• Environmental Mutagens and Carcinogens
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• v.20 no.1
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• pp.34-39
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• 2000

Although shipbuilding workers were exposed to a variety of genotoxic compounds including polycyclic aromatic hydrocarbons (PAHs), limited number of studies were conducted to evaluate the biomarkers related to PAH exposure in painting workers in shipbuilding industry. One hundred and thirty three workers including 73 employees using coal tar paints were recruited from a shipbuilding company located in South Korea. Urinary 1-hydroxypyrene glucuronide (1-OHPG), as internal dose of PAH exposure, were measured by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11. Glutathione S-transferase (GST)M1 and GSTT1 genotypes were assessed by multiplex PCR. Information on demographic characteristics, smoking gabit, diet, job title, use of personal protective equipments were collected by self-administered questionnaire. Urinary 1-OHPG were higher in workers using coal tar paints than in workers using general paints, however, the difference was not statistically significant (p=0.20, Mann-Whitney U test). Urinary 1-OHPG levels in smokers were higher than in non-smokers (p<0.05 by Mann-Whitney U test) and there was a significant increase in urinary 1-OHPG levels with the numbers of cigarettes consumed per day (Spearman's correlation coefficient = 0.28, p=0.02). Genetic polymorphisms of GSTM1 and GSTT1 did not influence the level of 1-OHPG in study subjects. Multiple regression analysis show that smoking is the only significant predictor for lon-transformed 1-OHPG (overall model R2=0.1). These results suggest that workers using coal tar paints were exposed to significant amount of PAHs and individual difference in xenobiotic metabolism might affect the levels of internal dose of PAHs.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.267-282
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• 2000

Cytochrome P45O (CYP) 2E1 catalyzes the metabolism of a wide variety of therapeutic agents, procarcinogens, and low molecular weight solvents. CYP2E1-catalyzed metabolism may cause toxicity or DNA damage through the production of toxic metabolites, oxygen radicals, and lipid peroxidation. CYP2E1 also plays a role in the metabolism of endogenous compounds including fatty acids and ketone bodies. The regulation of CYP2E1 expression is complex, and involves transcriptional, post-transcriptional, translational, and post-translational mechanisms. CYP2E1 is transcriptionally activated in the first few hours after birth. Xenobiotic inducers elevate CYP2E1 protein levels through both increased translational efficiency and stabilization of the protein from degradation, which appears to occur primarily through ubiquitination and proteasomal degradation. CYP2E1 mRNA and protein levels are altered in response to pathophysiologic conditions by hormones including insulin, glucagon, growth hormone, and leptin, and growth factors including epidermal growth factor and hepatocyte growth factor, providing evidence that CYP2E1 expression is under tight homeostatic control.

• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.94-95
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• 1999

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.76-76
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• 2003

Oxidative stress is considered to be associated with many diseases, such as inflammatory and cardiovascular diseases, aging, and cancer. An important etiological mechanism of these diseases may be a causal relationship between the presence of oxidants and the generation of lipid hydroperoxides derived from enzymatic reactions or xenobiotic metabolism. (omitted)

• Toxicological Research
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• v.7 no.2
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• pp.191-208
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• 1991

Pulmonary conjugation pathways may be important for the metabolism of xenobiotics introduced via airways of systemically. The objective of this study was to determine the pulmonary conjugating capacity in both the isolated perfused rabbit lung (IPRL) and in vitro, and the ability of ethanol to alter the above. The IPRL was capable of conjugating glutathione (GSH) with either 1-chloro-2,4-dinitrobenzene (CDNB) of 1,2-epoxy-(p-nitrophenoxy) propane(ENP). The pulmonary GSH conjugation with ENP was inhibited by cibacron blue, indicating the presence of glutathione-S-transferase (GST) u and/or classes, but it was not altered by buthionine sulfoximine, a selective inhibitor of Gamma-glutamylcysteine synthetase.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.303-311
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• 2002

This study evaluated the concentrations of urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) in industrial waste incineration workers. The effect of genetic polymorphisms of xenobiotic metabolism enzymes on urinary concentration of PAH metabolites was assessed. And, aromatic DNA adduct levels were also determined in total white blood cells. Fifty employees were recruited from a company handling industrial wastes located in Ansan, Korea: non-exposed group (n=21), exposed group (n=29). Sixteen ambient PAHs were determined by GC/MSD (NIOSH method) from personal breathing zone samples of nine subjects near incinerators. Urinary 1-hydroxypyrene glucuronide (1-OHPG), a major pyrene metabolite, was assayed by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11 (SFS/IAC). Multiplex PCR was used for genotyping for GSTMI/TI and PCR-RFLP for genotyping of CYP1A1 (MspI and Ile/Val). PAH-DNA adducts in peripheral blood WBC were measured by the nuclease P1-enhanced postlabeling assay. Smoking habit, demographic and occupational information were collected by self-administered questionnaire. The range of total ambient PAH levels were 0.00-7.00 mg/㎥ (mean 3.31). Urinary 1-OHPG levels were significantly higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs (p=0.006, by Kruskal-Wallis test). There was a statistically significant dose-response increase in 1-OHPG levels with the number of cigarettes consumed per day (Pearson correlation coefficient=0.686, p<0.001). Urinary 1-OHPG levels in occupationally exposed smoking workers were highest compared with non-occupationally exposed smokers (p=0.053, by Kruskal-Wallis test). Smoking and GSTMI genotype were significant predictors for log-transformed 1-OHPG by multiple regression analysis (overall model R²=0.565, p<0.001), whereas smoking was the only significant predictor for log-transformed aromatic DNA adducts (overall model R²=0.249, p=0.201). Aromatic DNA adducts was also a significantly correlation between log transferred urinary 1-OHPG levels (pearson's correlation coefficient=0.307, p=0.04). However, the partial correlation coefficient adjusting for Age, Sex, and cigarette consumption was not significant (r=0.154, p=0.169). The significant association exists only in individuals with the GSTMI null genotype (pearsons correlation coefficient=0.516, p=0.010; partial correlation coefficient adjusting for age, sex, and cigarette consumption, r=0.363, p=0.038). Our results suggest that the significant increase in urinary 1-OHPG in the exposed workers is due to higher prevalence of smokers among them, and that the association between urinary PAH metabolites and aromatic DNA adducts in workers of industrial waste handling may be modulated by GSTMI genotype. There results remain to be confirmed in future larger studies.

