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Fitz NF, Wolfe CM, Playso BE, Biedrzycki RJ, Lu Y, Nam KN, Lefterov I, Koldamova R. Trem2 deficiency differentially affects phenotype and transcriptome of human APOE3 and APOE4 mice. Mol Neurodegener 2020; 15:41. [PMID: 32703241 PMCID: PMC7379780 DOI: 10.1186/s13024-020-00394-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/16/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Alzheimer's Disease (AD) is a neurodegenerative disorder influenced by aging and genetic risk factors. The inheritance of APOEε4 and variants of Triggering Receptor Expressed on Myeloid cells 2 (TREM2) are major genetic risk factors for AD. Recent studies showed that APOE binds to TREM2, thus raising the possibility of an APOE-TREM2 interaction that can modulate AD pathology. METHODS The aim of this study was to investigate this interaction using complex AD model mice - a crossbreed of Trem2ko and APP/PSEN1dE9 mice expressing human APOE3 or APOE4 isoforms (APP/E3 and APP/E4 respectively), and their WT littermates (E3 and E4), and evaluate cognition, steady-state amyloid load, plaque compaction, plaque growth rate, glial response, and brain transcriptome. RESULTS In both, APP/E3 and APP/E4 mice, Trem2 deletion reduced plaque compaction but did not significantly affect steady-state plaque load. Importantly, the lack of TREM2 increased plaque growth that negatively correlated to the diminished microglia barrier, an effect most pronounced at earlier stages of amyloid deposition. We also found that Trem2 deficiency significantly decreased plaque-associated APOE protein in APP/E4 but not in APP/E3 mice in agreement with RNA-seq data. Interestingly, we observed a significant decrease of Apoe mRNA expression in plaque-associated microglia of APP/E4/Trem2ko vs APP/E4 mice. The absence of TREM2, worsened cognitive performance in APP transgenic mice but not their WT littermates. Gene expression analysis identified Trem2 signature - a cluster of highly connected immune response genes, commonly downregulated as a result of Trem2 deletion in all genotypes including APP and WT littermates. Furthermore, we identified sets of genes that were affected in TREM2- and APOE isoform-dependent manner. Among them were Clec7a and Csf1r upregulated in APP/E4 vs APP/E3 mice, a result further validated by in situ hybridization analysis. In contrast, Tyrobp and several genes involved in the C1Q complement cascade had a higher expression level in APP/E3 versus their APP/E4 counterparts. CONCLUSIONS Our data demonstrate that lack of Trem2 differentially impacts the phenotype and brain transcriptome of APP mice expressing human APOE isoforms. The changes probably reflect the different effect of APOE isoforms on amyloid deposition.
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Affiliation(s)
- Nicholas F. Fitz
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Cody M. Wolfe
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Brittany E. Playso
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Richard J. Biedrzycki
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Yi Lu
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Kyong Nyon Nam
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Iliya Lefterov
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
| | - Radosveta Koldamova
- Department of Environmental & Occupational Health, University of Pittsburgh, 130 De Soto Street, Pittsburgh, PA 15261 USA
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152
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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: 150] [Impact Index Per Article: 37.5] [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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153
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Yang J, Fu Z, Zhang X, Xiong M, Meng L, Zhang Z. TREM2 ectodomain and its soluble form in Alzheimer's disease. J Neuroinflammation 2020; 17:204. [PMID: 32635934 PMCID: PMC7341574 DOI: 10.1186/s12974-020-01878-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a receptor mainly expressed on the surface of microglia. It mediates multiple pathophysiological processes in various diseases. Recently, TREM2 has been found to play a role in the development of Alzheimer's disease (AD). TREM2 is a transmembrane protein that is specifically expressed on microglia in the brain. It contains a long ectodomain that directly interacts with the extracellular environment to regulate microglial function. The ectodomain of TREM2 is processed by a disintegrin and metalloprotease, resulting in the release of a soluble form of TREM2 (sTREM2). Recent studies have demonstrated that sTREM2 is a bioactive molecule capable of binding ligands, activating microglia, and regulating immune responses during the AD continuum. Clinical studies revealed that sTREM2 level is elevated in cerebrospinal fluid (CSF) of AD patients, and the sTREM2 level is positively correlated with the levels of classical CSF biomarkers, namely t-tau and p-tau, indicating that it is a reliable predictor of the early stages of AD. Herein, we summarize the key results on the generation, structure, and function of sTREM2 to provide new insights into TREM2-related mechanisms underlying AD pathogenesis and to promote the development of TREM2-based therapeutic strategy.
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Affiliation(s)
- Jiaolong Yang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhihui Fu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Xingyu Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Min Xiong
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
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154
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TREM2 Overexpression Attenuates Cognitive Deficits in Experimental Models of Vascular Dementia. Neural Plast 2020; 2020:8834275. [PMID: 32617097 PMCID: PMC7306072 DOI: 10.1155/2020/8834275] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/09/2020] [Accepted: 05/28/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroinflammation plays a prominent role in the pathogenesis of vascular dementia (VD). Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor mainly expressed on microglia and has been known for its anti-inflammatory properties during immune response. However, data evaluating the effects of TREM2 in VD are lacking. Therefore, the present study is aimed at investigating the role of TREM2 in VD. In this study, the mouse model of VD was induced by transient bilateral common carotid artery occlusion (BCCAO). We compared the hippocampal gene and protein expressions of TREM2 between the VD mice and sham-operated mice at different time points. The TREM2 mRNA and protein expression levels in the VD mice were higher than those in the sham-operated mice. The cognitive deficits of VD mice were observed in the Morris water maze test. Interestingly, overexpression of TREM2 by intracerebroventricular injection of a lentiviral vector that encoded TREM2 (LV-TREM2) significantly improved the spatial learning and memory and attenuated the hippocampal neural loss in VD mice. Further mechanistic study revealed that overexpression of TREM2 significantly inhibited microglia M1 polarization by decreasing inducible nitric oxide synthase (iNOS) and proinflammatory cytokines expression levels and conversely enhanced microglia M2 polarization by increasing Arginase-1 (Arg-1) and anti-inflammatory cytokine expression levels. These results strongly suggest that TREM2 provides a protective effect in VD via modulating the phenotype of activated microglia and may serve as a novel potential therapeutic target for VD.
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155
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Schwabe T, Srinivasan K, Rhinn H. Shifting paradigms: The central role of microglia in Alzheimer's disease. Neurobiol Dis 2020; 143:104962. [PMID: 32535152 DOI: 10.1016/j.nbd.2020.104962] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 05/01/2020] [Accepted: 06/10/2020] [Indexed: 12/31/2022] Open
Abstract
Recent human genetic studies have challenged long standing hypotheses about the chain of events in Alzheimer's disease (AD), as the identification of genetic risk factors in microglial genes supports a causative role for microglia in the disease. Parallel transcriptome and histology studies at the single-cell level revealed a rich palette of microglial states affected by disease status and genetic risk factors. Taken together, those findings support microglia dysfunction as a central mechanism in AD etiology and thus the therapeutic potential of modulating microglial activity for AD treatment. Here we review how human genetic studies discovered microglial AD risk genes, such as TREM2, CD33, MS4A and APOE, and how experimental studies are beginning to decipher the cellular functions of some of these genes. Our review also focuses on recent transcriptomic studies of human microglia from postmortem tissue to critically assess areas of similarity and dissimilarity between human and mouse models currently in use in order to better understand the biology of innate immunity in AD.
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156
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Deczkowska A, Weiner A, Amit I. The Physiology, Pathology, and Potential Therapeutic Applications of the TREM2 Signaling Pathway. Cell 2020; 181:1207-1217. [DOI: 10.1016/j.cell.2020.05.003] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/15/2020] [Accepted: 04/30/2020] [Indexed: 12/20/2022]
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157
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Yuan C, Aierken A, Xie Z, Li N, Zhao J, Qing H. The age-related microglial transformation in Alzheimer's disease pathogenesis. Neurobiol Aging 2020; 92:82-91. [PMID: 32408056 DOI: 10.1016/j.neurobiolaging.2020.03.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/11/2020] [Accepted: 03/31/2020] [Indexed: 12/15/2022]
Abstract
Neuroinflammatory responses mediated by microglia, the resident immune cells of the central nervous system, have long been a subject of study in the field of Alzheimer's disease (AD). Microglia express a wide range of receptors that act as molecular sensors, through which they can fulfill their various functions. In this review, we first analyzed the changes in the expression levels of microglial membrane receptors SR-A, TREM2, CD36, CD33, and CR3 in aging and AD and described the different roles of these receptors in amyloid-beta clearance and inflammatory responses. Two classical hallmarks of AD are extracellular amyloid-beta deposits and intracellular aggregated phosphorylated tau. In AD, microglia reaction was initially thought to be triggered by amyloid deposits. New evidence showed it also associated with increased phosphorylation of tau. However, which first appeared and induced activated microglia is not clear. Then we summarized diverse opinions on it. Besides, as AD is tightly linked to aging, and microglia changes dramatically on aging, yet the relative impacts of both aging and microglia are less frequently considered, so at last, we discussed the roles of aging microglia in AD. We hope to provide a reference for subsequent research.
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Affiliation(s)
- Chunxu Yuan
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biological Sciences, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Ailikemu Aierken
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biological Sciences, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhen Xie
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biological Sciences, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Nuomin Li
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biological Sciences, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Juan Zhao
- School of Materials Science and Engineering, Department of Materials Processing Engineering, Beijing Institute of Technology, Beijing, China.
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, Department of Biological Sciences, School of Life Science, Beijing Institute of Technology, Beijing, China.
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158
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New fluid biomarkers tracking non-amyloid-β and non-tau pathology in Alzheimer's disease. Exp Mol Med 2020; 52:556-568. [PMID: 32284537 PMCID: PMC7210893 DOI: 10.1038/s12276-020-0418-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 01/19/2023] Open
Abstract
Cerebrospinal fluid (CSF) biomarkers based on the core pathological proteins associated with Alzheimer’s disease (AD), i.e., amyloid-β (Aβ) and tau protein, are widely regarded as useful diagnostic biomarkers. However, a lack of biomarkers for monitoring the treatment response and indexing clinical severity has proven to be problematic in drug trials targeting Aβ. Therefore, new biomarkers are needed to track non-Aβ and non-tau pathology. Many proteins involved in the pathophysiological progression of AD have shown promise as new biomarkers. Neurodegeneration- and synapse-related biomarkers in CSF (e.g., neurofilament light polypeptide [NFL], neurogranin, and visinin-like protein 1) and blood (e.g., NFL) aid prediction of AD progress, as well as early diagnosis. Neuroinflammation, lipid dysmetabolism, and impaired protein clearance are considered important components of AD pathophysiology. Inflammation-related proteins in the CSF, such as progranulin, intercellular adhesion molecule 1, and chitinase-3-like protein 1 (YKL-40), are useful for the early detection of AD and can represent clinical severity. Several lipid metabolism-associated biomarkers and protein clearance-linked markers have also been suggested as candidate AD biomarkers. Combinations of subsets of new biomarkers enhance their utility in terms of broadly characterizing AD-associated pathological changes, thereby facilitating precise selection of susceptible patients and comprehensive monitoring of the treatment response. This approach could facilitate the development of effective treatments for AD. Finding new biomarkers for Alzheimer’s disease (AD) may help in tracking disease progression and identifying optimal patient-specific treatments. Although useful markers are available for diagnosis of AD, they are unreliable for tracking disease progression. Looking for better ways to track disease progression, Sun Ah Park at the Ajou University School of Medicine, Suwon, South Korea, and coworkers have reviewed alternative AD markers. They report that several markers for axonal degeneration, synaptic loss, brain inflammation and lipid metabolism show promise for tracking AD. Some of these markers can be obtained from blood samples, which are minimally invasive to collect. Use of combinations of markers is especially promising for estimating a patient’s disease stage. These results will contribute to developing tailored treatments for this common cause of dementia.
