Putative susceptibility markers of coronary artery disease: association between VDR genotype, smoking, and aromatic DNA adduct levels in human right atrial tissue

Four common vitamin D receptor polymorphisms and coronary artery disease susceptibility: A trial sequential analysis

Background

Studies on the susceptibility of vitamin D receptor (VDR) polymorphisms to coronary artery disease (CAD) reached controversial results. We performed this study for a more accurate evaluation between the VDR polymorphisms and CAD susceptibility.

Methods

PubMed, Embase, CNKI, Wan Fang, and VIP databases were searched. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to evaluate the associations. Trial sequential analysis (TSA) was introduced to estimate the positive associations. The potential functions of the VDR polymorphisms were analyzed based on the SNPinfo and ENSEMBL databases.

Results

Thirteen studies were finally included. In the overall analysis, increased CAD risks were observed in the VDR rs1544410 polymorphism and verified by the TSA; for the rs2228570 and rs731236 polymorphisms, significant associations with high heterogeneity were detected; decreased risk was remarkably observed for the rs7975232 polymorphism. In the subgroup analysis, wide associations with reduced heterogeneity were observed in the rs2228570, rs1544410, and rs731236 polymorphisms. The RNAfold analysis indicated the mutant G allele of the rs1544410 polymorphism was easier to disperse from the DNA double helix structure and may have a potential crucial role in the VDR transcription process.

Conclusions

Our analysis supports the role of the rs1544410 polymorphism in the VDR gene as a risk factor for CAD. The VDR rs2228570 and rs731236 polymorphisms were associated with increased CAD risks in the White population. Restrict decreased CAD risk was firstly discovered in the rs7975232 polymorphism.

Limitations

Firstly, the language was restricted to English and Chinese, which will cause the limited number of studies included; secondly, other unknown polymorphisms in VDR polymorphisms could also be associated the CAD susceptibility, and more case-control studies with comprehensive clinical outcomes and GWAS studies were required; thirdly, the rs1544410, rs7975232 and rs731236 polymorphism are in strong LD, haploid factors with CAD risk need to be considered; fourthly, the mechanisms of the VDR polymorphism on the VDR gene or RNA or protein were not discussed enough, further mechanistic studies are required; at last, genetic factor was the one side for CAD susceptibility, the interaction between environmental risk factors should be considered.

The Role of Estrogens and Vitamin D in Cardiomyocyte Protection: A Female Perspective

Women experience a dramatical raise in cardiovascular events after menopause. The decline in estrogens is pointed to as the major responsible trigger for the increased risk of cardiovascular disease (CVD). Indeed, the menopausal transition associates with heart macro-remodeling, which results from a fine-tuned cell micro-remodeling. The remodeling of cardiomyocytes is a biomolecular response to several physiologic and pathologic stimuli, allowing healthy adaptation in normal conditions or maladaptation in an unfavorable environment, ending in organ architecture disarray. Estrogens largely impinge on cardiomyocyte remodeling, but they cannot fully explain the sex-dimorphism of CVD risk. Albeit cell remodeling and adaptation are under multifactorial regulation, vitamin D emerges to exert significant protective effects, controlling some intracellular paths, often shared with estrogen signaling. In post-menopause, the unfavorable association of hypoestrogenism-D hypovitaminosis may converge towards maladaptive remodeling and contribute to increased CVD risk. The aim of this review is to overview the role of estrogens and vitamin D in female cardiac health, speculating on their potential synergistic effect in cardiomyocyte remodeling, an issue that is not yet fully explored. Further learning the crosstalk between these two steroids in the biomolecular orchestration of cardiac cell fate during adaptation may help the translational approach to future cardioprotective strategies for women health.

Arterial calcification, atherosclerosis and osteoporosis: only clinical associations or a genetic platform?

The review is devoted to the comorbidity of two multifactorial diseases  — atherosclerosis and osteoporosis. Numerous epidemiological, experimental and clinical studies have confirmed the relationship between these diseases based on common risk factors and pathogenetic mechanisms. At the same time, to assess the associations between osteoporosis and atherosclerosis-related cardiovascular diseases, the following surrogate markers are used: vascular calcification, vascular stiffness, bone mineral density. It is known that atherosclerosis and osteoporosis depend on the human genotype, and they are caused by the interaction between the environment and genes. The modifiable risk factors for these diseases are largely similar, and the common features of atherosclerosis and osteoporosis pathogenesis make it possible to formulate the concept of a unified genetic basis of their development. Advances in molecular technology have made it possible to conduct a genome-wide association study (GWAS) and successfully identify genetic markers associated with both atherosclerosis and osteoporosis. The review aim was to describe the genes associated with developing atherosclerosis, arterial calcification and osteoporosis, as well as to provide information on the current understanding of the general genetic basis for plaque formation, vascular calcium deposition, and a decrease in bone mass. The analysis of publications from the PubMed, Medline, Web of Science and Cochrane Library databases since 2000 have been carried out. The article describes the genetic markers associated with atherosclerosis and osteoporosis, as well as considers the achievements in studying genetics of osteoporosis and atherosclerosis-related cardiovascular diseases. In addition, modern approaches and directions for further research of these diseases was established. The review can be useful for medical practitioners to clarify various genetic associations and mechanisms that lead to this comorbidity.

Conundrum of vitamin D on glucose and fuel homeostasis

As an endocrine hormone, vitamin D plays an important role in bone health and calcium homeostasis. Over the past two decades, the non-calcemic effects of vitamin D were extensively examined. Although the effect of vitamin D on beta cell function were known for some time, the effect of vitamin D on glucose and fuel homeostasis has attracted new interest among researchers. Yet, to date, studies remain inconclusive and controversial, in part, due to a lack of understanding of the threshold effects of vitamin D. In this review, a critical examination of interventional trials of vitamin D in prevention of diabetes is provided. Like use of vitamin D for bone loss, the benefits of vitamin D supplementation in diabetes prevention were observed in vitamin D-deficient subjects with serum 25-hydroxyvitamin D < 50 nmol/L (20 ng/mL). The beneficial effect from vitamin D supplementation was not apparent in subjects with serum 25-hydroxyvitamin D > 75 nmol/L (30 ng/mL). Furthermore, no benefit was noted in subjects that achieved serum 25-hydroxyvitamin D > 100 nmol/L (40 ng/mL). Further studies are required to confirm these observations.

Vitamin D Receptor Gene Polymorphism and Vitamin D Status in Population of Patients with Cardiovascular Disease-A Preliminary Study

The association between vitamin D receptor (VDR) polymorphism and the risk of cardiovascular diseases (CVD) remains unclear. This study aimed to assess a relationship between the VDR genotypes, plasma concentrations of vitamin D metabolites, and the occurrence of cardiovascular and metabolic disorders. Fifty-eight patients treated for various cardiological afflictions were included. Identification of VDR polymorphisms: ApaI, TaqI, BsmI, and FokI were carried out using the PCR-RFLP method. Plasma concentrations of 25-hydroxyvitamin-D2, 25-hydroxyvitamin-D3, and 3-epi-25-hydroxyvitamin D3 were assessed by the UPLC-MS/MS method. Lower incidence of BsmI AA genotype in the studied patients was observed compared with healthy controls, but the difference was insignificant. Among patients with the TT genotype, frequency of hypertension was higher than among carriers of other ApaI genotypes (p < 0.01). In addition, carriers of the TT ApaI, TC TaqI, and GA BsmI genotypes had an increased risk of obesity, while the presence of the FokI TT genotype was associated with a higher incidence of heart failure and hypertension. In conclusion, the BsmI AA genotype can be protective against CVD, but this observation needs study on a larger group of patients. Particular VDR genotypes were associated with 25-hydroxyvitamin-D levels, and the mechanism of this association should be further investigated.

