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Chaari A, Saikia N, Paul P, Yousef M, Ding F, Ladjimi M. Experimental and computational investigation of the effect of Hsc70 structural variants on inhibiting amylin aggregation. Biophys Chem 2024; 309:107235. [PMID: 38608617 DOI: 10.1016/j.bpc.2024.107235] [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: 01/06/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024]
Abstract
The misfolding and aggregation of human islet amyloid polypeptide (hIAPP), also known as amylin, have been implicated in the pathogenesis of type 2 diabetes (T2D). Heat shock proteins, specifically, heat shock cognate 70 (Hsc70), are molecular chaperones that protect against hIAPP misfolding and inhibits its aggregation. Nevertheless, there is an incomplete understanding of the mechanistic interactions between Hsc70 domains and hIAPP, thus limiting their potential therapeutic role in diabetes. This study investigates the inhibitory capacities of different Hsc70 variants, aiming to identify the structural determinants that strike a balance between efficacy and cytotoxicity. Our experimental findings demonstrate that the ATPase activity of Hsc70 is not a pivotal factor for inhibiting hIAPP misfolding. We underscore the significance of the C-terminal substrate-binding domain of Hsc70 in inhibiting hIAPP aggregation, emphasizing that the removal of the lid subdomain diminishes the inhibitory effect of Hsc70. Additionally, we employed atomistic discrete molecular dynamics simulations to gain deeper insights into the interaction between Hsc70 variants and hIAPP. Integrating both experimental and computational findings, we propose a mechanism by which Hsc70's interaction with hIAPP monomers disrupts protein-protein connections, primarily by shielding the β-sheet edges of the Hsc70-β-sandwich. The distinctive conformational dynamics of the alpha helices of Hsc70 potentially enhance hIAPP binding by obstructing the exposed edges of the β-sandwich, particularly at the β5-β8 region along the alpha helix interface. This, in turn, inhibits fibril growth, and similar results were observed following hIAPP dimerization. Overall, this study elucidates the structural intricacies of Hsc70 crucial for impeding hIAPP aggregation, improving our understanding of the potential anti-aggregative properties of molecular chaperones in diabetes treatment.
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Affiliation(s)
- Ali Chaari
- Weill Cornell Medicine-Qatar, Qatar Foundation-Education City, P.O. Box 24144, Doha, Qatar.
| | - Nabanita Saikia
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Pradipta Paul
- Weill Cornell Medicine-Qatar, Qatar Foundation-Education City, P.O. Box 24144, Doha, Qatar
| | - Mohammad Yousef
- Weill Cornell Medicine-Qatar, Qatar Foundation-Education City, P.O. Box 24144, Doha, Qatar
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Moncef Ladjimi
- Weill Cornell Medicine-Qatar, Qatar Foundation-Education City, P.O. Box 24144, Doha, Qatar
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2
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Laxio Arenas J, Lesma J, Ha-Duong T, Ranjan Sahoo B, Ramamoorthy A, Tonali N, Soulier JL, Halgand F, Giraud F, Crousse B, Kaffy J, Ongeri S. Composition and Conformation of Hetero- versus Homo-Fluorinated Triazolamers Influence their Activity on Islet Amyloid Polypeptide Aggregation. Chemistry 2024; 30:e202303887. [PMID: 38478740 DOI: 10.1002/chem.202303887] [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: 11/22/2023] [Indexed: 04/11/2024]
Abstract
Novel fluorinated foldamers based on aminomethyl-1,4-triazolyl-difluoroacetic acid (1,4-Tz-CF2) units were synthesized and their conformational behaviour was studied by NMR and molecular dynamics. Their activity on the aggregation of the human islet amyloid polypeptide (hIAPP) amyloid protein was evaluated by fluorescence spectroscopy and mass spectrometry. The fluorine labelling of these foldamers allowed the analysis of their interaction with the target protein. We demonstrated that the preferred extended conformation of homotriazolamers of 1,4-Tz-CF2 unit increases the aggregation of hIAPP, while the hairpin-like conformation of more flexible heterotriazolamers containing two 1,4-Tz-CF2 units mixed with natural amino acids from the hIAPP sequence reduces it, and more efficiently than the parent natural peptide. The longer heterotriazolamers having three 1,4-Tz-CF2 units adopting more folded hairpin-like and ladder-like structures similar to short multi-stranded β-sheets have no effect. This work demonstrates that a good balance between the structuring and flexibility of these foldamers is necessary to allow efficient interaction with the target protein.
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Affiliation(s)
- José Laxio Arenas
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Jacopo Lesma
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Tap Ha-Duong
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Bikash Ranjan Sahoo
- Biophysics, Department of Chemistry, Biomedical Engineering, Michigan Neuroscience Institute, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Michigan Neuroscience Institute, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Nicolo Tonali
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Jean-Louis Soulier
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Frédéric Halgand
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405, Orsay, France
| | - François Giraud
- Equipe Biologie et Chimie Structurales, Dept Chimie et Biologie Structurales et Analytiques, ICSN, CNRS, Université Paris Saclay, 1 avenue de la terrasse, 91190, Gif sur Yvette, France
| | - Benoît Crousse
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Julia Kaffy
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
| | - Sandrine Ongeri
- Université Paris-Saclay, CNRS, BioCIS, Bat. Henri Moissan, 17 av. des Sciences, 91400, Orsay, France
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3
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Brunzell E, Sigfridsson K, Gedda L, Edwards K, Bergström LM. Investigation of supramolecular structures in various aqueous solutions of an amyloid forming peptide using small-angle X-ray scattering. SOFT MATTER 2024; 20:2272-2279. [PMID: 38353286 DOI: 10.1039/d3sm01172k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Aggregation of peptide molecules into amyloid fibrils is a characteristic feature of several degenerative diseases. However, the details behind amyloid-formation, and other self-assembled peptide aggregates, remain poorly understood. In this study, we have used small-angle X-ray scattering (SAXS), static and dynamic light scattering (SLS and DLS) as well as cryogenic transmission electron microscopy (cryo-TEM) to determine the structural geometry of self-assembled peptide aggregates in various dilute aqueous solutions. Pramlintide was used as a model peptide to assess the aggregation behaviour of an amyloid-forming peptide. The effects of adding sodium chloride (NaCl), sodium thiocyanate (NaSCN), and sodium fluoride (NaF) and the co-solvent dimethyl sulfoxide (DMSO) on the aggregation behaviour were studied. Our scattering data analysis demonstrates that small oligomeric fibrils aggregate to form networks of supramolecular assemblies with fractal dimensions. The choice of anion in small amounts of added salt has a significant impact on the size of the fibrils as well as on the fractal dimensions of supramolecular clusters. In DMSO the fractal dimension decreased with increasing DMSO concentration, indicating the formation of a less compact structure of the supramolecular assemblies.
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Affiliation(s)
- Ellen Brunzell
- Department of Medicinal Chemistry, Pharmaceutical Physical Chemistry, Uppsala University, Uppsala 751 23, Sweden.
| | - Kalle Sigfridsson
- Advanced Drug Delivery, Pharmaceutical Science, R&D, AstraZeneca, Gothenburg 431 83, Sweden
| | - Lars Gedda
- Department of Chemistry-Ångström, Uppsala University, P.O. Box 573, Uppsala 751 23, Sweden
| | - Katarina Edwards
- Department of Chemistry-Ångström, Uppsala University, P.O. Box 573, Uppsala 751 23, Sweden
| | - L Magnus Bergström
- Department of Medicinal Chemistry, Pharmaceutical Physical Chemistry, Uppsala University, Uppsala 751 23, Sweden.
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4
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Hsu C, Templin AT, Prosswimmer T, Shea D, Li J, Brooks‐Worrell B, Kahn SE, Daggett V. Human islet amyloid polypeptide-induced β-cell cytotoxicity is linked to formation of α-sheet structure. Protein Sci 2024; 33:e4854. [PMID: 38062941 PMCID: PMC10823758 DOI: 10.1002/pro.4854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 11/10/2023] [Accepted: 12/04/2023] [Indexed: 01/30/2024]
Abstract
Type 2 diabetes (T2D) results from insulin secretory dysfunction arising in part from the loss of pancreatic islet β-cells. Several factors contribute to β-cell loss, including islet amyloid formation, which is observed in over 90% of individuals with T2D. The amyloid is comprised of human islet amyloid polypeptide (hIAPP). Here we provide evidence that early in aggregation, hIAPP forms toxic oligomers prior to formation of amyloid fibrils. The toxic oligomers contain α-sheet secondary structure, a nonstandard secondary structure associated with toxic oligomers in other amyloid diseases. De novo, synthetic α-sheet compounds designed to be nontoxic and complementary to the α-sheet structure in the toxic oligomers inhibit hIAPP aggregation and neutralize oligomer-mediated cytotoxicity in cell-based assays. In vivo administration of an α-sheet design to mice for 4 weeks revealed no evidence of toxicity nor did it elicit an immune response. Furthermore, the α-sheet designs reduced endogenous islet amyloid formation and mitigation of amyloid-associated β-cell loss in cultured islets isolated from an hIAPP transgenic mouse model of islet amyloidosis. Characterization of the involvement of α-sheet in early aggregation of hIAPP and oligomer toxicity contributes to elucidation of the molecular mechanisms underlying amyloid-associated β-cell loss.
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Affiliation(s)
- Cheng‐Chieh Hsu
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
- Molecular Engineering ProgramUniversity of WashingtonSeattleWashingtonUSA
| | - Andrew T. Templin
- Division of Metabolism, Endocrinology and Nutrition, Department of MedicineVA Puget Sound Health Care System and University of WashingtonSeattleWashingtonUSA
| | - Tatum Prosswimmer
- Molecular Engineering ProgramUniversity of WashingtonSeattleWashingtonUSA
| | - Dylan Shea
- Molecular Engineering ProgramUniversity of WashingtonSeattleWashingtonUSA
| | - Jinzheng Li
- Department of BiochemistryUniversity of WashingtonSeattleWashingtonUSA
| | - Barbara Brooks‐Worrell
- Division of Metabolism, Endocrinology and Nutrition, Department of MedicineVA Puget Sound Health Care System and University of WashingtonSeattleWashingtonUSA
| | - Steven E. Kahn
- Division of Metabolism, Endocrinology and Nutrition, Department of MedicineVA Puget Sound Health Care System and University of WashingtonSeattleWashingtonUSA
| | - Valerie Daggett
- Department of BioengineeringUniversity of WashingtonSeattleWashingtonUSA
- Molecular Engineering ProgramUniversity of WashingtonSeattleWashingtonUSA
- Department of BiochemistryUniversity of WashingtonSeattleWashingtonUSA
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Moore KBE, Horgan NG, Lenters B, Fortin JS. Diabetes mellitus drug discovery: insights into targeting feline and human amylin with small molecules. Vet Q 2023; 43:1-12. [PMID: 37729105 PMCID: PMC10557562 DOI: 10.1080/01652176.2023.2260442] [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: 05/15/2023] [Accepted: 09/13/2023] [Indexed: 09/22/2023] Open
Abstract
BACKGROUND Type 2 diabetes (T2D) is a health concern for both humans and cats, with cases rising over the past decade. Around 70% of patients from either species exhibit pancreatic aggregates of islet amyloid polypeptide (IAPP), a protein that proves toxic upon misfolding. These misfolded protein aggregates congregate in the islets of Langerhans of the pancreas, diminishing the capability of β-cells to produce insulin and further perpetuating disease. OBJECTIVE Our team's drug discovery program is investigating newly synthesized compounds that could diminish aggregates of both human and feline IAPP, potentially disrupting the progression of T2D. MATERIAL AND METHODS We prepared 24 compounds derived from diaryl urea, as ureas have previously demonstrated great potential at reducing accumulations of misfolded proteins. Biophysical methods were employed to analyze the anti-aggregation activity of these compounds at inhibiting and/or disrupting IAPP fibril formation in vitro. RESULTS The results demonstrate that compounds 12 and 24 were most effective at reducing the fibrillization and aggregation of both human and feline IAPP. When compared with the control for each experiment, samples treated with either compound 12 or 24 exhibited fewer accumulations of amyloid-like fibrils. CONCLUSION Urea-based compounds, such as compounds 12 and 24, may prove crucial in future pre-clinical studies in the search for therapeutics for T2D.
