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Cheng CK, Luo JY, Lau CW, Cho WCS, Ng CF, Ma RCW, Tian XY, Huang Y. A GLP-1 analog lowers ER stress and enhances protein folding to ameliorate homocysteine-induced endothelial dysfunction. Acta Pharmacol Sin 2021; 42:1598-1609. [PMID: 33495519 PMCID: PMC8463564 DOI: 10.1038/s41401-020-00589-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/15/2020] [Indexed: 02/02/2023] Open
Abstract
Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular diseases and increases mortality in type 2 diabetic patients. HHcy induces endoplasmic reticulum (ER) stress and oxidative stress to impair endothelial function. The glucagon-like peptide 1 (GLP-1) analog exendin-4 attenuates endothelial ER stress, but the detailed vasoprotective mechanism remains elusive. The present study investigated the beneficial effects of exendin-4 against HHcy-induced endothelial dysfunction. Exendin-4 pretreatment reversed homocysteine-induced impairment of endothelium-dependent relaxations in C57BL/6 mouse aortae ex vivo. Four weeks subcutaneous injection of exendin-4 restored the impaired endothelial function in both aortae and mesenteric arteries isolated from mice with diet-induced HHcy. Exendin-4 treatment lowered superoxide anion accumulation in the mouse aortae both ex vivo and in vivo. Exendin-4 decreased the expression of ER stress markers (e.g., ATF4, spliced XBP1, and phosphorylated eIF2α) in human umbilical vein endothelial cells (HUVECs), and this change was reversed by cotreatment with compound C (CC) (AMPK inhibitor). Exendin-4 induced phosphorylation of AMPK and endothelial nitric oxide synthase in HUVECs and arteries. Exendin-4 increased the expression of endoplasmic reticulum oxidoreductase (ERO1α), an important ER chaperone in endothelial cells, and this effect was mediated by AMPK activation. Experiments using siRNA-mediated knockdown or adenoviral overexpression revealed that ERO1α mediated the inhibitory effects of exendin-4 on ER stress and superoxide anion production, thus ameliorating HHcy-induced endothelial dysfunction. The present results demonstrate that exendin-4 reduces HHcy-induced ER stress and improves endothelial function through AMPK-dependent ERO1α upregulation in endothelial cells and arteries. AMPK activation promotes the protein folding machinery in endothelial cells to suppress ER stress.
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Affiliation(s)
- Chak Kwong Cheng
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, China
- Heart and Vascular Institute and Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jiang-Yun Luo
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, China
- Heart and Vascular Institute and Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chi Wai Lau
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, China
- Heart and Vascular Institute and Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - William Chi-Shing Cho
- Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong SAR, China
| | - Chi Fai Ng
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ronald Ching Wan Ma
- Department of Medicine and Therapeutics, Hong Kong Institute of Diabetes and Obesity, and The Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiao Yu Tian
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, China.
- Heart and Vascular Institute and Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | - Yu Huang
- School of Biomedical Sciences and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong SAR, China.