Association of GSTP1 Ile105Val polymorphism with the risk of coronary heart disease: An updated meta-analysis

Background

Numerous case-control studies have investigated the association between GSTP1 Ile105Val polymorphism and CHD risk, but the results from published studies were inconclusive. The present meta-analysis was performed to derive a more precise estimation.

Methods

PubMed, EMBASE, and Web of Science database searches were conducted to retrieve relevant articles.

Results

Ultimately, 5,451 CHD cases and 5,561 controls from 15 studies were included. Pooled analysis did not yield any statistically significant association between GSTP1 Ile105Val polymorphism and CHD risk for the overall population (Val vs. Ile: OR, 1.05; 95% CI, 0.93 to 1.18; Val/Val vs. Ile/Ile: OR, 1.09; 95% CI, 0.83 to 1.42; Val/Ile vs. Ile/Ile: OR, 1.09; 95% CI, 0.93 to 1.28; Val/Val vs. Val/Ile+Ile/Ile: OR, 1.04; 95% CI, 0.83 to 1.30; Val/Val+Val/Ile vs. Ile/Ile: OR, 1.14; 95% CI, 0.97 to 1.33). Subgroup analyses and sensitivity analyses indicated that GSTP1 Ile105Val polymorphism was still not associated with an increased risk of CHD. After excluding studies detected by Galbraith plots as major sources of heterogeneity, these relationships were still not significant.

Conclusions

The overall results did not reveal a major role of the GSTP1 Ile105Val polymorphism in modulating CHD risk. Well-designed studies with large sample sizes are needed to validate our findings and explore the possible gene-gene or gene-environment interactions.

Study of vitamin D receptor gene polymorphisms in a cohort of myocardial infarction patients with coronary artery disease

Background

Vitamin D deficiency is associated with cardiovascular diseases, including coronary artery diseases (CAD). As vitamin D manifests its biological function through its vitamin D receptor (VDR), VDR gene polymorphisms potentially affect VDR functionality and vitamin D activity. Therefore, the objective of this study was to analyze three well-studied VDR gene polymorphisms—Fok1 (rs2228570), BsmI (rs1544410) and Taq1 (rs731236)—in a cohort of CAD patients after acute myocardial infarction.

Methods

In the presented cross-sectional study, 155 participants with CAD after acute myocardial infarction and 104 participants in a control group without CAD were enrolled. The participants in both groups were Caucasians of European origin. The genotyping of VDR polymorphisms rs2228570, rs1544410 and rs731236 was assessed by RT-PCR.

Results

The results show an association between the T/T genotype of the BsmI (rs1544410) and the G/G genotype of the Taq1 (rs731236) VDR polymorphism and CAD patients after acute myocardial infarction. There was no association between the Fok1 (rs2228570) VDR polymorphism and CAD patients after acute myocardial infarction.

Conclusion

The presented results suggest a potential association of the BsmI (rs1544410) and Taq1 (rs731236) VDR polymorphisms with CAD patients after myocardial infarction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01959-x.

Association of Glutathione S-Transferase theta 1 and mu 1 Genes Polymorphisms with the Susceptibility of Myocardial Infarction in Bangladesh

Background

Myocardial infarction is one of the leading causes of morbidity and mortality worldwide. Oxidative stress plays a vital role in the pathogenesis of atherosclerosis leading to myocardial infarction and Glutathione S-transferases (GSTs) act as detoxifying enzymes to reduce oxidative stress. The aim of the present study was to investigate the associations of the GST (T1 & M1) gene polymorphism with the susceptibility of myocardial infarction in the Bangladeshi population.

Methods

A case-control study on 100 cardiac patients with MI and 150 control subjects was conducted. The genotyping of GST (T1 & M1) gene was done using conventional Polymerase Chain Reaction.

Results

The percentage of GSTM1 genotypes was significantly (p< 0.01) lower in patients compared to control subjects while the GSTT1 genotypes were not significantly different between the study subjects. The individual with GSTM1 null allele was at 2.5-fold increased risk {odds ratio (OR)= 2.5; 95 % confidence interval (95 % CI)= 1.4 to 4.3; p< 0.01} of experiencing MI while individual with either GSTM1 or GSTT1 genotypes was at lower risk. In the case of GST M1 and GST T1 combined genotype, patients having both null genotypes for GST M1 and GST T1 gene showed significantly (p< 0.01) higher risk of experiencing MI when compared to control subjects (OR= 3.5; 95% CI= 1.7-7.2; p< 0.001).

Conclusion

Thus our recent study suggested that GSTM1 alone and GSTM1 and T1 in combination augments the risk of MI in Bangladeshi population.

Genetics of Arterial-Wall-Specific Mechanisms in Atherosclerosis: Focus on Mitochondrial Mutations

PURPOSE OF REVIEW

Mutations in both nuclear and mitochondrial genes are associated with the development of atherosclerotic lesions in arteries and may provide a partial explanation to the focal nature of lesion distribution in the arterial wall. This review is aimed to discuss the genetic aspects of atherogenesis with a special focus on possible pro-atherogenic variants (mutations) of the nuclear and mitochondrial genomes that may be implicated in atherosclerosis development and progression.

RECENT FINDINGS

Mutations in the nuclear genes generally do not cause a phenotype restricted to a specific vascular wall cell and manifest themselves mostly at the organism level. Such mutations can act as important contributors to changes in lipid metabolism and modulate other risk factors of atherosclerosis. By contrast, mitochondrial DNA (mtDNA) mutations occurring locally in the arterial wall cells or in circulating immune cells may play a site-specific role in atherogenesis. The mosaic distribution of heteroplasmic mtDNA mutations in the arterial wall tissue may explain, at least to some extent, the locality and focality of atherosclerotic lesions distribution. The genetic mechanisms of atherogenesis include alterations of both nuclear and mitochondrial genomes. Altered lipid metabolism and inflammatory response of resident arterial wall and circulating immune cells may be related to mtDNA damage and defective mitophagy, which hinders clearance of dysfunctional mitochondria. Mutations of mtDNA can have mosaic distribution and locally affect functionality of endothelial and subendothelial intimal cells in the arterial wall contributing to atherosclerotic lesion development.

Effects of glutathione S-transferase M1 and T1 deletions on Parkinson's disease risk among a North African population

PURPOSE

In this study, the effects of glutathione S-transferase polymorphisms Mu1 (GSTM1) and glutathione S-transferase polymorphisms Theta1 (GSTT1) on Parkinson's disease (PD) risk factor were evaluated in a Tunisian population.

METHODS

These polymorphisms were analyzed in 229 healthy Tunisian subjects and 64 Tunisian patients with PD, using a polymerase chain reaction (PCR). Statistical analysis was performed using SPSS 18.0. The relative associations between the GST genotypes and PD were assessed by calculating the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The study results demonstrated that the individuals with GSTM1 [OR=3.93, 95% CI: 1.98-7.92, P=10^-6] and GSTT1 [OR=5.45, 95% CI: 2.90-10.30, p=10^-6] were statistically associated with the risk of PD. A significant association was also found between the individuals with both GSTM1/T1 null genotypes and PD risk [OR=22.10, 95% CI: 6.99-73.75, P=10^-6].

CONCLUSION

These genotyping findings suggest that the absence of both GSTM1 and GSTT1 activity could be a contributory factor for the development of PD.

