Estrogen-Like Response to p-Nonylphenol in Human First Trimester Placenta and BeWo Choriocarcinoma Cells

Lysosome dynamics during human endometrial stromal cells decidualization: effect of para-nonylphenol

During the process of decidualization, the stromal cells of the endometrium change dynamically to create a favorable environment for embryo implantation. Lysosome activity has often been associated with physiological changes in the endometrium during the preimplantation period and early pregnancy. In this study, the effect of para-nonylphenol (p-NP), an endocrine disruptor, on human immortalized endometrial stromal cells (tHESCs) was investigated. After exposure to p-NP (1 nM and 1 pM), the cells were examined for the decidualization markers connexin-43, insulin like growth factor binding protein 1 (IGFBP1), and prolactin. In addition, the effect of p-NP on lysosome biogenesis and exocytosis was investigated by examining the expression and localization of the transcription factor EB (TFEB) and that of the lysosomal-associated membrane protein 1 (LAMP-1). Finally, we evaluated the effect of p-NP on extracellular matrix (ECM) remodeling using a fibronectin assay. Our results showed that p-NP reduced the expression of prolactin protein, increased the nuclear localization of TFEB, and induced the increase and translocation of the lysosomal protein LAMP-1 to the membrane of tHESCs. The data indicate an impairment of decidualization and suggest an increase in lysosomal biogenesis and exocytosis, which is supported by the higher release of active cathepsin D by tHESCs. Given the importance of cathepsins in the processing and degradation of the ECM during trophoblast invasiveness and migration into the decidua, our results appear to be clear evidence of the negative effects of p-NP on endometrial processes that are fundamental to reproductive success and the establishment of pregnancy.NEW & NOTEWORTHY Endocrine disruptors, such as para-nonylphenol, affect the decidualization of human endometrial stromal cells with an impact on decidualization itself, lysosome biogenesis and exocytosis, and extracellular matrix remodeling. All these alterations may negatively impact embryo implantation with the success of reproduction and the establishment of pregnancy.

Levels, distribution, sources and human exposure pathways of alkylphenol and alkylphenol ethoxylates in indoor dust in Turkiye

Environmental phenolic chemicals, due to their widespread occurrence and potent estrogenic properties, pose a risk to human exposure. The phenolic organic contaminants alkylphenols (APs) and alkylphenol polyethoxylates (APEs) are used in various household applications, and they may enter to the environment during production and use, potentially appearing in indoor dust. However, little is known about the levels of environmental phenolics in indoor environments. In this study, five of these compounds namely octylphenol (OP), 4-Octylphenol Monoethoxylate (4-OPME), 4-tert-octylphenol (4-t-OP), 4-n-nonylphenol (4-n-NP) and nonylphenol diethoxylate (di-NPE) were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in household dust samples (n = 148) collected from Ankara, the capital of Turkiye. OP and 4-OPME was not present in any of the analyzed samples. The median concentrations of the 148 settling dust samples were 35, 520, and 1910 ng g-1 dust for 4-t-OP, 4-n-NP, and di-NPE, respectively. An assessment of the human (children and adults) exposure pathway to APs and APEs, which are recognized as endocrine-disrupting chemicals found in residential dust, revealed that it was approximately 3 times higher for children than for adults at both moderate and heavy exposure levels. The association between chemical exposure, house characteristics, and family lifestyle was investigated using a multivariate logistic regression model. According to the results of this model, while the high concentrations measured for 4-t-OP were not found to be associated with any of the household parameters, high levels of 4-n-NP and di-NPE were associated with the frequency of house cleaning, repairs made during the previous year, residential type, the number of occupants, flooring materials, and the purchase of new household items within the past year. This study provides a basis for prioritizing toxicology and exposure studies for EDCs and mixtures and may offer new tools for exposure assessment in health studies.

Paternal obesity induces epigenetic aberrations and gene expression changes in placenta and fetus

Paternal epigenome regulates placental and fetal growth. However, the effect of paternal obesity on placenta and its subsequent effect on the fetus via sperm remains unknown. We previously discovered abnormal methylation of imprinted genes involved in placental and fetal development in the spermatozoa of obese rats. In the present study, elaborate epigenetic characterization of sperm, placenta, and fetus was performed. For 16 weeks, male rats were fed either control or a high-fat diet. Following mating studies, sperm, placenta, and fetal tissue were collected. Significant changes were observed in placental weights, morphology, and cell populations. Methylation status of imprinted genes-Igf2, Peg3, Cdkn1c, and Gnas in spermatozoa, correlated with their expression in the placenta and fetus. Placental DNA methylating enzymes and 5-methylCytosine levels increased. Furthermore, in spermatozoa, DNA methylation of a few genes involved in pathways associated with placental endocrine function-gonadotropin-releasing hormone, prolactin, estrogen, and vascular endothelial growth factor, correlated with their expression in placenta and fetus. Changes in histone-modifying enzymes were also observed in the placenta. Histone marks H3K4me3, H3K9me3, and H4ac were downregulated, while H3K27me3 and H3ac were upregulated in placentas derived from obese male rats. This study shows that obesity-related changes in sperm methylome translate into abnormal expression in the F1-placenta fathered by the obese male, presumably affecting placental and fetal development.

Effects of phenolic compounds on 3β-hydroxysteroid dehydrogenase activity in human and rat placenta: Screening, mode of action, and docking analysis

Human 3β-hydroxysteroid dehydrogenase type I (HSD3B1) and rat type IV (HSD3B4) in placentas catalyze the conversion of pregnenolone to progesterone, which plays a key role in maintaining pregnancy. Many phenolic compounds potentially inhibit HSD3B in placentas as endocrine disruptors. In this study, the effects of 16 phenolic compounds on the activity of human HSD3B1 and rat HSD3B4 were determined and the structure-activity relationship was compared. HSD3B1 in human placental microsomes and HSD3B4 in rat placental microsomes were used to measure their activities and pregnenolone and NAD⁺ were used as substrates. Of the 16 phenolic compounds, 4-nonylphenol, pentabromophenol, and 2-bromophenol resulted in residual human HSD3B1 activity lower than 50 % and 4-nonylphenol and pentabromophenol resulted in residual rat HSD3B4 activity lower than 50 %. 4-Nonylphenol, pentabromophenol, and 2-bromophenol were mixed inhibitors of human HSD3B1, with Ki values of 2.31, 3.58 and 4.86 µM, respectively, while 4-nonylphenol and pentabromophenol were noncompetitive inhibitors of rat HSD3B4 with Ki values of 20.86 and 141.8 µM. Molecular docking showed that 4-nonylphenol, pentabromophenol, and 2-bromophenol docked to the active sites of human HSD3B1 and rat HSD3B4, and the shift of residue S125 in human HSD3B1 to T125 in rat HSD3B4 could explain the species-dependent difference in their inhibitory potency and mode of action. This study demonstrates that 4-nonylphenol, pentabromophenol, and 2-bromophenol are mixed inhibitors of human placental HSD3B1, while 4-nonylphenol and pentabromophenol are noncompetitive inhibitors of rat HSD3B4, possibly blocking the placental steroidogenesis.

