Assessment of genetic diversity in IL-6 and RANTES promoters and their level in Saudi coronary artery disease patients

Interleukin 6 polymorphisms are associated with cardiovascular risk factors in premature coronary artery disease patients and healthy controls of the GEA Mexican study

BACKGROUND AND AIMS

Interleukin-6 (IL-6) is an acute-phase protein that plays an important role in the inflammatory response, vascular inflammation, and atherosclerosis process. The study aimed to establish whether IL-6 gene polymorphisms and IL-6 concentrations are associated with premature coronary artery disease (pCAD) and cardiovascular risk factors.

METHODS

The IL-6 concentrations and the rs2069827, rs1800796, and rs1800795 IL-6 polymorphisms were determined in 1150 pCAD patients and 1083 healthy controls (coronary artery calcium equal to zero determined by tomography).

RESULTS

The IL-6 polymorphisms studied were not associated with pCAD, but they were associated with cardiovascular risk factors in patients and controls. In controls, under the dominant model, the rs1800795 C allele and the rs2069827 T allele were associated with a low risk of central obesity (OR = 0.401, p = 0.017 and OR = 0.577, p = 0.031, respectively), hypoalphalipoproteinemia (OR = 0.581, p = 0.027 and OR = 0.700, p = 0.014, respectively) and hypertriglyceridemia (OR = 0.575, p = 0.030 and OR = 0.728, p = 0.033, respectively). In pCAD, the rs1800795 C allele was associated with an increased risk of hypoalphalipoproteinemia (OR = 1.370, padditive = 0.025) and increased C-reactive protein (CRP) concentrations (OR = 1.491, padditive = 0.007). pCAD patients had significantly higher serum IL-6 concentrations compared to controls (p = 0.002). In the total population, individuals carrying the rs1800795 GC + CC genotypes had higher levels of IL-6 than carriers of the GG genotype (p = 0.025). In control individuals carrying the C allele (CG + CC), an inverse correlation was observed between IL-6 and HDL-cholesterol levels (p = 0.003).

CONCLUSIONS

In summary, the IL-6 polymorphisms were not associated with pCAD, however, they were associated with cardiovascular risk factors in pCAD patients and healthy controls. Individuals carrying the rs1800795 GC + CC genotypes had higher levels of IL-6 than carriers of the GG genotype.

Association of IL-6 promoter polymorphism hotspots (- 174G/C and - 572G/C) with cardiovascular disease risk factors

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death globally, despite the recent advancements in clinical research. Early diagnosis of CVD and prevention of future complications are important for the management of CVD. In the present study, we determined the genotypic linkage of interleukin-6 (IL-6) promoters with the clinical, biochemical, and inflammatory markers of CVD in the Saudi population.

MATERIALS AND METHODS

The study consisted of 89 patients (male and female) with CVD who were admitted at the King Abdulaziz university hospital, Jeddah, Saudi Arabia. The biochemical parameters were evaluated using an automated chemistry analyzer, and inflammatory markers were measured using specific enzyme-linked immunosorbent assay (ELISA) kits. For genotypic analysis, Sanger sequencing was performed. We observed a statistically significant association (p < 0.05) between GG (66.29%), GC (30.34%), and CC (3.37%) genotypes at the - 174G/C (rs1800795) hotspot and neopterin levels. However, the genotypes at the - 572G/C (rs1800796) hotspot did not show any association with age, gender, obesity, diabetes, hypertension, dyslipidemia, smoking, and coronary artery status. In addition, no significant association was observed with biochemical and inflammatory markers, namely fasting blood sugar, glycated hemoglobin A1c, creatinine, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, IL-6, and C-reactive protein. The comparison between different possible genotypic groups and CVD risk factors showed a statistically significant (p < 0.05) association between the male gender and HDL with GG, rs1800795 group vs. GC, rs1800796 group. Similarly, neopterin level was also found to be significantly (p < 0.05) associated with the genotypes GC, rs1800795, and GG, rs1800796. Additionally, the male gender (p < 0.01), age (p < 0.05), serum creatinine (p < 0.001), and neopterin (p < 0.05) were found to be significantly associated with GG, rs1800795 + GG, rs1800796, GC, rs1800795 + GC, and rs1800796 GC.

