1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Cardoso LEM, Marinho TS, Martins FF, Aguila MB, Mandarim-de-Lacerda CA. Treatment with semaglutide, a GLP-1 receptor agonist, improves extracellular matrix remodeling in the pancreatic islet of diet-induced obese mice. Life Sci 2023; 319:121502. [PMID: 36796719 DOI: 10.1016/j.lfs.2023.121502] [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: 12/24/2022] [Revised: 02/02/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023]
Abstract
AIMS The extracellular matrix (ECM) is fundamental for the normal endocrine functions of pancreatic islet cells and plays key roles in the pathophysiology of type 2 diabetes. Here we investigated the turnover of islet ECM components, including islet amyloid polypeptide (IAPP), in an obese mouse model treated with semaglutide, a glucagon-like peptide type 1 receptor agonist. MAIN METHODS Male one-month-old C57BL/6 mice were fed a control diet (C) or a high-fat diet (HF) for 16 weeks, then treated with semaglutide (subcutaneous 40 μg/kg every three days) for an additional four weeks (HFS). The islets were immunostained and gene expressions were assessed. KEY FINDINGS Comparisons refer to HFS vs HF. Thus, IAPP immunolabeling and beta-cell-enriched beta-amyloid precursor protein cleaving enzyme (Bace2, -40 %) and heparanase immunolabeling and gene (Hpse, -40 %) were mitigated by semaglutide. In contrast, perlecan (Hspg2, +900 %) and vascular endothelial growth factor A (Vegfa, +420 %) were enhanced by semaglutide. Also, semaglutide lessened syndecan 4 (Sdc4, -65 %) and hyaluronan synthases (Has1, -45 %; Has2, -65 %) as well as chondroitin sulfate immunolabeling, and collagen type 1 (Col1a1, -60 %) and type 6 (Col6a3, -15 %), lysyl oxidase (Lox, -30 %) and metalloproteinases (Mmp2, -45 %; Mmp9, -60 %). SIGNIFICANCE Semaglutide improved the turnover of islet heparan sulfate proteoglycans, hyaluronan, chondroitin sulfate proteoglycans, and collagens in the islet ECM. Such changes should contribute to restoring a healthy islet functional milieu and should reduce the formation of cell-damaging amyloid deposits. Our findings also provide additional evidence for the involvement of islet proteoglycans in the pathophysiology of type 2 diabetes.
Collapse
Affiliation(s)
- Luiz E M Cardoso
- Laboratory of Morphometry, Metabolism, and Cardiovascular disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Thatiany Souza Marinho
- Laboratory of Morphometry, Metabolism, and Cardiovascular disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabiane Ferreira Martins
- Laboratory of Morphometry, Metabolism, and Cardiovascular disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcia Barbosa Aguila
- Laboratory of Morphometry, Metabolism, and Cardiovascular disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Carlos A Mandarim-de-Lacerda
- Laboratory of Morphometry, Metabolism, and Cardiovascular disease, Biomedical Center, Institute of Biology, The University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Milardi D, Gazit E, Radford SE, Xu Y, Gallardo RU, Caflisch A, Westermark GT, Westermark P, Rosa CL, Ramamoorthy A. Proteostasis of Islet Amyloid Polypeptide: A Molecular Perspective of Risk Factors and Protective Strategies for Type II Diabetes. Chem Rev 2021; 121:1845-1893. [PMID: 33427465 DOI: 10.1021/acs.chemrev.0c00981] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The possible link between hIAPP accumulation and β-cell death in diabetic patients has inspired numerous studies focusing on amyloid structures and aggregation pathways of this hormone. Recent studies have reported on the importance of early oligomeric intermediates, the many roles of their interactions with lipid membrane, pH, insulin, and zinc on the mechanism of aggregation of hIAPP. The challenges posed by the transient nature of amyloid oligomers, their structural heterogeneity, and the complex nature of their interaction with lipid membranes have resulted in the development of a wide range of biophysical and chemical approaches to characterize the aggregation process. While the cellular processes and factors activating hIAPP-mediated cytotoxicity are still not clear, it has recently been suggested that its impaired turnover and cellular processing by proteasome and autophagy may contribute significantly toward toxic hIAPP accumulation and, eventually, β-cell death. Therefore, studies focusing on the restoration of hIAPP proteostasis may represent a promising arena for the design of effective therapies. In this review we discuss the current knowledge of the structures and pathology associated with hIAPP self-assembly and point out the opportunities for therapy that a detailed biochemical, biophysical, and cellular understanding of its aggregation may unveil.
Collapse
Affiliation(s)
- Danilo Milardi
- Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, Via P. Gaifami 18, 95126 Catania, Italy
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yong Xu
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rodrigo U Gallardo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Gunilla T Westermark
- Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 41809-1055, United States
| |
Collapse
|
5
|
Bishoyi AK, Roham PH, Rachineni K, Save S, Hazari MA, Sharma S, Kumar A. Human islet amyloid polypeptide (hIAPP) - a curse in type II diabetes mellitus: insights from structure and toxicity studies. Biol Chem 2020; 402:133-153. [PMID: 33544470 DOI: 10.1515/hsz-2020-0174] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
The human islet amyloid polypeptide (hIAPP) or amylin, a neuroendocrine peptide hormone, is known to misfold and form amyloidogenic aggregates that have been observed in the pancreas of 90% subjects with Type 2 Diabetes Mellitus (T2DM). Under normal physiological conditions, hIAPP is co-stored and co-secreted with insulin; however, under chronic hyperglycemic conditions associated with T2DM, the overexpression of hIAPP occurs that has been associated with the formation of amyloid deposits; as well as the death and dysfunction of pancreatic β-islets in T2DM. Hitherto, various biophysical and structural studies have shown that during this process of aggregation, the peptide conformation changes from random structure to helix, then to β-sheet, subsequently to cross β-sheets, which finally form left-handed helical aggregates. The intermediates, formed during this process, have been shown to induce higher cytotoxicity in the β-cells by inducing cell membrane disruption, endoplasmic reticulum stress, mitochondrial dysfunction, oxidative stress, islet inflammation, and DNA damage. As a result, several research groups have attempted to target both hIAPP aggregation phenomenon and the destabilization of preformed fibrils as a therapeutic intervention for T2DM management. In this review, we have summarized structural aspects of various forms of hIAPP viz. monomer, oligomers, proto-filaments, and fibrils of hIAPP. Subsequently, cellular toxicity caused by toxic conformations of hIAPP has been elaborated upon. Finally, the need for performing structural and toxicity studies in vivo to fill in the gap between the structural and cellular aspects has been discussed.