The role of vitamin D in the pathogenesis and treatment of diabetes mellitus: a narrative review

Diabetes mellitus, a metabolic disorder associated with chronic complications, is traditionally classified into two main subtypes. Type 1 diabetes mellitus (T1DM) results from gradual pancreatic islet β cell autoimmune destruction, extending over months or years. Type 2 diabetes mellitus (T2DM) is a heterogeneous disorder, with both insulin resistance and impairment in insulin secretion contributing to its pathogenesis. Vitamin D is a fat-soluble vitamin with an established role in calcium metabolism. Recently, several studies have provided evidence suggesting a role for it in various non-skeletal metabolic conditions, including both types of diabetes mellitus. Preclinical studies of vitamin D action on insulin secretion, insulin action, inflammatory processes, and immune regulation, along with evidence of an increase of hypovitaminosis D worldwide, have prompted several epidemiological, observational, and supplementation clinical studies investigating a potential biological interaction between hypovitaminosis D and diabetes. This narrative review aims to summarize current knowledge on the effect of vitamin D on T1DM and T2DM pathogenesis, prevention, and treatment, as well as on micro- and macrovascular complications of the disease. Furthermore, on the basis of current existing evidence, we aim to highlight areas for potential future research.

Polymorphisms and haplotypes in VDR gene are associated with female idiopathic infertility

Unexplained infertility refers to the absence of a definable cause of reproductive failure. Vitamin D receptor (VDR) acts as a transcription factor and regulates a number of vitamin D-responsive genes, including those involved in the immune system. Recent finding that VDR is expressed in reproductive tissues suggests a possible importance of vitamin D in pregnancy. We conducted a case-control study to examine the association of polymorphisms in VDR gene with reproductive success. DNA from 117 female patients with unexplained infertility and 130 fertile controls was isolated from peripheral blood and VDR genotypes (FokI, BsmI, ApaI and TaqI) were detected by PCR-RFLP. Haplotypes were determined using Haploview software. Our results show significant association of FokI and BsmI polymorphisms with infertility (p < 0.05). The haplotype analysis confirmed strong linkage disequilibrium between closely positioned BsmI, ApaI and TaqI polymorphisms. Two haplotypes were associated with infertility: (i) haplotype bAT was increasing the risk for secondary infertility; while (ii) haplotype BAT had a protective role against primary infertility (p < 0.05). By changing the expression and the activity of VDR gene, which leads to the change in expression of vitamin D-responsive genes, these polymorphisms and haplotypes could possibly have an effect on immune system in the female reproductive tract.

Role of serum MMP-9 levels and vitamin D receptor polymorphisms in the susceptibility to coronary artery disease: An association study in Iranian population

BACKGROUND

Data concerning the association of serum levels of vitamin D and metalloproteinases and vitamin D receptor gene polymorphism with coronary artery disease (CAD) is not fully demonstrated. The present study aimed to evaluate the association of vitamin D receptor gene polymorphism, serum levels of 25(OH) vitamin D and metalloproteinase-9 (MMP-9) with CAD.

METHODS

104 patients with CAD and 69 Non-CAD subjects were included in current study. Vitamin D receptor genotypes were determined by PCR-RFLP method. The 25(OH) vitamin D and MMP-9 were determined by ELISA assay.

RESULTS

There was a significant reduction of vitamin D in CAD patients (P=0.001). The metalloproteinase 9 levels of CAD patient was increased significantly compared with controls (P=0.001). A significant reverse correlation also was found between MMP-9 concentration and 25(OH) vitamin D levels of patients (r=-0.28, P<0.001). In addition, we identified that VDR gene FokI polymorphism was significantly associated with CAD. Furthermore, MMP-9 levels of CAD patients with ff genotype of FokI polymorphism was higher significantly than patients with FF and Ff genotypes. It has been also found that MMP-9 levels of CAD patients with ff genotype of FokI polymorphism was higher significantly than patients with FF and Ff genotypes.

CONCLUSION

Our results indicated that 25(OH) vitamin D, MMP-9 levels and VDR gene FokI polymorphisms play a critical role in the development and progression of CAD and may contribute to susceptibility to CAD in Iranian populations.

Vitamin D and diabetes mellitus: Causal or casual association?

The incidence of both type 2 and type 1 diabetes mellitus has been increasing worldwide. Vitamin D deficiency, or the awareness of its prevalence, has also been increasing. Vitamin D may have a role in the pathogenic mechanisms predisposing to type 2 diabetes by modulating insulin resistance and/or pancreatic β-cell function. Vitamin D status or elements involved in its activation or transport may also be involved in the development of type 1 diabetes mellitus through immunomodulatory role . Based on these observations a potential association between vitamin D and diabetes has been hypothesized. In this review we discuss up to date evidence linking vitamin D with the development of diabetes. Moreover, the role of vitamin D supplementation in the prevention of both types of diabetes is analysed together with its role in improving glycemic control in diabetic patients. We also address the potential role of vitamin D deficiency in the development of macro- and microvascular complications in diabetes. Finally, we provide recommendation for Vitamin D therapy in diabetes in view of current evidence and highlight areas for potential future research in this area.

Pandora's Box: mitochondrial defects in ischaemic heart disease and stroke

Ischaemic heart disease and stroke are vascular events with serious health consequences worldwide. Recent genetic and epigenetic techniques have revealed many genetic determinants of these vascular events and simplified the approaches to research focused on ischaemic heart disease and stroke. The pathogenetic mechanisms of ischaemic heart disease and stroke are complex, with mitochondrial involvement (partially or entirely) recently gaining substantial support. Not only can mitochondrial reactive oxygen species give rise to ischaemic heart disease and stroke by production of oxidised low-density lipoprotein and induction of apoptosis, but the impact on pericytes contributes directly to the pathogenesis. Over the past two decades, publications implicate the causative role of nuclear genes in the development of ischaemic heart disease and stroke, in contrast to the potential role of mitochondrial DNA (mtDNA) in the pathophysiology of the disorders, which is much less understood, although recent studies do demonstrate that the involvement of mitochondria and mtDNA in the development of ischaemic heart disease and stroke is likely to be larger than originally thought, with the novel discovery of links among mitochondria, mtDNA and vascular events. Here we explore the molecular events and mtDNA alterations in relation to the role of mitochondria in ischaemic heart disease and stroke.

Novel association between bone mineral density scores and the prevalence of peripheral artery disease in both sexes

The purpose of the current study was to investigate the association between bone mineral density (BMD) scores and the prevalence of peripheral artery disease (PAD) in a large cohort of subjects who underwent arterial Doppler assessments and calcaneal bone densitometry. The study was performed using data obtained from Life Line Screening Inc. Subjects were self-selected and paid for screening tests. The prevalence of PAD was significantly higher in men with osteopenia (4.5%) and osteoporosis (10.9%) compared to men with normal BMD (3.0%) ( p<0.001). Osteopenia (odds ratio (OR) 1.3) and osteoporosis (OR 2.3) were found to be independent risk factors for the presence of PAD in men. The prevalence of PAD was significantly higher in women with osteopenia (4.8%) and osteoporosis (11.8%) compared to women with normal BMD (3.3%) ( p<0.001). Osteopenia (OR 1.15) and osteoporosis (OR 1.8) were found to be independent risk factors for the presence of PAD in women. The current study reports a strong association of abnormal BMD analysis with the prevalence of PAD, which persists even when controlling for age and associated atherosclerotic risk factors. Although the mechanism by which these two disease processes is related is not completely elucidated, the presence of osteoporosis should make clinicians aware of the possibility of occult PAD or associated atherosclerotic disease in appropriate patients.

Glutathione S-Transferase T1 (GSTT1) Null Polymorphism, Smoking, and Their Interaction in Coronary Heart Disease: A Comprehensive Meta-Analysis

BACKGROUND

The association between glutathione S-transferase T1 (GSTT1) null polymorphism and coronary heart disease (CHD) is inconsistent among studies, and data on the GSTT1 null genotype-smoking interplay in CHD is lacking. We conducted this meta-analysis to investigate the relationship between GSTT1 null polymorphism and CHD and to assess the potential interaction between GSTT1 null genotype and smoking.

