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Bharadwaj S, Groza Y, Mierzwicka JM, Malý P. Current understanding on TREM-2 molecular biology and physiopathological functions. Int Immunopharmacol 2024; 134:112042. [PMID: 38703564 DOI: 10.1016/j.intimp.2024.112042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/05/2024] [Accepted: 04/05/2024] [Indexed: 05/06/2024]
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM-2), a glycosylated receptor belonging to the immunoglobin superfamily and especially expressed in the myeloid cell lineage, is frequently explained as a reminiscent receptor for both adaptive and innate immunity regulation. TREM-2 is also acknowledged to influence NK cell differentiation via the PI3K and PLCγ signaling pathways, as well as the partial activation or direct inhibition of T cells. Additionally, TREM-2 overexpression is substantially linked to cell-specific functions, such as enhanced phagocytosis, reduced toll-like receptor (TLR)-mediated inflammatory cytokine production, increased transcription of anti-inflammatory cytokines, and reshaped T cell function. Whereas TREM-2-deficient cells exhibit diminished phagocytic function and enhanced proinflammatory cytokines production, proceeding to inflammatory injuries and an immunosuppressive environment for disease progression. Despite the growing literature supporting TREM-2+ cells in various diseases, such as neurodegenerative disorders and cancer, substantial facets of TREM-2-mediated signaling remain inadequately understood relevant to pathophysiology conditions. In this direction, herein, we have summarized the current knowledge on TREM-2 biology and cell-specific TREM-2 expression, particularly in the modulation of pivotal TREM-2-dependent functions under physiopathological conditions. Furthermore, molecular regulation and generic biological relevance of TREM-2 are also discussed, which might provide an alternative approach for preventing or reducing TREM-2-associated deformities. At last, we discussed the TREM-2 function in supporting an immunosuppressive cancer environment and as a potential drug target for cancer immunotherapy. Hence, summarized knowledge of TREM-2 might provide a window to overcome challenges in clinically effective therapies for TREM-2-induced diseases in humans.
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Affiliation(s)
- Shiv Bharadwaj
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic.
| | - Yaroslava Groza
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Joanna M Mierzwicka
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Petr Malý
- Laboratory of Ligand Engineering, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV Research Center, Průmyslová 595, 252 50 Vestec, Czech Republic.
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2
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Liang S, Xu L, Xin X, Zhang R, Wu Y. Study on pyroptosis-related genes Casp8, Gsdmd and Trem2 in mice with cerebral infarction. PeerJ 2024; 12:e16818. [PMID: 38348100 PMCID: PMC10860548 DOI: 10.7717/peerj.16818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/30/2023] [Indexed: 02/15/2024] Open
Abstract
Objective Cerebral infarction is the main cause of death in patients with cerebrovascular diseases. Our research aimed to screen and validate pyroptosis-related genes in cerebral infarction for the targeted therapy of cerebral infarction. Methods and results A total of 1,517 differentially expressed genes (DEGs) were obtained by DESeq2 software analysis. Gene set enrichment analysis results indicated that genes of middle cerebral artery occlusion (MCAO) mice aged 3 months and 18 months were enriched in pyroptosis, respectively. Differentially expressed pyroptosis-related genes (including Aim2, Casp8, Gsdmd, Naip2, Naip5, Naip6 and Trem2) were obtained through intersection of DEGs and genes from pyroptosis Gene Ontology Term (GO:0070269), and they were up-regulated in the brain tissues of MCAO mice in GSE137482. In addition, Casp8, Gsdmd, and Trem2 were verified to be significantly up-regulated in MCAO mice in GSE93376. The evaluation of neurologic function and triphenyltetrazolium chloride staining showed that the MCAO mouse models were successfully constructed. Meanwhile, the expressions of TNF-α, pyroptosis-related proteins, Casp8, Gsdmd and Trem2 in MCAO mice were significantly up-regulated. We selected Trem2 for subsequent functional analysis. OGD treatment of BV2 cell in vitro significantly upregulated the expressions of Trem2. Subsequent downregulation of Trem2 expression in OGD-BV2 cells further increased the level of pyroptosis. Therefore, Trem2 is a protective factor regulating pyroptosis, thus influencing the progression of cerebral infarction. Conclusions Casp8, Gsdmd and Trem2 can regulate pyroptosis, thus affecting cerebral infarction.
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Affiliation(s)
- Shunli Liang
- Department of Neurology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
- The Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Linsheng Xu
- Department of Neurology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Xilin Xin
- Department of Neurology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Rongbo Zhang
- Department of Neurology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - You Wu
- Department of Neurology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
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Ruiz-De-La-Cruz G, Sifuentes-Rincón AM, Paredes-Sánchez FA, Parra-Bracamonte GM, Casas E, Riley DG, Perry GA, Welsh TH, Randel RD. Analysis of nonsynonymous SNPs in candidate genes that influence bovine temperament and evaluation of their effect in Brahman cattle. Mol Biol Rep 2024; 51:285. [PMID: 38324050 PMCID: PMC10850011 DOI: 10.1007/s11033-024-09264-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/17/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND Temperament is an important production trait in cattle and multiple strategies had been developed to generate molecular markers to assist animal selection. As nonsynonymous single nucleotide polymorphisms are markers with the potential to affect gene functions, they could be useful to predict phenotypic effects. Genetic selection of less stress-responsive, temperamental animals is desirable from an economic and welfare point of view. METHODS AND RESULTS Two nonsynonymous single nucleotide polymorphisms identified in HTR1B and SLC18A2 candidate genes for temperament were analyzed in silico to determine their effects on protein structure. Those nsSNPs allowing changes in proteins were selected for a temperament association analysis in a Brahman population. Transversion effects on protein structure were evaluated in silico for each amino acid change model, revealing structural changes in the proteins of the HTR1B and SLC18A2 genes. The selected nsSNPs were genotyped in a Brahman population (n = 138), and their genotypic effects on three temperament traits were analyzed: exit velocity, pen score, and temperament score. Only the SNP rs209984404-HTR1B (C/A) showed a significant association (P = 0.0144) with pen score. The heterozygous genotype showed a pen score value 1.17 points lower than that of the homozygous CC genotype. CONCLUSION The results showed that in silico analysis could direct the selection of nsSNPs with the potential to change the protein. Non-synonymous single nucleotide polymorphisms causing structural changes and reduced protein stability were identified. Only rs209984404-HTR1B shows that the allele affecting protein stability was associated with the genotype linked to docility in cattle.
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Affiliation(s)
- Gilberto Ruiz-De-La-Cruz
- Laboratorio de Biotecnología Animal, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa, Tamaulipas, 88710, México
| | - Ana María Sifuentes-Rincón
- Laboratorio de Biotecnología Animal, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa, Tamaulipas, 88710, México.
| | | | - Gaspar Manuel Parra-Bracamonte
- Laboratorio de Biotecnología Animal, Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa, Tamaulipas, 88710, México
| | - Eduardo Casas
- National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, 50010, USA
| | - David G Riley
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | | | - Thomas H Welsh
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
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Abdul-Rahman T, Ghosh S, Kalmanovich JB, Awuah AW, Zivcevska M, Khalifa S, Bassey EE, Ali NA, Ferreira MMDS, Umar TP, Garg N, Nweze VN, Inturu VSS, Abdelwahab MM, Kurian S, Alexiou A, Alfaleh M, Alqurashi TMA, Ashraf GM. The role of membrane trafficking and retromer complex in Parkinson's and Alzheimer's disease. J Neurosci Res 2024; 102:e25261. [PMID: 38284858 DOI: 10.1002/jnr.25261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 09/16/2023] [Accepted: 10/03/2023] [Indexed: 01/30/2024]
Abstract
Membrane trafficking is a physiological process encompassing different pathways involved in transporting cellular products across cell membranes to specific cell locations via encapsulated vesicles. This process is required for cells to mature and function properly, allowing them to adapt to their surroundings. The retromer complex is a complex composed of nexin proteins and peptides that play a vital role in the endosomal pathway of membrane trafficking. In humans, any interference in normal membrane trafficking or retromer complex can cause profound changes such as those seen in neurodegenerative disorders such as Alzheimer's and Parkinson's. Several studies have explored the potential causative mechanisms in developing both disease processes; however, the role of retromer trafficking in their pathogenesis is becoming increasingly significant with promising therapeutic applications. This manuscript describes the processes involved in membrane transport and the roles of the retromer in the onset and progression of Alzheimer's and Parkinson's. Moreover, we will also explore how these aberrant mechanisms may serve as possible avenues for treatment development in both diseases and the prospect of its future application.
