Erratum: A Unique Co-Culture Model for Fundamental and Applied Studies of Human Fetoplacental Steroidogenesis and Interference by Environmental Chemicals (original) (raw)
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Environmental Health Perspectives, 2014
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. citation: Hudon Thibeault AA, Deroy K, Vaillancourt C, Sanderson JT. 2014. A unique co-culture model for fundamental and applied studies of human fetoplacental steroidogenesis and interference by environmental chemicals.
Toxicological Sciences, 2007
The fungicide prochloraz (PCZ) induces malformations in androgen-dependent tissues in male rats when administered during sex differentiation. The sensitivity of fetal testicular steroidogenesis to PCZ was investigated to test the hypothesis that the reported morphological effects from maternal exposure were associated with reduced testosterone synthesis. Pregnant Sprague-Dawley rats were dosed by gavage with 0, 7.8, 15.6, 31.3, 62.5, and 125 mg PCZ/kg/day (n ¼ 8) from gestational day (GD) 14 to 18. On GD 18, the effects of PCZ on fetal steroidogenesis were assessed by measuring hormone production from ex vivo fetal testes after a 3-h incubation. Lastly, PCZ levels in amniotic fluid and maternal serum were measured using liquid chromatography/mass spectroscopy and correlated to the inhibition of steroidogenesis. Fetal progesterone and 17a-hydroxyprogesterone production levels were increased significantly at every PCZ dose, whereas testosterone levels were significantly decreased only at the two high doses. These results suggest that PCZ inhibits the conversion of progesterone to testosterone through the inhibition of CYP17. To test this hypothesis, PCZ effects on CYP17 gene expression and in vitro CYP17 hydroxylase activity were evaluated. PCZ had no effect on testicular CYP17 mRNA levels as measured by quantitative real-time polymersase chain reaction. However, microsomal CYP17 hydroxylase activity was significantly inhibited by the fungicide (K i ¼ 865nM). Amniotic fluid PCZ concentrations ranged from 78 to 1512 ppb (207-4014nM) and testosterone production was reduced when PCZ reached~500 ppb, which compares favorably with the determined CYP17 hydroxylase K i (326 ppb). These results demonstrate that PCZ lowers testicular testosterone synthesis by inhibiting CYP17 activity which likely contributes to the induced malformations in androgen-dependent tissues of male offspring.
Toxicology, 2011
The H295R cell bioassay was used to evaluate the potential endocrine disrupting effects of 18 of the most commonly used pharmaceuticals in the United States. Exposures for 48 h with single pharmaceuticals and binary mixtures were conducted; the expression of five steroidogenic genes, 3βHSD2, CYP11β1, CYP11β2, CYP17 and CYP19, was quantified by Q-RT-PCR. Production of the steroid hormones estradiol (E2), testosterone (T) and progesterone (P) was also evaluated. Antibiotics were shown to modulate gene expression and hormone production. Amoxicillin up-regulated the expression of CYP11β2 and CYP19 by more than 2-fold and induced estradiol production up to almost 3-fold. Erythromycin significantly increased CYP11β2 expression and the production of P and E2 by 3.5-and 2.4-fold, respectively, while production of T was significantly decreased. The β-blocker salbutamol caused the greatest induction of CYP17, more than 13-fold, and significantly decreased E2 production. The binary mixture of cyproterone and salbutamol significantly down-regulated expression of CYP19, while a mixture of ethynylestradiol and trenbolone, increased E2 production 3.7-fold. Estradiol production was significantly affected by changes in concentrations of trenbolone, cyproterone, and ethynylestradiol. Exposures with individual pharmaceuticals showed the possible secondary effects that drugs may exert on steroid production. Results from binary mixture exposures suggested the possible type of interactions that may occur between drugs and the joint effects product of such interactions. Dose-response results indicated that although two chemicals may share a common mechanism of action the concentration effects observed may be significantly different.
Toxicology and Applied Pharmacology, 2007
The H295R cell bioassay was used to evaluate the potential endocrine disrupting effects of 18 of the most commonly used pharmaceuticals in the United States. Exposures for 48 h with single pharmaceuticals and binary mixtures were conducted; the expression of five steroidogenic genes, 3βHSD2, CYP11β1, CYP11β2, CYP17 and CYP19, was quantified by Q-RT-PCR. Production of the steroid hormones estradiol (E2), testosterone (T) and progesterone (P) was also evaluated. Antibiotics were shown to modulate gene expression and hormone production. Amoxicillin up-regulated the expression of CYP11β2 and CYP19 by more than 2-fold and induced estradiol production up to almost 3-fold. Erythromycin significantly increased CYP11β2 expression and the production of P and E2 by 3.5-and 2.4-fold, respectively, while production of T was significantly decreased. The β-blocker salbutamol caused the greatest induction of CYP17, more than 13-fold, and significantly decreased E2 production. The binary mixture of cyproterone and salbutamol significantly down-regulated expression of CYP19, while a mixture of ethynylestradiol and trenbolone, increased E2 production 3.7-fold. Estradiol production was significantly affected by changes in concentrations of trenbolone, cyproterone, and ethynylestradiol. Exposures with individual pharmaceuticals showed the possible secondary effects that drugs may exert on steroid production. Results from binary mixture exposures suggested the possible type of interactions that may occur between drugs and the joint effects product of such interactions. Dose-response results indicated that although two chemicals may share a common mechanism of action the concentration effects observed may be significantly different.
