Receptor For Advanced Glycation End Products Research Articles

Signal processing by extracellular DNA-sensor rageusing single molecule techniques.

Cell threat identification is critical for proper immune function. The receptor for advanced glycation end-products (RAGE) is a plasma membrane protein that detects danger by sensitizing cells to extracellular DNA. RAGE undergoes oligomerization upon DNA binding, a process potentially involved in promoting a strong cellular response to stimuli. A natural isoform of RAGE composed of the extracellular domains (RAGEex) performs an inhibitory role by competitively binding with ligands. Our study seeks to determine the mechanism and kinetics of RAGEex binding to dsDNA, as well as the role of protein oligomerization in signal detection. To have mechanical control of the DNA and to identify single molecule/particle behavior, we use correlative optical traps and confocal microscopy. Our results show fluorescently labeled RAGE binding to dsDNA. By analyzing the duration and frequency of binding events we will determine association and dissociation rates of the protein-DNA complex. We will determine oligomer size and growth by measuring the fluorescence intensity of bound protein clusters as a function of time. Our studies will provide key information to understand danger signal recognition by plasma receptors.

Blockade of receptor for advanced glycation end-products with azeliragon ameliorates streptozotocin-induced diabetic neuropathy.

Treatment options for diabetic neuropathy are suboptimal, so development of a new therapeutic strategy is urgent. We focused on the role of receptor for advanced glycation end-products (RAGE) in diabetic neuropathy. We elaborated the effects of azeliragon (orally available small-molecule antagonist of RAGE) on streptozotocin (STZ)-induced mechanical hypersensitivity in mice. A reduction in mechanical nociceptive threshold observed 28 days after STZ treatment was improved by single administration of azeliragon (10 and 30mg/kg) at 3h, but this effect disappeared at 24h. Conversely, repeat administration (three times; days 28, 30, and 32) of azeliragon (30mg/kg) enhanced the antinociceptive effect significantly compared with that obtained upon single administration, and this effect persisted at least up to 24h. The antinociceptive effect of azeliragon (30mg/kg) was almost comparable with that of pregabalin (30mg/kg). These drug treatments had no effect on blood glucose levels. Our findings suggest that RAGE might be an effective target for diabetic neuropathy treatment.

Detrimental actions of obesity-associated advanced glycation end-products on endometrial epithelial cell proliferation are alleviated by antioxidants

Advanced glycation end-products (AGE) are elevated in the uterine environment of obese infertile women. Can the detrimental effects of AGE on endometrial epithelial cells be mitigated with therapeutics, and recapitulated in a more physiologically relevant primary model (organoids)? Human endometrial epithelial cells (ECC-1) were exposed to AGE at concentrations physiologically representative of uterine fluid in lean or obese individuals, and three potential therapeutics: 25nmol/l receptor for AGE (RAGE) antagonist FPS-ZM1, 100μmol/l metformin, or a combination of antioxidants (10μmol/l N-acetyl-l-cysteine, 10μmol/l N-acetyl-l-carnitine and 5μmol/l α-lipoic acid). Real-time cell analysis (xCELLigence, ACEA Biosciences) determined the rate of adhesion and proliferation. The proliferation of organoid-derived cells and secretion of cytokines from organoids was characterized in the presence of AGE (n = 5). The uterine fluid of women undergoing assisted reproduction was profiled for AGE-associated inflammatory markers (n = 77). ECC-1 proliferation was reduced by AGE from obese versus lean conditions and vehicle control (P = 0.04 and P<0.001, respectively), and restored to a proliferation corresponding to lean conditions by antioxidants. AGE influenced organoid derived primary endometrial epithelial cell proliferation in a donor-dependent manner. AGE increased the organoid secretion of the proinflammatory cytokine CXCL16 (P = 0.006). Clinically, CXCL16 correlated positively to maternal body mass index (R = 0.264, P = 0.021) and intrauterine glucose concentration (R = 0.736, P<0.0001). Physiologically relevant concentrations of AGE alter endometrial epithelial cell function. Antioxidants restore the rate of proliferation of AGE-treated endometrial epithelial (ECC-1) cells. Primary endometrial epithelial cells, cultured as organoids, demonstrate altered proliferation and CXCL16 secretion in the presence of AGE equimolar with the uterine fluid from obese individuals.

Screening of potential pain genes in pancreatic ductal adenocarcinoma (PDAC) based on bioinformatics methods.

