Tobacco smoking and oxidative stress to DNA: a meta-analysis of studies using chromatographic and immunological methods

Maternal oxidative stress during pregnancy associated with emotional and behavioural problems in early childhood: implications for foetal programming

Childhood mental disorders, including emotional and behavioural problems (EBP) are increasingly prevalent. Higher maternal oxidative stress (OS) during pregnancy (matOSpreg) is linked to offspring mental disorders. Environmental factors contribute to matOSpreg. However, the role of matOSpreg in childhood EBP is unclear. We investigated the associations between (i) matOSpreg and offspring EBP; (ii) social and prenatal environmental factors and matOSpreg; and (iii) social and prenatal factors and childhood EBP and evaluated whether matOSpreg mediated these associations. Maternal urinary OS biomarkers, 8-hydroxyguanosine (8-OHGua; an oxidative RNA damage marker) and 8-hydroxy-2'-deoxyguanosine (8-OHdG; an oxidative DNA damage marker), at 36 weeks of pregnancy were quantified by liquid chromatography-mass spectrometry in a population-derived birth cohort, Barwon Infant Study (n = 1074 mother-infant pairs). Social and prenatal environmental factors were collected by mother-reported questionnaires. Offspring total EBP was measured by Child Behavior Checklist Total Problems T-scores at age two (n = 675) and Strengths and Difficulties Questionnaire Total Difficulties score at age four (n = 791). Prospective associations were examined by multivariable regression analyses adjusted for covariates. Mediation effects were evaluated using counterfactual-based mediation analysis. Higher maternal urinary 8-OHGua at 36 weeks (mat8-OHGua36w) was associated with greater offspring total EBP at age four (β = 0.38, 95% CI (0.07, 0.69), P = 0.02) and age two (β = 0.62, 95% CI (-0.06, 1.30), P = 0.07). Weaker evidence of association was detected for 8-OHdG. Five early-life factors were associated with both mat8-OHGua36w and childhood EBP (P-range < 0.001-0.05), including lower maternal education, socioeconomic disadvantage and prenatal tobacco smoking. These risk factor-childhood EBP associations were partly mediated by higher mat8-OHGua36w (P-range = 0.01-0.05). Higher matOSpreg, particularly oxidant RNA damage, is associated with later offspring EBP. Effects of some social and prenatal lifestyle factors on childhood EBP were partly mediated by matOSpreg. Future studies are warranted to further elucidate the role of early-life oxidant damage in childhood EBP.

Quantitation of oxidized nuclear and mitochondrial DNA in plasma samples of patients with abdominal aortic aneurysm

There is accumulating evidence that pro-inflammatory features are inherent to mitochondrial DNA and oxidized DNA species. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is the most frequently studied oxidatively generated lesion. Modified DNA reaches the circulation upon cell apoptosis, necrosis or neutrophil extracellular trap (NET) formation. Standard chromatography-based techniques for the assessment of 8-oxodGuo imply degradation of DNA to a single base level, thus precluding the attribution to a nuclear or mitochondrial origin. We therefore aimed to establish a protocol for the concomitant assessment of oxidized mitochondrial and nuclear DNA from human plasma samples. We applied immunoprecipitation (IP) for 8-oxodGuo to separate oxidized from non-oxidized DNA species and subsequent quantitative polymerase chain reaction (qPCR) to assign them to their subcellular source. The IP procedure failed when applied directly to plasma samples, i.e. isotype control precipitated similar amounts of DNA as the specific 8-oxodGuo antibody. In contrast, DNA isolation from plasma prior to the IP process provided assay specificity with little impact on DNA oxidation status. We further optimized sensitivity and efficiency of qPCR analysis by reducing amplicon length and targeting repetitive nuclear DNA elements. When the established protocol was applied to plasma samples of abdominal aortic aneurysm (AAA) patients and control subjects, the AAA cohort displayed significantly elevated circulating non-oxidized and total nuclear DNA and a trend for increased levels of oxidized mitochondrial DNA. An enrichment of mitochondrial versus nuclear DNA within the oxidized DNA fraction was seen for AAA patients. Regarding the potential source of circulating DNA, we observed a significant correlation of markers of neutrophil activation and NET formation with nuclear DNA, independent of oxidation status. Thus, the established method provides a tool to detect and distinguish the release of oxidized nuclear and mitochondrial DNA in human plasma and offers a refined biomarker to monitor disease conditions of pro-inflammatory cell and tissue destruction.

Association of Oxidative Stress-Induced Nucleic Acid Damage With Psychiatric Disorders in Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Nucleic acid damage from oxidative stress (NA-OXS) may be a molecular mechanism driving the severely increased morbidity and mortality from somatic causes in adults with psychiatric disorders.

OBJECTIVE

To systematically retrieve and analyze data on NA-OXS across the psychiatric disorder diagnostic spectrum.

DATA SOURCES

The PubMed, Embase, and PsycINFO databases were searched from inception to November 16, 2021. A hand search of reference lists of relevant articles was also performed.