Toxicity assessment on trophoblast cells for some environment polluting chemicals and 17β-estradiol
Toxicology in Vitro, 2013
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 24 h to various concentrations (from 0.1 pM to 1 mM) of atrazine (ATR), diethylstilbestrol (DES), para-nonylphenol (p-NP), resveratrol (RES) and 17 b-estradiol (E2) and assayed for cell viability and human beta-Chorionic Gonadotropin (b-hCG) secretion.
Toxicological Sciences, 2012
Leydig cells are the primary site of androgen biosynthesis in males. Several environmental toxicants target steroidogenesis resulting in both developmental and reproductive effects including testicular dysgenesis syndrome. The aim of this study was to evaluate the effect of several structurally diverse endocrine disrupting compounds (EDCs) on steroidogenesis in a novel BLTK1 murine Leydig cell model. We demonstrate that BLTK1 cells possess a fully functional steroidogenic pathway that produces low basal levels of testosterone (T) and express all the necessary steroidogenic enzymes including Star, Cyp11a1, Cyp17a1, Hsd3b1, Hsd17b3, and Srd5a1. Recombinant human chorionic gonadotropin (rhCG) and forskolin (FSK) elicited concentration-and time-dependent induction of 3#,5#-cyclic adenosine monophosphate, progesterone (P), and T, as well as the differential expression of Star, Hsd3b6, Hsd17b3, and Srd5a1 messenger RNA levels. The evaluation of several structurally diverse male reproductive toxicants including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), atrazine, prochloraz, triclosan, monoethylhexyl phthalate (MEHP), glyphosate, and RDX in BLTK1 cells suggests different modes of action perturb steroidogenesis. For example, prochloraz and triclosan antifungals reduced rhCG induction of T, consistent with published in vivo data but did not alter basal T levels. In contrast, atrazine and MEHP elicited modest induction of basal T but antagonized rhCG-mediated induction of T levels, whereas TCDD, glyphosate, and RDX had no effect on basal or rhCG induction of T in BLTK1 cells. These results suggest that BLTK1 cells maintain rhCG-inducible steroidogenesis and are a viable in vitro Leydig cell model to evaluate the effects of EDCs on steroidogenesis. This model can also be used to elucidate the different mechanisms underlying toxicant-mediated disruption of steroidogenesis.
Reproductive Toxicology, 2014
Hexachlorobenzene and pentachlorobenzene accumulation and the effect on CYP1A1, SULT1A, COMT and steroid secretion in term placental tissue were determined. Explants of placental tissue were exposed to between 0.02 and 2 ng/ml HCBz or PeCBz for 6-72 h. Accumulation was measured by capillary gas chromatography and quadrupole mass spectrometry. CYP1A1, SULT1A, COMT activity and progesterone secretion were analysed by EIA. Protein expression was quantified by Western blot; 6% HCBz and 7% PeCBz were detected in the tissue. Fast induction of CYP1A1 activity and protein expression in the presence of HCBz were observed. HCBz increased, while PeCBz decreased COMT protein expression. The stimulatory effect of HCBz, and the inhibitory of PeCBz on progesterone secretion and CYP11A1 protein expression were noted. Later activation of CYP1A1, inhibition of COMT protein expression and progesterone secretion by PeCBz suggest greater exposure to PeCBz and pointing at PeCBz as the main factor responsible for the disruption of placental function.
Reproductive Toxicology, 2018
The present study was aimed to determine the effects of lactational exposure of PCBs (Aroclor 1254) on Leydig cellular steroidogenesis in F 1 progeny rats. Lactating dams were orally treated by gavage with different doses of PCBs (1, 2 and 5 mg/kg b.wt./day). Male progenies were sacrificed on PND60. Our results demonstrated that exposure to PCBs decreased the body weight, testis weight and anogenital distance (AGD) index in the F 1 progeny rats. Importantly, PCBs exposure reduced the serum levels of LH, testosterone and estradiol. Interestingly, PCBs caused a decrease in the Leydig cell population along with decreased activities of steroidogenic enzymes 3-and 17-HSD. Additionally, we observed a significant decrease in LHR, SR-B1, StAR protein, Cyp11a1, 3-HSD, Cyp17a1, 17-HSD, 5␣-reductase, Cyp19a1 and AR gene expression in the Leydig cells of progeny rats. In conclusion, our study demonstrates that lactational exposure of PCBs alters Leydig cellular steroidogenesis in the F 1 progeny rats.
