1
|
Wang H, Zeng R. Aberrant protein aggregation in amyotrophic lateral sclerosis. J Neurol 2024:10.1007/s00415-024-12485-z. [PMID: 38869826 DOI: 10.1007/s00415-024-12485-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: 03/12/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/14/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease. As its pathological mechanisms are not well understood, there are no efficient therapeutics for it at present. While it is highly heterogenous both etiologically and clinically, it has a common salient hallmark, i.e., aberrant protein aggregation (APA). The upstream pathogenesis and the downstream effects of APA in ALS are sophisticated and the investigation of this pathology would be of consequence for understanding ALS. In this paper, the pathomechanism of APA in ALS and the candidate treatment strategies for it are discussed.
Collapse
Affiliation(s)
- Huaixiu Wang
- Department Neurology, Shanxi Provincial Peoples Hospital: Fifth Hospital of Shanxi Medical University, Taiyuan, 030012, China.
- Beijing Ai-Si-Kang Medical Technology Co. Ltd., No. 18 11th St Economical & Technological Development Zone, Beijing, 100176, China.
| | - Rong Zeng
- Department Neurology, Shanxi Provincial Peoples Hospital: Fifth Hospital of Shanxi Medical University, Taiyuan, 030012, China
| |
Collapse
|
2
|
Shojaei M, Zhou Q, Palumbo G, Schaefer R, Kaskinoro J, Vehmaan-Kreula P, Bartenstein P, Brendel M, Edbauer D, Lindner S. Development and Preclinical Evaluation of a Copper-64-Labeled Antibody Targeting Glycine-Alanine Dipeptides for PET Imaging of C9orf72-Associated Amyotrophic Lateral Sclerosis/Frontotemporal Dementia. ACS Pharmacol Transl Sci 2024; 7:1404-1414. [PMID: 38751620 PMCID: PMC11091963 DOI: 10.1021/acsptsci.4c00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 05/18/2024]
Abstract
Aggregating poly(glycine-alanine) (poly-GA) is derived from the unconventional translation of the pathogenic intronic hexanucleotide repeat expansion in the C9orf72 gene, which is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Poly-GA accumulates predominantly in neuronal cytoplasmic inclusions unique to C9orf72 ALS/FTD patients. Poly-GA is, therefore, a promising target for PET/CT imaging of FTD/ALS to monitor disease progression and therapeutic interventions. A novel 64Cu-labeled anti-GA antibody (mAb1A12) targeting the poly-GA protein was developed and evaluated in a transgenic mouse model. It was obtained with high radiochemical purity (RCP), radiochemical yield (RCY), and specific activity, and showed high stability in vitro and ex vivo and specifically bound to poly-GA. The affinity of NODAGA-mAb1A12 for poly-GA was not affected by this modification. [64Cu]Cu-NODAGA-mAb1A12 was injected into transgenic mice expressing GFP-(GA)175 in excitatory neurons driven by Camk2a-Cre and in control littermates. PET/CT imaging was performed at 2, 20, and 40 h post-injection (p.i.) and revealed a higher accumulation in the cortex in transgenic mice than in wild-type mice, as reflected by higher standardized uptake value ratios (SUVR) using the cerebellum as the reference region. The organs were isolated for biodistribution and ex vivo autoradiography. Autoradiography revealed a higher cortex-to-cerebellum ratio in the transgenic mice than in the controls. Results from autoradiography were validated by immunohistochemistry and poly-GA immunoassays. Moreover, we confirmed antibody uptake in the CNS in a pharmacokinetic study of the perfused tissues. In summary, [64Cu]Cu-NODAGA-mAb1A12 demonstrated favorable in vitro characteristics and an increased relative binding in poly-GA transgenic mice compared to wild-type mice in vivo. Our results with this first-in-class radiotracer suggested that targeting poly-GA is a promising approach for PET/CT imaging in FTD/ALS.
Collapse
Affiliation(s)
- Monireh Shojaei
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
| | - Qihui Zhou
- German
Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Giovanna Palumbo
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
| | - Rebecca Schaefer
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
| | | | | | - Peter Bartenstein
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
- Munich
Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Matthias Brendel
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
- German
Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Munich
Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Dieter Edbauer
- German
Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
- Munich
Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Simon Lindner
- Department
of Nuclear Medicine, University Hospital,
LMU Munich, 81377 Munich, Germany
| |
Collapse
|
3
|
Cicardi ME, Kankate V, Sriramoji S, Krishnamurthy K, Markandaiah SS, Verdone BM, Girdhar A, Nelson A, Rivas LB, Boehringer A, Haeusler AR, Pasinelli P, Guo L, Trotti D. The nuclear import receptor Kapβ2 modifies neurotoxicity mediated by poly(GR) in C9orf72-linked ALS/FTD. Commun Biol 2024; 7:376. [PMID: 38548902 PMCID: PMC10978903 DOI: 10.1038/s42003-024-06071-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 03/19/2024] [Indexed: 04/01/2024] Open
Abstract
Expanded intronic G4C2 repeats in the C9ORF72 gene cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These intronic repeats are translated through a non-AUG-dependent mechanism into five different dipeptide repeat proteins (DPRs), including poly-glycine-arginine (GR), which is aggregation-prone and neurotoxic. Here, we report that Kapβ2 and GR interact, co-aggregating, in cultured neurons in-vitro and CNS tissue in-vivo. Importantly, this interaction significantly decreased the risk of death of cultured GR-expressing neurons. Downregulation of Kapβ2 is detrimental to their survival, whereas increased Kapβ2 levels mitigated GR-mediated neurotoxicity. As expected, GR-expressing neurons displayed TDP-43 nuclear loss. Raising Kapβ2 levels did not restore TDP-43 into the nucleus, nor did alter the dynamic properties of GR aggregates. Overall, our findings support the design of therapeutic strategies aimed at up-regulating Kapβ2 expression levels as a potential new avenue for contrasting neurodegeneration in C9orf72-ALS/FTD.
