51
|
Rauchmann BS, Schneider-Axmann T, Alexopoulos P, Perneczky R. CSF soluble TREM2 as a measure of immune response along the Alzheimer's disease continuum. Neurobiol Aging 2019; 74:182-190. [PMID: 30458365 PMCID: PMC6331262 DOI: 10.1016/j.neurobiolaging.2018.10.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/28/2018] [Accepted: 10/17/2018] [Indexed: 01/25/2023]
Abstract
TREM2 was suggested to be an important regulator of microglia during neurodegeneration, but previous studies report conflicting results in relation to soluble TREM2 (sTREM2) in cerebrospinal fluid (CSF) when using clinical criteria to classify Alzheimer's disease (AD). The present study explores sTREM2 CSF levels and their associations with other biomarkers and cognitive measures in a prospective AD cohort. Based on the available CSF biomarker information, 497 subjects were classified according to the 2018 National Institute on Aging-Alzheimer's Association research framework guidelines, which group biomarkers into those of amyloid-β deposition, tau pathology, and neurodegeneration. CSF sTREM2 concentrations were associated with markers of neurodegeneration and fibrillar tau pathology, but not amyloidosis; sTREM2 concentrations were increased in total tau-positive versus -negative individuals; sTREM2 was not related to cognitive and other biomarker changes over time; and sTREM2 concentrations increased over time in total tau-positive versus -negative individuals with AD pathophysiology. The present study provides evidence in support of sTREM2 in CSF as a marker of neuroinflammation across the spectrum of early clinical AD. sTREM2 is linked to neuronal injury and may therefore offer complementary information relevant for diagnostic purposes and novel treatment approaches targeting the immune system in AD.
Collapse
Affiliation(s)
- Boris-Stephan Rauchmann
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany; Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Thomas Schneider-Axmann
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Panagiotis Alexopoulos
- Department of Psychiatry, University Hospital of Rion, University of Patras, Patras, Greece; Department of Psychiatry and Psychotherapy, Technische Universität München, Munich, Germany
| | - Robert Perneczky
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany; Ageing Epidemiology Research Unit, School of Public Health, Imperial College London, London, UK.
| |
Collapse
|
52
|
Suárez-Calvet M, Morenas-Rodríguez E, Kleinberger G, Schlepckow K, Araque Caballero MÁ, Franzmeier N, Capell A, Fellerer K, Nuscher B, Eren E, Levin J, Deming Y, Piccio L, Karch CM, Cruchaga C, Shaw LM, Trojanowski JQ, Weiner M, Ewers M, Haass C. Early increase of CSF sTREM2 in Alzheimer's disease is associated with tau related-neurodegeneration but not with amyloid-β pathology. Mol Neurodegener 2019; 14:1. [PMID: 30630532 PMCID: PMC6327425 DOI: 10.1186/s13024-018-0301-5] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/04/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND TREM2 is a transmembrane receptor that is predominantly expressed by microglia in the central nervous system. Rare variants in the TREM2 gene increase the risk for late-onset Alzheimer's disease (AD). Soluble TREM2 (sTREM2) resulting from shedding of the TREM2 ectodomain can be detected in the cerebrospinal fluid (CSF) and is a surrogate measure of TREM2-mediated microglia function. CSF sTREM2 has been previously reported to increase at different clinical stages of AD, however, alterations in relation to Amyloid β-peptide (Aβ) deposition or additional pathological processes in the amyloid cascade (such as tau pathology or neurodegeneration) remain unclear. In the current cross-sectional study, we employed the biomarker-based classification framework recently proposed by the NIA-AA consensus guidelines, in combination with clinical staging, in order to examine the CSF sTREM2 alterations at early asymptomatic and symptomatic stages of AD. METHODS A cross-sectional study of 1027 participants of the Alzheimer's Disease Imaging Initiative (ADNI) cohort, including 43 subjects carrying TREM2 rare genetic variants, was conducted to measure CSF sTREM2 using a previously validated enzyme-linked immunosorbent assay (ELISA). ADNI participants were classified following the A/T/N framework, which we implemented based on the CSF levels of Aβ1-42 (A), phosphorylated tau (T) and total tau as a marker of neurodegeneration (N), at different clinical stages defined by the clinical dementia rating (CDR) score. RESULTS CSF sTREM2 differed between TREM2 variants, whereas the p.R47H variant had higher CSF sTREM2, p.L211P had lower CSF sTREM2 than non-carriers. We found that CSF sTREM2 increased in early symptomatic stages of late-onset AD but, unexpectedly, we observed decreased CSF sTREM2 levels at the earliest asymptomatic phase when only abnormal Aβ pathology (A+) but no tau pathology or neurodegeneration (TN-), is present. CONCLUSIONS Aβ pathology (A) and tau pathology/neurodegeneration (TN) have differing associations with CSF sTREM2. While tau-related neurodegeneration is associated with an increase in CSF sTREM2, Aβ pathology in the absence of downstream tau-related neurodegeneration is associated with a decrease in CSF sTREM2.
Collapse
Affiliation(s)
- Marc Suárez-Calvet
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany. .,Barcelonaβeta Brain Research Center (BBRC), Pasqual Maragall Foundation, Barcelona, Catalonia, Spain.
| | - Estrella Morenas-Rodríguez
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Department of Neurology, Institut d'Investigacions Biomèdiques, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Catalonia, Spain
| | - Gernot Kleinberger
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Kai Schlepckow
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Miguel Ángel Araque Caballero
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nicolai Franzmeier
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anja Capell
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katrin Fellerer
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Brigitte Nuscher
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Erden Eren
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany.,Izmir International Biomedicine and Genome Institute Dokuz Eylul University, Izmir, Turkey.,Department of Neuroscience, Institute of Health Sciences, Dokuz Eylul University, Izmir, Turkey
| | - Johannes Levin
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Yuetiva Deming
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA
| | - Laura Piccio
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA
| | - Celeste M Karch
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA.,Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA.,Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA
| | - Leslie M Shaw
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Neurodegenerative Disease Research, Institute on Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Center for Neurodegenerative Disease Research, Institute on Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Weiner
- University of California at San Francisco, San Francisco, CA, USA
| | - Michael Ewers
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Haass
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany. .,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany. .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | | |
Collapse
|
53
|
Ohara T, Hata J, Tanaka M, Honda T, Yamakage H, Yoshida D, Inoue T, Hirakawa Y, Kusakabe T, Shibata M, Teraoka T, Kitazono T, Kanba S, Satoh-Asahara N, Ninomiya T. Serum Soluble Triggering Receptor Expressed on Myeloid Cells 2 as a Biomarker for Incident Dementia: The Hisayama Study. Ann Neurol 2018; 85:47-58. [PMID: 30485483 DOI: 10.1002/ana.25385] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To investigate the association between serum soluble triggering receptor expressed on myeloid cells 2 (sTREM2), a soluble type of an innate immune receptor expressed on the microglia, and the risk of dementia. METHODS A total of 1,349 Japanese community residents aged 60 and older without dementia were followed prospectively for 10 years (2002-2012). Serum sTREM2 levels were quantified by using an enzyme-linked immunosorbent assay and divided into quartiles. Cox proportional hazards model was used to estimate the hazard ratios (HRs) of serum sTREM2 levels on the risk of dementia. RESULTS During the follow-up, 300 subjects developed all-cause dementia; 193 had Alzheimer's disease (AD), and 85 had vascular dementia (VaD). The age- and sex-adjusted incidences of all-cause dementia, AD, and VaD elevated significantly with higher serum sTREM2 levels (all p for trend < 0.012). These associations were not altered after adjustment for confounding factors, including high-sensitive C-reactive protein. Subjects with the highest quartile of serum sTREM2 levels had significantly higher multivariable-adjusted risks of developing all-cause dementia, AD, and VaD than those with the lowest quartile (HR = 2.03, 95% confidence interval [CI] = 1.39-2.97, p < 0.001 for all-cause dementia; HR = 1.62, 95% CI = 1.02-2.55, p = 0.04 for AD; HR = 2.85, 95% CI = 1.35-6.02, p = 0.006 for VaD). No significant heterogeneity in the association of serum sTREM2 levels with the development of dementia was observed among the other risk factor subgroups (all p for heterogeneity > 0.11). INTERPRETATION The present findings suggest a significant association between increased serum sTREM2 levels and the risk of developing all-cause dementia, AD, and VaD in the general elderly Japanese population. ANN NEUROL 2019;85:47-58.
Collapse
Affiliation(s)
- Tomoyuki Ohara
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Jun Hata
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Masashi Tanaka
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto
| | - Takanori Honda
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Hajime Yamakage
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto
| | - Daigo Yoshida
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Takayuki Inoue
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto
| | - Yoichiro Hirakawa
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Toru Kusakabe
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto
| | - Mao Shibata
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | | | - Takanari Kitazono
- Department of Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Shigenobu Kanba
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| | - Noriko Satoh-Asahara
- Department of Endocrinology, Metabolism, and Hypertension Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto
| | - Toshiharu Ninomiya
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka.,Department of Center for Cohort Studies, Graduate School of Medical Sciences, Kyushu University, Fukuoka
| |
Collapse
|
54
|
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.
Collapse
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
| |
Collapse
|
55
|
Katsumoto A, Takeuchi H, Takahashi K, Tanaka F. Microglia in Alzheimer's Disease: Risk Factors and Inflammation. Front Neurol 2018; 9:978. [PMID: 30498474 PMCID: PMC6249341 DOI: 10.3389/fneur.2018.00978] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/30/2018] [Indexed: 01/28/2023] Open
Abstract
Microglia are resident immune cells in the central nervous system (CNS) that originate from myeloid progenitor cells in the embryonic yolk sac and are maintained independently of circulating monocytes throughout life. In the healthy state, microglia are highly dynamic and control the environment by rapidly extending and retracting their processes. When the CNS is inflamed, microglia can give rise to macrophages, but the regulatory mechanisms underlying this process have not been fully elucidated. Recent genetic studies have suggested that microglial function is compromised in Alzheimer's disease (AD), and that environmental factors such as diet and brain injury also affect microglial activation. In addition, studies of triggering receptor expressed on myeloid cells 2-deficiency in AD mice revealed heterogeneous microglial reactions at different disease stages, complicating the therapeutic strategy for AD. In this paper, we describe the relationship between genetic and environmental risk factors and the roles of microglia in AD pathogenesis, based on studies performed in human patients and animal models. We also discuss the mechanisms of inflammasomes and neurotransmitters in microglia, which accelerate the development of amyloid-β and tau pathology.
Collapse
Affiliation(s)
- Atsuko Katsumoto
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Hideyuki Takeuchi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Keita Takahashi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Fumiaki Tanaka
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| |
Collapse
|
56
|
|
57
|
Carbajosa G, Malki K, Lawless N, Wang H, Ryder JW, Wozniak E, Wood K, Mein CA, Dobson RJB, Collier DA, O'Neill MJ, Hodges AK, Newhouse SJ. Loss of Trem2 in microglia leads to widespread disruption of cell coexpression networks in mouse brain. Neurobiol Aging 2018; 69:151-166. [PMID: 29906661 PMCID: PMC6075941 DOI: 10.1016/j.neurobiolaging.2018.04.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/26/2018] [Accepted: 04/28/2018] [Indexed: 12/19/2022]
Abstract
Rare heterozygous coding variants in the triggering receptor expressed in myeloid cells 2 (TREM2) gene, conferring increased risk of developing late-onset Alzheimer's disease, have been identified. We examined the transcriptional consequences of the loss of Trem2 in mouse brain to better understand its role in disease using differential expression and coexpression network analysis of Trem2 knockout and wild-type mice. We generated RNA-Seq data from cortex and hippocampus sampled at 4 and 8 months. Using brain cell-type markers and ontology enrichment, we found subnetworks with cell type and/or functional identity. We primarily discovered changes in an endothelial gene-enriched subnetwork at 4 months, including a shift toward a more central role for the amyloid precursor protein gene, coupled with widespread disruption of other cell-type subnetworks, including a subnetwork with neuronal identity. We reveal an unexpected potential role of Trem2 in the homeostasis of endothelial cells that goes beyond its known functions as a microglial receptor and signaling hub, suggesting an underlying link between immune response and vascular disease in dementia.
