Relationship between DNA damage, total antioxidant capacity and coronary artery disease

DNA damage response, a double-edged sword for vascular aging

Vascular aging is a major risk factor for age-related cardiovascular diseases, which have high rates of morbidity and mortality. It is characterized by changes in the blood vessels, such as macroscopically increased vascular diameter and intima-medial thickness, chronic inflammation, vascular calcification, arterial stiffening, and atherosclerosis. DNA damage and the subsequent various DNA damage response (DDR) pathways are important causative factors of vascular aging. Deficient DDR, which may result in the accumulation of unrepaired damaged DNA or mutations, can lead to vascular aging. On the other hand, over-activation of some DDR proteins, such as poly (ADP ribose) polymerase (PARP) and ataxia telangiectasia mutated (ATM), also can enhance the process of vascular aging, suggesting that DDR can have both positive and negative effects on vascular aging. Despite the evidence reviewed in this paper, the role of DDR in vascular aging and potential therapeutic targets remain poorly understood and require further investigation.

DNA damage response signaling: A common link between cancer and cardiovascular diseases

DNA damage response (DDR) signaling ensures genomic and proteomic homeostasis to maintain a healthy genome. Dysregulation either in the form of down- or upregulation in the DDR pathways correlates with various pathophysiological states, including cancer and cardiovascular diseases (CVDs). Impaired DDR is studied as a signature mechanism for cancer; however, it also plays a role in ischemia-reperfusion injury (IRI), inflammation, cardiovascular function, and aging, demonstrating a complex and intriguing relationship between cancer and pathophysiology of CVDs. Accordingly, there are increasing number of reports indicating higher incidences of CVDs in cancer patients. In the present review, we thoroughly discuss (1) different DDR pathways, (2) the functional cross talk among different DDR mechanisms, (3) the role of DDR in cancer, (4) the commonalities and differences of DDR between cancer and CVDs, (5) the role of DDR in pathophysiology of CVDs, (6) interventional strategies for targeting genomic instability in CVDs, and (7) future perspective.

Paraquat induced oxidative stress, DNA damage, and cytotoxicity in lymphocytes

Paraquat (PQ) is a herbicide belonging to the group of bipyridylium salts. The objective of this study was to evaluate oxidative stress, DNA damage, and cytotoxicity induced by paraquat in peripheral lymphocyte cells in vivo as well as pathological changes in various tissues. For this purpose, 28 male Wistar rats in 6 different groups were poisoned by paraquat gavage and blood samples were taken from the hearts of rats after during the poisoning period. Oxidative stress, DNA damage, cell membrane integrity, serum lactate dehydrogenase, and cytotoxicity, were investigated by Ferric Reducing Antioxidant Potential (FRAP) test, alkaline comet assay, measuring serum lactate dehydrogenase (LDH), Hoechst staining and flow cytometry with propidium iodide (PI) respectively. The lung, kidney, and liver tissues were also examined pathologically. Paraquat caused dose-dependent DNA damage in peripheral lymphocyte cells and significant oxidative cell membrane damage. The most damage was caused by a single dose of 200 mg/kg b.w of paraquat by gavage. The gradual exposure to a dose of 300 mg/kg b.w of paraquat showed less damage, which could be due to the activation of the antioxidant defense mechanism.

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Paraquat induced oxidative stress.

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Paraquat increases serum lactate dehydrogenase.

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Oxidative stress Inducted by exposure to paraquat Inducted DNA damage.

Antioxidant potential of diet – Association between dietary antioxidant index and odds of coronary heart disease: A case-control study

BACKGROUND: Oxidative stress and chronic inflammation are among the leading causes of coronary heart disease (CHD). Studies investigated the relationship between dietary antioxidants and the risk/odds of CHD, and contradictory results have been reported. Dietary antioxidant index (DAI) is a novel and reliable nutritional tool that examines the diet’s overall antioxidant capacity. Its validity was examined using serum total antioxidant capacity and malondialdehyde. OBJECTIVE: This study aimed to investigate the relationship between DAI score and odds of CHD. METHODS: In this incidence case-control study, 320 individuals with a definitive diagnosis of CHD and 320 participants without CHD or related risk factors attending the same hospitals/polyclinics were selected as the case and control groups. We estimated the DAI by summing up six standardized intakes of major dietary antioxidants, including manganese, vitamin E, A, C, selenium, and zinc. RESULTS: Modeling DAI categorized according to the median (–0.38), in multi-adjusted model showed a significant protective association with the odd of CHD (OR = 0.72; 95%CI:0.51–0.99, p-value = 0.05). Also, modeling DAI as a continuous variable in multi-adjusted models (OR = 0.94;95%CI:0.90–0.95; p-value = 0.01) showed significant results. CONCLUSION: Using the DAI to investigate the relationship between dietary antioxidants and CHD can show more realistic results than a single study of antioxidants.

The relationship among noise, total oxidative status and DNA damage

PURPOSE

Noise is one of the major environmental health problems and is defined as any unpleasant sound. It was shown that prolonged exposure to noise was associated with progress of diseases. There is no study evaluating the effect of noise on the oxidative parameters of Total Antioxidant Capacity (TAC), Total Oxidant Status (TOS) and DNA damage.

AIM

This study aimed to evaluate the effect of noise on TOS, TAC and DNA damage.

METHODS

In this study, we included 100 textile factory workers affected by noise as a noise group, and 56 healthy volunteers employed as office workers in our hospital who were not exposed to noise as the control group. Blood samples were obtained from both the groups. Oxidative Stress (OS) was measured by Oxidative stress index (OSI), TOS and TAC. The DNA damage level was measured by 8-Hydroxydeoxyguanosine (8-OHdG).

RESULTS

8-OHdG (21.8 ± 12.0 vs. 14.7 ± 5.6 pg/ml, p = 0.001),TOS (14.1 ± 2.5 vs. 10.9 ± 1.5 mol H2O2 equivalent/l, p < 0.001), TAC (0.96 ± 0.19 vs. 1.54 ± 0.28 Trolox equivalent/l, p < 0.001) and OSI (1.52 ± 0.37, etc. 0.76 ± 0.35 arbitrary units, p < 0.001) were significantly higher in noise group compared to control group. Linear regression analysis showed that noise was the independent predictor of DNA damage (β = 0.310, p < 0.001).

