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Sample records for glycation end-products detected

  1. Fluorescent advanced glycation end products in the detection of factual stages of cartilage degeneration

    Czech Academy of Sciences Publication Activity Database

    Handl, M.; Filová, Eva; Kubala, M.; Lánský, Z.; Koláčná, Lucie; Vorlíček, Jaroslav; Trč, T.; Amler, Evžen

    2007-01-01

    Roč. 56, č. 2 (2007), s. 235-242 ISSN 0862-8408 R&D Projects: GA AV ČR(CZ) 1ET400110403; GA AV ČR(CZ) IAA500390702 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50110509 Keywords : Nonenzymic glycation * Cartilage * Knee joint Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.505, year: 2007

  2. Inhibition of protein glycation and advanced glycation end products ...

    African Journals Online (AJOL)

    Advanced glycation end products (AGEs) formation is increased in diabetes mellitus, leading to microvascular and macrovascular complications. Recently, much attention has been focused on natural and synthetic inhibitors to delay the onset or progression of diabetes and its comorbidities. Ascorbic acid (AA) can react with ...

  3. Dietary advanced glycation end products and aging.

    Science.gov (United States)

    Luevano-Contreras, Claudia; Chapman-Novakofski, Karen

    2010-12-01

    Advanced glycation end products (AGEs) are a heterogeneous, complex group of compounds that are formed when reducing sugar reacts in a non-enzymatic way with amino acids in proteins and other macromolecules. This occurs both exogenously (in food) and endogenously (in humans) with greater concentrations found in older adults. While higher AGEs occur in both healthy older adults and those with chronic diseases, research is progressing to both quantify AGEs in food and in people, and to identify mechanisms that would explain why some human tissues are damaged, and others are not. In the last twenty years, there has been increased evidence that AGEs could be implicated in the development of chronic degenerative diseases of aging, such as cardiovascular disease, Alzheimer's disease and with complications of diabetes mellitus. Results of several studies in animal models and humans show that the restriction of dietary AGEs has positive effects on wound healing, insulin resistance and cardiovascular diseases. Recently, the effect of restriction in AGEs intake has been reported to increase the lifespan in animal models. This paper will summarize the work that has been published for both food AGEs and in vivo AGEs and their relation with aging, as well as provide suggestions for future research.

  4. Dietary Advanced Glycation End Products and Aging

    Directory of Open Access Journals (Sweden)

    Karen Chapman-Novakofski

    2010-12-01

    Full Text Available Advanced glycation end products (AGEs are a heterogeneous, complex group of compounds that are formed when reducing sugar reacts in a non-enzymatic way with amino acids in proteins and other macromolecules. This occurs both exogenously (in food and endogenously (in humans with greater concentrations found in older adults. While higher AGEs occur in both healthy older adults and those with chronic diseases, research is progressing to both quantify AGEs in food and in people, and to identify mechanisms that would explain why some human tissues are damaged, and others are not. In the last twenty years, there has been increased evidence that AGEs could be implicated in the development of chronic degenerative diseases of aging, such as cardiovascular disease, Alzheimer’s disease and with complications of diabetes mellitus. Results of several studies in animal models and humans show that the restriction of dietary AGEs has positive effects on wound healing, insulin resistance and cardiovascular diseases. Recently, the effect of restriction in AGEs intake has been reported to increase the lifespan in animal models. This paper will summarize the work that has been published for both food AGEs and in vivo AGEs and their relation with aging, as well as provide suggestions for future research.

  5. Advanced glycation end product ligands for the receptor for advanced glycation end products: Biochemical characterization and formation kinetics

    NARCIS (Netherlands)

    Valencia, J.V.; Weldon, S.C.; Quinn, D.; Kiers, G.H.; Groot, J. de; TeKoppele, J.M.; Hughes, T.E.

    2004-01-01

    Advanced glycation end products (AGEs) accumulate with age and at an accelerated rate in diabetes. AGEs bind cell-surface receptors including the receptor for advanced glycation end products (RAGE). The dependence of RAGE binding on specific biochemical characteristics of AGEs is currently unknown.

  6. A novel monoclonal antibody targeting carboxymethyllysine, an advanced glycation end product in atherosclerosis and pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Ulrika Wendel

    Full Text Available Advanced glycation end products are formed by non-enzymatic reactions between proteins and carbohydrates, causing irreversible lysine and arginine alterations that severely affect protein structure and function. The resulting modifications induce inflammation by binding to scavenger receptors. An increase in advanced glycation end products is observed in a number of diseases e.g. atherosclerosis and cancer. Since advanced glycation end products also are present in healthy individuals, their detection and quantification are of great importance for usage as potential biomarkers. Current methods for advanced glycation end product detection are though limited and solely measure total glycation. This study describes a new epitope-mapped single chain variable fragment, D1-B2, against carboxymethyllysine, produced from a phage library that was constructed from mouse immunizations. The phage library was selected against advanced glycation end product targets using a phage display platform. Characterization of its binding pattern was performed using large synthetic glycated peptide and protein libraries displayed on microarray slides. D1-B2 showed a preference for an aspartic acid, three positions N-terminally from a carboxymethyllysine residue and also bound to a broad collection of glycated proteins. Positive immunohistochemical staining of mouse atherosclerotic plaques and of a tissue microarray of human pancreatic tumors confirmed the usability of the new scFv for advanced glycation end product detection in tissues. This study demonstrates a promising methodology for high-throughput generation of epitope-mapped monoclonal antibodies against AGE.

  7. Effects of advanced glycation end-products (AGEs) on skin ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-06-21

    Jun 21, 2012 ... Abbreviations: AGEs, Glycation end-products; SD, Sprague-. Dawley; STZ, streptozotocin; EGF, epidermal growth factor; NF-. kB, nuclear factor-kappa B. result in significant morbidity. Impaired wound healing is a common vascular complication of diabetes mellitus and constitutes a major clinical problem ...

  8. Effect of dietary advanced glycation end products on mouse liver.

    Directory of Open Access Journals (Sweden)

    Raza Patel

    Full Text Available UNLABELLED: The exact pathophysiology of non-alcoholic steatohepatitis (NASH is not known. Previous studies suggest that dietary advanced glycation end products (AGEs can cause oxidative stress in liver. We aim to study the effects of dietary AGEs on liver health and their possible role in the pathogenesis of NASH. METHODS: Two groups of mice were fed the same diet except the AGE content varied. One group was fed a high AGE diet and the second group was fed a regular AGE diet. Liver histology, alanine aminotransferase, aspartate aminotransferase, fasting glucose, fasting insulin, insulin resistance and glucose tolerance were assessed. RESULTS: Histology revealed that neutrophil infiltration occurred in the livers of the high AGE group at week 26; steatosis did not accompany liver inflammation. At week 39 livers from both groups exhibited macro- or micro-steatosis, yet no inflammation was detected. Higher insulin levels were detected in the regular AGE group at week 26 (P = 0.034, compared to the high AGE group. At week 39, the regular AGE group showed higher levels of alanine aminotransferase (P<0.01 and aspartate aminotransferase (P = 0.02 than those of the high AGE group. CONCLUSIONS: We demonstrate that a high AGE diet can cause liver inflammation in the absence of steatosis. Our results show that dietary AGEs could play a role in initiating liver inflammation contributing to the disease progression of NASH. Our observation that the inflammation caused by high AGE alone did not persist suggests interesting future directions to investigate how AGEs contribute to pro-oxidative and anti-oxidative pathways in the liver.

  9. Role of advanced glycation end products in cellular signaling

    Directory of Open Access Journals (Sweden)

    Christiane Ott

    2014-01-01

    Full Text Available Improvements in health care and lifestyle have led to an elevated lifespan and increased focus on age-associated diseases, such as neurodegeneration, cardiovascular disease, frailty and arteriosclerosis. In all these chronic diseases protein, lipid or nucleic acid modifications are involved, including cross-linked and non-degradable aggregates, such as advanced glycation end products (AGEs. Formation of endogenous or uptake of dietary AGEs can lead to further protein modifications and activation of several inflammatory signaling pathways. This review will give an overview of the most prominent AGE-mediated signaling cascades, AGE receptor interactions, prevention of AGE formation and the impact of AGEs during pathophysiological processes.

  10. Accumulation of advanced glycation end products in canine atherosclerosis.

    Science.gov (United States)

    Chiers, K; Vandenberge, V; Ducatelle, R

    2010-07-01

    Atherosclerosis is an uncommon lesion in animals and particularly in dogs. Prominent atherosclerotic lesions of the coronary arteries are described in three dogs. These comprised an expansion of the tunica media by the accumulation of foam cells and/or cholesterol crystals, with subsequent narrowing of the vascular lumen. Immunohistochemical analysis revealed the accumulation of advanced glycation end products (AGEs) in foam cells, macrophages and lymphocytes. As in man, these findings suggest a possible role of AGEs in the development of canine atherosclerosis. (c) 2009 Elsevier Ltd. All rights reserved.

  11. Sulforaphane inhibits advanced glycation end product-induced pericyte damage by reducing expression of receptor for advanced glycation end products.

    Science.gov (United States)

    Maeda, Sayaka; Matsui, Takanori; Ojima, Ayako; Takeuchi, Masayoshi; Yamagishi, Sho-Ichi

    2014-09-01

    Advanced glycation end products (AGEs) not only inhibit DNA synthesis but also play a role in diabetic retinopathy by evoking apoptosis and inflammation in retinal pericytes via interaction with a receptor for AGE (RAGE). Similarly, sulforaphane, which is a naturally occurring isothiocyanate that is found in widely consumed cruciferous vegetables, protects against oxidative stress-induced tissue damage. Therefore, we hypothesized that sulforaphane could inhibit AGE-induced pericytes injury through its antioxidative properties. Advanced glycation end product stimulated superoxide generation as well as RAGE gene and protein expression in bovine-cultured retinal pericytes, and these effects were prevented by the treatment with sulforaphane. Antibodies directed against RAGE also blocked AGE-evoked reactive oxygen species generation in pericytes. Sulforaphane and antibodies directed against RAGE significantly inhibited the AGE-induced decrease in DNA synthesis, apoptotic cell death, and up-regulation of monocyte chemoattractant protein 1 messenger RNA levels in pericytes. For the first time, the present study demonstrates that sulforaphane could inhibit DNA synthesis, apoptotic cell death, and inflammatory reactions in AGE-exposed pericytes, partly by suppressing RAGE expression via its antioxidative properties. Blockade of the AGE-RAGE axis in pericytes by sulforaphane might be a novel therapeutic target for the treatment of diabetic retinopathy. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Advanced glycation end product ligands for the receptor for advanced glycation end products: biochemical characterization and formation kinetics.

    Science.gov (United States)

    Valencia, Jessica V; Weldon, Stephen C; Quinn, Douglas; Kiers, Geesje H; DeGroot, Jeroen; TeKoppele, Johan M; Hughes, Thomas E

    2004-01-01

    Advanced glycation end products (AGEs) accumulate with age and at an accelerated rate in diabetes. AGEs bind cell-surface receptors including the receptor for advanced glycation end products (RAGE). The dependence of RAGE binding on specific biochemical characteristics of AGEs is currently unknown. Using standardized procedures and a variety of AGE measures, the present study aimed to characterize the AGEs that bind to RAGE and their formation kinetics in vitro. To produce AGEs with varying RAGE binding affinity, bovine serum albumin (BSA) AGEs were prepared with 0.5M glucose, fructose, or ribose at times of incubation from 0 to 12 weeks or for up to 3 days with glycolaldehyde or glyoxylic acid. The AGE-BSAs were characterized for RAGE binding affinity, fluorescence, absorbance, carbonyl content, reactive free amine content, molecular weight, pentosidine content, and N-epsilon-carboxymethyl lysine content. Ribose-AGEs bound RAGE with high affinity within 1 week of incubation in contrast to glucose- and fructose-AGE, which required 12 and 6 weeks, respectively, to generate equivalent RAGE ligands (IC50=0.66, 0.93, and 1.7 microM, respectively). Over time, all of the measured AGE characteristics increased. However, only free amine content robustly correlated with RAGE binding affinity. In addition, detailed protocols for the generation of AGEs that reproducibly bind RAGE with high affinity were developed, which will allow for further study of the RAGE-AGE interaction.

  13. Relationship between Advanced Glycation End Products and Steroidogenesis in PCOS.

    Science.gov (United States)

    Garg, Deepika; Merhi, Zaher

    2016-10-21

    Women with PCOS have elevated levels of the harmful Advanced Glycation End Products (AGEs), which are highly reactive molecules formed after glycation of lipids and proteins. Additionally, AGEs accumulate in the ovaries of women with PCOS potentially contributing to the well-documented abnormal steroidogenesis and folliculogenesis. A systematic review of articles and abstracts available in PubMed was conducted and presented in a systemic manner. This article reports changes in steroidogenic enzyme activity in granulosa and theca cells in PCOS and PCOS-models. It also described the changes in AGEs and their receptors in the ovaries of women with PCOS and presents the underlying mechanism(s) whereby AGEs could be responsible for the PCOS-related changes in granulosa and theca cell function thus adversely impacting steroidogenesis and follicular development. AGEs are associated with hyperandrogenism in PCOS possibly by altering the activity of various enzymes such as cholesterol side-chain cleavage enzyme cytochrome P450, steroidogenic acute regulatory protein, 17α-hydroxylase, and 3β-hydroxysteroid dehydrogenase. AGEs also affect luteinizing hormone receptor and anti-Mullerian hormone receptor expression as well as their signaling pathways in granulosa cells. A better understanding of how AGEs alter granulosa and theca cell function is likely to contribute meaningfully to a conceptual framework whereby new interventions to prevent and/or treat ovarian dysfunction in PCOS can ultimately be developed.

  14. Advanced glycation end products in the skin are enhanced in COPD

    NARCIS (Netherlands)

    Hoonhorst, Susan J. M.; Loi, Adele T. Lo Tam; Hartman, Jorine E.; Telenga, Eef D.; van den Berge, Maarten; Koenderman, Leo; Lammers, Jan Willem J.; Boezen, H. Marike; Postma, Dirkje S.; ten Hacken, Nick H. T.

    Background. Cigarette smoking is the main cause of chronic obstructive pulmonary disease (COPD) inducing oxidative stress and local tissue injury, resulting in pulmonary inflammation. Advanced glycation end products (AGEs) are produced by glycation and oxidation processes and their formation is

  15. Aging ovary and the role for advanced glycation end products.

    Science.gov (United States)

    Pertynska-Marczewska, Magdalena; Diamanti-Kandarakis, Evanthia

    2017-03-01

    The hypothalamic gonadotropin-releasing hormone pulse generator, the pituitary gonadotropes, the ovaries, and the uterus play a crucial role in female fertility. A decline in reproductive performance represents a complex interplay of actions at all levels of the hypothalamic-pituitary-ovarian axis. Recently, in the field of female reproductive aging attention is drawn to the carbonyl stress theory. Advanced glycation end products (AGEs) contribute directly to protein damage, induce a chain of oxidative stress (OS) reactions, and increase inflammatory reactions. Here, we highlight some of the mechanisms underlying glycation damage in the ovary. Searches of electronic databases were performed. Articles relevant to possible role of OS, AGEs, and receptor for AGE (RAGE) in aging ovary were summarized in this interpretive literature review. Follicular microenvironment undergoes an increase in OS with aging. Data support the role of OS in ovulatory dysfunction because AGEs are well-recognized mediators of increased OS. RAGE and AGE-modified proteins with activated nuclear factor-kappa B are expressed in human ovarian tissue. It was suggested that accumulation of AGEs products at the level of the ovarian follicle might trigger early ovarian aging or could be responsible for reduced glucose uptake by granulosa cells, potentially altering follicular growth. Moreover, impaired methylglyoxal detoxification causing relevant damage to the ovarian proteome might be one of the mechanisms underlying reproductive aging. Further investigation of the role for the AGE-RAGE axis in the ovarian follicular environment is needed, and results could relate to assisted reproduction technology outcomes and new measures of ovarian reserve.

  16. Characterization of anti-advanced glycation end product antibodies to nonenzymatically lysine-derived and arginine-derived glycated products.

    Science.gov (United States)

    Choi, Yeong-Gon; Lim, Sabina

    2009-01-01

    N(epsilon)-(carboxymethyl)lysine (CML) and N(epsilon)-(carboxyethyl)lysine (CEL) termed advanced glycation end products (AGEs) are known to be produced by nonenzymatic glycation between bovine serum albumin (BSA) and D-glucose. This study is to characterize the immunoreactivity of anti-AGE antibodies including anti-CML and anti-CEL antibodies. Using AGE-modified BSA (AGE-BSA) as an immunogen, a polyclonal anti-AGE immunoglobulin G (IgG) was produced. The anti-AGE IgG could strongly detect AGEs formed on BSA, at least in part, AGEs produced on both residues Lys and Arg due to its immunoreaction with Lys-derived and Arg-derived AGEs produced by NaCNBH(3), a reducing agent, in amino acid glycation analysis, but the pre-immune serum could not. As the anti-CML antibody could also strongly react with AGE-BSA, this suggests that CML is a major nonenzymatically glycated product cross-linked to BSA. Furthermore, CEL is associated with distinguishable polymerization of BSA from CML polymerization of BSA, though weaker than CML and was not produced by Lys glycation analysis. These results indicate that the anti-AGE antibody is effective for detecting both Lys-derived and Arg-derived AGEs, and CML and CEL distinctively polymerize albumin as major AGEs present on AGE-BSA.

  17. PSEUDOAFFINITY CHROMATOGRAPHY ENRICHMENT OF GLYCATED PEPTIDES FOR MONITORING ADVANCED GLYCATION END PRODUCTS (AGES IN METABOLIC DISORDERS

    Directory of Open Access Journals (Sweden)

    Rajasekar R. Prasanna

    2016-09-01

    Full Text Available Advanced Glycation End (AGE products are produced due to diabetic progression and they are responsible for many complications in the diabetic disorder. The diabetic progression is measured, particularly following glycated hemoglobin using specific antibodies. However, the most abundant protein in blood, human serum albumin, is also found to be glycated which has a much shorter half life and gives information on short term glycemic control. In addition, glycated albumins are considered as markers of diabetic complications such as nephropathy, peripheral vascular calcification and also in Alzheimer’s disease. The glycation proceeds from the interaction between aldehyde group of sugar and the free amino group of the protein, resulting in the formation of Schiff’s base, which undergoes a series of modifications leading to generation of imidazoyl derivatives of amino acids known as Amadori rearrangement products. The imidazoyl derivatives from arginine and lysine are the most prominent modifications observed in proteins in the presence of reducing sugar and these imidazoyl derivatives have an affinity towards certain transition metal ions. Based on our earlier exhaustive work on trapping the histidine peptides using transition metal ion, Cu(II linked to imino-diacetate complex, we explored Cu(II immobilized metal affinity chromatography (IMAC as a potential tool for specific detection of glycated peptides of human serum albumin. Our results clearly demonstrate that Cu(II IMAC is able to detect glycated peptides very efficiently while the non-glycated forms were not retained on the Cu (II column as confirmed by LC-MS/MS analysis. We further discuss the utility of IMAC technology to enrich the detection of AGE products in plasma. We anticipate that these studies may provide valuable information on understanding disease pathologies and the potential of AGE products as biomarkers of various diseases including neurodegenerative, renal and

  18. Voltammetric Detection of S100B Protein Using His-Tagged Receptor Domains for Advanced Glycation End Products (RAGE Immobilized onto a Gold Electrode Surface

    Directory of Open Access Journals (Sweden)

    Edyta Mikuła

    2014-06-01

    Full Text Available In this work we report on an electrochemical biosensor for the determination of the S100B protein. The His-tagged VC1 domains of Receptors for Advanced Glycation End (RAGE products used as analytically active molecules were covalently immobilized on a monolayer of a thiol derivative of pentetic acid (DPTA complex with Cu(II deposited on a gold electrode surface. The recognition processes between the RAGE VC1 domain and the S100B protein results in changes in the redox activity of the DPTA-Cu(II centres which were measured by Osteryoung square-wave voltammetry (OSWV. In order to verify whether the observed analytical signal originates from the recognition process between the His6–RAGE VC1 domains and the S100B protein, the electrode modified with the His6–RAGE C2 and His6–RAGE VC1 deleted domains which have no ability to bind S100B peptides were applied. The proposed biosensor was quite sensitive, with a detection limit of 0.52 pM recorded in the buffer solution. The presence of diluted human plasma and 10 nM Aβ1-40 have no influence on the biosensor performance.

  19. Advanced glycation end products and their relevance in female reproduction.

    Science.gov (United States)

    Merhi, Z

    2014-01-01

    Do advanced glycation end products (AGEs) and their receptors play a role in female reproduction? AGEs might contribute to the etiology of polycystic ovary syndrome (PCOS) and infertility. The endogenous AGEs are produced in the body by chemical reactions. Exogenous sources of AGEs are diet and smoking. AGEs have been proposed to be among the main intermediaries involved in several diseases, such as metabolic syndrome, type 2 diabetes mellitus, cardiovascular disease, ovarian aging, inflammation, neurodegenerative disorders and PCOS. A systematic review was performed for all available basic science and clinical peer-reviewed articles published in PubMed from 1987 to date. Abstracts of annual meetings of the Endocrine Society and American Society for Reproductive Medicine were also reviewed. A total of 275 publications and scientific abstracts were identified from the initial search. Sixty-two papers and four published scientific abstracts were selected for full review. The main outcomes were the regulatory effects of AGEs on: (i) granulosa cells, adipocyte physiology, obesity and insulin resistance in women with PCOS and in polycystic ovary animal models and (ii) infertility and measures of ovarian reserve. There is an intricate relationship between the AGE-RAGE (receptor for AGEs) system and some aspects of PCOS, such as granulosa cell dysfunction, adipocyte pathophysiology, obesity and insulin resistance. Additionally, irregular ovarian AGE signaling might in part explain the abnormal ovarian histology observed in women with PCOS. The ovarian dysfunction due to AGEs in women without PCOS suggests a role for the AGE-RAGE system in the ovarian follicular environment, and might relate to assisted reproduction technology outcome and measures of ovarian reserve. The body of literature currently available limits these findings. The results obtained from granulosa cell lines and animal models may not fully extrapolate to humans. This review underscores a critical need

  20. The receptor for advanced glycation end products in ventilator-induced lung injury

    NARCIS (Netherlands)

    Kuipers, Maria T.; Aslami, Hamid; Tuinman, Pieter Roel; Tuip-de Boer, Anita M.; Jongsma, Geartsje; van der Sluijs, Koenraad F.; Choi, Goda; Wolthuis, Esther K.; Roelofs, Joris J. T. H.; Bresser, Paul; Schultz, Marcus J.; van der Poll, Tom; Wieland, Catharina W.

    2014-01-01

    Mechanical ventilation (MV) can cause ventilator-induced lung injury (VILI). The innate immune response mediates this iatrogenic inflammatory condition. The receptor for advanced glycation end products (RAGE) is a multiligand receptor that can amplify immune and inflammatory responses. We

  1. Receptor for advanced glycation end products is protective during murine tuberculosis

    NARCIS (Netherlands)

    van Zoelen, Marieke A. D.; Wieland, Catharina W.; van der Windt, Gerritje J. W.; Florquin, Sandrine; Nawroth, Peter P.; Bierhaus, Angelika; van der Poll, Tom

    2012-01-01

    The development of active tuberculosis after infection with Mycobacterium tuberculosis is almost invariably associated with a persistent or transient state of relative immunodeficiency. The receptor for advanced glycation end products (RAGE) is a promiscuous receptor that is involved in pulmonary

  2. Receptor for advanced glycation end products is protective during murine tuberculosis.

    NARCIS (Netherlands)

    Zoelen, M.A. van; Wieland, C.W.; Windt, G.J. van der; Florquin, S.; Nawroth, P.P.; Bierhaus, A.; Poll, T. van der

    2012-01-01

    The development of active tuberculosis after infection with Mycobacterium tuberculosis is almost invariably associated with a persistent or transient state of relative immunodeficiency. The receptor for advanced glycation end products (RAGE) is a promiscuous receptor that is involved in pulmonary

  3. The receptor for advanced glycation end products in ventilator-induced lung injury

    NARCIS (Netherlands)

    Kuipers, Maria T; Aslami, Hamid; Tuinman, Pieter Roel; Tuip-de Boer, Anita M; Jongsma, Geartsje; van der Sluijs, Koenraad F; Choi, Goda; Wolthuis, Esther K; Roelofs, Joris Jth; Bresser, Paul; Schultz, Marcus J; van der Poll, Tom; Wieland, Catharina W

    2014-01-01

    BACKGROUND: Mechanical ventilation (MV) can cause ventilator-induced lung injury (VILI). The innate immune response mediates this iatrogenic inflammatory condition. The receptor for advanced glycation end products (RAGE) is a multiligand receptor that can amplify immune and inflammatory responses.

  4. Soluble receptor for advanced glycation end products (sRAGE) and ...

    African Journals Online (AJOL)

    Eman M. Sherif

    2014-07-10

    Jul 10, 2014 ... Abstract Background: Advanced glycation end products (AGEs) are a heterogeneous and com- plex group of biochemical compounds, resulting from nonenzymatic glycation and oxidation of protein, nucleic acids, and lipids. Aim of the study: To assess sRAGE and CIMT in patients with T1DM and their ...

  5. Survey of the Distribution of a Newly Characterized Receptor for Advanced Glycation End Products in Tissues

    OpenAIRE

    Brett, Jerold; Schmidt, Ann Marie; Yan, Shi Du; Zou, Yu Shan; Weidman, Elliott; Pinsky, David; Nowygrod, Roman; Neeper, Michael; Przysiecki, Craig; Shaw, Alan; Migheli, Antonio; Stern, David

    1993-01-01

    Advanced glycation end products (AGEs), the final products of nonenzymatic glycation and oxidation of proteins, are found in the plasma and accumulate in the tissues during aging and at an accelerated rate in diabetes. A novel integral membrane protein, termed receptor for AGE (RAGE), forms a central part of the cell surface binding site for AGEs. Using monospecific, polyclonal antibody raised to human recombinant and bovine RAGE, immunostaining of bovine tissues showed RAGE in the vasculatur...

  6. [Expression and function of receptors for advanced glycation end products in bovine corneal endothelial cells].

    Science.gov (United States)

    Kaji, Yuichi

    2005-11-01

    Corneal endothelial cell loss is a change that occurs with age, but its mechanism is still unclear. We postulated that interaction between advanced glycation end product(AGE) and its receptors is implicated in the corneal endothelial cell loss with age. We investigated the expression of AGE receptors: receptors for AGE(RAGE) and galectin-3 in bovine corneal endothelial cells by reverse transcription-polymerase chain reaction(RT-PCR) and immunohistochemistry. In addition, we investigated the effect of AGE on the cultured corneal endothelial cells. Expression of RAGE and galectin-3 was detected in bovine corneal endothelial cells. Galectin-3 was important in the internalization of AGE. In contrast, RAGE was important in the generation of reactive oxygen species and induction of apoptosis. Based on these data, the interaction of AGE in aqueous humor and AGE receptors expressed on the corneal endothelial cells was speculated to have a role in the corneal endothelial cell loss with age.

  7. The Contribution of Advanced Glycation End product (AGE) accumulation to the decline in motor function

    NARCIS (Netherlands)

    Drenth, Hans; Zuidema, Sytse; Bunt, Steven; Bautmans, Ivan; van der Schans, Cees; Hobbelen, Hans

    2016-01-01

    Diminishing motor function is commonly observed in the elderly population and is associated with a wide range of adverse health consequences. Advanced Glycation End products (AGE's) may contribute to age-related decline in the function of cells and tissues in normal ageing. Although the negative

  8. Receptor for advanced glycation end product expression in experimental diabetic retinopathy

    NARCIS (Netherlands)

    Wang, Yumei; Hagen, Filanziska Vom; Pfister, Frederick; Bierhaus, Angelika; Feng, Yuxi; Gans, Reinhold; Hammes, Hans-Peter; Schleicher, E; Somoza,; Shieberle, P

    2008-01-01

    The advanced glycation end product (AGE)-receptor for AGE (RAGE) pathway is involved in the pathogenesis of diabetic microvascular damage. The special distribution of RAGE and its engagement has an impact on the development of diabetic retinopathy. In the present study, we used immunofluorescence

  9. Effect of collagen turnover on the accumulation of advanced glycation end products

    NARCIS (Netherlands)

    Verzijl, N.; Degroot, J.; Thorpe, S. R.; Bank, R. A.; Shaw, J. N.; Lyons, T. J.; Bijlsma, J. W.; Lafeber, F. P.; Baynes, J. W.; TeKoppele, J. M.

    2000-01-01

    Collagen molecules in articular cartilage have an exceptionally long lifetime, which makes them susceptible to the accumulation of advanced glycation end products (AGEs). In fact, in comparison to other collagen-rich tissues, articular cartilage contains relatively high amounts of the AGE

  10. Clinical and prognostic value of advanced glycation end-products in chronic heart failure

    NARCIS (Netherlands)

    Hartog, Jasper W. L.; Voors, Adriaan A.; Schalkwijk, Casper G.; Scheijen, Jean; Smilde, Tom D. J.; Damman, Kevin; Bakker, Stephan J. L.; Smit, Andries J.; van Veldhuisen, Dirk J.

    2007-01-01

    Aims Advanced glycation end-products (AGEs) have been proposed as a novel factor involved in the development and progression of chronic heart failure (CHF). We aimed to determine whether plasma levels of N-epsilon-(carboxymethyl)lysine (CML) and N-epsilon-(carboxyethyl)lysine (CEL), two well-known

  11. Advanced glycation end-products, a pathophysiological pathway in the cardiorenal syndrome

    NARCIS (Netherlands)

    Willemsen, Suzan; Hartog, Jasper W. L.; Heiner-Fokkema, Rebecca; van Veldhuisen, Dirk J.; Voors, Adriaan A.

    The prevalence of heart failure (HF) is increasing. A distinction is made between diastolic HF (preserved left ventricular ejection fraction (LVEF)) and systolic HF (reduced LVEF). Advanced glycation end-products (AGEs) are crystallized proteins that accumulate during ageing, but are particularly

  12. Advanced glycation end-products (AGES) and heart failure : Pathophysiology and clinical implications

    NARCIS (Netherlands)

    Hartog, Jasper W. L.; Voors, Adriaan A.; Bakker, Stephan J. L.; Smit, Andries J.; van Veldhuisen, Dirk J.

    2007-01-01

    Advanced glycation end-products (AGEs) are molecules formed during a non-enzymatic reaction between proteins and sugar residues, called the Maillard reaction. AGEs accumulate in the human body with age, and accumulation is accelerated in the presence of diabetes mellitus. In patients with diabetes,

  13. Receptor for Advanced Glycation End Products (RAGE) Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia

    NARCIS (Netherlands)

    Achouiti, Ahmed; de Vos, Alex F.; van 't Veer, Cornelis; Florquin, Sandrine; Tanck, Michael W.; Nawroth, Peter P.; Bierhaus, Angelika; van der Poll, Tom; van Zoelen, Marieke A. D.

    2016-01-01

    Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE) is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed

  14. Skin accumulation of advanced glycation end products is increased in patients with an abdominal aortic aneurysm

    NARCIS (Netherlands)

    Boersema, Jeltje; de Vos, Lisanne C.; Links, Thera P.; Mulder, Douwe J.; Smit, Andries J.; Zeebregts, Clark J.; Lefrandt, Joop D.

    2017-01-01

    Objective: Advanced glycation end products (AGEs) are implicated in the pathogenesis of cardiovascular disease. Accumulation of AGEs is driven by oxidative or glycemic stress and can be assessed by skin autofluorescence (SAF). SAF is increased in patients with peripheral artery disease (PAD) and

  15. Advanced glycation End-products (AGEs): an emerging concern for processed food industries.

    Science.gov (United States)

    Sharma, Chetan; Kaur, Amarjeet; Thind, S S; Singh, Baljit; Raina, Shiveta

    2015-12-01

    The global food industry is expected to increase more than US $ 7 trillion by 2014. This rise in processed food sector shows that more and more people are diverging towards modern processed foods. As modern diets are largely heat processed, they are more prone to contain high levels of advanced glycation end products (AGEs). AGEs are a group of complex and heterogeneous compounds which are known as brown and fluorescent cross-linking substances such as pentosidine, non-fluorescent cross-linking products such as methylglyoxal-lysine dimers (MOLD), or non-fluorescent, non-cross linking adducts such as carboxymethyllysine (CML) and pyrraline (a pyrrole aldehyde). The chemistry of the AGEs formation, absorption and bioavailability and their patho-biochemistry particularly in relation to different complications like diabetes and ageing discussed. The concept of AGEs receptor - RAGE is mentioned. AGEs contribute to a variety of microvascular and macrovascular complications through the formation of cross-links between molecules in the basement membrane of the extracellular matrix and by engaging the receptor for advanced glycation end products (RAGE). Different methods of detection and quantification along with types of agents used for the treatment of AGEs are reviewed. Generally, ELISA or LC-MS methods are used for analysis of foods and body fluids, however lack of universally established method highlighted. The inhibitory effect of bioactive components on AGEs by trapping variety of chemical moieties discussed. The emerging evidence about the adverse effects of AGEs makes it necessary to investigate the different therapies to inhibit AGEs.

  16. Effects of advanced glycation end-products (AGEs) on skin ...

    African Journals Online (AJOL)

    kappa B (NF-κB) localization and cell viability were measured in vivo. Keratinocytes from normal skin were cultured in AGE-enriched conditional media, and the cell viability, apoptosis, adhesion and migration were detected in order to find the ...

  17. Skin autofluorescence, a marker of advanced glycation end products and oxidative stress, is increased in recently preeclamptic women

    NARCIS (Netherlands)

    Blaauw, Judith; Smit, Andries J.; van Pampus, Maria G.; van Doormaal, Jasper J.; Aarnoudse, Jan G.; Rakhorst, Gerhard; Graaff, Reindert

    Objective: Advanced glycation end-products are considered to be markers of oxidative stress and to be involved in the atherosclerotic process. We investigated skin autofluorescence, which reflected advanced glycation end-product accumulation, in recently preeclamptic women and its relationship with

  18. Skin advanced glycation end products in HIV infection are increased and predictive of development of cardiovascular events

    NARCIS (Netherlands)

    Sprenger, Herman G.; Bierman, Wouter F.; Martes, Melanie I.; Graaff, Reindert; van der Werf, Tjip S.; Smit, Andries J.

    2017-01-01

    Objective: HIV-1 infection is associated with an increased cardiovascular disease (CVD) risk. Advanced glycation end products are formed as stable markers of glycaemic and oxidative stress. Skin autofluorescence (SAF) as marker of accumulated advanced glycation end products is increased and

  19. Reference values for the Chinese population of skin autofluorescence as a marker of advanced glycation end products accumulated in tissue

    NARCIS (Netherlands)

    Yue, X.; Hu, H.; Koetsier, M.; Graaff, R.; Han, C.

    Aim Advanced glycation end products play an important role in the pathophysiology of several chronic and age-related diseases, especially diabetes mellitus. Skin autofluorescence is a non-invasive method for assessing levels of tissue advanced glycation end products. This study aims to establish the

  20. [The effect of valsartan on the expression of the receptor for advanced glycation end products in human glomerular mesangial cells].

    Science.gov (United States)

    Zhong, Lin-na; Huang, Guo-liang; Feng, Min; Zhang, Ying

    2011-08-01

    To elucidate the effect of valsartan on human glomerular mesangial cells oxidative stress and the expression of the receptor for advanced glycation end products (RAGE) induced by the advanced glycation end-products (AGEs). Human glomerular mesangial cells were treated with advanced glycation end-product-bovine serum albumin (AGE-BSA) in the presence of valsartan. The reactive oxygen species (ROS) in cells were measured by Flow cytometry, and the mRNA of p47 phox, which was the primary subunits of NADPH oxidase, was detected by semi-quantitative reberse transcription polymerase chain reaction (RT-PCR). The mRNA of RAGE was detected by RT-PCR and the RAGE protein was assayed by immunocytochemistry. The product of ROS, and the expression of p47 phox and RAGE in mesangial cells, which were treated with AGE-BSA in the presence of valsartan, were down-regulated compared with the groups treated with AGE-BSA (P RAGE, ROS and p47(phox) in mesangial cells. Valsartan could inhibit RAGE expression through downregulation of oxidative stress.

  1. Advanced glycation end-products induce heparanase expression in endothelial cells by the receptor for advanced glycation end products and through activation of the FOXO4 transcription factor.

    Science.gov (United States)

    An, Xiao-Fei; Zhou, Lei; Jiang, Peng-Jun; Yan, Ming; Huang, Yu-Jun; Zhang, Su-Na; Niu, Yun-Fei; Ten, Shi-Chao; Yu, Jiang-Yi

    2011-08-01

    As an endo-β (1-4)-D: -glucuronidase, heparanase can specifically cleave carbohydrate chains of heparan sulfate (HS) and has been implicated in development of endothelial cells dsyfunction. The advanced glycation end products (AGEs) play a pivotal role in the pathology of diabetic complications. In the present study, we investigated the effect of AGE-bovine serum albumin (AGE-BSA) on heparanase expression in human microvascular endothelial cells (HMVECs) and the underlying molecular mechanisms. The results indicated that in vitro direct exposure of HMVECs to AGE-BSA (300, 1000, and 3000 μg/ml) could increase heparanase mRNA and protein expression in a dose and time-dependent manner. The effect of 1000 μg/ml AGE-BSA could be abolished by neutralization with antibody of the receptor for advanced glycation end products (RAGE). Moreover, pretreatment with inhibitors of nuclear factor-κB (NF-κB) or PI3-kinase did not affect heparanase expression induced by AGE-BSA. Nevertheless, small interference RNA (siRNA) for transcriptional factor FOXO4 could reduce the increase of heparanase expression in HMVECs induced by 1000 μg/ml AGE-BSA. These results suggest that AGEs could induce heparanase expression in HMVECs by RAGE and predominantly through activation of the FOXO4 transcription factor.

  2. Soluble Receptor for Advanced Glycation End Product: A Biomarker for Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Louise J. N. Jensen

    2015-01-01

    Full Text Available The receptor of advanced glycation end products (RAGE and its ligands are linked to the pathogenesis of coronary artery disease (CAD, and circulating soluble receptor of advanced glycation end products (sRAGE, reflecting the RAGE activity, is suggested as a potential biomarker. Elevated sRAGE levels are reported in relation to acute ischemia and this review focuses on the role of sRAGE as a biomarker for the acute coronary syndrome (ACS. The current studies demonstrated that sRAGE levels are elevated in relation to ACS, however during a very narrow time period, indicating that the time of sampling needs attention. Interestingly, activation of RAGE may influence the pathogenesis and reflection in sRAGE levels in acute and stable CAD differently.

  3. Statins stimulate the production of a soluble form of the receptor for advanced glycation end products

    OpenAIRE

    Quade-Lyssy, Patricia; Kanarek, Anna Maria; Baiersdörfer, Markus; Postina, Rolf; Kojro, Elzbieta

    2013-01-01

    The beneficial effects of statin therapy in the reduction of cardiovascular pathogenesis, atherosclerosis, and diabetic complications are well known. The receptor for advanced glycation end products (RAGE) plays an important role in the progression of these diseases. In contrast, soluble forms of RAGE act as decoys for RAGE ligands and may prevent the development of RAGE-mediated disorders. Soluble forms of RAGE are either produced by alternative splicing [endogenous secretory RAGE (esRAGE)] ...

  4. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

    OpenAIRE

    Li,D.X.; Deng,T.Z.; Lv,J.; Ke,J.

    2014-01-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts t...

  5. Advanced Glycation End Products: Link between Diet and Ovulatory Dysfunction in PCOS?

    OpenAIRE

    Garg, Deepika; Merhi, Zaher

    2015-01-01

    PCOS is the most common cause of anovulation in reproductive-aged women with 70% experiencing ovulatory problems. Advanced glycation end products are highly reactive molecules that are formed by non-enzymatic reactions of sugars with proteins, nucleic acids and lipids. AGEs are also present in a variety of diet where substantial increase in AGEs can result due to thermal processing and modifications of food. Elevation in bodily AGEs, produced endogenously or absorbed exogenously from high-AGE...

  6. Advanced glycation end products regulate interleukin-1? production in human placenta

    OpenAIRE

    SENO, Kotomi; SASE, Saoko; OZEKI, Ayae; TAKAHASHI, Hironori; OHKUCHI, Akihide; SUZUKI, Hirotada; MATSUBARA, Shigeki; IWATA, Hisataka; KUWAYAMA, Takehito; SHIRASUNA, Koumei

    2017-01-01

    Maternal obesity is a major risk factor for pregnancy complications, causing inflammatory cytokine release in the placenta, including interleukin-1? (IL-1?), IL-6, and IL-8. Pregnant women with obesity develop accelerated systemic and placental inflammation with elevated circulating advanced glycation end products (AGEs). IL-1? is a pivotal inflammatory cytokine associated with obesity and pregnancy complications, and its production is regulated by NLR family pyrin domain-containing 3 (NLRP3)...

  7. Bio-optic signatures for advanced glycation end products in the skin in streptozotocin (STZ) Induced Diabetes (Conference Presentation)

    Science.gov (United States)

    Saidian, Mayer; Ponticorvo, Adrien; Rowland, Rebecca A.; Balbado, Melisa L.; Lentsch, Griffin; Balu, Mihaela; Alexander, Micheal; Shiri, Li; Lakey, Jonathan R. T.; Durkin, Anthony J.; Kohen, Roni; Tromberg, Bruce J.

    2017-02-01

    Type 1diabetes (T1D) is an autoimmune disorder that occurs due to the rapid destruction of insulin-producing beta cells, leading to insulin deficiency and the inability to regulate blood glucose levels and leads to destructive secondary complications. Advanced glycation end (AGEs) products, the result of the cross-linking of reducing sugars and proteins within the tissues, are one of the key causes of major complications associated with diabetes such as renal failure, blindness, nerve damage and vascular changes. Non-invasive techniques to detect AGEs are important for preventing the harmful effects of AGEs during diabetes mellitus. In this study, we utilized multiphoton microscopy to image biopsies taken from control rats and compared them to biopsies taken from streptozotocin (STZ) induced adult male diabetic rats. This was done at two and four weeks after the induction of hyperglycemia (>400 mg/dL) specifically to evaluate the effects of glycation on collagen. We chose to use an in-situ multiphoton microscopy method that combines multiphoton auto-florescence (AF) and second harmonic generation (SHG) to detect the microscopic influence of glycation. Initial results show high auto-florescence levels were present on the collagen, as a result of the accumulation of AGEs only two weeks after the STZ injection and considerably higher levels were present four weeks after the STZ injection. Future projects could involve evaluating advanced glycation end products in a clinical trial of diabetic patients.

  8. The association between various smoking behaviors, cotinine biomarkers and skin autofluorescence, a marker for advanced glycation end product accumulation

    NARCIS (Netherlands)

    van Waateringe, Robert P.; Mook-Kanamori, Marjonneke J.; Slagter, Sandra N.; van der Klauw, Melanie M.; van Vliet-Ostaptchouk, Jana V.; Graaff, Reindert; Lutgers, Helen L.; Suhre, Karsten; Selim, Mohammed M. El-Din; Mook-Kanamori, Dennis O.; Wolffenbuttel, Bruce H. R.

    2017-01-01

    BACKGROUND: Skin autofluorescence, a biomarker for advanced glycation end products (AGEs) accumulation, has been shown to predict diabetes-related cardiovascular complications and is associated with several environmental and lifestyle factors. In the present study, we examined the association

  9. The role of advanced glycation end products in various types of neurodegenerative disease: a therapeutic approach.

    Science.gov (United States)

    Salahuddin, Parveen; Rabbani, Gulam; Khan, Rizwan Hasan

    2014-09-01

    Protein glycation is initiated by a nucleophilic addition reaction between the free amino group from a protein, lipid or nucleic acid and the carbonyl group of a reducing sugar. This reaction forms a reversible Schiff base, which rearranges over a period of days to produce ketoamine or Amadori products. The Amadori products undergo dehydration and rearrangements and develop a cross-link between adjacent proteins, giving rise to protein aggregation or advanced glycation end products (AGEs). A number of studies have shown that glycation induces the formation of the β-sheet structure in β-amyloid protein, α-synuclein, transthyretin (TTR), copper-zinc superoxide dismutase 1 (Cu, Zn-SOD-1), and prion protein. Aggregation of the β-sheet structure in each case creates fibrillar structures, respectively causing Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, familial amyloid polyneuropathy, and prion disease. It has been suggested that oligomeric species of glycated α-synuclein and prion are more toxic than fibrils. This review focuses on the pathway of AGE formation, the synthesis of different types of AGE, and the molecular mechanisms by which glycation causes various types of neurodegenerative disease. It discusses several new therapeutic approaches that have been applied to treat these devastating disorders, including the use of various synthetic and naturally occurring inhibitors. Modulation of the AGE-RAGE axis is now considered promising in the prevention of neurodegenerative diseases. Additionally, the review covers several defense enzymes and proteins in the human body that are important anti-glycating systems acting to prevent the development of neurodegenerative diseases.

  10. Effect of dietary advanced glycation end products on postprandial appetite, inflammation, and endothelial activation in healthy overweight individuals

    DEFF Research Database (Denmark)

    Poulsen, Malene Wibe; Bak, Monika Judyta; Andersen, Jeanette Marker

    2014-01-01

    Advanced glycation end products (AGEs) formed in food during high-heat cooking may induce overeating and inflammation. We investigated whether AGE contents in a single meal affect postprandial appetite and markers of inflammation, endothelial activation, and oxidative stress.......Advanced glycation end products (AGEs) formed in food during high-heat cooking may induce overeating and inflammation. We investigated whether AGE contents in a single meal affect postprandial appetite and markers of inflammation, endothelial activation, and oxidative stress....

  11. Advanced glycation end products overload might explain intracellular cobalamin deficiency in renal dysfunction, diabetes and aging.

    Science.gov (United States)

    Obeid, Rima; Shannan, Batool; Herrmann, Wolfgang

    2011-11-01

    Advanced glycation end products (AGEs) contribute to aging. Cobalamin (Cbl) is required for cell growth and functions, and its deficiency causes serious complications. Diabetics and renal patients show high concentrations of Cbl, but metabolic evidence of Cbl deficiency that is reversible after Cbl treatment. Cbl might be sequestered in blood and cannot be delivered to the cell. Megalin mediates the uptake of transcobalamin-Cbl complex into the proximal tubule cells. Megalin is involved in the uptake and degradation of AGEs. In aging, diabetes or renal dysfunction, AGEs might overload megalin thus lowering Cbl uptake. Transcobalamin-Cbl might retain in blood. Shedding of megalin and transcobalamin receptor under glycation conditions is also a possible mechanism of this phenomenon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Molten globule of hemoglobin proceeds into aggregates and advanced glycated end products.

    Directory of Open Access Journals (Sweden)

    Afshin Iram

    Full Text Available Conformational alterations of bovine hemoglobin (Hb upon sequential addition of glyoxal over a range of 0-90% v/v were investigated. At 20% v/v glyoxal, molten globule (MG state of Hb was observed by altered tryptophan fluorescence, high ANS binding, existence of intact heme, native-like secondary structure as depicted by far-UV circular dichroism (CD and ATR-FTIR spectra as well as loss in tertiary structure as confirmed by near-UV CD spectra. In addition, size exclusion chromatography analysis depicted that MG state at 20% v/v glyoxal corresponded to expanded pre-dissociated dimers. Aggregates of Hb were detected at 70% v/v glyoxal. These aggregates of Hb had altered tryptophan environment, low ANS binding, exposed heme, increased β-sheet secondary structure, loss in tertiary structure, enhanced thioflavin T (ThT fluorescence and red shifted Congo Red (CR absorbance. On incubating Hb with 30% v/v glyoxal for 0-20 days, advanced glycation end products (AGEs were detected on day 20. These AGEs were characterised by enhanced tryptophan fluorescence at 450 nm, exposure of heme, increase in intermolecular β-sheets, enhanced ThT fluorescence and red shift in CR absorbance. Comet assay revealed aggregates and AGEs to be genotoxic in nature. Scanning electron microscopy confirmed the amorphous structure of aggregates and branched fibrils of AGEs. The transformation of α-helix to β-sheet usually alters the normal protein to amyloidogenic resulting in a variety of protein conformational disorders such as diabetes, prion and Huntington's.

  13. Effects of photobleaching on selected advanced glycation end products in the human lens

    DEFF Research Database (Denmark)

    Holm, Thomas; Raghavan, Cibin T; Nahomi, Rooban

    2015-01-01

    BackgroundCataract is the leading cause of blindness, especially in the developing world. To ease access to treatment, we have proposed that cataract could be treated non-invasively by photobleaching of the chemically modified proteins responsible for cataract formation. The present study was aimed...... at examining the optical and biochemical effects of the proposed treatment.MethodsHuman donor lenses were photobleaced using a 445 nm cw laser. Lens optical quality was assessed before and after photobleaching by light transmission and scattering. The concentration of the advanced glycation end products (AGEs...

  14. Assessment of advanced glycated end product accumulation in skin using auto fluorescence multispectral imaging.

    Science.gov (United States)

    Larsson, Marcus; Favilla, Riccardo; Strömberg, Tomas

    2017-06-01

    Several studies have shown that advanced glycation end products (AGE) play a role in both the microvascular and macrovascular complications of diabetes and are closely linked to inflammation and atherosclerosis. AGEs accumulate in skin and can be detected using their auto fluorescence (AF). A significant correlation exists between AGE AF and the levels of AGEs as obtained from skin biopsies. A commercial device, the AGE Reader, has become available to assess skin AF for clinical purposes but, while displaying promising results, it is limited to single-point measurements performed in contact to skin tissue. Furthermore, in vivo imaging of AGE accumulation is virtually unexplored. We proposed a non-invasive, contact-less novel technique for quantifying fluorescent AGE deposits in skin tissue using a multispectral imaging camera setup (MSI) during ultraviolet (UV) exposure. Imaging involved applying a region-of-interest mask, avoiding specular reflections and a simple calibration. Results of a study conducted on 16 subjects with skin types ranging from fair to deeply pigmented skin, showed that AGE measured with MSI in forearm skin was significantly correlated with the AGE reference method (AGE Reader on forearm skin, R=0.68, p=0.005). AGE measured in facial skin was borderline significantly related to AGE Reader on forearm skin (R=0.47, p=0.078). These results support the use of the technique in devices for non-touch measurement of AGE content in either facial or forearm skin tissue over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Soluble Receptor for Advanced Glycation End Products Quantifies Lung Injury in Polytraumatized Patients.

    Science.gov (United States)

    Negrin, Lukas L; Halat, Gabriel; Prosch, Helmut; Hüpfl, Michael; Hajdu, Stefan; Heinz, Thomas

    2017-05-01

    Biomarkers caused by blunt chest trauma might leak into the vascular compartment and therefore reflect the severity of parenchymal lung injury (PLI). Five promising proteins were preselected after a literature scan. The objective of our study was to identify a biomarker that is released abundantly into the serum shortly after trauma and reliably quantifies the loss of functional lung tissue. Polytraumatized patients (aged ≥18 years, Injury Severity Score [ISS] ≥16) were included in our prospective observational study if they were admitted directly to our level I trauma center during the first hour after trauma occurred. Immediately after stabilizing the patient's condition, blood samples were taken and a whole-body computed tomographic (CT) scan was obtained. Biomarker levels were measured directly after admission and on day 2. PLI volume was calculated using volumetric analysis. One hundred thirty patients met the inclusion criteria. Compared with a matched healthy control population, median levels of the soluble receptor for advanced glycation end products (sRAGE) was almost 3 times higher and decreased by 41% on day 2. Higher initial median sRAGE levels were detected in patients with PLI compared with patients without PLI and in individuals with severe PLI compared with those with mild PLI. Spearman correlation analysis and a univariate linear log regression model revealed a significant correlation/equation between initial sRAGE levels and relative PLI volume. Receiver operating characteristic (ROC) statistics identified the initial sRAGE level as an indicator of severe PLI. sRAGE levels measured shortly after trauma seem to be a promising diagnostic tool to assess the severity of PLI in polytraumatized patients. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Advanced Glycation End Product (AGE) Accumulation in the Skin is Associated with Depression: The Maastricht Study.

    Science.gov (United States)

    van Dooren, Fleur E P; Pouwer, Frans; Schalkwijk, Casper G; Sep, Simone J S; Stehouwer, Coen D A; Henry, Ronald M A; Dagnelie, Pieter C; Schaper, Nicolaas C; van der Kallen, Carla J H; Koster, Annemarie; Denollet, Johan; Verhey, Frans R J; Schram, Miranda T

    2017-01-01

    Depression is a highly prevalent disease with a high morbidity and mortality risk. Its pathophysiology is not entirely clear. However, type 2 diabetes is an important risk factor for depression. One mechanism that may explain this association may include the formation of advanced glycation end products (AGEs). We therefore investigated the association of AGEs with depressive symptoms and depressive disorder. In addition, we examined whether the potential association was present for somatic and/or cognitive symptoms of depression. Cross-sectional data were used from the Maastricht Study (N = 862, mean age 59.8 ± 8.5 years, 55% men). AGE accumulation was measured with skin autofluorescence (SAF) by use of the AGE Reader. Plasma levels of protein-bound pentosidine were measured with high-performance liquid chromatography and fluorescence detection. Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) were measured with ultraperformance liquid chromatography and tandem mass spectrometry. Depressive symptoms and depressive disorder were assessed by the nine-item Patient Health Questionnaire and the Mini-International Neuropsychiatric Interview. Higher SAF was associated with depressive symptoms (β = 0.42, 95% CI 0.12-0.73, P = .007) and depressive disorder (OR = 1.42, 95% CI 1.04-1.95, P = .028) after adjustment for age, sex, type 2 diabetes, smoking, BMI, and kidney function. Plasma pentosidine, CML, and CEL were not independently associated with depressive symptoms and depressive disorder. This study shows that AGE accumulation in the skin is independently associated with higher levels of depressive symptoms and depressive disorder. This association is present for both somatic and cognitive symptoms of depression. This might suggest that AGEs are involved in the development of depression. © 2016 Wiley Periodicals, Inc.

  17. Role of the receptor for advanced glycation end products in hepatic fibrosis.

    Science.gov (United States)

    Lohwasser, Christina; Neureiter, Daniel; Popov, Yury; Bauer, Michael; Schuppan, Detlef

    2009-12-14

    To study the role of advanced glycation end products (AGE) and their specific receptor (RAGE) in the pathogenesis of liver fibrogenesis. In vitro RAGE expression and extracellular matrix-related gene expression in both rat and human hepatic stellate cells (HSC) were measured after stimulation with the two RAGE ligands, advanced glycation end product-bovine serum albumin (AGE-BSA) and N(epsilon)-(carboxymethyl) lysine (CML)-BSA, or with tumor necrosis factor-alpha (TNF-alpha). In vivo RAGE expression was examined in models of hepatic fibrosis induced by bile duct ligation or thioacetamide. The effects of AGE-BSA and CML-BSA on HSC proliferation, signal transduction and profibrogenic gene expression were studied in vitro. In hepatic fibrosis, RAGE expression was enhanced in activated HSC, and also in endothelial cells, inflammatory cells and activated bile duct epithelia. HSC expressed RAGE which was upregulated after stimulation with AGE-BSA, CML-BSA, and TNF-alpha. RAGE stimulation with AGE-BSA and CML-BSA did not alter HSC proliferation, apoptosis, fibrogenic signal transduction and fibrosis- or fibrolysis-related gene expression, except for marginal upregulation of procollagen alpha1(I) mRNA by AGE-BSA. Despite upregulation of RAGE in activated HSC, RAGE stimulation by AGE does not alter their fibrogenic activation. Therefore, RAGE does not contribute directly to hepatic fibrogenesis.

  18. Differential effects between amphoterin and advanced glycation end products on colon cancer cells.

    Science.gov (United States)

    Kuniyasu, Hiroki; Chihara, Yoshitomo; Kondo, Hideaki

    2003-05-10

    Amphoterin is 1 ligand of the receptor for advanced glycation end products (RAGE). We studied expression of amphoterin and RAGE mRNA and proteins in colorectal carcinoma cells and investigated their associations with the invasive activities of cells exposed to advanced glycation end products (AGE). Expression of RAGE and amphoterin was examined in 4 colorectal carcinoma cell lines. All cell lines expressed both RAGE and amphoterin. The effects of RAGE and amphoterin on cell growth (MTT assay), migration (wound healing assay) and invasion (in vitro invasion assay) were tested by treatment of cells with RAGE and amphoterin antisense S-oligodeoxynucleotides (ODNs). Cell growth, migration and invasion were inhibited significantly in Colo320 and WiDr carcinoma cells treated with RAGE and amphoterin antisense S-ODNs compared with sense-treated cells. Differences in ligand activity between amphoterin and AGE were examined with AGE-bovine serum albumin (BSA). AGE-BSA decreased cell growth, migration and invasion of amphoterin antisense S-ODN-treated Colo320 and WiDr cells compared with those of cells treated with Colo320 conditioned medium. Phosphorylation of extracellular signal-regulated kinase-1/2, Rac1 and AKT and production of matrix metalloproteinase 9 were increased to a greater degree by amphoterin than by AGE-BSA. In contrast, production of inducible nitric oxide synthase and nuclear factor-kappaBp65 were increased to a greater degree by AGE-BSA than by amphoterin. Copyright 2003 Wiley-Liss, Inc.

  19. Short-term effects of dietary advanced glycation end products in rats

    DEFF Research Database (Denmark)

    Poulsen, Malene Wibe; Andersen, Jeanette Marker; Hedegaard, Rikke Susanne Vingborg

    2016-01-01

    Dietary advanced glycation end products (AGE) formed during heating of food have gained interest as potential nutritional toxins with adverse effects on inflammation and glucose metabolism. In the present study, we investigated the short-term effects of high and low molecular weight (HMW and LMW)...... the groups. In conclusion, RAGE and AGER1 expression can be influenced by a high AGE diet after only 2 weeks in proportion to MG-H1 excretion. No other short-term effects were observed.......Dietary advanced glycation end products (AGE) formed during heating of food have gained interest as potential nutritional toxins with adverse effects on inflammation and glucose metabolism. In the present study, we investigated the short-term effects of high and low molecular weight (HMW and LMW......) dietary AGE on insulin sensitivity, expression of the receptor for AGE (RAGE), the AGE receptor 1 (AGER1) and TNF-α, F2-isoprostaglandins, body composition and food intake. For 2 weeks, thirty-six Sprague-Dawley rats were fed a diet containing 20 % milk powder with different proportions of this being...

  20. Advanced glycation end-products: Mechanics of aged collagen from molecule to tissue.

    Science.gov (United States)

    Gautieri, Alfonso; Passini, Fabian S; Silván, Unai; Guizar-Sicairos, Manuel; Carimati, Giulia; Volpi, Piero; Moretti, Matteo; Schoenhuber, Herbert; Redaelli, Alberto; Berli, Martin; Snedeker, Jess G

    2017-05-01

    Concurrent with a progressive loss of regenerative capacity, connective tissue aging is characterized by a progressive accumulation of Advanced Glycation End-products (AGEs). Besides being part of the typical aging process, type II diabetics are particularly affected by AGE accumulation due to abnormally high levels of systemic glucose that increases the glycation rate of long-lived proteins such as collagen. Although AGEs are associated with a wide range of clinical disorders, the mechanisms by which AGEs contribute to connective tissue disease in aging and diabetes are still poorly understood. The present study harnesses advanced multiscale imaging techniques to characterize a widely employed in vitro model of ribose induced collagen aging and further benchmarks these data against experiments on native human tissues from donors of different age. These efforts yield unprecedented insight into the mechanical changes in collagen tissues across hierarchical scales from molecular, to fiber, to tissue-levels. We observed a linear increase in molecular spacing (from 1.45nm to 1.5nm) and a decrease in the D-period length (from 67.5nm to 67.1nm) in aged tissues, both using the ribose model of in vitro glycation and in native human probes. Multiscale mechanical analysis of in vitro glycated tendons strongly suggests that AGEs reduce tissue viscoelasticity by severely limiting fiber-fiber and fibril-fibril sliding. This study lays an important foundation for interpreting the functional and biological effects of AGEs in collagen connective tissues, by exploiting experimental models of AGEs crosslinking and benchmarking them for the first time against endogenous AGEs in native tissue. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

  1. Rifampicin reduces advanced glycation end products and activates DAF-16 to increase lifespan in Caenorhabditis elegans.

    Science.gov (United States)

    Golegaonkar, Sandeep; Tabrez, Syed S; Pandit, Awadhesh; Sethurathinam, Shalini; Jagadeeshaprasad, Mashanipalya G; Bansode, Sneha; Sampathkumar, Srinivasa-Gopalan; Kulkarni, Mahesh J; Mukhopadhyay, Arnab

    2015-06-01

    Advanced glycation end products (AGEs) are formed when glucose reacts nonenzymatically with proteins; these modifications are implicated in aging and pathogenesis of many age-related diseases including type II diabetes, atherosclerosis, and neurodegenerative disorders. Thus, pharmaceutical interventions that can reduce AGEs may delay age-onset diseases and extend lifespan. Using LC-MS(E), we show that rifampicin (RIF) reduces glycation of important cellular proteins in vivo and consequently increases lifespan in Caenorhabditis elegans by up to 60%. RIF analog rifamycin SV (RSV) possesses similar properties, while rifaximin (RMN) lacks antiglycation activity and therefore fails to affect lifespan positively. The efficacy of RIF and RSV as potent antiglycating agents may be attributed to the presence of a p-dihydroxyl moiety that can potentially undergo spontaneous oxidation to yield highly reactive p-quinone structures, a feature absent in RMN. We also show that supplementing rifampicin late in adulthood is sufficient to increase lifespan. For its effect on longevity, rifampicin requires DAF-18 (nematode PTEN) as well as JNK-1 and activates DAF-16, the FOXO homolog. Interestingly, the drug treatment modulates transcription of a different subset of DAF-16 target genes, those not controlled by the conserved Insulin-IGF-1-like signaling pathway. RIF failed to increase the lifespan of daf-16 null mutant despite reducing glycation, showing thereby that DAF-16 may not directly affect AGE formation. Together, our data suggest that the dual ability to reduce glycation in vivo and activate prolongevity processes through DAF-16 makes RIF and RSV effective lifespan-extending interventions. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  2. Reference values for the Chinese population of skin autofluorescence as a marker of advanced glycation end products accumulated in tissue.

    Science.gov (United States)

    Yue, X; Hu, H; Koetsier, M; Graaff, R; Han, C

    2011-07-01

    Advanced glycation end products play an important role in the pathophysiology of several chronic and age-related diseases, especially diabetes mellitus. Skin autofluorescence is a non-invasive method for assessing levels of tissue advanced glycation end products. This study aims to establish the normal reference value of advanced glycation end products accumulated in tissue measured by the advanced glycation end product reader--skin autofluorescence--and discusses some factors influencing it. The values of autofluorescence in healthy individuals in China were determined by the advanced glycation end product reader; age, gender, skin reflectance, smoking habits and alcohol consumption of the subjects were also recorded. The mean reference values of autofluorescence in healthy Chinese subjects are (95% confidence interval) 20-29 years: 1.54-1.62 arbitrary units; 30-39 years: 1.66-1.75; 40-49 years: 1.78-1.89; 50-59 years: 1.87-2.03; 60-69 years: 1.86-2.09; 70-79 years: 1.97-2.31. The value of autofluorescence is strongly related to age, but no significant difference between males and females were found (all P > 0.05). Autofluorescence was higher in smokers than in non-smokers (P reader reliable for lower skin reflections as well, independently of the skin colour. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

  3. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts.

    Science.gov (United States)

    Li, D X; Deng, T Z; Lv, J; Ke, J

    2014-12-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80 ± 5.50%, PRAGE participates in and exacerbates periodontium destruction.

  4. The receptor for advanced glycation end products (RAGE) and the lung.

    LENUS (Irish Health Repository)

    Buckley, Stephen T

    2010-01-01

    The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules. As a pattern-recognition receptor capable of binding a diverse range of ligands, it is typically expressed at low levels under normal physiological conditions in the majority of tissues. In contrast, the lung exhibits high basal level expression of RAGE localised primarily in alveolar type I (ATI) cells, suggesting a potentially important role for the receptor in maintaining lung homeostasis. Indeed, disruption of RAGE levels has been implicated in the pathogenesis of a variety of pulmonary disorders including cancer and fibrosis. Furthermore, its soluble isoforms, sRAGE, which act as decoy receptors, have been shown to be a useful marker of ATI cell injury. Whilst RAGE undoubtedly plays an important role in the biology of the lung, it remains unclear as to the exact nature of this contribution under both physiological and pathological conditions.

  5. Advanced glycation end products and their receptor contribute to ovarian ageing.

    Science.gov (United States)

    Stensen, Mette Haug; Tanbo, Tom; Storeng, Ritsa; Fedorcsak, Peter

    2014-01-01

    Do advanced glycation end products (AGE) and the receptor for advanced glycation end products (RAGE) affect the cells of the human ovarian follicle? AGE accumulate on the surface of ovarian granulosa-lutein (GL) cells and monocytes by binding to RAGE and other receptors with possible functional effects on these cells. AGE and RAGE are expressed in granulosa and theca cells, as well as in luteinized cells derived from the ovary. In this prospective cohort study, human follicle fluid-derived cells were isolated from aspirates of ovarian follicles of women who underwent assisted reproduction treatment. Immunofluorescence microscopy and multi-colour flow cytometry were used to determine the presence of AGE and RAGE on the surface of follicular fluid-derived cells and to characterize downstream effects of RAGE activation. GL cells and ovarian monocytes were found to contain AGE and RAGE and to bind AGE-bovine serum albumin (BSA) in correlation with the patients' chronological age. AGE-BSA and BSA failed to induce significantly the cleavage of caspase-3, phosphorylation of nuclear factor-κB or the binding of annexin V (the latter was marginally increased). AGE-fibronectin was found to induce detachment of cultured GL cells in vitro. The impact of AGE and RAGE in the ovary, shown here in cells in culture, remains to be affirmed in clinical settings. The ligands of RAGE and their effects in the ovary remain uncertain but this study implies that AGEs in the form of structural long-lived extracellular matrix proteins, rather than soluble AGEs, may play a role in the decline of ovarian function during ageing. The project was funded by the Norwegian Resource Centre for Women's Health, Oslo University Hospital. The authors have no conflicts of interests.

  6. Soft-tissue wound healing by anti-advanced glycation end-products agents.

    Science.gov (United States)

    Chang, P-C; Tsai, S-C; Jheng, Y-H; Lin, Y-F; Chen, C-C

    2014-04-01

    The blocking of advanced glycation end-products (AGE) has been shown to reduce diabetic complications and control periodontitis. This study investigated the pattern of palatal wound-healing after graft harvesting under the administration of aminoguanidine (AG), an AGE inhibitor, or N-phenacylthiazolium bromide (PTB), a glycated cross-link breaker. Full-thickness palatal excisional wounds (5.0 x 1.5 mm(2)) were created in 72 Sprague-Dawley rats. The rats received daily intraperitoneal injections of normal saline (control), AG, or PTB and were euthanized after 4 to 28 days. The wound-healing pattern was assessed by histology, histochemistry for collagen matrix deposition, immunohistochemistry for AGE and the AGE receptor (RAGE), and the expression of RAGE, as well as inflammation- and recovery-associated genes. In the first 14 days following AG or PTB treatments, wound closure, re-epithelialization, and collagen matrix deposition were accelerated, whereas AGE deposition, RAGE-positive cells, and inflammation were reduced. RAGE and tumor necrosis factor-alpha were significantly down-regulated at day 7, and heme oxygenase-1 was persistently down-regulated until day 14. The levels of vascular endothelial growth factor, periostin, type I collagen, and fibronectin were all increased at day 14. In conclusion, anti-AGE agents appeared to facilitate palatal wound-healing by reducing AGE-associated inflammation and promoting the recovery process.

  7. Effect of taurine on advanced glycation end products-induced hypertrophy in renal tubular epithelial cells

    International Nuclear Information System (INIS)

    Huang, J.-S.; Chuang, L.-Y.; Guh, J.-Y.; Yang, Y.-L.; Hsu, M.-S.

    2008-01-01

    Mounting evidence indicates that advanced glycation end products (AGE) play a major role in the development of diabetic nephropathy (DN). Taurine is a well documented antioxidant agent. To explore whether taurine was linked to altered AGE-mediated renal tubulointerstitial fibrosis in DN, we examined the molecular mechanisms of taurine responsible for inhibition of AGE-induced hypertrophy in renal tubular epithelial cells. We found that AGE (but not non-glycated BSA) caused inhibition of cellular mitogenesis rather than cell death by either necrosis or apoptosis. There were no changes in caspase 3 activity, bcl-2 protein expression, and mitochondrial cytochrome c release in BSA, AGE, or the antioxidant taurine treatments in these cells. AGE-induced the Raf-1/extracellular signal-regulated kinase (ERK) activation was markedly blocked by taurine. Furthermore, taurine, the Raf-1 kinase inhibitor GW5074, and the ERK kinase inhibitor PD98059 may have the ability to induce cellular proliferation and cell cycle progression from AGE-treated cells. The ability of taurine, GW5074, or PD98059 to inhibit AGE-induced hypertrophy was verified by the observation that it significantly decreased cell size, cellular hypertrophy index, and protein levels of RAGE, p27 Kip1 , collagen IV, and fibronectin. The results obtained in this study suggest that taurine may serve as the potential anti-fibrotic activity in DN through mechanism dependent of its Raf-1/ERK inactivation in AGE-induced hypertrophy in renal tubular epithelial cells

  8. Uptake of advanced glycation end products by proximal tubule epithelial cells via macropinocytosis.

    Science.gov (United States)

    Gallicchio, Marisa A; Bach, Leon A

    2013-12-01

    Chronic hyperglycaemia during diabetes leads to non-enzymatic glycation of proteins to form advanced glycation end products (AGEs) that contribute to nephropathy. We describe AGE uptake in LLC-PK1 and HK2 proximal tubule cell lines by macropinocytosis, a non-specific, endocytic mechanism. AGE-BSA induced dorsal circular actin ruffles and amiloride-sensitive dextran-TRITC uptake, significantly increased AGE-BSA-FITC uptake (167±20% vs BSA control, pmacropinocytosis. PAK1 and PIP5Kγ siRNA significantly decreased AGE-BSA-FITC uptake (81±6% and 64±7%, respectively, pmacropinocytosis inhibitors and a neutralising TGF-β antibody, reversed the AGE-induced decrease in surface Na(+)K(+)ATPase, suggesting AGE uptake by macropinocytosis may contribute to diabetic kidney fibrosis and/or EMT by modulating this pump. Understanding methods of cellular uptake and signalling by AGEs may lead to novel therapies for diabetic nephropathy. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Ameliorating Effect of Akebia quinata Fruit Extracts on Skin Aging Induced by Advanced Glycation End Products

    Directory of Open Access Journals (Sweden)

    Seoungwoo Shin

    2015-11-01

    Full Text Available The accumulation of free radicals and advanced glycation end products (AGEs in the skin plays a very important role in skin aging. Both are known to interact with each other. Therefore, natural compounds or extracts that possess both antioxidant and antiglycation activities might have great antiageing potential. Akebia quinata fruit extract (AQFE has been used to treat urinary tract inflammatory disease in traditional Korean and Chinese medicines. In the present study, AQFE was demonstrated to possess antioxidant and antiglycation activity. AQFE protects human dermal fibroblasts (HDFs from oxidative stress and inhibits cellular senescence induced by oxidative stress. We also found that AQFE inhibits glycation reaction between BSA and glucose. The antiglycation activity of AQFE was dose-dependent. In addition, the antiglycation activity of AQFE was confirmed in a human skin explant model. AQFE reduced CML expression and stimulated fibrillin-1 expression in comparison to the methyglyoxal treatment. In addition, the possibility of the extract as an anti-skin aging agent has also been clinically validated. Our analysis of the crow’s feet wrinkle showed that there was a decrease in the depth of deep furrows in RI treated with AQFE cream over an eight-week period. The overall results suggest that AQFE may work as an anti-skin aging agent by preventing oxidative stress and other complications associated with AGEs formation.

  10. Regulation of human mononuclear phagocyte migration by cell surface-binding proteins for advanced glycation end products.

    OpenAIRE

    Schmidt, A M; Yan, S D; Brett, J; Mora, R; Nowygrod, R; Stern, D

    1993-01-01

    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 ...

  11. The distribution of advanced glycation end products and their receptor in the gastrointestinal tract in the rats

    DEFF Research Database (Denmark)

    Chen, Pengmin; Zhao, Jingbo; Gregersen, Hans

    2012-01-01

    To investigate the distribution of advanced glycation end products (AGEs) and their receptor (RAGE) in the gastrointestinal (GI) tract to provide a basis for further study of the association between AGE/RAGE and diabetic GI dysfunction. METHODS: The distribution of AGEs [N epsilon-(carboxymethyl)......To investigate the distribution of advanced glycation end products (AGEs) and their receptor (RAGE) in the gastrointestinal (GI) tract to provide a basis for further study of the association between AGE/RAGE and diabetic GI dysfunction. METHODS: The distribution of AGEs [N epsilon...

  12. Gingival advanced glycation end-products in diabetes mellitus-associated chronic periodontitis: an immunohistochemical study.

    Science.gov (United States)

    Zizzi, A; Tirabassi, G; Aspriello, S D; Piemontese, M; Rubini, C; Lucarini, G

    2013-06-01

    The accumulation of advanced glycation end-products (AGEs) seems to play an important role in the development of diabetes mellitus (DM)-associated periodontitis; however, some aspects of this issue are still scarcely known, such as the expression of AGEs in type 1 DM-associated periodontitis and the clinical factors able to affect their accumulation. This study aimed to clarify these points by evaluating the expression of AGEs in DM-associated periodontitis. Sixteen systemically and periodontally healthy subjects and 48 subjects suffering from generalized, severe, chronic periodontitis (16 with type 1 DM, 16 with type 2 DM and 16 systemically healthy subjects) were studied clinically, periodontally and metabolically. The immunohistochemical expression of AGEs in gingival tissues was also evaluated. Subjects affected with type 1 DM presented a significantly higher percentage of AGE-positive cells than did subjects affected with type 2 DM, not only in the epithelium, but also in vessels and fibroblasts. A positive and significant correlation was found between gingival expression of AGEs and length of time affected with DM both in type 1 and type 2 DM; glycated hemoglobin, lipid profile, body mass index and age did not correlate significantly with gingival AGEs in any of the classes of subjects studied. Gingival AGEs are increased in both type 1 and type 2 DM-associated periodontitis; however, the clinical parameter that determines their accumulation, and therefore their degree of influence on the development of DM-associated periodontitis, may be the duration of DM. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Accumulation of Advanced Glycation End Products as a Molecular Mechanism for Aging as a Risk Factor in Osteoarthritis

    NARCIS (Netherlands)

    Groot, J. de; Verzijl, N.; Wenting-Wijk, M.J.G. van; Jacobs, K.M.G.; El, B. van; Roermund, P.M. van; Bank, R.A.; Bijlsma, J.W.J.; TeKoppele, J.M.; Lafeber, F.P.J.G.

    2004-01-01

    Objective. Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting the elderly. Its etiology is largely unknown, but age is the most prominent risk factor. The current study was designed to test whether accumulation of advanced glycation end products (AGEs), which

  14. Association of Polymorphism in the Receptor for Advanced Glycation End Products (RAGE) Gene with Circulating RAGE Levels

    NARCIS (Netherlands)

    Gaens, Katrien H. J.; Ferreira, Isabel; van der Kallen, Carla J. H.; van Greevenbroek, Marleen M. J.; Blaak, Ellen E.; Feskens, Edith J. M.; Dekker, Jacqueline M.; Nijpels, Giel; Heine, Robert J.; 't Hart, Leen M.; de Groot, Philip G.; Stehouwer, Coen D. A.; Schalkwijk, Casper G.

    2009-01-01

    Objective: The receptor for advanced glycation end products (RAGE)-ligand interaction has been linked to vascular complications. The family of soluble forms of RAGE (sRAGE) consists of splice variants and proteolytically cleaved and shed forms of RAGE. sRAGE may be a reflection of cell-bound RAGE.

  15. Receptor for Advanced Glycation End Products Facilitates Host Defense during Escherichia coli-Induced Abdominal Sepsis in Mice

    NARCIS (Netherlands)

    van Zoelen, Marieke A. D.; Schmidt, Ann-Marie; Florquin, Sandrine; Meijers, Joost C.; de Beer, Regina; de Vos, Alex F.; Nawroth, Peter P.; Bierhaus, Angelika; van der Poll, Tom

    2009-01-01

    Background. The receptor for advanced glycation end products (RAGE) mediates a variety of inflammatory responses. Methods. To determine the role of RAGE in the innate immune response to abdominal sepsis caused by Escherichia coli, RAGE-deficient (RAGE(-/-)) and normal wild-type mice were

  16. Advanced glycation end products, measured in skin, vs. HbA1c in children with type 1 diabetes mellitus

    NARCIS (Netherlands)

    Banser, Alena; Naafs, Jolanda C.; Hoorweg-Nijman, Jantine J. G.; van de Garde, Ewoudt M. W.; van der Vorst, Marja M. J.

    2016-01-01

    Background and objectiveAdvanced glycation end products (AGEs) are considered major contributors to microvascular and macrovascular complications in adult patients with diabetes mellitus. AGEs can be measured non-invasively with skin autofluorescence (sAF). The primary aim was to determine sAF

  17. The influence of body mass index on the accumulation of advanced glycation end products in hemodialysis patients

    NARCIS (Netherlands)

    Arsov, S.; Trajceska, L.; van Oeveren, W.; Smit, A. J.; Dzekova, P.; Stegmayr, B.; Sikole, A.; Rakhorst, G.; Graaff, R.

    BACKGROUND/OBJECTIVES: The level of skin autofluorescence (AF) at a given moment is an independent predictor of mortality in hemodialysis (HD) patients. Skin AF is a measure of the accumulation of advanced glycation end products (AGEs). The aim of the study was to estimate the influence of nutrition

  18. Biodistribution of the 18F-labelled advanced glycation end products Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL)

    International Nuclear Information System (INIS)

    Bergmann, R.; Helling, R.; Henle, T.; Heichert, C.; Scheunemann, M.; Maeding, P.; Wittrisch, H.; Johannsen, B.

    2002-01-01

    After synthesis of fluorine-18 labelled analogues [ 18 F]fluorobenzoylation at the α-amino group, biodistribution and elimination of individual advanced glycation end products, namely N ε -carboxymethyllysine and N ε -carboxyethyllysine, was studied in comparison to lysine in rats after intravenous injection using positron emission tomography. (orig.)

  19. Serum levels of advanced glycation end products are associated with left ventricular diastolic function in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Berg, T J; Snorgaard, O; Faber, J

    1999-01-01

    Impairment of left ventricular diastolic function, possibly caused by increased collagen cross-linking of the cardiac muscle, is common in patients with type 1 diabetes even without coronary artery disease. Advanced glycation end products (AGEs) cross-link tissue collagen and are found within...

  20. Glycation inhibitors extend yeast chronological lifespan by reducing advanced glycation end products and by back regulation of proteins involved in mitochondrial respiration.