We aimed to identify cancer pain genes in pancreatic ductal adenocarcinoma (PDAC) using bioinformatic tools to provide evidence for pain treatment in PDAC patients. The GSE50570 data were obtained from the high-throughput Gene Expression Omnibus (GEO) database and subsequently analyzed. A volcano map, principal component analysis (PCA) map, box plot, and heat map were drawn, and a Venn diagram was constructed by comparison with human secreted histone genes. The differentially expressed secreted histone genes in PDAC were obtained. Then, Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed, followed by protein-protein interaction (PPI) network analysis and key genetic screening. In comparison to normal samples, the expression of 81 secreted protein-related genes was downregulated, and the expression of 12 secreted protein-related genes was upregulated in PDAC. According to the GO and KEGG enrichment analysis results, these differentially expressed genes are mainly involved in the PI3K-Akt signaling pathway, protein digestion and absorption, extracellular matrix (ECM) receptor interaction, AGE-RAGE (advanced glycation endproducts-the Receptor of Advanced Glycation Endproducts) signaling pathway, relaxin signaling pathway, interleukin-17 (IL-17) signaling pathway, and transforming growth factor-β (TGF-β) signaling pathway, affecting the different manifestations of PDAC cancer pain. We used Cytoscape software to construct a protein interaction network of common differentially expressed genes and obtained three clusters with high scores. Our literature review found that several genes, including PTGS2, VCAN, and CCL2, were directly related to cancer pain occurrence. By data mining the PDAC tumor expression, dozens of differentially expressed genes were identified in this study, several of which have been associated with the frequency and severity of cancer pain. This study provides an important foundation for the pain treatment of PDAC tumor patients.

RAGE contributes to allergen driven severe neutrophilic airway inflammation via NLRP3 inflammasome activation in mice.

Asthma is a major public healthcare burden, affecting over 300 million people worldwide. While there has been great progress in the treatment of asthma, subsets of patients who present with airway neutrophilia, often have more severe disease, and tend to be resistant to conventional corticosteroid treatments. The receptor for advanced glycation endproducts (RAGE) plays a central role in the pathogenesis of eosinophilic asthma, however, it's role in neutrophilic asthma remains largely uninvestigated. A mouse model of severe steroid resistant neutrophilic airway disease (SSRNAD) using the common fungal allergen Alternaria alternata (AA) was employed to evaluate the effects of genetic ablation of RAGE and pharmacological inhibition of the NLRP3 inflammasome on neutrophilic airway inflammation. AA exposure induced robust neutrophil-dominant airway inflammation and increased BALF levels of Th1/Th17 cytokines in wild-type mice, which was significantly reduced in RAGE-/- mice. Serum levels of IgE and IgG1 were increased similarly in both wild-type and RAGE-/- mice. Pharmacological inhibition of NLRP3 blocked the effects of AA exposure and NLRP3 inflammasome activation was RAGE-dependent. Neutrophil extracellular traps were elevated in the BALF of wild-type but not RAGE-/- mice and an atypical population of SiglecF+ neutrophils were identified in the BALF. Lastly, time-course studies found that RAGE expression promoted sustained neutrophil accumulation in the BALF of mice in response to AA.

Investigate the genetic mechanisms of diabetic kidney disease complicated with inflammatory bowel disease through data mining and bioinformatic analysis.

Patients with diabetic kidney disease (DKD) often have gastrointestinal dysfunction such as inflammatory bowel disease (IBD). This study aims to investigate the genetic mechanism leading to IBD in DKD patients through data mining and bioinformatics analysis. The disease-related genes of DKD and IBD were searched from the five databases of OMIM, GeneCards, PharmGkb, TTD, and DrugBank, and the intersection part of the two diseases were taken to obtain the risk genes of DKD complicated with IBD. A protein-protein interaction (PPI) network analysis was performed on risk genes, and three topological parameters of degree, betweenness, and closeness of nodes in the network were used to identify key risk genes. Finally, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the risk genes to explore the related mechanism of DKD merging IBD. This study identified 495 risk genes for DKD complicated with IBD. After constructing a protein-protein interaction network and screening for three times, six key risk genes were obtained, including matrix metalloproteinase 2 (MMP2), hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF2), interleukin (IL)-18, IL-13, and C-C motif chemokine ligand 5 (CCL5). Based on GO enrichment analysis, we found that DKD genes complicated with IBD were associated with 3,646 biological processes such as inflammatory response regulation, 121 cellular components such as cytoplasmic vesicles, and 276 molecular functions such as G-protein-coupled receptor binding. Based on KEGG enrichment analysis, we found that the risk genes of DKD combined with IBD were associated with 181 pathways, such as the PI3K-Akt signaling pathway, advanced glycation end product-receptor for AGE (AGE-RAGE) signaling pathway and hypoxia-inducible factor (HIF)-1 signaling pathway. There is a genetic mechanism for the complication of IBD in patients with CKD. Oxidative stress, chronic inflammatory response, and immune dysfunction were possible mechanisms for DKD complicated with IBD.

