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Tarhan M, Hartl T, Shchyglo O, Colitti-Klausnitzer J, Kuhla A, Breuer TM, Manahan-Vaughan D. Changes in hippocampal volume, synaptic plasticity and amylin sensitivity in an animal model of type 2 diabetes are associated with increased vulnerability to amyloid-beta in advancing age. Front Aging Neurosci 2024; 16:1373477. [PMID: 38974903 PMCID: PMC11224464 DOI: 10.3389/fnagi.2024.1373477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 05/28/2024] [Indexed: 07/09/2024] Open
Abstract
Type-2 diabetes (T2D) is a metabolic disorder that is considered a risk factor for Alzheimer's disease (AD). Cognitive impairment can arise due to hypoglycemia associated with T2D, and hyperamylinemia associated with insulin resistance can enhance AD pathology. We explored whether changes occur in the hippocampus in aging (6-12 months old) female V-Lep○b-/- transgenic (tg) mice, comprising an animal model of T2D. We also investigated whether an increase in vulnerability to Aβ (1-42), a known pathological hallmark of AD, is evident. Using magnetic resonance imaging we detected significant decreases in hippocampal brain volume in female tg-mice compared to wild-type (wt) littermates. Long-term potentiation (LTP) was impaired in tg compared to wt mice. Treatment of the hippocampus with Aβ (1-42) elicited a stronger debilitation of LTP in tg compared to wt mice. Treatment with an amylin antagonist (AC187) significantly enhanced LTP in wt and tg mice, and rescued LTP in Aβ (1-42)-treated tg mice. Taken together our data indicate that a T2D-like state results in an increased vulnerability of the hippocampus to the debilitating effects of Aβ (1-42) and that effects are mediated in part by changes in amylin receptor signaling.
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Affiliation(s)
- Melih Tarhan
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
| | - Tim Hartl
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
| | - Olena Shchyglo
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
| | | | - Angela Kuhla
- Rudolf Zenker Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | | | - Denise Manahan-Vaughan
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
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2
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Morisseau L, Tokito F, Lucas M, Poulain S, Kim SH, Plaisance V, Pawlowski V, Legallais C, Jellali R, Sakai Y, Abderrahmani A, Leclerc E. Transcriptomic profiling analysis of the effect of palmitic acid on 3D spheroids of β-like cells derived from induced pluripotent stem cells. Gene 2024; 917:148441. [PMID: 38608795 DOI: 10.1016/j.gene.2024.148441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024]
Abstract
Type 2 diabetes (T2D) is posing a serious public health concern with a considerable impact on human life and health expenditures worldwide. The disease develops when insulin plasma level is insufficient for coping insulin resistance, caused by the decline of pancreatic β-cell function and mass. In β-cells, the lipotoxicity exerted by saturated free fatty acids in particular palmitate (PA), which is chronically elevated in T2D, plays a major role in β-cell dysfunction and mass. However, there is a lack of human relevant in vitro model to identify the underlying mechanism through which palmitate induces β-cell failure. In this frame, we have previously developed a cutting-edge 3D spheroid model of β-like cells derived from human induced pluripotent stem cells. In the present work, we investigated the signaling pathways modified by palmitate in β-like cells derived spheroids. When compared to the 2D monolayer cultures, the transcriptome analysis (FDR set at 0.1) revealed that the 3D spheroids upregulated the pancreatic markers (such as GCG, IAPP genes), lipids metabolism and transporters (CD36, HMGSC2 genes), glucose transporter (SLC2A6). Then, the 3D spheroids are exposed to PA 0.5 mM for 72 h. The differential analysis demonstrated that 32 transcription factors and 135 target genes were mainly modulated (FDR set at 0.1) including the upregulation of lipid and carbohydrates metabolism (HMGSC2, LDHA, GLUT3), fibrin metabolism (FGG, FGB), apoptosis (CASP7). The pathway analysis using the 135 selected targets extracted the fibrin related biological process and wound healing in 3D PA treated conditions. An overall pathway gene set enrichment analysis, performed on the overall gene set (with pathway significance cutoff at 0.2), highlighted that PA perturbs the citrate cycle, FOXO signaling and Hippo signaling as observed in human islets studies. Additional RT-PCR confirmed induction of inflammatory (IGFBP1, IGFBP3) and cell growth (CCND1, Ki67) pathways by PA. All these changes were associated with unaffected glucose-stimulated insulin secretion (GSIS), suggesting that they precede the defect of insulin secretion and death induced by PA. Overall, we believe that our data demonstrate the potential of our spheroid 3D islet-like cells to investigate the pancreatic-like response to diabetogenic environment.
