• International Journal of Oral Biology
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• 제43권3호
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• pp.161-169
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• 2018

We previously demonstrated that epidermal growth factor (EGF) enhances cell migration and invasion of breast cancer cells in a SMAD ubiquitination regulatory factor 1 (SMURF1)-dependent manner and that SMURF1 induces degradation of ${\beta}-catenin$ in C2C12 cells. However, the relationship between EGF-induced SMURF1 and ${\beta}-catenin$ expression in breast cancer cells remains unclear. So, we investigated if EGF and SMURF1 regulate ${\beta}-catenin$ expression in MDAMB231 human breast cancer cells. When MDAMB231 cells were incubated with EGF for 24, 48, and 72 hours, EGF significantly increased expression levels of SMURF1 mRNA and protein while suppressing expression levels of ${\beta}-catenin$ mRNA and protein. Overexpression of SMURF1 downregulated ${\beta}-catenin$ mRNA and protein, whereas knockdown of SMURF1 increased ${\beta}-catenin$ expression and blocked EGF-induced ${\beta}-catenin$ downregulation. Knockdown of ${\beta}-catenin$ enhanced cell migration and invasion of MDAMB231 cells, while ${\beta}-catenin$ overexpression suppressed EGF-induced cell migration and invasion. Furthermore, knockdown of ${\beta}-catenin$ enhanced vimentin expression and decreased cytokeratin expression, whereas ${\beta}-catenin$ overexpression decreased vimentin expression and increased cytokeratin expression. These results suggest that EGF downregulates ${\beta}-catenin$ in a SMURF1-dependent manner and that ${\beta}-catenin$ downregulation contributes to EGF-induced cell migration and invasion in MDAMB breast cancer cells.

• Molecules and Cells
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• 제44권10호
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• pp.710-722
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• 2021

Hypoxia, or low oxygen tension, is a hallmark of the tumor microenvironment. The hypoxia-inducible factor-1α (HIF-1α) subunit plays a critical role in the adaptive cellular response of hypoxic tumor cells to low oxygen tension by activating gene-expression programs that control cancer cell metabolism, angiogenesis, and therapy resistance. Phosphorylation is involved in the stabilization and regulation of HIF-1α transcriptional activity. HIF-1α is activated by several factors, including the mitogen-activated protein kinase (MAPK) superfamily. MAPK phosphatase 3 (MKP-3) is a cytoplasmic dual-specificity phosphatase specific for extracellular signal-regulated kinase 1/2 (Erk1/2). Recent evidence indicates that hypoxia increases the endogenous levels of both MKP-3 mRNA and protein. However, its role in the response of cells to hypoxia is poorly understood. Herein, we demonstrated that small-interfering RNA (siRNA)-mediated knockdown of MKP-3 enhanced HIF-1α (not HIF-2α) levels. Conversely, MKP-3 overexpression suppressed HIF-1α (not HIF-2α) levels, as well as the expression levels of hypoxia-responsive genes (LDHA, CA9, GLUT-1, and VEGF), in hypoxic colon cancer cells. These findings indicated that MKP-3, induced by HIF-1α in hypoxia, negatively regulates HIF-1α protein levels and hypoxia-responsive genes. However, we also found that long-term hypoxia (>12 h) induced proteasomal degradation of MKP-3 in a lactic acid-dependent manner. Taken together, MKP-3 expression is modulated by the hypoxic conditions prevailing in colon cancer, and plays a role in cellular adaptation to tumor hypoxia and tumor progression. Thus, MKP-3 may serve as a potential therapeutic target for colon cancer treatment.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1349-1360
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• 2019

Chronic exposure to ultraviolet (UV) radiation, regarded as a major cause of extrinsic aging or photoaging characterized by wrinkle formation and skin dehydration, exerts adverse effects on skin by causing the overproduction of reactive oxygen species. Agastache rugosa Kuntze, known as Korean mint, possesses a wide spectrum of biological properties including anti-oxidation, anti-inflammation, and anti-atherosclerosis. Previous studies have reported that A. rugosa protected human keratinocytes against UVB irradiation by restoring the anti-oxidant defense system. However, the anti-photoaging effect of A. rugosa extract (ARE) in animal models has not yet been evaluated. ARE was orally administered to hairless mice at doses of 100 or 250 mg/kg/day along with UVB exposure for 12 weeks. ARE histologically improved UVB-induced wrinkle formation, epidermal thickening, erythema, and hyperpigmentation. In addition, ARE recovered skin moisture by improving skin hydration and transepidermal water loss (TEWL). Along with this, ARE increased hyaluronic acid levels by upregulating HA synthase genes. ARE markedly increased the density of collagen and the amounts of hydroxypoline via two pathways. First, ARE significantly downregulated the mRNA expression of matrix metalloproteinases responsible for collagen degradation by inactivating the mitogen-activated protein kinase/activator protein 1 pathway. Second, ARE stimulated the transforming growth factor beta/Smad signaling, consequently raising the mRNA levels of collagen-related genes. In addition, ARE not only increased the mRNA expression of anti-oxidant enzymes but also decreased inflammatory cytokines by blocking the protein expression of nuclear factor kappa B. Collectively, our findings suggest that A. rugosa may be a potential preventive and therapeutic agent for photoaging.