Wumei Wan attenuates angiogenesis and inflammation by modulating RAGE signaling pathway in IBD: Network pharmacology analysis and experimental evidence

BackgroundWumei Wan (WMW) has been used to address digestive disorder for centuries in traditional Chinese medicine. Previous studies have demonstrated its anti-colitis efficacy, but the underlying mechanism of its action remains to be further clarified. PurposeTo investigate the underlying mechanisms of WMW in the treatment of chronic ulcerative colitis (UC) through network pharmacology and experimental validation. MethodsTraditional Chinese Medicine Systems Pharmacology (TCMSP) platform were used to identify the ingredients and potential targets of WMW. The microarray gene data GSE75214 datasets from GEO database was used to define UC-associated targets. Cytoscape3.7.2 was employed to construct the protein-protein interaction (PPI) network and compounds-disease targets network. GO enrichment analysis and KEGG pathway analysis were performed by R software for functional annotation. UPLC-TOF-MS/MS method was used to quantitatively analyze the active ingredients of WMW. For experimental validation, three cycles of 2% dextran sulfate sodium salt (DSS) were used to construct chronic colitis model. The hub targets and signal pathway were detected by qPCR, ELISA, western blotting , immunohistochemical and immunofluorescence. ResultsThrough network analysis, 104 active ingredients were obtained from WMW, and 47 of these ingredients had potential targets for UC. A total of 41 potential targets of WMW and 13 hub targets were identified. KEGG analysis showed that WMW involved in advanced glycation end products-receptor of advanced glycation end products (AGE-RAGE) signaling pathway. Taxifolin, rutaecarpine, kaempferol, quercetin, and luteolin of WMW were the more highly predictive components related to the AGE-RAGE signaling pathway. In vivo validation, WMW improved DSS-induced colitis, reduced the expression of inflammatory cytokines and chemokines. Notably, it significantly decreased the mRNA expression of Spp1, Serpine1, Mmp2, Mmp9, Ptgs2, Nos2, Kdr and Icam1, which were associated with angiogenesis. In addition, we confirmed WMW inhibited RAGE expression and diminished DSS-induced epithelial barrier alterations ConclusionOur results initially demonstrated the effective components and the strong anti-angiogenic activity of WMW in experimental chronic colitis. Sufficient evidence of the satisfactory anti-colitis action of WMW was verified in this study, suggesting its potential as a quite prospective agent for the therapy of UC.

PS-B08-8: THERAPEUTIC STRATEGIES TARGETING RAGE IMPROVES RENAL OUTCOME IN LUPUS NEPHRITIS

Introduction: Lupus nephritis (LN) is present in 60% of patients with systemic lupus erythematosus (SLE). Despite of current development of immunosuppressant agents, LN still impairs the survival and quality of life in SLE patients. Receptor for advanced glycation endproducts (RAGE) is a multi-ligand receptor that belongs to the immunoglobulin superfamily, which is strongly associated with innate immune system. In the present study, we examined whether RAGE is involved in the development of LN. Further, we explored the therapeutic impact of DNA-aptamer directed against RAGE on lupus-related kidney injury. Methods: [Protocol 1] RAGE expression in kidneys and urinary RAGE excretion (uRAGE) were determined at 8, 12, 16, 18, 20-week-old by real-time PCR and ELISA, respectively in MRL/lpr, SLE-prone mice. [Protocol 2] LN was induced by peritoneally injecting pristane in wild type and RAGE globally knockout mice. [Protocol 3] MRL/lpr mice were subcutaneously administrated with DNA-aptamer raised against RAGE (RAGE-apt) or Control-aptamer (Ctrl-apt) for 10weeks. Results: [Protocol 1] uRAGE levels, but not urinary protein excretion, were significantly increased in 8-week-old MRL/lpr mice when compared to those in control MRL/MPJ mice, suggesting that uRAGE could be an early marker of LN.. Immunofluorescence staining demonstrated that RAGE was upregulated in distal tubules but not in glomerulus in 8-week-old mice. Glomerular RAGE expression was increased from 12-week-old with mesangial matrix expansion and formation of cellular crescents. RAGE expression was also found in endothelium and infiltrated macrophages in glomerulus while RAGE was merged with cathepsine D, a lysosomal aspartyl protease, and Rab7, a marker of late endocytosis in tubular epithelial cells. [Protocol 2] Pristane-induced increase in systolic blood pressure was reduced with improvement of renal dysfunction in RAGE knockouts. RAGE knockouts also showed less fibrosis with decrease in macrophage infiltration when compared to wild type mice in pristane-induced lupus nephritis. [Protocol 3] Administration of RAGE-apt ameliorated mesangial expansion, crescent formation, and macrophage infiltration into glomerulus in MRL/lpr mice. RAGE-apt, but not Ctrl-apt, reduced the level of pro-inflammatory cytokines gene expression including IL-6, TNF-α, and MCP-1 in renal cortex of MRL/lpr mice. Conclusion: RAGE could be involved in the pathogenesis of LN, and RAGE-DNA aptamer might be one of the promising therapeutic strategies for preventing the development of LN.

Soluble receptor for advanced glycation end-products (sRAGE) in childhood obesity: association with gene expression of RAGE and cardiometabolic markers.