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Affiliation(s)
- Lisa Morisseau
- Université de Technologie de Compiègne, CNRS, Biomechanics and Bioengineering, Centre de recherche Royallieu CS 60319, 60203 Compiègne Cedex, France
| | - Fumiya Tokito
- Department of Chemical Engineering, Faculty of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Mathilde Lucas
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Stéphane Poulain
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Soo Hyeon Kim
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Valérie Plaisance
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Valérie Pawlowski
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Cécile Legallais
- Université de Technologie de Compiègne, CNRS, Biomechanics and Bioengineering, Centre de recherche Royallieu CS 60319, 60203 Compiègne Cedex, France
| | - Rachid Jellali
- Université de Technologie de Compiègne, CNRS, Biomechanics and Bioengineering, Centre de recherche Royallieu CS 60319, 60203 Compiègne Cedex, France
| | - Yasuyuki Sakai
- Department of Chemical Engineering, Faculty of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan; CNRS/IIS IRL 2820, Laboratory for Integrated Micro Mechatronic Systems, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Amar Abderrahmani
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Eric Leclerc
- CNRS/IIS IRL 2820, Laboratory for Integrated Micro Mechatronic Systems, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
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3
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Lin Q, Liu J, Chen H, Hu W, Lei W, Wang M, Lin X, Zhang Y, Ai H, Chen S, Li C. A Novel Peptide COX 52-69 Inhibits High Glucose-induced Insulin Secretion by Modulating BK Channel Activity. Curr Protein Pept Sci 2024; 25:419-426. [PMID: 37885106 DOI: 10.2174/0113892037249620231010063637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 08/21/2023] [Accepted: 09/03/2023] [Indexed: 10/28/2023]
Abstract
BACKGROUND Excessive insulin is the leading cause of metabolic syndromes besides hyperinsulinemia. Insulin-lowering therapeutic peptides have been poorly studied and warrant urgent attention. OBJECTIVES The main purpose of this study, was to introduce a novel peptide COX52-69 that was initially isolated from the porcine small intestine and possessed the ability to inhibit insulin secretion under high-glucose conditions by modulating large conductance Ca2+-activated K+ channels (BK channels) activity. METHODS AND RESULTS Enzyme-linked immunosorbent assay results indicate that COX52-69 supressed insulin release induced by high glucose levels in pancreatic islets and animal models. Furthermore, electrophysiological data demonstrated that COX52-69 can increase BK channel currents and hyperpolarize cell membranes. Thus, cell excitability decreased, corresponding to a reduction in insulin secretion. CONCLUSION Our study provides a novel approach to modulate high glucose-stimulated insulin secretion in patients with hyperinsulinemia.
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Affiliation(s)
- Qian Lin
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Jingtao Liu
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Hengling Chen
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Wenwu Hu
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Weiqiong Lei
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Meijie Wang
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Xianguang Lin
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Yongning Zhang
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Huiting Ai
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Su Chen
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
| | - Chenhong Li
- Laboratory of Membrane Ion Channels and Medicine, Key Laboratory of Cognitive Science of State Ethnic Affairs Commission, Hubei Key Laboratory of Medical Information Analysis and Tumor Diagnosis and Treatment, College of Biomedical Engineering, South-Central Minzu University, Wuhan, Hubei, 430074, China
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4
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Serbis A, Giapros V, Tsamis K, Balomenou F, Galli-Tsinopoulou A, Siomou E. Beta Cell Dysfunction in Youth- and Adult-Onset Type 2 Diabetes: An Extensive Narrative Review with a Special Focus on the Role of Nutrients. Nutrients 2023; 15:2217. [PMID: 37432389 PMCID: PMC10180650 DOI: 10.3390/nu15092217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 07/12/2023] Open
Abstract
Traditionally a disease of adults, type 2 diabetes (T2D) has been increasingly diagnosed in youth, particularly among adolescents and young adults of minority ethnic groups. Especially, during the recent COVID-19 pandemic, obesity and prediabetes have surged not only in minority ethnic groups but also in the general population, further raising T2D risk. Regarding its pathogenesis, a gradually increasing insulin resistance due to central adiposity combined with a progressively defective β-cell function are the main culprits. Especially in youth-onset T2D, a rapid β-cell activity decline has been observed, leading to higher treatment failure rates, and early complications. In addition, it is well established that both the quantity and quality of food ingested by individuals play a key role in T2D pathogenesis. A chronic imbalance between caloric intake and expenditure together with impaired micronutrient intake can lead to obesity and insulin resistance on one hand, and β-cell failure and defective insulin production on the other. This review summarizes our evolving understanding of the pathophysiological mechanisms involved in defective insulin secretion by the pancreatic islets in youth- and adult-onset T2D and, further, of the role various micronutrients play in these pathomechanisms. This knowledge is essential if we are to curtail the serious long-term complications of T2D both in pediatric and adult populations.
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Affiliation(s)
- Anastasios Serbis
- Department of Pediatrics, School of Medicine, University of Ioannina, St. Niarhcos Avenue, 45500 Ioannina, Greece;
| | - Vasileios Giapros
- Neonatal Intensive Care Unit, School of Medicine, University of Ioannina, St. Νiarhcos Avenue, 45500 Ioannina, Greece (F.B.)
| | - Konstantinos Tsamis
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Ioannina, St. Niarhcos Avenue, 45500 Ioannina, Greece
| | - Foteini Balomenou
- Neonatal Intensive Care Unit, School of Medicine, University of Ioannina, St. Νiarhcos Avenue, 45500 Ioannina, Greece (F.B.)
| | - Assimina Galli-Tsinopoulou
- Second Department of Pediatrics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, AHEPA University Hospital, Stilponos Kyriakidi 1, 54636 Thessaloniki, Greece;
| | - Ekaterini Siomou
- Department of Pediatrics, School of Medicine, University of Ioannina, St. Niarhcos Avenue, 45500 Ioannina, Greece;
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5
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Khan D, Moffett RC, Flatt PR, Tarasov AI. Classical and non-classical islet peptides in the control of β-cell function. Peptides 2022; 150:170715. [PMID: 34958851 DOI: 10.1016/j.peptides.2021.170715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/25/2021] [Accepted: 12/17/2021] [Indexed: 12/25/2022]
Abstract
The dual role of the pancreas as both an endocrine and exocrine gland is vital for food digestion and control of nutrient metabolism. The exocrine pancreas secretes enzymes into the small intestine aiding digestion of sugars and fats, whereas the endocrine pancreas secretes a cocktail of hormones into the blood, which is responsible for blood glucose control and regulation of carbohydrate, protein and fat metabolism. Classical islet hormones, insulin, glucagon, pancreatic polypeptide and somatostatin, interact in an autocrine and paracrine manner, to fine-tube the islet function and insulin secretion to the needs of the body. Recently pancreatic islets have been reported to express a number of non-classical peptide hormones involved in metabolic signalling, whose major production site was believed to reside outside pancreas, e.g. in the small intestine. We highlight the key non-classical islet peptides, and consider their involvement, together with established islet hormones, in regulation of stimulus-secretion coupling as well as proliferation, survival and transdifferentiation of β-cells. We furthermore focus on the paracrine interaction between classical and non-classical islet hormones in the maintenance of β-cell function. Understanding the functional relationships between these islet peptides might help to develop novel, more efficient treatments for diabetes and related metabolic disorders.
