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Kell DB, Lip GYH, Pretorius E. Fibrinaloid Microclots and Atrial Fibrillation. Biomedicines 2024; 12:891. [PMID: 38672245 PMCID: PMC11048249 DOI: 10.3390/biomedicines12040891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/27/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Atrial fibrillation (AF) is a comorbidity of a variety of other chronic, inflammatory diseases for which fibrinaloid microclots are a known accompaniment (and in some cases, a cause, with a mechanistic basis). Clots are, of course, a well-known consequence of atrial fibrillation. We here ask the question whether the fibrinaloid microclots seen in plasma or serum may in fact also be a cause of (or contributor to) the development of AF. We consider known 'risk factors' for AF, and in particular, exogenous stimuli such as infection and air pollution by particulates, both of which are known to cause AF. The external accompaniments of both bacterial (lipopolysaccharide and lipoteichoic acids) and viral (SARS-CoV-2 spike protein) infections are known to stimulate fibrinaloid microclots when added in vitro, and fibrinaloid microclots, as with other amyloid proteins, can be cytotoxic, both by inducing hypoxia/reperfusion and by other means. Strokes and thromboembolisms are also common consequences of AF. Consequently, taking a systems approach, we review the considerable evidence in detail, which leads us to suggest that it is likely that microclots may well have an aetiological role in the development of AF. This has significant mechanistic and therapeutic implications.
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Affiliation(s)
- Douglas B. Kell
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Søltofts Plads, Building 220, 2800 Kongens Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
| | - Gregory Y. H. Lip
- Liverpool Centre for Cardiovascular Science at University of Liverpool, Liverpool John Moores University and Liverpool Heart and Chest Hospital, Liverpool L7 8TX, UK;
- Danish Center for Health Services Research, Department of Clinical Medicine, Aalborg University, 9220 Aalborg, Denmark
| | - Etheresia Pretorius
- Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Private Bag X1 Matieland, Stellenbosch 7602, South Africa
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2
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Dabirmanesh B, Khajeh K, Uversky VN. The hidden world of protein aggregation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2024; 206:473-494. [PMID: 38811088 DOI: 10.1016/bs.pmbts.2024.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Though the book's journey into The Hidden World of Protein Aggregation has come to an end, the search for knowledge, the development of healthier lives, and the discovery of nature's mysteries continue, promising new horizons and discoveries yet to be discovered. The intricacies of protein misfolding and aggregation remain a mystery in cellular biology, despite advances made in unraveling them. In this chapter, we will summarize the specific conclusions from the previous chapters and explore the persistent obstacles and unanswered questions that motivate scientists to pursue exploration of protein misfolding and aggregation.
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Affiliation(s)
- Bahareh Dabirmanesh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Khosro Khajeh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Vladimir N Uversky
- Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Institute for Biological Instrumentation, Pushchino, Moscow, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
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3
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Depraz Depland A, Stroganova I, Wootton CA, Rijs AM. Developments in Trapped Ion Mobility Mass Spectrometry to Probe the Early Stages of Peptide Aggregation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:193-204. [PMID: 36633834 PMCID: PMC9896548 DOI: 10.1021/jasms.2c00253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/15/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
Ion mobility mass spectrometry (IM-MS) has proven to be an excellent method to characterize the structure of amyloidogenic protein and peptide aggregates, which are formed in coincidence with the development of neurodegenerative diseases. However, it remains a challenge to obtain detailed structural information on all conformational intermediates, originating from the early onset of those pathologies, due to their complex and heterogeneous environment. One way to enhance the insights and the identification of these early stage oligomers is by employing high resolution ion mobility mass spectrometry experiments. This would allow us to enhance the mobility separation and MS characterization. Trapped ion mobility spectrometry (TIMS) is an ion mobility technique known for its inherently high resolution and has successfully been applied to the analysis of protein conformations among others. To obtain conformational information on fragile peptide aggregates, the instrumental parameters of the TIMS-Quadrupole-Time-of-Flight mass spectrometer (TIMS-qToF-MS) have to be optimized to allow the study of intact aggregates and ensure their transmission toward the detector. Here, we investigate the suitability and application of TIMS to probe the aggregation process, targeting the well-characterized M307-N319 peptide segment of the TDP-43 protein, which is involved in the development of amyotrophic lateral sclerosis. By studying the influence of key parameters over the full mass spectrometer, such as source temperature, applied voltages or RFs among others, we demonstrate that by using an optimized instrumental method TIMS can be used to probe peptide aggregation.