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Affiliation(s)
- Kendall B. E. Moore
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - Natalie G. Horgan
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - Brooke Lenters
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
| | - Jessica S. Fortin
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA
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6
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Muñoz-Gutiérrez C, Adasme-Carreño F, Alzate-Morales J, Ireta J. Effect of strand register in the stability and reactivity of crystals from peptides forming amyloid fibrils. Phys Chem Chem Phys 2023; 25:23885-23893. [PMID: 37642522 DOI: 10.1039/d3cp01762a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Amyloids are cytotoxic protein aggregates that deposit in human tissues, leading to several health disorders. Their aggregates can also exhibit catalytic properties, and they have been used as candidates for the development of functional biomaterials. Despite being polymorphic, amyloids often assemble as cross-β fibrils formed by in-register β sheet layers. Recent studies of some amyloidogenic protein segments revealed that they crystallize as antiparallel out-of-register β sheets. Such arrangement has been proposed to be responsible for the cytotoxicity in amyloid diseases, however, there is still no consensus on the molecular mechanism. Interestingly, two amyloidogenic peptide segments, NFGAILS and FGAILSS, arrange into out-of-register and in-register β sheets, respectively, even though they solely differ by one aminoacid residue at both termini. In this work, we used density functional theory (DFT) to address how the strand register contributes into the packing and molecular properties of the NFGAILS and FGAILSS crystals. Our results show that the out-of-register structure is substantially more stable, at 0 K, than the in-register one due to stronger inter-strand contacts. Based on an analysis of the electrostatic potential of the crystal slabs, it is suggested that the out-of-register may potentially interact with negatively charged groups, like those found in cell membranes. Moreover, calculated reactivity descriptors indicate a similar outcome, where only the out-of-register peptide exhibits intrinsic reactive surface sites at the exposed amine and carboxylic groups. It is therefore suggested that the out-of-register arrangement may indeed be crucial for amyloid cytotoxicity. The findings presented here could help to further our understanding of amyloid aggregation, function, and toxicity.
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Affiliation(s)
- Camila Muñoz-Gutiérrez
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, 1 Poniente No. 1141, Box 721, Talca, Chile
| | - Francisco Adasme-Carreño
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3480112, Chile
- Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480112, Chile
| | - Jans Alzate-Morales
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, 1 Poniente No. 1141, Box 721, Talca, Chile
| | - Joel Ireta
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, A.P. 55-534, Ciudad de México 09340, Mexico.
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7
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Naskar S, Gour N. Realization of Amyloid-like Aggregation as a Common Cause for Pathogenesis in Diseases. Life (Basel) 2023; 13:1523. [PMID: 37511898 PMCID: PMC10381831 DOI: 10.3390/life13071523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/27/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Amyloids were conventionally referred to as extracellular and intracellular accumulation of Aβ42 peptide, which causes the formation of plaques and neurofibrillary tangles inside the brain leading to the pathogenesis in Alzheimer's disease. Subsequently, amyloid-like deposition was found in the etiology of prion diseases, Parkinson's disease, type II diabetes, and cancer, which was attributed to the aggregation of prion protein, α-Synuclein, islet amyloid polypeptide protein, and p53 protein, respectively. Hence, traditionally amyloids were considered aggregates formed exclusively by proteins or peptides. However, since the last decade, it has been discovered that other metabolites, like single amino acids, nucleobases, lipids, glucose derivatives, etc., have a propensity to form amyloid-like toxic assemblies. Several studies suggest direct implications of these metabolite assemblies in the patho-physiology of various inborn errors of metabolisms like phenylketonuria, tyrosinemia, cystinuria, and Gaucher's disease, to name a few. In this review, we present a comprehensive literature overview that suggests amyloid-like structure formation as a common phenomenon for disease progression and pathogenesis in multiple syndromes. The review is devoted to providing readers with a broad knowledge of the structure, mode of formation, propagation, and transmission of different extracellular amyloids and their implications in the pathogenesis of diseases. We strongly believe a review on this topic is urgently required to create awareness about the understanding of the fundamental molecular mechanism behind the origin of diseases from an amyloid perspective and possibly look for a common therapeutic strategy for the treatment of these maladies by designing generic amyloid inhibitors.
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Affiliation(s)
- Soumick Naskar
- Department of Chemistry, Indrashil University, Kadi, Mehsana 382740, Gujarat, India
| | - Nidhi Gour
- Department of Chemistry, Indrashil University, Kadi, Mehsana 382740, Gujarat, India
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8
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Caruso G, Di Pietro L, Cardaci V, Maugeri S, Caraci F. The therapeutic potential of carnosine: Focus on cellular and molecular mechanisms. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2023. [DOI: 10.1016/j.crphar.2023.100153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
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9
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Unnikrishnan AC, Shanmugam G. Isotope-edited vibrational circular dichroism study reveals a flexible N-terminal structure of islet amyloid peptide (NFGAIL) in amyloid fibril form: A site-specific local structural analysis. J Struct Biol 2022; 214:107910. [PMID: 36273786 DOI: 10.1016/j.jsb.2022.107910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/13/2022] [Accepted: 10/16/2022] [Indexed: 11/06/2022]
Abstract
The short peptide fragment NFGAIL (IAPf) is a well-known amyloidogenic peptide (22-27), derived from human islet amyloid polypeptide(hIAPP), whose fibrillar structure is often used to better understand the wild-type hIAPP amyloid fibrils, associated with type II diabetes. Despite an extensive study, the fibrillar structure of IAPf at the amino acid residue level is still unclear. Herein, the vibrational circular dichroism(VCD) spectroscopic technique coupled with isotope labelling strategy has been used to study the site-specific local structure of IAPf amyloid fibrils. Two 13C labeled IAPfs were designed and used along with unlabelled IAPf to achieve this. The 13C labelled (on -C=O) glycine(IAPf-G) and phenylalanine (IAPf-F) residues were introduced into the IAPf sequence separately by replacing natural glycine (residue 24) and phenylalanine (residue 23), respectively. VCD spectral analysis on IAPf-G suggests that IAPf fibrils adopt parallel β-sheet conformation with glycine residues are part of β-sheet and in-register. Unlike IAPf-G, VCD analysis on IAPf-F reveals that phenylalanine residues exist in the turn/hairpin conformation rather than β-sheet region. Both VCD results thus suggest that IAPf amyloid fibril consists of a mixture of β-sheet as a major conformation involving GAIL and turn/hairpin as a minor conformation involving NF rather than an idealized β-sheet involving all the amino acids. While previous studies speculated that the full NFGAIL sequence could participate in the β-sheet formation, the present site-specific structural analysis of IAPf amyloid fibrils at residue level using isotope-edited VCD has gained significant attention. Such residue level information has important implications for understanding the role of NFGAIL sequence in the amyloid fibrillation of hIAPP.
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Affiliation(s)
- Anagha C Unnikrishnan
- Organic & Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad- 201002, India
| | - Ganesh Shanmugam
- Organic & Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR) - Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India.
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10
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Manathunga L, Zhyvoloup A, Baghai A, Raleigh DP. Differential Effects of Aromatic Residues on Amyloid Formation and Cytotoxicity of Human IAPP. Biochemistry 2022; 61:2334-2343. [PMID: 36215164 PMCID: PMC11132793 DOI: 10.1021/acs.biochem.2c00267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Islet amyloid polypeptide (IAPP) is a 37-residue polypeptide hormone secreted by the pancreatic β-cells. IAPP plays a role in glycemic regulation, but in the pre-type-2 diabetic state, it aggregates to form an islet amyloid. The process of islet amyloid formation contributes to β-cell dysfunction and disease progression. The features of the IAPP sequence that modulate amyloid formation are still not understood. Human IAPP contains three aromatic residues, F15, F23, and Y37. F15 and Y37 are highly conserved, while F23 is more commonly a Leu or Ile in other species. The role of the aromatic residues in modulating the time course of amyloid formation and the cytotoxicity was examined using aromatic to Leu mutations. All three single and double mutants and the triple mutant were studied. F23 plays a dominant role in both amyloid formation and toxicity. An F15L mutant accelerated amyloid formation, a Y37L mutant had little effect, while an F23L replacement slowed amyloid formation by a factor of 2.6. Double mutants, which contained an F23L replacement, had a larger effect than those that did not, and there are non-additive effects between pairs of aromatic residues. F23 also plays a key role in toxicity. Single or multiple mutants that contain the F23L replacement were noticeably less toxic than the wild-type or mutants which did not include the F23L substitution. In contrast, the F15L mutant was more toxic than the wild-type one. The implications for IAPP amyloid formation and for the design of non-aggregating analogues of IAPP are discussed.
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Affiliation(s)
- Lakshan Manathunga
- Deartment of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Aria Baghai
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Daniel P. Raleigh
- Deartment of Chemistry, Stony Brook University, Nicolls Road, Stony Brook, New York 11790, United States
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
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11
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Smith AA, Moore KBE, Ambs PM, Saraswati AP, Fortin JS. Recent Advances in the Discovery of Therapeutics to Curtail Islet Amyloid Polypeptide Aggregation for Type 2 Diabetes Treatment. Adv Biol (Weinh) 2022; 6:e2101301. [PMID: 35931462 DOI: 10.1002/adbi.202101301] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 07/04/2022] [Indexed: 01/28/2023]
Abstract
In humans with type 2 diabetes, at least 70% of patients exhibit islet amyloid plaques formed by misfolding islet amyloid polypeptides (IAPP). The oligomeric conformation and accumulation of the IAPP plaques lead to a panoply of cytotoxic effects on the islet β-cells. Currently, no marketed therapies for the prevention or elimination of these amyloid deposits exist, and therefore significant efforts are required to address this gap. To date, most of the experimental treatments are limited to only in vitro stages of testing. In general, the proposed therapeutics use various targeting strategies, such as binding to the N-terminal region of islet amyloid polypeptide on residues 1-19 or the hydrophobic region of IAPP. Other strategies include targeting the peptide self-assembly through π-stacking. These methods are realized by using several different families of compounds, four of which are highlighted in this review: naturally occurring products, small molecules, organometallic compounds, and nanoparticles. Each of these categories holds immense potential to optimize and develop inhibitor(s) of pancreatic amyloidosis in the near future.
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Affiliation(s)
- Alyssa A Smith
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Kendall B E Moore
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | | | - Akella Prasanth Saraswati
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - Jessica S Fortin
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
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12
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Dicke SS, Maj M, Fields CR, Zanni MT. Metastable intermediate during hIAPP aggregation catalyzed by membranes as detected with 2D IR spectroscopy. RSC Chem Biol 2022; 3:931-940. [PMID: 35866164 PMCID: PMC9257649 DOI: 10.1039/d2cb00028h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
The aggregation of human islet amyloid polypeptide (hIAPP) into amyloid fibrils involves formation of oligomeric intermediates that are thought to be the cytotoxic species responsible for β-cell dysfunction in type 2 diabetes. hIAPP oligomers permeating or disrupting the cellular membrane may be one mechanism of toxicity and so measuring the structural kinetics of aggregation in the presence of membranes is of much interest. In this study, we use 2D IR spectroscopy and 13C18O isotope labeling to study the secondary structure of the oligomeric intermediates formed in solution and in the presence of phospholipid vesicles at sites L12A13, L16V17, G24A25 and V32G33. Pairs of labels monitor the couplings between associated polypeptides and the dihedral angles between adjacent residues. In solution, the L12A13 residues form an oligomeric β-sheet in addition to an α-helix whereas with the phospholipid vesicles they are α-helical throughout the aggregation process. In both solution and with DOPC vesicles, L16V17 and V32G33 have disordered structures until fibrils are formed. Similarly, under both conditions, G24A25 exhibits 3-state kinetics, created by an oligomeric intermediate with a well-defined β-sheet structure. Amyloid fibril formation is often thought to involve intermediates with exceedingly low populations that are difficult to detect experimentally. These experiments establish that amyloid fibril formation of hIAPP when catalyzed by membranes includes a metastable intermediate and that this intermediate has a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution, thought to be the toxic species. 2D IR and 13C18O isotope labeling establish that amyloid formation of hIAPP catalyzed by membranes includes a metastable intermediate with a similar structure at G24A25 in the FGAIL region as the corresponding intermediate in solution.![]()
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Affiliation(s)
- Sidney S Dicke
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Michał Maj
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA .,Formally at Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Caitlyn R Fields
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
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13
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Roy M, Nath AK, Pal I, Dey SG. Second Sphere Interactions in Amyloidogenic Diseases. Chem Rev 2022; 122:12132-12206. [PMID: 35471949 DOI: 10.1021/acs.chemrev.1c00941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloids are protein aggregates bearing a highly ordered cross β structural motif, which may be functional but are mostly pathogenic. Their formation, deposition in tissues and consequent organ dysfunction is the central event in amyloidogenic diseases. Such protein aggregation may be brought about by conformational changes, and much attention has been directed toward factors like metal binding, post-translational modifications, mutations of protein etc., which eventually affect the reactivity and cytotoxicity of the associated proteins. Over the past decade, a global effort from different groups working on these misfolded/unfolded proteins/peptides has revealed that the amino acid residues in the second coordination sphere of the active sites of amyloidogenic proteins/peptides cause changes in H-bonding pattern or protein-protein interactions, which dramatically alter the structure and reactivity of these proteins/peptides. These second sphere effects not only determine the binding of transition metals and cofactors, which define the pathology of some of these diseases, but also change the mechanism of redox reactions catalyzed by these proteins/peptides and form the basis of oxidative damage associated with these amyloidogenic diseases. The present review seeks to discuss such second sphere modifications and their ramifications in the etiopathology of some representative amyloidogenic diseases like Alzheimer's disease (AD), type 2 diabetes mellitus (T2Dm), Parkinson's disease (PD), Huntington's disease (HD), and prion diseases.
