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Tsujita M, Melchior JT, Yokoyama S. Lipoprotein Particles in Cerebrospinal Fluid. Arterioscler Thromb Vasc Biol 2024; 44:1042-1052. [PMID: 38545782 DOI: 10.1161/atvbaha.123.318284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The brain is the most lipid-rich organ in the body, and the intricate interplay between lipid metabolism and pathologies associated with neurodegenerative disorders is being increasingly recognized. The brain is bathed in cerebrospinal fluid (CSF), which, like plasma, contains lipid-protein complexes called lipoproteins that are responsible for extracellular lipid transport. Multiple CSF lipoprotein populations exist, some of which are produced de novo in the central nervous system and others that appear to be generated from protein constituents that are produced in the periphery. These CSF lipoproteins are thought to play key roles in maintaining lipid homeostasis in the central nervous system, while little else is known due to their limited accessibility and their low abundance in CSF. Recent work has provided new insights into the compositional complexity of CSF lipoprotein families and their metabolism in cerebral circulation. The purpose of this review is to summarize our current state of knowledge on the composition, origin, and metabolism of CSF lipoproteins.
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Affiliation(s)
- Maki Tsujita
- Department of Biochemistry, Nagoya City University Graduate School of Medical Sciences, Japan (M.T.)
| | - John T Melchior
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington (J.T.M.)
- Department of Pathology and Laboratory Medicine, Center for Lipid and Arteriosclerosis Science, University of Cincinnati, OH (J.T.M.)
- Department of Neurology, Oregon Health and Science University, Portland (J.T.M.)
| | - Shinji Yokoyama
- Department of Food and Nutritional Sciences, Chubu University, Kasugai, Japan (S.Y.)
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2
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Krogsaeter EK, McKetney J, Marquez A, Cakir Z, Stevenson E, Jang GM, Rao A, Zhou A, Huang Y, Krogan NJ, Swaney DL. Lysosomal proteomics reveals mechanisms of neuronal apoE4associated lysosomal dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560519. [PMID: 37873080 PMCID: PMC10592882 DOI: 10.1101/2023.10.02.560519] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
ApoE4 is the primary risk factor for Alzheimer's Disease. While apoE is primarily expressed by astrocytes, AD pathology including endosomal abnormalities and mitochondrial dysfunction first occurs in neurons. Lysosomes are poised at the convergence point between these features. We find that apoE4-expressing cells exhibit lysosomal alkalinization, reduced lysosomal proteolysis, and impaired mitophagy. To identify driving factors for this lysosomal dysfunction, we performed quantitative lysosomal proteome profiling. This revealed that apoE4 expression results in lysosomal depletion of Lgals3bp and accumulation of Tmed5 in both Neuro-2a cells and postmitotic human neurons. Modulating the expression of both proteins affected lysosomal function, with Tmed5 knockdown rescuing lysosomal alkalinization in apoE4 cells, and Lgals3bp knockdown causing lysosomal alkalinization and reduced lysosomal density in apoE3 cells. Taken together, our work reveals that apoE4 exerts gain-of-toxicity by alkalinizing the lysosomal lumen, pinpointing lysosomal Tmed5 accumulation and Lgals3bp depletion as apoE4-associated drivers for this phenotype.
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Affiliation(s)
- Einar K. Krogsaeter
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- These authors contributed equally
| | - Justin McKetney
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
- These authors contributed equally
| | - Angelica Marquez
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Zeynep Cakir
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Erica Stevenson
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Gwendolyn M. Jang
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Antara Rao
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
- Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, USA
| | - Anton Zhou
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
| | - Yadong Huang
- Gladstone Institute of Neurological Disease, The J. David Gladstone Institutes, San Francisco, USA
- Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, USA
- Neuroscience Graduate Program, University of California, San Francisco, USA
- Gladstone Center for Translational Advancement, Gladstone Institutes, San Francisco, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, USA
- Departments of Neurology and Pathology, University of California, San Francisco, USA
| | - Nevan J. Krogan
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
| | - Danielle L. Swaney
- Gladstone Data Science and Biotechnology Institute, The J. David Gladstone Institutes, San Francisco, California, USA
- Quantitative Bioscience Institute, University of California, San Francisco, California, USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California, USA
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3
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Merrill NJ, Davidson WS, He Y, Díaz Ludovico I, Sarkar S, Berger MR, McDermott JE, Van Eldik LJ, Wilcock DM, Monroe ME, Kyle JE, Bruce KD, Heinecke JW, Vaisar T, Raber J, Quinn JF, Melchior JT. Human cerebrospinal fluid contains diverse lipoprotein subspecies enriched in proteins implicated in central nervous system health. SCIENCE ADVANCES 2023; 9:eadi5571. [PMID: 37647397 PMCID: PMC10468133 DOI: 10.1126/sciadv.adi5571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/25/2023] [Indexed: 09/01/2023]
Abstract
Lipoproteins in cerebrospinal fluid (CSF) of the central nervous system (CNS) resemble plasma high-density lipoproteins (HDLs), which are a compositionally and structurally diverse spectrum of nanoparticles with pleiotropic functionality. Whether CSF lipoproteins (CSF-Lps) exhibit similar heterogeneity is poorly understood because they are present at 100-fold lower concentrations than plasma HDL. To investigate the diversity of CSF-Lps, we developed a sensitive fluorescent technology to characterize lipoprotein subspecies in small volumes of human CSF. We identified 10 distinctly sized populations of CSF-Lps, most of which were larger than plasma HDL. Mass spectrometric analysis identified 303 proteins across the populations, over half of which have not been reported in plasma HDL. Computational analysis revealed that CSF-Lps are enriched in proteins important for wound healing, inflammation, immune response, and both neuron generation and development. Network analysis indicated that different subpopulations of CSF-Lps contain unique combinations of these proteins. Our study demonstrates that CSF-Lp subspecies likely exist that contain compositional signatures related to CNS health.
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Affiliation(s)
- Nathaniel J. Merrill
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - W. Sean Davidson
- Center for Lipid and Arteriosclerosis Science, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45237, USA
| | - Yi He
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Ivo Díaz Ludovico
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Snigdha Sarkar
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Madelyn R. Berger
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Jason E. McDermott
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA
| | - Linda J. Van Eldik
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40504, USA
| | - Donna M. Wilcock
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40504, USA
| | - Matthew E. Monroe
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Jennifer E. Kyle
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Kimberley D. Bruce
- Division of Endocrinology, Metabolism and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jay W. Heinecke
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Tomas Vaisar
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
| | - Jacob Raber
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
- Division of Neuroscience, Department of Behavioral Neuroscience and Radiation Medicine, ONPRC, Oregon Health and Science University, Portland, OR 97239, USA
| | - Joseph F. Quinn
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
- Department of Neurology and Parkinson’s Disease Research Education and Clinical Care Center (PADRECC), VA Portland Healthcare System, Portland OR 97239, USA
| | - John T. Melchior
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA
- Center for Lipid and Arteriosclerosis Science, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45237, USA
- Department of Neurology, Oregon Health and Science University, Portland, OR 97239, USA
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4
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The Molecular Effects of Environmental Enrichment on Alzheimer's Disease. Mol Neurobiol 2022; 59:7095-7118. [PMID: 36083518 PMCID: PMC9616781 DOI: 10.1007/s12035-022-03016-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/23/2022] [Indexed: 12/02/2022]
Abstract
Environmental enrichment (EE) is an environmental paradigm encompassing sensory, cognitive, and physical stimulation at a heightened level. Previous studies have reported the beneficial effects of EE in the brain, particularly in the hippocampus. EE improves cognitive function as well as ameliorates depressive and anxiety-like behaviors, making it a potentially effective neuroprotective strategy against neurodegenerative diseases such as Alzheimer's disease (AD). Here, we summarize the current evidence for EE as a neuroprotective strategy as well as the potential molecular pathways that can explain the effects of EE from a biochemical perspective using animal models. The effectiveness of EE in enhancing brain activity against neurodegeneration is explored with a view to differences present in early and late life EE exposure, with its potential application in human being discussed. We discuss EE as one of the non pharmacological approaches in preventing or delaying the onset of AD for future research.
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5
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Saavedra J, Nascimento M, Liz MA, Cardoso I. Key brain cell interactions and contributions to the pathogenesis of Alzheimer's disease. Front Cell Dev Biol 2022; 10:1036123. [PMID: 36523504 PMCID: PMC9745159 DOI: 10.3389/fcell.2022.1036123] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 11/14/2022] [Indexed: 06/22/2024] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide, with the two major hallmarks being the deposition of extracellular β-amyloid (Aβ) plaques and of intracellular neurofibrillary tangles (NFTs). Additionally, early pathological events such as cerebrovascular alterations, a compromised blood-brain barrier (BBB) integrity, neuroinflammation and synaptic dysfunction, culminate in neuron loss and cognitive deficits. AD symptoms reflect a loss of neuronal circuit integrity in the brain; however, neurons do not operate in isolation. An exclusively neurocentric approach is insufficient to understand this disease, and the contribution of other brain cells including astrocytes, microglia, and vascular cells must be integrated in the context. The delicate balance of interactions between these cells, required for healthy brain function, is disrupted during disease. To design successful therapies, it is critical to understand the complex brain cellular connections in AD and the temporal sequence of their disturbance. In this review, we discuss the interactions between different brain cells, from physiological conditions to their pathological reactions in AD, and how this basic knowledge can be crucial for developing new therapeutic strategies.
