Reference - Detail
|Author||Ernst J, Jann JC, Biemann R, Koch HM, Fischer B.|
|Title||Effects of the environmental contaminants DEHP and TCDD on estradiol synthesis and aryl hydrocarbon receptor and peroxisome proliferator-activated receptor signalling in the human granulosa cell line KGN.|
|Journal||Mol. Hum. Reprod.|
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.
|MeSH||Basic Helix-Loop-Helix Transcription Factors / agonists Basic Helix-Loop-Helix Transcription Factors / antagonists & inhibitors Basic Helix-Loop-Helix Transcription Factors / genetics Basic Helix-Loop-Helix Transcription Factors / metabolism Bezafibrate / pharmacology Biotransformation Cell Proliferation / drug effects Diethylhexyl Phthalate / analogs & derivatives Diethylhexyl Phthalate / antagonists & inhibitors Diethylhexyl Phthalate / metabolism Diethylhexyl Phthalate / pharmacology* Endocrine Disruptors / chemistry Endocrine Disruptors / metabolism Endocrine Disruptors / pharmacology* Environmental Pollutants / antagonists & inhibitors Environmental Pollutants / metabolism Environmental Pollutants / pharmacology* Estradiol / metabolism Female Follicle Stimulating Hormone / antagonists & inhibitors Follicle Stimulating Hormone / genetics Follicle Stimulating Hormone / metabolism Gene Expression Regulation / drug effects Granulosa Cells / drug effects* Granulosa Cells / metabolism Humans Ligands PPAR alpha / agonists PPAR alpha / antagonists & inhibitors PPAR alpha / genetics PPAR alpha / metabolism PPAR gamma / agonists PPAR gamma / antagonists & inhibitors PPAR gamma / genetics PPAR gamma / metabolism Peroxisome Proliferators / antagonists & inhibitors Peroxisome Proliferators / metabolism Peroxisome Proliferators / pharmacology* Plasticizers / chemistry Plasticizers / metabolism Plasticizers / pharmacology Polychlorinated Dibenzodioxins / metabolism Polychlorinated Dibenzodioxins / pharmacology* Receptors, Aryl Hydrocarbon / agonists Receptors, Aryl Hydrocarbon / antagonists & inhibitors Receptors, Aryl Hydrocarbon / genetics Receptors, Aryl Hydrocarbon / metabolism Rosiglitazone Signal Transduction / drug effects* Thiazolidinediones / pharmacology|
|WOS Category||OBSTETRICS & GYNECOLOGY REPRODUCTIVE BIOLOGY DEVELOPMENTAL BIOLOGY|
|Human and Animal Cells|