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Yañez AJ, Jaramillo K, Blaña C, Burgos RA, Isla A, Silva P, Aguilar M. Sodium Tungstate (NaW) Decreases Reactive Oxygen Species (ROS) Production in Cells: New Cellular Antioxidant. Biomedicines 2023; 11:biomedicines11020417. [PMID: 36830953 PMCID: PMC9953222 DOI: 10.3390/biomedicines11020417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of end-stage renal failure worldwide. Hyperglycemia generates reactive oxygen species (ROS), contributing to diabetic complications, especially in DN. Sodium Tungstate (NaW) is an effective antidiabetic agent for short and long-term treatments of both type 1 and type 2 diabetes models. In this study, we evaluated the effect of NaW on ROS production in bovine neutrophils incubated with platelet-activating factor (PAF) and in HK-2 cells induced by high glucose or H2O2. In addition, we evaluated the effect on iNOS expression in the type 1 diabetic rat model induced with streptozotocin (STZ). NaW inhibited ROS production in PAF-induced bovine neutrophils, and human tubular cells (HK-2) were incubated in high glucose or H2O2. In addition, NaW inhibited iNOS expression in glomeruli and tubular cells in the type 1 diabetic rat. This study demonstrates a new role for NaW as an active antioxidant and its potential use in treating DN.
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Affiliation(s)
- Alejandro J. Yañez
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad de Concepción, Concepción 4030000, Chile
- Correspondence: (A.J.Y.); (M.A.)
| | - Karen Jaramillo
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Camila Blaña
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Rafael A. Burgos
- Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, UACH Campus Isla Teja, Valdivia 5090000, Chile
| | - Adolfo Isla
- Interdisciplinary Center for Aquaculture Research (INCAR), Universidad de Concepción, Concepción 4030000, Chile
- Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia 5090000, Chile
| | - Pamela Silva
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Marcelo Aguilar
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile
- Correspondence: (A.J.Y.); (M.A.)
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Khanal P, Patil BM. Gene ontology enrichment analysis of α-amylase inhibitors from Duranta repens in diabetes mellitus. J Diabetes Metab Disord 2020; 19:735-747. [PMID: 33520800 DOI: 10.1007/s40200-020-00554-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/05/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022]
Abstract
Background Although α-amylase is the choice of target to manage postprandial hyperglycemia, inhibitors of this enzyme may get absorbed into the systemic circulation and modulate proteins involved in the pathogenesis of diabetes mellitus. Hence, the present study aimed to identify α-amylase inhibitors from Duranta repens via in silico and in vitro and predict their role in the modulation of multiple pathways involved in diabetes mellitus. Methods α-amylase inhibitory activity of hydroalcoholic extract/fractions (s) and pure compounds from D. repens was performed using in vitro enzyme inhibitory assay. Multiple open-source databases and published literature were used to retrieve reported phytoconstituents present in D. repens and their targets. The network was constructed between α-amylase inhibitors, modulated proteins, and expressed pathways. Further, hit molecules were also confirmed for their potency to inhibit α-amylase using in silico molecular docking and in vitro enzyme inhibitory assay. The glucose uptake assay was performed to assess the effect of hydrolcoholic extract/fraction(s) using rat hemidiaphragm. Results Fraction rich in flavonoids showed the highest α-amylase inhibitory activity with a IC50 of 644.29 ± 4.36 µg/ml compared to other fractions. PI3K-Akt signaling pathway and p53 signaling pathway were predicted to be primarily modulated in the compound-protein-pathway network. Similarly, scutellarein was predicted as lead hit based on α-amylase inhibitory action, binding affinity, and regulated pathways. Further, α-amylase inhibitors were also predicted to modulate the pathways involved in diabetes complications like AGE-RAGE and FoxO signaling pathway. Fraction rich in flavonoids showed the highest glucose uptake in rat hemidiaphragm with an effective concentration of 534.73 ± 0.79 µg/ml. Conclusions The α-amylase inhibitors from D. repens may not be limited within the gastrointestinal tract to inhibit α-amylase but may get absorbed into the systemic circulation and modulate multiple pathways involved in the pathogenesis of diabetes mellitus to produce synergistic/additive effect.
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Affiliation(s)
- Pukar Khanal
- Department of Pharmacology and Toxicology, KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research (KAHER), Belagavi, 590010 India
| | - B M Patil
- Department of Pharmacology and Toxicology, KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research (KAHER), Belagavi, 590010 India
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Han W, Wang C, Yang Z, Mu L, Wu M, Chen N, Du C, Duan H, Shi Y. SRT1720 retards renal fibrosis via inhibition of HIF1α /GLUT1 in diabetic nephropathy. J Endocrinol 2019; 241:JOE-18-0536.R2. [PMID: 30798323 DOI: 10.1530/joe-18-0536] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 02/22/2019] [Indexed: 12/17/2022]
Abstract
Renal fibrosis is a major pathological characteristic of diabetic nephropathy (DN). Reportedly, increased SIRT1 expression played a renal protective role in animal models of DN. This study was designed to elucidate the molecular mechanisms underlying the protective effects of SRT1720, an SIRT1 activator, against diabetes-induced renal fibrosis. Type 2 diabetic mice (db/db) were treated with SRT1720 (50 mg/kg/d) by gavage for 10 weeks. Renal proximal tubular epithelial cells (HK-2 cells) were treated with high glucose (HG, 30 mM) in the presence or absence of SRT1720 (2.5 µM) for 48 h. We observed that impaired SIRT1 expression and activity were restored by SRT1720 administration in db/db mice as well as in HG-treated HK-2 cells. Moreover, SRT1720 administration improved renal function, attenuated glomerular hypertrophy, mesangial expansion, glomerulosclerosis and interstitial fibrosis, and inhibited TGFB1 and CTGF expressions and nuclear factor κB (NF-κB) activation in db/db mice. Similarly, HG-induced epithelial-to-mesenchymal transformation (EMT), and collagen IV and fibronectin expressions were inhibited in SRT1720 treated HK-2 cells. Mechanistic studies demonstrated that SRT1720 suppressed HIF1α, GLUT1 and SNAIL expressions both in vivo and in vitro. Furthermore, Hif1α or Glut1 knockdown effectively abrogated HG-induced EMT and collagen IV and fibronectin expressions in HK-2 cells. These findings suggest that SRT1720 prevented diabetes-induced renal fibrosis via the SIRT1/HIF1α/GLUT1/SNAIL pathway.