CONCLUSION

The direct association of neopterin level with IL-6 promoter polymorphism at - 174G/C (rs1800795) hotspot indicated the role of inflammation in CVD pathogenesis in the Saudi population.

Association of interleukin 6 -174 G/C polymorphism with coronary artery disease and circulating IL-6 levels: a systematic review and meta-analysis

INTRODUCTION

Circulating IL-6 levels and at least one polymorphic form of IL6 gene (IL6 -174 G/C, rs1800795) have been shown to be independently associated with coronary artery disease (CAD) by several investigators. Despite more than 12 published meta-analyses on this subject, association of -174 G/C with CAD, especially amongst distinct ancestral population groups remain unclear. We, therefore, conducted a systematic review and an updated meta-analysis to comprehensively ascertain the association of IL6 -174 G/C with CAD and circulating IL-6 levels.

MATERIALS AND METHODS

Relevant case-control/cohort studies investigating association of -174 G/C with CAD and circulating IL-6 levels were identified following a comprehensive online search. Association status for CAD was determined for the pooled sample, as well as separately for major ancestral subgroups. Association status for circulating IL-6 levels was assessed for the pooled sample, as well as separately for CAD cases and CAD free controls. Study-level odds ratios (OR) and 95% confidence intervals (CI) were pooled using random/fixed-effects model.

RESULTS

Quantitative synthesis for the CAD endpoint was performed using 55 separate qualifying studies with a collective sample size of 51,213 (19,160 cases/32,053 controls). Pooled association of -174 G/C with CAD was found to be statistically significant through dominant (OR 1.15; 95% CI 1.05-1.25, p = 0.002) as well as allelic genetic model comparisons (OR 1.13, 95% CI 1.06-1.21, p = 0.0003). This effect was largely driven by Asian and Asian Indian ancestral subgroups, which also showed significant association with CAD in both genetic model comparisons (OR range 1.29-1.53, p value range ≤ 0.02). Other ancestral subgroups failed to show any meaningful association. Circulating IL-6 levels were found to be significantly higher amongst the 'C' allele carriers in the pooled sample (Standard mean difference, SMD 0.11, 95% CI 0.01-0.22 pg/ml, p = 0.009) as well as in the CAD free control subgroup (SMD 0.10, 95% CI 0.02-0.17 pg/ml, p = 0.009), though not in the CAD case subgroup (SMD 0.17, 95% CI = - 0.02 to 0.37, p = 0.12).

CONCLUSIONS

The present systematic review and meta-analysis demonstrate an overall association between IL6 -174 G/C polymorphism and CAD, which seems to be mainly driven by Asian and Asian Indian ancestral subgroups. Upregulation of plasma IL-6 levels in the 'C' allele carriers seems to be at least partly responsible for this observed association. This warrants further investigations with large, structured case-control studies especially amongst Asian and Asian Indian ancestral groups.

Genotyping of interleukins-18 promoters and their correlation with coronary artery stenosis in Saudi population

BACKGROUND

Complex coronary atherosclerotic lesions often lead to coronary occlusion, clinically represented as a single-vessel disease (SVD) and multivessel disease (MVD). These occlusions could hinder the blood flow in coronary arteries that affects appropriate management of the CVD. The current study intended to genotype interleukin (IL)-18 promoter's hotspots (rs187238, rs1946518, and rs1946519) and their possible association with coronary artery stenosis.

MATERIAL AND METHODS

The IL-18 promoter genotyping was performed by the Sanger method along with the examination of biochemical parameters in 125 study subjects categorized into three groups, viz. controls, SVD and MVD.

