• The Korea Journal of Herbology
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• v.26 no.1
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• pp.65-74
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• 2011

Objectives : This study was undertaken to verify the modulation mechanism of Gyeongshingangjeehwan18 (GGEx18) in ob/ob male mice. Methods : Eight-week old mice (wild-type C57BL/6J and ob/ob) were used for all experiments. Wild-type C57BL/6J mice were used as lean control and obese ob/ob mice were randomly divided into 5 groups : obese control, GGEx15 (Ephedra sinica Stapf + Rheum palmatum L.), GGEx16 (Ephedra sinica Stapf + Laminaria japonica Aresch), GGEx17 (Rheum palmatum L. + Laminaria japonica Aresch), and GGEx18 (Ephedra sinica Stapf + Laminaria japonica Aresch + Rheum palmatum L.). After mice were treated with several kinds of GGEx for 11 weeks, the mRNA expression of peroxisome proliferator-activated receptor (PPAR) target genes and uncoupling protein (UCP) were measured. In addition, $PPAR{\alpha}$ and $PPAR{\beta}$ transactivation was examined in NMu2Li hepatocytes, C2C12 myocytes, and 3T3-L1 preadipocytes using transient transfection assays. Results : 1. Hepatic $PPAR{\alpha}$ target genes, such as ACOX and VLCAD mRNA levels were significantly increased by GGEx18 compared with obese controls. In skeletal muscle, LCAD mRNA expression was stimulated by GGEx16, GGEx17, and GGEx18, whereas MCAD mRNA expression by GGEx17 and GGEx18. $PPAR{\beta}$ target LPL mRNA levels were also increased by GGEx16, GGEx17, and GGEx18 in skeletal muscle, but adipose LPL mRNA levels were decreased. In addition, GGEx18 upregulated UCP mRNA expression in skeletal muslce. 2. $PPAR{\alpha}$ reporter gene expression was increased by GGEx18 in NMu2Li cells compared with vehicle. $PPAR{\alpha}$ and $PPAR{\beta}$ reporter activities were also increased by all GGEx treatments in C2C12 and 3T3-L1 cells. Conclusions : These results suggest that GGEx can act as $PPAR{\alpha}$ and $PPAR{\beta}$ activators, and that GGEx may regulate obesity by stimulating $PPAR{\alpha}$, $PPAR{\beta}$, and UCP activity. Of the 4 compositions, GGEx18 seems to be most effective in improving obesity and lipid disorders.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.267-273
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• 2003

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.337-344
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• 2002

Runx2, a Runt-related osteoblast-specific transcription factor, is essential for osteoblast differentiation and function. Runx2 was identified as a key regulator of osteoblast-specific gene expression through its binding to the OSE2 element present in these genes. However, little is known about the signaling mechanism regulating Runx2 activity. This study examines the role of protein kinase C (PKC) pathway and mitogen-activated protein kinase (MAPK) pathway in regulating Runx2 and bone marker genes (osteopontin; OP, osteocalcin; OC). Luciferase assay and Northern blot analysis suggested that the stimulation of PKC by PMA increased transcription activity of Runx2 and bone marker genes (OP and OC) and also increased expression of Runx2. The stimulation of MAPK by okadaic acid increased transcription activity of Runx2 and bone marker genes (OP and OC). Pretreatment with PD98059 (Erk pathway inhibitor) and SB203580 (P38 pathway inhibitor) prior to PMA treatment decreased PMA stimulated Runx2 activity. Together these results indicate that both PKC and MAPKs are involved in the regulation of Runx2 activity and also the stimulation of Runx2 transcriptional activity by the PKC pathway is through activation of MAPK pathway.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.93-99
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• 2008