Cadmium inhibits forskolin-induced differentiation of human placental BeWo cells

Cadmium (Cd) is an environmental pollutant. Blood Cd levels in pregnant women have been associated with premature births, infant birth size, placenta previa, and placenta accreta. There have been concerns on the reproductive developmental toxicity of Cd. The choriocarcinoma cell line BeWo, a cellular in vitro model for studying syncytial fusion, has been widely used to study the reproductive and developmental toxic effects of pollutants. Here, we examine the inhibitory effect of Cd against forskolin (FSK)-induced BeWo differentiation. Results showed that Cd exposure inhibited the FSK-induced expression of syncytiotrophoblast-related genes LGALS13, ERVFRD1, SDC1, and CGB3. Inhibition of LGALS13 expression was due to the inhibition of the PKA pathway, whereas the inhibition of the other three genes could be due to the inhibition of the other pathways. These findings could help clarify the reproductive and developmental toxicity of Cd.

Prenatal exercise in fetal development: a placental perspective

Maternal obesity (MO) and gestational diabetes mellitus (GDM) are common in Western societies, which impair fetal development and predispose offspring to metabolic dysfunction. Placenta is the organ linking the mother to her fetus, and MO suppresses the development of vascular system and expression of nutrient transporters in placenta, thereby affecting fetal development. For maintaining its proper physiological function, placenta is energy demanding, which is met through extensive oxidative phosphorylation. However, the oxidative capacity of placenta is suppressed due to MO and GDM. Recently, several studies showed that physical activity during pregnancy enhances oxidative metabolism and improves placental function, which might be partially mediated by exerkines, referring to cytokines elicited by exercise. In addition, as an endocrine organ, placenta secretes cytokines, termed placentokines, including apelin, superoxide dismutase 3, irisin, and adiponectin, which mediate fetal development and maternal metabolism. Possible molecular mechanisms linking maternal exercise and placentokines to placental and fetal development are further discussed. As an emerging field, up to now, available studies are limited, mostly conducted in rodents. Given the epidemics of obesity and metabolic disorders, as well as the prevalence of maternal sedentary lifestyle, the effects of exercise of pregnant women on placental function and placentokine secretion, as well as their impacts on fetal development, need to be further examined.

A prominent environmental endocrine disruptor, 4-nonylphenol, promotes endometriosis development via plasmacytoid dendritic cells

Endometriosis is an estrogen-dependent chronic inflammatory disease and is associated etiologically with environmental endocrine disruptor (EED) exposure. 4-nonylphenol (NP), a widely found EED, has weak estrogenic activity and modulates plasmacytoid dendritic cell (pDC) function in vitro and in vivo. We aimed to elucidate the immunomodulatory effect of NP on the development of endometriosis, particularly focusing on pDCs. This study established a surgically induced endometriosis murine model (C57BL/6) under conditions of NP treatment that are relevant to the level and route of human exposure. Multi-parametric flow cytometry was used for analysis of infiltrated immune cell subsets in lesions. The results showed that NP exposure significantly promoted endometriotic lesion growth, survival and angiogenesis development of lesions as well as pDC accumulation in the lesions in mice. Adoptive transfer of NP-conditioned pDCs into mice significantly enhanced lesion development and local pDC infiltration, whereas NP-conditioned conventional dendritic cells did not affect lesion growth. In vitro functional analysis showed that NP-conditioned pDCs in lesions expressed high levels of CD36, a scavenger receptor and NP-conditioned splenic pDCs secreted an enhanced level of IL-10 in response to apoptotic cell recognition in a CD36-dependent manner. Furthermore, we observed that local treatment with blocking antibodies against IL-10 and CD36 on the day of surgery significantly inhibited lesion development. NP exposure also altered the estrous cycle in mice. The results suggest that chronic and low-dose exposure to NP enhances endometriotic lesion growth by altering pDC homeostasis and function. This study has important implications for understanding the environment-innate immunity interaction in human endometriosis.

The Cannabinoid Delta-9-tetrahydrocannabinol Disrupts Estrogen Signaling in Human Placenta

Cannabis consumption is increasing worldwide either for recreational or medical purposes. Its use during gestation is associated with negative pregnancy outcomes such as, intrauterine growth restriction, preterm birth, low birth weight, and increased risk of miscarriage, though the underlying molecular mechanisms are unknown. Cannabis sativa main psychoactive compound, Δ9-tetrahydrocannabinol (THC) is highly lipophilic, and as such, readily crosses the placenta. Consequently, THC may alter normal placental development and function. Here, we hypothesize alterations of placental steroidogenesis caused by THC exposure. The impact on placental estrogenic signaling was examined by studying THC effects upon the enzyme involved in estrogens production, aromatase and on estrogen receptor α (ERα), using placental explants, and the cytotrophoblast cell model BeWo. Aromatase expression was upregulated by THC, being this effect potentiated by estradiol. THC also increased ERα expression. Actions on aromatase were ERα-mediated, as were abolished by the selective ER downregulator ICI-182780 and dependent on the cannabinoid receptor CB1 activation. Furthermore, the presence of the aromatase inhibitor Exemestane did not affect THC-induced increase in ERα expression. However, THC effects on ERα levels were reversed by the antagonists of CB1 and CB2 receptors AM281 and AM630, respectively. Thus, we demonstrate major alterations in estrogen signaling caused by THC, providing new insight on how cannabis consumption leads to negative pregnancy outcomes, likely through placental endocrine alterations. Data presented in this study, together with our recently reported evidence on THC disruption of placental endocannabinoid homeostasis, represent a step forward into a deeper comprehension of the puzzling actions of THC.

