• Korean Journal of Ecology and Environment
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• v.41 no.1
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• pp.81-89
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• 2008

The eco-toxicological effects of endocrine disrupter, 4-nonylphenol (4NP) were observed and detected on the harpacticoid copepod, Tigriopus japonicus s.l. obtained and cultur-ed from our coast. There were no significant differences survival rate, sex ratio, and fecundity on T. japonicus s.l. at as low as $30{\mu}gL^{-1}$ of 4 NP exposure. Whereas, 4NP induced developmental delay, decreasing biomass and body size of nauplius and copepodite. Also, Differentially Expressed Gene (DEG) was conducted to detecting gene expression for potential biomarkers response to 4NP. As a result, full lifecycle research on morphology and gene expression of T. japonicus s.l. suggested potential bioindicators or biomarkers for environmental monitoring and assessments.

• Journal of Life Science
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• v.26 no.1
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• pp.17-22
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• 2016

Ethanol is a very valuable material, however, it is also a source of stress, as the accumulation of ethanol in a medium inhibits cell viability and decreases productivity of the target product. Therefore, the ethanol tolerance of yeast, which is closely related to ethanol productivity, is an important factor in industrial ethanol production. In this study, the YDJ1 and PEP5 genes were selected as target genes for elucidating ethanol-tolerant mechanisms by analyzing the expression regulation of these genes. The pA-YDJ1 and pA-PEP5 plasmids containing YDJ1 and PEP5 genes under an ADH1 promoter, respectively, were constructed and transformed into BY4742 (host strain), BY4742△ydj1, and BY4742△pep5 strains. The ethanol tolerance in the BY4742△ydj1/ pA-YDJ1 and BY4742△pep5/pA-PEP5 transformants was restored by overexpression of the YDJ1 and PEP5 genes to the host strain level. The YDJ1 and PEP5 genes were also introduced into the double gene disruptant (BY4742△ydj1△pep5) to investigate the expression regulation of the YDJ1 and PEP5 genes. The simultaneous overexpression of the YDJ1 and PEP5 genes restored ethanol tolerance to the 90% level of the BY4742 strain under 8% ethanol stress. The YDJ1 gene induced more overexpression of the PEP5 gene in the BY4742△ydj1 △pep5/pA-YDJ1, pA-PEP5 strain, suggesting that the YDJ1 gene partially regulates the expression of the PEP5 gene as an upstream regulator.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.320-329
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• 2023

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg^-1 Cd, 96% at 1.87 mg kg^-1 Cd, and 93% at 6.09 mg kg^-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg^-1, 13.06 mg kg^-1, and 79.11 mg kg^-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg^-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

• Journal of Life Science
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• v.30 no.2
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• pp.113-121
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• 2020

Macrophages are initiators for regulating a host's defenses to eliminate pathogens and trigger tissue repair. Macrophages are classified into two types: classically (M1) activated macrophages and alternatively (M2) activated macrophages. M1-phenotype macrophages directly or indirectly kill infectious organisms and tumor cells via pro-inflammatory responses, whereas M2-phenotype macrophages remodel wounded tissue through anti-inflammatory responses. In this paper, we investigated how Phellinus linteus hot water extract passed from Diaion HP-20 resin (PLEP) regulates polarization of M1-like or M2-like macrophages in human THP-1 cells. PLEP did not have cytotoxicity at a high concentration of 300 ㎍/ml. We observed morphological alteration of the THP-1 cells, which are stimulated by PLEP, LPS/INF-γ (M1 stimulators) or IL-4/IL13 (M2 stimulators). PLEP exposure induced morphology contiguous with LPS/INF-γ. qPCR was also performed to determine whether PLEP influences M1 or M2 polarization-related genes. M1-phenotype macrophage-specific genes, such as TNF-α, IL-1β, IL-6, IL-8, CXCL10 and CCR7, were enhanced by PLEP in a dose-dependent manner similar to LPS/INF-γ. Conversely, M2-phenotype-specific genes, such as MRC-1, DC-SIGN, CCL17 and CCL22, were suppressed by PLEP. PLEP also significantly up-regulated secretory inflammation cytokines related to M1 polarization of macrophages, including TNFα, IL-1β and IL-6, which was similar to the gene expression. Further, MAPK and NF-κB signaling were increased by treatment with PLEP, resulting in enhancement of cytokine secretion. PLEP might therefore be used as a promising booster of pro-inflammatory responses through M1 polarization of human THP-1 cells.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.636-644
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• 1999

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. The mechanisms of TNF cytotoxicity are not clearly understood and some has reported that reactive oxygen species(ROS) might be associated with them, but there is controversy about antioxidant effect on TNF cytotoxicity. This study was designed to compare the TNF cytotoxicity after antioxidant pretreatment with that of control to evaluate the role of ROS in the mechanism of TNF cytotoxicity. Method : We compared the TNF cytotoxicies to WEHI164(murine fibrosarcoma cell line) and ME180(human cervix cancer cell line) after antioxidant pretreatment with those of control by MIT(dimethylthiazolyl-diphenyltetrazolium bromide) assay. Results : In the control group, the TNF cytotoxicities were $92.2{\pm}2.8%$(WEHI164) and $59.9{\pm}7.0%$(MEl80). In the TMTU(tetramethyl thiourea) pretreatment group, those were $91.4{\pm}3.7%$ and $74.6{\pm}7.0%$. In the PMZ(promethazine) pretreatment group, those were $90.2{\pm}2.5%$ and $62.5{\pm}5.7%$. In the BHT(butylated hydroxytoluene) pretreatment group, those were $93.2{\pm}1.3%$ and $66.3{\pm}6.1%$. So there was no reduction in TNF cytotoxicity after antioxidants pretreatment. Conclusion : The ROS may not have major role in the mechanisms of TNF cytotoxicity.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.413-419
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• 2016

