The Impact on Coronary Artery Disease of Common Polymorphisms Known to Modulate Responses to Pathogens

Vitamin D Receptor (VDR) Gene Polymorphisms and Risk of Coronary Artery Disease (CAD): Systematic Review and Meta-analysis

Several studies have noted that vitamin D receptor (VDR) gene polymorphisms are involved in the susceptibility to Coronary artery disease (CAD). Nonetheless, the results have been inconclusive. Here, we performed the most up-to-date analysis of the association between VDR gene polymorphisms and risk of CAD. We conducted a comprehensive systematic search in the major electronic database, including Scopus and PubMed to look up for relevant studies evaluating the association between the VDR gene FokI (rs2228570), TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232) polymorphisms and susceptibility to CAD published before December 2019. The level of association between VDR gene polymorphisms and susceptibility to CAD in the polled analysis was calculated by odds ratio (OR) and the corresponding 95% confidence interval (CI). We found 14 articles containing 20,398 cases and 9371 controls. The analysis revealed that all genetic models in the FokI SNP were associated with increased risk of CAD. Furthermore, for the ApaI SNP, except recessive model, all other genetic models significantly increased the risk of CAD in the overall analysis. In addition, it was divulged that both FokI and ApaI SNPs were involved in increasing the risk of CAD in Asians and Europeans in a number of models. FokI and ApaI polymorphisms may confer a susceptibility genetic risk factor for development of CAD, particularly in the Asian population.

Association of IL-10-1082A/G polymorphism with cardiovascular disease risk: Evidence from a case-control study to an updated meta-analysis

BACKGROUND

Previous studies have generated controversial results about the association of interleukin 10 (IL-10) gene polymorphisms (-1082G/A) in the progression of cardiovascular disease (CVD). Therefore, this study processed a systemic meta-analysis to verify this association.

METHODS

The publication studies on the IL-10 (-1082G/A) polymorphism and CVDs risk were obtained by searching PubMed and Embase databases. We analyzed the genotype data for meta-analysis. The results were evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). Meanwhile, our meta-analysis was also performed sensitivity analyses, heterogeneity test, and identification of publication bias.

RESULTS

The present meta-analysis suggested that the risk with allele G is lower than with allele A for CVD. The G allele of IL-10 (-1082) could increase the risk of CVDs in the 31 case-control studies for all genetic models. (OR = 1.10, 95% CI: 1.04-1.15 for the allele model A vs. G; OR = 0.87, 95% CI: 0.72-1.04 for the dominant model GG+AG vs. AA; OR = 1.03, 95% CI: 1.02-1.05 for the recessive model GG vs. AG + AA; OR = 1.06, 95% CI = 1.03-1.10 for the homozygote comparison model GG vs. AA; and OR = 0.88, 95% CI = 0.73-1.06 for the heterozygote comparison model AG vs. AA).

CONCLUSIONS

In genetic models, the association between the IL-10 (-1082G/A) polymorphism and CVDs risk was significant. This meta-analysis proposes that the IL-10 (-1082G/A) polymorphism may serve as a risk factor for CVDs.

Association between Toll-like receptor 4 Asp299Gly polymorphism and coronary heart disease susceptibility

Published data on the association between Toll-like receptor 4 (TLR4) Asp299Gly polymorphism and coronary heart disease (CHD) susceptibility are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. English-language studies were identified by searching PubMed and Embase databases (up to November 2016). All epidemiological studies were regarding Caucasians because no TLR4 Asp/Gly and Gly/Gly genotypes have been detected in Asians. A total of 20 case-control studies involving 14,416 cases and 10,764 controls were included in the meta-analysis. Overall, no significant associations were found between TLR4 Asp299Gly polymorphism and CHD susceptibility in the dominant model (OR=0.89; 95%CI=0.74 to 1.06; P=0.20) pooled in the meta-analysis. In the subgroup analysis by CHD, non-significant associations were found in cases compared to controls. When stratified by control source, no significantly decreased risk was found in the additive model or dominant model. The present meta-analysis suggests that the TLR4 Asp299Gly polymorphism was not associated with decreased CHD risk in Caucasians.