Introduction: advanced glycation end-products (AGEs) interact with the receptor for AGEs (RAGE). Full-length RAGE is associated with intracellular signal transduction, and soluble-RAGE (sRAGE) lacks the transmembrane and cytoplasmic domains, acting as a competitive inhibitor of AGEs-RAGE binding. sRAGE levels in healthy children are associated with cell surface expression of RAGE. However, the expression of RAGE has not been explored in childhood obesity. Objective: the study aim was to evaluate the sRAGE levels and the gene expression of RAGE in children and its association with cardiometabolic markers. Methods: this is a cross-sectional study with 6-11-year children, 20 with overweight and 20 with obesity. Anthropometric measurements included waist circumference (cm) (WC), neck circumference (NC), weight (kg), fat mass (%), trunk fat (kg), muscular mass (kg), height (cm), and body mass index (BMI) (kg/m2). Blood samples following an overnight fast were collected to measure glucose (mg/dl) and lipid profile with colorimetric methods. sRAGE was determined in serum using the enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription (RT-qPCR) was performed to analyze RAGE transcripts in peripheral blood mononuclear cells isolated by Ficoll®-Hypaque. Results: we found higher RAGE (p = 0.0315) and lower sRAGE (p = 0.0305) levels in the obesity group. sRAGE level showed a negative correlation with RAGE (r = -0.35) and BMI (r = -0.24), and positive with HDL-cholesterol (r = 0.29). Regression analysis suggests that HDL-C and RAGE levels are predictors of sRAGE levels. Conclusions: expression of RAGE is associated with lower sRAGE levels in childhood obesity. Moreover, obese children show higher cardiometabolic risk markers, and a positively associated with sRAGE.

APSH-OP-2: INTRACELLULAR TRANSPORTATION OF AMYLOID BETA VIA INTERACTION BETWEEN ANGIOTENSIN II TYPE 1 RECEPTOR AND RECEPTOR OF ADVANCED GLYCATION END PRODUCTS

Objective: We recently reported that the binding of the receptor for advanced glycation end-products (RAGE) to AGE activates the G protein-coupled angiotensin II (AII) type 1 receptor (AT1) through membrane complex of the receptors (2021 Sci Rep). It has been reported that the binding of RAGE to amyloid beta is involved in the development of Alzheimer disease (AD) via processes involving intracellular transport of Amyloid beta. Here, we performed cell experiments and utilized animal models to investigate if the activation of AT1 is critically involved in Amyloid beta-RAGE-mediated cellular phenomenon, leading to the AD pathology. Design and Methods: We used CHO-cells stably transfected with either AT1 (CHO-AT1) or RAGE(CHO-RAGE), RAGE and AT1 (CHO-RAGE-AT1) and either mutation of AT1 G protein pathway(CHO-RAGE-AT1mb) or beta-arrestin pathway(CHO-RAGE-AT1 mg). Activation of Galphaq and Galphai were quantified by accumulation of IP1 and redcution of cAMP assay, respectively. Endocytosis of the Amyloid beta-RAGE complex through the AT1- beta-arrestin pathway was demonstrated by real-time imaging of the membrane dynamics of AT1 and RAGE by a spinning disk-type confocal super-resolution microscope, detection of the AT1- betaarrestin2 interaction by BRET, detection of beta-arrestin2-AP2 interaction by TR-FRET. Visualization of intracellular fluorescent Amyloid beta, and detection of intracellular aggregated Amyloid beta by PROTEOSTAT® reagent in several types of human endthelial cells and microlgilal cells. In vivo experiment, wild type and AT1 KO mice were used for analysis. Results: Using genetically modified CHO cells, we found that Amyloid beta activates Galphai, but not the Galphaq pathway of AT1, in the presence of RAGE. Furthermore, in the presence of both RAGE and AT1, we could detect and visualize Amyloid beta indcued beta-arrestin activation and endocytosis of receptors complex. We also found that inhibition of either AT1 or beta-arrestin pathway could attenuate intracellular Amyloid beta upatke and aggregation in several types of human endthelial cells and microlgilal cells. Finally, serum concentration of Amyloid beta 1–40 and Amyloid beta 1–42 was higher in AT1 knockout mice than wild type mice at 15–19 month, while the concentration of the Amyloid beta peptides in cerebrospinal fluid was equivalent between two types of mice. Conclusions: These findings indicate that Amyloid beta triggers selective G protein activation and the beta-arrestin-dependent internalization of AT1 whereby the Amyloid beta-RAGE complex undergo endocytosis. This machinery can be relevant in mice in which the deletion of AT1 led to increase in circulating Amyloid beta, implying the ablation of intracellular transporting system of Amyloid beta.

