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Qu L, Xu S, Lan Z, Fang S, Xu Y, Zhu X. Apolipoprotein E in Alzheimer's Disease: Focus on Synaptic Function and Therapeutic Strategy. Mol Neurobiol 2024:10.1007/s12035-024-04449-1. [PMID: 39214953 DOI: 10.1007/s12035-024-04449-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/05/2024] [Indexed: 09/04/2024]
Abstract
Synaptic dysfunction is a critical pathological feature in the early phase of Alzheimer's disease (AD) that precedes typical hallmarks of AD, including beta-amyloid (Aβ) plaques and neurofibrillary tangles. However, the underlying mechanism of synaptic dysfunction remains incompletely defined. Apolipoprotein E (APOE) has been shown to play a key role in the pathogenesis of AD, and the ε4 allele of APOE remains the strongest genetic risk factor for sporadic AD. It is widely recognized that APOE4 accelerates the development of Aβ and tau pathology in AD. Recent studies have indicated that APOE affects synaptic function through a variety of pathways. Here, we summarize the mechanism of modulating synapses by various APOE isoforms and demonstrate the therapeutic potential by targeting APOE4 for AD treatment.
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Affiliation(s)
- Longjie Qu
- Department of Neurology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, 210008, China
| | - Shuai Xu
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210008, China
| | - Zhen Lan
- Department of Neurology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, 210008, China
| | - Shuang Fang
- Department of Neurology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, 210008, China
| | - Yun Xu
- Department of Neurology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, 210008, China
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210008, China
- State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing, 210008, China
- Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
- Nanjing Neurology Clinical Medical Center, Nanjing, 210008, China
| | - Xiaolei Zhu
- Department of Neurology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing, 210008, China.
- Department of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, 210008, China.
- State Key Laboratory of Pharmaceutical Biotechnology and Institute of Translational Medicine for Brain Critical Diseases, Nanjing University, Nanjing, 210008, China.
- Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China.
- Nanjing Neurology Clinical Medical Center, Nanjing, 210008, China.
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2
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Almeida VN. Somatostatin and the pathophysiology of Alzheimer's disease. Ageing Res Rev 2024; 96:102270. [PMID: 38484981 DOI: 10.1016/j.arr.2024.102270] [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] [Received: 07/18/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024]
Abstract
Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.
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Affiliation(s)
- Victor N Almeida
- Institute of Psychiatry, Faculty of Medicine, University of São Paulo (USP), Brazil; Faculty of Languages, Federal University of Minas Gerais (UFMG), Brazil.
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3
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Greco GA, Rock M, Amontree M, Lanfranco MF, Korthas H, Hong SH, Turner RS, Rebeck GW, Conant K. CCR5 deficiency normalizes TIMP levels, working memory, and gamma oscillation power in APOE4 targeted replacement mice. Neurobiol Dis 2023; 179:106057. [PMID: 36878326 PMCID: PMC10291850 DOI: 10.1016/j.nbd.2023.106057] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/16/2023] [Accepted: 02/26/2023] [Indexed: 03/07/2023] Open
Abstract
The APOE4 allele increases the risk for Alzheimer's disease (AD) in a dose-dependent manner and is also associated with cognitive decline in non-demented elderly controls. In mice with targeted gene replacement (TR) of murine APOE with human APOE3 or APOE4, the latter show reduced neuronal dendritic complexity and impaired learning. APOE4 TR mice also show reduced gamma oscillation power, a neuronal population activity which is important to learning and memory. Published work has shown that brain extracellular matrix (ECM) can reduce neuroplasticity as well as gamma power, while attenuation of ECM can instead enhance this endpoint. In the present study we examine human cerebrospinal fluid (CSF) samples from APOE3 and APOE4 individuals and brain lysates from APOE3 and APOE4 TR mice for levels of ECM effectors that can increase matrix deposition and restrict neuroplasticity. We find that CCL5, a molecule linked to ECM deposition in liver and kidney, is increased in CSF samples from APOE4 individuals. Levels of tissue inhibitor of metalloproteinases (TIMPs), which inhibit the activity of ECM-degrading enzymes, are also increased in APOE4 CSF as well as astrocyte supernatants brain lysates from APOE4 TR mice. Importantly, as compared to APOE4/wild-type heterozygotes, APOE4/CCR5 knockout heterozygotes show reduced TIMP levels and enhanced EEG gamma power. The latter also show improved learning and memory, suggesting that the CCR5/CCL5 axis could represent a therapeutic target for APOE4 individuals.
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Affiliation(s)
- Griffin A Greco
- Georgetown University School of Medicine (GUMC), Department of Pharmacology, United States of America
| | | | - Matthew Amontree
- GUMC, United States of America; Interdisciplinary Program in Neuroscience, United States of America
| | | | - Holly Korthas
- Interdisciplinary Program in Neuroscience, United States of America
| | - Sung Hyeok Hong
- GUMC, Department of Biochemistry and Molecular & Cellular Biology, United States of America
| | | | - G William Rebeck
- Interdisciplinary Program in Neuroscience, United States of America; GUMC, Department of Neuroscience, United States of America
| | - Katherine Conant
- Interdisciplinary Program in Neuroscience, United States of America; GUMC, Department of Neuroscience, United States of America.
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4
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Barisano G, Kisler K, Wilkinson B, Nikolakopoulou AM, Sagare AP, Wang Y, Gilliam W, Huuskonen MT, Hung ST, Ichida JK, Gao F, Coba MP, Zlokovic BV. A "multi-omics" analysis of blood-brain barrier and synaptic dysfunction in APOE4 mice. J Exp Med 2022; 219:e20221137. [PMID: 36040482 PMCID: PMC9435921 DOI: 10.1084/jem.20221137] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 02/02/2023] Open
Abstract
Apolipoprotein E4 (APOE4), the main susceptibility gene for Alzheimer's disease, leads to blood-brain barrier (BBB) breakdown in humans and mice. Remarkably, BBB dysfunction predicts cognitive decline and precedes synaptic deficits in APOE4 human carriers. How APOE4 affects BBB and synaptic function at a molecular level, however, remains elusive. Using single-nucleus RNA-sequencing and phosphoproteome and proteome analysis, we show that APOE4 compared with APOE3 leads to an early disruption of the BBB transcriptome in 2-3-mo-old APOE4 knock-in mice, followed by dysregulation in protein signaling networks controlling cell junctions, cytoskeleton, clathrin-mediated transport, and translation in brain endothelium, as well as transcription and RNA splicing suggestive of DNA damage in pericytes. Changes in BBB signaling mechanisms paralleled an early, progressive BBB breakdown and loss of pericytes, which preceded postsynaptic interactome disruption and behavioral deficits that developed 2-5 mo later. Thus, dysregulated signaling mechanisms in endothelium and pericytes in APOE4 mice reflect a molecular signature of a progressive BBB failure preceding changes in synaptic function and behavior.
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Affiliation(s)
- Giuseppe Barisano
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA
| | - Kassandra Kisler
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Brent Wilkinson
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Angeliki Maria Nikolakopoulou
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Abhay P. Sagare
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Yaoming Wang
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - William Gilliam
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Mikko T. Huuskonen
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Shu-Ting Hung
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at University of Southern California, Los Angeles, CA
| | - Justin K. Ichida
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research at University of Southern California, Los Angeles, CA
| | - Fan Gao
- Caltech Bioinformatics Resource Center, Caltech, Pasadena, CA
| | - Marcelo P. Coba
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Berislav V. Zlokovic
- Department of Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Alzheimer’s Disease Research Center, Keck School of Medicine, University of Southern California, Los Angeles, CA
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5
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Steele OG, Stuart AC, Minkley L, Shaw K, Bonnar O, Anderle S, Penn AC, Rusted J, Serpell L, Hall C, King S. A multi-hit hypothesis for an APOE4-dependent pathophysiological state. Eur J Neurosci 2022; 56:5476-5515. [PMID: 35510513 PMCID: PMC9796338 DOI: 10.1111/ejn.15685] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/31/2022] [Accepted: 04/25/2022] [Indexed: 01/01/2023]
Abstract
The APOE gene encoding the Apolipoprotein E protein is the single most significant genetic risk factor for late-onset Alzheimer's disease. The APOE4 genotype confers a significantly increased risk relative to the other two common genotypes APOE3 and APOE2. Intriguingly, APOE4 has been associated with neuropathological and cognitive deficits in the absence of Alzheimer's disease-related amyloid or tau pathology. Here, we review the extensive literature surrounding the impact of APOE genotype on central nervous system dysfunction, focussing on preclinical model systems and comparison of APOE3 and APOE4, given the low global prevalence of APOE2. A multi-hit hypothesis is proposed to explain how APOE4 shifts cerebral physiology towards pathophysiology through interconnected hits. These hits include the following: neurodegeneration, neurovascular dysfunction, neuroinflammation, oxidative stress, endosomal trafficking impairments, lipid and cellular metabolism disruption, impaired calcium homeostasis and altered transcriptional regulation. The hits, individually and in combination, leave the APOE4 brain in a vulnerable state where further cumulative insults will exacerbate degeneration and lead to cognitive deficits in the absence of Alzheimer's disease pathology and also a state in which such pathology may more easily take hold. We conclude that current evidence supports an APOE4 multi-hit hypothesis, which contributes to an APOE4 pathophysiological state. We highlight key areas where further study is required to elucidate the complex interplay between these individual mechanisms and downstream consequences, helping to frame the current landscape of existing APOE-centric literature.
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Affiliation(s)
| | | | - Lucy Minkley
- School of Life SciencesUniversity of SussexBrightonUK
| | - Kira Shaw
- School of Life SciencesUniversity of SussexBrightonUK
| | - Orla Bonnar
- School of Life SciencesUniversity of SussexBrightonUK
| | | | | | | | | | | | - Sarah King
- School of PsychologyUniversity of SussexBrightonUK
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6
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Sepulveda J, Luo N, Nelson M, Ng CAS, Rebeck GW. Independent APOE4 knock-in mouse models display reduced brain APOE protein, altered neuroinflammation, and simplification of dendritic spines. J Neurochem 2022; 163:247-259. [PMID: 35838553 PMCID: PMC9613529 DOI: 10.1111/jnc.15665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/06/2022] [Accepted: 06/26/2022] [Indexed: 11/28/2022]
Abstract
APOE is an immunomodulator in the brain and the major genetic risk factor for late-onset Alzheimer's disease (AD). Targeted replacement APOE mice (APOE-TR) have been a useful tool to study the effects of APOE isoforms on brain neurochemistry and activity prior to and during AD. We use newly available APOE knock-in mice (JAX-APOE) to compare phenotypes associated with APOE4 across models. Similar to APOE4-TR mice, JAX-E4 mouse brains showed 27% lower levels of APOE protein compared with JAX-E3 (p < 0.001). We analyzed several neuroinflammatory molecules that have been associated with APOE genotype. SerpinA3 was much higher in APOE4-TR mice to APOE3-TR mice, but this effect was not seen in JAX-APOE mice. There were higher levels of IL-3 in JAX-E4 brains compared with JAX-E3, but other neuroinflammatory markers (IL6, TNFα) were not affected by APOE genotype. In terms of neuronal structure, basal dendritic spine density in the entorhinal cortex was 39% lower in JAX-E4 mice compared with JAX-E3 mice (p < 0.001), again similar to APOE-TR mice. One-week treatment with ibuprofen significantly increased dendritic spine density in the JAX-E4 mice, consistent with our previous finding in APOE-TR mice. Behaviorally, there was no effect of APOE genotype on Barnes Maze learning and memory in 6-month-old JAX-APOE mice. Overall, the experiments performed in JAX-APOE mice validated findings from APOE-TR mice, identifying particularly strong effects of APOE4 genotype on lower APOE protein levels and simplified neuron structure. These data demonstrate pathways that could promote susceptibility of APOE4 brains to AD pathological changes.
