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Bartolomé A, Suda N, Yu J, Zhu C, Son J, Ding H, Califano A, Accili D, Pajvani UB. Notch-mediated Ephrin signaling disrupts islet architecture and β cell function. JCI Insight 2022; 7:157694. [PMID: 35167496 PMCID: PMC8986078 DOI: 10.1172/jci.insight.157694] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/09/2022] [Indexed: 11/23/2022] Open
Abstract
Altered islet architecture is associated with β cell dysfunction and type 2 diabetes (T2D) progression, but molecular effectors of islet spatial organization remain mostly unknown. Although Notch signaling is known to regulate pancreatic development, we observed “reactivated” β cell Notch activity in obese mouse models. To test the repercussions and reversibility of Notch effects, we generated doxycycline-dependent, β cell–specific Notch gain-of-function mice. As predicted, we found that Notch activation in postnatal β cells impaired glucose-stimulated insulin secretion and glucose intolerance, but we observed a surprising remnant glucose intolerance after doxycycline withdrawal and cessation of Notch activity, associated with a marked disruption of normal islet architecture. Transcriptomic screening of Notch-active islets revealed increased Ephrin signaling. Commensurately, exposure to Ephrin ligands increased β cell repulsion and impaired murine and human pseudoislet formation. Consistent with our mouse data, Notch and Ephrin signaling were increased in metabolically inflexible β cells in patients with T2D. These studies suggest that β cell Notch/Ephrin signaling can permanently alter islet architecture during a morphogenetic window in early life.
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Affiliation(s)
- Alberto Bartolomé
- Departamento de Fisiopatología Endocrina y del Sistema Nervioso, IIBm Alberto Sols (CSIC/UAM), Madrid, Spain
| | - Nina Suda
- Department of Medicine, Columbia University, New York, United States of America
| | - Junjie Yu
- Department of Medicine, Columbia University, New York, United States of America
| | - Changyu Zhu
- Department of Medicine, Columbia University, New York, United States of America
| | - Jinsook Son
- Department of Medicine, Columbia University, New York, United States of America
| | - Hongxu Ding
- Systems Biology, Columbia University College of Physicians & Surgeons, New York, United States of America
| | - Andrea Califano
- Systems Biology, Columbia University College of Physicians & Surgeons, New York, United States of America
| | - Domenico Accili
- Department of Medicine, Columbia University, New York, United States of America
| | - Utpal B Pajvani
- Department of Medicine, Columbia University, New York, United States of America
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Adams MT, Gilbert JM, Hinojosa Paiz J, Bowman FM, Blum B. Endocrine cell type sorting and mature architecture in the islets of Langerhans require expression of Roundabout receptors in β cells. Sci Rep 2018; 8:10876. [PMID: 30022126 PMCID: PMC6052079 DOI: 10.1038/s41598-018-29118-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/04/2018] [Indexed: 01/04/2023] Open
Abstract
Pancreatic islets of Langerhans display characteristic spatial architecture of their endocrine cell types. This architecture is critical for cell-cell communication and coordinated hormone secretion. Islet architecture is disrupted in type-2 diabetes. Moreover, the generation of architecturally correct islets in vitro remains a challenge in regenerative approaches to type-1 diabetes. Although the characteristic islet architecture is well documented, the mechanisms controlling its formation remain obscure. Here, we report that correct endocrine cell type sorting and the formation of mature islet architecture require the expression of Roundabout (Robo) receptors in β cells. Mice with whole-body deletion of Robo1 and conditional deletion of Robo2 either in all endocrine cells or selectively in β cells show complete loss of endocrine cell type sorting, highlighting the importance of β cells as the primary organizer of islet architecture. Conditional deletion of Robo in mature β cells subsequent to islet formation results in a similar phenotype. Finally, we provide evidence to suggest that the loss of islet architecture in Robo KO mice is not due to β cell transdifferentiation, cell death or loss of β cell differentiation or maturation.