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Affiliation(s)
- Madhuparna Roy
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Arnab Kumar Nath
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Ishita Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Somdatta Ghosh Dey
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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14
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Mediators of Amylin Action in Metabolic Control. J Clin Med 2022; 11:jcm11082207. [PMID: 35456307 PMCID: PMC9025724 DOI: 10.3390/jcm11082207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/08/2022] [Accepted: 04/13/2022] [Indexed: 02/06/2023] Open
Abstract
Amylin (also called islet amyloid polypeptide (IAPP)) is a pancreatic beta-cell hormone that is co-secreted with insulin in response to nutrient stimuli. The last 35 years of intensive research have shown that amylin exerts important physiological effects on metabolic control. Most importantly, amylin is a physiological control of meal-ending satiation, and it limits the rate of gastric emptying and reduces the secretion of pancreatic glucagon, in particular in postprandial states. The physiological effects of amylin and its analogs are mediated by direct brain activation, with the caudal hindbrain playing the most prominent role. The clarification of the structure of amylin receptors, consisting of the calcitonin core receptor plus receptor-activity modifying proteins, aided in the development of amylin analogs with a broad pharmacological profile. The general interest in amylin physiology and pharmacology was boosted by the finding that amylin is a sensitizer to the catabolic actions of leptin. Today, amylin derived analogs are considered to be among the most promising approaches for the pharmacotherapy against obesity. At least in conjunction with insulin, amylin analogs are also considered important treatment options in diabetic patients, so that new drugs may soon be added to the only currently approved compound pramlintide (Symlin®). This review provides a brief summary of the physiology of amylin’s mode of actions and its role in the control of the metabolism, in particular energy intake and glucose metabolism.
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15
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Behl T, Arora A, Sehgal A, Singh S, Sharma N, Bhatia S, Al-Harrasi A, Bungau S, Mostafavi E. Molecular and Biochemical Pathways Encompassing Diabetes Mellitus and Dementia. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:542-556. [PMID: 34758720 DOI: 10.2174/1871527320666211110115257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/25/2021] [Accepted: 09/15/2021] [Indexed: 11/22/2022]
Abstract
Diabetes mellitus is a major metabolic disorder that has now emerged as an epidemic, and it affects the brain through an array of pathways. Diabetes mellitus patients can develop pathological changes in the brain, which eventually take the shape of mild cognitive impairment progressing to Alzheimer's Disease. A number of preclinical and clinical studies demonstrate this fact, and it comes out to be those molecular pathways such as amyloidogenesis, oxidative stress, inflammation, and impaired insulin signaling are identical in diabetes mellitus and dementia. However, the critical player involved in the vicious cycle of diabetes mellitus and dementia is insulin, whose signaling, when impaired in diabetes mellitus (both type 1 and 2), leads to a decline in cognition, although other pathways are also essential contributors. Moreover, it is not only that diabetes mellitus patients indicate cognitive decline at a later stage; many Alzheimer's Disease patients also reflect symptoms of diabetes mellitus, thus creating a vicious cycle inculcating a web of complex molecular mechanisms and hence categorizing Alzheimer's Disease as 'brain diabetes'. Thus, it is practical to suggest that anti-diabetic drugs are beneficial in Alzheimer's Disease; but only smaller trials, not the larger ones, have showcased positive outcomes mainly because of the late onset of therapy. Therefore, it is extremely important to develop more of such molecules that target insulin in dementia patients along with such methods that diagnose impaired insulin signaling and the associated cognitive decline so that early therapy may be initiated and the progression of the disease be prevented.
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Affiliation(s)
- Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Arpita Arora
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Neelam Sharma
- Chitkara College of Pharmacy, Chitkara University, Punjab. India
| | - Saurabh Bhatia
- Amity Institute of Pharmacy, Amity University, Haryana. India
| | - Ahmed Al-Harrasi
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa. Oman
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Oradea. Romania
| | - Ebrahim Mostafavi
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA. United States
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16
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Marmentini C, Branco RCS, Boschero AC, Kurauti MA. Islet amyloid toxicity: From genesis to counteracting mechanisms. J Cell Physiol 2021; 237:1119-1142. [PMID: 34636428 DOI: 10.1002/jcp.30600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 09/09/2021] [Accepted: 10/01/2021] [Indexed: 11/11/2022]
Abstract
Islet amyloid polypeptide (IAPP or amylin) is a hormone co-secreted with insulin by pancreatic β-cells and is the major component of islet amyloid. Islet amyloid is found in the pancreas of patients with type 2 diabetes (T2D) and may be involved in β-cell dysfunction and death, observed in this disease. Thus, investigating the aspects related to amyloid formation is relevant to the development of strategies towards β-cell protection. In this sense, IAPP misprocessing, IAPP overproduction, and disturbances in intra- and extracellular environments seem to be decisive for IAPP to form islet amyloid. Islet amyloid toxicity in β-cells may be triggered in intra- and/or extracellular sites by membrane damage, endoplasmic reticulum stress, autophagy disruption, mitochondrial dysfunction, inflammation, and apoptosis. Importantly, different approaches have been suggested to prevent islet amyloid cytotoxicity, from inhibition of IAPP aggregation to attenuation of cell death mechanisms. Such approaches have improved β-cell function and prevented the development of hyperglycemia in animals. Therefore, counteracting islet amyloid may be a promising therapy for T2D treatment.
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Affiliation(s)
- Carine Marmentini
- Laboratory of Endocrine Pancreas and Metabolism, Obesity and Comorbidities Research Center (OCRC), University of Campinas (UNICAMP), Campinas, Brazil
| | - Renato C S Branco
- Laboratory of Endocrine Pancreas and Metabolism, Obesity and Comorbidities Research Center (OCRC), University of Campinas (UNICAMP), Campinas, Brazil
| | - Antonio C Boschero
- Laboratory of Endocrine Pancreas and Metabolism, Obesity and Comorbidities Research Center (OCRC), University of Campinas (UNICAMP), Campinas, Brazil
| | - Mirian A Kurauti
- Laboratory of Endocrine Pancreas and Metabolism, Obesity and Comorbidities Research Center (OCRC), University of Campinas (UNICAMP), Campinas, Brazil.,Department of Physiological Sciences, Biological Sciences Center, State University of Maringa (UEM), Maringa, Brazil
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17
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Khemtemourian L, Antoniciello F, Sahoo BR, Decossas M, Lecomte S, Ramamoorthy A. Investigation of the effects of two major secretory granules components, insulin and zinc, on human-IAPP amyloid aggregation and membrane damage. Chem Phys Lipids 2021; 237:105083. [PMID: 33887213 DOI: 10.1016/j.chemphyslip.2021.105083] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/11/2021] [Accepted: 04/07/2021] [Indexed: 02/06/2023]
Abstract
Human islet amyloid polypeptide (hIAPP) is a highly amyloidogenic peptide found in pancreatic islets of type-2 diabetes (T2D) patients. Under certain conditions, hIAPP is able to form amyloid fibrils that play a role in the progression of T2D. hIAPP is synthesized in the β-cell of the pancreas and stored in the secretory granules before being released into the extracellular compartment. It has been suggested that natural stabilizing agents, such as insulin or zinc present in the secretory granules with hIAPP could prevent hIAPP fibril formation. The difference in the amino acid sequences of IAPP among species strongly correlates with amyloidogenicity and toxicity. The residue histidine at position 18 is known to be important in modulating the fibril formation, membrane leakage and toxicity. In this study, we have synthesized four analogues of hIAPP (H18R-IAPP, H18K-IAPP, H18A-IAPP and H18E-IAPP) and characterized their aggregation with either insulin or zinc in order to determine the effect of the residue-18 on the insulin-IAPP and zinc-IAPP interactions using a variety of biophysical experiments including thioflavin-T fluorescence, transmission electron microscopy imaging, circular dichroism, and NMR spectroscopy. We show that insulin reduced hIAPP fibril formation both in solution and in the presence of membrane and hIAPP-membrane damage and that the interactions are somewhat mediated by the residue-18. In addition, our results reveal that zinc affects the process of hIAPP fibril formation in solution but not in the presence of membrane. Our results indicate that the nature of the residue-18 is important for zinc binding. Based on this observation, we hypothesize that zinc binds to the residues in the N-terminal region of hIAPP, which is not accessible in the presence of membrane due to its strong interaction with lipids.
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Affiliation(s)
| | | | - Bikash R Sahoo
- Biophysics Program, Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Marion Decossas
- CBMN, CNRS UMR 5248, IPB, Univ. Bordeaux, F-33600 Pessac, France
| | - Sophie Lecomte
- CBMN, CNRS UMR 5248, IPB, Univ. Bordeaux, F-33600 Pessac, France
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, MI 48109-1055, USA.
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18
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Chowdhary S, Moschner J, Mikolajczak DJ, Becker M, Thünemann AF, Kästner C, Klemczak D, Stegemann A, Böttcher C, Metrangolo P, Netz RR, Koksch B. The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation. Chembiochem 2020; 21:3544-3554. [PMID: 33405360 PMCID: PMC7756607 DOI: 10.1002/cbic.202000373] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/31/2020] [Indexed: 12/12/2022]
Abstract
The hexapeptide hIAPP22-27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild-type hIAPP's toxicity to β-cell death. In amyloid research, the role of hydrophobic and aromatic-aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic-aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) to study the impact of side-chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self-assembly process.
