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Zhao J, Chen P, Gregersen H. Stress-strain analysis of contractility in the ileum in response to flow and ramp distension in streptozotocin-induced diabetic rats--association with advanced glycation end product formation. J Biomech 2015; 48:1075-83. [PMID: 25682538 DOI: 10.1016/j.jbiomech.2015.01.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 12/23/2014] [Accepted: 01/24/2015] [Indexed: 12/28/2022]
Abstract
This study compared the ileal contractility and analyzed the association between contractility with advanced glycation end product (AGE) formation in normal and streptozotocin (STZ)-induced diabetic rats. Nine STZ-induced diabetic rats (Diabetes group) and 9 normal rats (Normal group) were used. The motility experiments were carried out on ileums in organ baths containing physiological Krebs solution. Ileal pressure and diameter changes were obtained from basic, flow-induced and ramp distension-induced contractions. The frequency and amplitude of contractions were analyzed from pressure-diameter curves. Distension-induced contraction thresholds and maximum contraction amplitude of basic and flow-induced contractions were calculated in terms of stress and strain. AGE and its receptor (RAGE) in the layers were detected by immunohistochemistry staining. The maximum stress of flow-induced contractions was lowest in the Diabetes Group (P<0.05). During ramp distension, the pressure and stress thresholds and Young's modulus to induce phasic contraction were lowest in the Diabetes Group (P<0.05 and P<0.01). AGE and RAGE expressions in the different ileum layers were highest in the Diabetes group. The contraction pressure and stress thresholds were significantly associated with AGE expression in the muscle layer and RAGE expression in mucosa epithelium and neurons. The diabetic intestine was hypersensitive to distension for contraction induction. However, the contraction force produced by smooth muscle was lowest in diabetic rats. Increased AGE/RAGE expression was associated with the contractility changes in diabetic rats.
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Affiliation(s)
- Jingbo Zhao
- Institute of Clinical medicine, Aarhus University, Brendstrupgaardsvej 100, Aarhus N 8200, Denmark; GIOME Center, College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Pengmin Chen
- Department of Molecular Biology, Institute of Clinical Medicine, China-Japan Friendship Hospital, Beijing 100029, China
| | - Hans Gregersen
- GIOME Center, College of Bioengineering, Chongqing University, Chongqing 400045, China.
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102
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Satheesan S, Figarola JL, Dabbs T, Rahbar S, Ermel R. Effects of a new advanced glycation inhibitor, LR-90, on mitigating arterial stiffening and improving arterial elasticity and compliance in a diabetic rat model: aortic impedance analysis. Br J Pharmacol 2015; 171:3103-14. [PMID: 24611770 DOI: 10.1111/bph.12656] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 02/08/2014] [Accepted: 02/17/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE We determined the effects of treatment with LR-90, an inhibitor of advanced glycation end products, on the mechanical properties of the arterial system in streptozotocin (STZ)-induced diabetic Sprague Dawley rats, using aortic impedance analysis, and further investigated the effects of LR-90 on the progression of aortic pathology. EXPERIMENTAL APPROACH STZ-induced diabetic rats were treated with or without LR-90 (50 mg L(-1) in drinking water) for 8 weeks and compared with control groups. Arterial BP measurements, various metabolic parameters, aortic histopathology, collagen cross-linking, AGE accumulation, and RAGE protein expression in aortic tissue were determined. Pulsatile parameters were evaluated using a standard Fourier series expansion technique and impulse response function of the filtered aortic input impedance spectra. KEY RESULTS LR-90 reduced glycated haemoglobin and triglycerides levels, although it had no effect on the glycaemic status. LR-90 did not affect arterial BP, but prevented the diabetes-induced increase in peripheral resistance and variations in aortic distensibility, as it reduced aortic characteristic impedance by 21%. LR-90 also prevented the elevation in wave reflection factor, as indicated by a 22.5% reduction and an associated increase of 23.5% in wave transit time, suggesting it prevents the augmentation of the systolic load of the left ventricle. Moreover, LR-90 inhibited collagen cross-linking and the accumulation of AGE and RAGE in the vasculature of diabetic rats. CONCLUSIONS AND IMPLICATIONS Treatment with LR-90 may impart significant protection against diabetes-induced aortic stiffening and cardiac hypertrophy and provides an additional therapeutic option for treatment of AGE associated diabetic complications.
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Affiliation(s)
- S Satheesan
- Division of Comparative Medicine, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, USA
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103
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Nikolakis G, Makrantonaki E, Zouboulis CC. Skin mirrors human aging. Horm Mol Biol Clin Investig 2015; 16:13-28. [PMID: 25436743 DOI: 10.1515/hmbci-2013-0018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 06/18/2013] [Indexed: 01/13/2023]
Abstract
Abstract Aged skin exhibits disturbed lipid barrier, angiogenesis, production of sweat, immune functions, and calcitriol synthesis as well as the tendency towards development of certain benign or malignant diseases. These complex biological processes comprise endogenous and exogenous factors. Ethnicity also markedly influences the phenotype of skin aging. The theories of cellular senescence, telomere shortening and decreased proliferative capacity, mitochondrial DNA single mutations, the inflammation theory, and the free radical theory try to explain the biological background of the global aging process, which is mirrored in the skin. The development of advanced glycation end-products and the declining hormonal levels are major factors influencing intrinsic aging. Chronic photodamage of the skin is the prime factor leading to extrinsic skin aging. The deterioration of important skin functions, due to intrinsic and extrinsic aging, leads to clinical manifestations, which mirror several internal age-associated diseases such as diabetes, arterial hypertension and malignancies.
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104
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Abstract
In vivo modification of proteins by molecules with reactive carbonyl groups leads to intermediate and advanced glycation end products (AGE). Glucose is a significant glycation reagent due to its high physiological concentration and poorly controlled diabetics show increased albumin glycation. Increased levels of glycated and AGE-modified albumin have been linked to diabetic complications, neurodegeneration, and vascular disease. This review discusses glycated albumin formation, structural consequences of albumin glycation on drug binding, removal of circulating AGE by several scavenger receptors, as well as AGE-induced proinflammatory signaling through activation of the receptor for AGE. Analytical methods for quantitative detection of protein glycation and AGE formation are compared. Finally, the use of glycated albumin as a novel clinical marker to monitor glycemic control is discussed and compared to glycated hemoglobin (HbA1c) as long-term indicator of glycemic status.
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105
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Haucke E, Navarrete-Santos A, Simm A, Silber RE, Hofmann B. Glycation of extracellular matrix proteins impairs migration of immune cells. Wound Repair Regen 2014; 22:239-45. [PMID: 24635174 DOI: 10.1111/wrr.12144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/21/2013] [Indexed: 11/30/2022]
Abstract
The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.
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Affiliation(s)
- Elisa Haucke
- Department of Cardiothoracic Surgery, Faculty of Medicine, Martin Luther University, Halle, Saale, Germany
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106
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Thomas SJ, Sarver JJ, Yannascoli SM, Tucker JJ, Kelly JD, Ahima RS, Barbe MF, Soslowsky LJ. Effect of isolated hyperglycemia on native mechanical and biologic shoulder joint properties in a rat model. J Orthop Res 2014; 32:1464-70. [PMID: 25070655 PMCID: PMC4406419 DOI: 10.1002/jor.22695] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 06/23/2014] [Indexed: 02/04/2023]
Abstract
Recently, diabetes has been linked to rotator cuff disease and adhesive capsulitis, conditions with increased stiffness and inflammation. Unfortunately, limited research exists examining how hyperglycemia affects the native shoulder (tendon and capsule) properties. Therefore, the objectives of this study were to compare shoulder joint mechanics, tendon properties (mechanics and immunohistochemistry), and capsule of healthy control and hyperglycemic rats 8 weeks following induction of hyperglycemia with a submaximal dose of streptozotocin (STZ). Eighteen rats were injected with STZ to induce hyperglycemia or citrate buffer (control) and underwent normal cage activity for 8 weeks. Passive joint mechanics demonstrated significantly less external rotation in the hyperglycemic group compared to controls, with no other group differences. Tendon mechanical properties (stiffness and modulus) were not significantly different between groups at both the insertion site and mid-substance. Immunohistochemistry staining of the tendon and capsule demonstrated significantly increased interleukin 1-beta (IL1-β) and advanced glycated end-products (AGE) staining localized to the insertion and mid-substance of the tendon but not the capsule. In addition, tumor necrosis factor alpha (TNF-α) staining was significantly increased in the superior capsule but not the supraspinatus tendon. This study demonstrates that isolated hypergylcemia does not diminish shoulder mechanical properties but does induce a chronic inflammatory response.
