1
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Zinc and iron dynamics in human islet amyloid polypeptide-induced diabetes mouse model. Sci Rep 2023; 13:3484. [PMID: 36922503 PMCID: PMC10017767 DOI: 10.1038/s41598-023-30498-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/24/2023] [Indexed: 03/18/2023] Open
Abstract
Metal homeostasis is tightly regulated in cells and organisms, and its disturbance is frequently observed in some diseases such as neurodegenerative diseases and metabolic disorders. Previous studies suggest that zinc and iron are necessary for the normal functions of pancreatic β cells. However, the distribution of elements in normal conditions and the pathophysiological significance of dysregulated elements in the islet in diabetic conditions have remained unclear. In this study, to investigate the dynamics of elements in the pancreatic islets of a diabetic mouse model expressing human islet amyloid polypeptide (hIAPP): hIAPP transgenic (hIAPP-Tg) mice, we performed imaging analysis of elements using synchrotron scanning X-ray fluorescence microscopy and quantitative analysis of elements using inductively coupled plasma mass spectrometry. We found that in the islets, zinc significantly decreased in the early stage of diabetes, while iron gradually decreased concurrently with the increase in blood glucose levels of hIAPP-Tg mice. Notably, when zinc and/or iron were decreased in the islets of hIAPP-Tg mice, dysregulation of glucose-stimulated mitochondrial respiration was observed. Our findings may contribute to clarifying the roles of zinc and iron in islet functions under pathophysiological diabetic conditions.
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2
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Gordin D, Harjutsalo V, Tinsley L, Fickweiler W, Sun JK, Forsblom C, Amenta PS, Pober D, D'Eon S, Khatri M, Stillman IE, Groop PH, Keenan HA, King GL. Differential Association of Microvascular Attributions With Cardiovascular Disease in Patients With Long Duration of Type 1 Diabetes. Diabetes Care 2018; 41:815-822. [PMID: 29386250 PMCID: PMC5860842 DOI: 10.2337/dc17-2250] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/30/2017] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Independent association of chronic kidney disease (CKD) and proliferative diabetic retinopathy (PDR) with cardiovascular disease (CVD) has not been established. In the Joslin 50-Year Medalist study, characterizing individuals with type 1 diabetes for 50 years or more, we examined the associations of CKD and PDR with CVD, which was validated by another cohort with type 1 diabetes from Finland. RESEARCH DESIGN AND METHODS This cross-sectional study characterized U.S. residents (n = 762) with type 1 diabetes of 50 years or longer (Medalists) at a single site by questionnaire, clinical, ophthalmic, and laboratory studies. A replication cohort (n = 675) from the longitudinal Finnish Diabetic Nephropathy Study (FinnDiane) was used. CKD and PDR were defined as estimated glomerular filtration rate <45 mL/min/1.73 m2 (CKD stage 3b) and according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, respectively. CVD was based on questionnaires and/or hospital discharge registers. Associations of CVD status with CKD and PDR were analyzed by multivariable logistic regression. RESULTS CVD prevalence in the Medalists with CKD and without PDR (+CKD/-PDR) (n = 30) and CVD prevalence in the -CKD/+PDR group (n = 339) were half the prevalence in the +CKD/+PDR group (n = 66) (34.5% and 42.8% vs. 68.2%, P = 0.002). PDR status was independently associated with CVD (odds ratio 0.21 [95% CI 0.08-0.58], P = 0.003) in patients with CKD. Among the Finnish cohort, a trend toward a lower prevalence of CVD in the +CKD/-PDR group (n = 21) compared with the +CKD/+PDR group (n = 170) (19.1% vs. 37.1%, P = 0.10) was also observed. CONCLUSIONS Absence of PDR in people with type 1 diabetes and CKD was associated with a decreased prevalence of CVD, suggesting that common protective factors for PDR and CVD may exist.