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Affiliation(s)
- Melissa T Adams
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Jennifer M Gilbert
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Jesus Hinojosa Paiz
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Faith M Bowman
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Ave., Madison, WI, 53705, USA
| | - Barak Blum
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Ave., Madison, WI, 53705, USA.
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3
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Sandovici I, Hammerle CM, Cooper WN, Smith NH, Tarry-Adkins JL, Dunmore BJ, Bauer J, Andrews SR, Yeo GSH, Ozanne SE, Constância M. Ageing is associated with molecular signatures of inflammation and type 2 diabetes in rat pancreatic islets. Diabetologia 2016; 59:502-11. [PMID: 26699651 PMCID: PMC4742511 DOI: 10.1007/s00125-015-3837-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/17/2015] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS Ageing is a major risk factor for development of metabolic diseases such as type 2 diabetes. Identification of the mechanisms underlying this association could help to elucidate the relationship between age-associated progressive loss of metabolic health and development of type 2 diabetes. We aimed to determine molecular signatures during ageing in the endocrine pancreas. METHODS Global gene transcription was measured in pancreatic islets isolated from young and old rats by Ilumina BeadChip arrays. Promoter DNA methylation was measured by Sequenom MassArray in 46 genes that showed differential expression with age, and correlations with expression were established. Alterations in morphological and cellular processes with age were determined by immunohistochemical methods. RESULTS Age-related changes in gene expression were found at 623 loci (>1.5-fold, false discovery rate [FDR] <5%), with a significant (FDR < 0.05) enrichment in genes previously implicated in islet-cell function (Enpp1, Abcc8), type 2 diabetes (Tspan8, Kcnq1), inflammatory processes (Cxcl9, Il33) and extracellular matrix organisation (Col3a1, Dpt). Age-associated transcriptional differences negatively correlated with promoter DNA methylation at several loci related to inflammation, glucose homeostasis, cell proliferation and cell-matrix interactions (Il33, Cxcl9, Gpr119, Fbp2, Col3a1, Dpt, Spp1). CONCLUSIONS/INTERPRETATION Our findings suggest that a significant proportion of pancreatic islets develop a low-grade 'chronic' inflammatory status with ageing and this may trigger altered functional plasticity. Furthermore, we identified changes in expression of genes previously linked to type 2 diabetes and associated changes in DNA methylation that could explain their age-associated dysregulation. These findings provide new insights into key (epi)genetic signatures of the ageing process in islets.
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Affiliation(s)
- Ionel Sandovici
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
- Department of Obstetrics and Gynaecology, University of Cambridge, The Rosie Hospital, Robinson Way, Cambridge, CB2 0SW, UK
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
| | - Constanze M Hammerle
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
- Department of Obstetrics and Gynaecology, University of Cambridge, The Rosie Hospital, Robinson Way, Cambridge, CB2 0SW, UK
| | - Wendy N Cooper
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
- Department of Obstetrics and Gynaecology, University of Cambridge, The Rosie Hospital, Robinson Way, Cambridge, CB2 0SW, UK
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
| | - Noel H Smith
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
| | - Jane L Tarry-Adkins
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
| | - Benjamin J Dunmore
- Cambridge Genomic Services, Department of Pathology, University of Cambridge, Cambridge, UK
| | - Julien Bauer
- Cambridge Genomic Services, Department of Pathology, University of Cambridge, Cambridge, UK
| | | | - Giles S H Yeo
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK
- National Institute of Health Research, Cambridge Biomedical Research Centre, Cambridge, UK
| | - Susan E Ozanne
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK.
- National Institute of Health Research, Cambridge Biomedical Research Centre, Cambridge, UK.
| | - Miguel Constância
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 OQQ, UK.
- Department of Obstetrics and Gynaecology, University of Cambridge, The Rosie Hospital, Robinson Way, Cambridge, CB2 0SW, UK.
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK.
- National Institute of Health Research, Cambridge Biomedical Research Centre, Cambridge, UK.