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Affiliation(s)
- Jordy Sepulveda
- Department of Pharmacology & Physiology, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington D.C. 20007
| | - Nancy Luo
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington D.C. 20007
| | - Matthew Nelson
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington D.C. 20007
| | - Christi Anne S. Ng
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington D.C. 20007
| | - G. William Rebeck
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road N.W., Washington D.C. 20007
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7
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Staurenghi E, Leoni V, Lo Iacono M, Sottero B, Testa G, Giannelli S, Leonarduzzi G, Gamba P. ApoE3 vs. ApoE4 Astrocytes: A Detailed Analysis Provides New Insights into Differences in Cholesterol Homeostasis. Antioxidants (Basel) 2022; 11:2168. [PMID: 36358540 PMCID: PMC9686673 DOI: 10.3390/antiox11112168] [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: 10/12/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 07/30/2023] Open
Abstract
The strongest genetic risk factor for sporadic Alzheimer's disease (AD) is the presence of the ε4 allele of the apolipoprotein E (ApoE) gene, the major apolipoprotein involved in brain cholesterol homeostasis. Being astrocytes the main producers of cholesterol and ApoE in the brain, we investigated the impact of the ApoE genotype on astrocyte cholesterol homeostasis. Two mouse astrocytic cell lines expressing the human ApoE3 or ApoE4 isoform were employed. Gas chromatography-mass spectrometry (GC-MS) analysis pointed out that the levels of total cholesterol, cholesterol precursors, and various oxysterols are altered in ApoE4 astrocytes. Moreover, the gene expression analysis of more than 40 lipid-related genes by qRT-PCR showed that certain genes are up-regulated (e.g., CYP27A1) and others down-regulated (e.g., PPARγ, LXRα) in ApoE4, compared to ApoE3 astrocytes. Beyond confirming the significant reduction in the levels of PPARγ, a key transcription factor involved in the maintenance of lipid homeostasis, Western blotting showed that both intracellular and secreted ApoE levels are altered in ApoE4 astrocytes, as well as the levels of receptors and transporters involved in lipid uptake/efflux (ABCA1, LDLR, LRP1, and ApoER2). Data showed that the ApoE genotype clearly affects astrocytic cholesterol homeostasis; however, further investigation is needed to clarify the mechanisms underlying these differences and the consequences on neighboring cells. Indeed, drug development aimed at restoring cholesterol homeostasis could be a potential strategy to counteract AD.
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Affiliation(s)
- Erica Staurenghi
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Valerio Leoni
- Laboratory of Clinical Biochemistry, Hospital Pius XI of Desio, ASST-Brianza, University of Milano-Bicocca, 20126 Monza, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Monza, Italy
| | - Marco Lo Iacono
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Barbara Sottero
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Serena Giannelli
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
| | - Paola Gamba
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, 10043 Turin, Italy
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Fernández-Calle R, Konings SC, Frontiñán-Rubio J, García-Revilla J, Camprubí-Ferrer L, Svensson M, Martinson I, Boza-Serrano A, Venero JL, Nielsen HM, Gouras GK, Deierborg T. APOE in the bullseye of neurodegenerative diseases: impact of the APOE genotype in Alzheimer's disease pathology and brain diseases. Mol Neurodegener 2022; 17:62. [PMID: 36153580 PMCID: PMC9509584 DOI: 10.1186/s13024-022-00566-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 08/29/2022] [Indexed: 02/06/2023] Open
Abstract
ApoE is the major lipid and cholesterol carrier in the CNS. There are three major human polymorphisms, apoE2, apoE3, and apoE4, and the genetic expression of APOE4 is one of the most influential risk factors for the development of late-onset Alzheimer's disease (AD). Neuroinflammation has become the third hallmark of AD, together with Amyloid-β plaques and neurofibrillary tangles of hyperphosphorylated aggregated tau protein. This review aims to broadly and extensively describe the differential aspects concerning apoE. Starting from the evolution of apoE to how APOE's single-nucleotide polymorphisms affect its structure, function, and involvement during health and disease. This review reflects on how APOE's polymorphisms impact critical aspects of AD pathology, such as the neuroinflammatory response, particularly the effect of APOE on astrocytic and microglial function and microglial dynamics, synaptic function, amyloid-β load, tau pathology, autophagy, and cell-cell communication. We discuss influential factors affecting AD pathology combined with the APOE genotype, such as sex, age, diet, physical exercise, current therapies and clinical trials in the AD field. The impact of the APOE genotype in other neurodegenerative diseases characterized by overt inflammation, e.g., alpha- synucleinopathies and Parkinson's disease, traumatic brain injury, stroke, amyotrophic lateral sclerosis, and multiple sclerosis, is also addressed. Therefore, this review gathers the most relevant findings related to the APOE genotype up to date and its implications on AD and CNS pathologies to provide a deeper understanding of the knowledge in the APOE field.
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Affiliation(s)
- Rosalía Fernández-Calle
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Sabine C. Konings
- Department of Experimental Medical Science, Experimental Dementia Research Unit, Lund University, Lund, Sweden
| | - Javier Frontiñán-Rubio
- Oxidative Stress and Neurodegeneration Group, Faculty of Medicine, Universidad de Castilla-La Mancha, Ciudad Real, Spain
| | - Juan García-Revilla
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
- Departamento de Bioquímica Y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Lluís Camprubí-Ferrer
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Martina Svensson
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Isak Martinson
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Antonio Boza-Serrano
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
- Departamento de Bioquímica Y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - José Luís Venero
- Departamento de Bioquímica Y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Henrietta M. Nielsen
- Department of Biochemistry and Biophysics at, Stockholm University, Stockholm, Sweden
| | - Gunnar K. Gouras
- Department of Experimental Medical Science, Experimental Dementia Research Unit, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Department of Experimental Medical Science, Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
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9
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Liu Q, Liu H, Zhang S, Yang Q, Shen L, Jiao B. Cerebrospinal Fluid Synaptosomal-Associated Protein 25 Levels in Patients with Alzheimer’s Disease: A Meta-Analysis. J Alzheimers Dis 2022; 89:121-132. [PMID: 35848017 DOI: 10.3233/jad-215696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Several studies have shown increased levels of cerebrospinal fluid (CSF) synaptosomal-associated protein 25 (SNAP-25) in patients with Alzheimer’s disease (AD). However, results have been inconsistent thus far. Objective: We conducted meta-analyses summarizing the associations of CSF SNAP-25 levels with AD to assess the utility of SNAP-25 as a novel biomarker for AD. Methods: We conducted a meta-analysis of differences in CSF SNAP-25 levels in patients with AD or mild cognitive impairment (MCI) and in cognitively healthy controls (HC). We calculated pooled correlation coefficients comparing SNAP-25 levels and total tau (T-tau) or hyperphosphorylated tau (P-tau) in CSF. Results: Eight studies enrolling 1,162 individuals (423 AD, 275 MCI, 464 HC) were included for quantitative analysis. Patients with AD (ratio of means [RoM] = 1.50, 95% confidence interval [CI]: 1.30,1.74) and MCI (RoM = 1.45, 95% CI: 1.12,1.87) had increased levels of CSF SNAP-25 as compared to HC. The difference in CSF SNAP-25 levels when comparing AD and MCI (RoM = 1.05, 95% CI: 0.96,1.14) was not statistically significant but showed a trend toward significance. Statistically significant correlations were found when comparing CSF SNAP-25 with CSF T-tau (Spearman correlation coefficient, ρ=0.78; ρ=0.66; ρ=0.69, respectively) and P-tau (ρ=0.66; ρ=0.70; ρ=0.62, respectively) levels in patients with AD, MCI, and HC. Conclusion: Increased CSF SNAP-25 levels differentiated patients with AD or MCI from controls, suggesting the utility of this biomarker in the early diagnosis of AD.
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Affiliation(s)
- Qianqian Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hui Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Sizhe Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qijie Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China
- Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China
- Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Bin Jiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China
- Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China
- Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
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10
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Targa Dias Anastacio H, Matosin N, Ooi L. Neuronal hyperexcitability in Alzheimer's disease: what are the drivers behind this aberrant phenotype? Transl Psychiatry 2022; 12:257. [PMID: 35732622 PMCID: PMC9217953 DOI: 10.1038/s41398-022-02024-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/01/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to loss of cognitive abilities and ultimately, death. With no cure available, limited treatments mostly focus on symptom management. Identifying early changes in the disease course may provide new therapeutic targets to halt or reverse disease progression. Clinical studies have shown that cortical and hippocampal hyperactivity are a feature shared by patients in the early stages of disease, progressing to hypoactivity during later stages of neurodegeneration. The exact mechanisms causing neuronal excitability changes are not fully characterized; however, animal and cell models have provided insights into some of the factors involved in this phenotype. In this review, we summarize the evidence for neuronal excitability changes over the course of AD onset and progression and the molecular mechanisms underpinning these differences. Specifically, we discuss contributors to aberrant neuronal excitability, including abnormal levels of intracellular Ca2+ and glutamate, pathological amyloid β (Aβ) and tau, genetic risk factors, including APOE, and impaired inhibitory interneuron and glial function. In light of recent research indicating hyperexcitability could be a predictive marker of cognitive dysfunction, we further argue that the hyperexcitability phenotype could be leveraged to improve the diagnosis and treatment of AD, and present potential targets for future AD treatment development.
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Affiliation(s)
- Helena Targa Dias Anastacio
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Natalie Matosin
- grid.510958.0Illawarra Health and Medical Research Institute, Wollongong, NSW 2522 Australia ,grid.1007.60000 0004 0486 528XMolecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia. .,Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
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11
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Abstract
The brain, as one of the most lipid-rich organs, heavily relies on lipid transport and distribution to maintain homeostasis and neuronal function. Lipid transport mediated by lipoprotein particles, which are complex structures composed of apolipoproteins and lipids, has been thoroughly characterized in the periphery. Although lipoproteins in the central nervous system (CNS) were reported over half a century ago, the identification of APOE4 as the strongest genetic risk factor for Alzheimer's disease has accelerated investigation of the biology and pathobiology of lipoproteins in the CNS. This review provides an overview of the different components of lipoprotein particles, in particular apolipoproteins, and their involvements in both physiological functions and pathological mechanisms in the CNS.
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Affiliation(s)
| | - Yuka A Martens
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA;
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA;
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12
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Chen B, Marquez-Nostra B, Belitzky E, Toyonaga T, Tong J, Huang Y, Cai Z. PET Imaging in Animal Models of Alzheimer’s Disease. Front Neurosci 2022; 16:872509. [PMID: 35685772 PMCID: PMC9171374 DOI: 10.3389/fnins.2022.872509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
The successful development and translation of PET imaging agents targeting β-amyloid plaques and hyperphosphorylated tau tangles have allowed for in vivo detection of these hallmarks of Alzheimer’s disease (AD) antemortem. Amyloid and tau PET have been incorporated into the A/T/N scheme for AD characterization and have become an integral part of ongoing clinical trials to screen patients for enrollment, prove drug action mechanisms, and monitor therapeutic effects. Meanwhile, preclinical PET imaging in animal models of AD can provide supportive information for mechanistic studies. With the recent advancement of gene editing technologies and AD animal model development, preclinical PET imaging in AD models will further facilitate our understanding of AD pathogenesis/progression and the development of novel treatments. In this study, we review the current state-of-the-art in preclinical PET imaging using animal models of AD and suggest future research directions.
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13
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Staurenghi E, Giannelli S, Testa G, Sottero B, Leonarduzzi G, Gamba P. Cholesterol Dysmetabolism in Alzheimer's Disease: A Starring Role for Astrocytes? Antioxidants (Basel) 2021; 10:antiox10121890. [PMID: 34943002 PMCID: PMC8750262 DOI: 10.3390/antiox10121890] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 01/19/2023] Open
Abstract
In recent decades, the impairment of cholesterol metabolism in the pathogenesis of Alzheimer’s disease (AD) has been intensively investigated, and it has been recognized to affect amyloid β (Aβ) production and clearance, tau phosphorylation, neuroinflammation and degeneration. In particular, the key role of cholesterol oxidation products, named oxysterols, has emerged. Brain cholesterol metabolism is independent from that of peripheral tissues and it must be preserved in order to guarantee cerebral functions. Among the cells that help maintain brain cholesterol homeostasis, astrocytes play a starring role since they deliver de novo synthesized cholesterol to neurons. In addition, other physiological roles of astrocytes are to modulate synaptic transmission and plasticity and support neurons providing energy. In the AD brain, astrocytes undergo significant morphological and functional changes that contribute to AD onset and development. However, the extent of this contribution and the role played by oxysterols are still unclear. Here we review the current understanding of the physiological role exerted by astrocytes in the brain and their contribution to AD pathogenesis. In particular, we focus on the impact of cholesterol dysmetabolism on astrocyte functions suggesting new potential approaches to develop therapeutic strategies aimed at counteracting AD development.
