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Bohannon DG, Long D, Okhravi HR, Lee SC, De Jesus CL, Neubert TA, Rostagno AA, Ghiso JA, Kim WK. Functionally distinct pericyte subsets differently regulate amyloid-β deposition in patients with Alzheimer's disease. Brain Pathol 2024:e13282. [PMID: 38932696 DOI: 10.1111/bpa.13282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
Although the concept that the blood-brain barrier (BBB) plays an important role in the etiology and pathogenesis of Alzheimer's disease (AD) has become increasingly accepted, little is known yet about how it actually contributes. We and others have recently identified a novel functionally distinct subset of BBB pericytes (PCs). In the present study, we sought to determine whether these PC subsets differentially contribute to AD-associated pathologies by immunohistochemistry and amyloid beta (Aβ) peptidomics. We demonstrated that a disease-associated PC subset (PC2) expanded in AD patients compared to age-matched, cognitively unimpaired controls. Surprisingly, we found that this increase in the percentage of PC2 (%PC2) was correlated negatively with BBB breakdown in AD patients, unlike in natural aging or other reported disease conditions. The higher %PC2 in AD patients was also correlated with a lower Aβ42 plaque load and a lower Aβ42:Aβ40 ratio in the brain as determined by immunohistochemistry. Colocalization analysis of multicolor confocal immunofluorescence microscopy images suggests that AD patient with low %PC2 have higher BBB breakdown due to internalization of Aβ42 by the physiologically normal PC subset (PC1) and their concomitant cell death leading to more vessels without PCs and increased plaque load. On the contrary, it appears that PC2 can secrete cathepsin D to cleave and degrade Aβ built up outside of PC2 into more soluble forms, ultimately contributing to less BBB breakdown and reducing Aβ plaque load. Collectively our data shows functionally distinct mechanisms for PC1 and PC2 in high Aβ conditions, demonstrating the importance of correctly identifying these populations when investigating the contribution of neurovascular dysfunction to AD pathogenesis.
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Affiliation(s)
- Diana G Bohannon
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Danielle Long
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Hamid R Okhravi
- Glennan Center for Geriatrics and Gerontology, Eastern Virginia Medical School, Norfolk, Virginia, USA
- Integrated Neurodegenerative Disorders Center, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Sunhee C Lee
- Regeneron Pharmaceuticals, Inc, Tarrytown, New York, USA
| | | | - Thomas A Neubert
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Agueda A Rostagno
- Department of Pathology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jorge A Ghiso
- Department of Pathology, New York University Grossman School of Medicine, New York, New York, USA
- Department of Psychiatry, New York University Grossman School of Medicine, New York, New York, USA
| | - Woong-Ki Kim
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia, USA
- Integrated Neurodegenerative Disorders Center, Eastern Virginia Medical School, Norfolk, Virginia, USA
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana, USA
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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2
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Canepa E, Parodi-Rullan R, Vazquez-Torres R, Gamallo-Lana B, Guzman-Hernandez R, Lemon NL, Angiulli F, Debure L, Ilies MA, Østergaard L, Wisniewski T, Gutiérrez-Jiménez E, Mar AC, Fossati S. FDA-approved carbonic anhydrase inhibitors reduce amyloid β pathology and improve cognition, by ameliorating cerebrovascular health and glial fitness. Alzheimers Dement 2023; 19:5048-5073. [PMID: 37186121 PMCID: PMC10600328 DOI: 10.1002/alz.13063] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 05/17/2023]
Abstract
INTRODUCTION Cerebrovascular pathology is an early and causal hallmark of Alzheimer's disease (AD), in need of effective therapies. METHODS Based on the success of our previous in vitro studies, we tested for the first time in a model of AD and cerebral amyloid angiopathy (CAA), the carbonic anhydrase inhibitors (CAIs) methazolamide and acetazolamide, Food and Drug Administration-approved against glaucoma and high-altitude sickness. RESULTS Both CAIs reduced cerebral, vascular, and glial amyloid beta (Aβ) accumulation and caspase activation, diminished gliosis, and ameliorated cognition in TgSwDI mice. The CAIs also improved microvascular fitness and induced protective glial pro-clearance pathways, resulting in the reduction of Aβ deposition. Notably, we unveiled that the mitochondrial carbonic anhydrase-VB (CA-VB) is upregulated in TgSwDI brains, CAA and AD+CAA human subjects, and in endothelial cells upon Aβ treatment. Strikingly, CA-VB silencing specifically reduces Aβ-mediated endothelial apoptosis. DISCUSSION This work substantiates the potential application of CAIs in clinical trials for AD and CAA.
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Affiliation(s)
- Elisa Canepa
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Rebecca Parodi-Rullan
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Rafael Vazquez-Torres
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Begona Gamallo-Lana
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Roberto Guzman-Hernandez
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Nicole L. Lemon
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Federica Angiulli
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Ludovic Debure
- Department on Neurology, Center for Cognitive Neurology, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Marc A. Ilies
- Department of Pharmaceutical Sciences and Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Temple University, Philadelphia, PA, 19140, USA
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark
| | - Thomas Wisniewski
- Department on Neurology, Center for Cognitive Neurology, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Eugenio Gutiérrez-Jiménez
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark
| | - Adam C. Mar
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Silvia Fossati
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
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3
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Pérez Palmer N, Trejo Ortega B, Joshi P. Cognitive Impairment in Older Adults: Epidemiology, Diagnosis, and Treatment. Psychiatr Clin North Am 2022; 45:639-661. [PMID: 36396270 DOI: 10.1016/j.psc.2022.07.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cognitive impairment and dementia affect dozens of millions of people worldwide and cause significant distress to patients and caregivers and a financial burden to families and health care systems. Careful history-taking, cognitive and physical examination, and supplemental neuroimaging and fluid-based biomarkers can accurately diagnose neurocognitive disorders. Management includes non-pharmacological and pharmacological treatments tailored to the etiology and to the individual.
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Affiliation(s)
- Nicolás Pérez Palmer
- Department of Psychiatry, Yale School of Medicine, 300 George Street, Suite 901, New Haven, CT 06511, USA.
| | - Barbara Trejo Ortega
- Department of Psychiatry, Yale School of Medicine, 300 George Street, Suite 901, New Haven, CT 06511, USA
| | - Pallavi Joshi
- Banner Alzheimer's Institute, 901 East Willeta Street, Phoenix, AZ 85006, USA; Department of Psychiatry, University of Arizona College of Medicine-Phoenix, 475 North 5th, Phoenix, AZ 85004, USA
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4
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Davidson DS, Kraus JA, Montgomery JM, Lemkul JA. Effects of Familial Alzheimer's Disease Mutations on the Folding Free Energy and Dipole-Dipole Interactions of the Amyloid β-Peptide. J Phys Chem B 2022; 126:7552-7566. [PMID: 36150020 PMCID: PMC9547858 DOI: 10.1021/acs.jpcb.2c03520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Familial Alzheimer's disease (FAD) mutations of the amyloid β-peptide (Aβ) are known to lead to early onset and more aggressive Alzheimer's disease. FAD mutations such as "Iowa" (D23N), "Arctic" (E22G), "Italian" (E22K), and "Dutch" (E22Q) have been shown to accelerate Aβ aggregation relative to the wild-type (WT). The mechanism by which these mutations facilitate increased aggregation is unknown, but each mutation results in a change in the net charge of the peptide. Previous studies have used nonpolarizable force fields to study Aβ, providing some insight into how this protein unfolds. However, nonpolarizable force fields have fixed charges that lack the ability to redistribute in response to changes in local electric fields. Here, we performed polarizable molecular dynamics simulations on the full-length Aβ42 of WT and FAD mutations and calculated folding free energies of the Aβ15-27 fragment via umbrella sampling. By studying both the full-length Aβ42 and a fragment containing mutations and the central hydrophobic cluster (residues 17-21), we were able to systematically study how these FAD mutations impact secondary and tertiary structure and the thermodynamics of folding. Electrostatic interactions, including those between permanent and induced dipoles, affected side-chain properties, salt bridges, and solvent interactions. The FAD mutations resulted in shifts in the electronic structure and solvent accessibility at the central hydrophobic cluster and the hydrophobic C-terminal region. Using umbrella sampling, we found that the folding of the WT and E22 mutants is enthalpically driven, whereas the D23N mutant is entropically driven, arising from a different unfolding pathway and peptide-bond dipole response. Together, the unbiased, full-length, and umbrella sampling simulations of fragments reveal that the FAD mutations perturb nearby residues and others in hydrophobic regions to potentially alter solubility. These results highlight the role electronic polarizability plays in amyloid misfolding and the role of heterogeneous microenvironments that arise as conformational change takes place.
