1
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Fare CM, Rothstein JD. Nuclear pore dysfunction and disease: a complex opportunity. Nucleus 2024; 15:2314297. [PMID: 38383349 PMCID: PMC10883112 DOI: 10.1080/19491034.2024.2314297] [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: 11/27/2023] [Accepted: 01/30/2024] [Indexed: 02/23/2024] Open
Abstract
The separation of genetic material from bulk cytoplasm has enabled the evolution of increasingly complex organisms, allowing for the development of sophisticated forms of life. However, this complexity has created new categories of dysfunction, including those related to the movement of material between cellular compartments. In eukaryotic cells, nucleocytoplasmic trafficking is a fundamental biological process, and cumulative disruptions to nuclear integrity and nucleocytoplasmic transport are detrimental to cell survival. This is particularly true in post-mitotic neurons, where nuclear pore injury and errors to nucleocytoplasmic trafficking are strongly associated with neurodegenerative disease. In this review, we summarize the current understanding of nuclear pore biology in physiological and pathological contexts and discuss potential therapeutic approaches for addressing nuclear pore injury and dysfunctional nucleocytoplasmic transport.
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Affiliation(s)
- Charlotte M Fare
- Department of Neurology and Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Jeffrey D Rothstein
- Department of Neurology and Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
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2
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Lin CY, Wu HE, Weng EFJ, Wu HC, Su TP, Wang SM. Fluvoxamine Exerts Sigma-1R to Rescue Autophagy via Pom121-Mediated Nucleocytoplasmic Transport of TFEB. Mol Neurobiol 2024; 61:5282-5294. [PMID: 38180612 PMCID: PMC11249700 DOI: 10.1007/s12035-023-03885-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 12/12/2023] [Indexed: 01/06/2024]
Abstract
Expansion of the GGGGCC-RNA repeat is a known cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), which currently have no cure. Recent studies have indicated the activation of Sigma-1 receptor plays an important role in providing neuroprotection, especially in ALS and Alzheimer's disease. Nevertheless, the mechanisms underlying Sigma-1R activation and its effect on (G4C2)n-RNA-induced cell death remain unclear. In this study, we demonstrated that fluvoxamine is a Sigma-1R agonist that can increase chaperone activity and stabilize the protein expression of Pom121 in (G4C2)31-RNA-expressing NSC34 cells, leading to increased colocalization at the nuclear envelope. Interestingly, fluvoxamine treatment increased Pom121 protein expression without affecting transcription. In C9orf72-ALS, the nuclear translocation of TFEB autophagy factor decreased owing to nucleocytoplasmic transport defects. Our results showed that pretreatment of NSC34 cells with fluvoxamine promoted the shuttling of TFEB into the nucleus and elevated the expression of LC3-II compared to the overexpression of (G4C2)31-RNA alone. Additionally, even when used alone, fluvoxamine increases Pom121 expression and TFEB translocation. To summarize, fluvoxamine may act as a promising repurposed medicine for patients with C9orf72-ALS, as it stabilizes the nucleoporin Pom121 and promotes the translocation of TFEB in (G4C2)31-RNA-expressing NSC34 cells.
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Affiliation(s)
- Chun-Yu Lin
- School of Medicine, China Medical University, Taichung, Taiwan
- Neuroscience and Brain Disease Center, China Medical University, Taichung, Taiwan
| | - Hsiang-En Wu
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Eddie Feng-Ju Weng
- Neuroscience and Brain Disease Center, China Medical University, Taichung, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, 404333, Taiwan
| | - Hsuan-Cheng Wu
- Neuroscience and Brain Disease Center, China Medical University, Taichung, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, 404333, Taiwan
| | - Tsung-Ping Su
- Cellular Pathobiology Section, Integrative Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Suite 3512, 333 Cassell Drive, Baltimore, MD, 21224, USA
| | - Shao-Ming Wang
- Neuroscience and Brain Disease Center, China Medical University, Taichung, Taiwan.
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, 404333, Taiwan.
