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Lafferty RA, Flatt PR, Irwin N. NPYR modulation: Potential for the next major advance in obesity and type 2 diabetes management? Peptides 2024:171256. [PMID: 38825012 DOI: 10.1016/j.peptides.2024.171256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/13/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
The approval of the glucagon-like peptide 1 (GLP-1) mimetics semaglutide and liraglutide for management of obesity, independent of type 2 diabetes (T2DM), has initiated a resurgence of interest in gut-hormone derived peptide therapies for the management of metabolic diseases, but side-effect profile is a concern for these medicines. However, the recent approval of tirzepatide for obesity and T2DM, a glucose-dependent insulinotropic polypeptide (GIP), GLP-1 receptor co-agonist peptide therapy, may provide a somewhat more tolerable option. Despite this, an increasing number of non-incretin alternative peptides are in development for obesity, and it stands to reason that other hormones will take to the limelight in the coming years, such as peptides from the neuropeptide Y family. This narrative review outlines the therapeutic promise of the neuropeptide Y family of peptides, comprising of the 36 amino acid polypeptides neuropeptide Y (NPY), peptide tyrosine-tyrosine (PYY) and pancreatic polypeptide (PP), as well as their derivatives. This family of peptides exerts a number of metabolically relevant effects such as appetite regulation and can influence pancreatic beta-cell survival. Although some of these actions still require full translation to the human setting, potential therapeutic application in obesity and type 2 diabetes is conceivable. However, like GLP-1 and GIP, the endogenous NPY, PYY and PP peptide forms are subject to rapid in vivo degradation and inactivation by the serine peptidase, dipeptidyl-peptidase 4 (DPP-4), and hence require structural modification to prolong circulating half-life. Numerous protective modification strategies are discussed in this regard herein, alongside related impact on biological activity profile and therapeutic promise.
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Affiliation(s)
- Ryan A Lafferty
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK.
| | - Peter R Flatt
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK
| | - Nigel Irwin
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, BT52 1SA, UK
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2
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Ehsasatvatan M, Baghban Kohnehrouz B. Designing and computational analyzing of chimeric long-lasting GLP-1 receptor agonists for type 2 diabetes. Sci Rep 2023; 13:17778. [PMID: 37853095 PMCID: PMC10584922 DOI: 10.1038/s41598-023-45185-1] [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: 06/19/2023] [Accepted: 10/17/2023] [Indexed: 10/20/2023] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is an intestinally derived incretin that plays a vital role in engineering the biological circuit involved in treating type 2 diabetes. Exceedingly short half-life (1-2 min) of GLP-1 limits its therapeutic applicability, and the implication of its new variants is under question. Since albumin-binding DARPin as a mimetic molecule has been reported to increase the serum half-life of therapeutic compounds, the interaction of new variants of GLP-1 in fusion with DARPin needs to be examined against the GLP-1 receptor. This study was aimed to design stable and functional fusion proteins consisting of new protease-resistant GLP-1 mutants (mGLP1) genetically fused to DARPin as a critical step toward developing long-acting GLP-1 receptor agonists. The stability and solubility of the engineered fusion proteins were analyzed, and their secondary and tertiary structures were predicted and satisfactorily validated. Molecular dynamics simulation studies revealed that the predicted structures of engineered fusion proteins remained stable throughout the simulation. The relative binding affinity of the engineered fusion proteins' complex with human serum albumin and the GLP-1 receptor individually was assessed using molecular docking analyses. It revealed a higher affinity compared to the interaction of the individual GLP-1 and HSA-binding DARPin with the GLP-1 receptor and human serum albumin, respectively. The present study suggests that engineered fusion proteins can be used as a potential molecule in the treatment of type 2 diabetes, and this study provides insight into further experimental use of mimetic complexes as alternative molecules to be evaluated as new bio-breaks in the engineering of biological circuits in the treatment of type 2 diabetes.
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Affiliation(s)
- Maryam Ehsasatvatan
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, 51666, Iran
| | - Bahram Baghban Kohnehrouz
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, 51666, Iran.
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3
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Coulter-Parkhill A, Gault VA, McClean S, Irwin N. Peptides originally derived from Chilobrachys jingzhao tarantula venom possess beneficial effects on pancreatic beta cell health and function. Eur J Pharmacol 2023:175855. [PMID: 37391009 DOI: 10.1016/j.ejphar.2023.175855] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023]
Abstract
Clinical approval of the glucagon-like peptide-1 (GLP-1) mimetic exenatide for the treatment of type 2 diabetes highlights the therapeutic effectiveness of venom-derived peptides. In the present study, we examined and characterised the glucose-lowering potential of synthetic Jingzhaotoxin IX and Jingzhaotoxin XI peptides, which were originally isolated from the venom of the Chinese earth tarantula Chilobrachys jingzhao. Following confirmation of lack of beta-cell toxicity of synthetic peptides, assessment of enzymatic stability and effects on in vitro beta-cell function were studied, alongside putative mechanisms. Glucose homeostatic and appetite suppressive actions of Jingzhaotoxin IX and Jingzhaotoxin XI alone, or in combination with exenatide, were then assessed in normal overnight fasted C57BL/6 mice. Synthetic Jingzhaotoxin peptides were non-toxic and exhibited a decrease in mass of 6 Da in Krebs-Ringer bicarbonate buffer suggesting inhibitor cysteine knot (ICK)-like formation, but interestingly were liable to plasma enzyme degradation. The Jingzhaotoxin peptides evoked prominent insulin secretion from BRIN BD11 beta-cells, with activity somewhat characteristic of Kv2.1 channel binding. In addition, Jingzhaotoxin peptides enhanced beta-cell proliferation and provided significant protection against cytokine-induced apoptosis. When injected co-jointly with glucose, the Jingzhaotoxin peptides slightly decreased blood-glucose levels but had no effect on appetite in overnight fasted mice. Whilst the Jingzhaotoxin peptides did not enhance exenatide-induced benefits on glucose homeostasis, they augmented exenatide-mediated suppression of appetite. Taken together, these data highlight the therapeutic potential of tarantula venom-derived peptides, such as Jingzhaotoxin IX and Jingzhaotoxin XI either alone or in combination with exenatide, for diabetes and related obesity.
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Affiliation(s)
- A Coulter-Parkhill
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, UK
| | - V A Gault
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, UK
| | - S McClean
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, UK
| | - N Irwin
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland, UK.