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Affiliation(s)
- Dawood Khan
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK.
| | - R Charlotte Moffett
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Peter R Flatt
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Andrei I Tarasov
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
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6
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Sarnobat D, Charlotte Moffett R, Flatt PR, Irwin N, Tarasov AI. GABA and insulin but not nicotinamide augment α- to β-cell transdifferentiation in insulin-deficient diabetic mice. Biochem Pharmacol 2022; 199:115019. [DOI: 10.1016/j.bcp.2022.115019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 12/30/2022]
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7
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Abstract
Protein aggregation and amyloid formation are pathogenic events underlying the development of an increasingly large number of human diseases named “proteinopathies”. Abnormal accumulation in affected tissues of amyloid β (Aβ) peptide, islet amyloid polypeptide (IAPP), and the prion protein, to mention a few, are involved in the occurrence of Alzheimer’s (AD), type 2 diabetes mellitus (T2DM) and prion diseases, respectively. Many reports suggest that the toxic properties of amyloid aggregates are correlated with their ability to damage cell membranes. However, the molecular mechanisms causing toxic amyloid/membrane interactions are still far to be completely elucidated. This review aims at describing the mutual relationships linking abnormal protein conformational transition and self-assembly into amyloid aggregates with membrane damage. A cross-correlated analysis of all these closely intertwined factors is thought to provide valuable insights for a comprehensive molecular description of amyloid diseases and, in turn, the design of effective therapies.
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8
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FoxA2 and RNA Pol II mediate human islet amyloid polypeptide turnover in ER-stressed pancreatic β-cells. Biochem J 2021; 478:1261-1282. [PMID: 33650632 DOI: 10.1042/bcj20200984] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 12/25/2022]
Abstract
Here, we investigated transcriptional and trafficking mechanisms of human islet amyloid polypeptide (hIAPP) in normal and stressed β-cells. In high glucose-challenged human islets and rat insulinoma cells overexpressing hIAPP, cell fractionation studies revealed increased accumulation of hIAPP. Unexpectedly, a significant fraction (up to 22%) of hIAPP was found in the nuclear soluble and chromatin-enriched fractions of cultured human islet and rat insulinoma cells. The nucleolar accumulation of monomeric forms of hIAPP did not have any adverse effect on the proliferation of β-cells nor did it affect nucleolar organization or function. However, intact nucleolar organization and function were essential for hIAPP expression under normal and ER-stress conditions as RNA polymerase II inhibitor, α-amanitin, reduced hIAPP protein expression evoked by high glucose and thapsigargin. Promoter activity studies revealed the essential role of transcription factor FoxA2 in hIAPP promoter activation in ER-stressed β-cells. Transcriptome and secretory studies demonstrate that the biosynthetic and secretory capacity of islet β-cells was preserved during ER stress. Thus, the main reason for increased intracellular hIAPP accumulation is its enhanced biosynthesis under these adverse conditions.
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9
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Sánchez-Gómez A, Alcarraz-Vizán G, Fernández M, Fernández-Santiago R, Ezquerra M, Cámara A, Serrano M, Novials A, Muñoz E, Valldeoriola F, Compta Y, Martí MJ. Peripheral insulin and amylin levels in Parkinson's disease. Parkinsonism Relat Disord 2020; 79:91-96. [DOI: 10.1016/j.parkreldis.2020.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/26/2020] [Accepted: 08/12/2020] [Indexed: 01/12/2023]
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10
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Bishoyi AK, Roham PH, Rachineni K, Save S, Hazari MA, Sharma S, Kumar A. Human islet amyloid polypeptide (hIAPP) - a curse in type II diabetes mellitus: insights from structure and toxicity studies. Biol Chem 2020; 402:133-153. [PMID: 33544470 DOI: 10.1515/hsz-2020-0174] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
The human islet amyloid polypeptide (hIAPP) or amylin, a neuroendocrine peptide hormone, is known to misfold and form amyloidogenic aggregates that have been observed in the pancreas of 90% subjects with Type 2 Diabetes Mellitus (T2DM). Under normal physiological conditions, hIAPP is co-stored and co-secreted with insulin; however, under chronic hyperglycemic conditions associated with T2DM, the overexpression of hIAPP occurs that has been associated with the formation of amyloid deposits; as well as the death and dysfunction of pancreatic β-islets in T2DM. Hitherto, various biophysical and structural studies have shown that during this process of aggregation, the peptide conformation changes from random structure to helix, then to β-sheet, subsequently to cross β-sheets, which finally form left-handed helical aggregates. The intermediates, formed during this process, have been shown to induce higher cytotoxicity in the β-cells by inducing cell membrane disruption, endoplasmic reticulum stress, mitochondrial dysfunction, oxidative stress, islet inflammation, and DNA damage. As a result, several research groups have attempted to target both hIAPP aggregation phenomenon and the destabilization of preformed fibrils as a therapeutic intervention for T2DM management. In this review, we have summarized structural aspects of various forms of hIAPP viz. monomer, oligomers, proto-filaments, and fibrils of hIAPP. Subsequently, cellular toxicity caused by toxic conformations of hIAPP has been elaborated upon. Finally, the need for performing structural and toxicity studies in vivo to fill in the gap between the structural and cellular aspects has been discussed.
