• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.525-531
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• 2014

In the present study, we investigated whether apigenin significantly affects tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced production and gene expression of MUC5AC mucin in airway epithelial cells. Confluent NCI-H292 cells were pretreated with apigenin for 30 min and then stimulated with TNF-${\alpha}$ for 24 h or the indicated periods. The MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription - polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Apigenin significantly inhibited MUC5AC mucin production and down-regulated MUC5AC gene expression induced by TNF-${\alpha}$ in NCI-H292 cells. To elucidate the action mechanism of apigenin, effect of apigenin on TNF-${\alpha}$-induced nuclear factor kappa B (NF-${\kappa}B$) signaling pathway was also investigated by western blot analysis. Apigenin inhibited NF-${\kappa}B$ activation induced by TNF-${\alpha}$. Inhibition of inhibitory kappa B kinase (IKK) by apigenin led to the suppression of inhibitory kappa B alpha ($I{\kappa}B{\alpha}$) phosphorylation and degradation, p65 nuclear translocation. This, in turn, led to the down-regulation of MUC5AC protein production in NCI-H292 cells. Apigenin also has an influence on upstream signaling of IKK because it inhibited the expression of adaptor protein, receptor interacting protein 1 (RIP1). These results suggest that apigenin can regulate the production and gene expression of mucin through regulating NF-${\kappa}B$ signaling pathway in airway epithelial cells.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.209-212
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• 2002

The heavy use of petroleum products in modern livings has brought ubiquitous environmental contaminants of aromatic compounds, which persist in aquatic and geo-environment without the substantial degradation. The persistence and accumulation of the aromatic compounds, which include xylene, phenol, toluene, phthalate, and so on are known to cause serious problems in our environments. Some of soil and aquatic microorganisms facilitate their growth by degrading aromatic compounds and utilizing degrading products as growth substrates, the biodegradation helps the reentry of carbons of aromatic compounds, preventing their accumulation in our environments. The metabolic studies on the degradation of aromatic compounds by microoganlsms were extensively carried out along with their genetic studies. A Rhodococcus sp. isolated in activated sludges has shown the excellent ability to grow on phenol as a sole carbon source. In the present study investigated a gene encoding phenol-degrading enzymes from a Rhodococcus sp.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.366-372
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• 2020

Since, side effects of antibiotics are frequently emphasized these days, their use is gradually diminishing, and alternative drugs are being developed. We have sought to reintroduce them as raw materials for human health as conventional 'weapons' that have been retired after their historical duties. In this study, we investigated the anti-inflammatory effects of lincomycin (LIN), on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Our findings show that LIN potently inhibited production of LPS-induced proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂), without cytotoxicity. Consistent with these findings, LIN strongly decreased protein expression levels of inducible NO synthase (iNOS) and cyclooxygenase (COX-2). Furthermore, LIN reduced pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. To further elucidate the mechanisms of these inhibitory effects of LIN, we studied LPS-induced IκB-α degradation, and mitogen-activated protein kinase (MAPK) phosphorylation. LIN suppressed downregulation of inhibitory κB (IκB-α) degradation, and the phosphorylation of the c-Jun N-terminal kinase (JNK) pathway. Based on these results, we suggest that LIN may be considered a potential candidate as an anti-inflammatory cosmetic or a medicine for human health.

• BMB Reports
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• v.42 no.1
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• pp.28-34
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• 2009

To understand the molecular mechanism underlying proline accumulation in Brassica napus, cDNAs encoding ${\Delta}^1$-pyrroline-5-carboxylate synthetase (BnP5CS), ornithine $\delta$-aminotransferase (BnOAT) and proline dehydrogenase (BnPDH) were isolated and characterized. Southern blot analysis of BnP5CSs in B. napus and its diploid ancestors suggested a gene loss may have occurred during evolution. The expression of BnP5CS1 and BnP5CS2 was induced, while the expression of BnPDH was inhibited under salt stress, ABA treatment and dehydration, prior to proline accumulation. The upregulation of BnOAT expression was only detected during prolonged severe osmotic stress. Our results indicate that stress-induced proline accumulation in B. napus results from the reciprocal action of activated biosynthesis and inhibited proline degradation. Whether the ornithine pathway is activated depends on the severity of stress. During development, proline content was high in reproductive organs and was accompanied by markedly high expression of BnP5CS and BnPDH, suggesting possible roles of proline during flower development.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.334-339
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• 2004

In this study, the effects of (-)-epigallocatechin-3-gallate (EGCG) and/or hinokitiol (${\beta}-thujaplicin$) on melanogenesis were investigated. Our results showed that both EGCG and hinokitiol significantly inhibited melanin synthesis in a concentration-dependent manner, and that their hypopigmenting effects were stronger than that of kojic acid, which is known to inhibit melanin formation in melanocytes and melanoma cells. Interestingly, EGCG did not show any additive hypopigmenting effect in combination with kojic acid, though EGCG did show a synergistic effect in combination with hinokitiol. Several reports indicate that the activation of extracellular signal-regulated kinase (ERK) induces microphthalmia-associated transcription factor (MITF) degradation. Accordingly, the effects of EGCG and hinokitiol on the ERK signaling pathway were examined. EGCG and hinokitiol induced neither ERK activation nor MITF degradation. On the other hand, both EGCG and hinokitiol reduced the protein levels of MITF and of tyrosinase, the rate limiting melanogenic enzyme, whereas kojic acid had no effect. In addition, hinokitiol strongly downregulated the activity of tyrosinase, whereas EGCG or kojic acid had only a little effect. These results show that both EGCG and hinokitiol reduce MITF production, and suggest that reduced tyrosinase activity by hinokitiol explains their synergistic effect on melanogenesis.

