子宫内膜雌激素受体的细胞化学电镜研究

用作者自行设计的标记配体(雌激素-辣根过氧化物酶-胶体金)与标本中的雌激素受体结合,在电镜下观察标记复合物的分布,进行定量、定位分析。共观察了正常增生期内膜10例,腺癌内膜6例。结果发现,细胞浆与细胞核内均存在游离雌激素受体(ER),细胞核内密度高于细胞浆内,“二步机制”不能解释此结果。我们认为,在雌激素作用过程中,浆受体与核受体共同起作用。本文结果又表明,内膜间质细胞和腺细胞的ER 含量与分布情况无显著差异,进一步支持了子宫内膜周期变化和出血机制中的“间质理论”。     

应用改良的E—screen实验评估天然物质的类雌激素活性

目的:改良E-screen实验,提高其筛选具有雌激素样作用物质的准确性.方法:构建雌激素受体反义RNA表达质粒pCASER,以脂质体转染MCF-7细胞,G418筛选阳性克隆.PCR检测雌激素受体的DNA是否整和地MCF-7细胞的基因组DNA中,Westernblot检测雌激素受体的表达;MTT法检测细胞的增殖.结果:筛选出一株雌激素受体反义RNA表达克隆(MTASER).17β-雌二醇,金雀异黄素,Dro-loxifen,Miyabenol和Kobophenol在一定浓度均可促进MCF-7细胞增殖,且对MCF-7的促增殖作用大于对MTASER的促增殖作用;表皮生长因子对两株细胞的促增殖作用的差别无显著意义.结论:改良的E-screen实验筛选具有雌激素样作用物质的准确性高于通常的E-screen实验.     

选择性雌激素受体调节药对雌激素受体α/β活性的诱导作用

目的：探讨选择性雌激素受体调节药(SERMs)对雌激素受体(ER)α/β活性的诱导作用。方法：通过基因转染方法将pSVhER和荧光素酶报道基因载体ER Etk Luc瞬时共转染至乳腺癌细胞株MDA MB 231，转染后的细胞分别用1 nmol·L 1 17β雌二醇(E2)、17αE2、雌酮、雷洛昔芬、4羟基 他莫昔芬(4OH TAM)和柠檬酸他莫昔芬处理细胞24 h，采用荧光素酶报道基因分析方法测定ERα/β活性。结果： 雷洛昔芬和他莫昔芬具有明显激活ERα活性作用，他莫昔芬对ERβ活性的诱导作用明显较ERα弱，雷洛西芬几乎不诱导ERβ活性。结论：SERMs主要是通过激活ERα发挥抗雌激素作用，而对ERβ的诱导作用明显较弱。     

雌激素对血管平滑肌细胞凋亡的影响

目的 :观察雌激素对血管平滑肌细胞 (SMC)凋亡的影响。方法 :以大鼠为对象 ,观察正常对照组、去卵巢组及去卵巢 +雌二醇治疗组大鼠血管平滑肌细胞凋亡的关系。结果 :雌二醇治疗组血管平滑肌细胞凋亡较去卵巢组相比明显减少(P>0 .0 5 ) ,与正常对照组比较差别无显著性意义 (P >0 .0 5 )。结论 :雌二醇对血管平滑肌细胞的凋亡有抑制作用 ,可能是其预防动脉粥样硬化的机制     