Environmental Exposure during Pregnancy: Influence on Prenatal Development and Early Life: A Comprehensive Review

Preconception and prenatal exposure to environmental contaminants may affect future health. Pregnancy and early life are critical sensitive windows of susceptibility. The aim of this review was to summarize current evidence on the toxic effects of environment exposure during pregnancy, the neonatal period, and childhood. Alcohol use is related to foetal alcohol spectrum disorders, foetal alcohol syndrome being its most extreme form. Smoking is associated with placental abnormalities, preterm birth, stillbirth, or impaired growth and development, as well as with intellectual impairment, obesity, and cardiovascular diseases later in life. Negative birth outcomes have been linked to the use of drugs of abuse. Pregnant and lactating women are exposed to endocrine-disrupting chemicals and heavy metals present in foodstuffs, which may alter hormones in the body. Prenatal exposure to these compounds has been associated with pre-eclampsia and intrauterine growth restriction, preterm birth, and thyroid function. Metals can accumulate in the placenta, causing foetal growth restriction. Evidence on the effects of air pollutants on pregnancy is constantly growing, for example, preterm birth, foetal growth restriction, increased uterine vascular resistance, impaired placental vascularization, increased gestational diabetes, and reduced telomere length. The advantages of breastfeeding outweigh any risks from contaminants. However, it is important to assess health outcomes of toxic exposures via breastfeeding. Initial studies suggest an association between pre-eclampsia and environmental noise, particularly with early-onset pre-eclampsia. There is rising evidence of the negative effects of environmental contaminants following exposure during pregnancy and breastfeeding, which should be considered a major public health issue.

Steroid hormones and first trimester vascular remodeling

Successful implantation and placentation require neoangiogenesis and the remodeling of the uterine spiral arteries. Progesterone and estradiol control various of the placental functions, but their role in vascular remodeling remains controversial. Therefore, this chapter aims to summarize the current knowledge regarding the role of steroid hormones in the uteroplacental vascular remodeling during the first trimester of gestation.

A toolkit for the application of placental-fetal molecular biomarkers in epidemiologic studies of the fetal origins of chronic disease

Purpose of review

In this review, we provide essential background knowledge and an analytical framework for the application of placental-fetal molecular biomarkers in fetal origins chronic disease epidemiology. The widely available and highly quantitative placental hormone human chorionic gonadotropin (hCG) is used as an example. hCG is currently used for diagnosing fetal genetic disorders; yet it can and should be expanded to understanding the fetal origins of chronic diseases. We provide justification and methods to do this.

Recent findings

Ten papers published in the last 5 years were identified with supportive findings relevant to the application of biomarkers of hCG in epidemiologic studies on the developmental origins of health and disease (DOHaD).

Summary

There is increasing and consistent evidence that placental-fetal biomarkers may be highly informative in observational studies, as exemplified by hCG, with the correct approaches for measurement and data analysis.

Developing novel in vitro methods for the risk assessment of developmental and placental toxicants in the environment

During pregnancy, the placenta is critical for the regulation of maternal homeostasis and fetal growth and development. Exposures to environmental chemicals during pregnancy can be detrimental to the health of the placenta and therefore adversely impact maternal and fetal health. Though research on placental-derived developmental toxicity is expanding, testing is limited by the resources required for traditional test methods based on whole animal experimentation. Alternative strategies utilizing in vitro methods are well suited to contribute to more efficient screening of chemical toxicity and identification of biological mechanisms underlying toxicity outcomes. This review aims to summarize methods that can be used to evaluate toxicity resulting from exposures during the prenatal period, with a focus on newer in vitro methods centered on placental toxicity. The following key aspects are reviewed: (i) traditional test methods based on animal developmental toxicity testing, (ii) in vitro methods using monocultures and explant models, as well as more recently developed methods, including co-cultures, placenta-on-a-chip, and 3-dimensional (3D) cell models, (iii) endpoints that are commonly measured using in vitro designs, and (iv) the translation of in vitro methods into chemical evaluations and risk assessment applications. We conclude that findings from in vitro placental models can contribute to the screening of potentially hazardous chemicals, elucidation of chemical mechanism of action, incorporation into adverse outcome pathways, estimation of doses eliciting toxicity, derivation of extrapolation factors, and characterization of overall risk of adverse outcomes, representing key components of chemical regulation in the 21^st century.

Homosalate aggravates the invasion of human trophoblast cells as well as regulates intracellular signaling pathways including PI3K/AKT and MAPK pathways

Homosalate is an organic ultraviolet filter used in most sunscreens but has been reported to be toxic to marine organisms. The estrogenic activity of homosalate has also been reported, but its endocrine-disrupting effect remains unclear. Although homosalate has been detected in human placental tissues, its effect on the survival of human trophoblast cells needs to be investigated. Therefore, in this study, we evaluated if HTR8/SVneo, a human trophoblast cell line, treated with homosalate showed decreasing proliferative activity in a dose-dependent manner. Homosalate promoted the death of HTR8/SVneo cells with elevated lipid peroxidation and intracellular Ca²⁺ concentration. It also induced endoplasmic reticulum stress and mitochondrial morphological disturbances associated with the differentiation of human trophoblast cells. However, when the intracellular Ca²⁺ or reactive oxygen species were removed using BAPTA-AM or N-acetyl-L-cysteine (NAC), the cell proliferation suppressed by homosalate was restored. Homosalate also significantly inhibited the invasion of HTR8/SVneo cells. Furthermore, it modulated phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways, which were involved in the cross-talk between both signaling pathways in HTR8/SVneo cells. Thus, homosalate adversely affects the survival, proliferation, and invasiveness of human trophoblast cells and therefore pregnant women should practice caution while using personal care products containing homosalate.

Endocrine-disrupting metabolites of alkylphenol ethoxylates - A critical review of analytical methods, environmental occurrences, toxicity, and regulation

Despite the fact that metabolites of alkylphenol ethoxylates (APEO) are classified as hazardous substances, they continue to be released into the environment from a variety of sources and are not usually monitored. Their wide use has led to an increase in the possible exposure pathways for humans, which is cause for alarm. Moreover, there is a lack of knowledge about the behaviour of these metabolites with respect to the environment and toxicity, and their biological effects on human health. The aim of this work is to give an overview of the APEO metabolites and their analysis, occurrences and toxicity in various environmental and human samples. APEO metabolites have adverse effects on humans, wildlife, and the environment through their release into the environment. Currently, there are some reviews available on the behaviour of alkylphenols in soil, sediments, groundwater, surface water and food. However, none of these articles consider their toxicity in humans and especially their effect on the nervous and immune system. This work summarises the environmental occurrences of metabolites of APEOs in matrices, e.g. water, food and biological matrices, their effect on the immune and nervous systems, and isomer-specific issues. With that emphasis we are able to cover most common occurrences of human exposure, whether direct or indirect.

