Identification of haplotype tag single nucleotide polymorphisms within the receptor for advanced glycation end products gene and their clinical relevance in patients with major trauma

Association of RAGE rs1800624 and rs1800625 gene polymorphisms with predisposition to optic neuritis and optic neuritis together with multiple sclerosis

Optic neuritis (ON) is demyelinating acute inflammatory disease which affects the optic nerve. ON is classified as a typical (demyelinating) or an atypical (idiopathic). Patients often complain having a periocular pain or a visual loss. The main factor causing the optic neuritis is still unknown. It is believed that it might be a combination of genetic and environmental factors. As the optic neuritis is an inflammation disease, the RAGE gene was selected as it is a part of the inflammation process.

AIM

to determine the relation between RAGE rs1800624 and rs1800625 genotypes of patients who have a manifestation of optic neuritis and optic neuritis with multiple sclerosis together in Lithuanian population and visual acuity recovery.

OBJECTIVES

patients with optic neuritis and healthy controls individuals were examined. Genotyping was carried out by using the instrument of real-time polymerase chain reaction called StepOnePlus (AppliedBiosystems). Statistical analysis was performed using IBM SPSS Statistics 20.0 software and free PLINK software (version 1.07).

RESULTS

Results indicate that rs1800624 polymorphism is not statistically significant in optic neuritis manifestation (p = .392), while rs1800625 GG genotype is associated with 7.5-fold increased odds of ON development under the codominant model (OR = 7.5; 95% CI:1.796-31.313; p = .006) and with 6.9-fold increased odds under the recessive model OR = 6.862; 95% CI:1.665-28.288; p = .008); and each allele G is associated with 1.9-fold increased odds of ON development under the additive model (OR = 1.879; 95% CI:1.149-3.072; p = .012). The haplotype containing A-G alleles in rs1800624 and rs1800625 was statistically significantly associated with increased risk for ON development (χ2 = 13.23; p < .001). Both polymorphisms do not have statistically significant importance in relation to visual acuity recovery.

CONCLUSIONS

RAGE rs1800625 AA genotype decreases the risk of optic neuritis. The single nucleotide polymorphisms RAGE rs1800624 and rs1800625 do not have a statistically significant importance in relation with visual acuity recovery.

Effects of S100B neutralization on the long-term cognitive impairment and neuroinflammatory response in an animal model of sepsis

The nervous system is one of the first systems to be affected during sepsis. Sepsis not only has a high risk of mortality, but could also lead to cerebral dysfunction and cognitive impairment in long-term survival patients. The receptor for advanced glycation end products (RAGE) can interact with several ligands, and its activation triggers a series of cell signaling events, resulting in the hyperinflammatory condition related to sepsis. Recent studies show that elevated levels of S100B (RAGE ligand) are associated with the pathophysiology of neurodegenerative disorders. They also participate in inflammatory brain diseases and may lead to an increased activation of microglia and astrocytes, leading to neuronal death. This study aimed to determine the effect of S100B inhibition on the neuroinflammatory response in sepsis. Sepsis was induced in Wistar rats by cecal ligation and perforation (CLP). There were three groups: Sham, CLP, and CLP +10 μg/kg of monoclonal antibody (Anti-S100B) administered intracerebroventricularly. The animals were killed 30 days after sepsis following behavioral evaluation by open field, novel object recognition, and splash test. The hippocampus, prefrontal cortex, and amydgala were used for the determination of S100B and RAGE proteins by western blotting and for the evaluation of cytokine levels and verification of the number of microglial cells by immunohistochemistry. On day 30, both the Sham and CLP + anti-S100B groups were capable of recovering the habitual memory in the open field task. Regarding novel object recognition, Sham and CLP + anti-S100B groups increased the recognition index during the test session in comparison to the training session. There was a significant increase in the time of grooming in CLP + anti-S100B in comparison to the CLP group. There was a modulation of cytokine levels and immunohistochemistry showed that the CLP + anti-S100B group had a decrease in the number of microglial cells only in the hippocampus. These results helped to understand the role of S100B protein in the pathophysiology of sepsis-associated encephalopathy and could be helpful to further experimental studies regarding this subject.

Clinical relevance of single nucleotide polymorphisms in the CXCL1 and CXCL12 genes in patients with major trauma

BACKGROUND

Genetic backgrounds have been recognized as significant determinants of susceptibility to sepsis. CXC chemokines play a significant role in innate immunity against infectious diseases. Genetic polymorphisms of CXC chemokine genes have been widely studied in inflammatory and infectious diseases but not in sepsis. Thus, we aimed to investigate the clinical relevance of CXC chemokine gene polymorphisms and susceptibility to sepsis in a traumatically injured population.

METHODS

Thirteen tag single nucleotide polymorphisms were selected from CXC chemokine genes using a multimarker tagging algorithm in the Tagger software. Three independent cohorts of injured patients (n = 1700) were prospectively recruited. Selected single nucleotide polymorphisms were genotyped using an improved multiplex ligation detection reaction method. Cytokine production in lipopolysaccharide-stimulated whole blood was measured using an enzyme-linked immunosorbent assay.