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14
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APOE4 Affects Basal and NMDAR-Mediated Protein Synthesis in Neurons by Perturbing Calcium Homeostasis. J Neurosci 2021; 41:8686-8709. [PMID: 34475200 DOI: 10.1523/jneurosci.0435-21.2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 08/15/2021] [Accepted: 08/22/2021] [Indexed: 01/24/2023] Open
Abstract
Apolipoprotein E (APOE), one of the primary lipoproteins in the brain has three isoforms in humans, APOE2, APOE3, and APOE4. APOE4 is the most well-established risk factor increasing the predisposition for Alzheimer's disease (AD). The presence of the APOE4 allele alone is shown to cause synaptic defects in neurons and recent studies have identified multiple pathways directly influenced by APOE4. However, the mechanisms underlying APOE4-induced synaptic dysfunction remain elusive. Here, we report that the acute exposure of primary cortical neurons or synaptoneurosomes to APOE4 leads to a significant decrease in global protein synthesis. Primary cortical neurons were derived from male and female embryos of Sprague Dawley (SD) rats or C57BL/6J mice. Synaptoneurosomes were prepared from P30 male SD rats. APOE4 treatment also abrogates the NMDA-mediated translation response indicating an alteration of synaptic signaling. Importantly, we demonstrate that both APOE3 and APOE4 generate a distinct translation response which is closely linked to their respective calcium signature. Acute exposure of neurons to APOE3 causes a short burst of calcium through NMDA receptors (NMDARs) leading to an initial decrease in protein synthesis which quickly recovers. Contrarily, APOE4 leads to a sustained increase in calcium levels by activating both NMDARs and L-type voltage-gated calcium channels (L-VGCCs), thereby causing sustained translation inhibition through eukaryotic translation elongation factor 2 (eEF2) phosphorylation, which in turn disrupts the NMDAR response. Thus, we show that APOE4 affects basal and activity-mediated protein synthesis responses in neurons by affecting calcium homeostasis.SIGNIFICANCE STATEMENT Defective protein synthesis has been shown as an early defect in familial Alzheimer's disease (AD). However, this has not been studied in the context of sporadic AD, which constitutes the majority of cases. In our study, we show that Apolipoprotein E4 (APOE4), the predominant risk factor for AD, inhibits global protein synthesis in neurons. APOE4 also affects NMDA activity-mediated protein synthesis response, thus inhibiting synaptic translation. We also show that the defective protein synthesis mediated by APOE4 is closely linked to the perturbation of calcium homeostasis caused by APOE4 in neurons. Thus, we propose the dysregulation of protein synthesis as one of the possible molecular mechanisms to explain APOE4-mediated synaptic and cognitive defects. Hence, the study not only suggests an explanation for the APOE4-mediated predisposition to AD, it also bridges the gap in understanding APOE4-mediated pathology.
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15
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Kotredes KP, Oblak A, Pandey RS, Lin PBC, Garceau D, Williams H, Uyar A, O’Rourke R, O’Rourke S, Ingraham C, Bednarczyk D, Belanger M, Cope Z, Foley KE, Logsdon BA, Mangravite LM, Sukoff Rizzo SJ, Territo PR, Carter GW, Sasner M, Lamb BT, Howell GR. Uncovering Disease Mechanisms in a Novel Mouse Model Expressing Humanized APOEε4 and Trem2*R47H. Front Aging Neurosci 2021; 13:735524. [PMID: 34707490 PMCID: PMC8544520 DOI: 10.3389/fnagi.2021.735524] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
Late-onset Alzheimer's disease (AD; LOAD) is the most common human neurodegenerative disease, however, the availability and efficacy of disease-modifying interventions is severely lacking. Despite exceptional efforts to understand disease progression via legacy amyloidogenic transgene mouse models, focus on disease translation with innovative mouse strains that better model the complexity of human AD is required to accelerate the development of future treatment modalities. LOAD within the human population is a polygenic and environmentally influenced disease with many risk factors acting in concert to produce disease processes parallel to those often muted by the early and aggressive aggregate formation in popular mouse strains. In addition to extracellular deposits of amyloid plaques and inclusions of the microtubule-associated protein tau, AD is also defined by synaptic/neuronal loss, vascular deficits, and neuroinflammation. These underlying processes need to be better defined, how the disease progresses with age, and compared to human-relevant outcomes. To create more translatable mouse models, MODEL-AD (Model Organism Development and Evaluation for Late-onset AD) groups are identifying and integrating disease-relevant, humanized gene sequences from public databases beginning with APOEε4 and Trem2*R47H, two of the most powerful risk factors present in human LOAD populations. Mice expressing endogenous, humanized APOEε4 and Trem2*R47H gene sequences were extensively aged and assayed using a multi-disciplined phenotyping approach associated with and relative to human AD pathology. Robust analytical pipelines measured behavioral, transcriptomic, metabolic, and neuropathological phenotypes in cross-sectional cohorts for progression of disease hallmarks at all life stages. In vivo PET/MRI neuroimaging revealed regional alterations in glycolytic metabolism and vascular perfusion. Transcriptional profiling by RNA-Seq of brain hemispheres identified sex and age as the main sources of variation between genotypes including age-specific enrichment of AD-related processes. Similarly, age was the strongest determinant of behavioral change. In the absence of mouse amyloid plaque formation, many of the hallmarks of AD were not observed in this strain. However, as a sensitized baseline model with many additional alleles and environmental modifications already appended, the dataset from this initial MODEL-AD strain serves an important role in establishing the individual effects and interaction between two strong genetic risk factors for LOAD in a mouse host.
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Affiliation(s)
| | - Adrian Oblak
- Stark Neurosciences Research Institute, School of Medicine, Indiana University Bloomington, Indianapolis, IN, United States
| | | | - Peter Bor-Chian Lin
- Stark Neurosciences Research Institute, School of Medicine, Indiana University Bloomington, Indianapolis, IN, United States
| | - Dylan Garceau
- The Jackson Laboratory, Bar Harbor, ME, United States
| | | | - Asli Uyar
- The Jackson Laboratory, Bar Harbor, ME, United States
| | - Rita O’Rourke
- The Jackson Laboratory, Bar Harbor, ME, United States
| | | | - Cynthia Ingraham
- Stark Neurosciences Research Institute, School of Medicine, Indiana University Bloomington, Indianapolis, IN, United States
| | | | | | - Zackary Cope
- Department of Medicine—Aging Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Kate E. Foley
- The Jackson Laboratory, Bar Harbor, ME, United States
| | | | | | - Stacey J. Sukoff Rizzo
- Department of Medicine—Aging Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Paul R. Territo
- Stark Neurosciences Research Institute, School of Medicine, Indiana University Bloomington, Indianapolis, IN, United States
| | | | | | - Bruce T. Lamb
- Stark Neurosciences Research Institute, School of Medicine, Indiana University Bloomington, Indianapolis, IN, United States
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16
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Konings SC, Torres-Garcia L, Martinsson I, Gouras GK. Astrocytic and Neuronal Apolipoprotein E Isoforms Differentially Affect Neuronal Excitability. Front Neurosci 2021; 15:734001. [PMID: 34621153 PMCID: PMC8490647 DOI: 10.3389/fnins.2021.734001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/23/2021] [Indexed: 11/25/2022] Open
Abstract
Synaptic changes and neuronal network dysfunction are among the earliest changes in Alzheimer’s disease (AD). Apolipoprotein E4 (ApoE4), the major genetic risk factor in AD, has been shown to be present at synapses and to induce hyperexcitability in mouse knock-in brain regions vulnerable to AD. ApoE in the brain is mainly generated by astrocytes, however, neurons can also produce ApoE under stress conditions such as aging. The potential synaptic function(s) of ApoE and whether the cellular source of ApoE might affect neuronal excitability remain poorly understood. Therefore, the aim of this study was to elucidate the synaptic localization and effects on neuronal activity of the two main human ApoE isoforms from different cellular sources in control and AD-like in vitro cultured neuron models. In this study ApoE is seen to localize at or near to synaptic terminals. Additionally, we detected a cellular source-specific effect of ApoE isoforms on neuronal activity measured by live cell Ca2+ imaging. Neuronal activity increases after acute but not long-term administration of ApoE4 astrocyte medium. In contrast, ApoE expressed by neurons appears to induce the highest neuronal firing rate in the presence of ApoE3, rather than ApoE4. Moreover, increased neuronal activity in APP/PS1 AD transgenic compared to wild-type neurons is seen in the absence of astrocytic ApoE and the presence of astrocytic ApoE4, but not ApoE3. In summary, ApoE can target synapses and differentially induce changes in neuronal activity depending on whether ApoE is produced by astrocytes or neurons. Astrocytic ApoE induces the strongest neuronal firing with ApoE4, while the most active and efficient neuronal activity induced by neuronal ApoE is caused by ApoE3. ApoE isoforms also differentially affect neuronal activity in AD transgenic compared to wild-type neurons.
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Affiliation(s)
- Sabine C Konings
- Experimental Dementia Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Laura Torres-Garcia
- Experimental Dementia Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Isak Martinsson
- Experimental Dementia Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Gunnar K Gouras
- Experimental Dementia Research Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
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17
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Tsamou M, Pistollato F, Roggen EL. A Tau-Driven Adverse Outcome Pathway Blueprint Toward Memory Loss in Sporadic (Late-Onset) Alzheimer's Disease with Plausible Molecular Initiating Event Plug-Ins for Environmental Neurotoxicants. J Alzheimers Dis 2021; 81:459-485. [PMID: 33843671 DOI: 10.3233/jad-201418] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The worldwide prevalence of sporadic (late-onset) Alzheimer's disease (sAD) is dramatically increasing. Aging and genetics are important risk factors, but systemic and environmental factors contribute to this risk in a still poorly understood way. Within the frame of BioMed21, the Adverse Outcome Pathway (AOP) concept for toxicology was recommended as a tool for enhancing human disease research and accelerating translation of data into human applications. Its potential to capture biological knowledge and to increase mechanistic understanding about human diseases has been substantiated since. In pursuit of the tau-cascade hypothesis, a tau-driven AOP blueprint toward the adverse outcome of memory loss is proposed. Sequences of key events and plausible key event relationships, triggered by the bidirectional relationship between brain cholesterol and glucose dysmetabolism, and contributing to memory loss are captured. To portray how environmental factors may contribute to sAD progression, information on chemicals and drugs, that experimentally or epidemiologically associate with the risk of AD and mechanistically link to sAD progression, are mapped on this AOP. The evidence suggests that chemicals may accelerate disease progression by plugging into sAD relevant processes. The proposed AOP is a simplified framework of key events and plausible key event relationships representing one specific aspect of sAD pathology, and an attempt to portray chemical interference. Other sAD-related AOPs (e.g., Aβ-driven AOP) and a better understanding of the impact of aging and genetic polymorphism are needed to further expand our mechanistic understanding of early AD pathology and the potential impact of environmental and systemic risk factors.
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18
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Cao J, Huang M, Guo L, Zhu L, Hou J, Zhang L, Pero A, Ng S, El Gaamouch F, Elder G, Sano M, Goate A, Tcw J, Haroutunian V, Zhang B, Cai D. MicroRNA-195 rescues ApoE4-induced cognitive deficits and lysosomal defects in Alzheimer's disease pathogenesis. Mol Psychiatry 2021; 26:4687-4701. [PMID: 32632205 PMCID: PMC7785685 DOI: 10.1038/s41380-020-0824-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 06/03/2020] [Accepted: 06/16/2020] [Indexed: 12/18/2022]
Abstract
Our recent findings link the apolipoprotein E4 (ApoE4)-specific changes in brain phosphoinositol biphosphate (PIP2) homeostasis to the susceptibility of developing Alzheimer's Disease (AD). In the present study, we have identified miR-195 as a top micro-RNA candidate involved in the ApoE/PIP2 pathway using miRNA profiles in human ROSMAP datasets and mouse microarray studies. Further validation studies have demonstrated that levels of miR-195 are significantly lower in human brain tissue of ApoE4+/- patients with clinical diagnosis of mild cognitive impairment (MCI) or early AD when compared to ApoE4-/- subjects. In addition, brain miR-195 levels are reduced along with disease progression from normal aging to early AD, and cerebrospinal fluid (CSF) miR-195 levels of MCI subjects are positively correlated with cognitive performances as measured by mini-mental status examination (MMSE) and negatively correlated with CSF tau levels, suggesting the involvement of miR-195 in early development of AD with a potential impact on cognition. Similar differences in miR-195 levels are seen in ApoE4+/+ mouse hippocampal brain tissue and cultured neurons when compared to ApoE3+/+ counterparts. Over-expressing miR-195 reduces expression levels of its top predicted target synaptojanin 1 (synj1), a brain PIP2-degrading enzyme. Furthermore, elevating miR-195 ameliorates cognitive deficits, amyloid plaque burden, and tau hyper-phosphorylation in ApoE4+/+ mice. In addition, elevating miR-195 rescues AD-related lysosomal defects in inducible pluripotent stem cells (iPSCs)-derived brain cells of ApoE4+/+ AD subjects while inhibiting miR-195 exacerbates these phenotypes. Together, our data uncover a novel regulatory mechanism of miR-195 targeted at ApoE4-associated brain PIP2 dyshomeostasis, cognitive deficits, and AD pathology.