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Affiliation(s)
- Stephen J. Thomas
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph J. Sarver
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarah M. Yannascoli
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennica J. Tucker
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA
| | - John D. Kelly
- Department of Orthopeadic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Rexford S. Ahima
- Department of Endocrinology, Diabetes and Metabolism, University of Pennsylvania, Philadelphia, PA, USA
| | - Mary F. Barbe
- Department of Anatomy and Cell Biology, Temple University, Philadelphia, PA, USA
| | - Louis J. Soslowsky
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, USA
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107
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Willett TL, Pasquale J, Grynpas MD. Collagen modifications in postmenopausal osteoporosis: advanced glycation endproducts may affect bone volume, structure and quality. Curr Osteoporos Rep 2014; 12:329-37. [PMID: 24880722 DOI: 10.1007/s11914-014-0214-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The classic model of postmenopausal osteoporosis (PM-OP) starts with the depletion of estrogen, which in turn stimulates imbalanced bone remodeling, resulting in loss of bone mass/volume. Clinically, this leads to fractures because of structural weakness. Recent work has begun to provide a more complete picture of the mechanisms of PM-OP involving oxidative stress and collagen modifications known as advanced glycation endproducts (AGEs). On one hand, AGEs may drive imbalanced bone remodeling through signaling mediated by the receptor for AGEs (RAGE), stimulating resorption and inhibiting formation. On the other hand, AGEs are associated with degraded bone material quality. Oxidative stress promotes the formation of AGEs, inhibits normal enzymatically derived crosslinking and can degrade collagen structure, thereby reducing fracture resistance. Notably, there are multiple positive feedback loops that can exacerbate the mechanisms of PM-OP associated with oxidative stress and AGEs. Anti-oxidant therapies may have the potential to inhibit the oxidative stress based mechanisms of this disease.
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Affiliation(s)
- Thomas L Willett
- Musculoskeletal Research Laboratory, Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Box 42, Toronto, Ontario, Canada, M5T 3L9,
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108
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Effect of nicotinamide on amino acids content in bone collagen depending on biological availability of vitamins in diabetic rats. UKRAINIAN BIOCHEMICAL JOURNAL 2014; 86:138-49. [DOI: 10.15407/ubj86.04.138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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109
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Zeltz C, Gullberg D. Post-translational modifications of integrin ligands as pathogenic mechanisms in disease. Matrix Biol 2014; 40:5-9. [PMID: 25116951 DOI: 10.1016/j.matbio.2014.08.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/01/2014] [Accepted: 08/01/2014] [Indexed: 12/24/2022]
Abstract
Protein post-translational modifications like glycation, carbamylation and citrullination increase the functional diversity of the proteome but in disease situations might do more harm than good. Post-translational modifications of ECM proteins are thus appearing as mechanisms, which contribute to tissue dysfunction in chronic kidney disease, in diabetes and in various inflammatory diseases. In chronic renal failure, carbamylation could lead to kidney fibrosis. In diabetes, high glucose levels lead to non-enzymatic glycation and cross-linking of collagens, which contribute to tissue stiffening with consequences for cardiovascular and renal functions. In inflammatory diseases, citrullination deiminates arginine residues with possible consequences for integrin-mediated cell adhesion to RGD- and GFOGER sequences in ECM proteins. Citrullination of fibronectin was in one study suggested to affect cell adhesion by modifying the heparin-binding site and not the RGD site. In a recent publication citrullination of GFOGER sequences in collagen II was demonstrated to selectively affect α10β1 and α11β1 integrin-mediated cell adhesion to collagen II, with consequences for synovial fibroblast and stem cell adhesion and migration. The implications of citrullination affecting integrin binding in disease open up a new area of study and might have implications for the pathogenesis of inflammatory diseases like rheumatoid arthritis and periodontitis.
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Affiliation(s)
- Cédric Zeltz
- Department of Biomedicine and Centre for Cancer Biomarkers, Norwegian Centre of Excellence, University of Bergen, Jonas Lies Vei 91, N-5009 Bergen, Norway
| | - Donald Gullberg
- Department of Biomedicine and Centre for Cancer Biomarkers, Norwegian Centre of Excellence, University of Bergen, Jonas Lies Vei 91, N-5009 Bergen, Norway.
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110
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Eriksen C, Svensson RB, Scheijen J, Hag AMF, Schalkwijk C, Praet SFE, Schjerling P, Kjær M, Magnusson SP, Couppé C. Systemic stiffening of mouse tail tendon is related to dietary advanced glycation end products but not high-fat diet or cholesterol. J Appl Physiol (1985) 2014; 117:840-7. [PMID: 25103969 DOI: 10.1152/japplphysiol.00584.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Tendon pathology is related to metabolic disease and mechanical overloading, but the effect of metabolic disease on tendon mechanics is unknown. This study investigated the effect of diet and apolipoprotein E deficiency (ApoE(-/-)) on mechanical properties and advanced glycation end product (AGE) cross-linking of non-weight-bearing mouse tail tendons. Twenty ApoE(-/-) male mice were used as a model for hypercholesterolemia along with 26 wild-type (WT) mice. One-half of the mice from each group was fed a normal diet (ND) and the other half was fed a high-fat diet (HFD) to induce obesity. All were killed at 40 wk, and tail tendon fascicles were mechanically tested to failure and analyzed for AGEs. Diets were also analyzed for AGEs. ApoE(-/-) mice displayed a 14% increase in plateau modulus compared with WT mice (P < 0.05), whereas HFD mice displayed a 13% decrease in plateau modulus (P < 0.05) and a 12% decrease in total modulus (P < 0.05) compared with ND mice. Tail tendons of HFD mice had significantly lower concentrations of AGEs [carboxymethyllysine (CML): 26%, P < 0.0001; methylglyoxal-derived hydroimidazolone 1 (MG-H1): 15%, P < 0.005; pentosidine: 13%, P < 0.0005]. The HFD had ∼44-fold lower content of CML (P < 0.01), ∼29-fold lower content of carboxyethyllysine (P < 0.005), and ∼16-fold lower content of MG-H1 (P < 0.05) compared with ND. ApoE(-/-) increased, whereas HFD decreased mouse tail tendon stiffness. Dietary AGE content may be a crucial determinant for accumulation of AGE cross-links in tendons and for tissue compliance. The results demonstrate how systemic metabolic factors may influence tendon health.
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Affiliation(s)
- C Eriksen
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - R B Svensson
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - J Scheijen
- Department of Internal Medicine and Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, The Netherlands
| | - A M F Hag
- Cluster for Molecular Imaging, Faculty of Health and Medical Sciences and Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Denmark
| | - C Schalkwijk
- Department of Internal Medicine and Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, The Netherlands
| | - S F E Praet
- Department of Rehabilitation Medicine, MOVEFIT- Sports medicine, Erasmus University Medical Centre, Rotterdam, The Netherlands; and
| | - P Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - M Kjær
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - S P Magnusson
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Physical Therapy, Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital, Denmark
| | - C Couppé
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Physical Therapy, Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital, Denmark
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111
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Duan L, Liu W, Tian Z, Li C, Li G. Properties of collagen gels cross-linked by N-hydroxysuccinimide activated adipic acid deriviate. Int J Biol Macromol 2014; 69:482-8. [DOI: 10.1016/j.ijbiomac.2014.06.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 06/04/2014] [Accepted: 06/07/2014] [Indexed: 10/25/2022]
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112
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Danoux L, Mine S, Abdul-Malak N, Henry F, Jeanmaire C, Freis O, Pauly G, Cittadini L, André-Frei V, Rathjens A. How to help the skin cope with glycoxidation. Clin Chem Lab Med 2014; 52:175-82. [PMID: 23612546 DOI: 10.1515/cclm-2012-0828] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/07/2013] [Indexed: 11/15/2022]
Abstract
BACKGROUND Protein glycation refers to the spontaneous reaction of reducing sugars with proteins and the subsequent formation of stable advanced glycation end products (AGEs). Glycation is linked with oxidative stress, and this association is called "glycoxidation". Glycoxidation alters the protein structure and function and causes tissue aging, as seen in human skin. Therefore, research on substances inhibiting glycoxidation appears to be crucial in the prevention of skin aging. With this aim, several plant extracts have been screened for antiglycation activity, and the results of the best candidates are presented in this article. METHODS Glycation was studied on human skin proteins (collagen, elastin, and albumin) and on a model of reconstructed skin. Oxidative stress has been addressed by testing the copper-induced low-density lipoprotein oxidation, ultraviolet irradiation of glycated dermis, and carbonyl activation of human dermal fibroblasts. A clinical test evaluated the extent of oxidative stress induced by ultraviolet A irradiation. RESULTS Among the tested products, several plant extracts have decreased the glycation effects on skin proteins collagen, elastin, and albumin. In addition, a plant extract has significantly inhibited the different forms of oxidative stress associated with protein glycation. CONCLUSIONS We have demonstrated that plant extracts can relieve the deleterious effects of glycation on human skin. Moreover, a plant extract rich in antioxidant molecules has also significantly preserved the human skin from glycoxidation attacks.
