1
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Moon HJ, Luo Y, Chugh D, Zhao L. Human apolipoprotein E glycosylation and sialylation: from structure to function. Front Mol Neurosci 2024; 17:1399965. [PMID: 39169951 PMCID: PMC11335735 DOI: 10.3389/fnmol.2024.1399965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 06/28/2024] [Indexed: 08/23/2024] Open
Abstract
Human apolipoprotein E (ApoE) was first identified as a polymorphic gene in the 1970s; however, the genetic association of ApoE genotypes with late-onset sporadic Alzheimer's disease (sAD) was only discovered 20 years later. Since then, intensive research has been undertaken to understand the molecular effects of ApoE in the development of sAD. Despite three decades' worth of effort and over 10,000 papers published, the greatest mystery in the ApoE field remains: human ApoE isoforms differ by only one or two amino acid residues; what is responsible for their significantly distinct roles in the etiology of sAD, with ApoE4 conferring the greatest genetic risk for sAD whereas ApoE2 providing exceptional neuroprotection against sAD. Emerging research starts to point to a novel and compelling hypothesis that the sialoglycans posttranslationally appended to human ApoE may serve as a critical structural modifier that alters the biology of ApoE, leading to the opposing impacts of ApoE isoforms on sAD and likely in the peripheral systems as well. ApoE has been shown to be posttranslationally glycosylated in a species-, tissue-, and cell-specific manner. Human ApoE, particularly in brain tissue and cerebrospinal fluid (CSF), is highly glycosylated, and the glycan chains are exclusively attached via an O-linkage to serine or threonine residues. Moreover, studies have indicated that human ApoE glycans undergo sialic acid modification or sialylation, a structural alteration found to be more prominent in ApoE derived from the brain and CSF than plasma. However, whether the sialylation modification of human ApoE has a biological role is largely unexplored. Our group recently first reported that the three major isoforms of human ApoE in the brain undergo varying degrees of sialylation, with ApoE2 exhibiting the most abundant sialic acid modification, whereas ApoE4 is the least sialylated. Our findings further indicate that the sialic acid moiety on human ApoE glycans may serve as a critical modulator of the interaction of ApoE with amyloid β (Aβ) and downstream Aβ pathogenesis, a prominent pathologic feature in AD. In this review, we seek to provide a comprehensive summary of this exciting and rapidly evolving area of ApoE research, including the current state of knowledge and opportunities for future exploration.
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Affiliation(s)
- Hee-Jung Moon
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Yan Luo
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Diksha Chugh
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Liqin Zhao
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, United States
- Neuroscience Graduate Program, University of Kansas, Lawrence, KS, United States
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2
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Aceves M, Granados J, Leandro AC, Peralta J, Glahn DC, Williams-Blangero S, Curran JE, Blangero J, Kumar S. Role of Neurocellular Endoplasmic Reticulum Stress Response in Alzheimer's Disease and Related Dementias Risk. Genes (Basel) 2024; 15:569. [PMID: 38790197 PMCID: PMC11121587 DOI: 10.3390/genes15050569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
Currently, more than 55 million people around the world suffer from dementia, and Alzheimer's Disease and Related Dementias (ADRD) accounts for nearly 60-70% of all those cases. The spread of Alzheimer's Disease (AD) pathology and progressive neurodegeneration in the hippocampus and cerebral cortex is strongly correlated with cognitive decline in AD patients; however, the molecular underpinning of ADRD's causality is still unclear. Studies of postmortem AD brains and animal models of AD suggest that elevated endoplasmic reticulum (ER) stress may have a role in ADRD pathology through altered neurocellular homeostasis in brain regions associated with learning and memory. To study the ER stress-associated neurocellular response and its effects on neurocellular homeostasis and neurogenesis, we modeled an ER stress challenge using thapsigargin (TG), a specific inhibitor of sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), in the induced pluripotent stem cell (iPSC)-derived neural stem cells (NSCs) of two individuals from our Mexican American Family Study (MAFS). High-content screening and transcriptomic analysis of the control and ER stress-challenged NSCs showed that the NSCs' ER stress response resulted in a significant decline in NSC self-renewal and an increase in apoptosis and cellular oxidative stress. A total of 2300 genes were significantly (moderated t statistics FDR-corrected p-value ≤ 0.05 and fold change absolute ≥ 2.0) differentially expressed (DE). The pathway enrichment and gene network analysis of DE genes suggests that all three unfolded protein response (UPR) pathways, protein kinase RNA-like ER kinase (PERK), activating transcription factor-6 (ATF-6), and inositol-requiring enzyme-1 (IRE1), were significantly activated and cooperatively regulated the NSCs' transcriptional response to ER stress. Our results show that IRE1/X-box binding protein 1 (XBP1) mediated transcriptional regulation of the E2F transcription factor 1 (E2F1) gene, and its downstream targets have a dominant role in inducing G1/S-phase cell cycle arrest in ER stress-challenged NSCs. The ER stress-challenged NSCs also showed the activation of C/EBP homologous protein (CHOP)-mediated apoptosis and the dysregulation of synaptic plasticity and neurotransmitter homeostasis-associated genes. Overall, our results suggest that the ER stress-associated attenuation of NSC self-renewal, increased apoptosis, and dysregulated synaptic plasticity and neurotransmitter homeostasis plausibly play a role in the causation of ADRD.
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Affiliation(s)
- Miriam Aceves
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, McAllen, TX 78504, USA; (M.A.); (J.G.)
| | - Jose Granados
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, McAllen, TX 78504, USA; (M.A.); (J.G.)
| | - Ana C. Leandro
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78520, USA; (A.C.L.); (J.P.); (S.W.-B.); (J.E.C.); (J.B.)
| | - Juan Peralta
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78520, USA; (A.C.L.); (J.P.); (S.W.-B.); (J.E.C.); (J.B.)
| | - David C. Glahn
- Department of Psychiatry, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA;
| | - Sarah Williams-Blangero
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78520, USA; (A.C.L.); (J.P.); (S.W.-B.); (J.E.C.); (J.B.)
| | - Joanne E. Curran
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78520, USA; (A.C.L.); (J.P.); (S.W.-B.); (J.E.C.); (J.B.)
| | - John Blangero
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78520, USA; (A.C.L.); (J.P.); (S.W.-B.); (J.E.C.); (J.B.)
| | - Satish Kumar
- Division of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, McAllen, TX 78504, USA; (M.A.); (J.G.)
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3
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Mhatre-Winters I, Eid A, Han Y, Tieu K, Richardson JR. Sex and APOE Genotype Alter the Basal and Induced Inflammatory States of Primary Astrocytes from Humanized Targeted Replacement Mice. ASN Neuro 2023; 15:17590914221144549. [PMID: 36604975 PMCID: PMC9982390 DOI: 10.1177/17590914221144549] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Apolipoprotein E4 (APOE4) genotype and sex are significant risk factors for Alzheimer's disease (AD), with females demonstrating increased risk modulated by APOE genotype. APOE is predominantly expressed in astrocytes, however, there is a lack of comprehensive assessments of sex differences in astrocytes stratified by APOE genotype. Here, we examined the response of mixed-sex and sex-specific neonatal APOE3 and APOE4 primary mouse astrocytes (PMA) to a cytokine mix of IL1b, TNFa, and IFNg. Pro-inflammatory and anti-inflammatory cytokine profiles were assessed by qRT-PCR and Meso Scale Discovery multiplex assay. Mixed-sex APOE4 PMA were found to have higher basal messenger RNA expression of several pro-inflammatory cytokines including Il6, Tnfa, Il1b, Mcp1, Mip1a, and Nos2 compared to APOE3 PMA, which was accompanied by increased levels of these secreted cytokines. In sex-specific cultures, basal expression of Il1b, Il6, and Nos2 was 1.5 to 2.5 fold higher in APOE4 female PMA compared to APOE4 males, with both being higher than APOE3 PMA. Similar results were found for secreted levels of these cytokines. Together, these findings indicate that APOE4 genotype and female sex, contribute to a greater inflammatory response in primary astrocytes and these data may provide a framework for investigating the mechanisms contributing to genotype and sex differences in AD-related neuroinflammation.
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Affiliation(s)
- Isha Mhatre-Winters
- Department of Environmental Health Sciences, Robert Stempel College
of Public Health and Social Work, Florida International
University, Miami, FL, USA,Department of Neurosciences, School of Biomedical Sciences, Kent
State University, Kent, OH, USA
| | - Aseel Eid
- Department of Environmental Health Sciences, Robert Stempel College
of Public Health and Social Work, Florida International
University, Miami, FL, USA
| | - Yoonhee Han
- Department of Environmental Health Sciences, Robert Stempel College
of Public Health and Social Work, Florida International
University, Miami, FL, USA
| | - Kim Tieu
- Department of Environmental Health Sciences, Robert Stempel College
of Public Health and Social Work, Florida International
University, Miami, FL, USA
| | - Jason R. Richardson
- Department of Environmental Health Sciences, Robert Stempel College
of Public Health and Social Work, Florida International
University, Miami, FL, USA,Jason R. Richardson, Department of
Environmental Health Sciences, Robert Stempel College of Public Health and
Social Work, Florida International University, Miami, FL 33199-2156, USA.
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4
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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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5
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Apolipoprotein E in Cardiometabolic and Neurological Health and Diseases. Int J Mol Sci 2022; 23:ijms23179892. [PMID: 36077289 PMCID: PMC9456500 DOI: 10.3390/ijms23179892] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/25/2022] [Accepted: 08/28/2022] [Indexed: 11/17/2022] Open
Abstract
A preponderance of evidence obtained from genetically modified mice and human population studies reveals the association of apolipoprotein E (apoE) deficiency and polymorphisms with pathogenesis of numerous chronic diseases, including atherosclerosis, obesity/diabetes, and Alzheimer’s disease. The human APOE gene is polymorphic with three major alleles, ε2, ε3 and ε4, encoding apoE2, apoE3, and apoE4, respectively. The APOE gene is expressed in many cell types, including hepatocytes, adipocytes, immune cells of the myeloid lineage, vascular smooth muscle cells, and in the brain. ApoE is present in subclasses of plasma lipoproteins, and it mediates the clearance of atherogenic lipoproteins from plasma circulation via its interaction with LDL receptor family proteins and heparan sulfate proteoglycans. Extracellular apoE also interacts with cell surface receptors and confers signaling events for cell regulation, while apoE expressed endogenously in various cell types regulates cell functions via autocrine and paracrine mechanisms. This review article focuses on lipoprotein transport-dependent and -independent mechanisms by which apoE deficiency or polymorphisms contribute to cardiovascular disease, metabolic disease, and neurological disorders.
