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Parra Bravo C, Naguib SA, Gan L. Cellular and pathological functions of tau. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00753-9. [PMID: 39014245 DOI: 10.1038/s41580-024-00753-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2024] [Indexed: 07/18/2024]
Abstract
Tau protein is involved in various cellular processes, including having a canonical role in binding and stabilization of microtubules in neurons. Tauopathies are neurodegenerative diseases marked by the abnormal accumulation of tau protein aggregates in neurons, as seen, for example, in conditions such as frontotemporal dementia and Alzheimer disease. Mutations in tau coding regions or that disrupt tau mRNA splicing, tau post-translational modifications and cellular stress factors (such as oxidative stress and inflammation) increase the tendency of tau to aggregate and interfere with its clearance. Pathological tau is strongly implicated in the progression of neurodegenerative diseases, and the propagation of tau aggregates is associated with disease severity. Recent technological advancements, including cryo-electron microscopy and disease models derived from human induced pluripotent stem cells, have increased our understanding of tau-related pathology in neurodegenerative conditions. Substantial progress has been made in deciphering tau aggregate structures and the molecular mechanisms that underlie protein aggregation and toxicity. In this Review, we discuss recent insights into the diverse cellular functions of tau and the pathology of tau inclusions and explore the potential for therapeutic interventions.
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Affiliation(s)
- Celeste Parra Bravo
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Sarah A Naguib
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Li Gan
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
- Neuroscience Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA.
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Yan H, Wang W, Cui T, Shao Y, Li M, Fang L, Feng L. Advances in the Understanding of the Correlation Between Neuroinflammation and Microglia in Alzheimer's Disease. Immunotargets Ther 2024; 13:287-304. [PMID: 38881647 PMCID: PMC11180466 DOI: 10.2147/itt.s455881] [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: 03/14/2024] [Accepted: 06/05/2024] [Indexed: 06/18/2024] Open
Abstract
Alzheimer's disease (AD) is a fatal neurodegenerative disease with a subtle and progressive onset and is the most common type of dementia. However, its etiology and pathogenesis have not yet been fully elucidated. The common pathological manifestations of AD include extraneuronal β-amyloid deposition (Aβ), intraneuronal tau protein phosphorylation leading to the formation of 'neurofibrillary tangles' (NFTs), neuroinflammation, progressive loss of brain neurons/synapses, and glucose metabolism disorders. Current treatment approaches for AD primarily focus on the 'Aβ cascade hypothesis and abnormal aggregation of hyperphosphorylation of tau proteins', but have shown limited efficacy. Therefore, there is an ongoing need to identify more effective treatment targets for AD. The central nervous system (CNS) inflammatory response plays a key role in the occurrence and development of AD. Neuroinflammation is an immune response activated by glial cells in the CNS that usually occurs in response to stimuli such as nerve injury, infection and toxins or in response to autoimmunity. Neuroinflammation ranks as the third most prominent pathological feature in AD, following Aβ and NFTs. In recent years, the focus on the role of neuroinflammation and microglia in AD has increased due to the advancements in genome-wide association studies (GWAS) and sequencing technology. Furthermore, research has validated the pivotal role of microglia-mediated neuroinflammation in the progression of AD. Therefore, this article reviews the latest research progress on the role of neuroinflammation triggered by microglia in AD in recent years, aiming to provide a new theoretical basis for further exploring the role of neuroinflammation in the process of AD occurrence and development.
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Affiliation(s)
- Huiying Yan
- Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People's Republic of China
| | - Wei Wang
- Department of Intensive Care Unit, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, People's Republic of China
| | - Tingting Cui
- Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People's Republic of China
| | - Yanxin Shao
- Department of Neurology, The Second Affiliated Hospital of Shandong First Medical University, Taian, People's Republic of China
| | - Mingquan Li
- Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People's Republic of China
| | - Limei Fang
- Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People's Republic of China
| | - Lina Feng
- Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People's Republic of China
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Lepiarz-Raba I, Hidayat T, Hannan AJ, Jawaid A. Potential Alzheimer's disease drug targets identified through microglial biology research. Expert Opin Drug Discov 2024; 19:587-602. [PMID: 38590098 DOI: 10.1080/17460441.2024.2335210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/22/2024] [Indexed: 04/10/2024]
Abstract
INTRODUCTION Microglia, the primary immune cells in the brain, play multifaceted roles in Alzheimer's disease (AD). Microglia can potentially mitigate the pathological progression of AD by clearing amyloid beta (Aβ) deposits in the brain and through neurotrophic support. In contrast, disproportionate activation of microglial pro-inflammatory pathways, as well as excessive elimination of healthy synapses, can exacerbate neurodegeneration in AD. The challenge, therefore, lies in discerning the precise regulation of the contrasting microglial properties to harness their therapeutic potential in AD. AREAS COVERED This review examines the evidence relevant to the disease-modifying effects of microglial manipulators in AD preclinical models. The deleterious pro-inflammatory effects of microglia in AD can be ameliorated via direct suppression or indirectly through metabolic manipulation, epigenetic targeting, and modulation of the gut-brain axis. Furthermore, microglial clearance of Aβ deposits in AD can be enhanced via strategically targeting microglial membrane receptors, lysosomal functions, and metabolism. EXPERT OPINION Given the intricate and diverse nature of microglial responses throughout the course of AD, therapeutic interventions directed at microglia warrant a tactical approach. This could entail employing therapeutic regimens, which concomitantly suppress pro-inflammatory microglial responses while selectively enhancing Aβ phagocytosis.
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Affiliation(s)
- Izabela Lepiarz-Raba
- Laboratory for Translational Research in Exposures and Neuropsychiatric Disorders (TREND), Braincity: Center of Excellence for Neural Plasticity and Brain Disorders, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Taufik Hidayat
- Laboratory for Translational Research in Exposures and Neuropsychiatric Disorders (TREND), Braincity: Center of Excellence for Neural Plasticity and Brain Disorders, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Australia
| | - Ali Jawaid
- Laboratory for Translational Research in Exposures and Neuropsychiatric Disorders (TREND), Braincity: Center of Excellence for Neural Plasticity and Brain Disorders, Nencki Institute of Experimental Biology, Warsaw, Poland
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Jauregui C, Blanco-Luquin I, Macías M, Roldan M, Caballero C, Pagola I, Mendioroz M, Jericó I. Exploring the Disease-Associated Microglia State in Amyotrophic Lateral Sclerosis. Biomedicines 2023; 11:2994. [PMID: 38001994 PMCID: PMC10669775 DOI: 10.3390/biomedicines11112994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Neuroinflammation, and specifically microglia, plays an important but not-yet well-understood role in the pathophysiology of amyotrophic lateral sclerosis (ALS), constituting a potential therapeutic target for the disease. Recent studies have described the involvement of different microglial transcriptional patterns throughout neurodegenerative processes, identifying a new state of microglia: disease-associated microglia (DAM). The aim of this study is to investigate expression patterns of microglial-related genes in ALS spinal cord. METHODS We analyzed mRNA expression levels via RT-qPCR of several microglia-related genes in their homeostatic and DAM state in postmortem tissue (anterior horn of the spinal cord) from 20 subjects with ALS-TDP43 and 19 controls donors from the Navarrabiomed Biobank. RESULTS The expression levels of TREM2, MS4A, CD33, APOE and TYROBP were found to be elevated in the spinal cord from ALS subjects versus controls (p-value < 0.05). However, no statistically significant gene expression differences were observed for TMEM119, SPP1 and LPL. CONCLUSIONS This study suggests that a DAM-mediated inflammatory response is present in ALS, and TREM2 plays a significant role in immune function of microglia. It also supports the role of C33 and MS4A in the physiopathology of ALS.
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Affiliation(s)
- Carlota Jauregui
- Neurology Department, Hospital Universitario de Navarra (HUN), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Idoia Blanco-Luquin
- Neuroepigenetics Laboratory, Navarrabiomed, Universidad Pública de Navarra (UPNA), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Mónica Macías
- Neuroepigenetics Laboratory, Navarrabiomed, Universidad Pública de Navarra (UPNA), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Miren Roldan
- Neuroepigenetics Laboratory, Navarrabiomed, Universidad Pública de Navarra (UPNA), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Cristina Caballero
- Department of Pathology, Hospital Universitario de Navarra (HUN), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Inma Pagola
- Neurology Department, Hospital Universitario de Navarra (HUN), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
- Neuromuscular and Neuron Motor Diseases Research Group, Navarrabiomed, IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Maite Mendioroz
- Neurology Department, Hospital Universitario de Navarra (HUN), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
- Neuroepigenetics Laboratory, Navarrabiomed, Universidad Pública de Navarra (UPNA), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
| | - Ivonne Jericó
- Neurology Department, Hospital Universitario de Navarra (HUN), IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
- Neuromuscular and Neuron Motor Diseases Research Group, Navarrabiomed, IdiSNA (Navarra Institute of Health Research), 31008 Pamplona, Spain
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Weaver DF. Druggable targets for the immunopathy of Alzheimer's disease. RSC Med Chem 2023; 14:1645-1661. [PMID: 37731705 PMCID: PMC10507808 DOI: 10.1039/d3md00096f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 06/21/2023] [Indexed: 09/22/2023] Open
Abstract
Alzheimer's disease (AD) is one of the leading threats to the health and socioeconomic well-being of humankind. Though research to develop disease modifying therapies for AD has traditionally focussed on the misfolding and aggregation of proteins, this approach has failed to yield a definitively curative agent. Accordingly, the search for additional or alternative approaches is a medicinal chemistry priority. Dysfunction of the brain's neuroimmune-neuroinflammation axis has emerged as a leading contender. Neuroimmunity however is mechanistically complex, rendering the recognition of candidate receptors a challenging task. Herein, a review of the role of neuroimmunity in the biomolecular pathogenesis of AD is presented with the identification of a 'druggable dozen' targets; in turn, each identified target represents one or more discrete receptors centred on a common biochemical mechanism. The druggable dozen is composed of both cellular and molecular messenger targets, with a 'targetable ten' microglial targets as well as two cytokine-based targets. For each target, the underlying molecular basis, with a consideration of strengths and weaknesses, is considered.
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Affiliation(s)
- Donald F Weaver
- Krembil Research Institute, University Health Network, Department of Chemistry, University of Toronto 60 Leonard Avenue Toronto ON M5T 0S8 Canada
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Reiss AB, Muhieddine D, Jacob B, Mesbah M, Pinkhasov A, Gomolin IH, Stecker MM, Wisniewski T, De Leon J. Alzheimer's Disease Treatment: The Search for a Breakthrough. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1084. [PMID: 37374288 DOI: 10.3390/medicina59061084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/22/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023]
Abstract
As the search for modalities to cure Alzheimer's disease (AD) has made slow progress, research has now turned to innovative pathways involving neural and peripheral inflammation and neuro-regeneration. Widely used AD treatments provide only symptomatic relief without changing the disease course. The recently FDA-approved anti-amyloid drugs, aducanumab and lecanemab, have demonstrated unclear real-world efficacy with a substantial side effect profile. Interest is growing in targeting the early stages of AD before irreversible pathologic changes so that cognitive function and neuronal viability can be preserved. Neuroinflammation is a fundamental feature of AD that involves complex relationships among cerebral immune cells and pro-inflammatory cytokines, which could be altered pharmacologically by AD therapy. Here, we provide an overview of the manipulations attempted in pre-clinical experiments. These include inhibition of microglial receptors, attenuation of inflammation and enhancement of toxin-clearing autophagy. In addition, modulation of the microbiome-brain-gut axis, dietary changes, and increased mental and physical exercise are under evaluation as ways to optimize brain health. As the scientific and medical communities work together, new solutions may be on the horizon to slow or halt AD progression.