Collapse
Affiliation(s)
- Guillermo Carbajosa
- Department of Biostatistics and Health Informatics, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK.
| | | | | | - Hong Wang
- Eli Lilly and Company, Indianapolis, IN, USA
| | | | - Eva Wozniak
- Barts and the London Genome Centre, John Vane Science Centre, Barts and the London School of Medicine and Dentistry, London, UK
| | - Kristie Wood
- Barts and the London Genome Centre, John Vane Science Centre, Barts and the London School of Medicine and Dentistry, London, UK
| | - Charles A Mein
- Barts and the London Genome Centre, John Vane Science Centre, Barts and the London School of Medicine and Dentistry, London, UK
| | - Richard J B Dobson
- Department of Biostatistics and Health Informatics, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK; NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London, London, UK; Farr Institute of Health Informatics Research, UCL Institute of Health Informatics, University College London, London, UK
| | | | | | - Angela K Hodges
- Maurice Wohl Clinical Neuroscience Institute James Black Centre Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK
| | - Stephen J Newhouse
- Department of Biostatistics and Health Informatics, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK; NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London, London, UK; Farr Institute of Health Informatics Research, UCL Institute of Health Informatics, University College London, London, UK
| |
Collapse
|
58
|
Inflammatory markers of CHMP2B-mediated frontotemporal dementia. J Neuroimmunol 2018; 324:136-142. [PMID: 30193769 DOI: 10.1016/j.jneuroim.2018.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/04/2018] [Accepted: 08/14/2018] [Indexed: 12/27/2022]
Abstract
Histopathological studies and animal models have suggested an inflammatory component in the pathomechanism of the CHMP2B associated frontotemporal dementia (FTD-3). In this cross-sectional study, serum and cerebrospinal fluid were analyzed for inflammatory markers in CHMP2B mutation carriers. Serum levels of CCL4 were increased throughout life. Serum levels of IL-15, CXCL10, CCL22 and TNF-α were significantly associated with cognitive decline, suggesting a peripheral inflammatory response to neurodegeneration. CSF levels of sTREM2 appeared to increase more rapidly with age in CHMP2B mutation carriers. The identification of a peripheral inflammatory response to disease progression supports the involvement of an inflammatory component in FTD-3.
Collapse
|
59
|
The role of TREM2 in Alzheimer's disease and other neurodegenerative disorders. Lancet Neurol 2018; 17:721-730. [PMID: 30033062 DOI: 10.1016/s1474-4422(18)30232-1] [Citation(s) in RCA: 161] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is a genetically complex disorder; rare variants in the triggering receptor expressed on myeloid cells 2 (TREM2) gene have been shown to as much as triple an individual's risk of developing Alzheimer's disease. TREM2 is a transmembrane receptor expressed in cells of the myeloid lineage, and its association with Alzheimer's disease supports the involvement of immune and inflammatory pathways in the cause of the disease, rather than as a consequence of the disease. TREM2 variants associated with Alzheimer's disease induce partial loss of function of the TREM2 protein and alter the behaviour of microglial cells, including their response to amyloid plaques. TREM2 variants have also been shown to cause polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy and frontotemporal dementia. Although the low frequency of TREM2 variants makes it difficult to establish robust genotype-phenotype correlations, such studies are essential to enable a comprehensive understanding of the role of TREM2 in different neurological diseases, with the ultimate goal of developing novel therapeutic approaches.
Collapse
|
60
|
Deming Y, Li Z, Benitez BA, Cruchaga C. Triggering receptor expressed on myeloid cells 2 (TREM2): a potential therapeutic target for Alzheimer disease? Expert Opin Ther Targets 2018; 22:587-598. [PMID: 29889572 DOI: 10.1080/14728222.2018.1486823] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
INTRODUCTION There are currently no effective therapeutics for Alzheimer disease (AD). Clinical trials targeting amyloid beta thus far have shown very little benefit and only in the earliest stages of disease. These limitations have driven research to identify alternative therapeutic targets, one of the most promising is the triggering receptor expressed on myeloid cells 2 (TREM2). Areas covered: Here, we review the literature to-date and discuss the potentials and pitfalls for targeting TREM2 as a potential therapeutic for AD. We focus on research in animal and cell models for AD and central nervous system injury models which may help in understanding the role of TREM2 in disease. Expert opinion: Studies suggest TREM2 plays a key role in AD pathology; however, results have been conflicting about whether TREM2 is beneficial or harmful. More research is necessary before designing TREM2-targeting therapies. Successful therapeutics will most likely be administered early in disease.
Collapse
Affiliation(s)
- Yuetiva Deming
- a Department of Psychiatry , Washington University School of Medicine , St Louis , MO , USA
| | - Zeran Li
- a Department of Psychiatry , Washington University School of Medicine , St Louis , MO , USA
| | - Bruno A Benitez
- b Department of Medicine , Washington University School of Medicine , St Louis , MO , USA
| | - Carlos Cruchaga
- a Department of Psychiatry , Washington University School of Medicine , St Louis , MO , USA.,c Department of Developmental Biology , Washington University School of Medicine , St Louis , MO , USA.,d Knight Alzheimer's Disease Research Center , Washington University School of Medicine , St Louis , MO , USA.,e Hope Center for Neurological Disorders , Washington University School of Medicine , St Louis , MO , USA
| |
Collapse
|
61
|
Bartoletti-Stella A, Baiardi S, Stanzani-Maserati M, Piras S, Caffarra P, Raggi A, Pantieri R, Baldassari S, Caporali L, Abu-Rumeileh S, Linarello S, Liguori R, Parchi P, Capellari S. Identification of rare genetic variants in Italian patients with dementia by targeted gene sequencing. Neurobiol Aging 2018. [DOI: 10.1016/j.neurobiolaging.2018.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
62
|
Schlepckow K, Kleinberger G, Fukumori A, Feederle R, Lichtenthaler SF, Steiner H, Haass C. An Alzheimer-associated TREM2 variant occurs at the ADAM cleavage site and affects shedding and phagocytic function. EMBO Mol Med 2018; 9:1356-1365. [PMID: 28855300 PMCID: PMC5623859 DOI: 10.15252/emmm.201707672] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sequence variations occurring in the gene encoding the triggering receptor expressed on myeloid cells 2 (TREM2) support an essential function of microglia and innate immunity in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative disorders. TREM2 matures within the secretory pathway, and its ectodomain is shed on the plasma membrane. Missense mutations in the immunoglobulin (Ig)‐like domain such as p.T66M and p.Y38C retain TREM2 within the endoplasmic reticulum and reduce shedding as well as TREM2‐dependent phagocytosis. Using mass spectrometry, we have now determined the cleavage site of TREM2. TREM2 is shed by proteases of the ADAM (a disintegrin and metalloproteinase domain containing protein) family C‐terminal to histidine 157, a position where an AD‐associated coding variant has been discovered (p.H157Y) in the Han Chinese population. Opposite to the characterized mutations within the Ig‐like domain, such as p.T66M and p.Y38C, the p.H157Y variant within the stalk region leads to enhanced shedding of TREM2. Elevated ectodomain shedding reduces cell surface full‐length TREM2 and lowers TREM2‐dependent phagocytosis. Therefore, two seemingly opposite cellular effects of TREM2 variants, namely reduced versus enhanced shedding, result in similar phenotypic outcomes by reducing cell surface TREM2.
Collapse
Affiliation(s)
- Kai Schlepckow
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gernot Kleinberger
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Akio Fukumori
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Regina Feederle
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Helmholtz Center Munich, German Research Center for Environmental Health, Institute for Diabetes and Obesity, Core Facility Monoclonal Antibody Development, Neuherberg, Germany
| | - Stefan F Lichtenthaler
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Neuroproteomics, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.,Institute for Advanced Study, Technische Universität München, Garching, Germany
| | - Harald Steiner
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Christian Haass
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| |
Collapse
|
63
|
Ng ASL, Tan YJ, Yi Z, Tandiono M, Chew E, Dominguez J, Macas M, Ng E, Hameed S, Ting S, Tan EK, Foo JN, Kandiah N. Targeted exome sequencing reveals homozygous TREM2 R47C mutation presenting with behavioral variant frontotemporal dementia without bone involvement. Neurobiol Aging 2018; 68:160.e15-160.e19. [PMID: 29748150 DOI: 10.1016/j.neurobiolaging.2018.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 02/19/2018] [Accepted: 04/07/2018] [Indexed: 10/17/2022]
Abstract
To identify genes associated with frontotemporal dementia (FTD) in South-East Asia, targeted exome sequencing and C9orf72 genotyping was performed in 198 subjects (52 patients with FTD and 146 healthy controls) who were screened for mutations in 12 FTD-associated genes. We detected a homozygous TREM2 R47C mutation in a patient with behavioral variant FTD without bone cysts or bone-associated phenotype. Two novel nonsense GRN mutations in 3 FTD patients from the Philippines were detected, but no known pathogenic mutations in other FTD-associated genes were found. In 45 subjects screened for C9orf72 repeat expansions, no pathogenic expansion (≥30 repeats) was identified, but there was a higher proportion of intermediate length (≥10-29 repeats) alleles in patients compared with controls (8/90 alleles, 8.9% vs. 9/164 alleles, 5.5%). Overall, we detected a mutation rate of 7.7% (4/52 patients) in our cohort. Given recent findings of enrichment of rare TREM2 variants (including R47C) in Alzheimer's disease, it is notable that we detected a homozygous TREM2 R47C carrier presenting with an FTD rather than an Alzheimer's disease phenotype.
Collapse
Affiliation(s)
- Adeline S L Ng
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore.
| | - Yi Jayne Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore
| | - Zhao Yi
- Department of Clinical Research, Singapore General Hospital, Bukit Merah, Singapore
| | - Moses Tandiono
- Human Genetics, Genome Institute of Singapore, A*STAR, Singapore
| | - Elaine Chew
- Human Genetics, Genome Institute of Singapore, A*STAR, Singapore
| | - Jacqueline Dominguez
- Institute for Neurological Sciences, St Luke's Medical Centre, Quezon City, Philippines
| | - Mabel Macas
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Bukit Merah, Singapore
| | - Ebonne Ng
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Bukit Merah, Singapore
| | - Shahul Hameed
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Bukit Merah, Singapore
| | - Simon Ting
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Bukit Merah, Singapore
| | - Eng King Tan
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Bukit Merah, Singapore; Duke-NUS Graduate Medical School, Singapore
| | - Jia Nee Foo
- Human Genetics, Genome Institute of Singapore, A*STAR, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
| | - Nagaendran Kandiah
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore; Duke-NUS Graduate Medical School, Singapore
| |
Collapse
|
64
|
Peplonska B, Berdynski M, Mandecka M, Barczak A, Kuzma-Kozakiewicz M, Barcikowska M, Zekanowski C. TREM2 variants in neurodegenerative disorders in the Polish population. Homozygosity and compound heterozygosity in FTD patients. Amyotroph Lateral Scler Frontotemporal Degener 2018; 19:407-412. [PMID: 29557178 DOI: 10.1080/21678421.2018.1451894] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Activation of the TREM2 receptor on microglia stimulates phagocytosis and decreases the microglial proinflammatory response. Mutations in exon 2 of the TREM2 gene have been reported to be associated with various neurodegenerative diseases characterized by chronic inflammation. The aim of our study was to evaluate exon 2 of TREM2 gene variants as a putative genetic risk factor for Alzheimer's disease (AD), frontotemporal dementia (FTD), and amyotrophic lateral sclerosis (ALS) in the Polish population. The results were interpreted using previously published data, especially highlighting differences in the prevalence of the variants among Caucasian subpopulations across different geographic regions. The DNA sequence of exon 2 of TREM2 was analyzed in 811 subjects (274 AD, 135 FTD, 194 ALS patients, and 208 neurologically healthy controls). Nine heterozygous variants were detected, including two novel ones: p.G29 = and c.41-2_3insA, found respectively in a control and an ALS patient. Additionally, we identified one homozygous and two compound heterozygous FTD patients. We confirm previous data that homozygous and compound heterozygous TREM2 mutations can be causative for FTD.