• YAKHAK HOEJI
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• v.51 no.5
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• pp.350-354
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• 2007

Taurine has been shown to be tissue-protective against oxidant-induced injury and is a powerful regulator of the immune system. However, there is no study on the antimelanogenic effect of taurine. In this study, we investigated the whitening effect of taurine in B16F10 mouse melanoma cells. Cell viability was measured by MTT assay. We examined melanin contents and tyrosinase activity according to time and concentration. Extracellular signal regulated kinase (ERK) is an important regulator of melanogenesis. It has been reported that activated ERK induced microphthalmia associated transcription factor (MITF) phosphorylation and its subsequent degradation and thus reduced melanin synthesis. In our B16F10 cell culture system, taurine led to decrease melanin contents by 21% at 48 hr. We then observed taurine effects on ERK-P, MITF and tyrosinase by Western blot. ERK was activated at 18 hr and 24 hr, whereas MITF reduced. We could not observe any differences in the levels of tyrosinase. These results suggested that taurine inhibited melanogenesis by ERK signal pathway via MITF degradation. We expect that taurine has potential skin whitening agents in cosmetics.

• Nuclear Engineering and Technology
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• v.43 no.5
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• pp.405-412
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• 2011

Used nuclear fuel will likely be stored dry for extended periods of time in the USA. Until a final disposition pathway is chosen, the storage periods will almost definitely be longer than were originally intended. The ability of the important-tosafety structures, systems, and components (SSCs) to continue to meet storage and transport safety functions over extended times must be determined. It must be assured that there is no significant degradation of the fuel or dry cask storage systems. Also, it is projected that the maximum discharge burnups of the used nuclear fuel will increase. Thus, it is necessary to obtain data on high burnup fuel to demonstrate that the used nuclear fuel remains intact after extended storage. An evaluation was performed to determine the conditions that may lead to failure of dry storage SSCs. This paper documents the initial technical gap analysis performed to identify data and modeling needs to develop the desired technical bases to ensure the safety functions of dry stored fuel.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.83-85
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• 2019

Pseudomonas sp. PAMC 29040 was isolated from a maritime tundra soil in Antarctica for its ability to degrade lignin and subsequently confirmed to be able to depolymerize heterogeneous humic substance (HS), a main component of soil organic matter. The draft genome sequences of PAMC 29040 were analyzed to discover the putative genes for depolymerization of polymeric HS (e.g., dye-decolorizing peroxidase) and catabolic degradation of HS-derived small aromatics (e.g., vanillate O-demethylase). The information on degradative genes will be used to finally propose the HS degradation pathway(s) of soil bacteria inhabiting cold environments.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.195-200
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• 2005

Comamonas sp. strain DJ-12 is a bacterial isolate capable of degrading of 4-chlorobiphenyl (4CB) as a carbon and energy source. The degradation pathway was characterized as being conducted by consecutive reactions of the meta-degradation of 4CB, hydrolytic dechlorination of 4-chlorobenzoate (4CBA), hydroxylation of 4-hydroxybenzoate, and meta-degradation of protocatechuate to product TCA metabolites. The 6.8 kb fragment from the chromosomal DNA of Comamonas sp. strain DJ-12 included the genes encoding for the meta-degradation of PCA; the genes of protocatechuate 4,5-dioxygenase alpha and beta subunits (pmcA and pmcB), 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase (pmcC), 2-pyrone-4,6-dicarboxylate hydrolase (pmcD), 4-oxalomesaconate (OMA) hydratase(pmcE), 4-oxalocitramalate (OCM) aldolase (pmcF), and transporter gene (pmcT). They were organized in the order of pmcT-pmcE-pmcF-pmcD-pmcA-pmcB-pmcC. The amino acid sequences deduced from the nucleotide sequences of pmcABCDEFT genes from Comamonas sp. strain DJ-12 exhibited 94 to $98\%$ homologies with those of Comamonas testosteroni BR6020 and Pseudomonas ochraceae NGJ1, but only 52 to $74\%$ with homologies Sphingomonas paucimobilis SYK-6, Sphingomonas sp. LB126, and Arthrobacter keyseri 12B.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.49-56
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• 2003

The strain Ralstonia eutopha JMP134 (formerly Alcaligenes eutrophus JMP134) can degrade trichloroethylene(TCE) through a chromosomal phenol-dependent pathway. The phenol hydroxylase was previously found to be a single responsible enzyme for TEC degradation. Here, we demonstrate that a recombinant bacterium, R. eutopha AEK301, one of Tn5-induced mutants of JMP134 containing a recombinant plasmid pYK3011, degrades TCE in the absence of inducer, phenol and in the presence of various carbon sources. Complete removal of TCE ($50{\mu}M$) was observed in minimal medium containing only 0.05% ethanol as a carbon source within 24 hours. The bacterium removed $200{\mu}M$ of TCE to below detectable level within two days under non-selective pressure. When TCE concentration was increased up to $400{\mu}M$, the degradation had been continued until two days, then ceased with removal of 70% of detectable TCE.