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Affiliation(s)
- Allison B Reiss
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | - Dalia Muhieddine
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | - Berlin Jacob
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | - Michael Mesbah
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | - Aaron Pinkhasov
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | - Irving H Gomolin
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
| | | | - Thomas Wisniewski
- Center for Cognitive Neurology, Departments of Neurology, Pathology and Psychiatry, NYU School of Medicine, New York, NY 10016, USA
| | - Joshua De Leon
- Department of Medicine and Biomedical Research Institute, NYU Long Island School of Medicine, Mineola, NY 11501, USA
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Fastenau C, Wickline JL, Smith S, Odfalk KF, Solano L, Bieniek KF, Hopp SC. Increased α-2,6 sialic acid on microglia in amyloid pathology is resistant to oseltamivir. GeroScience 2023; 45:1539-1555. [PMID: 36867284 PMCID: PMC10400525 DOI: 10.1007/s11357-023-00761-1] [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: 12/05/2022] [Accepted: 02/22/2023] [Indexed: 03/04/2023] Open
Abstract
Terminal sialic acid residues are present on most glycoproteins and glycolipids, but levels of sialylation are known to change in the brain throughout the lifespan as well as during disease. Sialic acids are important for numerous cellular processes including cell adhesion, neurodevelopment, and immune regulation as well as pathogen invasion into host cells. Neuraminidase enzymes, also known as sialidases, are responsible for removal of terminal sialic acids in a process known as desialylation. Neuraminidase 1 (Neu1) cleaves the α-2,6 bond of terminal sialic acids. Aging individuals with dementia are often treated with the antiviral medication oseltamivir, which is associated with induction of adverse neuropsychiatric side effects; this drug inhibits both viral and mammalian Neu1. The present study tested whether a clinically relevant antiviral dosing regimen of oseltamivir would disrupt behavior in the 5XFAD mouse model of Alzheimer's disease amyloid pathology or wild-type littermates. While oseltamivir treatment did not impact mouse behavior or modify amyloid plaque size or morphology, a novel spatial distribution of α-2,6 sialic acid residues was discovered in 5XFAD mice that was not present in wild-type littermates. Further analyses revealed that α-2,6 sialic acid residues were not localized the amyloid plaques but instead localized to plaque-associated microglia. Notably, treatment with oseltamivir did not alter α-2,6 sialic acid distribution on plaque-associated microglia in 5XFAD mice which may be due to downregulation of Neu1 transcript levels in 5XFAD mice. Overall, this study suggests that plaque-associated microglia are highly sialylated and are resistant to change with oseltamivir, thus interfering with microglia immune recognition of and response to amyloid pathology.
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Affiliation(s)
- Caitlyn Fastenau
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Jessica L Wickline
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Sabrina Smith
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Kristian F Odfalk
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Leigh Solano
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Kevin F Bieniek
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Sarah C Hopp
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX, USA.
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Abstract
Alzheimer's disease (AD) is a debilitating age-related neurodegenerative condition. Unbiased genetic studies have implicated a central role for microglia, the resident innate immune cells of the central nervous system, in AD pathogenesis. On-going efforts are clarifying the biology underlying these associations and the microglial pathways that are dysfunctional in AD. Several genetic risk factors converge to decrease the function of activating microglial receptors and increase the function of inhibitory receptors, resulting in a seemingly dampened microglial phenotype in AD. Moreover, many of these microglial proteins that are genetically associated with AD appear to interact and share pathways or regulatory mechanisms, presenting several points of convergence that may be strategic targets for therapeutic intervention. Here, we review some of these studies and their implications for microglial participation in AD pathogenesis.
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Huang J, Tao Q, Ang TFA, Farrell J, Zhu C, Wang Y, Stein TD, Lunetta KL, Massaro J, Mez J, Au R, Farrer LA, Qiu WQ, Zhang X. The impact of increasing levels of blood C-reactive protein on the inflammatory loci SPI1 and CD33 in Alzheimer's disease. Transl Psychiatry 2022; 12:523. [PMID: 36550123 PMCID: PMC9780312 DOI: 10.1038/s41398-022-02281-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/19/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Apolipoprotein ε4 (APOE ε4) is the most significant genetic risk factor for late-onset Alzheimer's disease (AD). Elevated blood C-reactive protein (CRP) further increases the risk of AD for people carrying the APOE ε4 allele. We hypothesized that CRP, as a key inflammatory element, could modulate the impact of other genetic variants on AD risk. We selected ten single nucleotide polymorphisms (SNPs) in reported AD risk loci encoding proteins related to inflammation. We then tested the interaction effects between these SNPs and blood CRP levels on AD incidence using the Cox proportional hazards model in UK Biobank (n = 279,176 white participants with 803 incident AD cases). The five top SNPs were tested for their interaction with different CRP cutoffs for AD incidence in the Framingham Heart Study (FHS) Generation 2 cohort (n = 3009, incident AD = 156). We found that for higher concentrations of serum CRP, the AD risk increased for SNP genotypes in 3 AD-associated genes (SPI1, CD33, and CLU). Using the Cox model in stratified genotype analysis, the hazard ratios (HRs) for the association between a higher CRP level (≥10 vs. <10 mg/L) and the risk of incident AD were 1.94 (95% CI: 1.33-2.84, p < 0.001) for the SPI1 rs1057233-AA genotype, 1.75 (95% CI: 1.20-2.55, p = 0.004) for the CD33 rs3865444-CC genotype, and 1.76 (95% CI: 1.25-2.48, p = 0.001) for the CLU rs9331896-C genotype. In contrast, these associations were not observed in the other genotypes of these genes. Finally, two SNPs were validated in 321 Alzheimer's Disease Neuroimaging (ADNI) Mild Cognitive Impairment (MCI) patients. We observed that the SPI1 and CD33 genotype effects were enhanced by elevated CRP levels for the risk of MCI to AD conversion. Furthermore, the SPI1 genotype was associated with CSF AD biomarkers, including t-Tau and p-Tau, in the ADNI cohort when the blood CRP level was increased (p < 0.01). Our findings suggest that elevated blood CRP, as a peripheral inflammatory biomarker, is an important moderator of the genetic effects of SPI1 and CD33 in addition to APOE ε4 on AD risk. Monitoring peripheral CRP levels may be helpful for precise intervention and prevention of AD for these genotype carriers.
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Affiliation(s)
- Jinghan Huang
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
| | - Qiushan Tao
- Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA
| | - Ting Fang Alvin Ang
- Departments of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - John Farrell
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
| | - Congcong Zhu
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
| | - Yixuan Wang
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
| | - Thor D Stein
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
- Alzheimer's Disease Research Center, Boston University School of Medicine, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
- VA Bedford Healthcare System, Bedford, MA, USA
| | - Kathryn L Lunetta
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
- Framingham Heart Study, Boston University School of Medicine, Framingham, MA, USA
| | - Joseph Massaro
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
- Framingham Heart Study, Boston University School of Medicine, Framingham, MA, USA
| | - Jesse Mez
- Alzheimer's Disease Research Center, Boston University School of Medicine, Boston, MA, USA
- Framingham Heart Study, Boston University School of Medicine, Framingham, MA, USA
- Departments of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Rhoda Au
- Departments of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
- Alzheimer's Disease Research Center, Boston University School of Medicine, Boston, MA, USA
- Framingham Heart Study, Boston University School of Medicine, Framingham, MA, USA
- Departments of Neurology, Boston University School of Medicine, Boston, MA, USA
| | - Lindsay A Farrer
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
- Alzheimer's Disease Research Center, Boston University School of Medicine, Boston, MA, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
- Framingham Heart Study, Boston University School of Medicine, Framingham, MA, USA
- Departments of Neurology, Boston University School of Medicine, Boston, MA, USA
- Departments of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
| | - Wei Qiao Qiu
- Departments of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA.
- Alzheimer's Disease Research Center, Boston University School of Medicine, Boston, MA, USA.
- Departments of Psychiatry, Boston University School of Medicine, Boston, MA, USA.
| | - Xiaoling Zhang
- Departments of Medicine (Biomedical Genetics), Boston University School of Medicine, Boston, MA, USA.
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
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Burns S, Selman A, Sehar U, Rawat P, Reddy AP, Reddy PH. Therapeutics of Alzheimer's Disease: Recent Developments. Antioxidants (Basel) 2022; 11:antiox11122402. [PMID: 36552610 PMCID: PMC9774459 DOI: 10.3390/antiox11122402] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
With increasing aging, dementia is a growing public health concern globally. Patients with dementia have multiple psychological and behavioral changes, including depression, anxiety, inappropriate behavior, paranoia, agitation, and hallucinations. The major types of dementia are Alzheimer's disease (AD), vascular dementia (VCID), Lewy body dementia (LBD), frontotemporal dementia (FTD), and mixed dementia (MiAD). Among these, AD is the most common form of dementia in the elderly population. In the last three decades, tremendous progress has been made in understanding AD's biology and disease progression, particularly its molecular basis, biomarker development, and drug discovery. Multiple cellular changes have been implicated in the progression of AD, including amyloid beta, phosphorylated tau, synaptic damage, mitochondrial dysfunction, deregulated microRNAs, inflammatory changes, hormonal deregulation, and others; based on these changes, therapeutic strategies have been developed, which are currently being tested in animal models and human clinical trials. The purpose of our article is to highlight recent therapeutic strategies' developments, critically discuss current strategies' failures, and propose new strategies to combat this devasting mental illness.
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Affiliation(s)
- Scott Burns
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Ashley Selman
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Ujala Sehar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Priyanka Rawat
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Arubala P. Reddy
- Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - P. Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Nutritional Sciences Department, College of Human Sciences, Texas Tech University, Lubbock, TX 79409, USA
- Correspondence: ; Tel.: +1-806-743-3194; Fax: +1-806-743-2334
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The Innate and Adaptive Immune Cells in Alzheimer’s and Parkinson’s Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1315248. [PMID: 36211819 PMCID: PMC9534688 DOI: 10.1155/2022/1315248] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/14/2022] [Accepted: 08/25/2022] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative disorders of the central nervous system (CNS). Increasing evidence supports the view that dysfunction of innate immune cells initiated by accumulated and misfolded proteins plays essential roles in the pathogenesis and progression of these diseases. The TLR family was found to be involved in the regulation of microglial function in the pathogenesis and progression of AD or PD, making it as double-edged sword in these diseases. Altered function of peripheral innate immune cells was found in AD and PD and thus contributed to the development and progression of AD and PD. Alteration of different subsets of T cells was found in the peripheral blood and CNS in AD and PD. The CNS-infiltrating T cells can exert both neuroprotective and neurotoxic effects in the pathogenesis and progression. Here, we review recent evidences for the roles of innate and adaptive immune cells in the pathogenesis and progression of AD and PD.
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12
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Novel Anti-Neuroinflammatory Properties of a Thiosemicarbazone–Pyridylhydrazone Copper(II) Complex. Int J Mol Sci 2022; 23:ijms231810722. [PMID: 36142627 PMCID: PMC9505367 DOI: 10.3390/ijms231810722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
Neuroinflammation has a major role in several brain disorders including Alzheimer’s disease (AD), yet at present there are no effective anti-neuroinflammatory therapeutics available. Copper(II) complexes of bis(thiosemicarbazones) (CuII(gtsm) and CuII(atsm)) have broad therapeutic actions in preclinical models of neurodegeneration, with CuII(atsm) demonstrating beneficial outcomes on neuroinflammatory markers in vitro and in vivo. These findings suggest that copper(II) complexes could be harnessed as a new approach to modulate immune function in neurodegenerative diseases. In this study, we examined the anti-neuroinflammatory action of several low-molecular-weight, charge-neutral and lipophilic copper(II) complexes. Our analysis revealed that one compound, a thiosemicarbazone–pyridylhydrazone copper(II) complex (CuL5), delivered copper into cells in vitro and increased the concentration of copper in the brain in vivo. In a primary murine microglia culture, CuL5 was shown to decrease secretion of pro-inflammatory cytokine macrophage chemoattractant protein 1 (MCP-1) and expression of tumor necrosis factor alpha (Tnf), increase expression of metallothionein (Mt1), and modulate expression of Alzheimer’s disease-associated risk genes, Trem2 and Cd33. CuL5 also improved the phagocytic function of microglia in vitro. In 5xFAD model AD mice, treatment with CuL5 led to an improved performance in a spatial working memory test, while, interestingly, increased accumulation of amyloid plaques in treated mice. These findings demonstrate that CuL5 can induce anti-neuroinflammatory effects in vitro and provide selective benefit in vivo. The outcomes provide further support for the development of copper-based compounds to modulate neuroinflammation in brain diseases.