RESULTS

The current study observed a significant association of diabetes, hypertension, and dyslipidemia between the studied group's viz. healthy controls, SVD, and MVD. Fasting blood sugar and glycosylated hemoglobin (HBA1C) were also significantly enhanced from 4.82 vs. 8.01 and 4.33 vs. 8.27, in SVD, and MVD respectively. Despite the visible differences in the pattern of genotypic and allelic expressions, the current study did not show any statistically significant correlation with IL-18 promoter polymorphism at its hotspots with controls, SVD, and MVD subjects. The only exception of the above results was the distribution of allelic frequency at the rs1946519 hotspot, where a significant change (P < 0.05) was observed.

CONCLUSION

This study is of additional value to our previous reports, revealing the pattern of genotypes and allelic frequency of IL-18 promoters in a small cohort of Saudi ethnicity. Further investigations on larger sample size are recommended to envisage the presence of functional mutations in the IL-18 gene that could establish or rule out the possible association of IL-18 polymorphism with SVD and MVD.

Polymorphisms of Pro-Inflammatory IL-6 and IL-1β Cytokines in Ascending Aortic Aneurysms as Genetic Modifiers and Predictive and Prognostic Biomarkers

Background: Previous studies have demonstrated that polymorphisms involved in immune genes can affect the risk, pathogenesis, and outcome of thoracic ascending aortic aneurysms (TAAA). Here, we explored the potential associations of five functional promoter polymorphisms in interleukin-6 (IL-6), IL-1B, IL-1A, IL-18, and Tumor necrosis factor (TNF)A genes with TAAA. Methods: 144 TAAA patients and 150 age/gender matched controls were typed using KASPar assays. Effects on telomere length and levels of TAAA related histopathological and serological markers were analyzed. Results: Significant associations with TAAA risk were obtained for IL-6 rs1800795G>C and IL-1B rs16944C>T SNPs. In addition, the combined rs1800795C/rs16944T genotype showed a synergic effect on TAAA pathogenesis and outcome. The combined rs1800795C/rs16944T genotype was significantly associated with: (a) higher serum levels of both cytokines and MMP-9 and -2; (b) a significant CD3+CD4+CD8+ CD68+CD20+ cell infiltration in aorta aneurysm tissues; (c) a significant shorter telomere length and alterations in telomerase activity. Finally, it significantly correlated with TAAA aorta tissue alterations, including elastic fragmentation, medial cell apoptosis, cystic medial changes, and MMP-9 levels. Conclusions: the combined rs1800795C/rs16944T genotype appears to modulate TAAA risk, pathogenesis, and outcome, and consequently can represent a potential predictive and prognostic TAAA biomarker for individual management, implementation of innovative treatments, and selection of the more proper surgical timing and approaches.

Identification of novel cardiovascular disease associated metabolites using untargeted metabolomics

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality around the world. Early diagnosis of CVD could provide the opportunity for sensible management and better clinical outcome along with the prevention of further progression of the disease. In the current study, we used an untargeted metabolomic approach to identify possible metabolite(s) that associate well with the CVD and could serve either as therapeutic target or disease-associated metabolite. We identified 26 rationally adjusted unique metabolites that were differentially present in the serum of CVD patients compared with healthy individuals, among them 15 were found to be statistically significant. Out of these metabolites, we identified some novel metabolites like UDP-l-rhamnose and N1-acetylspermidine that have not been reported to be linked with CVD directly. Further, we also found that some metabolites like ethanolamide, solanidine, dimethylarginine, N-acetyl-l-tyrosine, can act as a discriminator of CVD. Metabolites integrating pathway enrichment analysis showed enrichment of various important metabolic pathways like histidine metabolism, methyl histidine metabolism, carnitine synthesis, along with arginine and proline metabolism in CVD patients. Our study provides a great opportunity to understand the pathophysiological role and impact of the identified unique metabolites and can be extrapolated as specific CVD specific metabolites.