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Affiliation(s)
- Suvrat Chowdhary
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Johann Moschner
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Dorian J. Mikolajczak
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Maximilian Becker
- Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Andreas F. Thünemann
- Federal Institute for Materials Research and Testing (BAM)Unter den Eichen 8712205BerlinGermany
| | - Claudia Kästner
- Federal Institute for Materials Research and Testing (BAM)Unter den Eichen 8712205BerlinGermany
| | - Damian Klemczak
- Institute of PharmacyFreie Universität BerlinKönigin-Luise-Str. 2–414195BerlinGermany
| | - Anne‐Katrin Stegemann
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
| | - Christoph Böttcher
- Institute of Chemistry and Biochemistry and Core Facility BioSupraMolFreie Universität BerlinFabeckstraße 36a14195BerlinGermany
| | - Pierangelo Metrangolo
- Department of ChemistryMaterials and Chemical Engineering “Giulio Natta”Politecnico di MilanoVia L. Mancinelli 720131MilanItaly
| | - Roland R. Netz
- Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Beate Koksch
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2014195BerlinGermany
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19
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Khan A, Nayeem SM. Effect of TMAO and Urea on Dimers and Tetramers of Amyloidogenic Heptapeptides ( 23FGAILSS 29). ACS OMEGA 2020; 5:26986-26998. [PMID: 33134659 PMCID: PMC7593999 DOI: 10.1021/acsomega.0c01031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/08/2020] [Indexed: 06/11/2023]
Abstract
Human islet amyloid polypeptide (hIAPP) (1-37) is an intrinsically disordered protein that is released with insulin by β-cells found in the pancreas. Under certain environmental conditions, hIAPP can aggregate, which leads to β-cell death. FGAILSS (23-29) residues of the hIAPP protein form β sheets, which may be toxic species in type 2 diabetes (T2D) patients. All-atom molecular dynamics (MD) simulations have been used to analyze the effect of two distinct types of osmolytes trimethylamine N-oxide (TMAO) and urea on two and four FGAILSS heptapeptides. TMAO leads the individual peptide toward an extended conformation with a higher radius of gyration and favors the formation of antiparallel β-sheets with an increase in its concentration. However, urea mostly shows compaction of individual peptides except at 4.0 M in the case of a tetramer but does not show aggregation behavior as a whole. TMAO leads both the dimer and tetramer toward the native state with an increase in its concentration. Moreover, both the dimer and tetramer show irregular behavior in urea. The tetramer in 4.0 M urea shows the maximum fraction of native contacts due to the formation of antiparallel β-sheets. This formation of antiparallel β-sheets favors the aggregation of peptides. TMAO forms a smaller number of hydrogen bonds with peptides as compared to urea as the exclusion of TMAO and accumulation of urea around the peptides have occurred in the first solvation shell (FSS). Principal component analysis (PCA) results suggest that the minima in the free energy landscape (FEL) plot are homogeneous for a particular conformation in TMAO with smaller basins, while in urea, the dimer shows minima mostly for extended conformations. For a 4.0 M urea concentration, the tetramer shows the minimum for antiparallel β-sheets, which indicates the aggregation behavior of the tetramer, and for a higher concentration, it shows minima with wider basins of extended conformations.
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20
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Dec R, Dzwolak W. Extremely Amyloidogenic Single-Chain Analogues of Insulin's H-Fragment: Structural Adaptability of an Amyloid Stretch. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12150-12159. [PMID: 32988199 PMCID: PMC7586408 DOI: 10.1021/acs.langmuir.0c01747] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/25/2020] [Indexed: 06/11/2023]
Abstract
Relatively short amino acid sequences often play a pivotal role in triggering protein aggregation leading to the formation of amyloid fibrils. In the case of insulin, various regions of A- and B-chains have been implicated as the most relevant to the protein's amyloidogenicity. Here, we focus on the highly amyloidogenic H-fragment of insulin comprising the disulfide-bonded N-terminal parts of both chains. Analysis of the aggregation behavior of single-chain peptide derivatives of the H-fragment suggests that the A-chain's part initiates the aggregation process while the disulfide-tethered B-chain reluctantly adapts to amyloid structure. Merging of both A- and B-parts into single-chain continuous peptides (A-B and B-A) results in extreme amyloidogenicity exceeding that of the double-chain H-fragment as reflected by almost instantaneous de novo fibrillization. Amyloid fibrils of A-B and B-A present distinct morphological and infrared traits and do not cross-seed insulin. Our study suggests that the N-terminal part of insulin's A-chain containing the intact Cys6-Cys11 intrachain disulfide bond may constitute insulin's major amyloid stretch which, through its bent conformation, enforces a parallel in-register alignment of β-strands. Comparison of the self-association behavior of H, A-B, and B-A peptides suggests that A-chain's N-terminal amyloid stretch is very versatile and adaptive to various structural contexts.
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21
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Röder C, Kupreichyk T, Gremer L, Schäfer LU, Pothula KR, Ravelli RBG, Willbold D, Hoyer W, Schröder GF. Cryo-EM structure of islet amyloid polypeptide fibrils reveals similarities with amyloid-β fibrils. Nat Struct Mol Biol 2020; 27:660-667. [PMID: 32541895 DOI: 10.1101/2020.02.11.944546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/30/2020] [Indexed: 05/18/2023]
Abstract
Amyloid deposits consisting of fibrillar islet amyloid polypeptide (IAPP) in pancreatic islets are associated with beta-cell loss and have been implicated in type 2 diabetes (T2D). Here, we applied cryo-EM to reconstruct densities of three dominant IAPP fibril polymorphs, formed in vitro from synthetic human IAPP. An atomic model of the main polymorph, built from a density map of 4.2-Å resolution, reveals two S-shaped, intertwined protofilaments. The segment 21-NNFGAIL-27, essential for IAPP amyloidogenicity, forms the protofilament interface together with Tyr37 and the amidated C terminus. The S-fold resembles polymorphs of Alzheimer's disease (AD)-associated amyloid-β (Aβ) fibrils, which might account for the epidemiological link between T2D and AD and reports on IAPP-Aβ cross-seeding in vivo. The results structurally link the early-onset T2D IAPP genetic polymorphism (encoding Ser20Gly) with the AD Arctic mutation (Glu22Gly) of Aβ and support the design of inhibitors and imaging probes for IAPP fibrils.
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Affiliation(s)
- Christine Röder
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tatsiana Kupreichyk
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Lothar Gremer
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Luisa U Schäfer
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
| | - Karunakar R Pothula
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
| | - Raimond B G Ravelli
- The Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, the Netherlands
| | - Dieter Willbold
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Wolfgang Hoyer
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany.
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany.
- Institut für Physikalische Biologie, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
| | - Gunnar F Schröder
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany.
- Jülich Centre for Structural Biology (JuStruct), Forschungszentrum Jülich, Jülich, Germany.
- Physics Department, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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22
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Noh D, Bower RL, Hay DL, Zhyvoloup A, Raleigh DP. Analysis of Amylin Consensus Sequences Suggests That Human Amylin Is Not Optimized to Minimize Amyloid Formation and Provides Clues to Factors That Modulate Amyloidogenicity. ACS Chem Biol 2020; 15:1408-1416. [PMID: 32364695 DOI: 10.1021/acschembio.9b01050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The neuropancreatic polypeptide hormone amylin forms pancreatic islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell death in the disease and to the failure of islet transplants, but the features which influence amylin amyloidogenicity are not understood. We constructed an amino acid sequence alignment of 202 sequences of amylin and used the alignment to design consensus sequences of vertebrate amylins, mammalian amylins, and primate amylins. Amylin is highly conserved, but there are differences between human amylin and each consensus sequence, ranging from one to six substitutions. Biophysical analysis shows that all of the consensus sequences form amyloid but do so more slowly than human amylin in vitro. The rate of amyloid formation by the primate consensus sequence is 3- to 4-fold slower than human amylin; the mammalian consensus sequence is approximately 20- to 25-fold slower, and the vertebrate consensus sequence is approximately 6-fold slower. All of the consensus sequences are moderately less toxic than human amylin toward a cultured β-cell line, with the vertebrate consensus sequence displaying the largest reduction in toxicity of 3- to 4-fold. All of the consensus sequences activate a human amylin receptor and exhibit only modest reductions in activity, ranging from 3- to 4-fold as judged by a cAMP production assay. The analysis argues that there is no strong selective evolutionary pressure to avoid the formation of islet amyloid and provides information relevant to the design of less amyloidogenic amylin variants.
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Affiliation(s)
- Daeun Noh
- Graduate Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York 11790, United States
| | - Rebekah L. Bower
- School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1142, New Zealand
| | - Debbie L. Hay
- School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1142, New Zealand
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT United Kingdom
| | - Daniel P. Raleigh
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT United Kingdom
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11790, United States
- Laufer Center for Quantitative Biology, Stony Brook University, Stony Brook, New York 11790, United States
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23
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Cao Q, Boyer DR, Sawaya MR, Ge P, Eisenberg DS. Cryo-EM structure and inhibitor design of human IAPP (amylin) fibrils. Nat Struct Mol Biol 2020; 27:653-659. [PMID: 32541896 PMCID: PMC8579859 DOI: 10.1038/s41594-020-0435-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/13/2020] [Indexed: 12/21/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) functions as a glucose-regulating hormone but deposits as amyloid fibrils in more than 90% of patients with type II diabetes (T2D). Here we report the cryo-EM structure of recombinant full-length hIAPP fibrils. The fibril is composed of two symmetrically related protofilaments with ordered residues 14-37. Our hIAPP fibril structure (i) supports the previous hypothesis that residues 20-29 constitute the core of the hIAPP amyloid; (ii) suggests a molecular mechanism for the action of the hIAPP hereditary mutation S20G; (iii) explains why the six residue substitutions in rodent IAPP prevent aggregation; and (iv) suggests regions responsible for the observed hIAPP cross-seeding with β-amyloid. Furthermore, we performed structure-based inhibitor design to generate potential hIAPP aggregation inhibitors. Four of the designed peptides delay hIAPP aggregation in vitro, providing a starting point for the development of T2D therapeutics and proof of concept that the capping strategy can be used on full-length cryo-EM fibril structures.
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Affiliation(s)
- Qin Cao
- Department of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute, Molecular Biology Institute, and Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - David R Boyer
- Department of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute, Molecular Biology Institute, and Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Michael R Sawaya
- Department of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute, Molecular Biology Institute, and Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peng Ge
- California NanoSystem Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - David S Eisenberg
- Department of Chemistry and Biochemistry and Biological Chemistry, UCLA-DOE Institute, Molecular Biology Institute, and Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, USA.
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24
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Cryo-EM structure of islet amyloid polypeptide fibrils reveals similarities with amyloid-β fibrils. Nat Struct Mol Biol 2020; 27:660-667. [PMID: 32541895 DOI: 10.1038/s41594-020-0442-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/30/2020] [Indexed: 01/09/2023]
Abstract
Amyloid deposits consisting of fibrillar islet amyloid polypeptide (IAPP) in pancreatic islets are associated with beta-cell loss and have been implicated in type 2 diabetes (T2D). Here, we applied cryo-EM to reconstruct densities of three dominant IAPP fibril polymorphs, formed in vitro from synthetic human IAPP. An atomic model of the main polymorph, built from a density map of 4.2-Å resolution, reveals two S-shaped, intertwined protofilaments. The segment 21-NNFGAIL-27, essential for IAPP amyloidogenicity, forms the protofilament interface together with Tyr37 and the amidated C terminus. The S-fold resembles polymorphs of Alzheimer's disease (AD)-associated amyloid-β (Aβ) fibrils, which might account for the epidemiological link between T2D and AD and reports on IAPP-Aβ cross-seeding in vivo. The results structurally link the early-onset T2D IAPP genetic polymorphism (encoding Ser20Gly) with the AD Arctic mutation (Glu22Gly) of Aβ and support the design of inhibitors and imaging probes for IAPP fibrils.
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25
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Zhang N, Xing Y, Yu Y, Liu C, Jin B, Huo L, Kong D, Yang Z, Zhang X, Zheng R, Jia Z, Kang L, Zhang W. Influence of human amylin on the membrane stability of rat primary hippocampal neurons. Aging (Albany NY) 2020; 12:8923-8938. [PMID: 32463790 PMCID: PMC7288967 DOI: 10.18632/aging.103105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/09/2020] [Indexed: 04/09/2023]
Abstract
The two most common aging-related diseases, Alzheimer's disease and type 2 diabetes mellitus, are associated with accumulation of amyloid proteins (β-amyloid and amylin, respectively). This amylin aggregation is reportedly cytotoxic to neurons. We found that aggregation of human amylin (hAmylin) induced neuronal apoptosis without obvious microglial infiltration in vivo. High concentrations of hAmylin irreversibly aggregated on the surface of the neuronal plasma membrane. Long-term incubation with hAmylin induced morphological changes in neurons. Moreover, hAmylin permeabilized the neuronal membrane within 1 min in a manner similar to Triton X-100, allowing impermeable fluorescent antibodies to enter the neurons and stain intracellular antigens. hAmylin also permeabilized the cell membrane of astrocytes, though more slowly. Under scanning electron microscopy, we observed that hAmylin destroyed the integrity of the cell membranes of both neurons and astrocytes. Additionally, it increased intracellular reactive oxygen species generation and reduced the mitochondrial membrane potential. Thus, by aggregating on the surface of neurons, hAmylin impaired the cell membrane integrity, induced reactive oxygen species production, reduced the mitochondrial membrane potential, and ultimately induced neuronal apoptosis.
