1
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Liénard C, Pintart A, Bomont P. Neuronal Autophagy: Regulations and Implications in Health and Disease. Cells 2024; 13:103. [PMID: 38201307 PMCID: PMC10778363 DOI: 10.3390/cells13010103] [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: 10/26/2023] [Revised: 12/02/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Autophagy is a major degradative pathway that plays a key role in sustaining cell homeostasis, integrity, and physiological functions. Macroautophagy, which ensures the clearance of cytoplasmic components engulfed in a double-membrane autophagosome that fuses with lysosomes, is orchestrated by a complex cascade of events. Autophagy has a particularly strong impact on the nervous system, and mutations in core components cause numerous neurological diseases. We first review the regulation of autophagy, from autophagosome biogenesis to lysosomal degradation and associated neurodevelopmental/neurodegenerative disorders. We then describe how this process is specifically regulated in the axon and in the somatodendritic compartment and how it is altered in diseases. In particular, we present the neuronal specificities of autophagy, with the spatial control of autophagosome biogenesis, the close relationship of maturation with axonal transport, and the regulation by synaptic activity. Finally, we discuss the physiological functions of autophagy in the nervous system, during development and in adulthood.
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Affiliation(s)
- Caroline Liénard
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
- CHU Montpellier, University of Montpellier, 34295 Montpellier, France
| | - Alexandre Pintart
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
| | - Pascale Bomont
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
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2
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Kim SH, Nichols KD, Anderson EN, Liu Y, Ramesh N, Jia W, Kuerbis CJ, Scalf M, Smith LM, Pandey UB, Tibbetts RS. Axon guidance genes modulate neurotoxicity of ALS-associated UBQLN2. eLife 2023; 12:e84382. [PMID: 37039476 PMCID: PMC10147378 DOI: 10.7554/elife.84382] [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: 10/22/2022] [Accepted: 04/06/2023] [Indexed: 04/12/2023] Open
Abstract
Mutations in the ubiquitin (Ub) chaperone Ubiquilin 2 (UBQLN2) cause X-linked forms of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) through unknown mechanisms. Here, we show that aggregation-prone, ALS-associated mutants of UBQLN2 (UBQLN2ALS) trigger heat stress-dependent neurodegeneration in Drosophila. A genetic modifier screen implicated endolysosomal and axon guidance genes, including the netrin receptor, Unc-5, as key modulators of UBQLN2 toxicity. Reduced gene dosage of Unc-5 or its coreceptor Dcc/frazzled diminished neurodegenerative phenotypes, including motor dysfunction, neuromuscular junction defects, and shortened lifespan, in flies expressing UBQLN2ALS alleles. Induced pluripotent stem cells (iPSCs) harboring UBQLN2ALS knockin mutations exhibited lysosomal defects while inducible motor neurons (iMNs) expressing UBQLN2ALS alleles exhibited cytosolic UBQLN2 inclusions, reduced neurite complexity, and growth cone defects that were partially reversed by silencing of UNC5B and DCC. The combined findings suggest that altered growth cone dynamics are a conserved pathomechanism in UBQLN2-associated ALS/FTD.
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Affiliation(s)
- Sang Hwa Kim
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Kye D Nichols
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Yining Liu
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Nandini Ramesh
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Weiyan Jia
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Connor J Kuerbis
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Udai Bhan Pandey
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Randal S Tibbetts
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
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3
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Black HH, Hanson JL, Roberts JE, Leslie SN, Campodonico W, Ebmeier CC, Holling GA, Tay JW, Matthews AM, Ung E, Lau CI, Whiteley AM. UBQLN2 restrains the domesticated retrotransposon PEG10 to maintain neuronal health in ALS. eLife 2023; 12:e79452. [PMID: 36951542 PMCID: PMC10076021 DOI: 10.7554/elife.79452] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 03/15/2023] [Indexed: 03/24/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron dysfunction and loss. A portion of ALS cases are caused by mutation of the proteasome shuttle factor Ubiquilin 2 (UBQLN2), but the molecular pathway leading from UBQLN2 dysfunction to disease remains unclear. Here, we demonstrate that UBQLN2 regulates the domesticated gag-pol retrotransposon 'paternally expressed gene 10 (PEG10)' in human cells and tissues. In cells, the PEG10 gag-pol protein cleaves itself in a mechanism reminiscent of retrotransposon self-processing to generate a liberated 'nucleocapsid' fragment, which uniquely localizes to the nucleus and changes the expression of genes involved in axon remodeling. In spinal cord tissue from ALS patients, PEG10 gag-pol is elevated compared to healthy controls. These findings implicate the retrotransposon-like activity of PEG10 as a contributing mechanism in ALS through the regulation of gene expression, and restraint of PEG10 as a primary function of UBQLN2.
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Affiliation(s)
- Holly H Black
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Jessica L Hanson
- Institute for Behavioral Genetics, University of Colorado BoulderBoulderUnited States
| | - Julia E Roberts
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Shannon N Leslie
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Will Campodonico
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | | | - G Aaron Holling
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Jian Wei Tay
- Biofrontiers Institute, University of Colorado BoulderBoulderUnited States
| | - Autumn M Matthews
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Elizabeth Ung
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
| | - Cristina I Lau
- Department of Biochemistry, University of Colorado BoulderBoulderUnited States
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4
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Piol D, Robberechts T, Da Cruz S. Lost in local translation: TDP-43 and FUS in axonal/neuromuscular junction maintenance and dysregulation in amyotrophic lateral sclerosis. Neuron 2023; 111:1355-1380. [PMID: 36963381 DOI: 10.1016/j.neuron.2023.02.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/21/2022] [Accepted: 02/16/2023] [Indexed: 03/26/2023]
Abstract
Key early features of amyotrophic lateral sclerosis (ALS) are denervation of neuromuscular junctions and axonal degeneration. Motor neuron homeostasis relies on local translation through controlled regulation of axonal mRNA localization, transport, and stability. Yet the composition of the local transcriptome, translatome (mRNAs locally translated), and proteome during health and disease remains largely unexplored. This review covers recent discoveries on axonal translation as a critical mechanism for neuronal maintenance/survival. We focus on two RNA binding proteins, transactive response DNA binding protein-43 (TDP-43) and fused in sarcoma (FUS), whose mutations cause ALS and frontotemporal dementia (FTD). Emerging evidence points to their essential role in the maintenance of axons and synapses, including mRNA localization, transport, and local translation, and whose dysfunction may contribute to ALS. Finally, we describe recent advances in omics-based approaches mapping compartment-specific local RNA and protein compositions, which will be invaluable to elucidate fundamental local processes and identify key targets for therapy development.
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Affiliation(s)
- Diana Piol
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium
| | - Tessa Robberechts
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium
| | - Sandrine Da Cruz
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium.
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5
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Sandoval-Pistorius SS, Gerson JE, Liggans N, Ryou JH, Oak K, Li X, Negron-Rios KY, Fischer S, Barsh H, Crowley EV, Skinner ME, Sharkey LM, Barmada SJ, Paulson HL. Ubiquilin-2 regulates pathological alpha-synuclein. Sci Rep 2023; 13:293. [PMID: 36609661 PMCID: PMC9823102 DOI: 10.1038/s41598-022-26899-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 12/21/2022] [Indexed: 01/08/2023] Open
Abstract
The key protein implicated in Parkinson's disease and other synucleinopathies is α-synuclein, and a post-translationally modified form of the protein, phosphorylated at serine 129 (pS129), is a principal component in Lewy bodies, a pathological hallmark of PD. While altered proteostasis has been implicated in the etiology of Parkinson's disease, we still have a limited understanding of how α-synuclein is regulated in the nervous system. The protein quality control protein Ubiquilin-2 (UBQLN2) is known to accumulate in synucleinopathies, but whether it directly regulates α-synuclein is unknown. Using cellular and mouse models, we find that UBQLN2 decreases levels of α-synuclein, including the pS129 phosphorylated isoform. Pharmacological inhibition of the proteasome revealed that, while α-synuclein may be cleared by parallel and redundant quality control pathways, UBQLN2 preferentially targets pS129 for proteasomal degradation. Moreover, in brain tissue from human PD and transgenic mice expressing pathogenic α-synuclein (A53T), native UBQLN2 becomes more insoluble. Collectively, our studies support a role for UBQLN2 in directly regulating pathological forms of α-synuclein and indicate that UBQLN2 dysregulation in disease may contribute to α-synuclein-mediated toxicity.
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Affiliation(s)
- Stephanie S. Sandoval-Pistorius
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109 USA
| | - Julia E. Gerson
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Nyjerus Liggans
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Jaimie H. Ryou
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Kulin Oak
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Xingli Li
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Keyshla Y. Negron-Rios
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Svetlana Fischer
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Henry Barsh
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Emily V. Crowley
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Mary E. Skinner
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Lisa M. Sharkey
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Sami J. Barmada
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Henry L. Paulson
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200 USA
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6
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Busch AM, Kovlyagina I, Lutz B, Todorov H, Gerber S. beeRapp: an R shiny app for automated high-throughput explorative analysis of multivariate behavioral data. BIOINFORMATICS ADVANCES 2022; 2:vbac082. [PMID: 36699414 PMCID: PMC9710645 DOI: 10.1093/bioadv/vbac082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/12/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022]
Abstract
Summary Animal behavioral studies typically generate high-dimensional datasets consisting of multiple correlated outcome measures across distinct or related behavioral domains. Here, we introduce the BEhavioral Explorative analysis R shiny APP (beeRapp) that facilitates explorative and inferential analysis of behavioral data in a high-throughput fashion. By employing an intuitive and user-friendly graphical user interface, beeRapp empowers behavioral scientists without programming and data science expertise to perform clustering, dimensionality reduction, correlational and inferential statistics and produce up to thousands of high-quality output plots visualizing results in a standardized and automated way. Availability and implementation The code and data underlying this article are available at https://github.com/anmabu/beeRapp.
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Affiliation(s)
- Anne Marie Busch
- Institute of Human Genetics, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55128, Germany
| | - Irina Kovlyagina
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55128, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55128, Germany,Leibniz Institute for Resilience Research (LIR), Mainz 55122, Germany
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7
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Lin BC, Higgins NR, Phung TH, Monteiro MJ. UBQLN proteins in health and disease with a focus on UBQLN2 in ALS/FTD. FEBS J 2022; 289:6132-6153. [PMID: 34273246 PMCID: PMC8761781 DOI: 10.1111/febs.16129] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/08/2021] [Accepted: 07/16/2021] [Indexed: 01/12/2023]
Abstract
Ubiquilin (UBQLN) proteins are a dynamic and versatile family of proteins found in all eukaryotes that function in the regulation of proteostasis. Besides their canonical function as shuttle factors in delivering misfolded proteins to the proteasome and autophagy systems for degradation, there is emerging evidence that UBQLN proteins play broader roles in proteostasis. New information suggests the proteins function as chaperones in protein folding, protecting proteins prior to membrane insertion, and as guardians for mitochondrial protein import. In this review, we describe the evidence for these different roles, highlighting how different domains of the proteins impart these functions. We also describe how changes in the structure and phase separation properties of UBQLNs may regulate their activity and function. Finally, we discuss the pathogenic mechanisms by which mutations in UBQLN2 cause amyotrophic lateral sclerosis and frontotemporal dementia. We describe the animal model systems made for different UBQLN2 mutations and how lessons learnt from these systems provide fundamental insight into the molecular mechanisms by which UBQLN2 mutations drive disease pathogenesis through disturbances in proteostasis.
