• Korean journal of applied entomology
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• v.57 no.3
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• pp.165-175
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• 2018

Insects are known to live at wide range of temperature, but can not survive when they are exposed to over $40^{\circ}C$ or below supercooling point. The larvae of Helicoverpa assulta have been reared at high ($35^{\circ}C$), low (3 to $10^{\circ}C$), and room temperature ($25^{\circ}C$; control). To identify stress-related genes, the transcriptomes of fat body have been analyzed. Genes such as cuticular proteins, fatty acyl ${\Delta}9$ desaturase and glycerol 3 phosphate dehydrogenase were up-regulated whereas chitin synthase, catalase, and UDP-glycosyltransferase were down-regulated at low temperature. Superoxide dismutase, metallothionein 2, phosphoenolpyruvate carboxykinase and trehalose transporter have been up-regulated at high temperature. In addition, expressions of heat shock protein and glutathione peroxidase were increased at high temperature, but decreased at low temperature. These temperature-specific expressed genes can be available as markers for climate change of insect pests.

• BMB Reports
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• v.42 no.3
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• pp.136-141
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• 2009

Familial Amyotrophic lateral sclerosis (FALS) is a progressive neurodegenetative disorder induced by mutations of the SOD1 gene. Heat shock protein 27 (HSP27) is well-defined as a stress-inducible protein, however the its role in ALS protection has not yet been established. To investigate the role HSP27 may have in SOD1 mutant-mediated apoptosis, human SOD1 or HSP27 genes were fused with a PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame fusion protein, which was then transduced into cells. We found the purified PEP-1-HSP27 fusion proteins can be transduced efficiently into neuronal cells and protect against cell death by enhancing mutant SOD1 activity. Moreover, transduced PEP-1-HSP27 efficiently prevents protein aggregation produced by oxidative stress. These results suggest that transduced HSP27 fusion protein may be explored as a potential therapeutic agent for FALS patients.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.151-159
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• 2005

Injury caused by reactive oxygen species (ROS), known as oxidative stress, is one of the major damaging factors in plants exposed to environmental stress. Chloroplasts are specially sensitive to damage by ROS because electrons that escape from the photosynthetic electron transfer system are able to react with relatively high concentration of $O_2$ in chloroplasts. To cope with oxidative stress, plants have evolved an efficient ROS-scavenging enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX), and low molecular weight antioxidants including ascorbate, glutathione and phenolic compounds. To maintain the productivity of plants under the stress condition, it is possible to fortify the antioxidative mechanisms in the chloroplasts by manipulating the antioxidation genes. A powerful gene expression system with an appropriate promoter is key requisite for excellent stress-tolerant plants. We developed a strong oxidative stress-inducible peroxidase (SWPA2) promoter from cultured cells of sweetpotato (Ipomoea batatas) as an industrial platform technology to develop transgenic plants with enhanced tolerance to environmental stress. Recently, in order to develop transgenic sweetpotato (tv. Yulmi) and potato (Solanum tuberosum L. cv. Atlantic and Superior) plants with enhanced tolerance to multiple stress, the genes of both CuZnSOD and APX were expressed in chloroplasts under the control of an SWPA2 promoter (referred to SSA plants). As expected, SSA sweetpotato and potato plants showed enhanced tolerance to methyl viologen-mediated oxidative stress. In addition, SSA plants showed enhanced tolerance to multiple stresses such as temperature stress, drought and sulphur dioxide. Our results strongly suggested that the rational manipulation of antioxidative mechanism in chloroplasts will be applicable to the development of all plant species with enhanced tolerance to multiple environmental stresses to contribute in solving the global food and environmental problems in the 21st century.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.2
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• pp.109-116
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• 2007

