• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2002.04b
• /
• pp.49-58
• /
• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21st century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Journal of Plant Biotechnology
• /
• v.29 no.2
• /
• pp.69-77
• /
• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21st century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (lpomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.313-317
• /
• 2005

Synthetic gene carriers such as poly-cationic polymers easily form complexes with plasmid DNA which contains negative charge. Chitosan is a polysaccharide that demonstrates much potential as a gene delivery system. The ability of depolymerized chitosan to condense DNA was determined using electrophoresis. Dynamic laser scattering and scanning electron microscopy were used to examine the size and the morphology of the chitosan/DNA complex. Parameters such as chitosan molecular weight and charge density influenced the complex size and the DNA amount condensed with chitosan. The cell viabilities in the presence of chitosan ranged between 84-108% of the control in all experiments. Gene expression efficacy using chitosan/DNA complex was enhanced in 293 cells relative to that using naked DNA, although it was lower than that using lipofecamine. Transfection efficacy using low molecular weight chitosan (Mw=8,517) was higher than those of the control and the other chitosan (MW=4,078). The low molecular weight chitosan (MW=8,517) with a high charge density (18.32 mV) fulfilled the requirements for a suitable model gene delivery system with respect to the condensing ability of DNA, complex formation, and transfection efficacy.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.4
• /
• pp.391-395
• /
• 2018

Increasing demands for zirconia material in clinics, assessment of biocompatibility of zirconia is essential. In this article, a review of in vitro studies of zirconia compatibility was performed. Zirconia showed great biocompatibility at in vitro studies with various cell lines such as fibroblasts, osteoblasts, and lymphocytes. Many studies reported that zirconia caused no cytotoxicity or mutation. Zirconia also showed less bacterial adhesion. There were no adverse effects except for small reduced strength with in vitro study mimicking long-term exposure of body fluid. According to the study with ostoblast-like cells, zirconia could regulate genes of immunity, molecular transport, and cell cycle. Such gene regulating was considered as one of the reasons of zirconia biocompatibility. With biocompatibility of zirconia powders, in vitro studies had controversial conclusions. It seems that zirconia powders might have cytotoxicity.

• Polymer(Korea)
• /
• v.31 no.5
• /
• pp.454-459
• /
• 2007

Gene therapy using low molecular weight water soluble chitosan (LMWSC) as polycationic polymer shows good biocompatibility, but low transfection efficiency. The mechanism of folic acid (FA) uptake in the cells to promote targeting and internalization could improve transfection rates. The objective of this study was to synthesize and characterize the WSCFA-DNA complex and evaluate their cytotoxicity, in vitro. In $^1H-NMR$ spectra, specific peaks appeared both of FA and LMWSC in $D_2O$. WSCFA nanoparticles have spherical shapes with particle size show below 110 nm. In the cell cytotoxicity test, the WSCFA-DNA complex showed high cell viability, in vitro. Gel electrophoresis showed condensed DNA within the carriers. hi vitro transfection efficiency was assayed by fluorescence spectroscopy WSCFA nanoparticles have less cytotoxicity, good DNA condensation and particle size around 110 nm, which makes them a promising candidate as a non-viral gene vector.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 1997.10a
• /
• pp.38-42
• /
• 1997

Human growth hormone is known as one of the peptide hormones which is consisted of 191 amino acids derived from the pituitary gland in humans. The objectives of this study were to supply inexpensive recombinant methionyl human growth hormones (rHGH) synthesized by the DNA technology in a yeast cell line and followed by the establishement of protein purification techniques. The next steps of the research were to study its physic-chemical properties and biological properties, and to evaluate various preclinical aspcts including pharmacokinetics sutdy, general pharmacology study, general toxicity test, and specific toxicity tests. Clinical phase I, II, III studies were also done against growth hormone dficient children to reveal that growth promoting effects were similar compared with the natural HGH extracted from pituitary glands and commercially available rHGHs. The results could be summarized that (I) this yeast dervied rHGH have had excellent physico-chemical and biological properties in comparison with a natural HGH and other synthesized rHGHs, (2) we could not see any toxic side effects when very high doses were administered to the experimental animals, and (3) this growth hormone showed effectiveness in the growth stimulating to growth hormone deficient patients.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.37-37
• /
• 2019