METHODS

PubMed and EMBASE databases were searched up to 27 January 2016 using the appropriate terms. Odds ratios were pooled using either fixed-effects or random-effects models.

RESULTS

Twenty-nine articles including 31 studies with 15,004 cases and 35,597 controls were eligible. The random-effects model showed that the GSTT1 null genotype was associated with increased CHD risk (OR=1.213, 95%CI: 1.004-1.467; I²=90.4%). After excluding 10 studies detected by Galbraith plot, the fixed effects summary estimate also showed an increased risk of CHD (OR=1.14, 95% CI: 1.06-1.22; I²=27.7%). A case-only analysis including eight studies showed a statistically significant positive interaction between GSTT1 null polymorphism and smoking status on CHD (OR=1.34, 95% CI: 1.09-1.64; I²=0%). Sensitivity analyses further supported the associations. No publication bias was observed.

CONCLUSIONS

This meta-analysis suggests that GSTT1 null polymorphism is associated with the risk of CHD. To our knowledge, this is the first meta-analysis to prove a positive effect of the interaction between GSTT1 null genotype and smoking status on the risk of CHD. Future studies with detailed individual information are needed to confirm our findings.

The Associations Between the Polymorphisms of Vitamin D Receptor and Coronary Artery Disease: A Systematic Review and Meta-Analysis

Vitamin D receptor (VDR) polymorphisms were indicated to be associated with coronary artery disease (CAD); however, published studies reported inconsistent results.The aim of this meta-analysis is to reach a more accurate estimation of the relationship between VDR genetic polymorphisms and CAD risk.Eligible studies were retrieved by searching PubMed, Embase, VIP, Wanfang and China National Knowledge Infrastructure databases. Included and excluded criteria were formulated. The case group was patients with CAD, and the control group was healthy subjects. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate VDR polymorphisms associations with CAD risk. Heterogeneity was evaluated by Q statistic and I statistic.Seven studies of a total of 2306 CAD patients and 4151 control subjects met the inclusion criteria. The pooled results from Taq1 showed increased risk in allelic model (OR = 1.14, 95% CI = 1.02-1.28), dominant model (OR = 1.21, 95% CI = 1.02-1.43), heterozygote model (OR = 1.19, 95% CI = 1.00-1.1.42), and homozygote model (OR = 1.27, 95% CI = 1.01-1.61). Besides, Fok1 T > C showed decreased risk in allelic model (OR = 0.81, 95% CI = 0.65-1.00) and Fok1 A > G also showed decreased risk in allelic model (OR = 0.67, 95% CI = 0.45-1.00) and recessive model (OR = 0.55, 95% CI = 0.31-0.97). In Caucasian subgroup, Bsm1showed increased risk in allelic model (OR = 1.23, 95% CI = 1.02-1.47), heterozygote model (OR = 1.20, 95% CI = 1.00-1.44), and homozygote model (OR = 1.22, 95% CI = 1.02-1.45). In CAD patients with type 2 diabetes mellitus (T2DM), Apa1showed a decreased risk in heterozygote model (OR = 0.80, 95% CI = 0.66-0.98); however, increased risk in recessive model (OR = 5.00, 95% CI = 2.74-9.13) was discovered in CAD patients without T2DM.The Fok1 polymorphism may play a protective role in CAD, and the possible protective role in Apa1 CA genotype in CAD patients with T2DM needs further studies. The Taq1 polymorphism is found to be associated with a significant increase in CAD risk based on our analysis; moreover, increased risk in Apa1 polymorphism in CAD patients without T2DM and Bsm1 polymorphism in Caucasian group is also detected.

Genetic Variations in the Vitamin D Receptor Predict Type 2 Diabetes and Myocardial Infarction in a Community-Based Population: The Tromsø Study

BACKGROUND

Though the associations between low serum 25-hydroxyvitamin D (25(OH)D) levels and health outcomes such as type 2 diabetes (T2D), myocardial infarction (MI), cancer, and mortality are well-studied, the effect of supplementation with vitamin D is uncertain. This may be related to genetic differences. Thus, rs7968585, a single nucleotide polymorphism (SNP) of the vitamin D receptor (VDR), has recently been reported as a predictor of composite health outcome. We therefore aimed to evaluate whether rs7968585 predicts separate clinical outcomes such as T2D, MI, cancer, and mortality in a community-based Norwegian population.

METHODS AND FINDINGS

Measurements and DNA were obtained from the participants in the Tromsø Study in 1994-1995, registered with the outcomes of interest and a randomly selected control group. The impact of the rs7968585 genotypes was evaluated with Cox proportional hazards. A total of 8,461 subjects were included among whom 1,054 subjects were registered with T2D, 2,287 with MI, 3,166 with cancer, and 4,336 with death. Mean follow-up time from birth was 60.8 years for T2D and MI, 61.2 years for cancer, while mean follow-up time from examination date was 16.5 years for survival. Mean serum 25(OH)D levels did not differ across the rs7968585 genotypes. With the major homozygote genotype as reference, the minor homozygote subjects had hazard ratios of 1.25 (95% CI 1.05-1.49) for T2D and 1.14 (1.02-1.28) for MI (P = 0.011 and 0.023, respectively, without the Bonferroni correction). No significant interaction between serum 25(OH)D status and the rs7968585 genotype was found for any of the endpoints.

CONCLUSIONS

The VDR-related SNP rs7968585 minor allele is a significant and positive predictor for T2D and possibly for MI. Since the functional mechanism of this SNP is not yet understood, and the association with T2D is reported for the first time, confirmatory studies are needed.

Effects of Smoking on Arterial Stiffness in Male Adolescents in Lusaka, Zambia

Background

Tobacco smoke is harmful to health. In the acute phase it causes changes in the cardiovascular system that result in an increase in blood pressure (BP). An increase in arterial stiffness due to arteriolar endothelial dysfunction has been cited among the causes. Pulse Wave Velocity (PWV) and Arterial Stiffness Index (ASI) are used as measures of arterial stiffness in the adult population.

Aim

To determine the acute effects of tobacco smoke on arterial stiffness in black male adolescents in Lusaka, Zambia.

Study Design

This was an observational study done at the University of Zambia School of Medicine Cardiovascular Research Laboratory in the month of December 2014.

Methodology

Twenty-two (22) black, male-adolescent (age range 19-25 years), active-smokers, consented to participate in the study. The Complior Analyse Unit (V1.9 Beta Version 2013; ALAM-Medical, France) protocol was used to obtain the carotid-femoral PWV (cfPWV) and carotid-femoral ASI (cfASI) starting 15 minutes before smoking, on immediate cessation of smoking and thereafter every 15 minutes up to an hour after smoking. ASI was a surrogate measure of the loss of elasticity in the arteries.

Results

The mean baseline cfPWV was 7.9±1.94 m/s and cfASI was 26.1±6.0 m/s. Smoking two tobacco cigarettes (2.8 mg Nicotine) in 15 minutes caused an increase in mean cfPWV and cfASI from their baseline values to cfPWV of 8.5±1.87 m/s and cfASI of 28.6±6.19 m/s respectively. These values reverted to baseline within 15 minutes post-smoking cessation. There was further reduction in both cfPWV and cfASI to more stable values at 45^th and 60^th minutes which were statistically significantly lower than the peak values recorded.

Conclusion

The mean baseline cfPWV and cfASI in these late adolescents were comparatively higher than those recorded in non-smoking black adolescents and smoking white men and women. These recordings were also much higher than the values recorded 60 minutes after cessation of smoking. Compared to these values, we conclude that tobacco smoke may be the cause of the significant acute increase in cfPWV and cfASI in African male adolescents presumably signifying an increase in arterial stiffness probably due to endothelial dysfunction in elastic arteries. These alterations in vascular compliance may predispose these individuals to developing hypertension and other cardiovascular complications. There is need for further investigation of this phenomenon.

