Demonstration of 2,3,7,8-tetrachlorodibenzo-p-dioxin attenuation of P450 steroidogenic enzyme mRNAs in rat granulosa cell in vitro by competitive reverse transcriptase-polymerase chain reaction assay
Demonstration of 2,3,7,8-tetrachlorodibenzo-p-dioxin attenuation of P450 steroidogenic enzyme mRNAs in rat granulosa cell in vitro by competitive reverse transcriptase-polymerase chain reaction assay
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DOI：
10.1016/s0303-7207(00)00245-8
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发表时间：
2000-06-20
影响因子：
4.1
通讯作者：
Hutz, RJ
中科院分区：
文献类型：
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作者：
Dasmahapatra, AK;Wimpee, BAB;Hutz, RJ
本研究通过观察2，3，7，8-四氯二苯并-对-二恶英（TCDD）对青春期前（PP）和成年（A）大鼠离体颗粒细胞（GC）雌激素分泌、芳香化酶活性和甾体生成酶P450 SCC、3 β-HSDI、P450 arom mRNAs表达的影响;以及AHR信号通路的组分-CYP 1A 1、芳香烃受体（AHR）和AHR核转运蛋白（ARNT）。在PP和A大鼠GC中，TCDD（3.1 nM）在48小时减少雌激素分泌而不改变芳香酶活性。加入FSH（50 ng/ml）增加芳香化酶活性在CC与或不TCDD。FSH诱导的芳香化酶活性在48 h时被TCDD（3.1 nM）显著降低。半定量RT-PCR结果显示，TCAP作用24和48 h后，CYP 1A 1 mRNA表达显著增加，而竞争性RT-PCR结果显示，P450 SCC和P450 arom mRNA表达显著减少。所有类固醇生成酶的mRNA显着低于成人比PP GC。我们的结论是，在大鼠GC中，TCDD调节参与类固醇生物合成级联的细胞色素P450酶的水平。这种效应可能是由于AHR与编码这些酶的基因中存在的二恶英反应元件相互作用。(C)2000爱思唯尔科学爱尔兰有限公司保留所有权利。
We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in prepubertal (PP) and adult (A) rat granulosa cells (GC) in vitro by examining the changes in estrogen secretion, aromatase enzyme activity and mRNAs for steroidogenic enzymes P450scc, 3 beta-HSDI, P450arom; and for components of the AHR signaling pathway-CYP1Al, aromatic hydrocarbon receptor (AHR), and the AHR nuclear translocator protein (ARNT). In PP and A rat GC, TCDD (3.1 nM) reduced estrogen secretion at 48 h without altering aromatase enzyme activity. Addition of FSH (50 ng/ml) increased aromatase activity in CC with or without TCDD. FSH-induced aromatase activity was significantly reduced by TCDD (3.1 nM) at 48 h. Semi-quantitative RT-PCR showed a significant increase in CYP1Al mRNA both at 24 and 48 h with TCAP, while a significant reduction in P450scc and P450arom mRNA was observed with competitive RT-PCR. All steroidogenic enzyme mRNAs were significantly lower in adults than in PP GC. We conclude that in rat GC, TCDD modulates the level of cytochrome P450 enzymes involved in the steroid biosynthetic cascade. This effect may be attributable to AHR interaction with dioxin-responsive elements present in the genes encoding these enzymes. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.