The aromatic-ring-hydroxylating dioxygenase is a key enzyme that initiates the biodegradation of polycyclic aromatic hydrocarbons in bacteria. In the present study, a novel dioxygenase sequence was cloned from Terrabacter sp. FLO using a genome walking method. The dioxygenase was cloned into pET17 and actively expressed in E.coli BL21 (DE3) in co-expression with electron transfer chain proteins. The recombinant dioxygenase was found to transform phenanthrene, fluorene, pyrene and fluoranthene into the cis-dihydrodiol metabolites.
Actinomycetales ; enzymology ; genetics ; Bacterial Proteins ; genetics ; metabolism ; Biodegradation, Environmental ; Cloning, Molecular ; Dioxygenases ; genetics ; metabolism ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; metabolism ; Fluorenes ; metabolism ; Hydroxylation ; Molecular Sequence Data ; Phenanthrenes ; metabolism ; Polycyclic Aromatic Hydrocarbons ; metabolism ; Pyrenes ; metabolism ; Recombinant Proteins ; metabolism

OBJECTIVETo investigate DNA and chromosome damage in peripheral blood lymphocyte of coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs).

METHODSOne hundred and thirty-seven coke oven workers and 50 controls without occupational PAHs exposure were investigated. Comet assay and cytokinesis-block micronucleus (CBMN) detection were used to evaluate DNA and chromosomal damage levels in peripheral blood lymphocyte. Urinary 1-hydroxypyrene level was used to assess the personal internal PAHs exposure dose. Personal information including occupational history, age, sex, smoking and drinking status was collected by questionnaire.

RESULTSUrinary 1-hydroxypyrene level in coke oven workers [(5.76 +/- 1.04) micro mol/mol Cr] was significantly higher than that in controls [(0.70 +/- 0.32) micro mol/mol Cr]. The rate of CBMN and comet tail moment of lymphocyte in coke oven workers [8.0 per thousand (0.0 per thousand - 30.0 per thousand ) and 2.09 (0.31 - 75.41), respectively] were higher than those in controls [3.5 per thousand (0.0 per thousand - 13.0 per thousand ) and 1.05 (0.11 - 6.63), P < 0.05]. In controls, the comet moment in smokers was significantly higher than that in non-smokers [1.44 (0.23 - 6.63) vs 0.81 (0.11 - 3.47), P < 0.05]. According to the length of work, 137 coke oven workers were classified into 3 groups i.e. 0.5 yrs , 16.0 yrs and 22.0 yrs group, and the comet moments were 1.34 (0.31 - 37.84), 2.32 (0.49 - 52.97) and 3.20 (0.45 - 75.41) respectively after adjusting the age, sex, smoking, drinking and level of urinary 1-hydroxy-pyrene. There was a rising tendency along with the increase in length of work.

CONCLUSIONUnder present PAHs exposure levels, both comet assay and Cytokinesis-block micronucleus test could detect PAHs-induced genotoxicity in coke oven workers, and comet assay is more suitable to assess the cumulative damage effect on DNA.

Adult ; Coke ; Comet Assay ; DNA Damage ; Female ; Humans ; Lymphocytes ; metabolism ; Male ; Middle Aged ; Occupational Exposure ; analysis ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Pyrenes ; analysis ; Time Factors

OBJECTIVETo study whether the argyrophil nucleolar organizer regions (AgNOR) in T lymphocytes of peripheral blood in coke-oven workers can be used as a biomarker of effect for polycyclic aromatic hydrocarbon (PAH) exposure.

METHODSFifty-two male coke-oven workers were divided into three groups according to exposure levels of coke oven emissions: high-exposure, middle-exposure and low-exposure workers. Additionally 10 men without occupational PAH exposure were chosen as control group. Peripheral blood T lymphocytes were cultured, spread on slides and stained with silver nitrate. The ratio of AgNOR area vs. nuclear area (I/S) in T lymphocytes was analyzed. Urinary 1-hydroxypyrene (1-OHP) was measured as the internal dose of PAH exposure.