hCG and Its Disruption by Environmental Contaminants during Human Pregnancy

Human chorionic gonadotropin (hCG) is a hormone of considerable importance in the establishment, promotion and maintenance of human pregnancy. It has been clearly demonstrated that hCG exerts multiple endocrine, paracrine and autocrine actions on a variety of gestational and non-gestational cells and tissues. These actions are directed to promote trophoblast invasiveness and differentiation, placental growth, angiogenesis in uterine vasculature, hormone production, modulation of the immune system at the maternal-fetal interface, inhibition of myometrial contractility as well as fetal growth and differentiation. In recent years, considerable interest has been raised towards the biological effects of environmental contaminants, particularly endocrine disrupting chemicals (EDCs). Emerging evidence suggests that prenatal exposure to selected EDCs can have a deleterious impact on the fetus and long-lasting consequences also in adult life. The results of the in vitro effects of commonly found EDCs, particularly Bisphenol A (BPA) and para-Nonylphenol (p-NP), indicate that these substances can alter hCG production and through this action could exert their fetal damage, suggesting that hCG could represent and become a potentially useful clinical biomarker of an inappropriate prenatal exposure to these substances.

The regulation of oxytocin and oxytocin receptor in human placenta according to gestational age

Oxytocin (OXT) is a peptide hormone that plays a central role in the regulation of parturition and lactation. OXT signaling is mediated by OXT receptor (OXTR), which shows species- and tissue-specific expressions and gene regulation. In the present study, we examined the synthesis of OXT and OXTR in human placenta tissue according to gestational age. A total of 48 placentas were divided into early preterm, late preterm and term groups depending on gestational age, and expression of OXT and OXTR was evaluated. First, OXT and OXTR mRNA and protein were detected in normal placenta tissue via Q-PCR, Dot-blot and Western blot assay. Both OXT and OXTR levels in normal placenta increased gradually in the late stage of pregnancy, suggesting that local OXT may play a critical role in the function of the placenta. To determine the regulatory mechanism of OXT, placental BeWo cells were administrated estrogen (E2) or progesterone (P₄), and expression of OXT and OXTR was tested. The mRNA and protein levels of OXT and OXTR were upregulated by E2 but blocked by co-treatment with P₄ In order to confirm the estrogen receptor (ESR)-mediated signaling, we administrated ESR antagonists together with E2 to BeWo cells. As a result, both OXT and OXTR were significantly altered by ESR1 antagonist (MPP) while moderately regulated by ESR2 antagonist (PHTPP). These results suggest that OXT and OXTR are controlled mainly by E2 in the placenta via ESR1 and thus may play physiological functions in the human placenta during the late stage of pregnancy.

Polarized macrophages treated with nonylphenol differently regulate lipopolysaccharide-induced sepsis

Nonylphenol (NP) as well-known "endocrine disrupter" influences sexual and reproductive development. Here, we investigated the effect of NP on M1-/M2-type macrophages and their role in lipopolysaccharide (LPS)-induced sepsis. Polarized macrophages of M1- and M2-types were obtained by the treatment with LPS and interleukin-4 (IL-4) to bone marrow-derived macrophages (BMDM), respectively. Coincubation of M1-macrophages with NP decreased COX-2, iNOS, IL-6, and TNF-α expression but no changes were detected in the production of nitric oxide (NO). Survival probability of LPS-induced sepsis mice was enhanced by the injection of NP-treated BMDM as compared to the injection of NP-untreated control BMDM. In the meanwhile, the expression of arginase 1(Arg1), a marker for M2-polarized macrophages was increased by the stimulation with LPS in BMDM. Arg1 expression was also enhanced by the treatment with IL-4 in BMDM, which was reduced by the coincubation with NP. Survival probability of LPS-induced sepsis mice was decreased by the injection of BMDM treated with IL-4 and NP as compared to the injection of IL-4-treated BMDM. It suggests that NP might inhibit macrophage function and the polarization to M2-macrophages. Taken together, data demonstrate that NP could differently affect immune responses of polarized macrophages resulted in the modulation of LPS-induced sepsis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 2081-2089, 2016.

Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells

Nonylphenol and short-chain nonylphenol ethoxylates such as NP₂ EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP₂ EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389-1398, 2016.

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.

Occurrence and Maternal Transfer of Chlorinated Bisphenol A and Nonylphenol in Pregnant Women and Their Matching Embryos

Prenatal exposure has recently raised concerns over the health risks of endocrine disruptors; however, little is known about their extent and the mechanisms of maternal transfer in the embryo stage. In this study, bisphenol A (BPA), nonylphenol (NP), and their six chlorinated derivatives were quantified in decidua samples from 25 pregnant women and their matching embryos, which were collected as chorionic villi samples. Monochloro-BPA (MCBPA), dichloro-BPA (DCBPA), monochloro-NP (MCNP), and dichloro-NP (DCNP) were detected in over 70% of the decidua or chorionic villi samples, while BPA, NP, trichloro-BPA (TCBPA), and tetrachloro-BPA (TeCBPA) were detected in less than half. The geometric mean (GM) concentrations of MCBPA, DCBPA, NP, MCNP, and DCNP in chorionic villi samples were 0.13, 0.17, 5.33, 4.52, and 2.44 ng/g dw, respectively, higher than those in maternal decidua samples, which were 0.10, 0.12, 3.27, 1.85, and 0.74 ng/g dw, respectively, while the GM concentration of BPA was lower in chorionic villi samples (0.09 ng/g dw) than in maternal decidua (0.10 ng/g dw). The ratios of the average lipid-normalized concentrations of chemicals in chorionic villi to those in maternal decidua (EMR) were calculated to be 1.53 for MCNP and 2.38 for DCNP, while those of BPA, MCBPA, DCBPA, and NP were lower than 1 (0.39-0.97). Such obvious difference in maternal transfer is probably due to their different affinities to plasma proteins, as exemplified by the correlation between EMR and the binding affinities to T4 transport proteins (TTR). This is the first report on the occurrence and maternal transfer of chlorinated derivatives of BPA and NP in human embryos and decidua.

Prenatal nonylphenol exposure, oxidative and nitrative stress, and birth outcomes: A cohort study in Taiwan

Data concerning the effects of prenatal exposures to nonylphenol (NP) and oxidative stress on neonatal birth outcomes from human studies are limited. A total of 146 pregnant women were studied (1) to investigate the association between prenatal NP exposure and maternal oxidative/nitrative stress biomarkers of DNA damage (8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO2Gua)) and lipid peroxidation (8-iso-prostaglandin F2α (8-isoPF2α), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)) and (2) to explore the associations among oxidative stress biomarkers, NP exposure, and neonatal birth outcomes, including gestational age, birth weight, length, Ponderal index, and head and chest circumferences. NP significantly increased the 8-OHdG and 8-NO2Gua levels. All infants born to mothers with urinary 8-OHdG levels above the median exhibited a significantly shorter gestational duration (Badjusted = -4.72 days; 95% CI: -8.08 to -1.36 days). No clear association was found between NP levels and birth outcomes. Prenatal 8-OHdG levels might be a novel biomarker for monitoring fetal health related to NP exposure.

