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Russo ML, Ayala G, Neal D, Rogalsky AE, Ahmad S, Musial TF, Pearlman M, Bean LA, Farooqi AK, Ahmed A, Castaneda A, Patel A, Parduhn Z, Haddad LG, Gabriel A, Disterhoft JF, Nicholson DA. Alzheimer's-linked axonal changes accompany elevated antidromic action potential failure rate in aged mice. Brain Res 2024; 1841:149083. [PMID: 38866308 DOI: 10.1016/j.brainres.2024.149083] [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: 12/28/2023] [Revised: 04/22/2024] [Accepted: 06/09/2024] [Indexed: 06/14/2024]
Abstract
Alzheimer's disease (AD) affects both grey and white matter (WM), but considerably more is known about the former. Interestingly, WM disruption has been consistently observed and thoroughly described using imaging modalities, particularly MRI which has shown WM functional disconnections between the hippocampus and other brain regions during AD pathogenesis when early neurodegeneration and synapse loss are also evident. Nonetheless, high-resolution structural and functional analyses of WM during AD pathogenesis remain scarce. Given the importance of the myelinated axons in the WM for conveying information across brain regions, such studies will provide valuable information on the cellular drivers and consequences of WM disruption that contribute to the characteristic cognitive decline of AD. Here, we employed a multi-scale approach to investigate hippocampal WM disruption during AD pathogenesis and determine whether hippocampal WM changes accompany the well-documented grey matter losses. Our data indicate that ultrastructural myelin disruption is elevated in the alveus in human AD cases and increases with age in 5xFAD mice. Unreliable action potential propagation and changes to sodium channel expression at the node of Ranvier co-emerged with this deterioration. These findings provide important insight to the neurobiological substrates and functional consequences of decreased WM integrity and are consistent with the notion that hippocampal disconnection contributes to cognitive changes in AD.
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Affiliation(s)
- Matthew L Russo
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
| | - Gelique Ayala
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Demetria Neal
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Annalise E Rogalsky
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Suzan Ahmad
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Timothy F Musial
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Morgan Pearlman
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Linda A Bean
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Anise K Farooqi
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Aysha Ahmed
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Adrian Castaneda
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Aneri Patel
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Zachary Parduhn
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Loreece G Haddad
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - Ashley Gabriel
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
| | - John F Disterhoft
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Daniel A Nicholson
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA
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Pappas C, Bauer CE, Zachariou V, Maillard P, Caprihan A, Shao X, Wang DJ, Gold BT. MRI free water mediates the association between water exchange rate across the blood brain barrier and executive function among older adults. IMAGING NEUROSCIENCE (CAMBRIDGE, MASS.) 2024; 2:1-15. [PMID: 38947942 PMCID: PMC11211995 DOI: 10.1162/imag_a_00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/27/2024] [Accepted: 05/03/2024] [Indexed: 07/02/2024]
Abstract
Vascular risk factors contribute to cognitive aging, with one such risk factor being dysfunction of the blood brain barrier (BBB). Studies using non-invasive magnetic resonance imaging (MRI) techniques, such as diffusion prepared arterial spin labeling (DP-ASL), can estimate BBB function by measuring water exchange rate (kw). DP-ASL kw has been associated with cognition, but the directionality and strength of the relationship is still under investigation. An additional variable that measures water in extracellular space and impacts cognition, MRI free water (FW), may help explain prior findings. A total of 94 older adults without dementia (Mean age = 74.17 years, 59.6% female) underwent MRI (DP-ASL, diffusion weighted imaging (DWI)) and cognitive assessment. Mean kw was computed across the whole brain (WB), and mean white matter FW was computed across all white matter. The relationship between kw and three cognitive domains (executive function, processing speed, memory) was tested using multiple linear regression. FW was tested as a mediator of the kw-cognitive relationship using the PROCESS macro. A positive association was found between WB kw and executive function [F(4,85) = 7.81, p < .001, R2= 0.269; β = .245, p = .014]. Further, this effect was qualified by subsequent results showing that FW was a mediator of the WB kw-executive function relationship (indirect effect results: standardized effect = .060, bootstrap confidence interval = .0006 to .1411). Results suggest that lower water exchange rate (kw) may contribute to greater total white matter (WM) FW which, in turn, may disrupt executive function. Taken together, proper fluid clearance at the BBB contributes to higher-order cognitive abilities.
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Affiliation(s)
- Colleen Pappas
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Christopher E. Bauer
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Valentinos Zachariou
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
- Department of Behavioral Science, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Pauline Maillard
- Department of Neurology, University of California at Davis, Davis, CA, United States
- Center for Neurosciences, University of California at Davis, Davis, CA, United States
| | | | - Xingfeng Shao
- Laboratory of FMRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Danny J.J. Wang
- Laboratory of FMRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Brian T. Gold
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, United States
- Department of Radiology, College of Medicine, University of Kentucky, Lexington, KY, United States
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, United States
- Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, United States
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3
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Huang Z, Jordan JD, Zhang Q. Myelin Pathology in Alzheimer's Disease: Potential Therapeutic Opportunities. Aging Dis 2024; 15:698-713. [PMID: 37548935 PMCID: PMC10917545 DOI: 10.14336/ad.2023.0628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/28/2023] [Indexed: 08/08/2023] Open
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by memory loss and cognitive decline. Despite significant efforts over several decades, our understanding of the pathophysiology of this disease is still incomplete. Myelin is a multi-layered membrane structure ensheathing neuronal axons, which is essential for the fast and effective propagation of action potentials along the axons. Recent studies highlight the critical involvement of myelin in memory consolidation and reveal its vulnerability in various pathological conditions. Notably, apart from the classic amyloid hypothesis, myelin degeneration has been proposed as another critical pathophysiological feature of AD, which could occur prior to the development of amyloid pathology. Here, we review recent works supporting the critical role of myelin in cognition and myelin pathology during AD progression, with a focus on the mechanisms underlying myelin degeneration in AD. We also discuss the complex intersections between myelin pathology and typical AD pathophysiology, as well as the therapeutic potential of pro-myelinating approaches for this disease. Overall, these findings implicate myelin degeneration as a critical contributor to AD-related cognitive deficits and support targeting myelin repair as a promising therapeutic strategy for AD.
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Affiliation(s)
- Zhihai Huang
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, LA 71103 USA
| | - J. Dedrick Jordan
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, LA 71103 USA
| | - Quanguang Zhang
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, LA 71103 USA
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4
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Zota I, Chanoumidou K, Charalampopoulos I, Gravanis A. Dynamics of myelin deficits in the 5xFAD mouse model for Alzheimer's disease and the protective role of BDNF. Glia 2024; 72:809-827. [PMID: 38205694 DOI: 10.1002/glia.24505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 12/08/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024]
Abstract
Recent findings highlight myelin breakdown as a decisive early event in Alzheimer's Disease (AD) acting as aggravating factor of its progression. However, it is still unclear whether myelin loss is attributed to increased oligodendrocyte vulnerability, reduced repairing capacity or toxic stimuli. In the present study, we sought to clarify the starting point of myelin disruption accompanied with Oligodendrocyte Progenitor Cell (OPC) elimination in the brain of the 5xFAD mouse model of AD at 6 months of age in Dentate Gyrus of the hippocampus in relation to neurotrophin system. Prominent inflammation presence was detected since the age of 6 months playing a key role in myelin disturbance and AD progression. Expression analysis of neurotrophin receptors in OPCs was performed to identify new targets that could increase myelination in health and disease. OPCs in both control and 5xFAD mice express TrkB, TrkC and p75 receptors but not TrkA. Brain-derived neurotrophic factor (BDNF) that binds to TrkB receptor is well-known about its pro-myelination effect, promoting oligodendrocytes proliferation and differentiation, so we focused our investigation on its effects in OPCs under neurodegenerative conditions. Our in vitro results showed that BDNF rescues OPCs from death and promotes their proliferation and differentiation in presence of the toxic Amyloid-β 1-42. Collectively, our results indicate that BDNF possess an additional neuroprotective role through its actions on oligodendrocytic component and its use could be proposed as a drug-based myelin-enhancing strategy, complementary to amyloid and tau centered therapies in AD.
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Affiliation(s)
- Ioanna Zota
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas (IMBB-FORTH), Heraklion, Crete, Greece
| | - Konstantina Chanoumidou
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas (IMBB-FORTH), Heraklion, Crete, Greece
| | - Ioannis Charalampopoulos
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas (IMBB-FORTH), Heraklion, Crete, Greece
| | - Achille Gravanis
- Department of Pharmacology, Medical School, University of Crete, Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas (IMBB-FORTH), Heraklion, Crete, Greece
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Cheng GWY, Ma IWT, Huang J, Yeung SHS, Ho P, Chen Z, Mak HKF, Herrup K, Chan KWY, Tse KH. Cuprizone drives divergent neuropathological changes in different mouse models of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.24.547147. [PMID: 37546935 PMCID: PMC10402084 DOI: 10.1101/2023.07.24.547147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Myelin degradation is a normal feature of brain aging that accelerates in Alzheimer's disease (AD). To date, however, the underlying biological basis of this correlation remains elusive. The amyloid cascade hypothesis predicts that demyelination is caused by increased levels of the β-amyloid (Aβ) peptide. Here we report on work supporting the alternative hypothesis that early demyelination is upstream of amyloid. We challenged two different mouse models of AD (R1.40 and APP/PS1) using cuprizone-induced demyelination and tracked the responses with both neuroimaging and neuropathology. In oppose to amyloid cascade hypothesis, R1.40 mice, carrying only a single human mutant APP (Swedish; APP SWE ) transgene, showed a more abnormal changes of magnetization transfer ratio and diffusivity than in APP/PS1 mice, which carry both APP SWE and a second PSEN1 transgene (delta exon 9; PSEN1 dE9 ). Although cuprizone targets oligodendrocytes (OL), magnetic resonance spectroscopy and targeted RNA-seq data in R1.40 mice suggested a possible metabolic alternation in axons. In support of alternative hypotheses, cuprizone induced significant intraneuronal amyloid deposition in young APP/PS1, but not in R1.40 mice, and it suggested the presence of PSEN deficiencies, may accelerate Aβ deposition upon demyelination. In APP/PS1, mature OL is highly vulnerable to cuprizone with significant DNA double strand breaks (53BP1 + ) formation. Despite these major changes in myelin, OLs, and Aβ immunoreactivity, no cognitive impairment or hippocampal pathology was detected in APP/PS1 mice after cuprizone treatment. Together, our data supports the hypothesis that myelin loss can be the cause, but not the consequence, of AD pathology. SIGNIFICANCE STATEMENT The causal relationship between early myelin loss and the progression of Alzheimer's disease remains unclear. Using two different AD mouse models, R1.40 and APP/PS1, our study supports the hypothesis that myelin abnormalities are upstream of amyloid production and deposition. We find that acute demyelination initiates intraneuronal amyloid deposition in the frontal cortex. Further, the loss of oligodendrocytes, coupled with the accelerated intraneuronal amyloid deposition, interferes with myelin tract diffusivity at a stage before any hippocampus pathology or cognitive impairments occur. We propose that myelin loss could be the cause, not the consequence, of amyloid pathology during the early stages of Alzheimer's disease.
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Lindsay SL, McCanney GA, Zhan J, Scheld M, Smith RS, Goodyear CS, Yates EA, Kipp M, Turnbull JE, Barnett SC. Low sulfated heparan sulfate mimetic differentially affects repair in immune-mediated and toxin-induced experimental models of demyelination. Glia 2023; 71:1683-1698. [PMID: 36945189 PMCID: PMC10952530 DOI: 10.1002/glia.24363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 03/07/2023] [Accepted: 03/10/2023] [Indexed: 03/23/2023]
Abstract
There is an urgent need for therapies that target the multicellular pathology of central nervous system (CNS) disease. Modified, nonanticoagulant heparins mimic the heparan sulfate glycan family and are known regulators of multiple cellular processes. In vitro studies have demonstrated that low sulfated modified heparin mimetics (LS-mHeps) drive repair after CNS demyelination. Herein, we test LS-mHep7 (an in vitro lead compound) in experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced demyelination. In EAE, LS-mHep7 treatment resulted in faster recovery and rapidly reduced inflammation which was accompanied by restoration of animal weight. LS-mHep7 treatment had no effect on remyelination or on OLIG2 positive oligodendrocyte numbers within the corpus callosum in the cuprizone model. Further in vitro investigation confirmed that LS-mHep7 likely mediates its pro-repair effect in the EAE model by sequestering inflammatory cytokines, such as CCL5 which are upregulated during immune-mediated inflammatory attacks. These data support the future clinical translation of this next generation modified heparin as a treatment for CNS diseases with active immune system involvement.