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Affiliation(s)
| | - Shankhaneel Ghosh
- Institute of Medical Sciences and SUM Hospital, Siksha 'O' Anusandhan, Bhubaneswar, India
| | | | | | - Marija Zivcevska
- Liberty University College of Osteopathic Medicine, Lynchburg, Virginia, USA
| | - Samar Khalifa
- Clinical Psychology Department, Faculty of Arts, Kafrelsheikh University, Kafr Elsheikh, Egypt
| | | | | | | | - Tungki Pratama Umar
- UCL Centre for Nanotechnology and Regenerative Medicine, Division of Surgery and Interventional Science, University College London, London, UK
| | - Neil Garg
- Rowan-Virtua School of Osteopathic Medicine, One Medical Center Drive Stratford, Stratford, New Jersey, USA
| | | | | | | | | | - Athanasios Alexiou
- Department of Science and Engineering, Novel Global Community Educational Foundation, Hebersham, New South Wales, Australia
- AFNP Med, Wien, Austria
| | - Mohammed Alfaleh
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Thamer M A Alqurashi
- Department of Pharmacology, Medical College, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Ghulam Md Ashraf
- Department of Medical Laboratory Sciences, College of Health Sciences, Research Institute for Medical and Health Sciences, University of Sharjah, Sharjah, United Arab Emirates
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TREM2 and Microglia Contribute to the Synaptic Plasticity: from Physiology to Pathology. Mol Neurobiol 2023; 60:512-523. [PMID: 36318443 DOI: 10.1007/s12035-022-03100-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/20/2022] [Indexed: 11/07/2022]
Abstract
Synapses are bridges for information transmission in the central nervous system (CNS), and synaptic plasticity is fundamental for the normal function of synapses, contributing substantially to learning and memory. Numerous studies have proven that microglia can participate in the occurrence and progression of neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD), by regulating synaptic plasticity. In this review, we summarize the main characteristics of synapses and synaptic plasticity under physiological and pathological conditions. We elaborate the origin and development of microglia and the two well-known microglial signaling pathways that regulate synaptic plasticity. We also highlight the unique role of triggering receptor expressed on myeloid cells 2 (TREM2) in microglia-mediated regulation of synaptic plasticity and its relationship with AD. Finally, we propose four possible ways in which TREM2 is involved in regulating synaptic plasticity. This review will help researchers understand how NDDs develop from the perspective of synaptic plasticity.
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Tarawneh R, Penhos E. The gut microbiome and Alzheimer's disease: Complex and bidirectional interactions. Neurosci Biobehav Rev 2022; 141:104814. [PMID: 35934087 PMCID: PMC9637435 DOI: 10.1016/j.neubiorev.2022.104814] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/16/2022] [Accepted: 08/01/2022] [Indexed: 11/20/2022]
Abstract
Structural and functional alterations to the gut microbiome, referred to as gut dysbiosis, have emerged as potential key mediators of neurodegeneration and Alzheimer disease (AD) pathogenesis through the "gut -brain" axis. Emerging data from animal and clinical studies support an important role for gut dysbiosis in mediating neuroinflammation, central and peripheral immune dysregulation, abnormal brain protein aggregation, and impaired intestinal and brain barrier permeability, leading to neuronal loss and cognitive impairment. Gut dysbiosis has also been shown to directly influence various mechanisms involved in neuronal growth and repair, synaptic plasticity, and memory and learning functions. Aging and lifestyle factors including diet, exercise, sleep, and stress influence AD risk through gut dysbiosis. Furthermore, AD is associated with characteristic gut microbial signatures which offer value as potential markers of disease severity and progression. Together, these findings suggest the presence of a complex bidirectional relationship between AD and the gut microbiome and highlight the utility of gut modulation strategies as potential preventative or therapeutic strategies in AD. We here review the current literature regarding the role of the gut-brain axis in AD pathogenesis and its potential role as a future therapeutic target in AD treatment and/or prevention.
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Affiliation(s)
- Rawan Tarawneh
- Department of Neurology, Center for Memory and Aging, Alzheimer Disease Research Center, The University of New Mexico, Albuquerque, NM 87106, USA.
| | - Elena Penhos
- College of Medicine, The Ohio State University, Columbus, OH, USA 43210
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The role of Triggering Receptor Expressed on Myeloid Cells 2 in Parkinson's disease and other neurodegenerative disorders. Behav Brain Res 2022; 433:113977. [PMID: 35752274 DOI: 10.1016/j.bbr.2022.113977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/09/2022] [Accepted: 06/21/2022] [Indexed: 11/23/2022]
Abstract
Parkinson's disease (PD) is a progressive neurological disorder marked by cardinal clinical symptoms such as rigor, tremor, and akinesia. Albeit a loss of dopaminergic neurons from the substantia nigra pars compacta is causative for the movement impairments found in patients, molecular reasoning for this loss is still incomplete. In recent years, triggering factor expressed on myeloid cells (TREM2) gained attention in the field of neurodegeneration as it could be associated with different neurodegenerative disorders. Primarily identified as a risk factor in Alzheimer's disease, variants in TREM2 were linked to PD and multiple sclerosis, too. Expressed on phagocytic cells, such as macrophages and microglia, TREM2 puts the focus on inflammation associated conditions in PD and provides a molecular target that could at least partly explain the role of immune cells in PD. Here, we summarize expression patterns and molecular functions of TREM2, recapitulate on its role in inflammation, phagocytosis and cell survival, before turning to neurodegenerative disorders with an emphasis on PD.
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8
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Yasmeen N, Datta M, Kumar V, Alshehri FS, Almalki AH, Haque S. Deciphering the Link Between ERUPR Signaling and MicroRNA in Pathogenesis of Alzheimer’s Disease. Front Aging Neurosci 2022; 14:880167. [PMID: 35615589 PMCID: PMC9126300 DOI: 10.3389/fnagi.2022.880167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/23/2022] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative proteinopathic disease. The deposits of misfolded Amyloid β and Tau proteins in the brain of patients with AD suggest an imbalance in endoplasmic reticulum (ER) proteostasis. ER stress is due to accumulation of aberrant proteins in the ER lumen, which then leads to activation of three sensor protein pathways that ultimately evokes the adaptive mechanism of the unfolded protein response (UPR). The UPR mechanism operates via adaptive UPR and the apoptotic UPR. Adaptive UPR tries to restore imbalance in ER hemostasis by decreasing protein production, enhanced chaperone involvement to restore protein folding, misfolded protein decay by proteasome, and suppression of ribosomal translation ultimately relieving the excessive protein load in the ER. Subsequently, apoptotic UPR activated under severe ER stress conditions triggers cell death. MicroRNAs (miRNAs) are small non-coding protein causing dysregulated translational of mRNAs in a sequential manner. They are considered to be critical elements in the maintenance of numerous cellular activities, hemostasis, and developmental processes. Therefore, upregulation or downregulation of miRNA expression is implicated in several pathogenic processes. Evidence from scientific studies suggest a strong correlation between ERUPR signaling and miRNA dysregulation but the research done is still dormant. In this review, we summarized the cross-talk between ER stress, and the UPR signaling processes and their role in AD pathology by scrutinizing and collecting information from original research and review articles.
