1
|
Xu Y, Filice CT, Leonenko Z. Protective effect of trehalose sugar on amyloid-membrane interactions using BLM electrophysiology. Biophys J 2024; 123:1690-1704. [PMID: 38751113 DOI: 10.1016/j.bpj.2024.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/10/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by dementia and memory loss in the elderly population. The amyloid-β peptide (Aβ) is one of the main pathogenic factors in AD and is known to cause damage to neuronal cellular membranes. There is no cure currently available for AD, and new approaches, including preventive strategies, are highly desirable. In this work, we explore the possibility of protecting neuronal membranes from amyloid-induced damage with naturally existing sugar trehalose. Trehalose has been shown to protect plant cellular membranes in extreme conditions and modify Aβ misfolding. We hypothesize that trehalose can protect the neuronal membrane from amyloid toxicity. In this work, we studied the protective effect of trehalose against Aβ1-42-induced damage in model lipid membranes (DPPC/POPC/cholesterol) using atomic force microscopy and black lipid membrane electrophysiology. Our results demonstrate that Aβ1-42 damaged membranes and led to ionic current leakage across these membranes due to the formation of various defects and pores. The presence of trehalose reduced the ion current across membranes caused by Aβ1-42 peptide damage, thus efficiently protecting the membranes. These findings suggest that the trehalose sugar can potentially be useful in protecting neuronal membranes against amyloid toxicity in AD.
Collapse
Affiliation(s)
- Yue Xu
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON, Canada
| | - Carina Teresa Filice
- Department of Biology, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, Waterloo, ON, Canada
| | - Zoya Leonenko
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON, Canada; Department of Biology, University of Waterloo, Waterloo, ON, Canada; Waterloo Institute for Nanotechnology, Waterloo, ON, Canada.
| |
Collapse
|
2
|
Yi Y, Lim MH. Current understanding of metal-dependent amyloid-β aggregation and toxicity. RSC Chem Biol 2023; 4:121-131. [PMID: 36794021 PMCID: PMC9906324 DOI: 10.1039/d2cb00208f] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/22/2022] [Indexed: 11/23/2022] Open
Abstract
The discovery of effective therapeutics targeting amyloid-β (Aβ) aggregates for Alzheimer's disease (AD) has been very challenging, which suggests its complicated etiology associated with multiple pathogenic elements. In AD-affected brains, highly concentrated metals, such as copper and zinc, are found in senile plaques mainly composed of Aβ aggregates. These metal ions are coordinated to Aβ and affect its aggregation and toxicity profiles. In this review, we illustrate the current view on molecular insights into the assembly of Aβ peptides in the absence and presence of metal ions as well as the effect of metal ions on their toxicity.
Collapse
Affiliation(s)
- Yelim Yi
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| | - Mi Hee Lim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| |
Collapse
|
3
|
Chaudhari V, Bagwe-Parab S, Buttar HS, Gupta S, Vora A, Kaur G. Challenges and Opportunities of Metal Chelation Therapy in Trace Metals Overload-Induced Alzheimer's Disease. Neurotox Res 2023; 41:270-287. [PMID: 36705861 DOI: 10.1007/s12640-023-00634-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 11/09/2022] [Accepted: 11/26/2022] [Indexed: 01/28/2023]
Abstract
Essential trace metals like zinc (Zn), iron (Fe), and copper (Cu) play an important physiological role in the metabolomics and healthy functioning of body organs, including the brain. However, abnormal accumulation of trace metals in the brain and dyshomeostasis in the different regions of the brain have emerged as contributing factors in neuronal degeneration, Aβ aggregation, and Tau formation. The link between these essential trace metal ions and the risk of AD has been widely studied, although the conclusions have been ambiguous. Despite the absence of evidence for any clinical benefit, therapeutic chelation is still hypothesized to be a therapeutic option for AD. Furthermore, the parameters like bioavailability, ability to cross the BBB, and chelation specificity must be taken into consideration while selecting a suitable chelation therapy. The data in this review summarizes that the primary intervention in AD is brain metal homeostasis along with brain metal scavenging. This review evaluates the impact of different trace metals (Cu, Zn, Fe) on normal brain functioning and their association with neurodegeneration in AD. Also, it investigates the therapeutic potential of metal chelators in the management of AD. An extensive literature search was carried out on the "Web of Science, PubMed, Science Direct, and Google Scholar" to investigate the effect of trace elements in neurological impairment and the role of metal chelators in AD. In addition, the current review highlights the advantages and limitations of chelation therapies and the difficulties involved in developing selective metal chelation therapy in AD patients.
Collapse
Affiliation(s)
- Vinay Chaudhari
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Siddhi Bagwe-Parab
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Harpal S Buttar
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Ottawa, Ottawa, Canada
| | - Shubhangi Gupta
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Amisha Vora
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Ginpreet Kaur
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India.
| |
Collapse
|
4
|
Rudajev V, Novotny J. Cholesterol as a key player in amyloid β-mediated toxicity in Alzheimer’s disease. Front Mol Neurosci 2022; 15:937056. [PMID: 36090253 PMCID: PMC9453481 DOI: 10.3389/fnmol.2022.937056] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder that is one of the most devastating and widespread diseases worldwide, mainly affecting the aging population. One of the key factors contributing to AD-related neurotoxicity is the production and aggregation of amyloid β (Aβ). Many studies have shown the ability of Aβ to bind to the cell membrane and disrupt its structure, leading to cell death. Because amyloid damage affects different parts of the brain differently, it seems likely that not only Aβ but also the nature of the membrane interface with which the amyloid interacts, helps determine the final neurotoxic effect. Because cholesterol is the dominant component of the plasma membrane, it plays an important role in Aβ-induced toxicity. Elevated cholesterol levels and their regulation by statins have been shown to be important factors influencing the progression of neurodegeneration. However, data from many studies have shown that cholesterol has both neuroprotective and aggravating effects in relation to the development of AD. In this review, we attempt to summarize recent findings on the role of cholesterol in Aβ toxicity mediated by membrane binding in the pathogenesis of AD and to consider it in the broader context of the lipid composition of cell membranes.
Collapse
|
5
|
Xiang J, Xiang C, Zhou L, Sun M, Feng L, Liu C, Cai L, Gong P. Rational Design, Synthesis of Fluorescence Probes for Quantitative Detection of Amyloid-β in Alzheimer's Disease Based on Rhodamine-Metal Complex. Anal Chem 2022; 94:11791-11797. [PMID: 35977343 DOI: 10.1021/acs.analchem.2c01911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The efficient detection and monitoring of amyloid-β plaques (Aβ42) can greatly promote the diagnosis and therapy of Alzheimer's disease (AD). Fluorescence imaging is a promising method for this, but the accurate determination of Aβ42 still remains a challenge. The development of a reliable fluorescent probe to detect Aβ42 is essential. Herein, we report a rational design strategy for Aβ42 fluorescence probes based on rhodamine-copper complexes, Rho1-Cu-Rho4-Cu, among them Rho4-Cu exhibits the best performance including high sensitivity (detection limit = 24 nM), high affinity (Kd = 23.4 nM), and high selectivity; hence, Rho4-Cu is selected for imaging Aβ42 in AD mice, and the results showed that this probe can differentiate normal mice and AD mice effectively.
Collapse
Affiliation(s)
- Jingjing Xiang
- Guangdong Key Laboratory of Nanomedicine, CAS Key Laboratory of Health Informatics, Shenzhen Bioactive Materials Engineering Lab for Medicine, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Chunbai Xiang
- Guangdong Key Laboratory of Nanomedicine, CAS Key Laboratory of Health Informatics, Shenzhen Bioactive Materials Engineering Lab for Medicine, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Lihua Zhou
- School of Applied Biology, Shenzhen Institute of Technology, No. 1 Jiangjunmao, Shenzhen 518116, China
| | - Mengsi Sun
- Biochemistry Core, ShenZhen Bay Laboratory, Shenzhen 518132, China
| | - Lixiong Feng
- School of Applied Biology, Shenzhen Institute of Technology, No. 1 Jiangjunmao, Shenzhen 518116, China
| | - Chuangjun Liu
- College of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian 463000, China
| | - Lintao Cai
- Guangdong Key Laboratory of Nanomedicine, CAS Key Laboratory of Health Informatics, Shenzhen Bioactive Materials Engineering Lab for Medicine, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ping Gong
- Guangdong Key Laboratory of Nanomedicine, CAS Key Laboratory of Health Informatics, Shenzhen Bioactive Materials Engineering Lab for Medicine, Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| |
Collapse
|
6
|
Geng Y, Huang T, Zhou W, Shen L. Physical Mechanism of Amyloid-β Peptide Chain Aggregation on Fluidic Lipid Nanotubules. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5752-5758. [PMID: 35476922 DOI: 10.1021/acs.langmuir.2c00357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The question of how peptide chain aggregation is influenced by lipid membranes with varying shapes and structures is crucial for a detailed understanding of the neurotoxicity effect of the peptide chains. Not like the more usual spherical liposomes and planar lipid membranes, herein, we use lipid nanotubules as a model of important neuron synapse nanowire structures and devote particular attention to the effect of nanotubule fluidity on amyloid-β peptide (Aβ) chain aggregation. We apply single-molecule tracking (SMT) to elucidate how Aβ chains diffuse and aggregate on lipid nanotubules with different fluidities. The physical mechanism implies that fluidic lipid nanotubules facilitate the super-diffusion of two-dimensional (2D)-mobile precursor Aβ chains and promote their aggregation. This aggregation mechanism is retarded on less fluidic lipid nanotubules where the super-diffusion of 2D-mobile precursor Aβ chains is restricted by "frozen" lipids with less mobility. This work provides a mechanistic explanation for Aβ chain aggregation on fluidic lipid nanotubules.
