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Mengstie MA, Chekol Abebe E, Behaile Teklemariam A, Tilahun Mulu A, Agidew MM, Teshome Azezew M, Zewde EA, Agegnehu Teshome A. Endogenous advanced glycation end products in the pathogenesis of chronic diabetic complications. Front Mol Biosci 2022; 9:1002710. [PMID: 36188225 PMCID: PMC9521189 DOI: 10.3389/fmolb.2022.1002710] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/01/2022] [Indexed: 12/22/2022] Open
Abstract
Diabetes is a common metabolic illness characterized by hyperglycemia and is linked to long-term vascular problems that can impair the kidney, eyes, nerves, and blood vessels. By increasing protein glycation and gradually accumulating advanced glycation end products in the tissues, hyperglycemia plays a significant role in the pathogenesis of diabetic complications. Advanced glycation end products are heterogeneous molecules generated from non-enzymatic interactions of sugars with proteins, lipids, or nucleic acids via the glycation process. Protein glycation and the buildup of advanced glycation end products are important in the etiology of diabetes sequelae such as retinopathy, nephropathy, neuropathy, and atherosclerosis. Their contribution to diabetes complications occurs via a receptor-mediated signaling cascade or direct extracellular matrix destruction. According to recent research, the interaction of advanced glycation end products with their transmembrane receptor results in intracellular signaling, gene expression, the release of pro-inflammatory molecules, and the production of free radicals, all of which contribute to the pathology of diabetes complications. The primary aim of this paper was to discuss the chemical reactions and formation of advanced glycation end products, the interaction of advanced glycation end products with their receptor and downstream signaling cascade, and molecular mechanisms triggered by advanced glycation end products in the pathogenesis of both micro and macrovascular complications of diabetes mellitus.
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Affiliation(s)
- Misganaw Asmamaw Mengstie
- Department of Biochemistry, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
- *Correspondence: Misganaw Asmamaw Mengstie,
| | - Endeshaw Chekol Abebe
- Department of Biochemistry, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Awgichew Behaile Teklemariam
- Department of Biochemistry, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Anemut Tilahun Mulu
- Department of Biochemistry, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Melaku Mekonnen Agidew
- Department of Biochemistry, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Muluken Teshome Azezew
- Department of Physiology, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Edgeit Abebe Zewde
- Department of Physiology, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Assefa Agegnehu Teshome
- Department of Anatomy, College of Medicine and Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
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Dicarbonyl-Dependent Modification of LDL as a Key Factor of Endothelial Dysfunction and Atherosclerotic Vascular Wall Damage. Antioxidants (Basel) 2022; 11:antiox11081565. [PMID: 36009284 PMCID: PMC9405452 DOI: 10.3390/antiox11081565] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/02/2022] [Accepted: 08/10/2022] [Indexed: 12/05/2022] Open
Abstract
The review presents evidence that the main damage to the vascular wall occurs not from the action of “oxidized” LDL, which contain hydroperoxy acyls in the phospholipids located in their outer layer, but from the action of LDL particles whose apoprotein B-100 is chemically modified with low molecular weight dicarbonyls, such as malondialdehyde, glyoxal, and methylglyoxal. It has been argued that dicarbonyl-modified LDL, which have the highest cholesterol content, are particularly “atherogenic”. High levels of dicarbonyl-modified LDL have been found to be characteristic of some mutations of apoprotein B-100. Based on the reviewed data, we hypothesized a common molecular mechanism underlying vascular wall damage in atherosclerosis and diabetes mellitus. The important role of oxidatively modified LDL in endothelial dysfunction is discussed in detail. In particular, the role of the interaction of the endothelial receptor LOX-1 with oxidatively modified LDL, which leads to the expression of NADPH oxidase, which in turn generates superoxide anion radical, is discussed. Such hyperproduction of ROS can cause destruction of the glycocalyx, a protective layer of endotheliocytes, and stimulation of apoptosis in these cells. On the whole, the accumulated evidence suggests that carbonyl modification of apoprotein B-100 of LDL is a key factor responsible for vascular wall damage leading to atherogenesis and endothelial dysfunction. Possible ways of pharmacological correction of free radical processes in atherogenesis and diabetogenesis are also discussed.