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6
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Sex and APOE Genotype Alter the Basal and Induced Inflammatory States of Primary Microglia from APOE Targeted Replacement Mice. Int J Mol Sci 2022; 23:ijms23179829. [PMID: 36077227 PMCID: PMC9456163 DOI: 10.3390/ijms23179829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 11/16/2022] Open
Abstract
The sex and APOE4 genotype are significant risk factors for Alzheimer’s disease (AD); however, the mechanism(s) responsible for this interaction are still a matter of debate. Here, we assess the responses of mixed-sex and sex-specific APOE3 and APOE4 primary microglia (PMG) to lipopolysaccharide and interferon-gamma. In our investigation, inflammatory cytokine profiles were assessed by qPCR and multiplex ELISA assays. Mixed-sex APOE4 PMG exhibited higher basal mRNA expression and secreted levels of TNFa and IL1b. In sex-specific cultures, basal expression and secreted levels of IL1b, TNFa, IL6, and NOS2 were 2−3 fold higher in APOE4 female PMG compared to APOE4 males, with both higher than APOE3 cells. Following an inflammatory stimulus, the expression of pro-inflammatory cytokines and the secreted cytokine level were upregulated in the order E4 female > E4 male > E3 female > E3 male in sex-specific cultures. These data indicate that the APOE4 genotype and female sex together contribute to a greater inflammatory response in PMG isolated from targeted replacement humanized APOE mice. These data are consistent with clinical data and indicate that sex-specific PMG may provide a platform for exploring mechanisms of genotype and sex differences in AD related to neuroinflammation and neurodegeneration.
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7
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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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8
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Bancroft EA, Srinivasan R. Emerging Roles for Aberrant Astrocytic Calcium Signals in Parkinson's Disease. Front Physiol 2022; 12:812212. [PMID: 35087422 PMCID: PMC8787054 DOI: 10.3389/fphys.2021.812212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/09/2021] [Indexed: 11/25/2022] Open
Abstract
Astrocytes display a plethora of spontaneous Ca2+ signals that modulate vital functions of the central nervous system (CNS). This suggests that astrocytic Ca2+ signals also contribute to pathological processes in the CNS. In this context, the molecular mechanisms by which aberrant astrocytic Ca2+ signals trigger dopaminergic neuron loss during Parkinson's disease (PD) are only beginning to emerge. Here, we provide an evidence-based perspective on potential mechanisms by which aberrant astrocytic Ca2+ signals can trigger dysfunction in three distinct compartments of the brain, viz., neurons, microglia, and the blood brain barrier, thereby leading to PD. We envision that the coming decades will unravel novel mechanisms by which aberrant astrocytic Ca2+ signals contribute to PD and other neurodegenerative processes in the CNS.
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Affiliation(s)
- Eric A. Bancroft
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University College of Medicine, Bryan, TX, United States
| | - Rahul Srinivasan
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University College of Medicine, Bryan, TX, United States
- Texas A&M Institute for Neuroscience (TAMIN), College Station, TX, United States
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9
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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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10
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Ammal Kaidery N, Ahuja M, Sharma SM, Thomas B. An Emerging Role of miRNAs in Neurodegenerative Diseases: Mechanisms and Perspectives on miR146a. Antioxid Redox Signal 2021; 35:580-594. [PMID: 33403895 PMCID: PMC8388248 DOI: 10.1089/ars.2020.8256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Significance: Advancements in and access to health care have led to unprecedented improvements in the quality of life and increased lifespan of human beings in the past century. However, aging is a significant risk factor for neurodegenerative diseases (NDs). Hence, improved life expectancy has led to an increased incidence of NDs. Despite intense research, effective treatments for NDs remain elusive. The future of neurotherapeutics development depends on effective disease modification strategies centered on carefully scrutinized targets. Recent Advances: As a promising new direction, recent evidence has demonstrated that epigenetic processes modify diverse biochemical pathways, including those related to NDs. Small non-coding RNAs, known as microRNAs (miRNAs), are components of the epigenetic system that alter the expression of target genes at the post-transcriptional level. Critical Issues: miRNAs are expressed abundantly in the central nervous system and are critical for the normal functioning and survival of neurons. Here, we review recent advances in elucidating miRNAs' roles in NDs and discuss their potential as therapeutic targets. In particular, neuroinflammation is a major pathological hallmark of NDs and miR146a is a crucial regulator of inflammation. Future Directions: Finally, we explore the possibilities of developing miR146a as a potential biomarker and therapeutic target where additional research may help facilitate the detection and amelioration of neuroinflammation in NDs. Antioxid. Redox Signal. 35, 580-594.
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Affiliation(s)
- Navneet Ammal Kaidery
- Darby Children's Research Institute, Departments of Medical University of South Carolina, Charleston, South Carolina, USA.,Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Manuj Ahuja
- Darby Children's Research Institute, Departments of Medical University of South Carolina, Charleston, South Carolina, USA.,Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sudarshana M Sharma
- Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, and Departments of Medical University of South Carolina, Charleston, South Carolina, USA
| | - Bobby Thomas
- Darby Children's Research Institute, Departments of Medical University of South Carolina, Charleston, South Carolina, USA.,Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA.,Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA.,Drug Discovery, Medical University of South Carolina, Charleston, South Carolina, USA
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11
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Igel E, Haller A, Wolfkiel PR, Orr-Asman M, Jaeschke A, Hui DY. Distinct pro-inflammatory properties of myeloid cell-derived apolipoprotein E2 and E4 in atherosclerosis promotion. J Biol Chem 2021; 297:101106. [PMID: 34425108 PMCID: PMC8437825 DOI: 10.1016/j.jbc.2021.101106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 11/25/2022] Open
Abstract
Polymorphisms in the apolipoprotein E (apoE) gene are risk factors for chronic inflammatory diseases including atherosclerosis. The gene product apoE is synthesized in many cell types and has both lipid transport–dependent and lipid transport–independent functions. Previous studies have shown that apoE expression in myeloid cells protects against atherogenesis in hypercholesterolemic ApoE−/− mice. However, the mechanism of this protection is still unclear. Using human APOE gene replacement mice as models, this study showed that apoE2 and apoE4 expressed endogenously in myeloid cells enhanced the inflammatory response via mechanisms independent of plasma lipoprotein transport. The data revealed that apoE2-expressing myeloid cells contained higher intracellular cholesterol levels because of impaired efflux, causing increasing inflammasome activation and myelopoiesis. In contrast, intracellular cholesterol levels were not elevated in apoE4-expressing myeloid cells, and its proinflammatory property was found to be independent of inflammasome signaling and related to enhanced oxidative stress. When ApoE−/− mice were reconstituted with bone marrow from various human APOE gene replacement mice, effective reduction of atherosclerosis was observed with marrow cells obtained from APOE3 but not APOE2 and APOE4 gene replacement mice. Taken together, these results documented that apoE2 and apoE4 expression in myeloid cells promotes inflammation via distinct mechanisms and promotes atherosclerosis in a plasma lipoprotein transport–independent manner.
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Affiliation(s)
- Emily Igel
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - April Haller
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Patrick R Wolfkiel
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Melissa Orr-Asman
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Anja Jaeschke
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - David Y Hui
- Department of Pathology and Laboratory Medicine, Metabolic Diseases Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
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12
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Saunders AM, Burns DK, Gottschalk WK. Reassessment of Pioglitazone for Alzheimer's Disease. Front Neurosci 2021; 15:666958. [PMID: 34220427 PMCID: PMC8243371 DOI: 10.3389/fnins.2021.666958] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/18/2021] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease is a quintessential 'unmet medical need', accounting for ∼65% of progressive cognitive impairment among the elderly, and 700,000 deaths in the United States in 2020. In 2019, the cost of caring for Alzheimer's sufferers was $244B, not including the emotional and physical toll on caregivers. In spite of this dismal reality, no treatments are available that reduce the risk of developing AD or that offer prolonged mitiagation of its most devestating symptoms. This review summarizes key aspects of the biology and genetics of Alzheimer's disease, and we describe how pioglitazone improves many of the patholophysiological determinants of AD. We also summarize the results of pre-clinical experiments, longitudinal observational studies, and clinical trials. The results of animal testing suggest that pioglitazone can be corrective as well as protective, and that its efficacy is enhanced in a time- and dose-dependent manner, but the dose-effect relations are not monotonic or sigmoid. Longitudinal cohort studies suggests that it delays the onset of dementia in individuals with pre-existing type 2 diabetes mellitus, which small scale, unblinded pilot studies seem to confirm. However, the results of placebo-controlled, blinded clinical trials have not borne this out, and we discuss possible explanations for these discrepancies.
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Affiliation(s)
- Ann M. Saunders
- Zinfandel Pharmaceuticals, Inc., Chapel Hill, NC, United States
| | - Daniel K. Burns
- Zinfandel Pharmaceuticals, Inc., Chapel Hill, NC, United States
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Bianchi L, Sframeli M, Vantaggiato L, Vita GL, Ciranni A, Polito F, Oteri R, Gitto E, Di Giuseppe F, Angelucci S, Versaci A, Messina S, Vita G, Bini L, Aguennouz M. Nusinersen Modulates Proteomics Profiles of Cerebrospinal Fluid in Spinal Muscular Atrophy Type 1 Patients. Int J Mol Sci 2021; 22:ijms22094329. [PMID: 33919289 PMCID: PMC8122268 DOI: 10.3390/ijms22094329] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/19/2021] [Indexed: 02/06/2023] Open
Abstract
Spinal muscular atrophy (SMA) type 1 is a severe infantile autosomal-recessive neuromuscular disorder caused by a survival motor neuron 1 gene (SMN1) mutation and characterized by progressive muscle weakness. Without supportive care, SMA type 1 is rapidly fatal. The antisense oligonucleotide nusinersen has recently improved the natural course of this disease. Here, we investigated, with a functional proteomic approach, cerebrospinal fluid (CSF) protein profiles from SMA type 1 patients who underwent nusinersen administration to clarify the biochemical response to the treatment and to monitor disease progression based on therapy. Six months after starting treatment (12 mg/5 mL × four doses of loading regimen administered at days 0, 14, 28, and 63), we observed a generalized reversion trend of the CSF protein pattern from our patient cohort to that of control donors. Notably, a marked up-regulation of apolipoprotein A1 and apolipoprotein E and a consistent variation in transthyretin proteoform occurrence were detected. Since these multifunctional proteins are critically active in biomolecular processes aberrant in SMA, i.e., synaptogenesis and neurite growth, neuronal survival and plasticity, inflammation, and oxidative stress control, their nusinersen induced modulation may support SMN improved-expression effects. Hence, these lipoproteins and transthyretin could represent valuable biomarkers to assess patient responsiveness and disease progression.
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Affiliation(s)
- Laura Bianchi
- Functional Proteomics Laboratory, Department of Life Sciences, University of Siena, 53100 Siena, Italy; (L.B.); (L.V.); (L.B.)
| | - Maria Sframeli
- Nemo Sud Clinical Centre, 98125 Messina, Italy; (M.S.); (G.L.V.)
| | - Lorenza Vantaggiato
- Functional Proteomics Laboratory, Department of Life Sciences, University of Siena, 53100 Siena, Italy; (L.B.); (L.V.); (L.B.)
| | - Gian Luca Vita
- Nemo Sud Clinical Centre, 98125 Messina, Italy; (M.S.); (G.L.V.)
| | - Annamaria Ciranni
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
| | - Francesca Polito
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
| | - Rosaria Oteri
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
| | - Eloisa Gitto
- Neonatal and Paediatric Intensive Care Unit, Department of Human Pathology in Adult and Developmental Age, University of Messina, 98125 Messina, Italy;
| | - Fabrizio Di Giuseppe
- Dentistry and Biotechnology, and Proteomics Unit, Centre of Advanced Studies and Technoloy, Department Medical, Oral & Biotechnological Sciences, “G. d’Annunzio”, University of Chieti-Pescara, 66100 Chieti, Italy; (F.D.G.); (S.A.)
| | - Stefania Angelucci
- Dentistry and Biotechnology, and Proteomics Unit, Centre of Advanced Studies and Technoloy, Department Medical, Oral & Biotechnological Sciences, “G. d’Annunzio”, University of Chieti-Pescara, 66100 Chieti, Italy; (F.D.G.); (S.A.)
| | - Antonio Versaci
- Intensive Care Unit, AOU Policlinico “G. Martino”, 98125 Messina, Italy;
| | - Sonia Messina
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
| | - Giuseppe Vita
- Nemo Sud Clinical Centre, 98125 Messina, Italy; (M.S.); (G.L.V.)