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113
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Kellow NJ, Coughlan MT, Savige GS, Reid CM. Effect of dietary prebiotic supplementation on advanced glycation, insulin resistance and inflammatory biomarkers in adults with pre-diabetes: a study protocol for a double-blind placebo-controlled randomised crossover clinical trial. BMC Endocr Disord 2014; 14:55. [PMID: 25011647 PMCID: PMC4099169 DOI: 10.1186/1472-6823-14-55] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 06/30/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Advanced glycation endproducts (AGEs) contribute to the development of vascular complications of diabetes and have been recently implicated in the pathogenesis of diabetes. Since AGEs are generated within foodstuffs upon food processing, it is increasingly recognised that the modern diet is replete with AGEs. AGEs are thought to stimulate chronic low-grade inflammation and promote oxidative stress and have been linked to the development of insulin resistance. Simple therapeutic strategies targeted at attenuating the progression of chronic low-grade inflammation and insulin resistance are urgently required to prevent or slow the development of type 2 diabetes in susceptible individuals. Dietary modulation of the human colonic microbiota has been shown to confer a number of health benefits to the host, but its effect on advanced glycation is unknown. The aim of this article is to describe the methodology of a double-blind placebo-controlled randomised crossover trial designed to determine the effect of 12 week consumption of a prebiotic dietary supplement on the advanced glycation pathway, insulin sensitivity and chronic low-grade inflammation in adults with pre-diabetes. METHODS/DESIGN Thirty adults with pre-diabetes (Impaired Glucose Tolerance or Impaired Fasting Glucose) aged between 40-60 years will be randomly assigned to receive either 10 grams of prebiotic (inulin/oligofructose) daily or 10 grams placebo (maltodextrin) daily for 12 weeks. After a 2-week washout period, study subjects will crossover to receive the alternative dietary treatment for 12 weeks. The primary outcome is the difference in markers of the advanced glycation pathway carboxymethyllysine (CML) and methylglyoxal (MG) between experimental and control treatments. Secondary outcomes include HbA1c, insulin sensitivity, lipid levels, blood pressure, serum glutathione, adiponectin, IL-6, E-selectin, myeloperoxidase, C-reactive protein, Toll-like Receptor 4 (TLR4), soluble receptor for AGE (sRAGE), urinary 8-isoprostanes, faecal bacterial composition and short chain fatty acid profile. Anthropometric measures including BMI and waist circumference will be collected in addition to comprehensive dietary and lifestyle data. DISCUSSION Prebiotics which selectively stimulate the growth of beneficial bacteria in the human colon might offer protection against AGE-related pathology in people at risk of developing type 2 diabetes. TRIAL REGISTRATION Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12613000130763.
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Affiliation(s)
- Nicole J Kellow
- Department of Epidemiology & Preventive Medicine, School of Public Health & Preventive Medicine, Monash University, The Alfred Centre, Melbourne, Victoria 3004, Australia
| | - Melinda T Coughlan
- Glycation, Nutrition & Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, Victoria 8008, Australia
- Department of Medicine, Central Clinical School, Monash University, Alfred Medical Research & Education Precinct, Melbourne, Victoria 3004, Australia
| | - Gayle S Savige
- Department of Epidemiology & Preventive Medicine, School of Public Health & Preventive Medicine, Monash University, The Alfred Centre, Melbourne, Victoria 3004, Australia
| | - Christopher M Reid
- Department of Epidemiology & Preventive Medicine, School of Public Health & Preventive Medicine, Monash University, The Alfred Centre, Melbourne, Victoria 3004, Australia
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114
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Hellwig M, Henle T. Backen, Altern, Diabetes: eine kurze Geschichte der Maillard-Reaktion. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201308808] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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115
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Hellwig M, Henle T. Baking, ageing, diabetes: a short history of the Maillard reaction. Angew Chem Int Ed Engl 2014; 53:10316-29. [PMID: 25044982 DOI: 10.1002/anie.201308808] [Citation(s) in RCA: 302] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/12/2013] [Indexed: 01/11/2023]
Abstract
The reaction of reducing carbohydrates with amino compounds described in 1912 by Louis-Camille Maillard is responsible for the aroma, taste, and appearance of thermally processed food. The discovery that non-enzymatic conversions also occur in organisms led to intensive investigation of the pathophysiological significance of the Maillard reaction in diabetes and ageing processes. Dietary Maillard products are discussed as "glycotoxins" and thus as a nutritional risk, but also increasingly with regard to positive effects in the human body. In this Review we give an overview of the most important discoveries in Maillard research since it was first described and show that the complex reaction, even after over one hundred years, has lost none of its interdisciplinary actuality.
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Affiliation(s)
- Michael Hellwig
- Chair of Food Chemistry, Technische Universität Dresden, D-01062 Dresden (Germany) http://www.chm.tu-dresden.de/lc1
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116
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Rolewska P, Simm A, Silber RE, Bartling B. Reduced expression level of the cyclic adenosine monophosphate response element-binding protein contributes to lung aging. Am J Respir Cell Mol Biol 2014; 50:201-11. [PMID: 23991634 DOI: 10.1165/rcmb.2013-0057oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Lung aging is associated with morphological and physiological changes in which alterations in transcription factors, including the cyclic adenosine monophosphate response element-binding protein (CREB), could play a role. We studied CREB in lung tissue from mice at different ages and in response to known age-related factors (e.g., cellular senescence and matrix modifications with advanced glycation end-products [AGEs]). Our study shows that protein but not mRNA levels of CREB are reduced in the lungs of old mice. CREB reduction was also observed in senescent human lung fibroblasts (WI-38, LuFi) and human lung epithelial cells (A549) cultured on AGE-modified collagen matrix. Reduction of CREB protein is partially based on pre- and posttranslational modifications as exhibited by an increase in the CREB-regulating microRNA 34b and CREB ubiquitination. Permanent down-regulation of CREB in lung cells impaired cell proliferation and viability and increased the number of cells with senescence-associated β-galactosidase activity. CREB down-regulation was accompanied by the reduced expression of 165 genes in WI-38 fibroblasts and A549 epithelial cells, of which 15 genes showed a reduced expression in lung tissues of old mice. The CREB-dependent reduction in RAB27A coding for the Ras-related protein Rab27A and IGFBP3 coding for the insulin-like growth factor-binding protein 3 has been confirmed for aged lung tissue, senescent fibroblasts, and lung epithelial cells on AGE-modified collagen. Our data demonstrate that the reduced protein expression of CREB might play a significant role in lung aging by modifying the transcription of RAB27A, IGFBP3, and other target genes.
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Affiliation(s)
- Paulina Rolewska
- 1 Department of Cardio-Thoracic Surgery, University Hospital Halle/Saale, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
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Singh VP, Bali A, Singh N, Jaggi AS. Advanced glycation end products and diabetic complications. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:1-14. [PMID: 24634591 PMCID: PMC3951818 DOI: 10.4196/kjpp.2014.18.1.1] [Citation(s) in RCA: 873] [Impact Index Per Article: 87.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/11/2013] [Accepted: 12/10/2013] [Indexed: 02/06/2023]
Abstract
During long standing hyperglycaemic state in diabetes mellitus, glucose forms covalent adducts with the plasma proteins through a non-enzymatic process known as glycation. Protein glycation and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic complications like retinopathy, nephropathy, neuropathy, cardiomyopathy along with some other diseases such as rheumatoid arthritis, osteoporosis and aging. Glycation of proteins interferes with their normal functions by disrupting molecular conformation, altering enzymatic activity, and interfering with receptor functioning. AGEs form intra- and extracellular cross linking not only with proteins, but with some other endogenous key molecules including lipids and nucleic acids to contribute in the development of diabetic complications. Recent studies suggest that AGEs interact with plasma membrane localized receptors for AGEs (RAGE) to alter intracellular signaling, gene expression, release of pro-inflammatory molecules and free radicals. The present review discusses the glycation of plasma proteins such as albumin, fibrinogen, globulins and collagen to form different types of AGEs. Furthermore, the role of AGEs in the pathogenesis of diabetic complications including retinopathy, cataract, neuropathy, nephropathy and cardiomyopathy is also discussed.