STUDY SELECTION

Key study inclusion criteria in this meta-analysis were as follows: adult human study population, measurement of any marker of DNA or RNA damage from oxidative stress, and either a (1) cross-sectional design comparing patients with psychiatric disorders (any diagnosis) with a control group or (2) prospective intervention. Two authors screened the studies, and 2 senior authors read the relevant articles in full and assessed them for eligibility.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two authors performed data extraction independently, and a senior coauthor was consulted in cases of disagreement. Data were synthesized with random-effects and multilevel meta-analyses.

MAIN OUTCOMES AND MEASURES

The predefined hypothesis was that individuals with psychiatric disorders have increased NA-OXS levels. The main outcome was the standardized mean differences (SMDs) among patients and controls in nucleic acid oxidation markers compared across diagnostic groups. Analyses were divided into combinations of biological matrices and nucleic acids.

RESULTS

Eighty-two studies fulfilled the inclusion criteria, comprising 205 patient vs control group comparisons and a total of 10 151 patient and 10 532 control observations. Overall, the data showed that patients with psychiatric disorders had higher NA-OXS levels vs controls across matrices and molecules. Pooled effect sizes ranged from moderate for urinary DNA markers (SMD = 0.44 [95% CI, 0.20-0.68]; P < .001) to very large for blood cell DNA markers (SMD = 1.12 [95% CI, 0.69-1.55; P < .001). Higher NA-OXS levels were observed among patients with dementias followed by psychotic and bipolar disorders. Sensitivity analyses excluding low-quality studies did not materially alter the results. Intervention studies were few and too heterogenous for meaningful meta-analysis.

CONCLUSIONS AND RELEVANCE

The results of this meta-analysis suggest that there is an association with increased NA-OXS levels in individuals across the psychiatric disorder diagnostic spectrum. NA-OXS may play a role in the somatic morbidity and mortality observed among individuals with psychiatric disorders.

Associations between oxidative stress markers and patient-reported smartphone-based symptoms in patients newly diagnosed with bipolar disorder: An exploratory study

Oxidative stress generated nucleoside damage seems to represent key pathophysiological mechanisms of bipolar disorder (BD). Likewise, mood and activity are core features of BD and can be reliably monitored using smartphone-based applications. The aim was to investigate whether oxidative stress generated nucleoside damage could reflect psychopathology in BD using easily available and non-invasive patient-reported smartphone-based symptoms. We included 223 patients newly diagnosed with BD and employed linear mixed-effect regression models to associate baseline measurements of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) levels with patient-reported smartphone measures of mood, activity, anxiety, stress and sleep duration monitored three days prior to and 30 days after the baseline visit in the longitudinal Bipolar Illness Onset Study. In patients newly diagnosed with BD higher 8-oxoGuo levels were inversely associated with the patient-reported activity level (B = 0.953, 95%CI = 0.909;0.99, p = 0.043) and positively associated with patient-reported anxiety (B = 1.104, 95%CI = 1.022;1.161, p=0.012), perceived stress (B = 1.092, 95%CI = 1.009;1.183, p = 0.014) and sleep duration (B = 1.000, 95%CI = 1.000;1.001, p = 0.001), respectively, in analyses, adjusted for sex and age. The associations between 8-oxoGuo levels and anxiety, perceived stress and sleep duration, respectively, withstood adjustment for sex, age, smoking, BMI and alcohol intake. No associations between 8-oxodG levels and patient-reported smartphone-based data were found and mood was not associated with 8-oxoGuo. Oxidative stress was associated with patient-reported smartphone-based data on activity, anxiety, stress and sleep duration pointing towards that oxidative stress generated nucleoside damage may reflect ongoing psychopathology in BD.

Tea consumption and the risk of abdominal aortic aneurysm

BACKGROUND

Tea has the potential to lower the risk of abdominal aortic aneurysm (AAA) owing to its high antioxidant capacity. AAA risk factors including smoking, hypertension, and hypercholesterolaemia, may modify this association.

METHODS

The study population included 45 047 men in the Cohort of Swedish Men (COSM) and 36 611 women in the Swedish Mammography Cohort (SMC), aged 45-83 years at baseline. The COSM was established in 1997 with all men who lived in two central Swedish counties (Västmanland and Örebro), and the SMC was established in 1987-1990 with women residing in Västmanland county. Tea consumption was assessed by means of food frequency questionnaires in 1997 and 2009.

RESULTS

During 17.5 years of follow-up, 1781 AAA cases (1496 men, 285 women; 1497 non-ruptured, 284 ruptured) were ascertained via Swedish registers. Tea consumption was inversely associated with total AAA incidence in men and women. Women had a 23 (95 per cent c.i. 8 to 36) per cent lower risk of AAA per each cup per day increment, whereas men had a 9 (0 to 17) per cent lower risk (Pinteraction = 0.029). Tea consumption was associated with a lower risk of both non-ruptured (hazard ratio (HR) 0.93, 95 per cent c.i. 0.85 to 1.01) and ruptured (HR 0.84, 0.71 to 0.98) AAA. Smoking status modified the association (Pinteraction < 0.001), whereby tea consumption was associated with lower risk of AAA in ex-smokers (per cup per day, HR 0.89, 0.80 to 0.98) and in never smokers (HR 0.88, 0.77 to 1.00), but not in current smokers (HR 0.95, 0.84 to 1.06). Tea consumption was associated with a lower risk in participants with (HR 0.88, 0.80 to 0.98) and without (HR 0.93, 0.88 to 1.00) hypertension, and in those with (HR 0.82, 0.67 to 1.01) and without (HR 0.92, 0.86 to 0.98) hypercholesterolaemia.