The endocrine function of human placenta: an overview

During pregnancy, several tightly coordinated and regulated processes take place to enable proper fetal development and gestational success. The formation and development of the placenta is one of these critical pregnancy events. This organ plays essential roles during gestation, including fetal nourishment, support and protection, gas exchange and production of several hormones and other mediators. Placental hormones are mainly secreted by the syncytiotrophoblast, in a highly and tightly regulated way. These hormones are important for pregnancy establishment and maintenance, exerting autocrine and paracrine effects that regulate decidualization, placental development, angiogenesis, endometrial receptivity, embryo implantation, immunotolerance and fetal development. In addition, because they are released into maternal circulation, the profile of their blood levels throughout pregnancy has been the target of intense research towards finding potential robust and reliable biomarkers to predict and diagnose pregnancy-associated complications. In fact, altered levels of these hormones have been associated with some pathologies, such as chromosomal anomalies or pre-eclampsia. This review proposes to revise and update the main pregnancy-related hormones, addressing their major characteristics, molecular targets, function throughout pregnancy, regulators of their expression and their potential clinical interest.

Biological Tools to Study the Effects of Environmental Contaminants at the Feto-Maternal Interface

The identification of reproductive toxicants is a major scientific challenge for human health. Prenatal life is the most vulnerable and important time span of human development. For obvious ethical reasons, in vivo models cannot be used in human pregnancy, and animal models do not perfectly reflect human physiology. This review describes the in vitro test models representative of the human feto-maternal interface and the effects of environmental chemicals with estrogen-like activity, mainly bisphenol A and para-nonylphenol, with a particular emphasis on the effects at low, nontoxic doses similar to concentrations commonly detected in the population.

Low concentrations of Bisphenol A and para-Nonylphenol affect extravillous pathway of human trophoblast cells

Bisphenol A (BPA) and para-Nonylphenol (p-NP) are chemicals of industrial origin which may influence human reproductive health. The effects of these substances in the prenatal life is an important topic that is receiving greater attention in the developed countries. In this study, human trophoblast cells HTR-8/SVneo were exposed to BPA and p-NP (1 × 10(-15), 1 × 10(-13), 1 × 10(-11), 1 × 10(-9) and 1 × 10(-7) M) and incubated for 24, 48 and/or 72 h then, examined for the main physiological processes which characterize the extravillous trophoblast. Cell proliferation showed no changes while the processes of cell migration and invasion were both reduced by BPA and p-NP. For each chemical, the activity was higher at lower concentrations with a maximum activity between 1 × 10(-13) and 1 × 10(-11) M (p < 0.05 for 1 × 10(-9) and p < 0.001 for 1 × 10(-11) M). Co-culture studies with human umbilical cord endothelial cells (HUVEC) revealed that trophoblast/endothelial interaction was significantly reduced by p-NP at 1 × 10(-11) M. Moreover, both chemicals were inducing differentiation of HTR-8/SVneo toward polyploidy by the process of endoreduplication. The estrogen-receptor antagonist ICI significantly reduced p-NP action, while it had no effect on BPA treated cells. In conclusion, p-NP and BPA act on trophoblast cells altering key physiological processes in placenta development. The exact mechanism of action of the chemicals in human trophoblast still needs to be clarified.

Estrogen enhances secretion of apolipoprotein B-100 containing lipoproteins by BeWo cells

Although the early human embryo is capable of covering its cholesterol demand by endogenous synthesis, during later stages of development the fetus may become dependent on transplacental cholesterol transport. On one hand, this conclusion is based on the severe developmental abnormalities of embryos with mutations in the gene specifying the enzyme catalyzing the last step of cholesterol synthesis, 7-dehydrocholesterol reductase, causing Smith-Lemli-Opitz Syndrome. On the other hand, increased total maternal plasma cholesterol levels may reflect the requirement by the growing fetus and/or the placenta for cholesterol. Various molecules and complexes must cross the placental barrier consisting of trophoblasts and fetal endothelial cells to reach the fetal circulation. The de novo synthesis of apolipoprotein B (apoB)-containing lipoproteins coupled to secretion from trophoblasts towards the fetal side is one efficient pathway for cholesterol supply. ApoB and the microsomal triglyceride transfer protein (MTP) are essential components for the assembly of apoB-containing lipoproteins. The aim of this study was to evaluate functional properties of the human placental cell line BeWo as an in vitro model for placental synthesis of apoB-containing lipoproteins by focusing on components required for lipoprotein assembly and secretion. We demonstrate mRNA and protein production of apoB-100, MTP, and protein disulfide isomerase (PDI) in BeWo cells. In addition, metabolic radiolabeling and apoB-immunoprecipitation of cell extracts and media revealed that synthesis and secretion of apoB-containing lipoproteins are enhanced by estrogen. The expression of apoB-100, MTP, and PDI, and the estrogen-stimulated lipoprotein secretion by BeWo cells suggest that these cells are a useful system to study aspects of lipoprotein metabolism at the placental barrier.

Bisphenol A alters β-hCG and MIF release by human placenta: an in vitro study to understand the role of endometrial cells

A proper fetomaternal immune-endocrine cross-talk in pregnancy is fundamental for reproductive success. This might be unbalanced by exposure to environmental chemicals, such as bisphenol A (BPA). As fetoplacental contamination with BPA originates from the maternal compartment, this study investigated the role of the endometrium in BPA effects on the placenta. To this end, in vitro decidualized stromal cells were exposed to BPA 1 nM, and their conditioned medium (diluted 1 : 2) was used on chorionic villous explants from human placenta. Parallel cultures of placental explants were directly exposed to 0.5 nM BPA while, control cultures were exposed to the vehicle (EtOH 0.1%). After 24–48 h, culture medium from BPA-treated and control cultures was assayed for concentration of hormone human Chorionic Gonadotropin (β-hCG) and cytokine Macrophage Migration Inhibitory Factor (MIF). The results showed that direct exposure to BPA stimulated the release of both MIF and β-hCG. These effects were abolished/diminished in placental cultures exposed to endometrial cell-conditioned medium. GM-MS analysis revealed that endometrial cells retain BPA, thus reducing the availability of this chemical for the placenta. The data obtained highlight the importance of in vitro models including the maternal component in reproducing the effects of environmental chemicals on human fetus/placenta.