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
- Correspondence:
| | - Luca Bini
- Functional Proteomics Laboratory, Department of Life Sciences, University of Siena, 53100 Siena, Italy; (L.B.); (L.V.); (L.B.)
| | - M’hammed Aguennouz
- Unit of Neurology and Neuromuscular Diseases, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy; (A.C.); (F.P.); (R.O.); (S.M.); (M.A.)
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Precision Nutrition for Alzheimer's Prevention in ApoE4 Carriers. Nutrients 2021; 13:nu13041362. [PMID: 33921683 PMCID: PMC8073598 DOI: 10.3390/nu13041362] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022] Open
Abstract
The ApoE4 allele is the most well-studied genetic risk factor for Alzheimer’s disease, a condition that is increasing in prevalence and remains without a cure. Precision nutrition targeting metabolic pathways altered by ApoE4 provides a tool for the potential prevention of disease. However, no long-term human studies have been conducted to determine effective nutritional protocols for the prevention of Alzheimer’s disease in ApoE4 carriers. This may be because relatively little is yet known about the precise mechanisms by which the genetic variant confers an increased risk of dementia. Fortunately, recent research is beginning to shine a spotlight on these mechanisms. These new data open up the opportunity for speculation as to how carriers might ameliorate risk through lifestyle and nutrition. Herein, we review recent discoveries about how ApoE4 differentially impacts microglia and inflammatory pathways, astrocytes and lipid metabolism, pericytes and blood–brain barrier integrity, and insulin resistance and glucose metabolism. We use these data as a basis to speculate a precision nutrition approach for ApoE4 carriers, including a low-glycemic index diet with a ketogenic option, specific Mediterranean-style food choices, and a panel of seven nutritional supplements. Where possible, we integrate basic scientific mechanisms with human observational studies to create a more complete and convincing rationale for this precision nutrition approach. Until recent research discoveries can be translated into long-term human studies, a mechanism-informed practical clinical approach may be useful for clinicians and patients with ApoE4 to adopt a lifestyle and nutrition plan geared towards Alzheimer’s risk reduction.
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Glapa-Nowak A, Szczepanik M, Iwańczak B, Kwiecień J, Szaflarska-Popławska AB, Grzybowska-Chlebowczyk U, Osiecki M, Dziekiewicz M, Stawarski A, Kierkuś J, Banasiewicz T, Banaszkiewicz A, Walkowiak J. Apolipoprotein E variants correlate with the clinical presentation of paediatric inflammatory bowel disease: A cross-sectional study. World J Gastroenterol 2021; 27:1483-1496. [PMID: 33911469 PMCID: PMC8047531 DOI: 10.3748/wjg.v27.i14.1483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/17/2020] [Accepted: 02/25/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND It has been suggested that apolipoprotein E (APOE) polymorphisms are associated with the risk of developing inflammatory bowel disease (IBD) and the early age of disease onset. However, there are no reports regarding the relationship with clinical characteristics and disease severity.
AIM To summarise that APOE polymorphisms are associated with the risk of developing IBD and the early age of disease onset.
METHODS In total, 406 patients aged 3-18 with IBD (192 had ulcerative colitis and 214 had Crohn’s disease) were genotyped using the TaqMan hydrolysis probe assay. Clinical expression was described at diagnosis and the worst flare by disease activity scales, albumin and C-reactive protein levels, localisation and behaviour (Paris classification). Systemic steroid intake with the total number of courses, immunosuppressive, biological, and surgical treatment with the time and age of the first intervention were determined. The total number of exacerbation-caused hospitalisations, the number of days spent in hospital due to exacerbation, the number of relapses, and severe relapses were also estimated.
RESULTS Ulcerative colitis patients with the APOEε4 allele had lower C-reactive protein values at diagnosis (P = 0.0435) and the worst flare (P = 0.0013) compared to patients with the APOEε2 allele and genotype APOEε3/ε3. Crohn’s disease patients with the APOEε2 allele scored lower on the Pediatric Crohn’s Disease Activity Index at diagnosis (P = 0.0204). IBD patients with APOEε2 allele spent fewer days in the hospital due to relapse (P = 0.0440).
CONCLUSION APOE polymorphisms are associated with the risk of developing IBD and the clinical expression of IBD. However, the clinical relevance of the differences identified is rather modest.
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Affiliation(s)
- Aleksandra Glapa-Nowak
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznań University of Medical Sciences, Poznań 60-572, Poland
| | - Mariusz Szczepanik
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznań University of Medical Sciences, Poznań 60-572, Poland
| | - Barbara Iwańczak
- Department of Pediatrics, Medical University of Wroclaw, Wroclaw 50-369, Poland
| | - Jarosław Kwiecień
- Department of Pediatrics, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Zabrze 41-800, Poland
| | | | - Urszula Grzybowska-Chlebowczyk
- Department of Pediatrics, Faculty of Medical Sciences, Medical University of Silesia in Katowice, Katowice 40-752, Poland
| | - Marcin Osiecki
- Department of Gastroenterology, Hepatology, Feeding Disorders and Paediatrics, The Children’s Memorial Health Institute, Warsaw 04-730, Poland
| | - Marcin Dziekiewicz
- Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw, Warsaw 02-091, Poland
| | - Andrzej Stawarski
- Department and Clinic of Pediatrics, Gastroenterology and Nutrition, Wroclaw Medical University, Wroclaw 50-369, Poland
| | - Jarosław Kierkuś
- Department of Gastroenterology, Hepatology, Feeding Disorders and Paediatrics, The Children’s Memorial Health Institute, Warsaw 04-730, Poland
| | - Tomasz Banasiewicz
- Chair and Department of General Surgery, Gastroenterological Surgical Oncology and Plastic Surgery, Poznań University of Medical Sciences, Poznań 60-355, Poland
| | - Aleksandra Banaszkiewicz
- Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw, Warsaw 02-091, Poland
| | - Jarosław Walkowiak
- Department of Pediatric Gastroenterology and Metabolic Diseases, Poznań University of Medical Sciences, Poznań 60-572, Poland
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Chen Y, Hong T, Chen F, Sun Y, Wang Y, Cui L. Interplay Between Microglia and Alzheimer's Disease-Focus on the Most Relevant Risks: APOE Genotype, Sex and Age. Front Aging Neurosci 2021; 13:631827. [PMID: 33897406 PMCID: PMC8060487 DOI: 10.3389/fnagi.2021.631827] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 03/18/2021] [Indexed: 12/20/2022] Open
Abstract
As the main immune cells of the central nervous system (CNS), microglia regulates normal development, homeostasis and general brain physiology. These functions put microglia at the forefront of CNS repair and recovery. Uncontrolled activation of microglia is related to the course of neurodegenerative diseases such as Alzheimer’s disease. It is clear that the classic pathologies of amyloid β (Aβ) and Tau are usually accompanied by the activation of microglia, and the activation of microglia also serves as an early event in the pathogenesis of AD. Therefore, during the occurrence and development of AD, the key susceptibility factors for AD—apolipoprotein E (APOE) genotype, sex and age—may further interact with microglia to exacerbate neurodegeneration. In this review, we discuss the role of microglia in the progression of AD related to the three risk factors for AD: APOE genotype, sex and aging. APOE-expressing microglia accumulates around Aβ plaques, and the presence of APOE4 may disrupt the phagocytosis of Aβ aggregates and aggravate neurodegeneration in Tau disease models. In addition, females have a high incidence of AD, and normal female microglia and estrogen have protective effects under normal conditions. However, under the influence of AD, female microglia seem to lose their protective effect and instead accelerate the course of AD. Aging, another major risk factor, may increase the sensitivity of microglia, leading to the exacerbation of microglial dysfunction in elderly AD. Obviously, in the role of microglia in AD, the three main risk factors of APOE, sex, and aging are not independent and have synergistic effects that contribute to the risk of AD. Moreover, new microglia can replace dysfunctional microglia after microglial depletion, which is a new promising strategy for AD treatment.
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Affiliation(s)
- Yanting Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Tingting Hong
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Feng Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, 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, United States
| | - Yan Wang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Department of Neurology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China
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17
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Shi M, Chu F, Tian X, Aerqin Q, Zhu F, Zhu J. Role of Adaptive Immune and Impacts of Risk Factors on Adaptive Immune in Alzheimer's Disease: Are Immunotherapies Effective or Off-Target? Neuroscientist 2021; 28:254-270. [PMID: 33530843 DOI: 10.1177/1073858420987224] [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: 12/12/2022]
Abstract
The pathogenesis of Alzheimer's disease (AD) is complex. Still it remains unclear, which resulted in all efforts for AD treatments with targeting the pathogenic factors unsuccessful over past decades. It has been evidenced that the innate immune is strongly implicated in the pathogenesis of AD. However, the role of adaptive immune in AD remains mostly unknown and the results obtained were controversial. In the review, we summarized recent studies and showed that the molecular and cellular alterations in AD patients and its animal models involving T cells and B cells as well as immune mediators of adaptive immune occur not only in the peripheral blood but also in the brain and the cerebrospinal fluid. The risk factors that cause AD contribute to AD progress by affecting the adaptive immune, indicating that adaptive immunity proposes a pivotal role in this disease. It may provide a possible basis for applying immunotherapy in AD and further investigates whether the immunotherapies are effective or off-target?
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Affiliation(s)
- Mingchao Shi
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.,Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrcs, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Fengna Chu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.,Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrcs, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Xiaoping Tian
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University Medical College, Shenzhen, China
| | - Qiaolifan Aerqin
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Feiqi Zhu
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University Medical College, Shenzhen, China
| | - Jie Zhu
- Neuroscience Center, Department of Neurology, The First Hospital of Jilin University, Changchun, China.,Department of Neurobiology, Care Sciences & Society, Division of Neurogeriatrcs, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
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18
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Montine TJ, Bukhari SA, White LR. Cognitive Impairment in Older Adults and Therapeutic Strategies. Pharmacol Rev 2021; 73:152-162. [PMID: 33298513 PMCID: PMC7736830 DOI: 10.1124/pharmrev.120.000031] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 10/12/2020] [Indexed: 12/12/2022] Open
Abstract
Cognitive impairment and its severe form dementia are increasingly prevalent in older adults and loom as a public health disaster unless effective interventions are developed. Cognitive impairment is a convergent trait caused by damage from an idiosyncratic mix of four prevalent diseases (Alzheimer disease; vascular brain injury; Lewy body diseases, such as Parkinson disease and dementia with Lewy bodies; and limbic-predominant age-related transactive response DNA-binding protein 43 encephalopathy) that is counterbalanced by individually varying resilience, which is comprised of reserve and compensation. Brain regional damage from each of these four prevalent diseases is generated by the net effect of injury and (mal)adaptive response and is accompanied by characteristic lesions. Existing therapeutics enhance resilience, whereas most agents under development target mechanisms of damage with only suppression of vascular brain injury yet to show therapeutic promise. We hope to anticipate future tailored interventions that target mechanisms of damage and thereby avert the oncoming surge of cognitive impairment and dementia in older adults. SIGNIFICANCE STATEMENT: Brain regional damage is generated by the net effect of injury and (mal)adaptive response. The extent to which signs and symptoms of such damage occur is influenced by an underlying resilience comprising reserve and compensation. Finding tailored interventions that target specific mechanisms of damage likely yields the most effective therapies.