CONCLUSION

Tea consumption was associated with a reduced risk of AAA. The association was more pronounced for ruptured than non-ruptured AAA, and in patients with hypertension and hypercholesterolaemia than those without. The association was also observed in ex-smokers and never smokers, but not in current smokers.

Markers of oxidative stress and toxicant exposure among young waterpipe smokers in the USA

Waterpipe (aka hookah) tobacco smokers are exposed to toxicants that can lead to oxidative DNA and RNA damage, a precursor to chronic disease formation. This study assessed toxicant exposure and biomarkers of DNA [8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG)] and RNA [8-oxo-7,8-dihydroguanosine (8-oxoGuo)] oxidative damage during smoking of flavored and non-flavored waterpipe tobacco. Thirty waterpipe smokers completed two counterbalanced 2-h lab waterpipe smoking sessions (flavored vs. non-flavored waterpipe tobacco). Urinary concentrations of 8-oxodG and 8-oxoGuo and expired carbon monoxide (eCO) were measured before and after the smoking sessions. A significant increase in the urinary concentrations of 8-oxodG (from 2.12 ± 0.83 to 2.35 ± 0.91 ng/mg creatinine, p = 0.024) and 8-oxoGuo (from 2.96 ± 0.84 to 3.45 ± 0.76 ng/mg creatinine, p = 0.003) were observed after smoking the non-flavored and flavored waterpipe tobacco, respectively. Our results also showed that the mean ± SD of eCO increased significantly after smoking the flavored (from 1.3 ± 1.1 to 20.3 ± 23.6 ppm, p < 0.001) and non-flavored waterpipe tobacco (from 1.8 ± 1.2 to 24.5 ± 26.1 ppm, p < 0.001). There were no significant differences in the means of 8-oxodG (p = 0.576), 8-oxoGuo (p = 0.108), and eCO (p = 0.170) between the flavored and non-flavored tobacco sessions. Smoking non-flavored and flavored waterpipe tobacco leads to oxidative stress and toxicant exposure. Our findings add to the existing evidence about the adverse effects of waterpipe tobacco smoking (WTS) and the need for strong policies to inform and protect young people from the risks of WTS.

Oxidative Dysregulation in Early Life Stress and Posttraumatic Stress Disorder: A Comprehensive Review

Traumatic stress may chronically affect master homeostatic systems at the crossroads of peripheral and central susceptibility pathways and lead to the biological embedment of trauma-related allostatic trajectories through neurobiological alterations even decades later. Lately, there has been an exponential knowledge growth concerning the effect of traumatic stress on oxidative components and redox-state homeostasis. This extensive review encompasses a detailed description of the oxidative cascade components along with their physiological and pathophysiological functions and a systematic presentation of both preclinical and clinical, genetic and epigenetic human findings on trauma-related oxidative stress (OXS), followed by a substantial synthesis of the involved oxidative cascades into specific and functional, trauma-related pathways. The bulk of the evidence suggests an imbalance of pro-/anti-oxidative mechanisms under conditions of traumatic stress, respectively leading to a systemic oxidative dysregulation accompanied by toxic oxidation byproducts. Yet, there is substantial heterogeneity in findings probably relative to confounding, trauma-related parameters, as well as to the equivocal directionality of not only the involved oxidative mechanisms but other homeostatic ones. Accordingly, we also discuss the trauma-related OXS findings within the broader spectrum of systemic interactions with other major influencing systems, such as inflammation, the hypothalamic-pituitary-adrenal axis, and the circadian system. We intend to demonstrate the inherent complexity of all the systems involved, but also put forth associated caveats in the implementation and interpretation of OXS findings in trauma-related research and promote their comprehension within a broader context.

Higher systemic oxidatively generated DNA and RNA damage in patients with newly diagnosed bipolar disorder and their unaffected first-degree relatives

BACKGROUND

Prior studies in bipolar disorders (BD) have suggested that oxidative stress and cellular ageing play a key role in the pathophysiology of BD. Nevertheless, oxidative stress has not been investigated in patients with newly diagnosed BD and in their unaffected first-degree relatives (UR), compared with healthy control individuals (HC).

METHODS

We investigated the level of systemic oxidative damage to DNA and RNA measured by urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) levels, respectively, in 360 patients with newly diagnosed BD, 92 of their UR and 197 HC.

RESULTS

Independent of lifestyle and demographic variables, levels of both 8-oxoGuo and 8-oxodG was 17.1% (B = 1.171, 95%CI = 1.125-1.219, p < 0.001) and 21.2% (B = 1.212, 95%CI = 1.145-1.283, p < 0.001) higher, respectively, in patients with BD compared with HC and 13.3% (B = 1.133, 95%CI = 1.069-1.200, p < 0.001) and 26.6% (B = 1.266, 95%CI = 1.167-1.374, p < 0.001) higher, respectively, in UR compared with HC. Neither 8-oxoGuo nor 8-oxodG levels differed between patients with BD and UR. These findings were replicated in patients in full or partial remission and were consistent both in BD type I and II.

