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

Mammalian Diaphanous1 signalling in neurovascular complications of diabetes

Over the past few decades, diabetes gradually has become one of the top non-communicable disorders, affecting 476.0 million in 2017 and is predicted to reach 570.9 million people in 2025. It is estimated that 70 to 100% of all diabetic patients will develop some if not all, diabetic complications over the course of the disease. Despite different symptoms, mechanisms underlying the development of diabetic complications are similar, likely stemming from deficits in both neuronal and vascular components supplying hyperglycaemia-susceptible tissues and organs. Diaph1, protein diaphanous homolog 1, although mainly known for its regulatory role in structural modification of actin and related cytoskeleton proteins, in recent years attracted research attention as a cytoplasmic partner of the receptor of advanced glycation end-products (RAGE) a signal transduction receptor, whose activation triggers an increase in proinflammatory molecules, oxidative stressors and cytokines in diabetes and its related complications. Both Diaph1 and RAGE are also a part of the RhoA signalling cascade, playing a significant role in the development of neurovascular disturbances underlying diabetes-related complications. In this review, based on the existing knowledge as well as compelling findings from our past and present studies, we address the role of Diaph1 signalling in metabolic stress and neurovascular degeneration in diabetic complications. In light of the most recent developments in biochemical, genomic and transcriptomic research, we describe current theories on the aetiology of diabetes complications, highlighting the function of the Diaph1 signalling system and its role in diabetes pathophysiology.

RAGE engagement by SARS-CoV-2 enables monocyte infection and underlies COVID-19 severity

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has fueled the COVID-19 pandemic with its enduring medical and socioeconomic challenges because of subsequent waves and long-term consequences of great concern. Here, we chart the molecular basis of COVID-19 pathogenesis by analyzing patients' immune responses at single-cell resolution across disease course and severity. This approach confirms cell subpopulation-specific dysregulation in COVID-19 across disease course and severity and identifies a severity-associated activation of the receptor for advanced glycation endproducts (RAGE) pathway in monocytes. In vitro THP1-based experiments indicate that monocytes bind the SARS-CoV-2 S1-receptor binding domain (RBD) via RAGE, pointing to RAGE-Spike interaction enabling monocyte infection. Thus, our results demonstrate that RAGE is a functional receptor of SARS-CoV-2 contributing to COVID-19 severity.

Polymorphisms and Gene-Gene Interaction in AGER/IL6 Pathway Might Be Associated with Diabetic Ischemic Heart Disease

Background: Although the genetic susceptibility to diabetes and ischemic heart disease (IHD) has been well demonstrated, studies aimed at exploring gene variations associated with diabetic IHD are still limited; Methods: Our study included 204 IHD cases who had been diagnosed with diabetes before the diagnosis of IHD and 882 healthy controls. Logistic regression was used to find the association of candidate SNPs and polygenic risk score (PRS) with diabetic IHD. The diagnostic accuracy was represented with AUC. Generalized multifactor dimensionality reduction (GMDR) was used to illustrate gene-gene interactions; Results: For IL6R rs4845625, the CT and TT genotypes were associated with a lower risk of diabetic IHD than the CC genotype (OR = 0.619, p = 0.033; OR = 0.542, p = 0.025, respectively). Haplotypes in the AGER gene (rs184003-rs1035798-rs2070600-rs1800624) and IL6R gene (rs7529229-rs4845625-rs4129267-rs7514452-rs4072391) were both significantly associated with diabetic IHD. PRS was associated with the disease (OR = 1.100, p = 0.005) after adjusting for covariates, and the AUC were 0.763 (p < 0.001). The GMDR analysis suggested that rs184003 and rs4845625 were the best interaction model after permutation testing (p = 0.001) with a cross-validation consistency of 10/10; Conclusions: SNPs and haplotypes in the AGER and IL6R genes and the interaction of rs184003 and rs4845625 were significantly associated with diabetic IHD.

