1
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Smeele PH, Cesare G, Vaccari T. ALS' Perfect Storm: C9orf72-Associated Toxic Dipeptide Repeats as Potential Multipotent Disruptors of Protein Homeostasis. Cells 2024; 13:178. [PMID: 38247869 PMCID: PMC10813877 DOI: 10.3390/cells13020178] [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: 12/13/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
Protein homeostasis is essential for neuron longevity, requiring a balanced regulation between protein synthesis and degradation. The clearance of misfolded and aggregated proteins, mediated by autophagy and the ubiquitin-proteasome systems, maintains protein homeostasis in neurons, which are post-mitotic and thus cannot use cell division to diminish the burden of misfolded proteins. When protein clearance pathways are overwhelmed or otherwise disrupted, the accumulation of misfolded or aggregated proteins can lead to the activation of ER stress and the formation of stress granules, which predominantly attempt to restore the homeostasis by suppressing global protein translation. Alterations in these processes have been widely reported among studies investigating the toxic function of dipeptide repeats (DPRs) produced by G4C2 expansion in the C9orf72 gene of patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In this review, we outline the modalities of DPR-induced disruptions in protein homeostasis observed in a wide range of models of C9orf72-linked ALS/FTD. We also discuss the relative importance of each DPR for toxicity, possible synergies between DPRs, and discuss the possible functional relevance of DPR aggregation to disease pathogenesis. Finally, we highlight the interdependencies of the observed effects and reflect on the importance of feedback and feedforward mechanisms in their contribution to disease progression. A better understanding of DPR-associated disease pathogenesis discussed in this review might shed light on disease vulnerabilities that may be amenable with therapeutic interventions.
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Affiliation(s)
| | | | - Thomas Vaccari
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy
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2
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Motaln H, Čerček U, Yamoah A, Tripathi P, Aronica E, Goswami A, Rogelj B. Abl kinase-mediated FUS Tyr526 phosphorylation alters nucleocytoplasmic FUS localization in FTLD-FUS. Brain 2023; 146:4088-4104. [PMID: 37071594 PMCID: PMC10545532 DOI: 10.1093/brain/awad130] [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: 10/07/2022] [Revised: 03/02/2023] [Accepted: 03/28/2023] [Indexed: 04/19/2023] Open
Abstract
Nuclear to cytoplasmic mislocalization and aggregation of multiple RNA-binding proteins (RBPs), including FUS, are the main neuropathological features of the majority of cases of amyotrophic lateral sclerosis (ALS) and frontotemporal lobular degeneration (FTLD). In ALS-FUS, these aggregates arise from disease-associated mutations in FUS, whereas in FTLD-FUS, the cytoplasmic inclusions do not contain mutant FUS, suggesting different molecular mechanisms of FUS pathogenesis in FTLD that remain to be investigated. We have previously shown that phosphorylation of the C-terminal Tyr526 of FUS results in increased cytoplasmic retention of FUS due to impaired binding to the nuclear import receptor TNPO1. Inspired by the above notions, in the current study we developed a novel antibody against the C-terminally phosphorylated Tyr526 FUS (FUSp-Y526) that is specifically capable of recognizing phosphorylated cytoplasmic FUS, which is poorly recognized by other commercially available FUS antibodies. Using this FUSp-Y526 antibody, we demonstrated a FUS phosphorylation-specific effect on the cytoplasmic distribution of soluble and insoluble FUSp-Y526 in various cells and confirmed the involvement of the Src kinase family in Tyr526 FUS phosphorylation. In addition, we found that FUSp-Y526 expression pattern correlates with active pSrc/pAbl kinases in specific brain regions of mice, indicating preferential involvement of cAbl in the cytoplasmic mislocalization of FUSp-Y526 in cortical neurons. Finally, the pattern of immunoreactivity of active cAbl kinase and FUSp-Y526 revealed altered cytoplasmic distribution of FUSp-Y526 in cortical neurons of post-mortem frontal cortex tissue from FTLD patients compared with controls. The overlap of FUSp-Y526 and FUS signals was found preferentially in small diffuse inclusions and was absent in mature aggregates, suggesting possible involvement of FUSp-Y526 in the formation of early toxic FUS aggregates in the cytoplasm that are largely undetected by commercially available FUS antibodies. Given the overlapping patterns of cAbl activity and FUSp-Y526 distribution in cortical neurons, and cAbl induced sequestration of FUSp-Y526 into G3BP1 positive granules in stressed cells, we propose that cAbl kinase is actively involved in mediating cytoplasmic mislocalization and promoting toxic aggregation of wild-type FUS in the brains of FTLD patients, as a novel putative underlying mechanism of FTLD-FUS pathophysiology and progression.
