• Mycobiology
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• v.45 no.4
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• pp.297-311
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• 2017

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of S. parasitica, supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated S. parasitica was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with S. parasitica, pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin $[IL]-1{\beta}$, tumor necrosis factor ${\alpha}$, IL-6, IL-8, interferon ${\gamma}$, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules ($CD8^+$ and $CD4^+$) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti-Saprolegnia agent, plant based lawsone was applied to investigate on the susceptibility of S. parasitica showing the minimum inhibitory concentration and percentage inhibition of radial growth as $200{\mu}g/mL$ and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of S. parasitica mycelium and caused irreversible damage and disintegration to the cellular membranes of S. parasitica. Transcriptional responses of the genes of S. parasitica mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti-S. parasitica agent for controlling S. parasitica infection.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.196-202
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• 2000

A gene for cellulolytic xylanase of Bacillus circulnns ATCC21365 was cloned on pUC 19 in Eschwichia coli. The recombinant plasniid pXLI80 contained an 1.8 id, inselt composed of0.5 kb and 1.3 kb PslI fragments derived from B, circulans. The 0.5 kh fragment in the upstream region of 1.3 kb one was confirmed lo be indispensable for not only expression but also hyperexpression of the cloned gene. The transformant overproduced the xylanase 135 times greater than that produced by the orlginal B circulnns. The optimum pH and temperature of the cloned enzyme we]-e pH 5.2 and $60^{\circ}C$, respectively. Heal pretl-eatment at TEX>$55^{\circ}C$C for 1 Indid not cause inhibition of the activity of this enzyme. The elm.ynie could hydl-olyre CMC and lichenan as well as xylan to produce xylose(or GI), xylohiose(or G2) and xylolnose(or G3) as inah products. Hence We defined the cloned enzyme as a cellulolytic xylanase. The SDS-PAG electrophoretic mobility and zyiiogram of this enzyme derived from whole cell extracts or c~~lture supematants or E. coli(pXL180) indicated a molecular weight of 45,000 and nonprocessing of the enzyme in the peilplasln of E. coli.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.431-437
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• 2011

Aberrant activation of microglia has been reported to cause neuronal damages by releasing a variety of pro-inflammatory cytokines. Besides where microglia become active, damages have been also observed in remote places, which is considered due to the migration of activated microglia. Therefore, an agent that could suppress abnormal activation of microglia and their subsequent migration might be valuable in activated microglia-related brain pathologies. The objective of the present study was to evaluate anti-inflammatory effects of betulinic acid on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Pretreatment of betulinic acid significantly attenuated LPS-induced NO production and protein expression of iNOS. Betulinic acid also significantly suppressed LPS-induced release and expression of cytokines such as TNF-${\alpha}$ and IL-$1{\beta}$. Furthermore, betulinic acid significantly uppressed LPS-induced MMP-9 expression, which has been suggested to play an important role in the migration of activated microglia. In order to understand the possible mechanism by which betulinic acid suppresses LPS-induced cytokine production and migration of microglia, the role of NF-kB, a major pro-inflammatory transcription factor, was examined. Betulinic acid significantly suppressed LPS-induced degradation of IKB, which retains NF-kB in the cytoplasm. Therefore, nuclear translocation of NF-kB upon LPS stimulation was significantly suppressed with betulinic acid. Taken together, the present study for the first time demonstrates that betulinic acid possesses anti-inflammatory activity through the suppression of nuclear translocation of NF-kB in BV2 microglial cells.

