Explore the vast range of titles available.

The Receptor for Advanced Glycation End-products (RAGE) is a multi-ligand receptor present on most cell types. Upregulation of RAGE is seen in a number of pathological states including, inflammatory and vascular disease, dementia, diabetes and various cancers. We previously demonstrated that alternative splicing of the RAGE gene is an important mechanism which regulates RAGE signaling through the production of soluble ligand decoy isoforms. However, no studies have identified any alternative splice variants within the intracellular region of RAGE, a region critical for RAGE signaling. Herein, we have cloned and characterized a novel splice variant of RAGE that has a truncated intracellular domain (RAGEΔICD). RAGEΔICD is prevalent in both human and mouse tissues including lung, brain, heart and kidney. Expression of RAGEΔICD in C6 glioma cells impaired RAGE-ligand induced signaling through various MAP kinase pathways including ERK1/2, p38 and SAPK/JNK. Moreover, RAGEΔICD significantly affected tumor cell properties through altering cell migration, invasion, adhesion and viability in C6 glioma cells. Furthermore, C6 glioma cells expressing RAGEΔICD exhibited drastic inhibition on tumorigenesis in soft agar assays. Taken together, these data indicate that RAGEΔICD represents a novel endogenous mechanism to regulate RAGE signaling. Significantly, RAGEΔICD could play an important role in RAGE related disease states through down regulation of RAGE signaling.

Endothelial dysfunction is a key triggering event in atherosclerosis. Following the entry of lipoproteins into the vessel wall, their rapid modification results in the generation of advanced glycation endproduct epitopes and subsequent infiltration of inflammatory cells. These inflammatory cells release receptor for advanced glycation endproduct (RAGE) ligands, specifically S100/calgranulins and high-mobility group box 1, which sustain vascular injury. Here, we demonstrate critical roles for RAGE and its ligands in vascular inflammation, endothelial dysfunction, and atherosclerotic plaque development in a mouse model of atherosclerosis, apoE-/- mice. Experiments in primary aortic endothelial cells isolated from mice and in cultured human aortic endothelial cells revealed the central role of JNK signaling in transducing the impact of RAGE ligands on inflammation. These data highlight unifying mechanisms whereby endothelial RAGE and its ligands mediate vascular and inflammatory stresses that culminate in atherosclerosis in the vulnerable vessel wall.

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic cancer subtype, which is generally untreatable once it metastasizes. We hypothesized that interfering with the Receptor for Advanced Glycation End-products (RAGE) signaling with the small molecule RAGE inhibitors (TTP488/Azeliragon and FPS-ZM1) would impair TNBC metastasis and impair fundamental mechanisms underlying tumor progression and metastasis. Both TTP488 and FPS-ZM1 impaired spontaneous and experimental metastasis of TNBC models, with TTP488 reducing metastasis to a greater degree than FPS-ZM1. Transcriptomic analysis of primary xenograft tumor and metastatic tissue revealed high concordance in gene and protein changes with both drugs, with TTP488 showing greater potency against metastatic driver pathways. Phenotypic validation of transcriptomic analysis by functional cell assays revealed that RAGE inhibition impaired TNBC cell adhesion to multiple extracellular matrix proteins (including collagens, laminins, and fibronectin), migration, and invasion. Neither RAGE inhibitor impaired cellular viability, proliferation, or cell cycle in vitro. Proteomic analysis of serum from tumor-bearing mice revealed RAGE inhibition affected metastatic driver mechanisms, including multiple cytokines and growth factors. Further mechanistic studies by phospho-proteomic analysis of tumors revealed RAGE inhibition led to decreased signaling through critical BC metastatic driver mechanisms, including Pyk2, STAT3, and Akt. These results show that TTP488 impairs metastasis of TNBC and further clarifies the signaling and cellular mechanisms through which RAGE mediates metastasis. Importantly, as TTP488 displays a favorable safety profile in human studies, our study provides the rationale for evaluating TTP488 in clinical trials to treat or prevent metastatic TNBC.

