• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1125-1131
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• 2014

Background: Schistosomiasis is a parasitic disease causing chronic ill health in humans with a serious consequences for socio-economic development in tropical and subtropical regions. There is also evidence linking Schistosoma mansoni to colonic carcinoma occurrence. The aim of this study was to evaluate some inflammatory and oxidative stress biomarkers, as well as L-fucose as linkers between intestinal schistosomiasis and colonic dysplasia development in mice. Materials and Methods: This study was conducted upon 80 mice that were divided the control group (10 non infected mice) and infected group which was subdivided into 7 sub-groups (10 mice each) according to the time of sacrifaction in the post infection (p.i.) period, 10 mice being sacrificed every two weeks from 6 weeks p.i. to 18 weeks p.i. Tumor necrosis factor alpha (TNF-${\alpha}$), inducible nitric oxide synthase (iNOS), and pentraxin 3 (PTX3) levels were estimated by immunoassay. The L-fucose level, and thioredoxin reductase (TrxR) and lactate dehydrogenase (LDH) activities were also evaluated in colonic tissue. Results: The current study revealed statistically significant elevation in the studied biochemical markers especially at 16 and 18 weeks p.i. The results were confirmed by histopathological examination that revealed atypical architectural and cytological changes in the form of epithelial surface serration and nuclear hyper-chromatizia at 14, 16 and 18 weeks p.i. Conclusions: inflammation, oxidative stress and L-fucose together may form an important link between Schistosomal mansoni infection and colonic dysplasia and they can be new tools for prediction of colonic dysplasia development in experimental schistosomiasis.

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.55-61
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• 2016

Antioxidant effects and nuclear factor E2-related factor-2 (Nrf-2) signal pathway of methanol extract and 4 fractions [n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions] from Petasites japonicus were investigated. The EtOAc fraction showed highest polyphenol and flavonoid contents among other fractions. In addition, EtOAc fraction showed stronger scavenging activity against superoxide anion radical than other fractions. Furthermore, we investigated antioxidants effects of the EtOAc fraction under cellular system using $LLC-PK_1$ cells. The EtOAc fraction dose-dependently increased the antioxidant protein expressions of heme oxygenase 1 (HO-1) and thioredoxin reductase 1 (TrxR1) known to be involved in oxidative stress, through activation of Nrf-2. The treatment of EtOAc fraction ($100{\mu}g/mL$) led to the elevation of the high expression of Nrf-2-dependent factor such as HO-1 and TrxR1. These results indicated that the EtOAc fraction of P. japonicus showed high antioxidant activity by regulation of Nrf-2 signaling pathway.

• Journal of Life Science
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• v.28 no.4
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• pp.454-464
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• 2018

Black soybeans are used as food sources as well as for traditional medicines because they contain an abundance of natural phenolic compounds. In this study, total phenolic contents (TPCs) of Korean black seed coat soybean varieties Socheongja (SCJ), Socheong 2 (SC2) and Cheongja 2 (CJ2) as well as their antioxidant capacities were investigated. Among them, TPCs were abundantly present in the order of CJ2$H_2O_2$-stimulated HaCaT human keratinocytes. Our results revealed that treatment with SCJ and SC2 prior to $H_2O_2$ exposure significantly increases the viability of HaCaT cells, indicating that the exposure of HaCaT cells to SCJ and SC2 conferred a protective effect against oxidative stress. SCJ and SC2 also effectively inhibited $H_2O_2$-induced apoptotic cell death through the blocking of mitochondrial dysfunction. SCJ and SC2 also attenuated the phosphorylation of Histone H2AX. Furthermore, they effectively induced the levels of thioredoxin reductase (TrxR) 1, a potent antioxidant enzyme, which is associated with the induction of nuclear transcription factor erythroid-2-like factor 2 (Nrf2); however, the protective effects of SCJ and SC2 were significantly reversed by Auranofin, a TrxR inhibitor. These results indicate that they have protective activity through the blocking of cellular damage related to oxidative stress via the Nrf2 signaling pathway. In conclusion, our study indicated that SCJ and SC2 might potentially serve as novel agents for the treatment and prevention of skin disorders caused by oxidative stress.

• Molecules and Cells
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• v.43 no.2
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• pp.182-187
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• 2020

When cells are stimulated by growth factors, they make a critical choice in early G₁ phase: proceed forward to S phase, remain in G₁, or revert to G₀ phase. Once the critical decision is made, cells execute a fixed program independently of extracellular signals. The specific stage at which the critical decision is made is called the restriction point or R-point. The existence of the R-point raises a major question: what is the nature of the molecular machinery that decides whether or not a cell in G₁ will continue to advance through the cell cycle or exit from the cell cycle? The R-point program is perturbed in nearly all cancer cells. Therefore, exploring the nature of the R-point decision-making machinery will provide insight into how cells consult extracellular signals and intracellular status to make an appropriate R-point decision, as well into the development of cancers. Recent studies have shown that expression of a number of immediate early genes is associated with the R-point decision, and that the decision-making program constitutes an oncogene surveillance mechanism. In this review, we briefly summarize recent findings regarding the mechanisms underlying the context-dependent R-point decision.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.4
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• pp.263-275
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• 2022

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, II-III, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.93-97
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• 2014

