• Title/Summary/Keyword: repressing

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A $G_{4}$ Sequence within PHR1 Promoter Acts as a Gate for Cross-Talks between Damage-Signaling Pathway and Multi-Stress Response

  • Jang, Yeun-Kyu;Kim, Eun-Mi;Park, Sang-Dai
    • Animal cells and systems
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    • v.6 no.3
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    • pp.271-275
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    • 2002
  • Rph1 and Gisl are damage-responsive repressors involved in PHR1 expression. They have two $C_{2}$H/ sub 2/ zinc finger motifs as putative DNA binding domains and N-terminal conserved domain with unknown function. They are also found in the human retinoblastoma binding protein 2 and the mouse jumonji- encoded protein. The repressors are able to bind to A $G_{4}$ sequence within a 39-bp sequence called upstream repressing sequence of PHR1 promoter (UR $S_{PHR1}$) responsible for the damage-response of PHR1. We report here that Rph1 is predominantly localized in the nucleus as examined by fluorescence microscopic analysis with GFP-Rph1 fusion protein. On the basis of the fact that the A $G_{4}$ sequence that is recognized by Rph1 and Gisl is also recognized by Msn2 and Msn4 in a process of stress response, we a1so tried to examine the in vivo function of A $G_{4}$ and the role of Msn2 and Msn4 in PHR1 expression. Our results demonstrate that Msn2 and Msn4 are actually required for the basal transcription of PHR1 expression but not for its damage induction. When A $G_{4}$ sequence was inserted into the minimal promoter of the cyc1-LacZ reporter, the increased LacZ expression was observed indicating its involvement in transcriptional activation. The data suggest that the A $G_{4}$ is primarily required for basal transcriptional activation of PHR1 or CYC1 promoter through the possible involvement of Msn2 and Msn4. However, since the A $G_{4}$ is also involved in the repression of PHR1 via Rphl and Gisl, it is proposed that A $G_{4}$ functions as either URS or upstream activating sequence (UAS) depending on the promoter context.t.

Mechanical Properties of Zirconia Reinforced Glass-Ceramic (지르코니아 강화형 Glass-Ceramic의 기계적 성질)

  • Park, Eun-Eui;Dong, Jin-Keun;Lee, Hae-Hyoung;Song, Ki-Chang;Oh, Sang-Chun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.17 no.3
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    • pp.199-204
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    • 2001
  • This study was to investigate the reused possibility of zirconia reinforced glass-ceramic(IPS Empress Cosmo ceramic) with sprue button in the flexure strength and fracture toughness. 40 disk-shaped ceramic specimens (20 specimens: as-pressed material; 20 specimens: reused material) with approximately 1.7 mm thickness and 15 mm diameter were prepared by "lost wax" technique. The remnants(sprue buttons) were used for repressing. The surface treatments for the discs were gradually abraded with 320, 800, 1200, and 2000 grit SiC sandpaper. The specimens were evaluated their flexure strength with the biaxial flexure jig(ball-on-three balls) and their fracture toughness with Vickers Indentation-microfracture test. The Weibull moduli were calculated for biaxial flexural strength. The mean flexure strength and fracture toughness of each group were $122.2{\pm}18.3MPa$, $1.00{\pm}0.09MPa{\cdot}m^{0.5}$ (as-pressed ceramics), and $122.2{\pm}20.3MPa$, $1.01{\pm}0.10MPa{\cdot}m^{0.5}$ (reused ceramics). There were no significant differences in the strength and the fracture toughness between the as-pressed and the reused IPS Empress Cosmo ceramic (P>0.05). This implied zirconia reinforced glass-ceramic(IPS Empress Cosmo ceramic) could be used one more time by reusing of sprue button in the flexure strength and fracture toughness.

