• Animal cells and systems
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• v.6 no.2
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• pp.171-180
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• 2002

Nitric oxide has high affinity for iron, and thus it can cause intracellular iron loss. We tested the idea that intracellular iron can be the primary target of NO toxicity by comparing the signaling mechanisms involved in cell death caused by iron depletion and that caused by NO. Treatment of HL-60 cells with a NO donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), decreased the intracellular iron level rapidly as that observed with the iron chelator deferoxamine (DFO). Iron chelators such as DFO and mimosine could induce death of human leukemic HL-60 cells by a mechanism requiring activation of p38 kinase, c-Jun N-terminal kinase, caspase-3 and caspase-8. DFO and SNAP also caused release of cytochrome c from mitochondria. Inhibition of p38 kinase by a selective inhibitor, SB203580, abolished the NO and DFO-induced cell death, release of cytochrome c, and activation of caspase-3 and caspase-8, thus indicating that p38 kinase lies upstream in the cell death processes. In a parallel situation, the cells that are sensitive to NO showed similar sensitivity to DFO. Moreover, simultaneous addition of ferric citrate, an iron-containing compound, inhibited the SNAP and DFO-induced activation of caspases and also blocked the NO-mediated cell cycle arrest at $G_1$ phase. Collectively, our data implicate that the NO-induced cell death of tumor cells including HL-60 cells is mediated by depletion of iron and further suggest that activation of p38 kinase lies upstream of cytochrome c release and caspase activation involved in this apoptotic process.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.896-904
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• 2007

Regulation mechanism of apoptosis has been known to be important for understanding the pathogenesis of a number of human diseases including cancers. The effects of $RRR-{\alpha}-tocopheryl$ succinate(vitamin E succinate, VES) on the cell viability, generation of ROS, expression of proteins involved in apoptosis, and growth of human chronic myelogenous leukemia K562 cells were analyzed in this study. VES treatment not only induced the generation of the ROS but also increased the levels of $NF-{\kappa}B$, COX-2, and $p21^{WAF1/CIP1}$ in K562 cells. It modulates the levels of pro-apoptotic proteins such as Bax provoking the apoptosis in K562 cells. The cleavage of PARP into 89 kDa was also increased upon VES treatment in a dosage-dependent manner. Induction of an apoptosis was evident by the increase of sub-Gl peak and cell shrinkage condensed chromatin in K562 cells treated with VES. It also resulted in an inhibition of tumor growth by 50% and prolonged survival of the Iymphoma-induced mice. This potentiation of VES obtained in vitro and in vivo may indicate the feasibility of more effective chemotherapy in chronic myelogenous leukemia.

• Journal of Life Science
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• v.18 no.3
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• pp.336-343
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• 2008

Histone deacetylases (HDACs) inhibitors have emerged as the accessory therapeutic agents for various human cancers, since they can block the activity of specific HDACs, restore the expression of some tumor suppressor genes and induce cell differentiation, cell cycle arrest and apoptosis in vitro and in vivo. In the present study, we investigated that the effect of trichostatin A (TSA), an HDAC inhibitor, on the cell growth and apoptosis, and its effect on the nuclear factor-kappaB $(NF-{\kappa}B)$ activity in 267B1 human prostate epithelial cells. Exposure of 267B1 cells to TSA resulted in growth inhibition and apoptosis induction in and dose-dependent manners as measured by fluorescence microscopy, agarose gel electrophoresis and flow cytometry analysis. TSA treatment inhibited the levels of IAP family members such as c-IAP-1 and c-IAP-2 and induced the proteolytic activation of caspase-3, -8 and -9, which were associated with concomitant degradation of poly (ADP-ribose)-polymerase, ${\beta}-catenin$ and laminin B proteins. The increase in apoptosis by TSA was connected with the translocation of $NF-{\kappa}B$ from cytosol to nucleus, increase of the DNA binding as well as promoter activity of $NF-{\kappa}B$, and degradation of cytosolic inhibitor of KappaB $(I{\kappa}B)-{\alpha}$ protein. We therefore concluded that TSA demonstrated anti-proliferative and apoptosis-inducing effects on 267B1 cells in vitro, and that the activation of caspases and $NF-{\kappa}B$ may play important roles in its mechanism of action. Although further studies are needed, these findings provided important insights into the possible molecular mechanisms of the anti-cancer activity of TSA.

