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Zhu M, Zhang G, Meng L, Xiao T, Fang X, Zhang Z. Physiological and pathological functions of TMEM106B in neurodegenerative diseases. Cell Mol Life Sci 2024; 81:209. [PMID: 38710967 DOI: 10.1007/s00018-024-05241-z] [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: 02/19/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 05/08/2024]
Abstract
As an integral lysosomal transmembrane protein, transmembrane protein 106B (TMEM106B) regulates several aspects of lysosomal function and is associated with neurodegenerative diseases. The TMEM106B gene mutations lead to lysosomal dysfunction and accelerate the pathological progression of Neurodegenerative diseases. Yet, the precise mechanism of TMEM106B in Neurodegenerative diseases remains unclear. Recently, different research teams discovered that TMEM106B is an amyloid protein and the C-terminal domain of TMEM106B forms amyloid fibrils in various Neurodegenerative diseases and normally elderly individuals. In this review, we discussed the physiological functions of TMEM106B. We also included TMEM106B gene mutations that cause neurodegenerative diseases. Finally, we summarized the identification and cryo-electronic microscopic structure of TMEM106B fibrils, and discussed the promising therapeutic strategies aimed at TMEM106B fibrils and the future directions for TMEM106B research in neurodegenerative diseases.
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Affiliation(s)
- Min Zhu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Guoxin Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Lanxia Meng
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Tingting Xiao
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
| | - Xin Fang
- Department of Neurology, the First Affiliated Hospital of Nanchang University, Nanchang, 330000, China.
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
- TaiKang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430000, China.
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2
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Edwards GA, Wood CA, He Y, Nguyen Q, Kim PJ, Gomez-Gutierrez R, Park KW, Xu Y, Zurhellen C, Al-Ramahi I, Jankowsky JL. TMEM106B coding variant is protective and deletion detrimental in a mouse model of tauopathy. Acta Neuropathol 2024; 147:61. [PMID: 38526616 DOI: 10.1007/s00401-024-02701-5] [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: 10/02/2023] [Revised: 01/07/2024] [Accepted: 01/31/2024] [Indexed: 03/27/2024]
Abstract
TMEM106B is a risk modifier of multiple neurological conditions, where a single coding variant and multiple non-coding SNPs influence the balance between susceptibility and resilience. Two key questions that emerge from past work are whether the lone T185S coding variant contributes to protection, and if the presence of TMEM106B is helpful or harmful in the context of disease. Here, we address both questions while expanding the scope of TMEM106B study from TDP-43 to models of tauopathy. We generated knockout mice with constitutive deletion of TMEM106B, alongside knock-in mice encoding the T186S knock-in mutation (equivalent to the human T185S variant), and crossed both with a P301S transgenic tau model to study how these manipulations impacted disease phenotypes. We found that TMEM106B deletion accelerated cognitive decline, hind limb paralysis, tau pathology, and neurodegeneration. TMEM106B deletion also increased transcriptional correlation with human AD and the functional pathways enriched in KO:tau mice aligned with those of AD. In contrast, the coding variant protected against tau-associated cognitive decline, synaptic impairment, neurodegeneration, and paralysis without affecting tau pathology. Our findings reveal that TMEM106B is a critical safeguard against tau aggregation, and that loss of this protein has a profound effect on sequelae of tauopathy. Our study further demonstrates that the coding variant is functionally relevant and contributes to neuroprotection downstream of tau pathology to preserve cognitive function.
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Affiliation(s)
- George A Edwards
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Caleb A Wood
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Yang He
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Quynh Nguyen
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Peter J Kim
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Ruben Gomez-Gutierrez
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Kyung-Won Park
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA
| | - Yong Xu
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Cody Zurhellen
- NeuroScience Associates, 10915 Lake Ridge Drive, Knoxville, TN, 37934, USA
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Joanna L Jankowsky
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Mail Stop BCM295, Houston, TX, 77030, USA.
- Department of Neurology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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3
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Feng T, Du H, Yang C, Wang Y, Hu F. Loss of TMEM106B exacerbates Tau pathology and neurodegeneration in PS19 mice. Acta Neuropathol 2024; 147:62. [PMID: 38526799 DOI: 10.1007/s00401-024-02702-4] [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: 10/02/2023] [Revised: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 03/27/2024]
Abstract
TMEM106B, a gene encoding a lysosome membrane protein, is tightly associated with brain aging, hypomyelinating leukodystrophy, and multiple neurodegenerative diseases, including frontotemporal lobar degeneration with TDP-43 aggregates (FTLD-TDP). Recently, TMEM106B polymorphisms have been associated with tauopathy in chronic traumatic encephalopathy (CTE) and FTLD-TDP patients. However, how TMEM106B influences Tau pathology and its associated neurodegeneration, is unclear. Here we show that loss of TMEM106B enhances the accumulation of pathological Tau, especially in the neuronal soma in the hippocampus, resulting in severe neuronal loss in the PS19 Tau transgenic mice. Moreover, Tmem106b-/- PS19 mice develop significantly increased abnormalities in the neuronal cytoskeleton, autophagy-lysosome activities, as well as glial activation, compared with PS19 and Tmem106b-/- mice. Together, our findings demonstrate that loss of TMEM106B drastically exacerbates Tau pathology and its associated disease phenotypes, and provide new insights into the roles of TMEM106B in neurodegenerative diseases.
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Affiliation(s)
- Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Huan Du
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Cha Yang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Ya Wang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA.
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Feng T, Du H, Hu F. Loss of TMEM106B exacerbates Tau pathology and neurodegeneration in PS19 mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566707. [PMID: 38014238 PMCID: PMC10680640 DOI: 10.1101/2023.11.11.566707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
TMEM106B, a gene encoding a lysosome membrane protein, is tightly associated with brain aging, hypomyelinating leukodystrophy, and multiple neurodegenerative diseases, including frontotemporal lobar degeneration with TDP-43 aggregates (FTLD-TDP). Recently, TMEM106B polymorphisms have been associated with tauopathy in chronic traumatic encephalopathy (CTE) and FTLD-TDP patients. However, how TMEM106B influences Tau pathology and its associated neurodegeneration, is unclear. Here we show that loss of TMEM106B enhances the accumulation of pathological Tau, especially in the neuronal soma in the hippocampus, resulting in severe neuronal loss in the PS19 Tau transgenic mice. Moreover, Tmem106b-/- PS19 mice develop significantly increased disruption of the neuronal cytoskeleton, autophagy-lysosomal function, and lysosomal trafficking along the axon as well as enhanced gliosis compared with PS19 and Tmem106b-/- mice. Together, our findings demonstrate that loss of TMEM106B drastically exacerbates Tau pathology and its associated disease phenotypes, and provide new insights into the roles of TMEM106B in neurodegenerative diseases.