- Department of Neurology, China Medical University Hospital, Taichung, Taiwan.
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3
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Celona B, Salomonsson SE, Wu H, Dang B, Kratochvil HT, Clelland CD, DeGrado WF, Black BL. Zfp106 binds to G-quadruplex RNAs and inhibits RAN translation and formation of RNA foci caused by G4C2 repeats. Proc Natl Acad Sci U S A 2024; 121:e2220020121. [PMID: 39042693 PMCID: PMC11295049 DOI: 10.1073/pnas.2220020121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 06/14/2024] [Indexed: 07/25/2024] Open
Abstract
Expansion of intronic GGGGCC repeats in the C9orf72 gene causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Transcription of the expanded repeats results in the formation of RNA-containing nuclear foci and altered RNA metabolism. In addition, repeat-associated non-AUG (RAN) translation of the expanded GGGGCC-repeat sequence results in the production of highly toxic dipeptide-repeat (DPR) proteins. GGGGCC repeat-containing transcripts form G-quadruplexes, which are associated with formation of RNA foci and RAN translation. Zfp106, an RNA-binding protein essential for motor neuron survival in mice, suppresses neurotoxicity in a Drosophila model of C9orf72 ALS. Here, we show that Zfp106 inhibits formation of RNA foci and significantly reduces RAN translation caused by GGGGCC repeats in cultured mammalian cells, and we demonstrate that Zfp106 coexpression reduces the levels of DPRs in C9orf72 patient-derived cells. Further, we show that Zfp106 binds to RNA G-quadruplexes and causes a conformational change in the G-quadruplex structure formed by GGGGCC repeats. Together, these data demonstrate that Zfp106 suppresses the formation of RNA foci and DPRs caused by GGGGCC repeats and suggest that the G-quadruplex RNA-binding function of Zfp106 contributes to its suppression of GGGGCC repeat-mediated cytotoxicity.
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Affiliation(s)
- Barbara Celona
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
| | - Sally E. Salomonsson
- Weill Institute for Neurosciences, University of California, San Francisco, CA94143
- Memory & Aging Center, Department of Neurology, University of California, San Francisco, CA94143
| | - Haifan Wu
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA94143
| | - Bobo Dang
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA94143
| | - Huong T. Kratochvil
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA94143
| | - Claire D. Clelland
- Weill Institute for Neurosciences, University of California, San Francisco, CA94143
- Memory & Aging Center, Department of Neurology, University of California, San Francisco, CA94143
| | - William F. DeGrado
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA94143
| | - Brian L. Black
- Cardiovascular Research Institute, University of California, San Francisco, CA94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA94143
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4
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Buggiani J, Meinnel T, Giglione C, Frottin F. Advances in nuclear proteostasis of metazoans. Biochimie 2024:S0300-9084(24)00081-6. [PMID: 38642824 DOI: 10.1016/j.biochi.2024.04.006] [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: 01/29/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024]
Abstract
The proteostasis network and associated protein quality control (PQC) mechanisms ensure proteome functionality and are essential for cell survival. A distinctive feature of eukaryotic cells is their high degree of compartmentalization, requiring specific and adapted proteostasis networks for each compartment. The nucleus, essential for maintaining the integrity of genetic information and gene transcription, is one such compartment. While PQC mechanisms have been investigated for decades in the cytoplasm and the endoplasmic reticulum, our knowledge of nuclear PQC pathways is only emerging. Recent developments in the field have underscored the importance of spatially managing aberrant proteins within the nucleus. Upon proteotoxic stress, misfolded proteins and PQC effectors accumulate in various nuclear membrane-less organelles. Beyond bringing together effectors and substrates, the biophysical properties of these organelles allow novel PQC functions. In this review, we explore the specificity of the nuclear compartment, the effectors of the nuclear proteostasis network, and the PQC roles of nuclear membrane-less organelles in metazoans.
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Affiliation(s)
- Julia Buggiani
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Thierry Meinnel
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Carmela Giglione
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Frédéric Frottin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France.
