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Bergomi V, Beck S, Dobromylskyj M, Davison LJ, Wills JW, Hughes K. Insulin expression in β cells is reduced within islets before islet loss in diabetic cats. J Small Anim Pract 2022; 63:809-815. [PMID: 35986507 DOI: 10.1111/jsap.13541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/02/2022] [Accepted: 07/07/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVES Diabetes mellitus is a common condition that requires intensive treatment and markedly impacts the welfare of affected cats. The aim of this study was to identify diabetes mellitus-associated perturbations in the feline pancreatic islet microenvironment. The utility of "clear, unobstructed brain/body imaging cocktails and computational analysis" (CUBIC) for three-dimensional pancreatic analysis was investigated. METHODS Formalin-fixed paraffin-embedded tissues from cats with diabetes mellitus, or control cats without pancreatic pathology, were retrospectively identified. Immunohistochemistry for synaptophysin and ionised calcium binding adaptor molecule 1, and immunofluorescence for insulin and synaptophysin, were used to assess changes in islets. An image analysis pipeline was developed to analyse images acquired from two-dimensional immunofluorescence. CUBIC was used to optically clear selected pancreas samples before immunofluorescence and deep three-dimensional confocal microscopy. RESULTS Diabetic cats have a significant reduction in synaptophysin-positive islet area. Whilst islets from diabetic patients have similar numbers of β cells to islets from control cats, significantly lower intensity of insulin expression can be observed in the former. CUBIC facilitates clear visualisation of pancreatic islets in three dimensions. CLINICAL SIGNIFICANCE The data presented support the theory that there is a decrease in function of β cells before their destruction, suggesting a potentially significant step in the pathogenesis of feline diabetes mellitus. In parallel, we demonstrate CUBIC as a valuable new tool to visualise the shape of feline pancreatic islets and to interrogate pathology occurring in the islets of diabetic pets.
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Affiliation(s)
- V Bergomi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK.,Mercer & Hughes Veterinary Surgeons, Saffron Walden, CB11 3JB, UK
| | - S Beck
- VPG Histology, Horner Court, Bristol, BS7 0BJ, UK.,Independent Anatomic Pathology Ltd, Bath, UK
| | | | - L J Davison
- Department of Clinical Sciences and Services, Royal Veterinary College, Hatfield, UK.,Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - J W Wills
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK
| | - K Hughes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, UK
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2
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Smith AA, Moore KBE, Ambs PM, Saraswati AP, Fortin JS. Recent Advances in the Discovery of Therapeutics to Curtail Islet Amyloid Polypeptide Aggregation for Type 2 Diabetes Treatment. Adv Biol (Weinh) 2022; 6:e2101301. [PMID: 35931462 DOI: 10.1002/adbi.202101301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 07/04/2022] [Indexed: 01/28/2023]
Abstract
In humans with type 2 diabetes, at least 70% of patients exhibit islet amyloid plaques formed by misfolding islet amyloid polypeptides (IAPP). The oligomeric conformation and accumulation of the IAPP plaques lead to a panoply of cytotoxic effects on the islet β-cells. Currently, no marketed therapies for the prevention or elimination of these amyloid deposits exist, and therefore significant efforts are required to address this gap. To date, most of the experimental treatments are limited to only in vitro stages of testing. In general, the proposed therapeutics use various targeting strategies, such as binding to the N-terminal region of islet amyloid polypeptide on residues 1-19 or the hydrophobic region of IAPP. Other strategies include targeting the peptide self-assembly through π-stacking. These methods are realized by using several different families of compounds, four of which are highlighted in this review: naturally occurring products, small molecules, organometallic compounds, and nanoparticles. Each of these categories holds immense potential to optimize and develop inhibitor(s) of pancreatic amyloidosis in the near future.