Advanced glycation end-products change placental barrier function and tight junction in rats with gestational diabetes mellitus via the receptor for advanced glycation end products/nuclear factor-κB pathway

The placenta plays an important role in nutrient transport to maintain the growth and development of the embryo. Gestational diabetes mellitus (GDM), the most common complication during pregnancy, highly affects placental function in late gestation. Advanced glycation end-products (AGEs), a complex and heterogeneous group of compounds engaged by the receptor for AGEs (RAGE), are closely associated with diabetes-related complications. In this study, AGEs induced a decrease in the expression of tight junction (TJ) proteins in BeWo cells and increased the paracellular permeability of trophoblast cells by regulating RAGE/NF-κB. Sprague-Dawley (SD) rats injected with 100 mg/kg AGEs-rat serum albumin (RSA) via the tail vein from embryo day 2 were set as the placental barrier dysfunction model group (n = 10). The effect of AGEs on placental permeability was determined using the EvansBlue dye extravasation method. The ultrastructure of the placenta samples was observed by transmission electron microscopy. The effects of AGEs on the placenta were confirmed by treating rats with RAGE antagonist FPS-ZM1 and soluble forms of RAGE (sRAGE). AGEs treatment increased placental permeability and disrupted the tight junctions in pregnant rat placenta, but has no effect on blood glucose. The expression of TJ-related proteins, including ZO-1, Occludin, and Claudin 5, were downregulated after AGEs treatment. Further, AGEs treatment increased the expression of RAGE and nuclear factor-κB in the placenta of rats and upregulated the levels of vascular endothelial growth factor. The effects of AGEs on the placenta were blocked by RAGE antagonist FPS-ZM1 and sRAGE. This study demonstrates the mechanism underlying AGEs-induced disturbance in placental function in pregnant rats and highlights the potential of AGEs in the treatment of GDM.

Determination of the effects of advanced glycation end products receptor polymorphisms and its activation on structural cell responses and inflammation in asthma.

Advanced glycation end products receptor (RAGE) is a pattern recognition receptor which attracted attention in chronic airway diseases recently. This study aimed to determine the association of RAGE with asthma and the cellular responses resulting from RAGE signaling pathway activation. Asthmatic (n = 362) and healthy (n = 134) children were genotyped by PCR-RFLP. Plasma sRAGE levels were determined by ELISA. Lung structural cells were stimulated with AGEs (advanced glycation end products) and control BSA. Expressions of cytokines and protein levels were determined by real-time PCR and ELISA. : Gly82Ser and -374 T/A polymorphisms in RAGE gene were associated with lower plasma sRAGE levels (p < 0.001 and p < 0.025, respectively). AGE stimulation increased the expression of RAGE (p = 0.002), ICAM-1 (p = 0.010) and VCAM-1 (p = 0.002) in endothelial cells; TIMP-1 (p = 0.003) and MCP-1 (p = 0.005) in fibroblasts. AGE stimulation increased protein levels of IL-6 (p < 0.001) in endothelial cells; VEGF (p = 0.025) and IL-8 (p < 0.001) in fibroblasts; IL-1b (p < 0.001) and VEGF (p = 0.007) in epithelial cells. Activation of RAGE pathway may contribute to asthma pathogenesis by increasing the expression of several asthmarelated genes. These findings suggest that suppression of RAGE signaling may be an alternative candidate for treating asthma.

Abstract IA031: AGEing and RAGEing in prostate cancer: Integrating ancestral tumor biology into the multilevel framework of health inequity constructs to inform on cancer disparity outcomes

Abstract Black/African American (AA) men have a 70% higher risk of prostate cancer (PCa) and are more than twice as likely to die of their disease as non-Hispanic White men (NHW). While the negative impacts of health inequity on PCa incidence and mortality are undeniable, ancestry specific tumor biology also plays a significant role. The circumstances and environments where individuals are born, live, work, and play, likely cause molecular changes that are synergistic or at least additive in their biological effects when combined with ancestral tumor biology. However, studies that assess how ethnic and racial disparities in health inequity constructs can exacerbate ancestry specific tumor biology are lacking. Through their ability to perpetuate a reactive stroma, this study defines the increased bioavailability of reactive metabolites called advanced glycation end products (AGEs) as a pro-tumorigenic consequence of interrelated health inequity risk factors that influence ancestry specific tumor biology. AGEs are significant because AA communities who often bear the highest cancer burden are more likely to be exposed to health inequity risk factors that greatly increase AGE exposure. For example, AAs communities often have the highest poverty rates, be more sedentary, and are more likely to live in designated food deserts. This promotes the consumption of unhealthy foods that are AGE laden, lead to weight gain, obesity, and increase cancer risk. In mice, chronic AGE consumption caused a rapid progression through prostate intra-epithelial neoplasia (p=0.049), adenocarcinoma (p=0.042) and metastatic disease (p=0.001). Mechanistically, AGEs recapitulated a regulatory program of ‘activated’ stroma similar to that observed in AA prostate tumors. Specifically, increased AGE bioavailability caused receptor for AGE (RAGE) dimerization in resident prostate fibroblasts leading to a regulatory program of immune, metabolic, and oxidative dysregulation and the downregulation of matrix regulatory proteins. Functionally, AGE treated AA-derived fibroblasts were able to increase epithelial cell migratory potential to a much greater extent than NHW-derived fibroblasts irrespective of the ancestral origin of the cocultured epithelial cells. In collaborative epidemiological studies, cancer patients in the highest quartile of past AGE consumption associated with both aggressive disease and increased all-cause mortality. The irreversible nature of AGE adducts, their association with health inequity, and their ability to impact the tumor microenvironment supports the premise that “increased AGE bioavailability contributes to the rapid tumor progression and poor outcomes observed in AA men with PCa”. AGE bioavailability provides an unexploited opportunity to consider how ethnic and racial disparities in health inequity can exacerbate ancestral tumor biology. Multidisciplinary educational, interventional, and pharmacological studies aimed at reducing AGE exposure may be viewed as novel cancer preventive and/or therapeutic initiatives. Citation Format: David P. Turner. AGEing and RAGEing in prostate cancer: Integrating ancestral tumor biology into the multilevel framework of health inequity constructs to inform on cancer disparity outcomes [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr IA031.