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Affiliation(s)
- Susan L. Lindsay
- School of Infection and ImmunityUniversity of Glasgow120 University PlaceGlasgowG12 8TAUK
| | - George A. McCanney
- School of Infection and ImmunityUniversity of Glasgow120 University PlaceGlasgowG12 8TAUK
| | - Jiangshan Zhan
- Institute of AnatomyUniversity of RostockGertrudenstrasse 918057RostockGermany
| | - Miriam Scheld
- Institute of Neuroanatomy, Faculty of MedicineRWTH Aachen University52074AachenGermany
| | - Rebecca Sherrard Smith
- School of Infection and ImmunityUniversity of Glasgow120 University PlaceGlasgowG12 8TAUK
| | - Carl S. Goodyear
- School of Infection and ImmunityUniversity of Glasgow120 University PlaceGlasgowG12 8TAUK
| | - Edwin A. Yates
- Institute of Systems, Molecules and Integrative BiologyUniversity of LiverpoolLiverpoolL69 7ZBUK
| | - Markus Kipp
- Institute of AnatomyUniversity of RostockGertrudenstrasse 918057RostockGermany
| | - Jeremy E. Turnbull
- Institute of Systems, Molecules and Integrative BiologyUniversity of LiverpoolLiverpoolL69 7ZBUK
- Centre for GlycosciencesKeele UniversityKeeleST5 5BGUK
| | - Susan C. Barnett
- School of Infection and ImmunityUniversity of Glasgow120 University PlaceGlasgowG12 8TAUK
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7
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Fernandez-Alvarez M, Atienza M, Cantero JL. Cortical amyloid-beta burden is associated with changes in intracortical myelin in cognitively normal older adults. Transl Psychiatry 2023; 13:115. [PMID: 37024484 PMCID: PMC10079650 DOI: 10.1038/s41398-023-02420-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/08/2023] Open
Abstract
Amyloid-beta (Aβ) aggregates and myelin breakdown are among the earliest detrimental effects of Alzheimer's disease (AD), likely inducing abnormal patterns of neuronal communication within cortical networks. However, human in vivo evidence linking Aβ burden, intracortical myelin, and cortical synchronization is lacking in cognitively normal older individuals. Here, we addressed this question combining 18F-Florbetaben-PET imaging, cortical T1-weigthed/T2-weighted (T1w/T2w) ratio maps, and resting-state functional connectivity (rs-FC) in cognitively unimpaired older adults. Results showed that global Aβ burden was both positively and negatively associated with the T1w/T2w ratio in different cortical territories. Affected cortical regions were further associated with abnormal patterns of rs-FC and with subclinical cognitive deficits. Finally, causal mediation analysis revealed that the negative impact of T1w/T2w ratio in left posterior cingulate cortex on processing speed was driven by Aβ burden. Collectively, these findings provide novel insights into the relationship between initial Aβ plaques and intracortical myelin before the onset of cognitive decline, which may contribute to monitor the efficacy of novel disease-modifying strategies in normal elderly individuals at risk for cognitive impairment.
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Affiliation(s)
- Marina Fernandez-Alvarez
- Laboratory of Functional Neuroscience, Pablo de Olavide University, Seville, Spain
- CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
| | - Mercedes Atienza
- Laboratory of Functional Neuroscience, Pablo de Olavide University, Seville, Spain
- CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, Madrid, Spain
| | - Jose L Cantero
- Laboratory of Functional Neuroscience, Pablo de Olavide University, Seville, Spain.
- CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, Madrid, Spain.
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Brain region-specific myelinogenesis is not directly linked to amyloid-β in APP/PS1 transgenic mice. Exp Neurol 2023; 362:114344. [PMID: 36736651 DOI: 10.1016/j.expneurol.2023.114344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Alzheimer's disease (AD) is characterized by aggregating amyloid beta-protein (Aβ). Recent evidence has shown that insufficient myelinogenesis contributes to AD-related functional deficits. However, it remains unclear whether Aβ, in either plaque or soluble form, could alter myelinogenesis in AD brains. By cell-lineage tracing and labeling, we found both myelinogenesis and Aβ deposits displayed a region-specific pattern in the 13-month-old APP/PS1 transgenic mouse brains. Aβ plaques cause focal demyelination, but only about 15% Aβ plaques are closely associated with newly formed myelin in the APP/PS1 brains. Further, the Aβ plaque total area and the amount of new myelin are not linearly correlated across different cortical regions, suggesting that Aβ plaques induce demyelination but may not exclusively trigger remyelination. To understand the role of soluble Aβ in regulating myelinogenesis, we chose to observe the visual system, wherein soluble Aβ is detectable but without the presence of Aβ plaques in the APP/PS1 retina, optic nerve, and optic tract. Interestingly, newly-formed myelin density was not significantly altered in the APP/PS1 optic nerves and optic tracts as compared to the wildtype controls, suggesting soluble Aβ probably does not change myelinogenesis. Further, treatment of purified oligodendrocyte precursor cells (OPCs) with soluble Aβ (oligomers) for 48 h did not change the cell densities of MBP positive cells and PDGFRα positive OPCs in vitro. Consistently, injection of soluble Aβ into the lateral ventricles did not alter myelinogenesis in the corpus callosum of NG2-CreErt; Tau-mGFP mice significantly. Together, these findings indicate that the region-dependent myelinogenesis in AD brains is not directly linked to Aβ, but rather probably a synergic result in adapting to AD pathology.
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Maitre M, Jeltsch-David H, Okechukwu NG, Klein C, Patte-Mensah C, Mensah-Nyagan AG. Myelin in Alzheimer's disease: culprit or bystander? Acta Neuropathol Commun 2023; 11:56. [PMID: 37004127 PMCID: PMC10067200 DOI: 10.1186/s40478-023-01554-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder with neuronal and synaptic losses due to the accumulation of toxic amyloid β (Αβ) peptide oligomers, plaques, and tangles containing tau (tubulin-associated unit) protein. While familial AD is caused by specific mutations, the sporadic disease is more common and appears to result from a complex chronic brain neuroinflammation with mitochondriopathies, inducing free radicals' accumulation. In aged brain, mutations in DNA and several unfolded proteins participate in a chronic amyloidosis response with a toxic effect on myelin sheath and axons, leading to cognitive deficits and dementia. Αβ peptides are the most frequent form of toxic amyloid oligomers. Accumulations of misfolded proteins during several years alters different metabolic mechanisms, induce chronic inflammatory and immune responses with toxic consequences on neuronal cells. Myelin composition and architecture may appear to be an early target for the toxic activity of Aβ peptides and others hydrophobic misfolded proteins. In this work, we describe the possible role of early myelin alterations in the genesis of neuronal alterations and the onset of symptomatology. We propose that some pathophysiological and clinical forms of the disease may arise from structural and metabolic disorders in the processes of myelination/demyelination of brain regions where the accumulation of non-functional toxic proteins is important. In these forms, the primacy of the deleterious role of amyloid peptides would be a matter of questioning and the initiating role of neuropathology would be primarily the fact of dysmyelination.
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Affiliation(s)
- Michel Maitre
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France.
| | - Hélène Jeltsch-David
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France
- Biotechnologie et signalisation cellulaire, UMR 7242 CNRS, Université de Strasbourg, 300 Boulevard Sébastien Brant CS 10413, Illkirch cedex, 67412, France
| | - Nwife Getrude Okechukwu
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France
| | - Christine Patte-Mensah
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France
| | - Ayikoe-Guy Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, Fédération de Médecine Translationnelle de Strasbourg (FMTS), INSERM U1119, Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, Strasbourg, 67000, France
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10
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Sharp FR, DeCarli CS, Jin LW, Zhan X. White matter injury, cholesterol dysmetabolism, and APP/Abeta dysmetabolism interact to produce Alzheimer's disease (AD) neuropathology: A hypothesis and review. Front Aging Neurosci 2023; 15:1096206. [PMID: 36845656 PMCID: PMC9950279 DOI: 10.3389/fnagi.2023.1096206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
We postulate that myelin injury contributes to cholesterol release from myelin and cholesterol dysmetabolism which contributes to Abeta dysmetabolism, and combined with genetic and AD risk factors, leads to increased Abeta and amyloid plaques. Increased Abeta damages myelin to form a vicious injury cycle. Thus, white matter injury, cholesterol dysmetabolism and Abeta dysmetabolism interact to produce or worsen AD neuropathology. The amyloid cascade is the leading hypothesis for the cause of Alzheimer's disease (AD). The failure of clinical trials based on this hypothesis has raised other possibilities. Even with a possible new success (Lecanemab), it is not clear whether this is a cause or a result of the disease. With the discovery in 1993 that the apolipoprotein E type 4 allele (APOE4) was the major risk factor for sporadic, late-onset AD (LOAD), there has been increasing interest in cholesterol in AD since APOE is a major cholesterol transporter. Recent studies show that cholesterol metabolism is intricately involved with Abeta (Aβ)/amyloid transport and metabolism, with cholesterol down-regulating the Aβ LRP1 transporter and upregulating the Aβ RAGE receptor, both of which would increase brain Aβ. Moreover, manipulating cholesterol transport and metabolism in rodent AD models can ameliorate pathology and cognitive deficits, or worsen them depending upon the manipulation. Though white matter (WM) injury has been noted in AD brain since Alzheimer's initial observations, recent studies have shown abnormal white matter in every AD brain. Moreover, there is age-related WM injury in normal individuals that occurs earlier and is worse with the APOE4 genotype. Moreover, WM injury precedes formation of plaques and tangles in human Familial Alzheimer's disease (FAD) and precedes plaque formation in rodent AD models. Restoring WM in rodent AD models improves cognition without affecting AD pathology. Thus, we postulate that the amyloid cascade, cholesterol dysmetabolism and white matter injury interact to produce and/or worsen AD pathology. We further postulate that the primary initiating event could be related to any of the three, with age a major factor for WM injury, diet and APOE4 and other genes a factor for cholesterol dysmetabolism, and FAD and other genes for Abeta dysmetabolism.
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Affiliation(s)
| | - Charles S. DeCarli
- Department of Neurology, The MIND Institute, University of California at Davis Medical Center, Sacramento, CA, United States
| | - Lee-Way Jin
- Department of Neurology, The MIND Institute, University of California at Davis Medical Center, Sacramento, CA, United States
| | - Xinhua Zhan
- Department of Neurology, The MIND Institute, University of California at Davis Medical Center, Sacramento, CA, United States
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Hirschfeld LR, Risacher SL, Nho K, Saykin AJ. Myelin repair in Alzheimer's disease: a review of biological pathways and potential therapeutics. Transl Neurodegener 2022; 11:47. [PMID: 36284351 PMCID: PMC9598036 DOI: 10.1186/s40035-022-00321-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/15/2022] [Indexed: 11/29/2022] Open
Abstract
This literature review investigates the significant overlap between myelin-repair signaling pathways and pathways known to contribute to hallmark pathologies of Alzheimer's disease (AD). We discuss previously investigated therapeutic targets of amyloid, tau, and ApoE, as well as other potential therapeutic targets that have been empirically shown to contribute to both remyelination and progression of AD. Current evidence shows that there are multiple AD-relevant pathways which overlap significantly with remyelination and myelin repair through the encouragement of oligodendrocyte proliferation, maturation, and myelin production. There is a present need for a single, cohesive model of myelin homeostasis in AD. While determining a causative pathway is beyond the scope of this review, it may be possible to investigate the pathological overlap of myelin repair and AD through therapeutic approaches.
