• IMMUNE NETWORK
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• v.11 no.5
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• pp.268-280
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• 2011

Background: Dengue virus, which belongs to the Flavivirus genus of the Flaviviridae family, causes fatal dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) with infection risk of 2.5 billion people worldwide. However, approved vaccines are still not available. Here, we explored the immune responses induced by alternating prime-boost vaccination using DNA vaccine, adenovirus, and vaccinia virus expressing E protein of dengue virus type 2 (DenV2). Methods: Following immunization with DNA vaccine (pDE), adenovirus (rAd-E), and/or vaccinia virus (VV-E) expressing E protein, E protein-specific IgG and its isotypes were determined by conventional ELISA. Intracellular CD154 and cytokine staining was used for enumerating CD4+ T cells specific for E protein. E protein-specific CD8+ T cell responses were evaluated by in vivo CTL killing activity and intracellular IFN-${\gamma}$ staining. Results: Among three constructs, VV-E induced the most potent IgG responses, Th1-type cytokine production by stimulated CD4+ T cells, and the CD8+ T cell response. Furthermore, when the three constructs were used for alternating prime-boost vaccination, the results revealed a different pattern of CD4+ and CD8+ T cell responses. i) Priming with VV-E induced higher E-specific IgG level but it was decreased rapidly. ii) Strong CD8+ T cell responses specific for E protein were induced when VV-E was used for the priming step, and such CD8+ T cell responses were significantly boosted with pDE. iii) Priming with rAd-E induced stronger CD4+ T cell responses which subsequently boosted with pDE to a greater extent than VV-E and rAd-E. Conclusion: These results indicate that priming with live viral vector vaccines could induce different patterns of E protein-specific CD4+ and CD8+ T cell responses which were significantly enhanced by booster vaccination with the DNA vaccine. Therefore, our observation will provide valuable information for the establishment of optimal prime-boost vaccination against DenV.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.113-122
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• 2014

A5E is complex of several medicinal herb ethanol extracts. The aim of this study is investigating the anticancer effect for non-small cell lung cancer. The antitumor effects of A5E on NCI-H460 were examined by regulation of cell proliferation, apoptosis, cell cycle arrest, mitochondrial membrane potential (${\Delta}{\Psi}_m$), and apoptosis-related protein. Cell proliferation was measured by MTS assay. Apoptosis induced by A5E was confirmed by Annexin V-fluorescein isothiocyanate (FITC)/Propidium Iodide (PI) staining, and cell cycle arrest was measured by PI staining. NF-${\kappa}B$ translocation was detected by immunofluorescence and MMP (${\Delta}{\Psi}_m$) was measured by JC-1 staining. The expression of extrinsic pathway molecules such as FasL and FADD were elevated, and procaspase-8 was processed by A5E. In addition, intrinsic pathway related molecules were altered. The Bcl-2 and Bcl-xl levels decreased, Bax increased, and cytochrome C was released. In addition, the mitochondrial membrane potential collapsed, and caspase-3 and poly-(ADP-ribose) polymerase were processed by A5E. Moreover, A5E affected the cellular survival pathway involving phosphatidylinositol 3-kinase (PI3K)/Akt and NF-${\kappa}B$. PI3K and Akt were downregulated, also NF-${\kappa}B$ expression was decreased, and nuclear translocalization was inhibited by A5E. These results suggested that A5E delays proliferation, inhibit cell cycle progression and induce apoptosis in human lung cancer cell. We conclude that A5E is a potential anticancer agent for human lung carcinoma.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.239-245
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• 2012

Purpose: Vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis and lymphangiogenesis including induction of endothelial cell proliferation, migration and capillary tube formation. E7080 (S1164, Selleck chemical, Houston, TX, USA) is a muti-targeted kinase inhibitor, which targets VEGF receptor-2, 3 (VEGFR-2, 3) and inhibits survival and proliferation of tumor cell. The purpose of this study was to determine the anti-tumor effect of E7080 on oral squamous cell carcinoma. Methods: An oral squamous cell carcinoma cell line, SCC-9 was used in this study. E7080 was applied to SCC-9 cells by 3 different concentrations (1, 5, 10 ${\mu}g/mL$). Control means no application of E7080. The cellular growth was evaluated by real-time cell electronic sensing and MTT assay. The signal transduction was evaluated by Western blotting. Results: In experimental group, SCC-9 cell proliferation was decreased and the VEGFR-3 downstream pathways were inhibited compared with control. Furthermore, increasing the concentration of E7080, the ability of E7080 to disturbance of SCC-9 cell proliferation was increased. Conclusion: Proliferation of SCC-9 cells was inhibited by E7080, which was through by inhibition of VEGFR-3 downstream pathway. In vivo study with E7080 will be required to provide therapeutic benefits in oral squamous cell carcinoma.

• Parasites, Hosts and Diseases
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• v.51 no.1
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• pp.61-68
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• 2013

Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoebainduced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.185-189
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• 1987

The number of splenic lymphocyte, serum prostaglandin $E_2$ level and natural killer cell activity were assayed after single whole body irradiation of a sublethal dose of $^{60}Co-{\gamma}$ ray to C57BL/6J mice. With a view to knowing the relationships between radiation induced prostaglandin $E_2$ level and the normal natural killer cell activity after natural killer cell-target cell conjugation, The change of normal natural killer cell activity were measured by administration of prostaglandin $E_2$ containing serum from irradiated mice. The results were summarized as follows; 1. The total number of splenic lymphocyte was significantly decreased by irradiation and the number was not affected by indometacin, prostaglandin synthesis inhibitor, treatment. 2. Serum prostaglandin $E_2$ level was increased in irradiated mice, but indometacin treated mice group showed low level of prostaglandin $E_2$. 3. In the case of irradiated mice, natural killer cell activity was not shown any difference between irradiated group and indometacin combined group. But when natural killer cell-target cell conjugations were exposed to the serum of each group during cytotoxic activity assay, whereas the normal natural killer cell activity was significantly decreased by treatment of serum from irradiated mice, the activity was not changed by treatment of indometacin pretreated mice serum. This result indicated that the prostaglandin $E_2$ induced by the radiation inhibited the post-target binding cytolytic process of natural killer activity.