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Affiliation(s)
- Ajit Kumar Bishoyi
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Pratiksha H Roham
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Kavitha Rachineni
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shreyada Save
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - M Asrafuddoza Hazari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shilpy Sharma
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Ashutosh Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
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11
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Viswanathan GK, Paul A, Gazit E, Segal D. Naphthoquinone Tryptophan Hybrids: A Promising Small Molecule Scaffold for Mitigating Aggregation of Amyloidogenic Proteins and Peptides. Front Cell Dev Biol 2019; 7:242. [PMID: 31750300 PMCID: PMC6843079 DOI: 10.3389/fcell.2019.00242] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 10/02/2019] [Indexed: 12/22/2022] Open
Abstract
A current challenge faced by researchers is the lack of disease-modifying therapeutics for amyloid formation that is associated with several human diseases. Although the monomeric proteins or peptides involved in various amyloidogenic diseases do not have amino acid sequence homology, there appears to be a structural correlation among the amyloid assemblies, which are responsible for distinct pathological conditions. Here, we review our work on Naphthoquinone Tryptophan (NQTrp) hybrids, a small molecule scaffold that can generically modulate neuronal and non-neuronal amyloid aggregation both in vitro and in vivo. NQTrp reduces the net amyloid load by inhibiting the process of amyloid formation and disassembling the pre-formed fibrils, both in a dose-dependent manner. As a plausible mechanism of action, NQTrp effectively forms hydrogen bonding and hydrophobic interactions, such as π-π stacking, with the vital residues responsible for the initial nucleation of protein/peptide aggregation. This review highlights the effectiveness of the NQTrp hybrid scaffold for developing novel small molecule modulators of amyloid aggregation.
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Affiliation(s)
- Guru KrishnaKumar Viswanathan
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Ashim Paul
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Tel Aviv, Israel.,Interdisciplinary Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
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12
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Xi XX, Sun J, Chen HC, Chen AD, Gao LP, Yin J, Jing YH. High-Fat Diet Increases Amylin Accumulation in the Hippocampus and Accelerates Brain Aging in hIAPP Transgenic Mice. Front Aging Neurosci 2019; 11:225. [PMID: 31507407 PMCID: PMC6718729 DOI: 10.3389/fnagi.2019.00225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/08/2019] [Indexed: 12/23/2022] Open
Abstract
The accumulation of human islet amyloid polypeptide (hIAPP) in pancreatic islets under induction by a high-fat diet plays a critical role in the development of type-2 diabetes mellitus (T2DM). T2DM is a risk factor of late-onset Alzheimer’s disease (AD). Nevertheless, whether hIAPP in combination with hyperlipidemia may lead to AD-like pathological changes in the brain remains unclear. hIAPP transgenic mice were fed with a high-fat diet for 6 or 12 months to establish the T2DM model. The accumulation of amylin, the numbers of Fluoro-Jade C (FJC)-positive and β-gal positive cells, and the deposition level of Aβ42 in the hippocampi of the transgenic mice were detected by using brain sections. Cytoplasmic and membrane proteins were extracted from the hippocampi of the transgenic mice, and the ratio of membrane GLUT4 expression to cytoplasmic GLUT4 expression was measured through Western blot analysis. Changes in the cognitive functions of hIAPP transgenic mice after 12 months of feeding with a high-fat diet were evaluated. hIAPP transgenic mice fed with a high-fat diet for 6 or 12 months showed elevated blood glucose levels and insulin resistance; increased amylin accumulation, number of FJC-positive and β-gal positive cells, and Aβ42 deposition in the hippocampi; and reduced membrane GLUT4 expression levels. hIAPP transgenic mice fed with a high-fat diet for 12 months showed reductions in social cognitive ability and passive learning ability. A high-fat diet increased amylin accumulation in the hippocampi of hIAPP transgenic mice, which presented AD-like pathology and behavior characterized by neural degeneration, brain aging, Aβ42 deposition, and impaired glucose utilization and cognition.
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Affiliation(s)
- Xiao-Xia Xi
- Center of Experimental Animal, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Jing Sun
- Center of Experimental Animal, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Hai-Chao Chen
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China
| | - An-Di Chen
- School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, China
| | - Li-Ping Gao
- School of Basic Medical Sciences, Institute of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, China
| | - Jie Yin
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China
| | - Yu-Hong Jing
- School of Basic Medical Sciences, Institute of Anatomy and Histology & Embryology, Neuroscience, Lanzhou University, Lanzhou, China.,Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
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IAPP in type II diabetes: Basic research on structure, molecular interactions, and disease mechanisms suggests potential intervention strategies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.02.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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14
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Kiriyama Y, Nochi H. Role and Cytotoxicity of Amylin and Protection of Pancreatic Islet β-Cells from Amylin Cytotoxicity. Cells 2018; 7:cells7080095. [PMID: 30082607 PMCID: PMC6115925 DOI: 10.3390/cells7080095] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/28/2018] [Accepted: 08/01/2018] [Indexed: 12/26/2022] Open
Abstract
Amylin, (or islet amyloid polypeptide; IAPP), a 37-amino acid peptide hormone, is released in response to nutrients, including glucose, lipids or amino acids. Amylin is co-stored and co-secreted with insulin by pancreatic islet β-cells. Amylin inhibits food intake, delays gastric emptying, and decreases blood glucose levels, leading to the reduction of body weight. Therefore, amylin as well as insulin play important roles in controlling the level of blood glucose. However, human amylin aggregates and human amylin oligomers cause membrane disruption, endoplasmic reticulum (ER) stress and mitochondrial damage. Since cytotoxicity of human amylin oligomers to pancreatic islet β-cells can lead to diabetes, the protection of pancreatic islet β cells from cytotoxic amylin is crucial. Human amylin oligomers also inhibit autophagy, although autophagy can function to remove amylin aggregates and damaged organelles. Small molecules, including β-sheet breaker peptides, chemical chaperones, and foldamers, inhibit and disaggregate amyloid formed by human amylin, suggesting the possible use of these small molecules in the treatment of diabetes. In this review, we summarize recent findings regarding the role and cytotoxicity of amylin and the protection of pancreatic islet β-cells from cytotoxicity of amylin.