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Affiliation(s)
- Daniel Gordin
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Valma Harjutsalo
- Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Helsinki, Finland.,Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland.,Chronic Disease Prevention Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Liane Tinsley
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Ward Fickweiler
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Jennifer K Sun
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Carol Forsblom
- Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Helsinki, Finland.,Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
| | - Peter S Amenta
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - David Pober
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Stephanie D'Eon
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Maya Khatri
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Isaac E Stillman
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA
| | - Per-Henrik Groop
- Abdominal Center Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki, Helsinki, Finland.,Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland.,Department of Diabetes, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Hillary A Keenan
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - George L King
- Dianne Nunnally Hoppes Laboratory Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
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3
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Krotee P, Rodriguez JA, Sawaya MR, Cascio D, Reyes FE, Shi D, Hattne J, Nannenga BL, Oskarsson ME, Philipp S, Griner S, Jiang L, Glabe CG, Westermark GT, Gonen T, Eisenberg DS. Atomic structures of fibrillar segments of hIAPP suggest tightly mated β-sheets are important for cytotoxicity. eLife 2017; 6. [PMID: 28045370 PMCID: PMC5207774 DOI: 10.7554/elife.19273] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/01/2016] [Indexed: 01/09/2023] Open
Abstract
hIAPP fibrils are associated with Type-II Diabetes, but the link of hIAPP structure to islet cell death remains elusive. Here we observe that hIAPP fibrils are cytotoxic to cultured pancreatic β-cells, leading us to determine the structure and cytotoxicity of protein segments composing the amyloid spine of hIAPP. Using the cryoEM method MicroED, we discover that one segment, 19-29 S20G, forms pairs of β-sheets mated by a dry interface that share structural features with and are similarly cytotoxic to full-length hIAPP fibrils. In contrast, a second segment, 15-25 WT, forms non-toxic labile β-sheets. These segments possess different structures and cytotoxic effects, however, both can seed full-length hIAPP, and cause hIAPP to take on the cytotoxic and structural features of that segment. These results suggest that protein segment structures represent polymorphs of their parent protein and that segment 19-29 S20G may serve as a model for the toxic spine of hIAPP.
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Affiliation(s)
- Pascal Krotee
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
| | - Jose A Rodriguez
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
| | - Michael R Sawaya
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
| | - Duilio Cascio
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
| | - Francis E Reyes
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Dan Shi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Johan Hattne
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Brent L Nannenga
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Marie E Oskarsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Stephan Philipp
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, United States
| | - Sarah Griner
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
| | - Lin Jiang
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, United States.,Brain Research Institute (BRI), University of California, Los Angeles, Los Angeles, United States
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, United States.,Biochemistry Department, Faculty of Science and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Tamir Gonen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - David S Eisenberg
- Department of Biological Chemistry, Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, United States.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, United States.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, United States
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4
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Meier DT, Entrup L, Templin AT, Hogan MF, Mellati M, Zraika S, Hull RL, Kahn SE. The S20G substitution in hIAPP is more amyloidogenic and cytotoxic than wild-type hIAPP in mouse islets. Diabetologia 2016; 59:2166-71. [PMID: 27393137 PMCID: PMC5026922 DOI: 10.1007/s00125-016-4045-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 06/15/2016] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS The S20G human islet amyloid polypeptide (hIAPP) substitution is associated with an earlier onset of type 2 diabetes in humans. Studies of synthetic S20G hIAPP in cell-free systems and immortalised beta cells have suggested that this may be due to increased hIAPP amyloidogenicity and cytotoxicity. Thus, using primary islets from mice with endogenous S20G hIAPP expression, we sought to determine whether the S20G gene mutation leads to increased amyloid-induced toxicity, beta cell loss and reduced beta cell function. METHODS Islets from mice in which mouse Iapp was replaced with human wild-type or S20G hIAPP were isolated and cultured in vitro under amyloid-forming conditions. Levels of insulin and hIAPP mRNA and protein, amyloid deposition and beta cell apoptosis and area, as well as glucose-stimulated insulin and hIAPP secretion, were quantified. RESULTS Islets expressing S20G hIAPP cultured in 16.7 mmol/l glucose demonstrated increased amyloid deposition and beta cell apoptosis, reduced beta cell area, decreased insulin content and diminished glucose-stimulated insulin secretion, compared with islets expressing wild-type hIAPP. Amyloid deposition and beta cell apoptosis were also increased when S20G islets were cultured in 11.1 mmol/l glucose (the concentration that is thought to be physiological for mouse islets). CONCLUSIONS/INTERPRETATION S20G hIAPP reduces beta cell number and function, thereby possibly explaining the earlier onset of type 2 diabetes in individuals carrying this gene mutation.
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Affiliation(s)
- Daniel T Meier
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Leon Entrup
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Andrew T Templin
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Meghan F Hogan
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Mahnaz Mellati
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Sakeneh Zraika
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Rebecca L Hull
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA
- University of Washington, Seattle, WA, USA
| | - Steven E Kahn
- VA Puget Sound Health Care System, 1660 S. Columbian Way, Seattle, WA, 98108, USA.
- University of Washington, Seattle, WA, USA.