Genetic Polymorphism in Patients with Diabetic Nephropathy and Retinopathy: A Cross-sectional Study

Introduction: The chronic persistence of diabetes leads to microvascular complications, such as Diabetic Nephropathy (DN) and Diabetic Retinopathy (DR). Both of these are progressive disorders involving pathological changes in capillaries. A few biochemical pathways have been suggested to link hyperglycaemia and microvascular complications. The probability of developing and progressing DN and DR is associated with the duration of diabetes. These complex disorders are strongly influenced by both genetics and environmental factors. Several candidate genes have been reported to be associated with DN and DR in different populations. Aim: To determine the co-existence of DN and DR in relation to gene polymorphisms of Angiotensin-Converting Enzyme (ACE), Angiotensinogen (AGT), Receptor for Advanced Glycation End-products (RAGE), Aldose reductase (ALR2), and Vascular Endothelial Growth Factor (VEGF). Materials and Methods: The present DN and DR cross-sectional study was conducted at the Department of Endocrinology, University College of Medical Sciences, University of Delhi and GTB, New Delhi, India, and the Discipline of Biochemistry, Indira Gandhi National Open University, New Delhi, India. The study was conducted from October 2019 to August 2022. All the participants under uniform diabetes management were divided into two groups (100 in each group): Group 1 included Type-II diabetic patients with DN and DR, and Group 2 comprised Type-II diabetic patients with DN only. Polymorphisms in all genes were determined using Polymerase Chain Reaction (PCR), followed by digestion with restriction enzymes and visualisation through an ultraviolet transilluminator. The analysis of biochemical parameters and association of gene polymorphisms was performed using Statistical Package for Social Sciences (SPSS) version 26.0 software. Results: There were 57 males and 43 females in the DN+DR group, and 51 males and 49 females in the DN-DR group. The mean age of study subjects in the DN+DR group was 52.60±9.08 years, compared to the DN-DR group (47.33±10.68 years). The DN+DR group had a significantly higher mean duration of diabetes (11.78±6.86 vs. 5.13±4.78, p≤0.001) and a significantly lower mean waist circumference (91.30±13.99 vs. 95.11±9.95 cm, p≤0.02). The DN+DR group also had significantly higher urea (34.34±16.32 vs. 26.43±12.34 cm, p≤0.001), creatinine (1.34±0.90 vs. 0.89±0.25 cm, p≤0.03) and significantly lower estimated Glomerular Filtration Rate (eGFR) levels compared to the DN-DR group. The distribution of genotypes of ALR2 (p≤0.04) and VEGF genes (p≤0.001) showed a significant difference between both DN+DR and DN-DR groups. The frequency of the D allele of the VEGF gene (p≤0.02) (OR=1.94, 95% Confidence Interval (CI)=1.10-3.40) was higher in the DN+DR group. The DN+DR group also had a significantly lower frequency of the CT+TT dominant model of the ALR2 gene (p≤0.04) as well as an increased frequency of the ID+DD dominant model of the VEGF gene (p≤0.002). No significant differences were found in genotypic as well as allelic frequencies of ACE, AGT, and RAGE gene polymorphisms between the two groups. Conclusion: The D allele of the VEGF (I/D) gene polymorphism is significantly associated with DR in patients with DN. It can be concluded that the VEGF gene plays an important role in the development of retinopathy in DN patients.

PS-B12-5: THE INFLUENCE OF CELLULAR AGING ON THE MOLECULES CLEARANCE THAT UNDERGO ENDOCYTOSIS VIA AN ANGIOTENSIN II TYPE 1 RECEPTOR-DEPENDENT PATHWAY.