    Science.gov (United States)

    Kazi, Rubina S; Banarjee, Reema M; Deshmukh, Arati B; Patil, Gouri V; Jagadeeshaprasad, Mashanipalya G; Kulkarni, Mahesh J

    2017-03-06

    Advanced Glycation End products (AGEs) are implicated in aging process. Thus, reducing AGEs by using glycation inhibitors may help in attenuating the aging process. In this study using Saccharomyces cerevisiae yeast system, we show that Aminoguanidine (AMG), a well-known glycation inhibitor, decreases the AGE modification of proteins in non-calorie restriction (NR) (2% glucose) and extends chronological lifespan (CLS) similar to that of calorie restriction (CR) condition (0.5% glucose). Proteomic analysis revealed that AMG back regulates the expression of differentially expressed proteins especially those involved in mitochondrial respiration in NR condition, suggesting that it switches metabolism from fermentation to respiration, mimicking CR. AMG induced back regulation of differentially expressed proteins could be possibly due to its chemical effect or indirectly by glycation inhibition. To delineate this, Metformin (MET), a structural analog of AMG and a mild glycation inhibitor and Hydralazine (HYD), another potent glycation inhibitor but not structural analog of AMG were used. HYD was more effective than MET in mimicking AMG suggesting that glycation inhibition was responsible for restoration of differentially expressed proteins. Thus glycation inhibitors particularly AMG, HYD and MET extend yeast CLS by reducing AGEs, modulating the expression of proteins involved in mitochondrial respiration and possibly by scavenging glucose. This study reports the role of glycation in aging process. In the non-caloric restriction condition, carbohydrates such as glucose promote protein glycation and reduce CLS. While, the inhibitors of glycation such as AMG, HYD, MET mimic the caloric restriction condition by back regulating deregulated proteins involved in mitochondrial respiration which could facilitate shift of metabolism from fermentation to respiration and extend yeast CLS. These findings suggest that glycation inhibitors can be potential molecules that can be used

  1. Increased levels of circulating advanced glycation end-products in menopausal women with osteoporosis.

    Science.gov (United States)

    Yang, Deng-Ho; Chiang, Tsay-I; Chang, I-Chang; Lin, Fu-Huang; Wei, Cheng-Chung; Cheng, Ya-Wen

    2014-01-01

    Advanced glycation end-products (AGEs) can accumulate in organs and tissues during ageing and diabetes. Increased levels of AGEs are found in the bone tissue of patients with osteoporosis. The purpose of this study was to evaluate circulating AGEs in patients with osteoporosis. We evaluated plasma AGEs, osteoporosis-related biomarkers, and bone mass in 82 menopausal women with osteoporosis or osteopenia, 16 young women with osteopenia, and 43 healthy women without osteoporosis or osteopenia. Higher levels of serum AGEs were found in the osteoporosis or osteopenia group compared to healthy women (P 8.12 U/mL) had a 5.34-fold risk of osteopenia regarding lumbar spine T-score and a 3.31-fold risk of osteopenia regarding the hip T-score. Serum AGEs could be used to monitor the severity and progression of osteoporosis. An increased serum level of AGEs was associated with impaired bone formation and was a risk factor for the development of osteoporosis. Targeting AGEs may represent a novel therapeutic approach for primary or secondary osteoporosis.

  2. Receptor for Advanced Glycation End Products and Its Involvement in Inflammatory Diseases

    Directory of Open Access Journals (Sweden)

    Yaw Kuang Chuah

    2013-01-01

    Full Text Available The receptor for advanced glycation end products (RAGE is a transmembrane receptor of the immunoglobulin superfamily, capable of binding a broad repertoire of ligands. RAGE-ligands interaction induces a series of signal transduction cascades and lead to the activation of transcription factor NF-κB as well as increased expression of cytokines, chemokines, and adhesion molecules. These effects endow RAGE with the role in the signal transduction from pathogen substrates to cell activation during the onset and perpetuation of inflammation. RAGE signaling and downstream pathways have been implicated in a wide spectrum of inflammatory-related pathologic conditions such as arteriosclerosis, Alzheimer's disease, arthritis, acute respiratory failure, and sepsis. Despite the significant progress in other RAGE studies, the functional importance of the receptor in clinical situations and inflammatory diseases still remains to be fully realized. In this review, we will summarize current understandings and lines of evidence on the molecular mechanisms through which RAGE signaling contributes to the pathogenesis of the aforementioned inflammation-associated conditions.

  3. Receptor for advanced glycation end products (RAGE) knockout reduces fetal dysmorphogenesis in murine diabetic pregnancy.

    Science.gov (United States)

    Ejdesjö, Andreas; Brings, Sebastian; Fleming, Thomas; Fred, Rikard G; Nawroth, Peter P; Eriksson, Ulf J

    2016-07-01

    The receptor for Advanced Glycation End products (RAGE) is implicated in the pathogenesis of diabetic complications, but its importance in diabetic embryopathy is unclear. We therefore investigated the role of RAGE in diabetic embryopathy using streptozotocin induced diabetes in female wild type (WT) C57Bl/6N and RAGE knockout C57Bl/6N (RAGE(-/-)) mice, mated with control males of the same genotype. Maternal diabetes induced more fetal resorption and malformation (facial skeleton, neural tube) in the WT than in the RAGE(-/-) fetuses. Maternal plasma glucose and methylgyoxal concentrations, as well as embryonic N(ε)-carboxymethyl-lysine (CML) levels were increased to the same extent in diabetic WT and RAGE(-/-) pregnancy. However, maternal diabetes induced increased fetal hepatic isoprostane 8-iso-PGF2α levels (oxidative stress marker) and embryonic activation of NFκB in WT only (not in RAGE(-/-) embryos). The association between RAGE knockout and diminished embryonic dysmorphogenesis in diabetic pregnancy suggests that embryonic RAGE activation is involved in diabetic embryopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Receptor for advanced glycation end products (RAGE)-mediated cytotoxicity of 3-hydroxypyridinium derivatives.

    Science.gov (United States)

    Murakami, Yoto; Fujino, Takayuki; Hasegawa, Toshiki; Kurachi, Ryotaro; Miura, Aya; Daikoh, Takumi; Usui, Teruyuki; Hayase, Fumitaka; Watanabe, Hirohito

    2018-02-01

    Advanced glycation end products (AGEs) formed from glyceraldehyde (Gcer) and glycolaldehyde (Gcol) are involved in the pathogenesis of diabetic complications, via interactions with a receptor for AGEs (RAGE). In this study, we aimed to elucidate the RAGE-binding structure in Gcer and Gcol-derived AGEs and identify the minimal moiety recognized by RAGE. Among Gcer and Gcol-derived AGEs, GLAP (glyceraldehyde-derived pyridinium) and GA-pyridine elicited toxicity in PC12 neuronal cells. The toxic effects of GLAP and GA-pyridine were suppressed in the presence of anti-RAGE antibody or the soluble form of RAGE protein. Furthermore, the cytotoxicity test using GLAP analog compounds indicated that the 3-hydroxypyridinium (3-HP) structure is sufficient for RAGE-dependent toxicity. Surface plasmon resonance analysis showed that 3-HP derivatives directly interact with RAGE. These results indicate that GLAP and GA-pyridine are RAGE-binding epitopes, and that 3-HP, a common moiety of GLAP and GA-pyridine, is essential for the interaction with RAGE.

  5. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

    International Nuclear Information System (INIS)

    Li, D.X.; Deng, T.Z.; Lv, J.; Ke, J.

    2014-01-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction

  6. Advanced glycation end products: a link between periodontitis and diabetes mellitus?

    Science.gov (United States)

    Gurav, Abhijit N

    2013-09-01

    Advanced glycation end products (AGEs) are synthesized via the non enzymaticglycation and oxidation of proteins, lipids and nucleic acids. The production of AGEs is particularly enhanced in chronic hyperglycemia, as in diabetes mellitus (DM). The formation of irreversible AGEs affects the tissues by compromising the physiologic and mechanical functions, as a result of defective constitution of the extracellular matrix (ECM) components. Periodontitis is an inflammatory disease of microbial origin, resulting in devastation of the tooth supporting apparatus. This disease condition has severe implicationsin subjects with DM, since the tooth supporting tissuescontain ECM targeted by AGE. There is miniscule literature regarding the contribution of AGE to periodontal disease in patients with DM. The purpose of this review is to address the prejudicial role of AGEs in relation to various tissue components. This paper is an attempt to elucidatethe possible link of AGEs between periodontitis and DM. The exploration of novel therapeutic strategies to target AGEs for the treatment of periodontitis in DM subjects is certainly intriguing.

  7. Advanced glycation end products (AGEs and their receptor (RAGE induce apoptosis of periodontal ligament fibroblasts

    Directory of Open Access Journals (Sweden)

    D.X. Li

    2014-12-01

    Full Text Available Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL fibroblasts induced by advanced glycation end products (AGEs and their receptor (RAGE. We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA, bovine serum albumin (BSA alone, or given no treatment (control. Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01 and increased apoptosis (11.31±1.73%, P<0.05. Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction.

  8. Expression and function of receptors for advanced glycation end products in bovine corneal endothelial cells.

    Science.gov (United States)

    Kaji, Yuichi; Amano, Shiro; Usui, Tomohiko; Oshika, Tetsuro; Yamashiro, Kenji; Ishida, Susumu; Suzuki, Kaori; Tanaka, Sumiyoshi; Adamis, Anthony P; Nagai, Ryoji; Horiuchi, Seiko

    2003-02-01

    The corneal endothelium is a target of the aging process. This study was undertaken to reveal the relationship between corneal endothelial cell (CEC) death and the accumulation of advanced glycation end products (AGEs), by investigating the possible mechanism of accumulation of AGE in CECs and its effects on CEC death. First, the in vivo expression of the receptor was investigated for AGE (RAGE) and galectin-3, both receptors for AGE, at both the mRNA and protein levels. Second, AGEs were added to the culture media of the cultured CECs, and the uptake of AGEs, the generation of reactive oxygen species, and the induction of apoptosis were investigated. Immunohistochemistry and RT-PCR demonstrated that both RAGE and galectin-3 were expressed in bovine CECs. After administration of AGE-modified bovine serum albumin to the culture medium, uptake of AGE was observed in the cytoplasm of the cultured bovine CECs. In addition, with increasing concentration of AGEs, the generation of reactive oxygen and the number of apoptotic cells also increased. These results show that the accumulation of AGEs in CECs induced apoptosis, in part, by increasing cellular oxidative stress. The accumulation of AGEs in the CECs of elderly patients may be involved in the loss of CECs during the aging process.

  9. Inhibitory effect of GSPE on RAGE expression induced by advanced glycation end products in endothelial cells.

    Science.gov (United States)

    Zhang, Feng-Lei; Gao, Hai-Qing; Shen, Lin

    2007-10-01

    Advanced glycation end products' (AGEs) engagement of a cell-surface receptor for AGEs (RAGE) has been causally implicated in the pathogenesis of diabetic vascular complications via induction of reactive oxygen species (ROS) and subsequent alteration of many gene expressions, including RAGE itself. Grapeseed proanthocyanidin extract (GSPE), which is a naturally occurring polyphenolic compound, has been reported to possess potent radical-scavenging and antioxidant properties and to display significant cardiovascular protective action. In this study, we investigated whether GSPE could inhibit AGE-induced RAGE expression through interference with ROS generation in human umbilical-vein endothelial cells (HUVECs). AGE-modified bovine serum albumin (AGE-BSA) was prepared by incubating BSA with high-concentration glucose. Stimulation of cultured HUVECs with 200 microg/mL of AGE-BSA significantly enhanced intracellular ROS formation and subsequently upregulated the protein and mRNA expression of RAGE; unmodified BSA and GSPE alone had no effect. However, GSPE preincubation markedly downregulated AGE-induced surface expression of RAGE in a time- and concentration-dependent manner. In AGE-stimulated HUVECs, GSPE also dose-dependently decreased RAGE mRNA levels and inhibited AGE-induced ROS generation at defined time periods. These results demonstrate that GSPE can inhibit enhanced RAGE expression in AGE-exposed endothelial cells by suppressing ROS generation, thereby limiting the AGE-RAGE interaction. Hence, GSPE may have therapeutic potential in the prevention and treatment of vascular complications in diabetic patients.

  10. Phytochemicals Against Advanced Glycation End Products (AGEs) and the Receptor System.

    Science.gov (United States)

    Yamagishi, Sho-Ichi; Matsui, Takanori; Ishibashi, Yuji; Isami, Fumiyuki; Abe, Yumi; Sakaguchi, Tatsuya; Higashimoto, Yuichiro

    2017-01-01

    Reducing sugars can react non-enzymatically with amino groups of proteins and lipids to form irreversibly cross-linked macroprotein derivatives called as advanced glycation end products (AGEs). Cross-linking modification of extracellular matrix proteins by AGEs deteriorate their tertiary structural integrity and function, contributing to aging-related organ damage and diabetes-associated complications, such as cardiovascular disease (CVD). Moreover, engagement of receptor for AGEs, RAGE with the ligands evoke oxidative stress generation and inflammatory, thrombotic and fibrotic reactions in various kinds of tissues, further exacerbating the deleterious effects of AGEs on multiple organ systems. So the AGE-RAGE axis is a novel therapeutic target for numerous devastating disorders. Several observational studies have shown the association of dietary consumption of fruits and vegetables with the reduced risk of CVD in a general population. Although beneficial effects of fruits and vegetables against CVD could mainly be ascribed to its anti-oxidative properties, blockade of the AGERAGE axis by phytochemicals may also contribute to cardiovascular event protection. Therefore, in this review, we focus on 4 phytochemicals (quercetin, sulforaphane, iridoids, and curcumin) and summarize their effects on AGE formation as well as RAGE-mediated signaling pathway in various cell types and organs, including endothelial cells, vessels, and heart. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Sesamin Ameliorates Advanced Glycation End Products-Induced Pancreatic β-Cell Dysfunction and Apoptosis

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    Xiang Kong

    2015-06-01

    Full Text Available Advanced glycation end products (AGEs, the direct modulators of β-cells, have been shown to cause insulin-producing β-cell dysfunction and apoptosis through increase of intracellular reactive oxygen species (ROS production. Sesamin has been demonstrated to possess antioxidative activity. This study was designed to investigate whether sesamin protects against AGEs-evoked β-cell damage via its antioxidant property. The effects of sesamin were examined in C57BL/6J mice and MIN6 cell line. In in vivo studies, mice were intraperitoneally injected with AGEs (120 mg/kg and orally treated with sesamin (160 mg/kg for four weeks. Intraperitoneal glucose tolerance and insulin releasing tests were performed. Insulin content, ROS generation and β-cell apoptosis in pancreatic islets were also measured. In in vitro studies, MIN6 cells were pretreated with sesamin (50 or 100 μM and then exposed to AGEs (200 mg/L for 24 h. Insulin secretion, β-cell death, ROS production as well as expression and activity of NADPH oxidase were determined. Sesamin treatment obviously ameliorated AGE-induced β-cell dysfunction and apoptosis both in vivo and in vitro. These effects were associated with decreased ROS production, down-regulated expression of p67phox and p22phox, and reduced NADPH oxidase activity. These results suggest that sesamin protects β-cells from damage caused by AGEs through suppressing NADPH oxidase-mediated oxidative stress.

  12. Advanced glycation end products affect cholesterol homeostasis by impairing ABCA1 expression on macrophages.

    Science.gov (United States)

    Kamtchueng Simo, Olivier; Ikhlef, Souade; Berrougui, Hicham; Khalil, Abdelouahed

    2017-08-01

    Reverse cholesterol transport (RCT), which is intimately linked to high-density lipoproteins (HDLs), plays a key role in cholesterol homeostasis and the prevention of atherosclerosis. The goal of the present study was to investigate the effect of aging and advanced glycation end products (AGEs) on RCT as well as on other factors that may affect the antiatherogenic property of HDLs. The transfer of macrophage-derived cholesterol to the plasma and liver and then to the feces for elimination was significantly lower in aged mice than in young mice. Chronic injection of d -galactose (D-gal) or AGEs also significantly reduced RCT (65.3% reduction in [ 3 H]cholesterol levels in the plasma of D-gal-treated mice after 48 h compared with control mice, P cholesterol levels in the plasma, although the levels were lower than those of control mice. The in vitro incubation of HDLs with dicarbonyl compounds increased the carbonyl and conjugated diene content of HDLs and significantly reduced PON1 paraoxonase activity (87.4% lower than control HDLs, P cholesterol (69.1% decrease, P < 0.0001). Our results showed, for the first time, that RCT is altered with aging and that AGEs contribute significantly to this alteration.

  13. Advanced glycation end products assessed by skin autofluorescence: a new marker of diabetic foot ulceration.

    Science.gov (United States)

    Vouillarmet, Julien; Maucort-Boulch, Delphine; Michon, Paul; Thivolet, Charles

    2013-07-01

    Accumulation of advanced glycation end products (AGEs) may contribute to diabetic foot ulceration (DFU). Our goal was to determine whether AGEs measurement by skin autofluorescence (SAF) would be an additional marker for DFU management. We performed SAF analysis in 66 patients with a history of DFU prospectively included and compared the results with those of 84 control patients with diabetic peripheral neuropathy without DFU. We then assessed the prognostic value of SAF levels on the healing rate in the DFU group. Mean SAF value was significantly higher in the DFU group in comparison with the control group, even after adjustment for other diabetes complications (3.2±0.6 arbitrary units vs. 2.9±0.6 arbitrary units; P=0.001). In the DFU group, 58 (88%) patients had an active wound at inclusion. The mean DFU duration was 14±13 weeks. The healing rate was 47% after 2 months of appropriate foot care. A trend for a correlation between SAF levels and healing time in DFU subjects was observed but was not statistically significant (P=0.06). Increased SAF levels are associated with neuropathic foot complications in diabetes. Use of SAF measurement to assess foot vulnerability and to predict DFU events in high-risk patients appears to be promising.

  14. Role of Reactive Oxygen Species and Advanced Glycation End Products in the Malfunctioning of Dental Implants.

    Science.gov (United States)

    Guo, M; Liu, L; Zhang, J; Liu, M

    2015-09-01

    In the last decade, dental implants have emerged as a crucial modality and serve as an individual form of therapy for dental failure. However, disparities in host responses have led to peri-implantitis and implant failure. The pathological mechanisms driving peri-implantitis remain largely unknown. In this study, we evaluated the role of oxidative stress and advanced glycation end products (AGE) in the progression of peri-implantitis and dental implants failure, compared with chronic periodontal disease. Three patient groups (peri-implantitis, chronic periodontal disease and control), each with 10 subjects (7M/3F) and average age ranging from 40-60 years were selected for analysis. Salivary oxidative stress and tissue AGE levels were analysed by probing for reactive oxygen species (ROS) and Maillard reaction-related fluorescence, respectively. We observed significant increase (> 2-fold) in oxidative stress and AGE levels in patients with peri-implantitis and chronic periodontal disease compared to controls, with chronic periodontal disease having the highest levels. In addition, we observed a strong positive correlation (r = 0.94) between oxidative stress and AGE levels in the patients. We propose that increased AGE levels and oxidative stress, although not the only pathway, are significant mediators in the pathogenesis of peri-implantitis. Altering them may potentially be used in combination with other modalities to manage peri-implantitis.

  15. Advanced glycation end products delay corneal epithelial wound healing through reactive oxygen species generation.

    Science.gov (United States)

    Shi, Long; Chen, Hongmei; Yu, Xiaoming; Wu, Xinyi

    2013-11-01

    Delayed healing of corneal epithelial wounds is a serious complication in diabetes. Advanced glycation end products (AGEs) are intimately associated with the diabetic complications and are deleterious to the wound healing process. However, the effect of AGEs on corneal epithelial wound healing has not yet been evaluated. In the present study, we investigated the effect of AGE-modified bovine serum albumin (BSA) on corneal epithelial wound healing and its underlying mechanisms. Our data showed that AGE-BSA significantly increased the generation of intracellular ROS in telomerase-immortalized human corneal epithelial cells. However, the generation of intracellular ROS was completely inhibited by antioxidant N-acetylcysteine (NAC), anti-receptor of AGEs (RAGE) antibodies, or the inhibitor of NADPH oxidase. Moreover, AGE-BSA increased NADPH oxidase activity and protein expression of NADPH oxidase subunits, p22phox and Nox4, but anti-RAGE antibodies eliminated these effects. Furthermore, prevention of intracellular ROS generation using NAC or anti-RAGE antibodies rescued AGE-BSA-delayed epithelial wound healing in porcine corneal organ culture. In conclusion, our results demonstrated that AGE-BSA impaired corneal epithelial wound healing ex vivo. AGE-BSA increased intracellular ROS generation through NADPH oxidase activation, which accounted for the delayed corneal epithelial wound healing. These results may provide better insights for understanding the mechanism of delayed healing of corneal epithelial wounds in diabetes.

  16. Advanced Glycation End Products: Link between Diet and Ovulatory Dysfunction in PCOS?

    Directory of Open Access Journals (Sweden)

    Deepika Garg

    2015-12-01

    Full Text Available PCOS is the most common cause of anovulation in reproductive-aged women with 70% experiencing ovulatory problems. Advanced glycation end products are highly reactive molecules that are formed by non-enzymatic reactions of sugars with proteins, nucleic acids and lipids. AGEs are also present in a variety of diet where substantial increase in AGEs can result due to thermal processing and modifications of food. Elevation in bodily AGEs, produced endogenously or absorbed exogenously from high-AGE diets, is further exaggerated in women with PCOS and is associated with ovulatory dysfunction. Additionally, increased expression of AGEs as pro-inflammatory receptors in the ovarian tissue has been observed in women with PCOS. In this review, we summarize the role of dietary AGEs as mediators of metabolic and reproductive alterations in PCOS. Once a mechanistic understanding of the relationship between AGEs and anovulation is established, there is a promise that such knowledge will contribute to the subsequent development of targeted pharmacological therapies that will treat anovulation and improve ovarian health in women with PCOS.

  17. Do Advanced Glycation End Products (AGEs) Contribute to the Comorbidities of Polycystic Ovary Syndrome (PCOS)?

    Science.gov (United States)

    Rutkowska, Aleksandra Zofia; Diamanti-Kandarakis, Evanthia

    2016-01-01

    Advanced glycation end products (AGEs) are formed both during the endogenous and exogenous reactions and are implicated in the process of ageing, pathogenesis of diabetes, atherosclerosis, female fertility, and cancers. Food and smoking are the most important sources of exogenous AGEs in daily life. The biochemical composition of meal, cooking methods, time and temperature of food preparation may impact AGEs formation, therefore Western-type diet, rich in animal-derived products as well as in fast foods seems to be the main source of AGEs. Both, endogenous and exogenous AGEs can act intracellularly or during serum interaction with cell surface receptors called RAGE influencing variety of molecular pathways. Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age. The aetiology of this disorder remains unclear, however the environmental and genetic factors may play an important role in its pathogenesis. Nevertheless, PCOS women have increased factors for reproductive and cardiometabolic comorbidities. AGEs can contribute to the pathogenesis of PCOS as well as its consequences. It has been shown that chronic inflammation and increased oxidative stress may be a link between the mechanisms of AGEs action and the metabolic and reproductive consequences of PCOS. This review highlights that high dietary AGEs intake promotes deteriorating biological effects in women with PCOS, whereas AGEs restriction seems to have beneficial impact on women health. Better understanding AGEs formation and biochemistry as well as AGE-mediated pathophysiological mechanisms may open new therapeutic avenues converging to the achievement of the complete treatment of PCOS and its consequences.

  18. Advanced Glycation End Products: Link between Diet and Ovulatory Dysfunction in PCOS?

    Science.gov (United States)

    Garg, Deepika; Merhi, Zaher

    2015-12-04

    PCOS is the most common cause of anovulation in reproductive-aged women with 70% experiencing ovulatory problems. Advanced glycation end products are highly reactive molecules that are formed by non-enzymatic reactions of sugars with proteins, nucleic acids and lipids. AGEs are also present in a variety of diet where substantial increase in AGEs can result due to thermal processing and modifications of food. Elevation in bodily AGEs, produced endogenously or absorbed exogenously from high-AGE diets, is further exaggerated in women with PCOS and is associated with ovulatory dysfunction. Additionally, increased expression of AGEs as pro-inflammatory receptors in the ovarian tissue has been observed in women with PCOS. In this review, we summarize the role of dietary AGEs as mediators of metabolic and reproductive alterations in PCOS. Once a mechanistic understanding of the relationship between AGEs and anovulation is established, there is a promise that such knowledge will contribute to the subsequent development of targeted pharmacological therapies that will treat anovulation and improve ovarian health in women with PCOS.

  19. Advanced glycation end products enhance reactive oxygen and nitrogen species generation in neutrophils in vitro.

    Science.gov (United States)

    Bansal, Savita; Siddarth, Manushi; Chawla, Diwesh; Banerjee, Basu D; Madhu, S V; Tripathi, Ashok K

    2012-02-01

    Increased oxidative stress (OS) in diabetes mellitus is one of the major factors leading to diabetic pathology. However, the mediators and mechanism that provoke OS in diabetes is not fully understood, and it is possible that accumulation of advanced glycation end products (AGEs) formed secondary to hyperglycemic conditions may incite circulating polymorphonuclear neutrophils (PMN) to generate reactive oxygen species (ROS). In this report, we aim to investigate the effect of AGE on reactive oxygen and nitrogen species generation and subsequent OS in PMN. AGE-HSA exert dose- and time-dependent enhancement of ROS and reactive nitrogen intermediates (RNI) generation by PMN. Increased ROS and RNI generation were found to be mediated through the upregulation of NADPH oxidase and inducible nitric oxide synthase (iNOS), respectively, as evident from the fact that AGE-treated neutrophils failed to generate ROS and RNI in presence of diphenyleneiodonium, a flavoprotein inhibitor for both enzymes. Further increased generation of ROS and RNI ceased when the cells were incubated with anti-RAGE antibody suggesting the involvement of AGE-RAGE interaction. Also increased malondialdehyde (MDA) and protein carbonyl formation in AGE-exposed PMN suggest induction of OS by AGE. This study provides evidence that AGEs may play a key role in the induction of oxidative stress through the augmentation of PMN-mediated ROS and RNI generation and this may be in part responsible for development of AGE-induced diabetic pathology.

  20. Receptor for Advanced Glycation End Products (RAGE) Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia.

    Science.gov (United States)

    Achouiti, Ahmed; de Vos, Alex F; van 't Veer, Cornelis; Florquin, Sandrine; Tanck, Michael W; Nawroth, Peter P; Bierhaus, Angelika; van der Poll, Tom; van Zoelen, Marieke A D

    2016-01-01

    Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE) is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed to investigate the role of RAGE in the host response to Klebsiella (K.) pneumoniae pneumonia and intransally inoculated rage gene deficient (RAGE-/-) and normal wild-type (Wt) mice with K. pneumoniae. Klebsiella pneumonia resulted in an increased pulmonary expression of RAGE. Furthermore, the high-affinity RAGE ligand high mobility group box-1 was upregulated during K. pneumoniae pneumonia. RAGE deficiency impaired host defense as reflected by a worsened survival, increased bacterial outgrowth and dissemination in RAGE-/- mice. RAGE-/- neutrophils showed a diminished phagocytosing capacity of live K. pneumoniae in vitro. Relative to Wt mice, RAGE-/- mice demonstrated similar lung inflammation, and slightly elevated-if any-cytokine and chemokine levels and unchanged hepatocellular injury. In addition, RAGE-/- mice displayed an unaltered response to intranasally instilled Klebsiella lipopolysaccharide (LPS) with respect to pulmonary cell recruitment and local release of cytokines and chemokines. These data suggest that (endogenous) RAGE protects against K. pneumoniae pneumonia. Also, they demonstrate that RAGE contributes to an effective antibacterial defense during K. pneumoniae pneumonia, at least partly via its participation in the phagocytic properties of professional granulocytes. Additionally, our results indicate that RAGE is not essential for the induction of a local and systemic inflammatory response to either intact Klebsiella or Klebsiella LPS.

  1. Blockade of advanced glycation end product formation attenuates bleomycin-induced pulmonary fibrosis in rats

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    Liu Dai-Shun

    2009-06-01

    Full Text Available Abstract Background Advanced glycation end products (AGEs have been proposed to be involved in pulmonary fibrosis, but its role in this process has not been fully understood. To investigate the role of AGE formation in pulmonary fibrosis, we used a bleomycin (BLM-stimulated rat model treated with aminoguanidine (AG, a crosslink inhibitor of AGE formation. Methods Rats were intratracheally instilled with BLM (5 mg/kg and orally administered with AG (40, 80, 120 mg/kg once daily for two weeks. AGEs level in lung tissue was determined by ELISA and pulmonary fibrosis was evaluated by Ashcroft score and hydroxyproline assay. The expression of heat shock protein 47 (HSP47, a collagen specific molecular chaperone, was measured with RT-PCR and Western blot. Moreover, TGFβ1 and its downstream Smad proteins were analyzed by Western blot. Results AGEs level in rat lungs, as well as lung hydroxyproline content and Ashcroft score, was significantly enhanced by BLM stimulation, which was abrogated by AG treatment. BLM significantly increased the expression of HSP47 mRNA and protein in lung tissues, and AG treatment markedly decreased BLM-induced HSP47 expression in a dose-dependent manner (p Conclusion These findings suggest AGE formation may participate in the process of BLM-induced pulmonary fibrosis, and blockade of AGE formation by AG treatment attenuates BLM-induced pulmonary fibrosis in rats, which is implicated in inhibition of HSP47 expression and TGFβ/Smads signaling.

  2. Increased advanced glycation end product specific fluorescence in repeatedly heated used cooking oil.

    Science.gov (United States)

    Chhabra, Anupriya; Bhatia, Alka; Ram, Anil Kumar; Goel, Sumit

    2017-07-01

    Repeated heating of cooking oils is known to cause their degradation and generation of toxins. Dietary Advanced glycation end products (dAGEs) are formed when the foods are cooked in dry heat at very high temperatures. dAGEs are believed to contribute significantly to total pool of AGEs in body. In this study, cooking oil samples used for frying snacks were collected from 102 shops. AGEs were extracted using Aqueous-TCA-chloroform method. Fluorescent AGE levels were determined using a fluorescence spectrophotometer and compared with AGEs in corresponding fresh oil samples collected from same shops. Palm oil was most commonly (62.5%) used for cooking. Most of the samples were subjected to several rounds of heating (1-6). AGE specific fluorescence (ASF) in used oil (range = 8.5-745.11) samples was found to be significantly higher in 88/102 as compared to the corresponding fresh oil samples. Treatment with inhibitors like lime concentrate and vitamin C decreased ASF (10/14 and 10/11 samples respectively) of the used oils. The results suggest that cooking oil subjected to repeated heating can contribute to increase in fluorescent AGEs in diet. Simple practices like liberal use of common household substances like lime concentrate may help to reduce these in fried food.

  3. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

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    Li, D.X.; Deng, T.Z.; Lv, J.; Ke, J. [Department of Stomatology, Air Force General Hospital PLA, Haidian District, Beijing (China)

    2014-09-19

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction.

  4. Cloning and characterization of the canine receptor for advanced glycation end products.

    Science.gov (United States)

    Murua Escobar, Hugo; Soller, Jan T; Sterenczak, Katharina A; Sperveslage, Jan D; Schlueter, Claudia; Burchardt, Birgit; Eberle, Nina; Fork, Melanie; Nimzyk, Rolf; Winkler, Susanne; Nolte, Ingo; Bullerdiek, Jörn

    2006-03-15

    Metastasis is one of the major problems when dealing with malignant neoplasias. Accordingly, the finding of molecular targets, which can be addressed to reduce tumour metastasising, will have significant impact on the development of new therapeutic approaches. Recently, the receptor for advanced glycation end products (RAGE)-high mobility group B1 (HMGB1) protein complex has been shown to have significant influence on invasiveness, growth and motility of tumour cells, which are essential characteristics required for metastatic behaviour. A set of in vitro and in vivo approaches showed that blocking of this complex resulted in drastic suppression of tumour cell growth. Due to the similarities of human and canine cancer the dog has joined the common rodent animal model for therapeutic and preclinical studies. However, complete characterisation of the protein complex is a precondition to a therapeutic approach based on the blocking of the RAGE-HMGB1 complex to spontaneously occurring tumours in dogs. We recently characterised the canine HMGB1 gene and protein completely. Here we present the complete characterisation of the canine RAGE gene including its 1384 bp mRNA, the 1215 bp protein coding sequence, the 2835 bp genomic structure, chromosomal localisation, gene expression pattern, and its 404 amino acid protein. Furthermore we compared the CDS of six different canine breeds and screened them for single nucleotide polymorphisms.

  5. Receptor for advanced glycation end-products is a marker of type I lung alveolar cells.

    Science.gov (United States)

    Shirasawa, Madoka; Fujiwara, Naoyuki; Hirabayashi, Susumu; Ohno, Hideki; Iida, Junko; Makita, Koshi; Hata, Yutaka

    2004-02-01

    Lung alveolar epithelial cells are comprised of type I (ATI) and type II (ATII) cells. ATI cells are polarized, although they have very flat morphology. The identification of marker proteins for apical and basolateral membranes of ATI cells is important to investigate into the differentiation of ATI cells. In this paper, we characterized receptor for advanced glycation end-products (RAGE) as a marker for ATI cells. RAGE was localized on basolateral membranes of ATI cells in the immunoelectron microscopy and its expression was enhanced in a parallel manner to the differentiation of ATI cells in vivo and in primary cultures of ATII cells. RAGE and T1 alpha, a well-known ATI marker protein, were targeted to basolateral and apical membranes, respectively, when expressed in polarized Madine Darby canine kidney cells. Moreover, RAGE was expressed in ATI cells after T1 alpha in vivo and in ex in vivo organ cultures. In conclusion, RAGE is a marker for basolateral membranes of well-differentiated ATI cells. ATI cells require some signal provided by the in vivo environment to express RAGE.

  6. Methylglyoxal-derived hydroimidazolone-1 evokes inflammatory reactions in endothelial cells via an interaction with receptor for advanced glycation end products.

    Science.gov (United States)

    Ishibashi, Yuji; Matsui, Takanori; Nakamura, Nobutaka; Sotokawauchi, Ami; Higashimoto, Yuichiro; Yamagishi, Sho-Ichi

    2017-09-01

    Glyceraldehyde-derived advanced glycation end products contribute to vascular inflammation in diabetes. However, what advanced glycation end product structure could evoke inflammatory reactions remains unknown. We examined whether and how methylglyoxal-derived hydroimidazolone 1, one of the advanced glycation end products formed from glyceraldehyde, elicits inflammatory reactions in human umbilical vein endothelial cells. Glyceraldehyde-advanced glycation end products-aptamer was prepared using a systemic evolution of ligands by exponential enrichment. The binding affinities of methylglyoxal-derived hydroimidazolone 1 to receptor for advanced glycation end products or advanced glycation end product-aptamer were measured with a quartz crystal microbalance. Intracellular reactive oxygen species generation and THP-1 cell adhesion were evaluated using fluorescent probes. Gene expression was analysed by reverse transcription polymerase chain reaction. Methylglyoxal-derived hydroimidazolone 1 bound to receptor for advanced glycation end products and advanced glycation end product-aptamer with a dissociation constant ( K d ) of 56.7 µM and 1.51 mM, respectively. Methylglyoxal-derived hydroimidazolone 1 at 100 µg/mL significantly increased reactive oxygen species generation in human umbilical vein endothelial cells, which were attenuated by anti-receptor for advanced glycation end products antibody or advanced glycation end product-aptamer. In all, 100 µg/mL methylglyoxal-derived hydroimidazolone 1 significantly increased receptor for advanced glycation end products and intercellular adhesion molecule-1 messenger RNA levels in, and THP-1 cell adhesion to, human umbilical vein endothelial cells, all of which were blocked by anti-receptor for advanced glycation end products antibody. Our present results indicate that methylglyoxal-derived hydroimidazolone 1 evokes inflammatory reactions in human umbilical vein endothelial cells via receptor for advanced glycation

  7. Advanced glycation end-products (AGEs) and associations with cardio-metabolic, lifestyle, and dietary factors in a general population : The NQplus study

    NARCIS (Netherlands)

    Botros, Nadia; Sluik, Diewertje; van Waateringe, Robert P.; de Vries, Jeanne H. M.; Geelen, Anouk; Feskens, Edith J. M.

    Background: Advanced glycation end-products are a heterogeneous group of molecules that are formed during reactions between reducing sugars and proteins. Advanced glycation end-products are thought to play a role in several diseases, including diabetes mellitus and can be measured non-invasively

  8. Attenuation of Glucose-Induced Myoglobin Glycation and the Formation of Advanced Glycation End Products (AGEs by (R-α-Lipoic Acid In Vitro

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    Hardik Ghelani

    2018-02-01

    Full Text Available High-carbohydrate containing diets have become a precursor to glucose-mediated protein glycation which has been linked to an increase in diabetic and cardiovascular complications. The aim of the present study was to evaluate the protective effect of (R-α-lipoic acid (ALA against glucose-induced myoglobin glycation and the formation of advanced glycation end products (AGEs in vitro. Methods: The effect of ALA on myoglobin glycation was determined via the formation of AGEs fluorescence intensity, iron released from the heme moiety of myoglobin and the level of fructosamine. The extent of glycation-induced myoglobin oxidation was measured via the levels of protein carbonyl and thiol. Results: The results showed that the co-incubation of ALA (1, 2 and 4 mM with myoglobin (1 mg/mL and glucose (1 M significantly decreased the levels of fructosamine, which is directly associated with the decrease in the formation of AGEs. Furthermore, ALA significantly reduced the release of free iron from myoglobin which is attributed to the protection of myoglobin from glucose-induced glycation. The results also demonstrated a significant protective effect of ALA on myoglobin from oxidative damage, as seen from the decreased protein carbonyls and increased protein thiols. Conclusion: The anti-glycation properties of ALA suggest that ALA supplementation may be beneficial in the prevention of AGEs-mediated diabetic and cardiovascular complications.

  9. Expression of receptor for advanced glycation end-products (RAGE) in thymus from myasthenia patients.

    Science.gov (United States)

    Bouchikh, M; Zouaidia, F; Benhaddou, E H A; Mahassini, N; Achir, A; El Malki, H O

    2017-06-01

    The receptor for advanced glycation end-products (RAGE) is a membranous immunoglobulin involved in the pathogenesis of numerous autoimmune diseases and tumors. The aim of this study was to investigate the possible involvement of RAGE in the pathogenesis of myasthenia gravis. This prospective study included 41 cases of myasthenia gravis treated at our institution between 2010 and 2015. There were 18 men and 23 women, with an average age of 36.44±14.47 years. The majority of patients (24.4%) were classified as IIb, according to MGFA scoring, and 21 of them required corticosteroid and/or immunosuppressive treatment. Assessment of RAGE in thymus specimens was done by immunohistochemistry using RAGE antibody (C-term). RAGE expression was assessed according to various clinical, paraclinical and pathological parameters. Histopathological studies found 18 thymomas, 17 hyperplasias and six other types of pathology. Expression of RAGE was negative/weak in 19 cases and moderate/strong in 22 cases. It was more important in thymoma type B2 (P<0.001) and when the duration of myasthenia was short (P=0.04), and was not significantly related to either myasthenia clinical severity or preoperative treatment. Our results suggest that the RAGE pathway is involved in myasthenia gravis pathophysiology, especially at disease onset, and in forms with thymomas. Further studies would be indispensable to explore other aspects of this signaling pathway, especially the potential role of different ligands and soluble forms of RAGE. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Receptor for Advanced Glycation End Products (RAGE) Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia

    Science.gov (United States)

    Achouiti, Ahmed; de Vos, Alex F.; van ‘t Veer, Cornelis; Florquin, Sandrine; Tanck, Michael W.; Nawroth, Peter P.; Bierhaus, Angelika; van der Poll, Tom; van Zoelen, Marieke A. D.

    2016-01-01

    Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE) is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed to investigate the role of RAGE in the host response to Klebsiella (K.) pneumoniae pneumonia and intransally inoculated rage gene deficient (RAGE-/-) and normal wild-type (Wt) mice with K. pneumoniae. Klebsiella pneumonia resulted in an increased pulmonary expression of RAGE. Furthermore, the high-affinity RAGE ligand high mobility group box-1 was upregulated during K. pneumoniae pneumonia. RAGE deficiency impaired host defense as reflected by a worsened survival, increased bacterial outgrowth and dissemination in RAGE-/- mice. RAGE-/- neutrophils showed a diminished phagocytosing capacity of live K. pneumoniae in vitro. Relative to Wt mice, RAGE-/- mice demonstrated similar lung inflammation, and slightly elevated—if any—cytokine and chemokine levels and unchanged hepatocellular injury. In addition, RAGE-/- mice displayed an unaltered response to intranasally instilled Klebsiella lipopolysaccharide (LPS) with respect to pulmonary cell recruitment and local release of cytokines and chemokines. These data suggest that (endogenous) RAGE protects against K. pneumoniae pneumonia. Also, they demonstrate that RAGE contributes to an effective antibacterial defense during K. pneumoniae pneumonia, at least partly via its participation in the phagocytic properties of professional granulocytes. Additionally, our results indicate that RAGE is not essential for the induction of a local and systemic inflammatory response to either intact Klebsiella or Klebsiella LPS. PMID:26824892

  11. Receptor for Advanced Glycation End Products (RAGE Serves a Protective Role during Klebsiella pneumoniae - Induced Pneumonia.

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    Ahmed Achouiti

    Full Text Available Klebsiella species is the second most commonly isolated gram-negative organism in sepsis and a frequent causative pathogen in pneumonia. The receptor for advanced glycation end products (RAGE is expressed on different cell types and plays a key role in diverse inflammatory responses. We here aimed to investigate the role of RAGE in the host response to Klebsiella (K. pneumoniae pneumonia and intransally inoculated rage gene deficient (RAGE-/- and normal wild-type (Wt mice with K. pneumoniae. Klebsiella pneumonia resulted in an increased pulmonary expression of RAGE. Furthermore, the high-affinity RAGE ligand high mobility group box-1 was upregulated during K. pneumoniae pneumonia. RAGE deficiency impaired host defense as reflected by a worsened survival, increased bacterial outgrowth and dissemination in RAGE-/- mice. RAGE-/- neutrophils showed a diminished phagocytosing capacity of live K. pneumoniae in vitro. Relative to Wt mice, RAGE-/- mice demonstrated similar lung inflammation, and slightly elevated-if any-cytokine and chemokine levels and unchanged hepatocellular injury. In addition, RAGE-/- mice displayed an unaltered response to intranasally instilled Klebsiella lipopolysaccharide (LPS with respect to pulmonary cell recruitment and local release of cytokines and chemokines. These data suggest that (endogenous RAGE protects against K. pneumoniae pneumonia. Also, they demonstrate that RAGE contributes to an effective antibacterial defense during K. pneumoniae pneumonia, at least partly via its participation in the phagocytic properties of professional granulocytes. Additionally, our results indicate that RAGE is not essential for the induction of a local and systemic inflammatory response to either intact Klebsiella or Klebsiella LPS.

  12. Role of advanced glycation end products (AGEs) and oxidative stress in diabetic retinopathy.

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    Yamagishi, Sho-ichi; Ueda, Seiji; Matsui, Takanori; Nakamura, Kazuo; Okuda, Seiya

    2008-01-01

    Diabetic retinopathy is a common and potentially devastating microvascular complication in diabetes and is a leading cause of acquired blindness among the people of occupational age. However, current therapeutic options for the treatment of sight-threatening proliferative diabetic retinopathy such as photocoagulation and vitrectomy are limited by considerable side effects and far from satisfactory. Therefore, to develop novel therapeutic strategies that specifically target diabetic retinopathy is actually desired for most of the patients with diabetes. Chronic hyperglycemia is a major initiator of diabetic retinopathy. However, recent clinical study has substantiated the concept of 'hyperglycemic memory' in the pathogenesis of diabetic retinopathy. Indeed, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that the reduction in the risk of progressive retinopathy resulting from intensive therapy in patients with type 1 diabetes persisted for at least several years after the DCCT trial, despite increasing hyperglycemia. These findings suggest a long-term beneficial influence of early metabolic control on clinical outcomes in type 1 diabetic patients. Among various biochemical pathways implicated in the pathogenesis of diabetic retinopathy, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory 'hyperglycemic memory'. Further, there is a growing body of evidence that AGEs-RAGE (receptor for AGEs) interaction-mediated oxidative stress generation plays an important role in diabetic retinopathy. This article summarizes the role of AGEs and oxidative stress in the development and progression of diabetic retinopathy and the therapeutic interventions that could prevent this devastating disorder. We also discuss here the pathological crosstalk between the AGEs-RAGE and the renin-angiotensin system in

  13. N -Glycans on the receptor for advanced glycation end products influence amphoterin binding and neurite outgrowth.

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    Srikrishna, Geetha; Huttunen, Henri J; Johansson, Lena; Weigle, Bernd; Yamaguchi, Yu; Rauvala, Heikki; Freeze, Hudson H

    2002-03-01

    In this study we show that embryonic neurite growth-promoting protein amphoterin binds to carboxylated N -glycans previously identified on mammalian endothelial cells. Since amphoterin is a ligand for the receptor for advanced glycation end products (RAGE), and the ligand-binding V-domain of the receptor contains two potential N -glycosylation sites, we hypothesized that N -glycans on RAGE may mediate its interactions with amphoterin. In support of this, anti-carboxylate antibody mAbGB3.1 immunoprecipitates bovine RAGE, and PNGase F treatment reduces its molecular mass by 4.5 kDa, suggesting that the native receptor is a glycoprotein. The binding potential of amphoterin to RAGE decreases significantly in presence of soluble carboxylated glycans or when the receptor is deglycosylated. Oligosaccharide analysis shows that RAGE contains complex type anionic N -glycans with non-sialic acid carboxylate groups, but not the HNK-1 (3-sulfoglucuronyl beta1-3 galactoside) epitope. Consistent with the functional localization of RAGE and amphoterin at the leading edges of developing neurons, mAbGB3.1 stains axons and growth cones of mouse embryonic cortical neurons, and inhibits neurite outgrowth on amphoterin matrix. The carboxylated glycans themselves promote neurite outgrowth in embryonic neurons and RAGE-transfected neuroblastoma cells. This outgrowth requires full-length, signalling-competent RAGE, as cells expressing cytoplasmic domain-deleted RAGE are unresponsive. These results indicate that carboxylated N -glycans on RAGE play an important functional role in amphoterin-RAGE-mediated signalling.

  14. Hydrogen Sulfide Prevents Advanced Glycation End-Products Induced Activation of the Epithelial Sodium Channel

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    Qiushi Wang

    2015-01-01

    Full Text Available Advanced glycation end-products (AGEs are complex and heterogeneous compounds implicated in diabetes. Sodium reabsorption through the epithelial sodium channel (ENaC at the distal nephron plays an important role in diabetic hypertension. Here, we report that H2S antagonizes AGEs-induced ENaC activation in A6 cells. ENaC open probability (PO in A6 cells was significantly increased by exogenous AGEs and that this AGEs-induced ENaC activity was abolished by NaHS (a donor of H2S and TEMPOL. Incubating A6 cells with the catalase inhibitor 3-aminotriazole (3-AT mimicked the effects of AGEs on ENaC activity, but did not induce any additive effect. We found that the expression levels of catalase were significantly reduced by AGEs and both AGEs and 3-AT facilitated ROS uptake in A6 cells, which were significantly inhibited by NaHS. The specific PTEN and PI3K inhibitors, BPV(pic  and LY294002, influence ENaC activity in AGEs-pretreated A6 cells. Moreover, after removal of AGEs from AGEs-pretreated A6 cells for 72 hours, ENaC PO remained at a high level, suggesting that an AGEs-related “metabolic memory” may be involved in sodium homeostasis. Our data, for the first time, show that H2S prevents AGEs-induced ENaC activation by targeting the ROS/PI3K/PTEN pathway.

  15. Advanced Glycation End-Products affect transcription factors regulating insulin gene expression

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    Puddu, A.; Storace, D.; Odetti, P.; Viviani, G.L.

    2010-01-01

    Advanced Glycation End-Products (AGEs) are generated by the covalent interaction of reducing sugars with proteins, lipids or nucleic acids. AGEs are implicated in diabetic complications and pancreatic β-cell dysfunction. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T15 to high concentrations of AGEs leads to a significant decrease of insulin secretion and content. Insulin gene transcription is positively regulated by the beta cell specific transcription factor PDX-1 (Pancreatic and Duodenal Homeobox-1). On the contrary, the forkhead transcription factor FoxO1 inhibits PDX-1 gene transcription. Activity of FoxO1 is regulated by post-translational modifications: phosphorylation deactivates FoxO1, and acetylation prevents FoxO1 ubiquitination. In this work we investigated whether AGEs affect expression and subcellular localization of PDX-1 and FoxO1. HIT-T15 cells were cultured for 5 days in presence of AGEs. Cells were then lysed and processed for subcellular fractionation. We determined intracellular insulin content, then we assessed the expression and subcellular localization of PDX-1, FoxO1, phosphoFoxO1 and acetylFoxO1. As expected intracellular insulin content was lower in HIT-T15 cells cultured with AGEs. The results showed that AGEs decreased expression and nuclear localization of PDX-1, reduced phosphorylation of FoxO1, and increased expression and acetylation of FoxO1. These results suggest that AGEs decrease insulin content unbalancing transcription factors regulating insulin gene expression.

  16. Advanced glycation end products impair the migration, adhesion and secretion potentials of late endothelial progenitor cells

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    Li Hong

    2012-04-01

    Full Text Available Abstract Background Endothelial progenitor cells (EPCs, especially late EPCs, play a critical role in endothelial maintenance and repair, and postnatal vasculogenesis. Advanced glycation end products (AGEs have been shown to impair EPC functions, such as proliferation, migration and adhesion. However, their role in the regulation of the production of vasoactive substances in late EPCs is less well defined. Methods Passages of 3~5 EPCs, namely late EPCs, were cultured with different concentrations (0~500 μg/ml of AGEs, and the apoptosis, adhesion and migration were subsequently determined. The release of vasoactive substances, such as stromal cell-derived factor-1 (SDF-1, nitric oxide (NO, prostaglandin I2 (PGI2, plasminogen activator inhibitor-1 (PAI-1, tissue plasminogen activator (tPA, and in addition the activity of superoxide dismutase (SOD, were evaluated by ELISA. At the same time, the gene and protein expressions of CXCR4 were assayed by real-time RT-PCR and western-blot. Results AGEs promoted late EPC apoptosis. Moreover, AGEs impaired late EPC migration and adhesion in a concentration-dependent manner. Accordingly, the production of SDF-1 was decreased by AGEs. Although the CXCR4 expressions of late EPCs were up-regulated for AGE concentrations of 50, 100 or 200 μg/ml, a marked decrease was observed for the higher concentration of 500 μg/ml. Furthermore, co-culturing with AGEs decreased the levels of NO, t-PA, PGI2, and the activity of SOD but up-regulated the production of PAI-1. Conclusion Our data provide evidence that AGEs play an important role in impairing late EPC functions, which could contribute to the development of vascular diseases in diabetes.

  17. Association between Advanced Glycation End Products and Impaired Fasting Glucose: Results from the SALIA Study.

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    Tom Teichert

    Full Text Available Advanced glycation end products (AGEs may contribute to the development of type 2 diabetes and related complications, whereas their role in the early deterioration of glycaemia is unknown. While previous studies used antibody-based methods to quantify AGEs, data from tandem mass spectrometry coupled liquid chromatography (LC-MS/MS-based measurements are limited to patients with known diabetes. Here, we used the LC-MS/MS method to test the hypothesis that plasma AGE levels are higher in individuals with impaired fasting glucose (IFG than in those with normal fasting glucose (NFG. Secondary aims were to assess correlations of plasma AGEs with quantitative markers of glucose metabolism and biomarkers of subclinical inflammation. This study included on 60 women with NFG or IFG (n = 30 each, mean age 74 years from the German SALIA cohort. Plasma levels of free metabolites (3-deoxyfructose, 3-deoxypentosone, 3-deoxypentulose, two hydroimidazolones, oxidised adducts (carboxymethyllysine, carboxyethyllysine, methionine sulfoxide and Nε-fructosyllysine were measured using LC-MS/MS. Plasma concentrations of all tested AGEs did not differ between the NFG and IFG groups (all p>0.05. Associations between plasma levels of AGEs and fasting glucose, insulin and HOMA-IR as a measure of insulin resistance were weak (r between -0.2 and 0.2, all p>0.05. The association between 3-deoxyglucosone-derived hydroimidazolone with several proinflammatory biomarkers disappeared upon adjustment for multiple testing. In conclusion, plasma AGEs assessed by LC-MS/MS were neither increased in IFG nor associated with parameters of glucose metabolism and subclinical inflammation in our study. Thus, these data argue against strong effects of AGEs in the early stages of deterioration of glucose metabolism.

  18. Sulforaphane reduces advanced glycation end products (AGEs)-induced inflammation in endothelial cells and rat aorta.

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    Matsui, T; Nakamura, N; Ojima, A; Nishino, Y; Yamagishi, S-I

    2016-09-01

    Advanced glycation end products (AGEs)-receptor RAGE interaction evokes oxidative stress and inflammatory reactions, thereby being involved in endothelial cell (EC) damage in diabetes. Sulforaphane is generated from glucoraphanin, a naturally occurring isothiocyanate found in widely consumed cruciferous vegetables, by myrosinase. Sulforaphane has been reported to protect against oxidative stress-mediated cell and tissue injury. However, effects of sulforaphane on AGEs-induced vascular damage remain unclear. In this study, we investigated whether and how sulforaphane could inhibit inflammation in AGEs-exposed human umbilical vein ECs (HUVECs) and AGEs-injected rat aorta. Sulforaphane treatment for 4 or 24 h dose-dependently inhibited the AGEs-induced increase in RAGE, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecular-1 (VCAM-1) gene expression in HUVECs. AGEs significantly stimulated MCP-1 production by, and THP-1 cell adhesion to, HUVECs, both of which were prevented by 1.6 μM sulforaphane. Sulforaphane significantly suppressed oxidative stress generation and NADPH oxidase activation evoked by AGEs in HUVECs. Furthermore, aortic RAGE, ICAM-1 and VCAM-1 expression in AGEs-injected rats were increased, which were suppressed by simultaneous infusion of sulforaphane. The present study demonstrated for the first time that sulforaphane could inhibit inflammation in AGEs-exposed HUVECs and AGEs-infused rat aorta partly by suppressing RAGE expression through its anti-oxidative properties. Inhibition of the AGEs-RAGE axis by sulforaphane might be a novel therapeutic target for vascular injury in diabetes. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  19. Methylglyoxal, advanced glycation end products and autism: is there a connection?

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    Maher, P

    2012-04-01

    Autism is a complex and heterogeneous neurodevelopmental disorder of unknown etiology but very likely resulting from both genetic and environmental factors. Recent estimates suggest that it affects 1 in 100-150 individuals in the US. Oxidative stress, inflammation and mitochondrial dysfunction have all been suggested to play key roles in autism and may be linked via alterations in cellular redox homeostasis. The glutathione/glutathione disulfide (GSH/GSSG) redox pair forms the major redox couple in cells and as such plays a critical role in regulating redox-dependent cellular functions. A number of studies have shown that variations in genes involved in GSH metabolism are associated with autism. GSH also modulates the activity of glyoxalase 1 (Glo-1), the rate-limiting enzyme for the removal of reactive dicarbonyls such as methylglyoxal (MG). MG is the major precursor for the formation of advanced glycation end products (AGEs). Both MG and AGEs can induce oxidative stress, inflammation and mitochondrial dysfunction and are implicated in diabetic complications and multiple, age-related neurological diseases. Dietary consumption of AGEs and MG correlates with food intake which has increased 20-30% over the past 20 years. Both MG and AGEs are orally absorbed, leading to increased levels in the blood. Furthermore, in humans, increased MG and AGE levels in maternal blood correlate with increased MG and AGE levels in newborn blood, potentially exposing infants to high oxidative stress and inflammation. It is hypothesized that diet derived MG and AGEs in combination with inborn genetic vulnerabilities that affect the cellular redox status are major contributors to the development of autism and provide a causal link between oxidative stress, inflammation and mitochondrial dysfunction. If future research supports this hypothesis, then by reducing the exposure to these diet-derived factors, it might be possible to decrease the prevalence of at least a subset of autism cases

  20. Impact of Androgen and Dietary Advanced Glycation End Products on Female Rat Liver

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    Eleni Palioura

    2015-09-01

    Full Text Available Background/Aims: Advanced glycation end products (AGEs have been related to a wide range of liver disorders including hyperandrogenic states such as the Polycystic Ovary Syndrome (PCOS. The aim of the present study is to evaluate the potential impact of dietary glycotoxins exposure and androgen excess on hepatic histology and biochemistry in an androgenized female rat model. Methods: The study population consisted of 80 female Wistar rats, divided in 3 groups, a group of prepubertal (Group A, n=30 and adult rats (Group B, n=20 that were androgenized via subcutaneous implantation of dihydrotestosterone-containing pellets as well as a group of adult non-androgenized rodents (Group C, n=30. All groups were randomly assigned either to a high-AGE or low-AGE diet for 3 months. Results: Rats fed with a high-AGE diet exhibited significantly elevated levels of gamma-glutamyl transferase (γGT (p≤0.0002 and indices of AGE immunostaining in liver tissue (pper se constitutes an aggravating factor as demonstrated by the elevated γGT levels in adult androgenized animals compared to non-androgenized, independent of diet content (p=0.0002 and by the elevated AST and alanine aminotransferase (ALT levels in low-AGE subgroups (adult androgenized vs. non-androgenized, p=0.0002 followed by increased immunohistochemical AGE deposition in hepatocytes of the latter categories (p=0.0007. Conclusion: The present study suggests that androgens and glycotoxins may contribute synergistically to distort hepatic physiology and function as observed in hyperandrogenic conditions.

  1. Skin autofluorescence (a marker for advanced glycation end products) and erectile dysfunction in diabetes.

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    Kouidrat, Youssef; Zaitouni, Ahmad; Amad, Ali; Diouf, Momar; Desailloud, Rachel; Loas, Gwenole; Lalau, Jean-Daniel

    2017-01-01

    Although diabetes-related erectile dysfunction (ED) has many etiological factors, little is known about the putative pathophysiological role of advanced glycation end products (AGEs). Skin autofluorescence is a noninvasive marker of AGEs. Recent studies have evidenced a relationship between skin autofluorescence and several complications of diabetes. We hypothesized that AGEs (assessed by skin autofluorescence) are associated with ED in diabetes patients. Between March 2014 and April 2015, 42 patients with type 1 diabetes (T1D) and 44 patients with type 2 diabetes (T2D) were consecutively enrolled in a descriptive, cross-sectional study and compared to 54 healthy controls. ED was evaluated via the 5-item version of the International Index of Erectile Function (IIEF-5). Skin autofluorescence was measured on the volar aspect of the arm with an AGE-Reader. Patients with diabetes had a mean±standard deviation age of 50±15 and a mean duration of diabetes of 16±12years. Skin autofluorescence was strongly and significantly correlated with the IIEF-5 score in the T1D subgroup (r=-0.52; P=0.004), the T2D subgroup (r=-0.32; Pmultivariate analyses that controlled for potentially confounding clinical and biochemical factors, only skin autofluorescence was still significantly correlated with the IIEF-5 score (Panalysis revealed that a skin autofluorescence value ≥3.2AU determined severe ED with a sensitivity of 60% and a specificity of 87% in diabetic patients. Skin autofluorescence is significantly associated with ED in diabetes, independently of classical confounding factors. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Targeting receptor for advanced glycation end products (RAGE) expression induces apoptosis and inhibits prostate tumor growth

    International Nuclear Information System (INIS)

    Elangovan, Indira; Thirugnanam, Sivasakthivel; Chen, Aoshuang; Zheng, Guoxing; Bosland, Maarten C.; Kajdacsy-Balla, André; Gnanasekar, Munirathinam

    2012-01-01

    Highlights: ► Targeting RAGE by RNAi induces apoptosis in prostate cancer cells. ► Silencing RAGE expression abrogates rHMGB1 mediated cell proliferation. ► Down regulation of RAGE by RNAi inhibits PSA secretion of prostate cancer cells. ► Knock down of RAGE abrogates prostate tumor growth in vivo. ► Disruption of RAGE expression in prostate tumor activates death receptors. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a key role in the progression of prostate cancer. However, the therapeutic potential of targeting RAGE expression in prostate cancer is not yet evaluated. Therefore in this study, we have investigated the effects of silencing the expression of RAGE by RNAi approach both in vitro and in vivo. The results of this study showed that down regulation of RAGE expression by RNAi inhibited the cell proliferation of androgen-dependent (LNCaP) and androgen-independent (DU-145) prostate cancer cells. Furthermore, targeting RAGE expression resulted in apoptotic elimination of these prostate cancer cells by activation of caspase-8 and caspase-3 death signaling. Of note, the levels of prostate specific antigen (PSA) were also reduced in LNCaP cells transfected with RAGE RNAi constructs. Importantly, the RAGE RNAi constructs when administered in nude mice bearing prostate tumors, inhibited the tumor growth by targeting the expression of RAGE, and its physiological ligand, HMGB1 and by up regulating death receptors DR4 and DR5 expression. Collectively, the results of this study for the first time show that targeting RAGE by RNAi may be a promising alternative therapeutic strategy for treating prostate cancer.

  3. Advanced glycation end products promote proliferation and suppress autophagy via reduction of Cathepsin D in rat vascular smooth muscle cells.

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    Ma, Mingfeng; Guo, Xiaofan; Chang, Ye; Li, Chao; Meng, Xin; Li, Si; Du, Zhen-Xian; Wang, Hua-Qin; Sun, Yingxian

    2015-05-01

    Autophagy is closely involved in vascular smooth muscle cell (VSMC) function, but little is known about the association between advanced glycation end products (AGEs) and autophagy and its role in AGEs-induced proliferation and migration of VSMCs. The current study investigated the effects of AGEs on the phenotypic modulation and autophagy of VSMCs, as well as the potential underlying mechanisms. Primary rat VSMCs were treated with bovine serum albumin or AGEs. Cell proliferation was detected by MTT assay, real-time cell analyzer and EdU incorporation. Cell cycle was analyzed by Hoechst staining and flow cytometry. The migration of VSMCs was detected by wound-healing assay and transwell migration assay. LC3 transition and p62 accumulation were detected using Western blotting. Acidic vacuoles were measured using AO and MDC staining. Cathepsin D (CatD) was transduced to VSMCs via lentiviral vectors. AGEs enhanced proliferation and migration of primary rat VSMC in a time-dependent manner. AGEs significantly increased LC3-II transition and p62 expression, as well as accumulation of acidic vacuole, which was not further increased by bafilomycin A1. AGEs decreased CatD expression in a time-dependent pattern, and overexpression of CatD prohibited autophagy attenuation mediated by AGEs. CatD overexpression suppressed AGEs-induced proliferation of VSMCs. Nevertheless, CatD exhibited no effects on AGEs-induced migration of VSMCs. AGEs promote proliferation of VSMCs and suppress autophagy, at least in part via CatD reduction.

  4. Characterizing harmful advanced glycation end-products (AGEs) and ribosylated aggregates of yellow mustard seed phytocystatin: Effects of different monosaccharides

    Science.gov (United States)

    Ahmed, Azaj; Shamsi, Anas; Bano, Bilqees

    2017-01-01

    Advanced glycation end products (AGEs) are at the core of variety of diseases ranging from diabetes to renal failure and hence gaining wide consideration. This study was aimed at characterizing the AGEs of phytocystatin isolated from mustard seeds (YMP) when incubated with different monosaccharides (glucose, ribose and mannose) using fluorescence, ultraviolet, circular dichroism (CD) spectroscopy and microscopy. Ribose was found to be the most potent glycating agent as evident by AGEs specific fluorescence and absorbance. YMP exists as a molten globule like structure on day 24 as depicted by high ANS fluorescence and altered intrinsic fluorescence. Glycated YMP as AGEs and ribose induced aggregates were observed at day 28 and 32 respectively. In our study we have also examined the anti-aggregative potential of polyphenol, resveratrol. Our results suggested the anti-aggregative behavior of resveratrol as it prevented the in vitro aggregation of YMP, although further studies are required to decode the mechanism by which resveratrol prevents the aggregation.

  5. Effect of cranberry (Vaccinium macrocarpon) oligosaccharides on the formation of advanced glycation end-products.

    Science.gov (United States)

    Sun, Jiadong; Liu, Weixi; Ma, Hang; Marais, Jannie P J; Khoo, Christina; Dain, Joel A; Rowley, David C; Seeram, Navindra P

    2016-06-16

    BACKGROUND: The formation and accumulation of advanced glycation end-products (AGEs) are implicated in several chronic human illnesses including type-2 diabetes, renal failure, and neurodegenerative diseases. The cranberry ( Vaccinium macrocarpon ) fruit has been previously reported to show anti-AGEs effects, attributed primarily to its phenolic constituents. However, there is lack of similar data on the non-phenolic constituents found in the cranberry fruit, in particular, its carbohydrate constituents. Herein, a chemically characterized oligosaccharide-enriched fraction purified from the cranberry fruit was evaluated for its potential anti-AGEs and free radical scavenging effects. OBJECTIVE: The aim of this study was to evaluate the in vitro anti-AGEs and free radical scavenging effects of a chemically characterized oligosaccharide-enriched fraction purified from the North American cranberry ( Vaccinium macrocarpon ) fruit. METHOD: The cranberry oligosaccharide-enriched fraction was purified from cranberry hull powder and characterized based on spectroscopic and spectrometric (NMR, MALDI-TOF-MS, and HPAEC-PAD) data. The oligosaccharide-enriched fraction was evaluated for its anti-AGEs and free radical scavenging effects by the bovine serum albumin-fructose, and DPPH assays, respectively. RESULTS: Fractionation of cranberry hull material yielded an oligosaccharide-enriched fraction named Cranf1b-CL. The 1 H NMR and MALDI-TOF-MS revealed that Cranf1b-CL consists of oligosaccharides ranging primarily from 6-mers to 9-mers. The monosaccharide composition of Cranf1b-CL was arabinose (25%), galactose (5%), glucose (47%) and xylose (23%). In the bovine serum albumin-fructose assay, Cranf1b-CL inhibited AGEs formation in a concentration-dependent manner with comparable activity to the synthetic antiglycating agent, aminoguanidine, used as the positive control (57 vs. 75%; both at 500μg/mL). In the DPPH free radical scavenging assay, Cranf1b-CL showed superior activity

  6. Evaluation of advanced glycation end-products in diabetic and inherited canine cataracts.

    Science.gov (United States)

    Bras, I Dineli; Colitz, Carmen M H; Kusewitt, Donna F; Chandler, Heather; Lu, Ping; Gemensky-Metzler, Anne J; Wilkie, David A

    2007-02-01

    The receptor for advanced glycation end-products (RAGE) increases in the human cataract and should correlate with increased DNA damage and proliferation of lens epithelial cells (LECs). The purpose of this study was to measure and immunolocalize RAGE in normal and cataractous canine LECs, and to determine whether there was a correlation between RAGE and DNA damage (gadd45), cell-cycle regulation (p21), and LEC proliferation (proliferating cell nuclear antigen, PCNA). Thirty-two anterior lens capsules from 22 dogs that underwent cataract surgery and 10 lenses from dogs with normal eyes were evaluated. Eleven of the cataractous lenses were from diabetic patients (n=16), and eleven were from patients with inherited cataracts (n=16). Standard immunohistochemical staining was performed using antibodies against RAGE, gadd45, p21, PCNA, alpha-smooth muscle actin, and TGF-beta. Immunostaining intensity for each antibody was given a score of 0-4+. Standard Western blot analysis on normal and cataractous lens capsules was performed using the same antibodies as in the immunohistochemical staining. Comparisons were also made based on age and sex. Real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed for RAGE. There was an increase in RAGE expression with age in normal LECs, but no significant difference was seen when normal adult LECs were compared to cataractous LECs. The stage of the cataract and the presence of LIU were not associated with a significant increase in RAGE expression. There was no age-dependent difference in the normal lenses for gadd45, p21, or PCNA. Significant up-regulation of p21 (P RAGE and PCNA expression did not increase with cataractogenesis, possibly due to overexpression associated with normal aging and constant exposure to oxidative stress from sunlight-related ultraviolet irradiation, respectively. However, p21 and PCNA increased in diabetic cataractogenesis suggesting cell cycle and proliferation dysregulation. This may

  7. Cathepsin D contributes to the accumulation of advanced glycation end products during photoaging.

    Science.gov (United States)

    Xu, Xinya; Zheng, Yue; Huang, Yunfen; Chen, Jian; Gong, Zijian; Li, Yuying; Lu, Chun; Lai, Wei; Xu, Qingfang

    2018-02-19

    The deposition of advanced glycation end products (AGEs) is accelerated in photoaged skin, but the underlying mechanisms remain elusive. Intracellular degradation has been recently considered to play an important role in AGEs removal. Although lysosomal cathepsin D (CatD), B (CatB), L(CatL) and proteasomes are found to degrade internalized AGEs, it remains unknown which protease degrades internalized AGEs in human dermal fibroblasts (HDFs), and whether a decrease in intracellular degradation contributes to enhanced AGEs deposition in photoaged skin. This study aims to investigate the specific proteases that contribute to intracellular AGEs degradation in HDFs and regulate AGEs accumulation in photoaged skin. Repetitive UVA irradiation was used to induce primary HDF photoaging in vitro. Uptake and degradation of AGE-BSA were verified and compared between photoaged and non-photoaged fibroblasts with flow cytometry, ELISA and confocal microscopy. Proteasomal and lysosomal activity, expression of CatD, CatB and CatL were also investigated between photoaged and non-photoaged fibroblasts. Further, the effect of protease inhibitors and CatD overexpression via lentiviral transduction on AGE-BSA degradation was analyzed. Finally, the correlation between CatD expression and AGEs accumulation in sun-exposed and sun-protected skin of people from different age was studied with immunohistochemistry. Fibroblasts underwent photoaging in vitro after repetitive UVA irradiation. AGE-BSA was taken up by both photoaged and non-photoaged fibroblasts, but its degradation was significantly decreased in photoaged cells than that of non-photoaged cells. Although the activity of proteasome, CatB, Cat L and Cat D was significantly reduced in photoaged fibroblasts compared to that of non-photoaged cells, and the expression of CatB, CatL and CatD was profoundly attenuated in photoaged fibroblasts, inhibiting proteasome, CatB and CatL did not affect AGE-BSA degradation in HDFs. In contrast

  8. Lateral diffusion and signaling of receptor for advanced glycation end-products (RAGE): a receptor involved in chronic inflammation.

    Science.gov (United States)

    Syed, Aleem; Zhu, Qiaochu; Smith, Emily A

    2018-01-01

    Membrane diffusion is one of the key mechanisms in the cellular function of receptors. The signaling of receptors for advanced glycation end-products (RAGE) has been extensively studied in the context of several pathological conditions, however, very little is known about RAGE diffusion. To fill this gap, RAGE lateral diffusion is probed in native, cholesterol-depleted, and cytoskeleton-altered cellular conditions. In native GM07373 cellular conditions, RAGE has a 90% mobile fraction and an average diffusion coefficient of 0.3 μm 2 /s. When depolymerization of the actin cytoskeleton is inhibited with the small molecule jasplakinolide (Jsp), the RAGE mobile fraction and diffusion coefficient decrease by 22 and 37%, respectively. In contrast, depolymerizing the filamentous actin cytoskeleton using the small molecule cytochalasin D (CD) does not alter the RAGE diffusion properties. There is a 70 and 50% decrease in phosphorylation of extracellular signal-regulated kinase (p-ERK) when the actin cytoskeleton is disrupted by CD or Jsp, respectively, in RAGE-expressing GM07373 cells. Disrupting the actin cytoskeleton in GM07373 cells that do not express detectable amounts of RAGE results in no change in p-ERK. Cholesterol depletion results in no statistically significant change in the diffusion properties of RAGE or p-ERK. This work presents a strong link between the actin cytoskeleton and RAGE diffusion and downstream signaling, and serves to further our understanding of the factors influencing RAGE lateral diffusion.

  9. 糖基化终末产物及其受体在糖尿病大鼠胃组织中的分布 (Distribution of advanced glycation end products and their receptor in the stomach of diabetic rats)

    DEFF Research Database (Denmark)

    Tian, Jia Xing; Zhao, Jingbo; Li, Min

    2015-01-01

    AIM: To observe the distribution of advanced glycation end products (AGEs) and their receptor (RAGE) in the stomach of diabetic rats. METHODS: Diabetes mellitus (DM) and control (CON) rats were reared for eight weeks. Fasting plasma glucose (FPG), glycated serum protein (GSP) and gastric layer...... end products; Receptor for advanced glycation end products...

  10. The effect of an advanced glycation end-product crosslink breaker and exercise training on vascular function in older individuals: a randomized factorial design trial.

    NARCIS (Netherlands)

    Oudegeest-Sander, M.H.; Olde Rikkert, M.G.M.; Smits, P.; Thijssen, D.H.J.; Dijk, A.P.J. van; Levine, B.D.; Hopman, M.T.E.

    2013-01-01

    Aging leads to accumulation of irreversible advanced glycation end-products (AGEs), contributing to vascular stiffening and endothelial dysfunction. When combined with the AGE-crosslink breaker Alagebrium, exercise training reverses cardiovascular aging in experimental animals. This study is the

  11. Role of the advanced glycation end products receptor in Crohn’s disease inflammation

    Science.gov (United States)

    Ciccocioppo, Rachele; Vanoli, Alessandro; Klersy, Catherine; Imbesi, Venerina; Boccaccio, Vincenzo; Manca, Rachele; Betti, Elena; Cangemi, Giuseppina Cristina; Strada, Elena; Besio, Roberta; Rossi, Antonio; Falcone, Colomba; Ardizzone, Sandro; Fociani, Paolo; Danelli, Piergiorgio; Corazza, Gino Roberto

    2013-01-01

    AIM: To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products (RAGE) in delayed apoptosis and tumor necrosis factor (TNF)-α production in Crohn’s disease (CD). METHODS: Surgical and endoscopic specimens from both inflamed and non-inflamed areas of the ileum and/or colon were collected from 20 and 14 adult CD patients, respectively, and used for the assessment of RAGE expression by means of immunohistochemistry and western blotting analysis. Normal tissues from 21 control subjects were used for comparison. The same polyclonal anti-human RAGE antibody (R and D System) was used in all experimental conditions. RAGE staining was quantized by a score including both the amount of positive cells and intensity of immunoreactivity; cellular pattern was also described. The effects of RAGE blocking on apoptotic rate and TNF-α production were investigated on immune cells freshly isolated from CD mucosa and incubated both with and without the muramyl dipeptide used as antigenic stimulus. Statistical analysis was performed via the test for trend, with regression models to account for intra-patient correlations. A 2-sided P < 0.05 was considered significant. RESULTS: In inflamed areas, RAGE expression in both the epithelial and lamina propria compartments was higher than control tissues (P = 0.001 and 0.021, respectively), and a cluster of positive cells were usually found in proximity of ulcerative lesions. Similar results were obtained in the lamina propria compartment of non-inflamed areas (P = 0.025). The pattern of staining was membranous and granular cytosolic at the epithelial level, while in the lamina propria it was diffuse cytosolic. When evaluating the amount of protein expression by immunoblotting, a significant increase of both surface area and band intensity (P < 0.0001 for both) was observed in CD inflamed areas compared to control tissue, while in non-inflamed areas a significant increase was

  12. Role of the advanced glycation end products receptor in Crohn's disease inflammation.

    Science.gov (United States)

    Ciccocioppo, Rachele; Vanoli, Alessandro; Klersy, Catherine; Imbesi, Venerina; Boccaccio, Vincenzo; Manca, Rachele; Betti, Elena; Cangemi, Giuseppina Cristina; Strada, Elena; Besio, Roberta; Rossi, Antonio; Falcone, Colomba; Ardizzone, Sandro; Fociani, Paolo; Danelli, Piergiorgio; Corazza, Gino Roberto

    2013-12-07

    To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products (RAGE) in delayed apoptosis and tumor necrosis factor (TNF)-α production in Crohn's disease (CD). Surgical and endoscopic specimens from both inflamed and non-inflamed areas of the ileum and/or colon were collected from 20 and 14 adult CD patients, respectively, and used for the assessment of RAGE expression by means of immunohistochemistry and western blotting analysis. Normal tissues from 21 control subjects were used for comparison. The same polyclonal anti-human RAGE antibody (R and D System) was used in all experimental conditions. RAGE staining was quantized by a score including both the amount of positive cells and intensity of immunoreactivity; cellular pattern was also described. The effects of RAGE blocking on apoptotic rate and TNF-α production were investigated on immune cells freshly isolated from CD mucosa and incubated both with and without the muramyl dipeptide used as antigenic stimulus. Statistical analysis was performed via the test for trend, with regression models to account for intra-patient correlations. A 2-sided P < 0.05 was considered significant. In inflamed areas, RAGE expression in both the epithelial and lamina propria compartments was higher than control tissues (P = 0.001 and 0.021, respectively), and a cluster of positive cells were usually found in proximity of ulcerative lesions. Similar results were obtained in the lamina propria compartment of non-inflamed areas (P = 0.025). The pattern of staining was membranous and granular cytosolic at the epithelial level, while in the lamina propria it was diffuse cytosolic. When evaluating the amount of protein expression by immunoblotting, a significant increase of both surface area and band intensity (P < 0.0001 for both) was observed in CD inflamed areas compared to control tissue, while in non-inflamed areas a significant increase was found only for band

  13. The Effect of Chang Run Tong on Biomechanical Colon Remodeling in STZ-Induced Type I Diabetic Rats - Is It Related to Advanced Glycation End Product Formation?

    DEFF Research Database (Denmark)

    Zhao, Jingbo; Gregersen, Hans

    2015-01-01

    injection 40mg/kg of STZ. CRT was poured directly into the stomach by gastric lavage once daily. The experimental period was 60 days. Blood glucose level, serum insulin level and body weight were measured. At the end of the experiment, morphometric data such as the circumferential length, the wall thickness...... the length, diameter and pressure data and from the zero-stress state geometry. The expression of advanced glycation end products (AGE) and receptor of AGE (RAGE) were detected in different layers by using immunohistochemistry method and quantitatively analyzed by using imaging analysis software. Linear...

  14. Skin Autofluorescence Relates to Soluble Receptor for Advanced Glycation End-Products and Albuminuria in Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    J. Škrha

    2013-01-01

    Full Text Available The aim of this study was to compare skin autofluorescence caused by advanced glycation end-products (AGEs with biochemical markers of endothelial dysfunction and soluble receptor for AGEs (sRAGE in patients with diabetes. Skin autofluorescence (AF assessed by AGE-Reader was evaluated with sRAGE and other biochemical parameters in 88 patients with diabetes (47 Type 1/T1DM/ and 41 Type 2/T2DM/ and 20 controls. Skin AF was significantly higher in T1DM and T2DM in comparison to controls (2.39 ± 0.54, 2.63 ± 0.73 versus 1.96 ± 0.33 AU; P<0.0001. Positive correlation of AF with sRAGE was detected in T1DM and T2DM (r=0.37, P<0.02 and r=0.60, P<0.0001, but not in controls. Significantly higher AF values were found in patients with positive albuminuria as compared to those with normal albuminuria. Similarly, higher AF was detected in patients with endothelial dysfunction expressed by vWF, ICAM-1, and VCAM-1. Multiple regression analysis revealed independent association of skin AF with age, sRAGE, and albumin-creatinine ratio in patients with diabetes (R2=0.38. Our study confirms that AF is elevated in patients with diabetes, especially with positive albuminuria and endothelial dysfunction. The strong and independent relationship between AF and sRAGE supports the idea that AF may reflect AGEs/RAGE interactions. The exact mechanism remains to be established.