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Ginseng berry extract supplementation improves age-related decline of insulin signaling in mice. Nutrients 2015; 7:3038-53. [PMID: 25912041 PMCID: PMC4425188 DOI: 10.3390/nu7043038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 03/23/2015] [Accepted: 04/10/2015] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to evaluate the effects of ginseng berry extract on insulin sensitivity and associated molecular mechanisms in aged mice. C57BL/6 mice (15 months old) were maintained on a regular diet (CON) or a regular diet supplemented with 0.05% ginseng berry extract (GBD) for 24 or 32 weeks. GBD-fed mice showed significantly lower serum insulin levels (p = 0.016) and insulin resistance scores (HOMA-IR) (p = 0.012), suggesting that GBD improved insulin sensitivity. Pancreatic islet hypertrophy was also ameliorated in GBD-fed mice (p = 0.007). Protein levels of tyrosine phosphorylated insulin receptor substrate (IRS)-1 (p = 0.047), and protein kinase B (AKT) (p = 0.037), were up-regulated in the muscle of insulin-injected GBD-fed mice compared with CON-fed mice. The expressions of forkhead box protein O1 (FOXO1) (p = 0.036) and peroxisome proliferator-activated receptor gamma (PPARγ) (p = 0.032), which are known as aging- and insulin resistance-related genes, were also increased in the muscle of GBD-fed mice. We conclude that ginseng berry extract consumption might increase activation of IRS-1 and AKT, contributing to the improvement of insulin sensitivity in aged mice.
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Singh H, Ganneru S, Malakapalli V, Chalasani M, Nappanveettil G, Bhonde RR, Venkatesan V. Islet adaptation to obesity and insulin resistance in WNIN/GR-Ob rats. Islets 2014; 6:e998099. [PMID: 25833252 PMCID: PMC4398287 DOI: 10.1080/19382014.2014.998099] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
WNIN/GR-Ob mutant rat is a novel animal model to study metabolic syndrome (obesity, insulin resistance, hyperinsulinemia, impaired glucose tolerance and cardiovascular diseases). We have investigated the islet characteristics of obese mutants at different age groups (1, 6 and 12 months) to assess the islet changes in response to early and chronic metabolic stress. Our data demonstrates altered islet cell morphology and function (hypertrophy, fibrotic lesions, vacuolation, decreased stimulation index, increased TNFα, ROS and TBARS levels) in mutants as compared to controls. Furthermore, network analysis (gene-gene interaction) studied in pancreas demonstrated increased inflammation as a key factor underlying obesity/metabolic syndrome in mutants. These observations pave way to explore this model to understand islet adaptation in response to metabolic syndrome.
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Key Words
- ANOVA, one-way analysis of variance
- BM-MSCs, bone marrow derived mesenchymal stem cells
- DAPI, 4′,6-diamidino-2-phenylindol
- DTZ, Dithizone
- FBG, fasting blood glucose
- H&E, hematoxylin and eosin stain
- HI, hyperinsulinemia
- HOMA-IR, homeostatic model assessment for insulin resistance
- IGT, impaired glucose tolerance
- IHC, immunohistochemistry
- IR, insulin resistance
- KRBH, krebs ringer bicarbonate
- MS, metabolic syndrome
- NCLAS, National Center for Laboratory Animal Sciences
- NIN, National Institute of Nutrition
- PBS, phosphate buffered saline
- ROS, reactive oxygen species
- SEM, scanning electron microscope
- T2D, type 2 diabetes
- TBARS, thiobarbituric acid reactive substances
- TEM, transmission electron microscopy
- TNFα, tumor necrosis factors
- WNIN, Wistar rats raised at National Institute of Nutrition
- WNIN/GR-Ob mutant rats
- hyperinsulinemia
- hypertrophy
- insulin resistance
- islets
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Affiliation(s)
- Himadri Singh
- Biochemistry/Stem Cell Research; National
Institute of Nutrition; Indian Council of Medical Research; Hyderabad,
India
| | - Sireesha Ganneru
- Biochemistry/Stem Cell Research; National
Institute of Nutrition; Indian Council of Medical Research; Hyderabad,
India
| | - Venkata Malakapalli
- Biochemistry/Stem Cell Research; National
Institute of Nutrition; Indian Council of Medical Research; Hyderabad,
