Tian Wang

Plasma microRNA expression and micronuclei frequency in workers exposed to polycyclic aromatic hydrocarbons.

Background: Ubiquitous polycyclic aromatic hydrocarbons (PAHs) have been shown to alter gene expression patterns and elevate micronuclei (MN) frequency, but the underlying mechanisms are largely unknown. MicroRNAs (miRNAs) are key gene regulators that may be influenced by PAH exposures and mediate their effects on MN frequency. Objectives: We sought to identify PAH-associated miRNAs and evaluate their associations with MN frequency. Methods: We performed a two-stage study in healthy male coke oven workers to identify miRNAs associated with PAH exposures quantified using urinary monohydroxy-PAHs and plasma benzo[a]pyrene-r-7,t-8,c-10-tetrahydrotetrol-albumin (BPDE–Alb) adducts. In the discovery stage, we used Solexa sequencing to test differences in miRNA expression profiles between pooled plasma samples from 20 exposed workers and 20 controls. We then validated associations with eight selected miRNAs in 365 workers. We further evaluated associations between the PAH-associated miRNAs and MN frequency. Results: In the discovery stage, miRNA expression profiles differed between the exposed and control groups, with 68 miRNAs significantly down-regulated [fold change (FC) ≤ –5] and 3 miRNAs mildly up-regulated (+2 ≤ FC < +5) in the exposed group. In the validation analysis, urinary 4-hydroxyphenanthrene and/or plasma BPDE–Alb adducts were associated with lower miR-24-3p, miR-27a-3p, miR-142-5p, and miR-28-5p expression (p < 0.030). Urinary 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyphenanthrene, and the sum of monohydroxy-PAHs were associated with higher miR-150-5p expression (p < 0.030). These miRNAs were associated with higher MN frequency (p < 0.005), with stronger associations in drinkers (pinteraction < 0.015). Conclusions: Associations of PAH exposures with miRNA expression, and of miRNA expression with MN frequency, suggest potential mechanisms of adverse effects of PAHs that are worthy of further investigation. Citation: Deng Q, Huang S, Zhang X, Zhang W, Feng J, Wang T, Hu D, Guan L, Li J, Dai X, Deng H, Zhang X, Wu T. 2014. Plasma microRNA expression and micronuclei frequency in workers exposed to polycyclic aromatic hydrocarbons. Environ Health Perspect 122:719–725; http://dx.doi.org/10.1289/ehp.1307080

Urinary Metals and Heart Rate Variability: A Cross-Sectional Study of Urban Adults in Wuhan, China

Background Epidemiological studies have suggested an association between external estimates of exposure to metals in air particles and altered heart rate variability (HRV). However, studies on the association between internal assessments of metals exposure and HRV are limited. Objectives The purpose of this study was to examine the potential association between urinary metals and HRV among residents of an urban community in Wuhan, China. Methods We performed a cross-sectional analysis of 23 urinary metals and 5-min HRV indices (SDNN, standard deviation of normal-to-normal intervals; r-MSSD, root mean square of successive differences in adjacent normal-to-normal intervals; LF, low frequency; HF, high frequency; TP, total power) using baseline data on 2,004 adult residents of Wuhan. Results After adjusting for other metals, creatinine, and other covariates, natural log-transformed urine titanium concentration was positively associated with all HRV indices (all p < 0.05). Moreover, we estimated negative associations between cadmium and r-MSSD, LF, HF, and TP; between lead and r-MSSD, HF, and TP; and between iron, copper, and arsenic and HF, SDNN, and LF, respectively, based on models adjusted for other metals, creatinine, and covariates (all p < 0.10). Several associations differed according to cardiovascular disease risk factors. For example, negative associations between cadmium and r-MSSD were stronger among participants ≤ 52 years of age (vs. > 52), current smokers (vs. nonsmokers), body mass index < 25 kg/m2 (vs. ≥ 25), and among those who were not hypertensive. Conclusions Urine concentrations of several metals were associated with HRV parameters in our cross-sectional study population. These findings need replication in other studies with adequate sample sizes. Citation Feng W, He X, Chen M, Deng S, Qiu G, Li X, Liu C, Li J, Deng Q, Huang S, Wang T, Dai X, Yang B, Yuan J, He M, Zhang X, Chen W, Kan H, Wu T. 2015. Urinary metals and heart rate variability: a cross-sectional study of urban adults in Wuhan, China. Environ Health Perspect 123:217–222; http://dx.doi.org/10.1289/ehp.1307563

The effects of heavy metals and their interactions with polycyclic aromatic hydrocarbons on the oxidative stress among coke-oven workers

Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are predominate toxic constituents of particulate air pollution that may be related to the increased risk of cardiopulmonary events. We aim to investigate the effects of the toxic heavy metals (arsenic, As; cadmium, Cd; chromium, Cr; nickel, Ni; and lead, Pb), and their interactions with PAHs on oxidative stress among coke-oven workers. A total of 1333 male workers were recruited in this study. We determined their urinary levels of As, Cd, Cr, Ni, Pb, twelve PAH metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α). Multivariate linear regression models were used to analyze the effects of these metals and their interactions with PAHs on 8-OHdG and 8-iso-PGF2α levels. It was found that only urinary As and Ni showed marginal or significant positive linear dose-dependent effects on 8-OHdG in this study population, especially among smokers (β=0.103, P=0.073 and β=0.110, P=0.002, respectively). After stratifying all participants by the quartiles of ΣOH-PAH, all five metals showed linear association with 8-OHdG in the highest quartile subgroup (Q4) of ΣOH-PAHs. However, these five urinary metals showed significantly consistent linear associations with 8-iso-PGF2α in all subjects and each stratum. Urinary ΣOH-PAHs can significant modify the effects of heavy metals on oxidative stress, while co-exposure to both high levels of ΣOH-PAHs and heavy metals render the workers with highest 8-OHdG and 8-iso-PGF2α (all P(interaction)≤0.005). This study showed evidence on the interaction effects of heavy metals and PAHs on increasing the oxidative stress, and these results warrant further investigation in more longitudinal studies.

A genome-wide association study identifies common variants influencing serum uric acid concentrations in a Chinese population

BackgroundUric acid (UA) is a complex phenotype influenced by both genetic and environmental factors as well as their interactions. Current genome-wide association studies (GWASs) have identified a variety of genetic determinants of UA in Europeans; however, such studies in Asians, especially in Chinese populations remain limited.MethodsA two-stage GWAS was performed to identify single nucleotide polymorphisms (SNPs) that were associated with serum uric acid (UA) in a Chinese population of 12,281 participants (GWAS discovery stage included 1452 participants from the Dongfeng-Tongji cohort (DFTJ-cohort) and 1999 participants from the Fangchenggang Area Male Health and Examination Survey (FAMHES). The validation stage included another independent 8830 individuals from the DFTJ-cohort). Affymetrix Genome-Wide Human SNP Array 6.0 chips and Illumina Omni-Express platform were used for genotyping for DFTJ-cohort and FAMHES, respectively. Gene-environment interactions on serum UA levels were further explored in 10,282 participants from the DFTJ-cohort.ResultsBriefly, we identified two previously reported UA loci of SLC2A9 (rs11722228, combined P = 8.98 × 10-31) and ABCG2 (rs2231142, combined P = 3.34 × 10-42). The two independent SNPs rs11722228 and rs2231142 explained 1.03% and 1.09% of the total variation of UA levels, respectively. Heterogeneity was observed across different populations. More importantly, both independent SNPs rs11722228 and rs2231142 were nominally significantly interacted with gender on serum UA levels (P for interaction = 4.0 × 10-2 and 2.0 × 10-2, respectively). The minor allele (T) for rs11722228 in SLC2A9 has greater influence in elevating serum UA levels in females compared to males and the minor allele (T) of rs2231142 in ABCG2 had stronger effects on serum UA levels in males than that in females.ConclusionsTwo genetic loci (SLC2A9 and ABCG2) were confirmed to be associated with serum UA concentration. These findings strongly support the evidence that SLC2A9 and ABCG2 function in UA metabolism across human populations. Furthermore, we observed these associations are modified by gender.

A Solute Carrier Family 22 Member 3 Variant rs3088442 G→A Associated with Coronary Heart Disease Inhibits Lipopolysaccharide-induced Inflammatory Response

Background: Polymorphisms within solute carrier family 22 member 3 (SLC22A3) affects the risk of cardiovascular disease. Results: The polymorphism rs3088442 decreases SLC22A3 mRNA stability and inhibits lipopolysaccharide-induced inflammatory responses. Conclusion: This polymorphism decreased CHD risk by controlling vascular inflammation. Significance: Our findings will elucidate the relationship between SLC22A3 variants, inflammation, and CHD pathogenesis. Recent genome-wide association studies have identified single-nucleotide polymorphism (SNPs) within the SLC22A3 (solute carrier family 22 member 3) gene associated with coronary heart disease (CHD) in the Caucasian population. We performed molecular analysis to investigate the potential role of SLC22A3 variants in CHD. Our study showed that the common polymorphism rs3088442 G→A, which is localized in the 3′ UTR of the SLC22A3 gene, was associated with a decreased risk of CHD in the Chinese population by a case control study. In silico analysis indicated that G→A substitution of SNP rs3088442 created a putative binding site for miR-147 in the SLC22A3 mRNA. By overexpressing miR-147 or inhibiting endogenous miR-147, we demonstrated that SNP rs3088442 G→A recruited miR-147 to inhibit SLC22A3 expression. Moreover, SLC22A3 deficiency significantly decreased LPS-induced monocytic inflammatory response by interrupting NF-κB and MAPK signaling cascades in a histamine-dependent manner. Notably, the expression of SLC22A3A was also suppressed by LPS stimulus. Our findings might indicate a negative feedback mechanism against inflammatory response by which SLC22A3 polymorphisms decreased the risk of CHD.

