Metabolism-based polycyclic aromatic acetylene inhibition of CYP1B1 in 10T1/2 cells potentiates aryl hydrocarbon receptor activity.
Metabolism-based polycyclic aromatic acetylene inhibition of CYP1B1 in 10T1/2 cells potentiates aryl hydrocarbon receptor activity.
复制标题
10T1/2 细胞中基于代谢的多环芳香乙炔对 CYP1B1 的抑制可增强芳烃受体活性。
DOI：
10.1006/taap.1999.8794
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发表时间：
1999
影响因子：
3.8
通讯作者：
Jefcoate,CR
中科院分区：
文献类型：
--
作者：
Alexander,DL;Zhang,L;Foroozesh,M;Alworth,WL;Jefcoate,CR
我们使用基于多环芳烃 (PAH) 炔代谢的抑制剂来测试 CYP1B1 代谢是否与小鼠胚胎成纤维细胞 (MEF) 中芳烃受体 (AhR) 的激活有关。 1-乙炔基芘 (1EP) 选择性失活 C3H10T1/2 MEF 中的 CYP1B1 二甲基苯并蒽 (DMBA) 代谢；而 1-(1-丙炔基)芘 (1PP) 优先抑制 Hepa-1c1c7 小鼠肝癌细胞 (Hepa) 中的 CYP1A1 活性。在每种细胞类型中，用每种抑制剂 (0.1 μM) 处理 1 小时后，DMBA 代谢的 >90% 抑制逐渐逆转，然后增加至 2,3,7,8-四氯二苯并-对二恶英 (TCDD) 诱导（四倍刺激）时观察到的水平。结果发现，6小时后，0.1 μM 1EP和1PP分别最大程度地诱导10T1/2和Hepa细胞中CYP1B1和CYP1A1 mRNA水平。 1-乙基芘 (EtP) 缺乏可激活的乙炔部分，作为抑制剂和诱导剂的效果要差得多。 AhR 激活对于 1EP 诱导至关重要，这一点可以通过使用 AhR 拮抗剂和 AhR 缺陷 MEF 以及用一氧化碳 (CO) 抑制 DMBA 代谢后缺乏诱导来证明。即使在配体显着耗尽之前的早期阶段，CYP1B1 的抑制也与 AhR 激活的增强有关。 1EP 和 EtP 在刺激 AhR 核易位方面同样有效，尽管比 TCDD 慢 5-10 倍，并且不会产生 AhR 的显着下调。 TCDD 与寡核苷酸异生素反应元件相比，更广泛地激活 AhR/Arnt 复合物的形成，甚至在 1EP 浓度下（将 CYP1B1 mRNA 增加至相似水平），其作用范围远远大于 1EP 或 EtP。 CO 不影响这些对 EtP 的反应，尽管 CO 处理增强了 EtP 对 CYP1B1 mRNA 的诱导。这些差异表明 PAH/AhR 和 TCDD/AhR 复合物之间存在根本差异，其中 CYP1B1 代谢活性调节效力，而不是 AhR/Arnt 复合物的形成。
We have used polycyclic aromatic hydrocarbon (PAH) alkyne metabolism-based inhibitors to test whether CYP1B1 metabolism is linked to aryl hydrocarbon receptor (AhR) activation in mouse embryo fibroblasts (MEF). 1-ethynylpyrene (1EP) selectively inactivated CYP1B1 dimethylbenzanthracene (DMBA) metabolism in C3H10T1/2 MEFs; whereas 1-(1-propynyl)pyrene (1PP) preferentially inhibited CYP1A1 activity in Hepa-1c1c7 mouse hepatoma cells (Hepa). In each cell type >90% inhibition of DMBA metabolism after 1 h treatment with each inhibitor (0.1 μM) was progressively reversed and then increased to levels seen with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induction (fourfold stimulation). It was found that 0.1 μM 1EP and 1PP maximally induce CYP1B1 and CYP1A1 mRNA levels in10T1/2 and Hepa cells, respectively, after 6 h. 1-Ethylpyrene (EtP), which lacks the activatable acetylene moiety, was far less effective as an inhibitor and as an inducer. AhR activation is essential for 1EP induction as evidenced by the use of AhR antagonists and AhR-deficient MEFs and absence of induction following inhibition of DMBA metabolism with carbon monoxide (CO). Inhibition of CYP1B1 was linked to enhanced AhR activation even at early stages prior to significant ligand depletion. 1EP and EtP were similarly effective in stimulating AhR nuclear translocation, though 5–10 times slower compared with TCDD, and produced no significant down-regulation of the AhR. TCDD activated AhR/Arnt complex formation with an oligonucleotide xenobiotic response element far more extensively than 1EP or EtP, even at concentrations of 1EP that increased CYP1B1 mRNA to similar levels. CO did not influence these responses to EtP, event hough CO treatment potentiated EtP induction of CYP1B1 mRNA. These differences suggest a fundamental difference between PAH/AhR and TCDD/AhR complexes where CYP1B1 metabolic activity regulates the potency, rather than the formation of the AhR/Arnt complex.