CONCLUSION

Overall, the findings of higher oxidative stress in patients with newly diagnosed BD and their UR suggest that systemic nucleoside damage by oxidative stress is present prior to onset and in the early stages of BD thereby potentially representing trait markers of BD.

Lifestyle in urology: Benign diseases

Modifiable lifestyle-related risk factors are the object of increasing attention, with a view to primary and tertiary prevention, to limit the onset and development of diseases.Also in the urological field there is accumulating evidence of the relationship between urological diseases and lifestyle-related risk factors that can influence their incidence and prognosis. Risk factors such as nutrition, physical activity, sexual habits, tobacco smoking, or alcohol consumption can be modified to limit morbidity and reduce the social impact and the burdensome costs associated with diagnosis and treatment.This review synthesizes the current clinical evidence available on this topic, trying to satisfy the need for a summary on the relationships between the most important lifestyle factors and the main benign urological diseases, focusing on benign prostatic hyperplasia (BPH), infections urinary tract (UTI), urinary incontinence (UI), stones, erectile dysfunction, and male infertility.

Biomarkers of nucleic acid oxidation - A summary state-of-the-art

Oxidatively generated damage to DNA has been implicated in the pathogenesis of a wide variety of diseases. Increasingly, interest is also focusing upon the effects of damage to the other nucleic acids, RNA and the (2′-deoxy-)ribonucleotide pools, and evidence is growing that these too may have an important role in disease. LC-MS/MS has the ability to provide absolute quantification of specific biomarkers, such as 8-oxo-7,8-dihydro-2′-deoxyGuo (8-oxodG), in both nuclear and mitochondrial DNA, and 8-oxoGuo in RNA. However, significant quantities of tissue are needed, limiting its use in human biomonitoring studies. In contrast, the comet assay requires much less material, and as little as 5 μL of blood may be used, offering a minimally invasive means of assessing oxidative stress in vivo, but this is restricted to nuclear DNA damage only. Urine is an ideal matrix in which to non-invasively study nucleic acid-derived biomarkers of oxidative stress, and considerable progress has been made towards robustly validating these measurements, not least through the efforts of the European Standards Committee on Urinary (DNA) Lesion Analysis. For urine, LC-MS/MS is considered the gold standard approach, and although there have been improvements to the ELISA methodology, this is largely limited to 8-oxodG. Emerging DNA adductomics approaches, which either comprehensively assess the totality of adducts in DNA, or map DNA damage across the nuclear and mitochondrial genomes, offer the potential to considerably advance our understanding of the mechanistic role of oxidatively damaged nucleic acids in disease.

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Oxidatively damaged nucleic acids are implicated in the pathogenesis of disease.

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LC-MS/MS, comet assay and ELISA are often used to study oxidatively damaged DNA.

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Urinary oxidatively damaged nucleic acids non-invasively reflect oxidative stress.

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DNA adductomics will aid understanding the role of ROS damaged DNA in disease.

[Prevalence of male infertility in a university hospital in Morocco]

INTRODUCTION

infertility in couples has become a public health problem in recent years. It can be related to a problem in the male, female or both. Men infertility accounts for 40% of cases. In Morocco, most studies have focused on the causes and risk factors for male infertility. The purpose of our study was to assess the prevalence of male infertility and semen parameters in infertile men or in men at high risk of developing infertility in a tertiary hospital in Rabat.

METHODS

we conducted an analysis of 482 patients referred for evaluation of infertility in the couple or as part of preoperative assessment of varicocele or testicular ectopia. Demographic data, risk factors for infertility, primary or secondary infertility were recorded for each patient. Semen parameters were assessed and interpreted according to WHO standards updated in 2010 based on studies of factors associated with their disturbance.

RESULTS

the average age of patients was 35.35±8.81 years. Primary infertility was found in 61.8% of cases. The most common risk factors for infertility were tobacco followed by varicocele and infection. Spermogram was altered in 53.1% of cases. The most common abnormality was sperm vitality issues (36.9%) followed by spermatic concentration (29.7%) and morphology (29.3%). Age was the unique factor which had a significant impact on spermogram (p=0.002). Abnormalities in mobility were detected in patients ≥31 years, sperm vitality issues in patients aged 34 years, abnormalities in morphology in patients aged 35 years and concentration in patients aged 37 years. Azoospermia was found in 16.4% of cases and was mainly associated with primary infertility. Oligo-astheno-teratozoospermia was the most common association (26.2%).

CONCLUSION

male infertility is common in our context. The major risk factor is age. Mobility is the earliest parameter achieved.

The effect of different tobacco tar levels on DNA damage in cigarette smoking subjects

Objective

To explore the genetic damage caused by different tar levels in the human body.

