• Parasites, Hosts and Diseases
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• v.54 no.3
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• pp.281-289
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• 2016

Clonorchis sinensis is a Group-I bio-carcinogen, associated with cholangiocarcinoma (CCA). The hamster is the only experimental model of C. sinensis-mediated CCA, but we oblige another animal model. The present study intended to develop a C. sinensis (Cs) mediated CCA model using C3H/He mice, co-stimulated with N-nitrosodimethylamine (NDMA) and dicyclanil (DC). The mice were divided into 8 groups with different combinations of Cs, NDMA, and DC. Six months later the mice were sacrificed and subjected to gross and histopathological examination. The body weights were significantly reduced among the groups treated with 2 or more agents (eg. Cs+NDMA, Cs+DC, NDMA+DC, and Cs+NDMA+DC). In contrast, liver weight percentages to body weight were increased in above groups by 4.1% to 4.7%. A Change of the spleen weight was observed only in Cs+NDMA group. Though C. sinensis infection is evident from hyperplastic changes, only 1 worm was recovered. Two mice, 1 from Cs and the other from Cs+DC group, showed mass forming lesions; 1 ($281.2mm^3$) from the Cs group was a hepatocellular adenoma and the other ($280.6mm^3$) from the Cs+DC group was a cystic mass (peliosis). Higher prevalence of gray-white nodules was observed in Cs group (42.9%) followed by Cs+NDMA+DC group (21.4%). The mice of the Cs+NDMA+DC group showed hyper-proliferation of the bile duct with fibrotic changes. No characteristic change for CCA was recognized in any of the groups. In conclusion, C3H/He mice produce no CCA but extensive fibrosis when they are challenged by Cs, NDMA, and DC together.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.474-483
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• 2019

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, ${\beta}$-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.

• Korean journal of applied entomology
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• v.55 no.2
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• pp.177-188
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• 2016

The alpha-proteobacterium Wolbachia is one of the most important intracellular symbionts of arthropods. This Gram-negative bacterium is involved in many biological processes and is currently considered as a potential tool for biological control. Wolbachia is a cytoplasmic bacterium, maternally transferred through generations, and to facilitate its success, it has evolved several strategies that manipulate its host reproductive system to increase the number of infected individuals in the host population. The variety of Wolbachia was first recognized using genes wsp, 16S rRNA, ftsZ, gltA and groEL as molecular markers while strain genotypes of Wolbachia are determined of Multilocus sequence typing (MLST) and sequence of amino acid in region, hyper variable regions (HVRs) in protein WSP. Possible uses of the bacteria and their predominant phenotypes in control programs for agricultural pests and human disease vectors have been considered. Phenotypes are known to induce cytoplasmic incompatibility (CI), parthenogenesis induction (PI), feminization (F) and male killing (MK). Finally, applications of the bacterium in control programs of agricultural and medical insect pests have been discussed.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.221-246
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• 1998

The aim of this experimental study was to evaluate the anti-tumor effects of Chungsimbohyeltang through investigation about viability of tumor cell by MTT assay, survival period of mice transplanted with L-1210 cells, growth inhibition on the tumor cell, body weight variation in mice transplanted with sarcoma-180 cells and its immunomodulatory effects through the investigation on delayed type hyper-sensitivity, the hemagglutinin and hemolysin titers for humoral immune response, the appearance of rosette forming cells for cell-mediated immune response, the natural killer cell activity, the transformation of lymphocyte, the productivity of Interleukin-2 and phagocytic index K was performed in immune-depressed ICR mice induced by methotrexate treatments. The results were as follows ; 1. $IC_{50}$ of Chungsimbohyeltang treated group was 5.85mg/ml in SNU-C4 cell, 1.38mg/ml in SNU-396 cell, 0.21mg/ml in SNU-1 cell, so it had low anti-tumor activity. 2. The both groups of Chungsimbohyeltang extract 10mg/kg and Chungsimbohyeltang extract 20mg/kg had no toxicity and the group of Chungsimbohyeltang 20mg/kg which was shown 120% in ILS had the effect of life prolongation in mice transplanted with L-1210 cells. 3. In the growth inhibition on the tumor cells, only the group of Chungsimbohyeltang extract 20mg/kg was noted and in the weight variation in mice transplanted with sarcoma-180 cells, both groups of Chungsimbohyeltang extract had a significant effect. 4. In the delayed type hypersensitivity and appearance of rosette forming cells, both groups of Chungsimbohyeltang extract didn't have any significant effect. 5. The hemagglutinin titers was slightly increased with no significance, and the hemolysin titers was significantly increased in the only group of Chungsimbohyeltang extract 20mg/kg. 6. The natural killer cell activity of the Chungsimbohyeltang extract groups was significantly increased in the ratio of 100:1 of effector and target cells, but it was not significantly increased in the ratio of 50:1, 10:1. 7. The transformation of lymphocyte and the productivity of Interleukin-2 were increased significantly and in dose-dependent manner in both group of Chungsimbohyeltang extract. 8. The phagocytic effect of macropage was significantly increased in both groups of Chungsimbohyeltang extract. Considering the results above, we could conclude that Chungsimbohyeltang have an indirect anti-tumor effect through the modulation of immunme response, although it had not toxicity on the tumor cell it self.