Collapse
|
7
|
Chen Y, Li X, Zhan C, Lao Z, Li F, Dong X, Wei G. A Comprehensive Insight into the Mechanisms of Dopamine in Disrupting Aβ Protofibrils and Inhibiting Aβ Aggregation. ACS Chem Neurosci 2021; 12:4007-4019. [PMID: 34472835 DOI: 10.1021/acschemneuro.1c00306] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fibrillary aggregates of amyloid-β (Aβ) are the pathological hallmark of Alzheimer's disease (AD). Clearing Aβ deposition or inhibiting Aβ aggregation is a promising approach to treat AD. Experimental studies reported that dopamine (DA), an important neurotransmitter, can inhibit Aβ aggregation and disrupt Aβ fibrils in a dose-dependent manner. However, the underlying molecular mechanisms still remain mostly elusive. Herein, we investigated the effect of DA on Aβ42 protofibrils at three different DA-to-Aβ molar ratios (1:1, 2:1, and 10:1) using all-atom molecular dynamics simulations. Our simulations demonstrate that protonated DA at a DA-to-Aβ ratio of 2:1 exhibits stronger Aβ protofibril disruptive capacity than that at a molar-ratio of 1:1 by mostly disrupting the F4-L34-V36 hydrophobic core. When the ratio of DA-to-Aβ increases to 10:1, DA has a high probability to bind to the outer surface of protofibril and has negligible effect on the protofibril structure. Interestingly, at the same DA-to-Aβ ratio (10:1), a mixture of protonated (DA+) and deprotonated (DA0) DA molecules significantly disrupts Aβ protofibrils by the binding of DA0 to the F4-L34-V36 hydrophobic core. Replica-exchange molecular dynamics simulations of Aβ42 dimer show that DA+ inhibits the formation of β-sheets, K28-A42/K28-D23 salt-bridges, and interpeptide hydrophobic interactions and results in disordered coil-rich Aβ dimers, which would inhibit the subsequent fibrillization of Aβ. Further analyses reveal that DA disrupts Aβ protofibril and prevents Aβ dimerization mostly through π-π stacking interactions with residues F4, H6, and H13, hydrogen bonding interactions with negatively charged residues D7, E11, E22 and D23, and cation-π interactions with residues R5. This study provides a complete picture of the molecular mechanisms of DA in disrupting Aβ protofibril and inhibiting Aβ aggregation, which could be helpful for the design of potent drug candidates for the treatment/intervention of AD.
Collapse
Affiliation(s)
- Yujie Chen
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University, Xi’an 710049, People’s Republic of China
| | - Chendi Zhan
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| | - Zenghui Lao
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| | - Fangying Li
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| | - Xuewei Dong
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People’s Republic of China
| |
Collapse
|
8
|
Jia Z, Yuan X, Wei JA, Guo X, Gong Y, Li J, Zhou H, Zhang L, Liu J. A Functionalized Octahedral Palladium Nanozyme as a Radical Scavenger for Ameliorating Alzheimer's Disease. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49602-49613. [PMID: 34641674 DOI: 10.1021/acsami.1c06687] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Oxidative stress is always mentioned as a pathologic appearance of Alzheimer's disease (AD). It is attributed to mitochondrial dysfunction closely linked to Aβ deposition and neurofibrillary tangles (NFTs). Octahedral palladium nanoparticles (Pd NPs) exhibited excellent antioxidant enzyme-like activity and outstanding biocompatibility, but the poor blood-brain barrier (BBB) permeability limits their application in the treatment of Alzheimer's disease. Herein, we constructed a borneol (Bor)-modified octahedral palladium (Pd@PEG@Bor) nanozyme platform to eliminate intracellular reactive oxygen species (ROS) and elevate epithelial cell penetrability. Based on in vitro and in vivo studies, we demonstrate that the Pd@PEG@Bor could efficiently reduce ROS and Ca2+ contents, maintain the mitochondrial membrane potential, and further protect the mitochondria in SH-SY5Y cells. Furthermore, the nanozymes could quickly accumulate in the brain of AD mice and alleviate pathological characteristics such as Aβ plaque deposition, neuron loss, and neuroinflammation. The learning ability and memory function of AD mice are also significantly improved. Overall, this work indicates that the Pd@PEG@Bor nanozymes could delay the progression of AD by regulating ROS levels and also provides a new strategy for the treatment of AD.
Collapse
Affiliation(s)
- Zhi Jia
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| | - Xiaoyu Yuan
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| | - Ji-An Wei
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, P. R. China
| | - Xian Guo
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| | - Youcong Gong
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| | - Jin Li
- Department of Pain Management, the First Affiliated Hospital, Jinan University, Guangzhou 510632, P. R. China
| | - Hui Zhou
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| | - Li Zhang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, P. R. China
| | - Jie Liu
- Department of Chemistry, College of Chemistry and Materials Science, Jinan University, Guangzhou 510632, P. R. China
| |
Collapse
|
9
|
Al-Shammari N, Savva L, Kennedy-Britten O, Platts JA. Forcefield evaluation and accelerated molecular dynamics simulation of Zn(II) binding to N-terminus of amyloid-β. Comput Biol Chem 2021; 93:107540. [PMID: 34271422 DOI: 10.1016/j.compbiolchem.2021.107540] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/11/2021] [Accepted: 06/21/2021] [Indexed: 01/06/2023]
Abstract
We report conventional and accelerated molecular dynamics simulation of Zn(II) bound to the N-terminus of amyloid-β. By comparison against NMR data for the experimentally determined binding mode, we find that certain combinations of forcefield and solvent model perform acceptably in describing the size, shape and secondary structure, and that there is no appreciable difference between implicit and explicit solvent models. We therefore used the combination of ff14SB forcefield and GBSA solvent model to compare the result of different binding modes of Zn(II) to the same peptide, using accelerated MD to enhance sampling and comparing the free peptide simulated in the same way. We show that Zn(II) imparts significant rigidity to the peptide, disrupts the secondary structure and pattern of salt bridges seen in the free peptide, and induces closer contact between residues. Free energy surfaces in 1 or 2 dimensions further highlight the effect of metal coordination on peptide's spatial extent. We also provide evidence that accelerated MD provides improved sampling over conventional MD by visiting as many or more configurations in much shorter simulation times.
Collapse
Affiliation(s)
| | - Loizos Savva
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
| | | | - James A Platts
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
| |
Collapse
|
10
|
Natesh SR, Hummels AR, Sachleben JR, Sosnick TR, Freed KF, Douglas JF, Meredith SC, Haddadian EJ. Molecular dynamics study of water channels in natural and synthetic amyloid-β fibrils. J Chem Phys 2021; 154:235102. [PMID: 34241272 PMCID: PMC8214467 DOI: 10.1063/5.0049250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/12/2021] [Indexed: 11/14/2022] Open
Abstract
We compared all-atom explicit solvent molecular dynamics simulations of three types of Aβ(1-40) fibrils: brain-seeded fibrils (2M4J, with a threefold axial symmetry) and the other two, all-synthetic fibril polymorphs (2LMN and 2LMP, made under different fibrillization conditions). Fibril models were constructed using either a finite or an infinite number of layers made using periodic images. These studies yielded four conclusions. First, finite fibrils tend to unravel in a manner reminiscent of fibril dissolution, while infinite fibrils were more stable during simulations. Second, salt bridges in these fibrils remained stable in those fibrils that contained them initially, and those without salt bridges did not develop them over the time course of the simulations. Third, all fibrils tended to develop a "stagger" or register shift of β-strands along the fibril axis. Fourth and most importantly, the brain-seeded, 2M4J, infinite fibrils allowed bidirectional transport of water in and out of the central longitudinal core of the fibril by rapidly developing gaps at the fibril vertices. 2LMP fibrils also showed this behavior, although to a lesser extent. The diffusion of water molecules in the fibril core region involved two dynamical states: a localized state and directed diffusion in the presence of obstacles. These observations provided support for the hypothesis that Aβ fibrils could act as nanotubes. At least some Aβ oligomers resembled fibrils structurally in having parallel, in-register β-sheets and a sheet-turn-sheet motif. Thus, our findings could have implications for Aβ cytotoxicity, which may occur through the ability of oligomers to form abnormal water and ion channels in cell membranes.