孕马尿提取物中4种化学成分的雌激素活性研究

目的研究孕马尿提取物中4种化学成分的雌激素活性。方法研究4种成分3β-羟基-5α-16-孕甾烷-20-酮(3β-hydroxy-5α-pregn-16-en-20-one,HP)、5β-孕甾烷-3β,16α,20α-醇(5β-pregnane-3β,16α,20α-triol,PT)、3β,16α-脱氢-5α-孕甾烷-20-酮(3β,16α-dihydroxy-5α-pregnan-20-one,DHP)、3β-羟基-5α-雄甾烷-17-酮(3β-hydroxy-5α-androstan-17-one,HA)对人乳腺癌细胞MCF-7的细胞增殖效应(Escreen实验);利用Luciferase报告基因与雌激素反应元件重组,与转染对照质粒pRL-cmv、雌激素受体ERα或ERβ质粒共同瞬时转染中国仓鼠卵巢细胞CHO,构建雌激素活性筛选模型,检测四种成分的雌激素活性。结果 E-screen实验结果显示,HP、PT、DHP、HA在1~50μmol·L-1内均能诱导MCF-7细胞增殖,显示出雌激素活性。与雌二醇(17α-estrodiol,E2)的增殖效应(proliferative effect,PE)、相对增殖效应(relative proliferative effect,RPE)和EC50相比,HP、PT、DHP、HA的雌激素活性均小于E2的雌激素活性。Luciferase报告基因实验结果显示,HP、PT、DHP、HA在1~50μmol·L-1内均能诱导Luciferase表达,显示雌激素活性。与E2的EC50值相比,HP、PT、DHP、HA的雌激素活性均弱于E2的雌激素活性。结论 HP、PT、DHP、HA均具有雌激素活性,与E2的雌激素活性相比,四种化合物均发挥弱雌激素效应。     

双环醇拮抗DDT引起的细胞间隙连接通讯功能抑制研究

目的研究治肝炎药物双环醇对促癌剂滴滴涕(DDT)引起细胞间隙连接通讯(GJIC)功能抑制的拮抗作用及作用机制。方法划痕标记染料示踪技术直接观察DDT引起的大鼠肝上皮WB-F344细胞GJIC功能抑制并分析双环醇的作用。利用Western blot方法检测间隙连接蛋白43(Cx43)、磷酸化Cx43、E-cadherin及β-Catenin的表达和活性。细胞免疫荧光技术考察WB-F344细胞Cx43蛋白亚细胞定位、间隙连接的形成及E-cadherin和β-Catenin在细胞内的表达。结果 DDT能剂量依赖性的抑制WB-F344细胞GJIC功能,20μM浓度时小分子荧光染料Luciferyellow CH仅能从伤沿细胞向后传递1-2列细胞。双环醇能部分恢复DDT引起的GJIC功能抑制,且具有一定剂量依赖关系,其作用机制与抑制DDT引起的磷酸化Cx43蛋白表达量升高,进而恢复DDT损伤的间隙连接形成有关。DDT和双环醇对与Cx43蛋白功能密切相关的E-cadherin及β-Catenin的表达、活性及细胞内定位均无明显影响。结论双环醇能通过影响Cx43蛋白的磷酸化水平,部分恢复环境促癌剂DDT引起的WB-F344细胞间隙连接的形成,改善GJIC功能。对GJIC的功能抑制是多种促癌剂诱发肿瘤发生的重要原因,前期研究显示双环醇具预防二甲基亚硝胺/苯巴比妥诱发肝癌发生的作用,本文研究结果进一步提示,双环醇在预防杀虫剂DDT(一种主要的环境致癌物)诱发的肿瘤方面亦具有一定潜能。     

吗啡对雌激素诱导的人正常乳腺细胞促增殖作用的影响

目的研究吗啡对雌激素诱导的体外培养的人正常乳腺细胞的促增殖作用的影响。方法培养人正常乳腺纤维细胞株,将培养好的细胞给予17-β雌二醇(E2)、吗啡及纳洛酮(特异性阿片受体拮抗剂)干预,分为4组:对照组(A组),E2组(B组),E2+吗啡组(C组),17-β雌二醇+吗啡+纳洛酮组(D组)。观察细胞的生长增殖情况并绘制生长曲线。结果第一代传代的乳腺细胞各组接种密度比较,差异无统计学意义(P>0.05)。接种用药第2、4、6、8天进行细胞计数,细胞数较对照组增加,C组细胞数较B组降低,差异有统计学意义(P<0.01)。D组与B组比较,差异无统计学意义(P>0.05)。结论吗啡可直接影响雌激素对乳腺的促增殖作用。     