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Smith S, Normahani P, Lane T, Hohenschurz-Schmidt D, Oliver N, Davies AH. Pathogenesis of Distal Symmetrical Polyneuropathy in Diabetes. LIFE (BASEL, SWITZERLAND) 2022; 12:life12071074. [PMID: 35888162 PMCID: PMC9319251 DOI: 10.3390/life12071074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/13/2022]
Abstract
Distal symmetrical polyneuropathy (DSPN) is a serious complication of diabetes associated with significant disability and mortality. Although more than 50% of people with diabetes develop DSPN, its pathogenesis is still relatively unknown. This lack of understanding has limited the development of novel disease-modifying therapies and left the reasons for failed therapies uncertain, which is critical given that current management strategies often fail to achieve long-term efficacy. In this article, the pathogenesis of DSPN is reviewed, covering pathogenic changes in the peripheral nervous system, microvasculature and central nervous system (CNS). Furthermore, the successes and limitations of current therapies are discussed, and potential therapeutic targets are proposed. Recent findings on its pathogenesis have called the definition of DSPN into question and transformed the disease model, paving the way for new research prospects.
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Affiliation(s)
- Sasha Smith
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Pasha Normahani
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Tristan Lane
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Department of Vascular Surgery, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - David Hohenschurz-Schmidt
- Pain Research Group, Department of Surgery and Cancer, Imperial College London, London SW10 9NH, UK;
| | - Nick Oliver
- Section of Metabolic Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London W2 1PG, UK;
- Division of Medicine and Integrated Care, Imperial College Healthcare NHS Trust, London W2 1NY, UK
| | - Alun Huw Davies
- Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London W6 8RF, UK; (S.S.); (P.N.); (T.L.)
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London W6 8RF, UK
- Correspondence:
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Jayakody LN, Jin YS. In-depth understanding of molecular mechanisms of aldehyde toxicity to engineer robust Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2021; 105:2675-2692. [PMID: 33743026 DOI: 10.1007/s00253-021-11213-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/17/2021] [Accepted: 02/28/2021] [Indexed: 11/25/2022]
Abstract
Aldehydes are ubiquitous electrophilic compounds that ferment microorganisms including Saccharomyces cerevisiae encounter during the fermentation processes to produce food, fuels, chemicals, and pharmaceuticals. Aldehydes pose severe toxicity to the growth and metabolism of the S. cerevisiae through a variety of toxic molecular mechanisms, predominantly via damaging macromolecules and hampering the production of targeted compounds. Compounds with aldehyde functional groups are far more toxic to S. cerevisiae than all other functional classes, and toxic potency depends on physicochemical characteristics of aldehydes. The yeast synthetic biology community established a design-build-test-learn framework to develop S. cerevisiae cell factories to valorize the sustainable and renewable biomass, including the lignin-derived substrates. However, thermochemically pretreated biomass-derived substrate streams contain diverse aldehydes (e.g., glycolaldehyde and furfural), and biological conversions routes of lignocellulosic compounds consist of toxic aldehyde intermediates (e.g., formaldehyde and methylglyoxal), and some of the high-value targeted products have aldehyde functional group (e.g., vanillin and benzaldehyde). Numerous studies comprehensively characterized both single and additive effects of aldehyde toxicity via systems biology investigations, and novel molecular approaches have been discovered to overcome the aldehyde toxicity. Based on those novel approaches, researchers successfully developed synthetic yeast cell factories to convert lignocellulosic substrates to valuable products, including aldehyde compounds. In this mini-review, we highlight the salient relationship of physicochemical characteristics and molecular toxicity of aldehydes, the molecular detoxification and macromolecules protection mechanisms of aldehydes, and the advances of engineering robust S. cerevisiae against complex mixtures of aldehyde inhibitors. KEY POINTS: • We reviewed structure-activity relationships of aldehyde toxicity on S. cerevisiae. • Two-tier protection mechanisms to alleviate aldehyde toxicity are presented. • We highlighted the strategies to overcome the synergistic toxicity of aldehydes.