Methods

The subjects were divided into high, medium and low (12 mg, 8 mg, 5 mg) tar groups according to the tar levels. Nonsmoking populations served as a control group. 2 ml of peripheral blood was collected on the 10th day after morning fasting. Oxidative and genetic toxicological damage indicators were analysed with enzyme-linked immunosorbent assay, cytokinesis-block micronucleus assay in human lymphocyte and single cell gel electrophoresis.

Results

The distribution of hOGG1 concentration was significantly different within all groups, P < 0.01. The concentrations of cotinine, 8-OHdG and Rap-2b were significantly differences between control and medium tar group, control and high tar group, low and medium tar group and low and high tar group, respectively, P < 0.05. The level of PAH-DNA adducts was not significantly changed in the middle tar group and high tar group, P > 0.05. The level of CRP was significantly changed between control and high tar group, low and high tar group and medium and high tar group, respectively, P < 0.0001. The rate of comet tailing was significantly different between all groups. The rate of micronucleus cells was not significantly different between all groups.

Conclusions

The increase of tar content could increase the DNA damage to a certain extent, so the intake of tar content should be monitored.

Interventions targeted at oxidatively generated modifications of nucleic acids focused on urine and plasma markers

Oxidative stress is associated with the development and progression of numerous diseases. However, targeting oxidative stress has not been established in the clinical management of any disease. Several methods and markers are available to measure oxidative stress, including direct measurement of free radicals, antioxidants, redox balance, and oxidative modifications of cellular macromolecules. Oxidatively generated nucleic acid modifications have attracted much interest due to the pre-mutagenic oxidative modification of DNA into 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), associated with cancer development. During the last decade, the perception of RNA has changed from that of a 'silent messenger' to an 'active contributor', and, parallelly oxidatively generated RNA modifications measured as 8-oxo-7,8-dihydro-guanosine (8-oxoGuo), has been demonstrated as a prognostic factor for all-caused and cardiovascular related mortality in patients with type 2 diabetes. Several attempts have been made to modify the amount of oxidative nucleic acid modifications. Thus, this review aims to introduce researchers to the measurement of oxidatively generated nucleic acid modifications as well as critically review previous attempts and provide future directions for targeting oxidatively generated nucleic acid modifications.

Oxidatively generated modifications to nucleic acids in vivo: Measurement in urine and plasma

BACKGROUND

The oxidized guanine nucleosides, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), derived from DNA and RNA, respectively, were used to investigate the importance of oxidative stress to nucleic acids in vivo. High urinary excretion of 8-oxodG is associated with cancer development, whereas high urinary excretion of 8-oxoGuo is associated with mortality in type 2 diabetes. Like creatinine, these small water-soluble molecules are not reabsorbed in the kidney. Therefore, 8-oxo nucleoside/creatinine reciprocal concentration ratios are identical in plasma and urine. The total amount of 8-oxo guanine nucleosides excreted by the kidneys is the product of plasma concentration and glomerular filtration rate.

METHODS

With relevant equations and an estimated glomerular filtration rate, the 24-h urinary excretion of 8-oxodG and 8-oxoGuo was calculated in 2679 subjects with type 2 diabetes, displaying good correlation with the measured urinary 8-oxo nucleoside/creatinine ratio: DNA oxidation r = 0.86 and RNA oxidation r = 0.84 (p < 0.05 for both).

RESULTS

Survival analyses based on the quartiles of the 8-oxodG/creatinine ratio and the quartiles of calculated 24-h urinary excretion rate of the 2679 subjects gave similar hazard ratio estimates for death due to all causes. This finding was similar for the 8-oxoGuo hazard ratio estimates.

CONCLUSIONS

This study shows that oxidatively generated modifications to DNA and RNA in vivo can be measured using 1) a spot urine sample, normalized to urinary creatinine, 2) 24-h urine, or 3) a single plasma sample based on concentrations of 8-oxo nucleoside and creatinine and glomerular filtration rate.

Epigenetic Transgenerational Inheritance

Epigenetic information refers to heritable changes in gene expression that occur without modifications at the DNA sequence level. These changes are orchestrated by different epigenetic mechanisms such as DNA methylation, posttranslational modifications of histones, and the presence of noncoding RNAs. Epigenetic information regulates chromatin structure to confer cell-specific gene expression.The sperm epigenome is the result of three periods of global resetting during men's life. Germ cell epigenome reprogramming is designed to allow cell totipotency and to prevent the transmission of epimutations via spermatozoa. At the end of these reprogramming events, the sperm epigenome has a very specific epigenetic pattern that is a footprint of past reprogramming events and has an influence on embryo development.Several data demonstrate that not all regions of the epigenome are erased during the reprogramming periods, suggesting the transmission of epigenetic information from fathers to offspring via spermatozoa. Moreover, it is becoming increasingly clear that the sperm epigenome is sensitive to environmental factors during the process of gamete differentiation, suggesting the plasticity of the sperm epigenetic signature according to the circumstances of the individual's life.In this chapter, we provided strong evidences about the association between variations of the sperm epigenome and the exposure to environmental factors. Moreover, we will present data about how epigenetic mechanisms are candidates for transferring paternal environmental information to offspring.