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Affiliation(s)
- Nusrath Yasmeen
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Manali Datta
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Vikram Kumar
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
- *Correspondence: Vikram Kumar, ;
| | - Fahad S. Alshehri
- Department of Pharmacology and Toxicology, College of Pharmacy, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Atiah H. Almalki
- Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University, Taif, Saudi Arabia
- Addiction and Neuroscience Research Unit, College of Pharmacy, Taif University, Taif, Saudi Arabia
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
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Durai P, Beeraka NM, Ramachandrappa HVP, Krishnan P, Gudur P, Raghavendra NM, Ravanappa PKB. Advances in PPARs Molecular Dynamics and Glitazones as a Repurposing Therapeutic Strategy through Mitochondrial Redox Dynamics against Neurodegeneration. Curr Neuropharmacol 2022; 20:893-915. [PMID: 34751120 PMCID: PMC9881103 DOI: 10.2174/1570159x19666211109141330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 08/20/2021] [Accepted: 09/17/2021] [Indexed: 11/22/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) activity has significant implications for the development of novel therapeutic modalities against neurodegenerative diseases. Although PPAR-α, PPAR-β/δ, and PPAR-γ nuclear receptor expressions are significantly reported in the brain, their implications in brain physiology and other neurodegenerative diseases still require extensive studies. PPAR signaling can modulate various cell signaling mechanisms involved in the cells contributing to on- and off-target actions selectively to promote therapeutic effects as well as the adverse effects of PPAR ligands. Both natural and synthetic ligands for the PPARα, PPARγ, and PPARβ/δ have been reported. PPARα (WY 14.643) and PPARγ agonists can confer neuroprotection by modulating mitochondrial dynamics through the redox system. The pharmacological effect of these agonists may deliver effective clinical responses by protecting vulnerable neurons from Aβ toxicity in Alzheimer's disease (AD) patients. Therefore, the current review delineated the ligands' interaction with 3D-PPARs to modulate neuroprotection, and also deciphered the efficacy of numerous drugs, viz. Aβ aggregation inhibitors, vaccines, and γ-secretase inhibitors against AD; this review elucidated the role of PPAR and their receptor isoforms in neural systems, and neurodegeneration in human beings. Further, we have substantially discussed the efficacy of PPREs as potent transcription factors in the brain, and the role of PPAR agonists in neurotransmission, PPAR gamma coactivator-1α (PGC-1α) and mitochondrial dynamics in neuroprotection during AD conditions. This review concludes with the statement that the development of novel PPARs agonists may benefit patients with neurodegeneration, mainly AD patients, which may help mitigate the pathophysiology of dementia, subsequently improving overall the patient's quality of life.
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Affiliation(s)
- Priya Durai
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru 570 015, India and JSS Academy of Higher Education & Research, Mysuru, Karnataka, India
| | - Narasimha M. Beeraka
- Center of Excellence in Regenerative Medicine and Molecular Biology (CEMR), Department of Biochemistry, JSS Medical College, JSS Academy of Higher Education & Research, Mysuru 570 015, Karnataka, India;,I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow 119146, Russia
| | - Hemanth Vikram Poola Ramachandrappa
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru 570 015, India and JSS Academy of Higher Education & Research, Mysuru, Karnataka, India
| | | | - Pranesh Gudur
- Swamy Vivekananda Yoga Anusandhana Samsthana Deemed University, Bengaluru 560 105, India
| | | | - Prashantha Kumar Bommenahally Ravanappa
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru 570 015, India and JSS Academy of Higher Education & Research, Mysuru, Karnataka, India;,Address correspondence to this author at the Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru 570 015, India and JSS Academy of Higher Education & Research (JSS AHER), Mysuru, Karnataka, India; E-mail:
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10
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Kulkarni B, Cruz-Martins N, Kumar D. Microglia in Alzheimer's Disease: An Unprecedented Opportunity as Prospective Drug Target. Mol Neurobiol 2022; 59:2678-2693. [PMID: 35149973 DOI: 10.1007/s12035-021-02661-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/20/2021] [Indexed: 12/27/2022]
Abstract
Alzheimer's disease (AD) is an ever more common neurodegenerative disease among the elderly, characterized by recurrent neuroinflammation and amyloid beta (Aβ) accumulation in the brain parenchyma. Recent genome-wide association studies (GWAS) have shown a distinct role for the innate immune system in AD, with microglia playing a key role. The function of microglial cells is stringently regulated by the neighboring microenvironment in the brain. Upon interruption in diseases, like AD, it demonstrates neurotoxic and neuroprotective action by M1 (neurotoxic) and M2 (neuroprotective) microglial phenotypes, respectively, in the brain. Microglial cells on activation by complement factors, toll-like receptors, and genetic variants result in Aβ' phagocytosis, synaptic pruning, and reactivation of complement pathway. Recent studies have demonstrated the presence of potential therapeutic targets in microglial cells. Immune receptors revealed on microglia as potential drug targets can be paired immunoglobulin-like type 2 receptor (PILR), CD3358, and triggering receptor expressed on myeloid cells 2 (TREM2), as they can have impact on late-onset AD occurrence and progression. Thus, targeting these receptors can accentuate the beneficial effects of microglial cells required to decelerate the progression of AD. This review emphasizes the microglial phenotypes, its function in AD brain, and potential immunological and therapeutic targets to fight this highly progressive neurodegenerative disorder.
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Affiliation(s)
- Bhargavi Kulkarni
- Poona College of Pharmacy, Bharati Vidyapeeth (Deemed To Be University) Erandawane, Pune, 411038, Maharashtra, India
| | - Natália Cruz-Martins
- Institute of Research and Advanced, Training in Health Sciences and Technologies (CESPU), Rua Central de Gandra, 1317, 4585-116, Gandra, PRD, Portugal. .,Faculty of Medicine, University of Porto, Alameda Prof. Hernani Monteiro, 4200-319, Porto, Portugal. .,Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135, Porto, Portugal.
| | - Dileep Kumar
- Poona College of Pharmacy, Bharati Vidyapeeth (Deemed To Be University) Erandawane, Pune, 411038, Maharashtra, India.
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11
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Akhter R, Shao Y, Formica S, Khrestian M, Bekris LM. TREM2 alters the phagocytic, apoptotic and inflammatory response to Aβ 42 in HMC3 cells. Mol Immunol 2021; 131:171-179. [PMID: 33461764 DOI: 10.1016/j.molimm.2020.12.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/20/2020] [Accepted: 12/30/2020] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is characterized by the accumulation in the brain of extracellular amyloid β (Aβ) plaques as well as intraneuronal inclusions (neurofibrillary tangles) consisting of total tau and phosphorylated tau. Also present are dystrophic neurites, loss of synapses, neuronal death, and gliosis. AD genetic studies have highlighted the importance of inflammation in this disease by identifying several risk associated immune response genes, including TREM2. TREM2 has been strongly implicated in basic microglia function including, phagocytosis, apoptosis, and the inflammatory response to Aβ in mouse brain and primary cells. These studies show that microglia are key players in the response to Aβ and in the accumulation of AD pathology. However, details are still missing about which apoptotic or inflammatory factors rely on TREM2 in their response to Aβ, especially in human cell lines. Given these previous findings our hypothesis is that TREM2 influences the response to Aβ toxicity by enhancing phagocytosis and inhibiting both the BCL-2 family of apoptotic proteins and pro-inflammatory cytokines. Aβ42 treatment of the human microglial cell line, HMC3 cells, was performed and TREM2 was overexpressed or silenced and the phagocytosis, apoptosis and inflammatory response were evaluated. Results indicate that a robust phagocytic response to Aβ after 24 h requires TREM2 in HMC3 cells. Also, TREM2 inhibits Aβ induced apoptosis by activating the Mcl-1/Bim complex. TREM2 is involved in activation of IP-10, MIP-1a, and IL-8, while it inhibits FGF-2, VEGF and GRO. Taken together, TREM2 plays a role in enhancing the microglial functional response to Aβ toxicity in HMC3 cells. This novel information suggests that therapeutic strategies that seek to activate TREM2 may not only enhance phagocytosis and inhibit apoptosis, but may also inhibit beneficial inflammatory factors, emphasizing the need to define TREM2-related inflammatory activity in not only mouse models of AD, but also in human AD.
