• Title/Summary/Keyword: critical region

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Regulation of Matrix Metalloproteinase-1 Expression by the Homeodomain Transcription Factor Caudal in Drosophila Intestine (초파리 장조직에서 Caudal 전사조절인자에 의한 matrix metalloproteinase-1 발현 조절)

  • Lee, Shin-Hae;Hwang, Mi-Sun;Choi, Yoon-Jeong;Kim, Young-Shin;Yoo, Mi-Ae
    • Journal of Life Science
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    • v.22 no.12
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    • pp.1600-1607
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    • 2012
  • The matrix metalloproteinase (MMP) family plays essential roles in physiological processes such as embryonic development, angiogenesis, wound healing, and tissue homeostasis as a consequence of MMPr capacity for breaking down many types of extracellular matrix proteins. Imbalanced regulation of MMP expression can also lead to pathological conditions such as tumor progression. We recently reported that the Drosophila Mmp1 gene is highly expressed in the digestive tract and is required for the maintenance of intestinal homeostasis such as by restriction of uncontrolled intestinal stem cell proliferation. However, the regulatory mechanisms of MMP gene expression in the intestine remain unclear. In this study, we determined that the expression of Mmp1 is regulated by the homeodomain transcription factor Caudal. Experiments using the targeted expression of Caudal under the regulation of Gal4-UAS system indicated that endogenous Caudal is required for the Mmp1 gene expression in the adult Drosophila intestine and that exogenous Caudal induces Mmp1 expression. Transient transfection experiments indicated that Caudal can activate the promoter activity of Mmp1 and that several putative Caudal binding sites in the 5'-flanking region of the Mmp1 gene may be critical to the upregulation by Caudal. Our data suggest that Mmp1 is one of the target genes of Caudal in physiological normal condition and in tumorigenesis.

xCyp26c Induced by Inhibition of BMP Signaling Is Involved in Anterior-Posterior Neural Patterning of Xenopus laevis

  • Yu, Saet-Byeol;Umair, Zobia;Kumar, Shiv;Lee, Unjoo;Lee, Seung-Hwan;Kim, Jong-Il;Kim, SungChan;Park, Jae-Bong;Lee, Jae-Yong;Kim, Jaebong
    • Molecules and Cells
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    • v.39 no.4
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    • pp.352-357
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    • 2016
  • Vertebrate neurogenesis requires inhibition of endogenous bone morphogenetic protein (BMP) signals in the ectoderm. Blocking of BMPs in animal cap explants causes the formation of anterior neural tissues as a default fate. To identify genes involved in the anterior neural specification, we analyzed gene expression profiles using a Xenopus Affymetrix Gene Chip after BMP-4 inhibition in animal cap explants. We found that the xCyp26c gene, encoding a retinoic acid (RA) degradation enzyme, was upregulated following inhibition of BMP signaling in early neuroectodermal cells. Whole-mount in situ hybridization analysis showed that xCyp26c expression started in the anterior region during the early neurula stage. Overexpression of xCyp26c weakly induced neural genes in animal cap explants. xCyp26c abolished the expression of all trans-/cis-RA-induced posterior genes, but not basic FGF-induced posterior genes. Depletion of xCyp26c by morpholino-oligonucleotides suppressed the normal formation of the axis and head, indicating that xCyp26c plays a critical role in the specification of anterior neural tissue in whole embryos. In animal cap explants, however, xCyp26c morpholinos did not alter anterior-to-posterior neural tissue formation. Together, these results suggest that xCyp26c plays a specific role in anterior-posterior (A-P) neural patterning of Xenopus embryos.