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Affiliation(s)
- Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Huan Du
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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Nguyen Q, Wood CA, Kim PJ, Jankowsky JL. The TMEM106B T186S coding variant increases neurite arborization and synaptic density in primary hippocampal neurons. Front Neurosci 2023; 17:1275959. [PMID: 37901434 PMCID: PMC10603297 DOI: 10.3389/fnins.2023.1275959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/19/2023] [Indexed: 10/31/2023] Open
Abstract
The lysosomal protein TMEM106B was identified as a risk modifier of multiple dementias including frontotemporal dementia and Alzheimer's disease. The gene comes in two major haplotypes, one associated with disease risk, and by comparison, the other with resilience. Only one coding polymorphism distinguishes the two alleles, a threonine-to-serine substitution at residue 185 (186 in mouse), that is inherited in disequilibrium with multiple non-coding variants. Transcriptional studies suggest synaptic, neuronal, and cognitive preservation in human subjects with the protective haplotype, while murine in vitro studies reveal dramatic effects of TMEM106B deletion on neuronal development. Despite this foundation, the field has not yet resolved whether coding variant is biologically meaningful, and if so, whether it has any specific effect on neuronal phenotypes. Here we studied how loss of TMEM106B or expression of the lone coding variant in isolation affected transcriptional signatures in the mature brain and neuronal structure during development in primary neurons. Homozygous expression of the TMEM106B T186S variant in knock-in mice increased cortical expression of genes associated with excitatory synaptic function and axon outgrowth, and promoted neurite branching, dendritic spine density, and synaptic density in primary hippocampal neurons. In contrast, constitutive TMEM106B deletion affected transcriptional signatures of myelination without altering neuronal development in vitro. Our findings show that the T186S variant is functionally relevant and may contribute to disease resilience during neurodevelopment.
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Affiliation(s)
- Quynh Nguyen
- Departments of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Caleb A. Wood
- Departments of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Peter J. Kim
- Departments of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Joanna L. Jankowsky
- Departments of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- Neurology, Neurosurgery, and Molecular and Cellular Biology, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, United States
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Lee JY, Harney DJ, Teo JD, Kwok JB, Sutherland GT, Larance M, Don AS. The major TMEM106B dementia risk allele affects TMEM106B protein levels, fibril formation, and myelin lipid homeostasis in the ageing human hippocampus. Mol Neurodegener 2023; 18:63. [PMID: 37726834 PMCID: PMC10510131 DOI: 10.1186/s13024-023-00650-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 08/17/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND The risk for dementia increases exponentially from the seventh decade of life. Identifying and understanding the biochemical changes that sensitize the ageing brain to neurodegeneration will provide new opportunities for dementia prevention and treatment. This study aimed to determine how ageing and major genetic risk factors for dementia affect the hippocampal proteome and lipidome of neurologically-normal humans over the age of 65. The hippocampus was chosen as it is highly susceptible to atrophy with ageing and in several neurodegenerative diseases. METHODS Mass spectrometry-based proteomic and lipidomic analysis of CA1 hippocampus samples from 74 neurologically normal human donors, aged 66-104, was used in combination with multiple regression models and gene set enrichment analysis to identify age-dependent changes in the proteome and lipidome. ANOVA was used to test the effect of major dementia risk alleles in the TMEM106B and APOE genes on the hippocampal proteome and lipidome, adjusting for age, gender, and post-mortem interval. Fibrillar C-terminal TMEM106B fragments were isolated using sarkosyl fractionation and quantified by immunoblotting. RESULTS Forty proteins were associated with age at false discovery rate-corrected P < 0.05, including proteins that regulate cell adhesion, the cytoskeleton, amino acid and lipid metabolism, and ribosomal subunits. TMEM106B, a regulator of lysosomal and oligodendrocyte function, was regulated with greatest effect size. The increase in TMEM106B levels with ageing was specific to carriers of the rs1990622-A allele in the TMEM106B gene that increases risk for frontotemporal dementia, Alzheimer's disease, Parkinson's disease, and hippocampal sclerosis with ageing. Rs1990622-A was also associated with higher TMEM106B fibril content. Hippocampal lipids were not significantly affected by APOE genotype, however levels of myelin-enriched sulfatides and hexosylceramides were significantly lower, and polyunsaturated phospholipids were higher, in rs1990622-A carriers after controlling for APOE genotype. CONCLUSIONS Our study demonstrates that TMEM106B protein abundance is increased with brain ageing in humans, establishes that dementia risk allele rs1990622-A predisposes to TMEM106B fibril formation in the hippocampus, and provides the first evidence that rs1990622-A affects brain lipid homeostasis, particularly myelin lipids. Our data suggests that TMEM106B is one of a growing list of major dementia risk genes that affect glial lipid metabolism.
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Affiliation(s)
- Jun Yup Lee
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
| | - Dylan J Harney
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
| | - Jonathan D Teo
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
| | - John B Kwok
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
- Brain and Mind Centre, The University of Sydney, Camperdown, NSW, 2006, Australia
| | - Greg T Sutherland
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
| | - Mark Larance
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia
- School of Medical Sciences, Camperdown, NSW, 2006, Australia
| | - Anthony S Don
- Charles Perkins Centre, Camperdown, NSW, 2006, Australia.
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Takahashi H, Perez-Canamas A, Ye H, Han X, Strittmatter SM. Lysosomal TMEM106B interacts with galactosylceramidase to regulate myelin lipid metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557804. [PMID: 37745346 PMCID: PMC10515910 DOI: 10.1101/2023.09.14.557804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
TMEM106B is an endolysosomal transmembrane protein not only associated with multiple neurological disorders including frontotemporal dementia, Alzheimer's disease, and hypomyelinating leukodystrophy but also potentially involved in COVID-19. Additionally, recent studies have identified amyloid fibrils of C-terminal TMEM106B in both aged healthy and neurodegenerative brains. However, so far little is known about physiological functions of TMEM106B in the endolysosome and how TMEM106B is involved in a wide range of human conditions at molecular levels. Here, we performed lipidomic analysis of the brain of TMEM106B-deficient mice. We found that TMEM106B deficiency significantly decreases levels of two major classes of myelin lipids, galactosylceramide and its sulfated derivative sulfatide. Subsequent co-immunoprecipitation assay showed that TMEM106B physically interacts with galactosylceramidase. We also found that galactosyceramidase activity was significantly increased in TMEM106B-deficient brains. Thus, our results reveal a novel function of TMEM106B interacting with galactosyceramidase to regulate myelin lipid metabolism and have implications for TMEM106B-associated diseases.
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Affiliation(s)
- Hideyuki Takahashi
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Azucena Perez-Canamas
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Hongping Ye
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
- Department of Medicine, University of Texas Health Science Center At San Antonio, San Antonio, TX, 78229, USA
| | - Stephen M. Strittmatter
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
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Torii T, Yamauchi J. Molecular Pathogenic Mechanisms of Hypomyelinating Leukodystrophies (HLDs). Neurol Int 2023; 15:1155-1173. [PMID: 37755363 PMCID: PMC10538087 DOI: 10.3390/neurolint15030072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/29/2023] [Accepted: 09/06/2023] [Indexed: 09/28/2023] Open
Abstract
Hypomyelinating leukodystrophies (HLDs) represent a group of congenital rare diseases for which the responsible genes have been identified in recent studies. In this review, we briefly describe the genetic/molecular mechanisms underlying the pathogenesis of HLD and the normal cellular functions of the related genes and proteins. An increasing number of studies have reported genetic mutations that cause protein misfolding, protein dysfunction, and/or mislocalization associated with HLD. Insight into the mechanisms of these pathways can provide new findings for the clinical treatments of HLD.