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13
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Haure-Mirande JV, Audrain M, Ehrlich ME, Gandy S. Microglial TYROBP/DAP12 in Alzheimer's disease: Transduction of physiological and pathological signals across TREM2. Mol Neurodegener 2022; 17:55. [PMID: 36002854 PMCID: PMC9404585 DOI: 10.1186/s13024-022-00552-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/27/2022] [Indexed: 02/01/2023] Open
Abstract
TYROBP (also known as DAP12 or KARAP) is a transmembrane adaptor protein initially described as a receptor-activating subunit component of natural killer (NK) cells. TYROBP is expressed in numerous cell types, including peripheral blood monocytes, macrophages, dendritic cells, and osteoclasts, but a key point of recent interest is related to the critical role played by TYROBP in the function of many receptors expressed on the plasma membrane of microglia. TYROBP is the downstream adaptor and putative signaling partner for several receptors implicated in Alzheimer's disease (AD), including SIRP1β, CD33, CR3, and TREM2. TYROBP has received much of its current notoriety because of its importance in brain homeostasis by signal transduction across those receptors. In this review, we provide an overview of evidence indicating that the biology of TYROBP extends beyond its interaction with these four ligand-binding ectodomain-intramembranous domain molecules. In addition to reviewing the structure and localization of TYROBP, we discuss our recent progress using mouse models of either cerebral amyloidosis or tauopathy that were engineered to be TYROBP-deficient or TYROBP-overexpressing. Remarkably, constitutively TYROBP-deficient mice provided a model of genetic resilience to either of the defining proteinopathies of AD. Learning behavior and synaptic electrophysiological function were preserved at normal physiological levels even in the face of robust cerebral amyloidosis (in APP/PSEN1;Tyrobp-/- mice) or tauopathy (in MAPTP301S;Tyrobp-/- mice). A fundamental underpinning of the functional synaptic dysfunction associated with each proteotype was an accumulation of complement C1q. TYROBP deficiency prevented C1q accumulation associated with either proteinopathy. Based on these data, we speculate that TYROBP plays a key role in the microglial sensome and the emergence of the disease-associated microglia (DAM) phenotype. TYROBP may also play a key role in the loss of markers of synaptic integrity (e.g., synaptophysin-like immunoreactivity) that has long been held to be the feature of human AD molecular neuropathology that most closely correlates with concurrent clinical cognitive function.
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Affiliation(s)
| | - Mickael Audrain
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Michelle E. Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Sam Gandy
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Department of Psychiatry and the NIA-Designated Mount Sinai Alzheimer’s Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- James J Peters VA Medical Center, New York, Bronx NY 10468 USA
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14
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Alzheimer's Disease Risk Variant rs3865444 in the CD33 Gene: A Possible Role in Susceptibility to Multiple Sclerosis. Life (Basel) 2022; 12:life12071094. [PMID: 35888182 PMCID: PMC9324428 DOI: 10.3390/life12071094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/17/2022] [Accepted: 07/19/2022] [Indexed: 12/05/2022] Open
Abstract
Polymorphisms in genes encoding receptors that modulate the activity of microglia and macrophages are attractive candidates for participation in genetic susceptibility to multiple sclerosis (MS). The aims of the study were to (1) investigate the association between Alzheimer’s disease-linked variant rs3865444:C>A in the CD33 gene and MS risk, (2) assess the effect of the strongest MS risk allele HLA-DRB1*15:01 on this association, and (3) analyze the correlation of rs3865444 with selected clinical phenotypes, i.e., age of onset and disease severity. CD33 rs3865444 was genotyped in a cohort of 579 patients and 1145 controls and its association with MS risk and clinical phenotypes was analyzed by logistic and linear regression analysis, respectively. Statistical evaluation revealed that rs3865444 reduces the risk of MS in the HLA-DRB1*15:01-positive subpopulation but not in the cohort negative for HLA-DRB1*15:01. A significant antagonistic epistasis between rs3865444 A and HLA-DRB1*15:01 alleles in the context of MS risk was detected by the interaction synergy factor analysis. Comparison of allele and genotype distribution between relapsing-remitting MS, secondary progressive MS, and control groups revealed that rs3865444 C to A substitution may also be associated with a decreased risk of transition of MS to its secondary progressive form, irrespective of the HLA-DRB1*15:01 carrier status. On the other hand, no correlation could be found between rs3865444 and the age of disease onset or MS severity score. Future studies are required to shed more light on the role of CD33 in MS pathogenesis.
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15
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Long HZ, Zhou ZW, Cheng Y, Luo HY, Li FJ, Xu SG, Gao LC. The Role of Microglia in Alzheimer’s Disease From the Perspective of Immune Inflammation and Iron Metabolism. Front Aging Neurosci 2022; 14:888989. [PMID: 35847685 PMCID: PMC9284275 DOI: 10.3389/fnagi.2022.888989] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/13/2022] [Indexed: 12/25/2022] Open
Abstract
Alzheimer’s disease (AD), the most common type of senile dementia, includes the complex pathogenesis of abnormal deposition of amyloid beta-protein (Aβ), phosphorylated tau (p-tau) and neuroimmune inflammatory. The neurodegenerative process of AD triggers microglial activation, and the overactivation of microglia produces a large number of neuroimmune inflammatory factors. Microglia dysfunction can lead to disturbances in iron metabolism and enhance iron-induced neuronal degeneration in AD, while elevated iron levels in brain areas affect microglia phenotype and function. In this manuscript, we firstly discuss the role of microglia in AD and then introduce the role of microglia in the immune-inflammatory pathology of AD. Their role in AD iron homeostasis is emphasized. Recent studies on microglia and ferroptosis in AD are also reviewed. It will help readers better understand the role of microglia in iron metabolism in AD, and provides a basis for better regulation of iron metabolism disorders in AD and the discovery of new potential therapeutic targets for AD.
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Affiliation(s)
- Hui-Zhi Long
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Zi-Wei Zhou
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Yan Cheng
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Hong-Yu Luo
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Feng-Jiao Li
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Shuo-Guo Xu
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
| | - Li-Chen Gao
- School of Pharmacy, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang, China
- *Correspondence: Li-Chen Gao,
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16
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Xin Y, Sheng J, Miao M, Wang L, Yang Z, Huang H. A review ofimaging genetics in Alzheimer's disease. J Clin Neurosci 2022; 100:155-163. [PMID: 35487021 DOI: 10.1016/j.jocn.2022.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 03/01/2022] [Accepted: 04/15/2022] [Indexed: 01/18/2023]
Abstract
Determining the association between genetic variation and phenotype is a key step to study the mechanism of Alzheimer's disease (AD), laying the foundation for studying drug therapies and biomarkers. AD is the most common type of dementia in the aged population. At present, three early-onset AD genes (APP, PSEN1, PSEN2) and one late-onset AD susceptibility gene apolipoprotein E (APOE) have been determined. However, the pathogenesis of AD remains unknown. Imaging genetics, an emerging interdisciplinary field, is able to reveal the complex mechanisms from the genetic level to human cognition and mental disorders via macroscopic intermediates. This paper reviews methods of establishing genotype-phenotype to explore correlations, including sparse canonical correlation analysis, sparse reduced rank regression, sparse partial least squares and so on. We found that most research work did poorly in supervised learning and exploring the nonlinear relationship between SNP-QT.
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Affiliation(s)
- Yu Xin
- College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China; Key Laboratory of Intelligent Image Analysis for Sensory and Cognitive Health, Ministry of Industry and Information Technology of China, Hangzhou, Zhejiang 310018, China
| | - Jinhua Sheng
- College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China; Key Laboratory of Intelligent Image Analysis for Sensory and Cognitive Health, Ministry of Industry and Information Technology of China, Hangzhou, Zhejiang 310018, China.
| | - Miao Miao
- Beijing Hospital, Beijing 100730, China; National Center of Gerontology, Beijing 100730, China; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Luyun Wang
- College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China; Key Laboratory of Intelligent Image Analysis for Sensory and Cognitive Health, Ministry of Industry and Information Technology of China, Hangzhou, Zhejiang 310018, China; Hangzhou Vocational & Technical College, Hangzhou, Zhejiang 310018, China
| | - Ze Yang
- College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China; Key Laboratory of Intelligent Image Analysis for Sensory and Cognitive Health, Ministry of Industry and Information Technology of China, Hangzhou, Zhejiang 310018, China
| | - He Huang
- College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China; Key Laboratory of Intelligent Image Analysis for Sensory and Cognitive Health, Ministry of Industry and Information Technology of China, Hangzhou, Zhejiang 310018, China
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17
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Liu P, Wang Y, Sun Y, Peng G. Neuroinflammation as a Potential Therapeutic Target in Alzheimer’s Disease. Clin Interv Aging 2022; 17:665-674. [PMID: 35520949 PMCID: PMC9064449 DOI: 10.2147/cia.s357558] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 04/12/2022] [Indexed: 12/14/2022] Open
Abstract
Although amyloid-β (Aβ) peptide accumulation is considered as a key early event in the pathogenesis of Alzheimer’s disease (AD), the precise pathophysiology of this deadly illness remains unclear and no effective remedies capable of inhibiting disease progression have been discovered. In addition to deposition of extracellular Aβ plaques and intracellular neurofibrillary tangles, neuroinflammation has been identified as the third core characteristic crucial in the pathogenesis of AD. More and more evidence from laboratory and clinical studies have suggested that anti-inflammatory treatments could defer or prevent the occurrence of AD. In this review, we will discuss multifaceted evidence of neuroinflammation presented in AD and the newly emerged anti-inflammatory targets both in pre-clinical and clinical AD.
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Affiliation(s)
- Ping Liu
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
| | - Yunyun Wang
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
- Department of Neurology, Shengzhou People’s Hospital, Shaoxing, People’s Republic of China
| | - Yan Sun
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
| | - Guoping Peng
- Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China
- Correspondence: Guoping Peng, Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province, 310003, People’s Republic of China, Tel +86 13588150613, Email
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18
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Zaidi N, Ajmal MR, Zaidi SA, Khan RH. Mechanistic In Vitro Dissection of the Inhibition of Amyloid Fibrillation by n-Acetylneuraminic Acid: Plausible Implication in Therapeutics for Neurodegenerative Disorders. ACS Chem Neurosci 2022; 13:69-80. [PMID: 34878262 DOI: 10.1021/acschemneuro.1c00556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A variety of neurodegenerative disorders including Parkinson's disease are due to fibrillation in amyloidogenic proteins. The development of therapeutics for these disorders is a topic of extensive research as effective treatments are still unavailable. The present study establishes that n-acetylneuraminic acid (Neu5ac) inhibits the amyloid fibrillation of hen egg-white lysozyme (HEWL) and α-synuclein (SYN), as observed using various biophysical techniques and cellular assays. Neu5ac inhibits the amyloid formation in both proteins, as suggested from the reduction in the ThT fluorescence and remnant structures in transmission electron microscopy micrographs observed in its presence. In HEWL fibrillation, Neu5ac decreases the hydrophobicity and resists the transition of the α-helix to a β-sheet, as observed by an ANS binding assay, circular dichroism (CD) spectra, and Fourier transform infrared measurements, respectively. Neu5ac stabilizes the states that facilitate the amyloid formation in HEWL and SYN, as demonstrated by an enhanced intrinsic fluorescence in its presence, which is further confirmed by an increase in Tm obtained from differential scanning calorimetry thermograms and an increase in the near-UV CD signal for HEWL with Neu5ac. However, the increase in stability is not a manifestation of Neu5ac binding to amyloid facilitating (partially folded or native) states of both proteins, as verified by isothermal titration calorimetry and fluorescence binding measurements. Besides, Neu5ac also attenuates the cytotoxicity of amyloid fibrils, as evaluated by a cell toxicity assay. These findings provide mechanistic insights into the Neu5ac action against amyloid fibrillation and may establish it as a plausible inhibitor molecule against neurodegenerative disorders.