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Affiliation(s)
- Rumana Akhter
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Yvonne Shao
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Shane Formica
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Maria Khrestian
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Lynn M Bekris
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
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Rabiee N, Ahmadi S, Afshari R, Khalaji S, Rabiee M, Bagherzadeh M, Fatahi Y, Dinarvand R, Tahriri M, Tayebi L, Hamblin MR, Webster TJ. Polymeric Nanoparticles for Nasal Drug Delivery to the Brain: Relevance to Alzheimer's Disease. ADVANCED THERAPEUTICS 2020. [DOI: 10.1002/adtp.202000076] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Navid Rabiee
- Department of Chemistry Sharif University of Technology Tehran 11155‐3516 Iran
| | - Sepideh Ahmadi
- Student Research Committee Department of Medical Biotechnology School of Advanced Technologies in Medicine Shahid Beheshti University of Medical Sciences Tehran 19857‐17443 Iran
- Cellular and Molecular Biology Research Center Shahid Beheshti University of Medical Sciences Tehran 19857‐17443 Iran
| | - Ronak Afshari
- Department of Physics Sharif University of Technology P.O. Box 11155‐9161 Tehran Iran
| | - Samira Khalaji
- Biomaterial Group Department of Biomedical Engineering Amirkabir University of Technology Tehran 15875‐4413 Iran
| | - Mohammad Rabiee
- Biomaterial Group Department of Biomedical Engineering Amirkabir University of Technology Tehran 15875‐4413 Iran
| | - Mojtaba Bagherzadeh
- Department of Chemistry Sharif University of Technology Tehran 11155‐3516 Iran
| | - Yousef Fatahi
- Department of Pharmaceutical Nanotechnology Faculty of Pharmacy Tehran University of Medical Sciences Tehran 14155‐6451 Iran
- Nanotechnology Research Center Faculty of Pharmacy Tehran University of Medical Sciences Tehran 14155‐6451 Iran
- Universal Scientific Education and Research Network (USERN) Tehran 15875‐4413 Iran
| | - Rassoul Dinarvand
- Department of Pharmaceutical Nanotechnology Faculty of Pharmacy Tehran University of Medical Sciences Tehran 14155‐6451 Iran
- Nanotechnology Research Center Faculty of Pharmacy Tehran University of Medical Sciences Tehran 14155‐6451 Iran
| | - Mohammadreza Tahriri
- Department of Developmental Sciences Marquette University Milwaukee WI 53233 USA
| | - Lobat Tayebi
- Department of Developmental Sciences Marquette University Milwaukee WI 53233 USA
| | - Michael R. Hamblin
- Wellman Center for Photomedicine Massachusetts General Hospital Boston USA
- Department of Dermatology Harvard Medical School Boston USA
- Laser Research Centre Faculty of Health Science University of Johannesburg Doornfontein 2028 South Africa
| | - Thomas J. Webster
- Department of Chemical Engineering Northeastern University Boston MA 02115 USA
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13
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Zhan L, Fan L, Kodama L, Sohn PD, Wong MY, Mousa GA, Zhou Y, Li Y, Gan L. A MAC2-positive progenitor-like microglial population is resistant to CSF1R inhibition in adult mouse brain. eLife 2020; 9:51796. [PMID: 33054973 PMCID: PMC7591254 DOI: 10.7554/elife.51796] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/14/2020] [Indexed: 12/26/2022] Open
Abstract
Microglia are the resident myeloid cells in the central nervous system (CNS). The majority of microglia rely on CSF1R signaling for survival. However, a small subset of microglia in mouse brains can survive without CSF1R signaling and reestablish the microglial homeostatic population after CSF1R signaling returns. Using single-cell transcriptomic analysis, we characterized the heterogeneous microglial populations under CSF1R inhibition, including microglia with reduced homeostatic markers and elevated markers of inflammatory chemokines and proliferation. Importantly, MAC2/Lgals3 was upregulated under CSF1R inhibition, and shared striking similarities with microglial progenitors in the yolk sac and immature microglia in early embryos. Lineage-tracing studies revealed that these MAC2+ cells were of microglial origin. MAC2+ microglia were also present in non-treated adult mouse brains and exhibited immature transcriptomic signatures indistinguishable from those that survived CSF1R inhibition, supporting the notion that MAC2+ progenitor-like cells are present among adult microglia.
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Affiliation(s)
- Lihong Zhan
- Gladstone Institute of Neurological Diseases, San Francisco, United States
| | - Li Fan
- Helen and Robert Appel Alzheimer's Disease Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | - Lay Kodama
- Gladstone Institute of Neurological Diseases, San Francisco, United States.,Helen and Robert Appel Alzheimer's Disease Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States.,Neuroscience Graduate Program, University of California, San Francisco, San Francisco, United States.,Medical Scientist Training Program, University of California at San Francisco, San Francisco, United States
| | - Peter Dongmin Sohn
- Gladstone Institute of Neurological Diseases, San Francisco, United States
| | - Man Ying Wong
- Helen and Robert Appel Alzheimer's Disease Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | - Gergey Alzaem Mousa
- Helen and Robert Appel Alzheimer's Disease Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States
| | - Yungui Zhou
- Gladstone Institute of Neurological Diseases, San Francisco, United States
| | - Yaqiao Li
- Gladstone Institute of Neurological Diseases, San Francisco, United States
| | - Li Gan
- Gladstone Institute of Neurological Diseases, San Francisco, United States.,Helen and Robert Appel Alzheimer's Disease Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, United States.,Neuroscience Graduate Program, University of California, San Francisco, San Francisco, United States
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14
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Toomey CE, Heywood W, Benson BC, Packham G, Mills K, Lashley T. Investigation of pathology, expression and proteomic profiles in human TREM2 variant postmortem brains with and without Alzheimer's disease. Brain Pathol 2020; 30:794-810. [PMID: 32267026 PMCID: PMC8018003 DOI: 10.1111/bpa.12842] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/11/2020] [Accepted: 03/26/2020] [Indexed: 12/17/2022] Open
Abstract
Triggering receptor expressed on myeloid cells 2 TREM2 was identified as a risk factor for late onset Alzheimer’s disease (AD). Here we compared TREM2 cases with a variant (TREM2+) and cases without a TREM2 variant (TREM2−), considering pathological burden, inflammatory response and altered canonical pathways and biochemical functions between the cohorts. We hypothesised that TREM2+ cases would have a loss of function, indicating an altered inflammatory profile compared to TREM2− cases. Immunohistochemistry was performed using antibodies against Aβ, tau and microglia markers in TREM2+ cases, with and without AD, which were compared to sporadic TREM2− AD, familial AD and neurologically normal control cases. Aβ and tau load were measured along with the composition of Aβ plaques, in addition to microglial load and circularity. Expression and proteomic profiles were determined from the frontal cortex of selected cases. TREM2+ control cases had no Aβ or tau deposition. No differences in the amount of Aβ or tau, or the composition of Aβ plaques were observed between TREM2+ and TREM2− SAD cases. There were no differences in microglial load observed between disease groups. However, the TREM2+ SAD cases showed more amoeboid microglia than the TREM2− SAD cases, although no differences in the spatial relationship of microglia and Aβ plaques were identified. Visualisation of the canonical pathways and biological functions showed differences between the disease groups and the normal controls, clearly showing a number of pathways upregulated in TREM2+ SAD, TREM2− SAD and FAD groups whilst, the TREM2+ controls cases showed a downregulation of the majority of the represented pathways. These findings suggest that the TREM2+ control group, although carrying the TREM2+ variant, have no pathological hallmarks of AD, have altered microglial and expression profiles compared to the TREM2+ SAD cases. This indicates that other unknown factors may initiate the onset of AD, with TREM2 influencing the microglial involvement in disease pathogenesis.
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Affiliation(s)
- Christina E Toomey
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurodegenerative diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Wendy Heywood
- Centre for Translational Omics, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Bridget C Benson
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Georgia Packham
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Kevin Mills
- Centre for Translational Omics, Great Ormond Street Institute of Child Health, UCL, London, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurodegenerative diseases, UCL Queen Square Institute of Neurology, London, UK
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15
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Götzl JK, Brendel M, Werner G, Parhizkar S, Sebastian Monasor L, Kleinberger G, Colombo AV, Deussing M, Wagner M, Winkelmann J, Diehl-Schmid J, Levin J, Fellerer K, Reifschneider A, Bultmann S, Bartenstein P, Rominger A, Tahirovic S, Smith ST, Madore C, Butovsky O, Capell A, Haass C. Opposite microglial activation stages upon loss of PGRN or TREM2 result in reduced cerebral glucose metabolism. EMBO Mol Med 2020; 11:emmm.201809711. [PMID: 31122931 PMCID: PMC6554672 DOI: 10.15252/emmm.201809711] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Microglia adopt numerous fates with homeostatic microglia (HM) and a microglial neurodegenerative phenotype (MGnD) representing two opposite ends. A number of variants in genes selectively expressed in microglia are associated with an increased risk for neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). Among these genes are progranulin (GRN) and the triggering receptor expressed on myeloid cells 2 (TREM2). Both cause neurodegeneration by mechanisms involving loss of function. We have now isolated microglia from Grn−/− mice and compared their transcriptomes to those of Trem2−/−mice. Surprisingly, while loss of Trem2 enhances the expression of genes associated with a homeostatic state, microglia derived from Grn−/− mice showed a reciprocal activation of the MGnD molecular signature and suppression of gene characteristic for HM. The opposite mRNA expression profiles are associated with divergent functional phenotypes. Although loss of TREM2 and progranulin resulted in opposite activation states and functional phenotypes of microglia, FDG (fluoro‐2‐deoxy‐d‐glucose)‐μPET of brain revealed reduced glucose metabolism in both conditions, suggesting that opposite microglial phenotypes result in similar wide spread brain dysfunction.
