DNA methylation changes in Mexican children exposed to arsenic from two historic mining areas in San Luis potosí

Arsenic is a carcinogen and epimutagen that threatens the health of exposed populations worldwide. In this study, we examined the methylation status of Alu and long interspersed nucleotide elements (LINE‐1) and their association with levels of urinary arsenic in 84 Mexican children between 6 and 12 years old from two historic mining areas in the State of San Luis Potosí, Mexico. Urinary arsenic levels were determined by atomic absorption spectrophotometry and DNA methylation analysis was performed in peripheral blood leukocytes by bisulfite‐pyrosequencing. The geometric mean of urinary arsenic was 26.44 µg/g Cr (range 1.93–139.35). No significant differences in urinary arsenic or methylation patterns due to gender were observed. A positive correlation was found between urinary arsenic and the mean percentage of methylated cytosines in Alu sequences (Spearman correlation coefficient r = 0.532, P < 0.001), and a trend of LINE‐1 hypomethylation was also observed (Spearman correlation coefficient r = ?0.232, P = 0.038) after adjustment for sex and age. A linear regression model showed an association with log‐normalized urinary arsenic for Alu (β = 1.05, 95% CI: 0.67; 1.43, P < 0.001) and LINE‐1 (β = ?0.703, 95% CI: ?1.36; ?0.38, P = 0.038). Despite the low‐level arsenic exposure, a subtle epigenetic imbalance measured as DNA methylation was detected in the leukocytes of Mexican children living in two historic mining areas. Environ. Mol. Mutagen. 57:717–723, 2016. © 2016 Wiley Periodicals, Inc.     

Bleomycin‐induced chromosomal damage and shortening of telomeres in peripheral blood lymphocytes of incident cancer patients

Disruption of genomic integrity due to deficient DNA repair capacity and telomere shortening constitute hallmarks of malignant diseases. Incomplete or deficient repair of DNA double‐strand breaks (DSB) is manifested by chromosomal aberrations and their frequency reflects inter‐individual differences of response to exposure to mutagenic compounds. In this study, we investigated chromosomal integrity in peripheral blood lymphocytes (PBL) from newly diagnosed cancer patients, including 47 breast (BC) and 44 colorectal cancer (CRC) patients and 90 matched healthy controls. Mutagen sensitivity was evaluated by measuring chromatid breaks (CTAs) induced by bleomycin and supplemented by the chemiluminescent measurement of γ‐H2AX phosphorylation in 19 cancer patients (11 BC, 8 CRC). Relative telomere length (RTL) was determined in 22 BC, 32 CRC, and 64 controls. We observed statistically significant increased level of CTAs (P = .03) and increased percentage of aberrant cells (ACs) with CTAs (P = .05) in CRC patients compared with controls after bleomycin treatment. No differences were observed between BC cases and corresponding controls. CRC and BC patients with shorter RTL (below median) exhibited significantly higher amount of ACs (P = .02), CTAs (P = .02), and cells with high frequency of CTAs (≥12 CTAs/PBL; P = .03) after bleomycin treatment. No such associations were observed in healthy controls. γ‐H2AX phosphorylation after bleomycin treatment in PBL did not differ between CRC and BC patients. Our results suggest that altered DSB repair measured by sensitivity towards mutagen in PBL occurs particularly in CRC carcinogenesis. Irrespective of cancer type, telomere shortening may be associated with a decreased capacity to repair DSB.     

Alterations of telomere length and DNA methylation in hairdressers: A cross‐sectional study

