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

Microglia aggravate white matter injury via C3/C3aR pathway after experimental subarachnoid hemorrhage

The activation of glial cells is intimately associated with the pathophysiology of neuroinflammation and white matter injury (WMI) during both acute and chronic phases following subarachnoid hemorrhage (SAH). The complement C3a receptor (C3aR) has a dual role in modulating inflammation and contributes to neurodevelopment, neuroplasticity, and neurodegeneration. However, its impact on WMI in the context of SAH remains unclear. In this study, 175 male C57BL/6J mice underwent SAH through endovascular perforation. Oxyhemoglobin (oxy-Hb) was employed to simulate SAH in vitro. A suite of techniques, including immunohistochemistry, transcriptomic sequencing, and a range of molecular biotechnologies, were utilized to evaluate the activation of the C3-C3aR pathway on microglial polarization and WMI. Results revealed that post-SAH abnormal activation of microglia was accompanied by upregulation of complement C3 and C3aR. The inhibition of C3aR decreased abnormal microglial activation, attenuated neuroinflammation, and ameliorated WMI and cognitive deficits following SAH. RNA-Seq indicated that C3aR inhibition downregulated several immune and inflammatory pathways and mitigated cellular injury by reducing p53-induced death domain protein 1 (Pidd1) and Protein kinase RNA-like ER kinase (Perk) expression, two factors mainly function in sensing and responding to cellular stress and endoplasmic reticulum (ER) stress. The deleterious effects of the C3-C3aR axis in the context of SAH may be related to endoplasmic reticulum (ER) stress-dependent cellular injury and inflammasome formation. Agonists of Perk can exacerbate the cellular injury and neuroinflammation, which was attenuated by C3aR inhibition after SAH. Additionally, intranasal administration of C3a during the subacute phase of SAH was found to decrease astrocyte reactivity and alleviate cognitive deficits post-SAH. This research deepens our understanding of the complex pathophysiology of WMI following SAH and underscores the therapeutic potential of C3a treatment in promoting white matter repair and enhancing functional recovery prognosis. These insights pave the way for future clinical application of C3a-based therapies, promising significant benefits in the treatment of SAH and its related complications.

Pharmacological targets of SGLT2 inhibitors on IgA nephropathy and membranous nephropathy: a mendelian randomization study

Introduction

Emerging research suggests that sodium-glucose cotransporter 2 (SGLT2) inhibitors may play a pivotal role in the treatment of primary glomerular diseases. This study was aimed to investigate potential pharmacological targets connecting SGLT2 inhibitors with IgA nephropathy (IgAN) and membranous nephropathy (MN).

Methods

A univariate Mendelian randomization (MR) analysis was conducted using publicly available genome-wide association studies (GWAS) datasets. Co-localization analysis was used to identify potential connections between target genes and IgAN and MN. Then, Comparative Toxicogenomics Database (CTD) was employed to predict diseases associated with these target genes and SGLT2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin). Subsequently, phenotypic scan analyses were applied to explore the causal relationships between the predicted diseases and target genes. Finally, we analyzed the immune signaling pathways involving pharmacological target genes using the Kyoto encyclopedia of genes and genomes (KEGG).

Results

The results of MR analysis revealed that eight drug targets were causally linked to the occurrence of IgAN, while 14 drug targets were linked to MN. In the case of IgAN, LCN2 and AGER emerged as co-localized genes related to the pharmacological agent of dapagliflozin and the occurrence of IgAN. LCN2 was identified as a risk factor, while AGER was exhibited a protective role. KEGG analysis revealed that LCN2 is involved in the interleukin (IL)-17 immune signaling pathway, while AGER is associated with the neutrophil extracellular traps (NETs) signaling immune pathway. No positive co-localization results of the target genes were observed between two other SGLT2 inhibitors (canagliflozin and empagliflozin) and the occurrence of IgAN, nor between the three SGLT2 inhibitors and the occurrence of MN.

Conclusion

Our study provided evidence supporting a causal relationship between specific SGLT2 inhibitors and IgAN. Furthermore, we found that dapagliflozin may act on IgAN through the genes LCN2 and AGER.

The Gly82Ser polymorphism in the receptor for advanced glycation endproducts increases the risk for coronary events in the general population

The receptor for advanced glycation endproducts (RAGE) has pro-inflammatory and pro-atherogenic effects. Low plasma levels of soluble RAGE (sRAGE), a decoy receptor for RAGE ligands, have been associated with increased risk for major adverse coronary events (MACE) in the general population. We performed a genome-wide association study to identify genetic determinants of plasma sRAGE in 4338 individuals from the cardiovascular arm of the Malmö Diet and Cancer study (MDC-CV). Further, we explored the associations between these genetic variants, incident first-time MACE and mortality in 24,640 unrelated individuals of European ancestry from the MDC cohort. The minor alleles of four single nucleotide polymorphisms (SNPs): rs2070600, rs204993, rs116653040, and rs7306778 were independently associated with lower plasma sRAGE. The minor T (vs. C) allele of rs2070600 was associated with increased risk for MACE [HR 1.13 95% CI (1.02-1.25), P = 0.016]. Neither SNP was associated with mortality. This is the largest study to demonstrate a link between a genetic sRAGE determinant and CV risk. Only rs2070600, which enhances RAGE function by inducing a Gly82Ser polymorphism in the ligand-binding domain, was associated with MACE. The lack of associations with incident MACE for the other sRAGE-lowering SNPs suggests that this functional RAGE modification is central for the observed relationship.

Double-negative B cells and DNASE1L3 colocalise with microbiota in gut-associated lymphoid tissue

Intestinal homeostasis is maintained by the response of gut-associated lymphoid tissue to bacteria transported across the follicle associated epithelium into the subepithelial dome. The initial response to antigens and how bacteria are handled is incompletely understood. By iterative application of spatial transcriptomics and multiplexed single-cell technologies, we identify that the double negative 2 subset of B cells, previously associated with autoimmune diseases, is present in the subepithelial dome in health. We show that in this location double negative 2 B cells interact with dendritic cells co-expressing the lupus autoantigens DNASE1L3 and C1q and microbicides. We observe that in humans, but not in mice, dendritic cells expressing DNASE1L3 are associated with sampled bacteria but not DNA derived from apoptotic cells. We propose that fundamental features of autoimmune diseases are microbiota-associated, interacting components of normal intestinal immunity.

sRAGE levels are decreased in plasma and sputum of COPD secondary to biomass-burning smoke and tobacco smoking: Differences according to the rs3134940 AGER variant

The receptor for advanced glycation end products (RAGE) and its gene (AGER) have been related to lung injury and inflammatory diseases, including chronic obstructive pulmonary disease (COPD). We aimed to evaluate the association of rs2071288, rs3134940, rs184003, and rs2070600 AGER single-nucleotide variants and the soluble-RAGE plasma and sputum levels with COPD secondary to biomass-burning smoke (BBS) and tobacco smoking. Four groups, including 2189 subjects, were analyzed: COPD secondary to BBS exposure (COPD-BBS, n = 342), BBS-exposed subjects without COPD (BBES, n = 774), tobacco smoking-induced COPD (COPD-TS, n = 434), and smokers without COPD (SWOC, n = 639). Allelic discrimination assays determined the AGER variants. The sRAGE was quantified in plasma (n = 240) and induced-sputum (n = 72) samples from a subgroup of patients using the ELISA technique. In addition, a meta-analysis was performed for the association of rs2070600 with COPD susceptibility. None of the studied genetic variants were found to be associated with COPD-BBS or COPD-TS. A marginal association was observed for the rs3134940 with COPD-BBS (p = 0.066). The results from the meta-analysis, including six case-control studies (n = 4149 subjects), showed a lack of association of rs2070600 with COPD susceptibility (p = 0.681), probably due to interethnic differences. The sRAGE plasma levels were lower in COPD-BBS compared to BBS and in COPD-TS compared to SWOC. The sRAGE levels were also lower in sputum samples from COPD-BBS than BBES. Subjects with rs3134940-TC genotypes exhibit lower sRAGE plasma levels than TT subjects, mainly from the COPD-BBS and SWOC groups. The AGER variants were not associated with COPD-BBS nor COPD-TS, but the sRAGE plasma and sputum levels are related to both COPD-BBS and COPD-TS and are influenced by the rs3134940 variant.

Diabetic Pneumopathy- A Novel Diabetes-associated Complication: Pathophysiology, the Underlying Mechanism and Combination Medication

BACKGROUND

The "diabetic lung" has been identified as a possible target organ in diabetes, with abnormalities in ventilation control, bronchomotor tone, lung volume, pulmonary diffusing capacity, and neuroadrenergic bronchial innervation.

OBJECTIVE

This review summarizes studies related to diabetic pneumopathy, pathophysiology and a number of pulmonary disorders including type 1 and type 2 diabetes.

METHODS

Electronic searches were conducted on databases such as Pub Med, Wiley Online Library (WOL), Scopus, Elsevier, ScienceDirect, and Google Scholar using standard keywords "diabetes," "diabetes Pneumopathy," "Pathophysiology," "Lung diseases," "lung infection" for review articles published between 1978 to 2023 very few previous review articles based their focus on diabetic pneumopathy and its pathophysiology.

RESULTS

Globally, the incidence of diabetes mellitus has been rising. It is a chronic, progressive metabolic disease. The "diabetic lung" may serve as a model of accelerated ageing since diabetics' rate of respiratory function deterioration is two to three-times higher than that of normal, non-smoking people.