Collapse
Affiliation(s)
- S. R. Natesh
- Biological Sciences Collegiate Division, The University of Chicago, Chicago, Illinois 60637, USA
| | - A. R. Hummels
- Biological Sciences Collegiate Division, The University of Chicago, Chicago, Illinois 60637, USA
| | - J. R. Sachleben
- Division of Biological Sciences, The University of Chicago, Chicago, Illinois 60637, USA
| | - T. R. Sosnick
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
| | - K. F. Freed
- James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
| | - J. F. Douglas
- Material Measurement Laboratory, Material Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - S. C. Meredith
- Departments of Pathology, Biochemistry, and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA
| | - E. J. Haddadian
- Biological Sciences Collegiate Division, The University of Chicago, Chicago, Illinois 60637, USA
| |
Collapse
|
11
|
Roldán-Martín L, Peccati F, Sciortino G, Sodupe M, Maréchal JD. Impact of Cu(II) and Al(III) on the conformational landscape of amyloidβ 1-42. Phys Chem Chem Phys 2021; 23:13023-13032. [PMID: 34095932 DOI: 10.1039/d1cp01561c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Metal ions have been found to play an important role in the formation of extracellular β-amyloid plaques, a major hallmark of Alzheimer's disease. In the present study, the conformational landscape of Aβ42 with Al(iii) and Cu(ii) has been explored using Gaussian accelerated molecular dynamics. Both metals reduce the flexibility of the peptide and entail a higher structural organization, although to different degrees. As a general trend, Cu(ii) binding leads to an increased α-helix content and to the formation of two α-helices that tend to organize in a U-shape. By contrast, most Al(iii) complexes induce a decrease in helical content, leading to more extended structures that favor the appearance of transitory β-strands.
Collapse
Affiliation(s)
- Lorena Roldán-Martín
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain.
| | - Francesca Peccati
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
| | - Giuseppe Sciortino
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain. and Institut of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology (BIST), 43007 Tarragona, Catalonia, Spain
| | - Mariona Sodupe
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain.
| | - Jean-Didier Maréchal
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain.
| |
Collapse
|
12
|
Dong X, Tang Y, Zhan C, Wei G. Green tea extract EGCG plays a dual role in Aβ 42 protofibril disruption and membrane protection: A molecular dynamic study. Chem Phys Lipids 2020; 234:105024. [PMID: 33278382 DOI: 10.1016/j.chemphyslip.2020.105024] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/13/2020] [Accepted: 11/29/2020] [Indexed: 11/18/2022]
Abstract
Amyloid plaques accumulated by the amyloid-β (Aβ) fibrillar aggregates are the major pathological hallmark of the Alzheimer's disease (AD). Inhibiting aggregation and disassembling preformed fibrils of Aβ by natural small molecules have developed into a promising therapeutic strategy for AD. Previous experiments reported that the green tea extract epigallocatechin-3-gallate (EGCG) can disrupt Aβ fibril and reduce Aβ cytotoxicity. The inhibitory ability of EGCG can also be affected by cellular membranes. Thus, it is essential to consider the membrane influences in the investigation of protofibril-disruptive capability of EGCG. Here, we performed multiple all-atom molecular dynamic simulations to investigate the effect of EGCG on the Aβ42 protofibril in the presence of a mixed POPC/POPG (7:3) lipid bilayer and the underlying molecular mechanisms of action. Our simulations show that in the presence of membrane bilayers, EGCG has a preference to bind to the membrane, and this binding alters the binding modes between Aβ42 protofibril and the lipid bilayer, leading to a reduced membrane thinning, indicative of a protective effect of EGCG on the membrane. And EGCG still displays a disruptive effect on Aβ42 protofibril, albeit with a lesser extent of disruption than that in the membrane-free environment. EGCG destabilizes the two hydrophobic core regions (L17-F19-I31 and F4-L34-V36), and disrupts the intrachain K28-A42 salt bridges. Our results reveal that in the presence of lipid bilayers, EGCG plays a dual role in Aβ42 protofibril disruption and membrane protection, suggesting that EGCG could be a potential effective drug candidate for the treatment of AD.
Collapse
Affiliation(s)
- Xuewei Dong
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, 200438, People's Republic of China.
| | - Yiming Tang
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, 200438, People's Republic of China
| | - Chendi Zhan
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, 200438, People's Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, 200438, People's Republic of China.
| |
Collapse
|
13
|
Lei P, Ayton S, Bush AI. The essential elements of Alzheimer's disease. J Biol Chem 2020; 296:100105. [PMID: 33219130 PMCID: PMC7948403 DOI: 10.1074/jbc.rev120.008207] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 02/05/2023] Open
Abstract
Treatments for Alzheimer’s disease (AD) directed against the prominent amyloid plaque neuropathology are yet to be proved effective despite many phase 3 clinical trials. There are several other neurochemical abnormalities that occur in the AD brain that warrant renewed emphasis as potential therapeutic targets for this disease. Among those are the elementomic signatures of iron, copper, zinc, and selenium. Here, we review these essential elements of AD for their broad potential to contribute to Alzheimer’s pathophysiology, and we also highlight more recent attempts to translate these findings into therapeutics. A reinspection of large bodies of discovery in the AD field, such as this, may inspire new thinking about pathogenesis and therapeutic targets.
Collapse
Affiliation(s)
- Peng Lei
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, P.R. China; Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.
| | - Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia
| | - Ashley I Bush
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, Australia.
| |
Collapse
|
14
|
Abdelrahman S, Alghrably M, Lachowicz JI, Emwas AH, Hauser CAE, Jaremko M. "What Doesn't Kill You Makes You Stronger": Future Applications of Amyloid Aggregates in Biomedicine. Molecules 2020; 25:E5245. [PMID: 33187056 PMCID: PMC7696280 DOI: 10.3390/molecules25225245] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/24/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Amyloid proteins are linked to the pathogenesis of several diseases including Alzheimer's disease, but at the same time a range of functional amyloids are physiologically important in humans. Although the disease pathogenies have been associated with protein aggregation, the mechanisms and factors that lead to protein aggregation are not completely understood. Paradoxically, unique characteristics of amyloids provide new opportunities for engineering innovative materials with biomedical applications. In this review, we discuss not only outstanding advances in biomedical applications of amyloid peptides, but also the mechanism of amyloid aggregation, factors affecting the process, and core sequences driving the aggregation. We aim with this review to provide a useful manual for those who engineer amyloids for innovative medicine solutions.
Collapse
Affiliation(s)
- Sherin Abdelrahman
- Laboratory for Nanomedicine, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;
| | - Mawadda Alghrably
- Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
| | - Joanna Izabela Lachowicz
- Department of Medical Sciences and Public Health, University of Cagliari, Policlinico Universitario, I-09042 Monserrato, Italy
| | - Abdul-Hamid Emwas
- Core Labs, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
| | - Charlotte A. E. Hauser
- Laboratory for Nanomedicine, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia;
| | - Mariusz Jaremko
- Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
| |
Collapse
|
15
|
Crooks EJ, Irizarry BA, Ziliox M, Kawakami T, Victor T, Xu F, Hojo H, Chiu K, Simmerling C, Van Nostrand WE, Smith SO, Miller LM. Copper stabilizes antiparallel β-sheet fibrils of the amyloid β40 (Aβ40)-Iowa variant. J Biol Chem 2020; 295:8914-8927. [PMID: 32376688 PMCID: PMC7335782 DOI: 10.1074/jbc.ra119.011955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 04/25/2020] [Indexed: 01/05/2023] Open
Abstract
Cerebral amyloid angiopathy (CAA) is a vascular disorder that primarily involves deposition of the 40-residue-long β-amyloid peptide (Aβ40) in and along small blood vessels of the brain. CAA is often associated with Alzheimer's disease (AD), which is characterized by amyloid plaques in the brain parenchyma enriched in the Aβ42 peptide. Several recent studies have suggested a structural origin that underlies the differences between the vascular amyloid deposits in CAA and the parenchymal plaques in AD. We previously have found that amyloid fibrils in vascular amyloid contain antiparallel β-sheet, whereas previous studies by other researchers have reported parallel β-sheet in fibrils from parenchymal amyloid. Using X-ray fluorescence microscopy, here we found that copper strongly co-localizes with vascular amyloid in human sporadic CAA and familial Iowa-type CAA brains compared with control brain blood vessels lacking amyloid deposits. We show that binding of Cu(II) ions to antiparallel fibrils can block the conversion of these fibrils to the more stable parallel, in-register conformation and enhances their ability to serve as templates for seeded growth. These results provide an explanation for how thermodynamically less stable antiparallel fibrils may form amyloid in or on cerebral vessels by using Cu(II) as a structural cofactor.
