• 대한수의학회지
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• 제36권1호
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• pp.101-108
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• 1996

This study was desinged to investigate the effect of estrogen(Est) on the proliferating of progesterone(Prog) target cells. The spayed 13 rats(Wistar, approximately 300gm) were randomly alloted into 3 groups. One group was the control group and another Prog-treated group was injected with 1mg of Prog/rat/day for 2 consecutive days, and Estand Prog-treated group was injected intramuscularly with $17{\beta}$-estradiol $20{\mu}g/rat/day$ for 3 consecutive days and then with Prog for 2 days as above from 4th day. Rats were administrated intraperitoneally with bromodeoxyuridinc(Brdur,0.2mg/BW once) befero 2 hours of exanguination. In gross finding, the groups with more level of dimension and weight on the uterus were ordered as Est- and Prog-treated group, Prog-treated group and control group. The investigation by immunohistochemical methods using paraffin sections of the uteri was performed by using anti-Brdur antibody for labeling proliferating cells of Prog target cells. The groups with higher labeling index(LI) were ordered as Prog-treated grop, Est- and Prog- treated group and control group. The number of proliferating cells from Prog target cells in the rats were rather deceased by Prog injection following Est injection than prog injection only. The cell types with higher LI in the wall layers of all 3 groups were ordered as endometrial stromal cells, glandular epithelial cells, luminal epithelial cells, myometrial muscle cells and serosa methodelial cells, and the region with highest LI was functional zone of the endometrium and the region with lower LI was muscular layer and then those with lowest LI was serosa and also the considerable different LI from individual rat were observed.

• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.171-179
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• 2004

Cytochrome P4503A4(CYP3A4) is the most abundnat CYPs in human liver, comparising approximately 30% of the total liver CYPs contents ans is involbed in the metabolism of more than 60% of currently used therapeutic drugs. The expression of CYP3A4 is induced by a variety of structurally unrelated xonobiotics including the antibiotic rifampicin and endogenous hormones, and might be mediated through steroid and xenobiotic receptor(SXR) system. The molecular mechanisms underlying regulation of CYP3A4 gene expression hae not been understood. In order to gain the insight of the molecular mechanism of CYP3A4 gene expression, study has been undertaken to investigate if the histone deacelylation is involved in the regulation of CYP3A4 gene expression by proximal promoter or not. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. HepG2 or Hena-I cells were transfected with a plasmid containing~1kb of the CYP3A4 proximal promoter region (-863 to +64bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR or hER. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, or with estradiol, in order to exmine to regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In HepG2 cells, CYP3A4 inducers and estradiol increased significantly the luciferase activity by CYP3A4 proximal promoter, only when TSA was co-treated after SXR cotransfection. In the case of Hepa-I cells CYP3A4 inducers and estradiol incressed modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection in contrast to HepG2 cells. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Futher a trans-activation by SXR may demand other species-specific transcription factors.

• 한국발생생물학회지:발생과생식
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• 제22권4호
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• pp.309-318
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• 2018

The present study was conducted to investigate the regulatory mechanism of plasminogen activators (PAs) activation by $17{\beta}$-estradiol ($E_2$) and progesterone ($P_4$) in porcine uterine epithelial cells (pUECs). pUECs were collected from porcine uterine horn and cultured at 80% confluence. Then, 0.1% (v/v) DMSO, 20 ng/mL $E_2$, and $P_4$ with or without fetal bovine serum (FBS) treated to cultured cells for 24 hours. The supernatants were used for measurement of PAs activity and expression of urokinase-type PA (uPA), tissue-type PA (tPA), uPA specific receptor (uPAR), and type-1 PA inhibitor (PAI-1) mRNA were analyzed by real-time PCR. The expression of PAs-related genes was not affect by steroid hormones in both of serum treatment groups. However, PAs activity was increased by treatment of $E_2$ compared to 0.1% DMSO treatment in serum-free group (p<0.05). Then, $E_2$ and $P_4$ were diluted with 0.002% (v/v) DMSO for reduction of its effect and treated to cultured cells without FBS. Only tPA mRNA was significantly increased by $E_2$ treatment (p<0.05). PAs activity was enhanced in $E_2$ treated group compared to control groups (p<0.05). These results indicate that serum-free condition is more proper to evaluate effect of steroid hormones and activation of PAs in pUECs was mainly regulated by estrogen. These regulation of PAs activation may be associated with uterine remodeling during pre-ovulatory phase in pigs, however, further studies are needed to investigate precise regulatory mechanism.

