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Hojjati SH, Chiang GC, Butler TA, de Leon M, Gupta A, Li Y, Sabuncu MR, Feiz F, Nayak S, Shteingart J, Ozoria S, Gholipour Picha S, Stern Y, Luchsinger JA, Devanand DP, Razlighi QR. Remote Associations Between Tau and Cortical Amyloid-β Are Stage-Dependent. J Alzheimers Dis 2024; 98:1467-1482. [PMID: 38552116 DOI: 10.3233/jad-231362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Background Histopathologic studies of Alzheimer's disease (AD) suggest that extracellular amyloid-β (Aβ) plaques promote the spread of neurofibrillary tau tangles. However, these two proteinopathies initiate in spatially distinct brain regions, so how they interact during AD progression is unclear. Objective In this study, we utilized Aβ and tau positron emission tomography (PET) scans from 572 older subjects (476 healthy controls (HC), 14 with mild cognitive impairment (MCI), 82 with mild AD), at varying stages of the disease, to investigate to what degree tau is associated with cortical Aβ deposition. Methods Using multiple linear regression models and a pseudo-longitudinal ordering technique, we investigated remote tau-Aβ associations in four pathologic phases of AD progression based on tau spread: 1) no-tau, 2) pre-acceleration, 3) acceleration, and 4) post-acceleration. Results No significant tau-Aβ association was detected in the no-tau phase. In the pre-acceleration phase, the earliest stage of tau deposition, associations emerged between regional tau in medial temporal lobe (MTL) (i.e., entorhinal cortex, parahippocampal gyrus) and cortical Aβ in lateral temporal lobe regions. The strongest tau-Aβ associations were found in the acceleration phase, in which tau in MTL regions was strongly associated with cortical Aβ (i.e., temporal and frontal lobes regions). Strikingly, in the post-acceleration phase, including 96% of symptomatic subjects, tau-Aβ associations were no longer significant. Conclusions The results indicate that associations between tau and Aβ are stage-dependent, which could have important implications for understanding the interplay between these two proteinopathies during the progressive stages of AD.
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Affiliation(s)
- Seyed Hani Hojjati
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Gloria C Chiang
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Tracy A Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Mony de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Ajay Gupta
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Yi Li
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Mert R Sabuncu
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Farnia Feiz
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Siddharth Nayak
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Jacob Shteingart
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Sindy Ozoria
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
| | - Saman Gholipour Picha
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Yaakov Stern
- Departments of Neurology, Psychiatry, GH Sergievsky Center, The Taub Institute for the Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
| | - José A Luchsinger
- Departments of Medicine and Epidemiology, Columbia University Irving Medical Center, New York, NY, USA
| | - Davangere P Devanand
- Division of Geriatric Psychiatry, New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, USA
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY, USA
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY, USA
| | - Qolamreza R Razlighi
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, USA
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2
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Xu Y, Jiang H, Zhu B, Cao M, Feng T, Sun Z, Du G, Zhao Z. Advances and applications of fluids biomarkers in diagnosis and therapeutic targets of Alzheimer's disease. CNS Neurosci Ther 2023. [PMID: 37144603 DOI: 10.1111/cns.14238] [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: 08/24/2022] [Revised: 01/25/2023] [Accepted: 04/12/2023] [Indexed: 05/06/2023] Open
Abstract
AIMS Alzheimer's disease (AD) is a neurodegenerative disease with challenging early diagnosis and effective treatments due to its complex pathogenesis. AD patients are often diagnosed after the appearance of the typical symptoms, thereby delaying the best opportunity for effective measures. Biomarkers could be the key to resolving the challenge. This review aims to provide an overview of application and potential value of AD biomarkers in fluids, including cerebrospinal fluid, blood, and saliva, in diagnosis and treatment. METHODS A comprehensive search of the relevant literature was conducted to summarize potential biomarkers for AD in fluids. The paper further explored the biomarkers' utility in disease diagnosis and drug target development. RESULTS Research on biomarkers mainly focused on amyloid-β (Aβ) plaques, Tau protein abnormal phosphorylation, axon damage, synaptic dysfunction, inflammation, and related hypotheses associated with AD mechanisms. Aβ42 , total Tau (t-Tau), and phosphorylated Tau (p-Tau), have been endorsed for their diagnostic and predictive capability. However, other biomarkers remain controversial. Drugs targeting Aβ have shown some efficacy and those that target BACE1 and Tau are still undergoing development. CONCLUSION Fluid biomarkers hold considerable potential in the diagnosis and drug development of AD. However, improvements in sensitivity and specificity, and approaches for managing sample impurities, need to be addressed for better diagnosis.
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Affiliation(s)
- Yanan Xu
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- School of Pharmacy, Capital Medical University, Beijing, China
| | - Hailun Jiang
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Bin Zhu
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Mingnan Cao
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Tao Feng
- Center for Movement Disorders, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhongshi Sun
- Department of Pharmacy, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Guanhua Du
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Beijing, China
- Key Laboratory of Drug Target Research and Drug Screen, Institute of Materia Medica, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Zhigang Zhao
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- School of Pharmacy, Capital Medical University, Beijing, China
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3
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Leyder E, Suresh P, Jun R, Overbey K, Banerjee T, Melnikova T, Savonenko A. Depression-related phenotypes at early stages of Aβ and tau accumulation in inducible Alzheimer's disease mouse model: Task-oriented and concept-driven interpretations. Behav Brain Res 2023; 438:114187. [PMID: 36343696 DOI: 10.1016/j.bbr.2022.114187] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 10/16/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022]
Abstract
Depression is highly prevalent in Alzheimer Disease (AD); however, there is paucity of studies that focus specifically on the assessment of depression-relevant phenotypes in AD mouse models. Conditional doxycycline-dependent transgenic mouse models reproducing amyloidosis (TetOffAPPsi) and/or tau (TetOffTauP301L) pathology starting at middle age (6 months) were used in this study. As AD patients can experience depressive symptoms relatively early in disease, testing was conducted at early, pre-pathology stages of Aβ and/or tau accumulation (starting from 45 days of transgenes expression). Tau-related differences were detected in the Novelty Suppressed Feeding task (NSF), whereas APP-related differences were observed predominantly in measures of the Open Field (OF) and Forced Swim tasks (FST). Effects of combined production of Aβ and tau were detected in immobility during the 1st half of the Tail Suspension task (TST). These data demonstrate that results from different tasks are difficult to reconcile using task/variable-centered interpretations in which a single task/variable is assigned an ad-hoc meaning relevant to depression. An alternative, concept-oriented, approach is based on multiple variables/tests, with an understanding of their possible inter-dependence and utilization of statistical approaches that handle correlated data sets. The existence of strong correlations within and between some of the tasks supported utilization of factor analyses (FA). FA explained a similar amount of variability across the genotypes (∼80%) and identified two factors stable across genotypes and representing motor activity and anxiety measures in OF. In contrast, variables related to FST, TST, and NSFT did not demonstrate a structure of factor loadings that would support the existence of a single integral factor of "depressive state" measured by these tasks. In addition, factor loadings varied between genotypes, indicating that genotype-specific between-task correlations need to be considered for interpretations of findings in any single task. In general, this study demonstrates that utilization of multiple tasks to characterize behavioral phenotypes, an approach that is finally gaining more widespread adoption, requires a step of data integration across different behavioral tests for appropriate interpretations.
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Affiliation(s)
- Erica Leyder
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Prakul Suresh
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Rachel Jun
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Katherine Overbey
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Tirtho Banerjee
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Tatiana Melnikova
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
| | - Alena Savonenko
- Department of Pathology, The Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
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White H, Webb R, McKnight I, Legg K, Lee C, Lee PH, Spicer OS, Shim JW. TRPV4 mRNA is elevated in the caudate nucleus with NPH but not in Alzheimer's disease. Front Genet 2022; 13:936151. [PMID: 36406122 PMCID: PMC9670164 DOI: 10.3389/fgene.2022.936151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 10/17/2022] [Indexed: 01/04/2023] Open
Abstract
Symptoms of normal pressure hydrocephalus (NPH) and Alzheimer's disease (AD) are somewhat similar, and it is common to misdiagnose these two conditions. Although there are fluid markers detectable in humans with NPH and AD, determining which biomarker is optimal in representing genetic characteristics consistent throughout species is poorly understood. Here, we hypothesize that NPH can be differentiated from AD with mRNA biomarkers of unvaried proximity to telomeres. We examined human caudate nucleus tissue samples for the expression of transient receptor potential cation channel subfamily V member 4 (TRPV4) and amyloid precursor protein (APP). Using the genome data viewer, we analyzed the mutability of TRPV4 and other genes in mice, rats, and humans through matching nucleotides of six genes of interest and one house keeping gene with two factors associated with high mutation rate: 1) proximity to telomeres or 2) high adenine and thymine (A + T) content. We found that TRPV4 and microtubule associated protein tau (MAPT) mRNA were elevated in NPH. In AD, mRNA expression of TRPV4 was unaltered unlike APP and other genes. In mice, rats, and humans, the nucleotide size of TRPV4 did not vary, while in other genes, the sizes were inconsistent. Proximity to telomeres in TRPV4 was <50 Mb across species. Our analyses reveal that TRPV4 gene size and mutability are conserved across three species, suggesting that TRPV4 can be a potential link in the pathophysiology of chronic hydrocephalus in aged humans (>65 years) and laboratory rodents at comparable ages.
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Affiliation(s)
- Hunter White
- Department of Biomedical Engineering, Marshall University, Huntington, WV, United States
| | - Ryan Webb
- Department of Biomedical Engineering, Marshall University, Huntington, WV, United States
| | - Ian McKnight
- Department of Biomedical Engineering, Marshall University, Huntington, WV, United States
| | - Kaitlyn Legg
- Department of Biomedical Engineering, Marshall University, Huntington, WV, United States
| | - Chan Lee
- Department of Anesthesia, Indiana University Health Arnett Hospital, Lafayette, IN, United States
| | - Peter H.U. Lee
- Department of Cardiothoracic Surgery, Southcoast Health, Fall River, MA, United States,Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, United States
| | - Olivia Smith Spicer
- National Institute of Mental Health, National Institute of Health, Bethesda, MD, United States
| | - Joon W. Shim
- Department of Biomedical Engineering, Marshall University, Huntington, WV, United States,*Correspondence: Joon W. Shim,
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5
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Lee WJ, Brown JA, Kim HR, La Joie R, Cho H, Lyoo CH, Rabinovici GD, Seong JK, Seeley WW. Regional Aβ-tau interactions promote onset and acceleration of Alzheimer's disease tau spreading. Neuron 2022; 110:1932-1943.e5. [PMID: 35443153 DOI: 10.1016/j.neuron.2022.03.034] [Citation(s) in RCA: 68] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/19/2022] [Accepted: 03/28/2022] [Indexed: 12/22/2022]
Abstract
Amyloid-beta and tau are key molecules in the pathogenesis of Alzheimer's disease, but it remains unclear how these proteins interact to promote disease. Here, by combining cross-sectional and longitudinal molecular imaging and network connectivity analyses in living humans, we identified two amyloid-beta/tau interactions associated with the onset and propagation of tau spreading. First, we show that the lateral entorhinal cortex, an early site of tau neurofibrillary tangle formation, is subject to remote, connectivity-mediated amyloid-beta/tau interactions linked to initial tau spreading. Second, we identify the inferior temporal gyrus as the region featuring the greatest local amyloid-beta/tau interactions and a connectivity profile well suited to accelerate tau propagation. Taken together, our data address long-standing questions regarding the topographical dissimilarity between early amyloid-beta and tau deposition.