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Affiliation(s)
- Julia K Götzl
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Georg Werner
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Samira Parhizkar
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - 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
| | | | - Maximilian Deussing
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Matias Wagner
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany.,Institut of Human Genetics, Technische Universität München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Juliane Winkelmann
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany.,Institut of Human Genetics, Technische Universität München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Johannes Levin
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katrin Fellerer
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anika Reifschneider
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sebastian Bultmann
- Department of Biology and Center for Integrated Protein Science Munich (CIPSM), Ludwig Maximilians-Universität München, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Scott T Smith
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Charlotte Madore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Oleg Butovsky
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Evergrande Center for Immunologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Anja Capell
- Chair of Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, 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, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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16
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Dash R, Choi HJ, Moon IS. Mechanistic insights into the deleterious roles of Nasu-Hakola disease associated TREM2 variants. Sci Rep 2020; 10:3663. [PMID: 32107424 PMCID: PMC7046722 DOI: 10.1038/s41598-020-60561-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 02/13/2020] [Indexed: 02/06/2023] Open
Abstract
Recently, the critical roles played by genetic variants of TREM2 (Triggering Receptor Expressed on Myeloid cells 2) in Alzheimer's disease have been aggressively highlighted. However, few studies have focused on the deleterious roles of Nasu-Hakola disease (NHD) associated TREM2 variants. In order to get insights into the contributions made by these variants to neurodegeneration, we investigated the influences of four NHD associated TREM2 mutations (Y38C, W50C, T66M, and V126G) on loss-of-function, and followed this with in silico prediction and conventional molecular dynamics simulation. NHD mutations were predicted to be highly deleterious by eight different in silico bioinformatics tools and found to induce conformational changes by molecular dynamics simulation. As compared with the wild-type, the four variants produced substantial differences in the collective motions of loop regions, which not only promoted structural remodeling in the CDR2 (complementarity-determining region 2) loop but also in the CDR1 loop, by changing inter- and intra-loop hydrogen bonding networks. In addition, structural studies in a free energy landscape analysis showed that Y38, T66, and V126 are crucial for maintaining the structural features of CDR1 and CDR2 loops, and that mutations in these positions produced steric clashes and loss of ligand binding. These results showed the presence of mutations in the TREM2 ectodomain induced flexibility and caused structural alterations. Dynamical scenarios, as provided by the present study, may be critical to our understanding of the roles of these TREM2 mutations in neurodegenerative diseases.
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Affiliation(s)
- Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Ho Jin Choi
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, 38066, Republic of Korea.
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17
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Sharma A, Kazim SF, Larson CS, Ramakrishnan A, Gray JD, McEwen BS, Rosenberg PA, Shen L, Pereira AC. Divergent roles of astrocytic versus neuronal EAAT2 deficiency on cognition and overlap with aging and Alzheimer's molecular signatures. Proc Natl Acad Sci U S A 2019; 116:21800-21811. [PMID: 31591195 PMCID: PMC6815169 DOI: 10.1073/pnas.1903566116] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The excitatory amino acid transporter 2 (EAAT2) is the major glutamate transporter in the brain expressed predominantly in astrocytes and at low levels in neurons and axonal terminals. EAAT2 expression is reduced in aging and sporadic Alzheimer's disease (AD) patients' brains. The role EAAT2 plays in cognitive aging and its associated mechanisms remains largely unknown. Here, we show that conditional deletion of astrocytic and neuronal EAAT2 results in age-related cognitive deficits. Astrocytic, but not neuronal EAAT2, deletion leads to early deficits in short-term memory and in spatial reference learning and long-term memory. Neuronal EAAT2 loss results in late-onset spatial reference long-term memory deficit. Neuronal EAAT2 deletion leads to dysregulation of the kynurenine pathway, and astrocytic EAAT2 deficiency results in dysfunction of innate and adaptive immune pathways, which correlate with cognitive decline. Astrocytic EAAT2 deficiency also shows transcriptomic overlaps with human aging and AD. Overall, the present study shows that in addition to the widely recognized astrocytic EAAT2, neuronal EAAT2 plays a role in hippocampus-dependent memory. Furthermore, the gene expression profiles associated with astrocytic and neuronal EAAT2 deletion are substantially different, with the former associated with inflammation and synaptic function similar to changes observed in human AD and gene expression changes associated with inflammation similar to the aging human brain.
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Affiliation(s)
- Abhijeet Sharma
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Syed Faraz Kazim
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Chloe S Larson
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Aarthi Ramakrishnan
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Jason D Gray
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Bruce S McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065;
| | - Paul A Rosenberg
- Department of Neurology and the F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115
| | - Li Shen
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ana C Pereira
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029;
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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18
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Abstract
Microglia are the primary innate immune cells in the CNS. In the healthy brain, they exhibit a unique molecular homeostatic 'signature', consisting of a specific transcriptional profile and surface protein expression pattern, which differs from that of tissue macrophages. In recent years, there have been a number of important advances in our understanding of the molecular signatures of homeostatic microglia and disease-associated microglia that have provided insight into how these cells are regulated in health and disease and how they contribute to the maintenance of the neural environment.
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19
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Wang S, Colonna M. Microglia in Alzheimer's disease: A target for immunotherapy. J Leukoc Biol 2019; 106:219-227. [PMID: 30725482 DOI: 10.1002/jlb.mr0818-319r] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/11/2018] [Accepted: 01/14/2019] [Indexed: 12/29/2022] Open
Abstract
Microglia are resident Mϕs of the CNS that play pleiotropic functions in brain development and homeostasis. Impaired microglial functions are thought to be involved in the onset and progression of various neurodevelopmental and neurodegenerative diseases. Thus, understanding microglia in these settings may indicate new approaches for therapeutic intervention. Here, we review recent evidence implicating microglia in Alzheimer's disease and discuss potential therapeutic strategies targeting microglia and their receptors in this disease.
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Affiliation(s)
- Shoutang Wang
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, Missouri, USA
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20
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Dong Y, Li X, Cheng J, Hou L. Drug Development for Alzheimer's Disease: Microglia Induced Neuroinflammation as a Target? Int J Mol Sci 2019; 20:E558. [PMID: 30696107 PMCID: PMC6386861 DOI: 10.3390/ijms20030558] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/09/2019] [Accepted: 01/13/2019] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is one of the most common causes of dementia. Its pathogenesis is characterized by the aggregation of the amyloid-β (Aβ) protein in senile plaques and the hyperphosphorylated tau protein in neurofibrillary tangles in the brain. Current medications for AD can provide temporary help with the memory symptoms and other cognitive changes of patients, however, they are not able to stop or reverse the progression of AD. New medication discovery and the development of a cure for AD is urgently in need. In this review, we summarized drugs for AD treatments and their recent updates, and discussed the potential of microglia induced neuroinflammation as a target for anti-AD drug development.
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Affiliation(s)
- Yuan Dong
- Department of Biochemistry, Medical College, Qingdao University, Qingdao 266071, China.
| | - Xiaoheng Li
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing 100069, China.
| | - Jinbo Cheng
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing 100850, China.
| | - Lin Hou
- Department of Biochemistry, Medical College, Qingdao University, Qingdao 266071, China.
