• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.83-83
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• 2003

In our previous study, glucose deprivation was reported to induce the potentiated death and ATP loss in immunostimulated astroglia. And this vulnerability to glucose deprivation was due to overproduction of nitric oxide (NO) and hydrogen peroxide (H$_2$O$_2$). In the present study, the role of extracellular signal-regulated kinase 1/2 (ERK1/2) in the glucose deprivation-induced death of immunostimulated astroglia was examined. We showed that immunostimulation with LPS+IFN-ν activated the ERKl/2 signal pathway and produced a large amount of NO and H$_2$O$_2$. Generation of NO and H$_2$O$_2$ in immunostimulated astroglia was mediated via ERK1/2 signal pathways, since addition of the ERK kinase (MEKl) inhibitor PD98059 reduced NO and H$_2$O$_2$production. ERK1/2 activation-mediated NO and H$_2$O$_2$ production is due to an activation of iNOS and NADPH oxidase, respectively. Finally, we found that glucose deprivation caused ATP depletion and the augmented death in immunostimulated astroglia, which was also prevented by PD98059 treatment. These results demonstrate that the ERK1/2 signal pathways play an important role in glucose deprivation induced the death in immunostimulated astroglia by regulating the generation of NO and H$_2$O$_2$.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.272-277
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• 2011

Plants expressing Agrobacterium sp. strain CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) are known to be resistant to glyphosate, a potent herbicide that inhibits the activity of the endogenous plant EPSPS. In order to develop herbicide-resistant rice, we prepared transgenic rice plants with CP4 EPSPS gene under the control of CaMV 35S promoter for over-expression. A recombinant plasmid was transformed into rice via Agrobacterium-mediated transformation. A large number of transgenic rice plants were obtained with glyphosate and most of the transformants showed fertile. The integration and expression of CP4 EPSPS gene from regenerated plants was analyzed by Southern and northern blot analysis. The transgenic rice plants had CP4 EPSPS enzyme activity levels more than 15-fold higher than the wild-type plants. EPSPS enzyme activity of transgenic rice plants was also identified by strip-test method. Field trial of transgenic rice plants further confirmed that they can be selectively survived at 100% by spay of glyphosate (Roundup$^{(R)}$) at a regular dose used for conventional rice weed control.

• Molecules and Cells
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• v.25 no.2
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• pp.231-241
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• 2008

Indole glucosinolates (IG) play important roles in plant defense, plant-insect interactions, and stress responses in plants. In an attempt to metabolically engineer the IG pathway flux in Chinese cabbage, three important Arabidopsis cDNAs, CYP79B2, CYP79B3, and CYP83B1, were introduced into Chinese cabbage by Agrobacterium-mediated transformation. Overexpression of CYP79B3 or CYP83B1 did not affect IG accumulation levels, and overexpression of CYP79B2 or CYP79B3 prevented the transformed callus from being regenerated, displaying the phenotype of indole-3-acetic acid (IAA) overproduction. However, when CYP83B1 was overexpressed together with CYP79B2 and/or CYP79B3, the transformed calli were regenerated into whole plants that accumulated higher levels of glucobrassicin, 4-hydroxy glucobrassicin, and 4-methoxy glucobrassicin than wild-type controls. This result suggests that the flux in Chinese cabbage is predominantly channeled into IAA biosynthesis so that coordinate expression of the two consecutive enzymes is needed to divert the flux into IG biosynthesis. With regard to IG accumulation, overexpression of all three cDNAs was no better than overexpression of the two cDNAs. The content of neoglucobrassicin remained unchanged in all transgenic plants. Although glucobrassicin was most directly affected by overexpression of the transgenes, elevated levels of the parent IG, glucobrassicin, were not always accompanied by increases in 4-hydroxy and 4-methoxy glucobrassicin. However, one transgenic line producing about 8-fold increased glucobrassicin also accumulated at least 2.5 fold more 4-hydroxy and 4-methoxy glucobrassicin. This implies that a large glucobrassicin pool exceeding some threshold level drives the flux into the side chain modification pathway. Aliphatic glucosinolate content was not affected in any of the transgenic plants.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.30-36
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• 2002

To use overproduction muskmelon effectively, muskmelon vinegar was prepared by two stage fermentations of alcohol and acetic acid. In the alcohol fermentation using muskmelon, alcohol content showed maximum value (7.47%) in $17.83^{\circ}Brix$ of initial sugar concentration and 82.65 h of fermentation time. Acetic acid content in alcohol fermentation revealed minimum value (0.46%) in $12.17^{\circ}Brix$ of initial sugar concentration and 60.56 h of fermentation time. The fermentation conditions for minimum residual sugar were $10.02^{\circ}Brix$ of initial sugar concentration and 105.61 h of fermentation time. The optimum conditions predicted for each corresponding physical properties of acetic acid fermentation were 200 rpm (agitation rate), 250 h (fermentation time) in acetic content and 200 rpm, 150 h in residual alcohol content.