Collapse
Affiliation(s)
- M E Cicardi
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - V Kankate
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - S Sriramoji
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - K Krishnamurthy
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - S S Markandaiah
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - B M Verdone
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - A Girdhar
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - A Nelson
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - L B Rivas
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - A Boehringer
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - A R Haeusler
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - P Pasinelli
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - L Guo
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - D Trotti
- Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
4
|
Uy G, Farrell LN, Faheem SF, Kinne LE, Adore MG, Im SH, Fairman R. The Effects of poly-GA and poly-PR C9orf72 Dipeptide Repeats on Sleep Patterns in Drosophila melanogaster. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.000973. [PMID: 38495583 PMCID: PMC10943360 DOI: 10.17912/micropub.biology.000973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/31/2024] [Accepted: 03/01/2024] [Indexed: 03/19/2024]
Abstract
C9orf72 is the most common familial gene associated with amyotrophic lateral sclerosis (ALS). Dipeptide repeats (DPRs) encoded by an expanded nucleotide repeat sequence in the C9orf72 gene were found in the sleep-related neurons of patients, indicating a role of DPRs in ALS-associated sleep disruptions. Poly-GA or poly-PR DPRs were expressed in male Drosophila melanogaster to study their effect on sleep . Poly-PR expression caused sleep disruptions while poly-GA expression did not. This study validates the use of Drosophila as an in vivo model system for exploring the roles of DPRs in perturbing the underlying molecular mechanisms in sleep regulation.
Collapse
Affiliation(s)
- Genevieve Uy
- Chemistry, Haverford College, Philadelphia, Pennsylvania, United States
| | - Laura N. Farrell
- Neuroscience, Haverford College, Philadelphia, Pennsylvania, United States
| | - Syeda F. Faheem
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Lauren E. Kinne
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Madison G. Adore
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Seol Hee Im
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| | - Robert Fairman
- Biology, Haverford College, Philadelphia, Pennsylvania, United States
| |
Collapse
|
5
|
He D, Xu Y, Liu M, Cui L. The Inflammatory Puzzle: Piecing together the Links between Neuroinflammation and Amyotrophic Lateral Sclerosis. Aging Dis 2024; 15:96-114. [PMID: 37307819 PMCID: PMC10796096 DOI: 10.14336/ad.2023.0519] [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: 04/03/2023] [Accepted: 05/19/2023] [Indexed: 06/14/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that has a complex genetic basis. Through advancements in genetic screening, researchers have identified more than 40 mutant genes associated with ALS, some of which impact immune function. Neuroinflammation, with abnormal activation of immune cells and excessive production of inflammatory cytokines in the central nervous system, significantly contributes to the pathophysiology of ALS. In this review, we examine recent evidence on the involvement of ALS-associated mutant genes in immune dysregulation, with a specific focus on the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway and N6-methyladenosine (m6A)-mediated immune regulation in the context of neurodegeneration. We also discuss the perturbation of immune cell homeostasis in both the central nervous system and peripheral tissues in ALS. Furthermore, we explore the advancements made in the emerging genetic and cell-based therapies for ALS. This review underscores the complex relationship between ALS and neuroinflammation, highlighting the potential to identify modifiable factors for therapeutic intervention. A deeper understanding of the connection between neuroinflammation and the risk of ALS is crucial for advancing effective treatments for this debilitating disorder.
Collapse
Affiliation(s)
- Di He
- Department of Neurology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC), Beijing, China
| | - Yan Xu
- Department of Neurology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC), Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC), Beijing, China
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC), Beijing, China
| |
Collapse
|
6
|
Chong ZZ, Menkes DL, Souayah N. Pathogenesis underlying hexanucleotide repeat expansions in C9orf72 gene in amyotrophic lateral sclerosis. Rev Neurosci 2024; 35:85-97. [PMID: 37525497 DOI: 10.1515/revneuro-2023-0060] [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: 05/29/2023] [Accepted: 07/07/2023] [Indexed: 08/02/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disorder. Mutations in C9orf72 and the resulting hexanucleotide repeat (GGGGCC) expansion (HRE) has been identified as a major cause of familial ALS, accounting for about 40 % of familial and 6 % of sporadic cases of ALS in Western patients. The pathological outcomes of HRE expansion in ALS have been recognized as the results of two mechanisms that include both the toxic gain-of-function and loss-of-function of C9ORF72. The gain of toxicity results from RNA and dipeptide repeats (DPRs). The HRE can be bidirectionally transcribed into RNA foci, which can bind to and disrupt RNA splicing, transport, and translation. The DPRs that include poly-glycine-alanine, poly-glycine-proline, poly-glycine- arginine, poly-proline-alanine, and poly-proline-arginine can induce toxicity by direct binding and sequestrating other proteins to interfere rRNA synthesis, ribosome biogenesis, translation, and nucleocytoplasmic transport. The C9ORF72 functions through binding to its partners-Smith-Magenis chromosome regions 8 (SMCR8) and WD repeat-containing protein (WDR41). Loss of C9ORF72 function results in impairment of autophagy, deregulation of autoimmunity, increased stress, and disruption of nucleocytoplasmic transport. Further insight into the mechanism in C9ORF72 HRE pathogenesis will facilitate identifying novel and effective therapeutic targets for ALS.