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Affiliation(s)
- Agathe Depraz Depland
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
| | - Iuliia Stroganova
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
| | | | - Anouk M. Rijs
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
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4
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Giampà M, Amundarain MJ, Herrera MG, Tonali N, Dodero VI. Implementing Complementary Approaches to Shape the Mechanism of α-Synuclein Oligomerization as a Model of Amyloid Aggregation. Molecules 2021; 27:88. [PMID: 35011320 PMCID: PMC8747028 DOI: 10.3390/molecules27010088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022] Open
Abstract
The aggregation of proteins into amyloid fibers is linked to more than forty still incurable cellular and neurodegenerative diseases such as Parkinson's disease (PD), multiple system atrophy, Alzheimer's disease and type 2 diabetes, among others. The process of amyloid formation is a main feature of cell degeneration and disease pathogenesis. Despite being methodologically challenging, a complete understanding of the molecular mechanism of aggregation, especially in the early stages, is essential to find new biological targets for innovative therapies. Here, we reviewed selected examples on α-syn showing how complementary approaches, which employ different biophysical techniques and models, can better deal with a comprehensive study of amyloid aggregation. In addition to the monomer aggregation and conformational transition hypothesis, we reported new emerging theories regarding the self-aggregation of α-syn, such as the alpha-helix rich tetramer hypothesis, whose destabilization induce monomer aggregation; and the liquid-liquid phase separation hypothesis, which considers a phase separation of α-syn into liquid droplets as a primary event towards the evolution to aggregates. The final aim of this review is to show how multimodal methodologies provide a complete portrait of α-syn oligomerization and can be successfully extended to other protein aggregation diseases.
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Affiliation(s)
- Marco Giampà
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7491 Trondheim, Norway;
| | - María J. Amundarain
- Instituto de Física del Sur (IFISUR), Departamento de Física, Universidad Nacional del Sur (UNS), CONICET, Av. L. N. Alem 1253, Bahía Blanca B8000CPB, Argentina;
| | - Maria Georgina Herrera
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Nicolò Tonali
- BioCIS, CNRS, Faculté de Pharmacie, Université Paris-Saclay, 92290 Châtenay-Malabry, France
| | - Veronica I. Dodero
- Organic and Bioorganic Chemistry, Chemistry Department, Bielefeld University, Universitätstr. 25, 33615 Bielefeld, Germany
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5
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Dasmeh P, Wagner A. Yeast Proteins may Reversibly Aggregate like Amphiphilic Molecules. J Mol Biol 2021; 434:167352. [PMID: 34774567 DOI: 10.1016/j.jmb.2021.167352] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/18/2021] [Accepted: 11/07/2021] [Indexed: 11/30/2022]
Abstract
More than a hundred proteins in yeast reversibly aggregate and phase-separate in response to various stressors, such as nutrient depletion and heat shock. We know little about the protein sequence and structural features behind this ability, which has not been characterized on a proteome-wide level. To identify the distinctive features of aggregation-prone protein regions, we apply machine learning algorithms to genome-scale limited proteolysis-mass spectrometry (LiP-MS) data from yeast proteins. LiP-MS data reveals that 96 proteins show significant structural changes upon heat shock. We find that in these proteins the propensity to phase separate cannot be solely driven by disordered regions, because their aggregation-prone regions (APRs) are not significantly disordered. Instead, the phase separation of these proteins requires contributions from both disordered and structured regions. APRs are significantly enriched in aliphatic residues and depleted in positively charged amino acids. Aggregator proteins with longer APRs show a greater propensity to aggregate, a relationship that can be explained by equilibrium statistical thermodynamics. Altogether, our observations suggest that proteome-wide reversible protein aggregation is mediated by sequence-encoded properties. We propose that aggregating proteins resemble supra-molecular amphiphiles, where APRs are the hydrophobic parts, and non-APRs are the hydrophilic parts.