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Affiliation(s)
- Nida Zaidi
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Mohammad Rehan Ajmal
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Syed Adeel Zaidi
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
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19
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Rabaneda-Bueno R, Mena-Montes B, Torres-Castro S, Torres-Carrillo N, Torres-Carrillo NM. Advances in Genetics and Epigenetic Alterations in Alzheimer's Disease: A Notion for Therapeutic Treatment. Genes (Basel) 2021; 12:1959. [PMID: 34946908 PMCID: PMC8700838 DOI: 10.3390/genes12121959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is a disabling neurodegenerative disorder that leads to long-term functional and cognitive impairment and greatly reduces life expectancy. Early genetic studies focused on tracking variations in genome-wide DNA sequences discovered several polymorphisms and novel susceptibility genes associated with AD. However, despite the numerous risk factors already identified, there is still no fully satisfactory explanation for the mechanisms underlying the onset of the disease. Also, as with other complex human diseases, the causes of low heritability are unclear. Epigenetic mechanisms, in which changes in gene expression do not depend on changes in genotype, have attracted considerable attention in recent years and are key to understanding the processes that influence age-related changes and various neurological diseases. With the recent use of massive sequencing techniques, methods for studying epigenome variations in AD have also evolved tremendously, allowing the discovery of differentially expressed disease traits under different conditions and experimental settings. This is important for understanding disease development and for unlocking new potential AD therapies. In this work, we outline the genomic and epigenomic components involved in the initiation and development of AD and identify potentially effective therapeutic targets for disease control.
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Affiliation(s)
- Rubén Rabaneda-Bueno
- Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, 37005 České Budějovice, Czech Republic
- School of Biological Sciences, James Clerk Maxwell Building, The King’s Buildings Campus, University of Edinburgh, Edinburgh EH9 3FD, UK
| | - Beatriz Mena-Montes
- Laboratorio de Biología del Envejecimiento, Departamento de Investigación Básica, Instituto Nacional de Geriatría, Mexico City 10200, Mexico;
| | - Sara Torres-Castro
- Departamento de Epidemiología Demográfica y Determinantes Sociales, Instituto Nacional de Geriatría, Mexico City 10200, Mexico;
| | - Norma Torres-Carrillo
- Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico; (N.T.-C.); (N.M.T.-C.)
| | - Nora Magdalena Torres-Carrillo
- Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico; (N.T.-C.); (N.M.T.-C.)
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20
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Lennon MJ, Rigney G, Raymont V, Sachdev P. Genetic Therapies for Alzheimer's Disease: A Scoping Review. J Alzheimers Dis 2021; 84:491-504. [PMID: 34569966 DOI: 10.3233/jad-215145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Effective, disease modifying therapies for Alzheimer's disease (AD) remain a quandary, following a panoply of expensive failures in human clinical trials. Given the stagnation in therapeutics, alternative approaches are needed. Recent successes of genetic therapies in other neurodegenerative diseases may highlight the way forward. This scoping review explores suggested targets of genetic therapy in AD, with a focus on vector-based approaches in pre-clinical and clinical trials. Putative targets of genetic therapies tested in pre-clinical trials include amyloid pathway intermediates and enzymes modulation, tau protein downregulation, APOE4 downregulation and APOE2 upregulation, neurotrophin expression (nerve growth factor (NGF) and brain-derived neurotrophic factor), and inflammatory cytokine alteration, among several other approaches. There have been three completed human clinical trials for genetic therapy in AD patients, all of which upregulated NGF in AD patients, showing some mixed evidence of benefit. Several impediments remain to be surpassed before genetic therapies can be successfully applied to AD, including the challenge of delivering monogenic genetic therapies for complex polygenic disorders, risks in the dominant delivery method (intracranial injection), stability of genetic therapies in vivo, poor translatability of pre-clinical AD models, and the expense of genetic therapy production. Genetic therapies represent an exciting opportunity within the world of AD therapeutics, but clinical applications likely remain a long term, rather than short term, possibility.
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Affiliation(s)
- Matthew J Lennon
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK.,Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Grant Rigney
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Perminder Sachdev
- Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
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21
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Griciuc A, Federico AN, Natasan J, Forte AM, McGinty D, Nguyen H, Volak A, LeRoy S, Gandhi S, Lerner EP, Hudry E, Tanzi RE, Maguire CA. Gene therapy for Alzheimer's disease targeting CD33 reduces amyloid beta accumulation and neuroinflammation. Hum Mol Genet 2021; 29:2920-2935. [PMID: 32803224 DOI: 10.1093/hmg/ddaa179] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/03/2020] [Accepted: 07/29/2020] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammation is a key contributor to the pathology of Alzheimer's disease (AD). CD33 (Siglec-3) is a transmembrane sialic acid-binding receptor on the surface of microglial cells. CD33 is upregulated on microglial cells from post-mortem AD patient brains, and high levels of CD33 inhibit uptake and clearance of amyloid beta (Aβ) in microglial cell cultures. Furthermore, knockout of CD33 reduces amyloid plaque burden in mouse models of AD. Here, we tested whether a gene therapy strategy to reduce CD33 on microglia in AD could decrease Aβ plaque load. Intracerebroventricular injection of an adeno-associated virus (AAV) vector-based system encoding an artificial microRNA targeting CD33 (miRCD33) into APP/PS1 mice reduced CD33 mRNA and TBS-soluble Aβ40 and Aβ42 levels in brain extracts. Treatment of APP/PS1 mice with miRCD33 vector at an early age (2 months) was more effective at reducing Aβ plaque burden than intervening at later times (8 months). Furthermore, early intervention downregulated several microglial receptor transcripts (e.g. CD11c, CD47 and CD36) and pro-inflammatory activation genes (e.g. Tlr4 and Il1b). Marked reductions in the chemokine Ccl2 and the pro-inflammatory cytokine Tnfα were observed at the protein level in the brain of APP/PS1 mice treated with miRCD33 vector. Overall, our data indicate that CD33 is a viable target for AAV-based knockdown strategies to reduce AD pathology. One Sentence Summary: A gene therapy approach for Alzheimer's disease using adeno-associated virus vector-based knockdown of CD33 reduced amyloid beta accumulation and neuroinflammation.
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Affiliation(s)
- Ana Griciuc
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Anthony N Federico
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jeyashree Natasan
- Molecular Neurogenetics Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02114, USA
| | - Angela M Forte
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Danielle McGinty
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Huong Nguyen
- Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Adrienn Volak
- Molecular Neurogenetics Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02114, USA
| | - Stanley LeRoy
- Molecular Neurogenetics Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02114, USA
| | - Sheetal Gandhi
- Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Eli P Lerner
- Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Eloise Hudry
- Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Casey A Maguire
- Molecular Neurogenetics Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02114, USA
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22
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Abstract
PURPOSE OF REVIEW The aim of this study was to provide an update on the role of the innate immune system and neuroinflammation in the pathogenesis of Alzheimer's disease, with an emphasis on microglial receptors CD33 and TREM2. RECENT FINDINGS Genome-wide association studies (GWAS) have identified many Alzheimer's disease risk genes related to immune response and microglia including the phagocytic receptors CD33 and TREM2. Recent GWAS and pathway analyses emphasize the crucial role of the innate immune system and neuroinflammation in the pathogenesis of Alzheimer's disease. Disease-associated microglia have been characterized by TREM2-dependent upregulation of phagocytic and lipid metabolism genes. Impaired microglial phagocytosis results in amyloid beta (Aβ) accumulation leading to neuroinflammation that is the primary cause of neurodegeneration. CD33 and TREM2 modulate neuroinflammation in Alzheimer's disease and have emerged as therapeutic targets in Alzheimer's disease. Progress has been made to inhibit CD33 by gene therapy, small molecules or immunotherapy, and to increase TREM2 activity by immunotherapy. Finally, mAbs against CD33 and TREM2 have entered clinical trials and may reduce neuroinflammation in Alzheimer's disease brain. SUMMARY Targeting neuroinflammation via CD33 inhibition and/or TREM2 activation may have important implications for neurodegeneration in Alzheimer's disease and may be an addition to monoclonal anti-Aβ antibody treatments that remove plaques without reducing neuroinflammation.
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Affiliation(s)
- Ana Griciuc
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
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Functions and therapeutic targets of Siglec-mediated infections, inflammations and cancers. J Formos Med Assoc 2021; 120:5-24. [DOI: 10.1016/j.jfma.2019.10.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/11/2019] [Accepted: 10/28/2019] [Indexed: 12/20/2022] Open
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Siokas V, Tsouris Z, Aloizou AM, Bakirtzis C, Liampas I, Koutsis G, Anagnostouli M, Bogdanos DP, Grigoriadis N, Hadjigeorgiou GM, Dardiotis E. Multiple Sclerosis: Shall We Target CD33? Genes (Basel) 2020; 11:E1334. [PMID: 33198164 PMCID: PMC7696272 DOI: 10.3390/genes11111334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS). Myeloid lineage cells (microglia and macrophages) may participate in the pathogenic mechanisms leading to MS. CD33 is a transmembrane receptor, mainly expressed by myeloid lineage cells. CD33 rs3865444 is a promoter variant previously associated with Alzheimer's disease, whose role in MS remains obscure. OBJECTIVE To assess the role of CD33 rs3865444 in MS risk. METHODS We genotyped 1396 patients with MS and 400 healthy controls for the presence of the CD33 rs3865444 variant. Odds ratios (ORs) with the respective 95% confidence intervals (CIs), were calculated with the SNPStats software, assuming five genetic models (co-dominant, dominant, recessive, over-dominant, and log-additive), with the G allele as the reference allele. The value of 0.05 was set as the threshold for statistical significance. RESULTS CD33 rs3865444 was associated with MS risk in the dominant (GG vs. GT + TT; OR (95% C.I.) = 0.79 (0.63-0.99), p = 0.041) and the over-dominant (GG + TT vs. GT; OR (95% C.I.) = 0.77 (0.61-0.97), p = 0.03) modes of inheritance. Given that the GG genotype was more frequent and the GT genotype was less frequent in MS patients compared to controls-while the observed frequency of the TT genotype did not differ between the two groups-the observed difference in MS risk may be stemming from either the GG (as a risk factor) or the GT (as a protective factor) genotype of CD33 rs3865444. CONCLUSIONS Our preliminary results suggest a possible contribution of CD33 rs3865444 to MS. Therefore, larger multiethnic studies should be conducted, investigating the role of CD33 rs3865444 in MS.
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Affiliation(s)
- Vasileios Siokas
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
| | - Zisis Tsouris
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
| | - Athina-Maria Aloizou
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
| | - Christos Bakirtzis
- Multiple Sclerosis Center, B’ Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece; (C.B.); (N.G.)
| | - Ioannis Liampas
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
| | - Georgios Koutsis
- Neurogenetics Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Vassilissis Sofias 72-74 Ave, 11528 Athens, Greece;
| | - Maria Anagnostouli
- Multiple Sclerosis and Demyelinating Diseases Unit and Immunogenetics Laboratory, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, 115 28 Athens, Greece;
| | - Dimitrios P. Bogdanos
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece;
| | - Nikolaos Grigoriadis
- Multiple Sclerosis Center, B’ Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, GR54636 Thessaloniki, Greece; (C.B.); (N.G.)
| | - Georgios M. Hadjigeorgiou
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
- Department of Neurology, Medical School, University of Cyprus, 1678 Nicosia, Cyprus
| | - Efthimios Dardiotis
- Laboratory of Neurogenetics, Department of Neurology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (V.S.); (Ζ.Τ.); (A.-M.A.); (I.L.); (G.M.H.)