Common Variants of Vitamin D Receptor Gene Polymorphisms and Susceptibility to Coronary Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

ApaI, FokI, TaqI, and BsmI polymorphisms in the vitamin D receptor (VDR) gene have been reported to be associated with the risk of coronary artery disease (CAD), although the results of previous studies have been inconsistent. The aim of this study was to explore whether these polymorphisms play a role in the genetic susceptibility to CAD.

METHODS

A comprehensive search of Medline and Embase databases was conducted for studies evaluating the association between the VDR polymorphisms and CAD risk. Odds ratios with 95% confidence intervals were calculated to assess the strength of association in the dominant model, recessive model, allelic model, and genotypes contrast.

RESULTS

Nine studies involving a total of 5,259 cases and 1,981 controls were finally included in this meta-analysis. Overall, no significant associations were found between ApaI, FokI, TaqI, and BsmI polymorphisms and the risk of CAD in any of the genetic models (all p ˃ 0.05). Moreover, a subgroup analysis by ethnicity did not reveal a significant relationship between any of the examined polymorphisms and CAD risk in Caucasians and East-Asians for any model (all p ˃ 0.05).

CONCLUSION

Current evidence suggests that the ApaI, FokI, TaqI, and BsmI polymorphisms of the VDR gene might not be associated with genetic susceptibility to CAD. Further well-designed studies with large sample sizes are needed to confirm our results.

Association Between 3 IL-10 Gene Polymorphisms and Cardiovascular Disease Risk: Systematic Review With Meta-Analysis and Trial Sequential Analysis

Previous studies have yielded controversial results related to the contribution of interleukin 10 (IL-10) gene polymorphisms (IL-10 -592C/A, IL-10 -1082G/A, and IL-10 -819C/T) in the progression of cardiovascular disease (CVD). Thus, we performed a meta-analysis to summarize this situation.Eligible studies were retrieved by searching PubMed, Embase, Web of Science, and Cochrane Library with the last search up to July 7, 2015. Data were pooled by odds ratios (ORs) and their 95% confidence intervals (CIs). False-positive report probability (FPRP) analysis was conducted for all significant findings. Genotype-based mRNA expression analysis was also performed using data from 270 individuals with different ethnicities.Finally, 19 studies for IL-10 -592C/A polymorphism (7284 cases and 7469 controls), 21 studies for IL-10 -1082G/A polymorphism (8263 cases and 5765 controls), and 12 studies for IL-10 -819C/T polymorphism (4502 cases and 3190 controls) were included in the meta-analyses. With respect to IL-10 -819C/T polymorphism, statistically significant decreased CVD risk was found when all studies were pooled into the meta-analysis (T vs C: OR = 0.91, 95% CI = 0.84-0.98; TT + TC vs CC: OR = 0.90, 95% CI = 0.81-1.00). Subgroup analyses stratified by disease subtype suggested the -819C/T polymorphism was significantly associated with a decreased CAD risk (T vs C: OR = 0.90, 95% CI = 0.83-0.97; TT vs CC: OR = 0.81, 95% CI = 0.66-1.00; TT vs TC + CC: OR = 0.82, 95% CI = 0.69-0.98; TT + TC vs CC: OR = 0.89, 95% CI = 0.80-0.99), which was noteworthy finding as evaluated by FPRP. However, with regard to IL-10 -592C/A and IL-10 -1082G/A polymorphisms, no significant association with CVD risk was observed in the overall and subgroup analyses.In conventional meta-analyses, the results suggested that IL-10 -819C/T polymorphism was associated with decreased risk of CVD, especially CAD outcome, whereas IL-10 -592C/A and IL-10 -1082G/A polymorphisms might have no influence on the susceptibility of CVD. However, trial sequential analysis does not allow us to draw any solid conclusion for the association between IL-10 -592C/A or IL-10 -1082G/A polymorphism and CVD risk. Further large and well-designed studies are still needed.