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Affiliation(s)
- Joana Saavedra
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Mariana Nascimento
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Márcia A. Liz
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Isabel Cardoso
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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6
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Lin Y, Dai X, Zhang J, Chen X. Metformin alleviates the depression-like behaviors of elderly apoE4 mice via improving glucose metabolism and mitochondrial biogenesis. Behav Brain Res 2022; 423:113772. [DOI: 10.1016/j.bbr.2022.113772] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/28/2021] [Accepted: 01/22/2022] [Indexed: 12/25/2022]
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7
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Grigoryan GA. Molecular-Cellular Mechanisms of Plastic Restructuring Produced by an Enriched Environment. Effects on Learning and Memory. NEUROCHEM J+ 2021. [DOI: 10.1134/s1819712421030041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Butt OH, Long JM, Henson RL, Herries E, Sutphen CL, Fagan AM, Cruchaga C, Ladenson JH, Holtzman DM, Morris JC, Ances BM, Schindler SE. Cognitively normal APOE ε4 carriers have specific elevation of CSF SNAP-25. Neurobiol Aging 2021; 102:64-72. [PMID: 33765432 PMCID: PMC8793109 DOI: 10.1016/j.neurobiolaging.2021.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 02/08/2021] [Accepted: 02/08/2021] [Indexed: 01/22/2023]
Abstract
Cerebrospinal fluid (CSF) synaptosomal-associated protein 25 (SNAP-25) and neurogranin (Ng) are recently described biomarkers for pre- and postsynaptic integrity known to be elevated in symptomatic Alzheimer disease (AD). Their relationship with Apolipoprotein E (APOE) ε4 carrier status, the major genetic risk factor for AD, remains unclear. In this study, CSF SNAP-25 and Ng were compared in cognitively normal APOE ε4 carriers and noncarriers (n = 274, mean age 65 ± 9.0 years, 39% APOE ε4 carriers, 58% female). CSF SNAP-25, not CSF Ng, was specifically elevated in APOE ε4 carriers versus noncarriers (5.95 ± 1.72 pg/mL, 4.44 ± 1.40 pg/mL, p < 0.0001), even after adjusting for age, sex, years of education, and amyloid status (p < 0.0001). CSF total tau (t-tau), phosphorylated-tau-181 (ptau181), and neurofilament light chain (NfL) also did not vary by APOE ε4 status. Our findings suggest APOE ε4 carriers have amyloid-related and amyloid-independent presynaptic disruption as reflected by elevated CSF SNAP-25 levels. In contrast, postsynaptic disruption as reflected by elevations in CSF neurogranin is related to amyloid status.
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Affiliation(s)
- Omar H Butt
- Department of Neurology, Washington University, Saint Louis, MO, USA
| | - Justin M Long
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - Rachel L Henson
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA
| | - Elizabeth Herries
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA
| | - Courtney L Sutphen
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA
| | - Anne M Fagan
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - Jack H Ladenson
- Department of Pathology and Immunology, Washington University, Saint Louis, MO, USA
| | - David M Holtzman
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - John C Morris
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA; Department of Pathology and Immunology, Washington University, Saint Louis, MO, USA
| | - Beau M Ances
- Department of Neurology, Washington University, Saint Louis, MO, USA; Department of Radiology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University, St. Louis, MO, USA
| | - Suzanne E Schindler
- Department of Neurology, Washington University, Saint Louis, MO, USA; Knight Alzheimer Disease Research Center, Washington University, St. Louis, MO, USA.
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9
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Novel Influences of Sex and APOE Genotype on Spinal Plasticity and Recovery of Function after Spinal Cord Injury. eNeuro 2021; 8:ENEURO.0464-20.2021. [PMID: 33536234 PMCID: PMC7986541 DOI: 10.1523/eneuro.0464-20.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/30/2020] [Accepted: 01/22/2021] [Indexed: 12/16/2022] Open
Abstract
Spinal cord injuries can abolish both motor and sensory function throughout the body. Spontaneous recovery after injury is limited and can vary substantially between individuals. Despite an abundance of therapeutic approaches that have shown promise in preclinical models, there is currently a lack of effective treatment strategies that have been translated to restore function after spinal cord injury (SCI) in the human population. We hypothesized that sex and genetic background of injured individuals could impact how they respond to treatment strategies, presenting a barrier to translating therapies that are not tailored to the individual. One gene of particular interest is APOE, which has been extensively studied in the brain because of its allele-specific influences on synaptic plasticity, metabolism, inflammation, and neurodegeneration. Despite its prominence as a therapeutic target in brain injury and disease, little is known about how it influences neural plasticity and repair processes in the spinal cord. Using humanized mice, we examined how the ε3 and ε4 alleles of APOE influence the efficacy of therapeutic intermittent hypoxia (IH) in inducing spinally-mediated plasticity after cervical SCI (cSCI). IH is sufficient to enhance plasticity and restore motor function after experimental SCI in genetically similar rodent populations, but its effect in human subjects is more variable (Golder and Mitchell, 2005; Hayes et al., 2014). Our results demonstrate that both sex and APOE genotype determine the extent of respiratory motor plasticity that is elicited by IH, highlighting the importance of considering these clinically relevant variables when translating therapeutic approaches for the SCI community.
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10
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Environmental enrichment prevents the late effect of acute stress-induced fear extinction deficit: the role of hippocampal AMPA-GluA1 phosphorylation. Transl Psychiatry 2021; 11:18. [PMID: 33414437 PMCID: PMC7791025 DOI: 10.1038/s41398-020-01140-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 11/22/2022] Open
Abstract
The persistence of anxiety and the deficit of fear memory extinction are both phenomena related to the symptoms of a trauma-related disorder, such as post-traumatic stress disorder (PTSD). Recently we have shown that single acute restraint stress (2 h) in rats induces a late anxiety-related behavior (observed ten days after stress), whereas, in the present work, we found that the same stress impaired fear extinction in animals conditioned ten days after stress. Fourteen days of environmental enrichment (EE) prevented the deleterious effect of stress on fear memory extinction. Additionally, we observed that EE prevented the stress-induced increase in AMPA receptor GluA1 subunit phosphorylation in the hippocampus, but not in the basolateral amygdala complex and the frontal cortex, indicating a potential mechanism by which it exerts its protective effect against the stress-induced behavioral outcome.
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11
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Sabbagh MN, Pope E, Cordes L, Shi J, DeCourt B. Therapeutic considerations for APOE and TOMM40 in Alzheimers disease: A tribute to Allen Roses MD. Expert Opin Investig Drugs 2021; 30:39-44. [PMID: 33455481 PMCID: PMC9262379 DOI: 10.1080/13543784.2021.1849138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/04/2020] [Indexed: 01/25/2023]
Abstract
Introduction: Four years ago this Autumn, pioneering neurologist Prof. Allen. D. Roses passed away. Hence, we have taken time to reflect on his work and legacy in Alzheimer's disease (AD) research. Prof. Roses rejected the widely accepted amyloid hypothesis, which identifies amyloid beta (Aβ) protein accumulation within the brain as the cause of AD. Instead, he proposed that the epsilon type 4 allele of apolipoprotein (APOE- Ɛ4) and translocase of outer mitochondrial membrane 40 homolog (TOMM40) were preeminent factors in the pathogenesis and progression of AD, particularly in late-onset AD (LOAD). This rejection of the amyloid hypothesis has generated new investigations into APOE and TOMM40 as risk factors for AD. Areas covered: We discuss the contributions of Prof. Roses to AD research, describe how APOE-Ɛ4 and TOMM40 have been posited to trigger neuropathological changes leading to AD, and explore paths to future clinical applications built on the foundations of his research. Expert opinion: The unconventional methodology of targeting APOE and TOMM40 offers great potential for the development of effective preventive and disease-modifying AD interventions. Future preclinical and clinical investigations will greatly benefit from the groundbreaking scientific discoveries of Prof. Roses.
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Affiliation(s)
| | - Evans Pope
- Cleveland Clinic, Lou Ruvo Center for Brain Health , Las Vegas, NV, USA
| | - Laura Cordes
- Cleveland Clinic, Lou Ruvo Center for Brain Health , Las Vegas, NV, USA
| | - Jiong Shi
- Cleveland Clinic, Lou Ruvo Center for Brain Health , Las Vegas, NV, USA
| | - Boris DeCourt
- Cleveland Clinic, Lou Ruvo Center for Brain Health , Las Vegas, NV, USA
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12
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Tan SZK, Du R, Perucho JAU, Chopra SS, Vardhanabhuti V, Lim LW. Dropout in Neural Networks Simulates the Paradoxical Effects of Deep Brain Stimulation on Memory. Front Aging Neurosci 2020; 12:273. [PMID: 33093830 PMCID: PMC7521073 DOI: 10.3389/fnagi.2020.00273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/10/2020] [Indexed: 12/02/2022] Open
Abstract
Neuromodulation techniques such as deep brain stimulation (DBS) are a promising treatment for memory-related disorders including anxiety, addiction, and dementia. However, the outcomes of such treatments appear to be somewhat paradoxical, in that these techniques can both disrupt and enhance memory even when applied to the same brain target. In this article, we hypothesize that disruption and enhancement of memory through neuromodulation can be explained by the dropout of engram nodes. We used a convolutional neural network (CNN) to classify handwritten digits and letters and applied dropout at different stages to simulate DBS effects on engrams. We showed that dropout applied during training improved the accuracy of prediction, whereas dropout applied during testing dramatically decreased the accuracy of prediction, which mimics enhancement and disruption of memory, respectively. We further showed that transfer learning of neural networks with dropout had increased the accuracy and rate of learning. Dropout during training provided a more robust “skeleton” network and, together with transfer learning, mimicked the effects of chronic DBS on memory. Overall, we showed that the dropout of engram nodes is a possible mechanism by which neuromodulation techniques such as DBS can both disrupt and enhance memory, providing a unique perspective on this paradox.
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Affiliation(s)
- Shawn Zheng Kai Tan
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Richard Du
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Jose Angelo Udal Perucho
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Shauhrat S Chopra
- School of Energy and Environment, City University of Hong Kong, Hong Kong, Hong Kong
| | - Varut Vardhanabhuti
- Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
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13
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MEF2C and HDAC5 regulate Egr1 and Arc genes to increase dendritic spine density and complexity in early enriched environment. Neuronal Signal 2020; 4:NS20190147. [PMID: 32714604 PMCID: PMC7378308 DOI: 10.1042/ns20190147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 01/16/2023] Open
Abstract
We investigated the effects of environmental enrichment during critical period of early postnatal life and how it interplays with the epigenome to affect experience-dependent visual cortical plasticity. Mice raised in an EE from birth to during CP have increased spine density and dendritic complexity in the visual cortex. EE upregulates synaptic plasticity genes, Arc and Egr1, and a transcription factor MEF2C. We also observed an increase in MEF2C binding to the promoters of Arc and Egr1. In addition, pups raised in EE show a reduction in HDAC5 and its binding to promoters of Mef2c, Arc and Egr1 genes. With an overexpression of Mef2c, neurite outgrowth increased in complexity. Our results suggest a possible underlying molecular mechanism of EE, acting through MEF2C and HDAC5, which drive Arc and Egr1. This could lead to the observed increased dendritic spine density and complexity induced by early EE.