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5
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Chen M, Guo X, Guo J, Shi C, Wu Y, Chen L, Mao R, Fan Y. Cytoplasmic Accumulation of Histones Induced by BET Inhibition Protects Cells from C9orf72 Poly(PR)-Induced Cell Death. Adv Biol (Weinh) 2024; 8:e2300334. [PMID: 38213020 DOI: 10.1002/adbi.202300334] [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: 07/14/2023] [Revised: 11/16/2023] [Indexed: 01/13/2024]
Abstract
Repeat dipeptides such as poly(proline-arginine) (polyPR) are generated from the hexanucleotide GGGGCC repeat expansions in the C9orf72 gene. These dipeptides are often considered as the genetic cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In the study, fluorescein isothiocyanate (FITC) labeled PR20 is used to investigate PR20-induced cell death. The findings reveal that the cell death induced by PR20 is dependent on its nuclear distribution and can be blocked by a nuclear import inhibitor called importazole. Further investigation reveals that BRD4 inhibitors, such as JQ-1 and I-BET762, restrict cytoplasmic localization of PR20, thereby reducing its cytotoxic effect. Mechanistically, the inhibition of BRD4 leads to an increase in the expression of numerous histones, resulting in the accumulation of histones in the cytoplasm. These cytoplasmic histones associate with PR20 and limit its distribution within the nucleus. Notably, the ectopic expression of histones alone is enough to confer protection to cells treated with PR20. In addition, phenylephrine (PE) induces cellular hypertrophy and cytoplasmic distribution of histone, which also helps protect cells from PR20-induced cell death. The research suggests that temporarily inducing the presence of cytoplasmic histones may alleviate the neurotoxic effects of dipeptide repeat proteins.
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Affiliation(s)
- Miaomiao Chen
- Laboratory of Medical Science, School of Medicine, Nantong University, Nantong, 226001, China
| | - Xiaohong Guo
- Department of Pathogenic Biology, School of Medicine, Nantong University, Nantong, 226001, China
| | - Jinjing Guo
- Department of Pathogenic Biology, School of Medicine, Nantong University, Nantong, 226001, China
| | - Conglin Shi
- Department of Pathogenic Biology, School of Medicine, Nantong University, Nantong, 226001, China
| | - Yuanyuan Wu
- Laboratory of Medical Science, School of Medicine, Nantong University, Nantong, 226001, China
| | - Liuting Chen
- Department of Pathogenic Biology, School of Medicine, Nantong University, Nantong, 226001, China
| | - Renfang Mao
- Department of Pathophysiology, School of Medicine, Nantong University, Nantong, 226001, China
| | - Yihui Fan
- Laboratory of Medical Science, School of Medicine, Nantong University, Nantong, 226001, China
- Department of Pathogenic Biology, School of Medicine, Nantong University, Nantong, 226001, China
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6
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Kassouf T, Shrivastava R, Meszka I, Bailly A, Polanowska J, Trauchessec H, Mandrioli J, Carra S, Xirodimas DP. Targeting the NEDP1 enzyme to ameliorate ALS phenotypes through stress granule disassembly. SCIENCE ADVANCES 2023; 9:eabq7585. [PMID: 37000881 PMCID: PMC10065448 DOI: 10.1126/sciadv.abq7585] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
The elimination of aberrant inclusions is regarded as a therapeutic approach in neurodegeneration. In amyotrophic lateral sclerosis (ALS), mutations in proteins found within cytoplasmic condensates called stress granules (SGs) are linked to the formation of pathological SGs, aberrant protein inclusions, and neuronal toxicity. We found that inhibition of NEDP1, the enzyme that processes/deconjugates the ubiquitin-like molecule NEDD8, promotes the disassembly of physiological and pathological SGs. Reduction in poly(ADP-ribose) polymerase1 activity through hyper-NEDDylation is a key mechanism for the observed phenotype. These effects are related to improved cell survival in human cells, and in C. elegans, nedp1 deletion ameliorates ALS phenotypes related to animal motility. Our studies reveal NEDP1 as potential therapeutic target for ALS, correlated to the disassembly of pathological SGs.