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Affiliation(s)
- Weixia Han
- W Han, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Chen Wang
- C Wang, Department of Pathology, Shanxi Medical University Second Affiliated Hospital, Taiyuan, China
| | - Zhifen Yang
- Z Yang, Department of pathology , Hebei Medical University, Shijiazhuang City, China
| | - Lin Mu
- L Mu, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Ming Wu
- M Wu, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Nan Chen
- N Chen, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Chunyang Du
- C Du, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Huijun Duan
- H Duan, Department of Pathology, Hebei Medical University, Shijiazhuang City, China
| | - Yonghong Shi
- Y Shi, Department of Pathology, Hebei Medical University, Shijiazhuang City, 050017, China
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Stefanidis I, Tziastoudi M, Tsironi EE, Dardiotis E, Tachmitzi SV, Fotiadou A, Pissas G, Kytoudis K, Sounidaki M, Ampatzis G, Mertens PR, Liakopoulos V, Eleftheriadis T, Hadjigeorgiou GM, Santos M, Zintzaras E. The contribution of genetic variants of SLC2A1 gene in T2DM and T2DM-nephropathy: association study and meta-analysis. Ren Fail 2018; 40:561-576. [PMID: 30353771 PMCID: PMC6201811 DOI: 10.1080/0886022x.2018.1496931] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 06/15/2018] [Accepted: 06/28/2018] [Indexed: 12/22/2022] Open
Abstract
An association study was conducted to investigate the relation between 14 variants of glucose transporter 1 gene (SLC2A1) and the risk of type 2 diabetes (T2DM) leading to nephropathy. We also performed a meta-analysis of 11 studies investigating association between diabetic nephropathy (DN) and SLC2A1 variants. The cohort included 197 cases (T2DM with nephropathy), 155 diseased controls (T2DM without nephropathy) and 246 healthy controls. The association of variants with disease progression was tested using generalized odds ratio (ORG). The risk of type 2 diabetes leading to nephropathy was estimated by the OR of additive and co-dominant models. The mode of inheritance was assessed using the degree of dominance index (h-index). We synthesized results of 11 studies examining association between 5 SLC2A1 variants and DN. ORG was used to assess the association between variants and DN using random effects models. Significant results were derived for co-dominant model of rs12407920 [OR = 2.01 (1.17-3.45)], rs841847 [OR = 1.73 (1.17-2.56)] and rs841853 [OR = 1.74 (1.18-2.55)] and for additive model of rs3729548 [OR = 0.52 (0.29-0.90)]. The mode of inheritance for rs12407920, rs841847 and rs841853 was 'dominance of each minor allele' and for rs3729548 'non-dominance'. Frequency of one haplotype (C-G-G-A-T-C-C-T-G-T-C-C-A-G) differed significantly between cases and healthy controls [p = .014]. Regarding meta-analysis, rs841853 contributed to an increased risk of DN [(ORG = 1.43 (1.09-1.88); ORG = 1.58 (1.01-2.48)] between diseased controls versus cases and healthy controls versus cases, respectively. Further studies confirm the association of rs12407920, rs841847, rs841853, as well as rs3729548 and the risk of T2DM leading to nephropathy.
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Affiliation(s)
- I. Stefanidis
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - M. Tziastoudi
- Department of Biomathematics, University of Thessaly School of Medicine, Larissa, Greece
| | - E. E. Tsironi
- Department of Ophthalmology, University of Thessaly School of Medicine, Larissa, Greece
| | - E. Dardiotis
- Department of Neurology, University of Thessaly School of Medicine, Larissa, Greece
| | - S. V. Tachmitzi
- Department of Ophthalmology, University of Thessaly School of Medicine, Larissa, Greece
| | - A. Fotiadou
- Department of Ophthalmology, University of Thessaly School of Medicine, Larissa, Greece
| | - G. Pissas
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - K. Kytoudis
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - M. Sounidaki
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - G. Ampatzis
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - P. R. Mertens
- Department of Nephrology, Hypertension, Diabetes and Endocrinology, School of Medicine, University of Magdeburg, Magdeburg, Germany
| | - V. Liakopoulos
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - T. Eleftheriadis
- Department of Nephrology, University of Thessaly School of Medicine, Larissa, Greece
| | - G. M Hadjigeorgiou
- Department of Neurology, University of Thessaly School of Medicine, Larissa, Greece
| | - M. Santos
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - E. Zintzaras
- Department of Biomathematics, University of Thessaly School of Medicine, Larissa, Greece
- The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
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Effect of yerba mate (Ilex paraguariensis) extract on the metabolism of diabetic rats. Biomed Pharmacother 2018; 105:370-376. [PMID: 29864625 DOI: 10.1016/j.biopha.2018.05.132] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/28/2018] [Accepted: 05/28/2018] [Indexed: 01/11/2023] Open
Abstract
The relationship between metabolic disturbances and clinical events related to diabetes is well known. Yerba mate has presented a potential use as preventive and therapeutic agent on diabetes. The aim of this study was to evaluate the effect of yerba mate on different tissues of diabetic rats, focusing on energetic metabolism. Diabetes was induced by streptozotocin, followed by daily yerba mate treatment. After 30 days, the animals were euthanized to evaluate metabolic parameters on liver, adipose tissue, muscle and serum. The results showed mate treatment promoted a decrease in retroperitoneal adipose tissue in healthy animals. Muscle weight returned to control levels in diabetic rats treated with mate. There was improvement on serum glucose, creatinine, urea and total protein levels associated with mate treatment. Muscle parameters, such as glucose uptake and carbon dioxide production, were improved by mate treatment to control levels. The results evidenced the beneficial actions mate can have on metabolic disturbances of diabetes.
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Nayak BK, Shanmugasundaram K, Friedrichs WE, Cavaglierii RC, Patel M, Barnes J, Block K. HIF-1 Mediates Renal Fibrosis in OVE26 Type 1 Diabetic Mice. Diabetes 2016; 65:1387-97. [PMID: 26908870 PMCID: PMC4839204 DOI: 10.2337/db15-0519] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 01/19/2016] [Indexed: 12/19/2022]
Abstract
Hypoxia-inducible factor (HIF)-1 mediates hypoxia- and chronic kidney disease-induced fibrotic events. Here, we assessed whether HIF-1 blockade attenuates the manifestations of diabetic nephropathy in a type 1 diabetic animal model, OVE26. YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole], an HIF-1 inhibitor, reduced whole kidney glomerular hypertrophy, mesangial matrix expansion, extracellular matrix accumulation, and urinary albumin excretion as well as NOX4 protein expression and NADPH-dependent reactive oxygen species production, while blood glucose levels remained unchanged. The role of NOX oxidases in HIF-1-mediated extracellular matrix accumulation was explored in vitro using glomerular mesangial cells. Through a series of genetic silencing and adenoviral overexpression studies, we have defined GLUT1 as a critical downstream target of HIF-1α mediating high glucose-induced matrix expression through the NADPH oxidase isoform, NOX4. Together, our data suggest that pharmacological inhibition of HIF-1 may improve clinical manifestations of diabetic nephropathy.
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Affiliation(s)
- Bijaya K Nayak
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | | | - William E Friedrichs
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Rita C Cavaglierii
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Mandakini Patel
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Jeffrey Barnes
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX Audie L. Murphy Memorial VA Hospital Division, South Texas Veterans Health Care System, San Antonio, TX
| | - Karen Block
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX Audie L. Murphy Memorial VA Hospital Division, South Texas Veterans Health Care System, San Antonio, TX
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Alvarez ML, DiStefano JK. Towards microRNA-based therapeutics for diabetic nephropathy. Diabetologia 2013; 56:444-56. [PMID: 23135222 DOI: 10.1007/s00125-012-2768-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/09/2012] [Indexed: 12/23/2022]
Abstract
There is no cure for diabetic nephropathy and the molecular mechanisms underlying disease aetiology remain poorly understood. While current paradigms for clinical management of diabetic nephropathy are useful in delaying disease onset and preventing its progression, they do not do so for a significant proportion of diabetic individuals, who eventually end up developing renal failure. Thus, novel therapeutic targets are needed for the treatment and prevention of the disease. MicroRNAs (miRNAs), a class of non-coding RNAs that negatively regulate gene expression, have recently been identified as attractive targets for therapeutic intervention. It is widely recognised that dysregulation of miRNA expression or action contributes to the development of a number of different human diseases, and evidence of a role for miRNAs in the aetiology of diabetic nephropathy is emerging. The discovery that modulation of miRNA expression in vivo is feasible, combined with recent results from successful clinical trials using this technology, opens the way for future novel therapeutic applications. For instance, inhibition of miRNAs that are commonly upregulated in diabetic nephropathy decreases albuminuria and mesangial matrix accumulation in animal models, suggesting that a therapeutic agent against these molecules may help to prevent the development of diabetic nephropathy. Certain challenges, including the development of safe and reliable delivery systems, remain to be overcome before miRNA-based therapeutics become a reality. However, the findings accumulated to date, in conjunction with newly emerging results, are expected to yield novel insights into the complex pathogenesis of diabetic nephropathy, and may eventually lead to the identification of improved therapeutic targets for treatment of this disease.
