• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.495-498
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• 2013

Epidermal growth factor receptor (EGFR) is over-expressed in several human cancers. This would suggest that inhibition of EGFR is a reasonable approach for cancer treatment. In this study we investigated EGFR blocking and its effects on the mediated signaling such as MAPK and STATb in HT29 cells. For this aim we used FITC-labeled EGFR antisense oligonucleotides encapsulated with PAMAM nanoparticles to inhibit EGFR expression. Cellular uptake of antisense was investigated by fluorescence microscopy and flow cytometry analysis. The effect of EGFR antisense on the expression of EGFR in HT29 cells was examined by real time PCR and Western blots, which showed that antisense encapsulated with PAMAM decreased the level of EGFR mRNA and protein. In addition, real time PCR results confirmed that EGFR inhibition had an effective role in the reduction of EGFR dependent downstream genes. In conclusion, EGFR antisense encapsulated with PAMAM nanoparticles down regulated EGFR and EGFR-mediated genes.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2325-2331
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• 2011

Human CDX1 and CDX2 genes play important roles in the regulation of cell proliferation and differentiation in the intestine. Hox genes clustered on four chromosomal regions (A-D) specify positional signaling along the anterior-posterior body axis, including intestinal development. Using glutathione S-transferase (GST) pulldown assays, molecular interaction measurements, and fluorescence measurements, we found that the homeodomains (HDs) of CDX1 and CDX2 directly interact with that of HOXD8 in vitro. CDX1 showed significant affinity for HOXD8, but CDX2 showed weak affinity for HOXD8. Thus far, three-dimensional structures of CDX1/2 and HOXD8 have not been determined. In this study, we developed a molecular docking model by homology modeling based on the structures of other HD members. Proteins with mutations in the HD of CDX1 (S185A, N190A, T194A, and V212A) also bound to the HD of HOXD8. Our study suggests that the HDs of CDX1/2 resemble those of HOXD8, and we provide the first insight into the interaction between the HDs of CDX1/2 proteins and those of HOXD8.

• The Plant Pathology Journal
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• 제29권4호
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• pp.427-434
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• 2013

2R,3R-Butanediol, a volatile compound produced by certain rhizobacteria, is involved in induced drought tolerance in Arabidopsis thaliana through mechanisms involving stomatal closure. In this study, we examined the involvement of nitric oxide and hydrogen peroxide in induced drought tolerance, because these are signaling agents in drought stress responses mediated by abscisic acid (ABA). Fluorescence-based assays showed that systemic nitric oxide and hydrogen peroxide production was induced by 2R,3R-butanediol and correlated with expression of genes encoding nitrate reductase and nitric oxide synthase. Co-treatment of 2R,3R-butanediol with an inhibitor of nitrate reductase or an inhibitor of nitric oxide synthase lowered nitric oxide production and lessened induced drought tolerance. Increases in hydrogen peroxide were negated by co-treatment of 2R,3R-butanediol with inhibitors of NADPH oxidase, or peroxidase. These findings support the volatile 2R,3R-butanediol synthesized by certain rhizobacteria is an active player in induction of drought tolerance through mechanisms involving nitric oxide and hydrogen peroxide production.

• Asian Pacific Journal of Cancer Prevention
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• 제14권2호
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• pp.895-901
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• 2013