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21
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Bachiller S, Jiménez-Ferrer I, Paulus A, Yang Y, Swanberg M, Deierborg T, Boza-Serrano A. Microglia in Neurological Diseases: A Road Map to Brain-Disease Dependent-Inflammatory Response. Front Cell Neurosci 2018; 12:488. [PMID: 30618635 PMCID: PMC6305407 DOI: 10.3389/fncel.2018.00488] [Citation(s) in RCA: 428] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia represent a specialized population of macrophages-like cells in the central nervous system (CNS) considered immune sentinels that are capable of orchestrating a potent inflammatory response. Microglia are also involved in synaptic organization, trophic neuronal support during development, phagocytosis of apoptotic cells in the developing brain, myelin turnover, control of neuronal excitability, phagocytic debris removal as well as brain protection and repair. Microglial response is pathology dependent and affects to immune, metabolic. In this review, we will shed light on microglial activation depending on the disease context and the influence of factors such as aging, environment or cell-to-cell interaction.
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Affiliation(s)
- Sara Bachiller
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Itzia Jiménez-Ferrer
- Translational Neurogenetics Unit, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Agnes Paulus
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Yiyi Yang
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
| | - Maria Swanberg
- Translational Neurogenetics Unit, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Lund University, Lund, Sweden
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22
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Zhong L, Jiang X, Zhu Z, Qin H, Dinkins MB, Kong JN, Leanhart S, Wang R, Elsherbini A, Bieberich E, Zhao Y, Wang G. Lipid transporter Spns2 promotes microglia pro-inflammatory activation in response to amyloid-beta peptide. Glia 2018; 67:498-511. [PMID: 30484906 DOI: 10.1002/glia.23558] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/31/2018] [Accepted: 10/22/2018] [Indexed: 12/29/2022]
Abstract
Accumulating evidence indicates that neuroinflammation contributes to the pathogenesis and exacerbation of neurodegenerative disorders, such as Alzheimer's disease (AD). Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid that regulates many pathophysiological processes including inflammation. We present evidence here that the spinster homolog 2 (Spns2), a S1P transporter, promotes microglia pro-inflammatory activation in vitro and in vivo. Spns2 knockout (Spns2KO) in primary cultured microglia resulted in significantly reduced levels of pro-inflammatory cytokines induced by lipopolysaccharide (LPS) and amyloid-beta peptide 1-42 oligomers (Aβ42) when compared with littermate controls. Fingolimod (FTY720), a S1P receptor 1 (S1PR1) functional antagonist and FDA approved drug for relapsing-remitting multiple sclerosis, partially blunted Aβ42-induced pro-inflammatory cytokine generation, suggesting that Spns2 promotes microglia pro-inflammatory activation through S1P-signaling. Spns2KO significantly reduced Aβ42-induced nuclear factor kappa B (NFκB) activity. S1P increased, while FTY720 dampened, Aβ42-induced NFκB activity, suggesting that Spns2 activates microglia inflammation through, at least partially, NFκB pathway. Spns2KO mouse brains showed significantly reduced Aβ42-induced microglia activation/accumulation and reduced levels of pro-inflammatory cytokines when compared with age-matched controls. More interestingly, Spns2KO ameliorated Aβ42-induced working memory deficit detected by Y-Maze. In summary, these results suggest that Spns2 promotes pro-inflammatory polarization of microglia and may play a crucial role in AD pathogenesis.
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Affiliation(s)
- Liansheng Zhong
- Department of Physiology, University of Kentucky, Lexington, Kentucky.,Department of Bioinformatics, Key Laboratory of Cell Biology of Ministry of Public Health, College of Life Sciences, China Medical University, Shenyang, China
| | - Xue Jiang
- Department of Physiology, University of Kentucky, Lexington, Kentucky.,Shengjing Hospital, China Medical University, Shenyang, Liaoning, China
| | - Zhihui Zhu
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Haiyan Qin
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Michael B Dinkins
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Ji-Na Kong
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Silvia Leanhart
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Rebecca Wang
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, Maryland
| | - Ahmed Elsherbini
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Erhard Bieberich
- Department of Physiology, University of Kentucky, Lexington, Kentucky.,Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Yujie Zhao
- Department of Bioinformatics, Key Laboratory of Cell Biology of Ministry of Public Health, College of Life Sciences, China Medical University, Shenyang, China
| | - Guanghu Wang
- Department of Physiology, University of Kentucky, Lexington, Kentucky
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23
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Li JT, Zhang Y. TREM2 regulates innate immunity in Alzheimer's disease. J Neuroinflammation 2018; 15:107. [PMID: 29655369 PMCID: PMC5899410 DOI: 10.1186/s12974-018-1148-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 04/04/2018] [Indexed: 11/10/2022] Open
Abstract
Recent research has shown that the triggering receptor expressed on myeloid cells 2 (TREM2) in microglia is closely related to the pathogenesis of Alzheimer's disease (AD). The mechanism of this relationship, however, remains unclear. TREM2 is part of the TREM family of receptors, which are expressed primarily in myeloid cells, including monocytes, dendritic cells, and microglia. The TREM family members are cell surface glycoproteins with an immunoglobulin-like extracellular domain, a transmembrane region and a short cytoplasmic tail region. The present article reviews the following: (1) the structure, function, and variant site analysis of the Trem2 gene; (2) the metabolism of TREM2 in peripheral blood and cerebrospinal fluid; and (3) the possible underlying mechanism by which TREM2 regulates innate immunity and participates in AD.
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Affiliation(s)
- Jiang-Tao Li
- College of Life Sciences and Bioengineering, Beijing Jiaotong University, No. 3 Shangyuan Residence, Haidian District, Beijing, 100044, China
| | - Ying Zhang
- College of Life Sciences and Bioengineering, Beijing Jiaotong University, No. 3 Shangyuan Residence, Haidian District, Beijing, 100044, China.
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Nano-carrier enabled drug delivery systems for nose to brain targeting for the treatment of neurodegenerative disorders. J Drug Deliv Sci Technol 2018. [DOI: 10.1016/j.jddst.2017.09.022] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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RIPK1 mediates a disease-associated microglial response in Alzheimer's disease. Proc Natl Acad Sci U S A 2017; 114:E8788-E8797. [PMID: 28904096 DOI: 10.1073/pnas.1714175114] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dysfunction of microglia is known to play an important role in Alzheimer's disease (AD). Here, we investigated the role of RIPK1 in microglia mediating the pathogenesis of AD. RIPK1 is highly expressed by microglial cells in human AD brains. Using the amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mouse model, we found that inhibition of RIPK1, using both pharmacological and genetic means, reduced amyloid burden, the levels of inflammatory cytokines, and memory deficits. Furthermore, inhibition of RIPK1 promoted microglial degradation of Aβ in vitro. We characterized the transcriptional profiles of adult microglia from APP/PS1 mice and identified a role for RIPK1 in regulating the microglial expression of CH25H and Cst7, a marker for disease-associated microglia (DAM), which encodes an endosomal/lysosomal cathepsin inhibitor named Cystatin F. We present evidence that RIPK1-mediated induction of Cst7 leads to an impairment in the lysosomal pathway. These data suggest that RIPK1 may mediate a critical checkpoint in the transition to the DAM state. Together, our study highlights a non-cell death mechanism by which the activation of RIPK1 mediates the induction of a DAM phenotype, including an inflammatory response and a reduction in phagocytic activity, and connects RIPK1-mediated transcription in microglia to the etiology of AD. Our results support that RIPK1 is an important therapeutic target for the treatment of AD.
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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.
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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
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Wu R, Li X, Xu P, Huang L, Cheng J, Huang X, Jiang J, Wu LJ, Tang Y. TREM2 protects against cerebral ischemia/reperfusion injury. Mol Brain 2017; 10:20. [PMID: 28592261 PMCID: PMC5461720 DOI: 10.1186/s13041-017-0296-9] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 04/20/2017] [Indexed: 01/01/2023] Open
Abstract
Although post-ischemic inflammation induced by the innate immune response is considered an essential step in the progression of cerebral ischemia injury, the role of triggering receptor expressed on myeloid cells 2 (TREM2) in the pathogenesis of ischemic stroke remains to be elucidated. Here, we found that the transcriptional and post-transcriptional levels of TREM2 were increased in cultured primary microglia after oxygen-glucose deprivation and reoxygenation and in the ischemic penumbra of the cerebral cortex after middle cerebral artery occlusion (MCAO) and reperfusion in mice. TREM2 was mainly expressed in microglia, but not in astrocytes, neurons, or oligodendrocytes in mice subjected to MCAO. Manipulating TREM2 expression levels in vitro and in vivo significantly regulated the production of pro- and anti-inflammatory mediators after ischemic stroke. TREM2 overexpression markedly suppressed the inflammatory response and neuronal apoptosis. By contrast, TREM2 gene silencing intensified the inflammatory response, increased neuronal apoptosis and infarct volume, and further exacerbated neurological dysfunction. Our study demonstrated that TREM2 protects against cerebral ischemia/reperfusion injury through the aspect of post-ischemic inflammatory response and neuronal apoptosis. Pharmacological targeting of TREM2 to suppress the inflammatory response may provide a new approach for developing therapeutic strategies in the treatment of ischemic stroke and other cerebrovascular diseases.