RESULTS

Among the 13 tag single nucleotide polymorphisms, four single nucleotide polymorphisms (rs1429638, rs266087, rs2297630, and rs2839693) were significantly associated with the susceptibility to sepsis, and three (rs3117604, rs1429638, and rs4074) were significantly associated with an increased multiple organ dysfunction score in the derivation cohort. However, only the clinical relevance of rs1429638 and rs266087 was confirmed in the validation cohorts. In addition, rs2297630 was significantly associated with interleukin 6 production.

CONCLUSION

The rs1429638 polymorphism in the CXCL1 gene and the rs2297630 polymorphism in the CXCL12 gene were associated with altered susceptibility to sepsis and might be used as important genetic markers to assess the risks of sepsis in trauma patients.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level II.

Pathological Implications of Receptor for Advanced Glycation End-Product (AGER) Gene Polymorphism

The receptor for advanced glycation end-products (RAGE) is a cell surface transmembrane multiligand receptor, encoded by the AGER gene. RAGE presents many transcripts, is expressed mainly in the lung, and involves multiple pathways (such as NFκB, Akt, p38, and MAP kinases) that initiate and perpetuate an unfavorable proinflammatory state. Due to these numerous functional activities, RAGE is implicated in multiple diseases. AGER is a highly polymorphic gene, with polymorphisms or SNP (single-nucleotide polymorphism) that could be responsible or co-responsible for disease development. This review was designed to shed light on the pathological implications of AGER polymorphisms. Five polymorphisms are described: rs2070600, rs1800624, rs1800625, rs184003, and a 63 bp deletion. The rs2070600 SNP may be associated with the development of human autoimmune disease, diabetes complications, cancer, and lung diseases such as chronic obstructive pulmonary disease and acute respiratory distress syndrome. The rs1800624 SNP involves AGER gene regulation and may be related to reduced risk of heart disease, cancer, Crohn's disease, and type 1 diabetes complications. The rs1800625 SNP may be associated with the development of diabetic retinopathy, cancer, and lupus but may be protective against cardiovascular risk. The rs184003 SNP seems related to coronary artery disease, breast cancer, and diabetes. The 63 bp deletion may be associated with reduced survival from heart diseases during diabetic nephropathy. Here, these potential associations between AGER polymorphisms and the development of diseases are discussed, as there have been conflicting findings on the pathological impact of AGER SNPs in the literature. These contradictory results might be explained by distinct AGER SNP frequencies depending on ethnicity.

AGER rs2070600 polymorphism elevates neutrophil-lymphocyte ratio and mortality in metastatic lung adenocarcinoma

Background

The receptor for advanced glycation end-product (RAGE) is a multi-ligand receptor involved in inflammation. In the gene encoding RAGE (AGER), there are three well-known polymorphisms; rs2070600, rs1800624, and rs1800625, which potentially increase the risk of lung cancer. Remarkably, AGER rs2070600 polymorphism, which increases ligand-binding affinity, is a potential prognostic factor in non-small cell lung cancer, but the underlying mechanism is unclear. The neutrophil-lymphocyte ratio (NLR) reflects tumor-associated systemic inflammatory conditions; high ratios are associated with poor prognosis in multiple cancers. Additionally, some humoral factors via RAGE-signaling are associated with elevated NLR in cancer patients.

Objectives

Associations of AGER polymorphisms with disease susceptibility, prognosis, and NLR were investigated in Japanese patients with lung adenocarcinoma.

Methods

We included 189 patients with lung adenocarcinoma, 96 of which had distant metastases, and 303 healthy controls. The correlation between AGER polymorphisms (rs2070600, rs1800624, rs1800625) and disease susceptibility and factors elevating the mortality and NLR in patients with metastases were evaluated.

Results

Only the minor allele of rs2070600 was associated with a higher NLR (β = 0.209, p = 0.043) and a poor prognosis (Hazard ratio = 2.06, 95% Confidence interval = 1.09-3.77, p = 0.028) in patients with metastatic disease, independently of background characteristics, including EGFR mutation status. All three polymorphisms were not associated with the risk of lung adenocarcinoma.

Conclusions

The AGER rs2070600 polymorphism was independently associated with systemic inflammation and poor prognosis in patients with metastatic lung adenocarcinoma.

