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Karachalias N, Babaei-Jadidi R, Rabbani N, Thornalley PJ. Increased protein damage in renal glomeruli, retina, nerve, plasma and urine and its prevention by thiamine and benfotiamine therapy in a rat model of diabetes. Diabetologia 2010; 53:1506-16. [PMID: 20369223 DOI: 10.1007/s00125-010-1722-z] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 02/03/2010] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS The aim of this study was to quantify protein damage by glycation, oxidation and nitration in a rat model of diabetes at the sites of development of microvascular complications, including the effects of thiamine and benfotiamine therapy. METHODS Diabetes was induced in male Sprague-Dawley rats by 55 mg/kg streptozotocin and moderated by insulin (2 U twice daily). Diabetic and control rats were given thiamine or benfotiamine (7 or 70 mg kg(-1) day(-1)) over 24 weeks. Plasma, urine and tissues were collected and analysed for protein damage by stable isotopic dilution analysis MS. RESULTS There were two- to fourfold increases in fructosyl-lysine and AGE content of glomerular, retinal, sciatic nerve and plasma protein in diabetes. Increases in AGEs were reversed by thiamine and benfotiamine therapy but increases in fructosyl-lysine were not. Methionine sulfoxide content of plasma protein and 3-nitrotyrosine content of sciatic nerve protein were increased in diabetes. Plasma glycation free adducts were increased up to twofold in diabetes; the increases were reversed by thiamine. Urinary excretion of glycation, oxidation and nitration free adducts was increased by seven- to 27-fold in diabetes. These increases were reversed by thiamine and benfotiamine therapy. CONCLUSIONS/INTERPRETATION AGEs, particularly arginine-derived hydroimidazolones, accumulate at sites of microvascular complication development and have markedly increased urinary excretion rates in experimental diabetes. Thiamine and benfotiamine supplementation prevented tissue accumulation and increased urinary excretion of protein glycation, oxidation and nitration adducts. Similar effects may contribute to the reversal of early-stage clinical diabetic nephropathy by thiamine.
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Affiliation(s)
- N Karachalias
- Department of Biological Sciences, University of Essex, Central Campus, Wivenhoe Park, Colchester, Essex, UK
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Simpson NR, Souza F, Witkowski P, Maffei A, Raffo A, Herron A, Kilbourn M, Jurewicz A, Herold K, Liu E, Hardy MA, Van Heertum R, Harris PE. Visualizing pancreatic beta-cell mass with [11C]DTBZ. Nucl Med Biol 2007; 33:855-64. [PMID: 17045165 PMCID: PMC3743255 DOI: 10.1016/j.nucmedbio.2006.07.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 06/29/2006] [Accepted: 07/03/2006] [Indexed: 01/09/2023]
Abstract
Beta-cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, beta-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation. Built on previous gene expression studies, we tested the hypothesis that the targeting of vesicular monoamine transporter 2 (VMAT2), which is expressed by beta cells, with [11C]dihydrotetrabenazine ([11C]DTBZ), a radioligand specific for VMAT2, and the use of positron emission tomography (PET) can provide a measure of BCM. In this report, we demonstrate decreased radioligand uptake within the pancreas of Lewis rats with streptozotocin-induced diabetes relative to their euglycemic historical controls. These studies suggest that quantitation of VMAT2 expression in beta cells with the use of [11C]DTBZ and PET represents a method for noninvasive longitudinal estimates of changes in BCM that may be useful in the study and treatment of diabetes.