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Affiliation(s)
- Lahiru N Jayakody
- School of Biological Sciences, Southern Illinois University Carbondale, Carbondale, IL, USA.
- Fermentation Science Institute, Southern Illinois University Carbondale, Carbondale, IL, USA.
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Biosa A, Outeiro TF, Bubacco L, Bisaglia M. Diabetes Mellitus as a Risk Factor for Parkinson's Disease: a Molecular Point of View. Mol Neurobiol 2018; 55:8754-8763. [PMID: 29594935 DOI: 10.1007/s12035-018-1025-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/20/2018] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by elevated concentrations of glucose in the blood. The chronic hyperglycemic state accounts for most of the vascular complications associated to the disease and the prevalent mechanism proposed is related to the glycating chemistry mediated by methylglyoxal (MG), which accumulates in T2DM. In recent years, a higher risk of Parkinson's disease (PD) onset in people affected by T2DM has become evident, but the molecular mechanisms underlying the interplay between T2DM and PD are still unknown. The oxidative chemistry of dopamine and its reactivity towards the protein α-Synuclein (aS) has been associated to the pathogenesis of PD. Recently, aS has also been described to interact with MG. Interestingly, MG and the dopamine oxidation products share both structural similarity and chemical reactivity. The ability of MG to spread over the site of its production and react with aS could represent the rationale to explain the higher incidence of PD in T2DM-affected people and may open opportunities for the development of novel strategies to antagonize the raise of PD.
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Affiliation(s)
- Alice Biosa
- Molecular Physiology and Biophysics Unit, Department of Biology, University of Padova, Padova, Italy
| | - Tiago F Outeiro
- Department of Experimental Neurodegeneration, University Medical Center Goettingen, Goettingen, Germany
- Max Planck Institute for Experimental Medicine, Goettingen, Germany
- Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK
| | - Luigi Bubacco
- Molecular Physiology and Biophysics Unit, Department of Biology, University of Padova, Padova, Italy
| | - Marco Bisaglia
- Molecular Physiology and Biophysics Unit, Department of Biology, University of Padova, Padova, Italy.
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Brown BE, Nobecourt E, Zeng J, Jenkins AJ, Rye KA, Davies MJ. Apolipoprotein A-I glycation by glucose and reactive aldehydes alters phospholipid affinity but not cholesterol export from lipid-laden macrophages. PLoS One 2013; 8:e65430. [PMID: 23741493 PMCID: PMC3669297 DOI: 10.1371/journal.pone.0065430] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
Increased protein glycation in people with diabetes may promote atherosclerosis. This study examined the effects of non-enzymatic glycation on the association of lipid-free apolipoproteinA-I (apoA-I) with phospholipid, and cholesterol efflux from lipid-loaded macrophages to lipid-free and lipid-associated apoA-I. Glycation of lipid-free apoA-I by methylglyoxal and glycolaldehyde resulted in Arg, Lys and Trp loss, advanced glycation end-product formation and protein cross-linking. The association of apoA-I glycated by glucose, methylglyoxal or glycolaldehyde with phospholipid multilamellar vesicles was impaired in a glycating agent dose-dependent manner, with exposure of apoA-I to both 30 mM glucose (42% decrease in kslow) and 3 mM glycolaldehyde (50% decrease in kfast, 60% decrease in kslow) resulting is significantly reduced affinity. Cholesterol efflux to control or glycated lipid-free apoA-I, or discoidal reconstituted HDL containing glycated apoA-I (drHDL), was examined using cholesterol-loaded murine (J774A.1) macrophages treated to increase expression of ATP binding cassette transporters A1 (ABCA1) or G1 (ABCG1). Cholesterol efflux from J774A.1 macrophages to glycated lipid-free apoA-I via ABCA1 or glycated drHDL via an ABCG1-dependent mechanism was unaltered, as was efflux to minimally modified apoA-I from people with Type 1 diabetes, or controls. Changes to protein structure and function were prevented by the reactive carbonyl scavenger aminoguanidine. Overall these studies demonstrate that glycation of lipid-free apoA-I, particularly late glycation, modifies its structure, its capacity to bind phospholipids and but not ABCA1- or ABCG1-dependent cholesterol efflux from macrophages.