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Affiliation(s)
- Helena Motaln
- Department of Biotechnology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Urša Čerček
- Department of Biotechnology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Graduate School of Biomedicine, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Alfred Yamoah
- Institute of Neuropathology, RWTH Aachen University Medical School, 52074 Aachen, Germany
| | - Priyanka Tripathi
- Institute of Neuropathology, RWTH Aachen University Medical School, 52074 Aachen, Germany
| | - Eleonora Aronica
- Amsterdam UMC location University of Amsterdam, Department of Neuropathology, Amsterdam Neuroscience, 1105 Amsterdam, The Netherlands
| | - Anand Goswami
- Institute of Neuropathology, RWTH Aachen University Medical School, 52074 Aachen, Germany
- Department of Neurology, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Department of Neurology, Eleanor and Lou Gherig ALS Center, Columbia University, New York, NY 10032, USA
| | - Boris Rogelj
- Department of Biotechnology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
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3
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Malnar Črnigoj M, Čerček U, Yin X, Ho MT, Repic Lampret B, Neumann M, Hermann A, Rouleau G, Suter B, Mayr M, Rogelj B. Phenylalanine-tRNA aminoacylation is compromised by ALS/FTD-associated C9orf72 C4G2 repeat RNA. Nat Commun 2023; 14:5764. [PMID: 37717009 PMCID: PMC10505166 DOI: 10.1038/s41467-023-41511-3] [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: 10/14/2022] [Accepted: 09/07/2023] [Indexed: 09/18/2023] Open
Abstract
The expanded hexanucleotide GGGGCC repeat mutation in the C9orf72 gene is the main genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Under one disease mechanism, sense and antisense transcripts of the repeat are predicted to bind various RNA-binding proteins, compromise their function and cause cytotoxicity. Here we identify phenylalanine-tRNA synthetase (FARS) subunit alpha (FARSA) as the main interactor of the CCCCGG antisense repeat RNA in cytosol. The aminoacylation of tRNAPhe by FARS is inhibited by antisense RNA, leading to decreased levels of charged tRNAPhe. Remarkably, this is associated with global reduction of phenylalanine incorporation in the proteome and decrease in expression of phenylalanine-rich proteins in cellular models and patient tissues. In conclusion, this study reveals functional inhibition of FARSA in the presence of antisense RNA repeats. Compromised aminoacylation of tRNA could lead to impairments in protein synthesis and further contribute to C9orf72 mutation-associated pathology.
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Affiliation(s)
- Mirjana Malnar Črnigoj
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, 1000, Slovenia
- Graduate School of Biomedicine, Faculty of Medicine, University of Ljubljana, Ljubljana, 1000, Slovenia
| | - Urša Čerček
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, 1000, Slovenia
- Graduate School of Biomedicine, Faculty of Medicine, University of Ljubljana, Ljubljana, 1000, Slovenia
| | - Xiaoke Yin
- King's BHF Centre, King's College London, London, SE5 9NU, UK
| | - Manh Tin Ho
- Institute of Cell Biology, University of Bern, Bern, 3012, Switzerland
| | - Barbka Repic Lampret
- Clinical Institute of Special Laboratory Diagnostics, University Children's Hospital, University Medical Centre Ljubljana, Ljubljana, 1000, Slovenia
| | - Manuela Neumann
- Molecular Neuropathology of Neurodegenerative Diseases, German Center for Neurodegenerative Diseases, Tübingen, 72076, Germany
- Department of Neuropathology, University Hospital of Tübingen, Tübingen, 72076, Germany
| | - Andreas Hermann
- Translational Neurodegeneration Section "Albrecht-Kossel", Department of Neurology and Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, 18147, Rostock, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Rostock/Greifswald, 18147, Rostock, Germany
| | - Guy Rouleau
- Department of Human Genetics, McGill University, Montréal, QC, H3A 0G4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montréal, QC, H3A 0G4, Canada
| | - Beat Suter
- Institute of Cell Biology, University of Bern, Bern, 3012, Switzerland
| | - Manuel Mayr
- King's BHF Centre, King's College London, London, SE5 9NU, UK
| | - Boris Rogelj
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, 1000, Slovenia.
