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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Advanced glycosylation end products of proteins (AGEs) are nonenzymatically glycosylated proteins which accumulate in vascular tissue in aging and at an accelerated rate in diabetes. A approximately 35-kDa polypeptide with a unique NH2-terminal sequence has been isolated from bovine lung and found to be present on the surface of endothelial cells where it mediates the binding of AGEs (receptor for advanced glycosylation end product or RAGE). Using an oligonucleotide probe based on the amino-terminal sequence of RAGE, an apparently full-length cDNA of 1.5 kilobases was isolated from a bovine lung cDNA library. This cDNA encoded a 394 amino acid mature protein comprised of the following putative domains: an extracellular domain of 332 amino acids, a single hydrophobic membrane spanning domain of 19 amino acids, and a carboxyl-terminal domain of 43 amino acids. A partial clone encoding the human counterpart of RAGE, isolated from a human lung library, was found to be approximately 90% homologous to the bovine molecule. Based on computer analysis of the amino acid sequence of RAGE and comparison with databases, RAGE is a new member of the immunoglobulin superfamily of cell surface molecules and shares significant homology with MUC 18, NCAM, and the cytoplasmic domain of CD20. Expression of the RAGE cDNA in 293 cells allowed them to bind 125I-AGE-albumin in a saturable and dose-dependent manner (Kd approximately 100 nM), blocked by antibody to RAGE. Western blots of 293 cells transfected with RAGE cDNA probed with anti-RAGE IgG demonstrated expression of immunoreactive protein compared to its absence in mock-transfected cells. These results suggest that RAGE functions as a cell surface receptor for AGEs, which could potentially mediate cellular effects of this class of glycosylated proteins.
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PMID:Cloning and expression of a cell surface receptor for advanced glycosylation end products of proteins. 137 43

Vascular cell adhesion molecule-1 (VCAM-1), an inducible cell-cell recognition protein on the endothelial cell surface (EC), has been associated with early stages of atherosclerosis. In view of the accelerated vascular disease observed in patients with diabetes, and the enhanced expression of VCAM-1 in diabetic rabbits, we examined whether irreversible advanced glycation endproducts (AGEs), could mediate VCAM-1 expression by interacting with their endothelial cell receptor (receptor for AGE, RAGE). Exposure of cultured human ECs to AGEs induced expression of VCAM-1, increased adhesivity of the monolayer for Molt-4 cells, and was associated with increased levels of VCAM-1 transcripts. The inhibitory effect of anti-RAGE IgG, a truncated form of the receptor (soluble RAGE) or N-acetylcysteine on VCAM-1 expression indicated that AGE-RAGE-induced oxidant stress was central to VCAM-1 induction. Electrophoretic mobility shift assays on nuclear extracts from AGE-treated ECs showed induction of specific DNA binding activity for NF-kB in the VCAM-1 promoter, which was blocked by anti-RAGE IgG or N-acetylcysteine. Soluble VCAM-1 antigen was elevated in human diabetic plasma. These data are consistent with the hypothesis that AGE-RAGE interaction induces expression of VCAM-1 which can prime diabetic vasculature for enhanced interaction with circulating monocytes.
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PMID:Advanced glycation endproducts interacting with their endothelial receptor induce expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured human endothelial cells and in mice. A potential mechanism for the accelerated vasculopathy of diabetes. 754 3

Erythrocyte-endothelial cell interactions were rediscovered using endothelial cells in culture and radiolabelled erythrocytes. Increased adherence of erythrocytes from patients with sickle cell anaemia was found to be related to the occurrence of vaso-occlusive episodes. In diabetes mellitus and sickle cell anaemia, the adhesion was shown to be potentiated by plasmatic factors such as fibrinogen and fibronectin and to induce endothelial cell activation and enhanced prostacyclin production. The molecular basis of the abnormal adherence of diabetic erythrocytes was shown to be linked to Advanced Glycosylated End-products (AGE) present on the cell membrane and to RAGE 35 receptors exposed by the endothelium. Intercellular Adhesion Molecule (ICAM) was identified as an ubiquitous receptor present on endothelium and involved in leucocyte adhesion and it was more recently demonstrated that erythrocytes infested by Plasmodium falciparum bind to ICAM. This adhesion may be important for the dissemination of Plasmodium falciparum and the complications of the disease. In summary, interactions between endothelium and erythrocytes appear to be involved in the pathophysiology of a number of affections and could constitute a new therapeutic target.
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PMID:Adhesion of erythrocytes to endothelium in pathological situations: a review article. 797 Dec 46