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14
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Cardozo PL, de Lima IBQ, Maciel EMA, Silva NC, Dobransky T, Ribeiro FM. Synaptic Elimination in Neurological Disorders. Curr Neuropharmacol 2020; 17:1071-1095. [PMID: 31161981 PMCID: PMC7052824 DOI: 10.2174/1570159x17666190603170511] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/23/2019] [Accepted: 05/31/2019] [Indexed: 12/12/2022] Open
Abstract
Synapses are well known as the main structures responsible for transmitting information through the release and recognition of neurotransmitters by pre- and post-synaptic neurons. These structures are widely formed and eliminated throughout the whole lifespan via processes termed synaptogenesis and synaptic pruning, respectively. Whilst the first pro-cess is needed for ensuring proper connectivity between brain regions and also with the periphery, the second phenomenon is important for their refinement by eliminating weaker and unnecessary synapses and, at the same time, maintaining and fa-voring the stronger ones, thus ensuring proper synaptic transmission. It is well-known that synaptic elimination is modulated by neuronal activity. However, only recently the role of the classical complement cascade in promoting this phenomenon has been demonstrated. Specifically, microglial cells recognize activated complement component 3 (C3) bound to synapses tar-geted for elimination, triggering their engulfment. As this is a highly relevant process for adequate neuronal functioning, dis-ruptions or exacerbations in synaptic pruning could lead to severe circuitry alterations that could underlie neuropathological alterations typical of neurological and neuropsychiatric disorders. In this review, we focus on discussing the possible in-volvement of excessive synaptic elimination in Alzheimer’s disease, as it has already been reported dendritic spine loss in post-synaptic neurons, increased association of complement proteins with its synapses and, hence, augmented microglia-mediated pruning in animal models of this disorder. In addition, we briefly discuss how this phenomenon could be related to other neurological disorders, including multiple sclerosis and schizophrenia.
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Affiliation(s)
- Pablo L Cardozo
- Laboratório de Neurobioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Izabella B Q de Lima
- Laboratório de Neurobioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Esther M A Maciel
- Laboratório de Neurobioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nathália C Silva
- Laboratório de Neurobioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Fabíola M Ribeiro
- Laboratório de Neurobioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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15
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Koren-Iton A, Salomon-Zimri S, Smolar A, Shavit-Stein E, Dori A, Chapman J, Michaelson DM. Central and Peripheral Mechanisms in ApoE4-Driven Diabetic Pathology. Int J Mol Sci 2020; 21:E1289. [PMID: 32075060 PMCID: PMC7072920 DOI: 10.3390/ijms21041289] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 01/27/2020] [Accepted: 02/03/2020] [Indexed: 12/16/2022] Open
Abstract
Apolipoprotein E (APOE) ε4 gene allele and type 2 diabetes mellitus (T2DM) are prime risk factors for Alzheimer's disease (AD). Despite evidence linking T2DM and apoE4, the mechanism underlying their interaction is yet to be determined. In the present study, we employed a model of APOE-targeted replacement mice and high-fat diet (HFD)-induced insulin resistance to investigate diabetic mechanisms associated with apoE4 pathology and the extent to which they are driven by peripheral and central processes. Results obtained revealed an intriguing pattern, in which under basal conditions, apoE4 mice display impaired glucose and insulin tolerance and decreased insulin secretion, as well as cognitive and sensorimotor characteristics relative to apoE3 mice, while the HFD impairs apoE3 mice without significantly affecting apoE4 mice. Measurements of weight and fasting blood glucose levels increased in a time-dependent manner following the HFD, though no effect of genotype was observed. Interestingly, sciatic electrophysiological and skin intra-epidermal nerve fiber density (IENFD) peripheral measurements were not affected by the APOE genotype or HFD, suggesting that the observed sensorimotor and cognitive phenotypes are related to central nervous system processes. Indeed, measurements of hippocampal insulin receptor and glycogen synthase kinase-3β (GSK-3β) activation revealed a pattern similar to that obtained in the behavioral measurements while Akt activation presented a dominant effect of diet. HFD manipulation induced genotype-independent hyperlipidation of apoE, and reduced levels of brain apoE in apoE3 mice, rendering them similar to apoE4 mice, whose brain apoE levels were not affected by the diet. No such effect was observed in the peripheral plasma levels of apoE, suggesting that the pathological effects of apoE4 under the control diet and apoE3 under HFD conditions are related to the decreased levels of brain apoE. Taken together, our data suggests that diabetic mechanisms play an important role in mediating the pathological effects of apoE4 and that consequently, diabetic-related therapy may be useful in treating apoE4 pathology in AD.
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Affiliation(s)
- Amit Koren-Iton
- Department of Neurobiology, The Sagol School of Neuroscience, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 6997801, Israel; (A.K.-I.); (S.S.-Z.); (A.S.)
| | - Shiran Salomon-Zimri
- Department of Neurobiology, The Sagol School of Neuroscience, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 6997801, Israel; (A.K.-I.); (S.S.-Z.); (A.S.)
| | - Alex Smolar
- Department of Neurobiology, The Sagol School of Neuroscience, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 6997801, Israel; (A.K.-I.); (S.S.-Z.); (A.S.)
| | - Efrat Shavit-Stein
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 5261, Israel; (E.S.-S.); (A.D.); (J.C.)
- Department of Neurology and Neurosurgery, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Amir Dori
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 5261, Israel; (E.S.-S.); (A.D.); (J.C.)
| | - Joab Chapman
- Department of Neurology, The Chaim Sheba Medical Center, Ramat Gan 5261, Israel; (E.S.-S.); (A.D.); (J.C.)
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Robert and Martha Harden Chair in Mental and Neurological Diseases, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Daniel M. Michaelson
- Department of Neurobiology, The Sagol School of Neuroscience, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 6997801, Israel; (A.K.-I.); (S.S.-Z.); (A.S.)
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16
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Uchitel J, Alden E, Bhutta ZA, Goldhagen J, Narayan AP, Raman S, Spencer N, Wertlieb D, Wettach J, Woolfenden S, Mikati MA. The Rights of Children for Optimal Development and Nurturing Care. Pediatrics 2019; 144:peds.2019-0487. [PMID: 31771960 DOI: 10.1542/peds.2019-0487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/19/2019] [Indexed: 11/24/2022] Open
Abstract
Millions of children are subjected to abuse, neglect, and displacement, and millions more are at risk for not achieving their developmental potential. Although there is a global movement to change this, driven by children's rights, progress is slow and impeded by political considerations. The United Nations Convention on the Rights of the Child, a global comprehensive commitment to children's rights ratified by all countries in the world except the United States (because of concerns about impingement on sovereignty and parental authority), has a special General Comment on "Implementing Child Rights in Early Childhood." More recently, the World Health Organization and United Nations Children's Fund have launched the Nurturing Care Framework for Early Childhood Development (ECD), which calls for public policies that promote nurturing care interventions and addresses 5 interrelated components that are necessary for optimal ECD. This move is also complemented by the Human Capital Project of the World Bank, providing a focus on the need for investments in child health and nutrition and their long-term benefits. In this article, we outline children's rights under international law, the underlying scientific evidence supporting attention to ECD, and the philosophy of nurturing care that ensures that children's rights are respected, protected, and fulfilled. We also provide pediatricians anywhere with the policy and rights-based frameworks that are essential for them to care for and advocate for children and families to ensure optimal developmental, health, and socioemotional outcomes. These recommendations do not necessarily reflect American Academy of Pediatrics policy.
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Affiliation(s)
| | - Errol Alden
- International Pediatric Association and Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Zulfiqar A Bhutta
- Division of Women and Child Health, Aga Khan University, Karachi, Pakistan.,Centre for Global Child Health, The Hospital for Sick Children, Toronto, Canada
| | - Jeffrey Goldhagen
- Division of Community and Societal Pediatrics, Department of Pediatrics, College of Medicine, University of Florida, Jacksonville, Florida
| | | | - Shanti Raman
- International Pediatrics Association Standing Committee, International Society of Social Pediatrics and Child Health, Geneva, Switzerland.,Division of Community Pediatric, South Western Sydney Local Health District, Sydney, New South Wales, Australia
| | - Nick Spencer
- Division of Mental Health and Wellbeing, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Donald Wertlieb
- Eliot-Pearson Department of Child Study and Human Development, School of Arts and Sciences, Tufts University, Medford, Massachusetts
| | - Jane Wettach
- Duke Children's Law Clinic, School of Law, Duke University, Durham, North Carolina; and
| | - Sue Woolfenden
- Discipline of Paediatrics, School of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Mohamad A Mikati
- Division of Pediatric Neurology and .,Early Childhood Development Standing Advisory Group, International Pediatrics Association, St Louis, Missouri
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17
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Har-Paz I, Roisman N, Michaelson DM, Moran A. Extra-Hippocampal Learning Deficits in Young Apolipoprotein E4 Mice and Their Synaptic Underpinning. J Alzheimers Dis 2019; 72:71-82. [PMID: 31561365 DOI: 10.3233/jad-190564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The E4 allele of apolipoprotein (apoE4) is the primary genetic risk factor for late onset Alzheimer's disease (AD), yet the exact manner in which apoE4 leads to the development of AD is undetermined. Human and animal studies report that apoE4-related memory deficits appear earlier than the AD clinical manifestation, thus suggesting the existence of early, pre-pathological, apoE4 impairments that may later lead to AD onset. While current research regards the hippocampus as the initial and primary effected locus by apoE4, we presently investigate the possibility that apoE4 innately impairs any brain area that requires synaptic plasticity. To test this hypothesis, we trained young (3-4-month-old) target-replacement apoE3 and apoE4 mice in conditioned taste aversion (CTA) acquisition and extinction learnings- hippocampus-independent learnings that are easily performed at a young age. Synaptic vesicular markers analysis was conducted in the gustatory cortex (GC), basolateral amygdala (BLA), medial prefrontal cortex (mPFC), and hippocampal CA3 to reveal underlying apoE4-related impairments. We have found that young apoE4 mice are severely impaired in CTA acquisition and extinction learning. CTA acquisition impairments were correlated with reduced vGat and vGlut levels in the BLA and GC, but not in the CA3. CTA extinction was correlated with lower synaptophysin and vGlut levels in the mPFC, a central region in CTA extinction. Our results support apoE4-related early-life plasticity impairments that precede the AD clinical manifestations and affect any brain area that depends on extensive plasticity; early impairments that may promote the development of AD pathologies later in life.