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Affiliation(s)
- Wha Jin Lee
- School of Biomedical Engineering, Korea University, Seoul 02841, South Korea
| | - Jesse A Brown
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA 94143, USA; Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hye Ryun Kim
- School of Biomedical Engineering, Korea University, Seoul 02841, South Korea; Global Health Technology Research Center, College of Health Science, Korea University, Seoul 02841, South Korea
| | - Renaud La Joie
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA 94143, USA; Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hanna Cho
- Department of Neurology, Gangnam Severance Hospital, Seoul 06273, South Korea
| | - Chul Hyoung Lyoo
- Department of Neurology, Gangnam Severance Hospital, Seoul 06273, South Korea
| | - Gil D Rabinovici
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA 94143, USA; Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joon-Kyung Seong
- School of Biomedical Engineering, Korea University, Seoul 02841, South Korea; Department of Artificial Intelligence, Korea University, Seoul 02841, South Korea.
| | - William W Seeley
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA 94143, USA; Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA.
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6
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Silva PCD, de Oliveira LLV, Teixeira RLP, Brito MLDA, Filippe ARTM. Executive Functions in Alzheimer’s Disease: A Systematic Review. J Alzheimers Dis Rep 2022. [DOI: 10.3233/adr-210059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: In Alzheimer’s disease, in addition to memory, attention has been given to cognitive testing due to its interface and connection with memory. Objective: The aim of this study is to take a global view of executive functions and place the concept within the theoretical framework of Alzheimer’s disease dementia, verifying their role in the cognitive functioning of the human mind, as well as how they are compromised in this pathology. Methods: An initial search was carried out in databases such as PubMed, ScienceDirect, and Web of Science. The guiding question presented at the end of the introduction was elaborated from the PICO/PIO/PEO strategy. The selected articles, therefore, answered the guiding question, were made available in full, and published in the period from 2000 to 2020. Studies without specific methodology and which correlated with other diseases or other types of dementia were excluded. To meet the objective, an integrative literature review was adopted. Results: The results indicate that, although the tests to verify the performance of cognitive functions have their limitations, they bring some evidence that they have been compromised, especially when analyzed periodically during the development of dementia. Conclusion: It is concluded that there is an interference of executive functions in function of Alzheimer’s and that memory and attention are the most evident in this type of dementia.
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Affiliation(s)
| | | | | | - Max Leandro de Araújo Brito
- Faculdade de Engenharia, Letras e Ciências Sociais do Seridó da Universidade Federal do Rio Grande do Norte, State of Rio Grande do Norte, Brazil
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7
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Schäfer A, Peirlinck M, Linka K, Kuhl E. Bayesian Physics-Based Modeling of Tau Propagation in Alzheimer's Disease. Front Physiol 2021; 12:702975. [PMID: 34335308 PMCID: PMC8322942 DOI: 10.3389/fphys.2021.702975] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/22/2021] [Indexed: 11/24/2022] Open
Abstract
Amyloid-β and hyperphosphorylated tau protein are known drivers of neuropathology in Alzheimer's disease. Tau in particular spreads in the brains of patients following a spatiotemporal pattern that is highly sterotypical and correlated with subsequent neurodegeneration. Novel medical imaging techniques can now visualize the distribution of tau in the brain in vivo, allowing for new insights to the dynamics of this biomarker. Here we personalize a network diffusion model with global spreading and local production terms to longitudinal tau positron emission tomography data of 76 subjects from the Alzheimer's Disease Neuroimaging Initiative. We use Bayesian inference with a hierarchical prior structure to infer means and credible intervals for our model parameters on group and subject levels. Our results show that the group average protein production rate for amyloid positive subjects is significantly higher with 0.019±0.27/yr, than that for amyloid negative subjects with -0.143±0.21/yr (p = 0.0075). These results support the hypothesis that amyloid pathology drives tau pathology. The calibrated model could serve as a valuable clinical tool to identify optimal time points for follow-up scans and predict the timeline of disease progression.
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Affiliation(s)
- Amelie Schäfer
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Mathias Peirlinck
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Kevin Linka
- Institute of Continuum and Materials Mechanics, Hamburg University of Technology, Hamburg, Germany
| | - Ellen Kuhl
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
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8
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Salvadó G, Grothe MJ, Groot C, Moscoso A, Schöll M, Gispert JD, Ossenkoppele R. Differential associations of APOE-ε2 and APOE-ε4 alleles with PET-measured amyloid-β and tau deposition in older individuals without dementia. Eur J Nucl Med Mol Imaging 2021; 48:2212-2224. [PMID: 33521872 PMCID: PMC8175302 DOI: 10.1007/s00259-021-05192-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/03/2021] [Indexed: 01/07/2023]
Abstract
PURPOSE To examine associations between the APOE-ε2 and APOE-ε4 alleles and core Alzheimer's disease (AD) pathological hallmarks as measured by amyloid-β (Aβ) and tau PET in older individuals without dementia. METHODS We analyzed data from 462 ADNI participants without dementia who underwent Aβ ([18F]florbetapir or [18F]florbetaben) and tau ([18F]flortaucipir) PET, structural MRI, and cognitive testing. Employing APOE-ε3 homozygotes as the reference group, associations between APOE-ε2 and APOE-ε4 carriership with global Aβ PET and regional tau PET measures (entorhinal cortex (ERC), inferior temporal cortex, and Braak-V/VI neocortical composite regions) were investigated using linear regression models. In a subset of 156 participants, we also investigated associations between APOE genotype and regional tau accumulation over time using linear mixed models. Finally, we assessed whether Aβ mediated the cross-sectional and longitudinal associations between APOE genotype and tau. RESULTS Compared to APOE-ε3 homozygotes, APOE-ε2 carriers had lower global Aβ burden (βstd [95% confidence interval (CI)]: - 0.31 [- 0.45, - 0.16], p = 0.034) but did not differ on regional tau burden or tau accumulation over time. APOE-ε4 participants showed higher Aβ (βstd [95%CI]: 0.64 [0.42, 0.82], p < 0.001) and tau burden (βstd range: 0.27-0.51, all p < 0.006). In mediation analyses, APOE-ε4 only retained an Aβ-independent effect on tau in the ERC. APOE-ε4 showed a trend towards increased tau accumulation over time in Braak-V/VI compared to APOE-ε3 homozygotes (βstd [95%CI]: 0.10 [- 0.02, 0.18], p = 0.11), and this association was fully mediated by baseline Aβ. CONCLUSION Our data suggest that the established protective effect of the APOE-ε2 allele against developing clinical AD is primarily linked to resistance against Aβ deposition rather than tau pathology.
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Affiliation(s)
- Gemma Salvadó
- Alzheimer Prevention Program, Barcelonaβeta Brain Research Center (BBRC), Pasqual Maragall Foundation, C/ Wellington, 30 08005, Barcelona, Spain.
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands.
| | - Michel J Grothe
- Wallenberg Centre for Molecular and Translational Medicine, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
- Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Avda. Manuel Siurot, s/n 41013, Seville, Spain.
| | - Colin Groot
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Alexis Moscoso
- Wallenberg Centre for Molecular and Translational Medicine, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Michael Schöll
- Wallenberg Centre for Molecular and Translational Medicine, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
- Dementia Research Centre, Institute of Neurology, University College London, London, UK
| | - Juan Domingo Gispert
- Alzheimer Prevention Program, Barcelonaβeta Brain Research Center (BBRC), Pasqual Maragall Foundation, C/ Wellington, 30 08005, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Madrid, Spain
| | - Rik Ossenkoppele
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
- Clinical Memory Research Unit, Lund University, Lund, Sweden
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Steinman J, Sun HS, Feng ZP. Microvascular Alterations in Alzheimer's Disease. Front Cell Neurosci 2021; 14:618986. [PMID: 33536876 PMCID: PMC7849053 DOI: 10.3389/fncel.2020.618986] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/17/2020] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with continual decline in cognition and ability to perform routine functions such as remembering familiar places or understanding speech. For decades, amyloid beta (Aβ) was viewed as the driver of AD, triggering neurodegenerative processes such as inflammation and formation of neurofibrillary tangles (NFTs). This approach has not yielded therapeutics that cure the disease or significant improvements in long-term cognition through removal of plaques and Aβ oligomers. Some researchers propose alternate mechanisms that drive AD or act in conjunction with amyloid to promote neurodegeneration. This review summarizes the status of AD research and examines research directions including and beyond Aβ, such as tau, inflammation, and protein clearance mechanisms. The effect of aging on microvasculature is highlighted, including its contribution to reduced blood flow that impairs cognition. Microvascular alterations observed in AD are outlined, emphasizing imaging studies of capillary malfunction. The review concludes with a discussion of two therapies to protect tissue without directly targeting Aβ for removal: (1) administration of growth factors to promote vascular recovery in AD; (2) inhibiting activity of a calcium-permeable ion channels to reduce microglial activation and restore cerebral vascular function.
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Affiliation(s)
- Joe Steinman
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hong-Shuo Sun
- Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Zhong-Ping Feng
- Department of Physiology, University of Toronto, Toronto, ON, Canada
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10
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Wang M, Yan Z, Zhang H, Lu J, Li L, Yu J, Wang J, Matsuda H, Zuo C, Jiang J. Parametric estimation of reference signal intensity in the quantification of amyloid-beta deposition: an 18F-AV-45 study. Quant Imaging Med Surg 2021; 11:249-263. [PMID: 33392026 PMCID: PMC7719939 DOI: 10.21037/qims-20-110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 09/07/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Positron emission tomography (PET) with the radiotracer florbetapir (18F-AV-45) allows the pathophysiology of Alzheimer's disease (AD) to be tracked in vivo. The semi-quantification of amyloid-beta (Aβ) has been extensively evaluated with the standardized uptake value ratio (SUVR) but is susceptible to disturbance from the candidate reference region and the partial volume effect (PVE). In the present study, we applied the parametric estimation of reference signal intensity (PERSI) method to 18F-AV-45 PET images for intensity normalization. METHODS We enrolled 479 people with 18F-AV-45 images from the Alzheimer's Disease Neuroimaging Initiative database: 261 healthy controls (HCs), 102 patients with mild cognitive impairment (MCI), and 116 AD patients. We used white matter post-processed by PERSI (PERSI-WM) as the reference region and compared our proposed method with the traditional method for semi-quantification. SUVRs were calculated for eight regions of interest: the frontal lobe, the parietal lobe, the temporal lobe, the occipital lobe, the anterior cingulate cortex, the posterior cingulate cortex, the precuneus, and the global cortex. The SUVRs derived from PERSI-WM and other reference regions were evaluated by effect size and receiver-operator characteristic curve analyses. RESULTS The SUVRs derived from PERSI-WM showed significantly higher trace retention in the frontal, parietal, temporal, and occipital lobes, as well as in the anterior cingulate, posterior cingulate, precuneus, and global cortex in the AD Aβ-positive (+) group (mean: +43.3%±5.4%, P<0.01) and MCI Aβ+ group (mean: +29.6%±5.3%, P<0.01). For the global cortex, PERSI-WM had the greatest Cohen's d effect size compared with the HC Aβ-negative (-) group (AD Aβ+ and MCI Aβ+: 3.02, AD Aβ+: 3.56, MCI Aβ+: 2.34), and the highest area under the curve (AUC) between the HC Aβ- and AD Aβ+ groups (AUC: 0.983, 95% confidence interval: 0.978-0.998). CONCLUSIONS PERSI-WM could mitigate the influence of PVE and improve the semi-quantification of 18F-AV-45 images; therefore, it could be used for large-scale clinical application in the nuclear medicine domain.