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Lafferty RA, Flatt PR, Irwin N. Established and emerging roles peptide YY (PYY) and exploitation in obesity-diabetes. Curr Opin Endocrinol Diabetes Obes 2021; 28:253-261. [PMID: 33395088 DOI: 10.1097/med.0000000000000612] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW The antiobesity effects of activation of hypothalamic neuropeptide Y2 receptors (NPYR2) by the gut-derived hormone, peptide YY (PYY), are established. However, more recent insight into the biology of PYY has demonstrated remarkable benefits of sustained activation of pancreatic beta-cell NPYR1, that promises to open a new therapeutic avenue in diabetes. RECENT FINDINGS The therapeutic applicability of NPYR2 agonists for obesity has been considered for many years. An alternative pathway for the clinical realisation of PYY-based drugs could be related to the development of NPYR1 agonists for treatment of diabetes. Thus, although stimulation of NPYR1 on pancreatic beta-cells has immediate insulinostatic effects, prolonged activation of these receptors leads to well defined beta-cell protective effects, with obvious positive implications for the treatment of diabetes. In this regard, NPYR1-specific, long-acting enzyme resistant PYY analogues, have been recently developed with encouraging preclinical effects observed on pancreatic islet architecture in diabetes. In agreement, the benefits of certain types of bariatric surgeries on beta-cell function and responsiveness have also been linked to elevated PYY secretion and NPY1 receptor activation. SUMMARY Enzymatically stable forms of PYY, that selectively activate NPYR1, may have significant potential for preservation of beta-cell mass and the treatment of diabetes.
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Affiliation(s)
- Ryan A Lafferty
- Diabetes Research Group, Ulster University, Coleraine, Northern Ireland, UK
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van der Velden WJC, Smit FX, Christiansen CB, Møller TC, Hjortø GM, Larsen O, Schiellerup SP, Bräuner-Osborne H, Holst JJ, Hartmann B, Frimurer TM, Rosenkilde MM. GLP-1 Val8: A Biased GLP-1R Agonist with Altered Binding Kinetics and Impaired Release of Pancreatic Hormones in Rats. ACS Pharmacol Transl Sci 2021; 4:296-313. [PMID: 33615180 DOI: 10.1021/acsptsci.0c00193] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Indexed: 02/08/2023]
Abstract
Biased ligands that selectively confer activity in one pathway over another are pharmacologically important because biased signaling may reduce on-target side effects and improve drug efficacy. Here, we describe an N-terminal modification in the incretin hormone glucagon-like peptide (GLP-1) that alters the signaling capabilities of the GLP-1 receptor (GLP-1R) by making it G protein biased over internalization but was originally designed to confer DPP-4 resistance and thereby prolong the half-life of GLP-1. Despite similar binding affinity, cAMP production, and calcium mobilization, substitution of a single amino acid (Ala8 to Val8) in the N-terminus of GLP-1(7-36)NH2 (GLP-1 Val8) severely impaired its ability to internalize GLP-1R compared to endogenous GLP-1. In-depth binding kinetics analyses revealed shorter residence time for GLP-1 Val8 as well as a slower observed association rate. Molecular dynamics (MD) displayed weaker and less interactions of GLP-1 Val8 with GLP-1R, as well as distinct conformational changes in the receptor compared to GLP-1. In vitro validation of the MD, by receptor alanine substitutions, confirmed stronger impairments of GLP-1 Val8-mediated signaling compared to GLP-1. In a perfused rat pancreas, acute stimulation with GLP-1 Val8 resulted in a lower insulin and somatostatin secretion compared to GLP-1. Our study illustrates that profound differences in molecular pharmacological properties, which are essential for the therapeutic targeting of the GLP-1 system, can be induced by subtle changes in the N-terminus of GLP-1. This information could facilitate the development of optimized GLP-1R agonists.
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Affiliation(s)
- Wijnand J C van der Velden
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Florent X Smit
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Charlotte B Christiansen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences University of Copenhagen, Copenhagen 2200, Denmark
| | - Thor C Møller
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Gertrud M Hjortø
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Olav Larsen
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sine P Schiellerup
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences University of Copenhagen, Copenhagen 2200, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences University of Copenhagen, Copenhagen 2200, Denmark
| | - Thomas M Frimurer
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
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6
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Tanday N, English A, Lafferty RA, Flatt PR, Irwin N. Benefits of Sustained Upregulated Unimolecular GLP-1 and CCK Receptor Signalling in Obesity-Diabetes. Front Endocrinol (Lausanne) 2021; 12:674704. [PMID: 34054734 PMCID: PMC8160446 DOI: 10.3389/fendo.2021.674704] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
Combined activation of GLP-1 and CCK1 receptors has potential to synergistically augment the appetite-suppressive and glucose homeostatic actions of the individual parent peptides. In the current study, pancreatic beta-cell benefits of combined GLP-1 and CCK1 receptor upregulation were established, before characterising bioactivity and antidiabetic efficacy of an acylated dual-acting GLP-1/CCK hybrid peptide, namely [Lys12Pal]Ex-4/CCK. Both exendin-4 and CCK exhibited (p<0.001) proliferative and anti-apoptotic effects in BRIN BD11 beta-cells. Proliferative benefits were significantly (p<0.01) augmented by combined peptide treatment when compared to either parent peptide alone. These effects were linked to increases (p<0.001) in GLUT2 and glucokinase beta-cell gene expression, with decreased (p<0.05-p<0.001) expression of NFκB and BAX. [Lys12Pal]Ex-4/CCK exhibited prominent insulinotropic actions in vitro, coupled with beneficial (p<0.001) satiety and glucose homeostatic effects in the mice, with bioactivity evident 24 h after administration. Following twice daily injection of [Lys12Pal]Ex-4/CCK for 28 days in diabetic high fat fed (HFF) mice with streptozotocin (STZ)-induced compromised beta-cells, there were clear reductions (p<0.05-p<0.001) in energy intake and body weight. Circulating glucose was returned to lean control concentrations, with associated increases (p<0.001) in plasma and pancreatic insulin levels. Glucose tolerance and insulin secretory responsiveness were significantly (p<0.05-p<0.001) improved by hybrid peptide therapy. In keeping with this, evaluation of pancreatic histology revealed restoration of normal islet alpha- to beta-cell ratios and reduction (p<0.01) in centralised islet glucagon staining. Improvements in pancreatic islet morphology were associated with increased (p<0.05) proliferation and reduced (p<0.001) apoptosis of beta-cells. Together, these data highlight the effectiveness of sustained dual GLP-1 and CCK1 receptor activation by [Lys12Pal]Ex-4/CCK for the treatment of obesity-related diabetes.