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Affiliation(s)
- Pouria Dasmeh
- Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02139, USA; Swiss Institute of Bioinformatics (SIB), Switzerland.
| | - Andreas Wagner
- Institute for Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland; The Santa Fe Institute, Santa Fe, NM, USA; Swiss Institute of Bioinformatics (SIB), Switzerland; Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch 7600, South Africa.
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6
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Mallucci GR, Klenerman D, Rubinsztein DC. Developing Therapies for Neurodegenerative Disorders: Insights from Protein Aggregation and Cellular Stress Responses. Annu Rev Cell Dev Biol 2021; 36:165-189. [PMID: 33021824 DOI: 10.1146/annurev-cellbio-040320-120625] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
As the world's population ages, neurodegenerative disorders are poised to become the commonest cause of death. Despite this, they remain essentially untreatable. Characterized pathologically both by the aggregation of disease-specific misfolded proteins and by changes in cellular stress responses, to date, therapeutic approaches have focused almost exclusively on reducing misfolded protein load-notably amyloid beta (Aβ) in Alzheimer's disease. The repeated failure of clinical trials has led to despondency over the possibility that these disorders will ever be treated. We argue that this is in fact a time for optimism: Targeting various generic stress responses is emerging as an increasingly promising means of modifying disease progression across these disorders. New treatments are approaching clinical trials, while novel means of targeting aggregates could eventually act preventively in early disease.
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Affiliation(s)
- Giovanna R Mallucci
- UK Dementia Research Institute at the University of Cambridge, Cambridge CB2 0AH, United Kingdom; .,Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AH, United Kingdom
| | - David Klenerman
- UK Dementia Research Institute at the University of Cambridge, Cambridge CB2 0AH, United Kingdom; .,Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - David C Rubinsztein
- UK Dementia Research Institute at the University of Cambridge, Cambridge CB2 0AH, United Kingdom; .,Cambridge Institute for Medical Research, Cambridge CB2 0XY, United Kingdom
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7
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Jin Y, Vadukul DM, Gialama D, Ge Y, Thrush R, White JT, Aprile FA. The Diagnostic Potential of Amyloidogenic Proteins. Int J Mol Sci 2021; 22:4128. [PMID: 33923609 PMCID: PMC8074075 DOI: 10.3390/ijms22084128] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative disorders are a highly prevalent class of diseases, whose pathological mechanisms start before the appearance of any clear symptoms. This fact has prompted scientists to search for biomarkers that could aid early treatment. These currently incurable pathologies share the presence of aberrant aggregates called amyloids in the nervous system, which are composed of specific proteins. In this review, we discuss how these proteins, their conformations and modifications could be exploited as biomarkers for diagnostic purposes. We focus on proteins that are associated with the most prevalent neurodegenerative disorders, including Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, and frontotemporal dementia. We also describe current challenges in detection, the most recent techniques with diagnostic potentials and possible future developments in diagnosis.
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Affiliation(s)
| | | | | | | | | | | | - Francesco Antonio Aprile
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK; (Y.J.); (D.M.V.); (D.G.); (Y.G.); (R.T.); (J.T.W.)
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8
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Kulenkampff K, Wolf Perez AM, Sormanni P, Habchi J, Vendruscolo M. Quantifying misfolded protein oligomers as drug targets and biomarkers in Alzheimer and Parkinson diseases. Nat Rev Chem 2021; 5:277-294. [PMID: 37117282 DOI: 10.1038/s41570-021-00254-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 02/06/2023]
Abstract
Protein misfolding and aggregation are characteristic of a wide range of neurodegenerative disorders, including Alzheimer and Parkinson diseases. A hallmark of these diseases is the aggregation of otherwise soluble and functional proteins into amyloid aggregates. Although for many decades such amyloid deposits have been thought to be responsible for disease progression, it is now increasingly recognized that the misfolded protein oligomers formed during aggregation are, instead, the main agents causing pathological processes. These oligomers are transient and heterogeneous, which makes it difficult to detect and quantify them, generating confusion about their exact role in disease. The lack of suitable methods to address these challenges has hampered efforts to investigate the molecular mechanisms of oligomer toxicity and to develop oligomer-based diagnostic and therapeutic tools to combat protein misfolding diseases. In this Review, we describe methods to quantify misfolded protein oligomers, with particular emphasis on diagnostic applications as disease biomarkers and on therapeutic applications as target biomarkers. The development of these methods is ongoing, and we discuss the challenges that remain to be addressed to establish measurement tools capable of overcoming existing limitations and to meet present needs.