  15. Advanced Glycation End Products Inhibit the Proliferation of Human Umbilical Vein Endothelial Cells by Inhibiting Cathepsin D

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2017-02-01

    Full Text Available We aimed to investigate the effect of advanced glycation end products (AGEs on the proliferation and migration ability of human umbilical vein endothelial cells (HUVECs. Cell proliferation was detected by methyl thiazolyl tetrazolium (MTT assay, real-time cell analyzer and 5-Ethynyl-2′-deoxyuridine (EdU staining. Cell migration was detected by wound-healing and transwell assay. AGEs significantly inhibited the proliferation and migration of HUVECs in a time-and dose-dependent way. Western blotting revealed that AGEs dramatically increased the expression of microtubule-associated protein 1 light chain 3 (LC3 II/I and p62. Immunofluorescence of p62 and acridine orange staining revealed that AGEs significantly increased the expression of p62 and the accumulation of autophagic vacuoles, respectively. Chloroquine (CQ could further promote the expression of LC3 II/I and p62, increase the accumulation of autophagic vacuoles and promote cell injury induced by AGEs. In addition, AGEs reduced cathepsin D (CTSD expression in a time-dependent way. Overexpression of wild-type CTSD significantly decreased the ratio of LC 3 II/I as well as p62 accumulation induced by AGEs, but overexpression of catalytically inactive mutant CTSD had no such effects. Only overexpression of wild-type CTSD could restore the proliferation of HUVECs inhibited by AGEs. However, overexpression of both wild-type CTSD and catalytically inactive mutant CTSD could promote the migration of HUVECs inhibited by AGEs. Collectively, our study found that AGEs inhibited the proliferation and migration in HUVECs and promoted autophagic flux, which in turn played a protective role against AGEs-induced cell injury. CTSD, in need of its catalytic activity, may promote proliferation in AGEs-treated HUVECs independent of the autophagy-lysosome pathway. Meanwhile, CTSD could improve the migration of AGEs-treated HUVECs regardless of its enzymatic activity.

  16. Naphthopyrone glucosides from the seeds of Cassia tora with inhibitory activity on advanced glycation end products (AGEs) formation.

    Science.gov (United States)

    Lee, Ga Young; Jang, Dae Sik; Lee, Yun Mi; Kim, Jong Min; Kim, Jin Sook

    2006-07-01

    Three naphthopyrone glucosides, cassiaside (1), rubrofusarin-6-O-beta-D-gentiobioside (2), and toralactone-9-O-beta-D-gentiobioside (3), were isolated from the BuOH-soluble extract of the seeds of Cassia tora as active constituents, using an in vitro bioassay based on the inhibition of advanced glycation end products (AGEs) to monitor chromatographic fractionation. The structures of 1-3 were determined by spectroscopic data interpretation, particularly by extensive 1D and 2D NMR studies. All the isolates (1-3) were evaluated for the inhibitory activity on AGEs formation in vitro.

  17. Low Levels of Serum Soluble Receptors for Advanced Glycation End Products, Biomarkers for Disease State: Myth or Reality

    OpenAIRE

    Prasad, Kailash

    2014-01-01

    Advanced glycation end products (AGEs) interact with the receptor for AGEs (RAGE) on the membrane and induce deleterious effects via activation of nuclear factor kappa-B, and increased oxidative stress and inflammatory mediators. AGEs also combine with circulating soluble receptors (endogenous secretory RAGE [esRAGE] and soluble receptor for RAGE [sRAGE]) and sequester RAGE ligands and act as a cytoprotective agent. esRAGE is secreted from the cells and is a spliced variant of RAGE. The sRAGE...

  18. Advanced glycation end-product expression is upregulated in the gastrointestinal tract of type 2 diabetic rats

    DEFF Research Database (Denmark)

    Chen, Peng-Min; Gregersen, Hans; Zhao, Jingbo

    2015-01-01

    AIM: To investigate changes in advanced glycation end products (AGEs) and their receptor (RAGE) expression in the gastrointestinal (GI) tract in type 2 diabetic rats. METHODS: Eight inherited type 2 diabetic rats Goto-Kakizak (GK) and ten age-matched normal rats were used in the study. From 18 wk...... software. RESULTS: The blood glucose concentration (mmol/L) at 18 wk age was highest in the GK group (8.88 ± 1.87 vs 6.90 ± 0.43, P end of the experiment. The wet weight per unit length (mg/cm) increased in esophagus, jejunum and colon from...

  19. Plasma advanced glycation end products (AGEs) and NF-κB activity are independent determinants of diastolic and pulse pressure

    DEFF Research Database (Denmark)

    Sourris, Karly C; Lyons, Jasmine G; Dougherty, Sonia L

    2013-01-01

    Abstract Background: High levels of circulating advanced glycation end products (AGEs) can initiate chronic low-grade activation of the immune system (CLAIS) with each of these factors independently associated with cardiovascular (CV) morbidity and mortality. Therefore, our objective...... was to characterize the relationship between serum AGEs, CLAIS and other risk factors for CV disease in normotensive non-diabetic individuals. Methods: We measured body mass index (BMI), waist-to-hip ratio (WHR), blood pressure, lipid and glucose profile in 44 non-diabetic volunteers (17 female, 27 males...

  20. Effects of zinc and manganese on advanced glycation end products (AGEs) formation and AGEs-mediated endothelial cell dysfunction.

    Science.gov (United States)

    Zhuang, Xiuyuan; Pang, Xiufeng; Zhang, Wen; Wu, Wenbin; Zhao, Jingjing; Yang, Huangjian; Qu, Weijing

    2012-01-16

    The present study investigated the effects of ZnCl₂ and MnCl₂ supplementations on advanced glycation end products (AGEs) formation and AGEs-mediated endothelial cell dysfunction. Fluorescence detection was used to monitor the Maillard reaction. Inductively coupled plasma optical emission spectroscopy was used to test cellular zinc and manganese levels. Real-time reverse transcription polymerase chain reaction and western blot were used to analyze the expression of endothelial nitric oxide synthase (eNOS), nuclear transcription factor kappa B (NF-κB), and receptor for AGEs (RAGE). Intracellular reactive oxygen species (ROS) and nitric oxide (NO) production, NOS activity were determined by fluorescent probe assay, superoxide dismutase (SOD) activity was determined by water soluble tetrazolium salt assay. MnCl₂ showed excellent inhibitory effect on AGEs formation. Primary cultured bovine aortic endothelial cells (BAECs) were exposed to AGEs for 30 min, followed by trace element treatments. Cell viability and the zinc levels declined due to AGEs exposure, which were improved with the supplementations of ZnCl₂ and MnCl₂. Furthermore, ZnCl₂ supplementation effectively enhanced intracellular NO production, elevated eNOS expression and enzymatic activity, and down-regulated NF-κB activation and RAGE expression. MnCl₂ dose-dependently impaired ROS formation, down-regulated NF-κB protein expression and nuclear translocation, as well as restored Mn-SOD enzymatic capability. Our findings suggested that trace elements relevant to diabetic, such as zinc and manganese played different roles in the formation of AGEs. Both the elements benefited the AGEs-injured BAECs through different mechanisms. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Advanced glycation end-products (AGEs accumulation in skin: relations with chronic kidney disease-mineral and bone disorder

    Directory of Open Access Journals (Sweden)

    Renata de Almeida França

    2017-08-01

    Full Text Available Abstract Introduction: Chronic kidney disease (CKD is associated with high morbidity and mortality rates, main causes related with cardiovascular disease (CVD and bone mineral disorder (CKD-BMD. Uremic toxins, as advanced glycation end products (AGEs, are non-traditional cardiovascular risk factor and play a role on development of CKD-BMD in CKD. The measurement of skin autofluorescence (sAF is a noninvasive method to assess the level of AGEs in tissue, validated in CKD patients. Objective: The aim of this study is analyze AGEs measured by sAF levels (AGEs-sAF and its relations with CVD and BMD parameters in HD patients. Methods: Twenty prevalent HD patients (HD group and healthy subjects (Control group, n = 24, performed biochemical tests and measurements of anthropometric parameters and AGEs-sAF. In addition, HD group performed measurement of intact parathormone (iPTH, transthoracic echocardiogram and radiographies of pelvis and hands for vascular calcification score. Results: AGEs-sAF levels are elevated both in HD and control subjects ranged according to the age, although higher at HD than control group. Single high-flux HD session does not affect AGEs-sAF levels. AGEs-sAF levels were not related to ventricular mass, interventricular septum or vascular calcification in HD group. AGEs-sAF levels were negatively associated with serum iPTH levels. Conclusion: Our study detected a negative correlation of AGEs-sAF with serum iPTH, suggesting a role of AGEs on the pathophysiology of bone disease in HD prevalent patients. The nature of this relation and the clinical application of this non-invasive methodology for evaluation AGEs deposition must be confirmed and clarified in future studies.

  2. Diabetic threesome (hyperglycaemia, renal function and nutrition) and advanced glycation end products: evidence for the multiple-hit agent?

    Science.gov (United States)

    Kanková, Katerina

    2008-02-01

    Complex chemical processes termed non-enzymic glycation that operate in vivo and similar chemical interactions between sugars and proteins that occur during thermal processing of food (known as the Maillard reaction) are one of the interesting examples of a potentially-harmful interaction between nutrition and disease. Non-enzymic glycation comprises a series of reactions between sugars, alpha-oxoaldehydes and other sugar derivatives and amino groups of amino acids, peptides and proteins leading to the formation of heterogeneous moieties collectively termed advanced glycation end products (AGE). AGE possess a wide range of chemical and biological properties and play a role in diabetes-related pathology as well as in several other diseases. Diabetes is, nevertheless, of particular interest for several reasons: (1) chronic hyperglycaemia provides the substrates for extracellular glycation as well as intracellular glycation; (2) hyperglycaemia-induced oxidative stress accelerates AGE formation in the process of glycoxidation; (3) AGE-modified proteins are subject to rapid intracellular proteolytic degradation releasing free AGE adducts into the circulation where they can bind to several pro-inflammatory receptors, especially receptor of AGE; (4) kidneys, which are principally involved in the excretion of free AGE adducts, might be damaged by diabetic nephropathy, which further enhances AGE toxicity because of diminished AGE clearance. Increased dietary intake of AGE in highly-processed foods may represent an additional exogenous metabolic burden in addition to AGE already present endogenously in subjects with diabetes. Finally, inter-individual genetic and functional variability in genes encoding enzymes and receptors involved in either the formation or the degradation of AGE could have important pathogenic, nutrigenomic and nutrigenetic consequences.

  3. Pioglitazone attenuates progression of aortic valve calcification via down-regulating receptor for advanced glycation end products.

    Science.gov (United States)

    Li, Fei; Cai, Zhejun; Chen, Fang; Shi, Xucong; Zhang, Qiao; Chen, Si; Shi, Jiawei; Wang, Dao Wen; Dong, Nianguo

    2012-11-01

    Receptor for advanced glycation end products (RAGE) is associated with inflammation and the progression of cardiovascular diseases. The current study tested the hypothesis that RAGE is involved in the pathogenesis of aortic valve (AV) calcification. Pioglitazone attenuated AV calcification in experimental hypercholesterolemic rabbits via down-regulation of RAGE. Male New Zealand rabbits weighing 2.5-3.0 kg were randomly divided into three groups: control group, high cholesterol + vitamin D(2) (HC + vitD(2)) group and HC + vitD(2) supplemented with pioglitazone group. Compared with HC + vitD(2) group, pioglitazone significantly inhibited the progression of AV calcification assessed by echocardiography. HC + vitD(2) diet markedly increased RAGE expression, oxidative stress, inflammatory cells infiltration and osteopontin expression. These changes were also significantly attenuated by administration of pioglitazone. Cultured porcine aortic valve interstitial cells (VICs) were used as in vitro model. We found that advanced glycation end products of bovine serum albumin markedly increased the expression of RAGE, induced high levels of production of pro-inflammatory cytokines and promoted osteoblastic differentiation of VICs. However, these effects were found to be remarkably suppressed by siRNA silencing of RAGE and pioglitazone as well. Our data provide evidence that RAGE activation-induced inflammation promotes AV calcification in hypercholesterolemic rabbits, which can be attenuated by pioglitazone treatment. This beneficial effect is associated with remarkable down-regulation of RAGE expression.

  4. Morphological adaptation of muscle collagen and receptor of advanced glycation end product (RAGE) in osteoarthritis patients with 12 weeks of resistance training

    DEFF Research Database (Denmark)

    Mattiello-Sverzut, Ana Claudia; Petersen, Susanne G; Kjaer, Michael

    2013-01-01

    The aim of this study was to investigate the effect of 12-week resistance training on morphological presence of collagen and RAGE (receptor for advanced glycation end products) in skeletal muscle of patients with knee osteoarthritis (OA). Little is known about the influence of exercise on the ske......The aim of this study was to investigate the effect of 12-week resistance training on morphological presence of collagen and RAGE (receptor for advanced glycation end products) in skeletal muscle of patients with knee osteoarthritis (OA). Little is known about the influence of exercise....... The patients (age 55-69 years) were divided into three groups, treated with NSAID, glucosamine or placebo. In addition, the muscle samples were analysed by immunohistochemistry for collagen types, RAGE and capillaries ratio. An increment in immunoreactivity for type IV collagen after the training period...... was observed in 72 % of all biopsies when compared with their respective baseline samples. Reduced immunoreactivity of collagen type I was observed in all patients treated with glucosamine. A significant increase with training in the amount of RAGE was detected in the placebo group only (p ...

  5. Hyperoside Downregulates the Receptor for Advanced Glycation End Products (RAGE and Promotes Proliferation in ECV304 Cells via the c-Jun N-Terminal Kinases (JNK Pathway Following Stimulation by Advanced Glycation End-Products In Vitro

    Directory of Open Access Journals (Sweden)

    Zhengyu Zhang

    2013-11-01

    Full Text Available Hyperoside is a major active constituent in many medicinal plants which are traditionally used in Chinese medicines for their neuroprotective, anti-inflammatory and antioxidative effects. The molecular mechanisms underlying these effects are unknown. In this study, quiescent ECV304 cells were treated in vitro with advanced glycation end products (AGEs in the presence or absence of hyperoside. The results demonstrated that AGEs induced c-Jun N-terminal kinases (JNK activation and apoptosis in ECV304 cells. Hyperoside inhibited these effects and promoted ECV304 cell proliferation. Furthermore, hyperoside significantly inhibited RAGE expression in AGE-stimulated ECV304 cells, whereas knockdown of RAGE inhibited AGE-induced JNK activation. These results suggested that AGEs may promote JNK activation, leading to viability inhibition of ECV304 cells via the RAGE signaling pathway. These effects could be inhibited by hyperoside. Our findings suggest a novel role for hyperoside in the treatment and prevention of diabetes.

  6. Hyperoside Downregulates the Receptor for Advanced Glycation End Products (RAGE) and Promotes Proliferation in ECV304 Cells via the c-Jun N-Terminal Kinases (JNK) Pathway Following Stimulation by Advanced Glycation End-Products In Vitro

    Science.gov (United States)

    Zhang, Zhengyu; Sethiel, Mosha Silas; Shen, Weizhi; Liao, Sentai; Zou, Yuxiao

    2013-01-01

    Hyperoside is a major active constituent in many medicinal plants which are traditionally used in Chinese medicines for their neuroprotective, anti-inflammatory and antioxidative effects. The molecular mechanisms underlying these effects are unknown. In this study, quiescent ECV304 cells were treated in vitro with advanced glycation end products (AGEs) in the presence or absence of hyperoside. The results demonstrated that AGEs induced c-Jun N-terminal kinases (JNK) activation and apoptosis in ECV304 cells. Hyperoside inhibited these effects and promoted ECV304 cell proliferation. Furthermore, hyperoside significantly inhibited RAGE expression in AGE-stimulated ECV304 cells, whereas knockdown of RAGE inhibited AGE-induced JNK activation. These results suggested that AGEs may promote JNK activation, leading to viability inhibition of ECV304 cells via the RAGE signaling pathway. These effects could be inhibited by hyperoside. Our findings suggest a novel role for hyperoside in the treatment and prevention of diabetes. PMID:24252909

  7. Clinical Value of High Mobility Group Box 1 and the Receptor for Advanced Glycation End-products in Head and Neck Cancer: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Nguyen, Austin

    2016-04-01

    Full Text Available Introduction High mobility group box 1 is a versatile protein involved in gene transcription, extracellular signaling, and response to inflammation. Extracellularly, high mobility group box 1 binds to several receptors, notably the receptor for advanced glycation end-products. Expression of high mobility group box 1 and the receptor for advanced glycation end-products has been described in many cancers. Objectives To systematically review the available literature using PubMed and Web of Science to evaluate the clinical value of high mobility group box 1 and the receptor for advanced glycation end-products in head and neck squamous cell carcinomas. Data synthesis A total of eleven studies were included in this review. High mobility group box 1 overexpression is associated with poor prognosis and many clinical and pathological characteristics of head and neck squamous cell carcinomas patients. Additionally, the receptor for advanced glycation end-products demonstrates potential value as a clinical indicator of tumor angiogenesis and advanced staging. In diagnosis, high mobility group box 1 demonstrates low sensitivity. Conclusion High mobility group box 1 and the receptor for advanced glycation end-products are associated with clinical and pathological characteristics of head and neck squamous cell carcinomas. Further investigation of the prognostic and diagnostic value of these molecules is warranted.

  8. Consumption of a diet low in advanced glycation end products for 4 weeks improves insulin sensitivity in overweight women

    DEFF Research Database (Denmark)

    Mark, Alicja Budek; Poulsen, Malene Wibe; Andersen, Stine

    2014-01-01

    OBJECTIVE High-heat cooking of food induces the formation of advanced glycation end products (AGEs), which are thought to impair glucose metabolism in type 2 diabetic patients. High intake of fructose might additionally affect endogenous formation of AGEs. This parallel intervention study...... investigated whether the addition of fructose or cooking methods influencing the AGE content of food affect insulin sensitivity in overweight individuals. RESEARCH DESIGN AND METHODS Seventy-four overweight women were randomized to follow either a high- or low-AGE diet for 4 weeks, together with consumption...... AGE concentrations were measured (liquid chromatography tandem mass spectrometry) to estimate AGE intake and excretion. RESULTS When adjusted for changes in anthropometric measures during the intervention, the low-AGE diet decreased urinary AGEs, fasting insulin concentrations, and HOMA-IR, compared...

  9. Soluble receptor for advanced glycation end-product levels are related to albuminuria and arterial stiffness in essential hypertension.

    Science.gov (United States)

    Dimitriadis, K; Tsioufis, C; Kasiakogias, A; Miliou, A; Poulakis, M; Kintis, K; Bafakis, I; Benardis, E; Tousoulis, D; Stefanadis, C

    2013-04-01

    Emerging evidence suggests that the soluble receptor for advanced glycation end-products (sRAGE) is implicated in the development of vascular disease. We investigated the interrelationships of sRAGE with albumin to creatinine ratio (ACR) and arterial stiffness in essential hypertension. In 309 untreated non-diabetic hypertensives, ACR values were determined as the mean of three non-consecutive morning spot urine samples and aortic stiffness was evaluated on the basis of carotid to femoral pulse wave velocity (c-f PWV). In all subjects, venous blood sampling was performed for the estimation of sRAGE levels. Patients with low (n = 155) compared to those with high sRAGE values (n = 154) had greater 24-h systolic BP (140 ± 8 vs. 134 ± 7 mmHg, p involvement of sRAGE in the progression of hypertensive vascular damage. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Advanced glycation end products promote differentiation of CD4(+) T helper cells toward pro-inflammatory response.

    Science.gov (United States)

    Han, Xiao-qun; Gong, Zuo-jiong; Xu, San-qing; Li, Xun; Wang, Li-kun; Wu, Shi-min; Wu, Jian-hong; Yang, Hua-fen

    2014-02-01

    This study investigated the effect of advanced glycation end products (AGEs) on differentiation of naïve CD4(+) T cells and the role of the receptor of AGEs (RAGE) and peroxisome proliferator-activated receptors (PPARs) activity in the process in order to gain insight into the mechanism of immunological disorders in diabetes. AGEs were prepared by the reaction of bovine serum albumin (BSA) with glucose. Human naïve CD4(+) T cells, enriched from blood of healthy adult volunteers with negative selection assay, were cultured in vitro and treated with various agents including AGEs, BSA, high glucose, PGJ2 and PD68235 for indicated time. In short hairpin (sh) RNA knock-down experiment, naïve CD4(+) T cells were transduced with media containing shRNA-lentivirus generated from lentiviral packaging cell line, Lent-X(TM) 293 T cells. Surface and intracellular cytokine stainings were used for examination of CD4(+) T cell phenotypes, and real-time PCR and Western blotting for detection of transcription factor mRNA and protein expression, respectively. The suppressive function of regulatory T (Treg) cells was determined by a [(3)H]-thymidine incorporation assay. The results showed that AGEs induced higher pro-inflammatory Th1/Th17 cells differentiated from naïve CD4(+) T cells than the controls, whereas did not affect anti-inflammatory Treg cells. However, AGEs eliminated suppressive function of Treg cells. In addition, AGEs increased RAGE mRNA expression in naïve CD4(+) T cells, and RAGE knock-down by shRNA eliminated the effect of AGEs on the differentiation of CD4(+) T cells and the reduction of suppressive function of Treg cells. Furthermore, AGEs inhibited the mRNA expression of PPARγ, not PPARα PPARγ agonist, PGJ2, inhibited the effect of AGEs on naïve CD4(+) T cell differentiation and reversed the AGE-reduced suppressive function of Treg cells; on the other hand, PPARγ antagonist, PD68235, attenuated the blocking effect of RAGE shRNA on the role of AGEs. It

  11. Skin advanced glycation end products in HIV infection are increased and predictive of development of cardiovascular events.

    Science.gov (United States)

    Sprenger, Herman G; Bierman, Wouter F; Martes, Melanie I; Graaff, Reindert; van der Werf, Tjip S; Smit, Andries J

    2017-01-14

    HIV-1 infection is associated with an increased cardiovascular disease (CVD) risk. Advanced glycation end products are formed as stable markers of glycaemic and oxidative stress. Skin autofluorescence (SAF) as marker of accumulated advanced glycation end products is increased and predictive of CVD events in diabetes mellitus, chronic kidney disease (CKD), and preexisting CVD. We determined SAF levels in HIV-1 infected patients, testing the hypothesis that SAF predicts CVD events in HIV infection. Single-centre prospective cohort study. In 2010-2011, SAF was measured in 91 patients. Development of CVD events was monitored during a median follow-up of 4.8 years. SAF values of the patients were expressed as a ratio (rSAF) to expected SAF levels in age-matched healthy volunteers. Seventy-nine men and 12 women were included, mean age 47 years; 81 patients were on combination antiretroviral therapy. With a mean rSAF of 1.155, SAF levels in patients were 15.5% higher than predicted for their age (95% confidence interval, 10.0-20.0; P multivariate regression analysis, rSAF was associated with nadir CD4 cell count less than 200 cells/μl (β -0.274; P = 0.01), smoking (β 0.240; P = 0.03), and men who have sex with men (MSM) (β 0.202; P = 0.07). CVD events occurred in six patients (7%). In Cox regression analysis including age, SAF, smoking, diabetes, hypertension and CKD, SAF (P = 0.01), and (Wet Medisch-wetenschappelijk Onderzoek met mensen; WMO) CKD (P = 0.03) remained as independent predictors of CVD events. SAF is increased in HIV-infected patients, and related with smoking, low nadir CD4 cell count, and MSM. Larger studies are needed to confirm whether SAF is an independent predictor of CVD events.

  12. Beneficial effects of metformin and irbesartan on advanced glycation end products (AGEs)-RAGE-induced proximal tubular cell injury.

    Science.gov (United States)

    Ishibashi, Yuji; Matsui, Takanori; Takeuchi, Masayoshi; Yamagishi, Sho-ichi

    2012-03-01

    Advanced glycation end products (AGEs) and their receptor (RAGE) axis contributes to diabetic nephropathy. An oral hypoglycemic agent, metformin may have a potential effect on the inhibition of glycation reactions. Further, since a pathophysiological crosstalk between renin-angiotensin system (RAS) and AGEs-RAGE axis is involved in diabetic nephropathy, it is conceivable that metformin and irbesartan additively could protect against the AGEs-RAGE-induced tubular cell injury. In this study, we addressed the issues. Metformin dose-dependently inhibited the formation of AGEs modification of bovine serum albumin (BSA). Compared with AGEs-modified BSA prepared without metformin (AGEs-MF0), those prepared in the presence of 30 mM or 100 mM metformin (AGEs-MF30 or AGEs-MF100) significantly reduced RAGE mRNA level, reactive oxygen species (ROS) generation, apoptosis, monocyte chemoattractant protein-1 and transforming growth factor-β mRNA level in tubular cells. Irbesartan further inhibited the harmful effects of AGEs-MF0 or AGEs-MF30 on tubular cells. Our present study suggests that combination therapy with metformin and irbesartan may have therapeutic potential in diabetic nephropathy; it could play a protective role against tubular injury in diabetes not only by inhibiting AGEs formation, but also by attenuating the deleterious effects of AGEs via down-regulating RAGE expression and subsequently suppressing ROS generation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Predictive value of advanced glycation end products for the development of post-infarction heart failure: a preliminary report

    Directory of Open Access Journals (Sweden)

    Raposeiras-Roubín Sergio

    2012-08-01

    Full Text Available Abstract Background Since post-infarction heart failure (HF determines a great morbidity and mortality, and given the physiopathology implications of advanced glycation end products (AGE in the genesis of myocardial dysfunction, it was intended to analyze the prognostic value of these molecules in order to predict post-infarction HF development. Methods A prospective clinical study in patients after first acute coronary syndrome was conducted. The follow-up period was consisted in 1 year. In 194 patients consecutively admitted in the coronary unit for myocardial infarct fluorescent AGE levels were measured. The association between glycaemic parameters and the development of post-infarction HF were analyzed in those patients. Finally, we identified the variables with independent predictor value by performing a multivariate analysis of Hazard ratio for Cox regression. Results Eleven out of 194 patients (5.6% developed HF during follow-up (median: 1.0 years [0.8 - 1.5 years]. Even though basal glucose, fructosamine and glycated haemoglobin were significant predictive factors in the univariate analysis, after being adjusted by confounding variables and AGE they lost their statistical signification. Only AGE (Hazard Ratio 1.016, IC 95%: 1.006-1.026; p Conclusions AGE are an independent marker of post-infarction HF development risk.

  14. High serum level of pentosidine, an advanced glycation end product (AGE), is a risk factor of patients with heart failure.

    Science.gov (United States)

    Koyama, Yo; Takeishi, Yasuchika; Arimoto, Takanori; Niizeki, Takeshi; Shishido, Tetsuro; Takahashi, Hiroki; Nozaki, Naoki; Hirono, Osamu; Tsunoda, Yuichi; Nitobe, Joji; Watanabe, Tetsu; Kubota, Isao

    2007-04-01

    Pentosidine, one of the advanced glycation end products (AGE), is generated by nonenzymatic glycation and oxidation of proteins. The receptor of AGE (RAGE) is expressed in a variety of tissue, and interaction of AGE with RAGE induces oxidative stress and activation of intracellular signaling, causing production of cytokines and mediators of inflammation. We investigated whether serum pentosidine is a risk factor for heart failure. Serum pentosidine concentration was measured in 141 patients with heart failure and 18 control subjects by a competitive enzyme-linked immunosorbent assay. Patients were prospectively followed during a median follow-up period of 479 days with end points of cardiac death or rehospitalization. Serum concentration of pentosidine was significantly higher in New York Heart Association (NYHA) Class III/IV patients than in NYHA class I/II patients (P volume, and left ventricular mass were significant risk factors to predict cardiac events. In the multivariate Cox analysis, serum pentosidine concentration was an independent risk factor for cardiac events (hazard ratio 1.88, 95% confidence interval 1.23-2.69, P = .002). The highest 4th quartile of pentosidine was associated with the highest risk of cardiac events (4.52-fold). Serum pentosidine concentration is an independent prognostic factor for heart failure, and this new marker may be useful for risk stratification of patients with heart failure. Patients were divided into 4 groups based on the serum pentosidine levels.

  15. Phlorotannins from Brown Algae: inhibition of advanced glycation end products formation in high glucose induced Caenorhabditis elegans.

    Science.gov (United States)

    Shakambari, Ganeshan; Ashokkumar, Balasubramaniem; Varalakshmi, Perumal

    2015-06-01

    Advanced Glycation End products (AGE) generated in a non enzymatic protein glycation process are frequently associated with diabetes, aging and other chronic diseases. Here, we explored the protective effect of phlorotannins from brown algae Padina pavonica, Sargassum polycystum and Turbinaria ornata against AGEs formation. Phlorotannins were extracted from brown algae with methanol and its purity was analyzed by TLC and RP-HPLC-DAD. Twenty five grams of P. pavonica, S. polycystum, T. ornata yielded 27.6 ± 0.8 μg/ml, 37.7 μg/ml and 37.1 ± 0.74 μg/ml of phloroglucinol equivalent of phlorotannins, respectively. Antioxidant potentials were examined through DPPH assay and their IC50 values were P. pavonica (30.12 ± 0.99 μg), S. polycystum (40.9 ± 1.2 μg) and T. ornata (22.9 ± 1.3 μg), which was comparatively lesser than the control ascorbic acid (46 ± 0.2 μg). Further, anti-AGE activity was examined in vitro by BSA-glucose assay with the extracted phlorotannins of brown algae (P. pavonica, 15.16 ± 0.26 μg/ml; S. polycystum, 35.245 ± 2.3 μg/ml; T. ornata, 22.7 ± 0.3 μg/ml), which revealed the required concentration to inhibit 50% of albumin glycation (IC50) were lower for extracts than controls (phloroglucinol, 222.33 ± 4.9 μg/ml; thiamine, 263 μg/ml). Furthermore, brown algal extracts containing phlorotannins (100 μl) exhibited protective effects against AGE formation in vivo in C. elegans with induced hyperglycemia.

  16. Higher plasma soluble Receptor for Advanced Glycation End Products (sRAGE) levels are associated with incident cardiovascular disease and all-cause mortality in type 1 diabetes

    DEFF Research Database (Denmark)

    Nin, Johanna W M; Jorsal, Anders; Ferreira, Isabel

    2010-01-01

    To investigate the associations of plasma levels of soluble receptor for advanced glycation end products (sRAGE) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunct......To investigate the associations of plasma levels of soluble receptor for advanced glycation end products (sRAGE) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal...

  17. The receptor for advanced glycation end products RAGE is involved in corneal healing.

    Science.gov (United States)

    Nass, Norbert; Trau, Stefanie; Paulsen, Friedrich; Kaiser, Delia; Kalinski, Thomas; Sel, Saadettin

    2017-05-01

    Impaired corneal healing is still a major cause of blindness. As RAGE (receptor for advanced glycation endproducts) is involved in inflammation and wound healing in other tissues, we here investigated its relevance for corneal wound healing. Corneal re-epithelialization after alkaline injury was analysed in an ex-vivo approach with cultured, enucleated eyes from mice either of the C57Bl/6 NChR genotype (RAGE+/+) and mice of the same strain lacking the RAGE gene (RAGE-/-). The wound area was determined time dependently by fluorescence imaging using fluorescein staining. The eyes of RAGE-/- mice showed a significantly slower re-epithelialization than eyes of the RAGE+/- and the RAGE+/+ genotype. In immunohistochemistry, RAGE expression was increased in wounded corneas whereas the abundance of the RAGE ligand HMGB1 was unaffected, but an increase in S100b-like proteins was revealed upon injury. However, neither the addition of the RAGE agonist HMGB1 or an HMGB1 antagonising antibody nor bovine S100b protein to the culture medium of the wounded eyes had an effect on corneal wound closure in ex-vivo. Further gene expression analysis by RT-PCR demonstrated an increase in RAGE expression on the mRNA level, no significant regulation of HMGB1 and a differential regulation of the S100 gene family after alkaline burn of the cornea. In conclusion, RAGE is clearly involved in corneal re-epithelialization most probably mediated by signalling via S100 proteins. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. [Correlation of the expressions of advanced glycation end products and its receptor in serum and placenta with the pathogenesis of preeclampsia].

    Science.gov (United States)

    Xian, Na; Chen, Weiping; Zhang, Yan; Li, Jing; Zhang, Ning; Ye, Yuanhua

    2015-07-01

    To investigate the correlation of the expressions of advanced glycation end products (AGE) and the receptor for advanced glycation end products (RAGE) in serum and placenta with the pathogenesis of preeclampsia. From December 2013 to June 2014, 32 women with severe preeclampsia who received cesarean section in the Affiliated Hospital of Qingdao University were recruited in the study, defined as the severe preeclampsia group. 30 healthy pregnant women who received cesarean section in the same hospital were recruited as the control group. ELISA was used to measure the maternal serum AGE, soluble receptor for advanced glycation end products (sRAGE) and tumor necrosis factor-α (TNF-α) in these women. Furthermore, ELISA was also used to measure AGE and TNF-α in the placenta. The localizations of AGE and RAGE protein in placentas were detected by immunohistochemical SP method. RAGE and TNF-α mRNA expression in placentas were measured by real-time quantitative PCR. AGE, RAGE and TNF-α protein expression in placentas were measured by western blot, respectively. (1) The serum levels of AGE, sRAGE and TNF-α in the severe preeclampsia group were (538 ± 75), (367 ± 86) and (322 ± 40) ng/L, respectively. They were significantly higher than those in the control group [(454 ± 50), (286 ± 35) and (270 ± 35) ng/L, respectively] (P 0.05). (2) In the severe preeclampsia group, the levels of AGE and TNF-α in placentas were (500 ± 82) and (334 ± 57) ng/L, which were higher than those in the control group [(431 ± 74) and (263 ± 46) ng/L, respectively] (P preeclampsia group were 12.6 ± 4.6 and 10.4 ± 2.4, which were significantly higher than those in the control group (0.9 ± 0.4 and 3.5 ± 0.9, P preeclampsia group were 0.68 ± 0.06, 0.82 ± 0.08 and 0.76 ± 0.08. All were significantly higher than those of the control group (0.46 ± 0.05, 0.42 ± 0.09 and 0.52 ± 0.07; P preeclampsia group, and the expression of TNF-α also elevated. These indicated that AGE and RAGE

  19. Binding of receptor for advanced glycation end products (RAGE) ligands is not sufficient to induce inflammatory signals: lack of activity of endotoxin-free albumin-derived advanced glycation end products.

    Science.gov (United States)

    Valencia, J V; Mone, M; Koehne, C; Rediske, J; Hughes, T E

    2004-05-01

    Activation of the receptor for advanced glycation end products (RAGE) reportedly triggers cellular responses implicated in the pathogenesis of diabetes, such as increasing vascular cell adhesion molecule-1 (VCAM-1) expression on vascular endothelial cells and inducing TNF-alpha secretion by mononuclear cells. The objective of this study was to evaluate whether RAGE binding affinity of AGE-BSAs and cellular activation correlate. To produce AGEs with varying glycation, bovine albumin AGEs were prepared with 500 mmol/l of glucose, fructose or ribose at times of incubation from 1 to 12 weeks. In addition, AGE-BSA was generated using either glyoxylic acid or glycolaldehyde. Cellular binding of the AGE-BSAs and the effect on endothelial cell VCAM-1 expression were studied in RAGE-expressing human microvascular endothelial cell line-4 cells. Induction of TNF-alpha secretion was assessed using RAGE-expressing human peripheral blood mononuclear cells (PBMCs). Cellular binding of the different AGE preparations correlated well with RAGE affinity. Interestingly, we found that the AGE preparations, which were essentially endotoxin free (RAGE binding affinity, AGE concentration or incubation time. In contrast, the reported RAGE ligand S100b was confirmed to induce VCAM-1 expression on endothelial cells and TNF-alpha secretion by PBMCs after 24 h of treatment. The results of this study suggest that AGE modification and high RAGE binding affinity are not sufficient to generate pro-inflammatory signalling molecules. Thus, RAGE binding affinity of AGE-BSAs does not seem to correlate with cellular activation. Our findings using AGEs with strong RAGE-binding properties indicate that AGEs may not uniformly play a role in cellular activation.

  20. Age-related accumulation of advanced glycation end-products-albumin, S100β, and the expressions of advanced glycation end product receptor differ in visceral and subcutaneous fat

    Energy Technology Data Exchange (ETDEWEB)

    Son, Kuk Hui [Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon (Korea, Republic of); Son, Myeongjoo [Department of Anatomy and Cell Biology, Gachon University Graduate School of Medicine, Incheon (Korea, Republic of); Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon (Korea, Republic of); Ahn, Hyosang; Oh, Seyeon; Yum, Yoonji [Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon (Korea, Republic of); Choi, Chang Hu [Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon (Korea, Republic of); Park, Kook Yang, E-mail: kkyypark@ghil.com [Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon (Korea, Republic of); Byun, Kyunghee, E-mail: khbyun1@gachon.ac.kr [Department of Anatomy and Cell Biology, Gachon University Graduate School of Medicine, Incheon (Korea, Republic of); Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon (Korea, Republic of)

    2016-08-19

    Visceral fat induces more inflammation by activating macrophages than subcutaneous fat, and inflammation is an underlying feature of the pathogeneses of various diseases, including cardiovascular disease and diabetes. Advanced glycation end products (AGEs), S100β, and their receptors, the receptor for advanced glycation end products (RAGE), lead to macrophage activation. However, little information is available regarding the differential accumulations of AGE-albumin (serum albumin modified by AGEs), S100β, or expressions of RAGE in different adipocyte types in fat tissues. In this study, the authors investigated whether age-related AGE-albumin accumulations S100β level, and RAGE expressions differ in subcutaneous and visceral fat tissues. Subcutaneous and visceral fat were harvested from 3- and 28-week-old rats. Macrophage activation was confirmed by Iba1 staining, and AGE-albumin accumulations and RAGE expressions were assessed by confocal microscopy. S100β were analyzed by immunoblotting. It was found that activated macrophage infiltration, AGE-albumin accumulation, and S100β in visceral fat was significantly greater in 28-week-old rats than in 3-week-old rats, but similar in subcutaneous fat. The expression of RAGE in visceral fat was much greater in 28-week-old rats, but its expression in subcutaneous fat was similar in 3- and 28-week-old rats. Furthermore, inflammatory signal pathways (NFκB, TNF-α) and proliferation pathways (FAK) in visceral fat were more activated in 28-week-old rats. These results imply that age-related AGE-albumin accumulation, S100β, and RAGE expression are more prominent in visceral than in subcutaneous fat, suggesting that visceral fat is involved in the pathogenesis of inflammation-induced diseases in the elderly. - Highlights: • The age-related AGE-albumin accumulation and S100β were more prominent in visceral than subcutaneous fat. • The age-related RAGE expression were more prominent in visceral than subcutaneous fat.

  1. Age-related accumulation of advanced glycation end-products-albumin, S100β, and the expressions of advanced glycation end product receptor differ in visceral and subcutaneous fat

    International Nuclear Information System (INIS)

    Son, Kuk Hui; Son, Myeongjoo; Ahn, Hyosang; Oh, Seyeon; Yum, Yoonji; Choi, Chang Hu; Park, Kook Yang; Byun, Kyunghee

    2016-01-01

    Visceral fat induces more inflammation by activating macrophages than subcutaneous fat, and inflammation is an underlying feature of the pathogeneses of various diseases, including cardiovascular disease and diabetes. Advanced glycation end products (AGEs), S100β, and their receptors, the receptor for advanced glycation end products (RAGE), lead to macrophage activation. However, little information is available regarding the differential accumulations of AGE-albumin (serum albumin modified by AGEs), S100β, or expressions of RAGE in different adipocyte types in fat tissues. In this study, the authors investigated whether age-related AGE-albumin accumulations S100β level, and RAGE expressions differ in subcutaneous and visceral fat tissues. Subcutaneous and visceral fat were harvested from 3- and 28-week-old rats. Macrophage activation was confirmed by Iba1 staining, and AGE-albumin accumulations and RAGE expressions were assessed by confocal microscopy. S100β were analyzed by immunoblotting. It was found that activated macrophage infiltration, AGE-albumin accumulation, and S100β in visceral fat was significantly greater in 28-week-old rats than in 3-week-old rats, but similar in subcutaneous fat. The expression of RAGE in visceral fat was much greater in 28-week-old rats, but its expression in subcutaneous fat was similar in 3- and 28-week-old rats. Furthermore, inflammatory signal pathways (NFκB, TNF-α) and proliferation pathways (FAK) in visceral fat were more activated in 28-week-old rats. These results imply that age-related AGE-albumin accumulation, S100β, and RAGE expression are more prominent in visceral than in subcutaneous fat, suggesting that visceral fat is involved in the pathogenesis of inflammation-induced diseases in the elderly. - Highlights: • The age-related AGE-albumin accumulation and S100β were more prominent in visceral than subcutaneous fat. • The age-related RAGE expression were more prominent in visceral than subcutaneous fat.

  2. Diet-derived advanced glycation end products or lipofuscin disrupts proteostasis and reduces life span in Drosophila melanogaster.

    Science.gov (United States)

    Tsakiri, Eleni N; Iliaki, Kalliopi K; Höhn, Annika; Grimm, Stefanie; Papassideri, Issidora S; Grune, Tilman; Trougakos, Ioannis P

    2013-12-01

    Advanced glycation end product (AGE)-modified proteins are formed by the nonenzymatic glycation of free amino groups of proteins and, along with lipofuscin (a highly oxidized aggregate of covalently cross-linked proteins, sugars, and lipids), have been found to accumulate during aging and in several age-related diseases. As the in vivo effects of diet-derived AGEs or lipofuscin remain elusive, we sought to study the impact of oral administration of glucose-, fructose-, or ribose-modified albumin or of artificial lipofuscin in a genetically tractable model organism. We report herein that continuous feeding of young Drosophila flies with culture medium enriched in AGEs or in lipofuscin resulted in reduced locomotor performance and in accelerated rates of AGE-modified proteins and carbonylated proteins accumulation in the somatic tissues and hemolymph of flies, as well as in a significant reduction of flies health span and life span. These phenotypic effects were accompanied by reduced proteasome peptidase activities in both the hemolymph and the somatic tissues of flies and higher levels of oxidative stress; furthermore, oral administration of AGEs or lipofuscin in flies triggered an upregulation of the lysosomal cathepsin B, L activities. Finally, RNAi-mediated cathepsin D knockdown reduced flies longevity and significantly augmented the deleterious effects of AGEs and lipofuscin, indicating that lysosomal cathepsins reduce the toxicity of diet-derived AGEs or lipofuscin. Our in vivo studies demonstrate that chronic ingestion of AGEs or lipofuscin disrupts proteostasis and accelerates the functional decline that occurs with normal aging. © 2013 Elsevier Inc. All rights reserved.

  3. Skin autofluorescence, a non-invasive biomarker for advanced glycation end products, is associated with the metabolic syndrome and its individual components

    NARCIS (Netherlands)

    van Waateringe, Robert P.; Slagter, Sandra N.; van Beek, Andre P.; van der Klauw, Melanie M.; van Vliet-Ostaptchouk, Jana V.; Graaff, Reindert; Paterson, Andrew D.; Lutgers, Helen L.; Wolffenbuttel, Bruce H. R.

    2017-01-01

    Background: The metabolic syndrome (MetS) comprises several cardiometabolic risk factors associated with increased risk for both type 2 diabetes and cardiovascular disease. Skin autofluorescence (SAF), a non-invasive bio-marker of advanced glycation end products accumulation, is associated with

  4. Systemic stiffening of mouse tail tendon is related to dietary advanced glycation end products but not high-fat diet or cholesterol

    DEFF Research Database (Denmark)

    Eriksen, Christian; Svensson, R B; Scheijen, J

    2014-01-01

    Tendon pathology is related to metabolic disease and mechanical overloading, but the effect of metabolic disease on tendon mechanics is unknown. This study investigated the effect of diet and apolipoprotein E deficiency (ApoE(-/-)) on mechanical properties and advanced glycation end product (AGE...... cross-links in tendons and for tissue compliance. The results demonstrate how systemic metabolic factors may influence tendon health....

  5. Skin autofluorescence is elevated in patients with stable coronary artery disease and is associated with serum levels of neopterin and the soluble receptor for advanced glycation end products

    NARCIS (Netherlands)

    Mulder, Douwe J.; van Haelst, Paul L.; Gross, Sascha; de Leeuw, Karina; Bijzet, Johannes; Graaff, Reindert; Gans, Rijk O.; Zijlstra, Felix; Smit, Andries J.

    Aims: To investigate whether skin autofluorescence (AF), a non-invasive marker for advanced glycation end products (AGEs), is elevated in stable coronary artery disease (sCAD) and to investigate its relationship with serum levels of the soluble receptor for AGEs (sRAGE), neopterin and C-reactive

  6. Polymorphism screening of four genes encoding advanced glycation end-product putative receptors. Association study with nephropathy in type 1 diabetic patients

    DEFF Research Database (Denmark)

    Poirier, Odette; Nicaud, Viviane; Vionnet, N

    2001-01-01

    Advanced glycation end-products (AGEs) may play an important role in the pathogenesis and progression of cardiovascular and renal complications of diabetes. Four putative AGE receptors (RAGEs), AGE-R1, AGE-R2, and AGE-R3 have been described. In this study, we scanned the sequence of the genes enc...

  7. Increase in production of matrix metalloproteinase 13 by human articular chondrocytes due to stimulation with S100A4: Role of the receptor for advanced glycation end products.

    Science.gov (United States)

    Yammani, Raghunatha R; Carlson, Cathy S; Bresnick, Anne R; Loeser, Richard F

    2006-09-01

    S100 proteins have been implicated in various inflammatory conditions, including arthritis. The aims of this study were to determine whether chondrocytes produce S100A4 and whether S100A4 can stimulate the production of matrix metalloproteinase 13 (MMP-13) by articular chondrocytes via receptor for advanced glycation end products (RAGE)-mediated signaling. The expression of chondrocyte S100A4 was analyzed by immunohistochemistry using normal and osteoarthritic (OA) cartilage and by immunoblotting of chondrocyte cell lysates. RAGE signaling was examined by stimulating chondrocytes with S100A4 and monitoring for the activation of MAP kinases and NF-kappaB. Production of MMP-13 was determined in the conditioned medium. A pulldown assay using biotin-labeled S100A4 was used to demonstrate binding to RAGE. S100A4 expression was detected in human articular chondrocytes by immunoblotting and appeared to increase in the cell lysates from OA tissue. Marked positive immunostaining for S100A4 was also noted in sections of human cartilage with changes due to OA. Stimulation of chondrocytes with S100A4 increased the phosphorylation of Pyk-2, MAP kinases, and activated NF-kappaB, followed by increased production of MMP-13 in the conditioned medium. This signaling was inhibited in cells pretreated with soluble RAGE, advanced glycation end product-bovine serum albumin, or the antioxidant Mn(III)tetrakis (4-benzoic acid) porphyrin, or by overexpression of a dominant-negative RAGE construct. A pulldown assay showed that S100A4 binds to RAGE in chondrocytes. This is the first study to demonstrate that S100A4 binds to RAGE and stimulates a RAGE-mediated signaling cascade, leading to increased production of MMP-13. Since both S100A4 and RAGE are up-regulated in OA cartilage, this signaling pathway could contribute to cartilage degradation in OA.

  8. Relationship between advanced glycation end-products with the severity of chronic heart failure in 85 patients

    Directory of Open Access Journals (Sweden)

    Amir Farhang Zand Parsa

    2013-12-01

    Full Text Available Background: Advanced glycation end-products (AGEs came up with the recent researches regarding new biomarkers for the diagnosis of heart failure. AGEs are the end products of non-enzymatic glycation and oxidation of proteins, lipids and nucleotides during Maillard biochemical reaction. Although it has been known that AGEs have a role in the pathogenesis of chronic heart failure (CHF, information regarding its role and its pathogenetic mechanism is very limited. The aim of this study was to find any relationship between AGEs with the etiology and severity of chronic heart failure.Methods: This study is a prospective cross sectional study that enrolled 85 patients with chronic heart failure. Measurement of left ventricle ejection fraction (LVEF was done by echocardiography. Blood samples were collected for measuring AGEs just before or after echocardiography assessment (in the same session. Measurement of AGEs was done by the enzyme-linked immunosorbent assay (ELISA method. The relationship between AGEs with the severity of CHF and as well as the etiology of CHF were evaluated via SPSS-15.Results: Of 85 patients 48 (56.5% patients were male and 37 (43.5% were female; Mean±SD of their ages was 55.8±13.4 years old (ranges from 27 to 84 years. Correlation coefficient between LVEF and AGEs was 0.269 (P=0.013. Mean of AGEs in patients with and without ischemic etiology of their heart failure were 16.8±9.8µg/ml and 11.6±7.3 µg/ml, respectively. Although trend was in favor of ischemic heart failure, the difference between two groups was not statistically significant (P= 0.141.Conclusion: According to this study the rate of AGES could be helpful in the diagnosis and assessment of severity of CHF. Based on our findings, higher blood levels of AGEs in the ischemic CHF cases, also it could be concluded that in the future this marker may be used for etiologic differentiation of heart failure syndrome.

  9. The Extract of Litsea japonica Reduced the Development of Diabetic Nephropathy via the Inhibition of Advanced Glycation End Products Accumulation in db/db Mice

    Directory of Open Access Journals (Sweden)

    Eunjin Sohn

    2013-01-01

    Full Text Available Increasing evidence indicates that advanced glycation end products (AGEs contribute to the pathogenesis of diabetic nephropathy. The aim of this study was to investigate the protective effect of L. japonica extract (LJE against renal damage in the db/db mouse. LJE (100 or 250 mg/kg per day was given to diabetic mice for 12 weeks. Body weight, blood glucose levels, glycated hemoglobin (HbA1c levels, and proteinuria were examined. In in vitro assay of the inhibition of AGE formation, immunohistochemical analysis of podocyte loss and AGE accumulations were performed. In 20-week-old db/db mice, severe hyperglycemia developed, and proteinuria was significantly increased. Diabetes induced markedly morphological alterations to the renal glomerular cells. AGE accumulations and podocyte loss were detected in renal glomeruli. LJE treatment significantly reduced proteinuria and AGE accumulations in diabetic mice. Moreover, the loss of nephrin, an important slit diaphragm component in the kidneys, was restored by LJE treatment. Our studies suggest that LJE might be beneficial for the treatment of diabetic nephropathy. The ability of LJE to attenuate proteinuria and podocyte dysfunction may be mediated by the inhibition of AGE accumulation in the context of diabetic nephropathy in db/db mice.

  10. Advanced glycation end products and their receptor in age-related, non-communicable chronic inflammatory diseases; Overview of clinical evidence and potential contributions to disease.

    Science.gov (United States)

    Reynaert, Niki L; Gopal, Poornima; Rutten, Erica P A; Wouters, Emiel F M; Schalkwijk, Casper G

    2016-12-01

    Age-related, non-communicable chronic inflammatory diseases represent the major 21st century health problem. Especially in Western countries, the prevalence of non-communicable diseases like chronic obstructive pulmonary disease, cardiovascular disease, type 2 diabetes and osteoporosis are exponentially rising as the population ages. These diseases are determined by common risk factors and share an age-related onset. The affected organs display evidence of accelerated ageing, and are hallmarked by chronic inflammation and oxidative stress. The receptor for advanced glycation end products (RAGE) has been implicated in a number of inflammatory diseases and plays a central role in amplifying inflammatory responses. Advanced glycation end product (AGE) formation and accumulation is accelerated under these conditions. Advanced glycation end products are not only linked to RAGE signaling and inflammation, but to various hallmarks of the ageing process. In addition to these biological functions, circulating levels of the soluble form of RAGE and of advanced glycation end products are candidate biomarkers for many age-related inflammatory diseases. The purpose of this review is to provide an overview of the mechanistic connections between RAGE and advanced glycation end products and the processes of inflammation and ageing. Furthermore, through the presented overview of AGE-RAGE alterations that have been described in clinical studies in chronic obstructive pulmonary disease, cardiovascular disease, type 2 diabetes and osteoporosis, and insight obtained from mechanistic in vitro and animal studies, it can be concluded that these AGE-RAGE disturbances are a common contributing factor to the inflammatory state and pathogenesis of these various conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Autophagy Inhibits the Accumulation of Advanced Glycation End Products by Promoting Lysosomal Biogenesis and Function in the Kidney Proximal Tubules.

    Science.gov (United States)

    Takahashi, Atsushi; Takabatake, Yoshitsugu; Kimura, Tomonori; Maejima, Ikuko; Namba, Tomoko; Yamamoto, Takeshi; Matsuda, Jun; Minami, Satoshi; Kaimori, Jun-Ya; Matsui, Isao; Matsusaka, Taiji; Niimura, Fumio; Yoshimori, Tamotsu; Isaka, Yoshitaka

    2017-05-01

    Advanced glycation end products (AGEs) are involved in the progression of diabetic nephropathy. AGEs filtered by glomeruli or delivered from the circulation are endocytosed and degraded in the lysosomes of kidney proximal tubular epithelial cells (PTECs). Autophagy is a highly conserved degradation system that regulates intracellular homeostasis by engulfing cytoplasmic components. We have recently demonstrated that autophagic degradation of damaged lysosomes is indispensable for cellular homeostasis in some settings. In this study, we tested the hypothesis that autophagy could contribute to the degradation of AGEs in the diabetic kidney by modulating lysosomal biogenesis. Both a high-glucose and exogenous AGE overload gradually blunted autophagic flux in the cultured PTECs. AGE overload upregulated lysosomal biogenesis and function in vitro, which was inhibited in autophagy-deficient PTECs because of the impaired nuclear translocation of transcription factor EB. Consistently, streptozotocin-treated, PTEC-specific, autophagy-deficient mice failed to upregulate lysosomal biogenesis and exhibited the accumulation of AGEs in the glomeruli and renal vasculature as well as in the PTECs, along with worsened inflammation and fibrosis. These results indicate that autophagy contributes to the degradation of AGEs by the upregulation of lysosomal biogenesis and function in diabetic nephropathy. Strategies aimed at promoting lysosomal function hold promise for treating diabetic nephropathy. © 2017 by the American Diabetes Association.

  12. Regulation of Receptor for Advanced Glycation End Products (RAGE) Ectodomain Shedding and Its Role in Cell Function*

    Science.gov (United States)

    Braley, Alex; Kwak, Taekyoung; Jules, Joel; Harja, Evis; Landgraf, Ralf; Hudson, Barry I.

    2016-01-01

    The receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor that can undergo proteolysis at the cell surface to release a soluble ectodomain. Here we observed that ectodomain shedding of RAGE is critical for its role in regulating signaling and cellular function. Ectodomain shedding of both human and mouse RAGE was dependent on ADAM10 activity and induced with chemical activators of shedding (ionomycin, phorbol 12-myristate 13-acetate, and 4-aminophenylmercuric acetate) and endogenous stimuli (serum and RAGE ligands). Ectopic expression of the splice variant of RAGE (RAGE splice variant 4), which is resistant to ectodomain shedding, inhibited RAGE ligand dependent cell signaling, actin cytoskeleton reorganization, cell spreading, and cell migration. We found that blockade of RAGE ligand signaling with soluble RAGE or inhibitors of MAPK or PI3K blocked RAGE-dependent cell migration but did not affect RAGE splice variant 4 cell migration. We finally demonstrated that RAGE function is dependent on secretase activity as ADAM10 and γ-secretase inhibitors blocked RAGE ligand-mediated cell migration. Together, our data suggest that proteolysis of RAGE is critical to mediate signaling and cell function and may therefore emerge as a novel therapeutic target for RAGE-dependent disease states. PMID:27022018

  13. Modeling the Interaction between Quinolinate and the Receptor for Advanced Glycation End Products (RAGE): Relevance for Early Neuropathological Processes

    Science.gov (United States)

    Serratos, Iris N.; Castellanos, Pilar; Pastor, Nina; Millán-Pacheco, César; Rembao, Daniel; Pérez-Montfort, Ruy; Cabrera, Nallely; Reyes-Espinosa, Francisco; Díaz-Garrido, Paulina; López-Macay, Ambar; Martínez-Flores, Karina; López-Reyes, Alberto; Sánchez-García, Aurora; Cuevas, Elvis; Santamaria, Abel

    2015-01-01

    The receptor for advanced glycation end products (RAGE) is a pattern-recognition receptor involved in neurodegenerative and inflammatory disorders. RAGE induces cellular signaling upon binding to a variety of ligands. Evidence suggests that RAGE up-regulation is involved in quinolinate (QUIN)-induced toxicity. We investigated the QUIN-induced toxic events associated with early noxious responses, which might be linked to signaling cascades leading to cell death. The extent of early cellular damage caused by this receptor in the rat striatum was characterized by image processing methods. To document the direct interaction between QUIN and RAGE, we determined the binding constant (Kb) of RAGE (VC1 domain) with QUIN through a fluorescence assay. We modeled possible binding sites of QUIN to the VC1 domain for both rat and human RAGE. QUIN was found to bind at multiple sites to the VC1 dimer, each leading to particular mechanistic scenarios for the signaling evoked by QUIN binding, some of which directly alter RAGE oligomerization. This work contributes to the understanding of the phenomenon of RAGE-QUIN recognition, leading to the modulation of RAGE function. PMID:25757085

  14. Regulation of Receptor for Advanced Glycation End Products (RAGE) Ectodomain Shedding and Its Role in Cell Function.

    Science.gov (United States)

    Braley, Alex; Kwak, Taekyoung; Jules, Joel; Harja, Evis; Landgraf, Ralf; Hudson, Barry I

    2016-06-03

    The receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor that can undergo proteolysis at the cell surface to release a soluble ectodomain. Here we observed that ectodomain shedding of RAGE is critical for its role in regulating signaling and cellular function. Ectodomain shedding of both human and mouse RAGE was dependent on ADAM10 activity and induced with chemical activators of shedding (ionomycin, phorbol 12-myristate 13-acetate, and 4-aminophenylmercuric acetate) and endogenous stimuli (serum and RAGE ligands). Ectopic expression of the splice variant of RAGE (RAGE splice variant 4), which is resistant to ectodomain shedding, inhibited RAGE ligand dependent cell signaling, actin cytoskeleton reorganization, cell spreading, and cell migration. We found that blockade of RAGE ligand signaling with soluble RAGE or inhibitors of MAPK or PI3K blocked RAGE-dependent cell migration but did not affect RAGE splice variant 4 cell migration. We finally demonstrated that RAGE function is dependent on secretase activity as ADAM10 and γ-secretase inhibitors blocked RAGE ligand-mediated cell migration. Together, our data suggest that proteolysis of RAGE is critical to mediate signaling and cell function and may therefore emerge as a novel therapeutic target for RAGE-dependent disease states. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    International Nuclear Information System (INIS)

    Li, Guofeng; Xu, Jingren; Li, Zengchun

    2012-01-01

    Highlights: ► RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. ► RAGE overexpression decreases Wnt/β-catenin signaling. ► RAGE overexpression decreases ERK and PI3K signaling. ► Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. ► Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  16. Receptor for advanced glycation end products (RAGE) and its ligand, amphoterin are overexpressed and associated with prostate cancer development.

    Science.gov (United States)

    Ishiguro, Hitoshi; Nakaigawa, Noboru; Miyoshi, Yasuhide; Fujinami, Kiyoshi; Kubota, Yoshinobu; Uemura, Hiroji

    2005-06-15

    Advanced glycation end products (AGE) are produced with normal aging. Recently, some reports indicated that the interaction between AGE and the cognate receptor (RAGE) has a role in cancer dependent. We investigated RAGE and amphoterin mRNA expression in prostate cancer cell lines (DU145, PC-3, and LNCaP cells), hormone-refractory prostate cancer tissues, and paired untreated primary prostate cancer and normal prostate (including benign prostatic hypertrophy (BPH)) tissues using real-time quantitative PCR. Moreover, to confirm the AGE-RAGE interaction in prostate cancer, DU145 cells stimulated with AGE-bovine serum albumin (AGE-BSA) were examined by in vitro matrigel assay, cell viability assay, MTT assay, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot. DU145 cells, a hormone-independent prostate cancer cell line, showed the highest RAGE mRNA expression. Amphoterin mRNA was expressed in all three cell lines. In prostate tissues, untreated prostate cancer tissue and hormone-refractory prostate cancer tissue showed higher RAGE and amphoterin mRNA expression than normal prostate tissue. The AGE-RAGE interaction induced the invasion and growth in DU145 cells stimulated with AGE-BSA. The AGE-RAGE interaction is important in prostate cancer development, and inhibition of this interaction has potential as a new molecular target for cancer therapy or prevention.

  17. Early plasma soluble receptor for advanced glycation end-product levels are associated with bronchiolitis obliterans syndrome.

    Science.gov (United States)

    Shah, R J; Bellamy, S L; Lee, J C; Cantu, E; Diamond, J M; Mangalmurti, N; Kawut, S M; Ware, L B; Christie, J D

    2013-03-01

    Early epithelial injury after lung transplantation may contribute to development of bronchiolitis obliterans syndrome (BOS). We evaluated the relationship between early postoperative soluble receptor for advanced glycation end-product (sRAGE) levels, a marker of type I alveolar cell injury and BOS. We performed a cohort study of 106 lung transplant recipients between 2002 and 2006 at the University of Pennsylvania with follow-up through 2010. Plasma sRAGE was measured 6 and 24 h after transplantation. Cox proportional hazards models were used to evaluate the association between sRAGE and time to BOS, defined according to ISHLT guidelines. Sixty (57%) subjects developed BOS. The average time to BOS was 3.4 years. sRAGE levels measured at 6 h (HR per SD of sRAGE: 1.69, 95% CI: 1.11, 2.57, p = 0.02) and 24 h (HR per SD of sRAGE: 1.74, 95% CI: 1.14, 2.65, p = 0.01) were associated with an increased hazard of BOS. Multivariable Cox regression indicated this relationship was independent of potential confounders. Elevated plasma sRAGE levels measured in the immediate postoperative period are associated with the development of BOS. Early epithelial injury after transplantation may contribute to the development of fibrosis in BOS. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

  18. Advanced Glycation End Products Enhance Macrophages Polarization into M1 Phenotype through Activating RAGE/NF-κB Pathway

    Directory of Open Access Journals (Sweden)

    Xian Jin

    2015-01-01

    Full Text Available Atherosclerotic lesions are accelerated in patients with diabetes. M1 (classically activated in contrast to M2 alternatively activated macrophages play key roles in the progression of atherosclerosis. Since advanced glycation end products (AGEs are major pathogenic factors and active inflammation inducers in diabetes mellitus, this study assessed the effects of AGEs on macrophage polarization. The present study showed that AGEs significantly promoted macrophages to express IL-6 and TNF-α. M1 macrophage markers such as iNOS and surface markers including CD11c and CD86 were significantly upregulated while M2 macrophage markers such as Arg1 and CD206 remained unchanged after AGEs stimulation. AGEs significantly increased RAGE expression in macrophages and activated NF-κB pathway, and the aforementioned effects were partly abolished by administration of anti-RAGE antibody or NF-κB inhibitor PDTC. In conclusion, our results suggest that AGEs enhance macrophage differentiation into proinflammatory M1 phenotype at least partly via RAGE/NF-κB pathway activation.

  19. Advanced Glycation End Products Enhance Macrophages Polarization into M1 Phenotype through Activating RAGE/NF-κB Pathway

    Science.gov (United States)

    Jin, Xian; Yao, Tongqing; Zhou, Zhong'e; Zhu, Jian; Zhang, Song; Hu, Wei; Shen, Chengxing

    2015-01-01

    Atherosclerotic lesions are accelerated in patients with diabetes. M1 (classically activated in contrast to M2 alternatively activated) macrophages play key roles in the progression of atherosclerosis. Since advanced glycation end products (AGEs) are major pathogenic factors and active inflammation inducers in diabetes mellitus, this study assessed the effects of AGEs on macrophage polarization. The present study showed that AGEs significantly promoted macrophages to express IL-6 and TNF-α. M1 macrophage markers such as iNOS and surface markers including CD11c and CD86 were significantly upregulated while M2 macrophage markers such as Arg1 and CD206 remained unchanged after AGEs stimulation. AGEs significantly increased RAGE expression in macrophages and activated NF-κB pathway, and the aforementioned effects were partly abolished by administration of anti-RAGE antibody or NF-κB inhibitor PDTC. In conclusion, our results suggest that AGEs enhance macrophage differentiation into proinflammatory M1 phenotype at least partly via RAGE/NF-κB pathway activation. PMID:26114112

  20. Overexpression of Receptor for Advanced Glycation End Products and High-Mobility Group Box 1 in Human Dental Pulp Inflammation

    Science.gov (United States)

    Tancharoen, Salunya; Tengrungsun, Tassanee; Suddhasthira, Theeralaksna; Kikuchi, Kiyoshi; Vechvongvan, Nuttavun; Maruyama, Ikuro

    2014-01-01

    High mobility group box 1 (HMGB1), a nonhistone DNA-binding protein, is released into the extracellular space and promotes inflammation. HMGB1 binds to related cell signaling transduction receptors, including receptor for advanced glycation end products (RAGE), which actively participate in vascular and inflammatory diseases. The aim of this study was to examine whether RAGE and HMGB1 are involved in the pathogenesis of pulpitis and investigate the effect of Prevotella intermedia (P. intermedia) lipopolysaccharide (LPS) on RAGE and HMGB1 expression in odontoblast-like cells (OLC-1). RAGE and HMGB1 expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Upregulated expression of RAGE was observed in odontoblasts, stromal pulp fibroblasts-like cells, and endothelial-like cell lining human pulpitis tissue. Strong cytoplasmic HMGB1 immunoreactivity was noted in odontoblasts, whereas nuclear HMGB1 immunoreactivity was seen in stromal pulp fibroblasts-like cells in human pulpitis tissue. LPS stimulated OLC-1 cells produced HMGB1 in a dose-dependent manner through RAGE. HMGB1 translocation towards the cytoplasm and secretion from OLC-1 in response to LPS was inhibited by TPCA-1, an inhibitor of NF-κB activation. These findings suggest that RAGE and HMGB1 play an important role in the pulpal immune response to oral bacterial infection. PMID:25114379

  1. Overexpression of Receptor for Advanced Glycation End Products and High-Mobility Group Box 1 in Human Dental Pulp Inflammation

    Directory of Open Access Journals (Sweden)

    Salunya Tancharoen

    2014-01-01

    Full Text Available High mobility group box 1 (HMGB1, a nonhistone DNA-binding protein, is released into the extracellular space and promotes inflammation. HMGB1 binds to related cell signaling transduction receptors, including receptor for advanced glycation end products (RAGE, which actively participate in vascular and inflammatory diseases. The aim of this study was to examine whether RAGE and HMGB1 are involved in the pathogenesis of pulpitis and investigate the effect of Prevotella intermedia (P. intermedia lipopolysaccharide (LPS on RAGE and HMGB1 expression in odontoblast-like cells (OLC-1. RAGE and HMGB1 expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. Upregulated expression of RAGE was observed in odontoblasts, stromal pulp fibroblasts-like cells, and endothelial-like cell lining human pulpitis tissue. Strong cytoplasmic HMGB1 immunoreactivity was noted in odontoblasts, whereas nuclear HMGB1 immunoreactivity was seen in stromal pulp fibroblasts-like cells in human pulpitis tissue. LPS stimulated OLC-1 cells produced HMGB1 in a dose-dependent manner through RAGE. HMGB1 translocation towards the cytoplasm and secretion from OLC-1 in response to LPS was inhibited by TPCA-1, an inhibitor of NF-κB activation. These findings suggest that RAGE and HMGB1 play an important role in the pulpal immune response to oral bacterial infection.

  2. Comprehensive analyses of how tubule occlusion and advanced glycation end-products diminish strength of aged dentin

    Science.gov (United States)

    Shinno, Yuko; Ishimoto, Takuya; Saito, Mitsuru; Uemura, Reo; Arino, Masumi; Marumo, Keishi; Nakano, Takayoshi; Hayashi, Mikako

    2016-01-01

    In clinical dentistry, since fracture is a major cause of tooth loss, better understanding of mechanical properties of teeth structures is important. Dentin, the major hard tissue of teeth, has similar composition to bone. In this study, we investigated the mechanical properties of human dentin not only in terms of mineral density but also using structural and quality parameters as recently accepted in evaluating bone strength. Aged crown and root dentin (age ≥ 40) exhibited significantly lower flexural strength and toughness than young dentin (age alignment of the c-axis in hydroxyapatite exhibited high fracture strength, possibly because the aligned apatite along the collagen fibrils may reinforce the intertubular dentin. Aged dentin, showing a high advanced glycation end-products (AGEs) level in its collagen, recorded low flexural strength. We first comprehensively identified significant factors, which affected the inferior mechanical properties of aged dentin. The low mechanical strength of aged dentin is caused by the high mineral density resulting from occlusion of dentinal tubules and accumulation of AGEs in dentin collagen.

  3. Advanced glycation end-products produced systemically and by macrophages: A common contributor to inflammation and degenerative diseases.

    Science.gov (United States)

    Byun, Kyunghee; Yoo, YongCheol; Son, Myeongjoo; Lee, Jaesuk; Jeong, Goo-Bo; Park, Young Mok; Salekdeh, Ghasem Hosseini; Lee, Bonghee

    2017-09-01

    Advanced glycation end products (AGEs) and their receptor have been implicated in the progressions of many intractable diseases, such as diabetes and atherosclerosis, and are also critical for pathologic changes in chronic degenerative diseases, such as Alzheimer's disease, Parkinson's disease, and alcoholic brain damage. Recently activated macrophages were found to be a source of AGEs, and the most abundant form of AGEs, AGE-albumin excreted by macrophages has been implicated in these diseases and to act through common pathways. AGEs inhibition has been shown to prevent the pathogenesis of AGEs-related diseases in human, and therapeutic advances have resulted in several agents that prevent their adverse effects. Recently, anti-inflammatory molecules that inhibit AGEs have been shown to be good candidates for ameliorating diabetic complications as well as degenerative diseases. This review was undertaken to present, discuss, and clarify current understanding regarding AGEs formation in association with macrophages, different diseases, therapeutic and diagnostic strategy and links with RAGE inhibition. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Current perspectives on the health risks associated with the consumption of advanced glycation end products: recommendations for dietary management

    Directory of Open Access Journals (Sweden)

    Palimeri S

    2015-09-01

    Full Text Available Sotiria Palimeri,* Eleni Palioura,* Evanthia Diamanti-KandarakisEndocrine Unit, Medical School University of Athens, Athens, Greece*These authors contributed equally to this workAbstract: Advanced glycation end products (AGEs constitute a complex group of compounds produced endogenously during the aging process and under conditions of hyperglycemia and oxidative stress. AGEs also have an emerging exogenous origin. Cigarette smoke and diet are the two main exogenous sources of AGEs (glycotoxins. Modern Western diets are rich in AGEs which have been implicated in the pathogenesis of several metabolic and degenerative disorders. Accumulating evidence underlies the beneficial effect of the dietary restriction of AGEs not only in animal studies but also in patients with diabetic complications and metabolic diseases. This article reviews the evidence linking dietary glycotoxins to several disorders from diabetic complications and renal failure to liver dysfunction, female reproduction, eye and cognitive disorders as well as cancer. Furthermore, strategies for AGE reduction are discussed with a focus on dietary modification.Keywords: AGEs, dietary glycotoxins, dietary restriction, PCOS, MSR-1, RAGE

  5. An Emerging Role of Glucagon-Like Peptide-1 in Preventing Advanced-Glycation-End-Product-Mediated Damages in Diabetes

    Directory of Open Access Journals (Sweden)

    Alessandra Puddu

    2013-01-01

    Full Text Available Glucagon-like peptide-1 (GLP-1 is a gut hormone produced in the intestinal epithelial endocrine L cells by differential processing of the proglucagon gene. Released in response to the nutrient ingestion, GLP-1 plays an important role in maintaining glucose homeostasis. GLP-1 has been shown to regulate blood glucose levels by stimulating glucose-dependent insulin secretion and inhibiting glucagon secretion, gastric emptying, and food intake. These antidiabetic activities highlight GLP-1 as a potential therapeutic molecule in the clinical management of type 2 diabetes, (a disease characterized by progressive decline of beta-cell function and mass, increased insulin resistance, and final hyperglycemia. Since chronic hyperglycemia contributed to the acceleration of the formation of Advanced Glycation End-Products (AGEs, a heterogeneous group of compounds derived from the nonenzymatic reaction of reducing sugars with free amino groups of proteins implicated in vascular diabetic complications, the administration of GLP-1 might directly counteract diabetes pathophysiological processes (such as pancreatic β-cell dysfunction. This paper outlines evidence on the protective role of GLP-1 in preventing the deleterious effects mediated by AGEs in type 2 diabetes.

  6. Plasma Levels of Soluble Receptor for Advanced Glycation End Products and Coronary Atherosclerosis: Possible Correlation with Clinical Presentation

    Directory of Open Access Journals (Sweden)

    Colomba Falcone

    2013-01-01

    Full Text Available Receptor for Advanced Glycation End-products (RAGE is a multi-ligand receptor ubiquitous present on epithelial, neuronal, vascular and inflammatory cells, usually expressed at low levels in homeostasis and to increased degrees at sites of stress or injury. The aim of the present study was to evaluate sRAGE plasma levels in patients with Acute Coronary Syndrome (ACS and to assess its diagnostic efficacy in identification of patients with acute events. Plasma levels of sRAGE were determined in 860 patients with Coronary Artery Disease (CAD: 530 patients presented stable angina and 330 were observed during acute ischemic event (147 with unstable angina and 183 with myocardial infarction. sRAGE plasma levels were significantly lower in patients with ACS than in patients with stable angina: [median 584 pg/mL (IQR: 266–851 pg/mL in MI patients, median 769 pg/mL (IQR: 394–987 pg/mL in patients with unstable angina, median 834 pg/mL (IQR 630–1005 pg/mL in patients with stable angina; P<0.001]. sRAGE levels did not differ among ACS patients stratified by the extent of coronary artery disease. In conclusion, this study confirm the role of sRAGE in activation and progression of inflammatory process and suggests the possibility that sRAGE can be considered an indicator of destabilization of vulnerable plaque.

  7. Dietary Advanced Glycation End Products and Risk Factors for Chronic Disease: A Systematic Review of Randomised Controlled Trials

    Directory of Open Access Journals (Sweden)

    Rachel E. Clarke

    2016-03-01

    Full Text Available Dietary advanced glycation end-products (AGEs form during heating and processing of food products and are widely prevalent in the modern Western diet. Recent systematic reviews indicate that consumption of dietary AGEs may promote inflammation, oxidative stress and insulin resistance. Experimental evidence indicates that dietary AGEs may also induce renal damage, however, this outcome has not been considered in previous systematic reviews. The purpose of this review was to examine the effect of consumption of a high AGE diet on biomarkers of chronic disease, including chronic kidney disease (CKD, in human randomized controlled trials (RCTs. Six databases (SCOPUS, CINHAL, EMBASE, Medline, Biological abstracts and Web of Science were searched for randomised controlled dietary trials that compared high AGE intake to low AGE intake in adults with and without obesity, diabetes or CKD. Twelve dietary AGE interventions were identified with a total of 293 participants. A high AGE diet increased circulating tumour necrosis factor-alpha and AGEs in all populations. A high AGE diet increased 8-isoprostanes in healthy adults, and vascular cell adhesion molecule-1 (VCAM-1 in patients with diabetes. Markers of CKD were not widely assessed. The evidence presented indicates that a high AGE diet may contribute to risk factors associated with chronic disease, such as inflammation and oxidative stress, however, due to a lack of high quality randomised trials, more research is required.

  8. Association of advanced glycation end products, evaluated by skin autofluorescence, with lifestyle habits in a general Japanese population.

    Science.gov (United States)

    Isami, Fumiyuki; West, Brett J; Nakajima, Sanae; Yamagishi, Sho-Ichi

    2018-03-01

    Objective Accumulation of advanced glycation end products (AGEs) occurs during normal aging but markedly accelerates in people with diabetes. AGEs may play a role in various age-related disorders. Several studies have demonstrated that skin autofluorescence (SAF) reflects accumulated tissue levels of AGEs. However, very few studies have investigated SAF in the general population. The purpose of the present study was to more thoroughly evaluate the potential association among SAF, chronological age, and lifestyle habits in the general population. Methods A large cross-sectional survey of 10,946 Japanese volunteers aged 20 to 79 years was conducted. Volunteers completed a self-administered questionnaire and underwent SAF measurement on their dominant forearms. The associations of SAF with age and lifestyle habits were analyzed using a multiple stepwise regression analysis. Results Age was independently correlated with SAF. Lifestyle habits such as physical activity, nonsmoking, adequate sleep, low mental stress level, eating breakfast, and abstaining from sugary food were each independently associated with lower SAF. Conclusions SAF was associated with age and healthy lifestyle habits in this general Japanese population. The present study suggests that SAF measurement is a convenient tool for evaluating habitual lifestyle behaviors and may have potential for preventative health education.

  9. Acute Exposure to a Precursor of Advanced Glycation End Products Induces a Dual Effect on the Rat Pancreatic Islet Function

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    Ghada Elmhiri

    2014-01-01

    Full Text Available Aim. Chronic diseases are the leading cause of death worldwide. Advanced glycation end products, known as AGEs, are a major risk factor for diabetes onset and maintenance. Methylglyoxal (MG, a highly reactive metabolite of glucose, is a precursor for the generation of endogenous AGEs. Methods. In this current study we incubated in vitro pancreatic islets from adult rats in absence or presence of MG (10 μmol/l with different concentrations of glucose and different metabolic components (acetylcholine, epinephrine, potassium, forskolin, and leucine. Results. Different effects of MG on insulin secretion were evidenced. In basal glucose stimulation (5.6 mM, MG induced a significant (P<0.05 increase of insulin secretion. By contrast, in higher glucose concentrations (8.3 mM and 16.7 mM, MG significantly inhibited insulin secretion (P<0.05. In the presence of potassium, forskolin, and epinephrine, MG enhanced insulin secretion (P<0.05, while when it was incubated with acetylcholine and leucine, MG resulted in a decrease of insulin secretion (P<0.05. Conclusion. We suggest that MG modulates the secretion activity of beta-cell depending on its level of stimulation by other metabolic factors. These results provide insights on a dual acute effect of MG on the pancreatic cells.