Control over cell engraftment, survival, and function remains critical for heart repair. We have established a tissue engineering platform for the delivery of human mesenchymal progenitor cells (MPCs) by a fully biological composite scaffold. Specifically, we developed a method for complete decellularization of human myocardium that leaves intact most elements of the extracellular matrix, as well as the underlying mechanical properties. A cell-matrix composite was constructed by applying fibrin hydrogel with suspended cells onto decellularized sheets of human myocardium. We then implanted this composite onto the infarct bed in a nude rat model of cardiac infarction. We next characterized the myogenic and vasculogenic potential of immunoselected human MPCs and demonstrated that in vitro conditioning with a low concentration of TGF-β promoted an arteriogenic profile of gene expression. When implanted by composite scaffold, preconditioned MPCs greatly enhanced vascular network formation in the infarct bed by mechanisms involving the secretion of paracrine factors, such as SDF-1, and the migration of MPCs into ischemic myocardium, but not normal myocardium. Echocardiography demonstrated the recovery of baseline levels of left ventricular systolic dimensions and contractility when MPCs were delivered via composite scaffold. This adaptable platform could be readily extended to the delivery of other reparative cells of interest and used in quantitative studies of heart repair.

Breast cancer incidence and mortality increase with age, but the mechanisms linking aging to metastasis remain unclear. Most preclinical studies use young animal models, limiting insight into how the aged microenvironment influences cancer. Here, we show that aging markedly increases breast cancer metastasis in multiple mouse models, and this effect is dependent on host expression of the Receptor for Advanced Glycation End-products (RAGE). Aging increased tumor RAGE ligand levels, including S100A8/9 and AGEs, and induced RAGE-dependent changes in inflammatory, EMT, angiogenic, and extracellular matrix gene programs in tumors. Circulating cytokines and S100A8/9 from aged hosts promoted tumor cell invasion, which was suppressed by RAGE or S100A8/9 inhibition. In human breast cancers, elevated AGER expression and enrichment of aging- and RAGE-associated transcriptional signatures correlated with poorer survival, especially in older patients. These findings identify RAGE as a mechanistic link between aging and metastasis and a potential therapeutic target in older patients. RAGE activation in aged hosts amplifies inflammatory remodeling of the tumor microenvironment and promotes tumor dissemination.

Effects of Novel Polymorphisms in the RAGE Gene on Transcriptional Regulation and Their Association With Diabetic Retinopathy Barry I. Hudson , Max H. Stickland , T. Simon Futers and Peter J. Grant Academic Unit of Molecular Vascular Medicine, University of Leeds, Leeds General Infirmary, Leeds, U.K. Abstract Interactions between advanced glycation end products (AGEs) and the receptor for AGE (RAGE) are implicated in the vascular complications in diabetes. We have identified eight novel polymorphisms, of which the −1420 (GGT)n, −1393 G/T, −1390 G/T, and −1202 G/A were in the overlapping PBX2 3′ untranslated region (UTR), and the −429 T/C (66.5% TT, 33.5% TC/CC), −407 to –345 deletion (99% I, 1% I/D, 0% D), −374 T/A (66.4% TT, 33.6% TA/AA), and +20 T/A were in the RAGE promoter. To evaluate the effects on transcriptional activity, we measured chloramphenicol acetyl transferase (CAT) reporter gene expression, driven by variants of the –738 to +49 RAGE gene fragment containing the four polymorphisms identified close to the transcriptional start site. The –429 C, −374 A, and 63-bp deletion alleles resulted in a mean increase of CAT expression of twofold ( P < 0.0001), threefold ( P < 0.001), and fourfold ( P < 0.05), respectively, with the –374 T and A alleles yielding highly differential binding of nuclear protein extract from both monocyte- and hepatocyte-derived cell lines. The prevalence of the functional polymorphisms were investigated in subjects with type 2 diabetes (106 with and 109 without retinopathy), with the –429 C allele showing an increase in the retinopathy group ( P < 0.05). These data suggest that the polymorphisms involved in differences in RAGE gene regulation may influence the pathogenesis of diabetic vascular complications. Footnotes Address correspondence and reprint requests to Dr Barry I. Hudson, Academic Unit of Molecular Vascular Medicine, Research School of Medicine, G Floor, Martin Wing, Leeds General Infirmary, Leeds, LS1 3EX, UK. E-mail: b.hudson{at}leeds.ac.uk . Received for publication 30 May 2000 and accepted in revised form 2 March 2001. AGE, advanced glycation end products; CAT, chloramphenicol acetyl transferase; DHPLC, denaturing high-performance liquid chromatography; EMSA, electrophoretic mobility shift assays; PCR, polymerase chain reaction; RAGE, receptor for AGE; RFLP, restriction fragment–length polymorphism; SSCP, single-strand conformation polymorphism; TEAA, tri-ethyl ammonium acetate; UTR, untranslated region.