• Molecules and Cells
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• v.37 no.1
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• pp.66-73
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• 2014

Myeloid-derived suppressor cells (MDSCs) play an important role in impairing the function of T cells. We characterized MDSCs in two chronic hepatitis C (CHC) cohorts: a cross-sectional group that included 61 treatment-naive patients with CHC, 14 rapid virologic response (RVR) cases and 22 early virologic response (EVR) cases; and a longitudinal group of 13 cases of RVR and 10 cases of EVR after pegylated-interferon-${\alpha}$/ribavirin treatment for genotype 1b HCV infection. Liver samples from 32 CHC patients and six healthy controls were subjected to immunohistochemical analysis. MDSCs frequency in treatment-naive CHC was significantly higher than in RVR, EVR, or healthy subjects and was positively correlated with HCV RNA. Patients infected with HCV genotype 2a had a significantly higher frequency of MDSCs than those infected with genotype 1b. Decreased T cell receptor (TCR) ${\zeta}$ expression on $CD8^+$ T cells was significantly associated with an increased frequency of MDSCs in treatment-naive CHC patients and was restored by L-arginine treatment in vitro. Increased numbers of liver arginase-$1^+$ cells were closely associated with the histological activity index in CHC. The TCR ${\zeta}$ chain was significantly downregulated on hepatic $CD8^+$ T cells in CHC. During antiviral follow up, MDSCs frequency in peripheral blood mononuclear cells was directly correlated with the HCV RNA load in the plasma and inversely correlated with TCR ${\zeta}$ chain expression in $CD8^+$ T cells in both RVR and EVR cases. Notably, the RVR group had a higher frequency of MDSCs at baseline than the EVR group. Collectively, this study provides evidence that MDSCs might be associated with HCV persistence and downregulation of CD8 ${\zeta}$ chain expression.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.286-291
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• 2018

This study aimed to investigate the antioxidant ability of a cumin seeds ethanol extract (CE). The DPPH and ABTS radical scavenging activities of 0.25, 0.5, and 1.0 mg/mL of CE were found to be 24.6, 41.4, and 73.4 and 14.5, 27.2, and 50.1%, respectively (p<0.05), suggesting a dose-dependent effect. Moreover, the total phenolic content of CE was $61.0{\mu}M$ tannic acid equivalent/g extract and the FRAP value was $429{\mu}M$ ascorbic acid equivalent/g extract. In 9 hours of oil oxidation, CDA and ${\rho}-AV$ was significantly reduced to 13.4 and 59.1%, respectively, at a CE concentration of 100 ppm compared with that in the control (p<0.05). Major volatile compounds of CE were found to be ${\alpha}$-pinene, 2-butenal, cyclohexene, ${\beta}$-pinene, cis-sabinene, ${\rho}$-cymene, and limonene. These results suggest that CE containing volatile compounds has excellent antioxidant ability and oxidation stability, and thus could be used as a natural antioxidant to prevent oxidation in lipid foods.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.570-577
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• 2021

This study elucidated the biological activities and structural characteristics of polysaccharides isolated from ginseng leaves fermented using Cordyceps sinensis (GLF). GLF comprised at least 18 glycosyl linkages, including 4-linked glucose residues (24.0%). To characterize the neutral polysaccharides in GLF, it was further fractionated by anion exchange chromatography, and the unabsorbed fraction (GLF1) was isolated. Peritoneal macrophages stimulated with GLF1 produced various cytokines in a dose-dependent manner. The properties and activities of the four subfractions (PHI, PHIA1-PHIA3) obtained after sequential enzymatic digestion were examined. PHI and PHIA3 primarily comprised glucose, whereas PHI exhibited an iodine-color reaction. Furthermore, the PHIA1-3 fractions indicated that cytokine production was completely inhibited. These results suggest at the immune activities of GLF1 may be due to the α-(1→4)-glucan branched at the C(O)6 position, which was produced by C. sinensis.

• Journal of Life Science
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• v.28 no.12
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• pp.1455-1460
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• 2018