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MESH Headings
- Animals
- Biomarkers/blood
- Blood Glucose/analysis
- Body Weight
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Diet, High-Fat
- Exenatide/pharmacology
- Glucagon-Like Peptide 1/genetics
- Glucagon-Like Peptide 1/metabolism
- Hypoglycemic Agents/pharmacology
- Insulin Secretion
- Insulin-Secreting Cells/drug effects
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Obesity/physiopathology
- Peptide Fragments/pharmacology
- Receptors, Cholecystokinin/genetics
- Receptors, Cholecystokinin/metabolism
- Up-Regulation
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Yousefpour P, Varanko A, Subrahmanyan R, Chilkoti A. Recombinant Fusion of Glucagon‐Like Peptide‐1 and an Albumin Binding Domain Provides Glycemic Control for a Week in Diabetic Mice. ADVANCED THERAPEUTICS 2020. [DOI: 10.1002/adtp.202000073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Parisa Yousefpour
- Department of Biomedical Engineering Duke University Durham NC 27708 USA
| | - Anastasia Varanko
- Department of Biomedical Engineering Duke University Durham NC 27708 USA
| | | | - Ashutosh Chilkoti
- Department of Biomedical Engineering Duke University Durham NC 27708 USA
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8
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Lafferty RA, Tanday N, McCloskey A, Bompada P, De Marinis Y, Flatt PR, Irwin N. Peptide YY (1-36) peptides from phylogenetically ancient fish targeting mammalian neuropeptide Y1 receptors demonstrate potent effects on pancreatic β-cell function, growth and survival. Diabetes Obes Metab 2020; 22:404-416. [PMID: 31692207 DOI: 10.1111/dom.13908] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/31/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023]
Abstract
AIM To investigate the antidiabetic efficacy of enzymatically stable Peptide YY (PYY) peptides from phylogenetically ancient fish. MATERIALS AND METHODS N-terminally stabilized, PYY (1-36) sequences from Amia calva (bowfin), Oncorhynchus mykiss (trout), Petromyzon marinus (sea lamprey) and Scaphirhynchus albus (sturgeon), were synthesized, and both biological actions and antidiabetic therapeutic efficacy were assessed. RESULTS All fish PYY (1-36) peptides were resistant to dipeptidyl peptidase-4 (DPP-4) degradation and inhibited glucose- and alanine-induced (P < 0.05 to P < 0.001) insulin secretion. In addition, PYY (1-36) peptides imparted significant (P < 0.05 to P < 0.001) β-cell proliferative and anti-apoptotic benefits. Proliferative effects were almost entirely absent in β cells with CRISPR-Cas9-induced knockout of Npyr1. In contrast to human PYY (1-36), the piscine-derived peptides lacked appetite-suppressive actions. Twice-daily administration of sea lamprey PYY (1-36), the superior bioactive peptide, for 21 days significantly (P < 0.05 to P < 0.001) decreased fluid intake, non-fasting glucose and glucagon in streptozotocin (STZ)-induced diabetic mice. In addition, glucose tolerance, insulin sensitivity, pancreatic insulin and glucagon content were significantly improved. Metabolic benefits were linked to positive changes in pancreatic islet morphology as a result of augmented (P < 0.001) proliferation and decreased apoptosis of β cells. Sturgeon PYY (1-36) exerted similar but less impressive effects in STZ mice. CONCLUSION These observations reveal, for the first time, that PYY (1-36) peptide sequences from phylogenetically ancient fish replicate the pancreatic β-cell benefits of human PYY (1-36) and have clear potential for the treatment of type 2 diabetes.
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Affiliation(s)
- Ryan A Lafferty
- SAAD Centre for Pharmacy and Diabetes, Biomedical Sciences Research Institute, University of Ulster, Coleraine, UK
| | - Neil Tanday
- SAAD Centre for Pharmacy and Diabetes, Biomedical Sciences Research Institute, University of Ulster, Coleraine, UK
| | - Andrew McCloskey
- SAAD Centre for Pharmacy and Diabetes, Biomedical Sciences Research Institute, University of Ulster, Coleraine, UK
| | - Pradeep Bompada
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Yang De Marinis
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Biomedical Sciences Research Institute, University of Ulster, Coleraine, UK
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Biomedical Sciences Research Institute, University of Ulster, Coleraine, UK
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9
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10
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Kuipers A, de Vries L, de Vries MP, Rink R, Bosma T, Moll GN. Semi-microbiological synthesis of an active lysinoalanine-bridged analog of glucagon-like-peptide-1. Peptides 2017; 91:33-39. [PMID: 28300673 DOI: 10.1016/j.peptides.2017.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 03/03/2017] [Accepted: 03/07/2017] [Indexed: 10/20/2022]
Abstract
Some modified glucagon-like-peptide-1 (GLP-1) analogs are highly important for treating type 2 diabetes. Here we investigated whether GLP-1 analogs expressed in Lactococcus lactis could be substrates for modification and export by the nisin dehydratase and transporter enzyme. Subsequently we introduced a lysinoalanine by coupling a formed dehydroalanine with a lysine and investigated the structure and activity of the formed lysinoalanine-bridged GLP-1 analog. Our data show: (i) GLP-1 fused to the nisin leader peptide is very well exported via the nisin transporter NisT, (ii) production of leader-GLP-1 via NisT is higher than via the SEC system, (iii) leader-GLP-1 exported via NisT was more efficiently dehydrated by the nisin dehydratase NisB than when exported via the SEC system, (iv) individual serines and threonines in GLP-1 are dehydrated by NisB to a significantly different extent, (v) an introduced Ser30 is well dehydrated and can be coupled to Lys34 to form a lysinoalanine-bridged GLP-1 analog, (vi) a lysinoalanine(30-34) variant's conformation shifts in the presence of 25% trifluoroethanol towards a higher alpha helix content than observed for wild type GLP-1 under identical condition, (vii) a lysinoalanine(30-34) GLP-1 variant has retained significant activity. Taken together the data extend knowledge on the substrate specificities of NisT and NisB and their combined activity relative to export via the Sec system, and demonstrate that introducing a lysinoalanine bridge is an option for modifying therapeutic peptides.
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Affiliation(s)
- Anneke Kuipers
- Lanthio Pharma, a MorphoSys AG company, 9727 DL Groningen, The Netherlands
| | - Louwe de Vries
- Lanthio Pharma, a MorphoSys AG company, 9727 DL Groningen, The Netherlands
| | - Marcel P de Vries
- Mass Spectrometry Core Facility, Department of Pharmacy, University of Groningen, 9713 AV Groningen, The Netherlands; Department of Pediatrics, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
| | - Rick Rink
- Lanthio Pharma, a MorphoSys AG company, 9727 DL Groningen, The Netherlands
| | - Tjibbe Bosma
- Lanthio Pharma, a MorphoSys AG company, 9727 DL Groningen, The Netherlands
| | - Gert N Moll
- Lanthio Pharma, a MorphoSys AG company, 9727 DL Groningen, The Netherlands; Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands.