TLR4 Asp299Gly (rs4986790) polymorphism and coronary artery disease: a meta-analysis

Background. Previous studies have shown conflicting results on the association between toll-like receptor 4 (TLR4) Asp299Gly (rs4986790) polymorphism and coronary artery disease (CAD). The aim of this study was to evaluate the influence of TLR4 Asp299Gly polymorphism on CAD risk, CRP level and the number of stenotic coronary arteries, as well as to investigate whether G allele carriers would benefit more from statin treatment. Methods. PubMed, EMBASE, and CNKI databases were searched until May 2015. All the statistical tests were performed using R version 3.1.2. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the association between TLR4 Asp299Gly polymorphism and CAD risk, the number of stenotic vessels, and the incidence of cardiovascular events according to statin-treated patients. Weighted mean difference (WMD) was calculated for the association between Asp299Gly and CRP level. Results. Overall, 12 case-control studies with 10,258 cases and 5,891 controls were included, and no association of TLR4Asp299Gly polymorphism with CAD was found (G allele vs. A allele: OR = 0.97, 95% CI [0.81-1.17], P = 0.75; AA vs. GG + AG: OR = 0.97, 95% CI [0.80-1.18], P = 0.76; GG vs. AG + AA: OR = 1.08, 95% CI [0.57-2.02], P = 0.82; AG vs. AA + GG: OR = 1.03, 95% CI [0.85-1.25], P = 0.74). Also, no association was noted between Asp299Gly and CRP level (WMD = -0.10, 95% CI [-0.62, 0.41], P = 0.69). Furthermore, no synergistic effect of statin and 299Gly was reported (Statin_AA vs. Statin_

AG/GG

OR = 1.12, 95% CI [0.41-3.09], P = 0.82). Discussion. This meta-analysis suggests no association of TLR4 Asp299Gly polymorphism with CAD and CRP level. It is further indicated that the G allele carriers may not benefit more from statin treatment. Further studies should include large sample size and high-quality literature to understand this issue in depth.

Polymorphisms of the CD14 genes are associated with susceptibility to alcoholic liver disease in Greek patients

BACKGROUND

The incidence and severity of alcoholic liver disease (ALD) in chronic drinkers has been found to correlate with some environmental factors and especially with the dose of alcohol consumption, but it is obvious that other parameters clearly contribute to individual alcohol susceptibility. Chronic ethanol exposure leads to continuous endotoxin-mediated Toll-like receptor-4 (TLR-4) and CD14 activation and subsequent cytokine release resulting in chronic inflammation with continued hepatocellular damage. Therefore, genetic studies of polymorphism in TLR-4 and CD14 genes seem to be appropriate in determining genetic susceptibility to ALD. Our aim is to evaluate in a series of Greek drinkers, the possible association of polymorphisms in the TLR-4 and CD14 genes with ALD.

METHODS

In 96 patients with ALD polymorphism of TLR-4 and CD14 genes were studied compared with 104 patients with cirrhosis of other etiology, 100 healthy subjects, and 50 patients with a history of alcohol abuse but without liver disease.

RESULTS

No association between ALD and the presence of the Asp299Gly and Thr399Ile polymorphisms in the TLR-4 gene could be documented in our patients. Regarding the CD14 -159 (C/T) genotypes, TT genotype and T allele were found to be overrepresented in alcoholic patients compared with patients with nonalcohol-induced liver disease and healthy controls. On the other side, when compared patients with ALD and patients with alcohol abuse and no liver disease, TT genotype was found to be significantly less frequent. There is no statistically significant association with the presence of the T allele and the severity of ALD, suggesting that CD14 polymorphism does not influence disease severity in advanced stages of the disease.

CONCLUSIONS

In our series in Greek patients with alcohol abuse and alcoholic cirrhosis, a significant negative association with the CD14 endotoxin receptor gene polymorphism (TT genotype) but not with the TLR-4 gene polymorphism was documented.

Lack of association between TLR4 Asp299Gly polymorphism and atherosclerosis: evidence from meta-analysis

INTRODUCTION

Toll like receptor 4 (TLR4) expression was found to increase markedly in human atherosclerotic lesions, notably on macrophages and endothelial cells. TLR4 Asp299Gly polymorphism was associated with a blunted receptor activity and a subsequently diminished inflammatory response, and may subsequently reduce atherosclerosis (AS) risk. However, the results of molecular epidemiological studies remained inconsistent.

MATERIALS AND METHODS

The PubMed, CNKI databases were searched for all articles available. The OR corresponding to the 95% confidence interval (95% CI) was used to assess the association between TLR4 Asp299Gly polymorphism and risk of AS.

