• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3625-3630
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• 2013

Reactive oxygen species (ROS) are known to promote mesothelial carcinogenesis that is closely associated with asbestos fibers and inflammation. Epithelial to mesenchymal cell transition (EMT) is an important process involved in the progression of tumors, providing cancer cells with aggressiveness. The present study was performed to determine if EMT is induced by $H_2O_2$ in human malignant mesothelioma (HMM) cells. Cultured HMM cells were treated with $H_2O_2$, followed by measuring expression levels of EMT-related genes and proteins. Immunohistochemically, TWIST1 expression was confined to sarcomatous cells in HMM tissues, but not in epithelioid cells. Treatment of HMM cells with $H_2O_2$ promoted EMT, as indicated by increased expression levels of vimentin, SLUG and TWIST1, and decreased E-cadherin expression. Expression of stemness genes such as OCT4, SOX2 and NANOG was also significantly increased by treatment of HMM cells with $H_2O_2$. Alteration of these genes was mediated via activation of hypoxia inducible factor 1 alpha (HIF-$1{\alpha}$) and transforming growth factor beta 1 (TGF-${\beta}1$). Considering that treatment with $H_2O_2$ results in excess ROS, the present study suggests that oxidative stress may play a critical role in HMM carcinogenesis by promoting EMT processes and enhancing the expression of stemness genes.

• Natural Product Sciences
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• v.24 no.3
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• pp.148-154
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• 2018

Chronic oxidative stress due to the accumulation of reactive oxygen species (ROS) in neuronal cells ultimately leads to neurodegenerative diseases. The use of natural therapies for the prevention of ROS-induced cell damage and for the treatment of neurodegenerative disorders has shown promising results. In this study, we evaluated the neuroprotective effects of the ethyl acetate (EtOAc) fraction of A. okamotoanum against the hydrogen peroxide ($H_2O_2$)-induced oxidative stress in C6 glial cells. Results show that cell viability was decreased in cells incubated with $H_2O_2$, whereas the addition of EtOAc fraction treatments in such cells significantly increased viability. The EtOAc fraction showed the highest inhibitory activity against ROS production and it also decreased the expressions of inflammatory proteins including cyclooxygenase-2, inducible nitric oxide synthase and interleukin-$1{\beta}$. Furthermore, the EtOAc fraction inhibited apoptosis by regulating the protein expressions cleaved caspase -9, -3, poly ADP ribose polymerase, Bax and Bcl-2. Therefore, these results show that the EtOAc fraction of A. Okamotoanum exhibits neuroprotective effects against $H_2O_2$ induced oxidative damage by regulating the inflammatory reaction and apoptotic pathway.

• Biomolecules & Therapeutics
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• v.28 no.2
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• pp.152-162
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• 2020

Cerebral ischemia exhibits a multiplicity of pathophysiological mechanisms. During ischemic stroke, the reactive oxygen species (ROS) concentration rises to a peak during reperfusion, possibly underlying neuronal death. Recombinant human erythropoietin (EPO) supplementation is one method of treating neurodegenerative disease by reducing the generation of ROS. We investigated the therapeutic effect of PEGylated EPO (P-EPO) on ischemic stroke. Mice were administered P-EPO (5,000 U/kg) via intravenous injection, and middle cerebral artery occlusion (MCAO) followed by reperfusion was performed to induce in vivo ischemic stroke. P-EPO ameliorated MCAO-induced neurological deficit and reduced behavioral disorder and the infarct area. Moreover, lipid peroxidation, expression of inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), and cytokine levels in blood were reduced by the P-EPO treatment. In addition, higher activation of nuclear factor kappa B (NF-κB) was found in the brain after MCAO, but NF-κB activation was reduced in the P-EPO-injected group. Treatment with the NF-κB inhibitor PS-1145 (5 mg/kg) abolished the P-EPO-induced reduction of infarct volume, neuronal death, neuroinflammation, and oxidative stress. Moreover, P-EPO was more effective than EPO (5,000 U/kg) and similar to a tissue plasminogen activator (10 mg/kg). An in vitro study revealed that P-EPO (25, 50, and 100 U/mL) treatment protected against rotenone (100 nM)-induced neuronal loss, neuroinflammation, oxidative stress, and NF-κB activity. These results indicate that the administration of P-EPO exerted neuroprotective effects on cerebral ischemia damage through anti-oxidant and anti-inflammatory properties by inhibiting NF-κB activation.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.373-379
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• 2011