• Journal of Life Science
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• v.30 no.2
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• pp.211-220
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• 2020

The activity of CAR can be regulated not only by ligand binding but also by phosphorylation of regulatory factors involved in extracellular signaling pathways, cross-talk interactions with transcription factors, and the recruitment, degradation, and expression of coactivators and corepressors. This regulation of CAR activity can in turn have effects on the control of diverse physiological homeostasis, including xenobiotic and energy metabolism, cellular proliferation, and apoptosis. CAR is phosphorylated by the ERK1/2 signaling pathway, which causes formation of a complex with Hsp-90 and CCRP, leading to its cytoplasmic retention, whereas phenobarbital inhibits ERK1/2, which causes dephosphorylation of the downstream signaling molecules, leading to the recruitment to CAR of the activated RACK-1/PP2A components for the dephosphorylation, nuclear translocation, and the transcriptional activation of CAR. Activated CAR cross-talks with FoxO1 to induce inhibition of its transcriptional activity and with PGC-1α to induce protein degradation by ubiquitination, resulting in the transcriptional suppression of PEPCK and G6Pase involved in gluconeogenesis. Regulation by CAR of lipid synthesis and oxidation is achieved by its functional cross-talks, respectively, with PPARγ through the degradation of PGC-1α to inhibit expression of the lipogenic genes and with PPARα through either the suppression of CPT-1 expression or the interaction with PGC-1α each to induce tissue-specific inhibition or stimulation of β-oxidation. Whereas CAR stimulates cellular proliferation by suppressing p21 expression through the inhibition of FoxO1 transcriptional activity and inducing cyclin D1 expression, it suppresses apoptosis by inhibiting the activities of MKK7 and JNK-1 through the expression of GADD45B. In conclusion, CAR is involved in the maintenance of homeostasis by regulating not only xenobiotic metabolism but also energy metabolism, cellular proliferation, and apoptosis through diverse cross-talk interactions with extracellular signaling pathways and intracellular regulatory factors.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.245-245
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• 2017

Heavy metal pollution of agricultural soils affects land productivity and has impact on the quality of surrounding ecosystem. Soil microbial community parameters are used as reliable indices for assessing quality of agricultural lands under metal stress. This study investigated bacterial community structure of polluted and undisturbed paddy soils to elucidate soil factors that are related to alteration of bacterial communities under conditions of metal pollution. No obvious differences in the richness or diversity of bacterial communities were observed between samples from polluted and control areas. The bacterial communities of three locations were distinct from one another, and each location possessed distinctive set of bacterial phylotypes. The abundances of several phyla and genera differed significantly between study locations. Variation of bacterial community was mostly related to soil general properties at phylum level while at finer taxonomic levels concentrations of arsenic and lead were significant factors. According to results of bacterial community functional prediction, the soil bacterial communities of metal polluted locations were characterized by more abundant DNA replication and repair, translation, transcription and nucleotide metabolism pathway enzymes while amino acid and lipid metabolism as well as xenobiotic biodegradation potential was reduced.Our results suggest that the soil microbial communities had adapted to the elevated metal concentrations in the polluted soils as evidenced by changes in relative abundances of particular groups of microorganisms at different taxonomic resolution levels, and by altered functional potential of the microbial communities.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.148-156
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• 1994

Chloral hydrate(CH), an intermediate metabolite of trichloroethylene(TRI) is reduced to trichloroethanol(TCE-OH), and is oxidized to trichloroacetic acid(TCA) by the nicotinamide adenine dinucleotide(NAD)-dependent enzymes such as alcohol dehydrogenase(ADH) and aldehyde dehydrogenase(ALDH) in liver. This study was performed to find out the change of activity of ADH and ALDH with increasing amount of TRI. Intraperitoneal injection of TRI were done to the male Sprague Dawely rats(mean body weight, $170{\pm}10g$) in com oil at the dosage of 150, 300, 600 mg/kg for 2 days. The results of experiments are following : 1. The contents of xenobiotic metabolic enzymes in liver are tended to be decreased with increasing amount of, but not significantlly (p>0.05). 2. Activity of ADH in microsome is decreased(p<0.05), and activity of ALDH is increased with amount of TRI(P<0.05). 3. Total trichloro-compounds(TTC) concentration in urine are increased with amount of TRI, but the ratio of between the TCE-OH and the TCA were not shown any critical change. These results suggests that the ALDH in microsome may be related to metabolism of TRI, but ADH was nothing less than the effected to metabolism of TRI.