Cross-sectional and longitudinal associations between serum 25‑hydroxyvitamin D and anti-oxidative status in older adults

OBJECTIVE

Emerging evidence indicates that vitamin D has anti-oxidative properties. The present study investigates whether serum 25‑hydroxyvitamin D [25(OH)D] is associated with biomarkers of anti-oxidative status in community-dwelling older adults using cross-sectional and longitudinal data.

METHODS

A total of 302 subjects aged 62 to 92 years from Germany (50.6°N) were analysed via cross-sectional approach. For longitudinal analysis, data of 153 subjects were available. Fasting blood samples from 2004 and 2012 were analysed for 25(OH)D concentrations, total anti-oxidative status (TAOS) as well as anti-oxidative enzymes, such as catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). Multiple regression analyses were performed to examine the associations between 25(OH)D and parameters of anti-oxidative status.

RESULTS

In cross-sectional analyses, 25(OH)D was a significant predictor of CAT (β = -0.166; P = 0.010), lg₁₀ GPx (β = 0.136; P = 0.037) and TAOS (β = 0.121; P = 0.048) after adjusting for age, sex, percentage total body fat (TBF), month of blood sampling, smoking behaviour and use of vitamin D supplements. Longitudinal change in 25(OH)D concentration positively predicted change in TAOS (β = 0.224; P = 0.006) after adjusting for sex, baseline TAOS, age, smoking behaviour, use of vitamin D supplements and change in TBF, physical activity level, current time spent outdoors and dietary vitamin D intake.

CONCLUSION

The maintenance of an adequate vitamin D status may have a beneficial impact on the anti-oxidative defence system in older adults on a long-term perspective.

Sulforaphane Augments Glutathione and Influences Brain Metabolites in Human Subjects: A Clinical Pilot Study

Schizophrenia and other neuropsychiatric disorders await mechanism-associated interventions. Excess oxidative stress is increasingly appreciated to participate in the pathophysiology of brain disorders, and decreases in the major antioxidant, glutathione (GSH), have been reported in multiple studies. Technical cautions regarding the estimation of oxidative stress-related changes in the brain via imaging techniques have led investigators to explore peripheral GSH as a possible pathological signature of oxidative stress-associated brain changes. In a preclinical model of GSH deficiency, we found a correlation between whole brain and peripheral GSH levels. We found that the naturally occurring isothiocyanate sulforaphane increased blood GSH levels in healthy human subjects following 7 days of daily oral administration. In parallel, we explored the potential influence of sulforaphane on brain GSH levels in the anterior cingulate cortex, hippocampus, and thalamus via 7-T magnetic resonance spectroscopy. A significant positive correlation between blood and thalamic GSH post- and pre-sulforaphane treatment ratios was observed, in addition to a consistent increase in brain GSH levels in response to treatment. This clinical pilot study suggests the value of exploring relationships between peripheral GSH and clinical/neuropsychological measures, as well as the influences sulforaphane has on functional measures that are altered in neuropsychiatric disorders.

Oxidatively-induced DNA damage and base excision repair in euthymic patients with bipolar disorder

Oxidatively-induced DNA damage has previously been associated with bipolar disorder. More recently, impairments in DNA repair mechanisms have also been reported. We aimed to investigate oxidatively-induced DNA lesions and expression of DNA glycosylases involved in base excision repair in euthymic patients with bipolar disorder compared to healthy individuals. DNA base lesions including both base and nucleoside modifications were measured using gas chromatography-tandem mass spectrometry and liquid chromatography-tandem mass spectrometry with isotope-dilution in DNA samples isolated from leukocytes of euthymic patients with bipolar disorder (n = 32) and healthy individuals (n = 51). The expression of DNA repair enzymes OGG1 and NEIL1 were measured using quantitative real-time polymerase chain reaction. The levels of malondialdehyde were measured using high performance liquid chromatography. Seven DNA base lesions in DNA of leukocytes of patients and healthy individuals were identified and quantified. Three of them had significantly elevated levels in bipolar patients when compared to healthy individuals. No elevation of lipid peroxidation marker malondialdehyde was observed. The level of OGG1 expression was significantly reduced in bipolar patients compared to healthy individuals, whereas the two groups exhibited similar levels of NEIL1 expression. Our results suggest that oxidatively-induced DNA damage occurs and base excision repair capacity may be decreased in bipolar patients when compared to healthy individuals. Measurement of oxidatively-induced DNA base lesions and the expression of DNA repair enzymes may be of great importance for large scale basic research and clinical studies of bipolar disorder.

Do Glutathione S-Transferase Genes Modify the Link between Indoor Air Pollution and Asthma, Allergies, and Lung Function? A Systematic Review

PURPOSE OF REVIEW

Glutathione S-transferase (GST) genes are involved in oxidative stress management and may modify the impact of indoor air pollution. We aimed to assess the influence of GST genes on the relationship between indoor air pollution and allergy/lung function.

RECENT FINDINGS

Our systematic review identified 22 eligible studies, with 15 supporting a gene-environment interaction. Carriers of GSTM1/T1 null and GSTP1 val genotypes were more susceptible to indoor air pollution exposures, having a higher risk of asthma and lung function deficits. However, findings differed in terms of risk alleles and specific exposures. High-exposure heterogeneity precluded meta-analysis. We found evidence that respiratory effects of indoor air pollution depend on the individual's GST profile. This may help explain the inconsistent associations found when gene-environment interactions are not considered. Future studies should aim to improve the accuracy of pollution assessment and investigate this finding in different populations.

