• Molecules and Cells
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• v.27 no.1
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• pp.75-81
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• 2009

The Arabidopsis gene AtLEC (At3g15356) gene encodes a putative 30-kDa protein with a legume lectin-like domain. Likely to classic legume lectin family of genes, AtLEC is expressed in rosette leaves, primary inflorescences, and roots, as observed in Northern blot analysis. The accumulation of AtLEC transcript is induced very rapidly, within 30 min, by chitin, a fungal wall-derived oligosaccharide elictor of the plant defense response. Transgenic Arabidopsis carrying an AtLEC promoter-driven ${\beta}$-glucuronidase (GUS) construct exhibited GUS activity in the leaf veins, secondary inflorescences, carpel heads, and silique receptacles, in which no expression could be seen in Northern blot analysis. This observation suggests that AtLEC expression is induced transiently and locally during developmental processes in the absence of an external signal such as chitin. In addition, mechanically wounded sites showed strong GUS activity, indicating that the AtLEC promoter responds to jasmonate. Indeed, methyl jasmonate and ethylene exposure induced AtLEC expression within 3-6 h. Thus, the gene appears to play a role in the jasmonate-/ethylene-responsive, in addition to the chitin-elicited, defense responses. However, chitin-induced AtLEC expression was also observed in jasmonate-insensitive (coi1) and ethylene-insensitive (etr1-1) Arabidopsis mutants. Thus, it appears that chitin promotes AtLEC expression via a jasmonate- and/or ethylene-independent pathway.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.414-419
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• 2014

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that regulate cell-matrix composition and are also involved in processing various bioactive molecules such as cell-surface receptors, chemokines, and cytokines. Our group recently reported that MMP-3, -8, and -9 are upregulated during microglial activation and play a role as proinflammatory mediators (Lee et al., 2010, 2014). In particular, we demonstrated that MMP-8 has tumor necrosis factor alpha (TNF-${\alpha}$)-converting enzyme (TACE) activity by cleaving the prodomain of TNF-${\alpha}$ and that inhibition of MMP-8 inhibits TACE activity. The present study was undertaken to compare the effect of MMP-8 inhibitor (M8I) with those of inhibitors of other MMPs, such as MMP-3 (NNGH) or MMP-9 (M9I), in their regulation of TNF-${\alpha}$ activity. We found that the MMP inhibitors suppressed TNF-${\alpha}$ secretion from lipopolysaccharide (LPS)-stimulated BV2 microglial cells in an order of efficacy: M8I>NNGH>M9I. In addition, MMP inhibitors suppressed the activity of recombinant TACE protein in the same efficacy order as that of TNF-${\alpha}$ inhibition (M8I>NNGH>M9I), proving a direct correlation between TACE activity and TNF-${\alpha}$ secretion. A subsequent pro-TNF-${\alpha}$ cleavage assay revealed that both MMP-3 and MMP-9 cleave a prodomain of TNF-${\alpha}$, suggesting that MMP-3 and MMP-9 also have TACE activity. However, the number and position of cleavage sites varied between MMP-3, -8, and -9. Collectively, the concurrent inhibition of MMP and TACE by NNGH, M8I, or M9I may contribute to their strong anti-inflammatory and neuroprotective effects.

• Molecules and Cells
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• v.19 no.3
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• pp.418-427
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• 2005

When inoculated into sensitive tobacco Xanthi-nn plants, the crucifer and garlic-infecting Tobacco mosaic virus (TMV-Cg) induces local necrotic lesions that resemble those seen in the hypersensitive response (HR) of resistant tobacco plants. However, unlike these, tobacco Xanthi-nn plants do not become resistant to infection and the virus spreads systemically causing a severe disease characterized by necrotic lesions throughout the plant. To identify the viral protein that elicits this necrotic response, we used a set of hybrid viruses constructed by combination of TMV-Cg and the tobacco mosaic virus strain U1 (TMV-U1). In this study we present evidence that the coat protein of TMV-Cg (CPCg) is the elicitor of the necrotic response in tobacco Xanthi-nn plants. Local and systemic necrotic lesions induced by TMV-Cg and by the hybrid U1-CPCg -that carries CPCg in a TMV-U1 context- are characterized by cell death and by the presence of autoflorescent phenolic compounds and $H_2O_2$, just like the HR lesions. In addition, defense-related genes and detoxifying genes are induced in tobacco Xanthi-nn plants after TMV-Cg and U1-CPCg inoculation. We postulate that in our system, CPCg is recognized by sensitive tobacco plants that mount an incomplete defense response. We call this an HR-like since it is not enough to induce plant resistance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.2
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• pp.109-115
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• 2023

In this paper, we demonstrated the orientation characteristics of liquid crystals using UV-treated FSAM as alignment layer. Moreover we confirmed the FSAM properties before and after UV treatment on indium tin oxide (ITO) glass substrates using physicochemical analysis. The hydrophobic property of the FSAM surface is change to hydrophilic through UV treatment. After UV treatment the LC molecules also were uniformly and horizontally aligned on the FSAM surfaces and the pretilt angle was obviously changed 90° degrees to 0° degrees. EO characteristic of TN cell which was fabricated with UV-treated FSAM was faster response time compare to conventional PI layer. The FSAM before and after UV treatment has a superior application potential as the LC alignment layer for LCD, potentially replacing the conventional polyimide layer.

