Lemini Cristina, Jaimez Ruth, Pozas Rocio, Franco Yanira, Avila María Estela, Figueroa Alejandra, Medina Martha, Lemus Ana Elena, García-Becerra Rocío, Ordaz-Rosado David, Larrea Fernando
Departamento de Farmacología, Facultad de Medicina, UNAM, Mexico.
Departamento de Farmacología, Facultad de Medicina, UNAM, Mexico.
J Steroid Biochem Mol Biol. 2015 Mar;147:40-7. doi: 10.1016/j.jsbmb.2014.11.019. Epub 2014 Nov 21.
17β-amino-1,3,5(10)estratrien-3-ol (17βAE2), is the 17β-aminoestrogens prototype possessing anticoagulant activity, contrasting with the procoagulant effects of 17β-estradiol (17βE2). Its estrogenicity profile has not been reported, and it was evaluated by uterotrophic assay, estrogen receptor binding affinity and its ability to induce gene transcription of the human estrogen receptor (hER)α mediated in a Saccharomyces cerevisiae yeast expression system. Additionally, 17βAE2 and 17αAE2 were compared with 17βE2 in HeLa cells co-transfected with expression vectors for hERα or hERβ subtypes and for an estrogen-responsive reporter gene. Immature female CD1 mice and Wistar rats (21 days old) were treated for three days with 17βAE2 (10-5000 μg/kg), 17βE2 (0.001-1000 μg/kg) or vehicle (propylenglycol 10 ml/kg) and uterine weights were estimated. 17βAE2 increased uterine weight in a dose-dependent manner. The effective dose (ED)50 uterine weight values: 17βAE2=552 and 764 μg/kg (17βE2=4.8 and 16 μg/kg) and their relative uterotrophic potency were 0.86 and 2.1 (17βE2=100) in mice and rats, respectively. 17βAE2 competed with [(3)H]E2 for the estrogen receptor. The 17βAE2 relative binding affinities (RBAs) were: 0.074; Ki=2.2×10(-6)M (17βE2=100; Ki=1.6×10(-9)M); 0.029 and Ki=3.8×10(-6)M (17βE2=100; Ki=1.1×10(-9)M) for mice and rats uteri respectively. 17βAE2 activated hERα-mediated β-galactosidase transcription activity in the yeast system co-transfected with hERα gene. 17βAE2 effective concentration (EC)50=1.82 μM (17βE2=2.14 nM) with a relative potency of 0.12 (17βE2=100). These transactivation effects were abolished by the antagonist fulvestrant (ICI 182,780), similarly to 17βE2. 17βAE2 and 17αAE2 bind with low relative affinity to hERα and hERβ. Both induced hER-mediated reporter gene transactivation in a dose-response manner. The overall results provide evidence that 17βAE2 has a weak agonist estrogenic action greatly mediated through the hERβ and to a lesser extent the hERα at genomic level.
17β - 氨基 - 1,3,5(10) - 雌甾三烯 - 3 - 醇（17βAE2）是具有抗凝活性的17β - 氨基雌激素原型，与17β - 雌二醇（17βE2）的促凝血作用形成对比。其雌激素特性尚未见报道，本研究通过子宫增重试验、雌激素受体结合亲和力及其在酿酒酵母表达系统中介导的诱导人雌激素受体（hER）α基因转录的能力对其进行了评估。此外，在共转染了hERα或hERβ亚型表达载体以及雌激素反应性报告基因的HeLa细胞中，将17βAE2和17αAE2与17βE2进行了比较。对未成熟雌性CD1小鼠和Wistar大鼠（21日龄）用17βAE2（10 - 5000μg/kg）、17βE2（0.001 - 1000μg/kg）或赋形剂（丙二醇10ml/kg）处理三天，并测定子宫重量。17βAE2以剂量依赖性方式增加子宫重量。小鼠和大鼠的有效剂量（ED）50子宫重量值分别为：17βAE2 = 552和764μg/kg（17βE2 = 4.8和16μg/kg），其相对子宫增重效力分别为0.86和2.1（17βE2 = 100）。17βAE2与[³H]E2竞争雌激素受体。17βAE2在小鼠和大鼠子宫中的相对结合亲和力（RBAs）分别为：0.074；Ki = 2.2×10⁻⁶M（17βE2 = 100；Ki = 1.6×10⁻⁹M）；0.029和Ki = 3.8×10⁻⁶M（17βE2 = 100；Ki = 1.1×10⁻⁹M）。在与hERα基因共转染的酵母系统中，17βAE2激活了hERα介导的β - 半乳糖苷酶转录活性。17βAE2的有效浓度（EC）50 = 1.82μM（17βE2 = 2.14 nM）,相对效力为0.12（17βE2 = 100）。与17βE2类似，拮抗剂氟维司群（ICI 182,780）消除了这些反式激活作用。17βAE2和17αAE2与hERα和hERβ的相对结合亲和力较低。二者均以剂量反应方式诱导hER介导的报告基因反式激活。总体结果表明，17βAE2在基因组水平上具有弱激动剂雌激素作用，主要通过hERβ介导，在较小程度上通过hERα介导。