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Affiliation(s)
- Darcy S Davidson
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Joshua A Kraus
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Julia M Montgomery
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Justin A Lemkul
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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5
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N-terminally truncated Aβ4-x proteoforms and their relevance for Alzheimer's pathophysiology. Transl Neurodegener 2022; 11:30. [PMID: 35641972 PMCID: PMC9158284 DOI: 10.1186/s40035-022-00303-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 04/21/2022] [Indexed: 01/22/2023] Open
Abstract
Background The molecular heterogeneity of Alzheimer’s amyloid-β (Aβ) deposits extends well beyond the classic Aβ1-40/Aβ1-42 dichotomy, substantially expanded by multiple post-translational modifications that increase the proteome diversity. Numerous truncated fragments consistently populate the brain Aβ peptidome, and their homeostatic regulation and potential contribution to disease pathogenesis are largely unknown. Aβ4-x peptides have been reported as major components of plaque cores and the limited studies available indicate their relative abundance in Alzheimer’s disease (AD). Methods Immunohistochemistry was used to assess the topographic distribution of Aβ4-x species in well-characterized AD cases using custom-generated monoclonal antibody 18H6—specific for Aβ4-x species and blind for full-length Aβ1-40/Aβ1-42—in conjunction with thioflavin-S and antibodies recognizing Aβx-40 and Aβx-42 proteoforms. Circular dichroism, thioflavin-T binding, and electron microscopy evaluated the biophysical and aggregation/oligomerization properties of full-length and truncated synthetic homologues, whereas stereotaxic intracerebral injections of monomeric and oligomeric radiolabeled homologues in wild-type mice were used to evaluate their brain clearance characteristics. Results All types of amyloid deposits contained the probed Aβ epitopes, albeit expressed in different proportions. Aβ4-x species showed preferential localization within thioflavin-S-positive cerebral amyloid angiopathy and cored plaques, strongly suggesting poor clearance characteristics and consistent with the reduced solubility and enhanced oligomerization of their synthetic homologues. In vivo clearance studies demonstrated a fast brain efflux of N-terminally truncated and full-length monomeric forms whereas their oligomeric counterparts—particularly of Aβ4-40 and Aβ4-42—consistently exhibited enhanced brain retention. Conclusions The persistence of aggregation-prone Aβ4-x proteoforms likely contributes to the process of amyloid formation, self-perpetuating the amyloidogenic loop and exacerbating amyloid-mediated pathogenic pathways.
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6
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Zakharova NV, Kononikhin AS, Indeykina MI, Bugrova AE, Strelnikova P, Pekov S, Kozin SA, Popov IA, Mitkevich V, Makarov AA, Nikolaev EN. Mass spectrometric studies of the variety of beta-amyloid proteoforms in Alzheimer's disease. MASS SPECTROMETRY REVIEWS 2022:e21775. [PMID: 35347731 DOI: 10.1002/mas.21775] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/03/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
This review covers the results of the application of mass spectrometric (MS) techniques to study the diversity of beta-amyloid (Aβ) peptides in human samples. Since Aβ is an important hallmark of Alzheimer's disease (AD), which is a socially significant neurodegenerative disorder of the elderly worldwide, analysis of its endogenous variations is of particular importance for elucidating the pathogenesis of AD, predicting increased risks of the disease onset, and developing effective therapy. MS approaches have no alternative for the study of complex samples, including a wide variety of Aβ proteoforms, differing in length and modifications. Approaches based on matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography with electrospray ionization tandem MS are most common in Aβ studies. However, Aβ forms with isomerized and/or racemized Asp and Ser residues require the use of special methods for separation and extra sensitive and selective methods for detection. Overall, this review summarizes current knowledge of Aβ species found in human brain, cerebrospinal fluid, and blood plasma; focuses on application of different MS approaches for Aβ studies; and considers the potential of MS techniques for further studies of Aβ-peptides.
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Affiliation(s)
- Natalia V Zakharova
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Alexey S Kononikhin
- CMCB, Skolkovo Institute of Science and Technology, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Maria I Indeykina
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna E Bugrova
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
- CMCB, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Polina Strelnikova
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
- Laboratory of ion and molecular physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Stanislav Pekov
- CMCB, Skolkovo Institute of Science and Technology, Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Laboratory of ion and molecular physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Sergey A Kozin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Igor A Popov
- Laboratory of ion and molecular physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- N.N. Semenov Federal Center of Chemical Physics, V.L. Talrose Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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7
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Davis J, Xu F, Zhu X, Van Nostrand WE. rTg-D: A novel transgenic rat model of cerebral amyloid angiopathy Type-2. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2022; 3:100133. [PMID: 36324401 PMCID: PMC9616389 DOI: 10.1016/j.cccb.2022.100133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/02/2022] [Accepted: 03/07/2022] [Indexed: 11/11/2022]
Abstract
Background Cerebral amyloid angiopathy (CAA) is common disorder of the elderly, a prominent comorbidity of Alzheimer's disease, and causes vascular cognitive impairment and dementia. Previously, we generated a transgenic rat model of capillary CAA type-1 that develops many pathological features of human disease. However, a complementary rat model of larger vessel CAA type-2 disease has been lacking. Methods A novel transgenic rat model (rTg-D) was generated that produces human familial CAA Dutch E22Q mutant amyloid β-protein (Aβ) in brain and develops larger vessel CAA type-2. Quantitative biochemical and pathological analyses were performed to characterize the progression of CAA and associated pathologies in aging rTg-D rats. Results rTg-D rats begin to accumulate Aβ in brain and develop varying levels of larger vessel CAA type-2, in the absence of capillary CAA type-1, starting around 18 months of age. Larger vessel CAA was mainly composed of the Aβ40 peptide and most prominent in surface leptomeningeal/pial vessels and arterioles of the cortex and thalamus. Cerebral microbleeds and small vessel occlusions were present mostly in the thalamic region of affected rTg-D rats. In contrast to capillary CAA type-1 the amyloid deposited within the walls of larger vessels of rTg-D rats did not promote perivascular astrocyte and microglial responses or accumulate the Aβ chaperone apolipoprotein E. Conclusion Although variable in severity, the rTg-D rats specifically develop larger vessel CAA type-2 that reflects many of the pathological features of human disease and provide a new model to investigate the pathogenesis of this condition.
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Key Words
- AD, Alzheimer's disease
- Amyloid β protein
- ApoE, Apolipoprotein E
- Aβ, Amyloid β-protein
- AβPP, Amyloid β-protein precursor
- CAA, Cerebral amyloid angiopathy
- Cerebral amyloid angiopathy
- Dutch mutation
- GFAP, Glial fibrillary acidic protein
- ICH, Intracerebral hemorrhage
- Iba-1, Ionized calcium-binding adapter molecule 1
- Microbleed
- Small vessel disease
- Transgenic rat
- VCID, Vascular cognitive impairment and dementia
- WT, Wild-type
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Affiliation(s)
- Judianne Davis
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, United States
- Department of Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, United States
| | - Feng Xu
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, United States
- Department of Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, United States
| | - Xiaoyue Zhu
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, United States
- Department of Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, United States
| | - William E. Van Nostrand
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, United States
- Department of Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, United States
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8
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Single Point Mutation from E22-to-K in A β Initiates Early-Onset Alzheimer's Disease by Binding with Catalase. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2020:4981204. [PMID: 33425208 PMCID: PMC7775154 DOI: 10.1155/2020/4981204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 08/31/2020] [Accepted: 12/05/2020] [Indexed: 11/18/2022]
Abstract
Amyloid-beta (Aβ) is a critical etiological factor for late-onset familial Alzheimer's disease (AD). However, an early-onset AD has been found to be related with an Aβ mutation in glutamic acid 22-to-lysine (Italian type E22K). Why only one single point mutation at E22 residue induces AD remains unclear. Here, we report that a Chinese familial AD pedigree with E22K mutation was associated with higher levels of serum hydrogen peroxide (H2O2) and lower activity of catalase (a H2O2 degrading enzyme) than controls. Further, we found that E22K binding with catalase caused more severe H2O2 accumulation in the brains of E22K-injected rats than Aβ-injected rats. Unexpectedly, H2O2 bound with the mutation site 22K residue of E22K and elicited more rapid aggregation of E22K than Aβ in vitro. Moreover, H2O2 acted with E22K synergistically to induce higher cellular toxicity than with Aβ. Notably, intrahippocampal infusion of E22K led to more severe plaque deposition, neuron death, and more rapid memory decline than Aβ-injected rats. However, L-cysteine, a H2O2 scavenger, not only prevented self-aggregation of E22K but also reduced H2O2-promoted E22K assembly in vitro; subsequently, it alleviated Alzheimer-related phenotypes. Hence, E22K binding with catalase promotes the early onset of familial AD, and L-cys may reverse this disease.
