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Johansson B, Oasa S, Muntsant Soria A, Tiiman A, Söderberg L, Amandius E, Möller C, Lannfelt L, Terenius L, Giménez-Llort L, Vukojević V. The interwoven fibril-like structure of amyloid-beta plaques in mouse brain tissue visualized using super-resolution STED microscopy. Cell Biosci 2023; 13:142. [PMID: 37542303 PMCID: PMC10403925 DOI: 10.1186/s13578-023-01086-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/14/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Standard neuropathologic analysis of Alzheimer's brain relies on traditional fluorescence microscopy, which suffers from limited spatial resolution due to light diffraction. As a result, it fails to reveal intricate details of amyloid plaques. While electron microscopy (EM) offers higher resolution, its extensive sample preparation, involving fixation, dehydration, embedding, and sectioning, can introduce artifacts and distortions in the complex brain tissue. Moreover, EM lacks molecular specificity and has limited field of view and imaging depth. RESULTS In our study, we employed super-resolution Stimulated Emission Depletion (STED) microscopy in conjunction with the anti-human APP recombinant antibody 1C3 fluorescently labelled with DyLightTM633 (1C3-DyLight633). This combination allowed us to visualize amyloidogenic aggregates in vitro and in brain sections from a 17-month-old 3×Tg-AD mouse with sub-diffraction limited spatial resolution. Remarkably, we achieved a spatial resolution of 29 nm in vitro and 62 nm in brain tissue sections, surpassing the capabilities of conventional confocal microscopy by 5-10 times. Consequently, we could discern individual fibrils within plaques, an achievement previously only possible with EM. CONCLUSIONS The utilization of STED microscopy represents a groundbreaking advancement in the field, enabling researchers to delve into the characterization of local mechanisms that underlie Amyloid (Aβ) deposition into plaques and their subsequent clearance. This unprecedented level of detail is especially crucial for comprehending the etiology of Alzheimer's disease and developing the next generation of anti-amyloid treatments. By facilitating the evaluation of drug candidates and non-pharmacological interventions aiming to reduce amyloid burden, STED microscopy emerges as an indispensable tool for driving scientific progress in Alzheimer's research.
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Affiliation(s)
- Björn Johansson
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden
- Theme Aging, Karolinska University Hospital, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - Sho Oasa
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - Aida Muntsant Soria
- Institut de Neurociències, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
- Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Ann Tiiman
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | | | | | | | | | - Lars Terenius
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden
| | - Lydia Giménez-Llort
- Institut de Neurociències, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
- Department of Psychiatry and Forensic Medicine, School of Medicine, Universitat Autònoma de Barcelona, 08193, Barcelona, Spain
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Karolinska Institutet, SE-17176, Stockholm, Sweden.
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Oasa S, Kouznetsova VL, Tiiman A, Vukojević V, Tsigelny IF, Terenius L. Small Molecule Decoys of Aggregation for Elimination of Aβ-Peptide Toxicity. ACS Chem Neurosci 2023; 14:1575-1584. [PMID: 37058367 PMCID: PMC10161222 DOI: 10.1021/acschemneuro.2c00649] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023] Open
Abstract
Several lines of evidence suggest that a characteristic of the neuropathology of Alzheimer's disease (AD) is the aggregation of the amyloid beta peptides (Aβ), fragments of the human amyloid precursor protein (hAPP). The dominating species are the Aβ40 and Aβ42 fragments with 40 and 42 amino acids, respectively. Aβ initially forms soluble oligomers that continue to expand to protofibrils, suggestively the neurotoxic intermediates, and thereafter turn into insoluble fibrils that are markers of the disease. Using the powerful tool of pharmacophore simulation, we selected small molecules not known to possess central nervous system (CNS) activity but that might interact with Aβ aggregation, from the NCI Chemotherapeutic Agents Repository, Bethesda, MD. We assessed the activity of these compounds on Aβ aggregation using the thioflavin T fluorescence correlation spectroscopy (ThT-FCS) assay. Förster resonance energy transfer-based fluorescence correlation spectroscopy (FRET-FCS) was used to characterize the dose-dependent activity of selected compounds at an early stage of Aβ aggregation. Transmission electron microscopy (TEM) confirmed that the interfering substances block fibril formation and identified the macrostructures of Aβ aggregates formed in their presence. We first found three compounds generating protofibrils with branching and budding never observed in the control. One compound generated a two-dimensional sheet structure and another generated a double-stranded filament. Importantly, these compounds generating protofibrils with altered macrostructure protected against Aβ-induced toxicity in a cell model while showing no toxicity in a model of cognition in normal mice. The data suggest that the active compounds act as decoys turning the aggregation into nontoxic trajectories and pointing toward novel approaches to therapy.