RESULTSMean urinary 1-OHP level in high-exposure group (16.56 +/- 2.77 micromol/mol Cr) was significantly higher than those in low-exposure group (3.30 +/- 2.77 micromol/mol Cr, P < 0.001) and control group (3.04 +/- 1.58 micromol/mol Cr, P < 0.01). The mean I/S of AgNOR in T lymphocytes in high-exposure group (0.056 +/- 0.010) was significantly lower than those in middle-exposure group (0.065 +/- 0.013, P < 0.05), low-exposure group (0.067 +/- 0.008, P < 0.01) and control group (0.076 +/- 0.007, P < 0.001). It was also found that I/S of AgNOR were significantly decreased in middle-exposure group and low-exposure group in comparison with control group (P < 0.01, P < 0.05).

CONCLUSIONSThe occupational exposure to PAH resulted in increase of 1-OHP in urine and decrease of AgNOR in T lymphocytes. PAH exposure might lead to damage T lymphocytes function and AgNOR may be considered as a biomarker of effect for PAH exposure.

Antigens, Nuclear ; blood ; Biomarkers ; blood ; urine ; Coke ; poisoning ; Humans ; Lymphocytes ; cytology ; drug effects ; metabolism ; Male ; Occupational Exposure ; analysis ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Pyrenes ; analysis

OBJECTIVETo investigate the relationship between the urinary 1-hydroxypyrene level and cytokinesis-block micronucleus and the olive moment of comet assay in peripheral blood lymphocyte in coke oven workers.

METHODSOne hundred and thirty-three workers from a coke plant and 28 referents without occupational PAH exposure were recruited in this study. Urinary level of 1-hydroxypyrene was measured by alkaline hydrolysis combined with high performance liquid chromatography as an internal exposure dose, and the DNA and chromosomal damage of peripheral blood lymphocyte were evaluated with comet assay and cytokinesis-block micronucleus method. Personal information including occupational history, age, sex, smoking and alcohol drinking, was collected by questionnaire.

RESULTSThere existed a good correlationship between the urinary level of 1-hydroxypyrene and frequency of micronuclei per 1 000 binucleated cells or the olive moment of comet assay in the study subjects, after adjusting for sex, age, smoking and alcohol drinking (r > 0.25, P < 0.01). One hundred and sixty-one subjects were divided into three groups by their urine 1-hydroxypyrene level (expressed as 0.30 - 2.44, 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr), and the geometric means of their urinary levels of 1-hydroxypyrene were 1.14, 4.32 and 12.49 micro mol/mol Cr, respectively. After adjusting for age, sex, smoking and alcohol drinking by multiple nonparametric analysis of covariance, the median of olive moment of comet assay in the group of 7.10 - 33.10 micro mol/mol Cr was 3.67, significantly higher than that in the groups of 0.30 - 2.44 and 2.45 - 7.09; and the micronuclei frequencies in the groups of 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr were 8.00 per thousand and 7.50 per thousand, respectively, significantly higher than that in the group of 0.30 - 2.44 micro mol/mol Cr (6.00 per thousand ).

CONCLUSIONSThe comet assay of peripheral blood lymphocyte was more suitable to detect the PAHs-induced early genotoxicity, than the cytokinesis-block micronucleus.

Adult ; Coke ; adverse effects ; Comet Assay ; Female ; Humans ; Male ; Micronuclei, Chromosome-Defective ; drug effects ; Micronucleus Tests ; Occupational Exposure ; adverse effects ; Pyrenes ; metabolism