• Analytical Science and Technology
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• v.30 no.6
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• pp.405-410
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• 2017

High energetic materials (HEMs) have been used in fuels, civil engineering and architecture as well as military purposes such as explosives and propellants. The essential process for the development of new energetic compounds is to accurately calculate its detonation performances. The most typical equation for calculating the explosive performance is the Kamlet-Jacobs (K-J) equation. In the K-J equation, the parameter such as the number of moles of gaseous products at the explosion, the average molar mass of gas products, and the explosion heat greatly affect the explosion performance. These depend on the product composition for the detonation reaction. In this study, detonation products of 65 high energetic molecules (HEMs) were calculated from the various rules such as Kamlet-Jacobs, Kistiakowsky-Wilson, modified Kistiakowsky-Wilson, Springall-Roberts rules to calculate more accurate detonation velocity (Dv). In addition, they were applied to five kinds of detonation velocity equations proposed by K-J, Rothstein, Xiong, Stine and Keshavarz. The mean absolute error and root mean square error of HEMs were obtained from experimental and calculated velocity value for each method. The K-J and Xiong equation that is slightly complex showed a lower mean absolute error than the simple Rothstein and Keshavarz equation. When the mod-KW rule was applied to the Xiong equation, the detonation velocities were the most accurate. This study compared the various method of calculating the detonation velocity of HEMs to obtain accurate HEMs performance.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.770-780
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• 2002

The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airborne enemies.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.248-256
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• 1998

We had already reported that we purified N-${\beta}$-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine (5-S-GAD), a novel antibacterial substance from the immunized adult Sarcoph aga peregrina (Flesh fly). We found that the antibacterial activity of synthetic 5-S-GAD is equal to that of authentic 5-S-GAD without a specificity of antibacterial activity against Gram positive and Gram negative. Significant synergism was detected between 5-S-GAD and streptomycin against streptomycin resistant strain E.coli K12 594. It has an antitumor activity against several tumor cell lines at a concentration of $100{\mu}M$. However, no cytotoxic activity against murine macrophage was detected at a concentration of $500{\mu}M$. Furthermore, haemolytic activity against sheep erythrocytes was not detected at the same concentration. We suggest that the S-conjugation of glutathion with dihydroxyphenylalanine might be important to increase antibacterial activity of dihydroxyphenylalanme.

• Molecules and Cells
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• v.27 no.1
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• pp.5-14
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• 2009

The availability of effective vaccines has had the most profound positive effect on improving the quality of public health by preventing infectious diseases. Despite many successful vaccines, there are still old and new emerging pathogens against which there is no vaccine available. A better understanding of how vaccines work for providing protection will help to improve current vaccines as well as to develop effective vaccines against pathogens for which we do not have a proper means to control. Recent studies have focused on innate immunity as the first line of host defense and its role in inducing adaptive immunity; such studies have been an intense area of research, which will reveal the immunological mechanisms how vaccines work for protection. Toll-like receptors (TLRs), a family of receptors for pathogen-associated molecular patterns on cells of the innate immune system, play a critical role in detecting and responding to microbial infections. Importantly, the innate immune system modulates the quantity and quality of long-term T and B cell memory and protective immune responses to pathogens. Limited studies suggest that vaccines which mimic natural infection and/or the structure of pathogens seem to be effective in inducing long-term protective immunity. A better understanding of the similarities and differences of the molecular and cellular events in host responses to vaccination and pathogen infection would enable the rationale for design of novel preventive measures against many challenging pathogens.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.422-431
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• 2016

Plants utilize cytochrome P450, a large superfamily of heme-containing mono-oxygenases, in the synthesis of lignins, UV protectants, pigments, defense compounds, fatty acids, hormones, and signaling molecules. Despite the overwhelming assortment of rice P450 accession numbers in the database, their functional studies are lacking. So far, there is no evidence involving rice P450 in disease immunity. Most of our understanding has been based on other plant systems that are mostly dicot. In this study, we isolated the cytochrome P450 (OsCYP71) in rice, and screened the gene using gain-of-function technique. The full-length cDNA of OsCYP71 was constitutively overexpressed using the 35S promoter. We then explored the functions of OsCYP71 in the rice - Xanthomonas oryzae pv. oryzae pathosystem. Using the gene expression assays, we demonstrate the interesting correlation of PR gene activation and the magnitude of resistance in P450-mediated immunity.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.103-118
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• 2008

Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.