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159
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Schlepckow K, Monroe KM, Kleinberger G, Cantuti‐Castelvetri L, Parhizkar S, Xia D, Willem M, Werner G, Pettkus N, Brunner B, Sülzen A, Nuscher B, Hampel H, Xiang X, Feederle R, Tahirovic S, Park JI, Prorok R, Mahon C, Liang C, Shi J, Kim DJ, Sabelström H, Huang F, Di Paolo G, Simons M, Lewcock JW, Haass C. Enhancing protective microglial activities with a dual function TREM2 antibody to the stalk region. EMBO Mol Med 2020; 12:e11227. [PMID: 32154671 PMCID: PMC7136959 DOI: 10.15252/emmm.201911227] [Citation(s) in RCA: 147] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 02/12/2020] [Accepted: 02/17/2020] [Indexed: 01/07/2023] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is essential for the transition of homeostatic microglia to a disease-associated microglial state. To enhance TREM2 activity, we sought to selectively increase the full-length protein on the cell surface via reducing its proteolytic shedding by A Disintegrin And Metalloproteinase (i.e., α-secretase) 10/17. We screened a panel of monoclonal antibodies against TREM2, with the aim to selectively compete for α-secretase-mediated shedding. Monoclonal antibody 4D9, which has a stalk region epitope close to the cleavage site, demonstrated dual mechanisms of action by stabilizing TREM2 on the cell surface and reducing its shedding, and concomitantly activating phospho-SYK signaling. 4D9 stimulated survival of macrophages and increased microglial uptake of myelin debris and amyloid β-peptide in vitro. In vivo target engagement was demonstrated in cerebrospinal fluid, where nearly all soluble TREM2 was 4D9-bound. Moreover, in a mouse model for Alzheimer's disease-related pathology, 4D9 reduced amyloidogenesis, enhanced microglial TREM2 expression, and reduced a homeostatic marker, suggesting a protective function by driving microglia toward a disease-associated state.
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Affiliation(s)
- Kai Schlepckow
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
| | | | - Gernot Kleinberger
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
- Present address:
ISAR Bioscience GmbHPlaneggGermany
| | | | - Samira Parhizkar
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Dan Xia
- Denali Therapeutics Inc.South San FranciscoCAUSA
| | - Michael Willem
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Georg Werner
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Nadine Pettkus
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Bettina Brunner
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
| | - Alice Sülzen
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
| | - Brigitte Nuscher
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Heike Hampel
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Xianyuan Xiang
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
- Graduate School of Systemic NeuroscienceLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Regina Feederle
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
- Munich Cluster for Systems Neurology (SyNergy)MunichGermany
- Helmholtz Center MunichGerman Research Center for Environmental HealthInstitute for Diabetes and ObesityCore Facility Monoclonal Antibody DevelopmentMunichGermany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
| | | | | | - Cathal Mahon
- Denali Therapeutics Inc.South San FranciscoCAUSA
| | | | - Ju Shi
- Denali Therapeutics Inc.South San FranciscoCAUSA
- Present address:
Jazz PharmaceuticalsPalo AltoCAUSA
| | - Do Jin Kim
- Denali Therapeutics Inc.South San FranciscoCAUSA
| | | | - Fen Huang
- Denali Therapeutics Inc.South San FranciscoCAUSA
| | | | - Mikael Simons
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
- Munich Cluster for Systems Neurology (SyNergy)MunichGermany
- Institute of Neuronal Cell Biology (TUM‐NZB)MunichGermany
| | | | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE) MunichMunichGermany
- Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MünchenMunichGermany
- Munich Cluster for Systems Neurology (SyNergy)MunichGermany
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160
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Berner DK, Wessolowski L, Armbrust F, Schneppenheim J, Schlepckow K, Koudelka T, Scharfenberg F, Lucius R, Tholey A, Kleinberger G, Haass C, Arnold P, Becker‐Pauly C. Meprin β cleaves TREM2 and controls its phagocytic activity on macrophages. FASEB J 2020; 34:6675-6687. [DOI: 10.1096/fj.201902183r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/03/2019] [Accepted: 03/12/2020] [Indexed: 11/11/2022]
Affiliation(s)
| | - Luisa Wessolowski
- Unit for Degradomics of the Protease Web, Biochemical Institute University of Kiel Kiel Germany
| | - Fred Armbrust
- Unit for Degradomics of the Protease Web, Biochemical Institute University of Kiel Kiel Germany
| | | | - Kai Schlepckow
- German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Tomas Koudelka
- Systematic Proteomics & Bioanalytics Institute for Experimental Medicine University of Kiel Kiel Germany
| | - Franka Scharfenberg
- Unit for Degradomics of the Protease Web, Biochemical Institute University of Kiel Kiel Germany
| | - Ralph Lucius
- Anatomical Institute University of Kiel Kiel Germany
| | - Andreas Tholey
- Systematic Proteomics & Bioanalytics Institute for Experimental Medicine University of Kiel Kiel Germany
| | - Gernot Kleinberger
- Biomedical Center, Biochemistry Ludwig‐Maximilians‐Universität Munich Munich Germany
- Munich Cluster for Systems Neurology Munich Germany
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Biomedical Center, Biochemistry Ludwig‐Maximilians‐Universität Munich Munich Germany
- Munich Cluster for Systems Neurology Munich Germany
| | | | - Christoph Becker‐Pauly
- Unit for Degradomics of the Protease Web, Biochemical Institute University of Kiel Kiel Germany
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161
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Hampel H, Caraci F, Cuello AC, Caruso G, Nisticò R, Corbo M, Baldacci F, Toschi N, Garaci F, Chiesa PA, Verdooner SR, Akman-Anderson L, Hernández F, Ávila J, Emanuele E, Valenzuela PL, Lucía A, Watling M, Imbimbo BP, Vergallo A, Lista S. A Path Toward Precision Medicine for Neuroinflammatory Mechanisms in Alzheimer's Disease. Front Immunol 2020; 11:456. [PMID: 32296418 PMCID: PMC7137904 DOI: 10.3389/fimmu.2020.00456] [Citation(s) in RCA: 182] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation commences decades before Alzheimer's disease (AD) clinical onset and represents one of the earliest pathomechanistic alterations throughout the AD continuum. Large-scale genome-wide association studies point out several genetic variants—TREM2, CD33, PILRA, CR1, MS4A, CLU, ABCA7, EPHA1, and HLA-DRB5-HLA-DRB1—potentially linked to neuroinflammation. Most of these genes are involved in proinflammatory intracellular signaling, cytokines/interleukins/cell turnover, synaptic activity, lipid metabolism, and vesicle trafficking. Proteomic studies indicate that a plethora of interconnected aberrant molecular pathways, set off and perpetuated by TNF-α, TGF-β, IL-1β, and the receptor protein TREM2, are involved in neuroinflammation. Microglia and astrocytes are key cellular drivers and regulators of neuroinflammation. Under physiological conditions, they are important for neurotransmission and synaptic homeostasis. In AD, there is a turning point throughout its pathophysiological evolution where glial cells sustain an overexpressed inflammatory response that synergizes with amyloid-β and tau accumulation, and drives synaptotoxicity and neurodegeneration in a self-reinforcing manner. Despite a strong therapeutic rationale, previous clinical trials investigating compounds with anti-inflammatory properties, including non-steroidal anti-inflammatory drugs (NSAIDs), did not achieve primary efficacy endpoints. It is conceivable that study design issues, including the lack of diagnostic accuracy and biomarkers for target population identification and proof of mechanism, may partially explain the negative outcomes. However, a recent meta-analysis indicates a potential biological effect of NSAIDs. In this regard, candidate fluid biomarkers of neuroinflammation are under analytical/clinical validation, i.e., TREM2, IL-1β, MCP-1, IL-6, TNF-α receptor complexes, TGF-β, and YKL-40. PET radio-ligands are investigated to accomplish in vivo and longitudinal regional exploration of neuroinflammation. Biomarkers tracking different molecular pathways (body fluid matrixes) along with brain neuroinflammatory endophenotypes (neuroimaging markers), can untangle temporal–spatial dynamics between neuroinflammation and other AD pathophysiological mechanisms. Robust biomarker–drug codevelopment pipelines are expected to enrich large-scale clinical trials testing new-generation compounds active, directly or indirectly, on neuroinflammatory targets and displaying putative disease-modifying effects: novel NSAIDs, AL002 (anti-TREM2 antibody), anti-Aβ protofibrils (BAN2401), and AL003 (anti-CD33 antibody). As a next step, taking advantage of breakthrough and multimodal techniques coupled with a systems biology approach is the path to pursue for developing individualized therapeutic strategies targeting neuroinflammation under the framework of precision medicine.
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Affiliation(s)
- Harald Hampel
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute-IRCCS, Troina, Italy
| | - A Claudio Cuello
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | - Robert Nisticò
- Laboratory of Neuropharmacology, EBRI Rita Levi-Montalcini Foundation, Rome, Italy.,School of Pharmacy, Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Massimo Corbo
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Filippo Baldacci
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nicola Toschi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Department of Radiology, "Athinoula A. Martinos" Center for Biomedical Imaging, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Francesco Garaci
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Casa di Cura "San Raffaele Cassino", Cassino, Italy
| | - Patrizia A Chiesa
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | | | | | - Félix Hernández
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jesús Ávila
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | | | | | - Alejandro Lucía
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain.,Research Institute of the Hospital 12 de Octubre ("imas"), Madrid, Spain.,Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | | | - Bruno P Imbimbo
- Research & Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Andrea Vergallo
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Simone Lista
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
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162
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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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163
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Kwon HS, Lee EH, Park HH, Jin JH, Choi H, Lee KY, Lee YJ, Lee JH, de Oliveira FMS, Kim HY, Seo Kim Y, Kim BJ, Heo SH, Chang DI, Kamali-Moghaddam M, Koh SH. Early increment of soluble triggering receptor expressed on myeloid cells 2 in plasma might be a predictor of poor outcome after ischemic stroke. J Clin Neurosci 2020; 73:215-218. [PMID: 32067825 DOI: 10.1016/j.jocn.2020.02.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/08/2020] [Indexed: 01/02/2023]
Abstract
Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) is derived from cleavage of TREM2, which is expressed on the cell surface of microlgia and other tissue-specific macrophages. In the present study, the changes in the sTREM2 levels after ischemic stroke (IS) and their association with clinical outcomes were evaluated. A total of 43 patients diagnosed with non-cardioembolic IS between June 2011 and May 2014 were consecutively included in this study. Patients treated with intravenous thrombolysis or intra-arterial thrombectomy were excluded. Plasma samples were collected three times (days 1, 7, and 90) after ictus. The sTREM2 level was measured in the samples using the highly sensitive solid-phase proximity ligation assay (SP-PLA). Among the 43 subjects, higher initial NIH stroke scale (NIHSS) score (P = 0.005), early increment of sTREM2 (P < 0.001), and late decrement of sTREM2 (P = 0.002), were more common in patients with poor outcome. Based on multivariate analysis, initial NIHSS score (P = 0.015) and early increment of sTREM2 (P = 0.032) were independently associated with poor outcome. The results from the present study indicate that increment of sTREM2 level at the early phase was a predictor of poor outcome. Serial follow-up of sTREM2 may aid prognosis after stroke.
