• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.120-127
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• 1996

The characteristics of cell growth and poly-$\beta$-hydroxybutyrate biosynthesis of Alcaligenes latus ATCC 29713 were investigated. The PHB accumulation pattern of A. latus followed a growth-associated type where the cell growth and PHB accumulation were carried out simultaneously. Various intermediate compounds such as metabolites involved in the TCA cycle, amino acids, and saturated and unsaturated fatty acids were added to examine their effect on cell growth and PHB accumulation. Citrate, tyrosine, and palmitic acid showed the most significant increase both on cell growth and PHB accumulation. Maximum PHB concentrations were noticeably increased about 1.4 to 1.6 times higher than that of control, corresponding to 5.54, 6.45, and 6.45 g/l for citrate, tyrosine, and palmitic acid, respectively. The stimulatory effects of the supplemented metabolites were analyzed in terms of the increment of enzyme activities related to sugar catabolism and PHB biosynthesis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.188-188
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• 1996

In order to gain insight into the mechanism of the regulation of cytochrome P450IAl by arylhydrocarbon, the 5'-flanking region of a trout CYP450IAl 5'flanking DNA was cloned into pCAT-basic vector and it was transfected into Hepa-1 cells. 3MC treatment to hepa Ⅰ cells transfected with fish CYP450IAl-CAT construct results in mRNA increased by 2.81 fold when it was compared with that of control This increase of mRNA was decreased by concomitantly treated flavonoids such as morin. The levels of CAT mRNA that was treated with morin was 29.2-58.0% of 3MC stimulated CAT mRNA. Further investigation to find out if there are DRE, XRE or negative regulatory cis element in CYP450IA1 gene was undertaken. Results of the deletion study of 5'flanking DNA of trout P450IA indicate the existance of the negative(-1600 ～ -1300). CAT mRNA was about two-fold higher in deleted trout CYP450IAl-CAT construct transfected cells compared to the wi Id type trout CYP450IAl-CAT construct transfected cells. And The stimulatory effect of 3MC was no longer observed in col Is containing deleted CAT construct. [Supported by grants from the Korean Ministry of Education]

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.613-617
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• 1998

The Chsl, Chs2, and Chs3 activities of a pathogenic fungus, Candida albicans, perform the same biochemical reactions, but exert different functions. Therefore, the determination of each enzyme activity is important. The three chitin synthases differ in their optimal pH and the effect of divalent cations as either stimulatory or inhibitory factors. The CAChsl, CAChs2, and CAChs3 activities are optimal at pH 7.5, 6.5, and 8.5, respectively. $Co^{2+} stimulates CAChsl and CAChs3, but inhibits CAChs2. $Ni^{2＋}$ inhibits CAChsl and CAChs2 with little effect on CAChs3. $Mg^{2＋}$ stimulates CAChs2 and CAChs3, but hardly affects CAChsl. These characteristics are similar to those of the Saccharomyces cerevisiae enzymes except in degree. The sensitivity against $Ni^{2＋}$ of CAChsl is higher than that of CAChs2, whereas the reverse is true in S. cerevisiae. Metal dependence of chitin synthases in C. albicans is less marked than that in S. cerevisiae, except for CAChs2. The activities of CAChsl and CAChs3 from EDTA-treated membranes were increased 1.5 fold, while that of CAChs2 was stimulated 7 fold in the presence of divalent cations. These results could provide new criteria for screening systems of antifungal agents.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.251-257
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• 1995

The objective of the present study was to test the effect of platelet-activating factor (PAF) on rat alveolar macrophages. PAF alone did not stimulate superoxide secretion from alveolar macrophages. However, PAF $(10^{-5}\;M)$ significantly enhanced phagocytic activator zymosan-induced superoxide secretion from alveolar macrophages. This enhancement of PAF plus zymosan was 30% above the sum of the separate effects of PAF and zymosan. Similarly, PAF $1.3{\times}(10^{-5}\;M)$ was not a direct stimulant of alveolar macrophages, as it had no stimulatory effect on chemiluminescence generation, but potentiated zymosan-induced activation of chemiluminescence, i.e., 162% above the separate effects of each stimulant. PAF $10^{-16}{\pm}10^{-6}\;M$ also failed to stimulate IL-1 production from alveolar macrophages. In contrast, when both PAF $10^{-10}\;M$ and lipopolysaccharide(LPS) $(1 {\mu}g/ml)$ were added together at the initiation of the culture, IL-1 production was significantly increased indicating the potentiative effects of PAF on IL-1 production by alveolar macrophages. Collectively, these data suggest that PAF alone does not activate the release of bioactive products from alveolar macrophages. However, PAF appears to act as a priming mediator that potentiates stimuli-induced macrophage activity. These novel actions of PAF prove its role as a potent mediator of inflammatory and immune responses in the lung.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.6
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• pp.319-325
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• 2002

The induction of interleukin-6 (IL-6) using combined proinflammatory agents $(LPS/IFN-{\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ was studied in relation to p38 mitogen-activated protein kinase (MAPK) and $NF-{\kappa}B$ transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents $(LPS/IFN-[\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, $IFN-{\gamma}$ enhancement of $TNF-{\alpha}-induced\;NF-{\kappa}B$ binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on $TNF-{\alpha}/IFN-{\gamma}\;or\;LPS/IFN-{\gamma}-induced\;NF-{\kappa}B$ activation. This study strongly suggests that these pathways about $TNF-{\alpha}/IFN-{\gamma}$ or $LPS/IFN-{\gamma}-activated$ IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