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11
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A new GLP-1 analogue with prolonged glucose-lowering activity in vivo via backbone-based modification at the N-terminus. Bioorg Med Chem 2016; 24:1163-70. [PMID: 26895657 DOI: 10.1016/j.bmc.2016.01.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/18/2016] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is an endogenous insulinotropic hormone with wonderful glucose-lowering activity. However, its clinical use in type II diabetes is limited due to its rapid degradation at the N-terminus by dipeptidyl peptidase IV (DPP-IV). Among the N-terminal modifications of GLP-1, backbone-based modification was rarely reported. Herein, we employed two backbone-based strategies to modify the N-terminus of tGLP-1. Firstly, the amide N-methylated analogues 2-6 were designed and synthesized to make a full screening of the N-terminal amide bonds, and the loss of GLP-1 receptor (GLP-1R) activation indicated the importance of amide H-bonds. Secondly, with retaining the N-terminal amide H-bonds, the β-peptide replacement strategy was used and analogues 7-13 were synthesized. By two rounds of screening, analogue 10 was identified. Analogue 10 greatly improved the DPP-IV resistance with maintaining good GLP-1R activation in vitro, and showed approximately a 4-fold prolonged blood glucose-lowering activity in vivo in comparison with tGLP-1. This modification strategy will benefit the development of GLP-1-based anti-diabetic drugs.
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12
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Tasyurek HM, Altunbas HA, Balci MK, Sanlioglu S. Incretins: their physiology and application in the treatment of diabetes mellitus. Diabetes Metab Res Rev 2014; 30:354-71. [PMID: 24989141 DOI: 10.1002/dmrr.2501] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/06/2013] [Accepted: 11/12/2013] [Indexed: 12/18/2022]
Abstract
Therapies targeting the action of incretin hormones have been under close scrutiny in recent years. The incretin effect has been defined as postprandial enhancement of insulin secretion by gut-derived factors. Likewise, incretin mimetics and incretin effect amplifiers are the two different incretin-based treatment strategies developed for the treatment of diabetes. Although, incretin mimetics produce effects very similar to those of natural incretin hormones, incretin effect amplifiers act by inhibiting dipeptidyl peptidase-4 (DPP-4) enzyme to increase plasma concentration of incretins and their biologic effects. Because glucagon-like peptide-1 (GLP-1) is an incretin hormone with various anti-diabetic actions including stimulation of glucose-induced insulin secretion, inhibition of glucagon secretion, hepatic glucose production and gastric emptying, it has been evaluated as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM). GLP-1 also manifests trophic effects on pancreas such as pancreatic beta cell growth and differentiation. Because DPP-4 is the enzyme responsible for the inactivation of GLP-1, DPP-4 inhibition represents another potential strategy to increase plasma concentration of GLP-1 to enhance the incretin effect. Thus, anti-diabetic properties of these two classes of drugs have stimulated substantial clinical interest in the potential of incretin-based therapeutic agents as a means to control glucose homeostasis in T2DM patients. Despite this fact, clinical use of GLP-1 mimetics and DPP-4 inhibitors have raised substantial concerns owing to possible side effects of the treatments involving increased risk for pancreatitis, and C-cell adenoma/carcinoma. Thus, controversial issues in incretin-based therapies under development are reviewed and discussed in this manuscript.
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13
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Hewage CM, Venneti KC. Structural aspects of gut peptides with therapeutic potential for type 2 diabetes. ChemMedChem 2013; 8:560-7. [PMID: 23292985 DOI: 10.1002/cmdc.201200445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Indexed: 12/25/2022]
Abstract
Gut hormones represent a niche subset of pharmacologically active agents that are rapidly gaining importance in medicine. Due to their exceptional specificity for their receptors, these hormones along with their analogues have attracted considerable pharmaceutical interest for the treatment of human disorders including type 2 diabetes. With the recent advances in the structural biology, a significant amount of structural information for these hormones is now available. This Minireview presents an overview of the structural aspects of these hormones, which have roles in physiological processes such as insulin secretion, as well as a discussion on the relevant structural modifications used to improve these hormones for the treatment of type 2 diabetes.
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Affiliation(s)
- Chandralal M Hewage
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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Selis F, Schrepfer R, Sanna R, Scaramuzza S, Tonon G, Dedoni S, Onali P, Orsini G, Genovese S. Enzymatic mono-pegylation of glucagon-like peptide 1 towards long lasting treatment of type 2 diabetes. RESULTS IN PHARMA SCIENCES 2012; 2:58-65. [PMID: 25755995 PMCID: PMC4167179 DOI: 10.1016/j.rinphs.2012.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/03/2012] [Accepted: 09/05/2012] [Indexed: 11/30/2022]
Abstract
Human glucagon-like peptide-1 (GLP-1) is a physiological gastrointestinal peptide with glucose-dependent insulinotropic effects which is therefore considered an interesting antidiabetic agent. However, after in vivo administration, exogenous GLP-1 does not exert its physiological action due to the combination of rapid proteolytic degradation by ubiquitous dipeptidyldipeptidase IV (DPP IV) enzyme and renal clearance resulting in an extremely short circulating half-life. In this work we describe the conjugation of GLP-1-(7-36)-amide derivatives with polyethylene glycol (PEG) by enzymatic site-specific transglutamination reaction as an approach to reduce both the proteolysis and the renal clearance rates. The compound GLP-1-(7-36)-amide-Q23-PEG 20 kDa monopegylated on the single glutamine residue naturally present in position 23 maintained the ability to activate the GLP-1 receptor expressed in the rat β-cell line RIN-m5F with nanomolar potency along with an increased in vitro resistance to DDP IV and a circulating half-life of about 12 h after subcutaneous administration in rats. These properties enabled GLP-(7-36)-amide-Q23-PEG 20 kDa to exert a glucose-stabilizing effect for a period as long as 8 h, as demonstrated by a single subcutaneous injection to diabetic mice concomitantly challenged with an oral glucose load. The results reported in this work indicate that GLP-(7-36)-amide-Q23-PEG 20 kDa could be a lead compound for the development of long-lasting anti-diabetic agents useful in the treatment of type 2 diabetes affected patients.