India
| | - Maniprabha Chalasani
- Biochemistry/Stem Cell Research; National
Institute of Nutrition; Indian Council of Medical Research; Hyderabad,
India
| | - Giridharan Nappanveettil
- National Center for Laboratory Animal
Sciences; National Institute of Nutrition Hyderabad,
India
| | - Ramesh R Bhonde
- School of Regenerative Medicine; Manipal
University; Bangalore, India
| | - Vijayalakshmi Venkatesan
- Biochemistry/Stem Cell Research; National
Institute of Nutrition; Indian Council of Medical Research; Hyderabad,
India
- Correspondence to: Vijayalakshmi Venkatesan;
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Santos-Silva JC, Carvalho CPDF, de Oliveira RB, Boschero AC, Collares-Buzato CB. Cell-to-cell contact dependence and junctional protein content are correlated with in vivo maturation of pancreatic beta cells. Can J Physiol Pharmacol 2012; 90:837-50. [DOI: 10.1139/y2012-064] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In this study, we investigated the cellular distribution of junctional proteins and the dependence on cell–cell contacts of pancreatic beta cells during animal development. Fetus and newborn rat islets, which display a relatively poor insulin secretory response to glucose, present an immature morphology and cytoarchitecture when compared with young and adult islets that are responsive to glucose. At the perinatal stage, beta cells display a low junctional content of neural cell adhesion molecule (N-CAM), α- and β-catenins, ZO-1, and F-actin, while a differential distribution of N-CAM and Pan-cadherin was seen in beta cells and nonbeta cells only from young and adult islets. In the absence of intercellular contacts, the glucose-stimulated insulin secretion was completely blocked in adult beta cells, but after reaggregation they partially reestablished the secretory response to glucose. By contrast, neonatal beta cells were poorly responsive to sugar, regardless of whether they were arranged as intact islets or as isolated cells. Interestingly, after 10 days of culturing, neonatal beta cells, known to display increased junctional protein content in vitro, became responsive to glucose and concomitantly dependent on cell–cell contacts. Therefore, our data suggest that the developmental acquisition of an adult-like insulin secretory pattern is paralleled by a dependence on direct cell–cell interactions.
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Affiliation(s)
- Junia Carolina Santos-Silva
- Department of Histology and Embryology, Institute of Biology, University of Campinas (UNICAMP), Campinas CEP 13083-970, São Paulo, Brazil
| | - Carolina Prado de França Carvalho
- Department of Histology and Embryology, Institute of Biology, University of Campinas (UNICAMP), Campinas CEP 13083-970, São Paulo, Brazil
| | - Ricardo Beltrame de Oliveira
- Department of Histology and Embryology, Institute of Biology, University of Campinas (UNICAMP), Campinas CEP 13083-970, São Paulo, Brazil
| | - Antonio Carlos Boschero
- Department of Anatomy, Cell Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Carla Beatriz Collares-Buzato
- Department of Histology and Embryology, Institute of Biology, University of Campinas (UNICAMP), Campinas CEP 13083-970, São Paulo, Brazil
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Akimoto T, Terada M, Shimizu A. Progression of pancreatitis prior to diabetes onset in WBN/Kob-Lepr(fa) rats. J Vet Med Sci 2011; 74:65-70. [PMID: 21836382 DOI: 10.1292/jvms.11-0168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We established the WBN/Kob-Lepr(fa) rat as a new congenic strain for the fa allele of the leptin receptor gene (Lepr). Homozygous (fa/fa) WBN/Kob-Lepr(fa) rats provide a model of non-insulin-dependent diabetes, although its onset is secondary to pancreatitis. In the present study, we compared histopathological observations of pancreatitis in each genotype of this rat, to examine its suitability as a model of pancreatitis. The histopathological findings of the pancreatitis revealed intense changes dependent on age, such as hemorrhage or hemosiderin deposition. The pancreatitis in homozygous (fa/fa) WBN/Kob-Lepr(fa) rats were more severe than those of WBN/Kob rats.