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Affiliation(s)
- Hyuk Sung Kwon
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Eun-Hye Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea
| | - Hyun-Hee Park
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jeong-Hwa Jin
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Hojin Choi
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Kyu-Yong Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Young Joo Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jae-Hong Lee
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | | | - Hyun Young Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Young Seo Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Bum Joon Kim
- Department of Neurology, Kyung Hee University College of Medicine, Seoul, Republic of Korea
| | - Sung Hyuk Heo
- Department of Neurology, Kyung Hee University College of Medicine, Seoul, Republic of Korea
| | - Dae-Il Chang
- Department of Neurology, Kyung Hee University College of Medicine, Seoul, Republic of Korea
| | - Masood Kamali-Moghaddam
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
| | - Seong-Ho Koh
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea.
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164
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A novel homozygous mutation in TREM2 found in a Chinese early-onset dementia family with mild bone involvement. Neurobiol Aging 2020; 86:201.e1-201.e7. [DOI: 10.1016/j.neurobiolaging.2019.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/12/2018] [Accepted: 01/12/2019] [Indexed: 12/15/2022]
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165
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Williams T, Borchelt DR, Chakrabarty P. Therapeutic approaches targeting Apolipoprotein E function in Alzheimer's disease. Mol Neurodegener 2020; 15:8. [PMID: 32005122 PMCID: PMC6995170 DOI: 10.1186/s13024-020-0358-9] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
One of the primary genetic risk factors for Alzheimer’s disease (AD) is the presence of the Ɛ4 allele of apolipoprotein E (APOE). APOE is a polymorphic lipoprotein that is a major cholesterol carrier in the brain. It is also involved in various cellular functions such as neuronal signaling, neuroinflammation and glucose metabolism. Humans predominantly possess three different allelic variants of APOE, termed E2, E3, and E4, with the E3 allele being the most common. The presence of the E4 allele is associated with increased risk of AD whereas E2 reduces the risk. To understand the molecular mechanisms that underlie APOE-related genetic risk, considerable effort has been devoted towards developing cellular and animal models. Data from these models indicate that APOE4 exacerbates amyloid β plaque burden in a dose-dependent manner. and may also enhance tau pathogenesis in an isoform-dependent manner. Other studies have suggested APOE4 increases the risk of AD by mechanisms that are distinct from modulation of Aβ or tau pathology. Further, whether plasma APOE, by influencing systemic metabolic pathways, can also possibly alter CNS function indirectly is not complete;y understood. Collectively, the available studies suggest that APOE may impact multiple signaling pathways and thus investigators have sought therapeutics that would disrupt pathological functions of APOE while preserving or enhancing beneficial functions. This review will highlight some of the therapeutic strategies that are currently being pursued to target APOE4 towards preventing or treating AD and we will discuss additional strategies that holds promise for the future.
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Affiliation(s)
- Tosha Williams
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA
| | - David R Borchelt
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA.,McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA
| | - Paramita Chakrabarty
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, 32610, USA. .,Department of Neuroscience, University of Florida, Gainesville, FL, 32610, USA. .,McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
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166
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Garcia-Reitboeck P, Phillips A, Piers TM, Villegas-Llerena C, Butler M, Mallach A, Rodrigues C, Arber CE, Heslegrave A, Zetterberg H, Neumann H, Neame S, Houlden H, Hardy J, Pocock JM. Human Induced Pluripotent Stem Cell-Derived Microglia-Like Cells Harboring TREM2 Missense Mutations Show Specific Deficits in Phagocytosis. Cell Rep 2020; 24:2300-2311. [PMID: 30157425 PMCID: PMC6130048 DOI: 10.1016/j.celrep.2018.07.094] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/31/2018] [Accepted: 07/27/2018] [Indexed: 12/22/2022] Open
Abstract
Dysfunction of microglia, the brain’s immune cells, is linked to neurodegeneration. Homozygous missense mutations in TREM2 cause Nasu-Hakola disease (NHD), an early-onset dementia. To study the consequences of these TREM2 variants, we generated induced pluripotent stem cell-derived microglia-like cells (iPSC-MGLCs) from patients with NHD caused by homozygous T66M or W50C missense mutations. iPSC-MGLCs expressed microglial markers and secreted higher levels of TREM2 than primary macrophages. TREM2 expression and secretion were reduced in variant lines. LPS-mediated cytokine secretion was comparable between control and TREM2 variant iPSC-MGLCs, whereas survival was markedly reduced in cells harboring missense mutations when compared with controls. Furthermore, TREM2 missense mutations caused a marked impairment in the phagocytosis of apoptotic bodies, but not in Escherichia coli or zymosan substrates. Coupled with changes in apoptotic cell-induced cytokine release and migration, these data identify specific deficits in the ability of iPSC-MGLCs harboring TREM2 missense mutations to respond to specific pathogenic signals. Generated human microglia-like cells from TREM2 T66M and W50C mutation carriers Heterozygous and homozygous TREM2 variants impair shedding of soluble TREM2 Cytokine secretion not altered in TREM2 variants following LPS exposure Substrate specific impairment of microglial function observed in TREM2 variants
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Affiliation(s)
- Pablo Garcia-Reitboeck
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK; Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Alexandra Phillips
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Thomas M Piers
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK; Eisai:UCL Therapeutic Innovation Group, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Claudio Villegas-Llerena
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Matt Butler
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK; Eisai:UCL Therapeutic Innovation Group, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Anna Mallach
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Celia Rodrigues
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Charles E Arber
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Amanda Heslegrave
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Henrik Zetterberg
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK; Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg 41345, Sweden
| | - Harald Neumann
- Neural Regeneration Group, Institute of Reconstructive Neurobiology, University of Bonn, Bonn 53127, Germany
| | - Stephen Neame
- Neurology Business Group, Hatfield Research Laboratories, Neurology Innovation Centre, Eisai Limited, Hatfield, AL10 9SN, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - John Hardy
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 1PJ, UK
| | - Jennifer M Pocock
- Department of Neuroinflammation, University College London Institute of Neurology, London WC1N 1PJ, UK.
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167
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Wang Q, Xu Y, Qi C, Liu A, Zhao Y. Association study of serum soluble TREM2 with vascular dementia in Chinese Han population. Int J Neurosci 2020; 130:708-712. [PMID: 31847649 DOI: 10.1080/00207454.2019.1702548] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Objective: Recent extensive evidence suggests that the triggering receptor expressed on myeloid cells 2 (TREM2) is closely implicated in the pathogenesis of Alzheimer's disease (AD). However, no relative data exist regarding vascular dementia (VD). This study aimed to investigate the association between serum soluble TREM2 (sTREM2) and vascular dementia in Chinese Han population.Methods: A total of 120 VD patients and 120 cognitively normal controls matched for age and gender were enrolled for this study. Demographic and clinical characteristics were recorded at admission. Cognitive functions were assessed by the Mini-Mental State Examination (MMSE) and serum sTREM2 levels were detected using sandwich ELISA method.Results: Demographic and clinical characteristics did not differ dramatically between groups. Serum sTREM2 levels in VD patients are significantly decreased compared with normal controls. In VD patients, the serum sTREM2 levels were positively correlated with MMSE scores (r = 0.387, p = 0.008), and the association was independent of demographic and clinical characteristics (β = 0.396, p < 0.001).Conclusion: VD patients have significantly lower serum sTREM2 levels in comparison to normal controls. Serum sTREM2 levels may be used as a potential predictive biomarker of cognitive decline in VD.
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Affiliation(s)
- Qian Wang
- Department of Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong Province, China.,Department of Central Laboratory, Taian City Central Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong Province, China
| | - Yuzhen Xu
- Department of Neurology, Taian City Central Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong Province, China
| | - Chunhua Qi
- Department of Central Laboratory, Taian City Central Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong Province, China
| | - Aihua Liu
- Department of Central Laboratory, Taian City Central Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong Province, China
| | - Yueran Zhao
- Department of Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
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168
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Merlo S, Spampinato SF, Caruso GI, Sortino MA. The Ambiguous Role of Microglia in Aβ Toxicity: Chances for Therapeutic Intervention. Curr Neuropharmacol 2020; 18:446-455. [PMID: 32003695 PMCID: PMC7457435 DOI: 10.2174/1570159x18666200131105418] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/09/2020] [Accepted: 01/29/2020] [Indexed: 02/08/2023] Open
Abstract
Amyloid-β (Aβ) has long been shown to be critical in Alzheimer's disease pathophysiology. Microglia contributes to the earliest responses to Aβ buildup, by direct interaction through multiple receptors. Microglial cells operate Aβ clearance and trigger inflammatory/regenerative processes that take place in the long years of silent disease progression that precede symptomatic appearance. But in time and with aging, the fine balance between pro- and anti-inflammatory activity of microglia deranges, negatively impacting its Aβ-clearing ability. Furthermore, in recent years, microglial activation has proven to be much more complex than the mere dichotomic pro/antiinflammatory polarization previously accepted. Microglia can display a wide spectrum of phenotypes, which can even be mixed. On these bases, it is evident that while pharmacological intervention aiding microglia to prolong its ability to cope with Aβ buildup could be extremely relevant, its feasibility is hampered by such high complexity, which still needs to be completely understood.
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Affiliation(s)
- Sara Merlo
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology; University of Catania, Catania, Italy
| | - Simona Federica Spampinato
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology; University of Catania, Catania, Italy
| | - Grazia Ilaria Caruso
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology; University of Catania, Catania, Italy
| | - Maria Angela Sortino
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology; University of Catania, Catania, Italy
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169
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Milà-Alomà M, Suárez-Calvet M, Molinuevo JL. Latest advances in cerebrospinal fluid and blood biomarkers of Alzheimer's disease. Ther Adv Neurol Disord 2019; 12:1756286419888819. [PMID: 31897088 PMCID: PMC6920596 DOI: 10.1177/1756286419888819] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 10/21/2019] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease and its diagnosis has classically been based on clinical symptoms. Recently, a biological rather than a syndromic definition of the disease has been proposed that is based on biomarkers that reflect neuropathological changes. In AD, there are two main biomarker categories, namely neuroimaging and fluid biomarkers [cerebrospinal fluid (CSF) and blood]. As a complex and multifactorial disease, AD biomarkers are important for an accurate diagnosis and to stage the disease, assess the prognosis, test target engagement, and measure the response to treatment. In addition, biomarkers provide us with information that, even if it does not have a current clinical use, helps us to understand the mechanisms of the disease. In addition to the pathological hallmarks of AD, which include amyloid-β and tau deposition, there are multiple concomitant pathological events that play a key role in the disease. These include, but are not limited to, neurodegeneration, inflammation, vascular dysregulation or synaptic dysfunction. In addition, AD patients often have an accumulation of other proteins including α-synuclein and TDP-43, which may have a pathogenic effect on AD. In combination, there is a need to have biomarkers that reflect different aspects of AD pathogenesis and this will be important in the future to establish what are the most suitable applications for each of these AD-related biomarkers. It is unclear whether sex, gender, or both have an effect on the causes of AD. There may be differences in fluid biomarkers due to sex but this issue has often been neglected and warrants further research. In this review, we summarize the current state of the principal AD fluid biomarkers and discuss the effect of sex on these biomarkers.
