• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.280-286
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• 2001

Epigallocathechin-3-gallate (EGCG), the main polyphenol component in green tea, inhibits angiogenesis, urokinase, and matalloproteinases, and EGCG also has the antioxidative property. Recent reports proposed that EGCG may modulate the immune response on allergy or asthma. Human nasal mucosal fibroblasts are a rich source of cytokines, inflammatory mediators, and chemokines. Chemokines are important for the recruitment of leukocytes to sites of infection, which is essential in host defense. The objective of this study was to investigate the effect of EGCG on the expression of the chemokines such as RANTES (regulated upon activation, normal T cell expressed and presumably secreted), eotaxin, and interleukin-8 (IL-8) in human nasal mucosal fibroblasts after stimulation with cytokines like IL-4, tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$, and $interferon-{\gamma}\;(IFN-{\gamma})$. To detect the expression of chemokine genes, RT-PCR was performed. Expressions of RANTES, eotaxin, and IL-8 mRNA stimulated with IL-4 and $TNF-{\alpha}$ were increased, respectively, while the expression of those genes incubated with $IFN-{\gamma}$ was similar pattern compared to control group. Analyses of chemokine genes of cells pretreated with EGCG showed that the expressions of eotaxin, and IL-8 genes stimulated $IFN-{\gamma}$ were higher compared with those not pretreated with EGCG.

• YAKHAK HOEJI
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• v.50 no.2
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• pp.124-128
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• 2006

Astrocyte has emerged as an active regulator of brain function, which connects between blood vessels and neurons as well as is a structural component of the blood-brain barrier, From its structural characteristics, astrocyte seems to sensitively respond to oxygen tension, and, in turn, generate diverse cellular cascades. Therefore, to reveal astrocytlc events by oxygen change, we screened genes whose expressions are upregulated under reoxygenation after hypoxic stress using cDNA representational difference analysis (RDA) technique. Meteorin that regulates glial differentiation was isolated from primary cultured rat astrocytes as a hypoxia/reoxygenation regulatory factor. We cloned rat version of Meteorin (rMe-teorin) and determined full-size sequences of rMeteorin. In addition, RT-PCR analysis revealed that Meteorin was increased under reoxygenation in astrocytes and highly expressed in the developing brain. Collectively, these results suggest that Meteorin may regulate astrocyte-mediated effects in response to the change of oxygen tension in the pathophysiological states.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.114-114
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• 2003

Ginseng is a medicinal herb widely used in Asian countries, and its pharmacological effects has been demonstrated in various systems such as cardiovascular, central nervous, and endocrine systems. Its effects are mainly attributed to the ginsenosides. We hypothesize that a component of Panax ginseng, ginsenoside-Rbl, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rbl in a transient transfection system using estrogen receptors ${\alpha}$ or ${\beta}$ with estrogen -responsive luciferase plasmids in COS monkey kidney cells. Ginsenoside-Rbl activated both estrogen receptors ${\alpha}$ and ${\beta}$ in a dose-dependent manner (0.5 -100 M ). Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rbl is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rbl to induce estrogen-responsive progesterone receptor gene by semi-quantitative RT-PCR assays. MCF-7 cells treated with l7${\beta}$-estradiol or ginsenoside- Rb1 exhibited an increased expression of progesterone receptor mRNA. However, ginsenoside-Rbl failed to displace the specific binding of ［3H］17${\beta}$-estradiol to estrogen receptor in MCF-7 cells as examined by whole cell ligand binding assays, suggesting that there is no direct interaction of ginsenoside-Rbl with estrogen receptor. Our results indicate that estrogen-like activity of ginsenoside-Rbl is independent of direct estrogen receptor association.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.57-63
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• 2001

Barley Yellow Dwarf Virus (BYDV) has been a major disease causing a severe loss of yield in winter cereals worldwide. It has been recently reported that BYDV occurs frequently in wheat field and also causes serious yield reduction in Korea. This study was performed to investigate the regional distributions of BYDV strains in Korea and to identify the resistant cultivars or lines of wheat to the predominant BYDV strains, providing basic information for the breeding of BYDV-resistant wheat varieties. Using RT-PCR and EcoRI digestion methods, the regional distribution of BYDV strains in Korea from 1999 to 2000 showed that PAV strain was mainly detected about 65% (Vic-PAV 52.6% ; CN-PAV 47.4%) and MAV strain about 3%. Using ELISA test for the examination of BYDV resistance with 17 cultivars and 4 lines among Korean wheat, three cultivars, Gurumil, Topdongmil, and Olgurumil, were susceptible to BYDV and the others were resistant. In plant growth and yield component responses to BYDV infection, Gurumil showed significant difference between the uninfected and the infected, suggesting the most susceptible to BYDV among Korean wheat, but Eun-pamil and Seohae118 did no difference, an indication that they have the highest resistance.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.143.1-143.1
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• 2012