  10. The effect of an insulin releasing agent, BTS 67582, on advanced glycation end product formation in vitro.

    Science.gov (United States)

    Simpson, A E; Jones, R B

    1999-01-01

    BTS 67582 (1,1-dimethyl-2-(2-morpholinophenyl) guanidine fumarate) is an insulin-releasing agent currently in phase II clinical trials. Its effect on advanced glycation end product (AGE) formation was measured in the BSA/D-glucose and L-lysine/glucose-6-phosphate assay systems and Amadori product formation was measured in the BSA/D-glucose assay system, following a 3 week incubation period. In the BSA/D-glucose assay system, 200 mM BTS 67582 caused an approximate 70% inhibition in AGE formation (pBTS 67582 and 200 mM aminoguanidine-HCl retarded Amadori product formation by 88% (pBTS 67582 at 20 mM and 2 mM was shown to inhibit Amadori product formation by 67% and 57%, respectively, (pBTS 67582 and 200 mM aminoguanidine-HCl were shown to inhibit AGE formation by about 70% and 96% (p<0.001), respectively. Tolbutamide (200 microM) and glibenclamide (100 microM) had no significant effect on AGE formation.

  11. Receptor for advanced glycation end products inhibits proliferation in osteoblast through suppression of Wnt, PI3K and ERK signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guofeng [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Xu, Jingren [Department of Traditional Chinese Orthopaedics, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China); Li, Zengchun, E-mail: lizc.2007@yahoo.com.cn [Department of Emergency Surgery, East Hospital, Tongji University School of Medicine, Shanghai 200120 (China)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer RAGE overexpression suppresses cell proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer RAGE overexpression decreases Wnt/{beta}-catenin signaling. Black-Right-Pointing-Pointer RAGE overexpression decreases ERK and PI3K signaling. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes PI3K signaling restored by RAGE blockade. Black-Right-Pointing-Pointer Inhibition of Wnt signaling abolishes ERK signaling restored by RAGE blockade. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a crucial role in bone metabolism. However, the role of RAGE in the control of osteoblast proliferation is not yet evaluated. In the present study, we demonstrate that RAGE overexpression inhibits osteoblast proliferation in vitro. The negative regulation of RAGE on cell proliferation results from suppression of Wnt, PI3K and ERK signaling, and is restored by RAGE neutralizing antibody. Prevention of Wnt signaling using Sfrp1 or DKK1 rescues RAGE-decreased PI3K and ERK signaling and cell proliferation, indicating that the altered cell growth in RAGE overexpressing cells is in part secondary to alterations in Wnt signaling. Consistently, RAGE overexpression inhibits the expression of Wnt targets cyclin D1 and c-myc, which is partially reversed by RAGE blockade. Overall, these results suggest that RAGE inhibits osteoblast proliferation via suppression of Wnt, PI3K and ERK signaling, which provides novel mechanisms by which RAGE regulates osteoblast growth.

  12. Temperature effect on formation of advanced glycation end products in infant formula milk powder

    DEFF Research Database (Denmark)

    Zhu, Ru-Gang; Cheng, Hong; Li, Li

    2018-01-01

    for their formation of 28 kJ mol1 following crystallisation of the powder using an indirect ELISA method for determination of AGE. This energy of activation was larger than the energies of activation of 6.5 and 5.7 kJ mol1, as found for formation of the Strecker aldehydes 2- and 3-methyl butanal, respectively....... Formation of AGE occurred in the browning reaction sequence later than Strecker degradation. At 25 C less than 0.1 ng mg1 AGE was formed in storage for 2 months. Toxicity could only be detected for storage for longer than 1 month at 65 C, where AGE formation is approximately 2 ng mg1....

  13. Growth arrest specific 2-like protein 1 expression is upregulated in podocytes through advanced glycation end-products.

    Science.gov (United States)

    Liebisch, Marita; Bondeva, Tzvetanka; Franke, Sybille; Hause, Stephan; Wolf, Gunter

    2017-04-01

    Growth arrest specific 2-like protein 1 (GAS2L1) protein is a member of the GAS2 family of proteins, known to regulate apoptosis and cellular cytoskeleton reorganization in different cells. Recently we identified that Gas2l1 gene expression in podocytes is influenced by advanced glycation end product-bovine serum albumin(AGE-BSA). The study was performed employing cultured podocytes and diabetic ( db/db ) mice, a model of type 2 diabetes. Akbuminuria as wellas urinary neutrophil gelatinase-associated lipocalin (NGAL) excretion as measured with specific ELISAs. Gene expression was analysed via semiquantitative and real-time polymerase chain reaction. The protein levels were determined by western blotting and immunostaining. We found that the Gas2l1 α isoform is expressed in podocytes. Treatment with AGE-BSA induced Gas2l1 α and Gas2 mRNA levels compared with controls incubated with non-glycated control BSA (Co-BSA). Moreover, application of the recombinant soluble receptor of AGEs (sRAGE), a competitor of cellular RAGE, reversed the AGE-BSA effect. Interestingly, AGE-BSA also increased the protein levels of GAS2L1α in a RAGE-dependent manner, but did not affect the GAS2 expression. Periodic acid-Schiff staining and albuminuria as well as urinary NGAL excretion revealed that db/db mice progressively developed diabetic nephropathy with renal accumulation of N ε -carboxy-methyl-lysine (immunohistochemistry, western blots). Analyses of GAS2L1α and GAS2 proteins in diabetic mice revealed that both were significantly elevated relative to their non-diabetic littermates. In addition, GAS2L1α and GAS2 proteins positively correlated with the accumulation of AGEs in the blood plasma of diabetic mice and the administration of sRAGE in diabetic mice reduced the glomerular expression of both proteins. We show for the first time that the protein expression of GAS2L1α in vitro and in vivo is regulated by the AGE-RAGE axis. The suppression of AGE ligation with their RAGE in

  14. Inhibitory Effects of Siegesbeckia orientalis Extracts on Advanced Glycation End Product Formation and Key Enzymes Related to Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Wei-Chin Hung

    2017-10-01

    Full Text Available Metabolic syndrome typically includes Type 2 diabetes associated with hyperglycemia, central obesity, dyslipidemia and hypertension. It is highly related to oxidative stress, formation of advanced glycated end products (AGEs and key enzymes, such as carbohydrate digesting enzymes like pancreatic α-amylase and intestinal α-glucosidase, pancreatic lipase and angiotensin I-converting enzyme (ACE. This study used an in vitro approach to assess the potential of four extracts of Siegesbeckia orientalis linne on key enzymes relevant to metabolic syndrome. In this research, S. orientailis was firstly extracted by ethanol. The ethanol extract (SE was then partitioned sequentially with hexane, ethyl acetate and methanol, and these extracts were named SE-Hex, SE-EA and SE-MeOH, respectively. The experimental results showed that SE-EA had the highest total phenolic content (TPC, 76.9 ± 1.8 mg/g and the total flavonoids content (TFC, 5.3 ± 0.3 mg/g. This extract exhibited the most significant antioxidant activities, including DPPH radical-scavenging capacity (IC50 = 161.8 ± 2.4 μg/mL, ABTS radical-scavenging capacity (IC50 = 13.9 ± 1.5 μg/mL and reducing power. For anti-glycation activities, SE-EA showed the best results in the inhibition of AGEs, as well as inhibitory activities against α-glucosidase (IC50 = 362.3 ± 9.2 μg/mL and α-amylase (IC50 = 119.0 ± 17.7 μg/mL. For anti-obesity activities, SE-EA indicated the highest suppression effect on pancreatic lipase (IC50 = 3.67 ± 0.52 mg/mL. Finally, for anti-hypertension activity, SE-EA also demonstrated the strongest inhibitory activity on ACE (IC50 = 626.6 ± 15.0 μg/mL. Close relationships were observed among the parameters of TPC, antioxidant activities, inhibitory activities on α-amylase, α-glucosidase, lipase and ACE (R > 0.9. Moderate correlations were found among the parameters of TFC, antioxidant activities, and suppression of dicarbonyl compounds formation (R = 0.5–0.9. Taken

  15. Generation of Soluble Advanced Glycation End Products Receptor (sRAGE)-Binding Ligands during Extensive Heat Treatment of Whey Protein/Lactose Mixtures Is Dependent on Glycation and Aggregation

    NARCIS (Netherlands)

    Liu, Fahui; Teodorowicz, Gosia; Wichers, Harry J.; Boekel, van Tiny; Hettinga, Kasper A.

    2016-01-01

    Heating of protein- and sugar-containing materials is considered the primary factor affecting the formation of advanced glycation end products (AGEs). This study aimed to investigate the influence of heating conditions, digestion, and aggregation on the binding capacity of AGEs to the soluble AGE

  16. Characterization of αX I-Domain Binding to Receptors for Advanced Glycation End Products (RAGE).

    Science.gov (United States)

    Buyannemekh, Dolgorsuren; Nham, Sang-Uk

    2017-05-31

    The β2 integrins are cell surface transmembrane proteins regulating leukocyte functions, such as adhesion and migration. Two members of β2 integrin, αMβ2 and αXβ2, share the leukocyte distribution profile and integrin αXβ2 is involved in antigen presentation in dendritic cells and transendothelial migration of monocytes and macrophages to atherosclerotic lesions. Receptor for advanced glycation end products (RAGE), a member of cell adhesion molecules, plays an important role in chronic inflammation and atherosclerosis. Although RAGE and αXβ2 play an important role in inflammatory response and the pathogenesis of atherosclerosis, the nature of their interaction and structure involved in the binding remain poorly defined. In this study, using I-domain as a ligand binding motif of αXβ2, we characterize the binding nature and the interacting moieties of αX I-domain and RAGE. Their binding requires divalent cations (Mg 2+ and Mn 2+ ) and shows an affinity on the sub-micro molar level: the dissociation constant of αX I-domains binding to RAGE being 0.49 μM. Furthermore, the αX I-domains recognize the V-domain, but not the C1 and C2-domains of RAGE. The acidic amino acid substitutions on the ligand binding site of αX I-domain significantly reduce the I-domain binding activity to soluble RAGE and the alanine substitutions of basic amino acids on the flat surface of the V-domain prevent the V-domain binding to αX I-domain. In conclusion, the main mechanism of αX I-domain binding to RAGE is a charge interaction, in which the acidic moieties of αX I-domains, including E244, and D249, recognize the basic residues on the RAGE V-domain encompassing K39, K43, K44, R104, and K107.

  17. Effects of Prolyl Hydroxylase Inhibitor L-mimosine on Dental Pulp in the Presence of Advanced Glycation End Products.

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    Müller, Heinz-Dieter; Cvikl, Barbara; Janjić, Klara; Nürnberger, Sylvia; Moritz, Andreas; Gruber, Reinhard; Agis, Hermann

    2015-11-01

    Proangiogenic prolyl hydroxylase (PHD) inhibitors represent a novel approach to stimulate tissue regeneration. Diabetes mellitus involves the accumulation of advanced glycation end products (AGEs). Here we evaluated the impact of AGEs on the response of human pulp tissue to the PHD inhibitor L-mimosine (L-MIM) in monolayer cultures of dental pulp-derived cells (DPCs) and tooth slice organ cultures. In monolayer cultures, DPCs were incubated with L-MIM and AGEs. Viability was assessed based on formazan formation, live-dead staining, annexin V/propidium iodide, and trypan blue exclusion assay. Vascular endothelial growth factor (VEGF), interleukin (IL)-6, and IL-8 production was evaluated by quantitative polymerase chain reaction and immunoassays. Furthermore, expression levels of odontoblast markers were assessed, and alizarin red staining was performed. Tooth slice organ cultures were performed, and VEGF, IL-6, and IL8 levels in their supernatants were measured by immunoassays. Pulp tissue vitality and morphology were assessed by MTT assay and histology. In monolayer cultures of DPCs, L-MIM at nontoxic concentrations increased the production of VEGF and IL-8 in the presence of AGEs. Stimulation with L-MIM decreased alkaline phosphatase levels and matrix mineralization also in the presence of AGEs, whereas no significant changes in dentin matrix protein 1 and dentin sialophosphoprotein expression were observed. In tooth slice organ cultures, L-MIM increased VEGF but not IL-6 and IL-8 production in the presence of AGEs. The pulp tissue was vital, and no signs of apoptosis or necrosis were observed. Overall, in the presence of AGEs, L-MIM increases the proangiogenic capacity, but decreases alkaline phosphatase expression and matrix mineralization. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Blockade by phosphorothioate aptamers of advanced glycation end products-induced damage in cultured pericytes and endothelial cells.

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    Higashimoto, Yuichiro; Matsui, Takanori; Nishino, Yuri; Taira, Junichi; Inoue, Hiroyoshi; Takeuchi, Masayoshi; Yamagishi, Sho-Ichi

    2013-11-01

    Advanced glycation end products (AGEs) not only inhibit DNA synthesis of retinal pericytes, but also elicit vascular hyperpermeability, pathological angiogenesis, and thrombogenic reactions by inducing vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) through the interaction with the receptor for AGEs (RAGE), thereby being involved in the pathogenesis of diabetic retinopathy. In this study, we screened novel phosphorothioate-modified aptamers directed against AGEs (AGEs-thioaptamers) using a combinatorial chemistry in vitro, and examined whether these aptamers could inhibit the AGE-induced damage in both retinal pericytes and human umbilical vein endothelial cells (HUVECs). We identified 11 AGEs-thioaptamers; among them, clones #4, #7s and #9s aptamers had higher binding affinity to AGEs-human serum albumin (HSA) than the others. Surface plasmon resonance analysis revealed that KD values of #4s, #7s and #9s were 0.63, 0.36, and 0.57nM, respectively. Furthermore, these 3 clones dose-dependently restored the decrease in DNA synthesis in AGE-exposed pericytes. AGEs significantly increased RAGE, VEGF and PAI-1 mRNA levels in HUVEC, all of which were completely blocked by the treatment with 20nM clone #4s aptamer. Quartz crystal microbalance analysis confirmed that #4s aptamer dose-dependently inhibited the binding of AGEs-HSA to RAGE. Our present study demonstrated that AGEs-thioaptamers could inhibit the harmful effects of AGEs in pericytes and HUVEC by suppressing the binding of AGEs to RAGE. Blockade by AGEs-thioaptamers of the AGEs-RAGE axis might be a novel therapeutic strategy for diabetic retinopathy. © 2013.

  19. Modulation of soluble receptor for advanced glycation end products by angiotensin-converting enzyme-1 inhibition in diabetic nephropathy.

    Science.gov (United States)

    Forbes, Josephine M; Thorpe, Suzanne R; Thallas-Bonke, Vicki; Pete, Josefa; Thomas, Merlin C; Deemer, Elizabeth R; Bassal, Sahar; El-Osta, Assam; Long, David M; Panagiotopoulos, Sianna; Jerums, George; Osicka, Tanya M; Cooper, Mark E

    2005-08-01

    Recent studies have identified that first-line renoprotective agents that interrupt the renin-angiotensin system not only reduce BP but also can attenuate advanced glycation end product (AGE) accumulation. This study used in vitro, preclinical, and human approaches to explore the potential effects of these agents on the modulation of the receptor for AGE (RAGE). Bovine aortic endothelial cells that were exposed to the angiotensin-converting enzyme inhibitor (ACEi) ramiprilat in the presence of high glucose demonstrated a significant increase in soluble RAGE (sRAGE) secreted into the medium. In streptozotocin-induced diabetic rats, ramipril treatment (ACEi) at 3 mg/L for 24 wk reduced the accumulation of skin collagen-linked carboxymethyllysine and pentosidine, as well as circulating and renal AGE. Renal gene upregulation of total RAGE (all three splice variants) was observed in ACEi-treated animals. There was a specific increase in the gene expression of the splice variant C-truncated RAGE (sRAGE). There were also increases in sRAGE protein identified within renal cells with ACEi treatment, which showed AGE-binding ability. This was associated with decreases in renal full-length RAGE protein from ACEi-treated rats. Decreases in plasma soluble RAGE that were significantly increased by ACEi treatment were also identified in diabetic rats. Similarly, there was a significant increase in plasma sRAGE in patients who had type 1 diabetes and were treated with the ACEi perindopril. Complexes between sRAGE and carboxymethyllysine were identified in human and rodent diabetic plasma. It is postulated that ACE inhibition reduces the accumulation of AGE in diabetes partly by increasing the production and secretion of sRAGE into plasma.

  20. Accumulation of carbonyls accelerates the formation of pentosidine, an advanced glycation end product: carbonyl stress in uremia.

    Science.gov (United States)

    Miyata, T; Ueda, Y; Yamada, Y; Izuhara, Y; Wada, T; Jadoul, M; Saito, A; Kurokawa, K; van Ypersele de Strihou, C

    1998-12-01

    Advanced glycation end product (AGE) formation is related to hyperglycemia in diabetes but not in uremia, because plasma AGE levels do not differ between diabetic and nondiabetic hemodialysis patients. The mechanism of this phenomenon remains elusive. Previously, it was suggested that elevation of AGE levels in uremia might result from the accumulation of unknown AGE precursors. The present study evaluates the in vitro generation of pentosidine, a well identified AGE structure. Plasma samples from healthy subjects and nondiabetic hemodialysis patients were incubated under air for several weeks. Pentosidine levels were determined at intervals by HPLC assay. Pentosidine rose to a much larger extent in uremic than in control plasma. Pentosidine yield, i.e., the change in pentosidine level between 0 and 4 wk divided by 28 d, averaged 0.172 nmol/ml per d in uremic versus 0.072 nmol/ml per d in control plasma (P aminoguanidine and OPB-9195, which inhibit the Maillard reaction, lowered pentosidine yield in both uremic and control plasma. When ultrafiltrated plasma was exposed to 2,4-dinitrophenylhydrazine, the yield of hydrazones, formed by interaction with carbonyl groups, was markedly higher in uremic than in control plasma. These observations strongly suggest that the pentosidine precursors accumulated in uremic plasma are carbonyl compounds. These precursors are unrelated to glucose or ascorbic acid, whose concentration is either normal or lowered in uremic plasma. They are also unrelated to 3-deoxyglucosone, a glucose-derived dicarbonyl compound whose level is raised in uremic plasma: Its addition to normal plasma fails to increase pentosidine yield. This study reports an elevated level of reactive carbonyl compounds ("carbonyl stress") in uremic plasma. Most have a lower than 5000 Da molecular weight and are thus partly removed by hemodialysis. Their effect on pentosidine generation can be inhibited by aminoguanidine or OPB-9195. Carbonyl stress might contribute to

  1. Hepatic microvascular dysfunction and increased advanced glycation end products are components of non-alcoholic fatty liver disease.

    Science.gov (United States)

    Pereira, Evelyn Nunes Goulart da Silva; Silvares, Raquel Rangel; Flores, Edgar Eduardo Ilaquita; Rodrigues, Karine Lino; Ramos, Isalira Peroba; da Silva, Igor José; Machado, Marcelo Pelajo; Miranda, Rosiane Aparecida; Pazos-Moura, Carmen Cabanelas; Gonçalves-de-Albuquerque, Cassiano F; Faria-Neto, Hugo Caire de Castro; Tibiriça, Eduardo; Daliry, Anissa

    2017-01-01

    This study aimed to investigate the pathophysiology of hepatic microcirculatory dysfunction in non-alcoholic fatty liver disease (NAFLD). In Wistar rats, NAFLD model was induced by 20 weeks of high-fat diet (HFD) feeding. Rolling and adhesion of leukocytes and tissue perfusion in hepatic microcirculation were examined using in vivo microscopic and laser speckle contrast imaging (LSCI), respectively. Oxidative stress and inflamatory parameters were analysed by TBARs, catalase enzyme activity, RT-PCR and ELISA. The participation of advanced glycation end-products (AGE) and its receptor RAGE was evaluated by the measurement of gene and protein expression of RAGE by RT-PCR and Western-blot, respectively and by liver and serum quantification of fluorescent AGEs. Wistar rats fed high-fat diet (HFD) showed increase in epididymal and abdominal fat content, systolic arterial blood pressure, fasting blood glucose levels, hepatic triglycerides and cholesterol, and impairment of glucose and insulin metabolisms. Liver histology confirmed the presence of steatosis and ultrasound analysis revealed increased liver size and parenchymal echogenicity in HFD-fed rats. HFD causes significant increases in leukocyte rolling and adhesion on hepatic microcirculation and decrease in liver microvascular blood flow. Liver tissue presented increase in oxidative stress and inflammtion. At 20 weeks, there was a significantly increase in AGE content in the liver and serum of HFD-fed rats and an increase in RAGE gene expression in the liver. The increase in liver AGE levels and microcirculatory disturbances could play a role in the pathogenesis of liver injury and are key components of NAFLD.

  2. The advanced glycation end product Nϵ-carboxymethyllysine and its precursor glyoxal increase serotonin release from Caco-2 cells.

    Science.gov (United States)

    Holik, Ann-Katrin; Lieder, Barbara; Kretschy, Nicole; Somoza, Mark M; Ley, Jakob P; Hans, Joachim; Somoza, Veronika

    2018-03-01

    Advanced glycation end products (AGEs), comprising a highly diverse class of Maillard reaction compounds formed in vivo and during heating processes of foods, have been described in the progression of several degenerative conditions such as Alzheimer's disease and diabetes mellitus. N ϵ -Carboxymethyllysine (CML) represents a well-characterized AGE, which is frequently encountered in a Western diet and is known to mediate its cellular effects through binding to the receptor for AGEs (RAGE). As very little is known about the impact of exogenous CML and its precursor, glyoxal, on intestinal cells, a genome-wide screening using a customized microarray was conducted in fully differentiated Caco-2 cells. After verification of gene regulation by qPCR, functional assays on fatty acid uptake, glucose uptake, and serotonin release were performed. While only treatment with glyoxal showed a slight impact on fatty acid uptake (P < 0.05), both compounds reduced glucose uptake significantly, leading to values of 81.3% ± 22.8% (500 μM CML, control set to 100%) and 68.3% ± 20.9% (0.3 μM glyoxal). Treatment with 500 μM CML or 0.3 μM glyoxal increased serotonin release (P < 0.05) to 236% ± 111% and 264% ± 66%, respectively. Co-incubation with the RAGE antagonist FPS-ZM1 reduced CML-induced serotonin release by 34%, suggesting a RAGE-mediated mechanism. Similarly, co-incubation with the SGLT-1 inhibitor phloridzin attenuated serotonin release after CML treatment by 32%, hinting at a connection between CML-stimulated serotonin release and glucose uptake. Future studies need to elucidate whether the CML/glyoxal-induced serotonin release in enterocytes might stimulate serotonin-mediated intestinal motility. © 2017 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.

  3. Advanced Glycation End-Products Induce Apoptosis of Vascular Smooth Muscle Cells: A Mechanism for Vascular Calcification

    Directory of Open Access Journals (Sweden)

    Sayo Koike

    2016-09-01

    Full Text Available Vascular calcification, especially medial artery calcification, is associated with cardiovascular death in patients with diabetes mellitus and chronic kidney disease (CKD. To determine the underlying mechanism of vascular calcification, we have demonstrated in our previous report that advanced glycation end-products (AGEs stimulated calcium deposition in vascular smooth muscle cells (VSMCs through excessive oxidative stress and phenotypic transition into osteoblastic cells. Since AGEs can induce apoptosis, in this study we investigated its role on VSMC apoptosis, focusing mainly on the underlying mechanisms. A rat VSMC line (A7r5 was cultured, and treated with glycolaldehyde-derived AGE-bovine serum albumin (AGE3-BSA. Apoptotic cells were identified by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining. To quantify apoptosis, an enzyme-linked immunosorbent assay (ELISA for histone-complexed DNA fragments was employed. Real-time PCR was performed to determine the mRNA levels. Treatment of A7r5 cells with AGE3-BSA from 100 µg/mL concentration markedly increased apoptosis, which was suppressed by Nox inhibitors. AGE3-BSA significantly increased the mRNA expression of NAD(PH oxidase components including Nox4 and p22phox, and these findings were confirmed by protein levels using immunofluorescence. Dihydroethidisum assay showed that compared with cBSA, AGE3-BSA increased reactive oxygen species level in A7r5 cells. Furthermore, AGE3-induced apoptosis was significantly inhibited by siRNA-mediated knockdown of Nox4 or p22phox. Double knockdown of Nox4 and p22phox showed a similar inhibitory effect on apoptosis as single gene silencing. Thus, our results demonstrated that NAD(PH oxidase-derived oxidative stress are involved in AGEs-induced apoptosis of VSMCs. These findings might be important to understand the pathogenesis of vascular calcification in diabetes and CKD.

  4. Measurement of urinary advanced glycation end-products (AGEs) using a fluorescence assay for metabolic syndrome-related screening tests.

    Science.gov (United States)

    Suehiro, Akira; Uchida, Kagehiro; Nakanishi, Mamoru; Wakabayashi, Ichiro

    2016-01-01

    The simple screening test of advanced glycation end-products (AGEs) has not been established yet. We aimed to clarify the usefulness of simple measurement of AGEs for screening tests. The subjects were healthy participants and patients with metabolic syndrome. Urine samples were diluted from 1:10 to 1:200 using phosphate-buffered saline, and the fluorescence intensity was measured at 440nm after excitation at 370nm in a 96-well microplate spectrophotometer. The obtained intensities were adjusted according to the urinary creatinine levels. In patients with metabolic syndrome, urinary AGE levels were significantly higher than in healthy individuals (median [range], 168.25 [82.51-1276.15] AU/g creatinine [n=37] versus 134.67 [37.86-776.31] AU/g creatinine [n=350], respectively; p=0.0066). We found significant positive correlations between urinary AGEs and systolic and diastolic blood pressures (Spearman's correlation r=0.119 [p=0.019] and r=0.128 [p=0.012], respectively). There was no significant correlation between estimated glomerular filtration rate and urinary AGEs (r=0.018 [p=0.744]), confirming that renal dysfunction did not influence results of urinary AGE measurements. When all of the participants in the study were classified into four groups according to the numbers of components of metabolic syndrome, we found a significant tendency (p=0.0127) for urinary AGE levels to be higher with the increasing number of metabolic syndrome components. These results suggested that measurement of urinary AGE levels may be useful for evaluating the risk of metabolic syndrome. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  5. Association between small fiber neuropathy and higher skin accumulation of advanced glycation end products in patients with type 1 diabetes.

    Science.gov (United States)

    Araszkiewicz, Aleksandra; Gandecka, Agnieszka; Nowicki, Michał; Uruska, Aleksandra; Malińska, Agnieszka; Kowalska, Katarzyna; Wierusz-Wysocka, Bogna; Zozulińska-Ziółkiewicz, Dorota

    2016-11-22

    INTRODUCTION Advanced glycation end products (AGEs) play a crucial role in the pathogenesis of diabetic peripheral neuropathy (DPN). OBJECTIVES The aim of the study was to assess the skin accumulation of AGEs in patients with long‑lasting type 1 diabetes in relation to the presence of DPN. PATIENTS AND METHODS We evaluated 178 patients with type 1 diabetes (99 men; age, 43 years [interquartile range [IQR], 34-54 years]; disease duration, 25 years [IQR, 18-31 years]). DPN was diagnosed if 2 or more of the following 5 abnormalities were present: symptoms of neuropathy, lack of ankle reflexes, and impaired sensation of touch, temperature, and/or vibration. PGP 9.5‑immunoreactive nerve fibers were counted to assess intraepidermal nerve fiber density (IENFD) in skin biopsy. The accumulation of AGEs in the skin was assessed on the basis of skin autofluorescence (AF).  RESULTS Patients with DPN (45%), compared with those without neuropathy, had higher skin AF (2.6 AU [IQR, 2.3-3.1 AU] vs 2.1 AU [IQR, 1.8-2.5 AU]; P skin AF and patients' age (Rs = 0.44; P skin AF and the estimated glomerular filtration rate (Rs = -0.26, P analysis, skin AF was independently associated with age (β = 0.45; P multivariate logistic regression, the presence of DPN was independently associated with skin AF (odds ratio, 4.16; 95% confidence interval, 1.88-9.20; P skin of patients with type 1 diabetes.

  6. Potential Inhibitory Effects of l-Carnitine Supplementation on Tissue Advanced Glycation End Products in Patients with Hemodialysis

    Science.gov (United States)

    Yamagishi, Sho-ichi; Sakai, Kazuko; Kaida, Yusuke; Adachi, Takeki; Ando, Ryotaro; Okuda, Seiya

    2013-01-01

    Abstract Background and Aims: Advanced glycation end products (AGEs) contribute to cardiovascular disease in patients with hemodialysis (HD). We have recently found that carnitine levels are inversely associated with skin AGE levels in HD patients. We examined whether l-carnitine supplementation reduced skin AGE levels in HD patients with carnitine deficiency. Methods: This was a single-center study. One hundred and two HD patients (total carnitine levels l-carnitine (900 mg/day) (n=51) or control (n=51). After 6 months, metabolic and inflammatory variables, including serum levels of carnitine, were measured. Skin AGE levels were determined by evaluating skin auto-fluorescence with an AGE-reader. Results: There were no significant differences of clinical variables at baseline between the control and l-carnitine therapy group. Thirty-two patients did not complete the assessment or treatment of the study. Oral l-carnitine supplementation for 6 months significantly increased low-density lipoprotein cholesterol (LDL-C), triglycerides, total, free, and acyl carnitine levels, while it decreased alanine transaminase, acyl/free carnitine ratio, β2-microglobulin, and skin AGE values. Change in total carnitine values from baseline (Δtotal carnitine) and Δfree carnitine were inversely associated with Δskin AGE levels in l-carnitine-treated patients (p=0.036 and p=0.016, respectively). In multiple regression analysis, Δfree carnitine was a sole independent determinant of Δskin AGEs (R2=0.178). Conclusions: The present study demonstrated that oral l-carnitine supplementation significantly decreased skin AGE levels in HD patients with carnitine deficiency. These observations suggest that supplementation of l-carnitine might be a novel therapeutic strategy for preventing the accumulation of tissue AGEs in carnitine-deficient patients with HD. PMID:23909402

  7. An advanced glycation end product (AGE)-receptor for AGEs (RAGE) axis restores adipogenic potential of senescent preadipocytes through modulation of p53 protein function.

    Science.gov (United States)

    Chen, Chih-Yu; Abell, Allison Martorano; Moon, Yang Soo; Kim, Kee-Hong

    2012-12-28

    The impaired adipogenic potential of senescent preadipocytes is a hallmark of adipose aging and aging-related adipose dysfunction. Although advanced glycation end products (AGEs) derived from both foods and endogenous nonenzymatic glycation and AGE-associated signaling pathways are known to play a key role in aging and its related diseases, the role of AGEs in adipose aging remains elusive. We show a novel pro-adipogenic function of AGEs in replicative senescent preadipocytes and mouse embryonic fibroblasts, as well as primary preadipocytes isolated from aged mice. Using glycated bovine serum albumin (BSA) as a model protein of AGEs, we found that glycated BSA restores the impaired adipogenic potential of senescent preadipocytes in vitro and ex vivo. However, glycated BSA showed no effect on adipogenesis in nonsenescent preadipocytes. The AGE-induced receptor for AGE (RAGE) expression is required for the pro-adipogenic function of AGEs in senescent preadipocytes. RAGE is required for impairment of p53 expression and p53 function in regulating p21 expression in senescent preadipocytes. We also observed a direct binding between RAGE and p53 in senescent preadipocytes. Taken together, our findings reveal a novel pro-adipogenic function of the AGE-RAGE axis in p53-regulated adipogenesis of senescent preadipocytes, providing new insights into aging-dependent adiposity by diet-driven and/or endogenous glycated proteins.

  8. Association of Advanced Glycation End Products with coronary Artery Calcification in Japanese Subjects with Type 2 Diabetes as Assessed by Skin Autofluorescence

    OpenAIRE

    Hangai, Mari; Takebe, Noriko; Honma, Hiroyuki; Sasaki, Atsumi; Chida, Ai; Nakano, Rieko; Togashi, Hirobumi; Nakagawa, Riyuki; Oda, Tomoyasu; Matsui, Mizue; Yashiro, Satoshi; Nagasawa, Kan; Kajiwara, Takashi; Takahashi, Kazuma; Takahashi, Yoshihiko

    2016-01-01

    Aim: Advanced glycation end products (AGE) are considered to be among the critical pathogenic factors involved in the progression of diabetic complications. Skin autofluorescence (AF), a noninvasive measurement of AGE accumulation, has been recognized as a useful and convenient marker for diabetic vascular diseases in Caucasians. This study aimed to evaluate the association of tissue AGE, assessed using skin AF, with coronary artery calcification in Japanese subjects with type 2 diabetes. Met...

  9. Diastolic dysfunction of aging is independent of myocardial structure but associated with plasma advanced glycation end-product levels.

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    Duncan J Campbell

    Full Text Available BACKGROUND: Heart failure is associated with abnormalities of myocardial structure, and plasma levels of the advanced glycation end-product (AGE N(ε-(carboxymethyllysine (CML correlate with the severity and prognosis of heart failure. Aging is associated with diastolic dysfunction and increased risk of heart failure, and we investigated the hypothesis that diastolic dysfunction of aging humans is associated with altered myocardial structure and plasma AGE levels. METHODS: We performed histological analysis of non-ischemic left ventricular myocardial biopsies and measured plasma levels of the AGEs CML and low molecular weight fluorophores (LMWFs in 26 men undergoing coronary artery bypass graft surgery who had transthoracic echocardiography before surgery. None had previous cardiac surgery, myocardial infarction, atrial fibrillation, or heart failure. RESULTS: The patients were aged 43-78 years and increasing age was associated with echocardiographic indices of diastolic dysfunction, with higher mitral Doppler flow velocity A wave (r = 0.50, P = 0.02, lower mitral E/A wave ratio (r = 0.64, P = 0.001, longer mitral valve deceleration time (r = 0.42, P = 0.03 and lower early diastolic peak velocity of the mitral septal annulus, e' (r = 0.55, P = 0.008. However, neither mitral E/A ratio nor mitral septal e' was correlated with myocardial total, interstitial or perivascular fibrosis (picrosirius red, immunostaining for collagens I and III, CML, and receptor for AGEs (RAGE, cardiomyocyte width, capillary length density, diffusion radius or arteriolar dimensions. Plasma AGE levels were not associated with age. However, plasma CML levels were associated with E/A ratio (r = 0.44, P = 0.04 and e' (r = 0.51, P = 0.02 and LMWF levels were associated with E/A ratio (r = 0.49, P = 0.02. Moreover, the mitral E/A ratio remained correlated with plasma LMWF levels in all patients (P = 0.04 and the

  10. Increased Receptor for Advanced Glycation End Product Expression in the Human Alcoholic Prefrontal Cortex is Linked to Adolescent Drinking

    Science.gov (United States)

    Vetreno, Ryan P.; Qin, Liya; Crews, Fulton T.

    2013-01-01

    Adolescence is characterized behaviorally by increased impulsivity and risk-taking that declines in parallel with maturation of the prefrontal cortex and executive function. In the brain, the receptor for advanced glycation end products (RAGE) is critically involved in neurodevelopment and neuropathology. In humans, the risk of alcoholism is greatly increased in those who begin drinking between 13 and 15 years of age, and adolescents binge drink more than any other age group. We have previously found that alcoholism is associated with increased expression of neuroimmune genes. This manuscript tested the hypothesis that adolescent binge drinking upregulates RAGE and Toll-like receptor (TLR) 4 as well as their endogenous agonist, high-mobility group box 1 (HMGB1). Immunohistochemistry, Western blot, and mRNA analyses found that RAGE expression was increased in the human post-mortem alcoholic orbitofrontal cortex (OFC). Further, an earlier age of drinking onset correlated with increased expression of RAGE, TLR4, and HMGB1. To determine if alcohol contributed to these changes, we used an adolescent binge ethanol model in rats (5.0 g/kg, i.g., 2-day on/2-day off from postnatal day [P] 25 to P55) and assessed neuroimmune gene expression. We found an age-associated decline of RAGE expression from late adolescence (P56) to young adulthood (P80). Adolescent intermittent ethanol exposure did not alter RAGE expression at P56, but increased RAGE in the young adult PFC (P80). Adolescent intermittent ethanol exposure also increased TLR4 and HMGB1 expression at P56 that persisted into young adulthood (P80). Assessment of young adult frontal cortex mRNA (RT-PCR) found increased expression of proinflammatory cytokines, oxidases, and neuroimmune agonists at P80, 25 days after ethanol treatment. Together, these human and animal data support the hypothesis that an early age of drinking onset upregulates RAGE/TLR4-HMGB1 and other neuroimmune genes that persist into young adulthood and

  11. Peri-implant conditions and levels of advanced glycation end products among patients with different glycemic control.

    Science.gov (United States)

    Al-Sowygh, Zeyad H; Ghani, Siti Mariam Ab; Sergis, Konstantinos; Vohra, Fahim; Akram, Zohaib

    2018-01-19

    A close relationship between poor glycemic control and peri-implant break down has been demonstrated. It is hypothesized that levels of advanced glycation end products (AGEs) in peri-implant sulcular fluid (PISF) are higher with increased glycemic levels in type 2 diabetes mellitus patients. In the present study, we examined the clinical and radiographic peri-implant parameters and levels of AGEs among different glycemic levels in diabetic patients and assessed whether the levels of AGEs correlate with clinical peri-implant parameters. Ninety-three patients who participated in this study were divided into four groups; Group-1: HbA1c 6.1%-8%; Group-2: HbA1c 8.1%-10%; Group-3: HbA1c > 10%; Group-4: non-diabetic individuals with HbA1c implant plaque index (PI), bleeding on probing (BOP), probing depth (PD) and crestal bone loss (CBL) were recorded. Levels of AGEs in PISF were quantified using enzyme-linked immunosorbent assay. Between-group comparison of means was verified with Kruskal-Wallis test and Pearson correlation coefficient for correlations of AGE levels with peri-implant parameters. Peri-implant PI, BOP, PD, and CBL were significantly higher in group-1, -2, and -3 as compared to non-diabetic patients (P  .05). Mean levels of AGEs in PISF were significantly higher in relation to higher levels of HbA1c levels. Significant positive correlations were found between AGEs and PD (P = .0221) and CBL (P = .0425); and significant negative correlation was found for PI (P = .0376) in patients with HbA1c levels >10%, respectively. Clinical and radiographic peri-implant parameters were poor and levels of AGEs were significantly high in patients with high glycemic levels. These findings suggest that AGEs may be considered as potential marker of inflammation in diabetic individuals with peri-implantitis. © 2018 Wiley Periodicals, Inc.

  12. Dietary consumption of advanced glycation end products and pancreatic cancer in the prospective NIH-AARP Diet and Health Study.

    Science.gov (United States)

    Jiao, Li; Stolzenberg-Solomon, Rachael; Zimmerman, Thea Palmer; Duan, Zhigang; Chen, Liang; Kahle, Lisa; Risch, Adam; Subar, Amy F; Cross, Amanda J; Hollenbeck, Albert; Vlassara, Helen; Striker, Gary; Sinha, Rashmi

    2015-01-01

    Advanced glycation end products (AGEs) are a heterogeneous group of compounds present in uncooked foods as well as in foods cooked at high temperatures. AGEs have been associated with insulin resistance, oxidative stress, and chronic inflammation in patients with diabetes. Dietary AGEs are an important contributor to the AGE pool in the body. N(ϵ)-(carboxymethyl)lysine (CML) AGE is one of the major biologically and chemically well-characterized AGE markers. The consumption of red meat, which is CML-AGE rich, has been positively associated with pancreatic cancer in men. With the use of a published food CML-AGE database, we estimated the consumption of CML AGE in the prospective NIH-AARP Diet and Health Study and evaluated the association between CML-AGE consumption and pancreatic cancer and the mediating effect of CML AGE on the association between red meat consumption and pancreatic cancer. Multivariate Cox proportional hazard regression models were used to estimate HRs and 95% CIs for pancreatic cancer. During an average of 10.5 y of follow-up, we identified 2193 pancreatic cancer cases (1407 men and 786 women) from 528,251 subjects. With the comparison of subjects in the fifth and the first quintiles of CML-AGE consumption, we observed increased pancreatic cancer risk in men (HR: 1.43; 95% CI: 1.06, 1.93, P-trend = 0.003) but not women (HR: 1.14; 95% CI: 0.76, 1.72, P-trend = 0.42). Men in the highest quintile of red meat consumption had higher risk of pancreatic cancer (HR: 1.35; 95% CI: 1.07, 1.70), which attenuated after adjustment for CML-AGE consumption (HR: 1.20; 95% CI: 0.95, 1.53). Dietary CML-AGE consumption was associated with modestly increased risk of pancreatic cancer in men and may partially explain the positive association between red meat and pancreatic cancer. © 2015 American Society for Nutrition.

  13. HMGB1/Advanced Glycation End Products (RAGE) does not aggravate inflammation but promote endogenous neural stem cells differentiation in spinal cord injury.

    Science.gov (United States)

    Wang, Hongyu; Mei, Xifan; Cao, Yang; Liu, Chang; Zhao, Ziming; Guo, Zhanpeng; Bi, Yunlong; Shen, Zhaoliang; Yuan, Yajiang; Guo, Yue; Song, Cangwei; Bai, Liangjie; Wang, Yansong; Yu, Deshui

    2017-09-04

    Receptor for advanced glycation end products (RAGE) signaling is involved in a series of cell functions after spinal cord injury (SCI). Our study aimed to elucidate the effects of RAGE signaling on the neuronal recovery after SCI. In vivo, rats were subjected to SCI with or without anti-RAGE antibodies micro-injected into the lesion epicenter. We detected Nestin/RAGE, SOX-2/RAGE and Nestin/MAP-2 after SCI by Western blot or immunofluorescence (IF). We found that neural stem cells (NSCs) co-expressed with RAGE were significantly activated after SCI, while stem cell markers Nestin and SOX-2 were reduced by RAGE blockade. We found that RAGE inhibition reduced nestin-positive NSCs expressing MAP-2, a mature neuron marker. RAGE blockade does not improve neurobehavior Basso, Beattie and Bresnahan (BBB) scores; however, it damaged survival of ventral neurons via Nissl staining. Through in vitro study, we found that recombinant HMGB1 administration does not lead to increased cytokines of TNF-α and IL-1β, while anti-RAGE treatment reduced cytokines of TNF-α and IL-1β induced by LPS via ELISA. Meanwhile, HMGB1 increased MAP-2 expression, which was blocked after anti-RAGE treatment. Hence, HMGB1/RAGE does not exacerbate neuronal inflammation but plays a role in promoting NSCs differentiating into mature neurons in the pathological process of SCI.

  14. Long-term administration of advanced glycation end-product stimulates the activation of NLRP3 inflammasome and sparking the development of renal injury.

    Science.gov (United States)

    Yeh, Wan-Ju; Yang, Hsin-Yi; Pai, Man-Hui; Wu, Chi-Hao; Chen, Jiun-Rong

    2017-01-01

    The accumulation of advanced glycation end-products (AGEs) and the enhanced interaction of AGE with their cellular receptor (RAGE) have been implicated in the progression of chronic kidney disease. The purpose of this study was to examine whether the AGE/RAGE-induced nephrotoxic effects are associated with inflammasome activation and endothelial dysfunction. Chronic renal injury was examined in BALB/c mice by the long-term administration of carbonyl-AGE for 16 weeks. Endothelial dysfunction was detected by measuring the number of circulating endothelial progenitor cells (EPCs) and the levels of nitric oxide synthase (eNOS) and nitric oxide (NO) in kidneys. Results showed that administration of methylglyoxal-bovine serum albumin (MG-BSA) AGE accelerated renal MG, carboxyethyl lysine, carboxymethyl lysine and malondialdehyde formation and, in parallel, the levels of serum creatinine and blood urea nitrogen (BUN) were significantly increased. Expression of RAGE and NLRP3 inflammasome-related proteins (TXNIP, NLRP3, procaspase-1 and caspase-1) and IL (interleukin)-1β secretion were upregulated, whereas the levels of EPCs, eNOS and NO were lower in MG-BSA-treated mice. This induction by MG-BSA was significantly inhibited by RAGE antagonist. Our results firstly reveal a possible mechanism of AGE-mediated renal dysfunction upon NLRP3 inflammasome activation. Therapeutic blockade of RAGE may ameliorate renal and endothelial functions in subjects under high AGE burden. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Lower concentrations of receptor for advanced glycation end products and epiregulin in amniotic fluid correlate to chemically induced cleft palate in mice.

    Science.gov (United States)

    Wang, Xinhuan; Zhu, Jingjing; Fang, Yanjun; Bian, Zhuan; Meng, Liuyan

    2017-04-01

    This study investigated the correlation between differentially expressed proteins in amniotic fluid (AF) and cleft palate induced by all-trans retinoic acid (atRA), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. Seven proteins were differentially expressed at embryonic day (E) 16.5 in atRA and control groups as revealed by label-based mouse antibody array. Enzyme-linked immunosorbent assay was further used to detect the expression levels of these proteins in AF from E13.5 to E16.5 in atRA, TCDD, and control groups. The cleft palate groups showed lower concentrations of receptor for advanced glycation end products (RAGE) and epiregulin at E16.5. RAGE immunostaining obviously decreased in palatal tissue sections obtained from E14.5 to E16.5 in the cleft palate groups as revealed by immunohistochemistry. These findings indicate that reduced levels of RAGE and epiregulin in AF are correlated to chemically induced cleft palate in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. The Receptor for Advanced Glycation End Products (Rage) and Its Ligands in Plasma and Infrainguinal Bypass Vein.

    Science.gov (United States)

    Malmstedt, J; Frebelius, S; Lengquist, M; Jörneskog, G; Wang, J; Swedenborg, J

    2016-04-01

    The aim was to investigate whether RAGE and its ligands are associated with infrainguinal bypass outcome in patients with and without diabetes. This was a prospective observational cohort. Patients (n = 68) with (n = 38) and without (n = 30) diabetes undergoing infrainguinal vein bypass for peripheral arterial disease were followed for 3 years. Endosecretory RAGE (esRAGE), S100A12, advanced glycation end products, and carboxymethyl-lysine (CML) were determined in plasma using ELISA. The influence of plasma levels on the main outcome (amputation free survival) was evaluated using Cox proportional hazard analysis. Plasma esRAGE, CML, and S100A12 in healthy controls (n = 30) without cardiovascular disease matched for sex and age were compared with patients, using the Mann-Whitney U test. Veins from bypass surgery procedures were stained and S100A12, RAGE, AGE, and CML were determined using immunohistochemistry. Forty-six patients survived with an intact leg during follow up. Seventeen died (median survival time 702 days, IQR 188-899 day), and six had amputations. High plasma S100A12 was associated with reduced amputation free survival (hazard ratio [HR] 2.99; 95% CI 1.24-7.24) when comparing levels above the 75th percentile with levels below. The increased risk was unchanged adjusting for age, sex, and diabetes. Diabetic patients had higher plasma S100A12 (11.75 ng/mL; 95% CI 8.12-15.38 ng/mL) than non-diabetic patients (5.0141 ng/mL; 95% CI 3.62-6.41 ng/mL), whereas plasma CML, esRAGE, and AGE were similar. Plasma CML and S100A12 were higher in patients than in controls (1.25 μg/mL, 95% CI 1.18-1.32 μg/mL vs. 0.8925 μg/mL, 95% CI 0.82-0.96 μg/mL; and 8.7 μg/mL, 95% CI 6.52-10.95 μg/mL vs. 3.47 μg/mL, 95% CI 2.95-3.99 μg/mL, respectively). The proportion of vein tissue stained for AGE (21%), RAGE (5%), CML (9%) and S100A12 (3%), were similar in patients with and without diabetes. Plasma S100A12 and CML are elevated in peripheral arterial disease and markers of

  17. Association of the receptor for advanced glycation end-products (RAGE) gene polymorphisms in Malaysian patients with chronic kidney disease.

    Science.gov (United States)

    Wong, Foo Nian; Chua, Kek Heng; Kuppusamy, Umah Rani; Wong, Chew Ming; Lim, Soo Kun; Tan, Jin Ai Mary Anne

    2016-01-01

    Chronic kidney disease (CKD) is a condition associated with progressive loss of kidney function and kidney damage. The two common causes of CKD are diabetes mellitus and hypertension. Other causes of CKD also include polycystic kidney disease, obstructive uropathy and primary glomerulonephritis. The receptor for advanced glycation end-products (RAGE) is a multi-ligand cell surface receptor of the immunoglobulin superfamily and it has been associated with kidney disease in both non-diabetic and diabetic patients. Presently, data on the association between RAGE polymorphisms and CKD in the Malaysian population is limited, while numerous studies have reported associations of RAGE polymorphisms with diabetic complications in other populations. The present study aims to explore the possibility of using RAGE polymorphisms as candidate markers of CKD in Malaysian population by using association analysis. A total of 102 non-diabetic CKD patients, 204 diabetic CKD patients and 345 healthy controls were enrolled in the study. DNA isolated from blood samples were subjected to genotyping of RAGE G82S, -374T/A, -429T/C, 1704G/T and 2184A/G polymorphisms using real-time polymerase chain reaction (PCR). The 63-bp deletion, a polymorphism in the RAGE gene promoter, was genotyped using conventional PCR method and visualized using agarose gel electrophoresis. The collective frequencies of genotypes with at least one copy of the minor alleles of the four polymorphisms were compared between the non-diabetic CKD patients, diabetic CKD patients and healthy controls. After adjustment of age, gender and ethnic groups in binary logistic regression analysis, the G82S CT + TT genotypes were associated with non-diabetic CKD patients when compared with diabetic CKD patients (p = 0.015, OR = 1.896, 95% CI = 1.132-3.176). After further adjustment of CKD comorbidities, the G82S CT + TT genotypes were still associated with non-diabetic CKD patients when compared with diabetic CKD patients (p = 0

  18. Obesity associated advanced glycation end products within the human uterine cavity adversely impact endometrial function and embryo implantation competence.

    Science.gov (United States)

    Antoniotti, Gabriella S; Coughlan, Melinda; Salamonsen, Lois A; Evans, Jemma

    2018-04-01

    Do obese levels of advanced glycation end products (AGEs) within the uterine cavity detrimentally alter tissue function in embryo implantation and placental development? Obese levels of AGEs activate inflammatory signaling (p65 NFκB) within endometrial epithelial cells and alter their function, cause endoplasmic reticulum (ER) stress in endometrial stromal cells and impair decidualization, compromise implantation of blastocyst mimics and inhibit trophoblast invasion. Obese women experience a higher incidence of infertility, recurrent miscarriage and pregnancy complications compared with lean women. Oocyte donation cycles suggest a detrimental uterine environment plays a role in these outcomes. Uterine lavage and tissues from lean (BMI 19.5-24.9, n = 17) and obese (BMI > 30, n = 16) women examined. Cell culture experiments utilizing human endometrial epithelial, trophectoderm and trophoblast cell lines and primary human stromal cells used to examine the functional impact of obese levels of AGEs. Levels of AGEs examined within uterine lavage assessed by ELISA to determine differences between lean and obese women. Expression and localization of AGEs, receptor for AGEs (RAGE) and NFκB within endometrial tissues obtained from lean and obese women determined by immunohistochemistry. Endometrial epithelial cells (ECC-1), primary human stromal cells and trophoblast cells (HTR8-SVneo) treated with lean (2000 nmol/mol lysine) or obese (8000 nmol/mol lysine) uterine levels of AGEs and p65 NFκB (western immunoblot), real-time adhesion, proliferation migration and invasion (xCelligence real-time cell function analysis), decidualization (cell morphology and prolactin release), ER stress (western immunoblot for p-PERK) determined. Co-cultures of endometrial epithelial cells and blastocyst mimics (trophectoderm spheroids) similarly treated with lean or obese uterine levels of AGEs to determine their impact on embryo implantation. AGEs were significantly elevated (P = 0

  19. Association of the receptor for advanced glycation end-products (RAGE gene polymorphisms in Malaysian patients with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Foo Nian Wong

    2016-04-01

    Full Text Available Background: Chronic kidney disease (CKD is a condition associated with progressive loss of kidney function and kidney damage. The two common causes of CKD are diabetes mellitus and hypertension. Other causes of CKD also include polycystic kidney disease, obstructive uropathy and primary glomerulonephritis. The receptor for advanced glycation end-products (RAGE is a multi-ligand cell surface receptor of the immunoglobulin superfamily and it has been associated with kidney disease in both non-diabetic and diabetic patients. Presently, data on the association between RAGE polymorphisms and CKD in the Malaysian population is limited, while numerous studies have reported associations of RAGE polymorphisms with diabetic complications in other populations. The present study aims to explore the possibility of using RAGE polymorphisms as candidate markers of CKD in Malaysian population by using association analysis. Methods: A total of 102 non-diabetic CKD patients, 204 diabetic CKD patients and 345 healthy controls were enrolled in the study. DNA isolated from blood samples were subjected to genotyping of RAGE G82S, −374T/A, −429T/C, 1704G/T and 2184A/G polymorphisms using real-time polymerase chain reaction (PCR. The 63-bp deletion, a polymorphism in the RAGE gene promoter, was genotyped using conventional PCR method and visualized using agarose gel electrophoresis. The collective frequencies of genotypes with at least one copy of the minor alleles of the four polymorphisms were compared between the non-diabetic CKD patients, diabetic CKD patients and healthy controls. Results: After adjustment of age, gender and ethnic groups in binary logistic regression analysis, the G82S CT + TT genotypes were associated with non-diabetic CKD patients when compared with diabetic CKD patients (p = 0.015, OR = 1.896, 95% CI = 1.132–3.176. After further adjustment of CKD comorbidities, the G82S CT + TT genotypes were still associated with non-diabetic CKD

  20. Crosslinking by advanced glycation end products increases the stiffness of the collagen network in human articular cartilage: A possible mechanism through which age is a risk factor for osteoarthritis

    NARCIS (Netherlands)

    Verzijl, N.; Groot, J. de; Zaken, C.B.; Braun-Benjamin, O.; Maroudas, A.; Bank, R.A.; Mizrahi, J.; Schalkwijk, C.G.; Thorpe, S.R.; Baynes, J.W.; Bijlsma, J.W.J.; Lafeber, F.P.J.G.; TeKoppele, J.M.

    2002-01-01

    Objective. Age is an important risk factor for osteoarthritis (OA). During aging, nonenzymatic glycation results in the accumulation of advanced glycation end products (AGEs) in cartilage collagen. We studied the effect of AGE crosslinking on the stiffness of the collagen network in human articular

  1. 糖基化终末产物及其受体在糖尿病大鼠胃组织中的分布 (Distribution of advanced glycation end products and their receptor in the stomach of diabetic rats)

    DEFF Research Database (Denmark)

    Tian, Jia Xing; Zhao, Jingbo; Li, Min

    2015-01-01

    AIM: To observe the distribution of advanced glycation end products (AGEs) and their receptor (RAGE) in the stomach of diabetic rats. METHODS: Diabetes mellitus (DM) and control (CON) rats were reared for eight weeks. Fasting plasma glucose (FPG), glycated serum protein (GSP) and gastric layer...

  2. Age dependent accumulation patterns of advanced glycation end product receptor (RAGE) ligands and binding intensities between RAGE and its ligands differ in the liver, kidney, and skeletal muscle.

    Science.gov (United States)

    Son, Myeongjoo; Chung, Wook-Jin; Oh, Seyeon; Ahn, Hyosang; Choi, Chang Hu; Hong, Suntaek; Park, Kook Yang; Son, Kuk Hui; Byun, Kyunghee

    2017-01-01

    Much evidence indicates receptor for advanced glycation end products (RAGE) related inflammation play essential roles during aging. However, the majority of studies have focused on advanced glycation end products (AGEs) and not on other RAGE ligands. In the present study, the authors evaluated whether the accumulation of RAGE ligands and binding intensities between RAGE and its ligands differ in kidney, liver, and skeletal muscle during aging. In C57BL/6 N mice aged 12 weeks, 12 months, and 22 months, ligands accumulation, binding intensities between RAGE and its ligands, activated macrophage infiltration, M1/M2 macrophage expression, glyoxalase-1expression, and signal pathways related to inflammation were evaluated. The RAGE ligands age-associated accumulation patterns were found to be organ dependent. Binding intensities between RAGE and its ligands in kidney and liver increased with age, but those in skeletal muscle were unchanged. Infiltration of activated macrophages in kidney and liver increased with age, but infiltration in the skeletal muscle was unchanged. M1 expression increased and M2 and glyoxalase-1 expression decreased with age in kidney and liver, but their expressions in skeletal muscle were not changed. These findings indicate patterns of RAGE ligands accumulation, RAGE/ligands binding intensities, or inflammation markers changes during aging are organs dependent.

  3. Receptor for advanced glycation end-products promotes premature senescence of proximal tubular epithelial cells via activation of endoplasmic reticulum stress-dependent p21 signaling.

    Science.gov (United States)

    Liu, Jun; Huang, Kun; Cai, Guang-Yan; Chen, Xiang-Mei; Yang, Ju-Rong; Lin, Li-Rong; Yang, Jie; Huo, Ben-Gang; Zhan, Jun; He, Ya-Ni

    2014-01-01

    Premature senescence is a key process in the progression of diabetic nephropathy (DN). In our study, we hypothesized that receptors for advanced glycation end-products (RAGE) mediate endoplasmic reticulum (ER) stress to induce premature senescence via p21 signaling activation in diabetic nephropathy. Here, we demonstrated that elevated expression of RAGE, ER stress marker glucose-regulated protein 78 (GRP78), and cell-cycle regulator p21 was all positively correlated with enhanced senescence-associated-β-galactosidase (SA-β-gal) activity in DN patients. In addition, the fraction of SA-β-gal or cells in the G0G1 phase were enhanced in cultured mouse proximal tubular epithelial cells (PTECs) and the expression of RAGE, GRP78 and p21 was up-regulated by advanced glycation end-products (AGEs) in a dose- and time-dependent manner. Interestingly, ER stress inducers or RAGE overexpression mimicked AGEs induced-premature senescence, and this was significantly suppressed by p21 gene silencing. However, RAGE blocking successfully attenuated AGEs-induced ER stress and p21 expression, as well as premature senescence. Moreover, ER stress inducers directly caused p21 activation, premature senescence, and also enhanced RAGE expression by positive feedback. These observations suggest that RAGE promotes premature senescence of PTECs by activation of ER stress-dependent p21 signaling. © 2013.

  4. Advanced glycation end products induce human corneal epithelial cells apoptosis through generation of reactive oxygen species and activation of JNK and p38 MAPK pathways.

    Directory of Open Access Journals (Sweden)

    Long Shi

    Full Text Available Advanced Glycation End Products (AGEs has been implicated in the progression of diabetic keratopathy. However, details regarding their function are not well understood. In the present study, we investigated the effects of intracellular reactive oxygen species (ROS and JNK, p38 MAPK on AGE-modified bovine serum albumin (BSA induced Human telomerase-immortalized corneal epithelial cells (HUCLs apoptosis. We found that AGE-BSA induced HUCLs apoptosis and increased Bax protein expression, decreased Bcl-2 protein expression. AGE-BSA also induced the expression of receptor for advanced glycation end product (RAGE. AGE-BSA-RAGE interaction induced intracellular ROS generation through activated NADPH oxidase and increased the phosphorylation of p47phox. AGE-BSA induced HUCLs apoptosis was inhibited by pretreatment with NADPH oxidase inhibitors, ROS quencher N-acetylcysteine (NAC or neutralizing anti-RAGE antibodies. We also found that AGE-BSA induced JNK and p38 MAPK phosphorylation. JNK and p38 MAPK inhibitor effectively blocked AGE-BSA-induced HUCLs apoptosis. In addition, NAC completely blocked phosphorylation of JNK and p38 MAPK induced by AGE-BSA. Our results indicate that AGE-BSA induced HUCLs apoptosis through generation of intracellular ROS and activation of JNK and p38 MAPK pathways.

  5. Higher plasma levels of advanced glycation end products are associated with incident cardiovascular disease and all-cause mortality in type 1 diabetes

    DEFF Research Database (Denmark)

    Nin, Johanna W; Jorsal, Anders; Ferreira, Isabel

    2011-01-01

    OBJECTIVE: To investigate the associations of plasma levels of advanced glycation end products (AGEs) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunction, low-gr......-related pathophysiological mechanisms. Thus, AGEs may explain, in part, the increased cardiovascular disease and mortality attributable to type 1 diabetes and constitute a specific target for treatment in these patients.......OBJECTIVE: To investigate the associations of plasma levels of advanced glycation end products (AGEs) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunction, low......-grade inflammation, and arterial stiffness. RESEARCH DESIGN AND METHODS: We prospectively followed 169 individuals with diabetic nephropathy and 170 individuals with persistent normoalbuminuria who were free of CVD at study entry and in whom levels of N(ε)-(carboxymethyl)lysine, N...

  6. Receptor of advanced glycation end products (RAGE) positively regulates CD36 expression and reactive oxygen species production in human monocytes in diabetes.

    Science.gov (United States)

    Xanthis, A; Hatzitolios, A; Fidani, S; Befani, C; Giannakoulas, G; Koliakos, G

    Advanced glycation end products (AGEs) engagement of a monocyte surface receptor (RAGE) induces atherosclerosis. AGEs also act as CD36 ligands. We studied reactive oxygen species (ROS) and CD36 expression after siRNA inhibition of RAGE expression in human monocytes. We isolated monocytes from: a) 10 type 2 diabetics, and b) 5 age- and sex-matched healthy individuals. CD36 expression and ROS production were evaluated before and after RAGE knockdown. After incubation of monocytes with AGE + bovine serum albumin (BSA), CD36 expression and intracellular ROS increased significantly in all groups. In RAGE-knockdown monocytes, AGE-induced CD36 expression and ROS generation were also significantly inhibited. Blocking RAGE expression using siRNA in human monocytes led to a significant inhibition of CD36 expression and ROS production, suggesting a positive interaction between RAGE, CD36 expression and ROS generation in monocytes.

  7. Metformin Inhibits Advanced Glycation End Products-Induced Inflammatory Response in Murine Macrophages Partly through AMPK Activation and RAGE/NFκB Pathway Suppression

    Directory of Open Access Journals (Sweden)

    Zhong’e Zhou

    2016-01-01

    Full Text Available Advanced glycation end products (AGEs are major inflammatory mediators in diabetes, affecting atherosclerosis progression via macrophages. Metformin slows diabetic atherosclerosis progression through mechanisms that remain to be fully elucidated. The present study of murine bone marrow derived macrophages showed that (1 AGEs enhanced proinflammatory cytokines (interleukin-1β (IL-1β, IL-6, and tumor necrosis factor-α (TNF-α mRNA expression, RAGE expression, and NFκB activation; (2 metformin pretreatment inhibited AGEs effects and AGEs-induced cluster designation 86 (CD86 (M1 marker expression, while promoting CD206 (M2 marker surface expression and anti-inflammatory cytokine (IL-10 mRNA expression; and (3 the AMPK inhibitor, Compound C, attenuated metformin effects. In conclusion, metformin inhibits AGEs-induced inflammatory response in murine macrophages partly through AMPK activation and RAGE/NFκB pathway suppression.

  8. Assessment of the concentrations of various advanced glycation end-products in beverages and foods that are commonly consumed in Japan.

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    Masayoshi Takeuchi

    Full Text Available Dietary consumption has recently been identified as a major environmental source of pro-inflammatory advanced glycation end-products (AGEs in humans. It is disputed whether dietary AGEs represent a risk to human health. Nε-(carboxymethyllysine (CML, a representative AGE compound found in food, has been suggested to make a significant contribution to circulating CML levels. However, recent studies have found that the dietary intake of AGEs is not associated with plasma CML concentrations. We have shown that the serum levels of glyceraldehyde-derived AGEs (Glycer-AGEs, but not hemoglobin A1c, glucose-derived AGEs (Glu-AGEs, or CML, could be used as biomarkers for predicting the progression of atherosclerosis and future cardiovascular events. We also detected the production/accumulation of Glycer-AGEs in normal rats administered Glu-AGE-rich beverages. Therefore, we assessed the concentrations of various AGEs in a total of 1,650 beverages and foods that are commonly consumed in Japan. The concentrations of four kinds of AGEs (Glu-AGEs, fructose-derived AGEs (Fru-AGEs, CML, and Glycer-AGEs were measured with competitive enzyme-linked immunosorbent assays involving immunoaffinity-purified specific antibodies. The results of the latter assays indicated that Glu-AGEs and Fru-AGEs (especially Glu-AGEs, but not CML or Glycer-AGEs, are present at appreciable levels in beverages and foods that are commonly consumed by Japanese. Glu-AGEs, Fru-AGEs, CML, and Glycer-AGEs exhibited concentrations of ≥85%, 2-12%, <3%, and trace amounts in the examined beverages and ≥82%, 5-15%, <3%, and trace amounts in the tested foods, respectively. The results of the present study indicate that some lactic acid bacteria beverages, carbonated drinks, sugar-sweetened fruit drinks, sports drinks, mixed fruit juices, confectionery (snacks, dried fruits, cakes, cereals, and prepared foods contain markedly higher Glu-AGE levels than other classes of beverages and foods. We

  9. Soluble Forms and Ligands of the Receptor for Advanced Glycation End-Products in Patients with Acute Respiratory Distress Syndrome: An Observational Prospective Study.

    Directory of Open Access Journals (Sweden)

    Matthieu Jabaudon

    Full Text Available The main soluble form of the receptor for advanced glycation end-products (sRAGE is elevated during acute respiratory distress syndrome (ARDS. However other RAGE isoforms and multiple ligands have been poorly reported in the clinical setting, and their respective contribution to RAGE activation during ARDS remains unclear. Our goal was therefore to describe main RAGE isoforms and ligands levels during ARDS.30 ARDS patients and 30 mechanically ventilated controls were prospectively included in this monocenter observational study. Arterial, superior vena cava and alveolar fluid levels of sRAGE, endogenous-secretory RAGE (esRAGE, high mobility group box-1 protein (HMGB1, S100A12 and advanced glycation end-products (AGEs were measured in duplicate ELISA on day 0, day 3 and day 6. In patients with ARDS, baseline lung morphology was assessed with computed tomography.ARDS patients had higher arterial, central venous and alveolar levels of sRAGE, HMGB1 and S100A12, but lower levels of esRAGE and AGEs, than controls. Baseline arterial sRAGE, HMGB1 and S100A12 were correlated with nonfocal ARDS (AUC 0.79, 0.65 and 0.63, respectively. Baseline arterial sRAGE, esRAGE, S100A12 and AGEs were associated with severity as assessed by PaO2/FiO2.This is the first kinetics study of levels of RAGE main isoforms and ligands during ARDS. Elevated sRAGE, HMGB1 and S100A12, with decreased esRAGE and AGEs, were found to distinguish patients with ARDS from those without. Our findings should prompt future studies aimed at elucidating RAGE/HMGB1/S100A12 axis involvement in ARDS.clinicaltrials.gov Identifier: NCT01270295.

  10. Effect of PKC-β Signaling Pathway on Expression of MCP-1 and VCAM-1 in Different Cell Models in Response to Advanced Glycation End Products (AGEs

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    Lisienny C. T. Rempel

    2015-05-01

    Full Text Available Advanced glycation end products (AGEs are compounds classified as uremic toxins in patients with chronic kidney disease that have several pro-inflammatory effects and are implicated in the development of cardiovascular diseases. To explore the mechanisms of AGEs–endothelium interactions through the receptor for AGEs (RAGE in the PKC-β pathway, we evaluated the production of MCP-1 and VCAM-1 in human endothelial cells (HUVECs, monocytes, and a coculture of both. AGEs were prepared by albumin glycation and characterized by absorbance and electrophoresis. The effect of AGEs on cell viability was assessed with an MTT assay. The cells were also treated with AGEs with and without a PKC-β inhibitor. MCP-1 and VCAM-1 in the cell supernatants were estimated by ELISA, and RAGE was evaluated by immunocytochemistry. AGEs exposure did not affect cell viability, but AGEs induced RAGE, MCP-1, and VCAM-1 expression in HUVECs. When HUVECs or monocytes were incubated with AGEs and a PKC-β inhibitor, MCP-1 and VCAM-1 expression significantly decreased. However, in the coculture, exposure to AGEs and a PKC-β inhibitor produced no significant effect. This study demonstrates, in vitro, the regulatory mechanisms involved in MCP-1 production in three cellular models and VCAM-1 production in HUVECs, and thus mimics the endothelial dysfunction caused by AGEs in early atherosclerosis. Such mechanisms could serve as therapeutic targets to reduce the harmful effects of AGEs in patients with chronic kidney disease.

  11. Intra-molecular lysine-arginine derived advanced glycation end-product cross-linking in Type I collagen: A molecular dynamics simulation study.

    Science.gov (United States)

    Collier, Thomas A; Nash, Anthony; Birch, Helen L; de Leeuw, Nora H

    2016-11-01

    Covalently cross-linked advanced glycation end products (AGE) are among the major post-translational modifications to proteins as a result of non-enzymatic glycation. The formation of AGEs has been shown to have adverse effects on the properties of the collagenous tissue; they are even linked to a number of age related disorders. Little is known about the sites at which these AGEs form or why certain sites within the collagen are energetically more favourable than others. In this study we have used a proven fully atomistic molecular dynamics approach to identify six sites where the formation of the intra-molecular 3-deoxyglucosone-derived imidazolium cross-link (DOGDIC) is energetically favourable. We have also conducted a comparison of these positions with those of the more abundant glucosepane cross-link, to determine any site preference. We show that when we consider both lysine and arginine AGEs, they exhibit a prevalence to form within the gap region of the collagen fibril. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  12. N-Acetyl Cysteine Attenuated the Deleterious Effects of Advanced Glycation End-Products on the Kidney of Non-Diabetic Rats

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    Karina Thieme

    2016-11-01

    Full Text Available Aim: To assess the renal effects of chronic exposure to advanced glycation end-products (AGEs in the absence of diabetes and the potential impact of concomitant treatment with the antioxidant N-acetyl cysteine (NAC. Methods: Wistar rats received intraperitoneally 20 mg/kg/day of albumin modified (AlbAGE or not (AlbC by advanced glycation for 12 weeks and oral NAC (600mg/L; AlbAGE+NAC and AlbC+NAC, respectively. Biochemical, urinary and renal morphological analyses; carboxymethyl-lysine (CML, an AGE, CD68 (macrophage infiltration, and 4-hydroxynonenal (4-HNE, marker of oxidative stress immunostaining; intrarenal mRNA expression of genes belonging to pathways related to AGEs (Ager, Ddost, Nfkb1, renin-angiotensin system (Agt, Ren, Ace, fibrosis (Tgfb1, Col4a1, oxidative stress (Nox4, Txnip, and apoptosis (Bax, Bcl2; and reactive oxidative species (ROS content were performed. Results: AlbAGE significantly increased urine protein-to-creatinine ratio; glomerular area; renal CML content and macrophage infiltration; expression of Ager, Nfkb1, Agt, Ren, Tgfb1, Col4a1, Txnip, Bax/Bcl2 ratio; and 4-HNE and ROS contents. Some of these effects were attenuated by NAC concomitant treatment. Conclusion: Because AGEs are highly consumed in modern diets and implicated in the progression of different kidney diseases, NAC could be a therapeutic intervention to decrease renal damage, considering that long-term restriction of dietary AGEs is difficult to achieve in practice.

  13. Inhibition of Advanced Glycation End-Product Formation and Antioxidant Activity by Extracts and Polyphenols from Scutellaria alpina L. and S. altissima L.

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    Izabela Grzegorczyk-Karolak

    2016-06-01

    Full Text Available Methanolic extracts from the aerial parts and roots of two Scutellaria species, S. alpina and S. altissima, and five polyphenols from these plants demonstrated a significant ability to inhibit the formation of advanced glycation end-products (AGE in vitro. S. alpina, which is richer in polyphenolic compounds, had strong antiglycation properties. These extracts demonstrated also high activity in the FRAP (ferric-reducing antioxidant power, antiradical (DPPH and lipid peroxidation inhibition assays. Among the pure compounds, baicalin was the strongest glycation inhibitor (90.4% inhibition at 100 μg/mL, followed by luteolin (85.4%. Two other flavone glycosides had about half of this activity. Verbascoside was similar to the reference drug aminoguanidine (71.2% and 75.9%, respectively. The strong correlation observed between AGE inhibition and total flavonoid content indicated that flavonoids contribute significantly to antiglycation properties. A positive correlation was also observed between antiglycative and antioxidant activities. The studied skullcap species can be considered as a potential source of therapeutic agents for hyperglycemia-related disorders.

  14. Below the Radar: Advanced Glycation End Products that Detour “around the side”: Is HbA1c not an accurate enough predictor of long term progression and glycaemic control in diabetes?

    OpenAIRE

    Forbes, Josephine M; Soldatos, Georgia; Thomas, Merlin C.

    2005-01-01

    Advanced glycation is the irreversible attachment of reducing sugars onto the free amino groups of proteins. Its physiological roles are thought to include the identification of senescent proteins and hence there is a time dependent accumulation of advanced glycation end products (AGEs). AGE labelled proteins are catabolised by cells into low molecular weight peptides and amino acids and excreted primarily via the kidneys. This process appears to be tightly controlled by AGE clearance recepto...

  15. Statins decrease vascular epithelial growth factor expression via down-regulation of receptor for advanced glycation end-products.

    Science.gov (United States)

    Tsujinaka, Hiroki; Itaya-Hironaka, Asako; Yamauchi, Akiyo; Sakuramoto-Tsuchida, Sumiyo; Shobatake, Ryogo; Makino, Mai; Masuda, Naonori; Hirai, Hiromasa; Takasawa, Shin; Ogata, Nahoko

    2017-09-01

    Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, possess pleiotropic effects that have been extended to modulation of various cellular behaviors. This study aimed to examine whether statins modulate vascular endothelial growth factor A ( VEGF-A ) expression in human retinal pigment epithelium (RPE) cells. Human RPE cells (h1RPE7), damaged by hydroquinone (HQ) + advanced glycation endproducts (AGE) in an in vitro AMD model, were treated with atorvastatin or lovastatin for 24 h. The expression of VEGF-A and receptor for AGE ( RAGE ) was evaluated by real-time RT-PCR. VEGF-A secretion was measured by ELISA. To investigate the impact of RAGE on VEGF-A expression, small interfering RNA (siRNA) for RAGE ( siRAGE ) was introduced into h1RPE7 cells and VEGF-A expression was measured by real-time RT-PCR. Deletions of VEGF-A and RAGE promoters were performed and transcriptional activities were measured after the addition of statins to HQ + AGE-damaged RPE cells. The mRNA levels of VEGF-A and RAGE and the levels of VEGF-A in the culture medium were increased by HQ + AGE. Both atorvastatin and lovastatin attenuated HQ + AGE-induced VEGF-A and RAGE expression. These statins also decreased VEGF-A levels in the culture medium. RNA interference of RAGE attenuated the up-regulation of VEGF-A in the HQ + AGE treated cells. The deletion analysis demonstrated that these statins attenuated RAGE promoter activation in HQ + AGE-damaged RPE cells. Statins attenuated HQ + AGE-induced VEGF expression by decreasing RAGE expression. As VEGF is an important factor in developing wet AMD, statins could decrease the risk of wet-type AMD and be used as preventive medicines.

  16. Extracellular matrix is modulated in advanced glycation end products milieu via a RAGE receptor dependent pathway boosted by transforming growth factor-β1 RAGE.

    Science.gov (United States)

    Serban, Andreea Iren; Stanca, Loredana; Geicu, Ovidiu Ionut; Munteanu, Maria Cristina; Costache, Marieta; Dinischiotu, Anca

    2015-01-01

    Interstitial fibrosis is induced by imbalances in extracellular matrix homeostasis. Advanced glycation end products (AGEs) can bind and activate the receptor for AGEs (RAGE), which is involved in diabetic nephropathy. We set out to identify the role of AGEs in producing alterations leading to matrix hypertrophy and the pathway through which aminoguanidine, as well as anti-RAGE and anti-transforming growth factor (TGF)-β1 antibody treatments could prevent these modifications. Human embryonic kidney (HEK-293) cells were exposed to glycated bovine serum albumin (AGE-BSA) and co-treated with neutralizing antibodies or aminoguanidine. The effects on the transcriptional and translational levels of RAGE, TGF-β1 and collagen IV were evaluated, while metalloproteinase activity was assessed by gelatin zymography. AGE-BSA (200 μg/mL) upregulated RAGE's expression, while TGF-β1 synthesis and the formation of its bioactive form were increased in a dose-dependent manner by AGEs. AGE-BSA exposure increased both matrix metalloproteinase (MMP) activity and collagen IV synthesis, boosted by TGF-β1 upregulation. Aminoguanidine's effects revealed that small concentrations (10 μmol/L) enhance AGE-BSA effects, by increasing the expression of RAGE and TGF-β1, while higher concentrations (100 μmol/L) contribute to their downregulation. Although AGEs regulate RAGE and TGF-β1 by distinct pathways, RAGE activation leads to a further increase of TGF-β1 levels. MMP-2 activity seems to rely on TGF-β1, while MMP-9 was dependent on RAGE. These factors converge to control collagen IV turnover. Furthermore, although the antibody treatments might appear more efficient than AG in decreasing collagen IV levels, the cells compensate the RAGE and TGF-β1 blockade by increasing the mRNA expression of these proteins. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  17. Inhibition of Advanced Glycation End Products (AGEs Accumulation by Pyridoxamine Modulates Glomerular and Mesangial Cell Estrogen Receptor α Expression in Aged Female Mice.

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    Simone Pereira-Simon

    Full Text Available Age-related increases in oxidant stress (OS play a role in regulation of estrogen receptor (ER expression in the kidneys. In this study, we establish that in vivo 17β-estradiol (E2 replacement can no longer upregulate glomerular ER expression by 21 months of age in female mice (anestrous. We hypothesized that advanced glycation end product (AGE accumulation, an important source of oxidant stress, contributes to these glomerular ER expression alterations. We treated 19-month old ovariectomized female mice with pyridoxamine (Pyr, a potent AGE inhibitor, in the presence or absence of E2 replacement. Glomerular ERα mRNA expression was upregulated in mice treated with both Pyr and E2 replacement and TGFβ mRNA expression decreased compared to controls. Histological sections of kidneys demonstrated decreased type IV collagen deposition in mice receiving Pyr and E2 compared to placebo control mice. In addition, anti-AGE defenses Sirtuin1 (SIRT1 and advanced glycation receptor 1 (AGER1 were also upregulated in glomeruli following treatment with Pyr and E2. Mesangial cells isolated from all groups of mice demonstrated similar ERα, SIRT1, and AGER1 expression changes to those of whole glomeruli. To demonstrate that AGE accumulation contributes to the observed age-related changes in the glomeruli of aged female mice, we treated mesangial cells from young female mice with AGE-BSA and found similar downregulation of ERα, SIRT1, and AGER1 expression. These results suggest that inhibition of intracellular AGE accumulation with pyridoxamine may protect glomeruli against age-related oxidant stress by preventing an increase of TGFβ production and by regulation of the estrogen receptor.