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Affiliation(s)
| | | | - Igor Meszka
- CRBM, Univ. Montpellier, CNRS, Montpellier, France
| | | | | | | | - Jessica Mandrioli
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia,G. Campi 287, 41125 Modena, Italy
| | - Serena Carra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia,G. Campi 287, 41125 Modena, Italy
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7
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Mauthe M, Kampinga HH, Hipp MS, Reggiori F. Digest it all: the lysosomal turnover of cytoplasmic aggregates. Trends Biochem Sci 2023; 48:216-228. [PMID: 36280494 DOI: 10.1016/j.tibs.2022.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/29/2022] [Accepted: 09/29/2022] [Indexed: 02/18/2023]
Abstract
Aggrephagy describes the selective lysosomal transport and turnover of cytoplasmic protein aggregates by macro-autophagy. In this process, protein aggregates and conglomerates are polyubiquitinated and then sequestered by autophagosomes. Soluble selective autophagy receptors (SARs) are central to aggrephagy and physically bind to both ubiquitin and the autophagy machinery, thus linking the cargo to the forming autophagosomal membrane. Because the accumulation of protein aggregates is associated with cytotoxicity in several diseases, a better molecular understanding of aggrephagy might provide a conceptual framework to develop therapeutic strategies aimed at delaying the onset of these pathologies by preventing the buildup of potentially toxic aggregates. We review recent advances in our knowledge about the mechanism of aggrephagy.
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Affiliation(s)
- Mario Mauthe
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Harm H Kampinga
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Mark S Hipp
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedicine, Aarhus University, Aarhus, Denmark; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark.
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8
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Nabariya DK, Heinz A, Derksen S, Krauß S. Intracellular and intercellular transport of RNA organelles in CXG repeat disorders: The strength of weak ties. Front Mol Biosci 2022; 9:1000932. [PMID: 36589236 PMCID: PMC9800848 DOI: 10.3389/fmolb.2022.1000932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
RNA is a vital biomolecule, the function of which is tightly spatiotemporally regulated. RNA organelles are biological structures that either membrane-less or surrounded by membrane. They are produced by the all the cells and indulge in vital cellular mechanisms. They include the intracellular RNA granules and the extracellular exosomes. RNA granules play an essential role in intracellular regulation of RNA localization, stability and translation. Aberrant regulation of RNA is connected to disease development. For example, in microsatellite diseases such as CXG repeat expansion disorders, the mutant CXG repeat RNA's localization and function are affected. RNA is not only transported intracellularly but can also be transported between cells via exosomes. The loading of the exosomes is regulated by RNA-protein complexes, and recent studies show that cytosolic RNA granules and exosomes share common content. Intracellular RNA granules and exosome loading may therefore be related. Exosomes can also transfer pathogenic molecules of CXG diseases from cell to cell, thereby driving disease progression. Both intracellular RNA granules and extracellular RNA vesicles may serve as a source for diagnostic and treatment strategies. In therapeutic approaches, pharmaceutical agents may be loaded into exosomes which then transport them to the desired cells/tissues. This is a promising target specific treatment strategy with few side effects. With respect to diagnostics, disease-specific content of exosomes, e.g., RNA-signatures, can serve as attractive biomarker of central nervous system diseases detecting early physiological disturbances, even before symptoms of neurodegeneration appear and irreparable damage to the nervous system occurs. In this review, we summarize the known function of cytoplasmic RNA granules and extracellular vesicles, as well as their role and dysfunction in CXG repeat expansion disorders. We also provide a summary of established protocols for the isolation and characterization of both cytoplasmic and extracellular RNA organelles.