Ryanodine receptors (RyRs) regulate the contractions of insect muscles by altering intracellular $Ca^{2+}$ concentration and are the targets of chlorantraniliprole. Recently, a chlorantraniliprole-resistant strain was reported in the diamondback moth Plutella xylostella by obtaining point mutations on the RyRs. In the present study, we established two resistant strains from Drosophila melanogaster, which were treated with low or high concentrations of chlorantraniliprole, and their resistance levels were determined on the basis of contact and ingestion toxicities. Compared with the control strain, the two resistant strains did not show any significant differences in contact toxicity. However, they showed significantly increased resistance ratios in ingestion toxicity than that by the control strain. The low and high concentration resistant strains exhibited 2.1- and 8.1-fold increased resistance ratios, respectively, compared with that by the control strain. Moreover, we found that the resistant strains had altered expression levels of RyRs and more enhanced Acetylcholinesterase and Glutathione-S-transferase activities than that by the non-selected strain. These results suggested that the resistance development of chlorantraniliprole in the two strains might be mediated by the activation of detoxification pathways in D. melanogaster.

• Journal of Life Science
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• v.27 no.1
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• pp.67-71
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• 2017

Foulbrood disease is infected by Paenibacillus larvae on larval stage of honeybee, and is lethal disease to result in population death. This disease was manifested in 2008 in Korea, is still suffered by the secondary damages. In this study, we are to examine diagnostic PCR approaches to manage the Foulbrood disease. PCR amplification of 16S rRNA is generally using for microbial infection, but the specificity is little poor for the correct diagnosis. Therefore, we are to identify specific genes expressed in Paenibacillus larvae, and perform PCR analysis. We selected five distinct genes from literature references. Those genes are commonly known as toxic genes for host infection, and include Toxin1, Toxin2A & 2B, SplA, CBP49, and SevA&SevB. PCR amplification for these genes is difficult to detect at the first time. So, we performed the second PCR using the first PCR product as a template. This approach using the nested PCR was very useful for detecting large marker genes. When Paenibacillus larvae was cultured in the medium containing plant extracts, PCR amplification of the identified genes is correlated with the microbial growth inhibition. Therefore, these results suggest that the identified genes might be useful to study diagnostic PCR markers for honeybee Foulbrood disease.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.30-38
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• 2008

Dental pulp cells are assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. The purpose of this study is to examine the effects of mineral trioxide aggregate (MTA) on various gene expression regarding dentinogenesis and cell viability assay in cultured primary human dental pulp cells. The author also examined the effects of this material on cellular alkaline phosphatase activity as a potential indicator of dentinogenesis. For gene expression on MTA, reverse transcriptase polymerase chain reaction was performed using primer sets of glyceraldehyde-3-phosphate dehydrogenase, type I collagen, alkaline phosphatase(ALP), osteonectin, and dentin sialoprotein after 2 and 4 days. Cell viability assay showed that the proportion of MTA-treated pulp cells which had been exposed for 5 days to MTA was higher than that of the control cells. Among the genes investigated in this study, ALP and osteonectin(SPARC) were increased in MTA treated group than in control. These findings suggest that this dental pulp culture system may be useful in the future as a model for studying the mechanisms underlying dentin regeneration after the treatment with MTA. Exposure to MTA material would not induce cytotoxic response in the dental pulp cells. In addition, MTA could influence the behavior of human pulp cells by increasing the ALP activity and SPARC synthesis.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.165-172
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• 2020

Heavy metals are common pollutants in the freshwater environment and have toxicological effect in habitat organisms. The heavy metals highly accumulated in sediment and organism, and observed various physiological responses. In this study, we investigated the molecular response to heavy metal toxicity (Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) through expression of heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450 (CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP). HSPs showed up-regulation in Cu and Zn exposures. Furthermore, HSPs expression in treated groups tended to be higher than the control group. The tendency of CYP450 and GST mRNA expression was higher for Cr and Cu than for other exposure group. The expression of SP gene was low at Al exposure and other group were measured to be similar to control. These results suggest that heavy metal toxicity in freshwater ecosystem may affect physiological and molecular process. Also, the comprehensive gene expression in the aquatic midge Chironomus riparius give useful information to potential molecular biomarkers for assessing heavy metal toxicity.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.531-538
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• 2009

Xylitol has the ability to reduce the adherence of Streptococcus mutans(S. mutans), which can make it easier to remove plaque, decrease acid production and inhibit dental caries. There are few reports on the effects of xylitol on the expression of the virulence related genes in S. mutans. This study examined the inhibitory effect of chewing gum containing xylitol on glucan synthesis related gene expression of S. mutans. Participants were voluntarily recruited for a women's oral health prevention program, classified into two groups(a control and a xylitol group), and then followed for 2 years. Twenty salivary samples were randomly selected from each group. Colony count and real-time reverse transcription polymerase chain reaction were used to analyze the characteristics of S. mutans. The following results were obtained: The S. mutans counts decreased steadily in the xylitol group over the study period(p<0.05). The expression of the virulence related genes (gtfB, gtfC and gtfD) was significantly lower in the xylitol group than in the control groups (p<0.05). In conclusion, these results suggest that chewing xylitol gum for a long period of time may reduce the expression of the genes associated with S. mutans virulence, which can result in a decrease growth of S. mutans colonies as a result.