Tristetraprolin Overexpression in Gastric Cancer Cells Suppresses PD-L1 Expression and Inhibits Tumor Progression by Enhancing Antitumor Immunity

  • Guo, Jian;Qu, Huiheng;Shan, Ting;Chen, Yigang;Chen, Ye;Xia, Jiazeng
    • Molecules and Cells
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    • v.41 no.7
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    • pp.653-664
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    • 2018
  • The RNA-binding protein tristetraprolin (TTP) binds to adenosine-uridine AU-rich elements in the 3'-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their micro-environment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PD-L1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

Cloning and Characterization of a Gene Coding for a Dextransucrase from Leuconostoc mesenteroides B-742CB (Leuconostoc mesenteroides B-742CB로부터 Dextransucrase를 Coding하는 유전자 분리 및 특성 연구)

  • 박미란;이소영;류화자;김호상;강희경;유선균;조성용;조동련;김도만
    • KSBB Journal
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    • v.16 no.2
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    • pp.188-199
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    • 2001
  • A gene encoding the dextransucrase(dsCB) that synthesizes mostly $\alpha-(1\rightarrow6)$ linked dextran with low amount(10%) of $\alpha-(1\rightarrow3)$ branching was cloned and sequenced from Leuconostoc mesenteroides B-742CB. The 6.1 kbp DNA fragment carrying dsCB showed one open reading frame(ORF) composed of 4,536bp. The deduced amino acid sequence shows that it begins from the start codon(ATG) at position 698 of the cloned DNA fragment and extends to the termination condon(TAA) at position 5,223. The enzyme is consisted of 1,508 amino acids and has an calculated molecular mass of 168.6kDa. This calculated Mw was in good agreement with an activity band of 170kDa on non-denaturing SDS-PAGE. A recombinant E. coli DH5 $alpha$ harboring pDSCB produced extracellular dextransucrase in 2% sucrose medium, and synthesized both soluble and insoluble dextran. To compare the properties of enzyme with B-742CB dextransucrase, the acceptor reaction, hydrolysis of dextran and methylation were performed. The expressed enzyme showed the same properties as B-742CB dextransucrease, but its ability to synthesize $\alpha-(1\rightarrow3)$ branching was lower than that of B-742CB dextransucrase. In order to identify the critical amino acid residues known as conserved regions related to catalytic activity, Asp-492 was replaced with Asn. D492N resulted in a 1.6 fold decrease in specific activity.

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Institutional Milieu of High-Tech Venture Business Cluster in a Metropolitan Area: the Case of Daegu City in Korea (지방대도시 벤처생태계의 제도적 및 문화적 환경: 대구지역을 사례로)

  • 이철우;이종호
    • Journal of the Economic Geographical Society of Korea
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    • v.7 no.1
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    • pp.1-27
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    • 2004
  • In this paper we attempt to explore the institutional and clutural milieu of high-tech venture business cluster in Daegu City and provide policy implications for creating sustainable high-tech venture businesses cluster. Although since 1998 the Korean government has made explicitly a great deal of efforts to help attract and create high-tech new start-ups in non-capital cities such as the support of business incubating centers and the establishment of real service centres, it reveals that such policies are not so successful in creating a sustainable venture ecology. One of the most critical resions is that such policies are centred simply on building physical infrastructure such as incubating space and service centre with less concern with promoting venture business cluster reflecting cultural and institutional specificities in a given region. In this respect we argue that the focus of industrial policies to support promoting high-tech venture business clusters in non-capital cities urgently need to move towards to make it for firms to encourage entrepreneurship driving innovation and to create social capital incucing trust and networks amongst firms, universities, public &privite supporting agencies, together with the building up of physical infrastructure the existing policies have done.