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Affiliation(s)
- Bronwyn E. Brown
- The Heart Research Institute, Sydney, New South Wales, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | | | - Jingmin Zeng
- The Heart Research Institute, Sydney, New South Wales, Australia
| | - Alicia J. Jenkins
- Department of Medicine (St Vincent's), The University of Melbourne, Melbourne, Victoria, Australia
| | - Kerry-Anne Rye
- The Heart Research Institute, Sydney, New South Wales, Australia
- Department of Medicine (St Vincent's), The University of Melbourne, Melbourne, Victoria, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Michael J. Davies
- The Heart Research Institute, Sydney, New South Wales, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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Kim YS, Jung DH, Sohn E, Kim J, Kim JS. Glycoxidised LDL induced the upregulation of Axl receptor tyrosine kinase and its ligand in mouse mesangial cells. PLoS One 2012; 7:e50297. [PMID: 23226259 PMCID: PMC3511478 DOI: 10.1371/journal.pone.0050297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 10/17/2012] [Indexed: 12/21/2022] Open
Abstract
Aim/Hypothesis Low-density lipoprotein (LDL) is subjected to glycoxidation in diabetes, and a novel signalling mechanism by which glycoxidised LDL functions in glomerular mesangial cells remains to be ascertained. Methods We performed gene expression analysis in mouse glomerular mesangial cells treated with LDL modified by glycation and oxidation (GO-LDL, 100 µg/ml) for 48 h by using DNA microarray analysis and quantitative real-time PCR. We examined the GO-LDL-specific changes in gene and protein expression in mesangial cells and glomeruli of type 2 diabetic Zucker diabetic fatty (ZDF) rats. Results By microarray profiling, we noted that GO-LDL treatment increased Axl receptor tyrosine kinase (Axl) mRNA expression (∼2.5-fold, p<0.05) compared with normal LDL (N-LDL) treatment in mesangial cells. Treatment with GO-LDL also increased the protein levels of Axl and its ligand Gas6 as measured by Western blotting. These increases were inhibited by neutralising Axl receptor-specific antibody. Silencing Gas6 by siRNA inhibited GO-LDL-induced Axl expression in mesangial cells. Axl and Gas6 protein were also increased in cells cultured in high glucose (30 mM) or methylglyoxal (200 µM). Gas6 treatment increased the expression and secretion of TGF-β1 protein, a key regulator of extracellular matrix expression in the glomeruli of diabetic kidneys. Immunohistochemical analyses of glomeruli from 20-week-old ZDF rats exhibited increased Axl protein expression. Rottlerin, a selective PKC-δ inhibitor, completely blocked Gas6-induced TGF-β1 expression. Conclusions/Interpretation These data suggest that LDL modified by glycoxidation may mediate Axl/Gas6 pathway activation, and this mechanism may play a significant role in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Young Sook Kim
- Korean Medicine-Based Herbal Drug Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
| | - Dong Ho Jung
- Korean Medicine-Based Herbal Drug Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
| | - Eunjin Sohn
- Korean Medicine-Based Herbal Drug Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
| | - Junghyun Kim
- Korean Medicine-Based Herbal Drug Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
| | - Jin Sook Kim
- Korean Medicine-Based Herbal Drug Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea
- * E-mail:
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Effect of exposure of human monocyte-derived macrophages to high, versus normal, glucose on subsequent lipid accumulation from glycated and acetylated low-density lipoproteins. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:851280. [PMID: 21904540 PMCID: PMC3166758 DOI: 10.1155/2011/851280] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 06/29/2011] [Accepted: 07/01/2011] [Indexed: 11/17/2022]
Abstract
During atherosclerosis monocyte-derived macrophages accumulate cholesteryl esters from low-density lipoproteins (LDLs) via lectin-like oxidised LDL receptor-1 (LOX-1) and class AI and AII (SR-AI, SR-AII) and class B (SR-BI, CD36) scavenger receptors. Here we examined the hypothesis that hyperglycaemia may modulate receptor expression and hence lipid accumulation in macrophages. Human monocytes were matured into macrophages in 30 versus 5 mM glucose and receptor expression and lipid accumulation quantified. High glucose elevated LOX1 mRNA, but decreased SR-AI, SR-BI, LDLR, and CD36 mRNA. SR-BI and CD36 protein levels were decreased. Normo- and hyperglycaemic cells accumulated cholesteryl esters from modified LDL to a greater extent than control LDL, but total and individual cholesteryl ester accumulation was not affected by glucose levels. It is concluded that, whilst macrophage scavenger receptor mRNA and protein levels can be modulated by high glucose, these are not key factors in lipid accumulation by human macrophages under the conditions examined.