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Affiliation(s)
- Jiqing Cao
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Min Huang
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Lei Guo
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Li Zhu
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jianwei Hou
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Larry Zhang
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Adriana Pero
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Sabrina Ng
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Cornell University, Ithaca, NY, 14850, USA
| | - Farida El Gaamouch
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Gregory Elder
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Mary Sano
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Alzheimer Disease Rsearch Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Alison Goate
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Ronald M. Loeb Center for Alzheimer's disease, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Julia Tcw
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Ronald M. Loeb Center for Alzheimer's disease, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Alzheimer Disease Rsearch Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- James J Peters VA Medical Center, MIRECC, Bronx, NY, 10468, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Dongming Cai
- James J Peters VA Medical Center, Research & Development, Bronx, NY, 10468, USA.
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Alzheimer Disease Rsearch Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Ronald M. Loeb Center for Alzheimer's disease, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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19
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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: 12] [Impact Index Per Article: 4.0] [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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20
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Har-Paz I, Arieli E, Moran A. ApoE4 attenuates cortical neuronal activity in young behaving apoE4 rats. Neurobiol Dis 2021; 155:105373. [PMID: 33932558 DOI: 10.1016/j.nbd.2021.105373] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 10/21/2022] Open
Abstract
The E4 allele of apolipoprotein E (apoE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). However, apoE4 may cause innate brain abnormalities before the appearance of AD-related neuropathology. Understanding these primary dysfunctions is vital for the early detection of AD and the development of therapeutic strategies. Recently we reported impaired extra-hippocampal memory in young apoE4 mice, a deficit that was correlated with attenuated structural pre-synaptic plasticity in cortical and subcortical regions. Here we tested the hypothesis that these early structural deficits impact learning via changes in basal and stimuli evoked neuronal activity. We recorded extracellular neuronal activity from the gustatory cortex (GC) of three-month-old humanized apoE4 (hApoE4) and wildtype rats expressing rat apoE (rAE), before and after conditioned taste aversion (CTA) training. Despite normal sucrose drinking behavior before CTA, young hApoE4 rats showed impaired CTA learning, consistent with our previous results in target-replacement apoE4 mice. This behavioral deficit was correlated with decreased basal and taste-evoked firing rates in both putative excitatory and inhibitory GC neurons. Further taste coding analyses at the single neuron and ensemble levels revealed that GC neurons of the hApoE4 group correctly classified tastes, but were unable to undergo plasticity to support learning. These results suggest that apoE4 impacts brain excitability and plasticity early in life that may act as an initiator for later AD pathologies.
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Affiliation(s)
- Ilona Har-Paz
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Elor Arieli
- Department of Neurobiology, The School of Neurobiology, Biochemistry and Biophysics, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anan Moran
- Department of Neurobiology, The School of Neurobiology, Biochemistry and Biophysics, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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21
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Toro CA, Hansen J, Siddiq MM, Johnson K, Zhao W, Azulai D, Das DK, Bauman W, Sebra R, Cai D, Iyengar R, Cardozo CP. The Human ApoE4 Variant Reduces Functional Recovery and Neuronal Sprouting After Incomplete Spinal Cord Injury in Male Mice. Front Cell Neurosci 2021; 15:626192. [PMID: 33679326 PMCID: PMC7930340 DOI: 10.3389/fncel.2021.626192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/01/2021] [Indexed: 01/01/2023] Open
Abstract
Spinal cord injury (SCI) is a devastating form of neurotrauma. Patients who carry one or two apolipoprotein E (ApoE)4 alleles show worse functional outcomes and longer hospital stays after SCI, but the cellular and molecular underpinnings for this genetic link remain poorly understood. Thus, there is a great need to generate animal models to accurately replicate the genetic determinants of outcomes after SCI to spur development of treatments that improve physical function. Here, we examined outcomes after a moderate contusion SCI of transgenic mice expressing human ApoE3 or ApoE4. ApoE4 mice have worse locomotor function and coordination after SCI. Histological examination revealed greater glial staining in ApoE4 mice after SCI associated with reduced levels of neuronal sprouting markers. Bulk RNA sequencing revealed that subcellular processes (SCPs), such as extracellular matrix organization and inflammatory responses, were highly ranked among upregulated genes at 7 days after SCI in ApoE4 variants. Conversely, SCPs related to neuronal action potential and neuron projection development were increased in ApoE3 mice at 21 days. In summary, our results reveal a clinically relevant SCI mouse model that recapitulates the influence of ApoE genotypes on post SCI function in individuals who carry these alleles and suggest that the mechanisms underlying worse recovery for ApoE4 animals involve glial activation and loss of sprouting and synaptic activity.
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Affiliation(s)
- Carlos A Toro
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - Jens Hansen
- Department of Pharmacological Sciences, Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Mustafa M Siddiq
- Department of Pharmacological Sciences, Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Kaitlin Johnson
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - Wei Zhao
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - Daniella Azulai
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - Dibash K Das
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - William Bauman
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Spinal Cord Injuries and Disorders System of Care, United States Department of Veterans Affairs, New York, NY, United States
| | - Robert Sebra
- Department of Genetics and Genomic Studies, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Dongming Cai
- Department of Neurology, James J. Peters VA Medical Center, New York, NY, United States.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Ravi Iyengar
- Department of Pharmacological Sciences, Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Christopher P Cardozo
- National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, New York, NY, United States.,Department of Rehabilitative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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22
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Chen F, Chen H, Chen Y, Wei W, Sun Y, Zhang L, Cui L, Wang Y. Dysfunction of the SNARE complex in neurological and psychiatric disorders. Pharmacol Res 2021; 165:105469. [PMID: 33524541 DOI: 10.1016/j.phrs.2021.105469] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/30/2020] [Accepted: 01/24/2021] [Indexed: 02/07/2023]
Abstract
The communication between neurons constitutes the basis of all neural activities, and synaptic vesicle exocytosis is the fundamental biological event that mediates most communication between neurons in the central nervous system. The SNARE complex is the core component of the protein machinery that facilitates the fusion of synaptic vesicles with presynaptic terminals and thereby the release of neurotransmitters. In synapses, each release event is dependent on the assembly of the SNARE complex. In recent years, basic research on the SNARE complex has provided a clearer understanding of the mechanism underlying the formation of the SNARE complex and its role in vesicle formation. Emerging evidence indicates that abnormal expression or dysfunction of the SNARE complex in synapse physiology might contribute to abnormal neurotransmission and ultimately to synaptic dysfunction. Clinical research using postmortem tissues suggests that SNARE complex dysfunction is correlated with various neurological diseases, and some basic research has also confirmed the important role of the SNARE complex in the pathology of these diseases. Genetic and pharmacogenetic studies suggest that the SNARE complex and individual proteins might represent important molecular targets in neurological disease. In this review, we summarize the recent progress toward understanding the SNARE complex in regulating membrane fusion events and provide an update of the recent discoveries from clinical and basic research on the SNARE complex in neurodegenerative, neuropsychiatric, and neurodevelopmental diseases.
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Affiliation(s)
- Feng Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Huiyi Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yanting Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Wenyan Wei
- Department of Gerontology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Yuanhong Sun
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Lu Zhang
- The First Clinical College, Guangdong Medical University, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.
| | - Yan Wang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China; Key Laboratory of Biomedical Information Engineering of Ministry of Education, Biomedical Informatics & Genomics Center, School of Life Science and Technology, Xi'an Jiao tong University, Xi'an, China.
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23
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Liang X, Wu H, Colt M, Guo X, Pluimer B, Zeng J, Dong S, Zhao Z. Microglia and its Genetics in Alzheimer's Disease. Curr Alzheimer Res 2021; 18:676-688. [PMID: 34749609 PMCID: PMC9790807 DOI: 10.2174/1567205018666211105140732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/30/2021] [Accepted: 07/03/2021] [Indexed: 12/27/2022]
Abstract
Alzheimer's Disease (AD) is the most prevalent form of dementia across the world. While its discovery and pathological manifestations are centered on protein aggregations of amyloid- beta (Aβ) and hyperphosphorylated tau protein, neuroinflammation has emerged in the last decade as a main component of the disease in terms of both pathogenesis and progression. As the main innate immune cell type in the central nervous system (CNS), microglia play a very important role in regulating neuroinflammation, which occurs commonly in neurodegenerative conditions, including AD. Under inflammatory response, microglia undergo morphological changes and status transition from homeostatic to activated forms. Different microglia subtypes displaying distinct genetic profiles have been identified in AD, and these signatures often link to AD risk genes identified from the genome-wide association studies (GWAS), such as APOE and TREM2. Furthermore, many AD risk genes are highly enriched in microglia and specifically influence the functions of microglia in pathogenesis, e.g. releasing inflammatory cytokines and clearing Aβ. Therefore, building up a landscape of these risk genes in microglia, based on current preclinical studies and in the context of their pathogenic or protective effects, would largely help us to understand the complex etiology of AD and provide new insight into the unmet need for effective treatment.
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Affiliation(s)
- Xinyan Liang
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
| | - Haijian Wu
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310009, China
| | - Mark Colt
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
| | - Xinying Guo
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
| | - Brock Pluimer
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
| | - Jianxiong Zeng
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
| | - Shupeng Dong
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Shanghai Institute of Immunology; Department of Immunology and Microbiology, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhen Zhao
- Center for Neurodegeneration and Regeneration, Zilkha Neurogenetic Institute and Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
- Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA
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24
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Shinohara M, Kanekiyo T, Tachibana M, Kurti A, Shinohara M, Fu Y, Zhao J, Han X, Sullivan PM, Rebeck GW, Fryer JD, Heckman MG, Bu G. APOE2 is associated with longevity independent of Alzheimer's disease. eLife 2020; 9:e62199. [PMID: 33074098 PMCID: PMC7588231 DOI: 10.7554/elife.62199] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/13/2020] [Indexed: 12/24/2022] Open
Abstract
Although the ε2 allele of apolipoprotein E (APOE2) benefits longevity, its mechanism is not understood. The protective effects of the APOE2 on Alzheimer's disease (AD) risk, particularly through their effects on amyloid or tau accumulation, may confound APOE2 effects on longevity. Herein, we showed that the association between APOE2 and longer lifespan persisted irrespective of AD status, including its neuropathology, by analyzing clinical datasets as well as animal models. Notably, APOE2 was associated with preserved activity during aging, which also associated with lifespan. In animal models, distinct apoE isoform levels, where APOE2 has the highest, were correlated with activity levels, while some forms of cholesterol and triglycerides were associated with apoE and activity levels. These results indicate that APOE2 can contribute to longevity independent of AD. Preserved activity would be an early-observable feature of APOE2-mediated longevity, where higher levels of apoE2 and its-associated lipid metabolism might be involved.
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Affiliation(s)
- Mitsuru Shinohara
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- Department of Aging Neurobiology, National Center for Geriatrics and GerontologyAichiJapan
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- Neuroscience Graduate Program, Mayo ClinicJacksonvilleUnited States
| | - Masaya Tachibana
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- United Graduate School of Child Development, Osaka UniversityOsakaJapan
| | - Aishe Kurti
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
| | - Motoko Shinohara
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
| | - Yuan Fu
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
| | - Jing Zhao
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San AntonioSan AntonioUnited States
| | - Patrick M Sullivan
- Duke University School of Medicine, Durham Veterans Health Administration Medical Center's Geriatric Research, Education and Clinical CenterDurhamUnited States
| | - G William Rebeck
- Department of Neuroscience, Georgetown University Medical CenterWashingtonUnited States
| | - John D Fryer
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- Neuroscience Graduate Program, Mayo ClinicJacksonvilleUnited States
| | - Michael G Heckman
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- Division of Biomedical Statistics and Informatics, Mayo ClinicJacksonvilleUnited States
| | - Guojun Bu
- Department of Neuroscience, Mayo ClinicJacksonvilleUnited States
- Neuroscience Graduate Program, Mayo ClinicJacksonvilleUnited States
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25
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Tible M, Sandelius Å, Höglund K, Brinkmalm A, Cognat E, Dumurgier J, Zetterberg H, Hugon J, Paquet C, Blennow K. Dissection of synaptic pathways through the CSF biomarkers for predicting Alzheimer disease. Neurology 2020; 95:e953-e961. [PMID: 32586895 DOI: 10.1212/wnl.0000000000010131] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 02/15/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To assess the ability of a combination of synaptic CSF biomarkers to separate Alzheimer disease (AD) and non-AD disorders and to help in the differential diagnosis between neurocognitive diseases. METHODS This was a retrospective cross-sectional monocentric study. All participants explored with CSF assessments for neurocognitive decline were invited to participate. After complete clinical and imaging evaluations, 243 patients were included. CSF synaptic (GAP-43, neurogranin, SNAP-25 total, SNAP-25aa40, synaptotagmin-1) and AD biomarkers were blindly quantified with ELISA or mass spectrometry. Statistical analysis compared CSF levels between the various groups of AD dementias (n = 81), mild cognitive impairment (MCI)-AD (n = 30), other MCI (n = 49), other dementias (OD) (n = 49), and neurologic controls (n = 35) and their discriminatory powers. RESULTS All synaptic biomarkers were significantly increased in patients with MCI-AD and AD-dementia compared to the other groups. All synaptic biomarkers could efficiently discriminate AD dementias from OD (AUC ≥0.80). All but synaptotagmin were also able to discriminate patients with MCI-AD from controls (area under the curve [AUC] ≥0.85) and those with AD dementias from controls (AUC ≥0.80). Overall, CSF SNAP-25aa40 had the highest discriminative power (AUC 0.93 between patients with AD dementias and controls or OD, AUC 0.90 between those with MCI-AD and controls). Higher levels were associated with 2 alleles of APOE ε4. CONCLUSION All synaptic biomarkers tested had a good discriminatory power to distinguish patients with AD abnormal CSF from those with non-AD disorders. SNAP25aa40 demonstrated the highest power to discriminate AD CSF-positive patients from patients without AD and neurologic controls in this cohort. CLASSIFICATION OF EVIDENCE This retrospective study provides Class II evidence that CSF synaptic biomarkers discriminate patients with AD from those without AD.