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Affiliation(s)
- Rong Wu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Xiangpen Li
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Pengfei Xu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Likui Huang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Jinping Cheng
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Xiaolong Huang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Jingru Jiang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Long-Jun Wu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA.,Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Yamei Tang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Number 107, Yan Jiang Xi Road, Guangzhou, Guangdong Province, 510120, China. .,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510120, China. .,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2nd Road, Guangzhou, 510080, China.
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Han J, Wang M, Ren M, Lou H. Contributions of triggering-receptor-expressed-on-myeloid-cells-2 to neurological diseases. Int J Neurosci 2016; 127:368-375. [PMID: 27871212 DOI: 10.1080/00207454.2016.1264072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Jie Han
- Department of Pharmacology, School of Medicine, Shandong University, Jinan 250012, China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute affiliated to Shandong University, Jinan 250012, China
| | - Miaomiao Wang
- Department of Hematology, Qilu Hospital, Shandong University, Jinan 250012, China
| | - Manru Ren
- Department of Pharmacology, School of Medicine, Shandong University, Jinan 250012, China
| | - Haiyan Lou
- Department of Pharmacology, School of Medicine, Shandong University, Jinan 250012, China
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Celarain N, Sánchez-Ruiz de Gordoa J, Zelaya MV, Roldán M, Larumbe R, Pulido L, Echavarri C, Mendioroz M. TREM2 upregulation correlates with 5-hydroxymethycytosine enrichment in Alzheimer's disease hippocampus. Clin Epigenetics 2016; 8:37. [PMID: 27051467 PMCID: PMC4820985 DOI: 10.1186/s13148-016-0202-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 03/22/2016] [Indexed: 01/09/2023] Open
Abstract
Background Recent genome-wide association studies revealed TREM2 rs75932628-T variant to be associated with Alzheimer’s disease (AD) and other neurodegenerative diseases. However, the role that TREM2 plays in sporadic AD is largely unknown. Our aim was to assess messenger RNA (mRNA) expression levels and DNA methylation profiling of TREM2 in human hippocampus in AD brain. We measured TREM2 mRNA levels in the hippocampus in a cohort of neuropathologically confirmed controls and pure AD cases showing no other protein deposits than β-amyloid and phosphorylated tau. We also examined DNA methylation levels in the TREM2 transcription start site (TSS)-associated region by bisulfite cloning sequencing and further extended the study by measuring 5-hydroxymethycytosine (5hmC) enrichment at different regions of TREM2 by 5hmC DNA immunoprecipitation combined with real-time qPCR. Results A 3.4-fold increase in TREM2 mRNA levels was observed in the hippocampus of AD cases compared to controls (p = 1.1E-05). Interestingly, TREM2 methylation was higher in AD cases compared to controls (76.2 % ± 15.5 versus 57.9 % ± 17.1; p = 0.0016). Moreover, TREM2 mRNA levels in the AD hippocampus correlated with enrichment in 5hmC at the TREM2 gene body (r = 0.771; p = 0.005). Conclusions TREM2 mRNA levels are increased in the human hippocampus in AD cases compared to controls. DNA methylation, and particularly 5hmC, may be involved in regulating TREM2 mRNA expression in the AD brain. Further studies are guaranteed to investigate in depth the role of 5hmC in AD and other neurodegenerative disorders. Electronic supplementary material The online version of this article (doi:10.1186/s13148-016-0202-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Naiara Celarain
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain
| | - Javier Sánchez-Ruiz de Gordoa
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain ; Department of Neurology, Complejo Hospitalario de Navarra, Pamplona, Navarra 31008 Spain ; Present address: Clínica San Miguel, Pamplona, Navarra 31006 Spain
| | - María Victoria Zelaya
- Department of Pathology, Complejo Hospitalario de Navarra, Pamplona, Navarra 31008 Spain
| | - Miren Roldán
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain
| | - Rosa Larumbe
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain ; Department of Neurology, Complejo Hospitalario de Navarra, Pamplona, Navarra 31008 Spain
| | - Laura Pulido
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain ; Department of Neurology, Complejo Hospitalario de Navarra, Pamplona, Navarra 31008 Spain ; Present address: Clínica San Miguel, Pamplona, Navarra 31006 Spain
| | - Carmen Echavarri
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain ; Hospital Psicogeriátrico Josefina Arregui, Alsasua, Navarra 31800 Spain
| | - Maite Mendioroz
- Neuroepigenetics Laboratory, Navarrabiomed-Navarra Institute for Health Research (IdiSNA), c/ Irunlarrea, Pamplona, Navarra 31008 Spain ; Department of Neurology, Complejo Hospitalario de Navarra, Pamplona, Navarra 31008 Spain
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Li C, Shah SZA, Zhao D, Yang L. Role of the Retromer Complex in Neurodegenerative Diseases. Front Aging Neurosci 2016; 8:42. [PMID: 26973516 PMCID: PMC4772447 DOI: 10.3389/fnagi.2016.00042] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/15/2016] [Indexed: 11/13/2022] Open
Abstract
The retromer complex is a protein complex that plays a central role in endosomal trafficking. Retromer dysfunction has been linked to a growing number of neurological disorders. The process of intracellular trafficking and recycling is crucial for maintaining normal intracellular homeostasis, which is partly achieved through the activity of the retromer complex. The retromer complex plays a primary role in sorting endosomal cargo back to the cell surface for reuse, to the trans-Golgi network (TGN), or alternatively to specialized endomembrane compartments, in which the cargo is not subjected to lysosomal-mediated degradation. In most cases, the retromer acts as a core that interacts with associated proteins, including sorting nexin family member 27 (SNX27), members of the vacuolar protein sorting 10 (VPS10) receptor family, the major endosomal actin polymerization-promoting complex known as Wiskott-Aldrich syndrome protein and scar homolog (WASH), and other proteins. Some of the molecules carried by the retromer complex are risk factors for neurodegenerative diseases. Defects such as haplo-insufficiency or mutations in one or several units of the retromer complex lead to various pathologies. Here, we summarize the molecular architecture of the retromer complex and the roles of this system in intracellular trafficking related the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Chaosi Li
- National Animal Transmissible Spongiform Encephalopathy Laboratory, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University Beijing, China
| | - Syed Zahid Ali Shah
- National Animal Transmissible Spongiform Encephalopathy Laboratory, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University Beijing, China
| | - Deming Zhao
- National Animal Transmissible Spongiform Encephalopathy Laboratory, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University Beijing, China
| | - Lifeng Yang
- National Animal Transmissible Spongiform Encephalopathy Laboratory, Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University Beijing, China
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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.
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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.
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Huang M, Wang D, Xu Z, Xu Y, Xu X, Ma Y, Xia Z. Lack of genetic association between TREM2 and Alzheimer's disease in East Asian population: a systematic review and meta-analysis. Am J Alzheimers Dis Other Demen 2015; 30:541-6. [PMID: 25852195 PMCID: PMC10852690 DOI: 10.1177/1533317515577128] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Large-scale genome-wide association studies have identified TREM2 variants to be significantly associated with Alzheimer's disease (AD) in caucasian population. The goal of this systematic study and meta-analysis was to assess the association between Triggering receptor expressed on myeloid cells 2 (TREM2) variants and AD in East Asian population. METHODS In this study, literatures were searched in PubMed, MEDLINE, EMBASE, and the Cochrane library to screen citations from January 1990 to June 2014. Data analysis was done by using the Stata 12 software. RESULTS Twelve studies were considered for analysis. A total of 13 535 patients with AD and 22 976 healthy controls were studied. The results showed that rs75932628 variant was significantly associated with AD in caucasian population (P < .001, odds ratio ¼ 3.17, 95% confidence interval 2.45-4.09). However, the association was not found in East Asian population. CONCLUSION In our study, we found that TREM2 variant is likely not associated with AD in East Asian population.