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9
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Cawood EE, Karamanos TK, Wilson AJ, Radford SE. Visualizing and trapping transient oligomers in amyloid assembly pathways. Biophys Chem 2020; 268:106505. [PMID: 33220582 PMCID: PMC8188297 DOI: 10.1016/j.bpc.2020.106505] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/31/2022]
Abstract
Oligomers which form during amyloid fibril assembly are considered to be key contributors towards amyloid disease. However, understanding how such intermediates form, their structure, and mechanisms of toxicity presents significant challenges due to their transient and heterogeneous nature. Here, we discuss two different strategies for addressing these challenges: use of (1) methods capable of detecting lowly-populated species within complex mixtures, such as NMR, single particle methods (including fluorescence and force spectroscopy), and mass spectrometry; and (2) chemical and biological tools to bias the amyloid energy landscape towards specific oligomeric states. While the former methods are well suited to following the kinetics of amyloid assembly and obtaining low-resolution structural information, the latter are capable of producing oligomer samples for high-resolution structural studies and inferring structure-toxicity relationships. Together, these different approaches should enable a clearer picture to be gained of the nature and role of oligomeric intermediates in amyloid formation and disease. Methods to study structure, toxicity, and kinetics of transient amyloid oligomers. NMR and single particle methods can characterize lowly-populated oligomers. Chemical tools/antibodies stabilize oligomers for structural and toxicity studies A combination of methods is needed to fully characterize amyloid assembly pathways.
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Affiliation(s)
- Emma E Cawood
- Astbury Centre for Structural Molecular Biology, School of Chemistry, University of Leeds, LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK
| | - Theodoros K Karamanos
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK; Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew J Wilson
- Astbury Centre for Structural Molecular Biology, School of Chemistry, University of Leeds, LS2 9JT, UK.
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK.
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10
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Genoud S, Jones MWM, Trist BG, Deng J, Chen S, Hare DJ, Double KL. Simultaneous structural and elemental nano-imaging of human brain tissue. Chem Sci 2020; 11:8919-8927. [PMID: 34123146 PMCID: PMC8163372 DOI: 10.1039/d0sc02844d] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Examining chemical and structural characteristics of micro-features in complex tissue matrices is essential for understanding biological systems. Advances in multimodal chemical and structural imaging using synchrotron radiation have overcome many issues in correlative imaging, enabling the characterization of distinct microfeatures at nanoscale resolution in ex vivo tissues. We present a nanoscale imaging method that pairs X-ray ptychography and X-ray fluorescence microscopy (XFM) to simultaneously examine structural features and quantify elemental content of microfeatures in complex ex vivo tissues. We examined the neuropathological microfeatures Lewy bodies, aggregations of superoxide dismutase 1 (SOD1) and neuromelanin in human post-mortem Parkinson's disease tissue. Although biometals play essential roles in normal neuronal biochemistry, their dyshomeostasis is implicated in Parkinson's disease aetiology. Here we show that Lewy bodies and SOD1 aggregates have distinct elemental fingerprints yet are similar in structure, whilst neuromelanin exhibits different elemental composition and a distinct, disordered structure. The unique approach we describe is applicable to the structural and chemical characterization of a wide range of complex biological tissues at previously unprecedented levels of detail. Structural and chemical characterisation of microfeatures in unadulterated Parkinson's disease brain tissue using synchrotron nanoscale XFM and ptychography.![]()
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Affiliation(s)
- Sian Genoud
- Brain and Mind Centre and Discipline of Pharmacology, The University of Sydney Camperdown NSW 2050 Australia
| | - Michael W M Jones
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology Brisbane QLD 4000 Australia
| | - Benjamin Guy Trist
- Brain and Mind Centre and Discipline of Pharmacology, The University of Sydney Camperdown NSW 2050 Australia
| | - Junjing Deng
- Advanced Photon Source, Argonne National Laboratory Lemont IL 60439 USA
| | - Si Chen
- Advanced Photon Source, Argonne National Laboratory Lemont IL 60439 USA
| | - Dominic James Hare
- Brain and Mind Centre and Discipline of Pharmacology, The University of Sydney Camperdown NSW 2050 Australia .,School of Biosciences, Department of Clinical Pathology, The University of Melbourne Parkville VIC 3010 Australia .,Atomic Medicine Initiative, University of Technology Sydney NSW 2007 Australia