- Heart and Vascular Institute and Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Han J, Huang Y, Chen X, Zhou F, Fei Y, Fu J. Rational design of dimeric lipidated Xenopus glucagon-like peptide 1 analogues as long-acting antihyperglycaemic agents. Eur J Med Chem 2018; 157:177-187. [DOI: 10.1016/j.ejmech.2018.07.072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/12/2018] [Accepted: 07/29/2018] [Indexed: 12/15/2022]
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Stocks BB, Melanson JE. In-Source Reduction of Disulfide-Bonded Peptides Monitored by Ion Mobility Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:742-751. [PMID: 29450858 DOI: 10.1007/s13361-018-1894-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/15/2018] [Accepted: 01/18/2018] [Indexed: 06/08/2023]
Abstract
Many peptides with antimicrobial activity and/or therapeutic potential contain disulfide bonds as a means to enhance stability, and their quantitation is often performed using electrospray ionization mass spectrometry (ESI-MS). Disulfides can be reduced during ESI under commonly used instrument conditions, which has the potential to hinder accurate peptide quantitation. We demonstrate that this in-source reduction (ISR) is predominantly observed for peptides infused from acidic solutions and subjected to elevated ESI voltages (3-4 kV). ISR is readily apparent in the mass spectrum of oxytocin-a small, single disulfide-containing peptide. However, subtle m/z shifts due to partial ISR of highly charged (z ≥ 3) peptides with multiple disulfide linkages may proceed unnoticed. Ion mobility (IM)-MS separates ions on the basis of charge and shape in the gas phase, and using insulin as a model system, we show that IM-MS arrival time distributions (ATDs) are particularly sensitive to partial ISR of large peptides. Isotope modeling allows for the relative quantitation of disulfide-intact and partially reduced states of the mobility-separated peptide conformers. Interestingly, hepcidin peptides ionized from acidic solutions at elevated ESI voltages undergo gas-phase compaction, ostensibly due to partial disulfide ISR. Our IM-MS results lead us to propose that residual acid is the likely cause of disparate ATDs recently measured for hepcidin from different suppliers [Anal. Bioanal. Chem. 409, 2559-2567 (2017)]. Overall, our results demonstrate the utility of IM-MS to detect partial ISR of disulfide-bonded peptides and reinforce the notion that peptide/protein measurements should be carried out using minimally activating instrument conditions. Graphical Abstract ᅟ.
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Affiliation(s)
- Bradley B Stocks
- National Research Council of Canada, Measurement Science and Standards, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada.
| | - Jeremy E Melanson
- National Research Council of Canada, Measurement Science and Standards, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
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Lakbub JC, Shipman JT, Desaire H. Recent mass spectrometry-based techniques and considerations for disulfide bond characterization in proteins. Anal Bioanal Chem 2017; 410:2467-2484. [PMID: 29256076 DOI: 10.1007/s00216-017-0772-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/09/2017] [Accepted: 11/17/2017] [Indexed: 12/21/2022]
Abstract
Disulfide bonds are important structural moieties of proteins: they ensure proper folding, provide stability, and ensure proper function. With the increasing use of proteins for biotherapeutics, particularly monoclonal antibodies, which are highly disulfide bonded, it is now important to confirm the correct disulfide bond connectivity and to verify the presence, or absence, of disulfide bond variants in the protein therapeutics. These studies help to ensure safety and efficacy. Hence, disulfide bonds are among the critical quality attributes of proteins that have to be monitored closely during the development of biotherapeutics. However, disulfide bond analysis is challenging because of the complexity of the biomolecules. Mass spectrometry (MS) has been the go-to analytical tool for the characterization of such complex biomolecules, and several methods have been reported to meet the challenging task of mapping disulfide bonds in proteins. In this review, we describe the relevant, recent MS-based techniques and provide important considerations needed for efficient disulfide bond analysis in proteins. The review focuses on methods for proper sample preparation, fragmentation techniques for disulfide bond analysis, recent disulfide bond mapping methods based on the fragmentation techniques, and automated algorithms designed for rapid analysis of disulfide bonds from liquid chromatography-MS/MS data. Researchers involved in method development for protein characterization can use the information herein to facilitate development of new MS-based methods for protein disulfide bond analysis. In addition, individuals characterizing biotherapeutics, especially by disulfide bond mapping in antibodies, can use this review to choose the best strategies for disulfide bond assignment of their biologic products. Graphical Abstract This review, describing characterization methods for disulfide bonds in proteins, focuses on three critical components: sample preparation, mass spectrometry data, and software tools.
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Affiliation(s)
- Jude C Lakbub
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS, 66045, USA
| | - Joshua T Shipman
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS, 66045, USA
| | - Heather Desaire
- Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS, 66045, USA.