Collapse
Affiliation(s)
- Ajit Kumar Bishoyi
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Pratiksha H Roham
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Kavitha Rachineni
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shreyada Save
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - M Asrafuddoza Hazari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| | - Shilpy Sharma
- Department of Biotechnology, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411007, Maharashtra, India
| | - Ashutosh Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, Maharashtra, India
| |
Collapse
|
6
|
Templin AT, Mellati M, Soininen R, Hogan MF, Esser N, Castillo JJ, Zraika S, Kahn SE, Hull RL. Loss of perlecan heparan sulfate glycosaminoglycans lowers body weight and decreases islet amyloid deposition in human islet amyloid polypeptide transgenic mice. Protein Eng Des Sel 2020; 32:95-102. [PMID: 31769491 DOI: 10.1093/protein/gzz041] [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: 06/03/2019] [Revised: 09/24/2019] [Accepted: 10/01/2019] [Indexed: 11/14/2022] Open
Abstract
Islet amyloid is a pathologic feature of type 2 diabetes (T2D) that is associated with β-cell loss and dysfunction. These amyloid deposits form via aggregation of the β-cell secretory product islet amyloid polypeptide (IAPP) and contain other molecules including the heparan sulfate proteoglycan perlecan. Perlecan has been shown to bind amyloidogenic human IAPP (hIAPP) via its heparan sulfate glycosaminoglycan (HS GAG) chains and to enhance hIAPP aggregation in vitro. We postulated that reducing the HS GAG content of perlecan would also decrease islet amyloid deposition in vivo. hIAPP transgenic mice were crossed with Hspg2Δ3/Δ3 mice harboring a perlecan mutation that prevents HS GAG attachment (hIAPP;Hspg2Δ3/Δ3), and male offspring from this cross were fed a high fat diet for 12 months to induce islet amyloid deposition. At the end of the study body weight, islet amyloid area, β-cell area, glucose tolerance and insulin secretion were analyzed. hIAPP;Hspg2Δ3/Δ3 mice exhibited significantly less islet amyloid deposition and greater β-cell area compared to hIAPP mice expressing wild type perlecan. hIAPP;Hspg2Δ3/Δ3 mice also gained significantly less weight than other genotypes. When adjusted for differences in body weight using multiple linear regression modeling, we found no differences in islet amyloid deposition or β-cell area between hIAPP transgenic and hIAPP;Hspg2Δ3/Δ3 mice. We conclude that loss of perlecan exon 3 reduces islet amyloid deposition in vivo through indirect effects on body weight and possibly also through direct effects on hIAPP aggregation. Both of these mechanisms may promote maintenance of glucose homeostasis in the setting of T2D.
Collapse
Affiliation(s)
- Andrew T Templin
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Mahnaz Mellati
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Raija Soininen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Pentti Kaiteran Katu 1, Linnanmaa, Oulu, Finland
| | - Meghan F Hogan
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Nathalie Esser
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - J Josh Castillo
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Sakeneh Zraika
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Steven E Kahn
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| | - Rebecca L Hull
- Division of Metabolism, Endocrinology and Nutrition, Veterans Affairs Puget Sound Health Care System and University of Washington, 1660 South Columbian Way, Seattle, 98108, Washington, USA
| |
Collapse
|
7
|
Li JP, Zhang X. Implications of Heparan Sulfate and Heparanase in Amyloid Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1221:631-645. [PMID: 32274729 DOI: 10.1007/978-3-030-34521-1_25] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Amyloidosis refers to a group of diseases characterized by abnormal deposition of denatured endogenous proteins, termed amyloid, in the affected organs. Analysis of biopsy and autopsy tissues from patients revealed the presence of heparan sulfate proteoglycans (HSPGs) along with amyloid proteins in the deposits. For a long time, HSPGs were believed to occur in the deposits as an innocent bystander. Yet, the consistent presence of HSPGs in various deposits, regardless of the amyloid species, led to the hypothesis that these macromolecular glycoconjugates might play functional roles in the pathological process of amyloidosis. In vitro studies have revealed that HSPGs, or more precisely, the heparan sulfate (HS) side chains interact with amyloid peptides, thus promoting amyloid fibrillization. Although information on the mechanisms of HS participation in amyloid deposition is limited, recent studies involving a transgenic mouse model of Alzheimer's disease point to an active role of HS in amyloid formation. Heparanase cleavage alters the molecular structure of HS, and thus modulates the functional roles of HS in homeostasis, as well as in diseases, including amyloidosis. The heparanase transgenic mice have provided models for unveiling the effects of heparanase, through cleavage of HS, in various amyloidosis conditions.
Collapse
Affiliation(s)
- Jin-Ping Li
- Department of Medical Biochemistry and Microbiology and the SciLifeLab, Uppsala University, Uppsala, Sweden.
| | - Xiao Zhang
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| |
Collapse
|
8
|
Xin Y, Wang X, Luo L, Meng F. Conformation-Dependent Manipulation of Human Islet Amyloid Polypeptide Fibrillation by Shiitake-Derived Lentinan. ACS APPLIED MATERIALS & INTERFACES 2018; 10:31069-31079. [PMID: 30148596 DOI: 10.1021/acsami.8b11078] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Misfolding and aggregation of human islet amyloid polypeptide (hIAPP) into fibrils are important contributions to the pathology of type 2 diabetes. Developing effective inhibitors of protein aggregation and fibrillation has been considered a promising therapeutic approach to preventing and treating type 2 diabetes. Herein, we report that Shiitake-derived polysaccharide lentinan manipulates in vitro hIAPP fibrillation and modulates IAPP-induced cytotoxicity in a conformation-dependent manner. In its triple-helical conformation, lentinan effectively inhibits hIAPP fibrillation, either in bulk solution or in the presence of lipid membrane, suppresses reactive oxygen species (ROS) generation, and attenuates hIAPP-induced cell toxicity. In contrast, lentinan accelerates hIAPP aggregation when it exists in a random-coil conformation and shows no suppression on hIAPP-mediated ROS production. Further investigation shows that the interaction between triple-helical lentinan and monomeric hIAPP is more favorable than the intermolecular binding of hIAPP, which redirects hIAPP aggregates to discrete nontoxic nanocomposites. To the best of our knowledge, this is the first time to report a conformation-dependent inhibition of hIAPP aggregation, which will provide new insights for our understanding of the manipulation mechanisms on hIAPP by natural polysaccharides and open a new avenue for designing and screening potential amyloid inhibitors against type 2 diabetes.
Collapse
Affiliation(s)
- Yanru Xin
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Xiuxia Wang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Liang Luo
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
- Wuhan Institute of Biotechnology , Wuhan 430075 , China
| | - Fanling Meng
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China
- Wuhan Institute of Biotechnology , Wuhan 430075 , China
| |
Collapse
|
9
|
Glycosaminoglycan-Protein Interactions by Nuclear Magnetic Resonance (NMR) Spectroscopy. Molecules 2018; 23:molecules23092314. [PMID: 30208595 PMCID: PMC6225283 DOI: 10.3390/molecules23092314] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 08/29/2018] [Accepted: 09/05/2018] [Indexed: 02/07/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most utilized and informative analytical techniques for investigating glycosaminoglycan (GAG)-protein complexes. NMR methods that are commonly applied to GAG-protein systems include chemical shift perturbation, saturation transfer difference, and transferred nuclear Overhauser effect. Although these NMR methods have revealed valuable insight into the protein-GAG complexes, elucidating high-resolution structural and dynamic information of these often transient interactions remains challenging. In addition, preparation of structurally homogeneous and isotopically enriched GAG ligands for structural investigations continues to be laborious. As a result, understanding of the structure-activity relationship of GAGs is still primitive. To overcome these deficiencies, several innovative NMR techniques have been developed lately. Here, we review some of the commonly used techniques along with more novel methods such as waterLOGSY and experiments to examine structure and dynamic of lysine and arginine side chains to identify GAG-binding sites. We will also present the latest technology that is used to produce isotopically enriched as well as paramagnetically tagged GAG ligands. Recent results that were obtained from solid-state NMR of amyloid’s interaction with GAG are also presented together with a brief discussion on computer assisted modeling of GAG-protein complexes using sparse experimental data.