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Affiliation(s)
- Marta Milà-Alomà
- Barcelonaβeta Brain Research Center (BBRC),
Pasqual Maragall Foundation, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research
Institute), Barcelona
| | - Marc Suárez-Calvet
- Barcelonaβeta Brain Research Center (BBRC),
Pasqual Maragall Foundation, Barcelona, Spain
- IMIM (Hospital del Mar Medical Research
Institute), Barcelona
- Department of Neurology, Hospital del Mar,
Barcelona
| | - José Luís Molinuevo
- Scientific Director, Alzheimer’s Prevention
Program, Barcelonaβeta Brain Research Center, Wellington 30, Barcelona,
08005, Spain
- IMIM (Hospital del Mar Medical Research
Institute), Barcelona
- CIBER Fragilidad y Envejecimiento Saludable,
Madrid, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
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170
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Peng G, Qiu J, Liu H, Zhou M, Huang S, Guo W, Lin Y, Chen X, Li Z, Li G, Zhang W, Zhang Y, Li X, Wu Z, Wei L, Yang X, Zhu X, Mo M, Xu P. Analysis of Cerebrospinal Fluid Soluble TREM2 and Polymorphisms in Sporadic Parkinson's Disease in a Chinese Population. J Mol Neurosci 2019; 70:294-301. [PMID: 31833018 DOI: 10.1007/s12031-019-01424-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 10/18/2019] [Indexed: 01/20/2023]
Abstract
BACKGROUND Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial surface receptor that mediates the degradation disorder of amyloid β (Aβ) in Alzheimer's disease. However, the role of TREM2 in Parkinson's disease (PD) and α-Synclein (α-Syn) degradation is largely unknown. METHODS In this case-control study on Chinese population, we sequenced for polymorphisms in exon 2 of the TREM2 gene in 1,292 individuals, PD cases (n = 612), healthy controls (n = 680) by Sanger sequence, and compared the distribution of allelic frequencies between the two groups by the Fisher's exact test. Additionally, we developed and used the enzyme-linked immunosorbent assay to evaluated soluble TREM2 (sTREM2) levels in the cerebrospinal fluid (CSF), and plasma in partial of sequenced groups (55 PD and 40 healthy controls) analyzed their relationship with total a-syn (t-a-Syn). RESULTS Two novel variants were detected in exon 2 of the TREM2 gene, namely, p.S81 N, p.G58D; however, these were not significantly associated with PD (612 PD and 680 healthy controls). sTREM2 in CSF was significantly upregulated in PD patients compared to healthy controls (433.1 ± 24.7 pg/mL vs. 275.2 ± 17.9 pg/mL, p < 0.0001), but not in plasma (281.7 ± 29.3 pg/mL vs. 257.8 ± 16.5 pg/mL, p = 0.805). In PD patients, sTREM2 was positively correlated with t-α-syn (r = 0.62, p = 0.0001) in CSF, but not in plasma (r = 0.02, p = 0.89). CONCLUSIONS Although it may not indicate that exon 2 polymorphisms of TREM2 play a role in the pathogenesis of PD in the Chinese population, our findings described above highlight the relevance of CSF sTREM2 as a promising biomarker and are extremely possible to the therapeutic target for PD in the future.
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Affiliation(s)
- Guoyou Peng
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Jiewen Qiu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Hanqun Liu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Miaomiao Zhou
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Shuxuan Huang
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Wenyuan Guo
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Yuwan Lin
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Xiang Chen
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Zhe Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Guihua Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Wenlong Zhang
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Yunlong Zhang
- Department of Physiology, Guangzhou Medical University, Guangzhou, 511436, China.,Neuroscience Center, Guangzhou Medical University, Guangzhou, 511436, China
| | - Xingjian Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Zhuohua Wu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China
| | - Lei Wei
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, China
| | - Xinling Yang
- Department of Neurology, The Second Affiliated Hospital of Xinjiang Medical University, Urumqi, 830011, China
| | - Xiaoqin Zhu
- Department of Physiology, Guangzhou Medical University, Guangzhou, 511436, China. .,Neuroscience Center, Guangzhou Medical University, Guangzhou, 511436, China.
| | - Mingshu Mo
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China.
| | - Pingyi Xu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 511436, China. .,Neuroscience Center, Guangzhou Medical University, Guangzhou, 511436, China.
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171
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Santiago JA, Bottero V, Potashkin JA. Transcriptomic and Network Analysis Highlight the Association of Diabetes at Different Stages of Alzheimer's Disease. Front Neurosci 2019; 13:1273. [PMID: 31849586 PMCID: PMC6895844 DOI: 10.3389/fnins.2019.01273] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) and type 2 diabetes (T2D) are among the most prevalent chronic diseases affecting the aging population. Extensive research evidence indicates that T2D is a well-established risk factor for AD; however, the molecular mechanisms underlying this association have not been fully elucidated. Furthermore, how T2D may contribute to the progression of AD is a subject of extensive investigation. In this study, we compared the blood transcriptome of patients with mild cognitive impairment (MCI), AD, and advanced AD to those afflicted with T2D to unveil shared and unique pathways and potential therapeutic targets. Blood transcriptomic analyses revealed a positive correlation between gene expression profiles of MCI, AD, and T2D in seven independent microarrays. Interestingly, gene expression profiles from women with advanced AD correlated negatively with T2D, suggesting sex-specific differences in T2D as a risk factor for AD. Network and pathway analysis revealed that shared molecular networks between MCI and T2D were predominantly enriched in inflammation and infectious diseases whereas those networks shared between overt AD and T2D were involved in the phosphatidylinositol 3-kinase and protein kinase B/Akt (PI3K-AKT) signaling pathway, a major mediator of insulin signaling in the body. The PI3K-AKT signaling pathway became more significantly dysregulated in the advanced AD and T2D shared network. Furthermore, endocrine resistance and atherosclerosis pathways emerged as dysregulated pathways in the advanced AD and T2D shared network. Interestingly, network analysis of shared differentially expressed genes between children with T2D and MCI subjects identified forkhead box O3 (FOXO3) as a central transcriptional regulator, suggesting that it may be a potential therapeutic target for early intervention in AD. Collectively, these results suggest that T2D may be implicated at different stages of AD through different molecular pathways disrupted during the preclinical phase of AD and more advanced stages of the disease.
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Affiliation(s)
| | - Virginie Bottero
- Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
| | - Judith A Potashkin
- Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
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172
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Zhong L, Chen XF. The Emerging Roles and Therapeutic Potential of Soluble TREM2 in Alzheimer's Disease. Front Aging Neurosci 2019; 11:328. [PMID: 32038221 PMCID: PMC6988790 DOI: 10.3389/fnagi.2019.00328] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 11/12/2019] [Indexed: 01/14/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia characterized by the deposition of extracellular amyloid-β (Aβ)-containing plaques, the formation of intraneuronal neurofibrillary tangles as well as neuroinflammatory changes. As the key player in the brain innate immune system, microglia has now taken a center stage in AD research. A large number of AD risk loci identified by genome-wide association studies are located in or near the genes highly expressed in microglia. Among them, the triggering receptor expressed on myeloid cells 2 (TREM2) has drawn much attention. A rare variant in TREM2 increases AD risk with an odds ratio comparable to the strongest genetic risk factor apolipoprotein ε4 allele. In the past 6 years, extensive studies have dissected the mechanisms by which TREM2 and its variants modulate microglial functions impacting amyloid and tau pathologies in both animal models and human studies. In addition to the full-length TREM2, research on the soluble form of TREM2 (sTREM2) has facilitated the translation of preclinical findings on TREM2. In this review, we summarize our current understanding of the biology and pathobiology of sTREM2 including its origin, its emergence as a disease biomarker, and its potential neuroprotective functions. These aspects are important for understanding the involvement of sTREM2 in AD pathogenesis and may provide novel insights into applying sTREM2 for AD diagnosis and therapy.
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Affiliation(s)
- Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China.,Shenzhen Research Institute of Xiamen University, Shenzhen, China
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173
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Liu C, Yu J. Genome-Wide Association Studies for Cerebrospinal Fluid Soluble TREM2 in Alzheimer's Disease. Front Aging Neurosci 2019; 11:297. [PMID: 31708768 PMCID: PMC6823606 DOI: 10.3389/fnagi.2019.00297] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 10/14/2019] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia. Rare variants in triggering receptor expressed on myeloid cells 2 (TREM2) have been identified as risk factors for AD. Soluble TREM2 (sTREM2) in the cerebrospinal fluid (CSF) is a potential and novel biomarker of neuroinflammation implicated in the onset and progression of AD. To explore the roles of CSF sTREM2 on the pathogenesis of AD, we performed genome-wide association studies (GWAS) by using the data from Alzheimer’s Disease Neuroimaging Initiative (ADNI). We found CSF sTREM2 levels were elevated with the disease stages, but there was no significant difference between that of AD patients and normal participants. CSF sTREM2 was positively correlated with CSF total tau and phosphorylated-tau levels (ρ > 0.35, p < 1e-06; ρ > 0.32, p < 1e-05, respectively) for all disease states. We identified the most significant CSF sTREM2 related locus was rs7232 (FDR = 3.01e-08), a missense variant in MS4A6A gene of chromosome 11. Moreover, we also detected rs7232 was highly associated with MS4A6A gene expression (FDR = 1.37e-18). In addition, our pathway analysis for our significant GWAS results showed that biological processes for regulation of viruses and immune response were highly overrepresented or enriched. Our study suggests that CSF sTREM2 plays an informative role in AD progression. Moreover, CSF sTREM2 and AD is highly related to viral infections and immune response.
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Affiliation(s)
- Changan Liu
- Department of Mathematics, University of Houston, Houston, TX, United States
| | - Jun Yu
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
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174
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García-Revilla J, Alonso-Bellido IM, Burguillos MA, Herrera AJ, Espinosa-Oliva AM, Ruiz R, Cruz-Hernández L, García-Domínguez I, Roca-Ceballos MA, Santiago M, Rodríguez-Gómez JA, Soto MS, de Pablos RM, Venero JL. Reformulating Pro-Oxidant Microglia in Neurodegeneration. J Clin Med 2019; 8:E1719. [PMID: 31627485 PMCID: PMC6832973 DOI: 10.3390/jcm8101719] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/11/2019] [Accepted: 10/12/2019] [Indexed: 12/13/2022] Open
Abstract
In neurodegenerative diseases, microglia-mediated neuroinflammation and oxidative stress are central events. Recent genome-wide transcriptomic analyses of microglial cells under different disease conditions have uncovered a new subpopulation named disease-associated microglia (DAM). These studies have challenged the classical view of the microglia polarization state's proinflammatory M1 (classical activation) and immunosuppressive M2 (alternative activation). Molecular signatures of DAM and proinflammatory microglia (highly pro-oxidant) have shown clear differences, yet a partial overlapping gene profile is evident between both phenotypes. The switch activation of homeostatic microglia into reactive microglia relies on the selective activation of key surface receptors involved in the maintenance of brain homeostasis (a.k.a. pattern recognition receptors, PRRs). Two relevant PRRs are toll-like receptors (TLRs) and triggering receptors expressed on myeloid cells-2 (TREM2), whose selective activation is believed to generate either a proinflammatory or a DAM phenotype, respectively. However, the recent identification of endogenous disease-related ligands, which bind to and activate both TLRs and TREM2, anticipates the existence of rather complex microglia responses. Examples of potential endogenous dual ligands include amyloid β, galectin-3, and apolipoprotein E. These pleiotropic ligands induce a microglia polarization that is more complicated than initially expected, suggesting the possibility that different microglia subtypes may coexist. This review highlights the main microglia polarization states under disease conditions and their leading role orchestrating oxidative stress.
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Affiliation(s)
- Juan García-Revilla
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Isabel M Alonso-Bellido
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Miguel A Burguillos
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Antonio J Herrera
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Ana M Espinosa-Oliva
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Rocío Ruiz
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Luis Cruz-Hernández
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Irene García-Domínguez
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - María A Roca-Ceballos
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Marti Santiago
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - José A Rodríguez-Gómez
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Departament of Medical Physiology and Biophysics, Faculty of Medicine, University of Seville, 41009 Sevilla, Spain.
| | - Manuel Sarmiento Soto
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - Rocío M de Pablos
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
| | - José L Venero
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.
- Institute of Biomedicine of Seville (IBIS)-Hospital Universitario Virgen del Rocío/CSIC/University of Seville, 41012 Seville, Spain.