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Affiliation(s)
- Marion Tible
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Åsa Sandelius
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Kina Höglund
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Ann Brinkmalm
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Emmanuel Cognat
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Julien Dumurgier
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Henrik Zetterberg
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Jacques Hugon
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
| | - Claire Paquet
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France.
| | - Kaj Blennow
- From the Université de Paris INSERM U1144 (M.T., E.C., J.D., J.H., C.P.), France; Clinical Neurochemistry Laboratory (A.S., K.H., A.B., H.Z., K.B.), Sahlgrenska University Hospital; Institute of Neuroscience and Physiology (A.S., K.H., A.B., H.Z., K.B.), Department of Psychiatry and Neurochemistry, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; and Center of Cognitive Neurology (E.C., J.D., J.H., C.P.), Lariboisière Fernand-Widal Hospital, APHP, Paris, France
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Larramona-Arcas R, González-Arias C, Perea G, Gutiérrez A, Vitorica J, García-Barrera T, Gómez-Ariza JL, Pascua-Maestro R, Ganfornina MD, Kara E, Hudry E, Martinez-Vicente M, Vila M, Galea E, Masgrau R. Sex-dependent calcium hyperactivity due to lysosomal-related dysfunction in astrocytes from APOE4 versus APOE3 gene targeted replacement mice. Mol Neurodegener 2020; 15:35. [PMID: 32517777 PMCID: PMC7285605 DOI: 10.1186/s13024-020-00382-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 05/25/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The apolipoprotein E (APOE) gene exists in three isoforms in humans: APOE2, APOE3 and APOE4. APOE4 causes structural and functional alterations in normal brains, and is the strongest genetic risk factor of the sporadic form of Alzheimer's disease (LOAD). Research on APOE4 has mainly focused on the neuronal damage caused by defective cholesterol transport and exacerbated amyloid-β and Tau pathology. The impact of APOE4 on non-neuronal cell functions has been overlooked. Astrocytes, the main producers of ApoE in the healthy brain, are building blocks of neural circuits, and Ca2+ signaling is the basis of their excitability. Because APOE4 modifies membrane-lipid composition, and lipids regulate Ca2+ channels, we determined whether APOE4 dysregulates Ca2+signaling in astrocytes. METHODS Ca2+ signals were recorded in astrocytes in hippocampal slices from APOE3 and APOE4 gene targeted replacement male and female mice using Ca2+ imaging. Mechanistic analyses were performed in immortalized astrocytes. Ca2+ fluxes were examined with pharmacological tools and Ca2+ probes. APOE3 and APOE4 expression was manipulated with GFP-APOE vectors and APOE siRNA. Lipidomics of lysosomal and whole-membranes were also performed. RESULTS We found potentiation of ATP-elicited Ca2+responses in APOE4 versus APOE3 astrocytes in male, but not female, mice. The immortalized astrocytes modeled the male response, and showed that Ca2+ hyperactivity associated with APOE4 is caused by dysregulation of Ca2+ handling in lysosomal-enriched acidic stores, and is reversed by the expression of APOE3, but not of APOE4, pointing to loss of function due to APOE4 malfunction. Moreover, immortalized APOE4 astrocytes are refractory to control of Ca2+ fluxes by extracellular lipids, and present distinct lipid composition in lysosomal and plasma membranes. CONCLUSIONS Immortalized APOE4 versus APOE3 astrocytes present: increased Ca2+ excitability due to lysosome dysregulation, altered membrane lipidomes and intracellular cholesterol distribution, and impaired modulation of Ca2+ responses upon changes in extracellular lipids. Ca2+ hyperactivity associated with APOE4 is found in astrocytes from male, but not female, targeted replacement mice. The study suggests that, independently of Aβ and Tau pathologies, altered astrocyte excitability might contribute to neural-circuit hyperactivity depending on APOE allele, sex and lipids, and supports lysosome-targeted therapies to rescue APOE4 phenotypes in LOAD.
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Affiliation(s)
- Raquel Larramona-Arcas
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, and, Institut de Neurociències (INc), Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Catalonia Spain
| | - Candela González-Arias
- Cajal Institute, Consejo Superior de Investigaciones Científicas (CSIC), 28002 Madrid, Spain
| | - Gertrudis Perea
- Cajal Institute, Consejo Superior de Investigaciones Científicas (CSIC), 28002 Madrid, Spain
| | - Antonia Gutiérrez
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Instituto de Investigación Biomedica de Málaga (IBIMA), Universidad de Málaga, 29071 Málaga, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
| | - Javier Vitorica
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41012 Sevilla, Spain
| | - Tamara García-Barrera
- Departamento de Química, Facultad de Ciencias Experimentales, Campus de El Carmen, Centro de Investigación en Recursos Naturales, Salud y Medio Ambiente (RENSMA), Universidad de Huelva, 21007 Huelva, Spain
| | - José Luis Gómez-Ariza
- Departamento de Química, Facultad de Ciencias Experimentales, Campus de El Carmen, Centro de Investigación en Recursos Naturales, Salud y Medio Ambiente (RENSMA), Universidad de Huelva, 21007 Huelva, Spain
| | - Raquel Pascua-Maestro
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid-CSIC, 43007 Valladolid, Spain
| | - María Dolores Ganfornina
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid-CSIC, 43007 Valladolid, Spain
| | - Eleanna Kara
- Alzheimer’s Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129 USA
- Present Address: Institute of Neuropathology, University Hospital of Zurich, 8091 Zurich, Switzerland
| | - Eloise Hudry
- Alzheimer’s Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129 USA
| | - Marta Martinez-Vicente
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain
| | - Miquel Vila
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, and, Institut de Neurociències (INc), Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Catalonia Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Neurodegenerative Diseases Research Group, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain
- ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Catalonia Spain
| | - Elena Galea
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, and, Institut de Neurociències (INc), Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Catalonia Spain
- ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Catalonia Spain
| | - Roser Masgrau
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, and, Institut de Neurociències (INc), Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Catalonia Spain
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Perdigão C, Barata MA, Araújo MN, Mirfakhar FS, Castanheira J, Guimas Almeida C. Intracellular Trafficking Mechanisms of Synaptic Dysfunction in Alzheimer's Disease. Front Cell Neurosci 2020; 14:72. [PMID: 32362813 PMCID: PMC7180223 DOI: 10.3389/fncel.2020.00072] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 03/12/2020] [Indexed: 12/15/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease characterized by progressive memory loss. Although AD neuropathological hallmarks are extracellular amyloid plaques and intracellular tau tangles, the best correlate of disease progression is synapse loss. What causes synapse loss has been the focus of several researchers in the AD field. Synapses become dysfunctional before plaques and tangles form. Studies based on early-onset familial AD (eFAD) models have supported that synaptic transmission is depressed by β-amyloid (Aβ) triggered mechanisms. Since eFAD is rare, affecting only 1% of patients, research has shifted to the study of the most common late-onset AD (LOAD). Intracellular trafficking has emerged as one of the pathways of LOAD genes. Few studies have assessed the impact of trafficking LOAD genes on synapse dysfunction. Since endocytic traffic is essential for synaptic function, we reviewed Aβ-dependent and independent mechanisms of the earliest synaptic dysfunction in AD. We have focused on the role of intraneuronal and secreted Aβ oligomers, highlighting the dysfunction of endocytic trafficking as an Aβ-dependent mechanism of synapse dysfunction in AD. Here, we reviewed the LOAD trafficking genes APOE4, ABCA7, BIN1, CD2AP, PICALM, EPH1A, and SORL1, for which there is a synaptic link. We conclude that in eFAD and LOAD, the earliest synaptic dysfunctions are characterized by disruptions of the presynaptic vesicle exo- and endocytosis and of postsynaptic glutamate receptor endocytosis. While in eFAD synapse dysfunction seems to be triggered by Aβ, in LOAD, there might be a direct synaptic disruption by LOAD trafficking genes. To identify promising therapeutic targets and biomarkers of the earliest synaptic dysfunction in AD, it will be necessary to join efforts in further dissecting the mechanisms used by Aβ and by LOAD genes to disrupt synapses.
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Affiliation(s)
- Catarina Perdigão
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Mariana A Barata
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Margarida N Araújo
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Farzaneh S Mirfakhar
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Jorge Castanheira
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Cláudia Guimas Almeida
- Laboratory Neuronal Trafficking in Aging, CEDOC Chronic Diseases Research Center, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
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28
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Lewandowski CT, Maldonado Weng J, LaDu MJ. Alzheimer's disease pathology in APOE transgenic mouse models: The Who, What, When, Where, Why, and How. Neurobiol Dis 2020; 139:104811. [PMID: 32087290 DOI: 10.1016/j.nbd.2020.104811] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/01/2020] [Accepted: 02/18/2020] [Indexed: 02/07/2023] Open
Abstract
The focus on amyloid plaques and neurofibrillary tangles has yielded no Alzheimer's disease (AD) modifying treatments in the past several decades, despite successful studies in preclinical mouse models. This inconsistency has caused a renewed focus on improving the fidelity and reliability of AD mouse models, with disparate views on how this improvement can be accomplished. However, the interactive effects of the universal biological variables of AD, which include age, APOE genotype, and sex, are often overlooked. Age is the greatest risk factor for AD, while the ε4 allele of the human APOE gene, encoding apolipoprotein E, is the greatest genetic risk factor. Sex is the final universal biological variable of AD, as females develop AD at almost twice the rate of males and, importantly, female sex exacerbates the effects of APOE4 on AD risk and rate of cognitive decline. Therefore, this review evaluates the importance of context for understanding the role of APOE in preclinical mouse models. Specifically, we detail how human AD pathology is mirrored in current transgenic mouse models ("What") and describe the critical need for introducing human APOE into these mouse models ("Who"). We next outline different methods for introducing human APOE into mice ("How") and highlight efforts to develop temporally defined and location-specific human apoE expression models ("When" and "Where"). We conclude with the importance of choosing the human APOE mouse model relevant to the question being addressed, using the selection of transgenic models for testing apoE-targeted therapeutics as an example ("Why").
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Affiliation(s)
- Cutler T Lewandowski
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, 833 S. Wood St., Chicago, IL 60612, USA.
| | - Juan Maldonado Weng
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., Chicago, IL 60612, USA.
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., Chicago, IL 60612, USA.
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29
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APOE in the normal brain. Neurobiol Dis 2020; 136:104724. [PMID: 31911114 DOI: 10.1016/j.nbd.2019.104724] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/19/2019] [Accepted: 12/31/2019] [Indexed: 12/25/2022] Open
Abstract
The APOE4 protein affects the primary neuropathological markers of Alzheimer's disease (AD): amyloid plaques, neurofibrillary tangles, and gliosis. These interactions have been investigated to understand the strong effect of APOE genotype on risk of AD. However, APOE genotype has strong effects on processes in normal brains, in the absence of the hallmarks of AD. We propose that CNS APOE is involved in processes in the normal brains that in later years apply specifically to processes of AD pathogenesis. We review the differences of the APOE protein found in the CNS compared to the plasma, including post-translational modifications (glycosylation, lipidation, multimer formation), focusing on ways that the common APOE isoforms differ from each other. We also review structural and functional studies of young human brains and control APOE knock-in mouse brains. These approaches demonstrate the effects of APOE genotype on microscopic neuron structure, gross brain structure, and behavior, primarily related to the hippocampal areas. By focusing on the effects of APOE genotype on normal brain function, approaches can be pursued to identify biomarkers of APOE dysfunction, to promote normal functions of the APOE4 isoform, and to prevent the accumulation of the pathologic hallmarks of AD with aging.