Association between GSTM1 null genotype and coronary artery disease risk: a meta-analysis

Background

We conducted a meta-analysis to assess the association between polymorphisms of GSTM1 null genotype and coronary artery disease (CAD) risk.

Material/Methods

Published literature from PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI) were retrieved before March 2014. All studies reporting adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of CAD risk were included.

Results

A total of 13 case-control studies, including 5453 cases and 5068 controls, were collected. There was a significant association between GSTM1 null genotype and CAD risk (adjusted OR=1.26; 95% CI, 1.11–1.43; I²=3%). When stratified by ethnicity, a significantly elevated risk was observed in whites. In the subgroup analysis according to disease type, a significantly increased myocardial infarction (MI) risk was observed. Subgroup analysis of smoking status showed an increased CAD risk in smokers.

Conclusions

Our results indicate that GSTM1 null genotype is associated with an increased CAD risk.

Association between Glutathione S-transferase M1/Glutathione S-transferase T1 polymorphisms and Parkinson's disease: a meta-analysis

The Glutathione S-transferase M1 (GSTM1) and Glutathione S-transferase T1 (GSTT1) genes have been studied extensively as potential candidate genes for the risk of Parkinson's disease (PD). However, direct evidence from genetic association studies remains inconclusive. In order to address this issue, we performed an updated and refined meta-analysis to determine the effect of GSTM1 and GSTT1 polymorphisms on Parkinson's disease. A fixed-effect model was utilized to calculate the combined odds ratio (OR), OR of different ethnicities, and 95% confidence intervals (CIs). Potential publication bias was estimated. Homogeneity of the included studies was also evaluated. The pooled OR was 1.13 [95% CI (1.03, 1.24)] and 0.96 [95% CI (0.82, 1.12)] for GSTM1 and GSTT1 polymorphisms, respectively. Analysis according to different races found no association between GSTM1/GSTT1 polymorphisms and PD risks except for GSTM1 variant in Caucasians, which showed a weak correlation (OR 1.16 [95% CI (1.04, 1.29), I squared=6.2%, p=0.384]). Neither publication bias nor heterogeneity was found among the included studies. The results of this meta-analysis suggest that GSTM1 polymorphism is weakly associated with the risk of PD in Caucasians whereas GSTT1 polymorphism is not a PD risk factor.

Molecular studies on coronary artery disease-a review

Coronary artery disease (CAD) remains the major cause of mortality and morbidity in the entire world population. The conventional risk factors of CAD include hypertension, hyperlipidemia, diabetes mellitus, family history, smoking etc. These factors contribute only 50 % of the total risk of CAD. For providing a complete risk assessment in CAD, it is mandatory to have well-planned clinical, biochemical and genetic studies in patients with CAD and subjects who are at risk of developing CAD. In this review an attempt is made to critically evaluate the conventional and emerging risk factors which predispose the individual to CAD. Specifically, the molecular basis of CAD including high oxidative stress, low antioxidant status and increased DNA damage are covered. A comprehensive and multifactorial approach to the problem is the better way to reduce the morbidity and mortality of the disease.

Protective cardiovascular and renal actions of vitamin D and estrogen

Both basic science and clinical studies support the concept that vitamin D deficiency is involved in the pathogenesis of cardiovascular and renal diseases through its association with diabetes, obesity, and hypertension. Understanding the underlying mechanisms may provide a rationale for advocating adequate intake of vitamin D and calcium in all populations, thereby preventing many chronic diseases. This review explores the effect of vitamin D deficiency in the development of cardiovascular and renal diseases, and the role of vitamin D supplementation on cardiovascular outcomes. In addition, it highlights the importance of vitamin D intake for the prevention of adverse long-term health consequences, and in ways to facilitate the management of cardiovascular disease. This is particularly true for African American and postmenopausal women, who are at added risk for cardiovascular disease. We suggest that the negative cardiovascular effects of low vitamin D in postmenopausal women could be improved by a combined treatment of vitamin D and sex steroids acting through endothelium-dependent and/or -independent mechanisms, resulting in the generation of nitric oxide and calcitonin gene-related peptide (CGRP).

Glutathione S-transferase M1 and T1 genotypes and myocardial infarction

Myocardial infarction (MI), which is the most important manifestation of coronary artery disease, is the leading cause of morbidity and mortality in the world. Glutathione S transferases (GSTs) are enzymes responsible for the metabolism of numerous xenobiotics and are known to be polymorphic in humans. We investigated the association between the GSTM1 and GSTT1 gene polymorphisms and MI. The study consists of 296 healthy controls and 324 consecutive patients who had undergone coronary angiography for suspicion of coronary artery disease and with a past history of myocardial infarction. DNA was extracted from whole blood of patient and control. GSTM1 and GSTT1 gene polymorphisms were examined using multiplex PCR. We found that the null GSTM1 was associated with protective effect on MI, although this increase was not significant for GSTM1 (p < 0.054). However, GSTT1 genotype was associated with an increase in the risk of developing MI. In addition to after adjusting other all coronary risk factors, the interactive effect of GSTT1 null genotype remained statistically significant (p < 0.001) for MI disease but GSTM1 null genotype was not statistically significant. Patients, who smoke having the null genotypes of GSTM1, were at a higher risk for developing MI (p < 0.001, OR = 0.41, 95 % CI = 0.240-0.207). There was an effect of interaction of GSTM1 null genotype and smoking on MI development between patient and control groups (p < 0.001). Our results showed that individuals with the null genotypes for GSTM1 had protective effect, while GSTT1 was at a higher risk for MI disease. In addition, there was additional effects of smoking when smoking and non-smoking groups were compared.

Risk conferred by FokI polymorphism of vitamin D receptor (VDR) gene for essential hypertension

BACKGROUND:

The vitamin D receptor (VDR) gene serves as a good candidate gene for susceptibility to several diseases. The gene has a critical role in regulating the renin-angiotensin system (RAS) influencing the regulation of blood pressure. Hence determining the association of VDR polymorphisms with essential hypertension is expected to help in the evaluation of risk for the condition.

AIM:

The aim of this study was to evaluate association between VDRFok I polymorphism and genetic susceptibility to essential hypertension.

MATERIALS AND METHODS:

Two hundred and eighty clinically diagnosed hypertensive patients and 200 normotensive healthy controls were analyzed for Fok I (T/C) [rs2228570] polymorphism by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Genotype distribution and allele frequencies in patients and controls, and odds ratios (ORs) were calculated to predict the risk for developing hypertension by the individuals of different genotypes.

RESULTS:

The genotype distribution and allele frequencies of Fok I (T/C) [rs2228570] VDR polymorphism differed significantly between patients and controls (χ² of 18.0; 2 degrees of freedom; P = 0.000). FF genotype and allele F were at significantly greater risk for developing hypertension and the risk was elevated for both the sexes, cases with positive family history and habit of smoking.

CONCLUSIONS:

Our data suggest that VDR gene Fok I polymorphism is associated with the risk of developing essential hypertension

The mitochondrial paradigm for cardiovascular disease susceptibility and cellular function: a complementary concept to Mendelian genetics

While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the original features that molded cellular function were based upon mitochondrial-nuclear relationships established millions of years ago and were likely refined during prehistoric environmental selection events that today, are largely absent. Consequently, contemporary risk factors that influence our susceptibility to a variety of age-related diseases, including CVD were probably not part of the dynamics that defined the processes of mitochondrial-nuclear interaction, and thus, cell function. In this regard, the selective conditions that contributed to cellular functionality and evolution should be given more consideration when interpreting and designing experimental data and strategies. Finally, future studies that probe beyond epidemiologic associations are required. These studies will serve as the initial steps for addressing the provocative concept that contemporary human disease susceptibility is the result of selection events for mitochondrial function that increased chances for prehistoric human survival and reproductive success.