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Affiliation(s)
- Min Wang
- Shanghai Institute for Advanced Communication and Data Science, School of Communication and Information Engineering, Shanghai University, Shanghai, China
- Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, Shanghai, China
| | - Zhuangzhi Yan
- Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, Shanghai, China
| | - Huiwei Zhang
- PET Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiaying Lu
- PET Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ling Li
- PET Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jintai Yu
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jian Wang
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hiroshi Matsuda
- Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiehui Jiang
- Shanghai Institute for Advanced Communication and Data Science, School of Communication and Information Engineering, Shanghai University, Shanghai, China
- Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, Shanghai, China
| | - the Alzheimer’s Disease Neuroimaging Initiative
- Shanghai Institute for Advanced Communication and Data Science, School of Communication and Information Engineering, Shanghai University, Shanghai, China
- Institute of Biomedical Engineering, School of Communication and Information Engineering, Shanghai University, Shanghai, China
- PET Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
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11
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Mahendran TS, Suresh SN, Garimella L, Manjithaya R. Soluble 4R0N Tau Abrogates Endocytic Vesicular Dynamics. Front Aging Neurosci 2020; 12:537712. [PMID: 33250760 PMCID: PMC7676905 DOI: 10.3389/fnagi.2020.537712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 09/18/2020] [Indexed: 11/13/2022] Open
Abstract
Aggregated tau is a hallmark neuropathological feature in numerous neurodegenerative disorders. Previous studies aiming to validate aggregated tau pathology as a pathogenic driver of neurodegeneration in correlation to characteristic behavioral phenotypes have had shortcomings. Although studies on soluble tau pathology have effectively addressed these shortcomings, the role of soluble tau in the molecular pathogenesis of neurodegeneration is not yet unequivocally established. In sporadic Alzheimer's disease (AD), the relevance of soluble tau pathology in endolysosomal dysfunction and autophagic stress, some of the earliest disease manifestations, is unclear. In this study, we report that soluble 4R0N tau overexpression affects the expression levels of certain markers associated with the endolysosomal system and autophagy. Moreover, through live-cell imaging, we found that the vesicular dynamics of early endosomes were affected with respect to spatiotemporal parameters and vesicle maturation. Additionally, we observed the localization of amyloid precursor protein (APP) along the endocytic pathway and found that upon overexpression of soluble 4R0N tau, APP was preferentially localized to the endocytic compartments implicated in the amyloidogenic pathway. Overall, our observations indicate that soluble 4R0N tau abrogates the dynamics of the endolysosomal system, autophagy, and affects the trafficking of APP. Since the amyloidogenic processing of APP occurs during its progression through the endocytic pathway, our results suggest that the generation of amyloid-β (Aβ) might also be modulated.
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Affiliation(s)
- Tharun Selvam Mahendran
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - S N Suresh
- Centre for Brain Research, Indian Institute of Science, Bangalore, India
| | - Lakshmi Garimella
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Ravi Manjithaya
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India.,Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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12
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Caselli RJ, Knopman DS, Bu G. An agnostic reevaluation of the amyloid cascade hypothesis of Alzheimer's disease pathogenesis: The role of APP homeostasis. Alzheimers Dement 2020; 16:1582-1590. [PMID: 32588983 DOI: 10.1002/alz.12124] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 05/03/2020] [Accepted: 05/06/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To reassess the role of amyloid beta (Aβ) and the amyloid precursor protein (APP) system in the pathogenesis of Alzheimer's disease (AD). BACKGROUND APP is a cell adhesion molecule that has been highly conserved over the course of phylogeny that has critical roles in brain development, synaptic plasticity, and the brain's intrinsic immune system. The amyloid cascade hypothesis describes a relatively linear, deterministic sequence of events triggered by a gain of Aβ peptide fragment toxicity that results in neurodegeneration and cognitive loss, yet well designed immunotherapy and beta secretase inhibitor trials that have successfully targeted Aβ have failed to have any consistent effects on the steady decline of cognition. NEW/UPDATED HYPOTHESIS Mutations of the APP and presenilin genes not only alter the ratio of longer to shorter Aβ fragments (resulting in a gain of Aβ toxicity), but also disrupt the normal homeostatic roles of their respective proteins. The evolutionary history, physiological importance, and complexity of the APP and presenilin systems, as well as other critical components including tau and apolipoprotein E (APOE) imply that altered function of such systems could have severe consequences that include but need not be limited to a gain of Aβ toxicity and would more generally result in altered homeostasis of APP-related functions. MAJOR CHALLENGES ADDRESSED BY OUR HYPOTHESIS Challenges that a loss of APP homeostasis addresses better than the more limited gain of Aβ toxicity model include the topographic mismatches between Aβ and tau pathology, the profile and chronology of cognitive and biomarker changes that precede the clinical expression of mild cognitive impairment and dementia, and the disappointments of Aβ targeted therapeutics among others. LINKAGE TO OTHER MAJOR THEORIES The importance of APP, α- and β-secretases, the presenilins and γ-secretase, as well as tau was recognized by the authors of the amyloid cascade hypothesis, and has since led multiple investigators to propose alternative, more balanced hypotheses including reduced homeostasis and frank loss-of-function of key components that include but go beyond the currently envisioned linear model of Aβ toxicity.
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Affiliation(s)
- Richard J Caselli
- Department of Neurology, Mayo Clinic Arizona, Scottsdale, Arizona, USA
| | - David S Knopman
- Department of Neurology, Mayo Clinic Rochester, Rochester, Minnesota, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, Florida, USA
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13
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Castor KJ, Shenoi S, Edminster SP, Tran T, King KS, Chui H, Pogoda JM, Fonteh AN, Harrington MG. Urine dicarboxylic acids change in pre-symptomatic Alzheimer's disease and reflect loss of energy capacity and hippocampal volume. PLoS One 2020; 15:e0231765. [PMID: 32298384 PMCID: PMC7162508 DOI: 10.1371/journal.pone.0231765] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Non-invasive biomarkers will enable widespread screening and early diagnosis of Alzheimer’s disease (AD). We hypothesized that the considerable loss of brain tissue in AD will result in detection of brain lipid components in urine, and that these will change in concert with CSF and brain biomarkers of AD. We examined urine dicarboxylic acids (DCA) of carbon length 3–10 to reflect products of oxidative damage and energy generation or balance that may account for changes in brain function in AD. Mean C4-C5 DCAs were lower and mean C7-C10 DCAs were higher in the urine from AD compared to cognitively healthy (CH) individuals. Moreover, mean C4-C5 DCAs were lower and mean C7-C9 were higher in urine from CH individuals with abnormal compared to normal CSF amyloid and Tau levels; i.e., the apparent urine changes in AD also appeared to be present in CH individuals that have CSF risk factors of early AD pathology. In examining the relationship between urine DCAs and AD biomarkers, we found short chain DCAs positively correlated with CSF Aβ42, while C7-C10 DCAs negatively correlated with CSF Aβ42 and positively correlated with CSF Tau levels. Furthermore, we found a negative correlation of C7-C10 DCAs with hippocampal volume (p < 0.01), which was not found in the occipital volume. Urine measures of DCAs have an 82% ability to predict cognitively healthy participants with normal CSF amyloid/Tau. These data suggest that urine measures of increased lipoxidation and dysfunctional energy balance reflect early AD pathology from brain and CSF biomarkers. Measures of urine DCAs may contribute to personalized healthcare by indicating AD pathology and may be utilized to explore population wellness or monitor the efficacy of therapies in clinical trials.
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Affiliation(s)
- K. J. Castor
- Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States of America
| | - S. Shenoi
- Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States of America
| | - S. P. Edminster
- Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States of America
| | - T. Tran
- Clinical MR Unit, Huntington Medical Research Institutes, Pasadena, CA, United States of America
| | - K. S. King
- Clinical MR Unit, Huntington Medical Research Institutes, Pasadena, CA, United States of America
| | - H. Chui
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - J. M. Pogoda
- Cipher Biostatistics & Reporting, Reno, NV, United States of America
| | - A. N. Fonteh
- Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States of America
- * E-mail: (ANF); (MGH)
| | - M. G. Harrington
- Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, United States of America
- * E-mail: (ANF); (MGH)
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14
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Gaudreault R, Mousseau N. Mitigating Alzheimer’s Disease with Natural Polyphenols: A Review. Curr Alzheimer Res 2019; 16:529-543. [DOI: 10.2174/1567205016666190315093520] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/14/2019] [Accepted: 03/13/2019] [Indexed: 11/22/2022]
Abstract
:According to Alzheimer’s Disease International (ADI), nearly 50 million people worldwide were living with dementia in 2017, and this number is expected to triple by 2050. Despite years of research in this field, the root cause and mechanisms responsible for Alzheimer’s disease (AD) have not been fully elucidated yet. Moreover, promising preclinical results have repeatedly failed to translate into patient treatments. Until now, none of the molecules targeting AD has successfully passed the Phase III trial. Although natural molecules have been extensively studied, they normally require high concentrations to be effective; alternately, they are too large to cross the blood-brain barrier (BBB).:In this review, we report AD treatment strategies, with a virtually exclusive focus on green chemistry (natural phenolic molecules). These include therapeutic strategies for decreasing amyloid-β (Aβ) production, preventing and/or altering Aβ aggregation, and reducing oligomers cytotoxicity such as curcumin, (-)-epigallocatechin-3-gallate (EGCG), morin, resveratrol, tannic acid, and other natural green molecules. We also examine whether consideration should be given to potential candidates used outside of medicine and nutrition, through a discussion of two intermediate-sized green molecules, with very similar molecular structures and key properties, which exhibit potential in mitigating Alzheimer’s disease.
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Affiliation(s)
- Roger Gaudreault
- Department of Physics, Universit�© de Montr�©al, Case Postale 6128, Succursale Centre-ville, Montreal (QC), Canada
| | - Normand Mousseau
- Department of Physics, Universit�© de Montr�©al, Case Postale 6128, Succursale Centre-ville, Montreal (QC), Canada
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15
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Lee JH, Jahrling JB, Denner L, Dineley KT. Targeting Insulin for Alzheimer’s Disease: Mechanisms, Status and Potential Directions. J Alzheimers Dis 2018; 64:S427-S453. [DOI: 10.3233/jad-179923] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jung Hyun Lee
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Jordan B. Jahrling
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Larry Denner
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Kelly T. Dineley
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
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16
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Hofrichter J, Krohn M, Schumacher T, Lange C, Feistel B, Walbroel B, Pahnke J. Sideritis spp. Extracts Enhance Memory and Learning in Alzheimer's β-Amyloidosis Mouse Models and Aged C57Bl/6 Mice. J Alzheimers Dis 2018; 53:967-80. [PMID: 27258424 PMCID: PMC4981905 DOI: 10.3233/jad-160301] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Nowadays, Alzheimer’s disease is the most prevalent epiphenomenon of the aging population. Although soluble amyloid-β (Aβ) species (monomers, oligomers) are recognized triggers of the disease, no therapeutic approach is able to stop it. Herbal medicines are used to treat different diseases in many regions of the world. On the Balkan Peninsula, at the eastern Mediterranean Sea, and adjacent regions, Sideritis species are used as traditional medicine to prevent age-related problems in elderly. To evaluate this traditional knowledge in controlled experiments, we tested extracts of two commonly used Sideritis species, Sideritis euboea and Sideritis scardica, with regard to their effects on cognition in APP-transgenic and aged, non-transgenic C57Bl/6 mice. Additionally, histomorphological and biochemical changes associated with Aβ deposition and treatment were assessed. We found that daily oral treatment with Sideritis spp. extracts highly enhanced cognition in aged, non-transgenic as well as in APP-transgenic mice, an effect that was even more pronounced when extracts of both species were applied in combination. The treatment strongly reduced Aβ42 load in APP-transgenic mice, accompanied by increased phagocytic activity of microglia, and increased expression of the α-secretase ADAM10. Moreover, the treatment was able to fully rescue neuronal loss of APP-transgenic mice to normal levels as seen in non-transgenic controls. Having the traditional knowledge in mind, our results imply that treatment with Sideritis spp. extracts might be a potent, well-tolerated option for treating symptoms of cognitive impairment in elderly and with regard to Alzheimer’s disease by affecting its most prominent hallmarks: Aβ pathology and cognitive decline.