Collapse
Affiliation(s)
- Elliot J Crooks
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Brandon A Irizarry
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Martine Ziliox
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Toru Kawakami
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Tiffany Victor
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - Feng Xu
- George & Anne Ryan Institute for Neuroscience and Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Hironobu Hojo
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kelley Chiu
- Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
| | - Carlos Simmerling
- Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
| | - William E Van Nostrand
- George & Anne Ryan Institute for Neuroscience and Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Steven O Smith
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA.
| | - Lisa M Miller
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA; Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
| |
Collapse
|
16
|
Huang M, Liang X, Zhang Z, Wang J, Fei Y, Ma J, Qu S, Mi L. Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E604. [PMID: 32218205 PMCID: PMC7221822 DOI: 10.3390/nano10040604] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 03/24/2020] [Indexed: 12/11/2022]
Abstract
The monitoring of intracellular pH is of great importance for understanding intracellular trafficking and functions. It has various limitations for biosensing based on the fluorescence intensity or spectra study. In this research, pH-sensitive carbon dots (CDs) were employed for intracellular pH sensing with fluorescence lifetime imaging microscopy (FLIM) for the first time. FLIM is a highly sensitive method that is used to detect a microenvironment and it can overcome the limitations of biosensing methods based on fluorescence intensity. The different groups on the CDs surfaces changing with pH environments led to different fluorescence lifetime values. The CDs aqueous solution had a gradual change from 1.6 ns to 3.7 ns in the fluorescence lifetime with a pH range of 2.6-8.6. Similar fluorescence lifetime changes were found in pH buffer-treated living cells. The detection of lysosomes, cytoplasm, and nuclei in living cells was achieved by measuring the fluorescence lifetime of CDs. In particular, a phasor FLIM analysis was used to improve the pH imaging. Moreover, the effects of the coenzymes, amino acids, and proteins on the fluorescence lifetime of CDs were examined in order to mimic the complex microenvironment inside the cells.
Collapse
Affiliation(s)
- Maojia Huang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Xinyue Liang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Zixiao Zhang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jing Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China;
| | - Yiyan Fei
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jiong Ma
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
- Institute of Biomedical Engineering and Technology, Academy for Engineer and Technology, Fudan University, Shanghai 200433, China
- The Multiscale Research Institute of Complex Systems (MRICS), School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Songnan Qu
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China
| | - Lan Mi
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| |
Collapse
|
17
|
Kawahara M, Kato-Negishi M, Tanaka KI. Amyloids: Regulators of Metal Homeostasis in the Synapse. Molecules 2020; 25:molecules25061441. [PMID: 32210005 PMCID: PMC7145306 DOI: 10.3390/molecules25061441] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/17/2020] [Accepted: 03/20/2020] [Indexed: 12/11/2022] Open
Abstract
Conformational changes in amyloidogenic proteins, such as β-amyloid protein, prion proteins, and α-synuclein, play a critical role in the pathogenesis of numerous neurodegenerative diseases, including Alzheimer’s disease, prion disease, and Lewy body disease. The disease-associated proteins possess several common characteristics, including the ability to form amyloid oligomers with β-pleated sheet structure, as well as cytotoxicity, although they differ in amino acid sequence. Interestingly, these amyloidogenic proteins all possess the ability to bind trace metals, can regulate metal homeostasis, and are co-localized at the synapse, where metals are abundantly present. In this review, we discuss the physiological roles of these amyloidogenic proteins in metal homeostasis, and we propose hypothetical models of their pathogenetic role in the neurodegenerative process as the loss of normal metal regulatory functions of amyloidogenic proteins. Notably, these amyloidogenic proteins have the capacity to form Ca2+-permeable pores in membranes, suggestive of a toxic gain of function. Therefore, we focus on their potential role in the disruption of Ca2+ homeostasis in amyloid-associated neurodegenerative diseases.
Collapse
|
18
|
Gao Q, Wu G, Lai KWC. Cholesterol Modulates the Formation of the Aβ Ion Channel in Lipid Bilayers. Biochemistry 2020; 59:992-998. [PMID: 31914730 DOI: 10.1021/acs.biochem.9b00968] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The misfolding of amyloid beta (Aβ) is one of the predominant hallmarks in the pathology of Alzheimer's disease (AD). In this study, we showed that the formation of the Aβ ion channel on the membrane depended on the cholesterol concentration. From a mechanical aspect, we found that cholesterol levels affected the stability and assembly of lipid bilayers. Measurements on planar lipid bilayers indicated that a small amount of cholesterol interacted with Aβ proteins and promoted the insertion process. Conversely, high cholesterol integrated the lipid bilayer and exerted an opposite effect on Aβ insertion. The Aβ ion channel was then detected by graphene-based field-effect transistors. Results demonstrated that the Aβ ion channel promoted a Ca2+ flux in the presence of 15% cholesterol but prevented a Ca2+ flux in high cholesterol. Thus, cholesterol had a complex impact on the Aβ ion channel that can be described as two different effects. First, a small amount of cholesterol interacted with Aβ and facilitated the Aβ ion channel formation in the membrane. Second, a large amount of cholesterol did not induce the ion flux in the membrane, which can be explained by the cholesterol damage to the regular distribution of the lipid bilayer. Overall, this study suggested a possible approach to consider cholesterol levels for the treatment of AD patients.
Collapse
Affiliation(s)
- Qi Gao
- Department of Biomedical Engineering, Centre for Robotics and Automation, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Guangfu Wu
- Department of Biomedical Engineering, Centre for Robotics and Automation, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - King Wai Chiu Lai
- Department of Biomedical Engineering, Centre for Robotics and Automation, City University of Hong Kong, Kowloon Tong, Hong Kong
| |
Collapse
|
19
|
Zhuge X, Li J, Li Y, Yuan C. A turn-off fluorescence probe based on terpyridine for pH monitoring. LUMINESCENCE 2019; 35:373-378. [PMID: 31858706 DOI: 10.1002/bio.3736] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/15/2019] [Accepted: 10/22/2019] [Indexed: 12/12/2022]
Abstract
A new pH-dependent fluorescence probe 2,8-bis((E)-4-([2,2':6',2″-terpyridin]-4'-yl)styryl)-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (TBPTP) based on Tröger's base (TB) bound to terpyridine was designed and synthesized. Photophysical properties and titration experiments of TBPTP were investigated by absorption and fluorescence spectroscopy. TBPTP exhibited high sensitivity in an acidic environment with the working pH range 7.2-2.5, especially having a good liner response to pH changes in the range 2.5-4.3, which suggested that TBPTP is a good candidate for pH monitoring.
Collapse
Affiliation(s)
- Xiangxue Zhuge
- College of Materials Science and Engineering, Tongji University, Caoan Road 4800, Shanghai, China
| | - Jinyan Li
- College of Materials Science and Engineering, Tongji University, Caoan Road 4800, Shanghai, China
| | - Yexin Li
- School of Chemistry and Chemical Engineering, University of Jinan, West Road of Nan Xinzhuang 336, Jinan, China
| | - Chunxue Yuan
- College of Materials Science and Engineering, Tongji University, Caoan Road 4800, Shanghai, China
| |
Collapse
|
20
|
Azouz M, Cullin C, Lecomte S, Lafleur M. Membrane domain modulation of Aβ 1-42 oligomer interactions with supported lipid bilayers: an atomic force microscopy investigation. NANOSCALE 2019; 11:20857-20867. [PMID: 31657431 DOI: 10.1039/c9nr06361g] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Alzheimer's disease is a devastating pathology affecting an increasing number of individuals following the general rise in life expectancy. Amyloid peptide Aβ1-42 has been identified as one of the main culprits of the disease. The peptide has been shown to have major effects on lipid membranes, including membrane fragmentation. The membrane composition has been identified as a factor that plays a pivotal role in regulating peptide/membrane interactions and several results suggest that lipid domains, or rafts, can promote peptide-induced membrane damage. In this work, we examined the effects of lipid segregation on the membrane-perturbing ability of Aβ1-42 and an oligomeric mutant (G37C), a peptide that shares common features with the suspected toxic intermediates involved in the neurodegeneration process. Atomic force microscopy (AFM) was used to determine the impact of these peptides on the supported lipid bilayers of various compositions. In 1,2-dioleoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol (DOPC/DPPC/cholesterol) and DOPC/sphingomyelin/cholesterol ternary mixtures, two systems exhibiting liquid-liquid phase separations, it was shown that Aβ1-42 and G37C exclusively aggregated on liquid-disordered-phase domains, creating large deposits and even causing membrane fragmentation for the latter composition. Cholesterol and ganglioside GM1, the two most documented lipids in the context of Alzheimer's disease, are also considered to play a crucial role in promoting detrimental interactions with amyloid peptides. We show that, in model 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes, the presence of either cholesterol or GM1 in a proportion of 10 mol%, a content supposed to lead to domain formation, favoured the association of both Aβ1-42 and G37C, leading to a harmful membrane fragmentation. The AFM results established that the presence of domains favoured membrane perturbations induced by the amyloid peptides. It is proposed that lipid packing defects at the domain interface could act as adsorption and nucleation sites for the amyloid peptides. The more extensive bilayer perturbations induced by G37C compared to Aβ1-42 supported this hypothesis, indicating that oligomers that cannot mature to the fibril state can present considerable toxicity.