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Affiliation(s)
- Thomas J Montine
- Department of Pathology, Stanford University, Stanford, California (T.J.M., S.A.B.) and Pacific Health Research and Education Institute, Honolulu, Hawaii (L.R.W.)
| | - Syed A Bukhari
- Department of Pathology, Stanford University, Stanford, California (T.J.M., S.A.B.) and Pacific Health Research and Education Institute, Honolulu, Hawaii (L.R.W.)
| | - Lon R White
- Department of Pathology, Stanford University, Stanford, California (T.J.M., S.A.B.) and Pacific Health Research and Education Institute, Honolulu, Hawaii (L.R.W.)
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19
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Zhao B, Wang W, Chen Z, Jin S. Apolipoprotein E deficiency enhances the anti-tumor immunity via repressing T cell exhaustion. ALL LIFE 2021. [DOI: 10.1080/26895293.2021.2001382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Bian Zhao
- Department of Pharmacy, Luohe Medical College, Luohe, People’s Republic of China
| | - Wenbao Wang
- Department of Pharmacy, Luohe Medical College, Luohe, People’s Republic of China
| | - Zhijun Chen
- Department of Pharmacy, Luohe Hospital of Traditional Chinese Medicine, Luohe, People’s Republic of China
| | - Shaoju Jin
- Department of Pharmacy, Luohe Medical College, Luohe, People’s Republic of China
- Tumor Occurrence and Prevention Research Innovation Team of Henan, Luohe, People’s Republic of China
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20
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Cancer Chemotherapy Related Cognitive Impairment and the Impact of the Alzheimer's Disease Risk Factor APOE. Cancers (Basel) 2020; 12:cancers12123842. [PMID: 33352780 PMCID: PMC7766535 DOI: 10.3390/cancers12123842] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/16/2020] [Accepted: 12/16/2020] [Indexed: 12/16/2022] Open
Abstract
Cancer related cognitive impairment (CRCI) is a serious impairment to maintaining quality of life in cancer survivors. Cancer chemotherapy contributes to this condition through several potential mechanisms, including damage to the blood brain barrier, increases in oxidative stress and inflammation in the brain, and impaired neurogenesis, each of which lead to neuronal dysfunction. A genetic predisposition to CRCI is the E4 allele of the Apolipoprotein E gene (APOE), which is also the strongest genetic risk factor for Alzheimer's disease. In normal brains, APOE performs essential lipid transport functions. The APOE4 isoform has been linked to altered lipid binding, increased oxidative stress and inflammation, reduced turnover of neural progenitor cells, and impairment of the blood brain barrier. As chemotherapy also affects these processes, the influence of APOE4 on CRCI takes on great significance. This review outlines the main areas where APOE genotype could play a role in CRCI. Potential therapeutics based on APOE biology could mitigate these detrimental cognitive effects for those receiving chemotherapy, emphasizing that the APOE genotype could help in developing personalized cancer treatment regimens.
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21
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Li Z, Shue F, Zhao N, Shinohara M, Bu G. APOE2: protective mechanism and therapeutic implications for Alzheimer's disease. Mol Neurodegener 2020; 15:63. [PMID: 33148290 PMCID: PMC7640652 DOI: 10.1186/s13024-020-00413-4] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 10/17/2020] [Indexed: 02/06/2023] Open
Abstract
Investigations of apolipoprotein E (APOE) gene, the major genetic risk modifier for Alzheimer's disease (AD), have yielded significant insights into the pathogenic mechanism. Among the three common coding variants, APOE*ε4 increases, whereas APOE*ε2 decreases the risk of late-onset AD compared with APOE*ε3. Despite increased understanding of the detrimental effect of APOE*ε4, it remains unclear how APOE*ε2 confers protection against AD. Accumulating evidence suggests that APOE*ε2 protects against AD through both amyloid-β (Aβ)-dependent and independent mechanisms. In addition, APOE*ε2 has been identified as a longevity gene, suggesting a systemic effect of APOE*ε2 on the aging process. However, APOE*ε2 is not entirely benign; APOE*ε2 carriers exhibit increased risk of certain cerebrovascular diseases and neurological disorders. Here, we review evidence from both human and animal studies demonstrating the protective effect of APOE*ε2 against AD and propose a working model depicting potential underlying mechanisms. Finally, we discuss potential therapeutic strategies designed to leverage the protective effect of APOE2 to treat AD.
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Affiliation(s)
- Zonghua Li
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Francis Shue
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic, Jacksonville, FL, USA
| | - Na Zhao
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Mitsuru Shinohara
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, 7-430 Morioka, Obu, Aichi, 474-8511, Japan.
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
- Neuroscience Graduate Program, Mayo Clinic, Jacksonville, FL, USA.
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22
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Ayton S, Janelidze S, Roberts B, Palmqvist S, Kalinowski P, Diouf I, Belaidi AA, Stomrud E, Bush AI, Hansson O. Acute phase markers in CSF reveal inflammatory changes in Alzheimer's disease that intersect with pathology, APOE ε4, sex and age. Prog Neurobiol 2020; 198:101904. [PMID: 32882319 DOI: 10.1016/j.pneurobio.2020.101904] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 01/31/2023]
Abstract
It is unknown how neuroinflammation may feature in the etiology of Alzheimer's disease (AD). We profiled acute phase response (APR) proteins (α1-antitrypsin, α1-antichymotrypsin, ceruloplasmin, complement C3, ferritin, α-fibrinogen, β-fibrinogen, γ-fibrinogen, haptoglobin, hemopexin) in CSF of 1291 subjects along the clinical and biomarker spectrum of AD to investigate the association between inflammatory changes, disease outcomes, and demographic variables. Subjects were stratified by Aβ42/t-tau as well as the following clinical diagnoses: cognitively normal (CN); subjective cognitive decline (SCD); mild cognitive impairment (MCI); and AD dementia. In separate multiple regressions (adjusting for diagnosis, age, sex, APOE-ε4) of each APR protein and a composite of all APR proteins, CSF Aβ42/t-tau status was associated with elevated ferritin, but not any other APR protein in CN and SCD subjects. Rather, the APR was elevated along with symptomatic progression (CN < SCD < MCI < AD), and this was elevation was mediated by CSF p-tau181. APOE ε4 status did not affect levels of any APR proteins in CSF, while these were elevated in males and with increased age. The performance of the APR in predicting clinical diagnosis was influenced by APOE ε4 status, sex, and age. These data provide new insight into inflammatory changes in AD and how this intersects with pathology changes and patient demographics.
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Affiliation(s)
- Scott Ayton
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Shorena Janelidze
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Blaine Roberts
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Sebastian Palmqvist
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Pawel Kalinowski
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Ibrahima Diouf
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Abdel A Belaidi
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia
| | - Erik Stomrud
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Ashley I Bush
- Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia.
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences, Malmö, Lund University, Sweden; Memory Clinic, Skåne University Hospital, Malmö, Sweden.
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Raman S, Brookhouser N, Brafman DA. Using human induced pluripotent stem cells (hiPSCs) to investigate the mechanisms by which Apolipoprotein E (APOE) contributes to Alzheimer's disease (AD) risk. Neurobiol Dis 2020; 138:104788. [PMID: 32032733 PMCID: PMC7098264 DOI: 10.1016/j.nbd.2020.104788] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 01/14/2020] [Accepted: 01/31/2020] [Indexed: 01/02/2023] Open
Abstract
Although the biochemical and pathological hallmarks of Alzheimer's disease (AD), such as axonal transport defects, synaptic loss, and selective neuronal death, are well characterized, the underlying mechanisms that cause AD are largely unknown, thereby making it difficult to design effective therapeutic interventions. Genome-wide association studies (GWAS) studies have identified several factors associated with increased AD risk. Of these genetic factors, polymorphisms in the Apolipoprotein E (APOE) gene are the strongest and most prevalent. While it has been established that the ApoE protein modulates the formation of amyloid plaques and neurofibrillary tangles, the precise molecular mechanisms by which various ApoE isoforms enhance or mitigate AD onset and progression in aging adults are yet to be elucidated. Advances in cellular reprogramming to generate disease-in-a-dish models now provide a simplified and accessible system that complements animal and primary cell models to study ApoE in the context of AD. In this review, we will describe the use and manipulation of human induced pluripotent stem cells (hiPSCs) in dissecting the interaction between ApoE and AD. First, we will provide an overview of the proposed roles that ApoE plays in modulating pathophysiology of AD. Next, we will summarize the recent studies that have employed hiPSCs to model familial and sporadic AD. Lastly, we will speculate on how current advances in genome editing technologies and organoid culture systems can be used to improve hiPSC-based tools to investigate ApoE-dependent modulation of AD onset and progression.
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Affiliation(s)
- Sreedevi Raman
- School of Biological and Health Systems Engineering, Arizona State University, United States of America
| | - Nicholas Brookhouser
- School of Biological and Health Systems Engineering, Arizona State University, United States of America; Graduate Program in Clinical Translational Sciences, University of Arizona College of Medicine-Phoenix, United States of America
| | - David A Brafman
- School of Biological and Health Systems Engineering, Arizona State University, United States of America.
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Associations between brain inflammatory profiles and human neuropathology are altered based on apolipoprotein E ε4 genotype. Sci Rep 2020; 10:2924. [PMID: 32076055 PMCID: PMC7031423 DOI: 10.1038/s41598-020-59869-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 02/05/2020] [Indexed: 12/16/2022] Open
Abstract
Alzheimer disease (AD) is a chronic neurodegenerative disease with a multitude of contributing genetic factors, many of which are related to inflammation. The apolipoprotein E (APOE) ε4 allele is the most common genetic risk factor for AD and is related to a pro-inflammatory state. To test the hypothesis that microglia and AD-implicated cytokines were differentially associated with AD pathology based on the presence of APOE ε4, we examined the dorsolateral frontal cortex from deceased participants within a community-based aging cohort (n = 154). Cellular density of Iba1, a marker of microglia, was positively associated with tau pathology only in APOE ε4 positive participants (p = 0.001). The cytokines IL-10, IL-13, IL-4, and IL-1α were negatively associated with tau pathology, independent of Aβ1–42 levels, only in APOE ε4 negative participants. Overall, the association of mostly anti-inflammatory cytokines with less tau pathology suggests a protective effect in APOE ε4 negative participants. These associations are largely absent in the presence of APOE ε4 where tau pathology was significantly associated with increased microglial cell density. Taken together, these results suggest that APOE ε4 mediates an altered inflammatory response and increased tau pathology independent of Aβ1–42 pathology.
