1
|
Wang Y, Liu Y, Zhang Y, Wei G, Ding F, Sun Y. Molecular insights into the oligomerization dynamics and conformations of amyloidogenic and non-amyloidogenic amylin from discrete molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:21773-21785. [PMID: 36098068 PMCID: PMC9623603 DOI: 10.1039/d2cp02851d] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
The amyloid aggregation of human islet amyloid polypeptide (hIAPP) is associated with pancreatic β-cell death in type 2 diabetes. The S20G substitution of hIAPP (hIAPP(S20G)), found in Japanese and Chinese people, is more amyloidogenic and cytotoxic than wild-type hIAPP. Rat amylin (rIAPP) does not have aggregation propensity or cytotoxicity. Mounting evidence suggests that soluble low-molecular-weight amyloid oligomers formed during early aggregation are more cytotoxic than mature fibrils. The self-assembly dynamics and oligomeric conformations remain unknown because the oligomers are heterogeneous and transient. The molecular mechanism of sequence-variation rendering dramatically different aggregation propensity and cytotoxicity is also elusive. Here, we investigate the oligomerization dynamics and conformations of amyloidogenic hIAPP, hIAPP(S20G), and non-amyloidogenic rIAPP using atomistic discrete molecular dynamics (DMD) simulations. Our simulation results demonstrated that all three monomeric amylin peptides mainly adopted an unstructured formation with partial dynamical helices near the N-terminus. Relatively transient β-hairpins were more abundant in hIAPP and hIAPP(S20G) than in rIAPP. The S20G-substituting mutant of hIAPP altered the turn region of the β-hairpin motif, resulting in more hydrophobic residue-pairwise contacts within the β-hairpin. Oligomerization dynamic investigation revealed that all three peptides spontaneously accumulated into helix-populated oligomers. The conformational conversion to form β-sheet-rich oligomers was only observed in hIAPP and hIAPP(S20G). The population of high-β-sheet-content oligomers was enhanced by S20G substitution. Interestingly, both hIAPP and hIAPP(S20G) could form β-barrel formations, and the β-barrel propensity of hIAPP(S20G) was three times larger than that of hIAPP. No β-sheet-rich or β-barrel formations were observed in rIAPP. Our direct observation of the correlation between β-barrel oligomer formation and cytotoxicity suggests that β-barrels might play a critically important role in the cytotoxicity of amyloidosis.
Collapse
Affiliation(s)
- Ying Wang
- Department of Physics, Ningbo University, Ningbo 315211, China.
| | - Yuying Liu
- Department of Physics, Ningbo University, Ningbo 315211, China.
| | - Yu Zhang
- Department of Physics, Ningbo University, Ningbo 315211, China.
| | - Guanghong Wei
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Yunxiang Sun
- Department of Physics, Ningbo University, Ningbo 315211, China.
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| |
Collapse
|
2
|
Tang Y, Zhang D, Liu Y, Zhang Y, Zhou Y, Chang Y, Zheng B, Xu A, Zheng J. A new strategy to reconcile amyloid cross-seeding and amyloid prevention in a binary system of α-synuclein fragmental peptide and hIAPP. Protein Sci 2022; 31:485-497. [PMID: 34850985 PMCID: PMC8820123 DOI: 10.1002/pro.4247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 02/03/2023]
Abstract
Amyloid cross-seeding and amyloid inhibition are two different research subjects being studied separately for different pathological purposes, in which amyloid cross-seeding targets to study the co-aggregation of different amyloid proteins and potential molecular links between different neurodegenerative diseases, while amyloid inhibition aims to design different molecules for preventing amyloid aggregation. While both amyloid cross-seeding and amyloid inhibition are critical for better understanding the pathological causes of different neurodegenerative diseases including Parkinson disease (PD) and Type 2 diabetes (T2D), less efforts have been made to reconcile the two phenomena. Herein, we proposed a new preventive strategy to demonstrate (a) the cross-seeding of octapeptide TKEQVTNV from α-synuclein (associated with PD) with hIAPP (associated with T2D) and (b) the cross-seeding-promoted hIAPP fibrillization and cross-seeding-reduced hIAPP toxicity. Collective results confirmed that TKEQVTNV can indeed cross-seed with hIAPP monomers and oligomers, not protofibrils, to form β-structure-rich fibrils and to accelerate hIAPP fibrillization. Moreover, such cross-seeding-induced promotion effect by TKEQVTNV also rescued the pancreatic cells from hIAPP-induced cytotoxicity by increasing cell viability and reducing cell apoptosis simultaneously. This work provides a new angle to discover amyloid fragments and use them as amyloid modulators (inhibitors or promotors) to interfere with amyloid aggregation of other amyloid proteins, as well as sequence/structure basis to explore the amyloid cross-seeding between different amyloid proteins that may help explain a potential molecular talk between different neurodegenerative diseases.
