School of Life Sciences, Chinese University, Sha Tin, Hong Kong SAR, China.
School of Life Sciences, Chinese University, Sha Tin, Hong Kong SAR, China.
Chemosphere. 2016 Mar;147:467-76. doi: 10.1016/j.chemosphere.2015.12.083. Epub 2016 Jan 19.
We evaluated the individual and joint estrogenic effects of cadmium (Cd(2+)) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the zebrafish liver (ZFL) cell line, zebrafish embryo, larvae and the liver of adult zebrafish. The mRNA expression of vtg1 was inhibited by Cd(2+), but unaffected by TCDD in ZFL cells. Similar changes in the mRNA levels of ERα, ERβ1, ERβ2 and GPER (G protein coupled estrogen receptor) in ZFL cells were also observed. Deletion mutants of vtg1 gene promoters were constructed to investigate transcriptional regulation, and we found that all of the constructs failed to respond to TCDD or Cd(2+). However, after co-transfection with a vtg1 promoter-luciferase construct to the ERα, ERβ1, ERβ2 and GPER expression vectors, decreased luciferase activity was observed in the ERα co-transfection group after treatment with Cd(2+), suggesting that ERα participates in vtg1 transcriptional regulation and is affected by Cd(2+). Differences in the regulation of the mRNA levels of these genes were also observed between different developmental stages and between the livers of male and female zebrafish.
我们评估了镉（Cd(2+)）和 2,3,7,8-四氯二苯并对二恶英（TCDD）对斑马鱼肝脏（ZFL）细胞系、斑马鱼胚胎、幼虫和成年斑马鱼肝脏的单独和联合雌激素效应。在 ZFL 细胞中，Cd(2+)抑制 vtg1 的 mRNA 表达，但 TCDD 对其没有影响。在 ZFL 细胞中，ERα、ERβ1、ERβ2 和 GPER（G 蛋白偶联雌激素受体）的 mRNA 水平也观察到类似的变化。构建了 vtg1 基因启动子缺失突变体以研究转录调控，我们发现所有构建体都不能响应 TCDD 或 Cd(2+)。然而，在用 Cd(2+)处理后，与 ERα、ERβ1、ERβ2 和 GPER 表达载体共转染 vtg1 启动子-荧光素酶构建体后，观察到 ERα 共转染组的荧光素酶活性降低，表明 ERα 参与 vtg1 转录调控并受 Cd(2+)影响。在不同发育阶段和雄性和雌性斑马鱼肝脏之间，这些基因的 mRNA 水平的调节也存在差异。
