Association of RAGE gene polymorphisms with coronary artery disease in the Korean population

G82S RAGE polymorphism influences amyloid-RAGE interactions relevant in Alzheimer's disease pathology

Receptor for advanced glycation end products (RAGE) has been implicated in the pathophysiology of Alzheimers disease(AD) due to its ability to bind amyloid-beta (Aβ42) and mediate inflammatory response. G82S RAGE polymorphism is associated with AD but the molecular mechanism for this association is not understood. Our previous in silico study indicated a higher binding affinity for mutated G82S RAGE, which could be caused due to changes in N linked glycosylation at residue N81. To confirm this hypothesis, in the present study molecular dynamics (MD) simulations were used to simulate the wild type (WT) and G82S glycosylated structures of RAGE to identify the global structural changes and to find the binding efficiency with Aβ42 peptide. Binding pocket analysis of the MD trajectory showed that cavity/binding pocket in mutant G82S glycosylated RAGE variants is more exposed and accessible to external ligands compared to WT RAGE, which can enhance the affinity of RAGE for Aβ. To validate the above concept, an in vitro binding study was carried using SHSY5Y cell line expressing recombinant WT and mutated RAGE variant individually to which HiLyte Fluor labeled Aβ42 was incubated at different concentrations. Saturated binding kinetics method was adopted to determine the Kd values for Aβ42 binding to RAGE. The Kd value for Aβ42- WT and Aβ42-mutant RAGE binding were 92±40 nM (95% CI-52 to 152nM; R2-0.92) and 45±20 nM (95% CI -29 to 64nM; R2-0.93), respectively. The Kd value of <100nM observed for both variants implicates RAGE as a high-affinity receptor for Aβ42 and mutant RAGE has higher affinity compared to WT. The alteration in binding affinity is responsible for activation of the inflammatory pathway as implicated by enhanced expression of TNFα and IL6 in mutant RAGE expressing cell line which gives a mechanistic view for the G82S RAGE association with AD.

Association of RAGE gene Gly82Ser polymorphism with coronary artery disease and ischemic stroke: A systematic review and meta-analysis

BACKGROUND

The receptor for advanced glycosylation end products (RAGE) has been widely linked to diabetic atherosclerosis, but its effects on coronary artery disease (CAD) and ischemic stroke (IS) remain controversial. The Gly82Ser polymorphism is located in the ligand-binding V domain of RAGE, suggesting a possible influence of this variant on RAGE function. The aim of the present study is to clarify the association between the RAGE Gly82Ser polymorphism and susceptibility to CAD and IS.

METHODS

Eligible studies were identified through a comprehensive literature search. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the association of Gly82Ser polymorphism with CAD and IS risk. Fixed- or random-effects model was used depending on the heterogeneity between studies. A funnel plot and Egger linear regression test were applied to assess publication bias. We also performed subgroup analyses to investigate potential sources of heterogeneity.

RESULTS

A total of 16 eligible articles containing 18 studies were analyzed. The pooled analysis indicated that the Gly82Ser polymorphism significantly increased CAD risk in recessive and homozygous genetic models (SS vs GS + GG: OR = 1.34, 95% CI = 1.09-1.64; SS vs GG: OR = 1.38, 95% CI = 1.12-1.71). A significant association between the Gly82Ser polymorphism and IS risk was observed in all tested models except the heterozygous genetic model (GS + SS vs GG: OR = 1.20, 95% CI = 1.04-1.38; SS vs GS + GG: OR = 2.20, 95% CI = 1.74-2.78; SS vs GG: OR = 2.23, 95% CI = 1.72-2.91; S vs G: OR = 1.32, 95% CI = 1.05-1.65). Subgroup analysis suggested an association between CAD and IS risk and the Gly82Ser polymorphism in the Chinese population, but not in the non-Chinese population.

CONCLUSIONS

The current meta-analysis suggests that the RAGE Gly82Ser polymorphism is associated with an increased risk of CAD and IS, especially in the Chinese population. However, better-designed studies with larger sample sizes are needed to validate the results.