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Novel application of hydrophobin in medical science: a drug carrier for improving serum stability. Sci Rep 2016; 6:26461. [PMID: 27212208 PMCID: PMC4876437 DOI: 10.1038/srep26461] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/04/2016] [Indexed: 01/13/2023] Open
Abstract
Multiple physiological properties of glucagon-like peptide-1 (GLP-1) ensure that it is a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short because of rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor serum stability of GLP-1 has significantly limited its clinical utility, although many studies are focused on extending the serum stability of this molecule. Hydrophobin, a self-assembling protein, was first applied as drug carrier to stabilize GLP-1 against protease degradation by forming a cavity. The glucose tolerance test clarified that the complex retained blood glucose clearance activity for 72 hours suggesting that this complex might be utilized as a drug candidate administered every 2–3 days. Additionally, it was found that the mutagenesis of hydrophobin preferred a unique pH condition for self-assembly. These findings suggested that hydrophobin might be a powerful tool as a drug carrier or a pH sensitive drug-release compound. The novel pharmaceutical applications of hydrophobin might result in future widespread interest in hydrophobin.
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Tsiamantas C, de Hatten X, Douat C, Kauffmann B, Maurizot V, Ihara H, Takafuji M, Metzler-Nolte N, Huc I. Selective Dynamic Assembly of Disulfide Macrocyclic Helical Foldamers with Remote Communication of Handedness. Angew Chem Int Ed Engl 2016; 55:6848-52. [DOI: 10.1002/anie.201601156] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Christos Tsiamantas
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Xavier de Hatten
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Céline Douat
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Brice Kauffmann
- University of Bordeaux; Institut Européen de Chimie et Biologie (UMS3033); 2 rue Escarpit 33600 Pessac France
- CNRS, IECB (UMS 3033); Pessac France
- INSERM, IECB (US 001); Pessac France
| | - Victor Maurizot
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Hirotaka Ihara
- Kumamoto University; Department of Applied Chemistry and Biochemistry; 2-39-1 Kurokami Kumamoto 860-8555 Japan
| | - Makoto Takafuji
- Kumamoto University; Department of Applied Chemistry and Biochemistry; 2-39-1 Kurokami Kumamoto 860-8555 Japan
| | - Nils Metzler-Nolte
- Ruhr University Bochum; Faculty for Chemistry and Biochemistry; Universitätstrasse 150 44801 Bochum Germany
| | - Ivan Huc
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
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Tsiamantas C, de Hatten X, Douat C, Kauffmann B, Maurizot V, Ihara H, Takafuji M, Metzler-Nolte N, Huc I. Selective Dynamic Assembly of Disulfide Macrocyclic Helical Foldamers with Remote Communication of Handedness. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601156] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Christos Tsiamantas
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Xavier de Hatten
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Céline Douat
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Brice Kauffmann
- University of Bordeaux; Institut Européen de Chimie et Biologie (UMS3033); 2 rue Escarpit 33600 Pessac France
- CNRS, IECB (UMS 3033); Pessac France
- INSERM, IECB (US 001); Pessac France
| | - Victor Maurizot
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
| | - Hirotaka Ihara
- Kumamoto University; Department of Applied Chemistry and Biochemistry; 2-39-1 Kurokami Kumamoto 860-8555 Japan
| | - Makoto Takafuji
- Kumamoto University; Department of Applied Chemistry and Biochemistry; 2-39-1 Kurokami Kumamoto 860-8555 Japan
| | - Nils Metzler-Nolte
- Ruhr University Bochum; Faculty for Chemistry and Biochemistry; Universitätstrasse 150 44801 Bochum Germany
| | - Ivan Huc
- University of Bordeaux, CBMN (UMR 5248); Institut Européen de Chimie et Biologie; 2 rue Escarpit 33600 Pessac France
- CNRS, CBMN (UMR 5248); France
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Lee CY. Glucagon-Like Peptide-1 Formulation--the Present and Future Development in Diabetes Treatment. Basic Clin Pharmacol Toxicol 2015; 118:173-80. [PMID: 26551045 DOI: 10.1111/bcpt.12524] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/29/2015] [Indexed: 12/17/2022]
Abstract