Working as hairdressers has been associated with increased risk for cancer, particularly bladder cancer. To evaluate if current hairdressers have elevated risks of adverse health effects, we measured several biomarkers related to cancer‐related DNA alterations. We enrolled 295 hairdressers and 92 non‐hairdressers (all female non‐smokers) from Stockholm and southern Sweden. Questionnaire data were collected for each participant, including work tasks for the hairdressers. We measured telomere length in peripheral blood leucocytes using quantitative PCR and DNA methylation status of genes relevant for bladder cancer using methylation sensitive high resolution melting analysis. The hairdressers had shorter telomeres (β = −0.069, P = 0.019) compared with non‐hairdressers. Shorter telomeres were found in hairdressers up to 32 years old performing hair waving more than once per week as compared with hairdressers in the same age group performing hair waving less often (β = −0.12, P = 0.037). Hair waving was associated with less frequent CDKN2A methylation (odds ratio, OR = 0.19, P = 0.033). Shorter telomeres in hairdressers may indicate a genotoxic effect. Performing hair waving was associated with short telomere length, although the effect was only observed in young hairdressers. No clear patterns were discerned with regard to DNA methylation of bladder cancer‐related genes. The observed changes of methylation were not all in the expected direction and warrant further investigation. Environ. Mol. Mutagen. 57:159–167, 2016. © 2015 Wiley Periodicals, Inc.     

Prenatal phthalate exposure,infant growth,and global DNA methylation of human placenta

Prenatal phthalate exposure has been shown to be associated with reduced fetal growth. Epigenetic changes such as DNA methylation might be a molecular mechanism through which phthalate exposure affects fetal growth. In this study, we examined associations between prenatal phthalate exposure, infant growth, and global DNA methylation in human placenta samples. We measured global DNA methylation of 119 subjects [55 fetal growth restriction (FGR) cases and 64 normal controls], as assessed by long interspersed nuclear element‐1 (LINE‐1) methylation, via quantitative polymerase chain reaction‐pyrosequencing. Prenatal phthalate exposure was assessed by measuring maternal urinary phthalate metabolites concentrations using high‐performance liquid chromatography‐tandem mass spectrometry. Concentrations of mono (2‐ethyl‐5‐hydroxyhexyl) phthalate (MEHHP), mono (2‐ethyl‐5‐oxohexyl) phthalate (MEOHP), and SumDEHP (molar sum of MEHP, MEHHP, and MEOHP) were significantly higher in FGR cases than those in normal controls (P = 0.002, 0.003, and 0.002, respectively). Placental LINE‐1 methylation were found to be positively associated with fetal birth weight standard deviation scores, and negatively associated with urinary phthalate metabolites concentrations (MEHHP and SumDEHP). Every natural‐log unit increase in urinary concentrations of MEHHP and SumDEHP was associated with 0.015 (β = ?0.015, P = 0.150) and 0.012 kg (β = ?0.012, P = 0.167) decrease in birth weight mediated through LINE‐1 methylation. These findings suggest that changes in placental LINE‐1 methylation might be part of the underlying biological pathway between prenatal phthalate exposure and adverse fetal growth. Environ. Mol. Mutagen. 56:286–292, 2015. © 2014 Wiley Periodicals, Inc.     

Do mutations in DNMT3A/3B affect global DNA hypomethylation among benzene‐exposed workers in Southeast China?: Effects of mutations in DNMT3A/3B on global DNA hypomethylation

Global DNA hypomethylation is commonly observed in benzene‐exposed workers, but the underlying mechanisms remain unclear. We sought to discover the relationships among reduced white blood cell (WBC) counts, micronuclear (MN) frequency, and global DNA methylation to determine whether there were associations with mutations in DNMT3A/3B. Therefore, we recruited 410 shoe factory workers and 102 controls from Wenzhou in Zhenjiang Province. A Methylated DNA Quantification Kit was used to quantify global DNA methylation, and single nucleotide polymorphisms (SNPs) in DNMT3A (rs36012910, rs1550117, and R882) and DNMT3B (rs1569686, rs2424909, and rs2424913) were identified using the restriction fragment length polymorphism method. A multilinear regression analysis demonstrated that the benzene‐exposed workers experienced significant global DNA hypomethylation compared with the controls (β = −0.51, 95% CI: −0.69 to −0.32, P < 0.001). The DNMT3A R882 mutant allele (R882H and R882C) (β = −0.25, 95% CI: −0.54 to 0.04, P = 0.094) and the DNMT3B rs2424909 GG allele (β = −0.37, 95% CI: −0.70 to −0.03, P = 0.031) were significantly associated with global DNA hypomethylation compared with the wild‐type genotype after adjusting for confounding factors. Furthermore, the MN frequency in the R882 mutant allele (R882H and R882C) (FR = 1.18, 95% CI: 0.99 to 1.40, P = 0.054) was higher than that of the wild‐type. The results imply that hypomethylation occurs due to benzene exposure and that mutations in DNMTs are significantly associated with global DNA methylation, which might have influenced the induction of MN following exposure to benzene. Environ. Mol. Mutagen. 58:678–687, 2017. © 2017 Wiley Periodicals, Inc.     