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Affiliation(s)
- Toshio Akimoto
- Division of Laboratory Animal Science, Nippon Medical School, Tokyo, Japan.
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8
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Akimoto T, Terada M, Shimizu A, Sawai N, Ozawa H. The influence of dietary restriction on the development of diabetes and pancreatitis in female WBN/Kob-fatty rats. Exp Anim 2011; 59:623-30. [PMID: 21030790 DOI: 10.1538/expanim.59.623] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Original WBN/Kob male rats commonly develop chronic pancreatitis by the age of 3 months, while diabetes mellitus occurs at 9 months. In contrast, female rats of this strain do not show pancreatitis or diabetes. The WBN/Kob-fatty rat is a homozygous (fa/fa) congenic strain for the fa allele of the leptin receptor gene (Lepr). In WBN/Kob-fatty rats, both females and males provide a model of non-insulin-dependent diabetes with obesity. The leptin receptor fatty gene (Lepr(fa)) induces obesity and hyperphagia. In the present study, we examined the effect of dietary restriction on pancreatitis and diabetes in female WBN/Kob-fatty rats. Five female fatty rats comprised a restricted feeding group with paired-feeding from 3 to 13 weeks of age, and five female lean rats comprised a control group with paired-feeding. At 13 weeks of age, two of the five female fatty rats of the control group developed diabetes mellitus, while no female fatty rats of the restricted feeding group developed diabetes mellitus. At this stage, pathological changes of the pancreas were observed in female fatty rats. All female fatty rats showed severe interlobular, intra-lobular and intra-islet fibrosis. In female fatty rats of the restricted feeding group, pathological changes of the pancreas were milder those of the free-feeding fatty group. Although dietary restriction could not completely prevent pancreatitis in female fatty rats, the development of diabetes was inhibited by its reduction of the severity of pancreatitis.
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Affiliation(s)
- Toshio Akimoto
- Division of Laboratory Animal Science, Nippon Medical School, Tokyo, Japan
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9
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Masuyama T, Komeda K, Hara A, Noda M, Shinohara M, Oikawa T, Kanazawa Y, Taniguchi K. Chronological characterization of diabetes development in male Spontaneously Diabetic Torii rats. Biochem Biophys Res Commun 2004; 314:870-7. [PMID: 14741717 DOI: 10.1016/j.bbrc.2003.12.180] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To characterize the underlying mechanisms of diabetes development in males of the Spontaneously Diabetic Torii (SDT) rat, a novel spontaneous model for diabetes, we chronologically examined them, focusing on their diabetic features and the pathological changes in the pancreatic islets. Male SDT rats exhibited glucose intolerance with impaired insulin secretion after 14 weeks and developed diabetes with remarkable hyperglycemia and marked hypoinsulinemia after 20 weeks. At prediabetic stage (10-20 weeks), they were normoglycemic, but had significantly lower insulin levels of plasma and pancreas than the normal rats. Their beta-cell volume was already smaller significantly at 10 weeks than that of normal rats. The primary changes of the pancreatic islets were microvascular events such as congestion and hemorrhage at 8-10 weeks. Thereafter, the SDT rat islets were affected with inflammation and progressive fibrosis (at 10-20 weeks), and eventually atrophied with a loss of beta-cells (at 38 weeks). These results indicate that the male SDT rats develop spontaneous diabetes with an absolute decrease in the insulin secretory capacity of the islets.
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Affiliation(s)
- Taku Masuyama
- Torii Pharmaceutical Co. Ltd., 3-4-1 Nihonbashi-honcho, Chuo-ku, 103-8439, Tokyo, Japan.
