Comparison of gene expression patterns between 2,3,7,8-tetrachlorodibenzo-p-dioxin and a natural arylhydrocarbon receptor ligand, indirubin
Comparison of gene expression patterns between 2,3,7,8-tetrachlorodibenzo-p-dioxin and a natural arylhydrocarbon receptor ligand, indirubin
复制标题
DOI：
10.1093/toxsci/kfh129
复制
发表时间：
2004-07-01
影响因子：
3.8
通讯作者：
Matsuda, T
中科院分区：
文献类型：
--
作者：
Adachi, J;Mori, Y;Matsuda, T
靛玉红是从人尿中分离出的天然芳烃受体（AhR）配体。我们以前报道过，在酵母分析系统中，它比典型配体2,3,7,8-四氯二苯并-对二恶英（TCDD）更有效。本研究采用尼龙膜为基础的cDNA阵列，比较了暴露于10 nM靛玉红或TCDD的HepG2细胞中1176个基因的基因表达变化，以阐明在转录水平上的毒性差异。TCDD和靛玉红的基因表达谱非常相似。在tcdd处理和靛玉红处理的细胞中，上调基因数（倍数变化大于等于2.0）分别为11个和4个，下调基因数（倍数变化小于等于0.5）分别为17个和21个。实时逆转录聚合酶链反应证实细胞色素P450 (CYP) 1A1、1A2、19A1、胰岛素样生长因子结合蛋白1 （IGFBP1）和IGFBP10上调。CYP1A1和CYP1A2 mrna仅被1 pM的靛玉红诱导，而10 pM的TCDD则不能诱导。在时间过程实验中，吲哚红对CYP1A1 mRNA有短暂的诱导作用。靛玉红也被CYP1A1代谢并失去其配体活性。靛玉红具有较低的解离常数，是CYP1A1良好的底物。我们的研究结果表明，靛玉红通过AhR介导的CYP1A1的诱导快速激活自身代谢，这一特点与靛玉红是AhR的生理配体的观点一致。
Indirubin is a natural arylhydrocarbon receptor (AhR) ligand isolated from human urine. We previously reported that it was more potent than the prototypical ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a yeast assay system. Here we compared gene expression changes in HepG2 cells exposed to 10 nM of indirubin or TCDD using nylon-membrane-based cDNA arrays with 1176 genes to elucidate the toxic differences at the transcriptional level. The gene expression profiles for TCDD and indirubin were very similar. The number of up-regulated genes (fold change greater than or equal to2.0) was 11 and 4 and the number of down-regulated genes (fold change less than or equal to0.5) was 17 and 21 in TCDD-treated and indirubin-treated cells, respectively. Cytochrome P450 (CYP) 1A1, 1A2, 19A1, insulin-like growth factor binding protein 1 (IGFBP1), and IGFBP10 were confirmed to be up-regulated using real-time reverse transcription polymerase chain reaction. CYP1A1 and CYP1A2 mRNAs were induced by as little as 1 pM of indirubin, whereas they were not induced by 10 pM of TCDD. In the time-course experiment, CYP1A1 mRNA was induced by indirubin transiently. Indirubin was also metabolized by CYP1A1 and lost its ligand activity. Indirubin would appear to be a good substrate of CYP1A1 given its low dissociation constant. Our results suggest that indirubin rapidly activates its own metabolism via AhR-mediated induction of CYP1A1 and this characteristic is consistent with the notion that indirubin is a physiological ligand of AhR.