Collapse
|
10
|
Chen YC, Taylor AJ, Verchere CB. Islet prohormone processing in health and disease. Diabetes Obes Metab 2018; 20 Suppl 2:64-76. [PMID: 30230179 DOI: 10.1111/dom.13401] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022]
Abstract
Biosynthesis of peptide hormones by pancreatic islet endocrine cells is a tightly orchestrated process that is critical for metabolic homeostasis. Like neuroendocrine peptides, insulin and other islet hormones are first synthesized as larger precursor molecules that are processed to their mature secreted products through a series of proteolytic cleavages, mediated by the prohormone convertases Pc1/3 and Pc2, and carboxypeptidase E. Additional posttranslational modifications including C-terminal amidation of the β-cell peptide islet amyloid polypeptide (IAPP) by peptidyl-glycine α-amidating monooxygenase (Pam) may also occur. Genome-wide association studies (GWAS) have showed genetic linkage of these processing enzymes to obesity, β-cell dysfunction, and type 2 diabetes (T2D), pointing to their important roles in metabolism and blood glucose regulation. In both type 1 diabetes (T1D) and T2D, and in the face of metabolic or inflammatory stresses, islet prohormone processing may become impaired; indeed elevated proinsulin:insulin (PI:I) ratios are a hallmark of the β-cell dysfunction in T2D. Recent studies suggest that genetic or acquired defects in proIAPP processing may lead to the production and secretion of incompletely processed forms of proIAPP that could contribute to T2D pathogenesis, and additionally that impaired processing of both PI and proIAPP may be characteristic of β-cell dysfunction in T1D. In islet α-cells, the prohormone proglucagon is normally processed to bioactive glucagon by Pc2 but may express Pc1/3 under certain conditions leading to production of GLP-1(7-36NH2 ). A better understanding of how β-cell processing of PI and proIAPP, as well as α-cell processing of proglucagon, are impacted by genetic susceptibility and in the face of diabetogenic stresses, may lead to new therapeutic approaches for improving islet function in diabetes.
Collapse
Affiliation(s)
- Yi-Chun Chen
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
| | - Austin J Taylor
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
| | - C Bruce Verchere
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
11
|
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]
|
12
|
Asthana S, Sahu M, Nayak PS, Mallick B, Jha S. The smaller heparin fragments bind non-specifically through the IAPP sequence: An in silico study. Int J Biol Macromol 2018; 113:1092-1104. [DOI: 10.1016/j.ijbiomac.2018.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 02/28/2018] [Accepted: 03/01/2018] [Indexed: 11/29/2022]
|
13
|
Amyloid growth and membrane damage: Current themes and emerging perspectives from theory and experiments on Aβ and hIAPP. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1625-1638. [PMID: 29501606 DOI: 10.1016/j.bbamem.2018.02.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's Disease (AD) and Type 2 diabetes mellitus (T2DM) are two incurable diseases both hallmarked by an abnormal deposition of the amyloidogenic peptides Aβ and Islet Amyloid Polypeptide (IAPP) in affected tissues. Epidemiological data demonstrate that patients suffering from diabetes are at high risk of developing AD, thus making the search for factors common to the two pathologies of special interest for the design of new therapies. Accumulating evidence suggests that the toxic properties of both Aβ or IAPP are ascribable to their ability to damage the cell membrane. However, the molecular details describing Aβ or IAPP interaction with membranes are poorly understood. This review focuses on biophysical and in silico studies addressing these topics. Effects of calcium, cholesterol and membrane lipid composition in driving aberrant Aβ or IAPP interaction with the membrane will be specifically considered. The cross correlation of all these factors appears to be a key issue not only to shed light in the countless and often controversial reports relative to this area but also to gain valuable insights into the central events leading to membrane damage caused by amyloidogenic peptides. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
Collapse
|
14
|
Stewart KL, Hughes E, Yates EA, Middleton DA, Radford SE. Molecular Origins of the Compatibility between Glycosaminoglycans and Aβ40 Amyloid Fibrils. J Mol Biol 2017; 429:2449-2462. [PMID: 28697887 PMCID: PMC5548265 DOI: 10.1016/j.jmb.2017.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/04/2017] [Accepted: 07/06/2017] [Indexed: 10/25/2022]
Abstract
The Aβ peptide forms extracellular plaques associated with Alzheimer's disease. In addition to protein fibrils, amyloid plaques also contain non-proteinaceous components, including glycosaminoglycans (GAGs). We have shown previously that the GAG low-molecular-weight heparin (LMWH) binds to Aβ40 fibrils with a three-fold-symmetric (3Q) morphology with higher affinity than Aβ40 fibrils in alternative structures, Aβ42 fibrils, or amyloid fibrils formed from other sequences. Solid-state NMR analysis of the GAG-3Q fibril complex revealed an interaction site at the corners of the 3Q fibril structure, but the origin of the binding specificity remained obscure. Here, using a library of short heparin polysaccharides modified at specific sites, we show that the N-sulfate or 6-O-sulfate of glucosamine, but not the 2-O-sulfate of iduronate within heparin is required for 3Q binding, indicating selectivity in the interactions of the GAG with the fibril that extends beyond general electrostatic complementarity. By creating 3Q fibrils containing point substitutions in the amino acid sequence, we also show that charged residues at the fibril three-fold apices provide the majority of the binding free energy, while charged residues elsewhere are less critical for binding. The results indicate, therefore, that LMWH binding to 3Q fibrils requires a precise molecular complementarity of the sulfate moieties on the GAG and charged residues displayed on the fibril surface. Differences in GAG binding to fibrils with distinct sequence and/or structure may thus contribute to the diverse etiology and progression of amyloid diseases.
Collapse
Affiliation(s)
- Katie L Stewart
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Eleri Hughes
- Department of Chemistry, University of Lancaster, Lancaster LA1 4YB, UK
| | - Edwin A Yates
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - David A Middleton
- Department of Chemistry, University of Lancaster, Lancaster LA1 4YB, UK.
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK.
| |
Collapse
|
15
|
Quittot N, Sebastiao M, Bourgault S. Modulation of amyloid assembly by glycosaminoglycans: from mechanism to biological significance. Biochem Cell Biol 2017; 95:329-337. [DOI: 10.1139/bcb-2016-0236] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glycosaminoglycans (GAGs) are long and unbranched polysaccharides that are abundant in the extracellular matrix and basement membrane of multicellular organisms. These linear polyanionic macromolecules are involved in many physiological functions from cell adhesion to cellular signaling. Interestingly, amyloid fibrils extracted from patients afflicted with protein misfolding diseases are virtually always associated with GAGs. Amyloid fibrils are highly organized nanostructures that have been historically associated with pathological states, such as Alzheimer’s disease and systemic amyloidoses. However, recent studies have identified functional amyloids that accomplish crucial physiological roles in almost all living organisms, from bacteria to insects and mammals. Over the last 2 decades, numerous reports have revealed that sulfated GAGs accelerate and (or) promote the self-assembly of a large diversity of proteins, both inherently amyloidogenic and non-aggregation prone. Despite the fact that many studies have investigated the molecular mechanism(s) by which GAGs induce amyloid assembly, the mechanistic elucidation of GAG-mediated amyloidogenesis still remains the subject of active research. In this review, we expose the contribution of GAGs in amyloid assembly, and we discuss the pathophysiological and functional significance of GAG-mediated fibrillization. Finally, we propose mechanistic models of the unique and potent ability of sulfated GAGs to hasten amyloid fibril formation.