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Affiliation(s)
- M L Alvarez
- Diabetes, Cardiovascular and Metabolic Diseases Division, Translational Genomics Research Institute, 445 North Fifth St, Phoenix, AZ 85004, USA
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Buller CL, Heilig CW, Brosius FC. GLUT1 enhances mTOR activity independently of TSC2 and AMPK. Am J Physiol Renal Physiol 2011; 301:F588-96. [PMID: 21613414 PMCID: PMC3174561 DOI: 10.1152/ajprenal.00472.2010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 05/24/2011] [Indexed: 01/28/2023] Open
Abstract
Enhanced GLUT1 expression in mesangial cells plays an important role in the development of diabetic nephropathy by stimulating signaling through several pathways resulting in increased glomerular matrix accumulation. Similarly, enhanced mammalian target of rapamycin (mTOR) activation has been implicated in mesangial matrix expansion and glomerular hypertrophy in diabetes. We sought to examine whether enhanced GLUT1 expression increased mTOR activity and, if so, to identify the mechanism. We found that levels of GLUT1 expression and mTOR activation, as evidenced by S6 kinase (S6K) and 4E-BP-1 phosphorylation, changed in tandem in cell lines exposed to elevated levels of extracellular glucose. We then showed that increased GLUT1 expression enhanced S6K phosphorylation by 1.7- to 2.9-fold in cultured mesangial cells and in glomeruli from GLUT1 transgenic mice. Treatment with the mTOR inhibitor, rapamycin, eliminated the GLUT1 effect on S6K phosphorylation. In cells lacking functional tuberous sclerosis complex (TSC) 2, GLUT1 effects on mTOR activity persisted, indicating that GLUT1 effects were not mediated by TSC. Similarly, AMP kinase activity was not altered by enhanced GLUT1 expression. Conversely, enhanced GLUT1 expression led to a 2.4-fold increase in binding of mTOR to its activator, Rheb, and a commensurate 2.1-fold decrease in binding of Rheb to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) consistent with mediation of GLUT1 effects by a metabolic effect on GAPDH. Thus, GLUT1 expression appears to augment mesangial cell growth and matrix protein accumulation via effects on glycolysis and decreased GAPDH interaction with Rheb.
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Affiliation(s)
- Carolyn L Buller
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, USA
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10
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Sulkowska M, Wincewicz A, Sulkowski S, Koda M, Kanczuga-Koda L. Relations of TGF-beta1 with HIF-1 alpha, GLUT-1 and longer survival of colorectal cancer patients. Pathology 2009; 41:254-60. [PMID: 19142800 DOI: 10.1080/00313020802579318] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
AIMS AND METHODS During colorectal carcinogenesis, transforming growth factor beta 1 (TGF-beta1) undergoes a functional change from suppression of cancer cell proliferation to inhibition of T cell mediated anti-cancer immunity. We aimed to evaluate relations among TGF-beta1 and cancer cell survival factors hypoxia inducible factor-1 alpha (HIF-1 alpha) and glucose transporter 1 (GLUT-1) by immunohistochemistry in 108 colorectal cancers. RESULTS TGF-beta1 was detected in 87% (94/108), HIF-1 alpha in 85% (92/108), and GLUT-1 in 65% (70/108) of colorectal cancers. Not only did TGF-beta1 accumulate in cytoplasm of cancer cells but also there was strong immunoreactivity to TGF-beta1 in adjacent inflammatory cells. GLUT-1 was visualised in a membranous fashion while HIF-1 was expressed in a paranuclear pattern and occasionally in nuclei of malignant cells. Cancer immunoreactivities to TGF-beta1 correlated with HIF-1 alpha (p < 0.001, r = 0.516) and GLUT-1 (p < [corrected] 0.001, r = 0.355) in general and subgroups of different clinicopathological traits. TGF-beta1 expressions of inflammatory infiltrates correlated with longer patient survival (p = 0.05, r = 0.449) and immunoreactivities to HIF-1 alpha of cancer cells (p = 0.008, r = 0.254) particularly in node positive and deeply invading cancers but failed to associate significantly with GLUT-1. CONCLUSIONS HIF-1 alpha and GLUT-1 could cooperate with TGF-beta1, and TGF-beta1 might mediate cross-talk between the inflammatory environment and tumour with a favourable impact on patient survival.
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Affiliation(s)
- Mariola Sulkowska
- Department of General Pathomorphology, Medical University of Bialystok, Bialystok, Poland
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Moutzouris DAD, Kitsiou PV, Talamagas AA, Drossopoulou GI, Kassimatis TI, Katsilambros NK. Chronic Exposure of Human Glomerular Epithelial Cells to High Glucose Concentration Results in Modulation of High-Affinity Glucose Transporters Expression. Ren Fail 2009; 29:353-8. [PMID: 17497451 DOI: 10.1080/08860220601184126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
INTRODUCTION GLUTs are specific membrane proteins that transport glucose down a concentration gradient. There have been few studies on their expression in the kidney. The aim of this study was to identify the expression of GLUTs 1, 3, and 4 in HGEC and their regulation under diabetic milieu. MATERIAL AND METHODS An immortalized cell line of HGEC was used. Cells were cultured in medium containing 5 or 25 mM D-glucose. Western blotting and flow cytometry were used to examine the presence of GLUTs (1, 3, 4) and alterations in expression. RESULTS Western blotting analysis revealed that GLUT-1 levels were increased by 53% in HGEC cultured under experimental diabetes compared to cells grown in 5mM glucose. GLUT-3 levels were also increased by 15% under diabetic conditions. GLUT-4 levels were decreased by 20% in diabetes. Fluorescence Activated Cell Sorting (FACS) analysis demonstrated that cell surface expression of GLUT-1 was increased by 28% in cells grown in 25mM glucose. High glucose concentration did not affect cell surface expression of GLUT-3 and GLUT-4. DISCUSSION These findings suggest that depressed GLUT4 expression in glomerulus and overexpression of GLUT-1 and in a lesser extent of GLUT-3 may alter the glucose uptake in these cells. It has been suggested that the overexpression of GLUT-1 in glomerulus, being the major isoform, may lead to the initial pathologic hallmarks of diabetic nephropathy.
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Affiliation(s)
- Dimitrios-Anestis D Moutzouris
- First Department of Propaedeutic Medicine, University of Athens Medical School, Laiko University Hospital, Athens, Greece.