Collapse
Affiliation(s)
- Zhao Zhong Chong
- Department of Neurology, Rutgers University, New Jersey Medical School, 185 S. Orange Ave, Newark, NJ 07103, USA
| | - Daniel L Menkes
- Department of Neurology, Oakland University William Beaumont School of Medicine, 3555 West 13 Mile Road, Suite N120, Royal Oak, MI 48073, USA
| | - Nizar Souayah
- Department of Neurology, Rutgers University, New Jersey Medical School, 90 Bergen Street DOC 8100, Newark, NJ 07101, USA
| |
Collapse
|
7
|
Khalil B, Linsenmeier M, Smith CL, Shorter J, Rossoll W. Nuclear-import receptors as gatekeepers of pathological phase transitions in ALS/FTD. Mol Neurodegener 2024; 19:8. [PMID: 38254150 PMCID: PMC10804745 DOI: 10.1186/s13024-023-00698-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/13/2023] [Indexed: 01/24/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders on a disease spectrum that are characterized by the cytoplasmic mislocalization and aberrant phase transitions of prion-like RNA-binding proteins (RBPs). The common accumulation of TAR DNA-binding protein-43 (TDP-43), fused in sarcoma (FUS), and other nuclear RBPs in detergent-insoluble aggregates in the cytoplasm of degenerating neurons in ALS/FTD is connected to nuclear pore dysfunction and other defects in the nucleocytoplasmic transport machinery. Recent advances suggest that beyond their canonical role in the nuclear import of protein cargoes, nuclear-import receptors (NIRs) can prevent and reverse aberrant phase transitions of TDP-43, FUS, and related prion-like RBPs and restore their nuclear localization and function. Here, we showcase the NIR family and how they recognize cargo, drive nuclear import, and chaperone prion-like RBPs linked to ALS/FTD. We also discuss the promise of enhancing NIR levels and developing potentiated NIR variants as therapeutic strategies for ALS/FTD and related neurodegenerative proteinopathies.
Collapse
Affiliation(s)
- Bilal Khalil
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, U.S.A
| | - Miriam Linsenmeier
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, U.S.A
| | - Courtney L Smith
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, U.S.A
- Mayo Clinic Graduate School of Biomedical Sciences, Neuroscience Track, Mayo Clinic, Jacksonville, FL, 32224, U.S.A
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, U.S.A..
| | - Wilfried Rossoll
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, U.S.A..
| |
Collapse
|
8
|
Ito H, Machida K, Hasumi M, Ueyama M, Nagai Y, Imataka H, Taguchi H. Reconstitution of C9orf72 GGGGCC repeat-associated non-AUG translation with purified human translation factors. Sci Rep 2023; 13:22826. [PMID: 38129650 PMCID: PMC10739749 DOI: 10.1038/s41598-023-50188-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/16/2023] [Indexed: 12/23/2023] Open
Abstract
Nucleotide repeat expansion of GGGGCC (G4C2) in the non-coding region of C9orf72 is the most common genetic cause underlying amyotrophic lateral sclerosis and frontotemporal dementia. Transcripts harboring this repeat expansion undergo the translation of dipeptide repeats via a non-canonical process known as repeat-associated non-AUG (RAN) translation. In order to ascertain the essential components required for RAN translation, we successfully recapitulated G4C2-RAN translation using an in vitro reconstituted translation system comprising human factors, namely the human PURE system. Our findings conclusively demonstrate that the presence of fundamental translation factors is sufficient to mediate the elongation from the G4C2 repeat. Furthermore, the initiation mechanism proceeded in a 5' cap-dependent manner, independent of eIF2A or eIF2D. In contrast to cell lysate-mediated RAN translation, where longer G4C2 repeats enhanced translation, we discovered that the expansion of the G4C2 repeats inhibited translation elongation using the human PURE system. These results suggest that the repeat RNA itself functions as a repressor of RAN translation. Taken together, our utilization of a reconstituted RAN translation system employing minimal factors represents a distinctive and potent approach for elucidating the intricacies underlying RAN translation mechanism.