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Affiliation(s)
- Fabio Selis
- Bioker srl-Multimedica Group, c/o CNR-IGB, via P. Castellino 111, 80131 Naples, Italy
| | - Rodolfo Schrepfer
- Bioker srl-Multimedica Group, c/o Sardinia Scientific and Technological Park, Building 3, I-09010 Pula (Cagliari), Italy
| | - Riccardo Sanna
- Bioker srl-Multimedica Group, c/o Department of Neuroscience, via Pansini 5, 80131 Naples, Italy
| | - Silvia Scaramuzza
- Bioker srl-Multimedica Group, c/o CNR-IGB, via P. Castellino 111, 80131 Naples, Italy
| | - Giancarlo Tonon
- Bioker srl-Multimedica Group, c/o Sardinia Scientific and Technological Park, Building 3, I-09010 Pula (Cagliari), Italy
| | - Simona Dedoni
- Section of Biochemical Pharmacology, Department of Neuroscience, University of Cagliari, 09042 Monserrato (Cagliari), Italy
| | - Pierluigi Onali
- Section of Biochemical Pharmacology, Department of Neuroscience, University of Cagliari, 09042 Monserrato (Cagliari), Italy
| | - Gaetano Orsini
- Bioker srl-Multimedica Group, c/o Sardinia Scientific and Technological Park, Building 3, I-09010 Pula (Cagliari), Italy
| | - Stefano Genovese
- Diabetes and Metabolic Diseases Unit, IRCCS Multimedica, Sesto San Giovanni (Milano), Italy
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15
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Choi SH, Lee HC. Long-term, antidiabetogenic effects of GLP-1 gene therapy using a double-stranded, adeno-associated viral vector. Gene Ther 2010; 18:155-63. [DOI: 10.1038/gt.2010.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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16
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Abstract
Type 2 diabetes has been identified as a risk factor for Alzheimer's disease (AD). The underlying mechanism behind this unexpected link is most likely linked to the observed desensitization of insulin receptors in the brain. Insulin acts as a growth factor in the brain and supports neuronal repair, dendritic sprouting, and differentiation. Several drugs have been developed to treat type 2 diabetes which re-synthesize insulin receptors and may be of use to prevent neurodegenerative developments in AD. The incretin glucagon-like peptide-1 (GLP-1) is a hormone that facilitates insulin release under high blood sugar conditions. Interestingly, GLP-1 also has very similar growth factor like properties as insulin, and has been shown to protect neurons from toxic effects. In preclinical studies, GLP-1 and longer lasting analogues reduce apoptosis, protect neurons from oxidative stress, induce neurite outgrowth, protect synaptic plasticity and memory formation from the detrimental effects of β-amyloid, and reduce plaque formation and the inflammation response in the brains of mouse models of AD. An advantage of GLP-1 is that it does not affect blood sugar levels in nondiabetic people. Furthermore, recent research has shown that some GLP-1 analogues can cross the blood-brain barrier, including two that are on the market as a treatment for type 2 diabetes. Therefore, GLP-1 analogues show great promise as a novel treatment for AD or other neurodegenerative conditions.
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17
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Ueda T, Tomita K, Notsu Y, Ito T, Fumoto M, Takakura T, Nagatome H, Takimoto A, Mihara SI, Togame H, Kawamoto K, Iwasaki T, Asakura K, Oshima T, Hanasaki K, Nishimura SI, Kondo H. Chemoenzymatic synthesis of glycosylated glucagon-like peptide 1: effect of glycosylation on proteolytic resistance and in vivo blood glucose-lowering activity. J Am Chem Soc 2009; 131:6237-45. [PMID: 19361194 DOI: 10.1021/ja900261g] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glucagon-like peptide 1 (7-36) amide (GLP-1) has been attracting considerable attention as a therapeutic agent for the treatment of type 2 diabetes. In this study, we applied a glycoengineering strategy to GLP-1 to improve its proteolytic stability and in vivo blood glucose-lowering activity. Glycosylated analogues with N-acetylglucosamine (GlcNAc), N-acetyllactosamine (LacNAc), and alpha2,6-sialyl N-acetyllactosamine (sialyl LacNAc) were prepared by chemoenzymatic approaches. We assessed the receptor binding affinity and cAMP production activity in vitro, the proteolytic resistance against dipeptidyl peptidase-IV (DPP-IV) and neutral endopeptidase (NEP) 24.11, and the blood glucose-lowering activity in diabetic db/db mice. Addition of sialyl LacNAc to GLP-1 greatly improved stability against DPP-IV and NEP 24.11 as compared to the native type. Also, the sialyl LacNAc moiety extended the blood glucose-lowering activity in vivo. Kinetic analysis of the degradation reactions suggested that the sialic acid component played an important role in decreasing the affinity of peptide to DPP-IV. In addition, the stability of GLP-1 against both DPP-IV and NEP24.11 incrementally improved with an increase in the content of sialyl LacNAc in the peptide. The di- and triglycosylated analogues with sialyl LacNAc showed greatly prolonged blood glucose-lowering activity of up to 5 h after administration (100 nmol/kg), although native GLP-1 showed only a brief duration. This study is the first attempt to thoroughly examine the effect of glycosylation on proteolytic resistance by using synthetic glycopeptides having homogeneous glycoforms. This information should be useful for the design of glycosylated analogues of other bioactive peptides as desirable pharmaceuticals.
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Affiliation(s)
- Taichi Ueda
- Discovery Research Laboratories, Settsu Plant, and Pharmaceutical Research Division, Shionogi & Co., Ltd., Toyonaka, Osaka 561-0825, Japan
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18
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Meng H, Krishnaji ST, Beinborn M, Kumar K. Influence of selective fluorination on the biological activity and proteolytic stability of glucagon-like peptide-1. J Med Chem 2008; 51:7303-7. [PMID: 18950150 PMCID: PMC2645917 DOI: 10.1021/jm8008579] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The relative simplicity and high specificity of peptide therapeutics has fueled recent interest. However, peptide and protein drugs generally require injection and suffer from low metabolic stability. We report here the design, synthesis, and characterization of fluorinated analogues of the gut hormone peptide, GLP-1. Overall, fluorinated GLP-1 analogues displayed higher proteolytic stability with simultaneous retention of biological activity (efficacy). Fluorinated amino acids are useful for engineering peptide drug candidates and probing ligand-receptor interactions.