• Clinical and Experimental Reproductive Medicine
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• 제48권3호
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• pp.245-254
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• 2021

Objective: In humans, polycystic ovary syndrome (PCOS) is an androgen-dependent ovarian disorder. Aberrant gene expression in folliculogenesis can arrest the transition of preantral to antral follicles, leading to PCOS. We explored the possible role of altered gene expression in preantral follicles of estradiol valerate (EV) induced polycystic ovaries (PCO) in a mouse model. Methods: Twenty female balb/c mice (8 weeks, 20.0±1.5 g) were grouped into control and PCO groups. PCO was induced by intramuscular EV injection. After 8 weeks, the animals were killed by cervical dislocation. Blood serum (for hormonal assessments using the enzyme-linked immunosorbent assay technique) was aspirated, and ovaries (the right ovary for histological examinations and the left for quantitative real-time polymerase) were dissected. Results: Compared to the control group, the PCO group showed significantly lower values for the mean body weight, number of preantral and antral follicles, serum levels of estradiol, luteinizing hormone, testosterone, and follicle-stimulating hormone, and gene expression of TGFB1, GDF9 and BMPR2 (p<0.05). Serum progesterone levels were significantly higher in the PCO animals than in the control group (p<0.05). No significant between-group differences (p>0.05) were found in BMP6 or BMP15 expression. Conclusion: In animals with EV-induced PCO, the preantral follicles did not develop into antral follicles. In this mouse model, the gene expression of TGFB1, GDF9, and BMPR2 was lower in preantral follicles, which is probably related to the pathologic conditions of PCO. Hypoandrogenism was also detected in this EV-induced murine PCO model.

• 생명과학회지
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• 제13권4호
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• pp.529-534
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• 2003

홍화씨가 골절, 골다공증 및 골형성부전증 등의 골 질환 치료에 효과가 있다는 것이 알려져 민간요법으로 사용되고 있으나 홍화씨의 어떤 성분이 이러한 작용을 하는지에 관해서는 거의 밝혀져 있지 않다. 본 연구에서는 흥화씨의 sterol 조성을 분석하고 폐경기 여성들의 골다공증 치료에 사용되고 있는 합성 estrogen 대체물질로써 그 기능이 확인된 phytoestrogen 활성을 측정하였다. Cholesterol에서 성호르몬인 estrogen이 합성되는 것처럼 식물 sterol 도 phytoestrogen 합성을 위한 전구체 작용을 하는 것으로 알려져 있다. 홍화씨에 존재하는 식물성 sterol은 stigmast-5-en-3-ol (3$\beta$, 24S)-form인 ${\gamma}$-sitosterol (clionasterol)로 확인되었으며 홍화에 존재하는 식물성 sterol의 함량은 총지질의 약 4%를 함유하였다. 홍화씨의 sterol 분석은 GC-MS와 Wiley MS spectrum library를 사용하여 분석하였으며 홍화씨에 존재하는 중요한 4-desmethyl sterols 에는 sitosterol 만이 확인되었다. 홍화씨의 식물성 estrogen 효과는 $\beta$-estradiol ($10^{-8}$ M)의 활성을 1로 했을 때 홍화씨의 에탄을 층(5 mg/ml) 및 메탄올 층(5 mg/ml)에서 각각 0.37과 0.43으로 estrogen 유사효과를 나타내었다(ANOVA p<0.001). 홍화씨에 포함된 estrogen에 의한 전사활성 촉진은 MCF7/pDS-CAT-ERE119-Ad2MLP system을 사용하여 estrogen수용체와 reporter gene 발현을 이용하는 방법으로 세포에 직접 처리함으로써 phytoestrogen 활성을 측정할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권3호
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• pp.340-350
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• 2007