Collapse
Grants
- JPMJFS2112 Japan Science and Technology Agency
- JP26116002 Ministry of Education, Culture, Sports, Science and Technology
- JP18H03984 Ministry of Education, Culture, Sports, Science and Technology
- JP21H04763 Ministry of Education, Culture, Sports, Science and Technology
- JP20H05925 Ministry of Education, Culture, Sports, Science and Technology
- 2019-25 Mitsubishi Foundation
- 2019 Uehara Memorial Foundation
Collapse
Affiliation(s)
- Hayato Ito
- School of Life Science and Technology, Tokyo Institute of Technology, S2-19, Nagatsuta 4259, Midori-ku, Yokohama, 226-8501, Japan
| | - Kodai Machida
- Graduate School of Engineering, University of Hyogo, Shosha, 2167, Himeji, Hyogo, 671-2280, Japan
| | - Mayuka Hasumi
- School of Life Science and Technology, Tokyo Institute of Technology, S2-19, Nagatsuta 4259, Midori-ku, Yokohama, 226-8501, Japan
| | - Morio Ueyama
- Department of Neurology, Faculty of Medicine, Kindai University, Ohonohigashi 377-2, Osaka-Sayama, 589-8511, Japan
| | - Yoshitaka Nagai
- Department of Neurology, Faculty of Medicine, Kindai University, Ohonohigashi 377-2, Osaka-Sayama, 589-8511, Japan
| | - Hiroaki Imataka
- Graduate School of Engineering, University of Hyogo, Shosha, 2167, Himeji, Hyogo, 671-2280, Japan
| | - Hideki Taguchi
- School of Life Science and Technology, Tokyo Institute of Technology, S2-19, Nagatsuta 4259, Midori-ku, Yokohama, 226-8501, Japan.
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, S2-19, Nagatsuta 4259, Midori-ku, Yokohama, 226-8501, Japan.
| |
Collapse
|
9
|
Cristi AC, Rapuri S, Coyne AN. Nuclear pore complex and nucleocytoplasmic transport disruption in neurodegeneration. FEBS Lett 2023; 597:2546-2566. [PMID: 37657945 PMCID: PMC10612469 DOI: 10.1002/1873-3468.14729] [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: 06/25/2023] [Revised: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023]
Abstract
Nuclear pore complexes (NPCs) play a critical role in maintaining the equilibrium between the nucleus and cytoplasm, enabling bidirectional transport across the nuclear envelope, and are essential for proper nuclear organization and gene regulation. Perturbations in the regulatory mechanisms governing NPCs and nuclear envelope homeostasis have been implicated in the pathogenesis of several neurodegenerative diseases. The ESCRT-III pathway emerges as a critical player in the surveillance and preservation of well-assembled, functional NPCs, as well as nuclear envelope sealing. Recent studies have provided insights into the involvement of nuclear ESCRT-III in the selective reduction of specific nucleoporins associated with neurodegenerative pathologies. Thus, maintaining quality control of the nuclear envelope and NPCs represents a pivotal element in the pathological cascade leading to neurodegenerative diseases. This review describes the constituents of the nuclear-cytoplasmic transport machinery, encompassing the nuclear envelope, NPC, and ESCRT proteins, and how their structural and functional alterations contribute to the development of neurodegenerative diseases.
Collapse
Affiliation(s)
- América Chandía Cristi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| | - Sampath Rapuri
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| | - Alyssa N Coyne
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore MD 21205, USA
| |
Collapse
|
10
|
Morón-Oset J, Fischer LK, Carcolé M, Giblin A, Zhang P, Isaacs AM, Grönke S, Partridge L. Toxicity of C9orf72-associated dipeptide repeat peptides is modified by commonly used protein tags. Life Sci Alliance 2023; 6:e202201739. [PMID: 37308278 PMCID: PMC10262077 DOI: 10.26508/lsa.202201739] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/14/2023] Open
Abstract
Hexanucleotide repeat expansions in the C9orf72 gene are the most prevalent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Transcripts of the expansions are translated into toxic dipeptide repeat (DPR) proteins. Most preclinical studies in cell and animal models have used protein-tagged polyDPR constructs to investigate DPR toxicity but the effects of tags on DPR toxicity have not been systematically explored. Here, we used Drosophila to assess the influence of protein tags on DPR toxicity. Tagging of 36 but not 100 arginine-rich DPRs with mCherry increased toxicity, whereas adding mCherry or GFP to GA100 completely abolished toxicity. FLAG tagging also reduced GA100 toxicity but less than the longer fluorescent tags. Expression of untagged but not GFP- or mCherry-tagged GA100 caused DNA damage and increased p62 levels. Fluorescent tags also affected GA100 stability and degradation. In summary, protein tags affect DPR toxicity in a tag- and DPR-dependent manner, and GA toxicity might be underestimated in studies using tagged GA proteins. Thus, including untagged DPRs as controls is important when assessing DPR toxicity in preclinical models.
Collapse
Affiliation(s)
| | | | - Mireia Carcolé
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
| | - Ashling Giblin
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Pingze Zhang
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, UCL Queen Square Institute of Neurology, London, UK
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| |
Collapse
|
11
|
McGoldrick P, Robertson J. Unraveling the impact of disrupted nucleocytoplasmic transport systems in C9orf72-associated ALS. Front Cell Neurosci 2023; 17:1247297. [PMID: 37720544 PMCID: PMC10501458 DOI: 10.3389/fncel.2023.1247297] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 08/08/2023] [Indexed: 09/19/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two adult-onset neurodegenerative diseases that are part of a common disease spectrum due to clinical, genetic, and pathological overlap. A prominent genetic factor contributing to both diseases is a hexanucleotide repeat expansion in a non-coding region of the C9orf72 gene. This mutation in C9orf72 leads to nuclear depletion and cytoplasmic aggregation of Tar DNA-RNA binding protein 43 (TDP-43). TDP-43 pathology is characteristic of the majority of ALS cases, irrespective of disease causation, and is present in ~50% of FTD cases. Defects in nucleocytoplasmic transport involving the nuclear pore complex, the Ran-GTPase cycle, and nuclear transport factors have been linked with the mislocalization of TDP-43. Here, we will explore and discuss the implications of these system abnormalities of nucleocytoplasmic transport in C9orf72-ALS/FTD, as well as in other forms of familial and sporadic ALS.