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Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Kagawa, Sanuki 769-2193, Japan.
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Kagawa, Sanuki 769-2193, Japan.
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15
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Kitamoto T, Sakurai K, Lee EY, Yokote K, Accili D, Miki T. Distinct roles of systemic and local actions of insulin on pancreatic β-cells. Metabolism 2018; 82:100-110. [PMID: 29320716 PMCID: PMC7391221 DOI: 10.1016/j.metabol.2017.12.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 12/16/2017] [Accepted: 12/31/2017] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Pancreatic β-cell mass and function are critical in glucose homeostasis. Their regulatory mechanisms have been studied principally under experimental conditions of reduced β-cell numbers, such as β-cell ablation and partial pancreatectomy. In the present study, we generated an opposite mouse model with an excessive amount of ectopic β-cells, and analyzed its consequence on β-cell mass and survival. METHODS Mice underwent sub-renal transplantation (SRT) of pseudo-islets generated from a pancreatic β-cell line MIN6 or intra-pancreatic transplantation (IPT) of MIN6 cells, and morphological and functional changes of their endocrine pancreata were analyzed. Cellular fate of pancreatic β-cells after transplantation was traced using RipCre:Rosa26-tdTomato mice. By using MIN6 cells, we evaluated the roles of extracellular glucose, membrane potential, and insulin signaling on β-cell survival. RESULTS SRT mice developed severe, progressive hypoglycemia associated with marked reduction in insulin-positive (Ins+) cell mass and apparent increase in apoptotic Ins+ cells. In in vitro experiments of MIN6 cells, insulin signaling blockade potently induced cell death, suggesting that local insulin action is required for β-cell survival. In fact, IPT (i.e. transplantation close to endogenous β-cells) resulted in fewer apoptotic Ins+ cells compared with those induced by SRT. On the other hand, β-cell mass was decreased in proportion to the decrease in blood glucose levels in both SRT and IPT mice, suggesting a contribution of hypoglycemia induced by systemic hyperinsulinemia. CONCLUSION Insulin plays distinct roles in β-cell survival and β-cell mass regulation through its local and systemic actions on β-cells, respectively.
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Affiliation(s)
- Takumi Kitamoto
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Department of Clinical Cell Biology and Medicine, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Division of Endocrinology, Department of Medicine, Columbia University, New York 10032, USA
| | - Kenichi Sakurai
- Center for Preventive Medical Sciences, Chiba University, Chiba 263-8522, Japan
| | - Eun Young Lee
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Koutaro Yokote
- Department of Clinical Cell Biology and Medicine, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Domenico Accili
- Division of Endocrinology, Department of Medicine, Columbia University, New York 10032, USA
| | - Takashi Miki
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan.
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16
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Pancreatic Islet Blood Flow Dynamics in Primates. Cell Rep 2018; 20:1490-1501. [PMID: 28793270 PMCID: PMC5575201 DOI: 10.1016/j.celrep.2017.07.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/05/2017] [Accepted: 07/14/2017] [Indexed: 12/26/2022] Open
Abstract
Blood flow regulation in pancreatic islets is critical for function but poorly understood. Here, we establish an in vivo imaging platform in a non-human primate where islets transplanted autologously into the anterior chamber of the eye are monitored non-invasively and longitudinally at single-cell resolution. Engrafted islets were vascularized and innervated and maintained the cytoarchitecture of in situ islets in the pancreas. Blood flow velocity in the engrafted islets was not affected by increasing blood glucose levels and/or the GLP-1R agonist liraglutide. However, islet blood flow was dynamic in nature and fluctuated in various capillaries. This was associated with vasoconstriction events resembling a sphincter-like action, most likely regulated by adrenergic signaling. These observations suggest a mechanism in primate islets that diverts blood flow to cell regions with higher metabolic demand. The described imaging technology applied in non-human primate islets may contribute to a better understanding of human islet pathophysiology. Monkey islets transplanted autologously into the anterior chamber of the eye (ACE) Monkey ACE islets imaged in vivo, longitudinally, and at single-cell resolution Monkey islet blood flow is dynamic and unaffected by glucose/liraglutide treatment Directional blood flow may be explained by islet structure-function relationship
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17
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Zhang Y, Warnock GL, Ao Z, Park YJ, Safikhan N, Ghahary A, Marzban L. Amyloid formation reduces protein kinase B phosphorylation in primary islet β-cells which is improved by blocking IL-1β signaling. PLoS One 2018; 13:e0193184. [PMID: 29474443 PMCID: PMC5825069 DOI: 10.1371/journal.pone.0193184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 02/02/2018] [Indexed: 12/31/2022] Open
Abstract
Amyloid formation in the pancreatic islets due to aggregation of human islet amyloid polypeptide (hIAPP) contributes to reduced β-cell mass and function in type 2 diabetes (T2D) and islet transplantation. Protein kinase B (PKB) signaling plays a key role in the regulation of β-cell survival, function and proliferation. In this study, we used human and hIAPP-expressing transgenic mouse islets in culture as two ex vivo models of human islet amyloid formation to: 1. Investigate the effects of amyloid formation on PKB phosphorylation in primary islet β-cells; 2. Test if inhibition of amyloid formation and/or interleukin-1β (IL-1β) signaling in islets can restore the changes in β-cell phospho-PKB levels mediated by amyloid formation. Human and hIAPP-expressing mouse islets were cultured in elevated glucose with an amyloid inhibitor (Congo red) or embedded within collagen matrix to prevent amyloid formation. To block the IL-1β signaling, human islets were treated with an IL-1 receptor antagonist (anakinra) or a glucagon-like peptide-1 agonist (exenatide). β-cell phospho-PKB levels, proliferation, apoptosis, islet IL-1β levels and amyloid formation were assessed. Amyloid formation in both cultured human and hIAPP-expressing mouse islets reduced β-cell phospho-PKB levels and increased islet IL-1β levels, both of which were restored by prevention of amyloid formation either by the amyloid inhibitor or embedding islets in collagen matrix, resulting in improved β-cell survival. Furthermore, inhibition of IL-1β signaling by treatment with anakinra or exenatide increased β-cell phospho-PKB levels, enhanced proliferation and reduced apoptosis in amyloid forming human islets during 7-day culture. These data suggest that amyloid formation leads to reduced PKB phosphorylation in β-cells which is associated with elevated islet IL-1β levels. Inhibitors of amyloid or amyloid-induced IL-1β production may provide a new approach to restore phospho-PKB levels thereby enhance β-cell survival and proliferation in conditions associated with islet amyloid formation such as T2D and clinical islet transplantation.