Epidemiologic studies have suggested the association between environmental exposure to volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) and the increased risk of incurring asthma. Yet there is little data regarding the relationship between personal exposure to air pollution and the incidence of asthma in children. This study was designed to evaluate the effect of exposure to air pollution on children with asthma by using exposure biomarkers. We assessed the exposure level to VOCs by measuring urinary concentrations of hippuric acid and muconic acid, and PAHs by 1-OH pyrene and 2-naphthol in 30 children with asthma and 30 children without asthma (control). The mean level of hippuric acid was 0.158+/-0.169micromol/mol creatinine in the asthma group and 0.148+/-0.249micromol/mol creatinine in the control group, with no statistical significance noted (p=0.30). The mean concentration of muconic acid was higher in the asthma group than in the control group (7.630+/-8.915micromol/mol creatinine vs. 3.390+/-4.526micromol/mol creatinine p=0.01). The mean level of urinary 1-OHP was higher in the asthma group (0.430+/-0.343micromol/mol creatinine) than the control group (0.239+/-0.175micromol/mol creatinine), which was statistically significant (p=0.03). There was no difference in the mean concentration of 2-NAP between the two groups (9.864+/-10.037micromol/mol in the asthma group vs. 9.157+/-9.640micromol/mol in the control group, p=0.96). In conclusion, this study suggests that VOCs and PAHs have some role in asthma.
Air Pollutants/*pharmacology ; Asthma/*physiopathology/urine ; Case-Control Studies ; Child, Preschool ; Creatinine/urine ; Female ; Hippurates/urine ; Humans ; Male ; Naphthols/urine ; Organic Chemicals/chemistry/*pharmacology ; Polycyclic Hydrocarbons, Aromatic/*pharmacology ; Pyrenes/metabolism ; Sorbic Acid/*analogs & derivatives/metabolism ; Volatilization

OBJECTIVETo investigate the relationship between lymphocyte DNA damage and polycyclic aromatic hydrocarbons (PAHs) exposure in coke oven workers.

METHODSTwo hundred and thirty-five coke oven workers and 30 controls were selected in this study. Alkaline single-cell gel electrophoresis was used to evaluate the lymphocyte DNA damage, HPLC was employed to measure 1-hydroxypyrene levels in spot urine samples which were obtained at the end of a workweek (4 days of 8 hours/day) and personal information including occupational exposure, age, sex, smoking and drinking status was collected by the questionnaire.

RESULTSThe lymphocyte DNA damage level expressed as olive moment in coke oven workers was significantly higher than that of controls [2.47 (0.22 approximately 46.68) vs 0.94 (0.42 approximately 4.21), P < 0.01], and correlation between urinary 1-hydroxypyrene concentrations and olive moment was found (Spearman Partial correlation coefficient = 0.22, P < 0.01) in coke oven workers. The 1.9 of olive moment value was used as the limit to determine whether the subject DNA damage was positive. The coke oven workers had significantly higher risk in DNA damage (adjusted OR = 5.38, 95% CI = 2.07 approximately 14.08) than did controls, and dose-response relationships were also found between external exposure (exposure category) or internal doses (urinary 1-hydroxypyrene) and DNA damage.

CONCLUSIONThere are dose-effect and dose-response relationships between PAHs exposure and lymphocyte DNA damage in coke oven workers.

Adult ; Animals ; Coke ; adverse effects ; DNA Damage ; drug effects ; Dose-Response Relationship, Drug ; Female ; Humans ; Lymphocytes ; metabolism ; Male ; Occupational Exposure ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Pyrenes ; analysis ; metabolism ; Surveys and Questionnaires

OBJECTIVETo investigate the associations of polymorphisms of metabolic enzyme genes with urinary 1-hydroxypyrene levels in coke oven workers.

METHODSOne hundred and forty-eight workers from a coke oven plant and 69 controls without occupational PAHs exposure were selected in this study. Urinary 1-hydroxypyrene was detected by high performance liquid chromatography with florescence detector. The genotypes at I462V site in exon 7 of CYP1A1 gene, GSTM1, GSTT1, I105V site in GSTP1gene, Pst1 and Dra1 sites in CYP2E1 gene, P187S site in NQO1 gene, Kpn1, BamH1 and Taq1 sites in NAT2 gene, and H113Y, R139H sites in mEH gene were determined by PCR-based methods. Personal information including occupational exposure history, age, sex, smoking and drinking status was collected by the questionnaire.