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A Critical Assessment on the Foreign Direct Investment-led Regional Development Strategy: A Case Study of Wales, UK (외국인직접투자 유치를 통한 지역발전전략의 성과와 한계: 영국 웨일스의 사례를 중심으로)

  • Lee, Dong-Heon;Sonn, Jung-Won
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.4
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    • pp.438-453
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    • 2009
  • Attracting advanced foreign enterprises into the less-developed regions has gained increasing importance as a regional development strategy in Korea. This study critically examines the foreign-direct investment-led regional development strategy of Wales, United Kingdom. Despite a high FDI inflow in manufacturing, the Welsh regional economy has suffered from specialization in low-skilled assembly with limited R&D activities, insufficient linkage with local domestic suppliers, and violent fluctuation in local employment in response to changes within the global business environment. This tendency shows that the foreign-invested companies have neither locally embedded themselves enough nor created the external agglomeration economies in the region. At the same time, the Welsh local government's excessive dependence on financial incentives packages to induce multinationals, rather than effort to create regional innovative capacity, has resulted in a sizable fiscal loss, an abused local planning process, and subordination of the local government's major administrative decision-making on foreign investors. The Welsh FDI case suggests that an effective FDI attraction policy should include inter-regional cooperation and coordination in the inward investment attraction procedure, a comprehensive land use planning process, and state-level concrete governance on FDI.

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The Post-IMF firm strategy and the corporate restructuring in the heavy & chemical industrial district: the case of Ulsan, Korea (울산 중화학공업의 재구조화 특성 - IMF 체제 이후의 기업전략을 중심으로 -)

  • Park, Yang-Choon
    • Journal of the Korean association of regional geographers
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    • v.7 no.2
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    • pp.17-34
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    • 2001
  • This paper is to analyze how firms in a large firm-led industrial city have carried out the restructuring in the face of radical shifts, with focus on the strategy and the restructuring of firms in Ulsan, a typical industrial district in Korea that is specialized in heavy & chemical industry. It has been well known that the local economy has been led by a small number of large firms, including affiliates of chaebol, and its industrial structure has also been characterised as a clear dichotomy between large firms as a customer and small and medium-size firms as a supplier, which can be called not horizontal but vertical relations. It can identify some tendencies, however, that local companies have been rather dynamically changing in response to increasingly turbulent environment since the Asian crisis. Some are radical, but some incremental. These can be summarized in four distinctive but interlinked ways. First, more than half of local companies surveyed have attempted to change their production systems, mainly from the fordist mass production towards the flexible mass production, seeking both economies of scale and scope. Second, local firms have vigorously continued to reorganize the boundary of the production and the organization, by specializing products and focusing on the core competence in order to save costs and cope with radically changing customer demands in a flexible way. Third, there have been various strategies for the organizational innovation such as the introduction of team organization, the boundary blurring between the managerial and production workers and the intra-firm spin-offs, so as to improve managerial efficiency and competence in the use of internal labour market. Finally, they have tried to be more sensitive to the market and customers. These tendencies seem to be increasingly critical to sustain their competitiveness. To do so, they tend to focus increasingly not only on the competing via the product quality rather than through price, but also to seek to diversify the market and customer firms beyond national boundary.

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Investigation on Influencing Environmental Factors on Health Status of Korean Septuagenarians Dwelling in Longevity Region in Jeonla Province (전라도 농촌장수지역 거주 70대 노인의 건강상태에 영향을 미치는 환경적 요인에 대한 탐색 연구)

  • Kwak, Chung Shil;Yon, Miyong;Lee, Mee Sook;Oh, Se In;Park, Sang Chul
    • Korean Journal of Community Nutrition
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    • v.19 no.2
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    • pp.142-162
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    • 2014
  • Objectives: To evaluate the critical environmental factors on healthy-aging of Korean people, we investigated the significant factors influencing health status of septuagenarians living in rural area of Jeonla province, known to be one of the representative longevity regions in Korea. Methods: We divided subjects into healthy group (36M/25F) or poor-health group (26M/73F) based on self-reported health status, body mass index, a number of prescription, and blood test data. General characteristics, physical measurements, lifestyle, dietary behavior and nutrient intake, physical health and mental health data were statistically compared between the two groups. Results: Average age was not different between healthy group and poor-health group in men and women, respectively. In men, significantly favorable factors to health were observed to be higher education, regular exercise, higher grip strength and walking function, body mass index (${\geq}18.5kg/m^2$), moderate frequency of drinking and eating-out, non-smoking, normal red blood cell (RBC) count, higher serum dehydroepiandrosterone-sulfate (DHEAS) level, good digestive function and appetite, normal hearing function, regular meals, adequate vegetable and fruit intake, diverse food intake, adequate energy and nutrients (protein, vitamin $B_1$, $B_6$, C and E, folate, niacin, P, Zn and K) intake, higher mini-nutrient status assessment (MNA) score and low level of depression. On the other hand, in women, those were literacy, living arrangement, moderate frequency of drinking, healthy teeth, higher grip strength and walking function, bone mineral density, normal RBC and white blood cell (WBC) count, higher DHEAS concentration, higher MNA score, normal cognition and memory function, having snack and adequate fruit intake. Conclusions: These results could be useful to plan effective strategies to increase health-life expectancy of Korean old people living in rural areas.