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Affiliation(s)
- Nan Zhang
- Central Laboratory, First Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei International Joint Research Center for Brain Science, Shijiazhuang, Hebei, China
| | - Yuan Xing
- Department of Neurology, First Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
- Brain Aging and Cognitive Neuroscience Key Laboratory of Hebei Province, Shijiazhuang, Hebei, China
| | - Yongzhou Yu
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Chao Liu
- Department of Laboratory Animal Science, Hebei Medical University, Hebei Key Lab of Laboratory Animal Science, Shijiazhuang, Hebei, China
| | - Baohua Jin
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lifang Huo
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Dezhi Kong
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Zuxiao Yang
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiangjian Zhang
- Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio-Cerebrovascular Disease, Department of Neurology, Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Ruimao Zheng
- Department of Anatomy, Histology and Embryology, Health Science Center, Neuroscience Research Institute, Key Laboratory for Neuroscience of the Ministry of Education, Key Laboratory for Neuroscience of the National Health Commission, Peking University, Beijing, China
| | - Zhanfeng Jia
- Department of Pharmacology, The Key Laboratory of New Drug Pharmacology and Toxicology, Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, The Key Laboratory of Neural and Vascular Biology Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lin Kang
- Department of Endocrinology, The Second Clinical Medical College of Jinan University, Shenzhen People’s Hospital, Clinical Medical Research Center, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Wei Zhang
- Department of Pharmacology, Institution of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
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Lee KH, Zhyvoloup A, Raleigh D. Amyloidogenicity and cytotoxicity of des-Lys-1 human amylin provides insight into amylin self-assembly and highlights the difficulties of defining amyloidogenicity. Protein Eng Des Sel 2020; 32:87-93. [PMID: 31768548 DOI: 10.1093/protein/gzz036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/11/2019] [Accepted: 07/31/2019] [Indexed: 12/27/2022] Open
Abstract
The polypeptide amylin is responsible for islet amyloid in type 2 diabetes, a process which contributes to β-cell death in the disease. The role of the N-terminal region of amylin in amyloid formation is relatively unexplored, although removal of the disulfide bridged loop between Cys-2 and Cys-7 accelerates amyloid formation. We examine the des Lys-1 variant of human amylin (h-amylin), a variant which is likely produced in vivo. Lys-1 is a region of high charge density in the h-amylin amyloid fiber. The des Lys-1 polypeptide forms amyloid on the same time scale as wild-type amylin in phosphate buffered saline, but does so more rapidly in Tris. The des Lys-1 variant is somewhat less toxic to cultured INS cells than wild type. The implications for the in vitro mechanism of amyloid formation and for comparative analysis of amyloidogenicity are discussed.
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Affiliation(s)
- Kyung-Hoon Lee
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11790-3400, USA
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E6BT, UK, and
| | - Daniel Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11790-3400, USA.,Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E6BT, UK, and.,Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11790-3400, USA
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27
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Ridgway Z, Eldrid C, Zhyvoloup A, Ben-Younis A, Noh D, Thalassinos K, Raleigh DP. Analysis of Proline Substitutions Reveals the Plasticity and Sequence Sensitivity of Human IAPP Amyloidogenicity and Toxicity. Biochemistry 2020; 59:742-754. [PMID: 31922743 DOI: 10.1021/acs.biochem.9b01109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pancreatic amyloid formation by the polypeptide IAPP contributes to β-cell dysfunction in type 2 diabetes. There is a 1:1 correspondence between the ability of IAPP from different species to form amyloid in vitro and the susceptibility of the organism to develop diabetes. Rat IAPP is non-amyloidogenic and differs from human IAPP at six positions, including three proline replacements: A25P, S28P, and S29P. Incorporation of these proline residues into human IAPP leads to a non-amyloidogenic analogue that is used clinically. The role of the individual proline residues is not understood. We examine the three single and three double proline substitutions in the context of human IAPP. An S28P substitution significantly decreases amyloidogenicity and toxicity, while an S29P substitution has very modest effects despite being an identical replacement just one residue away. The consequences of the A25P substitution are between those of the two Ser to Pro substitutions. Double analogues containing an S28P replacement are less amyloidogenic and less toxic than the IAPPA25P S29P double analogue. Ion mobility mass spectrometry reveals that there is no correlation between the monomer or dimer conformation as reported by collision cross section measurements and the time to form amyloid. The work reveals both the plasticity of IAPP amyloid formation and the exquisite sequence sensitivity of IAPP amyloidogenicity and toxicity. The study highlights the key role of the S28P substitution and provides information that will aid in the rational design of soluble variants of IAPP. The variants studied here offer a system for further exploring features that control IAPP toxicity.
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Affiliation(s)
- Zachary Ridgway
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Charles Eldrid
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Aisha Ben-Younis
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Daeun Noh
- Graduate Program in Biochemistry and Structural Biology , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
| | - Daniel P Raleigh
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States.,Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E 6BT , U.K
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28
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Ridgway Z, Lee KH, Zhyvoloup A, Wong A, Eldrid C, Hannaberry E, Thalassinos K, Abedini A, Raleigh DP. Analysis of Baboon IAPP Provides Insight into Amyloidogenicity and Cytotoxicity of Human IAPP. Biophys J 2020; 118:1142-1151. [PMID: 32105649 DOI: 10.1016/j.bpj.2019.12.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 12/25/2022] Open
Abstract
The polypeptide hormone islet amyloid polypeptide (IAPP) forms islet amyloid in type 2 diabetes, a process which contributes to pancreatic β-cell dysfunction and death. Not all species form islet amyloid, and the ability to do so correlates with the primary sequence. Humans form islet amyloid, but baboon IAPP has not been studied. The baboon peptide differs from human IAPP at three positions containing K1I, H18R, and A25T substitutions. The K1I substitution is a rare example of a replacement in the N-terminal region of amylin. The effect of this mutation on amyloid formation has not been studied, but it reduces the net charge, and amyloid prediction programs suggest that it should increase amyloidogenicity. The A25T replacement involves a nonconservative substitution in a region of IAPP that is believed to be important for aggregation, but the effects of this replacement have not been examined. The H18R point mutant has been previously shown to reduce aggregation in vitro. Baboon amylin forms amyloid on the same timescale as human amylin in vitro and exhibits similar toxicity toward cultured β-cells. The K1I replacement in human amylin slightly reduces toxicity, whereas the A25T substitution accelerates amyloid formation and enhances toxicity. Photochemical cross-linking reveals that the baboon amylin, like human amylin, forms low-order oligomers in the lag phase of amyloid formation. Ion-mobility mass spectrometry reveals broadly similar gas phase collisional cross sections for human and baboon amylin monomers and dimers, with some differences in the arrival time distributions. Preamyloid oligomers formed by baboon amylin, but not baboon amylin fibers, are toxic to cultured β-cells. The toxicity of baboon oligomers and lack of significantly detectable toxicity with exogenously added amyloid fibers is consistent with the hypothesis that preamyloid oligomers are the most toxic species produced during IAPP amyloid formation.
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Affiliation(s)
- Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, New York
| | - Kyung-Hoon Lee
- Department of Biology, Chowan University, Murfreesboro, North Carolina
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Amy Wong
- Department of Chemistry, Stony Brook University, Stony Brook, New York
| | - Charles Eldrid
- Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Eleni Hannaberry
- Department of Chemistry, Stony Brook University, Stony Brook, New York
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Andisheh Abedini
- Department of Chemistry, Stony Brook University, Stony Brook, New York.
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, New York; Institute of Structural and Molecular Biology, University College London, London, United Kingdom.
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29
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Lee KH, Noh D, Zhyvoloup A, Raleigh D. Analysis of Prairie Vole Amylin Reveals the Importance of the N-Terminus and Residue 22 in Amyloidogenicity and Cytotoxicity. Biochemistry 2019; 59:471-478. [PMID: 31777253 DOI: 10.1021/acs.biochem.9b00952] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amyloid formation by amylin contributes to β-cell dysfunction in type 2 diabetes. The features that control the amyloidogenicity and toxicity of amylin are not understood. Not all species form islet amyloid, and its presence or absence correlates with the in vitro behavior of the polypeptide. Rats do not develop type 2 diabetes or islet amyloid, and rat amylin is non-amyloidogenic, except at very high concentrations. This has led to the notion that rodent amylins are non-amyloidogenic. Prairie vole amylin has an unusual sequence compared to those of human and rat amylin, including nonconservative Lys-1 to Glu and Asn-22 to Gly substitutions. The first reduces the net charge on the peptide, while the second disrupts a potential network of side chain hydrogen bonds in the amyloid fiber, a so-called Asn ladder. The prairie vole polypeptide forms amyloid more slowly than human amylin and is considerably less cytotoxic. An Asn-22 to Gly substitution in human amylin significantly reduces toxicity, increasing the effective concentration of amylin required to reach 50% toxicity by >7-fold, but has modest effects on the time to form amyloid. A Lys-1 to Glu replacement has a weaker effect but does reduce toxicity relative to that of human amylin, without having a significant impact on the time to form amyloid. The effect of the Lys-1 to Glu substitution on amyloid kinetics is more significant in Tris buffer than in phosphate-buffered saline. This work demonstrates that the N-terminus of amylin plays a role in modulating toxicity and highlights the key role of position 22.
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Affiliation(s)
- Kyung-Hoon Lee
- Department of Biology , Chowan University , One University Place , Murfreesboro , North Carolina 27855 , United States
| | - Daeun Noh
- Graduate Program in Biochemistry and Structural Biology , Stony Brook University , Stony Brook , New York 11790 , United States
| | - Alexander Zhyvoloup
- Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E6BT , United Kingdom
| | - Daniel Raleigh
- Graduate Program in Biochemistry and Structural Biology , Stony Brook University , Stony Brook , New York 11790 , United States.,Institute of Structural and Molecular Biology , University College London , Gower Street , London WC1E6BT , United Kingdom.,Department of Chemistry , Stony Brook University , Stony Brook , New York 11790-3400 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11790 , United States
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30
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Kumar AP, Lee S, Lukman S. Computational and Experimental Approaches to Design Inhibitors of Amylin Aggregation. Curr Drug Targets 2019; 20:1680-1694. [DOI: 10.2174/1389450120666190719164316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 01/21/2023]
Abstract
Amylin is a neuroendocrine peptide hormone secreted by pancreatic ß-cells; however,
amylin is toxic to ß-cells when it is aggregated in type 2 diabetes mellitus (T2DM). It is important to
understand amylin’s structures and aggregation mechanism for the discovery and design of effective
drugs to inhibit amylin aggregation. In this review, we investigated experimental and computational
studies on amylin structures and inhibitors. Our review provides some novel insights into amylin, particularly
for the design of its aggregation inhibitors to treat T2DM. We detailed the potential inhibitors
that have been studied hitherto and highlighted the neglected need to consider different amylin attributes
that depend on the presence/absence of physiologically relevant conditions, such as membranes.
These conditions and the experimental methods can greatly influence the results of studies on amylininhibitor
complexes. Text-mining over 3,000 amylin-related PubMed abstracts suggests the combined
therapeutic potential of amylin with leptin and glucagon-like peptide-1, which are two key hormones
in obesity. The results also suggest that targeting amylin aggregation can contribute to therapeutic efforts
for Alzheimer’s disease (AD). Therefore, we have also reviewed the role of amylin in other conditions
including obesity and AD. Finally, we provided insights for designing inhibitors of different
types (small molecules, proteins, peptides/mimetics, metal ions) to inhibit amylin aggregation.