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25
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Williams T, Borchelt DR, Chakrabarty P. Therapeutic approaches targeting Apolipoprotein E function in Alzheimer's disease. Mol Neurodegener 2020; 15:8. [PMID: 32005122 PMCID: PMC6995170 DOI: 10.1186/s13024-020-0358-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
One of the primary genetic risk factors for Alzheimer’s disease (AD) is the presence of the Ɛ4 allele of apolipoprotein E (APOE). APOE is a polymorphic lipoprotein that is a major cholesterol carrier in the brain. It is also involved in various cellular functions such as neuronal signaling, neuroinflammation and glucose metabolism. Humans predominantly possess three different allelic variants of APOE, termed E2, E3, and E4, with the E3 allele being the most common. The presence of the E4 allele is associated with increased risk of AD whereas E2 reduces the risk. To understand the molecular mechanisms that underlie APOE-related genetic risk, considerable effort has been devoted towards developing cellular and animal models. Data from these models indicate that APOE4 exacerbates amyloid β plaque burden in a dose-dependent manner. and may also enhance tau pathogenesis in an isoform-dependent manner. Other studies have suggested APOE4 increases the risk of AD by mechanisms that are distinct from modulation of Aβ or tau pathology. Further, whether plasma APOE, by influencing systemic metabolic pathways, can also possibly alter CNS function indirectly is not complete;y understood. Collectively, the available studies suggest that APOE may impact multiple signaling pathways and thus investigators have sought therapeutics that would disrupt pathological functions of APOE while preserving or enhancing beneficial functions. This review will highlight some of the therapeutic strategies that are currently being pursued to target APOE4 towards preventing or treating AD and we will discuss additional strategies that holds promise for the future.
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Affiliation(s)
- Tosha Williams
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA
| | - David R Borchelt
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA.,McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Paramita Chakrabarty
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA. .,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA. .,McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
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26
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Ben-Moshe H, Luz I, Liraz O, Boehm-Cagan A, Salomon-Zimri S, Michaelson D. ApoE4 Exacerbates Hippocampal Pathology Following Acute Brain Penetration Injury in Female Mice. J Mol Neurosci 2019; 70:32-44. [DOI: 10.1007/s12031-019-01397-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 08/14/2019] [Indexed: 10/26/2022]
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27
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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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28
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Abstract
BACKGROUND The growing body of evidence indicating the heterogeneity of Alzheimer's disease (AD), coupled with disappointing clinical studies directed at a fit-for-all therapy, suggest that the development of a single magic cure suitable for all cases may not be possible. This calls for a shift in paradigm where targeted treatment is developed for specific AD subpopulations that share distinct genetic or pathological properties. Apolipoprotein E4 (apoE4), the most prevalent genetic risk factor of AD, is expressed in more than half of AD patients and is thus an important possible AD therapeutic target. REVIEW This review focuses initially on the pathological effects of apoE4 in AD, as well as on the corresponding cellular and animal models and the suggested cellular and molecular mechanisms which mediate them. The second part of the review focuses on recent apoE4-targeted (from the APOE gene to the apoE protein and its interactors) therapeutic approaches that have been developed in animal models and are ready to be translated to human. Further, the issue of whether the pathological effects of apoE4 are due to loss of protective function or due to gain of toxic function is discussed herein. It is possible that both mechanisms coexist, with certain constituents of the apoE4 molecule and/or its downstream signaling mediating a toxic effect, while others are associated with a loss of protective function. CONCLUSION ApoE4 is a promising AD therapeutic target that remains understudied. Recent studies are now paving the way for effective apoE4-directed AD treatment approaches.
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Fernandez CG, Hamby ME, McReynolds ML, Ray WJ. The Role of APOE4 in Disrupting the Homeostatic Functions of Astrocytes and Microglia in Aging and Alzheimer's Disease. Front Aging Neurosci 2019; 11:14. [PMID: 30804776 PMCID: PMC6378415 DOI: 10.3389/fnagi.2019.00014] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/16/2019] [Indexed: 12/20/2022] Open
Abstract
APOE4 is the greatest genetic risk factor for late-onset Alzheimer’s disease (AD), increasing the risk of developing the disease by 3-fold in the 14% of the population that are carriers. Despite 25 years of research, the exact mechanisms underlying how APOE4 contributes to AD pathogenesis remain incompletely defined. APOE in the brain is primarily expressed by astrocytes and microglia, cell types that are now widely appreciated to play key roles in the pathogenesis of AD; thus, a picture is emerging wherein APOE4 disrupts normal glial cell biology, intersecting with changes that occur during normal aging to ultimately cause neurodegeneration and cognitive dysfunction. This review article will summarize how APOE4 alters specific pathways in astrocytes and microglia in the context of AD and the aging brain. APOE itself, as a secreted lipoprotein without enzymatic activity, may prove challenging to directly target therapeutically in the classical sense. Therefore, a deeper understanding of the underlying pathways responsible for APOE4 toxicity is needed so that more tractable pathways and drug targets can be identified to reduce APOE4-mediated disease risk.
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Affiliation(s)
- Celia G Fernandez
- The Neurodegeneration Consortium, Institute of Applied Cancer Science (IACS), The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Mary E Hamby
- The Neurodegeneration Consortium, Institute of Applied Cancer Science (IACS), The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Morgan L McReynolds
- The Neurodegeneration Consortium, Institute of Applied Cancer Science (IACS), The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - William J Ray
- The Neurodegeneration Consortium, Institute of Applied Cancer Science (IACS), The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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Risk Factors and Pathogenesis of HIV-Associated Neurocognitive Disorder: The Role of Host Genetics. Int J Mol Sci 2018; 19:ijms19113594. [PMID: 30441796 PMCID: PMC6274730 DOI: 10.3390/ijms19113594] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 02/06/2023] Open
Abstract
Neurocognitive impairments associated with human immunodeficiency virus (HIV) infection remain a considerable health issue for almost half the people living with HIV, despite progress in HIV treatment through combination antiretroviral therapy (cART). The pathogenesis and risk factors of HIV-associated neurocognitive disorder (HAND) are still incompletely understood. This is partly due to the complexity of HAND diagnostics, as phenotypes present with high variability and change over time. Our current understanding is that HIV enters the central nervous system (CNS) during infection, persisting and replicating in resident immune and supporting cells, with the subsequent host immune response and inflammation likely adding to the development of HAND. Differences in host (human) genetics determine, in part, the effectiveness of the immune response and other factors that increase the vulnerability to HAND. This review describes findings from studies investigating the role of human host genetics in the pathogenesis of HAND, including potential risk factors for developing HAND. The similarities and differences between HAND and Alzheimer's disease are also discussed. While some specific variations in host genes regulating immune responses and neurotransmission have been associated with protection or risk of HAND development, the effects are generally small and findings poorly replicated. Nevertheless, a few specific gene variants appear to affect the risk for developing HAND and aid our understanding of HAND pathogenesis.
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31
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Clark IA, Vissel B. Therapeutic implications of how TNF links apolipoprotein E, phosphorylated tau, α-synuclein, amyloid-β and insulin resistance in neurodegenerative diseases. Br J Pharmacol 2018; 175:3859-3875. [PMID: 30097997 PMCID: PMC6151331 DOI: 10.1111/bph.14471] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/26/2018] [Accepted: 07/23/2018] [Indexed: 12/24/2022] Open
Abstract
While cytokines such as TNF have long been recognized as essential to normal cerebral physiology, the implications of their chronic excessive production within the brain are now also increasingly appreciated. Syndromes as diverse as malaria and lead poisoning, as well as non‐infectious neurodegenerative diseases, illustrate this. These cytokines also orchestrate changes in tau, α‐synuclein, amyloid‐β levels and degree of insulin resistance in most neurodegenerative states. New data on the effects of salbutamol, an indirect anti‐TNF agent, on α‐synuclein and Parkinson's disease, APOE4 and tau add considerably to the rationale of the anti‐TNF approach to understanding, and treating, these diseases. Therapeutic advances being tested, and arguably useful for a number of the neurodegenerative diseases, include a reduction of excess cerebral TNF, whether directly, with a specific anti‐TNF biological agent such as etanercept via Batson's plexus, or indirectly via surgically implanting stem cells. Inhaled salbutamol also warrants investigating further across the neurodegenerative disease spectrum. It is now timely to integrate this range of new information across the neurodegenerative disease spectrum, rather than keep seeing it through the lens of individual disease states.
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Affiliation(s)
- I A Clark
- Research School of Biology, Australian National University, Canberra, Australia
| | - B Vissel
- Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology, Sydney, NSW, Australia.,St. Vincent's Centre for Applied Medical Research, Sydney, NSW, Australia
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32
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Aging and Apolipoprotein E in HIV Infection. J Neurovirol 2018; 24:529-548. [PMID: 29987582 PMCID: PMC6244718 DOI: 10.1007/s13365-018-0660-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/23/2018] [Accepted: 06/25/2018] [Indexed: 01/21/2023]
Abstract
With the implementation of increasingly effective antiretroviral therapy (ART) over the past three decades, individuals infected with HIV live a much longer life. HIV infection is no longer a terminal but rather a chronic disease. However, the lifespan of infected individuals remains shorter than that of their uninfected peers. Even with ART, HIV infection may potentiate “premature” aging. Organ-associated disease and systemic syndromes that occur in treated HIV-infection are like that of older, uninfected individuals. Brain aging may manifest as structural changes or neurocognitive impairment that are beyond the chronological age. The spectrum of neurological, cognitive, and motor deficiencies, currently described as HIV-associated neurocognitive disorders (HAND), may reflect earlier onset of mechanisms common to HIV infection and aging (accelerated aging). HAND could also reflect the neurological impact of HIV infection superimposed on comorbidities linked to age and chronic inflammation, leading to a higher prevalence of neurocognitive impairment across the age span (accentuated aging). In addition, apolipoprotein E (ApoE), one of the most influential host risk factors for developing Alzheimer’s disease, has been implicated in the development of HAND. But studies differ as to whether ApoE is relevant, and whether age and ApoE interact to impair brain function in the HIV-infected patient. What is clear is that HIV-infected individuals are living longer with HIV, and therefore factors related to aging and health need to be examined in the context of current, effective ART. This review addresses the recent evidence for the influence of aging and ApoE on HIV-associated neurocognitive impairment.