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Affiliation(s)
- Ilona Har-Paz
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Nicole Roisman
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Daniel M Michaelson
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Anan Moran
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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18
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Ben-Moshe H, Luz I, Liraz O, Boehm-Cagan A, Salomon-Zimri S, Michaelson D. ApoE4 Exacerbates Hippocampal Pathology Following Acute Brain Penetration Injury in Female Mice. J Mol Neurosci 2019; 70:32-44. [DOI: 10.1007/s12031-019-01397-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 08/14/2019] [Indexed: 10/26/2022]
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19
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Dunn AR, O'Connell KMS, Kaczorowski CC. Gene-by-environment interactions in Alzheimer's disease and Parkinson's disease. Neurosci Biobehav Rev 2019; 103:73-80. [PMID: 31207254 PMCID: PMC6700747 DOI: 10.1016/j.neubiorev.2019.06.018] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 06/06/2019] [Accepted: 06/12/2019] [Indexed: 12/12/2022]
Abstract
Diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) arise from complex interactions of genetic and environmental factors, with genetic variants regulating individual responses to environmental exposures (i.e. gene-by-environment interactions). Identifying gene-by-environment interactions will be critical to fully understanding disease mechanisms and developing personalized therapeutics, though these interactions are still poorly understood and largely under-studied. Candidate gene approaches have shown that known disease risk variants often regulate response to environmental factors. However, recent improvements in exposome- and genome-wide association and interaction studies in humans and mice are enabling discovery of novel genetic variants and pathways that predict response to a variety of environmental factors. Here, we highlight recent approaches and ongoing developments in human and rodent studies to identify genetic modulators of environmental factors using AD and PD as exemplars. Identifying gene-by-environment interactions in disease will be critical to developing personalized intervention strategies and will pave the way for precision medicine.
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Affiliation(s)
- Amy R Dunn
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA.
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20
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Targeting Apolipoprotein E for Alzheimer's Disease: An Industry Perspective. Int J Mol Sci 2019; 20:ijms20092161. [PMID: 31052389 PMCID: PMC6539182 DOI: 10.3390/ijms20092161] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/27/2019] [Accepted: 04/28/2019] [Indexed: 02/08/2023] Open
Abstract
Apolipoprotein E (apoE), a key lipid transport protein in the brain, is predominantly produced by astrocytes. Astrocytes are the most numerous cell type in the brain and are the main support network for neurons. They play a critical role in the synthesis and delivery of cholesterol in the brain. Humans have three common apoE isoforms, apoE2, apoE3 and apoE4, that show a strong genotype effect on the risk and age of onset for sporadic and late onset forms of Alzheimer’s disease (AD). Carriers of an ε4 allele have an increased risk of developing AD, while those with an ε2 allele are protected. Investigations into the contribution of apoE to the development of AD has yielded conflicting results and there is still much speculation about the role of this protein in disease. Here, we review the opposing hypotheses currently described in the literature and the approaches that have been considered for targeting apoE as a novel therapeutic strategy for AD. Additionally, we provide our perspective on the rationale for targeting apoE and the challenges that arise with respect to “drug-ability” of this target.
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21
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Kentner AC, Cryan JF, Brummelte S. Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity. Dev Psychobiol 2019; 61:350-375. [PMID: 30311210 PMCID: PMC6447439 DOI: 10.1002/dev.21775] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/22/2018] [Accepted: 07/10/2018] [Indexed: 12/20/2022]
Abstract
Despite the increasing attention to early life adversity and its long-term consequences on health, behavior, and the etiology of neurodevelopmental disorders, our understanding of the adaptations and interventions that promote resiliency and rescue against such insults are underexplored. Specifically, investigations of the perinatal period often focus on negative events/outcomes. In contrast, positive experiences (i.e. enrichment/parental care//healthy nutrition) favorably influence development of the nervous and endocrine systems. Moreover, some stressors result in adaptations and demonstrations of later-life resiliency. This review explores the underlying mechanisms of neuroplasticity that follow some of these early life experiences and translates them into ideas for interventions in pediatric settings. The emerging role of the gut microbiome in mediating stress susceptibility is also discussed. Since many negative outcomes of early experiences are known, it is time to identify mechanisms and mediators that promote resiliency against them. These range from enrichment, quality parental care, dietary interventions and those that target the gut microbiota.
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Affiliation(s)
- Amanda C. Kentner
- School of Arts & Sciences, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Ave, Boston, MA 02115,
| | - John F. Cryan
- Dept. Anatomy & Neuroscience & APC Microbiome Institute, University College Cork, College Rd., Cork, Ireland,
| | - Susanne Brummelte
- Department of Psychology, Wayne State University, 5057 Woodward Ave, Detroit, MI 48202,
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22
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Zhang J, Lin Y, Dai X, Fang W, Wu X, Chen X. Metformin treatment improves the spatial memory of aged mice in an APOE genotype-dependent manner. FASEB J 2019; 33:7748-7757. [PMID: 30894020 DOI: 10.1096/fj.201802718r] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aging and apolipoprotein E4 (ApoE4) can increase the risk of cognitive impairment and neurodegenerative disorders, including Alzheimer's disease (AD), and patients with type 2 diabetes mellitus are highly susceptible to cognitive dysfunction. Recent research has indicated that metformin, a prescribed drug for type 2 diabetes, may affect cognitive function; however, findings regarding its efficacy are largely controversial. The current study reported that a 5-mo metformin administration (300 mg/kg/d) starting at 13 mo old improved the spatial memory of ApoE3-target replacement (TR) mice, not ApoE4-TR mice. It found that in aged ApoE3-TR mice, metformin treatment, at a molecular level, inhibited AMPK activity, increased insulin signaling, and activated mammalian target of rapamycin signaling, resulting in an enhanced expression of postsynaptic proteins; but the response of the neuronal AMPK activity and insulin signaling to metformin was blunt in aged ApoE4-TR mice. Meanwhile, metformin treatment also increased the phosphorylation of tau in both ApoE3-TR and ApoE4-TR mice, implying that metformin may have side effects in human. These findings suggest that metformin can improve the cognitive performance of aged mice in an APOE genotype-dependent manner, which provides empirical insights into the clinical value of metformin for ApoE4- and age-related AD prevention and treatment.-Zhang, J., Lin, Y., Dai, X., Fang, W., Wu, X., Chen, X. Metformin treatment improves the spatial memory of aged mice in an APOE genotype-dependent manner.
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Affiliation(s)
- Jing Zhang
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Yingbin Lin
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xiaoman Dai
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Wenting Fang
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xilin Wu
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Xiaochun Chen
- Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China.,Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
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23
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Simonovitch S, Schmukler E, Masliah E, Pinkas-Kramarski R, Michaelson DM. The Effects of APOE4 on Mitochondrial Dynamics and Proteins in vivo. J Alzheimers Dis 2019; 70:861-875. [PMID: 31306119 PMCID: PMC7478177 DOI: 10.3233/jad-190074] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study examined the effects of apolipoprotein E4 (APOE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), on proteins involved in mitochondrial dynamics and autophagy, in the hippocampus of targeted replacement mice. Immunohistochemical measurements revealed that the levels of the mitochondrial fusion-mediating protein, MFN1, were higher, whereas those of corresponding fission-regulating protein, DRP-1, were lower in the hippocampus of ApoE4 mice than in the corresponding ApoE3 mice, indicating that APOE4 is associated with increased mitochondrial fusion and decreased fission. A similar ApoE4-driven decrease in DRP-1 was also observed in AD brains. The levels of the mitochondrial proteins COX1 and Tom40, were higher in the ApoE4 mice, which is consistent with the increased fusion. Measurements of the levels of cleaved PINK1 and parkin, which mark and target mitochondria for mitophagic degradation, revealed lower levels of cleaved PINK1, suggesting reduced mitochondrial membrane potential, and higher levels of parkin in the hippocampus of ApoE4 compared with the ApoE3 mice, indicating altered mitophagy. The levels of the ubiquitin-binding scaffold protein, p62/SQSTM1, which directs selected cargo to the autophagosomes, were also higher in the ApoE4 mice. These findings suggest that APOE4 is associated with enhanced mitochondrial fusion and decreased fission. Additionally, the results indicate that mitophagy/autophagy is reduced in ApoE4 mice, resulting in higher levels of proteins such as parkin and p62, which are normally degraded during this process. Taken together, these results suggest a novel mechanism that may underlie the pathological effects of APOE4 and indicate that use of APOE4 genotyping could pave the way for identification of novel APOE4-related therapeutic targets.
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Affiliation(s)
- Shira Simonovitch
- Department of Neurobiology, Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Eran Schmukler
- Department of Neurobiology, Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Eliezer Masliah
- Molecular Neuropathology Section, Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
- Department Neurosciences, School of Medicine, University of California, La Jolla, San Diego, CA, USA
- Department of Pathology, School of Medicine, University of California, La Jolla, San Diego, CA, USA
| | - Ronit Pinkas-Kramarski
- Department of Neurobiology, Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Daniel M Michaelson
- Department of Neurobiology, Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
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24
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Abstract
Synapse is the basic structural and functional component for neural communication in the brain. The presynaptic terminal is the structural and functionally essential area that initiates communication and maintains the continuous functional neural information flow. It contains synaptic vesicles (SV) filled with neurotransmitters, an active zone for release, and numerous proteins for SV fusion and retrieval. The structural and functional synaptic plasticity is a representative characteristic; however, it is highly vulnerable to various pathological conditions. In fact, synaptic alteration is thought to be central to neural disease processes. In particular, the alteration of the structural and functional phenotype of the presynaptic terminal is a highly significant evidence for neural diseases. In this review, we specifically describe structural and functional alteration of nerve terminals in several neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD).