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Affiliation(s)
- Tomohiro Torii
- Laboratory of Molecular Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji 192-0392, Japan
- Laboratory of Ion Channel Pathophysiology, Graduate School of Brain Science, Doshisha University, Kyotanabe-shi 610-0394, Japan
- Center for Research in Neurodegenerative Disease, Doshisha University, Kyotanabe-shi 610-0394, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji 192-0392, Japan
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya-ku 157-8535, Japan
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Jiao HS, Yuan P, Yu JT. TMEM106B aggregation in neurodegenerative diseases: linking genetics to function. Mol Neurodegener 2023; 18:54. [PMID: 37563705 PMCID: PMC10413548 DOI: 10.1186/s13024-023-00644-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023] Open
Abstract
BACKGROUND Mutations of the gene TMEM106B are risk factors for diverse neurodegenerative diseases. Previous understanding of the underlying mechanism focused on the impairment of lysosome biogenesis caused by TMEM106B loss-of-function. However, mutations in TMEM106B increase its expression level, thus the molecular process linking these mutations to the apparent disruption in TMEM106B function remains mysterious. MAIN BODY Recent new studies reported that TMEM106B proteins form intracellular amyloid filaments which universally exist in various neurodegenerative diseases, sometimes being the dominant form of protein aggregation. In light of these new findings, in this review we systematically examined previous efforts in understanding the function of TMEM106B in physiological and pathological conditions. We propose that TMEM106B aggregations could recruit normal TMEM106B proteins and interfere with their function. CONCLUSIONS TMEM106B mutations could lead to lysosome dysfunction by promoting the aggregation of TMEM106B and reducing these aggregations may restore lysosomal function, providing a potential therapeutic target for various neurodegenerative diseases.
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Affiliation(s)
- Hai-Shan Jiao
- Department of Neurology and National Center for Neurological Disorders, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200040, China
| | - Peng Yuan
- Department of Rehabilitation Medicine, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Huashan Hospital, Institute for Translational Brain Research, Fudan University, Shanghai, China.
| | - Jin-Tai Yu
- Department of Neurology and National Center for Neurological Disorders, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200040, China.
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Baggen J, Jacquemyn M, Persoons L, Vanstreels E, Pye VE, Wrobel AG, Calvaresi V, Martin SR, Roustan C, Cronin NB, Reading E, Thibaut HJ, Vercruysse T, Maes P, De Smet F, Yee A, Nivitchanyong T, Roell M, Franco-Hernandez N, Rhinn H, Mamchak AA, Ah Young-Chapon M, Brown E, Cherepanov P, Daelemans D. TMEM106B is a receptor mediating ACE2-independent SARS-CoV-2 cell entry. Cell 2023; 186:3427-3442.e22. [PMID: 37421949 PMCID: PMC10409496 DOI: 10.1016/j.cell.2023.06.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 04/24/2023] [Accepted: 06/08/2023] [Indexed: 07/10/2023]
Abstract
SARS-CoV-2 is associated with broad tissue tropism, a characteristic often determined by the availability of entry receptors on host cells. Here, we show that TMEM106B, a lysosomal transmembrane protein, can serve as an alternative receptor for SARS-CoV-2 entry into angiotensin-converting enzyme 2 (ACE2)-negative cells. Spike substitution E484D increased TMEM106B binding, thereby enhancing TMEM106B-mediated entry. TMEM106B-specific monoclonal antibodies blocked SARS-CoV-2 infection, demonstrating a role of TMEM106B in viral entry. Using X-ray crystallography, cryogenic electron microscopy (cryo-EM), and hydrogen-deuterium exchange mass spectrometry (HDX-MS), we show that the luminal domain (LD) of TMEM106B engages the receptor-binding motif of SARS-CoV-2 spike. Finally, we show that TMEM106B promotes spike-mediated syncytium formation, suggesting a role of TMEM106B in viral fusion. Together, our findings identify an ACE2-independent SARS-CoV-2 infection mechanism that involves cooperative interactions with the receptors heparan sulfate and TMEM106B.
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Affiliation(s)
- Jim Baggen
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium.
| | - Maarten Jacquemyn
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium
| | - Leentje Persoons
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium
| | - Els Vanstreels
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium
| | - Valerie E Pye
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London NW1 1AT, UK
| | - Antoni G Wrobel
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London NW1 1AT, UK
| | - Valeria Calvaresi
- Department of Chemistry, Britannia House, 7 Trinity Street, King's College London, London SE1 1DB, UK
| | - Stephen R Martin
- Structural Biology of Disease Processes Laboratory, Francis Crick Institute, London NW1 1AT, UK
| | - Chloë Roustan
- Structural Biology Science Technology Platform, Francis Crick Institute, London NW1 1AT, UK
| | - Nora B Cronin
- LonCEM Facility, Francis Crick Institute, London NW1 1AT, UK
| | - Eamonn Reading
- Department of Chemistry, Britannia House, 7 Trinity Street, King's College London, London SE1 1DB, UK
| | - Hendrik Jan Thibaut
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Translational Platform Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium
| | - Thomas Vercruysse
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Translational Platform Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium
| | - Piet Maes
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Clinical and Epidemiological Virology, Rega Institute, Leuven 3000, Belgium
| | - Frederik De Smet
- KU Leuven Department of Imaging and Pathology, Laboratory for Precision Cancer Medicine, Translational Cell and Tissue Research Unit, Leuven 3000, Belgium
| | - Angie Yee
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | - Toey Nivitchanyong
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | - Marina Roell
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | | | - Herve Rhinn
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | - Alusha Andre Mamchak
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | | | - Eric Brown
- Alector LLC, 131 Oyster Point Blvd. Suite 600, South San Francisco, CA 94080, USA
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA Laboratory, Francis Crick Institute, London NW1 1AT, UK; Department of Infectious Disease, Section of Virology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK.
| | - Dirk Daelemans
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven 3000, Belgium.
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Xing S, Zheng X, Yan H, Mo Y, Duan R, Chen Z, Wang K, Gao K, Chen T, Zhao S, Wang J, Chen L. Superresolution live-cell imaging reveals that the localization of TMEM106B to filopodia in oligodendrocytes is compromised by the hypomyelination-related D252N mutation. SCIENCE CHINA. LIFE SCIENCES 2023; 66:1858-1868. [PMID: 37129766 DOI: 10.1007/s11427-022-2290-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/30/2023] [Indexed: 05/03/2023]
Abstract
Hypomyelination leukodystrophies constitute a group of heritable white matter disorders exhibiting defective myelin development. Initially identified as a lysosomal protein, the TMEM106B D252N mutant has recently been associated with hypomyelination. However, how lysosomal TMEM106B facilitates myelination and how the D252N mutation disrupts that process are poorly understood. We used superresolution Hessian structured illumination microscopy (Hessian-SIM) and spinning disc-confocal structured illumination microscopy (SD-SIM) to find that the wild-type TMEM106B protein is targeted to the plasma membrane, filopodia, and lysosomes in human oligodendrocytes. The D252N mutation reduces the size of lysosomes in oligodendrocytes and compromises lysosome changes upon starvation stress. Most importantly, we detected reductions in the length and number of filopodia in cells expressing the D252N mutant. PLP1 is the most abundant myelin protein that almost entirely colocalizes with TMEM106B, and coexpressing PLP1 with the D252N mutant readily rescues the lysosome and filopodia phenotypes of cells. Therefore, interactions between TMEM106B and PLP1 on the plasma membrane are essential for filopodia formation and myelination in oligodendrocytes, which may be sustained by the delivery of these proteins from lysosomes via exocytosis.