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Affiliation(s)
- Lauren Rose Hirschfeld
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Shannon L Risacher
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kwangsik Nho
- Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
- School of Informatics and Computing, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Andrew J Saykin
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Indiana Alzheimer's Disease Research Center, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
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12
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Aires V, Ziegler-Waldkirch S, Friesen M, Reichardt W, Erny D, Loreth D, Harborne A, Kretz O, von Elverfeldt D, Meyer-Luehmann M. Seed-induced Aβ deposits in the corpus callosum disrupt white matter integrity in a mouse model of Alzheimer’s disease. Front Cell Neurosci 2022; 16:862918. [PMID: 36003141 PMCID: PMC9393256 DOI: 10.3389/fncel.2022.862918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Neuropathologically, Alzheimer’s disease (AD) is characterized by the accumulation of amyloid-beta peptide (Aβ) and subsequent formation of the so-called Aβ plaques. Along with neuronal loss, previous studies report white matter anomalies and corpus callosum (CC) atrophy in AD patients. Notably, perturbations in the white matter can be observed years before expected disease onset, suggesting that early stages of disease progression play a role in AD-associated loss of myelin integrity. Through seed-induced deposition of Aβ, we are able to examine alterations of central nervous system (CNS) integrity during the initial stages of plaque formation. In this study, we investigate the impact of Aβ seeding in the CC utilizing various imaging techniques as well as quantitative gene expression analysis and demonstrate that Aβ deposits result in an imbalance of glial cells in the CC. We found increased amounts of phagocytic microglia and reactive astrocytes, while oligodendrocyte progenitor cell (OPC) numbers were reduced. Moreover, white matter aberrations adjacent to the Aβ seeding were observed together with an overall decline in callosal myelination. This data indicate that the initial stages of plaque formation induce oligodendrocyte dysfunction, which might ultimately lead to myelin loss.
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Affiliation(s)
- Vanessa Aires
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Stephanie Ziegler-Waldkirch
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marina Friesen
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wilfried Reichardt
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, Medical Center – University of Freiburg, Freiburg, Germany
- German Consortium for Translational Cancer Research (DKTK), Heidelberg, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Daniel Erny
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Neuropathology, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Desiree Loreth
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andrew Harborne
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Oliver Kretz
- Department of Internal Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dominik von Elverfeldt
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, Medical Center – University of Freiburg, Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center – University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- *Correspondence: Melanie Meyer-Luehmann,
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13
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Co-Ultramicronized Palmitoylethanolamide/Luteolin Restores Oligodendrocyte Homeostasis via Peroxisome Proliferator-Activated Receptor-α in an In Vitro Model of Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10061236. [PMID: 35740258 PMCID: PMC9219769 DOI: 10.3390/biomedicines10061236] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 12/22/2022] Open
Abstract
Oligodendrocytes are cells fundamental for brain functions as they form the myelin sheath and feed axons. They perform these critical functions thanks to the cooperation with other glial cells, mainly astrocytes. The astrocyte/oligodendrocyte crosstalk needs numerous mediators and receptors, such as peroxisome proliferator-activated receptors (PPARs). PPAR agonists promote oligodendrocyte precursor cells (OPCs) maturation in myelinating oligodendrocytes. In the Alzheimer’s disease brain, deposition of beta-amyloid (Aβ) has been linked to several alterations, including astrogliosis and changes in OPCs maturation. However, very little is known about the molecular mechanisms. Here, we investigated for the first time the maturation of OPCs co-cultured with astrocytes in an in vitro model of Aβ1–42 toxicity. We also tested the potential beneficial effect of the anti-inflammatory and neuroprotective composite palmitoylethanolamide and luteolin (co-ultra PEALut), which is known to engage the isoform alfa of the PPARs. Our results show that Aβ1–42 triggers astrocyte reactivity and inflammation and reduces the levels of growth factors important for OPCs maturation. Oligodendrocytes indeed show low cell surface area and few arborizations. Co-ultra PEALut counteracts the Aβ1–42-induced inflammation and astrocyte reactivity preserving the morphology of co-cultured oligodendrocytes through a mechanism that in some cases involves PPAR-α. This is the first evidence of the negative effects exerted by Aβ1–42 on astrocyte/oligodendrocyte crosstalk and discloses a never-explored co-ultra PEALut ability in restoring oligodendrocyte homeostasis.
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Ilina A, Khavinson V, Linkova N, Petukhov M. Neuroepigenetic Mechanisms of Action of Ultrashort Peptides in Alzheimer's Disease. Int J Mol Sci 2022; 23:ijms23084259. [PMID: 35457077 PMCID: PMC9032300 DOI: 10.3390/ijms23084259] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 12/23/2022] Open
Abstract
Epigenetic regulation of gene expression is necessary for maintaining higher-order cognitive functions (learning and memory). The current understanding of the role of epigenetics in the mechanism of Alzheimer’s disease (AD) is focused on DNA methylation, chromatin remodeling, histone modifications, and regulation of non-coding RNAs. The pathogenetic links of this disease are the misfolding and aggregation of tau protein and amyloid peptides, mitochondrial dysfunction, oxidative stress, impaired energy metabolism, destruction of the blood–brain barrier, and neuroinflammation, all of which lead to impaired synaptic plasticity and memory loss. Ultrashort peptides are promising neuroprotective compounds with a broad spectrum of activity and without reported side effects. The main aim of this review is to analyze the possible epigenetic mechanisms of the neuroprotective action of ultrashort peptides in AD. The review highlights the role of short peptides in the AD pathophysiology. We formulate the hypothesis that peptide regulation of gene expression can be mediated by the interaction of short peptides with histone proteins, cis- and transregulatory DNA elements and effector molecules (DNA/RNA-binding proteins and non-coding RNA). The development of therapeutic agents based on ultrashort peptides may offer a promising addition to the multifunctional treatment of AD.
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Affiliation(s)
- Anastasiia Ilina
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 19711 Saint Petersburg, Russia; (V.K.); (N.L.)
- Department of General Pathology and Pathological Physiology, Institute of Experimental Medicine, 197376 Saint Petersburg, Russia
- Correspondence: ; Tel.: +7-(953)145-89-58
| | - Vladimir Khavinson
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 19711 Saint Petersburg, Russia; (V.K.); (N.L.)
- Group of Peptide Regulation of Aging, Pavlov Institute of Physiology, Russian Academy of Sciences, 199034 Saint Petersburg, Russia
| | - Natalia Linkova
- Department of Biogerontology, Saint Petersburg Institute of Bioregulation and Gerontology, 19711 Saint Petersburg, Russia; (V.K.); (N.L.)
| | - Mikhael Petukhov
- Department of Molecular Radiation Biophysics, Petersburg Nuclear Physics Institute Named after B.P. Konstantinov, NRC “Kurchatov Institute”, 188300 Gatchina, Russia;
- Group of Biophysics, Higher Engineering and Technical School, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
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15
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Zheng M, Liu Z, Mana L, Qin G, Huang S, Gong Z, Tian M, He Y, Wang P. Shenzhiling oral liquid protects the myelin sheath against Alzheimer's disease through the PI3K/Akt-mTOR pathway. JOURNAL OF ETHNOPHARMACOLOGY 2021; 278:114264. [PMID: 34082015 DOI: 10.1016/j.jep.2021.114264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 05/22/2021] [Accepted: 05/27/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Shenzhiling oral liquid (SZL), a traditional Chinese medicine (TCM) compound, is firstly approved by the Chinese Food and Drug Administration (CFDA) for the treatment of mild to moderate Alzheimer's disease (AD). SZL is composed of ten Chinese herbs, and the precise therapy mechanism of its action to AD is far from fully understood. AIM OF THE STUDY The purpose of this study was to observe whether SZL is an effective therapy for amyloid-beta (Aβ)-induced myelin sheath and oligodendrocytes impairments. Notably, the primary aim was to elucidate whether and through what underlying mechanism SZL protects the myelin sheath through the PI3K/Akt-mTOR signaling pathway in Aβ42-induced OLN-93 oligodendrocytes in vitro. MATERIALS AND METHODS APP/PS1 mice were treated with SZL or donepezil continuously for three months, and Aβ42-induced oligodendrocyte OLN-93 cells mimicking AD pathogenesis of myelin sheath impairments were incubated with SZL-containing serum or with donepezil. LC-MS/MS was used to analysis the active components of SZL and SZL-containing serum. The Y maze test was administered after 3 months of treatment, and the hippocampal tissues of the APP/PS1 mice were then harvested for observation of myelin sheath and oligodendrocyte morphology. Cell viability and toxicity were assessed using CCK-8 and lactate dehydrogenase (LDH) release assays, and flow cytometry was used to measure cell apoptosis. The expression of the myelin proteins MBP, PLP, and MAG and that of Aβ42 and Aβ40 in the hippocampi of APP/PS1 mice were examined after SZL treatment. Simultaneously, the expression of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR were also examined. The expression of proteins, including CNPase, Olig2, NKX2.2, MBP, PLP, MAG, MOG, p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR, was determined by immunofluorescence and Western blot, and the corresponding gene expression was evaluated by qPCR in Aβ42-induced OLN-93 oligodendrocytes. RESULTS LC-MS/MS detected a total of 126 active compounds in SZL-containing serum, including terpenoids, flavones, phenols, phenylpropanoids and phenolic acids. SZL treatment significantly improved memory and cognition in APP/PS1 mice and decreased the G-ratio of myelin sheath, alleviated myelin sheath and oligodendrocyte impairments by decreasing Aβ42 and Aβ40 accumulation and increasing the expression of myelin proteins MBP, PLP, MAG, and PI3K/Akt-mTOR signaling pathway associated protein in the hippocampi of APP/PS1 mice. SZL-containing serum also significantly reversed the OLN-93 cell injury induced by Aβ42 by increasing cell viability and enhanced the expression of MBP, PLP, MAG, and MOG. Meanwhile, SZL-containing serum facilitated the maturation and differentiation of oligodendrocytes in Aβ42-induced OLN-93 cells by heightening the expression of CNPase, Olig2 and NKX2.2. SZL-containing serum treatment also fostered the expression of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, and mTOR, indicating an activating PI3K/Akt-mTOR signaling pathway in OLN-93 cells. Furthermore, the effects of SZL on myelin proteins, p-Akt, and p-mTOR were clearly inhibited by LY294002 and/or rapamycin, antagonists of PI3K and m-TOR, respectively. CONCLUSIONS Our findings indicate that SZL exhibits a neuroprotective effect on the myelin sheath by promoting the expression of myelin proteins during AD, and its mechanism of action is closely related to the activation of the PI3K/Akt-mTOR signaling pathway.
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Affiliation(s)
- Mingcui Zheng
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Zhenhong Liu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China; Institute for Brain Disorders, Beijing University of Chinese Medicine (BUCM), Beijing, 100029, China.
| | - Lulu Mana
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China; Xinjiang Medical University, Urumqi, 830011, China.
| | - Gaofeng Qin
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Shuaiyang Huang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Zhuoyan Gong
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Meijing Tian
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Yannan He
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
| | - Pengwen Wang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine (BUCM), Beijing, 100700, China; Key Laboratory of Pharmacology Dongzhimen Hospital (BUCM), State Administration of Traditional Chinese Medicine, Beijing, 100700, China.
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Lloret A, Esteve D, Lloret MA, Monllor P, López B, León JL, Cervera-Ferri A. Is Oxidative Stress the Link Between Cerebral Small Vessel Disease, Sleep Disruption, and Oligodendrocyte Dysfunction in the Onset of Alzheimer's Disease? Front Physiol 2021; 12:708061. [PMID: 34512381 PMCID: PMC8424010 DOI: 10.3389/fphys.2021.708061] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/28/2021] [Indexed: 01/07/2023] Open
Abstract
Oxidative stress is an early occurrence in the development of Alzheimer’s disease (AD) and one of its proposed etiologic hypotheses. There is sufficient experimental evidence supporting the theory that impaired antioxidant enzymatic activity and increased formation of reactive oxygen species (ROS) take place in this disease. However, the antioxidant treatments fail to stop its advancement. Its multifactorial condition and the diverse toxicological cascades that can be initiated by ROS could possibly explain this failure. Recently, it has been suggested that cerebral small vessel disease (CSVD) contributes to the onset of AD. Oxidative stress is a central hallmark of CSVD and is depicted as an early causative factor. Moreover, data from various epidemiological and clinicopathological studies have indicated a relationship between CSVD and AD where endothelial cells are a source of oxidative stress. These cells are also closely related to oligodendrocytes, which are, in particular, sensitive to oxidation and lead to myelination being compromised. The sleep/wake cycle is another important control in the proliferation, migration, and differentiation of oligodendrocytes, and sleep loss reduces myelin thickness. Moreover, sleep plays a crucial role in resistance against CSVD, and poor sleep quality increases the silent markers of this vascular disease. Sleep disruption is another early occurrence in AD and is related to an increase in oxidative stress. In this study, the relationship between CSVD, oligodendrocyte dysfunction, and sleep disorders is discussed while focusing on oxidative stress as a common occurrence and its possible role in the onset of AD.