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Affiliation(s)
- Jae Ryul Bae
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Korea
| | - Sung Hyun Kim
- Department of Physiology, School of Medicine, Kyung Hee University, Seoul 02447, Korea
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25
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Forero DA, López-León S, González-Giraldo Y, Dries DR, Pereira-Morales AJ, Jiménez KM, Franco-Restrepo JE. APOE gene and neuropsychiatric disorders and endophenotypes: A comprehensive review. Am J Med Genet B Neuropsychiatr Genet 2018; 177:126-142. [PMID: 27943569 DOI: 10.1002/ajmg.b.32516] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/07/2016] [Indexed: 12/14/2022]
Abstract
The Apolipoprotein E (APOE) gene is one of the main candidates in neuropsychiatric genetics, with hundreds of studies carried out in order to explore the possible role of polymorphisms in the APOE gene in a large number of neurological diseases, psychiatric disorders, and related endophenotypes. In the current article, we provide a comprehensive review of the structural and functional aspects of the APOE gene and its relationship with brain disorders. Evidence from genome-wide association studies and meta-analyses shows that the APOE gene has been significantly associated with several neurodegenerative disorders. Cellular and animal models show growing evidence of the key role of APOE in mechanisms of brain plasticity and behavior. Future analyses of the APOE gene might find a possible role in other neurological diseases and psychiatric disorders and related endophenotypes. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Diego A Forero
- Laboratory of Neuropsychiatric Genetics, Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia.,PhD Program in Health Sciences, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
| | | | - Yeimy González-Giraldo
- Departamento de Nutrición y Bioquímica, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Daniel R Dries
- Chemistry Department, Juniata College, Huntingdon, Pennsylvania
| | - Angela J Pereira-Morales
- Laboratory of Neuropsychiatric Genetics, Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
| | - Karen M Jiménez
- Laboratory of Neuropsychiatric Genetics, Biomedical Sciences Research Group, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
| | - Juan E Franco-Restrepo
- PhD Program in Health Sciences, School of Medicine, Universidad Antonio Nariño, Bogotá, Colombia
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26
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Salomon-Zimri S, Glat MJ, Barhum Y, Luz I, Boehm-Cagan A, Liraz O, Ben-Zur T, Offen D, Michaelson DM. Reversal of ApoE4-Driven Brain Pathology by Vascular Endothelial Growth Factor Treatment. J Alzheimers Dis 2018; 53:1443-58. [PMID: 27372644 DOI: 10.3233/jad-160182] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Apolipoprotein E4 (ApoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), is associated with increased neurodegeneration and vascular impairments. Vascular endothelial growth factor (VEGF), originally described as a key angiogenic factor, has recently been shown to play a crucial role in the nervous system. The objective of this research is to examine the role of VEGF in mediating the apoE4-driven pathologies. We show that hippocampal VEGF levels are lower in apoE4 targeted replacement mice compared to the corresponding apoE3 mice. This effect was accompanied by a specific decrease in both VEGF receptor-2 and HIF1-α. We next set to examine whether upregulation of VEGF can reverse apoE4-driven pathologies, namely the accumulation of hyperphosphorylated tau (AT8) and Aβ42, and reduced levels of the pre-synaptic marker, VGluT1, and of the ApoE receptor, ApoER2. This was first performed utilizing intra-hippocampal injection of VEGF-expressing-lentivirus (LV-VEGF). This revealed that LV-VEGF treatment reversed the apoE4-driven cognitive deficits and synaptic pathologies. The levels of Aβ42 and AT8, however, were increased in apoE3 mice, masking any potential effects of this treatment on the apoE4 mice. Follow-up experiments utilizing VEGF-expressing adeno-associated-virus (AAV-VEGF), which expresses VEGF specifically under the GFAP astrocytic promoter, prevented this effects on apoE3 mice, and reversed the apoE4-related increase in Aβ42 and AT8. Taken together, these results suggest that apoE4-driven pathologies are mediated by a VEGF-dependent pathway, resulting in cognitive impairments and brain pathology. These animal model findings suggest that the VEGF system is a promising target for the treatment of apoE4 carriers in AD.
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Affiliation(s)
- Shiran Salomon-Zimri
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Micaela Johanna Glat
- Sackler School of Medicine, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yael Barhum
- Sackler School of Medicine, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ishai Luz
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Anat Boehm-Cagan
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ori Liraz
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tali Ben-Zur
- Sackler School of Medicine, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Daniel Offen
- Sackler School of Medicine, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Daniel M Michaelson
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Boehm-Cagan A, Bar R, Liraz O, Bielicki JK, Johansson JO, Michaelson DM. ABCA1 Agonist Reverses the ApoE4-Driven Cognitive and Brain Pathologies. J Alzheimers Dis 2018; 54:1219-1233. [PMID: 27567858 DOI: 10.3233/jad-160467] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The allele ɛ4 of apolipoprotein E (apoE4) is the most prevalent genetic risk factor for Alzheimer's disease (AD) and is therefore a promising therapeutic target. Human and animal model studies suggest that apoE4 is hypolipidated; accordingly, we have previously shown that the retinoid X receptor (RXR) agonist bexarotene upregulates ABCA1, the main apoE-lipidating protein, resulting in increased lipidation of apoE4, and the subsequent reversal of the pathological effects of apoE4, namely: accumulation of Aβ42 and hyperphosphorylated tau, as well as reduction in the levels of synaptic markers and cognitive deficits. Since the RXR system has numerous other targets, it is important to devise the means of activating ABCA1 selectively. We presently utilized CS-6253, a peptide shown to directly activate ABCA1 in vitro, and examined the extent to which it can affect the degree of lipidation of apoE4 in vivo and counteract the associated brain and behavioral pathologies. This revealed that treatment of young apoE4-targeted replacement mice with CS-6253 increases the lipidation of apoE4. This was associated with a reversal of the apoE4-driven Aβ42 accumulation and tau hyperphosphorylation in hippocampal neurons, as well as of the synaptic impairments and cognitive deficits. These findings suggest that the pathological effects of apoE4 in vivo are associated with decreased activation of ABCA1 and impaired lipidation of apoE4 and that the downstream brain-related pathology and cognitive deficits can be counteracted by treatment with the ABCA1 agonist CS-6253. These findings have important clinical ramifications and put forward ABCA1 as a promising target for apoE4-related treatment of AD.
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Affiliation(s)
- Anat Boehm-Cagan
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Roni Bar
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ori Liraz
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - John K Bielicki
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA
| | | | - Daniel M Michaelson
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Environmental Factors Promoting Neural Plasticity: Insights from Animal and Human Studies. Neural Plast 2017; 2017:7219461. [PMID: 28740740 PMCID: PMC5504954 DOI: 10.1155/2017/7219461] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/17/2017] [Accepted: 05/10/2017] [Indexed: 11/17/2022] Open
Abstract
We do not all grow older in the same way. Some individuals have a cognitive decline earlier and faster than others who are older in years but cerebrally younger. This is particularly easy to verify in people who have maintained regular physical activity and healthy and cognitively stimulating lifestyle and even in the clinical field. There are patients with advanced neurodegeneration, such as Alzheimer's disease (AD), that, despite this, have mild cognitive impairment. What determines this interindividual difference? Certainly, it cannot be the result of only genetic factors. We are made in a certain manner and what we do acts on our brain. In fact, our genetic basis can be modulated, modified, and changed by our experiences such as education and life events; daily, by sleep schedules and habits; or also by dietary elements. And this can be seen as true even if our experiences are indirectly driven by our genetic basis. In this paper, we will review some current scientific research on how our experiences are able to modulate the structural organization of the brain and how a healthy lifestyle (regular physical activity, correct sleep hygiene, and healthy diet) appears to positively affect cognitive reserve.
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Boehm-Cagan A, Bar R, Harats D, Shaish A, Levkovitz H, Bielicki JK, Johansson JO, Michaelson DM. Differential Effects of apoE4 and Activation of ABCA1 on Brain and Plasma Lipoproteins. PLoS One 2016; 11:e0166195. [PMID: 27824936 PMCID: PMC5100931 DOI: 10.1371/journal.pone.0166195] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/24/2016] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E4 (apoE4), the leading genetic risk factor for Alzheimer's disease (AD), is less lipidated compared to the most common and AD-benign allele, apoE3. We have recently shown that i.p. injections of the ATP-binding cassette A1 (ABCA1) agonist peptide CS-6253 to apoE mice reverse the hypolipidation of apoE4 and the associated brain pathology and behavioral deficits. While in the brain apoE is the main cholesterol transporter, in the periphery apoE and apoA-I both serve as the major cholesterol transporters. We presently investigated the extent to which apoE genotype and CS-6253 treatment to apoE3 and apoE4-targeted replacement mice affects the plasma levels and lipid particle distribution of apoE, and those of plasma and brain apoA-I and apoJ. This revealed that plasma levels of apoE4 were lower and eluted faster following FPLC than plasma apoE3. Treatment with CS-6253 increased the levels of plasma apoE4 and rendered the elution profile of apoE4 similar to that of apoE3. Similarly, the levels of plasma apoA-I were lower in the apoE4 mice compared to apoE3 mice, and this effect was partially reversed by CS-6253. Conversely, the levels of apoA-I in the brain which were higher in the apoE4 mice, were unaffected by CS-6253. The plasma levels of apoJ were higher in apoE4 mice than apoE3 mice and this effect was abolished by CS-6253. Similar but less pronounced effects were obtained in the brain. In conclusion, these results suggest that apoE4 affects the levels of apoA-I and apoJ and that the anti-apoE4 beneficial effects of CS-6253 may be related to both central and peripheral mechanisms.
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Affiliation(s)
- Anat Boehm-Cagan
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roni Bar
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Dror Harats
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - Aviv Shaish
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - Hana Levkovitz
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - John K. Bielicki
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California, 94720, United States of America
| | - Jan O. Johansson
- Artery Therapeutics, Inc. San Ramon, California, United States of America
| | - Daniel M. Michaelson
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- * E-mail:
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Iacono D, Zandi P, Gross M, Markesbery WR, Pletnikova O, Rudow G, Troncoso JC. APOε2 and education in cognitively normal older subjects with high levels of AD pathology at autopsy: findings from the Nun Study. Oncotarget 2016; 6:14082-91. [PMID: 26101858 PMCID: PMC4546453 DOI: 10.18632/oncotarget.4118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/30/2015] [Indexed: 11/25/2022] Open
Abstract
Asymptomatic Alzheimer's disease (ASYMAD) subjects are individuals characterized by preserved cognition before death despite substantial AD pathology at autopsy. ASYMAD subjects show comparable levels of AD pathology, i.e. β-amyloid neuritic plaques (Aβ-NP) and tau-neurofibrillary tangles (NFT), to those observed in mild cognitive impairment (MCI) and some definite AD cases. Previous clinicopathologic studies on ASYMAD subjects have shown specific phenomena of hypertrophy in the cell bodies, nuclei, and nucleoli of hippocampal pyramidal neurons and other cerebral areas. Since it is well established that the allele APOε4 is a major genetic risk factor for AD, we examined whether specific alleles of APOE could be associated with the different clinical outcomes between ASYMAD and MCI subjects despite equivalent AD pathology. A total of 523 brains from the Nun Study were screened for this investigation. The results showed higher APOε2 frequency (p < 0.001) in ASYMAD (19.2%) vs. MCI (0%) and vs. AD (4.7%). Furthermore, higher education in ASYMAD vs. MCI and AD (p < 0.05) was found. These novel autopsy-verified findings support the hypothesis of the beneficial effect of APOε2 and education, both which seem to act as contributing factors in delaying or forestalling the clinical manifestations of AD despite consistent levels of AD pathology.