CONCLUSION

In this study, we showed that TOS and DNA damage were significantly higher in subjects exposed to noise when compared with subjects of the control group. Noise was the only independent predictor of the DNA damage. Therefore, early detection of DNA damage and increased OS, early corrective measures may delay the development and progression of diseases such as hypertension, arrhythmias.

DNA Damage, n-3 Long-Chain PUFA Levels and Proteomic Profile in Brazilian Children and Adolescents

Fatty acids play a significant role in maintaining cellular and DNA protection and we previously found an inverse relationship between blood levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and DNA damage. The aim of this study was to explore differences in proteomic profiles, for 117 pro-inflammatory proteins, in two previously defined groups of individuals with different DNA damage and EPA and DHA levels. Healthy children and adolescents (n = 140) aged 9 to 13 years old in an urban area of Brazil were divided by k-means cluster test into two clusters of DNA damage (tail intensity) using the comet assay (cluster 1 = 5.9% ± 1.2 and cluster 2 = 13.8% ± 3.1) in our previous study. The cluster with higher DNA damage and lower levels of DHA (6.2 ± 1.6 mg/dL; 5.4 ± 1.3 mg/dL, p = 0.003) and EPA (0.6 ± 0.2 mg/dL; 0.5 ± 0.1 mg/dL, p < 0.001) presented increased expression of the proteins CDK8-CCNC, PIK3CA-PIK3R1, KYNU, and PRKCB, which are involved in pro-inflammatory pathways. Our findings support the hypothesis that low levels of n-3 long-chain PUFA may have a less protective role against DNA damage through expression of pro-inflammatory proteins, such as CDK8-CCNC, PIK3CA-PIK3R1, KYNU, and PRKCB.

DNA damage is inversely associated to blood levels of DHA and EPA fatty acids in Brazilian children and adolescents

This study aimed to investigate the association between DNA damage and blood levels of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), retinol, beta-carotene and riboflavin in Brazilian children and adolescents. Subjects (n = 140) were healthy boys and girls aged 9 to 13 years in Ribeirão Preto (SP, Brazil). Data collection included anthropometry, assessment of energy intake and blood sampling. DNA damage was evaluated by single-cell gel electrophoresis (comet assay). Principal component analysis (PCA) was used to verify associations between blood concentrations of vitamins, polyunsaturated fatty acids and DNA damage. Multiple regression analyses, k-means cluster, and analysis of covariance (ANCOVA), adjusted for confounding variables such as age, sex, energy intake, body mass index and total cholesterol (when needed), were applied to confirm the associations. PCA explained 69.4% of the inverse relationships between DNA damage and blood levels of DHA, EPA, retinol, and beta-carotene. Results were confirmed by ANCOVA and multiple regression analyses for DHA and EPA. In conclusion, omega-3-fatty acids were inversely associated with DNA damage in Brazilian children and adolescents and may be a protective factor against the development of future diseases.

Oxidative stress in vascular calcification

Vascular calcification (VC), which is closely associated with significant mortality in cardiovascular disease, chronic kidney disease (CKD), and/or diabetes mellitus, is characterized by abnormal deposits of hydroxyapatite minerals in the arterial wall. The impact of oxidative stress (OS) on the onset and progression of VC has not been well described. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, myeloperoxidase (MPO), nitric oxide synthases (NOSs), superoxide dismutase (SOD) and paraoxonases (PONs) are relevant factors that influence the production of reactive oxygen species (ROS). Furthermore, excess ROS-induced OS has emerged as a critical mediator promoting VC through several mechanisms, including phosphate balance, differentiation of vascular smooth muscle cells (VSMCs), inflammation, DNA damage, and extracellular matrix remodeling. Because OS is a significant regulator of VC, antioxidants may be considered as novel treatment options.

Effects of two different types of single exercise modes on salivary C-reactive protein concentration, oxidative stress and antioxidant capacity in post-myocardial infarction patients

Objectives

The aim of the study was to determine the effects of two different types of single cardiac rehabilitation (CR) exercise modes on the inflammation status, oxidative stress and total antioxidant capacity (TAC) of saliva.

Methods

The study involved two groups of CR patients: group A (n = 21) used a cycloergometer, and group B (n = 21) received breathing and balance exercises. C-reactive protein as an inflammatory biomarker, malondialdehyde (MDA) as a measure of the level of oxidative stress and salivary 2.2-diphenyl-1-picryl-hydrazyl (DPPH) as an index of TAC were performed twice: before the beginning of the CR exercise (pre-CR) and immediately after (post-CR).

Results

No significant changes were observed for the inflammatory response of saliva after CR exercise regardless of its type. MDA decreased (pre-CR: 39.7 ± 101.9 vs. post-CR: 16.8 ± 44.3 ng·mL⁻¹; p < 0.01) and DPPH increased (pre-CR: 25.9 ± 16.7 vs. post-CR: 32.6 ± 14.0% reduction; p < 0.05) after CR exercise in the group B, with similar but not statistically significant changes in the group A.

Discussion

Two popular exercise modes, especially breathing and balance exercises, reduce salivary oxidative stress and enhance the antioxidant potential of saliva in CR patients. The approval of saliva as a non-invasive source of information about inflammation status, oxidative stress and antioxidant capacity in cardiac patients requires further studies.

Relationships between paroxysmal atrial fibrillation, total oxidant status, and DNA damage

INTRODUCTION

Structural and electrophysiological changes play a critical role in the development of atrial fibrillation (AF). Although the pathophysiology of paroxysmal AF (PAF) has not been fully elucidated, oxidative stress (OS) and DNA damage appear to be important triggers. Thus far, no studies have investigated the relationships among total oxidant status (TOS), DNA damage, and PAF. The goal of this study was to assess TOS and DNA damage in patients with PAF.

METHODS

This cross-sectional study included 56 patients with PAF and 31 healthy controls. OS was assessed based on TOS, total antioxidant capacity (TAC), and oxidative stress index (OSI). The level of DNA damage was assessed using 8-hydroxy-2'-deoxyguanosine (8-OHdG).