Oxidative stress,telomere shortening,and DNA methylation in relation to low‐to‐moderate occupational exposure to welding fumes

Evidence suggests that exposure to welding fumes is a risk factor for lung cancer. We examined relationships between low‐to‐moderate occupational exposure to particles from welding fumes and cancer‐related biomarkers for oxidative stress, changes in telomere length, and alterations in DNA methylation. We enrolled 101 welders and 127 controls (all currently nonsmoking men) from southern Sweden. We performed personal sampling of respirable dust and measured 8‐oxodG concentrations in urine using a simplified liquid chromatography tandem mass spectrometry method. Telomere length in peripheral blood was measured by quantitative polymerase chain reaction. Methylation status of 10 tumor suppressor genes was determined by methylation‐sensitive high‐resolution melting analysis. All analyses were adjusted for age, body mass index, previous smoking, passive smoking, current residence, and wood burning stove/boiler at home. Welders were exposed to respirable dust at 1.2 mg/m³ (standard deviation, 3.3 mg/m³; range, 0.1–19.3), whereas control exposures did not exceed 0.1 mg/m³ (P < 0.001). Welders and controls did not differ in 8‐oxodG levels (β = 1.2, P = 0.17) or relative telomere length (β = ?0.053, P = 0.083) in adjusted models. Welders showed higher probability of adenomatous polyposis coli (APC) methylation in the unadjusted model (odds ratio = 14, P = 0.014), but this was not significant in the fully adjusted model (P = 0.052). Every working year as a welder was associated with 0.0066 units shorter telomeres (95% confidence interval ?0.013 to ?0.00053, P = 0.033). Although there were no clear associations between concentrations of respirable dust and the biomarkers, there were modest signs of associations between oxidative stress, telomere alterations, DNA methylation, and occupational exposure to low‐to‐moderate levels of particles. Environ. Mol. Mutagen. 56:684–693, 2015. © 2015 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.     

Types of chromosomal aberrations induced by seed aging in crepis capillaris

The types of chromosomal aberrations during the aging of Crepis capillaris (Hawksbeard; fam. Asteraceae) seeds were investigated. Seeds were stored at 22°C for 2, 4, 6, and 8 years. Chromosomal aberrations were analyzed in metaphase chromosomes at the first and second mitotic cycles. A colchicine block was used for the differentiation of individual mitotic cycles. The frequency of chromosomal aberrations induced during seed aging gradually increased with the increase in the time of aging, reaching its maximal value after 8 years of aging. Both chromatid and chromosome types of aberrations were observed in first mitosis. At all times of aging, the frequency of chromosome-type aberrations considerably surpassed the frequency of the chromatid type. At the different times of aging, the frequency of chromosome-type aberrations was 3–4.5 times higher than that of chromatid-type aberrations. In the second mitosis, the frequency of both aberration types was low. The frequency and type of derived chromosomal aberrations observed in second mitosis corresponded to those observed in first mitosis. These results are discussed in relation to the factors inducing chromosome lesions during seed aging and the mechanism of formation of chromosomal aberrations. © 1994 Wiley-Liss, Inc.     