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Younis NN, Soran H, Sharma R, Charlton-Menys V, Durrington PN. Lipoprotein glycation in atherogenesis. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.61] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Nobécourt E, Zeng J, Davies MJ, Brown BE, Yadav S, Barter PJ, Rye KA. Effects of cross-link breakers, glycation inhibitors and insulin sensitisers on HDL function and the non-enzymatic glycation of apolipoprotein A-I. Diabetologia 2008; 51:1008-17. [PMID: 18437350 DOI: 10.1007/s00125-008-0986-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 02/22/2008] [Indexed: 01/24/2023]
Abstract
AIMS/HYPOTHESIS Hyperglycaemia, a key feature of diabetes, is associated with non-enzymatic glycation of plasma proteins. We have shown previously that the reactive alpha-oxoaldehyde, methylglyoxal, non-enzymatically glycates apolipoprotein (Apo)A-I, the main apolipoprotein of HDL, and prevents it from activating lecithin:cholesterol acyltransferase (LCAT), the enzyme that generates almost all of the cholesteryl esters in plasma. This study investigates whether the glycation inhibitors aminoguanidine and pyridoxamine, the insulin sensitiser metformin and the cross-link breaker alagebrium can inhibit and/or reverse the methylglyoxal-mediated glycation of ApoA-I and whether these changes can preserve or restore the ability of ApoA-I to activate LCAT. METHODS Inhibition of ApoA-I glycation was assessed by incubating aminoguanidine, pyridoxamine, metformin and alagebrium with mixtures of methylglyoxal and discoidal reconstituted HDL (rHDL) containing phosphatidylcholine and ApoA-I, ([A-I]rHDL). Glycation was assessed as the modification of ApoA-I arginine, lysine and tryptophan residues, and by the extent of ApoA-I cross-linking. The reversal of ApoA-I glycation was investigated by pre-incubating discoidal (A-I)rHDL with methylglyoxal, then incubating the modified rHDL with aminoguanidine, pyridoxamine or alagebrium. RESULTS Aminoguanidine, pyridoxamine, metformin and alagebrium all decreased the methylglyoxal-mediated glycation of the ApoA-I in discoidal rHDL and conserved the ability of the particles to act as substrates for LCAT. However, neither aminoguanidine, pyridoxamine nor alagebrium could reverse the glycation of ApoA-I or restore its ability to activate LCAT. CONCLUSIONS/INTERPRETATION Glycation inhibitors, insulin sensitisers and cross-link breakers are important for preserving normal HDL function in diabetes.