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Affiliation(s)
- Shijia Xing
- National Biomedical Imaging Center, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China
| | - Xiaolu Zheng
- National Biomedical Imaging Center, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China
| | - Huifang Yan
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yanquan Mo
- National Biomedical Imaging Center, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China
| | - Ruoyu Duan
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
- National Center for Children's Health, Department of Neurology, Beijing Children's Hospital, Capital Medical University, Beijing, 100045, China
| | - Zhixing Chen
- National Biomedical Imaging Center, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China
| | - Kunhao Wang
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Tongsheng Chen
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Shiqun Zhao
- National Biomedical Imaging Center, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China.
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
| | - Liangyi Chen
- National Biomedical Imaging Center, State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing, 100871, China.
- PKU-IDG/McGovern Institute for Brain Research, Beijing, 100871, China.
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12
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Feng T, Minevich G, Liu P, Qin HX, Wozniak G, Pham J, Pham K, Korgaonkar A, Kurnellas M, Defranoux NA, Long H, Mitra A, Hu F. AAV- GRN partially corrects motor deficits and ALS/FTLD-related pathology in Tmem106b-/-Grn-/- mice. iScience 2023; 26:107247. [PMID: 37519899 PMCID: PMC10371829 DOI: 10.1016/j.isci.2023.107247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/18/2023] [Accepted: 06/26/2023] [Indexed: 08/01/2023] Open
Abstract
Loss of function of progranulin (PGRN), encoded by the granulin (GRN) gene, is implicated in several neurodegenerative diseases. Several therapeutics to boost PGRN levels are currently in clinical trials. However, it is difficult to test the efficacy of PGRN-enhancing drugs in mouse models due to the mild phenotypes of Grn-/- mice. Recently, mice deficient in both PGRN and TMEM106B were shown to develop severe motor deficits and pathology. Here, we show that intracerebral ventricle injection of PGRN-expressing AAV1/9 viruses partially rescues motor deficits, neuronal loss, glial activation, and lysosomal abnormalities in Tmem106b-/-Grn-/- mice. Widespread expression of PGRN is detected in both the brain and spinal cord for both AAV subtypes. However, AAV9 but not AAV1-mediated expression of PGRN results in high levels of PGRN in the serum. Together, these data support using the Tmem106b-/-Grn-/- mouse strain as a robust mouse model to determine the efficacy of PGRN-elevating therapeutics.
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Affiliation(s)
- Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | | | - Pengan Liu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Henry Xin Qin
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | | | - Jenny Pham
- Alector Inc, South San Francisco, CA 94080, USA
| | - Khanh Pham
- Alector Inc, South San Francisco, CA 94080, USA
| | | | | | | | - Hua Long
- Alector Inc, South San Francisco, CA 94080, USA
| | | | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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13
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Shafit-Zagardo B, Sidoli S, Goldman JE, DuBois JC, Corboy JR, Strittmatter SM, Guzik H, Edema U, Arackal AG, Botbol YM, Merheb E, Nagra RM, Graff S. TMEM106B Puncta Is Increased in Multiple Sclerosis Plaques, and Reduced Protein in Mice Results in Delayed Lipid Clearance Following CNS Injury. Cells 2023; 12:1734. [PMID: 37443768 PMCID: PMC10340176 DOI: 10.3390/cells12131734] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
During inflammatory, demyelinating diseases such as multiple sclerosis (MS), inflammation and axonal damage are prevalent early in the course. Axonal damage includes swelling, defects in transport, and failure to clear damaged intracellular proteins, all of which affect recovery and compromise neuronal integrity. The clearance of damaged cell components is important to maintain normal turnover and restore homeostasis. In this study, we used mass spectrometry to identify insoluble proteins within high-speed/mercaptoethanol/sarcosyl-insoluble pellets from purified white matter plaques isolated from the brains of individuals with relapsing-remitting MS (RRMS). We determined that the transmembrane protein 106B (TMEM106B), normally lysosome-associated, is insoluble in RRMS plaques relative to normal-appearing white matter from individuals with Alzheimer's disease and non-neurologic controls. Relative to wild-type mice, hypomorphic mice with a reduction in TMEM106B have increased axonal damage and lipid droplet accumulation in the spinal cord following myelin-oligodendrocyte-glycoprotein-induced experimental autoimmune encephalomyelitis. Additionally, the corpora callosa from cuprizone-challenged hypomorphic mice fail to clear lipid droplets efficiently during remyelination, suggesting that when TMEM106B is compromised, protein and lipid clearance by the lysosome is delayed. As TMEM106B contains putative lipid- and LC3-binding sites, further exploration of these sites is warranted.
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Affiliation(s)
| | - Simone Sidoli
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Juwen C DuBois
- Department of Pathology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - John R Corboy
- Rocky Mountain MS Brain Bank, Department of Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Stephen M Strittmatter
- Departments of Neurology and Neuroscience, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT 06510, USA
| | - Hillary Guzik
- Analytic Imaging Facility, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Ukuemi Edema
- Department of Anatomic and Clinical Pathology, Montefiore Medical Center, Bronx, NY 10467, USA
| | - Anita G Arackal
- Department of Anatomic and Clinical Pathology, Montefiore Medical Center, Bronx, NY 10467, USA
| | - Yair M Botbol
- Department of Pathology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Emilio Merheb
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Rashed M Nagra
- UCLA Brain Bank, VA Healthcare System, Los Angeles, CA 90073, USA
| | - Sarah Graff
- Department of Biochemistry, Albert Einstein College of Medicine, New York, NY 10461, USA
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14
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Zhang T, Pang W, Feng T, Guo J, Wu K, Nunez Santos M, Arthanarisami A, Nana AL, Nguyen Q, Kim PJ, Jankowsky JL, Seeley WW, Hu F. TMEM106B regulates microglial proliferation and survival in response to demyelination. SCIENCE ADVANCES 2023; 9:eadd2676. [PMID: 37146150 PMCID: PMC10162677 DOI: 10.1126/sciadv.add2676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 04/05/2023] [Indexed: 05/07/2023]
Abstract
TMEM106B, a lysosomal transmembrane protein, has been closely associated with brain health. Recently, an intriguing link between TMEM106B and brain inflammation has been discovered, but how TMEM106B regulates inflammation is unknown. Here, we report that TMEM106B deficiency in mice leads to reduced microglia proliferation and activation and increased microglial apoptosis in response to demyelination. We also found an increase in lysosomal pH and a decrease in lysosomal enzyme activities in TMEM106B-deficient microglia. Furthermore, TMEM106B loss results in a significant decrease in the protein levels of TREM2, an innate immune receptor essential for microglia survival and activation. Specific ablation of TMEM106B in microglia results in similar microglial phenotypes and myelination defects in mice, supporting the idea that microglial TMEM106B is critical for proper microglial activities and myelination. Moreover, the TMEM106B risk allele is associated with myelin loss and decreased microglial numbers in humans. Collectively, our study unveils a previously unknown role of TMEM106B in promoting microglial functionality during demyelination.