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Affiliation(s)
- Brian C. Lin
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA,Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nicole R. Higgins
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA,Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Trong H. Phung
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mervyn J. Monteiro
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD, USA,Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA,Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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8
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The potential use of tetracyclines in neurodegenerative diseases and the role of nano-based drug delivery systems. Eur J Pharm Sci 2022; 175:106237. [PMID: 35710076 DOI: 10.1016/j.ejps.2022.106237] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/07/2022] [Accepted: 06/12/2022] [Indexed: 11/21/2022]
Abstract
Neurodegenerative diseases are still a challenge for effective treatments. The high cost of approved drugs, severity of side effects, injection site pain, and restrictions on drug delivery to the Central Nervous System (CNS) can overshadow the management of these diseases. Due to the chronic and progressive evolution of neurodegenerative disorders and since there is still no cure for them, new therapeutic strategies such as the combination of several drugs or the use of existing drugs with new therapeutic applications are valuable strategies. Tetracyclines are traditionally classified as antibiotics. However, in this class of drugs, doxycycline and minocycline exhibit also anti-inflammatory effects by inhibiting microglia/macrophages. Hence, they have been studied as potential agents for the treatment of neurodegenerative diseases. The results of in vitro and in vivo studies confirm the effective role of these two drugs as anti-inflammatory agents in experimentally induced models of neurodegenerative diseases. In clinical studies, satisfactory results have been obtained in Multiple sclerosis (MS) but not yet in other disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), or Amyotrophic lateral sclerosis (ALS). In recent years, researchers have developed and evaluated nanoparticulate drug delivery systems to improve the clinical efficacy of these two tetracyclines for their potential application in neurodegenerative diseases. This study reviews the neuroprotective roles of minocycline and doxycycline in four of the main neurodegenerative disorders: AD, PD, ALS and MS. Moreover, the potential applications of nanoparticulate delivery systems developed for both tetracyclines are also reviewed.
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9
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Todd TW, Petrucelli L. Modelling amyotrophic lateral sclerosis in rodents. Nat Rev Neurosci 2022; 23:231-251. [PMID: 35260846 DOI: 10.1038/s41583-022-00564-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2022] [Indexed: 12/11/2022]
Abstract
The efficient study of human disease requires the proper tools, one of the most crucial of which is an accurate animal model that faithfully recapitulates the human condition. The study of amyotrophic lateral sclerosis (ALS) is no exception. Although the majority of ALS cases are considered sporadic, most animal models of this disease rely on genetic mutations identified in familial cases. Over the past decade, the number of genes associated with ALS has risen dramatically and, with each new genetic variant, there is a drive to develop associated animal models. Rodent models are of particular importance as they allow for the study of ALS in the context of a living mammal with a comparable CNS. Such models not only help to verify the pathogenicity of novel mutations but also provide critical insight into disease mechanisms and are crucial for the testing of new therapeutics. In this Review, we aim to summarize the full spectrum of ALS rodent models developed to date.
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Affiliation(s)
- Tiffany W Todd
- Department of Neuroscience, Mayo Clinic Jacksonville, Jacksonville, FL, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic Jacksonville, Jacksonville, FL, USA.
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10
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Mohan HM, Trzeciakiewicz H, Pithadia A, Crowley EV, Pacitto R, Safren N, Trotter B, Zhang C, Zhou X, Zhang Y, Basrur V, Paulson HL, Sharkey LM. RTL8 promotes nuclear localization of UBQLN2 to subnuclear compartments associated with protein quality control. Cell Mol Life Sci 2022; 79:176. [PMID: 35247097 PMCID: PMC9376861 DOI: 10.1007/s00018-022-04170-z] [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: 04/19/2021] [Revised: 01/17/2022] [Accepted: 01/25/2022] [Indexed: 11/24/2022]
Abstract
The brain-expressed ubiquilins (UBQLNs) 1, 2 and 4 are a family of ubiquitin adaptor proteins that participate broadly in protein quality control (PQC) pathways, including the ubiquitin proteasome system (UPS). One family member, UBQLN2, has been implicated in numerous neurodegenerative diseases including ALS/FTD. UBQLN2 typically resides in the cytoplasm but in disease can translocate to the nucleus, as in Huntington's disease where it promotes the clearance of mutant Huntingtin. How UBQLN2 translocates to the nucleus and clears aberrant nuclear proteins, however, is not well understood. In a mass spectrometry screen to discover UBQLN2 interactors, we identified a family of small (13 kDa), highly homologous uncharacterized proteins, RTL8, and confirmed the interaction between UBQLN2 and RTL8 both in vitro using recombinant proteins and in vivo using mouse brain tissue. Under endogenous and overexpressed conditions, RTL8 localizes to nucleoli. When co-expressed with UBQLN2, RTL8 promotes nuclear translocation of UBQLN2. RTL8 also facilitates UBQLN2's nuclear translocation during heat shock. UBQLN2 and RTL8 colocalize within ubiquitin-enriched subnuclear structures containing PQC components. The robust effect of RTL8 on the nuclear translocation and subnuclear localization of UBQLN2 does not extend to the other brain-expressed ubiquilins, UBQLN1 and UBQLN4. Moreover, compared to UBQLN1 and UBQLN4, UBQLN2 preferentially stabilizes RTL8 levels in human cell lines and in mouse brain, supporting functional heterogeneity among UBQLNs. As a novel UBQLN2 interactor that recruits UBQLN2 to specific nuclear compartments, RTL8 may regulate UBQLN2 function in nuclear protein quality control.
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Affiliation(s)
- Harihar Milaganur Mohan
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.,Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | | | - Amit Pithadia
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Emily V Crowley
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Regina Pacitto
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Nathaniel Safren
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA.,Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Bryce Trotter
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Chengxin Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Xiaogen Zhou
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109-2200, USA
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA. .,Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
| | - Lisa M Sharkey
- Department of Neurology, University of Michigan, Ann Arbor, MI, 48109-2200, USA. .,Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109-2200, USA.
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11
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TDP-43 pathology: from noxious assembly to therapeutic removal. Prog Neurobiol 2022; 211:102229. [DOI: 10.1016/j.pneurobio.2022.102229] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/08/2021] [Accepted: 01/26/2022] [Indexed: 02/08/2023]
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12
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Bonifacino T, Zerbo RA, Balbi M, Torazza C, Frumento G, Fedele E, Bonanno G, Milanese M. Nearly 30 Years of Animal Models to Study Amyotrophic Lateral Sclerosis: A Historical Overview and Future Perspectives. Int J Mol Sci 2021; 22:ijms222212236. [PMID: 34830115 PMCID: PMC8619465 DOI: 10.3390/ijms222212236] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, multigenic, multifactorial, and non-cell autonomous neurodegenerative disease characterized by upper and lower motor neuron loss. Several genetic mutations lead to ALS development and many emerging gene mutations have been discovered in recent years. Over the decades since 1990, several animal models have been generated to study ALS pathology including both vertebrates and invertebrates such as yeast, worms, flies, zebrafish, mice, rats, guinea pigs, dogs, and non-human primates. Although these models show different peculiarities, they are all useful and complementary to dissect the pathological mechanisms at the basis of motor neuron degeneration and ALS progression, thus contributing to the development of new promising therapeutics. In this review, we describe the up to date and available ALS genetic animal models, classified by the different genetic mutations and divided per species, pointing out their features in modeling, the onset and progression of the pathology, as well as their specific pathological hallmarks. Moreover, we highlight similarities, differences, advantages, and limitations, aimed at helping the researcher to select the most appropriate experimental animal model, when designing a preclinical ALS study.
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Affiliation(s)
- Tiziana Bonifacino
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Genoa, Italy
| | - Roberta Arianna Zerbo
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Matilde Balbi
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Carola Torazza
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Giulia Frumento
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Ernesto Fedele
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
- Correspondence:
| | - Giambattista Bonanno
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Marco Milanese
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Genoa, Italy
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13
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Higgins NR, Greenslade JE, Wu JJ, Miranda E, Galliciotti G, Monteiro MJ. Serpin neuropathology in the P497S UBQLN2 mouse model of ALS/FTD. Brain Pathol 2021; 31:e12948. [PMID: 33780087 PMCID: PMC8387369 DOI: 10.1111/bpa.12948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/17/2021] [Accepted: 03/08/2021] [Indexed: 01/12/2023] Open
Abstract
Accumulating evidence suggests X-linked dominant mutations in UBQLN2 cause amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD) through both loss- and gain-of-function mechanisms. However, the mechanisms by which the mutations cause disease are still unclear. The goal of the study was to uncover the possible pathomechanism(s) by which UBQLN2 mutations cause ALS/FTD. An analysis of proteomic changes in neuronal tissue was used to identify proteins with altered accumulation in the P497S UBQLN2 transgenic mouse model of ALS/FTD. We then used immunocytochemistry and biochemical techniques to confirm protein changes in the mutant P497S mice. Additionally, we used cell lines inactivated of UBQLN2 expression to determine whether its loss underlies the alteration in the proteins seen in P497S mice. The proteome screen identified a dramatic alteration of serine protease inhibitor (serpin) proteins in the mutant P497S animals. Double immunofluorescent staining of brain and spinal cord tissues of the mutant and control mice revealed an age-dependent change in accumulation of Serpin A1, C1, and I1 in puncta whose staining colocalized with UBQLN2 puncta in the mutant P497S mice. Serpin A1 aggregation in P497S animals was confirmed by biochemical extraction and filter retardation assays. A similar phenomenon of serpin protein aggregation was found in HeLa and NSC34 motor neuron cells with inactivated UBQLN2 expression. We found aberrant aggregation of serpin proteins, particularly Serpin A1, in the brain and spinal cord of the P497S UBQLN2 mouse model of ALS/FTD. Similar aggregation of serpin proteins was found in UBQLN2 knockout cells suggesting that serpin aggregation in the mutant P497S animals may stem from loss of UBQLN2 function. Because serpin aggregation is known to cause disease through both loss- and gain-of-function mechanisms, we speculate that their accumulation in the P497S mouse model of ALS/FTD may contribute to disease pathogenesis through similar mechanism(s).