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Swanson MEV, Scotter EL, Smyth LCD, Murray HC, Ryan B, Turner C, Faull RLM, Dragunow M, Curtis MA. Identification of a dysfunctional microglial population in human Alzheimer's disease cortex using novel single-cell histology image analysis. Acta Neuropathol Commun 2020; 8:170. [PMID: 33081847 PMCID: PMC7576851 DOI: 10.1186/s40478-020-01047-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/02/2020] [Indexed: 01/04/2023] Open
Abstract
In Alzheimer's disease (AD), microglia are affected by disease processes, but may also drive pathogenesis. AD pathology-associated microglial populations have been identified with single-cell RNA-Seq, but have not been validated in human brain tissue with anatomical context. Here, we quantified myeloid cell markers to identify changes in AD pathology-associated microglial populations. We performed fluorescent immunohistochemistry on normal (n = 8) and AD (n = 8) middle temporal gyri, co-labelling the pan-myeloid cell marker, Iba1, with one of 11 markers of interest (MOIs): CD45, HLA-DR, CD14, CD74, CD33, CD206, CD32, CD163, P2RY12, TMEM119, L-Ferritin. Novel image analyses quantified the single-cell abundance of Iba1 and each MOI. Each cell was gated into one Iba1-MOI population (Iba1low MOIhigh, Iba1high MOIhigh, or Iba1high MOIlow) and the abundance of each population was compared between AD and control. Triple-labelling of L-Ferritin and Iba1 with a subset of MOIs was performed to investigate L-Ferritin-MOI co-expression on Iba1low cells. Iba1low MOIhigh myeloid cell populations delineated by MOIs CD45, HLA-DR, CD14, CD74, CD33, CD32, and L-Ferritin were increased in AD. Further investigation of the Iba1low MOIhigh populations revealed that their abundances correlated with tau, but not amyloid beta, load in AD. The Iba1low microglial population highly expressed L-Ferritin, reflecting microglial dysfunction. The L-Ferritinhigh CD74high HLA-DRhigh phenotype of the Iba1low population mirrors that of a human AD pathology-associated microglial subpopulation previously identified using single-cell RNA-Seq. Our high-throughput immunohistochemical data with anatomical context support the microglial dysfunction hypothesis of AD.
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Ennerfelt HE, Lukens JR. The role of innate immunity in Alzheimer's disease. Immunol Rev 2020; 297:225-246. [PMID: 32588460 PMCID: PMC7783860 DOI: 10.1111/imr.12896] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022]
Abstract
The amyloid hypothesis has dominated Alzheimer's disease (AD) research for almost 30 years. This hypothesis hinges on the predominant clinical role of the amyloid beta (Aβ) peptide in propagating neurofibrillary tangles (NFTs) and eventual cognitive impairment in AD. Recent research in the AD field has identified the brain-resident macrophages, known as microglia, and their receptors as integral regulators of both the initiation and propagation of inflammation, Aβ accumulation, neuronal loss, and memory decline in AD. Emerging studies have also begun to reveal critical roles for distinct innate immune pathways in AD pathogenesis, which has led to great interest in harnessing the innate immune response as a therapeutic strategy to treat AD. In this review, we will highlight recent advancements in our understanding of innate immunity and inflammation in AD onset and progression. Additionally, there has been mounting evidence suggesting pivotal contributions of environmental factors and lifestyle choices in AD pathogenesis. Therefore, we will also discuss recent findings, suggesting that many of these AD risk factors influence AD progression via modulation of microglia and immune responses.
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Affiliation(s)
- Hannah E. Ennerfelt
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - John R. Lukens
- Center for Brain Immunology and Glia (BIG), Department of Neuroscience, University of Virginia, Charlottesville, VA 22908, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Cell and Molecular Biology Training Program, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
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Liao H, Klaus C, Neumann H. Control of Innate Immunity by Sialic Acids in the Nervous Tissue. Int J Mol Sci 2020; 21:ijms21155494. [PMID: 32752058 PMCID: PMC7432451 DOI: 10.3390/ijms21155494] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
Sialic acids (Sias) are the most abundant terminal sugar residues of glycoproteins and glycolipids on the surface of mammalian cells. The nervous tissue is the organ with the highest expression level of Sias. The ‘sialylation’ of glycoconjugates is performed via sialyltransferases, whereas ‘desialylation’ is done by sialidases or is a possible consequence of oxidative damage. Sialic acid residues on the neural cell surfaces inhibit complement and microglial activation, as well as phagocytosis of the underlying structures, via binding to (i) complement factor H (CFH) or (ii) sialic acid-binding immunoglobulin-like lectin (SIGLEC) receptors. In contrast, activated microglial cells show sialidase activity that desialylates both microglia and neurons, and further stimulates innate immunity via microglia and complement activation. The desialylation conveys neurons to become susceptible to phagocytosis, as well as triggers a microglial phagocytosis-associated oxidative burst and inflammation. Dysfunctions of the ‘Sia–SIGLEC’ and/or ‘Sia–complement’ axes often lead to neurological diseases. Thus, Sias on glycoconjugates of the intact glycocalyx and its desialylation are major regulators of neuroinflammation.
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Affiliation(s)
| | | | - Harald Neumann
- Correspondence: ; Tel.: +49-228-6885-500; Fax: +49-228-6885-501
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Rodríguez-Gómez JA, Kavanagh E, Engskog-Vlachos P, Engskog MK, Herrera AJ, Espinosa-Oliva AM, Joseph B, Hajji N, Venero JL, Burguillos MA. Microglia: Agents of the CNS Pro-Inflammatory Response. Cells 2020; 9:E1717. [PMID: 32709045 PMCID: PMC7407646 DOI: 10.3390/cells9071717] [Citation(s) in RCA: 168] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/21/2022] Open
Abstract
The pro-inflammatory immune response driven by microglia is a key contributor to the pathogenesis of several neurodegenerative diseases. Though the research of microglia spans over a century, the last two decades have increased our understanding exponentially. Here, we discuss the phenotypic transformation from homeostatic microglia towards reactive microglia, initiated by specific ligand binding to pattern recognition receptors including toll-like receptor-4 (TLR4) or triggering receptors expressed on myeloid cells-2 (TREM2), as well as pro-inflammatory signaling pathways triggered such as the caspase-mediated immune response. Additionally, new research disciplines such as epigenetics and immunometabolism have provided us with a more holistic view of how changes in DNA methylation, microRNAs, and the metabolome may influence the pro-inflammatory response. This review aimed to discuss our current knowledge of pro-inflammatory microglia from different angles, including recent research highlights such as the role of exosomes in spreading neuroinflammation and emerging techniques in microglia research including positron emission tomography (PET) scanning and the use of human microglia generated from induced pluripotent stem cells (iPSCs). Finally, we also discuss current thoughts on the impact of pro-inflammatory microglia in neurodegenerative diseases.
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Affiliation(s)
- José A. Rodríguez-Gómez
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain; (J.A.R.-G.); (A.J.H.); (A.M.E.-O.); (J.L.V.)
- Department of Medical Physiology and Biophysics, Faculty of Medicine, University of Seville, 41009 Sevilla, Spain
| | - Edel Kavanagh
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain;
| | - Pinelopi Engskog-Vlachos
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institute, 17177 Stockholm, Sweden; (P.E.-V.); (B.J.)
| | - Mikael K.R. Engskog
- Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry, Uppsala University, 751 23 Uppsala, Sweden;
| | - Antonio J. Herrera
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain; (J.A.R.-G.); (A.J.H.); (A.M.E.-O.); (J.L.V.)
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain;
| | - Ana M. Espinosa-Oliva
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain; (J.A.R.-G.); (A.J.H.); (A.M.E.-O.); (J.L.V.)
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain;
| | - Bertrand Joseph
- Institute of Environmental Medicine, Toxicology Unit, Karolinska Institute, 17177 Stockholm, Sweden; (P.E.-V.); (B.J.)
| | - Nabil Hajji
- Division of Brain Sciences, The John Fulcher Molecular Neuro-Oncology Laboratory, Imperial College London, London W12 ONN, UK;
| | - José L. Venero
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain; (J.A.R.-G.); (A.J.H.); (A.M.E.-O.); (J.L.V.)
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain;
| | - Miguel A. Burguillos
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain; (J.A.R.-G.); (A.J.H.); (A.M.E.-O.); (J.L.V.)
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain;
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Puigdellívol M, Allendorf DH, Brown GC. Sialylation and Galectin-3 in Microglia-Mediated Neuroinflammation and Neurodegeneration. Front Cell Neurosci 2020; 14:162. [PMID: 32581723 PMCID: PMC7296093 DOI: 10.3389/fncel.2020.00162] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 05/15/2020] [Indexed: 12/31/2022] Open
Abstract
Microglia are brain macrophages that mediate neuroinflammation and contribute to and protect against neurodegeneration. The terminal sugar residue of all glycoproteins and glycolipids on the surface of mammalian cells is normally sialic acid, and addition of this negatively charged residue is known as “sialylation,” whereas removal by sialidases is known as “desialylation.” High sialylation of the neuronal cell surface inhibits microglial phagocytosis of such neurons, via: (i) activating sialic acid receptors (Siglecs) on microglia that inhibit phagocytosis and (ii) inhibiting binding of opsonins C1q, C3, and galectin-3. Microglial sialylation inhibits inflammatory activation of microglia via: (i) activating Siglec receptors CD22 and CD33 on microglia that inhibit phagocytosis and (ii) inhibiting Toll-like receptor 4 (TLR4), complement receptor 3 (CR3), and other microglial receptors. When activated, microglia release a sialidase activity that desialylates both microglia and neurons, activating the microglia and rendering the neurons susceptible to phagocytosis. Activated microglia also release galectin-3 (Gal-3), which: (i) further activates microglia via binding to TLR4 and TREM2, (ii) binds to desialylated neurons opsonizing them for phagocytosis via Mer tyrosine kinase, and (iii) promotes Aβ aggregation and toxicity in vivo. Gal-3 and desialylation may increase in a variety of brain pathologies. Thus, Gal-3 and sialidases are potential treatment targets to prevent neuroinflammation and neurodegeneration.
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Affiliation(s)
- Mar Puigdellívol
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - David H Allendorf
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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Javor J, Ďurmanová V, Párnická Z, Minárik G, Králová M, Pečeňák J, Vašečková B, Režnáková V, Šutovský S, Gmitterová K, Hromádka T, Peterajová Ľ, Shawkatová I. Association of CD33 rs3865444:C˃A polymorphism with a reduced risk of late-onset Alzheimer's disease in Slovaks is limited to subjects carrying the APOE ε4 allele. Int J Immunogenet 2020; 47:397-405. [PMID: 32333488 DOI: 10.1111/iji.12489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 03/04/2020] [Accepted: 03/22/2020] [Indexed: 12/17/2022]
Abstract
CD33 rs3865444:C>A single nucleotide polymorphism (SNP) has been previously associated with the risk of late-onset Alzheimer's disease (LOAD); however, the results have been inconsistent across different populations. CD33 is a transmembrane receptor that plays an important role in AD pathogenesis by inhibiting amyloid β42 uptake by microglial cells. In this study, we aimed to validate the association between rs3865444 and LOAD risk in the Slovak population and to evaluate whether it was affected by the carrier status of the major LOAD risk allele apolipoprotein (APOE) ε4. CD33 rs3865444 and APOE variants were genotyped in 206 LOAD patients and 487 control subjects using the polymerase chain reaction-restriction fragment length polymorphism method and direct sequencing, respectively. Logistic regression analysis revealed a significant association of rs3865444 A allele with a reduced LOAD risk that was only present in APOE ε4 allele carriers (AA + CA versus CC: p = .0085; OR = 0.45; 95% CI = 0.25-0.82). On the other hand, no such association was found in subjects without the APOE ε4 (p = .75; OR = 0.93; 95% CI = 0.61-1.42). Moreover, regression analysis detected a significant interaction between CD33 rs3865444 A and APOE ε4 alleles (p = .021 for APOE ε4 allele dosage and p = .051 for APOE ε4 carriage status), with synergy factor (SF) value of 0.49 indicating an antagonistic effect between the two alleles in LOAD risk. In conclusion, our results suggest that CD33 rs3865444:C˃A substitution may reduce the risk of LOAD in Slovaks by antagonizing the effect conferred by the major susceptibility allele APOE ε4.