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Affiliation(s)
- Norman Ray Simpson
- Department of Radiology, Columbia University Medical School, New York, NY 10032, USA
| | - Fabiola Souza
- Department of Medicine, Columbia University Medical School, New York, NY 10032, USA
| | - Piotr Witkowski
- Department of Surgery, Columbia University Medical School, New York, NY 10032, USA
| | - Antonella Maffei
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso”, CNR, Naples 80131, Italy
| | - Anthony Raffo
- Department of Medicine, Columbia University Medical School, New York, NY 10032, USA
| | - Alan Herron
- Center for Comparative Medicine and The Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael Kilbourn
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109-0638, USA
| | - Agata Jurewicz
- Department of Radiology, Columbia University Medical School, New York, NY 10032, USA
| | - Kevan Herold
- Department of Medicine, Columbia University Medical School, New York, NY 10032, USA
| | - Eric Liu
- Diabetes Branch, NIDDK, National Institutes of Health, Bethesda, MD 20854, USA
| | - Mark Adam Hardy
- Department of Surgery, Columbia University Medical School, New York, NY 10032, USA
| | - Ronald Van Heertum
- Department of Radiology, Columbia University Medical School, New York, NY 10032, USA
| | - Paul Emerson Harris
- Department of Medicine, Columbia University Medical School, New York, NY 10032, USA
- Corresponding author. BB 20-06, Department of Medicine, College of Physicians and Surgeons, New York, NY 10032, USA. Tel.: +1 212 305 7363; fax: +1 212 305 7348. (P.E. Harris)
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Hu M, Wu Y, Wu H. Influence of streptozotocin-induced diabetes in rats on the lithium content of tissue and the effect of dietary lithium supplements on this diabetic condition. Metabolism 1999; 48:558-63. [PMID: 10337853 DOI: 10.1016/s0026-0495(99)90050-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To study the effects of lithium supplementation on the diabetic condition, we measured the lithium concentration in the liver, kidney, and muscle from streptozotocin (STZ)-induced diabetic male Sprague-Dawley (SD) rats that were either treated or untreated with peroral lithium carbonate (0.3 mg/mL). The data showed that the lithium content of the liver and muscle was significantly lower in STZ rats than in normal control rats (0.22 +/- 0.05 v 1.30 +/- 0.15, P < .01, and 0.79 +/- 0.30 v 2.48 +/- 2.00 microg/g, respectively). After 4 weeks of lithium carbonate supplementation, we found that (1) the lithium content of the liver and muscle returned to the normal range, (2) the extent of STZ-mediated destruction of beta cells in the pancreas decreased, (3) fasting blood glucose (FBG) and 2-hour postprandial blood glucose (PBG) decreased (P < .05), (4) among the indicators of oxidative stress and antioxidant defenses, blood lipid peroxidate (LPO) decreased and erythrocyte superoxide dismutase (RBC-SOD) and glutathione (GSH) returned to normal, and (5) hepatic LPO decreased and glutathione peroxidase (GSH-Px) increased. These results suggest that the restoration of lithium to control levels in the liver and muscle of diabetic animals is associated not only with decreased blood glucose but also with reduced oxidative stress, and consequently with the protection of insulin-secreting pancreatic islet cells.