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, 1000, Slovenia.
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4
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Morón-Oset J, Fischer LKS, Jauré N, Zhang P, Jahn AJ, Supèr T, Pahl A, Isaacs AM, Grönke S, Partridge L. Repeat length of C9orf72-associated glycine-alanine polypeptides affects their toxicity. Acta Neuropathol Commun 2023; 11:140. [PMID: 37644512 PMCID: PMC10463776 DOI: 10.1186/s40478-023-01634-6] [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: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/31/2023] Open
Abstract
G4C2 hexanucleotide repeat expansions in a non-coding region of the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). G4C2 insertion length is variable, and patients can carry up to several thousand repeats. Dipeptide repeat proteins (DPRs) translated from G4C2 transcripts are thought to be a main driver of toxicity. Experiments in model organisms with relatively short DPRs have shown that arginine-rich DPRs are most toxic, while polyGlycine-Alanine (GA) DPRs cause only mild toxicity. However, GA is the most abundant DPR in patient brains, and experimental work in animals has generally relied on the use of low numbers of repeats, with DPRs often tagged for in vivo tracking. Whether repeat length or tagging affect the toxicity of GA has not been systematically assessed. Therefore, we generated Drosophila fly lines expressing GA100, GA200 or GA400 specifically in adult neurons. Consistent with previous studies, expression of GA100 and GA200 caused only mild toxicity. In contrast, neuronal expression of GA400 drastically reduced climbing ability and survival of flies, indicating that long GA DPRs can be highly toxic in vivo. This toxicity could be abolished by tagging GA400. Proteomics analysis of fly brains showed a repeat-length-dependent modulation of the brain proteome, with GA400 causing earlier and stronger changes than shorter GA proteins. PolyGA expression up-regulated proteins involved in ER to Golgi trafficking, and down-regulated proteins involved in insulin signalling. Experimental down-regulation of Tango1, a highly conserved regulator of ER-to Golgi transport, partially rescued GA400 toxicity, suggesting that misregulation of this process contributes to polyGA toxicity. Experimentally increasing insulin signaling also rescued GA toxicity. In summary, our data show that long polyGA proteins can be highly toxic in vivo, and that they may therefore contribute to ALS/FTD pathogenesis in patients.
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Affiliation(s)
- Javier Morón-Oset
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | | | - Nathalie Jauré
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Pingze Zhang
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Annika Julia Jahn
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Tessa Supèr
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - André Pahl
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
| | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9B, 50931, Cologne, Germany.
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK.
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5
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Chu S, Xie X, Payan C, Stochaj U. Valosin containing protein (VCP): initiator, modifier, and potential drug target for neurodegenerative diseases. Mol Neurodegener 2023; 18:52. [PMID: 37545006 PMCID: PMC10405438 DOI: 10.1186/s13024-023-00639-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023] Open
Abstract
The AAA+ ATPase valosin containing protein (VCP) is essential for cell and organ homeostasis, especially in cells of the nervous system. As part of a large network, VCP collaborates with many cofactors to ensure proteostasis under normal, stress, and disease conditions. A large number of mutations have revealed the importance of VCP for human health. In particular, VCP facilitates the dismantling of protein aggregates and the removal of dysfunctional organelles. These are critical events to prevent malfunction of the brain and other parts of the nervous system. In line with this idea, VCP mutants are linked to the onset and progression of neurodegeneration and other diseases. The intricate molecular mechanisms that connect VCP mutations to distinct brain pathologies continue to be uncovered. Emerging evidence supports the model that VCP controls cellular functions on multiple levels and in a cell type specific fashion. Accordingly, VCP mutants derail cellular homeostasis through several mechanisms that can instigate disease. Our review focuses on the association between VCP malfunction and neurodegeneration. We discuss the latest insights in the field, emphasize open questions, and speculate on the potential of VCP as a drug target for some of the most devastating forms of neurodegeneration.