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Affiliation(s)
- Juraj Javor
- Institute of Immunology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Vladimíra Ďurmanová
- Institute of Immunology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Zuzana Párnická
- Institute of Immunology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Gabriel Minárik
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Mária Králová
- Department of Psychiatry, Faculty of Medicine, Comenius University in Bratislava and University Hospital, Bratislava, Slovakia
| | - Ján Pečeňák
- Department of Psychiatry, Faculty of Medicine, Comenius University in Bratislava and University Hospital, Bratislava, Slovakia
| | - Barbora Vašečková
- Psychiatry Outpatient Clinic, University Hospital with Polyclinic the Brothers of Saint John of God, Bratislava, Slovakia
| | | | - Stanislav Šutovský
- 1st Department of Neurology, Faculty of Medicine, Comenius University in Bratislava and University Hospital, Bratislava, Slovakia
| | - Karin Gmitterová
- 2nd Department of Neurology, Faculty of Medicine, Comenius University in Bratislava and University Hospital, Bratislava, Slovakia
| | - Tomáš Hromádka
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ľubica Peterajová
- Haematology Outpatient Clinic, University Hospital, Bratislava, Slovakia
| | - Ivana Shawkatová
- Institute of Immunology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
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Anwar S, Rivest S. Alzheimer's disease: microglia targets and their modulation to promote amyloid phagocytosis and mitigate neuroinflammation. Expert Opin Ther Targets 2020; 24:331-344. [PMID: 32129117 DOI: 10.1080/14728222.2020.1738391] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Introduction: Despite the revolutionary progress in neurodegenerative disease research, there is no cure for Alzheimer's disease (AD). This is a chronic progressive neurodegenerative disease affecting aged people and is associated with chronic neuroinflammation and amyloid-beta (Aβ) deposition in the brain parenchyma. Microglia, the resident myeloid cells in the central nervous system, are critically involved in the pathogenesis of AD and have emerged as a potential therapeutic target for treating or preventing AD. The failure of microglia to keep up with persistent amyloid-beta development along with secretion of inflammatory cytokines is detrimental to neurons and favors Aβ accumulation.Areas covered: This review illuminates the latest research that is focused on molecules and their intracellular targets that promote microglial phagocytosis and /or its polarization to an anti-inflammatory state.Expert opinion: A robust inflammatory response of microglia is not necessary to improve their efficiency of Aβ clearance. The challenge is to master inflammatory/anti-inflammatory phenotypes depending on the stage of AD and to maintain efficient responses to remove Aβ. Therefore, promoting microglia phagocytosis without a persistent excessive inflammatory response could be a potential therapeutic strategy.
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Affiliation(s)
- Shehata Anwar
- Neuroscience Laboratory, CHU de Québec Research Center (CHUL), Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada.,Department of Pathology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Serge Rivest
- Neuroscience Laboratory, CHU de Québec Research Center (CHUL), Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
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Does the CD33 rs3865444 Polymorphism Confer Susceptibility to Alzheimer’s Disease? J Mol Neurosci 2020; 70:851-860. [DOI: 10.1007/s12031-020-01507-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 02/05/2020] [Indexed: 12/13/2022]
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Zulfiqar S, Garg P, Nieweg K. Contribution of astrocytes to metabolic dysfunction in the Alzheimer's disease brain. Biol Chem 2020; 400:1113-1127. [PMID: 31188740 DOI: 10.1515/hsz-2019-0140] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/28/2019] [Indexed: 11/15/2022]
Abstract
Historically considered as accessory cells to neurons, there is an increasing interest in the role of astrocytes in normal and pathological conditions. Astrocytes are involved in neurotransmitter recycling, antioxidant supply, ion buffering and neuroinflammation, i.e. a lot of the same pathways that go astray in Alzheimer's disease (AD). AD remains the leading cause of dementia in the elderly, one for which there is still no cure. Efforts in AD drug development have largely focused on treating neuronal pathologies that appear relatively late in the disease. The neuroenergetic hypothesis, however, focuses on the early event of glucose hypometabolism in AD, where astrocytes play a key role, caused by an imbalanced neuron-astrocyte lactate shuttle. This further results in a state of oxidative stress and neuroinflammation, thereby compromising the integrity of astrocyte-neuron interaction. Compromised astrocytic energetics also enhance amyloid generation, further increasing the severity of the disease. Additionally, apolipoprotein E (APOE), the major genetic risk factor for AD, is predominantly secreted by astrocytes and plays a critical role in amyloid clearance and regulates glucose metabolism in an amyloid-independent manner. Thus, boosting the neuroprotective properties of astrocytes has potential applications in delaying the onset and progression of AD. This review explores how the metabolic dysfunction arising from astrocytes acts as a trigger for the development of AD.
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Affiliation(s)
- Shadaan Zulfiqar
- Institute for Pharmacology and Clinical Pharmacy, Philipps University, Karl-von-Frisch Strasse, Marburg D-35043, Germany.,Marburg Center for Mind, Brain and Behavior, Philipps University, Marburg, Germany
| | - Pretty Garg
- Institute for Pharmacology and Clinical Pharmacy, Philipps University, Karl-von-Frisch Strasse, Marburg D-35043, Germany.,Marburg Center for Mind, Brain and Behavior, Philipps University, Marburg, Germany.,Institute for Neuro and Sensory Physiology, Heinrich Heine University, Düsseldorf D-40225, Germany
| | - Katja Nieweg
- Institute for Pharmacology and Clinical Pharmacy, Philipps University, Karl-von-Frisch Strasse, Marburg D-35043, Germany.,Marburg Center for Mind, Brain and Behavior, Philipps University, Marburg, Germany
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Patterns of Expression of Purinergic Receptor P2RY12, a Putative Marker for Non-Activated Microglia, in Aged and Alzheimer's Disease Brains. Int J Mol Sci 2020; 21:ijms21020678. [PMID: 31968618 PMCID: PMC7014248 DOI: 10.3390/ijms21020678] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 01/08/2023] Open
Abstract
Neuroinflammation is considered a key pathological process in neurodegenerative diseases of aging, including Alzheimer's disease (AD). Many studies have defined phenotypes of reactive microglia, the brain-resident macrophages, with different antigenic markers to identify those potentially causing inflammatory damage. We took an alternative approach with the goal of characterizing the distribution of purinergic receptor P2RY12-positive microglia, a marker previously defined as identifying homeostatic or non-activated microglia. We examined the expression of P2RY12 by dual-color light and fluorescence immunohistochemistry using sections of middle temporal gyrus from AD, high plaque and low plaque non-demented cases in relation to amyloid beta (Aβ) plaques and phosphorylated tau, markers of pathology, and HLA-DR, IBA-1, CD68, and progranulin, microglial phenotype markers. In low plaque cases, P2RY12-positive microglia mostly had non-activated morphologies, while the morphologies of P2RY12-positive microglia in AD brains were highly variable, suggesting its expression could encompass a wider range of phenotypes than originally hypothesized. P2RY12 expression by microglia differed depending on the types of plaques or tangles they were associated with. Areas of inflammation characterized by lack of P2RY12-positive microglia around mature plaques could be observed, but many diffuse plaques showed colocalization with P2RY12-positive microglia. Based on these results, P2RY12 expression by microglia should not be considered solely a marker of resting microglia as P2RY12 immunoreactivity was identifying microglia positive for CD68, progranulin and to a limited extent HLA-DR, markers of activation.
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Mendsaikhan A, Tooyama I, Bellier JP, Serrano GE, Sue LI, Lue LF, Beach TG, Walker DG. Characterization of lysosomal proteins Progranulin and Prosaposin and their interactions in Alzheimer's disease and aged brains: increased levels correlate with neuropathology. Acta Neuropathol Commun 2019; 7:215. [PMID: 31864418 PMCID: PMC6925443 DOI: 10.1186/s40478-019-0862-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 12/02/2019] [Indexed: 12/15/2022] Open
Abstract
Progranulin (PGRN) is a protein encoded by the GRN gene with multiple identified functions including as a neurotrophic factor, tumorigenic growth factor, anti-inflammatory cytokine and regulator of lysosomal function. A single mutation in the human GRN gene resulting in reduced PGRN expression causes types of frontotemporal lobar degeneration resulting in frontotemporal dementia. Prosaposin (PSAP) is also a multifunctional neuroprotective secreted protein and regulator of lysosomal function. Interactions of PGRN and PSAP affect their functional properties. Their roles in Alzheimer's disease (AD), the leading cause of dementia, have not been defined. In this report, we examined in detail the cellular expression of PGRN in middle temporal gyrus samples of a series of human brain cases (n = 45) staged for increasing plaque pathology. Immunohistochemistry showed PGRN expression in cortical neurons, microglia, cerebral vessels and amyloid beta (Aβ) plaques, while PSAP expression was mainly detected in neurons and Aβ plaques, and to a limited extent in astrocytes. We showed that there were increased levels of PGRN protein in AD cases and corresponding increased levels of PSAP. Levels of PGRN and PSAP protein positively correlated with amyloid beta (Aβ), with PGRN levels correlating with phosphorylated tau (serine 205) levels in these samples. Although PGRN colocalized with lysosomal-associated membrane protein-1 in neurons, most PGRN associated with Aβ plaques did not. Aβ plaques with PGRN and PSAP deposits were identified in the low plaque non-demented cases suggesting this was an early event in plaque formation. We did not observe PGRN-positive neurofibrillary tangles. Co-immunoprecipitation studies of PGRN from brain samples identified only PSAP associated with PGRN, not sortilin or other known PGRN-binding proteins, under conditions used. Most PGRN associated with Aβ plaques were immunoreactive for PSAP showing a high degree of colocalization of these proteins that did not change between disease groups. As PGRN supplementation has been considered as a therapeutic approach for AD, the possible involvement of PGRN and PSAP interactions in AD pathology needs to be further considered.
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Frost GR, Jonas LA, Li YM. Friend, Foe or Both? Immune Activity in Alzheimer's Disease. Front Aging Neurosci 2019; 11:337. [PMID: 31920620 PMCID: PMC6916654 DOI: 10.3389/fnagi.2019.00337] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is marked by the presence of amyloid beta (Aβ) plaques, neurofibrillary tangles (NFT), neuronal death and synaptic loss, and inflammation in the brain. AD research has, in large part, been dedicated to the understanding of Aβ and NFT deposition as well as to the pharmacological reduction of these hallmarks. However, recent GWAS data indicates neuroinflammation plays a critical role in AD development, thereby redirecting research efforts toward unveiling the complexities of AD-associated neuroinflammation. It is clear that the innate immune system is intimately associated with AD progression, however, the specific roles of glia and neuroinflammation in AD pathology remain to be described. Moreover, inflammatory processes have largely been painted as detrimental to AD pathology, when in fact, many immune mechanisms such as phagocytosis aid in the reduction of AD pathologies. In this review, we aim to outline the delicate balance between the beneficial and detrimental aspects of immune activation in AD as a more thorough understanding of these processes is critical to development of effective therapeutics for AD.
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Affiliation(s)
- Georgia R. Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
| | - Lauren A. Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
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Siddiqui SS, Matar R, Merheb M, Hodeify R, Vazhappilly CG, Marton J, Shamsuddin SA, Al Zouabi H. Siglecs in Brain Function and Neurological Disorders. Cells 2019; 8:E1125. [PMID: 31546700 PMCID: PMC6829431 DOI: 10.3390/cells8101125] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 12/14/2022] Open
Abstract
Siglecs (Sialic acid-binding immunoglobulin-type lectins) are a I-type lectin that typically binds sialic acid. Siglecs are predominantly expressed in immune cells and generate activating or inhibitory signals. They are also shown to be expressed on the surface of cells in the nervous system and have been shown to play central roles in neuroinflammation. There has been a plethora of reviews outlining the studies pertaining to Siglecs in immune cells. However, this review aims to compile the articles on the role of Siglecs in brain function and neurological disorders. In humans, the most abundant Siglecs are CD33 (Siglec-3), Siglec-4 (myelin-associated glycoprotein/MAG), and Siglec-11, Whereas in mice the most abundant are Siglec-1 (sialoadhesin), Siglec-2 (CD22), Siglec-E, Siglec-F, and Siglec-H. This review is divided into three parts. Firstly, we discuss the general biological aspects of Siglecs that are expressed in nervous tissue. Secondly, we discuss about the role of Siglecs in brain function and molecular mechanism for their function. Finally, we collate the available information on Siglecs and neurological disorders. It is intriguing to study this family of proteins in neurological disorders because they carry immunoinhibitory and immunoactivating motifs that can be vital in neuroinflammation.
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Affiliation(s)
- Shoib Sarwar Siddiqui
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | - Rachel Matar
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | - Maxime Merheb
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | - Rawad Hodeify
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | - Cijo George Vazhappilly
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | - John Marton
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
| | | | - Hussain Al Zouabi
- Department of Biotechnology, American University of Ras Al Khaimah (AURAK), Ras Al Khaimah 10021, UAE.