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Ziyadeh FN. Different roles for TGF-beta and VEGF in the pathogenesis of the cardinal features of diabetic nephropathy. Diabetes Res Clin Pract 2008; 82 Suppl 1:S38-41. [PMID: 18842317 DOI: 10.1016/j.diabres.2008.09.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hemodynamic stress in concert with metabolic pathways that are activated by hyperglycemia, glycated proteins, and oxidative stress induce a host of growth factors in the kidney. The fibrogenic cytokine transforming growth factor-beta (TGF-beta), through its Smad3 signaling pathway, is the etiologic agent of renal hypertrophy and the accumulation of mesangial extracellular matrix components in diabetes. Neutralizing anti-TGF-beta antibodies, antisense TGF-beta1 oligodeoxynucleotides or knocking off the Smad3 gene prevent and/or reverse the hypertrophic and profibrotic effects of the diabetic state in mice. However, there is limited evidence to support a role for TGF-beta in the development of albuminuria. Podocyte-derived vascular endothelial growth factor (VEGF), a permeability and angiogenic factor whose expression is also increased in animal models of diabetic kidney disease, appears to act in a novel autocrine signaling mode to induce the podocytopathy of diabetes, especially the genesis of albuminuria. Future strategies for therapy of diabetic nephropathy may therefore need to involve interception of both the TGF-beta and the VEGF signaling pathways to counter the matrix accumulation and to improve the albuminuria. Interception of the renin-angiotensin system may achieve this goal but other novel strategies will need to be developed that would be more efficacious. However, a note of caution should be raised not to lower the heightened activities of these two signaling pathways much below normal levels because a basal activity for each is essential for the optimal homeostasis of glomerular cells.
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Affiliation(s)
- Fuad N Ziyadeh
- Departments of Internal Medicine and Biochemistry, Faculty of Medicine, American University of Beirut, Bliss Street, Beirut, Lebanon.
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Schmid H, Bertoluci M, Coimbra TM. Glucose transporter 12 and mammalian target of rapamycin complex 1 signaling: a new target for diabetes-induced renal injury? Endocrinology 2008; 149:913-6. [PMID: 18292201 DOI: 10.1210/en.2007-1707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Helena Schmid
- Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Programa de Pós-Graduação em Ciências Médicas, Santa Casa de Porto Alegre, Professor Annes Dias, 285, Porto Alegre, Brasil 90020090.
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Ujpál M, Barabás J, Kovalszky I, Szabó G, Németh Z, Gábris K, Suba Z. A preliminary comparative study of the prognostic implications of type 2 diabetes mellitus for patients with primary gingival carcinoma treated with surgery and radiation therapy. J Oral Maxillofac Surg 2007; 65:452-6. [PMID: 17307592 DOI: 10.1016/j.joms.2006.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 06/26/2006] [Accepted: 09/27/2006] [Indexed: 01/01/2023]
Abstract
PURPOSE Type 2 diabetes mellitus (DM2) may be a risk factor in determining cancer progression. The aim of this study was to compare the progression of primary gingival cancer in patients with DM2 and nondiabetic patients. PATIENTS AND METHODS Prospective follow-up studies involved patients with gingival squamous cell carcinoma in stage T2-3N0M0. Treatment comprised surgical tumor extirpation, block resection of the mandible, functional cervical dissection, and 60 Gy of adjuvant irradiation. The patients were divided into a group of patients with DM2 (DM group) and a nondiabetic, control group. Progression data was recorded after a 2-year period of clinical follow-up. Surgical samples were assessed histopathologically from the aspect of tumor spread. RESULTS At the end of a 2-year follow-up period, the DM group demonstrated significantly worse clinical results in terms of cervical lymph node metastases (P<.05) and mortality rate (P<.001). Histologically, the degree of tumor invasion was significantly different in the DM group and controls (P<.01). CONCLUSION DM2 can be considered a possible prognostic factor in cases of gingival carcinoma, forecasting an unfavorable course.
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Affiliation(s)
- Márta Ujpál
- Department of Oral and Maxillofacial Surgery, Semmelweis University, Budapest, Hungary
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15
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Ramachandra Rao SP, Wassell R, Shaw MA, Sharma K. Profiling of human mesangial cell subproteomes reveals a role for calmodulin in glucose uptake. Am J Physiol Renal Physiol 2007; 292:F1182-9. [PMID: 17200159 DOI: 10.1152/ajprenal.00268.2006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Proteomics combined with cell fractionation was used to identify proteins regulated by high glucose (HG) in human mesangial cells (HMC). Total membrane and cytosolic fraction proteins derived from HMC after 7 days of HG exposure were resolved by a two-dimensional gel electrophoresis approach. DeCyder software was used to analyze the HG-induced protein spot dysregulation. In the membrane subproteome, of the 92 spots that were matched across all gels, HG induced significant downregulation of only 4 protein spots. The dysregulated spots from the membrane subproteome included binding protein (BiP), calreticulin precursor protein, a 63-kDa transmembrane protein from a ER/Golgi intermediate, and beta-subunit of collagen proline 4-hydroxylase. In the cytosolic subproteome, of the 122 spots that were matched across all gels, HG induced downregulation of 3 protein spots and upregulation of 2 protein spots significantly. Enolase 1, annexin VI, and gamma(2)-actin were decreased, whereas heat shock protein-70 kDa and calmodulin (CaM) were increased. Further confocal microscopy and Western immunoblotting of mesangial cells validated the increase in CaM. Immunoblotting of diabetic mouse and rat kidneys exhibited a marked increase in CaM at both early and late stages of diabetes, reflecting the potential physiological relevance of CaM upregulation. CaM-specific inhibitors blocked glucose transport stimulated by transforming growth factor-beta and insulin in mesangial cells. In conclusion, using a combination of cell fractionation and protein expression profiling, we identified a cohort of HG-dysregulated proteins in the HMC and identified a critical and as yet unrecognized role for CaM in glucose transport in mesangial cells.
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Affiliation(s)
- Satish P Ramachandra Rao
- Dept. of Medicine, Center for Novel Therapies for Kidney Disease, Suite 365 Jefferson Alumni Hall, 1020 Locust St., Philadelphia, PA 19107, USA.
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16
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Hsieh CH, Liang KH, Hung YJ, Huang LC, Pei D, Liao YT, Kuo SW, Bey MSJ, Chen JL, Chen EY. Analysis of epistasis for diabetic nephropathy among type 2 diabetic patients. Hum Mol Genet 2006; 15:2701-8. [PMID: 16893912 DOI: 10.1093/hmg/ddl203] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Diabetic nephropathy (DN) is one of the most serious complications of diabetes, accounting for the majority of patients with end-stage renal disease. The molecular pathogenesis of DN involves multiple pathways in a complex, partially resolved manner. The paper presents an exploratory epistatic study for DN. Association analysis were performed on 231 SNP loci in a cohort of 264 type 2 diabetes patients, followed by the epistasis analysis using the multifactor dimensionality reduction and the genetic algorithm with Boolean algebra. A two-locus epistatic effect of EGFR and RXRG was identified, with a cross-validation consistency of 91.7%.