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Affiliation(s)
- Tingting Zhang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Weilun Pang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jennifer Guo
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Kenton Wu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Mariela Nunez Santos
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Akshayakeerthi Arthanarisami
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Alissa L. Nana
- Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Quynh Nguyen
- Department of Neuroscience, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Peter J. Kim
- Department of Neuroscience, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Joanna L. Jankowsky
- Department of Neuroscience, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
- Departments of Molecular and Cellular Biology, Neurology, and Neurosurgery, Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - William W. Seeley
- Department of Neurology, University of California, San Francisco, CA 94158, USA
- Department of Pathology, University of California, San Francisco, CA 94158, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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15
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Zhang T, Feng T, Wu K, Guo J, Nana AL, Yang G, Seeley WW, Hu F. Progranulin deficiency results in sex-dependent alterations in microglia in response to demyelination. Acta Neuropathol 2023:10.1007/s00401-023-02578-w. [PMID: 37120788 PMCID: PMC10375542 DOI: 10.1007/s00401-023-02578-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/01/2023]
Abstract
Heterozygous mutations in the granulin (GRN) gene, resulting in the haploinsufficiency of the progranulin (PGRN) protein, is a leading cause of frontotemporal lobar degeneration (FTLD). Complete loss of the PGRN protein causes neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disorder. Polymorphisms in the GRN gene have also been associated with several other neurodegenerative diseases, including Alzheimer's disease (AD), and Parkinson's disease (PD). PGRN deficiency has been shown to cause myelination defects previously, but how PGRN regulates myelination is unknown. Here, we report that PGRN deficiency leads to a sex-dependent myelination defect with male mice showing more severe demyelination in response to cuprizone treatment. This is accompanied by exacerbated microglial proliferation and activation in the male PGRN-deficient mice. Interestingly, both male and female PGRN-deficient mice show sustained microglial activation after cuprizone removal and a defect in remyelination. Specific ablation of PGRN in microglia results in similar sex-dependent phenotypes, confirming a microglial function of PGRN. Lipid droplets accumulate in microglia specifically in male PGRN-deficient mice. RNA-seq analysis and mitochondrial function assays reveal key differences in oxidative phosphorylation in male versus female microglia under PGRN deficiency. A significant decrease in myelination and accumulation of myelin debris and lipid droplets in microglia were found in the corpus callosum regions of FTLD patients with GRN mutations. Taken together, our data support that PGRN deficiency leads to sex-dependent alterations in microglia with subsequent myelination defects.
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Affiliation(s)
- Tingting Zhang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Kenton Wu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Jennifer Guo
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Alissa L Nana
- Department of Neurology, University of California, San Francisco, CA, 94158, USA
| | - Guang Yang
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - William W Seeley
- Department of Neurology, University of California, San Francisco, CA, 94158, USA
- Department of Pathology, University of California, San Francisco, CA, 94158, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA.
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16
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Perneel J, Neumann M, Heeman B, Cheung S, Van den Broeck M, Wynants S, Baker M, Vicente CT, Faura J, Rademakers R, Mackenzie IRA. Accumulation of TMEM106B C-terminal fragments in neurodegenerative disease and aging. Acta Neuropathol 2023; 145:285-302. [PMID: 36527486 DOI: 10.1007/s00401-022-02531-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/21/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022]
Abstract
Several studies using cryogenic electron microscopy (cryo-EM) techniques recently reported the isolation and characterization of novel protein filaments, composed of a C-terminal fragment (CTF) of the endolysosomal transmembrane protein 106B (TMEM106B), from human post-mortem brain tissue with various neurodegenerative conditions and normal aging. Genetic variation in TMEM106B is known to influence the risk and presentation of several neurodegenerative diseases, especially frontotemporal dementia (FTD) caused by mutations in the progranulin gene (GRN). To further elucidate the significance of TMEM106B CTF, we performed immunohistochemistry with antibodies directed against epitopes within the filament-forming C-terminal region of TMEM106B. Accumulation of TMEM106B C-terminal immunoreactive (TMEM-ir) material was a common finding in all the conditions evaluated, including frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP), Alzheimer's disease, tauopathies, synucleinopathies and neurologically normal aging. TMEM-ir material was present in a wide range of brain cell types and in a broad neuroanatomical distribution; however, there was no co-localization of TMEM-ir material with other neurodegenerative proteins in cellular inclusions. In most conditions, the presence and abundance of TMEM-ir aggregates correlated strongly with patient age and showed only a weak correlation with the TMEM106B haplotype or the primary pathological diagnosis. However, all patients with FTD caused by GRN mutations were found to have high levels of TMEM-ir material, including several who were relatively young (< 60 years). These findings suggest that the accumulation of TMEM106B CTF is a common age-related phenomenon, which may reflect lysosomal dysfunction. Although its significance in most neurodegenerative conditions remains uncertain, the consistent finding of extensive TMEM-ir material in cases of FTLD-TDP with GRN mutations further supports a pathomechanistic role of TMEM106B and lysosomal dysfunction in this specific disease population.
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Affiliation(s)
- Jolien Perneel
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Manuela Neumann
- Department of Neuropathology, University of Tübingen, Tübingen, Germany.,Molecular Neuropathology of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Bavo Heeman
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Simon Cheung
- Department of Pathology, Vancouver Coastal Health, Vancouver, BC, Canada
| | - Marleen Van den Broeck
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Sarah Wynants
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Matt Baker
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Cristina T Vicente
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Júlia Faura
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Rosa Rademakers
- VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
| | - Ian R A Mackenzie
- Department of Pathology, Vancouver Coastal Health, Vancouver, BC, Canada. .,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
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17
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Lee JY, Harney D, Kwok J, Larance M, Don AS. The major TMEM106B dementia risk allele affects TMEM106B protein levels and myelin lipid homeostasis in the ageing human hippocampus. RESEARCH SQUARE 2023:rs.3.rs-2392941. [PMID: 36711721 PMCID: PMC9882607 DOI: 10.21203/rs.3.rs-2392941/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Background The risk for dementia increases exponentially from the seventh decade of life. Identifying and understanding the biochemical changes that sensitize the ageing brain to neurodegeneration will provide new opportunities for dementia prevention and treatment. This study aimed to determine how ageing and major genetic risk factors for dementia affect the hippocampal proteome and lipidome of neurologically-normal humans over the age of 65. The hippocampus was chosen as it is highly susceptible to atrophy with ageing and in several neurodegenerative diseases. Methods Mass spectrometry-based proteomic and lipidomic analysis of CA1 hippocampus samples from 74 neurologically normal human donors, aged 66-104, was used in combination with multiple regression models and gene set enrichment analysis to identify age-dependent changes in the proteome and lipidome. ANOVA was used to test the effect of major dementia risk alleles in the TMEM106B and APOE genes on the hippocampal proteome and lipidome, adjusting for age, gender, and post-mortem interval. Results Forty proteins were associated with age at false discovery rate-corrected P < 0.05, including proteins that regulate cell adhesion, the cytoskeleton, amino acid and lipid metabolism, and ribosomal subunits. Transmembrane protein 106B (TMEM106B), a regulator of lysosomal and oligodendrocyte function, was regulated with greatest effect size. The increase in TMEM106B levels with age was specific to carriers of the rs1990622-A allele in the TMEM106B gene that is associated with increased risk for frontotemporal dementia, Alzheimer's disease, Parkinson's disease, and hippocampal sclerosis with ageing. Hippocampal lipids were not significantly affected by APOE genotype, however levels of myelin-enriched sulfatides and hexosylceramides were significantly lower, and polyunsaturated phospholipids were higher, in rs1990622-A carriers after controlling for APOE genotype. Conclusions Our study provides the first evidence that TMEM106B protein abundance is increased with brain ageing in humans, and the first evidence that the major TMEM106B dementia risk allele affects brain lipid homeostasis, with a clear effect on myelin lipid content. Our data implies that TMEM106B is one of a growing list of major dementia risk genes that affect glial lipid metabolism.