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Abstract
The Apolipoprotein E (ApoE) isotype ApoE4 is a prevalent genetic risk factor for Alzheimer's disease (AD) that can modulate systemic and central inflammation, independent of amyloid accumulation. Although disruption of innate immune toll receptor signaling is modulated by ApoE and observed in AD, ApoE isotype-specific effects remain poorly understood. Therefore, we examined the effect of the ApoE isotype on the brain levels of major regulators of TLR signaling including miR146a, a microRNA enriched in the brain. We used 6-month-old ApoE3 or ApoE4 targeted replacement mice with and without mutant familial AD transgenes. ApoE4 reduced the levels of miR146a compared with ApoE3, both in the brain (29%; P<0.0001) and in plasma (47%; P<0.05), which correlated with each other (r=0.74; P<0.05). The presence of 5xFAD transgenes increased brain miR146a in both ApoE3 (E3FAD) and ApoE4 (E4FAD) mice; however, miR146a levels in E4FAD mice remained lower than those in E3FAD mice (62%; P<0.05), despite increased amyloid and inflammation. Supporting these observations, ApoE4 brains showed increased expression of interleukin receptor-associated kinase-1 (160%; P<0.05) (normally downregulated by miR146) that correlated inversely with miR146a levels (r=0.637; P<0.0001). Reduced negative feedback of toll-like receptor signaling (by miRNA146a) can explain early-life hypersensitivity to innate immune stimuli (including Aβ) in ApoE4 carriers. Thus, ApoE4 causes early dysregulation of a central controller of the innate immune system both centrally and systemically. This defect persists with familial AD pathology and may be relevant to ApoE4 AD risk.
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34
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Chen YJ, Nguyen HM, Maezawa I, Jin LW, Wulff H. Inhibition of the potassium channel Kv1.3 reduces infarction and inflammation in ischemic stroke. Ann Clin Transl Neurol 2017; 5:147-161. [PMID: 29468176 PMCID: PMC5817832 DOI: 10.1002/acn3.513] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/10/2017] [Accepted: 11/20/2017] [Indexed: 12/26/2022] Open
Abstract
Objective Inhibitors of the voltage‐gated K+ channel Kv1.3 are currently in development as immunomodulators for the treatment of autoimmune diseases. As Kv1.3 is also expressed on microglia and has been shown to be specifically up‐regulated on “M1‐like” microglia, we here tested the therapeutic hypothesis that the brain‐penetrant small‐molecule Kv1.3‐inhibitor PAP‐1 reduces secondary inflammatory damage after ischemia/reperfusion. Methods We studied microglial Kv1.3 expression using electrophysiology and immunohistochemistry, and evaluated PAP‐1 in hypoxia‐exposed organotypic hippocampal slices and in middle cerebral artery occlusion (MCAO) with 8 days of reperfusion in both adult male C57BL/6J mice (60 min MCAO) and adult male Wistar rats (90 min MCAO). In both models, PAP‐1 administration was started 12 h after reperfusion. Results We observed Kv1.3 staining on activated microglia in ischemic infarcts in mice, rats, and humans and found higher Kv1.3 current densities in acutely isolated microglia from the infarcted hemisphere than in microglia isolated from the contralateral hemisphere of MCAO mice. PAP‐1 reduced microglia activation and increased neuronal survival in hypoxia‐exposed hippocampal slices as effectively as minocycline. In mouse MCAO, PAP‐1 dose‐dependently reduced infarct area, improved neurological deficit score, and reduced brain levels of IL‐1β and IFN‐γ without affecting IL‐10 and brain‐derived nerve growth factor (BDNF) levels or inhibiting ongoing phagocytosis. The beneficial effects on infarct area and neurological deficit score were reproduced in rats providing confirmation in a second species. Interpretation Our findings suggest that Kv1.3 constitutes a promising therapeutic target for preferentially inhibiting “M1‐like” inflammatory microglia/macrophage functions in ischemic stroke.
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Affiliation(s)
- Yi-Je Chen
- Department of Pharmacology University of California Davis 95616 California
| | - Hai M Nguyen
- Department of Pharmacology University of California Davis 95616 California
| | - Izumi Maezawa
- Department of Pathology and Laboratory Medicine University of California Davis, Sacramento 95817 California.,M.I.N.D. Institute University of California Davis 95817 California
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine University of California Davis, Sacramento 95817 California.,M.I.N.D. Institute University of California Davis 95817 California
| | - Heike Wulff
- Department of Pharmacology University of California Davis 95616 California
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35
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Tai LM, Balu D, Avila-Munoz E, Abdullah L, Thomas R, Collins N, Valencia-Olvera AC, LaDu MJ. EFAD transgenic mice as a human APOE relevant preclinical model of Alzheimer's disease. J Lipid Res 2017; 58:1733-1755. [PMID: 28389477 PMCID: PMC5580905 DOI: 10.1194/jlr.r076315] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/06/2017] [Indexed: 01/12/2023] Open
Abstract
Identified in 1993, APOE4 is the greatest genetic risk factor for sporadic Alzheimer's disease (AD), increasing risk up to 15-fold compared with APOE3, with APOE2 decreasing AD risk. However, the functional effects of APOE4 on AD pathology remain unclear and, in some cases, controversial. In vivo progress to understand how the human (h)-APOE genotypes affect AD pathology has been limited by the lack of a tractable familial AD-transgenic (FAD-Tg) mouse model expressing h-APOE rather than mouse (m)-APOE. The disparity between m- and h-apoE is relevant for virtually every AD-relevant pathway, including amyloid-β (Aβ) deposition and clearance, neuroinflammation, tau pathology, neural plasticity and cerebrovascular deficits. EFAD mice were designed as a temporally useful preclinical FAD-Tg-mouse model expressing the h-APOE genotypes for identifying mechanisms underlying APOE-modulated symptoms of AD pathology. From their first description in 2012, EFAD mice have enabled critical basic and therapeutic research. Here we review insights gleaned from the EFAD mice and summarize future directions.
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Affiliation(s)
- Leon M Tai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Deebika Balu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Evangelina Avila-Munoz
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | | | - Riya Thomas
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Nicole Collins
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | | | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612.
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36
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Postupna N, Latimer CS, Larson EB, Sherfield E, Paladin J, Shively CA, Jorgensen MJ, Andrews RN, Kaplan JR, Crane PK, Montine KS, Craft S, Keene CD, Montine TJ. Human Striatal Dopaminergic and Regional Serotonergic Synaptic Degeneration with Lewy Body Disease and Inheritance of APOE ε4. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:884-895. [PMID: 28212814 DOI: 10.1016/j.ajpath.2016.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 12/10/2016] [Accepted: 12/20/2016] [Indexed: 01/22/2023]
Abstract
Cognitive impairment in older individuals is a complex trait that in population-based studies most commonly derives from an individually varying mixture of Alzheimer disease, Lewy body disease, and vascular brain injury. We investigated the molecular composition of synaptic particles from three sources: consecutive rapid autopsy brains from the Adult Changes in Thought Study, a population-based cohort; four aged nonhuman primate brains optimally processed for molecular investigation; and targeted replacement transgenic mice homozygous for APOE ε4. Our major goal was to characterize the molecular composition of human synaptic particles in regions of striatum and prefrontal cortex. We performed flow cytometry to measure six markers of synaptic subtypes, as well as amyloid β 42 and paired helical filament tau. Our results showed selective degeneration of dopaminergic terminals throughout the striatum in individuals with Lewy body disease, and serotonergic degeneration in human ventromedial caudate nucleus from individuals with an APOE ε4 allele. Similar results were seen in mouse caudate nucleus homozygous for APOE ε4 via targeted replacement. Together, extension of these clinical, pathologic, and genetic associations from tissue to the synaptic compartment of cerebral cortex and striatum strongly supports our approach for accurately observing the molecular composition of human synapses by flow cytometry.
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Affiliation(s)
- Nadia Postupna
- Department of Pathology, University of Washington, Seattle, Washington
| | - Caitlin S Latimer
- Department of Pathology, University of Washington, Seattle, Washington
| | - Eric B Larson
- Group Health Research Institute, Seattle, Washington
| | - Emily Sherfield
- Department of Pathology, University of Washington, Seattle, Washington
| | - Julie Paladin
- Department of Pathology, University of Washington, Seattle, Washington
| | - Carol A Shively
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Matthew J Jorgensen
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Rachel N Andrews
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Jay R Kaplan
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Paul K Crane
- Department of Medicine, University of Washington, Seattle, Washington
| | | | - Suzanne Craft
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - C Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington
| | - Thomas J Montine
- Department of Pathology, University of Washington, Seattle, Washington.
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37
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Chen YJ, Nguyen HM, Maezawa I, Grössinger EM, Garing AL, Köhler R, Jin LW, Wulff H. The potassium channel KCa3.1 constitutes a pharmacological target for neuroinflammation associated with ischemia/reperfusion stroke. J Cereb Blood Flow Metab 2016; 36:2146-2161. [PMID: 26661208 PMCID: PMC5363659 DOI: 10.1177/0271678x15611434] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/25/2015] [Accepted: 09/13/2015] [Indexed: 11/16/2022]
Abstract
Activated microglia/macrophages significantly contribute to the secondary inflammatory damage in ischemic stroke. Cultured neonatal microglia express the K+ channels Kv1.3 and KCa3.1, both of which have been reported to be involved in microglia-mediated neuronal killing, oxidative burst and cytokine production. However, it is questionable whether neonatal cultures accurately reflect the K+ channel expression of activated microglia in the adult brain. We here subjected mice to middle cerebral artery occlusion with eight days of reperfusion and patch-clamped acutely isolated microglia/macrophages. Microglia from the infarcted area exhibited higher densities of K+ currents with the biophysical and pharmacological properties of Kv1.3, KCa3.1 and Kir2.1 than microglia from non-infarcted control brains. Similarly, immunohistochemistry on human infarcts showed strong Kv1.3 and KCa3.1 immunoreactivity on activated microglia/macrophages. We next investigated the effect of genetic deletion and pharmacological blockade of KCa3.1 in reversible middle cerebral artery occlusion. KCa3.1-/- mice and wild-type mice treated with the KCa3.1 blocker TRAM-34 exhibited significantly smaller infarct areas on day-8 after middle cerebral artery occlusion and improved neurological deficit. Both manipulations reduced microglia/macrophage activation and brain cytokine levels. Our findings suggest KCa3.1 as a pharmacological target for ischemic stroke. Of potential, clinical relevance is that KCa3.1 blockade is still effective when initiated 12 h after the insult.
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Affiliation(s)
- Yi-Je Chen
- Department of Pharmacology, University of California, Davis, CA, USA.,Microsurgery Core, University of California, Davis, CA, USA
| | - Hai M Nguyen
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Izumi Maezawa
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA, USA.,M.I.N.D. Institute, University of California, Davis, Sacramento, CA, USA
| | - Eva M Grössinger
- Department of Pharmacology, University of California, Davis, CA, USA
| | - April L Garing
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Ralf Köhler
- Aragon Institute of Health Sciences/IIS and ARAID, Zaragoza, Spain
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA, USA.,M.I.N.D. Institute, University of California, Davis, Sacramento, CA, USA
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, CA, USA
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38
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Decreased IL-8 levels in CSF and serum of AD patients and negative correlation of MMSE and IL-1β. BMC Neurol 2016; 16:185. [PMID: 27671345 PMCID: PMC5037590 DOI: 10.1186/s12883-016-0707-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/20/2016] [Indexed: 01/22/2023] Open
Abstract
Background It is widely accepted that neuroinflammatory processes play an important role in the pathogenesis of Alzheimer’s disease (AD) and high levels of cytokines and chemokines are detected around Aβ plaques. Methods As neuroinflammation is involved in the development and progression of AD, we measured the pro-inflammatory cytokines interleukin 1β (IL-1β), IL-8 and tumor necrosis factor α (TNF-α) in serum and cerebrospinal fluid (CSF) samples from 45 AD patients and 53 age-matched control subjects using a highly sensitive multiplex electrochemiluminescence assay. To address the association with disease progression we correlated cognitive status with cytokine levels. Results CSF as well as serum IL-8 levels were found to be significantly lower in AD patients than in controls (p = 0.02). A statistically significant inverse correlation was observed between the CSF level of IL-1β and the MMSE score (rs = -0.03, p = 0.02). We therefore stratified the AD patients by their MMSE scores into three equal groups and found that in the AD group with the most severe cognitive impairment CSF-IL-1β was significantly increased compared to age-matched controls (p < 0.05), whereas in the other investigated groups the increase was not statistically significant. Conclusion Our results confirm data suggesting that cytokine alterations are involved in AD pathogenesis and may be helpful as a biomarker for monitoring disease progression. Electronic supplementary material The online version of this article (doi:10.1186/s12883-016-0707-z) contains supplementary material, which is available to authorized users.