The effect of polymorphisms (174G> C and 572C> G) on the Interleukin-6 gene in coronary artery disease: a systematic review and meta-analysis

Background

Coronary Artery Disease (CAD) is caused by the blockage of the coronary arteries. it is argued that there has an association between the Interleukin-6 gene and the occurrence of atherosclerosis, coronary artery disease, Due to the short half-life and high variability of Interleukin-6 (IL-6), limited studies have been performed on the association of serum levels of interleukin-6 with coronary artery disease. The aim of this study is to investigate the relationship between IL-6 gene polymorphisms and coronary artery disease.

Methods

This study was conducted as a meta-analysis of selected articles with no lower time limit and upto March 2020. Articles related to the subject were obtained by searching several data sources,such as the SID, IranDoc, Scopus, Embase, Web of Science (ISI), PubMed, Science Direct, and Google Scholar databases. The heterogeneity of the studies was assessed using the I² index in the Comprehensive Meta-Analysis software.

Results

The GG genotype of the IL-6174 G> C polymorphism with a 0.8 odds ratio tended to reduce the risk of CAD by 20%. The odds ratio of CAD in CG and GG genotypes were found to be 1.16 and 1.48 times respectively, indicating the increasing effect of these two genotypes. In the IL-6-572 C>G polymorphism, CG and GG genotypes increased the risk of CAD by 1.21 and 1.27 times respectively, and the CC genotype tended to reduce the risk of CAD by 15%, considering the odds ratio of 0.85.

Conclusion

This study showed a relationship between IL-6174G> C and Interleukin-6 (IL-6) 572 C>G genes and coronary artery disease. Moreover, the protective effects of GG genotype in IL-6 gene 174 G> C and CC genotype in IL-6 gene 572 C>G gene were reported. The study also confirmed that the CG and CC genotypes of the G>C IL-6174 gene have an increasing effect on coronary artery disease. Moreover, CG and GG genotypes in the IL-6 gene 572 C>G increased the risk of developing CAD. It should be noted that the increased risk of developing CAD was limited to meta-analytic studies in reported literatures.

Systematic review and meta-analysis of association of polymorphisms in inflammatory cytokine genes with coronary artery disease

BACKGROUND

It has comprehensively been acknowledged that a genetic contribution, especially in immune inflammatory players, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, are critically involved in the pathophysiology of coronary artery disease (CAD). This meta-analysis study aimed to reach a conclusive understanding of the role of genetic polymorphisms, including IL6 gene C572G (rs1800796) and G174C (rs1800795) as well as TNFA gene G238A (rs361525) and G308A (rs1800629) in susceptibility to CAD.

METHODS

Two major databases, namely MEDLINE and Scopus, were searched to find the studies surveying the mentioned polymorphisms and CAD susceptibility up to July 2020. Association comparison between the polymorphisms and CAD susceptibility were assessed using pooled odds ratio (OR) and their corresponding 95% confidence interval (CI).

RESULTS

This meta-analysis study was conducted on 69 papers (73 population studies), comprising 5062 patients and 8446 controls for IL6 gene rs1800796 (17 studies), 13801 patients and 16215 controls for IL6 gene rs1800795 (38 studies), 1439 patients and 2850 controls for TNFA gene rs361525 (5 studies), and 5051 patients and 3958 controls for TNFA gene rs1800629 (13 studies), according to inclusion and exclusion criteria. There were statistically positive association between all genetic comparisons of IL6 gene rs1800795 polymorphism and the CAD risk. Moreover, the recessive model (CC vs. CG + GG) in IL6 gene rs1800796 polymorphism had marginally significant association with decreased risk of CAD. None of the TNFA gene polymorphisms were associated with CAD risk.

CONCLUSIONS

The meta-analysis revealed the positive association of IL6 gene rs1800795 polymorphism in susceptibility to CAD.

