Methylglyoxal-Derived Hydroimidazolone Advanced Glycation End-Products of Human Lens Proteins

2003 ◽  
Vol 44 (12) ◽  
pp. 5287 ◽  
Author(s):  
Naila Ahmed ◽  
Paul J. Thornalley ◽  
Jens Dawczynski ◽  
Sybille Franke ◽  
Juergen Strobel ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Human Lens ◽  
Advanced Glycation ◽  
Lens Proteins ◽  
Glycation End Products ◽  
End Products

scholarly journals N ε-(Carboxyethyl)lysine, a product of the chemical modification of proteins by methylglyoxal, increases with age in human lens proteins

1997 ◽  
Vol 324 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahtab U. AHMED ◽  
Elisabeth BRINKMANN FRYE ◽  
Thorsten P. DEGENHARDT ◽  
Suzanne R. THORPE ◽  
John W. BAYNES
Keyword(s):  
Advanced Glycation End Products ◽  
Human Lens ◽  
Advanced Glycation ◽  
Model Compounds ◽  
Lens Proteins ◽  
Glycation End Products ◽  
End Products ◽  
Lysine Residues ◽  
Carboxymethyl Lysine ◽  
Chemical Modification Of Proteins

Advanced glycation end-products and glycoxidation products, such as Nϵ-(carboxymethyl)lysine (CML) and pentosidine, accumulate in long-lived tissue proteins with age and are implicated in the aging of tissue proteins and in the development of pathology in diabetes, atherosclerosis and other diseases. In this paper we describe a new advanced glycation end-product, Nϵ-(carboxyethyl)lysine (CEL), which is formed during the reaction of methylglyoxal with lysine residues in model compounds and in the proteins RNase and collagen. CEL was also detected in human lens proteins at a concentration similar to that of CML, and increased with age in parallel with the concentration of CML. Although CEL was formed in highest yields during the reaction of methylglyoxal and triose phosphates with lysine and protein, it was also formed in reactions of pentoses, ascorbate and other sugars with lysine and RNase. We propose that levels of CML and CEL and their ratio to one another in tissue proteins and in urine will provide an index of glyoxal and methylglyoxal concentrations in tissues, alterations in glutathione homoeostasis and dicarbonyl metabolism in disease, and sources of advanced glycation end-products in tissue proteins in aging and disease.

scholarly journals Effects of photobleaching on selected advanced glycation end products in the human lens

2015 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
Thomas Holm ◽  
Cibin T Raghavan ◽  
Rooban Nahomi ◽  
Ram H Nagaraj ◽  
Line Kessel
Keyword(s):  
Advanced Glycation End Products ◽  
Human Lens ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

scholarly journals Effect of thioltransferase on oxidative stress induced by high glucose and advanced glycation end products in human lens epithelial cells

2021 ◽  
Vol 14 (7) ◽  
pp. 965-972
Author(s):  
Qing Liu ◽  
◽  
Hong Yan ◽  
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
High Glucose ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Advanced Glycation ◽  
Human Lens Epithelial Cells ◽  
Glycation End Products ◽  
End Products

AIM: To study the effect of thioltransferase (TTase) on oxidative stress in human lens epithelial cells (HLECs) induced by high glucose and advanced glycation end products (AGEs). METHODS: HLECs were treated with 35.5 mmol/L glucose or 1.5 mg/mL AGEs modified bovine serum albumin (AGEs-BSA) as the experimental groups, respectively. Cells were collected at the time point of 1, 2, 3, and 4d. The TTase activity were measured accordingly. TTase mRNA levels were detected by quantitative reverse transcription polymerase chain response (qRT-RCR) and its protein level was detected by Western blot. The siRNA was used to knock down the expression of TTase. The activity of catalase (CAT) and superoxide dismutase (SOD), the content of reactive oxygen species (ROS) and the ratio of oxidized glutathione/total glutathione (GSSG/T-GSH) were assessed in different groups, respectively. RESULTS: The level of TTase mRNA gradually increased and reached the top at 2d, then it decreased to the normal level at 4d, and the TTase activity increased from 2 to 3d in both high glucose and AGEs-BSA groups. The TTase expression elevated from 2d in high glucose group, and it began to rise from 3d in AGEs-BSA group. The activity of CAT and SOD showed a decrease and the content of ROS and the ratio of GSSG/T-GSH showed an increase in high glucose and AGEs-BSA group. These biochemical alterations were more prominent in the groups with TTase siRNA. CONCLUSION: High glucose and AGEs can increase ROS content in HLECs; therefore, it induces oxidative stress. This may result in the decreased GSH and increased GSSG content, impaired activity of SOD and CAT. The up-regulated TTase likely provides oxidation damage repair induced by high glucose and AGEs in the early stage.

scholarly journals 3H-1,2-Dithiole-3-Thione Protects Lens Epithelial Cells against Fructose-Induced Epithelial-Mesenchymal Transition via Activation of AMPK to Eliminate AKR1B1-Induced Oxidative Stress in Diabetes Mellitus

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1086
Author(s):  
Tsung-Tien Wu ◽  
Ying-Ying Chen ◽  
Chiu-Yi Ho ◽  
Tung-Chen Yeh ◽  
Gwo-Ching Sun ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Epithelial Cells ◽  
Advanced Glycation End Products ◽  
Epithelial Mesenchymal Transition ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Advanced Glycation ◽  
Mesenchymal Transition ◽  
Glycation End Products ◽  
End Products

Studies demonstrated that the receptor of advanced glycation end products (RAGE) induced epithelial-mesenchymal transition (EMT) formation in the lens epithelial cells (LECs) of diabetic cataracts. This work investigated how 3H-1,2-dithiole-3-thione (D3T) reduces EMT formation in LECs of the fructose-induced diabetes mellitus (DM). LECs were isolated during cataract surgery from patients without DM or with DM. In a rat model, fructose (10% fructose, eight weeks) with or without D3T (10 mg/kg/day) treatment induced DM, as verified by blood pressure and serum parameter measurements. We observed that the formation of advanced glycation end products (AGEs) was significantly higher in epithelial human lens of DM (+) compared to DM (−) cataracts. Aldose reductase (AKR1B1), AcSOD2, and 3-NT were significantly enhanced in the rat lens epithelial sections of fructose-induced DM, however, the phosphorylation level of AMPKT172 showed a reversed result. Interestingly, administration of D3T reverses the fructose-induced effects in LECs. These results indicated that AMPKT172 may be required for reduced superoxide generation and the pathogenesis of diabetic cataract. Administration of D3T reverses the fructose-induced EMT formation the LECs of fructose-induced DM. These novel findings suggest that the D3T may be a candidate for the pharmacological prevention of cataracts in patients with DM.

scholarly journals UVA Light-excited Kynurenines Oxidize Ascorbate and Modify Lens Proteins through the Formation of Advanced Glycation End Products

2014 ◽  
Vol 289 (24) ◽  
pp. 17111-17123 ◽  
Author(s):  
Mikhail Linetsky ◽  
Cibin T. Raghavan ◽  
Kaid Johar ◽  
Xingjun Fan ◽  
Vincent M. Monnier ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Advanced Glycation ◽  
Lens Proteins ◽  
Glycation End Products ◽  
End Products ◽  
Uva Light
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