The importance of BDNF and RAGE in diabetes-induced dementia

Diabetes-induced dementia is an emerging neurodisorder all over the world. The prevalence rates of dementia and diabetes have been gradually increasing worldwide. Diabetes has been known to lead to oxidative stress, inflammation aggravation, and hyperglycemia conditions in the brain. Various diabetic implications cause the lower secretion of brain-derived neurotrophic factor (BDNF) and the increase of receptor for advanced glycation end products (RAGE), ultimately leading to both cerebrovascular dysfunction and cognitive decline. Here, we summarized the significant evidences highlighting the specific mechanisms between BDNF and RAGE and cerebrovascular dysfunction and memory function and how these relate to diabetes-induced dementia. Especially, we review that the association between BDFN and RAGE in neuroinflammation, the reduction of long-term potentiation, and the vascular implications in brain.

Receptor for advanced glycation end products gene polymorphisms in cardiac syndrome X

Endothelial and microvascular dysfunction serve important roles in the formation and pathogenesis of cardiac syndrome X (CSX). Expression of receptor for advanced glycation end products (RAGE) is suggested to be increased in several conditions, including diabetes, inflammation and vascular diseases. In the present study, RAGE gene polymorphisms in patients with CSX and healthy controls were investigated. A total of 114 patients, diagnosed with CSX using coronary angiography results following complaints of angina and objective ischemia, and 103 healthy controls participated in the study. Whether there was a difference in genotype distributions of RAGE gene -374T/A, -429T/C and Glys82Ser polymorphisms between patients with CSX and healthy controls was investigated. Following DNA isolation from blood samples of the participants, the polymorphic regions were examined by quantitative polymerase chain reaction, and the genotyping results were statistically analyzed. When the genotypic distributions of -374T/A, -429T/C and Gly82Ser polymorphisms were investigated in patients with CSX and healthy controls, no statistically significant differences were identified between the two groups (P>0.05). Likewise, no statistically significant differences were observed in the allelic distributions of all 3 polymorphic regions (P>0.05). To the best of our knowledge, the present study also investigated the association between CSX and RAGE gene polymorphisms for the first time. No statistically significant differences in RAGE gene polymorphisms between the CSX and control groups were observed. We hypothesized that significant results may be obtained by increasing the numbers of patients and healthy controls in future studies.

Relationship between RAGE gene polymorphisms and cardiovascular disease prognosis in the Chinese Han population

Cardiovascular disease (CVD) is the leading cause of death in China. This study aimed to investigate whether RAGE gene polymorphisms are associated with the prognosis of various cardiovascular diseases in the Chinese Han population. This study was conducted from July 2004 to December 2005 and a total of 425 subjects from Guangdong province were enrolled. Genotyping of the three polymorphisms (-429T/C, 1704G/T, and G82S) in the RAGE gene was performed with polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP). Patients were followed for 6.5 years to watch for the development of cardiovascular events and mortality. Subjects with the S mutation of the G82S polymorphism had a significantly higher risk of all-cause mortality and acute myocardial infarction (AMI) than did those with wild-type homozygosity. Logistic regression analysis and Kaplan-Meier analysis all revealed that the G82S polymorphism of the RAGE gene was associated with a significantly increased risk of all-cause mortality and AMI. However, the -429T/C and 1704G/T polymorphisms were not shown to have any effect on prognosis. In conclusion, the G82S variant of the RAGE gene was significantly associated with an increased risk of all-cause mortality and AMI in the Chinese Han population.

Predictive Nomogram of RAGE Genetic Polymorphisms and Metabolic Risk Factors for Myocardial Infarction Risk in a Han Chinese Population