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5
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Aston-Mourney K, Subramanian SL, Zraika S, Samarasekera T, Meier DT, Goldstein LC, Hull RL. One year of sitagliptin treatment protects against islet amyloid-associated β-cell loss and does not induce pancreatitis or pancreatic neoplasia in mice. Am J Physiol Endocrinol Metab 2013; 305:E475-84. [PMID: 23736544 PMCID: PMC3891222 DOI: 10.1152/ajpendo.00025.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin is an attractive therapy for diabetes, as it increases insulin release and may preserve β-cell mass. However, sitagliptin also increases β-cell release of human islet amyloid polypeptide (hIAPP), the peptide component of islet amyloid, which is cosecreted with insulin. Thus, sitagliptin treatment may promote islet amyloid formation and its associated β-cell toxicity. Conversely, metformin treatment decreases islet amyloid formation by decreasing β-cell secretory demand and could therefore offset sitagliptin's potential proamyloidogenic effects. Sitagliptin treatment has also been reported to be detrimental to the exocrine pancreas. We investigated whether long-term sitagliptin treatment, alone or with metformin, increased islet amyloid deposition and β-cell toxicity and induced pancreatic ductal proliferation, pancreatitis, and/or pancreatic metaplasia/neoplasia. hIAPP transgenic and nontransgenic littermates were followed for 1 yr on no treatment, sitagliptin, metformin, or the combination. Islet amyloid deposition, β-cell mass, insulin release, and measures of exocrine pancreas pathology were determined. Relative to untreated mice, sitagliptin treatment did not increase amyloid deposition, despite increasing hIAPP release, and prevented amyloid-induced β-cell loss. Metformin treatment alone or with sitagliptin decreased islet amyloid deposition to a similar extent vs untreated mice. Ductal proliferation was not altered among treatment groups, and no evidence of pancreatitis, ductal metaplasia, or neoplasia were observed. Therefore, long-term sitagliptin treatment stimulates β-cell secretion without increasing amyloid formation and protects against amyloid-induced β-cell loss. This suggests a novel effect of sitagliptin to protect the β-cell in type 2 diabetes that appears to occur without adverse effects on the exocrine pancreas.
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Affiliation(s)
- Kathryn Aston-Mourney
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, Washington
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6
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One year of sitagliptin treatment protects against islet amyloid-associated β-cell loss and does not induce pancreatitis or pancreatic neoplasia in mice. Am J Physiol Endocrinol Metab 2013. [PMID: 23736544 DOI: 10.1152/ajpendo] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The dipeptidyl peptidase-4 (DPP-4) inhibitor sitagliptin is an attractive therapy for diabetes, as it increases insulin release and may preserve β-cell mass. However, sitagliptin also increases β-cell release of human islet amyloid polypeptide (hIAPP), the peptide component of islet amyloid, which is cosecreted with insulin. Thus, sitagliptin treatment may promote islet amyloid formation and its associated β-cell toxicity. Conversely, metformin treatment decreases islet amyloid formation by decreasing β-cell secretory demand and could therefore offset sitagliptin's potential proamyloidogenic effects. Sitagliptin treatment has also been reported to be detrimental to the exocrine pancreas. We investigated whether long-term sitagliptin treatment, alone or with metformin, increased islet amyloid deposition and β-cell toxicity and induced pancreatic ductal proliferation, pancreatitis, and/or pancreatic metaplasia/neoplasia. hIAPP transgenic and nontransgenic littermates were followed for 1 yr on no treatment, sitagliptin, metformin, or the combination. Islet amyloid deposition, β-cell mass, insulin release, and measures of exocrine pancreas pathology were determined. Relative to untreated mice, sitagliptin treatment did not increase amyloid deposition, despite increasing hIAPP release, and prevented amyloid-induced β-cell loss. Metformin treatment alone or with sitagliptin decreased islet amyloid deposition to a similar extent vs untreated mice. Ductal proliferation was not altered among treatment groups, and no evidence of pancreatitis, ductal metaplasia, or neoplasia were observed. Therefore, long-term sitagliptin treatment stimulates β-cell secretion without increasing amyloid formation and protects against amyloid-induced β-cell loss. This suggests a novel effect of sitagliptin to protect the β-cell in type 2 diabetes that appears to occur without adverse effects on the exocrine pancreas.