  18. A capture method based on the VC1 domain reveals new binding properties of the human receptor for advanced glycation end products (RAGE

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    Genny Degani

    2017-04-01

    Full Text Available The Advanced Glycation and Lipoxidation End products (AGEs and ALEs are a heterogeneous class of compounds derived from the non-enzymatic glycation or protein adduction by lipoxidation break-down products. The receptor for AGEs (RAGE is involved in the progression of chronic diseases based on persistent inflammatory state and oxidative stress. RAGE is a pattern recognition receptor (PRR and the inhibition of the interaction with its ligands or of the ligand accumulation have a potential therapeutic effect. The N-terminal domain of RAGE, the V domain, is the major site of AGEs binding and is stabilized by the adjacent C1 domain. In this study, we set up an affinity assay relying on the extremely specific biological interaction AGEs ligands have for the VC1 domain. A glycosylated form of VC1, produced in the yeast Pichia pastoris, was attached to magnetic beads and used as insoluble affinity matrix (VC1-resin. The VC1 interaction assay was employed to isolate specific VC1 binding partners from in vitro generated AGE-albumins and modifications were identified/localized by mass spectrometry analysis. Interestingly, this method also led to the isolation of ALEs produced by malondialdehyde treatment of albumins. Computational studies provided a rational-based interpretation of the contacts established by specific modified residues and amino acids of the V domain. The validation of VC1-resin in capturing AGE-albumins from complex biological mixtures such as plasma and milk, may lead to the identification of new RAGE ligands potentially involved in pro-inflammatory and pro-fibrotic responses, independently of their structures or physical properties, and without the use of any covalent derivatization process. In addition, the method can be applied to the identification of antagonists of RAGE-ligand interaction.

  19. Intrauterine hyperglycemia-induced inflammatory signalling via the receptor for advanced glycation end products in the cardiac muscle of the infants of diabetic mother rats.

    Science.gov (United States)

    Kawaharada, Ritsuko; Masuda, Haruna; Chen, Zhenyi; Blough, Eric; Kohama, Tomoko; Nakamura, Akio

    2017-09-23

    Gestational diabetes is associated with increased risk to the health of the mother and her offspring. In particular, the infants of diabetic mothers (IDMs) exhibit elevated levels of preterm birth, macrosomia, hypoglycemia, hypocalcemia, and cardiomyopathy. We have previously reported that IDMs showed abnormalities in cardiac Akt-related insulin signalling, and that these deficiencies in Akt-related signalling were attenuated by supplementing the maternal diet with fish-oil. Herein, we investigated whether the eicosapentaenoic acid (EPA) found in fish oil can be used to attenuate diabetes associated impairments in cardiomyocyte signalling. Pregnant diabetic rats were administered streptozotocin before receiving EPA or water, and their infants were designated IDM/EPA, IDM/W. We assessed the potential molecular pathway for this effect in the primary cardiac cell from newborn rat hearts. Insulin resistance as determined by diminished GLUT4 translocation following insulin stimulation, the levels of advanced glycation end products (AGEs) and reactive oxygen species were elevated in the neonatal hearts of IDM/W compared with that seen in the offspring born from non-diabetic control animals. Similarly, the receptor of AGEs (RAGE) mRNA levels, reactive oxygen species and the amount of nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) mRNA were higher in the hearts from the IDM/W when compared to that observed in the hearts of offspring born to non-diabetic animals. These deleterious effects of gestational diabetes were significantly decreased in the offspring of diabetic mothers receiving EPA supplementation. Taken together, our data suggest that the EPA in fish oil may improve the impaired signalling and the excessive protein glycation in the cardiac muscles of infants exposed to intrauterine hyperglycemia.

  20. Irbesartan treatment does not influence plasma levels of the advanced glycation end products N(epsilon)(1-carboxymethyl)lysine and N(epsilon)(1-carboxyethyl)lysine in patients with type 2 diabetes and microalbuminuria. A randomized controlled trial

    DEFF Research Database (Denmark)

    Engelen, Lian; Persson, Frederik; Ferreira, Isabel

    2011-01-01

    BACKGROUND: In vitro and animal experiments have shown inhibiting effects of angiotensin receptor blockers (ARBs) on the formation of advanced glycation end products (AGEs), which are known to be involved in the development of cardiovascular complications in diabetes. However, sufficient human da...

  1. Higher plasma soluble Receptor for Advanced Glycation End Products (sRAGE) levels are associated with incident cardiovascular disease and all-cause mortality in type 1 diabetes: a 12-year follow-up study

    DEFF Research Database (Denmark)

    Nin, Johanna W M; Jorsal, Anders; Merces Ferreira, Isabel Maria

    2010-01-01

    To investigate the associations of plasma levels of soluble receptor for advanced glycation end products (sRAGE) with incident cardiovascular disease (CVD) and all-cause mortality in type 1 diabetes and the extent to which any such associations could be explained by endothelial and renal dysfunct...

  2. Effect of Amaranthus on Advanced Glycation End-Products Induced Cytotoxicity and Proinflammatory Cytokine Gene Expression in SH-SY5Y Cells

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    Warisa Amornrit

    2015-09-01

    Full Text Available Amaranthus plants, or spinach, are used extensively as a vegetable and are known to possess medicinal properties. Neuroinflammation and oxidative stress play a major role in the pathogenesis of many neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease. Advanced glycation end-products (AGEs cause cell toxicity in the human neuronal cell line, SH-SY5Y, through an increase in oxidative stress, as shown by reducing cell viability and increasing cell toxicity in a dose-dependent manner. We found that preincubation of SH-SY5Y cells with either petroleum ether, dichloromethane or methanol extracts of A. lividus and A. tricolor dose-dependently attenuated the neuron toxicity caused by AGEs treatment. Moreover, the results showed that A. lividus and A. tricolor extracts significantly downregulated the gene expression of the pro-inflammatory cytokines, TNF-α, IL-1 and IL-6 genes in AGEs-induced cells. We concluded that A. lividus and A. tricolor extracts not only have a neuroprotective effect against AGEs toxicity, but also have anti-inflammatory activity by reducing pro-inflammatory cytokine gene expression. This suggests that Amaranthus may be useful for treating chronic inflammation associated with neurodegenerative disorders.

  3. Extract of Cassiae semen attenuates diabetic nephropathy via inhibition of advanced glycation end products accumulation in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Kim, Young Sook; Jung, Dong Ho; Sohn, Eunjin; Lee, Yun Mi; Kim, Chan-Sik; Kim, Jin Sook

    2014-04-15

    Chronic hyperglycemia leads to the formation of advanced glycation end products (AGEs), which accelerates the development of diabetic complications. Previous studies have shown that extract of Cassiae semen (CS), the seed of Cassia tora, has inhibitory activity on AGEs formation in vitro and reduces transforming growth factor-beta1 (TGF-β1) and extracellular matrix protein expression via inhibition of AGEs-mediated signaling in glomerular mesangial cells. In this study, to examine the preventive effects of CS extract on the development of diabetic nephropathy in vivo, streptozotocin (STZ)-injected diabetic rats were orally administered CS extract (200 mg/kg body weight/day) for 12 weeks. Serum glucose, triglycerides, and total cholesterol in diabetic rats were significantly higher compared to control rats. CS or aminoguanidine (AG) treatment significantly reduced these factors. Proteinuria and creatinine clearance were also significantly decreased in the CS-treated group compared with the untreated diabetic group. The CS-treated group had significantly inhibited COX-2 mRNA and protein, which mediates the symptoms of inflammation in the renal cortex of diabetic rats. Furthermore, histopathological studies of kidney tissue showed that in diabetic rats, AGEs, the receptor for AGEs, TGF-β1, and collagen IV were suppressed by CS treatment. Our data suggest that oral treatment of CS can inhibit the development of diabetic nephropathy via inhibition of AGEs accumulation in STZ-induced diabetic rats. Copyright © 2013 Elsevier GmbH. All rights reserved.

  4. Clinical Implications of High-mobility Group Box-1 (HMGB1) and the Receptor for Advanced Glycation End-products (RAGE) in Cutaneous Malignancy: A Systematic Review.

    Science.gov (United States)

    Nguyen, Austin Huy; Detty, Shannon Q; Agrawal, Devendra K

    2017-01-01

    Inflammation and the immune system play a role in the development and progression of melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). The pro-inflammatory and tumor-promoting effects of the high-mobility group box-1 (HMGB1) protein and the receptor for advanced glycation end products (RAGE) have been investigated in these cutaneous malignancies. The clinical implication of these molecules is not fully described. The National Library of Medicine database was searched for articles addressing the clinical relevance of HMGB1 and RAGE in melanoma, BCC, and SCC. This systematic review includes nine articles, with six summarizing RAGE in cutaneous malignancies and three involving HMGB1. RAGE has been found to be up-regulated in SCC lesions, as well as melanoma. Levels of RAGE were highest in stage IV melanomas. Lower levels of soluble RAGE have been associated with poor overall survival in melanoma. Sporadic extracellular expression of HMGB1 was evident in BCC and SCC lesions, which could be released by necrotic tumor cells. HMGB1 was found to be a prognostic marker in melanoma, and HMGB1 levels were elevated in patients who were non-responders to ipilimumab treatment. HMGB1 and RAGE could serve as potential prognostic markers or therapeutic targets in treating melanoma, BCC, and SCC, but further research regarding the clinical utility of the HMGB1-RAGE axis in cutaneous malignancies is warranted. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  5. Atrial tissue expression of receptor for advanced glycation end-products (RAGE) and atrial fibrosis in patients with mitral valve disease.

    Science.gov (United States)

    Yang, Pil-Sung; Lee, Seung Hyun; Park, Junbeom; Kim, Tae-Hoon; Uhm, Jae-Sun; Joung, Boyoung; Lee, Moon-Hyoung; Chang, Byung-Chul; Pak, Hui-Nam

    2016-10-01

    It has been reported that receptor for advanced glycation end-products (RAGE) plays a significant role in cardiac fibrosis. Nonetheless, the precise relationship between the RAGE and atrial fibrosis has never been studied in humans. The aim of this study was to determine whether degree of atrial fibrosis was associated with atrial tissue expression of RAGE in patients with mitral valve disease (MVD). We collected human left atrial (LA) appendage tissue from 25 patients who underwent mitral valve surgery. We quantified the expression of RAGE and other protein markers by Western blotting and compared these levels with histological evaluations. RAGE expression in the LA appendage tissue was significantly correlated with atrial fibrosis (r=0.681, p=0.001). RAGE expression (regression coefficient [B] 9.49, 95% confidence interval [CI] 4.76-14.2, pRAGE expression was significantly correlated with protein expression of von Willebrand factor (r=0.659, pRAGE expression than those with no, mild, or moderate MS (p=0.013). Patients with MVD and atrial fibrillation (AF) had more severe atrial fibrosis (p=0.024) and higher RAGE expression (p=0.047) than those who remained in sinus rhythm. Atrial tissue expression of RAGE was significantly associated with atrial fibrosis, severe MS, and AF rhythm in patients with MVD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Pioglitazone alleviates inflammation in diabetic mice fed a high-fat diet via inhibiting advanced glycation end-product-induced classical macrophage activation.

    Science.gov (United States)

    Jin, Xian; Liu, Liang; Zhou, Zhong'e; Ge, Junhua; Yao, Tongqing; Shen, Chengxing

    2016-06-01

    Classically activated macrophages (M1) are associated with inflammation in diabetic patients. Inflammation is a known risk factor in diabetes. The present study tested the hypothesis that pioglitazone (PIO) alleviates inflammation in diabetic mice fed a high-fat diet by inhibiting advanced glycation end-product (AGE)-induced classical macrophage activation. It was found that AGE treatment promoted the transcription of pro-inflammatory molecules and M1 surface markers, whereas PIO increased the expression of anti-inflammatory genes and decreased the expression of pro-inflammatory mediators in bone marrow-derived macrophages (BMDMs) in a dose-dependent manner. Furthermore, pretreatment with PIO abrogated the effects of AGE on pro-inflammatory markers and partly inhibited AGE-induced nuclear factor-κB (NF-κB) activation. PIO treatment partly reduced the inflammatory phenotype in diabetic ApoE(-/-) mice, and significantly reduced NF-κB activation in plaques. Therefore, we conclude that PIO blocks classical activation of macrophages and attenuates inflammation in mouse models of diabetes. © 2016 Federation of European Biochemical Societies.

  7. Expression of the Receptor for Advanced Glycation End Products in Epicardial Fat: Link with Tissue Thickness and Local Insulin Resistance in Coronary Artery Disease

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    Elena Dozio

    2016-01-01

    Full Text Available Increased expression of receptor for advanced glycation end products (RAGE in adipose tissue has been associated with inflammation, adipocyte hypertrophy, and impaired insulin signal. Epicardial adipose tissue (EAT, a visceral fat surrounding the myocardium, is potentially involved in the onset/progression of coronary artery disease (CAD. To date, the role of RAGE in EAT has not been explored much. We examined whether the RAGE expression in EAT was associated with EAT adiposity and metabolic dysfunctions normally found in CAD patients. EAT samples were obtained from 33 patients undergoing open-heart surgery. EAT expression of RAGE, GLUT4, adiponenctin, GLO1, HMGB1, TLR-4, and MyD88 was analyzed by microarray. EAT thickness was quantified by echocardiography. Anthropometric measures and clinical parameters were taken. BMI, HOMA-IR, and LAP indices were calculated. With increasing RAGE expression in EAT we observed increases in EAT thickness, reduced expression of GLUT4, adiponectin, and GLO1, and elevations of HMGB1, TLR-4, and MyD88. There were significant correlations between RAGE and EAT thickness and between RAGE and the genes. LAP was higher in patients with increased RAGE expression. Our data suggest that in CAD patients RAGE may be involved in promoting EAT adiposity and metabolic dysfunction, such as impaired insulin signaling.

  8. Advanced glycation end-product (AGE)-albumin from activated macrophage is critical in human mesenchymal stem cells survival and post-ischemic reperfusion injury.

    Science.gov (United States)

    Son, Myeongjoo; Kang, Woong Chol; Oh, Seyeon; Bayarsaikhan, Delger; Ahn, Hyosang; Lee, Jaesuk; Park, Hyunjin; Lee, Sojung; Choi, Junwon; Lee, Hye Sun; Yang, Phillip C; Byun, Kyunghee; Lee, Bonghee

    2017-09-14

    Post-ischemic reperfusion injury (PIRI) triggers an intense inflammatory response which is essential for repair but is also implicated in pathogenesis of post-ischemic remodeling in several organs in human. Stem cell therapy has recently emerged as a promising method for treatment of PIRI in human. However, satisfactory results have not been reported due to severe loss of injected stem cells in PIRI including critical limb ischemia (CLI). For investigating the advanced glycation end-product-albumin (AGE-albumin) from activated macrophages is critical in both muscle cell and stem cell death, we evaluated the recovery of PIRI-CLI by injection of human bone marrow derived mesenchymal stem cells (hBD-MSCs) with or without soluble receptor for AGEs (sRAGE). Our results showed that activated M1 macrophages synthesize and secrete AGE-albumin, which induced the skeletal muscle cell death and injected hBD-MSCs in PIRI-CLI through RAGE increase. Combined injection of sRAGE and hBD-MSCs resulted in enhanced survival of hBD-MSCs and angiogenesis in PIRI-CLI mice. Taken together, AGE-albumin from activated macrophages is critical for both skeletal muscle cell and hBD-MSCs death in PIRI-CLI. Therefore, the inhibition of AGE-albumin from activated macrophages could be a successful therapeutic strategy for treatment of PIRI including CLI with or without stem cell therapy.

  9. Elevated Serum Carboxymethyl-Lysine, an Advanced Glycation End Product, Predicts Severe Walking Disability in Older Women: The Women's Health and Aging Study I

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    Kai Sun

    2012-01-01

    Full Text Available Advanced glycation end products (AGEs have been implicated in the pathogenesis of sarcopenia. Our aim was to characterize the relationship between serum carboxymethyl-lysine (CML, a major circulating AGE, and incident severe walking disability (inability to walk or walking speed <0.4 m/sec over 30 months of followup in 394 moderately to severely disabled women, ≥65 years, living in the community in Baltimore, Maryland (the Women’s Health and Aging Study I. During followup, 154 (26.4% women developed severe walking disability, and 23 women died. Women in the highest quartile of serum CML had increased risk of developing of severe walking disability in a multivariate Cox proportional hazards model, adjusting for age and other potential confounders. Women with elevated serum CML are at an increased risk of developing severe walking disability. AGEs are a potentially modifiable risk factor. Further work is needed to establish a causal relationship between AGEs and walking disability.

  10. Increased expression of the receptor for advanced glycation end products in neurons and astrocytes in a triple transgenic mouse model of Alzheimer's disease.

    Science.gov (United States)

    Choi, Bo-Ryoung; Cho, Woo-Hyun; Kim, Jiyoung; Lee, Hyong Joo; Chung, ChiHye; Jeon, Won Kyung; Han, Jung-Soo

    2014-02-07

    The receptor for advanced glycation end products (RAGE) has been reported to have a pivotal role in the pathogenesis of Alzheimer's disease (AD). This study investigated RAGE levels in the hippocampus and cortex of a triple transgenic mouse model of AD (3xTg-AD) using western blotting and immunohistochemical double-labeling to assess cellular localization. Analysis of western blots showed that there were no differences in the hippocampal and cortical RAGE levels in 10-month-old adult 3xTg-AD mice, but significant increases in RAGE expression were found in the 22- to 24-month-old aged 3xTg-AD mice compared with those of age-matched controls. RAGE-positive immunoreactivity was observed primarily in neurons of aged 3xTg-AD mice with very little labeling in non-neuronal cells, with the notable exception of RAGE presence in astrocytes in the hippocampal area CA1. In addition, RAGE signals were co-localized with the intracellular amyloid precursor protein (APP)/amyloid beta (Aβ) but not with the extracellular APP/Aβ. In aged 3xTg-AD mice, expression of human tau was observed in the hippocampal area CA1 and co-localized with RAGE signals. The increased presence of RAGE in the 3xTg-AD animal model showing critical aspects of AD neuropathology indicates that RAGE may contribute to cellular dysfunction in the AD brain.

  11. The pathological role of advanced glycation end products-downregulated heat shock protein 60 in islet β-cell hypertrophy and dysfunction.

    Science.gov (United States)

    Guan, Siao-Syun; Sheu, Meei-Ling; Yang, Rong-Sen; Chan, Ding-Cheng; Wu, Cheng-Tien; Yang, Ting-Hua; Chiang, Chih-Kang; Liu, Shing-Hwa

    2016-04-26

    Heat shock protein 60 (HSP60) is a mitochondrial chaperone. Advanced glycation end products (AGEs) have been shown to interfere with the β-cell function. We hypothesized that AGEs induced β-cell hypertrophy and dysfunction through a HSP60 dysregulation pathway during the stage of islet/β-cell hypertrophy of type-2-diabetes. We investigated the role of HSP60 in AGEs-induced β-cell hypertrophy and dysfunction using the models of diabetic mice and cultured β-cells. Hypertrophy, increased levels of p27Kip1, AGEs, and receptor for AGEs (RAGE), and decreased levels of HSP60, insulin, and ATP content were obviously observed in pancreatic islets of 12-week-old db/db diabetic mice. Low-concentration AGEs significantly induced the cell hypertrophy, increased the p27Kip1 expression, and decreased the HSP60 expression, insulin secretion, and ATP content in cultured β-cells, which could be reversed by RAGE neutralizing antibody. HSP60 overexpression significantly reversed AGEs-induced hypertrophy, dysfunction, and ATP reduction in β-cells. Oxidative stress was also involved in the AGEs-decreased HSP60 expression in β-cells. Pancreatic sections from diabetic patient showed islet hypertrophy, increased AGEs level, and decreased HSP60 level as compared with normal subject. These findings highlight a novel mechanism by which a HSP60-correlated signaling pathway contributes to the AGEs-RAGE axis-induced β-cell hypertrophy and dysfunction under diabetic hyperglycemia.

  12. Relationships between vitreous levels of soluble receptor for advanced glycation end products (sRAGE) and renal function in patients with diabetic retinopathy.

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    Katagiri, Makiko; Shoji, Jun; Kato, Satoshi; Kitano, Shigehiko; Uchigata, Yasuko

    2017-12-01

    We investigated the relationship between vitreous levels of soluble receptor for advanced glycation end products (sRAGE) and vascular endothelial growth factor (VEGF) and renal function, and correlations between vitreous sRAGE levels and proliferative diabetic retinopathy (PDR) activity. We examined 33 eyes from 33 patients with diabetes mellitus who underwent a vitrectomy (eight patients in the non-PDR [NPDR] group and 25 in the PDR group). Serum creatinine levels and estimated glomerular filtration rate (eGFR) were measured and classified according to the chronic kidney disease (CKD)-staging method. Enzyme-linked immunosorbent assay (ELISA) was performed to quantify vitreous sRAGE and VEGF levels. Vitreous sRAGE levels were significantly higher in PDR group compared to NPDR group (p = 0.00003). Vitreous sRAGE levels were significantly higher in patients with CKD stage 5 (end-stage renal failure or hemodialysis) than in patients with CKD stage 1 or 2 (p renal function, and low vitreous sRAGE levels in patients with PDR were associated with postoperative vitreous hemorrhage. Vitreous sRAGE may be a useful biomarker for renal dysfunction associated with diabetic retinopathy.

  13. Advanced glycation end products promote ChREBP expression and cell proliferation in liver cancer cells by increasing reactive oxygen species.

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    Chen, Hanbei; Li, Yakui; Zhu, Yemin; Wu, Lifang; Meng, Jian; Lin, Ning; Yang, Dianqiang; Li, Minle; Ding, WenJin; Tong, Xuemei; Su, Qing

    2017-08-01

    The aim of the study was to elucidate the mechanism by which advanced glycation end products (AGEs) promote cell proliferation in liver cancer cells.We treated liver cancer HepG2 cells with 200 mg/L AGEs or bovine serum albumin (BSA) and assayed for cell viability, cell cycle, and apoptosis. We performed real-time PCR and Western blot analysis for RNA and protein levels of carbohydrate responsive element-binding protein (ChREBP) in AGEs- or BSA-treated HepG2 cells. We analyzed the level of reactive oxygen species (ROS) in HepG2 cells treated with AGEs or BSA.We found that increased S-phase cell percentage and decreased apoptosis contributed to AGEs-induced liver cancer cell proliferation. Real-time PCR and Western blot analysis showed that AGEs stimulated RNA and protein levels of ChREBP, a transcription factor promoting glycolysis and maintaining cell proliferation in liver cancer cells. Intriguingly, the level of ROS was higher in AGEs-treated liver cancer cells. Treating liver cancer cells with antioxidant N-acetyl cystein (NAC) partly blocked AGEs-induced ChREBP expression and cell proliferation.Our results suggest that the AGEs-ROS-ChREBP pathway plays a critical role in promoting ChREBP expression and liver cancer cell proliferation.

  14. Beneficial effects of banana (Musa sp. var. elakki bale) flower and pseudostem on hyperglycemia and advanced glycation end-products (AGEs) in streptozotocin-induced diabetic rats.

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    Bhaskar, Jamuna J; Shobha, Mysore S; Sambaiah, Kari; Salimath, Paramahans V

    2011-09-01

    Diabetes is a chronic health problem and major cause of death in most of the countries. Diet management plays an important role in controlling diabetes and its complications along with insulin and drugs. We have examined the effect of banana (Musa sp. var. elakki bale) flower and pseudostem on hyperglycemia and advanced glycation end-products (AGEs) in streptozotocin-induced diabetic rats. Our results indicated that banana flower and pseudostem have low glycemic index and have a high content of dietary fiber and antioxidants. Diabetic symptoms like hyperglycemia, polyuria, polyphagia, polydipsia, urine sugar, and body weight were ameliorated in banana flower- and pseudostem-treated rats. Increased glomerular filtration rate in the diabetic group (5.1 ± 0.22 ml/min) was decreased in banana flower-fed (2.5 ± 0.37 ml/min) and pseudostem-fed (3.0 ± 0.45 ml/min) groups and were significant at P banana flower- and pseudostem-fed groups, it was reduced to 9.21 ± 0.32 and 9.29 ± 0.24 μg/mg protein, respectively, and were significant at P banana flower and pseudostem have anti-diabetic and anti-AGEs properties and are beneficial as food supplements for diabetics.

  15. Impact of dietary modification of advanced glycation end products (AGEs) on the hormonal and metabolic profile of women with polycystic ovary syndrome (PCOS).

    Science.gov (United States)

    Tantalaki, Evangelia; Piperi, Christina; Livadas, Sarantis; Kollias, Anastasios; Adamopoulos, Christos; Koulouri, Aikaterini; Christakou, Charikleia; Diamanti-Kandarakis, Evanthia

    2014-01-01

    To investigate the impact of dietary intervention on Advanced Glycation End products (AGEs) intake on the hormonal and metabolic profile in women with polycystic ovary syndrome (PCOS). After baseline evaluation, 23 women with PCOS [mean ± SD, age: 23.4 ± 5.7 years; body mass index (BMI): 26 ± 5.7 kg/m2] underwent the following consecutive 2-month dietary regimens: a hypocaloric diet with ad-libitum AGEs content (Hypo), an isocaloric diet with high AGEs (HA) and an isocaloric diet with low AGEs (LA). Metabolic, hormonal and oxidative stress status was assessed and AGEs levels were determined in all subjects after the completion of each dietary intervention. Serum levels of AGEs, testosterone, oxidative stress, insulin and HOMA-IR index were significantly increased on the HA compared to the Hypo diet and subsequently decreased on the LA diet (compared to HA) (pPCOS. These novel findings support recommendations for a low AGEs dietary content along with lifestyle changes in women with PCOS.

  16. Advanced oxidation protein products induce chondrocyte apoptosis via receptor for advanced glycation end products-mediated, redox-dependent intrinsic apoptosis pathway.

    Science.gov (United States)

    Wu, Qian; Zhong, Zhao-Ming; Zhu, Si-Yuan; Liao, Cong-Rui; Pan, Ying; Zeng, Ji-Huan; Zheng, Shuai; Ding, Ruo-Ting; Lin, Qing-Song; Ye, Qing; Ye, Wen-Bin; Li, Wei; Chen, Jian-Ting

    2016-01-01

    Pro-inflammatory cytokine-induced chondrocyte apoptosis is a primary cause of cartilage destruction in the progression of rheumatoid arthritis (RA). Advanced oxidation protein products (AOPPs), a novel pro-inflammatory mediator, have been confirmed to accumulate in patients with RA. However, the effect of AOPPs accumulation on chondrocyte apoptosis and the associated cellular mechanisms remains unclear. The present study demonstrated that the plasma formation of AOPPs was enhanced in RA rats compared with normal. Then, chondrocyte were treated with AOPPs-modified rat serum albumin (AOPPs-RSA) in vitro. Exposure of chondrocyte to AOPPs activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and increased expression of NADPH oxidase subunits, which was mediated by receptor for advanced glycation end products (RAGE), but not scavenger receptor CD36. Moreover, AOPPs challenge triggered NADPH oxidase-dependent ROS generation which induced mitochondrial dysfunction and endoplasmic reticulum stress resulted in activation of caspase family that eventually lead to apoptosis. Lastly, blockade of RAGE, instead of CD36, largely attenuated these signals. Our study demonstrated first time that AOPPs induce chondrocyte apoptosis via RAGE-mediated and redox-dependent intrinsic apoptosis pathway in vitro. These data implicates that AOPPs may represent a novel pathogenic factor that contributes to RA progression. Targeting AOPPs-triggered cellular mechanisms might emerge as a promising therapeutic option for patients with RA.

  17. High Serum Advanced Glycation End Products Are Associated with Decreased Insulin Secretion in Patients with Type 2 Diabetes: A Brief Report

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    Tsuyoshi Okura

    2017-01-01

    Full Text Available Objective. Advanced glycation end products (AGEs are important in the pathophysiology of type 2 diabetes mellitus (T2DM. They directly cause insulin secretory defects in animal and cell culture models and may promote insulin resistance in nondiabetic subjects. We have developed a highly sensitive liquid chromatography-tandem mass spectrometry method for measuring AGEs in human serum. Here, we use this method to investigate the relationship between AGEs and insulin secretion and resistance in patients with T2DM. Methods. Our study involved 15 participants with T2DM not on medication and 20 nondiabetic healthy participants. We measured the AGE carboxyethyllysine (CEL, carboxymethyllysine (CML, and methyl-glyoxal-hydro-imidazolone (MG-H1. Plasma glucose and insulin were measured in these participants during a meal tolerance test, and the glucose disposal rate was measured during a euglycemic-hyperinsulinemic clamp. Results. CML and CEL levels were significantly higher in T2DM than non-DM participants. CML showed a significant negative correlation with insulin secretion, HOMA-%B, and a significant positive correlation with the insulin sensitivity index in T2DM participants. There was no correlation between any of the AGEs measured and glucose disposal rate. Conclusions. These results suggest that AGE might play a role in the development or prediction of insulin secretory defects in type 2 diabetes.

  18. Receptor for advanced glycation end products involved in lung ischemia reperfusion injury in cardiopulmonary bypass attenuated by controlled oxygen reperfusion in a canine model.

    Science.gov (United States)

    Rong, Jian; Ye, Sheng; Liang, Meng-ya; Chen, Guang-xian; Liu, Hai; Zhang, Jin-Xin; Wu, Zhong-kai

    2013-01-01

    Controlled oxygen reperfusion could protect the lung against ischemia-reperfusion injury in cardiopulmonary bypass (CPB) by downregulating high mobility group box 1 (HMGB1), a high affinity receptor of HMGB1. This study investigated the effect of controlled oxygen reperfusion on receptor for advanced glycation end products (RAGE) expression and its downstream effects on lung ischemia-reperfusion injury. Fourteen canines received CPB with 60 minutes of aortic clamping and cardioplegic arrest followed by 90 minutes of reperfusion. Animals were randomized to receive 80% FiO2 during the entire procedure (control group) or to a test group receiving a controlled oxygen reperfusion protocol. Pathologic changes in lung tissues, RAGE expression, serum interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were evaluated. The lung pathologic scores after 25 and 90 minutes of reperfusion were significantly lower in the test group compared with the control group (p RAGE expression, TNF-α, and IL-6 were downregulated by controlled oxygen treatment (p RAGE might be involved in the lung ischemia-reperfusion injury in canine model of CPB, which was downregulated by controlled oxygen reperfusion.

  19. Cerebral ketone body oxidation is facilitated by a high fat diet enriched with advanced glycation end products in normal and diabetic rats

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    Adriano Martimbianco De Assis

    2016-11-01

    Full Text Available Diabetes mellitus (DM causes important modifications in the availability and use of different energy substrates in various organs and tissues. Similarly, dietary manipulations such as high fat diets also affect systemic energy metabolism. However, how the brain adapts to these situations remains unclear. To investigate these issues, control and alloxan-induced type I diabetic rats were fed either a standard or a high fat diet enriched with advanced glycation end products (AGEs (HAGE diet. The HAGE diet increased their levels of blood ketone bodies, and this effect was exacerbated by DM induction. To determine the effects of diet and/or DM induction on key cerebral bioenergetic parameters, both ketone bodies (β-hydroxybutyric acid and lactate oxidation were measured. In parallel, the expression of Monocarboxylate Transporter 1 (MCT1 and 2 (MCT2 isoforms in hippocampal and cortical slices from rats submitted to these diets was assessed. Ketone body oxidation increased while lactate oxidation decreased in hippocampal and cortical slices in both control and diabetic rats fed a HAGE diet. In parallel, the expression of both MCT1 and MCT2 increased only in the cerebral cortex in diabetic rats fed a HAGE diet. These results suggest that a shift in the preferential cerebral energy substrate utilization in favor of ketone bodies in animals fed a HAGE diet, an effect that, in DM animals, is accompanied by the enhanced expression of the related transporters.

  20. N-butanol extracts of Morinda citrifolia suppress advanced glycation end products (AGE)-induced inflammatory reactions in endothelial cells through its anti-oxidative properties.

    Science.gov (United States)

    Ishibashi, Yuji; Matsui, Takanori; Isami, Fumiyuki; Abe, Yumi; Sakaguchi, Tatsuya; Higashimoto, Yuichiro; Yamagishi, Sho-Ichi

    2017-03-04

    Advanced glycation end products (AGEs), senescent macroprotein derivatives formed during a normal aging process and acceleratedly under diabetic conditions, play a role in atherosclerotic cardiovascular disease. AGEs cause endothelial cell (EC) damage, an initial trigger for atherosclerosis through the interaction with a receptor for AGEs (RAGE). We have previously shown that n-butanol extracts of Morinda citrifolia (noni), a plant belonging to the family Rubiaceae, block the binding of AGEs to RAGE in vitro. In this study, we examined the effects of n-butanol extracts of noni on reactive oxygen species (ROS) generation and inflammatory reactions on AGE-exposed human umbilical vein ECs (HUVECs). HUVECs were treated with 100 μg/ml AGE-bovine serum albumin (AGE-BSA) or non-glycated BSA in the presence or absence of 670 ng/ml n-butanol extracts of noni for 4 h. Then ROS generation and inflammatory and gene expression in HUVECs were evaluated by dihydroethidium staining and real-time reverse transcription-polymerase chain reaction analyses, respectively. THP-1 cell adhesion to HUVECs was measured after 2-day incubation of AGE-BSA or BSA in the presence or absence of 670 ng/ml n-butanol extracts of noni. N-butanol extracts of noni at 670 ng/ml significantly inhibited the AGE-induced ROS generation and RAGE, intercellular adhesion molecule-1 and plasminogen activator inhibitor-1 gene expressions in HUVECs. AGEs significantly increased monocytic THP-1 cell adhesion to HUVECs, which was also prevented by 670 ng/ml n-butanol extracts of noni. The present study demonstrated for the first time that N-butanol extracts of noni could suppress the AGE-induced inflammatory reactions in HUVECs through its anti-oxidative properties via blocking of the interaction of AGEs with RAGE. Inhibition of the AGE-RAGE axis by n-butanol extracts of noni may be a novel nutraceutical strategy for the treatment of cardiovascular disease.

  1. Receptor for advanced glycation end products and its ligand high-mobility group box-1 mediate allergic airway sensitization and airway inflammation.

    Science.gov (United States)

    Ullah, Md Ashik; Loh, Zhixuan; Gan, Wan Jun; Zhang, Vivian; Yang, Huan; Li, Jian Hua; Yamamoto, Yasuhiko; Schmidt, Ann Marie; Armour, Carol L; Hughes, J Margaret; Phipps, Simon; Sukkar, Maria B

    2014-08-01

    The receptor for advanced glycation end products (RAGE) shares common ligands and signaling pathways with TLR4, a key mediator of house dust mite (Dermatophagoides pteronyssinus) (HDM) sensitization. We hypothesized that RAGE and its ligand high-mobility group box-1 (HMGB1) cooperate with TLR4 to mediate HDM sensitization. To determine the requirement for HMGB1 and RAGE, and their relationship with TLR4, in airway sensitization. TLR4(-/-), RAGE(-/-), and RAGE-TLR4(-/-) mice were intranasally exposed to HDM or cockroach (Blatella germanica) extracts, and features of allergic inflammation were measured during the sensitization or challenge phase. Anti-HMGB1 antibody and the IL-1 receptor antagonist Anakinra were used to inhibit HMGB1 and the IL-1 receptor, respectively. The magnitude of allergic airway inflammation in response to either HDM or cockroach sensitization and/or challenge was significantly reduced in the absence of RAGE but not further diminished in the absence of both RAGE and TLR4. HDM sensitization induced the release of HMGB1 from the airway epithelium in a biphasic manner, which corresponded to the sequential activation of TLR4 then RAGE. Release of HMGB1 in response to cockroach sensitization also was RAGE dependent. Significantly, HMGB1 release occurred downstream of TLR4-induced IL-1α, and upstream of IL-25 and IL-33 production. Adoptive transfer of HDM-pulsed RAGE(+/+)dendritic cells to RAGE(-/-) mice recapitulated the allergic responses after HDM challenge. Immunoneutralization of HMGB1 attenuated HDM-induced allergic airway inflammation. The HMGB1-RAGE axis mediates allergic airway sensitization and airway inflammation. Activation of this axis in response to different allergens acts to amplify the allergic inflammatory response, which exposes it as an attractive target for therapeutic intervention. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  2. Advanced glycation end products receptor RAGE controls myocardial dysfunction and oxidative stress in high-fat fed mice by sustaining mitochondrial dynamics and autophagy-lysosome pathway.

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    Yu, Yichi; Wang, Lei; Delguste, Florian; Durand, Arthur; Guilbaud, Axel; Rousselin, Clementine; Schmidt, Ann Marie; Tessier, Frédéric; Boulanger, Eric; Neviere, Remi

    2017-11-01

    Oxidative stress and mitochondrial dysfunction are recognized as major contributors of cardiovascular damage in diabetes and high fat diet (HFD) fed mice. Blockade of receptor for advanced glycation end products (RAGE) attenuates vascular oxidative stress and development of atherosclerosis. We tested whether HFD-induced myocardial dysfunction would be reversed in RAGE deficiency mice, in association with changes in oxidative stress damage, mitochondrial respiration, mitochondrial fission and autophagy-lysosomal pathway. Cardiac antioxidant capacity was upregulated in RAGE - / - mice under normal diet as evidenced by increased superoxide dismutase and sirtuin mRNA expressions. Mitochondrial fragmentation and mitochondrial fission protein Drp1 and Fis1 expressions were increased in RAGE - / - mice. Autophagy-related protein expressions and cathepsin-L activity were increased in RAGE - / - mice suggesting sustained autophagy-lysosomal flux. HFD induced mitochondrial respiration defects, cardiac contractile dysfunction, disrupted mitochondrial dynamics and autophagy inhibition, which were partially prevented in RAGE - / - mice. Our results suggest that cardioprotection against HFD in RAGE - / - mice include reactivation of autophagy, as inhibition of autophagic flux by chloroquine fully abrogated beneficial myocardial effects and its stimulation by rapamycin improved myocardial function in HFD wild type mice. As mitochondrial fission is necessary to mitophagy, increased fragmentation of mitochondrial network in HFD RAGE - / - mice may have facilitated removal of damaged mitochondria leading to better mitochondrial quality control. In conclusion, modulation of RAGE pathway may improve mitochondrial damage and myocardial dysfunction in HFD mice. Attenuation of cardiac oxidative stress and maintenance of healthy mitochondria population ensuring adequate energy supply may be involved in myocardial protection against HFD. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Therapeutic effects of antigen affinity-purified polyclonal anti-receptor of advanced glycation end-product (RAGE) antibodies on cholestasis-induced liver injury in rats.

    Science.gov (United States)

    Xia, Peng; Deng, Qing; Gao, Jin; Yu, Xiaolan; Zhang, Yang; Li, Jingjing; Guan, Wen; Hu, Jianjun; Tan, Quanhui; Zhou, Liang; Han, Wei; Yuan, Yunsheng; Yu, Yan

    2016-05-15

    Cholestasis leads to acute hepatic injury, fibrosis/cirrhosis, inflammation, and duct proliferation. We investigated whether blocking receptor of advanced glycation end-products (RAGE) with polyclonal anti-RAGE antibodies (anti-RAGE) could regulate acute liver injury and fibrosis in a rat bile duct ligation (BDL) model. Male Wister rats received 0.5mg/kg rabbit anti-RAGE or an equal amount of rabbit IgG by subcutaneous injection twice a week after BDL. Samples of liver tissue and peripheral blood were collected at 14 days after BDL. Serum biochemistry and histology were used to analyze the degree of liver injury. Quantitative real-time PCR (qPCR) and immunohistochemical staining were used to further analyze liver injury. Anti-RAGE improved the gross appearance of the liver and the rat survival rate. Liver tissue histology and relevant serum biochemistry indicated that anti-RAGE attenuated liver necrosis, inflammation, liver fibrosis, and duct proliferation in the BDL model. qPCR and western blotting showed significant reductions in interleukin-1β expression levels in the liver by treatment with anti-RAGE. Anti-RAGE also significantly reduced the mRNA levels of α1(1) collagen (Col1α1) and cholesterol 7α-hydroxylase, and the ratio of tissue inhibitor of matrix metalloproteinase-1 to matrix metalloproteinases (MMPs) in the liver. In addition, anti-RAGE regulated the transcriptional level of Col1α1 and MMP-9 in transforming growth factor-β-induced activated LX-2 cells in vitro. Anti-RAGE was found to inhibit hepatic stellate cell proliferation in vivo and in vitro. Therefore, anti-RAGE can protect the liver from injury induced by BDL in rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. High-mobility group box 1 inhibits gastric ulcer healing through Toll-like receptor 4 and receptor for advanced glycation end products.

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    Yuji Nadatani

    Full Text Available High-mobility group box 1 (HMGB1 was initially discovered as a nuclear protein that interacts with DNA as a chromatin-associated non-histone protein to stabilize nucleosomes and to regulate the transcription of many genes in the nucleus. Once leaked or actively secreted into the extracellular environment, HMGB1 activates inflammatory pathways by stimulating multiple receptors, including Toll-like receptor (TLR 2, TLR4, and receptor for advanced glycation end products (RAGE, leading to tissue injury. Although HMGB1's ability to induce inflammation has been well documented, no studies have examined the role of HMGB1 in wound healing in the gastrointestinal field. The aim of this study was to evaluate the role of HMGB1 and its receptors in the healing of gastric ulcers. We also investigated which receptor among TLR2, TLR4, or RAGE mediates HMGB1's effects on ulcer healing. Gastric ulcers were induced by serosal application of acetic acid in mice, and gastric tissues were processed for further evaluation. The induction of ulcer increased the immunohistochemical staining of cytoplasmic HMGB1 and elevated serum HMGB1 levels. Ulcer size, myeloperoxidase (MPO activity, and the expression of tumor necrosis factor α (TNFα mRNA peaked on day 4. Intraperitoneal administration of HMGB1 delayed ulcer healing and elevated MPO activity and TNFα expression. In contrast, administration of anti-HMGB1 antibody promoted ulcer healing and reduced MPO activity and TNFα expression. TLR4 and RAGE deficiency enhanced ulcer healing and reduced the level of TNFα, whereas ulcer healing in TLR2 knockout (KO mice was similar to that in wild-type mice. In TLR4 KO and RAGE KO mice, exogenous HMGB1 did not affect ulcer healing and TNFα expression. Thus, we showed that HMGB1 is a complicating factor in the gastric ulcer healing process, which acts through TLR4 and RAGE to induce excessive inflammatory responses.

  5. Nifedipine inhibits advanced glycation end products (AGEs) and their receptor (RAGE) interaction-mediated proximal tubular cell injury via peroxisome proliferator-activated receptor-gamma activation

    International Nuclear Information System (INIS)

    Matsui, Takanori; Yamagishi, Sho-ichi; Takeuchi, Masayoshi; Ueda, Seiji; Fukami, Kei; Okuda, Seiya

    2010-01-01

    Research highlights: → Nifedipine inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by GW9662, an inhibitor of peroxisome proliferator-activated receptor-γ. → GW9662 treatment alone increased RAGE mRNA levels in tubular cells. → Nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-κB activation and increases in intercellular adhesion molecule-1 and transforming growth factor-β gene expression in tubular cells, all of which were blocked by GW9662. -- Abstract: There is a growing body of evidence that advanced glycation end products (AGEs) and their receptor (RAGE) interaction evokes oxidative stress generation and subsequently elicits inflammatory and fibrogenic reactions, thereby contributing to the development and progression of diabetic nephropathy. We have previously found that nifedipine, a calcium-channel blocker (CCB), inhibits the AGE-induced mesangial cell damage in vitro. However, effects of nifedipine on proximal tubular cell injury remain unknown. We examined here whether and how nifedipine blocked the AGE-induced tubular cell damage. Nifedipine, but not amlodipine, a control CCB, inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-γ (PPARγ). GW9662 treatment alone was found to increase RAGE mRNA levels in tubular cells. Further, nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-κB activation and increases in intercellular adhesion molecule-1 and transforming growth factor-beta gene expression in tubular cells, all of which were blocked by GW9662. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-oxidative and anti-inflammatory agent against AGEs in tubular cells by suppressing RAGE expression via PPARγ activation.

  6. Advanced Glycation End Products Impair Ca2+ Mobilization and Sensitization in Colonic Smooth Muscle Cells via the CAMP/PKA Pathway

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    Ting Yu

    2017-10-01

    Full Text Available Background/Aims: Excessive production of advanced glycation end products (AGEs has been implicated in diabetes-related complications. This study aimed to investigate the mechanism by which AGEs potentially contribute to diabetes-associated colonic dysmotility. Methods: Control and streptozotocin (STZ-induced diabetic groups were treated with aminoguanidine (AG. The colonic transit time and contractility of circular muscle strips was measured. ELISA, immunohistochemistry and western blotting were used to measure Nε-carboxymethyl-lysine (CML levels. Primary cultured colonic smooth muscle cells (SMCs were used in complementary in vitro studies. Results: Diabetic rats showed prolonged colonic transit time, weak contractility of colonic smooth muscle strips, and elevated levels of AGEs in the serum and colon tissues. cAMP levels, protein kinase-A (PKA activities, and inositol 1,4,5-trisphosphate receptor type 3 (IP3R3 phosphorylation were increased in the colon muscle tissues of diabetic rats, whereas RhoA/Rho kinase activity and myosin phosphatase target subunit 1 (MYPT1 phosphorylation were reduced. The inhibition of the production of AGEs (AG treatment reduced these effects. In cultured colonic SMCs, AGE-BSA treatment increased IP3R3 phosphorylation and reduced intracellular Ca2+ concentration, myosin light chain (MLC phosphorylation, RhoA/Rho kinase activity, and MYPT1 phosphorylation. The PKA inhibitor H-89 and anti-RAGE antibody inhibited the AGE-BSA–induced impairment of Ca2+ signaling and cAMP/PKA activation. Conclusion: AGEs/RAGE participate in diabetes-associated colonic dysmotility by interfering with Ca2+ signaling in colonic SMCs through targeting IP3R3-mediated Ca2+ mobilization and RhoA/Rho kinase-mediated Ca2+ sensitization via the cAMP/PKA pathway.

  7. Advanced glycation end products dietary restriction effects on bacterial gut microbiota in peritoneal dialysis patients; a randomized open label controlled trial.

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    Rabi Yacoub

    Full Text Available The modern Western diet is rich in advanced glycation end products (AGEs. We have previously shown an association between dietary AGEs and markers of inflammation and oxidative stress in a population of end stage renal disease (ESRD patients undergoing peritoneal dialysis (PD. In the current pilot study we explored the effects of dietary AGEs on the gut bacterial microbiota composition in similar patients. AGEs play an important role in the development and progression of cardiovascular (CVD disease. Plasma concentrations of different bacterial products have been shown to predict the risk of incident major adverse CVD events independently of traditional CVD risk factors, and experimental animal models indicates a possible role AGEs might have on the gut microbiota population. In this pilot randomized open label controlled trial, twenty PD patients habitually consuming a high AGE diet were recruited and randomized into either continuing the same diet (HAGE, n = 10 or a one-month dietary AGE restriction (LAGE, n = 10. Blood and stool samples were collected at baseline and after intervention. Variable regions V3-V4 of 16s rDNA were sequenced and taxa was identified on the phyla, genus, and species levels. Dietary AGE restriction resulted in a significant decrease in serum Nε-(carboxymethyl lysine (CML and methylglyoxal-derivatives (MG. At baseline, our total cohort exhibited a lower relative abundance of Bacteroides and Alistipes genus and a higher abundance of Prevotella genus when compared to the published data of healthy population. Dietary AGE restriction altered the bacterial gut microbiota with a significant reduction in Prevotella copri and Bifidobacterium animalis relative abundance and increased Alistipes indistinctus, Clostridium citroniae, Clostridium hathewayi, and Ruminococcus gauvreauii relative abundance. We show in this pilot study significant microbiota differences in peritoneal dialysis patients' population, as well as the effects

  8. Up-regulation in receptor for advanced glycation end-products in inflammatory circumstances in bovine coccygeal intervertebral disc specimens in vitro.

    Science.gov (United States)

    Yoshida, Tatsuhiro; Park, Jin Soo; Yokosuka, Kimiaki; Jimbo, Kotaro; Yamada, Kei; Sato, Kimiaki; Takeuchi, Masayoshi; Yamagishi, Sho-Ichi; Nagata, Kensei

    2009-07-01

    This study investigated whether or not the receptor for advanced glycation end-products (RAGE) was up-regulated in inflammatory circumstances and consequently associated with aggrecan content in nucleus pulposus in vitro. To investigate the activation of AGEs-RAGE complex by the irritation of IL-1beta in bovine intervertebral disc (IVD). Although we have demonstrated that the accumulation of AGEs contributed to disc degeneration in human, it may be that acceleration in the AGEs-RAGE complex might be more important, mediated by expression levels of RAGE that increase in inflammatory mediators including IL-1beta in some tissues. Therefore, we investigated, in this study, the correlation if any between IL-1beta and AGEs-RAGE complex in bovine IVD. Samples of bovine coccygeal IVDs were harvested (n = 6). The presence of AGEs and RAGE were identified by immunohistochemistry. Real-time polymerase chain reaction (PCR) was used to quantify the messenger RNA levels of aggrecan after 6 days' stimulation of AGEs. Real-time PCR and immunofluorescein cytochemistry were performed to analyze the expression of RAGE after 2 days' stimulation of IL-1beta. The aggrecan expressions were evaluated by real-time PCR after 2 days' stimulation of combination of AGEs and/or IL-1beta. Immunohistochemical analysis revealed that AGEs and RAGE were localized within the bovine IVDs. AGEs significantly decreased the aggrecan expression in bovine IVD as in human IVD. The RAGE expression was significantly increased by 2 days' stimulation of IL-1beta. The aggrecan expression was decreased by stimulated AGEs and IL-1beta together, although not decreased by stimulated AGEs or IL-1beta separately. This is the first report to show the correlation between IL-1beta and AGEs-RAGE complex in IVD. Our results suggested that the increased RAGE expression in inflammatory circumstances and interaction with AGEs are risk factors in decreasing of aggrecan content in nucleus pulposus.

  9. Advanced Glycation End Products (AGEs Antibody Protects Against AGEs-induced Apoptosis and NF-ĸB p65 Subunit Overexpression in Rat Glomerular Culture

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    Oktavia Rahayu Adianingsih

    2016-11-01

    Full Text Available Advanced glycation end products (AGEs have been thought to be a major cause of diabetic nephropathy (DN. The mechanisms underlying the involvement of AGEs antibody in diabetic nephropathy are not fully understood. The present study was designed to investigate the protective effect of AGEs antibody on AGEs-induced glomerular damage. Isolated glomeruli were pre-incubated either with 10 µg/mL polyclonal anti-AGEs antibody (AGE-pAb or monoclonal anti-Nɜ -carboxymethyl-lysine antibody (CML-mAb as a model of AGEs antibody to block interaction of AGEs with receptor for AGEs (RAGE and incubated afterwards either with 100 µg/mL bovine serum albumin (BSA or AGE-modified bovine serum albumin (AGE-BSA for 48 h. Annexin V/nephrin doublestaining was performed to determine apoptosis. Using immunofluorescence, we found that administration of AGE-BSA not only significantly increased glomerular cells apoptosis and nuclear factor kappa B (NF-ĸB p65 expression, but also reduced expression of nephrin, an important structural and signal molecule of podocytes slit diaphragm. Blocking the interaction of AGE-RAGE with AGEs antibody significantly protected glomerular cells from AGEs-induced apoptosis and NF-ĸB p65 overexpression. We found that AGE-pAb conferred superior protective effect compared with CmL-mAb for the same reduction in apoptosis and NF-ĸB p65 expression. In sharp contrast, CmL-mAb led to preserve expression of podocytes nephrin better than AGE-pAb. These results demonstrate that the antibody against AGEs may be beneficial for preventing the glomerular damage in DN.

  10. Pigment epithelium-derived factor (PEDF) inhibits proximal tubular cell injury in early diabetic nephropathy by suppressing advanced glycation end products (AGEs)-receptor (RAGE) axis.

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    Maeda, Sayaka; Matsui, Takanori; Takeuchi, Masayoshi; Yoshida, Yumiko; Yamakawa, Ryoji; Fukami, Kei; Yamagishi, Sho-ichi

    2011-03-01

    Pigment epithelium-derived factor (PEDF) is a multifunctional glycoprotein with anti-angiogenic and anti-inflammatory properties, and it could block the development and progression of experimental diabetic retinopathy. However, a role for PEDF in early experimental diabetic nephropathy is not fully understood. Advanced glycation end products (AGEs) and their receptor (RAGE) axis stimulates oxidative stress generation and subsequently evokes inflammatory and fibrogenic reactions in renal tubular cells, thereby playing a role in diabetic nephropathy. Therefore, this study investigated whether PEDF could prevent AGE-elicited tubular cell injury in early diabetic nephropathy. Human proximal tubular cells were incubated with or without AGE-bovine serum albumin in the presence or absence of PEDF. Streptozotocin-induced diabetic rats were treated with or without intravenous injection of PEDF for 4 weeks. Gene expression was analyzed by quantitative real-time reverse transcription-polymerase chain reactions. Reactive oxygen species (ROS) was measured with dihydroethidium staining. PEDF or antibodies raised against RAGE inhibited the AGE-induced RAGE gene expression and subsequently reduced ROS generation, monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-β (TGF-β), fibronectin and type IV collagen mRNA levels in proximal tubular cells. RAGE gene expression, ROS generation and MCP-1 and TGF-β mRNA levels were significantly increased in diabetic kidney, which were suppressed by administration of PEDF. Our present data suggest that PEDF could play a protective role against tubular injury in diabetic nephropathy by attenuating the deleterious effects of AGEs via down-regulation of RAGE expression. Administration of PEDF may offer a promising strategy for halting the development of diabetic nephropathy. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Glucagon-like peptide-1 counteracts the detrimental effects of Advanced Glycation End-Products in the pancreatic beta cell line HIT-T 15

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    Puddu, A.; Storace, D.; Durante, A.; Odetti, P.; Viviani, G.L.

    2010-01-01

    Research highlights: → GLP-1 prevents AGEs-induced cell death. → GLP-1 prevents AGEs-induced oxidative stress. → GLP-1 ameliorated AGEs-induced cell dysfunction. → GLP-1 attenuates AGEs-induced RAGE increment. → GLP-1 counteracts AGEs-induced pancreatic cell death and dysfunction. -- Abstract: Advanced Glycation End-Products (AGEs), a group of compounds resulting from the non-enzymatic reaction of reducing sugars with the free amino group of proteins, are implicated in diabetic complications. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T 15 to high concentrations of AGEs significantly decreases cell proliferation and insulin secretion, and affects transcription factors regulating insulin gene transcription. The glucagon-like peptide-1 (GLP-1) is an incretin hormone that increases proinsulin biosynthesis, stimulates insulin secretion, and improves pancreatic beta-cell viability. The aim of this work was to investigate the effects of GLP-1 on the function and viability of HIT-T 15 cells cultured with AGEs. HIT-T 15 cells were cultured for 5 days in presence of AGEs alone, or supplemented with 10 nmol/l GLP-1. Cell viability, insulin secretion, redox balance, and expression of the AGEs receptor (RAGE) were then determined. The results showed that GLP-1 protected beta cell against AGEs-induced cell death preventing both apoptosis and necrosis. Moreover, addition of GLP-1 to the AGEs culture medium restored the redox balance, improved the responsiveness to glucose, and attenuated AGEs-induced RAGE expression. These findings provide evidence that GLP-1 protects beta cells from the dangerous effects of AGEs.

  12. Association of the Receptor for Advanced Glycation End Products Gene Polymorphisms and Circulating RAGE Levels with Diabetic Retinopathy in the Chinese Population

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    Li Yang

    2013-01-01

    Full Text Available Objectives. This study investigated the association between polymorphisms in the receptor for advanced glycation end products (RAGE gene and the susceptibility to diabetic retinopathy (DR in a Chinese population and identified a correlation between serum-soluble RAGE (sRAGE levels and DR risk. Materials and Methods. We enrolled 1040 patients with type 2 diabetes mellitus: 372 patients with DR and 668 without retinopathy (NDR. All polymorphisms were genotyped by time-of-flight mass spectrometry. Serum levels of sRAGE were assayed by enzyme-linked immunosorbent assays. The interaction of SNPs was analyzed by multifactor dimensionality reduction (MDR. Results. The frequency of the SS genotype for the G82S polymorphism was 12.4% in the DR group and 6.6% in the NDR group; this difference was significant. G82S was associated with sRAGE levels. Specifically, after adjustments for age, sex, duration, and glucose metabolism, serum sRAGE levels were significantly higher in DR subjects with the S/S genotype than in NDR subjects in general. In the DR group, subjects with the G/S genotype had lower sRAGE levels than subjects with the G/G or S/S genotype (P<0.01. The best multilocus genetic interaction model was assessed using the MDR method; 2184A/G, 1704G/T, G82S, and −429T/C were identified. Conclusions. The findings suggest that the G82S polymorphism in the RAGE gene is associated with DR risk, and G82S was associated with circulating levels of sRAGE. The mechanism by which G82S polymorphism modulates the sRAGE levels remains to be elucidated.

  13. Astaxanthin and Corni Fructus protect against diabetes-induced oxidative stress, inflammation, and advanced glycation end product in livers of streptozotocin-induced diabetic rats.

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    Park, Chan Hum; Xu, Feng Hao; Roh, Seong-Soo; Song, Yeong Ok; Uebaba, Kazuo; Noh, Jeong Sook; Yokozawa, Takako

    2015-03-01

    This study was conducted to compare the protective effects of astaxanthin (ASX) with Corni Fructus (CF) against diabetes-induced pathologies such as oxidative stress-induced inflammation and advanced glycation end product (AGE) formation in the liver of type 1 diabetic rats. ASX (50 mg/kg body weight/day) or CF (200 mg/kg body weight/day) was orally administered every day for 18 days to streptozotocin (STZ)-induced diabetic rats, and their effects were compared with nondiabetic and diabetic control rats. The administration of CF, but not ASX, decreased both the elevated serum and hepatic glucose concentration in diabetic rats. In diabetic rats, increased levels of AGE, reactive oxygen species, and lipid peroxidation were significantly decreased by treatment with both ASX and CF in the liver of diabetic rats. STZ treatment markedly augmented the protein expressions of AGE, and both ASX and CF efficiently attenuated these increases in hepatic protein expressions. In addition, oxidative stress and proinflammatory protein expressions were upregulated in the diabetic rats. On the contrary, these upregulations of protein expressions were decreased by the administration of ASX or CF. These results suggest that the inhibitory effect of ASX on diabetes-induced hepatic dysfunction could be derived from the blocking of AGE formation and further anti-inflammation and that CF exhibited beneficial effects through the attenuation of hyperglycemia, and thus the inhibition of AGE formation and the inflammatory responses. Therefore, ASX as well as CF may help prevent ongoing diabetes-induced hepatic injury.

  14. The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS).

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    Kim, Tae Nyun; Park, Man Sik; Lee, Eun Joo; Chung, Hye Soo; Yoo, Hye Jin; Kang, Hyun Joo; Song, Wook; Baik, Sei Hyun; Choi, Kyung Mook

    2018-03-01

    Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging-related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women. This cross-sectional study included a 390-participant, nondiabetic subcohort recruited within the framework of the Korean Sarcopenic Obesity Study, an ongoing prospective cohort study. Low muscle mass was defined based on the distribution of appendicular skeletal muscle mass divided by body mass index, as proposed by the Foundation for the National Institutes Sarcopenia Project. Serum sRAGE levels were significantly lower in participants with low muscle mass than in participants without low muscle mass (0.76 [0.60-1.00] ng/mL vs 0.87 [0.67-1.15] ng/mL, P = .005). In age- and sex-adjusted correlation analyses, appendicular skeletal muscle mass divided by body mass index was associated with sRAGE (r = 0.109, P = .037). Furthermore, decreased circulating levels of sRAGE are independently associated with low muscle mass (odds ratio = 0.254, P = .002) after adjusting for confounding factors, including insulin resistance and inflammatory markers. The present study shows that a low circulating level of sRAGE may be an independent risk factor for the presence of low muscle mass. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Fibroblast growth factor 21 protects mouse brain against D-galactose induced aging via suppression of oxidative stress response and advanced glycation end products formation.

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    Yu, Yinhang; Bai, Fuliang; Wang, Wenfei; Liu, Yaonan; Yuan, Qingyan; Qu, Susu; Zhang, Tong; Tian, Guiyou; Li, Siming; Li, Deshan; Ren, Guiping

    2015-06-01

    Fibroblast growth factor 21 (FGF21) is a hormone secreted predominantly in the liver, pancreas and adipose tissue. Recently, it has been reported that FGF21-Transgenic mice can extend their lifespan compared with wild type counterparts. Thus, we hypothesize that FGF21 may play some roles in aging of organisms. In this study d-galactose (d-gal)-induced aging mice were used to study the mechanism that FGF21 protects mice from aging. The three-month-old Kunming mice were subcutaneously injected with d-gal (180mg·kg(-1)·d(-1)) for 8weeks and administered simultaneously with FGF21 (1, 2 or 5mg·kg(-1)·d(-1)). Our results showed that administration of FGF21 significantly improved behavioral performance of d-gal-treated mice in water maze task and step-down test, reduced brain cell damage in the hippocampus, and attenuated the d-gal-induced production of MDA, ROS and advanced glycation end products (AGEs). At the same time, FGF21 also markedly renewed the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and total anti-oxidation capability (T-AOC), and decreased the enhanced total cholinesterase (TChE) activity in the brain of d-gal-treated mice. The expression of aldose reductase (AR), sorbitol dehydrogenase (SDH) and member-anchored receptor for AGEs (RAGE) declined significantly after FGF21 treatment. Furthermore, FGF21 suppressed inflamm-aging by inhibiting IκBα degradation and NF-κB p65 nuclear translocation. The expression levels of pro-inflammatory cytokines, such as TNF-α and IL-6, decreased significantly. In conclusion, these results suggest that FGF21 protects the aging mice brain from d-gal-induced injury by attenuating oxidative stress damage and decreasing AGE formation. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Effects of methanolic extracts from edible plants on endogenous secretory receptor for advanced glycation end products induced by the high glucose incubation in human endothelial cells.

    Science.gov (United States)

    Okada, Yoshinori; Okada, Mizue

    2015-01-01

    In diabetic populations, endogenous secretory receptor for advanced glycation end products (esRAGE) levels may be related to the degree of diabetic complications or to the protection from diabetic complications. We investigated the impact of 29 methanolic extracts from edible plants on esRAGE production in human umbilical vein endothelial cells (HUVECs) cultured in high (4.5 g/L) glucose. Edible plants were minced, and extracts were obtained with methanol overnight. The methanolic extracts from 29 edible plants were evaporated in a vacuum. For screening study purposes, HUVECs were seeded in culture dishes (1.5 × 10(5) cells). Then, HUVECs were incubated with 1 g/L or 4.5 g/L of glucose in SFM CS-C medium treated with methanolic extracts from edible plants (MEEP) for 96 h. Determination of esRAGE production in the cell culture-derived supernatants was performed by colorimetric ELISA. The 8-hydroxydeoxyguanosine (8-OHdG) level was determined by using the 8-OHdG Check ELISA kit. Peroxynitrite-dependent oxidation of 2', 7'-dichlorodihydrofluorescein to 2', 7'-dichlorofluorescein was estimated based on the method described by Crow. Because MEEP were methanolic extracts, we measured their total phenolic content (TPC). TPC was measured with a modified version of the Folin-Ciocalteu method. The results showed eight extracts increased esRAGE production. The extract from white radish sprouts showed the highest esRAGE production activity, and then eggplant, carrot peel, young sweet corn, Jew's marrow, broad bean, Japanese radish and cauliflower. In order to understand the mechanism of esRAGE production, the eight extracts were examined for DNA damage, peroxynitrite scavenging activity, and TPC in correlation with their esRAGE production. The results showed esRAGE production correlates with the peroxynitrite level and TPC. This study supports the utilization of these eight extracts in folk medicine for improved treatment of diabetic complications.

  17. S100A14 stimulates cell proliferation and induces cell apoptosis at different concentrations via receptor for advanced glycation end products (RAGE.

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    Qing'e Jin

    Full Text Available S100A14 is an EF-hand containing calcium-binding protein of the S100 protein family that exerts its biological effects on different types of cells. However, exact extracellular roles of S100A14 have not been clarified yet. Here we investigated the effects of S100A14 on esophageal squamous cell carcinoma (ESCC cell lines. Results demonstrated that low doses of extracellular S100A14 stimulate cell proliferation and promote survival in KYSE180 cells through activating ERK1/2 MAPK and NF-κB signaling pathways. Immunoprecipitation assay showed that S100A14 binds to receptor for advanced glycation end products (RAGE in KYSE180 cells. Inhibition of RAGE signaling by different approaches including siRNA for RAGE, overexpression of a dominant-negative RAGE construct or a RAGE antagonist peptide (AmphP significantly blocked S100A14-induced effects, suggesting that S100A14 acts via RAGE ligation. Furthermore, mutation of the N-EF hand of S100A14 (E39A, E45A virtually reduced 10 µg/ml S100A14-induced cell proliferation and ERK1/2 activation. However, high dose (80 µg/ml of S100A14 causes apoptosis via the mitochondrial pathway with activation of caspase-3, caspase-9, and poly(ADP-ribose polymerase. High dose S100A14 induces cell apoptosis is partially in a RAGE-dependent manner. This is the first study to demonstrate that S100A14 binds to RAGE and stimulates RAGE-dependent signaling cascades, promoting cell proliferation or triggering cell apoptosis at different doses.

  18. DNA Advanced Glycation End Products (DNA-AGEs) Are Elevated in Urine and Tissue in an Animal Model of Type 2 Diabetes.

    Science.gov (United States)

    Jaramillo, Richard; Shuck, Sarah C; Chan, Yin S; Liu, Xueli; Bates, Steven E; Lim, Punnajit P; Tamae, Daniel; Lacoste, Sandrine; O'Connor, Timothy R; Termini, John

    2017-02-20

    More precise identification and treatment monitoring of prediabetic/diabetic individuals will require additional biomarkers to complement existing diagnostic tests. Candidates include hyperglycemia-induced adducts such as advanced glycation end products (AGEs) of proteins, lipids, and DNA. The potential for DNA-AGEs as diabetic biomarkers was examined in a longitudinal study using the Lepr db/db animal model of metabolic syndrome. The DNA-AGE, N 2 -(1-carboxyethyl)-2'-deoxyguanosine (CEdG) was quantified by mass spectrometry using isotope dilution from the urine and tissue of hyperglycemic and normoglycemic mice. Hyperglycemic mice (fasting plasma glucose, FPG, ≥ 200 mg/dL) displayed a higher median urinary CEdG value (238.4 ± 112.8 pmol/24 h) than normoglycemic mice (16.1 ± 11.8 pmol/24 h). Logistic regression analysis revealed urinary CEdG to be an independent predictor of hyperglycemia. Urinary CEdG was positively correlated with FPG in hyperglycemic animals and with HbA1c for all mice. Average tissue-derived CEdG was also higher in hyperglycemic mice (18.4 CEdG/10 6 dG) than normoglycemic mice (4.4 CEdG/10 6 dG). Urinary CEdG was significantly elevated in Lepr db/db mice relative to Lepr wt/wt , and tissue CEdG values increased in the order Lepr wt/wt < Lepr wt/db < Lepr db/db . These data suggest that urinary CEdG measurement may provide a noninvasive quantitative index of glycemic status and augment existing biomarkers for the diagnosis and monitoring of diabetes.

  19. Accumulation of advanced glycation end products evaluated by skin autofluorescence and incident frailty in older adults from the Bordeaux Three-City cohort.

    Science.gov (United States)

    Pilleron, Sophie; Rajaobelina, Kalina; Tabue Teguo, Maturin; Dartigues, Jean-François; Helmer, Catherine; Delcourt, Cécile; Rigalleau, Vincent; Féart, Catherine

    2017-01-01

    We analyzed the cross-sectional and prospective relationships between the accumulation of advanced glycation end products (AGE), assessed by skin autofluorescence (AF) and frailty and its components. A total of 423 participants of the Bordeaux sample of the Three-City study 75 years of age or older in 2009-2010 were included in the cross-sectional analysis. Among them, 255 initially non-frail participants were re-examined 4 years later. Skin AF (arbitrary units (AU)) was measured using the AGE Reader. Frailty was defined using Fried's criteria. Associations were assessed with logistic regression models. Mean skin AF at baseline was 2.81 ±0.68 AU and 16.8% participants were frail. Adjusted for sociodemographic and health characteristics, skin AF was associated neither with prevalent frailty as a whole (Odds Ratio (OR) = 1.2; 95% Confidence Interval: 0.8-1.9) nor with any of its components. Among 255 non-frail participants, 32 became frail over 4 years. In multivariate analyses, skin AF was not associated with incident frailty as a whole (OR = 1.0; 0.5-2.0) but with a doubled risk of incident exhaustion (OR = 2.0; 1.2-3.6) and low energy expenditure (OR = 2.0; 1.1-3.7). No association was observed with other criteria. In French older community-dwellers aged 75 years and over, the accumulation of AGEs evaluated by skin AF was not associated with prevalent or incident frailty but with the 4-year risk of exhaustion and low energy expenditure. Further studies with larger samples are needed to confirm our results.

  20. Association of Advanced Glycation End Products with coronary Artery Calcification in Japanese Subjects with Type 2 Diabetes as Assessed by Skin Autofluorescence.

    Science.gov (United States)

    Hangai, Mari; Takebe, Noriko; Honma, Hiroyuki; Sasaki, Atsumi; Chida, Ai; Nakano, Rieko; Togashi, Hirobumi; Nakagawa, Riyuki; Oda, Tomoyasu; Matsui, Mizue; Yashiro, Satoshi; Nagasawa, Kan; Kajiwara, Takashi; Takahashi, Kazuma; Takahashi, Yoshihiko; Satoh, Jo; Ishigaki, Yasushi

    2016-10-01

    Advanced glycation end products (AGE) are considered to be among the critical pathogenic factors involved in the progression of diabetic complications. Skin autofluorescence (AF), a noninvasive measurement of AGE accumulation, has been recognized as a useful and convenient marker for diabetic vascular diseases in Caucasians. This study aimed to evaluate the association of tissue AGE, assessed using skin AF, with coronary artery calcification in Japanese subjects with type 2 diabetes. In total, 122 Japanese subjects with type 2 diabetes enrolled in this cross-sectional study underwent multi-slice computed tomography for total coronary artery calcium scores (CACS) estimation and examination with a skin AF reader. Skin AF positively correlated with age, sex, diabetes duration, pulse wave velocity, systolic blood pressure, serum creatinine, and CACS. In addition, skin AF results negatively correlated with BMI, eGFR, and serum C-peptide concentration. According to multivariate analysis, age and systolic blood pressure showed strong positive correlation and eGFR showed negative correlation with skin AF values. Multiple linear regression analyses revealed a significant positive correlation between skin AF values and logCACS, independent of age, sex, diabetes duration, HbA1c, BMI, IMT, and blood pressure. However, skin AF showed no association with serum levels of AGE, such as Nε-(carboxymethyl) lysine and 3-deoxyglucosone. Skin AF results positively correlated with CACS in Japanese subjects with type 2 diabetes. This result indicates that AGE plays a role in the pathogenesis of diabetic macrovascular disease. Measurement of skin AF values may be useful for assessing the severity of diabetic complications in Japanese subjects.

  1. Accumulation of advanced glycation end products evaluated by skin autofluorescence and incident frailty in older adults from the Bordeaux Three-City cohort.

    Directory of Open Access Journals (Sweden)

    Sophie Pilleron

    Full Text Available We analyzed the cross-sectional and prospective relationships between the accumulation of advanced glycation end products (AGE, assessed by skin autofluorescence (AF and frailty and its components.A total of 423 participants of the Bordeaux sample of the Three-City study 75 years of age or older in 2009-2010 were included in the cross-sectional analysis. Among them, 255 initially non-frail participants were re-examined 4 years later. Skin AF (arbitrary units (AU was measured using the AGE Reader. Frailty was defined using Fried's criteria. Associations were assessed with logistic regression models.Mean skin AF at baseline was 2.81 ±0.68 AU and 16.8% participants were frail. Adjusted for sociodemographic and health characteristics, skin AF was associated neither with prevalent frailty as a whole (Odds Ratio (OR = 1.2; 95% Confidence Interval: 0.8-1.9 nor with any of its components. Among 255 non-frail participants, 32 became frail over 4 years. In multivariate analyses, skin AF was not associated with incident frailty as a whole (OR = 1.0; 0.5-2.0 but with a doubled risk of incident exhaustion (OR = 2.0; 1.2-3.6 and low energy expenditure (OR = 2.0; 1.1-3.7. No association was observed with other criteria.In French older community-dwellers aged 75 years and over, the accumulation of AGEs evaluated by skin AF was not associated with prevalent or incident frailty but with the 4-year risk of exhaustion and low energy expenditure. Further studies with larger samples are needed to confirm our results.

  2. Association between the RAGE (receptor for advanced glycation end-products -374T/A gene polymorphism and diabetic retinopathy in T2DM

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    Dan Tao

    Full Text Available Summary Objective: Interaction between advanced glycation end-products (AGEs and receptor for AGEs (RAGE in cells could affect both extracellular and intracellular structure and function, which plays a pivotal role in diabetic microvascular complications. The results from previous epidemiological studies on the association between RAGE gene -374T/A polymorphism and diabetic retinopathy (DR risk were inconsistent. Thus, we conducted this meta-analysis to summarize the possible association between RAGE -374T/A polymorphism and DR risk. Method: We searched all relevant articles on the association between RAGE -374T/A polymorphism and DR risk from PubMed, Cochrane Library, ScienceDirect, Wanfang, VIP and Chinese National Knowledge Infrastructure (CNKI web databases up to August 2016. Odds ratio (OR with 95% confidence interval (CI were calculated to assess those associations. All analyses were performed using the Review Manager software. Results: Nine case-control studies, including 1,705 DR cases and 2,236 controls were enrolled, and the results showed that the A allele of RAGE -374T/A polymorphism was significantly associated with increased DR risk in dominant model (TA/AA vs. TT: OR=1.22, 95CI 1.05-1.41, p=0.006 and heterozygote model (TA vs. TT: OR=1.26, 95CI 1.07-1.47, p=0.005. The subgroup analysis by ethnicity showed that significantly increased DR risk was found in both Asian and Caucasian populations. Conclusion: This meta-analysis reveals that the A allele of RAGE -374T/A polymorphism probably increase DR risk.

  3. Nifedipine inhibits advanced glycation end products (AGEs) and their receptor (RAGE) interaction-mediated proximal tubular cell injury via peroxisome proliferator-activated receptor-gamma activation

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Takanori [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan); Yamagishi, Sho-ichi, E-mail: shoichi@med.kurume-u.ac.jp [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume (Japan); Takeuchi, Masayoshi [Department of Pathophysiological Science, Faculty of Pharmaceutical Science, Hokuriku University, Kanazawa (Japan); Ueda, Seiji; Fukami, Kei; Okuda, Seiya [Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

    2010-07-23

    Research highlights: {yields} Nifedipine inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma}. {yields} GW9662 treatment alone increased RAGE mRNA levels in tubular cells. {yields} Nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-{kappa}B activation and increases in intercellular adhesion molecule-1 and transforming growth factor-{beta} gene expression in tubular cells, all of which were blocked by GW9662. -- Abstract: There is a growing body of evidence that advanced glycation end products (AGEs) and their receptor (RAGE) interaction evokes oxidative stress generation and subsequently elicits inflammatory and fibrogenic reactions, thereby contributing to the development and progression of diabetic nephropathy. We have previously found that nifedipine, a calcium-channel blocker (CCB), inhibits the AGE-induced mesangial cell damage in vitro. However, effects of nifedipine on proximal tubular cell injury remain unknown. We examined here whether and how nifedipine blocked the AGE-induced tubular cell damage. Nifedipine, but not amlodipine, a control CCB, inhibited the AGE-induced up-regulation of RAGE mRNA levels in tubular cells, which was prevented by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}). GW9662 treatment alone was found to increase RAGE mRNA levels in tubular cells. Further, nifedipine inhibited the AGE-induced reactive oxygen species generation, NF-{kappa}B activation and increases in intercellular adhesion molecule-1 and transforming growth factor-beta gene expression in tubular cells, all of which were blocked by GW9662. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-oxidative and anti-inflammatory agent against AGEs in tubular cells by suppressing RAGE expression

  4. Aliskiren attenuates bleomycin-induced pulmonary fibrosis in rats: focus on oxidative stress, advanced glycation end products, and matrix metalloproteinase-9.

    Science.gov (United States)

    Abuelezz, Sally A; Hendawy, Nevien; Osman, Wesam M

    2016-08-01

    Pulmonary fibrosis is a progressive lung disorder with high mortality rate and limited successful treatment. This study was designed to assess the potential anti-oxidant and anti-fibrotic effects of aliskiren (Alsk) during bleomycin (BLM)-induced pulmonary fibrosis. Male Wistar rats were used as control untreated or treated with the following: a single dose of 2.5 mg/kg of BLM endotracheally and BLM and Alsk (either low dose 30 mg/kg/day or high dose 60 mg/kg/day), and another group was given Alsk 60 mg/kg/day alone. Alsk was given by gavage. Alsk anti-oxidant and anti-fibrotic effects were assessed. BLM significantly increased relative lung weight and the levels of lactate dehydrogenase and total and differential leucocytic count in bronchoalveolar lavage that was significantly ameliorated by high-dose Alsk treatment. As markers of oxidative stress, BLM caused a significant increase in the levels of lipid peroxides and nitric oxide accompanied with a significant decrease of superoxide dismutase and glutathione transferase enzymes. High-dose Alsk treatment restored these markers toward normal values. Alsk counteracted the overexpression of advanced glycation end products, matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinases-1 in lung tissue induced by BLM. Fibrosis assessed by measuring hydroxyproline content, which markedly increased in the BLM group, was also significantly reduced by Alsk. These were confirmed by histopathological and immunohistochemical examination which revealed that Alsk attenuates signs of pulmonary fibrosis and decreased the overexpressed MMP-9 and transforming growth factor β1. Collectively, these findings indicate that Alsk has a potential anti-fibrotic effect beside its anti-oxidant activity.

  5. High-Mobility Group Box 1 Inhibits Gastric Ulcer Healing through Toll-Like Receptor 4 and Receptor for Advanced Glycation End Products

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    Nadatani, Yuji; Watanabe, Toshio; Tanigawa, Tetsuya; Ohkawa, Fumikazu; Takeda, Shogo; Higashimori, Akira; Sogawa, Mitsue; Yamagami, Hirokazu; Shiba, Masatsugu; Watanabe, Kenji; Tominaga, Kazunari; Fujiwara, Yasuhiro; Takeuchi, Koji; Arakawa, Tetsuo

    2013-01-01

    High-mobility group box 1 (HMGB1) was initially discovered as a nuclear protein that interacts with DNA as a chromatin-associated non-histone protein to stabilize nucleosomes and to regulate the transcription of many genes in the nucleus. Once leaked or actively secreted into the extracellular environment, HMGB1 activates inflammatory pathways by stimulating multiple receptors, including Toll-like receptor (TLR) 2, TLR4, and receptor for advanced glycation end products (RAGE), leading to tissue injury. Although HMGB1’s ability to induce inflammation has been well documented, no studies have examined the role of HMGB1 in wound healing in the gastrointestinal field. The aim of this study was to evaluate the role of HMGB1 and its receptors in the healing of gastric ulcers. We also investigated which receptor among TLR2, TLR4, or RAGE mediates HMGB1’s effects on ulcer healing. Gastric ulcers were induced by serosal application of acetic acid in mice, and gastric tissues were processed for further evaluation. The induction of ulcer increased the immunohistochemical staining of cytoplasmic HMGB1 and elevated serum HMGB1 levels. Ulcer size, myeloperoxidase (MPO) activity, and the expression of tumor necrosis factor α (TNFα) mRNA peaked on day 4. Intraperitoneal administration of HMGB1 delayed ulcer healing and elevated MPO activity and TNFα expression. In contrast, administration of anti-HMGB1 antibody promoted ulcer healing and reduced MPO activity and TNFα expression. TLR4 and RAGE deficiency enhanced ulcer healing and reduced the level of TNFα, whereas ulcer healing in TLR2 knockout (KO) mice was similar to that in wild-type mice. In TLR4 KO and RAGE KO mice, exogenous HMGB1 did not affect ulcer healing and TNFα expression. Thus, we showed that HMGB1 is a complicating factor in the gastric ulcer healing process, which acts through TLR4 and RAGE to induce excessive inflammatory responses. PMID:24244627

  6. Circulating levels and dietary intake of the advanced glycation end-product marker carboxymethyl lysine in chronic kidney disease patients on conservative predialysis therapy: a pilot study.