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39
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Caberlotto L, Marchetti L, Lauria M, Scotti M, Parolo S. Integration of transcriptomic and genomic data suggests candidate mechanisms for APOE4-mediated pathogenic action in Alzheimer's disease. Sci Rep 2016; 6:32583. [PMID: 27585646 PMCID: PMC5009326 DOI: 10.1038/srep32583] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/10/2016] [Indexed: 02/07/2023] Open
Abstract
Among the genetic factors known to increase the risk of late onset Alzheimer’s diseases (AD), the presence of the apolipoproteine e4 (APOE4) allele has been recognized as the one with the strongest effect. However, despite decades of research, the pathogenic role of APOE4 in Alzheimer’s disease has not been clearly elucidated yet. In order to investigate the pathogenic action of APOE4, we applied a systems biology approach to the analysis of transcriptomic and genomic data of APOE44 vs. APOE33 allele carriers affected by Alzheimer’s disease. Network analysis combined with a novel technique for biomarker computation allowed the identification of an alteration in aging-associated processes such as inflammation, oxidative stress and metabolic pathways, indicating that APOE4 possibly accelerates pathological processes physiologically induced by aging. Subsequent integration with genomic data indicates that the Notch pathway could be the nodal molecular mechanism altered in APOE44 allele carriers with Alzheimer’s disease. Interestingly, PSEN1 and APP, genes whose mutation are known to be linked to early onset Alzheimer’s disease, are closely linked to this pathway. In conclusion, APOE4 role on inflammation and oxidation through the Notch signaling pathway could be crucial in elucidating the risk factors of Alzheimer’s disease.
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Affiliation(s)
- Laura Caberlotto
- The Microsoft Research, University of Trento Centre for Computational Systems Biology (COSBI), Piazza Manifattura 1, 38068, Rovereto, Italy
| | - Luca Marchetti
- The Microsoft Research, University of Trento Centre for Computational Systems Biology (COSBI), Piazza Manifattura 1, 38068, Rovereto, Italy
| | - Mario Lauria
- The Microsoft Research, University of Trento Centre for Computational Systems Biology (COSBI), Piazza Manifattura 1, 38068, Rovereto, Italy
| | - Marco Scotti
- The Microsoft Research, University of Trento Centre for Computational Systems Biology (COSBI), Piazza Manifattura 1, 38068, Rovereto, Italy.,GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Silvia Parolo
- The Microsoft Research, University of Trento Centre for Computational Systems Biology (COSBI), Piazza Manifattura 1, 38068, Rovereto, Italy
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40
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Dose J, Huebbe P, Nebel A, Rimbach G. APOE genotype and stress response - a mini review. Lipids Health Dis 2016; 15:121. [PMID: 27457486 PMCID: PMC4960866 DOI: 10.1186/s12944-016-0288-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/12/2016] [Indexed: 12/31/2022] Open
Abstract
The APOE gene is one of currently only two genes that have consistently been associated with longevity. Apolipoprotein E (APOE) is a plasma protein which plays an important role in lipid and lipoprotein metabolism. In humans, there are three major APOE isoforms, designated APOE2, APOE3, and APOE4. Of these three isoforms, APOE3 is most common while APOE4 was shown to be associated with age-related diseases, including cardiovascular and Alzheimer’s disease, and therefore an increased mortality risk with advanced age. Evidence accumulates, showing that oxidative stress and, correspondingly, mitochondrial function is affected in an APOE isoform-dependent manner. Accordingly, several stress response pathways implicated in the aging process, including the endoplasmic reticulum stress response and immune function, appear to be influenced by the APOE genotype. The investigation and development of treatment strategies targeting APOE4 have not resolved any therapeutic yet that could be entirely recommended. This mini-review provides an overview on the state of research concerning the impact of the APOE genotype on stress response-related processes, emphasizing the strong interconnection between mitochondrial function, endoplasmic reticulum stress and the immune response. Furthermore, this review addresses potential treatment strategies and associated pitfalls as well as lifestyle interventions that could benefit people with an at risk APOE4 genotype.
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Affiliation(s)
- Janina Dose
- Institute of Human Nutrition and Food Science, Kiel University, Hermann-Rodewald-Str. 6, D-24118, Kiel, Germany. .,Institute of Clinical Molecular Biology, Kiel University, Schittenhelmstr. 12, D-24105, Kiel, Germany.
| | - Patricia Huebbe
- Institute of Human Nutrition and Food Science, Kiel University, Hermann-Rodewald-Str. 6, D-24118, Kiel, Germany
| | - Almut Nebel
- Institute of Clinical Molecular Biology, Kiel University, Schittenhelmstr. 12, D-24105, Kiel, Germany
| | - Gerald Rimbach
- Institute of Human Nutrition and Food Science, Kiel University, Hermann-Rodewald-Str. 6, D-24118, Kiel, Germany
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41
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Ghura S, Tai L, Zhao M, Collins N, Che CT, Warpeha KM, LaDu MJ. Arabidopsis thaliana extracts optimized for polyphenols production as potential therapeutics for the APOE-modulated neuroinflammation characteristic of Alzheimer's disease in vitro. Sci Rep 2016; 6:29364. [PMID: 27383500 PMCID: PMC4935988 DOI: 10.1038/srep29364] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/17/2016] [Indexed: 01/14/2023] Open
Abstract
Although the cause of Alzheimer's disease (AD) is unknown, glial-induced neuroinflammation is an early symptom. Familial AD is caused by increases in amyloid-beta (Aβ) peptide, particularly soluble oligomeric (oAβ), considered a proximal neurotoxin and neuroinflammatory stimuli. APOE4, a naturally occurring genotype of APOE, is the greatest genetic risk factor for AD; increasing risk up to 12-fold compared to APOE3 and APOE2. oAβ-induced neuroinflammation is greater with APOE4 compared to APOE3 and APOE2. As sinapates and flavonoids have anti-inflammatory properties, a protocol was developed for optimizing polyphenol production in seedlings of Arabidopsis thaliana (A. thaliana). Three mutants (cop1, prn1, xpf3) were identified, and the extracts treated with liver microsomes to mimic physiological metabolism, with HPLC and MS performed on the resulting metabolites for peak identification. These extracts were used to treat primary glial cells isolated from human APOE-targeted-replacement (APOE-TR) and APOE-knock-out (KO) mice, with neuroinflammation induced by lipopolysaccharide (LPS) or oAβ. The dose-response data for TNFα secretion demonstrate the followed the order: APOE-KO > APOE4 > APOE3 > APOE2, with xpf3 the most effective anti-neuroinflammatory across APOE genotypes. Thus, the plant-based approach described herein may be particularly valuable in treating the APOE4-induced neuroinflammatory component of AD risk.
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Affiliation(s)
- Shivesh Ghura
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Leon Tai
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Ming Zhao
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Nicole Collins
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Chun-Tao Che
- Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Katherine M Warpeha
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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42
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Dá Mesquita S, Ferreira AC, Sousa JC, Correia-Neves M, Sousa N, Marques F. Insights on the pathophysiology of Alzheimer's disease: The crosstalk between amyloid pathology, neuroinflammation and the peripheral immune system. Neurosci Biobehav Rev 2016; 68:547-562. [PMID: 27328788 DOI: 10.1016/j.neubiorev.2016.06.014] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 06/09/2016] [Accepted: 06/14/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, whose prevalence is growing along with the increased life expectancy. Although the accumulation and deposition of amyloid beta (Aβ) peptides in the brain is viewed as one of the pathological hallmarks of AD and underlies, at least in part, brain cell dysfunction and behavior alterations, the etiology of this neurodegenerative disease is still poorly understood. Noticeably, increased amyloid load is accompanied by marked inflammatory alterations, both at the level of the brain parenchyma and at the barriers of the brain. However, it is debatable whether the neuroinflammation observed in aging and in AD, together with alterations in the peripheral immune system, are responsible for increased amyloidogenesis, decreased clearance of Aβ out of the brain and/or the marked deficits in memory and cognition manifested by AD patients. Herein, we scrutinize some important traits of the pathophysiology of aging and AD, focusing on the interplay between the amyloidogenic pathway, neuroinflammation and the peripheral immune system.
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Affiliation(s)
- Sandro Dá Mesquita
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Ana Catarina Ferreira
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Margarida Correia-Neves
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimaraes, Portugal.
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43
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Integrated Stress Response: Connecting ApoE4 to Memory Impairment in Alzheimer's Disease. J Neurosci 2016; 36:1053-5. [PMID: 26818496 DOI: 10.1523/jneurosci.4110-15.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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44
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α-Mangostin Inhibits α-Synuclein-Induced Microglial Neuroinflammation and Neurotoxicity. Cell Mol Neurobiol 2016; 36:811-20. [PMID: 27002719 PMCID: PMC4894924 DOI: 10.1007/s10571-015-0264-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 08/27/2015] [Indexed: 01/13/2023]
Abstract
Microglia-mediated neuroinflammation induced by α-synuclein in the substantianigra likely either initiates or aggravates nigral neuro degeneration in Parkinson’s disease (PD). We aimed to explore the effects of α-mangostin (α-M), a polyphenolicxanthone derivative from mangosteen on α-synuclein-stimulated DA neurodegeneration. Primary microglia, mesencephalic neuron, mesencephalic neuron-glianeuronal cultures, and transwell co-cultures were prepared separately. Liquid scintillation counting was used to determine the radioactivity in DA uptake. Enzyme-linked immunosorbent assay (ELISA) was performed in the IL-1β, IL-6, and TNF-α assay. The expression of proteins was analyzed by Western blot. α-M inhibited the increased levels of pro-inflammatory cytokines, NO, and ROS in α-synuclein-stimulated primary microglia. Mechanistic study revealed that α-M functioned by inhibition of nuclear factor kappa B (NF-κB) and NADPH oxidase. Further, α-M protected α-synuclein-induced microglial and direct neurotoxicity. Although detailed mechanisms remain to be defined, our observations suggest a potential compound, which inhibits microglial activation induced by α-synuclein by targeting NADPH oxidase, might be a therapeutic possibility in preventing PD progression.