벼 재배포장에서 화학약제의 반복적인 사용으로 인한 병원균의 약제내성과 환경오염은 커다란 문제가 되고 있다. 이러한 약제내성을 극복하기 위한 노력의 하나로 유전자수준의 약제내성기작의 규명과 대체물질의 발굴이 필요하다고 사료된다. 이에 본 연구에서는 식물종이 지니는 광범위한 다양성에 주목하였고, 700여 종의 식물추출물을 벼 도열병균에 처리해 균사성장억제효과를 조사하는 선별실험을 실시하였고, 영릉향과 지모추출물이 높은 균사성장억제효과를 보이는 것을 확인했다. 영릉향과 지모 추출물이 화학약제를 대체하는 대안물질로서 가능성을 조사하기위해 균사성장억제능력 확인실험, 분획, HPLC (High Performance Liquid Chromatography), 포자발아 및 부착기 형성확인검정, ABC transporter의 발현조사, 환경독성실험등을 실시했다. 실험 결과, 영릉향과 지모 추출물을 벼 도열병균에 처리하였을 때 약제저항성유전자 ABC transporter의 기능이 저하되고 화학약제에 대한 내성이 감소를 확인했으며, 분획과 HPLC분석을 통해 영릉향과 지모의 유효성분을 확인했다. 또한, 실제 포장에서 영릉향 추출물과 지모 추출물을 사용하여 벼 도열병 방제가를 확인하는 포장시험을 실시한 결과, 각각 63%와 62%의 목 도열병 방제가를 확인 하였으며, 인축환경에 대한 유해성을 조사하기 위해 어류, 설치류, 중치류, 곤충을 대상으로 영릉향 추출물을 처리해 급성독성시험 실시한 결과, 고농도의 투여량에서도 독성이 없는 것을 확인했다. 위의 실험 결과를 토대로, 영릉향과 지모추출물이 화학농약에 의한 환경오염을 막을 수 있고, 인축과 환경에 피해를 입히지 않는 친환경자재로 친환경적인 생물농약의 신소재로서 가능성을 나타냈다고 사료된다.

• Journal of Radiation Protection and Research
• /
• v.22 no.1
• /
• pp.15-21
• /
• 1997

In vitro somatic mutation induced by ${\gamma}$-radiation and pentachlorophenol(PCP) which is representative of chemical pollutant was measured at the hypoxanthine-guanine phosphoribosyl transferase(hprt) locus in human T- lymphocytes by a cell cloning assay. Mutant cells were selected by their ability to form a clone in the presence of purine analogue 6-thioguanine. The mutant frequencies by ${\gamma}$-irradiation to a dose of 1.0 Gy, 2.0 Gy and 3.0 Gy were 40%, 400% and 750% higher than those in controls. Significant changes were not observed in mutant frequencies in the 0.2 Gy and 0.5 Gy irradiated groups. When the doses of PCP were 15 ppm, 25 ppm and 50 ppm, the mutant frequencies increased by 30%, 90% and 520%, respectively. No changes were observed in the 10 ppm treated group. Similar types of dose-response relationship were shown in the two different mutagens. Reverse transcriptase/polymerase chain reaction technique(RT/PCR) was needed for the mutation spectrum to discriminate combined exposure to radiation and chemicals.

• Korean Journal of Plant Tissue Culture
• /
• v.24 no.2
• /
• pp.93-97
• /
• 1997

For the molecular genetic study of cold tolerance mechanism in plants, a cDNA encoding fatty acid desaturase (fad3), converting linoleic acid (18:2, $\omega$-6) to linolenic acid (18:3, $\omega$-3), was isolated from $\lambda$ZAPII Arabidopsis thaliana cDNA expression library by plaque hybridization using fad3 cDNA probe derived from Brassica napus. A 1.8 kb-EcoRI fragment from a lambda clone showing a strong positive hybridization signal was subcloned into pGEM7 and analyzed for its nucleotide sequence. From deduced amino acid sequences, the fad3 gene was revealed to have an open reading frame(ORF) consisting of 386 amino acids with a molecular mass of 44,075 Da. The fad3 gene was compared to chloroplast $\omega$-3 fatty acid desaturase (fad7) and endoplasmic reticulum Δ12 fatty acid desaturase (fad2) to show 70% and 58% amino acid sequence homology, respectively, Especially, amino acids of internal (82 to 151) and carboxy terminal (276 to 333) regions were highly conserved, implying their requisite role for enzymatic functioning of fatty acid desaturases. IPTG-induced fad3 cDNA expression in E. coli cells was suggested to be toxic to bacterial growth.

• Korean Journal of Weed Science
• /
• v.15 no.3
• /
• pp.206-213
• /
• 1995

Glyphosate(N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves(i.e. third old leaf) of tomato(Lycopersicon esculentum Mil var. Moneymaker). Herbicide binding protein, QB protein(D1), has been immunoblotted using the antibodies raised against the hybrid-protein expressed by a part of spinach psb A gene cloned in frame with the 3'end of lac Z gene to allow expression of the ${\beta}$-galactosidase(EC 3.21.23) in Escherichia coli. Glyphosate has an effect on a turnover of D1 within photosystem II of thylakoid membrane. The dysfunction of D1 protein within light harvesting complex(LHC-II) seems to be a pleiotropic effect of glyphosate.