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Affiliation(s)
- Alyssa A Smith
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Kendall B E Moore
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | | | - Akella Prasanth Saraswati
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Jessica S Fortin
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
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Jotha-Mattos L, Vieira AB, Castelo MDSM, Queiroz ASDM, de Souza HJM, de Alencar NX, Lima LMTR. Amyloidogenesis of feline amylin and plasma levels in cats with diabetes mellitus or pancreatitis. Domest Anim Endocrinol 2021; 74:106532. [PMID: 32841886 DOI: 10.1016/j.domaniend.2020.106532] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 12/12/2022]
Abstract
Amylin is a pancreatic hormone cosecreted along with insulin and involved in pancreatic amyloidosis and β-cell apoptosis in diabetic cats and humans. Amylin is usually elevated in early stages of type 2 diabetes but recently was found to be increased in acute and chronic pancreatitis in humans. Currently, there are little data about feline amylin propensity to fibrillate and no information on circulating levels of this hormone during feline pancreatitis. We compared 4 amylin analogues and found cat amylin to be more prone to amyloid fibrillation than human amylin, the triple-proline analogue pramlintide and rat amylin. We also measured plasma amylin levels in healthy lean cats, diabetic cats, and cats with pancreatitis. Plasma amylin was higher in diabetic cats compared with healthy lean cats (P < 0.001). Interestingly, amylin levels during pancreatitis were higher than those of both lean cats (P < 0.0001) and diabetic cats without pancreatitis (P < 0.005). These data support evidence of feline amylin being more prone to aggregation than human amylin in vitro, which may influence diabetes mellitus progression and β-cell failure in vivo. Furthermore, our data show an increase in amylin levels during feline pancreatitis and the need for future research on the role of this hormone in the pathogenesis of pancreatic inflammation associated to feline diabetes mellitus.
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Affiliation(s)
- L Jotha-Mattos
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro (UFRJ), CCS, Bss24, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil
| | - A B Vieira
- Biomedical Department, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, St. Kitts, West Indies.
| | - M da S M Castelo
- Universidade Federal Fluminense (UFF), Faculdade de Veterinária, R. Vital Brazil Filho, 64 - Santa Rosa, Niterói, RJ 24230-340, Brazil
| | - A S de M Queiroz
- Universidade Federal Fluminense (UFF), Faculdade de Veterinária, R. Vital Brazil Filho, 64 - Santa Rosa, Niterói, RJ 24230-340, Brazil
| | - H J M de Souza
- Escola de Medicina Veterinária, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil
| | - N X de Alencar
- Universidade Federal Fluminense (UFF), Faculdade de Veterinária, R. Vital Brazil Filho, 64 - Santa Rosa, Niterói, RJ 24230-340, Brazil
| | - L M T R Lima
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro (UFRJ), CCS, Bss24, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratory for Macromolecules, (LAMAC-DIMAV), National Institute for Metrology, Quality and Technology - INMETRO, Rio de Janeiro, Brazil.
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4
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Verma N, Ly H, Liu M, Chen J, Zhu H, Chow M, Hersh LB, Despa F. Intraneuronal Amylin Deposition, Peroxidative Membrane Injury and Increased IL-1β Synthesis in Brains of Alzheimer's Disease Patients with Type-2 Diabetes and in Diabetic HIP Rats. J Alzheimers Dis 2018; 53:259-72. [PMID: 27163815 DOI: 10.3233/jad-160047] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Amylin is a hormone synthesized and co-secreted with insulin by pancreatic β-cells that crosses the blood-brain barrier and regulates satiety. Amylin from humans (but not rodents) has an increased propensity to aggregate into pancreatic islet amyloid deposits that contribute to β-cell mass depletion and development of type-2 diabetes by inducing oxidative stress and inflammation. Recent studies demonstrated that aggregated amylin also accumulates in brains of Alzheimer's disease (AD) patients, preponderantly those with type-2 diabetes. Here, we report that, in addition to amylin plaques and mixed amylin-Aβ deposits, brains of diabetic patients with AD show amylin immunoreactive deposits inside the neurons. Neuronal amylin formed adducts with 4-hydroxynonenal (4-HNE), a marker of peroxidative membrane injury, and increased synthesis of the proinflammatory cytokine interleukin (IL)-1β. These pathological changes were mirrored in rats expressing human amylin in pancreatic islets (HIP rats) and mice intravenously injected with aggregated human amylin, but not in hyperglycemic rats secreting wild-type non-amyloidogenic rat amylin. In cultured primary hippocampal rat neurons, aggregated amylin increased IL-1β synthesis via membrane destabilization and subsequent generation of 4-HNE. These effects were blocked by membrane stabilizers and lipid peroxidation inhibitors. Thus, elevated circulating levels of aggregated amylin negatively affect the neurons causing peroxidative membrane injury and aberrant inflammatory responses independent of other confounding factors of diabetes. The present results are consistent with the pathological role of aggregated amylin in the pancreas, demonstrate a novel contributing mechanism to neurodegeneration, and suggest a direct, potentially treatable link of type-2 diabetes with AD.