Collapse
Affiliation(s)
- Philip McGoldrick
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Janice Robertson
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Ionescu A, Altman T, Perlson E. Looking for answers far away from the soma-the (un)known axonal functions of TDP-43, and their contribution to early NMJ disruption in ALS. Mol Neurodegener 2023; 18:35. [PMID: 37259156 DOI: 10.1186/s13024-023-00623-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 05/01/2023] [Indexed: 06/02/2023] Open
Abstract
Axon degeneration and Neuromuscular Junction (NMJ) disruption are key pathologies in the fatal neurodegenerative disease Amyotrophic Lateral Sclerosis (ALS). Despite accumulating evidence that axons and NMJs are impacted at a very early stage of the disease, current knowledge about the mechanisms leading to their degeneration remains elusive. Cytoplasmic mislocalization and accumulation of the protein TDP-43 are considered key pathological hallmarks of ALS, as they occur in ~ 97% of ALS patients, both sporadic and familial. Recent studies have identified pathological accumulation of TDP-43 in intramuscular nerves of muscle biopsies collected from pre-diagnosed, early symptomatic ALS patients. These findings suggest a gain of function for TDP-43 in axons, which might facilitate early NMJ disruption. In this review, we dissect the process leading to axonal TDP-43 accumulation and phosphorylation, discuss the known and hypothesized roles TDP-43 plays in healthy axons, and review possible mechanisms that connect TDP-43 pathology to the axon and NMJ degeneration in ALS.
Collapse
Affiliation(s)
- Ariel Ionescu
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Room 605, Ramat Aviv, 69978, Tel Aviv, Israel
| | - Topaz Altman
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Room 605, Ramat Aviv, 69978, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Room 605, Ramat Aviv, 69978, Tel Aviv, Israel.
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.
| |
Collapse
|
14
|
Regulating Phase Transition in Neurodegenerative Diseases by Nuclear Import Receptors. BIOLOGY 2022; 11:biology11071009. [PMID: 36101390 PMCID: PMC9311884 DOI: 10.3390/biology11071009] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 11/17/2022]
Abstract
RNA-binding proteins (RBPs) with a low-complexity prion-like domain (PLD) can undergo aberrant phase transitions and have been implicated in neurodegenerative diseases such as ALS and FTD. Several nuclear RBPs mislocalize to cytoplasmic inclusions in disease conditions. Impairment in nucleocytoplasmic transport is another major event observed in ageing and in neurodegenerative disorders. Nuclear import receptors (NIRs) regulate the nucleocytoplasmic transport of different RBPs bearing a nuclear localization signal by restoring their nuclear localization. NIRs can also specifically dissolve or prevent the aggregation and liquid–liquid phase separation of wild-type or disease-linked mutant RBPs, due to their chaperoning activity. This review focuses on the LLPS of intrinsically disordered proteins and the role of NIRs in regulating LLPS in neurodegeneration. This review also discusses the implication of NIRs as therapeutic agents in neurogenerative diseases.
Collapse
|
15
|
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: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [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.
Collapse
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.
| |
Collapse
|
16
|
C9orf72 Hexanucleotide Repeat Expansion-Related Neuropathology Is Attenuated by Nasal Rifampicin in Mice. Biomedicines 2022; 10:biomedicines10051080. [PMID: 35625816 PMCID: PMC9138602 DOI: 10.3390/biomedicines10051080] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/27/2022] [Accepted: 05/02/2022] [Indexed: 12/02/2022] Open
Abstract
The non-coding GGGGCC hexanucleotide repeat expansion (HRE) in C9orf72 gene is a dominant cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). This intronic mutation elicits the formation of nuclear and cytoplasmic inclusions containing RNA, RNA-binding proteins, and HRE-derived dipeptide repeat proteins (DPRs), leading to neurodegeneration via the gain-of-toxic function or loss-of-function of relevant proteins. Using C9-500 mice harboring ~500 repeats of the GGGGCC sequence in human C9orf72 gene, we investigated the effects of rifampicin against HRE-related pathological phenotypes. Rifampicin was administered intranasally to 4.5- to 5-month-old mice for 1 month, and their cognitive function and neuropathology were assessed by the Morris water maze test and immunohistochemical staining. Rifampicin treatment reduced the formation of RNA foci and cytoplasmic inclusions containing DPRs or phosphorylated TDP-43, and furthermore, the levels of phosphorylated double-strand RNA-dependent protein kinase (PKR) that regulates repeat-associated non-ATG (RAN) translation. Synapse loss in the hippocampus and neuronal loss and microglial activation in the prefrontal and motor cortices were also attenuated, and mouse memory was significantly improved. Our findings suggest a therapeutic potential of nasal rifampicin in the prevention of C9orf72-linked neurodegenerative disorders.
Collapse
|
17
|
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.