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Affiliation(s)
- Sho Oasa
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Valentina L Kouznetsova
- San Diego Supercomputer Center, University of California San Diego, La Jolla, California 92093-0505, United States
| | - Ann Tiiman
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Igor F Tsigelny
- San Diego Supercomputer Center, University of California San Diego, La Jolla, California 92093-0505, United States
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093-0819, United States
| | - Lars Terenius
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska University Hospital, Karolinska Institutet, SE-17176 Stockholm, Sweden
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Aksnes M, Aass HCD, Tiiman A, Terenius L, Bogdanović N, Vukojević V, Knapskog AB. Serum Amyloidogenic Nanoplaques and Cytokines in Alzheimer's Disease: Pilot Study in a Small Naturalistic Memory Clinic Cohort. J Alzheimers Dis 2022; 86:1459-1470. [PMID: 35213378 PMCID: PMC9108575 DOI: 10.3233/jad-215504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Neuroinflammation is a central component of Alzheimer’s disease (AD) and correlates closely with amyloid pathology. Markers of inflammation such as cytokines, and amyloidogenic aggregates, so-called nanoplaques, are both promising biomarker candidates for AD. We have previously shown that there is a relationship between the levels of nanoplaques and cytokines in cerebrospinal fluid, but it is unknown whether this association extends to serum. Objective: Investigate in a naturalistic memory clinic cohort whether the associations between nanoplaques and cytokines in the cerebrospinal fluid extends to serum. Methods: We collected serum from 49 patients assessed for cognitive complaints at the Oslo University Hospital Memory Clinic (15 with clinical AD). We assessed the levels of serum nanoplaques with the novel Thioflavin-T fluorescence correlation spectroscopy (ThT-FCS) assay. Serum levels of nine cytokines (eotaxin-1, granulocyte colony-stimulating factor [G-CSF], interleukin [IL]-6, IL-7, IL-8, monocyte chemoattractant protein-1 (MCP-1), gamma induced protein 10 (IP-10), macrophage inflammatory protein [MIP]-1α, and MIP-1β) were quantified with a multiplex assay and read on a Luminex IS 200 instrument. Results: Serum nanoplaques were not increased in clinical AD patients compared to non-AD memory clinic patients and nanoplaques were not associated with any cytokines. The cytokines IL-8 and G-CSF were increased in patients with clinical AD compared to non-AD patients. Conclusion: In this small pilot study, serum nanoplaques were not associated with serum cytokines. Nanoplaque levels could not be used to separate clinical AD patients from non-AD patients in this unselected memory clinic cohort.
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Affiliation(s)
- Mari Aksnes
- Department of Geriatric Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway
| | | | - Ann Tiiman
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Lars Terenius
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Nenad Bogdanović
- Department of Geriatric Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway.,Department of Neurobiology, Care Science and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Vladana Vukojević
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Anne-Brita Knapskog
- Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Norway
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Aksnes M, Müller EG, Tiiman A, Edwin TH, Terenius L, Revheim ME, Vukojević V, Bogdanović N, Knapskog AB. Amyloidogenic Nanoplaques in Cerebrospinal Fluid: Relationship to Amyloid Brain Uptake and Clinical Alzheimer's Disease in a Memory Clinic Cohort. J Alzheimers Dis 2021; 77:831-842. [PMID: 32741818 PMCID: PMC7592690 DOI: 10.3233/jad-200237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Aggregation of amyloid-β (Aβ) is an early pathological event in Alzheimer's disease (AD). Consequently, measures of pathogenic aggregated Aβ are attractive biomarkers for AD. Here, we use a recently developed Thioflavin-T-Fluorescence Correlation Spectroscopy (ThT-FCS) assay to quantify structured ThT-responsive protein aggregates, so-called nanoplaques, in the cerebrospinal fluid (CSF). OBJECTIVE The overall aim of this work was to assess whether ThT-FCS determined CSF nanoplaque levels could predict amyloid brain uptake as determined by 18F-Flutemetamol PET analysis. Further, we assess whether nanoplaque levels could predict clinical AD. METHODS Nanoplaque levels in the CSF from 54 memory clinic patients were compared between sub-groups classified by 18F-Flutemetamol PET as amyloid-positive or amyloid-negative, and by clinical assessment as AD or non-AD. RESULTS Nanoplaque levels did not differ between amyloid groups and could not predict brain amyloid uptake. However, nanoplaque levels were significantly increased in patients with clinical AD, and were significant predictors for AD when adjusting for age, sex, cognitive function, and apolipoprotein E (APOE) genotype. CONCLUSION The concentration of nanoplaques in the CSF differentiates patients with clinical AD from non-AD patients.