Objective: We recently reported that ligand binding to the receptor for advanced glycation end-products (RAGE) or oxidized LDL receptor (LOX-1) activates the G protein-coupled angiotensin II (AII) type 1 receptor (AT1) via a membrane complex of the receptor (2021 Sci Rep, 2021 iScience). The intracellular events triggered by this AT1 activation include signal transduction in a G-protein-dependent pathway and endocytosis of the ligand-receptors complex in a β;-arrestin-dependent pathway. Particularly, little is known about the significance of AT1-induced endocytosis of ligands. In this study, we used amyloid β; (A β;), a known ligand for RAGE, to examine whether cell aging affects the fate of ligands undergoing AT1-dependent endocytosis. Design and Methods: Human unvelical vascular endothelial cell (HUVEC) and human brain microvascluar endothelial cell (HBMEC) were continuously cultured to induce replicative senescence. Fluorescent A β; (FA β;) was used to visualize cellular uptake of A β;. Fluorescence/cell number was measured after 24hour application of FA β; (F0) or after 24hour application followed by 24hour washout of FA β; (F1). Clearance of A β; was culculated by (F0-F1)/F0. Cellular aggeragation of A β; was assessed by PROTEOSTAT∨ reagent. Pretreatment with lysosomal inhibitors (Chloroquine, Bafilomycin A), siRNA knockdown of AT1, or trehalose as a lysosomal activator was used if applicable. β;galactosidase assay and real time PCR of p16 mRNA were performed to quantify cellular senescence. Results: In HUVECs, pretreatment with Chloroquine or Bafilomycin A markedly decreased A β; clearance. Older HUVEC with passage 12 (P12) and older HBMEC with P20 showed higher β;-galactosidase activity and p16 expression compared with younger cells with P3 and P5, respectively. Clearance of A β; was decreased in older cells compared to younger cells in both cell types. A β; aggregation was higher in older cells than younger cells in both cell types. siRNA of AT1 prominently decreased uptake and aggregation of A β; but did not influence clearance rate of Aβ; in both types of cells. Pretreatment of trehalose significantly restored clearance of Aβ; in older HBMEC. Conclusions: These findings indicate that cellular senescence reduces the clearance of molecules that undergo endocytosis via an AT1-dependent pathway. Further investigation will be required, but impaired lysosomal function due to aging might be involved in this mechanism.

Alarmins and Related Molecules in Elective Surgery

Surgery is associated with alterations of alarmins’ and related molecules’ levels. The aim of this study was to investigate which biomarkers are most involved in surgery. The studied group consisted of 58 patients with inguinal or umbilical hernia or cholecystolithiasis and 21 healthy controls for compa­rison. We also added seven acute patients with appendicitis, cholecystitis and incarcerated hernia. Serum concentrations of soluble receptor of advanced glycation end-products (sRAGE), extracellular newly identified receptor for advanced glycation end-products binding protein (EN-RAGE), calprotectin, high mobility group box 1 (HMGB1) and interleukin 6 (IL-6) were analysed by ELISA before and after surgery. Preoperative concentrations of calprotectin were significantly decreased while concentrations of sRAGE were significantly increased in patients compared to controls; the concentrations of EN-RAGE and HMGB1 did not differ significantly. IL-6 levels were undetectable in elective patients preoperatively and in controls. Postoperatively, there was a significant increase of EN-RAGE, calprotectin, HMGB1, and IL-6 and a significant decrease of sRAGE compared to preoperative levels. In acute patients, all tested molecules except for sRAGE were significantly increased preoperatively, and sRAGE was significantly decreased. In contrast, after surgery, we could observe a further increase in IL-6; the other biomarkers did not differ significantly. We can conclude that the concentrations of all tested biomarkers are significantly influenced by elective surgery. The postoperative levels of all tested molecules increase except for sRAGE, whose level is significantly decreased after surgery. In acute states, these molecules are already increased, and the influence of surgery is, apart from IL-6, insignificant.

A systematic review and meta-analysis of the relationship between advanced glycation end products ceceptor (RAGE) gene polymorphisms and the risk of inflammatory bowel disease.

