• 한국동물학회지
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• 제33권4호
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• pp.435-445
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• 1990

시상하부에서 합성, 분비되는 gonadotropin releasing horrnone (GnRH)의 면역반응성이 생식소를 비롯한 여러 부위에서도 검출됨이 알려졌으나, 이 펩타이트가 과연 생식소에서 국부적으로 합성되는 지에 관해서는 아직 밝혀지지 않았다. 본 연구에서는 흰쥐 생식소에서 GnRH유전자발현을 연구하기 위하여 GnRH-like mRNA와 GnRH펩타이트의 발현과 세포내 분포 양상을 조사하였다. GnRH 방사면역측정법과 GnRH를 크로마토그라피 방법으로 분리한 결과,시상하부에서 합성되는 GnRH와 유사한 GnRH 면역반은이 흰쥐 생식소 추출물에서 상당량 검출되었다. GnRH-면역반응이 흰쥐 난소의 다양한 세포군에서 나타냄에 반하여, GnRH-like mRNA는 granulsa,theca 그리고 luteal 세포에서만 주로 발현되었다. 또한 흰쥐 정소에서 GnRH면역반응성은 원시정세포, Sertoli,Leydig 세포에서만 검출된 반면에, GnRH-like mRNA는 정세관내의 Seertoli세포에서만 발현되었다. 따라서 이 연구는 생식소에 존재하는 GnRH는 생식소 내에서 국부적으로 합성, 발현되는 결과라고 사료되며, 생식소 내에서 생성된 GnRH는 생식소내 세포군간의 정보교환의 매개자로서 역활을 수행하고 있다고 추정된다.

• BMB Reports
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• 제43권7호
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• pp.461-467
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• 2010

Natural products with non-toxic and environmentally friendly properties are good resources for skin-whitening cosmetic agents when compared to artificial synthetic chemicals. Here, we investigated the effect of glyceollin produced to induce disease resistance responses of soybean to specific races of an incompatible pathogen, phytophthora sojae, on melanogenesis and discussed their mechanisms in melanin biosynthesis. We found that glyceollin inhibits melanin synthesis and tyrosinase activity in B16 melanoma cells without cytotoxicity. To elucidate the mechanism of the effect of glyceollin on melanogenesis, we conducted western blot analysis for melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2. Glyceollin inhibited tyrosinase and TRP-1 protein expression. Additionally, glyceollin effectively inhibited intracellular cAMP levels in B16 melanoma cells stimulated by $\alpha$-melanocyte stimulating hormone ($\alpha$-MSH). These results suggest that the whitening activity of glyceollin may be due to the inhibition of cAMP involved in the signal pathway of $\alpha$-MSH in B16 melanoma cells.

• KSBB Journal
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• 제14권6호
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• pp.682-687
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• 1999

Streptomyces virginiae 유래의 virginiamycin 생합성 유도인자인 VB-C를 이용하여 다른 방선균에의 항생물질 생산 유도 기능을 검토하였다. Erythromycin 생산균인 Streptomyces erythraeus를 공시균주로 사용하였으며, VB-C 결합 receptor 유전자가 포함된 plasmid(pARS 701, 9 kb)를 공시균주에 도입하여 transformant로 사용하였다. Parent와 transformant 모두 유도인자인 VB류를 생산하였으며, VB-C의 signal 전달에 관여하는 결합 단백질의 존재가 확인되었다. Parent는 본배양 0, 20, 44시간째에 합성 VB-C 300 ng/ml를 첨가시 초기 항생물질 생산시기가 약 8시간 이상 단축되었다. Transformant는 본배양 44시간에 첨가시 6시간 이상 항생물질 생산시기가 단축되었고 항생물질 생산량도 증가되었으며, parent에 비해 B. subtilis에도 강한 항균력을 나타내었다. 또한 항균 spectrum은 parent보다는 transformant가 생산한 항생물질의 항균호과가 더 큰 것으로 나타났으며, VB-C를 첨가한 경우 미첨가 경우보다 넓은 항균 spectrum을 보였다. 이들 결과에서 공시균인 S. erythraeus에서 VB signal 전달에 따른 항생물질 생산유도가 입증되었으며, VB-C receptor gene의 도입에 따른 발현과 함께 VBs의 유도, 항생물질의 생산시기의 단축 및 생산량의 증가가 예상됨에 따라 다양한 Streptomyces sp. 균주를 대상으로 항생물질의 대량생산을 비롯한 새로운 2차 대사산물 생산에의 응용이 예상되었다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.112-112
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• 2001

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.

• 동의생리병리학회지
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• 제19권3호
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• pp.662-670
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• 2005

Recently many efforts were focused to understand the mechanical insights of melanogenesis to develop the agents for hyper-pigmentation and hypo-pigmentation. In the melanin bio-synthetic pathway, tyrosinase is the rate limiting enzyme, and ${\alpha}$-melanocyte stimulating hormone(MSH) stimulates melanogenesis and enhances the melanin synthesis and the tyrosinase activity. The author has analyzed the effects of Biota Orientalis Folium on the basal melanogenic activities of B16 mouse melanoma cells, and on the ${\alpha}$-MSH or tyrosinase-induced melanogenesis. Biota Orientalis Folium alone markedly suppressed melanin content and tyrosinase activity in a dose-dependent manner. The decrease of cell propagation was observed in B16 cells treated with 200${\mu}$g/ml dose of Biota Orientalis Folium, indicating that Biota Orientalis Folium-induced depigmenting effect was caused by inhibition of melanin synthesis, not due to destruction of B16 cells. Pretreatment of the cells with Biota Orientalis Folium also suppressed the increase of ${\alpha}$-MSH (10 nM) induced melanin content and tyrosinase activity. Biota Orientalis Folium inhibited the revelation of ${\alpha}$-MSH induced tyrosinase protein and tyrosinase related protein and mRNA of tyrosinase in B16 melanoma cell. These results suggest that Biota Orientalis Folium inhibits melanogenesis and abrogates ${\alpha}$-MSH and tyrosinase-induced melanogenesis in B16 melanoma cells.