• 대한본초학회지
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• 제24권4호
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• pp.181-188
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• 2009

Objectives : In this study, we investigated the effect of methyl gallate of Paeonia suffruticosa(Moutan Cortex Radicis) on inflammatory response in activated macrophages. Methods : RAW264.7 cells were incubated with different concentrations of methyl gallate of Paeonia suffruticosa for 30 min and then stimulated with or without LPS at indicated times. Cell toxicity was determined by MTT assay. The concentrations of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$) and inflammatory cytokines (TNF-$\alpha$, IL-6) were measured in culture medium by Griess assay, enzyme-immuno assay, and ELISA, respectively. The expressions of iNOS, COX-2 and cytokine mRNA and protein were determined by RT-PCR and Western blot, respectively. The $I{\kappa}-B{\alpha}$ degradation in cytosol and NF-${\kappa}B$ p65 translocation into nuclear of the cells were determined by Western blot. Results : Methyl gallate was significantly inhibited LPS-induced production of NO and PGE2 in RAW264.7 cells. Methyl gallate was also suppressed LPS-induced expression of iNOS and COX-2 mRNA and protein in the cells. Methyl gallate was inhibited LPS-induced production of TNF-$\alpha$ and IL-6 via suppression of their mRNA expressions. Methyl gallate blocked the NF-${\kappa}B$ pathway in LPS-stimulated RAW264.7 cells. Conclusions : This study suggests that methyl gallate of Paeonia suffruticosa may have an antiinflammatory property through suppressing inflammatory mediator production in activated macrophages.

• Journal of Photoscience
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• 제9권2호
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• pp.332-334
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• 2002

We examined the effects of supplementary ultraviolet-B (UV-B) radiation on the changes in synthesis and degradation of ribulose-I, 5-biphosphate carboxylase /oxygenase (Rubisco) and light-harvesting chlorophyll a/b binding protein of PSII (LHCII), as well as mRNA levels for small and large subunits of Rubisco (rbcS and rbcL, respectively) and LHCII (cab) with leaf age in UV-sensitive rice (Norin I) and UV-resistant rice (Sasanishiki). Both Rubisco and LHCII were actively synthesized until the leaf had fully expanded, and then decreased with leaf age. Synthesis of Rubisco, but not LHCII, was significantly suppressed by UV-B in Norin 1. The degradation of Rubisco was enhanced by UV-B around the time of the leaf maturation in the two cultivars. The levels of rbcS and rbcL were reduced by UV-B at the early leaf stages after emergence in both cultivars. The level of cab was first present at the highest level in the two cultivars, but drastically decreased due to UV-B treatment immediately after leaf emergence in Norin 1. It was proved that synthesis and degradation of Rubisco and LHCII greatly changed with leaf age: Rubisco synthesis was significantly suppressed by supplementary UV-B radiation at the transcription step during the early leaf stages. It was also suggested that the difference between the two rice cultivars in sensitivity to UV-B in the synthesis of Rubisco might be due to the specific suppression not only after transcription but also at transcription.

• Parasites, Hosts and Diseases
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• 제52권5호
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• pp.459-469
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• 2014

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-${\kappa}B$ (p65) in Caco-2 cells. However, $I{\kappa}B$, an inhibitor of NF-${\kappa}B$, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-${\kappa}B$ was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-${\kappa}B$ and STATs in colonic epithelial cells, which ultimately accelerates cell death.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1617-1626
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• 2013

The Bacterial community structure and its complexity of the enrichment culture during the isolation and screening of imidacloprid-degrading strain were studied using denaturating gradient gel electrophoresis analysis. The dominant bacteria in the original tea rhizosphere soil were uncultured bacteria, Rhizobium sp., Sinorhizobium, Ochrobactrum sp., Alcaligenes, Bacillus sp., Bacterium, Klebsiella sp., and Ensifer adhaerens. The bacterial community structure was altered extensively and its complexity reduced during the enrichment process, and four culturable bacteria, Ochrobactrum sp., Rhizobium sp., Geobacillus stearothermophilus, and Alcaligenes faecalis, remained in the final enrichment. Only one indigenous strain, BCL-1, with imidacloprid-degrading potential, was isolated from the sixth enrichment culture. This isolate was a gram-negative rod-shaped bacterium and identified as the genus Ochrobactrum based on its morphological, physiological, and biochemical properties and its 16S rRNA gene sequence. The degradation test showed that approximately 67.67% of the imidacloprid (50 mg/l) was degraded within 48 h by strain BCL-1. The optimum conditions for degradation were a pH of 8 and $30^{\circ}C$. The simulation of imidacloprid bioremediation by strain BCL-1 in soil demonstrated that the best performance in situ (tea soil) resulted in the degradation of 92.44% of the imidacloprid (100 mg/g) within 20 days, which was better than those observed in the ex situ simulations that were 64.66% (cabbage soil), 41.15% (potato soil), and 54.15% (tomato soil).