Factors associated with experiences of genetic discrimination among individuals at risk for huntington disease

The purpose of this study was to identify factors that are associated with experiencing genetic discrimination (GD) among individuals at risk for Huntington disease (HD). Multivariable logistic regression analysis was used to examine factors associated with experiencing GD in data from a cross‐sectional, self‐report survey of 293 individuals at risk for HD. The study sample comprised 167 genetically tested respondents, and 66 who were not tested (80% response rate). Overall, individuals who learn they are at risk for HD at a younger age (OR = 3.1; 95% CI: 1.5–6.2; P = 0.002), are mutation‐positive (OR = 2.8; 95% CI: 1.4–6.0; P = 0.006), or are highly educated (OR = 2.7; 95% CI: 1.4–5.1; P = 0.002) are more likely to experience GD, particularly in insurance, family, and social settings. Further, younger age was associated with discrimination in insurance (OR = 0.97; 95% CI: 0.94–1.00; P = 0.038). This study provides evidence that some people who are at risk for HD were more likely to experience GD than others. Individuals who learned they are at risk for HD at a younger age and those who are mutation‐positive were more likely to experience GD, particularly in insurance, family, and social settings. Younger individuals were more likely to experience discrimination in the insurance setting. Overall, highly educated individuals were also more likely to report discrimination. These results provide direction for clinical and family discussions, counseling practice, and policy aimed at mitigating experiences of GD. © 2010 Wiley‐Liss, Inc.     

Two Rare Variants Explain Association with Acute Myocardial Infarction in an Extended Genomic Region Including the Apolipoprotein(A) Gene

Relatively low numbers of kringle 4 type 2 repeats in apolipoprotein(a) and specific haplotypes of the SLC22A3‐LPAL2‐LPA region on chromosome 6 are associated with an increased risk of coronary disease. We examined the possibility that rs3798220 and rs10455872, short variations located in LPA [the apolipoprotein(a) gene], and related to the number of kringle 4 type 2 repeats, may serve as markers for the association between haplotypes and acute myocardial infarction. Genotypes were determined with TaqMan assays in a sample of 2136 cases and 1211 controls. The minor alleles of rs3798220 and rs10455872 were associated with increased risks (rs3798220‐C: adjusted OR 2.14, 95% CI, 1.37–3.33, P = 0.00080; rs10455872‐G: adjusted OR 1.74, 95% CI 1.36–2.24, P < 0.00001). After adjustments were made for potential confounders, none of nine polymorphisms included in a haplotype analysis were singly related to disease. Two risk haplotypes were identified; one (CCTTGTGTG; OR 1.25, 95% CI 1.08–1.45, P = 0.0022) was correlated with rs3798220‐C and the other (CCCTGGATC; OR 1.65, 95% CI 1.14–2.38, P = 0.0074) with rs10455872‐G. Thus, the findings allowed for a more precise definition of risk‐associated markers: specific nucleotides in LPA instead of standard haplotypes defined by noneffective variants from the extensive SLC22A3‐LPAL2‐LPA region.     

TERT Polymorphism rs2853669 Influences on Lung Cancer Risk in the Korean Population

Short telomeres are known as one of the risk factors for human cancers. The present study was conducted to evaluate the association between 6 polymorphisms, which were related with short telomere length in the Korean population, and lung cancer risk using 1,100 cases and 1,096 controls. Among the 6 polymorphisms, TERT rs2853669 was significantly associated with increased lung cancer risk under a recessive model (odds ratio [OR]=1.38, 95% confidence interval [CI]=1.05-1.81, P=0.02). The effect of rs2853669 on lung cancer risk was significant in younger individuals (OR=1.73, 95% CI=1.18-2.54, P=0.005) and adenocarcinoma (OR=1.50, 95% CI=1.07-2.07, P=0.02). Our results suggest that a common functional promoter polymorphism, TERT rs2853669, may influence both telomere length and lung cancer risk in the Korean population.

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Histone methyltransferase Suv39h1 deficiency prevents Myc‐induced chromosomal instability in murine myeloid leukemias