CONCLUSION

Diabetes-induced pulmonary dysfunction has not gained the attention it deserves due to a lack of proven causality and changes in cellular properties. The mechanism underlying a particular lung illness can still only be partially activated by diabetes but there is evidence that hyperglycemia is linked to pulmonary fibrosis in diabetic people.

Mechanistic insights into the alterations and regulation of the AKT signaling pathway in diabetic retinopathy

In the early stages of diabetic retinopathy (DR), diabetes-related hyperglycemia directly inhibits the AKT signaling pathway by increasing oxidative stress or inhibiting growth factor expression, which leads to retinal cell apoptosis, nerve proliferation and fundus microvascular disease. However, due to compensatory vascular hyperplasia in the late stage of DR, the vascular endothelial growth factor (VEGF)/phosphatidylinositol 3 kinase (PI3K)/AKT cascade is activated, resulting in opposite levels of AKT regulation compared with the early stage. Studies have shown that many factors, including insulin, insulin-like growth factor-1 (IGF-1), VEGF and others, can regulate the AKT pathway. Disruption of the insulin pathway decreases AKT activation. IGF-1 downregulation decreases the activation of AKT in DR, which abrogates the neuroprotective effect, upregulates VEGF expression and thus induces neovascularization. Although inhibiting VEGF is the main treatment for neovascularization in DR, excessive inhibition may lead to apoptosis in inner retinal neurons. AKT pathway substrates, including mammalian target of rapamycin (mTOR), forkhead box O (FOXO), glycogen synthase kinase-3 (GSK-3)/nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa-B (NF-κB), are a research focus. mTOR inhibitors can delay or prevent retinal microangiopathy, whereas low mTOR activity can decrease retinal protein synthesis. Inactivated AKT fails to inhibit FOXO and thus causes apoptosis. The GSK-3/Nrf2 cascade regulates oxidation and inflammation in DR. NF-κB is activated in diabetic retinas and is involved in inflammation and apoptosis. Many pathways or vital activities, such as the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and mitogen-activated protein kinase (MAPK) signaling pathways, interact with the AKT pathway to influence DR development. Numerous regulatory methods can simultaneously impact the AKT pathway and other pathways, and it is essential to consider both the connections and interactions between these pathways. In this review, we summarize changes in the AKT signaling pathway in DR and targeted drugs based on these potential sites.

Nanopore Sequencing of RAGE Gene Polymorphisms and Their Association with Type 2 Diabetes

The receptor for advanced glycation end products (RAGE) is a transmembrane protein that interacts with its ligands, advanced glycation end products (AGEs). AGEs are elevated in diabetes and diabetic complications, leading to increased oxidative stress and activation of pro-inflammatory pathways facilitated by AGE-RAGE signaling. Polymorphisms in the RAGE gene can potentially affect AGE-RAGE interaction and its downstream signaling, which plays a crucial role in the progression of diabetes and its complications. In this study, we used nanopore sequencing for genotyping of RAGE polymorphism and identified a maximum number of 33 polymorphisms, including two previously unreported novel mutations in a cohort of healthy, type 2 diabetics without nephropathy and type 2 diabetics with nephropathy in order to identify associations. Two novel RAGE polymorphisms in the intron 8 and 3'UTR region at genomic locations 32181834 and 32181132, respectively, were detected with a low frequency. For four previously reported polymorphisms, cross-validation by PCR-RFLP showed 99.75% concordance with nanopore sequencing. Analysis of genotype distribution and allele frequencies revealed that five single nucleotide polymorphisms, i.e., rs1800625, rs3131300, rs3134940, rs2070600, and rs9391855, were associated with an increased risk for type 2 diabetes.

Decoding the genetic relationship between Alzheimer's disease and type 2 diabetes: potential risk variants and future direction for North Africa

Introduction

Alzheimer's disease (AD) and Type 2 diabetes (T2D) are both age-associated diseases. Identification of shared genes could help develop early diagnosis and preventive strategies. Although genetic background plays a crucial role in these diseases, we noticed an underrepresentation tendency of North African populations in omics studies.

Materials and methods

First, we conducted a comprehensive review of genes and pathways shared between T2D and AD through PubMed. Then, the function of the identified genes and variants was investigated using annotation tools including PolyPhen2, RegulomeDB, and miRdSNP. Pathways enrichment analyses were performed with g:Profiler and EnrichmentMap. Next, we analyzed variant distributions in 16 worldwide populations using PLINK2, R, and STRUCTURE software. Finally, we performed an inter-ethnic comparison based on the minor allele frequency of T2D-AD common variants.

Results

A total of 59 eligible papers were included in our study. We found 231 variants and 363 genes shared between T2D and AD. Variant annotation revealed six single nucleotide polymorphisms (SNP) with a high pathogenic score, three SNPs with regulatory effects on the brain, and six SNPs with potential effects on miRNA-binding sites. The miRNAs affected were implicated in T2D, insulin signaling pathways, and AD. Moreover, replicated genes were significantly enriched in pathways related to plasma protein binding, positive regulation of amyloid fibril deposition, microglia activation, and cholesterol metabolism. Multidimensional screening performed based on the 363 shared genes showed that main North African populations are clustered together and are divergent from other worldwide populations. Interestingly, our results showed that 49 SNP associated with T2D and AD were present in North African populations. Among them, 11 variants located in DNM3, CFH, PPARG, ROHA, AGER, CLU, BDNF1, CST9, and PLCG1 genes display significant differences in risk allele frequencies between North African and other populations.

Conclusion

Our study highlighted the complexity and the unique molecular architecture of North African populations regarding T2D-AD shared genes. In conclusion, we emphasize the importance of T2D-AD shared genes and ethnicity-specific investigation studies for a better understanding of the link behind these diseases and to develop accurate diagnoses using personalized genetic biomarkers.

Integrative Mendelian randomization reveals the soluble receptor for advanced glycation end products as protective in relation to rheumatoid arthritis

Rheumatoid arthritis (RA) is a risk factor for atherosclerotic cardiovascular diseases (CVD). Given the critical roles of the immune system and inflammatory signals in the pathogenesis of CVD, we hypothesized that interrogation of CVD-related proteins using integrative genomics might provide new insights into the pathophysiology of RA. We utilized two-sample Mendelian randomization (MR) for causal inference between circulating protein levels and RA by incorporating genetic variants, followed by colocalization to characterize the causal associations. Genetic variants from three sources were obtained: those associated with 71 CVD-related proteins measured in nearly 7000 Framingham Heart Study participants, a published genome-wide association study (GWAS) of RA (19 234 cases, 61 565 controls), and GWAS of rheumatoid factor (RF) levels from the UK Biobank (n = 30 565). We identified the soluble receptor for advanced glycation end products (sRAGE), a critical inflammatory pathway protein, as putatively causal and protective for both RA (odds ratio per 1-standard deviation increment in inverse-rank normalized sRAGE level = 0.364; 95% confidence interval 0.342-0.385; P = 6.40 × 10-241) and RF levels (β [change in RF level per sRAGE increment] = - 1.318; SE = 0.434; P = 0.002). Using an integrative genomic approach, we highlight the AGER/RAGE axis as a putatively causal and promising therapeutic target for RA.

Contributions of the receptor for advanced glycation end products axis activation in gastric cancer

Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products (RAGE) axis activation in the development of neoplasms, including gastric cancer (GC). This new actor in tumor biology plays an important role in the onset of a crucial and long-lasting inflammatory milieu, not only by supporting phenotypic changes favoring growth and dissemination of tumor cells, but also by functioning as a pattern-recognition receptor in the inflammatory response to Helicobacter pylori infection. In the present review, we aim to highlight how the overexpression and activation of the RAGE axis contributes to the proliferation and survival of GC cells as and their acquisition of more invasive phenotypes that promote dissemination and metastasis. Finally, the contribution of some single nucleotide polymorphisms in the RAGE gene as susceptibility or poor prognosis factors is also discussed.

Identification of four metabolic subtypes and key prognostic markers in lung adenocarcinoma based on glycolytic and glutaminolytic pathways

BACKGROUND

Glucose and glutamine are the main energy sources for tumor cells. Whether glycolysis and glutaminolysis play a critical role in driving the molecular subtypes of lung adenocarcinoma (LUAD) is unknown. This study attempts to identify LUAD metabolic subtypes with different characteristics and key genes based on gene transcription profiling data related to glycolysis and glutaminolysis, and to construct prognostic models to facilitate patient outcome prediction.

METHODS

LUAD related data were obtained from the Cancer Genome Atlas and Gene Expression Omnibus, including TCGA-LUAD, GSE42127, GSE68465, GSE72094, GSE29013, GSE31210, GSE30219, GSE37745, GSE50081. Unsupervised consensus clustering was used for the identification of LUAD subtypes. Differential expression analysis, weighted gene co-expression network analysis (WGCNA) and CytoNCA App in Cytoscape 3.9.0 were used for the screening of key genes. The Cox proportional hazards model was used for the construction of the prognostic risk model. Finally, qPCR analysis, immunohistochemistry and immunofluorescence colocalization were used to validate the core genes of the model.

RESULT

This study identified four distinct characterized LUAD metabolic subtypes, glycolytic, glutaminolytic, mixed and quiescent types. The glycolytic type had a worse prognosis than the glutaminolytic type. Nine genes (CXCL8, CNR1, AGER, ALB, S100A7, SLC2A1, TH, SPP1, LEP) were identified as hub genes driving the glycolytic/glutaminolytic LUAD. In addition, the risk assessment model constructed based on three genes (SPP1, SLC2A1 and AGER) had good predictive performance and could be validated in multiple independent external LUAD cohorts. These three genes were differentially expressed in LUAD and lung normal tissues, and might be potential prognostic markers for LUAD.