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Affiliation(s)
- M Hu
- Institute of Metabolism and Endocrinology, The Second Affiliated Hospital, Hunan Medical University, Changsha, China
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Cam MC, Li WM, McNeill JH. Partial preservation of pancreatic beta-cells by vanadium: evidence for long-term amelioration of diabetes. Metabolism 1997; 46:769-78. [PMID: 9225830 DOI: 10.1016/s0026-0495(97)90121-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Streptozotocin (STZ)-diabetic rats treated with vanadium can remain euglycemic for up to 20 weeks following withdrawal from vanadium treatment. In this study, we examined the effects of short-term vanadium treatment in preventing or reversing the STZ-induced diabetic state. Male Wistar rats were untreated (D) or treated (DT) with vanadyl sulfate for 1 week before administering STZ. Treatment was subsequently maintained for 3 days (DT3) or 14 days (DT14) post-STZ, after which vanadium was withdrawn. At 4 to 5 weeks post-STZ and following long-term withdrawal from vanadium, DT14 rats demonstrated levels of food and fluid intake and glucose tolerance that were not significantly different from those of age-matched untreated nondiabetic rats, and had significantly reduced glycemic levels in the fed state compared with D and DT3 groups. The proportion of animals that were euglycemic (fed plasma glucose < 9.0 mmol/L) was significant in DT14 (five of 10) relative to D (one of 10) and DT3 (one of 10) (P = .01). All euglycemic animals had an improved pancreatic insulin content that, albeit low (12% of control), was strongly linked to euglycemia in the fed state (r = -.91, P < .0001). Moreover, the highly significant correlation persisted with the analysis of untreated STZ-rats alone (r = -.95, P < .0001). Similarly, improvements in glucose tolerance and insulin secretory function in euglycemic rats were strongly correlated with small changes in residual insulin content. Hence, as vanadium pretreatment did not prevent STZ-induced beta-cytotoxicity, the vanadium-induced amelioration of the diabetic state appears to be secondary to the preservation of a functional portion of pancreatic beta cells that initially survived STZ toxicity. The partial preservation of pancreatic beta cells, albeit small in proportion to the total insulin store, was both critical and sufficient for a long-term reversal of the diabetic state. These results suggest that apparently modest effects in preserving residual pancreatic insulin content can have profound consequences on glucose homeostasis and may bear important implications for interventions that have "limited" protective effects on beta cells.
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Affiliation(s)
- M C Cam
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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Guldenaar SE, Swabb DF. Estimation of oxytocin mRNA in the human paraventricular nucleus in AIDS by means of quantitative in situ hybridization. Brain Res 1995; 700:107-14. [PMID: 8624699 DOI: 10.1016/0006-8993(95)00939-n] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recently, a 40% reduction in the total of oxytocin immunoreactive neurons of the paraventricular nucleus of the hypothalamus in AIDS patients was reported. In the present study, we determined whether this decrease is associated with a diminished amount of oxytocin mRNA. We used in situ hybridization combined with densitometric image analysis for the quantitative assessment of oxytocin gene expression in the paraventricular nucleus of a group of AIDS patients (n=10) and a carefully matched control group (n=8). We found no significant difference (P=0.08) in the amount of oxytocin mRNA per total paraventricular nucleus between the two groups. In addition, no significant differences were found in the part of the volume of the paraventricular nucleus that was occupied by hybridized cells (P=0.12) or in the mean signal density (P=0.08). The findings do not support the hypothesis that the extensive decrease in oxytocin immunoreactive neurons of the paraventricular nucleus in AIDS is associated with a decrease in total oxytocin mRNA content in this nucleus. The data are compatible with the suggestion that in AIDS the biosynthesis of oxytocin is changed in an unknown way at the (post)transcriptional level.
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Affiliation(s)
- S E Guldenaar
- Graduate School of Neurosciences Amsterdam, Netherlands Institute for Brain Research, Amsterdam, The Netherlands
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Lernmark A, Klöppel G, Stenger D, Vathanaprida C, Fält K, Landin-Olsson M, Baskin DG, Palmer JP, Gown AM, Petersen JS. Heterogeneity of islet pathology in two infants with recent onset diabetes mellitus. Virchows Arch 1995; 425:631-40. [PMID: 7697219 DOI: 10.1007/bf00199353] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The mechanisms by which the beta cells of pancreatic islets are destroyed in insulin-dependent diabetes mellitus (IDDM) are poorly understood. In this report the pancreatic histo- and immunopathology of two children, both HLA-DR 3/4, DQ 2/8 positive and who both died from cerebral oedema within a day of clinical diagnosis of IDDM, were investigated. Patient 1, a 14-month-old girl, had a 4-week history of polydipsia and polyuria. Patient 2, a 3-year-old boy, had 2 days of illness. Both patients had a similarly severe loss of insulin cells but differed markedly as to the extent of lymphocytic islet infiltration (insulitis). Apart from insulitis, marked islet macrophage infiltration was demonstrated in both patients with the HAM-56 monoclonal antibody. Neither patient showed aberrant expression of HLA class II antigens on insulin-immunoreactive cells, but allele-specific HLA-DQ8 expression was evident on endothelial cells. Glutamic acid decarboxylase immunoreactivity was detected in both insulin- and glucagon-immunoreactive cells. It is concluded that the heterogeneity of islet pathology, especially insulitis, may reflect different dynamics and extent rather than different pathomechanisms of immune destruction of islets in IDDM.