| | - Kay L Double
- Brain and Mind Centre and Discipline of Pharmacology, The University of Sydney Camperdown NSW 2050 Australia
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11
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Taylor AIP, Gahan LD, Chakrabarti B, Staniforth RA. A two-step biopolymer nucleation model shows a nonequilibrium critical point. J Chem Phys 2020; 153:025102. [PMID: 32668930 DOI: 10.1063/5.0009394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Biopolymer self-assembly pathways are complicated by the ability of their monomeric subunits to adopt different conformational states. This means nucleation often involves a two-step mechanism where the monomers first condense to form a metastable intermediate, which then converts to a stable polymer by conformational rearrangement of constituent monomers. Nucleation intermediates play a causative role in amyloid diseases such as Alzheimer's and Parkinson's. While existing mathematical models neglect the conversion dynamics, experiments show that conversion events frequently occur on comparable timescales to the condensation of intermediates and growth of mature polymers and thus cannot be ignored. We present a model that explicitly accounts for simultaneous assembly and conversion. To describe conversion, we propose an experimentally motivated initiation-propagation mechanism in which the stable phase arises locally within the intermediate and then spreads by nearest-neighbor interactions, in a manner analogous to one-dimensional Glauber dynamics. Our analysis shows that the competing timescales of assembly and conversion result in a nonequilibrium critical point, separating a regime where intermediates are kinetically unstable from one where conformationally mixed intermediates accumulate. This strongly affects the accumulation rate of the stable biopolymer phase. Our model is uniquely able to explain experimental phenomena such as the formation of mixed intermediates and abrupt changes in the scaling exponent γ, which relates the total monomer concentration to the accumulation rate of the stable phase. This provides a first step toward a general model of two-step biopolymer nucleation, which can quantitatively predict the concentration and composition of biologically crucial intermediates.
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Affiliation(s)
- Alexander I P Taylor
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Lianne D Gahan
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Buddhapriya Chakrabarti
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Rosemary A Staniforth
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
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12
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Singla R, Abidi SMS, Dar AI, Acharya A. Inhibition of Glycation-Induced Aggregation of Human Serum Albumin by Organic-Inorganic Hybrid Nanocomposites of Iron Oxide-Functionalized Nanocellulose. ACS OMEGA 2019; 4:14805-14819. [PMID: 31552320 PMCID: PMC6751540 DOI: 10.1021/acsomega.9b01392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/31/2019] [Indexed: 05/06/2023]
Abstract
Protein aggregation leads to the transformation of proteins from their soluble form to the insoluble amyloid fibrils and these aggregates get deposited in the specific body tissues, accounting for various diseases. To prevent such an aggregation, organic-inorganic hybrid nanocomposites of iron oxide nanoparticle (NP, ∼6.5-7.0 nm)-conjugated cellulose nanocrystals (CNCs) isolated from Syzygium cumini (SC) and Pinus roxburghii (PR) were chemically synthesized. Transmission electron microscopy (TEM) images of the nanocomposites suggested that the in situ-synthesized iron oxide NPs were bound to the CNC surface in a uniform and regular fashion. The ThT fluorescence assay together with 8-anilino-1-naphthalenesulfonic acid, Congo Red, and CD studies suggested that short fiber-based SC nanocomposites showed better inhibition as well as dissociation of human serum albumin aggregates. The TEM and fluorescence microscopy studies supported similar observations. Native polyacrylamide gel electrophoresis results documented dissociation of higher protein aggregates in the presence of the developed nanocomposite. Interestingly, the dissociated proteins retained their biological function by maintaining a high amount of α-helix content. The in vitro studies with HEK-293 cells suggested that the developed nanocomposite reduces aggregation-induced cytotoxicity by intracellular reactive oxygen species scavenging and maintaining the Ca2+ ion-channel. These results indicated that the hybrid organic-inorganic nanocomposite, with simultaneous sites for hydrophobic and hydrophilic interactions, tends to provide a larger surface area for nanocomposite-protein interactions, which ultimately disfavors the nucleation step for fibrillation for protein aggregates.