Paeoniae Radix Rubra is a preparation consisting of desiccated roots of Paeonia lactiflora PALL (belonging to Ranunculaceae). Paeoniae Radix Rubra is used as a medicinal herb in Asian countries to treat many diseases. Ethanol- or water-based extracts of Paeoniae Radix Rubra were prepared and tested on RAW 264.7 cells, a murine macrophage cell line. The expression of some pro-inflammatory proteins, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), extracellular signal-regulated kinase 1/2 (ERK1/2) and phosphorylated ERK1/2 was detected by Western blot analyses, while PGE2 expression was quantified by ELISA. Both the water and ethanol extracts of Paeoniae Radix Rubra suppressed LPS-induced nitric oxide (NO) production and exhibited cell toxicity in accordance with increased NO production. Also, both extracts reduced the expression of COX-2 and iNOS, and inhibited phosphorylation of ERK1/2 in LPS-stimulated RAW 264.7 cells. Extracts prepared from Paeoniae Radix Rubra contain anti-inflammatory agents that inhibit the iNOS and MAPK pathways.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.192-197
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• 1994

Pseudomonas fluorescens which is able to utilize malonate as a sole carbon source was found to contain a novel 60 kb plasmid, which encodes the genes for the proteins to assimilate malonate, including malonate decarboxylase and acetyl-CoA synthetase. The evidence is as follows: The Pseudomonas cured with mitomycin C was unable to grow on malonate-medium as well as it lost plasmid. The plasmid isolated from the Pseudomonas could be introduced into E. coli strain JM103 and DH1 by transformation. The transformed E. coli was able to grow on malonate-medium and could transmit its plasmid back to the cured P. fluorescens by conjugation. The existence of the plasmid in the transformed E. coli was confirmed by hybridization with a labeled probe prepared from 12 kb segment of the plasmid. Dot hybridization showed that the copy number of the plasmid in the transformed E. coli is at least 13 times higher than in the wild type P. fluorescens. The two key enzymes, malonate decarboxylase and acetyl-CoA synthetase, were inducible by malonate in the transformed E. coli.

• Journal of Microbiology and Biotechnology
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• v.24 no.2
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• pp.217-224
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• 2014

Chicken are considered as the most important source of human infection by Campylobacter jejuni, which primarily arises from contaminated poultry meats. However, the genes expressed in vivo of the interaction between chicken and C. jejuni have not been screened. In this regard, in vivo-induced antigen technology (IVIAT) was applied to identify expressed genes in vivo during interaction between chicken and C. jejuni, a prevalent foodborne pathogen worldwide. Chicken sera were obtained by inoculating C. jejuni NCTC 11168 into Leghorn chickens through oral and intramuscular administration. Pooled chicken sera, adsorbed against in vitro-grown cultures of C. jejuni, were used to screen the inducible expression library of genomic proteins from sequenced C. jejuni NCTC 11168. Finally, 28 unique genes expressed in vivo were successfully identified after secondary and tertiary screenings with IVIAT. The genes were implicated in metabolism, molecular biosynthesis, genetic information processing, transport, regulation and other processes, in addition to Cj0092, with unknown function. Several potential virulence-associated genes were found to be expressed in vivo, including chuA, flgS, cheA, rplA, and Cj0190c. We selected four genes with different functions to compare their expression levels in vivo and in vitro using real-time RT-PCR. The results indicated that these selected genes were significantly upregulated in vivo but not in vitro. In short, the expressed genes in vivo may act as potential virulence-associated genes, the protein encoded by which may be meaningful vaccine candidate antigens for campylobacteriosis. IVIAT provides an important and efficient strategy for understanding the interaction mechanisms between Campylobacter and hosts.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.249-257
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• 2002

Pseudomonas fluorescens GL20 is a plant growth-promoting rhizobacterium that produces a large amount of hydroxamate siderophore under iron-limited conditions. The strain GL20 considerably inhibited the spore germination and hyphal growth of a plant pathogenic fungus, Fusarium solani, when iron was limited, significantly suppressed the root-rot disease on beans caused by F. solani, and enhanced the plant growth. The mechanism for the beneficial effect of strain GL20 on the disease suppression was due to the siderophore production, evidenced by mutant strains derived from the strain. Analysis of the outer membrane protein profile revealed that the growth of strain GL20 induced the synthesis of specific iron-regulated outer membrane proteins with molecular masses of 85- and 90 kDa as the high-affinity receptors for the ferric siderophore. In addition, a cross-feeding assay revealed the presence of multiple inducible receptors for heterologous siderophores in the strain. In order to induce increased efficacy and potential in biological control of plant disease, a siderophore-overproducing mutant, GL20-S207, was prepared by NTG mutagenesis. The mutant GL20-S207 produced nearly 2.3 times more siderophore than the parent strain. In pot trials of beans with F. solani, the mutant increased plant growth up to 1.5 times compared with that of the parent strain. These results suggest that the plant growth-promoting P. fluorescens GL20 and the genetically bred P. fluorescens GL20-S207 can play an important role in the biological control of soil-borne plant diseases in the rhizosphere.