Nonenzymatic glycation of proteins occurs at an accelerated rate in diabetes and can lead to the formation of advanced glycation end products of proteins (AGEs), which bind to mononuclear phagocytes (MPs) and induce chemotaxis. We have isolated two cell surface-associated binding proteins that mediate the interaction of AGEs with bovine endothelial cells. One of these proteins is a new member of the immunoglobulin superfamily of receptors (termed receptor for AGEs or RAGE); and the second is a lactoferrin-like polypeptide (LF-L). Using monospecific antibodies to these two AGE-binding proteins, we detected immunoreactive material on Western blots of detergent extracts from human MPs. Radioligand-binding studies demonstrated that antibody to the binding proteins blocked 125I-AGE-albumin binding and endocytosis by MPs. Chemotaxis of human MPs induced by soluble AGE-albumin was prevented in a dose-dependent manner by intact antibodies raised to the AGE-binding proteins, F(ab')2 fragments of these antibodies and by soluble RAGE. When MP migration in response to N-formyl-Met-Leu-Phe was studied in a chemotaxis chamber with AGE-albumin adsorbed to the upper surface of the chamber membrane, movement of MPs to the lower compartment was decreased because of interaction of the glycated proteins with RAGE and LF-L on the cell surface. The capacity of AGEs to attract and retain MPs was shown by implanting polytetrafluoroethylene (PTFE) mesh impregnated with AGE-albumin into rats: within 4 d a florid mononuclear cell infiltrate was evident in contrast to the lack of a significant cellular response to PTFE with adsorbed native albumin. These data indicate that RAGE and LF-L have a central role in the interaction of AGEs with human mononuclear cells and that AGEs can serve as a nidus to attract MPs in vivo.
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PMID:Regulation of human mononuclear phagocyte migration by cell surface-binding proteins for advanced glycation end products. 838 41

Long-term incubation of proteins with glucose leads to advanced glycation end products (AGEs) with fluorescence and a brown color. We recently demonstrated immunologically the intracellular AGE accumulation in smooth muscle cell (SMC)-derived foam cells in advanced atherosclerotic lesions. To understand the mechanism of AGE accumulation in these foam cells, we have now characterized the interaction of AGE proteins with rabbit-cultured arterial SMCs. In experiments at 4 degrees C, 125I-labeled AGE-bovine serum albumin (AGE-BSA) showed a dose-dependent saturable binding to SMCs with an apparent dissociation constant (Kd) of 4.0 microg/ml. In experiments at 37 degrees C, AGE-BSA underwent receptor-mediated endocytosis and subsequent lysosomal degradation. The endocytic uptake of 125I-AGE-BSA was effectively inhibited by unlabeled AGE proteins such as AGE-BSA and AGE-hemoglobin, but not by acetylated LDL and oxidized LDL, well-known ligands for the macrophage scavenger receptor (MSR). Moreover, the binding of 125I-AGE-BSA to SMCs was affected neither by amphoterin, a ligand for one type of the AGE receptor, named RAGE, nor by 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole-hexanoic acid-BSA, a ligand for the other AGE receptors, p60 and p90. This indicates that the endocytic uptake of AGE proteins by SMCs is mediated by an AGE receptor distinct from MSR, RAGE, p60, and p90. To examine the functional role of this AGE receptor, the migratory effects of AGE-BSA on these SMCs were tested. Incubation with 1-50 microg/ml of AGE-BSA for 14 h resulted in significant dose-dependent cell migration. The AGE-BSA-induced SMC migration was chemotactic in nature and was significantly inhibited (approximately 80%) by an antibody against transforming growth factor-beta (TGF-beta), and the amount of TGF-beta secreted into the culture medium from SMC by AGE-BSA was sevenfold higher than that of control, indicating that TGF-beta is involved in the AGE-induced SMC chemotaxis. These data suggest that AGE may play a role in SMC migration in advanced atherosclerotic lesions.
Diabetes 1997 Mar
PMID:The receptor for advanced glycation end products mediates the chemotaxis of rabbit smooth muscle cells. 903 4

Formation and deposition of advanced glycation end-products (AGEs) has been linked to late diabetic complications. Interactions of AGEs are at least partly mediated by binding of AGEs to their cellular surface receptor RAGE. This review summarizes the immunohistological data obtained for RAGE distribution in vessel segments of diabetic and non-diabetic patients with peripheral occlusive vascular disease and in kidneys of patients with diabetic nephropathy, and inflammatory and non-inflammatory renal disease. It is demonstrated that increased RAGE expression is not restricted to diabetes mellitus but contributes to a range of vascular and renal disorders.
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PMID:Expression of receptors for advanced glycation end-products in occlusive vascular and renal disease. 904 15

The formation of advanced glycation end products (AGEs) is observed in conditions such as diabetes mellitus and ageing, both associated with vascular disorders. AGEs form by the interaction of an aldose with NH2 of proteins, and the subsequent Amadori rearrangement leads to complex molecules. The heterogeneous class of AGE molecules is found in plasma, cells and tissues and accumulates in the vessel wall and the kidney. AGE reactions can generate reactive oxygen intermediates (ROIs), which can act as signal mediators and can be deleterious for molecules or cells. The AGEs and ROI-induced cellular dysfunctions can interfere with the gene expression of peptides and cytokines regulating cell proliferation and vascular functions. The interaction of AGEs with the AGE receptor (RAGE) is followed by a series of intracellular modifications that may be involved in the development of atherosclerosis. An attempt to minimize AGE formation and to limit ROI production by an appropriate therapy may result in the reduction or slowing of vascular disease in patients with diabetes mellitus.
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PMID:Advanced glycation end products, oxidant stress and vascular lesions. 906 2