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Affiliation(s)
| | - Markus Krohn
- University of Oslo (UiO) and Oslo University Hospital (OUS), Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, Oslo, Norway.,University of Rostock, Department of Neurology, Rostock, Germany
| | - Toni Schumacher
- University of Rostock, Department of Neurology, Rostock, Germany
| | - Cathleen Lange
- University of Rostock, Department of Neurology, Rostock, Germany
| | | | | | - Jens Pahnke
- University of Oslo (UiO) and Oslo University Hospital (OUS), Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, Oslo, Norway.,University of Rostock, Department of Neurology, Rostock, Germany.,University of Lübeck, Lübeck (LIED), Lübeck, Germany.,Leibniz Institute for Plant Biochemistry (IPB), Halle, Germany
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17
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Ramanan VK, Przybelski SA, Graff-Radford J, Castillo AM, Lowe VJ, Mielke MM, Roberts RO, Reid RI, Knopman DS, Jack CR, Petersen RC, Vemuri P. Statins and Brain Health: Alzheimer's Disease and Cerebrovascular Disease Biomarkers in Older Adults. J Alzheimers Dis 2018; 65:1345-1352. [PMID: 30149450 PMCID: PMC6260813 DOI: 10.3233/jad-180446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Statins have been proposed to reduce the risk of Alzheimer's disease (AD). OBJECTIVE Assess whether long-term statin use was associated with neuroimaging biomarkers of aging and dementia. METHODS Methods: We analyzed neuroimaging biomarkers in 1,160 individuals aged 65+ from the Mayo Clinic Study of Aging, a population-based prospective longitudinal study of cognitive aging. RESULTS Statin-treated (5+ years of therapy) individuals had greater burden of mid-and late-life cardiovascular disease (p < 0.001) than statin-untreated (≤3 months) individuals. Lower fractional anisotropy in the genu of the corpus callosum, an early marker of cerebrovascular disease, was associated with long-term statin exposure (p < 0.035). No significant associations were identified between long-term statin exposure and cerebral amyloid or tau burden, AD pattern neurodegeneration, or white matter hyperintensity burden. CONCLUSIONS Long-term statin therapy was not associated with differences in AD biomarkers. Individuals with long-term statin exposure had worse white matter integrity in the genu of the corpus callosum, consistent with the coexistence of higher cerebrovascular risk factor burden in this group.
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Affiliation(s)
- Vijay K Ramanan
- Department of Neurology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Scott A. Przybelski
- Department of Health Sciences Research, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | | | - Anna M. Castillo
- Department of Health Sciences Research, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Val J. Lowe
- Department of Radiology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Michelle M. Mielke
- Department of Neurology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
- Department of Health Sciences Research, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Rosebud O. Roberts
- Department of Neurology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
- Department of Health Sciences Research, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Robert I. Reid
- Department of Information Technology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - David S. Knopman
- Department of Neurology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Clifford R. Jack
- Department of Radiology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Ronald C. Petersen
- Department of Neurology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
- Department of Health Sciences Research, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
| | - Prashanthi Vemuri
- Department of Radiology, Mayo Clinic-Rochester, Rochester, Minnesota, 55905, USA
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18
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Wu XL, Piña-Crespo J, Zhang YW, Chen XC, Xu HX. Tau-mediated Neurodegeneration and Potential Implications in Diagnosis and Treatment of Alzheimer's Disease. Chin Med J (Engl) 2017; 130:2978-2990. [PMID: 29237931 PMCID: PMC5742926 DOI: 10.4103/0366-6999.220313] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE To review recent research advances on tau, a major player in Alzheimer's disease (AD) pathogenesis, a biomarker for AD onset, and potential target for AD therapy. DATA SOURCES This review was based on a comprehensive search using online literature databases, including PubMed, Web of Science, and Google Scholar. STUDY SELECTION Literature search was based on the following keywords: Alzheimer's disease, tau protein, biomarker, cerebrospinal fluid (CSF), therapeutics, plasma, imaging, propagation, spreading, seeding, prion, conformational templating, and posttranslational modification. Relevant articles were carefully reviewed, with no exclusions applied to study design and publication type. RESULTS Amyloid plaques enriched with extracellular amyloid beta (Aβ) and intracellular neurofibrillary tangles comprised of hyperphosphorylated tau proteins are the two main pathological hallmarks of AD. Although the Aβ hypothesis has dominated AD research for many years, clinical Aβ-targeting strategies have consistently failed to effectively treat AD or prevent AD onset. The research focus in AD has recently shifted to the role of tau in AD. In addition to phosphorylation, tau is acetylated and proteolytically cleaved, which also contribute to its physiological and pathological functions. Emerging evidence characterizing pathological tau propagation and spreading provides new avenues for research into the molecular and cellular mechanisms underlying AD pathogenesis. Techniques to detect tau at minute levels in CSF and blood have been developed, and improved tracers have facilitated tau imaging in the brain. These advances have potential to accurately determine tau levels at early diagnostic stages in AD. Given that tau is a potential therapeutic target, anti-tau immunotherapy may potentially be a viable treatment strategy in AD intervention. CONCLUSION Detecting changes in tau and targeting tau pathology represent a promising lead in the diagnosis and treatment of AD.
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Affiliation(s)
- Xi-Lin Wu
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Juan Piña-Crespo
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiao-Chun Chen
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Hua-Xi Xu
- Neuroscience Initiative, Neuroscience and Aging Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
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19
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Merlo S, Spampinato SF, Sortino MA. Estrogen and Alzheimer's disease: Still an attractive topic despite disappointment from early clinical results. Eur J Pharmacol 2017; 817:51-58. [DOI: 10.1016/j.ejphar.2017.05.059] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/13/2017] [Accepted: 05/30/2017] [Indexed: 01/06/2023]
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20
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Moussa CEH. Beta-secretase inhibitors in phase I and phase II clinical trials for Alzheimer's disease. Expert Opin Investig Drugs 2017; 26:1131-1136. [PMID: 28817311 DOI: 10.1080/13543784.2017.1369527] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION BACE 1 is a protease that cleaves the transmembrane amyloid precursor protein and generates amyloid-β peptides that accumulate in AD brains. No known mutations are identified in the gene encoding BACE1 in AD. However, enzyme levels are elevated in AD and a single residue mutation in amyloid precursor protein protects against protein cleavage by BACE1, suggesting BACE involvement in disease pathogenesis. Drugs that can inhibit BACE1 would theoretically prevent Aβ accumulation and halt AD onset and progression. Areas covered: This review discusses clinical developments of BACE1 inhibitors and focuses on what is learned about these inhibitors as a potential treatment. Expert opinion: BACE1 inhibition as a therapeutic strategy to improve cognition in AD has been challening. Brain-penetrant BACE1 inhibitors have been developed and clinical trials are underway, both safety and efficacy are questionable. Several clinical trials suggest that BACE1 inhibition and other immunotherapies to reduce brain Aβ are insufficient to improve cognition in AD. This may be due to the emphasis on the amyloid hypothesis despite big failures. We may have to seriously consider shifting attention to therapeutic strategies other than BACE1 inhibition or reduction of Aβ alone and pay more attention to simultaneous clearance of tau and Aβ.
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Affiliation(s)
- Charbel E-H Moussa
- a Department of Neurology, Laboratory for Dementia and Parkinsonism, Translational Neurotherapeutics Program , Georgetown University Medical Center , Washington , DC , USA
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21
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Simvastatin ameliorate memory deficits and inflammation in clinical and mouse model of Alzheimer’s disease via modulating the expression of miR-106b. Biomed Pharmacother 2017; 92:46-57. [DOI: 10.1016/j.biopha.2017.05.060] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 12/16/2022] Open
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22
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Xia C, Dickerson BC. Multimodal PET Imaging of Amyloid and Tau Pathology in Alzheimer Disease and Non-Alzheimer Disease Dementias. PET Clin 2017; 12:351-359. [PMID: 28576172 PMCID: PMC5690983 DOI: 10.1016/j.cpet.2017.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Biomarkers of the molecular pathology underpinning dementia syndromes are increasingly recognized as crucial for diagnosis and development of disease-modifying treatments. Amyloid PET imaging is an integral part of the diagnostic assessment of Alzheimer disease. Its use has also deepened understanding of the role of amyloid pathology in Lewy body disorders and aging. Tau PET imaging is an imaging biomarker that will likely play an important role in the diagnosis, monitoring, and treatment in dementias. Using tau PET imaging to examine how tau pathology relates to amyloid and other markers of neurodegeneration will serve to better understand the pathophysiologic cascade that leads to dementia.
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Affiliation(s)
- Chenjie Xia
- Department of Neurology, Jewish General Hospital, McGill University, 3755 Chemin de la Côte-Sainte-Catherine Road, Suite E-005, Montreal, QC H3T 1E2, Canada
| | - Bradford C Dickerson
- Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital, Harvard University, 149 13th Street, Suite 2691, Charlestown, Boston, MA 02129, USA.
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Gordon BA, Blazey T, Su Y, Fagan AM, Holtzman DM, Morris JC, Benzinger TLS. Longitudinal β-Amyloid Deposition and Hippocampal Volume in Preclinical Alzheimer Disease and Suspected Non-Alzheimer Disease Pathophysiology. JAMA Neurol 2017; 73:1192-1200. [PMID: 27548756 DOI: 10.1001/jamaneurol.2016.2642] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Importance Preclinical Alzheimer disease (AD) can be staged using a 2-factor model denoting the presence or absence of β-amyloid (Aβ+/-) and neurodegeneration (ND+/-). The association of these stages with longitudinal biomarker outcomes is unknown. Objective To examine whether longitudinal Aβ accumulation and hippocampal atrophy differ based on initial preclinical staging. Design, Setting, and Participants This longitudinal population-based cohort study used data collected at the Knight Alzheimer Disease Research Center, Washington University, St Louis, Missouri, from December 1, 2006, to June 31, 2015. Cognitively normal older adults (n = 174) were recruited from the longitudinal Adult Children Study and Healthy Aging and Senile Dementia Study at the Knight Alzheimer Disease Research Center. At baseline, all participants had magnetic resonance imaging (MRI) scans, positron emission tomography (PET) scans with carbon 11-labeled Pittsburgh Compound B (PiB), and cerebrospinal fluid assays of tau and phosphorylated tau (ptau) acquired within 12 months. Using the baseline biomarkers, individuals were classified into preclinical stage 0 (Aβ-/ND-), 1 (Aβ+/ND-), or 2+ (Aβ+/ND+) or suspected non-AD pathophysiology (SNAP; Aβ-/ND+). Main Outcomes and Measures Subsequent longitudinal accumulation of Aβ assessed with PiB PET and loss of hippocampal volume assessed with MRI in each group. Results Among the 174 participants (81 men [46.6%]; 93 women [53.4%]; mean [SD] age, 65.7 [8.9] years), a proportion (14%-17%) of individuals with neurodegeneration alone (SNAP) later demonstrated Aβ+. The rates of Aβ accumulation and loss of hippocampal volume in individuals with SNAP were indistinguishable from those without any pathologic features at baseline (for Aβ accumulation: when hippocampal volume was used to define ND, t = 0.00 [P > .99]; when tau and ptau were used to define ND, t = -0.02 [P = .98]; for loss of hippocampal volume: when hippocampal volume was used to define ND, t = -1.34 [P = .18]; when tau and ptau were used to define ND, t = 0.84 [P = .40]). Later preclinical stages (stages 1 and 2+) had elevated Aβ accumulation. Using hippocampal volume to define ND, individuals with stage 1 had accelerated Aβ accumulation relative to stage 0 (t = 11.06; P < .001), stage 2+ (t = 2.10; P = .04), and SNAP (t = 9.32; P < .001), and those with stage 2+ had accelerated Aβ accumulation relative to stage 0 (t = 4.38; P < .001) and SNAP (t = 4.08; P < .001). When ND was defined using tau and ptau, individuals with stage 2+ had accelerated Aβ accumulation relative to stage 0 (t = 4.96) and SNAP (t = 4.06), and those with stage 1 had accelerated Aβ accumulation relative to stage 0 (t = 8.44) and SNAP (t = 6.61) (P < .001 for all comparisons). When ND was defined using cerebrospinal fluid biomarkers, individuals with stage 2+ had accelerated hippocampal atrophy relative to stage 0 (t = -3.41; P < .001), stage 1 (t = -2.48; P = .03), and SNAP (t = -2.26; P = .03). Conclusions and Relevance More advanced preclinical stages of AD have greater longitudinal Aβ accumulation. SNAP appears most likely to capture inherent individual variability in brain structure or to represent comorbid pathologic features rather than early emerging AD. Low hippocampal volumes or elevated levels of tau or ptau in isolation may not accurately represent ongoing neurodegenerative processes.