Subolesin (4D8), the ortholog of insect akirins, is a highly conserved protective antigen and thus has the potential for development of a broad-spectrum vaccine against ticks and mosquitoes. To date, no protective antigens have been characterized nor tested as candidate vaccines against Dermacentor silvarum bites and transmission of associated pathogens. In this study, we cloned the open reading frame (ORF) of D. silvarum 4D8 cDNA (Ds4D8), which consisted of 498 bp encoding 165 amino acid residues. The results of sequence alignments and phylogenetic analysis demonstrated that D. silvarum 4D8 (Ds4D8) is highly conserved showing more than 81% identity of amino acid sequences with those of other hard ticks. Additionally, Ds4D8 containing restriction sites was ligated into the pET-32(a+) expression vector and the recombinant plasmid was transformed into Escherichia coli rosetta. The recombinant Ds4D8 (rDs4D8) was induced by isopropyl ${\beta}$-D-thiogalactopyranoside (IPTG) and purified using Ni affinity chromatography. The SDS-PAGE results showed that the molecular weight of rDs4D8 was 40 kDa, which was consistent with the expected molecular mass considering 22 kDa histidine-tagged thioredoxin (TRX) protein from the expression vector. Western blot results showed that rabbit anti-D. silvarum serum recognized the expressed rDs4D8, suggesting an immune response against rDs4D8. These results provided the basis for developing a candidate vaccine against D. silvarum ticks and transmission of associated pathogens.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.403-409
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• 2010

Saccharomyces cerevisiae Hsp30 is a plasma membrane heat shock protein that is induced by various environmental stress conditions. However, the functional role of Hsp30 during diverse environmental stressors is not presently known. To gain insight into its function during thermal stress, we have constructed and characterized a ${\Delta}hsp30$ strain during heat stress. $BY4741{\Delta}hsp30$ cells were found to be more sensitive compared with BY4741 cells, when exposed to a lethal heat stress at $50^{\circ}C$. When budding yeast is exposed to either heat shock or weak organic acid, it inhibits Pma1p activity. In this study, we measured the levels of Pma1p in mutant and Wt cells both during optimal temperature and heat shock temperature. We observed that $BY4741{\Delta}hsp30$ cells showed constitutive reduction of Pma1p. To gain further insights into the role of Hsp30 during heat stress, we compared the total protein profile by 2D gel electrophoresis followed by identification of differentially expressed spots by LC-MS. We observed that contrary to that expected from thermal-stress-induced changes in gene expression, the ${\Delta}hsp30$ mutant maintained elevated levels of Pdc1p, Trx1p, and Nbp35p and reduced levels of Atp2p and Sod1p during heat shock. In conclusion, Hsp30 is necessary during lethal heat stress, for the maintenance of Pma1p and a set of thermal stress response functions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.1
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• pp.23-30
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• 2024

This paper dedcribes the design. verification, and analysis techniques for an advanced phased array antenna. When applying an active phased array antenna to an aircraft or missile, miniaturization of the array antenna and wide-angle beam steering characteristics can be unavoidable antenna design considerations. In particular, the active reflection coefficient characteristics when electronically steering a wide-angle beam is a design parameter that must be minimized in terms of system survival and system performance. As a radiator suitable for broadband characteristics and wide-angle beam steering, this paper designed an array structure using SFN and minimized the active reflection coefficient according to beam steering of up to 40° based on the spherical coordivate system angle. The bandwidth of the radiator was confirmed to be 3GHz based on active reflection in the Ka-band. In addition, the performance of the actually manufactured 8by8 array antenna wsa analyzed by measuring the single pattern of the radiator through a near-field test, mathematically synthesizing it, and predicting the Tx/TRx beam used in the seeker system.

• KSBB Journal
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• v.23 no.3
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• pp.205-212
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• 2008

The efficient soluble expression of human epidermal growth factor (hEGF) was achieved by using functional fusion partners in cytoplasm and periplasm of Escherichia coli (E. coli). hEGF was over-expressed in inactive inclusion body form in cytoplasm of E. coli due to improper disulfide bond formation and hydrophobic interaction, yielding about 5.9 mg/L in flask culture. Six functional fusion partners were introduced by linking to N-terminal part of hEGF gene for the high-level expression of soluble and active hEGF in cytoplasm and peri plasm region. Three fusion partners for cytoplasmic expression such as acidic tail of synuclein (ATS), thioredoxin (Trx) and lipase, and three fusion partners for periplasmic expression such as periplasmic cystein oxidoreductases (DsbA and DsbC) and maltose binding protein (MBP) were investigated. hEGF fused with ATS and DsbA showed over 90% of solubility in cytoplasm and periplasm, respectively. Especially DsbA was found to be an efficient fusion partner for soluble and high-level expression of hEGF, yielding about 18.1 mg/L and three-fold higher level compared to that of insoluble non-fusion hEGF in cytoplasm. Thus, heterologous proteins containing complex disulfide bond and many hydrophobic amino acids can effectively be produced as an active form in E. coli by introducing a suitable peptide or protein.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.433-441
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• 2013

In this study, the anti-oxidative, anti-inflammatory, anti-melanogenic activities of Endlicheria anomala (Nees) Mez methanol extract (EAME) were evaluated by use of in vitro assays and cell culture model systems. The results revealed that EAME scavenges various radicals such as 1,1-diphenyl-2-picryl hydrazyl hydrogen peroxide induced reactive oxygen species, and lipopolysaccharide induced nitric oxide. Furthermore, EAME induced the expression of anti-oxidative enzymes such as heme oxygenase 1, thioredoxin reductase 1, NAD(P)H dehydrogenase 1, and their upstream transcription factor, nuclear factor-E2-related factor 2. Moreover, EAME inhibited in vitro DOPA oxidation and 3-isobutyl-1-methylxanthine induced melanogenesis in B16F10 cells. Its anti-melanogenic activity will have originated from the inhibition of tyrosinase enzyme activity and melanogenesis related protein expression. Taken together, these results provide the important new insight that E. anomala possesses various biological activities such as anti-oxidative, anti-inflammatory, and anti-melanogenic. Therefore, it might be utilized as a promising material in the fields of nutraceuticals and cosmetics.