Jiao Baowei, Yeung Eric K C, Chan Chi Bun, Cheng Christopher H K
Environmental Science Program, Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
J Cell Biochem. 2008 Dec 15;105(6):1399-409. doi: 10.1002/jcb.21960.
Endocrine disruptors refer to chemical compounds in the environment which interfere with the endocrine systems of organisms. Among them, environmental estrogens pose serious problems to aquatic organisms, in particular fish. It is therefore important and necessary to have a fast and low-cost system to screen the large number of different chemical compounds in the aquatic environment for their potential endocrine disrupting actions. In this study, a screening platform was developed to detect xenoestrogens in the aquatic environment using the fission yeast Schizosaccharomyces pombe, and applied for compound screening. The aim was to demonstrate any significant potential differences between the fish screening system and the human screening system. To this end, a yeast expression vector harboring a fish estrogen receptor alpha and a reporter vector containing the estrogen responsive element fused with the Escherichia coli LacZ gene were constructed. After transformation with these two vectors, the transformed yeast clones were confirmed by Western blotting and selected on the basis of the beta-galactosidase activity. In this transgenic yeast system, the natural estrogen (estradiol) and other known xenoestrogens such as diethylstilbestrol, bisphenol A, genistein and dichloro-diphenyl-trichloroethane exhibited dose-dependent activities. Using this system, more than 40 putative endocrine disruptors including phytoestrogens, pesticides, herbicides, industrial dyes and other industrial chemicals were screened. Ten of them were demonstrated to exhibit estrogenic actions. Industrial dyes such as malachite green (MG) that disrupt thyroid hormone synthesis are extensively used and are widely distributed in the aquatic environment. Using this system, MG did not show any estrogenic action, but was demonstrated to exhibit anti-estrogenic activity.
内分泌干扰物是指环境中干扰生物体内分泌系统的化合物。其中，环境雌激素给水生生物，尤其是鱼类带来了严重问题。因此，拥有一个快速且低成本的系统来筛选水环境中大量不同化合物的潜在内分泌干扰作用非常重要且必要。在本研究中，开发了一个利用粟酒裂殖酵母来检测水环境中异雌激素的筛选平台，并将其应用于化合物筛选。目的是证明鱼类筛选系统和人类筛选系统之间是否存在任何显著的潜在差异。为此，构建了一个携带鱼类雌激素受体α的酵母表达载体和一个含有与大肠杆菌LacZ基因融合的雌激素反应元件的报告载体。用这两个载体转化后，通过蛋白质印迹法确认转化的酵母克隆，并根据β-半乳糖苷酶活性进行筛选。在这个转基因酵母系统中，天然雌激素（雌二醇）和其他已知的异雌激素，如己烯雌酚、双酚A、染料木黄酮和滴滴涕，表现出剂量依赖性活性。利用该系统，筛选了40多种包括植物雌激素、农药、除草剂、工业染料和其他工业化学品在内的潜在内分泌干扰物。其中10种被证明具有雌激素作用。广泛使用的、在水环境中广泛分布的破坏甲状腺激素合成的工业染料，如孔雀石绿（MG），在该系统中未显示出任何雌激素作用，但被证明具有抗雌激素活性。