Collapse
Affiliation(s)
- Beata Peplonska
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| | - Mariusz Berdynski
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| | - Monika Mandecka
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| | - Anna Barczak
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| | - Magdalena Kuzma-Kozakiewicz
- b Department of Neurology , and.,c Neurodegenerative Diseases Research Group Medical University of Warsaw , Warsaw , Poland
| | - Maria Barcikowska
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| | - Cezary Zekanowski
- a Department of Neurodegenerative Disorders , Mossakowski Medical Research Centre Polish Academy of Sciences , Warsaw , Poland
| |
Collapse
|
65
|
Su WH, Shi ZH, Liu SL, Wang XD, Liu S, Ji Y. The rs75932628 and rs2234253 polymorphisms of the TREM2 gene were associated with susceptibility to frontotemporal lobar degeneration in Caucasian populations. Ann Hum Genet 2018; 82:177-185. [PMID: 29322490 DOI: 10.1111/ahg.12241] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 09/30/2017] [Accepted: 11/29/2017] [Indexed: 12/29/2022]
Abstract
Polymorphisms of the triggering receptor expressed on myeloid cells 2 (TREM2) gene have been reported to be potentially associated with the risks of developing frontotemporal lobar degeneration (FTLD), with inconsistent conclusions. This study aims to comprehensively investigate the potential role of TREM2 variants in FTLD risks via a meta-analysis. We included a total of eight eligible articles. For TREM2 rs75932628, we observed a significantly increased FTLD risk in the models of T vs. C [Association Test, odds ratio (OR) = 2.43, 95% confidence interval (CI) = 1.43∼4.14, P = 0.001], CT vs. CC (OR = 2.27, 95% CI = 1.39∼3.71, P = 0.001), CT + TT vs. CC (OR = 2.27, 95% CI = 1.38∼3.71, P = 0.001), and Carrier T vs. C (OR = 2.26, 95% CI = 1.38∼3.69, P = 0.001). Similarly, we observed positive results for TREM2 rs2234253 in all of the genetic models (all OR > 1, P = 0.030). Nevertheless, we did not observe any statistical difference between the case and control groups in the pooled analyses of TREM2 rs142232675 and rs143332484 (all P > 0.05). Our findings identified the rs75932628 and rs2234253 polymorphisms of the TREM2 gene as risk factors for FTLD in Caucasian populations.
Collapse
Affiliation(s)
- Wen-Hua Su
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| | - Zhi-Hong Shi
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| | - Shu-Ling Liu
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| | - Xiao-Dan Wang
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| | - Shuai Liu
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| | - Yong Ji
- Department of Neurology, Tianjin Huanhu Hospital, Tianjin, China.,Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin, China
| |
Collapse
|
66
|
Abstract
Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive changes in behavior, personality, and language with involvement of the frontal and temporal regions of the brain. About 40% of FTD cases have a positive family history, and about 10% of these cases are inherited in an autosomal-dominant pattern. These gene defects present with distinct clinical phenotypes. As the diagnosis of FTD becomes more recognizable, it will become increasingly important to keep these gene mutations in mind. In this chapter, we review the genes with known associations to FTD. We discuss protein functions, mutation frequencies, clinical phenotypes, imaging characteristics, and pathology associated with these genes.
Collapse
Affiliation(s)
- Jessica Deleon
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, United States
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, United States.
| |
Collapse
|
67
|
Suárez-Calvet M, Araque Caballero MÁ, Kleinberger G, Bateman RJ, Fagan AM, Morris JC, Levin J, Danek A, Ewers M, Haass C. Early changes in CSF sTREM2 in dominantly inherited Alzheimer's disease occur after amyloid deposition and neuronal injury. Sci Transl Med 2017; 8:369ra178. [PMID: 27974666 DOI: 10.1126/scitranslmed.aag1767] [Citation(s) in RCA: 185] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/23/2016] [Indexed: 12/30/2022]
Abstract
Emerging evidence supports a role for innate immunity and microglia in Alzheimer's disease (AD) pathophysiology. However, no marker related to microglia has been included in the temporal evolution models of AD. TREM2 is a transmembrane protein involved in innate immunity and is selectively expressed by microglia and genetically linked to AD and other neurodegenerative disorders. Its ectodomain is released by proteolysis as a soluble variant (sTREM2) and can be detected in the cerebrospinal fluid (CSF). In patients with autosomal dominant AD, we tested how many years before the expected symptom onset did CSF sTREM2 increase in mutation carriers (MCs) compared to noncarriers (NCs). We also determined the temporal sequence of changes in CSF sTREM2 and markers for amyloid deposition and neurodegeneration as well as cognitive performance. We included 218 participants consisting of 127 MC and 91 NC siblings from the Dominantly Inherited Alzheimer Network. We observed that CSF sTREM2 increased in MCs compared to NCs 5 years before the expected symptom onset and this difference remained significant until 5 years after the expected symptom onset. Changes in CSF sTREM2 occurred after alterations were observed in markers for brain amyloidosis and neuronal injury. We propose that microglial activation occurs several years before the expected symptom onset, but after amyloidosis and neuronal injury have already occurred.
Collapse
Affiliation(s)
- Marc Suárez-Calvet
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Biomedical Center, Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Miguel Ángel Araque Caballero
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gernot Kleinberger
- Biomedical Center, Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Randall J Bateman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Anne M Fagan
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - John C Morris
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Johannes Levin
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Adrian Danek
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Ewers
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany. .,Biomedical Center, Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | | |
Collapse
|
68
|
Intracellular trafficking of TREM2 is regulated by presenilin 1. Exp Mol Med 2017; 49:e405. [PMID: 29611543 PMCID: PMC5750471 DOI: 10.1038/emm.2017.200] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/05/2017] [Accepted: 05/31/2017] [Indexed: 01/26/2023] Open
Abstract
Genetic mutations in triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to a variety of neurodegenerative diseases including Alzheimer's disease, amyotrophic lateral sclerosis, frontotemporal dementia and Parkinson's disease. In the brain, TREM2 is highly expressed on the cell surface of microglia, where it can transduce signals to regulate microglial functions such as phagocytosis. To date, mechanisms underlying intracellular trafficking of TREM2 remain elusive. Mutations in the presenilin 1 (PS1) catalytic subunit of the γ-secretase complex have been associated with increased generation of the amyloidogenic Aβ (amyloid-β) 42 peptide through cleavage of the Aβ precursor amyloid precursor protein. Here we found that TREM2 interacts with PS1 in a manner independent of γ-secretase activity. Mutations in TREM2 alter its subcellular localization and affects its interaction with PS1. Upregulation of PS1 reduces, whereas downregulation of PS1 increases, steady-state levels of cell surface TREM2. Furthermore, PS1 overexpression results in attenuated phagocytic uptake of Aβ by microglia, which is reversed by TREM2 overexpression. Our data indicate a novel role for PS1 in regulating TREM2 intracellular trafficking and pathophysiological function.
Collapse
|
69
|
Tang SS, Li J, Tan L, Yu JT. Genetics of Frontotemporal Lobar Degeneration: From the Bench to the Clinic. J Alzheimers Dis 2017; 52:1157-76. [PMID: 27104909 DOI: 10.3233/jad-160236] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Frontotemporal lobar degeneration (FTLD) is a clinically heterogeneous neurodegenerative disease with a strong genetic component. In this review, we summarize most common mutations in MAPT, GRN, and C90RF72, as well as less common mutations in VCP, CHMP2B, TARDBP, FUS gene and so on. Several guidelines have been developed to help gene testing based on genotype-phenotype correlation, the underlying histopathological subtypes, and the neuroanatomic associations. Furthermore, we also summarize molecular pathways implicated by genes and novel targets for FTLD prevention and management in recent years.
Collapse
|
70
|
Bemiller SM, McCray TJ, Allan K, Formica SV, Xu G, Wilson G, Kokiko-Cochran ON, Crish SD, Lasagna-Reeves CA, Ransohoff RM, Landreth GE, Lamb BT. TREM2 deficiency exacerbates tau pathology through dysregulated kinase signaling in a mouse model of tauopathy. Mol Neurodegener 2017; 12:74. [PMID: 29037207 PMCID: PMC5644120 DOI: 10.1186/s13024-017-0216-6] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/09/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Genetic variants of the Triggering Receptor Expressed on Myeloid Cells-2 (TREM2) confer increased risk of developing late-onset Alzheimer's Disease (LOAD) and other neurodegenerative disorders. Recent studies provided insight into the multifaceted roles of TREM2 in regulating extracellular β-amyloid (Aβ) pathology, myeloid cell accumulation, and inflammation observed in AD, yet little is known regarding the role of TREM2 in regulating intracellular microtubule associated protein tau (MAPT; tau) pathology in neurodegenerative diseases and in AD, in particular. RESULTS Here we report that TREM2 deficiency leads to accelerated and exacerbated hyperphosphorylation and aggregation of tau in a humanized mouse model of tauopathy. TREM2 deficiency also results, indirectly, in dramatic widespread dysregulation of neuronal stress kinase pathways. CONCLUSIONS Our results suggest that deficiency of microglial TREM2 leads to heightened tau pathology coupled with widespread increases in activated neuronal stress kinases. These findings offer new insight into the complex, multiple roles of TREM2 in regulating Aβ and tau pathologies.
Collapse
Affiliation(s)
- Shane M Bemiller
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
- Kent State University, School of Biomedical Sciences, Kent, OH, USA.
- Indiana University School of Medicine Stark Neuroscience Research Institute, Indianapolis, IN, USA.
| | - Tyler J McCray
- Indiana University School of Medicine Stark Neuroscience Research Institute, Indianapolis, IN, USA
| | - Kevin Allan
- Department of Neurosciences, Case Western Reserve University, Cleveland, USA
| | - Shane V Formica
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
| | - Guixiang Xu
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
- Indiana University School of Medicine Stark Neuroscience Research Institute, Indianapolis, IN, USA
| | - Gina Wilson
- Department of Neurosciences, Northeastern Ohio Medical University, Rootstown, OH, USA
| | - Olga N Kokiko-Cochran
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
- Department of Neurosciences, The Ohio State University, Columbus, OH, USA
| | - Samuel D Crish
- Department of Neurosciences, Northeastern Ohio Medical University, Rootstown, OH, USA
| | | | | | - Gary E Landreth
- Indiana University School of Medicine Stark Neuroscience Research Institute, Indianapolis, IN, USA
- Department of Neurosciences, Case Western Reserve University, Cleveland, USA
| | - Bruce T Lamb
- Department of Neurosciences, The Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
- Indiana University School of Medicine Stark Neuroscience Research Institute, Indianapolis, IN, USA.