Association between the receptor for advanced glycation end products gene polymorphisms and coronary artery disease

Receptor for advanced glycation end products (RAGE) is a cell-surface molecule member of the immunoglobulin superfamily and thought to play a critical role in diabetic atherosclerosis. A growing body of studies has been conducted to determine the extent to which the variants of RAGE gene influence the risk of coronary artery disease (CAD). However, these have reported conflicting results. To investigate this inconsistency, we performed a comprehensive meta-analysis on the associations between the RAGE -374T/A, -429T/C, and Gly82Ser polymorphisms and the risk of CAD. A total of 4,402 cases and 6,081 controls from 17 published case-control studies were included. The overall odds ratio (OR) of CAD was 0.99 (95 % CI 0.87-1.13), 1.06 (95 % CI 0.95-1.18) and 1.12 (95 % CI 0.90-1.39) for -374A, -429C, and the minor S allele of the Gly82Ser polymorphism, respectively. Similarly, no significant results were observed for these polymorphisms using dominant model. However, when stratified by diabetic/non-diabetic status of the CAD patients, we found significant association among Caucasian type two diabetic CAD patients with the -374A allele [OR 1.39, 95 % CI 1.10-1.76, P(Z) = 0.006], while no association was detected between the -374T/A polymorphism and non-diabetic CAD in Caucasians [OR 0.79, 95 % CI 0.58-1.07, P(Z) = 0.13]. In conclusion, this meta-analysis suggested that possession of the -374A allele may be a risk factor in CAD among Caucasian patients with type two diabetes.

Higher serum soluble receptor for advanced glycation end product levels and lower prevalence of metabolic syndrome among Japanese adult men: a cross-sectional study

BACKGROUND

Although several studies showed that decreased soluble receptor for advanced glycation end products (sRAGE) is associated with metabolic syndrome (MetS), inflammation level has not been considered, even though ligand-RAGE interaction induces inflammation. The objective of the study was to determine the association between sRAGE and MetS among Japanese adult in a cross-sectional survey, taking the level of low grade inflammation into consideration.

METHODS

Serum soluble RAGE (sRAGE) were measured in 712 men and 176 women aged 30-83 years with serum C-reactive protein (hsCRP) concentration below 3 mg/L. MetS was defined using the criteria of the American Heart Association Scientific Statements of 2009.

RESULTS

After multivariable adjustment, among men, higher sRAGE levels were associated with lower odds of MetS as well as central obesity and elevated blood pressure. Comparing the extreme tertiles of sRAGE, odds ratios (95% confidence interval) were 0.58 (0.36-0.95; P for trend = 0.001) for MetS; 0.41 (0.25-0.52; P for trend < 0.001) for central obesity; and 0.45 (0.29-0.70; P for trend < 0.001) for elevated blood pressure. Moreover, participants were categorized according to their median hsCRP and sRAGE values. Men in the higher hsCRP/higher sRAGE category had a 40% lower odds ratio for MetS than those in the higher hsCRP/lower sRAGE category (P = 0.031). Among women, there was no association between sRAGE levels and the prevalence of MetS.

CONCLUSIONS

Higher circulating RAGE concentrations were associated with lower prevalence of MetS and its components among Japanese men.

Association of four genetic polymorphisms of AGER and its circulating forms with coronary artery disease: a meta-analysis

Background

Considerable efforts have been devoted to evaluating the association of the receptor for advanced glycation end-products (gene AGER and protein: RAGE) genetic variants to coronary artery disease (CAD); the results, however, are often irreproducible. To generate more information, we sought to explore four common polymorphisms of AGER and its circulating forms associated with the risk of CAD via a meta-analysis.

Methodology/Principal Findings

Articles were identified by searching PubMed, EMBASE, Wanfang and CNKI databases before March 2013. Qualified articles had case-control designs and investigated AGER four polymorphisms (T-429C, T-374A, Gly82Ser, G1704A) or circulating soluble RAGE (sRAGE) or endogenous secretory RAGE (esRAGE) levels associated with CAD. Twenty-seven articles involving 39 independent groups fulfilled the predefined criteria. Overall, no significance was observed for all examined polymorphisms under allelic and dominant models. When restricting groups to CAD patients with diabetes mellitus or renal disease, deviations of risk estimates from the unity were stronger than overall estimates for all polymorphisms except for G1704A due to limited available studies. For example, under dominant model, having -429C allele increased the odds of developing CAD in diabetic patients by 1.22-fold (95% confidence interval (95% CI) 0.99–1.51; P = 0.06; I² = 6.7%) compared with that of overall estimate of 1.15-fold (95% CI: 0.97–1.36; P = 0.111; I² = 18.0%). Circulating sRAGE levels were non-significantly lower in CAD patients than in controls, whereas this reduction was totally and significantly reversed in CAD patients with diabetes mellitus (weighted mean difference: 185.71 pg/ml; 95% CI: 106.82 to 264.61 pg/ml). Circulating esRAGE levels were remarkably lower in CAD patients, as well as in subgroups with or without diabetes mellitus and without renal disease.

