• Biomedical Science Letters
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• v.13 no.4
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• pp.349-354
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• 2007

The purpose of this study was to examine the effect of vanillic acid on the cell viability and melanogenesis in melanocytes damaged by reactive oxygen species (ROS). The human skin melanoma cells (SK-MEL-3) were cultured with various concentrations of hydrogen peroxide $(H_2O_2)$. The cell viability for $H_2O_2$-induced cytotoxicity or vanillic acid against $H_2O_2$ was measured by XTT assay in these cultures. For the effect of vanillic acid on the melanogenesis, the tyrosinase inhibitory activity was measured by colorimetric assay at a wavelength of 490 nm, and melanin synthesis activity were assessed after cells were cultured in the media with or without various cencentrations of vanillic acid. In this study, $H_2O_2$ decreased cell viability dose- and time-dependent manners and $XTT_{50}$ was determined at a concentration of 80 ${\mu}M$, $H_2O_2$. Vanillic acid increased the cell viability dose dependently in human skin melanoma cells damaged by $H_2O_2$-induced cytotoxicity. In the tyrosinase inhibitory activity, vanillic acid supresssed tyrosinase activity in dosedependent manner, and also decreased significantly melanin synthesis activity compared with $H_2O_2$-treated group. From these results. It is suggested that $H_2O_2$-mediated cytotoxicity was highly by the toxic criteria of Borenfreund and Puerner and also, vanillic acid has the protective effect on ROS-induced cytotoxicity and melanogenesis in these cultures.

• BMB Reports
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• v.53 no.2
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• pp.118-123
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• 2020

Cardiac regeneration with adult stem-cell (ASC) therapy is a promising field to address advanced cardiovascular diseases. In addition, extracellular vesicles (EVs) from ASCs have been implicated in acting as paracrine factors to improve cardiac functions in ASC therapy. In our work, we isolated human cardiac mesenchymal stromal cells (h-CMSCs) by means of three-dimensional organ culture (3D culture) during ex vivo expansion of cardiac tissue, to compare the functional efficacy with human bone-marrow derived mesenchymal stem cells (h-BM-MSCs), one of the actively studied ASCs. We characterized the h-CMSCs as CD90^low, c-kit^negative, CD105^positive phenotype and these cells express NANOG, SOX2, and GATA4. To identify the more effective type of EVs for angiogenesis among the different sources of ASCs, we isolated EVs which were derived from CMSCs with either normoxic or hypoxic condition and BM-MSCs. Our in vitro tube-formation results demonstrated that the angiogenic effects of EVs from hypoxia-treated CMSCs (CMSC-Hpx EVs) were greater than the well-known effects of EVs from BM-MSCs (BM-MSC EVs), and these were even comparable to human vascular endothelial growth factor (hVEGF), a potent angiogenic factor. Therefore, we present here that CD90^lowc-kit^negativeCD105^positive CMSCs under hypoxic conditions secrete functionally superior EVs for in vitro angiogenesis. Our findings will allow more insights on understanding myocardial repair.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.731-737
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• 2013

Seventy-four Shiga toxin-producing Escherichia coli (STEC) isolates belonging to the serotype O91:H21 were isolated from 1,643 asymptomatic human carriers in a STEC outbreak at Gwangju in Korea. Although the isolates did not cause any symptoms, all of them produced Shiga toxins 1 (Stx1) and 2 (Stx2). In order to determine why these strains cause no symptoms, we explored the differences in virulence potential between the asymptomatic STEC O91:H21 isolates and symptomatic STEC O91:H21 strains (ATCC 51435 and ATCC 51434). The asymptomatic STEC O91:H21 isolates showed strongly reduced cytopathic effects compared with the symptomatic strains when intact bacterial cells were used as an inoculant. Moreover, we found a reduced adherence phenotype when testing asymptomatic strains on HeLa cells. Real-time quantitative PCR results suggest that transcriptional repression of the genes encoding type-1 fimbriae occurs in the asymptomatic isolates but not in the symptomatic strains.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5583-5586
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• 2014

Helicobacter pylori (H. pylori) infection induces apoptosis in gastric epithelial cells, and this occurrence may link to gastric carcinogenesis. However, the regulatory mechanism of H. pylori-induced apoptosis is not clear. MicroRNA-146a has been implicated as a key regulator of the immune system. This report describes our discovery of molecular mechanisms of microRNA-146a regulation of apoptosis in human gastric cancer cells. We found that overexpression of microRNA-146a by transfecting microRNA-146a mimics could significantly enhance apoptosis, and this upregulation was triggered by COX-2 inhibition. Furthermore, we found that microRNA-146a density was positively correlated with apoptosis rates in H. pylori-positive gastric cancer tissues and intratumoral microRNA-146a density was negatively correlated with lymph node metastasis among H. pylori-positive gastric cancer patients. Understanding the important roles of microRNA-146a in regulating cell apoptosis in H. pylori infected human gastric cancer cells will contribute to the development of microRNA targeted therapy in the future.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.2
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• pp.177-181
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• 2001

Recently, nonsteroidal anti-inflammatory drugs (NSAIDs) have been found to be useful in the chemoprevention of colon cancer. To investigate whether indomethacin, an NSAIDs, induces apoptosis and thus assess the possibility of its application in the chemoprevention of human lung cancer, we have performed MTT assay, TUNEL assay, DAPI staining, and flow cytometric analysis using human lung carcinoma cell line NCI-H1299. Through morphological and biochemical analyses, it was demonstrated that NCI-H1299 cells treated with indomethacin (0.5 mM) exhibit classical apoptotic features. These results suggest that indomethacin induces apoptosis in NCI-H1299 cells and that NSAIDs, including indomethacin, may be a useful tool for the chemoprevention of human lung cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.814-821
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• 1997