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    Piroddi, Marta; Palazzetti, Ingrid; Quintaliani, Giuseppe; Pilolli, Francesca; Montaldi, Massimiliano; Valentina, Viola; Libetta, Carmelo; Galli, Francesco

    2011-07-01

    Advanced glycation end-products (AGEs) are proposed to influence inflammatory pathways and cardiovascular risk in chronic kidney disease (CKD). Dietary AGEs are believed to sustain circulating levels and toxicity in this condition. We investigated this aspect in a cross-sectional pilot study measuring levels of the AGE marker carboxymethyl lysine (CML) and fluorescent AGEs in the blood of pre-dialysis patients with CKD and hemodialysis (HD) patients (n = 10 each), and in a group of matched healthy controls (Ctr). Plasma CML was measured by immuno-dot blot and fluorescent AGEs were determined by high-performance liquid chromatography (HPLC) analysis measuring the fluorescence of the cross-link pentosidine. The dietary intake of CML was assessed by dietary recall to trace total AGE intake in patients with CKD and the Ctr group. All the subjects included in the study were assessed for dietary intake while maintaining their usual diet. Main exclusion criteria for patients with CKD and HD were severe protein-caloric malnutrition and inflammation (measured by high sensitivity C-reactive protein and interleukin-6 levels). Plasma CML, as well as free and protein-bound fluorescent AGEs, significantly increased in CKD and even more in HD patients than that of the Ctr group. In patients with CKD, the average dietary intake of CML was less than half than that of the Ctr group (6 vs. 13 MU/day) and the lowered protein intake adopted spontaneously by these patients appear to explain this finding. The results show that the intake of CML does not affect circulating levels of this as well as of other AGEs, in well nourished predialysis CKD patients. Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  7. Advanced glycation end products dietary restriction effects on bacterial gut microbiota in peritoneal dialysis patients; a randomized open label controlled trial.

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    Yacoub, Rabi; Nugent, Melinda; Cai, Weijin; Nadkarni, Girish N; Chaves, Lee D; Abyad, Sham; Honan, Amanda M; Thomas, Shruthi A; Zheng, Wei; Valiyaparambil, Sujith A; Bryniarski, Mark A; Sun, Yijun; Buck, Michael; Genco, Robert J; Quigg, Richard J; He, John C; Uribarri, Jaime

    2017-01-01

    The modern Western diet is rich in advanced glycation end products (AGEs). We have previously shown an association between dietary AGEs and markers of inflammation and oxidative stress in a population of end stage renal disease (ESRD) patients undergoing peritoneal dialysis (PD). In the current pilot study we explored the effects of dietary AGEs on the gut bacterial microbiota composition in similar patients. AGEs play an important role in the development and progression of cardiovascular (CVD) disease. Plasma concentrations of different bacterial products have been shown to predict the risk of incident major adverse CVD events independently of traditional CVD risk factors, and experimental animal models indicates a possible role AGEs might have on the gut microbiota population. In this pilot randomized open label controlled trial, twenty PD patients habitually consuming a high AGE diet were recruited and randomized into either continuing the same diet (HAGE, n = 10) or a one-month dietary AGE restriction (LAGE, n = 10). Blood and stool samples were collected at baseline and after intervention. Variable regions V3-V4 of 16s rDNA were sequenced and taxa was identified on the phyla, genus, and species levels. Dietary AGE restriction resulted in a significant decrease in serum Nε-(carboxymethyl) lysine (CML) and methylglyoxal-derivatives (MG). At baseline, our total cohort exhibited a lower relative abundance of Bacteroides and Alistipes genus and a higher abundance of Prevotella genus when compared to the published data of healthy population. Dietary AGE restriction altered the bacterial gut microbiota with a significant reduction in Prevotella copri and Bifidobacterium animalis relative abundance and increased Alistipes indistinctus, Clostridium citroniae, Clostridium hathewayi, and Ruminococcus gauvreauii relative abundance. We show in this pilot study significant microbiota differences in peritoneal dialysis patients' population, as well as the effects of dietary

  8. The receptor for advanced glycation end products is required for β‐catenin stabilization in a chemical‐induced asthma model

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    Yao, Lihong; Zhao, Haijin; Tang, Haixiong; Liang, Junjie; Liu, Laiyu; Dong, Hangming; Zou, Fei

    2016-01-01

    Background and Purpose Cytoplasmic retention of β‐catenin will lead to its nuclear translocation and subsequent interaction with the transcription factor TCF/LEF that regulates target gene expression. We have previously demonstrated aberrant expression of β‐catenin in a model of asthma induced by toluene diisocyanate (TDI). The aim of this study was to examine whether the receptor for advanced glycation end products (RAGE) can regulate β‐catenin expression in TDI‐induced asthma. Experimental Approach Male BALB/c mice were sensitized and challenged with TDI to generate a chemically‐induced asthma model. Inhibitors of RAGE, FPS‐ZM1 and the RAGE antagonist peptide (RAP), were injected i.p. after each challenge. Airway resistance was measured in vivo and bronchoalveolar lavage fluid was analysed. Lungs were examined by histology and immunohistochemistry. Western blotting and quantitative PCR were also used. Key Results Expression of RAGE and of its ligands HMGB1, S100A12, S100B, HSP70 was increased in TDI‐exposed lungs. These increases were inhibited by FPS‐ZM1 or RAP. Either antagonist blunted airway reactivity, airway inflammation and goblet cell metaplasia, and decreased release of Th2 cytokines. TDI exposure decreased level of membrane β‐catenin, phosphorylated Akt (Ser473), inactivated GSK3β (Ser9), dephosphorylated β‐catenin at Ser33/37/Thr41, which controls its cytoplasmic degradation, increased phosphorylated β‐catenin at Ser552, raised cytoplasmic and nuclear levels of β‐catenin and up‐regulated its targeted gene expression (MMP2, MMP7, MMP9, VEGF, cyclin D1, fibronectin), all of which were reversed by RAGE inhibition. Conclusion and Implications RAGE was required for stabilization of β‐catenin in TDI‐induced asthma, identifying protective effects of RAGE blockade in this model. PMID:27332707

  9. Maternal serum advanced glycation end products level as an early marker for predicting preterm labor/PPROM: a prospective preliminary study.

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    Kansu-Celik, Hatice; Tasci, Yasemin; Karakaya, Burcu Kisa; Cinar, Mehmet; Candar, Tuba; Caglar, Gamze Sinem

    2018-03-05

    To evaluate the value of maternal serum advanced glycation end products (AGEs) level at 11-13 weeks' gestation for the prediction of preterm labor and or preterm premature rupture of membranes (PPROM). This prospective cross-sectional study is performed in a university-affiliated hospital between February and April 2016. The participants of this study are low risk pregnant women. Blood samples for maternal AGEs level were collected in the first trimester of pregnancy and all women completed their antenatal follow-up and delivered in our center. During the follow-up 21 women developed preterm labor/PPROM. The first trimester maternal AGEs levels of preterm labor/PPROM cases were compared with uncomplicated cases (n = 25) matched for age-parity and BMI. The predictive value of AGEs levels for preterm labor/PPROM was also assessed. First-trimester AGEs levels were significantly higher in cases complicated with preterm labor/PPROM (1832 (415-6682) versus 1276 (466-6445) ng/L, p = 0.001 and 1722 (804-6682) versus 1343 (466-6445) ng/L, p = 0.025). According to receiver-operating characteristic curve analysis, the calculated cut off value of AGEs was 1538 ng/L with the sensitivity 91.7%, specificity 73.8%; and the negative and positive predictive values were 91.6 and 29.5%, respectively. For the prediction of preterm labor/PPROM, the relatively high AGEs levels in the first trimester might be an useful marker.

  10. A Soluble Receptor for Advanced Glycation End-Products Inhibits Hypoxia/Reoxygenation-Induced Apoptosis in Rat Cardiomyocytes via the Mitochondrial Pathway

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    Buxing Chen

    2012-09-01

    Full Text Available Severe myocardial dysfunction and tissue damage resulting from ischemia/reperfusion (I/R is a common clinical scenario in patients with certain types of heart diseases and therapies such as thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting, and cardiac transplantation. The underlining mechanism of endogenous cardiac protection after I/R injury has been a focus of current research. Growing evidences suggests that soluble receptor for advanced glycation end-products (sRAGE has a cardioprotective effect; however, its role in I/R injury remains unclear. We hypothesized that exogenous administration of sRAGE during hypoxia/reoxygenation (H/R induces cardioprotection by inhibiting cardiomyocyte apoptosis via multiple signals, involving mitochondrial membrane potential (MMP, the mitochondrial permeability transition pore (mPTP, mitochondrial cytochrome c, caspase-3, Bcl-2 and Bax. Neonatal rat cardiomyocytes underwent hypoxia for 3-h followed by 2-h reoxygenation or were treated with sRAGE for 10 min before H/R. Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05. In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2. Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

  11. Soluble receptor for advanced glycation end products in COPD: relationship with emphysema and chronic cor pulmonale: a case-control study.

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    Miniati, Massimo; Monti, Simonetta; Basta, Giuseppina; Cocci, Franca; Fornai, Edo; Bottai, Matteo

    2011-03-30

    The receptor for advanced glycation end products (RAGE) is a multiligand signal transduction receptor that can initiate and perpetuate inflammation. Its soluble isoform (sRAGE) acts as a decoy receptor for RAGE ligands, and is thought to afford protection against inflammation. With the present study, we aimed at determining whether circulating sRAGE is correlated with emphysema and chronic cor pulmonale in chronic obstructive pulmonary disease (COPD). In 200 COPD patients and 201 age- and sex-matched controls, we measured lung function by spirometry, and sRAGE by ELISA method. We also measured the plasma levels of two RAGE ligands, N-epsilon-carboxymethyl lysine and S100A12, by ELISA method. In the COPD patients, we assessed the prevalence and severity of emphysema by computed tomography (CT), and the prevalence of chronic cor pulmonale by echocardiography. Multiple quantile regression was used to assess the effects of emphysema, chronic cor pulmonale, smoking history, and comorbid conditions on the three quartiles of sRAGE. sRAGE was significantly lower (p = 0.007) in COPD patients (median 652 pg/mL, interquartile range 484 to 1076 pg/mL) than in controls (median 869 pg/mL, interquartile range 601 to 1240 pg/mL), and was correlated with the severity of emphysema (p cor pulmonale than in those without (p = 0.002). Such difference remained statistically significant after adjusting for smoking history, comorbidities, and emphysema severity. There was no significant difference in the plasma levels of the two RAGE ligands between cases and controls. sRAGE is significantly lower in patients with COPD than in age- and sex-matched individuals without airflow obstruction. Emphysema and chronic cor pulmonale are independent predictors of reduced sRAGE in COPD.

  12. Expression of advanced glycation end-products and NFκB in chick embryos exposed to dioxins and treated with acetylsalicylic acid and α-tocopherol.

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    Ostrowska, A; Gostomska-Pampuch, K; Lesków, A; Kuropka, P; Gamian, E; Ziólkowski, P; Kowalczyk, A; Lukaszewicz, E; Gamian, A; Calkosinski, I

    2017-06-01

    Dioxins have adverse and multifaceted effect on body functions. They are known to be carcinogens, immunotoxins, and teratogenic agents. In vivo, transformation of dioxins occurs after their interaction with the aryl hydrocarbon receptor (AhR) and leads to formation of proinflammatory and toxic metabolites. The aim of this study was to verify whether α-tocopherol (vitamin E) and acetylsalicylic acid (ASA), could reduce the damage caused by the action of dioxins. Fertile chicken eggs were injected with a solution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), followed by the injection of α-tocopherol or acetylsalicylic acid. Organs such as heart and liver were dissected from the chick embryos at d 13 and 19 of development and subjected to immunohistochemical analysis of presence of advanced glycation end products (AGEs) and nuclear factor kappa B (NFκB) in tissues. The AGEs were used as the marker for exposure to dioxins, since it is well established that their level increases in dioxin-damaged tissues. Formation of AGEs was evaluated in embryos exposed to dioxin and treated with vitamin E and/or ASA (against dioxin-exposed, untreated controls). We have found that TCDD causes developmental disorders and increases the level of AGEs in chick embryo tissues. The use of such pharmacological agents as vitamin E, ASA, and combination of ASA and vitamin E, inhibited formation of the AGEs in 13-day-old embryos and reduced the AGEs level in embryos after 19 d of the development. © 2017 Poultry Science Association Inc.

  13. Matrine-Type Alkaloids Inhibit Advanced Glycation End Products Induced Reactive Oxygen Species-Mediated Apoptosis of Aortic Endothelial Cells In Vivo and In Vitro by Targeting MKK3 and p38MAPK Signaling.

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    Liu, Zhongwei; Lv, Ying; Zhang, Yong; Liu, Fuqiang; Zhu, Ling; Pan, Shuo; Qiu, Chuan; Guo, Yan; Yang, Tielin; Wang, Junkui

    2017-12-02

    The matrine-type alkaloids are bioactive components extracted from Sophora flavescens , which is used in treatment of diabetes mellitus in traditional Chinese medicine. Advanced glycation end products mediate diabetic vascular complications. This study was aimed to investigate the protective effects and molecular mechanisms of matrine-type alkaloids on advanced glycation end products-induced reactive oxygen species-mediated endothelial apoptosis. Rats aorta and cultured rat aortic endothelial cells were exposed to advanced glycation end products. Matrine-type alkaloids, p38 mitogen-activated protein kinase (MAPK) inhibitor, and small interference RNAs against p38 MAPK kinases MAPK kinase kinase (MKK)3 and MKK6 were administrated. Intracellular reactive oxygen species production, cell apoptosis, phosphorylation of MKKs/p38 MAPK, and expression levels of heme oxygenase/NADPH quinone oxidoreductase were assessed. The nuclear factor erythroid 2-related factor 2 nuclear translocation and the binding activity of nuclear factor erythroid 2-related factor 2 with antioxidant response element were also evaluated. Matrine-type alkaloids suppressed intracellular reactive oxygen species production and inhibited endothelial cell apoptosis in vivo and in vitro by recovering phosphorylation of MKK3/6 and p38 MAPK, nuclear factor erythroid 2-related factor 2 nuclear translocation, and antioxidant response element binding activity, as well as the expression levels of heme oxygenase/NADPH quinone oxidoreductase. p38 MAPK inhibitor treatment impaired the effects of matrine-type alkaloids in vivo and in vitro. MKK3/6 silencing impaired the effects of matrine-type alkaloids in vitro. Matrine-type alkaloids exert endothelial protective effects against advanced glycation end products induced reactive oxygen species-mediated apoptosis by targeting MKK3/6 and enhancing their phosphorylation. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  14. Using Serum Advanced Glycation End Products-Peptides to Improve the Efficacy of World Health Organization Fasting Plasma Glucose Criterion in Screening for Diabetes in High-Risk Chinese Subjects.

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    Sun, Zilin; He, Jiajia; Qiu, Shanhu; Lei, Chenghao; Zhou, Yi; Xie, Zuolin; Zhang, Lin; Wang, Yanping; Jin, Hui

    2015-01-01

    The efficacy of using fasting plasma glucose (FPG) alone as a preferred screening test for diabetes has been questioned. This study was aimed to evaluate whether the use of serum advanced glycation end products-peptides (sAGEP) would help to improve the efficacy of FPG in diabetes screening among high-risk Chinese subjects with FPG World Health Organization FPG criterion (FPG ≥7.0 mmol/L). The area under ROC curves generated by the model on FPG-sAGEP was the largest compared with that on FPG-HbA1c, sAGEP, HbA1c or FPG in subjects with FPG <7.0 mmol/L. By maximizing the sum of sensitivity and specificity, the optimal critical line was determined as 0.69×FPG + 0.14×sAGEP = 7.03, giving a critical sensitivity of 91.2% in detecting 2h-PG ≥11.1 mmol/L, which was significantly higher than that of FPG-HbA1c or HbA1c. The model on FPG-sAGEP improves the efficacy of using FPG alone in detecting diabetes among high-risk Chinese subjects with FPG <7.0 mmol/L, and is worth being promoted for future diabetes screening.

  15. HMGB1 Contributes to the Expression of P-Glycoprotein in Mouse Epileptic Brain through Toll-Like Receptor 4 and Receptor for Advanced Glycation End Products.

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    Yan Chen

    Full Text Available The objective of the present study was to investigate the role of high-mobility group box-1 (HMGB1 in the seizure-induced P-glycoprotein (P-gp overexpression and the underlying mechanism. Kainic acid (KA-induced mouse seizure model was used for in vivo experiments. Male C57BL/6 mice were divided into four groups: normal saline control (NS group, KA-induced epileptic seizure (EP group, and EP group pretreated with HMGB1 (EP+HMGB1 group or BoxA (HMGB1 antagonist, EP+BoxA group. Compared to the NS group, increased levels of HMGB1 and P-gp in the brain were observed in the EP group. Injection of HMGB1 before the induction of KA further increased the expression of P-gp while pre-treatment with BoxA abolished this up-regulation. Next, the regulatory role of HMGB1 and its potential involved signal pathways were investigated in mouse microvascular endothelial bEnd.3 cells in vitro. Cells were treated with HMGB1, HMGB1 plus lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS [toll-like receptor 4 (TLR4 antagonist], HMGB1 plus FPS-ZM1 [receptor for advanced glycation end products (RAGE inhibitor], HMGB1 plus SN50 [nuclear factor-kappa B (NF-κB inhibitor], or vehicle. Treatment with HMGB1 increased the expression levels of P-gp, TLR4, RAGE and the activation of NF-κB in bEnd.3 cells. These effects were inhibited by the pre-treatment with either LPS-RS or FPS-ZM1, and were abolished by the pre-treatment of SN50 or a combination treatment of both LPS-RS and FPS-ZM1. Luciferase reporter assays showed that exogenous expression of NF-κB p65 increased the promoter activity of multidrug resistance 1a (P-gp-encoding gene in endothelial cells. These data indicate that HMGB1 contributes to the overexpression of P-gp in mouse epileptic brain tissues via activation of TLR4/RAGE receptors and the downstream transcription factor NF-κB in brain microvascular endothelial cells.

  16. Concentration of Endogenous Secretory Receptor for Advanced Glycation End Products and Matrix Gla Protein in Controlled and Uncontrolled Type 2 Diabetes Mellitus Patients

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    Dwi Yuniati Daulay

    2013-04-01

    Full Text Available BACKGROUND: Advanced glycation end products (AGE and their receptor (RAGE system play an important role in the development of diabetic vascular complications. Recently, an endogenous secretory RAGE (esRAGE has been identified as a novel splice variant, which lacks the transmembrane domain and is secreted in human sera. Interestingly, it was reported that esRAGE binds AGE ligands and neutralizes AGE actions. Many studies have reported that diabetes mellitus correlates with vascular calcification event and increases progressively in uncontrolled diabetes. Matrix Gla Protein (MGP is known to act as an inhibitor in vascular calcification. The aim of this study was to observe progress of vascular calcification in uncontrolled diabetes patient by biochemical markers MGP as inhibitor in vascular calcification, via mechanism of AGEs. METHODS: This study was an observational study with cross sectional design on adult type 2 diabetic male patients who were defined by the 2011 Indonesian diabetes mellitus consensus criteria. RESULTS: The results of this study showed that there was a positive significant correlation between esRAGE and HbA1C (r=0.651, p=0.009, and negative correlation between MGP and HbA1C (r=-0.465, p=0.081 in controlled diabetes group. In uncontrolled diabetes group there was a positive significant correlation between MGP and HbA1C (r=0.350, p=0.023, despite the fact esRAGE showed no significant correlation with HbA1C. There was no significant difference in level of esRAGE and MGP in controlled and uncontrolled diabetes group, but MGP showed lower level in uncontrolled diabetes group, contrary to esRAGE that had higher concentration. CONCLUSIONS: In diabetes condition, complications of vascular calcification are caused by the mechanism of increased AGE formation represented by esRAGE. In diabetes control it is very important to keep the blood vessels from complications caused by vascular calcification. KEYWORDS: type 2 diabetes mellitus

  17. Osteomeles schwerinae extracts inhibits the binding to receptors of advanced glycation end products and TGF-β1 expression in mesangial cells under diabetic conditions.

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    Kim, Young Sook; Jung, Dong Ho; Lee, Ik-Soo; Pyun, Bo-Jeong; Kim, Jin Sook

    2016-04-15

    Osteomeles schwerinae C. K. Schneid. (Rosaceae, OSSC) is a medicinal plant traditionally used to treat various diseases in Asia. The chemical constituents of OSSC have an inhibitory effect on aldose reductase activity, which has been implicated in the pathogenesis of diabetic complications. However, the protective effects of the pharmacological activity and potential mechanisms in diabetic nephropathy are still not known. In the present study, OSSC extracts and major compounds were examined for their effects on binding to the receptors of advanced glycation end products (RAGE) and on transforming growth factor-beta1 (TGF-β1) expression-related signal mechanisms in mouse glomerular mesangial cells (GMCs). A simple, rapid and efficient method was developed for the simultaneous determination of the marker compounds in the ethanol extract of the leaves and twigs of OSSC using HPLC-diode array detector (DAD). In this study, we determined the effects of OSSC extract and hyperoside on AGE and RAGE binding, and studied the mechanism of OSSC extract effects on AGE-bovine serum albumin (BSA)-treated GMCs. GMCs overexpressing human RAGE were cultured in AGE-BSA labeled with Alexa 488, and OSSC extract. AGE/RAGE binding were measured using fluorescence (excitation 485 nm/emission 528 nm). TGF-β1 protein expression levels were determined by western blot analyses. OSSC extracts of leaves and twigs inhibited on AGE/RAGE binding and TGF-β1 protein expression in a dose-dependent manner in GMCs. Furthermore, OSSC extracts reduced the effects on AGE-BSA-induced reactive oxidative species (ROS) formation and nuclear translocalization of transcription factor NF-κB. OSSC extracts inhibited phosphorylation of extracellular signal-regulated protein kinases1/2 (ERK1/2), p38 mitogen-activated protein kinases (p38MAPK), and IκB. Hyperoside also inhibited AGE/RAGE binding and ROS formation, and reduced TGF-β1 expression and IkB phosphorylation. OSSC extracts and hyperoside may attenuate

  18. Association Between Accumulation of Advanced Glycation End-Products and Hearing Impairment in Community-Dwelling Older People: A Cross-Sectional Sukagawa Study.

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    Niihata, Kakuya; Takahashi, Sei; Kurita, Noriaki; Yajima, Nobuyuki; Omae, Kenji; Fukuma, Shingo; Okano, Takayuki; Nomoto, Yukio; Omori, Koichi; Fukuhara, Shunichi

    2018-03-01

    The experimental studies suggested the hypothesis that the accumulation of advanced glycation end-products (AGEs) could induce hearing impairment. The purpose of this study is to examine the hypothesis among elderly people using an epidemiologic approach. Cross-sectional study. Sukagawa City, Fukushima, Japan. A total of 270 residents aged 75 years or over without dementia, who participated in a health check-up conducted in 2015. The exposure variable was AGEs, which was assessed using skin autofluorescence (AF) as a proxy measure. The primary outcome was moderate hearing impairment or worse, which was defined as a pure tone average of thresholds ≥41 decibel hearing level at 0.5, 1, 2, and 4 kHz in the better-hearing ear. The secondary outcome was the pure tone average of thresholds as a continuous variable. We estimated the odds ratio using a logistic regression model for the primary outcome and a general linear model for the mean difference in the pure tone average of thresholds for the secondary outcome. Both models were adjusted for relevant confounding factors: age, sex, smoking, diabetes, hypertension, and history of cerebrovascular diseases. The median (interquartile range) AF was 2.2 (2.0, 2.5) arbitrary units (AU). Moderate hearing impairment was reported in 88 participants (32.6%). For the primary outcome, we found significant associations between moderate hearing impairment and AF (adjusted odds ratio per 1 AU, 2.60; 95% confidence interval 1.26-5.35). For the secondary outcome, we also found a significant association between a 1-AU increase in AF and increased pure tone average, with a difference (6.52 dB per 1 AU; 95% confidence interval 2.18-10.86) comparable in magnitude to the increase in pure tone average observed for a 6-year increase in age in our population. Our study indicated that high levels of AGEs were independently associated with hearing impairment. Modifying levels of AGEs may prevent hearing impairment. Copyright © 2017 AMDA

  19. Receptor for advanced glycation end-products and World Trade Center particulate induced lung function loss: A case-cohort study and murine model of acute particulate exposure.

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    Caraher, Erin J; Kwon, Sophia; Haider, Syed H; Crowley, George; Lee, Audrey; Ebrahim, Minah; Zhang, Liqun; Chen, Lung-Chi; Gordon, Terry; Liu, Mengling; Prezant, David J; Schmidt, Ann Marie; Nolan, Anna

    2017-01-01

    World Trade Center-particulate matter(WTC-PM) exposure and metabolic-risk are associated with WTC-Lung Injury(WTC-LI). The receptor for advanced glycation end-products (RAGE) is most highly expressed in the lung, mediates metabolic risk, and single-nucleotide polymorphisms at the AGER-locus predict forced expiratory volume(FEV). Our objectives were to test the hypotheses that RAGE is a biomarker of WTC-LI in the FDNY-cohort and that loss of RAGE in a murine model would protect against acute PM-induced lung disease. We know from previous work that early intense exposure at the time of the WTC collapse was most predictive of WTC-LI therefore we utilized a murine model of intense acute PM-exposure to determine if loss of RAGE is protective and to identify signaling/cytokine intermediates. This study builds on a continuing effort to identify serum biomarkers that predict the development of WTC-LI. A case-cohort design was used to analyze a focused cohort of male never-smokers with normal pre-9/11 lung function. Odds of developing WTC-LI increased by 1.2, 1.8 and 1.0 in firefighters with soluble RAGE (sRAGE)≥97pg/mL, CRP≥2.4mg/L, and MMP-9≤397ng/mL, respectively, assessed in a multivariate logistic regression model (ROCAUC of 0.72). Wild type(WT) and RAGE-deficient(Ager-/-) mice were exposed to PM or PBS-control by oropharyngeal aspiration. Lung function, airway hyperreactivity, bronchoalveolar lavage, histology, transcription factors and plasma/BAL cytokines were quantified. WT-PM mice had decreased FEV and compliance, and increased airway resistance and methacholine reactivity after 24-hours. Decreased IFN-γ and increased LPA were observed in WT-PM mice; similar findings have been reported for firefighters who eventually develop WTC-LI. In the murine model, lack of RAGE was protective from loss of lung function and airway hyperreactivity and was associated with modulation of MAP kinases. We conclude that in a multivariate adjusted model increased sRAGE is

  20. Identifying advanced glycation end products as a major source of oxidants in aging: implications for the management and/or prevention of reduced renal function in elderly persons.

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    Vlassara, Helen; Uribarri, Jaime; Ferrucci, Luigi; Cai, Weijing; Torreggiani, Massimo; Post, James B; Zheng, Feng; Striker, Gary E

    2009-11-01

    Aging is characterized by increasing inflammation and oxidant stress (OS). Reduced renal function was present in more than 20% of normal-aged individuals sampled in the National Health and Nutrition Examination Survey (NHANES) cross-sectional study of the US population. Longitudinal studies in the United States and Italy showed that renal function does not decline in some individuals, suggesting that a search for causes of the loss of renal function in some persons might be indicated and interventions to reduce this outcome should be sought. Because advanced glycation end products (AGEs) induce both inflammation and OS, accumulate with age, and primarily are excreted by the kidney, one outcome of reduced renal function in aging could be decreased AGE disposal. The build-up of AGEs with reduced renal function could contribute to inflammation, increased oxidant stress, and accumulation of AGEs in aging. In fact, results from a longitudinal study of normal aging adults in Italy showed that the most significant correlation with mortality was the level of renal function. A clear link between inflammation, OS, AGEs, and chronic disease was shown in studies of mice that showed that reduction of AGE levels by drugs or decreased intake of AGEs reduces chronic kidney disease (CKD) and cardiovascular disease of aging. The data support a role for AGEs in the development of renal lesions in aging mice and reveal that AGEs in the diet are very important contributors to renal and cardiovascular lesions. AGEs signal through two receptors, one of which is anti-inflammatory (AGER1) and the other is proinflammatory (RAGE). Overexpression of AGER1 protects against OS and acute vascular injury. The reduction of AGEs in the diet is as efficient in preventing aging-related cardiovascular and renal lesions in mice as that seen with calorie restriction. Studies in normal adults of all ages and those with CKD suggest that the findings in mice may be directly applicable to both aging and CKD

  1. Receptor for advanced glycation end-products and World Trade Center particulate induced lung function loss: A case-cohort study and murine model of acute particulate exposure.

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    Erin J Caraher

    Full Text Available World Trade Center-particulate matter(WTC-PM exposure and metabolic-risk are associated with WTC-Lung Injury(WTC-LI. The receptor for advanced glycation end-products (RAGE is most highly expressed in the lung, mediates metabolic risk, and single-nucleotide polymorphisms at the AGER-locus predict forced expiratory volume(FEV. Our objectives were to test the hypotheses that RAGE is a biomarker of WTC-LI in the FDNY-cohort and that loss of RAGE in a murine model would protect against acute PM-induced lung disease. We know from previous work that early intense exposure at the time of the WTC collapse was most predictive of WTC-LI therefore we utilized a murine model of intense acute PM-exposure to determine if loss of RAGE is protective and to identify signaling/cytokine intermediates. This study builds on a continuing effort to identify serum biomarkers that predict the development of WTC-LI. A case-cohort design was used to analyze a focused cohort of male never-smokers with normal pre-9/11 lung function. Odds of developing WTC-LI increased by 1.2, 1.8 and 1.0 in firefighters with soluble RAGE (sRAGE≥97pg/mL, CRP≥2.4mg/L, and MMP-9≤397ng/mL, respectively, assessed in a multivariate logistic regression model (ROCAUC of 0.72. Wild type(WT and RAGE-deficient(Ager-/- mice were exposed to PM or PBS-control by oropharyngeal aspiration. Lung function, airway hyperreactivity, bronchoalveolar lavage, histology, transcription factors and plasma/BAL cytokines were quantified. WT-PM mice had decreased FEV and compliance, and increased airway resistance and methacholine reactivity after 24-hours. Decreased IFN-γ and increased LPA were observed in WT-PM mice; similar findings have been reported for firefighters who eventually develop WTC-LI. In the murine model, lack of RAGE was protective from loss of lung function and airway hyperreactivity and was associated with modulation of MAP kinases. We conclude that in a multivariate adjusted model increased s

  2. Genetics of Plasma Soluble Receptor for Advanced Glycation End-Products and Cardiovascular Outcomes in a Community-based Population: Results from the Atherosclerosis Risk in Communities Study.

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    Nisa M Maruthur

    Full Text Available Plasma soluble Receptor for Advanced Glycation End-products (sRAGE is a strong marker of vascular outcomes although evidence on the direction of association is mixed. Compared to whites, blacks have lower levels of sRAGE. We hypothesized that genetic determinants of sRAGE would help clarify the causal role of sRAGE and the black-white difference in sRAGE levels. We conducted a genome-wide analysis of sRAGE in whites and blacks from the Atherosclerosis Risk in Communities Study. Median plasma sRAGE levels were lower in blacks than whites (728 vs. 1067 pg/ml; P<0.0001. The T (vs. C allele of rs2070600, a missense variant in AGER, the gene encoding RAGE, was associated with approximately 50% lower sRAGE levels in both whites (N = 1,737; P = 7.26x10-16; minor allele frequency (MAF = 0.04 and blacks (N = 581; P = 0.02; MAF = 0.01. In blacks, the T (vs. C allele of rs2071288, intronic to AGER, was associated with 43% lower sRAGE levels (P = 2.22x10-8; MAF = 0.10 and was nearly absent in whites. These AGER SNPs explained 21.5% and 26% of the variation in sRAGE in blacks and whites, respectively, but did not explain the black-white difference in sRAGE. These SNPs were not significantly associated with incident death, coronary heart disease, diabetes, heart failure, or chronic kidney disease in whites (N = 8,130-9,017 or blacks (N = 2,293-2,871 (median follow up ~20 years. We identified strong genetic determinants of sRAGE that did not explain the large black-white difference in sRAGE levels or clearly influence risk of clinical outcomes, suggesting that sRAGE may not be a causal factor in development of these outcomes.

  3. Involvement of formyl peptide receptors in receptor for advanced glycation end products (RAGE - and amyloid beta 1-42-induced signal transduction in glial cells

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    Slowik Alexander

    2012-11-01

    Full Text Available Abstract Background Recent studies suggest that the chemotactic G-protein-coupled-receptor (GPCR formyl-peptide-receptor-like-1 (FPRL1 and the receptor-for-advanced-glycation-end-products (RAGE play an important role in the inflammatory response involved in neurodegenerative disorders such as Alzheimer’s disease (AD. Therefore, the expression and co-localisation of mouse formyl peptide receptor (mFPR 1 and 2 as well as RAGE in an APP/PS1 transgenic mouse model using immunofluorescence and real-time RT-PCR were analysed. The involvement of rat or human FPR1/FPRL1 (corresponds to mFPR1/2 and RAGE in amyloid-β 1–42 (Aβ1-42-induced signalling were investigated by extracellular signal regulated kinase 1/2 (ERK1/2 phosphorylation. Furthermore, the cAMP level in primary rat glial cells (microglia and astrocytes and transfected HEK 293 cells was measured. Formyl peptide receptors and RAGE were inhibited by a small synthetic antagonist WRW4 and an inactive receptor variant delta-RAGE, lacking the intracytoplasmatic domains. Results We demonstrated a strong increase of mFPR1/2 and RAGE expression in the cortex and hippocampus of APP/PS1 transgenic mice co-localised to the glial cells. In addition, the Aβ1-42-induced signal transduction is dependant on FPRL1, but also on FPR1. For the first time, we have shown a functional interaction between FPRL1/FPR1 and RAGE in RAGE ligands S100B- or AGE-mediated signalling by ERK1/2 phosphorylation and cAMP level measurement. In addition a possible physical interaction between FPRL1 as well as FPR1 and RAGE was shown with co-immunoprecipitation and fluorescence microscopy. Conclusions The results suggest that both formyl peptide receptors play an essential role in Aβ1-42-induced signal transduction in glial cells. The interaction with RAGE could explain the broad ligand spectrum of formyl peptide receptors and their important role for inflammation and the host defence against infections.

  4. Association of advanced glycation end products with A549 cells, a human pulmonary epithelial cell line, is mediated by a receptor distinct from the scavenger receptor family and RAGE.

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    Nakano, Nahoko; Fukuhara-Takaki, Kaori; Jono, Tadashi; Nakajou, Keisuke; Eto, Nobuaki; Horiuchi, Seikoh; Takeya, Motohiro; Nagai, Ryoji

    2006-05-01

    Cellular interactions with advanced glycation end products (AGE)-modified proteins are known to induce several biological responses, not only endocytic uptake and degradation, but also the induction of cytokines and growth factors, combined responses that may be linked to the development of diabetic vascular complications. In this study we demonstrate that A549 cells, a human pulmonary epithelial cell line, possess a specific binding site for AGE-modified bovine serum albumin (AGE-BSA) (K(d) = 27.8 nM), and additionally for EN-RAGE (extracellular newly identified RAGE binding protein) (K(d) = 118 nM). Western blot and RT-PCR analysis showed that RAGE (receptor for AGE) is highly expressed on A549 cells, while the expression of other known AGE-receptors such as galectin-3 and SR-A (class A scavenger receptor), are below the level of detection. The binding of (125)I-AGE-BSA to these cells is inhibited by unlabeled AGE-BSA, but not by EN-RAGE. In contrast, the binding of (125)I-EN-RAGE is significantly inhibited by unlabeled EN-RAGE and soluble RAGE, but not by AGE-BSA. Our results indicate that A549 cells possess at least two binding sites, one specific for EN-RAGE and the other specific for AGE-BSA. The latter receptor on A549 cells is distinct from the scavenger receptor family and RAGE.

  5. [Roles of advanced glycation end products and its receptor on the fetal brain injury in pregnant rats with gestational diabetes mellitus].

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    Luo, Shu-jing; Yang, Hui-xia

    2012-05-01

    To study the roles of advanced glycation end products and its receptor on fetal brain injury of gestational diabetes mellitus (GDM) rats. Twenty one adult pregnant Wistar rats were administered streptozotocin (STZ) intraperitoneally to induce GDM rats model. The fourteen pregnant rats were divided into two groups according to the fasting glucose on the 3(rd) day of pregnancy:severe GDM group with the fasting glucose > 16.7 mmol/L and mild GDM group with the fasting glucose between 6.7 - 16.7 mmol/L. Another seven pregnant rats were chosen as the severe GDM and intervention with micronutrient group, receiving gavage with micronutrient during the whole pregnancy. Five control rats received the same volume of citric acid buffer. All the pregnant rats were tested fasting glucose from the tail vein and their weight on the pregnant day 3, 13 and 19. Maternal serum levels of AGE were measured by ELISA and RAGE levels in the embryonic brain tissues were tested by immunohistochemistry. (1) There was no statistically significant difference of pre-pregnancy fasting glucose level among all groups (P > 0.05). The fasting glucose levels on the 3(rd) day and the mean fasting glucouse level of pregnancy in the severe GDM group and the severe GDM and intervention with micronutrient group were higher than those of the control group (P 0.05). (2) The serum AGE levels in the severe GDM group and the mild GDM group were (1037 ± 38) ng/L and (880 ± 34) ng/L respectively, with no significant difference (P > 0.05). The serum AGE levels in the control group and the severe GDM and intervention with micronutrient group were (857 ± 32) ng/L and (988 ± 37) ng/L, and the difference was statistically significant (P 0.05). (3) The serum AGE levels in the severe GDM group, mild GDM group and the control group were positively associated with the mean glucose level of pregnancy (r = 0.603, P nerve cell number and morphology in the control group were normal. While in the mild GDM group fetal

  6. Systemic levels of the anti-inflammatory decoy receptor soluble RAGE (receptor for advanced glycation end products) are decreased in dogs with inflammatory bowel disease.

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    Heilmann, Romy M; Otoni, Cristiane C; Jergens, Albert E; Grützner, Niels; Suchodolski, Jan S; Steiner, Jörg M

    2014-10-15

    Inflammatory bowel disease (IBD) is a common condition in dogs, and a dysregulated innate immunity is believed to play a major role in its pathogenesis. S100A12 is an endogenous damage-associated molecular pattern molecule, which is involved in phagocyte activation and is increased in serum/fecal samples from dogs with IBD. S100A12 binds to the receptor of advanced glycation end products (RAGE), a pattern-recognition receptor, and results of studies in human patients with IBD and other conditions suggest a role of RAGE in chronic inflammation. Soluble RAGE (sRAGE), a decoy receptor for inflammatory proteins (e.g., S100A12) that appears to function as an anti-inflammatory molecule, was shown to be decreased in human IBD patients. This study aimed to evaluate serum sRAGE and serum/fecal S100A12 concentrations in dogs with IBD. Serum and fecal samples were collected from 20 dogs with IBD before and after initiation of medical treatment and from 15 healthy control dogs. Serum sRAGE and serum and fecal S100A12 concentrations were measured by ELISA, and were compared between dogs with IBD and healthy controls, and between dogs with a positive outcome (i.e., clinical remission, n=13) and those that were euthanized (n=6). The relationship of serum sRAGE concentrations with clinical disease activity (using the CIBDAI scoring system), serum and fecal S100A12 concentrations, and histologic disease severity (using a 4-point semi-quantitative grading system) was tested. Serum sRAGE concentrations were significantly lower in dogs with IBD than in healthy controls (p=0.0003), but were not correlated with the severity of histologic lesions (p=0.4241), the CIBDAI score before (p=0.0967) or after treatment (p=0.1067), the serum S100A12 concentration before (p=0.9214) and after treatment (p=0.4411), or with the individual outcome (p=0.4066). Clinical remission and the change in serum sRAGE concentration after treatment were not significantly associated (p=0.5727); however, serum s

  7. Using Serum Advanced Glycation End Products-Peptides to Improve the Efficacy of World Health Organization Fasting Plasma Glucose Criterion in Screening for Diabetes in High-Risk Chinese Subjects.

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    Zilin Sun

    Full Text Available The efficacy of using fasting plasma glucose (FPG alone as a preferred screening test for diabetes has been questioned. This study was aimed to evaluate whether the use of serum advanced glycation end products-peptides (sAGEP would help to improve the efficacy of FPG in diabetes screening among high-risk Chinese subjects with FPG <7.0 mmol/L. FPG, 2-h plasma glucose (2h-PG, serum glycated haemoglobin A1c (HbA1c, and sAGEP were measured in 857 Chinese subjects with risk factors for diabetes. The areas under receiver operating characteristic (ROC curves generated by logistic regression models were assessed and compared to find the best model for diabetes screening in subjects with FPG <7.0 mmol/L. The optimal critical line was determined by maximizing the sum of sensitivity and specificity. Among the enrolled subjects, 730 of them had FPG <7.0 mmol/L, and only 41.7% new diabetes cases were identified using the 1999 World Health Organization FPG criterion (FPG ≥7.0 mmol/L. The area under ROC curves generated by the model on FPG-sAGEP was the largest compared with that on FPG-HbA1c, sAGEP, HbA1c or FPG in subjects with FPG <7.0 mmol/L. By maximizing the sum of sensitivity and specificity, the optimal critical line was determined as 0.69×FPG + 0.14×sAGEP = 7.03, giving a critical sensitivity of 91.2% in detecting 2h-PG ≥11.1 mmol/L, which was significantly higher than that of FPG-HbA1c or HbA1c. The model on FPG-sAGEP improves the efficacy of using FPG alone in detecting diabetes among high-risk Chinese subjects with FPG <7.0 mmol/L, and is worth being promoted for future diabetes screening.

  8. Advanced Glycation End Products Affect Osteoblast Proliferation and Function by Modulating Autophagy Via the Receptor of Advanced Glycation End Products/Raf Protein/Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase Kinase/Extracellular Signal-regulated Kinase (RAGE/Raf/MEK/ERK) Pathway.

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    Meng, Hong-Zheng; Zhang, Wei-Lin; Liu, Fei; Yang, Mao-Wei

    2015-11-20

    The interaction between advanced glycation end products (AGEs) and receptor of AGEs (RAGE) is associated with the development and progression of diabetes-associated osteoporosis, but the mechanisms involved are still poorly understood. In this study, we found that AGE-modified bovine serum albumin (AGE-BSA) induced a biphasic effect on the viability of hFOB1.19 cells; cell proliferation was stimulated after exposure to low dose AGE-BSA, but cell apoptosis was stimulated after exposure to high dose AGE-BSA. The low dose AGE-BSA facilitates proliferation of hFOB1.19 cells by concomitantly promoting autophagy, RAGE production, and the Raf/MEK/ERK signaling pathway activation. Furthermore, we investigated the effects of AGE-BSA on the function of hFOB1.19 cells. Interestingly, the results suggest that the short term effects of low dose AGE-BSA increase osteogenic function and decrease osteoclastogenic function, which are likely mediated by autophagy and the RAGE/Raf/MEK/ERK signal pathway. In contrast, with increased treatment time, the opposite effects were observed. Collectively, AGE-BSA had a biphasic effect on the viability of hFOB1.19 cells in vitro, which was determined by the concentration of AGE-BSA and treatment time. A low concentration of AGE-BSA activated the Raf/MEK/ERK signal pathway through the interaction with RAGE, induced autophagy, and regulated the proliferation and function of hFOB1.19 cells. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. bFGF and TGFβ1 growth factors, inflammatory markers (IL-6, TNF-α, CRP and advanced glycation end-products (AGE, RAGE in patients with ischemic heart disease and type 2 diabetes mellitus

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    Ekaterina Vladimirovna Ivannikova

    2013-11-01

    Full Text Available Aims. To evaluate plasma levels of transforming growth factor beta (TGFβ1, basic fibroblast growth factor (bFGF, markers for nonspecific inflammatory process (interleukin-6 (IL-6, tumor necrosis factor alpha (TNF-α, C-reactive protein (CRP and their putative correlation with advanced glycation end-products relative to diabetes compensation in patients with ischemic heart disease (IHD.Materials and Methods. 87 patients with IHD were enrolled in this study. All subjects underwent standard clinical examination, including laboratory assessment of glycemic parameters, lipid panel and renal function, with echocardiography, supplemented with coronary angiography. Analyses for study parameters were performed on samples obtained from aorta and, separately, from cubital vein during coronary angiography.Results. Diabetes mellitus in patients with IHD is firmly associated with TGFβ1, IL-6 and CRP elevation in both arterial and venous plasma. TGFβ1 positively correlates with lipid profile parameters. Plasma concentration of inflammatory markers and advanced glycation end-products positively correlates with the extent of coronary lesions in relation to the presence of diabetes mellitus.Conclusion. Our data suggests the interplay between connective tissue growth factors and lipid metabolism in the atherosclerotic process.

  10. Produtos da glicação avançada dietéticos e as complicações crônicas do diabetes Dietetics advanced glycation end-products and chronic complications of diabetes

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    Júnia Helena Porto Barbosa

    2009-02-01

    a conduta terapêutica, concorrendo para a melhoria da qualidade de vida dos portadores dessa enfermidade.The generation of advanced glycation end products is one of the principal mechanisms that lead to the pathologies associated with diabetes mellitus, which include cardiopathy, retinopathy, neuropathy and nephropathy. The objective of this revision is to analyse the role of the advanced glycation end products present in food as intermediaries of diabetic complications, presenting strategies to reduce their ingestion. For this purpose, research was carried out in databases of publications of the area, for the last 15 years, taking into account revision, experimental and clinical studies. Advanced glycation end products are a heterogenous group of molecules coming from non-enzymatic reactions between amino and carbonyl groups, examples being carboxymethyllisine and pentosidine found in food and in vivo. The advanced glycation end products ingested are absorbed and, along with endogenous advanced glycation end-products, promote the progression of the complications of diabetes. There is a direct correlation between advanced glycation end products consumption and blood concentration. Their restriction in food results in the suppression of serum levels of the markers of vascular disease and the intermediaries of inflammation directly involved in the development of diabetic degenerations. The current dietary orientations are concentrated on the proportion of nutrients and on energetic restriction. The risk of ingestion of advanced glycation end products formed during the processing of food should be taken in consideration. It is simply recommended that in the preparation of food, the use of low temperatures for short periods, in the presence of water, has important effects in the prevention of the complications of diabetes. The study of the mechanisms involved in the generation of advanced glycation end products and the antiglycation properties of compounds presented in

  11. Inhibition of Advanced Glycation End-Product Formation by Origanum majorana L. In Vitro and in Streptozotocin-Induced Diabetic Rats

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    Rosa Martha Perez Gutierrez

    2012-01-01

    Full Text Available The development of AGE inhibitors is considered to have therapeutic potential in patients with diabetes diseases. The aim of the present study was investigate the effect of methanolic extract of the leaves of Origanum majorana (OM used as spice in many countries on AGEs formation. In vitro studies indicated a significant inhibitory effects on the formation of AGEs. Their antiglycation activities were not only brought about by their antioxidant activities but also related to their trapping abilities of reactive carbonyl species such as methylglyoxal, an intermediate reactive carbonyl of AGE formation. The results demonstrate that OM have significant effects on in vitro AGE formation, and the glycation inhibitory activity was more effectively than those obtained using as standard antiglycation agent aminoguanidine. OM is a potent agent for protecting LDL against oxidation and glycation. Treatment of streptozotocin-diabetic mice with OM and glibenclamide for 28 days had beneficial effects on renal metabolic abnormalities including glucose level and AGEs formation. Diabetic mice showed increase in tail tendon collagen, glycated collagen linked fluorescence and reduction in pepsin digestion. Treatment with OM improved these parameters when compared to diabetic control and glibenclamide.

  12. Expression of advanced glycation end-products on sun-exposed and non-exposed cutaneous sites during the ageing process in humans.

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    Maria Crisan

    Full Text Available The glycation process is involved in both the intrinsic (individual, genetic and extrinsic (ultraviolet light, polution and lifestyle aging processes, and can be quantified at the epidermal or dermal level by histological, immunohistochemical (IHC, or imagistic methods. Our study is focused on a histological and immunohistological comparison of sun-protected regions versus sun-exposed regions from different age groups of skin phototype III subjects, related to the aging process. Skin samples collected from non-protected and UV protected regions of four experimental groups with different ages, were studied using histology and IHC methods for AGE-CML [N(epsilon-(carboxymethyllysine]. A semi-quantitative assessment of the CML expression in the microvascular endothelium and dermal fibroblasts was performed. The Pearson one-way ANOVA was used to compare data between the groups. In the dermis of sun-exposed skin, the number and the intensity of CML positive cells in both fibroblasts and endothelial cells (p<0.05 was higher compared to sun-protected skin, and was significantly increased in older patients. The sun-exposed areas had a more than 10% higher AGE-CML score than the protected areas. No statistically significant correlation was observed between the histological score and the IHC expression of CML. We concluded that in healthy integument, the accumulation of final glycation products increases with age and is amplified by ultraviolet exposure. The study provides new knowledge on differences of AGE-CML between age groups and protected and unprotected areas and emphasizes that endothelium and perivascular area are most affected, justifying combined topical and systemic therapies.

  13. Expression of advanced glycation end-products on sun-exposed and non-exposed cutaneous sites during the ageing process in humans.

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    Crisan, Maria; Taulescu, Marian; Crisan, Diana; Cosgarea, Rodica; Parvu, Alina; Cãtoi, Cornel; Drugan, Tudor

    2013-01-01

    The glycation process is involved in both the intrinsic (individual, genetic) and extrinsic (ultraviolet light, polution and lifestyle) aging processes, and can be quantified at the epidermal or dermal level by histological, immunohistochemical (IHC), or imagistic methods. Our study is focused on a histological and immunohistological comparison of sun-protected regions versus sun-exposed regions from different age groups of skin phototype III subjects, related to the aging process. Skin samples collected from non-protected and UV protected regions of four experimental groups with different ages, were studied using histology and IHC methods for AGE-CML [N(epsilon)-(carboxymethyl)lysine]. A semi-quantitative assessment of the CML expression in the microvascular endothelium and dermal fibroblasts was performed. The Pearson one-way ANOVA was used to compare data between the groups. In the dermis of sun-exposed skin, the number and the intensity of CML positive cells in both fibroblasts and endothelial cells (p<0.05) was higher compared to sun-protected skin, and was significantly increased in older patients. The sun-exposed areas had a more than 10% higher AGE-CML score than the protected areas. No statistically significant correlation was observed between the histological score and the IHC expression of CML. We concluded that in healthy integument, the accumulation of final glycation products increases with age and is amplified by ultraviolet exposure. The study provides new knowledge on differences of AGE-CML between age groups and protected and unprotected areas and emphasizes that endothelium and perivascular area are most affected, justifying combined topical and systemic therapies.

  14. The anti-inflammation effect of Moutan Cortex on advanced glycation end products-induced rat mesangial cells dysfunction and High-glucose-fat diet and streptozotocin-induced diabetic nephropathy rats.

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    Zhang, Ming-hua; Feng, Liang; Zhu, Mao-mao; Gu, Jun-fei; Jiang, Jun; Cheng, Xu-dong; Ding, Shu-ming; Wu, Chan; Jia, Xiao-bin

    2014-01-01

    Moutan Cortex (MC, family: Paeonia suffruticosa Andr.) is a well-known traditional herbal medicine that has been shown to hold a protective effect on inflammation in several diseases. However, its anti-inflammatory activity on diabetic nephropathy (DN) has been less reported. The present study was conducted to evaluate the potential attenuation activities of MC on inflammation in AGEs-induced rat mesangial cells dysfunction and high-glucose-fat diet and streptozotocin (STZ)-induced DN rats and explore the possible mechanism underlying its DN effect. The inflammation in mesangial cells (HBZY-1) was induced by 200 μg/ml advanced glycation end products (AGEs). DN rats model was established by an administration high-glucose-fat diet and an intraperitoneal injection of STZ (30 mg/kg). Interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) level in cell supernatant and rats serum were detected by appropriate kits. A co-culture system of mesangial cells and macrophages was performed to evaluate the migration of macrophages. Immunohistochemical assay was applied to examine transforming growth factor beta1 (TGF-β1), IL-6, MCP-1 and intercellular adhesion molecule-1 (ICAM-1) expression in kidney tissues of rats. Furthermore, western blot analysis was carried out to examine TGF-β1, IL-6, MCP-1, ICAM-1 and RAGE protein expressions in mesangial cells. Pretreatment with MC could significantly inhibit AGEs-induced migration of macrophages in the co-culture system of mesangial cell and macrophage. MC could decrease IL-6 and MCP-1 levels in serum of DN rats in a dose-dependent manner. Furthermore, MC also improved the blood glucose, serum creatinine and urine protein levels. Both immunocytochemistry analysis and western blot analysis showed that MC decreased significantly the over-expression of IL-6, MCP-1, TGF-β1, ICAM-1 and RAGE in mesangial cells or kidney tissues. Additionally, the protein expression of proinflammatory cytokine could also be down-regulated by

  15. The receptor for advanced glycation end products (RAGE) is a cellular binding site for amphoterin. Mediation of neurite outgrowth and co-expression of rage and amphoterin in the developing nervous system.

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    Hori, O; Brett, J; Slattery, T; Cao, R; Zhang, J; Chen, J X; Nagashima, M; Lundh, E R; Vijay, S; Nitecki, D

    1995-10-27

    The receptor for advanced glycation end products (RAGE), a newly-identified member of the immunoglobulin superfamily, mediates interactions of advanced glycation end product (AGE)-modified proteins with endothelium and other cell types. Survey of normal tissues demonstrated RAGE expression in situations in which accumulation of AGEs would be unexpected, leading to the hypothesis that under physiologic circumstances, RAGE might mediate interaction with ligands distinct from AGEs. Sequential chromatography of bovine lung extract identified polypeptides with M(r) values of approximately 12,000 (p12) and approximately 23,000 (p23) which bound RAGE. NH2-terminal and internal protein sequence data for p23 matched that reported previously for amphoterin. Amphoterin purified from rat brain or recombinant rat amphoterin bound to purified sRAGE in a saturable and dose-dependent manner, blocked by anti-RAGE IgG or a soluble form of RAGE (sRAGE). Cultured embryonic rat neurons, which express RAGE, displayed dose-dependent binding of 125I-amphoterin which was prevented by blockade of RAGE using antibody to the receptor or excess soluble receptor (sRAGE). A functional correlate of RAGE-amphoterin interaction was inhibition by anti-RAGE F(ab')2 and sRAGE of neurite formation by cortical neurons specifically on amphoterin-coated substrates. Consistent with a potential role for RAGE-amphoterin interaction in development, amphoterin and RAGE mRNA/antigen were co-localized in developing rat brain. These data indicate that RAGE has physiologically relevant ligands distinct from AGEs which are likely, via their interaction with the receptor, to participate in physiologic processes outside of the context of diabetes and accumulation of AGEs.

  16. The effect of fibroblast growth factors and advanced glycation end-products on the intima-media complex thickness in patients with coronary heart disease and type 2 diabetes

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    Ekaterina Vladimirovna Ivannikova

    2014-05-01

    Full Text Available ObjectiveTo determine the levels of fibroblast transforming growth factor (TGFβ1, basic fibroblast growth factor (β-FGF, markers of nonspecific inflammatory response (interleukin-6 (IL-6, C-reactive protein (CRP, advanced glycation end-products (AGEs and their receptors (RAGEs and to study their effect on the intima-media complex (IMC thickness in patients with coronary heart disease (CHD and type 2 diabetes, depending on carbohydrate metabolism compensation.Materials and Methods37 patients with CHD underwent a general clinical examination, analysis of the carbohydrate and lipid metabolism parameters and the renal function, and also were evaluated with instrumental methods of analysis (echocardiography, coronary angiography and duplex scanning of the brachiocephalic arteries. To determine the level of the analyzed parameters, blood samples were taken from the aorta during coronary angiography and concomitantly from the cubital vein in all patients.ResultsThe presence of diabetes mellitus (DM in patients with CHD was found to be associated with a more severe atherosclerotic disease of the coronary and brachiocephalic vessels. A direct correlation between the degree of stenosis and the level of fibroblast growth factors, inflammatory factors, and advanced glycation end-products was found. A direct correlation between AGE and TGFβ1 and the lipid metabolism parameters was established. A statistically significant elevation of the studied parameters in the arterial and venous blood of patients with DM was revealed.ConclusionThese findings confirm the relationship between connective tissue disorders and lipid metabolism in the pathogenesis of atherosclerosis. A negative effect of hyperglycaemia on atherosclerotic changes of the vascular wall was demonstrated.

  17. The Receptor for Advanced Glycation End-Products (RAGE) Is Only Present in Mammals, and Belongs to a Family of Cell Adhesion Molecules (CAMs)

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    Sessa, Luca; Gatti, Elena; Zeni, Filippo; Antonelli, Antonella; Catucci, Alessandro; Koch, Michael; Pompilio, Giulio; Fritz, Günter

    2014-01-01

    The human receptor for advanced glycation endproducts (RAGE) is a multiligand cell surface protein belonging to the immunoglobulin superfamily, and is involved in inflammatory and immune responses. Most importantly, RAGE is considered a receptor for HMGB1 and several S100 proteins, which are Damage-Associated Molecular Pattern molecules (DAMPs) released during tissue damage. In this study we show that the Ager gene coding for RAGE first appeared in mammals, and is closely related to other genes coding for cell adhesion molecules (CAMs) such as ALCAM, BCAM and MCAM that appeared earlier during metazoan evolution. RAGE is expressed at very low levels in most cells, but when expressed at high levels, it mediates cell adhesion to extracellular matrix components and to other cells through homophilic interactions. Our results suggest that RAGE evolved from a family of CAMs, and might still act as an adhesion molecule, in particular in the lung where it is highly expressed or under pathological conditions characterized by an increase of its protein levels. PMID:24475194

  18. Diverging effects of diabetes mellitus in patients with peripheral artery disease and abdominal aortic aneurysm and the role of advanced glycation end-products: ARTERY study - protocol for a multicentre cross-sectional study.

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    de Vos, L C; Boersema, J; Hillebrands, J L; Schalkwijk, C G; Meerwaldt, R; Breek, J C; Smit, A J; Zeebregts, C J; Lefrandt, J D

    2017-04-11

    Diabetes mellitus is a well-defined risk factor for peripheral artery disease (PAD), but protects against the development and growth of abdominal aortic aneurysm (AAA). Diabetes mellitus is associated with arterial stiffening and peripheral arterial media sclerosis. Advanced glycation end-products (AGEs) are increased in diabetes mellitus and cardiovascular disease. AGEs are known to form cross-links between proteins and are associated with arterial stiffness. Whether AGEs contribute to the protective effects of diabetes mellitus in AAA is unknown. Therefore, the ARTERY ( A dvanced glycation end-p R oducts in patients with peripheral ar T ery dis E ase and abdominal ao R tic aneur Y sm) study is designed to evaluate the role of AGEs in the diverging effects of diabetes mellitus on AAA and PAD. This cross-sectional multicentre study will compare the amount, type and location of AGEs in the arterial wall in a total of 120 patients with AAA or PAD with and without diabetes mellitus (n=30 per subgroup). Also, local and systemic vascular parameters, including pulse wave velocity, will be measured to evaluate the association between arterial stiffness and AGEs. Finally, AGEs will be measured in serum, urine, and assessed in skin with skin autofluorescence using the AGE Reader. This study is approved by the Medical Ethics committees of University Medical Center Groningen, Martini Hospital and Medisch Spectrum Twente, the Netherlands. Study results will be disseminated through peer-reviewed journals and scientific events. trialregister.nl NTR 5363. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. The Distinct and Cooperative Roles of Toll-Like Receptor 9 and Receptor for Advanced Glycation End Products in Modulating In Vivo Inflammatory Responses to Select CpG and Non-CpG Oligonucleotides.

    Science.gov (United States)

    Paz, Suzanne; Hsiao, Jill; Cauntay, Patrick; Soriano, Armand; Bai, Lawrence; Machemer, Todd; Xiao, Xiaokun; Guo, Shuling; Hung, Gene; Younis, Husam; Bennett, C Frank; Henry, Scott; Yun, Theodore J; Burel, Sébastien

    2017-10-01

    Antisense oligonucleotides (ASOs) are widely accepted therapeutic agents that suppress RNA transcription. While the majority of ASOs are well tolerated in vivo, few sequences trigger inflammatory responses in absence of conventional CpG motifs. In this study, we identified non-CpG oligodeoxy-nucleotide (ODN) capable of triggering an inflammatory response resulting in B cell and macrophage activation in a MyD88- and TLR9-dependent manner. In addition, we found the receptor for advance glycation end product (RAGE) receptor to be involved in the initiation of inflammatory response to suboptimal concentrations of both CpG- and non-CpG-containing ODNs. In contrast, dosing RAGE KO mice with high doses of CpG or non-CpG ODNs lead to a stronger inflammatory response than observed in wild-type mice. Together, our data provide a previously uncharacterized in vivo mechanism contingent on ODN-administered dose, where TLR9 governs the primary response and RAGE plays a distinct and cooperative function in providing a pivotal role in balancing the immune response.

  20. Nifedipine, a calcium channel blocker, inhibits advanced glycation end product (AGE)-elicited mesangial cell damage by suppressing AGE receptor (RAGE) expression via peroxisome proliferator-activated receptor-gamma activation

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Takanori [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011 (Japan); Yamagishi, Sho-ichi, E-mail: shoichi@med.kurume-u.ac.jp [Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011 (Japan); Takeuchi, Masayoshi [Department of Pathophysiological Science, Faculty of Pharmaceutical Science, Hokuriku University, Kanazawa (Japan); Ueda, Seiji; Fukami, Kei; Okuda, Seiya [Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

    2009-07-24

    The interaction between advanced glycation end products (AGE) and their receptor RAGE mediates the progressive alteration in renal architecture and loss of renal function in diabetic nephropathy. Oxidative stress generation and inflammation also play a central role in diabetic nephropathy. This study investigated whether and how nifedipine, a calcium channel blocker (CCB), blocked the AGE-elicited mesangial cell damage in vitro. Nifedipine, but not amlodipine, a control CCB, down-regulated RAGE mRNA levels and subsequently reduced reactive oxygen species (ROS) generation in AGE-exposed mesangial cells. AGE increased mRNA levels of vascular cell adhesion molecule-1 (VCAM-1) and induced monocyte chemoattractant protein-1 (MCP-1) production in mesangial cells, both of which were prevented by the treatment with nifedipine, but not amlodipine. The beneficial effects of nifedipine on AGE-exposed mesangial cells were blocked by the simultaneous treatment of GW9662, an inhibitor of peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}). Although nifedipine did not affect expression levels of PPAR-{gamma}, it increased the PPAR-{gamma} transcriptional activity in mesangial cells. Our present study provides a unique beneficial aspect of nifedipine on diabetic nephropathy; it could work as an anti-inflammatory agent against AGE by suppressing RAGE expression in cultured mesangial cells via PPAR-{gamma} activation.

  1. Association between Asymmetric Dimethylarginine and Pentosidine in Dialysis Effluent of Peritoneal Dialysis Patients -A possible intraperitoneal crosstalk between asymmetric dimethylarginine and advanced glycation end products in peritoneal dialysis patients.

    Science.gov (United States)

    Ishida, Mari; Kakuta, Takatoshi; Miyakogawa, Takayo; Tatsumi, Ryoko; Matsumoto, Chiemi; Fukagawa, Masafumi

    2016-06-20

    Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase. Elevated serum ADMA concentration is associated with impaired vascular endothelial function. We examined the relationships of ADMA with pentosidine, a representative advanced glycation end product, cytokines and the markers of peritoneal inflammation, damage and repair in dialysate effluent of peritoneal dialysis patients. Study design was cross-sectional. Twenty-eight peritoneal dialysis patients who were ≥ 18 years of age, had been on peritoneal dialysis for at least 3 months and had no history of renal transplantation were enrolled. Dialysis effluent and blood were sampled after 8 hours of peritoneal dialysis. Concentrations of ADMA, pentosidine, cytokines and the markers of peritoneal inflammation, damage and repair were determined in dialysis effluent. Blood samples were analyzed for routine laboratory parameters. The effluent ADMA level had a significant correlation with effluent pentosidine concentration (R=0.511, P=0.005), but not with interleukin-6, interleukin-8, transforming growth factor-α, hyaluronic acid, cancer antigen 125 or fibrinogen/fibrin degradation products. In the light of available evidence, our results suggest that AGEs generated during dialysate dwelling alters ADMA metabolism in the peritoneal tissues, leading to ADMA accumulation in the peritoneal cavity.

  2. A soluble receptor for advanced glycation end-products inhibits myocardial apoptosis induced by ischemia/reperfusion via the JAK2/STAT3 pathway.

    Science.gov (United States)

    Jiang, Xue; Guo, Cai-xia; Zeng, Xiang-jun; Li, Hui-hua; Chen, Bu-xing; Du, Feng-he

    2015-08-01

    sRAGE can protect cardiomyocytes from apoptosis induced by ischemia/reperfusion (I/R). However, the signaling mechanisms in cardioprotection by sRAGE are currently unknown. We investigated the cardioprotective effect and potential molecular mechanisms of sRAGE inhibition on apoptosis in the mouse myocardial I/R as an in vivo model and neonatal rat cardiomyocyte subjected to ischemic buffer as an in vitro model. Cardiac function and myocardial infarct size following by I/R were evaluated with echocardiography and Evans blue/2,3,5-triphenyltetrazolium chloride. Apoptosis was detected by TUNEL staining and caspase-3 activity. Expression of the apoptosis-related proteins p53, Bax, Bcl-2, JAK2/p-JAK2, STAT3/p-STAT3, AKT/p-AKT, ERK/p-ERK, STAT5A/p-STAT5A and STAT6/p-STAT6 were detected by western blot analysis in the presence and absence of the JAK2 inhibitor AG 490. sRAGE (100 µg/day) improved the heart function in mice with I/R: the left ventricular ejection fraction and fractional shortening were increased by 42 and 57%, respectively; the infarct size was decreased by 52%, the TUNEL-positive myocytes by 66%, and activity of caspase-3 by 24%, the protein expression of p53 and ratio of Bax to Bcl-2 by 29 and 88%, respectively; protein expression of the p-JAK2, p-STAT3 and p-AKT were increased by 92, 280 and 31%, respectively. sRAGE have no effect on protein expression of p-ERK1/2, p-STAT5A and p-STAT6 following by I/R. sRAGE (900 nmol/L) exhibited anti-apoptotic effects in cardiomyocytes by decreasing TUNEL-positive myocytes by 67% and caspase-3 activity by 20%, p53 protein level and the Bax/Bcl-2 ratio by 58 and 86%, respectively; increasing protein expression of the p-JAK2 and p-STAT3 by 26 and 156%, respectively, p-AKT protein level by 33%. The anti-apoptotic effects of sRAGE following I/R were blocked by JAK2 inhibitor AG 490. The effect of sRAGE reduction on TUNEL-positive myocytes and caspase-3 activity were abolished by PI3K inhibitor LY294002, but not ERK 1

  3. DNAX-activating Protein 10 (DAP10) Membrane Adaptor Associates with Receptor for Advanced Glycation End Products (RAGE) and Modulates the RAGE-triggered Signaling Pathway in Human Keratinocytes*

    Science.gov (United States)

    Sakaguchi, Masakiyo; Murata, Hitoshi; Aoyama, Yumi; Hibino, Toshihiko; Putranto, Endy Widya; Ruma, I. Made Winarsa; Inoue, Yusuke; Sakaguchi, Yoshihiko; Yamamoto, Ken-ichi; Kinoshita, Rie; Futami, Junichiro; Kataoka, Ken; Iwatsuki, Keiji; Huh, Nam-ho

    2014-01-01

    The receptor for advanced glycation end products (RAGE) is involved in the pathogenesis of many inflammatory, degenerative, and hyperproliferative diseases, including cancer. Previously, we revealed mechanisms of downstream signaling from ligand-activated RAGE, which recruits TIRAP/MyD88. Here, we showed that DNAX-activating protein 10 (DAP10), a transmembrane adaptor protein, also binds to RAGE. By artificial oligomerization of RAGE alone or RAGE-DAP10, we found that RAGE-DAP10 heterodimer formation resulted in a marked enhancement of Akt activation, whereas homomultimeric interaction of RAGE led to activation of caspase 8. Normal human epidermal keratinocytes exposed to S100A8/A9, a ligand for RAGE, at a nanomolar concentration mimicked the pro-survival response of RAGE-DAP10 interaction, although at a micromolar concentration, the cells mimicked the pro-apoptotic response of RAGE-RAGE. In transformed epithelial cell lines, A431 and HaCaT, in which endogenous DAP10 was overexpressed, and S100A8/A9, even at a micromolar concentration, led to cell growth and survival due to RAGE-DAP10 interaction. Functional blocking of DAP10 in the cell lines abrogated the Akt phosphorylation from S100A8/A9-activated RAGE, eventually leading to an increase in apoptosis. Finally, S100A8/A9, RAGE, and DAP10 were overexpressed in the psoriatic epidermis. Our findings indicate that the functional interaction between RAGE and DAP10 coordinately regulates S100A8/A9-mediated survival and/or apoptotic response of keratinocytes. PMID:25002577

  4. Myricetin inhibits advanced glycation end product (AGE)-induced migration of retinal pericytes through phosphorylation of ERK1/2, FAK-1, and paxillin in vitro and in vivo.

    Science.gov (United States)

    Kim, Young Sook; Kim, Junghyun; Kim, Ki Mo; Jung, Dong Ho; Choi, Sojin; Kim, Chan-Sik; Kim, Jin Sook

    2015-02-15

    Advanced glycation end products (AGE) have been implicated in the development of diabetic retinopathy. Characterization of the early stages of diabetic retinopathy is retinal pericytes loss, which is the result of pericytes migration. In this study, we investigated the pathological mechanisms of AGE on the migration of retinal pericytes and confirmed the inhibitory effect of myricetin on migration in vitro and in vivo. Migration assays of bovine retinal pericytes (BRP) were induced using AGE-BSA and phosphorylation of Src, ERK1/2, focal adhesion kinase (FAK-1) and paxillin were determined using immunoblot analysis. Sprague-Dawley rats (6 weeks old) were injected intravitreally with AGE-BSA and morphological and immunohistochemical analysis of p-FAK-1 and p-paxillin were performed in the rat retina. Immunoblot analysis and siRNA transfection were used to study the molecular mechanism of myricetin on BRP migration. AGE-BSA increased BRP migration in a dose-dependent manner via receptor for AGEs (RAGE)-dependent activation of the Src kinase-ERK1/2 pathway. AGE-BSA-induced migration was inhibited by an ERK1/2 specific inhibitor (PD98059), but not by p38 and Jun N-terminal kinase inhibitors. AGE-BSA increased FAK-1 and paxillin phosphorylation in a dose- and time-dependent manner. These increases were attenuated by PD98059 and ERK1/2 siRNA. Phosphorylation of FAK-1 and paxillin was increased in response to AGE-BSA-induced migration of rat retinal pericytes. Myricetin strongly inhibited ERK1/2 phosphorylation and significantly suppressed pericytes migration in AGE-BSA-injected rats. Our results demonstrate that AGE-BSA participated in the pathophysiology of retinal pericytes migration likely through the RAGE-Src-ERK1/2-FAK-1-paxillin signaling pathway. Furthermore, myricetin suppressed phosphorylation of ERK 1/2-FAK-1-paxillin and inhibited pericytes migration. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Glucagon-like peptide-1 receptor agonist inhibits asymmetric dimethylarginine generation in the kidney of streptozotocin-induced diabetic rats by blocking advanced glycation end product-induced protein arginine methyltranferase-1 expression.

    Science.gov (United States)

    Ojima, Ayako; Ishibashi, Yuji; Matsui, Takanori; Maeda, Sayaka; Nishino, Yuri; Takeuchi, Masayoshi; Fukami, Kei; Yamagishi, Sho-ichi

    2013-01-01

    Advanced glycation end products (AGEs) and their receptor (RAGE) play a role in diabetic nephropathy. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, contributes to diabetic nephropathy. We have found that glucagon-like peptide-1 (GLP-1) inhibits the AGE-induced inflammatory reactions in endothelial cells. However, effects of GLP-1 on the AGE-RAGE-ADMA axis are unknown. This study examined the effects of GLP-1 on reactive oxygen species (ROS) generation, gene expression of protein arginine methyltransfetase-1 (PRMT-1), an enzyme that mainly generates ADMA, and ADMA levels in human proximal tubular cells. Streptozotocin-induced diabetic rats received continuous i.p. infusion of 0.3 μg of vehicle or 1.5 μg of the GLP-1 analog exendin-4 per kilogram of body weight for 2 weeks. We further investigated whether and how exendin-4 treatment reduced ADMA levels and renal damage in streptozotocin-induced diabetic rats. GLP-1 inhibited the AGE-induced RAGE and PRMT-1 gene expression, ROS, and ADMA generation in tubular cells, which were blocked by small-interfering RNAs raised against GLP-1 receptor. Exendin-4 treatment decreased gene expression of Rage, Prmt-1, Icam-1, and Mcp-1 and ADMA level; reduced urinary excretions of 8-hydroxy-2'-deoxyguanosine and albumin; and improved histopathologic changes of the kidney in diabetic rats. Our present study suggests that GLP-1 receptor agonist may inhibit the AGE-RAGE-mediated ADMA generation by suppressing PRMT-1 expression via inhibition of ROS generation, thereby protecting against the development and progression of diabetic nephropathy. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  6. Effects of high glucose and advanced glycation end products on the expressions of sclerostin and RANKL as well as apoptosis in osteocyte-like MLO-Y4-A2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Ken-ichiro, E-mail: ken1nai@med.shimane-u.ac.jp; Yamaguchi, Toru, E-mail: yamaguch@med.shimane-u.ac.jp; Kanazawa, Ippei, E-mail: ippei.k@med.shimane-u.ac.jp; Sugimoto, Toshitsugu, E-mail: sugimoto@med.shimane-u.ac.jp

    2015-05-29

    In diabetes mellitus (DM), high glucose (HG) and advanced glycation end products (AGEs) are involved in bone quality deterioration. Osteocytes produce sclerostin and receptor activator of nuclear factor-kB ligand (RANKL) and regulate osteoblast and osteoclast function. However, whether HG or AGEs directly affect osteocytes and regulate sclerostin and RANKL production is unknown. Here, we examined the effects of HG, AGE2, and AGE3 on the expression of sclerostin and RANKL and on apoptosis in osteocyte-like MLO-Y4-A2 cells. Treatment of the cells with 22 mM glucose, 100 μg/mL either AGE2 or AGE3 significantly increased the expression of sclerostin protein and mRNA; however, both AGEs, but not glucose, significantly decreased the expression of RANKL protein and mRNA. Moreover, treatment of the cells with HG, AGE2, or AGE3 for 72 h induced significant apoptosis. These detrimental effects of HG, AGE2, and AGE3 on sclerostin and RANKL expressions and on apoptosis were antagonized by pretreatment of the cells with 10{sup −8} M human parathyroid hormone (PTH)-(1–34). Thus, HG and AGEs likely suppress bone formation by increasing sclerostin expression in osteocytes, whereas AGEs suppress bone resorption by decreasing RANKL expression. Together, these processes may cause low bone turnover in DM. In addition, HG and AGEs may cause cortical bone deterioration by inducing osteocyte apoptosis. PTH may effectively treat these pathological processes and improve osteocyte function. - Highlights: • AGEs are involved in bone quality deterioration in diabetes mellitus (DM). • AGEs increased sclerostin as well as apoptosis, and decreased RANKL in osteocytes. • The effects of AGEs on osteocyte function were antagonized by human PTH-(1–34). • AGEs may cause low bone turnover and cortical porosity in DM. • PTH may be effective in bone quality deterioration by improving osteocyte function.

  7. Advanced glycation end products upregulate lysyl oxidase and endothelin-1 in human aortic endothelial cells via parallel activation of ERK1/2-NF-κB and JNK-AP-1 signaling pathways.

    Science.gov (United States)

    Adamopoulos, Christos; Piperi, Christina; Gargalionis, Antonios N; Dalagiorgou, Georgia; Spilioti, Eliana; Korkolopoulou, Penelope; Diamanti-Kandarakis, Evanthia; Papavassiliou, Athanasios G

    2016-04-01

    Endothelial dysfunction involves deregulation of the key extracellular matrix (ECM) enzyme lysyl oxidase (LOX) and the vasoconstrictor protein, endothelin-1 (ET-1), whose gene expression can be modulated by the transcriptional activators nuclear factor kappa B (NF-κB) and activator protein-1 (AP-1). Advanced glycation end products (AGEs) present an aggravating factor of endothelial dysfunction which upon engagement to their receptor RAGE induce upregulation of mitogen-activated protein kinases (MAPKs), leading to NF-κB and AP-1 potentiation. We hypothesized that AGEs could induce NF-κΒ- and AP-1-dependent regulation of LOX and ET-1 expression via the AGE/RAGE/MAPK signaling axis. Western blot, real-time qRT-PCR, FACS analysis and electrophoretic mobility-shift assays were employed in human aortic endothelial cells (HAECs) following treatment with AGE-bovine serum albumin (AGE-BSA) to investigate the signaling pathway towards this hypothesis. Furthermore, immunohistochemical analysis of AGEs, RAGE, LOX and ET-1 expression was conducted in aortic endothelium of a rat experimental model exposed to high- or low-AGE content diet. HAECs exposed to AGE-BSA for various time points exhibited upregulation of LOX and ET-1 mRNA levels in a dose- and time-dependent manner. Exposure of HAECs to AGE-BSA also showed specific elevation of phospho(p)-ERK1/2 and p-JNK levels in a dose- and time-dependent fashion. AGE administration significantly increased NF-κΒ- and AP-1-binding activity to both LOX and ET-1 cognate promoter regions. Moreover, LOX and ET-1 overexpression in rat aortic endothelium upon high-AGE content diet confirmed the functional interrelation of these molecules. Our findings demonstrate that AGEs trigger NF-κΒ- and AP-1-mediated upregulation of LOX and ET-1 via the AGE/RAGE/MAPK signaling cascade in human endothelial cells, thus contributing to distorted endothelial homeostasis by impairing endothelial barrier function, altering ECM biomechanical properties

  8. Pathological Significance of Mitochondrial Glycation

    Directory of Open Access Journals (Sweden)

    Pamela Boon Li Pun

    2012-01-01

    Full Text Available Glycation, the nonenzymatic glycosylation of biomolecules, is commonly observed in diabetes and ageing. Reactive dicarbonyl species such as methylglyoxal and glyoxal are thought to be major physiological precursors of glycation. Because these dicarbonyls tend to be formed intracellularly, the levels of advanced glycation end products on cellular proteins are higher than on extracellular ones. The formation of glycation adducts within cells can have severe functional consequences such as inhibition of protein activity and promotion of DNA mutations. Although several lines of evidence suggest that there are specific mitochondrial targets of glycation, and mitochondrial dysfunction itself has been implicated in disease and ageing, it is unclear if glycation of biomolecules specifically within mitochondria induces dysfunction and contributes to disease pathology. We discuss here the possibility that mitochondrial glycation contributes to disease, focussing on diabetes, ageing, cancer, and neurodegeneration, and highlight the current limitations in our understanding of the pathological significance of mitochondrial glycation.