| |
Collapse
|
71
|
Eskandari-Sedighi G, Daude N, Gapeshina H, Sanders DW, Kamali-Jamil R, Yang J, Shi B, Wille H, Ghetti B, Diamond MI, Janus C, Westaway D. The CNS in inbred transgenic models of 4-repeat Tauopathy develops consistent tau seeding capacity yet focal and diverse patterns of protein deposition. Mol Neurodegener 2017; 12:72. [PMID: 28978354 PMCID: PMC5628424 DOI: 10.1186/s13024-017-0215-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/27/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND MAPT mutations cause neurodegenerative diseases such as frontotemporal dementia but, strikingly, patients with the same mutation may have different clinical phenotypes. METHODS Given heterogeneities observed in a transgenic (Tg) mouse line expressing low levels of human (2 N, 4R) P301L Tau, we backcrossed founder stocks of mice to C57BL/6Tac, 129/SvEvTac and FVB/NJ inbred backgrounds to discern the role of genetic versus environmental effects on disease-related phenotypes. RESULTS Three inbred derivatives of a TgTauP301L founder line had similar quality and steady-state quantity of Tau production, accumulation of abnormally phosphorylated 64-68 kDa Tau species from 90 days of age onwards and neuronal loss in aged Tg mice. Variegation was not seen in the pattern of transgene expression and seeding properties in a fluorescence-based cellular assay indicated a single "strain" of misfolded Tau. However, in other regards, the aged Tg mice were heterogeneous; there was incomplete penetrance for Tau deposition despite maintained transgene expression in aged animals and, for animals with Tau deposits, distinctions were noted even within each subline. Three classes of rostral deposition in the cortex, hippocampus and striatum accounted for 75% of pathology-positive mice yet the mean ages of mice scored as class I, II or III were not significantly different and, hence, did not fit with a predictable progression from one class to another defined by chronological age. Two other patterns of Tau deposition designated as classes IV and V, occurred in caudal structures. Other pathology-positive Tg mice of similar age not falling within classes I-V presented with focal accumulations in additional caudal neuroanatomical areas including the locus coeruleus. Electron microscopy revealed that brains of Classes I, II and IV animals all exhibit straight filaments, but with coiled filaments and occasional twisted filaments apparent in Class I. Most strikingly, Class I, II and IV animals presented with distinct western blot signatures after trypsin digestion of sarkosyl-insoluble Tau. CONCLUSIONS Qualitative variations in the neuroanatomy of Tau deposition in genetically constrained slow models of primary Tauopathy establish that non-synchronous, focal events contribute to the pathogenic process. Phenotypic diversity in these models suggests a potential parallel to the phenotypic variation seen in P301L patients.
Collapse
Affiliation(s)
- Ghazaleh Eskandari-Sedighi
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Nathalie Daude
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada
| | - Hristina Gapeshina
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada
| | - David W Sanders
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, USA
| | - Razieh Kamali-Jamil
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Jing Yang
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada
| | - Beipei Shi
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada
| | - Holger Wille
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, USA
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, USA
| | - Christopher Janus
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, USA
| | - David Westaway
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2M8, Canada. .,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
| |
Collapse
|
72
|
Jay TR, von Saucken VE, Landreth GE. TREM2 in Neurodegenerative Diseases. Mol Neurodegener 2017; 12:56. [PMID: 28768545 PMCID: PMC5541421 DOI: 10.1186/s13024-017-0197-5] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/20/2017] [Indexed: 12/12/2022] Open
Abstract
TREM2 variants have been identified as risk factors for Alzheimer's disease (AD) and other neurodegenerative diseases (NDDs). Because TREM2 encodes a receptor exclusively expressed on immune cells, identification of these variants conclusively demonstrates that the immune response can play an active role in the pathogenesis of NDDs. These TREM2 variants also confer the highest risk for developing Alzheimer's disease of any risk factor identified in nearly two decades, suggesting that understanding more about TREM2 function could provide key insights into NDD pathology and provide avenues for novel immune-related NDD biomarkers and therapeutics. The expression, signaling and function of TREM2 in NDDs have been extensively investigated in an effort to understand the role of immune function in disease pathogenesis and progression. We provide a comprehensive review of our current understanding of TREM2 biology, including new insights into the regulation of TREM2 expression, and TREM2 signaling and function across NDDs. While many open questions remain, the current body of literature provides clarity on several issues. While it is still often cited that TREM2 expression is decreased by pro-inflammatory stimuli, it is now clear that this is true in vitro, but inflammatory stimuli in vivo almost universally increase TREM2 expression. Likewise, while TREM2 function is classically described as promoting an anti-inflammatory phenotype, more than half of published studies demonstrate a pro-inflammatory role for TREM2, suggesting that its role in inflammation is much more complex. Finally, these components of TREM2 biology are applied to a discussion of how TREM2 impacts NDD pathologies and the latest assessment of how these findings might be applied to immune-directed clinical biomarkers and therapeutics.
Collapse
Affiliation(s)
- Taylor R. Jay
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
| | - Victoria E. von Saucken
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
| | - Gary E. Landreth
- Department of Neurosciences, Case Western Reserve University, School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106 USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W 15th Street, Indianapolis, IN 46202 USA
| |
Collapse
|
73
|
Yeh FL, Hansen DV, Sheng M. TREM2, Microglia, and Neurodegenerative Diseases. Trends Mol Med 2017; 23:512-533. [DOI: 10.1016/j.molmed.2017.03.008] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 02/15/2017] [Accepted: 03/26/2017] [Indexed: 01/17/2023]
|
74
|
Kleinberger G, Brendel M, Mracsko E, Wefers B, Groeneweg L, Xiang X, Focke C, Deußing M, Suárez-Calvet M, Mazaheri F, Parhizkar S, Pettkus N, Wurst W, Feederle R, Bartenstein P, Mueggler T, Arzberger T, Knuesel I, Rominger A, Haass C. The FTD-like syndrome causing TREM2 T66M mutation impairs microglia function, brain perfusion, and glucose metabolism. EMBO J 2017; 36:1837-1853. [PMID: 28559417 DOI: 10.15252/embj.201796516] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/21/2017] [Accepted: 04/27/2017] [Indexed: 12/31/2022] Open
Abstract
Genetic variants in the triggering receptor expressed on myeloid cells 2 (TREM2) increase the risk for several neurodegenerative diseases including Alzheimer's disease and frontotemporal dementia (FTD). Homozygous TREM2 missense mutations, such as p.T66M, lead to the FTD-like syndrome, but how they cause pathology is unknown. Using CRISPR/Cas9 genome editing, we generated a knock-in mouse model for the disease-associated Trem2 p.T66M mutation. Consistent with a loss-of-function mutation, we observe an intracellular accumulation of immature mutant Trem2 and reduced generation of soluble Trem2 similar to patients with the homozygous p.T66M mutation. Trem2 p.T66M knock-in mice show delayed resolution of inflammation upon in vivo lipopolysaccharide stimulation and cultured macrophages display significantly reduced phagocytic activity. Immunohistochemistry together with in vivo TSPO small animal positron emission tomography (μPET) demonstrates an age-dependent reduction in microglial activity. Surprisingly, perfusion magnetic resonance imaging and FDG-μPET imaging reveal a significant reduction in cerebral blood flow and brain glucose metabolism. Thus, we demonstrate that a TREM2 loss-of-function mutation causes brain-wide metabolic alterations pointing toward a possible function of microglia in regulating brain glucose metabolism.
Collapse
Affiliation(s)
- Gernot Kleinberger
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Eva Mracsko
- NORD Discovery & Translational Area, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Benedikt Wefers
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Linda Groeneweg
- NORD Discovery & Translational Area, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Xianyuan Xiang
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Carola Focke
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Maximilian Deußing
- Department of Nuclear Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Marc Suárez-Calvet
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Fargol Mazaheri
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Samira Parhizkar
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Nadine Pettkus
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Wolfgang Wurst
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Technische Universität München, Freising-Weihenstephan, Germany
| | - Regina Feederle
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Helmholtz Center Munich, German Research Center for Environmental Health, Institute for Diabetes and Obesity, Core Facility Monoclonal Antibody Development, Munich, Germany
| | - Peter Bartenstein
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Department of Nuclear Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Mueggler
- NORD Discovery & Translational Area, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Thomas Arzberger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Irene Knuesel
- NORD Discovery & Translational Area, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Axel Rominger
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Department of Nuclear Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Haass
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| |
Collapse
|
75
|
Varnum MM, Clayton KA, Yoshii-Kitahara A, Yonemoto G, Koro L, Ikezu S, Ikezu T. A split-luciferase complementation, real-time reporting assay enables monitoring of the disease-associated transmembrane protein TREM2 in live cells. J Biol Chem 2017; 292:10651-10663. [PMID: 28490631 DOI: 10.1074/jbc.m116.759159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 04/20/2017] [Indexed: 12/18/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) is a single transmembrane molecule uniquely expressed in microglia. TREM2 mutations are genetically linked to Nasu-Hakola disease and associated with multiple neurodegenerative disorders, including Alzheimer's disease. TREM2 may regulate microglial inflammation and phagocytosis through coupling to the adaptor protein TYRO protein-tyrosine kinase-binding protein (TYROBP). However, there is no functional system for monitoring this protein-protein interaction. We developed a luciferase-based modality for real-time monitoring of TREM2-TYROBP coupling in live cells that utilizes split-luciferase complementation technology based on TREM2 and TYROBP fusion to the C- or N-terminal portion of the Renilla luciferase gene. Transient transfection of human embryonic kidney 293 cells with this reporter vector increased luciferase activity upon stimulation with an anti-TREM2 antibody, which induces their homodimerization. This was confirmed by ELISA-based analysis of the TREM2-TYROBP interaction. Antibody-mediated TREM2 stimulation enhanced spleen tyrosine kinase (SYK) activity and uptake of Staphylococcus aureus in microglial cell line BV-2 in a kinase-dependent manner. Interestingly, the TREM2 T66M mutation significantly enhanced luciferase activity without stimulation, indicating constitutive coupling to TYROBP. Finally, flow cytometry analyses indicated significantly lower surface expression of T66M TREM2 variant than wild type or other TREM2 variants. These results demonstrate that our TREM2 reporter vector is a novel tool for monitoring the TREM2-TYROBP interaction in real time.
Collapse
Affiliation(s)
- Megan M Varnum
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - Kevin A Clayton
- From the Departments of Pharmacology and Experimental Therapeutics and
| | | | - Grant Yonemoto
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - Lacin Koro
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - Seiko Ikezu
- From the Departments of Pharmacology and Experimental Therapeutics and
| | - Tsuneya Ikezu
- From the Departments of Pharmacology and Experimental Therapeutics and .,Neurology, Boston University School of Medicine, Boston, Massachusetts 02118
| |
Collapse
|
76
|
Mazaheri F, Snaidero N, Kleinberger G, Madore C, Daria A, Werner G, Krasemann S, Capell A, Trümbach D, Wurst W, Brunner B, Bultmann S, Tahirovic S, Kerschensteiner M, Misgeld T, Butovsky O, Haass C. TREM2 deficiency impairs chemotaxis and microglial responses to neuronal injury. EMBO Rep 2017; 18:1186-1198. [PMID: 28483841 DOI: 10.15252/embr.201743922] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/27/2017] [Accepted: 03/31/2017] [Indexed: 12/20/2022] Open
Abstract
Sequence variations in the triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to an increased risk for neurodegenerative disorders such as Alzheimer's disease and frontotemporal lobar degeneration. In the brain, TREM2 is predominantly expressed in microglia. Several disease-associated TREM2 variants result in a loss of function by reducing microglial phagocytosis, impairing lipid sensing, preventing binding of lipoproteins and affecting shielding of amyloid plaques. We here investigate the consequences of TREM2 loss of function on the microglia transcriptome. Among the differentially expressed messenger RNAs in wild-type and Trem2-/- microglia, gene clusters are identified which represent gene functions in chemotaxis, migration and mobility. Functional analyses confirm that loss of TREM2 impairs appropriate microglial responses to injury and signals that normally evoke chemotaxis on multiple levels. In an ex vivo organotypic brain slice assay, absence of TREM2 reduces the distance migrated by microglia. Moreover, migration towards defined chemo-attractants is reduced upon ablation of TREM2 and can be rescued by TREM2 re-expression. In vivo, microglia lacking TREM2 migrate less towards injected apoptotic neurons, and outgrowth of microglial processes towards sites of laser-induced focal CNS damage in the somatosensory cortex is slowed. The apparent lack of chemotactic stimulation upon depletion of TREM2 is consistent with a stable expression profile of genes characterizing the homoeostatic signature of microglia.