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Affiliation(s)
- Nirmal Verma
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Han Ly
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Miao Liu
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Jing Chen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Haining Zhu
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Martin Chow
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Louis B Hersh
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
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Liu M, Verma N, Peng X, Srodulski S, Morris A, Chow M, Hersh LB, Chen J, Zhu H, Netea MG, Margulies KB, Despa S, Despa F. Hyperamylinemia Increases IL-1β Synthesis in the Heart via Peroxidative Sarcolemmal Injury. Diabetes 2016; 65:2772-83. [PMID: 27335231 PMCID: PMC5001184 DOI: 10.2337/db16-0044] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 06/09/2016] [Indexed: 12/29/2022]
Abstract
Hypersecretion of amylin is common in individuals with prediabetes, causes amylin deposition and proteotoxicity in pancreatic islets, and contributes to the development of type 2 diabetes. Recent studies also identified amylin deposits in failing hearts from patients with obesity or type 2 diabetes and demonstrated that hyperamylinemia accelerates the development of heart dysfunction in rats expressing human amylin in pancreatic β-cells (HIP rats). To further determine the impact of hyperamylinemia on cardiac myocytes, we investigated human myocardium, compared diabetic HIP rats with diabetic rats expressing endogenous (nonamyloidogenic) rat amylin, studied normal mice injected with aggregated human amylin, and developed in vitro cell models. We found that amylin deposition negatively affects cardiac myocytes by inducing sarcolemmal injury, generating reactive aldehydes, forming amylin-based adducts with reactive aldehydes, and increasing synthesis of the proinflammatory cytokine interleukin-1β (IL-1β) independently of hyperglycemia. These results are consistent with the pathological role of amylin deposition in the pancreas, uncover a novel contributing mechanism to cardiac myocyte injury in type 2 diabetes, and suggest a potentially treatable link of type 2 diabetes with diabetic heart disease. Although further studies are necessary, these data also suggest that IL-1β might function as a sensor of myocyte amylin uptake and a potential mediator of myocyte injury.