CONCLUSION

LUAD can be classified into four different characteristic metabolic subtypes based on the glycolysis- and glutaminolysis-related genes. Nine genes (CXCL8, CNR1, AGER, ALB, S100A7, SLC2A1, TH, SPP1, LEP) may play an important role in the subtype-intrinsic drive. This metabolic subtype classification, provides new biological insights into the previously established LUAD subtypes.

HBD-2 variants and SARS-CoV-2: New insights into inter-individual susceptibility

Background

A deep understanding of the causes of liability to SARS-CoV-2 is essential to develop new diagnostic tests and therapeutics against this serious virus in order to overcome this pandemic completely. In the light of the discovered role of antimicrobial peptides [such as human b-defensin-2 (hBD-2) and cathelicidin LL-37] in the defense against SARS-CoV-2, it became important to identify the damaging missense mutations in the genes of these molecules and study their role in the pathogenesis of COVID-19.

Methods

We conducted a comprehensive analysis with multiple in silico approaches to identify the damaging missense SNPs for hBD-2 and LL-37; moreover, we applied docking methods and molecular dynamics analysis to study the impact of the filtered mutations.

Results

The comprehensive analysis reveals the presence of three damaging SNPs in hBD-2; these SNPs were predicted to decrease the stability of hBD-2 with a damaging impact on hBD-2 structure as well. G51D and C53G mutations were located in highly conserved positions and were associated with differences in the secondary structures of hBD-2. Docking-coupled molecular dynamics simulation analysis revealed compromised binding affinity for hBD-2 SNPs towards the SARS-CoV-2 spike domain. Different protein-protein binding profiles for hBD-2 SNPs, in relation to their native form, were guided through residue-wise levels and differential adopted conformation/orientation.

Conclusions

The presented model paves the way for identifying patients prone to COVID-19 in a way that would guide the personalization of both the diagnostic and management protocols for this serious disease.

Role of RAGE in the Pathogenesis of Neurological Disorders

This review reflects upon our own as well as other investigators' studies on the role of receptor for advanced glycation end-products (RAGE), bringing up the latest information on RAGE in physiology and pathology of the nervous system. Over the last ten years, major progress has been made in uncovering many of RAGE-ligand interactions and signaling pathways in nervous tissue; however, the translation of these discoveries into clinical practice has not come to fruition yet. This is likely, in part to be the result of our incomplete understanding of this crucial signaling pathway. Clinical trials examining the therapeutic efficacy of blocking RAGE-external ligand interactions by genetically engineered soluble RAGE or an endogenous RAGE antagonist, has not stood up to its promise; however, other trials with different blocking agents are being considered with hope for therapeutic success in diseases of the nervous system.

Role of RAGE and its ligand HMGB1 in the development of COPD

Smoking is a well-established risk factor for chronic obstructive pulmonary disease (COPD). Chronic lung inflammation continues even after smoking cessation and leads to COPD progression. To date, anti-inflammatory therapies are ineffective in improving pulmonary function and COPD symptoms, and new molecular targets are urgently needed to deal with this challenge. The receptor for advanced glycation end-products (RAGE) was shown to be relevant in COPD pathogenesis, since it is both a genetic determinant of low lung function and a determinant of COPD susceptibility. Moreover, RAGE is involved in the physiological response to cigarette smoke exposure. Since innate and acquired immunity plays an essential role in the development of chronic inflammation and emphysema in COPD, here we summarized the roles of RAGE and its ligand HMGB1 in COPD immunity.

Whole Exome Sequencing Revealed Variants That Predict Pulmonary Artery Involvement in Patients with Takayasu Arteritis

Purpose

To conduct the first whole exome sequencing (WES) on Takayasu arteritis (TAK) to identify common and rare variants responsible for disease susceptibility.

Patients and Methods

A total of 200 patients and 1675 healthy controls from China were recruited for this study. Site-based association analysis for common variants and gene-based burden analysis for rare variants were conducted. A weighted genetic risk score (wGRS) was calculated for each patient with TAK based on the independent risk alleles identified in the association analyses. The ability of the patient wGRS to discriminate between different phenotypes was evaluated.

Results

In the site-based analysis, the top association signal was CCHCR1 (rs1265067, p = 8.27 × 10^-12, OR = 2.41), a proxy for HLA-B*52:01. HLA-DQB1 (rs9273902), HLA-DQB2 (rs34109750), and a haplotype block in the human leukocyte antigen (HLA) class III region (represented by rs3130618) also exhibited significant associations independently. In addition, four novel non-HLA susceptibility loci were identified: PRRT4, TLL2, LRP1B, and DLGAP2. Twelve independently associated single nucleotide polymorphisms were used to calculate the wGRS. TAK patients with a higher wGRS were found to have an increased risk of pulmonary artery involvement compared with those with a lower wGRS (p = 5.76 × 10^-7, OR = 13.92). The wGRS algorithm showed good predictive capability for pulmonary artery involvement in TAK (sensitivity, 92.1%; specificity, 59.9%). In the gene-based analysis, risk genes that reached exome-wide significance were not identified.

Conclusion

This WES study on TAK supports a previously reported association within the HLA region. Moreover, novel susceptibility loci were identified outside the HLA region. These risk alleles showed potential associations with pulmonary artery involvement in TAK. However, additional studies are warranted to verify our findings.

RAGE against the Machine: Can Increasing Our Understanding of RAGE Help Us to Battle SARS-CoV-2 Infection in Pregnancy?

The receptor of advanced glycation end products (RAGE) is a receptor that is thought to be a key driver of inflammation in pregnancy, SARS-CoV-2, and also in the comorbidities that are known to aggravate these afflictions. In addition to this, vulnerable populations are particularly susceptible to the negative health outcomes when these afflictions are experienced in concert. RAGE binds a number of ligands produced by tissue damage and cellular stress, and its activation triggers the proinflammatory transcription factor Nuclear Factor Kappa B (NF-κB), with the subsequent generation of key proinflammatory cytokines. While this is important for fetal membrane weakening, RAGE is also activated at the end of pregnancy in the uterus, placenta, and cervix. The comorbidities of hypertension, cardiovascular disease, diabetes, and obesity are known to lead to poor pregnancy outcomes, and particularly in populations such as Native Hawaiians and Pacific Islanders. They have also been linked to RAGE activation when individuals are infected with SARS-CoV-2. Therefore, we propose that increasing our understanding of this receptor system will help us to understand how these various afflictions converge, how forms of RAGE could be used as a biomarker, and if its manipulation could be used to develop future therapeutic targets to help those at risk.

RAGE is a potential biomarker implicated in immune infiltrates and cellular senescence in lung adenocarcinoma

Background

Receptor for Advanced Glycation End‐products (RAGE) is an oncogene abnormally expressed in various cancers. However, the clinical value of RAGE and the biological role of RAGE in lung cancer have not been fully investigated.

Methods

We compared the RAGE expression using several public databases. The relationship between RAGE expression and clinicopathological variables was assessed. The R software package was used to carry out enrichment analyses of RAGE co‐expression and gene set enrichment analysis (GSEA). Additionally, we used the TIMER database to assess the association between immune infiltration and RAGE expression. The correlation between RAGE expression and senescence biomarkers in lung adenocarcinoma was analyzed using the TCGA database.

Results

Our findings indicated that the expression of RAGE was downregulated in lung adenocarcinoma, and down‐regulation of RAGE was related to poor overall survival and disease‐free survival. Functional enrichment analysis indicated that RAGE co‐expression genes were mainly associated with neutrophil activation involved in immune response, neutrophil degranulation, and regulation of leukocyte‐mediated immunity. Correlation analysis revealed that RAGE expression was closely related to the purity of the tumor and immune infiltration. GSEA indicated that the RAGE‐related differential genes were mainly enriched in senescence‐related pathways. Besides, the RAGE expression was significantly associated with senescence‐related genes.

Conclusion

Down‐regulation of RAGE expression was associated with poor prognosis, as well as defective immune infiltration and cellular senescence in lung adenocarcinoma.

Association of Polymorphisms in Inflammation Genes With the Prognosis of Advanced Non-Small Cell Lung Cancer Patients Receiving Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors

Background

Inflammation is not only involved in the development and progression of cancer but also affects the response to therapy. The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) in inflammation genes with the prognosis of advanced non-small cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).

Methods

Forty-seven SNPs were genotyped in 318 advanced NSCLC patients receiving EGFR-TKIs. Of 318 patients, 182 (57.2%) patients died during follow-up period. We assessed the association of SNPs with the progression-free survival (PFS) and overall survival (OS) as well as calculated the weighted genetic risk score (GRS). We also explored the expression levels and prognostic values of inflammation genes in lung adenocarcinoma (LUAD) in Gene Expression Profiling Interactive Analysis (GEPIA) and using UCSC Xena, respectively. The relationship between the expression levels of IL15, IL17RA, AGER, MIF, and TNFRSF1A and EGFR mutation status was analyzed using UCSC Xena.