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175
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Yao H, Coppola K, Schweig JE, Crawford F, Mullan M, Paris D. Distinct Signaling Pathways Regulate TREM2 Phagocytic and NFκB Antagonistic Activities. Front Cell Neurosci 2019; 13:457. [PMID: 31649511 PMCID: PMC6795686 DOI: 10.3389/fncel.2019.00457] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/25/2019] [Indexed: 11/13/2022] Open
Abstract
Several genetic variants of the Triggering Receptor Expressed on Myeloid Cells-2 (TREM2) have been shown to increase the risk of developing Alzheimer’s disease (AD) supporting a role of microglia and immune cells in the pathobiology of AD. We have employed an ectopic model of TREM2 and DAP12 expression in HEK293 cells to study selectively TREM2 dependent signaling and phagocytic functions and evaluated the effects of some of the TREM2 mutations associated with AD. We show that shedding of the TREM2 N-terminal domain does not affect the inhibition of NFκB activation induced by TREM2 while it completely blocks phagocytosis suggesting that TREM2 anti-inflammatory properties can be mediated by the TREM2 C-terminal fragment while the phagocytic activity requires the full-length receptor. In addition, we confirm in that model that apolipoprotein E (APOE) is a ligand for TREM2 and triggers TREM2 signaling. In particular, we show that APOE4 stimulates spleen tyrosine kinase (SYK) activation more potently than APOE2 in a TREM2 dependent manner. Interestingly, TREM2 appears to antagonize NFκB activation induced by phorbol ester but is unable to prevent TNFα induction of NFκB activation suggesting that TREM2 antagonizes inflammatory events triggered downstream of PKC. TREM2 mutations drastically impact TREM2 phagocytosis as well as its ability to antagonize NFκB activation and notably prevent the activation of the PI3K/AKT pathway observed with wild-type TREM2. Overall our data suggest that TREM2 dependent phagocytosis requires an activation of the SYK/PI3K/AKT/PLCγ pathways while the suppression of NFκB activation by TREM2 is independent of SYK, PI3K, and PLCγ activities. This model of ectopic TREM2-DAP12 co-expression appears suitable to study TREM2 signaling as several biological functions of TREM2 and TREM2 mutations that have been previously described in myeloid and microglial cells were also replicated in this model.
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Affiliation(s)
- Hailan Yao
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Kyle Coppola
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Jonas Elias Schweig
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Fiona Crawford
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Michael Mullan
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Daniel Paris
- The Roskamp Institute, Sarasota, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
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176
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Karanfilian L, Tosto MG, Malki K. The role of TREM2 in Alzheimer's disease; evidence from transgenic mouse models. Neurobiol Aging 2019; 86:39-53. [PMID: 31727362 DOI: 10.1016/j.neurobiolaging.2019.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a currently incurable neurodegenerative disorder. Several genetic studies have identified a rare variant of triggering receptor expressed on myeloid cells 2 (TREM2) as a risk factor for AD. TREM2 is thought to trigger the microglial response to amyloid plaques. Mouse models have helped elucidate mechanisms through which TREM2 affects microglial function and modulates pathological features of AD. A synthesis of the 35 mouse-model studies included in this review indicates that TREM2 modulates amyloid plaque composition and deposition, microglial morphology and proliferation, neuroinflammation, and tau phosphorylation. TREM2 also acts as a sensor for anionic lipids exposed during neuronal apoptosis and Aβ deposition, may improve spatial abilities and memory, and protect against apoptosis. In early stages of AD, TREM2 knock-down reduces expression of proinflammatory cytokines and upregulates anti-inflammatory cytokines but in later stages, TREM2 may contribute to the disease by aggravating neuroinflammation. The results provide insight into TREM2-related mechanisms that may be associated with AD in humans and may aid future development of disease-modifying pharmacological treatments targeting TREM2.
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Affiliation(s)
- Lucine Karanfilian
- King's College London at the Institute of Psychiatry, Psychology and Neuroscience (IOPPN), London, UK
| | - Maria Grazia Tosto
- King's College London at the Institute of Psychiatry, Psychology and Neuroscience (IOPPN), London, UK
| | - Karim Malki
- King's College London at the Institute of Psychiatry, Psychology and Neuroscience (IOPPN), London, UK; UCB Pharma, Statistical Sciences and Innovation, Slough, UK.
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177
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Nizami S, Hall‐Roberts H, Warrier S, Cowley SA, Di Daniel E. Microglial inflammation and phagocytosis in Alzheimer's disease: Potential therapeutic targets. Br J Pharmacol 2019; 176:3515-3532. [PMID: 30740661 PMCID: PMC6715590 DOI: 10.1111/bph.14618] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/19/2018] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
One of the largest unmet medical needs is a disease-modifying treatment for Alzheimer's disease (AD). Recently, the role of microglia in disease, particularly AD, has gained great interest, following the identification of several disease risk-associated genes that are highly expressed in microglia. Microglia play a critical homeostatic role in the brain, with neuroinflammatory and phagocytic mechanisms being of particular importance. Here, we review the role of NLRP3, the complement system, and the triggering receptor expressed in myeloid cells 2 (TREM2) in modulating microglial functions. We have reviewed the targets, their molecular pathways and the therapeutic interventions aimed at modulating these targets, in the hope of discovering a novel therapeutic approach for the treatment of AD. LINKED ARTICLES: This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc.
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Affiliation(s)
- Sohaib Nizami
- Alzheimer's Research UK Oxford Drug Discovery Institute, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Hazel Hall‐Roberts
- Alzheimer's Research UK Oxford Drug Discovery Institute, Nuffield Department of MedicineUniversity of OxfordOxfordUK
- James Martin Stem Cell Facility, Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Sharat Warrier
- Alzheimer's Research UK Oxford Drug Discovery Institute, Nuffield Department of MedicineUniversity of OxfordOxfordUK
- James Martin Stem Cell Facility, Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Sally A. Cowley
- James Martin Stem Cell Facility, Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Elena Di Daniel
- Alzheimer's Research UK Oxford Drug Discovery Institute, Nuffield Department of MedicineUniversity of OxfordOxfordUK
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178
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Deming Y, Filipello F, Cignarella F, Cantoni C, Hsu S, Mikesell R, Li Z, Del-Aguila JL, Dube U, Farias FG, Bradley J, Budde J, Ibanez L, Fernandez MV, Blennow K, Zetterberg H, Heslegrave A, Johansson PM, Svensson J, Nellgård B, Lleo A, Alcolea D, Clarimon J, Rami L, Molinuevo JL, Suárez-Calvet M, Morenas-Rodríguez E, Kleinberger G, Ewers M, Harari O, Haass C, Brett TJ, Benitez BA, Karch CM, Piccio L, Cruchaga C. The MS4A gene cluster is a key modulator of soluble TREM2 and Alzheimer's disease risk. Sci Transl Med 2019; 11:eaau2291. [PMID: 31413141 PMCID: PMC6697053 DOI: 10.1126/scitranslmed.aau2291] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 04/05/2019] [Indexed: 12/13/2022]
Abstract
Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in cerebrospinal fluid (CSF) has been associated with Alzheimer's disease (AD). TREM2 plays a critical role in microglial activation, survival, and phagocytosis; however, the pathophysiological role of sTREM2 in AD is not well understood. Understanding the role of sTREM2 in AD may reveal new pathological mechanisms and lead to the identification of therapeutic targets. We performed a genome-wide association study (GWAS) to identify genetic modifiers of CSF sTREM2 obtained from the Alzheimer's Disease Neuroimaging Initiative. Common variants in the membrane-spanning 4-domains subfamily A (MS4A) gene region were associated with CSF sTREM2 concentrations (rs1582763; P = 1.15 × 10-15); this was replicated in independent datasets. The variants associated with increased CSF sTREM2 concentrations were associated with reduced AD risk and delayed age at onset of disease. The single-nucleotide polymorphism rs1582763 modified expression of the MS4A4A and MS4A6A genes in multiple tissues, suggesting that one or both of these genes are important for modulating sTREM2 production. Using human macrophages as a proxy for microglia, we found that MS4A4A and TREM2 colocalized on lipid rafts at the plasma membrane, that sTREM2 increased with MS4A4A overexpression, and that silencing of MS4A4A reduced sTREM2 production. These genetic, molecular, and cellular findings suggest that MS4A4A modulates sTREM2. These findings also provide a mechanistic explanation for the original GWAS signal in the MS4A locus for AD risk and indicate that TREM2 may be involved in AD pathogenesis not only in TREM2 risk-variant carriers but also in those with sporadic disease.
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Affiliation(s)
- Yuetiva Deming
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Fabia Filipello
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Francesca Cignarella
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Claudia Cantoni
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Simon Hsu
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Robert Mikesell
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zeran Li
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jorge L Del-Aguila
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Umber Dube
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Fabiana Geraldo Farias
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joseph Bradley
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John Budde
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Laura Ibanez
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - Amanda Heslegrave
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
| | - Per M Johansson
- Department of Clinical Sciences Helsingborg, Lund University, Lund, Sweden
| | - Johan Svensson
- Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden
| | - Bengt Nellgård
- Department of Anesthesiology, Sahlgrenska University Hospital, Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden
| | - Alberto Lleo
- Department of Neurology, IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
- Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Daniel Alcolea
- Department of Neurology, IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
- Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jordi Clarimon
- Department of Neurology, IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
- Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Lorena Rami
- IDIBAPS, Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic, Barcelona, Spain
| | - José Luis Molinuevo
- IDIBAPS, Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic, Barcelona, Spain
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
| | - Marc Suárez-Calvet
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Estrella Morenas-Rodríguez
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Gernot Kleinberger
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- ISAR Bioscience GmbH, 2152 Planegg, Germany
| | - Michael Ewers
- Institute for Stroke and Dementia Research, University Hospital, LMU, Munich, Germany
| | - Oscar Harari
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Thomas J Brett
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bruno A Benitez
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Celeste M Karch
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Laura Piccio
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
- NeuroGenomics and Informatics, Washington University School of Medicine, St. Louis, MO 63110, USA
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179
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Zhao Y, Wu X, Li X, Jiang LL, Gui X, Liu Y, Sun Y, Zhu B, Piña-Crespo JC, Zhang M, Zhang N, Chen X, Bu G, An Z, Huang TY, Xu H. TREM2 Is a Receptor for β-Amyloid that Mediates Microglial Function. Neuron 2019. [PMID: 29518356 DOI: 10.1016/j.neuron.2018.01.031] [Citation(s) in RCA: 420] [Impact Index Per Article: 84.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mutations in triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to increased Alzheimer's disease (AD) risk. Neurobiological functions of TREM2 and its pathophysiological ligands remain elusive. Here we found that TREM2 directly binds to β-amyloid (Aβ) oligomers with nanomolar affinity, whereas AD-associated TREM2 mutations reduce Aβ binding. TREM2 deficiency impairs Aβ degradation in primary microglial culture and mouse brain. Aβ-induced microglial depolarization, K+ inward current induction, cytokine expression and secretion, migration, proliferation, apoptosis, and morphological changes are dependent on TREM2. In addition, TREM2 interaction with its signaling adaptor DAP12 is enhanced by Aβ, regulating downstream phosphorylation of SYK and GSK3β. Our data demonstrate TREM2 as a microglial Aβ receptor transducing physiological and AD-related pathological effects associated with Aβ.
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Affiliation(s)
- Yingjun Zhao
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Xilin Wu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Department of Neurology, Union Hospital, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Xiaoguang Li
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Lu-Lin Jiang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Xun Gui
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yan Liu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Yu Sun
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Bing Zhu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Juan C Piña-Crespo
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Muxian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Ningyan Zhang
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Xiaochun Chen
- Department of Neurology, Union Hospital, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350001, China
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China; Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Zhiqiang An
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Timothy Y Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Huaxi Xu
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361102, China.