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Affiliation(s)
- Ammu Prasanna Kumar
- Department of Chemistry, College of Arts and Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Sungmun Lee
- Department of Biomedical Engineering and Healthcare Engineering Innovation Center, College of Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Suryani Lukman
- Department of Chemistry, College of Arts and Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
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31
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Atrián-Blasco E, Gonzalez P, Santoro A, Alies B, Faller P, Hureau C. Cu and Zn coordination to amyloid peptides: From fascinating chemistry to debated pathological relevance. Coord Chem Rev 2018; 375:38-55. [PMID: 30262932 DOI: 10.1016/j.ccr.2018.04.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Several diseases share misfolding of different peptides and proteins as a key feature for their development. This is the case of important neurodegenerative diseases such as Alzheimer's and Parkinson's diseases and type II diabetes mellitus. Even more, metal ions such as copper and zinc might play an important role upon interaction with amyloidogenic peptides and proteins, which could impact their aggregation and toxicity abilities. In this review, the different coordination modes proposed for copper and zinc with amyloid-β, α-synuclein and IAPP will be reviewed as well as their impact on the aggregation, and ROS production in the case of copper. In addition, a special focus will be given to the mutations that affect metal binding and lead to familial cases of the diseases. Different modifications of the peptides that have been observed in vivo and could be relevant for the coordination of metal ions are also described.
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Affiliation(s)
- Elena Atrián-Blasco
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
| | - Paulina Gonzalez
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Alice Santoro
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Bruno Alies
- Université de Bordeaux, ChemBioPharm INSERM U1212 CNRS UMR 5320, Bordeaux, France
| | - Peter Faller
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Christelle Hureau
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
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32
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IAPP in type II diabetes: Basic research on structure, molecular interactions, and disease mechanisms suggests potential intervention strategies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.02.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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33
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Kiriyama Y, Nochi H. Role and Cytotoxicity of Amylin and Protection of Pancreatic Islet β-Cells from Amylin Cytotoxicity. Cells 2018; 7:cells7080095. [PMID: 30082607 PMCID: PMC6115925 DOI: 10.3390/cells7080095] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/28/2018] [Accepted: 08/01/2018] [Indexed: 12/26/2022] Open
Abstract
Amylin, (or islet amyloid polypeptide; IAPP), a 37-amino acid peptide hormone, is released in response to nutrients, including glucose, lipids or amino acids. Amylin is co-stored and co-secreted with insulin by pancreatic islet β-cells. Amylin inhibits food intake, delays gastric emptying, and decreases blood glucose levels, leading to the reduction of body weight. Therefore, amylin as well as insulin play important roles in controlling the level of blood glucose. However, human amylin aggregates and human amylin oligomers cause membrane disruption, endoplasmic reticulum (ER) stress and mitochondrial damage. Since cytotoxicity of human amylin oligomers to pancreatic islet β-cells can lead to diabetes, the protection of pancreatic islet β cells from cytotoxic amylin is crucial. Human amylin oligomers also inhibit autophagy, although autophagy can function to remove amylin aggregates and damaged organelles. Small molecules, including β-sheet breaker peptides, chemical chaperones, and foldamers, inhibit and disaggregate amyloid formed by human amylin, suggesting the possible use of these small molecules in the treatment of diabetes. In this review, we summarize recent findings regarding the role and cytotoxicity of amylin and the protection of pancreatic islet β-cells from cytotoxicity of amylin.
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Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Kagawa, Sanuki 769-2193, Japan.
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Kagawa, Sanuki 769-2193, Japan.
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34
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Mietlicki-Baase EG. Amylin in Alzheimer's disease: Pathological peptide or potential treatment? Neuropharmacology 2018; 136:287-297. [PMID: 29233636 PMCID: PMC5994175 DOI: 10.1016/j.neuropharm.2017.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease for which we currently lack effective treatments or a cure. The pancreatic peptide hormone amylin has recently garnered interest as a potential pharmacological target for the treatment of AD. A number of studies have demonstrated that amylin and amylin analogs like the FDA-approved diabetes drug pramlintide can reduce amyloid burden in the brain and improve cognitive symptoms of AD. However, other data suggest that amylin may have pathological effects in AD due to its propensity to misfold and aggregate under certain conditions. Here, the literature supporting a beneficial versus harmful role of amylin in AD is reviewed. Additionally, several critical gaps in the literature are discussed, such as our limited understanding of the amylin system during aging and in disease states, as well as complexities of amylin receptor signaling and of changing pathophysiology during AD progression that might underlie the seemingly conflicting or contradictory results in the amylin/AD literature. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Elizabeth G Mietlicki-Baase
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, NY 14214, USA.
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35
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Mauvais-Jarvis F, Le May C, Tiano JP, Liu S, Kilic-Berkmen G, Kim JH. The Role of Estrogens in Pancreatic Islet Physiopathology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1043:385-399. [PMID: 29224104 DOI: 10.1007/978-3-319-70178-3_18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In rodent models of insulin-deficient diabetes, 17β-estradiol (E2) protects pancreatic insulin-producing β-cells against oxidative stress, amyloid polypeptide toxicity, gluco-lipotoxicity, and apoptosis. Three estrogen receptors (ERs)-ERα, ERβ, and the G protein-coupled ER (GPER)-have been identified in rodent and human β-cells. This chapter describes recent advances in our understanding of the role of ERs in islet β-cell function, nutrient homeostasis, survival from pro-apoptotic stimuli, and proliferation. We discuss why and how ERs represent potential therapeutic targets for the maintenance of functional β-cell mass.
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Affiliation(s)
- Franck Mauvais-Jarvis
- Department of Medicine, Section of Endocrinology and Metabolism, Tulane University Health Sciences Center, School of Medicine, New Orleans, LA, USA.
| | - Cedric Le May
- L'institut du Thorax, INSERM-CNRS, University of Nantes, Nantes, France
| | - Joseph P Tiano
- Diabetes, Endocrinology, and Obesity Branch, NIDDK, Bethesda, MD, USA
| | - Suhuan Liu
- Xiamen Diabetes Institute, the First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Gamze Kilic-Berkmen
- Department of Pediatric, Emory University School of Medicine, Atlanta, GA, USA
| | - Jun Ho Kim
- Department of Food and Biotechnology, Korea University, Sejong, South Korea
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Rawat A, Langen R, Varkey J. Membranes as modulators of amyloid protein misfolding and target of toxicity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1863-1875. [PMID: 29702073 DOI: 10.1016/j.bbamem.2018.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/19/2018] [Accepted: 04/19/2018] [Indexed: 12/15/2022]
Abstract
Abnormal protein aggregation is a hallmark of various human diseases. α-Synuclein, a protein implicated in Parkinson's disease, is found in aggregated form within Lewy bodies that are characteristically observed in the brains of PD patients. Similarly, deposits of aggregated human islet amyloid polypeptide (IAPP) are found in the pancreatic islets in individuals with type 2 diabetes mellitus. Significant number of studies have focused on how monomeric, disaggregated proteins transition into various amyloid structures leading to identification of a vast number of aggregation promoting molecules and processes over the years. Inasmuch as these factors likely enhance the formation of toxic, misfolded species, they might act as risk factors in disease. Cellular membranes, and particularly certain lipids, are considered to be among the major players for aggregation of α-synuclein and IAPP, and membranes might also be the target of toxicity. Past studies have utilized an array of biophysical tools, both in vitro and in vivo, to expound the membrane-mediated aggregation. Here, we focus on membrane interaction of α-synuclein and IAPP, and how various kinds of membranes catalyze or modulate the aggregation of these proteins and how, in turn, these proteins disrupt membrane integrity, both in vitro and in vivo. The membrane interaction and subsequent aggregation has been briefly contrasted to aggregation of α-synuclein and IAPP in solution. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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Affiliation(s)
- Anoop Rawat
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States
| | - Ralf Langen
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States.
| | - Jobin Varkey
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA 90033, United States.
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Serrano AL, Lomont JP, Tu LH, Raleigh DP, Zanni MT. A Free Energy Barrier Caused by the Refolding of an Oligomeric Intermediate Controls the Lag Time of Amyloid Formation by hIAPP. J Am Chem Soc 2017; 139:16748-16758. [PMID: 29072444 DOI: 10.1021/jacs.7b08830] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Transiently populated oligomers formed en route to amyloid fibrils may constitute the most toxic aggregates associated with many amyloid-associated diseases. Most nucleation theories used to describe amyloid aggregation predict low oligomer concentrations and do not take into account free energy costs that may be associated with structural rearrangements between the oligomer and fiber states. We have used isotope labeling and two-dimensional infrared spectroscopy to spectrally resolve an oligomeric intermediate during the aggregation of the human islet amyloid protein (hIAPP or amylin), the protein associated with type II diabetes. A structural rearrangement includes the F23G24A25I26L27 region of hIAPP, which starts from a random coil structure, evolves into ordered β-sheet oligomers containing at least 5 strands, and then partially disorders in the fibril structure. The supercritical concentration is measured to be between 150 and 250 μM, which is the thermodynamic parameter that sets the free energy of the oligomers. A 3-state kinetic model fits the experimental data, but only if it includes a concentration independent free energy barrier >3 kcal/mol that represents the free energy cost of refolding the oligomeric intermediate into the structure of the amyloid fibril; i.e., "oligomer activation" is required. The barrier creates a transition state in the free energy landscape that slows fibril formation and creates a stable population of oligomers during the lag phase, even at concentrations below the supercritical concentration. Largely missing in current kinetic models is a link between structure and kinetics. Our experiments and modeling provide evidence that protein structural rearrangements during aggregation impact the populations and kinetics of toxic oligomeric species.
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Affiliation(s)
- Arnaldo L Serrano
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Justin P Lomont
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Ling-Hsien Tu
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11790, United States
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11790, United States
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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Raleigh D, Zhang X, Hastoy B, Clark A. The β-cell assassin: IAPP cytotoxicity. J Mol Endocrinol 2017; 59:R121-R140. [PMID: 28811318 DOI: 10.1530/jme-17-0105] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 08/15/2017] [Indexed: 12/28/2022]
Abstract
Islet amyloid polypeptide (IAPP) forms cytotoxic oligomers and amyloid fibrils in islets in type 2 diabetes (T2DM). The causal factors for amyloid formation are largely unknown. Mechanisms of molecular folding and assembly of human IAPP (hIAPP) into β-sheets, oligomers and fibrils have been assessed by detailed biophysical studies of hIAPP and non-fibrillogenic, rodent IAPP (rIAPP); cytotoxicity is associated with the early phases (oligomers/multimers) of fibrillogenesis. Interaction with synthetic membranes promotes β-sheet assembly possibly via a transient α-helical molecular conformation. Cellular hIAPP cytotoxicity can be activated from intracellular or extracellular sites. In transgenic rodents overexpressing hIAPP, intracellular pro-apoptotic signals can be generated at different points in β-cell protein synthesis. Increased cellular trafficking of proIAPP, failure of the unfolded protein response (UPR) or excess trafficking of misfolded peptide via the degradation pathways can induce apoptosis; these data indicate that defects in intracellular handling of hIAPP can induce cytotoxicity. However, there is no evidence for IAPP overexpression in T2DM. Extracellular amyloidosis is directly related to the degree of β-cell apoptosis in islets in T2DM. IAPP fragments, fibrils and multimers interact with membranes causing disruption in vivo and in vitro These findings support a role for extracellular IAPP in β-sheet conformation in cytotoxicity. Inhibitors of fibrillogenesis are useful tools to determine the aberrant mechanisms that result in hIAPP molecular refolding and islet amyloidosis. However, currently, their role as therapeutic agents remains uncertain.