DNA redox modulations and global DNA methylation in bipolar disorder: Effects of sex, smoking and illness state

DNA redox modulations and methylation have been associated with bipolar disorder (BD) pathophysiology. We aimed to investigate DNA redox modulation and global DNA methylation and demethylation levels in patients with BD during euthymia, mania or depression in comparison to non-psychiatric controls. The roles of sex and smoking as susceptibility factors for DNA redox modulations and global DNA methylation and demethylation were also explored. Levels of 5-methylcytosine (5-mC), 5-hydroxymethylcytosine (5-hmC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were assessed in DNA samples of 75 patients with DSM-IV BD type I (37 euthymic, 18 manic, 20 depressive) in comparison to 60 non-psychiatric controls. Levels of 5-mC and 5-hmC were assessed using Dot Blot as a screening process, and verified using ELISA. Levels of 8-OHdG were assessed using ELISA. The levels of 8-OHdG significantly differed among non-psychiatric control, euthymia, mania and depression groups [F (3,110) = 2.771, p = 0.046], whereas there were no alterations in the levels of 5-hmC and 5-mC. Linear regression analyses revealed the significant effects of smoking (p = 0.031) and sex (p = 0.012) as well as state of illness on the levels of 8-OHdG (p = 0.025) in patients with BD. Our results suggest that levels of 8-OHdG may be affected by sex, illness states and smoking in BD.

Impact of alcohol and cigarette smoking consumption in male fertility potential: Looks at lipid peroxidation, enzymatic antioxidant activities and sperm DNA damage

Alcohol intake and cigarette smoking are the major lifestyle factors with negative impact on fertility. We were interested to evaluate the negative impact of these factors on oxidative stress (OS), enzymatic antioxidant activity (EAO) of spermatozoa and on its DNA damage. This study included 108 male infertile patients with normal range of sperm conventional parameters but with unexplained infertility in assisted reproductive technologies programme. Firstly, OS was analysed based on lipid peroxidation (MDA) and EAO which included catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR). Secondly, we evaluated DNA fragmentation by TUNEL assay and chromatin decondensation by aniline blue colouration. The whole lot was divided into four groups: control (nonalcoholic and nonsmoker patients), alcohol group, smoking group and alcohol-smoking group. The results showed, in three last groups compared to control an increased CAT, SOD and GR activities with high MDA level especially in smoking and alcohol-smoking group. The latter showed the highest values of DNA fragmentation and chromatin decondensation (31% and 39%) to exceed DNA damage normal range. Indeed, smoking and alcohol intake lead to increase EAO due to long-term unbalanced antioxidant/oxidation ratio with high OS which cause consequently sperm DNA damage calling in need by urgency to change the lifestyle behaviour.

DNA damage levels in electronics workers in Southern China: A micro-whole blood comet assay

We evaluated DNA damage levels of different categories of workers exposed to hazards inside electronics factories in Southern China. To find out the most dangerous risk factor, a cross-sectional study was conducted on a total of 584 exposed subjects and 138 controls in an electronics factory in Southern China, where the electronics industry is prevalent. The exposed hazards included isopropanol (IPO), lead, noise, video display terminals (VDT), lead in a high-temperature (high-temp) environment, and IPO in a high-temp environment. DNA damage detection was performed by the micro-whole blood comet assay using peripheral blood. DNA damage levels were estimated by percent tail DNA (%T). Linear regression models were used to test DNA damage differences between exposed groups and control group with adjustments for potential confounding factors. The level of DNA damage was more significant in both lead in a high-temp and IPO in a high-temp environment groups than in that of the controls (p<0.05). The differences remained significant after stratifying by smoking status (p<0.05). There were no significant differences between groups exposed to IPO, lead, noise, VDT environment and controls. In conclusion, we identified potential risk factors for DNA damage to electronics workers. Special attention should be paid to workers exposed to IPO and lead in a high-temp environment.

Nanoparticle exposures from nano-enabled toner-based printing equipment and human health: state of science and future research needs