RESULTSThe level of urinary 1-hydroxypyrene in coke oven workers [(5.61 +/- 1.04) mol/mol Cr] was higher than that in control [(0.74 +/- 0.32) micro mol/mol Cr]. After adjusting external occupational exposure category and smoking, coke oven workers with variant homozygotes at H113Y site of mEH gene had significantly higher urinary 1-hydroxypyrene concentrations than those with heterozygotes, and wild homozygotes (6.41 +/- 1.09 vs. 6.24 +/- 1.08, and 4.62 +/- 0.95 micro mol/mol Cr, P < 0.05), and gene-gene interaction was found between CYP1A1 and mEH.

CONCLUSIONGenetic polymorphism of mEH gene could be a susceptible biomarker in coke oven workers which was involved in the individual susceptibility on metabolism of PAHs.

Coke ; adverse effects ; Cytochrome P-450 CYP1A1 ; genetics ; DNA Damage ; genetics ; Epoxide Hydrolases ; genetics ; Genetic Predisposition to Disease ; genetics ; Glutathione Transferase ; genetics ; Humans ; Male ; Occupational Exposure ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Polymorphism, Genetic ; Pyrenes ; analysis ; metabolism

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants present in air and food. Among PAHs, benzo(a)pyrene(BaP), phenanthrene (PH) and pyrene (PY) are considered to be important for their toxicity or abundance. To investigate the changes of biomarkers after PAH exposure, rats were treated with BaP (150 microgram/kg) alone or with PH (4,300 microgram/kg) and PY (2,700 microgram/kg) (BPP group) by oral gavage once per day for 30 days. 7-ethoxyresorufin-O-deethylase activity in liver microsomal fraction was increased in only BaP groups. The highest concentration (34.5 ng/g) of BaP, was found in muscle of rats treated with BaP alone at 20 days of treatment; it was 23.6 ng/g in BPP treated rats at 30 days of treatment. The highest PH concentration was 47.1 ng/g in muscle and 118.8 ng/g in fat, and for PY it was 29.7 ng/g in muscle and 219.9 ng/g in fat, in BPP groups. In urine, 114-161 ng/ml 3-OH-PH was found, while PH was 41-69 ng/ml during treatment. 201-263 ng/ml 1-OH-PY was found, while PH was 9-17 ng/ml in urine. The level of PY, PH and their metabolites in urine was rapidly decreased after withdrawal of treatment. This study suggest that 1-OH-PY in urine is a sensitive biomarker for PAHs; it was the most highly detected marker among the three PAHs and their metabolites evaluated during the exposure period and for 14 days after withdrawal.
Adipose Tissue/chemistry/drug effects ; Animals ; Benzo(a)pyrene/analysis/metabolism/*toxicity ; Biological Markers/metabolism/urine ; Blood Chemical Analysis ; Body Weight/drug effects ; Cytochrome P-450 CYP1A1/metabolism ; Environmental Pollutants/blood/metabolism/*toxicity/urine ; Female ; Liver/drug effects/enzymology ; Lymphocytes/drug effects/metabolism ; Muscle, Skeletal/drug effects/metabolism ; Organ Size/drug effects ; Phenanthrenes/blood/metabolism/*toxicity/urine ; Pyrenes/analysis/metabolism/*toxicity ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVETo investigate the association of XRCC1 polymorphisms and chromosomal damage levels in peripheral blood lymphocyte in coke-oven workers.

METHODSThe study included 141 coke-oven workers who exposed to a high level of polycyclic aromahaplotpetic hydrocarbon and 66 non-exposed controls. Urinary 1-hydroxypyrene and chromosome damage in peripheral lymphocyte were measured. Four -tagging single nucleotide polymorphisms in XRCC1 gene, including C26304T, G27466A, G28152A and G36189A, were detected and the XRCC1 haplotypes were estimated by using an extension of Clark algorithm. The associations between haplotype pairs and micronuclei data were assessed by analysis of covariance in the exposed and non-exposed groups.