Conclusions

Our findings demonstrated that association of AGER genetic polymorphisms with CAD was potentiated in patients with diabetes mellitus or renal disease. Practically, circulating esRAGE might be a powerful negative predictor for the development of CAD.

The immunobiology of the receptor of advanced glycation end-products: trends and challenges

Pattern-recognition receptors have been highly conserved in evolution. They recognize danger signals including both pathogen- and damage-associated molecular patterns, also known as alarmins. Several signaling pathways leading to an inflammatory reaction as part of an effective defensive response, are thus triggered. RAGE, a receptor initially considered for advanced glycation end-products, is also known to be activated by several danger signals, thus functioning as a pattern-recognition receptor. As a new member of this family, attempts to unraveling its functioning show that RAGE activation not only results in innate immune response but also contributes to promote and shape the acquired immune reaction. As reported for other members of the family, RAGE presents many polymorphic variants and additional studies are needed to elucidate its significance in immune response and disease susceptibility. Here we describe recent advances unraveling RAGE functions, as well as its significance and challenges in immunobiology.

Meta-analysis of RAGE gene polymorphism and coronary heart disease risk

Background

Recent data from human and animal studies have shown an upregulated expression of advanced glycosylation end product–specific receptor (RAGE) in human atherosclerotic plaques 1 and in retina, messangial, and aortic vessels, suggesting an important role of RAGE in the pathogenesis of atherothrombotic diseases. In the past few years, the relationship between RAGE polymorphisms (−429T/C, −374T/A, and G82S) and coronary heart disease (CHD) has been reported in various ethnic groups; however, these studies have yielded contradictory results.

Methods

PubMed, ISI web of science, EMBASE and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. Data were abstracted independently by two reviewers. A meta-analysis was performed to examine the association between RAGE polymorphisms and susceptibility to CHD. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

Results

A total of 17 studies including 4343 patients and 5402 controls were involved in this meta-analysis. Overall, no significant results were observed for −429T/C (OR  = 1.01, 95% CI: 0.92–1.12, P  = 0.78), −374T/A (OR  = 1.11, 95% CI: 0.98–1.26, P  = 0.09) and G82S (OR  = 1.12, 95% CI: 0.86–1.45, P  = 0.41) polymorphism. In the stratified analyses according to ethnicity, sample size, CHD endpoint and Hardy-Weinberg status, no evidence of any gene-disease association was obtained.

Conclusions

This meta-analysis demonstrates that there is no association between the RAGE −429T/C, −374T/A and G82S polymorphisms and CHD.

Association study of polymorphisms in the receptor for advanced glycation end-products (RAGE) gene with susceptibility and prognosis of heart failure

BACKGROUND

Functional polymorphisms in the receptor for advanced glycation end-products (RAGE) gene have been implicated in several vascular diseases. However, to date, no study investigated the association of RAGE polymorphisms with heart failure (HF).

OBJECTIVE

In this study we tested the hypothesis that the 63-bp insertion/deletion, the -374T>A (rs1800624) and the -429T>C (rs1800625) polymorphisms in the RAGE gene might be associated with susceptibility to HF and could predict all-cause mortality in Brazilian outpatients with left ventricular systolic dysfunction.

METHODS

A total of 273 consecutive HF patients (196 Caucasian- and 77 African-Brazilians) and 334 healthy blood donors (260 Caucasian- and 74 African-Brazilians) were enrolled in a tertiary care university hospital. Genotyping of RAGE polymorphisms was done by polymerase chain reaction (PCR) or PCR followed by enzyme restriction analysis.

RESULTS

The allele, genotype and haplotype frequencies of -374T>A and -429T>C polymorphisms were not significantly different between HF patients and healthy blood donors in both ethnic groups. However, among African-Brazilians, the frequency of carriership of the del allele was lower in HF patients than in blood donors (2.6% vs 12.2%, respectively, p=0.008). Patients were followed-up for a median of 38 months and the survival analysis did not reveal a consistent association between RAGE polymorphisms and all-cause death in both ethnic groups.

CONCLUSION

The -374T>A and -429T>C polymorphisms in the RAGE gene were not associated with the susceptibility and prognosis of HF. Notwithstanding, the 63-bp ins/del polymorphism might be involved in the susceptibility to HF in African-Brazilians.