RESULTS

15 case-control studies with 9,989 cases and 6,746 controls were available for this analysis. For control subjects, G allele frequency of TLR4 Asp299Gly polymorphism was ranging from 0.045 to 0.085. The G allele and the AG/GG genotypes were not associated with significantly risk of AS (OR=1.02, 95% CI=0.83 - 1.26 for G versus A and OR=0.96, 95% CI=0.80 - 1.15 for AG/GG versus AA, respectively) by random effects model.

CONCLUSION

These findings indicated that TLR4 Asp299Gly polymorphism may not play a role in AS development.

Reduced endothelial dependent vasodilation in vessels from TLR4(-/-) mice is associated with increased superoxide generation

Toll like receptor (TLR)4 is a pattern recognition receptor expressed in endothelial and other cells, responsible for the sensing of endotoxin and host derived ligands. Our group has shown previously that the absence of TLR4 is associated with reduced endothelial dependent vasodilator responses and left heart hypertrophy in animal models. However, the mechanism behind reduced endothelial cell function in TLR4^−/− mice is not known.

We have used en face confocal imaging of mesenteric arteries from mice deficient in the TLR4 receptor stained with dihydroethidium (DHE) to measure superoxide production. Using the isometric wire myograph, mesenteric artery vasodilator responses to acetylcholine and MnCl₂ (a superoxide dismutase mimetic) were measured. Mesenteric arteries from TLR4^−/− mice had a reduced endothelial dependent relaxant response and increased superoxide levels when stimulated with acetylcholine. Increased levels of superoxide, as detected by DHE staining, were seen in vessels from TLR4^−/− mice, which were reduced to control levels in the presence of MnCl₂.

Our observations suggest that loss of TLR4 increases superoxide generation which reduces the biological activity of endothelial derived nitric oxide and thereby explains the endothelial dysfunction and associated cardiovascular phenotype in TLR4^−/− mice. These data implicate a novel cardio-protective role for TLR4 in vascular homeostasis.

Vitamin D deficiency and coronary artery calcification in subjects with type 1 diabetes

OBJECTIVE

The objective of this study is to examine the relationship among serum levels of 25-hydroxyvitamin D (25[OH]D), polymorphisms in vitamin D-associated genes, and the presence and progression of coronary artery calcification (CAC) in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

This prospective study included 374 non-Hispanic white individuals with type 1 diabetes (mean age 40 ± 9 years; 46% were male). CAC was measured at the baseline and 3- and 6-year follow-up visits were determined by electron beam computed tomography. Serum 25[OH]D levels were measured by liquid chromatography tandem mass spectrometry at the 3-year visit.

RESULTS

Normal (>30 ng/mL), insufficient (20-30 ng/mL), and deficient (<20 ng/mL) 25-[OH]D levels were present in 65%, 25%, and 10% of the individuals with type 1 diabetes, respectively. 25[OH]D deficiency was associated with the presence of CAC at the 3-year visit, odds ratio (OR) = 3.3 (95% CI 1.6-7.0), adjusting for age, sex, and hours of daylight. In subjects free of CAC at the 3-year visit, 25[OH]D deficiency predicted the development of CAC over the next 3 years in those with the vitamin D receptor M1T CC genotype (OR = 6.5 [1.1-40.2], P = 0.04) than in those with the CT or TT genotype (OR = 1.6 [0.3-8.6], P = 0.57).

CONCLUSIONS

Vitamin D deficiency independently predicts prevalence and development of CAC, a marker of coronary artery plaque burden, in individuals with type 1 diabetes.

ABO blood group alleles: A risk factor for coronary artery disease. An angiographic study

OBJECTIVES

To analyze the impact of ABO groups on coronary heart disease risk factors, coronary involvement and prognosis.

METHODS

An observational single center study was conducted to examine 4901 consecutive patients with heart disease receiving coronary angiography and ABO group determination at National Research Council Institute of Clinical Physiology between January 1993 and December 2003, with maximum 10 years follow-up. All-cause death and cardiac death, were the considered end points.