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Affiliation(s)
- Ana Lloret
- INCLIVA, CIBERFES, Department of Physiology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Daniel Esteve
- INCLIVA, CIBERFES, Department of Physiology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Maria Angeles Lloret
- Department of Clinical Neurophysiology, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Paloma Monllor
- INCLIVA, CIBERFES, Department of Physiology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Begoña López
- Department of Neurology, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - José Luis León
- Departament of Neuroradiology, Ascires Biomedical Group, Hospital Clinico Universitario, Valencia, Spain
| | - Ana Cervera-Ferri
- Department of Anatomy and Human Embryology, University of Valencia, Valencia, Spain
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Vignon A, Salvador-Prince L, Lehmann S, Perrier V, Torrent J. Deconstructing Alzheimer's Disease: How to Bridge the Gap between Experimental Models and the Human Pathology? Int J Mol Sci 2021; 22:8769. [PMID: 34445475 PMCID: PMC8395727 DOI: 10.3390/ijms22168769] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 02/07/2023] Open
Abstract
Discovered more than a century ago, Alzheimer's disease (AD) is not only still present in our societies but has also become the most common dementia, with 50 million people worldwide affected by the disease. This number is expected to double in the next generation, and no cure is currently available to slow down or stop the disease progression. Recently, some advances were made due to the approval of the aducanumab treatment by the American Food and Drug Administration. The etiology of this human-specific disease remains poorly understood, and the mechanisms of its development have not been completely clarified. Several hypotheses concerning the molecular mechanisms of AD have been proposed, but the existing studies focus primarily on the two main markers of the disease: the amyloid β peptides, whose aggregation in the brain generates amyloid plaques, and the abnormally phosphorylated tau proteins, which are responsible for neurofibrillary tangles. These protein aggregates induce neuroinflammation and neurodegeneration, which, in turn, lead to cognitive and behavioral deficits. The challenge is, therefore, to create models that best reproduce this pathology. This review aims at gathering the different existing AD models developed in vitro, in cellulo, and in vivo. Many models have already been set up, but it is necessary to identify the most relevant ones for our investigations. The purpose of the review is to help researchers to identify the most pertinent disease models, from the most often used to the most recently generated and from simple to complex, explaining their specificities and giving concrete examples.
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Affiliation(s)
- Anaïs Vignon
- INM, University of Montpellier, INSERM, 34095 Montpellier, France; (A.V.); (L.S.-P.)
| | - Lucie Salvador-Prince
- INM, University of Montpellier, INSERM, 34095 Montpellier, France; (A.V.); (L.S.-P.)
| | - Sylvain Lehmann
- INM, University of Montpellier, INSERM, CHU Montpellier, 34095 Montpellier, France;
| | - Véronique Perrier
- INM, University of Montpellier, INSERM, CNRS, 34095 Montpellier, France
| | - Joan Torrent
- INM, University of Montpellier, INSERM, 34095 Montpellier, France; (A.V.); (L.S.-P.)
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Wang S, Rao J, Yue Y, Xue C, Hu G, Qi W, Ma W, Ge H, Zhang F, Zhang X, Chen J. Altered Frequency-Dependent Brain Activation and White Matter Integrity Associated With Cognition in Characterizing Preclinical Alzheimer's Disease Stages. Front Hum Neurosci 2021; 15:625232. [PMID: 33664660 PMCID: PMC7921321 DOI: 10.3389/fnhum.2021.625232] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/06/2021] [Indexed: 01/21/2023] Open
Abstract
Background Subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI) are regarded to be at high risk of converting to Alzheimer's disease (AD). Amplitude of low-frequency fluctuations (ALFF) can reflect functional deterioration while diffusion tensor imaging (DTI) is capable of detecting white matter integrity. Our study aimed to investigate the structural and functional alterations to further reveal convergence and divergence among SCD, naMCI, and aMCI and how these contribute to cognitive deterioration. Methods We analyzed ALFF under slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) bands and white matter fiber integrity among normal controls (CN), SCD, naMCI, and aMCI groups. Correlation analyses were further utilized among paired DTI alteration, ALFF deterioration, and cognitive decline. Results For ALFF calculation, ascended ALFF values were detected in the lingual gyrus (LING) and superior frontal gyrus (SFG) within SCD and naMCI patients, respectively. Descended ALFF values were presented mainly in the LING, SFG, middle frontal gyrus, and precuneus in aMCI patients compared to CN, SCD, and naMCI groups. For DTI analyses, white matter alterations were detected within the uncinate fasciculus (UF) in aMCI patients and within the superior longitudinal fasciculus (SLF) in naMCI patients. SCD patients presented alterations in both fasciculi. Correlation analyses revealed that the majority of these structural and functional alterations were associated with complicated cognitive decline. Besides, UF alterations were correlated with ALFF deterioration in the SFG within aMCI patients. Conclusions SCD shares structurally and functionally deteriorative characteristics with aMCI and naMCI, and tends to convert to either of them. Furthermore, abnormalities in white matter fibers may be the structural basis of abnormal brain activation in preclinical AD stages. Combined together, it suggests that structural and functional integration may characterize the preclinical AD progression.
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Affiliation(s)
- Siyu Wang
- Institute of Neuropsychiatry, The Affiliated Brain Hospital of Nanjing Medical University, Fourth Clinical College of Nanjing Medical University, Nanjing, China.,Fourth Clinical College of Nanjing Medical University, Nanjing, China
| | - Jiang Rao
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China.,Department of Rehabilitation, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Yingying Yue
- Department of Psychosomatics and Psychiatry, The Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Chen Xue
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China.,Department of Radiology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Guanjie Hu
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China
| | - Wenzhang Qi
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China.,Department of Radiology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Wenying Ma
- Department of Neurology, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Honglin Ge
- Institute of Brain Functional Imaging, Nanjing Medical University, Nanjing, China
| | - Fuquan Zhang
- Department of Psychiatry, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Xiangrong Zhang
- Fourth Clinical College of Nanjing Medical University, Nanjing, China.,Department of Psychiatry, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Jiu Chen
- Institute of Neuropsychiatry, The Affiliated Brain Hospital of Nanjing Medical University, Fourth Clinical College of Nanjing Medical University, Nanjing, China.,Fourth Clinical College of Nanjing Medical University, Nanjing, China
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19
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Cellular senescence and failure of myelin repair in multiple sclerosis. Mech Ageing Dev 2020; 192:111366. [DOI: 10.1016/j.mad.2020.111366] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/10/2020] [Accepted: 09/23/2020] [Indexed: 01/10/2023]
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20
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Angeli S, Kousiappa I, Stavrou M, Sargiannidou I, Georgiou E, Papacostas SS, Kleopa KA. Altered Expression of Glial Gap Junction Proteins Cx43, Cx30, and Cx47 in the 5XFAD Model of Alzheimer's Disease. Front Neurosci 2020; 14:582934. [PMID: 33117125 PMCID: PMC7575794 DOI: 10.3389/fnins.2020.582934] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/14/2020] [Indexed: 11/13/2022] Open
Abstract
Glial gap junction proteins, called connexins (Cxs), form gap junctions in the central nervous system (CNS) to allow the bidirectional cytosolic exchange of molecules between adjacent cells. Their involvement in inheritable diseases and the use of experimental animal models that closely mimic such diseases revealed the critical role of glial GJs in myelination and homeostasis. Cxs are also implicated in acquired demyelinating disorders, such as Multiple Sclerosis (MS) and Alzheimer's disease (AD). Animal and human studies have revealed a role of the astrocytic Cx43 in the progression of AD but the role of Cx47, which is the main partner of Cx43 in the astrocyte-oligodendrocyte GJs is still unknown. The aim of this study was to investigate the astrocytic connexins, Cx43 and Cx30 in relation to oligodendrocytic Cx47 in the cortex and thalamus of the 5XFAD mouse model of AD. The model was characterized by increased Aβ deposition, gliosis, neuronal loss, and memory impairment. Compared to wild-type mice, Cx43 and Cx30 showed increased immunoreactivity in older 5XFAD mice, reflecting astrogliosis, while Cx47 immunoreactivity was reduced. Moreover, Cx47 GJ plaques showed reduced colocalization with Cx43 plaques. Oligodendrocyte precursor cells (OPCs) and mature oligodendrocyte populations were also depleted, and myelin deficits were observed. Our findings indicate reduced astrocyte-oligodendrocyte gap junction connectivity and possibly a shift in Cx43 expression toward astrocyte-astrocyte gap junctions and/or hemichannels, that could impair oligodendrocyte homeostasis and myelination. However, other factors, such as Aβ toxicity, could directly affect oligodendrocyte survival in AD. Our study provides evidence that Cxs might have implications in the progression of AD, although the role of oligodendrocyte Cxs in AD requires further investigation.
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Affiliation(s)
- Stella Angeli
- Neurobiology Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Ioanna Kousiappa
- Neurobiology Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Marios Stavrou
- Department of Electrical and Computer Engineering, Faculty of Engineering, University of Cyprus, Nicosia, Cyprus
| | - Irene Sargiannidou
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Elena Georgiou
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Savvas S. Papacostas
- Neurobiology Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
- Dementia and Cognitive Disorders Center, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Medical School, University of Nicosia, Nicosia, Cyprus
| | - Kleopas A. Kleopa
- Cyprus School of Molecular Medicine, Nicosia, Cyprus
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Center for Neuromuscular disorders, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Center for Multiple Sclerosis and Related Disorders, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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21
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Papadopoulos D, Magliozzi R, Mitsikostas DD, Gorgoulis VG, Nicholas RS. Aging, Cellular Senescence, and Progressive Multiple Sclerosis. Front Cell Neurosci 2020; 14:178. [PMID: 32694983 PMCID: PMC7338849 DOI: 10.3389/fncel.2020.00178] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is one of the most important risk factors for the development of several neurodegenerative diseases including progressive multiple sclerosis (MS). Cellular senescence (CS) is a key biological process underlying aging. Several stressors associated with aging and MS pathology, such as oxidative stress, mitochondrial dysfunction, cytokines and replicative exhaustion are known triggers of cellular senescence. Senescent cells exhibit stereotypical metabolic and functional changes, which include cell-cycle arrest and acquiring a pro-inflammatory phenotype secreting cytokines, growth factors, metalloproteinases and reactive oxygen species. They accumulate with aging and can convert neighboring cells to senescence in a paracrine manner. In MS, accelerated cellular senescence may drive disease progression by promoting chronic non-remitting inflammation, loss or altered immune, glial and neuronal function, failure of remyelination, impaired blood-brain barrier integrity and ultimately neurodegeneration. Here we discuss the evidence linking cellular senescence to the pathogenesis of MS and the putative role of senolytic and senomorphic agents as neuroprotective therapies in tackling disease progression.
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Affiliation(s)
- Dimitrios Papadopoulos
- Molecular Carcinogenesis Group, Laboratory of Histology and Embryology, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Roberta Magliozzi
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Dimos D Mitsikostas
- First Department of Neurology, Aeginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Vassilis G Gorgoulis
- Molecular Carcinogenesis Group, Laboratory of Histology and Embryology, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Richard S Nicholas
- Department of Neuroinflammation and Neurodegeneration, Faculty of Medicine, Imperial College London, London, United Kingdom.,Department of Visual Neuroscience, Faculty of Brain Sciences, Institute of Ophthalmology, University College London, London, United Kingdom
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22
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Ferreira S, Pitman KA, Wang S, Summers BS, Bye N, Young KM, Cullen CL. Amyloidosis is associated with thicker myelin and increased oligodendrogenesis in the adult mouse brain. J Neurosci Res 2020; 98:1905-1932. [PMID: 32557778 PMCID: PMC7540704 DOI: 10.1002/jnr.24672] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/03/2020] [Accepted: 05/25/2020] [Indexed: 12/15/2022]
Abstract
In Alzheimer's disease, amyloid plaque formation is associated with the focal death of oligodendrocytes and soluble amyloid β impairs the survival of oligodendrocytes in vitro. However, the response of oligodendrocyte progenitor cells (OPCs) to early amyloid pathology remains unclear. To explore this, we performed a histological, electrophysiological, and behavioral characterization of transgenic mice expressing a pathological form of human amyloid precursor protein (APP), containing three single point mutations associated with the development of familial Alzheimer's disease (PDGFB‐APPSw.Ind, also known as J20 mice). PDGFB‐APPSw.Ind transgenic mice had impaired survival from weaning, were hyperactive by 2 months of age, and developed amyloid plaques by 6 months of age, however, their spatial memory remained intact over this time course. Hippocampal OPC density was normal in P60‐P180 PDGFB‐APPSw.Ind transgenic mice and, by performing whole‐cell patch‐clamp electrophysiology, we found that their membrane properties, including their response to kainate (100 µM), were largely normal. However, by P100, the response of hippocampal OPCs to GABA was elevated in PDGFB‐APPSw.Ind transgenic mice. We also found that the nodes of Ranvier were shorter, the paranodes longer, and the myelin thicker for hippocampal axons in young adult PDGFB‐APPSw.Ind transgenic mice compared with wildtype littermates. Additionally, oligodendrogenesis was normal in young adulthood, but increased in the hippocampus, entorhinal cortex, and fimbria of PDGFB‐APPSw.Ind transgenic mice as pathology developed. As the new oligodendrocytes were not associated with a change in total oligodendrocyte number, these cells are likely required for cell replacement.
