scholarly journals Impact of Androgen and Dietary Advanced Glycation End Products on Female Rat Liver

2015 ◽  
Vol 37 (3) ◽  
pp. 1134-1146 ◽  
Author(s):  
Eleni Palioura ◽  
Sotiria Palimeri ◽  
Christina Piperi ◽  
Stratigoula Sakellariou ◽  
Eleni Kandaraki ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Polycystic Ovary ◽  
Gamma Glutamyl Transferase ◽  
Female Rat ◽  
Advanced Glycation ◽  
Wide Range ◽  
Glycation End Products ◽  
End Products ◽  
High Age ◽  
Glutamyl Transferase

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 (p<0.01) when compared to the respective low-AGE group, while aspartate aminotransferase (AST) levels were affected only in non-androgenized animals (p=0.0002). Androgenization per 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.

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

2008 ◽  
Vol 67 (1) ◽  
pp. 60-74 ◽  
Author(s):  
Kateřina Kaňková
Keyword(s):  
Advanced Glycation End Products ◽  
Biological Properties ◽  
Advanced Glycation ◽  
Similar Chemical ◽  
Wide Range ◽  
Glycation End Products ◽  
End Products ◽  
Genes Encoding ◽  
Sugar Derivatives

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, α-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.

Increased levels of serum advanced glycation end-products in women with polycystic ovary syndrome

2005 ◽  
Vol 62 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Evanthia Diamanti-Kandarakis ◽  
Christina Piperi ◽  
Anastasios Kalofoutis ◽  
George Creatsas
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Advanced Glycation End Products ◽  
Polycystic Ovary ◽  
Advanced Glycation ◽  
Ovary Syndrome ◽  
Glycation End Products ◽  
End Products

scholarly journals Complementarity of Raman and Infrared Spectroscopy for Rapid Characterization of Fucoidan Extracts

2020 ◽  
Author(s):  
Signe Ptak ◽  
Lee Sanchez ◽  
Xavier Frette ◽  
Dmitry Kurouski
Keyword(s):  
Infrared Spectroscopy ◽  
Advanced Glycation End Products ◽  
Rapid Screening ◽  
Sulfated Polysaccharides ◽  
Advanced Glycation ◽  
Wide Range ◽  
Glycation End Products ◽  
End Products ◽  
Raman And Infrared Spectroscopy

Abstract BackgroundFucoidans are sulfated polysaccharides from the cell-wall of brown algae. They have a wide range of applications in medicine, including regenerative medicine, ophthalmology, cancer, and autoimmune disease. Biological activity of fucoidans directly depends on their structure, which remains poorly understood. This is primarily because the polymeric nature of these molecules limits the use of nuclear magnetic resonance and mass spectrometry, classical tools of structural biology for their structural characterization. Raman and Infrared spectroscopies are non-invasive and non-destructive techniques that can be used to probe the structural organization of biological specimens. In this study, we investigate the potential of Raman and Infrared spectroscopy for structural analysis of several fucoidan extracts. ResultsOur results show that Infrared and Raman provide different but complimentary information about the structure of crude extracts of fucoidans, revealing the presence of minor impurities from co-extractants. We also found that at high extraction temperatures acidic conditions limit formation of melanoidins, while also yielding relatively high sulfate ester fucoidan. However, at high temperatures, water extraction may potentially result in formation of advanced glycation end products. Their presence could be problematic for fucoidan extracts intended for medicinal use, as advanced glycation end products have been linked to endocrine interruption mechanisms in vivo by crosslinking to and permanently altering extracellular matrix proteins. ConclusionRaman and Infrared can be used as complementary tools for rapid screening of crude fucoidan extracts, which can be a valuable tool for assessing impurities that remain after extraction.

scholarly journals Contribution of dietary advanced glycation end products (AGE) to circulating AGE: role of dietary fat

2015 ◽  
Vol 114 (11) ◽  
pp. 1797-1806 ◽  
Author(s):  
Kathleen E. Davis ◽  
Chandan Prasad ◽  
Parakat Vijayagopal ◽  
Shanil Juma ◽  
Beverley Adams-Huet ◽  
...  
Keyword(s):  
Advanced Glycation End Products ◽  
Test Meal ◽  
Dietary Factors ◽  
High Fat ◽  
Advanced Glycation ◽  
Low Fat ◽  
High Molecular Weight Adiponectin ◽  
Glycation End Products ◽  
End Products ◽  
High Age

AbstractThe purpose of this pilot study was to determine whether macronutrient content (low-fat v. high-fat diet) influences an indicator of advanced glycation end products (AGE), Nε carboxymethyl-lysine (CML), in the context of a 1-d, high-AGE diet. The effect of the diets on inflammatory markers was also assessed. A total of nineteen overweight and obese adults (nine men and ten women) without known disease were recruited to participate in a crossover challenge of a high-fat, high-AGE (HFHA) and low-fat, high-AGE (LFHA) diet. In each phase patients had fasting blood drawn, followed by consumption of a high-fat or low-fat breakfast test meal, then three postprandial blood draws at 1, 2 and 3 h after consuming the test meal. After consuming high-AGE meals for the remainder of the day, participants returned the next day for a follow-up analysis. A different pattern in the 3-h post-meal CML and soluble receptor for AGE response to the two diets was observed (P=0·01 and 0·05, respectively). No change in serum CML was observed following consumption of a LFHA breakfast (535 (25th–75th percentile 451–790) to 495 (25th–75th percentile 391–682) ng/ml; P=0·36), whereas a rise in CML occurred after the HFHA breakfast (463 (25th–75th percentile 428–664) to 578 (25th–75th percentile 474–865) ng/ml; P=0·05). High sensitivity C-reactive protein and high molecular weight adiponectin were not affected by either diet. These findings suggest that dietary CML may not be as important in influencing serum CML as other dietary factors. In addition, acute exposure to dietary CML may not influence inflammation in adults without diabetes or kidney disease. This is contrary to previous findings.