• Food Science and Biotechnology
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• 제15권6호
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• pp.975-979
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• 2006

The extracts of Oenanthe javanica were evaluated for their effects on the expression of cyclooxygenase-2 (COX-2), which is mediated by the translocation of the p65 subunit into the nucleus. Fractions of ethyl acetate and chloroform from 80% ethanol extracts of O. javanica exhibited inhibitory effects on the secretion of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) from lipopolysaccharide (LPS)-stimulated peritoneal macrophages; however, the aqueous- and hexane-fractions showed no significant effect. The ethyl acetate- and chloroform-fractions also reduced the COX-2 enzyme levels after 24-hr treatment. RT-PCR showed that the mRNA levels of COX-2 decreased following treatment with these fractions, suggesting that COX-2 expression is transcriptionally regulated by these extracts. We examined the effects of the chloroform- and ethyl acetate-fractions on the cytosolic activation of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$, p65 subunit) and on the degradation of inhibitor-${\kappa}B{\alpha}$ ($I-{\kappa}B{\alpha}$) in order to determine the mechanism of COX-2 regulation. The LPS-stimulated activation of the p65 subunit was significantly blocked upon the addition of $50\;{\mu}g/mL$ of these fractions, and the cytosolic $I-{\kappa}B{\alpha}$ degradation process was simultaneously inhibited. These findings suggest that the inhibition of COX-2 expression by the ethyl acetate-and chloroform-fractions may result from the inhibition of p65 translocation by blocking the degradation of $I-{\kappa}B{\alpha}$; this may be the mechanistic basis for the anti-inflammatory effects of O. javanica.

• 미생물학회지
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• 제44권4호
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• pp.311-316
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• 2008

BTEX 분해능을 가진 BJ10세균을 이용하여 호기조건에서 toluene 첨가 시 tetrachloroethylene (PCE) 분해에 관한 연구를 수행하였다. BJ10은 형태학적 특징, 생리 생화학적 특징, 16S rRNA 염기서열 분석 및 지방산 분석 결과에 따라 Pseudomonas putida로 동정되었다. BJ10의 PCE 저농도 5 mg/L에서 PCE 분해 실험 결과(toluene 첨가 기질 농도 50mg/L, 균초기 접종농도 1.0g/L, 온도 $30^{\circ}C$, pH7 그리고 DO $3.0{\sim}4.2\;mg/L$), 10일간 52.8%의 분해 효율을 보였으며, PCE 분해 속도는 5.9 nmol/hr로 나타났다. 또한 BJ10의 PCE 고농도 100 mg/L에서 PCE 분해 실험 결과 (toluene 첨가 기질 농도 50 mg/L, 균 초기 접종 농도 1.0 g/L, 온도 $30^{\circ}C$, pH 7 그리고 DO $3.0{\sim}4.2\;mg/L$), 10일간 20.3%의 분해 효율을 보였으며, PCE 분해 속도는 46.0 nmol/hr로 나타났다. Toluene 첨가 농도에 따른 PCE 분해 효율 증감 효과를 알아보기 위하여, 동일한 배양 조건하에 10 mg/L의 PCE에 toluene ($5{\sim}200\;mg/L$)을 첨가하여 분해 실험을 실시한 결과, toluene 200 mg/L 첨가시 10일간 57.0%의 PCE가 분해되어 가장 높은 제거 효율을 보였다. 또한 PCE 5.5 mg/L(총 7.6 mg/L)를 추가적으로 주입하여 동일조건하에서 PCE 분해를 확인하였으며 결과적으로 8일 동안 63.0%의 PCE가 분해되었다. 이 때의 PCE 분해 속도는 13.5 nmol/hr로 초기의 분해속도(8.1 nmol/hr)보다 증가되었다.

• KSBB Journal
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• 제16권1호
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• pp.1-10
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• 2001

Escherichia coli has been used as an expression work horse for foreign genes. This article summarized recent development in genetic engineering techniques for overproduction of medical proteins and industrial enzymes. Special emphasis was placed upon research activities concerning folding and refolding of inclusion bodies at genetic and fermentation levels. Plasmid and mRNA stabilization, development of strong inducible promoters, modification of translational elements and reduction of rpoteolytic degradation were carried out to elevate an expression level of a target protein. Optimization of culture conditions, improvement of denaturation and renaturation steps and coexpression of molecular chaperones or foldase were accomplished to produce active proteins in soluble form. Fusion protein systems with selective separation and surface display technology were also performed in an effort to make the E. coli expression system more effective and versatile.