Association of AGER gene G82S polymorphism with the severity of coronary artery disease in Chinese Han population

BACKGROUND AND OBJECTIVE

Advanced glycosylation end-product receptor (AGER) plays an important role in the development and progression of atherosclerosis. The G82S polymorphism (rs2070600) is located in the ligand-binding V-domain of AGER suggesting a possible influence of this variant on AGER function. The aim of this study is to evaluate the association of the G82S polymorphism with the severity of coronary artery disease (CAD) in patients with or without type 2 diabetes mellitus (T2DM).

DESIGN AND METHODS

The AGER gene G82S polymorphism was analysed in 270 nondiabetic and 270 type 2 diabetic Chinese Han patients with angiographically proven CAD (luminal stenosis ≥ 50%). The number of diseased vessels and Gensini score were used to determine the severity of CAD. Genotyping for the G82S polymorphism was performed by PCR-RFLP using restriction enzymes AluI.

RESULTS

The frequency of 82S allele was significantly lower in the diabetic CAD patients with multi-vessel disease than in those with single-vessel disease (P = 0·015). When controlled for confounding variables, the 82S allele was associated with decreased risk of multi-vessel disease [P = 0·038, adjusted OR = 0·565 (0·329-0·972)]. The protective effect of the 82S allele against the severity of CAD was not observed in patients with nondiabetic CAD.

CONCLUSIONS

AGER 82S allele showed a protective effect on CAD severity in the presence of T2DM in Chinese Han population.

Association of polymorphisms in the RAGE gene with serum CRP levels and coronary artery disease in the Chinese Han population

The role of an advanced glycation end product/receptor for advanced glycation end product (AGE/RAGE) system in the pathogenesis of coronary artery disease (CAD) is not fully understood. To clarify whether polymorphisms of the RAGE gene were related to CAD, we performed a case-control study in Chinese Han patients. The allele frequencies and genotype distribution combinations of the -429T/C, 1704G/T and G82S polymorphisms of the RAGE gene were compared in 200 cases of hypertension (HT), 155 cases of CAD combined with HT (CAD&HT), 175 cases of CAD and 170 control subjects. Polymerase chain reaction-restriction fragment length polymorphism was used for detection of genotypic variants. The S allele frequency of the G82S polymorphism was higher in the CAD (odds ratio (OR), 2.303, 95% confidence interval (CI) 1.553-3.416; P<0.001, P(corr)<0.003) and CAD&HT (OR, 1.842; 95% CI 1.219-2.785; P<0.003, P(corr)<0.009) groups when compared with the control group. However, the S allele frequency was not significantly different between the CAD and the CAD&HT patient groups (P=0.223), and no statistically significant difference of genotype or allele frequency distributions was observed in the HT group (P>0.05). Meanwhile, serum CRP was significantly associated with the G82S variant. Haplotype-based logistic regression analysis revealed that haplotype G-Ser-T (OR, 1.670; 95% CI, 1.017-2.740; P=0.043), compared with the reference haplotype T-Gly-T, was associated with an increased risk of CAD after adjusting for other risk factors. Further analysis limited to non-diabetic participants exhibited similar significant findings. The haplotype carrying the G82S variant of the RAGE gene was significantly associated with an increased risk of CAD, but not with HT patients. Moreover, a remarkable association of the G82S variant with serum CRP levels implied that the prevalence of RAGE 82S allelic variation might influence susceptibility to CAD by affecting vascular inflammation.

The association between the -374T/A polymorphism of the receptor for advanced glycation endproducts gene and blood pressure and arterial stiffness is modified by glucose metabolism status: the Hoorn and CoDAM studies

OBJECTIVES

Receptor for advanced glycation endproducts (RAGE)-ligand interaction may lead to vascular complications. Genetic variation in RAGE has been shown to alter expression, activity of RAGE or both. We, therefore, investigated whether RAGE single-nucleotide polymorphisms (SNPs) and haplotypes were associated with vascular disease.

METHODS

Nine tag SNPs that cover the common RAGE gene variation were genotyped in 1291 individuals from two Dutch population-based cohort studies, aged 64.5 +/- 8.6 years, with normal glucose metabolism (44%), impaired glucose metabolism (23%) or type 2 diabetes mellitus (33%). We used multiple regression analyses to compare prevalent cardiovascular disease and markers of atherosclerosis, blood pressure and arterial stiffness across genotypes, and examine effect modification by glucose metabolism status.

