scholarly journals Assay of advanced glycation endproducts (AGEs): surveying AGEs by chromatographic assay with derivatization by 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate and application to N∊-carboxymethyl-lysine- and N∊-(1-carboxyethyl)lysine-modified albumin

2002 ◽  
Vol 364 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Naila AHMED ◽  
Ognian K. ARGIROV ◽  
Harjit S. MINHAS ◽  
Carlos A.A. CORDEIRO ◽  
Paul J. THORNALLEY
Keyword(s):  
Advanced Glycation Endproducts ◽  
Advanced Glycation ◽  
Structural Isomers ◽  
Glycation Endproducts ◽  
Assay Procedure ◽  
Carboxymethyl Lysine ◽  
Glycation Process ◽  
First Time ◽  
Hydrolysis Of

Glycation of proteins leads to the formation of early glycation adducts (fructosamine derivatives) and advanced glycation endproducts (AGEs). Formation of AGEs has been linked to the development of cataract, diabetic complications, uraemia, Alzheimer's disease and other disorders. AGEs are a group of compounds of diverse molecular structure and biological function. To characterize AGE-modified proteins used in studies of structural and functional effects of glycation, an assay was developed that surveys the content of early and advanced glycation adducts in proteins. The assay procedure involved enzymic hydrolysis of protein substrate, derivatization of the hydrolysate with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) and HPLC of the resulting adducts with fluorimetric detection. Structural isomers of methylglyoxal-derived hydroimidazolone, glyoxal-derived hydroimidazolone, 3-deoxyglucosone-derived hydroimidazolone and Nδ-(4-carboxy-4,6-dimethyl-5,6-dihydroxy-1,4,5,6-tetrahydropyrimidin-2-yl)-ornithine (THP) were determined for the first time. AGEs with intrinsic fluorescence (argpyrimidine, pentosidine) were assayed without derivatization. Limits of detection were 2–17pmol and levels of recovery were 50–99%, depending on the analyte. The AQC assay resolved structural and epimeric isomers of methylglyoxal-derived hydroimidazolones and THP. Hydroimidazolones, THP and argpyrimidine were AGEs of short-to-intermediate stability under physiological conditions, with half-lives of 1–2weeks. Their measurement provides further insight into the glycation process. The assay was applied to the characterization of human serum albumin minimally and highly modified by N∊-carboxymethyl-lysine and N∊-(1-carboxyethyl)-lysine.

scholarly journals Serum advanced glycation endproducts are associated with left ventricular dysfunction in normal glucose metabolism but not in type 2 diabetes: The Hoorn Study

2016 ◽  
Vol 13 (4) ◽  
pp. 278-285 ◽  
Author(s):  
Pauline BC Linssen ◽  
Ronald MA Henry ◽  
Casper G Schalkwijk ◽  
Jacqueline M Dekker ◽  
Giel Nijpels ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Glucose Metabolism ◽  
Advanced Glycation Endproducts ◽  
Left Ventricular ◽  
Advanced Glycation ◽  
Glycation Endproducts ◽  
Normal Glucose ◽  
Carboxymethyl Lysine

Objective: To investigate whether serum advanced glycation endproducts are associated with left ventricular systolic and diastolic function in participants with normal glucose metabolism, impaired glucose metabolism and type 2 diabetes mellitus. Methods: Participants from a cross-sectional, population-based study ( n = 280 with normal glucose metabolism, n = 171 with impaired glucose metabolism, n = 242 with type 2 diabetes mellitus) underwent echocardiography. Serum protein-bound advanced glycation endproducts [i.e. Nε-(carboxymethyl)lysine, pentosidine and Nε-(carboxyethyl)lysine] were measured. Linear regression analyses were used and stratified according to glucose metabolism status. Results: In normal glucose metabolism, higher Nε-(carboxymethyl)lysine and pentosidine levels were associated with worse diastolic function (left atrial volume index and left atrial volume × left ventricular mass index product term) and higher Nε-(carboxymethyl)lysine and Nε-(carboxyethyl)lysine levels with worse systolic function (ejection fraction). In impaired glucose metabolism, a similar pattern emerged, though less consistent. In type 2 diabetes mellitus, these associations were non-existent for diastolic function or even reversed for systolic function. Conclusion: This suggests that serum advanced glycation endproducts are associated with impaired left ventricular function in normal glucose metabolism, but that with deteriorating glucose metabolism status, serum advanced glycation endproducts may not mirror heart failure risk.

scholarly journals Dihydromyricetin as a Functional Additive to Enhance Antioxidant Capacity and Inhibit the Formation of Thermally Induced Food Toxicants in a Cookie Model

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2184 ◽  
Author(s):  
Jing Teng ◽  
Xuduo Liu ◽  
Xiaoqian Hu ◽  
Yueliang Zhao ◽  
Ning-Ping Tao ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Advanced Glycation Endproducts ◽  
Advanced Glycation ◽  
Thermally Induced ◽  
Glycation Endproducts ◽  
Functional Additive ◽  
Lipid And Protein Oxidation ◽  
Carboxymethyl Lysine ◽  
Chia Oil ◽  
Food Toxicants

Recently, there is a growing interest in fortifying food products with flavonoids to enhance health benefits. Naringenin, naringin, hesperetin, and dihydromyricetin are four typical flavonoids constituting a natural part of our diet. In the present work, they were fortified into a chia oil cookie model to evaluate their thermal stability during baking as well as their impact on antioxidant capacity and toxicant formation. Among them dihydromyricetin was the most unstable one (only 36.1% of which was left after baking at 180 °C for 20 min) and led to a loss of brightness in cookie. However, the antioxidant capacity of cookie fortified with dihydromyricetin was significantly enhanced compared with untreated cookie; on the other hand, dihydromyricetin showed the strongest effect to attenuate lipid and protein oxidation as well as decrease the level of fluorescent advanced glycation endproducts and carboxymethyl lysine in cookie model. Overall, among the four selected flavonoids, dihydromyricetin might be the most promising functional bakery additive enhancing the antioxidant capacity while decreasing the formation of toxicants.