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Affiliation(s)
- Nicole R. Higgins
- Program in Molecular MedicineUniversity of Maryland School of MedicineBaltimoreMDUSA
- Center for Biomedical Engineering and TechnologyDepartment of Anatomy and NeurobiologyUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Jessie E. Greenslade
- Center for Biomedical Engineering and TechnologyDepartment of Anatomy and NeurobiologyUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Josephine J. Wu
- Center for Biomedical Engineering and TechnologyDepartment of Anatomy and NeurobiologyUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Elena Miranda
- Department of Biology and Biotechnologies ‘Charles Darwin’Pasteur Institute – Cenci Bolognetti FoundationSapienza University of RomeRomeItaly
| | - Giovanna Galliciotti
- Institute of NeuropathologyUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Mervyn J. Monteiro
- Program in Molecular MedicineUniversity of Maryland School of MedicineBaltimoreMDUSA
- Center for Biomedical Engineering and TechnologyDepartment of Anatomy and NeurobiologyUniversity of Maryland School of MedicineBaltimoreMDUSA
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14
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Rana T, Behl T, Sehgal A, Mehta V, Singh S, Bhatia S, Al-Harrasi A, Bungau S. Exploring the Role of Autophagy Dysfunction in Neurodegenerative Disorders. Mol Neurobiol 2021; 58:4886-4905. [PMID: 34212304 DOI: 10.1007/s12035-021-02472-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/21/2021] [Indexed: 12/12/2022]
Abstract
Autophagy is a catabolic pathway by which misfolded proteins or damaged organelles are engulfed by autophagosomes and then transported to lysosomes for degradation. Recently, a great improvement has been done to explain the molecular mechanisms and roles of autophagy in several important cellular metabolic processes. Besides being a vital clearance pathway or a cell survival pathway in response to different stresses, autophagy dysfunction, either upregulated or down-regulated, has been suggested to be linked with numerous neurodegenerative disorders like Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic lateral sclerosis. Impairment at different stages of autophagy results in the formation of large protein aggregates and damaged organelles, which leads to the onset and progression of different neurodegenerative disorders. This article elucidates the recent progress about the role of autophagy in neurodegenerative disorders and explains how autophagy dysfunction is linked with the pathogenesis of such disorders as well as the novel potential autophagy-associated therapies for treating them.
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Affiliation(s)
- Tarapati Rana
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
- Government Pharmacy College, Seraj, Mandi, Himachal Pradesh, India
| | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Punjab, India.
| | - Aayush Sehgal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Vineet Mehta
- Government College of Pharmacy, Rohru, Distt. Shimla, Himachal Pradesh, India
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Saurabh Bhatia
- Amity Institute of Pharmacy, Amity University, Haryana, India
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Ahmed Al-Harrasi
- Natural & Medical Sciences Research Centre, University of Nizwa, Nizwa, Oman
| | - Simona Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
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15
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Lin BC, Phung TH, Higgins NR, Greenslade JE, Prado MA, Finley D, Karbowski M, Polster BM, Monteiro MJ. ALS/FTD mutations in UBQLN2 are linked to mitochondrial dysfunction through loss-of-function in mitochondrial protein import. Hum Mol Genet 2021; 30:1230-1246. [PMID: 33891006 PMCID: PMC8212775 DOI: 10.1093/hmg/ddab116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 01/12/2023] Open
Abstract
UBQLN2 mutations cause amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD), but the pathogenic mechanisms by which they cause disease remain unclear. Proteomic profiling identified 'mitochondrial proteins' as comprising the largest category of protein changes in the spinal cord (SC) of the P497S UBQLN2 mouse model of ALS/FTD. Immunoblots confirmed P497S animals have global changes in proteins predictive of a severe decline in mitochondrial health, including oxidative phosphorylation (OXPHOS), mitochondrial protein import and network dynamics. Functional studies confirmed mitochondria purified from the SC of P497S animals have age-dependent decline in nearly all steps of OXPHOS. Mitochondria cristae deformities were evident in spinal motor neurons of aged P497S animals. Knockout (KO) of UBQLN2 in HeLa cells resulted in changes in mitochondrial proteins and OXPHOS activity similar to those seen in the SC. KO of UBQLN2 also compromised targeting and processing of the mitochondrial import factor, TIMM44, resulting in accumulation in abnormal foci. The functional OXPHOS deficits and TIMM44-targeting defects were rescued by reexpression of WT UBQLN2 but not by ALS/FTD mutant UBQLN2 proteins. In vitro binding assays revealed ALS/FTD mutant UBQLN2 proteins bind weaker with TIMM44 than WT UBQLN2 protein, suggesting that the loss of UBQLN2 binding may underlie the import and/or delivery defect of TIMM44 to mitochondria. Our studies indicate a potential key pathogenic disturbance in mitochondrial health caused by UBQLN2 mutations.
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Affiliation(s)
- Brian C Lin
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Trong H Phung
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Nicole R Higgins
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jessie E Greenslade
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Miguel A Prado
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Daniel Finley
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Mariusz Karbowski
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Brian M Polster
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anesthesiology, Center for Shock, Trauma and Anesthesiology Research, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mervyn J Monteiro
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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16
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Riley JF, Fioramonti PJ, Rusnock AK, Hehnly H, Castañeda CA. ALS-linked mutations impair UBQLN2 stress-induced biomolecular condensate assembly in cells. J Neurochem 2021; 159:145-155. [PMID: 34129687 DOI: 10.1111/jnc.15453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 05/30/2021] [Accepted: 06/13/2021] [Indexed: 11/28/2022]
Abstract
Mutations in Ubiquilin-2 (UBQLN2), a ubiquitin-binding shuttle protein involved in several protein quality control processes, can lead to amyotrophic lateral sclerosis (ALS). We previously found that wild-type UBQLN2 forms dynamic, membraneless biomolecular condensates upon cellular stress, and undergoes liquid-liquid phase separation in vitro. However, the impact of ALS-linked mutations on UBQLN2 condensate formation in cells is unknown. Here, we employ live-cell imaging and photokinetic analysis to investigate how five patient-derived ALS-linked mutations in UBQLN2 impact stress-induced UBQLN2 condensate assembly and condensate material properties. Both wild-type and mutant UBQLN2 condensates are generally cytoplasmic and liquid-like. However, cells transfected with mutant UBQLN2 contain fewer stress-induced UBQLN2 condensates than those with wild-type UBQLN2. Most strikingly, exogenously expressed P506T UBQLN2 forms the lowest number of stress-induced condensates of all UBQLN2 mutants, and these condensates are significantly smaller than those of wild-type UBQLN2. Fluorescence recovery after photobleaching (FRAP) analysis of UBQLN2 condensates revealed higher immobile fractions for UBQLN2 mutants, especially P506T. P497S and P497H mutations differentially impact condensate properties, demonstrating that the effects of ALS-linked mutations are both position- and amino acid-dependent. Collectively, our data show that disease mutations hinder assembly and alter viscoelastic properties of stress-induced UBQLN2 condensates, potentially leading to aggregates commonly observed in ALS.
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Affiliation(s)
- Julia F Riley
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA.,Department of Chemistry, Syracuse University, Syracuse, NY, 13244, USA.,Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY, 13244, USA
| | | | - Amber K Rusnock
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - Heidi Hehnly
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA
| | - Carlos A Castañeda
- Department of Biology, Syracuse University, Syracuse, NY, 13244, USA.,Department of Chemistry, Syracuse University, Syracuse, NY, 13244, USA.,Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY, 13244, USA
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17
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UBQLN2-HSP70 axis reduces poly-Gly-Ala aggregates and alleviates behavioral defects in the C9ORF72 animal model. Neuron 2021; 109:1949-1962.e6. [PMID: 33991504 DOI: 10.1016/j.neuron.2021.04.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/09/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
Expansion of a hexanucleotide repeat GGGGCC (G4C2) in the intron of the C9ORF72 gene is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9-ALS/FTD). Transcripts carrying G4C2 repeat expansions generate neurotoxic dipeptide repeat (DPR) proteins, including poly-Gly-Ala (poly-GA), which tends to form protein aggregates. Here, we demonstrate that UBQLN2, another ALS/FTD risk factor, is recruited to reduce poly-GA aggregates and alleviate poly-GA-induced neurotoxicity. UBQLN2 could recognize HSP70 ubiquitination, which facilitates the UBQLN2-HSP70-GA complex formation and promotes poly-GA degradation. ALS/FTD-related UBQLN2 mutants fail to bind HSP70 and clear poly-GA aggregates. Disruption of the interaction between UBQLN2 and HSP70 inhibits poly-GA aggregation in C9-ALS/FTD iPSC-derived neurons. Finally, enhancing HSP70 by the chemical compound 17AAG at the adult stage mitigates behavioral defects in poly-GA animals. Our findings suggest a critical role of the UBQLN2-HSP70 axis in protein aggregate clearance in C9-ALS/FTD.
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18
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Saxton AD, Kraemer BC. Human Ubiquilin 2 and TDP-43 co-pathology drives neurodegeneration in transgenic C. elegans. G3-GENES GENOMES GENETICS 2021; 11:6272515. [PMID: 33963840 DOI: 10.1093/g3journal/jkab158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/01/2021] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a debilitating, fatal neurodegenerative disease that causes rapid muscle wasting. It shares a spectrum of symptoms and pathology with frontotemporal lobar degeneration (FTLD). These diseases are caused by aberrant activity of a set of proteins including TDP-43 and UBIQUILIN-2 (UBQLN2). UBQLN2 encodes an ubiquitin-like adaptor protein involved in the ubiquitin-proteasome protein degradation pathway. Mutations in the PXX domain of UBQLN2 cause familial ALS. UBQLN2 aggregates in skein-like inclusions with other ALS and FTLD associated proteins including TDP-43 and ubiquitin. To facilitate further investigation of UBQLN2-mediated mechanisms of neurodegeneration, we made Caenorhabditis elegans transgenic lines pan-neuronally expressing human UBQLN2 cDNAs carrying either the wild-type UBQLN2 sequence or UBQLN2 with ALS causing mutations. Transgenic animals exhibit motor dysfunction accompanied by neurodegeneration of GABAergic motor neurons. At low levels of UBQLN2 expression, wild-type UBQLN2 causes significant motor impairment and neurodegeneration that is exacerbated by ALS associated mutations in UBQLN2. At higher levels of UBQLN2 expression, both wild-type and ALS mutated versions of UBQLN2 cause severe impairment. Molecular genetic investigation revealed that UBQLN2 dependent locomotor defects do not require the involvement of the endogenous homolog of TDP-43 in C. elegans (tdp-1). However, co-expression of wild-type human TDP-43 exacerbates UBQLN2 deficits. This model of UBQLN2-mediated neurodegeneration may be useful for further mechanistic investigation into the molecular cascades driving neurodegeneration in ALS and ALS-FTLD.
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Affiliation(s)
- Aleen D Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, 98108, United States of America
| | - Brian C Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, 98108, United States of America; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA; Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, Washington 98195, USA; Department of Pathology, University of Washington School of Medicine, Seattle, Washington 98195, USA
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19
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Impaired 26S Proteasome Assembly Precedes Neuronal Loss in Mutant UBQLN2 Rats. Int J Mol Sci 2021; 22:ijms22094319. [PMID: 33919255 PMCID: PMC8122323 DOI: 10.3390/ijms22094319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/15/2021] [Accepted: 04/19/2021] [Indexed: 11/17/2022] Open
Abstract
Proteasomal dysfunction is known to be associated with amyotrophic lateral sclerosis and frontotemporal degeneration (ALS/FTD). Our previous reports have shown that a mutant form of ubiquilin-2 (UBQLN2) linked to ALS/FTD leads to neurodegeneration accompanied by accumulations of the proteasome subunit Rpt1 in transgenic rats, but the precise pathogenic mechanisms of how this mutation impairs the proteasome remains to be elucidated. Here, we reveal that this UBQLN2 mutation in rats disrupted the proteasome integrity prior to neurodegeneration, that it dissociated the 26S proteasome in vitro, and that its depletion did not affect 26S proteasome assembly. During both disease progression and in an age-dependent manner, we found that proteasome subunits were translocated to the nucleus, including both of the 20S core particles (PSMA1 and PSMB7) and the 19S regulatory particles (Rpt1 and Rpn1), suggesting that defective proteasome function may result from the proteasome-subunit mislocalization. Taken together, the present data demonstrate that impaired proteasome assembly is an early event in the pathogenesis of UBQLN2-associated neurodegeneration in mutant UBQLN2 rats.