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Affiliation(s)
- Mari Aksnes
- Department of Geriatric Medicine, University of Oslo, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Ebba Glersen Müller
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Nuclear Medicine, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Ann Tiiman
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8: 01, Karolinska Institutet, Stockholm, Sweden
| | - Trine Holt Edwin
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway.,Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Vestfold, Norway
| | - Lars Terenius
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8: 01, Karolinska Institutet, Stockholm, Sweden
| | - Mona-Elisabeth Revheim
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Nuclear Medicine, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Vladana Vukojević
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8: 01, Karolinska Institutet, Stockholm, Sweden
| | - Nenad Bogdanović
- Department of Geriatric Medicine, University of Oslo, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of Neurobiology, Care Science and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Anne-Brita Knapskog
- Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway
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Aksnes M, Aass HCD, Tiiman A, Edwin TH, Terenius L, Bogdanović N, Vukojević V, Knapskog AB. Associations of cerebrospinal fluid amyloidogenic nanoplaques with cytokines in Alzheimer's disease. Transl Neurodegener 2021; 10:18. [PMID: 34099032 PMCID: PMC8186140 DOI: 10.1186/s40035-021-00244-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The aggregation of amyloid β (Aβ) is central in the pathogenesis of Alzheimer's disease (AD). Recently it has been shown that specifically, larger, Thioflavin T-binding Aβ aggregates are associated with increased neuroinflammation and cytokine release. This study was aimed to quantify fibrillary amyloid aggregates, so-called nanoplaques, and investigate their relationship with cytokines in the cerebrospinal fluid (CSF). METHODS CSF was collected from 111 patients assessed for cognitive complaints at the Oslo University Hospital Memory Clinic. The patients were grouped based on their amyloid status. The CSF nanoplaque concentration was quantified with the Thioflavin T-fluorescence correlation spectroscopy (ThT-FCS) assay. The levels of nine cytokines (eotaxin-1, granulocyte stimulating factor, interleukin [IL]-6, IL-7, IL-8, monocyte chemoattractant protein-1, gamma-induced protein 10, macrophage inflammatory protein [MIP]-1α, and MIP-1β) were quantified with a magnetic bead-based multiplex assay and read on a Luminex IS 200 instrument. RESULTS There were 49 amyloid-negative and 62 amyloid-positive patients in the cohort; none of the cytokines differed significantly between the amyloid groups. The increased nanoplaque levels were associated with levels of MIP-1β below the lower limit of quantification, and with decreased levels of MIP-1α and IL-8. The associations remained significant when adjusted for age, sex, cognitive function, apolipoprotein ε4 status and CSF core biomarker levels. CONCLUSION The cytokine levels were not associated with amyloid status in this cohort. The nanoplaque levels were negatively associated with MIP-1β, MIP-1α and IL-8, which is in line with recent findings suggesting that the upregulation of some cytokine markers has a protective role and is negatively associated with AD progression.
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Affiliation(s)
- Mari Aksnes
- Department of Geriatric Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | | | - Ann Tiiman
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Trine Holt Edwin
- Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway.,Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway.,Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Tønsberg, Norway
| | - Lars Terenius
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Nenad Bogdanović
- Department of Neurobiology, Care Science and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Vladana Vukojević
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Anne-Brita Knapskog
- Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway
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Leppert A, Tiiman A, Kronqvist N, Landreh M, Abelein A, Vukojević V, Johansson J. Smallest Secondary Nucleation Competent Aβ Aggregates Probed by an ATP-Independent Molecular Chaperone Domain. Biochemistry 2021; 60:678-688. [PMID: 33621049 PMCID: PMC8028046 DOI: 10.1021/acs.biochem.1c00003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein oligomerization is a commonly encountered strategy by which the functional repertoire of proteins is increased. This, however, is a double-edged sword strategy because protein oligomerization is notoriously difficult to control. Living organisms have therefore developed a number of chaperones that prevent protein aggregation. The small ATP-independent molecular chaperone domain proSP-C BRICHOS, which is mainly trimeric, specifically inhibits fibril surface-catalyzed nucleation reactions that give rise to toxic oligomers during the aggregation of the Alzheimer's disease-related amyloid-β peptide (Aβ42). Here, we have created a stable proSP-C BRICHOS monomer mutant and show that it does not bind to monomeric Aβ42 but has a high affinity for Aβ42 fibrils, using surface plasmon resonance. Kinetic analysis of Aβ42 aggregation profiles, measured by thioflavin T fluorescence, reveals that the proSP-C BRICHOS monomer mutant strongly inhibits secondary nucleation reactions and thereby reduces the level of catalytic formation of toxic Aβ42 oligomers. To study binding between the proSP-C BRICHOS monomer mutant and small soluble Aβ42 aggregates, we analyzed fluorescence cross-correlation spectroscopy measurements with the maximum entropy method for fluorescence correlation spectroscopy. We found that the proSP-C BRICHOS monomer mutant binds to the smallest emerging Aβ42 aggregates that are comprised of eight or fewer Aβ42 molecules, which are already secondary nucleation competent. Our approach can be used to provide molecular-level insights into the mechanisms of action of substances that interfere with protein aggregation.