• 분석과학
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• 제12권4호
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• pp.265-272
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• 1999

에스트로겐처럼 행동하여 호르몬 수용체와 결합하거나 세포의 신호전달 과정에 영향을 미침으로서 내분비계를 교란시킬 수 있는 환경 에스트로겐 19종 (phytoestrogen: 12종, mycoestrogen: 5종, synthetic estrogen: 2종)의 동시 프로필 분석을 시도하였다. Gas Chromatography/Mass Spectrometry (GC/MS)의 selected ion monitoring (SIM) 방법을 기본으로 하였으며, 액체-고체 추출, 효소 기수분해, 액체-액체 추출 그리고 trimethylsilyl (TMS)-ether 형태의 유도체화를 거치는 비교적 간편한 전처리 방법으로 47.6~99.5%의 회수율과 0.66~9.33%, 1.66~16.14%의 within-a-day 및 day-to-day 분석의 RSD 값을 얻었다. 이 방법을 적용하여 정상 성인 여성과 남성의 뇨 시료에 존재하는 대상 물질들의 농도범위를 결정함으로서 환경 에스트로겐의 영향을 평가하는데 기준이 될 수 있는 한국인 정상인 참고치를 설정하였다.

• Journal of Ginseng Research
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• 제36권4호
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• pp.449-460
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• 2012

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.

• Journal of Ginseng Research
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• 제32권2호
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• pp.99-106
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• 2008

A ligand - whether an endogenous hormone, neurotransmitter, exogenous toxin or synthetic drug - binds to plasma membrane proteins (e.g., ion channels, receptors or other functional proteins) to exert its physiological or pharmacological effects. Ligands can also have functional groups, showing stereospecificity for interaction sites on their counterpart plasma membrane proteins. Previous reports have shown that the ginsenoside Rg$_3$, a bioactive ginsenoside, meets these criteria in that: 1) an aliphatic side chain of $Rg_3$ plays a role as a functional group, 2) Rg$_3$ regulates voltage- and ligand-gated ion channels in a stereospecific manner with respect to carbon-20, and 3) $Rg_3$ regulates subsets of ligand-gated and voltage-gated ion channels through specific interactions with identified amino acid residues inside the channel pore, in the outer pore entryway, or in toxin binding sites. Rg$_3$, therefore, could be a candidate for a novel ginseng-derived glycosidic ligand regulating ion channels and receptors. This review will examine how Rg$_3$ regulates voltage-gated and ligand-gated ion channels through interactions with its target proteins in the plasma membrane. Hopefully, this review will advance understanding of ginseng pharmacology at the cellular and molecular levels.

• 약학회지
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• 제50권6호
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• pp.386-392
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• 2006

Pramlintide, a synthetic analogue of human hormone amylin, is the first of a new class of amylinomimetic compounds. Present study was undertaken to compile and analyze the clinical trials of pramlintide, and thereby to facilitate the design of the bridging study for the earlier introduction of the drug, which might be needed by diabetes patients in Korea. Sixty-two articles from Pubmed and MEDLINE search were used to analyze the trials of pramlintide along with prescribing information and New Drug Application packet obtained form the manufacturer. The efficacy of the new drug was attributed to three mechanisms: delay of gastric emptying time, inhibition of post-prandial glucagon secretion, and reduction of food intake by enhanced satiety. Clinical trials consistently identified the effectiveness of the drug for the treatment of type 1and type 2 diabetes who have failed to achieve glycemic control despite optimal therapy with insulin. However, the six pivotal Phase III clinical trials were peformed with mostly caucasian and some black and hispanic people. None of the trials documented the proportion of either Asian or Korean participants. Since Korean diabetes patients show different epidemiology and characteristics in their disease state, it appears that the bridging study of pramlintide should be designed in the level of full scale Phase III clinical trial along with pharmacokinetic and pbarmacodynamic studies.

• BMB Reports
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• 제52권11호
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• pp.647-652
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• 2019

G protein-coupled estrogen receptor (GPER) is known to play an important role in hormone-associated cancers. G-1, a novel synthetic GPER agonist, has been reported to exhibit anti-carcinogenic properties. However, the chemotherapeutic mechanism of GPER is yet unclear. Here, we evaluated GPER expression in human gastric cancer tissues and cells. We found that G-1 treatment attenuates GPER expression in gastric cancer. GPER expression increased G-1-induced antitumor effects in mouse xenograft model. We analyzed the effects of knockdown/overexpression of GPER on G-1-induced cell death in cancer cells. Increased GPER expression in human gastric cancer cells increased G-1-induced cell death via increased levels of cleaved caspase-3, -9, and cleaved poly ADP-ribose polymerase. Interestingly, during G-1-induced cell death, GPER mRNA and protein expression was attenuated and associated with ER stress-induced expression of PERK, ATF-4, GRP-78, and CHOP. Furthermore, PERK-dependent induction of ER stress activation increased G-1-induced cell death, whereas PERK silencing decreased cell death and increased drug sensitivity. Taken together, the data suggest that the induction of ER stress via GPER expression may increase G-1-induced cell death in gastric cancer cells. These results may contribute to a new paradigm shift in gastric cancer therapy.