The placenta in toxicology. Part IV: Battery of toxicological test systems based on human placenta

This review summarizes the potential and also some limitations of using human placentas, or placental cells and structures for toxicology testing. The placenta contains a wide spectrum of cell types and tissues, such as trophoblast cells, immune cells, fibroblasts, stem cells, endothelial cells, vessels, glands, membranes, and many others. It may be expected that in many cases the relevance of results obtained from human placenta will be higher than those from animal models due to species specificity of metabolism and placental structure. For practical and economical reasons, we propose to apply a battery of sequential experiments for analysis of potential toxicants. This should start with using cell lines, followed by testing placenta tissue explants and isolated placenta cells, and finally by application of single and dual side ex vivo placenta perfusion. With each of these steps, the relative workload increases while the number of feasible repeats decreases. Simultaneously, the predictive power enhances by increasing similarity with in vivo human conditions. Toxic effects may be detected by performing proliferation, vitality and cell death assays, analysis of protein and hormone expression, immunohistochemistry or testing functionality of signaling pathways, gene expression, transport mechanisms, and so on. When toxic effects appear at any step, the subsequent assays may be cancelled. Such a system may be useful to reduce costs and increase specificity in testing questionable toxicants. Nonetheless, it requires further standardization and end point definitions for better comparability of results from different toxicants and to estimate the respective in vivo translatability and predictive value.

Toxicity assessment on trophoblast cells for some environment polluting chemicals and 17β-estradiol

The identification of reproductive toxicants is a major scientific challenge for human health. We investigated the effects of a selected group of environmental polluting chemicals mostly provided with estrogenic activity on the human trophoblast cell lines BeWo and HTR-8/SVneo. Cells were exposed for 24h to various concentrations (from 0.1 pM to 1 mM) of atrazine (ATR), diethylstilbestrol (DES), para-nonylphenol (p-NP), resveratrol (RES) and 17 β-estradiol (E2) and assayed for cell viability and human beta-Chorionic Gonadotropin (β-hCG) secretion. Decrease of cell viability as respect to control, vehicle-treated, cultures was obtained for all chemicals in the concentration range of 1 μM-1 mM in both cell types. A parallel decrease of β-hCG secretion was observed in BeWo cells, at 1 μM-1 mM concentrations, with the only exception of ATR which caused an increase at concentrations up to 1mM. β-hCG release was also unexpectedly inhibited by ATR, DES, p-NP and RES at non-toxic (pM-nM) concentrations. These findings raise concern about the negative, potential effects of various environmental polluting chemicals on pregnancy success and fetal health.

The effect of triclosan on hormone secretion and viability of human choriocarcinoma JEG-3 cells

Triclosan is an antimicrobial agent frequently used in pharmaceuticals and personal care products. We analyzed triclosan for its action on placental secretion of progesterone, estradiol and human chorionic gonadotropin in vitro in the JEG-3 cells. We also investigated its action on cell viability, proliferation and apoptosis. The JEG-3 cells were cultured with increasing doses of triclosan (1×10(-9)-1×10(-4) M) for 24, 48 and 72 h. Triclosan was found to increase estradiol and progesterone secretion after short- and long-term exposure. The stimulatory effect was observed up to 10 μM after short- and long-term exposure to triclosan. In addition, triclosan caused an adverse effect on β-hCG secretion. The highest doses of triclosan (50 and 100 μM) showed a strong cytotoxic effect. Anti proliferative and pro-apoptotic effects were also observed. Overall, this study demonstrates that triclosan may indirectly disrupt steroidogenesis which may, in turn, affect placental development and consequently fetal growth.

In vitro placental model optimization for nanoparticle transport studies

BACKGROUND

Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman's exposure to nanoparticles could have significant effects on the fetus developing in the womb. Therefore, the purpose of this study is to optimize an in vitro model for characterizing the transport of nanoparticles across human placental trophoblast cells.

METHODS

The growth of BeWo (clone b30) human placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell(®) insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium transport. Following the determination of nontoxic concentrations of fluorescent polystyrene nanoparticles, the cellular uptake and transport of 50 nm and 100 nm diameter particles was measured using the in vitro BeWo cell model.

RESULTS

Particle size measurements, fluorescence readings, and confocal microscopy indicated both cellular uptake of the fluorescent polystyrene nanoparticles and the transcellular transport of these particles from the apical (maternal) to the basolateral (fetal) compartment. Over the course of 24 hours, the apparent permeability across BeWo cells grown on polycarbonate membranes (3.0 μm pore size) was four times higher for the 50 nm particles compared with the 100 nm particles.

CONCLUSION

The BeWo cell line has been optimized and shown to be a valid in vitro model for studying the transplacental transport of nanoparticles. Fluorescent polystyrene nanoparticle transport was size-dependent, as smaller particles reached the basal (fetal) compartment at a higher rate.

Regulation of leptin expression by 17beta-estradiol in human placental cells involves membrane associated estrogen receptor alpha

The placenta produces a wide number of molecules that play essential roles in the establishment and maintenance of pregnancy. In this context, leptin has emerged as an important player in reproduction. The synthesis of leptin in normal trophoblastic cells is regulated by different endogenous biochemical agents, but the regulation of placental leptin expression is still poorly understood. We have previously reported that 17β-estradiol (E(2)) up-regulates placental leptin expression. To improve the understanding of estrogen receptor mechanisms in regulating leptin gene expression, in the current study we examined the effect of membrane-constrained E(2) conjugate, E-BSA, on leptin expression in human placental cells. We have found that leptin expression was induced by E-BSA both in BeWo cells and human placental explants, suggesting that E(2) also exerts its effects through membrane receptors. Moreover E-BSA rapidly activated different MAPKs and AKT pathways, and these pathways were involved in E(2) induced placental leptin expression. On the other hand we demonstrated the presence of ERα associated to the plasma membrane of BeWo cells. We showed that E(2) genomic and nongenomic actions could be mediated by ERα. Supporting this idea, the downregulation of ERα level through a specific siRNA, decreased E-BSA effects on leptin expression. Taken together, these results provide new evidence of the mechanisms whereby E(2) regulates leptin expression in placenta and support the importance of leptin in placental physiology.