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Affiliation(s)
- Siwei Chu
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Xinyi Xie
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Carla Payan
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada.
- Quantitative Life Sciences Program, McGill University, Montreal, Canada.
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6
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Viera Ortiz AP, Cajka G, Olatunji OA, Mikytuck B, Shalem O, Lee EB. Impaired ribosome-associated quality control of C9orf72 arginine-rich dipeptide-repeat proteins. Brain 2023; 146:2897-2912. [PMID: 36516294 PMCID: PMC10316761 DOI: 10.1093/brain/awac479] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 11/05/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022] Open
Abstract
Protein quality control pathways have evolved to ensure the fidelity of protein synthesis and efficiently clear potentially toxic protein species. Defects in ribosome-associated quality control and its associated factors have been implicated in the accumulation of aberrant proteins and neurodegeneration. C9orf72 repeat-associated non-AUG translation has been suggested to involve inefficient translation elongation, lead to ribosomal pausing and activation of ribosome-associated quality control pathways. However, the role of the ribosome-associated quality control complex in the processing of proteins generated through this non-canonical translation is not well understood. Here we use reporter constructs containing the C9orf72-associated hexanucleotide repeat, ribosome-associated quality control complex deficient cell models and stain for ribosome-associated quality control markers in C9orf72-expansion carrier human tissue to understand its role in dipeptide-repeat protein pathology. Our studies show that canonical ribosome-associated quality control substrates products are efficiently cleared by the ribosome-associated quality control complex in mammalian cells. Furthermore, using stalling reporter constructs, we show that repeats associated with the C9orf72-expansion induce ribosomal stalling when arginine (R)-rich dipeptide-repeat proteins are synthesized in a length-dependent manner. However, despite triggering this pathway, these arginine-rich dipeptide-repeat proteins are not efficiently processed by the core components of the ribosome-associated quality control complex (listerin, nuclear-export mediator factor and valosin containing protein) partly due to lack of lysine residues, which precludes ubiquitination. Deficient processing by this complex may be implicated in C9orf72-expansion associated disease as dipeptide-repeat protein inclusions were observed to be predominantly devoid of ubiquitin and co-localize with nuclear-export mediator factor in mutation carriers' frontal cortex and cerebellum tissue. These findings suggest that impaired processing of these arginine-rich dipeptide-repeat proteins derived from repeat-associated non-AUG translation by the ribosome-associated quality control complex may contribute to protein homeostasis dysregulation observed in C9orf72-expansion amyotrophic lateral sclerosis and frontotemporal degeneration neuropathogenesis.
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Affiliation(s)
- Ashley P Viera Ortiz
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gregory Cajka
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Olamide A Olatunji
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bailey Mikytuck
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ophir Shalem
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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7
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Miyagi T, Ueda K, Sugimoto M, Yagi T, Ito D, Yamazaki R, Narumi S, Hayamizu Y, Uji-i H, Kuroda M, Kanekura K. Differential toxicity and localization of arginine-rich C9ORF72 dipeptide repeat proteins depend on de-clustering of positive charges. iScience 2023; 26:106957. [PMID: 37332605 PMCID: PMC10275993 DOI: 10.1016/j.isci.2023.106957] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/30/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023] Open
Abstract
Arginine-rich dipeptide repeat proteins (R-DPRs), poly(PR) and poly(GR), translated from the hexanucleotide repeat expansion in the amyotrophic lateral sclerosis (ALS)-causative C9ORF72 gene, contribute significantly to pathogenesis of ALS. Although both R-DPRs share many similarities, there are critical differences in their subcellular localization, phase separation, and toxicity mechanisms. We analyzed localization, protein-protein interactions, and phase separation of R-DPR variants and found that sufficient segregation of arginine charges is necessary for nucleolar distribution. Proline not only efficiently separated the charges, but also allowed for weak, but highly multivalent binding. In contrast, because of its high flexibility, glycine cannot fully separate the charges, and poly(GR) behaves similarly to the contiguous arginines, being trapped in the cytoplasm. We conclude that the amino acid that spaces the arginine charges determines the strength and multivalency of the binding, leading to differences in localization and toxicity mechanisms.