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Biber K, Bhattacharya A, Campbell BM, Piro JR, Rohe M, Staal RGW, Talanian RV, Möller T. Microglial Drug Targets in AD: Opportunities and Challenges in Drug Discovery and Development. Front Pharmacol 2019; 10:840. [PMID: 31507408 PMCID: PMC6716448 DOI: 10.3389/fphar.2019.00840] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/01/2019] [Indexed: 12/20/2022] Open
Abstract
Alzheimer’s disease (AD) is a large and increasing unmet medical need with no disease-modifying treatment currently available. Genetic evidence from genome-wide association studies (GWASs) and gene network analysis has clearly revealed a key role of the innate immune system in the brain, of which microglia are the most important element. Single-nucleotide polymorphisms (SNPs) in genes predominantly expressed in microglia have been associated with altered risk of developing AD. Furthermore, microglia-specific pathways are affected on the messenger RNA (mRNA) expression level in post-mortem AD tissue and in mouse models of AD. Together these findings have increased the interest in microglia biology, and numerous scientific reports have proposed microglial molecules and pathways as drug targets for AD. Target identification and validation are generally the first steps in drug discovery. Both target validation and drug lead identification for central nervous system (CNS) targets and diseases entail additional significant obstacles compared to peripheral targets and diseases. This makes CNS drug discovery, even with well-validated targets, challenging. In this article, we will illustrate the special challenges of AD drug discovery by discussing the viability/practicality of possible microglia drug targets including cluster of differentiation 33 (CD33), KCa3.1, kynurenines, ionotropic P2 receptor 7 (P2X7), programmed death-1 (PD-1), Toll-like receptors (TLRs), and triggering receptor expressed in myeloid cells 2 (TREM2).
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Affiliation(s)
- Knut Biber
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Research, Ludwigshafen, Germany
| | | | | | - Justin R Piro
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
| | - Michael Rohe
- AbbVie Deutschland GmbH & Co. KG, Neuroscience Research, Ludwigshafen, Germany
| | | | - Robert V Talanian
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
| | - Thomas Möller
- AbbVie Foundational Neuroscience Center, Cambridge, MA, United States
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Lue LF, Beach TG, Walker DG. Alzheimer's Disease Research Using Human Microglia. Cells 2019; 8:cells8080838. [PMID: 31387311 PMCID: PMC6721636 DOI: 10.3390/cells8080838] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Experimental studies of neuroinflammation in Alzheimer's disease (AD) have mostly investigated microglia, the brain-resident macrophages. This review focused on human microglia obtained at rapid autopsies. Studies employing methods to isolate and culture human brain microglia in high purity for experimental studies were discussed. These methods were employed to isolate human microglia for investigation of a number of features of neuroinflammation, including activation phenotypes, neurotoxicity, responses to abnormal aggregated proteins such as amyloid beta, phagocytosis, and the effects of aging and disease on microglia cellular properties. In recent years, interest in human microglia and neuroinflammation has been renewed due to the identification of inflammation-related AD genetic risk factors, in particular the triggering receptor expressed on myeloid cells (TREM)-2. Because of the difficulties in developing effective treatments for AD, there has been a general need for greater understanding of the functions of microglia in normal and AD brains. While most experimental studies on neuroinflammation have employed rodent microglia, this review considered the role of human microglia in experimental studies. This review focused on the development of in vitro methodology for the culture of postmortem human microglia and the key findings obtained from experimental studies with these cells.
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Affiliation(s)
- Lih-Fen Lue
- Banner Sun Health Research Institute, Sun City, AZ, 85351, USA.
- Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ 84027, USA.
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun City, AZ, 85351, USA
| | - Douglas G Walker
- Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ 84027, USA
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu 520, Japan
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40
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Estus S, Shaw BC, Devanney N, Katsumata Y, Press EE, Fardo DW. Evaluation of CD33 as a genetic risk factor for Alzheimer's disease. Acta Neuropathol 2019; 138:187-199. [PMID: 30949760 PMCID: PMC7035471 DOI: 10.1007/s00401-019-02000-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/22/2019] [Accepted: 03/30/2019] [Indexed: 12/23/2022]
Abstract
In 2011, genome-wide association studies implicated a polymorphism near CD33 as a genetic risk factor for Alzheimer's disease. This finding sparked interest in this member of the sialic acid-binding immunoglobulin-type lectin family which is linked to innate immunity. Subsequent studies found that CD33 is expressed in microglia in the brain and then investigated the molecular mechanism underlying the CD33 genetic association with Alzheimer's disease. The allele that protects from Alzheimer's disease acts predominately to increase a CD33 isoform lacking exon 2 at the expense of the prototypic, full-length CD33 that contains exon 2. Since this exon encodes the sialic acid ligand-binding domain, the finding that the loss of exon 2 was associated with decreased Alzheimer's disease risk was interpreted as meaning that a decrease in functional CD33 and its associated immune suppression was protective from Alzheimer's disease. However, this interpretation may need to be reconsidered given current findings that a genetic deletion which abrogates CD33 is not associated with Alzheimer's disease risk. Therefore, integrating currently available findings leads us to propose a model wherein the CD33 isoform lacking the ligand-binding domain represents a gain of function variant that reduces Alzheimer's disease risk.
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Affiliation(s)
- Steven Estus
- Department of Physiology and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.
| | - Benjamin C Shaw
- Department of Physiology and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Nicholas Devanney
- Department of Physiology and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Yuriko Katsumata
- Department of Biostatistics and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | | | - David W Fardo
- Department of Biostatistics and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
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Microglial Phenotyping in Neurodegenerative Disease Brains: Identification of Reactive Microglia with an Antibody to Variant of CD105/Endoglin. Cells 2019; 8:cells8070766. [PMID: 31340569 PMCID: PMC6678308 DOI: 10.3390/cells8070766] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/11/2019] [Accepted: 07/17/2019] [Indexed: 12/14/2022] Open
Abstract
Inflammation is considered a key pathological process in neurodegenerative diseases, including Alzheimer’s disease (AD) and Parkinson’s disease (PD), but there are still mechanisms not understood. In the brain, most microglia are performing essential homeostatic functions, but can also respond to pathogenic stimuli by producing harmful pro-inflammatory cytokines or free radicals. Distinguishing between damaging and homeostatic microglia in human diseased brain tissues is a challenge. This report describes findings using a monoclonal antibody to CD105/Endoglin (R&D Systems MAB1097) that identifies subtypes of activated microglia. CD105/Endoglin is a co-receptor for transforming growth factor beta (TGFβ) receptor that antagonizes TGFβ signaling. CD105/Endoglin is a marker for vascular endothelial cells, but was originally identified as a marker for activated macrophages. This antibody did not identify endothelial cells in brain sections, only microglia-like cells. In this study, we examined with this antibody tissue section from middle temporal gyrus derived from human brains from normal control subjects with low-plaque pathology, high-plaque pathology, and AD cases, and also substantia nigra samples from control and PD cases, in conjunction with antibodies to markers of pathology and microglia. In low-plaque pathology cases, CD105-positive microglia were mostly absent, but noticeably increased with increasing pathology. CD105-positive cells strongly colocalized with amyloid-beta plaques, but not phosphorylated tau positive tangles. In substantia nigra, strong microglial CD105 staining was observed in microglia associated with degenerating dopaminergic neurons and neuromelanin. In PD cases with few surviving dopaminergic neurons, this staining had decreased. By Western blot, this antibody identified polypeptide bands of 70 kDa in brain samples, and samples from microglia, macrophages, and brain endothelial cells. In comparison with other tested CD105 antibodies, this antibody did not recognize the glycosylated forms of CD105 on Western blots. Overall, the data indicate that this antibody and this marker could have utility for subtyping of microglia in pathologically-involved tissue.
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Miles LA, Hermans SJ, Crespi GAN, Gooi JH, Doughty L, Nero TL, Markulić J, Ebneth A, Wroblowski B, Oehlrich D, Trabanco AA, Rives ML, Royaux I, Hancock NC, Parker MW. Small Molecule Binding to Alzheimer Risk Factor CD33 Promotes Aβ Phagocytosis. iScience 2019; 19:110-118. [PMID: 31369984 PMCID: PMC6669322 DOI: 10.1016/j.isci.2019.07.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 01/16/2019] [Accepted: 07/15/2019] [Indexed: 02/06/2023] Open
Abstract
Polymorphism in the microglial receptor CD33 gene has been linked to late-onset Alzheimer disease (AD), and reduced expression of the CD33 sialic acid-binding domain confers protection. Thus, CD33 inhibition might be an effective therapy against disease progression. Progress toward discovery of selective CD33 inhibitors has been hampered by the absence of an atomic resolution structure. We report here the crystal structures of CD33 alone and bound to a subtype-selective sialic acid mimetic called P22 and use them to identify key binding residues by site-directed mutagenesis and binding assays to reveal the molecular basis for its selectivity toward sialylated glycoproteins and glycolipids. We show that P22, when presented on microparticles, increases uptake of the toxic AD peptide, amyloid-β (Aβ), into microglial cells. Thus, the sialic acid-binding site on CD33 is a promising pharmacophore for developing therapeutics that promote clearance of the Aβ peptide that is thought to cause AD.
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Affiliation(s)
- Luke A Miles
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia.
| | - Stefan J Hermans
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Gabriela A N Crespi
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jonathan H Gooi
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Larissa Doughty
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Tracy L Nero
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jasmina Markulić
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Andreas Ebneth
- Janssen Research & Development, a Division of Janssen Pharmaceutica N.V, 2340 Beerse, Belgium
| | - Berthold Wroblowski
- Janssen Research & Development, a Division of Janssen Pharmaceutica N.V, 2340 Beerse, Belgium
| | - Daniel Oehlrich
- Janssen Research & Development, a Division of Janssen Pharmaceutica N.V, 2340 Beerse, Belgium
| | - Andrés A Trabanco
- Neuroscience Medicinal Chemistry, Janssen Research & Development, 45007 Toledo, Spain
| | - Marie-Laure Rives
- Molecular and Cellular Pharmacology, Janssen Research & Development, LLC, La Jolla, CA 92121, USA
| | - Ines Royaux
- Janssen Research & Development, a Division of Janssen Pharmaceutica N.V, 2340 Beerse, Belgium
| | - Nancy C Hancock
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael W Parker
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3056, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010, Australia.
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Griciuc A, Patel S, Federico AN, Choi SH, Innes BJ, Oram MK, Cereghetti G, McGinty D, Anselmo A, Sadreyev RI, Hickman SE, El Khoury J, Colonna M, Tanzi RE. TREM2 Acts Downstream of CD33 in Modulating Microglial Pathology in Alzheimer's Disease. Neuron 2019; 103:820-835.e7. [PMID: 31301936 DOI: 10.1016/j.neuron.2019.06.010] [Citation(s) in RCA: 204] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 05/15/2019] [Accepted: 06/12/2019] [Indexed: 12/13/2022]
Abstract
The microglial receptors CD33 and TREM2 have been associated with risk for Alzheimer's disease (AD). Here, we investigated crosstalk between CD33 and TREM2. We showed that knockout of CD33 attenuated amyloid beta (Aβ) pathology and improved cognition in 5xFAD mice, both of which were abrogated by additional TREM2 knockout. Knocking out TREM2 in 5xFAD mice exacerbated Aβ pathology and neurodegeneration but reduced Iba1+ cell numbers, all of which could not be rescued by additional CD33 knockout. RNA-seq profiling of microglia revealed that genes related to phagocytosis and signaling (IL-6, IL-8, acute phase response) are upregulated in 5xFAD;CD33-/- and downregulated in 5xFAD;TREM2-/- mice. Differential gene expression in 5xFAD;CD33-/- microglia depended on the presence of TREM2, suggesting TREM2 acts downstream of CD33. Crosstalk between CD33 and TREM2 includes regulation of the IL-1β/IL-1RN axis and a gene set in the "receptor activity chemokine" cluster. Our results should facilitate AD therapeutics targeting these receptors.
