Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institute, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China.
Acta Pharmacol Sin. 2013 Mar;34(3):373-9. doi: 10.1038/aps.2012.168. Epub 2013 Jan 21.
Benzothiophene compounds are selective estrogen receptor modulators (SERMs), which are recently found to activate antioxidant signaling. In this study the molecular mechanisms of antioxidant signaling activation by benzothiophene compound BC-1 were investigated.
HepG2 cells were stably transfected with antioxidant response element (ARE)-luciferase reporter (HepG2-ARE cells). The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in HepG2-ARE cells was suppressed using siRNA. The metabolites of BC-1 in rat liver microsome incubation were analyzed using LC-UV and LC-MS.
Addition of BC-1 (5 μmol/L) in HepG2-ARE cells resulted in a 17-fold increase of ARE-luciferase activity. Pretreatment with the estrogen receptor agonist E2 (5 μmol/L) or antagonist ICI 182,780 (5 μmol/L) did not affect BC-1-induced ARE-luciferase activity. However, transfection of the cells with anti-Nrf2 siRNA suppressed this effect by 79%. Addition of BC-1 in rat microsome incubation resulted in formation of di-quinone methides and o-quinones, followed by formation of GSH conjugates. BC-1 analogues with hydrogen (BC-2) or fluorine (BC-3) at the 4' position did not form the di-quinone methides. Both BC-2 and BC-3 showed comparable estrogenic activity with BC-1, but did not induce ARE-luciferase activity in HepG2-ARE cells.
Benzothiophene compound BC-1 activates ARE signaling via reactive metabolite formation that is independent of estrogen receptors.
苯并噻吩类化合物是选择性雌激素受体调节剂（SERMs），最近发现它们能激活抗氧化信号。本研究旨在探讨苯并噻吩化合物 BC-1 激活抗氧化信号的分子机制。
用抗氧化反应元件（ARE）-荧光素酶报告基因（HepG2-ARE 细胞）稳定转染 HepG2 细胞。用 siRNA 抑制 HepG2-ARE 细胞中核因子红细胞 2 相关因子 2（Nrf2）的表达。用 LC-UV 和 LC-MS 分析大鼠肝微粒体孵育物中 BC-1 的代谢物。
BC-1（5μmol/L）加入 HepG2-ARE 细胞后，ARE 荧光素酶活性增加 17 倍。用雌激素受体激动剂 E2（5μmol/L）或拮抗剂 ICI 182,780（5μmol/L）预处理并不影响 BC-1 诱导的 ARE 荧光素酶活性。然而，用抗 Nrf2 siRNA 转染细胞可使该作用抑制 79%。BC-1 加入大鼠微粒体孵育物中可形成二醌甲醚和邻醌，随后形成 GSH 结合物。在 4'位带有氢（BC-2）或氟（BC-3）的 BC-1 类似物不能形成二醌甲醚。BC-2 和 BC-3 与 BC-1 具有相似的雌激素活性，但不能诱导 HepG2-ARE 细胞中 ARE 荧光素酶活性。
苯并噻吩化合物 BC-1 通过形成与雌激素受体无关的反应性代谢物激活 ARE 信号。