Associations between 25 Lung Cancer Risk–Related SNPs and Polycyclic Aromatic Hydrocarbon–Induced Genetic Damage in Coke Oven Workers

Background: Genome-wide association studies (GWAS) have identified multiple single-nucleotide polymorphisms (SNP) associated with lung cancer. However, whether these SNPs are associated with genetic damage, a crucial event in cancer initiation and evolution, is still unknown. We aimed to establish associations between these SNPs and genetic damage caused by the ubiquitous carcinogens, polycyclic aromatic hydrocarbons (PAH). Methods: We cross-sectionally investigated the associations between SNPs from published GWAS for lung cancer in Asians and PAH-induced genetic damage in 1,557 coke oven workers in China. Urinary PAH metabolites, plasma benzo[a]pyrene-r-7,t-8,c-10-tetrahydrotetrol-albumin (BPDE-Alb) adducts, urinary 8-hydroxydeoxyguanosine (8-OHdG), and micronuclei (MN) frequency were determined by gas chromatography-mass spectrometry, sandwich ELISA, high-performance liquid chromatography, and cytokinesis-block micronucleus assay, respectively. Results: 13q12.12-rs753955C was suggestively associated with elevated 8-OHdG levels (P = 0.003). Higher 8-OHdG levels were observed in individuals with rare allele homozygotes (CC) than in TT homozygotes (β, 0.297; 95% confidence interval, 0.124–0.471; P = 0.001). 9p21-rs1333040C, 10p14-rs1663689G, and 15q25.1-rs3813572G were significantly associated with lower MN frequency (P values were 0.002, 0.001, and 0.005, respectively). 10p14-rs1663689G polymorphism downregulated the relationship of the total concentration of PAH metabolites to 8-OHdG levels (Pinteraction = 0.002). TERT-rs2736100G and VTI1A-rs7086803A aggravated the relationship of BPDE-Alb adducts to MN frequency, whereas BPTF-rs7216064G attenuated that correlation (all Pinteraction < 0.001). Conclusions: Lung cancer risk–associated SNPs and their correlations with PAH exposure were associated with 8-OHdG levels and MN frequency. Impact: Lung cancer risk–associated SNPs might influence ones susceptibility to genetic damage caused by PAHs. Cancer Epidemiol Biomarkers Prev; 23(6); 986–96. ©2014 AACR.

Association of body mass index with chromosome damage levels and lung cancer risk among males

Epidemiological studies have shown an etiological link between body mass index (BMI) and cancer risk, but evidence supporting these observations is limited. This study aimed to investigate potential associations of BMI with chromosome damage levels and lung cancer risk. First, we recruited 1333 male workers from a coke-oven plant to examine their chromosome damage levels; and then, a cohort study of 12 052 males was used to investigate the association of BMI with lung cancer incidence. We further carried out a meta-analysis for BMI and male lung cancer risk based on cohort studies. We found that men workers with excess body weight (BMI ≥ 25 kg/m2) had lower levels of MN frequencies than men with normal-weight (BMI: 18.5–24.9). Our cohort study indicated that, the relative risk (RR) for men with BMI ≥ 25 to develop lung cancer was 35% lower than RR for normal-weight men. Further meta-analysis showed that, compared to normal-weight men, men with BMI ≥ 25 had decreased risk of lung cancer among both the East-Asians and others populations. These results indicate that men with excess body weight had significant decreased chromosome damage levels and lower risk of lung cancer than those with normal-weight. However, further biological researches were needed to validate these associations.

Polycyclic aromatic hydrocarbons-associated microRNAs and their interactions with the environment: influences on oxidative DNA damage and lipid peroxidation in coke oven workers.