利用哺乳动物细胞双杂交体系研究仙灵骨葆对雌激素受体的作用

目的:利用哺乳动物细胞双杂交体系研究仙灵骨葆对雌激素受体(ERs)活性的影响。方法:通过MTT法检测仙灵骨葆对Hela细胞活力的影响,并构建含有ERs配体结合域(LBD)的质粒pCMV-BD及含有报告基因Lusferase的质粒pFR-Luci,将二者与内标质粒pFRTlaczeo共转染到Hela细胞中,形成Gal4DBD-ERa和ERb LBD细胞杂交报告系统。以染料木苷为阳性对照验证本杂交系统,并利用本系统考察仙灵骨葆对ERs活性的影响。结果:仙灵骨葆在25～2 500 ng·mL-1浓度范围内可以促进HeLa细胞的增殖。10μmol．L-1染料木苷可以显著提高Gal4DBD-ERα和ERβLBD细胞杂交报告系统中ERa和ERb的活性,证明本系统构建成功。仙灵骨葆对ERa具有浓度依赖性的激活作用,2500 ng·mL-1浓度时ERa的相对荧光活性是DMSO对照组的18倍;仙灵骨葆对ERb也具有一定的激活作用,2500 ng·mL-1浓度时ERb的相对荧光活性是DMSO对照组的4倍。结论:本研究成功构建了含有雌激素受体配体结合域的细胞杂交系统,仙灵骨葆对该系统的ERs具有激活作用。     

Development of a rapid screening and surveillance for estrogenic chemicals in environment based on recombinant yEGFP yeast cell

A recombinant yEGFP gene yeast strain necessary for the routine screening of estrogen activity in the chemical product of the environment was described. Two plasmids, one containing human estrogen receptor (hER) cDNA fused to the GPD gene promoter and another yEGFP inserted under the control of ERE, were constructed. The use of hER cDNA and the yEGFP reporter in the yeast cell sensor resulted in estrogenic chemical product-dependent light emission of yEGFP without additions owing its advantages: a simple and reagent-free measurement of GFP, and a non-toxic protein characteristic. The time needed for the optimal induction of light emission was 4 h. The maximal fold induction of 8.80 over uninduced levels at the concentration of 10⁻⁵ M of bisphenol A and 0.1 nM sensitivities for four different estrogenic chemicals tested were obtained. Five different chemicals which could not bind to hER did not cause an induction of yEGFP. This bioassay can be performed completely in 96-well plates. Thus, this test system can be used as a rapid screening system for the surveillance of estrogenic chemical products in the environment. The yEGFP assay is sensitive, reproducible, and cheap, which makes it highly suitable to be used as a high throughput system.     

The in Vitro estrogenic activities of triclosan and triclocarban

Triclosan (TCS) and triclocarban (TCC), as broad spectrum antibacterial agents, are distributed widely in the environment and humans. Most studies have focused on their distribution and biodegradation, but the endocrine‐disrupting effects of these chemicals, especially their estrogenic effects, are still unclear. In the present study, we investigated the estrogenic effects of TCS and TCC using a series of in vitro assays, including the ER reporter gene assay in the CV‐1 cells, E‐screen assay and evaluation of estrogen‐responsive genes in the MCF‐7 cells. The tested concentrations of TCS and TCC were both from 1 × 10^–9 to 1 × 10^–6 M. Results showed that TCS and TCC exerted estrogenic activities by inducing luciferase activities in an ER reporter gene assay, promoting the proliferation of the MCF‐7 cells, up‐regulating the expression of pS2 and down‐regulating ERα expression at both the mRNA and protein levels in the MCF‐7 cells. We further found that TCS and TCC could alter the expression of multiple microRNAs (mir‐22, mir‐206 and mir‐193b) in the MCF‐7 cells, which would help understand the mechanisms of their estrogenic effects on regulating the expression of ERα. In brief, our results demonstrated the potential estrogenic effects and profiled in vitro data for further risk assessment of TCS and TCC. Copyright © 2014 John Wiley & Sons, Ltd.     