Collapse
Affiliation(s)
- Mehdi Azouz
- Chimie et Biologie des Membranes et Nanoobjets, CBMN CNRS UMR 5248, Université de Bordeaux, Allée Geoffroy de Saint-Hilaire, 33600 Pessac, France and Department of Chemistry, Université de Montréal, Montréal, Québec, Canada.
| | - Christophe Cullin
- Chimie et Biologie des Membranes et Nanoobjets, CBMN CNRS UMR 5248, Université de Bordeaux, Allée Geoffroy de Saint-Hilaire, 33600 Pessac, France
| | - Sophie Lecomte
- Chimie et Biologie des Membranes et Nanoobjets, CBMN CNRS UMR 5248, Université de Bordeaux, Allée Geoffroy de Saint-Hilaire, 33600 Pessac, France
| | - Michel Lafleur
- Department of Chemistry, Université de Montréal, Montréal, Québec, Canada.
| |
Collapse
|
21
|
Active-site environment of Cu bound amyloid β and amylin peptides. J Biol Inorg Chem 2019; 24:1245-1259. [DOI: 10.1007/s00775-019-01724-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/05/2019] [Indexed: 01/09/2023]
|
22
|
Stevenson MJ, Farran IC, Uyeda KS, San Juan JA, Heffern MC. Analysis of Metal Effects on C-Peptide Structure and Internalization. Chembiochem 2019; 20:2447-2453. [PMID: 31074079 DOI: 10.1002/cbic.201900172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Indexed: 01/17/2023]
Abstract
The connecting peptide (C-peptide) has received increased attention for its potential therapeutic effects in ameliorating illnesses such as kidney disease and diabetes. Although the mechanism of C-peptide signaling remains elusive, evidence supports its internalization and intracellular function. Emerging research is uncovering the diverse biological roles metals play in controlling and affecting the function of bioactive peptides. The work presented herein investigates interactions between C-peptide and first-row d-block transition metals, as well as their effects on C-peptide internalization into cells. Through spectroscopic techniques, it is demonstrated that CrIII , CuII , and ZnII bind to C-peptide with differing stoichiometries and biologically relevant affinities. In addition, metal binding elicits both subtle changes in secondary structure and inhibits adoption of an α-helical character in environments where the dielectric constants are reduced. This study shows how metal ions can modulate peptide hormone activity through subtle structural changes to disrupt cellular uptake.
Collapse
Affiliation(s)
- Michael J Stevenson
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Ian C Farran
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Kylie S Uyeda
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Jessica A San Juan
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| | - Marie C Heffern
- Department of Chemistry, University of California, One Shields Avenue, Davis, CA, 95616, USA
| |
Collapse
|
23
|
Ma X, Chen S, Yu H, Guan Y, Li J, Yan X, Zhang Z. A Phenanthroline-Based Fluorescent Probe for Highly Selective Detection of Extreme Alkalinity (pH > 14) in Aqueous Solution. NANOSCALE RESEARCH LETTERS 2019; 14:318. [PMID: 31535227 PMCID: PMC6751243 DOI: 10.1186/s11671-019-3149-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Although numerous fluorescent probes are designed to detect the pH value in the past decades, developing fluorescent probes for extreme alkalinity (pH > 14) detection in aqueous solution is still a great challenge. In this work, we utilized 1H-imidazo[4,5-f][1, 10] phenanthroline (IP) group as the recognition group of hydroxyl ion and introduced two triethylene glycol monomethyl ether groups to improve its solubility. This IP derivative, BMIP, possessed good solubility (25 mg/mL) in water. It displayed high selectivity toward extreme alkalinity (pH > 14) over other ions and pH (from extreme acidity to pH = 14). From 3 to 6 mol/L OH-, the exact concentration of OH- could be revealed by BMIP and the whole detection process just needed a short time (≤ 10 s). Meanwhile, it exhibited good anti-interference ability and repeatability during the detection process. Through optical spectra and NMR analysis, its detection mechanism was proved to be deprotonation by hydroxyl ion and then aggregation-induced enhanced emission. Our study presents a new basic group based on which researchers can develop new fluorescent probes that can detect extreme alkalinity (pH > 14) in aqueous solution.
Collapse
Affiliation(s)
- Xiaoyu Ma
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China
- College of Chemistry, Jilin University, Changchun, 130012, People's Republic of China
| | - Shanyong Chen
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China.
| | - Hong Yu
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China.
| | - Youwei Guan
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China
| | - Junjun Li
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China
| | - Xingwu Yan
- Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Yongchuan, 402160, People's Republic of China
| | - Zhenghao Zhang
- State Grid Tianjin Electric Power Corporation Chengxi District Supply Company, Tianjin, 300191, People's Republic of China
| |
Collapse
|
24
|
Österlund N, Luo J, Wärmländer SK, Gräslund A. Membrane-mimetic systems for biophysical studies of the amyloid-β peptide. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:492-501. [DOI: 10.1016/j.bbapap.2018.11.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 10/18/2018] [Accepted: 11/17/2018] [Indexed: 10/27/2022]
|
25
|
Affiliation(s)
- Bowen Yang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China
| | - Jianlin Shi
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China
| |
Collapse
|
26
|
Sahoo A, Matysiak S. Computational insights into lipid assisted peptide misfolding and aggregation in neurodegeneration. Phys Chem Chem Phys 2019; 21:22679-22694. [DOI: 10.1039/c9cp02765c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An overview of recent advances in computational investigation of peptide–lipid interactions in neurodegeneration – Alzheimer's, Parkinson's and Huntington's disease.
Collapse
Affiliation(s)
- Abhilash Sahoo
- Biophysics Program
- Institute of Physical Science and Technology
- University of Maryland
- College Park
- USA
| | - Silvina Matysiak
- Biophysics Program
- Institute of Physical Science and Technology
- University of Maryland
- College Park
- USA
| |
Collapse
|
27
|
Rana M, Sharma AK. Cu and Zn interactions with Aβ peptides: consequence of coordination on aggregation and formation of neurotoxic soluble Aβ oligomers. Metallomics 2019; 11:64-84. [DOI: 10.1039/c8mt00203g] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The coordination chemistry of transition metal ions (Fe, Cu, Zn) with the amyloid-β (Aβ) peptides has attracted a lot of attention in recent years due to its repercussions in Alzheimer's disease (AD).
Collapse
Affiliation(s)
- Monika Rana
- Department of Chemistry
- Central University of Rajasthan
- Ajmer 305817
- India
| | - Anuj Kumar Sharma
- Department of Chemistry
- Central University of Rajasthan
- Ajmer 305817
- India
| |
Collapse
|
28
|
Li S, Lin D, Hu X, Yang X. Directly probing the dissociation effects of graphene oxide nanosheets on hIAPP fibrils. NANOTECHNOLOGY 2018; 29:495102. [PMID: 30211692 DOI: 10.1088/1361-6528/aae143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The aggregation of human islet amyloid polypeptides (hIAPP) to mature fibrils is considered as the main cause of type II diabetes. Therefore destroying the pre-formed hIAPP fibrils is expected to be a promising strategy for therapeutic treatments. In this work, the dissociation effects of graphene oxide (GO) nanosheets on hIAPP mature fibrils are investigated. The results clearly demonstrate that hIAPP fibrils can be quickly adsorbed on the GO surface and efficiently broken into short fragments. Meanwhile, the β-sheet structures of hIAPP fibrils are greatly destroyed. Particularly, in situ atomic force microscopy was applied to monitor the real-time interaction between hIAPP fibrils and GO nanosheets. It provides distinct evidence that the disruption of hIAPP fibrils by GO nanosheets mainly occurs at the GO edges. Size-dependent experiments further justify the interfere of edge contribution, which suggest small-sized GO nanosheets exhibit better dissociation ability than large-sized ones. Therefore, this study not only provides valuable information that GO nanosheets (especially small-sized ones) can act as efficient nanoblades to break hIAPP fibrils, but also suggests a powerful and widely available methodology for investigating real-time interaction between nanomaterials and biomolecules.
Collapse
Affiliation(s)
- Shujie Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China. Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, People's Republic of China
| | | | | | | |
Collapse
|
29
|
Houghtaling J, List J, Mayer M. Nanopore-Based, Rapid Characterization of Individual Amyloid Particles in Solution: Concepts, Challenges, and Prospects. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1802412. [PMID: 30225962 DOI: 10.1002/smll.201802412] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/15/2018] [Indexed: 06/08/2023]
Abstract
Aggregates of misfolded proteins are associated with several devastating neurodegenerative diseases. These so-called amyloids are therefore explored as biomarkers for the diagnosis of dementia and other disorders, as well as for monitoring disease progression and assessment of the efficacy of therapeutic interventions. Quantification and characterization of amyloids as biomarkers is particularly demanding because the same amyloid-forming protein can exist in different states of assembly, ranging from nanometer-sized monomers to micrometer-long fibrils that interchange dynamically both in vivo and in samples from body fluids ex vivo. Soluble oligomeric amyloid aggregates, in particular, are associated with neurotoxic effects, and their molecular organization, size, and shape appear to determine their toxicity. This concept article proposes that the emerging field of nanopore-based analytics on a single molecule and single aggregate level holds the potential to account for the heterogeneity of amyloid samples and to characterize these particles-rapidly, label-free, and in aqueous solution-with regard to their size, shape, and abundance. The article describes the concept of nanopore-based resistive pulse sensing, reviews previous work in amyloid analysis, and discusses limitations and challenges that will need to be overcome to realize the full potential of amyloid characterization on a single-particle level.