Collapse
Affiliation(s)
- Noé Quittot
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
| | - Mathew Sebastiao
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
| | - Steve Bourgault
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
- Department of Chemistry, Pharmaqam, C.P. 8888, Succursale Centre-Ville, Université du Québec à Montréal (UQAM), Montreal, QC H3C 3P8, Canada
| |
Collapse
|
16
|
Courtade JA, Wang EY, Yen P, Dai DL, Soukhatcheva G, Orban PC, Verchere CB. Loss of prohormone convertase 2 promotes beta cell dysfunction in a rodent transplant model expressing human pro-islet amyloid polypeptide. Diabetologia 2017; 60:453-463. [PMID: 27999871 DOI: 10.1007/s00125-016-4174-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 10/03/2016] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS A contributor to beta cell failure in type 2 diabetes and islet transplants is amyloid formation by aggregation of the beta cell peptide, islet amyloid polypeptide (IAPP). Similar to the proinsulin processing pathway that generates insulin, IAPP is derived from a prohormone precursor, proIAPP, which requires cleavage by prohormone convertase (PC) 1/3 and PC2 in rodent pancreatic beta cells. We hypothesised that loss of PC2 would promote beta cell death and dysfunction in a rodent model of human beta cell proIAPP overexpression. METHODS We generated an islet transplant model wherein immune-deficient mouse models of diabetes received islets expressing amyloidogenic human proIAPP and lacking PC2, leading to restoration of normoglycaemia accompanied by increased secretion of human proIAPP. Blood glucose levels were analysed for up to 16 weeks in transplant recipients and grafts were assessed for islet amyloid and beta cell number and death. RESULTS Hyperglycaemia (blood glucose >16.9 mmol/l) returned in 94% of recipients of islets expressing human proIAPP and lacking PC2, whereas recipients of islets that express human proIAPP and normal PC2 levels remained normoglycaemic for at least 16 weeks. Islet graft failure was accompanied by a ∼20% reduction in insulin-positive cells, yet the degree of amyloid deposition and beta cell apoptosis was similar to those of controls expressing human proIAPP with functional PC2 levels. CONCLUSIONS/INTERPRETATION PC2 deficiency in transplanted mouse islets expressing human proIAPP promotes beta cell loss and graft failure. Our data suggest that impaired NH2-terminal processing and increased secretion of human proIAPP promote beta cell failure.
Collapse
Affiliation(s)
- Jaques A Courtade
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Evan Y Wang
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Paul Yen
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Derek L Dai
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Galina Soukhatcheva
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Paul C Orban
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - C Bruce Verchere
- Research Institute, BC Children's Hospital, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4, Canada.
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
17
|
Zhang X, St Clair JR, London E, Raleigh DP. Islet Amyloid Polypeptide Membrane Interactions: Effects of Membrane Composition. Biochemistry 2017; 56:376-390. [PMID: 28054763 DOI: 10.1021/acs.biochem.6b01016] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloid formation by islet amyloid polypeptide (IAPP) contributes to β-cell dysfunction in type 2 diabetes. Perturbation of the β-cell membrane may contribute to IAPP-induced toxicity. We examine the effects of lipid composition, salt, and buffer on IAPP amyloid formation and on the ability of IAPP to induce leakage of model membranes. Even low levels of anionic lipids promote amyloid formation and membrane permeabilization. Increasing the percentage of the anionic lipids, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS) or 1,2-dioleoyl-sn-glycero-3-phospho(1'-rac-glycerol), enhances the rate of amyloid formation and increases the level of membrane permeabilization. The choice of zwitterionic lipid has no noticeable effect on membrane-catalyzed amyloid formation but in most cases affects leakage, which tends to decrease in the following order: 1,2-dioleoyl-sn-glycero-3-phosphocholine > 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine > sphingomyelin. Uncharged lipids that increase the level of membrane order weaken the ability of IAPP to induce leakage. Leakage is due predominately to pore formation rather than complete disruption of the vesicles under the conditions used in these studies. Cholesterol at or below physiological levels significantly reduces the rate of vesicle-catalyzed IAPP amyloid formation and decreases the susceptibility to IAPP-induced leakage. The effects of cholesterol on amyloid formation are masked by 25 mol % POPS. Overall, there is a strong inverse correlation between the time to form amyloid and the extent of vesicle leakage. NaCl reduces the rate of membrane-catalyzed amyloid formation by anionic vesicles, but accelerates amyloid formation in solution. The implications for IAPP membrane interactions are discussed, as is the possibility that the loss of phosphatidylserine asymmetry enhances IAPP amyloid formation and membrane damage in vivo via a positive feedback loop.
Collapse
Affiliation(s)
- Xiaoxue Zhang
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States
| | - Johnna R St Clair
- Department of Biochemistry and Cell Biology, Stony Brook University , Stony Brook, New York 11794-5215, United States
| | - Erwin London
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States.,Department of Biochemistry and Cell Biology, Stony Brook University , Stony Brook, New York 11794-5215, United States
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States.,Graduate Program in Biochemistry and Structural Biology, Stony Brook University , Stony Brook, New York 11794-5215, United States
| |
Collapse
|
18
|
Li JP, Kusche-Gullberg M. Heparan Sulfate: Biosynthesis, Structure, and Function. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:215-73. [PMID: 27241222 DOI: 10.1016/bs.ircmb.2016.02.009] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Heparan sulfate (HS) proteoglycans (PGs) are ubiquitously expressed on cell surfaces and in the extracellular matrix of most animal tissues, having essential functions in development and homeostasis, as well as playing various roles in disease processes. The functions of HSPGs are mainly dependent on interactions between the HS-side chains with a variety of proteins including cytokines, growth factors, and their receptors. In a given HS polysaccharide, negatively charged sulfate and carboxylate groups are arranged in various types of domains, generated through strictly regulated biosynthetic reactions and with enormous potential for structural variability. The mode of HS-protein interactions is assessed through binding experiments using saccharides of defined composition in vitro, signaling assays in cell models where HS structures are manipulated, and targeted disruption of genes for biosynthetic enzymes in animals (mouse, zebrafish, Drosophila, and Caenorhabditis elegans) followed by phenotype analysis. Whereas some protein ligands appear to require strictly defined HS structure, others bind to variable saccharide domains without apparent dependence on distinct saccharide sequence. These findings raise intriguing questions concerning the functional significance of regulation in HS biosynthesis and the potential for development of therapeutics targeting HS-protein interactions.
Collapse
Affiliation(s)
- J-P Li
- Department of Medical Biochemistry and Microbiology, University of Uppsala, Uppsala, Sweden; SciLifeLab, University of Uppsala, Uppsala, Sweden.
| | | |
Collapse
|
19
|
Oskarsson ME, Singh K, Wang J, Vlodavsky I, Li JP, Westermark GT. Heparan Sulfate Proteoglycans Are Important for Islet Amyloid Formation and Islet Amyloid Polypeptide-induced Apoptosis. J Biol Chem 2015; 290:15121-32. [PMID: 25922077 PMCID: PMC4463455 DOI: 10.1074/jbc.m114.631697] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/16/2015] [Indexed: 12/23/2022] Open
Abstract
Deposition of β cell toxic islet amyloid is a cardinal finding in type 2 diabetes. In addition to the main amyloid component islet amyloid polypeptide (IAPP), heparan sulfate proteoglycan is constantly present in the amyloid deposit. Heparan sulfate (HS) side chains bind to IAPP, inducing conformational changes of the IAPP structure and an acceleration of fibril formation. We generated a double-transgenic mouse strain (hpa-hIAPP) that overexpresses human heparanase and human IAPP but is deficient of endogenous mouse IAPP. Culture of hpa-hIAPP islets in 20 mm glucose resulted in less amyloid formation compared with the amyloid load developed in cultured islets isolated from littermates expressing human IAPP only. A similar reduction of amyloid was achieved when human islets were cultured in the presence of heparin fragments. Furthermore, we used CHO cells and the mutant CHO pgsD-677 cell line (deficient in HS synthesis) to explore the effect of cellular HS on IAPP-induced cytotoxicity. Seeding of IAPP aggregation on CHO cells resulted in caspase-3 activation and apoptosis that could be prevented by inhibition of caspase-8. No IAPP-induced apoptosis was seen in HS-deficient CHO pgsD-677 cells. These results suggest that β cell death caused by extracellular IAPP requires membrane-bound HS. The interaction between HS and IAPP or the subsequent effects represent a possible therapeutic target whose blockage can lead to a prolonged survival of β cells.