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Affiliation(s)
- Axel Leppert
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, 14183 Huddinge, Sweden
| | - Ann Tiiman
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Nina Kronqvist
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, 14183 Huddinge, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Biomedicum, Solnavägen 9, 17165 Solna, Sweden
| | - Axel Abelein
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, 14183 Huddinge, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, 17176 Stockholm, Sweden
| | - Jan Johansson
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, 14183 Huddinge, Sweden
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7
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Aksnes M, Tiiman A, Edwin TH, Terenius L, Bogdanović N, Vukojević V, Knapskog AB. Comparison of Cerebrospinal Fluid Amyloidogenic Nanoplaques With Core Biomarkers of Alzheimer's Disease. Front Aging Neurosci 2021; 12:608628. [PMID: 33488383 PMCID: PMC7820807 DOI: 10.3389/fnagi.2020.608628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Accurate biomarkers of Alzheimer’s disease (AD) are essential for early diagnosis and intervention. Available biomarkers are not sufficient to permit the monitoring of AD progression over time, and additional biomarkers are required. Measures of aggregated amyloid-β (Aβ) could be useful biomarkers for AD. Here, we investigate whether levels of Thioflavin-T (ThT) positive amyloid aggregates, i.e., nanoplaques, in cerebrospinal fluid (CSF) could serve as useful biomarkers for AD. One-hundred and eighteen memory clinic patients were AT(N) classified, and CSF nanoplaque concentrations were compared between patients on the “Alzheimer’s continuum” (A+ patients) and patients with “Normal AD biomarkers” or “Non-AD pathologic change” (A− patients). CSF nanoplaque concentrations and sizes were quantified using the novel ThT-Fluorescence Correlation Spectroscopy (ThT-FCS) assay, and core biomarkers (Aβ42, total tau and phosphorylated tau) were determined by enzyme-linked immunosorbent assays. We investigated the association between nanoplaque concentrations and core biomarkers, and the diagnostic value of nanoplaque levels. Nanoplaque levels were increased in A+ patients compared to A− patients. Nanoplaque concentrations were negatively associated with Aβ42, but not related to total tau or phosphorylated tau measures. Quantification of nanoplaques did not improve the classification of patients on the Alzheimer’s continuum compared to the core biomarkers alone. Dynamic changes in nanoplaques concentration and size throughout AD stages should be explored in longitudinal studies.