• Korean Journal of Oriental Medicine
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• v.13 no.1 s.19
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• pp.139-145
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• 2007

Emodin is one of the main active components of a traditional Korean medicine isolated from the root and rhizomes of Rheum palmatum L. In this study, of 222 natural compounds to evaluate the anabolic activities, emodin activated bone morphogenetic protein (BMP)-2 promoter in the differentiation process of mouse osteoblastic MC3T3-E1 cells. Emodin was shown to significantly stimulate the activity and expression of alkaline phosphatase, an earlyphase marker of osteoblastic differentiation, on the differentiation day 7, and induce the osteopontin mRNA expression from the differentiation day 14. In addition, low concentration (up to 5 M) of emodin dramatically promoted the induction of mineralization in MC3T3-E1 subclone 4 cells. The stimulatory effect of emodin on the osteoblast differentiation/mineralization could be associated with its potential to stimulate the BMP-2 gene expression. Although further studies are needed to determine the precise mechanism, this study suggests that the use of herbal medicine containing natural compounds with anabolic activity such as emodin could have a beneficial effect on bone health.

• Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.70-75
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• 2004

The CMV promoter driven lacZ reporter gene (pcDNA-lacZ) was constructed and used for DNA immunization study. The expression of the lacZ gene was confirmed in vitro using RTG-2 cell line before using for in vivo study in olive flounder (Paralichthys olivaceus). In the dose response study, the maximum expression of the lacZ gene was found in the group injected with 5 ${\mu} g$ of the plasmid DNA. Kinetic study showed a significantly increased expression of $\beta-galactosidase$ gene at 7 days after injection. Effects of DNA vaccine on specific and nonspecific immune responses such as antibody and NO production were studied and the significant effect was found in olive flounder injected with 10 and 15 ${\mu} g$ DNA (sub optimal dose for lacZ gene expression). Two pro inflammatory cytokine genes, $IL-l\beta$ and $TNF-\alpha$, were also found to be up regulated in the muscle injected with the plasmid, suggesting an induction of local inflammatory response.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.105-105
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• 2001

In an attempt to provide useful information on the development of an artifitial nerve tubing, proliferative and migrative properties of two glioma cell lines, C6 rat glioma cells and Hs683 human glioma cells, were examined. The present study shows that C6 cells proliferated more rapidly than Hs683 cells. The Hs683 cells are more adequate for the development of nerve tubing since unlike C6 cells, they are of human origin and known to be non-tumorigenic. In order to enhance proliferative and migrative abilities of Hs683 cells for the application as an artificial nerve tubing, we studied the effect of glial cell-derived neurotrophic factor (GDNF) on Hs683 cells. Cells were seeded in the scaffolds (polymer constructs), fabricated with type I collegen and alginate modified with cinnamoyl moiety, in the presence or absence of GDNF Stimulatory effect of GDNF on the proliferation and migration of Hs683 cells cultured in the scaffolds is currently under investigation. In addition, possible neuroprotective activities of natural products which inhibit staurosporine-induced apoptosis of glioma cells are also being studied.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.79-84
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• 2010

The molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) protein is a novel member of the $Ikappa{\beta}$ family. In the present study, we examined the effect of norepinephrine (NE) on MAIL mRNA expression in primary cultured mouse hepatocytes and non-parenchymal liver cells. MAIL mRNA expression in hepatocytes and non-parenchymal liver cells was not directly influenced by NE. However, MAIL mRNA expression in hepatocytes was significantly induced by incubation with a culture medium of non-parenchymal liver cells, treated with NE. Pretreatment with an interleukin (IL)-1 receptor antagonist significantly attenuated the stimulatory effect of the medium. Moreover, exogenous $IL-1{\beta}$ induced MAIL mRNA expression in hepatocytes, while IL-6 and tumor necrosis factor $\alpha$ did not. The concentration of $IL-1{\beta}$ in the medium of non-parenchymal liver cells was significantly increased after NE-treatment. These results suggest that NE can induce MAIL mRNA expression in hepatocytes through $IL-1{\beta}$, released from non-parenchymal liver cells.

• Molecules and Cells
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• v.25 no.4
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• pp.504-509
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• 2008

Three G-protein-linked acetylcholine receptors (GARs) exist in the nematode C. elegans. GAR-3 is pharmacologically most similar to mammalian muscarinic acetylcholine receptors (mAChRs). We observed that carbachol stimulated ERK1/2 activation in Chinese hamster ovary (CHO) cells stably expressing GAR-3b, the predominant alternatively spliced isoform of GAR-3. This effect was substantially reduced by the phospholipase C (PLC) inhibitor U73122 and the protein kinase C (PKC) inhibitor GF109203X, implying that PLC and PKC are involved in this process. On the other hand, GAR-3b-mediated ERK1/2 activation was inhibited by treatment with forskolin, an adenylate cyclase (AC) activator. This inhibitory effect was blocked by H89, an inhibitor of cAMP-dependent protein kinase A (PKA). These results suggest that GAR-3b-mediated ERK1/2 activation is negatively regulated by cAMP through PKA. Together our data show that GAR-3b mediates ERK1/2 activation in CHO cells and that GAR-3b can couple to both stimulatory and inhibitory pathways to modulate ERK1/2.