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Affiliation(s)
- Varun Parkash Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Anjana Bali
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Nirmal Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
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118
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Singh VP, Bali A, Singh N, Jaggi AS. Advanced glycation end products and diabetic complications. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014. [PMID: 24634591 DOI: 10.4196/kjpp] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During long standing hyperglycaemic state in diabetes mellitus, glucose forms covalent adducts with the plasma proteins through a non-enzymatic process known as glycation. Protein glycation and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic complications like retinopathy, nephropathy, neuropathy, cardiomyopathy along with some other diseases such as rheumatoid arthritis, osteoporosis and aging. Glycation of proteins interferes with their normal functions by disrupting molecular conformation, altering enzymatic activity, and interfering with receptor functioning. AGEs form intra- and extracellular cross linking not only with proteins, but with some other endogenous key molecules including lipids and nucleic acids to contribute in the development of diabetic complications. Recent studies suggest that AGEs interact with plasma membrane localized receptors for AGEs (RAGE) to alter intracellular signaling, gene expression, release of pro-inflammatory molecules and free radicals. The present review discusses the glycation of plasma proteins such as albumin, fibrinogen, globulins and collagen to form different types of AGEs. Furthermore, the role of AGEs in the pathogenesis of diabetic complications including retinopathy, cataract, neuropathy, nephropathy and cardiomyopathy is also discussed.
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Affiliation(s)
- Varun Parkash Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Anjana Bali
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Nirmal Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India
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119
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Gautieri A, Redaelli A, Buehler MJ, Vesentini S. Age- and diabetes-related nonenzymatic crosslinks in collagen fibrils: Candidate amino acids involved in Advanced Glycation End-products. Matrix Biol 2014; 34:89-95. [DOI: 10.1016/j.matbio.2013.09.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/16/2013] [Accepted: 09/16/2013] [Indexed: 01/22/2023]
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Collagen as a double-edged sword in tumor progression. Tumour Biol 2013; 35:2871-82. [PMID: 24338768 PMCID: PMC3980040 DOI: 10.1007/s13277-013-1511-7] [Citation(s) in RCA: 363] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/03/2013] [Indexed: 12/11/2022] Open
Abstract
It has been recognized that cancer is not merely a disease of tumor cells, but a disease of imbalance, in which stromal cells and tumor microenvironment play crucial roles. Extracellular matrix (ECM) as the most abundant component in tumor microenvironment can regulate tumor cell behaviors and tissue tension homeostasis. Collagen constitutes the scaffold of tumor microenvironment and affects tumor microenvironment such that it regulates ECM remodeling by collagen degradation and re-deposition, and promotes tumor infiltration, angiogenesis, invasion and migration. While collagen was traditionally regarded as a passive barrier to resist tumor cells, it is now evident that collagen is also actively involved in promoting tumor progression. Collagen changes in tumor microenvironment release biomechanical signals, which are sensed by both tumor cells and stromal cells, trigger a cascade of biological events. In this work, we discuss how collagen can be a double-edged sword in tumor progression, both inhibiting and promoting tumor progression at different stages of cancer development.
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121
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Quondamatteo F. Skin and diabetes mellitus: what do we know? Cell Tissue Res 2013; 355:1-21. [PMID: 24318789 DOI: 10.1007/s00441-013-1751-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 10/29/2013] [Indexed: 12/20/2022]
Abstract
Diabetes mellitus (DM) is becoming increasingly prevalent worldwide. Although major complications of this condition involve kidney, retina and peripheral nerves, the skin of diabetic patients is also frequently injured. Hence, interest is mounting in the definition of the structural and molecular profile of non-complicated diabetic skin, i.e., before injuries occur. Most of the available knowledge in this area has been obtained relatively recently and, in part, derives from various diabetic animal models. These include both insulin-dependent and insulin-resistant models. Structural work in human diabetic skin has also been carried out by means of tissue samples or of non-invasive methods. Indications have indeed been found for molecular/structural changes in diabetic skin. However, the overall picture that emerges is heterogeneous, incomplete and often contradictory and many questions remain unanswered. This review aims to detail, as much as possible, the various pieces of current knowledge in a systematic and synoptic manner. This should aid the identification of areas in which key questions are still open and more research is needed. A comprehensive understanding of this field could help in determining molecular targets for the prevention and treatment of skin injuries in DM and markers for the monitoring of cutaneous and systemic aspects of the disease. Additionally, with the increasing development of non-invasive optics-based deep-tissue-imaging diagnostic technologies, precise knowledge of cutaneous texture and molecular structure becomes an important pre-requisite for the use of such methods in diabetic patients.
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Affiliation(s)
- Fabio Quondamatteo
- Skin and ECM Research Group-Anatomy, NUI Galway, Anatomy Building, University Road, Galway, Ireland,
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122
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Protein glycation during aging and in cardiovascular disease. J Proteomics 2013; 92:248-59. [DOI: 10.1016/j.jprot.2013.05.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/08/2013] [Accepted: 05/12/2013] [Indexed: 01/11/2023]
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123
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Guilbert M, Said G, Happillon T, Untereiner V, Garnotel R, Jeannesson P, Sockalingum GD. Probing non-enzymatic glycation of type I collagen: A novel approach using Raman and infrared biophotonic methods. Biochim Biophys Acta Gen Subj 2013; 1830:3525-31. [DOI: 10.1016/j.bbagen.2013.01.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 01/08/2013] [Accepted: 01/13/2013] [Indexed: 11/25/2022]
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124
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Li Y, Fessel G, Georgiadis M, Snedeker JG. Advanced glycation end-products diminish tendon collagen fiber sliding. Matrix Biol 2013; 32:169-77. [DOI: 10.1016/j.matbio.2013.01.003] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 01/07/2013] [Accepted: 01/07/2013] [Indexed: 12/29/2022]
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125
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Gkogkolou P, Böhm M. Advanced glycation end products: Key players in skin aging? DERMATO-ENDOCRINOLOGY 2013; 4:259-70. [PMID: 23467327 PMCID: PMC3583887 DOI: 10.4161/derm.22028] [Citation(s) in RCA: 346] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aging is the progressive accumulation of damage to an organism over time leading to disease and death. Aging research has been very intensive in the last years aiming at characterizing the pathophysiology of aging and finding possibilities to fight age-related diseases. Various theories of aging have been proposed. In the last years advanced glycation end products (AGEs) have received particular attention in this context. AGEs are formed in high amounts in diabetes but also in the physiological organism during aging. They have been etiologically implicated in numerous diabetes- and age-related diseases. Strategies inhibiting AGE accumulation and signaling seem to possess a therapeutic potential in these pathologies. However, still little is known on the precise role of AGEs during skin aging. In this review the existing literature on AGEs and skin aging will be reviewed. In addition, existing and potential anti-AGE strategies that may be beneficial on skin aging will be discussed.
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Affiliation(s)
- Paraskevi Gkogkolou
- Department of Dermatology; Laboratory for Neuroendocrinology of the Skin and Interdisciplinary Endocrinology; University of Münster; Münster, Germany
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Noordam R, Gunn DA, Tomlin CC, Maier AB, Mooijaart SP, Slagboom PE, Westendorp RGJ, de Craen AJM, van Heemst D. High serum glucose levels are associated with a higher perceived age. AGE (DORDRECHT, NETHERLANDS) 2013; 35:189-95. [PMID: 22102339 PMCID: PMC3543736 DOI: 10.1007/s11357-011-9339-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 10/25/2011] [Indexed: 05/09/2023]
Abstract
Estimating perceived age by facial photographs is a good estimate of health in elderly populations. Previously, we showed that familial longevity is marked by a more beneficial glucose metabolism already at middle age. As glucose is also related to skin aging, this study aimed to investigate the association between glucose metabolism and perceived age. Perceived age was assessed using facial photographs and non-fasted glucose and insulin were measured in 602 subjects from the Leiden Longevity Study. Non-diabetic subjects (n = 569) were divided in three strata according to their glucose levels, and diabetic subjects (n = 33; as a proxy of long-term hyperglycemic exposure) were included as a fourth stratum. Considered confounding factors were gender, chronological age, current smoking, body mass index, photo-damage score, and insulin levels. Perceived age was increased from 59.6 years (SE = 0.3) in the first stratum to 61.2 years (SE = 0.6) in diabetic subjects (p for trend = 0.002). In non-diabetic subjects only, perceived age was increased from 59.6 years (SE = 0.3) in the first stratum to 60.6 years (SE = 0.3) in the third stratum (p for trend = 0.009). Continuously, perceived age increased 0.40 years (SE = 0.14, p = 0.006) per 1 mmol/L increase in glucose level in non-diabetic subjects. The present study demonstrates that, also among non-diabetic subjects, higher glucose levels are associated with a higher perceived age. Future research should be focused on elucidating possible mechanisms linking glucose levels to perceived age.