Collapse
Affiliation(s)
| | | | - Jian Wang
- Ningxia People's Hospital, Yinchuan 750021, China, and Medical Biochemistry and Microbiology, Uppsala University, Box 571, 75123 Uppsala, Sweden
| | - Israel Vlodavsky
- the Cancer and Vascular Biology Research Center, The Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel
| | - Jin-Ping Li
- Medical Biochemistry and Microbiology, Uppsala University, Box 571, 75123 Uppsala, Sweden,
| | | |
Collapse
|
20
|
Potter KJ, Werner I, Denroche HC, Montane J, Plesner A, Chen Y, Lei D, Soukhatcheva G, Warnock GL, Oberholzer J, Fraser PE, Verchere CB. Amyloid formation in human islets is enhanced by heparin and inhibited by heparinase. Am J Transplant 2015; 15:1519-30. [PMID: 25833002 DOI: 10.1111/ajt.13134] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 11/16/2014] [Accepted: 11/16/2014] [Indexed: 01/25/2023]
Abstract
Islet transplantation is a promising therapy for patients with diabetes, but its long-term success is limited by many factors, including the formation of islet amyloid deposits. Heparin is employed in clinical islet transplantation to reduce clotting but also promotes fibrillization of amyloidogenic proteins. We hypothesized that heparin treatment of islets during pre-transplant culture may enhance amyloid formation leading to beta cell loss and graft dysfunction. Heparin promoted the fibrillization of human islet amyloid polypeptide (IAPP) and enhanced its toxicity to INS-1 beta cells. Heparin increased amyloid deposition in cultured human islets, but surprisingly decreased islet cell apoptosis. Treatment of human islets with heparin prior to transplantation increased the likelihood of graft failure. Removal of islet heparan sulfate glycosaminoglycans, which localize with islet amyloid deposits in type 2 diabetes, by heparinase treatment decreased amyloid deposition and protected against islet cell death. These findings raise the possibility that pretransplant treatment of human islets with heparin could potentiate IAPP aggregation and amyloid formation and may be detrimental to subsequent graft function.
Collapse
Affiliation(s)
- K J Potter
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - I Werner
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - H C Denroche
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - J Montane
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - A Plesner
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Y Chen
- Department of Medical Biophysics, Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, ON, Canada
| | - D Lei
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - G Soukhatcheva
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | - G L Warnock
- Surgery, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - J Oberholzer
- Surgery, and Bioengineering, University of Illinois, Chicago, IL
| | - P E Fraser
- Department of Medical Biophysics, Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, ON, Canada
| | - C B Verchere
- Departments of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.,Surgery, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
21
|
Mukherjee A, Morales-Scheihing D, Butler PC, Soto C. Type 2 diabetes as a protein misfolding disease. Trends Mol Med 2015; 21:439-49. [PMID: 25998900 DOI: 10.1016/j.molmed.2015.04.005] [Citation(s) in RCA: 228] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 04/16/2015] [Accepted: 04/22/2015] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes (T2D) is a highly prevalent and chronic metabolic disorder. Recent evidence suggests that formation of toxic aggregates of the islet amyloid polypeptide (IAPP) might contribute to β-cell dysfunction and disease. However, the mechanism of protein aggregation and associated toxicity remains unclear. Misfolding, aggregation, and accumulation of diverse proteins in various organs is the hallmark of the group of protein misfolding disorders (PMDs), including highly prevalent illnesses affecting the central nervous system (CNS) such as Alzheimer's disease (AD) and Parkinson's disease (PD). In this review we discuss the current understanding of the mechanisms implicated in the formation of protein aggregates in the endocrine pancreas and associated toxicity in the light of the long-standing knowledge from neurodegenerative disorders associated with protein misfolding.
Collapse
Affiliation(s)
- Abhisek Mukherjee
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, TX 77030, USA
| | - Diego Morales-Scheihing
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, TX 77030, USA; Universidad de los Andes, Facultad de Medicina, Av. San Carlos de Apoquindo 2200, Las Condes, Santiago, Chile
| | - Peter C Butler
- Larry L. Hillblom Islet Research Center, University of California at Los Angeles, Los Angeles, CA, USA
| | - Claudio Soto
- Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, University of Texas Houston Medical School, Houston, TX 77030, USA.
| |
Collapse
|
22
|
Nguyen PT, Andraka N, De Carufel CA, Bourgault S. Mechanistic Contributions of Biological Cofactors in Islet Amyloid Polypeptide Amyloidogenesis. J Diabetes Res 2015; 2015:515307. [PMID: 26576436 PMCID: PMC4630397 DOI: 10.1155/2015/515307] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/26/2015] [Accepted: 02/09/2015] [Indexed: 01/24/2023] Open
Abstract
Type II diabetes mellitus is associated with the deposition of fibrillar aggregates in pancreatic islets. The major protein component of islet amyloids is the glucomodulatory hormone islet amyloid polypeptide (IAPP). Islet amyloid fibrils are virtually always associated with several biomolecules, including apolipoprotein E, metals, glycosaminoglycans, and various lipids. IAPP amyloidogenesis has been originally perceived as a self-assembly homogeneous process in which the inherent aggregation propensity of the peptide and its local concentration constitute the major driving forces to fibrillization. However, over the last two decades, numerous studies have shown a prominent role of amyloid cofactors in IAPP fibrillogenesis associated with the etiology of type II diabetes. It is increasingly evident that the biochemical microenvironment in which IAPP amyloid formation occurs and the interactions of the polypeptide with various biomolecules not only modulate the rate and extent of aggregation, but could also remodel the amyloidogenesis process as well as the structure, toxicity, and stability of the resulting fibrils.
Collapse
Affiliation(s)
- Phuong Trang Nguyen
- Department of Chemistry, Pharmaqam, University of Quebec in Montreal, Montreal, QC, Canada H3C 3P8
- Quebec Network for Research on Protein Function, Structure, and Engineering (PROTEO), Canada
| | - Nagore Andraka
- Department of Chemistry, Pharmaqam, University of Quebec in Montreal, Montreal, QC, Canada H3C 3P8
- Quebec Network for Research on Protein Function, Structure, and Engineering (PROTEO), Canada
- Biophysics Unit (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, 48080 Bilbao, Spain
| | - Carole Anne De Carufel
- Department of Chemistry, Pharmaqam, University of Quebec in Montreal, Montreal, QC, Canada H3C 3P8
- Quebec Network for Research on Protein Function, Structure, and Engineering (PROTEO), Canada
| | - Steve Bourgault
- Department of Chemistry, Pharmaqam, University of Quebec in Montreal, Montreal, QC, Canada H3C 3P8
- Quebec Network for Research on Protein Function, Structure, and Engineering (PROTEO), Canada
- *Steve Bourgault:
| |
Collapse
|
23
|
Gao M, Estel K, Seeliger J, Friedrich RP, Dogan S, Wanker EE, Winter R, Ebbinghaus S. Modulation of human IAPP fibrillation: cosolutes, crowders and chaperones. Phys Chem Chem Phys 2014; 17:8338-48. [PMID: 25406896 DOI: 10.1039/c4cp04682j] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cellular environment determines the structure and function of proteins. Marginal changes of the environment can severely affect the energy landscape of protein folding. However, despite the important role of chaperones on protein folding, less is known about chaperonal modulation of protein aggregation and fibrillation considering different classes of chaperones. We find that the pharmacological chaperone O4, the chemical chaperone proline as well as the protein chaperone serum amyloid P component (SAP) are inhibitors of the type 2 diabetes mellitus-related aggregation process of islet amyloid polypeptide (IAPP). By applying biophysical methods such as thioflavin T fluorescence spectroscopy, fluorescence anisotropy, total reflection Fourier-transform infrared spectroscopy, circular dichroism spectroscopy and atomic force microscopy we analyse and compare their inhibition mechanism. We demonstrate that the fibrillation reaction of human IAPP is strongly inhibited by formation of globular, amorphous assemblies by both, the pharmacological and the protein chaperones. We studied the inhibition mechanism under cell-like conditions by using the artificial crowding agents Ficoll 70 and sucrose. Under such conditions the suppressive effect of proline was decreased, whereas the pharmacological chaperone remains active.