Collapse
Affiliation(s)
- Yijing Tang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Dong Zhang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yonglan Liu
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yanxian Zhang
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| | - Yifan Zhou
- Department of Polymer ScienceThe University of AkronAkronOhioUSA
| | - Yung Chang
- R&D Center for Membrane Technology, Department of Chemical EngineeringChung Yuan Christian UniversityTaoyuanTaiwan
| | | | | | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion EngineeringThe University of AkronAkronOhioUSA
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Hao X, Zheng J, Sun Y, Dong X. Seeding and Cross-Seeding Aggregations of Aβ 40 and Its N-Terminal-Truncated Peptide Aβ 11-40. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2821-2831. [PMID: 30681866 DOI: 10.1021/acs.langmuir.8b03599] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In the amyloid plaques of Alzheimer's disease (AD) patients, a large number of N-terminal-truncated amyloid β (Aβ) peptides such as Aβ11-40 have been identified in addition to the full-length Aβ peptides. However, little is known about the roles of the N-terminal-truncated peptides in AD pathological process. Herein, seeding and cross-seeding aggregations of Aβ40 and its N-terminal-truncated Aβ11-40 were investigated in the solution and on the surfaces of chips with immobilized seeds by extensive biophysical and biological analyses. The results showed that Aβ40 and Aβ11-40 aggregates could seed both homologous and heterologous aggregations of the two monomers. However, the capability and characteristics of the seeding (homologous aggregation) and cross-seeding (heterologous aggregation) were significantly different. Aβ40 seeds showed stronger acceleration effects on the aggregations than Aβ11-40 seeds and induced β-sheet-rich fibrous aggregates of similar cytotoxicities for the two monomers. This indicates that Aβ40 and Aβ11-40 had similar aggregation pathways in the seeding and cross-seeding on Aβ40 seeds. By contrast, Aβ11-40 seeds led to different aggregation pathways of Aβ40 and Aβ11-40. Pure Aβ11-40 aggregates had higher toxicity than Aβ40 aggregates, and as seeds, Aβ11-40 seeds induced Aβ40 to form aggregates of higher cytotoxicity. However, homologous Aβ11-40 aggregates induced by Aβ11-40 seeds showed lower cytotoxicity than pure Aβ11-40 aggregates. The results suggest that Aβ11-40 plays an important role in the pathological process of AD.
Collapse
Affiliation(s)
- Xiuping Hao
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering , The University of Akron , Akron , Ohio 44325 , United States
| | - Yan Sun
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Xiaoyan Dong
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| |
Collapse
|
5
|
Zhang M, Zheng J, Nussinov R, Ma B. Molecular Recognition between Aβ-Specific Single-Domain Antibody and Aβ Misfolded Aggregates. Antibodies (Basel) 2018; 7:E25. [PMID: 31544877 PMCID: PMC6640678 DOI: 10.3390/antib7030025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/06/2018] [Accepted: 07/09/2018] [Indexed: 12/12/2022] Open
Abstract
Aβ is the toxic amyloid polypeptide responsible for Alzheimer's disease (AD). Prevention and elimination of the Aβ misfolded aggregates are the promising therapeutic strategies for the AD treatments. Gammabody, the Aβ-Specific Single-domain (VH) antibody, recognizes Aβ aggregates with high affinity and specificity and reduces their toxicities. Employing the molecular dynamics simulations, we studied diverse gammabody-Aβ recognition complexes to get insights into their structural and dynamic properties and gammabody-Aβ recognitions. Among many heterogeneous binding modes, we focused on two gammabody-Aβ recognition scenarios: recognition through Aβ β-sheet backbone and on sidechain surface. We found that the gammabody primarily uses the complementarity-determining region 3 (CDR3) loop with the grafted Aβ sequence to interact with the Aβ fibril, while CDR1/CDR2 loops have very little contact. The gammabody-Aβ complexes with backbone binding mode are more stable, explaining the gammabody's specificity towards the C-terminal Aβ sequence.
Collapse
Affiliation(s)
- Mingzhen Zhang
- Department of Chemical & Biomolecular Engineering, the University of Akron, Akron, OH 44325, USA.