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20
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Yamaguchi M, Lee IS, Jantrapirom S, Suda K, Yoshida H. Drosophila models to study causative genes for human rare intractable neurological diseases. Exp Cell Res 2021; 403:112584. [PMID: 33812867 DOI: 10.1016/j.yexcr.2021.112584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 12/11/2022]
Abstract
Drosophila is emerging as a convenient model for investigating human diseases. Functional homologues of almost 75% of human disease-related genes are found in Drosophila. Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease that causes defects in motoneurons. Charcot-Marie-Tooth disease (CMT) is one of the most commonly found inherited neuropathies affecting both motor and sensory neurons. No effective therapy has been established for either of these diseases. In this review, after overviewing ALS, Drosophila models targeting several ALS-causing genes, including TDP-43, FUS and Ubiquilin2, are described with their genetic interactants. Then, after overviewing CMT, examples of Drosophila models targeting several CMT-causing genes, including mitochondria-related genes and FIG 4, are also described with their genetic interactants. In addition, we introduce Sotos syndrome caused by mutations in the epigenetic regulator gene NSD1. Lastly, several genes and pathways that commonly interact with ALS- and/or CMT-causing genes are described. In the case of ALS and CMT that have many causative genes, it may be not practical to perform gene therapy for each of the many disease-causing genes. The possible uses of the common genes and pathways as novel diagnosis markers and effective therapeutic targets are discussed.
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Affiliation(s)
- Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan; Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Seika-cho, Kyoto, 619-0237, Japan
| | - Im-Soon Lee
- Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea
| | - Salinee Jantrapirom
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kojiro Suda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
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21
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Ngo ST, Wang H, Henderson RD, Bowers C, Steyn FJ. Ghrelin as a treatment for amyotrophic lateral sclerosis. J Neuroendocrinol 2021; 33:e12938. [PMID: 33512025 DOI: 10.1111/jne.12938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/27/2022]
Abstract
Ghrelin is a gut hormone best known for its role in regulating appetite and stimulating the secretion of the anabolic hormone growth hormone (GH). However, there is considerable evidence to show wider-ranging biological actions of ghrelin that favour improvements in cellular and systemic metabolism, as well as neuroprotection. Activation of these ghrelin-mediated pathways may alleviate pathogenic processes that are assumed to contribute to accelerated progression of disease in patients with neurodegenerative disease. Here, we provide a brief overview on the history of discoveries that led to the identification of ghrelin. Focussing on the neurodegenerative disease amyotrophic lateral sclerosis (ALS), we also present an overview of emerging evidence that suggests that ghrelin and ghrelin mimetics may serve as potential therapies for the treatment of ALS. Given that ALS is a highly heterogeneous disease, where multiple disease mechanisms contribute to variability in disease onset and rate of disease progression, we speculate that the wide-ranging biological actions of ghrelin might offer therapeutic benefit through modulating multiple disease-relevant processes observed in ALS. Expanding on the well-known actions of ghrelin in regulating food intake and GH secretion, we consider the potential of ghrelin-mediated pathways in improving body weight regulation, metabolism and the anabolic and neuroprotective actions of GH and insulin-like growth factor-1 (IGF-1). This is of clinical significance because loss of body weight, impairments in systemic and cellular metabolism, and reductions in IGF-1 are associated with faster disease progression and worse disease outcome in patients with ALS.
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Affiliation(s)
- Shyuan T Ngo
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Hao Wang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Robert D Henderson
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Cyril Bowers
- Department of Internal Medicine, Tulane University Health Sciences Centre, New Orleans, LA, USA
| | - Frederik J Steyn
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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22
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de Jongh R, Spijkers XM, Pasteuning-Vuhman S, Vulto P, Pasterkamp RJ. Neuromuscular junction-on-a-chip: ALS disease modeling and read-out development in microfluidic devices. J Neurochem 2021; 157:393-412. [PMID: 33382092 DOI: 10.1111/jnc.15289] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal and progressive neurodegenerative disease affecting upper and lower motor neurons with no cure available. Clinical and animal studies reveal that the neuromuscular junction (NMJ), a synaptic connection between motor neurons and skeletal muscle fibers, is highly vulnerable in ALS and suggest that NMJ defects may occur at the early stages of the disease. However, mechanistic insight into how NMJ dysfunction relates to the onset and progression of ALS is incomplete, which hampers therapy development. This is, in part, caused by a lack of robust in vitro models. The ability to combine microfluidic and induced pluripotent stem cell (iPSC) technologies has opened up new avenues for studying molecular and cellular ALS phenotypes in vitro. Microfluidic devices offer several advantages over traditional culture approaches when modeling the NMJ, such as the spatial separation of different cell types and increased control over the cellular microenvironment. Moreover, they are compatible with 3D cell culture, which enhances NMJ functionality and maturity. Here, we review how microfluidic technology is currently being employed to develop more reliable in vitro NMJ models. To validate and phenotype such models, various morphological and functional read-outs have been developed. We describe and discuss the relevance of these read-outs and specifically illustrate how these read-outs have enhanced our understanding of NMJ pathology in ALS. Finally, we share our view on potential future directions and challenges.
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Affiliation(s)
- Rianne de Jongh
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Xandor M Spijkers
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands.,Mimetas B.V., Organ-on-a-chip Company, Leiden, The Netherlands
| | - Svetlana Pasteuning-Vuhman
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Paul Vulto
- Mimetas B.V., Organ-on-a-chip Company, Leiden, The Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
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23
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Ma P, Li Y, Wang H, Mao B. Haploinsufficiency of the TDP43 ubiquitin E3 ligase RNF220 leads to ALS-like motor neuron defects in the mouse. J Mol Cell Biol 2021; 13:374-382. [PMID: 33386850 PMCID: PMC8373269 DOI: 10.1093/jmcb/mjaa072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/16/2020] [Accepted: 10/04/2020] [Indexed: 11/14/2022] Open
Abstract
TDP43 pathology is seen in a large majority of amyotrophic lateral sclerosis (ALS) cases, suggesting a central pathogenic role of this regulatory protein. Clarifying the molecular mechanism controlling TDP43 stability and subcellular location might provide important insights into ALS therapy. The ubiquitin E3 ligase RNF220 is involved in different neural developmental processes through various molecular targets in the mouse. Here, we report that the RNF220+/− mice showed progressively decreasing mobility to different extents, some of which developed typical ALS pathological characteristics in spinal motor neurons, including TDP43 cytoplasmic accumulation, atrocytosis, muscle denervation, and atrophy. Mechanistically, RNF220 interacts with TDP43 in vitro and in vivo and promotes its polyubiquitination and proteasomal degradation. In conclusion, we propose that RNF220 might be a modifier of TDP43 function in vivo and contribute to TDP43 pathology in neurodegenerative disease like ALS.
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Affiliation(s)
- Pengcheng Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yuwei Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Huishan Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
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24
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Whiteley AM, Prado MA, de Poot SAH, Paulo JA, Ashton M, Dominguez S, Weber M, Ngu H, Szpyt J, Jedrychowski MP, Easton A, Gygi SP, Kurz T, Monteiro MJ, Brown EJ, Finley D. Global proteomics of Ubqln2-based murine models of ALS. J Biol Chem 2020; 296:100153. [PMID: 33277362 PMCID: PMC7873701 DOI: 10.1074/jbc.ra120.015960] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/21/2020] [Accepted: 12/04/2020] [Indexed: 12/12/2022] Open
Abstract
Familial neurodegenerative diseases commonly involve mutations that result in either aberrant proteins or dysfunctional components of the proteolytic machinery that act on aberrant proteins. UBQLN2 is a ubiquitin receptor of the UBL/UBA family that binds the proteasome through its ubiquitin-like domain and is thought to deliver ubiquitinated proteins to proteasomes for degradation. UBQLN2 mutations result in familial amyotrophic lateral sclerosis (ALS)/frontotemporal dementia in humans through an unknown mechanism. Quantitative multiplexed proteomics was used to provide for the first time an unbiased and global analysis of the role of Ubqln2 in controlling the composition of the proteome. We studied several murine models of Ubqln2-linked ALS and also generated Ubqln2 null mutant mice. We identified impacts of Ubqln2 on diverse physiological pathways, most notably serotonergic signaling. Interestingly, we observed an upregulation of proteasome subunits, suggesting a compensatory response to diminished proteasome output. Among the specific proteins whose abundance is linked to UBQLN2 function, the strongest hits were the ubiquitin ligase TRIM32 and two retroelement-derived proteins, PEG10 and CXX1B. Cycloheximide chase studies using induced human neurons and HEK293 cells suggested that PEG10 and TRIM32 are direct clients. Although UBQLN2 directs the degradation of multiple proteins via the proteasome, it surprisingly conferred strong protection from degradation on the Gag-like protein CXX1B, which is expressed from the same family of retroelement genes as PEG10. In summary, this study charts the proteomic landscape of ALS-related Ubqln2 mutants and identifies candidate client proteins that are altered in vivo in disease models and whose degradation is promoted by UBQLN2.
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Affiliation(s)
| | - Miguel A Prado
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Marissa Ashton
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Sara Dominguez
- Department of Neuroscience, Genentech Inc, South San Francisco, California, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc, South San Francisco, California, USA
| | - Hai Ngu
- Department of Pathology, Genentech Inc, South San Francisco, California, USA
| | - John Szpyt
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Mark P Jedrychowski
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Amy Easton
- Department of Neuroscience, Genentech Inc, South San Francisco, California, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Thimo Kurz
- Henry Wellcome Lab of Cell Biology, College of Medical, Veterinary and Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Mervyn J Monteiro
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland Medical School, Baltimore, Maryland, USA
| | - Eric J Brown
- Department of Immunology and Infectious Diseases, Genentech Inc, South San Francisco, California, USA
| | - Daniel Finley
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA.
