• Journal of Life Science
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• v.17 no.2 s.82
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• pp.298-304
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• 2007

Salmonella is facultative intracellular pathogen that can survive and replicate in macrophages even though these cells are equipped with a plethora of anti-microbial mechanisms. To survive in this hostile intracellular environment, Salmonella has evolved numerous defense mechartisms. An approximately 20 kDa protein was detected as a stationary-phase specific protein band in cytosolic fraction. It was identified as a DNA binding protein in stationary phase (Dps) by analysis of MALDI-TOF assay. It has been known that Dps, the protein produced in the stationary phase of bacteria, allows DNA to form chromatin by binding to DNA nonspecifically and protects DNA from reactive oxidative species (ROS). For further study, Dps specific polyclonal antibodies were generated by injection of purified Dps protein into rabbit. To examine the Finfluence of several regulatory proteins in the expression dps gene, Dps protein level in various S. typhimurium mutants defecting regulatory proteins were investigated by Westernblot using Dps specific polyclonal antibodies.

• Journal of Life Science
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• v.26 no.1
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• pp.75-82
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• 2016

Pseudomonas rhodesiae KK1 has been reported to degrade polycyclic aromatic hydrocarbons (PAHs), such as anthracene, naphthalene, and phenanthrene, which are considered major environmental contaminants. Interestingly, antioxidant genes, including superoxide dismutase, are known to be expressed at different levels in response to environmental contaminants. This study was performed to identify the superoxide dismutase gene in strain KK1, which may be indirectly involved with degradation of PAHs, as well as to investigate the expression pattern of the superoxide dismutase gene in cells grown on different PAHs. Two types of superoxide dismutase genes responsible for the antioxidant defense mechanism, Mn-superoxide dismutase (sodA) and Fe-superoxide dismutase (sodB), were identified in P. rhodesiae KK1. The sodA gene in strain KK1 shared 95% similarity, based on 141 amino acids, with the Mn-sod of P. fluorescens Pf-5. The sodB strain, based on 135 amino acids, shared 99% similarity with the Fe-sod of P. fluorescens Pf-5. Southern hybridization using the sod gene fragment as a probe showed that at least two copies of superoxide dismutase genes exist in strain KK1. RT-PCR analysis revealed that the sodA and sodB genes were more strongly expressed in response to naphthalene and phenanthrene than to anthracene. Interestingly, sodA and sodB activities were revealed to be maintained in cells grown on all of the tested substrates, including glucose.

• Journal of Life Science
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• v.26 no.1
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• pp.8-16
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• 2016

Reactive oxygen species (ROS), at appropriate concentrations, mediate various normal cellular functions, including defense against pathogens, signal transduction, cellular growth, and gene expression. A recent study demonstrated that ROS and ROS-generating NADPH oxidase (Nox) are important in self-renewal and neuronal differentiation of subventricular zone (SVZ) neural stem cells in adult mouse brains. In this study, we found that endogenous ROS were detected in SVZ neural stem cells cultured from postnatal mouse brains. Nox4 was predominantly expressed in cultured cells, while the levels of the Nox1 and Nox2 transcripts were very low. In addition, the Nox4 gene was highly upregulated (by up to 10-fold) during neuronal differentiation. Immunocytochemical analysis detected the Nox4 protein mainly in neurons positive for the neuronal specific tubulin Tuj1. After differentiation, endogenous ROS were detected exclusively in neuron-like cells with processes. In addition, perturbation of the cellular redox state with N-acetyl cysteine, a ROS scavenger, during neuronal differentiation greatly inhibited neurogenesis. Lastly, knockdown of Nox4 using short hairpin RNA decreased neurogenesis. These findings suggest that Nox4 may be a major ROS-generating enzyme in postnatal SVZ neural stem cells, and Nox4-mediated ROS generation may be important in their neuronal differentiation.

• Journal of Life Science
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• v.20 no.11
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• pp.1577-1581
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• 2010

Granulocyte colony stimulating factor (G-CSF) is a hematopoietic cytokine that stimulates bone marrow cells to proliferate and differentiate into granulocytes. G-CSF is approved and used for therapeutic purposes. The endoplasmic reticulum (ER) signal peptide of hG-CSF was replaced with silkworm-specific signal peptides to express and efficiently secrete recombinant hG-CSF by silkworm cells. Plasmids that contain cDNAs for hG-CSF and hG-CSF fused with silkworm- specific signal peptides of prophenoloxidase activating enzyme (PPAE), protein disulfide isomerase (PDI), and bombyxin (BX) were constructed. The G-CSF protein was expressed in insect cell line BM5 and was detected by western blot analysis. The cells transfected with plasmids containing rhG-CSF genes with silkworm-specific signal sequences released mature rhG-CSF protein more efficiently than the cells transfected with pG-CSF, the plasmid containing human G-CSF gene, including its own signal sequence. The production of hG-CSF reached maximal level at four days post-transfection and remained at a high level until 7 days post-transfection. These data demonstrate that the modification of the human G-CSF mimic to insect proteins synthesized in ER greatly improves the production of the protein.