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Affiliation(s)
- Brian A Gordon
- Department of Radiology, Washington University, St Louis, Missouri2Knight Alzheimer's Disease Research Center, Washington University, St Louis, Missouri
| | - Tyler Blazey
- Division of Biology and Biomedical Sciences, Washington University, St Louis, Missouri
| | - Yi Su
- Department of Radiology, Washington University, St Louis, Missouri
| | - Anne M Fagan
- Knight Alzheimer's Disease Research Center, Washington University, St Louis, Missouri4Department of Neurology, Washington University, St Louis, Missouri5Hope Center for Neurological Disorders, Washington University, St Louis, Missouri
| | - David M Holtzman
- Knight Alzheimer's Disease Research Center, Washington University, St Louis, Missouri3Division of Biology and Biomedical Sciences, Washington University, St Louis, Missouri4Department of Neurology, Washington University, St Louis, Missouri5Hope Center for Neurological Disorders, Washington University, St Louis, Missouri
| | - John C Morris
- Knight Alzheimer's Disease Research Center, Washington University, St Louis, Missouri4Department of Neurology, Washington University, St Louis, Missouri
| | - Tammie L S Benzinger
- Department of Radiology, Washington University, St Louis, Missouri2Knight Alzheimer's Disease Research Center, Washington University, St Louis, Missouri6Department of Neurological Surgery, Washington University, St Louis, Missouri
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Zamolodchikov D, Strickland S. A possible new role for Aβ in vascular and inflammatory dysfunction in Alzheimer's disease. Thromb Res 2017; 141 Suppl 2:S59-61. [PMID: 27207427 DOI: 10.1016/s0049-3848(16)30367-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is often characterized by vascular pathology, a procoagulant state, and chronic inflammation. The mechanisms behind these abnormalities in AD are not clear. Here, we review evidence for the role of the AD-associated peptide Aβ in promoting inflammation and thrombosis in AD via its interaction with the circulating proteins factor XII and fibrinogen.
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Affiliation(s)
- Daria Zamolodchikov
- Laboratory of Neurobiology and Genetics; The Rockefeller University; New York, NY 10065, USA
| | - Sidney Strickland
- Laboratory of Neurobiology and Genetics; The Rockefeller University; New York, NY 10065, USA.
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Bell SP, Liu D, Samuels LR, Saraf AA, Gifford KA, Hohman TJ, Jefferson AL. Late-Life Body Mass Index, Rapid Weight Loss, Apolipoprotein E ε4 and the Risk of Cognitive Decline and Incident Dementia. J Nutr Health Aging 2017; 21:1259-1267. [PMID: 29188888 PMCID: PMC5736008 DOI: 10.1007/s12603-017-0906-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To examine the effect of late-life body mass index (BMI) and rapid weight loss on incident mild cognitive impairment (MCI) and Alzheimer's disease (AD). DESIGN Prospective longitudinal cohort study. SETTING National Alzheimer's Coordinating Center (NACC) Uniform Data Set, including 34 past and current National Institute on Aging-funded AD Centers across the United States. PARTICIPANTS 6940 older adults (n=5061 normal cognition [NC]; n=1879 MCI). MEASUREMENTS BMI (kg/m2) and modified Framingham Stroke Risk Profile (FSRP) score (sex, age, systolic blood pressure, anti-hypertension medication, diabetes mellitus, cigarette smoking, prevalent cardiovascular disease, atrial fibrillation) were assessed at baseline. Cognition and weight were assessed annually. RESULTS Multivariable binary logistic regression, adjusting for age, sex, race, education, length of follow-up, and modified FSRP related late-life BMI to risk of diagnostic conversion from NC to MCI or AD and from MCI to AD. Secondary analyses related late-life BMI to diagnostic conversion in the presence of rapid weight loss (>5% decrease in 12 months) and apolipoprotein E (APOE) ε4. During a mean 3.8-year follow-up period, 12% of NC participants converted to MCI or AD and 49% of MCI participants converted to AD. Higher baseline BMI was associated with a reduced probability of diagnostic conversion, such that for each one-unit increase in baseline BMI there was a reduction in diagnostic conversion for both NC (OR=0.977, 95%CI 0.958-0.996, p=0.015) and MCI participants (OR=0.962, 95%CI 0.942-0.983, p<0.001). The protective effect of higher baseline BMI did not persist in the setting of rapid weight loss but did persist when adjusting for APOE ε4. CONCLUSIONS Higher late-life BMI is associated with a lower risk of incident MCI and AD but is not protective in the presence of rapid weight loss.
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Affiliation(s)
- Susan P. Bell
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Center for Quality Aging, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Dandan Liu
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN
| | - Lauren R. Samuels
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN
| | - Avantika A. Saraf
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Center for Quality Aging, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Katherine A. Gifford
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Timothy J. Hohman
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Angela L. Jefferson
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
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Lin N, Xiong LL, Zhang RP, Zheng H, Wang L, Qian ZY, Zhang P, Chen ZW, Gao FB, Wang TH. Injection of Aβ1-40 into hippocampus induced cognitive lesion associated with neuronal apoptosis and multiple gene expressions in the tree shrew. Apoptosis 2016; 21:621-40. [DOI: 10.1007/s10495-016-1227-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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27
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Jack CR, Knopman DS, Chételat G, Dickson D, Fagan AM, Frisoni GB, Jagust W, Mormino EC, Petersen RC, Sperling RA, van der Flier WM, Villemagne VL, Visser PJ, Vos SJB. Suspected non-Alzheimer disease pathophysiology--concept and controversy. Nat Rev Neurol 2016; 12:117-24. [PMID: 26782335 PMCID: PMC4784257 DOI: 10.1038/nrneurol.2015.251] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Suspected non-Alzheimer disease pathophysiology (SNAP) is a biomarker-based concept that applies to individuals with normal levels of amyloid-β biomarkers in the brain, but in whom biomarkers of neurodegeneration are abnormal. The term SNAP has been applied to clinically normal individuals (who do not meet criteria for either mild cognitive impairment or dementia) and to individuals with mild cognitive impairment, but is applicable to any amyloid-negative, neurodegeneration-positive individual regardless of clinical status, except when the pathology underlying neurodegeneration can be reliably inferred from the clinical presentation. SNAP is present in ∼23% of clinically normal individuals aged >65 years and in ∼25% of mildly cognitively impaired individuals. APOE*ε4 is underrepresented in individuals with SNAP compared with amyloid-positive individuals. Clinically normal and mildly impaired individuals with SNAP have worse clinical and/or cognitive outcomes than individuals with normal levels of neurodegeneration and amyloid-β biomarkers. In this Perspectives article, we describe the available data on SNAP and address topical controversies in the field.
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Affiliation(s)
- Clifford R Jack
- Department of Radiology, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - David S Knopman
- Department of Neurology, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Gaël Chételat
- INSERM, Université de Caen, EPHE, CHU de Caen, U1077, Caen, France
| | - Dennis Dickson
- Department of Pathology, Mayo Clinic and Foundation, 4500 San Pablo Road South, Jacksonville, Florida 32224, USA
| | - Anne M Fagan
- Department of Neurology, Knight Alzheimer's Disease Research Center, Washington University School of Medicine, 4488 Forest Park Avenue, Suite 101, St Louis, Missouri 63108, USA
| | - Giovanni B Frisoni
- University Hospitals and University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Genève, Switzerland
| | - William Jagust
- Helen Wills Neuroscience Institute, University of California Berkeley, 175 Li Ka Shing Center, Berkeley, California 94720, USA
| | - Elizabeth C Mormino
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115, USA
| | - Ronald C Petersen
- Department of Neurology, Mayo Clinic and Foundation, 200 First Street SW, Rochester, Minnesota 55905, USA
| | - Reisa A Sperling
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115, USA
| | - Wiesje M van der Flier
- Alzheimer Center, Department of Neurology, VU University Medical Center, Neuroscience Campus Amsterdam, PO Box 7057, 1007 MB Amsterdam, Netherlands
| | - Victor L Villemagne
- Department of Molecular Imaging &Therapy, Centre for PET, Austin Health, 145 Studley Road, PO Box 5555 Melbourne, Victoria, Australia 3084
| | - Pieter J Visser
- Department of Psychiatry and Neuropsychology, Institute of Mental Health and Neuroscience, Maastricht University, PO Box 616 MD Maastricht, Netherlands
| | - Stephanie J B Vos
- Department of Psychiatry and Neuropsychology, Institute of Mental Health and Neuroscience, Maastricht University, PO Box 616 MD Maastricht, Netherlands
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Eisenmenger LB, Huo EJ, Hoffman JM, Minoshima S, Matesan MC, Lewis DH, Lopresti BJ, Mathis CA, Okonkwo DO, Mountz JM. Advances in PET Imaging of Degenerative, Cerebrovascular, and Traumatic Causes of Dementia. Semin Nucl Med 2016; 46:57-87. [DOI: 10.1053/j.semnuclmed.2015.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Stuendl A, Kunadt M, Kruse N, Bartels C, Moebius W, Danzer KM, Mollenhauer B, Schneider A. Induction of α-synuclein aggregate formation by CSF exosomes from patients with Parkinson's disease and dementia with Lewy bodies. Brain 2015; 139:481-94. [PMID: 26647156 PMCID: PMC4805087 DOI: 10.1093/brain/awv346] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/09/2015] [Indexed: 11/14/2022] Open
Abstract
Extracellular α-synuclein has been proposed as a crucial mechanism for induction of pathological aggregate formation in previously healthy cells. In vitro, extracellular α-synuclein is partially associated with exosomal vesicles. Recently, we have provided evidence that exosomal α-synuclein is present in the central nervous system in vivo. We hypothesized that exosomal α-synuclein species from patients with α-synuclein related neurodegeneration serve as carriers for interneuronal disease transmission. We isolated exosomes from cerebrospinal fluid from patients with Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy as a non-α-synuclein related disorder that clinically overlaps with Parkinson's disease, and neurological controls. Cerebrospinal fluid exosome numbers, α-synuclein protein content of cerebrospinal fluid exosomes and their potential to induce oligomerization of α-synuclein were analysed. The quantification of cerebrospinal fluid exosomal α-synuclein showed distinct differences between patients with Parkinson's disease and dementia with Lewy bodies. In addition, exosomal α-synuclein levels correlated with the severity of cognitive impairment in cross-sectional samples from patients with dementia with Lewy bodies. Importantly, cerebrospinal fluid exosomes derived from Parkinson's disease and dementia with Lewy bodies induce oligomerization of α-synuclein in a reporter cell line in a dose-dependent manner. Our data suggest that cerebrospinal fluid exosomes from patients with Parkinson's disease and dementia with Lewy bodies contain a pathogenic species of α-synuclein, which could initiate oligomerization of soluble α-synuclein in target cells and confer disease pathology.