Resistance to induction of apoptosis is a major obstacle for bladder cancer treatment. Bcl-2 is thought to be involved in anti-apoptotic signaling. In this study, we investigated the effect of Bcl-2 overexpression on apoptotic resistance and intracellular reactive oxygen species (ROS) generation in bladder cancer cells. A stable Bcl-2 overexpression cell line, BIU87-Bcl-2, was constructed from human bladder cancer cell line BIU87 by transfecting recombinant Bcl-2 [pcDNA3.1(+)-Bcl-2]. The sensitivity of transfected cells to adriamycin (ADR) was assessed by MTT assay. Apoptosis was examined by flow cytometry and acridine orange fluorescence staining. Intracellular ROS was determined using flow cytometry, and the activities of superoxide dismutase (SOD) and catalase (CAT) were also investigated by the xanthinoxidase and visible radiation methods using SOD and CAT detection kits. The susceptibility of BIU87-Bcl-2 cells to ADR treatment was significantly decreased as compared with control BIU87 cells. Enhanced expression of Bcl-2 inhibited intracellular ROS generation following ADR treatment. Moreover, the suppression of SOD and CAT activity induced by ADR treatment was blocked in the BIU87-Bcl-2 case but not in their parental cells. The overexpression of Bcl-2 renders human bladder cancer cells resistant to ADR-induced apoptosis and ROS might act as an important secondary messenger in this process.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.677-680
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• 2007

To analyze a cotG-based Bacillus subtilis spore display system directly, $GFP_{UV}$ was expressed on the surface of Bacillus subtilis spores. When $GFP_{UV}$ was fused to the C-terminal of the cotG structural gene and expressed, the existence of a $CotG-GFP_{UV}$ fusion protein on the B. subtilis spore was confirmed by flow cytometry confocal microscopic analysis. When the cotG anchoring motif was deleted, no fluorescence emission was observed under flow cytometry and confocal microscopic analysis from the purified spore, confirming the essential role of CotG as an anchoring motif. This $GFP_{UV}$ displaying spore might be used for another signaling application triggered by intracellular or extracellular stimuli.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.1-8
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• 2016

Damage in the periphery or spinal cord induces maladaptive plastic changes along the somatosensory nervous system from the periphery to the cortex, often leading to chronic pain. Although the role of neural circuit remodeling and structural synaptic plasticity in the 'pain matrix' cortices in chronic pain has been thought as a secondary epiphenomenon to altered nociceptive signaling in the spinal cord, progress in whole brain imaging studies on human patients and animal models has suggested a possibility that plastic changes in cortical neural circuits may actively contribute to chronic pain symptoms. Furthermore, recent development in two-photon microscopy and fluorescence labeling techniques have enabled us to longitudinally trace the structural and functional changes in local circuits, single neurons and even individual synapses in the brain of living animals. These technical advances has started to reveal that cortical structural remodeling following tissue or nerve damage could rapidly occur within days, which are temporally correlated with functional plasticity of cortical circuits as well as the development and maintenance of chronic pain behavior, thereby modifying the previous concept that it takes much longer periods (e.g. months or years). In this review, we discuss the relation of neural circuit plasticity in the 'pain matrix' cortices, such as the anterior cingulate cortex, prefrontal cortex and primary somatosensory cortex, with chronic pain. We also introduce how to apply long-term in vivo two-photon imaging approaches for the study of pathophysiological mechanisms of chronic pain.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.119-123
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• 1999

Parathyroid hormone (PTH) treatment of bone and kidney-derived cells not only activates adenyly cyclase buy also increases intracellular free calcium, and translocates protein kinase C (PKC) from cytosol to plasma membranes. We have found that acute phorbol ester pretreatment significantly decreases PTH-induced calcium transients and the effect of phorbol ester was antagonized by staurosporine (ST). Although the major effect of ST in that study was the reversal of the action of phorbol ester, it appeared that ST may also have promoted the effect of PTH directly. To further investigate the observation, we examined the effect of ST on the intracellular calcium transients induced by PTH and $\alpha$-thrombin ($\alpha$-TH). For calcium transient experiments, UMR-106 cells were loaded with 2 mM fluo-acetoxymethylester for 30 min at room temperature. The cells were then washed and suspended in buffer containing 1 mM calcium. Fluorescence was detected at 530 nm, with excitation at 505 nm. ST alone did not cause calcium transients, but enhanced the transients elicited by PTH response. added 5 min before the hormone. Another protein kinase inhibitor H-7 likewise enhanced the calcium responses elicited by PTH, while genistein did not affect PTH response. Calcium transients elicited by $\alpha$-TH were also enhanced by ST. The results suggest that there might be tonically activated endogenous protein kinase(s) which inhibit calcium signaling of some calcemic agents.