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Affiliation(s)
- Rubbel Singla
- Biotechnology
Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India
| | - Syed M. S. Abidi
- Biotechnology
Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India
| | - Aqib Iqbal Dar
- Biotechnology
Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India
| | - Amitabha Acharya
- Biotechnology
Division and Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh 176061, India
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13
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De S, Whiten DR, Ruggeri FS, Hughes C, Rodrigues M, Sideris DI, Taylor CG, Aprile FA, Muyldermans S, Knowles TPJ, Vendruscolo M, Bryant C, Blennow K, Skoog I, Kern S, Zetterberg H, Klenerman D. Soluble aggregates present in cerebrospinal fluid change in size and mechanism of toxicity during Alzheimer's disease progression. Acta Neuropathol Commun 2019; 7:120. [PMID: 31349874 PMCID: PMC6659275 DOI: 10.1186/s40478-019-0777-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 07/18/2019] [Indexed: 01/14/2023] Open
Abstract
Soluble aggregates of amyloid-β (Aβ) have been associated with neuronal and synaptic loss in Alzheimer's disease (AD). However, despite significant recent progress, the mechanisms by which these aggregated species contribute to disease progression are not fully determined. As the analysis of human cerebrospinal fluid (CSF) provides an accessible window into the molecular changes associated with the disease progression, we characterised soluble aggregates present in CSF samples from individuals with AD, mild cognitive impairment (MCI) and healthy controls using a range of sensitive biophysical methods. We used super-resolution imaging and atomic force microscopy to characterise the size and structure of the aggregates present in CSF and correlate this with their ability to permeabilise lipid membranes and induce an inflammatory response. We found that these aggregates are extremely heterogeneous and exist in a range of sizes, varying both structurally and in their mechanisms of toxicity during the disease progression. A higher proportion of small aggregates of Aβ that can cause membrane permeabilization are found in MCI CSF; in established AD, a higher proportion of the aggregates were larger and more prone to elicit a pro-inflammatory response in glial cells, while there was no detectable change in aggregate concentration. These results show that large aggregates, some longer than 100 nm, are present in the CSF of AD patients and suggest that different neurotoxic mechanisms are prevalent at different stages of AD.
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14
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De S, Wirthensohn DC, Flagmeier P, Hughes C, Aprile FA, Ruggeri FS, Whiten DR, Emin D, Xia Z, Varela JA, Sormanni P, Kundel F, Knowles TPJ, Dobson CM, Bryant C, Vendruscolo M, Klenerman D. Different soluble aggregates of Aβ42 can give rise to cellular toxicity through different mechanisms. Nat Commun 2019; 10:1541. [PMID: 30948723 PMCID: PMC6449370 DOI: 10.1038/s41467-019-09477-3] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/13/2019] [Indexed: 01/20/2023] Open
Abstract
Protein aggregation is a complex process resulting in the formation of heterogeneous mixtures of aggregate populations that are closely linked to neurodegenerative conditions, such as Alzheimer's disease. Here, we find that soluble aggregates formed at different stages of the aggregation process of amyloid beta (Aβ42) induce the disruption of lipid bilayers and an inflammatory response to different extents. Further, by using gradient ultracentrifugation assay, we show that the smaller aggregates are those most potent at inducing membrane permeability and most effectively inhibited by antibodies binding to the C-terminal region of Aβ42. By contrast, we find that the larger soluble aggregates are those most effective at causing an inflammatory response in microglia cells and more effectively inhibited by antibodies targeting the N-terminal region of Aβ42. These findings suggest that different toxic mechanisms driven by different soluble aggregated species of Aβ42 may contribute to the onset and progression of Alzheimer's disease.
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Affiliation(s)
- Suman De
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
| | - David C Wirthensohn
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Patrick Flagmeier
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Craig Hughes
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - Francesco A Aprile
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Francesco S Ruggeri
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Daniel R Whiten
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Derya Emin
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Zengjie Xia
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Juan A Varela
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Pietro Sormanni
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Franziska Kundel
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 1HE, UK
| | - Christopher M Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Clare Bryant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - Michele Vendruscolo
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
- UK Dementia Research Institute, University of Cambridge, Cambridge, CB2 0XY, UK.
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