Results

In single variant analyses, 3 SNPs (rs10519613, rs4819554, and rs4149570) were significantly associated with worse PFS. Five SNPs (rs10519613, rs4819554, rs2070600, rs755622, and rs4149570) were significantly with worse OS. In addition, high and intermediate GRSs (based on rs10519613, rs4819554, and rs4149570) were associated with worse PFS than those with low GRS. For OS, patients with high GRSs (based on rs10519613, rs4819554, rs2070600, rs755622, and rs4149570) had shorter survival time than those with low GRS. Furthermore, IL15, IL17RA, AGER, MIF, and TNFRSF1A were dysregulated in LUAD. There was difference in the expression level of TNFRSF1A between EGFR wildtype and EGFR-mutant LUAD. Both low AGER expression and high TNFRSF1A expression were significantly associated with worse PFS in LUAD. In addition, low IL17RA and AGER expression, high MIF and TNFRSF1A expression were significantly associated with worse OS in LUAD.

Conclusion

SNPs in inflammation genes could serve as prognostic biomarkers for NSCLC patients treated with EGFR-TKIs.

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.

Single nucleotide variants of receptor for advanced glycation end-products (AGER) gene: is it a new opening in the risk assessment of diabetic retinopathy?-a review

Background

Diabetic retinopathy (DR) is a common microvascular complication of diabetes. There is strong evidence suggesting that DR has an inheritable component. The interaction between advanced glycation end products (AGEs) and their receptor is integral in the pathogenesis of diabetic retinopathy and its various complications, retinopathy being one of them.

Overview and methodology

This review discusses the existing literature on the association between single nucleotide variants (SNV) of AGER gene and the risk of DR. It also discusses the current understanding of the AGE-AGER pathway in diabetic retinopathy. Through our article we have tried to consolidate all the available information about these SNVs associated with diabetic retinopathy in a succinct tabular form. Additionally, a current understanding of the AGE-AGER interaction and its deleterious effects on the cells of the retina has been discussed in detail to provide comprehensive information about the topic to the reader. A literature review was performed on PubMed, Cochrane Library, and Google Scholar for studies to find existing literature on the association between AGER gene SNVs and the risk, progression and severity of developing DR. This article will encourage scientific communication and discussion about possibly devising genetic markers for an important cause of blindness both in developed and developing countries, i.e., diabetic retinopathy.

Result

Based on genetic studies done in Indian and Chinese population G82S(rs2070600) was positively associated with Diabetic Retinopathy. Patients of diabetic retinopathy in Caucasian population had −T374A(rs1800624) polymorphism. + 20T/A was found to be associated with the disease in a study done in UK. Association with G1704T(rs184003) was seen in Chinese and Malaysian population. A Chinese study found its association with CYB242T. -T429C(rs1800625) SNV was not associated with DR in any of the studies. G2245A(rs55640627) was positively associated with the disease process in Malaysian population. It was not associated in Malaysian and Chinese population. Promoter variant rs1051993 has also been found to a susceptible SNV in the Chinese population.

Conclusion

While providing a comprehensive review of the existing information, we would like to emphasize on a large, multi-centric, trial with a much larger and varied population base to definitely determine these single nucleotide variants predisposing diabetic individuals.

Blood protein profiles related to preterm birth and retinopathy of prematurity

BACKGROUND

Nearly one in ten children is born preterm. The degree of immaturity is a determinant of the infant's health. Extremely preterm infants have higher morbidity and mortality than term infants. One disease affecting extremely preterm infants is retinopathy of prematurity (ROP), a multifactorial neurovascular disease that can lead to retinal detachment and blindness. The advances in omics technology have opened up possibilities to study protein expressions thoroughly with clinical accuracy, here used to increase the understanding of protein expression in relation to immaturity and ROP.

METHODS

Longitudinal serum protein profiles the first months after birth in 14 extremely preterm infants were integrated with perinatal and ROP data. In total, 448 unique protein targets were analyzed using Proximity Extension Assays.

RESULTS

We found 20 serum proteins associated with gestational age and/or ROP functioning within mainly angiogenesis, hematopoiesis, bone regulation, immune function, and lipid metabolism. Infants with severe ROP had persistent lower levels of several identified proteins during the first postnatal months.

CONCLUSIONS

The study contributes to the understanding of the relationship between longitudinal serum protein levels and immaturity and abnormal retinal neurovascular development. This is essential for understanding pathophysiological mechanisms and to optimize diagnosis, treatment and prevention for ROP.

IMPACT

Longitudinal protein profiles of 14 extremely preterm infants were analyzed using a novel multiplex protein analysis platform combined with perinatal data. Proteins associated with gestational age at birth and the neurovascular disease ROP were identified. Among infants with ROP, longitudinal levels of the identified proteins remained largely unchanged during the first postnatal months. The main functions of the proteins identified were angiogenesis, hematopoiesis, immune function, bone regulation, lipid metabolism, and central nervous system development. The study contributes to the understanding of longitudinal serum protein patterns related to gestational age and their association with abnormal retinal neuro-vascular development.

A genomic approach identifies sRAGE as a putatively causal protein for asthma

BACKGROUND

Asthma is a complex respiratory condition caused by environmental and genetic factors. Although lower concentrations of the anti-inflammatory protein sRAGE have been associated with asthma in humans and mouse models, it is uncertain whether sRAGE plays a causal role in asthma.

OBJECTIVE

We designed a two-stage study of sRAGE in relation to asthma with i) association analysis in FHS participants and ii) causal inference testing using MR.

METHODS

We measured plasma levels of sRAGE and performed cross-sectional analysis to examine the association between plasma sRAGE concentration and asthma status in 6,546 FHS participants. We then used sRAGE pQTLs derived from a GWAS of plasma sRAGE levels in ∼7,000 FHS participants with UK Biobank asthma GWAS in MR to consider sRAGE as a putatively causal protein for asthma. We also performed replication MR using an externally-derived sRAGE pQTL from the INTERVAL study. Last, we conducted colocalization using cis-pQTL variants at the AGER locus with variants from the UK Biobank asthma GWAS.

RESULTS

Association analysis revealed that each 1 SD increment in sRAGE concentration was associated with a 14% lower odds of asthma in FHS participants (95% CI 0.76-0.96). MR identified sRAGE as putatively causal for and protective against asthma based on self-reported (OR [per 1 SE increment in inverse rank-normalized sRAGE]=0.97, 95% CI 0.95-0.99; p=0.005) and doctor-diagnosed asthma (OR=0.97, 95% CI 0.95-0.99; p=0.011).

CONCLUSION

Through this genomic approach, we identified sRAGE as a putatively causal, biologically important, and protective protein in relation to asthma. Functional studies in cell/animal models are needed to confirm our findings.

AGER gene variant as a risk factor for juvenile idiopathic arthritis

BACKGROUND

The AGER gene encodes a cell surface multiligand receptor of advanced glycation end-products that is also capable of binding other molecules and is involved in numerous pathways related to inflammation, apoptosis, immunity and so on. In the present study, we aimed to investigate whether the AGER rs1035798 (G>A) intronic polymorphism, showing an association with multiple sclerosis and rheumatoid arthritis in adults, is related to juvenile idiopathic arthritis (JIA).

METHODS

Caucasian children from the Belarusian population were enrolled in the study. In total, there were 201 cases with JIA, 37 with juvenile systemic lupus erythematosus, 222 children with the articular syndrome of non-autoimmune etiology (positive control for JIA) and 365 negative controls (children without any autoimmune or inflammatory diseases). Genomic DNA samples from the patients and controls were genotyped by a real-time polymerase chain reaction.

RESULTS

A marked association of the homozygous AA rs1035798 genotype with JIA (p = 5 × 10^-4 ) was found. Allele A was also associated with JIA (p = 0.0058), as well as with the articular syndrome of non-autoimmune etiology (p = 0.0264). The highest frequencies of the AA genotype were found in the subgroups of JIA patients with polyarthritis or severe oligoarthritis. The AA genotype patients also had the smallest mean age of the JIA onset.

CONCLUSIONS

Our results demonstrate that the AGER rs1035798 AA genotype is a risk factor for JIA in Belarusian children. They also suggest a link between the AGER AA genotype and the risk of JIA early onset and severity. However, the functional relevance of the rs1035798 polymorphism is still unclear.

Association of four gene polymorphisms in Chinese Guangxi population with diabetic retinopathy in type 2 diabetic patients

Background

Diabetic retinopathy (DR) is one of the most common chronic microvascular complications of diabetes. Many studies have suggested that genetic factors are important in the context of DR. This study evaluated the associations of GWAS (Genome-wide association study) -identified DR-associated SNPs in a Chinese population in Guangxi Province with type 2 diabetes mellitus (T2DM).

Methods

A total of 386 hospitalized T2DM patients without proliferative diabetic retinopathy (PDR) and 316 hospitalized T2DM patients with PDR were included in this case–control study. Four tag SNPs, including rs1800896 in the IL-10 gene, rs2010963 in the VEGFA gene, rs2070600 in the RAGE gene and rs2910164 in the miR-146a gene, were examined using KASP (kompetitive allele specific PCR) genotyping assays.

Results

There were no significant differences in the genotype or allele frequencies of the miR-146a polymorphism (rs2910164) between subjects with PDR and those without DR. The TC genotype of rs1800896 was determined to be associated with an increased risk of PDR (the odds ratio (OR) was 2.366, with a 95% confidence interval (CI) ranging from 1.144 to 4.894). The CG genotypes of rs2010963 was associated with an decreased risk of PDR (the OR was 0.588, with a 95% CI ranging from 0.366 to 0.946). Regarding rs2070600, 2 genotypes (TT and CT) were associated with a decreased risk of PDR (the OR of the TT genotype was 0.180, with a 95% CI ranging from 0.037 to 0.872, and the OR of the CT genotype was 0.448, with a 95% CI ranging from 0.266 to 0.753).