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Affiliation(s)
- Yun Zhang
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Garth L. Warnock
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Ziliang Ao
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Yoo Jin Park
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Nooshin Safikhan
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Aziz Ghahary
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Lucy Marzban
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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18
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Rodríguez-Comas J, Moreno-Asso A, Moreno-Vedia J, Martín M, Castaño C, Marzà-Florensa A, Bofill-De Ros X, Mir-Coll J, Montané J, Fillat C, Gasa R, Novials A, Servitja JM. Stress-Induced MicroRNA-708 Impairs β-Cell Function and Growth. Diabetes 2017; 66:3029-3040. [PMID: 28970284 DOI: 10.2337/db16-1569] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 09/24/2017] [Indexed: 11/13/2022]
Abstract
The pancreatic β-cell transcriptome is highly sensitive to external signals such as glucose oscillations and stress cues. MicroRNAs (miRNAs) have emerged as key factors in gene expression regulation. Here, we aimed to identify miRNAs that are modulated by glucose in mouse pancreatic islets. We identified miR-708 as the most upregulated miRNA in islets cultured at low glucose concentrations, a setting that triggers a strong stress response. miR-708 was also potently upregulated by triggering endoplasmic reticulum (ER) stress with thapsigargin and in islets of ob/ob mice. Low-glucose induction of miR-708 was blocked by treatment with the chemical chaperone 4-phenylbutyrate, uncovering the involvement of ER stress in this response. An integrative analysis identified neuronatin (Nnat) as a potential glucose-regulated target of miR-708. Indeed, Nnat expression was inversely correlated with miR-708 in islets cultured at different glucose concentrations and in ob/ob mouse islets and was reduced after miR-708 overexpression. Consistent with the role of Nnat in the secretory function of β-cells, miR-708 overexpression impaired glucose-stimulated insulin secretion (GSIS), which was recovered by NNAT overexpression. Moreover, miR-708 inhibition recovered GSIS in islets cultured at low glucose. Finally, miR-708 overexpression suppressed β-cell proliferation and induced β-cell apoptosis. Collectively, our results provide a novel mechanism of glucose regulation of β-cell function and growth by repressing stress-induced miR-708.
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Affiliation(s)
- Júlia Rodríguez-Comas
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Alba Moreno-Asso
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
| | - Juan Moreno-Vedia
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Mercè Martín
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Carlos Castaño
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
| | - Anna Marzà-Florensa
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Xavier Bofill-De Ros
- Gene Therapy and Cancer Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Joan Mir-Coll
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Department of Medicine, University of Barcelona, Barcelona, Spain
| | - Joel Montané
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
| | - Cristina Fillat
- Gene Therapy and Cancer Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Rosa Gasa
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
| | - Anna Novials
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
| | - Joan-Marc Servitja
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Barcelona, Spain
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19
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Trk-fused gene (TFG) regulates pancreatic β cell mass and insulin secretory activity. Sci Rep 2017; 7:13026. [PMID: 29026155 PMCID: PMC5638802 DOI: 10.1038/s41598-017-13432-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/25/2017] [Indexed: 12/19/2022] Open
Abstract
The Trk-fused gene (TFG) is reportedly involved in the process of COPII-mediated vesicle transport and missense mutations in TFG cause several neurodegenerative diseases including hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P). The high coincidence ratio between HMSN-P and diabetes mellitus suggests TFG to have an important role(s) in glucose homeostasis. To examine this possibility, β-cell specific TFG knockout mice (βTFG KO) were generated. Interestingly, βTFG KO displayed marked glucose intolerance with reduced insulin secretion. Immunohistochemical analysis revealed smaller β-cell masses in βTFG KO than in controls, likely attributable to diminished β-cell proliferation. Consistently, β-cell expansion in response to a high-fat, high-sucrose (HFHS) diet was significantly impaired in βTFG KO. Furthermore, glucose-induced insulin secretion was also markedly impaired in islets isolated from βTFG KO. Electron microscopic observation revealed endoplasmic reticulum (ER) dilatation, suggestive of ER stress, and smaller insulin crystal diameters in β-cells of βTFG KO. Microarray gene expression analysis indicated downregulation of NF-E2 related factor 2 (Nrf2) and its downstream genes in TFG depleted islets. Collectively, TFG in pancreatic β-cells plays a vital role in maintaining both the mass and function of β-cells, and its dysfunction increases the tendency to develop glucose intolerance.