RESULTS

There were no significant differences between the groups in terms of baseline characteristics. However, patients with PAF had significantly higher high-sensitivity C-reactive protein (p=0.018), TOS (p=0.001), OSI (p=0.001), and 8-OHdG (p=0.019) levels, compared with the control group. Multivariate logistic regression analysis showed that serum TOS level (odds ratio: 1.608; 95% confidence interval [CI]: 1.188-2.176, p=0.002) was the only independent predictor of PAF. TOS ≥12.2 predicted PAF with a sensitivity of 82% and specificity of 76% (AUC: 0.785, 95% CI: 0.687-0.883, p<0.001).

CONCLUSION

We found that TOS and DNA damage were significantly greater in patients with PAF than in the control group. Therefore, we propose that TOS and DNA damage can be used to detect patients at higher risk of AF.

DNA-PKcs promotes cardiac ischemia reperfusion injury through mitigating BI-1-governed mitochondrial homeostasis

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a novel inducer to promote mitochondrial apoptosis and suppress tumor growth in a variety of cells although its role in cardiovascular diseases remains obscure. This study was designed to examine the role of DNA-PKcs in cardiac ischemia reperfusion (IR) injury and mitochondrial damage. Cardiomyocyte-specific DNA-PKcs knockout (DNA-PKcs^CKO) mice were subjected to IR prior to assessment of myocardial function and mitochondrial apoptosis. Our data revealed that IR challenge, hypoxia-reoxygenation (HR) or H₂O₂-activated DNA-PKcs through post-transcriptional phosphorylation in murine hearts or cardiomyocytes. Mice deficient in DNA-PKcs in cardiomyocytes were protected against cardiomyocyte death, infarct area expansion and cardiac dysfunction. DNA-PKcs ablation countered IR- or HR-induced oxidative stress, mPTP opening, mitochondrial fission, mitophagy failure and Bax-mediated mitochondrial apoptosis, possibly through suppression of Bax inhibitor-1 (BI-1) activity. A direct association between DNA-PKcs and BI-1 was noted where DNA-PKcs had little effect on BI-1 transcription but interacted with BI-1 to promote its degradation. Loss of DNA-PKcs stabilized BI-1, thus offering resistance of mitochondria and cardiomyocytes against IR insult. Moreover, DNA-PKcs ablation-induced beneficial cardioprotection against IR injury was mitigated by concurrent knockout of BI-1. Double deletion of DNA-PKcs and BI-1 failed to exert protection against global IR injury and mitochondrial damage, confirming a permissive role of BI-1 in DNA-PKcs deletion-elicited cardioprotection against IR injury. DNA-PKcs serves as a novel causative factor for mitochondrial damage via suppression of BI-1, en route to the onset and development of cardiac IR injury.

MRE11A Polymorphisms Are Associated With Subclinical Atherosclerosis and Cardiovascular Risk Factors. A Case-Control Study of the GEA Mexican Project

DNA damage and subsequent repair pathways have been involved in the initiation and progression of atherosclerosis. Meiotic recombination 11 homolog A (MRE11A) gene polymorphisms have been associated with the presence of myocardial infarction. We analyzed five MRE11A gene polymorphisms in 386 individuals with subclinical atherosclerosis and 1093 healthy controls. Under different models, the rs13447720 (Odds ratio = 0.646, P_additive = 0.009; Odds ratio = 0.636, P_dominant = 0.012; Odds ratio = 0.664, P_{over–dominant} = 0.025; Odds ratio = 0.655, P_codominant1 = 0.021) and rs499952 (Odds ratio = 0.807, P_additive = 0.032; Odds ratio = 0.643, P_codominant2 = 0.034) polymorphisms were associated with a lower risk of subclinical atherosclerosis. On the other hand, the rs2155209 polymorphism was associated with a reduced risk of having a coronary artery calcification score ≥ 100 Agatston units. The rs13447720, rs499952, and rs2155209 polymorphisms, as well as the haplotypes that included the five studied polymorphisms were associated with some clinical and metabolic parameters in both subclinical atherosclerosis and healthy individuals. Our results suggest that the rs13447720 and rs499952 polymorphisms are associated with a decreased risk of developing subclinical atherosclerosis, whereas the rs2155209 is associated with a lower subclinical atherosclerosis severity (coronary artery calcification < 100 Agatston units). MRE11A polymorphisms and haplotypes were associated with clinical and metabolic parameters.

Plasma Total Antioxidant Capacity and Cardiometabolic Risk in Non-Obese and Clinically Healthy Young Adults

BACKGROUND:

The oxidative biomarkers play an important role in the genesis of cardiometabolic risk-related processes.

OBJECTIVE:

To investigate the total antioxidant capacity of plasma and its association with cardiometabolic risk in non-obese and clinically healthy young adults.

METHODS:

University students of the state of Sergipe, Brazil, aged between 18 and 25 years, were recruited for this study from May of 2013 and October of 2014. Anthropometric, clinical and biochemical parameters were measured and analyzed using protocols which were previously standardized and described in the literature. The measurement of plasma total antioxidant capacity was based on the ability that all the antioxidants present in the sample (plasma) have to inhibit the oxidation of the oxidizable substrate ABTS (2,2`- Azino-di-[3-ethylbenzthiazoline sulphonate]) to ABTS•+ by metmyoglobin.

RESULTS:

Approximately 25% of the sample presented more than one component of cardiometabolic risk. Low HDL-cholesterol was the most prevalent component. Compared to absence of components, the subjects with at least one component presented greater body weight and waist circumference, higher levels of diastolic blood pressure and fasting glucose, greater total cholesterol/HDL-c ratio, and lower levels of HDL-c (p < 0.05). Fasting glycemia was the only parameter which was associated with total antioxidant capacity (R2 = 0.10; β = 0.17; p = 0.001).

CONCLUSIONS:

The plasma total antioxidant capacity was not able to predict the cardiometabolic risk components due possibly to the establishment of compensatory mechanisms that become activated in physiological conditions.

FUNDAMENTOS:

Os biomarcadores oxidativos exercem um importante papel na gênese dos processos relacionados ao risco cardiometabólico.

OBJETIVO:

Investigar a capacidade antioxidante total do plasma e sua associação com risco cardiometabólico em adultos jovens, não obesos e clinicamente saudáveis.

MÉTODOS:

Estudantes universitários do estado de Sergipe, Brasil, com idade entre 18 e 25 anos, foram recrutados entre maio de 2013 e outubro de 2014. Parâmetros antropométricos, clínicos e bioquímicos foram medidos e analisados usando protocolos previamente padronizados e descritos na literatura. A medida da capacidade antioxidante total do plasma baseou-se na capacidade de todos os antioxidantes presentes na amostra (plasma) em inibir a oxidação do substrato oxidável ABTS (2,2-Azino-bis-(3-etilbenzotiazolina-6-sulfonato) a ABTS•+ pela metamioglobina.