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Affiliation(s)
- Raymond Noordam
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - David A. Gunn
- Unilever Discover, Colworth House, Sharnbrook, Bedfordshire UK
| | | | - Andrea B. Maier
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Simon P. Mooijaart
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - P. Eline Slagboom
- Section of Molecular Epidemiology, Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, the Netherlands
- Netherlands Consortium of Healthy Aging (NCHA), Leiden, The Netherlands
| | - Rudi G. J. Westendorp
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
- Netherlands Consortium of Healthy Aging (NCHA), Leiden, The Netherlands
| | - Anton J. M. de Craen
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Diana van Heemst
- Department of Gerontology and Geriatrics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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127
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Willett TL, Sutty S, Gaspar A, Avery N, Grynpas M. In vitro non-enzymatic ribation reduces post-yield strain accommodation in cortical bone. Bone 2013. [PMID: 23178516 DOI: 10.1016/j.bone.2012.11.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Non-enzymatic glycation (NEG) and advanced glycation endproducts (AGEs) may contribute to bone fragility in various diseases, ageing, and other conditions by modifying bone collagen and causing degraded mechanical properties. In this study, we sought to further understand how collagen modification in an in vitro non-enzymatic ribation model leads to loss of cortical bone toughness. Previous in vitro studies using non-enzymatic ribation reported loss of ductility in the cortical bone. Increased crosslinking is most commonly blamed for these changes; however, some studies report positive correlations between measures of total collagen crosslinking and work-to-fracture/toughness measurements whilst correlations between general NEG and measures of ductility are often negative. Fifteen bone beam triplets were cut from bovine metatarsi. Each provided one native non-incubated control, one incubated control and one ribated specimen. Incubation involved simulated body fluid±ribose for fourteen days at 37°C. Pentosidine and pyridinoline crosslinks were measured using HPLC. Three-point bending tests quantified mechanical properties. Fracture surfaces were examined using scanning electron microscopy. The effects of ribation on bone collagen molecular stability and intermolecular connectivity were investigated using differential scanning calorimetry and hydrothermal isometric tension testing. Ribation caused increased non-enzymatic collagen modification and pentosidine content (16mmol/mol collagen) and inferior post-yield mechanical behaviour, especially post-yield strain and flexural toughness. Fracture surfaces were smoother with less collagen fibril deformation or tearing than observed in controls. In the ribated group only, pentosidine content and thermomechanical measures of crosslinking were positively correlated with measures of strain accommodation and energy absorption before failure. Non-enzymatic ribation and the resulting modifications reduce cortical bone pseudo-plasticity through a reduced capacity for post-yield strain accommodation. However, the positive correlations we have found suggest that increased crosslinking may not provide a complete explanation for this embrittlement.
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Affiliation(s)
- Thomas L Willett
- Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, 100 College Street, Toronto, Ontario, Canada M5G 1L5.
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128
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Rolewska P, Al-Robaiy S, Navarrete Santos A, Simm A, Silber RE, Bartling B. Age‐related expression, enzymatic solubility and modification with advanced glycation end‐products of fibrillar collagens in mouse lung. Exp Gerontol 2013; 48:29-37. [DOI: 10.1016/j.exger.2012.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 04/12/2012] [Accepted: 04/18/2012] [Indexed: 12/28/2022]
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129
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Valle E, Storace D, Sanguineti R, Carter R, Odetti P, Geor R, Bergero D. Association of the glycoxidative stress marker pentosidine with equine laminitis. Vet J 2012. [PMID: 23206662 DOI: 10.1016/j.tvjl.2012.10.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Ponies suffering from recurrent episodes of laminitis when grazed at pasture (pasture-associated laminitis) exhibit phenotypes similar to those associated with human metabolic syndrome. In humans, evidence suggests that the obesity-related morbidities associated with metabolic syndrome, including diabetes and cardiovascular disease, are caused by an increase in the production of advanced glycoxidation end-products (AGEs). These end-products have been recognised as putative pro-inflammatory mediators and are considered a 'risk factor' for human health. However, the evaluation of AGEs in laminitic ponies has not been explored. The aim of this study was to compare plasma concentrations of the AGE pentosidine (PENT) in ponies presenting with clinical features of equine metabolic syndrome (EMS) with a history of recent laminitis and/or showing signs of laminitis at the time of sampling (LP) with those with no prior history of clinical laminitis (NL). Age, body condition score (BCS) and bodyweight were recorded and blood samples collected for the measurement of plasma concentrations of PENT, glucose, insulin, triglycerides (TG), non-esterified fatty acids (NEFA) and cortisol. Insulin sensitivity was assessed by the reciprocal of the square root of insulin (RISQI) and the insulin:glucose ratio. Plasma PENT concentrations were twofold higher (P<0.005) in LP than in NL ponies. Significant (P<0.05) correlations were also evident between PENT and insulin, RISQI, TG and age. These preliminary findings are consistent with the hypothesis that glycoxidation in laminitis is associated with EMS.
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Affiliation(s)
- E Valle
- Department of Animal Production, Epidemiology and Ecology, Faculty of Veterinary Medicine, University of Turin, Italy.
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130
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Indurthi VS, Leclerc E, Vetter SW. Interaction between glycated serum albumin and AGE-receptors depends on structural changes and the glycation reagent. Arch Biochem Biophys 2012; 528:185-96. [DOI: 10.1016/j.abb.2012.10.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 10/03/2012] [Accepted: 10/06/2012] [Indexed: 10/27/2022]
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131
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Diabetes-mediated changes in rat type i collagen and spermatogenesis indices. ROMANIAN JOURNAL OF DIABETES NUTRITION AND METABOLIC DISEASES 2012. [DOI: 10.2478/v10255-012-0030-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract Objectives: To investigate the effects of diabetes on the reproductive system andextracellular matrix proteins of diabetic rats. Materials and Methods: Wistar albinomale rats, body weight (BW) 160-200 g, were divided into two groups: I -streptozoticin diabetes, II - normal non-diabetic animals. The content of amino acidsin rat type I collagen was determined using an amino acid analyzer. Morphologicalanalyses of gonadic structures were carried out by an optic microscope. Results: Thestudy of the effects of diabetes on type I collagen amino acid content, testis cellsmorphologic and morphometric parameters and spermatogenesis demonstrated thepresence of diabetes-mediated quantitative and qualitative changes in male ratreproductive organs, spermatogenetic epithelial cells and extracellular matrixproteins in comparison with normal. Conclusions: Observed collagen moleculeschanges could hence affect the properties and correct functioning of spermatogeneticepithelium and of other tissues of reproductive organs. They could be caused bydiabetes via deficiency of insulin which is involved in collagen synthesis regulationat different stages of this process, cytochrome P450-2E1 induction and reactiveoxygen species effects on protein biosynthesis processes.
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132
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Sato J, Ishii Y, Noguchi H, Takeda M. Sonographic appearance of the flexor tendon, volar plate, and A1 pulley with respect to the severity of trigger finger. J Hand Surg Am 2012; 37:2012-20. [PMID: 22939830 DOI: 10.1016/j.jhsa.2012.06.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 06/22/2012] [Accepted: 06/22/2012] [Indexed: 02/02/2023]
Abstract
PURPOSE To evaluate trigger digits with sonography to determine morphological changes in the A1 pulley, flexor tendon, and volar plate in relation to the severity of triggering. METHODS We evaluated 67 trigger digits and graded them into 1 of 4 groups. We compared the groups according to severity and to contralateral fingers, which served as controls. RESULTS The thickness of the flexor tendons under the A1 pulley was proportional to the severity of triggering. The anteroposterior thickness of the flexor tendon increased significantly among the grades exhibiting triggering regardless of the affected digit. However, in digits other than the thumb, tendon thickness increased even in the absence of active triggering. Thickening tended to be greater with finger flexion. The A1 pulley exhibited the greatest thickness and the volar plate exhibited significant thickening in the group that exhibited continuous triggering that was easily reduced with active extension (grade III). CONCLUSIONS The flexor tendon thickened significantly before patients experienced triggering except in the thumb. In the thumb, the flexor tendon and A1 pulley thickened significantly only after patients exhibited triggering. Thickening of the volar plate appears to have an important role in continuous triggering. Although most clinicians can easily determine the severity of a trigger digit by clinical examination, ultrasound might be helpful for objectively understanding the severity and response to treatment, by examining the thickness of the flexor tendon and A1 pulley. In particular, sonographic measurement of the A1 pulley might be useful in judging the progression of trigger finger severity. In cases where a Doppler signal is detected inside the A1 pulley, more conservative therapies might be worth considering before surgery. TYPE OF STUDY/LEVEL OF EVIDENCE Diagnostic ΙΙΙ.