Effects of nonylphenol on the production of progesterone on the rats granulosa cells

We investigated the effects of nonylphenol (NP) on release of progesterone (PG) by granulosa cells (GCs) of rats in vitro and in vivo. First, GCs were treated with different doses of NP for 2-24 h alone or with human chorionic gonadotropin (hCG). Maximal PG secretion at 8 h noted, GCs were treated for 2 h with hCG, 8-bromo-adenosine 3':5'-cyclic monophosphate (8-Br-cAMP), forskolin, A23187, nifedipine, and pregnelonone to evaluate the NP effects on PG steroidogenesis. Results indicated that all of chemicals except nifedipine stimulated the PG release compared to vehicle, but the stimulatory effects could not be enhanced by different doses of NP. Second, GCs were isolated to react with hCG, 8-Br-cAMP and PD98059 after the immature female rats gavaged with different doses of NP (ONP) for 7 days. PG released significantly when rats treated with oral NP 100 compared to 0 µg/kg/day. Third, GCs collected from the female offspring of mother rats which gavaged with NP 100 µg/kg/day for 21 days during pregnancy (MONP) reacted with different doses of chemicals. The results showed that PG release in the presence of chemicals was significantly higher in ONP and MONP groups; however, this stimulation was not noted by dose-dependent. The plasma concentration of PG was higher in ONP (100 µg/kg/day) and the offspring of MONP groups. The steroidogenic acute regulatory (StAR) protein expressed higher in all three groups by Western blotting. This study results indicated that low dose of NP stimulated PG release in rat GCs by activation of StAR protein.

Genipa americana (Rubiaceae) fruit extract affects mitogen-activated protein kinase cell pathways in human trophoblast-derived BeWo cells: implications for placental development

Genipa americana L. (Rubiaceae) is a fruit tree and a traditional medicine used to treat anemia, icterus, asthma, and liver and spleen problems. The aim of the present study was to verify the effect of G. americana fruit ethanolic extract on the mechanism for proliferation and differentiation of trophoblast-like cells. Qualitative analysis of G. americana fruit extract was performed, and BeWo cells, a well-established placental choriocarcinoma cell line that can undergo differentiation, were used to analyze cell viability and proliferation. Methods consisted of cytotoxic and proliferation measurement, detection of release of human chorionic gonadotrophins, cell fusion observation, and evaluation of cell-signaling pathways (production of cyclic adenosine monophosphate and phosphorylation of mitogen-activated protein kinases [MAPKs]). A stock solution of the extract was diluted in Ham's F-12 medium with 10% fetal bovine serum at concentrations ranging from 50 to 1000 μg/mL. Cells treated with dimethylsulfoxide, forskoline, and MAPK inhibitors (PD98059 or SB203580) were used as a control. Forskoline was used to induce the differentiation state in BeWo cells. Phytoanalysis indicated the presence of steroids only. Results showed that the G. americana fruit extract did not cause any cytotoxicity or interference in cell differentiation. However, a significant antiproliferative state related to inhibition and reactivation of ERK1/2 and p38 MAPK in BeWo cells was seen. These results suggest that steroids from G. americana may affect placental cell regulation.

Alkylphenols in adipose tissues of Italian population

Alkylphenols (APs) and AP ethoxylated compounds (APEs) were screened in human subcutaneous adipose tissue samples from Italy. The samples were collected during bariatric surgery from 16 subjects (three men and 13 women) and a total of seven alkylphenol compounds (APs) was detected. Nonylphenol (NP) was the compound found at the highest level (mean 122 ng g⁻¹ fresh weight; range 10-266 ng g⁻¹ fw). Several nonylphenol ethoxylates (NPEOs) were found in all the sample analysed though the frequency of detection decreased with the increasing number of ethoxylic groups. NP4EO was found only in four patients ranging from trace amounts to 41.3 ng g⁻¹ fw. Total nonylphenols (NPEs) ranged between 45 and 1131 ng g⁻¹ fw, whereas the concentration of total octylphenols (OPEs) was at least 10 times lower (range 6-80 ng g⁻¹ fw). Our findings show that the average concentration of NP is about two times higher than that found in women from Southern Spain and up to three times that of people from Switzerland. Similarly, OP mean level is two times that reported in Finland and Spain populations. This is the first study that reports the presence of alkylphenols in the Italian population adipose tissue and it draws a baseline for further researches in order to depict a trend in human exposure to these compounds and to investigate possible consequences for human health.

Effects and mechanisms of nonylphenol on corticosterone release in rat zona fasciculata-reticularis cells

Alkylphenol ethoxylate, consisting of ∼80% nonylphenol ethoxylate (NPEO), is a major group of nonionic surfactant. The primary degradation product of NPEO, nonylphenol (NP), interferes with reproduction, induces cell death in gonads, and leads to changes in other reproductive parameters. With such apparent stress, NP is believed to induce stress response mechanism, i.e., adrenal cortical hormone. However, the effects and action mechanisms of NP on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of NP on corticosterone release. ZFR cells were incubated with NP in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3',5'-adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxyl cholesterol (25-OH-cholesterol), pregnenolone, progesterone, or deoxycorticosterone at 37°C for 1 h. The concentrations of corticosterone or pregnenolone in the spent media were measured by radioimmunoassay. The expressions of steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleavage (P450scc) protein, and 11β-hydroxylase in the cells were measured by Western blot. The data demonstrated that (1) NP stimulated corticosterone release induced by ACTH, 8-Br-cAMP, FSK, 25-OH-cholesterol, pregnenolone, progesterone, or deoxycorticosterone; (2) NP significantly increased pregnenolone release in the control, 25-OH-cholesterol, trilostane, and 25-OH-cholesterol + trilostane groups; (3) NP-stimulated corticosterone release was estrogen receptor dependent, but mediated by nitric oxide and p38 mitogen-activated protein kinase pathway independent; and (4) NP did not affect StAR, 11β-hydroxylase, or P450scc protein expression. These results suggest that NP acts directly on rat ZFR cells to stimulate corticosterone release and that the stimulation mechanism of NP mediates through post-cAMP corticosterone manufacture enzymes, i.e., P450scc and 11β-hydroxylase.

High concentrations of commonly used drugs can inhibit the in vitro glucuronidation of bisphenol A and nonylphenol in rats

4-n-Nonylphenol and bisphenol A are endocrine disrupting chemicals that are mainly detoxified through glucuronidation. A factor that may modulate their glucuronidation rates is co-exposure to pharmaceuticals. This study aimed to identify and characterize the potential metabolic interactions between 14 drugs and these two endocrine disruptors. Nonylphenol and bisphenol A were co-incubated in freshly isolated rat hepatocytes with, drugs at a high concentration. Statistically significant metabolic inhibition of bisphenol A and nonylphenol biotransformation was observed with nine drugs (>50% inhibition by naproxen, salicylic acid, carbamazepine and mefenamic acid). Inhibition assays of UGT activity in rat liver microsomes revealed: 1) competitive inhibition by naproxen (K(i)(app) = 848.3 microM) and carbamazepine (K(i)(app) = 1023.1 microM), 2) no inhibition by salicylic acid suggesting another mechanism of inhibition. Detoxification of nonylphenol and bisphenol A was shown to be impaired by excessive concentrations of many drugs and health risk assessment should therefore address this issue.