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
| | - Jie Zheng
- Department of Chemical & Biomolecular Engineering, the University of Akron, Akron, OH 44325, USA.
| | - Ruth Nussinov
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Buyong Ma
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
| |
Collapse
|
6
|
Tofoleanu F, Yuan Y, Pickard FC, Tywoniuk B, Brooks BR, Buchete NV. Structural Modulation of Human Amylin Protofilaments by Naturally Occurring Mutations. J Phys Chem B 2018; 122:5657-5665. [PMID: 29406755 DOI: 10.1021/acs.jpcb.7b12083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human islet amyloid polypeptide (hIAPP), also known as amylin, is a 37-amino-acid peptide, co-secreted with insulin, and widely found in fibril form in type-2 diabetes patients. By using all-atom molecular dynamics simulations, we study hIAPP fibril segments (i.e., fibrillar oligomers) formed with sequences of naturally occurring variants from cat, rat, and pig, presenting different aggregation propensities. We characterize the effect of mutations on the structural dynamics of solution-formed hIAPP fibril models built from solid-state NMR data. Results from this study are in agreement with experimental observations regarding their respective relative aggregation propensities. We analyze in detail the specific structural characteristics and infer mechanisms that modulate the conformational stability of amylin fibrils. Results provide a platform for further studies and the design of new drugs that could interfere with amylin aggregation and its cytotoxicity. One particular mutation, N31K, has fibril-destabilizing properties, and could potentially improve the solubility of therapeutic amylin analogs.
Collapse
Affiliation(s)
- Florentina Tofoleanu
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute , National Institutes of Health , Bethesda , Maryland 20892 , United States.,Department of Chemistry , Yale University , New Haven , Connecticut 06520 , United States
| | - Ye Yuan
- Institute for Discovery , University College Dublin , Belfield, Dublin 4 , Ireland.,School of Physics , University College Dublin , Dublin 4 , Ireland
| | - Frank C Pickard
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute , National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Bartłomiej Tywoniuk
- Institute for Discovery , University College Dublin , Belfield, Dublin 4 , Ireland.,School of Physics , University College Dublin , Dublin 4 , Ireland
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute , National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Nicolae-Viorel Buchete
- Institute for Discovery , University College Dublin , Belfield, Dublin 4 , Ireland.,School of Physics , University College Dublin , Dublin 4 , Ireland
| |
Collapse
|
7
|
Liu Y, Ren B, Zhang Y, Sun Y, Chang Y, Liang G, Xu L, Zheng J. Molecular simulation aspects of amyloid peptides at membrane interface. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1906-1916. [PMID: 29421626 DOI: 10.1016/j.bbamem.2018.02.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/31/2018] [Accepted: 02/01/2018] [Indexed: 12/13/2022]
Abstract
The interactions of amyloid peptides with cell membranes play an important role in maintaining the integrity and functionality of cell membrane. A thorough molecular-level understanding of the structure, dynamics, and interactions between amyloid peptides and cell membranes is critical to amyloid aggregation and toxicity mechanisms for the bench-to-bedside applications. Here we review the most recent computational studies of amyloid peptides at model cell membranes. Different mechanisms of action of amyloid peptides on/in cell membranes, targeted by different computational techniques at different lengthscales and timescales, are rationally discussed. Finally, we have proposed some new insights into the remaining challenges and perspectives for future studies to improve our understanding of the activity of amyloid peptides associated with protein-misfolding diseases. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
Collapse
Affiliation(s)
- Yonglan Liu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, PR China; Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Baiping Ren
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Yanxian Zhang
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States
| | - Yan Sun
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical EngineeringChung Yuan Christian University, Chung-Li, Taoyuan 320, Taiwan
| | - Guizhao Liang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044, PR China
| | - Lijian Xu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, PR China; Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States.
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH 44325, United States.
| |
Collapse
|
8
|
Ren B, Hu R, Zhang M, Liu Y, Xu L, Jiang B, Ma J, Ma B, Nussinov R, Zheng J. Experimental and Computational Protocols for Studies of Cross-Seeding Amyloid Assemblies. Methods Mol Biol 2018; 1777:429-447. [PMID: 29744852 PMCID: PMC6456059 DOI: 10.1007/978-1-4939-7811-3_27] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) and type 2 diabetes (T2D) are two common protein aggregation diseases. Compelling evidence has shown a link between AD and T2D, which may derive from interspecies cross-sequence interactions between amyloid-β peptide (Aβ), associated with AD, and human islet amyloid polypeptide (hIAPP), associated with T2D. Herein, we present experimental and computational protocols and tools to study the aggregate structures and kinetics, conformational conversion, and molecular interactions of Aβ-hIAPP mixtures. These protocols could be generally applied to other cross-seeding behaviors of amyloid peptides.