Collapse
Affiliation(s)
- Mimi Gao
- Department of Physical Chemistry II, Ruhr-University Bochum, 44780 Bochum, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Wang H, Raleigh DP. The ability of insulin to inhibit the formation of amyloid by pro-islet amyloid polypeptide processing intermediates is significantly reduced in the presence of sulfated glycosaminoglycans. Biochemistry 2014; 53:2605-14. [PMID: 24654599 PMCID: PMC4010284 DOI: 10.1021/bi4015488] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
![]()
Islet
amyloid polypeptide (IAPP) is responsible for amyloid deposition
in type 2 diabetes and plays an important role in the loss of β-cell
mass associated with the disease and in the failure of islet transplants, but the mechanism of islet amyloid formation is not understood. The
incorrect processing of proIAPP to produce partially processed forms
of the peptide has been proposed to play a role in the initiation
of islet amyloid in vivo by promoting interactions
with proteoglycans of the extracellular matrix. Insulin is a potent
inhibitor of the formation of amyloid by IAPP in vitro in a homogeneous solution; however, its ability to inhibit IAPP
in the presence of proteoglycans has not been tested, nor has its
effect on the formation of amyloid by proIAPP processing intermediates
been examined. Here we show that insulin is a much less effective
amyloid inhibitor of both IAPP and proIAPP processing intermediates in vitro in the presence of model glycosaminoglycans, but
does inhibit the formation of amyloid by proIAPP processing intermediates
in a homogeneous solution. This highlights another mechanism by which
sulfated proteoglycans could enhance islet amyloid formation in vivo. Interactions with sulfated proteoglycans can directly
promote amyloid formation and can also significantly reduce the effectiveness
of natural inhibitors.
Collapse
Affiliation(s)
- Hui Wang
- Department of Chemistry, State University of New York at Stony Brook , Stony Brook, New York 11794-3400, United States
| | | |
Collapse
|
25
|
De Carufel CA, Nguyen PT, Sahnouni S, Bourgault S. New insights into the roles of sulfated glycosaminoglycans in islet amyloid polypeptide amyloidogenesis and cytotoxicity. Biopolymers 2013; 100:645-55. [DOI: 10.1002/bip.22243] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 03/11/2013] [Accepted: 03/17/2013] [Indexed: 01/16/2023]
Affiliation(s)
| | - Phuong Trang Nguyen
- Department of Chemistry; University of Québec in Montreal; Montreal QC H3C 3P8 Canada
| | - Sabrina Sahnouni
- Department of Chemistry; University of Québec in Montreal; Montreal QC H3C 3P8 Canada
| | - Steve Bourgault
- Department of Chemistry; University of Québec in Montreal; Montreal QC H3C 3P8 Canada
| |
Collapse
|
26
|
Wang H, Cao P, Raleigh DP. Amyloid formation in heterogeneous environments: islet amyloid polypeptide glycosaminoglycan interactions. J Mol Biol 2012; 425:492-505. [PMID: 23154166 DOI: 10.1016/j.jmb.2012.11.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/25/2012] [Accepted: 11/03/2012] [Indexed: 11/20/2022]
Abstract
Amyloid formation plays an important role in a broad range of diseases, and the search for amyloid inhibitors is an active area of research. Amyloid formation takes places in a heterogeneous environment in vivo with the potential for interactions with membranes and with components of the extracellular matrix. Naturally occurring amyloid deposits are associated with sulfated proteoglycans and other factors. However, the vast majority of in vitro assays of amyloid formation and amyloid inhibition are conducted in homogeneous solution where the potential for interactions with membranes or sulfated proteoglycans is lacking and it is possible that different results may be obtained in heterogeneous environments. We show that variants of islet amyloid polypeptide (IAPP), which are non-amyloidogenic in homogeneous solution, can be readily induced to form amyloid in the presence of glycosaminoglycans (GAGs). GAGs are found to be more effective than anionic lipid vesicles at inducing amyloid formation on a per-charge basis. Several known inhibitors of IAPP amyloid formation are shown to be less effective in the presence of GAGs.
Collapse
Affiliation(s)
- Hui Wang
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400, USA
| | | | | |
Collapse
|
27
|
Gomes MPB, Vieira TCRG, Cordeiro Y, Silva JL. The role of RNA in mammalian prion protein conversion. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:415-28. [PMID: 22095764 DOI: 10.1002/wrna.118] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Prion diseases remain a challenge to modern science in the 21st century because of their capacity for transmission without an encoding nucleic acid. PrP(Sc), the infectious and alternatively folded form of the PrP prion protein, is capable of self-replication, using PrP(C), the properly folded form of PrP, as a template. This process is associated with neuronal death and the clinical manifestation of prion-based diseases. Unfortunately, little is known about the mechanisms that drive this process. Over the last decade, the theory that a nucleic acid, such as an RNA molecule, might be involved in the process of prion structural conversion has become more widely accepted; such a nucleic acid would act as a catalyst rather than encoding genetic information. Significant amounts of data regarding the interactions of PrP with nucleic acids have created a new foundation for understanding prion conversion and the transmission of prion diseases. Our knowledge has been enhanced by the characterization of a large group of RNA molecules known as non-coding RNAs, which execute a series of important cellular functions, from transcriptional regulation to the modulation of neuroplasticity. The RNA-binding properties of PrP along with the competition with other polyanions, such as glycosaminoglycans and nucleic acid aptamers, open new avenues for therapy.
Collapse
Affiliation(s)
- Mariana P B Gomes
- Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Instituto de Bioquímica Médica, Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | |
Collapse
|
28
|
Jha S, Patil SM, Gibson J, Nelson CE, Alder NN, Alexandrescu AT. Mechanism of amylin fibrillization enhancement by heparin. J Biol Chem 2011; 286:22894-904. [PMID: 21555785 DOI: 10.1074/jbc.m110.215814] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We characterized the interaction of amylin with heparin fragments of defined length, which model the glycosaminoglycan chains associated with amyloid deposits found in type 2 diabetes. Binding of heparin fragments to the positively charged N-terminal half of monomeric amylin depends on the concentration of negatively charged saccharides but is independent of oligosaccharide length. By contrast, amylin fibrillogenesis has a sigmoidal dependence on heparin fragment length, with an enhancement observed for oligosaccharides longer than four monomers and a leveling off of effects beyond 12 monomers. The length dependence suggests that the negatively charged helical structure of heparin electrostatically complements the positively charged surface of the fibrillar amylin cross-β structure. Fluorescence resonance energy transfer and total internal reflection fluorescence microscopy experiments indicate that heparin associates with amylin fibrils, rather than enhancing fibrillogenesis catalytically. Short heparin fragments containing two- or eight-saccharide monomers protect against amylin cytotoxicity toward a MIN6 mouse cell model of pancreatic β-cells.