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Crooks EJ, Irizarry BA, Ziliox M, Kawakami T, Victor T, Xu F, Hojo H, Chiu K, Simmerling C, Van Nostrand WE, Smith SO, Miller LM. Copper stabilizes antiparallel β-sheet fibrils of the amyloid β40 (Aβ40)-Iowa variant. J Biol Chem 2020; 295:8914-8927. [PMID: 32376688 PMCID: PMC7335782 DOI: 10.1074/jbc.ra119.011955] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 04/25/2020] [Indexed: 01/05/2023] Open
Abstract
Cerebral amyloid angiopathy (CAA) is a vascular disorder that primarily involves deposition of the 40-residue-long β-amyloid peptide (Aβ40) in and along small blood vessels of the brain. CAA is often associated with Alzheimer's disease (AD), which is characterized by amyloid plaques in the brain parenchyma enriched in the Aβ42 peptide. Several recent studies have suggested a structural origin that underlies the differences between the vascular amyloid deposits in CAA and the parenchymal plaques in AD. We previously have found that amyloid fibrils in vascular amyloid contain antiparallel β-sheet, whereas previous studies by other researchers have reported parallel β-sheet in fibrils from parenchymal amyloid. Using X-ray fluorescence microscopy, here we found that copper strongly co-localizes with vascular amyloid in human sporadic CAA and familial Iowa-type CAA brains compared with control brain blood vessels lacking amyloid deposits. We show that binding of Cu(II) ions to antiparallel fibrils can block the conversion of these fibrils to the more stable parallel, in-register conformation and enhances their ability to serve as templates for seeded growth. These results provide an explanation for how thermodynamically less stable antiparallel fibrils may form amyloid in or on cerebral vessels by using Cu(II) as a structural cofactor.
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Affiliation(s)
- Elliot J Crooks
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Brandon A Irizarry
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Martine Ziliox
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Toru Kawakami
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Tiffany Victor
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA
| | - Feng Xu
- George & Anne Ryan Institute for Neuroscience and Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Hironobu Hojo
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | - Kelley Chiu
- Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
| | - Carlos Simmerling
- Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
| | - William E Van Nostrand
- George & Anne Ryan Institute for Neuroscience and Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Steven O Smith
- Department of Biochemistry and Cell Biology, Center for Structural Biology, Stony Brook University, Stony Brook, New York, USA.
| | - Lisa M Miller
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York, USA; Department of Chemistry, Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
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10
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Zampar S, Klafki HW, Sritharen K, Bayer TA, Wiltfang J, Rostagno A, Ghiso J, Miles LA, Wirths O. N-terminal heterogeneity of parenchymal and vascular amyloid-β deposits in Alzheimer's disease. Neuropathol Appl Neurobiol 2020; 46:673-685. [PMID: 32497293 PMCID: PMC8082844 DOI: 10.1111/nan.12637] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/24/2020] [Indexed: 02/06/2023]
Abstract
Aims: The deposition of amyloid-β (Aβ) peptides in the form of extracellular plaques in the brain represents one of the classical hallmarks of Alzheimer’s disease (AD). In addition to ‘full-length’ Aβ starting with aspartic acid (Asp-1), considerable amounts of various shorter, N-terminally truncated Aβ peptides have been identified by mass spectrometry in autopsy samples from individuals with AD. Methods: Selectivity of several antibodies detecting full-length, total or N-terminally truncated Aβ species has been characterized with capillary isoelectric focusing assays using a set of synthetic Aβ peptides comprising different N-termini. We further assessed the N-terminal heterogeneity of extracellular and vascular Aβ peptide deposits in the human brain by performing immunohistochemical analyses using sporadic AD cases with antibodies targeting different N-terminal residues, including the biosimilar antibodies Bapineuzumab and Crenezumab. Results: While antibodies selectively recognizing Aβ1–x showed a much weaker staining of extracellular plaques and tended to accentuate cerebrovascular amyloid deposits, antibodies detecting Aβ starting with phenylalanine at position 4 of the Aβ sequence showed abundant amyloid plaque immunoreactivity in the brain parenchyma. The biosimilar antibody Bapineuzumab recognized Aβ starting at Asp-1 and demonstrated abundant immunoreactivity in AD brains. Discussion: In contrast to other studied Aβ1–x-specific antibodies, Bapineuzumab displayed stronger immunoreactivity on fixed tissue samples than with sodium dodecyl sulfate-denatured samples on Western blots. This suggests conformational preferences of this antibody. The diverse composition of plaques and vascular deposits stresses the importance of understanding the roles of various Aβ variants during disease development and progression in order to generate appropriate target-developed therapies.
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Affiliation(s)
- S Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - H W Klafki
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - K Sritharen
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - T A Bayer
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - J Wiltfang
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany.,Neurosciences and Signaling Group, Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - A Rostagno
- Departments of, Pathology, New York University School of Medicine, New York, NY, USA
| | - J Ghiso
- Departments of, Pathology, New York University School of Medicine, New York, NY, USA.,Department of, Psychiatry, New York University School of Medicine, New York, NY, USA
| | - L A Miles
- St. Vincent's Institute of Medical Research, Fitzroy, VIC, Australia
| | - O Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
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11
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Warmack RA, Boyer DR, Zee CT, Richards LS, Sawaya MR, Cascio D, Gonen T, Eisenberg DS, Clarke SG. Structure of amyloid-β (20-34) with Alzheimer's-associated isomerization at Asp23 reveals a distinct protofilament interface. Nat Commun 2019; 10:3357. [PMID: 31350392 PMCID: PMC6659688 DOI: 10.1038/s41467-019-11183-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/24/2019] [Indexed: 02/07/2023] Open
Abstract
Amyloid-β (Aβ) harbors numerous posttranslational modifications (PTMs) that may affect Alzheimer's disease (AD) pathogenesis. Here we present the 1.1 Å resolution MicroED structure of an Aβ 20-34 fibril with and without the disease-associated PTM, L-isoaspartate, at position 23 (L-isoAsp23). Both wild-type and L-isoAsp23 protofilaments adopt β-helix-like folds with tightly packed cores, resembling the cores of full-length fibrillar Aβ structures, and both self-associate through two distinct interfaces. One of these is a unique Aβ interface strengthened by the isoaspartyl modification. Powder diffraction patterns suggest a similar structure may be adopted by protofilaments of an analogous segment containing the heritable Iowa mutation, Asp23Asn. Consistent with its early onset phenotype in patients, Asp23Asn accelerates aggregation of Aβ 20-34, as does the L-isoAsp23 modification. These structures suggest that the enhanced amyloidogenicity of the modified Aβ segments may also reduce the concentration required to achieve nucleation and therefore help spur the pathogenesis of AD.
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Affiliation(s)
- Rebeccah A Warmack
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - David R Boyer
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Chih-Te Zee
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Logan S Richards
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA
| | - Michael R Sawaya
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA
| | - Duilio Cascio
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA
| | - Tamir Gonen
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1737, USA.,Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095-1751, USA
| | - David S Eisenberg
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,UCLA-DOE Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.,Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1737, USA
| | - Steven G Clarke
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095-1569, USA. .,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095-1570, USA.
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12
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Mudedla SK, Murugan NA, Ågren H. Effect of Familial Mutations on the Interconversion of α-Helix to β-Sheet Structures in an Amyloid-Forming Peptide: Insight from Umbrella Sampling Simulations. ACS Chem Neurosci 2019; 10:1347-1354. [PMID: 30586502 DOI: 10.1021/acschemneuro.8b00425] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Understanding the initial events of aggregation of amyloid β monomers to form β-sheet rich fibrils is useful for the development of therapeutics for Alzheimer's disease. In this context, the changes in energetics involved in the aggregation of helical amyloid β monomers into β-sheet rich dimers have been investigated using umbrella sampling simulations and density functional theory calculations. The results from umbrella sampling simulations for the free energy profile for the interconversion closely agree with the results of density functional theory calculations. The results reveal that helical peptides converted to β-sheet structures through coil-like conformations as intermediates that are mostly stabilized by intramolecular hydrogen bonds. The stabilization of intermediate structures could be a possible way to inhibit fibril formation. Mutations substantially decrease the height of the energy barrier for interconversion from α-helix to β-sheet structure when compared to that of the wild type, something that is attributed to an increase in the number of intramolecular hydrogen bonds between backbone atoms in the coil structures that correspond to a maximum value on the free energy surface. The reduction of the energy barrier leads to an enhancement of the rate of aggregation of amyloid β monomers upon introduction of various familial mutations, which is consistent with previous experimental reports.