The IL-6 rs1800795 and rs1800796 polymorphisms are associated with coronary artery disease risk

Studies examining the associations between the interleukin‐6 (IL‐6) rs1800795 and rs1800796 gene polymorphisms and risk of coronary artery disease (CAD) remain controversial. Our aim was to evaluate the accurately determine role of these two polymorphisms in CAD risk. PubMed, Embase, VIP, Wan fang and China National Knowledge Infrastructure databases were searched. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The trial sequential analysis (TSA) was conducted, and bioinformatics tools were employed. A total of thirty‐seven articles were obtained. For the IL‐6 rs1800795 polymorphism, 9411 CAD patients and 3161 controls were included, 4720 patients with CAD, and 5000 controls were included for the IL‐6 rs1800796 polymorphism. In the pooled analysis, significant associations were only observed for the rs1800796 polymorphism (allelic: OR [95%CI] = 1.28 [1.13, 1.44], dominant: OR [95%CI] = 1.35 [1.17, 1.57], recessive: OR [95%CI] = 1.35 [1.18, 1.55], heterozygote: OR [95%CI] = 1.26 [1.15, 1.37], homozygote: OR [95%CI] = 1.62 [1.23, 2.13]). Significant associations were detected in the Asian and Mongoloid populations and ‘more than 500’ subgroup for the rs1800795 polymorphism. TSA confirmed the true‐positive results for the rs1800796 polymorphism. The bioinformatics analysis showed that the two polymorphisms played important roles in the gene transcription. The IL‐6 rs1800796 polymorphism is associated with an increased susceptibility to CAD and is a risk factor for CAD. The IL‐6 rs1800795 polymorphism is associated with an increased risk of CAD in Asians, particularly in Chinese, and a decreased risk of CAD in an African population is remarkably observed.

Interleukin 6 (rs1800795) gene polymorphism is associated with cardiovascular diseases: a meta-analysis of 74 studies with 86,229 subjects

Cardiovascular diseases (CVD) are group of complex and multifactorial pathologies, in which interleukin-6 (IL-6) gene polymorphisms have been associated with several components of the CVD. Thus, in this study, we thoroughly reviewed and meta-analyzed evidence on the association between the IL-6 (rs1800795) gene polymorphism and CVD. We systematically searched in the PubMed, Web of Sciences, and Scopus databases. The analyses were performed using five study groups based on (1) a combined pool of the overall populations, (2) the country of birth, (3) the continent of birth, (4) the diagnosis and (5) both location (country or continent) and diagnosis. The analysis included the allelic, homozygote, heterozygote, dominant and recessive models. The meta-analysis showed that -174G>C (rs1800795) is a risk factor for CVD (allelic: OR=1.06, CI 95%=1.02-1.10. Z p value <0.0001; homozygous: OR=1.11, CI 95%=1.03-1.19, Z p value= 0.002; heterozygous: OR=1.08, CI 95%=1.03-1.21, Z p value= 0.003; dominant: OR= 1.12, CI 95%= 1.07-1.18, Z p value= 0.001) and that this risk increases in the Chinese population. Additionally, we found that carriers of the C allele of 174G>C (rs1800795) polymorphism have an increase in the risk of coronary artery disease under the hereditary models assessed in the study. Using robust data, we found that IL-6 (rs1800795) -174G>C gene polymorphism is associated with CVD risk.

An Evidence-Based Meta-Analysis on the Roles of Functional Interleukin-6 Polymorphisms in Coronary Artery Disease

Recently, the relationship between functional interleukin-6 (IL-6) polymorphisms and coronary artery disease (CAD) was extensively studied, with controversial findings. Therefore, we conducted this meta-analysis to better elucidate the relationship between these polymorphisms and the risk of CAD. A total of 57 case-control studies were finally included. The overall analyses showed that IL-6 -174G>C and -572G>C polymorphisms were significantly associated with the risk of CAD, the C allele of -174G>C (G versus C, odds ratio [OR] = 0.82, confidence interval [95% CI] = 0.75-0.89) and -572G>C polymorphisms (G versus C, OR = 0.82, 95% CI = 0.74-0.92) conferred an increased susceptibility to CAD. Further subgroup analyses yielded similar positive results for -174G>C polymorphism in Asian and Caucasian populations, and for -572G>C polymorphism in Asian and African populations. In conclusion, our findings suggest that IL-6 -174G>C and -572G>C polymorphisms may serve as potential genetic markers of CAD.