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Affiliation(s)
- Solène Ferreira
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Shiwei Wang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Benjamin S Summers
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Nicole Bye
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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23
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Disruption of oligodendrocyte progenitor cells is an early sign of pathology in the triple transgenic mouse model of Alzheimer's disease. Neurobiol Aging 2020; 94:130-139. [PMID: 32619874 PMCID: PMC7453384 DOI: 10.1016/j.neurobiolaging.2020.05.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 01/06/2023]
Abstract
There is increasing evidence that myelin disruption is related to cognitive decline in Alzheimer's disease (AD). In the CNS, myelin is produced by oligodendrocytes, which are generated throughout life by adult oligodendrocyte progenitor cells (OPCs), also known as NG2-glia. To address whether alterations in myelination are related to age-dependent changes in OPCs, we analyzed NG2 and myelin basic protein (MBP) immunolabelling in the hippocampus of 3×Tg-AD mice at 6 and 24 months of age, compared with non-Tg age-matched controls. There was an age-related decrease in MBP immunostaining and OPC density, together with a decline in the number of OPC sister cells, a measure of OPC replication. Notably, the loss of myelin and OPC sister cells occurred earlier at 6 months in 3xTg-AD, suggesting accelerated aging, although there was not a concomitant decline in OPC numbers at this age, suggesting the observed changes in myelin were not a consequence of replicative exhaustion, but possibly of OPC disruption or senescence. In line with this, a key finding is that compared to age-match controls, OPC displayed marked morphological atrophy at 6 months in 3xTg-AD followed by morphological hypertrophy at 24 months, as deduced from significant changes in total cell surface area, total cell volume, somata volume and branching of main processes. Moreover, we show that hypertrophic OPCs surround and infiltrate amyloid-β (Aβ) plaques, a key pathological hallmark of AD. The results indicate that OPCs undergo complex age-related remodeling in the hippocampus of the 3xTg-AD mouse model. We conclude that OPC disruption is an early pathological sign in AD and is a potential factor in accelerated myelin loss and cognitive decline. Life-long generation of myelin is the function of adult oligodendrocyte progenitor cells (OPCs). Age-related loss of myelin is accelerated in the 3xTg-AD mouse model of Alzheimer's disease (AD). OPCs are disrupted at an early stage of 3xTg-AD. Dysregulation of OPC and myelin loss are important biomarkers for AD-like pathology.
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24
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Fontana IC, Zimmer AR, Rocha AS, Gosmann G, Souza DO, Lourenco MV, Ferreira ST, Zimmer ER. Amyloid-β oligomers in cellular models of Alzheimer's disease. J Neurochem 2020; 155:348-369. [PMID: 32320074 DOI: 10.1111/jnc.15030] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/21/2020] [Accepted: 04/17/2020] [Indexed: 12/22/2022]
Abstract
Amyloid-β (Aβ) dysmetabolism is tightly associated with pathological processes in Alzheimer's disease (AD). Currently, it is thought that, in addition to Aβ fibrils that give rise to plaque formation, Aβ aggregates into non-fibrillar soluble oligomers (AβOs). Soluble AβOs have been extensively studied for their synaptotoxic and neurotoxic properties. In this review, we discuss physicochemical properties of AβOs and their impact on different brain cell types in AD. Additionally, we summarize three decades of studies with AβOs, providing a compelling bulk of evidence regarding cell-specific mechanisms of toxicity. Cellular models may lead us to a deeper understanding of the detrimental effects of AβOs in neurons and glial cells, putatively shedding light on the development of innovative therapies for AD.
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Affiliation(s)
- Igor C Fontana
- Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.,Graduate Program in Biological Sciences: Biochemistry, UFRGS, Porto Alegre, Brazil
| | - Aline R Zimmer
- Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Andreia S Rocha
- Graduate Program in Biological Sciences: Biochemistry, UFRGS, Porto Alegre, Brazil
| | - Grace Gosmann
- Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Diogo O Souza
- Graduate Program in Biological Sciences: Biochemistry, UFRGS, Porto Alegre, Brazil.,Department of Biochemistry, UFRGS, Porto Alegre, Brazil
| | - Mychael V Lourenco
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sergio T Ferreira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Eduardo R Zimmer
- Graduate Program in Biological Sciences: Biochemistry, UFRGS, Porto Alegre, Brazil.,Department of Pharmacology, UFRGS, Porto Alegre, Brazil.,Graduate Program in Biological Sciences: Pharmacology and Therapeutics,, UFRGS, Porto Alegre, Brazil
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25
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Al-Janabi OM, Brown CA, Bahrani AA, Abner EL, Barber JM, Gold BT, Goldstein LB, Murphy RR, Nelson PT, Johnson NF, Shaw LM, Smith CD, Trojanowski JQ, Wilcock DM, Jicha GA. Distinct White Matter Changes Associated with Cerebrospinal Fluid Amyloid-β1-42 and Hypertension. J Alzheimers Dis 2019; 66:1095-1104. [PMID: 30400099 DOI: 10.3233/jad-180663] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults. OBJECTIVE To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations. METHODS Clinical measures of cerebrovascular disease risk were collected from 62 participants in University of Kentucky Alzheimer's Disease Center studies who also had cerebrospinal fluid (CSF) sampling and MRI brain scans. CSF Aβ1-42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess WM macro- and microstructural properties. Linear regression analyses were used to assess the relationships among WM alterations, cerebrovascular disease risk, and AD pathology. Voxelwise analyses were performed to examine spatial patterns of WM alteration associated with each pathology. RESULTS HTN and CSF Aβ1-42 levels were each associated with white matter hyperintensities (WMH). Also, CSF Aβ1-42 levels were associated with alterations in normal appearing white matter fractional anisotropy (NAWM-FA), whereas HTN was marginally associated with alterations in NAWM-FA. Linear regression analyses demonstrated significant main effects of HTN and CSF Aβ1-42 on WMH volume, but no significant HTN×CSF Aβ1-42 interaction. Furthermore, voxelwise analyses showed unique patterns of WM alteration associated with hypertension and CSF Aβ1-42. CONCLUSION Associations of HTN and lower CSF Aβ1-42 with WM alteration were statistically and spatially distinct, suggesting independent rather than synergistic effects. Considering such spatial distributions may improve diagnostic accuracy to address each underlying pathology.
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Affiliation(s)
- Omar M Al-Janabi
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Behavioral Science, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Christopher A Brown
- Departments of Neuroscience, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Ahmed A Bahrani
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Biomedical Engineering, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Erin L Abner
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Epidemiology and Biostatistics, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Justin M Barber
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Brian T Gold
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Neuroscience, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Larry B Goldstein
- Departments of Neurology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Ronan R Murphy
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Neurology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Pathology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Nathan F Johnson
- Departments of Rehabilitation Science, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Leslie M Shaw
- Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Charles D Smith
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Neurology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - John Q Trojanowski
- Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Donna M Wilcock
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Physiology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Behavioral Science, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA.,Departments of Neurology, University of Kentucky Colleges of Medicine, Public Health, Health Sciences and Engineering Lexington, KY, USA
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26
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Brown CA, Schmitt FA, Smith CD, Gold BT. Distinct patterns of default mode and executive control network circuitry contribute to present and future executive function in older adults. Neuroimage 2019; 195:320-332. [PMID: 30953834 PMCID: PMC6536351 DOI: 10.1016/j.neuroimage.2019.03.073] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/16/2019] [Accepted: 03/30/2019] [Indexed: 11/26/2022] Open
Abstract
Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline and/or average annual change in composite ΔEF scores over the three-year follow-up period. Results demonstrated that low DMN deactivation, high ECN activation and WMH burden were the main predictors of EF scores at baseline. In contrast, poor DMN and ECN WM microstructure and higher AD pathology predicted greater annual decline in EF scores. Subsequent mediation analysis demonstrated that DMN WM microstructure uniquely mediated the relationship between AD pathology and ΔEF. These results suggest that functional activation patterns within the DMN and ECN and WMHs contribute to baseline EF while structural connectivity within these networks impact longitudinal EF performance in older adults.
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Affiliation(s)
- Christopher A Brown
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
| | - Frederick A Schmitt
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA; Department of Neurology, University of Kentucky, Lexington, KY, 40536, USA; Department of Psychiatry, University of Kentucky, Lexington, KY, 40536, USA
| | - Charles D Smith
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA; Department of Neurology, University of Kentucky, Lexington, KY, 40536, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Brian T Gold
- Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, 40536, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, 40536, USA.
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27
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Quintela-López T, Ortiz-Sanz C, Serrano-Regal MP, Gaminde-Blasco A, Valero J, Baleriola J, Sánchez-Gómez MV, Matute C, Alberdi E. Aβ oligomers promote oligodendrocyte differentiation and maturation via integrin β1 and Fyn kinase signaling. Cell Death Dis 2019; 10:445. [PMID: 31171765 PMCID: PMC6554322 DOI: 10.1038/s41419-019-1636-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/17/2019] [Accepted: 05/08/2019] [Indexed: 12/13/2022]
Abstract
Alzheimer´s disease (AD) is characterized by a progressive cognitive decline that correlates with the levels of amyloid β-peptide (Aβ) oligomers. Strong evidences connect changes of oligodendrocyte function with the onset of neurodegeneration in AD. However, the mechanisms controlling oligodendrocyte responses to Aβ are still elusive. Here, we tested the role of Aβ in oligodendrocyte differentiation, maturation, and survival in isolated oligodendrocytes and in organotypic cerebellar slices. We found that Aβ peptides specifically induced local translation of 18.5-kDa myelin basic protein (MBP) isoform in distal cell processes concomitant with an increase of process complexity of MBP-expressing oligodendrocytes. Aβ oligomers required integrin β1 receptor, Src-family kinase Fyn and Ca2+/CaMKII as effectors to modulate MBP protein expression. The pharmacological inhibition of Fyn kinase also attenuated oligodendrocyte differentiation and survival induced by Aβ oligomers. Similarly, using ex vivo organotypic cerebellar slices Aβ promoted MBP upregulation through Fyn kinase, and modulated oligodendrocyte population dynamics by inducing cell proliferation and differentiation. Importantly, application of Aβ to cerebellar organotypic slices enhanced remyelination and oligodendrocyte lineage recovery in lysolecithin (LPC)-induced demyelination. These data reveal an important role of Aβ in oligodendrocyte lineage function and maturation, which may be relevant to AD pathogenesis.
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Affiliation(s)
- Tania Quintela-López
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carolina Ortiz-Sanz
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Mari Paz Serrano-Regal
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Adhara Gaminde-Blasco
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Jimena Baleriola
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain.,Department of Cell Biology and Histology, UPV/EHU, Leioa, 48940, Spain
| | - Maria Victoria Sánchez-Gómez
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carlos Matute
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
| | - Elena Alberdi
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
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28
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McCanney GA, McGrath MA, Otto TD, Burchmore R, Yates EA, Bavington CD, Willison HJ, Turnbull JE, Barnett SC. Low sulfated heparins target multiple proteins for central nervous system repair. Glia 2019; 67:668-687. [PMID: 30585359 PMCID: PMC6492281 DOI: 10.1002/glia.23562] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/05/2018] [Accepted: 10/17/2018] [Indexed: 01/01/2023]
Abstract
The lack of endogenous repair following spinal cord injury (SCI) accounts for the frequent permanent deficits for which effective treatments are absent. Previously, we demonstrated that low sulfated modified heparin mimetics (LS-mHeps) attenuate astrocytosis, suggesting they may represent a novel therapeutic approach. mHeps are glycomolecules with structural similarities to resident heparan sulfates (HS), which modulate cell signaling by both sequestering ligands, and acting as cofactors in the formation of ligand-receptor complexes. To explore whether mHeps can affect the myelination and neurite outgrowth necessary for repair after SCI, we created lesioned or demyelinated neural cell co-cultures and exposed them with a panel of mHeps with varying degrees and positions of their sulfate moieties. LS-mHep7 enhanced neurite outgrowth and myelination, whereas highly sulfated mHeps (HS-mHeps) had attenuating effects. LS-mHeps had no effects on myelination or neurite extension in developing, uninjured myelinating cultures, suggesting they might exert their proregenerating effects by modulating or sequestering inhibitory factors secreted after injury. To investigate this, we examined conditioned media from cultures using chemokine arrays and conducted an unbiased proteomics approach by applying TMT-LC/MS to mHep7 affinity purified conditioned media from these cultures. Multiple protein factors reported to play a role in damage or repair mechanisms were identified, including amyloid betaA4. Amyloid beta peptide (1-42) was validated as an important candidate by treating myelination cultures and shown to inhibit myelination. Thus, we propose that LS-mHeps exert multiple beneficial effects on mechanisms supporting enhanced repair, and represent novel candidates as therapeutics for CNS damage.