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Genome-wide Expression Profiling of Piperine and Piper nigrum Linne (호초(胡椒)와 Piperine에 의한 총체적 유전자 발현 비교)

  • Jo, Eun-Young;Jeong, Ji-Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.5
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    • pp.831-836
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    • 2010
  • In addition to spice, black pepper (Piper nigrum Linne : PnL) has been used as herbal medicine because of its function in anti-oxidation, anti-inflammation, and anti-carcinogenesis. Recently, it has been reported that piperine, a component of PnL, inhibits adipocyte differentiation by repressing various adipogenic gene expressions. In this study, we determined whether piperine is a major constituent of PnL that confers the anti-adipogenic activity at whole genome level. Differentiation of 3T3-L1 pre-adipocytes was induced in presence of PnL extract or piperine. To compare genes that are regulated by PnL extract or piperine, we performed expression profiling using microarrays (Agilent Mouse 44k 4plex). RNA samples were labeled with Cy3 and Cy5, respectively. Labeled samples were hybridized to the microarrays. Results were filtered and cut off set p<0.05. Genes exhibiting significant differences in expression level were classified into Gene Ontology (GO)-based functional categories (http://www.geneontology.org) and KEGG (http://www.genome.jp/kegg/). Extract of PnL and its component piperine reduced lipid accumulation in 3T3-L1 cells during adipogenesis. Such anti-adipogenic activity appears to result from down-regulation of transcription factor genes involved in adipogenesis, and other genes involved in fatty acid synthesis, transport, triglyceride synthesis, and carbohydrate metabolism. These genome-wide studies lead to conclude that piperine, as a critical component of PnL, plays common role with PnL in anti-adipogenesis.

MiR-454 Prompts Cell Proliferation of Human Colorectal Cancer Cells by Repressing CYLD Expression

  • Liang, Hong-Liang;Hu, Ai-Ping;Li, Sen-Lin;Xie, Jia-Ping;Ma, Qing-Zhu;Liu, Ji-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.6
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    • pp.2397-2402
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    • 2015
  • Previous studies have shown that miR-454 plays an important role in a variety of biological processes in various human cancer cells. However, the underlying mechanisms of this microRNA in colorectal cancer (CRC) cells remain largely unknown. In the present study, we investigated the miR-454 role in CRC cell proliferation. We found that miR-454 expression is markedly upregulated in CRC tissues and CRC cells compared with the matched tumor adjacent tissues and the FHC normal colonic cell line. Ectopic expression of miR-454 promoted the proliferation and anchorage-independent growth of CRC cells, whereas inhibition of miR-454 reduced this effect. Bioinformatics analysis further revealed cylindromatosis (CYLD), a putative tumor suppressor as a potential target of miR-454. Data from luciferase reporter assays showed that miR-454 directly binds to the 3'-untranslated region (3'-UTR) of CYLD mRNA and repressed expression at both transcriptional and translational levels. In functional assays, CYLD-silenced in miR-454-in-transfected SW480 cells have positive effect to promote cell proliferation, suggesting that direct CYLD downregulation is required for miR-454-induced CRC cell proliferation. In sum, our data provide compelling evidence that miR-454 functions as an onco-miRNA, playing a crucial role in the promoting cell proliferation in CRC, and its oncogenic effect is mediated chiefly through direct suppression of CYLD expression.

Exclusion and Inclusion of Deathscape : An Investigation on the Intervention of Institutional Discourses in Modern Korea (죽음경관의 배제와 포섭: 근대 한국의 제도적 담론의 개입에 대한 고찰)

  • Seo, Il Woong;Park, Kyonghwan
    • Journal of the Korean association of regional geographers
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    • v.20 no.4
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    • pp.425-443
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    • 2014
  • The subjects of this research are two-folds. First, it investigates the ways in which previous geographic studies have approached to human death and its spatial representations through various theoretical frames. It is found that necrogeographies on cemetery have changed into those studies focusing on the social and spatial contexts in which deathscapes are represented. Second, this research analyzes what institutional discourses have intervened in excluding or including modern deathscapes in Korea. Some discourses socio-spatially excluded specific (undesirable) deathscape, and they mostly depended on employing such terms as 'Yeoido' and 'illegal, luxury, or deserted cemeteries'. On the contrary, other discourses employed such terms as 'developed country', 'Unified-Silla Dynasty', and 'NIMBY', and they introduced new (desirable) types of deathscapes such as cremation. This paper conclusively argues that these discourses engendered 'truth effect' so as to introduce and promote specific deathscapes while repressing pre-modern (or conventional) deasthscapes and concealing discursive contradictions.