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Affiliation(s)
- Mari Aksnes
- Department of Geriatric Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Ann Tiiman
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Trine Holt Edwin
- Institute of Health and Society, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway.,Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Oslo, Norway
| | - Lars Terenius
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Nenad Bogdanović
- Department of Neurobiology, Care Science and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Vladana Vukojević
- Department of Clinical Neurosciences (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Anne-Brita Knapskog
- Department of Geriatric Medicine, The Memory Clinic, Oslo University Hospital, Oslo, Norway
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Aksnes M, Tiiman A, Edwin TH, Terenius L, Bogdanovic N, Vukojevic V, Knapskog A. Amyloidogenic nanoplaque levels are increased in the cerebrospinal fluid in Alzheimer’s disease. Alzheimers Dement 2020. [DOI: 10.1002/alz.042828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Trine Holt Edwin
- Oslo University Hospital Oslo Norway
- Norwegian National Advisory Unit on Ageing and Health Vestfold Hospital Trust Sem Norway
- Faculty of Medicine University of Oslo Oslo Norway
| | | | - Nenad Bogdanovic
- Karolinska University Hospital Stockholm Sweden
- Karolinska Insitutet, NVS Stockholm Sweden
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9
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Tiiman A, Jelić V, Jarvet J, Järemo P, Bogdanović N, Rigler R, Terenius L, Gräslund A, Vukojević V. Amyloidogenic Nanoplaques in Blood Serum of Patients with Alzheimer's Disease Revealed by Time-Resolved Thioflavin T Fluorescence Intensity Fluctuation Analysis. J Alzheimers Dis 2020; 68:571-582. [PMID: 30814355 PMCID: PMC6484272 DOI: 10.3233/jad-181144] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Biomarkers are central to current research on molecular mechanisms underlying Alzheimer's disease (AD). Their further development is of paramount importance for understanding pathophysiological processes that eventually lead to disease onset. Biomarkers are also crucial for early disease detection, before clinical manifestation, and for development of new disease modifying therapies. OBJECTIVE The overall aim of this work is to develop a minimally invasive method for fast, ultra-sensitive and cost-effective detection of structurally modified peptide/protein self-assemblies in the peripheral blood and in other biological fluids. Specifically, we focus here on using this method to detect structured amyloidogenic oligomeric aggregates in the blood serum of apparently healthy individuals and patients in early AD stage, and measure their concentration and size. METHODS Time-resolved detection of Thioflavin T (ThT) fluorescence intensity fluctuations in a sub-femtoliter observation volume element was used to identify in blood serum ThT-active structured amyloidogenic oligomeric aggregates, hereafter called nanoplaques, and measure with single-particle sensitivity their concentration and size. RESULTS The concentration and size of structured amyloidogenic nanoplaques are significantly higher in the blood serum of individuals diagnosed with AD than in control subjects. CONCLUSION A new method with the ultimate, single-particle sensitivity was successfully developed. The proposed approach neither relies on the use of immune-based probes, nor on the use of radiotracers, signal-amplification or protein separation techniques, and provides a minimally invasive test for fast and cost-effective early determination of structurally modified peptides/proteins in the peripheral blood, as shown here, but also in other biological fluids.
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Affiliation(s)
- Ann Tiiman
- Department of Clinical Neuroscience (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Vesna Jelić
- Department of Neurobiology, Care Sciences and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Jüri Jarvet
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Stockholm, Sweden.,The National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Petter Järemo
- Department of Internal Medicine, The Vrinnevi Hospital, Norrköping, Sweden
| | - Nenad Bogdanović
- Department of Neurobiology, Care Sciences and Society (NVS), Division of Clinical Geriatrics, Karolinska Institutet, Huddinge, Sweden.,Department of Geriatric Medicine, University of Oslo, Oslo, Norway
| | - Rudolf Rigler
- Department of Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Stockholm, Sweden
| | - Lars Terenius
- Department of Clinical Neuroscience (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, Stockholm, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience (CNS), Center for Molecular Medicine CMM L8:01, Karolinska Institutet, Stockholm, Sweden
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10
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Bonito-Oliva A, Schedin-Weiss S, Younesi SS, Tiiman A, Adura C, Paknejad N, Brendel M, Romin Y, Parchem RJ, Graff C, Vukojević V, Tjernberg LO, Terenius L, Winblad B, Sakmar TP, Graham WV. Conformation-specific antibodies against multiple amyloid protofibril species from a single amyloid immunogen. J Cell Mol Med 2019; 23:2103-2114. [PMID: 30663210 PMCID: PMC6378190 DOI: 10.1111/jcmm.14119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/28/2018] [Accepted: 12/07/2018] [Indexed: 12/01/2022] Open
Abstract
We engineered and employed a chaperone‐like amyloid‐binding protein Nucleobindin 1 (NUCB1) to stabilize human islet amyloid polypeptide (hIAPP) protofibrils for use as immunogen in mice. We obtained multiple monoclonal antibody (mAb) clones that were reactive against hIAPP protofibrils. A secondary screen was carried out to identify clones that cross‐reacted with amyloid beta‐peptide (Aβ42) protofibrils, but not with Aβ40 monomers. These mAbs were further characterized in several in vitro assays, in immunohistological studies of a mouse model of Alzheimer's disease (AD) and in AD patient brain tissue. We show that mAbs obtained by immunizing mice with the NUCB1‐hIAPP complex cross‐react with Aβ42, specifically targeting protofibrils and inhibiting their further aggregation. In line with conformation‐specific binding, the mAbs appear to react with an intracellular antigen in diseased tissue, but not with amyloid plaques. We hypothesize that the mAbs we describe here recognize a secondary or quaternary structural epitope that is common to multiple amyloid protofibrils. In summary, we report a method to create mAbs that are conformation‐sensitive and sequence‐independent and can target more than one type of protofibril species.