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Affiliation(s)
- Sathish Kumar Mudedla
- Division of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
| | - N. Arul Murugan
- Division of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
| | - Hans Ågren
- Division of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, AlbaNova University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
- College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
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13
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Sadakane Y, Kawahara M. Implications of Metal Binding and Asparagine Deamidation for Amyloid Formation. Int J Mol Sci 2018; 19:ijms19082449. [PMID: 30126231 PMCID: PMC6121660 DOI: 10.3390/ijms19082449] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/10/2018] [Accepted: 08/14/2018] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence suggests that amyloid formation, i.e., self-assembly of proteins and the resulting conformational changes, is linked with the pathogenesis of various neurodegenerative disorders such as Alzheimer’s disease, prion diseases, and Lewy body diseases. Among the factors that accelerate or inhibit oligomerization, we focus here on two non-genetic and common characteristics of many amyloidogenic proteins: metal binding and asparagine deamidation. Both reflect the aging process and occur in most amyloidogenic proteins. All of the amyloidogenic proteins, such as Alzheimer’s β-amyloid protein, prion protein, and α-synuclein, are metal-binding proteins and are involved in the regulation of metal homeostasis. It is widely accepted that these proteins are susceptible to non-enzymatic posttranslational modifications, and many asparagine residues of these proteins are deamidated. Moreover, these two factors can combine because asparagine residues can bind metals. We review the current understanding of these two common properties and their implications in the pathogenesis of these neurodegenerative diseases.
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Affiliation(s)
- Yutaka Sadakane
- Graduate School of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka 513-8670, Japan.
| | - Masahiro Kawahara
- Department of Bio-Analytical Chemistry, Faculty of Pharmacy, Musashino University, 1-1-20 Shinmachi, Nishitokyo, Tokyo 202-8585, Japan.
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14
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Rosenman DJ, Clemente N, Ali M, García AE, Wang C. High pressure NMR reveals conformational perturbations by disease-causing mutations in amyloid β-peptide. Chem Commun (Camb) 2018; 54:4609-4612. [PMID: 29670961 DOI: 10.1039/c8cc01674g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we present the high pressure NMR characterization of Aβ42 and two Aβ40 variants with Alzheimer-causing mutations E22G and D23N. While chemical shifts only identified localized changes at ambient pressure compared with Aβ40, high pressure NMR revealed a common site with heightened pressure sensitivity at Q15, K16 and L17 in all three variants, which correlates to higher β-propensity at central hydrophobic cluster (CHC) and faster aggregation.
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Affiliation(s)
- David J Rosenman
- Department of Biological Sciences, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, USA.
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15
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Abstract
The fundamental pathology in Alzheimer's disease (AD) is neuronal dysfunction leading to cognitive impairment. The amyloid-β peptide (Aβ), derived from amyloid precursor protein, is one driver of AD, but how it leads to neuronal dysfunction is not established. In this Review, I discuss the complexity of AD and possible cause-and-effect relationships between Aβ and the vascular and hemostatic systems. AD can be considered a multifactorial syndrome with various contributing pathological mechanisms. Therefore, as is routinely done with cancer, it will be important to classify patients with respect to their disease signature so that specific pathologies, including vascular pathways, can be therapeutically targeted.
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16
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Abstract
Amyloid β (Aβ) is the major constituent of the brain deposits found in parenchymal plaques and cerebral blood vessels of patients with Alzheimer's disease (AD). Besides classic full-length peptides, biochemical analyses of brain deposits have revealed high degree of Aβ heterogeneity likely resulting from the action of multiple proteolytic enzymes. This chapter describes a sequential extraction protocol allowing the differential fractionation of soluble and deposited Aβ species taking advantage of their differential solubility properties. Soluble Aβ is extracted by water-based buffers like phosphate-buffered saline-PBS-whereas pre-fibrillar and fibrillar deposits, usually poorly soluble in PBS, are extractable in detergent containing solutions or more stringent conditions as formic acid. The extraction procedure is followed by the biochemical identification of the extracted Aβ species using Western blot and a targeted proteomic analysis which combines immunoprecipitation with MALDI-ToF mass spectrometry. This approach revealed the presence of numerous C- and N-terminal truncated Aβ species in addition to Aβ1-40/42. Notably, the more soluble C-terminal cleaved fragments constitute a main part of PBS homogenates. On the contrary, N-terminal truncated species typically require more stringent conditions for the extraction in agreement with their lower solubility and enhanced aggregability. Detailed assessment of the molecular diversity of Aβ species composing interstitial fluid and amyloid deposits at different disease stages, as well as the evaluation of the truncation profile during various pharmacologic approaches will provide a comprehensive understanding of the still undefined contribution of Aβ truncations to AD pathogenesis and their potential as novel therapeutic targets.
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Affiliation(s)
- Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Thomas A Neubert
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY, USA
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY, USA.
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA.
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17
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Balamurugan K, Murugan NA, Långström B, Nordberg A, Ågren H. Effect of Alzheimer Familial Chromosomal Mutations on the Amyloid Fibril Interaction with Different PET Tracers: Insight from Molecular Modeling Studies. ACS Chem Neurosci 2017; 8:2655-2666. [PMID: 28898051 DOI: 10.1021/acschemneuro.7b00215] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder. Along with an increasing number of elderly worldwide, it poses a great challenge for the society and health care. Although sporadic AD is the common form of AD, 2-3% of the AD cases are expected to be due to mutations in the β region of the amyloid precursor protein, which is referred to as autosomal dominant AD (ADAD). These mutations may cause changes in the secondary structure of the amyloid β fibrils and may alter the fibrillization rate leading to changes in the disease development and could also affect the binding to tracers used in diagnosis. In particular, from some recent clinical studies using PET tracers for detection of fibrillar amyloids, it is evident that in ADAD patients with Arctic mutation no amyloid plaque binding can be detected with the 11C-Pittsburgh Compound B (11C-PIB). However, for in vitro conditions, significant binding of 3H-PIB has been reported for the amyloid fibrils carrying the Arctic mutation. The aim of the present study is to investigate if there is any mutation specific binding of commonly used amyloid tracers, namely, florbetaben, florbetapir, FPIB, AZD4694, and AZD2184, by means of molecular modeling techniques. Other than Arctic, ADAD mutations, such as the Dutch, Italian, Iowa, and Flemish mutations, are considered in this study. We report that all tracers except florbetapir show reduced binding affinity toward amyloid β fibrils with the Arctic mutation when compared to the native type. Moreover, florbetapir is the only tracer that binds to all mutants with increased affinity when compared to the native fibril. The results obtained from these studies could increase the understanding of the structural changes caused by mutation and concomitant changes in the interaction pattern of the PET tracers with the mutated variants, which in turn can be useful in selecting the appropriate tracers for the purpose of diagnosis as well as for designing new tracers with desirable properties.