• Journal of Life Science
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• v.23 no.4
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• pp.471-478
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• 2013

Human adipose tissue-derived mesenchymal stem cells (hADSCs) have therapeutic potential, including the ability to self-renew and differentiate into multiple lineages. Understanding of molecular mechanisms of stem cell differentiation is important for improving the therapeutic efficacies of stem cell transplantation. In this study, we determined the role of nuclear factor of activated T cells (NFAT5) in the osteogenic differentiation of hADSCs. The down-regulation of NFAT5 expression by the transfection of a specific siRNA significantly inhibited osteogenic differentiation of hADSCs and decreased the activity of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$) promoter without affecting their proliferation and adipogenic differentiation. The inhibition of NFAT5 expression inhibited the basal and Tumor Necrosis Factor ${\alpha}$ (TNF-${\alpha}$) induced activation of NF-${\kappa}B$, but it did not affect TNF-${\alpha}$-induced degradation of the $I{\kappa}B$ protein. These findings indicate that NFAT5 plays an important role in the osteogenic differentiation of hADSCs through the modulation of the NF-${\kappa}B$ pathway.

• Journal of Life Science
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• v.26 no.9
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• pp.1082-1087
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• 2016

The intestinal tight junction (TJ) plays an important role as a paracellular barrier. Impaired TJ permeability and enhanced proinflammatory cytokine production are crucial pathophysiological mechanisms in inflammatory bowel diseases (IBDs). Although proinflammatory cytokines, tumor necrosis factor-alpha and interluekin-1 beta, which are markedly increased in IBD patients, have been reported to increase intestinal TJ permeability, the role of interleukin-1 alpha (IL-1α) in the TJ has not been studied. Phytochemicals could prevent proinflammatory cytokine-caused TJ alteration. Curcumin (CCM), a biologically active component of turmeric, has a strong anti-inflammatory activity. The purpose of this study was to elucidate the effect of IL-1α on intestinal epithelial TJ permeability and the role of CCM in IL-1α′s action on TJ in an in vitro intestinal epithelial system, Caco-2 monolayers. The TJ integrity of Caco-2 monolayers was estimated by measuring the flux of FITC-labeled dextran and transepithelial electrical resistance (TEER). Apical IL-1α (100 ng/ml) treatment elevated TJ permeability and suppressed TEER of Caco-2 monolayers. Pretreatment with CCM (20 μM) for 30 min significantly inhibited IL-1α-induced TJ alterations, such as increased TJ permeability and decreased in TEER values. These results demonstrated that IL-1α-induced increases in Caco-2 TJ permeability and CCM blocked the action of IL-1α in the TJ.

• Molecules and Cells
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• v.38 no.4
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• pp.327-335
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• 2015

Piperlongumine, a natural alkaloid isolated from the long pepper, selectively increases reactive oxygen species production and apoptotic cell death in cancer cells but not in normal cells. However, the molecular mechanism underlying piperlongumine-induced selective killing of cancer cells remains unclear. In the present study, we observed that human breast cancer MCF-7 cells are sensitive to piperlongumine-induced apoptosis relative to human MCF-10A breast epithelial cells. Interestingly, this opposing effect of piperlongumine appears to be mediated by heme oxygenase-1 (HO-1). Piperlongumine upregulated HO-1 expression through the activation of nuclear factor-erythroid-2-related factor-2 (Nrf2) signaling in both MCF-7 and MCF-10A cells. However, knockdown of HO-1 expression and pharmacological inhibition of its activity abolished the ability of piperlongumine to induce apoptosis in MCF-7 cells, whereas those promoted apoptosis in MCF-10A cells, indicating that HO-1 has anti-tumor functions in cancer cells but cytoprotective functions in normal cells. Moreover, it was found that piperlongumine-induced Nrf2 activation, HO-1 expression and cancer cell apoptosis are not dependent on the generation of reactive oxygen species. Instead, piperlongumine, which bears electrophilic ${\alpha},{\beta}$-unsaturated carbonyl groups, appears to inactivate Kelch-like ECH-associated protein-1 (Keap1) through thiol modification, thereby activating the Nrf2/HO-1 pathway and subsequently upregulating HO-1 expression, which accounts for piperlongumine-induced apoptosis in cancer cells. Taken together, these findings suggest that direct interaction of piperlongumine with Keap1 leads to the upregulation of Nrf2-mediated HO-1 expression, and HO-1 determines the differential response of breast normal cells and cancer cells to piperlongumine.

