Many advances have been carried out on the estrogens, GnRH and endocannabinoid system that have impact in the reproductive field. Indeed, estrogens, the generally accepted female hormones, have performed an unsuspected role in male sexual functions thanks to studies on non-mammalian vertebrates. Similarly, these animal models have provided important contributions to the identification of several GnRH ligand and receptor variants and their possible involvement in sexual behavior and gonadal function regulation. Moreover, the use of non-mammalian animal models has contributed to a better comprehension about the endocannabinoid system action in several mammalian reproductive events. We wish to highlight here how non-mammalian vertebrate animal model research contributes to advancements with implications on human health as well as providing a phylogenetic perspective on the evolution of reproductive systems in vertebrates.

A comprehensive survey of the laminins and collagens type IV expressed in mouse Leydig cells and their regulation by LH/hCG

Extracellular matrix (ECM) proteins have been shown to alter Leydig cell steroidogenesis in vitro, substantiating the hypothesis that Leydig cell steroidogenic activity and matrix environment are interdependent events. However, the nature of the ECM components synthesized by Leydig cells and their regulation by LH/human chorionic gonadotropin (hCG) remain unknown. Here, we examine the occurrence of the 11 laminin subunits and the 6 alpha chains of collagen IV (COL4A1-6) by RT-PCR in Leydig cells cultured with or without LH/hCG. Leydig cells were a tumor Leydig cell line (mLTC-1) or 8-week-old mice Leydig cells. Based on PCR data, it is suggested that normal Leydig cells may synthesize a maximum of 11 laminin heterotrimers and the 6 alpha chains of collagen IV. They also may synthesize various proteases and inhibitors of the metzincin family. The mLTC-1 cells have a limited repertoire as compared with normal Leydig cells. Interestingly, none of the ten proteases and inhibitors monitored is under LH-hCG regulation whereas every protease and inhibitor of the serine protease family yet identified in Leydig cells is under gonadotropin regulation. In addition, a few laminin and collagen subunit genes are regulated by LH/hCG. These are laminins alpha3 and gamma3 (Lama3 and Lamc3), Col4a3, and Col4a6, which are negatively regulated by LH/hCG in both Leydig cell types, and Col4a4, which was downregulated in primary cultures but not in mLTC-1 cells. Collectively, the present study suggests that Leydig cells modulate in a selective fashion their matrix environment in response to their trophic hormone. This may alter the steroidogenic outcome of Leydig cells.

Blastocyst-derived trophoblast stem cells from the rhesus monkey

Although trophoblast stem cells can be obtained directly from blastocyst outgrowths in the mouse, this has never been described in primates. In human and non-human primates, trophoblast cells have been obtained from embryonic stem (ES) cells or embryoid bodies (EBs). The results reported here show for the first time that cells with the characteristics of trophoblast stem cells can be derived directly from rhesus monkey blastocyst outgrowths. The cells expressed trophoblast markers and were maintained for multiple passages in the absence of feeder layers or growth factors. The cells could be maintained as adherent, mononuclear cells by regular passaging, but they formed syncytial-like structures if maintained in culture for prolonged periods or if incubated in the presence of 17beta-estradiol. The cells also demonstrated invasive behavior similar to extravillous trophoblasts. The availability of these lines provides a useful experimental system for studying trophoblast differentiation and for developing novel intervention strategies to treat placental dysfunction.

Molecular insight in cancer treatment and prevention

This article explores the impact of new insights in the biology of cancer on the treatment and the prevention of this disease. There are two types of targeted cancer treatment, afforded by the molecular profile of cancer. One concerns the use of agents targeted on a specific component of the cancer cells (e.g., CD20 in lymphoma) or on a specific survival function of the cancer cell (growth-factor-receptor interaction; transduction cascade). The other concerns the recognition of tumors that are more or less likely to benefit from cytotoxic chemotherapy according to their genomic or proteomic profile. Cancer prevention may benefit from new molecular insight in cancer biology as these processes allow early diagnosis of cancer, identification of patients at risk for cancer, and may provide intermediate markers for chemoprevention studies.

Proteomic profiling of forskolin-induced differentiated BeWo cells: an in-vitro model of cytotrophoblast differentiation

Placental trophoblastic differentiation is characterized by the fusion of monolayer cytotrophoblasts into syncytiotrophoblasts. During this process of differentiation, several morphological and biochemical changes are known to occur, and this model has been employed to investigate the changes that occur at the gene and protein level during differentiation. Using the sensitive technique of proteomics [two-dimensional gel electrophoresis (2DGE)], changes in protein profile were evaluated in the control and forskolin-induced differentiated cells of trophoblastic choriocarcinoma BeWo cell line. Several proteins were differentially expressed in control and differentiated cells. Four major proteins were up-regulated as assessed by silver staining, and were further characterized as c-h-ras p 21 (phosphorylated), retinoblastoma susceptibility protein 1 and integrase interactor protein 1. These proteins are known to play an important role in growth arrest of cells, and thus may play a role in initiating the process of differentiation.

Independent Regulation of Apical and Basolateral Drug Transporter Expression and Function in Placental Trophoblasts by Cytokines, Steroids, and Growth Factors

Placental ATP binding cassette (ABC) transporters protect placental and fetal tissues by effluxing xenobiotics and endogenous metabolites. We have investigated the effects of cytokines and survival/growth factors, implicated in various placental pathologies, on ABC transporter expression and function in primary placental trophoblast cells. Treatment of primary term trophoblasts in vitro with tumor necrosis factor-alpha (TNF-alpha) or interleukin (IL)-1beta decreased mRNA and protein expression of apical transporters ABCB1/multidrug resistance gene product 1 (MDR1) and ABCG2/breast cancer resistance protein (BCRP) protein by 40 to 50% (P < 0.05). In contrast, IL-6 increased mRNA and protein expression of the basolateral transporter ABCB4/MDR3 (P < 0.05), whereas ABCC1/MRP1 expression was unaltered. Pretreatment of trophoblasts with TNF-alpha over 48 h resulted in significantly decreased BCRP efflux activity (increased mitoxantrone accumulation) with minimal changes in MDR1/3 activity. Epidermal growth factor (EGF) and insulin-like growth factor II, on the other hand, significantly increased BCRP expression at the mRNA and protein level (P < 0.05); EGF treatment also increased BCRP functional activity. Estradiol stimulated BCRP, MDR1, and MDR3 mRNA and protein expression by 40 to 60% and increased MDR1/3 functional activity (P < 0.05). Progesterone had modest positive effects on MRP1 mRNA and MDR1 protein expression (P < 0.05). In conclusion, this study shows that proinflammatory cytokines, sex steroids, and growth factors exert independent effects on expression of apical and basolateral placental ABC transporters in primary trophoblast. Such changes could alter placental drug disposition, increase fetal susceptibility to toxic xenobiotics, and impact on placental viability and function.