• Nutrition Research and Practice
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• v.8 no.3
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• pp.267-271
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• 2014

BACKGROUND/OBJECTIVES: Overproduction of nitric oxide (NO) by the inducible nitric oxide synthase (iNOS) enzyme can cause inflammation. Cyclooxygenase-2 (COX-2) is also involved in the inflammatory response through regulation of nuclear factor-kappa B $NF-{\kappa}B$(). Areca catechu is one of the known fruit plants of the Palmaceae family. It has been used for a long time as a source of herbal medicine in Indonesia. In this study, we explored the effect of Indonesian Areca catechu leaf ethanol extract (ACE) in lipopolysaccharide (LPS)-induced inflammation and carrageenan-induced paw edema models. Recently, this natural extract has been in the spotlight because of its efficacy and limited or no toxic side effects. However, the mechanism underlying its anti-inflammatory effect remains to be elucidated. MATERIALS/METHODS: We measured NO production by using the Griess reagent, and determined the expression levels of inflammation-related proteins, such as iNOS, COX2, and $NF-{\kappa}B$, by western blot. To confirm the effect of ACE in vivo, we used the carrageenan-induced paw edema model. RESULTS: Compared to untreated cells, LPS-stimulated RAW 264.7 cells treated with ACE showed reduced NO generation and reduced iNOS and COX-2 expression. We found that the acute inflammatory response was significantly reduced by ACE in the carrageenan-induced paw edema model. CONCLUSION: Taken together, these results suggest that ACE can inhibit inflammation and modulate NO generation via downregulation of iNOS levels and $NF-{\kappa}B$ signaling in vitro and in vivo. ACE may have a potential medical benefit as an anti-inflammation agent.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1162-1168
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• 2007

Although widely used as a host for recombinant protein production, Escherichia coli is unsuitable for massive screening of recombinant clones, owing to its poor secretion of proteins. A vector system containing T4 holin and T7 lysozyme genes under the control of the ptsG promoter derivative that is inducible in the absence of glucose was developed for programmed cell lysis of E. coli. Because E. coli harboring the vector grows well in the presence of glucose, but is lysed upon glucose exhaustion, the activity of the foreign gene expressed in E. coli can be monitored easily without an additional step for cell disruption after the foreign gene is expressed sufficiently with an appropriate concentration of glucose. The effectiveness of the vector was demonstrated by efficient screening of the amylase gene from a Bacillus subtilis genomic library. This vector system is expected to provide a more efficient and economic screening of bioactive products from DNA libraries in large quantities.

• The Korea Journal of Herbology
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• v.31 no.1
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• pp.25-31
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• 2016

Objectives : The present study was conducted to evaluate protective effects of Combined Extract of young persimmon fruit and citrus peel (PCM) in Reflux Esophagitis(RE) rats.Methods : Twenty-four Sprague-Dawley (SD) rats were divided four groups and each group had six rats ; Normal group, RE control group, RE group treated PCM 50 ,100 mg/kg body weight group. Reflux esophagitis was induced that tied the pylorus and fundus in SD rats stomach. PCM was administered at 50, 100 mg/kg body weight 2 hrs prior to induction of RE. After 6 hrs, the effects of PCM treated rats were compared with those of normal and control rats. We have performed an analysis such as pH of stomach secretion, oxidative stress biomarkers in serum, and western blot.Results : The increased esophageal mucosa damage by RE was markedly improved by PCM treatment in a dose-dependent manner. Also, the administration of PCM decreased the elevated serum reactive oxygen species (ROS) and peroxynitrite (ONOO^-) in serum. The protein expressions of anti oxidant such as SOD, catalase, GPx exhibited down-regulation by PCM treatment in tissues. And, PCM effectively reduce inflammatory cytokines such as inflammation-related proteins cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) in RE rats. In addition, NFκB and p-IκBɑ were decreased in PCM-adiministrated RE rats. But there was no difference on stomach secretion pH between reflux esophagitis rats and PCM administration rat group.Conclusions : In conclusion, administration of PCM (50, 100 mg/kg body weight) made esophagus have less inflammation and injury by decreased NFκB path way. These findings suggest that PCM could have Improving effects on reflux esophagitis.