Kimchi is composed of many ingredients such as Chinese cabbage, garlic, ginger, and red pepper and fermented fish extract. Some of them were known to have antioxidative activities due to their scavenging effect against reactive oxygen species(ROS). To study the health effects of kimchi on human skin cells, keratinocyte(A431, epidermoid carcinoma, human) and fibroblast(CCD-986SK, normal control, human) were cultured in oxidative stress condition provoked by paraquat, a superoxide anion generator, and hydrogen peroxide in the absence and presence of kimchi extract. The survival rate of keratinocyte was greatly reduced when exposed over 1mM concentration of hydrogen peroxide($H_{2}O_{2}$), but cytotoxicity of $H_{2}O_{2}$ was significantly reduced by kimchi extracts on cells. Especially 2 week-fermented kimchi decreased remarkably the cytotoxicity by $H_{2}O_{2}$ to keratinocyte cells. Over 1mM of paraquat concentration showed strong cell toxicity on keratinocyte, but the extracts from kimchi fermented for 1, 2 and 3 weeks showed protective effects in order. Fibroblast cells were significantly affected by $H_{2}O_{2}$ as were keratinocyte cells. Although almost all extacts of kimchi of different fermentation periods showed protective effect against cell killing at 0.5mM concentration of $H_{2}O_{2}$ week-fermented kimchi extract showed the strongest protective effect on fibroblast cells treated with 1mM $H_{2}O_{2}$ for either 1 day or 4 days. However most of kimchi extracts showed weak preventive effect or no effect on oxidative stress produced by paraquat. In conclusion, 2 week-fermented kimchi extract seems to have the best potential in preventing skin cells against oxidative damage which might be related to their scavenging effects of kimchi components produced during their fermentation process.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.64-69
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• 1987

Monoclonal antibodies against human chorionic gonadotropin (hCG) were prepared and characterized by examining isotype, epitope binding, cross reactivity and affinity constants. And a sandwich type enzyme immunoassay for native hCG was developed with solid phase monoclonal antibody against the conformational determinant expressed only on native hCG and horseradish peroxidase conjugated monoclonal antibody against the $\beta$-subunit of hCG. The assay was sensitive to 1 mIU hCG/ml and shown a linear response up to 200 mIU hCG/ml. The cross reactivity for luteinizing hormone and $\beta$-subunit of hCG were 1% and 0.18%, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.1
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• pp.107-119
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• 1999

3 Kinds of PEG-hEGF conjugate, PEG5-hEGF, PEG5-hEGF, PEG10-hEGF, were synthesized. Major fractions containing 2 chains of PEG were separated by preparative GPC. Molecular weight was estimated by GPC-MALLS, TOF-Mass and SDS-PAGE, and the data were well corresponding to calculated one. The cell proliferation effect of the conjugates was evaluated, Indicating that the conjugate bound to longer chain PEG exhibits lower activity. Selective modification of hEGF and activity preservation of PEG-hEGF conjugate are undergoing.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.199-199
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• 2013

The distinctive cellular and mitochondrial dysfunctions of a human epithelial lung cancer cell line (H460) from a human lung fibroblastic normal cell line (MRC5) have been studied by dielectric barrier discharge (DBD) plasma treatment. The DBD plasma device have generated large amount of H2O2 and NOx in culture media which is dependent on plasma exposure time. It is found that the cell number of lung cancer cell H460 has been reduced more than the lung normal cell MRC5 as being increased exposure and incubation time. Also these both cell lines have showed mitochondria fragmentation under 5 minutes' plasma exposure, which is a clue of apoptosis. It is noted in this study that AnnexinV staining has showed not only early apoptosis, but also late apoptosis in lung cancer cell H460. Mitochondria enzyme activity and ATP generation have been also much reduced in lung cancer cell H460. Their mitochondrial membrane potential (${\Delta}{\psi}m$) has been found to be reduced in magnitude and shifted to the induced-potential level of cccp, while MRC5 mitochondrial membrane potential has been shifted slightly to that. These distinctively selective responses of lung cancer cell H460 from lung normal cell MRC5 gives us possibility of applying plasma to cancer therapy.

• BMB Reports
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• v.41 no.4
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• pp.300-304
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• 2008

The Dazl gene encodes a germ-cell-specific RNA-binding protein which is essential for spermatogenesis. It has been proposed that this protein (DAZL) binds to RNA in the cytoplasm of germ cells and controls spermatogenesis. Using the specific nucleic acids associated with proteins (SNAAP) technique, we identified 17 target mRNAs bound by mDAZL. Among these transcripts, we focused on TSSK2, which encodes a testis-specific serine/threonine kinase. To date, five TSSK family members have been cloned, and all are exclusively expressed in the testis. We demonstrated that in addition to the TSSK1 3'UTR, the 3'UTRs of TSSKs 2 and 4 were bound by human and mouse DAZL, and that human DAZL (hDAZL) bound to the 3'UTR of human TSSK5 (hTSSK5). Our results suggest that the Dazl gene may play different roles in human and mouse spermatogenesis by regulating different members of the downstream gene family.