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Affiliation(s)
| | | | | | - Sybille Krauß
- Human Biology/Neurobiology, Institute of Biology, Faculty IV, School of Science and Technology, University of Siegen, Siegen, Germany
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9
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Marlin E, Viu-Idocin C, Arrasate M, Aragón T. The Role and Therapeutic Potential of the Integrated Stress Response in Amyotrophic Lateral Sclerosis. Int J Mol Sci 2022; 23:ijms23147823. [PMID: 35887167 PMCID: PMC9321386 DOI: 10.3390/ijms23147823] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 02/06/2023] Open
Abstract
In amyotrophic lateral sclerosis (ALS) patients, loss of cellular homeostasis within cortical and spinal cord motor neurons triggers the activation of the integrated stress response (ISR), an intracellular signaling pathway that remodels translation and promotes a gene expression program aimed at coping with stress. Beyond its neuroprotective role, under regimes of chronic or excessive stress, ISR can also promote cell/neuronal death. Given the two-edged sword nature of ISR, many experimental attempts have tried to establish the therapeutic potential of ISR enhancement or inhibition in ALS. This review discusses the complex interplay between ISR and disease progression in different models of ALS, as well as the opportunities and limitations of ISR modulation in the hard quest to find an effective therapy for ALS.
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Affiliation(s)
- Elías Marlin
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain;
- Gene Therapy and Regulation of Gene Expression Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain
- School of Medicine, University of Navarra, 31008 Pamplona, Spain
- Neuroscience Department, Navarra Institute for Health Research (IdiSNA), University of Navarra, 31008 Pamplona, Spain
| | | | - Montserrat Arrasate
- Neuroscience Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain;
- School of Medicine, University of Navarra, 31008 Pamplona, Spain
- Neuroscience Department, Navarra Institute for Health Research (IdiSNA), University of Navarra, 31008 Pamplona, Spain
- Correspondence: (M.A.); (T.A.)
| | - Tomás Aragón
- Gene Therapy and Regulation of Gene Expression Program, Center for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain
- Neuroscience Department, Navarra Institute for Health Research (IdiSNA), University of Navarra, 31008 Pamplona, Spain
- Correspondence: (M.A.); (T.A.)
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10
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Coyne AN, Rothstein JD. Nuclear pore complexes - a doorway to neural injury in neurodegeneration. Nat Rev Neurol 2022; 18:348-362. [PMID: 35488039 PMCID: PMC10015220 DOI: 10.1038/s41582-022-00653-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2022] [Indexed: 12/13/2022]
Abstract
The genetic underpinnings and end-stage pathological hallmarks of neurodegenerative diseases are increasingly well defined, but the cellular pathophysiology of disease initiation and propagation remains poorly understood, especially in sporadic forms of these diseases. Altered nucleocytoplasmic transport is emerging as a prominent pathomechanism of multiple neurodegenerative diseases, including amyotrophic lateral sclerosis, Alzheimer disease, frontotemporal dementia and Huntington disease. The nuclear pore complex (NPC) and interactions between its individual nucleoporin components and nuclear transport receptors regulate nucleocytoplasmic transport, as well as genome organization and gene expression. Specific nucleoporin abnormalities have been identified in sporadic and familial forms of neurodegenerative disease, and these alterations are thought to contribute to disrupted nucleocytoplasmic transport. The specific nucleoporins and nucleocytoplasmic transport proteins that have been linked to different neurodegenerative diseases are partially distinct, suggesting that NPC injury contributes to the cellular specificity of neurodegenerative disease and could be an early initiator of the pathophysiological cascades that underlie neurodegenerative disease. This concept is consistent with the fact that rare genetic mutations in some nucleoporins cause cell-type-specific neurological disease. In this Review, we discuss nucleoporin and NPC disruptions and consider their impact on cellular function and the pathophysiology of neurodegenerative disease.