Collapse
Affiliation(s)
- Baiping Ren
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
| | - Rundong Hu
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
| | - Mingzhen Zhang
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
| | - Yonglan Liu
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
| | - Lijian Xu
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
- College of Life Sciences and Chemistry Hunan University of Technology, Zhuzhou, China
| | - Binbo Jiang
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
- College of Chemical and Biological Engineering, Zhejiang University, Zhejiang, Hangzhou, China
| | - Jie Ma
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, China
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD, USA
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD, USA.
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Jie Zheng
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, OH, USA.
| |
Collapse
|
9
|
Ly H, Verma N, Wu F, Liu M, Saatman KE, Nelson PT, Slevin JT, Goldstein LB, Biessels GJ, Despa F. Brain microvascular injury and white matter disease provoked by diabetes-associated hyperamylinemia. Ann Neurol 2017; 82:208-222. [PMID: 28696548 DOI: 10.1002/ana.24992] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/20/2017] [Accepted: 07/03/2017] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The brain blood vessels of patients with type 2 diabetes and dementia have deposition of amylin, an amyloidogenic hormone cosecreted with insulin. It is not known whether vascular amylin deposition is a consequence or a trigger of vascular injury. We tested the hypothesis that the vascular amylin deposits cause endothelial dysfunction and microvascular injury and are modulated by amylin transport in the brain via plasma apolipoproteins. METHODS Rats overexpressing amyloidogenic (human) amylin in the pancreas (HIP rats) and amylin knockout (AKO) rats intravenously infused with aggregated amylin were used for in vivo phenotyping. We also carried out biochemical analyses of human brain tissues and studied the effects of the aggregated amylin on endothelial cells ex vivo. RESULTS Amylin deposition in brain blood vessels is associated with vessel wall disruption and abnormal surrounding neuropil in patients with type 2 diabetes and dementia, in HIP rats, and in AKO rats infused with aggregated amylin. HIP rats have brain microhemorrhages, white matter injury, and neurologic deficits. Vascular amylin deposition provokes loss of endothelial cell coverage and tight junctions. Intravenous infusion in AKO rats of human amylin, or combined human amylin and apolipoprotein E4, showed that amylin binds to plasma apolipoproteins. The intravenous infusion of apolipoprotein E4 exacerbated the brain accumulation of aggregated amylin and vascular pathology in HIP rats. INTERPRETATION These data identify vascular amylin deposition as a trigger of brain endothelial dysfunction that is modulated by plasma apolipoproteins and represents a potential therapeutic target in diabetes-associated dementia and stroke. Ann Neurol 2017;82:208-222.
Collapse
Affiliation(s)
- Han Ly
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Nirmal Verma
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Fengen Wu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Miao Liu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Kathryn E Saatman
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY.,Department of Physiology, University of Kentucky, Lexington, KY
| | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY
| | - John T Slevin
- Veterans Administration Medical Center, Lexington, KY.,Department of Neurology, University of Kentucky, Lexington, KY
| | | | - Geert Jan Biessels
- Department of Neurology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY.,Department of Neurology, University of Kentucky, Lexington, KY
| |
Collapse
|
10
|
Guo J, Yu L, Sun Y, Dong X. Kinetic Insights into Zn2+-Induced Amyloid β-Protein Aggregation Revealed by Stopped-Flow Fluorescence Spectroscopy. J Phys Chem B 2017; 121:3909-3917. [DOI: 10.1021/acs.jpcb.6b12187] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Jingjing Guo
- Department of Biochemical
Engineering and Key Laboratory of Systems Bioengineering of the Ministry
of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Linling Yu
- Department of Biochemical
Engineering and Key Laboratory of Systems Bioengineering of the Ministry
of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yan Sun
- Department of Biochemical
Engineering and Key Laboratory of Systems Bioengineering of the Ministry
of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Xiaoyan Dong
- Department of Biochemical
Engineering and Key Laboratory of Systems Bioengineering of the Ministry
of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| |
Collapse
|
11
|
Raynes JK, Day L, Crepin P, Horrocks MH, Carver JA. Coaggregation of κ-Casein and β-Lactoglobulin Produces Morphologically Distinct Amyloid Fibrils. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1603591. [PMID: 28146312 DOI: 10.1002/smll.201603591] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/20/2016] [Indexed: 06/06/2023]
Abstract
The unfolding, misfolding, and aggregation of proteins lead to a variety of structural species. One form is the amyloid fibril, a highly aligned, stable, nanofibrillar structure composed of β-sheets running perpendicular to the fibril axis. β-Lactoglobulin (β-Lg) and κ-casein (κ-CN) are two milk proteins that not only individually form amyloid fibrillar aggregates, but can also coaggregate under environmental stress conditions such as elevated temperature. The aggregation between β-Lg and κ-CN is proposed to proceed via disulfide bond formation leading to amorphous aggregates, although the exact mechanism is not known. Herein, using a range of biophysical techniques, it is shown that β-Lg and κ-CN coaggregate to form morphologically distinct co-amyloid fibrillar structures, a phenomenon previously limited to protein isoforms from different species or different peptide sequences from an individual protein. A new mechanism of aggregation is proposed whereby β-Lg and κ-CN not only form disulfide-linked aggregates, but also amyloid fibrillar coaggregates. The coaggregation of two structurally unrelated proteins into cofibrils suggests that the mechanism can be a generic feature of protein aggregation as long as the prerequisites for sequence similarity are met.