• KSBB Journal
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• v.29 no.4
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• pp.263-270
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• 2014

This study reports significant improvement of atopic dermatitis condition as a result of experiment using Xanthium strumarium L. extract (XS-E) at the dorsal skin of induced atopic dermatitis Nc/Nga mice. Skin clinical score has decreased ($2.75{\pm}0.85$, *p<0.05), showing visible change of skin condition. IgE (***p<0.001) and IgG1 ($2522.00{\pm}32.80$, ***p<0.001) in plasma also decreased significantly. mRNA (gene expression) level increased ($RQ=2.75{\pm}0.10$, ***p<0.001) within skin tissue of CD4+CD25+Foxp3+ Treg cell that's activated by XS-E dosage, thereby discovering that there is an effect of suppressing proliferation and viability of Th2 cell, eosinophils, mast cell and inflammatory cell. Upon examining cells permeated with H&E and toluidine blue staining technique, thickness of epidermis and mast cell's permeation decreased, and the result of examining the distribution of CCR 3+ eosinophils within ALN showed that it's level fell down to that of wild type (normal group, NC/Nga-WT). By such results, it is suggested that XS-E is highly effective on atopic dermatitis, and it is considered that continued quantitative research and case study of clinical research such as effect of cell number in individual tissues or change of total cell number are necessary.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.334-345
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• 2022

Background and Objectives: Flavonoids form the largest group of plant phenols and have various biological and pharmacological activities. In this study, we investigated the effect of a flavonoid, 3, 4'-dihydroxyflavone (3, 4'-DHF) on osteogenic differentiation of equine adipose-derived stromal cells (eADSCs). Methods and Results: Treatment of 3, 4'-DHF led to increased osteogenic differentiation of eADSCs by increasing phosphorylation of ERK and modulating Reactive Oxygen Species (ROS) generation. Although PD98059, an ERK inhibitor, suppressed osteogenic differentiation, another ERK inhibitor, U0126, apparently increased osteogenic differentiation of the 3, 4'-DHF-treated eADSCs, which may indicate that the effect of U0126 on bone morphogenetic protein signaling is involved in the regulation of 3, 4'-DHF in osteogenic differentiation of eADSCs. We revealed that 3, 4'-DHF could induce osteogenic differentiation of eADSCs by suppressing ROS generation and co-treatment of 3, 4'-DHF, U0126, and/or N-acetyl cysteine (NAC) resulted in the additive enhancement of osteogenic differentiation of eADSCs. Conclusions: Our results showed that co-treatment of 3, 4'-DHF, U0126, and/or NAC cumulatively regulated osteogenesis in eADSCs, suggesting that 3, 4'-DHF, a flavonoid, can provide a novel approach to the treatment of osteoporosis and can provide potential therapeutic applications in therapeutics and regenerative medicine for human and companion animals.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.6
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• pp.391-397
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• 2010

E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.533-538
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• 2016

Angiogenesis plays an essential role in embryo development, tissue repair, inflammatory diseases, and tumor growth. In the present study, we showed that endothelial nitric oxide synthase (eNOS) regulates retinal angiogenesis. Mice that lack eNOS showed growth retardation, and retinal vessel development was significantly delayed. In addition, the number of tip cells and filopodia length were significantly reduced in mice lacking eNOS. Retinal endothelial cell proliferation was significantly blocked in mice lacking eNOS, and EMG-2-induced endothelial cell sprouting was significantly reduced in aortic vessels isolated from eNOS-deficient mice. Finally, pericyte recruitment to endothelial cells and vascular smooth muscle cell coverage to blood vessels were attenuated in mice lacking eNOS. Taken together, we suggest that the endothelial cell function and blood vessel maturation are regulated by eNOS during retinal angiogenesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.1-6
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• 2005

It becomes more concerned that the cell adhesion molecule plays an important role in the process of malignant transformation and tumor behaviors including invasive growth and metastasis. It is postulated if the expression of adhesion molecule is reduced in tumor tissue, the tumor cell will be undifferentiated and lose their cell adhesion ability and polarity. So the tumor cells lost the adhesion of cell to cell and to basement membrane that they became more aggressive. Reduced cadherin expression enhances invasiveness through infiltrative growth and metastasis of tumor cells is well known and mostly accepted in many epithelia tumors. We explored the expression of E-cadherin by immunohistochemical staining in 50 oral squamous cell carcinomas and investigated the correlation between the expression of E-cadherin and clinicopathologic parameters and prognosis. The expression of E-cadherin was reduced in 40/50(80%) of primary tumors, and 21/22(95.5%) of lymph nodes. The reduced expression of the E-cadherin was associated with lymph node metastasis(P=0.029), invasive mode(P=0.030) and marginal status(P=0.038). Survival analysis showed that predictive period of E-cadherin reduced group(37 months) was lower than that of E-cadherin preserved group(60 months), but there was no statistical significant difference.