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7
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Montane J, Klimek-Abercrombie A, Potter KJ, Westwell-Roper C, Bruce Verchere C. Metabolic stress, IAPP and islet amyloid. Diabetes Obes Metab 2012; 14 Suppl 3:68-77. [PMID: 22928566 DOI: 10.1111/j.1463-1326.2012.01657.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Amyloid forms within pancreatic islets in type 2 diabetes from aggregates of the β-cell peptide islet amyloid polypeptide (IAPP). These aggregates are toxic to β-cells, inducing β-cell death and dysfunction, as well as inciting islet inflammation. The β-cell is subject to a number of other stressors, including insulin resistance and hyperglycaemia, that may contribute to amyloid formation by increasing IAPP production by the β-cell. β-Cell dysfunction, evident as impaired glucose-stimulated insulin secretion and defective prohormone processing and exacerbated by metabolic stress, is also a likely prerequisite for islet amyloid formation to occur in type 2 diabetes. Islet transplants in patients with type 1 diabetes face similar stressors, and are subject to rapid amyloid formation and impaired proinsulin processing associated with progressive loss of β-cell function and mass. Declining β-cell mass is predicted to increase metabolic demand on remaining β-cells, promoting a feed-forward cycle of β-cell decline.
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Affiliation(s)
- J Montane
- Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
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8
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Keenan HA, Sun JK, Levine J, Doria A, Aiello LP, Eisenbarth G, Bonner-Weir S, King GL. Residual insulin production and pancreatic ß-cell turnover after 50 years of diabetes: Joslin Medalist Study. Diabetes 2010; 59:2846-53. [PMID: 20699420 PMCID: PMC2963543 DOI: 10.2337/db10-0676] [Citation(s) in RCA: 370] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To evaluate the extent of pancreatic β-cell function in a large number of insulin-dependent diabetic patients with a disease duration of 50 years or longer (Medalists). RESEARCH DESIGN AND METHODS Characterization of clinical and biochemical parameters and β-cell function of 411 Medalists with correlation with postmortem morphologic findings of 9 Medalists. RESULTS The Medalist cohort, with a mean ± SD disease duration and age of 56.2 ± 5.8 and 67.2 ± 7.5 years, respectively, has a clinical phenotype similar to type 1 diabetes (type 1 diabetes): mean ± SD onset at 11.0 ± 6.4 years, BMI at 26.0 ± 5.1 kg/m(2), insulin dose of 0.46 ± 0.2 u/kg, ∼94% positive for DR3 and/or DR4, and 29.5% positive for either IA2 or glutamic acid decarboxylase (GAD) autoantibodies. Random serum C-peptide levels showed that more than 67.4% of the participants had levels in the minimal (0.03-0.2 nmol/l) or sustained range (≥ 0.2 nmol/l). Parameters associated with higher random C-peptide were lower hemoglobin A1C, older age of onset, higher frequency of HLA DR3 genotype, and responsiveness to a mixed-meal tolerance test (MMTT). Over half of the Medalists with fasting C-peptide > 0.17 nmol/l responded in MMTT by a twofold or greater rise over the course of the test compared to fasting. Postmortem examination of pancreases from nine Medalists showed that all had insulin+ β-cells with some positive for TUNEL staining, indicating apoptosis. CONCLUSIONS Demonstration of persistence and function of insulin-producing pancreatic cells suggests the possibility of a steady state of turnover in which stimuli to enhance endogenous β cells could be a viable therapeutic approach in a significant number of patients with type 1 diabetes, even for those with chronic duration.
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Affiliation(s)
- Hillary A. Keenan
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Jennifer K. Sun
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Jared Levine
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Alessandro Doria
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Lloyd P. Aiello
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | | | - Susan Bonner-Weir
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - George L. King
- Research Division, Joslin Diabetes Center, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Corresponding author: George L. King,
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9
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Cheon EC, Strouch MJ, Barron MR, Ding Y, Melstrom LG, Krantz SB, Mullapudi B, Adrian K, Rao S, Adrian TE, Bentrem DJ, Grippo PJ. Alteration of strain background and a high omega-6 fat diet induces earlier onset of pancreatic neoplasia in EL-Kras transgenic mice. Int J Cancer 2010; 128:2783-92. [PMID: 20725998 DOI: 10.1002/ijc.25622] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 07/27/2010] [Indexed: 12/12/2022]
Abstract
Diets containing omega-6 (ω-6) fat have been associated with increased tumor development in carcinogen-induced pancreatic cancer models. However, the effects of ω-6 fatty acids and background strain on the development of genetically-induced pancreatic neoplasia is unknown. We assessed the effects of a diet rich in ω-6 fat on the development of pancreatic neoplasia in elastase (EL)-Kras(G12D) (EL-Kras) mice in two different backgrounds. EL-Kras FVB mice were crossed to C57BL/6 (B6) mice to produce EL-Kras FVB6 F1 (or EL-Kras F1) and EL-Kras B6 congenic mice. Age-matched EL-Kras mice from each strain were compared to one another on a standard chow. Two cohorts of EL-Kras FVB and EL-Kras F1 mice were fed a 23% corn oil diet and compared to age-matched mice fed a standard chow. Pancreata were scored for incidence, frequency, and size of neoplastic lesions, and stained for the presence of mast cells to evaluate changes in the inflammatory milieu secondary to a high fat diet. EL-Kras F1 mice had increased incidence, frequency, and size of pancreatic neoplasia compared to EL-Kras FVB mice. The frequency and size of neoplastic lesions and the weight and pancreatic mast cell densities in EL-Kras F1 mice were increased in mice fed a high ω-6 fatty acid diet compared to mice fed a standard chow. We herein introduce the EL-Kras B6 mouse model which presents with increased frequency of pancreatic neoplasia compared to EL-Kras F1 mice. The phenotype in EL-Kras F1 and FVB mice is promoted by a diet rich in ω-6 fatty acid.