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25
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Wang S, Tatman M, Monteiro MJ. Overexpression of UBQLN1 reduces neuropathology in the P497S UBQLN2 mouse model of ALS/FTD. Acta Neuropathol Commun 2020; 8:164. [PMID: 33028421 PMCID: PMC7539388 DOI: 10.1186/s40478-020-01039-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/22/2020] [Indexed: 12/14/2022] Open
Abstract
Missense mutations in UBQLN2 cause X-linked dominant inheritance of amyotrophic lateral sclerosis with frontotemporal dementia (ALS/FTD). UBQLN2 belongs to a family of four highly homologous proteins expressed in humans that play diverse roles in maintaining proteostasis, but whether one isoform can substitute for another is not known. Here, we tested whether overexpression of UBQLN1 can alleviate disease in the P497S UBQLN2 mouse model of ALS/FTD by crossing transgenic (Tg) mouse lines expressing the two proteins and characterizing the resulting genotypes using a battery of pathologic and behavioral tests. The pathologic findings revealed UBQLN1 overexpression dramatically reduced the burden of UBQLN2 inclusions, neuronal loss and disturbances in proteostasis in double Tg mice compared to single P497S Tg mice. The beneficial effects of UBQLN1 overexpression were primarily confirmed by behavioral improvements seen in rotarod performance and grip strength in male, but not female mice. Paradoxically, although UBQLN1 overexpression reduced pathologic signatures of disease in P497S Tg mice, female mice had larger percentage of body weight loss than males, and this correlated with a corresponding lack of behavioral improvements in the females. These findings lead us to speculate that methods to upregulate UBQLN1 expression may reduce pathogenicity caused by UBQLN2 mutations, but may also lead to gender-specific outcomes that will have to be carefully weighed with the therapeutic benefits of UBQLN1 upregulation.
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26
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Zheng T, Yang Y, Castañeda CA. Structure, dynamics and functions of UBQLNs: at the crossroads of protein quality control machinery. Biochem J 2020; 477:3471-3497. [PMID: 32965492 PMCID: PMC7737201 DOI: 10.1042/bcj20190497] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/23/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022]
Abstract
Cells rely on protein homeostasis to maintain proper biological functions. Dysregulation of protein homeostasis contributes to the pathogenesis of many neurodegenerative diseases and cancers. Ubiquilins (UBQLNs) are versatile proteins that engage with many components of protein quality control (PQC) machinery in cells. Disease-linked mutations of UBQLNs are most commonly associated with amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and other neurodegenerative disorders. UBQLNs play well-established roles in PQC processes, including facilitating degradation of substrates through the ubiquitin-proteasome system (UPS), autophagy, and endoplasmic-reticulum-associated protein degradation (ERAD) pathways. In addition, UBQLNs engage with chaperones to sequester, degrade, or assist repair of misfolded client proteins. Furthermore, UBQLNs regulate DNA damage repair mechanisms, interact with RNA-binding proteins (RBPs), and engage with cytoskeletal elements to regulate cell differentiation and development. Important to the myriad functions of UBQLNs are its multidomain architecture and ability to self-associate. UBQLNs are linked to numerous types of cellular puncta, including stress-induced biomolecular condensates, autophagosomes, aggresomes, and aggregates. In this review, we focus on deciphering how UBQLNs function on a molecular level. We examine the properties of oligomerization-driven interactions among the structured and intrinsically disordered segments of UBQLNs. These interactions, together with the knowledge from studies of disease-linked mutations, provide significant insights to UBQLN structure, dynamics and function.
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Affiliation(s)
- Tongyin Zheng
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, U.S.A
| | - Yiran Yang
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, U.S.A
| | - Carlos A. Castañeda
- Department of Chemistry, Syracuse University, Syracuse, NY 13244, U.S.A
- Departments of Biology and Chemistry, Syracuse University, Syracuse, NY 13244, U.S.A
- Bioinspired Institute, and the Interdisciplinary Neuroscience Program, Syracuse University, Syracuse, NY 13244, U.S.A
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27
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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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28
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Solomon DA, Mitchell JC, Salcher-Konrad MT, Vance CA, Mizielinska S. Review: Modelling the pathology and behaviour of frontotemporal dementia. Neuropathol Appl Neurobiol 2020; 45:58-80. [PMID: 30582188 DOI: 10.1111/nan.12536] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/16/2018] [Indexed: 12/11/2022]
Abstract
Frontotemporal dementia (FTD) encompasses a collection of clinically and pathologically diverse neurological disorders. Clinical features of behavioural and language dysfunction are associated with neurodegeneration, predominantly of frontal and temporal cortices. Over the past decade, there have been significant advances in the understanding of the genetic aetiology and neuropathology of FTD which have led to the creation of various disease models to investigate the molecular pathways that contribute to disease pathogenesis. The generation of in vivo models of FTD involves either targeting genes with known disease-causative mutations such as GRN and C9orf72 or genes encoding proteins that form the inclusions that characterize the disease pathologically, such as TDP-43 and FUS. This review provides a comprehensive summary of the different in vivo model systems used to understand pathomechanisms in FTD, with a focus on disease models which reproduce aspects of the wide-ranging behavioural phenotypes seen in people with FTD. We discuss the emerging disease pathways that have emerged from these in vivo models and how this has shaped our understanding of disease mechanisms underpinning FTD. We also discuss the challenges of modelling the complex clinical symptoms shown by people with FTD, the confounding overlap with features of motor neuron disease, and the drive to make models more disease-relevant. In summary, in vivo models can replicate many pathological and behavioural aspects of clinical FTD, but robust and thorough investigations utilizing shared features and variability between disease models will improve the disease-relevance of findings and thus better inform therapeutic development.
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Affiliation(s)
- D A Solomon
- UK Dementia Research Institute, King's College London, London, Camberwell, UK.,Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - J C Mitchell
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - M-T Salcher-Konrad
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - C A Vance
- Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
| | - S Mizielinska
- UK Dementia Research Institute, King's College London, London, Camberwell, UK.,Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, Camberwell, UK
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29
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Suk TR, Rousseaux MWC. The role of TDP-43 mislocalization in amyotrophic lateral sclerosis. Mol Neurodegener 2020; 15:45. [PMID: 32799899 PMCID: PMC7429473 DOI: 10.1186/s13024-020-00397-1] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/07/2020] [Indexed: 02/07/2023] Open
Abstract
Since its discovery as a primary component in cytoplasmic aggregates in post-mortem tissue of patients with Amyotrophic Lateral Sclerosis (ALS), TAR DNA Binding Protein 43 kDa (TDP-43) has remained a central focus to understand the disease. TDP-43 links both familial and sporadic forms of ALS as mutations are causative for disease and cytoplasmic aggregates are a hallmark of nearly all cases, regardless of TDP-43 mutational status. Research has focused on the formation and consequences of cytosolic protein aggregates as drivers of ALS pathology through both gain- and loss-of-function mechanisms. Not only does aggregation sequester the normal function of TDP-43, but these aggregates also actively block normal cellular processes inevitably leading to cellular demise in a short time span. Although there may be some benefit to therapeutically targeting TDP-43 aggregation, this step may be too late in disease development to have substantial therapeutic benefit. However, TDP-43 pathology appears to be tightly linked with its mislocalization from the nucleus to the cytoplasm, making it difficult to decouple the consequences of nuclear-to-cytoplasmic mislocalization from protein aggregation. Studies focusing on the effects of TDP-43 mislocalization have demonstrated both gain- and loss-of-function consequences including altered splicing regulation, over responsiveness to cellular stressors, increases in DNA damage, and transcriptome-wide changes. Additionally, mutations in TARDBP confer a baseline increase in cytoplasmic TDP-43 thus suggesting that small changes in the subcellular localization of TDP-43 could in fact drive early pathology. In this review, we bring forth the theme of protein mislocalization as a key mechanism underlying ALS, by highlighting the importance of maintaining subcellular proteostasis along with the gain- and loss-of-functional consequences when TDP-43 localization is dysregulated. Additional research, focusing on early events in TDP-43 pathogenesis (i.e. to the protein mislocalization stage) will provide insight into disease mechanisms, therapeutic targets, and novel biomarkers for ALS.
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Affiliation(s)
- Terry R. Suk
- University of Ottawa Brain and Mind Research Institute, Ottawa, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Maxime W. C. Rousseaux
- University of Ottawa Brain and Mind Research Institute, Ottawa, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
- Eric Poulin Center for Neuromuscular Diseases, Ottawa, Canada
- Ottawa Institute of Systems Biology, Ottawa, Canada
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30
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Sharkey LM, Sandoval-Pistorius SS, Moore SJ, Gerson JE, Komlo R, Fischer S, Negron-Rios KY, Crowley EV, Padron F, Patel R, Murphy GG, Paulson HL. Modeling UBQLN2-mediated neurodegenerative disease in mice: Shared and divergent properties of wild type and mutant UBQLN2 in phase separation, subcellular localization, altered proteostasis pathways, and selective cytotoxicity. Neurobiol Dis 2020; 143:105016. [PMID: 32653673 DOI: 10.1016/j.nbd.2020.105016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/26/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
The ubiquitin-binding proteasomal shuttle protein UBQLN2 is implicated in common neurodegenerative disorders due to its accumulation in disease-specific aggregates and, when mutated, directly causes familial frontotemporal dementia/amyotrophic lateral sclerosis (FTD/ALS). Like other proteins linked to FTD/ALS, UBQLN2 undergoes phase separation to form condensates. The relationship of UBQLN2 phase separation and accumulation to neurodegeneration, however, remains uncertain. Employing biochemical, neuropathological and behavioral assays, we studied the impact of overexpressing WT or mutant UBQLN2 in the CNS of transgenic mice. Expression of UBQLN2 harboring a pathogenic mutation (P506T) elicited profound and widespread intraneuronal inclusion formation and aggregation without prominent neurodegenerative or behavioral changes. Both WT and mutant UBQLN2 formed ubiquitin- and P62-positive inclusions in neurons, supporting the view that UBQLN2 is intrinsically prone to phase separate, with the size, shape and frequency of inclusions depending on expression level and the presence or absence of a pathogenic mutation. Overexpression of WT or mutant UBQLN2 resulted in a dose-dependent decrease in levels of a key interacting chaperone, HSP70, as well as dose-dependent profound degeneration of the retina. We conclude that, at least in mice, robust aggregation of a pathogenic form of UBQLN2 is insufficient to cause neuronal loss recapitulating that of human FTD/ALS. Our results nevertheless support the view that altering the normal cellular balance of UBQLN2, whether wild type or mutant protein, has deleterious effects on cells of the CNS and retina that likely reflect perturbations in ubiquitin-dependent protein homeostasis.
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Affiliation(s)
- Lisa M Sharkey
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America.
| | - Stephanie S Sandoval-Pistorius
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Shannon J Moore
- Michigan Neuroscience Institute and Department of Physiology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Julia E Gerson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Robert Komlo
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Svetlana Fischer
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Keyshla Y Negron-Rios
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Emily V Crowley
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Francisco Padron
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Ronak Patel
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Geoffrey G Murphy
- Michigan Neuroscience Institute and Department of Physiology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200, United States of America.