Collapse
Affiliation(s)
- Jared K Raynes
- CSIRO Agriculture and Food, Werribee, Victoria, 3031, Australia
| | - Li Day
- AgResearch Limited, Grasslands Research Centre, Tennent Drive, Palmerston North, 4442, New Zealand
| | - Pauline Crepin
- École Nationale Supérieure de Chimie, Biologie et Physique, Bordeaux, 33607, France
| | - Mathew H Horrocks
- Proteostasis and Disease Research Centre, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, 2522, Australia
| | - John A Carver
- Research School of Chemistry, The Australian National University, Acton, Australian Capital Territory, 2601, Australia
| |
Collapse
|
12
|
Hu R, Ren B, Zhang M, Chen H, Liu Y, Liu L, Gong X, Jiang B, Ma J, Zheng J. Seed-Induced Heterogeneous Cross-Seeding Self-Assembly of Human and Rat Islet Polypeptides. ACS OMEGA 2017; 2:784-792. [PMID: 30023616 PMCID: PMC6044775 DOI: 10.1021/acsomega.6b00559] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 02/20/2017] [Indexed: 05/30/2023]
Abstract
Amyloid peptides can misfold and aggregate into amyloid oligomers and fibrils containing conformationally similar β-sheet structures, which are linked to the pathological hallmark of many neurodegenerative diseases. These β-sheet-rich amyloid aggregates provide common structural motifs to accelerate amyloid formation by acting as seeds. However, little is known about how one amyloid peptide aggregation will affect another one (namely, cross-seeding). In this work, we studied the cross-seeding possibility and efficiency between rat islet amyloid polypeptide (rIAPP) and human islet amyloid polypeptide (hIAPP) solution with preformed aggregates at different aggregation phases, using a combination of different biophysical techniques. hIAPP is a well-known peptide hormone that forms amyloid fibrils and induces cytotoxicity to β-cells in type 2 diabetes, whereas rIAPP is a nonaggregating and nontoxic peptide. Experimental results showed that all different preformed hIAPP aggregates can cross-seed rIAPP to promote the final fibril formation but exhibit different cross-seeding efficiencies. Evidently, hIAPP seeds preformed at a growth phase show the strongest cross-seeding potential to rIAPP, which accelerates the conformational transition from random structures to β-sheet and the aggregation process at the fibrillization stage. Homoseeding of hIAPP is more efficient in initiating and promoting aggregation than cross-seeding of hIAPP and rIAPP. Moreover, the cross-seeding of rIAPP with hIAPP at the lag phase also reduced cell viability, probably because of the formation of more toxic hybrid oligomers at the prolonged lag phase. The cross-seeding effects in this work may add new insights into the mechanistic understanding of the aggregation and coaggregation of amyloid peptides linked to different neurodegenerative diseases.