Collapse
Affiliation(s)
- Jared Houghtaling
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700, Fribourg, Switzerland
| | - Jonathan List
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700, Fribourg, Switzerland
| | - Michael Mayer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700, Fribourg, Switzerland
| |
Collapse
|
30
|
Coskuner-Weber O. Revisiting Cu(II) Bound Amyloid-β40 and Amyloid-β42 Peptides: Varying Coordination Chemistries. JOURNAL OF THE TURKISH CHEMICAL SOCIETY, SECTION A: CHEMISTRY 2018. [DOI: 10.18596/jotcsa.424144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
31
|
Conformational heterogeneity of tau: Implication on intrinsic disorder, acid stability and fibrillation in Alzheimer's disease. Biophys Chem 2018; 241:27-37. [PMID: 30081240 DOI: 10.1016/j.bpc.2018.07.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/17/2018] [Accepted: 07/24/2018] [Indexed: 11/20/2022]
Abstract
The self-assembly of intrinsically disordered protein tau into paired helical filament forms one of the hallmarks of Alzheimer's disease. However, the facets of innately disordered structure of tau and its conversion to a β-sheet-rich fibril during several tauopathies are poorly understood. Here, we provide a direct insight into the ensemble of highly heterogeneous conformational families of tau at physiological pH, by nano-electrospray mass spectrometry coupled with ion mobility. The average collision cross section of the most unfolded conformer was higher by >2 fold than that of the most folded one. Acidic pH largely induced unfolding in tau, obliterating the compact conformers completely. The highly unfolded conformers were the key species bestowing the unusual solubility to tau at low pH, with limited contribution from intramolecular long-range interfaces giving rise to ordered conformers. Contrarily, alkaline pH shifted tau towards folded conformations due to charge neutralization, keeping the overall random coil architecture intact. Intriguingly, the heparin-induced in vitro aggregation propensity of the protein attenuated at both acidic and alkaline pH, illustrating the significance of altered conformations in pathological functions of tau. Our observations at low pH indicate that a reorganization of the intricate network of momentary long-range contacts in tau might have implication in its aggregation pathology. Disease-modifying therapies for Alzheimer's disease targeting either to disrupt the essential fibril-forming interaction at third microtubule-binding repeat of tau or to perturb specific binding interaction of tau with endogenous polyanionic species might be of high benefit.
Collapse
|
32
|
Xi W, Hansmann UHE. Conversion between parallel and antiparallel β-sheets in wild-type and Iowa mutant Aβ 40 fibrils. J Chem Phys 2018; 148:045103. [PMID: 29390821 DOI: 10.1063/1.5016166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Using a variant of Hamilton-replica-exchange, we study for wild type and Iowa mutant Aβ40 the conversion between fibrils with antiparallel β-sheets and such with parallel β-sheets. We show that wild type and mutant form distinct salt bridges that in turn stabilize different fibril organizations. The conversion between the two fibril forms leads to the release of small aggregates that in the Iowa mutant may shift the equilibrium from fibrils to more toxic oligomers.
Collapse
Affiliation(s)
- Wenhui Xi
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Ulrich H E Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, USA
| |
Collapse
|
33
|
Galante D, Cavallo E, Perico A, D'Arrigo C. Effect of ferric citrate on amyloid-beta peptides behavior. Biopolymers 2018; 109:e23224. [PMID: 29897618 DOI: 10.1002/bip.23224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/06/2018] [Accepted: 04/19/2018] [Indexed: 12/26/2022]
Abstract
Amyloid beta (Aβ) aggregation and oxidative stress are two of the central events in Alzheimer's Disease (AD). Both these phenomena can be caused by the interaction of Aβ with metal ions. In the last years the interaction between ZnII , CuII , and Aβ was much studied, but between iron and Aβ it is still little known. In this work we determine how three Aβ peptides, present in AD, interact with FeIII -citrate. The three Aβ peptides are: full length Aβ1-42, an isoform truncated at Glutamic acid in position three, Aβ3-42, and its pyroglutamated form AβpE3-42. Conformation and morphology of the three peptides, aggregated with and without FeIII -citrate were studied. Besides, we have determined the strength of the interactions Aβ/FeIII -citrate studying the effect of ethylenediaminetetraacetic acid as chelator. Results reported here demonstrate that FeIII -citrate promotes the aggregation in all the three peptides. Moreover, Aspartic acid 1, Glutamic acid 3, and Tyrosine 10 have an important role in the coordination with iron, generating a more stable complex for Aβ1-42 compared to that for the truncated peptides.
Collapse
Affiliation(s)
- D Galante
- Institute for Macromolecular Studies, National Research Council, Genova, 16149, Italy
| | - E Cavallo
- Institute for Macromolecular Studies, National Research Council, Genova, 16149, Italy.,Department of Chemistry and Industrial Chemistry, University of Genova, Via Dodecaneso 31, Genova, 16146, Italy
| | - A Perico
- Institute for Macromolecular Studies, National Research Council, Genova, 16149, Italy
| | - C D'Arrigo
- Institute for Macromolecular Studies, National Research Council, Genova, 16149, Italy
| |
Collapse
|
34
|
Niu Z, Zhang Z, Zhao W, Yang J. Interactions between amyloid β peptide and lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1663-1669. [PMID: 29679539 DOI: 10.1016/j.bbamem.2018.04.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 10/17/2022]
Abstract
The presence of amyloid plaques in the brain is a typical characteristic of Alzheimer's disease (AD). Amyloid plaques are formed from the deposits of aggregated amyloid β peptide (Aβ). The toxicity induced by Aβ aggregates is correlated with Aβ-membrane interactions. The mutual influences between aggregation and membranes are complicated and unclear. In recent years advanced experiments and findings are emerging to give us more detailed information on Aβ-membrane interactions. In this review, we mainly focus on the Aβ-membrane interactions and membrane-induced Aβ structures. The mechanism of Aβ-membrane interactions is also summarized, which provides insights into the prevention and treatment of AD.
Collapse
Affiliation(s)
- Zheng Niu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 430071 Wuhan, PR China
| | - Zhengfeng Zhang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 430071 Wuhan, PR China
| | - Weijing Zhao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 430071 Wuhan, PR China
| | - Jun Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 430071 Wuhan, PR China.
| |
Collapse
|
35
|
Analysis of Physicochemical Interaction of Aβ40 with a GM1 Ganglioside-Containing Lipid Membrane. J Phys Chem B 2018. [DOI: 10.1021/acs.jpcb.8b00139] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
36
|
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: 95] [Impact Index Per Article: 15.8] [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
|
37
|
Chen GF, Xu TH, Yan Y, Zhou YR, Jiang Y, Melcher K, Xu HE. Amyloid beta: structure, biology and structure-based therapeutic development. Acta Pharmacol Sin 2017; 38:1205-1235. [PMID: 28713158 PMCID: PMC5589967 DOI: 10.1038/aps.2017.28] [Citation(s) in RCA: 938] [Impact Index Per Article: 134.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/02/2017] [Indexed: 12/12/2022] Open
Abstract
Amyloid beta peptide (Aβ) is produced through the proteolytic processing of a transmembrane protein, amyloid precursor protein (APP), by β- and γ-secretases. Aβ accumulation in the brain is proposed to be an early toxic event in the pathogenesis of Alzheimer's disease, which is the most common form of dementia associated with plaques and tangles in the brain. Currently, it is unclear what the physiological and pathological forms of Aβ are and by what mechanism Aβ causes dementia. Moreover, there are no efficient drugs to stop or reverse the progression of Alzheimer's disease. In this paper, we review the structures, biological functions, and neurotoxicity role of Aβ. We also discuss the potential receptors that interact with Aβ and mediate Aβ intake, clearance, and metabolism. Additionally, we summarize the therapeutic developments and recent advances of different strategies for treating Alzheimer's disease. Finally, we will report on the progress in searching for novel, potentially effective agents as well as selected promising strategies for the treatment of Alzheimer's disease. These prospects include agents acting on Aβ, its receptors and tau protein, such as small molecules, vaccines and antibodies against Aβ; inhibitors or modulators of β- and γ-secretase; Aβ-degrading proteases; tau protein inhibitors and vaccines; amyloid dyes and microRNAs.