Collapse
Affiliation(s)
- Fargol Mazaheri
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany.,Institute for Clinical Neuroimmunology, Biomedical Center (BMC) and University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gernot Kleinberger
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Charlotte Madore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Anna Daria
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Georg Werner
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Susanne Krasemann
- Institute for Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anja Capell
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| | - Dietrich Trümbach
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Developmental Genetics, Technical University Munich-Weihenstephan, Neuherberg, Germany
| | - Bettina Brunner
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Sebastian Bultmann
- Department of Biology and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians-Universität München, Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Martin Kerschensteiner
- Institute for Clinical Neuroimmunology, Biomedical Center (BMC) and University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany .,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany
| |
Collapse
|
77
|
Kober DL, Brett TJ. TREM2-Ligand Interactions in Health and Disease. J Mol Biol 2017; 429:1607-1629. [PMID: 28432014 DOI: 10.1016/j.jmb.2017.04.004] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/06/2017] [Accepted: 04/10/2017] [Indexed: 01/04/2023]
Abstract
The protein triggering receptor expressed on myeloid cells-2 (TREM2) is an immunomodulatory receptor with a central role in myeloid cell activation and survival. In recent years, the importance of TREM2 has been highlighted by the identification of coding variants that increase risk for Alzheimer's disease and other neurodegenerative diseases. Animal studies have further shown the importance of TREM2 in neurodegenerative and other inflammatory disease models including chronic obstructive pulmonary disease, multiple sclerosis, and stroke. A mechanistic understanding of TREM2 function remains elusive, however, due in part to the absence of conclusive information regarding the identity of endogenous TREM2 ligands. While many TREM2 ligands have been proposed, their physiological role and mechanism of engagement remain to be determined. In this review, we highlight the suggested roles of TREM2 in these diseases and the recent advances in our understanding of TREM2 and discuss putative TREM2-ligand interactions and their potential roles in signaling during health and disease. We develop a model based on the TREM2 structure to explain how different TREM2 ligands might interact with the receptor and how disease risk variants may alter ligand interactions. Finally, we propose future experimental directions to establish the role and importance of these different interactions on TREM2 function.
Collapse
Affiliation(s)
- Daniel L Kober
- Molecular Microbiology and Microbial Pathogenesis Program, 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
| | - Tom J Brett
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
78
|
Ulrich JD, Ulland TK, Colonna M, Holtzman DM. Elucidating the Role of TREM2 in Alzheimer’s Disease. Neuron 2017; 94:237-248. [DOI: 10.1016/j.neuron.2017.02.042] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 02/21/2017] [Accepted: 02/22/2017] [Indexed: 12/20/2022]
|
79
|
Jendresen C, Årskog V, Daws MR, Nilsson LNG. The Alzheimer's disease risk factors apolipoprotein E and TREM2 are linked in a receptor signaling pathway. J Neuroinflammation 2017; 14:59. [PMID: 28320424 PMCID: PMC5360024 DOI: 10.1186/s12974-017-0835-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/07/2017] [Indexed: 11/19/2022] Open
Abstract
Background Triggering receptor expressed on myeloid cells 2 (TREM2) and apolipoprotein E (APOE) are genetically linked to Alzheimer’s disease. Here, we investigated whether human ApoE mediates signal transduction through human and murine TREM2 and sought to identify a TREM2-binding domain in human ApoE. Methods To investigate cell signaling through TREM2, a cell line was used which expressed an NFAT-inducible β-galactosidase reporter and human or murine TREM2, fused to CD8 transmembrane and CD3ζ intracellular signaling domains. ELISA-based binding assays were used to determine binding affinities of human ApoE isoforms to human TREM2 and to identify a TREM2-binding domain in ApoE. Results ApoE was found to be an agonist to human TREM2 with EC50 in the low nM range, and to murine TREM2 with reduced potency. In the reporter cells, TREM2 expression was lower than in nontransgenic mouse brain. Human ApoE isoforms ε2, ε3, and ε4 bound to human TREM2 with Kd in the low nM range. The binding was displaced by an ApoE-mimetic peptide (amino acids 130–149). Conclusions An ApoE-mediated dose-dependent signal transduction through TREM2 in reporter cells was demonstrated, and a TREM2-binding region in ApoE was identified. The relevance of an ApoE-TREM2 receptor signaling pathway to Alzheimer’s disease is discussed. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0835-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Charlotte Jendresen
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Postboks 1057 Blindern, 0316, Oslo, Norway
| | - Vibeke Årskog
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Postboks 1057 Blindern, 0316, Oslo, Norway
| | - Michael R Daws
- Division of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Lars N G Nilsson
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Postboks 1057 Blindern, 0316, Oslo, Norway.
| |
Collapse
|
80
|
Zhong L, Chen XF, Wang T, Wang Z, Liao C, Wang Z, Huang R, Wang D, Li X, Wu L, Jia L, Zheng H, Painter M, Atagi Y, Liu CC, Zhang YW, Fryer JD, Xu H, Bu G. Soluble TREM2 induces inflammatory responses and enhances microglial survival. J Exp Med 2017; 214:597-607. [PMID: 28209725 PMCID: PMC5339672 DOI: 10.1084/jem.20160844] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 10/25/2016] [Accepted: 01/24/2017] [Indexed: 12/31/2022] Open
Abstract
Zhong et al. describe two novel roles for soluble TREM2 (sTREM2) in regulation of proinflammatory responses and prevention of cellular apoptosis in microglia. Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune receptor expressed in microglia in the brain. A soluble form of TREM2 (sTREM2) derived from proteolytic cleavage of the cell surface receptor is increased in the preclinical stages of AD and positively correlates with the amounts of total and phosphorylated tau in the cerebrospinal fluid. However, the physiological and pathological functions of sTREM2 remain unknown. Here, we show that sTREM2 promotes microglial survival in a PI3K/Akt-dependent manner and stimulates the production of inflammatory cytokines depending on NF-κB. Variants of sTREM2 carrying AD risk-associated mutations were less potent in both suppressing apoptosis and triggering inflammatory responses. Importantly, sTREM2 delivered to the hippocampi of both wild-type and Trem2-knockout mice elevated the expression of inflammatory cytokines and induced morphological changes of microglia. Collectively, these data indicate that sTREM2 triggers microglial activation inducing inflammatory responses and promoting survival. This study has implications for the pathogenesis of AD and provides insights into targeting sTREM2 pathway for AD therapy.
Collapse
Affiliation(s)
- Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China .,Shenzhen Research Institute of Xiamen University, Shenzhen 518063, China
| | - Tingting Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Zhe Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Chunyan Liao
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Zongqi Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Ruizhi Huang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Daxin Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Xinxiu Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Linbei Wu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Lin Jia
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - Meghan Painter
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224
| | - Yuka Atagi
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224
| | - Chia-Chen Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China
| | - John D Fryer
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224.,Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, FL 32224
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China.,Neuroscience and Aging Research Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA 92037
| | - Guojun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen 361102, China .,Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224.,Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, FL 32224
| |
Collapse
|
81
|
Bonham LW, Sirkis DW, Fan J, Aparicio RE, Tse M, Ramos EM, Wang Q, Coppola G, Rosen HJ, Miller BL, Yokoyama JS. Identification of a rare coding variant in TREM2 in a Chinese individual with Alzheimer's disease. Neurocase 2017; 23:65-69. [PMID: 28376694 PMCID: PMC5639900 DOI: 10.1080/13554794.2017.1294182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Rare variation in the TREM2 gene is associated with a broad spectrum of neurodegenerative disorders including Alzheimer's disease (AD). TREM2 encodes a receptor expressed in microglia which is thought to influence neurodegeneration by sensing damage signals and regulating neuroinflammation. Many of the variants reported to be associated with AD, including the rare R47H variant, were discovered in populations of European ancestry and have not replicated in diverse populations from other genetic backgrounds. We utilized a cohort of elderly Chinese individuals diagnosed as cognitively normal, or with mild cognitive impairment or AD to identify a rare variant, A192T, present in a single patient diagnosed with AD. We characterized this variant using biochemical cell surface expression assays and found that it significantly altered cell surface expression of the TREM2 protein. Together these data provide evidence that the A192T variant in TREM2 could contribute risk for AD. This study underscores the increasingly recognized role of immune-related processes in AD and highlights the importance of including diverse populations in research to identify genetic variation that contributes risk for AD and other neurodegenerative disorders.
Collapse
Affiliation(s)
- Luke W Bonham
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA
| | - Daniel W Sirkis
- b Department of Molecular and Cell Biology, Howard Hughes Medical Institute , University of California, Berkeley , Berkeley , CA , USA
| | - Jia Fan
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA.,c Department of Neurology , Second Hospital of Jilin University , Changchun , China
| | - Renan E Aparicio
- b Department of Molecular and Cell Biology, Howard Hughes Medical Institute , University of California, Berkeley , Berkeley , CA , USA
| | - Marian Tse
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA
| | - Eliana Marisa Ramos
- d Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior , The David Geffen School of Medicine at University of California Los Angeles , Los Angeles , CA , USA
| | - Qing Wang
- d Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior , The David Geffen School of Medicine at University of California Los Angeles , Los Angeles , CA , USA
| | - Giovanni Coppola
- d Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior , The David Geffen School of Medicine at University of California Los Angeles , Los Angeles , CA , USA
| | - Howard J Rosen
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA
| | - Bruce L Miller
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA
| | - Jennifer S Yokoyama
- a Memory and Aging Center, Department of Neurology , University of California, San Francisco , San Francisco , CA , USA
| |
Collapse
|
82
|
A novel mutation in TREM2 gene causing Nasu-Hakola disease and review of the literature. Neurobiol Aging 2017; 53:194.e13-194.e22. [PMID: 28214109 DOI: 10.1016/j.neurobiolaging.2017.01.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 01/11/2017] [Indexed: 11/20/2022]
Abstract
Nasu-hakola disease (NHD) is a rare disease characterized by bone cysts and fractures, frontal lobe syndrome, and progressive presenile dementia. NHD may be the prototype of primary microglial disorders of the CNS or, as they have been coined, "microgliopathies". Mutations in TREM2 and TYROBP genes are known to cause NHD. Interestingly, recent evidence-associated rare genetic variants of TREM2 gene with increased risk of Alzheimer's disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Parkinson's disease. Here, we report a 33-year-old Greek female with phenotype suggestive of NHD. Full gene sequencing of the TREM2 and TYROBP genes revealed a novel mutation in exon 2 of TREM2 gene, namely c.244G>T (p.W50C) and heterozygosity in the parents and her brother. This report extends the range of TREM2 mutations that cause NHD phenotype. In addition, we provide a comprehensive review of all reported in the literature TREM2 gene mutations and the respective wide spectrum of clinical manifestations that highlights the importance of considering TREM2 gene mutations in a variety of neurodegenerative phenotypes.
Collapse
|
83
|
Park JS, Ji IJ, Kim DH, An HJ, Yoon SY. The Alzheimer's Disease-Associated R47H Variant of TREM2 Has an Altered Glycosylation Pattern and Protein Stability. Front Neurosci 2017; 10:618. [PMID: 28149270 PMCID: PMC5241589 DOI: 10.3389/fnins.2016.00618] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/26/2016] [Indexed: 11/13/2022] Open
Abstract
The R47H coding variant of the triggering receptor expressed on myeloid cells-2 (TREM2) increases the risk of Alzheimer's disease (AD) similar to apolipoprotein E4. TREM2 R47H has recently been shown to have impaired binding to damage-associated lipid or apolipoprotein ligands. However, it is not known how this R47H variant affects the biochemical characteristics of TREM2 and alters the pathogenesis of AD. We previously reported that TREM2-R47H has a slightly different glycosylation pattern from wild-type. A more detailed characterization in our present study confirms that TREM2 R47H has an altered glycosylation pattern and reduced stability. TREM2 R47H shows different glycosylation profiles from analysis using monensin or kifunensine treatment which were confirmed by mass spectrometry. The solubility of TREM2 R47H and its cleaved products such as intracellular domain (ICD) is also decreased, increasing its proteasomal and lysosomal degradation. The different biochemical characteristics of TREM2 R47H, including glycosylation, solubility and processing, may offer insights into a future therapeutic strategy for AD.