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Affiliation(s)
- Daniel Raleigh
- Department of ChemistryStony Brook University, Stony Brook, New York, USA
- Research Department of Structural and Molecule BiologyUniversity College London, London, UK
| | - Xiaoxue Zhang
- Department of ChemistryStony Brook University, Stony Brook, New York, USA
| | - Benoît Hastoy
- Oxford Centre for Diabetes Endocrinology and MetabolismUniversity of Oxford, Oxford, UK
| | - Anne Clark
- Oxford Centre for Diabetes Endocrinology and MetabolismUniversity of Oxford, Oxford, UK
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Patel P, Parmar K, Vyas VK, Patel D, Das M. Combined in silico approaches for the identification of novel inhibitors of human islet amyloid polypeptide (hIAPP) fibrillation. J Mol Graph Model 2017; 77:295-310. [PMID: 28917147 DOI: 10.1016/j.jmgm.2017.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/01/2017] [Accepted: 09/02/2017] [Indexed: 12/31/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is a natively unfolded polypeptide hormone of glucose metabolism, which is co-secreted with insulin by the β-cells of the pancreas. In patients with type 2 diabetes, IAPP forms amyloid fibrils because of diabetes-associated β-cells dysfunction and increasing fibrillation, in turn, lead to failure of secretory function of β-cells. This provides a target for the discovery of small organic molecules against protein aggregation diseases. However, the binding mechanism of these molecules with monomers, oligomers and fibrils to inhibit fibrillation is still an open question. In this work, ligand and structure-based in silico approaches were used to identify novel fibrillation inhibitors and/or fibril binding compounds. The best pharmacophore model was used as a 3D search query for virtual screening of a compound database to identify novel molecules having the potential to be therapeutic agents against protein aggregation diseases. Docking and molecular dynamics simulation studies were used to explore the interaction pattern and mechanism of the identified novel small molecules with predicted hIAPP structure, its aggregation prone conformation and fibril forming segments. We show that catechins with galloyl group and molecules having two to three planar apolar rings bind to hIAPP structures and fibril forming segments with greater affinity. The differences in binding affinities of different compounds against several fibril forming segments of the peptide suggest that a mixture of active compounds may be required for treatment of aggregation diseases.
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Affiliation(s)
- Palak Patel
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Krupali Parmar
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Vivek K Vyas
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India
| | - Dhaval Patel
- Institute of Advanced Research, Koba Institutional Area, Gandhinagar, Gujarat 382007, India
| | - Mili Das
- Institute of Science, Nirma University, Sarkhej-Gandhinagar Highway, Ahmedabad, Gujarat 382481, India.
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Akter R, Abedini A, Ridgway Z, Zhang X, Kleinberg J, Schmidt AM, Raleigh DP. Evolutionary Adaptation and Amyloid Formation: Does the Reduced Amyloidogenicity and Cytotoxicity of Ursine Amylin Contribute to the Metabolic Adaption of Bears and Polar Bears? Isr J Chem 2017; 57:750-761. [PMID: 29955200 PMCID: PMC6018008 DOI: 10.1002/ijch.201600081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Much of our knowledge of diabetes is derived from studies of rodent models. An alternative approach explores evolutionary solutions to physiological stress by studying organisms that face challenging metabolic environments. Polar bears eat an enormously lipid-rich diet without deleterious metabolic consequences. In contrast, transgenic rodents expressing the human neuropancreatic polypeptide hormone amylin develop hyperglycemia and extensive pancreatic islet amyloid when fed a high fat diet. The process of islet amyloid formation by human amylin contributes to β-cell dysfunction and loss of β-cell mass in type-2 diabetes. We show that ursine amylin is considerably less amyloidogenic and less toxic to β-cells than human amylin, consistent with the hypothesis that part of the adaptation of bears to metabolic challenges might include protection from islet amyloidosis-induced β-cell toxicity. Ursine and human amylin differ at four locations: H18R, S20G, F23L, and S29P. These are interesting from a biophysical perspective since the S20G mutation accelerates amyloid formation but the H18R slows it. An H18RS20G double mutant of human amylin behaves similarly to the H18R mutant, indicating that the substitution at position 18 dominates the S20G replacement. These data suggest one possible mechanism underpinning the protection of bears against metabolic challenges and provide insight into the design of soluble analogs of human amylin.
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Affiliation(s)
- Rehana Akter
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Andisheh Abedini
- Diabetes Research Program, NYU School of Medicine, 522 First Avenue, New York, NY 10016
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Xiaoxue Zhang
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Joel Kleinberg
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Ann Marie Schmidt
- Diabetes Research Program, NYU School of Medicine, 522 First Avenue, New York, NY 10016
| | - Daniel P. Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
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Tracking the amyloidogenic core of IAPP amyloid fibrils: Insights from micro-Raman spectroscopy. J Struct Biol 2017; 199:140-152. [PMID: 28602716 DOI: 10.1016/j.jsb.2017.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/19/2017] [Accepted: 06/03/2017] [Indexed: 12/14/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is the major protein component of extracellular amyloid deposits, located in the islets of Langerhans, a hallmark of type II diabetes. The underlying mechanisms of IAPP aggregation have not yet been clearly defined, although the highly amyloidogenic sequence of the protein has been extensively studied. Several segments have been highlighted as aggregation-prone regions (APRs), with much attention focused on the central 8-17 and 20-29 stretches. In this work, we employ micro-Raman spectroscopy to identify specific regions that are contributing to or are excluded from the amyloidogenic core of IAPP amyloid fibrils. Our results demonstrate that both the N-terminal region containing a conserved disulfide bond between Cys residues at positions 2 and 7, and the C-terminal region containing the only Tyr residue are excluded from the amyloid core. Finally, by performing detailed aggregation assays and molecular dynamics simulations on a number of IAPP variants, we demonstrate that point mutations within the central APRs contribute to the reduction of the overall amyloidogenic potential of the protein but do not completely abolish the formation of IAPP amyloid fibrils.
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42
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Mukherjee A, Soto C. Prion-Like Protein Aggregates and Type 2 Diabetes. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024315. [PMID: 28159831 DOI: 10.1101/cshperspect.a024315] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 2 diabetes (T2D) is a highly prevalent metabolic disease characterized by chronic insulin resistance and β-cell dysfunction and loss, leading to impaired insulin release and hyperglycemia. Although the mechanism responsible for β-cell dysfunction and death is not completely understood, recent findings suggest that the accumulation of misfolded aggregates of the islet amyloid polypeptide (IAPP) in the islets of Langerhans may play an important role in pancreatic damage. Misfolding and aggregation of diverse proteins and their accumulation as amyloid in different organs is the hallmark feature in a group of chronic, degenerative diseases termed protein misfolding disorders (PMDs). PMDs include highly prevalent human illnesses such as Alzheimer's and Parkinson's disease, as well as more than 25 rarer disorders. Among them, prion diseases are unique because the pathology can be transmitted by a proteinaceous infectious agent, termed a prion, which induces disease by propagating protein misfolding and aggregation. This phenomenon has a striking resemblance to the process of protein misfolding and aggregation in all of the PMDs, suggesting that misfolded aggregates have an intrinsic potential to be transmissible. Indeed, recent studies have shown that the pathological hallmarks of various PMDs can be induced in vivo under experimental conditions by inoculating tissue extracts containing protein aggregates into animal models. In this review, we describe our current understanding of the molecular mechanism underlying the prion-like transmission of protein aggregates and its possible role in T2D.
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Affiliation(s)
- Abhisek Mukherjee
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Health Science Center, McGovern Medical School, Houston, Texas 77030
| | - Claudio Soto
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Health Science Center, McGovern Medical School, Houston, Texas 77030
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43
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Zhang Y, Song W. Islet amyloid polypeptide: Another key molecule in Alzheimer's pathogenesis? Prog Neurobiol 2017; 153:100-120. [PMID: 28274676 DOI: 10.1016/j.pneurobio.2017.03.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 02/17/2017] [Accepted: 03/02/2017] [Indexed: 12/14/2022]
Abstract
Recent epidemiological evidence reveals that patients suffering from type 2 diabetes mellitus (T2DM) often experience a significant decline in cognitive function, and approximately 70% of those cases eventually develop Alzheimer's disease (AD). Although several pathological processes are shared by AD and T2DM, the exact molecular mechanisms connecting these two diseases are poorly understood. Aggregation of human islet amyloid polypeptide (hIAPP), the pathological hallmark of T2DM, has also been detected in brain tissue and is associated with cognitive decline and AD development. In addition, hIAPP and amyloid β protein (Aβ) share many biophysical and physiological properties as well as exert similar cytotoxic mechanisms. Therefore, it is important to examine the possible role of hIAPP in the pathogenesis of AD. In this article, we introduce the basics on this amyloidogenic protein. More importantly, we discuss the potential mechanisms of hIAPP-induced AD development, which will be beneficial for proposing novel and feasible strategies to optimize AD prevention and/or treatment in diabetics.
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Affiliation(s)
- Yun Zhang
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Weihong Song
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
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44
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Magrì A, La Mendola D, Nicoletti VG, Pappalardo G, Rizzarelli E. New Insight in Copper-Ion Binding to Human Islet Amyloid: The Contribution of Metal-Complex Speciation To Reveal the Polypeptide Toxicity. Chemistry 2016; 22:13287-300. [PMID: 27493030 DOI: 10.1002/chem.201602816] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Indexed: 01/05/2023]
Abstract
Type-2 diabetes (T2D) is considered to be a potential threat on a global level. Recently, T2D has been listed as a misfolding disease, such as Alzheimer's and Parkinson's diseases. Human islet amyloid polypeptide (hIAPP) is a molecule cosecreted in pancreatic β cells and represents the main constituent of an aggregated amyloid found in individuals affected by T2D. The trace-element serum level is significantly influenced during the development of diabetes. In particular, the dys-homeostasis of Cu(2+) ions may adversely affect the course of the disease. Conflicting results have been reported on the protective role played by complex species formed by Cu(2+) ions with hIAPP or its peptide fragments in vitro. The histidine (His) residue at position 18 represents the main binding site for the metal ion, but contrasting results have been reported on other residues involved in metal-ion coordination, in particular those toward the N or C terminus. Sequences that encompass regions 17-29 and 14-22 were used to discriminate between the two models of the hIAPP coordination mode. Due to poor solubility in water, poly(ethylene glycol) (PEG) derivatives were synthesized. A peptide fragment that encompasses the 17-29 region of rat amylin (rIAPP) in which the arginine residue at position 18 was substituted by a histidine residue was also obtained to assess that the PEG moiety does not alter the peptide secondary structure. The complex species formed by Cu(2+) ions with Ac-PEG-hIAPP(17-29)-NH2 , Ac-rIAPP(17-29)R18H-NH2 , and Ac-PEG-hIAPP(14-22)-NH2 were studied by using potentiometric titrations coupled with spectroscopic methods (UV/Vis, circular dichroism, and EPR). The combined thermodynamic and spectroscopic approach allowed us to demonstrate that hIAPP is able to bind Cu(2+) ions starting from the His18 imidazole nitrogen atom toward the N-terminus domain. The stability constants of copper(II) complexes with Ac-PEG-hIAPP(14-22)-NH2 were used to simulate the different experimental conditions under which aggregate formation and oxidative stress of hIAPP has been reported. Speciation unveils: 1) the protective role played by increased amounts of Cu(2+) ions on the hIAPP fibrillary aggregation, 2) the effect of adventitious trace amounts of Cu(2+) ions present in phosphate-buffered saline (PBS), and 3) a reducing fluorogenic probe on H2 O2 production attributed to the polypeptide alone.