Collapse
Affiliation(s)
- Guo-Fang Chen
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ting-Hai Xu
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yan Yan
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yu-Ren Zhou
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yi Jiang
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Karsten Melcher
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - H Eric Xu
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| |
Collapse
|
38
|
Dharmadana D, Reynolds NP, Conn CE, Valéry C. Molecular interactions of amyloid nanofibrils with biological aggregation modifiers: implications for cytotoxicity mechanisms and biomaterial design. Interface Focus 2017; 7:20160160. [PMID: 28630679 PMCID: PMC5474041 DOI: 10.1098/rsfs.2016.0160] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Amyloid nanofibrils are ubiquitous biological protein fibrous aggregates, with a wide range of either toxic or beneficial activities that are relevant to human disease and normal biology. Protein amyloid fibrillization occurs via nucleated polymerization, through non-covalent interactions. As such, protein nanofibril formation is based on a complex interplay between kinetic and thermodynamic factors. The process entails metastable oligomeric species and a highly thermodynamically favoured end state. The kinetics, and the reaction pathway itself, can be influenced by third party moieties, either molecules or surfaces. Specifically, in the biological context, different classes of biomolecules are known to act as catalysts, inhibitors or modifiers of the generic protein fibrillization process. The biological aggregation modifiers reviewed here include lipid membranes of varying composition, glycosaminoglycans and metal ions, with a final word on xenobiotic compounds. The corresponding molecular interactions are critically analysed and placed in the context of the mechanisms of cytotoxicity of the amyloids involved in diverse pathologies and the non-toxicity of functional amyloids (at least towards their biological host). Finally, the utilization of this knowledge towards the design of bio-inspired and biocompatible nanomaterials is explored.
Collapse
Affiliation(s)
- Durga Dharmadana
- School of Health and Biomedical Sciences, Discipline of Pharmaceutical Sciences, RMIT University, Bundoora, Melbourne, Victoria 3083, Australia
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3001, Australia
| | - Nicholas P. Reynolds
- ARC Training Centre for Biodevices, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria 3122, Australia
| | - Charlotte E. Conn
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3001, Australia
| | - Céline Valéry
- School of Health and Biomedical Sciences, Discipline of Pharmaceutical Sciences, RMIT University, Bundoora, Melbourne, Victoria 3083, Australia
| |
Collapse
|
39
|
Kedia N, Almisry M, Bieschke J. Glucose directs amyloid-beta into membrane-active oligomers. Phys Chem Chem Phys 2017; 19:18036-18046. [PMID: 28671211 PMCID: PMC5654640 DOI: 10.1039/c7cp02849k] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oligomeric amyloid-β 1-42 (Aβ-42) peptides are considered to be the most toxic species connected to the occurrence of Alzheimer's disease. However, not all aggregation conditions promote oligomer formation in vitro, raising the question whether oligomer formation in vivo also requires a specific suitable cellular environment. We recently found that interaction with neuronal membranes initiates aggregation of Aβ-42 and neuronal uptake. Our data suggest that small molecules in the extracellular space can facilitate the formation of membrane-active Aβ-42 oligomers. We analyzed the early stage of Aβ-42 aggregation in the presence of glucose and sucrose and found that these sugars strongly favor Aβ-42 oligomer formation. We characterized oligomers by dynamic light scattering, atomic force microscopy, immuno-transmission electron microscopy and fluorescence cross correlation spectroscopy. We found that Aβ-42 spontaneously and rapidly forms low molecular weight oligomers in the presence of sugars. Slightly acidic pH (6.7-7) greatly favors oligomer formation when compared to the extracellular physiological pH (7.4). Circular dichroism demonstrated that these Aβ-42 oligomers did not adopt a β-sheet structure. Unstructured oligomeric Aβ-42 interacted with membrane bilayers of giant unilamellar vesicles (GUV) and neuronal model cells, facilitated cellular uptake of Aβ-42, and inhibition of mitochondrial activity. Our data therefore suggest that elevated concentrations of glucose within the range observed in diabetic individuals (10 mM) facilitate the formation of membrane-active Aβ-42 oligomers.
Collapse
Affiliation(s)
- Niraja Kedia
- Department of Biomedical Engineering, Washington University, 63130 St. Louis, MO, USA.
| | - Michael Almisry
- Department of Biomedical Engineering, Washington University, 63130 St. Louis, MO, USA.
| | - Jan Bieschke
- Department of Biomedical Engineering, Washington University, 63130 St. Louis, MO, USA.
| |
Collapse
|
40
|
Copper(II) interaction with the Human Prion 103–112 fragment – Coordination and oxidation. J Inorg Biochem 2017; 170:195-201. [DOI: 10.1016/j.jinorgbio.2017.02.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/10/2017] [Accepted: 02/17/2017] [Indexed: 11/20/2022]
|
41
|
Challenges in studying the structures of metal-amyloid oligomers related to type 2 diabetes, Parkinson's disease, and Alzheimer's disease. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.04.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
42
|
Tiiman A, Luo J, Wallin C, Olsson L, Lindgren J, Jarvet J, Per R, Sholts SB, Rahimipour S, Abrahams JP, Karlström AE, Gräslund A, Wärmländer SK. Specific Binding of Cu(II) Ions to Amyloid-Beta Peptides Bound to Aggregation-Inhibiting Molecules or SDS Micelles Creates Complexes that Generate Radical Oxygen Species. J Alzheimers Dis 2016; 54:971-982. [DOI: 10.3233/jad-160427] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ann Tiiman
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
| | - Jinghui Luo
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
- Chemical Research Laboratory, University of Oxford, UK
| | - Cecilia Wallin
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
| | - Lisa Olsson
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
| | | | - Jϋri Jarvet
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
- The National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Roos Per
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Clinical Physiology, Capio St.Göran Hospital, Stockholm, Sweden
| | - Sabrina B. Sholts
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
- Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Shai Rahimipour
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | - Jan Pieter Abrahams
- Biozentrum, University of Basel, Switzerland & Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland
| | | | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Sweden
| | | |
Collapse
|
43
|
Jin S, Kedia N, Illes-Toth E, Haralampiev I, Prisner S, Herrmann A, Wanker EE, Bieschke J. Amyloid-β(1-42) Aggregation Initiates Its Cellular Uptake and Cytotoxicity. J Biol Chem 2016; 291:19590-606. [PMID: 27458018 PMCID: PMC5016693 DOI: 10.1074/jbc.m115.691840] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 07/18/2016] [Indexed: 12/12/2022] Open
Abstract
The accumulation of amyloid β peptide(1-42) (Aβ(1-42)) in extracellular plaques is one of the pathological hallmarks of Alzheimer disease (AD). Several studies have suggested that cellular reuptake of Aβ(1-42) may be a crucial step in its cytotoxicity, but the uptake mechanism is not yet understood. Aβ may be present in an aggregated form prior to cellular uptake. Alternatively, monomeric peptide may enter the endocytic pathway and conditions in the endocytic compartments may induce the aggregation process. Our study aims to answer the question whether aggregate formation is a prerequisite or a consequence of Aβ endocytosis. We visualized aggregate formation of fluorescently labeled Aβ(1-42) and tracked its internalization by human neuroblastoma cells and neurons. β-Sheet-rich Aβ(1-42) aggregates entered the cells at low nanomolar concentration of Aβ(1-42). In contrast, monomer uptake faced a concentration threshold and occurred only at concentrations and time scales that allowed Aβ(1-42) aggregates to form. By uncoupling membrane binding from internalization, we found that Aβ(1-42) monomers bound rapidly to the plasma membrane and formed aggregates there. These structures were subsequently taken up and accumulated in endocytic vesicles. This process correlated with metabolic inhibition. Our data therefore imply that the formation of β-sheet-rich aggregates is a prerequisite for Aβ(1-42) uptake and cytotoxicity.
Collapse
Affiliation(s)
- Sha Jin
- From the Proteomics and Molecular Mechanisms of Neurodegenerative Diseases, Max Delbrück Center for Molecular Medicine, 13125 Berlin-Buch, Germany, the Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130
| | - Niraja Kedia
- the Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130
| | - Eva Illes-Toth
- the Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130
| | | | | | - Andreas Herrmann
- IRI Life Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Erich E Wanker
- From the Proteomics and Molecular Mechanisms of Neurodegenerative Diseases, Max Delbrück Center for Molecular Medicine, 13125 Berlin-Buch, Germany
| | - Jan Bieschke
- the Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63130,
| |
Collapse
|
44
|
Membrane binding of peptide models for early stages of amyloid formation: Lipid packing counts more than charge. Chem Phys Lipids 2016; 198:28-38. [DOI: 10.1016/j.chemphyslip.2016.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 02/04/2016] [Accepted: 02/27/2016] [Indexed: 11/17/2022]
|
45
|
Ahmad A, Burns CS, Fink AL, Uversky VN. Peculiarities of copper binding to alpha-synuclein. J Biomol Struct Dyn 2016; 29:825-42. [PMID: 22208282 DOI: 10.1080/073911012010525023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Heavy metals have been implicated as the causative agents for the pathogenesis of the most prevalent neurodegenerative disease. Various mechanisms have been proposed to explain the toxic effects of metals ranging from metal-induced oxidation of protein to metal-induced changes in the protein conformation. Aggregation of a-synuclein is implicated in Parkinson's disease (PD), and various metals, including copper, constitute a prominent group of alpha-synuclein aggregation enhancers. In this study, we have systematically characterized the a-synuclein-Cu21 binding sites and analyzed the possible role of metal binding in a-synuclein fibrillation using a set of biophysical techniques, such as electron paramagnetic resonance (EPR), electron spin-echo envelope modulation (ESEEM), circular dichroism (CD), and size exclusion chromatography (SEC). Our analyses indicated that a-synuclein possesses at least two binding sites for Cu21. We have been able to locate one of the binding sites in the N-terminal region. Furthermore, based on the EPR studies of model peptides and Beta-synuclein, we concluded that the suspected His residue did not appear to participate in strong Cu21 binding.