Suv39h1 mediates heterochromatin formation in pericentric and telomeric regions by trimethylation of lysine 9 of histone 3 (H3K9me3). Yet, its role in the induction of chromosomal instability is poorly understood. We established a leukemia model by retrovirally expressing Myc in wild‐type and histone methyltransferase Suv39h1‐deficient hematopoietic cells and characterized the resulting leukemias for chromosomal instability. All mice that received cells overexpressing Myc developed myeloid leukemia with a median survival of 44 days posttransplantation. Myc‐overexpressing wild‐type leukemias demonstrated clones with numerical chromosomal aberrations (5/16). In secondary transplantations of these leukemic cells, structural changes, mostly end‐to‐end fusions of chromosomes, appeared (10/12). In contrast, leukemic cells overexpressing Myc with reduced or no Suv39h1 expression had a normal karyotype in primary, secondary, and tertiary transplantations (16/16). Myc‐transduced Suv39h1‐deficient cells showed less critically short telomeres (P < 0.05) compared with Myc‐transduced wild‐type bone marrow cells. Gene expression analysis showed upregulation of genes involved in the alternative lengthening of telomeres (ALT) mechanism. Thus, we hypothesize that loss of Suv39h1 implies activation of the ALT mechanism, in turn ensuring telomere length and stability. Our data show for the first time that Suv39h1 deficiency may prevent chromosomal instability by more efficient telomere stabilization in hematopoietic bone marrow cells overexpressing Myc. © 2013 Wiley Periodicals, Inc.     

Association between the Interleukin‐6 Gene −572 C/G Polymorphism and the Risk of Type 2 Diabetes Mellitus: A Meta‐Analysis of 11,681 Subjects

The association between the interleukin‐6 (IL‐6) gene ?572 C/G (rs1800796) polymorphism and type 2 diabetes mellitus (T2DM) risk remains controversial. Thus, we performed this meta‐analysis by searching PubMed, Embase, Web of Science, CBMdisc and CNKI databases until January 30, 2012. In addition, hand searching of the references of identified articles was performed. A total of 10 case–control studies including 11,681 subjects were selected to evaluate the possible association. Our results showed evidence for significant association between the IL‐6 gene ?572 C/G polymorphism and T2DM risk (for G allele vs. C allele: odds ratio [OR] = 1.29, 95% confidence interval [CI] = 1.09–1.52, P = 0.002, P = 0.008 after Bonferroni testing; for G/G vs. C/C: OR = 1.89, 95% CI = 1.51–2.37, P < 0.00001, P < 0.00004 after Bonferroni testing; for GG vs. G/C + C/C: OR = 1.75, 95% CI = 1.20–2.56, P = 0.004, P = 0.016 after Bonferroni testing; for G/G + G/C vs. C/C: OR = 1.32, 95% CI = 1.11–1.57, P = 0.001, P = 0.004 after Bonferroni testing). In addition, similar results were obtained in the subgroup analysis based on ethnicity. In summary, the present meta‐analysis suggests a significant association between the IL‐6 gene ?572 G allele and increased risk of T2DM.     

Influence of the HCV subtype on the virological response to pegylated interferon and ribavirin therapy

The hepatitis C virus genotype is considered to be the most important baseline predictor of a sustained virological response in patients with chronic hepatitis C treated with pegylated interferon and ribavirin. The influence of the subtype on the sustained virological response was investigated in patients infected with genotypes 1, 4, 5, or 6. This study was done on 597 patients with chronic hepatitis C who were given pegylated interferon and ribavirin for 48 weeks. The overall rate of sustained virological response in the 597 patients was 37.8%. Univariate analysis indicated that the sustained virological response of patients infected with subtype 1b (39%) tended to be higher than that of patients infected with subtype 1a (30.6%; P = 0.06) and it was similar to those patients infected with subtypes 4a (51.3%; P = 0.12) or 4d (51.7%; P = 0.16). Multivariate analysis indicated that five factors were independently associated with sustained virological response: the age (OR 0.97; 95% CI = 0.95–0.99), absence of cirrhosis (OR: 2.92; 95% CI = 1.7–5.0; P < 0.01), absence of HIV co‐infection (OR: 2.08; 95% CI = 1.2–3.5; P < 0.01), low baseline plasma HCV RNA concentration (OR: 1.74; 95% CI = 1.2–2.6; P < 0.01), and the subtype 1b (OR: 1.61; 95% CI = 1.0–2.5; P = 0.04) or subtypes 4a and 4d (OR: 2.03; 95% CI = 1.1–3.8; P = 0.03). In conclusion, among difficult‐to‐treat genotypes, the subtype 1a is associated with a lower response to anti‐HCV therapy than subtypes 1b, 4a, and 4d. J. Med. Virol. 81:2029–2035, 2009. © 2009 Wiley‐Liss, Inc.     