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Affiliation(s)
- Tamami Miyagi
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
- Department of Pharmacology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
| | - Koji Ueda
- Cancer Proteomics Group, Cancer Precision Medicine Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550, Japan
| | - Masahiro Sugimoto
- Research and Development Center for Minimally Invasive Therapies, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
- Institute for Advanced Biosciences, KEIO University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan
| | - Takuya Yagi
- Department of Neurology, KEIO University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Daisuke Ito
- Department of Physiology, KEIO University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Rio Yamazaki
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
- Department of Pharmacology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
| | - Satoshi Narumi
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
| | - Yuhei Hayamizu
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Hiroshi Uji-i
- Department of Nanomaterials and Nanoscopy, Research Institute for Electronic Science, Hokkaido University, Kita 10 Nishi 20, North Ward, Sapporo, Hokkaido 001-0020, Japan
- Department of Chemistry, KU Leuven Celestijnenlaan 200F, Heverlee, 3001 Leuven, Belgium
| | - Masahiko Kuroda
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
| | - Kohsuke Kanekura
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
- Department of Pharmacology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan
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8
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De Marchi F, Franjkic T, Schito P, Russo T, Nimac J, Chami AA, Mele A, Vidatic L, Kriz J, Julien JP, Apic G, Russell RB, Rogelj B, Cannon JR, Baralle M, Agosta F, Hecimovic S, Mazzini L, Buratti E, Munitic I. Emerging Trends in the Field of Inflammation and Proteinopathy in ALS/FTD Spectrum Disorder. Biomedicines 2023; 11:1599. [PMID: 37371694 PMCID: PMC10295684 DOI: 10.3390/biomedicines11061599] [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: 04/28/2023] [Revised: 05/27/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Proteinopathy and neuroinflammation are two main hallmarks of neurodegenerative diseases. They also represent rare common events in an exceptionally broad landscape of genetic, environmental, neuropathologic, and clinical heterogeneity present in patients. Here, we aim to recount the emerging trends in amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD) spectrum disorder. Our review will predominantly focus on neuroinflammation and systemic immune imbalance in ALS and FTD, which have recently been highlighted as novel therapeutic targets. A common mechanism of most ALS and ~50% of FTD patients is dysregulation of TAR DNA-binding protein 43 (TDP-43), an RNA/DNA-binding protein, which becomes depleted from the nucleus and forms cytoplasmic aggregates in neurons and glia. This, in turn, via both gain and loss of function events, alters a variety of TDP-43-mediated cellular events. Experimental attempts to target TDP-43 aggregates or manipulate crosstalk in the context of inflammation will be discussed. Targeting inflammation, and the immune system in general, is of particular interest because of the high plasticity of immune cells compared to neurons.
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Affiliation(s)
- Fabiola De Marchi
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore Della Carità Hospital, Corso Mazzini 18, 28100 Novara, Italy; (F.D.M.); (A.M.)
| | - Toni Franjkic
- Laboratory for Molecular Immunology, Department of Biotechnology, University of Rijeka, R. Matejcic 2, 51000 Rijeka, Croatia;
- Metisox, Cambridge CB24 9NL, UK;
| | - Paride Schito
- Department of Neurology & Neuropathology Unit, Institute of Experimental Neurology (INSPE), Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; (P.S.); (T.R.)
| | - Tommaso Russo
- Department of Neurology & Neuropathology Unit, Institute of Experimental Neurology (INSPE), Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; (P.S.); (T.R.)
| | - Jerneja Nimac
- Department of Biotechnology, Jozef Stefan Institute, SI-1000 Ljubljana, Slovenia; (J.N.); (B.R.)
