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
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
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DOI：
10.1093/molehr/gau045
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发表时间：
2014-09-01
影响因子：
4
通讯作者：
Fischer, Bernd
中科院分区：
文献类型：
--
作者：
Ernst, Jana;Jann, Johann-Christoph;Fischer, Bernd
环境污染物与转录因子结合，如芳烃受体（AhR）和α和γ过氧化物酶体增殖激活受体（PPARs），有助于对生殖系统产生不利影响。同时表达AhR和ppar的人颗粒细胞系KGN为研究受体串扰的调节机制提供了机会，而不受激素控制的影响。本研究的目的是研究两种环境污染物，2,3,7,8-四氯二苯并-对二恶英（TCDD，一种ahr配体）和邻苯二甲酸二（2-乙基己基）酯（DEHP，一种ppar配体）对KGN细胞促性腺激素敏感性和雌激素合成的影响。采用高效液相色谱-质谱法测定DEHP暴露细胞中邻苯二甲酸单-（2-乙基己基）酯（MEHP）的积累，从而证实了DEHP在KGN细胞中对MEHP的代谢。通过使用TCDD（一种AhR激动剂）、罗格列酮（一种PPAR激动剂）或贝扎布特（一种PPAR激动剂），证实了KGN细胞中存在功能性AhR和PPAR级联反应。细胞毒性试验显示，本研究中使用的TCDD和DEHP浓度对KGN细胞增殖没有影响。将fsh刺激的细胞暴露于TCDD、DEHP或两者的混合物中，用酶联免疫吸附法检测雌二醇合成，用定量RT-PCR检测基因表达。暴露降低雌二醇合成（TCDD， DEHP, mix），降低CYP19芳香化酶（DEHP, mix）和FSHR (DEHP) mRNA表达。DEHP诱导α和γ PPAR和AhR的表达，选择性PPAR拮抗剂抑制了这一作用。对人颗粒细胞系KGN的研究表明，内分泌干扰化学物质的作用可能是由于AhR的直接激活，例如TCDD，以及通过ppar的反激活，例如DEHP，诱导随后的转录变化，对颗粒细胞功能产生广泛的影响。
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 AhRligand) and di-(2-ethylhexyl) phthalate (DEHP, a PPARligand), 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.