In the pathogenesis of inflammatory bowel disease (IBD), the advanced glycation end product receptor (RAGE) has been involved. IBD is classified into Chron's disease (CD) and ulcerative colitis (UC). The promoter gene of the RAGE gene was discovered to have had unique polymorphisms that increased its transcriptional activity. This study, therefore, used a systematic review and meta-analysis to examine the relationship between the RAGE gene polymorphism and the risk of IBD. Databases such as PubMed, Scopus, and Cochrane library were searched to identify the relationship between RAGE gene polymorphisms and IBD susceptibility. We identified three Single Nucleotide Polymorphism (SNPs) (RAGE-429T/C, 374T/A, and G82S). The data were analyzed by RevMan 5.4. Four studies (932 cases/1366 controls) were included. The findings showed no relationship between RAGE -429T/C and -G82S polymorphisms and the risk of IBD in all genetic models significantly. TT genotype of RAGE -374T/A polymorphisms was related to increased CD risk (OR=1.37; 95%CI=1.04-1.81; P=0.02), while TA genotype was determined to be a protective factor (OR=0.75; 95%CI=0.57-0.99; P=0.04). In UC, A allele of RAGE -374T/A was related to increase risk (OR=1.26; 95%CI=1.04-1.53; P=0.02), while T allele was determined to decrease risk (OR=0.79; 95%CI= 0.65-0.96; P=0.02). Our findings demonstrated that TT genotype and A allele of RAGE -374T/A polymorphisms were related to CD and UC risks, respectively, while the TA genotype and T allele possibly had a protective effect. RAGE -429T/C and RAGE -G82S polymorphisms were not related to increased IBD risk.

Inter-rater reliability and prognostic value of baseline Radiographic Assessment of Lung Edema (RALE) scores in observational cohort studies of inpatients with COVID-19

ObjectivesTo reliably quantify the radiographic severity of COVID-19 pneumonia with the Radiographic Assessment of Lung Edema (RALE) score on clinical chest X-rays among inpatients and examine the prognostic value of...

Advanced Glycation End Products-Induced Activation of Keratinocytes: A Mechanism Underlying Cutaneous Immune Response in Psoriasis

Psoriasis is a common inflammatory skin disease, in which epidermal keratinocytes play a vital role in its pathogenesis by acting both as the responder and as the accelerator to the cutaneous psoriatic immune response. Advanced glycation end products (AGEs) are a class of proinflammatory metabolites that are commonly accumulating in cardiometabolic disorders. Recent studies have also observed the increased level of AGEs in the serum and skin of psoriasis patients, but the role of AGEs in psoriatic inflammation has not been well investigated. In the present study, we initially detected abnormal accumulation of AGEs in epidermal keratinocytes of psoriatic lesions collected from psoriasis patients. Furthermore, AGEs promoted the proliferation of keratinocytes via upregulated Keratin 17 (K17)-mediated p27KIP1 inhibition followed by accelerated cell cycle progression. More importantly, AGEs facilitated the production of interleukin-36 alpha (IL-36α) in keratinocytes, which could enhance T helper 17 (Th17) immune response. In addition, the induction of both K17 and IL-36α by AGEs in keratinocytes was dependent on the activation of signal transducer and activator of transcription 1/3 (STAT1/3) signaling pathways. At last, the effects of AGEs on keratinocytes were mediated by the receptor for AGEs (RAGE). Taken together, these findings support that AGEs potentiate the innate immune function of keratinocytes, which contributes to the formation of psoriatic inflammation. Our study implicates AGEs as a potential pathogenic link between psoriasis and cardiometabolic comorbidities.

Exploring the Mechanism of White Peony in the Treatment of Lupus Nephritis Based on Network Pharmacology and Molecular Docking.

Lupus nephritis (LN) is still a great burden for patients with systemic lupus erythematosus, and also one of the most severe complications of SLE. Radix Paeoniae Alba (white peony, WP) is proved with potential efficacy in treating LN. This study was to explore the effective ingredients, potential targets, and pathways of WP in treating LN based on network pharmacology and molecular docking. The active ingredients and potential protein targets of WP were gathered on Traditional Chinese Medicine Systematic Pharmacology Database and predicted by Swiss Target Prediction. LN-related therapeutic targets were acquired from multiple databases including Genecards, DisGeNET, OMIM, Drugbank, and PharmGKB. The intersection targets of WP and LN were acquired through Veeny 2.1.0. Protein-Protein Interaction (PPI) network was established by STRING. The results were then visualized by Cytoscape version 3.7.1. to study the mechanisms of WP on LN, gene ontology and functional enrichment analysis were carried out. Finally, molecular docking presented with the binding ability of key targets and major active components. We acquired a total of 13 active ingredients and 260 potential targets of WP. Among them, the intersection with targets of LN were 82 proteins. These targets were regarded as potential therapeutic targets. Through PPI network, we found that the top three proteins were RAC-alpha serine/threonine protein kinase (AKT1), vascular endothelial growth factor A (VEGFA), and transcription factor Jun (JUN), and their corresponding components were kaempferol, paeoniflorin, lactiflorin, paeoniflorgenone, etc. The results of enrichment analysis suggested that WP treatment for LN mainly involves in signaling pathways in cancer, lipid and atherosclerosis, advanced glycation end product (AGE)-receptor of AGE (RAGE) pathways, C-type lectin receptor and nuclear factor (NF)-kappa B signaling pathways. Molecular docking predicted that the above components have excellent affinity to AKT1, VEGFA, and JUN. This study gave an insight into the key target proteins and potential underlying pharmacological mechanism of WP in treating LN, which provided evidence for further researches on the mechanism of WP on LN.