RESULTADOS:

Aproximadamente 25% da amostra apresentaram mais de um componente do risco cardiometabólico. Valores baixos de HDL foram o componente mais prevalente. Em comparação à ausência de componentes, os indivíduos com pelo menos um componente apresentou valores mais altos de peso corporal, circunferência da cintura, pressão sanguínea diastólica, glicemia de jejum e razão colesterol total/HDL-c, e valores mais baixos de HDL-c (p < 0,05). A glicemia de jejum foi o único parâmetro que se associou com a capacidade antioxidante total (R2 = 0,10; β = 0,17; p = 0,001).

CONCLUSÕES:

A capacidade antioxidante total não foi capaz de predizer os componentes do risco cardiometabólico possivelmente devido ao estabelecimento de mecanismos compensatórios que se tornam ativados em condições fisiológicas.

DNA protective effect of ginseng and the antagonistic effect of Chinese turnip: A supplementation study

AIM

The aim of this clinical study is to provide scientific evidence for supporting traditional Chinese application and usage to the patients. For this purpose, we tested the ability if Panax ginseng extract to lower oxidative damage to nuclear DNA in human lymphocytes by comparing the effect of cooked Chinese turnip on this effect.

MATERIALS AND METHODS

Seven healthy subjects (4 males and 3 females from 37 to 60 years) participated two occasions which were at least 2 weeks apart. About 2 mL of fasting blood sample for baseline measurement was taken on arrival. They were requested to ingest the content of 5 ginseng capsules in 200 mL water. The subject remained fasting for 2 h until the second blood sample taken. In the other occasion, the experiment was repeated except a piece of cooked turnip (10 g) was taken with the ginseng extract. The two occasions could be interchanged. Comet assay was performed on two specimens on the same day for the evaluation of lymphocytic DNA damage with or without oxidative stress.

RESULTS

For the group with ginseng supplementation, there was a significant decrease in comet score for hydrogen peroxide (H₂O₂) treatment over the 2-h period while no change in DNA damage for unstressed sample. For the group with ginseng together with turnip supplementation, there was no significant difference in comet score for both H₂O₂ treatment and phosphate-buffered saline treatment. Ginseng extract could reduce DNA damage mediated by H₂O₂ effectively, but this protection effect was antagonized by the ingestion of cooked turnip at the same time.

CONCLUSION

In the current study, commercial ginseng extract was used for supplementing volunteers. Ginseng extract could protect DNA from oxidative stress in vivo while turnip diminished the protection.

The role of oxidative DNA damage and GSTM1, GSTT1, and hOGG1 gene polymorphisms in coronary artery disease risk

Objective:

Atherosclerotic coronary artery disease (CAD) appears to be a multifactorial process caused by the interaction of environmental risk factors with multiple predisposing genes. Therefore, in this study we aimed to determine the role of oxidative DNA damage and some variations in glutathione S-transferase (GSTM1 and GSTT1) and DNA repair (hOGG1) genes in CAD risk.

Methods:

A case-control study was conducted on 59 individuals who had undergone coronary angiographic evaluation. Of these, 29 were patients diagnosed with CAD (mean age =61.5±10.3) and 30 were controls examined for reasons other than suspected CAD and who had angiographically documented normal coronary arteries (mean age =60.4±11.6). Basal DNA damage as well as pyrimidine and purine base damage were evaluated in peripheral blood lymphocytes using the modified comet assay. Polymerase chain reaction-restriction length polymorphism (PCR-RFLP)-based assay was used for genotyping.

Results:

Basal DNA damage levels in patients [9.16 (3.26)] were significantly higher than those in controls [7.59 (3.23); p=0.017], and basal DNA and pyrimidine base damage levels were significantly correlated with disease severity based on Gensini scoring (r=0.352, p=0.006; r=0.318, p=0.014, respectively). However, no significant differences were observed in terms of oxidized DNA bases between patients and controls. The frequencies of studied genotypes (GSTM1, GSTT1, and hOGG1) were similar between groups.

Conclusion:

The results of this study pointed out the role of DNA damage in CAD and its severity. However, GSTM1, GSTT1, and hOGG1 gene polymorphisms seemed to have no effect on individual susceptibility for disease progression. (Anatol J Cardiol 2016; 16: 931-8)

Antioxidants and Cardiovascular Risk Factors

Cardiovascular disease (CVD), the world’s primary cause of death and disability, represents a global health problem and involves a great public financial commitment in terms of both inability to work and pharmaceutical costs. CVD is characterized by a cluster of disorders, associated with complex interactions between multiple risk factors. The early identification of high cardiovascular risk subjects is one of the main targets of primary prevention in order to reduce the adverse impact of modifiable factors, from lifestyle changes to pharmacological treatments. The cardioprotective effect of food antioxidants is well known. Indeed, a diet rich in fruits and vegetables results in an increase in serum antioxidant capacity and a decrease in oxidative stress. In contrast, studies on antioxidant supplementation, even those that are numerically significant, have revealed no clear benefit in prevention and therapy of CVD. Both short- and long-term clinical trials have failed to consistently support cardioprotective effects of supplemental antioxidant intake. The aim of this review is to evaluate the antioxidant effects on the main cardiovascular risk factors including hypertension, dyslipidemia, diabetes.

Relationship between calculated total antioxidant status and atherosclerotic coronary artery disease

Objective:

Antioxidants play a major role in the cellular protection cascade against oxidative damage. Oxidative stress has been linked to the pathogenesis of coronary atherosclerosis. Our aim was to evaluate the association between calculated serum total antioxidant status (cTAS) and the presence and severity of coronary artery disease (CAD).

Methods:

One hundred and seventy-four patients with angiographically documented significant (≥50%) luminal stenosis (n=123) or with minimal (<50%) luminal stenosis (n=51) in at least one coronary artery or major branch segment in the epicardial coronary tree were categorized as CAD⁺ group; 88 patients with no luminal stenosis were considered as the control group. The level of cTAS (mmol/L) was evaluated using the following equation: (0.63´albumin concentration)+(1.02´uric acid concentration)+(1.53´bilirubin concentration).