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180
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Mee-Inta O, Zhao ZW, Kuo YM. Physical Exercise Inhibits Inflammation and Microglial Activation. Cells 2019; 8:cells8070691. [PMID: 31324021 PMCID: PMC6678635 DOI: 10.3390/cells8070691] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/20/2022] Open
Abstract
Accumulating evidence indicates that exercise can enhance brain function and attenuate neurodegeneration. Besides improving neuroplasticity by altering the synaptic structure and function in various brain regions, exercise also modulates multiple systems that are known to regulate neuroinflammation and glial activation. Activated microglia and several pro-inflammatory cytokines play active roles in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease. The purpose of this review is to highlight the impacts of exercise on microglial activation. Possible mechanisms involved in exercise-modulated microglial activation are also discussed. Undoubtedly, more studies are needed in order to disclose the detailed mechanisms, but this approach offers therapeutic potential for improving the brain health of millions of aging people where pharmacological intervention has failed.
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Affiliation(s)
- Onanong Mee-Inta
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan
| | - Zi-Wei Zhao
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan
| | - Yu-Min Kuo
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
- Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan 70101, Taiwan.
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181
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Hou XH, Bi YL, Tan MS, Xu W, Li JQ, Shen XN, Dou KX, Tan CC, Tan L, Yu JT. Genome-wide association study identifies Alzheimer's risk variant in MS4A6A influencing cerebrospinal fluid sTREM2 levels. Neurobiol Aging 2019; 84:241.e13-241.e20. [PMID: 31204042 DOI: 10.1016/j.neurobiolaging.2019.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/25/2019] [Accepted: 05/13/2019] [Indexed: 12/31/2022]
Abstract
The triggering receptor expressed on myeloid cells 2 (TREM2) gene has been reported to increase the risk of Alzheimer's disease (AD). The soluble TREM2 protein (sTREM2) in cerebrospinal fluid (CSF) was also associated with AD. However, the role of sTREM2 in AD and its genetic modifiers remain unclear. We carried out a genome-wide association study for CSF sTREM2 levels using participants from the Alzheimer's Disease Neuroimaging Initiative and validated the significant association in an independent cohort from Chinese Alzheimer's Biomarker and LifestylE study. rs7232 in membrane spanning 4-domains A6A (MS4A6A) gene was associated with CSF sTREM2 levels at genome-wide significance (p = 1.42 × 10-15). The locus influences CSF sTREM2 levels especially in nondemented individuals. And the association was replicable in the validation cohort from Chinese Alzheimer's Biomarker and LifestylE study (p = 0.0106). Besides, the expressions of MS4A6A and TREM2 were correlated in brain regions (p < 2 × 10-16). The findings of our study suggest that the AD risk variant in the MS4A6A gene participates in the regulation of sTREM2.
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Affiliation(s)
- Xiao-He Hou
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Yan-Lin Bi
- Department of Anesthesiology, Qingdao Municipal Hospital, Qingdao University, China
| | - Meng-Shan Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Wei Xu
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Jie-Qiong Li
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Xue-Ning Shen
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Kai-Xin Dou
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Chen-Chen Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, China
| | | | - Jin-Tai Yu
- Department of Neurology and Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
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182
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Dhiman K, Blennow K, Zetterberg H, Martins RN, Gupta VB. Cerebrospinal fluid biomarkers for understanding multiple aspects of Alzheimer's disease pathogenesis. Cell Mol Life Sci 2019; 76:1833-1863. [PMID: 30770953 PMCID: PMC11105672 DOI: 10.1007/s00018-019-03040-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is a multifactorial age-related brain disease. Numerous pathological events run forth in the brain leading to AD. There is an initial long, dormant phase before the clinical symptoms become evident. There is a need to diagnose the disease at the preclinical stage since therapeutic interventions are most likely to be effective if initiated early. Undoubtedly, the core cerebrospinal fluid (CSF) biomarkers have a good diagnostic accuracy and have been used in clinical trials as end point measures. However, looking into the multifactorial nature of AD and the overlapping pathology with other forms of dementia, it is important to integrate the core CSF biomarkers with a broader panel of other biomarkers reflecting different aspects of pathology. The review is focused upon a panel of biomarkers that relate to different aspects of AD pathology, as well as various studies that have evaluated their diagnostic potential. The panel includes markers of neurodegeneration: neurofilament light chain and visinin-like protein (VILIP-1); markers of amyloidogenesis and brain amyloidosis: apolipoproteins; markers of inflammation: YKL-40 and monocyte chemoattractant protein 1; marker of synaptic dysfunction: neurogranin. These markers can highlight on the state and stage-associated changes that occur in AD brain with disease progression. A combination of these biomarkers would not only aid in preclinical diagnosis, but would also help in identifying early brain changes during the onset of disease. Successful treatment strategies can be devised by understanding the contribution of these markers in different aspects of disease pathogenesis.
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Affiliation(s)
- Kunal Dhiman
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, Australia
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute, London, UK
| | - Ralph N Martins
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, Australia
- Australian Alzheimer's Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, 8 Verdun Street, Nedlands, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
- KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
| | - Veer Bala Gupta
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, Australia.
- School of Medicine, Deakin University, Geelong, 3220, VIC, Australia.
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183
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Shen XN, Niu LD, Wang YJ, Cao XP, Liu Q, Tan L, Zhang C, Yu JT. Inflammatory markers in Alzheimer's disease and mild cognitive impairment: a meta-analysis and systematic review of 170 studies. J Neurol Neurosurg Psychiatry 2019; 90:590-598. [PMID: 30630955 DOI: 10.1136/jnnp-2018-319148] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/05/2018] [Accepted: 12/10/2018] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Inflammation plays a crucial role in the pathogenesis of mild cognitive impairment (MCI) and Alzheimer's disease (AD). Our study aimed to analyse previous inconsistent results of inflammatory markers in AD and MCI quantitatively. METHODS Studies reporting concentrations of peripheral or cerebrospinal fluid (CSF) markers were included, and eligible data on AD, MCI and control were extracted. Pooled Hedges's g was adopted to illustrate comparisons, and various confounding factors were used to explore sources of heterogeneity. RESULTS A total of 170 studies were included in the meta-analysis and systematic review, which demonstrated increased peripheral levels of high-sensitivity C reactive protein (Hedges's g 0.281, p<0.05), interleukin-6 (IL-6) (0.429, p<0.005), soluble tumour necrosis factor receptor 1 (sTNFR1) (0.763, p<0.05), soluble tumour necrosis factor receptor 2 (sTNFR2) (0.354, p<0.005), alpha1-antichymotrypsin (α1-ACT) (1.217, p<0.005), IL-1β (0.615, p<0.05) and soluble CD40 ligand (0.868, p<0.005), and CSF levels of IL-10 (0.434, p<0.05), monocyte chemoattractant protein-1 (MCP-1) (0.798, p<0.005), transforming growth factor-beta 1 (1.009, p<0.05), soluble triggering receptor expressed on myeloid cells2 (sTREM2) (0.587, p<0.001), YKL-40 (0.849, p<0.001), α1-ACT (0.638, p<0.001), nerve growth factor (5.475, p<0.005) and visinin-like protein-1 (VILIP-1) (0.677, p<0.005), in AD compared with the control. Higher levels of sTNFR2 (0.265, p<0.05), IL-6 (0.129, p<0.05) and MCP-1 (0.779, p<0.05) and lower levels of IL-8 (-1.293, p<0.05) in the periphery, as well as elevated concentrations of YKL-40 (0.373, p<0.05), VILIP-1 (0.534, p<0.005) and sTREM2 (0.695, p<0.05) in CSF, were shown in MCI compared with the control. Additionally, increased peripheral sTNFR1 (0.582, p<0.05) and sTNFR2 (0.254, p<0.05) levels were observed in AD compared with MCI. CONCLUSION Significantly altered levels of inflammatory markers were verified in comparison between AD, MCI and control, supporting the notion that AD and MCI are accompanied by inflammatory responses in both the periphery and CSF.
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Affiliation(s)
- Xue-Ning Shen
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Li-Dong Niu
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Yan-Jiang Wang
- Department of Neurology and Center for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Xi-Peng Cao
- Clinical Research Center, Qingdao Municipal Hospital, Qingdao, China
| | - Qiang Liu
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Can Zhang
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease (MIND), Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Jin-Tai Yu
- Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
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184
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Pleiotropic neuroprotective effects of taxifolin in cerebral amyloid angiopathy. Proc Natl Acad Sci U S A 2019; 116:10031-10038. [PMID: 31036637 DOI: 10.1073/pnas.1901659116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cerebral amyloid angiopathy (CAA) results from amyloid-β deposition in the cerebrovasculature. It is frequently accompanied by Alzheimer's disease and causes dementia. We recently demonstrated that in a mouse model of CAA, taxifolin improved cerebral blood flow, promoted amyloid-β removal from the brain, and prevented cognitive dysfunction when administered orally. Here we showed that taxifolin inhibited the intracerebral production of amyloid-β through suppressing the ApoE-ERK1/2-amyloid-β precursor protein axis, despite the low permeability of the blood-brain barrier to taxifolin. Higher expression levels of triggering receptor expressed on myeloid cell 2 (TREM2) were associated with the exacerbation of inflammation in the brain. Taxifolin suppressed inflammation, alleviating the accumulation of TREM2-expressing cells in the brain. It also mitigated glutamate levels and oxidative tissue damage and reduced brain levels of active caspases, indicative of apoptotic cell death. Thus, the oral administration of taxifolin had intracerebral pleiotropic neuroprotective effects on CAA through suppressing amyloid-β production and beneficially modulating proinflammatory microglial phenotypes.
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185
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McQuade A, Blurton-Jones M. Microglia in Alzheimer's Disease: Exploring How Genetics and Phenotype Influence Risk. J Mol Biol 2019; 431:1805-1817. [PMID: 30738892 PMCID: PMC6475606 DOI: 10.1016/j.jmb.2019.01.045] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 01/25/2023]
Abstract
Research into the function of microglia has dramatically accelerated during the last few years, largely due to recent genetic findings implicating microglia in virtually every neurodegenerative disorder. In Alzheimer's disease (AD), a majority of risk loci discovered through genome-wide association studies were found in or near genes expressed most highly in microglia leading to the hypothesis that microglia play a much larger role in disease progression than previously thought. From this body of work produced in the last several years, we find that almost every function of microglia has been proposed to influence the progression of AD from altered phagocytosis and synaptic pruning to cytokine secretion and changes in trophic support. By studying key Alzheimer's risk genes such as TREM2, CD33, ABCA7, and MS4A6A, we will be able to distinguish true disease-modulatory pathways from the full range of microglial-related functions. To successfully carry out these experiments, more advanced microglial models are needed. Microglia are quite sensitive to their local environment, suggesting the need to more fully recapitulate an in vivo environment to study this highly plastic cell type. Likely only by combining the above approaches will the field fully elucidate the molecular pathways that regulate microglia and influence neurodegeneration, in turn uncovering potential new targets for future therapeutic development.
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Affiliation(s)
- Amanda McQuade
- Department of Neurobiology & Behavior, University of California Irvine, Irvine, CA 92697, USA; Sue and Bill Gross Stem Cell Research Center, University of California Irvine, Irvine, CA 92697, USA; Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, CA 92697, USA
| | - Mathew Blurton-Jones
- Department of Neurobiology & Behavior, University of California Irvine, Irvine, CA 92697, USA; Sue and Bill Gross Stem Cell Research Center, University of California Irvine, Irvine, CA 92697, USA; Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, CA 92697, USA.