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Affiliation(s)
- George A. McCanney
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
| | - Michael A. McGrath
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
| | - Thomas D. Otto
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
| | - Richard Burchmore
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
| | - Edwin A. Yates
- Department of BiochemistryInstitute of Integrative Biology, University of LiverpoolLiverpoolUK
| | - Charles D. Bavington
- GlycoMar Limited, European Centre for Marine Biotechnology, Dunstaffnage Marine LaboratoryObanArgyllScotland, UK
| | - Hugh J. Willison
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
| | - Jeremy E. Turnbull
- Department of BiochemistryInstitute of Integrative Biology, University of LiverpoolLiverpoolUK
| | - Susan C. Barnett
- Institute of Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of GlasgowGlasgowUK
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Nirzhor SSR, Khan RI, Neelotpol S. The Biology of Glial Cells and Their Complex Roles in Alzheimer's Disease: New Opportunities in Therapy. Biomolecules 2018; 8:biom8030093. [PMID: 30201881 PMCID: PMC6164719 DOI: 10.3390/biom8030093] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/28/2018] [Accepted: 09/06/2018] [Indexed: 01/01/2023] Open
Abstract
Even though Alzheimer's disease (AD) is of significant interest to the scientific community, its pathogenesis is very complicated and not well-understood. A great deal of progress has been made in AD research recently and with the advent of these new insights more therapeutic benefits may be identified that could help patients around the world. Much of the research in AD thus far has been very neuron-oriented; however, recent studies suggest that glial cells, i.e., microglia, astrocytes, oligodendrocytes, and oligodendrocyte progenitor cells (NG2 glia), are linked to the pathogenesis of AD and may offer several potential therapeutic targets against AD. In addition to a number of other functions, glial cells are responsible for maintaining homeostasis (i.e., concentration of ions, neurotransmitters, etc.) within the central nervous system (CNS) and are crucial to the structural integrity of neurons. This review explores the: (i) role of glial cells in AD pathogenesis; (ii) complex functionalities of the components involved; and (iii) potential therapeutic targets that could eventually lead to a better quality of life for AD patients.
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Wang SS, Zhang Z, Zhu TB, Chu SF, He WB, Chen NH. Myelin injury in the central nervous system and Alzheimer's disease. Brain Res Bull 2018; 140:162-168. [PMID: 29730417 DOI: 10.1016/j.brainresbull.2018.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/18/2018] [Accepted: 05/02/2018] [Indexed: 12/20/2022]
Abstract
Myelin is a membrane wrapped around the axon of the nerve cell, which is composed of the mature oligodendrocytes. The role of myelin is to insulate and prevent the nerve electrical impulses from the axon of the neurons to the axons of the other neurons, which is essential for the proper functioning of the nervous system. Minor changes in myelin thickness could lead to substantial changes in conduction speed and may thus alter neural circuit function. Demyelination is the myelin damage, which characterized by the loss of nerve sheath and the relative fatigue of the neuronal sheath and axon. Studies have shown that myelin injury may be closely related to neurodegenerative diseases and may be an early diagnostic criteria and therapeutic target. Thus this review summarizes the recent result of pathologic effect and signal pathways of myelin injury in neurodegenerative diseases, especially the Alzheimer's disease to provide new and effective therapeutic targets.
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Affiliation(s)
- Sha-Sha Wang
- School of Basic Medicine, Shanxi University of Traditional Chinese Medicine, Taiyuan 030619, China; State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Zhao Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Tian-Bi Zhu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; College of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China
| | - Shi-Feng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Wen-Bin He
- School of Basic Medicine, Shanxi University of Traditional Chinese Medicine, Taiyuan 030619, China
| | - Nai-Hong Chen
- School of Basic Medicine, Shanxi University of Traditional Chinese Medicine, Taiyuan 030619, China; State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
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31
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Brown CA, Jiang Y, Smith CD, Gold BT. Age and Alzheimer's pathology disrupt default mode network functioning via alterations in white matter microstructure but not hyperintensities. Cortex 2018; 104:58-74. [PMID: 29758374 DOI: 10.1016/j.cortex.2018.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 02/07/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023]
Abstract
The default mode network (DMN) comprises defined brain regions contributing to internally-directed thought processes. Reductions in task-induced deactivation in the DMN have been associated with increasing age and poorer executive task performance, but factors underlying these functional changes remain unclear. We investigated contributions of white matter (WM) microstructure, WM hyperintensities (WMH) and Alzheimer's pathology to age-related alterations in DMN function. Thirty-five cognitively normal older adults and 29 younger adults underwent working memory task fMRI and diffusion tensor imaging. In the older adults, we measured cerebrospinal fluid tau and Aβ42 (markers of AD pathology), and WMH on FLAIR imaging (marker of cerebrovascular disease). We identified a set of regions showing DMN deactivation and a set of inter-connecting WM tracts (DMN-WM) common to both age groups. There were negative associations between DMN deactivation and task performance in older adults, consistent with previous studies. Decreased DMN deactivation was associated with AD pathology and WM microstructure but not with WMH volume. Mediation analyses showed that WM microstructure mediated declines in DMN deactivation associated with both aging and AD pathology. Together these results suggest that AD pathology may exert a "second-hit" on WM microstructure, over-and-above the effects of age, both contributing to diminished DMN deactivation in older adults.
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Affiliation(s)
| | - Yang Jiang
- Department of Behavioral Science, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA
| | - Charles D Smith
- Department of Neurology, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA
| | - Brian T Gold
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Magnetic Resonance Imaging and Spectroscopy Center, University of Kentucky, Lexington, KY, USA.
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32
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Sun J, Zhou H, Bai F, Zhang Z, Ren Q. Remyelination: A Potential Therapeutic Strategy for Alzheimer's Disease? J Alzheimers Dis 2018; 58:597-612. [PMID: 28453483 DOI: 10.3233/jad-170036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Myelin is a lipid-rich multilamellar membrane that wraps around long segments of neuronal axons and it increases the conduction of action potentials, transports the necessary trophic support to the neuronal axons, and reduces the energy consumed by the neuronal axons. Together with axons, myelin is a prerequisite for the higher functions of the central nervous system and complex forms of network integration. Myelin impairments have been suggested to lead to neuronal dysfunction and cognitive decline. Accumulating evidence, including brain imaging and postmortem and genetic association studies, has implicated myelin impairments in Alzheimer's disease (AD). Increasing data link myelin impairments with amyloid-β (Aβ) plaques and tau hyperphosphorylation, which are both present in patients with AD. Moreover, aging and apolipoprotein E (ApoE) may be involved in the myelin impairments observed in patients with AD. Decreased neuronal activity, increased Aβ levels, and inflammation further damage myelin in patients with AD. Furthermore, treatments that promote myelination contribute to the recovery of neuronal function and improve cognition. Therefore, strategies targeting myelin impairment may provide therapeutic opportunities for patients with AD.
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Nasrabady SE, Rizvi B, Goldman JE, Brickman AM. White matter changes in Alzheimer's disease: a focus on myelin and oligodendrocytes. Acta Neuropathol Commun 2018; 6:22. [PMID: 29499767 PMCID: PMC5834839 DOI: 10.1186/s40478-018-0515-3] [Citation(s) in RCA: 366] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 02/08/2018] [Indexed: 12/22/2022] Open
Abstract
Alzheimer’s disease (AD) is conceptualized as a progressive consequence of two hallmark pathological changes in grey matter: extracellular amyloid plaques and neurofibrillary tangles. However, over the past several years, neuroimaging studies have implicated micro- and macrostructural abnormalities in white matter in the risk and progression of AD, suggesting that in addition to the neuronal pathology characteristic of the disease, white matter degeneration and demyelination may be also important pathophysiological features. Here we review the evidence for white matter abnormalities in AD with a focus on myelin and oligodendrocytes, the only source of myelination in the central nervous system, and discuss the relationship between white matter changes and the hallmarks of Alzheimer’s disease. We review several mechanisms such as ischemia, oxidative stress, excitotoxicity, iron overload, Aβ toxicity and tauopathy, which could affect oligodendrocytes. We conclude that white matter abnormalities, and in particular myelin and oligodendrocytes, could be mechanistically important in AD pathology and could be potential treatment targets.
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Zhan X, Stamova B, Sharp FR. Lipopolysaccharide Associates with Amyloid Plaques, Neurons and Oligodendrocytes in Alzheimer's Disease Brain: A Review. Front Aging Neurosci 2018. [PMID: 29520228 PMCID: PMC5827158 DOI: 10.3389/fnagi.2018.00042] [Citation(s) in RCA: 206] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
This review proposes that lipopolysaccharide (LPS, found in the wall of all Gram-negative bacteria) could play a role in causing sporadic Alzheimer’s disease (AD). This is based in part upon recent studies showing that: Gram-negative E. coli bacteria can form extracellular amyloid; bacterial-encoded 16S rRNA is present in all human brains with over 70% being Gram-negative bacteria; ultrastructural analyses have shown microbes in erythrocytes of AD patients; blood LPS levels in AD patients are 3-fold the levels in control; LPS combined with focal cerebral ischemia and hypoxia produced amyloid-like plaques and myelin injury in adult rat cortex. Moreover, Gram-negative bacterial LPS was found in aging control and AD brains, though LPS levels were much higher in AD brains. In addition, LPS co-localized with amyloid plaques, peri-vascular amyloid, neurons, and oligodendrocytes in AD brains. Based upon the postulate LPS caused oligodendrocyte injury, degraded Myelin Basic Protein (dMBP) levels were found to be much higher in AD compared to control brains. Immunofluorescence showed that the dMBP co-localized with β amyloid (Aβ) and LPS in amyloid plaques in AD brain, and dMBP and other myelin molecules were found in the walls of vesicles in periventricular White Matter (WM). These data led to the hypothesis that LPS acts on leukocyte and microglial TLR4-CD14/TLR2 receptors to produce NFkB mediated increases of cytokines which increase Aβ levels, damage oligodendrocytes and produce myelin injury found in AD brain. Since Aβ1–42 is also an agonist for TLR4 receptors, this could produce a vicious cycle that accounts for the relentless progression of AD. Thus, LPS, the TLR4 receptor complex, and Gram-negative bacteria might be treatment or prevention targets for sporadic AD.