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Affiliation(s)
- Jun Yup Lee
- The University of Sydney SMS: The University of Sydney School of Medical Sciences
| | | | - John Kwok
- The University of Sydney SMS: The University of Sydney School of Medical Sciences
| | - Mark Larance
- The University of Sydney SMS: The University of Sydney School of Medical Sciences
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18
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Nowacki JC, Fields AM, Fu MM. Emerging cellular themes in leukodystrophies. Front Cell Dev Biol 2022; 10:902261. [PMID: 36003149 PMCID: PMC9393611 DOI: 10.3389/fcell.2022.902261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.
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19
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Homotypic fibrillization of TMEM106B across diverse neurodegenerative diseases. Cell 2022; 185:1346-1355.e15. [PMID: 35247328 PMCID: PMC9018563 DOI: 10.1016/j.cell.2022.02.026] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/14/2022] [Accepted: 02/23/2022] [Indexed: 02/08/2023]
Abstract
Misfolding and aggregation of disease-specific proteins, resulting in the formation of filamentous cellular inclusions, is a hallmark of neurodegenerative disease with characteristic filament structures, or conformers, defining each proteinopathy. Here we show that a previously unsolved amyloid fibril composed of a 135 amino acid C-terminal fragment of TMEM106B is a common finding in distinct human neurodegenerative diseases, including cases characterized by abnormal aggregation of TDP-43, tau, or α-synuclein protein. A combination of cryoelectron microscopy and mass spectrometry was used to solve the structures of TMEM106B fibrils at a resolution of 2.7 Å from postmortem human brain tissue afflicted with frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP, n = 8), progressive supranuclear palsy (PSP, n = 2), or dementia with Lewy bodies (DLB, n = 1). The commonality of abundant amyloid fibrils composed of TMEM106B, a lysosomal/endosomal protein, to a broad range of debilitating human disorders indicates a shared fibrillization pathway that may initiate or accelerate neurodegeneration.
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20
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Feng T, Luan L, Katz II, Ullah M, Van Deerlin VM, Trojanowski JQ, Lee EB, Hu F. TMEM106B deficiency impairs cerebellar myelination and synaptic integrity with Purkinje cell loss. Acta Neuropathol Commun 2022; 10:33. [PMID: 35287730 PMCID: PMC8919601 DOI: 10.1186/s40478-022-01334-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 12/19/2022] Open
Abstract
TMEM106B, a type II lysosomal transmembrane protein, has recently been associated with brain aging, hypomyelinating leukodystrophy, frontotemporal lobar degeneration (FTLD) and several other brain disorders. TMEM106B is critical for proper lysosomal function and TMEM106B deficiency leads to myelination defects, FTLD related pathology, and motor coordination deficits in mice. However, the physiological and pathological functions of TMEM106B in the brain are still not well understood. In this study, we investigate the role of TMEM106B in the cerebellum, dysfunction of which has been associated with FTLD and other brain disorders. We found that TMEM106B is ubiquitously expressed in neurons in the cerebellum, with the highest levels in the Purkinje neurons. Aged TMEM106B-deficient mice show significant loss of Purkinje neurons specifically in the anterior lobe of the cerebellum. Increased microglia and astrocyte activation, as well as an accumulation of ubiquitinated proteins, p62 and TDP-43 were also detected in the cerebellum of aged TMEM106B deficient mice. In the young mice, myelination defects and a significant loss of synapses between Purkinje and deep cerebellar nuclei neurons were observed. Interestingly, TMEM106B deficiency causes distinct lysosomal phenotypes in different types of neurons and glia in the cerebellum and frontal cortex. In humans, TMEM106B rs1990622 risk allele (T/T) is associated with increased Purkinje neuron loss. Taken together, our studies support that TMEM106B regulates lysosomal function in a cell-type-specific manner and TMEM106B is critical for maintaining synaptic integrity and neural functions in the cerebellum.
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Affiliation(s)
- Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Lin Luan
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Isabel Iscol Katz
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Mohammed Ullah
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA
| | - Vivianna M Van Deerlin
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, Institute On Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, Institute On Aging, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, 345 Weill Hall, Ithaca, NY, 14853, USA.
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21
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Identification of TMEM106B amyloid fibrils provides an updated view of TMEM106B biology in health and disease. Acta Neuropathol 2022; 144:807-819. [PMID: 36056242 PMCID: PMC9547799 DOI: 10.1007/s00401-022-02486-5] [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: 06/10/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 01/26/2023]
Abstract
Since the initial identification of TMEM106B as a risk factor for frontotemporal lobar degeneration (FTLD), multiple genetic studies have found TMEM106B variants to modulate disease risk in a variety of brain disorders and healthy aging. Neurodegenerative disorders are typically characterized by inclusions of misfolded proteins and since lysosomes are an important site for cellular debris clearance, lysosomal dysfunction has been closely linked to neurodegeneration. Consequently, many causal mutations or genetic risk variants implicated in neurodegenerative diseases encode proteins involved in endosomal-lysosomal function. As an integral lysosomal transmembrane protein, TMEM106B regulates several aspects of lysosomal function and multiple studies have shown that proper TMEM106B protein levels are crucial for maintaining lysosomal health. Yet, the precise function of TMEM106B at the lysosomal membrane is undetermined and it remains unclear how TMEM106B modulates disease risk. Unexpectedly, several independent groups recently showed that the C-terminal domain (AA120-254) of TMEM106B forms amyloid fibrils in the brain of patients with a diverse set of neurodegenerative conditions. The recognition that TMEM106B can form amyloid fibrils and is present across neurodegenerative diseases sheds new light on TMEM106B as a central player in neurodegeneration and brain health, but also raises important new questions. In this review, we summarize current knowledge and place a decade's worth of TMEM106B research into an exciting new perspective.