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Affiliation(s)
- Anne Stuendl
- 1 Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Von-Siebold-Str. 5, 37075 Göttingen, Germany 2 Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Marcel Kunadt
- 1 Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Von-Siebold-Str. 5, 37075 Göttingen, Germany 2 Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany 3 Cluster of Excellence 'Nanoscale Microscopy and Molecular Physiology of the Brain' (CNMPB), Göttingen, Germany
| | - Niels Kruse
- 4 Department of Neuropathology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Claudia Bartels
- 1 Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Wiebke Moebius
- 2 Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Karin M Danzer
- 5 Department of Neurology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Brit Mollenhauer
- 4 Department of Neuropathology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany 6 Paracelsus-Elena Klinik, Klinikstr. 16, 34128 Kassel, Germany
| | - Anja Schneider
- 1 Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Von-Siebold-Str. 5, 37075 Göttingen, Germany 2 Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany 3 Cluster of Excellence 'Nanoscale Microscopy and Molecular Physiology of the Brain' (CNMPB), Göttingen, Germany 7 German Centre for Neurodegenerative Diseases (DZNE), Göttingen, Von-Siebold-Str. 5, 37075 Göttingen, Germany
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Daneschvar HL, Aronson MD, Smetana GW. Do statins prevent Alzheimer's disease? A narrative review. Eur J Intern Med 2015; 26:666-9. [PMID: 26342722 DOI: 10.1016/j.ejim.2015.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 01/02/2023]
Abstract
Alzheimer's disease is the most common cause of dementia and occurs commonly in patients 65 and older. There is an urgent need to find an effective management that could help prevent or at least slow down the progress of this major public health problem. Cholesterol related pathways might play a role in the pathogenesis of Alzheimer's disease. Treatment with 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) has been suggested to promote the prevention of Alzheimer's disease. In this review, we discuss potential pathogenetic pathways for the development of Alzheimer's disease and review the evidence regarding the value of statins as a strategy to prevent or delay progression of Alzheimer's disease.
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Affiliation(s)
- Homayoun L Daneschvar
- Harvard Medical School, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center/Shapiro 621C, 330 Brookline Ave, Boston, MA 02215, United States.
| | - Mark D Aronson
- Harvard Medical School, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, MA, United States.
| | - Gerald W Smetana
- Harvard Medical School, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, MA, United States.
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Jack CR, Wiste HJ, Weigand SD, Knopman DS, Vemuri P, Mielke MM, Lowe V, Senjem ML, Gunter JL, Machulda MM, Gregg BE, Pankratz VS, Rocca WA, Petersen RC. Age, Sex, and APOE ε4 Effects on Memory, Brain Structure, and β-Amyloid Across the Adult Life Span. JAMA Neurol 2015; 72:511-9. [PMID: 25775353 DOI: 10.1001/jamaneurol.2014.4821] [Citation(s) in RCA: 278] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
IMPORTANCE Typical cognitive aging may be defined as age-associated changes in cognitive performance in individuals who remain free of dementia. Ideally, the full adult age spectrum should be included to assess brain imaging findings associated with typical aging. OBJECTIVE To compare age, sex, and APOE ε4 effects on memory, brain structure (adjusted hippocampal volume [HVa]), and amyloid positron emission tomography (PET) in cognitively normal individuals aged 30 to 95 years old. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional observational study (March 2006 to October 2014) at an academic medical center. We studied 1246 cognitively normal individuals, including 1209 participants aged 50 to 95 years old enrolled in a population-based study of cognitive aging and 37 self-selected volunteers aged 30 to 49 years old. MAIN OUTCOMES AND MEASURES Memory, HVa, and amyloid PET. RESULTS Overall, memory worsened from age 30 years through the 90s. The HVa worsened gradually from age 30 years to the mid-60s and more steeply beyond that age. The median amyloid PET was low until age 70 years and increased thereafter. Memory was worse in men than in women overall (P < .001) and more specifically beyond age 40 years. The HVa was lower in men than in women overall (P < .001) and more specifically beyond age 60 years. There was no sex difference in amyloid PET at any age. Within each sex, memory performance and HVa were not different by APOE ε4 status at any age. From age 70 years onward, APOE ε4 carriers had significantly greater median amyloid PET than noncarriers. However, the ages at which 10% of the population were amyloid PET positive were 57 years for APOE ε4 carriers and 64 years for noncarriers. CONCLUSIONS AND RELEVANCE Male sex is associated with worse memory and HVa among cognitively normal individuals, while APOE ε4 is not. In contrast, APOE ε4 is associated with greater amyloid PET (from age 70 years onward), while sex is not. Worsening memory and HVa occur at earlier ages than abnormal amyloid PET. Therefore, neuropathological processes other than β-amyloidosis must underlie declines in brain structure and memory function in middle age. Our findings are consistent with a model of late-onset Alzheimer disease in which β-amyloidosis arises in later life on a background of preexisting structural and cognitive decline that is associated with aging and not with β-amyloid deposits.
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Affiliation(s)
- Clifford R Jack
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Heather J Wiste
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Stephen D Weigand
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota
| | - David S Knopman
- Department of Neurology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Prashanthi Vemuri
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Michelle M Mielke
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Val Lowe
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Matthew L Senjem
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Jeffrey L Gunter
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Mary M Machulda
- Department of Psychiatry and Psychology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Brian E Gregg
- Department of Radiology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - V Shane Pankratz
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Walter A Rocca
- Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, Minnesota3Department of Neurology, Mayo Clinic and Foundation, Rochester, Minnesota
| | - Ronald C Petersen
- Department of Neurology, Mayo Clinic and Foundation, Rochester, Minnesota
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Hake A, Trzepacz PT, Wang S, Yu P, Case M, Hochstetler H, Witte MM, Degenhardt EK, Dean RA. Florbetapir positron emission tomography and cerebrospinal fluid biomarkers. Alzheimers Dement 2015; 11:986-93. [PMID: 25916563 DOI: 10.1016/j.jalz.2015.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 01/16/2015] [Accepted: 03/06/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND We evaluated the relationship between florbetapir-F18 positron emission tomography (FBP PET) and cerebrospinal fluid (CSF) biomarkers. METHODS Alzheimer's Disease Neuroimaging Initiative-Grand Opportunity and Alzheimer's Disease Neuroimaging Initiative 2 (GO/2) healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) dementia subjects with clinical measures and CSF collected ±90 days of FBP PET data were analyzed using correlation and logistic regression. RESULTS In HC and MCI subjects, FBP PET anterior and posterior cingulate and composite standard uptake value ratios correlated with CSF amyloid beta (Aβ1-42) and tau/Aβ1-42 ratios. Using logistic regression, Aβ1-42, total tau (t-tau), phosphorylated tau181P (p-tau), and FBP PET composite each differentiated HC versus AD. Aβ1-42 and t-tau distinguished MCI versus AD, without additional contribution by FBP PET. Total tau and p-tau added discriminative power to FBP PET when classifying HC versus AD. CONCLUSION Based on cross-sectional diagnostic groups, both amyloid and tau measures distinguish healthy from demented subjects. Longitudinal analyses are needed.
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Affiliation(s)
- Ann Hake
- Eli Lilly and Company, Indianapolis, IN, USA; Department of Neurology Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Paula T Trzepacz
- Eli Lilly and Company, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Peng Yu
- Eli Lilly and Company, Indianapolis, IN, USA
| | | | | | | | - Elisabeth K Degenhardt
- Eli Lilly and Company, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana University Health Physicians Group, Indiana University Health, Indianapolis, IN, USA
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Activation of the factor XII-driven contact system in Alzheimer's disease patient and mouse model plasma. Proc Natl Acad Sci U S A 2015; 112:4068-73. [PMID: 25775543 DOI: 10.1073/pnas.1423764112] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by accumulation of the β-amyloid peptide (Aβ), which likely contributes to disease via multiple mechanisms. Increasing evidence implicates inflammation in AD, the origins of which are not completely understood. We investigated whether circulating Aβ could initiate inflammation in AD via the plasma contact activation system. This proteolytic cascade is triggered by the activation of the plasma protein factor XII (FXII) and leads to kallikrein-mediated cleavage of high molecular-weight kininogen (HK) and release of proinflammatory bradykinin. Aβ has been shown to promote FXII-dependent cleavage of HK in vitro. In addition, increased cleavage of HK has been found in the cerebrospinal fluid of patients with AD. Here, we show increased activation of FXII, kallikrein activity, and HK cleavage in AD patient plasma. Increased contact system activation is also observed in AD mouse model plasma and in plasma from wild-type mice i.v. injected with Aβ42. Our results demonstrate that Aβ42-mediated contact system activation can occur in the AD circulation and suggest new pathogenic mechanisms, diagnostic tests, and therapies for AD.
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Bajda M, Filipek S. Study of early stages of amyloid Aβ13-23 formation using molecular dynamics simulation in implicit environments. Comput Biol Chem 2015; 56:13-8. [PMID: 25749181 DOI: 10.1016/j.compbiolchem.2015.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 02/09/2015] [Accepted: 02/21/2015] [Indexed: 02/07/2023]
Abstract
β-amyloid aggregation and formation of senile plaques is one of the hallmarks of Alzheimer's disease (AD). It leads to degeneration of neurons and decline of cognitive functions. The most aggregative and toxic form of β-amyloid is Aβ1-42 but in experiments, the shorter forms able to form aggregates are also used. The early stages of amyloid formation are of special interest due to the influence of this peptide on progression of AD. Here, we employed nine helices of undecapeptide Aβ13-23 and studied progress of amyloid formation using 500ns molecular dynamics simulation and implicit membrane environment. The small β-sheets emerged very early during simulation as separated two-strand structures and a presence of the membrane facilitated this process. Later, the larger β-sheets were formed. However, the ninth helix which did not form paired structure stayed unchanged till the end of MD simulation. Paired helix-helix interactions seemed to be a driving force of β-sheet formation at early stages of amyloid formation. Contrary, the specific interactions between α-helix and β-sheet can be very stable and be stabilized by the membrane.
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Affiliation(s)
- Marek Bajda
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Medical College, Jagiellonian University, Medyczna 9, 30-688 Cracow, Poland.
| | - Slawomir Filipek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
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Abstract
β-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the β-secretase enzyme required for the production of the neurotoxic β-amyloid (Aβ) peptide that is widely considered to have a crucial early role in the etiology of Alzheimer’s disease (AD). As a result, BACE1 has emerged as a prime drug target for reducing the levels of Aβ in the AD brain, and the development of BACE1 inhibitors as therapeutic agents is being vigorously pursued. It has proven difficult for the pharmaceutical industry to design BACE1 inhibitor drugs that pass the blood–brain barrier, however this challenge has recently been met and BACE1 inhibitors are now in human clinical trials to test for safety and efficacy in AD patients and individuals with pre-symptomatic AD. Initial results suggest that some of these BACE1 inhibitor drugs are well tolerated, although others have dropped out because of toxicity and it is still too early to know whether any will be effective for the prevention or treatment of AD. Additionally, based on newly identified BACE1 substrates and phenotypes of mice that lack BACE1, concerns have emerged about potential mechanism-based side effects of BACE1 inhibitor drugs with chronic administration. It is hoped that a therapeutic window can be achieved that balances safety and efficacy. This review summarizes the current state of progress in the development of BACE1 inhibitor drugs and the evaluation of their therapeutic potential for AD.