Collapse
Affiliation(s)
- Rundong Hu
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Baiping Ren
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Mingzhen Zhang
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Hong Chen
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Yonglan Liu
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Lingyun Liu
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Xiong Gong
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Binbo Jiang
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
- College
of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Jie Ma
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
Environmental Science and Engineering, Tongji
University, Shanghai 200092, China
| | - Jie Zheng
- Department
of Chemical and Biomolecular Engineering and College of Polymer Science and
Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| |
Collapse
|
13
|
Zhang M, Ren B, Chen H, Sun Y, Ma J, Jiang B, Zheng J. Molecular Simulations of Amyloid Structures, Toxicity, and Inhibition. Isr J Chem 2016. [DOI: 10.1002/ijch.201600075] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Mingzhen Zhang
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
| | - Baiping Ren
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
| | - Hong Chen
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
| | - Yan Sun
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology Tianjin University Tianjin 300072 P. R. China
| | - Jie Ma
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
- State Key Laboratory of Pollution Control and Resource Reuse School of Environmental Science and Engineering Tongji University Shanghai 200092 P. R. China
| | - Binbo Jiang
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
- College of Chemical and Biological Engineering Zhejiang University Hangzhou Zhejiang 310027 P. R. China
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA
| |
Collapse
|
14
|
Zhang M, Hu R, Chen H, Chang Y, Ma J, Liang G, Mi J, Wang Y, Zheng J. Polymorphic cross-seeding amyloid assemblies of amyloid-β and human islet amyloid polypeptide. Phys Chem Chem Phys 2015; 17:23245-56. [PMID: 26283068 DOI: 10.1039/c5cp03329b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Epidemiological studies have shown that the development of Alzheimer's disease (AD) is associated with type 2 diabetes (T2D), but it still remains unclear how AD and T2D are connected. Heterologous cross-seeding between the causative peptides of Aβ and hIAPP may represent a molecular link between AD and T2D. Here, we computationally modeled and simulated a series of cross-seeding double-layer assemblies formed by Aβ and hIAPP peptides using all-atom and coarse-gained molecular dynamics (MD) simulations. The cross-seeding Aβ-hIAPP assemblies showed a wide range of polymorphic structures via a combination of four β-sheet-to-β-sheet interfaces and two packing orientations, focusing on a comparison of different matches of β-sheet layers. Two cross-seeding Aβ-hIAPP assemblies with different interfacial β-sheet packings exhibited high structural stability and favorable interfacial interactions in both oligomeric and fibrillar states. Both Aβ-hIAPP assemblies displayed interfacial dehydration to different extents, which in turn promoted Aβ-hIAPP association depending on interfacial polarity and geometry. Furthermore, computational mutagenesis studies revealed that disruption of interfacial salt bridges largely disfavor the β-sheet-to-β-sheet association, highlighting the importance of salt bridges in the formation of cross-seeding assemblies. This work provides atomic-level information on the cross-seeding interactions between Aβ and hIAPP, which may be involved in the interplay between these two disorders.
Collapse
Affiliation(s)
- Mingzhen Zhang
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Zhang M, Hu R, Chen H, Gong X, Zhou F, Zhang L, Zheng J. Polymorphic Associations and Structures of the Cross-Seeding of Aβ1–42 and hIAPP1–37 Polypeptides. J Chem Inf Model 2015; 55:1628-39. [DOI: 10.1021/acs.jcim.5b00166] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
| | | | | | | | - Feimeng Zhou
- Department
of Chemistry and Biochemistry, California State University, Los Angeles, Los Angeles, California 90032, United States
| | - Li Zhang
- Department
of Geriatric Neurology, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | | |
Collapse
|
16
|
Zhang M, Hu R, Chen H, Chang Y, Gong X, Liu F, Zheng J. Interfacial interaction and lateral association of cross-seeding assemblies between hIAPP and rIAPP oligomers. Phys Chem Chem Phys 2015; 17:10373-82. [DOI: 10.1039/c4cp05658b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cross-sequence interactions between different amyloid peptides are important not only for fundamental understanding of amyloid aggregation and polymorphism mechanisms, but also for probing a potential molecular link between different amyloid diseases.
Collapse
Affiliation(s)
- Mingzhen Zhang
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
| | - Rundong Hu
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
| | - Hong Chen
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical Engineering
- Chung Yuan University
- Taoyuan 320
- Taiwan
| | - Xiong Gong
- College of Polymer Science and Polymer Engineering
- The University of Akron
- Akron
- USA
| | - Fufeng Liu
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering (Ministry of Education)
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Jie Zheng
- Department of Chemical and Biomolecular Engineering
- The University of Akron
- Akron
- USA
| |
Collapse
|
17
|
Wineman-Fisher V, Atsmon-Raz Y, Miller Y. Orientations of residues along the β-arch of self-assembled amylin fibril-like structures lead to polymorphism. Biomacromolecules 2014; 16:156-65. [PMID: 25420121 DOI: 10.1021/bm501326y] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amylin is an endocrine hormone peptide that consists of 37 residues and is the main component of extracellular amyloid deposits found in the pancreas of most type 2 diabetes patients. Amylin peptides are self-assembled to form oligomers and fibrils. So far, four different molecular structures of the self-assembled amylin fibrils have been observed experimentally: two ssNMR models and two crystal models. This study reveals, for the first time, that there are four self-assembled amylin forms that differ in the orientations of the side chains along the β-arch and are all derived from the two ssNMR models. The two ssNMR models are composed of these four different self-assembled forms of amylin, and the two crystal models are composed of two different self-assembled forms of amylin. This study illustrates at the atomic level the differences among the four experimental models and proposes eight new models of self-assembled amylin that are also composed of the four different self-assembled forms of amylin. Our results show polymorphism of the self-assembled fibril-like amylin, with a slight preference of some of the newly constructed models over the experimental models. Finally, we propose that two different self-assembled fibril-like forms of amylin can interact to form a new fibril-like amylin. We investigated this argument and found that some fibril-like amylin prefers to interact to form stable fibril-like structures, whereas others disfavor it. Our work provides new insights that may suggest strategies for future pharmacological studies that aim to find ways to ameliorate the interactions between polymorphic oligomers and fibrils of amylin.