- Graduate School of Biomedicine, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Anna A. Chami
- CERVO Research Centre, Laval University, Quebec City, QC G1J 2G3, Canada; (A.A.C.); (J.K.); (J.-P.J.)
| | - Angelica Mele
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore Della Carità Hospital, Corso Mazzini 18, 28100 Novara, Italy; (F.D.M.); (A.M.)
| | - Lea Vidatic
- Laboratory for Neurodegenerative Disease Research, Division of Molecular Medicine, Ruder Boskovic Institute, 10000 Zagreb, Croatia; (L.V.); (S.H.)
| | - Jasna Kriz
- CERVO Research Centre, Laval University, Quebec City, QC G1J 2G3, Canada; (A.A.C.); (J.K.); (J.-P.J.)
| | - Jean-Pierre Julien
- CERVO Research Centre, Laval University, Quebec City, QC G1J 2G3, Canada; (A.A.C.); (J.K.); (J.-P.J.)
| | | | | | - Boris Rogelj
- Department of Biotechnology, Jozef Stefan Institute, SI-1000 Ljubljana, Slovenia; (J.N.); (B.R.)
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Jason R. Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | | | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy;
| | - Silva Hecimovic
- Laboratory for Neurodegenerative Disease Research, Division of Molecular Medicine, Ruder Boskovic Institute, 10000 Zagreb, Croatia; (L.V.); (S.H.)
| | - Letizia Mazzini
- Department of Neurology and ALS Centre, University of Piemonte Orientale, Maggiore Della Carità Hospital, Corso Mazzini 18, 28100 Novara, Italy; (F.D.M.); (A.M.)
| | - Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, 34149 Trieste, Italy
| | - Ivana Munitic
- Laboratory for Molecular Immunology, Department of Biotechnology, University of Rijeka, R. Matejcic 2, 51000 Rijeka, Croatia;
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Van't Spijker HM, Almeida S. How villains are made: The translation of dipeptide repeat proteins in C9ORF72-ALS/FTD. Gene 2023; 858:147167. [PMID: 36621656 PMCID: PMC9928902 DOI: 10.1016/j.gene.2023.147167] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023]
Abstract
A hexanucleotide repeat expansion in the C9ORF72 gene is the most common genetic alteration associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These neurodegenerative diseases share genetic, clinical and pathological features. The mutation in C9ORF72 appears to drive pathogenesis through a combination of loss of C9ORF72 normal function and gain of toxic effects due to the repeat expansion, which result in aggregation prone expanded RNAs and dipeptide repeat (DPR) proteins. Studies in cellular and animal models indicate that the DPR proteins are the more toxic species. Thus, a large body of research has focused on identifying the cellular pathways most directly impacted by these toxic proteins, with the goal of characterizing disease pathogenesis and nominating potential targets for therapeutic development. The preventative block of the production of the toxic proteins before they can cause harm is a second strategy of intense focus. Despite the considerable amount of effort dedicated to this prophylactic approach, it is still unclear how the DPR proteins are synthesized from RNAs harboring repeat expansions. In this review, we summarize our current knowledge of the specific protein translation mechanisms shown to account for the synthesis of DPR proteins. We will then discuss how enhanced understanding of the composition of these toxic effectors could help in refining disease mechanisms, and paving the way to identify and design effective prophylactic therapies for C9ORF72 ALS-FTD.
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Affiliation(s)
- Heleen M Van't Spijker
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Sandra Almeida
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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Hu HY, Liu YJ. Sequestration of cellular native factors by biomolecular assemblies: Physiological or pathological? BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119360. [PMID: 36087810 DOI: 10.1016/j.bbamcr.2022.119360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
In addition to native-state structures, biomolecules often form condensed supramolecular assemblies or cellular membraneless organelles that are critical for cell life. These biomolecular assemblies, generally including liquid-like droplets (condensates) and amyloid-like aggregates, can sequester or recruit their interacting partners, so as to either modulate various cellular behaviors or even cause disorders. This review article summarizes recent advances in the sequestration of native factors by biomolecular assemblies and discusses their potential consequences on cellular function, homeostasis, and disease pathology.