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Affiliation(s)
- Xinhua Zhan
- Department of Neurology, MIND Institute, University of California, Davis, Davis, CA, United States
| | - Boryana Stamova
- Department of Neurology, MIND Institute, University of California, Davis, Davis, CA, United States
| | - Frank R Sharp
- Department of Neurology, MIND Institute, University of California, Davis, Davis, CA, United States
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35
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Valny M, Honsa P, Waloschkova E, Matuskova H, Kriska J, Kirdajova D, Androvic P, Valihrach L, Kubista M, Anderova M. A single-cell analysis reveals multiple roles of oligodendroglial lineage cells during post-ischemic regeneration. Glia 2018; 66:1068-1081. [DOI: 10.1002/glia.23301] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 01/07/2018] [Accepted: 01/16/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Martin Valny
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
- 2nd Faculty of Medicine; Charles University; Prague Czech Republic
| | - Pavel Honsa
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Eliska Waloschkova
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Hana Matuskova
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Jan Kriska
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
- 2nd Faculty of Medicine; Charles University; Prague Czech Republic
| | - Denisa Kirdajova
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
- 2nd Faculty of Medicine; Charles University; Prague Czech Republic
| | - Peter Androvic
- Laboratory of Gene Expression; Institute of Biotechnology, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Lukas Valihrach
- Laboratory of Gene Expression; Institute of Biotechnology, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Mikael Kubista
- Laboratory of Gene Expression; Institute of Biotechnology, Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Miroslava Anderova
- Department of Cellular Neurophysiology; Institute of Experimental Medicine, Academy of Sciences of the Czech Republic; Prague Czech Republic
- 2nd Faculty of Medicine; Charles University; Prague Czech Republic
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Horiuchi M, Suzuki-Horiuchi Y, Akiyama T, Itoh A, Pleasure D, Carstens E, Itoh T. Differing intrinsic biological properties between forebrain and spinal oligodendroglial lineage cells. J Neurochem 2017; 142:378-391. [PMID: 28512742 DOI: 10.1111/jnc.14074] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 12/21/2022]
Abstract
Differentiation of oligodendroglial progenitor cells (OPCs) into myelinating oligodendrocytes is known to be regulated by the microenvironment where they differentiate. However, current research has not verified whether or not oligodendroglial lineage cells (OLCs) derived from different anatomical regions of the central nervous system (CNS) respond to microenvironmental cues in the same manner. Here, we isolated pure OPCs from rat neonatal forebrain (FB) and spinal cord (SC) and compared their phenotypes in the same in vitro conditions. We found that although FB and SC OLCs responded differently to the same external factors; they were distinct in proliferation response to mitogens, oligodendrocyte phenotype after differentiation, and cytotoxic responses to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-type glutamate receptor-mediated excitotoxicity at immature stages of differentiation in a cell-intrinsic manner. Moreover, transcriptome analysis identified genes differentially expressed between these OPC populations, including those encoding transcription factors (TFs), cell surface molecules, and signaling molecules. Particularly, FB and SC OPCs retained the expression of FB- or SC-specific TFs, such as Foxg1 and Hoxc8, respectively, even after serial passaging in vitro. Given the essential role of these TFs in the regional identities of CNS cells along the rostrocaudal axis, our results suggest that CNS region-specific gene regulation by these TFs may cause cell-intrinsic differences in cellular responses between FB and SC OLCs to extracellular molecules. Further understanding of the regional differences among OPC populations will help to improve treatments for demyelination in different CNS regions and to facilitate the development of stem cell-derived OPCs for cell transplantation therapies for demyelination. Cover Image for this issue: doi. 10.1111/jnc.13809.
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Affiliation(s)
- Makoto Horiuchi
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yoko Suzuki-Horiuchi
- Department of Dermatology, Institute of Regenerative Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Tasuku Akiyama
- Temple Itch Center, Department of Dermatology, Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Aki Itoh
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, California, USA.,Department of Neurology, School of Medicine, University of California, Sacramento, California, USA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, California, USA.,Department of Neurology, School of Medicine, University of California, Sacramento, California, USA
| | - Earl Carstens
- Department of Neurobiology, Physiology & Behavior, University of California, Davis, California, USA
| | - Takayuki Itoh
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, California, USA.,Department of Neurology, School of Medicine, University of California, Sacramento, California, USA
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You F, Li Q, Jin G, Zheng Y, Chen J, Yang H. Genistein protects against Aβ 25-35 induced apoptosis of PC12 cells through JNK signaling and modulation of Bcl-2 family messengers. BMC Neurosci 2017; 18:12. [PMID: 28081713 PMCID: PMC5234099 DOI: 10.1186/s12868-016-0329-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/27/2016] [Indexed: 01/22/2023] Open
Abstract
Background Deposition of aggregated amyloid beta (Aβ) protein is hallmark of Alzheimer’s disease, leading to dysfunction and apoptosis of neurons. The isoflavone phytoestrogen compound genistein (Gen) exerts a significant protective effect against Aβ25–35 induced neurotoxicity and mitochondrial damage in rat pheochromocytoma (PC12) cells. However, the mechanisms underlying Gen’s rescue remain elusive. Therefore we endeavored to research further the molecular mechanisms underlying Gen’s inhibition of Aβ25–35 induced apoptosis of neurons. Results We found that Gen dramatically suppressed the activation by Aβ25–35 of p-c-Jun N-terminal kinase (p-JNK), and also inhibited the JNK-dependent decreased of Bcl-w and increased of Bim. Furthermore, Gen significantly reduced the cytoplasmic concentrations of cytochrome c and Smac protein as well as caspase-3 activity. Additionally, pretreatment with JNK inhibitor SP600125 effectively suppressed Aβ25–35 induced PC12 cell cytotoxicity. Conclusion Taken together, the results suggested that Gen protects PC12 cells from Aβ25–35 induced neurotoxicity by interfering with p-JNK activation, thus attenuating the JNK-dependent apoptosis through the mitochondrial pathway. These findings constitute novel insights into the pathway for Aβ25–35 toxicity, and the neuroprotective action of Gen. Electronic supplementary material The online version of this article (doi:10.1186/s12868-016-0329-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fuling You
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Qiao Li
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Guifang Jin
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Yaojie Zheng
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Jingrong Chen
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China
| | - Hong Yang
- Basic Medical College, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China.
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Ezra A, Rabinovich-Nikitin I, Rabinovich-Toidman P, Solomon B. Multifunctional Effect of Human Serum Albumin Reduces Alzheimer's Disease Related Pathologies in the 3xTg Mouse Model. J Alzheimers Dis 2016; 50:175-88. [PMID: 26682687 DOI: 10.3233/jad-150694] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Alzheimer's disease (AD), the prevalent dementia in the elderly, involves many related and interdependent pathologies that manifests simultaneously, eventually leading to cognitive impairment and death. No treatment is currently available; however, an agent addressing several key pathologies simultaneously has a better therapeutic potential. Human serum albumin (HSA) is a highly versatile protein, harboring multifunctional properties that are relevant to key pathologies underlying AD. This study provides insight into the mechanism for HSA's therapeutic effect. In vivo, a myriad of beneficial effects were observed by pumps infusing HSA intracerebroventricularly, for the first time in an AD 3xTg mice model. A significant effect on amyloid-β (Aβ) pathology was observed. Aβ1-42, soluble oligomers, and total plaque area were reduced. Neuroblastoma SHSY5Y cell line confirmed that the reduction in Aβ1-42 toxicity was due to direct binding rather than other properties of HSA. Total and hyperphosphorylated tau were reduced along with an increase in tubulin, suggesting increased microtubule stability. HSA treatment also reduced brain inflammation, affecting both astrocytes and microglia markers. Finally, evidence for blood-brain barrier and myelin integrity repair was observed. These multidimensional beneficial effects of intracranial administrated HSA, together or individually, contributed to an improvement in cognitive tests, suggesting a non-immune or Aβ efflux dependent means for treating AD.
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Echeverria V, Yarkov A, Aliev G. Positive modulators of the α7 nicotinic receptor against neuroinflammation and cognitive impairment in Alzheimer's disease. Prog Neurobiol 2016; 144:142-57. [DOI: 10.1016/j.pneurobio.2016.01.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 11/07/2015] [Accepted: 01/06/2016] [Indexed: 01/08/2023]
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40
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Kincses ZT, Király A, Veréb D, Vécsei L. Structural Magnetic Resonance Imaging Markers of Alzheimer's Disease and Its Retranslation to Rodent Models. J Alzheimers Dis 2016; 47:277-90. [PMID: 26401552 DOI: 10.3233/jad-143195] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The importance of imaging biomarkers has been acknowledged in the diagnosis and in the follow-up of Alzheimer's disease (AD), one of the major causes of dementia. Next to the molecular biomarkers and PET imaging investigations, structural MRI approaches provide important information about the disease progression and about the pathomechanism. Furthermore,a growing body of literature retranslates these imaging biomarkers to various rodent models of the disease. The goal of this review is to provide an overview of the macro- and microstructural imaging biomarkers of AD, concentrating on atrophy measures and diffusion MRI alterations. A survey is also given of the imaging approaches used in rodent models of dementias that can promote drug development.
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Affiliation(s)
- Zsigmond Tamas Kincses
- Department of Neurology, University of Szeged, Szeged, Hungary.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - András Király
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Dániel Veréb
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - László Vécsei
- Department of Neurology, University of Szeged, Szeged, Hungary.,MTA-SZTE Neuroscience Research Group, Szeged, Hungary
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Dá Mesquita S, Ferreira AC, Sousa JC, Correia-Neves M, Sousa N, Marques F. Insights on the pathophysiology of Alzheimer's disease: The crosstalk between amyloid pathology, neuroinflammation and the peripheral immune system. Neurosci Biobehav Rev 2016; 68:547-562. [PMID: 27328788 DOI: 10.1016/j.neubiorev.2016.06.014] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 06/09/2016] [Accepted: 06/14/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, whose prevalence is growing along with the increased life expectancy. Although the accumulation and deposition of amyloid beta (Aβ) peptides in the brain is viewed as one of the pathological hallmarks of AD and underlies, at least in part, brain cell dysfunction and behavior alterations, the etiology of this neurodegenerative disease is still poorly understood. Noticeably, increased amyloid load is accompanied by marked inflammatory alterations, both at the level of the brain parenchyma and at the barriers of the brain. However, it is debatable whether the neuroinflammation observed in aging and in AD, together with alterations in the peripheral immune system, are responsible for increased amyloidogenesis, decreased clearance of Aβ out of the brain and/or the marked deficits in memory and cognition manifested by AD patients. Herein, we scrutinize some important traits of the pathophysiology of aging and AD, focusing on the interplay between the amyloidogenic pathway, neuroinflammation and the peripheral immune system.
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Affiliation(s)
- Sandro Dá Mesquita
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Ana Catarina Ferreira
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Margarida Correia-Neves
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal.
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Abstract
Extensive evidence has indicated that the breakdown of myelin is associated with Alzheimer's disease (AD) since the vulnerability of oligodendrocytes under Alzheimer's pathology easily induces the myelin breakdown and the loss of the myelin sheath which might be the initiating step in the changes of the earliest stage of AD prior to appearance of amyloid and tau pathology. Considerable research implicated that beta-amyloid (Aβ)-mediated oligodendrocyte dysfunction and myelin breakdown may be via neuroinflammation, oxidative stress and/or apoptosis. It also seems that the oligodendrocyte dysfunction is triggered by the formation of neurofibrillary tangles (NFTs) through inflammation and oxidative stress as the common pathophysiological base. Impaired repair of oligodendrocyte precursor cells (OPCs) might possibly enhance the disease progress under decreased self-healing ability from aging process and pathological factors including Aβ pathology and/or NFTs. Thus, these results have suggested that targeting oligodendrocytes may be a novel therapeutic intervention for the prevention and treatment of AD.
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Affiliation(s)
- Zhiyou Cai
- a Department of Neurology, Renmin Hospital , Hubei University of Medicine, Shiyan Renmin Hospital , Shiyan , Hubei Province , China
| | - Ming Xiao
- b Department of Anatomy , Nanjing Medical University , Nanjing , Jiangsu , China
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Oligodendroglia and Myelin in Neurodegenerative Diseases: More Than Just Bystanders? Mol Neurobiol 2015; 53:3046-3062. [PMID: 25966971 PMCID: PMC4902834 DOI: 10.1007/s12035-015-9205-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/29/2015] [Indexed: 12/01/2022]
Abstract
Oligodendrocytes, the myelinating cells of the central nervous system, mediate rapid action potential conduction and provide trophic support for axonal as well as neuronal maintenance. Their progenitor cell population is widely distributed in the adult brain and represents a permanent cellular reservoir for oligodendrocyte replacement and myelin plasticity. The recognition of oligodendrocytes, their progeny, and myelin as contributing factors for the pathogenesis and the progression of neurodegenerative disease has recently evolved shaping our understanding of these disorders. In the present review, we aim to highlight studies on oligodendrocytes and their progenitors in neurodegenerative diseases. We dissect oligodendroglial biology and illustrate evolutionary aspects in regard to their importance for neuronal functionality and maintenance of neuronal circuitries. After covering recent studies on oligodendroglia in different neurodegenerative diseases mainly in view of their function as myelinating cells, we focus on the alpha-synucleinopathy multiple system atrophy, a prototypical disorder with a well-defined oligodendroglial pathology.