Collapse
Affiliation(s)
- Vered Wineman-Fisher
- Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev , Beer-Sheva 84105, Israel
| | | | | |
Collapse
|
18
|
Wang Q, Liang G, Zhang M, Zhao J, Patel K, Yu X, Zhao C, Ding B, Zhang G, Zhou F, Zheng J. De novo design of self-assembled hexapeptides as β-amyloid (Aβ) peptide inhibitors. ACS Chem Neurosci 2014; 5:972-81. [PMID: 25133634 DOI: 10.1021/cn500165s] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The ability of peptides to construct specific secondary structures provides a useful function for biomaterial design that cannot be achieved with traditional organic molecules and polymers. Inhibition of amyloid formation is a promising therapeutic approach for the treatment of neurodegenerative diseases. Existing peptide-based inhibitors are mainly derived from original amyloid sequences, which have very limited sequence diversity and activity. It is highly desirable to explore other peptide-based inhibitors that are not directly derived from amyloid sequences. Here, we develop a hybrid high-throughput computational method to efficiently screen and design hexapeptide inhibitors against amyloid-β (Aβ) aggregation and toxicity from the first principle. Computationally screened/designed inhibitors are then validated for their inhibition activity using biophysical experiments. We propose and demonstrate a proof-of-concept of the "like-interacts-like" design principle that the self-assembling peptides are able to interact strongly with conformationally similar motifs of Aβ peptides and to competitively reduce Aβ-Aβ interactions, thus preventing Aβ aggregation and Aβ-induced toxicity. Such a de novo design can also be generally applicable to design new peptide inhibitors against other amyloid diseases, beyond traditional peptide inhibitors with homologous sequences to parent amyloid peptides.
Collapse
Affiliation(s)
| | - Guizhao Liang
- Key
laboratory of Biorheological Science and Technology, Ministry of Education
College, Chongqing University, Chongqing 400044, China
| | | | | | | | | | | | - Binrong Ding
- Department
of Chemistry and Biochemistry, California State University, Los Angeles, California, 90032, United States
| | | | - Feimeng Zhou
- Department
of Chemistry and Biochemistry, California State University, Los Angeles, California, 90032, United States
| | | |
Collapse
|
19
|
Srodulski S, Sharma S, Bachstetter AB, Brelsfoard JM, Pascual C, Xie XS, Saatman KE, Van Eldik LJ, Despa F. Neuroinflammation and neurologic deficits in diabetes linked to brain accumulation of amylin. Mol Neurodegener 2014. [PMID: 25149184 DOI: 10.1186/1750-1326-9-30 doi: 10.1186/1750-1326-9-30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND We recently found that brain tissue from patients with type-2 diabetes (T2D) and cognitive impairment contains deposits of amylin, an amyloidogenic hormone synthesized and co-secreted with insulin by pancreatic β-cells. Amylin deposition is promoted by chronic hypersecretion of amylin (hyperamylinemia), which is common in humans with obesity or pre-diabetic insulin resistance. Human amylin oligomerizes quickly when oversecreted, which is toxic, induces inflammation in pancreatic islets and contributes to the development of T2D. Here, we tested the hypothesis that accumulation of oligomerized amylin affects brain function. METHODS In contrast to amylin from humans, rodent amylin is neither amyloidogenic nor cytotoxic. We exploited this fact by comparing rats overexpressing human amylin in the pancreas (HIP rats) with their littermate rats which express only wild-type (WT) non-amyloidogenic rodent amylin. Cage activity, rotarod and novel object recognition tests were performed on animals nine months of age or older. Amylin deposition in the brain was documented by immunohistochemistry, and western blot. We also measured neuroinflammation by immunohistochemistry, quantitative real-time PCR and cytokine protein levels. RESULTS Compared to WT rats, HIP rats show i) reduced exploratory drive, ii) impaired recognition memory and iii) no ability to improve the performance on the rotarod. The development of neurological deficits is associated with amylin accumulation in the brain. The level of oligomerized amylin in supernatant fractions and pellets from brain homogenates is almost double in HIP rats compared with WT littermates (P < 0.05). Large amylin deposits (>50 μm diameter) were also occasionally seen in HIP rat brains. Accumulation of oligomerized amylin alters the brain structure at the molecular level. Immunohistochemistry analysis with an ED1 antibody indicates possible activated microglia/macrophages which are clustering in areas positive for amylin infiltration. Multiple inflammatory markers are expressed in HIP rat brains as opposed to WT rats, confirming that amylin deposition in the brain induces a neuroinflammatory response. CONCLUSIONS Hyperamylinemia promotes accumulation of oligomerized amylin in the brain leading to neurological deficits through an oligomerized amylin-mediated inflammatory response. Additional studies are needed to determine whether brain amylin accumulation may predispose to diabetic brain injury and cognitive decline.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA.