Toner formulations used by laser printers (LP) and photocopiers (PC), collectively called "toner-based printing equipment" (TPE), are nano-enabled products (NEP) because they contain several engineered nanomaterials (ENM) that improve toner performance. It has been shown that during consumer use (printing), these ENM are released in the air, together with other semi-volatile organic nanoparticles, and newly formed gaseous co-pollutants such as volatile organic compounds (VOC). The aim of this review is to detail and analyze physico-chemical and morphological (PCM), as well as the toxicological properties of particulate matter (PM) emissions from TPE. The review covers evolution of science since the early 2000, when this printing technology first became a subject of public interest, as well as the lagging regulatory framework around it. Important studies that have significantly changed our understanding of these exposures are also highlighted. The review continues with a critical appraisal of the most up-to-date cellular, animal and human toxicological evidence on the potential adverse human health effects of PM emitted from TPE. We highlight several limitations of existing studies, including (i) use of high and often unrealistic doses in vitro or in vivo; (ii) unrealistically high-dose rates in intratracheal instillation studies; (iii) improper use of toners as surrogate for emitted nanoparticles; (iv) lack of or inadequate PCM characterization of exposures; and (v) lack of dosimetry considerations in in vitro studies. Presently, there is compelling evidence that the PM_0.1 from TPE are biologically active and capable of inducing oxidative stress in vitro and in vivo, respiratory tract inflammation in vivo (in rats) and in humans, several endpoints of cellular injury in monocultures and co-cultures, including moderate epigenetic modifications in vitro. In humans, limited epidemiological studies report typically 2-3 times higher prevalence of chronic cough, wheezing, nasal blockage, excessive sputum production, breathing difficulties, and shortness of breath, in copier operators relative to controls. Such symptoms can be exacerbated during chronic exposures, and in individuals susceptible to inhaled pollutants. Thus respiratory, immunological, cardiovascular, and other disorders may be developed following such exposures; however, further toxicological and larger scale molecular epidemiological studies must be done to fully understand the mechanism of action of these TPE emitted nanoparticles. Major research gaps have also been identified. Among them, a methodical risk assessment based on "real world" exposures rather than on the toner particles alone needs to be performed to provide the much-needed data to establish regulatory guidelines protective of individuals exposed to TPE emissions at both the occupational and consumer level. Industry-wide molecular epidemiology as well as mechanistic animal and human studies are also urgently needed.

Associations of self-reported smoking, cotinine levels and epigenetic smoking indicators with oxidative stress among older adults: a population-based study

Tobacco smoking and oxidative stress (OS) are both related to a wide spectrum of adverse age-related health outcomes, but their association is not yet well-established. We examined the associations of self-reported smoking indicators, serum cotinine levels and smoking-related DNA methylation biomarkers with two urinary proxy markers of OS, 8-isoprostane (8-iso) and 8-hydroxy-2'-deoxyguanosine (8-oxodG), in two independent subsets of older adults recruited in Germany (discovery set: n = 978, validation set: n = 531). We obtained DNA methylation profiles in whole blood samples by Illumina Human Methylation450K Beadchip and measured the urinary levels of both OS markers using commercial ELISA kits. After controlling for potential confounders, current smoking, cumulative smoking exposure (pack-years) and serum cotinine levels (ng/ml) were strongly associated with 8-iso levels (p values <0.0001, 0.004 and 0.001, respectively). Of 151 previously identified smoking-related CpG sites, 71 loci were associated with 8-iso levels after correction for multiple testing (FDR < 0.05) in the validation phase and were designated as loci related to 8-iso levels defined OS. In addition, serum cotinine levels, cumulative smoking exposure and a smoking index (SI) based on the 71 identified loci manifested monotonic associations with 8-iso levels. However, we did not observe any associations between these smoking indicators and 8-oxodG levels. In conclusion, this study suggests that smoking-related epigenetic alterations are closely correlated with smoking-induced OS. The identified CpG sites could potentially be prognostic epigenetic markers of OS and OS-related health outcomes. Our findings and the underlying mechanisms should be followed up in further, preferably longitudinal studies.

Tobacco and diabetes: clinical relevance and approach to smoking cessation in diabetic smokers

Smoking is, together with diabetes mellitus, one of the main risk factors for cardiovascular disease. Diabetic patients have unique features and characteristics, some of which are not well known, that cause smoking to aggravate the effects of diabetes and impose difficulties in the smoking cessation process, for which a specificand more intensive approach with stricter controls is required. This review details all aspects with a known influence on the interaction between smoking and diabetes, both as regards the increased risk of macrovascular and microvascular complications of diabetes and the factors with an impact on the results of smoking cessation programs. The treatment guidelines for these smokers, including the algorithms and drug treatment patterns which have proved most useful based on scientific evidence, are also discussed.

The effect of smoking on the urinary excretion of 8-oxodG and 8-oxoGuo in patients with type 2 diabetes

Over the past decades, attention has been paid to understanding the impact of oxidative stress and related modifications of DNA and RNA on various human health risks. A recent meta-analysis comprising 1915 smokers and 3462 non-smokers found a significantly higher level of DNA oxidation measured as urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) excretion in smokers compared with non-smokers in a healthy population. We aimed to investigate if an increased urinary excretion of 8-oxodG in smokers versus never smokers and former smokers could be verified in a population with type 2 diabetes. Additionally, we measured RNA oxidation levels through urinary excretion of 8-oxo-7, 8-dihydroguanosine (8-oxoGuo). Our study included urinary samples from 2721 type 2 diabetic patients, analyzed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Logistic regression was used to examine the relationship between daily smokers (n = 462) versus former (n = 1341) and never smokers (n = 918) regarding the RNA and DNA oxidation, respectively. We did not find any significant effect of smoking on urinary excretion of 8-oxodG or 8-oxoGuo in our study. Due to a sparse study area, it is still too early to draw any conclusions on smoking and RNA-oxidation. Regarding DNA oxidation, our study suggests that the effect of smoking seen in healthy populations might be attenuated in patients with type 2 diabetes.