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Affiliation(s)
- He Meng
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155
| | | | - Martin Beinborn
- Molecular Pharmacology Research Center, Tufts Medical Center, Boston, Massachusetts 02111
| | - Krishna Kumar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155
- Cancer Center, Tufts Medical Center, Boston, Massachusetts 02110
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19
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New roles for insulin-like hormones in neuronal signalling and protection: new hopes for novel treatments of Alzheimer's disease? Neurobiol Aging 2008; 31:1495-502. [PMID: 18930564 DOI: 10.1016/j.neurobiolaging.2008.08.023] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/21/2008] [Accepted: 08/30/2008] [Indexed: 01/06/2023]
Abstract
Type 2 diabetes has been identified as a risk factor for Alzheimer's disease (AD). This is most likely due to the desensitisation of insulin receptors in the brain. Insulin acts as a growth factor and supports neuronal repair, dendritic sprouting, and differentiation. This review discusses the potential role that insulin-like hormones could play in ameliorating the reduced growth factor signalling in the brains of people with AD. The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) have very similar properties in protecting neurons from toxic effects, and are capable of reversing the detrimental effects that beta-amyloid fragments have on synaptic plasticity. Therefore, incretins show great promise as a novel treatment for reducing degenerative processes in AD.
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20
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Irwin N, McClean PL, Flatt PR. Comparison of the subchronic antidiabetic effects of DPP IV–resistant GIP and GLP-1 analogues in obese diabetic (ob/ob) mice. J Pept Sci 2007; 13:400-5. [PMID: 17486662 DOI: 10.1002/psc.861] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are the two key incretin hormones released from the gastrointestinal tract that regulate blood glucose homeostasis through potent insulin secretion. The rapid degradation of GIP and GLP-1 by the ubiquitous enzyme dipeptidyl peptidase IV (DPP IV) renders both peptides noninsulinotropic. However, DPP IV stable agonists, such as N-AcGIP and (Val8)GLP-1, have now been developed. The present study has examined and compared the metabolic effects of subchronic administration of daily i.p. injections of N-AcGIP, (Val8) GLP-1 and a combination of both peptides (all at 25 nmol/kg bw) in obese diabetic (ob/ob) mice. Initial in vitro experiments confirmed the potent insulinotropic properties of N-AcGIP and (Val8)GLP-1 in the clonal pancreatic BRIN BD11 cell line. Subchronic administration of N-AcGIP, (Val8)GLP-1 or combined peptide administration had no significant effects on the body weight, food intake and plasma insulin concentrations. However, all treatment groups had significantly (p < 0.05) decreased plasma glucose levels and improved glucose tolerance by day 14. The effectiveness of the peptide groups was similar, and glucose concentrations were substantially reduced following injection of insulin to assess insulin sensitivity compared to control. These results provide evidence for an improvement of glucose homeostasis following treatment with enzyme-resistant GIP and GLP-1 analogues.
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Affiliation(s)
- Nigel Irwin
- School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK.
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21
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Beneficial effects of sub-chronic activation of glucagon-like peptide-1 (GLP-1) receptors on deterioration of glucose homeostasis and insulin secretion in aging mice. Exp Gerontol 2006; 42:296-300. [PMID: 17184947 DOI: 10.1016/j.exger.2006.10.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 10/18/2006] [Accepted: 10/24/2006] [Indexed: 10/23/2022]
Abstract
Aging is associated with an increased incidence of glucose intolerance and type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is an important insulinotropic peptide secreted from the gastrointestinal tract in response to nutrient absorption. The present study was designed to assess the sub-chronic glucose regulatory effects of the potent long-acting GLP-1 receptor agonist, (Val(8))GLP-1, in aging 45-49 week old mice. Daily injection of (Val(8))GLP-1 (25 n mol/kg body weight) for 12 days had no significant effect on food intake, body weight, non-fasting plasma glucose and insulin concentrations. However, after 12 days, the glycaemic response to intraperitoneal glucose was improved (P<0.05) in (Val(8))GLP-1 treated mice. In keeping with this, glucose-mediated insulin secretion was enhanced (P<0.05) and insulin sensitivity improved (P<0.05) compared to controls. These data indicate that sub-chronic activation of the GLP-1 receptor by daily treatment with (Val(8))GLP-1 counters aspects of the age-related impairment of pancreatic beta-cell function and insulin sensitivity.
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22
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Flatt PR, Green BD. Nutrient regulation of pancreatic β-cell function in diabetes: problems and potential solutions. Biochem Soc Trans 2006; 34:774-8. [PMID: 17052195 DOI: 10.1042/bst0340774] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Increasing prevalence of obesity combined with longevity will produce an epidemic of Type 2 (non-insulin-dependent) diabetes in the next 20 years. This disease is associated with defects in insulin secretion, specifically abnormalities of insulin secretory kinetics and pancreatic β-cell glucose responsiveness. Mechanisms underlying β-cell dysfunction include glucose toxicity, lipotoxicity and β-cell hyperactivity. Defects at various sites in β-cell signal transduction pathways contribute, but no single lesion can account for the common form of Type 2 diabetes. Recent studies highlight diverse β-cell actions of GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). These intestinal hormones target the β-cell to stimulate glucose-dependent insulin secretion through activation of protein kinase A and associated pathways. Both increase gene expression and proinsulin biosynthesis, protect against apoptosis and stimulate replication/neogenesis of β-cells. Incretin hormones therefore represent an exciting future multi-action solution to correct β-cell defect in Type 2 diabetes.
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Affiliation(s)
- P R Flatt
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, UK.
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23
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Kumar M, Hunag Y, Glinka Y, Prud'homme GJ, Wang Q. Gene therapy of diabetes using a novel GLP-1/IgG1-Fc fusion construct normalizes glucose levels in db/db mice. Gene Ther 2006; 14:162-72. [PMID: 16943856 DOI: 10.1038/sj.gt.3302836] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glucagon-like peptide (GLP-1), a major physiological incretin, plays numerous important roles in modulating blood glucose homeostasis and has been proposed for the treatment of type 2 diabetes. The major obstacles for using native GLP-1 as a therapeutic agent are that it must be delivered by a parenteral route and has a short half-life. In an attempt to develop a strategy to prolong the physiological t(1/2) and enhance the potency of GLP-1, a fusion protein consisting of active human GLP-1 and mouse IgG(1) heavy chain constant regions (GLP-1/Fc) was generated. A plasmid encoding an IgK leader peptide-driven secretable fusion protein of the active GLP-1 and IgG(1)-Fc was constructed for mammalian expression. This plasmid allows for expression of bivalent GLP-1 peptide ligands as a result of IgG-Fc homodimerization. In vitro studies employing purified GLP-1/Fc indicate that the fusion protein is functional and elevates cAMP levels in insulin-secreting INS-1 cells. In addition, it stimulates insulin secretion in a glucose concentration-dependent manner. Intramuscular gene transfer of the plasmid in db/db mice demonstrated that expression of the GLP-1/Fc peptide normalizes glucose tolerance by enhancing insulin secretion and suppressing glucagon release. This strategy of using a bivalent GLP-1/Fc fusion protein as a therapeutic agent is a novel approach for the treatment of diabetes.