• Journal of Life Science
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• v.24 no.7
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• pp.750-756
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• 2014

Citrus, yield of which is the highest among fruits produced in Korea, is extensively consumed for processed food items. The amount of by-products of citrus produced from the processing within a short period after the harvest is tremendous. These by-products are mostly dumped into land or neglected because of cost involved in processing them. The aim of the present study was to explore the usefulness of the by-products as a new material by examining the anti-inflammatory activity of fermented extracts of citrus peels. The peels of 'unshu' (Citrus unshiu) was fermented with Aspergillus niger and their extracts before or after fermentation were analyzed using HPLC. The analysis showed that neohesperidin level considerably increased and the two new compounds were synthesized after fermentation. The anti-inflammatory activity of the fermented extracts was examined on RAW 264.7 murine macrophage cells stimulated with lipopolysaccharide. Fermented unshu extracts significantly enhanced the decrease of nitric oxide (NO) production, iNOS and COX-2 expression, comparing with those of unfermented extracts. Also TNF-${\alpha}$ and IL-6 production, both of which are pro-inflammatory cytokine, were more inhibited in fermented extracts. These results showed that the fermentation and promotion of the function of the by-products of citrus peels will help find a new application.

• Journal of Life Science
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• v.28 no.5
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• pp.509-516
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• 2018

Five phenolic compounds were isolated from the ethyl acetate fraction of leaves from Stewartia koreana, and their nitric-oxide (NO) inhibitory activities were measured to identify the major active constituents responsible for the efficacy of the extract against inflammatory reactions. These five compounds were quercetin (1), quercitrin (2), hyperin (3), quercetin-3-O-(6"-O-galloyl)-${\beta}$-D-galactopyranoside (4), and kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside (5). Among the separated compounds in the EtOAc fraction, compounds 4 and 5 were isolated for the first time, and no study has yet reported their anti-inflammatory effects. The compounds were identified by spectroscopic analysis, and the isolated compounds showed significant NO inhibitory effects in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Compound 5 showed the most potent inhibitory effect (63.35% inhibition) against LPS-induced NO production compared to that of compound 1 (17.17%), compound 2 (5.0%), compound 3 (3.92%), and compound 4 (6.32%) at $10{\mu}g/ml$ concentration. NO production was inhibited by suppressing the protein expression of inducible nitric-oxide synthase in LPS-stimulated RAW 264.7 macrophages. These results indicate that kaempferol 3-O-[2",6"-di-O-(trans-p-coumaroyl)]-${\beta}$-D-glucopyranoside might be the major active compound responsible for the anti-inflammatory effects of S. koreana.

• Herbal Formula Science
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• v.19 no.1
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• pp.195-205
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• 2011

Objectives : Ecklonia cava is brown alga(Laminariaceae) which grows is sea, it has antioxidant, diarrhea and anticoagulant effect. In this study, the effect of ethanol extract of Ecklonia cava (EC) on peptidoglycan(PGN) -induced NO production in RAW 264.7 cells was investigated. Methods : In the present study, IL-6 production was measured using the enzyme-linked immunosorbent assay(ELISA), prostaglandin $\E_2$($\PGE_2$) production was measured using the EIA kit, and inducible NO synthase(iNOS), cyclooxygenase-2(COX-2), and mitogen-activated protein kinase(MAPK) activation, as determined by western blot analysis and reverse transcription -polymerase chain reaction(RT-PCR). Results : EC inhibited PGN-induced NO and IL-6 production. Consistent with these observations, the protein expression of iNOS and COX-2 were inhibited by EC. Moreover, EC suppressed the phosphorylation of extracellular signal-regulated kinase(ERK) 1/2 in PGN-induced RAW 264.7. Conclusions : These results suggest that EC has inhibitory effects on PGN-induced $\PGE_2$, NO, and IL-6 production, as well as the expressions of iNOS and COX-2 in the murine macrophage. These inhibitory effects occur through blockades on the MAPKs phosphorylation.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.2
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• pp.31-48
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• 2011