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Affiliation(s)
- Alessandra Bonito-Oliva
- Laboratory of Chemical Biology & Signal Transduction, The Rockefeller University, New York City, New York
| | - Sophia Schedin-Weiss
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - Shahab S Younesi
- Department of Neuroscience, Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas
| | - Ann Tiiman
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Carolina Adura
- High Throughput and Spectroscopy Resource Center, The Rockefeller University, New York City, New York
| | - Navid Paknejad
- Molecular Cytology Core Facility, Memorial Sloan-Kettering Cancer Center, New York City, New York
| | - Matt Brendel
- Molecular Cytology Core Facility, Memorial Sloan-Kettering Cancer Center, New York City, New York
| | - Yevgeniy Romin
- Molecular Cytology Core Facility, Memorial Sloan-Kettering Cancer Center, New York City, New York
| | - Ronald J Parchem
- Department of Neuroscience, Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas
| | - Caroline Graff
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden.,Theme Aging, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Lars O Tjernberg
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - Lars Terenius
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Bengt Winblad
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - Thomas P Sakmar
- Laboratory of Chemical Biology & Signal Transduction, The Rockefeller University, New York City, New York.,Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - W Vallen Graham
- Laboratory of Chemical Biology & Signal Transduction, The Rockefeller University, New York City, New York
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11
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Jarvet J, Gräslund A, Tiiman A, Vukoevic V. Monitoring of Alzheimer's Amyloid-β Peptide Aggregation via Fluorescence Correlation Spectroscopy and Total Internal Reflection Microscopy. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [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
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14
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Tiiman A, Jarvet J, Gräslund A, Vukojević V. Heterogeneity and Turnover of Intermediates during Amyloid-β (Aβ) Peptide Aggregation Studied by Fluorescence Correlation Spectroscopy. Biochemistry 2015; 54:7203-11. [PMID: 26574169 DOI: 10.1021/acs.biochem.5b00976] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Self-assembly of amyloid β (Aβ) peptide molecules into large aggregates is a naturally occurring process driven in aqueous solution by a dynamic interplay between hydrophobic interactions among Aβ molecules, which promote aggregation, and steric and overall electrostatic hindrance, which stifles it. Aβ self-association is entropically unfavorable, as it implies order increase in the system, but under favorable kinetic conditions, the process proceeds at appreciable rates, yielding Aβ aggregates of different sizes and structures. Despite the great relevance and extensive research efforts, detailed kinetic mechanisms underlying Aβ aggregation remain only partially understood. In this study, fluorescence correlation spectroscopy (FCS) and Thioflavin T (ThT) were used to monitor the time dependent growth of structured aggregates and characterize multiple components during the aggregation of Aβ peptides in a heterogeneous aqueous solution. To this aim, we collected data during a relatively large number of observation periods, 30 consecutive measurements lasting 10 s each, at what we consider to be a constant time point in the slow aggregation process. This approach enabled monitoring the formation of nanomolar concentrations of structured amyloid aggregates and demonstrated the changing distribution of amyloid aggregate sizes throughout the aggregation process. We identified aggregates of different sizes with molecular weight from 260 to more than 1 × 10(6) kDa and revealed the hitherto unobserved kinetic turnover of intermediates during Aβ aggregation. The effect of different Aβ concentrations, Aβ:ThT ratios, differences between the 40 (Aβ40) and 42 (Aβ42) residue long variants of Aβ, and the effect of stirring were also examined.