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186
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Hammond TR, Marsh SE, Stevens B. Immune Signaling in Neurodegeneration. Immunity 2019; 50:955-974. [PMID: 30995509 PMCID: PMC6822103 DOI: 10.1016/j.immuni.2019.03.016] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/17/2019] [Accepted: 03/18/2019] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases of the central nervous system progressively rob patients of their memory, motor function, and ability to perform daily tasks. Advances in genetics and animal models are beginning to unearth an unexpected role of the immune system in disease onset and pathogenesis; however, the role of cytokines, growth factors, and other immune signaling pathways in disease pathogenesis is still being examined. Here we review recent genetic risk and genome-wide association studies and emerging mechanisms for three key immune pathways implicated in disease, the growth factor TGF-β, the complement cascade, and the extracellular receptor TREM2. These immune signaling pathways are important under both healthy and neurodegenerative conditions, and recent work has highlighted new functional aspects of their signaling. Finally, we assess future directions for immune-related research in neurodegeneration and potential avenues for immune-related therapies.
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Affiliation(s)
- Timothy R Hammond
- Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Samuel E Marsh
- Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Beth Stevens
- Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.
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187
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Jensen CS, Bahl JM, Østergaard LB, Høgh P, Wermuth L, Heslegrave A, Zetterberg H, Heegaard NHH, Hasselbalch SG, Simonsen AH. Exercise as a potential modulator of inflammation in patients with Alzheimer's disease measured in cerebrospinal fluid and plasma. Exp Gerontol 2019; 121:91-98. [PMID: 30980923 DOI: 10.1016/j.exger.2019.04.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/04/2019] [Accepted: 04/08/2019] [Indexed: 11/15/2022]
Abstract
BACKGROUND Neuroinflammation is recognized as part of the pathological progression of Alzheimer's disease (AD), but the molecular mechanisms are still not entirely clear. Systemically, physical exercise has shown to have a positive modulating effect on markers of inflammation. It is not known if this general effect also takes place in the central nervous system in AD. The aim of this study was to investigate the effect of 16 weeks of moderate to high-intensity physical exercise on selected biomarkers of inflammation both systemically and in the CNS, in patients with AD. METHODS Plasma and cerebrospinal fluid (CSF) from 198 patients with Alzheimer's disease participating in the Preserving Cognition, Quality of Life, Physical Health and Functional Ability in Alzheimer's Disease: The Effect of Physical Exercise (ADEX) study were analyzed for concentrations of 8‑isoprostane, soluble trigger receptor expressed on myeloid cells 2 (sTREM2), and the MSD v-plex proinflammation panel 1 human containing interferon gamma (IFNγ), Interleukin-10 (IL10), IL12p70, IL13, IL1β, IL2, IL4, IL6, IL8, and tumor necrosis factor alpha (TNFα), before and after a 16-week intervention with physical exercise, and we studied whether changes were modulated by the patients' APOE genotype. RESULTS Most inflammatory markers remained unchanged after exercise. We found an increasing effect of 16 weeks of physical exercise on sTREM2 measured in CSF. Further, IL6 in plasma increased in the exercise group after physical exercise (mean relative change 41.03, SD 76.7), compared to controls (-0.97, SD 49.4). In a sub-analysis according to APOE genotype, we found that in ε4 carriers, exercise had a stabilizing effect on IFNγ concentration with a mean relative change of 7.84 (SD 42.6), as compared to controls (114.7 (SD 188.3), p = 0.038. CONCLUSION Our findings indicate an effect of physical exercise on markers of neuroinflammation in CSF measured by an increase in sTREM2 in patients with AD. Further, there may be a small inflammatory systemic effect related to physical exercise in patients with AD.
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Affiliation(s)
- Camilla Steen Jensen
- Danish Dementia Research Centre, Department of Neurology, Rigshospitalet University of Copenhagen, DK-2100 Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Denmark.
| | | | - Lærke Borg Østergaard
- Danish Dementia Research Centre, Department of Neurology, Rigshospitalet University of Copenhagen, DK-2100 Copenhagen, Denmark.
| | - Peter Høgh
- Department of Clinical Medicine, University of Copenhagen, Denmark; Regional Dementia Research Centre, Department of Neurology, Zealand University Hospital, DK-4000 Roskilde, Denmark.
| | - Lene Wermuth
- Dementia Clinic, Department of Neurology, Odense University Hospital, DK-5000 Odense, Denmark.
| | - Amanda Heslegrave
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, WC1N London, UK; UK Dementia Research Institute at UCL, London WC1E 6BT, UK.
| | - Henrik Zetterberg
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, WC1N London, UK; UK Dementia Research Institute at UCL, London WC1E 6BT, UK; Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, S-431 80 Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, S-431 80 Mölndal, Sweden.
| | - Niels H H Heegaard
- Department of Clinical Biochemistry, Immunology and Genetics, Statens Serum Institut, Copenhagen, Denmark; Department of Clinical Biochemistry, University of Southern Denmark, Odense, Denmark
| | - Steen Gregers Hasselbalch
- Danish Dementia Research Centre, Department of Neurology, Rigshospitalet University of Copenhagen, DK-2100 Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Denmark.
| | - Anja Hviid Simonsen
- Danish Dementia Research Centre, Department of Neurology, Rigshospitalet University of Copenhagen, DK-2100 Copenhagen, Denmark.
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Soluble TREM2 ameliorates pathological phenotypes by modulating microglial functions in an Alzheimer's disease model. Nat Commun 2019; 10:1365. [PMID: 30911003 PMCID: PMC6433910 DOI: 10.1038/s41467-019-09118-9] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 02/19/2019] [Indexed: 12/21/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial surface receptor genetically linked to the risk for Alzheimer’s disease (AD). A proteolytic product, soluble TREM2 (sTREM2), is abundant in the cerebrospinal fluid and its levels positively correlate with neuronal injury markers. To gain insights into the pathological roles of sTREM2, we studied sTREM2 in the brain of 5xFAD mice, a model of AD, by direct stereotaxic injection of recombinant sTREM2 protein or by adeno-associated virus (AAV)-mediated expression. We found that sTREM2 reduces amyloid plaque load and rescues functional deficits of spatial memory and long-term potentiation. Importantly, sTREM2 enhances microglial proliferation, migration, clustering in the vicinity of amyloid plaques and the uptake and degradation of Aβ. Depletion of microglia abolishes the neuroprotective effects of sTREM2. Our study demonstrates a protective role of sTREM2 against amyloid pathology and related toxicity and suggests that increasing sTREM2 can be explored for AD therapy. TREM2 is a genetic risk factor for Alzheimer’s disease, and soluble TREM2 (sTREM2) in the CSF correlates with AD progression. Here the authors study the role of sTREM2 in a mouse model of Alzheimer’s disease, and find it reduces amyloid accumulation and increases the numbers of plaque-associated microglia which correlates with improved behavioural function in the mice.
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Galectin-3, a novel endogenous TREM2 ligand, detrimentally regulates inflammatory response in Alzheimer's disease. Acta Neuropathol 2019; 138:251-273. [PMID: 31006066 PMCID: PMC6660511 DOI: 10.1007/s00401-019-02013-z] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease in which the formation of extracellular aggregates of amyloid beta (Aβ) peptide, fibrillary tangles of intraneuronal tau and microglial activation are major pathological hallmarks. One of the key molecules involved in microglial activation is galectin-3 (gal3), and we demonstrate here for the first time a key role of gal3 in AD pathology. Gal3 was highly upregulated in the brains of AD patients and 5xFAD (familial Alzheimer's disease) mice and found specifically expressed in microglia associated with Aβ plaques. Single-nucleotide polymorphisms in the LGALS3 gene, which encodes gal3, were associated with an increased risk of AD. Gal3 deletion in 5xFAD mice attenuated microglia-associated immune responses, particularly those associated with TLR and TREM2/DAP12 signaling. In vitro data revealed that gal3 was required to fully activate microglia in response to fibrillar Aβ. Gal3 deletion decreased the Aβ burden in 5xFAD mice and improved cognitive behavior. Interestingly, a single intrahippocampal injection of gal3 along with Aβ monomers in WT mice was sufficient to induce the formation of long-lasting (2 months) insoluble Aβ aggregates, which were absent when gal3 was lacking. High-resolution microscopy (stochastic optical reconstruction microscopy) demonstrated close colocalization of gal3 and TREM2 in microglial processes, and a direct interaction was shown by a fluorescence anisotropy assay involving the gal3 carbohydrate recognition domain. Furthermore, gal3 was shown to stimulate TREM2-DAP12 signaling in a reporter cell line. Overall, our data support the view that gal3 inhibition may be a potential pharmacological approach to counteract AD.
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190
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Morris G, Berk M, Maes M, Puri BK. Could Alzheimer's Disease Originate in the Periphery and If So How So? Mol Neurobiol 2019; 56:406-434. [PMID: 29705945 PMCID: PMC6372984 DOI: 10.1007/s12035-018-1092-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 04/17/2018] [Indexed: 12/11/2022]
Abstract
The classical amyloid cascade model for Alzheimer's disease (AD) has been challenged by several findings. Here, an alternative molecular neurobiological model is proposed. It is shown that the presence of the APOE ε4 allele, altered miRNA expression and epigenetic dysregulation in the promoter region and exon 1 of TREM2, as well as ANK1 hypermethylation and altered levels of histone post-translational methylation leading to increased transcription of TNFA, could variously explain increased levels of peripheral and central inflammation found in AD. In particular, as a result of increased activity of triggering receptor expressed on myeloid cells 2 (TREM-2), the presence of the apolipoprotein E4 (ApoE4) isoform, and changes in ANK1 expression, with subsequent changes in miR-486 leading to altered levels of protein kinase B (Akt), mechanistic (previously mammalian) target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3), all of which play major roles in microglial activation, proliferation and survival, there is activation of microglia, leading to the subsequent (further) production of cytokines, chemokines, nitric oxide, prostaglandins, reactive oxygen species, inducible nitric oxide synthase and cyclooxygenase-2, and other mediators of inflammation and neurotoxicity. These changes are associated with the development of amyloid and tau pathology, mitochondrial dysfunction (including impaired activity of the electron transport chain, depleted basal mitochondrial potential and oxidative damage to key tricarboxylic acid enzymes), synaptic dysfunction, altered glycogen synthase kinase-3 (GSK-3) activity, mTOR activation, impairment of autophagy, compromised ubiquitin-proteasome system, iron dyshomeostasis, changes in APP translation, amyloid plaque formation, tau hyperphosphorylation and neurofibrillary tangle formation.
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Affiliation(s)
- Gerwyn Morris
- IMPACT Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, P.O. Box 291, Geelong, Victoria, Australia
| | - Michael Berk
- IMPACT Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, P.O. Box 291, Geelong, Victoria, Australia
- Department of Psychiatry, Level 1 North, Main Block, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Florey Institute for Neuroscience and Mental Health, Kenneth Myer Building, University of Melbourne, 30 Royal Parade, Parkville, Victoria, Australia
- Orygen, The National Centre of Excellence in Youth Mental Health, 35 Poplar Rd, Parkville, Victoria, Australia
| | - Michael Maes
- IMPACT Strategic Research Centre, School of Medicine, Barwon Health, Deakin University, P.O. Box 291, Geelong, Victoria, Australia
- Department of Psychiatry, Chulalongkorn University, Bangkok, Thailand
| | - Basant K Puri
- Department of Medicine, Hammersmith Hospital, Imperial College London, London, UK.