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22
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Levine TP. TMEM106B in humans and Vac7 and Tag1 in yeast are predicted to be lipid transfer proteins. Proteins 2021; 90:164-175. [PMID: 34347309 DOI: 10.1002/prot.26201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 07/11/2021] [Accepted: 07/23/2021] [Indexed: 11/05/2022]
Abstract
TMEM106B is an integral membrane protein of late endosomes and lysosomes involved in neuronal function, its overexpression being associated with familial frontotemporal lobar degeneration, and point mutation linked to hypomyelination. It has also been identified in multiple screens for host proteins required for productive SARS-CoV-2 infection. Because standard approaches to understand TMEM106B at the sequence level find no homology to other proteins, it has remained a protein of unknown function. Here, the standard tool PSI-BLAST was used in a nonstandard way to show that the lumenal portion of TMEM106B is a member of the late embryogenesis abundant-2 (LEA-2) domain superfamily. More sensitive tools (HMMER, HHpred, and trRosetta) extended this to predict LEA-2 domains in two yeast proteins. One is Vac7, a regulator of PI(3,5)P2 production in the degradative vacuole, equivalent to the lysosome, which has a LEA-2 domain in its lumenal domain. The other is Tag1, another vacuolar protein, which signals to terminate autophagy and has three LEA-2 domains in its lumenal domain. Further analysis of LEA-2 structures indicated that LEA-2 domains have a long, conserved lipid-binding groove. This implies that TMEM106B, Vac7, and Tag1 may all be lipid transfer proteins in the lumen of late endocytic organelles.
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23
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Sirkis DW, Bonham LW, Yokoyama JS. The Role of Microglia in Inherited White-Matter Disorders and Connections to Frontotemporal Dementia. Appl Clin Genet 2021; 14:195-207. [PMID: 33833548 PMCID: PMC8020808 DOI: 10.2147/tacg.s245029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022] Open
Abstract
Microglia play a critical but poorly understood role in promoting white-matter homeostasis. In this review, we leverage advances in human genetics and mouse models of leukodystrophies to delineate our current knowledge and identify outstanding questions regarding the impact of microglia on central nervous system white matter. We first focus on the role of pathogenic mutations in genes, such as TREM2, TYROBP, and CSF1R, that cause leukodystrophies in which the primary deficit is thought to originate in microglia. We next discuss recent advances in disorders such as adrenoleukodystrophy and Krabbe disease, in which microglia play an increasingly recognized role. We conclude by reviewing the roles of GRN and related genes, such as TMEM106B, PSAP, and SORT1, that affect microglial biology and associate with several types of disease, including multiple leukodystrophies as well as forms of frontotemporal dementia (FTD) presenting with white-matter abnormalities. Taken together, mouse and human data support the notion that loss of microglia-facilitated white-matter homeostasis plays an important role in the development of leukodystrophies and suggest novel mechanisms contributing to FTD.
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Affiliation(s)
- Daniel W Sirkis
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Luke W Bonham
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA.,Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Jennifer S Yokoyama
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA.,Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, 94158, USA
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24
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Physiological and pathological functions of TMEM106B: a gene associated with brain aging and multiple brain disorders. Acta Neuropathol 2021; 141:327-339. [PMID: 33386471 DOI: 10.1007/s00401-020-02246-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 12/12/2022]
Abstract
TMEM106B, encoding a lysosome membrane protein, has been recently associated with brain aging, hypomyelinating leukodystrophy and multiple neurodegenerative diseases, such as frontotemporal lobar degeneration (FTLD) and limbic-predominant age-related TDP-43 encephalopathy (LATE). During the past decade, considerable progress has been made towards our understanding of the cellular and physiological functions of TMEM106B. TMEM106B regulates many aspects of lysosomal function, including lysosomal pH, lysosome movement, and lysosome exocytosis. Both an increase and decrease in TMEM106B levels result in lysosomal abnormalities. In mouse models, TMEM106B deficiency leads to lysosome trafficking and myelination defects and FTLD related pathology. In humans, alterations in TMEM106B levels or function are intimately linked to neuronal proportions, brain aging, and brain disorders. Further elucidation of the physiological function of TMEM106B and changes in TMEM106B under pathological conditions will facilitate therapeutic development to treat brain disorders associated with TMEM106B.
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25
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Abstract
Hypomyelinating leukodystrophies constitute a subset of genetic white matter disorders characterized by a primary lack of myelin deposition. Most patients with severe hypomyelination present in infancy or early childhood and develop severe neurological deficits, but the clinical presentation can also be mild with onset of symptoms in adolescence or adulthood. MRI can be used to visualize the process of myelination in detail, and MRI pattern recognition can provide a clinical diagnosis in many patients. Next-generation sequencing provides a definitive diagnosis in 80-90% of patients. Genes associated with hypomyelination include those that encode structural myelin proteins but also many that encode proteins involved in RNA translation and some lysosomal proteins. The precise pathomechanisms remain to be elucidated. Improved understanding of the process of myelination, the metabolic axonal support functions of myelin and the proposed contribution of myelin to CNS plasticity provide possible explanations as to why almost all patients with hypomyelination experience slow clinical decline after a long phase of stability. In this Review, we provide an overview of the hypomyelinating leukodystrophies, the advances in our understanding of myelin biology and of the genes involved in these disorders, and the insights these advances have provided into their clinical presentations and evolution.
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26
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Perez-Canamas A, Takahashi H, Lindborg JA, Strittmatter SM. Fronto-temporal dementia risk gene TMEM106B has opposing effects in different lysosomal storage disorders. Brain Commun 2020; 3:fcaa200. [PMID: 33796852 PMCID: PMC7990118 DOI: 10.1093/braincomms/fcaa200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/02/2020] [Accepted: 10/09/2020] [Indexed: 02/07/2023] Open
Abstract
TMEM106B is a transmembrane protein localized to the endo-lysosomal compartment. Genome-wide association studies have identified TMEM106B as a risk modifier of Alzheimer's disease and frontotemporal lobar degeneration, especially with progranulin haploinsufficiency. We recently demonstrated that TMEM106B loss rescues progranulin null mouse phenotypes including lysosomal enzyme dysregulation, neurodegeneration and behavioural alterations. However, the reason whether TMEM106B is involved in other neurodegenerative lysosomal diseases is unknown. Here, we evaluate the potential role of TMEM106B in modifying the progression of lysosomal storage disorders using progranulin-independent models of Gaucher disease and neuronal ceroid lipofuscinosis. To study Gaucher disease, we employ a pharmacological approach using the inhibitor conduritol B epoxide in wild-type and hypomorphic Tmem106b-/- mice. TMEM106B depletion ameliorates neuronal degeneration and some behavioural abnormalities in the pharmacological model of Gaucher disease, similar to its effect on certain progranulin null phenotypes. In order to examine the role of TMEM106B in neuronal ceroid lipofuscinosis, we crossbred Tmem106b-/- mice with Ppt1-/-, a genetic model of the disease. In contrast to its conduritol B epoxide-rescuing effect, TMEM106B loss exacerbates Purkinje cell degeneration and motor deficits in Ppt1-/- mice. Mechanistically, TMEM106B is known to interact with subunits of the vacuolar ATPase and influence lysosomal acidification. In the pharmacological Gaucher disease model, the acidified lysosomal compartment is enhanced and TMEM106B loss rescues in vivo phenotypes. In contrast, gene-edited neuronal loss of Ppt1 causes a reduction in vacuolar ATPase levels and impairment of the acidified lysosomal compartment, and TMEM106B deletion exacerbates the mouse Ppt1-/- phenotype. Our findings indicate that TMEM106B differentially modulates the progression of the lysosomal storage disorders Gaucher disease and neuronal ceroid lipofuscinosis. The effect of TMEM106B in neurodegeneration varies depending on vacuolar ATPase state and modulation of lysosomal pH. These data suggest TMEM106B as a target for correcting lysosomal pH alterations, and in particular for therapeutic intervention in Gaucher disease and neuronal ceroid lipofuscinosis.