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36
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Opportunities and Limitations of Modelling Alzheimer's Disease with Induced Pluripotent Stem Cells. J Clin Med 2014; 3:1357-72. [PMID: 26237606 PMCID: PMC4470188 DOI: 10.3390/jcm3041357] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/31/2014] [Accepted: 11/12/2014] [Indexed: 01/16/2023] Open
Abstract
Reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) has opened the way for patient-specific disease modelling. Following their differentiation into neuronal cell types, iPSC have enabled the investigation of human neurodegenerative diseases, such as Alzheimer's disease (AD). While human iPSCs certainly provide great opportunities to repeatedly interrogate specific human brain cell types of individuals with familial and sporadic forms of the disease, the complex aetiology and timescale over which AD develops in humans poses particular challenges to iPSC-based AD models. Here, we discuss the current state-of-play in the context of these and other iPSC model-related challenges and elaborate on likely future developments in this field of research.
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Affiliation(s)
- Clifford R Jack
- Department of Radiology, Mayo Clinic and Foundation, 200 First Street SW, Rochester, MN, 55905, USA,
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Stancu IC, Vasconcelos B, Terwel D, Dewachter I. Models of β-amyloid induced Tau-pathology: the long and "folded" road to understand the mechanism. Mol Neurodegener 2014; 9:51. [PMID: 25407337 PMCID: PMC4255655 DOI: 10.1186/1750-1326-9-51] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 10/14/2014] [Indexed: 02/28/2023] Open
Abstract
The amyloid cascade hypothesis has been the prevailing hypothesis in Alzheimer’s Disease research, although the final and most wanted proof i.e. fully successful anti-amyloid clinical trials in patients, is still lacking. This may require a better in depth understanding of the cascade. Particularly, the exact toxic forms of Aβ and Tau, the molecular link between them and their respective contributions to the disease process need to be identified in detail. Although the lack of final proof has raised substantial criticism on the hypothesis per se, accumulating experimental evidence in in vitro models, in vivo models and from biomarkers analysis in patients supports the amyloid cascade and particularly Aβ-induced Tau-pathology, which is the focus of this review. We here discuss available models that recapitulate Aβ-induced Tau-pathology and review some potential underlying mechanisms. The availability and diversity of these models that mimic the amyloid cascade partially or more complete, provide tools to study remaining questions, which are crucial for development of therapeutic strategies for Alzheimer’s Disease.
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Affiliation(s)
| | | | | | - Ilse Dewachter
- Catholic University of Louvain, Institute of Neuroscience, Alzheimer Dementia, Av, E, Mounier 53, Av, Hippocrate 54, B-1200 Brussels, Belgium.
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Maternal immune activation and abnormal brain development across CNS disorders. Nat Rev Neurol 2014; 10:643-60. [PMID: 25311587 DOI: 10.1038/nrneurol.2014.187] [Citation(s) in RCA: 595] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Epidemiological studies have shown a clear association between maternal infection and schizophrenia or autism in the progeny. Animal models have revealed maternal immune activation (mIA) to be a profound risk factor for neurochemical and behavioural abnormalities in the offspring. Microglial priming has been proposed as a major consequence of mIA, and represents a critical link in a causal chain that leads to the wide spectrum of neuronal dysfunctions and behavioural phenotypes observed in the juvenile, adult or aged offspring. Such diversity of phenotypic outcomes in the mIA model are mirrored by recent clinical evidence suggesting that infectious exposure during pregnancy is also associated with epilepsy and, to a lesser extent, cerebral palsy in children. Preclinical research also suggests that mIA might precipitate the development of Alzheimer and Parkinson diseases. Here, we summarize and critically review the emerging evidence that mIA is a shared environmental risk factor across CNS disorders that varies as a function of interactions between genetic and additional environmental factors. We also review ongoing clinical trials targeting immune pathways affected by mIA that may play a part in disease manifestation. In addition, future directions and outstanding questions are discussed, including potential symptomatic, disease-modifying and preventive treatment strategies.
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Insulin resistance in Alzheimer's disease. Neurobiol Dis 2014; 72 Pt A:92-103. [PMID: 25237037 DOI: 10.1016/j.nbd.2014.09.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 09/02/2014] [Accepted: 09/05/2014] [Indexed: 12/16/2022] Open
Abstract
Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD.
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Rafael H. Omental transplantation for neurodegenerative diseases. AMERICAN JOURNAL OF NEURODEGENERATIVE DISEASE 2014; 3:50-63. [PMID: 25232510 PMCID: PMC4162586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 08/03/2014] [Indexed: 06/03/2023]
Abstract
Up to date, almost all researchers consider that there is still no effective therapy for neurodegenerative diseases (NDDs) and therefore, these diseases are incurable. However, since May 1998, we know that a progressive ischemia in the medial temporal lobes and subcommissural regions can cause Alzheimer's disease; because, in contrast to this, its revascularization by means of omental tissue can cure or improve this disease. Likewise we observed that the aging process, Huntington's disease, Parkinson's disease, and Amyotrophic lateral sclerosis; all of them are of ischemic origin caused by cerebral atherosclerosis, associated with vascular anomalies and/or environmental chemicals. On the contrary, an omental transplantation on the affected zone can stop and improve these diseases. For these reasons, I believe that NDDs, are wrongly classified as neurodegenerative disorders.
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Fonteh AN, Cipolla M, Chiang J, Arakaki X, Harrington MG. Human cerebrospinal fluid fatty acid levels differ between supernatant fluid and brain-derived nanoparticle fractions, and are altered in Alzheimer's disease. PLoS One 2014; 9:e100519. [PMID: 24956173 PMCID: PMC4067345 DOI: 10.1371/journal.pone.0100519] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 05/28/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Although saturated (SAFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids are important structural components of neuronal membranes and precursors of signaling molecules, knowledge of their metabolism in Alzheimer's disease (AD) is limited. Based on recent discovery that lipids in cerebrospinal fluid (CSF) are distributed in both brain-derived nanoparticles (NP) and supernatant fluid (SF), we hypothesized that fatty acid (FA) abundance and distribution into these compartments is altered in early AD pathology. METHODOLOGY AND FINDINGS We assayed the FA composition and abundance in CSF fractions from cognitively healthy (CH), mild cognitive impairment (MCI), and AD study participants using gas chromatography-mass spectrometry. In the SF fraction, concentration of docosahexaenoic acid [DHA, (C22:6n-3)] was less in AD compared with CH, while alpha linolenic acid [α-LNA, (C18:3n-3)] was lower in MCI compared with CH. In the NP fraction, levels of SAFAs (C15:0, C16:0) and a MUFA (C15:1) differentiated CH from MCI, while two MUFAs (C15:1, C19:1) and four PUFAs (C20:2n-6, C20:3n-3, C22:4n-6, C22:5n-3) were higher in AD compared with CH. Levels of even-chain free SAFA and total free FA levels were higher in AD, levels of odd-chain free SAFAs, MUFAs, n-3 PUFAs, and total PUFA, were lower in AD compared with CH. Free n-6 PUFA levels were similar in all three groups. CONCLUSIONS AND SIGNIFICANCE FA metabolism is compartmentalized differently in NP versus SF fractions of CSF, and altered FA levels reflect the importance of abnormal metabolism and oxidative pathways in AD. Depleted DHA in CSF fractions in AD is consistent with the importance of n-3 PUFAs in cognitive function, and suggests that disturbed PUFA metabolism contributes to AD pathology. This study of FA levels in CSF fractions from different cognitive stages shows potential AD biomarkers, and provides further insight into cell membrane dysfunctions, including mechanisms leading to amyloid production.
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Affiliation(s)
- Alfred N. Fonteh
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, California, United States of America
| | - Matthew Cipolla
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, California, United States of America
| | - Jiarong Chiang
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, California, United States of America
| | - Xianghong Arakaki
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, California, United States of America
| | - Michael G. Harrington
- Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, California, United States of America
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Dal Prà I, Chiarini A, Gui L, Chakravarthy B, Pacchiana R, Gardenal E, Whitfield JF, Armato U. Do astrocytes collaborate with neurons in spreading the "infectious" aβ and Tau drivers of Alzheimer's disease? Neuroscientist 2014; 21:9-29. [PMID: 24740577 DOI: 10.1177/1073858414529828] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Evidence has begun emerging for the "contagious" and destructive Aβ42 (amyloid-beta42) oligomers and phosphorylated Tau oligomers as drivers of sporadic Alzheimer's disease (AD), which advances along a pathway starting from the brainstem or entorhinal cortex and leading to cognition-related upper cerebral cortex regions. Seemingly, Aβ42 oligomers trigger the events generating the neurotoxic Tau oligomers, which may even by themselves spread the characteristic AD neuropathology. It has been assumed that only neurons make and spread these toxic drivers, whereas their associated astrocytes are just janitorial bystanders/scavengers. But this view is likely to radically change since normal human astrocytes freshly isolated from adult cerebral cortex can be induced by exogenous Aβ25-35, an Aβ42 proxy, to make and secrete increased amounts of endogenous Aβ42. Thus, it would seem that the steady slow progression of AD neuropathology along specific cognition-relevant brain networks is driven by both Aβ42 and phosphorylated Tau oligomers that are variously released from increasing numbers of "contagion-stricken" members of tightly coupled neuron-astrocyte teams. Hence, we surmise that stopping the oversecretion and spread of the two kinds of "contagious" oligomers by such team members, perhaps via a specific CaSR (Ca(2+)-sensing receptor) antagonist like NPS 2143, might effectively treat AD.
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Affiliation(s)
- Ilaria Dal Prà
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Anna Chiarini
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Li Gui
- Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, China
| | | | - Raffaella Pacchiana
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | - Emanuela Gardenal
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
| | | | - Ubaldo Armato
- Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy
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Fan LY, Chiu MJ. Combotherapy and current concepts as well as future strategies for the treatment of Alzheimer's disease. Neuropsychiatr Dis Treat 2014; 10:439-51. [PMID: 24648738 PMCID: PMC3956689 DOI: 10.2147/ndt.s45143] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
It has been estimated that 35.6 million people globally had dementia in 2010 and the prevalence of dementia has been predicted to double every 20 years. Thus, 115.4 million people may be living with dementia in 2050. Alzheimer's disease (AD) is the leading cause of dementia and is present in 60%-70% of people with dementia. Unfortunately, there are few approved drugs that can alleviate the cognitive or behavioral symptoms of AD dementia. Recent studies have revealed that pathophysiological changes related to AD occur decades before the appearance of clinical symptoms of dementia. This extended preclinical phase of AD provides a critical chance for disease-modifying agents to halt or delay the relentless process of AD. Although several trials targeting various pathological processes are ongoing, the examination of the combined use of different approaches to combat AD seems warranted. In this article, we will review current therapies, future strategies, and ongoing clinical trials for the treatment of AD with a special focus on combination therapies. Furthermore, preventive strategies for cognitively normal subjects in the presymptomatic stages of AD will also be addressed. In this review, we discuss current hypotheses of the disease process. In the decades since the approval of cholinesterase inhibitors, no new drug has ultimately demonstrated clear success in clinical trials. Given the difficulties that have been encountered in attempts to identify a single drug that can treat AD, we must pursue effective multi-target strategies, ie, combination therapies. The combination of cholinesterase inhibitors and memantine is considered well tolerated and safe, and this combination benefits patients with moderate-to-severe AD. In contrast, with the exception of adjuvant therapies of conventional drugs, combinations of different disease-modifying agents with different mechanisms may have promising synergic effects and benefit cognition, behavior, and daily living function.