Type 2 diabetes mellitus is a chronic metabolic disorder that has become the fourth leading cause of death in the developed countries. The disorder is characterized by pancreatic β-cells dysfunction, which causes hyperglycaemia leading to several other complications. Treatment by far, which focuses on insulin administration and glycaemic control, has not been satisfactory. Glucagon-like peptide-1 (GLP1) is an endogenous peptide that stimulates post-prandial insulin secretion. Despite being able to mimic the effect of insulin, GLP1 has not been the target drug in diabetes treatment due to the peptide's metabolic instability. After a decade-long effort to improve the pharmacokinetics of GLP1, a number of GLP1 analogues are currently available on the market. The current Minireview does not discuss these drugs but presents strategies that were undertaken to address the weaknesses of the native GLP1, particularly drug delivery techniques used in developing GLP1 nanoparticles and modified GLP1 molecule. The article highlights how each of the selected preparations has improved the efficacy of GLP1, and more importantly, through an overview of these studies, it will provide an insight into strategies that may be adopted in the future in the development of a more effective oral GLP1 formulation.
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Affiliation(s)
- Chooi Yeng Lee
- School of Pharmacy, Monash University Malaysia, Selangor, Malaysia
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Yang X, Li Y, Wang Y, Zheng X, Kong W, Meng F, Zhou Z, Liu C, Li Y, Gong M. Long-Acting GLP-1 Analogue in V-Shaped Conformation by Terminal Polylysine Modifications. Mol Pharm 2014; 11:4092-9. [PMID: 25243635 DOI: 10.1021/mp5002685] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Xue Yang
- Department of Pharmacy, Tianjin Traditional Medicine University, Tianjin, China
| | - Ying Li
- Tianjin Neurological
Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Yuli Wang
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Xuemin Zheng
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Weiling Kong
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Fancui Meng
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Zhixing Zhou
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Changxiao Liu
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
| | - Ying Li
- Tianjin Neurological
Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Min Gong
- Tianjin Institute of Pharmaceutical Research, Tianjin, China
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Han J, Sun L, Huang X, Li Z, Zhang C, Qian H, Huang W. Novel coumarin modified GLP-1 derivatives with enhanced plasma stability and prolonged in vivo glucose-lowering ability. Br J Pharmacol 2014; 171:5252-64. [PMID: 25039358 DOI: 10.1111/bph.12843] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 02/04/2014] [Accepted: 06/30/2014] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE The short biological half-life limits the therapeutic use of glucagon-like peptide-1 (GLP-1) and chemical modification to improve the interaction of peptides with serum albumin represents an effective strategy to develop long-acting peptide analogues. Coumarin, a natural product, is known to bind tightly to plasma proteins and possesses many biological activities. Therefore, we designed and synthesized a series of coumarin-modified GLP-1 derivatives, hypothesizing that conjugation with coumarin would retain the therapeutic effects and prolong the biological half-life of the conjugates. EXPERIMENTAL APPROACH Four cysteine-modified GLP-1 analogues (1-4) were prepared using Gly8 -GLP-1(7-36)-NH2 peptide as a starting point. These analogues were conjugated with two coumarin maleimides to yield eight compounds (conjugates 6-13) for testing. Activation of human GLP-1 receptors, stability to enzymic inactivation in plasma and binding to human albumin were assessed in vitro. In vivo, effects on oral glucose tolerance tests (OGTT) in rats and on blood glucose levels in db/db mice were studied. KEY RESULTS Most conjugates showed well preserved receptor activation efficacy, enhanced albumin-binding properties and improved in vitro plasma stability and conjugate 7 was selected to undergo further assessment. In rats, conjugate 7 had a longer circulating t1/2 than exendin-4 or liraglutide. A prolonged antidiabetic effect of conjugate 7 was observed after OGTT in rats and a prolonged hypoglycaemic effect in db/db mice. CONCLUSIONS AND IMPLICATIONS Cysteine-specific coumarin conjugation with GLP-1 offers a useful approach to the development of long-acting incretin-based antidiabetic agents. Conjugate 7 is a promising long-lasting GLP-1 derivative deserving further investigation.