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Affiliation(s)
- Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, PR China.
| | - Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
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PolyGA targets the ER stress-adaptive response by impairing GRP75 function at the MAM in C9ORF72-ALS/FTD. Acta Neuropathol 2022; 144:939-966. [PMID: 36121477 PMCID: PMC9547809 DOI: 10.1007/s00401-022-02494-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 08/18/2022] [Accepted: 09/06/2022] [Indexed: 01/26/2023]
Abstract
ER stress signaling is linked to the pathophysiological and clinical disease manifestations in amyotrophic lateral sclerosis (ALS). Here, we have investigated ER stress-induced adaptive mechanisms in C9ORF72-ALS/FTD, focusing on uncovering early endogenous neuroprotective mechanisms and the crosstalk between pathological and adaptive responses in disease onset and progression. We provide evidence for the early onset of ER stress-mediated adaptive response in C9ORF72 patient-derived motoneurons (MNs), reflected by the elevated increase in GRP75 expression. These transiently increased GRP75 levels enhance ER-mitochondrial association, boosting mitochondrial function and sustaining cellular bioenergetics during the initial stage of disease, thereby counteracting early mitochondrial deficits. In C9orf72 rodent neurons, an abrupt reduction in GRP75 expression coincided with the onset of UPR, mitochondrial dysfunction and the emergence of PolyGA aggregates, which co-localize with GRP75. Similarly, the overexpression of PolyGA in WT cortical neurons or C9ORF72 patient-derived MNs led to the sequestration of GRP75 within PolyGA inclusions, resulting in mitochondrial calcium (Ca2+) uptake impairments. Corroborating these findings, we found that PolyGA aggregate-bearing human post-mortem C9ORF72 hippocampal dentate gyrus neurons not only display reduced expression of GRP75 but also exhibit GRP75 sequestration within inclusions. Sustaining high GRP75 expression in spinal C9orf72 rodent MNs specifically prevented ER stress, normalized mitochondrial function, abrogated PolyGA accumulation in spinal MNs, and ameliorated ALS-associated behavioral phenotype. Taken together, our results are in line with the notion that neurons in C9ORF72-ALS/FTD are particularly susceptible to ER-mitochondrial dysfunction and that GRP75 serves as a critical endogenous neuroprotective factor. This neuroprotective pathway, is eventually targeted by PolyGA, leading to GRP75 sequestration, and its subsequent loss of function at the MAM, compromising mitochondrial function and promoting disease onset.
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Abstract
PURPOSE OF REVIEW ALS genetics are highly dynamic and of great interest for the ALS research community. Each year, by using ever-growing datasets and cutting-edge methodology, an array of novel ALS-associated genes and downstream pathomechanisms are discovered. The increasing plenty and complexity of insights warrants regular summary by-reviews. RECENT FINDINGS Most recent disease gene discoveries constitute the candidate and risk genes SPTLC1 , KANK1 , CAV1 , HTT , and WDR7 , as well as seven novel risk loci. Cell type and functional enrichment analyses enlighten the genetic basis of selective motor neuron vulnerability in ALS demonstrating high expression of ALS-associated genes in cortical motor neurons and highlight the pathogenic significance of cell-autonomous processes. Major pathomechanistic insights have been gained regarding known ALS genes/proteins, specifically C9orf72 , TDP43, ANXA11 , and KIF5A . The first ASO-based gene-specific therapy trials in familial forms of ALS have yielded equivocal results stressing the re-evaluation of pathomechanisms linked to SOD1 and C9orf72 mutations. SUMMARY The genetic and molecular basis of ALS is increasingly examined on single-cell resolution. In the past 2 years, the understanding of the downstream mechanisms of several ALS genes and TDP-43 proteinopathy has been considerably extended. These insights will result in novel gene specific therapy approaches for sporadic ALS and genetic subtypes.