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Affiliation(s)
- E Nobécourt
- Lipid Research Group, The Heart Research Institute, 145 Missenden Road, Camperdown, Sydney, NSW 2050, Australia
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Bartling B, Desole M, Silber RE, Simm A. Dicarbonyl-mediated protein modifications affect matrix metalloproteinase (MMP) activity. Z Gerontol Geriatr 2008; 40:357-61. [PMID: 17943239 DOI: 10.1007/s00391-007-0485-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Accepted: 08/03/2007] [Indexed: 11/26/2022]
Abstract
Advanced age is linked with an increased incidence of epithelial tumours (carcinomas) including lung tumours. However, a slowing rate of the increase of age-specific cancer incidence is demonstrated at very advanced ages, and elderly patients also develop less invasive and metastatic tumours than their younger counterparts. Matrix metalloproteinases (MMPs) are commonly upregulated in the stromal compartment of the carcinoma tissue and are believed to promote invasion and metastasis. As the increased serum and tissue level of advanced glycation end products (AGEs) is a characteristic feature of old humans, our study focused on the impact of AGEs on the activity of MMPs released from lung fibroblasts (WI- 38). The collagen gel zymography technique showed the primary presence of MMP-2 in the conditioned medium of the WI-38 fibroblasts, which was even higher in senescent WI-38 fibroblasts. Subsequent treatment of the WI- 38 conditioned medium with the dicarbonyl compound glyoxal, a highly reactive precursor of the AGE formation, resulted in a dose-dependent reduction of the MMP-2 activity. Therefore, our study suggests that the age-associated increase in AGEs might be one potential host factor responsible for the less invasiveness of tumours at very advanced age.
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Affiliation(s)
- B Bartling
- Klinik für Herz- und Thoraxchirurgie, Universitätsklinikum der Martin-Luther-Universität Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle/Saale, Germany.
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Brown BE, Mahroof FM, Cook NL, van Reyk DM, Davies MJ. Hydrazine compounds inhibit glycation of low-density lipoproteins and prevent the in vitro formation of model foam cells from glycolaldehyde-modified low-density lipoproteins. Diabetologia 2006; 49:775-83. [PMID: 16465512 DOI: 10.1007/s00125-006-0137-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Accepted: 11/10/2005] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Previous studies have shown that glycation of LDL by methylglyoxal and glycolaldehyde, in the absence of significant oxidation, results in lipid accumulation in macrophage cells. Such 'foam cells' are a hallmark of atherosclerosis. In this study we examined whether LDL glycation by methylglyoxal or glycolaldehyde, and subsequent lipid loading of cells, can be inhibited by agents that scavenge reactive carbonyls. Such compounds may have therapeutic potential in diabetes-associated atherosclerosis. MATERIALS AND METHODS LDL was glycated with methylglyoxal or glycolaldehyde in the absence or presence of metformin, aminoguanidine, Girard's reagents P and T, or hydralazine. LDL modification was characterised by changes in mobility (agarose gel electrophoresis), cross-linking (SDS-PAGE) and loss of amino acid residues (HPLC). Accumulation of cholesterol and cholesteryl esters in murine macrophages was assessed by HPLC. RESULTS Inhibition of LDL glycation was detected with equimolar or greater concentrations of the scavengers over the reactive carbonyl. This inhibition was structure-dependent and accompanied by a modulation of cholesterol and cholesteryl ester accumulation. With aminoguanidine, Girard's reagent P and hydralazine, cellular sterol levels returned to control levels despite incomplete inhibition of LDL modification. CONCLUSIONS/INTERPRETATION Inhibition of LDL glycation by interception of the reactive aldehydes that induce LDL modification prevents lipid loading and model foam cell formation in murine macrophage cells. Carbonyl-scavenging reagents, such as hydrazines, may therefore help inhibit LDL glycation in vivo and prevent diabetes-induced atherosclerosis.