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Affiliation(s)
- Chang-Hsun Hsieh
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, Taipei, Taiwan
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17
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Ricci C, Iacobini C, Oddi G, Amadio L, Menini S, Rastaldi MP, Frasheri A, Pricci F, Pugliese F, Pugliese G. Role of TGF-β/GLUT1 axis in susceptibility vs resistance to diabetic glomerulopathy in the Milan rat model. Nephrol Dial Transplant 2006; 21:1514-24. [PMID: 16449286 DOI: 10.1093/ndt/gfk089] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND GLUT1 upregulation and increased glucose transport activity may contribute to extracellullar matrix (ECM) accumulation characterizing diabetic nephropathy (DN). Rats of the Milan hypertensive strain (MHS) are resistant to both hypertensive and diabetic renal disease, due to a haemodynamic protection. On the contrary, those of the Milan normotensive strain (MNS) develop spontaneous glomerulosclerosis, and when rendered diabetic, show typical morphological and haemodynamic changes. METHODS To assess whether susceptibility to diabetic glomerulopathy in MNS rats is associated with higher glucose transporter 1 (GLUT1) expression (and glucose transport activity) vs MHS rats, diabetic and nondiabetic MNS and MHS rats were followed for 6 months and mesangial cells derived from these animals were exposed to high glucose (HG) vs normal glucose (NG) conditions. RESULTS Glomerular expression of GLUT1 protein and ECM and transforming growth factor-beta (TGF-beta) mRNA was significantly upregulated in diabetic vs nondiabetic MNS, but not MHS rats. Upon exposure to HG and/or TGF-beta, mesangial cells from 1- and 8-month-old MNS rats showed higher glucose transport activity and GLUT1 membrane expression than those from age-matched MHS rats. Likewise, ECM and TGF-beta production increased more markedly in response to HG and/or TGF-beta in MNS vs MHS mesangial cells. CONCLUSIONS These data indicate that susceptibility to diabetic glomerulopathy in MNS rats is associated with increased GLUT1-dependent glucose transport activity in response to hyperglycaemia and/or TGF-beta, which may amplify ECM overproduction. Conversely, the haemodynamic protection from glomerulosclerosis in MHS rats is associated with lack of upregulation of TGF-beta/GLUT1 axis, thus supporting the concept that this axis may represent the link between haemodynamic and metabolic mechanisms of injury.
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Affiliation(s)
- Carlo Ricci
- Department of Clinical Sciences, La Sapienza University, Rome, Italy
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18
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Hills CE, Bland R, Bennett J, Ronco PM, Squires PE. High Glucose Up-Regulates ENaC and SGK1 Expression in HCD-Cells. Cell Physiol Biochem 2006; 18:337-46. [PMID: 17170520 DOI: 10.1159/000097611] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM Diabetic nephropathy is associated with progressive renal damage, leading to impaired function and end-stage renal failure. Secondary hypertension stems from a deranged ability of cells within the kidney to resolve and appropriately regulate sodium resorption in response to hyperglycaemia. However, the mechanisms by which glucose alters sodium re-uptake have not been fully characterised. METHODS Here we present RT-PCR, western blot and immunocytochemistry data confirming mRNA and protein expression of the serum and glucocorticoid inducible kinase (SGK1) and the alpha conducting subunit of the epithelial sodium channel (ENaC) in a model in vitro system of the human cortical collecting duct (HCD). We examined changes in expression of these elements in response to glucose challenge, designed to mimic hyperglycaemia associated with type 2 diabetes mellitus. Changes in Na+ concentration were assessed using single-cell microfluorimetry. RESULTS Incubation with glucose, the Ca2+-ionophore ionomycin and the cytokine TGF-beta1 were all found to evoke significant and time-dependent increases in both SGK1 and alphaENaC protein expression. These molecular changes were correlated to an increase in Na+-uptake at the single-cell level. CONCLUSION Together these data offer a potential explanation for glucose-evoked Na+-resorption and a potential contributory role of SGK1 and ENaCs in development of secondary hypertension, commonly linked to diabetic nephropathy.
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Affiliation(s)
- Claire E Hills
- Molecular Physiology, Biomedical Research Institute, Department of Biological Sciences, University of Warwick, Coventry, UK
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19
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Zhu Y, Casado M, Vaulont S, Sharma K. Role of upstream stimulatory factors in regulation of renal transforming growth factor-beta1. Diabetes 2005; 54:1976-84. [PMID: 15983197 DOI: 10.2337/diabetes.54.7.1976] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We previously identified an E-box to be implicated in high-glucose-induced transforming growth factor-beta1 (TGF-beta1) gene stimulation in murine mesangial cells. In the present study, we evaluated the role of upstream stimulatory factors (USFs) in mediating glucose-induced stimulation of TGF-beta1. Mesangial cells cultured in glucose concentrations exceeding 2.7 mmol/l D-glucose exhibited increased levels of USF1 and USF2 protein by Western analysis and electrophoretic mobility shift assay (EMSA). An E-box element from the murine TGF-beta1 promoter revealed USF1 and USF2 binding by EMSA. Chromatin immunoprecipitation assay revealed in vivo binding of USF1 to a glucose-responsive region of the TGF-beta1 promoter. Transient cotransfection studies of 293 cells with USF1 led to a twofold increase in TGF-beta1 promoter activity and a 46% increase in secreted TGF-beta1 protein levels. Wild-type and USF2 knockout mice exhibited a 2.5-fold stimulation of renal TGF-beta1 expression upon fasting and refeeding with a carbohydrate-rich diet, whereas USF1 knockout mice exhibited only a minimal increase of renal TGF-beta1 upon refeeding. USF1 mRNA levels were increased in mouse kidneys with carbohydrate refeeding, and USF1 protein was increased in diabetic rat kidneys compared with controls. We conclude that USF1 is stimulated by modest increases in glucose concentration in murine mesangial cells, bind to the murine TGF-beta1 promoter, contribute to carbohydrate-induced renal TGF-beta1 expression, and may play a role in diabetes-related gene regulation in the kidney.
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Affiliation(s)
- Yanqing Zhu
- Department of Medicine, Division of Nephrology, Dorrance Hamilton Research Laboratories, Thomas Jefferson University, Philadelphia, PA 19107, USA
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20
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Jones KS, Akel S, Petrow-Sadowski C, Huang Y, Bertolette DC, Ruscetti FW. Induction of Human T Cell Leukemia Virus Type I Receptors on Quiescent Naive T Lymphocytes by TGF-β. THE JOURNAL OF IMMUNOLOGY 2005; 174:4262-70. [PMID: 15778389 DOI: 10.4049/jimmunol.174.7.4262] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Hodgkinson AD, Page T, Millward BA, Demaine AG. A novel polymorphism in the 5' flanking region of the glucose transporter (GLUT1) gene is strongly associated with diabetic nephropathy in patients with Type 1 diabetes mellitus. J Diabetes Complications 2005; 19:65-9. [PMID: 15745834 DOI: 10.1016/j.jdiacomp.2004.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Revised: 06/16/2004] [Accepted: 07/16/2004] [Indexed: 12/13/2022]
Abstract
Glucose transporter 1 (GLUT1) activity has been implicated in renal hypertrophy and extracellular matrix formation in mesangial cells. Recent studies have suggested that polymorphisms in the GLUT1 gene are associated with susceptibility to diabetic nephropathy (DN) in patients with diabetes mellitus. In this study, a novel polymorphism (A-2841T) in the 5' flanking region of GLUT1 was examined in 288 patients with Type 1 diabetes mellitus (T1DM) and 101 normal controls. The polymorphisms were amplified and the fragment digested with the enzyme HpyCH4V. There was a highly significant increase in the frequency of the TT-2841 genotype in patients with nephropathy (n=131) compared with those with either no microvascular complications after a 20-year duration of diabetes (uncomplicated; n=72; 54.5% vs. 2.7%, chi=79.4, P<.000001). There was no difference between the uncomplicated group and those who only had retinopathy (n=50; 2.7% vs. 4.0%, respectively). The frequency in recently diagnosed patients was 17.1% and only 2.0% in normal controls. In contrast, the AA genotype was found in 13.6% of the nephropaths, 76.3% of uncomplicated, 48.0% of retinopaths, and 65% of normal controls. These results confirm previous reports of an association between the GLUT1 gene and susceptibility to DN but not retinopathy. The localisation of this polymorphism suggests that it may be involved in the expression of the gene.