Vitamin D deficiency, vitamin D receptor gene polymorphisms and cardiovascular risk factors in Caribbean patients with type 2 diabetes

AIM

The prevalence of diabetes in the French West Indies is three times higher than in mainland France. We aimed to assess the associations between vitamin D deficiency, vitamin D receptor (VDR) gene polymorphisms and cardiovascular risk factors in Caribbean patients with type 2 diabetes (T2D).

METHODS

In this cross-sectional study of 277 patients, 25-hydroxyvitamin D was measured by radioimmunoassay. FokI, BsmI, ApaI and TaqI single nucleotide polymorphisms (SNPs) of the VDR gene were genotyped. Analysis of covariance and logistic regression were performed.

RESULTS

The study included 76 patients of Indian descent and 201 patients of African descent. The prevalence of vitamin D deficiency (<20 ng/mL) was 42.6%. When patients were classified into groups with (G1) and without (G2) vitamin D deficiency, there were no significant differences in age, systolic blood pressure, low-density lipoprotein cholesterol and HbA(1c), although body mass index was significantly higher in G1. Vitamin D deficiency was significantly associated with increased diastolic blood pressure and triglyceride levels, and reduced high-density lipoprotein cholesterol (P<0.05). Prevalence of vitamin D deficiency was decreased in patients carrying the f allele of FokI (OR: 0.52; P=0.02) and the aa genotype of ApaI (OR: 0.46; P=0.05). BsmI and TaqI SNPs were not associated with vitamin D deficiency.

CONCLUSION

The rate of vitamin D deficiency was high in our T2D patients, and was associated with the VDR gene FokI and ApaI polymorphisms and cardiovascular risk profile. Measurements of vitamin D may help to detect T2D patients with cardiovascular risk, and VDR polymorphisms might explain why vitamin D deficiency is so frequently seen in some T2D patients.

The association between GSTT1, M1, and P1 polymorphisms with coronary artery disease in Western Iran

DNA damage which occurred by the effect of oxidant and mutant agents has an essential role in the development of atherosclerosis. To investigate the possible association between GSTs polymorphism with coronary artery disease (CAD), we investigated the frequency of GSTT1, M1, and P1 genotypes in patients with CAD compared to controls. The genotypes of GSTT1, M1, and P1 were determined in 209 angiographically documented CAD patients and 108 normal coronary artery cases (as controls) by Multiplex Polymerase Chain Reaction and PCR-RFLP. In CAD patients, the frequency of GSTT1-null genotype was significantly (P = 0.025) lower than that in control. The presence of this genotype was associated with 2.2-fold increased risk of CAD. However, the frequency of GSTM1 and GSTP1 genotypes were not significantly different comparing both groups (P = 0.405 and P = 0.521, respectively). Moreover, non smokers patients had a lower frequency of GSTM1-null genotype (29.2%) compared to non smoker controls (43.5%, P = 0.043). Also, the frequency of both GSTT1-null and GSTM1-null genotypes in patients (3.8%) was significantly lower compared to controls with the same genotypes (10.2%, P = 0.014). Our results indicated that a reduction in the frequency of GSTT1-null and GSTM1-null genotypes that observed in our study might be involved in the pathogenesis of CAD in our population.

The association of micronucleus frequency with obesity, diabetes and cardiovascular disease

Obesity and metabolic syndrome (MetS) are serious and growing health care problems worldwide, leading an increased risk for type 2 diabetes (T2D) and cardiovascular disease (CVD). Over the past decade, emerging evidence has shown that an increased chromosomal damage, as determined by the cytokinesis-block micronucleus (CBMN) assay, is correlated to the pathogenesis of metabolic and CVD. An increased micronuclei (MN) frequency has been demonstrated in peripheral blood lymphocytes of patients with polycystic ovary syndrome, a common condition in reproductive-aged women associated with impaired glucose tolerance, T2D mellitus and the MetS. High levels of MN have been detected to be significantly correlated with T2D as well as with the occurrence and the severity of coronary artery disease (CAD). Long-term follow-up studies have shown that an increased MN frequency is a predictive biomarker of cardiovascular mortality within a population of healthy subjects as well as of major adverse cardiovascular events in patients with known CAD. Overall, these findings support the hypothesis that CBMN assay may provide an useful tool for screening of the MetS and its progression to diabetes and CVD in adults as well in children. Large population-based cohorts are needed in order to compare the MN frequencies as well as to better define whether MN is a biomarker or a mediator of cardiometabolic diseases.

Decreases in binding capacity of the mitochondrial 18 kda translocator protein accompany oxidative stress and pathological signs in rat liver after DMBA exposure

7,12-Dimethylbenz[a]anthracene (DMBA) presents a pollutant implicated in various toxicological effects. The aim of this experiment was to study the effects of DMBA administration on oxidative stress, histopathological signs, and 18 kDa translocator protein (TSPO) binding characteristics in rat liver. We also studied the effects of dose stoichiometry, dose frequency, and duration of protocol of DMBA administration. In this study, rats surviving eighteen weeks after DMBA exposure showed mild to moderate histopathological changes in the liver, mainly characterized by glossy appearance of hepatocytes, heterochromatic nuclei, and glycogen overload in the midzonal region of the hepatic lobe. These changes were accompanied by significant rises in oxidant levels, along with declines in nonenzymic antioxidants, indicating that DMBA induced oxidative stress in the liver. This finding correlated well with decreases in TSPO binding capacity in the liver of the rats in our study. Other studies have shown that TSPO can be affected by oxidative stress, as well as contribute to oxidative stress at mitochondrial levels. Further studies are needed to assay whether the decreases in TSPO density in the liver are part of the damaging effects caused by DMBA or a compensatory response to the oxidative stress induced by DMBA.

Genetic determinants of osteoporosis: common bases to cardiovascular diseases?

Osteoporosis is the most common and serious age-related skeletal disorder, characterized by a low bone mass and bone microarchitectural deterioration, with a consequent increase in bone fragility and susceptibility to spontaneous fractures, and it represents a major worldwide health care problem with important implications for health care costs, morbidity and mortality. Today is well accepted that osteoporosis is a multifactorial disorder caused by the interaction between environment and genes that singularly exert modest effects on bone mass and other aspects of bone strength and fracture risk. The individuation of genetic factors responsible for osteoporosis predisposition and development is fundamental for the disease prevention and for the setting of novel therapies, before fracture occurrence. In the last decades the interest of the Scientific Community has been concentrated in the understanding the genetic bases of this disease but with controversial and/or inconclusive results. This review tries to summarize data on the most representative osteoporosis candidate genes. Moreover, since recently osteoporosis and cardiovascular diseases have shown to share common physiopathological mechanisms, this review also provides information on the current understanding of osteoporosis and cardiovascular diseases common genetic bases.

DNA repair gene polymorphism is associated with the genetic basis of atherosclerotic coronary artery disease

BACKGROUND

Atherosclerotic coronary artery disease (CAD) is a multifactorial process that appears to be caused by the interaction of environmental risk factors with multiple predisposing genes. It is nowadays accepted that increased levels of DNA damage induced by xenobiotics play an important role in the early phases of atherogenesis. Therefore, in this study, we focus on determining whether genetic variations in xenobiotic-metabolizing [glutathione-S-transferase theta 1 (GSTT1), glutathione-S-transferase mu 1 (GSTM1), cytochrome P450 IIEI (CYP2E1)] and DNA repair [X-ray cross-complementing group 1 (XRCC1)] genes might be associated with increased risk for CAD.