Vascular dysfunction in patients with diabetes mellitus is related to advanced glycation end product (AGE) formation. We previously showed that AGEs produce an increase in vascular permeability and generated an oxidant stress after binding to the receptor (RAGE) present on endothelium. RAGE, a 35-kDa protein that belongs to the immunoglobulin superfamily, has been cloned from a rat lung cDNA library, and recombinant rat soluble RAGE (rR-RAGE) has been produced in insect cells. The sequence of RAGE is highly conserved between human and rat. We studied the biological effect of rR-RAGE and pharmacokinetics of 125I-rR-RAGE after intravenous or intraperitoneal administration in normal and streptozotocin-induced diabetic rats. rR-RAGE prevented albumin or inulin transfer through a bovine aortic endothelial cell monolayer, restored the hyperpermeability observed in diabetic rats or induced in normal rats by diabetic rat red blood cells, and corrected the reactive oxygen intermediate production after intravenous or intraperitoneal administration. After intravenous injection of 125I-rR-RAGE, the distribution half-life was longer (p < or = 0.01) in diabetic (0.15 and 4.01 hr) than in normal (0.02 and 0.21 hr) rats, as was the case for the elimination half-lives (diabetic, 57.17 hr; normal, 26.02 hr; p < or = 0.01). Distribution volume was higher in diabetic than in normal rats (6.94 and 3.24 liter/kg, respectively; p = 0.049). Our study showed that rR-RAGE was biologically active in vivo and slowly cleared, which suggests it could be considered as a potential therapy.
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PMID:Recombinant advanced glycation end product receptor pharmacokinetics in normal and diabetic rats. 922 12

The prevalence and severity of periodontal disease is increased in patients with both insulin-deficient and insulin-resistant forms of diabetes. While a number of underlying factors likely contribute to enhanced periodontal inflammation and alveolar bone loss in diabetes, a common characteristic of these disorders, regardless of etiology, is the presence of hyperglycemia. A critical consequence of hyperglycemia is non-enzymatic glycation and oxidation of proteins and lipids. After a series of reversible reactions which lead to the generation of Schiff bases/Amadori products, a further series of complex molecular rearrangements ensues which results in the formation of the irreversible advanced glycation end products, or AGEs. AGEs accumulate during the process of normal aging in the plasma and tissues, but to an accelerated degree in patients with diabetes. A central means by which AGEs are believed to impart their pathogenic effects is via interaction with specific cellular receptors; the best-characterized of these is receptor for AGE, or RAGE. RAGE, a member of the immunoglobulin superfamily of cell surface molecules, is present in increased levels on target cells in diabetes, such as endothelial cells and monocytes. One consequence of AGE-RAGE interaction is the generation of enhanced cellular oxidant stress, a means by which cell signaling pathways may be activated, thereby resulting in altered cellular phenotype and cellular dysfunction. In this report, we will review our studies to date on AGEs and RAGE and consider the implications of their enhanced interaction in the pathogenesis of accelerated periodontal disease in diabetes.
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PMID:Enhanced interaction of advanced glycation end products with their cellular receptor RAGE: implications for the pathogenesis of accelerated periodontal disease in diabetes. 972 86

The high incidence of vascular complications in patients with diabetes mellitus remains incompletely understood. Several metabolic or endocrine abnormalities have been postulated as possible triggers for micro and macroangiopathies. This review article focuses on the consequences of hyperglycemia, leading to the formation of advanced glycation endproducts (AGE), on vascular function. Advanced glycation endproducts are the product of the binding of aldoses onto free amino groups of proteins or lipoproteins, which, after molecular rearrangement, result in a class of molecules of a brown color and specific fluorescence. Different cell membrane proteins have been shown to bind AGE and the best characterized receptor for AGE has been named RAGE. The AGE receptor is present on different cell types including endothelial cells, smooth muscle cells, lymphocytes and monocytes. Experimental studies have revealed that the binding of AGE to RAGE produces an activation of monocytes and endothelial cells. Activated endothelial cells produce interleukin and express vascular cell adhesion molecule and tissue factor. Advanced glycation endproducts, when infused into animals, induce an increase in vascular permeability. The blockade of RAGE by specific antibodies corrects the hypermeability observed in diabetic animals. The prevention of AGE formation by aminoguanidine treatment improves the microvascular lesions found in diabetic animals either in the retina or the glomerus. The infusion of recombinant RAGE in diabetic animals corrects hyperpermeability. The colocalization of RAGE and AGE at the microvascular site of the injury suggests that their interaction may play a significant role in the pathogenesis of diabetic vascular lesions.
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PMID:Diabetes, advanced glycation endproducts and vascular disease. 979 76


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