Collapse
Affiliation(s)
- Suman Jha
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269-3125, USA
| | | | | | | | | | | |
Collapse
|
29
|
Bourgault S, Solomon JP, Reixach N, Kelly JW. Sulfated glycosaminoglycans accelerate transthyretin amyloidogenesis by quaternary structural conversion. Biochemistry 2011; 50:1001-15. [PMID: 21194234 DOI: 10.1021/bi101822y] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glycosaminoglycans (GAGs), which are found in association with all extracellular amyloid deposits in humans, are known to accelerate the aggregation of various amyloidogenic proteins in vitro. However, the precise molecular mechanism(s) by which GAGs accelerate amyloidogenesis remains elusive. Herein, we show that sulfated GAGs, especially heparin, accelerate transthyretin (TTR) amyloidogenesis by quaternary structural conversion. The clustering of sulfate groups on heparin and its polymeric nature are essential features for accelerating TTR amyloidogenesis. Heparin does not influence TTR tetramer stability or TTR dissociation kinetics, nor does it alter the folded monomer-misfolded monomer equilibrium directly. Instead, heparin accelerates the conversion of preformed TTR oligomers into larger aggregates. The more rapid disappearance of monomeric TTR in the presence of heparin likely reflects the fact that the monomer-misfolded amyloidogenic monomer-oligomer-TTR fibril equilibria are all linked, a hypothesis that is strongly supported by the light scattering data. TTR aggregates prepared in the presence of heparin exhibit a higher resistance to trypsin and proteinase K proteolysis and a lower exposure of hydrophobic side chains comprising hydrophobic clusters, suggesting an active role for heparin in amyloidogenesis. Our data suggest that heparin accelerates TTR aggregation by a scaffold-based mechanism, in which the sulfate groups comprising GAGs interact primarily with TTR oligomers through electrostatic interactions, concentrating and orienting the oligomers, facilitating the formation of higher molecular weight aggregates. This model raises the possibility that GAGs may play a protective role in human amyloid diseases by interacting with proteotoxic oligomers and promoting their association into less toxic amyloid fibrils.
Collapse
Affiliation(s)
- Steve Bourgault
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | | | |
Collapse
|
30
|
Meng F, Raleigh DP. Inhibition of glycosaminoglycan-mediated amyloid formation by islet amyloid polypeptide and proIAPP processing intermediates. J Mol Biol 2010; 406:491-502. [PMID: 21195086 DOI: 10.1016/j.jmb.2010.12.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 12/14/2010] [Accepted: 12/20/2010] [Indexed: 02/07/2023]
Abstract
Islet amyloid polypeptide (IAPP; also known as amylin) is responsible for islet amyloid formation in type 2 diabetes, and IAPP-induced toxicity is believed to contribute to the loss of β-cell mass associated with the late stages of type 2 diabetes. Islet amyloid formation may also play a role in graft failure after transplantation. IAPP is produced as a prohormone, pro-islet amyloid polypeptide (proIAPP), and processed in the secretory granules of the pancreatic β-cells. Partially processed forms of proIAPP are found in amyloid deposits; most notable is a 48-residue intermediate, proIAPP(1-48), which includes the N-terminal pro-extension, but which has been properly processed at the C-terminus. Incomplete processing may play a role in islet amyloid formation by promoting interactions with sulfated proteoglycans of the extracellular matrix, which, in turn, promote amyloid formation. We show that acid fuchsin (3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid), a simple sulfonated triphenyl methyl derivative, is a potent inhibitor of amyloid formation by the proIAPP(1-48) intermediate. The more complicated triphenyl methane derivative fast green FCF {ethyl-[4-[[4-[ethyl-[(3-sulfophenyl)methyl]amino]phenyl]-(4-hydroxy-2-sulfophenyl)methylidene]-1-cyclohexa-2,5-dienylidene]-[(3-sulfophenyl)methyl]azanium} also inhibits amyloid formation by IAPP and the proIAPP processing intermediate. Both compounds inhibit amyloid formation by mixtures of the proIAPP intermediate and the model glycosaminoglycan heparan sulfate. Acid fuchsin also inhibits glycosaminoglycan-mediated amyloid formation by mature IAPP. The ability to inhibit amyloid formation is not simply due to the compounds being sulfonated, since the sulfonated inhibitor of amyloid-β, tramiprosate, is not an inhibitor of amyloid formation by proIAPP(1-48).
Collapse
Affiliation(s)
- Fanling Meng
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794-3400, USA
| | | |
Collapse
|
31
|
Ariga T, Miyatake T, Yu RK. Role of proteoglycans and glycosaminoglycans in the pathogenesis of Alzheimer's disease and related disorders: Amyloidogenesis and therapeutic strategies-A review. J Neurosci Res 2010; 88:2303-15. [DOI: 10.1002/jnr.22393] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
32
|
Khemtémourian L, Engel MFM, Kruijtzer JAW, Höppener JWM, Liskamp RMJ, Killian JA. The role of the disulfide bond in the interaction of islet amyloid polypeptide with membranes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2010; 39:1359-64. [PMID: 20052582 PMCID: PMC2903700 DOI: 10.1007/s00249-009-0572-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 12/03/2009] [Accepted: 12/14/2009] [Indexed: 11/24/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) forms amyloid fibrils in pancreatic islets of patients with type 2 diabetes mellitus. It has been suggested that the N-terminal part, which contains a conserved intramolecular disulfide bond between residues 2 and 7, interacts with membranes, ultimately leading to membrane damage and β-cell death. Here, we used variants of the hIAPP1–19 fragment and model membranes of phosphatidylcholine and phosphatidylserine (7:3, molar ratio) to examine the role of this disulfide in membrane interactions. We found that the disulfide bond has a minor effect on membrane insertion properties and peptide conformational behavior, as studied by monolayer techniques, 2H NMR, ThT-fluorescence, membrane leakage, and CD spectroscopy. The results suggest that the disulfide bond does not play a significant role in hIAPP–membrane interactions. Hence, the fact that this bond is conserved is most likely related exclusively to the biological activity of IAPP as a hormone.
Collapse
|
33
|
Heparan sulfate proteoglycans in amyloidosis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2010; 93:309-34. [PMID: 20807650 DOI: 10.1016/s1877-1173(10)93013-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Amyloidosis is a generic term for a group of diseases characterized by deposits in different organ systems of insoluble materials composed mainly of distinct fibrillar proteins named amyloid. Besides amyloid, heparan sulfate proteoglycan (HSPG), is commonly found in most amyloid deposits, suggesting that HS/HSPG may be functionally involved in the pathogenesis of amyloidosis. HS or HSPG is found to interact with a number of amyloid proteins, displaying a promoting effect on amyloid fibrilization in vitro. In addition, HS is reported to be involved in processing amyloid precursor proteins and mediate amyloid toxicity. Although little is known about the in vivo mechanisms regarding the codeposition of HS with amyloid proteins in different amyloid diseases, experiments carried out in animal models, especially in transgenic mouse model where HS molecular structure is modified, support an active role for HS in amyloidogenesis. Further experimental evidence is required to strengthen these in vivo findings at a molecular level. Animal models that express mutant forms of HS due to knockout of the enzymes involved in glycosaminoglycan (GAG) biosynthesis are expected to provide valuable tools for studying the implications of HS, as well as other GAGs, in amyloid disorders.