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Affiliation(s)
- Kanagasabai Balamurugan
- Division
of Theoretical Chemistry and Biology, School of Biotechnology, AlbaNova
University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
| | - Natarajan Arul Murugan
- Division
of Theoretical Chemistry and Biology, School of Biotechnology, AlbaNova
University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
| | - Bengt Långström
- Department
of Chemistry, Uppsala University, 751 23 Uppsala, Sweden
| | - Agneta Nordberg
- Department
of Neurobiology, Care Sciences and Society, Center for Alzheimer Research,
Translational Alzheimer Neurobiology, Department of Geriatric Medicine,
Karolinska University Hospital, Karolinska Institute, Huddinge, 141
86 Stockholm, Sweden
| | - Hans Ågren
- Division
of Theoretical Chemistry and Biology, School of Biotechnology, AlbaNova
University Center, Royal Institute of Technology (KTH), S-106 91 Stockholm, Sweden
- Institute
of Nanotechnology, Spectroscopy and Quantum Chemistry, Siberian Federal University, Svobodny pr. 79, 660041 Krasnoyarsk, Russia
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18
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Roher AE, Kokjohn TA, Clarke SG, Sierks MR, Maarouf CL, Serrano GE, Sabbagh MS, Beach TG. APP/Aβ structural diversity and Alzheimer's disease pathogenesis. Neurochem Int 2017; 110:1-13. [PMID: 28811267 PMCID: PMC5688956 DOI: 10.1016/j.neuint.2017.08.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/25/2017] [Accepted: 08/11/2017] [Indexed: 02/01/2023]
Abstract
The amyloid cascade hypothesis of Alzheimer's disease (AD) proposes amyloid- β (Aβ) is a chief pathological element of dementia. AD therapies have targeted monomeric and oligomeric Aβ 1-40 and 1-42 peptides. However, alternative APP proteolytic processing produces a complex roster of Aβ species. In addition, Aβ peptides are subject to extensive posttranslational modification (PTM). We propose that amplified production of some APP/Aβ species, perhaps exacerbated by differential gene expression and reduced peptide degradation, creates a diverse spectrum of modified species which disrupt brain homeostasis and accelerate AD neurodegeneration. We surveyed the literature to catalog Aβ PTM including species with isoAsp at positions 7 and 23 which may phenocopy the Tottori and Iowa Aβ mutations that result in early onset AD. We speculate that accumulation of these alterations induce changes in secondary and tertiary structure of Aβ that favor increased toxicity, and seeding and propagation in sporadic AD. Additionally, amyloid-β peptides with a pyroglutamate modification at position 3 and oxidation of Met35 make up a substantial portion of sporadic AD amyloid deposits. The intrinsic physical properties of these species, including resistance to degradation, an enhanced aggregation rate, increased neurotoxicity, and association with behavioral deficits, suggest their emergence is linked to dementia. The generation of specific 3D-molecular conformations of Aβ impart unique biophysical properties and a capacity to seed the prion-like global transmission of amyloid through the brain. The accumulation of rogue Aβ ultimately contributes to the destruction of vascular walls, neurons and glial cells culminating in dementia. A systematic examination of Aβ PTM and the analysis of the toxicity that they induced may help create essential biomarkers to more precisely stage AD pathology, design countermeasures and gauge the impacts of interventions.
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Affiliation(s)
- Alex E Roher
- Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ 85013, USA; Division of Clinical Education, Midwestern University, Glendale, AZ 85308, USA.
| | - Tyler A Kokjohn
- Department of Microbiology, Midwestern University, Glendale, AZ 85308, USA
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles CA 90095-1569, USA
| | - Michael R Sierks
- Department of Chemical Engineering, Arizona State University, Tempe, AZ 85287-6106, USA
| | - Chera L Maarouf
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Geidy E Serrano
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Marwan S Sabbagh
- Alzheimer's and Memory Disorders Division, Barrow Neurological Institute, Phoenix, AZ 85013, USA
| | - Thomas G Beach
- Laboratory of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ 85351, USA
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19
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Aβ truncated species: Implications for brain clearance mechanisms and amyloid plaque deposition. Biochim Biophys Acta Mol Basis Dis 2017; 1864:208-225. [PMID: 28711595 DOI: 10.1016/j.bbadis.2017.07.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/24/2017] [Accepted: 07/11/2017] [Indexed: 12/14/2022]
Abstract
Extensive parenchymal and vascular Aβ deposits are pathological hallmarks of Alzheimer's disease (AD). Besides classic full-length peptides, biochemical analyses of brain deposits have revealed high degree of Aβ heterogeneity likely resulting from the action of multiple proteolytic enzymes. In spite of the numerous studies focusing in Aβ, the relevance of N- and C-terminal truncated species for AD pathogenesis remains largely understudied. In the present work, using novel antibodies specifically recognizing Aβ species N-terminally truncated at position 4 or C-terminally truncated at position 34, we provide a clear assessment of the differential topographic localization of these species in AD brains and transgenic models. Based on their distinct solubility, brain N- and C-terminal truncated species were extracted by differential fractionation and identified via immunoprecipitation coupled to mass spectrometry analysis. Biochemical/biophysical studies with synthetic homologues further confirmed the different solubility properties and contrasting fibrillogenic characteristics of the truncated species composing the brain Aβ peptidome. Aβ C-terminal degradation leads to the production of more soluble fragments likely to be more easily eliminated from the brain. On the contrary, N-terminal truncation at position 4 favors the formation of poorly soluble, aggregation prone peptides with high amyloidogenic propensity and the potential to exacerbate the fibrillar deposits, self-perpetuating the amyloidogenic loop. Detailed assessment of the molecular diversity of Aβ species composing interstitial fluid and amyloid deposits at different disease stages, as well as the evaluation of the truncation profile during various pharmacologic approaches will provide a comprehensive understanding of the still undefined contribution of Aβ truncations to the disease pathogenesis and their potential as novel therapeutic targets.
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20
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McIntee FL, Giannoni P, Blais S, Sommer G, Neubert TA, Rostagno A, Ghiso J. In vivo Differential Brain Clearance and Catabolism of Monomeric and Oligomeric Alzheimer's Aβ protein. Front Aging Neurosci 2016; 8:223. [PMID: 27729857 PMCID: PMC5037193 DOI: 10.3389/fnagi.2016.00223] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/07/2016] [Indexed: 01/06/2023] Open
Abstract
Amyloid β (Aβ) is the major constituent of the brain deposits found in parenchymal plaques and cerebral blood vessels of patients with Alzheimer's disease (AD). Several lines of investigation support the notion that synaptic pathology, one of the strongest correlates to cognitive impairment, is related to the progressive accumulation of neurotoxic Aβ oligomers. Since the process of oligomerization/fibrillization is concentration-dependent, it is highly reliant on the homeostatic mechanisms that regulate the steady state levels of Aβ influencing the delicate balance between rate of synthesis, dynamics of aggregation, and clearance kinetics. Emerging new data suggest that reduced Aβ clearance, particularly in the aging brain, plays a critical role in the process of amyloid formation and AD pathogenesis. Using well-defined monomeric and low molecular mass oligomeric Aβ1-40 species stereotaxically injected into the brain of C57BL/6 wild-type mice in combination with biochemical and mass spectrometric analyses in CSF, our data clearly demonstrate that Aβ physiologic removal is extremely fast and involves local proteolytic degradation leading to the generation of heterogeneous C-terminally cleaved proteolytic products, while providing clear indication of the detrimental role of oligomerization for brain Aβ efflux. Immunofluorescence confocal microscopy studies provide insight into the cellular pathways involved in the brain removal and cellular uptake of Aβ. The findings indicate that clearance from brain interstitial fluid follows local and systemic paths and that in addition to the blood-brain barrier, local enzymatic degradation and the bulk flow transport through the choroid plexus into the CSF play significant roles. Our studies highlight the diverse factors influencing brain clearance and the participation of various routes of elimination opening up new research opportunities for the understanding of altered mechanisms triggering AD pathology and for the potential design of combined therapeutic strategies.
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Affiliation(s)
- Farron L McIntee
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Patrizia Giannoni
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Steven Blais
- Department of Biochemistry and Molecular Pharmacology, New York University School of MedicineNew York, NY, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of MedicineNew York, NY, USA
| | - George Sommer
- Radiation Safety Office, New York University School of Medicine New York, NY, USA
| | - Thomas A Neubert
- Department of Biochemistry and Molecular Pharmacology, New York University School of MedicineNew York, NY, USA; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of MedicineNew York, NY, USA
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine New York, NY, USA
| | - Jorge Ghiso
- Department of Pathology, New York University School of MedicineNew York, NY, USA; Department of Psychiatry, New York University School of MedicineNew York, NY, USA
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21
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Panahi A, Bandara A, Pantelopulos GA, Dominguez L, Straub JE. Specific Binding of Cholesterol to C99 Domain of Amyloid Precursor Protein Depends Critically on Charge State of Protein. J Phys Chem Lett 2016; 7:3535-41. [PMID: 27525349 PMCID: PMC5293176 DOI: 10.1021/acs.jpclett.6b01624] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Recent NMR chemical shift measurements of the 99 residue C-terminal fragment of amyloid precursor protein (APP-C99) in the presence of cholesterol provide evidence of binary complex formation between C99 and cholesterol in membrane mimetic environments. It has also been observed that the production of Aβ protein is enhanced under conditions of high cholesterol concentration. In this study, we investigated the impact of the charge state of C99 on the structure and stability of the C99-cholesterol complex. We observed that the binding of C99 to cholesterol depends critically on the charge state of Glu 693 (E22) and Asp 694 (D23). Evaluation of the pKa values of the Asp and Glu side chains suggests that these residues may be predominantly neutral in existing experimental observations of a stable C99-cholesterol complex at lower pH (characteristic of the endosomal environment), while binding is destabilized near neutral pH (characteristic of the cytoplasm). These observations suggest that specific binding of cholesterol to C99 is a sensitive function of the pH encountered in vivo, with key E22 and D23 residues serving as a "pH switch" controlling C99-cholesterol binding.
