China
Africa
Explore chapters and articles related to this topic
Postimplantation diabetic embryopathy
Published in Moshe Hod, Lois G. Jovanovic, Gian Carlo Di Renzo, Alberto de Leiva, Oded Langer, Textbook of Diabetes and Pregnancy, 2018
Ulf J. Eriksson, Parri Wentzel
It has also been suggested that AGE–RAGE activation is involved in diabetic embryopathy. Thus, the embryonic formation of glycated proteins96,272,273 has been suggested to influence the teratological events in diabetic pregnancy. It has been shown in rodent embryos cultured in high glucose that the levels of the AGE precursor 3-Deoxyglucosone (3-DG) increase in embryonic tissue, and the addition of 3-DG to the culture medium with physiologic concentrations of glucose induces malformations, an effect that is reversible with the addition of SOD.96
Advanced Glycation Endproducts
Published in Sara C. Zapico, Mechanisms Linking Aging, Diseases and Biological Age Estimation, 2017
Andreas Simm, Alexander Navarrete Santos
Important acceptors of the sugars are amino acids like lysine or arginine or amino groups on nucleobases and lipids. Besides monosaccharides, small α-oxocarbonylic compounds (especially dicarbonyls) contribute significantly to AGE formation as they are far more reactive than sugars (Lo et al. 1994, Thornalley 2007). High levels of these reactive compounds such as 3-deoxyglucosone, glyoxal or methylglyoxal induces the so-called “carbonyl stress”. Different reactions lead to the formation of dicarbonyls, from a byproduct of the glycolysis (methylglyoxal) to a product of lipid peroxidation (glyoxal). Depending on the amino acid sequence of the proteins, specific amino acids can be modified by sugars, resulting in some kind of unexpected specificity (Munch et al. 1999).
Marine Algae in Diabetes and Its Complications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Proteins or lipids are modified by glycosylation non-enzymatically in hyperglycemia to form AGEs and are subsequently oxidized. Schiff bases and Amadori products are formed due to early oxidation and glycation processes. Persistent glycation leads to molecular rearrangements that aids in AGE formation (Schmidt et al., 1994). Glycated products generate reactive oxygen species (ROS), engage receptors on the cell surface, and cross-link them. Important factors critical to AGE formation incorporate the rate of turnover of proteins for glycoxidation, the extent of hyperglycemia, and oxidative stress in the milieu (Figure 2.1). If these conditions prevail, glycation and oxidation of both intracellular and extracellular proteins are certain. The AGE formation (by the Maillard reaction) happens due to the reaction between Schiff bases and Amadori product with the -NH2 moieties of biomolecules (Giovino et al., 2020). During Amadori reorganization, these intermediary carbonyl groups that are highly reactive accumulate and are known as α-dicarbonyls or oxoaldehyde. These are the products of 3-deoxyglucosone and methylglyoxal. Such accumulation is called “carbonyl stress”. The α-dicarbonyls react with -SH, -NH2, and guanidine functional groups resulting in browning, cross-linking, and denaturation of the target proteins. They also react with arginine and lysine to form stable, non-fluorescent AGE products such as N-α-(carboxymethyl)lysine (CML). Protein glycation increases free radical activity that brings forth bimolecular damage in diabetes. AGEs act as initiators of a lot of abnormal cellular and tissue responses, such as the illicit expression of growth factors, extracellular matrix accumulation, and induction of cell death (Suzuki et al., 1999).[
Biomarkers of disease in human nails: a comprehensive review
Published in Critical Reviews in Clinical Laboratory Sciences, 2022
Sarahi Jaramillo Ortiz, Michael Howsam, Elisabeth H. van Aken, Joris R. Delanghe, Eric Boulanger, Frédéric J. Tessier
Min et al. [32] studied three dicarbonyl AGE intermediates in a small (n = 20) case-control study of diabetic patients, reporting that ungual 3-deoxyglucosone (3-DG) was a potential diagnostic biomarker for diabetes but that there was no difference in methylglyoxal or glyoxal concentrations between cases and controls. Despite the small population sizes, their study covered a relatively broad age range (30–69 years old) and has the merit of including a rigorous characterization of their liquid chromatography-mass spectrometry (LC-MS) method. Earlier work by the same research group studied free amino acids in nails in a series of small case-control studies of diabetes and cancer (see Section 2). Derivatized, free L- and D-amino acids were analyzed in nails by HPLC with time-of-flight (TOF) MS detection [33], and 20 diabetic cases were compared with 20 controls [34]. They reported a significant correlation among cases for the ungual D: L enantiomer ratios of alanine, valine, isoleucine, and leucine that was absent in controls but did not propose a mechanism for why this difference occurred.