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Affiliation(s)
- Diego Iacono
- Neuropathology Division, Department of Pathology, Johns Hopkins University, Baltimore, MD, USA.,Neuropathology Research, Biomedical Research Institute of New Jersey, Cedar Knolls, NJ, USA.,Atlantic Neuroscience Institute, Overlook Medical Center, Summit, NJ, USA.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Peter Zandi
- Department of Mental Health, Johns Hopkins University, Baltimore, MD, USA
| | - Myron Gross
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
| | - William R Markesbery
- Department of Pathology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.,Department of Neurology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.,Alzheimer's Disease Center, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Olga Pletnikova
- Neuropathology Division, Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
| | - Gay Rudow
- Neuropathology Division, Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
| | - Juan C Troncoso
- Neuropathology Division, Department of Pathology, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
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Janssen CIF, Jansen D, Mutsaers MPC, Dederen PJWC, Geenen B, Mulder MT, Kiliaan AJ. The Effect of a High-Fat Diet on Brain Plasticity, Inflammation and Cognition in Female ApoE4-Knockin and ApoE-Knockout Mice. PLoS One 2016; 11:e0155307. [PMID: 27171180 PMCID: PMC4865084 DOI: 10.1371/journal.pone.0155307] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 04/27/2016] [Indexed: 11/24/2022] Open
Abstract
Apolipoprotein E4 (ApoE4), one of three common isoforms of ApoE, is a major risk factor for late-onset Alzheimer disease (AD). ApoE-deficient mice, as well as mice expressing human ApoE4, display impaired learning and memory functions and signs of neurodegeneration. Moreover, ApoE protects against high-fat (HF) diet induced neurodegeneration by its role in the maintenance of the integrity of the blood-brain barrier. The influence of a HF diet on the progression of AD-like cognitive and neuropathological changes was assessed in wild-type (WT), human ApoE4 and ApoE-knockout (ApoE-/-) mice to evaluate the modulatory role of ApoE in this process. From 12 months of age, female WT, ApoE4, and ApoE-/- mice were fed either a standard or a HF diet (19% butter, 0.5% cholate, 1.25% cholesterol) throughout life. At 15 months of age mice performed the Morris water maze, evaluating spatial learning and memory. ApoE-/- showed increased spatial learning compared to WT mice (p = 0.009). HF diet improved spatial learning in WT mice (p = 0.045), but did not affect ApoE4 and ApoE-/- mice. Immunohistochemical analyses of the hippocampus demonstrated increased neuroinflammation (CD68) in the cornu ammonis 1 (CA1) region in ApoE4 (p = 0.001) and in ApoE-/- (p = 0.032) mice on standard diet. HF diet tended to increase CD68 in the CA1 in WT mice (p = 0.052), while it decreased in ApoE4 (p = 0.009), but ApoE-/- remained unaffected. A trend towards increased neurogenesis (DCX) was found in both ApoE4 (p = 0.052) and ApoE-/- mice (p = 0.068). In conclusion, these data suggest that HF intake induces different effects in WT mice compared to ApoE4 and ApoE-/- with respect to markers for cognition and neurodegeneration. We propose that HF intake inhibits the compensatory mechanisms of neuroinflammation and neurogenesis in aged female ApoE4 and ApoE-/- mice.
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Affiliation(s)
- Carola I. F. Janssen
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Diane Jansen
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Martina P. C. Mutsaers
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Pieter J. W. C. Dederen
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Bram Geenen
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Monique T. Mulder
- Department of Internal Medicine, Laboratory of Vascular Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Amanda J. Kiliaan
- Department of Anatomy, Donders Institute for Brain, Cognition, and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
- * E-mail:
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Maharshak I, Salomon-Zimri S, Antes R, Liraz O, Nisgav Y, Livnat T, Weinberger D, Colton CA, Solomon AS, Michaelson DM. The effects of the apoE4 genotype on the developing mouse retina. Exp Eye Res 2016; 145:17-25. [DOI: 10.1016/j.exer.2015.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 10/27/2015] [Accepted: 11/03/2015] [Indexed: 01/03/2023]
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Reverte I, Peris-Sampedro F, Basaure P, Campa L, Suñol C, Moreno M, Domingo JL, Colomina MT. Attentional performance, impulsivity, and related neurotransmitter systems in apoE2, apoE3, and apoE4 female transgenic mice. Psychopharmacology (Berl) 2016; 233:295-308. [PMID: 26497539 DOI: 10.1007/s00213-015-4113-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/06/2015] [Indexed: 12/27/2022]
Abstract
RATIONALE The apolipoprotein E (apoE) genotype influences cognitive performance in humans depending on age and sex. While the detrimental role of the apoE4 isoform on spatial learning and memory has been well-established in humans and rodents, less is known on its impact on the executive functions. OBJECTIVES We aimed to evaluate the effect of apoE isoforms (apoE2, apoE3, apoE4) on visuospatial attention and inhibitory control performance in female transgenic mice, and to determine the neurochemical and neuropharmacological basis of this potential relationship. METHODS Female mice carrying apoE2, apoE3, and apoE4 were trained in the five-choice serial reaction time task (5-CSRTT). Upon a stable performance, we manipulated the inter-trial interval and the stimulus duration to elicit impulsive responding and engage attention respectively. We further performed a pharmacological challenge by administering cholinergic and GABAergic agents. Finally, we analyzed the levels of brain amino acids and monoamines by using reversed phase high-performance liquid chromatography (HPLC). RESULTS ApoE4 mice showed a deficient inhibitory control as revealed by increased perseveration and premature responding. When attention was challenged, apoE4 mice also showed a higher drop in accuracy. The adverse effect of scopolamine on the task was attenuated in apoE4 mice compared to apoE2 and apoE3. Furthermore, apoE4 mice showed less dopamine in the frontal cortex than apoE2 mice. CONCLUSIONS We confirmed that the apoE genotype influences attention and inhibitory control in female transgenic mice. The influence of apoE isoforms in the brain neuromodulatory system may explain the cognitive and behavioral differences attributable to the genotype.
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Environmental enrichment as a method to improve cognitive function. What can we learn from animal models? Neuroimage 2015; 131:42-7. [PMID: 26656208 DOI: 10.1016/j.neuroimage.2015.11.039] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/12/2015] [Accepted: 11/15/2015] [Indexed: 01/21/2023] Open
Abstract
There is substantial evidence that physical and cognitive exercise can enhance memory function in rodents as well as in humans. In addition various behaviors associated with physical activity have been associated with an increased cognitive reserve and a lower risk to develop age-associated memory decline and age-associated neurodegenerative diseases such as Alzheimer's disease. To better understand the molecular mechanisms that increase brain plasticity in response to exercise will therefore help to develop effective therapeutic strategies to treat memory decline. Here we review the currently available data with a specific focus on neurodegenerative diseases.
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Salomon-Zimri S, Liraz O, Michaelson DM. Behavioral testing affects the phenotypic expression of APOE ε3 and APOE ε4 in targeted replacement mice and reduces the differences between them. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2015; 1:127-35. [PMID: 27239500 PMCID: PMC4876887 DOI: 10.1016/j.dadm.2014.11.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Apolipoprotein E4 (APOE ε4) is the most prevalent genetic risk factor for Alzheimer's disease (AD). Targeted replacement mice that express either APOE ε4 or its AD benign isoform, APOE ε3, are used extensively in behavioral, biochemical, and physiological studies directed at assessing the phenotypic effects of APOE ε4 and at unraveling the mechanisms underlying them. Such experiments often involve pursuing biochemical and behavioral measurements on the same cohort of mice. In view of the possible cross-talk interactions between brain parameters and cognitive performance, we presently investigated the extent to which the phenotypic expression of APOE ε4 and APOE ε4 in targeted replacement mice is affected by behavioral testing. This was performed using young, naïve APOE ε4 and APOE ε3 mice in which the levels of distinct brain parameters are affected by the APOE genotype (e.g., elevated levels of amyloid beta [Aβ] and hyperphosphorylated tau and reduced levels of vesicular glutamate transporter (VGLUT) in hippocampal neurons of APOE ε4 mice). These mice were exposed to a fear-conditioning paradigm, and the resulting effects on the brain parameters were examined. The results obtained revealed that the levels of Aβ, hyperphosphorylated tau, VGluT, and doublecortin of the APOE ε4 and APOE ε3 mice were markedly affected following the exposure of APOE ε4 and APOE ε3 mice to the fear-conditioning paradigm such that the isoform-specific effects of APOE ε4 on these parameters were greatly diminished. The finding that behavioral testing affects the APOE ε3 and APOE ε4 phenotypes and masks the differences between them has important theoretical and practical implications and suggests that the assessment of brain and behavioral parameters should be performed using different cohorts.
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Affiliation(s)
- Shiran Salomon-Zimri
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel-Aviv University, Israel
| | - Ori Liraz
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel-Aviv University, Israel
| | - Daniel M Michaelson
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel-Aviv University, Israel
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Crofton EJ, Zhang Y, Green TA. Inoculation stress hypothesis of environmental enrichment. Neurosci Biobehav Rev 2015; 49:19-31. [PMID: 25449533 PMCID: PMC4305384 DOI: 10.1016/j.neubiorev.2014.11.017] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 10/28/2014] [Accepted: 11/21/2014] [Indexed: 01/28/2023]
Abstract
One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions.
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Affiliation(s)
- Elizabeth J Crofton
- Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, United States
| | - Yafang Zhang
- Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, United States
| | - Thomas A Green
- Center for Addiction Research, Mitchell Center for Neurodegenerative Diseases, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, United States.
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Alwis DS, Rajan R. Environmental enrichment and the sensory brain: the role of enrichment in remediating brain injury. Front Syst Neurosci 2014; 8:156. [PMID: 25228861 PMCID: PMC4151031 DOI: 10.3389/fnsys.2014.00156] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 08/12/2014] [Indexed: 01/08/2023] Open
Abstract
The brain's life-long capacity for experience-dependent plasticity allows adaptation to new environments or to changes in the environment, and to changes in internal brain states such as occurs in brain damage. Since the initial discovery by Hebb (1947) that environmental enrichment (EE) was able to confer improvements in cognitive behavior, EE has been investigated as a powerful form of experience-dependent plasticity. Animal studies have shown that exposure to EE results in a number of molecular and morphological alterations, which are thought to underpin changes in neuronal function and ultimately, behavior. These consequences of EE make it ideally suited for investigation into its use as a potential therapy after neurological disorders, such as traumatic brain injury (TBI). In this review, we aim to first briefly discuss the effects of EE on behavior and neuronal function, followed by a review of the underlying molecular and structural changes that account for EE-dependent plasticity in the normal (uninjured) adult brain. We then extend this review to specifically address the role of EE in the treatment of experimental TBI, where we will discuss the demonstrated sensorimotor and cognitive benefits associated with exposure to EE, and their possible mechanisms. Finally, we will explore the use of EE-based rehabilitation in the treatment of human TBI patients, highlighting the remaining questions regarding the effects of EE.