Samsum Ant Venom Exerts Anticancer Activity Through Immunomodulation In Vitro and In Vivo

Samsum ant venom (SAV) is a rich repertoire of natural compounds with tremendous pharmacological properties. The present work explores its antineoplastic activity in different cell lines followed by its confirmation in vivo. The cell lines, HepG2, MCF-7, and LoVo showed the differential dose-dependent antineoplastic effect with an increased level of significant cytokines, including Interleukin (IL)-1β, IL-6, and IL-8 and transcription factor, Nuclear factor-kappa B (NF-κB). However, the venom was more effective on HepG2 and MCF-7 cells than LoVo cells. Furthermore, the extract was administered to four groups (n = 8) of rats. Group I was taken as a control without any treatment, whereas group II received CCl₄ (1 mL/kg) for induction of mild hepatoma. Group III was given 100 μg/kg of SAV twice a week for 1 month. Group IV was pretreated with the CCl₄ (like group II) followed by dosing with SAV (100 μg/kg) for 2 months as per the authors' prestandardized dosing schedule. Intriguingly, the rats of group IV demonstrated significant decrease in key cytokines, IL-1β and IL-6, as well as the transcription factors, including Tumor Necrosis Factor-alpha (TNF-α), NF-κB, and Inhibitor-kappa B (I-κB) as compared with group II. Furthermore, increase in IL-10 and First apoptosis signal (FAS) in the same group confirmed that SAV induces apoptosis at the given dose through immunomodulation leading to enhanced tumor killing in vivo. Hence, SAV has an excellent antineoplastic activity that can be directly used to treat certain types of cancer. Moreover, study of its ingredients can pave ways to design novel anticancer drugs. However, further in-depth investigation is required before its clinical trials.

Study of IL4-590C/T and IL6-174G/C Gene Polymorphisms in Type 2 Diabetic Patients With Chronic Kidney Disease in North Indian Population

To explore the associations between potential functional promoter polymorphisms in pro-inflammatory and anti-inflammatory (IL-4(-590C/T) and IL-6(-174G/C) cytokine genes, and kidney dysfunction in North Indian type 2 diabetic subjects with chronic kidney disease. A total of 150 subjects aged 25-75 year were included in this study. The glomerular filtration rate (GFR) and serum creatinine were estimated. PCR was performed to analyse genotype distribution in IL-4 (-590T/C) and IL-6 (-174G/C) among healthy, type 2 diabetic patients with or without CKD. The genotype distributions were determined by Hardy-Weinberg equilibrium. CKD patients showed lower GFR (59.36 ± 1.33 ml/min/1.73 m² ) and higher serum creatinine (1.93 ± 0.99% mg) level in comparison to diabetic patients without CKD and healthy subjects. Genotypic distribution of the different genotypes among the study groups in IL-4 gene was genotype CC = 30, TC = 12, and TT = 8 in CKD patients. In type 2 diabetic patients without CKD, genotype distribution was CC = 38, TC = 10, and TT = 2. In healthy subjects, distribution of genotype was CC = 35, TC = 14, and TT = 1. The distribution of different genotype among the study groups for IL-6 gene was GG = 27, GC = 20, and CC = 3 in healthy subjects; GG = 28, GC = 19, and CC = 3 in diabetic patients without CKD and GG = 38, GC = 11, and CC = 1 in diabetic patients with CKD. There was no significant difference in the distribution of genotype frequencies between healthy subjects and diabetic patients without CKD but a significant difference was found in diabetic patients with CKD. The functional promoter polymorphisms IL4-590C/T and IL6-174G/C, which affect the IL-4 and IL-6 levels in north Indian subjects, were associated with kidney dysfunction and CKD. J. Cell. Biochem. 118: 1803-1809, 2017. © 2016 Wiley Periodicals, Inc.