RESULTSThe geometric means of urinary 1-hydroxypyrene levels in coke-oven workers and the controls were 12.0 and 0.7 micromol/mol Cr respectively (P < 0.01). The cytokinesis-block micronucleus cytokinesis-block micronucleus frequencies (number of micronucleus per 1 000 binucleated lymphocytes) was significantly higher in coke-oven workers (0.95 +/- 0.66)% than in the controls (0.40 +/- 0.36)%, P < 0.01. The haplotype CGGG was associated with the decreased frequencies of total micronucleus, and the haplotypes TGGG (P = 0.01) and CGAG (P < 0.05) were associated with the increased frequencies of total micronucleus in the multivariate analysis with adjustment for covariates among coke-oven workers.

CONCLUSIONSThe genetic polymorphisms of XRCC1 gene could influence the chromosome damage levels in coke-oven workers.

Adult ; China ; Chromosome Breakage ; Coke ; poisoning ; DNA-Binding Proteins ; genetics ; Female ; Genetic Predisposition to Disease ; Haplotypes ; Humans ; Lymphocytes ; metabolism ; Male ; Micronucleus Tests ; methods ; Middle Aged ; Occupational Diseases ; etiology ; genetics ; urine ; Occupational Exposure ; adverse effects ; analysis ; Polymorphism, Single Nucleotide ; Pyrenes ; analysis ; X-ray Repair Cross Complementing Protein 1

OBJECTIVETo investigate the association between polymorphisms of metabolic enzyme genes and chromosomal damage risk in peripheral blood lymphocytes among coke oven workers.

METHODSOne hundred and fourty-nine coke oven workers and 24 referents without occupational polycyclic aromatic hydrocarbons (PAH) exposure were recruited in this study. Urinary 1-hydroxypyrene levels were measured as the internal dose of PAH exposure. The 6 per 1 000 of micronucleus value was used as the cut-off value to determine whether the individual's chromosomal damage was positive. The genotypes of CYP1A1, GSTM1, GSTT1, GSTP1, CYP2E1, NQO1, NAT2 and mEH genes were determined by PCR-based methods. Multiple logistic regression was used to calculate the adjusted ORs and the 95% CI for the risk of chromosomal damage and to analyze the gene-gene interaction.

RESULTSIn 173 subjects, after adjusting the occupational exposure, age, sex, smoking and drinking status, the subjects with GSTM1 null genotype have significantly higher risk for chromosomal damage than subjects with GSTM1 positive genotype (adjusted OR = 2.01, 95% CI = 1.03 -3.91). Compared with the wild homozygotes at P187S site of NQO1 gene, the variant homozygotes have significantly higher risk for chromosomal damage (adjusted OR = 3.18, 95% CI = 1.18 - 8.62). The subjects with variant allele at H113Y site of mEH gene have significantly lower risk for chromosomal damage (adjusted OR = 0.40, 95% CI = 0.19 - 0.88). No significant associations were found for other gene polymorphisms and chromosomal damage risk. In addition, the gene-gene interactions were also found among GSTM1, NQO1 gene P187S and mEH gene H113Y polymorphisms for the risk of chromosomal damage risk.

CONCLUSIONSignificant associations between genetic polymorphisms in GSTM1, NQO1 and mEH gene and risk for chromosomal damage were found among occupational PAH-exposed workers, which related to the mechanism of PAH carcinogenesis.

Adult ; DNA Damage ; genetics ; Epoxide Hydrolases ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Glutathione Transferase ; genetics ; Humans ; Logistic Models ; Lymphocytes ; metabolism ; Male ; Middle Aged ; Multivariate Analysis ; NAD(P)H Dehydrogenase (Quinone) ; genetics ; Occupational Exposure ; Polycyclic Aromatic Hydrocarbons ; poisoning ; Polymorphism, Genetic ; Pyrenes ; analysis ; Risk Factors