Association of Polymorphisms of the Receptor for Advanced Glycation Endproducts Gene with Schizophrenia in a Han Chinese Population

Receptor for Advanced Glycation Endproducts (RAGE) is a member of the immunoglobulin superfamily that binds diverse ligands involved in the development of inflammatory damage and diverse chronic diseases including schizophrenia. Here, three single-nucleotide polymorphisms (SNPs) (G82S, -374T/A, and -429T/C) in the RAGE gene were genotyped in 923 patients with schizophrenia and 874 healthy-matched controls in a Han Chinese population using the SNaPshot technique. Additionally, we investigated the association among aforementioned SNPs with the clinical psychotic symptoms of the patients and neurocognitive function. Our study demonstrated that the frequencies of the TC + CC genotypes and the C allele in the -429T/C polymorphism were significantly lower in the patients compared with the controls (p = 0.031 and p = 0.034, resp.). However, the significant effect disappeared when using Bonferroni correction (p = 0.093 and p = 0.102, resp.). And there were no significant differences in the genotype and allele frequencies between the patients and the controls for G82S and -374T/A polymorphisms. Additionally, the -429T/C C allele carriers had marginally higher Symbol coding scores than the subjects with the TT genotypes [p = 0.031 and p (corr) = 0.093]. Our data indicate that the RAGE -429T/C polymorphism may be associated with the susceptibility of schizophrenia.

The promoter polymorphisms of receptor for advanced glycation end products were associated with the susceptibility and progression of sepsis

Receptor for advanced glycation end products (RAGE) is considered a major pattern recognition receptor, which plays an important role in the development of sepsis. Increasing evidence showed an association between RAGE polymorphisms and the susceptibility to several inflammatory-related diseases. However, little is known about the clinical relationship between RAGE polymorphisms and sepsis. In this study, we analyzed the association of sepsis with three functional RAGE gene polymorphisms (rs1800624, rs1800625 and rs2070600) in a Chinese Han population (372 sepsis cases and 400 healthy controls). Significant differences were observed in the rs1800624 and rs1800625 genotype/allele distributions between the sepsis and controls, but no significant difference was observed in the rs2070600 genotype/allele. Moreover, our results also revealed a significant difference in the genotype/allele frequencies of the rs1800624 and rs1800625 polymorphisms between the sepsis and severe sepsis subtypes, the rs1800624 TT or rs1800625 TT genotype carriers exhibited a significant increase in RAGE mRNA, sRAGE, TNF-α and IL-6 expression compared with the rs1800624 AT/AA or rs1800625 CT/CC carriers in sepsis patients. Overall, this study might provide valuable clinical evidence between the RAGE gene polymorphisms and the risk or the development of sepsis.

Rs1800625 in the receptor for advanced glycation end products gene predisposes to sepsis and multiple organ dysfunction syndrome in patients with major trauma

Introduction

The receptor for advanced glycation end products (RAGE) is a transmembrane receptor of the immunoglobulin superfamily, it plays pivotal roles in the pathogenesis of sepsis in several ways. Our previous study showed that rs1800625 (−429T/C) revealed a strong clinical relevance with sepsis morbidity rate and multiple organ dysfunction syndrome (MODS) in patients with major trauma. In this study, we enlarged the sample size, added two validation populations and examined the expression of RAGE on the surface of peripheral leukocytes to ex vivo lipopolysaccharide (LPS) stimulation in subjects with different genotypes.

Methods

Rs1800625 was genotyped using pyrosequencing in 837 Chinese Han patients with major trauma in Chongqing. We then validated the clinical relevance in 340 Zhejiang and 347 Yunnan patients. The expression of RAGE on the surface of peripheral blood mononuclear cells was measured by flow cytometric analysis.

Results

The results indicated that rs1800625 was significantly associated with sepsis morbidity rate and MODS in patients with major trauma in the Chongqing, Zhejiang and Yunnan districts. Patients with CC genotype had lower sepsis morbidity rate and MODS after major trauma. Furthermore, patients with CC genotype had significantly higher RAGE expression (P = 0.009).

Conclusions

The rs1800625 polymorphism is a functional single nucleotide polymorphism and confers host susceptibility to sepsis and MODS in patients with major trauma.

The functional polymorphisms of miR-146a are associated with susceptibility to severe sepsis in the Chinese population

MicroRNA-146a (miR-146a) acts as a pivotal regulatory molecule in immune response and various diseases, such as carcinoma and autoimmune diseases. Growing evidences have demonstrated the association of miR-146a gene single-nucleotide polymorphisms (SNPs) with risk of several diseases, but no genetic relevance studies of miR-146a gene polymorphisms to sepsis have been reported by now. Our study has analyzed the association of sepsis with two functional miR-146a gene SNPs rs2910164 G/C and rs57095329 A/G in a Chinese Han population (226 sepsis cases; 206 healthy controls). Our results indicated a higher prevalence of the miR-146a gene SNP rs2910164 C allele and CC genotype in patients with severe sepsis (rs2910164G versus rs2910164C: P = 0.0029, odds ratio (OR) = 1.664; GG+GC versus CC: P = 0.0045, OR = 1.947). Neither the genotype nor the allele in rs57095329 showed significant differences between the septic cases and the controls (P = 0.5901 and 0.3580, resp.), and no significant difference was observed in the subgroups. In addition, we confirmed that the two SNPs rs2910164 and rs57095329 could functionally affect the miR-146a expression levels and the reduction of miR146a was accompanied with the upregulation of the expression levels of TRAF-6 and IRAK-1 in severe sepsis patients. This present study might provide valuable clinical evidence that miR-146a gene polymorphism rs2910164 is associated with the risk of severe sepsis.