METHODS

A case-control study was conducted with 400 individuals who underwent subjected to coronary angiography. A total of 299 were patients diagnosed with effective coronary atherosclerosis (case group; >20% obstructive lesion), and 101 (control group) were individuals diagnosed as negative for CAD (<20% obstructive lesions). The polymorphism identifications for GSTM1 and GSTT1, and for CYP2E1 and XRCC1 genes were performed by polymerase chain reaction (PCR) amplification and by PCR-RFLP, respectively.

RESULTS AND CONCLUSIONS

The XRCC1 homozygous wild-type genotype Arg/Arg for codon 399 was statistically less pronounced in the case subjects (21.4%) than in controls (38.5%); individuals with the variant XRCC1 genotype had a 2.3-fold increased risk for coronary atherosclerosis than individuals with the wild-type genotype (OR=2.3, 95% CI=1.13-4.69). Conversely, no association between GSTM1, GSTT1, and CYP2E1gene polymorphisms and coronary atherosclerosis was detected. The results provide evidence of the role of DNA damage and repair in cardiovascular disease.

No association between vitamin D receptor polymorphisms and coronary artery disease in a Chinese population

The clinical features suggest that genetic factors may have a strong influence on susceptibility to coronary artery disease (CAD). The aim of this study was to investigate the association between FokI (rs2228570) and BsmI (rs1544410) of the vitamin D receptor (VDR) gene polymorphisms and patients with CAD in a Chinese population. One hundred and fifty-two CAD patients and 212 healthy controls were genotyped for the FokI and BsmI polymorphisms in VDR gene using polymerase chain reaction-restriction fragment length polymorphism. No significant differences were observed in the genotype and allele frequencies of the FokI and BsmI polymorphisms between the cases and controls (For FokI: odds ratio = 1.11, 95% confidence interval 0.83-1.50; for BsmI: odds ratio = 0.74, 95% confidence interval 0.44-1.23). There was no significant difference in the genotype distribution or the allele frequencies of VDR FokI and BsmI between two groups in a Chinese population.

Role of dietary mutagens in cancer and atherosclerosis

PURPOSE OF REVIEW

To provide an updated summary of dietary mutagens and their potential role in the etiology of cancer and atherosclerosis.

RECENT FINDINGS

Compelling evidence supports an accumulation of somatic mutations during carcinogenesis, leading to the activation of oncogenes or inactivation of tumor suppressor genes or both. There is also suggestive evidence that mutation provides an early event in atherosclerosis. Genome-wide association studies (GWAS) identify genes associated with familial cancers and atherosclerosis, but genes involved in sporadic events are less well characterized. Many dietary components are mutagenic, including natural dietary components, mutagens generated during cooking and processing of food or through contamination. Molecular epidemiology associates specific mutagens with specific types of cancer. Although chromosome mutations may provide a risk biomarker for atherosclerosis, they are not necessarily causal.

SUMMARY

Association studies, supported by molecular epidemiology, provide evidence that certain dietary mutagens, including aflatoxin B1, aristolochic acid and benzo[a]pyrene, are causal in some human cancers. Similar studies have correlated the level of oxidative DNA damage, DNA adducts and clastogenesis in arterial smooth muscle cells with atherogenic risk factors described through traditional epidemiology. However, establishing whether or not dietary mutagens lead to mutations that are causal in atherosclerosis remains a challenge for the newer genomic technologies.

Atherosclerosis and osteoporosis: age-dependent degenerative processes or related entities?

Osteoporosis and atherosclerosis, two multifactorial and degenerative entities, are major public health problems. These diseases accompany the aging process and share common risk factors. Furthermore, several common pathophysiological factors have been suggested. These include similar molecular pathways involving bone and vascular mineralization, estrogen deficiency, parathyroid hormone, homocysteine, lipid oxidation products, inflammatory process, as well as vitamin D and K. Moreover, the use of statins, biphosphonates, beta-blockers and experimental dual-purpose therapies based on the biological linkage of the above entities may simultaneously benefit bone loss and vascular disease. This review considers a potential link between osteoporosis and atherosclerosis beyond aging. These common factors may lead to appropriate treatment strategies.

Relation of increased chromosomal damage to future adverse cardiac events in patients with known coronary artery disease

Somatic deoxyribonucleic acid (DNA) damage has been associated with early-phase and/or acute complications of atherosclerosis. However, it remains unclear whether circulating levels of DNA damage have prognostic value in patients with coronary artery disease (CAD). The aim of this study was to assess the prognostic significance of chromosomal DNA damage in human lymphocytes on the rate of major adverse cardiovascular events in patients with CAD. A follow-up prospective cohort study was carried out of 178 patients (153 men, mean age 61.9 +/- 9.7 years) with angiographically proved CAD who underwent micronucleus assay, a sensitive biomarker of chromosomal damage and genetic instability, from March 1999 and June 2001. During a mean follow-up period of 51.4 +/- 23.8 months, 58 patients had major adverse cardiovascular events (cardiac death, myocardial infarction, stroke, congestive heart failure, unstable angina, or coronary and peripheral revascularization). The overall event-free survival rates were 77.5%, 70.4%, and 49.0% in patients in the lower, middle, and upper tertiles of micronucleus level, respectively (log rank = 11.5, p = 0.003). In a multivariate Cox regression model, only the upper tertiles were significantly associated with a higher risk for major adverse cardiovascular events (hazard ratio 2.2, 95% confidence interval 1.1 to 4.7, p = 0.03). In conclusion, levels of peripheral chromosomal DNA damage may be a new sensitive biomarker of prognostic stratification in patients with known CAD.

Gene-environment interaction in tobacco-related cancers

This review summarizes the carcinogenic effects of tobacco smoke and the basis for interaction between tobacco smoke and genetic factors. Examples of published papers on gene-tobacco interaction and cancer risk are presented. The assessment of gene-environment interaction in tobacco-related cancers has been more complex than originally expected for several reasons, including the multiplicity of genes involved in tobacco metabolism, the numerous substrates metabolized by the relevant genes and the interaction of smoking with other metabolic pathways. Future studies on gene-environment interaction and cancer risk should include biomarkers of smoking dose, along with markers of quantitative historical exposure to tobacco. Epigenetic studies should be added to classic genetic analyses, in order to better understand gene-environmental interaction and individual susceptibility. Other metabolic pathways in competition with tobacco genetic metabolism/repair should be incorporated in epidemiological studies to generate a more complete picture of individual cancer risk associated with environmental exposure to carcinogens.

Exposure of mice to cigarette smoke and/or light causes DNA alterations in heart and aorta

Cigarette smoke (CS) is a major risk factor for cardiovascular diseases, cancer, and other chronic degenerative diseases. UV-containing light is the most ubiquitous DNA-damaging agent existing in nature, but its possible role in cardiovascular diseases had never been suspected before, although it is known that mortality for cardiovascular diseases is increased during periods with high temperature and solar irradiation. We evaluated whether exposure of Swiss CD-1 mice to environmental CS (ECS) and UV-C-covered halogen quartz lamps, either individually or in combination, can cause DNA damage in heart and aorta cells. Nucleotide alterations were evaluated by (32)P postlabeling methods and by HPLC-electrochemical detection. The whole-body exposure of mice to ECS considerably increased the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and of bulky DNA adducts in both heart and aorta. Surprisingly, even exposure to a light that simulated solar irradiation induced oxidatively generated damage in both tissues. The genotoxic effects of UV light in internal organs is tentatively amenable to formation of unidentified long-lived mutagenic products in the skin of irradiated mice. Nucleotide alterations were even more pronounced when the mice were exposed to smoke and/or light during the first 5 weeks of life rather than during adulthood for an equivalent period of time. Although the pathogenetic meaning is uncertain, DNA damage in heart and aorta may tentatively be related to cardiomyopathies and to the atherogenesis process, respectively.