Environmental levels of para-nonylphenol are able to affect cytokine secretion in human placenta

BACKGROUND

para-Nonylphenol (p-NP) is a metabolite of alkylphenols widely used in the chemical industry and manufacturing. It accumulates in the environment, where it acts with estrogen-like activity. We previously showed that p-NP acts on human placenta by inducing trophoblast differentiation and apoptosis.

OBJECTIVE

The aim of the present study was to investigate the effect of p-NP on cytokine secretion in human placenta.

METHODS

In vitro cultures of chorionic villous explants from human placenta in the first trimester of pregnancy were treated with p-NP (10(13), 10(11), and 10(9) M) in 0.1% ethanol as vehicle. Culture medium was collected after 24 hr and assayed by specific immunoassays for the cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-alpha).

RESULTS

p-NP modulated cytokine secretion by inducing the release of GM-CSF, IFN-gamma, IL-1beta, IL-4, and IL-10, with a maximum effect at 10(11) M. It reduced the release of TNF-alpha at 10(13) M, whereas levels of IL-2 and IL-5 remained below the detection limit. IL-6 and IL-8 levels were 1001,000 times higher than those of other cytokines, and they were not affected by p-NP. We observed significant differences from controls (ethanol alone) only for GM-CSF and IL-10.

CONCLUSION

An unbalanced cytokine network at the maternal--fetal interface may result in implantation failure, pregnancy loss, or other complications. The effects of extremely low doses of p-NP on the placental release of cytokines raise considerable concerns about maternal exposure to this endocrine disruptor during pregnancy.

17{beta}-Estradiol modulates the macrophage migration inhibitory factor secretory pathway by regulating ABCA1 expression in human first-trimester placenta

Successful pregnancy involves a series of events, most of them mediated by hormones and cytokines. Estrogens, besides being important for placental growth and embryo development, have a marked effect on the immune system exerting either pro- or anti-inflammatory properties. Numerous studies suggest that estrogens directly affect cellular function, including cytokine production. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in pregnancy, particularly during the earlier stages of placentation. Since reports on mice have shown that estrogens modulate MIF, herein we investigated the effect of estrogens on human placental MIF. By using an in vitro model of first-trimester chorionic villous explants, we found that 17beta-estradiol (E(2)) was able to modulate the release of MIF in a dose-dependent manner (10(-12) vs. 10(-9) M, P < 0.05; 10(-9) vs. 10(-5) M, P < 0.05; 10(-12) vs. 10(-5) M, P < 0.001). Unlike MIF release, no significant change in tissue MIF protein or MIF mRNA was observed. We showed evidence that E(2) concentrations (10(-9) and 10(-5) M) act on placental tissue downregulating the mRNA and protein expression of the ATP-binding cassette transporter protein A1, a membrane transporter involved in MIF secretion. These findings emphasize the mutual cooperation between hormones and cytokines and suggest that increasing estrogen levels with advancing gestation may have a major role in regulating placental MIF secretion.

Modeling placental transport: correlation of in vitro BeWo cell permeability and ex vivo human placental perfusion

The placental passage of three compounds with different physicochemical properties was recently investigated in ex vivo human placental perfusion experiments (caffeine, benzoic acid, and glyphosate) [Mose, T., Kjaerstad, M.B., Mathiesen, L., Nielsen, J.B., Edelfors, S., Knudsen, L.E., 2008. Placental passage of benzoic acid, caffeine, and glyphosate in an ex vivo human perfusion system. J. Toxicol. Environ. Health, Part A 71, 984-991]. In this work, the transport of these same three compounds, plus the reference compound antipyrine, was investigated using BeWo (b30) cell monolayers. Transport across the BeWo cells was observed in the rank order of caffeine>antipyrine>benzoic acid>glyphosate in terms of both the apparent permeability coefficient and the initial slope, defined as the linear rate of substance transferred to the fetal compartment as percent per time, a parameter used to compare the two experimental models. The results from the in vitro studies were in excellent agreement with the ex vivo results (caffeine approximately antipyrine>benzoic acid>glyphosate). However the transfer rate was much slower in the BeWo cells compared to the perfusion system. The advantages and limitations of each model are discussed in order to assist in the preparation, prediction, and performance of future studies of maternal-fetal transfer.

Expression of estrogen receptor GPR30 in the rat spinal cord and in autonomic and sensory ganglia

The G protein-coupled receptor GPR30 has recently been identified as a nonnuclear estrogen receptor. Reverse transcriptase-polymerase chain reaction revealed expression of GPR30 mRNA in varying quantities in the rat spinal cord, dorsal root ganglia, nodose ganglia, trigeminal ganglia, hippocampus, brain stem, and hypothalamus. Immunohistochemical studies that used a rabbit polyclonal antiserum against the human GPR30 C-terminus revealed a fine network of GPR30-immunoreactive (irGPR30) cell processes in the superficial layers of the spinal cord; some of which extended into deeper laminae. A population of neurons in the dorsal horn and ventral horn were irGPR30. Dorsal root, nodose, and trigeminal ganglionic neurons displayed varying intensities of irGPR30. Positively labeled neurons were detected in the major pelvic ganglion, but not in the superior cervical ganglion. A population of chromaffin cells in the adrenal medulla was irGPR30, so were cells of the zona glomerulosa. Double-labeling the adrenal medulla with GPR30 antiserum and tyrosine hydroxylase antibody or phenylethanolamine-N-methyltransferase antiserum revealed that irGPR30 is expressed in the majority of tyrosine hydroxylase-positive chromaffin cells. Last, some of the myenteric ganglion cells were irGPR30. Tissues processed with preimmune serum resulted in no staining. Voltage-sensitive dye imaging studies showed that the selective GPR30 agonist G-1 (1, 10, and 100 nM) depolarized cultured spinal neurons in a concentration-dependent manner. Collectively, our result provides the first evidence that GPR30 is expressed in neurons of the dorsal and ventral horn as well as in sensory and autonomic neurons, and activation of GPR30 by the selective agonist G-1 depolarizes cultured spinal neurons.

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.