• Molecules and Cells
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• v.37 no.11
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• pp.833-840
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• 2014

Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.315-324
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• 2019

In this research, one of five Hofstede's cultural dimension, Long term orientation (LTO) was selected to examine its influence on individual's change oriented organizational citizenship behavior with emotional regulation mediating. East Asian countries and Korea especially received higher score on LTO cultural dimension, meaning it valued harmony, long term relations and saving for future. Also, in today's hyper competitive and evolving global climate, the ability to adapt quickly and also to be able to control one's emotion is highly valued individual competency. Previous research on Hofstede's cultural dimensions were conducted at mostly national or large group levels. However, in this study, Yoo's CVSCALE which allowed for individual level analysis on Hofstede's cultural dimensions were used to analyze multinational company's employees's long term orientations' influence on emotional regulation and change oriented organizational citizenship behavior. The survey conducted from 200 employees from major electronic company based in S city in Korea for two weeks period and the results indicated long term orientation positively influenced change oriented organizational citizenship behavior. Also emotional regulation mediated between long term orientation felt by individuals and change oriented organizational citizenship behavior. Such results validated previous studies that indicated emotional regulation as possible antecedents of individual proactive behaviors such as change organizational citizenship behavior and long term oriented view as another potential antecedent of change oriented organizational citizenship behavior in multinational corporation setting.

• Anatomy and Cell Biology
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• v.51 no.4
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• pp.274-283
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• 2018

Hyper-O-GlcNAcylation is a general feature of cancer which contributes to various cancer phenotypes, including cell proliferation and cell growth. Quercetin, a naturally occurring dietary flavonoid, has been reported to reduce the proliferation and growth of cancer. Several reports of the anticancer effect of quercetin have been published, but there is no study regarding its effect on O-GlcNAcylation. The aim of this study was to investigate the anticancer effect of quercetin on HeLa cells and compare this with its effect on HaCaT cells. Cell viability and cell death were determined by MTT and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling assays. O-GlcNAcylation of AMP-activated protein kinase (AMPK) was examined by succinylated wheat germ agglutinin pulldown and immunoprecipitation. Immunofluorescence staining was used to detect the immunoreactivitiy of O-linked N-acetylglucosamine transferase (OGT) and sterol regulatory element binding protein 1 (SREBP-1). Quercetin decreased cell proliferation and induced cell death, but its effect on HaCaT cells was lower than that on HeLa cells. O-GlcNAcylation level was higher in HeLa cells than in HaCaT cells. Quercetin decreased the expression of global O-GlcNAcylation and increased AMPK activation by reducing the O-GlcNAcylation of AMPK. AMPK activation due to reduced O-GlcNAcylation of AMPK was confirmed by treatment with 6-diazo-5-oxo-L-norleucine. Our results also demonstrated that quercetin regulated SREBP-1 and its transcriptional targets. Furthermore, immunofluorescence staining showed that quercetin treatment decreased the immunoreactivities of OGT and SREBP-1 in HeLa cells. Our findings demonstrate that quercetin exhibited its anticancer effect by decreasing the O-GlcNAcylation of AMPK. Further studies are needed to explore how quercetin regulates O-GlcNAcylation in cancer.