We investigated the association of 4 well-characterized polymorphisms in receptor for the advanced glycation end-product ( RAGE) gene with myocardial infarction (MI) risk and the changes in metabolic risk factors among 717/612 patients/controls, with the aim of constructing a predictive nomogram. The genotype/allele distributions differed significantly between the 2 groups for T-429C ( Pgenotype/allele = .004/.001) and G1704T ( P < .001/.001). T-429C was significantly associated with MI risk, especially under a recessive model (adjusted odds ratio: 2.24, 95% confidence interval: 1.33-3.79, P = .003). For G1704T, significance was detected under additive (1.37; 1.12-1.67; P = .002) and recessive (3.86; 2.27-6.57; P < .001) models. There were significant differences in blood pressure and low-density lipoprotein cholesterol (LDL-C) across T-429C genotypes and in total cholesterol and LDL-C across G1704T genotypes. The overall best multifactor dimensionality reduction model included dyslipidemia, G1704T, and T-429C. Further predictive nomogram on 2 significant polymorphisms, blood pressure and lipids, showed a better predictive capability (concordance index = 0.716, P < .001). Altogether, we identified 2 polymorphisms of RAGE, T-429C and G1704T, which interacted with metabolic risk factors associated with the occurrence of MI. We also constructed a genetic–metabolic nomogram that can better predict MI risk.

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.

The Receptor for Advanced Glycation End Products (RAGE) Is Associated with Persistent Atrial Fibrillation

Objective

Upregulation of the receptor for advanced glycation end products (RAGE) has been proposed as a pathophysiological mechanism underlying the development of atrial fibrillation (AF). We sought to investigate if soluble RAGE levels are associated with AF in Caucasian patients.

Methods

Patients (n = 587) were prospectively recruited and serum levels of soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE) measured. The patients included 527 with sinus rhythm, 32 with persistent AF (duration >7 days, n = 32) and 28 with paroxysmal AF (duration <7 days, n = 28).

Results

Patients with AF were older and had a greater prevalence of heart failure than patients in sinus rhythm. Circulating RAGE levels were higher in patients with persistent AF [median sRAGE 1190 (724–2041) pg/ml and median esRAGE 452 (288–932) pg/ml] compared with paroxysmal AF [sRAGE 799 (583–1033) pg/ml and esRAGE 279 (201–433) pg/ml, p ≤ 0.01] or sinus rhythm [sRAGE 782 (576–1039) pg/ml and esRAGE 289 (192–412) pg/ml, p < 0.001]. In multivariable logistic regression analysis, independent predictors of persistent AF were age, heart failure, sRAGE [odds ratio 1.1 per 100 pg/ml, 95% confidence interval (CI) 1.0–1.1, p = 0.001] and esRAGE [odds ratio 1.3 per 100 pg/ml, 95% CI 1.1–1.4, p < 0.001]. Heart failure and age were the only independent predictors of paroxysmal AF. In AF patients, sRAGE [odds ratio 1.1 per 100 pg/ml, 95% CI 1.1–1.2, p = 0.007] and esRAGE [odds ratio 1.3 per 100 pg/ml, 95% CI 1.0–1.5, p = 0.017] independently predicted persistent compared with paroxysmal AF.

Conclusions

Soluble RAGE is elevated in Caucasian patients with AF, and both sRAGE and esRAGE predict the presence of persistent AF.

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.

An interactive association of advanced glycation end-product receptor gene four common polymorphisms with coronary artery disease in northeastern Han Chinese

Background

Growing evidence indicates that advanced glycation end-product receptor (RAGE) might play a contributory role in the pathogenesis of coronary artery disease (CAD). To shed some light from a genetic perspective, we sought to investigate the interactive association of RAGE gene four common polymorphisms (rs1800625 or T-429C, rs1800624 or T-374A, rs2070600 or Gly82Ser, and rs184003 or G1704A) with the risk of developing CAD in a large northeastern Han Chinese population.