Pomegranate phenolics inhibit formation of advanced glycation endproducts by scavenging reactive carbonyl species

2014 ◽  
Vol 5 (11) ◽  
pp. 2996-3004 ◽  
Author(s):  
Weixi Liu ◽  
Hang Ma ◽  
Leslie Frost ◽  
Tao Yuan ◽  
Joel A. Dain ◽  
...  
Keyword(s):  
Advanced Glycation Endproducts ◽  
Inhibitory Effects ◽  
Advanced Glycation ◽  
Glycation Endproducts ◽  
Reactive Carbonyl Species ◽  
First Time ◽  
Carbonyl Species ◽  
Reactive Carbonyl

The present study reported for the first time the inhibitory effects of pomegranate phenolics on the formation of advanced glycation endproducts and their carbonyl scavenger reactivity.

scholarly journals Chromatographic assay of glycation adducts in human serum albumin glycated in vitro by derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate and intrinsic fluorescence

2002 ◽  
Vol 364 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Naila AHMED ◽  
Paul J. THORNALLEY
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Advanced Glycation Endproducts ◽  
Intrinsic Fluorescence ◽  
Advanced Glycation ◽  
Glycation Endproducts ◽  
Carboxymethyl Lysine ◽  
Cross Links

Glycation of proteins leads to the formation of advanced glycation endproducts (AGEs) of diverse molecular structure and biological function. Serum albumin derivatives modified to minimal and high extents by methylglyoxal and glucose in vitro have been used in many studies as model AGE proteins. The early and advanced glycation adduct contents of these proteins were investigated using the 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate (AQC) chromatographic assay of enzymic hydrolysates. AGEs derived from methylglyoxal, glyoxal and 3-deoxyglucosone, the hydroimidazolones Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1), Nδ-(5-hydro-4-imidazolon-2-yl)ornithine (G-H1) and Nδ-[5-(2,3,4-trihydroxybutyl)-5-hydro-4-imidazolon-2-yl]ornithine (3DG-H1), bis(lysyl)imidazolium cross-links methylglyoxal-derived lysine dimer (MOLD), glyoxal-derived lysine dimer (GOLD), 3-deoxyglucosone-derived lysine dimer (DOLD), monolysyl adducts N∊-(1-carboxyethyl)lysine (CEL), N∊-carboxymethyl-lysine (CML) and pyrraline, other AGEs, Nδ-(4-carboxy-4,6-dimethyl-5,6-dihydroxy-1,4,5,6-tetrahydropyrimidin-2-yl)ornithine (THP), argpyrimidine and pentosidine, and fructosyl-lysine were determined. AGEs with intrinsic fluorescence (argpyrimidine and pentosidine) were assayed without derivatization. Human serum albumin (HSA) glycated minimally by methylglyoxal in vitro contained mainly MG-H1 with minor amounts of THP and argpyrimidine. Similar AGEs were found in prothrombin glycated minimally by methylglyoxal and in Nα-t-butyloxycarbonyl-arginine incubated with methylglyoxal. HSA glycated highly by methylglyoxal contained mainly argpyrimidine, MG-H1 and THP, with minor amounts of CEL and MOLD. HSA glycated minimally by glucose in vitro contained mainly fructosyl-lysine and CML, with minor amounts of THP, MG-H1, G-H1, 3DG-H1, argpyrimidine and DOLD. HSA glycated highly by glucose contained these AGEs and pyrraline, and very high amounts (≈8mol/mol of protein) of fructosyl-lysine. Most AGEs in albumin glycated minimally by methylglyoxal and glucose were identified. Significant proportions of arginine and lysine-derived AGEs in albumin modified highly by methylglyoxal, and lysine-derived AGEs in albumin modified highly by glucose, remain to be identified.

scholarly journals The Immune Tolerance Role of the HMGB1-RAGE Axis

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 564
Author(s):  
Haruki Watanabe ◽  
Myoungsun Son
Keyword(s):  
Immune Responses ◽  
Immune Tolerance ◽  
Lupus Erythematosus ◽  
Advanced Glycation Endproducts ◽  
High Mobility ◽  
Chromatin Binding ◽  
Advanced Glycation ◽  
Glycation Endproducts ◽  
Extracellular Milieu

The disruption of the immune tolerance induces autoimmunity such as systemic lupus erythematosus and vasculitis. A chromatin-binding non-histone protein, high mobility group box 1 (HMGB1), is released from the nucleus to the extracellular milieu in particular environments such as autoimmunity, sepsis and hypoxia. Extracellular HMGB1 engages pattern recognition receptors, including Toll-like receptors (TLRs) and the receptor for advanced glycation endproducts (RAGE). While the HMGB1-RAGE axis drives inflammation in various diseases, recent studies also focus on the anti-inflammatory effects of HMGB1 and RAGE. This review discusses current perspectives on HMGB1 and RAGE’s roles in controlling inflammation and immune tolerance. We also suggest how RAGE heterodimers responding microenvironments functions in immune responses.

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