Conclusions

The rs1800896 polymorphisms in the IL-10 gene, rs2010963 in the VEGFA gene and rs2070600 in the RAGE gene are associated with the risk of PDR in the Han Chinese population of Guangxi Province. Our findings provide suggestive evidence that these polymorphisms may be involved in the pathogenesis of PDR and should be investigated further.

Implication of RAGE Polymorphic Variants in COPD Complication and Anti-COPD Therapeutic Potential of sRAGE

Chronic obstructive pulmonary disease (COPD) is a slowly progressive and poorly reversible airway obstruction disease. It is caused either alone or in combination of emphysema, chronic bronchitis (CB), and small airways disease. COPD is thought to be a multi-factorial disorder in which genetic susceptibility, environmental factors and tobacco exposure could be doubly or simultaneously implicated. Available medicines against COPD include anti-inflammatory drugs, such as β2-agonists and anticholinergics, which efficiently reduce airflow limitation but are unable to avert disease progression and mortality. Advanced glycation end products (AGE) and their receptors i.e. receptor for advanced glycation end products (RAGE) are some molecules that have been implicated in the complication of COPD. Several RAGE single nucleotide polymorphic (SNP) variants are produced by the mammalian cells. Based on the ethnicity some SNPs aggravate the COPD severity. Mammalian cells produce several alternative RAGE splice variants including a soluble RAGE (sRAGE) and an endogenous soluble RAGE (esRAGE). Both of these act as decoy receptor and thus may help to arrest the COPD complications. Several lines of evidences indicate a decreased level of sRAGE in the COPD subjects. One of the new strategies to reduce COPD complication may be sRAGE therapeutic administration to the COPD subjects. This comprehensive discussion sheds light on the role of RAGE and its polymorphic variants in the COPD complication along with sRAGE therapeutic significance in the COPD prevention.

Testosterone in COVID-19: An Adversary Bane or Comrade Boon

COVID-19 is a pandemic disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2), which leads to pulmonary manifestations like acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition, COVID-19 may cause extra-pulmonary manifestation such as testicular injury. Both high and low levels of testosterone could affect the severity of COVID-19. Herein, there is substantial controversy regarding the potential role of testosterone in SARS-CoV-2 infection and COVID-19 severity. Therefore, the present study aimed to review and elucidate the assorted view of preponderance regarding the beneficial and harmful effects of testosterone in COVID-19. A related literature search in PubMed, Scopus, Web of Science, Google Scholar, and Science Direct was done. All published articles related to the role of testosterone and COVID-19 were included in this mini-review. The beneficial effects of testosterone in COVID-19 are through inhibition of pro-inflammatory cytokines, augmentation of anti-inflammatory cytokines, modulation of the immune response, attenuation of oxidative stress, and endothelial dysfunction. However, its harmful effects in COVID-19 are due to augmentation of transmembrane protease serine 2 (TMPRSS2), which is essential for cleaving and activating SARS-CoV-2 spike protein during acute SARS-CoV-2 infection. Most published studies illustrated that low testosterone levels are linked to COVID-19 severity. A low testosterone level in COVID-19 is mainly due to testicular injury, the primary source of testosterone.

The cross-talk between RAGE and DIAPH1 in neurological complications of diabetes: A review

Neuropathy, or dysfunction of peripheral nerve, is one of the most common neurological manifestation in patients with diabetes mellitus (DM). DM is typically associated with a hyperglycaemic milieu, which promotes non-enzymatic glycation of proteins. Proteins with advanced glycation are known to engage a cell-surface receptor called the receptor for advanced glycation end products (RAGE). Thus, it is reasonable to assume that RAGE and its associated molecule-mediated cellular signalling may contribute to DM-induced symmetrical axonal (length-dependent) neuropathy. Of particular interest is diaphanous related formin 1 (DIAPH1), a cytoskeletal organizing molecule, which interacts with the cytosolic domain of RAGE and whose dysfunction may precipitate axonopathy/neuropathy. Indeed, it has been demonstrated that both RAGE and DIAPH1 are expressed in the motor and sensory fibres of nerve harvested from DM animal models. Although the detailed molecular role of RAGE and DIAPH1 in diabetic neurological complications remains unclear, here we will discuss available evidence of their involvement in peripheral diabetic neuropathy. Specifically, we will discuss how a hyperglycaemic environment is not only likely to elevate advanced glycation end products (ligands of RAGE) and induce a pro-inflammatory environment but also alter signalling via RAGE and DIAPH1. Further, hyperglycaemia may regulate epigenetic mechanisms that interacts with RAGE signalling. We suggest the cumulative effect of hyperglycaemia on RAGE-DIAPH1-mediated signalling may be disruptive to axonal cytoskeletal organization and transport and is therefore likely to play a key role in pathogenesis of diabetic symmetrical axonal neuropathy.

Hyperactivated RAGE in Comorbidities as a Risk Factor for Severe COVID-19-The Role of RAGE-RAS Crosstalk

The receptor for advanced glycation-end products (RAGE) is a multiligand receptor with a role in inflammatory and pulmonary pathologies. Hyperactivation of RAGE by its ligands has been reported to sustain inflammation and oxidative stress in common comorbidities of severe COVID-19. RAGE is essential to the deleterious effects of the renin-angiotensin system (RAS), which participates in infection and multiorgan injury in COVID-19 patients. Thus, RAGE might be a major player in severe COVID-19, and appears to be a useful therapeutic molecular target in infections by SARS-CoV-2. The role of RAGE gene polymorphisms in predisposing patients to severe COVID-19 is discussed.&nbsp.

DNA Methylation in Babies Born to Nonsmoking Mothers Exposed to Secondhand Smoke during Pregnancy: An Epigenome-Wide Association Study

BACKGROUND

Maternal smoking during pregnancy is related to altered DNA methylation in infant umbilical cord blood. The extent to which low levels of smoke exposure among nonsmoking pregnant women relates to offspring DNA methylation is unknown.

OBJECTIVE

This study sought to evaluate relationships between maternal prenatal plasma cotinine levels and DNA methylation in umbilical cord blood in newborns using the Infinium HumanMethylation 450K BeadChip.

METHODS

Participants from the Newborn Epigenetics Study cohort who reported not smoking during pregnancy had verified low levels of cotinine from maternal prenatal plasma (0 ng / mL to < 4  ng / mL ), and offspring epigenetic data from umbilical cord blood were included in this study (n = 79 ). Multivariable linear regression models were fit to the data, controlling for cell proportions, age, race, education, and parity. Estimates represent changes in response to any 1 -ng / mL unit increase in exposure.

RESULTS

Multivariable linear regression models yielded 29,049 CpGs that were differentially methylated in relation to increases in cotinine at a 5% false discovery rate. Top CpGs were within or near genes involved in neuronal functioning (PRKG1, DLGAP2, BSG), carcinogenesis (FHIT, HSPC157) and inflammation (AGER). Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest cotinine was related to methylation of gene pathways controlling neuronal signaling, metabolic regulation, cell signaling and regulation, and cancer. Further, enhancers associated with transcription start sites were enriched in altered CpGs. Using an independent sample from the same study population (n = 115 ), bisulfite pyrosequencing was performed with infant cord blood DNA for two genes within our top 20 hits (AGER and PRKG1). Results from pyrosequencing replicated epigenome results for PRKG1 (cg17079497, estimate = - 1.09 , standard error  ( SE ) = 0.45 , p = 0.018 ) but not for AGER (cg09199225; estimate = - 0.16 , SE = 0.21 , p = 0.44 ).

DISCUSSION

Secondhand smoke exposure among nonsmoking women may alter DNA methylation in regions involved in development, carcinogenesis, and neuronal functioning. These novel findings suggest that even low levels of smoke exposure during pregnancy may be sufficient to alter DNA methylation in distinct sites of mixed umbilical cord blood leukocytes in pathways that are known to be altered in cord blood from pregnant active smokers. https://doi.org/10.1289/EHP8099.

The axis of the receptor for advanced glycation endproducts in asthma and allergic airway disease

Asthma is a generalized term that describes a scope of distinct pathologic phenotypes of variable severity, which share a common complication of reversible airflow obstruction. Asthma is estimated to affect almost 400 million people worldwide, and nearly ten percent of asthmatics have what is considered "severe" disease. The majority of moderate to severe asthmatics present with a "type 2-high" (T2-hi) phenotypic signature, which pathologically is driven by the type 2 cytokines Interleukin-(IL)-4, IL-5, and IL-13. However, "type 2-low" (T2-lo) phenotypic signatures are often associated with more severe, steroid-refractory neutrophilic asthma. A wide range of clinical and experimental studies have found that the receptor for advanced glycation endproducts (RAGE) plays a significant role in the pathogenesis of asthma and allergic airway disease (AAD). Current experimental data indicates that RAGE is a critical mediator of the type 2 inflammatory reactions which drive the development of T2-hi AAD. However, clinical studies demonstrate that increased RAGE ligands and signaling strongly correlate with asthma severity, especially in severe neutrophilic asthma. This review presents an overview of the current understandings of RAGE in asthma pathogenesis, its role as a biomarker of disease, and future implications for mechanistic studies, and potential therapeutic intervention strategies.