Collapse
|
18
|
Ramic M, Andrade NS, Rybin MJ, Esanov R, Wahlestedt C, Benatar M, Zeier Z. Epigenetic Small Molecules Rescue Nucleocytoplasmic Transport and DNA Damage Phenotypes in C9ORF72 ALS/FTD. Brain Sci 2021; 11:brainsci11111543. [PMID: 34827542 PMCID: PMC8616043 DOI: 10.3390/brainsci11111543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/11/2021] [Accepted: 11/18/2021] [Indexed: 01/04/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease with available treatments only marginally slowing progression or improving survival. A hexanucleotide repeat expansion mutation in the C9ORF72 gene is the most commonly known genetic cause of both sporadic and familial cases of ALS and frontotemporal dementia (FTD). The C9ORF72 expansion mutation produces five dipeptide repeat proteins (DPRs), and while the mechanistic determinants of DPR-mediated neurotoxicity remain incompletely understood, evidence suggests that disruption of nucleocytoplasmic transport and increased DNA damage contributes to pathology. Therefore, characterizing these disturbances and determining the relative contribution of different DPRs is needed to facilitate the development of novel therapeutics for C9ALS/FTD. To this end, we generated a series of nucleocytoplasmic transport “biosensors”, composed of the green fluorescent protein (GFP), fused to different classes of nuclear localization signals (NLSs) and nuclear export signals (NESs). Using these biosensors in conjunction with automated microscopy, we investigated the role of the three most neurotoxic DPRs (PR, GR, and GA) on seven nuclear import and two export pathways. In addition to other DPRs, we found that PR had pronounced inhibitory effects on the classical nuclear export pathway and several nuclear import pathways. To identify compounds capable of counteracting the effects of PR on nucleocytoplasmic transport, we developed a nucleocytoplasmic transport assay and screened several commercially available compound libraries, totaling 2714 compounds. In addition to restoring nucleocytoplasmic transport efficiencies, hits from the screen also counteract the cytotoxic effects of PR. Selected hits were subsequently tested for their ability to rescue another C9ALS/FTD phenotype—persistent DNA double strand breakage. Overall, we found that DPRs disrupt multiple nucleocytoplasmic transport pathways and we identified small molecules that counteract these effects—resulting in increased viability of PR-expressing cells and decreased DNA damage markers in patient-derived motor neurons. Several HDAC inhibitors were validated as hits, supporting previous studies that show that HDAC inhibitors confer therapeutic effects in neurodegenerative models.
Collapse
Affiliation(s)
- Melina Ramic
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
| | - Nadja S. Andrade
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
| | - Matthew J. Rybin
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
| | - Rustam Esanov
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
| | - Claes Wahlestedt
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
| | - Michael Benatar
- Department of Neurology, University of Miami Miller School of Medicine, 1120 NW 14th St., Miami, FL 33136, USA;
| | - Zane Zeier
- Center for Therapeutic Innovation, Department of Psychiatry & Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Ave, Miami, FL 33136, USA; (M.R.); (N.S.A.); (M.J.R.); (R.E.); (C.W.)
- Correspondence: ; Tel.: +1-305-243-1367
| |
Collapse
|
19
|
Vanneste J, Van Den Bosch L. The Role of Nucleocytoplasmic Transport Defects in Amyotrophic Lateral Sclerosis. Int J Mol Sci 2021; 22:12175. [PMID: 34830069 PMCID: PMC8620263 DOI: 10.3390/ijms222212175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/10/2021] [Accepted: 10/14/2021] [Indexed: 12/24/2022] Open
Abstract
There is ample evidence that nucleocytoplasmic-transport deficits could play an important role in the pathology of amyotrophic lateral sclerosis (ALS). However, the currently available data are often circumstantial and do not fully clarify the exact causal and temporal role of nucleocytoplasmic transport deficits in ALS patients. Gaining this knowledge will be of great significance in order to be able to target therapeutically nucleocytoplasmic transport and/or the proteins involved in this process. The availability of good model systems to study the nucleocytoplasmic transport process in detail will be especially crucial in investigating the effect of different mutations, as well as of other forms of stress. In this review, we discuss the evidence for the involvement of nucleocytoplasmic transport defects in ALS and the methods used to obtain these data. In addition, we provide an overview of the therapeutic strategies which could potentially counteract these defects.
Collapse
Affiliation(s)
- Joni Vanneste
- Experimental Neurology, Department of Neurosciences and Leuven Brain Institute (LBI), KU Leuven–University of Leuven, B-3000 Leuven, Belgium;
- Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, B-3000 Leuven, Belgium
| | - Ludo Van Den Bosch
- Experimental Neurology, Department of Neurosciences and Leuven Brain Institute (LBI), KU Leuven–University of Leuven, B-3000 Leuven, Belgium;
- Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, B-3000 Leuven, Belgium
| |
Collapse
|
20
|
Semmelink MFW, Steen A, Veenhoff LM. Measuring and Interpreting Nuclear Transport in Neurodegenerative Disease-The Example of C9orf72 ALS. Int J Mol Sci 2021; 22:9217. [PMID: 34502125 PMCID: PMC8431710 DOI: 10.3390/ijms22179217] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/13/2021] [Accepted: 08/18/2021] [Indexed: 11/25/2022] Open
Abstract
Transport from and into the nucleus is essential to all eukaryotic life and occurs through the nuclear pore complex (NPC). There are a multitude of data supporting a role for nuclear transport in neurodegenerative diseases, but actual transport assays in disease models have provided diverse outcomes. In this review, we summarize how nuclear transport works, which transport assays are available, and what matters complicate the interpretation of their results. Taking a specific type of ALS caused by mutations in C9orf72 as an example, we illustrate these complications, and discuss how the current data do not firmly answer whether the kinetics of nucleocytoplasmic transport are altered. Answering this open question has far-reaching implications, because a positive answer would imply that widespread mislocalization of proteins occurs, far beyond the reported mislocalization of transport reporters, and specific proteins such as FUS, or TDP43, and thus presents a challenge for future research.