• Biomolecules & Therapeutics
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• 제31권4호
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• pp.425-433
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• 2023

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

• Parasites, Hosts and Diseases
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• 제61권4호
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• pp.388-396
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• 2023

Entamoeba histolytica is an enteric tissue-invasive protozoan parasite causing amoebic colitis and liver abscesses in humans. Amoebic contact with host cells activates intracellular signaling pathways that lead to host cell death via generation of caspase-3, calpain, Ca²⁺ elevation, and reactive oxygen species (ROS). We previously reported that various NADPH oxidases (NOXs) are responsible for ROS-dependent death of various host cells induced by amoeba. In the present study, we investigated the specific NOX isoform involved in ROS-dependent death of hepatocytes induced by amoebas. Co-incubation of hepatoma HepG2 cells with live amoebic trophozoites resulted in remarkably increased DNA fragmentation compared to cells incubated with medium alone. HepG2 cells that adhered to amoebic trophozoites showed strong dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence, suggesting intracellular ROS accumulation within host cells stimulated by amoebic trophozoites. Pretreatment of HepG2 cells with the general NOX inhibitor DPI or NOX2-specific inhibitor GSK 2795039 reduced Entamoeba-induced ROS generation. Similarly, Entamoeba-induced LDH release from HepG2 cells was effectively inhibited by pretreatment with DPI or GSK 2795039. In NOX2-silenced HepG2 cells, Entamoeba-induced LDH release was also significantly inhibited compared with controls. Taken together, the results support an important role of NOX2-derived ROS in hepatocyte death induced by E. histolytica.

• 생명과학회지
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• 제30권6호
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• pp.532-541
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• 2020

본 연구는 지방감소를 위한 소재개발로 감국 유산균 발효물이 갖는 지방구세포 분화 억제효과를 관찰하였다. 감국 추출물의 세포독성을 극복하는 유산균의 발효물을 제작하였다. 3T3-L1 세포주에서 감국 추출물 및 발효물이 갖는 세포독성은 모두 없었다(1day culture). 감국 추출물 처리 대조군과 비교하여 3T3-L1 세포주에 처리시 증식 유도된 발효물을 선별하였다. 감국 추출물 및 발효물의 분화억제 및 세포생존률 FACS분석은 분화 유도된 세포가 모든 실험군에서 줄어들었다. 3T3-L1 세포주에서 감국 추출물과 발효물 처리가 protein kinase B (Akt) pathway활성이 증가하였고, 단백질 발현은 지방구세포로 분화되면서 Gli2의 수준은 감소하였다. Hedgehog를 조절하는 유산균은 KCTC 3115인 것을 알 수 있었다. 분화와 관련된 KCTC 3115 및 KCTC 3109 발효군에서 단백질 수준에서 C/EBPα 및 FAS를 감소, pACC는 증가시키는 것을 확인하였다. 감국 추출물과 4개의 감국 유산균 발효물 중 Lactococcus lactis subsp. lactis KCTC 3115 발효물이 지방구세포 분화 신호를 더 효과적으로 조절하고, hedgehog을 같이 조절하여 지방전구세포의 분화를 억제하는 것을 알 수 있었다. Hedgehog 신호를 조절하면서 분화를 억제하는 물질에 대한 연구가 더 필요할 것으로 판단된다. 따라서 감국 발효물의 생리활성 물질 중 향후 매커니즘 분석을 위한 활성물질의 자료가 더 필요할 것으로 여겨지며, 감국 추출물 및 감국 발효물의 hedgehog 신호조절이 새로운 비만치료제로 개발될 수 있음을 위한 가능성을 제시하고자 한다.