Environmental stress is the major limiting factor in plant productivity. As an effort to solve the global food and environmental problems using the plant biotechnology, we have developed transgenic tall fescue (Festuca arundinacea Schreb.) plants via Agrobacterium-mediated gene transfer method. To develop transgenic tall fescue plants with enhanced tolerance to the environmental stresses, both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) genes were incorporated in a pIG121 binary vector and the both of the genes were controlled separately by an oxidative stress-inducible sweet potato peroxidase 2 (SWPA2) premoter expressed in chloroplasts. Leaf discs of transgenic plants showed 10-30% less damage compared to the wild-type when they exposed to a wide range of environmental stresses including methyl viologen (MV), $H_2O_2$ and heavy metals. In addition, when $200{\mu}M$ MV was sprayed onto the whole plants, transgenic plants showed a significant reduction of visible damage compared to wild-type plants that were almost damaged. These results suggest that over expression of CuZnSOD and APX genes in transgenic plants might be a useful strategy to protect the crops against a wide range of environmental stresses.

• Food Science and Preservation
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• v.19 no.3
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• pp.443-450
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• 2012

Recently, NADPH oxidase 4 (NOX4)-mediated generation of intracellular reactive oxygen species (ROS) was proposed to accelerate adipogenesis of 3T3-L1 cell. We have previously shown that Cheonnyuncho (Opuntia humifusa) extract significantly inhibited adipocyte differentiation via downregulation of $PPAR{\gamma}$ (peroxisome proliferator-activated receptor gamma) gene expression. In this study, we focused on the molecular mechanism(s) of NOX4, G6PDH (glucose-6-phosphate dehydrogenase) and antioxidant enzymes in anti-oxidative activities of 3T3-L1 adipocytes. Our results indicate that Cheonnyuncho extracts markedly inhibits ROS production during adipogenesis in 3T3-L1 cells. Cheonnyuncho extracts suppressed the mRNA expression of the pro-oxidant enzyme such as NOX4 and the NADPH-producing G6PDH enzyme. In addition, treatment with Cheonnyuncho extract was found to upregulate mRNA levels of antioxidant enzymes such as Mn-SOD (manganese-superoxide dismutase), Cu/Zn-SOD (copper/zinc-SOD), glutathione peroxidase (GPx), glutathion reductase (GR), and catalase, all of which are important for endogenous antioxidant responses. These data suggest that Cheonnyuncho extract may be effective in preventing the rise of oxidative stress during adipocyte differentiation through mechanism(s) that involves direct down regulation of NOX4 and G6PDH gene expression or via upregulation of endogenous antioxidant responses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.437-442
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• 2012

Red yeast rice (RER) has been used in China for centuries for its medicinal properties and is an increasingly popular alternative lipid-lowering treatment. This study was carried out to estimate the antioxidant properties of RER extracts. The ethyl acetate extract exhibited the DPPH radical scavenging activity of 85% at 0.2 mg/mL and $IC_{50}$ 0.13 mg/mL. A significant proportion of hydroxyl radicals in a cuvette were scavenged: 44.2% at 2.5 ${\mu}g$/mL, 74.1% at 5.0 ${\mu}g$/mL, and >100% at 10 ${\mu}g$/mL. The $HepG_2$ cells pre-treated with RER ethyl acetate extract reduced the hydroxyl radicals significantly compared to the control cells. Oxidative DNA damage was measured using a Comet assay. The RER ethyl acetate extract did not induce any DNA damage per se, and appeared to enhance the resistance to DNA damage caused by an oxidant challenge with $H_2O_2$, whereas lovastatin increased the level of DNA damage in the cells in both the unstressed (no oxidant) and those stressed with $H_2O_2$. The relative gene expression of the antioxidant enzymes in $HepG_2$ cells were also affected by the RER ethyl acetate extract. The $HepG_2$ cells were pre-incubated with the RER ethyl acetate extract, and then stressed with $H_2O_2$ or left unstressed (no oxidant). In the unstressed cells, superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (GPx) were increased significantly 3.25-fold and 2.67-fold, respectively, whereas in the stressed cells, the catalase (CAT) level was increased by 4.64-fold and 7.0-fold at 5 ${\mu}g$/mL and 10 ${\mu}g$/mL, respectively, compared to those of the control. From these results, RER appears to be effective in suppressing oxidative stress.