Genetic polymorphisms of vitamin D receptor (VDR) in Fabry disease

Fabry disease, an X-linked inborn error of metabolism, is characterized by multi-organ involvement including cardiac signs of left ventricular hypertrophy and abnormal intima-medial (IMT) thickening of arteries, progressive renal failure, neurological involvement, and more. The vitamin D receptor (VDR) and an enzyme producing vitamin D3 result in an autocrine loop with direct effects on blood vessels. The purpose of this study is to assess VDR polymorphisms (BsmI, FokI, ApaI, and TaqI) relative to clinically important disease parameters using a disease-specific severity score (MSSI) and haplotype analysis. There were statistically significant differences between females (43% of 74 patients) and males in MSSI total scores, and in general and neurologic sub-scores. There appears to be a protective effect of the TaqI tt genotype so that there were significantly lower scores in clinical categories between those with the tt genotype versus those with the TT genotype. Multivariate models of haplotypes with MSSI scores reveal that T-A-f-B and t-a-F-b haplotypes of the VDR gene polymorphisms are significantly associated with variation in the Fabry phenotype. Despite the limitations of using the MSSI score as a clinical correlate, these results are provocative and further studies in larger cohorts with more males are recommended.

Vitamin D and cardiovascular disease risk

PURPOSE OF REVIEW

Despite our understanding of how to prevent and treat traditional cardiovascular risk factors, cardiovascular disease remains the leading cause of death of both men and women in the US. Thus, there is widespread interest in a number of emerging nontraditional risk factors for the detection of early cardiovascular disease in order to implement aggressive preventive therapies. 25-Hydroxyvitamin D deficiency has been identified as a potential novel cardiovascular disease risk factor. This review outlines what is known about the association of 25-hydroxyvitamin D levels and cardiovascular disease risk.

RECENT FINDINGS

Low 25-hydroxyvitamin D levels have been associated with the cardiovascular disease risk factors of hypertension, obesity, diabetes mellitus and the metabolic syndrome, as well as cardiovascular disease events including stroke and congestive heart failure. Studies suggest vitamin D deficiency may be a contributor to the development of cardiovascular disease potentially through associations with diabetes or hypertension.

SUMMARY

Vitamin D deficiency is easy to screen for and easy to treat with supplementation. Further larger observational studies and randomized clinical trials are, however, needed to determine whether vitamin D supplementation could have any potential benefit in reducing future cardiovascular disease events and mortality risk.

Lipid peroxidation-derived etheno-DNA adducts in human atherosclerotic lesions

Atherosclerosis and cancer are characterized by uncontrolled cell proliferation and share common risk factors, such as cigarette smoking, dietary habits and ageing. Growth of smooth muscle cells (SMCs) in atherosclerotic plaques may result from DNA damage, caused either by exogenous mutagens or by agents endogenously generated due to oxidative stress and lipid peroxidation (LPO). Hydroxy-2-nonenal (HNE), a major LPO product, binds covalently to cellular DNA to form the exocyclic etheno-DNA-base adducts, 1,N(6)-ethenodeoxyadenine (varepsilondA) and 3,N(4)-ethenodeoxycytosine (varepsilondC). By applying an ultrasensitive (32)P-postlabeling-immunoaffinity method, varepsilondA and varepsilondC were quantified in abdominal aorta SMCs from 13 atherosclerotic patients and 3 non-smoking subjects without atherosclerotic lesions. The levels of etheno-adducts ranged for varepsilondA from 2.3 to 39.6/10(8)dA and for varepsilondC from 10.7 to 157.7/10(8)dC, with a high correlation between varepsilondA and varepsilondC (r=0.84, P=0.0001). Etheno-adduct levels were higher in atherosclerotic smokers than in ex-smokers for both varepsilondA (means 15.2 versus 7.3, P=0.06) and varepsilondC (71.9 versus 51.6, not significant). varepsilondC levels were higher in either ex-smokers (P=0.03) or smokers (P=0.07) than in non-smokers. There was a poor correlation between either varepsilondA or varepsilondC and 8-hydroxy-2'-deoxyguanosine, whereas significant positive correlations were detected with the levels of several postlabeled bulky aromatic DNA adducts. In conclusion, two different types of DNA damage may be involved in atherosclerotic plaque formation and progression: (i) bulky aromatic compounds, to which aorta SMCs are chronically exposed in smokers, can either covalently bind to DNA, induce redox-cycling via quinone intermediates and/or activate local chronic inflammatory processes in the arterial wall; ii) this in turn leads to a self perpetuating generation of reactive oxygen species, LPO-products and increasing DNA-damage, as documented by the presence of high levels of miscoding etheno-DNA adducts in human aorta SMCs.

Mutagenesis and cardiovascular diseases Molecular mechanisms, risk factors, and protective factors

Although no generalization can be made, it is of interest that cancer, cardiovascular diseases, and other chronic conditions often share common risk factors and common protective factors as well as common pathogenetic determinants, such as DNA damage, oxidative stress, and chronic inflammation. Atherosclerosis is the most important cause of vascular forms representing the major cause of death in the population of many geographical areas. A great deal of studies support the "response-to-injury" theory. A variety of experimental and epidemiological findings are also in favor of the somatic mutation theory, which maintains that the earliest event in the atherogenic process is represented by mutations in arterial smooth muscle cells, akin to formation of a benign tumor. These two theories can be harmonized, also taking into account the highly diversified nature of atherosclerotic lesions. Molecular epidemiology studies performed in our laboratory and other laboratories have shown that DNA adducts are systematically present in arterial smooth muscle cells, and their levels are correlated with atherogenic risk factors known from traditional epidemiology. Oxidative DNA damage was also consistently detected in these cells. The role of glutathione S-transferase polymorphisms on the frequency of the above molecular alterations and of arterial diseases is rather controversial. Prevention of both cancer and atherosclerosis is based on avoidance of exposure to risk factors and on fortification of the host defense mechanisms by means of dietary principles and chemopreventive drugs.

Identification of multiple MAPK-mediated transcription factors regulated by tobacco smoke in airway epithelial cells

Activation and regulation of transcription factors (TFs) are the major mechanisms regulating changes in gene expression upon environmental exposure. Tobacco smoke (TS) is a complex mixture of chemicals, each of which could act through different signal cascades, leading to the regulation of distinct TFs and alterations in subsequent gene expression. We proposed that TS exposure affects inflammatory gene expression at the transcriptional level by modulating the DNA binding activities of TFs. To investigate transcriptional regulation upon TS exposure, a protein/DNA array was applied to screen TFs that are affected by TS exposure. This array-based screening allowed us to simultaneously detect 244 different TFs. Our results indicated that multiple TFs were rapidly activated upon TS exposure. DNA-binding activity of differentially expressed TFs was confirmed by EMSA. Our results showed that at least 20 TFs displayed more than twofold expressional changes after smoke treatment. Ten smoke-induced TFs, including NF-kappaB, VDR, ISRE, and RSRFC4, were involved in MAPK signaling pathways. The NF-kappaB family, which is involved in inflammation-induced gene activation, was selected for further study to characterize TS exposure-induced transcriptional activation. Western blot analysis and immunofluorescence microscopy indicated that TS exposure induced phosphorylation of IkappaB and translocation of NF-kappaB p65/p50 heterodimers into the nucleus. This activity was abrogated by the MAPK inhibitors PD98059 and U0126. Our results confirmed that activation of MAPK signaling pathways by TS exposure increased transcriptional activity of NF-kappaB. These data provide a potential mechanism for TS-induced inflammatory gene expression.