Methodology/Principal Findings

This was a hospital-based case-control study incorporating 1142 patients diagnosed with CAD and 1106 age- and gender-matched controls. All individuals were angiographically confirmed. Risk estimates were expressed as odds ratio (OR) and 95% confidence interval (CI). Overall there were significant differences in the genotype and allele distributions of rs1800625 and rs184003, even after the Bonferroni correction. Logistic regression analyses indicated that rs1800625 and rs184003 were associated with significant risk of CAD under both additive (OR = 1.20 and 1.23; 95% CI: 1.06–1.37 and 1.06–1.42; P = 0.006 and 0.008) and recessive (OR = 1.75 and 2.39; 95% CI: 1.28–2.40 and 1.47–3.87; P<0.001 and <0.001) models after adjusting for confounders. In haplotype analyses, haplotypes C-T-G-G and T-A-G-T (alleles in order of rs1800625, rs1800624, rs2070600 and rs184003), overrepresented in patients, were associated with 52% (95% CI: 1.19–1.87; P = 0.0052) and 63% (95% CI: 1.14–2.34; P = 0.0075) significant increases in adjusted risk for CAD. Further interactive analyses identified an overall best multifactor dimensionality reduction (MDR) model including rs1800625 and rs184003. This model had a maximal testing accuracy of 0.6856 and a cross-validation consistency of 10 out of 10 (P = 0.0016). The validity of this model was substantiated by classical Logistic regression analysis.

Conclusions

Our findings provided strong evidence for the potentially contributory roles of RAGE multiple genetic polymorphisms, especially in the context of locus-to-locus interaction, in the pathogenesis of CAD among northeastern Han Chinese.

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.

RAGE-mediated cell signaling

RAGE (receptor for advanced glycation end products) is a multi-ligand receptor that belongs to the immunoglobulin superfamily of transmembrane proteins. RAGE binds AGEs (advanced glycation end products), HMGB1 (high-mobility group box-1; also designated as amphoterin), members of the S100 protein family, glycosaminoglycans and amyloid β peptides. Recent studies using tools of structural biology have started to unravel common molecular patterns in the diverse set of ligands recognized by RAGE. The distal Ig domain (V1 domain) of RAGE has a positively charged patch, the geometry of which fits to anionic surfaces displayed at least in a proportion of RAGE ligands. Association of RAGE to itself, to HSPGs (heparan sulfate proteoglycans), and to Toll-like receptors in the cell membrane plays a key role in cell signaling initiated by RAGE ligation. Ligation of RAGE activates cell signaling pathways that regulate migration of several cell types. Furthermore, RAGE ligation has profound effects on the transcriptional profile of cells. RAGE signaling has been mainly studied as a pathogenetic factor of several diseases, where acute or chronic inflammation plays a role. Recent studies have suggested a physiological role for RAGE in normal lung function and in neuronal signaling.

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.

Angiotensin-converting enzyme insertion/deletion polymorphism and risk of myocardial infarction in an updated meta-analysis based on 34993 participants

The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of myocardial infarction (MI) has been extensively studied. However, the results were in controversy. This study aimed to explore the association between ACE I/D polymorphism and risk of MI by using a meta-analysis. We retrieved the following databases to indentify eligible studies: Medline, Embase, ISI, VIP, CBM and Wan Fang database. The latest update was 10th May, 2012. Odds ratio and 95% confidence interval (95% CI) were used to present the strength of the association. A total of 40 case-control studies with 34993 participants were included. Overall, D allele of ACE I/D polymorphism was significantly associated with an increased risk of MI in genetic comparison models (OR (95% CI): 1.41 (1.22-1.64) for DD vs. II; 1.11 (1.01-1.21) for ID vs. II; 1.23 (1.10-1.37) for D carriers vs. II; 1.28 (1.15-1.43) for DD vs. I carriers and 1.06 (1.02-1.10) for D carriers vs. I carriers). Subgroup analyses, according to ethnicities and countries of participants also indicated that D allele was significantly associated with an increased risk of MI in Asians (especially for Chinese) and Caucasians (especially for English, French, Germans and Italians) (OR (95% CI) of DD vs. ID+II: 2.11 (1.65-2.70) for Asians and 1.15 (1.05-1.27) for Caucasians). In conclusion, this meta-analysis indicated that D allele of ACE I/D polymorphism was a possible risk factor for MI incidence for both Asians and Caucasians.

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.