RESULTS

In unstratified analyses, no consistent associations between RAGE SNPs and prevalent cardiovascular disease and markers of atherosclerosis were found. However, the AA genotype of SNP rs1800624 (-374T/A) was consistently associated with lower SBP [-5.0 mmHg (95% confidence interval -10.4 to 0.3)] and DBP [-4.2 (-7.2 to -1.3)], pulse pressure [-0.8 (-5.0 to 3.4)] as well as with less arterial stiffness [-0.56 SD (-1.04 to -0.09)] in individuals with normal glucose metabolism, but with higher SBP [6.2 (0.9-11.5)], DBP [2.1 (-0.7 to 5.0)] and pulse pressure [4.1 (-0.2 to 8.4)] in individuals with impaired glucose metabolism or type 2 diabetes mellitus (P for interaction <or=0.05 in all analyses). Similar results were found for a haplotype that includes the -374A allele.

CONCLUSION

In individuals with normal glucose metabolism, the -374A allele of the RAGE gene is protectively associated with blood pressure and arterial stiffness, whereas in individuals with impaired glucose metabolism or type 2 diabetes mellitus, it is adversely associated with these variables.

Personalized Medicine in Coronary Artery Disease: Insights From Genomic Research

Prior clinical studies have demonstrated that a family history of coronary artery disease (CAD) is associated with future cardiovascular events. Although there are several Mendelian disorders that are associated with CAD, most common forms of CAD are believed to be multifactorial and the result of many genes with small individual effects. The identification of these genes and their variation would be very helpful for the prediction, prevention, and management of CAD; linkage analysis or candidate gene case-control studies have been largely unsuccessful. On the contrary, recent advances in genomic techniques have generated a large amount of deoxyribonucleic acid (DNA)-based information. The link between CAD and inflammation and biological pathways has been highlighted. In particular, several genome-wide association studies have replicated a novel gene marker on chromosome 9p21. The information gained from genomic studies, in combination with clinical data, is expected to refine personalized approaches to assess risk and guide management for CAD. Genetic risk scores derived from several functional single nucleotide polymorphisms (SNPs) or haplotypes in multiple genes may improve the prediction of CAD. Despite the complexity of CAD genetics, steady progress is expected.

RAGE polymorphisms, renal function and histological finding at 12 months after renal transplantation

OBJECTIVES

Rage (receptor for advanced glycation end products) is involved in pathogenesis of many diseases. The aim of the study was to test whether polymorphisms of RAGE gene are associated with the outcome of kidney transplantation.

DESIGN AND METHODS

Four polymorphisms of the RAGE gene (-429T/C, -374T/A, Gly82Ser and 2184A/G) were assessed in 145 renal transplant recipients and their relationship to histological changes in 12 months protocol kidney graft biopsy and renal function was examined.

RESULTS

Genotype frequencies of each polymorphism corresponded to expected frequencies according to Hardy-Weinberg equilibrium. No differences between allelic and genotype frequencies among patients with normal histological findings, chronic allograft nephropathy and subclinical rejection were observed.

CONCLUSION

This is the first study on polymorphisms of the RAGE gene in patients with the transplanted kidney. No association of RAGE selected gene polymorphisms with 12-months outcome of renal transplants was shown in study.

Gly82Ser polymorphism of the receptor for advanced glycation end products is associated with an increased risk of gastric cancer in a Chinese population

PURPOSE

It has been shown that the expression of the receptor for advanced glycation end products (RAGE) is closely associated with invasion and metastasis in gastric cancer. A Gly82Ser polymorphism in exon 3 of RAGE gene was identified and thought to have an effect on the functions of its protein. Therefore, the goal of the present study was to investigate whether the polymorphism is involved in the development or progression of gastric cancer.

EXPERIMENTAL DESIGN

In the hospital-based case-control study, the RAGE genotypes were determined using PCR-RFLP in 566 individuals (283 gastric cancer patients and 283 age- and sex-matched controls).

RESULTS

The distribution of genotype was significantly different between cases and controls (P = 0.038). Compared with the wild-type 82Gly/Gly carriers, subjects with the variant genotypes (82Gly/Ser and 82Ser/Ser) had a significantly higher risk of gastric cancer (adjusted odds ratio, 1.47; 95% confidence interval, 1.05-2.06). Moreover, the elevated gastric cancer risk was especially evident in younger individuals (ages < or =58 years), nonsmokers, and rural subjects. Further analyses revealed that the variant genotypes were associated with adjacent organ invasion in the subanalysis of gastric cancer patients.

CONCLUSIONS

Our findings indicate that the RAGE Gly82Ser polymorphism may confer not only an increased risk of gastric cancer but also with invasion of gastric cancer in the Chinese population.