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10
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Diani AR, Sawada G, Wyse B, Murray FT, Khan M. Pioglitazone preserves pancreatic islet structure and insulin secretory function in three murine models of type 2 diabetes. Am J Physiol Endocrinol Metab 2004; 286:E116-22. [PMID: 14532171 DOI: 10.1152/ajpendo.00331.2003] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Thiazolidinediones may slow the progression of type 2 diabetes by preserving pancreatic beta-cells. The effects of pioglitazone (PIO) on structure and function of beta-cells in KKA(y), C57BL/6J ob/ob, and C57BL/KsJ db/db mice (genetic models of type 2 diabetes) were examined. ob/ob (n = 7) and db/db (n = 9) mice were randomly assigned to 50-125 mg.kg body wt-1.day-1 of PIO in chow beginning at 6-10 wk of age. Control ob/ob (n = 7) and db/db mice (n = 9) were fed chow without PIO. KKA(y) mice (n = 15) were fed PIO daily at doses of 62-144 mg.kg body wt-1.day-1. Control KKA(y) mice (n = 10) received chow without PIO. Treatment continued until euthanasia at 14-26 wk of age. Blood was collected at baseline (before treatment) and just before euthanasia and was analyzed for glucose, glycosylated hemoglobin, and plasma insulin. Some of the splenic pancreas of each animal was resected and partially sectioned for light or electron microscopy. The remainder of the pancreas was assayed for insulin content. Compared with baseline and control groups, PIO treatment significantly reduced blood glucose and glycosylated hemoglobin levels. Plasma insulin levels decreased significantly in ob/ob mice treated with PIO. All groups treated with PIO exhibited significantly greater beta-cell granulation, evidence of reduced beta-cell stress, and 1.5- to 15-fold higher levels of pancreatic insulin. The data from these studies suggest that comparable effects would be expected to slow the progression of type 2 diabetes, either delaying or possibly preventing progression to an insulin-dependent state.
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Affiliation(s)
- A R Diani
- Pharmaceutical Research and Development, The Upjohn Company, Kalamazoo, MI 49007, USA
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11
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Wieczorek G, Pospischil A, Perentes E. A comparative immunohistochemical study of pancreatic islets in laboratory animals (rats, dogs, minipigs, nonhuman primates). EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY : OFFICIAL JOURNAL OF THE GESELLSCHAFT FUR TOXIKOLOGISCHE PATHOLOGIE 1998; 50:151-72. [PMID: 9681646 DOI: 10.1016/s0940-2993(98)80078-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The aim of the present study was to distinguish and describe the patterns of distribution of pancreatic islets within the pancreas of four species of laboratory animals, including rats, dogs, minipigs and monkeys, and furthermore, to identify immunohistochemically various islet cell types and characterize their content. Histopathological examinations were performed on sections stained with hematoxylin and eosin (H&E) and immunostained using rabbit polyclonal antibodies (pAb) against insulin, glucagon, pancreatic polypeptide (PP), somatostatin, chromogranin A, keratin, bombesin and gastrin, or mouse monoclonal antibodies (mAb) against synaptophysin, Leu-7 and proliferating cell nuclear antigen (PCNA) in three-step rabbit immunoperoxidase (PAP) and streptavidin/peroxidase (StreptABC/HRP) reactions. Positive immunohistochemical reactions were observed in the pancreatic islets of all animal species with all antibodies, except with anti-bombesin and anti-gastrin antibodies. Our results revealed that: 1) there is species specific regional arrangement of islets in the pancreas, 2) each species presents a characteristic distribution of cells producing different hormones. 3) immunoreactivity with immunohistochemical markers varies between species and/or age. The present comparative immunohistochemical study could be helpful for answering questions which are important for understanding some of the intricate mechanisms that govern the integrated function of the endocrine pancreas.
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Affiliation(s)
- G Wieczorek
- Experimental Pathology, Novartis Pharma AG, Basel, Switzerland
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