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Affiliation(s)
- Azucena Perez-Canamas
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Hideyuki Takahashi
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Jane A Lindborg
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
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27
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Stroobants S, D'Hooge R, Damme M. Aged Tmem106b knockout mice display gait deficits in coincidence with Purkinje cell loss and only limited signs of non-motor dysfunction. Brain Pathol 2020; 31:223-238. [PMID: 33016371 PMCID: PMC8018119 DOI: 10.1111/bpa.12903] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/14/2020] [Accepted: 09/28/2020] [Indexed: 12/13/2022] Open
Abstract
Genetic variants in TMEM106B are a major risk factor for several neurodegenerative diseases including frontotemporal degeneration, limbic‐predominant age‐related TDP‐43 encephalopathy, Parkinson's disease, late‐onset‐Alzheimer's disease and constitute a genetic determinant of differential aging. TMEM106B encodes an integral lysosomal membrane protein but its precise physiological function in the central nervous system remains enigmatic. Presently, we aimed to increase understanding of TMEM106B contribution to general brain function and aging. We analyzed an aged cohort of Tmem106b knockout‐, heterozygote and wild‐type mice in a behavioral test battery including assessments of motor function as well as, social, emotional and cognitive function. Aged Tmem106b knockout (KO) mice displayed diverse behavioral deficits including motor impairment, gait defects and reduced startle reactivity. In contrast, no prominent deficits were observed in social, emotional or cognitive behaviors. Histologically, we observed late‐onset loss of Purkinje cells followed by reactive gliosis in the cerebellum, which likely contributed to progressive decline in motor function and gait defects in particular. Reactive gliosis was not restricted to the cerebellum but observed in different areas of the brain including the brain stem and parts of the cerebral cortex. Surviving Purkinje cells showed vacuolated lysosomes in the axon initial segment, implicating TMEM106B‐dependent lysosomal trafficking defects as the underlying cause of axonal and more general neuronal dysfunction contributing to behavioral impairments. Our experiments help to elucidate how TMEM106B affects spatial neuronal homeostasis and exemplifies a critical role of TMEM106B in neuronal cells for survival.
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Affiliation(s)
- Stijn Stroobants
- Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Leuven, 3000, Belgium
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, KU Leuven, Tiensestraat 102, Leuven, 3000, Belgium
| | - Markus Damme
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Kiel, 24098, Germany
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28
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Werner G, Damme M, Schludi M, Gnörich J, Wind K, Fellerer K, Wefers B, Wurst W, Edbauer D, Brendel M, Haass C, Capell A. Loss of TMEM106B potentiates lysosomal and FTLD-like pathology in progranulin-deficient mice. EMBO Rep 2020; 21:e50241. [PMID: 32929860 PMCID: PMC7534633 DOI: 10.15252/embr.202050241] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 12/13/2022] Open
Abstract
Single nucleotide polymorphisms (SNPs) in TMEM106B encoding the lysosomal type II transmembrane protein 106B increase the risk for frontotemporal lobar degeneration (FTLD) of GRN (progranulin gene) mutation carriers. Currently, it is unclear if progranulin (PGRN) and TMEM106B are synergistically linked and if a gain or a loss of function of TMEM106B is responsible for the increased disease risk of patients with GRN haploinsufficiency. We therefore compare behavioral abnormalities, gene expression patterns, lysosomal activity, and TDP‐43 pathology in single and double knockout animals. Grn−/−/Tmem106b−/− mice show a strongly reduced life span and massive motor deficits. Gene expression analysis reveals an upregulation of molecular signature characteristic for disease‐associated microglia and autophagy. Dysregulation of maturation of lysosomal proteins as well as an accumulation of ubiquitinated proteins and widespread p62 deposition suggest that proteostasis is impaired. Moreover, while single Grn−/− knockouts only occasionally show TDP‐43 pathology, the double knockout mice exhibit deposition of phosphorylated TDP‐43. Thus, a loss of function of TMEM106B may enhance the risk for GRN‐associated FTLD by reduced protein turnover in the lysosomal/autophagic system.
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Affiliation(s)
- Georg Werner
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Markus Damme
- Institute of Biochemistry, Kiel University, Kiel, Germany
| | - Martin Schludi
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Johannes Gnörich
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Karin Wind
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Katrin Fellerer
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Benedikt Wefers
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Wolfgang Wurst
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Haass
- 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
| | - Anja Capell
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
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29
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Feng T, Mai S, Roscoe JM, Sheng RR, Ullah M, Zhang J, Katz II, Yu H, Xiong W, Hu F. Loss of TMEM106B and PGRN leads to severe lysosomal abnormalities and neurodegeneration in mice. EMBO Rep 2020; 21:e50219. [PMID: 32852886 PMCID: PMC7534636 DOI: 10.15252/embr.202050219] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 06/25/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
Haploinsufficiency of progranulin (PGRN) is a leading cause of frontotemporal lobar degeneration (FTLD). Loss of PGRN leads to lysosome dysfunction during aging. TMEM106B, a gene encoding a lysosomal membrane protein, is the main risk factor for FTLD with PGRN haploinsufficiency. But how TMEM106B affects FTLD disease progression remains to be determined. Here, we report that TMEM106B deficiency in mice leads to accumulation of lysosome vacuoles at the distal end of the axon initial segment in motor neurons and the development of FTLD‐related pathology during aging. Ablation of both PGRN and TMEM106B in mice results in severe neuronal loss and glial activation in the spinal cord, retina, and brain. Enlarged lysosomes are frequently found in both microglia and astrocytes. Loss of both PGRN and TMEM106B results in an increased accumulation of lysosomal vacuoles in the axon initial segment of motor neurons and enhances the manifestation of FTLD phenotypes with a much earlier onset. These results provide novel insights into the role of TMEM106B in the lysosome, in brain aging, and in FTLD pathogenesis.
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Affiliation(s)
- Tuancheng Feng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Shuyi Mai
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Jenn Marie Roscoe
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Rory R Sheng
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Mohammed Ullah
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Junke Zhang
- Department of Computational Biology, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Isabel Iscol Katz
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Haiyuan Yu
- Department of Computational Biology, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Wenjun Xiong
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
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