The objective of this study was to determine whether peroxisome proliferator-activated receptor ${\gamma}$(PPAR${\gamma}$ is involved in the regulation of weaning to estrus of primiparous sows. Twelve sows composed of 6 groups of 2 full-sibs in a similar age (325.2 d), body weight (BW; 152.4 kg) and backfat thickness (BFT; 27.0 mm) at start of lactation, were allocated to accept 31 MJ (restricted group, R-group) or 53 MJ (control group, C-group) DE/d treatment, respectively. The experimental results indicated that the low energy intake resulted in excessive losses of BW and BFT during lactation in R-group sows, which may be related to decrease of serum 15-deoxy-${\Delta}^{12,14}$-prostaglandin $J_2$ (15d-$PGJ_2$), a ligand of PPAR${\gamma}$ The obvious peak and the frequency of LH, FSH and estradiol ($E_2$) were only observed in C-group sows. Except for $E_2$ at d 1 and 2, serum FSH, LH and $E_2$ concentrations in R-group were lower than those in C-group sows after weaning. However, the serum progesterone ($P_4$) level in R-group sows was always more than that in C-group. The expression abundances of PPAR${\gamma}$and GnRH receptor (GnRH-R) in pituitary, FSH receptor (FSH-R), LH receptor (LH-R), estrogen receptor (ES-R) and aromatase in ovary of anestrous sows were lower than those of estrous sows. Neither the BFT nor the BW was associated with the mRNA abundance of PPAR${\gamma}$in hypothalamus during lactation. Expressions of PPAR${\gamma}$in pituitary and ovary were affected evidently by the BFT changes and only by the loss of BW of sows during and after lactation. Furthermore, PPAR${\gamma}$mRNA level in ovary was significantly related to the expression abundances of GnRH-R, FSH-R, ES-R and aromatase, and GnRH-R was obviously associated with PPAR${\gamma}$expression in pituitary. However, PPAR${\gamma}$expression in hypothalamus likely has no effects on these genes expression and no obvious difference for all sows. Not serum $E_2$ or $P_4$ alone but the ratios of $E_2$ to $P_4$ and 15d-$PGJ_2$ to $P_4$, and serum FSH and LH were evidently related to PPAR${\gamma}$expression in pituitary and ovary. It is concluded that PPAR${\gamma}$is associated with body conditions, reproduction hormones and their receptor expression, which affected the functions of pituitary and ovary and ultimately the estrus after weaning of primiparous sows.

• Journal of Ginseng Research
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• 제43권4호
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• pp.527-538
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• 2019

Background: Ginsenoside Rg1 was shown to exert ligand-independent activation of estrogen receptor (ER) via mitogen-activated protein kinase-mediated pathway. Our study aimed to delineate the mechanisms by which Rg1 activates the rapid ER signaling pathways. Methods: ER-positive human breast cancer MCF-7 cells and ER-negative human embryonic kidney HEK293 cells were treated with Rg1 ($10^{-12}M$, $10^{-8}M$), $17{\beta}$-estradiol ($10^{-8}M$), or vehicle. Immunoprecipitation was conducted to investigate the interactions between signaling protein and ER in MCF-7 cells. To determine the roles of these signaling proteins in the actions of Rg1, small interfering RNA or their inhibitors were applied. Results: Rg1 rapidly induced $ER{\alpha}$ translocation to plasma membrane via caveolin-1 and the formation of signaling complex involving linker protein (Shc), insulin-like growth factor-I receptor, modulator of nongenomic activity of ER (MNAR), $ER{\alpha}$, and cellular nonreceptor tyrosine kinase (c-Src) in MCF-7 cells. The induction of extracellular signal-regulated protein kinase and mitogen-activated protein kinase kinase (MEK) phosphorylation in MCF-7 cells by Rg1 was suppressed by cotreatment with small interfering RNA against these signaling proteins. The stimulatory effects of Rg1 on MEK phosphorylation in these cells were suppressed by both PP2 (Src kinase inhibitor) and AG1478 [epidermal growth factor receptor (EGFR) inhibitor]. In addition, Rg1-induced estrogenic activities, EGFR and MEK phosphorylation in MCF-7 cells were abolished by cotreatment with G15 (G protein-coupled estrogen receptor-1 antagonist). The increase in intracellular cyclic AMP accumulation, but not Ca mobilization, in MCF-7 cells by Rg1 could be abolished by G15. Conclusion: Ginsenoside Rg1 exerted estrogenic actions by rapidly inducing the formation of ER containing signalosome in MCF-7 cells. Additionally, Rg1 could activate EGFR and c-Src ER-independently and exert estrogenic effects via rapid activation of membrane-associated ER and G protein-coupled estrogen receptor.