CCL2, CCL3 and CCL4 gene polymorphisms in pulmonary tuberculosis patients of South India

Polymorphisms in chemokine genes are important to determine the host–pathogen interactions which influence the chemokine levels. This study was carried out to find whether various CC chemokine gene polymorphisms, located in the promoter, exon‐2 and intron‐1 regions are associated with susceptibility or resistance to pulmonary tuberculosis (PTB) in south Indian population. The polymorphisms in various CC chemokine genes, MCP‐1 (CCL2) [?2518A/G, 903C/T], MIP‐1α (CCL3) [?2021C/T, +740A/G] and MIP‐1β (CCL4) [?5725A/C] were studied in 295 healthy controls (HCs) and 303 patients with PTB using polymerase chain reaction‐based restriction fragment length polymorphism (PCR‐RFLP). The allele and genotype frequencies of CCL2, CCL3 and CCL4 were not different between HCs and patients with PTB. However, a significantly decreased frequency of CCL2 ?2518GG genotype was observed in male patients with PTB [P value = 0.015, P corrected (Bonferroni correction) Pc = 0.045, odds ratio (OR) 0.43 95% CI (0.21–0.86)], and a significantly increased frequency of the same genotype was observed among female patients with PTB [P value = 0.049, Pc = 0.147, OR 2.28 95% CI (1.00–5.27)]. The results suggest that ?2518GG genotype may be associated with protection in males and susceptibility to PTB in females. Moreover, we also observed differences in the haplotype frequencies of these chemokine genes between HCs and patients with PTB. However, these polymorphisms are not associated with disease independently, probably in combination with other genes, they may be associated with susceptibility or resistance to TB in south Indian population.     

Copy number variation and neuropsychiatric problems in females and males in the general population

Neurodevelopmental problems (NPs) are more common in males, whereas anxiety and depression are more common in females. Rare copy number variants (CNVs) have been implicated in neurodevelopmental disorders. The aim of this study was to characterize the relationship between rare CNVs with NPs, anxiety, and depression in a childhood population sample, as well as to examine sex‐specific effects. We analyzed a sample of N = 12,982 children, of whom 5.3% had narrowly defined NPs (clinically diagnosed), 20.9% had broadly defined NPs (based on validated screening measures, but no diagnosis), and 3.0% had clinically diagnosed anxiety or depression. Rare (<1% frequency) CNVs were categorized by size (100–500 kb or > 500 kb), type, and putative relevance to NPs. We tested for association of CNV categories with outcomes and examined sex‐specific effects. Medium deletions (OR[CI] = 1.18[1.05–1.33], p = .0053) and large duplications (OR[CI] = 1.45[1.19–1.75], p = .00017) were associated with broadly defined NPs. Large deletions (OR[CI] = 1.85[1.14–3.01], p = .013) were associated with narrowly defined NPs. There were no significant sex differences in CNV burden in individuals with NPs. Although CNVs were not associated with anxiety/depression in the whole sample, in individuals diagnosed with these disorders, females were more likely to have large CNVs (OR[CI] = 3.75[1.45–9.68], p = .0064). Rare CNVs are associated with both narrowly and broadly defined NPs in a general population sample of children. Our results also suggest that large, rare CNVs may show sex‐specific phenotypic effects.     

Effects of short‐term exposure to inhalable particulate matter on DNA methylation of tandem repeats