Collapse
Affiliation(s)
- Ji-Seon Park
- Alzheimer's Disease Experts Lab, Asan Medical Center, University of Ulsan College of MedicineSeoul, South Korea; Department of Brain Science, University of Ulsan College of MedicineSeoul, South Korea; Bio-Medical Institute of Technology, University of Ulsan College of MedicineSeoul, South Korea; Cell Dysfunction Research Center, University of Ulsan College of MedicineSeoul, South Korea
| | - In Jung Ji
- Asia Glycomics Reference SiteDaejeon, South Korea; Graduate School of Analytical Science and Technology, Chungnam National UniversityDaejeon, South Korea
| | - Dong-Hou Kim
- Alzheimer's Disease Experts Lab, Asan Medical Center, University of Ulsan College of MedicineSeoul, South Korea; Department of Brain Science, University of Ulsan College of MedicineSeoul, South Korea; Bio-Medical Institute of Technology, University of Ulsan College of MedicineSeoul, South Korea; Cell Dysfunction Research Center, University of Ulsan College of MedicineSeoul, South Korea
| | - Hyun Joo An
- Asia Glycomics Reference SiteDaejeon, South Korea; Graduate School of Analytical Science and Technology, Chungnam National UniversityDaejeon, South Korea
| | - Seung-Yong Yoon
- Alzheimer's Disease Experts Lab, Asan Medical Center, University of Ulsan College of MedicineSeoul, South Korea; Department of Brain Science, University of Ulsan College of MedicineSeoul, South Korea; Bio-Medical Institute of Technology, University of Ulsan College of MedicineSeoul, South Korea; Cell Dysfunction Research Center, University of Ulsan College of MedicineSeoul, South Korea
| |
Collapse
|
84
|
The APOE ε4 genotype modulates CSF YKL-40 levels and their structural brain correlates in the continuum of Alzheimer's disease but not those of sTREM2. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2016; 6:50-59. [PMID: 28149943 PMCID: PMC5266482 DOI: 10.1016/j.dadm.2016.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Among other metabolic functions, the apolipoprotein E (APOE) plays a crucial role in neuroinflammation. We aimed at assessing whether APOE ε4 modulates levels of glial cerebrospinal fluid (CSF) biomarkers and their structural cerebral correlates along the continuum of Alzheimer's disease (AD). METHODS Brain magnetic resonance imaging (MRI) scans were acquired in 110 participants (49 control; 19 preclinical; 27 mild cognitive impairment [MCI] due to AD; 15 mild AD dementia) and CSF concentrations of YKL-40 and sTREM2 were determined. Differences in CSF biomarker concentrations and interactions in their association with gray-matter volume according to APOE ε4 status were sought after. RESULTS Preclinical and MCI carriers showed higher YKL-40 levels. There was a significant interaction in the association between YKL-40 levels and gray-matter volume according to ε4 status. No similar effects could be detected for sTREM2 levels. DISCUSSION Our findings are indicative of an increased astroglial activation in APOE ε4 carriers while both groups displayed similar levels of CSF AD core biomarkers.
Collapse
|
85
|
Rodriguez-Callejas JD, Fuchs E, Perez-Cruz C. Evidence of Tau Hyperphosphorylation and Dystrophic Microglia in the Common Marmoset. Front Aging Neurosci 2016; 8:315. [PMID: 28066237 PMCID: PMC5177639 DOI: 10.3389/fnagi.2016.00315] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/08/2016] [Indexed: 01/22/2023] Open
Abstract
Common marmosets (Callithrix jacchus) have recently gained popularity in biomedical research as models of aging research. Basically, they confer advantages from other non-human primates due to their shorter lifespan with onset of appearance of aging at 8 years. Old marmosets present some markers linked to neurodegeneration in the brain such as amyloid beta (Aβ)1-42 and Aβ1-40. However, there are no studies exploring other cellular markers associated with neurodegenerative diseases in this non-human primate. Using immunohistochemistry, we analyzed brains of male adolescent, adult, old, and aged marmosets. We observed accumulation of Aβ1-40 and Aβ1-42 in the cortex of aged subjects. Tau hyperphosphorylation was already detected in the brain of adolescent animals and increased with aging in a more fibrillary form. Microglia activation was also observed in the aging process, while a dystrophic phenotype accumulates in aged subjects. Interestingly, dystrophic microglia contained hyperphosphorylated tau, but active microglia did not. These results support previous findings regarding microglia dysfunctionality in aging and neurodegenerative diseases as Alzheimer's disease. Further studies should explore the functional consequences of these findings to position this non-human primate as animal model of aging and neurodegeneration.
Collapse
Affiliation(s)
- Juan D Rodriguez-Callejas
- Laboratory of Neuroplasticity and Neurodegeneration, Department of Pharmacology, Center for Research and Advanced Studies (CINVESTAV) Mexico City, Mexico
| | - Eberhard Fuchs
- Clinical Neurobiology Laboratory, German Primate Center - Leibniz Institute for Primate Research, Göttingen Germany
| | - Claudia Perez-Cruz
- Laboratory of Neuroplasticity and Neurodegeneration, Department of Pharmacology, Center for Research and Advanced Studies (CINVESTAV) Mexico City, Mexico
| |
Collapse
|
86
|
Cheng J, Guo X, Zhang T, Zhong L, Bu G, Chen X. TREMs in Alzheimer's disease: Genetic and clinical investigations. Clin Chim Acta 2016; 463:88-95. [PMID: 27769848 DOI: 10.1016/j.cca.2016.10.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/16/2016] [Accepted: 10/17/2016] [Indexed: 02/07/2023]
Abstract
Triggering receptor expressed on myeloid cells (TREMs) receptors constitute a family modulators in human innate immunity system that encode by a gene cluster. Rare variants in TREM2 were reported to be associated with significant Alzheimer's disease (AD) risk. However, inconsistent results were also reported in some studies of Non-European descents. Recently, the other TREM family members are also considered to involve in AD and cerebrospinal fluid (CSF) soluble form of TREM2 (sTREM2) levels has also been associated with respond to progression of disease. In this review, we converged the data of genetic and clinical investigations to identify the clearer role of TREMs in AD. Here, comprehensively analyze of multidisciplinary fields highlights the contribution of TREMs locus to AD development.
Collapse
Affiliation(s)
- Jia Cheng
- Zhongshan Hospital, Xiamen University, Xiamen, Fujian, China.
| | - XiaoFeng Guo
- Zhongshan Hospital, Xiamen University, Xiamen, Fujian, China
| | - Tian Zhang
- Zhongshan Hospital, Xiamen University, Xiamen, Fujian, China
| | - Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, Fujian, China
| | - GuoJun Bu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, Fujian, China; Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - XiaoFen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Medical College, Xiamen University, Xiamen, Fujian, China
| |
Collapse
|
87
|
Sirkis DW, Bonham LW, Aparicio RE, Geier EG, Ramos EM, Wang Q, Karydas A, Miller ZA, Miller BL, Coppola G, Yokoyama JS. Rare TREM2 variants associated with Alzheimer's disease display reduced cell surface expression. Acta Neuropathol Commun 2016; 4:98. [PMID: 27589997 PMCID: PMC5010724 DOI: 10.1186/s40478-016-0367-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/17/2016] [Indexed: 01/06/2023] Open
Abstract
Rare variation in TREM2 has been associated with greater risk for Alzheimer’s disease (AD). TREM2 encodes a cell surface receptor expressed on microglia and related cells, and the R47H variant associated with AD appears to affect the ability of TREM2 to bind extracellular ligands. In addition, other rare TREM2 mutations causing early-onset neurodegeneration are thought to impair cell surface expression. Using a sequence kernel association (SKAT) analysis in two independent AD cohorts, we found significant enrichment of rare TREM2 variants not previously characterized at the protein level. Heterologous expression of the identified variants showed that novel variants S31F and R47C displayed significantly reduced cell surface expression. In addition, we identified rare variant R136Q in a patient with language-predominant AD that also showed impaired surface expression. The results suggest rare TREM2 variants enriched in AD may be associated with altered TREM2 function and that AD risk may be conferred, in part, from altered TREM2 surface expression.
Collapse
|
88
|
Xiang X, Werner G, Bohrmann B, Liesz A, Mazaheri F, Capell A, Feederle R, Knuesel I, Kleinberger G, Haass C. TREM2 deficiency reduces the efficacy of immunotherapeutic amyloid clearance. EMBO Mol Med 2016; 8:992-1004. [PMID: 27402340 PMCID: PMC5009806 DOI: 10.15252/emmm.201606370] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Immunotherapeutic approaches are currently the most advanced treatments for Alzheimer's disease (AD). Antibodies against amyloid β-peptide (Aβ) bind to amyloid plaques and induce their clearance by microglia via Fc receptor-mediated phagocytosis. Dysfunctions of microglia may play a pivotal role in AD pathogenesis and could result in reduced efficacy of antibody-mediated Aβ clearance. Recently, heterozygous mutations in the triggering receptor expressed on myeloid cells 2 (TREM2), a microglial gene involved in phagocytosis, were genetically linked to late onset AD Loss of TREM2 reduces the ability of microglia to engulf Aβ. We have now investigated whether loss of TREM2 affects the efficacy of immunotherapeutic approaches. We show that anti-Aβ antibodies stimulate Aβ uptake and amyloid plaque clearance in a dose-dependent manner in the presence or absence of TREM2. However, TREM2-deficient N9 microglial cell lines, macrophages as well as primary microglia showed significantly reduced uptake of antibody-bound Aβ and as a consequence reduced clearance of amyloid plaques. Titration experiments revealed that reduced efficacy of amyloid plaque clearance by Trem2 knockout cells can be compensated by elevating the concentration of therapeutic antibodies.
Collapse
Affiliation(s)
- Xianyuan Xiang
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany Graduate School of Systemic Neuroscience, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Georg Werner
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Bernd Bohrmann
- Roche Pharmaceutical Research and Early Development NORD Discovery & Translational Area, Roche Innovation Center Basel, Basel, Switzerland
| | - Arthur Liesz
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Fargol Mazaheri
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Anja Capell
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Regina Feederle
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany Helmholtz Center Munich, German Research Center for Environmental Health, Institute for Diabetes and Obesity Core Facility Monoclonal Antibody Development, Munich, Germany
| | - Irene Knuesel
- Roche Pharmaceutical Research and Early Development NORD Discovery & Translational Area, Roche Innovation Center Basel, Basel, Switzerland
| | - Gernot Kleinberger
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- Biomedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| |
Collapse
|
89
|
Gispert JD, Suárez-Calvet M, Monté GC, Tucholka A, Falcon C, Rojas S, Rami L, Sánchez-Valle R, Lladó A, Kleinberger G, Haass C, Molinuevo JL. Cerebrospinal fluid sTREM2 levels are associated with gray matter volume increases and reduced diffusivity in early Alzheimer's disease. Alzheimers Dement 2016; 12:1259-1272. [PMID: 27423963 DOI: 10.1016/j.jalz.2016.06.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/28/2016] [Accepted: 06/09/2016] [Indexed: 01/12/2023]
Abstract
INTRODUCTION TREM2 is involved in the regulation of inflammatory response and phagocytosis. A soluble fragment (sTREM2) is often found abnormally increased in cerebrospinal fluid (CSF) in Alzheimer's disease (AD). METHODS One hundred fourteen participants (45 control, 19 preclinical, 27 mild cognitive impairment [MCI], and 23 AD) underwent CSF sTREM2 determination and magnetic resonance imaging (MRI). We studied the association between CSF sTREM2, gray matter volume, and water motion diffusivity and anisotropy across groups. RESULTS In MCI patients, a positive correlation between CSF sTREM2 and gray matter volume was found in the bilateral inferior and middle temporal cortices, precuneus, the supramarginal, and angular gyri, after controlling by age, sex, and p-tau. A negative correlation with mean diffusivity was detected in overlapping regions, among others. DISCUSSION In early AD, augmented CSF sTREM2 levels correspond with cerebral MRI features typical of brain swelling, supporting a role for TREM2 in the regulation of the neuroinflammatory response to early neurodegeneration.