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Affiliation(s)
- Eric C Cheon
- Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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10
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Nugent DA, Smith DM, Jones HB. A review of islet of Langerhans degeneration in rodent models of type 2 diabetes. Toxicol Pathol 2008; 36:529-51. [PMID: 18467681 DOI: 10.1177/0192623308318209] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Type 2 diabetes mellitus (TTDM) is characterized by progressive loss of glucose control through multifactorial mechanisms. The search for an understanding of TTDM has relied on animal models since the realization of the importance of the pancreas in controlling plasma glucose concentration. Rodent models of TTDM are developed to express hyperglycemia and not islet degeneration per se. Degeneration of the islets of Langerhans with beta-cell loss is secondary to insulin resistance and is regarded as the more important lesion. Despite this, differences between models are seen in the development and progression of islet degeneration. Assessing the differences between the models is important to appreciate the various aspects of TTDM and understand their advantages as well as their deficiencies. Relevant animal models of TTDM provide opportunities to investigate important physiological and cell biological processes that may ultimately lead to development of targeted therapies. This article reviews the importance, advantages, and limitations of rodent models of TTDM in relation to the histopathological changes that characterize islet degeneration. Pathophysiological mechanisms that contribute to islet degeneration are also discussed and are placed into the context of changes in islet histological appearances.
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Affiliation(s)
- David A Nugent
- Pathology Department, Safety Assessment, AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire, United Kingdom
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11
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Matveyenko AV, Butler PC. Islet amyloid polypeptide (IAPP) transgenic rodents as models for type 2 diabetes. ILAR J 2006; 47:225-33. [PMID: 16804197 DOI: 10.1093/ilar.47.3.225] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Blood glucose concentrations are maintained by insulin secreted from beta-cells located in the islets of Langerhans. There are approximately 2000 beta-cells per islet, and approximately one million islets of Langerhans scattered throughout the pancreas. The islet in type 2 diabetes mellitus (T2D) has deficient beta-cell mass due to increased beta-cell apoptosis and islet amyloid derived from islet amyloid polypeptide (IAPP). Accumulating evidence implicates toxic IAPP oligomers in the mediation of beta-cell apoptosis in T2D. Humans, monkeys, and cats express an amyloidogenic toxic form of IAPP and spontaneously develop diabetes characterized by islet amyloid deposits. However, longitudinal studies of islet pathology in humans are impossible, and studies in nonhuman primates and cats are costly and impractical. Rodent IAPP is not amyloidogenic, thus commonly used rodent models of diabetes do not recapitulate islet pathology in humans. To investigate the diabetogenic role of human IAPP (h-IAPP), several mouse models and, more recently, a rat model transgenic for h-IAPP have been developed. Studies in these models have revealed that the toxic effect of h-IAPP on beta-cell apoptosis demonstrates a threshold-dependent effect. Specifically, increasing h-IAPP transgene expression by breeding or induction of insulin resistance leads to increased beta-cell apoptosis and diabetes. These transgenic rodent models for h-IAPP provide an opportunity to elucidate the mechanisms responsible for h-IAPP-induced beta-cell apoptosis further and to test novel approaches to the prevention and treatment of T2D.
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Affiliation(s)
- Aleksey V Matveyenko
- Larry L. Hillblom Islet Research Center, University of California, David Geffen School of Medicine, Los Angeles, CA, USA
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