• The Journal of Internal Korean Medicine
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• v.34 no.1
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• pp.14-30
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• 2013

Objectives : The aim of this study was to investigate whether the effects of extract from Saengkankunbi-tang and its composition that Artimisiae capillaris Herba, Crataegi Fructus, Alismatis Rhizoma, Hoelen and Raphani Semen could protect HepG2 cells from palmitic acid-induced lipotoxicity through lysosomal and mitochondrial pathways in an in vitro model. Methods : To examine the effects of the extracts from Saengkankunbi-tang and its composition that Artimisiae capillaris Herba, Crataegi Fructus, Alismatis Rhizoma, Hoelen and Raphani Semen on palmitic acid-induced lipotoxicity in HepG2 cells, we measured the contents of cell viability, cytotoxicity. Then to investigate the effects of the extract from Saengkankunbi-tang, Artimisiae capillaris Herba and Raphani Semen, we measured that triglyceride, reactive oxygen species, ATP levels, glutathione levels, cytochrome c and cathepsin B. Results : The extracts from Saengkankunbi-tang and its composition had a cell-protective function. The extracts from Saengkankunbi-tang, Artimisiae capillaris Herba and Raphani Semen controlled triglyceride over-accumulation in cells and reduced overproduction of reactive oxygen species. The extracts from Saengkankunbi-tang and Raphani Semen increased ATP and glutathione levels which had been decreased by lipotoxicity. The extracts from Saengkankunbi-tang, Artimisiae capillaris Herba and Raphani Semen reduced leakage of cytochrome c and the extracts from Saengkankunbi-tang and Raphani Semen reduced leakage of cathepsin B in lipotoxicity. Conclusions : These results show that the extracts from Saengkankunbi-tang and its composition that Artimisiae capillaris Herba and Raphani Semen have cell protective effects on palmitic acid-induced lipotoxicity through lysosomal and mitochondrial pathways.

• Food Science of Animal Resources
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• v.40 no.2
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• pp.274-285
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• 2020

In this study, ovalbumin (OVA) hydrolysates were prepared using various proteolytic enzymes and the anti-inflammatory activities of the hydrolysates were determined. Also, the potential application of OVA as a functional food material was discussed. The effect of OVA hydrolysates on the inhibition of nitric oxide (NO) production was evaluated via the Griess reaction, and their effects on the expression of inducible NO synthase (inducible nitric oxide synthase, iNOS) were assessed using the quantitative real-time PCR and Western blotting. To determine the mechanism by which OVA hydrolysates activate macrophages, pathways associated with the mitogen-activated protein kinase (MAPK) signaling were evaluated. When the OVA hydrolysates were added to RAW 264.7 cells without lipopolysaccharide (LPS) stimulation, they did not affect the production of NO. However, both the OVA-Protex 6L hydrolysate (OHPT) and OVA-trypsin hydrolysate (OHT) inhibited NO production dose-dependently in LPS-stimulated RAW 264.7 cells. Especially, OHT showed a strong NO-inhibitory activity (62.35% at 2 mg/mL) and suppressed iNOS production and the mRNA expression for iNOS (p<0.05). Also, OHT treatment decreased the phosphorylation levels of Jun amino-terminal kinases (JNK) and extracellular signal-regulated kinases (ERK) in the MAPK signaling pathway. These findings suggested that OVA hydrolysates could be used as an anti-inflammatory agent that prevent the overproduction of NO.

• BMB Reports
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• v.44 no.5
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• pp.298-305
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• 2011

Most intracellular reactive oxygen species (ROS), especially superoxide anion ($O_2^{{\bullet}_-}$) that is converted from oxygen, are overproduced by excessive electron leakage from the mitochondrial respiratory chain. Intracellular oxidative stress that damages cellular components can contribute to lifestyle-related diseases such as diabetes and arteriosclerosis, and age-related diseases such as cancer and neuronal degenerative diseases. We have previously demonstrated that the excessive mitochondrial $O_2^{{\bullet}_-}$ production caused by SDHC mutations (G71E in C. elegans, I71E in Drosophila and V69E in mouse) results in premature death in C. elegans and Drosophila, cancer in mouse embryonic fibroblast cells and infertility in transgenic mice. SDHC is a subunit of mitochondrial complex II. In humans, it has been reported that mutations in SDHB, SDHC or SDHD often result in inherited head and neck paragangliomas (PGLs). Recently, we established Tet-mev-1 conditional transgenic mice using our uniquely developed Tet-On/Off system, which equilibrates transgene expression to endogenous levels. These mice experienced mitochondrial respiratory chain dysfunction that resulted in $O_2^{{\bullet}_-}$ overproduction. The mitochondrial oxidative stress caused excessive apoptosis leading to low birth weight and growth retardation in the neonatal developmental phase in Tet-mev-1 mice. Here, we briefly describe the relationships between mitochondrial $O_2^{{\bullet}_-}$ and aging phenomena in mev-1 animal models