Screening of estrogenic and antiestrogenic activities from medicinal plants

The medicinal plant extracts commercially used in Asia were screened for their estrogenic and antiestrogenic activities in a recombinant yeast system featuring both a human estrogen receptor (ER) expression plasmid and a reporter plasmid. Pueraria lobata (flower) had the highest estrogenic relative potency (RP, 7.75×10(-3); RP of 17β-estradiol=1), followed by Amomum xanthioides (1.25×10(-3)). Next potent were a group consisting of Glycyrrhiza uralensis, Zingiber officinale, Rheum undulatum, Curcuma aromatica, Eriobotrya japonica, Sophora flavescens, Anemarrhena asphodeloides, Polygonum multiflorum, and Pueraria lobata (root) (ranging from 9.5×10(-4) to 1.0×10(-4)). Least potent were Prunus persica, Lycoppus lucidus, and Adenophora stricta (ranging from 9.0×10(-5) to 8.0×10(-5)). The extracts exerting antiestrogenic effects, Cinnamomum cassia and Prunus persica, had relative potencies of 1.14×10(-3) and 7.4×10(-4), respectively (RP of tamoxifen=1). The solvent fractions from selected estrogenic or antiestrogenic herbs had higher estrogenic relative potencies, with their RP ranging from 9.3×10(-1) to 2.7×10(-4) and from 8.2×10(-1) to 9.1×10(-3), respectively. These results support previous reports on the efficacy of Oriental medicinal plants used or not used as phytoestrogens for hormone replacement therapy.     

Effect of in vitro estrogenic pesticides on human oestrogen receptor alpha and beta mRNA levels

Nine widely distributed pesticides were recently demonstrated to possess potential estrogenic properties in oestrogen receptor (ER) transactivation and/or E-screen assays. We tested the effect of these nine pesticides on the human ERalpha and ERbeta mRNA steady state levels in the mamma cancer fibroblast MCF-7BUS cells using on-line RT-PCR. Like 17beta-oestradiol (E2), fenarimol significantly decreased the ERalpha and increased the ERbeta mRNA level. Endosulfan and pirimicarb alone decreased the ERalpha mRNA level weakly. After co-exposure with E2, all the tested pesticides counteracted the E2-induced decrease of the ERalpha mRNA level, but only significantly for prochloraz, dieldrin, and tolchlofos-methyl. Alone no pesticides affected the ERbeta mRNA level significantly, but chlorpyrifos increased the mRNA level weakly. Co-exposure with E2 elicited a significant increased ERbeta mRNA level by prochloraz, fenarimol, endosulfan, dieldrin, and tolchlofos-methyl, whereas no significant effect of the carbamate pesticides on the ERbeta mRNA level was observed. This study demonstrated that organochlor and organophosphorous pesticides possess the ability to interfere with the ERalpha and ERbeta mRNA steady state levels.     

Novel gene transfer vectors based on artificial recombinant multi-functional oligopeptides

Viral vectors, except for their safety concern, have shown high efficiency in both delivery and expression of gene. Here, a series of new gene carriers, comprised of short peptide subunits with special functions to imitate viral vectors, were designed and three vectors, (C(18))(2)KH(4)R(8)GDS, AcKH(4)R(8)GDS and (C(18))(2)KH(4)R(8), designated as ARM1, ARM2, ARM3, respectively, were synthesized and evaluated. The transfection efficiency in vitro was studied in terms of 293T, HepG2 and HeLa cell lines. It was found that the transfection efficiency was enhanced significantly for the vectors (ARM1 and ARM3) with double hydrophobic aliphatic tails. Interestingly, the conjugation of RGDS sequence in vectors displayed no obvious difference in cell adhesion for all of the three cell lines. Moreover, confocal laser scanning microscope results indicated that the peptide/pDNA complexes can enter the cell and nuclei successfully. On the other hand, all the vectors displayed low cytotoxicity. The artificial recombinant multi-block oligopeptides (ARMs) demonstrated here might give a promising potential of the peptide-based vectors in gene therapy.     

Effect of estrogenic binary mixtures in the yeast estrogen screen (YES)

Endocrine disrupting compounds (EDCs) of natural or synthetic origin can interfere with the balance of the hormonal system, either by altering hormone production, secretion, transport, or their binding and consequently lead to an adverse outcome in intact animals. An important aspect is the prediction of effects of combined exposure to two or more EDCs at the same time. The yeast estrogen assay (YES) is a broadly used method to assess estrogenic potential of chemicals. Besides exhibiting good predictivity to identify compounds which interfere with the estrogen receptor, it is easy to handle, rapid and therefore allows screening of a large number of single compounds and varying mixtures. Herein, we applied the YES assay to determine the potential combination effects of binary mixtures of two estrogenic compounds, bisphenol A and genistein, as well as one classical androgen that in vitro also exhibits estrogenic activity, trenbolone. In addition to generating data from combined exposure, we fitted these to a four-parametric logistic dose–response model. As all compounds tested share the same mode of action dose additivity was expected. To assess this, the Loewe model was utilized. Deviations between the Loewe additivity model and the observed responses were always small and global tests based on the whole dose–response data set indicated in general a good fit of the Loewe additivity model. At low concentrations concentration additivity was observed, while at high concentrations, the observed effect was lower than additivity, most likely reflecting receptor saturation. In conclusion, our results suggest that binary combinations of genistein, bisphenol A and trenbolone in the YES assay do not deviate from expected additivity.     