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Agosta F, Dalla Libera D, Spinelli EG, Finardi A, Canu E, Bergami A, Bocchio Chiavetto L, Baronio M, Comi G, Martino G, Matteoli M, Magnani G, Verderio C, Furlan R. Myeloid microvesicles in cerebrospinal fluid are associated with myelin damage and neuronal loss in mild cognitive impairment and Alzheimer disease. Ann Neurol 2014; 76:813-25. [DOI: 10.1002/ana.24235] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Federica Agosta
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Dacia Dalla Libera
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Edoardo Gioele Spinelli
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Annamaria Finardi
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Elisa Canu
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Alessandra Bergami
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | | | | | - Giancarlo Comi
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
- Vita-Salute San Raffaele University; Milan
| | - Gianvito Martino
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Michela Matteoli
- CNR Institute of Neuroscience and Department of Medical Pharmacology; Milan
- Istituto Clinico Humanitas IRCCS; Milan Italy
| | - Giuseppe Magnani
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
| | - Claudia Verderio
- CNR Institute of Neuroscience and Department of Medical Pharmacology; Milan
- Istituto Clinico Humanitas IRCCS; Milan Italy
| | - Roberto Furlan
- Division of Neuroscience, Institute of Experimental Neurology; Scientific Institute San Raffaele; Milan
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Soluble amyloid beta levels are elevated in the white matter of Alzheimer's patients, independent of cortical plaque severity. Acta Neuropathol Commun 2014; 2:83. [PMID: 25129614 PMCID: PMC4147157 DOI: 10.1186/s40478-014-0083-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/04/2014] [Indexed: 12/03/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease and the leading cause of dementia. In addition to grey matter pathology, white matter changes are now recognized as an important pathological feature in the emergence of the disease. Despite growing recognition of the importance of white matter abnormalities in the pathogenesis of AD, the causes of white matter degeneration are still unknown. While multiple studies propose Wallerian-like degeneration as the source of white matter change, others suggest that primary white matter pathology may be due, at least in part, to other mechanisms, including local effects of toxic Aβ peptides. In the current study, we investigated levels of soluble amyloid-beta (Aβ) in white matter of AD patients (n=12) compared with controls (n=10). Fresh frozen white matter samples were obtained from anterior (Brodmann area 9) and posterior (Brodmann area 1, 2 and 3) areas of post-mortem AD and control brains. ELISA was used to examine levels of soluble Aβ -42 and Aβ -40. Total cortical neuritic plaque severity rating was derived from individual ratings in the following areas of cortex: mid-frontal, superior temporal, pre-central, inferior parietal, hippocampus (CA1), subiculum, entorhinal cortex, transentorhinal cortex, inferior temporal, amygdala and basal forebrain. Compared with controls, AD samples had higher white matter levels of both soluble Aβ -42 and Aβ -40. While no regional white matter differences were found in Aβ -40, Aβ -42 levels were higher in anterior regions than in posterior regions across both groups. After statistically controlling for total cortical neuritic plaque severity, differences in both soluble Aβ -42 and Aβ -40 between the groups remained, suggesting that white matter Aβ peptides accumulate independent of overall grey matter fibrillar amyloid pathology and are not simply a reflection of overall amyloid burden. These results shed light on one potential mechanism through which white matter degeneration may occur in AD. Given that white matter degeneration may be an early marker of disease, preceding grey matter atrophy, understanding the mechanisms and risk factors that may lead to white matter loss could help to identify those at high risk and to intervene earlier in the pathogenic process.
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Sun Q, Jia N, Wang W, Jin H, Xu J, Hu H. Protective effects of astragaloside IV against amyloid beta1-42 neurotoxicity by inhibiting the mitochondrial permeability transition pore opening. PLoS One 2014; 9:e98866. [PMID: 24905226 PMCID: PMC4048237 DOI: 10.1371/journal.pone.0098866] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 05/08/2014] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial dysfunction caused by amyloid β-peptide (Aβ) plays an important role in the pathogenesis of Alzheimer disease (AD). Substantial evidence has indicated that the mitochondrial permeability transition pore (mPTP) opening is involved in Aβ-induced neuronal death and reactive oxygen species (ROS) generation. Astragaloside IV (AS-IV), one of the major active constituents of Astragalus membranaceus, has been reported as an effective anti-oxidant for treating neurodegenerative diseases. However, the molecular mechanisms still need to be clarified. In this study, we investigated whether AS-IV could prevent Aβ1-42-induced neurotoxicity in SK-N-SH cells via inhibiting the mPTP opening. The results showed that pretreatment of AS-IV significantly increased the viability of neuronal cells, reduced apoptosis, decreased the generation of intracellular reactive oxygen species (ROS) and decreased mitochondrial superoxide in the presence of Aβ1-42. In addition, pretreatment of AS-IV inhibited the mPTP opening, rescued mitochondrial membrane potential (ΔΨm), enhanced ATP generation, improved the activity of cytochrome c oxidase and blocked cytochrome c release from mitochondria in Aβ1-42 rich milieu. Moreover, pretreatment of AS-IV reduced the expression of Bax and cleaved caspase-3 and increased the expression of Bcl-2 in an Aβ1-42 rich environment. These data indicate that AS-IV prevents Aβ1-42-induced SK-N-SH cell apoptosis via inhibiting the mPTP opening and ROS generation. These results provide novel insights of AS-IV for the prevention and treatment of neurodegenerative disorders such as AD.
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Affiliation(s)
- Qinru Sun
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Ning Jia
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
- * E-mail: (NJ); (HH)
| | - Weixi Wang
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Hui Jin
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Jiehua Xu
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Haitao Hu
- Department of Human Anatomy and Histo-Embryology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
- * E-mail: (NJ); (HH)
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Nielsen HM, Ek D, Avdic U, Orbjörn C, Hansson O, Veerhuis R, Rozemuller AJM, Brun A, Minthon L, Wennström M. NG2 cells, a new trail for Alzheimer's disease mechanisms? Acta Neuropathol Commun 2013; 1:7. [PMID: 24252600 PMCID: PMC4046664 DOI: 10.1186/2051-5960-1-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 02/28/2013] [Indexed: 02/07/2023] Open
Abstract
Background Neuron Glial 2 (NG2) cells are glial cells known to serve as oligodendrocyte progenitors as well as modulators of the neuronal network. Altered NG2 cell morphology and up-regulation as well as increased shedding of the proteoglycan NG2 expressed on the cell surface have been described in rodent models of brain injury. Here we describe alterations in the human NG2 cell population in response to pathological changes characteristic of Alzheimer’s disease (AD). Results Immunohistological stainings of postmortem brain specimens from clinically diagnosed and postmortem verified AD patients and non-demented controls revealed reduced NG2 immunoreactivity as well as large numbers of NG2 positive astrocytes in individuals with high amyloid beta plaque load. Since fibrillar amyloid beta (Aβ)1-42 is the major component of AD-related senile plaques, we exposed human NG2 cells to oligomer- and fibril enriched preparations of Aβ1-42. We found that both oligomeric and fibrillar Aβ1-42 induced changes in NG2 cell morphology. Further, in vitro exposure to fibrillar Aβ1-42 decreased the NG2 concentrations in both cell lysates and supernatants. Interestingly, we also found significantly decreased levels of soluble NG2 in the cerebrospinal fluid (CSF) from clinically diagnosed AD patients compared to non-demented individuals. Additionally, the CSF NG2 levels were found to significantly correlate with the core AD biomarkers Aß1-42, T-tau and P-tau. Conclusion Our results demonstrate major alterations in the NG2 cell population in relation to AD pathology which highlights the NG2 cell population as a new attractive research target in the search for cellular mechanisms associated with AD pathogenesis. Electronic supplementary material The online version of this article (doi:10.1186/2051-5960-1-7) contains supplementary material, which is available to authorized users.
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Abstract
PURPOSE OF REVIEW Alzheimer's disease has long been primarily considered a disease of gray matter. However, convergent evidence has suggested that white matter abnormalities are also important components of Alzheimer's disease. We undertook a review of the recent findings of Alzheimer's disease related white matter aberrations identified in patients with Alzheimer's disease and using in-vitro and in-vivo models, and discuss the potential causes of white matter damage in Alzheimer's disease. In doing so, we aim to provide a renewed insight into white matter changes in Alzheimer's disease and related dementias. RECENT FINDINGS Neuroimaging studies have found that patients with preclinical Alzheimer's disease have widespread white matter abnormalities at a stage similar to those reported in Alzheimer's disease, whereas gray matter structures were relatively intact. In addition, demyelination of the white matter is reported to occur prior to the presence of amyloid-β plaques and neurofibrillary tangles in the presymptomatic stages of Alzheimer's disease. Furthermore, in a mouse model of Alzheimer's disease, axonal disease due to impaired axonal transport was shown to precede and drive downstream production and aggregation of amyloid β peptides. SUMMARY White matter abnormalities not only represent an early neuropathological event in Alzheimer's disease but may also play an important role in the pathogenesis and diagnosis of Alzheimer's disease.
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Hedden T, Mormino EC, Amariglio RE, Younger AP, Schultz AP, Becker JA, Buckner RL, Johnson KA, Sperling RA, Rentz DM. Cognitive profile of amyloid burden and white matter hyperintensities in cognitively normal older adults. J Neurosci 2012; 32:16233-42. [PMID: 23152607 PMCID: PMC3523110 DOI: 10.1523/jneurosci.2462-12.2012] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 09/10/2012] [Accepted: 09/17/2012] [Indexed: 11/21/2022] Open
Abstract
Amyloid burden and white matter hyperintensities (WMH) are two common markers of neurodegeneration present in advanced aging. Each represents a potential early indicator of an age-related neurological disorder that impacts cognition. The presence of amyloid is observed in a substantial subset of cognitively normal older adults, but the literature remains equivocal regarding whether amyloid in nondemented populations is deleterious to cognition. Similarly, WMH are detected in many nondemented older adults and there is a body of evidence indicating that WMH are associated with decreased executive function and other cognitive domains. The current study investigated amyloid burden and WMH in clinically normal older adult humans aged 65-86 (N = 168) and examined each biomarker's relation with cognitive domains of episodic memory, executive function, and speed of processing. Factors for each domain were derived from a neuropsychological battery on a theoretical basis without reference to the relation between cognition and the biomarkers. Amyloid burden and WMH were not correlated with one another. Age was associated with lower performance in all cognitive domains, while higher estimated verbal intelligence was associated with higher performance in all domains. Hypothesis-driven tests revealed that amyloid burden and WMH had distinct cognitive profiles, with amyloid burden having a specific influence on episodic memory and WMH primarily associated with executive function but having broad (but lesser) effects on the other domains. These findings suggest that even before clinical impairment, amyloid burden and WMH likely represent neuropathological cascades with distinct etiologies and dissociable influences on cognition.
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Affiliation(s)
- Trey Hedden
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
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Behrendt G, Baer K, Buffo A, Curtis MA, Faull RL, Rees MI, Götz M, Dimou L. Dynamic changes in myelin aberrations and oligodendrocyte generation in chronic amyloidosis in mice and men. Glia 2012; 61:273-86. [PMID: 23090919 DOI: 10.1002/glia.22432] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/11/2012] [Indexed: 11/08/2022]
Abstract
Myelin loss is frequently observed in human Alzheimer's disease (AD) and may constitute to AD-related cognitive decline. A potential source to repair myelin defects are the oligodendrocyte progenitor cells (OPCs) present in an adult brain. However, until now, little is known about the reaction of these cells toward amyloid plaque deposition neither in human AD patients nor in the appropriate mouse models. Therefore, we analyzed cells of the oligodendrocyte lineage in a mouse model with chronic plaque deposition (APPPS1 mice) and samples from human patients. In APPPS1 mice defects in myelin integrity and myelin amount were prevalent at 6 months of age but normalized to control levels in 9-month-old mice. Concomitantly, we observed an increase in the proliferation and differentiation of OPCs in the APPPS1 mice at this specific time window (6-8 months) implying that improvements in myelin aberrations may result from repair mechanisms mediated by OPCs. However, while we observed a higher number of cells of the oligodendrocyte lineage (Olig2+ cells) in APPPS1 mice, OLIG2+ cells were decreased in number in postmortem human AD cortex. Our data demonstrate that oligodendrocyte progenitors specifically react to amyloid plaque deposition in an AD-related mouse model as well as in human AD pathology, although with distinct outcomes. Strikingly, possible repair mechanisms from newly generated oligodendrocytes are evident in APPPS1 mice, whereas a similar reaction of oligodendrocyte progenitors seems to be strongly limited in final stages of human AD pathology.
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Affiliation(s)
- Gwendolyn Behrendt
- Department of Physiological Genomics, Institute of Physiology, Ludwig-Maximilians University, Munich, Germany
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