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31
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Wu JJ, Cai A, Greenslade JE, Higgins NR, Fan C, Le NTT, Tatman M, Whiteley AM, Prado MA, Dieriks BV, Curtis MA, Shaw CE, Siddique T, Faull RLM, Scotter EL, Finley D, Monteiro MJ. ALS/FTD mutations in UBQLN2 impede autophagy by reducing autophagosome acidification through loss of function. Proc Natl Acad Sci U S A 2020; 117:15230-15241. [PMID: 32513711 PMCID: PMC7334651 DOI: 10.1073/pnas.1917371117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mutations in UBQLN2 cause amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and other neurodegenerations. However, the mechanism by which the UBQLN2 mutations cause disease remains unclear. Alterations in proteins involved in autophagy are prominent in neuronal tissue of human ALS UBQLN2 patients and in a transgenic P497S UBQLN2 mouse model of ALS/FTD, suggesting a pathogenic link. Here, we show UBQLN2 functions in autophagy and that ALS/FTD mutant proteins compromise this function. Inactivation of UBQLN2 expression in HeLa cells reduced autophagic flux and autophagosome acidification. The defect in acidification was rescued by reexpression of wild type (WT) UBQLN2 but not by any of the five different UBQLN2 ALS/FTD mutants tested. Proteomic analysis and immunoblot studies revealed P497S mutant mice and UBQLN2 knockout HeLa and NSC34 cells have reduced expression of ATP6v1g1, a critical subunit of the vacuolar ATPase (V-ATPase) pump. Knockout of UBQLN2 expression in HeLa cells decreased turnover of ATP6v1g1, while overexpression of WT UBQLN2 increased biogenesis of ATP6v1g1 compared with P497S mutant UBQLN2 protein. In vitro interaction studies showed that ATP6v1g1 binds more strongly to WT UBQLN2 than to ALS/FTD mutant UBQLN2 proteins. Intriguingly, overexpression of ATP6v1g1 in UBQLN2 knockout HeLa cells increased autophagosome acidification, suggesting a therapeutic approach to overcome the acidification defect. Taken together, our findings suggest that UBQLN2 mutations drive pathogenesis through a dominant-negative loss-of-function mechanism in autophagy and that UBQLN2 functions as an important regulator of the expression and stability of ATP6v1g1. These findings may have important implications for devising therapies to treat UBQLN2-linked ALS/FTD.
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Affiliation(s)
- Josephine J Wu
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Ashley Cai
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Jessie E Greenslade
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Nicole R Higgins
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Cong Fan
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Nhat T T Le
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Micaela Tatman
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | | | - Miguel A Prado
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Birger V Dieriks
- Department of Anatomy and Medical Imaging, University of Auckland, 1010 Auckland, New Zealand
- Centre for Brain Research, University of Auckland, 1010 Auckland, New Zealand
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging, University of Auckland, 1010 Auckland, New Zealand
- Centre for Brain Research, University of Auckland, 1010 Auckland, New Zealand
| | - Christopher E Shaw
- United Kingdom Dementia Research Institute, King's College London, WC2R 2LS London, United Kingdom
- Maurice Wohl Clinical Neuroscience Institute, King's College London, SE5 9RT London, United Kingdom
- Institute of Psychiatry, Psychology, and Neuroscience, King's College London, WC2R 2LS London, United Kingdom
| | - Teepu Siddique
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging, University of Auckland, 1010 Auckland, New Zealand
- Centre for Brain Research, University of Auckland, 1010 Auckland, New Zealand
| | - Emma L Scotter
- Centre for Brain Research, University of Auckland, 1010 Auckland, New Zealand
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, 1010 Auckland, New Zealand
| | - Daniel Finley
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Mervyn J Monteiro
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201;
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32
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Srinivasan E, Rajasekaran R. A Systematic and Comprehensive Review on Disease-Causing Genes in Amyotrophic Lateral Sclerosis. J Mol Neurosci 2020; 70:1742-1770. [PMID: 32415434 DOI: 10.1007/s12031-020-01569-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder and is characterized by degeneration and axon loss from the upper motor neuron, that descends from the lower motor neuron in the brain. Over the period, assorted outcomes from medical findings, molecular pathogenesis, and structural and biophysical studies have abetted in providing thoughtful insights underlying the importance of disease-causing genes in ALS. Consequently, numerous mechanisms were proposed for the pathogenesis of ALS, considering protein mutations, aggregation, and misfolding. Besides, the answers to the majority of ALS cases that happen to be sporadic still remain obscure. The application in discovering susceptibility factors in ALS contemplating the genetic factors is to be further dissevered in the future years with innovation in research studies. Hence, this review targets in revisiting the breakthroughs on the disease-causing genes related with ALS.
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Affiliation(s)
- E Srinivasan
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (deemed to be university), Vellore, Tamil Nadu, 632014, India
| | - R Rajasekaran
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (deemed to be university), Vellore, Tamil Nadu, 632014, India.
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UBQLN2 Promotes the Production of Type I Interferon via the TBK1-IRF3 Pathway. Cells 2020; 9:cells9051205. [PMID: 32413959 PMCID: PMC7290724 DOI: 10.3390/cells9051205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations of Ubiquilin 2 (UBQLN2) or TANK-binding kinase 1 (TBK1) are associated with amyotrophic lateral sclerosis and frontotemporal degeneration (ALS/FTD). However, the mechanisms whereby UBQLN2 or TBK1 mutations lead to ALS and FTD remain unclear. Here, we explored the effect of UBQLN2 on TBK1 in HEK-293T cells or in CRISPR-Cas9-mediated IRF3 and IRF7 knockout (KO) cells. We found an interaction between TBK1 and UBQLN2, which was affected by ALS/FTD-linked mutations in TBK1 or UBQLN2. Co-expression of UBQLN2 with TBK1 elevated the protein level of TBK1 as well as the phosphorylation of TBK1 and IRF3 in a UBQLN2 dose-dependent manner, and this phosphorylation was reduced by mutant UBQLN2. In addition, the cellular production of IFN1 and related pro-inflammatory cytokines was substantially elevated when UBQLN2 and TBK1 were co-expressed, which was also decreased by mutant UBQLN2. Functional assay revealed that mutant UBQLN2 significantly reduced the binding affinity of TBK1 for its partners, including IRF3, (SQSTM1)/p62 and optineurin (OPTN). Moreover, complete loss of IRF3 abolished the induction of IFN1 and related pro-inflammatory cytokines enhanced by UBQLN2 in HEK-293T cells, whereas no significant change in IRF7 knockout cells was observed. Thus, our findings suggest that UBQLN2 promotes IRF3 phosphorylation via TBK1, leading to enhanced IFN1 induction, and also imply that the dysregulated TBK1-IRF3 pathway may play a role in UBQLN2-related neurodegeneration.
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Abstract
In this issue of Structure, Dao et al. (2019) report that ALS-linked mutations in the Pxx domain of Ubiquilin 2 (UBQLN2) differentially influence the protein's phase separation abilities. The affect is by reducing the temperature and UBQLN2 concentration necessary for liquid-liquid phase separation droplet formation and by modulating UBQLN2 oligomerization.
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Affiliation(s)
- Nicole Higgins
- The Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Brian Lin
- The Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mervyn J Monteiro
- The Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Romascano D, Barakovic M, Rafael-Patino J, Dyrby TB, Thiran JP, Daducci A. ActiveAx ADD : Toward non-parametric and orientationally invariant axon diameter distribution mapping using PGSE. Magn Reson Med 2019; 83:2322-2330. [PMID: 31691378 DOI: 10.1002/mrm.28053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/15/2019] [Accepted: 10/07/2019] [Indexed: 11/08/2022]
Abstract
PURPOSE Non-invasive axon diameter distribution (ADD) mapping using diffusion MRI is an ill-posed problem. Current ADD mapping methods require knowledge of axon orientation before performing the acquisition. Instead, ActiveAx uses a 3D sampling scheme to estimate the orientation from the signal, providing orientationally invariant estimates. The mean diameter is estimated instead of the distribution for the solution to be tractable. Here, we propose an extension (ActiveAxADD ) that provides non-parametric and orientationally invariant estimates of the whole distribution. THEORY The accelerated microstructure imaging with convex optimization (AMICO) framework accelerates mean diameter estimation using a linear formulation combined with Tikhonov regularization to stabilize the solution. Here, we implement a new formulation (ActiveAxADD ) that uses Laplacian regularization to provide robust estimates of the whole ADD. METHODS The performance of ActiveAxADD was evaluated using Monte Carlo simulations on synthetic white matter samples mimicking axon distributions reported in histological studies. RESULTS ActiveAxADD provided robust ADD reconstructions when considering the isolated intra-axonal signal. However, our formulation inherited some common microstructure imaging limitations. When accounting for the extra axonal compartment, estimated ADDs showed spurious peaks and increased variability because of the difficulty of disentangling intra and extra axonal contributions. CONCLUSION Laplacian regularization solves the ill-posedness regarding the intra axonal compartment. ActiveAxADD can potentially provide non-parametric and orientationally invariant ADDs from isolated intra-axonal signals. However, further work is required before ActiveAxADD can be applied to real data containing extra-axonal contributions, as disentangling the 2 compartment appears to be an overlooked challenge that affects microstructure imaging methods in general.
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Affiliation(s)
- David Romascano
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland.,Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Muhamed Barakovic
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland
| | - Jonathan Rafael-Patino
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland
| | - Tim Bjørn Dyrby
- Danish Research Centre for Magnetic Resonance, Center for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Jean-Philippe Thiran
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland.,Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Vaud, Switzerland
| | - Alessandro Daducci
- Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland.,Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Vaud, Switzerland.,Computer Science Department, University of Verona, Verona, Italy
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Hegde RS, Zavodszky E. Recognition and Degradation of Mislocalized Proteins in Health and Disease. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033902. [PMID: 30833453 DOI: 10.1101/cshperspect.a033902] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A defining feature of eukaryotic cells is the segregation of complex biochemical processes among different intracellular compartments. The protein targeting, translocation, and trafficking pathways that sustain compartmentalization must recognize a diverse range of clients via degenerate signals. This recognition is imperfect, resulting in polypeptides at incorrect cellular locations. Cells have evolved mechanisms to selectively recognize mislocalized proteins and triage them for degradation or rescue. These spatial quality control pathways maintain cellular protein homeostasis, become especially important during organelle stress, and might contribute to disease when they are impaired or overwhelmed.
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Affiliation(s)
- Ramanujan S Hegde
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Eszter Zavodszky
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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Renaud L, Picher-Martel V, Codron P, Julien JP. Key role of UBQLN2 in pathogenesis of amyotrophic lateral sclerosis and frontotemporal dementia. Acta Neuropathol Commun 2019; 7:103. [PMID: 31319884 PMCID: PMC6889556 DOI: 10.1186/s40478-019-0758-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 06/22/2019] [Indexed: 12/11/2022] Open
Abstract
Ubiquilin-2 (UBQLN2) is a member of the ubiquilin family, actively implicated in the degradation of misfolded and redundant proteins through the ubiquitin-proteasome system and macroautophagy. UBQLN2 received much attention after the discovery of gene mutations in amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). The abnormal presence of positive UBQLN2 inclusion in the cytosol of degenerating motor neurons of familial and sporadic forms of ALS patients has been newly related to neurodegeneration. Only recently, data have emerged on its role in liquid-liquid phase separation, in stress granule development and in the formation of secondary amyloid structures. Furthermore, several animal models are available to investigate its involvement in TDP-43 pathology and neuroinflammation in ALS. This review addresses the molecular pathogenetic pathways involving UBQLN2 abnormalities which are converging toward defects in clearance mechanisms. UBQLN2.