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Affiliation(s)
- Junko Sato
- Ishii Orthopaedic and Rehabilitation Clinic, Gyoda, Saitama, Japan.
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133
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Aït-Belkacem D, Guilbert M, Roche M, Duboisset J, Ferrand P, Sockalingum G, Jeannesson P, Brasselet S. Microscopic structural study of collagen aging in isolated fibrils using polarized second harmonic generation. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:080506-1. [PMID: 23224157 DOI: 10.1117/1.jbo.17.8.080506] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Polarization resolved second harmonic generation (PSHG) is developed to study, at the microscopic scale, the impact of aging on the structure of type I collagen fibrils in two-dimensional coatings. A ribose-glycated collagen is also used to mimic tissue glycation usually described as an indicator of aging. PSHG images are analyzed using a generic approach of the molecular disorder information in collagen fibrils, revealing significant changes upon aging, with a direct correlation between molecular disorder and fibril diameters.
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Affiliation(s)
- Dora Aït-Belkacem
- Aix-Marseille Université, Institut Fresnel, CNRS UMR 7249, Ecole Centrale, Marseille, Domaine Universitaire St. Jérôme, 13013 Marseille, France
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134
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Willett TL, Kandel R, De Croos JNA, Avery NC, Grynpas MD. Enhanced levels of non-enzymatic glycation and pentosidine crosslinking in spontaneous osteoarthritis progression. Osteoarthritis Cartilage 2012; 20:736-44. [PMID: 22469851 DOI: 10.1016/j.joca.2012.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 02/21/2012] [Accepted: 03/22/2012] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To test the hypothesis that heightened advanced glycation endproducts (AGEs) content in cartilage accelerates the progression of spontaneous osteoarthritis (OA) in the Hartley guinea pig (HGP) model. METHODS Twenty-eight male, 3-month-old HGPs were used. Eight were left untreated as a baseline control group and sacrificed at 3 months of age (n = 4) and 9 months of age (n = 4; age-matched controls). The other 20 HGPs received intra-articular knee injections in the right knee whereas the left knees acted as contra-lateral non-injected controls. Injections consisted of 100 μl phosphate buffered saline (PBS; n = 10) or PBS+2.0 M D-(-)-Ribose (n = 10). Injections were given once weekly for 24 weeks. At the end of the treatment period, the tibiae were fixed with formalin, scanned with microCT for sub-chondral bone mineral density, and then histological slides were prepared, stained with Safranin-O with Fast Green counter stain and scored using the OARSI-HISTOgp scheme. Cartilage pentosidine (established biomarker for AGEs) content, collagen content (% dry mass), glucosaminoglycan GAG-to-collagen ratio (μg/μg), GAG-to-DNA ratio and DNA-to-collagen ratio were measured. RESULTS Pentosidine content increased greatly due to PBS + Ribose injection (P < 0.0001) and reached levels found in cartilage from 80-year-old humans. Surprisingly, mean OARSI-HISTOgp scores for both the injected and contra-lateral controls in the PBS + Ribose group were not detectably different, nor were they different from the mean score for the age-matched control group. CONCLUSION AGEs accumulation due to intra-articular ribose-containing injections in the HGP model of spontaneous knee OA did not enhance disease progression.
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Affiliation(s)
- T L Willett
- Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Ontario, Canada.
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135
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Fessel G, Gerber C, Snedeker JG. Potential of collagen cross-linking therapies to mediate tendon mechanical properties. J Shoulder Elbow Surg 2012; 21:209-17. [PMID: 22244064 DOI: 10.1016/j.jse.2011.10.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 10/14/2011] [Indexed: 02/01/2023]
Abstract
Collagen cross-links are fundamental to the mechanical integrity of tendon, with orderly and progressive enzymatic cross-linking being central to healthy development and injury repair. However, the nonenzymatic cross-links that form as we age are associated with increased tendon brittleness, diminished mechanical resistance to injury, and impaired matrix remodeling. Collagen cross-linking thus sits at the center of tendon structure and function, with important implications to age, disease, injury, and therapy. The current review touches on these aspects from the perspective of their potential relevance to the shoulder surgeon. We first introduce the most well-characterized endogenous collagen cross-linkers that enable fibrillogenesis in development and healing. We also discuss the glycation-mediated cross-links that are implicated in age- and diabetes-related tendon frailty and summarize work toward therapies against these disadvantageous cross-links. Conversely, we discuss the introduction of exogenous collagen cross-links to augment the mechanical properties of collagen-based implants or native tendon tissue. We conclude with a summary of our early results using exogenous collagen cross-linkers to prevent tendon tear enlargement and eventual failure in an in vitro model of partial tendon tear.
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Affiliation(s)
- Gion Fessel
- Department of Orthopedics, University of Zurich, Zürich, Switzerland
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136
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Jürgensen HJ, Madsen DH, Ingvarsen S, Melander MC, Gårdsvoll H, Patthy L, Engelholm LH, Behrendt N. A novel functional role of collagen glycosylation: interaction with the endocytic collagen receptor uparap/ENDO180. J Biol Chem 2011; 286:32736-48. [PMID: 21768090 DOI: 10.1074/jbc.m111.266692] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Collagens make up the most abundant component of interstitial extracellular matrices and basement membranes. Collagen remodeling is a crucial process in many normal physiological events and in several pathological conditions. Some collagen subtypes contain specific carbohydrate side chains, the function of which is poorly known. The endocytic collagen receptor urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180 plays an important role in matrix remodeling through its ability to internalize collagen for lysosomal degradation. uPARAP/Endo180 is a member of the mannose receptor protein family. These proteins all include a fibronectin type II domain and a series of C-type lectin-like domains, of which only a minor part possess carbohydrate recognition activity. At least two of the family members, uPARAP/Endo180 and the mannose receptor, interact with collagens. The molecular basis for this interaction is known to involve the fibronectin type II domain but nothing is known about the function of the lectin domains in this respect. In this study, we have investigated a possible role of the single active lectin domain of uPARAP/Endo180 in the interaction with collagens. By expressing truncated recombinant uPARAP/Endo180 proteins and analyzing their interaction with collagens with high and low levels of glycosylation we demonstrated that this lectin domain interacts directly with glycosylated collagens. This interaction is functionally important because it was found to modulate the endocytic efficiency of the receptor toward highly glycosylated collagens such as basement membrane collagen IV. Surprisingly, this property was not shared by the mannose receptor, which internalized glycosylated collagens independently of its lectin function. This role of modulating its uptake efficiency by a specific receptor is a previously unrecognized function of collagen glycosylation.
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137
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138
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Cox TR, Erler JT. Remodeling and homeostasis of the extracellular matrix: implications for fibrotic diseases and cancer. Dis Model Mech 2011; 4:165-78. [PMID: 21324931 PMCID: PMC3046088 DOI: 10.1242/dmm.004077] [Citation(s) in RCA: 1069] [Impact Index Per Article: 82.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Dynamic remodeling of the extracellular matrix (ECM) is essential for development, wound healing and normal organ homeostasis. Life-threatening pathological conditions arise when ECM remodeling becomes excessive or uncontrolled. In this Perspective, we focus on how ECM remodeling contributes to fibrotic diseases and cancer, which both present challenging obstacles with respect to clinical treatment, to illustrate the importance and complexity of cell-ECM interactions in the pathogenesis of these conditions. Fibrotic diseases, which include pulmonary fibrosis, systemic sclerosis, liver cirrhosis and cardiovascular disease, account for over 45% of deaths in the developed world. ECM remodeling is also crucial for tumor malignancy and metastatic progression, which ultimately cause over 90% of deaths from cancer. Here, we discuss current methodologies and models for understanding and quantifying the impact of environmental cues provided by the ECM on disease progression, and how improving our understanding of ECM remodeling in these pathological conditions is crucial for uncovering novel therapeutic targets and treatment strategies. This can only be achieved through the use of appropriate in vitro and in vivo models to mimic disease, and with technologies that enable accurate monitoring, imaging and quantification of the ECM.