The Functional −374 T/A RAGE Gene Polymorphism Is Associated With Proteinuria and Cardiovascular Disease in Type 1 Diabetic Patients Kim Pettersson-Fernholm 1 2 , Carol Forsblom 1 2 , Barry I. Hudson 3 4 , Markus Perola 5 6 , Peter J. Grant 3 , Per-Henrik Groop 1 2 and for the FinnDiane Study Group 1 Department of Medicine, Division of Nephrology, Helsinki University Central Hospital, Helsinki, Finland 2 Folkhälsan Research Centre, University of Helsinki, Helsinki, Finland 3 Academic Unit of Molecular Vascular Medicine, University of Leeds, Leeds General Infirmary, Leeds, U.K. 4 Department of Surgery, Columbia University, New York, New York 5 Department of Molecular Medicine, National Public Health Institute, Biomedicum, Helsinki, Finland 6 Department of Genetics, University of California, Los Angeles, California Abstract The hyperglycemic milieu in diabetes results in the formation of advanced glycation end products (AGEs) that predominantly act through specific receptors, particularly the receptor for AGEs (RAGE). Two functional polymorphisms in the promoter of the RAGE gene (−429 T/C and −374 T/A) and one in the AGE binding domain in exon 3 (G82S) were studied in 996 Finnish type 1 diabetic patients. In patients with poor metabolic control (HbA 1c >9.5%), the AA genotype of the −374 T/A polymorphism was more common in those with a normal albumin excretion rate than in those with proteinuria (30 vs. 10%, P = 0.01). We observed less coronary heart disease (6 vs. 14%, P < 0.05), acute myocardial infarction (2 vs. 14%, P = 0.01), and peripheral vascular disease (2 vs. 14%, P < 0.05) in patients with the AA genotype of the −374 T/A polymorphism than in those with the TT + TA genotype. Thus, the association between the RAGE −374 T/A homozygous AA genotype and cardiovascular disease as well as albumin excretion in type 1 diabetic patients with poor metabolic control suggests a gene-environment interaction in the development of diabetic nephropathy and cardiovascular complications. Footnotes Address correspondence and reprint requests to Per-Henrik Groop, Folkhälsan Research Center, Biomedicum Helsinki, Haartmaninkatu 8 (C318b), POB 63, FIN-00014, University of Helsinki, Helsinki, Finland. E-mail: per-henrik.groop{at}folkhalsan.fi . Received for publication 24 June 2002 and accepted in revised form 19 November 2002. AER, albumin excretion rate; AGE, advanced glycation end product; AMI, acute myocardial infarction; CHD, coronary heart disease; CVD, cardiovascular disease; ESRD, end-stage renal disease; PVD, peripheral vascular disease; RAGE, receptor for AGEs; RIA, radioimmunoassay. † † Deceased. DIABETES

We hypothesized that Hispanic/Latino youth at high risk for diabetes would have elevated biomarkers of endothelial dysfunction. Among 1316 children 8–16years old from the Study of Latino Youth (SOL Youth), we used Poisson regression to obtain prevalence ratios (PRs) and 95% CIs for the cross-sectional association of quartiles of fasting glucose, HbA1c, and insulin resistance with E-selectin and plasminogen activator inhibitor-1 (PAI-1) levels above the median (≥48.1 and ≥2.02ng/mL, respectively). Levels of E-selectin and PAI-1 were higher in children who were obese or had higher levels of hs-CRP (p<0.05). Insulin resistance was independently associated with higher levels of PAI-1 (adjusted PR and 95% CI for the highest versus lowest quartile (Q4 vs Q1): 2.25 [1.64, 3.09]). We found stronger evidence of associations of insulin resistance with higher levels of PAI-1 among boys as compared with girls (p-interaction = 0.10). Insulin resistance was associated with endothelial dysfunction, as measured by higher levels of PAI-1, in Hispanic/Latino youth. These biomarkers may be useful in risk stratification and prediction of diabetes and cardiovascular disease in high-risk youth.