3-Deoxyglucosone reduces glucagon-like peptide-1 secretion at low glucose levels through down-regulation of SGLT1 expression in STC-1 cells
Published in Archives of Physiology and Biochemistry, 2021
Liang Zhou, Fei Wang, Xiudao Song, Min Shi, Guoqiang Liang, Lurong Zhang, Fei Huang, Guorong Jiang
Reactive 1,2-dicarbonyl compounds are generated from carbohydrates during food processing and storage and under physiological conditions (Niwa 1999, Degen et al.2012). Formation and degradation reactions of 1,2-dicarbonyl compounds that participate in colour and aroma form are closely connected to the palatability of food. One of the most abundant 1,2-dicarbonyl compounds in food is 3-deoxyglucosone (3DG) (Degen et al.2012). High 3DG contents were measured in fruit juices (up to 410 mg/l), balsamic vinegar (up to 2622 mg/l), honey (10 mmol/kg), and bakery products such as cookies (up to 385 mg/kg) (Degen et al.2012). Accumulating evidence has indicated that dietary 3DG is an independent factor associated with the development of pre-diabetes (Jiang et al.2012, Liang et al.2016a, Zhang et al.2016, Wang et al.2017). An earlier study with a single oral administration of 3DG has indicated that the absorption rate of 3DG from foodstuffs is very slow (Kato et al.1990). We have recently shown that the intestine might be its novel target tissue (Zhang et al.2016, Wang et al.2017). 3DG-mediated inhibition of GLP-1 secretion is a mechanism linking 3DG with the dysregulation of glucose homeostasis (Zhang et al.2016, Wang et al.2017). Using mouse enteroendocrine cell line STC-1, we previously also have assessed the harmful effect of 3DG on GLP-1 secretion induced by the relatively high concentration of glucose (25 mM) (Wang et al.2018). In this study, we investigated whether (1) 3DG directly reduces GLP-1 secretion from STC-1 cells under low-glucose conditions and (2) if so we examine the effect of 3DG on the SGLT1 pathway under low-glucose conditions in STC-1 cells.
Ameliorative Influence of Dietary Fenugreek (Trigonella foenum-graecum) Seeds and Onion (Allium cepa) on Eye Lens Abnormalities via Modulation of Crystallin Proteins and Polyol Pathway in Experimental Diabetes
Published in Current Eye Research, 2018
Seetur R. Pradeep, Krishnapura Srinivasan
Sorbitol accumulation produces osmotic stress in cells by drawing water into the tissue. Sorbitol may also glycate proteins leading to the formation of AGEs. SDH, which is usually low in this tissue under normal condition, got upregulated in the face of increased sorbitol concentration, which in turn oxidizes sorbitol to fructose using NAD+ as co-factor. NAD+ is converted to NADH, which is the substrate for NADH oxidase that generates ROS.45 Fructose, which is further enzymatically phosphorylated to fructose-3-phosphate, and subsequently degraded to 3-deoxyglucosone, is a more potent non-enzymatic glycation agent than glucose. Thus, the flux of glucose through the polyol pathway would increase AGEs and binds to the receptor (RAGE) on cells, ultimately leading to ROS generation.46 Our results showed that hyperglycemia-induced polyol pathway was significantly higher in diabetic lens. However, diabetic rats fed with fenugreek, onion, and fenugreek + onion significantly inhibited the activity of AR, SDH, and accumulations of its metabolites in the eye lens. This is corroborated by the absence of lenticular opacity and mature cataract in rats fed with these dietary interventions. This study also observed that the increased formation of AGEs and upregulated expression of RAGE was beneficially countered by these dietary interventions with increased tryptophan fluorescence spectra in diabetic lens, the effect being higher with combination of fenugreek + onion feeding. The decreased tryptophan fluorescence in diabetic lenses is a result of high level of tryptophan oxidation and glycation. Additionally, since the diabetic lenses also accumulate fluorophores that can be exited in 340–400 nm range, the tryptophan emission can decrease in 330–350 nm range, which can result in an apparent decrease in tryptophan concentration measured using fluorescence emission.