Increased serum advanced glycation end-products is a distinct finding in lean women with polycystic ovary syndrome (PCOS)

2008 ◽  
Vol 69 (4) ◽  
pp. 634-641 ◽  
Author(s):  
Evanthia Diamanti-Kandarakis ◽  
Ilias Katsikis ◽  
Christina Piperi ◽  
Eleni Kandaraki ◽  
Athanasia Piouka ◽  
...  
Keyword(s):  
Polycystic Ovary Syndrome ◽  
Advanced Glycation End Products ◽  
Polycystic Ovary ◽  
Advanced Glycation ◽  
Ovary Syndrome ◽  
Glycation End Products ◽  
End Products

Androgens Increase Accumulation of Advanced Glycation End Products in Granulosa Cells by Activating ER Stress in PCOS

Endocrinology ◽  
2020 ◽  
Vol 161 (2) ◽  
Author(s):  
Jerilee M K Azhary ◽  
Miyuki Harada ◽  
Chisato Kunitomi ◽  
Akari Kusamoto ◽  
Nozomi Takahashi ◽  
...  
Keyword(s):  
Er Stress ◽  
Advanced Glycation End Products ◽  
Granulosa Cells ◽  
Polycystic Ovary ◽  
Advanced Glycation ◽  
Novel Approach ◽  
Glycation End Products ◽  
End Products ◽  
Factor C ◽  
Rage Expression

Abstract Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism, and we previously found that androgens activate endoplasmic reticulum (ER) stress in granulosa cells from patients with PCOS. In addition, recent studies demonstrated the accumulation of advanced glycation end products (AGEs) in granulosa cells from PCOS patients, which contribute to the pathology. Therefore, we hypothesized that androgens upregulate the receptor for AGEs (RAGE) expression in granulosa cells by activating ER stress, thereby increasing the accumulation of AGEs in these cells and contributing to the pathology. In the present study, we show that testosterone increases RAGE expression and AGE accumulation in cultured human granulosa-lutein cells (GLCs), and this is reduced by pretreatment with tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor in clinical use. Knockdown of the transcription factor C/EBP homologous protein (CHOP), an unfolded protein response factor activated by ER stress, inhibits testosterone-induced RAGE expression and AGE accumulation. The expression of RAGE and the accumulation of AGEs are upregulated in granulosa cells from PCOS patients and dehydroepiandrosterone-induced PCOS mice. Administration of the RAGE inhibitor FPS-ZM1 or TUDCA to PCOS mice reduces RAGE expression and AGE accumulation in granulosa cells, improves their estrous cycle, and reduces the number of atretic antral follicles. In summary, our findings indicate that hyperandrogenism in PCOS increases the expression of RAGE and accumulation of AGEs in the ovary by activating ER stress, and that targeting the AGE-RAGE system, either by using a RAGE inhibitor or a clinically available ER stress inhibitor, may represent a novel approach to PCOS therapy.

scholarly journals Vitamin D Increases Serum Levels of the Soluble Receptor for Advanced Glycation End Products in Women With PCOS

2014 ◽  
Vol 99 (5) ◽  
pp. E886-E890 ◽  
Author(s):  
Mohamad Irani ◽  
Howard Minkoff ◽  
David B. Seifer ◽  
Zaher Merhi
Keyword(s):  
Vitamin D ◽  
Advanced Glycation End Products ◽  
Vascular System ◽  
Polycystic Ovary ◽  
Treated Group ◽  
Vitamin D Supplementation ◽  
Soluble Receptor ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products

Context: Elevation of serum proinflammatory advanced glycation end products (AGEs) is involved in the pathogenesis of polycystic ovary syndrome (PCOS). The soluble receptor for AGEs (sRAGE) acts as a decoy by binding circulating AGEs. Vitamin D supplementation attenuates the deposition of AGEs in the vascular system of diabetic animals and improves some metabolic aspects of vitamin D-deficient women with PCOS. Additionally, serum anti-Mullerian hormone (AMH) is elevated in women with PCOS, reflecting abnormal ovarian folliculogenesis. Objective: The objective of the study was to evaluate the effect of 1,25 dihydroxyvitamin D3 (vit D3) supplementation on serum sRAGE and AMH in vitamin D-deficient women with PCOS. Design, Settings, Participants, and Intervention: Sixty-seven women with (n = 22) or without (control; n = 45) PCOS who were diagnosed with vitamin D deficiency were enrolled. Fifty-one women were replaced with oral vit D3 for 8 weeks (16 with PCOS and 35 controls) and 16 women were not treated (six with PCOS and 10 controls). Serum 25-hydroxyvitamin D (25 OH-D), sRAGE, and AMH concentrations were measured at baseline and after vit D3 supplementation in the treated group and 8 weeks apart in the nontreated group. Main Outcome Measure(s): Changes in serum sRAGE and AMH concentrations after vit D3 replacement were measured. Results: In all participants, there was a negative correlation between body mass index and serum sRAGE levels (r = −0.3, P = .01). In women with PCOS, but not in controls, vit D3 increased serum sRAGE (P = .03) and decreased serum AMH levels (P &lt; .001). The increase in serum sRAGE positively correlated with the increase in serum 25 OH-D after supplementation in women with PCOS (r = 0.6, P = .01). Conclusion: In women with PCOS, vit D3 might exert a protective effect against the inflammatory action of AGEs by increasing circulating sRAGE. The normalization in serum AMH induced by vit D3 replacement suggests an improvement in folliculogenesis.

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