• 제목/요약/키워드: E$_2$-ER binding affinity

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무지개송어, Oncorhynchus mykiss 배양 간세포에서 2,4-Dichlorophenoxy acetic acid이 Vitellogenin 합성과 $E_2$-ER Binding Affinity에 미치는 영향 (Effect of 2,4-Dichlorophenoxy Acetic Acid on Vitellogenin Synthesis and $E_2$-ER Binding Affinity of Hepatocytes in Rainbow Trout (Oncorhynchus mykiss))

  • 황운기
    • 한국양식학회지
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    • 제15권1호
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    • pp.31-37
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    • 2002
  • 이 연구는 무지개송어, O. mykiss 간세포 배양을 이용해 합성화학물질인 2,4-Dichlorophenoxy acetic acid (2,4-D)가 vitellogenin (VTG) 합성과 estrogen (E$_2$) - estrogen receptor (ER) binding affinity에 미치는 영향을 조사하였다. 간세포는 2일간 전 배양한 후에 E, (2$\times$10$\^$-6/ M) 또는 2,4-D (10$\^$-9/∼10$\^$-6/ M)를 배지에 첨가해 5일간 배양한 후, VTG과 E$_2$-ER binding affinity를 SDS-PAGE와 ELISA를 이용해 각각 조사하였다. 사용된 2,4-D의 농도는 세포의 형태, 생존력 및 DNA 함량에는 영향을 미치지 않았다. 또한, 2,4-D는 VTG의 합성에도 어떠한 영향도 미치지 않았으나 E$_2$-ER binding affinity를 억제하였다. 이 binding affinity는 2,4-D의 농도가 증가할수록 증가하는 경향을 나타내어 10$\^$-7/과 10$\^$-6/ M에서 25%와 30%를 각각 억제하였다. 이 결과들은 비록 2,4-D가 VTG의 합성에는 영향을 미치지 않지만, ER에서 xeno-estrogenic contaminant로서 행동하는 것을 제시하였다.

Sequence to Structure Approach of Estrogen Receptor Alpha and Ligand Interactions

  • Chamkasem, Aekkapot;Toniti, Waraphan
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권6호
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    • pp.2161-2166
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    • 2015
  • Estrogen receptors (ERs) are steroid receptors located in the cytoplasm and on the nuclear membrane. The sequence similarities of human $ER{\alpha}$, mouse $ER{\alpha}$, rat $ER{\alpha}$, dog $ER{\alpha}$, and cat $ER{\alpha}$ are above 90%, but structures of $ER{\alpha}$ may different among species. Estrogen can be agonist and antagonist depending on its target organs. This hormone play roles in several diseases including breast cancer. There are variety of the relative binding affinity (RBA) of ER and estrogen species in comparison to $17{\beta}-estradiol$ (E2), which is a natural ligand of both $ER{\alpha}$ and $ER{\beta}$. The RBA of the estrogen species are as following: diethyl stilbestrol (DES) > hexestrol > dienestrol > $17{\beta}-estradiol$ (E2) > 17- estradiol > moxestrol > estriol (E3) >4-OH estradiol > estrone-3-sulfate. Estrogen mimetic drugs, selective estrogen receptor modulators (SERMs), have been used as hormonal therapy for ER positive breast cancer and postmenopausal osteoporosis. In the postgenomic era, in silico models have become effective tools for modern drug discovery. These provide three dimensional structures of many transmembrane receptors and enzymes, which are important targets of de novo drug development. The estimated inhibition constants (Ki) from computational model have been used as a screening procedure before in vitro and in vivo studies.

Evaluation of Estrogenic Effects of Phthalate Analogues Using in vitro and in vivo Screening Assays

  • Kim, Youn-Jung;Ryu, Jae-Chun
    • Molecular & Cellular Toxicology
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    • 제2권2호
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    • pp.106-113
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    • 2006
  • Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were classified in the category of "suspected" endocrine disruptors. The purpose of our study was to screen and elucidate the endocrine disrupting activity of seven phthalate analogues. E-screen assay was performed in MCF-7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) showed high estrogenic activity. Their relative proliferation efficiencies (RPE) were 109 and 106%, respectively. In vitro estrogen receptor (ER) binding assay, BBP, di-n-octyl phthalate (DOP) and dinonyl phthalate (DNP) showed weak relative binding affinity (RBA: 0.02%) compared to $17{\beta}-estradiol\;(E2)$ (RBA: 100%). In uterotrophic assay, E2 produced a significant increase, whereas four tested phthalate analogues had potential estrogenic effects in vitro did not increased in uterus weight in immature rats. From these results, we demonstrated that phthalate analogues exhibit weak estrogenic activity in vitro assays at high concentrations. Although phthalates induced an increase in MCF-7 cell proliferation by an estrogenic effect, they could not induce a uterus weight increase in vivo. From these, we may suggest that these phthalate analogues are easily metabolized to inactive forms in vivo. Further investigation in other in vitro and in vivo experimental systems might be required.

Effects of Panax ginseng, zearalenol, and estradiol on sperm function

  • Gray, Sandra L.;Lackey, Brett R.;Boone, William R.
    • Journal of Ginseng Research
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    • 제40권3호
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    • pp.251-259
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    • 2016
  • Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.