Soluble receptor for advanced glycation end products (sRAGE) as a biomarker of COPD

BACKGROUND

Soluble receptor for advanced glycation end products (sRAGE) is a proposed emphysema and airflow obstruction biomarker; however, previous publications have shown inconsistent associations and only one study has investigate the association between sRAGE and emphysema. No cohorts have examined the association between sRAGE and progressive decline of lung function. There have also been no evaluation of assay compatibility, receiver operating characteristics, and little examination of the effect of genetic variability in non-white population. This manuscript addresses these deficiencies and introduces novel data from Pittsburgh COPD SCCOR and as well as novel work on airflow obstruction. A meta-analysis is used to quantify sRAGE associations with clinical phenotypes.

METHODS

sRAGE was measured in four independent longitudinal cohorts on different analytic assays: COPDGene (n = 1443); SPIROMICS (n = 1623); ECLIPSE (n = 2349); Pittsburgh COPD SCCOR (n = 399). We constructed adjusted linear mixed models to determine associations of sRAGE with baseline and follow up forced expiratory volume at one second (FEV₁) and emphysema by quantitative high-resolution CT lung density at the 15th percentile (adjusted for total lung capacity).

RESULTS

Lower plasma or serum sRAGE values were associated with a COPD diagnosis (P < 0.001), reduced FEV₁ (P < 0.001), and emphysema severity (P < 0.001). In an inverse-variance weighted meta-analysis, one SD lower log₁₀-transformed sRAGE was associated with 105 ± 22 mL lower FEV₁ and 4.14 ± 0.55 g/L lower adjusted lung density. After adjusting for covariates, lower sRAGE at baseline was associated with greater FEV₁ decline and emphysema progression only in the ECLIPSE cohort. Non-Hispanic white subjects carrying the rs2070600 minor allele (A) and non-Hispanic African Americans carrying the rs2071288 minor allele (A) had lower sRAGE measurements compare to those with the major allele, but their emphysema-sRAGE regression slopes were similar.

CONCLUSIONS

Lower blood sRAGE is associated with more severe airflow obstruction and emphysema, but associations with progression are inconsistent in the cohorts analyzed. In these cohorts, genotype influenced sRAGE measurements and strengthened variance modelling. Thus, genotype should be included in sRAGE evaluations.

The use of the soluble receptor for advanced glycation-end products (sRAGE) as a potential biomarker of disease risk and adverse outcomes

The soluble receptor for advanced glycation end-products (sRAGE) has been classically considered a sink for pro-inflammatory RAGE ligands and as such has been associated with protection from inflammatory stress and disease. An alternative, though not mutually exclusive view is that high levels of sRAGE in circulation reflect the overstimulation of cell surface RAGE which if persistent, lead to the amplification of pro-inflammatory processes and the exacerbation of pathological states. With these two scenarios in mind this review focuses on the potential role of sRAGE as a prospective biomarker of disease risk and adverse outcomes.

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The prognostic value of measuring sRAGE levels in blood is subjected to debate.

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Raised sRAGE levels may result from the overstimulation of cell surface RAGE.

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Raised sRAGE may reflect chronic inflammation and multimorbidity rather than a healthy state.

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sRAGE is a promising biomarker of disease risk and adverse outcomes.

Age-Influenced Receptors of Advanced Glycation End Product Overexpression Associated With Osteogenic Differentiation Impairment in Patients With Type 2 Diabetes

Preclinical studies have found impaired osteogenic differentiation to be associated with type 2 diabetes (T2DM), which is related to skeletal accumulation of advanced glycation end products (AGEs). Our previous study also showed impaired osteogenic differentiation in peripheral blood-derived mononuclear cells (PBMC) isolated from patients with long-standing T2DM, which is conceivably due to the overexpression of receptor of advance glycation end products (RAGE) and the enhancement of cellular apoptosis. However, the existence of RAGE overexpression in earlier stages of diabetes remains unclear, as do the factors influencing that RAGE overexpression. This cross-sectional study enrolled 40 patients with T2DM treated with metformin monotherapy and 30 age-matched non-diabetic controls (NDM) to investigate the overexpression of RAGE in PBMC derived from patients with earlier stage diabetes, as well as to explore its determining factors. Almost all (90%) PBMC-isolated from NDM (NDM-pD) expressed osteoblast-specific genes including ALPL, BGLAP, COL1A1, and RUNX2/PPAR while only 40% of PBMC-derived from diabetic patients (DM-pD) expressed those genes. By using age- and pentosidine-matched NDM-pD as a reference, AGER and BAX/BCL2 expression in PBMC isolated from diabetic patients showing impaired osteoblast-specific gene expression (DM-iD) were 6.6 and 5 folds higher than the reference while AGER and BAX/BCL2 expression in DM-pD were comparable to the reference. AGER expression showed a significant positive correlation with age (r=0.470, p=0.003). The multivariate analysis demonstrated that both age and AGER expression correlated with the potential for osteogenic differentiation in the PBMC isolated from patients with diabetes. In conclusion, this study showed osteogenic differentiation impairment in approximately half of PBMC derived from type 2 diabetic patients receiving metformin monotherapy. Both AGER and BAX/BCL2 overexpression were demonstrated only in PBMC-isolated from diabetic patients with poor osteogenic differentiation. Therefore, this study not only illustrated the existence of RAGE overexpression in PBMC derived from patients with early stages of T2DM but also strengthened the linkage between that RAGE overexpression and the retardation of osteogenic differentiation. Age was also shown to be a positive influencing factor for RAGE overexpression. Furthermore, both age and RAGE overexpression were demonstrated as independent risk factors for determining osteogenic differentiation potential of the PBMC-isolated from T2DM.

Soluble Receptor for Advanced Glycation End-products (sRAGE) and Colorectal Cancer Risk: A Case-Control Study Nested within a European Prospective Cohort

BACKGROUND

Overexpression of the receptor for advanced glycation end-product (RAGE) has been associated with chronic inflammation, which in turn has been associated with increased colorectal cancer risk. Soluble RAGE (sRAGE) competes with RAGE to bind its ligands, thus potentially preventing RAGE-induced inflammation.

METHODS

To investigate whether sRAGE and related genetic variants are associated with colorectal cancer risk, we conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC). Plasma sRAGE concentrations were measured by ELISA in 1,361 colorectal cancer matched case-control sets. Twenty-four SNPs encoded in the genes associated with sRAGE concentrations were available for 1,985 colorectal cancer cases and 2,220 controls. Multivariable adjusted ORs and 95% confidence intervals (CIs) were computed using conditional and unconditional logistic regression for colorectal cancer risk and circulating sRAGE and SNPs, respectively.

RESULTS

Higher sRAGE concentrations were inversely associated with colorectal cancer (ORQ5vs.Q1, 0.77; 95% CI, 0.59-1.00). Sex-specific analyses revealed that the observed inverse risk association was restricted to men (ORQ5vs.Q1, 0.63; 95% CI, 0.42-0.94), whereas no association was observed in women (ORQ5vs.Q1, 1.00; 95% CI, 0.68-1.48; P heterogeneity for sex = 0.006). Participants carrying minor allele of rs653765 (promoter region of ADAM10) had lower colorectal cancer risk (C vs. T, OR, 0.90; 95% CI, 0.82-0.99).

CONCLUSIONS

Prediagnostic sRAGE concentrations were inversely associated with colorectal cancer risk in men, but not in women. An SNP located within ADAM10 gene, pertaining to RAGE shedding, was associated with colorectal cancer risk.

IMPACT

Further studies are needed to confirm our observed sex difference in the association and better explore the potential involvement of genetic variants of sRAGE in colorectal cancer development.

sRAGE as severe acute bronchiolitis biomarker, prospective observational study

INTRODUCTION AND OBJECTIVES

Acute bronchiolitis (AB) is the leading cause of hospitalization in infants and around 5% require intensive care treatment. Early identification of children diagnosed with AB at a high risk of severe progression is of great interest. The receptor for advanced glycation end products (RAGE), highly expressed in lung tissue, regulates immune responses and inflammation, and its soluble form, sRAGE, is believed to have an anti-inflammatory role. We hypothesized serum sRAGE might be a major determinant of AB severity and prognosis. This study was conducted to measure serum sRAGE in infants with severe AB and to assess its correlation with clinical severity, immediate complications, and outcome.

METHODS

Single-center, prospective, observational study of hospitalized children with severe bronchiolitis admitted to the Pediatric Intensive Care Unit (PICU), from September 2015 to September 2016.

RESULTS

A total of 52 children and 27 controls were included. The cases age ranged from 11 days to 21 months, resulting in a significant age difference with controls (11.85 vs 4.84 months, P < .01). Serum levels of sRAGE were lower but not significant in severe AB patients than in controls (1350.93 vs 1450.42 pg/mL; P = .399). No correlation was found between serum sRAGE and causative viruses, clinical symptoms, Wood-Downes score (a clinical severity score) on admission, respiratory support, or length of hospital stay. Serum sRAGE was also lower in the cases having had a previous respiratory disease (1463.84 vs 1072.43 pg/mL; P = .049). However, it was higher in patients with any lung consolidation on the chest X-ray (1584.79 vs 1131.62 pg/mL; P = .044) and weakly positively correlated with classical biomarkers (maximum C-reactive protein, +0.295, P = .034; maximum procalcitonin, +0.309; P = .029).

CONCLUSION

This single-center study reveals that sRAGE couldn't predict AB severity or outcome in children hospitalized at PICU. Nevertheless, it significantly increased in the presence of any lung consolidation and had a positive correlation with classical biomarkers. The utility of sRAGE in this population could be probably elucidated with a better understanding of AGE-RAGE axis.