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30
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Mathews PM, Levy E. Exosome Production Is Key to Neuronal Endosomal Pathway Integrity in Neurodegenerative Diseases. Front Neurosci 2019; 13:1347. [PMID: 31911768 PMCID: PMC6920185 DOI: 10.3389/fnins.2019.01347] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/29/2019] [Indexed: 12/28/2022] Open
Abstract
Dysfunction of the endosomal–lysosomal system is a prominent pathogenic factor in Alzheimer’s disease (AD) and other neurodevelopmental and neurodegenerative disorders. We and others have extensively characterized the neuronal endosomal pathway pathology that results from either triplication of the amyloid-β precursor protein (APP) gene in Down syndrome (DS) or from expression of the apolipoprotein E ε4 allele (APOE4), the greatest genetic risk factor for late-onset AD. More recently brain exosomes, extracellular vesicles that are generated within and released from endosomal compartments, have been shown to be altered in DS and by APOE4 expression. In this review, we discuss the emerging data arguing for an interdependence between exosome production and endosomal pathway integrity in the brain. In vitro and in vivo studies indicate that altered trafficking through the endosomal pathway or compromised cargo turnover within lysosomes can affect the production, secretion, and content of exosomes. Conversely, exosome biogenesis can affect the endosomal–lysosomal system. Indeed, we propose that efficient exosome release helps to modulate flux through the neuronal endosomal pathway by decompressing potential “traffic jams.” Exosome secretion may have the added benefit of unburdening the neuron’s lysosomal system by delivering endosomal–lysosomal material into the extracellular space, where other cell types may contribute to the degradation of neuronal debris. Thus, maintaining robust neuronal exosome production may prevent or mitigate endosomal and lysosomal abnormalities linked to aging and neurodegenerative diseases. While the current evidence suggests that the exosomal system in the brain can be modulated both by membrane lipid composition and the expression of key proteins that contribute to the formation and secretion of exosomes, how exosomal pathway-regulatory elements sense and respond to perturbations in the endosomal pathway is not well understood. Based upon findings from the extensively studied DS and APOE4 models, we propose that enhanced neuronal exosome secretion can be a protective response, reducing pathological disruption of the endosomal–lysosomal system in disease-vulnerable neurons. Developing therapeutic approaches that help to maintain or enhance neuronal exosome biogenesis and release may be beneficial in a range of disorders of the central nervous system.
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Affiliation(s)
- Paul M Mathews
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States.,Department of Psychiatry, New York University Langone Health, New York, NY, United States.,NYU Neuroscience Institute, New York University Langone Health, New York, NY, United States
| | - Efrat Levy
- Center for Dementia Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States.,Department of Psychiatry, New York University Langone Health, New York, NY, United States.,NYU Neuroscience Institute, New York University Langone Health, New York, NY, United States.,Department of Biochemistry and Molecular Pharmacology, New York University Langone Health, New York, NY, United States
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31
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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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32
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Apolipoprotein E and Alzheimer disease: pathobiology and targeting strategies. Nat Rev Neurol 2019; 15:501-518. [PMID: 31367008 DOI: 10.1038/s41582-019-0228-7] [Citation(s) in RCA: 697] [Impact Index Per Article: 139.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2019] [Indexed: 02/06/2023]
Abstract
Polymorphism in the apolipoprotein E (APOE) gene is a major genetic risk determinant of late-onset Alzheimer disease (AD), with the APOE*ε4 allele conferring an increased risk and the APOE*ε2 allele conferring a decreased risk relative to the common APOE*ε3 allele. Strong evidence from clinical and basic research suggests that a major pathway by which APOE4 increases the risk of AD is by driving earlier and more abundant amyloid pathology in the brains of APOE*ε4 carriers. The number of amyloid-β (Aβ)-dependent and Aβ-independent pathways that are known to be differentially modulated by APOE isoforms is increasing. For example, evidence is accumulating that APOE influences tau pathology, tau-mediated neurodegeneration and microglial responses to AD-related pathologies. In addition, APOE4 is either pathogenic or shows reduced efficiency in multiple brain homeostatic pathways, including lipid transport, synaptic integrity and plasticity, glucose metabolism and cerebrovascular function. Here, we review the recent progress in clinical and basic research into the role of APOE in AD pathogenesis. We also discuss how APOE can be targeted for AD therapy using a precision medicine approach.
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33
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Segatto M, Tonini C, Pfrieger FW, Trezza V, Pallottini V. Loss of Mevalonate/Cholesterol Homeostasis in the Brain: A Focus on Autism Spectrum Disorder and Rett Syndrome. Int J Mol Sci 2019; 20:ijms20133317. [PMID: 31284522 PMCID: PMC6651320 DOI: 10.3390/ijms20133317] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/03/2019] [Accepted: 07/04/2019] [Indexed: 12/27/2022] Open
Abstract
The mevalonate (MVA)/cholesterol pathway is crucial for central nervous system (CNS) development and function and consequently, any dysfunction of this fundamental metabolic pathway is likely to provoke pathologic changes in the brain. Mutations in genes directly involved in MVA/cholesterol metabolism cause a range of diseases, many of which present neurologic and psychiatric symptoms. This raises the question whether other diseases presenting similar symptoms are related albeit indirectly to the MVA/cholesterol pathway. Here, we summarized the current literature suggesting links between MVA/cholesterol dysregulation and specific diseases, namely autism spectrum disorder and Rett syndrome.
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Affiliation(s)
- Marco Segatto
- Department of Biosciences and Territory, University of Molise, Contrada Fonte Lappone, 86090 Pesche (IS), Italy
| | - Claudia Tonini
- Department of Science, University Roma Tre, Viale Marconi, 446, 00146 Rome, Italy
| | - Frank W Pfrieger
- Institute of Cellular and Integrative Neurosciences (INCI) CNRS UPR 3212, Université de Strasbourg, 5, rue Blaise Pascal, 67084 Strasbourg Cedex, France
| | - Viviana Trezza
- Department of Science, University Roma Tre, Viale Marconi, 446, 00146 Rome, Italy
| | - Valentina Pallottini
- Department of Science, University Roma Tre, Viale Marconi, 446, 00146 Rome, Italy.
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34
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Tzioras M, Davies C, Newman A, Jackson R, Spires‐Jones T. Invited Review: APOE at the interface of inflammation, neurodegeneration and pathological protein spread in Alzheimer's disease. Neuropathol Appl Neurobiol 2019; 45:327-346. [PMID: 30394574 PMCID: PMC6563457 DOI: 10.1111/nan.12529] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 10/27/2018] [Indexed: 12/13/2022]
Abstract
Despite more than a century of research, the aetiology of sporadic Alzheimer's disease (AD) remains unclear and finding disease modifying treatments for AD presents one of the biggest medical challenges of our time. AD pathology is characterized by deposits of aggregated amyloid beta (Aβ) in amyloid plaques and aggregated tau in neurofibrillary tangles. These aggregates begin in distinct brain regions and spread throughout the brain in stereotypical patterns. Neurodegeneration, comprising loss of synapses and neurons, occurs in brain regions with high tangle pathology, and an inflammatory response of glial cells appears in brain regions with pathological aggregates. Inheriting an apolipoprotein E ε4 (APOE4) allele strongly increases the risk of developing AD for reasons that are not yet entirely clear. Substantial amounts of evidence support a role for APOE in modulating the aggregation and clearance of Aβ, and data have been accumulating recently implicating APOE4 in exacerbating neurodegeneration, tau pathology and inflammation. We hypothesize that APOE4 influences all the pathological hallmarks of AD and may sit at the interface between neurodegeneration, inflammation and the spread of pathologies through the brain. Here, we conducted a systematic search of the literature and review evidence supporting a role for APOE4 in neurodegeneration and inflammation. While there is no direct evidence yet for APOE4 influencing the spread of pathology, we postulate that this may be found in future based on the literature reviewed here. In conclusion, this review highlights the importance of understanding the role of APOE in multiple important pathological mechanisms in AD.
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Affiliation(s)
- M. Tzioras
- UK Dementia Research Institute and Centre for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - C. Davies
- UK Dementia Research Institute and Centre for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - A. Newman
- UK Dementia Research Institute and Centre for Discovery Brain SciencesThe University of EdinburghEdinburghUK
| | - R. Jackson
- UK Dementia Research Institute and Centre for Discovery Brain SciencesThe University of EdinburghEdinburghUK
- Massachusetts General Hospital and Harvard Medical SchoolCharlestownMAUSA
| | - T. Spires‐Jones
- UK Dementia Research Institute and Centre for Discovery Brain SciencesThe University of EdinburghEdinburghUK
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35
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Peteri UK, Niukkanen M, Castrén ML. Astrocytes in Neuropathologies Affecting the Frontal Cortex. Front Cell Neurosci 2019; 13:44. [PMID: 30809131 PMCID: PMC6379461 DOI: 10.3389/fncel.2019.00044] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/28/2019] [Indexed: 01/15/2023] Open
Abstract
To an increasing extent, astrocytes are connected with various neuropathologies. Astrocytes comprise of a heterogeneous population of cells with region- and species-specific properties. The frontal cortex exhibits high levels of plasticity that is required for high cognitive functions and memory making this region especially susceptible to damage. Aberrations in the frontal cortex are involved with several cognitive disorders, including Alzheimer’s disease, Huntington’s disease and frontotemporal dementia. Human induced pluripotent stem cells (iPSCs) provide an alternative for disease modeling and offer possibilities for studies to investigate pathological mechanisms in a cell type-specific manner. Patient-specific iPSC-derived astrocytes have been shown to recapitulate several disease phenotypes. Addressing astrocyte heterogeneity may provide an improved understanding of the mechanisms underlying neurodegenerative diseases.
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Affiliation(s)
- Ulla-Kaisa Peteri
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mikael Niukkanen
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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36
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Association of cerebrospinal fluid Neurogranin with Alzheimer's disease. Aging Clin Exp Res 2019; 31:185-191. [PMID: 29667155 DOI: 10.1007/s40520-018-0948-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/07/2018] [Indexed: 01/07/2023]
Abstract
Cerebrospinal fluid (CSF) Neurogranin has recently been proposed as a potential biomarker for cognitive decline and brain injury in Alzheimer's disease (AD). To test whether CSF Neurogranin levels are increased in AD and its association with cognitive decline, we examined 99 cognitively normal (CN) subjects, 171 patients with mild cognitive impairment (MCI), and 81 patients with AD in the cross-sectional study from the Alzheimer's Disease Neuroimaging Initiative (ADNI). The results showed that CSF Neurogranin was increased in both AD and MCI compared with controls. CSF Neurogranin was particularly high in patients with MCI and AD dementia with Aβ pathologic features. Neurogranin levels were significantly higher in females compared to males with MCI. Levels of Neurogranin between the males and females with AD and CN did not differ. Neurogranin levels were significantly higher in APOE ε4 carriers compared to APOE ε4 non-carriers with MCI. Levels of Neurogranin between the APOE ε4 carriers and APOE ε4 non-carriers with AD and CN did not differ. Elevated CSF Neurogranin levels were positively correlated with levels of total tau and P-tau in AD. The results indicated that CSF Neurogranin was increased at the prodromal stage of AD and might reflect synaptic injury as cognitive decline in AD.