Until now, (-)-epigallocatechin-3-gallate(EGCG) is known as the most powerful antioxidant among green tea catechins having many beneficial effects on human skin. Considering that the content of catechins is variable according to many conditions such as solvent, temperature and pressure, we prepared the heat-epimerized-EGCG-mixture (HE-EGCG-mix) containing high content of gallocatechin-3-gallate(GCG) by epimerization during autoclaving process and found out its optimal condition for maximizing conversion from EGCG to GCG. To investigate the effects of EGCG and HE-EGCG-mix on skin barrier function, we performed in vivo experiments with hairless mice. We found that HE-EGCG-mix has more potent stimulating activity than EGCG for the production of involucrin 7(INV7) and for recovery of barrier function in SKH-1 mice. Also, we found that GCG stimulates $PPAR-{\alpha}$ transactivation more effectively than EGCG in vitro by transient transfection assay for $PPAR-{\alpha}$ activation activity. These imply that HE-EGCG-mix consisting of high content of GCG should stimulate more efficiently recovery of skin barrier through PPAR-mediated-kerationocyte differentiation than EGCG. In conclusion, our study may provide a possibility that GCG, the C-2 epimer of EGCG, could be a potentially effective agent for development of new cosmetics or health foods for recovery of skin barrier.

• The Korean Journal of Zoology
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• v.39 no.4
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• pp.378-386
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• 1996

We have developed a couple of new luciferase reporter plasmida with very low background reporter actlvltlea. One can be used to measure the promoter strength, after insertion of some promoter fragment into the reporter plasmid, and the other, with very low basal promoter actlvltlea, allis In studying eukaryotic transcriptional regulators. The latter reporter plasmid contains such cli elements as a 17 nucleotide long inftlator, Spl.blndIng sftes, GAL4 binding sltea, and bInding sitea for a certain Drosophila homeodomain proteins. In an attempt to construct an improved reporter plaimid by fadlltating transcriptional termination and minimizing any interference by cryptic promoters which may be preaent in the reporter pleamld DNA, we have inserted transsrlptional termination-related signals, a three tandem repeat of SV4O polyadenylatlon signal (AAA) and the putative transcrtptional termination signal (UMS) of the mouse c-mos gene, Into just upstream of the initIator, and the promoter actlvitiea were measured by a transIent expression assay employing the Drosophila Schneider line 2 cells. As expected, the basal promoter activitIes decreased maximally when both transcription termination related elements were inserted. Moreover, the reporter plasmld with the two elements allowed more sensitive measurement of transcriptional activation than the reporter piasmid without them. Theae reporter plasmids can be used for studying transcriptional regulators of higher organisms Including mammals as well as Droiophlla melanogaiter.

• Journal of Life Science
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• v.22 no.12
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• pp.1600-1607
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• 2012

The matrix metalloproteinase (MMP) family plays essential roles in physiological processes such as embryonic development, angiogenesis, wound healing, and tissue homeostasis as a consequence of MMPr capacity for breaking down many types of extracellular matrix proteins. Imbalanced regulation of MMP expression can also lead to pathological conditions such as tumor progression. We recently reported that the Drosophila Mmp1 gene is highly expressed in the digestive tract and is required for the maintenance of intestinal homeostasis such as by restriction of uncontrolled intestinal stem cell proliferation. However, the regulatory mechanisms of MMP gene expression in the intestine remain unclear. In this study, we determined that the expression of Mmp1 is regulated by the homeodomain transcription factor Caudal. Experiments using the targeted expression of Caudal under the regulation of Gal4-UAS system indicated that endogenous Caudal is required for the Mmp1 gene expression in the adult Drosophila intestine and that exogenous Caudal induces Mmp1 expression. Transient transfection experiments indicated that Caudal can activate the promoter activity of Mmp1 and that several putative Caudal binding sites in the 5'-flanking region of the Mmp1 gene may be critical to the upregulation by Caudal. Our data suggest that Mmp1 is one of the target genes of Caudal in physiological normal condition and in tumorigenesis.