The AGE-RAGE Axis and RAGE Genetics in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous group of lung diseases limiting the airflow due to narrowing of airways, chronic bronchitis and emphysema that leads to difficulties in breathing. Chronic inflammation is another important characteristic of COPD which leads to immune cell infiltration and helps in the alveolar destruction. Pathology of COPD is driven by various environmental and genetic factors. COPD is mainly associated with the inhalation of toxic agents mainly the cigarette smoke. Receptor for advanced glycation end products (RAGE) has emerged as a pattern recognition receptor and is a multiligand receptor expressed moderately in various cells, tissues and highly in the lungs throughout life. RAGE recognizes various ligands produced by cigarette smoke and its role has been implicated in the pathogenesis of COPD. RAGE ligands have been reported to accumulate in the lungs of patients with COPD. RAGE is a membrane receptor but its truncated form i.e. soluble RAGE (sRAGE) mainly functions as a contender of RAGE and inhibits various RAGE dependent cell signalling. Among the various ligands of RAGE, advanced glycation end products (AGEs) are majorly linked with COPD. Accumulated AGE triggers downstream RAGE-AGE axis in COPD. Moreover, RAGE genetics has long been known to play a vital role in the pathology of various airway diseases including COPD and this gene contains an associated locus. A reliable biomarker is needed for the management of this disease. sRAGE has an inverse correlation with the RAGE showed its importance as a valuable marker in COPD. This review is focused on the role of RAGE, sRAGE, RAGE axis and RAGE genetics in COPD.

Receptor for advanced glycation end-product rs1800624 polymorphism contributes to increase breast cancer risk: Evidence from a meta-analysis

BACKGROUND

Although several studies have identified an association between the receptor for advanced glycation end-product (RAGE) rs1800624 polymorphism and breast cancer, the results have been conflicting. Therefore, we conducted a meta-analysis to assess the relationship between the RAGE rs1800624 polymorphism and breast cancer risk.

METHODS

Studies were searched in the PubMed, Web of Science, Embase, Wanfang Med Online, and China National Knowledge Infrastructure databases until September 20, 2019 to identify all potential literature on this association. Fixed-effect or random-effect models were used to calculate odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs). Subgroup and sensitivity analyses and tests for publication bias were also performed.

RESULTS

Five eligible studies involving 2823 subjects (1410 patients and 1413 healthy controls) were included in the current meta-analysis. The pooled analysis indicated a positive correlation between the RAGE rs1800624 polymorphism and the risk of breast cancer in a homozygous genetic model (OR = 1.423, 95% CI = 1.043-1.941, P = .026). Ethnicity-based subgroup analysis demonstrated that RAGE rs1800624 polymorphism may increase the risk of breast cancer in the Asian population in homozygous model (OR = 1.661, 95% CI = 1.178-2.342, P = .004).

CONCLUSION

The RAGE rs1800624 polymorphism may increase the risk of breast cancer in the homozygous genetic model, especially in Asian populations. Large-scale and well-designed studies are needed in different populations to further evaluate the role of the RAGE polymorphism in breast cancer.

Association of rs2070600 in advanced glycosylation end-product specific receptor with prognosis of heart failure

Aims

Our objective was to investigate the association of common variants in the coding region of advanced glycosylation end‐product specific receptor (RAGE) and the prognosis of heart failure (HF).

Methods and results

A total of 3394 HF patients were continuously enrolled from January 2009 to August 2018 with a median follow‐up of 20.4 months. Additionally, 2861 healthy subjects also participated in the study. By sequencing these two groups, we identified a common functional missense variant rs2070600 in the coding region of RAGE, which showed a significant association with the prognosis of HF [hazard ratio = 0.53, 95%, confidence interval (CI) = 0.30–0.94, P = 0.03], but no association with the risk of HF (odds ratio = 0.52, 95%, CI = 0.66–1.04, P = 0.106). A series of functional assays revealed that rs2070600‐A, but not ‐G allele, suppressed the expression of RAGE protein by facilitating the binding of miR‐125a‐3p. Furthermore, the RAGE messenger RNA levels of human peripheral blood lymphocytes were reduced in subjects with the rs2070600‐AA genotype compared with subjects with the rs2070600‐GG or ‐AG genotypes. Additionally, our Western blot results from human heart tissue showed increased RAGE expression in HF samples compared with that in healthy donors.

Conclusions

Our results demonstrate that the common missense variant rs2070600‐A allele is associated with a reduced risk of cardiovascular death and cardiac transplantation by facilitating the binding of miR‐125a‐3p.

Therapy-Induced Evolution of Human Lung Cancer Revealed by Single-Cell RNA Sequencing

Lung cancer, the leading cause of cancer mortality, exhibits heterogeneity that enables adaptability, limits therapeutic success, and remains incompletely understood. Single-cell RNA sequencing (scRNA-seq) of metastatic lung cancer was performed using 49 clinical biopsies obtained from 30 patients before and during targeted therapy. Over 20,000 cancer and tumor microenvironment (TME) single-cell profiles exposed a rich and dynamic tumor ecosystem. scRNA-seq of cancer cells illuminated targetable oncogenes beyond those detected clinically. Cancer cells surviving therapy as residual disease (RD) expressed an alveolar-regenerative cell signature suggesting a therapy-induced primitive cell-state transition, whereas those present at on-therapy progressive disease (PD) upregulated kynurenine, plasminogen, and gap-junction pathways. Active T-lymphocytes and decreased macrophages were present at RD and immunosuppressive cell states characterized PD. Biological features revealed by scRNA-seq were biomarkers of clinical outcomes in independent cohorts. This study highlights how therapy-induced adaptation of the multi-cellular ecosystem of metastatic cancer shapes clinical outcomes.

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scRNA-seq is feasible in metastatic human NSCLCs and reveals a rich tumor ecosystem

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Individual tumors and cancer cells exhibit substantial molecular diversity

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Cancer and tumor microenvironment cells exhibit marked therapy-induced plasticity

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scRNA-seq of metastatic NSCLCs unveils new opportunities to improve clinical outcomes

The Gly82Ser mutation in AGER contributes to pathogenesis of pulmonary fibrosis in combined pulmonary fibrosis and emphysema (CPFE) in Japanese patients

The dominant pathogenesis underlying the combined pulmonary fibrosis and emphysema (CPFE) remains unresolved. The receptor for advanced glycation end-products (RAGE) is highly expressed in lung tissues and interacts with distinct multiple ligands, implicating it in certain lung diseases. To elucidate the pathogenesis of CPFE, we genotyped three single nucleotide polymorphisms (SNPs: rs2070600, rs1800625, and rs2853807) of the gene encoding RAGE (AGER) in 111 CPFE patients and 337 chronic obstructive pulmonary disease (COPD) patients of Japanese by using StepOne Real-Time PCR System for SNP genotyping assay. Serum levels of soluble RAGE (sRAGE) were measured by ELISA. We found that the allele frequency of rs2070600 was significantly different between the two groups [corrected P (Pc) = 0.015]. In addition, the minor allele was associated with CPFE patients relative to COPD patients in a dominant effect model (Odds Ratio = 1.93; Pc = 0.018). Moreover, the serum sRAGE level was significantly lower in the CPFE group than the COPD group (P = 0.014). The rs2070600 minor allele was significantly associated with reduced sRAGE level in CPFE patients and independently affected sRAGE level reduction in this group (P = 0.020). We concluded that the AGER rs2070600 minor allele (Gly82Ser mutation) is associated with the pathogenesis of pulmonary fibrosis in CPFE in Japanese patients.

Association of RAGE gene multiple variants with the risk for COPD and asthma in northern Han Chinese

Clinical and experimental data have shown that the receptor for advanced glycation end products (RAGE) is implicated in the pathogenesis of respiratory disorders. In this study, we genotyped five widely-evaluated variants in RAGE gene, aiming to assess their association with the risk for chronic obstructive pulmonary disease (COPD) and asthma in northern Han Chinese. Genotypes were determined in 105 COPD patients, 242 asthma patients and 527 controls. In single-locus analysis, there was significant difference in the genotype distributions of rs1800624 between COPD patients and controls (p=0.022), and the genotype and allele distributions of rs1800625 differed significantly (p=0.040 and 0.016) between asthma patients and controls. Haplotype analysis revealed that haplotype T-A-G-T (allele order: rs1800625, rs1800624, rs2070600, rs184003) was significantly associated with a reduced COPD risk (OR=0.32, 95% CI: 0.06-0.60), and haplotype T-A-A-G was significantly associated with a reduced asthma risk (OR=0.19, 95% CI: 0.04-0.96). Further haplotype-phenotype analysis showed that high- and low-density lipoprotein cholesterol and blood urea nitrogen were significant mediators for COPD (p_sim=0.041, 0.043 and 0.030, respectively), and total cholesterol was a significant mediator for asthma (p_sim=0.009). Taken together, our findings indicate that RAGE gene is a promising candidate for COPD and asthma, and importantly both disorders are genetically heterogeneous.