Due to a rapidly expanding aging population, the incidence of degenerative bone disease has increased, and efforts to handle the issue using regenerative medicine have become more important. In order to control various bone diseases such as osteoarthritis and osteoporosis, regenerative medicine utilizing adult stem cells has been extensively studied. And it is now clear that the mitochondrial energy metabolism, oxidative phosphorylation, is important for the process of stem cell differentiation. Interestingly, a recent study reported that salicylate promotes mitochondrial biogenesis by regulating the expression of $PGC-1{\alpha}$ in murine cells. However, the possible effects of salicylate on osteogenic differentiation through increased mitochondrial biogenesis in stem cells remain unknown. Thus, here we investigated whether salicylate could influence osteogenic differentiation and mitochondrial biogenesis of periosteum-derived mesenchymal stem cells (POMSCs). We found that salicylate treatments of POMSCs undergoing osteogenic differentiation increased the activity of alkaline phosphatase, a well-known early marker of bone cell differentiation. In addition, we observed that mitochondrial mass was increased by salicylate treatments in POMSCs. Together, these results indicate that salicylate can enhance osteogenic differentiation and mitochondrial biogenesis in POMSCs. Therefore, the findings in this study suggest that small molecules augmenting mitochondrial function such as salicylate can be a novel modulator for osteogenic differentiation and regenerative medicine.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.507-512
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• 2019

To study how illuminance affects cognitive ability of the elderly, the elderly's EEG, concentration, HRV and vibra image were measured in a test room with temperature $25[^{\circ}C]$, relative humidity 50[RH%] and air flow speed 0.02[m/sec] by varying illuminance to 100[lux], 300[lux], 600[lux], 1000[lux] and 1500[lux]. Ten active elderly males were selected as subjects. Experiment condition was fixed as 1met of activity amount where the subject is seated and relaxed with cloth amount of 0.7clo. As a result, 1000[lux] was found out to be the most pleasant illuminance for the elderly, because $M{\beta}$ increased by 66.35%, and $S{\alpha}$ increased by 31.57% when the elderly was under 1000[lux] of illuminance. Also, concentration under 1000[lux] increased by 8.83% compared to 100[lux], and the pattern of concentration maintained uniformly. SDNN increased by 74.94% under 1000[lux] compared to 100[lux]. Nervousness decreased by 97.23% under 1000[lux] compared to 100[lux]. Moreover, HRT notably increased and aggression remarkably decreased under illuminance of 1000[lux]. Thus, based on the fact that comfort, concentration and heart stability of the elderly reach the highest under 1000[lux], it is determined that the illuminance has to be considered foremost in designing the elderly's welfare facilities to raise their safety and level of independence.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.676-684
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• 2019

The Pictet-Spengler reactions have widely known for the organic synthesis or biosynthesis of biologically active compounds, tetrahydro-${\beta}$-carbolines. We have developed the simple and efficient synthetic method for the synthesis of ${\beta}$-carbolines in water. Their chemical structures were characterized by nmr and UPLC/MS/QTOF. Calculated masses of compound 1 ($C_{17}H_{17}N_2$ 249.1392), 2 ($C_{17}H_{23}N_2$ 255.1861), 3 ($C_{19}H_{21}N_2O_3$ 325.1552) and 4 ($C_{19}H_{19}N_2O$ 279.1497) were almost identical with the detected masses of compound 1 (249.1315), 2 (255.1789), 3 (325.1460) and 4 (279.1364) respectively. Those synthesized four compounds showed strong antibiotic activity against the common E. coli.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.377-384
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• 2018

This study focused on the effects of feeding on postlarvae of shrimp, Litopenaeus vannamei, during the identified acclimation time to low salinity. A total of 5 different salinity groups with or without feeding (32, 24, 16, 8, and 2 psu, 1 liter, triplicates) were prepared, and 30 shrimp were settled at PL21 (postlarvae) and placed in each group. After 24 hours of the experimentation process, the survival rate of the fed and starved groups was observed to be lower in the 2 psu group compared to other salinity groups, with the rate of 86.6% and 81.1%, respectively. The condition index of glucose and triglyceride, which are important factors for osmoregulation and as energy sources, was 4.2-7.6 times and 2.7-3.4 times higher in the fed groups than the starved groups at all the levels of salinities. The creatine level increased by 1.1-1.5 times in the starved groups as compared to the fed groups. Likewise, the activity of all the digestive enzymes like, lipase, ${\alpha}$-amylase, trypsin, and alkaline protease were clearly higher in the fed groups (ANOVA, p<0.05). Apparently, it was observed that feeding is effective for the postlarvae of shrimp, which shows a characteristic fast metabolism and larval development, during the acclimation period to low salinity.