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Affiliation(s)
- M Kumar
- Department of Medicine, University of Toronto, Ontario, Canada
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24
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Green BD, Lavery KS, Irwin N, O'harte FPM, Harriott P, Greer B, Bailey CJ, Flatt PR. Novel glucagon-like peptide-1 (GLP-1) analog (Val8)GLP-1 results in significant improvements of glucose tolerance and pancreatic beta-cell function after 3-week daily administration in obese diabetic (ob/ob) mice. J Pharmacol Exp Ther 2006; 318:914-21. [PMID: 16648370 DOI: 10.1124/jpet.105.097824] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This study evaluates the antidiabetic potential of an enzyme-resistant analog, (Val8)GLP-1. The effects of daily administration of a novel dipeptidyl peptidase IV-resistant glucagon-like peptide-1 (GLP-1) analog, (Val8)GLP-1, on glucose tolerance and pancreatic beta-cell function were examined in obese-diabetic (ob/ob) mice. Acute intraperitoneal administration of (Val8)GLP-1 (6.25-25 nmol/kg) with glucose increased the insulin response and reduced the glycemic excursion in a dose-dependent manner. The effects of (Val8)GLP-1 were greater and longer lasting than native GLP-1. Once-daily subcutaneous administration of (Val8)GLP-1 (25 nmol/kg) for 21 days reduced plasma glucose concentrations, increased plasma insulin, and reduced body weight more than native GLP-1 without a significant change in daily food intake. Furthermore, (Val8)GLP-1 improved glucose tolerance, reduced the glycemic excursion after feeding, increased the plasma insulin response to glucose and feeding, and improved insulin sensitivity. These effects were consistently greater with (Val8)GLP-1 than with native GLP-1, and both peptides retained or increased their acute efficacy compared with initial administration. (Val8)GLP-1 treatment increased average islet area 1.2-fold without changing the number of islets, resulting in an increased number of larger islets. These data demonstrate that (Val8)GLP-1 is more effective and longer acting than native GLP-1 in obese-diabetic ob/ob mice.
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Affiliation(s)
- Brian D Green
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK.
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25
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Abstract
The coexistence of type 2 diabetes and obesity presents a complex therapeutic challenge. Future combination tablets may include agents to address diabetes and any accompanying cardiovascular risk factors. Injectable agents that improve glycemic control and facilitate weight loss have recently become available: the soluble amylin analogue pramlintide provides an adjunct to insulin therapy in type 1 and type 2 diabetes, and the incretin mimetic exenatide can enhance prandial insulin release in type 2 diabetes. Orally active inhibitors of the incretin-degrading enzyme dipeptidyl peptidase-IV, agonists of peroxisome proliferator-activated receptor (PPAR)-a and PPAR-g ("dual PPARs"), and the CB1 cannabinoid receptor inhibitor rimonabant are advanced in clinical development. Many novel antidiabetic and antiobesity compounds are emerging in preclinical development.
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Affiliation(s)
- Clifford J Bailey
- Diabetes Group, Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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26
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Green BD, Liu HK, McCluskey JT, Duffy NA, O'Harte FPM, McClenaghan NH, Flatt PR. Function of a long-term, GLP-1-treated, insulin-secreting cell line is improved by preventing DPP IV-mediated degradation of GLP-1. Diabetes Obes Metab 2005; 7:563-9. [PMID: 16050949 DOI: 10.1111/j.1463-1326.2004.00430.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is an important insulinotropic hormone with potential in the treatment of type 2 diabetes. However, the short biological half-life of the peptide after cleavage by dipeptidylpeptidase IV (DPP IV) is a major limitation. Inhibition of DPP IV activity and the development of resistant GLP-1 analogues is the subject of ongoing research. In this study, we determined cell growth, insulin content, insulin accumulation and insulin secretory function of a insulin-secreting cell line cultured for 3 days with either GLP-1, GLP-1 plus the DPP IV inhibitor diprotin A (DPA) or stable N-acetyl-GLP-1. Native GLP-1 was rapidly degraded by DPP IV during culture with accumulation of the inactive metabolite GLP-1(9-36)amide. Inclusion of DPA or use of the DPP IV-resistant analogue, N-acetyl-GLP-1, improved cellular function compared to exposure to GLP-1 alone. Most notably, basal and accumulated insulin secretion was enhanced, and glucose responsiveness was improved. However, prolonged GLP-1 treatment resulted in GLP-1 receptor desensitization regardless of DPP IV status. The results indicate that prevention of DPP IV action is necessary for beneficial effects of GLP-1 on pancreatic beta cells and that prolonged exposure to GLP-1(9-36)amide may be detrimental to insulin secretory function. These observations also support the ongoing development of DPP-IV-resistant forms of GLP-1, such as N-acetyl-GLP-1.
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Affiliation(s)
- B D Green
- School of Biomedical Sciences, University of Ulster, Coleraine, N. Ireland, UK.
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27
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Green BD, Gault VA, O'Harte FPM, Flatt PR. A comparison of the cellular and biological properties of DPP-IV-resistant N-glucitol analogues of glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. Diabetes Obes Metab 2005; 7:595-604. [PMID: 16050953 DOI: 10.1111/j.1463-1326.2004.00455.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The two major incretin hormones--glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)--are being actively researched by the pharmaceutical industry because of their glucose-lowering and potential anti-diabetic properties. Unfortunately, the inactivation of GLP-1 and GIP in the circulation brought about by dipeptidyl-peptidase-IV (DPP-IV) degradation makes their biological actions short-lived. This study directly compares the cellular and biological properties of GLP-1, GIP and their N-terminally modified counterparts, with glucitol extension at positions His7 and Tyr1 respectively, to confer DPP-IV resistance. METHODS Using both the glucose-responsive pancreatic beta-cell line, BRIN BD11, and the obese diabetic (ob/ob) mouse, we assessed adenosine 3',5'-cyclic monophosphate (cAMP) production and insulinotropic action in vitro as well as in vivo glucose-lowering and insulin-releasing actions. RESULTS The results reveal that glycation of the N-terminus of GLP-1 or GIP stabilized both peptides against DPP-IV degradation. However, N-glucitol-GLP-1 displayed reduced cAMP production, insulinotropic activity and glucose-lowering potency, compared to native GLP-1. By contrast, N-glucitol-GIP exhibited substantially improved biological activities, compared to native GIP, and possessed similar or enhanced in vivo potency to GLP-1. N-terminal extension by means of glucitol addition is more beneficial to bioactivity of GIP than it is to GLP-1. CONCLUSIONS N-terminal glycation generates a super GIP agonist, which possesses acute in vivo glucose-lowering and insulinotropic actions superior to native GLP-1. Therefore, N-glucitol-GIP is a particularly attractive potential candidate molecule for drug therapy of type 2 diabetes.