Assessment of polystyrene extract for estrogenic activity in the rat uterotrophic model and an in vitro recombinant receptor reporter gene assay

The purpose of the study was to determine whether polystyrene used in food-contact applications would elicit an estrogenic response when extracts simulating exaggerated conditions of use were subjected to in vivo and in vitro tests. A sample of polystyrene was subjected to extraction conditions that simulate, or exaggerate, the actual food-contact uses of polystyrene to maximize the amount of low molecular weight polystyrene extractables. The food-simulating solvent and the time and temperature conditions recommended by the Food and Drug Administration (FDA) were selected to maximize the level of extractable components from polystyrene. The extract was examined for its estrogenic response in vivo using the immature rat uterotrophic assay and in vitro using an estrogen receptor (ER)-mediated recombinant receptor reporter gene assay. In vivo, the uterine weights of juvenile female Sprague Dawley rats (10 rats/group) were determined after oral gavage exposure to the extract (two dosage levels: one represents the maximum potential daily human exposure to polystyrene extractables and the other represents one-tenth of the maximum exposure level), vehicle control (sesame oil), or positive control [diethylstilbestrol (DES), at 200 micrograms/kg body weight]. In addition, five treatment groups were dosed by subcutaneous injection of either estradiol (1, 50, and 500 micrograms/kg body weight) or DES (2 and 200 micrograms/kg body weight). Dosing began on postnatal day (pnd) 21 and continued daily through pnd 23. Body weights were collected at study initiation (pnd 21) and at necropsy (pnd 24). Body weights were not different statistically between treatment groups at study initiation or at necropsy. Uterine wet weights and uterine weights relative to body weights were significantly increased (p < 0.05) for estradiol at 50 and 500 micrograms/kg, DES at 2 and 200 micrograms/kg, and DES at 200 micrograms/kg (oral) over vehicle control. The polystyrene extract had no effect on uterine wet weight or uterine weights relative to body weights at either level tested. An in vitro recombinant estrogen receptor/reporter gene assay that involved transiently transfecting MCF-7 human breast cancer cells with the chimeric human ER, Ga14-HEGO, consisting of the yeast Ga14 DNA binding domain linked to the ligand binding domain of the human ER and a Ga14 response element (17mer)-regulated reporter gene (17m5-G-Luc) was employed. Dose-dependent induction of the reporter gene, 17m5-G-Luc, was observed with the positive control, 17 beta-estradiol (E2). Induction of greater than 100-fold was obtained following incubation of transfected MCF-7 cells with 10 nM E2 for 24 hours. No induction of reporter gene activity was observed with the polystyrene extracts dissolved in dimethylsulfoxide (0.01, 0.1 or 0.01 mg/ml) using the same assay conditions. These results indicate that polystyrene extract does not elicit ER-mediated activity using the Ga14-HEGO/17m5-G-Luc recombinant receptor/reporter gene assay. In conclusion, extracts from polystyrene produced no estrogenic response in either the rat uterotrophic assay or the MCF-7 cell assay for estrogen receptor-mediated activity.     

Weak estrogenic transcriptional activities of Bisphenol A and Bisphenol S

In 2011, the European Commission has restricted the use of Bisphenol A in plastic infant feeding bottles. In a response to this restriction, Bisphenol S is now often used as a component of plastic substitutes for the production of babybottles. One of the major concerns leading to the restriction of Bisphenol A was its weak estrogenic activity. By using two highly standardised transactivation assays, we could demonstrate that the estrogenic activity of Bisphenol A and Bisphenol S is of a comparable potency. Furthermore, some insights about the structure-activity relationships of these two chemicals and their metabolites could be gained from in silico predictions of their relative estrogen receptor-binding affinities and their liver phase-I biotransformation.