Identification of novel advanced glycation end products receptor gene variants associated with colorectal cancer in Tunisians: A case-control study

A central role for advanced glycation end products (AGE) and their receptor (RAGE) in the pathogenesis of multiple cancer types, including colorectal cancer (CRC) was reported. We investigated the association between CRC and rs2853807, rs77170610, rs184003, rs1035798, rs2070600, rs1800684, rs1800624, and rs1800625 RAGE gene (AGER) polymorphic variants. Study subjects comprised 293 CRC patients [186 colon cancer (CC) and 107 rectal cancer (RC)] patients), and 264 age-, gender-, BMI-, and ethnicity-matched controls. Minor allele frequency (MAF) of rs77170610 and rs1800625 were significantly lower, while MAF of rs1035798 was significantly higher in CRC patients compared to control subjects, which was associated with reduced and increased risk of CRC, respectively; MAF of the remaining variants was comparable between CRC patients and controls. Significant difference in the distribution of rs2853807 and rs77170610 genotypes was seen between CRC patients and controls, with both variants associated with decreased risk of CRC. Comparison of the distribution of minor allele-carrying genotypes in CC and RC patient subgroups revealed lack of significant difference in the distribution of these genotypes between the patient subgroups. In view of the lack of LD between rs2853807 and rs77170610 with other variants, six-locus (rs184003, rs1035798, rs2070600, rs1800684, rs1800624, rs1800625) haplotypes were constructed. Haplotype analysis did not identify any specific 6-locus AGER haplotype associated with CRC. In conclusion, AGER gene rs2853807 and rs77170610 variants rs77170610 are associated with altered risk of CRC in Tunisians, but with no discrimination between CC and RC types.

Effect of AGER on the biological behavior of non‑small cell lung cancer H1299 cells

Advanced glycosylation end-product specific receptor (AGER) is a multi-ligand cell surface receptor abnormally expressed in lung cancer, and is a member of the immunoglobulin superfamily. Therefore, this study aimed to explore the effect of AGER on the biological behavior of non-small cell lung cancer (NSCLC) H1299 cell line. A microarray-based gene expression profiling analysis of the GSE27262 dataset from the Gene Expression Omnibus (GEO) database was conducted to identify differentially expressed genes, which were verified using The Cancer Genome Atlas (TCGA) database. The expression of AGER in the normal human lung BEAS-2B cell line and NSCLC H1299 cell line was examined using reverse transcription-quantitative PCR. Lentiviral interference and overexpression vectors of AGER were constructed and transfected into H1299 cells using Lipofectamine^®. AGER expression and biological properties, including cell viability, apoptosis, migration and invasion abilities, in H1299 cells were investigated using MTT, flow cytometry, wound healing and Transwell assays. AGER was expressed at a low level in NSCLC tissues and H1299 cells (P<0.05). Compared with control cells, AGER overexpression cells displayed decreased cell viability, proliferation, migration and invasion abilities, and significantly increased levels of apoptosis. Furthermore, AGER overexpression increased the expression of Bax and decreased the expression of Bcl-2 in H1299 cells (P<0.05), and AGER knockdown displayed the opposite effects on H1299 cells. Therefore, AGER overexpression decreased the proliferation, invasion and migration abilities of H1299 cells, and increased apoptosis. The present study suggested that AGER might serve as a potential molecular marker for NSCLC.

Receptor for advanced glycation end products modulates oxidative stress and mitochondrial function in the soleus muscle of mice fed a high-fat diet

Accumulation of advanced glycation end products (AGEs) and activation of the receptor for AGEs (RAGE) are implicated in the progression of pathologies associated with aging, chronic inflammation, diabetes, and cellular stress. RAGE activation is also implicated in cardiovascular complications of type 2 diabetes, such as nephropathy, retinopathy, accelerated vascular diseases, and cardiomyopathy. Studies investigating the effects of AGE/RAGE axis activation on skeletal muscle oxidative stress and metabolism are more limited. We tested whether a high-fat diet (HFD) would alter circulating AGE concentration, skeletal muscle AGE accumulation, and oxidative stress in wild-type and RAGE-deficient mice. The physiological significance of AGE/RAGE axis activation in HFD-fed mice was evaluated in terms of exercise tolerance and mitochondrial respiratory chain complex activity. HFD elicited adiposity, abnormal fat distribution, and oral glucose intolerance. HFD also induced accumulation of N^ε-carboxymethyl-l-lysine, increased protein carbonyl levels, and impaired respiratory chain complex activity in soleus muscle. Ablation of RAGE had no effects on weight gain and oral glucose tolerance in HFD-fed mice. Peak aerobic capacity and mitochondrial cytochrome-c oxidase activity were restored in HFD-fed RAGE^-/- mice. We concluded that RAGE signaling plays an important role in skeletal muscle homeostasis of mice under metabolic stress. Novelty HFD in mice induces accumulation of AGEs, oxidative stress, and mitochondrial dysfunction in the soleus muscle. RAGE, the multi-ligand receptor for AGEs, modulates oxidative stress and mitochondrial electron transport chain function in the soleus muscle of HFD-fed mice.

Receptor for Advanced Glycation End Products (RAGE) and Mechanisms and Therapeutic Opportunities in Diabetes and Cardiovascular Disease: Insights From Human Subjects and Animal Models

Obesity and diabetes are leading causes of cardiovascular morbidity and mortality. Although extensive strides have been made in the treatments for non-diabetic atherosclerosis and its complications, for patients with diabetes, these therapies provide less benefit for protection from cardiovascular disease (CVD). These considerations spur the concept that diabetes-specific, disease-modifying therapies are essential to identify, especially as the epidemics of obesity and diabetes continue to expand. Hence, as hyperglycemia is a defining feature of diabetes, it is logical to probe the impact of the specific consequences of hyperglycemia on the vessel wall, immune cell perturbation, and endothelial dysfunction-all harbingers to the development of CVD. In this context, high levels of blood glucose stimulate the formation of the irreversible advanced glycation end products, the products of non-enzymatic glycation and oxidation of proteins and lipids. AGEs accumulate in diabetic circulation and tissues and the interaction of AGEs with their chief cellular receptor, receptor for AGE or RAGE, contributes to vascular and immune cell perturbation. The cytoplasmic domain of RAGE lacks endogenous kinase activity; the discovery that this intracellular domain of RAGE binds to the formin, DIAPH1, and that DIAPH1 is essential for RAGE ligand-mediated signal transduction, identifies the specific cellular means by which RAGE functions and highlights a new target for therapeutic interruption of RAGE signaling. In human subjects, prominent signals for RAGE activity include the presence and levels of two forms of soluble RAGE, sRAGE, and endogenous secretory (es) RAGE. Further, genetic studies have revealed single nucleotide polymorphisms (SNPs) of the AGER gene (AGER is the gene encoding RAGE) and DIAPH1, which display associations with CVD. This Review presents current knowledge regarding the roles for RAGE and DIAPH1 in the causes and consequences of diabetes, from obesity to CVD. Studies both from human subjects and animal models are presented to highlight the breadth of evidence linking RAGE and DIAPH1 to the cardiovascular consequences of these metabolic disorders.

Unraveling the Role of Receptor for Advanced Glycation End Products (RAGE) and Its Ligands in Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune T cell-dependent B cell-mediated disorder of the neuromuscular junction (NMJ) characterized by fluctuating skeletal muscle weakness, most commonly attributed to pathogenic autoantibodies against postsynaptic nicotinic acetylcholine receptors (AChRs). Although MG pathogenesis is well-documented, there are no objective biomarkers that could effectively correlate with disease severity or MG clinical subtypes, and current treatment approaches are often ineffective. The receptor for advanced glycation end products (RAGE) is a multiligand cell-bound receptor highly implicated in proinflammatory responses and autoimmunity. Preclinical evidence demonstrates that RAGE and its ligand S100B are upregulated in rat models of experimental autoimmune myasthenia gravis (EAMG). S100B-mediated RAGE activation has been shown to exacerbate EAMG, by enhancing T cell proinflammatory responses, aggravating T helper (Th) subset imbalance, increasing AChR-specific T cell proliferative capacity, and promoting the production of antibodies against AChRs from the spleen. Soluble sRAGE and esRAGE, acting as decoys of RAGE ligands, are found to be significantly reduced in MG patients. Moreover, MG has been associated with increased serum levels of S100A12, S100B and HMGB1. Several studies have shown that the presence of thymic abnormalities, the onset age of MG, and the duration of the disease may affect the levels of these proteins in MG patients. Herein, we discuss the emerging role of RAGE and its ligands in MG immunopathogenesis, their clinical significance as promising biomarkers, as well as the potential therapeutic implications of targeting RAGE signaling in MG treatment.

Association analysis between genomic variants within advanced glycation end product specific receptor (AGER) gene and risk of breast cancer in Iranian women

The advanced glycation end product specific receptor (AGER) gene codes for a cell surface receptor which is one of the immunoglobulin superfamily members. This gene has a number of single nucleotide polymorphisms (SNPs) whose variants are associated with altered function of the encoded protein. In the current project, we examined association between rs184003 and rs1800625 SNPs and susceptibility to breast cancer in an Iranian population. The current study excludes participation of rs184003 AGER variant in conferring cancer risk. However, for the rs1800625, based on the calculated P value, the results should be assessed in larger cohorts. Primarily, the rs1800625 SNP was associated with breast cancer risk in dominant model (OR (95% CI) = 1.79 (1.03–3.11)), but after correction for multiple comparisons it did not reach the level of significance (adjusted P value = 0.07). The other SNP was not associated with breast cancer risk in any inheritance model. Haplotype analyses revealed a trend toward association between the GC haplotype (rs184003 and rs1800625 respectively) and risk of breast cancer (OR (95% CI) = 1.77 (1.09–2.88), adjusted P value = 0.08)). The current study excludes participation of rs184003 AGER variants in conferring cancer risk. However, for the rs1800625, based on the calculated P value, the results should be assessed in larger cohorts.