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Affiliation(s)
- Jing Han
- Center of Drug Discovery, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
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12
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Góngora-Benítez M, Tulla-Puche J, Albericio F. Multifaceted Roles of Disulfide Bonds. Peptides as Therapeutics. Chem Rev 2013; 114:901-26. [DOI: 10.1021/cr400031z] [Citation(s) in RCA: 388] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Miriam Góngora-Benítez
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Judit Tulla-Puche
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
| | - Fernando Albericio
- Institute
for Research in Biomedicine (IRB Barcelona), Barcelona, 08028 Spain
- CIBER-BBN, Barcelona Science
Park, Barcelona, 08028 Spain
- Department
of Organic Chemistry, University of Barcelona, Barcelona, 08028 Spain
- School of Chemistry & Physics, University of KwaZulu-Natal, 4001 Durban, South Africa
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13
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Gao M, Tong Y, Gao X, Yao W. A mutated glucagon-like peptide-1 with improved glucose-lowering activity in diabetic mice. J Pharm Pharmacol 2013; 65:539-46. [PMID: 23488782 DOI: 10.1111/jphp.12011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 10/11/2012] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The aim of this study was to characterize the conformation and potency of a mutated glucagon-like peptide-1 (mGLP-1), and evaluate its glucose-lowering activity in diabetic mice. METHODS Spectroscopy techniques were employed to characterize the conformation of mGLP-1. Glucose tolerance test was performed to determine the potency of mGLP-1 in vivo. A mouse model in which diabetes was induced by multiple low doses of streptozotocin was established to evaluate the glucose-lowering activity of mGLP-1. KEY FINDINGS Compared with native GLP-1, mGLP-1 had a similar conformation and an enhanced potency in vivo. In diabetic mice, mGLP-1 displayed a significantly improved glucose-lowering activity as judged by fasting glucose and insulin, oral glucose tolerance test, beta cell function analysis and histochemical analysis. CONCLUSIONS Collectively, mGLP-1 possesses an improved glucose-lowering activity in vivo and therefore can be recognized as a potential candidate for the future development of anti-diabetic drugs.
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Affiliation(s)
- Mingming Gao
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
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Kim PH, Kim SW. Polymer-based delivery of glucagon-like Peptide-1 for the treatment of diabetes. ISRN ENDOCRINOLOGY 2012; 2012:340632. [PMID: 22701182 PMCID: PMC3369441 DOI: 10.5402/2012/340632] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 03/16/2012] [Indexed: 01/19/2023]
Abstract
The incretin hormones, glucagon-like peptide-1 (GLP-1) and its receptor agonist (exendin-4), are well known for glucose homeostasis, insulinotropic effect, and effects on weight loss and food intake. However, due to the rapid degradation of GLP-1 by dipeptidylpeptidase-IV (DPP-IV) enzyme and renal elimination of exendin-4, their clinical applications have been restricted. Although exendin-4 has longer half-life than GLP-1, it still requires frequent injections to maintain efficacy for the treatment of diabetes. In recent decades, various polymeric delivery systems have been developed for the delivery of GLP-1 and exendin-4 genes or peptides for their long-term action and the extra production in ectopic tissues. Herein, we discuss the modification of the expression cassettes and peptides for long-term production and secretion of the native peptides. In addition, the characteristics of nonviral or viral system used for a delivery of a modified GLP-1 or exendin-4 are described. Furthermore, recent efforts to improve the biological half-life of GLP-1 or exendin-4 peptide via chemical conjugation with various smart polymers via chemical conjugation compared with native peptide are discussed.
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Affiliation(s)
- Pyung-Hwan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Sung Wan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA
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