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Anti-oxidative properties of ginseng (인삼의 항산화 작용)

  • Kim, Eun-Hye;Rhee, Dong-Kwon
    • Journal of Ginseng Research
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    • v.33 no.1
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    • pp.1-7
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    • 2009
  • Clinical and animal studies have shown that free radical overload is an important cause for a variety of diseases. Although ginseng has been recognized as antioxidant, how it modulates anti-oxidative process at the molecular level remains unknown. Free radical production is induced by tumor necrosis factor-$\alpha$ (TNF-$\alpha$) under the stress condition, and (TNF-$\alpha$) release is activated by TNF-$\alpha$-converting enzyme (TACE). Since TACE inhibitor is also well known for anti-inflammatory agent, ginseng seems to show anti-oxidative activity by repressing TACE pathway. Further studies on signal transduction would be warranted to elucidate molecular action mechanisms of ginseng on anti-oxidation and anti-inflammation.

Effect of Jungmanbunso-hwan Extract on HepG2 Cell Model of Nonalcoholic Fatty Liver Disease Caused by Palmitate (중만분소환 추출물이 Palmitate로 유발된 비알코올성 지방간 HepG2 cell 모델에 미치는 영향)

  • Lee, Ji-won;Choi, Chang-won;Jeon, Sang-yun;Han, Chang-woo;Ha, Ye-jin
    • The Journal of Internal Korean Medicine
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    • v.37 no.3
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    • pp.442-452
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    • 2016
  • Objectives: This study was performed to investigate the anti-lipogenic effect and the mechanism of Jungmanbunso-hwan extract (JMBSH) on a cellular model of non-alcoholic fatty liver disease (NAFLD) caused by palmitate in HepG2 cells.Methods: The JMBSH was prepared, andHepG2 cells were treated with various concentrations of JMBSH in order to perform an MTT assay. The HepG2 cells were cultivated in palmitate-containing media with or without extract of JMBSH. The intracellular lipid content in the HepG2 cells was examined. The effects of JMBSH on sterol regulatory element-binding transcription factor-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), and AMP-activated protein kinase (AMPK) activation in HepG2 cells were measured.Results: JMBSH did not reduce HepG2 cell viability under 1,000 μg/mL. JMBSH considerably decreased intracellular lipid accumulation caused by palmitate in HepG2 cells. JMBSH repressed expression of SREBP-1c, which mediates the induction of lipogenic genes (ACC, FAS, and SCD-1). JMBSH also activated AMPK, which plays animportant role in the regulation of hepatic lipid metabolism.Conclusions: This study suggested that JMBSH relieves hepatic steatosis by repressing SREBP-1c, which mediates the induction of lipogenic genes. The anti-lipogenic effect of JMBSH may also be related to the activation of AMPK. Therefore, JMBSH could potentially be applied to NAFLD treatment after further clinical studies.