We attempt to investigate the main reason of the asymmetrical light curves of contact and near-contact eclipsing binary base on the hypothesis that cool spot was produced on late type star while hot spot was produced from transferred material from their companion star hitting surface. We select 7 eclipsing binary systems which showed asymmetric light curves and mass transfer. Period variation and mass transfer rate were obtained from O-C diagram. Radial velocity curves and light curves of those 7 eclipsing binary system were adopted from available literature in order to obtain the absolute dimension. For four contact eclipsing binary system (AD Phe, EZ Hya, AG Vir and VW Boo), their component stars belonged to spectral type G to K was fitted by cool spot model. While the other two near-contact systems (RT Scl and V1010 Oph) and one contact system (SV Cen) was fitted by cool spot model. The densities of the materials are adopted from stellar model which calculate by stellar structure code. The calculated spot temperature turns out to agree with the photometric solution but there are no correlate between period variation rate and type of spot.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.355-360
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• 2005

Sulfur, an important component of plants, is regulated by a variety of stresses in sulfate assimilation and metabolism. Increase has been observed in the expression of O-acetylserine(thiol)lyase (OASTL) through two-dimensional electrophoresis with the shoot tips of Arabidopsis infected by beet severe curly top geminivirus (BSCTV). With the three- to six-fold increases in the transcript expression of OASTL, serine acetyltransferase (SAT) and $\gamma$-glutmylcysteine synthetase (GSH) were induced over the mock-inoculated organization in each organization through real-time RT-PCR analysis. The expression of those genes might affect the accumulation of anthocyanin in symptomatic tissues and the induction of abnormal callus-like structures formed by additional cell divisions as typical disease symptoms of BSCTV-infected Arabidopsis. This is the first report to describe the collaborative induction of OASTL, SAT, and GSH in virus-infected plants. The changed expressions of OASTL, SAT, and GSH in Arabidopsis infected with BSCTV raises new aspects regarding the biological function of symptomatic tissues related to sulfate metabolism.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.424-430
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• 2006

Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.4
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• pp.379-387
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• 2024

Breast cancer (BC) is most commonly diagnosed worldwide. Liquiritigenin is a flavonoid found in various species of the Glycyrrhiza genus, showing anti-tumor activity. This article was to explore the influences of liquiritigenin on the biological behaviors of BC cells and its underlying mechanism. BC cells were treated with liquiritigenin alone or transfected with oe-HSP90 before liquiritigenin treatment. RT-qPCR and Western blotting were employed to examine the levels of HSP90, Snail, E-cadherin, HSC70, and LAMP-2A. Cell viability, proliferation, migration, and invasion were evaluated by performing MTT, colony formation, scratch, and Transwell assays, respectively. Liquiritigenin treatment reduced HSP90 and Snail levels and enhanced E-cadherin expression as well as inhibiting the proliferation, migration, and invasion of BC cells. Moreover, liquiritigenin treatment decreased the expression of HSC70 and LAMP-2A, proteins related to chaperone-mediated autophagy (CMA). HSP90 overexpression promoted the CMA, invasion, and migration of BC cells under liquiritigenin treatment. Liquiritigenin inhibits HSP90-mediated CMA, thereby suppressing BC cell growth.

• Childhood Kidney Diseases
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• v.15 no.2
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• pp.138-145
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• 2011

Purpose : To test whether the expression of ${\beta}$-catenin, a component of podocyte as a filtration molecule, would be altered by puromycin aminonucleoside (PAN) in the cultured podocyte in vitro. Methods : We cultured rat glomerular epithelial cells (GEpC) with various concentrations of PAN and examined the distribution of ${\beta}$-catenin by confocal microscope and measured the change of ${\beta}$-catenin expression by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Results :We found that ${\beta}$-catenin relocalized from peripheral cytoplasm to inner cytoplasm, therefore, intercellular separations were seen in confluently cultured cells by high concentrations of PAN in immunofluorescence views. In Western blotting of GEpC, PAN ($50{\mu}g/mL$) decreased ${\beta}$-catenin expression by 34.9% at 24 hrs and 34.3% at 48 hrs, compared to those in without PAN condition (P<0.05). In RT-PCR, high concentrations ($50{\mu}g/mL$) of PAN also decreased ${\beta}$-catenin mRNA expression similar to protein suppression by 25.4% at 24 hrs and 51.8% at 48 hrs (P<0.05). Conclusion : Exposure of podocytes to PAN in vitro relocates ${\beta}$-catenin internally and reduces ${\beta}$-catenin mRNA and protein expression, which could explain the development of proteinuria in experimental PAN-induced nephropathy.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.301-308
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• 2013

Programmed Death-1 (PD-1) is one of the important immune-inhibitory molecules which was expressed in T cells, B cells, NKT cells, and macrophages activated by various immune activating factors. Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is one of the crucial immunogens for PD-1 expression. However, there are only a few reports on the expression mechanisms of PD-1 in innate immune cells. In this study, we investigate the expression mechanisms of PD-1 in LPS-stimulated Raw264.7 cell lines by RT-PCR, Western Blot, flow cytometry as well as ChIP assay and co-immunoprecipitation. When Raw264.7 cells were stimulated with LPS, PD-1 expression was greatly up-regulated via PI3K and p38 signaling. Primary macrophages isolated from LPS-injected mice were also shown the increased expression of PD-1. In promoter assay, NF-${\kappa}B$ and IRF-1 binding regions in mouse PD-1 promoter are important for PD-1 expression. We also found that the co-activation of NF-${\kappa}B$ and IRF-1 is indispensable for the maximum PD-1 expression. These results indicate that the modulation of PD-1 expressed in innate immune cells could be a crucial for the disease therapy such as LPS-induced mouse sepsis model.