Collapse
Affiliation(s)
| | | | - Liesbeth M. Veenhoff
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV Groningen, The Netherlands; (M.F.W.S.); (A.S.)
| |
Collapse
|
21
|
Frottin F, Pérez-Berlanga M, Hartl FU, Hipp MS. Multiple pathways of toxicity induced by C9orf72 dipeptide repeat aggregates and G 4C 2 RNA in a cellular model. eLife 2021; 10:62718. [PMID: 34161229 PMCID: PMC8221807 DOI: 10.7554/elife.62718] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 06/08/2021] [Indexed: 12/05/2022] Open
Abstract
The most frequent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia is a G4C2 repeat expansion in the C9orf72 gene. This expansion gives rise to translation of aggregating dipeptide repeat (DPR) proteins, including poly-GA as the most abundant species. However, gain of toxic function effects have been attributed to either the DPRs or the pathological G4C2 RNA. Here, we analyzed in a cellular model the relative toxicity of DPRs and RNA. Cytoplasmic poly-GA aggregates, generated in the absence of G4C2 RNA, interfered with nucleocytoplasmic protein transport, but had little effect on cell viability. In contrast, nuclear poly-GA was more toxic, impairing nucleolar protein quality control and protein biosynthesis. Production of the G4C2 RNA strongly reduced viability independent of DPR translation and caused pronounced inhibition of nuclear mRNA export and protein biogenesis. Thus, while the toxic effects of G4C2 RNA predominate in the cellular model used, DPRs exert additive effects that may contribute to pathology.
Collapse
Affiliation(s)
- Frédéric Frottin
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Manuela Pérez-Berlanga
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
| | - F Ulrich Hartl
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Mark S Hipp
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.,School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| |
Collapse
|
22
|
Cicardi ME, Marrone L, Azzouz M, Trotti D. Proteostatic imbalance and protein spreading in amyotrophic lateral sclerosis. EMBO J 2021; 40:e106389. [PMID: 33792056 PMCID: PMC8126909 DOI: 10.15252/embj.2020106389] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/18/2020] [Accepted: 02/25/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder whose exact causative mechanisms are still under intense investigation. Several lines of evidence suggest that the anatomical and temporal propagation of pathological protein species along the neural axis could be among the main driving mechanisms for the fast and irreversible progression of ALS pathology. Many ALS-associated proteins form intracellular aggregates as a result of their intrinsic prion-like properties and/or following impairment of the protein quality control systems. During the disease course, these mutated proteins and aberrant peptides are released in the extracellular milieu as soluble or aggregated forms through a variety of mechanisms. Internalization by recipient cells may seed further aggregation and amplify existing proteostatic imbalances, thus triggering a vicious cycle that propagates pathology in vulnerable cells, such as motor neurons and other susceptible neuronal subtypes. Here, we provide an in-depth review of ALS pathology with a particular focus on the disease mechanisms of seeding and transmission of the most common ALS-associated proteins, including SOD1, FUS, TDP-43, and C9orf72-linked dipeptide repeats. For each of these proteins, we report historical, biochemical, and pathological evidence of their behaviors in ALS. We further discuss the possibility to harness pathological proteins as biomarkers and reflect on the implications of these findings for future research.
Collapse
Affiliation(s)
- Maria Elena Cicardi
- Department of NeuroscienceWeinberg ALS CenterVickie and Jack Farber Institute for NeuroscienceThomas Jefferson UniversityPhiladelphiaPAUSA
| | - Lara Marrone
- Department of NeuroscienceSheffield Institute for Translational Neuroscience (SITraN)University of SheffieldSheffieldUK
| | - Mimoun Azzouz
- Department of NeuroscienceSheffield Institute for Translational Neuroscience (SITraN)University of SheffieldSheffieldUK
| | - Davide Trotti
- Department of NeuroscienceWeinberg ALS CenterVickie and Jack Farber Institute for NeuroscienceThomas Jefferson UniversityPhiladelphiaPAUSA
| |
Collapse
|
23
|
Solomon DA, Smikle R, Reid MJ, Mizielinska S. Altered Phase Separation and Cellular Impact in C9orf72-Linked ALS/FTD. Front Cell Neurosci 2021; 15:664151. [PMID: 33967699 PMCID: PMC8096919 DOI: 10.3389/fncel.2021.664151] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
Since the discovery of the C9orf72 repeat expansion mutation as causative for chromosome 9-linked amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) in 2011, a multitude of cellular pathways have been implicated. However, evidence has also been accumulating for a key mechanism of cellular compartmentalization—phase separation. Liquid-liquid phase separation (LLPS) is fundamental for the formation of membraneless organelles including stress granules, the nucleolus, Cajal bodies, nuclear speckles and the central channel of the nuclear pore. Evidence has now accumulated showing that the formation and function of these membraneless organelles is impaired by both the toxic arginine rich dipeptide repeat proteins (DPRs), translated from the C9orf72 repeat RNA transcript, and the repeat RNA itself. Both the arginine rich DPRs and repeat RNA themselves undergo phase separation and disrupt the physiological phase separation of proteins involved in the formation of these liquid-like organelles. Hence abnormal phase separation may explain a number of pathological cellular phenomena associated with C9orf72-ALS/FTD. In this review article, we will discuss the principles of phase separation, phase separation of the DPRs and repeat RNA themselves and how they perturb LLPS associated with membraneless organelles and the functional consequences of this. We will then discuss how phase separation may impact the major pathological feature of C9orf72-ALS/FTD, TDP-43 proteinopathy, and how LLPS may be targeted therapeutically in disease.