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Affiliation(s)
- A D Hodgkinson
- Molecular Medicine Research Group, Institute of Biomedical Sciences, Peninsula Medical School, Room N32, ITTC Building, Plymouth Campus, Tamar Science Park, Plymouth PL6 8BX, United Kingdom
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22
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Zintzaras E, Stefanidis I. Association between the GLUT1 gene polymorphism and the risk of diabetic nephropathy: a meta-analysis. J Hum Genet 2005; 50:84-91. [PMID: 15682272 DOI: 10.1007/s10038-004-0224-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Accepted: 11/29/2004] [Indexed: 12/13/2022]
Abstract
The association between diabetic nephropathy (DN) and the XbalphaI polymorphism in the GLUT1 gene has been investigated in several case-control studies. These studies rendered contradictory results: the allele XbalphaI(-) was shown either to be a risk factor or neutral, or even protective for the development of the disease. To shed some light on these inconclusive findings, a meta-analysis of all available studies relating the XbalphaI polymorphism to the risk of developing DN was conducted. Five out of six identified studies included Caucasian populations, and only one involved samples from an Asian population. Overall, the meta-analysis suggested large heterogeneity between studies (P<0.01, I2=68%) and lack of association between allele XbalphaI(-) and the risk of developing DN relative to allele XbalphaI(+): random effects odds ratio (OR)=1.26 [95% CI (0.93, 1.69)]. Excluding one study with the controls not in Hardy-Weinberg equilibrium, the sensitivity analysis revealed that heterogeneity (P=0.28, I2=21%) could be explained, and then, there is an overall association: fixed effects OR=1.34 [95% CI (1.13, 1.60)]. Then, significant ORs were also found on analysis of subgroups: for the Caucasian population, fixed effects OR=1.29 [95% CI (1.08, 1.56)] and for the type 2 diabetic patients fixed effects OR=1.69 [95% CI (1.09, 2.63)]. In type 1 diabetes, there is a moderate heterogeneity (P=0.19, I2=41%) with fixed effects OR=1.29 [95% CI (1.06, 1.56)] and random effects OR=1.32 [95% CI (1.01, 1.71)]. There is a source of bias in the selected studies: large studies failed to show association while small studies claimed an association. Although there is evidence of association between GLUT1 and DN, the above findings reinforce the need for further and more rigorous association studies.
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Affiliation(s)
- Elias Zintzaras
- Department of Biomathematics, University of Thessaly School of Medicine, Papakyriazy 22, Larissa, 41222, Greece.
| | - Ioannis Stefanidis
- Division of Nephrology, University Hospital of Larissa, University of Thessaly School of Medicine, Papakyriazy 22, Larissa, 41222, Greece
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23
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Abstract
Diabetic nephropathy (DN) is a common complication of diabetes types 1 and 2. One of the hallmarks of DN is the development of mesangial expansion, which occurs through accumulation of extracellular matrix (ECM) components. Altered local gene expression of humoral factors (eg, transforming growth factor-b, connective tissue growth factor, and platelet-derived growth factor) can lead to increased production of ECM components (eg, fibronectin and collagen IV) or decreased degradation through matrix metalloproteinases (eg, MMP-1, MMP-2). In recent years, new techniques for examination of gene expression have been developed. Because of their large scale and high-throughput character, it is now possible to examine differential gene expression in a large number of samples. This paper provides an overview of techniques used and results obtained in studies of DN. Newly developed concepts of how altered gene expression may affect histomorphologic features or clinical symptoms are also discussed.
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Affiliation(s)
- Daniela Hohenadel
- Fifth Medical Department, University Clinic Mannheim, Theodor-Kutzer-Ufer 1-3, Mannheim 68167, Germany.
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24
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Joyner NT, Smoak IW. In vivo hyperglycemia and its effect on Glut-1 expression in the embryonic heart. ACTA ACUST UNITED AC 2004; 70:438-48. [PMID: 15259033 DOI: 10.1002/bdra.20046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Maternal diabetes exposes embryos to periods of hyperglycemia. Glucose is important for normal cardiogenesis, and Glut-1 is the predominant glucose transporter in the embryo. METHODS Pregnant mice were exposed to 6 or 12 hr hyperglycemia during organogenesis using intraperitoneal (IP) injections of D-glucose on gestational day (GD) 9.5 (plug = GD 0.5). Embryos were examined for morphology and total cardiac protein, and embryonic hearts were evaluated for Glut-1 protein and mRNA expression immediately after treatment (GD 9.75, GD 10.0), as well as on GD 10.5 and GD 12.5. RESULTS IP glucose injections were effective in producing sustained maternal hyperglycemia. Maternal hyperglycemia for 6 or 12 hr on GD 9.5, followed by normoglycemia, produced a decrease in overall size and total cardiac protein in embryos evaluated on GD 10.5 but no difference on GD 12.5. Cardiac Glut-1 expression was immediately upregulated in embryos exposed to 6 or 12 hr maternal hyperglycemia. On GD 10.5, cardiac Glut-1 expression was not different in embryos exposed to maternal hyperglycemia for 6 hr but was downregulated in embryos exposed for 12 hr. On GD 12.5, cardiac Glut-1 expression in embryos exposed to maternal hyperglycemia on GD 9.5 for 6 or 12 hr, followed by normoglycemia, was not different from controls. The temporal pattern was the same for Glut-1 protein and mRNA expression. CONCLUSIONS Hyperglycemia-induced alterations in Glut-1 expression likely interfere with balance of glucose available to the embryonic heart that may affect cardiac morphogenesis.
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Affiliation(s)
- Nia T Joyner
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
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25
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Chen S, Jim B, Ziyadeh FN. Diabetic nephropathy and transforming growth factor-beta: transforming our view of glomerulosclerosis and fibrosis build-up. Semin Nephrol 2004; 23:532-43. [PMID: 14631561 DOI: 10.1053/s0270-9295(03)00132-3] [Citation(s) in RCA: 194] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The manifestations of diabetic nephropathy may be a consequence of the actions of certain cytokines and growth factors. Prominent among these is transforming growth factor beta (TGF-beta) because it promotes renal cell hypertrophy and stimulates extracellular matrix accumulation, the 2 hallmarks of diabetic renal disease. In tissue culture studies, cellular hypertrophy and matrix production are stimulated by high glucose concentrations in the culture media. High glucose, in turn, appears to act through the TGF-beta system because high glucose increases TGF-beta expression, and the hypertrophic and matrix-stimulatory effects of high glucose are prevented by anti-TGF-beta therapy. In experimental diabetes mellitus, several reports describe overexpression of TGF-beta or TGF-beta type II receptor in the glomerular and tubulointerstitial compartments. As might be expected, the intrarenal TGF-beta system is triggered, evidenced by activity of the downstream Smad signaling pathway. Treatment of diabetic animals with a neutralizing anti-TGF-beta antibody prevents the development of mesangial matrix expansion and the progressive decline in renal function. This antibody therapy also reverses the established lesions of diabetic glomerulopathy. Finally, the renal TGF-beta system is significantly up-regulated in human diabetic nephropathy. Although the kidney of a nondiabetic subject extracts TGF-beta1 from the blood, the kidney of a diabetic patient actually elaborates TGF-beta1 protein into the circulation. Along the same line, an increased level of TGF-beta in the urine is associated with worse clinical outcomes. In concert with TGF-beta, other metabolic mediators such as connective tissue growth factor and reactive oxygen species promote the accumulation of excess matrix. This fibrotic build-up also occurs in the tubulointerstitium, probably as the result of heightened TGF-beta activity that stimulates tubular epithelial and interstitial fibroblast cells to overproduce matrix. The data presented here strongly support the consensus that the TGF-beta system mediates the renal hypertrophy, glomerulosclerosis, and tubulointerstitial fibrosis of diabetic kidney disease.