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Affiliation(s)
- A Lernmark
- Department of Medicine, University of Washington, Seattle 98195
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Curtis SB, Buchan AM. Proinsulin mRNA and peptide are present in beta-cells of diabetic BB rats. Can J Physiol Pharmacol 1995; 73:92-7. [PMID: 7600459 DOI: 10.1139/y95-013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previous studies have demonstrated that islets isolated from newly diabetic BB rat pancreata retain the ability to release insulin in culture, although in vivo the insulin response to stimulation is absent. The purpose of this study was to determine whether the beta-cells in these newly diabetic animals were releasing stored insulin or whether they were still capable of insulin biosynthesis, since secretory defects may reflect abnormalities in insulin synthetic capacity. Insulin gene transcription was examined using in situ hybridization to detect preproinsulin mRNA (ppImRNA) at the level of the single cell since this technique provides a valid semiquantitative index of insulin biosynthesis. In situ hybridization with digoxigenin-labeled rat insulin probes resulted in strong labeling of beta-cells in normal Wistar rat pancreata; other islet and acinar cells were negative. Double labeling of sections with an antibody to insulin confirmed that the labeled cells were beta-cells only. The intensity of the staining was variable between different islets within the same section, and sometimes within an islet. Nondiabetic and diabetic BB islets were also positive for ppImRNA not only in normal islets but also in islets affected by insulitis. Islets that contained very few beta-cells also contained ppImRNA. A consistent finding was that the intensity of the hybridization signal in many islets from the diabetic BB rats was stronger than in controls, suggesting that there is more ppImRNA in these islets. beta-Cells that were positive for ppImRNA but negative for insulin peptide were also observed; these were in islets that were affected by insulitis.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S B Curtis
- Department of Physiology, University of British Columbia, Vancouver, Canada
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Wang RN, Bouwens L, Klöppel G. Beta-cell proliferation in normal and streptozotocin-treated newborn rats: site, dynamics and capacity. Diabetologia 1994; 37:1088-96. [PMID: 7867880 DOI: 10.1007/bf00418372] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Regeneration of neonatal beta cells after streptozotocin (STZ)-induced destruction may be due to either replication from pre-existing intra-islet beta cells or extra-islet precursor cells. To further investigate this issue, beta-cell growth was analysed in normal and streptozotocin-treated newborn rats (100 micrograms/g body weight) at several time points during the first 20 days of life. Beta cells were identified by insulin immunostaining, non-isotopic in situ hybridization for rat preproinsulin mRNA, and electron microscopy. Their proliferative activity was recorded by bromodeoxyuridine-pulse labelling. Beta-cell size and total volume were determined by computerized morphometry. In normal rats, there was a threefold increase in total beta-cell volume during the first 5 days of life, with no further expansion till day 20. The bromodeoxyuridine labelling index of the intra-islet beta cells was smaller than that of the extra-islet beta cells (2-3% vs 15-20%). Comparison of the cell birth rate, calculated from the beta-cell labelling index, with the observed increase in beta-cell volume suggested that in normal neonatal rats proliferation of the intra-islet beta-cell population could account for only 10% of the observed expansion. Administration of streptozotocin at birth resulted in more than 90% reduction of the total beta-cell volume at day 2 which then increased to 39% of the normal value by day 20. During this period of partial regeneration, which restored normoglycaemia, the labelling index of intra-islet beta cells was higher than in normal rats (9% vs 2%, p < 0.001), whereas no change was seen in the extra-islet beta-cell labelling index.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R N Wang
- Department of Experimental Pathology, Free University of Brussels, Belgium
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