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Affiliation(s)
- B D Green
- School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK.
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28
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Irwin N, Green BD, Gault VA, Greer B, Harriott P, Bailey CJ, Flatt PR, O'Harte FPM. Degradation, insulin secretion, and antihyperglycemic actions of two palmitate-derivitized N-terminal pyroglutamyl analogues of glucose-dependent insulinotropic polypeptide. J Med Chem 2005; 48:1244-50. [PMID: 15715491 DOI: 10.1021/jm049262s] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Exploitation of glucose-dependent insulinotropic polypeptide (GIP) is hindered by its short biological half-life and rapid renal clearance. To circumvent these problems, two novel acylated N-terminally modified GIP analogues, N-pGluGIP(LysPAL(16)) and N-pGluGIP(LysPAL(37)), were evaluated. In contrast to native GIP, both analogues were completely resistant to dipeptidyl peptidase IV degradation. In GIP-receptor transfected fibroblasts, N-pGluGIP(LysPAL(16)) and N-pGluGIP(LysPAL(37)) exhibited enhanced stimulation of cAMP production. Insulinotropic responses in clonal beta-cells were similar to native GIP. When administered together with glucose to ob/ob mice, the glycemic excursions were significantly less for both analogues and insulin responses were greater than native GIP. Extended insulinotropic and antihyperglycemic actions were also evident. These data indicate that palmitate-derivitized analogues of N-terminal pyroglutamyl GIP represent a novel class of stable, long-acting, and effective GIP analogues for potential type 2 diabetes therapy.
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Affiliation(s)
- Nigel Irwin
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, UK
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29
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Furman B, Pyne N, Flatt P, O'Harte F. Targeting beta-cell cyclic 3'5' adenosine monophosphate for the development of novel drugs for treating type 2 diabetes mellitus. A review. J Pharm Pharmacol 2005; 56:1477-92. [PMID: 15563754 DOI: 10.1211/0022357044805] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Cyclic 3'5'AMP is an important physiological amplifier of glucose-induced insulin secretion by the pancreatic islet beta-cell, where it is formed by the activity of adenylyl cyclase, especially in response to the incretin hormones GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic peptide). These hormones are secreted from the small intestine during and following a meal, and are important in producing a full insulin secretory response to nutrient stimuli. Cyclic AMP influences many steps involved in glucose-induced insulin secretion and may be important in regulating pancreatic islet beta-cell differentiation, growth and survival. Cyclic AMP (cAMP) itself is rapidly degraded in the pancreatic islet beta-cell by cyclic nucleotide phosphodiesterase (PDE) enzymes. This review discusses the possibility of targeting cAMP mechanisms in the treatment of type 2 diabetes mellitus, in which insulin release in response to glucose is impaired. This could be achieved by the use of GLP-1 or GIP to elevate cAMP in the pancreatic islet beta-cell. However, these peptides are normally rapidly degraded by dipeptidyl peptidase IV (DPP IV). Thus longer-acting analogues of GLP-1 and GIP, resistant to enzymic degradation, and orally active inhibitors of DPP IV have also been developed, and these agents were found to improve metabolic control in experimentally diabetic animals and in patients with type 2 diabetes. The use of selective inhibitors of type 3 phosphodiesterase (PDE3B), which is probably the important pancreatic islet beta-cell PDE isoform, would require their targeting to the islet beta-cell, because inhibition of PDE3B in adipocytes and hepatocytes would induce insulin resistance.
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Affiliation(s)
- Brian Furman
- Department of Physiology and Pharmacology, University of Strathclyde, Strathclyde Institute for Biomedical Sciences, Taylor Street, Glasgow G4 ONR, UK.
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31
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Green BD, Gault VA, Mooney MH, Irwin N, Harriott P, Greer B, Bailey CJ, O'Harte FPM, Flatt PR. Degradation, receptor binding, insulin secreting and antihyperglycaemic actions of palmitate-derivatised native and Ala8-substituted GLP-1 analogues. Biol Chem 2004; 385:169-77. [PMID: 15101559 DOI: 10.1515/bc.2004.035] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The hormone glucagon-like peptide-1(7-36)amide (GLP-1) is released in response to ingested nutrients and acts to promote glucose-dependent insulin secretion ensuring efficient postprandial glucose homeostasis. Unfortunately, the beneficial actions of GLP-1 which give this hormone many of the desirable properties of an antidiabetic drug are short lived due to degradation by dipeptidyl-peptidase IV (DPP IV) and rapid clearance by renal filtration. In this study we have attempted to extend GLP-1 action through the attachment of palmitoyl moieties to the epsilon-amino group in the side chain of the Lys26 residue and to combine this modification with substitutions of the Ala8 residue, namely Val or amino-butyric acid (Abu). In contrast to native GLP-1, which was rapidly degraded, [Lys(pal)26]GLP-1, [Abu8, Lys(pal)26]GLP-1 and [Val8 Lys(pal)26]GLP-1 all exhibited profound stability during 12 h incubations with DPP IV and human plasma. Receptor binding affinity and the ability to increase cyclic AMP in the clonal beta-cell line BRIN-BD11 were decreased by 86- to 167-fold and 15- to 62-fold, respectively compared with native GLP-1. However, insulin secretory potency tested using BRIN-BD11 cells was similar, or in the case of [Val8,Lys(pal)26]GLP-1 enhanced. Furthermore, when administered in vivo together with glucose to diabetic (ob/ob) mice, [Lys(pal)26]GLP-1, [Abu8,Lys(pal)26]GLP-1 and [Val8,Lys(pal)26]GLP-1 did not demonstrate acute glucose-lowering or insulinotropic activity as observed with native GLP-1. These studies support the potential usefulness of fatty acid linked analogues of GLP-1 but indicate the importance of chain length for peptide kinetics and bioavailability.
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Affiliation(s)
- Brian D Green
- School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK.
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