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Affiliation(s)
- Sheldon Chen
- Department of Medicine, University of Philadelphia, PA 19104, USA
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26
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Lang KS, Mueller MM, Tanneur V, Wallisch S, Fedorenko O, Palmada M, Lang F, Bröer S, Heilig CW, Schleicher E, Weigert C. Regulation of cytosolic pH and lactic acid release in mesangial cells overexpressing GLUT1. Kidney Int 2003; 64:1338-47. [PMID: 12969152 DOI: 10.1046/j.1523-1755.2003.00213.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Anaerobic glycolysis leads to the formation of lactate and H+ and thus imposes a significant challenge on cytosolic acid/base regulation. Cytosolic acidification, on the other hand, is known to inhibit flux through glycolysis and lactate formation. To explore the interplay of cytosolic pH and glycolysis, rat mesangial cells transfected with the glucose transporter GLUT1 (GLUT1 cells) were compared with those transfected with beta-galactosidase (LacZ cells). METHODS In the presence of extracellular glucose, the glycolytic rate was one order of magnitude higher in GLUT1 cells than in LacZ cells. Cytosolic pH (pHi) was significantly higher in GLUT1 than LacZ cells, an effect abolished in the presence of Na+/H+ exchange inhibitor ethylisopropylamiloride (1 micromol/L). RESULTS Addition of 40 mmol/L lactate led to marked cytosolic acidification, which was in both cell types blunted by O-methyl-glucose (20 mmol/L) and completely abolished by 100 micromol/L phloretin and 1 mmol/L p-chloromercuribenzene-sulphonic acid (p-CMBS) and in LacZ cells only by glucose (20 mmol/L). The functional characterization points to the involvement of a lactic acid transporter from the monocarboxylate transporter (MCT) family, particularly MCT1. Reverse transcription-polymerase chain reaction (RT-PCR) indeed disclosed the expression of MCT1 and MCT2 in both GLUT1 and LacZ cells. CONCLUSION Overexpression of GLUT1 leads to cytosolic alkalinization of mesangial cells depending on functional Na+/H+ exchanger but not on Na+ independent H+ transport.
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Affiliation(s)
- Karl S Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany
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27
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Affiliation(s)
- Fuad N Ziyadeh
- Renal-Electrolyte and Hypertension Division, 700 Clinical Research Building, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA 19104-6144, USA.
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Weigert C, Brodbeck K, Brosius FC, Huber M, Lehmann R, Friess U, Facchin S, Aulwurm S, Häring HU, Schleicher ED, Heilig CW. Evidence for a novel TGF-beta1-independent mechanism of fibronectin production in mesangial cells overexpressing glucose transporters. Diabetes 2003; 52:527-35. [PMID: 12540631 DOI: 10.2337/diabetes.52.2.527] [Citation(s) in RCA: 59] [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: 11/13/2022]
Abstract
Recent experimental work indicates that the hyperglycemia-induced increase in mesangial matrix production, which is a hallmark in the development of diabetic nephropathy, is mediated by increased expression of GLUT1. Mesangial cells stably transfected with human GLUT1 mimic the effect of hyperglycemia on the production of the extracellular matrix proteins, particularly fibronectin, when cultured under normoglycemic conditions. Our investigation of the molecular mechanism of this effect has revealed that the enhanced fibronectin production was not mediated by the prosclerotic cytokine transforming growth factor (TGF)-beta1. We found markedly increased nuclear content in Jun proteins, leading to enhanced DNA-binding activity of activating protein 1 (AP-1). AP-1 inhibition reduced fibronectin production in a dosage-dependent manner. Moreover, inhibition of classic protein kinase C (PKC) isoforms prevented both the activation of AP-1 and the enhanced fibronectin production. In contrast to mesangial cells exposed to high glucose, no activation of the hexosamine biosynthetic, p38, or extracellular signal-related kinase 1 and 2 mitogen-activated protein kinase pathways nor any increase in TGF-beta1 synthesis could be detected, which could be explained by the absence of oxidative stress in cells transfected with the human GLUT1 gene. Our data indicate that increased glucose uptake and metabolism induce PKC-dependent AP-1 activation that is sufficient for enhanced fibronectin production, but not for increased TGF-beta1 expression.
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Affiliation(s)
- Cora Weigert
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Pathobio-Chemistry, University of Tübingen, Germany
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Abstract
Puberty accelerates microvascular complications of diabetes mellitus, including nephropathy. Animal studies confirm a different renal hypertrophic response to diabetes before and after puberty, probably due to differences in the production of transforming growth factor-beta (TGF-beta). Many of the complex physiological changes during puberty could affect potentially pathogenic mechanisms of diabetic kidney disease. Increased blood pressure, activation of the growth hormone-insulin-like growth factor I axis, and production of sex steroids could all play a role in pubertal susceptibility to diabetic renal hypertrophy and nephropathy. These factors may influence the effects of hyperglycemia and several systems that ultimately control TGF-beta production, including the renin-angiotensin system, cellular redox systems, the polyol pathway, and protein kinase C. These phenomena may also explain gender differences in kidney function and incidence of end-stage renal disease. Normal changes during puberty, when coupled with diabetes and superimposed on a genetically susceptible milieu, are capable of accelerating diabetic hypertrophy and microvascular lesions. A better understanding of these processes may lead to new treatments to prevent renal failure in diabetes mellitus.
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Affiliation(s)
- Pascale H Lane
- Department of Pediatrics, University of Nebraska Medical Center, Omaha 68198-2169, USA.
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30
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Ng DPK, Canani L, Araki SI, Smiles A, Moczulski D, Warram JH, Krolewski AS. Minor effect of GLUT1 polymorphisms on susceptibility to diabetic nephropathy in type 1 diabetes. Diabetes 2002; 51:2264-9. [PMID: 12086959 DOI: 10.2337/diabetes.51.7.2264] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Elevation of intracellular glucose in mesangial cells as mediated by GLUT1 may be important in initiating cellular mechanisms that cause diabetic nephropathy. To determine whether DNA sequence differences in GLUT1 confer susceptibility to this complication, single-nucleotide polymorphisms (SNPs) in this gene were examined using a large case-control study. SNPs examined included the known XbaI (intron 2) and HaeIII SNPs (exon 2). Four novel SNPs located in three putative enhancers were also investigated. Homozygosity for the XbaI(-) allele was associated with diabetic nephropathy (odds ratio 1.83 [95% CI 1.01-3.33]). Furthermore, homozygosity for the A allele for a novel SNP (enhancer-2 SNP 1) located in a putative insulin-responsive enhancer-2 was associated with diabetic nephropathy (2.38 [1.16-4.90]). Patients who were homozygous for risk alleles at both XbaI SNP and enhancer-2 SNP 1 [i.e., homozygosity for XbaI(-)/A haplotype] also had an increased risk of diabetic nephropathy (2.40 [1.13-5.07]). Because enhancer-2 SNP 1 may directly control GLUT1 expression, the strong linkage disequilibrium between the two SNPs likely accounts for XbaI SNP being associated with diabetic nephropathy. In conclusion, our study confirms that SNPs at the GLUT1 locus are associated with susceptibility to diabetic nephropathy in type 1 diabetes. Although these SNPs confer a considerable personal risk for diabetic nephropathy, they account for a limited proportion of cases among type 1 diabetic patients.