We previously identified five polycyclic aromatic hydrocarbons (PAHs)-associated microRNAs (miRNAs) and found they were associated with chromosome damage. As oxidative damage is the common contributory cause of various PAHs-related diseases, we further investigated the influences of these miRNAs and their interactions with environmental factors on oxidative DNA damage and lipid peroxidation. We measured PAHs internal exposure biomarkers [urinary monohydroxy-PAHs (OH-PAHs) and plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts], the expression levels of PAHs-associated plasma miRNAs (miR-24-3p, miR-27a-3p, miR-142-5p, miR-28-5p, and miR-150-5p), and urinary biomarkers of oxidative DNA damage [8-hydroxydeoxyguanosine (8-OH-dG)] and lipid peroxidation [8-iso-prostaglandin-F2α (8-iso-PGF2α)] in 365 healthy male coke oven workers. These miRNAs were associated with a dose-response increase in 8-OH-dG (β > 0), and with a dose-response decrease in 8-iso-PGF2α (β < 0), especially in workers with lower PAHs exposure levels, in nonsmokers, and in nondrinkers. These miRNAs interacted antagonistically with ΣOH-PAHs and BPDE-Alb adducts (βinteraction < 0) and synergistically with drinking status (βinteraction > 0) to influence 8-OH-dG, while they interacted synergistically with BPDE-Alb adducts (βinteraction > 0) and antagonistically with smoking status (βinteraction < 0) to influence 8-iso-PGF2α. Our results suggested that miRNAs and their interactions with environmental factors might be novel mechanisms mediating the effects of PAHs exposure on oxidative DNA damage and lipid peroxidation.

Genome-wide association study on serum alkaline phosphatase levels in a Chinese population

BackgroundSerum alkaline phosphatase (ALP) is a complex phenotype influenced by both genetic and environmental factors. Recent Genome-Wide Association Studies (GWAS) have identified several loci affecting ALP levels; however, such studies in Chinese populations are limited. We performed a GWAS analyzing the association between 658,288 autosomal SNPs and serum ALP in 1,461 subjects, and replicated the top SNPs in an additional 8,830 healthy Chinese Han individuals. The interactions between significant locus and environmental factors on serum ALP levels were further investigated.ResultsThe association between ABO locus and serum ALP levels was replicated (P = 2.50 × 10-21, 1.12 × 10-56 and 2.82 × 10-27 for SNP rs8176720, rs651007 and rs7025162 on ABO locus, respectively). SNP rs651007 accounted for 2.15% of the total variance of serum ALP levels independently of the other 2 SNPs. When comparing our findings with previously published studies, ethnic differences were observed across populations. A significant interaction between ABO rs651007 and overweight and obesity was observed (FDR for interaction was 0.036); for individuals with GG genotype, those with normal weight and those who were overweight or obese have similar serum ALP concentrations; minor allele A of rs651007 remarkably reduced serum ALP levels, but this effect was attenuated in overweight and obese individuals.ConclusionsOur findings indicate that ABO locus is a major determinant for serum ALP levels in Chinese Han population. Overweight and obesity modifies the effect of ABO locus on serum ALP concentrations.

Imputation-based association analyses identify new lung cancer susceptibility variants in CDK6 and SH3RF1 and their interactions with smoking in Chinese populations

Cell cycle regulation, apoptosis, oxidative stress and inflammation response play critical roles in the development of smoking-induced lung cancer. However, it is still not well known whether their genetic variants are associated with lung cancer susceptibility. In this study, we performed imputation-based association analyses to investigate the influence of common genetic variants in these pathways and their interactions with smoking on lung cancer susceptibility. We first selected 24 042 unvalidated genetic variants in 798 genes from the imputed dataset of the previous lung cancer genome-wide association study in 2331 cases and 3077 controls, and then conducted additional two-stage validations in 4133 cases and 4522 controls. We found a genome-wide significant (P < 5.0 × 10(-8)) association for rs2282987 in CDK6 at 7q21.2 [odds ratio (OR) = 1.18, combined P add = 2.27 × 10(-9)] and a consistent association for rs2706748 in SH3RF1 at 4q32.3 (OR = 1.17, combined P add = 5.10 × 10(-6)). Interaction analyses showed that rs2282987 and rs2706748 interacted with both smoking status (P interaction were 1.04 × 10(-2) and 3.03 × 10(-2), respectively) and smoking history (P interaction were 1.21 × 10(-2) and 5.21 × 10(-2), respectively) to contribute to lung cancer susceptibility in subjects aged 51-60 years. These results further underscore the contribution of genetic variants involved in pathways of cell cycle regulation and apoptosis to lung cancer susceptibility, and highlight gene-environment interactions in lung cancer etiology, especially in subjects aged 51-60 years.