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Affiliation(s)
- Afra Panahi
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts, 02215
| | - Asanga Bandara
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts, 02215
| | - George A. Pantelopulos
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts, 02215
| | - Laura Dominguez
- Biophysical Chemistry Laboratory, Physical Chemistry Department, School of Chemistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - John E. Straub
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts, 02215
- Corresponding Author:
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22
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Rosenman DJ, Wang C, García AE. Characterization of Aβ Monomers through the Convergence of Ensemble Properties among Simulations with Multiple Force Fields. J Phys Chem B 2015; 120:259-77. [PMID: 26562747 DOI: 10.1021/acs.jpcb.5b09379] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloid β (Aβ) monomers represent a base state in the pathways of aggregation that result in the fibrils and oligomers implicated in the pathogenesis of Alzheimer's disease (AD). The structural properties of these intrinsically disordered peptides remain unclear despite extensive experimental and computational investigations. Further, there are mutations within Aβ that change the way the peptide aggregates and are known to cause familial AD (FAD). Here, we analyze the ensembles of different isoforms (Aβ42 and Aβ40) and mutants (E22Δ, D23N, E22K, E22G, and A2T in Aβ40) of Aβ generated with all-atom replica exchange molecular dynamics (REMD) simulations on the μs/replica time scale. These were run using three different force field/water model combinations: OPLS-AA/L and TIP3P ("OPLS"), AMBER99sb-ILDN and TIP4P-Ew ("ILDN"), as well as CHARMM22* and TIP3SP ("CHARMM"). Despite fundamental changes in simulation parameters, we find that the resulting ensembles demonstrate a strong convergence in structural properties. In particular, antiparallel contacts between L17-A21 and A30-L34 are prevalent in ensembles of Aβ40, directly forming β sheets in the OPLS and ILDN combinations. A21-A30 commonly forms an interceding region that rarely interacts with the rest of the peptide. Further, Aβ42 contributes new β hairpin motifs involving V40-I41 in both OPLS and ILDN. However, the structural flexibility of the central region and the electrostatic interactions that characterize it are notably different between the different conditions. Further, for OPLS, each of the FAD mutations disrupts central bend character and increases the polymorphism of antiparallel contacts across the central region. However, the studied mutations in the ILDN set primarily encourage more global contacts involving the N-terminus and the central region, and promote the formation of new β topologies that may seed different aggregates involved in disease phenotypes. These differences aside, the large degree of agreement between simulation sets across multiple force fields provides a generalizable characterization of Aβ that is also consistent with experimental data and models.
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Affiliation(s)
- David J Rosenman
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States
| | - Chunyu Wang
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Graduate Program in Biochemistry and Biophysics, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States
| | - Angel E García
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Non Linear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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23
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Van Nostrand WE. The influence of the amyloid ß-protein and its precursor in modulating cerebral hemostasis. Biochim Biophys Acta Mol Basis Dis 2015; 1862:1018-26. [PMID: 26519139 DOI: 10.1016/j.bbadis.2015.10.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 02/07/2023]
Abstract
Ischemic and hemorrhagic strokes are a significant cause of brain injury leading to vascular cognitive impairment and dementia (VCID). These deleterious events largely result from disruption of cerebral hemostasis, a well-controlled and delicate balance between thrombotic and fibrinolytic pathways in cerebral blood vessels and surrounding brain tissue. Ischemia and hemorrhage are both commonly associated with cerebrovascular deposition of amyloid ß-protein (Aß). In this regard, Aß directly and indirectly modulates cerebral thrombosis and fibrinolysis. Further, major isoforms of the Aß precursor protein (AßPP) function as a potent inhibitor of pro-thrombotic proteinases. The purpose of this review article is to summarize recent research on how cerebral vascular Aß and AßPP influence cerebral hemostasis. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia, edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.
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Affiliation(s)
- William E Van Nostrand
- Department of Neurosurgery, HSC-T12/086, Stony Brook University, Stony Brook, NY 11794-8122, USA; Department of Medicine, HSC-T12/086, Stony Brook University, Stony Brook, NY 11794-8122, USA.
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Iwanowski P, Kozubski W, Losy J. Iowa-type hereditary cerebral amyloid angiopathy in a Polish family. J Neurol Sci 2015; 356:202-4. [DOI: 10.1016/j.jns.2015.06.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 11/28/2022]
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25
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Affiliation(s)
- Manish K. Tiwari
- DTU Chemistry Technical University of Denmark Kongens Lyngby Denmark
| | - Kasper P. Kepp
- DTU Chemistry Technical University of Denmark Kongens Lyngby Denmark
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Hernandez-Guillamon M, Mawhirt S, Blais S, Montaner J, Neubert TA, Rostagno A, Ghiso J. Sequential Amyloid-β Degradation by the Matrix Metalloproteases MMP-2 and MMP-9. J Biol Chem 2015; 290:15078-91. [PMID: 25897080 DOI: 10.1074/jbc.m114.610931] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Indexed: 01/11/2023] Open
Abstract
Matrix metalloproteases (MMPs) MMP-2 and MMP-9 have been implicated in the physiological catabolism of Alzheimer's amyloid-β (Aβ). Conversely, their association with vascular amyloid deposits, blood-brain barrier disruption, and hemorrhagic transformations after ischemic stroke also highlights their involvement in pathological processes. To better understand this dichotomy, recombinant human (rh) MMP-2 and MMP-9 were incubated with Aβ40 and Aβ42, and the resulting proteolytic fragments were assessed via immunoprecipitation and quantitative mass spectrometry. Both MMPs generated Aβ fragments truncated only at the C terminus, ending at positions 34, 30, and 16. Using deuterated homologues as internal standards, we observed limited and relatively slow degradation of Aβ42 by rhMMP-2, although the enzyme cleaved >80% of Aβ40 during the 1st h of incubation. rhMMP-9 was significantly less effective, particularly in degrading Aβ(1-42), although the targeted peptide bonds were identical. Using Aβ(1-34) and Aβ(1-30), we demonstrated that these peptides are also substrates for both MMPs, cleaving Aβ(1-34) to produce Aβ(1-30) first and Aβ(1-16) subsequently. Consistent with the kinetics observed with full-length Aβ, rhMMP-9 degraded only a minute fraction of Aβ(1-34) and was even less effective in producing Aβ(1-16). Further degradation of Aβ(1-16) by either MMP-2 or MMP-9 was not observed even after prolonged incubation times. Notably, all MMP-generated C-terminally truncated Aβ fragments were highly soluble and did not exhibit fibrillogenic properties or induce cytotoxicity in human cerebral microvascular endothelial or neuronal cells supporting the notion that these truncated Aβ species are associated with clearance mechanisms rather than being key elements in the fibrillogenesis process.
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Affiliation(s)
- Mar Hernandez-Guillamon
- From the Departments of Pathology, the Neurovascular Research Laboratory, Institut de Recerca, 08035 Barcelona, Spain
| | | | - Steven Blais
- Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, the Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016, and
| | - Joan Montaner
- the Neurovascular Research Laboratory, Institut de Recerca, 08035 Barcelona, Spain, the Neurovascular Unit, Neurology and Medicine Departments, Universitat Autònoma de Barcelona, Vall d'Hebron Hospital, 08035 Barcelona, Spain
| | - Thomas A Neubert
- Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, the Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016, and
| | | | - Jorge Ghiso
- From the Departments of Pathology, Psychiatry, and
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Differential contribution of isoaspartate post-translational modifications to the fibrillization and toxic properties of amyloid β and the Asn23 Iowa mutation. Biochem J 2015; 456:347-60. [PMID: 24028142 DOI: 10.1042/bj20130652] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mutations within the Aβ (amyloid β) peptide, especially those clustered at residues 21-23, are linked to early-onset AD (Alzheimer's disease) and primarily associated with cerebral amyloid angiopathy. The Iowa variant, a substitution of an aspartic acid residue for asparagine at position 23 (D23N), associates with widespread vascular amyloid and abundant diffuse pre-amyloid lesions significantly exceeding the incidence of mature plaques. Brain Iowa deposits consist primarily of a mixture of mutated and non-mutated Aβ species exhibiting partial aspartate isomerization at positions 1, 7 and 23. The present study analysed the contribution of the post-translational modification and the D23N mutation to the aggregation/fibrillization and cell toxicity properties of Aβ providing insight into the elicited cell death mechanisms. The induction of apoptosis by the different Aβ species correlated with their oligomerization/fibrillization propensity and β-sheet content. Although cell toxicity was primarily driven by the D23N mutation, all Aβ isoforms tested were capable, albeit at different time frames, of eliciting comparable apoptotic pathways with mitochondrial engagement and cytochrome c release to the cytoplasm in both neuronal and microvascular endothelial cells. Methazolamide, a cytochrome c release inhibitor, exerted a protective effect in both cell types, suggesting that pharmacological targeting of mitochondria may constitute a viable therapeutic avenue.
