Differential regulation of mouse Ah receptor gene expression in cell lines of different tissue origins
Differential regulation of mouse Ah receptor gene expression in cell lines of different tissue origins
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DOI：
10.1006/abbi.1996.0378
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发表时间：
1996-09-01
影响因子：
3.9
通讯作者：
Puga, A
中科院分区：
文献类型：
--
作者：
FitzGerald, CT;FernandezSalguero, P;Puga, A
二恶英结合Ah受体（AHR）是一种配体激活的转录因子，调节几种药物代谢酶的表达，并与免疫抑制、致畸、细胞特异性增生和某些类型的恶性肿瘤和毒性有关。为了研究小鼠Ah受体基因（Ahr）的组织特异性调节，我们研究了嵌合缺失构建体，其含有Ahr 5'侧翼区和萤火虫荧光素酶报告基因（Luc）。在五种已建立的小鼠细胞系中进行瞬时转染试验：Hepa-1c 1c 7（源自肝癌）、JB 6-C1 41-5a（表皮）、MLE-12（肺上皮）、F9（胚胎癌）和NIH/3 T3（成纤维细胞）。细胞系的处理包括：二恶英（2，3，7，8-四氯二苯并-p-二恶英）、视黄酸（RA）、环腺苷3 '：5'-单磷酸（cAMP）或12-O-十三烷酰基佛波醇13-乙酸酯（TPA）。表达水平另一方面，AHR mRNA稳态水平的测量也证实了这一发现。在除F9细胞外的所有细胞系中，用含有78 bp Ahr启动子序列的构建体观察到最大组成型表达，所述Ahr启动子序列包括转录因子Sp1的几个推定结合位点。相反，在F9细胞中，包含-174和-78之间的序列导致组成型表达的四倍刺激，表明其他转录因子在这些细胞中的Ahr基因表达中是重要的。在MLE-12和41-5a细胞中，用二恶英、RA、cAMP或TPA处理显著降低表达。在cAMP处理的MLE-12和F9细胞中观察到类似的抑制作用;通过RT-PCR测量AHR mRNA稳态水平证实了这一结果。这些结果表明Ahr基因的上调和下调均发生，并表现出组织和细胞类型特异性。(C)出版社：Academic Press，Inc.
The dioxin-binding Ah receptor (AHR) is a ligand-activated transcription factor that regulates the expression of several drug-metabolizing enzymes and has been implicated in immunosuppression, teratogenesis, cell-specific hyperplasia, and certain types of malignancies and toxicities. In order to examine tissue-specific regulation of the mouse Ah receptor gene (Ahr), we studied chimeric deletion constructs, containing the Ahr 5' flanking region and the firefly luciferase reporter gene (Luc). Transient transfection assays were performed in five established mouse cell lines: Hepa-1c1c7 (derived from hepatoma), JB6-C1 41-5a (epidermis), MLE-12 (lung epithelium), F9 (embryonal carcinoma), and NIH/3T3 (fibroblasts). Treatment of the cell lines included: dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin), retinoic acid (RA), cyclic adenosine 3':5'-monophosphate (cAMP), or 12-O-tertrdecanoylphorbol 13-acetate (TPA). Expression levels another, this finding was also confirmed by measurements of AHR mRNA steady-state levels. In all cell lines except F9 cells, maximal constitutive expression was observed with constructs containing 78 bp of Ahr promoter sequences, which include several putative binding sites for the transcription factor Sp1. In contrast, in F9 cells, inclusion of sequences between -174 and -78 resulted in a fourfold stimulation of constitutive expression, suggesting that other transcription factors are important in Ahr gene expression in these cells. In MLE-12 and 41-5a cells, expression was significantly decreased by treatment with dioxin, RA, cAMP, or TPA. A similar inhibitory effect was observed in cAMP-treated MLE-12 and F9 cells; this result was confirmed by RT-PCR measurements of AHR mRNA steady-state levels. These results indicate that both up- and down-regulation of the Ahr gene occur and exhibit tissue- and cell-type specificity. (C) 1996 Academic Press, Inc.