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Affiliation(s)
- Ann Tiiman
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University , 10691 Stockholm, Sweden
| | - Jüri Jarvet
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University , 10691 Stockholm, Sweden.,The National Institute of Chemical Physics and Biophysics , Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University , 10691 Stockholm, Sweden
| | - Vladana Vukojević
- Department of Clinical Neuroscience, Center for Molecular Medicine CMM L8:01, Karolinska Institutet , 17176 Stockholm, Sweden
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Friedemann M, Helk E, Tiiman A, Zovo K, Palumaa P, Tõugu V. Oxidation of Methionine-35 in Alzheimer’s amyloid-beta peptide and the aggregation of the oxidized peptide. SpringerPlus 2015. [PMCID: PMC4797062 DOI: 10.1186/2193-1801-4-s1-p13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Friedemann M, Helk E, Tiiman A, Zovo K, Palumaa P, Tõugu V. Effect of methionine-35 oxidation on the aggregation of amyloid-β peptide. Biochem Biophys Rep 2015; 3:94-99. [PMID: 29124171 PMCID: PMC5668694 DOI: 10.1016/j.bbrep.2015.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 07/22/2015] [Accepted: 07/28/2015] [Indexed: 01/12/2023] Open
Abstract
Aggregation of Aβ peptides into amyloid plaques is considered to trigger the Alzheimer’s disease (AD), however the mechanism behind the AD onset has remained elusive. It is assumed that the insoluble Aβ aggregates enhance oxidative stress (OS) by generating free radicals with the assistance of bound copper ions. The aim of our study was to establish the role of Met35 residue in the oxidation and peptide aggregation processes. Met35 can be readily oxidized by H2O2. The fibrillization of Aβ with Met35 oxidized to sulfoxide was three times slower compared to that of the regular peptide. The fibrils of regular and oxidized peptides looked similar under transmission electron microscopy. The relatively small inhibitory effect of methionine oxidation on the fibrillization suggests that the possible variation in the Met oxidation state should not affect the in vivo plaque formation. The peptide oxidation pattern was more complex when copper ions were present: addition of one oxygen atom was still the fastest process, however, it was accompanied by multiple unspecific modifications of peptide residues. Addition of copper ions to the Aβ with oxidized Met35 in the presence of H2O2, resulted a similar pattern of nonspecific modifications, suggesting that the one-electron oxidation processes in the peptide molecule do not depend on the oxidation state of Met35 residue. Thus, it can be concluded that Met35 residue is not a part of the radical generating mechanism of Aβ–Cu(II) complex. Aβ peptides with oxidized Met35 residue fibrillize three times slower than the reduced peptide. Met35 is the only residue in Aβ peptide that is oxidized by H2O2 in the absent of copper ions. In the presence of copper ions as catalyst multiple unspecific oxidative processes occur in Aβ. Previous oxidation of Met35 does not affect the unspecific oxidation in the presence of copper ions.
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Key Words
- AD, Alzheimer's disease
- Alzheimer's disease
- Aβ, Alzheimer's amyloid peptide
- Copper(II)ion
- HFIP, 1,1,1,3,3,3-hexafluoro-2-propanol
- Methionine oxidation
- OS, oxidative stress
- ROS, reactive oxygen species
- ThT, Thioflavin T
- β-amyloid
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Affiliation(s)
- Merlin Friedemann
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Eneken Helk
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Ann Tiiman
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Kairit Zovo
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Peep Palumaa
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Vello Tõugu
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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Abelein A, Abrahams JP, Danielsson J, Gräslund A, Jarvet J, Luo J, Tiiman A, Wärmländer SKTS. The hairpin conformation of the amyloid β peptide is an important structural motif along the aggregation pathway. J Biol Inorg Chem 2014; 19:623-34. [PMID: 24737040 DOI: 10.1007/s00775-014-1131-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 04/02/2014] [Indexed: 12/29/2022]
Abstract
The amyloid β (Aβ) peptides are 39-42 residue-long peptides found in the senile plaques in the brains of Alzheimer's disease (AD) patients. These peptides self-aggregate in aqueous solution, going from soluble and mainly unstructured monomers to insoluble ordered fibrils. The aggregation process(es) are strongly influenced by environmental conditions. Several lines of evidence indicate that the neurotoxic species are the intermediate oligomeric states appearing along the aggregation pathways. This minireview summarizes recent findings, mainly based on solution and solid-state NMR experiments and electron microscopy, which investigate the molecular structures and characteristics of the Aβ peptides at different stages along the aggregation pathways. We conclude that a hairpin-like conformation constitutes a common motif for the Aβ peptides in most of the described structures. There are certain variations in different hairpin conformations, for example regarding H-bonding partners, which could be one reason for the molecular heterogeneity observed in the aggregated systems. Interacting hairpins are the building blocks of the insoluble fibrils, again with variations in how hairpins are organized in the cross-section of the fibril, perpendicular to the fibril axis. The secondary structure propensities can be seen already in peptide monomers in solution. Unfortunately, detailed structural information about the intermediate oligomeric states is presently not available. In the review, special attention is given to metal ion interactions, particularly the binding constants and ligand structures of Aβ complexes with Cu(II) and Zn(II), since these ions affect the aggregation process(es) and are considered to be involved in the molecular mechanisms underlying AD pathology.