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Ragagnin AMG, Shadfar S, Vidal M, Jamali MS, Atkin JD. Motor Neuron Susceptibility in ALS/FTD. Front Neurosci 2019; 13:532. [PMID: 31316328 PMCID: PMC6610326 DOI: 10.3389/fnins.2019.00532] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/08/2019] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the death of both upper and lower motor neurons (MNs) in the brain, brainstem and spinal cord. The neurodegenerative mechanisms leading to MN loss in ALS are not fully understood. Importantly, the reasons why MNs are specifically targeted in this disorder are unclear, when the proteins associated genetically or pathologically with ALS are expressed ubiquitously. Furthermore, MNs themselves are not affected equally; specific MNs subpopulations are more susceptible than others in both animal models and human patients. Corticospinal MNs and lower somatic MNs, which innervate voluntary muscles, degenerate more readily than specific subgroups of lower MNs, which remain resistant to degeneration, reflecting the clinical manifestations of ALS. In this review, we discuss the possible factors intrinsic to MNs that render them uniquely susceptible to neurodegeneration in ALS. We also speculate why some MN subpopulations are more vulnerable than others, focusing on both their molecular and physiological properties. Finally, we review the anatomical network and neuronal microenvironment as determinants of MN subtype vulnerability and hence the progression of ALS.
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Affiliation(s)
- Audrey M G Ragagnin
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sina Shadfar
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Marta Vidal
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Md Shafi Jamali
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Julie D Atkin
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
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39
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Harman CA, Monteiro MJ. The specificity of ubiquitin binding to ubiquilin-1 is regulated by sequences besides its UBA domain. Biochim Biophys Acta Gen Subj 2019; 1863:1568-1574. [PMID: 31175912 DOI: 10.1016/j.bbagen.2019.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/24/2019] [Accepted: 06/03/2019] [Indexed: 12/12/2022]
Abstract
UBQLN proteins regulate proteostasis by facilitating clearance of misfolded proteins through the proteasome and autophagy degradation pathways. Consistent with its proteasomal function, UBQLN proteins contain both UBL and UBA domains, which bind subunits of the proteasome, including the S5a subunit, and ubiquitin chains, respectively. Conclusions regarding the binding properties of UBQLN proteins have been derived principally through studies of its individual domains, not the full-length (FL) proteins. Here we describe the in vitro binding properties of FL-UBQLN1 with the S5a subunit of the proteasome and two different lysine-linked (K48 or K63) ubiquitin chains. We show that in contrast to its isolated UBA domain, which binds almost equally well with both K48 and K63 ubiquitin chains, FL UBQLN1 binds preferentially with K63 chains. Furthermore, we show that deletion of the UBL domain from UBQLN1 abrogates ubiquitin binding. Taken together these results suggest that sequences outside of the UBA domain in UBQLN1 function to regulate the specificity and binding with different ubiquitin moieties. We also show that the UBL domain of UBQLN1 is required for S5a binding and that its binding to UBQLN1, in turn, enhances K48 ubiquitin chain binding to the complex. We discuss the implications of our findings with the known function of UBQLN proteins in protein degradation.
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Affiliation(s)
- Christine A Harman
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States.
| | - Mervyn J Monteiro
- Center for Biomedical Engineering and Technology, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States.
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40
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Meng T, Lin S, Zhuang H, Huang H, He Z, Hu Y, Gong Q, Feng D. Recent progress in the role of autophagy in neurological diseases. Cell Stress 2019; 3:141-161. [PMID: 31225510 PMCID: PMC6551859 DOI: 10.15698/cst2019.05.186] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Autophagy (here refers to macroautophagy) is a catabolic pathway by which large protein aggregates and damaged organelles are first sequestered into a double-membraned structure called autophago-some and then delivered to lysosome for destruction. Recently, tremen-dous progress has been made to elucidate the molecular mechanism and functions of this essential cellular metabolic process. In addition to being either a rubbish clearing system or a cellular surviving program in response to different stresses, autophagy plays important roles in a large number of pathophysiological conditions, such as cancer, diabetes, and especially neurodegenerative disorders. Here we review recent progress in the role of autophagy in neurological diseases and discuss how dysregulation of autophagy initiation, autophagosome formation, maturation, and/or au-tophagosome-lysosomal fusion step contributes to the pathogenesis of these disorders in the nervous system.
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Affiliation(s)
- Tian Meng
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
| | - Shiyin Lin
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
| | - Haixia Zhuang
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
| | - Haofeng Huang
- Institute of Neurology, Guangdong Key Laboratory of Age-Related Cardiac-Cerebral Vascular Disease, Affiliated Hospital of Guangdong Medical College, Zhanjiang, Guangdong, China
| | - Zhengjie He
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
| | - Yongquan Hu
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
| | - Qing Gong
- Department of Biochemistry and Molecular Biology, GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou 511436, People's Republic of China
| | - Du Feng
- State Key Laboratory of Respiratory Disease, School of Basic Medical Sciences, Guangzhou Medical University; Affiliated Cancer Hospital of Guangzhou Medical University, Guangzhou 511436, China
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Non-Proteasomal UbL-UbA Family of Proteins in Neurodegeneration. Int J Mol Sci 2019; 20:ijms20081893. [PMID: 30999567 PMCID: PMC6514573 DOI: 10.3390/ijms20081893] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/09/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin-like/ubiquitin-associated proteins (UbL-UbA) are a well-studied family of non-proteasomal ubiquitin receptors that are evolutionarily conserved across species. Members of this non-homogenous family facilitate and support proteasomal activity by promoting different effects on proteostasis but exhibit diverse extra-proteasomal activities. Dysfunctional UbL-UbA proteins render cells, particularly neurons, more susceptible to stressors or aging and may cause earlier neurodegeneration. In this review, we summarized the properties and functions of UbL-UbA family members identified to date, with an emphasis on new findings obtained using Drosophila models showing a direct or indirect role in some neurodegenerative diseases.
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42
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ALS-Linked Mutations Affect UBQLN2 Oligomerization and Phase Separation in a Position- and Amino Acid-Dependent Manner. Structure 2019; 27:937-951.e5. [PMID: 30982635 DOI: 10.1016/j.str.2019.03.012] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/22/2018] [Accepted: 03/15/2019] [Indexed: 12/14/2022]
Abstract
Proteasomal shuttle factor UBQLN2 is recruited to stress granules and undergoes liquid-liquid phase separation (LLPS) into protein-containing droplets. Mutations to UBQLN2 have recently been shown to cause dominant X-linked inheritance of amyotrophic lateral sclerosis (ALS) and ALS/dementia. Interestingly, most of these UBQLN2 mutations reside in its proline-rich (Pxx) region, an important modulator of LLPS. Here, we demonstrated that ALS-linked Pxx mutations differentially affect UBQLN2 LLPS, depending on both amino acid substitution and sequence position. Using size-exclusion chromatography, analytical ultracentrifugation, microscopy, and NMR spectroscopy, we determined that those Pxx mutants that enhanced UBQLN2 oligomerization decreased saturation concentrations needed for LLPS and promoted solid-like and viscoelastic morphological changes to UBQLN2 liquid assemblies. Ubiquitin disassembled all LLPS-induced mutant UBQLN2 aggregates. We postulate that the changes in physical properties caused by ALS-linked Pxx mutations modify UBQLN2 behavior in vivo, possibly contributing to aberrant stress granule morphology and dynamics, leading to formation of inclusions, pathological characteristics of ALS.
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43
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Kim SH, Stiles SG, Feichtmeier JM, Ramesh N, Zhan L, Scalf MA, Smith LM, Pandey UB, Tibbetts RS. Mutation-dependent aggregation and toxicity in a Drosophila model for UBQLN2-associated ALS. Hum Mol Genet 2019; 27:322-337. [PMID: 29161404 DOI: 10.1093/hmg/ddx403] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/14/2017] [Indexed: 12/12/2022] Open
Abstract
Members of the conserved ubiquilin (UBQLN) family of ubiquitin (Ub) chaperones harbor an antipodal UBL (Ub-like)-UBA (Ub-associated) domain arrangement and participate in proteasome and autophagosome-mediated protein degradation. Mutations in a proline-rich-repeat region (PRR) of UBQLN2 cause amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD); however, neither the normal functions of the PRR nor impacts of ALS-associated mutations within it are well understood. In this study, we show that ALS mutations perturb UBQLN2 solubility and folding in a mutation-specific manner. Biochemical impacts of ALS mutations were additive, transferable to UBQLN1, and resulted in enhanced Ub association. A Drosophila melanogaster model for UBQLN2-associated ALS revealed that both wild-type and ALS-mutant UBQLN2 alleles disrupted Ub homeostasis; however, UBQLN2ALS mutants exhibited age-dependent aggregation and caused toxicity phenotypes beyond those seen for wild-type UBQLN2. Although UBQLN2 toxicity was not correlated with aggregation in the compound eye, aggregation-prone UBQLN2 mutants elicited climbing defects and neuromuscular junctions (NMJ) abnormalities when expressed in neurons. An UBA domain mutation that abolished Ub binding also diminished UBQLN2 toxicity, implicating Ub binding in the underlying pathomechanism. We propose that ALS-associated mutations in UBQLN2 disrupt folding and that both aggregated species and soluble oligomers instigate neuron autonomous toxicity through interference with Ub homeostasis.
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Affiliation(s)
- Sang Hwa Kim
- Department of Human Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Shannon G Stiles
- Department of Human Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Joseph M Feichtmeier
- Department of Human Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Nandini Ramesh
- Department of Pediatrics, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Lihong Zhan
- Department of Human Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Mark A Scalf
- Department of Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
| | - Udai Bhan Pandey
- Department of Pediatrics, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Randal S Tibbetts
- Department of Human Oncology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53705, USA
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De Giorgio F, Maduro C, Fisher EMC, Acevedo-Arozena A. Transgenic and physiological mouse models give insights into different aspects of amyotrophic lateral sclerosis. Dis Model Mech 2019; 12:12/1/dmm037424. [PMID: 30626575 PMCID: PMC6361152 DOI: 10.1242/dmm.037424] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A wide range of genetic mouse models is available to help researchers dissect human disease mechanisms. Each type of model has its own distinctive characteristics arising from the nature of the introduced mutation, as well as from the specific changes to the gene of interest. Here, we review the current range of mouse models with mutations in genes causative for the human neurodegenerative disease amyotrophic lateral sclerosis. We focus on the two main types of available mutants: transgenic mice and those that express mutant genes at physiological levels from gene targeting or from chemical mutagenesis. We compare the phenotypes for genes in which the two classes of model exist, to illustrate what they can teach us about different aspects of the disease, noting that informative models may not necessarily mimic the full trajectory of the human condition. Transgenic models can greatly overexpress mutant or wild-type proteins, giving us insight into protein deposition mechanisms, whereas models expressing mutant genes at physiological levels may develop slowly progressing phenotypes but illustrate early-stage disease processes. Although no mouse models fully recapitulate the human condition, almost all help researchers to understand normal and abnormal biological processes, providing that the individual characteristics of each model type, and how these may affect the interpretation of the data generated from each model, are considered and appreciated.