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Affiliation(s)
- B E Brown
- Free Radical Group, The Heart Research Institute, 145 Missenden Road, Camperdown, Sydney, NSW, 2050, Australia
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Taghi Good M, . MRS, . FZ. Inhibitory Action of Vit C and Mannitol on Induced Cytotoxic Effect of Glycated Protein-metal Ion on Rat Hepatocyte. INT J PHARMACOL 2006. [DOI: 10.3923/ijp.2006.201.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Julius U, Pietzsch J. Glucose-induced enhancement of hemin-catalyzed LDL oxidation in vitro and in vivo. Antioxid Redox Signal 2005; 7:1507-12. [PMID: 16356114 DOI: 10.1089/ars.2005.7.1507] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Growing evidence indicates that oxidative modification of low-density lipoprotein (LDL) is increased in diabetes mellitus; however, the mechanism(s) of this phenomenon is still unclear. gamma-Glutamyl semialdehyde (gammaGSA) is a product of hemin (Fe(3+)-protoporphyrin IX)-catalyzed oxidation of apolipoprotein B-100 (apoB- 100) proline and arginine residues. On reduction, gammaGSA forms 5-hydroxy-2-aminovaleric acid (HAVA). This report describes the application of sensitive HAVA assay, to characterize gammaGSA formation in LDL under normo- and hyperglycemic conditions, both in vitro and in vivo. In vitro studies revealed that apoB-100 proline and arginine residues are not oxidized to HAVA by HOCl or the myeloperoxidase/hydrogen peroxide (H(2)O(2)) oxidation system. Cu(2+), Cu(2+)/H(2)O(2), and Fe(2+) induced only minor HAVA formation. In contrast, the hemin oxidation system appeared reactive toward LDL apoB-100 proline and arginine residues. The resulting significant HAVA formation was specifically inhibited by a redox-inert ferric iron chelator. Glucose further enhanced hemin-induced increase in relative electrophoretic mobility of LDL and apoB-100 HAVAformation. In vivo we observed elevated concentrations of HAVA in LDL apoB-100 in patients with impaired glucose tolerance and with manifest diabetes mellitus. In conclusion, glucose promotes iron-mediated oxidation of apoB- 100 proline and arginine residues via a superoxide-dependent mechanism, thus rendering the LDL particles more atherogenic. The findings (a) identify a potential mechanism of enhanced atherogenesis in subjects with diabetes mellitus and (b) support the value of HAVA as a specific marker of LDL apoB-100 oxidation. Antioxid. Redox Signal. 7, 1507-1512.
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Affiliation(s)
- U Julius
- Medical Clinic and Outpatient Department III, University Hospital Dresden, Dresden, Germany.
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Brown BE, Dean RT, Davies MJ. Glycation of low-density lipoproteins by methylglyoxal and glycolaldehyde gives rise to the in vitro formation of lipid-laden cells. Diabetologia 2005; 48:361-9. [PMID: 15660260 DOI: 10.1007/s00125-004-1648-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Accepted: 09/11/2004] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS Previous studies have implicated the glycoxidative modification of low-density lipoprotein (LDL) by glucose and aldehydes (apparently comprising both glycation and oxidation), as a causative factor in the elevated levels of atherosclerosis observed in diabetic patients. Such LDL modification can result in unregulated cellular accumulation of lipids. In previous studies we have characterized the formation of glycated, but nonoxidized, LDL by glucose and aldehydes; in this study we examine whether glycation of LDL, in the absence of oxidation, gives rise to lipid accumulation in arterial wall cell types. METHODS Glycated LDLs were incubated with macrophage, smooth muscle, or endothelial cells. Lipid loading was assessed by HPLC analysis of cholesterol and individual esters. Oxidation was assessed by cholesterol ester loss and 7-ketocholesterol formation. Cell viability was assessed by lactate dehydrogenase release and cell protein levels. RESULTS Glycation of LDL by glycolaldehyde and methylglyoxal, but not glucose (in either the presence or absence of copper ions), resulted in cholesterol and cholesterol ester accumulation in macrophage cells, but not smooth muscle or endothelial cells. The extent of lipid accumulation depends on the degree of glycation, with increasing aldehyde concentration or incubation time, giving rise to greater extents of particle modification and lipid accumulation. Modification of lysine residues appears to be a key determinant of cellular uptake. CONCLUSIONS/INTERPRETATION These results are consistent with LDL glycation, in the absence of oxidation, being sufficient for rapid lipid accumulation by macrophage cells. Aldehyde-mediated "carbonyl-stress" may therefore facilitate the formation of lipid-laden (foam) cells in the artery wall.
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Affiliation(s)
- B E Brown
- Free Radical Group, The Heart Research Institute, 145 Missenden Road, Camperdown, Sydney 2050, Australia
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