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45
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Genetic and Transcriptomic Profiles of Inflammation in Neurodegenerative Diseases: Alzheimer, Parkinson, Creutzfeldt-Jakob and Tauopathies. Int J Mol Sci 2016; 17:206. [PMID: 26861289 PMCID: PMC4783939 DOI: 10.3390/ijms17020206] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 01/02/2023] Open
Abstract
Polymorphisms in certain inflammatory-related genes have been identified as putative differential risk factors of neurodegenerative diseases with abnormal protein aggregates, such as sporadic Alzheimer’s disease (AD) and sporadic Parkinson’s disease (sPD). Gene expression studies of cytokines and mediators of the immune response have been made in post-mortem human brain samples in AD, sPD, sporadic Creutzfeldt-Jakob disease (sCJD) subtypes MM1 and VV2, Pick’s disease (PiD), progressive supranuclear palsy (PSP) and frontotemporal lobar degeneration linked to mutation P301L in MAPT Frontotemporal lobar degeneration-tau (FTLD-tau). The studies have disclosed variable gene regulation which is: (1) disease-dependent in the frontal cortex area 8 in AD, sPD, sCJD MM1 and VV2, PiD, PSP and FTLD-tau; (2) region-dependent as seen when comparing the entorhinal cortex, orbitofrontal cortex, and frontal cortex area 8 (FC) in AD; the substantia nigra, putamen, FC, and angular gyrus in PD, as well as the FC and cerebellum in sCJD; (3) genotype-dependent as seen considering sCJD MM1 and VV2; and (4) stage-dependent as seen in AD at different stages of disease progression. These observations show that regulation of inflammation is much more complicated and diverse than currently understood, and that new therapeutic approaches must be designed in order to selectively act on specific targets in particular diseases and at different time points of disease progression.
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46
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Moser VA, Pike CJ. Obesity and sex interact in the regulation of Alzheimer's disease. Neurosci Biobehav Rev 2015; 67:102-18. [PMID: 26708713 DOI: 10.1016/j.neubiorev.2015.08.021] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/01/2015] [Accepted: 08/03/2015] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which a number of genetic, environmental, and lifestyle risk factors have been identified. A significant modifiable risk factor is obesity in mid-life. Interestingly, both obesity and AD exhibit sex differences and are regulated by sex steroid hormones. Accumulating evidence suggests interactions between obesity and sex in regulation of AD risk, although the pathways underlying this relationship are unclear. Inflammation and the E4 allele of apolipoprotein E have been identified as independent risk factors for AD and both interact with obesity and sex steroid hormones. We review the individual and cooperative effects of obesity and sex on development of AD and examine the potential contributions of apolipoprotein E, inflammation, and their interactions to this relationship.
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Affiliation(s)
- V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA.
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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47
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Mhatre SD, Tsai CA, Rubin AJ, James ML, Andreasson KI. Microglial malfunction: the third rail in the development of Alzheimer's disease. Trends Neurosci 2015; 38:621-636. [PMID: 26442696 PMCID: PMC4670239 DOI: 10.1016/j.tins.2015.08.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 12/23/2022]
Abstract
Studies of Alzheimer's disease (AD) have predominantly focused on two major pathologies: amyloid-β (Aβ) and hyperphosphorylated tau. These misfolded proteins can accumulate asymptomatically in distinct regions over decades. However, significant Aβ accumulation can be seen in individuals who do not develop dementia, and tau pathology limited to the transentorhinal cortex, which can appear early in adulthood, is usually clinically silent. Thus, an interaction between these pathologies appears to be necessary to initiate and propel disease forward to widespread circuits. Recent multidisciplinary findings strongly suggest that the third factor required for disease progression is an aberrant microglial immune response. This response may initially be beneficial; however, a maladaptive microglial response eventually develops, fueling a feed-forward spread of tau and Aβ pathology.
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Affiliation(s)
- Siddhita D Mhatre
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Stanford Neurosciences Institute, Stanford, CA, USA
| | - Connie A Tsai
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Stanford Neurosciences Institute, Stanford, CA, USA; Neurosciences Graduate Program, Stanford University, Stanford, CA, USA
| | - Amanda J Rubin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Stanford Neurosciences Institute, Stanford, CA, USA; Neurosciences Graduate Program, Stanford University, Stanford, CA, USA
| | - Michelle L James
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Katrin I Andreasson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Stanford Neurosciences Institute, Stanford, CA, USA.
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48
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Gamba P, Testa G, Gargiulo S, Staurenghi E, Poli G, Leonarduzzi G. Oxidized cholesterol as the driving force behind the development of Alzheimer's disease. Front Aging Neurosci 2015; 7:119. [PMID: 26150787 PMCID: PMC4473000 DOI: 10.3389/fnagi.2015.00119] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD), the most common neurodegenerative disorder associated with dementia, is typified by the pathological accumulation of amyloid Aβ peptides and neurofibrillary tangles (NFT) within the brain. Considerable evidence indicates that many events contribute to AD progression, including oxidative stress, inflammation, and altered cholesterol metabolism. The brain’s high lipid content makes it particularly vulnerable to oxidative species, with the consequent enhancement of lipid peroxidation and cholesterol oxidation, and the subsequent formation of end products, mainly 4-hydroxynonenal and oxysterols, respectively from the two processes. The chronic inflammatory events observed in the AD brain include activation of microglia and astrocytes, together with enhancement of inflammatory molecule and free radical release. Along with glial cells, neurons themselves have been found to contribute to neuroinflammation in the AD brain, by serving as sources of inflammatory mediators. Oxidative stress is intimately associated with neuroinflammation, and a vicious circle has been found to connect oxidative stress and inflammation in AD. Alongside oxidative stress and inflammation, altered cholesterol metabolism and hypercholesterolemia also significantly contribute to neuronal damage and to progression of AD. Increasing evidence is now consolidating the hypothesis that oxidized cholesterol is the driving force behind the development of AD, and that oxysterols are the link connecting the disease to altered cholesterol metabolism in the brain and hypercholesterolemia; this is because of the ability of oxysterols, unlike cholesterol, to cross the blood brain barrier (BBB). The key role of oxysterols in AD pathogenesis has been strongly supported by research pointing to their involvement in modulating neuroinflammation, Aβ accumulation, and cell death. This review highlights the key role played by cholesterol and oxysterols in the brain in AD pathogenesis.
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Affiliation(s)
- Paola Gamba
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Testa
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Simona Gargiulo
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Erica Staurenghi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
| | - Gabriella Leonarduzzi
- Department of Clinical and Biological Sciences, School of Medicine, University of Turin Orbassano, Torino, Italy
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49
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Tai LM, Ghura S, Koster KP, Liakaite V, Maienschein‐Cline M, Kanabar P, Collins N, Ben‐Aissa M, Lei AZ, Bahroos N, Green SJ, Hendrickson B, Van Eldik LJ, LaDu MJ. APOE-modulated Aβ-induced neuroinflammation in Alzheimer's disease: current landscape, novel data, and future perspective. J Neurochem 2015; 133:465-88. [PMID: 25689586 PMCID: PMC4400246 DOI: 10.1111/jnc.13072] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 01/12/2023]
Abstract
Chronic glial activation and neuroinflammation induced by the amyloid-β peptide (Aβ) contribute to Alzheimer's disease (AD) pathology. APOE4 is the greatest AD-genetic risk factor; increasing risk up to 12-fold compared to APOE3, with APOE4-specific neuroinflammation an important component of this risk. This editorial review discusses the role of APOE in inflammation and AD, via a literature review, presentation of novel data on Aβ-induced neuroinflammation, and discussion of future research directions. The complexity of chronic neuroinflammation, including multiple detrimental and beneficial effects occurring in a temporal and cell-specific manner, has resulted in conflicting functional data for virtually every inflammatory mediator. Defining a neuroinflammatory phenotype (NIP) is one way to address this issue, focusing on profiling the changes in inflammatory mediator expression during disease progression. Although many studies have shown that APOE4 induces a detrimental NIP in peripheral inflammation and Aβ-independent neuroinflammation, data for APOE-modulated Aβ-induced neuroinflammation are surprisingly limited. We present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (toll-like receptor 4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways. To ultimately develop APOE genotype-specific therapeutics, it is critical that future studies define the dynamic NIP profile and pathways that underlie APOE-modulated chronic neuroinflammation. In this editorial review, we present data supporting the hypothesis that impaired apoE4 function modulates Aβ-induced effects on inflammatory receptor signaling, including amplification of detrimental (TLR4-p38α) and suppression of beneficial (IL-4R-nuclear receptor) pathways, resulting in an adverse NIP that causes neuronal dysfunction. NIP, Neuroinflammatory phenotype; P.I., pro-inflammatory; A.I., anti-inflammatory.
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Affiliation(s)
- Leon M. Tai
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Shivesh Ghura
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Kevin P. Koster
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | | | | | - Pinal Kanabar
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | - Nicole Collins
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Manel Ben‐Aissa
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
| | - Arden Zhengdeng Lei
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | - Neil Bahroos
- UIC Center for Research Informatics University of IllinoisChicagoIllinoisUSA
| | | | - Bill Hendrickson
- UIC Research Resources CenterUniversity of IllinoisChicagoIllinoisUSA
| | | | - Mary Jo LaDu
- Department of Anatomy and Cell BiologyUniversity of IllinoisChicagoIllinoisUSA
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Li X, Montine KS, Keene CD, Montine TJ. Different mechanisms of apolipoprotein E isoform-dependent modulation of prostaglandin E2 production and triggering receptor expressed on myeloid cells 2 (TREM2) expression after innate immune activation of microglia. FASEB J 2015; 29:1754-62. [PMID: 25593125 DOI: 10.1096/fj.14-262683] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/15/2014] [Indexed: 01/14/2023]
Abstract
Several lines of evidence support immune response in brain as a mechanism of injury in Alzheimer disease (AD). Moreover, immune activation is heightened in apolipoprotein E (APOE) ε4 carriers; inhibitors of prostaglandin (PG) synthesis show a partially protective effect on AD risk from APOE ε4; and genetic variants in triggering receptor expressed on myeloid cells 2 (TREM2) are a rare but potent risk for AD. We tested the hypothesis that APOE ε4 inheritance modulates both the PGE2 pathway and TREM2 expression using primary murine microglia from targeted replacement (TR) APOE3/3 and APOE4/4 mice. Microglial cyclooxygenase-2, microsomal PGE synthase, and PGE2 expression were increased 2- to 25-fold in both genotypes by TLR activators; however, this induction was significantly (P < 0.01) greater in TR APOE4/4 microglia with TLR3 and TLR4 activators. Microglial TREM2 expression was reduced approximately 85% by all TLR activators; this reduction was approximately one-third greater in microglia from TR APOE4/4 mice. Importantly, both receptor-associated protein and a nuclear factor κ-light-chain-enhancer inhibitor blocked TR APOE4/4-dependent effects on the PGE2 pathway but not on TREM2 expression. These data demonstrate complementary, but mechanistically distinct, regulation of pro- and anti-inflammatory mediators in TR APOE4/4 murine microglia that yields a more proinflammatory state than with TR APOE3/3.
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Affiliation(s)
- Xianwu Li
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Kathleen S Montine
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - C Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Thomas J Montine
- Department of Pathology, University of Washington, Seattle, Washington, USA
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