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Affiliation(s)
- Alyssa N Coyne
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Jeffrey D Rothstein
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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11
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Garrett LR, Niccoli T. Frontotemporal Dementia and Glucose Metabolism. Front Neurosci 2022; 16:812222. [PMID: 35281504 PMCID: PMC8906510 DOI: 10.3389/fnins.2022.812222] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/18/2022] [Indexed: 12/02/2022] Open
Abstract
Frontotemporal dementia (FTD), hallmarked by antero-temporal degeneration in the human brain, is the second most common early onset dementia. FTD is a diverse disease with three main clinical presentations, four different identified proteinopathies and many disease-associated genes. The exact pathophysiology of FTD remains to be elucidated. One common characteristic all forms of FTD share is the dysregulation of glucose metabolism in patients’ brains. The brain consumes around 20% of the body’s energy supply and predominantly utilizes glucose as a fuel. Glucose metabolism dysregulation could therefore be extremely detrimental for neuronal health. Research into the association between glucose metabolism and dementias has recently gained interest in Alzheimer’s disease. FTD also presents with glucose metabolism dysregulation, however, this remains largely an unexplored area. A better understanding of the link between FTD and glucose metabolism may yield further insight into FTD pathophysiology and aid the development of novel therapeutics. Here we review our current understanding of FTD and glucose metabolism in the brain and discuss the evidence of impaired glucose metabolism in FTD. Lastly, we review research potentially suggesting a causal relationship between FTD proteinopathies and impaired glucose metabolism in FTD.
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12
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Chandra S, Lusk CP. Emerging Connections between Nuclear Pore Complex Homeostasis and ALS. Int J Mol Sci 2022; 23:1329. [PMID: 35163252 PMCID: PMC8835831 DOI: 10.3390/ijms23031329] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 12/26/2022] Open
Abstract
Developing effective treatments for neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) requires understanding of the underlying pathomechanisms that contribute to the motor neuron loss that defines the disease. As it causes the largest fraction of familial ALS cases, considerable effort has focused on hexanucleotide repeat expansions in the C9ORF72 gene, which encode toxic repeat RNA and dipeptide repeat (DPR) proteins. Both the repeat RNA and DPRs interact with and perturb multiple elements of the nuclear transport machinery, including shuttling nuclear transport receptors, the Ran GTPase and the nucleoporin proteins (nups) that build the nuclear pore complex (NPC). Here, we consider recent work that describes changes to the molecular composition of the NPC in C9ORF72 model and patient neurons in the context of quality control mechanisms that function at the nuclear envelope (NE). For example, changes to NPC structure may be caused by the dysregulation of a conserved NE surveillance pathway mediated by the endosomal sorting complexes required for the transport protein, CHMP7. Thus, these studies are introducing NE and NPC quality control pathways as key elements in a pathological cascade that leads to C9ORF72 ALS, opening entirely new experimental avenues and possibilities for targeted therapeutic intervention.
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Affiliation(s)
| | - C. Patrick Lusk
- Department of Cell Biology, Yale School of Medicine, 295 Congress Ave, New Haven, CT 06520, USA;
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13
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Rossi S, Cozzolino M. Dysfunction of RNA/RNA-Binding Proteins in ALS Astrocytes and Microglia. Cells 2021; 10:cells10113005. [PMID: 34831228 PMCID: PMC8616248 DOI: 10.3390/cells10113005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 12/24/2022] Open
Abstract
Amyotrophic Lateral Sclerosis is a neurological disease that primarily affects motor neurons in the cortex, brainstem, and spinal cord. The process that leads to motor neuron degeneration is strongly influenced by non-motor neuronal events that occur in a variety of cell types. Among these, neuroinflammatory processes mediated by activated astrocytes and microglia play a relevant role. In recent years, it has become clear that dysregulation of essential steps of RNA metabolism, as a consequence of alterations in RNA-binding proteins (RBPs), is a central event in the degeneration of motor neurons. Yet, a causal link between dysfunctional RNA metabolism and the neuroinflammatory processes mediated by astrocytes and microglia in ALS has been poorly defined. In this review, we will discuss the available evidence showing that RBPs and associated RNA processing are affected in ALS astrocytes and microglia, and the possible mechanisms involved in these events.
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