Collapse
Affiliation(s)
- Juan Domingo Gispert
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain; Pompeu Fabra University, Barcelona, Spain
| | - Marc Suárez-Calvet
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Gemma C Monté
- Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Alan Tucholka
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
| | - Carles Falcon
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain; Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Santiago Rojas
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain; Unit of human Anatomy and Embryology, Department of Morphological Sciences, Faculty of Medicine, Autonomous University of Barcelona, Cerdanyola del Vallès, Spain
| | - Lorena Rami
- Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Raquel Sánchez-Valle
- Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Lladó
- Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Gernot Kleinberger
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - José Luis Molinuevo
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| |
Collapse
|
90
|
Woollacott IOC, Rohrer JD. The clinical spectrum of sporadic and familial forms of frontotemporal dementia. J Neurochem 2016; 138 Suppl 1:6-31. [PMID: 27144467 DOI: 10.1111/jnc.13654] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/10/2016] [Accepted: 04/27/2016] [Indexed: 12/11/2022]
Abstract
The term frontotemporal dementia (FTD) describes a clinically, genetically and pathologically diverse group of neurodegenerative disorders. Symptoms of FTD can present in individuals in their 20s through to their 90s, but the mean age at onset is in the sixth decade. The most common presentation is with a change in personality and impaired social conduct (behavioural variant FTD). Less frequently patients present with language problems (primary progressive aphasia). Both of these groups of patients can develop motor features consistent with either motor neuron disease (usually the amyotrophic lateral sclerosis variant) or parkinsonism (most commonly a progressive supranuclear palsy or corticobasal syndrome). In about a third of cases FTD is familial, with mutations in the progranulin, microtubule-associated protein tau and chromosome 9 open reading frame 72 genes being the major causes. Mutations in a number of other genes including TANK-binding kinase 1 are rare causes of familial FTD. This review aims to clarify the often confusing terminology of FTD, and outline the various clinical features and diagnostic criteria of sporadic and familial FTD syndromes. It will also discuss the current major challenges in FTD research and clinical practice, and potential areas for future research. This review clarifies the terminology of frontotemporal dementia (FTD) and summarizes the various clinical features and most recent diagnostic criteria of sporadic and familial FTD syndromes. It also discusses the current major challenges in FTD research and clinical practice, and highlights potential areas for future research.
Collapse
Affiliation(s)
- Ione O C Woollacott
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| | - Jonathan D Rohrer
- Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
| |
Collapse
|
91
|
Xiong L, Xia WF, Tang FL, Pan JX, Mei L, Xiong WC. Retromer in Osteoblasts Interacts With Protein Phosphatase 1 Regulator Subunit 14C, Terminates Parathyroid Hormone's Signaling, and Promotes Its Catabolic Response. EBioMedicine 2016; 9:45-60. [PMID: 27333042 PMCID: PMC4972523 DOI: 10.1016/j.ebiom.2016.05.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 05/11/2016] [Accepted: 05/24/2016] [Indexed: 12/02/2022] Open
Abstract
Parathyroid hormone (PTH) plays critical, but distinct, roles in bone remodeling, including bone formation (anabolic response) and resorption (catabolic response). Although its signaling and function have been extensively investigated, it just began to be understood how distinct functions are induced by PTH activating a common receptor, the PTH type 1 receptor (PTH1R), and how PTH1R signaling is terminated. Here, we provide evidence for vacuolar protein sorting 35 (VPS35), a major component of retromer, in regulating PTH1R trafficking, turning off PTH signaling, and promoting its catabolic function. VPS35 is expressed in osteoblast (OB)-lineage cells. VPS35-deficiency in OBs impaired PTH(1–34)-promoted PTH1R translocation to the trans-Golgi network, enhanced PTH(1–34)-driven signaling, and reduced PTH(1–34)'s catabolic response in culture and in mice. Further mechanical studies revealed that VPS35 interacts with not only PTH1R, but also protein phosphatase 1 regulatory subunit 14C (PPP1R14C), an inhibitory subunit of PP1 phosphatase. PPP1R14C also interacts with PTH1R, which is necessary for the increased endosomal PTH1R signaling and decreased PTH(1–34)'s catabolic response in VPS35-deficient OB-lineage cells. Taken together, these results suggest that VPS35 deregulates PTH1R-signaling likely by its interaction with PTH1R and PPP1R14C. This event is critical for the control of PTH(1–34)-signaling dynamics, which may underlie PTH-induced catabolic response and adequate bone remodeling. VPS35 terminates PTH(1-34)-induced cell surface and endosomal signalings Osteoblastic VPS35 promotes PTH(1-34)-driven catabolic response VPS35 interacts with PPP1R14C PPP1R14C also interacts with PTH1R and promotes PTH(1-34)-induced endosomal signaling PPP1R14C is necessary for the increased endosomal PTH1R signaling and decreased PTH(1-34)’s catabolic response in VPS35-deficient OB-lineage cells
Collapse
Affiliation(s)
- Lei Xiong
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States
| | - Wen-Fang Xia
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States; Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Fu-Lei Tang
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States
| | - Jin-Xiu Pan
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States
| | - Lin Mei
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States
| | - Wen-Cheng Xiong
- Department of Neuroscience & Regenerative Medicine, Department of Neurology, Medical College of Georgia, Augusta, GA 30912, United States; Charlie Norwood VA Medical Center, Augusta, GA 30912, United States.
| |
Collapse
|
92
|
Suárez-Calvet M, Kleinberger G, Araque Caballero MÁ, Brendel M, Rominger A, Alcolea D, Fortea J, Lleó A, Blesa R, Gispert JD, Sánchez-Valle R, Antonell A, Rami L, Molinuevo JL, Brosseron F, Traschütz A, Heneka MT, Struyfs H, Engelborghs S, Sleegers K, Van Broeckhoven C, Zetterberg H, Nellgård B, Blennow K, Crispin A, Ewers M, Haass C. sTREM2 cerebrospinal fluid levels are a potential biomarker for microglia activity in early-stage Alzheimer's disease and associate with neuronal injury markers. EMBO Mol Med 2016; 8:466-76. [PMID: 26941262 PMCID: PMC5120370 DOI: 10.15252/emmm.201506123] [Citation(s) in RCA: 347] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
TREM2 is an innate immune receptor expressed on the surface of microglia. Loss‐of‐function mutations of TREM2 are associated with increased risk of Alzheimer's disease (AD). TREM2 is a type‐1 protein with an ectodomain that is proteolytically cleaved and released into the extracellular space as a soluble variant (sTREM2), which can be measured in the cerebrospinal fluid (CSF). In this cross‐sectional multicenter study, we investigated whether CSF levels of sTREM2 are changed during the clinical course of AD, and in cognitively normal individuals with suspected non‐AD pathology (SNAP). CSF sTREM2 levels were higher in mild cognitive impairment due to AD than in all other AD groups and controls. SNAP individuals also had significantly increased CSF sTREM2 compared to controls. Moreover, increased CSF sTREM2 levels were associated with higher CSF total tau and phospho‐tau181P, which are markers of neuronal degeneration and tau pathology. Our data demonstrate that CSF sTREM2 levels are increased in the early symptomatic phase of AD, probably reflecting a corresponding change of the microglia activation status in response to neuronal degeneration.
Collapse
Affiliation(s)
- Marc Suárez-Calvet
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany
| | - Gernot Kleinberger
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Miguel Ángel Araque Caballero
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Axel Rominger
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Department of Nuclear Medicine, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Daniel Alcolea
- Department of Neurology, Institut d'Investigacions Biomèdiques Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona, Barcelona, Spain Center for Networked Biomedical Research for Neurodegenerative Diseases, CIBERNED, Madrid, Spain
| | - Juan Fortea
- Department of Neurology, Institut d'Investigacions Biomèdiques Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona, Barcelona, Spain Center for Networked Biomedical Research for Neurodegenerative Diseases, CIBERNED, Madrid, Spain
| | - Alberto Lleó
- Department of Neurology, Institut d'Investigacions Biomèdiques Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona, Barcelona, Spain Center for Networked Biomedical Research for Neurodegenerative Diseases, CIBERNED, Madrid, Spain
| | - Rafael Blesa
- Department of Neurology, Institut d'Investigacions Biomèdiques Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona, Barcelona, Spain Center for Networked Biomedical Research for Neurodegenerative Diseases, CIBERNED, Madrid, Spain
| | - Juan Domingo Gispert
- Clinical and Neuroimaging Departments, Barcelona Beta Brain Research Center Pasqual Maragall Foundation, Barcelona, Spain Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain
| | - Raquel Sánchez-Valle
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic i Universitari, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Anna Antonell
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic i Universitari, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Lorena Rami
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic i Universitari, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - José L Molinuevo
- Clinical and Neuroimaging Departments, Barcelona Beta Brain Research Center Pasqual Maragall Foundation, Barcelona, Spain Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, ICN Hospital Clinic i Universitari, Barcelona, Spain Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | | | | | - Michael T Heneka
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany Neurology Department, Universitätsklinikum Bonn, Bonn, Germany
| | - Hanne Struyfs
- Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium
| | - Sebastiaan Engelborghs
- Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium
| | - Kristel Sleegers
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Henrik Zetterberg
- Clinical Neurochemistry Lab, Institute of Neuroscience and Physiology The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden Reta Lila Weston Laboratories and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Bengt Nellgård
- Department of Anaesthesiology and Intensive Care, Institute of Clinical Sciences Sahlgrenska Academy Gothenburg University, Gothenburg, Sweden
| | - Kaj Blennow
- Clinical Neurochemistry Lab, Institute of Neuroscience and Physiology The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Alexander Crispin
- Institute of Medical Informatics, Biometry, and Epidemiology, Munich, Germany
| | - Michael Ewers
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Christian Haass
- BioMedical Center (BMC), Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
93
|
Krasniak CS, Ahmad ST. The role of CHMP2B Intron5 in autophagy and frontotemporal dementia. Brain Res 2016; 1649:151-157. [PMID: 26972529 DOI: 10.1016/j.brainres.2016.02.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 02/05/2016] [Accepted: 02/10/2016] [Indexed: 12/12/2022]
Abstract
Charged multivesicular body protein 2B (CHMP2B) - a component of the endosomal complex required for transport-III (ESCRT-III) - is responsible for the vital membrane deformation functions in autophagy and endolysosomal trafficking. A dominant mutation in CHMP2B (CHMP2BIntron5) is associated with a subset of heritable frontotemporal dementia - frontotemporal dementia linked to chromosome 3 (FTD-3). ESCRT-III recruits Vps4, an AAA-ATPase that abscises the membrane during various cellular processes including autophagy and intraluminal vesicle formation. CHMP2BIntron5 results in a C-terminus truncation removing an important Vps4 binding site as well as eliminating the normal autoinhibitory resting state of CHMP2B. CHMP2B is expressed in most cell types but seems to be especially vital for proper neuronal function. CHMP2BIntron5-mediated phenotypes include misregulation of transmembrane receptors, accumulation of multilamellar structures, abnormal lysosomal morphology, down regulation of a brain-specific micro RNA (miRNA-124), abnormal dendritic spine morphology, decrease in dendritic arborization, and cell death. Currently, transgenic-fly,-mouse, and -human cell lines are being used to better understand the diverse phenotypes and develop therapeutic approaches for the CHMP2BIntron5-induced FTD-3. This article is part of a Special Issue entitled SI:Autophagy.