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Affiliation(s)
- Dasuni S Alwis
- Department of Physiology, Monash University Clayton, VIC, Australia
| | - Ramesh Rajan
- Department of Physiology, Monash University Clayton, VIC, Australia
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Hannan AJ. Environmental enrichment and brain repair: harnessing the therapeutic effects of cognitive stimulation and physical activity to enhance experience-dependent plasticity. Neuropathol Appl Neurobiol 2014; 40:13-25. [PMID: 24354721 DOI: 10.1111/nan.12102] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 11/29/2013] [Indexed: 12/12/2022]
Abstract
Environmental enrichment (EE) increases levels of novelty and complexity, inducing enhanced sensory, cognitive and motor stimulation. In wild-type rodents, EE has been found to have a range of effects, such as enhancing experience-dependent cellular plasticity and cognitive performance, relative to standard-housed controls. Whilst environmental enrichment is of course a relative term, dependent on the nature of control environmental conditions, epidemiological studies suggest that EE has direct clinical relevance to a range of neurological and psychiatric disorders. EE has been demonstrated to induce beneficial effects in animal models of a wide variety of brain disorders. The first evidence of beneficial effects of EE in a genetically targeted animal model was generated using Huntington's disease transgenic mice. Subsequent studies found that EE was also therapeutic in mouse models of Alzheimer's disease, consistent with epidemiological studies of relevant environmental modifiers. EE has also been found to ameliorate behavioural, cellular and molecular deficits in animal models of various neurological and psychiatric disorders, including Parkinson's disease, stroke, traumatic brain injury, epilepsy, multiple sclerosis, depression, schizophrenia and autism spectrum disorders. This review will focus on the effects of EE observed in animal models of neurodegenerative brain diseases, at molecular, cellular and behavioural levels. The proposal that EE may act synergistically with other approaches, such as drug and cell therapies, to facilitate brain repair will be discussed. I will also discuss the therapeutic potential of 'enviromimetics', drugs which mimic or enhance the therapeutic effects of cognitive activity and physical exercise, for both neuroprotection and brain repair.
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Affiliation(s)
- A J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne Brain Centre, Melbourne, Victoria, Australia
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Abstract
Apolipoprotein E4 (apoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), is less lipidated than its corresponding AD-benign form, apoE3, and it has been suggested that the pathological effects of apoE4 are mediated by lipid-related mechanisms. ATP-binding cassette transporters A1 and G1 (ABCA1 and ABCG1, respectively) are the most important apoE-lipidating proteins. The expression of these proteins, as well as that of apoE, is controlled by the transcription regulation retinoid X receptor (RXR)-liver X receptor (LXR) system. In the present study, we investigated the effects of the RXR agonist bexarotene on mRNA and protein levels of apoE, ABCA1, and ABCG1 in young, naive apoE3- and apoE4-targeted replacement mice and assessed the extent to which this reverses the apoE4-driven pathological phenotype. This investigation reveled that bexarotene increases the mRNA and protein levels of ABCA1 and ABCG1 in hippocampal neurons, but has no effect on the corresponding levels of apoE. These findings were associated with reversal of the lipidation deficiency of apoE4 and of the cognitive impairments of apoE4 mice in several tests. Furthermore, bexarotene reversed the apoE4-driven accumulation of Aβ42 and hyperphosphorylated tau in hippocampal neurons, as well as the apoE4-induced reduction in the levels of the presynaptic marker vesicular glutamatergic transporter 1 (VGluT1). In conclusion, the results show that treatment of apoE4 mice with the RXR agonist bexarotene reverses the apoE4-induced cognitive and neuronal impairments in vivo and suggest that this is due to reversal of the lipidation deficiency of apoE4. This puts forward the possibility that RXR activation and increased levels of ABCA1 and ABCG1 could be useful in the treatment of human apoE4 carriers.
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Blázquez G, Cañete T, Tobeña A, Giménez-Llort L, Fernández-Teruel A. Cognitive and emotional profiles of aged Alzheimer's disease (3×TgAD) mice: effects of environmental enrichment and sexual dimorphism. Behav Brain Res 2014; 268:185-201. [PMID: 24746486 DOI: 10.1016/j.bbr.2014.04.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/05/2014] [Indexed: 10/25/2022]
Abstract
Alzheimer's disease is a neurodegenerative disorder associated with age which represents the most common cause of dementia. It is characterized by an accelerated memory loss compared to normal aging, and deterioration of other cognitive abilities that interfere with mood, reason, judgment and language. The main neuropathological hallmarks of the disorder are β-amyloid (βA) plaques and neurofibrillary Tau tangles. Triple transgenic 3×TgAD mouse model develops βA and Tau pathologies in a progressive manner, with a specific temporal and anatomic profile mimicking the pattern that takes place in the human brain with AD, and showing cognitive alterations characteristic of the disease. Environmental enrichment treatment in mice induces behavioral and emotional reactivity changes, including cognitive improvements in some AD-related transgenic mice. The present work intended to characterize the behavioral profile of 3×TgAD mice at advanced stages of neuropathological development (12 and 15 months of age) and to investigate whether environmental enrichment administered during adulthood was able to modify some of their behavioral and cognitive alterations. Results show that, at advanced stages of the disease 3×TgAD mice show deficits of spatial learning acquisition, as well as short-term and working memory deficits, while displaying increased levels of anxiety/fearfulness and normal sensorimotor functions. 3×TgAD mice also show sexual dimorphism, as reflected by increased cognitive deficits in females and increased levels of novelty-induced behavioral inhibition in males. Environmental enrichment exerts some slight positive effects, by mainly improving the initial acquisition of the spatial learning and working memory in 12-month-old 3×TgAD mice. Such effects vary depending on the gender.
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Affiliation(s)
- Gloria Blázquez
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Spain.
| | - Toni Cañete
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Spain.
| | - Adolf Tobeña
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Spain.
| | - Lydia Giménez-Llort
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Spain.
| | - Alberto Fernández-Teruel
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, Institute of Neuroscience, Autonomous University of Barcelona, 08193 Bellaterra, Spain.
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Lattanzio F, Carboni L, Carretta D, Rimondini R, Candeletti S, Romualdi P. Human apolipoprotein E4 modulates the expression of Pin1, Sirtuin 1, and Presenilin 1 in brain regions of targeted replacement apoE mice. Neuroscience 2014; 256:360-9. [DOI: 10.1016/j.neuroscience.2013.10.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 10/09/2013] [Indexed: 01/06/2023]
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Hannan AJ. Nature, nurture and neurobiology: Gene–environment interactions in neuropsychiatric disorders. Neurobiol Dis 2013; 57:1-4. [DOI: 10.1016/j.nbd.2013.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Lestaevel P, Airault F, Racine R, Bensoussan H, Dhieux B, Delissen O, Manens L, Aigueperse J, Voisin P, Souidi M. Influence of environmental enrichment and depleted uranium on behaviour, cholesterol and acetylcholine in apolipoprotein E-deficient mice. J Mol Neurosci 2013; 53:469-79. [PMID: 23749703 DOI: 10.1007/s12031-013-0038-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 05/27/2013] [Indexed: 01/16/2023]
Abstract
Alzheimer's disease is associated with genetic risk factors, of which the apolipoprotein E (ApoE) is the most prevalent, and is affected by environmental factors that include education early in life and exposure to metals. The industrial and military use of depleted uranium (DU) resulted in an increase of its deposition in some areas and led to a possible environmental factor. The present study aims to ascertain the effects on the behaviour and the metabolism of cholesterol and acetylcholine of ApoE-/- mice exposed to enriched environment (EE) and exposed to DU (20 mg/L) for 14 weeks. Here we show that ApoE-/- mice were unaffected by the EE and their learning and memory were similar to those of the non-enriched ApoE-/- mice. ApoE-/- mice showed a significant decrease in total (-16 %) and free (-16 %) cholesterol in the entorhinal cortex in comparison to control wild-type mice. Whatever the housing conditions, the exposure to DU of ApoE-/- mice impaired working memory, but had no effect on anxiety-like behaviour, in comparison to control ApoE-/- mice. The exposure of ApoE-/- mice to DU also induced a trend toward higher total cholesterol content in the cerebral cortex (+15 %) compared to control ApoE-/- mice. In conclusion, these results demonstrate that enriched environment does not ameliorate neurobehaviour in ApoE-/- mice and that ApoE mutation induced specific effects on the brain cholesterol. These findings also suggested that DU exposure could modify the pathology in this ApoE model, with no influence of housing conditions.
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Affiliation(s)
- P Lestaevel
- Laboratoire de Radiotoxicologie Expérimentale (LRTOX), Service de Radiobiologie et d'Epidémiologie (SRBE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP no° 17, 92262 Fontenay-aux-Roses CEDEX and BP no° 166, 26702, Pierrelatte CEDEX, France,
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Antes R, Ezra-Elia R, Weinberger D, Solomon A, Ofri R, Michaelson DM. ApoE4 induces synaptic and ERG impairments in the retina of young targeted replacement apoE4 mice. PLoS One 2013; 8:e64949. [PMID: 23741431 PMCID: PMC3669199 DOI: 10.1371/journal.pone.0064949] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 04/19/2013] [Indexed: 11/18/2022] Open
Abstract
The vertebrate retina, which is part of the central nervous system, is a window into the brain. The present study investigated the extent to which the retina can be used as a model for studying the pathological effects of apolipoprotein E4 (apoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD). Immunohistochemical studies of retinas from young (4 months old) apoE4-targeted replacement mice and from corresponding mice which express the AD benign apoE3 allele, revealed that the density of the perikarya of the different classes of retinal neurons was not affected by apoE4. In contrast, the synaptic density of the retinal synaptic layers, which was assessed immunohistochemically and by immunoblot experiments, was significantly lower in the apoE4 than in the apoE3 mice. This was associated with reduced levels of the presynaptic vesicular glutamatergic transporter, VGluT1, but not of either the GABAergic vesicular transporter, VGaT, or the cholinergic vesicular transporter, VAChT, suggesting that the glutamatergic nerve terminals are preferentially affected by apoE4. In contrast, the post synaptic scaffold proteins PSD-95 and Gephyrin, which reside in excitatory and inhibitory synapses, respectively, were both elevated, and their ratio was not affected by apoE4. Electroretinogram (ERG) recordings revealed significant attenuation of mixed rod-cone responses in dark-adapted eyes of apoE4 mice. These findings suggest that the reduced ERG response in the apoE4 mice may be related to the observed decrease in the retinal nerve terminals and that the retina could be used as a novel model for non-invasive monitoring of the effects of apoE4 on the CNS.