Collapse
Affiliation(s)
- Atta Ahmad
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California, USA.
| | | | | | | |
Collapse
|
46
|
Han SH, Park JC, Mook-Jung I. Amyloid β-interacting partners in Alzheimer's disease: From accomplices to possible therapeutic targets. Prog Neurobiol 2016; 137:17-38. [DOI: 10.1016/j.pneurobio.2015.12.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 12/02/2015] [Accepted: 12/09/2015] [Indexed: 12/20/2022]
|
47
|
Wang P, Huang J, Gu Y. Rational design of a novel mitochondrial-targeted near-infrared fluorescent pH probe for imaging in living cells and in vivo. RSC Adv 2016. [DOI: 10.1039/c6ra22470a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A novel mitochondrial-targeted fluorescent pH probe NIR-F1 could sensitively and selectively monitor pH changes in living cells and living mice.
Collapse
Affiliation(s)
- Peng Wang
- Department of Biomedical Engineering
- School of Engineering
- China Pharmaceutical University
- Nanjing
- PR China
| | - Jinxin Huang
- Department of Biomedical Engineering
- School of Engineering
- China Pharmaceutical University
- Nanjing
- PR China
| | - Yueqing Gu
- Department of Biomedical Engineering
- School of Engineering
- China Pharmaceutical University
- Nanjing
- PR China
| |
Collapse
|
48
|
Bhowmik D, Mote KR, MacLaughlin CM, Biswas N, Chandra B, Basu JK, Walker GC, Madhu PK, Maiti S. Cell-Membrane-Mimicking Lipid-Coated Nanoparticles Confer Raman Enhancement to Membrane Proteins and Reveal Membrane-Attached Amyloid-β Conformation. ACS NANO 2015; 9:9070-7. [PMID: 26391443 DOI: 10.1021/acsnano.5b03175] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Identifying the structures of membrane bound proteins is critical to understanding their function in healthy and diseased states. We introduce a surface enhanced Raman spectroscopy technique which can determine the conformation of membrane-bound proteins, at low micromolar concentrations, and also in the presence of a substantial membrane-free fraction. Unlike conventional surface enhanced Raman spectroscopy, our approach does not require immobilization of molecules, as it uses spontaneous binding of proteins to lipid bilayer-encapsulated Ag nanoparticles. We apply this technique to probe membrane-attached oligomers of Amyloid-β40 (Aβ40), whose conformation is keenly sought in the context of Alzheimer's disease. Isotope-shifts in the Raman spectra help us obtain secondary structure information at the level of individual residues. Our results show the presence of a β-turn, flanked by two β-sheet regions. We use solid-state NMR data to confirm the presence of the β-sheets in these regions. In the membrane-attached oligomer, we find a strongly contrasting and near-orthogonal orientation of the backbone H-bonds compared to what is found in the mature, less-toxic Aβ fibrils. Significantly, this allows a "porin" like β-barrel structure, providing a structural basis for proposed mechanisms of Aβ oligomer toxicity.
Collapse
Affiliation(s)
- Debanjan Bhowmik
- Department of Chemical Sciences, Tata Institute of Fundamental Research , Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences , 21 Brundavan Colony, Narsinghi, Hyderabad 500075, India
| | - Christina M MacLaughlin
- Department of Chemistry, Lash Miller Laboratories, University of Toronto , Toronto, ON M5S 3H6, Canada
| | - Nupur Biswas
- Department of Physics, Indian Institute of Science , Bengaluru 560012, India
| | - Bappaditya Chandra
- Department of Chemical Sciences, Tata Institute of Fundamental Research , Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Jaydeep K Basu
- Department of Physics, Indian Institute of Science , Bengaluru 560012, India
| | - Gilbert C Walker
- Department of Chemistry, Lash Miller Laboratories, University of Toronto , Toronto, ON M5S 3H6, Canada
| | - Perunthiruthy K Madhu
- Department of Chemical Sciences, Tata Institute of Fundamental Research , Homi Bhabha Road, Colaba, Mumbai 400005, India
- TIFR Centre for Interdisciplinary Sciences , 21 Brundavan Colony, Narsinghi, Hyderabad 500075, India
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research , Homi Bhabha Road, Colaba, Mumbai 400005, India
| |
Collapse
|
49
|
Gamba P, Testa G, Gargiulo S, Staurenghi E, Poli G, Leonarduzzi G. Oxidized cholesterol as the driving force behind the development of Alzheimer's disease. Front Aging Neurosci 2015; 7:119. [PMID: 26150787 PMCID: PMC4473000 DOI: 10.3389/fnagi.2015.00119] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD), the most common neurodegenerative disorder associated with dementia, is typified by the pathological accumulation of amyloid Aβ peptides and neurofibrillary tangles (NFT) within the brain. Considerable evidence indicates that many events contribute to AD progression, including oxidative stress, inflammation, and altered cholesterol metabolism. The brain’s high lipid content makes it particularly vulnerable to oxidative species, with the consequent enhancement of lipid peroxidation and cholesterol oxidation, and the subsequent formation of end products, mainly 4-hydroxynonenal and oxysterols, respectively from the two processes. The chronic inflammatory events observed in the AD brain include activation of microglia and astrocytes, together with enhancement of inflammatory molecule and free radical release. Along with glial cells, neurons themselves have been found to contribute to neuroinflammation in the AD brain, by serving as sources of inflammatory mediators. Oxidative stress is intimately associated with neuroinflammation, and a vicious circle has been found to connect oxidative stress and inflammation in AD. Alongside oxidative stress and inflammation, altered cholesterol metabolism and hypercholesterolemia also significantly contribute to neuronal damage and to progression of AD. Increasing evidence is now consolidating the hypothesis that oxidized cholesterol is the driving force behind the development of AD, and that oxysterols are the link connecting the disease to altered cholesterol metabolism in the brain and hypercholesterolemia; this is because of the ability of oxysterols, unlike cholesterol, to cross the blood brain barrier (BBB). The key role of oxysterols in AD pathogenesis has been strongly supported by research pointing to their involvement in modulating neuroinflammation, Aβ accumulation, and cell death. This review highlights the key role played by cholesterol and oxysterols in the brain in AD pathogenesis.
Collapse
Affiliation(s)
- Paola Gamba
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Simona Gargiulo
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Erica Staurenghi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| |
Collapse
|
50
|
Valley NA, Robertson EJ, Richmond GL. Twist and turn: effect of stereoconfiguration on the interfacial assembly of polyelectrolytes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14226-14233. [PMID: 25372448 DOI: 10.1021/la5037629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Understanding the conditions that promote the adsorption, assembly, and accumulation of charged macromolecules at the interface between aqueous and hydrophobic liquids is important to a multitude of biological, environmental, and industrial processes. Here, the oil-water interfacial behavior of stereoisomers of polymethacrylic acid (PMA), a model system for both naturally occurring and synthetic polyelectrolytes, is investigated with a combination of vibrational sum-frequency (VSF) spectroscopy, surface tension, and computations. Syndiotactic and isotactic isomers both show rapid adsorption to the oil-water interface with a net orientation indicative of a high degree of ordering. The stereoconfiguration is found to affect whether only a single layer or multiple layers assemble at the interface. Surface tension measurements show additional adsorption for syndiotactic PMA over time. The additional layers do not contribute to the VSF spectrum indicating disorder in all but the initial layer. The isotactic isomer shows no evidence of accumulation at the interface beyond the single ordered layer. Molecular dynamics calculations show marked differences between the two isomers in the orientation of their substituent groups at the interface. The hydrophilic and hydrophobic moieties in the isotactic isomer are easily partitioned to the water and oil phases, respectively, whereas a fair portion of hydrophobic groups remain in the water phase for the syndiotactic PMA. The available hydrophobic contacts in the water phase at the interface are credited with allowing further adsorption.
Collapse
Affiliation(s)
- Nicholas A Valley
- Department of Chemistry, University of Oregon , Eugene, Oregon 97403, United States
| | | | | |
Collapse
|