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Tiwari MK, Kepp KP. Pathogenic properties of Alzheimer's β-amyloid identified from structure–property patient-phenotype correlations. Dalton Trans 2015; 44:2747-54. [DOI: 10.1039/c4dt03122a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct correlation of Alzheimer patient data to a spectrum of NMR structures and chemical properties of beta amyloid (Aβ) variants allows identification of conformation-dependent disease properties.
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Affiliation(s)
- Manish K. Tiwari
- Department of Chemistry
- Technical University of Denmark
- Kongens Lyngby 2800
- Denmark
| | - Kasper P. Kepp
- Department of Chemistry
- Technical University of Denmark
- Kongens Lyngby 2800
- Denmark
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Ghiso J, Fossati S, Rostagno A. Amyloidosis associated with cerebral amyloid angiopathy: cell signaling pathways elicited in cerebral endothelial cells. J Alzheimers Dis 2014; 42 Suppl 3:S167-76. [PMID: 24670400 PMCID: PMC4467213 DOI: 10.3233/jad-140027] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Substantial genetic, biochemical, and in vivo data indicate that progressive accumulation of amyloid-β (Aβ) plays a central role in the pathogenesis of Alzheimer's disease (AD). Historically centered in the importance of parenchymal plaques, the role of cerebral amyloid angiopathy (CAA)--a frequently neglected amyloid deposit present in >80% of AD cases--for the mechanism of disease pathogenesis is now starting to emerge. CAA consistently associates with microvascular modifications, ischemic lesions, micro- and macro-hemorrhages, and dementia, progressively affecting cerebral blood flow, altering blood-brain barrier permeability, interfering with brain clearance mechanisms and triggering a cascade of deleterious pro-inflammatory and metabolic events that compromise the integrity of the neurovascular unit. New evidence highlights the contribution of pre-fibrillar Aβ in the induction of cerebral endothelial cell dysfunction. The recently discovered interaction of oligomeric Aβ species with TRAIL DR4 and DR5 cell surface death receptors mediates the engagement of mitochondrial pathways and sequential activation of multiple caspases, eliciting a cascade of cell death mechanisms while unveiling an opportunity for exploring mechanistic-based therapeutic interventions to preserve the integrity of the neurovascular unit.
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Affiliation(s)
- Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY, USA Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Silvia Fossati
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, NY, USA
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Kalimo H, Lalowski M, Bogdanovic N, Philipson O, Bird TD, Nochlin D, Schellenberg GD, Brundin R, Olofsson T, Soliymani R, Baumann M, Wirths O, Bayer TA, Nilsson LNG, Basun H, Lannfelt L, Ingelsson M. The Arctic AβPP mutation leads to Alzheimer's disease pathology with highly variable topographic deposition of differentially truncated Aβ. Acta Neuropathol Commun 2013; 1:60. [PMID: 24252272 PMCID: PMC4226306 DOI: 10.1186/2051-5960-1-60] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 08/05/2013] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND The Arctic mutation (p.E693G/p.E22G)fs within the β-amyloid (Aβ) region of the β-amyloid precursor protein gene causes an autosomal dominant disease with clinical picture of typical Alzheimer's disease. Here we report the special character of Arctic AD neuropathology in four deceased patients. RESULTS Aβ deposition in the brains was wide-spread (Thal phase 5) and profuse. Virtually all parenchymal deposits were composed of non-fibrillar, Congo red negative Aβ aggregates. Congo red only stained angiopathic vessels. Mass spectrometric analyses showed that Aβ deposits contained variably truncated and modified wild type and mutated Aβ species. In three of four Arctic AD brains, most cerebral cortical plaques appeared targetoid with centres containing C-terminally (beyond aa 40) and variably N-terminally truncated Aβ surrounded by coronas immunopositive for Aβx-42. In the fourth patient plaque centres contained almost no Aβ making the plaques ring-shaped. The architectural pattern of plaques also varied between different anatomic regions. Tau pathology corresponded to Braak stage VI, and appeared mainly as delicate neuropil threads (NT) enriched within Aβ plaques. Dystrophic neurites were scarce, while neurofibrillary tangles were relatively common. Neuronal perikarya within the Aβ plaques appeared relatively intact. CONCLUSIONS In Arctic AD brain differentially truncated abundant Aβ is deposited in plaques of variable numbers and shapes in different regions of the brain (including exceptional targetoid plaques in neocortex). The extracellular non-fibrillar Aβ does not seem to cause overt damage to adjacent neurons or to induce formation of neurofibrillary tangles, supporting the view that intracellular Aβ oligomers are more neurotoxic than extracellular Aβ deposits. However, the enrichment of NTs within plaques suggests some degree of intra-plaque axonal damage including accumulation of hp-tau, which may impair axoplasmic transport, and thereby contribute to synaptic loss. Finally, similarly as the cotton wool plaques in AD resulting from exon 9 deletion in the presenilin-1 gene, the Arctic plaques induced only modest glial and inflammatory tissue reaction.
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31
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APP mutations in the Aβ coding region are associated with abundant cerebral deposition of Aβ38. Acta Neuropathol 2012; 124:809-21. [PMID: 23143229 DOI: 10.1007/s00401-012-1061-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 12/19/2022]
Abstract
Aβ is the main component of amyloid deposits in Alzheimer disease (AD) and its aggregation into oligomers, protofibrils and fibrils is considered a seminal event in the pathogenesis of AD. Aβ with C-terminus at residue 42 is the most abundant species in parenchymal deposits, whereas Aβ with C-terminus at residue 40 predominates in the amyloid of the walls of large vessels. Aβ peptides with other C-termini have not yet been thoroughly investigated. We analysed Aβ38 in the brains of patients with Aβ deposition linked to sporadic and familial AD, hereditary cerebral haemorrhage with amyloidosis, or Down syndrome. Immunohistochemistry, confocal microscopy, immunoelectron microscopy, immunoprecipitation and the electrophoresis separation of low molecular weight aggregates revealed that Aβ38 accumulates consistently in the brains of patients carrying APP mutations in the Aβ coding region, but was not detected in the patients with APP mutations outside the Aβ domain, in the patients with presenilin mutations or in subjects with Down syndrome. In the patients with sporadic AD, Aβ38 was absent in the senile plaques, but it was detected only in the vessel walls of a small subset of patients with severe cerebral amyloid angiopathy. Our results suggest that APP mutations in the Aβ coding region favour Aβ38 accumulation in the brain and that the molecular mechanisms of Aβ deposition in these patients may be different from those active in patients with familial AD associated with other genetic defects and sporadic AD.
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32
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Cruz L, Rao JS, Teplow DB, Urbanc B. Dynamics of metastable β-hairpin structures in the folding nucleus of amyloid β-protein. J Phys Chem B 2012; 116:6311-25. [PMID: 22587454 PMCID: PMC3394227 DOI: 10.1021/jp301619v] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The amyloid β-protein (Aβ), which is present predominately as a 40- or 42-residue peptide, is postulated to play a seminal role in the pathogenesis of Alzheimer's disease (AD). Folding of the Aβ(21-30) decapeptide region is a critical step in the aggregation of Aβ. We report results of constant temperature all-atom molecular dynamics simulations in explicit water of the dynamics of monomeric Aβ(21-30) and its Dutch [Glu22Gln], Arctic [Glu22Gly], and Iowa [Asp23Asn] isoforms that are associated with familial forms of cerebral amyloid angiopathy and AD. The simulations revealed a variety of loop conformers that exhibited a hydrogen bond network involving the Asp23 and Ser26 amino acids. A population of conformers, not part of the loop population, was found to form metastable β-hairpin structures with the highest probability in the Iowa mutant. At least three β-hairpin structures were found that differed in their hydrogen bonding register, average number of backbone hydrogen bonds, and lifetimes. Analysis revealed that the Dutch mutant had the longest β-hairpin lifetime (≥500 ns), closely followed by the Iowa mutant (≈500 ns). Aβ(21-30) and the Arctic mutant had significantly lower lifetimes (≈200 ns). Hydrophobic packing of side chains was responsible for enhanced β-hairpin lifetimes in the Dutch and Iowa mutants, whereas lifetimes in Aβ(21-30) and its Arctic mutant were influenced by the backbone hydrogen bonding. The data suggest that prolonged β-hairpin lifetimes may impact peptide pathogenicity in vivo.