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Affiliation(s)
- Daniel P K Ng
- Section on Genetics and Epidemiology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215, USA
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Weigert C, Brodbeck K, Häring HU, Gambaro G, Schleicher ED. Low-molecular-weight heparin prevents high glucose- and phorbol ester-induced TGF-beta 1 gene activation. Kidney Int 2001; 60:935-43. [PMID: 11532088 DOI: 10.1046/j.1523-1755.2001.060003935.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Hyperglycemia-induced overexpression of prosclerotic transforming growth factor-beta 1 (TGF-beta 1) has been implicated in the pathogenesis of diabetic nephropathy. Since previous in vivo studies demonstrated a renoprotective effect of low-molecular-weight (LMW) heparin in experimental animals, and recent in vitro data showed an interaction of this drug with the overactivated TGF-beta 1 cascade in high glucose- and phorbol ester-stimulated mesangial cells, we studied the molecular mechanism of these effects on TGF-beta 1 gene expression. METHODS Mesangial cells were stimulated with 30 mmol/L glucose or with 0.5 micromol/L phorbol ester [phorbol myristate acetate (PMA)] in the absence or presence of LMW heparin. TGF-beta 1 promoter activity was determined in promoter-reporter luciferase assays. The effect of LMW heparin on the binding of nuclear proteins to a regulatory activator protein-1 (AP-1) site, which mediates the high glucose and PMA responsiveness of the TGF-beta 1 promoter, was studied by electrophoretic mobility shift assays. RESULTS The presence of LMW heparin completely prevented TGF-beta 1 gene activation in both high glucose- and PMA-stimulated cells. Preincubation of the cells with LMW heparin and subsequent stimulation of the cells with both stimuli yielded the same result. Furthermore, treatment with LMW heparin prevented the enhanced binding of nuclear proteins to the regulatory AP-1 site, while binding to a Sp1 site was unaffected. Basal promoter activity and basal AP-1 binding also was reduced by LMW heparin. The LMW heparin effect on basal promoter activity was abolished by mutation of the regulatory AP-1 box B and by deletion of this AP-1 binding site. CONCLUSIONS LMW heparin prevents high glucose- and PMA-mediated TGF-beta 1 expression by inhibiting the activation of the TGF-beta 1 promoter and by preventing the enhanced binding of nuclear proteins to the regulatory AP-1 site.
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Affiliation(s)
- C Weigert
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Pathobio-chemistry, University of Tübingen, Tübingen, Germany
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Han DC, Isono M, Chen S, Casaretto A, Hong SW, Wolf G, Ziyadeh FN. Leptin stimulates type I collagen production in db/db mesangial cells: glucose uptake and TGF-beta type II receptor expression. Kidney Int 2001; 59:1315-23. [PMID: 11260392 DOI: 10.1046/j.1523-1755.2001.0590041315.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Serum leptin levels correlate with fat cell mass and are elevated in patients with massive obesity and type 2 diabetes mellitus, which are strong risk factors for the development of glomerulosclerosis. We have previously shown in cultured glomerular endothelial cells that leptin stimulates cellular proliferation and expression of the prosclerotic cytokine transforming growth factor-beta1 (TGF-beta1). Although the effect of leptin on the hypothalamus to regulate energy homeostasis is well known, the effect of leptin on the kidney, and specifically on the glomerular mesangial cell, is unclear. METHODS The obese, diabetic db/db mouse, which lacks the functional full-length Ob-Rb leptin receptor, is a suitable model to assess the effects of hyperleptinemia on peripheral tissues that express other receptor isoforms. The effects of leptin on glucose uptake, the TGF-beta system, and type I collagen production were evaluated in db/db mouse mesangial cells in culture. A phosphatidylinositol-3 kinase (PI-3K) inhibitor was used to assess the role of PI-3K in mediating the effects of leptin. RESULTS A short form of the leptin receptor (Ob-Ra), but not Ob-Rb, was present by reverse transcription-polymerase chain reaction in the kidney and mesangial cells of both nondiabetic db/m and diabetic db/db mice. In db/db mesangial cells, leptin increased 2-deoxy-D-glucose (2DOG) uptake dose dependently and stimulated gene expression of TGF-beta type II receptor (TbetaRII) and alpha1(I) collagen, but not TGF-beta1. Protein production of type I collagen (enzyme-linked immunosorbent assay) was also increased by leptin. Both leptin-stimulated 2DOG uptake and type I collagen production were suppressed by a PI-3K inhibitor, LY294002. Mesangial cells pretreated with leptin exhibited increased responsiveness to exogenous TGF-beta1, as evidenced by a greater production of type I collagen protein in leptin-pretreated cells exposed to low-dose TGF-beta1 (0.5 ng/mL). The addition of both TGF-beta1 (2 ng/mL) and leptin (100 ng/mL) increased type I collagen production more than addition of either TGF-beta1 or leptin alone. CONCLUSIONS Leptin increases glucose uptake and type I collagen in db/db mesangial cells through a PI-3K-dependent pathway. We postulate that increased leptin levels may transmit a signal through the short-form leptin receptor to up-regulate TbetaRII and activate the intraglomerular TGF-beta system, which may contribute to the glomerulosclerosis of obesity or type 2 diabetes.
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Affiliation(s)
- D C Han
- Renal-Electrolyte and Hypertension Division and Penn Center for Molecular Studies of Kidney Diseases, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6144, USA
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Grzeszczak W, Moczulski DK, Zychma M, Zukowska-Szczechowska E, Trautsolt W, Szydlowska I. Role of GLUT1 gene in susceptibility to diabetic nephropathy in type 2 diabetes. Kidney Int 2001; 59:631-6. [PMID: 11168944 DOI: 10.1046/j.1523-1755.2001.059002631.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The XbaI polymorphism in the glucose transporter GLUT1 gene has been implicated in the development of diabetic nephropathy in Chinese type 2 diabetes patients. METHODS To examine whether the XbaI polymorphism is involved in the development of diabetic nephropathy in Caucasian type 2 diabetes patients, a large case control study was performed. The study group of 444 patients with type 2 diabetes consisted of three subgroups: 162 patients with normoalbuminuria (only patients with duration of type 2 diabetes of at least 10 years after diagnosis); 150 with microalbuminuria; and 132 subjects with persistent proteinuria or chronic renal failure (CRF). The polymerase chain reaction (PCR)-based genotyping of the XbaI polymorphism was performed in each subject. RESULTS The genotype distribution in the subgroups showed an increased frequency of the (+/+) genotype in patients with microalbuminuria (41%; OR 1.40, 95% CI, 0.89 to 2.24) and proteinuria/CRF (47%; OR 1.82, 95% CI, 1.13 to 2.93, P = 0.013) when compared with normoalbuminuria (33%). No difference in the genotype distribution was observed between type 2 diabetes patients and healthy controls. CONCLUSIONS The results of this study in Caucasian patients with type 2 diabetes indicate that the XbaI(-) allele in the GLUT1 gene protects against the development of diabetic nephropathy. Our results are in contrast to the case control study in Chinese patients with type 2 diabetes in which the presence of the XbaI(-) allele appeared to have a strong association with the development of diabetic nephropathy.
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Affiliation(s)
- W Grzeszczak
- Department of Internal Medicine and Diabetes, Silesian School of Medicine, Zabrze, Poland.
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Gambaro G, Ceol M, Del Prete D, D'Angelo A. GLUT-1 and TGF-beta: the link between hyperglycaemia and diabetic nephropathy. Nephrol Dial Transplant 2000; 15:1476-7. [PMID: 10978417 DOI: 10.1093/ndt/15.9.1476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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