  9. Using an enzymatic galactose assay to detect lactose glycation extents of two proteins caseinate and soybean protein isolate via the Maillard reaction.

    Science.gov (United States)

    Wang, Xiao-Peng; Zhao, Xin-Huai

    2017-06-01

    Glycation of food proteins via the Maillard reaction has been widely studied in the recent years; however, the amount of saccharide connected to proteins is usually not determined. An enzymatic galactose assay was proposed firstly in this study to detect lactose glycation extents of caseinate and soybean protein isolate (SPI) during the Maillard reaction at two temperatures and different times. The separated glycated proteins were hydrolysed to release galactose necessary for the enzymatic assay and glycation calculation. Caseinate and SPI both obtained the highest lactose glycation extents at 100 °C or 121 °C by a reaction time of 180 or 20 min. Short- and long-time reaction resulted in lower glycation extents. During the reaction, three chemical indices (absorbences at 294/490 nm and fluorescence intensities) of reaction mixtures increased continually, but another index reactable NH 2 of glycated proteins showed the opposite trend. In general, changing profiles of the four indices were inconsistent with those profiles of lactose glycation extents of glycated proteins, implying practical limitation of the four indices in studies. This proposed enzymatic assay could directly detect lactose glycation of the two proteins, and thus was more useful than the four chemical indices to monitor glycation of the two proteins. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Effect of glycated insulin on the blood-brain barrier permeability: An in vitro study.

    Science.gov (United States)

    Shahriyary, Leila; Riazi, Gholamhossein; Lornejad, Mohammad Reza; Ghezlou, Mansoureh; Bigdeli, Bahareh; Delavari, Behdad; Mamashli, Fatemeh; Abbasi, Shayan; Davoodi, Jamshid; Saboury, Ali Akbar

    2018-02-11

    Alteration in permeability of blood-brain barrier (BBB) is of immense importance in the pathogenesis of diabetes-related central nervous system disorders. Considering the presence of glycated insulin in plasma of type 2 diabetic patients, we hypothesized that glycated insulin could induce changes in paracellular permeability in BBB. Therefore, the authors decided to study the effect of glycated insulin on paracellular permeability in a BBB model. Furthermore, the change induced in insulin conformation upon glycation was studied. In this study, the structural modification was detected by fluorescence-based assays, circular dichroism, and dynamic light scattering. Cell proliferation, apoptosis, and production of ROS in astrocytes and HUVEC cells were analyzed by MTT, flow cytometric, and spectrofluorometric assays, respectively. The permeability measurement was performed by Lucifer yellow and FITC-Dextran. According to our results, glycated insulin presented altered conformation and more exposed hydrophobic patches than insulin. Besides, formation of oligomeric species and advanced glycated end products (AGEs) were determined. Additionally, lower cell viability, higher apoptosis induction, and more ROS production were detected upon treatment of cells with glycated insulin. Furthermore, glycated insulin leading to increased Lucifer yellow and FITC-dextran transportation across the BBB model which could result from ROS producing and apoptosis-inducing activities of AGE-insulin. Copyright © 2018. Published by Elsevier Inc.

  11. Aptasensor based optical detection of glycated albumin for diabetes mellitus diagnosis

    Science.gov (United States)

    Ghosh, Shreya; Datta, Debopam; Cheema, Mehar; Dutta, Mitra; Stroscio, Michael A.

    2017-10-01

    Glycated albumin (GA) has been reported as an important biomarker for diabetes mellitus. This study investigates an optical sensor comprised of deoxyribonucleic acid (DNA) aptamer, semiconductor quantum dot and gold (Au) nanoparticle for the detection of GA. The system functions as a ‘turn on’ sensor because an increase in photoluminescence intensity is observed upon the addition of GA to the sensor. This is possibly because of the structure of the DNA aptamer, which folds to form a large hairpin loop before the addition of the analyte and is assumed to open up after the addition of target to the sensor in order to bind to GA. This pushes the quantum dot and the Au nanoparticle away causing an increase in photoluminescence. A linear increase in photoluminescence intensity and quenching efficiency of the sensor is observed as the GA concentration is varied between 0-14 500 nM. Time based photoluminescence studies with the sensor show the decrease in binding rate of the aptamer to the target within a specific time period. The sensor was found to have a higher selectivity towards GA than other control proteins. Further investigation of this simple sensor with greater number of clinical samples can open up avenues for an efficient diagnosis and monitoring of diabetes mellitus when used in conjunction with the traditional method of glucose level monitoring.

  12. The isotopic exchange of oxygen as a tool for detection of the glycation sites in proteins.

    Science.gov (United States)

    Kijewska, Monika; Stefanowicz, Piotr; Kluczyk, Alicja; Szewczuk, Zbigniew

    2011-12-15

    A nonenzymatic reaction of reducing sugars with the free amino group located at the N terminus of the polypeptide chain or in the lysine side chain results in glycation of proteins. The fragments of glycated proteins obtained by enzymatic hydrolysis could be considered as the biomarkers of both the aging process and diabetes mellitus. Here we propose a new method for the identification of peptide-derived Amadori products in the enzymatic digest of glycated proteins. The products of enzymatic hydrolysis of the model protein ubiquitin were incubated with H(2)(18)O under microwave activation. We observed that at these conditions the Amadori compounds selectively exchange one oxygen atom in the hexose moiety. The characteristic isotopic pattern of Amadori products treated with H(2)(18)O allows fast and convenient identification of this group of compounds, whereas nonglycated peptides are not susceptible to isotopic exchange. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Inhibition of glucose- and fructose-mediated protein glycation by infusions and ethanolic extracts of ten culinary herbs and spices

    Directory of Open Access Journals (Sweden)

    Jugjeet Singh Ramkissoon

    2016-06-01

    Conclusions: The higher rate of fluorescence generation by fructation suggests that glycation by fructose deserves much attention as a glycating agent. Data herein showed that the extracts inhibited GMG and FMG. Thus, these edible plants could be a natural source of antioxidants and anti-glycation agent for preventing advanced glycation end-products-mediated complications.

  14. Detection of serum carbaminohemoglobin and glycated hemoglobin contents in diabetic nephropathy patients with hemodialysis and assessment of their clinical value

    Directory of Open Access Journals (Sweden)

    Ming-Ai Song

    2016-06-01

    Full Text Available Objective: To analyze the serum carbaminohemoglobin and glycated hemoglobin contents in diabetic nephropathy patients with hemodialysis as well as their clinical value. Methods: A total of 84 cases of diabetic nephropathy patients who received hemodialysis treatment in our hospital from August 2012 to November 2015 were selected as dialysis group, 76 cases of diabetic nephropathy patients without hemodialysis who received treatment in our hospital during the same period were selected as non-dialysis group, and 88 cases of people without diabetes or renal dysfunction who received physical examination in our hospital during the same period were selected as healthy control group. Serum carbaminohemoglobin and glycated hemoglobin contents as well as serum nutrition, dialysis adequacy and disease severity-related indicators of three groups were detected. Results: Serum CarHb and HbA1c contents of dialysis group were lower than those of non-dialysis group; BSF, TSF, MAMC and AMA values of dialysis group were higher than those of non-dialysis group; serum iPTH, β 2-MG, PTX3 and OPN levels of dialysis group were lower than those of non-dialysis group while Kt/V level was higher than that of non-dialysis group; sTfR, IGF-1 and NF-κBp65 values of dialysis group were lower than those of non-dialysis group while APN, Hepcidin and GH values were higher than those of non-dialysis group; serum CarHb and HbA1c levels of dialysis group were positively correlated with iPTH, β2-MG, PTX3, OPN, sTfR, IGF-1 and NF-κBp65, and negatively correlated with BSF, TSF, MAMC, AMA, Kt/V, APN, Hepcidin and GH. Conclusion: Serum carbaminohemoglobin and glycated hemoglobin contents in diabetic nephropathy patients with hemodialysis can be the direct indexes to judge disease severity, dialysis effectiveness, etc, and have positive significance in guiding the treatment of disease.

  15. Potent protein glycation inhibition of plantagoside in Plantago major seeds.

    Science.gov (United States)

    Matsuura, Nobuyasu; Aradate, Tadashi; Kurosaka, Chihiro; Ubukata, Makoto; Kittaka, Shiho; Nakaminami, Yuri; Gamo, Kanae; Kojima, Hiroyuki; Ohara, Mitsuharu

    2014-01-01

    Plantagoside (5,7,4',5'-tetrahydroxyflavanone-3'-O-glucoside) and its aglycone (5,7,3',4',5'-pentahydroxyflavanone), isolated from a 50% ethanol extract of Plantago major seeds (Plantaginaceae), were established to be potent inhibitors of the Maillard reaction. These compounds also inhibited the formation of advanced glycation end products in proteins in physiological conditions and inhibited protein cross-linking glycation. These results indicate that P. major seeds have potential therapeutic applications in the prevention of diabetic complications.

  16. Characterization and cytological effects of a novel glycated gelatine substrate

    International Nuclear Information System (INIS)

    Boonkaew, Benjawan; Supaphol, Pitt; Tompkins, Kevin; Manokawinchoke, Jeeranan; Pavasant, Prasit

    2014-01-01

    Hyperglycemia in diabetes results in the glycation of long-lived proteins. Protein glycation leads to the formation of advanced glycation end products (AGEs), which are implicated in delayed wound healing and other diabetes-associated pathologies, one of which is periodontal disease. Research into the mechanisms by which glycated long-lived proteins such as collagen exert their effects can allow for the understanding of diabetic pathologies and the development of appropriate treatments. However, the high cost of purified protein can be a limitation for many laboratories around the world. The objective of this study was to develop a low-cost in vitro model of glycated gelatine as an alternative to the glycated collagen model. We investigated the glycation of gelatine type A, a denatured form of collagen, which is low-cost and abundantly available. In this study, gelatine was incubated for 7 days with ribose or methylglyoxal (MG). Cross-linking, autofluorescence and UV–Vis spectrophotometry assays were performed and indicated a dose-dependent linear increase in cross-linking and autofluorescence of gelatine by ribose and MG. MG produced more cross-linking compared to ribose at the same concentrations. The UV–Vis spectra of the glycated gelatines confirmed the presence of AGE fluorophores. Because diabetes is a risk factor for periodontal disease, the effect of the glycated substrates on the basic behaviour of human periodontal ligament (HPDL) cells was evaluated. Glycation dose dependently reduced HPDL attachment and cell spreading, indicating that the novel glycated gelatine substrate affects cell behaviour. These results show that gelatine glycated with ribose or MG can be used as low-cost in vitro models to study the effects of protein glycation on cell behaviour in diabetes and ageing. (paper)

  17. CAN THE END PRODUCTS OF ANAEROBIC METABOLISM ...

    African Journals Online (AJOL)

    This study was undertaken to investigate whether the accumulation of end products of anaerobic metabolism can be used as an early indicator of deteriorating conditions during transport of live abalone Haliotis midae. A first series of experiments revealed that the enzyme tauropine dehydrogenase, responsible for the ...

  18. The plasma level of soluble receptor for advanced glycation end ...

    African Journals Online (AJOL)

    The plasma level of soluble receptor for advanced glycation end products in systemic lupus erythematosus patients and its relation to disease activity. Anna Nashaat Abou-Raya, Maher Abdel Nabi Kamel, Eman Abdel Ghani Sayed, Ahmed Abdel Hamid El-Sharkawy ...

  19. Effects of advanced glycation end-product inhibition and cross-link breakage in diabetic rats

    DEFF Research Database (Denmark)

    Oturai, P S; Christensen, M; Rolin, B

    2000-01-01

    -albumin, was induced by diabetes. NNC39-0028 did not affect this abnormality. This study demonstrated a pharmacological inhibition of collagen solubility alterations in diabetic rats without affecting diabetes-induced pathophysiology such as the increase in UAE or albumin clearance. Treatment with PTB, a specific...

  20. Accumulation of advanced glycation end products decreases collagen turnover by bovine chondrocytes

    NARCIS (Netherlands)

    Groot, J. de; Verzijl, N.; Budde, M.; Bijlsma, J.W.J.; Lafeber, F.P.J.G.; TeKoppele, J.M.

    2001-01-01

    The integrity of the collagen network is essential for articular cartilage to fulfill its function in load support and distribution. Damage to the collagen network is one of the first characteristics of osteoarthritis. Since extensive collagen damage is considered irreversible, it is crucial that

  1. Skin Autofluorescence as Marker of Tissue Advanced Glycation End-Products Accumulation in Formerly Preeclamptic Women

    NARCIS (Netherlands)

    Coffeng, S.M.; Blaauw, Judith; Souwer, E.T.; Rakhorst, G.; Smit, A.J.; Graaff, R.; van Doormaal, J.J.; Aarnoudse, J.G.; Faas, M.M.; van Pampus, Maria

    2011-01-01

    Condensation. In women with a history of preeclampsia skin autofluorescence as marker of tissue AGEs accumulation is increased, supporting a common causal metabolic or vascular link between preeclampsia and cardiovascular diseases. Objective. To investigate whether skin autofluorescence (AF), as

  2. Soluble receptor for advanced glycation end products (sRAGE) and ...

    African Journals Online (AJOL)

    Egyptian Journal of Medical Human Genetics ... Patients with disease duration less than 5 years, connective tissue disease, liver dysfunction, or apparent cardiovascular disease and those on lipid lowering ... Laboratory investigations included; HbA1c%, urinary albumin excretion (UAE), fasting lipid profile and sRAGE.

  3. Advanced glycation end product (AGE) accumulation in the skin is associated with depression : The maastricht study

    NARCIS (Netherlands)

    Van Dooren, F.E.P.; Pouwer, F.; Schalkwijk, C.G.; Sep, S.J.S.; Stehouwer, C.D.A.; Henry, R.M.A.; Dagnelie, P.C.; Schaper, N.C.; Van Der Kallen, C.J.H.; Koster, A.; Denollet, J.K.L.; Verhey, F.R.J.; Schram, M.T.

    2017-01-01

    Background: depression is a highly prevalent disease with a high morbidity and mortality risk. Its pathophysiology is not entirely clear. However, type 2 diabetes is an important risk factor for depression. One mechanism that may explain this association may include the formation of advanced

  4. Does hepatitis C increase the accumulation of advanced glycation end products in haemodialysis patients?

    NARCIS (Netherlands)

    Arsov, Stefan; Graaff, Reindert; Morariu, Aurora M.; van Oeveren, Wim; Smit, Andries J.; Busletic, Irena; Trajcevska, Lada; Selim, Gjulsen; Dzekova, Pavlina; Stegmayr, Bernd; Sikole, Aleksandar; Rakhorst, Gerhard

    Methods. AGE accumulation was measured by means of skin autofluorescence (AF) in 92 haemodialysis (HD) patients and 93 age-matched healthy controls. In the HD patients, CVD-related biochemical variables were also measured. The HD patients were tested for hepatitis C virus (HCV) antibodies and

  5. Advanced glycation end-product pentosidine accumulates in various tissues of rats with high fructose intake

    Czech Academy of Sciences Publication Activity Database

    Mikulíková, Kateřina; Eckhardt, Adam; Kuneš, Jaroslav; Zicha, Josef; Mikšík, Ivan

    2008-01-01

    Roč. 57, č. 1 (2008), s. 89-94 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA203/05/2539; GA ČR(CZ) GA305/08/0108 Institutional research plan: CEZ:AV0Z50110509 Keywords : collagen * pentosidine * ages Subject RIV: CE - Biochemistry Impact factor: 1.653, year: 2008

  6. Potent Protein Glycation Inhibition of Plantagoside in Plantago major Seeds

    Directory of Open Access Journals (Sweden)

    Nobuyasu Matsuura

    2014-01-01

    Full Text Available Plantagoside (5,7,4′,5′-tetrahydroxyflavanone-3′-O-glucoside and its aglycone (5,7,3′,4′,5′-pentahydroxyflavanone, isolated from a 50% ethanol extract of Plantago major seeds (Plantaginaceae, were established to be potent inhibitors of the Maillard reaction. These compounds also inhibited the formation of advanced glycation end products in proteins in physiological conditions and inhibited protein cross-linking glycation. These results indicate that P. major seeds have potential therapeutic applications in the prevention of diabetic complications.

  7. Monotopic modifications derived from in vitro glycation of albumin with ribose

    Czech Academy of Sciences Publication Activity Database

    Pataridis, Statis; Šťastná, Zdeňka; Sedláková, Pavla; Mikšík, Ivan

    2013-01-01

    Roč. 34, č. 12 (2013), s. 1757-1763 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA203/08/1428 Institutional support: RVO:67985823 Keywords : advanced glycation end product (AGE) * albumin * CE-MS * glycation * LC-MS/MS Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.161, year: 2013

  8. Glycation promotes the formation of genotoxic aggregates in glucose oxidase.

    Science.gov (United States)

    Khan, Taqi Ahmed; Amani, Samreen; Naeem, Aabgeena

    2012-09-01

    This study investigates the effect of pentose sugars (ribose and arabinose) on the structural and chemical modifications in glucose oxidase (GOD) as well as genotoxic potential of this modified form. An intermediate state of GOD was observed on day 12 of incubation having CD minima peaks at 222 and 208 nm, characteristic of α-helix and a few tertiary contacts with altered tryptophan environment and high ANS binding. All these features indicate the existence of molten globule state of the GOD with ribose and arabinose on day 12. GOD on day 15 of incubation forms β structures as revealed by CD and FTIR which may be due to its aggregation. Furthermore, GOD on day 15 showed a remarkable increase in Thioflavin T fluorescence at 485 nm. Comet assay of lymphocytes and plasmid nicking assay in presence of glycated GOD show DNA damage which confirmed the genotoxicity of advance glycated end products. Hence, our study suggests that glycated GOD results in the formation of aggregates and the advanced glycated end products, which are genotoxic in nature.

  9. Evaluation of a reference material for glycated haemoglobin

    NARCIS (Netherlands)

    Weykamp, CW; Penders, TJ; Muskiet, FAJ; vanderSlik, W

    The use of lyophilized blood as a reference material for glycated haemoglobin was investigated with respect to IFCC criteria for calibrators and control materials. Ninety-two laboratories, using 11 methods, detected no changes in glycated haemoglobin content when the lyophilizate was stored for one

  10. Alteration of human serum albumin tertiary structure induced by glycation. Spectroscopic study.

    Science.gov (United States)

    Szkudlarek, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J; Sułkowska, A

    2016-01-15

    The modification of human serum albumin (HSA) structure by non-enzymatic glycation is one of the underlying factors that contribute to the development of complications of diabetes and neurodegenerative diseases. The aim of the present work was to estimate how glycation of HSA altered its tertiary structure. Changes of albumin conformation were investigated by comparison of glycated (gHSA) and non-glycated human serum albumin (HSA) absorption spectra, red edge excitation shift (REES) and synchronous spectra. Effect of glycation on human serum albumin tertiary structure was also investigated by (1)H NMR spectroscopy. Formation of gHSA Advanced Glycation End-products (AGEs) caused absorption of UV-VIS light between 310 nm and 400 nm while for non-glycated HSA in this region no absorbance has been registered. Analysis of red edge excitation shift effect allowed for observation of structural changes of gHSA in the hydrophobic pocket containing the tryptophanyl residue. Moreover changes in the microenvironment of tryptophanyl and tyrosyl residues brought about AGEs on the basis of synchronous fluorescence spectroscopy have been confirmed. The influence of glycation process on serum albumin binding to 5-dimethylaminonaphthalene-1-sulfonamide (DNSA), 2-(p-toluidino) naphthalene-6-sulfonic acid (TNS), has been studied. Fluorescence analysis showed that environment of both binding site I and II is modified by galactose glycation. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Preserving brain function in aging: The anti-glycative potential of berry fruit

    Science.gov (United States)

    Advanced glycation end-products (AGEs) are naturally occurring macromolecules that are formed in vivo by the non-enzymatic modification of proteins, lipids, or nucleic acids by sugar, even in the absence of hyperglycemia. In the diet, AGEs are found in animal products, and additional AGEs are produc...

  12. Commercial processed soy-based food product contains glycated and glycoxidated lunasin proteoforms.

    Science.gov (United States)

    Serra, Aida; Gallart-Palau, Xavier; See-Toh, Rachel Su-En; Hemu, Xinya; Tam, James P; Sze, Siu Kwan

    2016-05-18

    Nutraceuticals have been proposed to exert positive effects on human health and confer protection against many chronic diseases. A major bioactive component of soy-based foods is lunasin peptide, which has potential to exert a major impact on the health of human consumers worldwide, but the biochemical features of dietary lunasin still remain poorly characterized. In this study, lunasin was purified from a soy-based food product via strong anion exchange solid phase extraction and then subjected to top-down mass spectrometry analysis that revealed in detail the molecular diversity of lunasin in processed soybean foods. We detected multiple glycated proteoforms together with potentially toxic advanced glycation end products (AGEs) derived from lunasin. In both cases, modification sites were Lys24 and Lys29 located at the helical region that shows structural homology with a conserved region of chromatin-binding proteins. The identified post-translational modifications may have an important repercussion on lunasin epigenetic regulatory capacity. Taking together, our results demonstrate the importance of proper chemical characterization of commercial processed food products to assess their impact on consumer's health and risk of chronic diseases.

  13. Glycation of Lysozyme by Glycolaldehyde Provides New Mechanistic Insights in Diabetes-Related Protein Aggregation.

    Science.gov (United States)

    Mariño, Laura; Maya-Aguirre, Carlos Andrés; Pauwels, Kris; Vilanova, Bartolomé; Ortega-Castro, Joaquin; Frau, Juan; Donoso, Josefa; Adrover, Miquel

    2017-04-21

    Glycation occurs in vivo as a result of the nonenzymatic reaction of carbohydrates (and/or their autoxidation products) with proteins, DNA, or lipids. Protein glycation causes loss-of-function and, consequently, the development of diabetic-related diseases. Glycation also boosts protein aggregation, which can be directly related with the higher prevalence of aggregating diseases in diabetic people. However, the molecular mechanism connecting glycation with aggregation still remains unclear. Previously we described mechanistically how glycation of hen egg-white lysozyme (HEWL) with ribose induced its aggregation. Here we address the question of whether the ribose-induced aggregation is a general process or it depends on the chemical nature of the glycating agent. Glycation of HEWL with glycolaldehyde occurs through two different scenarios depending on the HEWL concentration regime (both within the micromolar range). At low HEWL concentration, non-cross-linking fluorescent advanced glycation end-products (AGEs) are formed on Lys side chains, which do not change the protein structure but inhibit its enzymatic activity. These AGEs have little impact on HEWL surface hydrophobicity and, therefore, a negligible effect on its aggregation propensity. Upon increasing HEWL concentration, the glycation mechanism shifts toward the formation of intermolecular cross-links, which triggers a polymerization cascade involving the formation of insoluble spherical-like aggregates. These results notably differ with the aggregation-modulation mechanism of ribosylated HEWL directed by hydrophobic interactions. Additionally, their comparison constitutes the first experimental evidence showing that the mechanism underlying the aggregation of a glycated protein depends on the chemical nature of the glycating agent.

  14. Products by Glycation Process

    Directory of Open Access Journals (Sweden)

    Liliana Ortega

    2015-01-01

    Full Text Available The antioxidant properties of sweet and acid whey products were incremented by polymerization of their proteins by glycation of whey protein concentrates (WPC and their hydrolyzates (WPCH with ribose and glucose in individual experiments under similar concentration. Heating at 50°C during 20 h maximum and pH 7 and pH 9 were used in all tests. The higher activity was found in WPC glycosylates products with ribose at pH 7 and heating during 10–15 h. In comparable form, antioxidant activity in WPCH was incremented by prior hydrolysis to glycation with 25–45% of hydrolysis degree. Further functional properties of whey proteins (solubility, emulsion, and foam were also improved by the polymerization with ribose. The color of polymerized products due to Maillard reactions was associated with antioxidant activity of each compound; however comparative color in glycosylates products with glucose and ribose did not show this effect.

  15. Targeted reduction of advanced glycation improves renal function in obesity

    DEFF Research Database (Denmark)

    Harcourt, Brooke E; Sourris, Karly C; Coughlan, Melinda T

    2011-01-01

    Obesity is highly prevalent in Western populations and is considered a risk factor for the development of renal impairment. Interventions that reduce the tissue burden of advanced glycation end-products (AGEs) have shown promise in stemming the progression of chronic disease. Here we tested...... if treatments that lower tissue AGE burden in patients and mice would improve obesity-related renal dysfunction. Overweight and obese individuals (body mass index (BMI) 26-39¿kg/m(2)) were recruited to a randomized, crossover clinical trial involving 2 weeks each on a low- and a high-AGE-containing diet. Renal...... function and an inflammatory profile (monocyte chemoattractant protein-1 (MCP-1) and macrophage migration inhibitory factor (MIF)) were improved following the low-AGE diet. Mechanisms of advanced glycation-related renal damage were investigated in a mouse model of obesity using the AGE...

  16. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis

    Science.gov (United States)

    Szkudlarek, A.; Sułkowska, A.; Maciążek-Jurczyk, M.; Chudzik, M.; Równicka-Zubik, J.

    2016-01-01

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors - glycation of HSA - occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSAGLC) with HSA glycated by fructose (gHSAFRC). We focused on presenting the differences between gHSAFRC and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335 nm and λem 420 nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSAFRC is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSAFRC becomes less accessible for the negatively charged quencher (I-), KSV value is smaller for gHSAFRC than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the unmodified serum

  17. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis.

    Science.gov (United States)

    Szkudlarek, A; Sułkowska, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J

    2016-01-05

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors --glycation of HSA--occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSA(GLC)) with HSA glycated by fructose (gHSA(FRC)). We focused on presenting the differences between gHSA(FRC) and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335nm and λem 420nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSA(FRC) is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSA(FRC) becomes less accessible for the negatively charged quencher (I(-)), KSV value is smaller for gHSA(FRC) than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the

  18. Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

    Directory of Open Access Journals (Sweden)

    Grażyna E Sroga

    Full Text Available To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs at the levels that corresponded to approx. 25-30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation or ribose (ribosylation. Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women. More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples. Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar

  19. Dietary advanced glycation endproducts

    DEFF Research Database (Denmark)

    Poulsen, Malene Wibe

    High heat cooking induces flavor, aroma, and color of food, but leads to formation of advanced glycation endproducts (AGEs) by the Maillard reaction. In addition to the formation in food, AGEs are also formed in vivo, and increased endogenous formation of AGEs has been linked to diabetic complica......High heat cooking induces flavor, aroma, and color of food, but leads to formation of advanced glycation endproducts (AGEs) by the Maillard reaction. In addition to the formation in food, AGEs are also formed in vivo, and increased endogenous formation of AGEs has been linked to diabetic...... complications. A potential pathophysiological role of dietary AGEs in type 2 diabetes and cardiovascular disease has been discussed, as the contribution of dietary AGEs has been estimated to be larger than the amount of endogenously formed AGEs. Furthermore, the increased mortality associated with type 2...... for biological effects of high heat-treated diets in humans. Studies with well-defined AGEs should be undertaken in order to advance our understanding of biological effects of specific AGEs....

  20. New Locus for Skin Intrinsic Fluorescence in Type 1 Diabetes Also Associated With Blood and Skin Glycated Proteins

    NARCIS (Netherlands)

    Roshandel, Delnaz; Klein, Ronald; Klein, Barbara E. K.; Wolffenbuttel, Bruce H. R.; van der Klauw, Melanie M.; van Vliet-Ostaptchouk, Jana V.; Atzmon, Gil; Ben-Avraham, Danny; Crandall, Jill P.; Barzilai, Nir; Bull, Shelley B.; Canty, Angelo J.; Hosseini, S. Mohsen; Hiraki, Linda T.; Maynard, John; Sell, David R.; Monnier, Vincent M.; Cleary, Patricia A.; Braffett, Barbara H.; Paterson, Andrew D.

    Skin fluorescence (SF) noninvasively measures advanced glycation end products (AGEs) in the skin and is a risk indicator for diabetes complications. N-acetyltransferase 2 (NAT2) is the only known locus influencing SF. We aimed to identify additional genetic loci influencing SF in type 1 diabetes

  1. Vessel Ultrasound Sonographic Assessment of Soluble Receptor for Advanced Glycation End Products Efficacy in a Rat Balloon Injury Model

    Directory of Open Access Journals (Sweden)

    Hyun-Jin Tae, DVM, PhD

    2014-12-01

    Conclusions: Sonograph results are consistent with those obtained from histology; that is, sRAGE produced in Chinese hamster ovary cells has significantly higher efficacy than insect cell-originated sRAGE cells.

  2. Quercetin inhibits advanced glycation end product formation via chelating metal ions, trapping methylglyoxal, and trapping reactive oxygen species.

    Science.gov (United States)

    Bhuiyan, Mohammad Nazrul Islam; Mitsuhashi, Shinya; Sigetomi, Kengo; Ubukata, Makoto

    2017-05-01

    Physiological concentration of Mg 2+ , Cu 2+ , and Zn 2+ accelerated AGE formation only in glucose-mediated conditions, which was effectively inhibited by chelating ligands. Only quercetin (10) inhibited MGO-mediated AGE formation as well as glucose- and ribose-mediated AGE formation among 10 polyphenols (1-10) tested. We performed an additional structure-activity relationship (SAR) study on flavanols (10, 11, 12, 13, and 14). Morin (12) and kaempherol (14) showed inhibitory activity against MGO-mediated AGE formation, whereas rutin (11) and fisetin (13) did not. These observations indicate that 3,5,7,4'-tetrahydroxy and 4-keto groups of 10 are important to yield newly revised mono-MGO adducts (16 and 17) and di-MGO adduct (18) having cyclic hemiacetals, while 3'-hydroxy group is not essential. We propose here a comprehensive inhibitory mechanism of 10 against AGE formation including chelation effect, trapping of MGO, and trapping of reactive oxygen species (ROS), which leads to oxidative degradation of 18 to 3,4-dihydroxybenzoic acid (15) and other fragments.

  3. Advanced glycation end products cause increased CCN family and extracellular matrix gene expression in the diabetic rodent retina

    NARCIS (Netherlands)

    Hughes, J. M.; Kuiper, E. J.; Klaassen, I.; Canning, P.; Stitt, A. W.; van Bezu, J.; Schalkwijk, C. G.; van Noorden, C. J. F.; Schlingemann, R. O.

    2007-01-01

    Aims/hypothesis Referred to as CCN, the family of growth factors consisting of cystein-rich protein 61 (CYR61, also known as CCN1), connective tissue growth factor (CTGF, also known as CCN2), nephroblastoma overexpressed gene (NOV, also known as CCN3) and WNT1-inducible signalling pathway proteins

  4. The distribution of advanced glycation end products and their receptor in the gastrointestinal tract in the rats

    DEFF Research Database (Denmark)

    Chen, Pengmin; Zhao, Jingbo; Gregersen, Hans

    2012-01-01

    and squamous epithelial cells. In the stomach, AGEs were mainly distributed in parietal cells, and RAGE was strongly expressed in chief cells, mast cells and neurons in ganglia, moderately in parietal cells, and mildly in surface mucous cells. In the intestine, colon and rectum, AGEs and RAGE were distributed....... RAGE is also distributed in chief cells, mast cells, parietal cells and surface mucous cells in the stomach and neurons in the whole GI tract....

  5. Effect of cephalandra indica against advanced glycation end products, sorbitol accumulation and aldose reductase activity in homoeopathic formulation

    Directory of Open Access Journals (Sweden)

    Lalit Kishore

    2018-01-01

    Full Text Available Background: Extreme generation of free radicals leads to oxidative stress which has been apprehensive in several disease processes such as diabetic complications and vascular and neurodegenerative diseases. Objective: The present study was designed to evaluate the potential of homoeopathic preparations of Cephalandra indica L. against oxidative stress. Materials and Methods: Potencies of Cephalandra indica (mother tincture, 6C and 30C were procured from Dr. Willmar Schwabe India Pvt. Ltd. The antioxidant activity of Cephalandra indica was evaluated by employing various in vitro antioxidant methods. Results: The total phenol content was found to be 1905, 849 and 495 mg/g gallic acid equivalents in mother tincture, 6C and 30C of Cephalandra indica and total antioxidant capacity was found to be 2710, 759 and 510 μM/g ascorbic acid equivalents, respectively. Mother tincture, 6C and 30C of Cephalandra indica was found to have strong reducing power, 2,2-diphenyl-1-picrylhydrazyl radical, hydrogen peroxide, nitric oxide and superoxide radical scavenging activity. Percentage inhibition of AGEs formation by mother tincture, 6C and 30C of Cephalandra indica (10–50 μl was found to be 30.34%–91.77%, 29.98%–65.71% and 33.05%–57.75%, respectively. Mother tincture, 6C and 30C of Cephalandra indica showed inhibitory effect against sorbitol accumulation with IC50value of 26.12 μl, 203.10 μl and 897.3 μl, respectively, whereas, in aldose reductase inhibition assay, the IC50value was 32.54 μl, 175.02 μl and 834.34 μl, respectively. Conclusion: The results revealed that homoeopathic preparations of Cephalandra indica exhibit protective effect against oxidative stress.

  6. Increased accumulation of skin advanced glycation end-products precedes and correlates with clinical manifestation of diabetic neuropathy

    NARCIS (Netherlands)

    Meerwaldt, R; Links, TP; Graaff, R; Hoogenberg, K; Lefrandt, JD; Baynes, JW; Gans, ROB; Smit, AJ

    Aims/hypothesis: The accumulation of AGE is related to the progression of the renal, retinal and vascular complications of diabetes. However, the relationship with diabetic neuropathy remains unclear. We recently showed that skin autofluorescence, measured non-invasively with an AutoFluorescence

  7. Cloning, characterisation, and comparative quantitative expression analyses of receptor for advanced glycation end products (RAGE) transcript forms.

    Science.gov (United States)

    Sterenczak, Katharina A; Willenbrock, Saskia; Barann, Matthias; Klemke, Markus; Soller, Jan T; Eberle, Nina; Nolte, Ingo; Bullerdiek, Jörn; Murua Escobar, Hugo

    2009-04-01

    RAGE is a member of the immunoglobulin superfamily of cell surface molecules playing key roles in pathophysiological processes, e.g. immune/inflammatory disorders, Alzheimer's disease, diabetic arteriosclerosis and tumourigenesis. In humans 19 naturally occurring RAGE splicing variants resulting in either N-terminally or C-terminally truncated proteins were identified and are lately discussed as mechanisms for receptor regulation. Accordingly, deregulation of sRAGE levels has been associated with several diseases e.g. Alzheimer's disease, Type 1 diabetes, and rheumatoid arthritis. Administration of recombinant sRAGE to animal models of cancer blocked tumour growth successfully. In spite of its obvious relationship to cancer and metastasis data focusing sRAGE deregulation and tumours is rare. In this study we screened a set of tumours, healthy tissues and various cancer cell lines for RAGE splicing variants and analysed their structure. Additionally, we analysed the ratio of the mainly found transcript variants using quantitative Real-Time PCR. In total we characterised 24 previously not described canine and 4 human RAGE splicing variants, analysed their structure, classified their characteristics, and derived their respective protein forms. Interestingly, the healthy and the neoplastic tissue samples showed in majority RAGE transcripts coding for the complete receptor and transcripts showing insertions of intron 1.

  8. Receptor for Advanced Glycation End Products (RAGE) as a Novel Target for Inhibiting Breast Cancer Bone Metastasis

    Science.gov (United States)

    2013-04-01

    Fellowship from Comprehensive Cancer Center, The Ohio State University. Authors thank Dr. Zahida Qamri, Dr. Nandu Thodi and Mohamed Adel for their help in in...depleted in mice using clodrolip (21). Therefore, we treated MVT-1 tumor– bearing mice with intra- peritoneal inoculations of clodrolip or with an empty

  9. Chemical Constituents of Smilax china L. Stems and Their Inhibitory Activities against Glycation, Aldose Reductase, α-Glucosidase, and Lipase.

    Science.gov (United States)

    Lee, Hee Eun; Kim, Jin Ah; Whang, Wan Kyunn

    2017-03-11

    The search for natural inhibitors with anti-diabetes properties has gained increasing attention. Among four selected Smilacaceae family plants, Smilax china L. stems (SCS) showed significant in vitro anti-glycation and rat lens aldose reductase inhibitory activities. Bioactivity-guided isolation was performed with SCS and four solvent fractions were obtained, which in turn yielded 10 compounds, including one phenolic acid, three chlorogenic acids, four flavonoids, one stilbene, and one phenylpropanoid glycoside; their structures were elucidated using nuclear magnetic resonance and mass spectrometry. All solvent fractions, isolated compounds, and stem extracts from plants sourced from six different provinces of South Korea were next tested for their inhibitory effects against advanced glycation end products, as well as aldose reductase. α-Glucosidase, and lipase assays were also performed on the fractions and compounds. Since compounds 3 , 4 , 6 , and 8 appeared to be the superior inhibitors among the tested compounds, a comparative study was performed via high-performance liquid chromatography with photodiode array detection using a self-developed analysis method to confirm the relationship between the quantity and bioactivity of the compounds in each extract. The findings of this study demonstrate the potent therapeutic efficacy of SCS and its potential use as a cost-effective natural alternative medicine against type 2 diabetes and its complications.

  10. Chemical Constituents of Smilax china L. Stems and Their Inhibitory Activities against Glycation, Aldose Reductase, α-Glucosidase, and Lipase

    Directory of Open Access Journals (Sweden)

    Hee Eun Lee

    2017-03-01

    Full Text Available The search for natural inhibitors with anti-diabetes properties has gained increasing attention. Among four selected Smilacaceae family plants, Smilax china L. stems (SCS showed significant in vitro anti-glycation and rat lens aldose reductase inhibitory activities. Bioactivity-guided isolation was performed with SCS and four solvent fractions were obtained, which in turn yielded 10 compounds, including one phenolic acid, three chlorogenic acids, four flavonoids, one stilbene, and one phenylpropanoid glycoside; their structures were elucidated using nuclear magnetic resonance and mass spectrometry. All solvent fractions, isolated compounds, and stem extracts from plants sourced from six different provinces of South Korea were next tested for their inhibitory effects against advanced glycation end products, as well as aldose reductase. α-Glucosidase, and lipase assays were also performed on the fractions and compounds. Since compounds 3, 4, 6, and 8 appeared to be the superior inhibitors among the tested compounds, a comparative study was performed via high-performance liquid chromatography with photodiode array detection using a self-developed analysis method to confirm the relationship between the quantity and bioactivity of the compounds in each extract. The findings of this study demonstrate the potent therapeutic efficacy of SCS and its potential use as a cost-effective natural alternative medicine against type 2 diabetes and its complications.

  11. Inability of Turbidimetry Method in Detecting Glycated Hemoglobin to Select Diabetes Mellitus Patients According to Their Concentrations of Blood Glucose Levels.

    Science.gov (United States)

    Abdallah, Alessandra M; Alves, Beatriz C A; Gehrke, Flávia S; Sant' Ana, Aleksandra V L; Azzalis, Ligia A; Junqueira, Virginia B C; Adami, Fernando; Pereira, Edimar C; Fonseca, Fernando L A

    2015-07-01

    Diabetes mellitus is a chronicle illness in which there is a high blood glucose level defined as hyperglycemia, resulted by a deficiency in insulin secretion and/or in its action. Nowadays, it is being seen as a public health problem and is reaching increasing proportions with regard to the appearance of new cases. For diagnosis, sensible and accurate methods should be used to avoid complications of the sickness. The measure of glycated hemoglobin may not be used for diagnosis, but is the reference method to evaluate the grade of glycemic control in the long term, reflecting the blood glucose level in the latest 2-3 months. The aim of this study was to evaluate the grade of concordance between turbidimetry and liquid chromatography methods in the glycated hemoglobin determination and to estimate the sensibility and specificity values of turbidimetry. This study included 133 blood samples obtained from patients and healthy donors, ageing between 18 and 80 years with glycemic values between 58 and 473 mg/dl. Turbidimetry is a useful method for determining glycemic levels above 100 and over 200 mg/dl, but does not have the ability to select samples with intermediary blood glucose concentrations. © 2014 Wiley Periodicals, Inc.

  12. Dietary advanced glycation endproducts

    DEFF Research Database (Denmark)

    Poulsen, Malene Wibe

    on postprandial subjective appetite sensations, appetite hormones, and markers of inflammation of two cooking methods that respectively induce or limit AGE formation were investigated in healthy overweight individuals. It was concluded that the meals affected subjective appetite sensations similarly, but the high...... sensitivity of cooking methods that induce or limit AGE formation were investigated in healthy overweight women. It was concluded that insulin sensitivity was improved with use of low heat cooking methods, compared with high heat cooking methods. In a rat study, effects on expression of AGE receptors, insulin......High heat cooking induces flavor, aroma, and color of food, but leads to formation of advanced glycation endproducts (AGEs) by the Maillard reaction. In addition to the formation in food, AGEs are also formed in vivo, and increased endogenous formation of AGEs has been linked to diabetic...

  13. Glycation & the RAGE axis: targeting signal transduction through DIAPH1.

    Science.gov (United States)

    Shekhtman, Alexander; Ramasamy, Ravichandran; Schmidt, Ann Marie

    2017-02-01

    The consequences of chronic disease are vast and unremitting; hence, understanding the pathogenic mechanisms mediating such disorders holds promise to identify therapeutics and diminish the consequences. The ligands of the receptor for advanced glycation end products (RAGE) accumulate in chronic diseases, particularly those characterized by inflammation and metabolic dysfunction. Although first discovered and reported as a receptor for advanced glycation end products (AGEs), the expansion of the repertoire of RAGE ligands implicates the receptor in diverse milieus, such as autoimmunity, chronic inflammation, obesity, diabetes, and neurodegeneration. Areas covered: This review summarizes current knowledge regarding the ligand families of RAGE and data from human subjects and animal models on the role of the RAGE axis in chronic diseases. The recent discovery that the cytoplasmic domain of RAGE binds to the formin homology 1 (FH1) domain, DIAPH1, and that this interaction is essential for RAGE ligand-stimulated signal transduction, is discussed. Finally, we review therapeutic opportunities targeting the RAGE axis as a means to mitigate chronic diseases. Expert commentary: With the aging of the population and the epidemic of cardiometabolic disease, therapeutic strategies to target molecular pathways that contribute to the sequelae of these chronic diseases are urgently needed. In this review, we propose that the ligand/RAGE axis and its signaling nexus is a key factor in the pathogenesis of chronic disease and that therapeutic interruption of this pathway may improve quality and duration of life.

  14. Protective effect of Withania somnifera (Solanaceae) on collagen glycation and cross-linking.

    Science.gov (United States)

    Babu, Pon Velayutham Anandh; Gokulakrishnan, Adikesavan; Dhandayuthabani, Rajendra; Ameethkhan, Dowlath; Kumar, Chandrasekara Vimal Pradeep; Ahamed, Md Iqbal Niyas

    2007-06-01

    Modification of collagen such as non-enzymatic glycation and cross-linking plays an important role in diabetic complications and age-related diseases. We evaluate the effect of Withania somnifera on glucose-mediated collagen glycation and cross-linking in vitro. Extent of glycation, viscosity, collagen-linked fluorescence and pepsin solubility were assessed in different experimental procedures to investigate the effect of W. somnifera. Tail tendons obtained from rats (Rattus norvegicus) weighing 250-275 g were incubated with 50 mM glucose and 100 mg of metformin or Withania root powder or ethanolic extract of Withania under physiological conditions of temperature and pH for 30 days. Formation of advanced glycation end products (AGE) was measured by fluorescent method whereas the cross-linking of collagen was assessed by pepsin digestion and viscosity measurements. Tendon collagen incubated with glucose showed an increase in glycation, AGE and cross-linking of collagen. The collagen incubated with W. somnifera and metformin ameliorates these modifications. The ethanolic extract of Withania showed more prominent effect than Withania root powder. The activity of ethanolic extract of Withania is comparable to metformin, a known antiglycating agent. In conclusion, Withania could have therapeutic role in the prevention of glycation induced pathogenesis in diabetes mellitus and aging.

  15. Spectroscopic studies on native proteins, glycated and inhibited nonenzymatically

    International Nuclear Information System (INIS)

    Gil, H; Otero, V; Contreras, S

    1995-01-01

    The nonenzymatic glucation is an irreversible process whose speed depends on the concentration reducer sugar in plasma. The glycated albumins is higher in diabetic people. Up to now, this has been indicated as an important mechanism in the pathology of the the secondary complications associated with diabetes and the normal aging. Recently a lot of interest has been focused on the search of certain compounds (inhibitors) to prevent the glucation and / or the formation of ending products of advanced glucation, AGE. The reaction of glucose with the human albumin and γ globulins and the effects of acid acetylsalicylic and ascorbic acid were studied. The proteins were incubated with glucose in absence and in presence of inhibitors for one month. The solutions were dialysed and then lyophilizated. The absorption spectra were taken for native proteins, glycated and inhibited (2 mg/ml) in phosphate 10 mM buffer, p H 7.3. It is observed that the spectra of the acetylate proteins and native proteins are practically same. This can be interpreted as an inhibitor effect of acid acetylsalicylic on glucation. In all the observed cases the glycated proteins absorb more than the native ones and they present a line toward the visible region. The ascorbic acid absorbs below the native proteins and it doesn't present the same characteristics. The increase and / or the decrease in the absorption picks can be associated with environmental changes affecting the groups involved in the absorption process [es

  16. Targeted reduction of advanced glycation improves renal function in obesity.

    Science.gov (United States)

    Harcourt, Brooke E; Sourris, Karly C; Coughlan, Melinda T; Walker, Karen Z; Dougherty, Sonia L; Andrikopoulos, Sofianos; Morley, Amy L; Thallas-Bonke, Vicki; Chand, Vibhasha; Penfold, Sally A; de Courten, Maximilian P J; Thomas, Merlin C; Kingwell, Bronwyn A; Bierhaus, Angelika; Cooper, Mark E; de Courten, Barbora; Forbes, Josephine M

    2011-07-01

    Obesity is highly prevalent in Western populations and is considered a risk factor for the development of renal impairment. Interventions that reduce the tissue burden of advanced glycation end-products (AGEs) have shown promise in stemming the progression of chronic disease. Here we tested if treatments that lower tissue AGE burden in patients and mice would improve obesity-related renal dysfunction. Overweight and obese individuals (body mass index (BMI) 26-39 kg/m(2)) were recruited to a randomized, crossover clinical trial involving 2 weeks each on a low- and a high-AGE-containing diet. Renal function and an inflammatory profile (monocyte chemoattractant protein-1 (MCP-1) and macrophage migration inhibitory factor (MIF)) were improved following the low-AGE diet. Mechanisms of advanced glycation-related renal damage were investigated in a mouse model of obesity using the AGE-lowering pharmaceutical, alagebrium, and mice in which the receptor for AGE (RAGE) was deleted. Obesity, resulting from a diet high in both fat and AGE, caused renal impairment; however, treatment of the RAGE knockout mice with alagebrium improved urinary albumin excretion, creatinine clearance, the inflammatory profile, and renal oxidative stress. Alagebrium treatment, however, resulted in decreased weight gain and improved glycemic control compared with wild-type mice on a high-fat Western diet. Thus, targeted reduction of the advanced glycation pathway improved renal function in obesity.

  17. A Perspective on the Maillard Reaction and the Analysis of Protein Glycation by Mass Spectrometry: Probing the Pathogenesis of Chronic Disease

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qibin; Ames, Jennifer M.; Smith, Richard D.; Baynes, John; Metz, Thomas O.

    2008-12-18

    The Maillard reaction, starting from the glycation of protein and progressing to the formation of advanced glycation end-products (AGEs), is implicated in the development of complications of diabetes mellitus, as well as in the pathogenesis of cardiovascular, renal, and neurodegenerative diseases. In this perspective review, we provide on overview on the relevance of the Maillard reaction in the pathogenesis of chronic disease and discuss traditional approaches and recent developments in the analysis of glycated proteins by mass spectrometry. We propose that proteomics approaches, particularly bottom-up proteomics, will play a significant role in analyses of clinical samples leading to the identification of new markers of disease development and progression.

  18. In vivo and in vitro identification of Z-BOX C - a new bilirubin oxidation end product.

    Science.gov (United States)

    Ritter, Marcel; Neupane, Sandesh; Seidel, Raphael A; Steinbeck, Christoph; Pohnert, Georg

    2018-03-13

    A new bilirubin oxidation end product (BOX) was isolated and characterized. The formation of the so-called Z-BOX C proceeds from bilirubin via propentdyopents as intermediates. This BOX was detected in pathological human bile samples using liquid chromatography/mass spectrometry and has potential relevance for liver dysfunction and cerebral vasospasms.

  19. Microglial cell death induced by glycated bovine serum albumin: nitric oxide involvement.

    Science.gov (United States)

    Khazaei, Mohammad R; Habibi-Rezaei, Mehran; Karimzadeh, Fereshteh; Moosavi-Movahedi, Ali Akbar; Sarrafnejhad, Abdo Alfattah; Sabouni, Farzaneh; Bakhti, Mostafa

    2008-08-01

    Nonenzymatic glycation results in the formation of advanced glycation end products (AGEs) through a nonenzymatic multistep reaction of reducing sugars with proteins. AGEs have been suspected to be involved in the pathogenesis of several chronic clinical neurodegenerative complications including Alzheimer's disease, which is characterized with the activation of microglial cells in neuritic plaques. To find out the consequence of this activation on microglial cells, we treated the cultured microglial cells with different glycation levels of Bovine Serum Albumin (BSA) which were prepared in vitro. Extent of glycation of protein has been characterized during 16 weeks of incubation with glucose. Treatment of microglial cells with various levels of glycated albumin induced nitric oxide (NO) production and consequently cell death. We also tried to find out the mode of death in AGE-activated microglial cells. Altogether, our results suggest that AGE treatment causes microglia to undergo NO-mediated apoptotic and necrotic cell death in short term and long term, respectively. NO production is a consequence of iNOS expression in a JNK dependent RAGE signalling after activation of RAGE by AGE-BSA.

  20. Anti-glycated and antiradical activities in vitro of polysaccharides from Ganoderma capense.

    Science.gov (United States)

    Yan, Chunyan; Kong, Fansheng; Zhang, Dezhi; Cui, Jiangxia

    2013-01-01

    Ganoderma capense is a Ganoderma species and is widely used, especially in Asia, as a well-known medicinal mushroom for health-promoting effect and for treatment of chronic diseases, such as diabetes, aging, etc. G. capense is rich of polysaccharide. To isolate the polysaccharides from G. capense and evaluate their anti-glycated and antiradical activities in vitro. The dried powder of submerged fermentation culturing mycelium of G. capense was defatted, extracted with water/alkaline water followed by ethanol precipitation and deproteinated. And four crude polysaccharides, named as GC50, GC70, GC90 and GCB, were obtained. For the first time, the in vitro anti-glycated activities of the four samples were studied by non-enzymatic glycation reaction. Then, the DPPH radical and hydroxyl radical assays were established to estimate the antiradical capacity of the four samples. Meanwhile the contents of polysaccharides were determined by phenol-sulphuric acid colorimetry. Preliminary antiradical in vitro studies indicated that the four crude polysaccharides showed concentration-dependent scavenging abilities on DPPH and hydroxyl radicals. The evaluation of anti-glycation activity suggested that GC70 had good potential for inhibiting the formation of advanced glycation end products. Time- and dose-dependent effects were also observed for all GC70 samples.

  1. Effect of germanium-132 on galactose cataracts and glycation in rats.

    Science.gov (United States)

    Unakar, N J; Johnson, M; Tsui, J; Cherian, M; Abraham, E C

    1995-08-01

    Germanium compounds have been shown to be effective in preventing the formation of advanced glycation end-products and for reversible solubilization of glycated proteins. As protein glycation has been proposed to play a role in lens opacification, we initiated studies to evaluate the effects of 2-carboxyethyl germanium sesquioxide (germanium compound 132 or Ge-132) on galactose-induced cataractogenesis. For this study young Sprague-Dawley rats were fed a 50% galactose diet. One group of rats received topical saline and another group was administered Ge-132 in saline four times a day. The lenses were periodically examined with an ophthalmoscope and at desired intervals processed for light and scanning electron microscopy. Our observations, beginning at 3 days and continuing to 21 days of galactose feeding, exhibited the characteristic galactose-induced morphological alterations, which include the formation of vacuoles, cysts, membrane disruption and swelling of fibers and epithelial cells as well as disorganization of the bow in lenses of rats in both groups. However, in the majority of rats administered Ge-132 these alterations were delayed as compared to the lenses of rats administered saline. Our findings show that, although the initiation, progression and pattern of lens opacification in rats receiving saline and Ge-132 were similar, in the majority of lenses the progression and establishment of mature cataracts in the Ge-132 group of rats were delayed. Analysis of the water-soluble and water-insoluble lens-protein fractions for glycated proteins showed increased levels of the Amadori products and advanced glycation related fluorescent products in galactosemic rats treated with saline eye drops. In rats receiving the topical Ge-132 treatment the levels of these glycation products were substantially reduced to levels lower than control values. Prevention of glycation seems to be a mechanism by which cataract progression is delayed.

  2. Immunoglobulin-G Glycation by Fructose Leads to Structural Perturbations and Drop Off in Free Lysine and Arginine Residues.

    Science.gov (United States)

    Faisal, Mohammad; Alatar, Abdulrahman A; Ahmad, Saheem

    2017-01-01

    Non-enzymatic glycation is the addition of free carbonyl group of reducing sugar to the free amino groups of proteins and leads to the formation of early glycation products and further into advanced glycation end products (AGEs). Fructose reacts rapidly with the free amino groups of proteins to form AGEs. AGEs are believed to be involved in the pathogenesis of several diseases, particularly in diabetic complications. In this study, IgG was glycated with fructose monosaccharide at 10 mM concentration for varying time interval. The reaction mixture was kept at 37ºC. The early glycation of IgG was done by nitroblue tetrazolium assay (NBT), and the generation of AGEs was done by the extent of side chain modifications (lysine and arginine), Nε-carboxymethyl lysine, pentosidine and carbonyl content. The decrease in free lysine and arginine residues suggests that protein 'IgG' has undergone modification specifically on epsilon amino groups of lysine and arginine. Additionally, their fluorescence and absorbance characteristics were also systematically studied. The results suggest that the maximum Amadori product (ketoamine content) was formed on sixth day of the incubation. The conformational structural perturbation was observed within the glycated IgG protein as studied by using various physicochemical techniques. This study reports structural perturbation, formation of various intermediates and AGEs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. The role of glycation in the pathogenesis of aging and its prevention through herbal products and physical exercise.

    Science.gov (United States)

    Kim, Chan-Sik; Park, Sok; Kim, Junghyun

    2017-09-30

    Advanced glycation end products (AGEs) are non-enzymatic modifications of proteins or lipids after exposure to sugars. In this review, the glycation process and AGEs are introduced, and the harmful effects of AGEs in the aging process are discussed. Results from human and animal studies examining the mechanisms and effects of AGEs are considered. In addition, publications addressing means to attenuate glycation stress through AGE inhibitors or physical exercise are reviewed. AGEs form in hyperglycemic conditions and/or the natural process of aging. Numerous publications have demonstrated acceleration of the aging process by AGEs. Exogenous AGEs in dietary foods also trigger organ dysfunction and tissue aging. Various herbal supplements or regular physical exercise have beneficial effects on glycemic control and oxidative stress with a consequent reduction of AGE accumulation during aging. The inhibition of AGE formation and accumulation in tissues can lead to an increase in lifespan. ©2017 The Korean Society for Exercise Nutrition

  4. Inhibitory effect of gold nanoparticles on the D-ribose glycation of bovine serum albumin

    Directory of Open Access Journals (Sweden)

    Liu W

    2014-11-01

    Full Text Available Weixi Liu,1 Menashi A Cohenford,1–3 Leslie Frost,3 Champika Seneviratne,4 Joel A Dain1 1Department of Chemistry, University of Rhode Island, Kingston, RI, USA; 2Department of Integrated Science and Technology, 3Department of Chemistry, Marshall University, Huntington, WV, USA; 4Department of Chemistry, College of the North Atlantic, Labrador, NL, Canada Abstract: Formation of advanced glycation end products (AGEs by nonenzymatic glycation of proteins is a major contributory factor to the pathophysiology of diabetic conditions including senile dementia and atherosclerosis. This study describes the inhibitory effect of gold nanoparticles (GNPs on the D-ribose glycation of bovine serum albumin (BSA. A combination of analytical methods including ultraviolet–visible spectrometry, high performance liquid chromatography, circular dichroism, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF mass spectrometry were used to determine the extent of BSA glycation in the presence of citrate reduced spherical GNPs of various sizes and concentrations. GNPs of particle diameters ranging from 2 nm to 20 nm inhibited BSA’s AGE formation. The extent of inhibition correlated with the total surface area of the nanoparticles. GNPs of highest total surface area yielded the most inhibition whereas those with the lowest total surface area inhibited the formation of AGEs the least. Additionally, when GNPs’ total surface areas were set the same, their antiglycation activities were similar. This inhibitory effect of GNPs on BSA’s glycation by D-ribose suggests that colloidal particles may have a therapeutic application for the treatment of diabetes and conditions that promote hyperglycemia. Keywords: gold nanoparticles, glycation, AGEs, GNPs, BSA

  5. Monitoring the progress of non-enzymatic glycation in vitro

    International Nuclear Information System (INIS)

    Shaw, S.M.; Crabbe, M.J.

    1994-01-01

    The progress of in vitro non-enzymatic glycation of bovine serum albumin was followed by using 14 C-glucose and a nitroblue tetrazolium assay, absorption and fluorescence spectroscopy, SDS gel electrophoresis and protease digestion. The number of adducts detectable using both 14 C-tracers and a fructosamine assay remained low at physiological glucose concentrations, fewer than five adducts being detectable. When glucose concentrations > 1.0 M were used the number of adducts was found to greatly exceed the number of lysyl residues available in BSA, indicative of cross-linking between Maillard products. Incubation of BSA with glucose concentrations of up to 160 mM for one month produced no observable increase in molecular weight by SDS gel electrophoresis, showing that at physiological glucose concentrations, increases in molecular weight were minimal for short incubation periods. Increases in absorption were proportial to both the glucose concentration and the incubation time. Several absorption peaks, at 370, 488 and 554 nm, were consistent in appearance throughout the course of each incubation. Fluorescence spectroscopy of the modified proteins showed a disappearance of the fluorescence associated with peptide bonds and aromatic residues and the appearance of a broad peak at longer wavelengths due to the wide range of absorptive/fluorescent wavelengths of the developing Maillard products. Protease digestion gave similar patterns with non-glycated and glycated protein, suggesting that glycation did not block digestion sites, and that partial digestion did not cause significant further exposure of susceptible sites. Our results show that while glycation ultimately results in protein conformational changes and the formation of large molecular weight species, these occur at a relatively late stage in the maturation of protein Maillard products, after ≥ nine months of incubation with glucose concentration of ≥ 20 mM. Monitoring of AGE maturation in vitro is better

  6. Glycation of human high density lipoprotein by methylglyoxal: effect on HDL-paraoxonase activity.

    Science.gov (United States)

    Bacchetti, Tiziana; Masciangelo, Simona; Armeni, Tatiana; Bicchiega, Virginia; Ferretti, Gianna

    2014-03-01

    Methylglyoxal (MG), a reactive carbonyl compound formed primarily from triose phosphates, appears to be involved in the molecular mechanisms of diabetes, end-stage renal disease and neurodegenerative diseases. Methylglyoxal exerts several biological activities. Among these it promotes advanced glycation end products (AGEs), which are crucial in pathogenesis of human disease. Previous studies have demonstrated that MG reacts with proteins and compositional modifications reflect loss of biological activity. The aim of the study was to investigate the effect of in vitro MG-induced glycation on human high density lipoprotein (HDL) and on the activity of the enzyme paraoxonase-1 (PON1). HDL was incubated in the absence or in the presence of MG (0.2mmol/L and 1.0mmol/L) (MG-HDL) for different times (3, 6, 24h) at 37° C. We evaluated apoprotein compositional changes, in both control and MG treated HDL, using intrinsic fluorescence of tryptophan and monitoring the decrease of free amino groups. Furthermore we evaluated fluorescent advanced glycation end products (Ex=370nm, Em=440nm) and the activity of HDL-paraoxonase. We demonstrated that human HDL is susceptible to glycation by MG (0.2mmol/L and 1mmol/L). The decrease of free amino groups and of intrinsic fluorescence of tryptophan demonstrates HDL apoprotein modifications in HDL incubated with MG. The compositional changes are associated with a significant increase in fluorescent advanced glycation end products and with a significant decrease of paraoxonase-1 enzyme activity associated with the HDL surface. HDL-associated paraoxonase is responsible for the anti-inflammatory and anti-oxidative properties of HDL and detoxification against homocysteine-thiolactone. Therefore, modifications of apoprotein composition and the decrease of paraoxonase-1 activity in MG-treated HDL could affect the protective effect exerted by HDL against oxidative damage and could contribute to complications in patients affected by diseases

  7. Protein and low molecular mass thiols as targets and inhibitors of glycation reactions.

    Science.gov (United States)

    Zeng, Jingmin; Davies, Michael J

    2006-12-01

    Protein glycation has been implicated in the aging process as well as the complications of diabetes (retinopathy, neuropathy, nephropathy, and atherosclerosis). The nitrogen substituents of Lys, Arg, and His residues and the N-terminus of proteins are known to be readily glycated. As the thiol group of Cys is a powerful nucleophile, we hypothesized that Cys residues should also be targets of glycation and that low molecular mass thiols may act as protective agents. In this study the role of thiol glycation, induced by dicarbonyls, in protein cross-link formation and damage prevention is examined. It is shown that incubation of creatine kinase with glyoxal results in protein cross-link formation, with this occurring concurrently with loss of thiol groups, enzyme inactivation, and formation of S-carboxymethylcysteine, a product of glyoxal adduction to Cys residues. Cross-links have also been detected between N-acetylcysteine and the Lys-rich protein histone H1, demonstrating the formation of thiol-glyoxal-amine cross-links. Mass spectrometry has been used to characterize some of these cross-links as 2-(alkylthio)acetamides. A range of low molecular mass thiols have been shown to inhibit dicarbonyl adduction to, and cross-linking of, the thiol-free protein lysozyme, consistent with these thiols being alternative (sacrificial) targets of glycation. Some of these thiols are more efficient modulators of glycation than established glycation inhibitors such as aminoguanidine. These data demonstrate that thiols are facile targets of glycation and that low molecular mass thiols are potent glycation inhibitors. These data may aid the design of therapeutic agents for the treatment of the complications of diabetes.

  8. Open tubular capillary electrochromatography: A useful microreactor for collagen I glycation and interaction studies with low-density lipoprotein particles

    Energy Technology Data Exchange (ETDEWEB)

    D' Ulivo, Lucia; Witos, Joanna [Laboratory of Analytical Chemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki (Finland); Ooerni, Katariina; Kovanen, Petri T. [Wihuri Research Institute, Kalliolinnantie 4, FIN-00140, Helsinki (Finland); Riekkola, Marja-Liisa, E-mail: marja-liisa.riekkola@helsinki.fi [Laboratory of Analytical Chemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki (Finland)

    2010-04-07

    Diabetes, a multifunctional disease and a major cause of morbidity and mortality in the industrialized countries, strongly associates with the development and progression of atherosclerosis. One of the consequences of high level of glucose in the blood circulation is glycation of long-lived proteins, such as collagen I, the most abundant component of the extracellular matrix (ECM) in the arterial wall. Glycation is a long-lasting process that involves the reaction between a carbonyl group of the sugar and an amino group of the protein, usually a lysine residue. This reaction generates an Amadori product that may evolve in advanced glycation end products (AGEs). AGEs, as reactive molecules, can provoke cross-linking of collagen I fibrils. Since binding of low-density lipoproteins (LDLs) to the ECM of the inner layer of the arterial wall, the intima, has been implicated to be involved in the onset of the development of an atherosclerotic plaque, collagen modifications, which can affect the affinity of native and oxidized LDL for collagen I, can promote the entrapment of LDLs in the intima and accelerate the progression of atherosclerosis. In this study, open tubular capillary electrochromatography is proposed as a new microreactor to study in situ glycation of collagen I. The kinetics of glycation was first investigated in a fused silica collagen I-coated capillary. Dimethyl sulphoxide, injected as an electroosmotic flow marker, gave information about the charge of coating. Native and oxidized LDL, and selected peptide fragments from apolipoprotein B-100, the protein covering LDL particles, were injected as marker compounds to clarify the interactions between LDLs and the glycated collagen I coating. The method proposed is simple and inexpensive, since only small amounts of collagen and LDL are required. Atomic force microscopy images complemented our studies, highlighting the difference between unmodified and glycated collagen I surfaces.

  9. The Course of Skin and Serum Biomarkers of Advanced Glycation Endproducts and Its Association with Oxidative Stress, Inflammation, Disease Severity, and Mortality during ICU Admission in Critically Ill Patients : Results from a Prospective Pilot Study

    NARCIS (Netherlands)

    Meertens, John H.; Nienhuis, Hans L; Lefrandt, Joop D; Schalkwijk, Casper G; Nyyssönen, Kristiina; Ligtenberg, Jack J M; Smit, Andries J; Zijlstra, Jan G; Mulder, Douwe J.

    2016-01-01

    Background Advanced glycation end products (AGEs) have been implicated in multiple organ failure, predominantly via their cellular receptor (RAGE) in preclinical studies. Little is known about the time course and prognostic relevance of AGEs in critically ill human patients, including those with

  10. Glycation and carboxymethyllysine levels in skin collagen predict the risk of future 10-year progression of diabetic retinopathy and nephropathy in the diabetes control and complications trial and epidemiology of diabetes interventions and complications participants with type 1 diabetes.

    Science.gov (United States)

    Genuth, Saul; Sun, Wanjie; Cleary, Patricia; Sell, David R; Dahms, William; Malone, John; Sivitz, William; Monnier, Vincent M

    2005-11-01

    Several mechanistic pathways linking hyperglycemia to diabetes complications, including glycation of proteins and formation of advanced glycation end products (AGEs), have been proposed. We investigated the hypothesis that skin collagen glycation and AGEs predict the risk of progression of microvascular disease. We measured glycation products in the skin collagen of 211 Diabetes Control and Complications Trial (DCCT) volunteers in 1992 who continued to be followed in the Epidemiology of Diabetes Interventions and Complications study for 10 years. We determined whether the earlier measurements of glycated collagen and AGE levels correlated with the risk of progression of retinopathy and nephropathy from the end of the DCCT to 10 years later. In multivariate analyses, the combination of furosine (glycated collagen) and carboxymethyllysine (CML) predicted the progression of retinopathy (chi2 = 59.4, P retinopathy) and (chi2 = 12.8, P = 0.0016 for nephropathy). The predictive effect of A1C vanished after adjustment for furosine and CML (chi2 = 0.0002, P = 0.987 for retinopathy and chi2 = 0.0002, P = 0.964 for nephropathy). Furosine explained more of the variation in the 10-year progression of retinopathy and nephropathy than did CML. These results strengthen the role of glycation of proteins and AGE formation in the pathogenesis of retinopathy and nephropathy. Glycation and subsequent AGE formation may explain the risk of these complications associated with prior A1C and provide a rational basis for the phenomenon of "metabolic memory" in the pathogenesis of these diabetes complications.

  11. Biological variability of glycated hemoglobin.

    Science.gov (United States)

    Braga, Federica; Dolci, Alberto; Mosca, Andrea; Panteghini, Mauro

    2010-11-11

    The measurement of glycated hemoglobin (HbA(1c)) has a pivotal role in monitoring glycemic state in diabetic patients. Furthermore, the American Diabetes Association has recently recommended the use of HbA(1c) for diabetes diagnosis, but a clear definition of the clinically allowable measurement error is still lacking. Information on biological variability of the analyte can be used to achieve this goal. We systematically reviewed the published studies on the biological variation of HbA(1c) to check consistency of available data in order to accurately define analytical goals. The nine recruited studies were limited by choice of analytic methodology, population selection, protocol application and statistical analyses. There is an urgent need to determine biological variability of HbA(1c) using a specific and traceable assay, appropriate protocol and appropriate statistical evaluation of data. 2010 Elsevier B.V. All rights reserved.

  12. Characteristics of glycation and glycation sites of lysozyme by matrix-assisted laser desorption/ionization time of flight/time-of-flight mass spectrometry and Liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Ruan, Eric Dongliang; Wang, Hui; Ruan, Yuanyuan; Juáreza, Manuel

    2014-01-01

    Protein glycation with reducing sugars through the Maillard reaction is regarded as one of the most important reactions in food chem- istry. Amadori rearrangement products [ARPs] are produced at the initial stage of the Maillard reaction and then advanced glycation products may be formed. We report here that using matrix-assisted laser desorption/ionization mass spectrometry with time-of-flight detection [MALDI-TOF-MS] and electrospray ionization mass spectrometry (ESI-MSJ to monitor the glycation process in lysozyme and the D-glucose model system. MALDI-TOF-MS displayed a heterogeneous distribution of glycation via a total mass shift in spectra. However electrospray ionization mass spectrometry [ESI-MS] data showed that a total of four molecules of glucose reacted with Lysozyme at an increase in molecular weight by a 162 Da unit. Further, we identified the glycation sites of lysozyme by using MALDI-TOF/TOF-MS and Liquid chromatography [LC]-ESI-MS/MS. Besides the two glycation sites of Lys1 and Lys97 identified by MALDI-TOF/TOF-MS, the other two glycation sites of Lys13 and Lys116 were characterized unambiguously by LC-ESI-MS/MS. Both MALDI-TOF/TOF-MS and LC-ESI-MS/ MS provided confidence in the study of the glycation by restricting the number of possible residues through (un]modified ions. The study is useful to monitor and characterize glycation in protein systems based on both MALDI-TOF-MS and ESI-MS. Comparatively, LC-ESI-MS/MS provides more fragments with better recovery for the identification of glycation than MALDI-TOF/TOF-MS.

  13. Comprehensive Identification of Glycated Peptides and Their Glycation Motifs in Plasma and Erythrocytes of Control and Diabetic Subjects

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qibin; Monroe, Matthew E.; Schepmoes, Athena A.; Clauss, Therese RW; Gritsenko, Marina A.; Meng, Da; Petyuk, Vladislav A.; Smith, Richard D.; Metz, Thomas O.

    2011-07-01

    Non-enzymatic glycation of proteins is implicated in diabetes mellitus and its related complications. In this report, we extend our previous development and refinement of proteomics-based methods for the analysis of non-enzymatically glycated proteins to comprehensively identify glycated proteins in normal and diabetic human plasma and erythrocytes. Using immunodepletion, enrichment, and fractionation strategies, we identified 7749 unique glycated peptides, corresponding to 3742 unique glycated proteins. Semi-quantitative comparisons revealed a number of proteins with glycation levels significantly increased in diabetes relative to control samples and that erythrocyte proteins are more extensively glycated than plasma proteins. A glycation motif analysis revealed amino acids that are favored more than others in the protein primary structures in the vicinity of the glycation sites in both sample types. The glycated peptides and corresponding proteins reported here provide a foundation for the potential identification of novel markers for diabetes, glycemia, or diabetic complications.

  14. Glycation and glycoxidation of low-density lipoproteins by glucose and low-molecular mass aldehydes. Formation of modified and oxidized particles

    DEFF Research Database (Denmark)

    Knott, Heather M; Brown, Bronwyn E; Davies, Michael Jonathan

    2003-01-01

    Patients with diabetes mellitus suffer from an increased incidence of complications including cardiovascular disease and cataracts; the mechanisms responsible for this are not fully understood. One characteristic of such complications is an accumulation of advanced glycation end-products formed...... or direct oxidation of lipid or proteins) only occur to any significant extent at later time points. This 'carbonyl-stress' may facilitate the formation of foam cells and the vascular complications of diabetes....

  15. The Circulating Level of Soluble Receptor for Advanced Glycation End Products Displays Different Patterns in Ulcerative Colitis and Crohn's Disease: A Cross-Sectional Study.

    Science.gov (United States)

    Ciccocioppo, Rachele; Imbesi, Venerina; Betti, Elena; Boccaccio, Vincenzo; Kruzliak, Peter; Gallia, Alessandra; Cangemi, Giuseppina Cristina; Maffe, Gabriella Carnevale; Vanoli, Alessandro; Merante, Serena; De Amici, Mara; Falcone, Colomba; Klersy, Catherine; Corazza, Gino Roberto

    2015-08-01

    RAGE is a transmembrane receptor expressed on immune and endothelial cells, whose binding with its ligands, the S100 calgranulins, leads to chronic inflammation. Conversely, its soluble form (sRAGE) plays a protective role by acting as a decoy. We carried out a cross-sectional analysis of the sRAGE and S100A12 serum levels in patients with Crohn's disease (CD) and ulcerative colitis (UC) and searched for a correlation with clinical and biological markers of activity. We enrolled 60 CD, 67 UC patients, and 66 controls (all adults). Disease activity was scored through the clinical, endoscopic, and histologic indexes of severity, whilst disease location and behaviour were assessed according to the Montreal classification. In all cases, the levels of serum sRAGE, S100A12, C-reactive protein, and faecal calprotectin were measured. sRAGE levels were significantly lower in UC, both active and inactive, than in controls and CD (817.35, range 437.3-1449; 1211, range 843.7-1618; 1207.5, range 743.15-1875.75; P < 0.05 for both), and inversely correlated with clinical and endoscopic indexes of activity in both IBD groups (P < 0.05 for all) and with the histologic score in the CD group. Moreover, those CD patients with a penetrating behaviour showed a significant reduction in both sRAGE (P = 0.006) and S100A12 (P = 0.034) as compared to those with an inflammatory/stricturing pattern. Although S100A12 levels were not found up-regulated, a negative correlation appeared evident with the clinical (r = -0.38) and endoscopic (r = -0.32) indexes of activity in UC and CD, respectively. These data suggest a different role for RAGE in CD and UC, and a potential use of sRAGE as a new biomarker.

  16. Soluble and Endogenous Secretory Receptors for Advanced Glycation End Products in Threatened Preterm Labor and Preterm Premature Rupture of Fetal Membranes

    Directory of Open Access Journals (Sweden)

    Rafał Rzepka

    2015-01-01

    Full Text Available The aim of the study was to compare sRAGE and esRAGE plasma levels in pregnant women with (A threatened premature labor (n=41, (B preterm premature rupture of membranes (n=49, and (C preterm rupture of membranes at term (n=48. The relationship between these and classic intrauterine infection markers and the latent time from symptoms up to delivery depending on RAGE’s concentration were investigated. In groups A and B, a positive correlation was found between plasma sRAGE and latent time (r = 0,422; p = 0,001; r = 0,413, p = 0,004, resp.. High prognostic values were found in both groups for plasma sRAGE concentration and the latent time from symptoms up to delivery. Groups B and C presented higher levels of esRAGE than group A (526,315 ± 129,453 pg/mL and 576,212 ± 136,237 pg/mL versus 485,918 ± 133,127 pg/mL, p< 0,05. The conclusion is that sRAGE concentration can be a favorable prognostic factor in the presence of symptoms of threatened premature labor. Higher esRAGE plasma level in case of the rupture of membranes in mature and premature pregnancy suggests its participation in fetal membranes destruction.

  17. Soluble and Endogenous Secretory Receptors for Advanced Glycation End Products in Threatened Preterm Labor and Preterm Premature Rupture of Fetal Membranes

    Science.gov (United States)

    Dołegowska, Barbara; Kwiatkowski, Sebastian; Sałata, Daria; Budkowska, Marta; Domański, Leszek; Mikołajek-Bedner, Wioletta; Torbé, Andrzej

    2015-01-01

    The aim of the study was to compare sRAGE and esRAGE plasma levels in pregnant women with (A) threatened premature labor (n = 41), (B) preterm premature rupture of membranes (n = 49), and (C) preterm rupture of membranes at term (n = 48). The relationship between these and classic intrauterine infection markers and the latent time from symptoms up to delivery depending on RAGE's concentration were investigated. In groups A and B, a positive correlation was found between plasma sRAGE and latent time (r = 0,422; p = 0,001; r = 0,413, p = 0,004, resp.). High prognostic values were found in both groups for plasma sRAGE concentration and the latent time from symptoms up to delivery. Groups B and C presented higher levels of esRAGE than group A (526,315 ± 129,453 pg/mL and 576,212 ± 136,237 pg/mL versus 485,918 ± 133,127 pg/mL, ppremature labor. Higher esRAGE plasma level in case of the rupture of membranes in mature and premature pregnancy suggests its participation in fetal membranes destruction. PMID:26413536

  18. Perinatal exposure to high dietary advanced glycation end products in transgenic NOD8.3 mice leads to pancreatic beta cell dysfunction.

    Science.gov (United States)

    Borg, Danielle J; Yap, Felicia Y T; Keshvari, Sahar; Simmons, David G; Gallo, Linda A; Fotheringham, Amelia K; Zhuang, Aowen; Slattery, Robyn M; Hasnain, Sumaira Z; Coughlan, Melinda T; Kantharidis, Phillip; Forbes, Josephine M

    2018-01-02

    The contribution of environmental factors to pancreatic islet damage in type 1 diabetes remains poorly understood. In this study, we crossed mice susceptible to type 1 diabetes, where parental male (CD8 + T cells specific for IGRP 206-214 ; NOD8.3) and female (NOD/ShiLt) mice were randomized to a diet either low or high in AGE content and maintained on this diet throughout pregnancy and lactation. After weaning, NOD8.3 + female offspring were identified and maintained on the same parental feeding regimen for until day 28 of life. A low AGE diet, from conception to early postnatal life, decreased circulating AGE concentrations in the female offspring when compared to a high AGE diet. Insulin, proinsulin and glucagon secretion were greater in islets isolated from offspring in the low AGE diet group, which was akin to age matched non-diabetic C57BL/6 mice. Pancreatic islet expression of Ins2 gene was also higher in offspring from the low AGE diet group. Islet expression of glucagon, AGEs and the AGE receptor RAGE, were each reduced in low AGE fed offspring. Islet immune cell infiltration was also decreased in offspring exposed to a low AGE diet. Within pancreatic lymph nodes and spleen, the proportions of CD4 + and CD8 + T cells did not differ between groups. There were no significant changes in body weight, fasting glucose or glycemic hormones. This study demonstrates that reducing exposure to dietary AGEs throughout gestation, lactation and early postnatal life may benefit pancreatic islet secretion and immune infiltration in the type 1 diabetic susceptible mouse strain, NOD8.3.