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Affiliation(s)
- Thomas R. Cox
- Cancer Research UK Tumour Cell Signalling Unit, Section of Cell and Molecular Biology, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Janine T. Erler
- Cancer Research UK Tumour Cell Signalling Unit, Section of Cell and Molecular Biology, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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139
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Willems NMBK, Mulder L, Bank RA, Grünheid T, den Toonder JMJ, Zentner A, Langenbach GEJ. Determination of the relationship between collagen cross-links and the bone-tissue stiffness in the porcine mandibular condyle. J Biomech 2011; 44:1132-6. [PMID: 21333996 DOI: 10.1016/j.jbiomech.2011.01.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 01/20/2011] [Accepted: 01/20/2011] [Indexed: 01/22/2023]
Abstract
Although bone-tissue stiffness is closely related to the degree to which bone has been mineralized, other determinants are yet to be identified. We, therefore, examined the extent to which the mineralization degree, collagen, and its cross-links are related to bone-tissue stiffness. A total of 50 cancellous and cortical bone samples were derived from the right mandibular condyles of five young and five adult female pigs. The degree of mineralization of bone (DMB) was assessed using micro-computed tomography. Using high-performance liquid chromatography, we quantified the collagen content and the number of cross-links per collagen molecule of two enzymatic cross-links: hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), and one non-enzymatic cross-link: pentosidine (Pen). Nanoindentation was used to assess bone-tissue stiffness in three directions, and multiple linear regressions were used to calculate the correlation between collagen properties and bone-tissue stiffness, with the DMB as first predictor. Whereas the bone-tissue stiffness of cancellous bone did not differ between the three directions of nanoindentation, or between the two age groups, cortical bone-tissue stiffness was higher in the adult tissue. After correction for DMB, the cross-links studied did not increase the explained variance. In the young group, however, LP significantly improved the explained variance in bone-tissue stiffness. Approximately half of the variation in bone-tissue stiffness in cancellous and cortical bone was explained by the DMB and the LP cross-links and thus they cannot be considered the sole determinants of the bone-tissue stiffness.
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Affiliation(s)
- Nop M B K Willems
- Department of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam, the Netherlands.
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140
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Abstract
Collagens are the most abundant proteins in mammals. The collagen family comprises 28 members that contain at least one triple-helical domain. Collagens are deposited in the extracellular matrix where most of them form supramolecular assemblies. Four collagens are type II membrane proteins that also exist in a soluble form released from the cell surface by shedding. Collagens play structural roles and contribute to mechanical properties, organization, and shape of tissues. They interact with cells via several receptor families and regulate their proliferation, migration, and differentiation. Some collagens have a restricted tissue distribution and hence specific biological functions.
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Affiliation(s)
- Sylvie Ricard-Blum
- Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS, Université Lyon 1, Lyon, 69367, France.
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141
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Chen XF, Lin WD, Lu SL, Xie T, Ge K, Shi YQ, Zou JJ, Liu ZM, Liao WQ. Mechanistic study of endogenous skin lesions in diabetic rats. Exp Dermatol 2010; 19:1088-95. [DOI: 10.1111/j.1600-0625.2010.01137.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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142
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Importance of syndecan-4 and syndecan -2 in osteoblast cell adhesion and survival mediated by a tissue transglutaminase-fibronectin complex. Exp Cell Res 2010; 317:367-81. [PMID: 21036168 DOI: 10.1016/j.yexcr.2010.10.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/23/2010] [Accepted: 10/16/2010] [Indexed: 11/20/2022]
Abstract
Tissue transglutaminase (TG2) has been identified as an important extracellular crosslinking enzyme involved in matrix turnover and in bone differentiation. Here we report a novel cell adhesion/survival mechanism in human osteoblasts (HOB) which requires association of FN bound TG2 with the cell surface heparan sulphates in a transamidase independent manner. This novel pathway not only enhances cell adhesion on FN but also mediates cell adhesion and survival in the presence of integrin competing RGD peptides. We investigate the involvement of cell surface receptors and their intracellular signalling molecules to further explore the pathway mediated by this novel TG-FN heterocomplex. We demonstrate by siRNA silencing the crucial importance of the cell surface heparan sulphate proteoglycans syndecan-2 and syndecan-4 in regulating the compensatory effect of TG-FN on osteoblast cell adhesion and actin cytoskeletal formation in the presence of RGD peptides. By use of immunoprecipitation and inhibitory peptides we show that syndecan-4 interacts with TG2 and demonstrate that syndecan-2 and the α5β1 integrins, but not α4β1 function as downstream modulators in this pathway. Using function blocking antibodies, we show activation of α5β1 occurs by an inside out signalling mechanism involving activation and binding of protein kinase PKCα and phosphorylation of focal adhesion kinase (FAK) at Tyr(861) and activation of ERK1/2.
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143
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Grant A, Trompf K, Seung D, Nivison-Smith L, Bowcock H, Kresse H, Holmes S, Radford J, Morrow P. Sub-cellular damage by copper in the cnidarian Zoanthus robustus. Comp Biochem Physiol C Toxicol Pharmacol 2010; 152:256-62. [PMID: 20462520 DOI: 10.1016/j.cbpc.2010.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Revised: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 11/26/2022]
Abstract
Sessile organisms may experience chronic exposure to copper that is released into the marine environment from antifoulants and stormwater runoff. We have identified the site of damage caused by copper to the symbiotic cnidarian, Zoanthus robustus (Anthozoa, Hexacorallia). External changes to the zoanthids were apparent when compared with controls. The normally flexible bodies contracted and became rigid. Histological examination of the zoanthid tissue revealed that copper had caused sub-cellular changes to proteins within the extracellular matrix (ECM) of the tubular body. Collagen in the ECM and the internal septa increased in thickness to five and seven times that of controls respectively. The epithelium, which stained for elastin, was also twice as thick and tough to cut, but exposure to copper did not change the total amount of desmosine which is found only in elastin. We conclude that copper stimulated collagen synthesis in the ECM and also caused cross-linking of existing proteins. However, there was no expulsion of the symbiotic algae (Symbiodinium sp.) and no effect on algal pigments or respiration (44, 66 and 110 microg Cu L(-1)). A decrease in net photosynthesis was observed only at the highest copper concentration (156 microg Cu L(-1)). These results show that cnidarians may be more susceptible to damage by copper than their symbiotic algae.
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Affiliation(s)
- A Grant
- School of Biological Sciences, Department of Pathology, University of Sydney, 2006, Australia.
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144
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Park CH, Noh JS, Yamabe N, Kang KS, Tanaka T, Yokozawa T. Beneficial effect of 7-O-galloyl-d-sedoheptulose on oxidative stress and hepatic and renal changes in type 2 diabetic db/db mice. Eur J Pharmacol 2010; 640:233-42. [DOI: 10.1016/j.ejphar.2010.04.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 03/26/2010] [Accepted: 04/19/2010] [Indexed: 02/06/2023]
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145
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Yuen A, Laschinger C, Talior I, Lee W, Chan M, Birek J, Young EW, Sivagurunathan K, Won E, Simmons CA, McCulloch C. Methylglyoxal-modified collagen promotes myofibroblast differentiation. Matrix Biol 2010; 29:537-48. [DOI: 10.1016/j.matbio.2010.04.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 04/13/2010] [Accepted: 04/15/2010] [Indexed: 01/09/2023]
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146
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Donaldson C, Taatjes DJ, Zile M, Palmer B, VanBuren P, Spinale F, Maughan D, Von Turkovich M, Bishop N, LeWinter MM. Combined immunoelectron microscopic and computer-assisted image analyses to detect advanced glycation end-products in human myocardium. Histochem Cell Biol 2010; 134:23-30. [PMID: 20490536 DOI: 10.1007/s00418-010-0706-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2010] [Indexed: 01/21/2023]
Abstract
Advanced glycation end-products (AGEs) result from oxidation-reduction reactions that ensue when a sugar becomes adducted to a protein. AGEs cause various complications of diabetes mellitus (DM). Experimental and clinical evidence suggest that AGEs also contribute to the complications of hypertension (HTN). Little is known about the abundance and localization of AGEs in human myocardium. In a few light microscopic studies, the AGE carboxymethyl lysine (CML) has been immunolabeled and localized virtually exclusively to the walls of small arteries. To more precisely delineate the abundance and localization of CML, we developed an immunoelectron microscopic (IEM) detection method using anti-CML monoclonal antibody 6D12 in conjunction with computer-assisted image analysis. Antibody was pre-absorbed with purified AGE-bovine serum albumin to assure specificity. Antigen-antibody (ag-ab) complexes were individually identified with protein A-conjugated colloidal gold and counted with an automated system. We applied this method in 21 patients (pts) undergoing epicardial biopsy during coronary bypass grafting (CBG) [20 M, 1 F; mean age 65 +/- 7.4 (+/- SEM) years]. Seven pts had neither DM nor HTN, seven had HTN, and seven had DM + HTN. In contrast to the prior light microscopic studies, we detected CML scattered throughout the cardiomyocyte in all pts, but in widely varying amounts. Ag-ab complexes were abundant in sections through myofilaments (mean count 23.6 +/- 9.2 per microm(2), range 9.4-48) and even more so in mitochondria (mean count 34.4 +/- 11.9 per microm(2), range 14.1-68.2, P < 0.001 vs. myofilaments). CML was also detected in vascular endothelial cells. There were no statistically significant differences based on presence or absence of HTN or DM. In conclusion, our IEM method is the first to provide detailed delineation of the localization and abundance of CML in myocardium. CML is very prevalent in CBG pts, suggesting that AGEs could play a role in abnormal cardiomyocyte function, including altered energy metabolism.
