Boyce-Derricott Josh, Nagler James J, Cloud J G
Department of Biological Sciences and Center for Reproductive Biology, University of Idaho, P.O. Box 443051, Moscow, ID 83844, USA.
Gen Comp Endocrinol. 2009 Mar;161(1):73-8. doi: 10.1016/j.ygcen.2008.11.022. Epub 2008 Dec 3.
The complete nuclear estrogen receptor family in rainbow trout consists of two subtypes (ERalpha and ERbeta) each of which consists of two isoforms (alpha1/alpha2 and beta1/beta2). Transcription rate and mRNA stability of ERalpha1 is affected by 17beta-estradiol (E2) but no information on estrogen regulation exists for the other isoforms. The objective of this study was to compare the mRNA expression patterns of the four ER isoforms in the liver of male trout and in immortalized trout hepatocyte lines (RTH-149 and SOB-15) treated with E2 or 17alpha-ethynylestradiol (EE2) using quantitative RT-PCR. To determine the in vivo dose-response, isogenic male trout were injected intra-peritoneally with 0, 1.5, 15 or 150 microg E2 or an equimolar amount of EE2 and the liver sampled 24 h later. Treatment with either E2 or EE2 significantly (p<0.05) increased the level of ERalpha1 mRNA at all doses tested compared to vehicle, while the response of mRNAs for the other three isoforms did not change. The in vitro dose-response was tested by treating both cell lines with 0, 0.1, 1.0 or 10.0 microM E2 for 48 h. In RTH-149 cells, ERalpha1, ERalpha2 and ERbeta2 mRNAs were significantly higher in cells incubated with 10 microM E2 as compared to cells treated with only vehicle (p<0.05). In SOB-15 cells, ERalpha2 and ERbeta1 mRNAs were significantly higher in cells incubated with 1.0 microM E2 as compared to cells incubated with only vehicle (p<0.05). These results support the conclusion that the mRNAs for the four ER isoforms respond differentially to estrogen regulation.
虹鳟鱼完整的核雌激素受体家族由两种亚型（雌激素受体α和雌激素受体β）组成，每种亚型又包含两种异构体（α1/α2和β1/beta2）。雌激素受体α1的转录速率和mRNA稳定性受17β-雌二醇（E2）影响，但其他异构体的雌激素调节信息尚不存在。本研究的目的是使用定量逆转录聚合酶链反应（RT-PCR）比较雄性鳟鱼肝脏以及用E2或17α-乙炔基雌二醇（EE2）处理的永生化鳟鱼肝细胞系（RTH-149和SOB-15）中四种雌激素受体异构体的mRNA表达模式。为了确定体内剂量反应，将同基因雄性鳟鱼腹腔注射0、1.5、15或150微克E2或等摩尔量的EE2，24小时后采集肝脏样本。与溶剂对照组相比，在所有测试剂量下，用E2或EE2处理均显著（p<0.05）提高了雌激素受体α1 mRNA的水平，而其他三种异构体mRNA的反应未发生变化。通过用0、0.1、1.0或10.0微摩尔E2处理两种细胞系48小时来测试体外剂量反应。在RTH-149细胞中，与仅用溶剂处理的细胞相比，用10微摩尔E2孵育的细胞中雌激素受体α1、雌激素受体α2和雌激素受体β2 mRNA显著更高（p<0.05）。在SOB-15细胞中，与仅用溶剂孵育的细胞相比，用1.0微摩尔E2孵育的细胞中雌激素受体α2和雌激素受体β1 mRNA显著更高（p<0.05）。这些结果支持以下结论：四种雌激素受体异构体的mRNA对雌激素调节的反应不同。