Anti-apoptotic Effects of Red Ginseng on Oxidative Stress Induced by Hydrogen Peroxide in SK-N-SH Cells

  • Kim, Eun-Hye;Lee, Mi-Jeong;Kim, In-Hye;Pyo, Suhk-Neung;Choi, Kwang-Tae;Rhee, Dong-Kwon
    • Journal of Ginseng Research
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    • v.34 no.2
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    • pp.138-144
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    • 2010
  • Ginseng (Panax ginseng C.A. Meyer) has been shown to have anti-stress effects in animal studies. However, most studies have only managed to detect altered levels of biomarkers or enzymes in blood or tissue, and the actual molecular mechanisms by which ginseng exerts these effects remain unknown. In this study, the anti-oxidative effect of Korean red ginseng (KRG) was examined in human SK-N-SH neuroblastoma cells. Incubation of SK-N-SH cells with the oxidative stressor hydrogen peroxide resulted in significant induction of cell death. In contrast, pre-treatment of cells with KRG decreased cell death significantly. To elucidate underlying mechanisms by which KRG inhibited cell death, the expression of apoptosis-related proteins was examined by Western blot analysis. KRG pre-treatment decreased the expression of the pro-apoptotic gene caspase-3, whereas it increased expression of the anti-apoptotic gene Bcl-2. Consistent with this, immunoblot analysis showed that pre-treatment of the SK-N-SH cells with KRG inhibited expression of the pro-inflammatory gene cyclooxygenase 2 (COX-2). RT-PCR analysis revealed that the repression of COX-2 expression by KRG pre-treatment occurred at the mRNA level. Taken together, our data indicate that KRG can protect against oxidative stress-induced neuronal cell death by repressing genes that mediate apoptosis and inflammation.

Characterization of the ${\beta}-Cyclodextrin$ Glucanotransferase Bacillus firmus var. alkalophilus and Its Expression in E. coli

  • Park, Tae-Hyung;Shin, Hyun-Dong;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.811-819
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    • 1999
  • The ${\beta}-CGTase$ gene of alkalophilic Bacillus firmus var. alkalophilus was cloned into E. coli using $pZErO^{TM}-2$ as a vector. The cloned gene encoded a total of 710 amino acid residues consisting of 674 amino acids of the matured protein and 36 amino acids of the signal peptide, including 20 amino acids from the lacZ gene in the vector. Although the cloned ${\beta}-CGTase$ gene did not contain the promoter and start codons, it was expressed by the lac promoter and lacZ start codon in the $pZErO^{TM}$ vector. A comparison was made with the amino acid sequence and ten other CGTases from Bacillus sp. Also, ten highly conserved regions, which are important amino acid residues in catalysis of CGTase, were identified. The lac promoter used for expression of the ${\beta}-CGTase$ gene was induced constitutively in recombinant E. coli even without IPTG possibly because of a lack of the lacI gene in both host and vector, repressing the lacZ gene in the lac operon. Its expression was catabolically repressed by glucose, however, its repression was reduced by soluble starch, mainly because of the extremely high increase of the cAMP level. ${\beta}-CGTase$ can be overproduced in the recombinant E. coli by maintaining intracellular cAMP levels mostly through the intermittent feeding of glucose during cultivation.

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miR-19a Promotes Cell Growth and Tumorigenesis through Targeting SOCS1 in Gastric Cancer

  • Qin, Shuang;Ai, Fang;Ji, Wei-Fang;Rao, Wang;Zhang, He-Cheng;Yao, Wen-Jian
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.835-840
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    • 2013
  • Accumulating evidence has shown that microRNAs are involved in cancer development and progression. However, it remains unknown about the potential role of miR-19a in the pathogenesis of gastric cancer. Here, we report that suppressor of cytokine signaling 1 (SOCS1) is a novel target of miR-19a in gastric cancer cells and that miR-19a expression is inversely correlated with SOCS1 expression in gastric cancer cells and a subset of gastric cancer tissues. Ectopic expression of miR-19a dramatically promoted proliferation and tumorigenicity of gastric cancer cells both in vitro and in vivo. Moreover, we showed that silencing of SOCS1 promoted cell growth and colony formation resembling that of miR-19a overexpression, whereas re-introduction of SOCS1 (without the 3'-UTR) attenuated the pro-tumorigenic functions. Taken together, our findings suggest that the SOCS1 gene is a direct target of miR-19a, which functions as an oncogenic miRNA in gastric cancer by repressing the expression of tumor suppressor SOCS1.