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37
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Bos MM, Noordam R, Blauw GJ, Slagboom PE, Rensen PCN, van Heemst D. The ApoE ε4 Isoform: Can the Risk of Diseases be Reduced by Environmental Factors? J Gerontol A Biol Sci Med Sci 2018; 74:99-107. [DOI: 10.1093/gerona/gly226] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Maxime M Bos
- Department of Internal Medicine, Section of Gerontology and Geriatrics, the Netherlands
| | - Raymond Noordam
- Department of Internal Medicine, Section of Gerontology and Geriatrics, the Netherlands
| | - Gerard J Blauw
- Department of Internal Medicine, Section of Gerontology and Geriatrics, the Netherlands
| | - P Eline Slagboom
- Department of Medical Statistics and Bioinformatics, Section of Molecular Epidemiology, the Netherlands
| | - Patrick C N Rensen
- Department of Medicine, Division of Endocrinology, the Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, the Netherlands
| | - Diana van Heemst
- Department of Internal Medicine, Section of Gerontology and Geriatrics, the Netherlands
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38
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Koizumi K, Hattori Y, Ahn SJ, Buendia I, Ciacciarelli A, Uekawa K, Wang G, Hiller A, Zhao L, Voss HU, Paul SM, Schaffer C, Park L, Iadecola C. Apoε4 disrupts neurovascular regulation and undermines white matter integrity and cognitive function. Nat Commun 2018; 9:3816. [PMID: 30232327 PMCID: PMC6145902 DOI: 10.1038/s41467-018-06301-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/14/2018] [Indexed: 12/12/2022] Open
Abstract
The ApoE4 allele is associated with increased risk of small vessel disease, which is a cause of vascular cognitive impairment. Here, we report that mice with targeted replacement (TR) of the ApoE gene with human ApoE4 have reduced neocortical cerebral blood flow compared to ApoE3-TR mice, an effect due to reduced vascular density rather than slowing of microvascular red blood cell flow. Furthermore, homeostatic mechanisms matching local delivery of blood flow to brain activity are impaired in ApoE4-TR mice. In a model of cerebral hypoperfusion, these cerebrovascular alterations exacerbate damage to the white matter of the corpus callosum and worsen cognitive dysfunction. Using 3-photon microscopy we found that the increased white matter damage is linked to an enhanced reduction of microvascular flow resulting in local hypoxia. Such alterations may be responsible for the increased susceptibility to hypoxic-ischemic lesions in the subcortical white matter of individuals carrying the ApoE4 allele. ApoE4 is a risk factor for small vessel disease, which can lead to cognitive impairment. Here the authors assess the microvasculature of the corpus callosum using 3-photon microscopy and find that mice expressing the ApoE4 allele are more susceptible than wild-type to white matter injury and cognitive impairment in a model of hypoperfusion-induced hypoxia.
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Affiliation(s)
- Kenzo Koizumi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Yorito Hattori
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Sung Ji Ahn
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Izaskun Buendia
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Antonio Ciacciarelli
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Ken Uekawa
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Gang Wang
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Abigail Hiller
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Lingzhi Zhao
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Henning U Voss
- Department of Radiology, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Steven M Paul
- Department of Neurology and Psychiatry, Washington University in St. Louis, St. Louis, 63110, MO, USA
| | - Chris Schaffer
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA.,Meinig School of Biomedical Engineering, Cornell University, Ithaca, 14853, NY, USA
| | - Laibaik Park
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA.
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10065, NY, USA.
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Wang S, Zhang J, Pan T. APOE ε4 is associated with higher levels of CSF SNAP-25 in prodromal Alzheimer's disease. Neurosci Lett 2018; 685:109-113. [PMID: 30144541 DOI: 10.1016/j.neulet.2018.08.029] [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] [Received: 05/24/2018] [Revised: 08/17/2018] [Accepted: 08/21/2018] [Indexed: 01/12/2023]
Abstract
The underlying mechanism of apolipoprotein E ε4 (APOE ε4) in the pathogenesis of Alzheimer's disease (AD) remains elusive. We hypothesize that synaptic function is differentially affected by APOE isoforms. Levels of CSF SNAP-25 were compared between APOE ε4 carriers and noncarriers in 55 participants with normal cognition, 75 patients with mild cognitive impairment (MCI), and 16 patients with mild AD dementia. We investigated relationships between SNAP-25 levels and age, gender, education, CSF Aβ42, and tau protein. We found that levels of SNAP-25 in CSF were substantially greater in APOE ε4 carriers compared to noncarriers with MCI. There was no significant difference in SNAP-25 levels between APOE ε4 carriers and noncarriers with normal cognition or AD. CSF SNAP-25 levels were associated with MMSE and CSF Aβ and tau levels. In summary, APOE ε4 may affect CSF SNAP levels in MCI patients, suggesting an important role of APOE ε4 in synaptic dysfunction leading to AD.
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Affiliation(s)
- Shanshan Wang
- Department of Neurology, Taizhou Hospital, Wenzhou Medical University, Zhejiang, China
| | - Jie Zhang
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.
| | - Tengwei Pan
- Department of Neurology, Taizhou Hospital, Wenzhou Medical University, Zhejiang, China.
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Oveisgharan S, Buchman AS, Yu L, Farfel J, Hachinski V, Gaiteri C, De Jager PL, Schneider JA, Bennett DA. APOE ε2ε4 genotype, incident AD and MCI, cognitive decline, and AD pathology in older adults. Neurology 2018; 90:e2127-e2134. [PMID: 29752306 PMCID: PMC5996834 DOI: 10.1212/wnl.0000000000005677] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/26/2018] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To examine the association of the APOE ε2ε4 genotype with incident Alzheimer disease (AD), mild cognitive impairment (MCI), cognitive decline, and AD pathology in older adults. METHODS We used data from 2,151 older adults of European ancestry who were free of dementia at baseline and underwent structured annual clinical evaluation in a longitudinal study for incident AD and MCI, and cognitive decline. Postmortem examination in decedents documented pathologic AD and quantified β-amyloid and neurofibrillary tangles. Participants were stratified into 4 groups based on APOE genotyping: ε2ε4, ε4 (ε4ε4, ε4ε3), ε2 (ε2ε2, ε2ε3), with ε3ε3 carriers serving as the reference group. We used Cox proportional hazards models to examine the association of APOE genotype with incident AD and MCI. Linear mixed-effect models were used to examine the association with cognitive decline. Logistic and linear regression models were used to examine AD pathology. All the models controlled for age, sex, and education. RESULTS Of the 2,151 participants included in this study, ε2ε4 accounted for 2.1%, ε3/4 and 4/4 21.8%, ε2/3 and 2/2 14.0%, and ε3ε3 62.1%. We did not observe a difference in the risk of AD for ε2ε4 compared to ε3ε3. In cases without cognitive impairment at baseline, ε2ε4 carriers had an increased risk of incident MCI (hazard ratio 2.13, 95% confidence interval 1.34-3.39, p = 0.002) and a faster rate of cognitive decline (estimate -0.047, SE 0.018, p = 0.008) compared to ε3ε3 carriers. In decedents (n = 1,100), ε2ε4 showed a 3-fold increased odds of pathologic AD and a higher β-amyloid load than ε3ε3. CONCLUSION APOE ε2ε4 genotype in older adults is associated with risk of MCI, cognitive decline, and a greater burden of AD pathology, especially β-amyloid.
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Affiliation(s)
- Shahram Oveisgharan
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY.
| | - Aron S Buchman
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Lei Yu
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Jose Farfel
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Vladimir Hachinski
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Chris Gaiteri
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Philip L De Jager
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - Julie A Schneider
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
| | - David A Bennett
- From Rush Alzheimer's Disease Center (S.O., A.S.B., L.Y., J.F., C.G., J.A.S., D.A.B.) and Departments of Neurological Sciences (A.S.B., L.Y., J.A.S., D.A.B.) and Pathology (J.F., J.A.S.), Rush University Medical Center, Chicago, IL; Shariati Hospital (S.O.), Tehran University of Medical Sciences, Iran; Department of Geriatrics (J.F.), University of Sao Paulo Medical School, Brazil; University Hospital (V.H.), University of Western Ontario, London, Canada; Broad Institute (P.L.D.J.), Cambridge, MA; Center for Translational & Systems Neuroimmunology (P.L.D.J.), Department of Neurology, Columbia University Medical Center, New York, NY
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Zhao N, Liu CC, Qiao W, Bu G. Apolipoprotein E, Receptors, and Modulation of Alzheimer's Disease. Biol Psychiatry 2018; 83:347-357. [PMID: 28434655 PMCID: PMC5599322 DOI: 10.1016/j.biopsych.2017.03.003] [Citation(s) in RCA: 243] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 12/31/2022]
Abstract
Apolipoprotein E (apoE) is a lipid carrier in both the peripheral and the central nervous systems. Lipid-loaded apoE lipoprotein particles bind to several cell surface receptors to support membrane homeostasis and injury repair in the brain. Considering prevalence and relative risk magnitude, the ε4 allele of the APOE gene is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). ApoE4 contributes to AD pathogenesis by modulating multiple pathways, including but not limited to the metabolism, aggregation, and toxicity of amyloid-β peptide, tauopathy, synaptic plasticity, lipid transport, glucose metabolism, mitochondrial function, vascular integrity, and neuroinflammation. Emerging knowledge on apoE-related pathways in the pathophysiology of AD presents new opportunities for AD therapy. We describe the biochemical and biological features of apoE and apoE receptors in the central nervous system. We also discuss the evidence and mechanisms addressing differential effects of apoE isoforms and the role of apoE receptors in AD pathogenesis, with a particular emphasis on the clinical and preclinical studies related to amyloid-β pathology. Finally, we summarize the current strategies of AD therapy targeting apoE, and postulate that effective strategies require an apoE isoform-specific approach.
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Affiliation(s)
- Na Zhao
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Wenhui Qiao
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian, China.
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Di Battista AM, Heinsinger NM, Rebeck GW. Alzheimer's Disease Genetic Risk Factor APOE-ε4 Also Affects Normal Brain Function. Curr Alzheimer Res 2017; 13:1200-1207. [PMID: 27033053 DOI: 10.2174/1567205013666160401115127] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 03/15/2016] [Accepted: 03/28/2016] [Indexed: 12/24/2022]
Abstract
APOE-ε4 is the strongest genetic risk factor for Alzheimer's disease (AD), and is associated with an increase in the levels of amyloid deposition and an early age of onset. Recent data demonstrate that AD pathological changes occur decades before clinical symptoms, raising questions about the precise onset of the disease. Now a convergence of approaches in mice and humans has demonstrated that APOE-ε4 affects normal brain function even very early in life in the absence of gross AD pathological changes. Normal mice expressing APOE4 have task-specific spatial learning deficits, as well as reduced NMDAR-dependent signaling and structural changes to presynaptic and postsynaptic compartments in neurons, particularly in hippocampal regions. Young humans possessing APOE-ε4 are more adept than APOE-ε4 negative individuals at some behavioral tasks, and functional magnetic resonance imaging has shown that inheritance of APOE-ε4 has specific effects on medial temporal brain activities. These findings suggest that inheritance of APOE-ε4 causes life long changes to the brain that may be related to the late risk of AD. Several possible mechanisms of how APOE-ε4 could affect brain neurochemistry, structure, and function are reviewed.
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Affiliation(s)
| | | | - G William Rebeck
- New Research Building, WP- 13, 3970 Reservoir Rd, NW, Washington, DC 20007; USA
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ApoE4-associated phospholipid dysregulation contributes to development of Tau hyper-phosphorylation after traumatic brain injury. Sci Rep 2017; 7:11372. [PMID: 28900205 PMCID: PMC5595858 DOI: 10.1038/s41598-017-11654-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/25/2017] [Indexed: 12/14/2022] Open
Abstract
The apolipoprotein E4 (ApoE4) genotype combines with traumatic brain injury (TBI) to increase the risk of developing Alzheimer's Disease (AD). However, the underlying mechanism(s) is not well-understood. We found that after exposure to repetitive blast-induced TBI, phosphoinositol biphosphate (PIP2) levels in hippocampal regions of young ApoE3 mice were elevated and associated with reduction in expression of a PIP2 degrading enzyme, synaptojanin 1 (synj1). In contrast, hippocampal PIP2 levels in ApoE4 mice did not increase after blast TBI. Following blast TBI, phospho-Tau (pTau) levels were unchanged in ApoE3 mice, whereas in ApoE4 mice, levels of pTau were significantly increased. To determine the causal relationship between changes in pTau and PIP2/synj1 levels after TBI, we tested if down-regulation of synj1 prevented blast-induced Tau hyper-phosphorylation. Knockdown of synj1 decreased pTau levels in vitro, and abolished blast-induced elevation of pTau in vivo. Blast TBI increased glycogen synthase kinase (GSK)-3β activities in ApoE4 mice, and synj1 knockdown inhibited GSK3β phosphorylation of Tau. Together, these data suggest that ApoE proteins regulate brain phospholipid homeostasis in response to TBI and that the ApoE4 isoform is dysfunctional in this process. Down-regulation of synj1 rescues blast-induced phospholipid dysregulation and prevents development of Tau hyper-phosphorylation in ApoE4 carriers.