Molecular Human Reproduction, 2014
Environmental contaminants binding to transcription factors, such as the aryl hydrocarbon receptor (AhR) and the alpha and gamma peroxisome proliferator-activated receptors (PPARs), contribute to adverse effects on the reproductive system. Expressing both the AhR and PPARs, the human granulosa cell line KGN offers the opportunity to investigate the regulatory mechanisms involved in receptor crosstalk, independent of overriding hormonal control. The aim of the present study was to investigate the impact of two environmental contaminants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, an AhR ligand) and di-(2-ethylhexyl) phthalate (DEHP, a PPAR ligand), on gonadotrophin sensitivity and estrogen synthesis in KGN cells. Accumulation of the DEHP metabolite mono-(2-ethylhexyl) phthalate (MEHP) in DEHP-exposed cells was measured by high-performance liquid chromatography mass spectrometry, thereby demonstrating DEHP metabolism to MEHP by KGN cells. By employing TCDD ( an AhR agonist), rosiglitazone (a PPARgamma agonist) or bezafibrate (a PPARalpha agonist), the presence of a functional AhR and PPAR cascade was confirmed in KGN cells. Cytotoxicity testing revealed no effect on KGN cell proliferation for the concentrations of TCDD and DEHP used in the current study. FSH-stimulated cells were exposed to TCDD, DEHP or a mix of both and estradiol synthesis was measured by enzyme-linked immunosorbent assay and gene expression by quantitative RT -PCR. Exposure decreased estradiol synthesis (TCDD, DEHP, mix) and reduced the mRNA expression of CYP19 aromatase (DEHP, mix) and FSHR (DEHP). DEHP induced the expression of the alpha and gamma PPARs and AhR, an effect which was inhibited by selective PPAR antagonists. Studies in the human granulosa cell line KGN show that the action of endocrine-disrupting chemicals may be due to a direct activation of AhR, for example by TCDD, and by a transactivation via PPARs, for example by DEHP, inducing subsequent transcriptional changes with a broad range of effects on granulosa cell function.
Toxicological Sciences, 2007
Residues of illegally used hormones are regularly detected in animal products, feed, or cocktails recovered at farms. In order to better understand the effects of dietary exposure to ethinyl estradiol (EE2, 0.03-1 mg/kg body weight [bw]) and zearalenone (ZEA, 0.03-1 mg/kg bw), an immature rat uterotrophic assay was performed and effects were studied at morphological, histological, and gene expression levels. Ligand-mediated coregulator recruitment by estrogen receptor a (ERa) was studied in vitro. Uterine weight and epithelial cell height were increased dose dependently after a 3-day oral exposure of rats to the highest tested doses of EE2 or ZEA, respectively. At low doses 0.03 mg/kg EE2 and 0.1 mg/kg ZEA, edema, and vacuolization could already be observed in some animals. Exposure to 1 mg/kg ZEA resulted in severe damage of the uterine epithelial layer. Our study suggests similar coregulator recruitment and gene expression patterns for the two estrogenic compounds. Main regulated pathways were remodeling of extracellular matrix, alternative complement activation, cell proliferation, and estrogen-mediated calcium signaling. The level of regulation differed between EE2 and ZEA, attributing a much lower estrogenic potency to ZEA than to EE2. A major difference was their ability to recruit coregulator inhibitor of kappa B beta and induce expression of the matrix metalloproteinase 7 gene (381.4-and 6.9-fold upregulation by EE2 and ZEA, respectively), which plays an important role in the maintenance of the integrity of the epithelial layer of the uterus during proliferation and growth. This observation may explain the observed differences at the histological level. by guest on December 28, 2015 http://toxsci.oxfordjournals.org/ Downloaded from 304 HENEWEER ET AL. by guest on December 28, 2015 http://toxsci.oxfordjournals.org/ Downloaded from FIG. 4. HE-stained uterus coupes which are representative for the rats of the control and treatment groups. Magnification was 3200. (A) Control animal showing a thin epithelial layer. (B) 0.03 lg/kg EE2: edema and vacuoles. (C) 0.1 mg/kg ZEA: edema and vacuoles. (D) 10 lg/kg EE2: high epithelium. (E) 10 mg/kg ZEA: degenerated epithelium. ESTROGENIC EFFECTS OF EE2 AND ZEA IN RAT 309 by guest on December 28, 2015 http://toxsci.oxfordjournals.org/ Downloaded from 312 HENEWEER ET AL. by guest on December 28, 2015