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Affiliation(s)
- Cameron Donaldson
- Department of Physiology and Biophysics, University of Vermont School of Medicine, Burlington, VT 05405, USA.
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147
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Koh S, Nakamura S, Hattori T, Hirata H. Trigger digits in diabetes: their incidence and characteristics. J Hand Surg Eur Vol 2010; 35:302-5. [PMID: 19687073 DOI: 10.1177/1753193409341103] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The purpose of this study was to investigate the incidence and characteristics of trigger digits in patients with diabetes. A questionnaire about trigger digit was completed by 544 patients with diabetes. Ten percent of the patients had a history of trigger digits and 4% had multiple digit involvement. The risk was significantly higher in insulin-dependent patients. The average duration of diabetes was significantly longer in the multiple digit group. Independently, the medical records of 132 trigger digit patients who underwent surgery were reviewed. Twenty-seven patients had diabetes, and 62 patients had multiple digit involvement. Involvement of more than three digits was significantly related to co-existing diabetes. In patients with diabetes, the incidence of trigger digits was about four times higher than in the general population. Screening for diabetes may be warranted in patients with involvement of more than three digits.
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Affiliation(s)
- S Koh
- Department of Hand Surgery, Nagoya University Graduate School of Medicine, Nagoya, Department of Orthopedic Surgery, Kakegawa City General Hospital, Kakegawa, Japan.
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148
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Willett TL, Labow RS, Aldous IG, Avery NC, Lee JM. Changes in Collagen With Aging Maintain Molecular Stability After Overload: Evidence From an In Vitro Tendon Model. J Biomech Eng 2010; 132:031002. [DOI: 10.1115/1.4000933] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Soft tissue injuries are poorly understood at the molecular level. Previous work using differential scanning calorimetry (DSC) has shown that tendon collagen becomes less thermally stable with rupture. However, most soft tissue injuries do not result in complete tissue rupture but in damaging fiber overextension. Covalent crosslinking, which increases with animal maturity and age, plays an important role in collagenous fiber mechanics. It is also a determinant of tissue strength and is hypothesized to inhibit the loss of thermal stability of collagen due to mechanical damage. Controlled overextension without rupture was investigated to determine if overextension was sufficient to reduce the thermal stability of collagen in the bovine tail tendon (BTT) model and to examine the effects of aging on the phenomenon. Baseline data from DSC and hydrothermal isometric tension (HIT) techniques were compared between two groups: steers aged 24–30 months (young group), and skeletally mature bulls and oxen aged greater than five years (old group). Covalent crosslinks were quantified by ion exchange chromatography. Overextension resulted in reduced collagen thermal stability in the BTT model. The Young specimens, showing detectably lower tissue thermomechanical competence, lost more thermal stability with overextension than did the old specimens. The effect on old specimens, while smaller, was detectable. Multiple overextension cycles increased the loss of stability in the young group. Compositional differences in covalent crosslinking corresponded with tissue thermomechanical competence and therefore inversely with the loss of thermal stability. HIT testing gave thermal denaturation temperatures similar to those measured with DSC. The thermal stability of collagen was reduced by overextension of the tendon—without tissue rupture—and this effect was amplified by increased cycles of overextension. Increased tissue thermomechanical competence with aging seemed to mitigate the loss of collagen stability due to mechanical overextension. Surprisingly, the higher tissue thermomechanical competence did not directly correlate with the concentration of endogenous enzymatically derived covalent crosslinking on a mole per mole of collagen basis. It did, however, correlate with the percentage of mature and thermally stable crosslinks. Compositional changes in fibrous collagens that occur with aging affect fibrous collagen mechanics and partially determine the nature of mechanical damage at the intermolecular level. As techniques develop and improve, this new information may lead to important future studies concerning improved detection, prediction, and modeling of mechanical damage at much finer levels of tissue hierarchy than currently possible.
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Affiliation(s)
- Thomas L. Willett
- Bone Biology Laboratory, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Rosalind S. Labow
- Department of Biochemistry, Microbiology and Immunology, Division of Cardiac Surgery, University of Ottawa Heart Institute, University of Ottawa, Ottawa, ON, K1Y 4W7, Canada
| | - Ian G. Aldous
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, B3M 3J5, Canada
| | - Nick C. Avery
- Matrix Biology Research Group, School of Clinical Veterinary Medicine, University of Bristol, Bristol BS40 5DU, UK
| | - J. Michael Lee
- Department of Applied Oral Sciences, School of Biomedical Engineering, Dalhousie University, Halifax, NS, B3H 3J5, Canada
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149
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Negre-Salvayre A, Salvayre R, Augé N, Pamplona R, Portero-Otín M. Hyperglycemia and glycation in diabetic complications. Antioxid Redox Signal 2009; 11:3071-109. [PMID: 19489690 DOI: 10.1089/ars.2009.2484] [Citation(s) in RCA: 260] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Diabetes mellitus is a multifactorial disease, classically influenced by genetic determinants of individual susceptibility and by environmental accelerating factors, such as lifestyle. It is considered a major health concern,as its incidence is increasing at an alarming rate, and the high invalidating effects of its long-term complications affect macro- and microvasculature, heart, kidney, eye, and nerves. Increasing evidence indicates that hyperglycemia is the initiating cause of the tissue damage occurring in diabetes, either through repeated acute changes in cellular glucose metabolism, or through the long-term accumulation of glycated biomolecules and advanced glycation end products (AGEs). AGEs represent a heterogeneous group of chemical products resulting from a nonenzymatic reaction between reducing sugars and proteins, lipids, nucleic acids, or a combination of these.The glycation process (glucose fixation) affects circulating proteins (serum albumin, lipoprotein, insulin, hemoglobin),whereas the formation of AGEs implicates reactive intermediates such as methylglyoxal. AGEs form cross-links on long-lived extracellular matrix proteins or react with their specific receptor RAGE, resulting inoxidative stress and proinflammatory signaling implicated in endothelium dysfunction, arterial stiffening, and microvascular complications. This review summarizes the mechanism of glycation and of AGEs formation and the role of hyperglycemia, AGEs, and oxidative stress in the pathophysiology of diabetic complications.
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150
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Ren L, Fu Y, Deng Y, Qi L, Jin L. Advanced glycation end products inhibit the expression of collagens type I and III by human gingival fibroblasts. J Periodontol 2009; 80:1166-73. [PMID: 19563298 DOI: 10.1902/jop.2009.080669] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND It is evident that diabetes and periodontal disease are closely interrelated. Accumulation of advanced glycation end products (AGEs), coupled with exaggerated host responses to bacterial infection, may account for the increased periodontal destruction observed in patients with uncontrolled diabetes. The present study investigated the effects of AGEs on the viability of human gingival fibroblasts (HGFs) and the expression of types I and III collagen in HGFs. METHODS The cell viability of HGFs was examined by methylthiazolet-etrazolium assay, whereas the expression of types I and III collagen message and protein was detected by real-time quantitative reverse transcription-polymerase chain reaction and sandwich enzyme-linked immunosorbent assay, respectively. RESULTS AGEs significantly suppressed the cell viability of HGFs from 24 to 72 hours (P <0.01). A high concentration of glucose (25 mmol/l) in the culture media exaggerated the inhibition of the survival rate of HGFs (P <0.01). The expression of collagen types I and III messages and proteins was significantly downregulated at 72 hours by AGEs in a concentration-dependent manner (P <0.05). Moreover, the synthesis of intracellular types I and III collagen protein was markedly inhibited by AGEs (P <0.05). CONCLUSIONS AGEs may suppress the cell viability of HGFs and downregulate the expression of types I and III collagen by the cells. Further investigations are warranted to clarify the molecular mechanisms of AGEs in the regulation of cell function and collagen metabolism in patients with diabetes and periodontitis.
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Affiliation(s)
- Lei Ren
- Department of Periodontology, Institute of Stomatological Research, Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, China
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