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Houghton OH, Mizielinska S, Gomez-Suaga P. The Interplay Between Autophagy and RNA Homeostasis: Implications for Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Front Cell Dev Biol 2022; 10:838402. [PMID: 35573690 PMCID: PMC9096704 DOI: 10.3389/fcell.2022.838402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/14/2022] [Indexed: 01/18/2023] Open
Abstract
Amyotrophic lateral sclerosis and frontotemporal dementia are neurodegenerative disorders that lie on a disease spectrum, sharing genetic causes and pathology, and both without effective therapeutics. Two pathways that have been shown to play major roles in disease pathogenesis are autophagy and RNA homeostasis. Intriguingly, there is an increasing body of evidence suggesting a critical interplay between these pathways. Autophagy is a multi-stage process for bulk and selective clearance of malfunctional cellular components, with many layers of regulation. Although the majority of autophagy research focuses on protein degradation, it can also mediate RNA catabolism. ALS/FTD-associated proteins are involved in many stages of autophagy and autophagy-mediated RNA degradation, particularly converging on the clearance of persistent pathological stress granules. In this review, we will summarise the progress in understanding the autophagy-RNA homeostasis interplay and how that knowledge contributes to our understanding of the pathobiology of ALS/FTD.
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Affiliation(s)
- O H Houghton
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom.,UK Dementia Research Institute at King's College London, London, United Kingdom
| | - S Mizielinska
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom.,UK Dementia Research Institute at King's College London, London, United Kingdom
| | - P Gomez-Suaga
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom.,Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Enfermería y Terapia Ocupacional, Universidad de Extremadura, Cáceres, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Universitario de Investigación Biosanitaria de Extremadura (INUBE), Cáceres, Spain
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Liu F, Morderer D, Wren MC, Vettleson-Trutza SA, Wang Y, Rabichow BE, Salemi MR, Phinney BS, Oskarsson B, Dickson DW, Rossoll W. Proximity proteomics of C9orf72 dipeptide repeat proteins identifies molecular chaperones as modifiers of poly-GA aggregation. Acta Neuropathol Commun 2022; 10:22. [PMID: 35164882 PMCID: PMC8842533 DOI: 10.1186/s40478-022-01322-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 12/14/2022] Open
Abstract
The most common inherited cause of two genetically and clinico-pathologically overlapping neurodegenerative diseases, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), is the presence of expanded GGGGCC intronic hexanucleotide repeats in the C9orf72 gene. Aside from haploinsufficiency and toxic RNA foci, another non-exclusive disease mechanism is the non-canonical translation of the repeat RNA into five different dipeptide repeat proteins (DPRs), which form neuronal inclusions in affected patient brains. While evidence from cellular and animal models supports a toxic gain-of-function of pathologic poly-GA, poly-GR, and poly-PR aggregates in promoting deposition of TDP-43 pathology and neurodegeneration in affected brain areas, the relative contribution of DPRs to the disease process in c9FTD/ALS patients remains unclear. Here we have used the proximity-dependent biotin identification (BioID) proximity proteomics approach to investigate the formation and collective composition of DPR aggregates using cellular models. While interactomes of arginine rich poly-GR and poly-PR aggregates overlapped and were enriched for nucleolar and ribosomal proteins, poly-GA aggregates demonstrated a distinct association with proteasomal components, molecular chaperones (HSPA1A/HSP70, HSPA8/HSC70, VCP/p97), co-chaperones (BAG3, DNAJA1A) and other factors that regulate protein folding and degradation (SQSTM1/p62, CALR, CHIP/STUB1). Experiments in cellular models of poly-GA pathology show that molecular chaperones and co-chaperones are sequestered to the periphery of dense cytoplasmic aggregates, causing depletion from their typical cellular localization. Their involvement in the pathologic process is confirmed in autopsy brain tissue, where HSPA8, BAG3, VCP, and its adapter protein UBXN6 show a close association with poly-GA aggregates in the frontal cortex, temporal cortex, and hippocampus of c9FTLD and c9ALS cases. The association of heat shock proteins and co-chaperones with poly-GA led us to investigate their potential role in reducing its aggregation. We identified HSP40 co-chaperones of the DNAJB family as potent modifiers that increased the solubility of poly-GA, highlighting a possible novel therapeutic avenue and a central role of molecular chaperones in the pathogenesis of human C9orf72-linked diseases.
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