Results:

In univariate analyses, mean levels of cTAS, uric acid, and creatinine were significantly higher in CAD⁺ group than in controls. However, adjusted cTAS level was not found to be a CAD predictor in the total population [odds ratio (OR)=1.20; 95% confidence interval (CI): 0.81–1.76; p=0.364] or in men (OR=1.25; 95% CI: 0.73–2.12; p=0.420) and women (OR=1.20; 95% CI: 0.66–2.19; p=0.553). A weak but statistically significant correlation was found between cTAS and Gensini score (Spearman’s r=0.16, p=0.015).

Conclusion:

In patients with suspicious CAD, the level of cTAS was not found to be an independent predictor for the presence of CAD. Further studies with larger sample size are required to confirm the results.

Genetic variants in the DNA repair gene NEIL3 and the risk of myocardial infarction in a nested case-control study. The HUNT Study

BACKGROUND

Enhanced generation of reactive oxygen species and increased oxidative-induced DNA damage have been identified as possible contributors to atherosclerosis. The base excision repair (BER) pathway is the principal mechanism by which mammalian cells repair oxidative DNA damage. BER deficiency can potentially accelerate atherogenesis.

METHODS

We evaluated the association of Single Nucleotide Polymorphisms (SNPs) in genes encoding four different BER proteins (NEIL3, OGG1, APEX1 and XRCC1) with the incidence of myocardial infarction in a nested case-control study among participants of the second survey of the HUNT Study. The study population included 1624 cases and 4087 age- and sex-matched controls.

RESULTS

For the NEIL3 SNP rs12645561, the TT genotype was associated with increased risk of MI (OR 1.47, 95% CI 1.02-2.12, p uncorrected for multiple comparisons = 0.04) both in the genotypic test (compared to the CC genotype) and in the recessive genetic model (compared to the CC and CT genotypes combined). For the other two NEIL3 SNPs (rs10013040 and rs1395479) and for the SNPs of OGG1 (rs1052133), APEX1 (rs1878703) and XRCC1 (rs25489) we observed no association with risk of myocardial infarction.

CONCLUSION

We found that the NEIL3 rs12645561 SNP TT genotype was associated with increased risk of myocardial infarction. If confirmed in other studies, this association may suggest a possible role of attenuated DNA repair, and NEIL3 in particular, in atherogenesis.

DNA damage in non-communicable diseases: A clinical and epidemiological perspective

Non-communicable diseases (NCDs) are a leading cause of death and disability, representing 63% of the total death number worldwide. A characteristic phenotype of these diseases is the accelerated aging, which is the result of phenomena such as accumulated DNA damage, telomere capping loss and subcellular irreversible/nonrepaired oxidative damage. DNA damage, mostly oxidative, plays a key role in the development of most common NCDs. The present review will gather some of the most relevant knowledge concerning the presence of DNA damage in NCDs focusing on cardiovascular diseases, diabetes, chronic obstructive pulmonary disease, and neurodegenerative disorders, and discussing a selection of papers from the most informative literature. The challenge of comorbidity and the potential offered by new systems approaches for introducing these biomarkers into the clinical decision process will be discussed. Systems Medicine platforms represent the most suitable approach to personalized medicine, enabling to identify new patterns in the pathogenesis, diagnosis and prognosis of chronic diseases.

SIRT1 gene polymorphisms affect the protein expression in cardiovascular diseases

Cardiovascular disease (CVD), the leading cause of death worldwide, is related to gene-environment interactions due to epigenetic factors. SIRT1 protein and its downstream pathways are critical for both normal homeostasis and protection from CVD-induced defects. The aim of this study was to investigate the association between SIRT1 single nucleotide polymorphisms (SNPs) (rs7895833 A>G in the promoter region, rs7069102 C>G in intron 4 and rs2273773 C>T in exon 5 silent mutation) and SIRT1 and eNOS (endothelial nitric oxide synthase) protein expression as well as total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) in CVD patients as compared to controls. The frequencies of mutant genotypes and alleles for rs7069102 and rs2273773 were significantly higher in patients with CVD compared to control group. The risk for CVD was increased by 2.4 times for rs7069102 and 1.9 times for rs2273773 in carriers of mutant allele compared with carriers of wild-type allele pointing the protective role of C allele for both SNPs against CVD. For rs7895833, there was no significant difference in genotype and allele distributions between groups. SIRT1 protein, TAS, TOS and OSI levels significantly increased in patients as compared to control group. In contrast, level of eNOS protein was considerably low in the CVD patients. An increase in the SIRT1 expression in the CVD patients carrying mutant genotype for rs7069102 and heterozygote genotype for all three SNPs was observed. This is the first study reporting an association between SIRT1 gene polymorphisms and the levels of SIRT1 and eNOS expressions as well as TAS, TOS and OSI.

Relation between carotid intima media thickness and oxidative stress markers in type 1 diabetic children and adolescents

BACKGROUND

Carotid intima media thickness (CIMT) is a non invasive marker of subclinical atherosclerosis. Hyperglycemia, oxidatively modified atherogenic lipoproteins and advanced glycation end products are linked to increased oxidative stress in diabetes. We aimed to find out the relation between carotid intima media thickness in type 1 diabetic children and adolescents and plasma nitric oxide and total antioxidant capacity levels as markers of oxidative stress.

METHODS

This study included 50 children and adolescents with type 1 diabetes mellitus with mean age (9.7 ± 3.4 years) and 50 healthy age and sex matched controls. They were subjected to assessment of hemoglobin A1c, total cholesterol and triglycerides, serum total antioxidant capacity, serum nitric oxide (NO) by colorimetric method and carotid intima media thickness by B-mode ultrasound.

RESULTS

There was significant elevation in serum nitric oxide (17.07 ± 6.4 vs 12.6 ± 4.7 μmol/L; p < 0.001), CIMT (0.47 ± 0.04 vs 0.39 ± 0.02 mm; p < 0.001) and significant reduction in serum total antioxidant capacity (0.41 ± 0.29 vs 0.87 ± 0.23 mmol/L; p < 0.001) in diabetic patients compared to controls. Carotid intima media thickness was correlated positively with nitric oxide (r = 0.402, p = 0.01) and negatively with total antioxidant capacity (r = -0.341, p = 0.02). Carotid intima media thickness was also correlated positively with age, duration of diabetes but not correlated with glycemic control or lipid profile.