Objectives : In order to investigate the anti-obesity effects of Wolbi-tang(here in after referred to WBT) on the obese gene and obese inhibitory, C57BL/6 mice were induced by high-fat diet. Methods : C57BL/6 mice were divided into 5 groups(normal, only high-fat diet, high-fat diet with Reductil, high-fat diet with WBT 400, 200 mg/kg extract) and fed for 5 weeks. And observed body weight change, total cholesterol, low density lipoprotein cholesterol(LDL-cholesterol), high density lipoprotein cholesterol (HDL-cholesterol), triglyceride, glucose, leptin change, alanine transaminase(ALT), aspartate transaminase(AST), serum creatinine, the expression of ${\beta}3$-adrenergic receptor(${\beta}3AR$), leptin, uncoupling protein(UCP2) gene in 3T3-L1 adipocyte, 3T3-L1 adipocyte proliferation, histological analysis of adipose tissue and liver tissue. Results : 1. Refer to cell cytotoxicity, viability of human fibroblast cells(hFCs) showed not significant changes. 2. The amount of ALT, AST was decreased significantly in WBT 400 mg/kg, 200 mg/kg groups. The amount of creatinine showed not significant changes. 3. Body weight was decreased significantly in WBT 400 mg/kg, 200 mg/kg groups. 4. The amount of total cholesterol and triglyceride was decreased significantly in WBT 400 mg/kg, 200 mg/kg groups. LDL-cholesterol was decreased and HDL-cholesterol was increased significantly in WBT 400 mg/kg groups. 5. The amount of glucose was decreased significantly in WBT 400 mg/kg groups. 6. The amount of serum leptin was decreased significantly in WBT 400 mg/kg, 200 mg/kg groups. 7. The revelation of ${\beta}3AR$ in 3T3-L1 adipocyte was increased significantly in WBT $100{\mu}g/ml$, $50{\mu}g/ml$ groups. The revelation of leptin was decreased significantly in WBT $100{\mu}g/ml$, $50{\mu}g/ml$ groups. The revelation of UCP2 was decreased significantly in WBT $100{\mu}g/ml$ group. 8. 3T3-L1 adipocyte proliferation was decreased significantly in WBT $100{\mu}g/ml$, $50{\mu}g/ml$ groups. The size of adipocyte was decreased relative to the control group in WBT 400 mg/kg group. 9. The adipose vacuoles in liver tissue was decreased relative to the control group. Conclusions : These results suggested that WBT has inhibitory effects of obesity. WBT might be applicated on treatment of obesity and metabolic syndrome. Further studies analysing its effects were needed.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1103-1109
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• 2018

Objective: This study aimed to screen and identify the target genes of miR-375 in pig Sertoli (ST) cells and to elucidate the effect of miR-375 on the proliferation of ST cells. Methods: In this study, bioinformatics software was used to predict and verify miR-375 target genes. Quantitative polymerase chain reaction (PCR) was used to detect the relationship between miR-375 and its target genes in ST cells. Enzyme-linked immunosorbent assay (ELISA) of rearranged L-myc fusion (RLF) and hypoxia-induced gene domain protein 1A (HIGD1A) was performed on porcine ST cells, which were transfected with a miR-375 mimics and inhibitor to verify the results. Dual luciferase reporter gene assays were performed to assess the interactions among miR-375, RLF, and HIGD1A. The effect of miR-375 on the proliferation of ST cells was analyzed by CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS). Results: Five possible target genes of miR-375, including RLF, HIGD1A, colorectal cancer associated 2, POU class 3 homeobox 1, and WW domain binding protein 1 like, were found. The results of quantitative PCR suggested that mRNA expression of RLF and HIGD1A had a negative correlation with miR-375, indicating that RLF and HIGD1A are likely the target genes of miR-375. The ELISA results revealed that RLF and HIGD1A were negatively correlated with the miR-375 protein level. The luminescence results for the miR-375 group cotransfected with wild-type RLF and HIGD1A vector were significantly lower than those of the miR-375 group co-transfected with the blank vector or mutant RLF and HIGD1A vectors. The present findings suggest that RLF and HIGD1A are target genes of miR-375 and that miR-375 inhibits ST cell proliferation according to MTS analysis. Conclusion: It was speculated that miR-375 affects cell proliferation through its target genes, which play an important role in the development of testicular tissue.

• Korean journal of communication and information
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• v.55
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• pp.50-73
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• 2011

This paper investigates the effectiveness of Real-Name System on Internet, which has been applied to some Internet service provider bulletin boards in Korea. The goal of the Real-Name system on the Internet is controlling expression of slanderous or abusive language. The effectiveness of the regulation is dependent on the people's perceptions and attitude toward to the legislation. This empirical study examines the antecedents that affect the perceptions and attitude toward the regulation. Further, we investigate the relationships among variables such as internet public sphere participation, attitude to the regulations, and intention to choose detours. Results of regression analysis show that the younger and the more progressive individuals are, the more they oppose the implementation of the law. Also, it was found that people who have more political interest and participate more actively in public sphere via internet, tend to oppose the law. Structural equation models reveal that participation in online public sphere drives negative attitudes about the regulation. In addition, people with negative perceptions about the law tend to choose the detours such as 'cyber asylum' and 'service asylum'.