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Affiliation(s)
- Antonio Magrì
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini, Via P. Gaifami 18, 95126, Catania, Italy.
| | - Diego La Mendola
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno Pisano, 6, 56126, Pisa, Italy.
| | - Vincenzo Giuseppe Nicoletti
- Dipartimento di Scienze Biomediche e Biotecnologiche, Università degli Studi di Catania, Viale A. Doria 6, 95125, Catania, Italy
| | - Giuseppe Pappalardo
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini, Via P. Gaifami 18, 95126, Catania, Italy
| | - Enrico Rizzarelli
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini, Via P. Gaifami 18, 95126, Catania, Italy.,Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125, Catania, Italy
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Abedini A, Plesner A, Cao P, Ridgway Z, Zhang J, Tu LH, Middleton CT, Chao B, Sartori DJ, Meng F, Wang H, Wong AG, Zanni MT, Verchere CB, Raleigh DP, Schmidt AM. Time-resolved studies define the nature of toxic IAPP intermediates, providing insight for anti-amyloidosis therapeutics. eLife 2016; 5. [PMID: 27213520 PMCID: PMC4940161 DOI: 10.7554/elife.12977] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 05/20/2016] [Indexed: 01/04/2023] Open
Abstract
Islet amyloidosis by IAPP contributes to pancreatic β-cell death in diabetes, but the nature of toxic IAPP species remains elusive. Using concurrent time-resolved biophysical and biological measurements, we define the toxic species produced during IAPP amyloid formation and link their properties to induction of rat INS-1 β-cell and murine islet toxicity. These globally flexible, low order oligomers upregulate pro-inflammatory markers and induce reactive oxygen species. They do not bind 1-anilnonaphthalene-8-sulphonic acid and lack extensive β-sheet structure. Aromatic interactions modulate, but are not required for toxicity. Not all IAPP oligomers are toxic; toxicity depends on their partially structured conformational states. Some anti-amyloid agents paradoxically prolong cytotoxicity by prolonging the lifetime of the toxic species. The data highlight the distinguishing properties of toxic IAPP oligomers and the common features that they share with toxic species reported for other amyloidogenic polypeptides, providing information for rational drug design to treat IAPP induced β-cell death. DOI:http://dx.doi.org/10.7554/eLife.12977.001
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Affiliation(s)
- Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Annette Plesner
- Child and Family Research Institute, Department of Pathology and Laboratory Medicine and Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Ping Cao
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Jinghua Zhang
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Ling-Hsien Tu
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Chris T Middleton
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - Brian Chao
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Daniel J Sartori
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
| | - Fanling Meng
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Hui Wang
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Amy G Wong
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, United States
| | - C Bruce Verchere
- Child and Family Research Institute, Department of Pathology and Laboratory Medicine and Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, United States
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University School of Medicine, New York, United States
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46
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Wong AG, Wu C, Hannaberry E, Watson MD, Shea JE, Raleigh DP. Analysis of the Amyloidogenic Potential of Pufferfish (Takifugu rubripes) Islet Amyloid Polypeptide Highlights the Limitations of Thioflavin-T Assays and the Difficulties in Defining Amyloidogenicity. Biochemistry 2016; 55:510-8. [PMID: 26694855 PMCID: PMC5502355 DOI: 10.1021/acs.biochem.5b01107] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Islet amyloid polypeptide (IAPP, amylin) forms pancreatic amyloid in type-2 diabetes, a process that contributes to the loss of β-cell mass in the disease. IAPP has been found in all higher organisms examined, but not all species form amyloid and the ability to do so correlates with the primary sequence. The amyloidogenic potential of fish IAPPs has not been examined, although fish have been proposed as a source for xenobiotic transplantation. The sequence of pufferfish IAPP (Takifugu rubripes) is known and is the most divergent from human IAPP of any reported IAPP sequence, differing at 11 positions including seven located within residues 20-29, a segment of the molecule that is important for controlling amyloidogenicity. Several of the substitutions found in pufferfish IAPP are nonconservative including Ser to Pro, Asn to Thr, Ala to Tyr, and Leu to Tyr replacements, and several of these have not been reported in mammalian IAPP sequences. Amyloid prediction programs give conflicting results for pufferfish IAPP. CD spectroscopy, FTIR, and transmission electron microscopy reveal that pufferfish IAPP forms amyloid and does so more rapidly than human IAPP in tris buffer at pH 7.4, but does so more slowly in phosphate buffered saline (PBS) at pH 7.4. Molecular dynamics simulations indicate that the pufferfish sequence is compatible with models of IAPP amyloid. The fish polypeptide does not significantly bind to thioflavin-T in tris and does so only weakly in PBS. The results highlight difficulties with thioflavin-T assays and the ambiguity in defining amyloidogenicity.
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Affiliation(s)
- Amy G. Wong
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Chun Wu
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Eleni Hannaberry
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Matthew D. Watson
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510
| | - Daniel P. Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
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47
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Caillon L, Hoffmann ARF, Botz A, Khemtemourian L. Molecular Structure, Membrane Interactions, and Toxicity of the Islet Amyloid Polypeptide in Type 2 Diabetes Mellitus. J Diabetes Res 2016; 2016:5639875. [PMID: 26636105 PMCID: PMC4655289 DOI: 10.1155/2016/5639875] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/03/2015] [Indexed: 12/04/2022] Open
Abstract
Human islet amyloid polypeptide (hIAPP) is the major component of the amyloid deposits found in the pancreatic islets of patients with type 2 diabetes mellitus (T2DM). Mature hIAPP, a 37-aa peptide, is natively unfolded in its monomeric state but forms islet amyloid in T2DM. In common with other misfolded and aggregated proteins, amyloid formation involves aggregation of monomers of hIAPP into oligomers, fibrils, and ultimately mature amyloid deposits. hIAPP is coproduced and stored with insulin by the pancreatic islet β-cells and is released in response to the stimuli that lead to insulin secretion. Accumulating evidence suggests that hIAPP amyloid deposits that accompany T2DM are not just an insignificant phenomenon derived from the disease progression but that hIAPP aggregation induces processes that impair the functionality and the viability of β-cells. In this review, we particularly focus on hIAPP structure, hIAPP aggregation, and hIAPP-membrane interactions. We will also discuss recent findings on the mechanism of hIAPP-membrane damage and on hIAPP-induced cell death. Finally, the development of successful antiamyloidogenic agents that prevent hIAPP fibril formation will be examined.
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Affiliation(s)
- Lucie Caillon
- Sorbonne Universités, UPMC Univ Paris 06, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
- Département de Chimie, Ecole Normale Supérieure, PSL Research University, 24 Rue Lhomond, 75005 Paris, France
- CNRS, UMR 7203 Laboratoire des Biomolécules, 75005 Paris, France
| | - Anais R. F. Hoffmann
- Sorbonne Universités, UPMC Univ Paris 06, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
- Département de Chimie, Ecole Normale Supérieure, PSL Research University, 24 Rue Lhomond, 75005 Paris, France
- CNRS, UMR 7203 Laboratoire des Biomolécules, 75005 Paris, France
| | - Alexandra Botz
- Sorbonne Universités, UPMC Univ Paris 06, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
- Département de Chimie, Ecole Normale Supérieure, PSL Research University, 24 Rue Lhomond, 75005 Paris, France
- CNRS, UMR 7203 Laboratoire des Biomolécules, 75005 Paris, France
| | - Lucie Khemtemourian
- Sorbonne Universités, UPMC Univ Paris 06, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
- Département de Chimie, Ecole Normale Supérieure, PSL Research University, 24 Rue Lhomond, 75005 Paris, France
- CNRS, UMR 7203 Laboratoire des Biomolécules, 75005 Paris, France
- *Lucie Khemtemourian:
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48
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Akter R, Cao P, Noor H, Ridgway Z, Tu LH, Wang H, Wong AG, Zhang X, Abedini A, Schmidt AM, Raleigh DP. Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology. J Diabetes Res 2015; 2016:2798269. [PMID: 26649319 PMCID: PMC4662979 DOI: 10.1155/2016/2798269] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/24/2015] [Indexed: 01/29/2023] Open
Abstract
The hormone islet amyloid polypeptide (IAPP, or amylin) plays a role in glucose homeostasis but aggregates to form islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell dysfunction and death in the disease and to the failure of islet transplants. Recent work suggests a role for IAPP aggregation in cardiovascular complications of type-2 diabetes and hints at a possible role in type-1 diabetes. The mechanisms of IAPP amyloid formation in vivo or in vitro are not understood and the mechanisms of IAPP induced β-cell death are not fully defined. Activation of the inflammasome, defects in autophagy, ER stress, generation of reactive oxygen species, membrane disruption, and receptor mediated mechanisms have all been proposed to play a role. Open questions in the field include the relative importance of the various mechanisms of β-cell death, the relevance of reductionist biophysical studies to the situation in vivo, the molecular mechanism of amyloid formation in vitro and in vivo, the factors which trigger amyloid formation in type-2 diabetes, the potential role of IAPP in type-1 diabetes, the development of clinically relevant inhibitors of islet amyloidosis toxicity, and the design of soluble, bioactive variants of IAPP for use as adjuncts to insulin therapy.
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Affiliation(s)
- Rehana Akter
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Ping Cao
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Harris Noor
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Ling-Hsien Tu
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Hui Wang
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Amy G. Wong
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Xiaoxue Zhang
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Andisheh Abedini
- Diabetes Research Program, NYU School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Ann Marie Schmidt
- Diabetes Research Program, NYU School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Daniel P. Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
- Research Department of Structural and Molecule Biology, University College London, Gower Street, London WC1E 6BT, UK
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49
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Meier DT, Tu LH, Zraika S, Hogan MF, Templin AT, Hull RL, Raleigh DP, Kahn SE. Matrix Metalloproteinase-9 Protects Islets from Amyloid-induced Toxicity. J Biol Chem 2015; 290:30475-85. [PMID: 26483547 DOI: 10.1074/jbc.m115.676692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Indexed: 12/21/2022] Open
Abstract
Deposition of human islet amyloid polypeptide (hIAPP, also known as amylin) as islet amyloid is a characteristic feature of the pancreas in type 2 diabetes, contributing to increased β-cell apoptosis and reduced β-cell mass. Matrix metalloproteinase-9 (MMP-9) is active in islets and cleaves hIAPP. We investigated whether hIAPP fragments arising from MMP-9 cleavage retain the potential to aggregate and cause toxicity, and whether overexpressing MMP-9 in amyloid-prone islets reduces amyloid burden and the resulting β-cell toxicity. Synthetic hIAPP was incubated with MMP-9 and the major hIAPP fragments observed by MS comprised residues 1-15, 1-25, 16-37, 16-25, and 26-37. The fragments 1-15, 1-25, and 26-37 did not form amyloid fibrils in vitro and they were not cytotoxic when incubated with β cells. Mixtures of these fragments with full-length hIAPP did not modulate the kinetics of fibril formation by full-length hIAPP. In contrast, the 16-37 fragment formed fibrils more rapidly than full-length hIAPP but was less cytotoxic. Co-incubation of MMP-9 and fragment 16-37 ablated amyloidogenicity, suggesting that MMP-9 cleaves hIAPP 16-37 into non-amyloidogenic fragments. Consistent with MMP-9 cleavage resulting in largely non-amyloidogenic degradation products, adenoviral overexpression of MMP-9 in amyloid-prone islets reduced amyloid deposition and β-cell apoptosis. These findings suggest that increasing islet MMP-9 activity might be a strategy to limit β-cell loss in type 2 diabetes.
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Affiliation(s)
- Daniel T Meier
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108
| | - Ling-Hsien Tu
- Genomic Research Center, Academia Sinica, Taipei, Taiwan, Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, and
| | - Sakeneh Zraika
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108
| | - Meghan F Hogan
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108
| | - Andrew T Templin
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108
| | - Rebecca L Hull
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, and Department of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - Steven E Kahn
- From the VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108,
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50
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Ghosh A, Ho JJ, Serrano AL, Skoff DR, Zhang T, Zanni MT. Two-dimensional sum-frequency generation (2D SFG) spectroscopy: summary of principles and its application to amyloid fiber monolayers. Faraday Discuss 2015; 177:493-505. [PMID: 25611039 DOI: 10.1039/c4fd00173g] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
By adding a mid-infrared pulse shaper to a sum-frequency generation (SFG) spectrometer, we have built a 2D SFG spectrometer capable of measuring spectra analogous to 2D IR spectra but with monolayer sensitivity and SFG selection rules. In this paper, we describe the experimental apparatus and provide an introduction to 2D SFG spectroscopy to help the reader interpret 2D SFG spectra. The main aim of this manuscript is to report 2D SFG spectra of the amyloid forming peptide FGAIL. FGAIL is a critical segment of the human islet amyloid polypeptide (hIAPP or amylin) that aggregates in people with type 2 diabetes. FGAIL is catalyzed into amyloid fibers by many types of surfaces. Here, we study the structure of FGAIL upon deposition onto a gold surface covered with a self-assembled monolayer of methyl-4-mercaptobenzoate (MMB) that produces an ester coating. FGAIL deposited on bare gold does not form ordered layers. The measured 2D SFG spectrum is consistent with amyloid fiber formation, exhibiting both the parallel (a+) and perpendicular (a-) symmetry modes associated with amyloid β-sheets. Cross peaks are observed between the ester stretches of the coating and the FGAIL peptides. Simulations are presented for two possible structures of FGAIL amyloid β-sheets that illustrate the sensitivity of the 2D SFG spectra to structure and orientation. These results provide some of the first molecular insights into surface catalyzed amyloid fiber structure.
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Affiliation(s)
- Ayanjeet Ghosh
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA.
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