CONCLUSION

The significant elevation in nitric oxide and reduction in total antioxidant capacity in children and adolescents with type 1 diabetes mellitus with their correlation with carotid intima media thickness may reflect the role of oxidative stress in the development of atherosclerosis in young type 1 diabetic subjects.

Sublethal toxicity of esbiothrin relationship with total antioxidant status and in vivo genotoxicity assessment in fish (Cyprinus carpio L., 1758) using the micronucleus test and comet assay

Esbiothrin, synthetic pyrethroid with quick activity against insects, is widely used against household pests and in public health. Despite widespread use, data on ecotoxicity and genotoxic effects are extremely scarce. The aim of the present study is to evaluate the genotoxic potential of esbiothrin on a model fish species Cyprinus carpio L., 1758 (Pisces: Cyprinidae, koi) using the micronucleus test and comet assay in peripheral blood erythrocytes. Effects of two sublethal exposure concentrations on plasma total antioxidant status (TAS mmol/L), and Hct values were examined. On the basis of the 96 h LC50 data from U.S. EPA ecotox database (32 μg/L) two sublethal exposure concentrations (5 and 10 μg/L) were used together with ethyl methanesulfonate (EMS) (5 mg/L) as positive control. Five fish were used for each dose/duration group (24, 48, and 72 h) under controlled laboratory conditions. The fish showed behavioral changes at the higher dose. Plasma TAS (mmol/L) levels decreased in 24 h; an increase was observed slightly for 48 and obviously for 72 h in both exposure doses. Similarly, hematocrit (Hct) values differed between exposure duration but no significant differences in mean values were found between groups of the same exposure time. The general trend was a rise after 48 h, which decreased afterwards. Our results revealed significant increases in the frequencies of micronuclei and levels of DNA strand breaks and thus demonstrated the genotoxic potential of this pesticide on fish, a nontarget organism of the aquatic ecosystem. To our knowledge this is the first study to report observable genotoxic effects of esbiothrin on fish.

Metabolic profile and genotoxicity in obese rats exposed to cigarette smoke

OBJECTIVE

Experimental studies have shown that exposure to cigarette smoke has negative effects on lipid metabolism and oxidative stress status. Cigarette smoke exposure in nonpregnant and pregnant rats causes significant genotoxicity (DNA damage). However, no previous studies have directly evaluated the effects of obesity or the association between obesity and cigarette smoke exposure on genotoxicity. Therefore, the aim of the present investigation was to evaluate DNA damage levels, oxidative stress status and lipid profiles in obese Wistar rats exposed to cigarette smoke.

DESIGN AND METHODS

Female rats subcutaneously (s.c.) received a monosodium glutamate solution or vehicle (control) during the neonatal period to induce obesity. The rats were randomly distributed into three experimental groups: control, obese exposed to filtered air, and obese exposed to tobacco cigarette smoke. After a 2-month exposure period, the rats were anesthetized and killed to obtain blood samples for genotoxicity, lipid profile, and oxidative stress status analyses.

RESULTS

The obese rats exposed to tobacco cigarette smoke presented higher DNA damage, triglycerides, total cholesterol, free fatty acids, VLDL-c, HDL-c, and LDL-c levels compared to control and obese rats exposed to filtered air. Both obese groups showed reduced SOD activity. These results showed that cigarette smoke enhanced the effects of obesity.

CONCLUSION

In conclusion, the association between obesity and cigarette smoke exposure exacerbated the genotoxicity, negatively impacted the biochemical profile and antioxidant defenses and caused early glucose intolerance. Thus, the changes caused by cigarette smoke exposure can trigger the earlier onset of metabolic disorders associated with obesity, such as diabetes and metabolic syndrome.

Plasma and dietary antioxidant status as cardiovascular disease risk factors: a review of human studies

Extensive evidence has demonstrated that many antioxidants such as vitamin C, vitamin E, carotenoids and polyphenols have protective effects in preventing cardiovascular disease (CVD), a chronic disease that is mediated by oxidative stress and inflammation. This review focuses on evidence from prospective cohort studies and clinical trials in regard to the associations between plasma/dietary antioxidants and cardiovascular events. Long-term, large-scale, population-based cohort studies have found that higher levels of serum albumin, bilirubin, glutathione, vitamin E, vitamin C, and carotenoids were associated with a lower risk of CVD. Evidence from the cohort studies in regard to dietary antioxidants also supported the protective effects of dietary vitamin E, vitamin C, carotenoids, and polyphenols on CVD risk. However, results from large randomized controlled trials did not support long-term use of single antioxidant supplements for CVD prevention due to their null or even adverse effects on major cardiovascular events or cancer. Diet quality indexes that consider overall diet quality rather than single nutrients have been drawing increasing attention. Cohort studies and intervention studies that focused on diet patterns such as high total antioxidant capacity have documented protective effects on CVD risk. This review provides a perspective for future studies that investigate antioxidant intake and risk of CVD.

Association between genetic variants of DNA repair genes and coronary artery disease

Polymorphisms in DNA repair genes may be associated with differences in the repair efficiency of DNA damage and may influence an individual's risk of atherosclerosis. Genetic research on coronary artery disease (CAD) has traditionally focused on investigation aimed at identifying disease-susceptibility genes. The aim of this study was to investigate the relationship between AP-endonuclease-1 (Asp148Glu), XRCC1 (Arg399Gln), XRCC3 (Thr241Met), XPD (Lys751Gln), XPG (Asp1104His), and hOGG1 (Ser326Cys), gene polymorphisms and the risk of developing CAD in a Turkish population. The study population consisted of 197 patients with acute coronary syndrome (ACS) with chronic CAD and 135 healthy subjects' age and sex matched. Gene polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism method. We demonstrated for the first time, a positive association of XRCC3 and hOGG1 DNA repair gene variants with CAD risk. XRCC3 Thr/Thr genotype and Thr allele frequencies were significantly increased in ACS and chronic CAD patients compared with the control group (p<0.05). It was also observed that there is a protective role of XRCC3 Met alleles against both ACS and chronic CAD (p<0.05). hOGG1 Cys alleles were found significantly higher in ACS patients than in the control group and carriers of the Cys allele had a 1.7-fold increased risk for ACS. In addition, we confirmed the association of XRCC3 Thr241Met and hOGG1 Ser326Cys gene variants with CAD by haplotype analysis. We found that CAD risk is associated with XRCC3 Thr: hOGG1 Cys haplotype, whereas XRCC3 Met: hOGG1 Ser haplotype was found to be protective against the disease. The preliminary results suggested that XRCC3 and hOGG1 genetic variants may be risk factors by affecting the enzyme's function that may lead to development of CAD.