Critical Discussion on the 'Orientalism' in Fashion Culture (패션문화에 나타난 오리엔탈리즘에 대한 비판적 논의)

  • Seo, Bong-Ha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.6
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    • pp.902-910
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    • 2008
  • A view of the Orientalism that sees the Orient as the inferior Other, characterized by the heterogenic, eccentric, backward, and passive features, has been internalized in the unconsciousness of Westerners. 'Orientalism' which is the cultural device and the system of discourse to put Asia in the fixed frame of dominance was the West European centered term, designating Southwest Asia including South Europe and North Africa as Orient, and contained the idea that non-Western society could progress only with the acceptance of Western civilization. Accordingly, it is need to use this term deliberately. In addition, even though the Asian Look of the West, borrowing the images and costume styles of Asia has lost the original mentality of Asia, it was not initiated from the perception that sees Asia as the inferior Other. Since the Asian Ethnic Look is the Western costume, borrowing the image of Orient and style by being fascinated by Oriental Aesthetics, the attributes of it are different from those of Orientalism. Therefore, it is not appropriate to designate the Asian Ethnic Look as 'Orientalism Fashion' or 'Oriental Look' except for some eccentric manipulation of Asia costume and image. Instead, it is desirable to exchange the term 'Asian Look', 'Asian Fashion', and 'Asian Ethnic Look' upon occasions or the name of individual nation or region can be referred to as preferred alternatives. Today, Asia including Korea is taking the initiative in the World Fashion as one of central axes of World Fashion Industry, and cannot be interpreted from the perspective of West Centrism. Now, it's time to dissolve the dichotomous prejudice of the West centrism on Asia's own strength.

Dispersion Characteristics of Hydrogen Gas by the Effect of Leakage Hole Size in Enclosure Space (누출공 크기에 따른 밀폐공간 내 수소 가스의 확산 특성)

  • Choi, Jinwook;Li, Longnan;Park, Chul-Woo;Lee, Seong Hyuk;Kim, Daejoong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.26-35
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    • 2016
  • As a potential clean energy resource, the production and consumption of hydrogen gas are expected to gradually increase, so that hydrogen related studies are also increasing. The thermal and chemical properties of hydrogen result in its high flammability; in particular, there is a high risk if leaks occur within an enclosed space. In this study, we applied the computational fluid dynamics method to conduct a numerical study on the leakage behavior of hydrogen gas and compared these numerical study results with an experimental study. The leakage hole diameter was selected as an important parameter and the hydrogen gas dispersion behavior in an enclosed space was investigated through various analytical methods. Moreover, the flammable regions were investigated as a function of the leakage time and leakage hole size. We found that the growth rate of the flammable region increases rapidly with increasing leakage hole size. We also investigated the relation between the mass flow rate and the critical time when the hydrogen gas reaches the ceiling. The analysis of the monitoring points showed that the hydrogen gas dispersion behavior is isotropic and independent of the geometry. We found that the concentration of gas in an enclosed space is affected by both the leakage flow rate and amount of gas accumulated in the enclosure.