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Affiliation(s)
- Ling-Yun Fan
- Department of Neurology, En Chu Kong Hospital, Taipei, Taiwan
- Department of Neurology, College of Medicine, Graduate Institute of Brain and Mind Sciences, Taipei, Taiwan
| | - Ming-Jang Chiu
- Department of Neurology, College of Medicine, Graduate Institute of Brain and Mind Sciences, Taipei, Taiwan
- Graduate Institute of Psychology, National Taiwan University Hospital, Taipei, Taiwan
- Graduate Institute of Biomedical Engineering and Bioinformatics, National Taiwan University Hospital, Taipei, Taiwan
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45
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Abstract
The β secretase, widely known as β-site amyloid precursor protein cleaving enzyme 1 (BACE1), initiates the production of the toxic amyloid β (Aβ) that plays a crucial early part in Alzheimer's disease pathogenesis. BACE1 is a prime therapeutic target for lowering cerebral Aβ concentrations in Alzheimer's disease, and clinical development of BACE1 inhibitors is being intensely pursued. Although BACE1 inhibitor drug development has proven challenging, several promising BACE1 inhibitors have recently entered human clinical trials. The safety and efficacy of these drugs are being tested at present in healthy individuals and patients with Alzheimer's disease, and will soon be tested in individuals with presymptomatic Alzheimer's disease. Although hopes are high that BACE1 inhibitors might be efficacious for the prevention or treatment of Alzheimer's disease, concerns have been raised about potential mechanism-based side-effects of these drugs. The potential of therapeutic BACE1 inhibition might prove to be a watershed in the treatment of Alzheimer's disease.
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Affiliation(s)
- Riqiang Yan
- Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Robert Vassar
- Department of Cell and Molecular Biology, The Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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Muratore CR, Rice HC, Srikanth P, Callahan DG, Shin T, Benjamin LNP, Walsh DM, Selkoe DJ, Young-Pearse TL. The familial Alzheimer's disease APPV717I mutation alters APP processing and Tau expression in iPSC-derived neurons. Hum Mol Genet 2014; 23:3523-36. [PMID: 24524897 DOI: 10.1093/hmg/ddu064] [Citation(s) in RCA: 267] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by extracellular plaques containing amyloid β (Aβ)-protein and intracellular tangles containing hyperphosphorylated Tau protein. Here, we describe the generation of inducible pluripotent stem cell lines from patients harboring the London familial AD (fAD) amyloid precursor protein (APP) mutation (V717I). We examine AD-relevant phenotypes following directed differentiation to forebrain neuronal fates vulnerable in AD. We observe that over differentiation time to mature neuronal fates, APP expression and levels of Aβ increase dramatically. In both immature and mature neuronal fates, the APPV717I mutation affects both β- and γ-secretase cleavage of APP. Although the mutation lies near the γ-secretase cleavage site in the transmembrane domain of APP, we find that β-secretase cleavage of APP is elevated leading to generation of increased levels of both APPsβ and Aβ. Furthermore, we find that this mutation alters the initial cleavage site of γ-secretase, resulting in an increased generation of both Aβ42 and Aβ38. In addition to altered APP processing, an increase in levels of total and phosphorylated Tau is observed in neurons with the APPV717I mutation. We show that treatment with Aβ-specific antibodies early in culture reverses the phenotype of increased total Tau levels, implicating altered Aβ production in fAD neurons in this phenotype. These studies use human neurons to reveal previously unrecognized effects of the most common fAD APP mutation and provide a model system for testing therapeutic strategies in the cell types most relevant to disease processes.
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Affiliation(s)
- Christina R Muratore
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Heather C Rice
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Priya Srikanth
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Dana G Callahan
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Taehwan Shin
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Lawrence N P Benjamin
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Dominic M Walsh
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Dennis J Selkoe
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Tracy L Young-Pearse
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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Yue F, Lu C, Ai Y, Chan P, Zhang Z. Age-associated changes of cerebrospinal fluid amyloid-β and tau in cynomolgus monkeys. Neurobiol Aging 2014; 35:1656-9. [PMID: 24581480 DOI: 10.1016/j.neurobiolaging.2014.01.139] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
Nonhuman primates (NHPs) are useful for the study of age-associated changes in the brain as a model that is biologically closely related to humans. For example, with age, all NHPs analyzed to date, develop β-amyloid (Aβ) plaques as seen in humans. Nevertheless, it is still unclear if NHPs have human-like age-associated changes in Aβ and tau protein in cerebrospinal fluid. The present study was an attempt to specifically address these issues. Cerebrospinal fluid levels of Aβ and phosphorylated tau were measured in 37 and 22 cynomolgus monkeys, respectively, with ages ranging from 4 to 22-year-old. The result from the present study revealed significant age-associated declines in Aβ42 levels but not in Aβ40 and phosphorylated tau levels. This finding appears to parallel changes seen with human aging, in which decreased levels of Aβ42 can be seen in normal older adults, and supporting that cynomolgus monkeys would be a useful model for studying age-related neurologic disorders associated with Alzheimer-like cerebral proteopathy.
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Affiliation(s)
- Feng Yue
- Department of Neurobiology Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China; Key Laboratory on Neurodegenerative Disease of Ministry of Education and Key Laboratory on Parkinson's Disease of Beijing, Beijing, China
| | - Chunling Lu
- WinconTheraCells Biotechnologies Co, LTD, Nanning, Guangxi, China
| | - Yi Ai
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Piu Chan
- Department of Neurobiology Beijing Institute of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China; Key Laboratory on Neurodegenerative Disease of Ministry of Education and Key Laboratory on Parkinson's Disease of Beijing, Beijing, China
| | - Zhiming Zhang
- Department of Anatomy and Neurobiology, University of Kentucky College of Medicine, Lexington, KY, USA.
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D-polyglutamine amyloid recruits L-polyglutamine monomers and kills cells. J Mol Biol 2013; 426:816-29. [PMID: 24291210 DOI: 10.1016/j.jmb.2013.11.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 10/21/2013] [Accepted: 11/15/2013] [Indexed: 11/23/2022]
Abstract
Polyglutamine (polyQ) amyloid fibrils are observed in disease tissue and have been implicated as toxic agents responsible for neurodegeneration in expanded CAG repeat diseases such as Huntington's disease. Despite intensive efforts, the mechanism of amyloid toxicity remains unknown. As a novel approach to probing polyQ toxicity, we investigate here how some cellular and physical properties of polyQ amyloid vary with the chirality of the glutamine residues in the polyQ. We challenged PC12 cells with small amyloid fibrils composed of either L- or D-polyQ peptides and found that D-fibrils are as cytotoxic as L-fibrils. We also found using fluorescence microscopy that both aggregates effectively seed the aggregation of cell-produced L-polyQ proteins, suggesting a surprising lack of stereochemical restriction in seeded elongation of polyQ amyloid. To investigate this effect further, we studied chemically synthesized D- and L-polyQ in vitro. We found that, as expected, D-polyQ monomers are not recognized by proteins that recognize L-polyQ monomers. However, amyloid fibrils prepared from D-polyQ peptides can efficiently seed the aggregation of L-polyQ monomers in vitro, and vice versa. This result is consistent with our cell results on polyQ recruitment but is inconsistent with previous literature reports on the chiral specificity of amyloid seeding. This chiral cross-seeding can be rationalized by a model for seeded elongation featuring a "rippled β-sheet" interface between seed fibril and docked monomers of opposite chirality. The lack of chiral discrimination in polyQ amyloid cytotoxicity is consistent with several toxicity mechanisms, including recruitment of cellular polyQ proteins.
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Knopman DS, Jack CR, Wiste HJ, Weigand SD, Vemuri P, Lowe VJ, Kantarci K, Gunter JL, Senjem ML, Mielke MM, Roberts RO, Boeve BF, Petersen RC. Selective worsening of brain injury biomarker abnormalities in cognitively normal elderly persons with β-amyloidosis. JAMA Neurol 2013; 70:1030-8. [PMID: 23797806 DOI: 10.1001/jamaneurol.2013.182] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
IMPORTANCE The appearance of β-amyloidosis and brain injury biomarkers in cognitively normal (CN) persons is thought to define risk for the future development of cognitive impairment due to Alzheimer disease (AD), but their interaction is poorly understood. OBJECTIVE To test the hypothesis that the joint presence of β-amyloidosis and brain injury biomarkers would lead to more rapid neurodegeneration. DESIGN Longitudinal cohort study. SETTING Population-based Mayo Clinic Study of Aging. PARTICIPANTS One hundred ninety-one CN persons (median age, 77 years; range, 71-93 years) in the Mayo Clinic Study of Aging who underwent magnetic resonance, fludeoxyglucose F 18 (FDG) positron emission tomography (PET), and Pittsburgh Compound B (PiB) PET imaging at least twice 15 months apart. Participants were grouped according to the recommendations of the National Institute on Aging-Alzheimer Association preclinical AD criteria based on the presence of β-amyloidosis, defined as a PiB PET standardized uptake value ratio (SUVr) greater than 1.5, alone (stage 1) or with brain injury (stage 2 + 3), defined as hippocampal atrophy or FDG hypometabolism. We also studied a group of patients with mild cognitive impairment (n = 17) or dementia (n = 9) from the Mayo Clinic Study of Aging or the Mayo Alzheimer Center with similar follow-up times who had undergone comparable imaging and had a PiB PET SUVr greater than 1.5. MAIN OUTCOMES AND MEASURES Rate of change of cortical volume on volumetric magnetic resonance images and rate of change of glucose metabolism on FDG PET scan results. RESULTS There were 25 CN participants with both high PiB retention and low hippocampal volume or FDG hypometabolism at baseline (preclinical AD stages 2 + 3). On follow-up scans, the preclinical AD stage 2 + 3 participants had greater loss of medial temporal lobe volume and greater glucose hypometabolism in the medial temporal lobe compared with the other CN groups. The changes were similar to those in the cognitively impaired participants. Extratemporal regions did not show similar changes. CONCLUSIONS AND RELEVANCE Higher rates of medial temporal neurodegeneration occur in CN individuals who, on their initial scans, had abnormal levels of both β-amyloid and brain injury biomarkers. Although preclinical AD is currently only a research topic, the description of its brain structural changes will be critical for trials designed to prevent or forestall dementia due to AD.
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Affiliation(s)
- David S Knopman
- Mayo Clinic Alzheimer's Disease Research Center, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
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50
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Cerebral amyloid PET imaging in Alzheimer's disease. Acta Neuropathol 2013; 126:643-57. [PMID: 24100688 DOI: 10.1007/s00401-013-1185-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 09/24/2013] [Accepted: 09/25/2013] [Indexed: 12/14/2022]
Abstract
The devastating effects of the still incurable Alzheimer's disease (AD) project an ever increasing shadow of burden on the health care system and society in general. In this ominous context, amyloid (Aβ) imaging is considered by many of utmost importance for progress towards earlier AD diagnosis and for potential development of effective therapeutic interventions. Amyloid imaging positron emission tomography procedures offer the opportunity for accurate mapping and quantification of amyloid-Aβ neuroaggregate deposition in the living brain of AD patients. This review analyzes the perceived value of current Aβ imaging probes and their clinical utilization and, based on amyloid imaging results, offers a hypothesis on the effects of amyloid deposition on the biology of AD and its progression. It also analyzes lingering questions permeating the field of amyloid imaging on the apparent contradictions between imaging results and known neuropathology brain regional deposition of Aβ aggregates. As a result, the review also discusses literature evidence as to whether brain Aβ deposition is truly visualized and measured with these amyloid imaging agents, which would have significant implications in the understanding of the biological AD cascade and in the monitoring of therapeutic interventions with these surrogate Aβ markers.
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