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20
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Montane J, de Pablo S, Castaño C, Rodríguez-Comas J, Cadavez L, Obach M, Visa M, Alcarraz-Vizán G, Sanchez-Martinez M, Nonell-Canals A, Parrizas M, Servitja JM, Novials A. Amyloid-induced β-cell dysfunction and islet inflammation are ameliorated by 4-phenylbutyrate (PBA) treatment. FASEB J 2017; 31:5296-5306. [PMID: 28821639 DOI: 10.1096/fj.201700236r] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/25/2017] [Indexed: 12/28/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) aggregation is associated with β-cell dysfunction and death in type 2 diabetes (T2D). we aimed to determine whether in vivo treatment with chemical chaperone 4-phenylbutyrate (PBA) ameliorates hIAPP-induced β-cell dysfunction and islet amyloid formation. Oral administration of PBA in hIAPP transgenic (hIAPP Tg) mice expressing hIAPP in pancreatic β cells counteracted impaired glucose homeostasis and restored glucose-stimulated insulin secretion. Moreover, PBA treatment almost completely prevented the transcriptomic alterations observed in hIAPP Tg islets, including the induction of genes related to inflammation. PBA also increased β-cell viability and improved insulin secretion in hIAPP Tg islets cultured under glucolipotoxic conditions. Strikingly, PBA not only prevented but even reversed islet amyloid deposition, pointing to a direct effect of PBA on hIAPP. This was supported by in silico calculations uncovering potential binding sites of PBA to monomeric, dimeric, and pentameric fibrillar structures, and by in vitro assays showing inhibition of hIAPP fibril formation by PBA. Collectively, these results uncover a novel beneficial effect of PBA on glucose homeostasis by restoring β-cell function and preventing amyloid formation in mice expressing hIAPP in β cells, highlighting the therapeutic potential of PBA for the treatment of T2D.-Montane, J., de Pablo, S., Castaño, C., Rodríguez-Comas, J., Cadavez, L., Obach, M., Visa, M., Alcarraz-Vizán, G., Sanchez-Martinez, M., Nonell-Canals, A., Parrizas, M., Servitja, J.-M., Novials, A. Amyloid-induced β-cell dysfunction and islet inflammation are ameliorated by 4-phenylbutyrate (PBA) treatment.
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Affiliation(s)
- Joel Montane
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain; .,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Sara de Pablo
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Carlos Castaño
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Júlia Rodríguez-Comas
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Lisa Cadavez
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Mercè Obach
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Montse Visa
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Gema Alcarraz-Vizán
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | | | | | - Marcelina Parrizas
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Joan-Marc Servitja
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Anna Novials
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain; .,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
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Alcarraz-Vizán G, Castaño C, Visa M, Montane J, Servitja JM, Novials A. BACE2 suppression promotes β-cell survival and function in a model of type 2 diabetes induced by human islet amyloid polypeptide overexpression. Cell Mol Life Sci 2017; 74:2827-2838. [PMID: 28337562 PMCID: PMC11107557 DOI: 10.1007/s00018-017-2505-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 02/07/2023]
Abstract
BACE2 (β-site APP-cleaving enzyme 2) is a protease expressed in the brain, but also in the pancreas, where it seems to play a physiological role. Amyloidogenic diseases, including Alzheimer's disease and type 2 diabetes (T2D), share the accumulation of abnormally folded and insoluble proteins that interfere with cell function. In T2D, islet amyloid polypeptide (IAPP) deposits have been shown to be a pathogenic key feature of the disease. The aim of the present study was to investigate the effect of BACE2 modulation on β-cell alterations in a mouse model of T2D induced by IAPP overexpression. Heterozygous mice carrying the human transcript of IAPP (hIAPP-Tg) were used as a model to study the deleterious effects of IAPP upon β-cell function. These animals showed glucose intolerance and impaired insulin secretion. When crossed with BACE2-deficient mice, the animals presented a significant improvement in glucose tolerance accompanied with an enhanced insulin secretion, as compared to hIAPP-Tg mice. BACE2 deficiency also partially reverted gene expression changes observed in islets from hIAPP-Tg mice, including a set of genes related to inflammation. Moreover, homozygous hIAPP mice presented a severe hyperglycemia and a high lethality rate from 8 weeks onwards due to a massive destruction of β-cell mass. This process was significantly reduced when crossed with the BACE2-KO model, improving the survival rate of the animals. Altogether, the absence of BACE2 ameliorates glucose tolerance defects induced by IAPP overexpression in the β-cell and promotes β-cell survival. Thus, targeting BACE2 may represent a promising therapeutic strategy to improve β-cell function in T2D.
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Affiliation(s)
- Gema Alcarraz-Vizán
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain
| | - Carlos Castaño
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain
| | - Montse Visa
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain
| | - Joel Montane
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain
| | - Joan-Marc Servitja
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain.
| | - Anna Novials
- Diabetes and Obesity Research Laboratory, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), C/Rosselló 149-153, 5th floor, 08036, Barcelona, Spain.
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22
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Amylin Receptor: A Potential Therapeutic Target for Alzheimer's Disease. Trends Mol Med 2017; 23:709-720. [PMID: 28694141 DOI: 10.1016/j.molmed.2017.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/08/2017] [Accepted: 06/14/2017] [Indexed: 01/29/2023]
Abstract
Alzheimer'sdisease (AD) is a progressive neurodegenerative disorder, characterized by senile plaques constituting extracellular deposits of β-amyloid (Aβ) fibrils. Since Aβ accumulation in the brain is considered an early event preceding, by decades, cognitive dysfunction, disease-modifying treatments are aimed at facilitating clearance of this protein from the brain or ameliorating its toxic effects. Recent studies have identified the amylin receptor as a capable mediator of the deleterious actions of Aβ and furthermore, administration of amylin receptor-based peptides has been shown to improve spatial memory and learning in transgenic mouse models of AD. Here, by discussing available evidence, we posit that the amylin receptor could be considered a potential therapeutic target for AD, and present the rationale for using amylin receptor antagonists to treat this debilitating condition.