Changes in the level of spontaneous DNA damage in whole blood leukocytes during storage

We evaluated structural damage to DNA (%TDNA) in blood leukocytes from healthy donors of different age at different periods (0-6 days) of blood storage at 4-8°C. It was found that the basal level of DNA damage increased and intracellular antioxidant level decreased during storage. Mean %TDNA was 6.8±3.3% in the fresh blood and 19.2±8.1% after 5-day storage. The experiments with exposure to reactive oxygen species induced by irradiation suggest that depletion of low-molecular-weight endogenous antioxidants occurs as soon as after 5-h storage. Our results suggest that storage time should be taken into account when assessing the basal and induced levels of leukocyte DNA damage by the comet assay.

Gender-specific relationships between plasma oxidized low-density lipoprotein cholesterol, total antioxidant capacity, and central adiposity indicators

BACKGROUND

Oxidative stress has a pivotal role in the onset of obesity-related chronic diseases. This study assessed potential gender differences in the associations of adiposity (total vs. central) with oxidative stress markers in healthy young adults.

METHODS

This cross-sectional study enrolled 272 subjects (97 males, 175 females; 22 ± 3 years, body mass index 22.0 ± 2.8 kg/m(2)). Body composition, cardiometabolic and lifestyle features, oxidized low-density lipoprotein cholesterol (ox-LDL) concentrations, plasma total antioxidant capacity (TAC), and glutathione peroxidase (GPx) activity in erythrocytes were determined by validated procedures.

RESULTS

Compared to women, men had statistically higher concentrations of ox-LDL (61.7 vs. 53.5 U/l, p = 0.022). In analyses with the whole sample, those individuals included in the highest tertile of central adiposity indicators (waist circumference, WC, or waist-to-hip ratio, WHR) presented higher ox-LDL and lower TAC values (p < 0.01), while no statistical differences were found across tertiles of total body fat. WHR values were more strongly associated with ox-LDL and TAC concentrations, compared to other adiposity indicators, with higher slopes for women. Sex differences in ox-LDL concentrations were abolished (p > 0.05) after individual pairing of men and women for WC (53.8 vs. 61.6 U/l, p = 0.225) or WHR (56.1 vs. 56.3 U/l, p = 0.471). No differences were found in GPx values concerning gender or adiposity indicators.

CONCLUSIONS

Plasma ox-LDL and TAC values were more strongly influenced by central adiposity indicators (WHR and WC) in women than in men, suggesting that the change of the gynoid to android pattern phenotype among young women could lead to a steeper unfavourable redox status compared to men.

Vegetables and PUFA-rich plant oil reduce DNA strand breaks in individuals with type 2 diabetes

SCOPE

Type 2 diabetes is a multifactorial disease associated with increased oxidative stress, which may lead to increased DNA damage. The aim of this study was to investigate the effect of a healthy diet on DNA oxidation in diabetics and nondiabetics.

METHODS AND RESULTS

Seventy-six diabetic and 21 nondiabetic individuals participated in this study. All subjects received information about the benefits of a healthy diet, while subjects randomly assigned to the intervention group received additionally 300 g of vegetables and 25 mL PUFA-rich plant oil per day. DNA damage in mononuclear cells (Comet Assay), urinary excretion of 8-oxo-7-hydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and glycated hemoglobin (HbA1c) were measured at baseline, after 4, 8 (end of intervention), and 16 weeks. The intervention with vegetables and PUFA-rich oil led to a significant increase in plasma antioxidant concentrations. Diabetic individuals of the intervention group showed a significant reduction in HbA1c and DNA strand breaks. Levels of HbA1c were also improved in diabetics of the information group, but oxidative damage to DNA was not altered. Urinary 8-oxodG and 8-oxoGuo excretion remained unchanged in both groups.

CONCLUSIONS

This study provides evidence that a healthy diet rich in antioxidants reduces levels of DNA strand breaks in diabetic individuals.

Evaluation of oxidative stress markers in pathogenesis of diabetic neuropathy

Experimental evidences suggest that hyperglycaemia-induced overproduction of reactive oxygen species and subsequent damage to proteins, lipids and DNA may play a key role in the development of distal symmetric polyneuropathy (DSPN)—the most common complication of diabetes mellitus. The study population consisted of 51 individuals aged 52–82 years classified into 3 groups: 16 patients diagnosed with type 2 diabetes mellitus (T2DM) with DSPN, 16 T2DM patients without DSPN and 19 control subjects without diabetes and neuropathy. The study was conducted to determine the activity of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX) and total antioxidant status (TAS) in the examined groups. An alkaline comet assay was used to determine the extent of DNA damage of oxidized purines as glicosylo-formamidoglicosylase (Fpg) sites, and oxidized pyrimidines as endonuclease III (Nth) sites. A significant decrease of SOD (P < 0.05), GPX (P < 0.05) and nonsignificant decrease of CAT (P > 0.05), and TAS status (P > 0.05) were seen in T2DM patients with neuropathy compared to T2DM patients as well as controls. T2DM patients with or without neuropathy revealed significantly lower (P < 0.05) plasma concentration of nitrous oxide compared to the control subjects. Endogenous level of oxidative DNA damage in T2DM patients with DSPN was significantly higher compared both to the controls and T2DM patients without DSPN (P < 0.001). Moreover, lymphocytes isolated from T2DM patients with DSPN were more susceptible to oxidative DNA lesions induced by hydrogen peroxide than from T2DM patients without DSPN (P < 0.001). Our results confirm hypothesis that oxidative stress may play a substantial role in the development and progression of diabetic distal symmetric polyneuropathy.