There is compelling evidence that particulate matter (PM) increases lung cancer risk by triggering systemic inflammation, and leukocyte DNA hypomethylation. However, previous investigations focused on repeated element sequences from LINE‐1 and Alu families. Tandem repeats, which display a greater propensity to mutate, and are often hypomethylated in cancer patients, have never been investigated in individuals exposed to PM. We measured methylation of three tandem repeats (SATα, NBL2, and D4Z4) by polymerase chain reaction–pyrosequencing on blood samples from truck drivers and office workers (60 per group) in Beijing, China. We used lightweight monitors to measure personal PM_2.5 (PM with aerodynamic diameter ≤2.5 µm) and elemental carbon (a tracer of PM from vehicular traffic). Ambient PM₁₀ data were obtained from air quality measuring stations. Overall, an interquartile increase in personal PM_2.5 and ambient PM₁₀ levels was associated with a significant covariate‐adjusted decrease in SATα methylation (?1.35% 5‐methyl cytosine [5mC], P = 0.01; and ?1.33%5mC; P = 0.01, respectively). Effects from personal PM_2.5 and ambient PM₁₀ on SATα methylation were stronger in truck drivers (?2.34%5mC, P = 0.02; ?1.44%5mC, P = 0.06) than office workers (?0.95%5mC, P = 0.26; ?1.25%5mC, P = 0.12, respectively). Ambient PM₁₀ was negatively correlated with NBL2 methylation in truck drivers (?1.38%5mC, P = 0.03) but not in office workers (1.04%5mC, P = 0.13). Our result suggests that PM exposure is associated with hypomethylation of selected tandem repeats. Measuring tandem‐repeat hypomethylation in easy‐to‐obtain blood specimens might identify individuals with biological effects and potential cancer risk from PM exposure. Environ. Mol. Mutagen. 55:322–335, 2014. © 2014 Wiley Periodicals, Inc.     

Oxidative stress and inflammation mediate the effect of air pollution on cardio‐ and cerebrovascular disease: A prospective study in nonsmokers

Air pollution is associated with a broad range of adverse health effects, including mortality and morbidity due to cardio‐ and cerebrovascular diseases (CCVD), but the molecular mechanisms involved are not entirely understood. This study aims to investigate the involvement of oxidative stress and inflammation in the causal chain, and to identify intermediate biomarkers that are associated retrospectively with the exposure and prospectively with the disease. We designed a case‐control study on CCVD nested in a cohort of 18,982 individuals from the EPIC‐Italy study. We measured air pollution, inflammatory biomarkers, and whole‐genome DNA methylation in blood collected up to 17 years before the diagnosis. The study sample includes all the incident CCVD cases among former‐ and never‐smokers, with available stored blood sample, that arose in the cohort during the follow‐up. We identified enrichment of altered DNA methylation in “ROS/Glutathione/Cytotoxic granules” and “Cytokine signaling” pathways related genes, associated with both air pollution (multiple comparisons adjusted p for enrichment ranging from 0.01 to 0.03 depending on pollutant) and with CCVD risk (P = 0.04 and P = 0.03, respectively). Also, Interleukin‐17 was associated with higher exposure to NO₂ (P = 0.0004), NO_x (P = 0.0005), and CCVD risk (OR = 1.79; CI 1.04–3.11; P = 0.04 comparing extreme tertiles). Our findings indicate that chronic exposure to air pollution can lead to oxidative stress, which in turn activates a cascade of inflammatory responses mainly involving the “Cytokine signaling” pathway, leading to increased risk of CCVD. Inflammatory proteins and DNA methylation alterations can be detected several years before CCVD diagnosis in blood samples, being promising preclinical biomarkers. Environ. Mol. Mutagen. 59:234–246, 2018. © 2017 Wiley Periodicals, Inc.     

Effects of G-CSF on telomere lengths in PBMCs from human immunodeficiency virus-infected patients: results from a randomized, placebo-controlled trial

Telomeres are unique terminal chromosomal structures, the length of which has been shown to decrease with cell division in vitro and with increased age in vivo for human somatic cells. In human immunodeficiency virus (HIV)‐1 infection, decrease of telomere length is primarily found in CD8⁺ T cells, and not in CD4⁺ T cells. In this double‐blind placebo‐controlled study, we investigated the effect of granulocyte colony stimulating factor (G‐CSF) treatment combined with highly active antiretroviral therapy (HAART) on mean telomere length in peripheral blood mononuclear cells (PBMC). The terminal restriction fragment (TRF) length showed no changes during G‐CSF treatment although the number of lymphocytes increased significantly. The mean TRF length correlated positively (R = 0.552, P = 0.009) and negatively (R = ?0.503, P = 0.02) to the proportion of CD4⁺ memory and naïve cells, respectively. Our data suggest that during G‐CSF treatment lymphocytes are recruited by a combination of central and peripheral proliferation.