Collapse
Affiliation(s)
| | - S Tariq Ahmad
- Department of Biology, Colby College, 5720 Mayflower Hill, Waterville, ME 04901, USA.
| |
Collapse
|
94
|
Colonna M, Wang Y. TREM2 variants: new keys to decipher Alzheimer disease pathogenesis. Nat Rev Neurosci 2016; 17:201-7. [PMID: 26911435 DOI: 10.1038/nrn.2016.7] [Citation(s) in RCA: 277] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genome-wide association studies have identified rare variants of the gene that encodes triggering receptor expressed on myeloid cells 2 (TREM2) - an immune receptor that is found in brain microglia - as risk factors for non-familial Alzheimer disease (AD). Furthermore, animal studies have indicated that microglia have an important role in the brain response to amyloid-β (Aβ) plaques and that TREM2 variants may have an impact on such a function. We discuss how TREM2 may control the microglial response to Aβ and its impact on microglial senescence, as well as the interaction of TREM2 with other molecules that are encoded by gene variants associated with AD and the hypothetical consequences of the cleavage of TREM2 from the cell surface.
Collapse
Affiliation(s)
- Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - Yaming Wang
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana 46285, USA
| |
Collapse
|
95
|
Onos KD, Sukoff Rizzo SJ, Howell GR, Sasner M. Toward more predictive genetic mouse models of Alzheimer's disease. Brain Res Bull 2015; 122:1-11. [PMID: 26708939 DOI: 10.1016/j.brainresbull.2015.12.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/09/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
Genetic mouse models for Alzheimer's disease (AD) have been widely used to understand aspects of the biology of the disease, but have had limited success in translating these findings to the clinic. In this review, we discuss the benefits and limitations of existing genetic models and recent advances in technologies (including high throughput sequencing and genome editing) that promise more predictive models. We summarize widely used biomarkers and behavioral tests for mouse models of AD and highlight best practices that will maximize translatability of preclinical findings.
Collapse
Affiliation(s)
| | | | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, United States; Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, United States.
| | | |
Collapse
|
96
|
Tan T, Song Z, Yuan L, Xiong W, Deng X, Ni B, Chen Y, Deng H. Genetic analysis of TREM2 variants in Chinese Han patients with sporadic Parkinson's disease. Neurosci Lett 2015; 612:189-192. [PMID: 26704436 DOI: 10.1016/j.neulet.2015.12.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/11/2015] [Accepted: 12/12/2015] [Indexed: 11/19/2022]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease and is characterized by the degeneration of dopaminergic neurons in substantia nigra. Recently, rs75932628 (p.R47H) of the triggering receptor expressed on myeloid cells 2 gene (TREM2) was identified to be associated with PD in American, Spanish, Irish, and Polish population. To explore whether TREM2 variants are related to susceptibility of sporadic PD in Chinese Han population, we designed a case-control comparison study and studied two variants rs75932628 (p.R47H) and rs2234253 (p.T96K) of the TREM2 gene in 512 Chinese Han patients with sporadic PD and 512 age, gender and ethnicity matched normal controls from Mainland China. No variant for either rs75932628 or rs2234253 was found in both PD and control cohorts. Our data suggest that neither variant rs75932628 nor rs2234253 be a major susceptibility factor of sporadic PD in Chinese Han population from Mainland China.
Collapse
Affiliation(s)
- Ting Tan
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Lamei Yuan
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Wei Xiong
- Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xiong Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Bin Ni
- Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, China
| | - Yong Chen
- Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, China.
| | - Hao Deng
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China; Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China.
| |
Collapse
|
97
|
Radford RA, Morsch M, Rayner SL, Cole NJ, Pountney DL, Chung RS. The established and emerging roles of astrocytes and microglia in amyotrophic lateral sclerosis and frontotemporal dementia. Front Cell Neurosci 2015; 9:414. [PMID: 26578880 PMCID: PMC4621294 DOI: 10.3389/fncel.2015.00414] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/01/2015] [Indexed: 12/22/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two progressive, fatal neurodegenerative syndromes with considerable clinical, genetic and pathological overlap. Clinical symptoms of FTD can be seen in ALS patients and vice versa. Recent genetic discoveries conclusively link the two diseases, and several common molecular players have been identified (TDP-43, FUS, C9ORF72). The definitive etiologies of ALS and FTD are currently unknown and both disorders lack a cure. Glia, specifically astrocytes and microglia are heavily implicated in the onset and progression of neurodegeneration witnessed in ALS and FTD. In this review, we summarize the current understanding of the role of microglia and astrocytes involved in ALS and FTD, highlighting their recent implications in neuroinflammation, alterations in waste clearance involving phagocytosis and the newly described glymphatic system, and vascular abnormalities. Elucidating the precise mechanisms of how astrocytes and microglia are involved in ALS and FTD will be crucial in characterizing these two disorders and may represent more effective interventions for disease progression and treatment options in the future.
Collapse
Affiliation(s)
- Rowan A Radford
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| | - Marco Morsch
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| | - Stephanie L Rayner
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| | - Nicholas J Cole
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| | - Dean L Pountney
- Menzies Health Institute Queensland, Griffith University Gold Coast, QLD, Australia
| | - Roger S Chung
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| |
Collapse
|
98
|
Roussos P, Katsel P, Fam P, Tan W, Purohit DP, Haroutunian V. The triggering receptor expressed on myeloid cells 2 (TREM2) is associated with enhanced inflammation, neuropathological lesions and increased risk for Alzheimer's dementia. Alzheimers Dement 2015; 11:1163-70. [PMID: 25499537 PMCID: PMC4461564 DOI: 10.1016/j.jalz.2014.10.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/25/2014] [Accepted: 10/27/2014] [Indexed: 12/31/2022]
Abstract
INTRODUCTION The objective of this study was to elucidate the relationship between the triggering receptor expressed on myeloid cells 2 (TREM2) risk variant, neuropathological lesions, alterations in gene and protein expression, and the severity of neuroinflammation. METHODS The genetic association study of the R47 H TREM2 variant with Alzheimer's disease (AD), neuropathology, and changes in TREM2 and TYRO protein tyrosine kinase-binding protein (TYROBP) gene and protein expression, and neuroinflammatory markers. RESULTS The TREM2 variant is associated with: (i) AD (odds ratio: 4.76; P = .014); (ii) increased density of amyloid plaques and neurofibrillary tangles in multiple brain regions; (iii) increased TREM2 (P = .041) and TYROBP (P = .006) gene expression; (iv) decreased TREM2 protein levels (P = .016); and (v) upregulation of proinflammatory cytokines (regulated on activation, normal T cell expressed and secreted [RANTES] and interferon [IFN] gamma) (P = .003) and nominal downregulation of protective markers (α2-macroglobulin, interleukin 4 or IL-4, and ApoA1) (P = .018). DISCUSSION These findings link the TREM2 missense mutation with specific molecular abnormalities and increases in neuropathological lesions in the human brain.
Collapse
Affiliation(s)
- Panos Roussos
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Genetics and Genomic Science and Institute for Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA
| | - Pavel Katsel
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Peter Fam
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Weilun Tan
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Dushyant P Purohit
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vahram Haroutunian
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
99
|
Atagi Y, Liu CC, Painter MM, Chen XF, Verbeeck C, Zheng H, Li X, Rademakers R, Kang SS, Xu H, Younkin S, Das P, Fryer JD, Bu G. Apolipoprotein E Is a Ligand for Triggering Receptor Expressed on Myeloid Cells 2 (TREM2). J Biol Chem 2015; 290:26043-50. [PMID: 26374899 DOI: 10.1074/jbc.m115.679043] [Citation(s) in RCA: 369] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/06/2022] Open
Abstract
Several heterozygous missense mutations in the triggering receptor expressed on myeloid cells 2 (TREM2) have recently been linked to risk for a number of neurological disorders including Alzheimer disease (AD), Parkinson disease, and frontotemporal dementia. These discoveries have re-ignited interest in the role of neuroinflammation in the pathogenesis of neurodegenerative diseases. TREM2 is highly expressed in microglia, the resident immune cells of the central nervous system. Along with its adaptor protein, DAP12, TREM2 regulates inflammatory cytokine release and phagocytosis of apoptotic neurons. Here, we report apolipoprotein E (apoE) as a novel ligand for TREM2. Using a biochemical assay, we demonstrated high-affinity binding of apoE to human TREM2. The functional significance of this binding was highlighted by increased phagocytosis of apoE-bound apoptotic N2a cells by primary microglia in a manner that depends on TREM2 expression. Moreover, when the AD-associated TREM2-R47H mutant was used in biochemical assays, apoE binding was vastly reduced. Our data demonstrate that apoE-TREM2 interaction in microglia plays critical roles in modulating phagocytosis of apoE-bound apoptotic neurons and establish a critical link between two proteins whose genes are strongly linked to the risk for AD.
Collapse
Affiliation(s)
| | - Chia-Chen Liu
- From the Department of Neuroscience and the Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361005, China
| | | | - Xiao-Fen Chen
- the Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361005, China
| | | | - Honghua Zheng
- the Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361005, China
| | - Xia Li
- From the Department of Neuroscience and
| | | | | | - Huaxi Xu
- the Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361005, China
| | | | | | - John D Fryer
- From the Department of Neuroscience and the Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, Florida 32224 and
| | - Guojun Bu
- From the Department of Neuroscience and the Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, Fujian 361005, China the Neurobiology of Disease Graduate Program, Mayo Clinic, Jacksonville, Florida 32224 and
| |
Collapse
|
100
|
Bailey CC, DeVaux LB, Farzan M. The Triggering Receptor Expressed on Myeloid Cells 2 Binds Apolipoprotein E. J Biol Chem 2015; 290:26033-42. [PMID: 26374897 DOI: 10.1074/jbc.m115.677286] [Citation(s) in RCA: 204] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Indexed: 12/31/2022] Open
Abstract
The triggering receptor expressed on myeloid cells 2 (TREM2) is an Ig-like V-type receptor expressed by populations of myeloid cells in the central nervous system and periphery. Loss-of-function mutations in TREM2 cause a progressive, fatal neurodegenerative disorder called Nasu-Hakola disease. In addition, a TREM2 R47H coding variant was recently identified as a risk factor for late-onset Alzheimer disease. TREM2 binds various polyanionic molecules but no specific protein ligands have been identified. Here we show that TREM2 specifically binds apolipoprotein E, a well established participant in Alzheimer disease. TREM2-Ig fusions efficiently precipitate ApoE from cerebrospinal fluid and serum. TREM2 also binds recombinant ApoE in solution and immobilized ApoE as detected by ELISA. Furthermore, the Alzheimer disease-associated R47H mutation, and other artificial mutations introduced in the same location, markedly reduced the affinity of TREM2 for ApoE. These findings reveal a link between two Alzheimer disease risk factors and may provide important clues to the pathogenesis of Nasu-Hakola disease and other neurodegenerative disorders.
Collapse
Affiliation(s)
- Charles C Bailey
- From the Department of Immunobiology and Microbial Sciences, The Scripps Research Institute, Jupiter, Florida 33458
| | - Lindsey B DeVaux
- From the Department of Immunobiology and Microbial Sciences, The Scripps Research Institute, Jupiter, Florida 33458
| | - Michael Farzan
- From the Department of Immunobiology and Microbial Sciences, The Scripps Research Institute, Jupiter, Florida 33458
| |
Collapse
|