Correlations between oxidative DNA damage, oxidative stress and coenzyme Q10 in patients with coronary artery disease

The correlation of coronary artery disease (CAD) with pro-oxidant/antioxidant balance and oxidative DNA damage was investigated. Seventy-seven patients with CAD and 44 healthy individuals as control were included in this study. The comparative ratios of ubiquinol-10/ubiquinone-10, 8-hydroxy-2(')-deoxyguanosine/deoxyguanosine and the level of MDA measured by HPLC and the activities of GPX and SOD by colorimetric approach in blood samples obtained from patients with CAD were unraveled.8-OHdG/dG ratios, serum MDA level and GPX activity were found significantly elevated level in serum of CAD patients compared to control group. The SOD activity was observed in stable levels in CAD patients. Ubiquinol-10/ubiquinone-10 ratio was significantly lower in patients with CAD than the controls. The positive correlation was observed between 8-OHdG/dG ratios in both MDA levels and GPX activity, while the significant negative correlation was seemed between the ratio of 8-OHdG/dG and ubiquinol-10/ubiquinone-10 as well as MDA levels and ubiquinol-10/ubiquinone-10 ratio. We conclude that, both the disruption of pro-oxidant/antioxidant balance and oxidative stress in DNA may play an important role in the pathogenesis of coronary artery disease.

Alkaline, Endo III and FPG modified comet assay as biomarkers for the detection of oxidative DNA damage in rats with experimentally induced diabetes

Increased production of reactive oxygen species under diabetic condition underlines the higher oxidatively damaged DNA in different tissues. However, it is practically difficult to assess the oxidatively damaged DNA in different internal organs. Therefore, the present study was aimed to evaluate the extent of oxidative stress-induced DNA damage in different organs with the progression of diabetes. Diabetic and control Sprague Dawley rats were sacrificed in time-dependent manner and the lung, liver, heart, aorta, kidney, pancreas and peripheral blood lymphocytes (PBL) were analyzed for both alkaline and modified comet assay with endonuclease-III (Endo III) and formamidopyrimidine-DNA glycosylase (FPG) (hereafter called modified comet assay) for the detection of oxidative DNA damage. The statistically significant increase in olive tail moment (OTM) was found in all the tested tissues. The extent of DNA damage was increased with the progression of diabetes as revealed by the parameter of OTM in alkaline and modified comet assay. Further, the positive correlations were observed between OTM of the lung, liver, heart, aorta, kidney and pancreas with PBL of diabetic rat in the alkaline and modified comet assay. Moreover, significant increase in the 8-oxodG positive nuclei in the lung, liver, heart, aorta, kidney and pancreas was observed in 4th and 8th week diabetic rat as compared to control. Results of the present study clearly indicated the suitability of alkaline and modified comet assay for the detection of multi-organ oxidative DNA damage in streptozotocin (STZ)-induced diabetic rat and showed that damaged DNA of PBL can be used as a suitable biomarker to assess the internal organs response to DNA damage in diabetes.

Vitamin C and fibre consumption from fruits and vegetables improves oxidative stress markers in healthy young adults

The aim of the present cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) consumption and some oxidative stress markers in young adults, with particular emphasis on fibre and vitamin C intake. The study enrolled 246 healthy subjects (eighty-eight men and 158 women), with a mean age of 22 (sd 3) years and a mean BMI of 21·9 (sd 2·8) kg/m2. Dietary intake, anthropometry, blood pressure, lifestyle features and blood biochemical data were assessed with validated procedures. Those subjects in the highest tertile (T) of FV consumption ( ≥ 705 g/d) had statistically lower oxidised LDL (ox-LDL) concentrations as well as higher plasma total antioxidant capacity (TAC) and glutathione peroxidase (GPx) activity (P for trend <0·05), after adjusting for sex, age, energy intake, physical activity, smoking, BMI, vitamin supplement use and other confounding factors. Moreover, plasma ox-LDL concentrations showed a decreasing trend and TAC an increasing trend across tertiles of fibre (T3: ≥14 g/d) and vitamin C (T3: ≥150 mg/d) from FV intake, while GPx activity was positively associated with vitamin C intake (P for trend < 0·05). In conclusion, greater FV consumption was independently associated with reduced ox-LDL as well as increased TAC and GPx activity in healthy young adults, with dietary fibre and vitamin C from FV clearly being implicated in this beneficial relationship.

Superoxide anion and hydrogen peroxide-induced signaling and damage in angiotensin II and aldosterone action

The formation of reactive oxygen species (ROS) can be induced by xenobiotic substances, such as redox cycling molecules, but also by endogenous substances such as hormones and cytokines. Recent research shows the importance of ROS in cellular signaling. Here, the signaling pathways of the two blood pressure-regulating hormones angiotensin II and aldosterone are presented, focusing on both their physiological effects and the change of signaling owing to the action of increased concentrations or prolonged exposure. When present in high concentrations, both angiotensin II and aldosterone, as various other endogenous substances, activate NADPH oxidase, which produces superoxide. In this review the generation of superoxide anions and hydrogen peroxide in cells stimulated with angiotensin II or aldosterone, as well as the subsequently induced signaling processes and DNA damage is discussed.

Dietary reference values of individual micronutrients and nutriomes for genome damage prevention: current status and a road map to the future

Damage to the genome is recognized as a fundamental cause of developmental and degenerative diseases. Several micronutrients play an important role in protecting against DNA damage events generated through endogenous and exogenous factors by acting as cofactors or substrates for enzymes that detoxify genotoxins as well as enzymes involved in DNA repair, methylation, and synthesis. In addition, it is evident that either micronutrient deficiency or micronutrient excess can modify genome stability and that these effects may also depend on nutrient-nutrient and nutrient-gene interaction, which is affected by genotype. These observations have led to the emerging science of genome health nutrigenomics, which is based on the principle that DNA damage is a fundamental cause of disease that can be diagnosed and nutritionally prevented on an individual, genetic subgroup, or population basis. In this article, the following topics are discussed: 1) biomarkers used to study genome damage in humans and their validation, 2) evidence for the association of genome damage with developmental and degenerative disease, 3) current knowledge of micronutrients required for the maintenance of genome stability in humans, 4) the effect of nutrient-nutrient and nutrient-genotype interaction on DNA damage, and 5) strategies to determine dietary reference values of single micronutrients and micronutrient combinations (nutriomes) on the basis of DNA damage prevention. This article also identifies important knowledge gaps and future research directions required to shed light on these issues. The ultimate goal is to match the nutriome to the genome to optimize genome maintenance and to prevent pathologic amounts of DNA damage.