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Affiliation(s)
- L Cruz
- Department of Physics, 3141 Chestnut Street, Drexel University, Philadelphia, Pennsylvania 19104, United States.
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33
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Masters CL, Selkoe DJ. Biochemistry of amyloid β-protein and amyloid deposits in Alzheimer disease. Cold Spring Harb Perspect Med 2012; 2:a006262. [PMID: 22675658 PMCID: PMC3367542 DOI: 10.1101/cshperspect.a006262] [Citation(s) in RCA: 395] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Progressive cerebral deposition of the amyloid β-protein (Aβ) in brain regions serving memory and cognition is an invariant and defining feature of Alzheimer disease. A highly similar but less robust process accompanies brain aging in many nondemented humans, lower primates, and some other mammals. The discovery of Aβ as the subunit of the amyloid fibrils in meningocerebral blood vessels and parenchymal plaques has led to innumerable studies of its biochemistry and potential cytotoxic properties. Here we will review the discovery of Aβ, numerous aspects of its complex biochemistry, and current attempts to understand how a range of Aβ assemblies, including soluble oligomers and insoluble fibrils, may precipitate and promote neuronal and glial alterations that underlie the development of dementia. Although the role of Aβ as a key molecular factor in the etiology of Alzheimer disease remains controversial, clinical trials of amyloid-lowering agents, reviewed elsewhere in this book, are poised to resolve the question of its pathogenic primacy.
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Affiliation(s)
- Colin L Masters
- The Mental Health Research Institute, The University of Melbourne, Parkville 3010, Australia.
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Yamada M, Naiki H. Cerebral Amyloid Angiopathy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 107:41-78. [DOI: 10.1016/b978-0-12-385883-2.00006-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Morales-Corraliza J, Berger JD, Mazzella MJ, Veeranna, Neubert TA, Ghiso J, Rao MV, Staufenbiel M, Nixon RA, Mathews PM. Calpastatin modulates APP processing in the brains of β-amyloid depositing but not wild-type mice. Neurobiol Aging 2011; 33:1125.e9-18. [PMID: 22206846 DOI: 10.1016/j.neurobiolaging.2011.11.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/15/2011] [Accepted: 11/20/2011] [Indexed: 11/27/2022]
Abstract
We report that neuronal overexpression of the endogenous inhibitor of calpains, calpastatin (CAST), in a mouse model of human Alzheimer's disease (AD) β-amyloidosis, the APP23 mouse, reduces β-amyloid (Aβ) pathology and Aβ levels when comparing aged, double transgenic (tg) APP23/CAST with APP23 mice. Concurrent with Aβ plaque deposition, aged APP23/CAST mice show a decrease in the steady-state brain levels of the amyloid precursor protein (APP) and APP C-terminal fragments (CTFs) when compared with APP23 mice. This CAST-dependent decrease in APP metabolite levels was not observed in single tg CAST mice expressing endogenous APP or in younger, Aβ plaque predepositing APP23/CAST mice. We also determined that the CAST-mediated inhibition of calpain activity in the brain is greater in the CAST mice with Aβ pathology than in non-APP tg mice, as demonstrated by a decrease in calpain-mediated cytoskeleton protein cleavage. Moreover, aged APP23/CAST mice have reduced extracellular signal-regulated kinase 1/2 (ERK1/2) activity and tau phosphorylation when compared with APP23 mice. In summary, in vivo calpain inhibition mediated by CAST transgene expression reduces Aβ pathology in APP23 mice, with our findings further suggesting that APP metabolism is modified by CAST overexpression as the mice develop Aβ pathology. Our results indicate that the calpain system in neurons is more responsive to CAST inhibition under conditions of Aβ pathology, suggesting that in the disease state neurons may be more sensitive to the therapeutic use of calpain inhibitors.
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Shimada T, Toyama A, Aoki C, Aoki Y, Tanaka K, Sato TA. Direct antigen detection from immunoprecipitated beads using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; a new method for immunobeads-mass spectrometry (iMS). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2011; 25:3521-3526. [PMID: 22095500 DOI: 10.1002/rcm.5259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
One-step detection of biological molecules is one of the principal techniques for clinical diagnosis, and the potential of mass spectrometry for biomarker detection has been a promising new approach in the field of medical sciences. We demonstrate here a new and high-sensitivity method that we termed immunobeads-mass spectrometry (iMS), which combines conventional immunoprecipitation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The key feature of iMS is the MS-compatible condition of immunoprecipitation using detergents with a monosaccaride-C8 alkyl chain or a disaccharide-C10 alkyl chain, and the minimized number of steps required for high-sensitivity detection of target peptides in serum or biological fluid. This was achieved by optimizing the wash buffer and subjecting the immunobeads directly to MALDI-TOF MS analysis. Using this method, we showed that 1 fmol of amyloid beta peptide spiked in serum was readily detectable, demonstrating the powerful tool of iMS as a biomarker detection method.
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Affiliation(s)
- Takashi Shimada
- Life Science Research Center, Shimadzu Corporation, Kanda-Nishikicho 1, Tokyo 101-8448, Japan
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Hernandez-Guillamon M, Mawhirt S, Fossati S, Blais S, Pares M, Penalba A, Boada M, Couraud PO, Neubert TA, Montaner J, Ghiso J, Rostagno A. Matrix metalloproteinase 2 (MMP-2) degrades soluble vasculotropic amyloid-beta E22Q and L34V mutants, delaying their toxicity for human brain microvascular endothelial cells. J Biol Chem 2010; 285:27144-27158. [PMID: 20576603 PMCID: PMC2930713 DOI: 10.1074/jbc.m110.135228] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/21/2010] [Indexed: 11/06/2022] Open
Abstract
Patients carrying mutations within the amyloid-beta (Abeta) sequence develop severe early-onset cerebral amyloid angiopathy with some of the related variants manifesting primarily with hemorrhagic phenotypes. Matrix metalloproteases (MMPs) are typically associated with blood brain barrier disruption and hemorrhagic transformations after ischemic stroke. However, their contribution to cerebral amyloid angiopathy-related hemorrhage remains unclear. Human brain endothelial cells challenged with Abeta synthetic homologues containing mutations known to be associated in vivo with hemorrhagic manifestations (AbetaE22Q and AbetaL34V) showed enhanced production and activation of MMP-2, evaluated via Multiplex MMP antibody arrays, gel zymography, and Western blot, which in turn proteolytically cleaved in situ the Abeta peptides. Immunoprecipitation followed by mass spectrometry analysis highlighted the generation of specific C-terminal proteolytic fragments, in particular the accumulation of Abeta-(1-16), a result validated in vitro with recombinant MMP-2 and quantitatively evaluated using deuterium-labeled internal standards. Silencing MMP-2 gene expression resulted in reduced Abeta degradation and enhanced apoptosis. Secretion and activation of MMP-2 as well as susceptibility of the Abeta peptides to MMP-2 degradation were dependent on the peptide conformation, with fibrillar elements of AbetaE22Q exhibiting negligible effects. Our results indicate that MMP-2 release and activation differentially degrades Abeta species, delaying their toxicity for endothelial cells. However, taking into consideration MMP ability to degrade basement membrane components, these protective effects might also undesirably compromise blood brain barrier integrity and precipitate a hemorrhagic phenotype.
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Affiliation(s)
- Mar Hernandez-Guillamon
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Stephanie Mawhirt
- Department of Pathology, New York University School of Medicine, New York, New York 10016
| | - Silvia Fossati
- Department of Pathology, New York University School of Medicine, New York, New York 10016
| | - Steven Blais
- Department of Pharmacology, , New York University School of Medicine, New York, New York 10016; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016
| | - Mireia Pares
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Anna Penalba
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Merce Boada
- Neurovascular Unit, Department of Neurology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | | | - Thomas A Neubert
- Department of Pharmacology, , New York University School of Medicine, New York, New York 10016; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016
| | - Joan Montaner
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; Neurovascular Unit, Department of Neurology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, New York 10016; Department of Psychiatry, New York University School of Medicine, New York, New York 10016
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, New York 10016.
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