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Affiliation(s)
- Ana Griciuc
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Shaun Patel
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Anthony N Federico
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Se Hoon Choi
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Brendan J Innes
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Mary K Oram
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Gea Cereghetti
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Institute of Biochemistry, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Danielle McGinty
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Anthony Anselmo
- Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Ruslan I Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Suzanne E Hickman
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Joseph El Khoury
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, Mass General Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
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Gong L, Xu R, Lan L, Liu D, Shen J, Zhang B. The CD33 genotype associated cognitive performance was bidirectionally modulated by intrinsic functional connectivity in the Alzheimer’s disease spectrum. Biomed Pharmacother 2019; 115:108903. [DOI: 10.1016/j.biopha.2019.108903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 04/10/2019] [Accepted: 04/22/2019] [Indexed: 12/26/2022] Open
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Mehdizadeh E, Khalaj-Kondori M, Shaghaghi-Tarakdari Z, Sadigh-Eteghad S, Talebi M, Andalib S. Association of MS4A6A, CD33, and TREM2 gene polymorphisms with the late-onset Alzheimer's disease. ACTA ACUST UNITED AC 2019; 9:219-225. [PMID: 31799158 PMCID: PMC6879710 DOI: 10.15171/bi.2019.27] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/22/2019] [Accepted: 04/09/2019] [Indexed: 12/14/2022]
Abstract
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Introduction: Alzheimer’s disease (AD), which is a progressive neurodegenerative disorder, causes structural and functional brain disruption. MS4A6A, TREM2, and CD33 gene polymorphisms loci have been found to be associated with the pathobiology of late-onset AD (LOAD). In the present study, we tested the hypothesis of association of LOAD with rs983392, rs75932628, and rs3865444 polymorphisms in MS4A6A, TREM2, CD33 genes, respectively.
Methods: In the present study, 113 LOAD patients and 100 healthy unrelated age- and gender-matched controls were selected. DNA was extracted from blood samples by the salting-out method and the genotyping was performed by RFLP-PCR. Electrophoresis was carried out on agarose gel. Sequencing was thereafter utilized for the confirmation of the results.
Results: Only CD33 rs3865444 polymorphism revealed a significant difference in the genotypic frequencies of GG (P = 0.001) and GT (P = 0.001), and allelic frequencies of G (P = 0.033) and T (P = 0.03) between LOAD patients and controls.
Conclusion: The evidence from the present study suggests that T allele of CD33 rs3865444 polymorphism is associated with LOAD in the studied Iranian population.
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Affiliation(s)
- Elham Mehdizadeh
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Zeinab Shaghaghi-Tarakdari
- Department of Genetics, Animal Biology Group, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Saeed Sadigh-Eteghad
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahnaz Talebi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sasan Andalib
- Neuroscience Research Center, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran.,Department of Neurosurgery, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.,Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark.,Center for Applied Neuroscience, Brain Research - Interdisciplinary Guided Excellence, BRIDGE, Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark.,Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark.,Department of Psychiatry, Psychiatry in the Region of Southern Denmark, Odense, Denmark
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Walker DG, Tang TM, Lue LF. Increased expression of toll-like receptor 3, an anti-viral signaling molecule, and related genes in Alzheimer's disease brains. Exp Neurol 2018; 309:91-106. [PMID: 30076830 PMCID: PMC6151184 DOI: 10.1016/j.expneurol.2018.07.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/28/2018] [Accepted: 07/29/2018] [Indexed: 01/28/2023]
Abstract
The focus of this study is the expression of Toll-like receptor-3 (TLR-3), a receptor for double-stranded RNA, in human brains affected by Alzheimer's disease (AD) pathology. Toll-like receptors are a family of pattern recognition molecules primarily involved in host defenses to microbial pathogens, but roles in neurodegenerative disease have also been shown, as amyloid beta (Aβ) can be a ligand for TLR-2 and -4 and α-synuclein for TLR-1 and TLR-2, while TLR-9 activation promotes Aβ removal. However, involvement of TLR-3 in AD has not been rigorously studied. Immunohistochemical analyses in human temporal cortical sections with a validated antibody for TLR-3 predominantly identified microglia, particularly strongly in cells associated with amyloid plaques, also brain vascular endothelial cells and subsets of astrocytes, but not neurons or p62-immunoreactive structures. Microglial TLR-3 colocalized with the endosomal/lysosomal marker CD68, which identifies phagocytic cells. Quantitative analyses of neuropathologically-staged human brain middle temporal gyrus samples using immunohistochemistry and mRNA expression methods demonstrated increased TLR-3 immunoreactivity and increased TLR-3 mRNA in AD compared to non-demented cases. There were significant positive correlations between TLR-3 mRNA levels and plaque or tangle loads in both series of samples. Increased expression of interferon beta (IFN-β) and interferon regulatory factor (IRF)-3 mRNA, two factors induced by TLR-3 signaling, were detected in the AD cases. Increased expression of TLR-4 and TLR-9 mRNA was also observed in these same samples, but not TLR-2. In vitro cultured human brain microglia responses to Aβ inflammatory activation were not altered by TLR-3 activation with activator polyinosinic;polycytidylic acid (poly I:C), while human brain endothelial cells showed reduction in responses when stimulated with both agents. Treatment of microglia with poly I:C did not increase their uptake and breakdown of Aβ.
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Affiliation(s)
- Douglas G Walker
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Japan; Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, Arizona, USA; Banner Sun Health Research Institute, Sun City, Arizona, USA.
| | - Tiffany M Tang
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Lih-Fen Lue
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, Arizona, USA; Banner Sun Health Research Institute, Sun City, Arizona, USA
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Newcombe EA, Camats-Perna J, Silva ML, Valmas N, Huat TJ, Medeiros R. Inflammation: the link between comorbidities, genetics, and Alzheimer's disease. J Neuroinflammation 2018; 15:276. [PMID: 30249283 PMCID: PMC6154824 DOI: 10.1186/s12974-018-1313-3] [Citation(s) in RCA: 333] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder, most cases of which lack a clear causative event. This has made the disease difficult to characterize and, thus, diagnose. Although some cases are genetically linked, there are many diseases and lifestyle factors that can lead to an increased risk of developing AD, including traumatic brain injury, diabetes, hypertension, obesity, and other metabolic syndromes, in addition to aging. Identifying common factors and trends between these conditions could enhance our understanding of AD and lead to the development of more effective treatments. Although the immune system is one of the body’s key defense mechanisms, chronic inflammation has been increasingly linked with several age-related diseases. Moreover, it is now well accepted that chronic inflammation has an important role in the onset and progression of AD. In this review, the different inflammatory signals associated with AD and its risk factors will be outlined to demonstrate how chronic inflammation may be influencing individual susceptibility to AD. Our goal is to bring attention to potential shared signals presented by the immune system during different conditions that could lead to the development of successful treatments.
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Affiliation(s)
- Estella A Newcombe
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.
| | - Judith Camats-Perna
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia
| | - Mallone L Silva
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia
| | - Nicholas Valmas
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Tee Jong Huat
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.,Centre for Stem Cell Ageing and Regenerative Engineering, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Rodrigo Medeiros
- Neurula Laboratory, Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Building 79, Brisbane, 4072, QLD, Australia.
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Jiang YT, Li HY, Cao XP, Tan L. Meta-analysis of the association between CD33 and Alzheimer's disease. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:169. [PMID: 29951491 DOI: 10.21037/atm.2018.04.21] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background The cluster of differentiation 33 (CD33) gene is compelling among the susceptibility genes of Alzheimer's disease (AD) in Genome-wide association study (GWAS). Researches of the relationship between AD and polymorphism in CD33 have showed conflicting results. In order to more precisely evaluate whether CD33 variants are associated with AD, we performed the meta-analysis presented in this manuscript. Methods We searched from three databases including PubMed, Cochrane library and EMbase for related case-control researches based on criteria of determination. A total of 18 case-control studies, containing 50,030 cases and 77,405 controls were involved in CD33 rs3865444 polymorphism. And a total of 4 case-control studies, containing 826 cases and 984 controls were involved in CD33 rs3826656 polymorphism. Results This study demonstrated that different variants in CD33 were associated with AD (rs3865444: OR =0.94; 95% CI, 0.90-0.98, P<0.01; rs3826656: OR =0.94; 95% CI, 0.62-1.41, P<0.01). We made subgroup analysis which was stratified by race. There were protective associations in Caucasians but not in Asians among CD33 rs3865444 polymorphism (Caucasians: OR =0.92; 95% CI, 0.90-0.94, P=0.05; Asians: OR =0.87; 95% CI, 0.65-1.17, P<0.01). Conclusions The CD33 rs3865444 polymorphism could be a protective factor in AD. Meanwhile, there was no association between the CD33 rs3826656 polymorphism and AD. Further confirmation is needed in larger and better-designed researches.
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Affiliation(s)
- Yu-Ting Jiang
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao 266071, China
| | - Hai-Yan Li
- Department of Neurology, Weihai Wei People's Hospital, Weihai 264200, China
| | - Xi-Peng Cao
- Clinical Research Center, Qingdao Municipal Hospital, Qingdao University, Qingdao 266071, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao 266071, China
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Abstract
Alzheimer's disease (AD), the main form of dementia in the elderly, is the most common progressive neurodegenerative disease characterized by rapidly progressive cognitive dysfunction and behavior impairment. AD exhibits a considerable heritability and great advances have been made in approaches to searching the genetic etiology of AD. In AD genetic studies, methods have developed from classic linkage-based and candidate-gene-based association studies to genome-wide association studies (GWAS) and next generation sequencing (NGS). The identification of new susceptibility genes has provided deeper insights to understand the mechanisms underlying AD. In addition to searching novel genes associated with AD in large samples, the NGS technologies can also be used to shed light on the 'black matter' discovery even in smaller samples. The shift in AD genetics between traditional studies and individual sequencing will allow biomaterials of each patient as the central unit of genetic studies. This review will cover genetic findings in AD and consequences of AD genetic findings. Firstly, we will discuss the discovery of mutations in APP, PSEN1, PSEN2, APOE, and ADAM10. Then we will summarize and evaluate the information obtained from GWAS of AD. Finally, we will outline the efforts to identify rare variants associated with AD using NGS.
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Hopperton KE, Mohammad D, Trépanier MO, Giuliano V, Bazinet RP. Markers of microglia in post-mortem brain samples from patients with Alzheimer's disease: a systematic review. Mol Psychiatry 2018; 23:177-198. [PMID: 29230021 PMCID: PMC5794890 DOI: 10.1038/mp.2017.246] [Citation(s) in RCA: 307] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/15/2017] [Accepted: 09/14/2017] [Indexed: 02/07/2023]
Abstract
Neuroinflammation is proposed as one of the mechanisms by which Alzheimer's disease pathology, including amyloid-β plaques, leads to neuronal death and dysfunction. Increases in the expression of markers of microglia, the main neuroinmmune cell, are widely reported in brains from patients with Alzheimer's disease, but the literature has not yet been systematically reviewed to determine whether this is a consistent pathological feature. A systematic search was conducted in Medline, Embase and PsychINFO for articles published up to 23 February 2017. Papers were included if they quantitatively compared microglia markers in post-mortem brain samples from patients with Alzheimer's disease and aged controls without neurological disease. A total of 113 relevant articles were identified. Consistent increases in markers related to activation, such as major histocompatibility complex II (36/43 studies) and cluster of differentiation 68 (17/21 studies), were identified relative to nonneurological aged controls, whereas other common markers that stain both resting and activated microglia, such as ionized calcium-binding adaptor molecule 1 (10/20 studies) and cluster of differentiation 11b (2/5 studies), were not consistently elevated. Studies of ionized calcium-binding adaptor molecule 1 that used cell counts almost uniformly identified no difference relative to control, indicating that increases in activation occurred without an expansion of the total number of microglia. White matter and cerebellum appeared to be more resistant to these increases than other brain regions. Nine studies were identified that included high pathology controls, patients who remained free of dementia despite Alzheimer's disease pathology. The majority (5/9) of these studies reported higher levels of microglial markers in Alzheimer's disease relative to controls, suggesting that these increases are not solely a consequence of Alzheimer's disease pathology. These results show that increased markers of microglia are a consistent feature of Alzheimer's disease, though this seems to be driven primarily by increases in activation-associated markers, as opposed to markers of all microglia.
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Affiliation(s)
- K E Hopperton
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - D Mohammad
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada,Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - M O Trépanier
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - V Giuliano
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - R P Bazinet
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, FitzGerald Building, 150 College Street, Room 306, Toronto, ON M5S 3E2, Canada. E-mail:
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