| |
Collapse
|
20
|
Srodulski S, Sharma S, Bachstetter AB, Brelsfoard JM, Pascual C, Xie XS, Saatman KE, Van Eldik LJ, Despa F. Neuroinflammation and neurologic deficits in diabetes linked to brain accumulation of amylin. Mol Neurodegener 2014; 9:30. [PMID: 25149184 PMCID: PMC4144699 DOI: 10.1186/1750-1326-9-30] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/18/2014] [Indexed: 12/23/2022] Open
Abstract
Background We recently found that brain tissue from patients with type-2 diabetes (T2D) and cognitive impairment contains deposits of amylin, an amyloidogenic hormone synthesized and co-secreted with insulin by pancreatic β-cells. Amylin deposition is promoted by chronic hypersecretion of amylin (hyperamylinemia), which is common in humans with obesity or pre-diabetic insulin resistance. Human amylin oligomerizes quickly when oversecreted, which is toxic, induces inflammation in pancreatic islets and contributes to the development of T2D. Here, we tested the hypothesis that accumulation of oligomerized amylin affects brain function. Methods In contrast to amylin from humans, rodent amylin is neither amyloidogenic nor cytotoxic. We exploited this fact by comparing rats overexpressing human amylin in the pancreas (HIP rats) with their littermate rats which express only wild-type (WT) non-amyloidogenic rodent amylin. Cage activity, rotarod and novel object recognition tests were performed on animals nine months of age or older. Amylin deposition in the brain was documented by immunohistochemistry, and western blot. We also measured neuroinflammation by immunohistochemistry, quantitative real-time PCR and cytokine protein levels. Results Compared to WT rats, HIP rats show i) reduced exploratory drive, ii) impaired recognition memory and iii) no ability to improve the performance on the rotarod. The development of neurological deficits is associated with amylin accumulation in the brain. The level of oligomerized amylin in supernatant fractions and pellets from brain homogenates is almost double in HIP rats compared with WT littermates (P < 0.05). Large amylin deposits (>50 μm diameter) were also occasionally seen in HIP rat brains. Accumulation of oligomerized amylin alters the brain structure at the molecular level. Immunohistochemistry analysis with an ED1 antibody indicates possible activated microglia/macrophages which are clustering in areas positive for amylin infiltration. Multiple inflammatory markers are expressed in HIP rat brains as opposed to WT rats, confirming that amylin deposition in the brain induces a neuroinflammatory response. Conclusions Hyperamylinemia promotes accumulation of oligomerized amylin in the brain leading to neurological deficits through an oligomerized amylin-mediated inflammatory response. Additional studies are needed to determine whether brain amylin accumulation may predispose to diabetic brain injury and cognitive decline.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA.
| |
Collapse
|
21
|
Zhang M, Hu R, Liang G, Chang Y, Sun Y, Peng Z, Zheng J. Structural and Energetic Insight into the Cross-Seeding Amyloid Assemblies of Human IAPP and Rat IAPP. J Phys Chem B 2014; 118:7026-36. [DOI: 10.1021/jp5022246] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Mingzhen Zhang
- Department
of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Rundong Hu
- Department
of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Guizhao Liang
- Key
Laboratory of Biorheological Science and Technology, Ministry of Education,
Bioengineering College, Chongqing University, Chongqing 400044, China
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University, Chung Li, Taoyuan 320, Taiwan
| | - Yan Sun
- Department
of Biochemical Engineering and Key Laboratory of Systems Bioengineering
of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Zhenmeng Peng
- Department
of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Jie Zheng
- Department
of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
- Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| |
Collapse
|