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Affiliation(s)
- Man Huang
- Department of General Intensive Care Unit, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dejun Wang
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhijun Xu
- Department of General Intensive Care Unit, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yongshan Xu
- Department of General Intensive Care Unit, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoping Xu
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yuefeng Ma
- Department of General Intensive Care Unit, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zheng Xia
- Laboratory Animal Research Center, Zhejiang Chinese Medical University, Hangzhou, China
- Bomai MediTech Co, Ltd, Zhejiang University National Science Park, Hangzhou, China
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Chen X, Chen Y, Wei Q, Guo X, Cao B, Ou R, Zhao B, Shang HF. Assessment of TREM2 rs75932628 association with amyotrophic lateral sclerosis in a Chinese population. J Neurol Sci 2015; 355:193-5. [PMID: 26026943 DOI: 10.1016/j.jns.2015.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/21/2015] [Accepted: 05/08/2015] [Indexed: 02/05/2023]
Abstract
Although, rs75932628 in triggering receptor expressed on myeloid cells 2 (TREM2) was shown to increase the risk for Alzheimer's disease, there is no agreement on the association between this variant and the risk for amyotrophic lateral sclerosis (ALS). We conducted a large-sample study to investigate if this variant is associated with ALS in a Chinese population. A total of 868 sporadic ALS (SALS) and 869 healthy controls were included. All cases were genotyped for the single nucleotide polymorphisms (SNP) using Sequenom iPLEX Assay technology. The rs75932628-T variant of the TREM2 gene was not identified in SALS patients and controls. It is unlikely to play a role in the pathogenesis of ALS in Chinese patients with SALS.
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Affiliation(s)
- Xueping Chen
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yongping Chen
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qianqian Wei
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xiaoyan Guo
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Bei Cao
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ruwei Ou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Bi Zhao
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hui-Fang Shang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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Xing J, Titus AR, Humphrey MB. The TREM2-DAP12 signaling pathway in Nasu-Hakola disease: a molecular genetics perspective. ACTA ACUST UNITED AC 2015; 5:89-100. [PMID: 26478868 PMCID: PMC4605443 DOI: 10.2147/rrbc.s58057] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nasu–Hakola disease or polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL) is a rare recessively inherited disease that is associated with early dementia and bone cysts with fractures. Here, we review the genetic causes of PLOSL with loss-of-function mutations or deletions in one of two genes, TYROBP and TREM2, encoding for two proteins DNAX-activating protein 12 (DAP12) and triggering receptor expressed on myeloid cells-2 (TREM2). TREM2 and DAP12 form an immunoreceptor signaling complex that mediates myeloid cell, including microglia and osteoclasts, development, activation, and function. Functionally, TREM2-DAP12 mediates osteoclast multi-nucleation, migration, and resorption. In microglia, TREM2-DAP12 participates in recognition and apoptosis of neuronal debris and amyloid deposits. Review of the complex immunoregulatory roles of TREM2-DAP12 in the innate immune system, where it can both promote and inhibit pro-inflammatory responses, is given. Little is known about the function of TREM2-DAP12 in normal brain homeostasis or in pathological central nervous system diseases. Based on the state of the field, genetic testing now aids in diagnosis of PLOSL, but therapeutics and interventions are still under development.
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Affiliation(s)
- Junjie Xing
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA ; Department of Microbiology and immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Amanda R Titus
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Mary Beth Humphrey
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA ; Department of Microbiology and immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA ; Department of veteran's Affairs, Oklahoma City, OK, USA
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Yaghmoor F, Noorsaeed A, Alsaggaf S, Aljohani W, Scholtzova H, Boutajangout A, Wisniewski T. The Role of TREM2 in Alzheimer's Disease and Other Neurological Disorders. JOURNAL OF ALZHEIMER'S DISEASE & PARKINSONISM 2014; 4:160. [PMID: 25664220 PMCID: PMC4317331 DOI: 10.4172/2161-0460.1000160] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of dementia worldwide. Late-onset AD (LOAD), is the most common form of Alzheimer's disease, representing about >95% of cases and early-onset AD represents <5% of cases. Several risk factors have been discovered that are associated with AD, with advancing age being the most prominent. Other environmental risk factors include diabetes mellitus, level of physical activity, educational status, hypertension and head injury. The most well known genetic risk factor for LOAD is inheritance of the apolipoprotein (apo) E4 allele. Recently, rare variants of TREM2 have been reported as a significant risk factor for LOAD, comparable to inheritance of apoE4. In this review we will focus on the role(s) of TREM2 in AD as well as in other neurodegenerative disorders.
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Affiliation(s)
- Faris Yaghmoor
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Ahmed Noorsaeed
- Pathology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Samar Alsaggaf
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Waleed Aljohani
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Henrieta Scholtzova
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
| | - Allal Boutajangout
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Psychiatry, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Physiology and Neuroscience, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY10016, USA
- King Abdulaziz University, School of Medicine, Jeddah, Saudi Arabia
| | - Thomas Wisniewski
- Departments of Neurology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Pathology, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
- Psychiatry, New York University School of Medicine, Alexandria ERSP, 450 East 29th Street, New York, NY 10016, USA
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What happens to microglial TREM2 in Alzheimer's disease: Immunoregulatory turned into immunopathogenic? Neuroscience 2014; 302:138-50. [PMID: 25281879 DOI: 10.1016/j.neuroscience.2014.09.050] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/23/2014] [Accepted: 09/23/2014] [Indexed: 12/12/2022]
Abstract
Microglia play major roles in initiation, coordination and execution of innate immunity in the brain. In the adult brain, these include maintenance of homeostasis, neuron and tissue repair, and eliminating infectious agents, apoptotic cells, and misfolded proteins. Some of these activities are accompanied by inflammatory reactions; and others are performed with no inflammatory effects. Under normal conditions, triggering receptor expressed on myeloid cells 2 (TREM2) belongs to the second category. It pairs with the adaptor protein DNAX-activating protein of 12kDa (DAP12) to induce phagocytosis of apoptotic neurons without inflammatory responses, and to regulate Toll-like receptor-mediated inflammatory responses, and microglial activation. Although ligands for TREM2 are largely unknown, the mitochondrial heat shock protein 60, expressed on cell surface of apoptotic neurons, is a specific ligand that activates TREM2-mediated phagocytosis by microglia. TREM2 also phagocytoses amyloid beta peptide in cultured cells. Several TREM2 mutations have been identified recently that increase the risk of Alzheimer's disease, Frontotemporal dementia, Parkinson's disease, and amyotrophic lateral sclerosis. Some of these mutations cause impaired proteolysis of full-length TREM2 at the plasma membrane to different degrees. The defects in the intramembrane cleavage result in dysfunction of phagocytosis signaling. The association of TREM2 mutations with neurodegenerative disease also calls for the understanding of the biology and pathological role of non-mutated TREM2 on human brains and microglia. This review provides a summary of current literature in TREM2 and DAP12 from several aspects, and proposes a theory that loss of TREM2 functions might contribute to the immunopathogenic role of microglia in Alzheimer's disease.
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Bhattacharjee S, Zhao Y, Lukiw WJ. Deficits in the miRNA-34a-regulated endogenous TREM2 phagocytosis sensor-receptor in Alzheimer's disease (AD); an update. Front Aging Neurosci 2014; 6:116. [PMID: 24987367 PMCID: PMC4060025 DOI: 10.3389/fnagi.2014.00116] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 05/24/2014] [Indexed: 01/22/2023] Open
Affiliation(s)
- Surjyadipta Bhattacharjee
- Departments of Neurology, Neuroscience and Ophthalmology, Louisiana State University Neuroscience Center and Health Sciences Center New Orleans, LA, USA
| | - Yuhai Zhao
- Departments of Neurology, Neuroscience and Ophthalmology, Louisiana State University Neuroscience Center and Health Sciences Center New Orleans, LA, USA
| | - Walter J Lukiw
- Departments of Neurology, Neuroscience and Ophthalmology, Louisiana State University Neuroscience Center and Health Sciences Center New Orleans, LA, USA
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