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Affiliation(s)
- Axel Abelein
- Department of Biochemistry and Biophysics, Arrhenius Laboratories, Stockholm University, 106 91, Stockholm, Sweden
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Wärmländer S, Tiiman A, Abelein A, Luo J, Jarvet J, Söderberg KL, Danielsson J, Gräslund A. Biophysical studies of the amyloid β-peptide: interactions with metal ions and small molecules. Chembiochem 2013; 14:1692-704. [PMID: 23983094 DOI: 10.1002/cbic.201300262] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease is the most common of the protein misfolding ("amyloid") diseases. The deposits in the brains of afflicted patients contain as a major fraction an aggregated insoluble form of the so-called amyloid β-peptides (Aβ peptides): fragments of the amyloid precursor protein of 39-43 residues in length. This review focuses on biophysical studies of the Aβ peptides: that is, of the aggregation pathways and intermediates observed during aggregation, of the molecular structures observed along these pathways, and of the interactions of Aβ with Cu and Zn ions and with small molecules that modify the aggregation pathways. Particular emphasis is placed on studies based on high-resolution and solid-state NMR methods. Theoretical studies relating to the interactions are also included. An emerging picture is that of Aβ peptides in aqueous solution undergoing hydrophobic collapse together with identical partners. There then follows a relatively slow process leading to more ordered secondary and tertiary (quaternary) structures in the growing aggregates. These aggregates eventually assemble into elongated fibrils visible by electron microscopy. Small molecules or metal ions that interfere with the aggregation processes give rise to a variety of aggregation products that may be studied in vitro and considered in relation to observations in cell cultures or in vivo. Although the heterogeneous nature of the processes makes detailed structural studies difficult, knowledge and understanding of the underlying physical chemistry might provide a basis for future therapeutic strategies against the disease. A final part of the review deals with the interactions that may occur between the Aβ peptides and the prion protein, where the latter is involved in other protein misfolding diseases.
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Affiliation(s)
- Sebastian Wärmländer
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories, Stockholm University, 106 91 Stockholm (Sweden)
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Tiiman A, Noormägi A, Friedemann M, Krishtal J, Palumaa P, Tõugu V. Effect of agitation on the peptide fibrillization: Alzheimer's amyloid-β peptide 1-42 but not amylin and insulin fibrils can grow under quiescent conditions. J Pept Sci 2013; 19:386-91. [PMID: 23609985 DOI: 10.1002/psc.2513] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 03/11/2013] [Indexed: 11/08/2022]
Abstract
Many peptides and proteins can form fibrillar aggregates in vitro, but only a limited number of them are forming pathological amyloid structures in vivo. We studied the fibrillization of four peptides--Alzheimer's amyloid-β (Aβ) 1-40 and 1-42, amylin and insulin. In all cases, intensive mechanical agitation of the solution initiated fast fibrillization. However, when the mixing was stopped during the fibril growth phase, the fibrillization of amylin and insulin was practically stopped, and the rate for Aβ40 substantially decreased, whereas the fibrillization of Aβ42 peptide continued to proceed with almost the same rate as in the agitated conditions. The reason for the different sensitivity of the in vitro fibrillization of these peptides towards agitation in the fibril growth phase remains elusive.
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Affiliation(s)
- Ann Tiiman
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn, 12618, Estonia.
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Tiiman A, Palumaa P, Tõugu V. The missing link in the amyloid cascade of Alzheimer's disease - metal ions. Neurochem Int 2013; 62:367-78. [PMID: 23395747 DOI: 10.1016/j.neuint.2013.01.023] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/14/2013] [Accepted: 01/23/2013] [Indexed: 01/23/2023]
Abstract
Progressive deposition of amyloid beta (Aβ) peptides into amyloid plaques is the pathological hallmark of Alzheimer's disease (AD). The amyloid cascade hypothesis pins this deposition as the primary cause of the disease, but the mechanisms that causes this deposition remain elusive. An increasing amount of evidence shows that biometals Zn(II) and Cu(II) can interact with Aβ, thus influencing the fibrillization and toxicity. This review focuses on the role of Zn(II) and Cu(II) in AD, and revisits the amyloid cascade hypothesis demonstrating the possible roles of Zn(II) and Cu(II) in the disease pathogenesis.
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Affiliation(s)
- Ann Tiiman
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn 12618, Estonia.
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Tõugu V, Tiiman A, Palumaa P. Interactions of Zn(ii) and Cu(ii) ions with Alzheimer's amyloid-beta peptide. Metal ion binding, contribution to fibrillization and toxicity. Metallomics 2011; 3:250-61. [DOI: 10.1039/c0mt00073f] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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