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Affiliation(s)
- Ran Antes
- Department of Neurobiology, Tel Aviv University, Tel Aviv, Isreal
| | - Raaya Ezra-Elia
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
| | - Dov Weinberger
- Department of Ophthalmology, Rabin Medical Center, Petach Tikva, Israel
| | - Arie Solomon
- Goldschleger Eye Research Institute, Tel Aviv University, Tel Hashomer, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel
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Hu YS, Long N, Pigino G, Brady ST, Lazarov O. Molecular mechanisms of environmental enrichment: impairments in Akt/GSK3β, neurotrophin-3 and CREB signaling. PLoS One 2013; 8:e64460. [PMID: 23700479 PMCID: PMC3660250 DOI: 10.1371/journal.pone.0064460] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 04/15/2013] [Indexed: 11/18/2022] Open
Abstract
Experience of mice in a complex environment enhances neurogenesis and synaptic plasticity in the hippocampus of wild type and transgenic mice harboring familial Alzheimer's disease (FAD)-linked APPswe/PS1ΔE9. In FAD mice, this experience also reduces levels of tau hyperphosphorylation and oligomeric β-amyloid. Although environmental enrichment has significant effects on brain plasticity and neuropathology, the molecular mechanisms underlying these effects are unknown. Here we show that environmental enrichment upregulates the Akt pathway, leading to the downregulation of glycogen synthase kinase 3β (GSK3β), in wild type but not FAD mice. Several neurotrophic signaling pathways are activated in the hippocampus of both wild type and FAD mice, including brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF), and this increase is accompanied by the upregulation of the BDNF receptor, tyrosine kinase B (TrkB). Interestingly, neurotrophin-3 (NT-3) is upregulated in the brains of wild type mice but not FAD mice, while insulin growth factor-1 (IGF-1) is upregulated exclusively in the brains of FAD mice. Upregulation of neurotrophins is accompanied by the increase of N-Methyl-D-aspartic acid (NMDA) receptors in the hippocampus following environmental enrichment. Most importantly, we observed a significant increase in levels of cAMP response element- binding (CREB) transcripts in the hippocampus of wild type and FAD mice following environmental enrichment. However, CREB phosphorylation, a critical step for the initiation of learning and memory-required gene transcription, takes place in the hippocampus of wild type but not of FAD mice. These results suggest that experience of wild type mice in a complex environmental upregulates critical signaling that play a major role in learning and memory in the hippocampus. However, in FAD mice, some of these pathways are impaired and cannot be rescued by environmental enrichment.
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Affiliation(s)
- Yuan-Shih Hu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Nancy Long
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Gustavo Pigino
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Scott T. Brady
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Orly Lazarov
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Liraz O, Boehm-Cagan A, Michaelson DM. ApoE4 induces Aβ42, tau, and neuronal pathology in the hippocampus of young targeted replacement apoE4 mice. Mol Neurodegener 2013; 8:16. [PMID: 23684315 PMCID: PMC3659080 DOI: 10.1186/1750-1326-8-16] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 04/18/2013] [Indexed: 12/26/2022] Open
Abstract
Background Recent findings suggest that the pathological effects of apoE4, the most prevalent genetic risk factor for Alzheimer’s disease (AD), start many years before the onset of the disease and are already detectable at a young age. In the present study we investigated the extent to which such pathological and cognitive impairments also occur in young apoE4 mice. Results This study revealed that the levels of the presynaptic glutamatergic vesicular transporter, VGlut, in the CA3, CA1, and DG hippocampal subfields were lower in hippocampal neurons of young (4-month-old) apoE4-targeted replacement mice than in those of the apoE3 mice. In contrast, the corresponding inhibitory GABAergic nerve terminals and perikarya were not affected by apoE4. This synaptic effect was associated with hyperphosphorylation of tau in these neurons. In addition, apoE4 increased the accumulation of neuronal Aβ42 and induced mitochondrial changes, both of which were specifically pronounced in CA3 neurons. Spatial navigation behavioral studies revealed that these hippocampal pathological effects of apoE4 are associated with corresponding behavioral impairments. Time-course studies revealed that the effects of apoE4 on tau hyperphosphorylation and the mitochondria were already apparent at the age of 1 month and that the apoE4-driven accumulation of neuronal Aβ and reduced VGlut levels evolve later and are apparent at the age of 2–4 months. Furthermore, the levels of tau phosphorylation decrease in apoE3 mice and increase in apoE4 mice between 1 and 4 months, whereas the levels of Aβ42 decrease in apoE3 mice and are not affected in apoE4 mice over the same time period. Conclusions These findings show that apoE4 stimulates the accumulation of Aβ42 and hyperphosphorylated tau and reduces the levels of VGlut in hippocampal neurons of young apoE4-targeted replacement mice and that these neurochemical effects are associated with cognitive impairments. This model is not associated with hypothesis-driven mechanistic manipulations and is thus most suitable for unbiased studies of the mechanisms underlying the pathological effects of apoE4.
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Affiliation(s)
- Ori Liraz
- Department of Neurobiology, The George S, Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel
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Apolipoprotein E, not fibrillar β-amyloid, reduces cerebral glucose metabolism in normal aging. J Neurosci 2013; 32:18227-33. [PMID: 23238736 DOI: 10.1523/jneurosci.3266-12.2012] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The ε4 allele of the polymorphic apolipoprotein E gene is associated with increased risk of Alzheimer's disease (AD), deposition of β-amyloid (Aβ), and reduction in cerebral glucose metabolism in asymptomatic people. Although ApoE4 may exert an effect on AD risk through amyloidogenic pathways, whether its effect on glucose metabolism is related to Aβ is unknown. To answer this question, we examined data from 175 cognitively normal older people (mean age, 77; 87 men, 88 women) in the Alzheimer's disease neuroimaging initiative studied concurrently with [(18)F]flurodeoxyglucose (FDG) positron emission tomography measures of glucose metabolism and the radiotracer [(18)F]florbetapir, an imaging agent which labels fibrillar Aβ in vivo. Based on a threshold value of florbetapir uptake determined in separate samples, subjects were categorized as florbetapir+ or florbetapir-. Glucose metabolism was measured as a continuous variable in a group of regions of interest (ROIs) selected a priori based on their involvement in AD, and also by using a whole-brain voxelwise approach. Among this sample, 29% of subjects were florbetapir+ and 23% were ApoE4 carriers. As expected, there was a significant association between ApoE4 genotype and florbetapir positivity. Florbetapir status, however, was not significantly associated with glucose metabolism, but the ApoE4 genotype was associated with lower metabolism in both voxelwise and ROI approaches. These results show that ApoE genotype, and not aggregated fibrillar forms of Aβ, contributes to reduced glucose metabolism in aging and adds to a growing list of neural consequences of ApoE that do not appear to be related to Aβ.
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Patel DI, White LJ. Effect of 10-day forced treadmill training on neurotrophic factors in experimental autoimmune encephalomyelitis. Appl Physiol Nutr Metab 2013; 38:194-9. [DOI: 10.1139/apnm-2012-0303] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The impact of exercise on disease progression in multiple sclerosis (MS) is unclear. In the present study, we evaluated the clinical effects of forced wheel running on rats induced with experimental autoimmune encephalomyelitis (EAE), a model of MS. Female Lewis rats (n = 40) were randomly assigned to 1 of 4 groups prior to inoculation: EAE exercise (EAE-Ex), EAE sedentary (EAE-Sed), control exercise (Con-Ex), or control sedentary (Con-Sed). Exercise training was composed of forced treadmill running at increasing intensity across 10 consecutive days. No significant differences in clinical disability were observed in the EAE groups at the conclusion of this study. Furthermore, no significant differences in brain mass were observed across groups. Analysis of brain tissue proteins revealed that tumour necrosis factor-α (TNF-α) concentrations were higher in both EAE groups compared with the control groups (p < 0.05); however, no significant differences were seen between the EAE-Ex and EAE-Sed groups. The Con-Ex group had lower whole-brain TNF-α compared with the Con-Sed group (p < 0.05). Nerve growth factor concentrations were greater in the EAE-Ex animals compared with both control groups (p < 0.05 for both). No differences were seen in brain-derived neurotrophic factor. Our results indicate that aerobic exercise can modulate the proteins associated with disability in EAE; however, further research is required to understand the total impact of exercise on EAE disability and disease progression.
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Affiliation(s)
- Darpan I. Patel
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA; School of Nursing, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive (M/C 7949), San Antonio, TX 78229, USA
| | - Lesley J. White
- Department of Kinesiology, University of Georgia, Athens, GA 30602, USA
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Hooghiemstra AM, Eggermont LHP, Scheltens P, van der Flier WM, Scherder EJA. Exercise and early-onset Alzheimer's disease: theoretical considerations. Dement Geriatr Cogn Dis Extra 2012; 2:132-45. [PMID: 22590474 PMCID: PMC3347875 DOI: 10.1159/000335493] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND/AIMS Although studies show a negative relationship between physical activity and the risk for cognitive impairment and late-onset Alzheimer's disease, studies concerning early-onset Alzheimer's disease (EOAD) are lacking. This review aims to justify the value of exercise interventions in EOAD by providing theoretical considerations that include neurobiological processes. METHODS A literature search on key words related to early-onset dementia, exercise, imaging, neurobiological mechanisms, and cognitive reserve was performed. RESULTS/CONCLUSION Brain regions and neurobiological processes contributing to the positive effects of exercise are affected in EOAD and, thus, provide theoretical support for exercise interventions in EOAD. Finally, we present the design of a randomized controlled trial currently being conducted in early-onset dementia patients.
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Trachtenberg AJ, Filippini N, Ebmeier KP, Smith SM, Karpe F, Mackay CE. The effects of APOE on the functional architecture of the resting brain. Neuroimage 2012; 59:565-72. [DOI: 10.1016/j.neuroimage.2011.07.059] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 06/08/2011] [Accepted: 07/20/2011] [Indexed: 10/17/2022] Open
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