• Molecules and Cells
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• 제26권5호
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• pp.454-458
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• 2008

Sex steroid hormone receptors play a central role in modulating telomerase activity, especially in cancer cells. However, information on the regulation of steroid hormone receptors and their distinct functions on telomerase activity within the mesenchymal stem cell are largely unavailable due to low telomerase activity in the cell. In this study, the effects of estrogen ($E_2$) treatment and function of estrogen receptor alpha ($ER{\alpha}$) and estrogen receptor beta ($ER{\beta}$) on telomerase activity were investigated in human mesenchymal stem cells (hMSCs). Telomerase activity and mRNA expression of the catalytic subunit of telomerase (hTERT) were upregulated by treatment of the cells with $E_2$. The protein concentration of $ER{\alpha}$ was also increased by $E_2$ treatment, and enhancement of $ER{\alpha}$ accumulation in the nucleus was clearly detected with immunocytochemistry. When $ER{\alpha}$ expression was reduced by siRNA transfection into hMSCs, the effect of $E_2$ on the induction of hTERT expression and telomerase activity was diminished. In contrast, the transient overexpression of $ER{\alpha}$ increased the effect of $E_2$ on the expression of hTERT mRNA. These findings indicate that the activation of hTERT expression and telomerase activity by $E_2$ in hMSCs depends on $ER{\alpha}$, but not on $ER{\beta}$.

• The Korean Journal of Physiology and Pharmacology
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• 제6권3호
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• pp.165-169
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• 2002

We have previously demonstrated that phytoestrogens isolated from safflower seeds significantly attenuated bone loss in ovariectomized rats, and directly stimulated proliferation and differentiation of cultured osteoblastic cells. In an attempt to elucidate underlying cellular mechanisms, in the present study we investigated effects of $17{\beta}-estradiol\;(E_2)$ and phytoestrogens such as matairesinol and acacetin, a type of lignan and flavonoid, respectively, on activation of mitogen activated protein (MAP) kinases, extracellular signal-regulated kinase 1 (ERK1) and ERK2, in cultured osteoblastic ROS 17/2.8 cells. Western blot analysis with anti-MAP kinase antibody showed that a wide range concentrations $(10^{-14}\;to\;10^{-6}\;M)\;of\;E_2$ as well as both phytoestrogens induced rapid and transient activation of ERK1/2 through phosphorylation within minutes. Maximum activation of MAP kinases by $E_2$ and phytoestrogens were observed at 10 and 15 min, respectively. $E_2-induced$ phosphorylation of ERK1/2 returned to the control level at 30 min, whereas phytoestrogen-induced phosphorylation was maintained at high level until 30 min. PD-98059, a highly selective inhibitor of MAP kinase, prevented phosphorylation of ERK1/2 in the cells treated either with $E_2$ or phytoestrogens. To examine a possible involvement of estrogen receptor in the activation process of MAP kinase, Western blot analysis was performed in the presence and absence of the estrogen receptor antagonists, ICI 182,780 and tamoxifen. These antagonists blocked MAP kinase phosphorylation induced not only by $E_2,$ but also by the phytoestrogens. To the best our knowledge, this study is the first to demonstrate that phytoestrogens such as flavonoid and lignan extracted from safflower seeds produce a rapid activation of MAP kinase, at least partially via membrane estrogen receptor of the cultured osteoblastic cells.

• Toxicological Research
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• 제20권3호
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• pp.205-211
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• 2004

Concern that some chemicals in our environment may affect human health by disrupt-ing normal endocrine function has prompted a research on interactions of environmental contaminants with steroid hormone receptor. Toxaphene and chlordane are among the 12 persistent organic pollutants identified by the United Nations Environment Programme as requiring urgent attention. We compared the estrogenic activity of two organochlorine pesticides, toxaphene and chlordane, at estrogen receptor a (ER$\alpha$) and estrogen receptor $\beta$ (ER$\beta$). Human hepatoma cells (HepG2) were transiently transfected with rat ER$\alpha$ or ER$\beta$ plus an estrogen-responsive complement C3-luciferase (C3-Luc) reporter gene. After transfection, cells were treated with various concentrations of toxaphene and chlordane to investigate agonism or antagonism of these chemicals. Both toxaphene and chlordane were potent agonists in HepG2 cells for ER$\alpha$. In contrast, these chemicals had a minimal agonist activity with ER$\beta$ and almost abolished 17$\beta$-estradiol-induced ER$\beta$-mediated activity. Therefore, toxaphene and chlordane behaved as an ER$\alpha$ agonist and an ER$\beta$ antagonist with estrogen-responsive reporter plasmid C3-Luc, and exposure to these organochlorine pesticides could have a crictical effect on normal endocrine function.