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44
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Zhao J, Davis MD, Martens YA, Shinohara M, Graff-Radford NR, Younkin SG, Wszolek ZK, Kanekiyo T, Bu G. APOE ε4/ε4 diminishes neurotrophic function of human iPSC-derived astrocytes. Hum Mol Genet 2017; 26:2690-2700. [PMID: 28444230 PMCID: PMC5886091 DOI: 10.1093/hmg/ddx155] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 03/27/2017] [Accepted: 04/19/2017] [Indexed: 12/22/2022] Open
Abstract
The ε4 allele of the APOE gene encoding apolipoprotein E (apoE) is a strong genetic risk factor for aging-related cognitive decline as well as late-onset Alzheimer's disease (AD) compared to the common ε3 allele. In the central nervous system, apoE is produced primarily by astrocytes and functions in transporting lipids including cholesterol to support neuronal homeostasis and synaptic integrity. Although mouse models and corresponding primary cells have provided valuable tools for studying apoE isoform-dependent functions, recent studies have shown that human astrocytes have a distinct gene expression profile compare with rodent astrocytes. Human induced pluripotent stem cells (iPSCs) derived from individuals carrying specific gene variants or mutations provide an alternative cellular model more relevant to humans upon differentiation into specific cell types. Thus, we reprogramed human skin fibroblasts from cognitively normal individuals carrying APOE ε3/ε3 or ε4/ε4 genotype to iPSC clones and further differentiated them into neural progenitor cells and then astrocytes. We found that human iPSC-derived astrocytes secreted abundant apoE with apoE4 lipoprotein particles less lipidated compared to apoE3 particles. More importantly, human iPSC-derived astrocytes were capable of promoting neuronal survival and synaptogenesis when co-cultured with iPSC-derived neurons with APOE ε4/ε4 astrocytes less effective in supporting these neurotrophic functions than those with APOE ε3/ε3 genotype. Taken together, our findings demonstrate APOE genotype-dependent effects using human iPSC-derived astrocytes and provide novel evidence that the human iPSC-based model system is a strong tool to explore how apoE isoforms contribute to neurodegenerative diseases.
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Sen A, Nelson TJ, Alkon DL. ApoE isoforms differentially regulates cleavage and secretion of BDNF. Mol Brain 2017; 10:19. [PMID: 28569173 PMCID: PMC5452344 DOI: 10.1186/s13041-017-0301-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 05/25/2017] [Indexed: 01/12/2023] Open
Abstract
Apolipoprotein E4 (ApoE4) is a major genetic risk factor for sporadic or late onset Alzheimer’s disease (AD). Brain-derived neurotrophic factor (BDNF) is decreased by 3 to 4-fold in the brains of AD patients at autopsy. ApoE4 mice also have reduced BDNF levels. However, there have been no reports relating the different ApoE isoforms or AD to differential regulation of BDNF. Here we report that in the hippocampal regions of AD patients both prepro-BDNF and pro-BDNF expression showed a 40 and 60% decrease respectively compared to that expression in the hippocampi of age-matched control patients. We further report that ApoE isoforms differentially regulate maturation and secretion of BDNF from primary human astrocytes. After 24 h, ApoE3 treated astrocytes secreted 1.75- fold higher pro-BDNF than ApoE2-treated astrocytes, and ApoE2-treated astrocytes secreted 3-fold more mature-BDNF (m-BDNF) than ApoE3-treated astrocytes. In contrast, ApoE4-treated cells secreted negligible amounts of m-BDNF or pro-BDNF. ApoE2 increased the level of intracellular pre-pro BDNF by 19.04 ± 6.68%, while ApoE4 reduced the pre-pro BDNF by 21.61 ± 5.9% compared to untreated cells. Similar results were also seen in ApoE2, ApoE3 or ApoE4 treated cells at 4 h. Together, these results indicate that an ApoE2 or ApoE3 mediated positive regulation of BDNF may be protective while ApoE4 related defects in BDNF processing could lead to AD pathophysiology. These interactions of the ApoE isoforms with BDNF may help explain the increased risk of AD associated with the ApoE4 isoform.
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Affiliation(s)
- Abhik Sen
- Blanchette Rockefeller Neurosciences Institute, 8 Medical Center Drive, Morgantown, WV, 26505, USA.
| | - Thomas J Nelson
- Blanchette Rockefeller Neurosciences Institute, 8 Medical Center Drive, Morgantown, WV, 26505, USA
| | - Daniel L Alkon
- Blanchette Rockefeller Neurosciences Institute, 8 Medical Center Drive, Morgantown, WV, 26505, USA
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Rebeck GW. The role of APOE on lipid homeostasis and inflammation in normal brains. J Lipid Res 2017; 58:1493-1499. [PMID: 28258087 DOI: 10.1194/jlr.r075408] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/02/2017] [Indexed: 12/24/2022] Open
Abstract
The role of APOE in the risk of Alzheimer's disease (AD) has largely focused on its effects on AD pathological processes. However, there are increasing data that APOE genotype affects processes in normal brains. Studies of young cognitively normal humans show effects of APOE genotype on brain structure and activity. Studies of normal APOE knock-in mice show effects of APOE genotype on brain structure, neuronal markers, and behavior. APOE interactions with molecules important for lipid efflux and lipid endocytosis underlie effects of APOE genotype on neuroinflammation and lipoprotein composition. These effects provide important targets for new therapies for reduction of the risk of AD before any signs of pathogenesis.
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Affiliation(s)
- G William Rebeck
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC.
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Donovan NJ, Okereke OI, Vannini P, Amariglio RE, Rentz DM, Marshall GA, Johnson KA, Sperling RA. Association of Higher Cortical Amyloid Burden With Loneliness in Cognitively Normal Older Adults. JAMA Psychiatry 2016; 73:1230-1237. [PMID: 27806159 PMCID: PMC5257284 DOI: 10.1001/jamapsychiatry.2016.2657] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
IMPORTANCE Emotional and behavioral symptoms in cognitively normal older people may be direct manifestations of Alzheimer disease (AD) pathophysiology at the preclinical stage, prior to the onset of mild cognitive impairment. Loneliness is a perceived state of social and emotional isolation that has been associated with cognitive and functional decline and an increased risk of incident AD dementia. We hypothesized that loneliness might occur in association with elevated cortical amyloid burden, an in vivo research biomarker of AD. OBJECTIVE To determine whether cortical amyloid burden is associated with greater loneliness in cognitively normal older adults. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional analyses using data from the Harvard Aging Brain Study of 79 cognitively normal, community-dwelling participants. A continuous, aggregate measure of cortical amyloid burden, determined by Pittsburgh Compound B-positron emission tomography (PiB-PET), was examined in association with loneliness in linear regression models adjusting for age, sex, apolipoprotein E ε4 (APOEε4), socioeconomic status, depression, anxiety, and social network (without and with the interaction of amyloid and APOEε4). We also quantified the association of high amyloid burden (amyloid-positive group) to loneliness (lonely group) using logistic regression, controlling for the same covariates, with the amyloid-positive group and the lonely group, each composing 32% of the sample (n = 25). MAIN OUTCOMES AND MEASURES Loneliness, as determined by the 3-item UCLA Loneliness Scale (possible range, 3-12, with higher score indicating greater loneliness). RESULTS The 79 participants included 43 women and 36 men with a mean (SD) age of 76.4 (6.2) years. Mean (SD) cortical amyloid burden via PiB-PET was 1.230 (0.209), and the mean (SD) UCLA-3 loneliness score was 5.3 (1.8). Twenty-two (28%) had positive APOEε4 carrier status, and 25 (32%) were in the amyloid-positive group with cortical PiB distribution volume ratio greater than 1.2. Controlling for age, sex, APOEε4, socioeconomic status, depression, anxiety, and social network, we found that higher amyloid burden was significantly associated with greater loneliness: compared with individuals in the amyloid-negative group, those in the amyloid-positive group were 7.5-fold (95% CI, 1.7-fold to 34.0-fold) more likely to be classified as lonely than nonlonely (β = 3.3, partial r = 0.4, P = .002). Furthermore, the association of high amyloid burden and loneliness was stronger in APOEε4 carriers than in noncarriers. CONCLUSIONS AND RELEVANCE We report a novel association of loneliness with cortical amyloid burden in cognitively normal older adults, suggesting that loneliness is a neuropsychiatric symptom relevant to preclinical AD. This work will inform new research into the neural underpinnings and disease mechanisms involved in loneliness and may enhance early detection and intervention research in AD.
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Affiliation(s)
- Nancy J. Donovan
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts3Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts4Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Olivia I. Okereke
- Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Patrizia Vannini
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rebecca E. Amariglio
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Dorene M. Rentz
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts3Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Gad A. Marshall
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Keith A. Johnson
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston6Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Reisa A. Sperling
- Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts2Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts5Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston
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Martin GM. Geroscience: Addressing the mismatch between its exciting research opportunities, its economic imperative and its current funding crisis. Exp Gerontol 2016; 94:46-51. [PMID: 27871822 DOI: 10.1016/j.exger.2016.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 12/11/2022]
Abstract
There is at present a huge disconnect between levels of funding for basic research on fundamental mechanisms of biological aging and, given demographic projections, the anticipated enormous social and economic impacts of a litany of chronic diseases for which aging is by far the major risk factor: One valuable approach, recently instigated by Felipe Sierra & colleagues at the US National Institute on Aging, is the development of a Geroscience Interest Group among virtually all of the NIH institutes. A complementary approach would be to seek major escalations of private funding. The American Federation for Aging Research, the Paul Glenn Foundation and the Ellison Medical Foundation pioneered efforts by the private sector to provide substantial supplements to public sources of funding. It is time for our community to organize efforts towards the enhancements of such crucial contributions, especially in support of the emerging generation of young investigators, many of whom are leaving our ranks to seek alternative employment. To do so, we must provide potential donors with strong economic, humanitarian and scientific rationales. An initial approach to such efforts is briefly outlined in this manuscript as a basis for wider discussions within our community.
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Affiliation(s)
- George M Martin
- Department of Pathology, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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Sun X, Dong C, Levin B, Crocco E, Loewenstein D, Zetterberg H, Blennow K, Wright CB. APOE ε4 carriers may undergo synaptic damage conferring risk of Alzheimer's disease. Alzheimers Dement 2016; 12:1159-1166. [PMID: 27321472 PMCID: PMC5742562 DOI: 10.1016/j.jalz.2016.05.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 04/15/2016] [Accepted: 05/09/2016] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Pathogenesis of Alzheimer's disease (AD) in apolipoprotein E ε4 (APOE ε4) carriers remains unclear. We hypothesize that APOE isoforms have differential effects on synaptic function. METHODS We compared levels of CSF neurogranin (Ng) between APOE ε4 carriers and noncarriers in 399 subjects with normal cognition, mild cognitive impairment (MCI), and AD. We examined associations between Ng levels and age, education, gender, CSF-Aβ42, and tau protein. RESULTS Neurogranin levels were significantly higher in APOE ε4 carriers compared to APOE ε4 noncarriers with MCI. Levels of Ng between the APOE ε4 carriers and APOE ε4 noncarriers with AD did not differ. Ng levels were correlated with MMSE and levels of tau and Aβ42. DISCUSSION Significantly higher CSF Ng levels in APOE ε4 carriers with MCI may reflect synaptic injury underlying early cognitive impairment. Neurogranin may be an early biomarker of AD and important for disease diagnosis and timing of intervention in APOE ε4 carriers.
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Affiliation(s)
- Xiaoyan Sun
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Chuanhui Dong
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Bonnie Levin
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Elizabeth Crocco
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - David Loewenstein
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University Gothenburg, Molndal, Sweden; Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK; Clinical Neurochemistry Laboratory Sahlgrenska University Hospital, Mölndal, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University Gothenburg, Molndal, Sweden; Clinical Neurochemistry Laboratory Sahlgrenska University Hospital, Mölndal, Sweden
| | - Clinton B Wright
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, FL, USA
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Yamazaki Y, Painter MM, Bu G, Kanekiyo T. Apolipoprotein E as a Therapeutic Target in Alzheimer's Disease: A Review of Basic Research and Clinical Evidence. CNS Drugs 2016; 30:773-89. [PMID: 27328687 PMCID: PMC5526196 DOI: 10.1007/s40263-016-0361-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that causes progressive cognitive decline. The majority of AD cases are sporadic and late-onset (>65 years old) making it the leading cause of dementia in the elderly. While both genetic and environmental factors contribute to the development of late-onset AD (LOAD), APOE polymorphism is a major genetic risk determinant for LOAD. In humans, the APOE gene has three major allelic variants: ε2, ε3, and ε4, of which APOE ε4 is the strongest genetic risk factor for LOAD, whereas APOE ε2 is protective. Mounting evidence suggests that APOE ε4 contributes to AD pathogenesis through multiple pathways including facilitated amyloid-β deposition, increased tangle formation, synaptic dysfunction, exacerbated neuroinflammation, and cerebrovascular defects. Since APOE modulates multiple biological processes through its corresponding protein apolipoprotein E (apoE), APOE gene and apoE properties have been a promising target for therapy and drug development against AD. In this review, we summarize the current evidence regarding how the APOE ε4 allele contributes to the pathogenesis of AD and how relevant therapeutic approaches can be developed to target apoE-mediated pathways in AD.
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Affiliation(s)
- Yu Yamazaki
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Meghan M Painter
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Takahisa Kanekiyo
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
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