• Journal of Life Science
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• v.13 no.4
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• pp.529-534
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• 2003

This study was done to investigated the phytosterol compositions of safflower (Carthamus tinctorius L.) seed. The phytoestrogen activity was also determined using CAT-ELISA Kit in ethanol extract of safflower seed. The phytosterol of safflower seeds was identified using gas chromatography-mass spectrometry after saponification of the oils. The phytosterol content and composition of safflower seed oils were 4% and identified stigmast-5-en-3-ol (3$\beta$, 24S)-form, ${\gamma}$-sitosterol (clionasterol) with Wiley MS spectrum library. The synergistic effect of human estrogen receptor (hER) has been investigated using a minimal chimeric promoters composed of the TATA region of the adenovirus-2 major late promoter (A22MLP) and two consensus perfectly polindromic Xenopus vitellogenin A2 gene estrogen responsive elements (XVEREl19). Transient transfection experiments in tile human breast adenocarcinoma cell line MCF-7, which is known to express the estrogen receptor endogenously, revealed that phytoestrogen from Carthamus tinctorius L. acts as estrogen. We have observed the transcriptional activities stimulated methanol and ethanol extract of safflower seed in MCF-7, were 0.43 and 0.37 respectively, compared to that by $\beta$-estradiol as 1.0. Our data showed that safflower seeds have estrogenic activity methanol and ethanol extracts and ethanol lower than that of $\beta$-estradiol. This result provides the first evidence that the beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of phytoestrogen ell bone-protecting.

• Journal of Life Science
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• v.32 no.11
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• pp.882-889
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• 2022

Breast cancer anti-estrogen resistance 3 (BCAR3) has been identified as one of the genes that induces anti-estrogen resistance in breast cancer. We have previously reported that BCAR3 activates promoters of c-Jun, activator protein-1, and the serum response element. In this study, we investigated the functional role of BCAR3 in the activation of the estrogen response element (ERE) in normal human breast MCF-12A cells. Transient expression of BCAR3 induced ERE activation, which was further increased by 17β-estradiol treatment but was not blocked by the anti-estrogen tamoxifen. Next, we studied the signaling pathway of BCAR3 leading to ERE activation. BCAR3-mediated ERE activation was inhibited by LY294002 and AZD5363, inhibitors of the phosphatidylinositol (PI) 3-kinase pathway, but not by PD98059 and U0126, inhibitors of the mitogen-activated protein kinase pathway. ERE activation was induced by the catalytic subunit p110α. of PI3-kinase or the active mutant of Akt, and this activation was not further increased by additional BCAR3 transfection. Based on these results, we propose that BCAR3 plays an important role in ERE activation through the PI3-kinase/Akt pathway in human breast MCF-12A cells.

• Journal of Life Science
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• v.19 no.11
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• pp.1529-1537
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• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.442-452
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• 2020

Backgroud: Sleep deprivation (SD) impairs learning and memory by inhibiting hippocampal functioning at molecular and cellular levels. Abnormal autophagy and apoptosis are closely associated with neurodegeneration in the central nervous system. This study is aimed to explore the alleviative effect and the underlying molecular mechanism of stem-leaf saponins of Panax notoginseng (SLSP) on the abnormal neuronal autophagy and apoptosis in hippocampus of mice with impaired learning and memory induced by SD. Methods: Mouse spatial learning and memory were assessed by Morris water maze test. Neuronal morphological changes were observed by Nissl staining. Autophagosome formation was examined by transmission electron microscopy, immunofluorescent staining, acridine orange staining, and transient transfection of the tf-LC3 plasmid. Apoptotic event was analyzed by flow cytometry after PI/annexin V staining. The expression or activation of autophagy and apoptosis-related proteins were detected by Western blotting assay. Results: SLSP was shown to improve the spatial learning and memory of mice after SD for 48 h, accomanied with restrained excessive autophage and apoptosis, whereas enhanced activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in hippocampal neurons. Meanwhile, it improved the aberrant autophagy and apoptosis induced by rapamycin and re-activated phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling transduction in HT-22 cells, a hippocampal neuronal cell line. Conclusion: SLSP could alleviate cognitive impairment induced by SD, which was achieved probably through suppressing the abnormal autophagy and apoptosis of hippocampal neurons. The findings may contribute to the clinical application of SLSP in the prevention or therapy of neurological disorders associated with SD.