RAGE: a new frontier in chronic airways disease

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous inflammatory disorders of the respiratory tract characterized by airflow obstruction. It is now clear that the environmental factors that drive airway pathology in asthma and COPD, including allergens, viruses, ozone and cigarette smoke, activate innate immune receptors known as pattern-recognition receptors, either directly or indirectly by causing the release of endogenous ligands. Thus, there is now intense research activity focused around understanding the mechanisms by which pattern-recognition receptors sustain the airway inflammatory response, and how these mechanisms might be targeted therapeutically. One pattern-recognition receptor that has recently come to attention in chronic airways disease is the receptor for advanced glycation end products (RAGE). RAGE is a member of the immunoglobulin superfamily of cell surface receptors that recognizes pathogen- and host-derived endogenous ligands to initiate the immune response to tissue injury, infection and inflammation. Although the role of RAGE in lung physiology and pathophysiology is not well understood, recent genome-wide association studies have linked RAGE gene polymorphisms with airflow obstruction. In addition, accumulating data from animal and clinical investigations reveal increased expression of RAGE and its ligands, together with reduced expression of soluble RAGE, an endogenous inhibitor of RAGE signalling, in chronic airways disease. In this review, we discuss recent studies of the ligand-RAGE axis in asthma and COPD, highlight important areas for future research and discuss how this axis might potentially be harnessed for therapeutic benefit in these conditions.

The interaction between obesity and RAGE polymorphisms on the risk of knee osteoarthritis in Chinese population

BACKGROUND

The receptor for advanced glycation end products (RAGE) has been reported to relate to osteoarthritis (OA), however, the role of RAGE genetic variants in OA remains unknown.

METHOD

A total of 233 patients with primary knee OA and 255 healthy volunteer were recruited. Three RAGE gene polymorphisms, namely, Gly82Ser (rs2070600). -374T/A (rs1800624) and 429T/C (rs1800625) were genotyped.

RESULTS

Of all three RAGE gene polymorphisms, only the genotype distributions and alleles frequencies of 82G/S polymorphisms significantly differed between knee OA and control subjects. The presence of SS genotype and S allele of 82G/S we significantly higher in knee OA subjects than in controls (34.76% vs. 19.61%, P for trend =0.004; 57.64% vs. 48.59%, P for trend <0.001, respectively). Multivariate logistic regression analysis showed a significantly increased risk for knee OA for the SS genotype compared with the AA genotype (OR= 1.984, 95% CI: 1.238-3.181; P =0.004). The adjusted OR for S allele carriage was significantly higher than G allele carriage (OR=1.440, 95% CI: 1.137-1.8231, P=0.002). Moreover, a significant multiplicative interaction was observed between 82G/S polymorphisms with obesity (Pinteraction=0.028). Taking the non-obese 82GG genotype as references, the OR for OA in non-obese SS carriers was 2.537 (95% CI 1.241-5.189, P=0.001). Notably, the OR in obese GS carriers was 2.304 (95% CI: 1.218-4.357, P=0.009) and in obese SS was 3.392 (95% CI: 1.672-6.885, P=0.001). The -374T/A and -429T/C did not show positive interaction with obesity and smoking status.

CONCLUSION

The AGE 82G/S polymorphisms, in interaction with obesity, may determine the susceptibility of OA in Chinese population.

Receptor for AGE (RAGE): signaling mechanisms in the pathogenesis of diabetes and its complications

The receptor for advanced glycation endproducts (RAGE) was first described as a signal transduction receptor for advanced glycation endproducts (AGEs), the products of nonenzymatic glycation and oxidation of proteins and lipids that accumulate in diabetes and in inflammatory foci. The discovery that RAGE was a receptor for inflammatory S100/calgranulins and high mobility group box 1 (HMGB1) set the stage for linking RAGE to both the consequences and causes of types 1 and 2 diabetes. Recent discoveries regarding the structure of RAGE as well as novel intracellular binding partner interactions advance our understanding of the mechanisms by which RAGE evokes pathological consequences and underscore strategies by which antagonism of RAGE in the clinic may be realized. Finally, recent data tracking RAGE in the clinic suggest that levels of soluble RAGEs and polymorphisms in the gene encoding RAGE may hold promise for the identification of patients who are vulnerable to the complications of diabetes and/or are receptive to therapeutic interventions designed to prevent and reverse the damage inflicted by chronic hyperglycemia, irrespective of its etiology.

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.