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Affiliation(s)
- Miao Liu
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Nirmal Verma
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Xiaoli Peng
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Sarah Srodulski
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Andrew Morris
- Division of Cardiovascular Medicine, Gill Heart Institute, University of Kentucky, Lexington, KY
| | - Martin Chow
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY
| | - Louis B Hersh
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY
| | - Jing Chen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY
| | - Haining Zhu
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY
| | - Mihai G Netea
- Department of Internal Medicine, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - Kenneth B Margulies
- Cardiovascular Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Sanda Despa
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
| | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY
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O'Neill DG, Gostelow R, Orme C, Church DB, Niessen SJM, Verheyen K, Brodbelt DC. Epidemiology of Diabetes Mellitus among 193,435 Cats Attending Primary-Care Veterinary Practices in England. J Vet Intern Med 2016; 30:964-72. [PMID: 27353396 PMCID: PMC5094533 DOI: 10.1111/jvim.14365] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 05/14/2016] [Accepted: 05/25/2016] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Diabetes mellitus (DM) is a common endocrine disease of cats. The prevalence of DM in cats in England is not well-defined. HYPOTHESIS/OBJECTIVES To estimate the prevalence and identify risk factors for DM in a large population of cats attending primary-care practices. ANIMALS A cohort of 193,563 cats in the VetCompass Programme attending 118 primary-care practices in England. METHODS Cross-sectional analysis of cohort clinical data. Data were extracted covering September 1st 2009 and August 31st 2014. Period prevalence of DM was calculated. Associations between risk factors and DM were assessed using logistic regression modelling. RESULTS Of 1,128 DM cases were identified among 194,563 cats (period prevalence 0.58%; 95% confidence interval [CI] 0.54-0.61). Multivariable modelling indicated that Tonkinese (OR 4.1; 95% CI 1.8-9.6; P = .001), Norwegian Forest (odds ratio [OR] 3.5; 95% CI 1.3-9.6; P = .001) and Burmese (OR 3.0; 95% CI 2.0-4.4; P < .001) cats had increased odds of DM compared with crossbred cats. DM odds increased as bodyweight categories increased above 4 kg (P < .001), as cats aged beyond 6 years old (P < .001) and in insured cats (OR 2.0; 95% CI 1.6-2.4; P < .001) but sex was not significantly associated with DM. CONCLUSIONS AND CLINICAL IMPORTANCE Diabetes mellitus is an important component of the primary-care practice caseload with 1-in-200 cats affected. An increased risk of DM in certain cat breeds supports a genetic predisposition. These results can guide future research and preventative healthcare.
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Affiliation(s)
- D G O'Neill
- Department of Production and Population Health
| | - R Gostelow
- Department of Clinical Science and Services
| | - C Orme
- Department of Clinical Science and Services
| | - D B Church
- Department of Clinical Science and Services
| | | | - K Verheyen
- Department of Production and Population Health
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Osto M, Lutz TA. Translational value of animal models of obesity-Focus on dogs and cats. Eur J Pharmacol 2015; 759:240-52. [PMID: 25814247 DOI: 10.1016/j.ejphar.2015.03.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 01/15/2015] [Accepted: 03/12/2015] [Indexed: 12/11/2022]
Abstract
A prolonged imbalance between a relative increase in energy intake over a decrease in energy expenditure results in the development of obesity; extended periods of a positive energy balance eventually lead to the accumulation of abnormally high amounts of fat in adipose tissue but also in other organs. Obesity is considered a clinical state of impaired general heath in which the excessive increase in adipose tissue mass may be associated with metabolic disorders such as type 2 diabetes mellitus, hyperlipidemia, hypertension and cardiovascular diseases. This review discusses briefly the use of animal models for the study of obesity and its comorbidities. Generally, most studies are performed with rodents, such as diet induced obesity and genetic models. Here, we focus specifically on two different species, namely dogs and cats. Obese dogs and cats show many features of human obesity. Interestingly, however, dogs and cats differ from each other in certain aspects because even though obese dogs may become insulin resistant, this does not result in the development of diabetes mellitus. In fact, diabetes in dogs is typically not associated with obesity because dogs present a type 1 diabetes-like syndrome. On the other hand, obese cats often develop diabetes mellitus which shares many features with human type 2 diabetes; feline and human diabetes are similar in respect to their pathophysiology, underlying risk factors and treatment strategies. Our review discusses genetic and endocrine factors in obesity, discusses obesity induced changes in lipid metabolism and includes some recent findings on the role of gut microbiota in obesity. Compared to research in rodent models, the array of available techniques and tools is unfortunately still rather limited in dogs and cats. Hence, even though physiological and pathophysiological phenomena are well described in dogs and cats, the underlying mechanisms are often not known and studies investigating causality specifically are scarce.
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Affiliation(s)
- Melania Osto
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, CH 8057 Zurich, Switzerland
| | - Thomas A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, CH 8057 Zurich, Switzerland; Institute of Laboratory Animal Science, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 190, CH 8057 Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, CH 8057 Zurich, Switzerland.
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