RESULTS

When compared to the official distribution of ABO groups in the Italian population (O 40%, A 36%, B 17%, AB 7%), a substantially different distribution was observed in the study population (O 43.3%, A 41.4%, B 11.2%, AB 4.1%). In addition, a significant association was found between group non-O and family history of ischemic heart disease, hypercholesterolemia and presence of coronary atherosclerosis. Higher prevalence of A and B alleles was found in patients with myocardial infarction (P<0.05). Group non-O was a powerful predictor of cardiac mortality in patients aged <65 years, particularly in women (HR 1.53, 95% CI 1.06-2.21 and HR 5.29, 95% CI 1.57-17.82, respectively).

CONCLUSIONS

Group non-O is associated with increased mortality in patients with ischemic heart disease. Group non-O increases the risk for cardiac death in non-elderly patients, particularly in younger females, and groups A and B prevail in myocardial infarction. ABO group determination might aid in genetic screening for ischemic heart disease and become relevant in the management of risk factor control.

Genetic polymorphisms in platelet-related proteins and coronary artery disease: investigation of candidate genes, including N-acetylgalactosaminyltransferase 4 (GALNT4) and sulphotransferase 1A1/2 (SULT1A1/2)

BACKGROUND

Both platelet function and heart disease show strong genetic components, many of which remain to be elucidated.

MATERIALS AND METHODS

The roles of candidate polymorphisms in ten platelet-associated genes were compared between 1,237 Acute Coronary Syndrome (ACS) cases (with myocardial infarction and unstable angina) and 386 controls, from an Irish Caucasian population. Additionally, 361 stable angina patients were investigated. Two genes of interest were followed up in a separate Irish study of 1,484 individuals (577 with IHD and 907 unaffected).

RESULTS

The GALNT4 (N-acetyl galactosaminyl transferase 4) 506I allele was significantly underrepresented in ACS (OR = 0.66, CI = 0.52-0.84; P = 0.001; P = 0.01 after correction for multiple testing), while the SULT1A1 (Sulphotransferase 1A1) 213H allele was associated with risk of ACS (OR = 1.37, CI = 1.08-1.74; P = 0.01; P = 0.1 after correction for multiple testing). Subsequent genotyping of further SNPs in GALNT4 in the family-based (IHD) group revealed that the 506I allele showed the same trend towards protecting against ACS but the haplotypic test over the four commonest haplotypes was not significant (P = 0.55). In contrast, the SULT1A1/SULT1A2 gene complex showed suggestive haplotypic association in the family-based study (P = 0.07), with the greatest increase in risk conferred by the SULT1A2 235T allele (P = 0.025).

CONCLUSION

We have identified two risk genes for cardiovascular disease, one of whose (GALNT4) effects may be on either platelet or endothelial function through modifications of PSGL1 or other important glycosylated proteins. The role of sulphotransferases (SULT1A1/2) in cardiovascular disease requires further exploration. Further validation of cardiovascular risks conferred by both genes in other populations (including gene copy number variation) is warranted.

Variants of the interferon regulatory factor 5 gene regulate expression of IRF5 mRNA in atherosclerotic tissue but are not associated with myocardial infarction

BACKGROUND

Signaling events after activation of toll-like receptors (TLRs) are important mechanisms promoting inflammation in the atherosclerotic plaque. INF regulatory factor 5 (IRF5) is one of the mediators of downstream effects of TLRs. Several single nucleotide polymorphisms (SNPs) in the IRF5 gene have been found to be associated with systemic lupus erythematosus.

METHODS AND RESULTS

We examined IRF5 mRNA expression in carotid atherosclerotic tissue (n=99) and the case-control association between SNPs in the IRF5 gene with myocardial infarction (MI) (n=376+387) and unstable coronary artery disease (CAD) (n=3101+445). Among unstable CAD patients, association of IRF5 SNPs with recurrent coronary events (n=401) was also investigated. The IRF5 mRNA expression was increased in atherosclerotic tissue compared with control tissue (P<0.001). Significant associations with IRF5 expression was observed for 6 of 10 SNPs in the study. However, the IRF5 SNPs examined were neither associated with the risk of precocious MI, nor with unstable CAD or risk of recurrent cardiovascular events in unstable CAD patients.

CONCLUSIONS

IRF5 mRNA is expressed in cells in atherosclerotic tissue and its expression is modified by SNPs in the IRF5 gene. Genetic variation at the IRF5 locus was, however, not associated with CAD or related phenotypes.