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Shang W, Yang X, Ju X, Xie Y, Zhang Y, Lee WH. Characterization of an insulinotropic peptide from skin secretions of Odorrana andersonii. J Pept Sci 2017; 23:707-715. [DOI: 10.1002/psc.3017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 04/28/2017] [Accepted: 05/16/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Weijie Shang
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences; Kunming 650223 Yunnan China
- Institute of Health Sciences; Anhui University; 111 Jiulong Road 230601 Hefei China
| | - Xinwang Yang
- Department of Anatomy and Histology and Embryology, Faculty of Basic Medical Science; Kunming Medical University; Kunming 650500 China
| | - Xiaoman Ju
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences; Kunming 650223 Yunnan China
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Science; Soochow University; 215123 Suzhou Jiangsu China
| | - Yueying Xie
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences; Kunming 650223 Yunnan China
| | - Yun Zhang
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences; Kunming 650223 Yunnan China
| | - Wen-Hui Lee
- Key Laboratory of Bioactive Peptides of Yunnan Province/Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences; Kunming 650223 Yunnan China
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Wu X, Wang K, Hua W, Li S, Liu X, Liu W, Song Y, Zhang Y, Shao Z, Yang C. Down-regulation of islet amyloid polypeptide expression induces death of human annulus fibrosus cells via mitochondrial and death receptor pathways. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1479-1491. [PMID: 28433710 DOI: 10.1016/j.bbadis.2017.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/10/2017] [Accepted: 04/17/2017] [Indexed: 01/07/2023]
Abstract
Islet amyloid polypeptide (IAPP) exerts its biological effects by participating in the regulation of glucose metabolism and cell apoptosis. The main goal of the present study was to investigate the expression of IAPP in degenerated intervertebral disc tissue and IAPP's modulation of extracellular matrix (ECM) catabolic and anabolic genes in human AF cells. We found that the expression of IAPP, the calcitonin receptor, and receptor activity modifying protein decreased considerably in AF cells during the progression of intervertebral disc degeneration (IDD). Meanwhile, transfection with pLV-siIAPP decreased the expression of IAPP and its receptors and reduced glucose uptake and the expression of aggrecan, Col2A1, and BG. Down-regulation of IAPP also induced a significant increase in reactive oxygen species generation in AF cells, along with a decrease in matrix metalloproteinases and an increase in the concentration of cellular Ca2+, ultimately leading to death. Further analysis revealed that siIAPP intervention promoted the release of cytochrome c from mitochondria, resulting in the activation of Caspase-3 and Caspase-9. In contrast, significantly decreased expression of Caspase-3 and Caspase-9 was observed in AF cells transfected with pLV-IAPP. The concentrations of Fas and FasL proteins were significantly decreased in AF cells transfected with PLV-IAPP, while activation of the Fas/FasL system and cell death were induced by siIAPP intervention. Mechanistically, AMPK/Akt-mTOR signaling pathways were involved. In conclusion, down-regulation of IAPP expression induces the death of human AF cells via mitochondrial and death receptor pathways, potentially offering a novel therapeutic target for the treatment of IDD.
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Affiliation(s)
- Xinghuo Wu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Kun Wang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wenbin Hua
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Shuai Li
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xianzhe Liu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wei Liu
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yu Song
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yukun Zhang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zengwu Shao
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Cao Yang
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
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25
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Bhowmick DC, Singh S, Trikha S, Jeremic AM. The Molecular Physiopathogenesis of Islet Amyloidosis. Handb Exp Pharmacol 2017; 245:271-312. [PMID: 29043504 DOI: 10.1007/164_2017_62] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human islet amyloid polypeptide or amylin (hA) is a 37-amino acid peptide hormone produced and co-secreted with insulin by pancreatic β-cells. Under physiological conditions, hA regulates a broad range of biological processes including insulin release and slowing of gastric emptying, thereby maintaining glucose homeostasis. However, under the pathological conditions associated with type 2 diabetes mellitus (T2DM), hA undergoes a conformational transition from soluble random coil monomers to alpha-helical oligomers and insoluble β-sheet amyloid fibrils or amyloid plaques. There is a positive correlation between hA oligomerization/aggregation, hA toxicity, and diabetes progression. Because the homeostatic balance between hA synthesis, release, and uptake is lost in diabetics and hA aggregation is a hallmark of T2DM, this chapter focuses on the biophysical and cell biology studies investigating molecular mechanisms of hA uptake, trafficking, and degradation in pancreatic cells and its relevance to h's toxicity. We will also discuss the regulatory role of endocytosis and proteolytic pathways in clearance of toxic hA species. Finally, we will discuss potential pharmacological approaches for specific targeting of hA trafficking pathways and toxicity in islet β-cells as potential new avenues toward treatments of T2DM patients.
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Affiliation(s)
| | - Sanghamitra Singh
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Saurabh Trikha
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Aleksandar M Jeremic
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA.
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26
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Hay DL, Chen S, Lutz TA, Parkes DG, Roth JD. Amylin: Pharmacology, Physiology, and Clinical Potential. Pharmacol Rev 2016; 67:564-600. [PMID: 26071095 DOI: 10.1124/pr.115.010629] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amylin is a pancreatic β-cell hormone that produces effects in several different organ systems. Here, we review the literature in rodents and in humans on amylin research since its discovery as a hormone about 25 years ago. Amylin is a 37-amino-acid peptide that activates its specific receptors, which are multisubunit G protein-coupled receptors resulting from the coexpression of a core receptor protein with receptor activity-modifying proteins, resulting in multiple receptor subtypes. Amylin's major role is as a glucoregulatory hormone, and it is an important regulator of energy metabolism in health and disease. Other amylin actions have also been reported, such as on the cardiovascular system or on bone. Amylin acts principally in the circumventricular organs of the central nervous system and functionally interacts with other metabolically active hormones such as cholecystokinin, leptin, and estradiol. The amylin-based peptide, pramlintide, is used clinically to treat type 1 and type 2 diabetes. Clinical studies in obesity have shown that amylin agonists could also be useful for weight loss, especially in combination with other agents.
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Affiliation(s)
- Debbie L Hay
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Steve Chen
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Thomas A Lutz
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - David G Parkes
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Jonathan D Roth
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
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