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Affiliation(s)
- Francesca De Giorgio
- Department of Neuromuscular Diseases, UCL Institute of Neurology, and MRC Centre for Neuromuscular Disease, University College London, Queen Square, London WC1N 3BG, UK
| | - Cheryl Maduro
- Department of Neuromuscular Diseases, UCL Institute of Neurology, and MRC Centre for Neuromuscular Disease, University College London, Queen Square, London WC1N 3BG, UK
| | - Elizabeth M C Fisher
- Department of Neuromuscular Diseases, UCL Institute of Neurology, and MRC Centre for Neuromuscular Disease, University College London, Queen Square, London WC1N 3BG, UK
| | - Abraham Acevedo-Arozena
- Unidad de Investigación Hospital Universitario de Canarias, Fundación Canaria de Investigación Sanitaria and Instituto de Tecnologías Biomédicas (ITB), La Laguna, 38320 Tenerife, Spain
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45
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RNA Granules and Their Role in Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:195-245. [DOI: 10.1007/978-3-030-31434-7_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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46
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Georgiou P, Zanos P, Jenne CE, Gould TD. Sex-Specific Involvement of Estrogen Receptors in Behavioral Responses to Stress and Psychomotor Activation. Front Psychiatry 2019; 10:81. [PMID: 30863326 PMCID: PMC6399411 DOI: 10.3389/fpsyt.2019.00081] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 02/06/2019] [Indexed: 12/25/2022] Open
Abstract
Fluctuating hormone levels, such as estradiol might underlie the difference in the prevalence of psychiatric disorders observed in women vs. men. Estradiol exert its effects primarily through binding on the two classical estrogen receptor subtypes, alpha (ERα) and beta (ERβ). Both receptors have been suggested to a have role in the development of psychiatric disorders, however, most of the current literature is limited to their role in females. We investigated the role of estrogen receptors on cognition (novel-object recognition), anxiety (open-field test, elevated-plus maze, and light/dark box), stress-responsive behaviors (forced-swim test, learned helplessness following inescapable shock, and sucrose preference), pre-pulse inhibition (PPI) and amphetamine-induced hyperlocomotion in both male and female mice either lacking the ERα or ERβ receptor. We found that female Esr1 -/- mice have attenuated pre-pulse inhibition, whereas female Esr2 -/- mice manifested enhanced pre-pulse inhibition. No pre-pulse inhibition difference was observed in male Esr1 -/- and Esr2 -/- mice. Moreover, amphetamine-induced hyperlocomotion was decreased in male Esr1 -/-, but not Esr2 -/- mice, while female Esr1 -/- and Esr2 -/- mice showed an enhanced response. Genetic absence of ERα did not alter the escape capability or sucrose preference following inescapable shock in both male and female mice. In contrast, female, but not male Esr2 -/- mice, manifested decreased escape failures compared with controls. Lack of Esr2 gene in male mice was associated with decreased sucrose preference following inescapable shock, suggesting susceptibility for development of anhedonia following stress. No sucrose preference differences were found in female Esr2 -/- mice following inescapable shock stress. Lastly, we demonstrated that lack of Esr1 or Esr2 genes had no effect on memory and anxiety-like behaviors in both male and female mice. Our findings indicate a differential sex-specific involvement of estrogen receptors in the development of stress-mediated maladaptive behaviors as well as psychomotor activation responses suggesting that these receptors might act as potential treatment targets in a sex-specific manner.
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Affiliation(s)
- Polymnia Georgiou
- Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Panos Zanos
- Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Carleigh E Jenne
- Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Todd D Gould
- Department of Psychiatry, School of Medicine, University of Maryland, Baltimore, MD, United States.,Department of Pharmacology, School of Medicine, University of Maryland, Baltimore, MD, United States.,Department of Anatomy & Neurobiology, School of Medicine, University of Maryland, Baltimore, MD, United States.,Veterans Affairs Maryland Health Care System, Baltimore, MD, United States
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47
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Ubiquilin 2 modulates ALS/FTD-linked FUS-RNA complex dynamics and stress granule formation. Proc Natl Acad Sci U S A 2018; 115:E11485-E11494. [PMID: 30442662 DOI: 10.1073/pnas.1811997115] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The ubiquitin-like protein ubiquilin 2 (UBQLN2) has been genetically and pathologically linked to the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but its normal cellular functions are not well understood. In a search for UBQLN2-interacting proteins, we found an enrichment of stress granule (SG) components, including ALS/FTD-linked heterogeneous ribonucleoprotein fused in sarcoma (FUS). Through the use of an optimized SG detection method, we observed UBQLN2 and its interactors at SGs. A low complexity, Sti1-like repeat region in UBQLN2 was sufficient for its localization to SGs. Functionally, UBQLN2 negatively regulated SG formation. UBQLN2 increased the dynamics of FUS-RNA interaction and promoted the fluidity of FUS-RNA complexes at a single-molecule level. This solubilizing effect corresponded to a dispersal of FUS liquid droplets in vitro and a suppression of FUS SG formation in cells. ALS-linked mutations in UBQLN2 reduced its association with FUS and impaired its function in regulating FUS-RNA complex dynamics and SG formation. These results reveal a previously unrecognized role for UBQLN2 in regulating the early stages of liquid-liquid phase separation by directly modulating the fluidity of protein-RNA complexes and the dynamics of SG formation.
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48
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Chen T, Huang B, Shi X, Gao L, Huang C. Mutant UBQLN2 P497H in motor neurons leads to ALS-like phenotypes and defective autophagy in rats. Acta Neuropathol Commun 2018; 6:122. [PMID: 30409191 PMCID: PMC6225656 DOI: 10.1186/s40478-018-0627-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in ubiquilin2 (UBQLN2) have been linked to abnormal protein aggregation in amyotrophic lateral sclerosis (ALS). The mechanisms underlying UBQLN2-related neurodegenerative diseases remain unclear. Using a tetracycline-regulated gene expression system, the ALS-linked UBQLN2P497H mutant was selectively expressed in either the spinal motor neurons or astrocytes in rats. We found that selectively expressing mutant UBQLN2P497H in the spinal motor neurons caused several core features of ALS, including the progressive degeneration of motor neurons, the denervation atrophy of skeletal muscles, and the abnormal protein accumulation. Furthermore, mutant UBQLN2P497H accumulation was associated with an age-dependent decrease in several core autophagy-related proteins. ALS-like phenotypes were not observed when mutant UBQLN2P497H was overexpressed in the astrocytes, however, even though the expression of the mutant UBQLN2P497H protein was higher in these rats. Our results suggest that selectively expressing mutant UBQLN2P497H in motor neurons is sufficient to trigger the development of ALS in rats. Our results further indicate that the compromised autophagy-lysosomal pathway plays a critical role in the pathogenesis of UBQLN2-related neurodegenerative diseases.
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Picher-Martel V, Renaud L, Bareil C, Julien JP. Neuronal Expression of UBQLN2 P497H Exacerbates TDP-43 Pathology in TDP-43 G348C Mice through Interaction with Ubiquitin. Mol Neurobiol 2018; 56:4680-4696. [PMID: 30377984 PMCID: PMC6647471 DOI: 10.1007/s12035-018-1411-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 10/24/2018] [Indexed: 12/11/2022]
Abstract
Mutations in the gene encoding ubiquilin-2 (UBQLN2) are linked to amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). UBQLN2 plays a central role in ubiquitin proteasome system (UPS) and UBQLN2 up-regulation exacerbates TDP-43 cytoplasmic aggregates. To analyze interaction between UBQLN2 and TDP-43 and to produce a relevant ALS animal model, we have generated a new transgenic mouse expressing UBQLN2P497H under the neurofilament heavy (NFH) gene promoter. The UBQLN2P497H mice were then bred with our previously described TDP-43G348C mice to generate double-transgenic UBQLN2P497H; TDP-43G348C mice. With low-expression levels of UBQLN2, the double-transgenic mice developed TDP-43 cytosolic accumulations in motor neurons starting at 5 months of age. These double-transgenic mice exhibited motor neuron loss, muscle atrophy, as well as motor and cognitive deficits during aging. The microglia from double-transgenic mice were hyperresponsive to intraperitoneal injection of lipopolysaccharide (LPS). In vivo and in vitro analyses suggested that extra UBQLN2 proteins can exacerbate cytoplasmic TDP-43 accumulations by competing with the UPS for binding to ubiquitin. Thus, increasing the pool of ubiquitin promoted the UPS function with ensuing reduction of TDP-43 cytosolic accumulations. In conclusion, the double-transgenic UBQLN2P497H; TDP-43G348C mice provides a unique mouse model of ALS/FTD with enhanced TDP-43 pathology that can be exploited for drug testing.
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Affiliation(s)
- Vincent Picher-Martel
- Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada.,CERVO Brain Research Centre, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada
| | - Laurence Renaud
- Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada.,CERVO Brain Research Centre, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada
| | - Christine Bareil
- CERVO Brain Research Centre, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada
| | - Jean-Pierre Julien
- Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada. .,CERVO Brain Research Centre, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada.
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50
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Sharkey LM, Safren N, Pithadia AS, Gerson JE, Dulchavsky M, Fischer S, Patel R, Lantis G, Ashraf N, Kim JH, Meliki A, Minakawa EN, Barmada SJ, Ivanova MI, Paulson HL. Mutant UBQLN2 promotes toxicity by modulating intrinsic self-assembly. Proc Natl Acad Sci U S A 2018; 115:E10495-E10504. [PMID: 30333186 PMCID: PMC6217421 DOI: 10.1073/pnas.1810522115] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
UBQLN2 is one of a family of proteins implicated in ubiquitin-dependent protein quality control and integrally tied to human neurodegenerative disease. Whereas wild-type UBQLN2 accumulates in intraneuronal deposits in several common age-related neurodegenerative diseases, mutations in the gene encoding this protein result in X-linked amyotrophic lateral sclerosis/frontotemporal dementia associated with TDP43 accumulation. Using in vitro protein analysis, longitudinal fluorescence imaging and cellular, neuronal, and transgenic mouse models, we establish that UBQLN2 is intrinsically prone to self-assemble into higher-order complexes, including liquid-like droplets and amyloid aggregates. UBQLN2 self-assembly and solubility are reciprocally modulated by the protein's ubiquitin-like and ubiquitin-associated domains. Moreover, a pathogenic UBQLN2 missense mutation impairs droplet dynamics and favors amyloid-like aggregation associated with neurotoxicity. These data emphasize the critical link between UBQLN2's role in ubiquitin-dependent pathways and its propensity to self-assemble and aggregate in neurodegenerative diseases.
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Affiliation(s)
- Lisa M Sharkey
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
- Protein Folding Disease Initiative, University of Michigan, Ann Arbor, MI 48109-2200
| | - Nathaniel Safren
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Amit S Pithadia
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Julia E Gerson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Mark Dulchavsky
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Svetlana Fischer
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Ronak Patel
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Gabrielle Lantis
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Naila Ashraf
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - John H Kim
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109-2200
| | - Alia Meliki
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200
| | - Eiko N Minakawa
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502, Japan
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200;
- Protein Folding Disease Initiative, University of Michigan, Ann Arbor, MI 48109-2200
| | - Magdalena I Ivanova
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200;
- Protein Folding Disease Initiative, University of Michigan, Ann Arbor, MI 48109-2200
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109-2200
| | - Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109-2200;
- Protein Folding Disease Initiative, University of Michigan, Ann Arbor, MI 48109-2200
- Michigan Alzheimer's Disease Center, University of Michigan, Ann Arbor, MI 48109-2200
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