Collapse
|
34
|
Mishima T, Ohkuri T, Monji A, Kanemaru T, Abe Y, Ueda T. Residual Structures in the Acid-Unfolded States of Vλ6 Proteins Affect Amyloid Fibrillation. J Mol Biol 2009; 392:1033-43. [DOI: 10.1016/j.jmb.2009.07.078] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/27/2009] [Accepted: 07/27/2009] [Indexed: 10/20/2022]
|
35
|
Wang J, Rabenstein DL. Interaction of heparin and heparin-derived oligosaccharides with synthetic peptide analogues of the heparin-binding domain of heparin/heparan sulfate-interacting protein. Biochim Biophys Acta Gen Subj 2009; 1790:1689-97. [PMID: 19747524 DOI: 10.1016/j.bbagen.2009.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2009] [Revised: 08/23/2009] [Accepted: 09/04/2009] [Indexed: 11/18/2022]
Abstract
BACKGROUND Although protamine is effective as an antidote of heparin, there is a need to replace protamine due to its side effects. HIP peptide has been reported to neutralize the anticoagulant activity of heparin. The interaction of HIP analog peptides with heparin and heparin-derived oligosaccharides is investigated in this paper. METHODS Seven analogues of the heparin-binding domain of heparin/heparan sulfate-interacting protein (HIP) were synthesized, and their interaction with heparin was characterized by heparin affinity chromatography, isothermal titration calorimetry, and NMR. RESULTS NMR results indicate the imidazolium groups of the His side chains of histidine-containing Hip analog peptide interact site-specifically with heparin at pH 5.5. Heparin has identical affinities for HIP analog peptides of opposite chirality. Analysis by counterion condensation theory indicates the peptide AC-SRPKAKAKAKAKDQTK-NH2 makes on average approximately 3 ionic interactions with heparin that result in displacement of approximately 2 Na+ ions, and ionic interactions account for approximately 46% of the binding free energy at a Na+ concentration of 0.15 M. CONCLUSIONS The affinity of heparin for the peptides is strongly dependent on the nature of the cationic side chains and pH. The thermodynamic parameters measured for the interaction of HIP peptide analogs with heparin are strongly dependent on the peptide sequence and pH. GENERAL SIGNIFICANCE The information obtained in this research will be of use in the design of new agents for neutralization of the anticoagulant activity of heparin. The site-specific binding of protonated histidine side chains to heparin provides a molecular-level explanation for the pH-dependent binding of beta-amyloid peptides by heparin and heparan sulfate proteoglycan and may have implications for amyloid formation.
Collapse
Affiliation(s)
- Jing Wang
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | | |
Collapse
|
36
|
Abedini A, Raleigh DP. A critical assessment of the role of helical intermediates in amyloid formation by natively unfolded proteins and polypeptides. Protein Eng Des Sel 2009; 22:453-9. [PMID: 19596696 DOI: 10.1093/protein/gzp036] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Amyloidogenic proteins and polypeptides can be divided into two structural classes, namely those which are flexible and are intrinsically disordered in their unaggregated state and those which form a compact globular structure with a well-defined tertiary fold in their normally soluble state. This review article is focused on amyloid formation by natively disordered polypeptides. Important examples of this class include islet amyloid polypeptide (IAPP, amylin), pro-IAPP processing intermediates, alpha-synuclein, the Abeta peptide, atrial natriuretic factor, calcitonin, pro-calcitonin, the medin polypeptide, as well as a range of de novo designed peptides. Amyloid formation is a complex process consisting of a lag phase during which no detectable fibril material is formed, followed by a rapid growth phase that leads to amyloid fibrils. A critical analysis of the literature suggests that a subset of intrinsically disordered polypeptides populate a helical intermediate during the lag phase. In this scenario, early formation of multimeric species is promoted by helix-helix association involving one region of the polypeptide chain which leads to a high effective concentration of an amyloidogenic sequence located in a different region of the chain. Helical intermediates appear to be particularly important in membrane-catalyzed amyloid formation and have been implicated in glycosaminoglycan mediated amyloid formation as well. There is suggestive evidence that targeting helix-helix interactions can be a viable strategy to inhibit amyloid formation. The characterization of transient helical intermediates is challenging, but new methods are being developed that offer the prospect of providing residue-specific information in real time.
Collapse
Affiliation(s)
- Andisheh Abedini
- Division of Surgical Science, Department of Surgery, College of Physicians and Surgeons, Columbia University, New York, NY 11794, USA.
| | | |
Collapse
|
37
|
Abedini A, Raleigh DP. A role for helical intermediates in amyloid formation by natively unfolded polypeptides? Phys Biol 2009; 6:015005. [PMID: 19208933 DOI: 10.1088/1478-3975/6/1/015005] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Amyloid formation and aberrant protein aggregation have been implicated in more than 15 different human diseases and an even wider range of proteins form amyloid in vitro. From a structural perspective the proteins which form amyloid can be divided into two classes: those which adopt a compact globular fold and must presumably at least partially unfold to form amyloid and those which are unstructured in their monomeric state. Important examples of the latter include the Abeta peptide of Alzheimer's disease, atrial natriuretic factor, calcitonin, pro-calcitonin, islet amyloid polypeptide (IAPP, amylin), alpha-synuclein and the medin polypeptide. The kinetics of amyloid assembly are complex and typically involve a lag phase during which little or no fibril material is formed, followed by a rapid growth stage leading to the beta-sheet-rich amyloid structure. Increasing evidence suggests that some natively unfolded polypeptides populate a helical intermediate during the lag phase. We propose a model in which early oligomerization is linked to helix formation and is promoted by helix-helix association. Recent work has highlighted the potential importance of polypeptide membrane interactions in amyloid formation and helical intermediates appear to play an important role here as well. Characterization of helical intermediates is experimentally challenging but new spectroscopic techniques are emerging which hold considerable promise and even have the potential to provide residue specific information.
Collapse
Affiliation(s)
- Andisheh Abedini
- Joslin Diabetes Center, Division of Cellular and Molecular Physiology, Harvard Medical School, One Joslin Place, Boston, MA 02250, USA.
| | | |
Collapse
|
38
|
Lindahl U, Li JP. Interactions between heparan sulfate and proteins-design and functional implications. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 276:105-59. [PMID: 19584012 DOI: 10.1016/s1937-6448(09)76003-4] [Citation(s) in RCA: 206] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heparan sulfate (HS) proteoglycans at cell surfaces and in the extracellular matrix of most animal tissues are essential in development and homeostasis, and variously implicated in disease processes. Functions of HS polysaccharide chains depend on ionic interactions with a variety of proteins including growth factors and their receptors. Negatively charged sulfate and carboxylate groups are arranged in various types of domains, generated through strictly regulated biosynthetic reactions and with enormous potential for structural variability. The level of specificity of HS-protein interactions is assessed through binding experiments in vitro using saccharides of defined composition, signaling assays in cell culture, and targeted disruption of genes for biosynthetic enzymes followed by phenotype analysis. While some protein ligands appear to require strictly defined HS structure, others bind to variable saccharide domains without any apparent dependence on distinct saccharide sequence. These findings raise intriguing questions concerning the functional significance of regulation in HS biosynthesis.
Collapse
Affiliation(s)
- Ulf Lindahl
- Department of Medical Biochemistry and Microbiology, University of Uppsala, Uppsala, Sweden
| | | |
Collapse
|
39
|
Bellotti V, Chiti F. Amyloidogenesis in its biological environment: challenging a fundamental issue in protein misfolding diseases. Curr Opin Struct Biol 2008; 18:771-9. [DOI: 10.1016/j.sbi.2008.10.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Accepted: 10/15/2008] [Indexed: 10/21/2022]
|
40
|
Abedini A, Meng F, Raleigh DP. A single-point mutation converts the highly amyloidogenic human islet amyloid polypeptide into a potent fibrillization inhibitor. J Am Chem Soc 2007; 129:11300-1. [PMID: 17722920 DOI: 10.1021/ja072157y] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andisheh Abedini
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA
| | | | | |
Collapse
|