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Takatori S, Wang W, Iguchi A, Tomita T. Genetic Risk Factors for Alzheimer Disease: Emerging Roles of Microglia in Disease Pathomechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1118:83-116. [PMID: 30747419 DOI: 10.1007/978-3-030-05542-4_5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The accumulation of aggregated amyloid β (Aβ) peptides in the brain is deeply involved in Alzheimer disease (AD) pathogenesis. Mutations in APP and presenilins play major roles in Aβ pathology in rare autosomal-dominant forms of AD, whereas pathomechanisms of sporadic AD, accounting for the majority of cases, remain unknown. In this chapter, we review current knowledge on genetic risk factors of AD, clarified by recent advances in genome analysis technology. Interestingly, TREM2 and many genes associated with disease risk are predominantly expressed in microglia, suggesting that these risk factors are involved in pathogenicity through common mechanisms involving microglia. Therefore, we focus on factors closely associated with microglia and discuss their possible roles in pathomechanisms of AD. Furthermore, we review current views on the pathological roles of microglia and emphasize the importance of microglial changes in response to Aβ deposition and mechanisms underlying the phenotypic changes. Importantly, functional outcomes of microglial activation can be both protective and deleterious to neurons. We further describe the involvement of microglia in tau pathology and the activation of other glial cells. Through these topics, we shed light on microglia as a promising target for drug development for AD and other neurological disorders.
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Affiliation(s)
- Sho Takatori
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Wenbo Wang
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Akihiro Iguchi
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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192
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The Role of APOE and TREM2 in Alzheimer's Disease-Current Understanding and Perspectives. Int J Mol Sci 2018; 20:ijms20010081. [PMID: 30587772 PMCID: PMC6337314 DOI: 10.3390/ijms20010081] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/19/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. The extracellular deposits of Amyloid beta (Aβ) in the brain-called amyloid plaques, and neurofibrillary tangles-intracellular tau aggregates, are morphological hallmarks of the disease. The risk for AD is a complicated interplay between aging, genetic risk factors, and environmental influences. One of the Apolipoprotein E (APOE) alleles-APOEε4, is the major genetic risk factor for late-onset AD (LOAD). APOE is the primary cholesterol carrier in the brain, and plays an essential role in lipid trafficking, cholesterol homeostasis, and synaptic stability. Recent genome-wide association studies (GWAS) have identified other candidate LOAD risk loci, as well. One of those is the triggering receptor expressed on myeloid cells 2 (TREM2), which, in the brain, is expressed primarily by microglia. While the function of TREM2 is not fully understood, it promotes microglia survival, proliferation, and phagocytosis, making it important for cell viability and normal immune functions in the brain. Emerging evidence from protein binding assays suggests that APOE binds to TREM2 and APOE-containing lipoproteins in the brain as well as periphery, and are putative ligands for TREM2, thus raising the possibility of an APOE-TREM2 interaction modulating different aspects of AD pathology, potentially in an isoform-specific manner. This review is focusing on the interplay between APOE isoforms and TREM2 in association with AD pathology.
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β-Catenin Pathway Is Involved in TREM2-Mediated Microglial Survival. J Neurosci 2018; 37:7073-7075. [PMID: 28747390 DOI: 10.1523/jneurosci.1087-17.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 06/09/2017] [Accepted: 06/16/2017] [Indexed: 11/21/2022] Open
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Bachiller S, Jiménez-Ferrer I, Paulus A, Yang Y, Swanberg M, Deierborg T, Boza-Serrano A. Microglia in Neurological Diseases: A Road Map to Brain-Disease Dependent-Inflammatory Response. Front Cell Neurosci 2018; 12:488. [PMID: 30618635 PMCID: PMC6305407 DOI: 10.3389/fncel.2018.00488] [Citation(s) in RCA: 428] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia represent a specialized population of macrophages-like cells in the central nervous system (CNS) considered immune sentinels that are capable of orchestrating a potent inflammatory response. Microglia are also involved in synaptic organization, trophic neuronal support during development, phagocytosis of apoptotic cells in the developing brain, myelin turnover, control of neuronal excitability, phagocytic debris removal as well as brain protection and repair. Microglial response is pathology dependent and affects to immune, metabolic. In this review, we will shed light on microglial activation depending on the disease context and the influence of factors such as aging, environment or cell-to-cell interaction.
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Affiliation(s)
- Sara Bachiller
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Itzia Jiménez-Ferrer
- Translational Neurogenetics Unit, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Agnes Paulus
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Yiyi Yang
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Maria Swanberg
- Translational Neurogenetics Unit, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
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195
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Tanaka M, Honda T, Yamakage H, Hata J, Yoshida D, Hirakawa Y, Shibata M, Inoue T, Kusakabe T, Satoh-Asahara N, Ninomiya T. A potential novel pathological implication of serum soluble triggering receptor expressed on myeloid cell 2 in insulin resistance in a general Japanese population: The Hisayama study. Diabetes Res Clin Pract 2018; 146:225-232. [PMID: 30339787 DOI: 10.1016/j.diabres.2018.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 10/01/2018] [Accepted: 10/11/2018] [Indexed: 11/29/2022]
Abstract
AIMS No cohort study has examined the pathological significance of triggering receptor expressed on myeloid cell 2 (TREM2), a cell surface receptor expressed on myeloid lineage cells, and its soluble form, sTREM2, in insulin resistance in a general population. METHODS A total of 2742 community-dwelling Japanese individuals aged ≥40 years were divided into 4 groups according to the serum sTREM2 concentration quartiles. We examined the cross-sectional association of sTREM2 levels with anthropometric parameters and the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS The median sTREM2 concentrations was 255.6 (interquartile range, 162.5-419.2) pg/mL. In multivariate analyses, waist circumference and fat mass index increased with elevating sTREM2 levels (P for trend: <0.001 and 0.02, respectively), but there was no significant association between sTREM2 levels and body mass index and fat-free mass index. Among the subjects without taking antidiabetic medications (n = 2610), greater sTREM2 levels were associated with higher HOMA-IR (P for trend <0.001) even after adjusting for waist circumference, fat mass index, and high-sensitivity C-reactive protein. CONCLUSIONS Our findings suggest that serum sTREM2 had novel pathological roles in insulin resistance, while obesity and inflammation had no substantial effects on the relationship between sTREM2 and insulin resistance in this cohort.
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Affiliation(s)
- Masashi Tanaka
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Takanori Honda
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hajime Yamakage
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Jun Hata
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Daigo Yoshida
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yoichiro Hirakawa
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Mao Shibata
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Takayuki Inoue
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Toru Kusakabe
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Noriko Satoh-Asahara
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Toshiharu Ninomiya
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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Fields JA, Spencer B, Swinton M, Qvale EM, Marquine MJ, Alexeeva A, Gough S, Soontornniyomkij B, Valera E, Masliah E, Achim CL, Desplats P. Alterations in brain TREM2 and Amyloid-β levels are associated with neurocognitive impairment in HIV-infected persons on antiretroviral therapy. J Neurochem 2018; 147:784-802. [PMID: 30152135 PMCID: PMC6310632 DOI: 10.1111/jnc.14582] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/27/2022]
Abstract
Neuroinflammation is a common pathological correlate of HIV-associated neurocognitive disorders (HAND) in individuals on antiretroviral therapy (ART). Triggering receptor expressed on myeloid cells 2 (TREM2) regulates neuroinflammation, clears extracellular Amyloid (A)-β, surveys for damaged neurons, and orchestrates microglial differentiation. TREM2 has not been studied in HIV+ brain tissues. In this retrospective study, we investigated TREM2 expression levels and localization to microglia, Aβ protein levels, and tumor necrosis factor (TNF)-α transcript levels in the frontal cortices of 52 HIV+ decedents. All donors had been on ART; 14 were cognitively normal (CN), 17 had an asymptomatic neurocognitive impairment (ANI), and 21 had a minor neurocognitive disorder (MND). Total TREM2 protein levels were increased in the soluble and decreased in the membrane-enriched fractions of MND brain tissues compared to CN; however, brains from MND Hispanics showed the most robust alterations in TREM2 as well as significantly increased TNF-α mRNA and Aβ levels when compared to CN Hispanics. Significant alterations in the expression of total TREM2 protein and transcripts for TNF-α were not observed in non-Hispanics, despite higher levels of Aβ in the non-Hispanic CN group compared to the non-Hispanic MND groups. These findings show that decreased and increased TREM2 in membrane-bound fractions and in soluble-enriched fractions, respectively, is associated with increased Aβ and neuroinflammation in this cohort of HIV+ brains, particularly those identifying as Hispanics. These findings suggest a role for TREM2 in the brain of HIV+ individuals may deserve more investigation as a biomarker for HAND and as a possible therapeutic target. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Jerel Adam Fields
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Brian Spencer
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Mary Swinton
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Emma Martine Qvale
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - María J. Marquine
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Arina Alexeeva
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Sarah Gough
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Benchawanna Soontornniyomkij
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Elvira Valera
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Eliezer Masliah
- Department of Pathology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Cristian L. Achim
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
- Department of Pathology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
| | - Paula Desplats
- Department of Pathology, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, United States of America
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Zheng H, Cheng B, Li Y, Li X, Chen X, Zhang YW. TREM2 in Alzheimer's Disease: Microglial Survival and Energy Metabolism. Front Aging Neurosci 2018; 10:395. [PMID: 30532704 PMCID: PMC6265312 DOI: 10.3389/fnagi.2018.00395] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/13/2018] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is the leading cause of age-related dementia among the elderly population. Recent genetic studies have identified rare variants of the gene encoding the triggering receptor expressed on myeloid cells-2 (TREM2) as significant genetic risk factors in late-onset AD (LOAD). TREM2 is specifically expressed in brain microglia and modulates microglial functions in response to key AD pathologies such as amyloid-β (Aβ) plaques and tau tangles. In this review article, we discuss recent research progress in our understanding on the role of TREM2 in microglia and its relevance to AD pathologies. In addition, we discuss evidence describing new TREM2 ligands and the role of TREM2 signaling in microglial survival and energy metabolism. A comprehensive understanding of TREM2 function in the pathogenesis of AD offers a unique opportunity to explore the potential of this microglial receptor as an alternative target in AD therapy.
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Affiliation(s)
- Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China.,Shenzhen Research Institute, Xiamen University, Shenzhen, China
| | - Baoying Cheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Yanfang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China.,Shenzhen Research Institute, Xiamen University, Shenzhen, China
| | - Xin Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
| | - Xiaofen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China.,Shenzhen Research Institute, Xiamen University, Shenzhen, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, China
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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: 321] [Impact Index Per Article: 53.5] [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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Differential effects of partial and complete loss of TREM2 on microglial injury response and tauopathy. Proc Natl Acad Sci U S A 2018; 115:10172-10177. [PMID: 30232263 PMCID: PMC6176614 DOI: 10.1073/pnas.1811411115] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Alzheimer's disease (AD), the most common form of dementia, is characterized by the abnormal accumulation of amyloid plaques and hyperphosphorylated tau aggregates, as well as microgliosis. Hemizygous missense variants in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) are associated with elevated risk for developing late-onset AD. These variants are hypothesized to result in loss of function, mimicking TREM2 haploinsufficiency. However, the consequences of TREM2 haploinsufficiency on tau pathology and microglial function remain unknown. We report the effects of partial and complete loss of TREM2 on microglial function and tau-associated deficits. In vivo imaging revealed that microglia from aged TREM2-haploinsufficient mice show a greater impairment in their injury response compared with microglia from aged TREM2-KO mice. In transgenic mice expressing mutant human tau, TREM2 haploinsufficiency, but not complete loss of TREM2, increased tau pathology. In addition, whereas complete TREM2 deficiency protected against tau-mediated microglial activation and atrophy, TREM2 haploinsufficiency elevated expression of proinflammatory markers and exacerbated atrophy at a late stage of disease. The differential effects of partial and complete loss of TREM2 on microglial function and tau pathology provide important insights into the critical role of TREM2 in AD pathogenesis.
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