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.288-296
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• 1995

To investigate high-level expression of Serratia marcescens metalloprotease (SMP) in Escherichia coli and S. marcescens, we constructed various recombinant plasmids: pSP2, containing SMP gene and lac promoter; pKSP2, containing SMP gene and tac promoter; pTSP2, containing SMP gene, trc99a promoter, and lacI$^{q}$. The recombinant E. coli (pKSP2) strain expressed SMP to a high-level, about 36% of total cellular proteins but accumulated inactive SMP precursors intracellularly, which indicated that E. coli does not have activation and secretion system for SMP. To overproduce active SMP, we transformed S. marcescens with the recombinant plasmids by a modified CaCl$_{2}$ method. The recombinant S. marcescens ATCC27117 (pSP2) containing lac promoter for SMP transcription produced 530 U/ml of active SMP on LB broth, which is about 5.1 times of the SMP yield, 105 U/ml of a control strain, S. marcescens ATCC27117 (pUC19). However, S. marcescens ATCC27117 (pKSP2) containing tac promoter for SMP transcription did not grow healthy and hardly produced SMP. To overcome a harmful effect of the strong tac promoter, we constructed a regulatory plasmid pTSP2 containing a strong trc99a promoter and its repressor gene lacI$^{q}$. When S. marcescens ATCC27117 (pTSP2) was induced with 1.0 mM IPTG after 9 hr cultivation, 2,200 U/ml of SMP was obtained in LB broth, which is about 21 times of that of a control strain.

• Nutritional Sciences
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• v.9 no.2
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• pp.117-123
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• 2006

G. japonicum is a perennial hem and the flowering plant has been used as a diuretic and an astringent in Japan and China. However, little information is available about the anti-inflammatory action of G. japonicum. Therefore, the objective of this study was to investigate the antiinflammatory action of fractions from G. japonicum methanol extract. Inhibition of NO production was observed when cells were cotreated with fractions of G. japonicum and lipopolysaccharide. We observed that ethyl acetate fraction of G. japonicum inhibited NO production by LPS-activated RAW 264.7 cells, and that the suppression induced by ethyl acetate fraction of G. japonicum was associated with antioxidant activity and direct NO clearance. In addition, only ethyl acetate fraction of G. japonicum inhibited stimulated $PGE_2,\;TNF-\alpha,\;IL-1\beta$ production, whereas water and methyl chloride fractions showed no such effects. The ethyl acetate fraction of G. japonicum methanol extract showed a remarkable scavenging activity on the 1,1-diphenyl-2 picrylhydrazyl radical. Based on the results, ethyl acetate fraction of G. japonicum may be useful source as natural antioxidants and antiinflammation. Therefore, the results obtained from this study provide an alternative protective mechanism of ethyl acetate fraction of G. japonicum and provide information on the potential use of ethyl acetate fraction of G. japonicum in chemoprevention or pathogenic conditions related to overproduction of NO and $PGE_2$. However, the mechanism of the inflammatory effect must be evaluated through various parameters for induction of NO production.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.68-72
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• 2002

While the biosynthetic gene cluster encoding the pigmented antibiotic actinorhodin is present in the two closely related bacterial species, Streptomyces lividans and Streptomyces coelicolor, it normally is expressed only in S. coelicolor---generating the deep blue colonies responsible for the S. coelicolor name. However, multiple copies of the afsR2 gene, which activates actinorhodin synthesis, result in the ability of S. lividansto also synthesize large amounts of actinorhodin. Here we report that the phenotypic property that historicially distinguishes these two Streptomycesspecies is determined conditionally by the carbon source used for culture. Whereas growth on glucose repressed actinorhodin production in S. lividans, culture on solid media containing glycerol as the sole carbon source dramatically increased the expression of afsR2 mRNA---leading to extensive actinorhodin synthesis by S. lividansand obliterating its phenotypic distinction from S. coelicolor. afsR2 transcription under these conditions was developmentally regulated, rising sharply at the time of aerial mycelium formation and coinciding temporally with the onset of actinorhodin production. Our results, which identify media-dependent parallel pathways that regulate actinorhodin synthesis in S. lividans, demonstrate carbon source control of actinorhodin production through the regulation of afsR2 mRNA synthesis. The nucleotide sequences of afsR2 revealed two putative important domains; the domain containing direct repeats in the middle and the domain homologous to sigma factor sequence in the C-terminal end. In this work, we constructed various sized afsR2-derivatives and compared the actinorhodin stimulating effects in S. lividans TK21. The experimental data indicate that the domain homologous to sigma factor sequence in the C-terminal end of afsR2 plays a critical role as an antibiotic stimulating function. In addition, we also observed that the single copy integration of afsR2 regulatory gene into S. lividans TK21 chromosome significantly activates antibiotic overproduction.