• Herbal Formula Science
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• v.23 no.2
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• pp.199-208
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• 2015

Objectives : In the present study, we investigated the effects of ethanol extract of Scutellaria baicalensis (EESB) on the progression of cell cycle in human renal cell carcinoma Caki-1 cells. Methods : The effects of EESB on cell growth and apoptosis induction were evaluated by trypan blue dye exclusion assay and flow cytometry, respectively. The mRNA and protein levels were determined by Western blot analysis and reverse transcription-polymerase chain reaction, respectively. Results : It was found that EESB treatment on Caki-1 cells resulted in a dose-dependent inhibition of cell growth and induced apoptotic cell death as detected by Annexin V-FITC staining. The flow cytometric analysis indicated that EESB resulted in G2/M arrest in cell cycle progression which was associated with the down-regulation of cyclin A expression. Our results also revealed that treatment with EESB increased the mRNA and proteins expression of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), without any noticeable changes in cyclin B1, Cdk2 and Cdc2. In addition, the incubation of cells with EESB resulted in a significant increase in the binding of p21 and Cdk2 and Cdc2. These findings suggest that EESB-induced G2/M arrest and apoptosis in Caki-1 cells is mediated through the p53-mediated upregulation of Cdk inhibitor p21. Conclusions : Taken together, these findings suggest that EESB may be a potential chemotherapeutic agent and further studies will be needed to identify the biological active compounds that confer the anti-cancer activity of S. baicalensis.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.229-234
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• 2015

Nafamostat mesilate (NM) is a serine protease inhibitor with anticoagulant and anti-inflammatory effects. NM has been used in Asia for anticoagulation during extracorporeal circulation in patients undergoing continuous renal replacement therapy and extra corporeal membrane oxygenation. Oxidative stress is an independent risk factor for atherosclerotic vascular disease and is associated with vascular endothelial function. We investigated whether NM could inhibit endothelial dysfunction induced by tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$ ). Human umbilical vein endothelial cells (HUVECs) were treated with TNF-${\alpha}$ for 24 h. The effects of NM on monocyte adhesion, vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) protein expression, p38 mitogenactivated protein kinase (MAPK) activation, and intracellular superoxide production were then examined. NM ($0.01{\sim}100{\mu}g/mL$) did not affect HUVEC viability; however, it inhibited the increases in reactive oxygen species (ROS) production and p66shc expression elicited by TNF-${\alpha}$ (3 ng/mL), and it dose dependently prevented the TNF-${\alpha}$ -induced upregulation of endothelial VCAM-1 and ICAM-1. In addition, it mitigated TNF-${\alpha}$ -induced p38 MAPK phosphorylation and the adhesion of U937 monocytes. These data suggest that NM mitigates TNF-${\alpha}$ -induced monocyte adhesion and the expression of endothelial cell adhesion molecules, and that the anti-adhesive effect of NM is mediated through the inhibition of p66shc, ROS production, and p38 MAPK activation.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.108-112
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• 2005

Antimicrobial and antitumor activities of Camellia sinensis L seed extracts were investigated. Seed extracts showed antifungal activities against Candida albicans IFO 1594 and Cryptococcus neoformans. Inhibition zone of 20 mm was shown by 70% ethanol extract against C. albicans IFO 1594 at 100 mg/mL. Antifungal activity of seed extract was not decreased by heating at 80 and $100^{\circ}C$ for 30 min or at $121^{\circ}C$ for 15 min, indicating heat-stability of seed component. Growth-inhibitory effects were observed in 70 and 10% of tumor cell line SK-OV-3 and normal ceil line NIH/3T3 at $50{\mu}g/mL$, respectively.

• KSBB Journal
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• v.30 no.4
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• pp.148-154
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• 2015

Onion (Allium cepa) is one of the flavonoids-rich materials in human diet and onion peel, which is the onion by-products, contains over 20 times more quercetin than the flesh. In this study, to examine the anti-inflammatory effects of onion peel hot water extract (OPHWE), the cell viability, nitric oxide (NO), pro-inflammatory cytokines, such as interluekin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and IL-$1{\beta}$, were measured using the murine macrophage cell line RAW 264.7 cells. The Balb/c mice were used for an in vivo acute toxicity test and ICR mice were used for measurement of inhibition effects of croton oil-induced mouse ear edema. As a result, NO levels decreased in a dose-dependent manner. The production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed by 38%, 41%, and 34% respectively, compared with that of the LPS only group, without any cytotoxicity. The edema formation in the ICR mouse ear was also reduced compared to that in control. Moreover, there were no mortalities occurred in mice administered 5,000 mg/kg body weight of OPHWE. These results suggest that OPHWE has considerable anti-inflammatory activities and can be regarded as a potent candidate material to treat inflammatory diseases.