  19. Advanced glycation end products, physico-chemical and sensory characteristics of cooked lamb loins affected by cooking method and addition of flavour precursors

    DEFF Research Database (Denmark)

    Roldan, Mar; Loebner, Jürgen; Degen, Julia

    2015-01-01

    The influence of the addition of a flavour enhancer solution (FES) (d-glucose, d-ribose, l-cysteine and thiamin) and of sous-vide cooking or roasting on moisture, cooking loss, instrumental colour, sensory characteristics and formation of Maillard reaction (MR) compounds in lamb loins was studied...... of MR products, regardless the presence of reducing sugars and the cooking method.......The influence of the addition of a flavour enhancer solution (FES) (d-glucose, d-ribose, l-cysteine and thiamin) and of sous-vide cooking or roasting on moisture, cooking loss, instrumental colour, sensory characteristics and formation of Maillard reaction (MR) compounds in lamb loins was studied....... FES reduced cooking loss and increased water content in sous-vide samples. FES and cooking method showed a marked effect on browning development, both on the meat surface and within. FES led to tougher and chewier texture in sous-vide cooked lamb, and enhanced flavour scores of sous-vide samples more...

  20. High-mobility group B1 (HMGB1) and receptor for advanced glycation end-products (RAGE) expression in canine lymphoma.

    Science.gov (United States)

    Sterenczak, Katharina A; Joetzke, Alexa E; Willenbrock, Saskia; Eberle, Nina; Lange, Sandra; Junghanss, Christian; Nolte, Ingo; Bullerdiek, Jörn; Simon, Daniela; Murua Escobar, Hugo

    2010-12-01

    Canine lymphoma is a commonly occurring, spontaneously developing neoplasia similar to human non-Hodgkin's lymphoma and, thus, is used as a valuable model for human malignancy. HMGB1 and RAGE are strongly associated with tumour progression and vascularisation. Consequently, deregulated RAGE and HMGB1 may play an important role in the mechanisms involved in lymphoma progression. Expression patterns of HMGB1 and RAGE were analysed in 22 canine lymphoma and three canine non-neoplastic control samples via real time PCR and canine beta-glucuronidase gene (GUSB) as endogenous control. HMGB1 was up-regulated in the neoplastic samples, while RAGE expression remained inconspicuous. This study demonstrated similar mechanisms in lymphoma progression in humans and dogs due to overexpression of HMGB1, which was described in human lymphomas. RAGE remained stable in terms of expression indicating that the extracellular HMGB1-induced effects are regulated by HMGB1 itself.

  1. 3-Deoxyglucosone: a potential glycating agent accountable for structural alteration in H3 histone protein through generation of different AGEs.

    Directory of Open Access Journals (Sweden)

    Jalaluddin M Ashraf

    Full Text Available Advanced glycation end-products (AGEs are heterogeneous group of compounds, known to be implicated in diabetic complications. One of the consequences of the Maillard reaction is attributed to the production of reactive intermediate products such as α-oxoaldehydes. 3-deoxyglucosone (3-DG, an α-oxoaldehyde has been found to be involved in accelerating vascular damage during diabetes. In the present study, calf thymus histone H3 was treated with 3-deoxyglucosone to investigate the generation of AGEs (Nε-carboxymethyllysine, pentosidine, by examining the degree of side chain modifications and formation of different intermediates and employing various physicochemical techniques. The results clearly indicate the formation of AGEs and structural changes upon glycation of H3 by 3-deoxyglucosone, which may hamper the normal functioning of H3 histone, that may compromise the veracity of chromatin structures and function in secondary complications of diabetes.

  2. Whole wheat bread: Effect of bran fractions on dough and end-product quality

    Science.gov (United States)

    Consumption of whole-wheat based products is encouraged due to its important nutritional elements that beneficial to human health. However, processing of whole-wheat based products, such as whole-wheat bread, results in poor end-product quality. Bran was postulated as the major problem. In this stud...

  3. 48 CFR 225.401-70 - End products subject to trade agreements.

    Science.gov (United States)

    2010-10-01

    ... products in FAR 25.003 excludes those end products that are not eligible for duty-free treatment under 19 U... Agricultural machinery and equipment 38 Construction, mining, excavating, and highway maintenance equipment 39... drying equipment (except 4470) 45 Plumbing, heating, and sanitation equipment 46 Water purification and...

  4. 48 CFR 252.225-7022 - Trade agreements certificate-inclusion of Iraqi end products.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Trade agreements... PROVISIONS AND CONTRACT CLAUSES Text of Provisions And Clauses 252.225-7022 Trade agreements certificate—inclusion of Iraqi end products. As prescribed in 225.1101(7), use the following provision: Trade Agreements...

  5. Uneven batch data alignment with application to the control of batch end-product quality.

    Science.gov (United States)

    Wan, Jian; Marjanovic, Ognjen; Lennox, Barry

    2014-03-01

    Batch processes are commonly characterized by uneven trajectories due to the existence of batch-to-batch variations. The batch end-product quality is usually measured at the end of these uneven trajectories. It is necessary to align the time differences for both the measured trajectories and the batch end-product quality in order to implement statistical process monitoring and control schemes. Apart from synchronizing trajectories with variable lengths using an indicator variable or dynamic time warping, this paper proposes a novel approach to align uneven batch data by identifying short-window PCA&PLS models at first and then applying these identified models to extend shorter trajectories and predict future batch end-product quality. Furthermore, uneven batch data can also be aligned to be a specified batch length using moving window estimation. The proposed approach and its application to the control of batch end-product quality are demonstrated with a simulated example of fed-batch fermentation for penicillin production. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Radioactivity and associated radiation hazards in ceramic raw materials and end products.

    Science.gov (United States)

    Viruthagiri, G; Rajamannan, B; Suresh Jawahar, K

    2013-12-01

    Studies have been planned to obtain activity and associated radiation hazards in ceramic raw materials (quartz, feldspar, clay, zircon, kaolin, grog, alumina bauxite, baddeleyite, masse, dolomite and red mud) and end products (ceramic brick, glazed ceramic wall and floor tiles) as the activity concentrations of uranium, thorium and potassium vary from material to material. The primordial radionuclides in ceramic raw materials and end products are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the activity level in these materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the activity concentration of (226)Ra, (232)Th and (40)K in ceramic raw materials and end products. The activity of these materials has been measured using a gamma-ray spectrometry, which contains an NaI(Tl) detector connected to multichannel analyser (MCA). Radium equivalent activity, alpha-gamma indices and radiation hazard indices associated with the natural radionuclides are calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant international legislation and guidance and compared with the results of similar studies reported in different countries. The results suggest that the use of ceramic end product samples examined in the construction of dwellings, workplace and industrial buildings is unlikely to give rise to any significant radiation exposure to the occupants.

  7. Radioactivity and associated radiation hazards in ceramic raw materials and end products

    International Nuclear Information System (INIS)

    Viruthagiri, G.; Rajamannan, B.; Suresh Jawahar, K.

    2013-01-01

    Studies have been planned to obtain activity and associated radiation hazards in ceramic raw materials (quartz, feldspar, clay, zircon, kaolin, grog, alumina bauxite, baddeleyite, masse, dolomite and red mud) and end products (ceramic brick, glazed ceramic wall and floor tiles) as the activity concentrations of uranium, thorium and potassium vary from material to material. The primordial radionuclides in ceramic raw materials and end products are one of the sources of radiation hazard in dwellings made of these materials. By the determination of the activity level in these materials, the indoor radiological hazard to human health can be assessed. This is an important precautionary measure whenever the dose rate is found to be above the recommended limits. The aim of this work was to measure the activity concentration of 226 Ra, 232 Th and 40 K in ceramic raw materials and end products. The activity of these materials has been measured using a gamma-ray spectrometry, which contains an NaI(Tl) detector connected to multichannel analyser (MCA). Radium equivalent activity, alpha-gamma indices and radiation hazard indices associated with the natural radionuclides are calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant international legislation and guidance and compared with the results of similar studies reported in different countries. The results suggest that the use of ceramic end product samples examined in the construction of dwellings, workplace and industrial buildings is unlikely to give rise to any significant radiation exposure to the occupants. (authors)

  8. Boronate-Modified Interdigitated Electrode Array for Selective Impedance-Based Sensing of Glycated Hemoglobin

    DEFF Research Database (Denmark)

    Boonyasit, Yuwadee; Laiwattanapaisal, Wanida; Chailapakul, Orawon

    2016-01-01

    An impedance-based label-free affinity sensor was developed for the recognition of glycated hemoglobin (HbA1c). Interdigitated gold microelectrode arrays (IDA) were first modified with a self-assembled monolayer of cysteamine followed by cross-linking with glutaraldehyde and subsequent binding of 3......-aminophenylboronic acid (APBA), which selectively binds HbA1c via cis-diol interactions. Impedance sensing was demonstrated to be highly responsive to the clinically relevant HbA1c levels (0.1%-8.36%) with a detection limit of 0.024% (3σ). The specificity of the assay was evaluated with non-glycated hemoglobin (Hb...

  9. Glycation inhibits trichloroacetic acid (TCA)-induced whey protein precipitation

    Science.gov (United States)

    Four different WPI saccharide conjugates were successfully prepared to test whether glycation could inhibit WPI precipitation induced by trichloroacetic acid (TCA). Conjugates molecular weights after glycation were analyzed with SDS-PAGE. No significant secondary structure change due to glycation wa...

  10. Sri Lankan black tea (Camellia sinensis L. inhibits the methylglyoxal mediated protein glycation and potentiates its reversing activity in vitro

    Directory of Open Access Journals (Sweden)

    Walimuni Kanchana Subhashini Mendis Abeysekera

    2016-02-01

    Full Text Available Objective: To evaluate inhibitory activity of methylglyoxal (MGO mediated protein glycation and ability to potentiate its reversing activity and range of antioxidant properties of Sri Lankan low grown orthodox orange pekoe grade black tea. Methods: Freeze dried black tea brew (BTB was used as the sample in this study. Antiglycation and glycation reversing activity was studied in bovine serum albumin (BSA-MGO model. Antioxidant properties were studied using total polyphenolic content, total flavonoid content, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, 1,1-diphenyl-2-picrylhydrazine and ferric reducing antioxidant power in vitro antioxidant assays. Results: The results demonstrated significant (P < 0.05 and dose dependant inhibition of BSA-MGO glycation [IC50: (164.30 ± 4.85 µg/mL], potentiating of its reversing activity [EC50: (235.39 ± 5.37 µg/mL] and marked antioxidant properties [total polyphenolic content: (119.55 ± 9.97 mg gallic acid equivalents/g BTB; total flavonoid content: (6.04 ± 1.26 mg quercetin equivalents/g BTB; 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, 1,1-diphenyl-2- picrylhydrazine and ferric reducing antioxidant power: (3.29 ± 0.06, (1.95 ± 0.15 and (1.31 ± 0.19 mmol Trolox equivalents/g BTB, respectively]. No correlations were observed between antioxidant activity and BSA-MGO glycation. Conclusions: The novel properties observed for Sri Lankan orange pekoe grade black tea indicate its usefulness as a supplementary beverage in managing MGO and advanced glycation end products related diseases and ailments.

  11. Advanced glycation endproducts influence the mRNA expression of RAGE, RANKL and various osteoblastic genes in human osteoblasts.

    Science.gov (United States)

    Franke, Sybille; Siggelkow, Heide; Wolf, Gunter; Hein, Gert

    2007-06-01

    Glycation reactions resulting in the generation and accumulation of advanced glycation endproducts (AGEs) are potential mechanisms by which bone protein may be altered in vivo. AGEs accumulate in the bone increasingly with age come into close contact with osteoblasts or osteoclasts. The direct effect of AGEs on bone cells has not been thoroughly investigated. This study aimed to examine whether glycated bovine serum albumin (AGE - BSA) as an AGE modulate the mRNA expression of various genes in primary human osteoblast cultures. The following parameters were included: RAGE (receptor for AGEs), alkaline phosphatase, osteocalcin, osterix and RANKL (receptor activator of nuclear factor-kappaB ligand). Primary human osteoblast cultures were obtained from bone specimens of six patients with osteoarthrosis. Human osteoblasts were treated in AGE - BSA or control-BSA (non-glycated BSA) containing medium (5 mg/ml each) over a time course of seven days. After RT-PCR the mRNA expression was measured by real-time PCR. Related to control - BSA exposure, the mRNA expression of RAGE, RANKL and osterix increased during AGE - BSA treament. For alkaline phosphatase and osteocalcin a tendency of down-regulation was found. In summary, the study presents evidence that advanced glycation end products accumulated in bone alter osteoblasts by activation the AGE - RAGE pathway (RAGE mRNA up-regulation), inducing enhanced osteoclastogenesis (RANKL mRNA up-regulation) and impaired matrix mineralization (down-regulation of alkaline phosphatase and osteocalcin mRNA). Thus, AGEs may play a functional role in the development of bone diseases (e.g. osteoporosis).

  12. Hazardous organic compounds in biogas plant end products-Soil burden and risk to food safety

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, K., E-mail: kimmo.suominen@evira.fi [Finnish Food Safety Authority Evira, Risk Assessment Research Unit, Mustialankatu 3, 00790 Helsinki (Finland); Verta, M. [Finnish Environmental Institute (SYKE), Mechelininkatu 34a, P.O. Box 140, 00251 Helsinki (Finland); Marttinen, S. [MTT Agrifood Research Finland, 31600 Jokioinen (Finland)

    2014-09-01

    The end products (digestate, solid fraction of the digestate, liquid fraction of the digestate) of ten biogas production lines in Finland were analyzed for ten hazardous organic compounds or compound groups: polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCB(7)), polyaromatic hydrocarbons (PAH(16)), bis-(2-ethylhexyl) phthalate (DEHP), perfluorinated alkyl compounds (PFCs), linear alkylbenzene sulfonates (LASs), nonylphenols and nonylphenol ethoxylates (NP + NPEOs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Biogas plant feedstocks were divided into six groups: municipal sewage sludge, municipal biowaste, fat, food industry by-products, animal manure and others (consisting of milling by-products (husk) and raw former foodstuffs of animal origin from the retail trade). There was no clear connection between the origin of the feedstocks of a plant and the concentrations of hazardous organic compounds in the digestate. For PCDD/Fs and for DEHP, the median soil burden of the compound after a single addition of digestate was similar to the annual atmospheric deposition of the compound or compound group in Finland or other Nordic countries. For PFCs, the median soil burden was somewhat lower than the atmospheric deposition in Finland or Sweden. For NP + NPEOs, the soil burden was somewhat higher than the atmospheric deposition in Denmark. The median soil burden of PBDEs was 400 to 1000 times higher than the PBDE air deposition in Finland or in Sweden. With PBDEs, PFCs and HBCD, the impact of the use of end products should be a focus of further research. Highly persistent compounds, such as PBDE- and PFC-compounds may accumulate in agricultural soil after repeated use of organic fertilizers containing these compounds. For other compounds included in this study, agricultural use of biogas plant end products is unlikely to cause risk to food safety in Finland. - Highlights:

  13. Hazardous organic compounds in biogas plant end products-Soil burden and risk to food safety

    International Nuclear Information System (INIS)

    Suominen, K.; Verta, M.; Marttinen, S.

    2014-01-01

    The end products (digestate, solid fraction of the digestate, liquid fraction of the digestate) of ten biogas production lines in Finland were analyzed for ten hazardous organic compounds or compound groups: polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCB(7)), polyaromatic hydrocarbons (PAH(16)), bis-(2-ethylhexyl) phthalate (DEHP), perfluorinated alkyl compounds (PFCs), linear alkylbenzene sulfonates (LASs), nonylphenols and nonylphenol ethoxylates (NP + NPEOs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Biogas plant feedstocks were divided into six groups: municipal sewage sludge, municipal biowaste, fat, food industry by-products, animal manure and others (consisting of milling by-products (husk) and raw former foodstuffs of animal origin from the retail trade). There was no clear connection between the origin of the feedstocks of a plant and the concentrations of hazardous organic compounds in the digestate. For PCDD/Fs and for DEHP, the median soil burden of the compound after a single addition of digestate was similar to the annual atmospheric deposition of the compound or compound group in Finland or other Nordic countries. For PFCs, the median soil burden was somewhat lower than the atmospheric deposition in Finland or Sweden. For NP + NPEOs, the soil burden was somewhat higher than the atmospheric deposition in Denmark. The median soil burden of PBDEs was 400 to 1000 times higher than the PBDE air deposition in Finland or in Sweden. With PBDEs, PFCs and HBCD, the impact of the use of end products should be a focus of further research. Highly persistent compounds, such as PBDE- and PFC-compounds may accumulate in agricultural soil after repeated use of organic fertilizers containing these compounds. For other compounds included in this study, agricultural use of biogas plant end products is unlikely to cause risk to food safety in Finland. - Highlights:

  14. Plasma disappearance of glycated and non-glycated albumin in type 1 (insulin-dependent) diabetes mellitus

    DEFF Research Database (Denmark)

    Bent-Hansen, L; Feldt-Rasmussen, B; Kverneland, Arne

    1993-01-01

    The fractional plasma escape rates of glycated and non-glycated albumin have earlier been measured in groups of Type 1 (insulin-dependent) diabetic patients and control subjects. The escape of non-glycated albumin was similar in control subjects and normoalbuminuric patients, but elevated in pati...... to be the glycosaminoglycans of the glomerular basal membrane and the interstitial matrix....

  15. Relationship between glycated haemoglobin and fasting plasma ...

    African Journals Online (AJOL)

    Background: Glycated haemoglobin (HbA1c) measurement provides an accurate result of glycaemic levels from blood drawn at any time of day without reference to prandial state. We established the relationship between HbA1c and fasting plasma glucose (FPG) in diabetic out-patients among diabetic outpatients in Lusaka ...

  16. Metabolic engineering of Escherichia coli for production of mixed-acid fermentation end products

    Directory of Open Access Journals (Sweden)

    Andreas Hartmut Förster

    2014-05-01

    Full Text Available Mixed-acid fermentation end products have numerous applications in biotechnology. This is probably the main driving force for the development of multiple strains that are supposed to produce individual end products with high yields. The process of engineering Escherichia coli strains for applied production of ethanol, lactate, succinate, or acetate was initiated several decades ago and is still ongoing. This review follows the path of strain development from the general characteristics of aerobic versus anaerobic metabolism over the regulatory machinery that enables the different metabolic routes. Thereafter, major improvements for broadening the substrate spectrum of Escherichia coli towards cheap carbon sources like molasses or lignocellulose are highlighted before major routes of strain development for the production of ethanol, acetate, lactate and succinate are presented.

  17. Flavan-3-ols from Ulmus davidiana var. japonica with inhibitory activity on protein glycation.

    Science.gov (United States)

    Lee, Ga Young; Jang, Dae Sik; Kim, Junghyun; Kim, Chan-Sik; Kim, Young Sook; Kim, Joo-Hwan; Kim, Jin Sook

    2008-12-01

    Four flavan-3-ols, (+)-catechin ( 1), (+)-catechin 7- O- beta- D-apiofuranoside ( 2), (+)-catechin 7- O- beta- D-xylopyranoside ( 3), (+)-catechin 7- O- beta- D-glucopyranoside ( 4), and proanthocyanidin A-1 ( 5) as well as three other constituents, isolated from an EtOAc-soluble extract of the stem barks of Ulmus davidiana var. japonica, were evaluated for inhibitory activity against the formation of AGEs. Compounds 1 - 5 exhibited a significant inhibitory activity on the formation of AGEs in an AGEs-BSA assay by specific fluorescence and this was confirmed by an indirect AGEs-ELISA. Moreover, compounds 1 and 5 markedly reduced AGEs-BSA cross-linking to collagen in a dose-dependent manner. AGEs:advanced glycation end products BSA:bovine serum albumin CC:column chromatography CD:circular dichroism.

  18. Characterization of Clostridium thermocellum strains with disrupted fermentation end-product pathways

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Veen, Douwe [ORNL; Lo, Jonathan [Dartmouth College; Brown, Steven D [ORNL; Johnson, Courtney M [ORNL; Tschaplinski, Timothy J [ORNL; Martin, Madhavi Z [ORNL; Engle, Nancy L [ORNL; Van den Berg, Robert A [Katholieke University Leuven, Belgium; Argyros, Aaron [Mascoma Corporation; Caiazza, Nicky [Mascoma Corporation; Guss, Adam M [ORNL; Lynd, Lee R [Thayer School of Engineering at Dartmouth

    2013-01-01

    Clostridium thermocellum is a thermophilic, cellulolytic anaerobe that is a candidate microorganism for industrial biofuels production. Strains with mutations in genes associated with production of L-lactate (Dldh) and/or acetate (Dpta) were characterized to gain insight into the intracellular processes that convert cellobiose to ethanol and other fermentation end-products. Cellobiose-grown cultures of the Dldh strain had identical biomass accumulation, fermentation end-products, transcription profile, and intracellular metabolite concentrations compared to its parent strain (DSM1313 Dhpt Dspo0A). The Dpta-deficient strain grew slower and had 30 % lower final biomass concentration compared to the parent strain, yet produced 75% more ethanol. A Dldh Dpta double-mutant strain evolved for faster growth had a growth rate and ethanol yield comparable to the parent strain, whereas its biomass accumulation was comparable to Dpta. Free amino acids were secreted by all examined strains, with both Dpta strains secreting higher amounts of alanine, valine, isoleucine, proline, glutamine, and threonine. Valine concentration for Dldh Dpta reached 5 mM by the end of growth, or 2.7 % of the substrate carbon utilized. These secreted amino acid concentrations correlate with increased intracellular pyruvate concentrations, up to sixfold in the Dpta and 16-fold in the Dldh Dpta strain. We hypothesize that the deletions in fermentation end-product pathways result in an intracellular redox imbalance, which the organism attempts to relieve, in part by recycling NADP* through increased production of amino acids.

  19. Characterization of Clostridium thermocellum strains with disrupted fermentation end product pathways

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Veen, Douwe [ORNL; Lo, Jonathan [Dartmouth College; Brown, Steven D [ORNL; Johnson, Courtney M [ORNL; Tschaplinski, Timothy J [ORNL; Martin, Madhavi Z [ORNL; Engle, Nancy L [ORNL; Argyros, Aaron [Mascoma Corporation; Van den Berg, Robert A [Katholieke University Leuven, Belgium; Caiazza, Nicky [Mascoma Corporation; Guss, Adam M [ORNL; Lynd, Lee R [Thayer School of Engineering at Dartmouth

    2013-01-01

    Clostridium thermocellum is a thermophilic, cellulolytic anaerobe that is a candidate microorganism for industrial biofuels production. Strains with mutations in genes associated with production of Llactate ( ldh) and/or acetate ( pta) were characterized to gain insight into the intracellular processes that convert cellobiose to ethanol and other fermentation end products. Cellobiose-grown cultures of the ldh strain had identical biomass accumulation, fermentation end products, transcription profile and intracellular metabolite concentrations compared to its parent strain (DSM1313 hpt spo0A). The pta-deficient strain grew slower and had 30% lower final biomass concentration compared to the parent strain, yet produced 75% more ethanol. A ldh pta double mutant strain evolved for faster growth had growth rate and ethanol yield comparable to the parent strain, whereas its biomass accumulation was comparable to pta. Free amino acids were secreted by all examined strains, with both pta strains secreting higher amounts of alanine, valine, isoleucine, proline, glutamine, and threonine. Valine concentration for ldh pta reached 5 mM by the end of growth, or 2.7% of the substrate carbon utilized. These secreted amino acid concentrations correlate with increased intracellular pyruvate concentrations, up to 6-fold in the pta and 16-fold in the ldh pta strain. We hypothesize that the deletions in fermentation end product pathways result in an intracellular redox imbalance, which the organism attempts to relieve, in part by recycling NADP+ through increased production of amino acids.

  20. Radiometric analysis of raw materials and end products in the Turkish ceramics industry

    Science.gov (United States)

    Turhan, Ş.; Arıkan, İ. H.; Demirel, H.; Güngör, N.

    2011-05-01

    This study presents the findings of radiometric analysis carried out to determine the activity concentrations of natural radionuclides in raw materials (clay, kaolin, quartz, feldspar, dolomite, alumina, bauxite, zirconium minerals, red mud and frit) and end products (glazed ceramic wall and floor tiles) in the Turkish ceramics industry. Hundred forty-six samples were obtained from various manufacturers and suppliers throughout the country and analyzed using gamma-ray spectrometer with HPGe detectors. Radiological parameters such as radium equivalent activity, activity concentration index and alpha index were calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant national and international legislation and guidance and compared with the results of similar studies reported in different countries. The results suggest that the use of ceramic end product samples examined in the construction of dwellings, workplaces and industrial buildings in Turkey is unlikely to give rise to any significant radiation exposure to the occupants.

  1. Radiometric analysis of raw materials and end products in the Turkish ceramics industry

    International Nuclear Information System (INIS)

    Turhan, S.; Arikan, I.H.; Demirel, H.; Guengoer, N.

    2011-01-01

    This study presents the findings of radiometric analysis carried out to determine the activity concentrations of natural radionuclides in raw materials (clay, kaolin, quartz, feldspar, dolomite, alumina, bauxite, zirconium minerals, red mud and frit) and end products (glazed ceramic wall and floor tiles) in the Turkish ceramics industry. Hundred forty-six samples were obtained from various manufacturers and suppliers throughout the country and analyzed using gamma-ray spectrometer with HPGe detectors. Radiological parameters such as radium equivalent activity, activity concentration index and alpha index were calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant national and international legislation and guidance and compared with the results of similar studies reported in different countries. The results suggest that the use of ceramic end product samples examined in the construction of dwellings, workplaces and industrial buildings in Turkey is unlikely to give rise to any significant radiation exposure to the occupants.

  2. Ligand binding affinity and changes in the lateral diffusion of receptor for advanced glycation endproducts (RAGE).

    Science.gov (United States)

    Syed, Aleem; Zhu, Qiaochu; Smith, Emily A

    2016-12-01

    The effect of ligand on the lateral diffusion of receptor for advanced glycation endproducts (RAGE), a receptor involved in numerous pathological conditions, remains unknown. Single particle tracking experiments that use quantum dots specifically bound to hemagglutinin (HA)-tagged RAGE (HA-RAGE) are reported to elucidate the effect of ligand binding on HA-RAGE diffusion in GM07373 cell membranes. The ligand used in these studies is methylglyoxal modified-bovine serum albumin (MGO-BSA) containing advanced glycation end products modifications. The binding affinity between soluble RAGE and MGO-BSA increases by 1.8 to 9.7-fold as the percent primary amine modification increases from 24 to 74% and with increasing negative charge on the MGO-BSA. Ligand incubation affects the HA-RAGE diffusion coefficient, the radius of confinement, and duration of confinement. There is, however, no correlation between MGO-BSA ligand binding affinity with soluble RAGE and the extent of the changes in HA-RAGE lateral diffusion. The ligand induced changes to HA-RAGE lateral diffusion do not occur when cholesterol is depleted from the cell membrane, indicating the mechanism for ligand-induced changes to HA-RAGE diffusion is cholesterol dependent. The results presented here serve as a first step in unraveling how ligand influences RAGE lateral diffusion. Copyright © 2016. Published by Elsevier B.V.

  3. Protein glycation and aggregation inhibitory potency of biomolecules from black gram milled by-product.

    Science.gov (United States)

    Girish, Talakatta K; Prasada Rao, Ummiti Js

    2016-12-01

    Persistent hyperglycaemia causes increased advanced glycation end products (AGEs), which contribute to the pathogenesis of diabetic complication. Therefore, effect of black gram milled by-product (BGBP) extract on inhibition of AGE formation in a bovine serum albumin (BSA)/glucose system was investigated. BGBP extract had a total polyphenol content of 82 mg GAE g -1 and flavonoid content of 46 mg CE g -1 . Ferulic acid, protocatechuic acid, gallic acid, gentisic acid, isovitexin, vitexin and epicatechin were the major bioactives in the extract. BGBP extract exhibited an effective Fe 2+ chelating activity. Size exclusion-high-performance liquid chromatographic studies indicated that upon BSA-AGE formation the BSA monomer content was 38%; however, in the presence of BGBP extract at 50 and 100 µg levels, the monomer content increased and it was found to be 48% and 73%, respectively. BGBP extract at 50 and 100 µg levels decreased the protein carbonyl and fructosamine contents, and quenched the fluorescence intensity of glycated BSA in a dose-dependent manner. Further, fluorescence and transmission electron microscopic studies confirmed the decrease in formation of AGEs by BGBP extract. As BGBP extract inhibited the formation of AGEs, the extract can be used as a nutraceutical or it can be incorporated into food products to obtain functional foods. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. N-phenacylthiazolium bromide reduces bone fragility induced by nonenzymatic glycation.

    Directory of Open Access Journals (Sweden)

    Brian S Bradke

    Full Text Available Nonenzymatic glycation (NEG describes a series of post-translational modifications in the collagenous matrices of human tissues. These modifications, known as advanced glycation end-products (AGEs, result in an altered collagen crosslink profile which impacts the mechanical behavior of their constituent tissues. Bone, which has an organic phase consisting primarily of type I collagen, is significantly affected by NEG. Through constant remodeling by chemical resorption, deposition and mineralization, healthy bone naturally eliminates these impurities. Because bone remodeling slows with age, AGEs accumulate at a greater rate. An inverse correlation between AGE content and material-level properties, particularly in the post-yield region of deformation, has been observed and verified. Interested in reversing the negative effects of NEG, here we evaluate the ability of n-phenacylthiazolium bromide (PTB to cleave AGE crosslinks in human cancellous bone. Cancellous bone cylinders were obtained from nine male donors, ages nineteen to eighty, and subjected to one of six PTB treatments. Following treatment, each specimen was mechanically tested under physiological conditions to failure and AGEs were quantified by fluorescence. Treatment with PTB showed a significant decrease in AGE content versus control NEG groups as well as a significant rebound in the post-yield material level properties (p<0.05. The data suggest that treatment with PTB could be an effective means to reduce AGE content and decrease bone fragility caused by NEG in human bone.

  5. Optimizing Carnosine Containing Extract Preparation from Chicken Breast for Anti-glycating agents.

    Science.gov (United States)

    Kim, Seung-Ki; Kwon, Dodan; Kwon, Da-Ae; Paik, In Kee; Auh, Joong-Hyuck

    2014-01-01

    Optimization of carnosine and anserine extraction from chicken breast was performed using response surface methodology (RSM) to obtain the maximized physiological activities for anti-glycation and anti-oxidation. The optimum extraction conditions were water extraction for 1.6 h in the case of the 20-wk laying hen muscle and water extraction for 2.12 h in the case of 90-wk laying hen muscle. Higher carnosine and anserine contents were measured in the 20-wk laying hen muscle, along with higher physiological activities, which increased in direct proportion with the dipeptide contents. The extracts prepared from the 20-wk laying hen under optimum conditions showed 57% inhibition of advanced glycated end-product formation, 64% inhibition of lipid peroxidation, and 61% of DPPH radical scavenging effects. On the other hand, 52% inhibition of AGE formation, 62% inhibition of lipid peroxidation, and 53% of DPPH radical scavenging effect were demonstrated within the 90-wk laying hen. In addition, the ratio of carnosine was a key indicator for the physiological activities of the extracts.

  6. Role of protein-bound carbonyl groups in the formation of advanced glycation endproducts.

    Science.gov (United States)

    Liggins, J; Furth, A J

    1997-08-22

    Several mechanisms have been postulated for the formation of advanced glycation endproducts (AGEs) from glycated proteins; they all feature protein-bound carbonyl intermediates. Using 2,4-dinitrophenylhydrazine (DNPH), we have detected these intermediates on bovine serum albumin, lysozyme and beta-lactoglobulin after in vitro glycation by glucose or fructose. Carbonyls were formed in parallel with AGE-fluorophores, via oxidative Maillard reactions. Neither Amadori nor Heyns products contributed to the DNPH reaction. Fluorophore and carbonyl yields were much enhanced in lipid-associated proteins, but both groups could also be detected in lipid-free proteins. When pre-glycated proteins were incubated in the absence of free sugar, carbonyl groups were rapidly lost in a first-order reaction, while fluorescence continued to develop beyond the 21 days of incubation. Another unexpected finding was that not all carbonyl groups were blocked by aminoguanidine, although there was complete inhibition of reactions leading to AGE-fluorescence. It is suggested that carbonyls acting as fluorophore precursors react readily with aminoguanidine, while others are resistant to this hydrazine, possibly because they are involved in ring closure. Factors influencing the relative rates of acyclisation and hydrazone formation are discussed, together with possible implications for antiglycation therapy.

  7. Intimal Surface Suture Line (End-Product Assessment of End-to-Side Microvascular Anastomosis

    Directory of Open Access Journals (Sweden)

    Georgios Pafitanis, MD

    2017-07-01

    Full Text Available Summary:. Microsurgery simulation courses increasingly use assessment methodologies to evaluate the quality of microvascular anastomosis and to provide constructive feedback in competency-based training. Assessment tools evaluating the “journey” of skill acquisition in anastomosis have evolved, including global rating scores, hand motion analysis, and evaluation of the final outcome, that is, “end-product” assessment. Anastomotic patency is the gold standard end-product in clinical microvascular surgery, and in vivo end-to-side anastomosis, which can be confirmed using the Acland-test. Microsurgery simulation training is moving to include nonliving models, where possible, according to the principles of the replacement, reduction, and refinement of the use of animals in research. While a standardized end-product assessment tool for nonliving end-to-end anastomosis exists, there is no similar tool for end-to-side anastomosis. Intimal surface suture line assessment is an error list-based tool, which involves exposing the intimal surface of a vessel and analysis of the quality of suture placement. Errors in end-to side anastomosis were classified according to the potential clinical significance (high, medium, or low perceived by the senior authors. Intimal surface suture line assessment provides constructive feedback during microsurgery training, helping to minimize technical errors, which are likely to impact on the final outcome in a clinical environment. Intimal surface suture line assessment lends itself to nonliving simulation training courses as an end-product self-assessment tool, especially during the early learning curve, to demonstrate progression. It has intraoperative relevance by assessment of the intimal surface suture line as the final sutures are placed in an end-to-side anastomosis to provide objective feedback to trainees in relation to likely physiological anastomotic outcome.

  8. Effects of end-product inhibition of Cellulomonas uda anaerobic growth on cellobiose chemostat culture.

    Science.gov (United States)

    Dermoun, Z; Gaudin, C; Belaich, J P

    1988-01-01

    Cellulomonas uda was grown anaerobically in a chemostat with 3.33 and 11.41 mM cellobiose in the feed medium at dilution rates varying from 0.017 to 0.29/h. Unusual results obtained were analyzed by using curves simulating the steady-state biomass. This unusual behavior could be accounted for by a classical growth model taking end-product inhibition into account. Acetate has been identified to be the major inhibitor in the experimental conditions used. Parameters calculated from experimental observations gave theoretical curves of biomass production versus dilution rate which fitted the experimental points very well. PMID:3131311

  9. Beneficial Effects of Lemon Balm Leaf Extract on In Vitro Glycation of Proteins, Arterial Stiffness, and Skin Elasticity in Healthy Adults.

    Science.gov (United States)

    Yui, Shintaro; Fujiwara, Suzuka; Harada, Katsuhisa; Motoike-Hamura, Mahoko; Sakai, Masashi; Matsubara, Satoshi; Miyazaki, Kouji

    2017-01-01

    Glycation, a non-enzymatic glycosylation of proteins, induces tissue damage in association with various diseases and aging phenomena. Pentosidine, an advanced glycation end product, is involved in aging phenomena such as tissue stiffness. In this study, we aimed to find a potent anti-glycation food material and to verify its health benefits by clinical trial. From among 681 hot water plant extracts, lemon balm (Melissa officinalis; LB) leaf extract was selected and revealed to have more potent inhibitory activity for pentosidine formation than a representative anti-glycation agent, aminoguanidine. Rosmarinic acid (RA), a typical polyphenol in Lamiaceae plants, was identified as a major active component in LB extract (LBE). Furthermore, LBE or RA dose-dependently suppressed glycation-associated reactions such as increased fluorescence, yellowing of collagen fiber sheets, and degeneration of the fibrous structure of elastin fiber sheets. An open-label, parallel-group comparative trial was conducted in 28 healthy Japanese subjects aged 31-65 y who consumed LB tea (LB group) or barley tea (Control group) for 6 wk. The LB group showed significant reductions in brachial-ankle pulse wave velocity, reflecting arterial stiffness, and b* (yellow) color values in forearm skin compared with the Control group. A gender-stratified analysis revealed that cheek skin elasticity was significantly improved in the LB group compared with the Control group only in female subjects. It is concluded that the hot water extract of LB leaf has the potential to provide health benefits with regard to glycation-associated tissue damage in blood vessels and skin of healthy adults.

  10. Effects of end products on fermentation profiles in Clostridium carboxidivorans P7 for syngas fermentation.

    Science.gov (United States)

    Zhang, Jie; Taylor, Steven; Wang, Yi

    2016-10-01

    Clostridium carboxidivorans P7 is a strict anaerobic bacterium capable of converting syngas to biofuels. However, its fermentation profiles is poorly understood. Here, various end-products, including acetic acid, butyric acid, hexanoic acid, ethanol and butanol were supplemented to evaluate their effects on fermentation profiles in C. carboxidivorans at two temperatures. At 37°C, fatty acids addition likely led to more corresponding alcohols production. At 25°C, C2 and C4 fatty acids supplementation resulted in more corresponding higher fatty acids, while supplemented hexanoic acid increased yields of C2 and C4 fatty acids and hexanol. Supplementation of ethanol or butanol caused increased production of C2 and C4 acids at both temperatures; however, long-chain alcohols were still more likely produced at lower temperature. In conclusion, fermentation profiles of C. carboxidivorans can be changed in respond to pre-added end-products and carbon flow may be redirected to desired products by controlling culture conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Intracellular glutathione production, but not protein glycation, underlies the protective effects of captopril against 2-deoxy-D-ribose-induced β-cell damage.

    Science.gov (United States)

    Koh, Gwanpyo; Yang, Eun-Jin; Kim, Ji Young; Hyun, Jonghoon; Yoo, Soyeon; Lee, Sang Ah

    2015-10-01

    Our previous study reported that both oxidative stress and protein glycation were the principal mechanisms underlying 2‑deoxy‑D‑ribose (dRib)‑induced pancreatic β‑cell damage. The aim of the present study was to investigate the effects of captopril on dRib‑induced damage in pancreatic β‑cells, as well as to determine the mechanisms underlying these effects. Treatment with dRib increased the levels of cytotoxicity, apoptosis, and intracellular reactive oxygen species in Syrian hamster insulinoma HIT‑T15 cells; however, pretreatment with captopril significantly inhibited the effects of dRib. The intracellular levels of reduced and oxidized glutathione were depleted following treatment with dRib; however, these levels were restored following HIT‑T15 cell treatment with captopril. In rat islets, dRib stimulation suppressed the mRNA expression levels of insulin, and pancreatic and duodenal homeobox 1, as well as insulin content; however, these effects were dose‑dependently reversed by treatment with captopril. Treatment with buthionine sulfoximine, an inhibitor of intracellular glutathione biosynthesis, inhibited the protective effects of captopril on dRib‑mediated glutathione depletion and cytotoxicity in HIT‑T15 cells. Following incubation with albumin, dRib increased the formation of dicarbonyl and advanced glycation end products. Treatment with captopril did not inhibit the dRib‑induced increase in production of dicarbonyl and advanced glycation end products. In conclusion, treatment with captopril reversed dRib‑induced oxidative damage and suppression of insulin expression in β‑cells. The mechanism underlying the protective effects of captopril may involve increased intracellular glutathione production, rather than protein glycation.

  12. Effects of feeding polydextrose on faecal characteristics, microbiota and fermentative end products in healthy adult dogs.

    Science.gov (United States)

    Beloshapka, Alison N; Wolff, Amanda K; Swanson, Kelly S

    2012-08-01

    Polydextrose is a potential prebiotic, but has not been well tested in dogs. Thus, the objective of the present study was to determine the effects of polydextrose on faecal characteristics, microbial populations and fermentative end products in healthy adult dogs. A total of eight adult hound dogs (3.5 (sem 0.5) years; 20 (sem 0.5) kg) were randomly allotted to one of four test diets containing the following concentrations of polydextrose: (1) 0 % (control); (2) 0.5 %; (3) 1.0 %; or (4) 1.5 %. A Latin square design was used, with each treatment period lasting 14 d (days 0-10 adaptation; days 11-14 fresh and total faecal collection). All dogs were fed to maintain body weight. Data were evaluated for linear and quadratic effects using SAS software. Although apparent total tract DM digestibility was unaffected, total tract crude protein digestibility tended to decrease (P dogs.

  13. Combining UHPLC-High Resolution MS and Feeding of Stable Isotope Labeled Polyketide Intermediates for Linking Precursors to End Products

    DEFF Research Database (Denmark)

    Klitgaard, Andreas; Frandsen, Rasmus John Normand; Holm, Dorte Koefoed

    2015-01-01

    acid (6-MSA) and 13C14-YWA1, both produced in-house, as well as commercial 13C7-benzoic acid and 2H7-cinnamic acid, in species of Fusarium, Byssochlamys, Aspergillus, and Penicillium. Incorporation of 6-MSA into terreic acid or patulin was not observed in any of six evaluated species covering three...... genera, because the 6-MSA was shunted into (2Z,4E)-2-methyl-2,4-hexadienedioic acid. This indicates that patulin and terreic acid may be produced in a closed compartment of the cell and that (2Z,4E)-2-methyl-2,4-hexadienedioic acid is a detoxification product toward terreic acid and patulin. In Fusarium...... spp., YWA1 was shown to be incorporated into aurofusarin, rubrofusarin, and antibiotic Y. In A. niger, benzoic acid was shown to be incorporated into asperrubrol. Incorporation levels of 0.7–20% into the end-products were detected in wild-type strains. Thus, stable isotope labeling is a promising...

  14. Effects of thyroid status on glycated hemoglobin

    OpenAIRE

    Bhattacharjee, Rana; Thukral, Anubhav; Chakraborty, Partha Pratim; Roy, Ajitesh; Goswami, Soumik; Ghosh, Sujoy; Mukhopadhyay, Pradip; Mukhopadhyay, Satinath; Chowdhury, Subhankar

    2017-01-01

    Introduction: Glycated hemoglobin (HbA1c) can be altered in different conditions. We hypothesize that HbA1c levels may change due to altered thyroid status, possibly due to changes in red blood cell (RBC) turnover. Objectives: The objective of this study was to determine the effects of altered thyroid status on HbA1c levels in individuals without diabetes, with overt hyper- and hypo-thyroidism, and if present, whether such changes in HbA1c are reversed after achieving euthyroid state. Methods...

  15. Treatment of periodontal disease in diabetics reduces glycated hemoglobin.

    Science.gov (United States)

    Grossi, S G; Skrepcinski, F B; DeCaro, T; Robertson, D C; Ho, A W; Dunford, R G; Genco, R J

    1997-08-01

    Periodontal disease is a common infection-induced inflammatory disease among individuals suffering from diabetes mellitus. The purpose of this study was to assess the effects of treatment of periodontal disease on the level of metabolic control of diabetes. A total of 113 Native Americans (81 females and 32 males) suffering from periodontal disease and non-insulin dependent diabetes mellitus (NIDDM) were randomized into 5 treatment groups. Periodontal treatment included ultrasonic scaling and curettage combined with one of the following antimicrobial regimens: 1) topical water and systemic doxycycline, 100 mg for 2 weeks; 2) topical 0.12% chlorhexidine (CHX) and systemic doxycycline, 100 mg for 2 weeks; 3) topical povidone-iodine and systemic doxycycline, 100 mg for 2 weeks; 4) topical 0.12% CHX and placebo; and 5) topical water and placebo (control group). Assessments were performed prior to and at 3 and 6 months after treatment and included probing depth (PD), clinical attachment level (CAL), detection of Porphyromonas gingivalis in subgingival plaque and determination of serum glucose and glycated hemoglobin (HbA1c). After treatment all study groups showed clinical and microbial improvement. The doxycycline-treated groups showed the greatest reduction in probing depth and subgingival Porphyromonas gingivalis compared to the control group. In addition, all 3 groups receiving systemic doxycycline showed, at 3 months, significant reductions (P periodontal infection and reduction of periodontal inflammation is associated with a reduction in level of glycated hemoglobin. Control of periodontal infections should thus be an important part of the overall management of diabetes mellitus patients.

  16. GLYCATED HEMOGLOBIN AND FRUCTOSAMINE IN DOGS WITH DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    Olair Carlos Beltrame

    2015-10-01

    Full Text Available Diabetes mellitus (DM commonly occurs in dogs, and the laboratorial confirmation is carried out by glycemia test. The diagnosis and monitoring in humans is made by glycated hemoglobin and fructosamine concentrations. The objective of this study was to diagnose DM in 19 dogs, by evaluating seric glucose, glycated hemoglobin and fructosamine concentrations. Six dogs with DM and treated with insulin were assisted during a twelve-month period, by means of the same blood analysis, until the death (three dogs or glycemic control (three dogs. Glucose, glycated hemoglobin and fructosamine increased in all dogs with DM, and dogs that did not survive presented higher glycated hemoglobin and seric glucose values than those that survived at the last evaluation. The results showed the importance of evaluating glycated hemoglobin and fructosamine in dogs with DM to diagnose and control treatment effectiveness.

  17. Age-adjusted glycated albumin accurately reflects blood glucose in patients with neonatal diabetes mellitus: comparison with calculated glycated albumin determined by past blood glucose concentrations.

    Science.gov (United States)

    Suzuki, Shigeru; Furuya, Akiko; Oshima, Miho; Amamiya, Satoshi; Nakao, Atsushi; Wada, Keiko; Okuhara, Koji; Hayano, Satoshi; Imamoto, Aya; Matsuo, Kumihiro; Tanahashi, Yusuke; Azuma, Hiroshi; Koga, Masafumi

    2016-01-01

    Glycated albumin is a useful glycaemic control indicator for neonatal diabetes mellitus. However, glycated albumin concentrations in infants are lower than those in adults and increase in an age-dependent manner. Based on our investigation of non-diabetic subjects, we proposed the possibility that the reference range for adults may be used regardless of age, provided that age-adjusted glycated albumin is employed. In the present study, we evaluate the usefulness of age-adjusted glycated albumin in neonatal diabetes mellitus patients. Six neonatal diabetes mellitus patients (four patients with permanent neonatal diabetes mellitus and two patients with transient neonatal diabetes mellitus) were included. Measured glycated albumin or age-adjusted glycated albumin was compared to calculated glycated albumin, which was determined using calculation formulae we had reported based on past blood glucose over the 50 days before measurement of glycated albumin. Measured glycated albumin was significantly lower than calculated glycated albumin (20.5 ± 4.9% versus 28.2 ± 6.1%; p diabetes mellitus in remission were lower than the reference range for adults, whereas age-adjusted glycated albumin concentrations were within the reference range for adults. We demonstrated that age-adjusted glycated albumin concentrations were consistent with calculated glycated albumin. Age-adjusted glycated albumin is therefore a useful glycaemic control indicator for neonatal diabetes mellitus patients. © The Author(s) 2015.

  18. Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs.

    Science.gov (United States)

    Sandri, Misa; Dal Monego, Simeone; Conte, Giuseppe; Sgorlon, Sandy; Stefanon, Bruno

    2017-02-28

    Dietary intervention studies are required to deeper understand the variability of gut microbial ecosystem in healthy dogs under different feeding conditions and to improve diet formulations. The aim of the study was to investigate in dogs the influence of a raw based diet supplemented with vegetable foods on faecal microbiome in comparison with extruded food. Eight healthy adult Boxer dogs were recruited and randomly divided in two experimental blocks of 4 individuals. Dogs were regularly fed a commercial extruded diet (RD) and starting from the beginning of the trial, one group received the raw based diet (MD) and the other group continued to be fed with the RD diet (CD) for a fortnight. After 14 days, the two groups were inverted, the CD group shifted to the MD and the MD shifted to the CD, for the next 14 days. Faeces were collected at the beginning of the study (T0), after 14 days (T14) before the change of diet and at the end of experimental period (T28) for DNA extraction and analysis of metagenome by sequencing 16SrRNA V3 and V4 regions, short chain fatty acids (SCFA), lactate and faecal score. A decreased proportion of Lactobacillus, Paralactobacillus (P diet significantly (P diet composition modifies faecal microbial composition and end products of fermentation. The administration of MD diet promoted a more balanced growth of bacterial communities and a positive change in the readouts of healthy gut functions in comparison to RD diet.

  19. Anti-atherosclerotic actions of azelaic acid, an end product of linoleic acid peroxidation, in mice.

    Science.gov (United States)

    Litvinov, Dmitry; Selvarajan, Krithika; Garelnabi, Mahdi; Brophy, Larissa; Parthasarathy, Sampath

    2010-04-01

    Atherosclerosis is a chronic inflammatory disease associated with the accumulation of oxidized lipids in arterial lesions. Recently we studied the degradation of peroxidized linoleic acid and suggested that oxidation is an essential process that results in the generation of terminal products, namely mono- and dicarboxylic acids that may lack the pro-atherogenic effects of peroxidized lipids. In continuation of that study, we tested the effects of azelaic acid (AzA), one of the end products of linoleic acid peroxidation, on the development of atherosclerosis using low density lipoprotein receptor knockout (LDLr(-/-)) mice. LDLr(-/-) mice were fed with a high fat and high cholesterol Western diet (WD group). Another group of animals were fed the same diet with AzA supplementation (WD+AzA group). After 4 months of feeding, mice were sacrificed and atherosclerotic lesions were measured. The results showed that the average lesion area in WD+AzA group was 38% (pacids could be an important step in the body's defense against oxidative damage. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  20. Hb Melusine and Hb Athens-Georgia: potentially underreported in the Belgian population? Four cases demonstrating the lack of detection using common CE-HPLC methods either for glycated hemoglobin (HbA1C) analysis or Hb variant screening.

    Science.gov (United States)

    Peeters, Bart; Brandt, Inger; Desmet, Koenraad; Harteveld, Cornelis L; Kieffer, Davy

    2016-12-01

    Suspected hemoglobin (Hb) variants, detected during HbA 1C measurements should be further investigated, determining the extent of the interference with each method. This is the first report of Hb Melusine and Hb Athens-Georgia in Caucasian Belgian patients. Intervention & Technique: Since common CE-HPLC methods for HbA 1C analysis or Hb variant screening are apparently unable to detect these Hb variants, their presence might be underestimated. HbA 1C analysis using CZE, however, alerted for their presence. Moreover, in case of Hb Melusine, even Hb variant screening using CZE was unsuccessful in its detection. Fortunately, carriage of Hb Melusine or Hb Athens-Georgia variants has no clinical implications and, as shown in this report, no apparent difference in HbA 1C should be expected.

  1. Human Achilles tendon glycation and function in diabetes

    DEFF Research Database (Denmark)

    Couppe, Christian; Svensson, Rene Brüggebusch; Kongsgaard, Mads

    2016-01-01

    Diabetic patients have an increased risk of foot ulcers, and glycation of collagen may increase tissue stiffness. We hypothesized that the level of glycemic control (glycation) may affect Achilles tendon stiffness, which can influence gait pattern. We therefore investigated the relationship between...... collagen glycation, Achilles tendon stiffness parameters and plantar pressure in poorly (n = 22) and well (n = 22) controlled diabetic patients, including healthy age matched (45-70 yrs) controls (n = 11). There were no differences in any of outcome parameters (collagen cross-linking or tendon stiffness...... concentrations (55%, P tendon material stiffness was higher in DB (54%, P tendon material stiffness and skin connective...

  2. Hexose-derived glycation sites in processed bovine milk.

    Science.gov (United States)

    Milkovska-Stamenova, Sanja; Hoffmann, Ralf

    2016-02-16

    Milk products are consumed by many people on a daily basis, which demands sophisticated technical processes to guarantee the microbiological safety and to retain the nutritional value. The heating during pasteurization and ultra high temperature (UHT) treatment triggers diverse chemical reactions, such as the reaction of sugars and amino groups of proteins typically termed protein glycation. The glycation by lactose as dominant sugar in milk has been recently investigated, whereas the contribution of hexoses remains open. We identified first hexose-derived glycation sites in raw milk, colostrum, three brands of pasteurized milk, three brands of UHT milk, five brands of infant formula, and one brand of lactose-free pasteurized and UHT milk using tandem mass spectrometry and electron transfer dissociation. In total, we could identify 124 hexosylated tryptic peptides in a bottom-up proteomics approach after enriching glycated peptides by boronate affinity chromatography, which corresponded to 86 glycation sites in 17 bovine milk proteins. In quantitative terms glycation increased from raw milk to pasteurized milk to UHT milk and infant formula. Lactose-free milk contained significantly higher hexosylation degrees than the corresponding regular milk product. Interestingly, the glycation degrees varied considerably among different brands with lactose-free UHT milk and infant formula showing the highest levels. The established proteomics strategy enables the identification and relative quantification of different protein glycation types in diverse milk products ranging from raw milk to milk powders. This will allow detailed in vitro studies to judge positive or negative aspects when consuming differently processed milk products including lactose-free milk that is obligatory for people with lactose intolerance but is increasingly consumed by the general population assuming health benefits. The established analytics will also permit studying the influence of each technical

  3. Sorption of biodegradation end products of nonylphenol polyethoxylates onto activated sludge.

    Science.gov (United States)

    Hung, Nguyen Viet; Tateda, Masafumi; Ike, Michihiko; Fujita, Masanori; Tsunoi, Shinji; Tanaka, Minoru

    2004-01-01

    Nonylphenol(NP), nonylphenoxy acetic acid (NP1EC), nonylphenol monoethoxy acetic acid (NP2EC), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) are biodegradation end products (BEPs) of nonionic surfactant nonylphenolpolyethoxylates (NPnEO). In this research, sorption of these compounds onto model activated sludge was characterized. Sorption equilibrium experiments showed that NP, NP1EO and NP2EO reached equilibrium in about 12 h, while equilibrium of NP1EC and NP2EC were reached earlier, in about 4 h. In sorption isotherm experiments, obtained equilibrium data at 28 degrees C fitted well to Freundlich sorption model for all investigated compounds. For NP1EC, in addition to Freundlich, equilibrium data also fitted well to Langmuir model. Linear sorption model was also tried, and equilibrium data of all NP, NP1EO, NP2EO and NP2EC except NP1EC fitted well to this model. Calculated Freundlich coefficient (K(F)) and linear sorption coefficient (K(D)) showed that sorption capacity of the investigated compounds were in order NP > NP2EO > NP1EO > NP1EC approximately NP2EC. For NP, NP1EO and NP2EO, high values of calculated K(F) and K(D) indicated an easy uptake of these compounds from aqueous phase onto activated sludge. Whereas, NP1EC and NP2EC with low values of K(F) and K(D) absorbed weakly to activated sludge and tended to preferably remain in aqueous phase.

  4. Anti-Glycation Effects of Pomegranate (Punica granatum L.) Fruit Extract and Its Components in Vivo and in Vitro.

    Science.gov (United States)

    Kumagai, Yuya; Nakatani, Sachie; Onodera, Hideaki; Nagatomo, Akifumi; Nishida, Norihisa; Matsuura, Yoichi; Kobata, Kenji; Wada, Masahiro

    2015-09-09

    Accumulation of advanced glycation end products (AGEs) leads to various diseases such as diabetic complications and arteriosclerosis. In this study, we examined the effect of pomegranate fruit extract (PFE) and its constituent polyphenols on AGE formation in vivo and in vitro. PFE, fed with a high-fat and high-sucrose (HFS) diet to KK-A(y) mice, significantly reduced glycation products such as glycoalbumin (22.0 ± 2.4%), hemoglobin A1c (5.84 ± 0.23%), and serum AGEs (8.22 ± 0.17 μg/mL), as compared to a control HFS group (30.6 ± 2.6%, 7.45 ± 0.12%, and 9.55 ± 0.17 μg/mL, respectively, P < 0.05). In antiglycation assays, PFE, punicalin, punicalagin, ellagic acid, and gallic acid suppressed the formation of AGEs from bovine serum albumin and sugars. In this study, we discuss the mechanism of the antiglycation effects of PFE and its components in vivo and in vitro.

  5. The Influence of Glycated Hemoglobin on the Cross Susceptibility Between Type 1 Diabetes Mellitus and Periodontal Disease.

    Science.gov (United States)

    Lappin, David F; Robertson, Douglas; Hodge, Penny; Treagus, David; Awang, Raja A; Ramage, Gordon; Nile, Christopher J

    2015-11-01

    Periodontal disease is a major complication of type 1 diabetes mellitus (T1DM). The aim of the present study is to investigate the relationship between glycated hemoglobin and circulating levels of interleukin (IL)-6, IL-8, and C-X-C motif chemokine ligand 5 (CXCL5) in non-smoking patients suffering from T1DM, with and without periodontitis. In addition, to determine the effect of advanced glycation end products (AGE) in the presence and absence of Porphyromonas gingivalis lipopolysaccharide (LPS) on IL-6, IL-8, and CXCL5 expression by THP-1 monocytes and OKF6/TERT-2 cells. There were 104 participants in the study: 19 healthy volunteers, 23 patients with periodontitis, 28 patients with T1DM, and 34 patients with T1DM and periodontitis. Levels of blood glucose/glycated hemoglobin (International Federation of Clinical Chemistry [IFCC]) were determined by high-performance liquid chromatography. Levels of IL-6, IL-8, and CXCL5 in plasma were determined by enzyme-linked immunosorbent assay (ELISA). In vitro stimulation of OKF6/TERT-2 cells and THP-1 monocytes was performed with combinations of AGE and P. gingivalis LPS. Changes in expression of IL-6, IL-8, and CXCL5 were monitored by ELISA and real-time polymerase chain reaction. Patients with diabetes and periodontitis had higher plasma levels of IL-8 than patients with periodontitis alone. Plasma levels of IL-8 correlated significantly with IFCC units, clinical probing depth, and attachment loss. AGE and LPS, alone or in combination, stimulated IL-6, IL-8, and CXCL5 expression in both OKF6/TERT-2 cells and THP-1 monocytes. Elevated plasma levels of IL-8 potentially contribute to the cross-susceptibility between periodontitis and T1DM. P. gingivalis LPS and AGE in combination caused significantly greater expression of IL-6, IL-8, and CXCL5 from THP-1 monocytes and OKF6/TERT-2 cells than LPS alone.

  6. Bimolecular interaction of argpyrimidine (a Maillard reaction product) in in vitro non-enzymatic protein glycation model and its potential role as an antiglycating agent.

    Science.gov (United States)

    Bhattacherjee, Abhishek; Dhara, Kaliprasanna; Chakraborti, Abhay Sankar

    2017-09-01

    Non- enzymatic glycation, also known as Maillard reaction, is one of the most important and investigated reactions in biochemistry. Maillard reaction products (MRPs) like protein-derived advanced glycation end products (AGEs) are often referred to cause pathophysiological complications in human systems. On contrary, several MRPs are exogenously used as antioxidant, antimicrobial and flavouring agents. In the preset study, we have shown that argpyrimidine, a well-established AGE, interacts with bovine serum albumin (BSA) and glucose individually in standard BSA-glucose model system and successfully inhibits glycation of the protein. Bimolecular interaction of argpyrimidine with glucose or BSA has been studied independently. Chromatographic purification, different spectroscopic studies and molecular modeling have been used to evaluate the nature and pattern of interactions. Binding of argpyrimidine with BSA prevents incorporation of glucose inside the native protein. Argpyrimidine can also directly entrap glucose. Both these interactions may be associated with the antiglycation potential of argpyrimidine, indicating a beneficial function of an AGE. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Effects of preservation conditions of canine feces on in vitro gas production kinetics and fermentation end-products

    NARCIS (Netherlands)

    Bosch, G.; Wrigglesworth, D.J.; Cone, J.W.; Pellikaan, W.F.; Hendriks, W.H.

    2013-01-01

    This study investigated the effect of chilling and freezing (for 24 h) canine feces on in vitro gas production kinetics and fermentation end-product profiles from carbohydrate-rich (in vitro run 1) and protein-rich substrates (in vitro run 2). Feces were collected from 3 adult Retriever-type dogs

  8. Changes in the fermentation end-product profile in the GIT of piglets during post-colostrum suckling period

    NARCIS (Netherlands)

    Awati, A.; Urso, D' S.; Williams, B.A.; Bosch, M.; Verstegen, M.W.A.

    2007-01-01

    Pre-weaning development of microbial activity has an effect on post-weaning establishment of the gastro-intestinal tract (GIT) microbiota. An in vivo study was conducted, to evaluate the effect of age on fermentation end-product profiles during the post-colostrum suckling period, as the variation in

  9. Incubation of selected fermentable fibres with feline faecal inoculum: correlations between in vitro fermentation characteristics and end products

    NARCIS (Netherlands)

    Rochus, K.; Bosch, G.; Vanhaecke, L.; Velde, van de H.; Depauw, S.; Xu, J.; Fievez, V.; Wiele, van der T.; Hendriks, W.H.; Janssens, G.P.J.; Hesta, M.

    2013-01-01

    This study aimed to evaluate correlations between fermentation characteristics and end products of selected fermentable fibres (three types of fructans, citrus pectin, guar gum), incubated with faecal inocula from donor cats fed two diets, differing in fibre and protein sources and concentrations.

  10. GLYCATED HEMOGLOBIN AND FRUCTOSAMINE IN DOGS WITH DIABETES MELLITUS

    OpenAIRE

    Olair Carlos Beltrame; Rosangela Locatelli-Dittrich; Luciane Maria Laskoski; Lia Fordiani Lenati Patricio; Nina da Cunha Medeiros; Marília Oliveira Koch

    2015-01-01

    Diabetes mellitus (DM) commonly occurs in dogs, and the laboratorial confirmation is carried out by glycemia test. The diagnosis and monitoring in humans is made by glycated hemoglobin and fructosamine concentrations. The objective of this study was to diagnose DM in 19 dogs, by evaluating seric glucose, glycated hemoglobin and fructosamine concentrations. Six dogs with DM and treated with insulin were assisted during a twelve-month period, by means of the same blood analysis, until the death...

  11. Modulation of keratinocyte expression of antioxidants by 4-hydroxynonenal, a lipid peroxidation end product

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ruijin [Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Heck, Diane E. [Environmental Health Science, New York Medical College, Valhalla, NY (United States); Mishin, Vladimir; Black, Adrienne T. [Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Shakarjian, Michael P. [Environmental Health Science, New York Medical College, Valhalla, NY (United States); Kong, Ah-Ng Tony; Laskin, Debra L. [Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Environmental and Occupational Medicine, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2014-03-01

    4-Hydroxynonenal (4-HNE) is a lipid peroxidation end product generated in response to oxidative stress in the skin. Keratinocytes contain an array of antioxidant enzymes which protect against oxidative stress. In these studies, we characterized 4-HNE-induced changes in antioxidant expression in mouse keratinocytes. Treatment of primary mouse keratinocytes and PAM 212 keratinocytes with 4-HNE increased mRNA expression for heme oxygenase-1 (HO-1), catalase, NADPH:quinone oxidoreductase (NQO1) and glutathione S-transferase (GST) A1-2, GSTA3 and GSTA4. In both cell types, HO-1 was the most sensitive, increasing 86–98 fold within 6 h. Further characterization of the effects of 4-HNE on HO-1 demonstrated concentration- and time-dependent increases in mRNA and protein expression which were maximum after 6 h with 30 μM. 4-HNE stimulated keratinocyte Erk1/2, JNK and p38 MAP kinases, as well as PI3 kinase. Inhibition of these enzymes suppressed 4-HNE-induced HO-1 mRNA and protein expression. 4-HNE also activated Nrf2 by inducing its translocation to the nucleus. 4-HNE was markedly less effective in inducing HO-1 mRNA and protein in keratinocytes from Nrf2 −/− mice, when compared to wild type mice, indicating that Nrf2 also regulates 4-HNE-induced signaling. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation demonstrated that 4-HNE-induced HO-1 is localized in keratinocyte caveolae. Treatment of the cells with methyl-β-cyclodextrin, which disrupts caveolar structure, suppressed 4-HNE-induced HO-1. These findings indicate that 4-HNE modulates expression of antioxidant enzymes in keratinocytes, and that this can occur by different mechanisms. Changes in expression of keratinocyte antioxidants may be important in protecting the skin from oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a reactive aldehyde. • 4-HNE induces antioxidant proteins in mouse keratinocytes. • Induction of

  12. Inhibition of Protein Glycation by Tiger Milk Mushroom [Lignosus rhinocerus (Cooke Ryvarden] and Search for Potential Anti-diabetic Activity-Related Metabolic Pathways by Genomic and Transcriptomic Data Mining

    Directory of Open Access Journals (Sweden)

    Hui-Yeng Y. Yap

    2018-02-01

    Full Text Available Naturally occurring anti-glycation compounds have drawn much interest in recent years as they show potential in reducing or preventing the risk of chronic complications for diabetic patients. In this study, annotation of the genome–transcriptome data from tiger milk mushroom (Lignosus rhinocerus, syn. Lignosus rhinocerotis to PlantCyc enzymes database identified transcripts that are related to anti-diabetic properties, and these include genes that are involved in carotenoid and abscisic acid biosynthesis as well as genes that code for glyoxalase I, catalase-peroxidases, and superoxide dismutases. The existence of these genes suggests that L. rhinocerus may contain bioactive compound(s with anti-glycation properties that can be exploited for management of diabetic complications. A medium-molecular-weight (MMW fraction which was obtained from a combination of cold water extraction and Sephadex® G-50 (fine gel filtration chromatography of L. rhinocerus sclerotia powder was demonstrated to exhibit potent anti-glycation activity. The fraction specifically inhibited the formation of N-(carboxymethyllysine, pentosidine, and other advanced glycation end-product (AGE structures in a human serum albumin-glucose system, with an IC50 value of 0.001 mg/ml, almost 520 times lower than that of the positive control, aminoguanidine hydrochloride (IC50 = 0.52 mg/ml. Its ability to suppress protein glycation may be partly associated with its strong superoxide anion radical scavenging activity (10.16 ± 0.12 mmol TE/g. Our results suggest that the MMW fraction of L. rhinocerus shows potential to be developed into a potent glycation inhibitor for preventing AGE-mediated diabetic complications.

  13. Anthraquinones from the seeds of Cassia tora with inhibitory activity on protein glycation and aldose reductase.

    Science.gov (United States)

    Jang, Dae Sik; Lee, Ga Young; Kim, Young Sook; Lee, Yun Mi; Kim, Chan-Sik; Yoo, Jeong Lim; Kim, Jin Sook

    2007-11-01

    Nine anthraquinones, aurantio-obtusin (1), chryso-obtusin (2), obtusin (3), chryso-obtusin-2-O-beta-D-glucoside (4), physcion (5), emodin (6), chrysophanol (7), obtusifolin (8), and obtusifolin-2-O-beta-D-glucoside (9), isolated from an EtOAc-soluble extract of the seeds of Cassia tora, were subjected to in vitro bioassays to evaluate their inhibitory activity against advanced glycation end products (AGEs) formation and rat lens aldose reductase (RLAR). Among the isolates, compounds 6 and 8 exhibited a significant inhibitory activity on AGEs formation with observed IC(50) values of 118 and 28.9 microM, respectively, in an AGEs-bovine serum albumin (BSA) assay by specific fluorescence. Furthermore, compounds 6 and 8 inhibited AGEs-BSA formation more effectively than aminoguanidine, an AGEs inhibitor, by indirect AGEs-ELISA. N(epsilon)-Carboxymethyllysine (CML)-BSA formation was also inhibited by compounds 6 and 8. Whereas compounds 1, 4, and 6 showed a significant inhibitory activity on RLAR with IC(50) values of 13.6, 8.8, and 15.9 microM, respectively.

  14. The Inhibitory Effect of Prunella vulgaris L. on Aldose Reductase and Protein Glycation

    Directory of Open Access Journals (Sweden)

    Hong Mei Li

    2012-01-01

    Full Text Available To evaluate the aldose reductase (AR enzyme inhibitory ability of Prunella vulgaris L. extract, six compounds were isolated and tested for their effects. The components were subjected to in vitro bioassays to investigate their inhibitory assays using rat lens aldose reductase (rAR and human recombinant AR (rhAR. Among them, caffeic acid ethylene ester showed the potent inhibition, with the IC50 values of rAR and rhAR at 3.2±0.55 μM and 12.58±0.32 μM, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/concentration of substrate, this compound showed noncompetitive inhibition against rhAR. Furthermore, it inhibited galactitol formation in a rat lens incubated with a high concentration of galactose. Also it has antioxidative as well as advanced glycation end products (AGEs inhibitory effects. As a result, this compound could be offered as a leading compound for further study as a new natural products drug for diabetic complications.

  15. Evidence that L-Arginine inhibits glycation of human serum albumin (HSA) in vitro

    International Nuclear Information System (INIS)

    Servetnick, D.A.; Wiesenfeld, P.L.; Szepesi, B.

    1990-01-01

    Previous work by Brownlee has shown that glycation of bovine serum albumin can be reduced in the presence of aminoguanidine (AG). Presumably, the guanidinium group on AG interferes with further rearrangement of amadori products to advanced glycosylated end products (AGE). Since L-arginine (ARG) also contains a guanidinium group, its ability to inhibit the formation of AGE products was investigated. HSA was incubated at 37 degrees C in the presence or absence of glucose; with glucose and fructose; or with sugars in the presence or absence of ARG or AG. A tracer amount of U- 14 C-glucose was added to each tube containing sugars. Protein bound glucose was separated from unreacted glucose by gel filtration. Radioactivity, total protein, fluorescence, and glucose concentration were measured. Preliminary data show enhanced binding of 14 C-glucose to HSA with fructose at all time points. A 30-40% decrease in 14 C-glucose incorporation was observed when ARG or AG as present. ARG and AG were equally effective in inhibiting incorporation of 14 C-glucose. FPLC analysis is in progress to determine the type and degree of HSA crosslinking during the 2 week incubation period

  16. Nitration and Glycation Turn Mature NGF into a Toxic Factor for Motor Neurons: A Role for p75NTRand RAGE Signaling in ALS.

    Science.gov (United States)

    Kim, Mi Jin; Vargas, Marcelo R; Harlan, Benjamin A; Killoy, Kelby M; Ball, Lauren E; Comte-Walters, Susana; Gooz, Monika; Yamamoto, Yasuhiko; Beckman, Joseph S; Barbeito, Luis; Pehar, Mariana

    2017-06-26

    Glycating stress can occur together with oxidative stress during neurodegeneration and contribute to the pathogenic mechanism. Nerve growth factor (NGF) accumulates in several neurodegenerative diseases. Besides promoting survival, NGF can paradoxically induce cell death by signaling through the p75 neurotrophin receptor (p75 NTR ). The ability of NGF to induce cell death is increased by nitration of its tyrosine residues under conditions associated with increased peroxynitrite formation. Here we investigated whether glycation also changes the ability of NGF to induce cell death and assessed the ability of post-translational modified NGF to signal through the receptor for advanced glycation end products (RAGEs). We also explored the potential role of RAGE-p75 NTR interaction in the motor neuron death occurring in amyotrophic lateral sclerosis (ALS) models. Glycation promoted NGF oligomerization and ultimately allowed the modified neurotrophin to signal through RAGE and p75 NTR to induce motor neuron death at low physiological concentrations. A similar mechanism was observed for nitrated NGF. We provide evidence for the interaction of RAGE with p75 NTR at the cell surface. Moreover, we observed that post-translational modified NGF was present in the spinal cord of an ALS mouse model. In addition, NGF signaling through RAGE and p75 NTR was involved in astrocyte-mediated motor neuron toxicity, a pathogenic feature of ALS. Oxidative modifications occurring under stress conditions can enhance the ability of mature NGF to induce neuronal death at physiologically relevant concentrations, and RAGE is a new p75 NTR coreceptor contributing to this pathway. Our results indicate that NGF-RAGE/p75 NTR signaling may be a therapeutic target in ALS. Antioxid. Redox Signal. 00, 000-000.

  17. Neo-Epitopes Generated on Hydroxyl Radical Modified GlycatedIgG Have Role in Immunopathology of Diabetes Type 2.

    Directory of Open Access Journals (Sweden)

    Sidra Islam

    Full Text Available Glycoxidation plays a crucial role in diabetes and its associated complications. Among the glycoxidation agents, methylglyoxal (MG is known to have very highglycationpotential witha concomitant generation of reactive oxygen species (ROS during its synthesis and degradation. The presentstudy probes the MG and ROSinduced structural damage to immunoglobulin G (IgG and alterations in its immunogenicity in diabetes type 2 patients (T2DM. Human IgG was first glycated with MG followed by hydroxyl radical (OH• modification. Glycoxidation mediated effects on IgG were evaluated by various physicochemical techniques likeultraviolet (UV and fluorescence spectroscopy, 8-anilinonaphthalene-1-sulfonic acid (ANS binding studies, carbonyl andfree sulfhydryl groups assay, matrix assisted laser desorption ionization mass spectrometry-time of flight (MALDI-TOF, red blood cell (RBC haemolysis assay, Congored (CR staining analysis and scanning electron microscopy (SEM. The results revealed hyperchromicityin UV, advanced glycation end product (AGEspecific and ANS fluorescence, quenching in tyrosine and tryptophan fluorescence intensity,enhanced carbonyl content,reduction in free sulfhydryl groups,pronounced shift in m/z value of IgGand decrease in antioxidant activity in RBC induced haemolysis assayupon glycoxidation. SEM and CRstaining assay showed highly altered surface morphology in glycoxidised sample as compared to the native. Enzyme linked immunosorbent assay (ELISA and band shift assay were performed to assess the changes in immunogenicity of IgG upon glyoxidation and its role in T2DM. The serum antibodies derived from T2DM patients demonstrated strong affinity towards OH• treated MG glycatedIgG (OH•-MG-IgG when compared to native IgG (N-IgG or IgGs treated with MG alone (MG-IgG or OH• alone (OH•-IgG. This study shows the cumulating effect of OH• on the glycation potential of MG. The results point towards the modification of IgG in diabetes patients

  18. Industrial production and professional application of manufactured nanomaterials-enabled end products in Dutch industries: potential for exposure.

    Science.gov (United States)

    Bekker, Cindy; Brouwer, Derk H; Tielemans, Erik; Pronk, Anjoeka

    2013-04-01

    In order to make full use of the opportunities while responsibly managing the risks of working with manufactured nanomaterials (MNM), we need to gain insight into the potential level of exposure to MNM in the industry. Therefore, the goal of this study was to obtain an overview of the potential MNM exposure scenarios within relevant industrial sectors, applied exposure controls, and number of workers potentially exposed to MNM in Dutch industrial sectors producing and applying MNM-enabled end products in the Netherlands. A survey was conducted in three phases: (i) identification of MNM-enabled end products; (ii) identification of relevant industrial sectors; and (iii) a tiered telephone survey to estimate actual use of the products among 40 sector organizations/knowledge centres (Tier 1), 350 randomly selected companies (Tier 2), and 110 actively searched companies (Tier 3). The most dominant industrial sectors producing or applying MNM-enabled end products (market penetration >5%) are shoe repair shops, automotive, construction, paint, metal, and textile cleaning industry. In the majority of the companies (76%), potential risks related to working with MNM are not a specific point of interest. The total number of workers potentially exposed to MNM during the production or application of MNM-enabled end products was estimated at approximately 3000 workers in the Netherlands. The results of this study will serve as a basis for in-depth exposure and health surveys that are currently planned in the Netherlands. In addition, the results can be used to identify the most relevant sectors for policy makers and future studies focussing on evaluating the risks of occupational exposure to MNM.

  19. Effect of Thai banana (Musa AA group) in reducing accumulation of oxidation end products in UVB-irradiated mouse skin.

    Science.gov (United States)

    Leerach, Nontaphat; Yakaew, Swanya; Phimnuan, Preeyawass; Soimee, Wichuda; Nakyai, Wongnapa; Luangbudnark, Witoo; Viyoch, Jarupa

    2017-03-01

    Chronic UVB exposure causes skin disorders and cancer through DNA strand breaks and oxidation of numerous functional groups of proteins and lipids in the skin. In this study, we investigated the effects of Thai banana (Musa AA group, "Khai," and Musa ABB group, "Namwa") on the prevention of UVB-induced skin damage when fed to male ICR mice. Mice were orally fed banana (Khai or Namwa) fruit pulps at dose of 1mg/g body weight/day for 12weeks. The shaved backs of the mice were irradiated with UVB for 12weeks. The intensity dose of UVB-exposure was increased from 54mJ/cm 2 /exposure at week 1 to 126mJ/cm 2 /exposure at week 12. A significant increase in skin thickness, lipid peroxidation, protein oxidation end products, and expression of MMP-1 was observed in UVB-irradiated mouse skin. A reduction in the accumulation of oxidation end products was found in the skin of UVB-irradiated mice receiving Khai. This occurred in conjunction with a reduction in MMP-1 expression, inhibition of epidermal thickening, and induction of γ-GCS expression. The dietary intake of Khai prevented skin damage from chronic UVB exposure by increased γ-GCS expression and reduced oxidation end products included carbonyls, malondialdehyde and 4-hydroxynonenal. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Effects of thyroid status on glycated hemoglobin

    Directory of Open Access Journals (Sweden)

    Rana Bhattacharjee

    2017-01-01

    Full Text Available Introduction: Glycated hemoglobin (HbA1c can be altered in different conditions. We hypothesize that HbA1c levels may change due to altered thyroid status, possibly due to changes in red blood cell (RBC turnover. Objectives: The objective of this study was to determine the effects of altered thyroid status on HbA1c levels in individuals without diabetes, with overt hyper- and hypo-thyroidism, and if present, whether such changes in HbA1c are reversed after achieving euthyroid state. Methods: Euglycemic individuals with overt hypo- or hyper-thyroidism were selected. Age- and sex-matched controls were recruited. Baseline HbA1c and reticulocyte counts (for estimation of RBC turnover were estimated in all the patients and compared. Thereafter, stable euthyroidism was achieved in a randomly selected subgroup and HbA1c and reticulocyte count was reassessed. HbA1c values and reticulocyte counts were compared with baseline in both the groups. Results: Hb A1c in patients initially selected was found to be significantly higher in hypothyroid group. HbA1c values in hyperthyroid patients were not significantly different from controls. HbA1c reduction and rise in reticulocyte count were significant in hypothyroid group following treatment without significant change in glucose level. Hb A1c did not change significantly following treatment in hyperthyroid group. The reticulocyte count, however, decreased significantly. Conclusion: Baseline HbA1c levels were found to be significantly higher in hypothyroid patients, which reduced significantly after achievement of euthyroidism without any change in glucose levels. Significant baseline or posttreatment change was not observed in hyperthyroid patients. Our study suggests that we should be cautious while interpreting HbA1c data in patients with hypothyroidism.

  1. Inhibition of Nonenzymatic Protein Glycation by Pomegranate and Other Fruit Juices

    Science.gov (United States)

    Dorsey, Pamela Garner; Greenspan, Phillip

    2014-01-01

    Abstract The nonenzymatic glycation of proteins and the formation of advanced glycation endproducts in diabetes leads to the crosslinking of proteins and disease complications. Our study sought to demonstrate the effect of commonly consume