Collapse
Affiliation(s)
- Daniel A Solomon
- UK Dementia Research Institute at King's College London, London, United Kingdom.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Rebekah Smikle
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Matthew J Reid
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Sarah Mizielinska
- UK Dementia Research Institute at King's College London, London, United Kingdom.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| |
Collapse
|
24
|
Ding B, Sepehrimanesh M. Nucleocytoplasmic Transport: Regulatory Mechanisms and the Implications in Neurodegeneration. Int J Mol Sci 2021; 22:4165. [PMID: 33920577 PMCID: PMC8072611 DOI: 10.3390/ijms22084165] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
Nucleocytoplasmic transport (NCT) across the nuclear envelope is precisely regulated in eukaryotic cells, and it plays critical roles in maintenance of cellular homeostasis. Accumulating evidence has demonstrated that dysregulations of NCT are implicated in aging and age-related neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer's disease (AD), and Huntington disease (HD). This is an emerging research field. The molecular mechanisms underlying impaired NCT and the pathogenesis leading to neurodegeneration are not clear. In this review, we comprehensively described the components of NCT machinery, including nuclear envelope (NE), nuclear pore complex (NPC), importins and exportins, RanGTPase and its regulators, and the regulatory mechanisms of nuclear transport of both protein and transcript cargos. Additionally, we discussed the possible molecular mechanisms of impaired NCT underlying aging and neurodegenerative diseases, such as ALS/FTD, HD, and AD.
Collapse
Affiliation(s)
- Baojin Ding
- Department of Biology, University of Louisiana at Lafayette, 410 East Saint Mary Boulevard, Lafayette, LA 70503, USA;
| | | |
Collapse
|
25
|
Ghasemi M, Keyhanian K, Douthwright C. Glial Cell Dysfunction in C9orf72-Related Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Cells 2021; 10:cells10020249. [PMID: 33525344 PMCID: PMC7912327 DOI: 10.3390/cells10020249] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
Since the discovery of the chromosome 9 open reading frame 72 (C9orf72) repeat expansion mutation in 2011 as the most common genetic abnormality in amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig's disease) and frontotemporal dementia (FTD), progress in understanding the signaling pathways related to this mutation can only be described as intriguing. Two major theories have been suggested-(i) loss of function or haploinsufficiency and (ii) toxic gain of function from either C9orf72 repeat RNA or dipeptide repeat proteins (DPRs) generated from repeat-associated non-ATG (RAN) translation. Each theory has provided various signaling pathways that potentially participate in the disease progression. Dysregulation of the immune system, particularly glial cell dysfunction (mainly microglia and astrocytes), is demonstrated to play a pivotal role in both loss and gain of function theories of C9orf72 pathogenesis. In this review, we discuss the pathogenic roles of glial cells in C9orf72 ALS/FTD as evidenced by pre-clinical and clinical studies showing the presence of gliosis in C9orf72 ALS/FTD, pathologic hallmarks in glial cells, including TAR DNA-binding protein 43 (TDP-43) and p62 aggregates, and toxicity of C9orf72 glial cells. A better understanding of these pathways can provide new insights into the development of therapies targeting glial cell abnormalities in C9orf72 ALS/FTD.
Collapse
Affiliation(s)
- Mehdi Ghasemi
- Correspondence: ; Tel.: +1-774-441-7726; Fax: +1-508-856-4485
| | | | | |
Collapse
|
26
|
Hutten S, Usluer S, Bourgeois B, Simonetti F, Odeh HM, Fare CM, Czuppa M, Hruska-Plochan M, Hofweber M, Polymenidou M, Shorter J, Edbauer D, Madl T, Dormann D. Nuclear Import Receptors Directly Bind to Arginine-Rich Dipeptide Repeat Proteins and Suppress Their Pathological Interactions. Cell Rep 2020; 33:108538. [PMID: 33357437 PMCID: PMC7814465 DOI: 10.1016/j.celrep.2020.108538] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/06/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
Nuclear import receptors, also called importins, mediate nuclear import of proteins and chaperone aggregation-prone cargoes (e.g., neurodegeneration-linked RNA-binding proteins [RBPs]) in the cytoplasm. Importins were identified as modulators of cellular toxicity elicited by arginine-rich dipeptide repeat proteins (DPRs), an aberrant protein species found in C9orf72-linked amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Mechanistically, the link between importins and arginine-rich DPRs remains unclear. Here, we show that arginine-rich DPRs (poly-GR and poly-PR) bind directly to multiple importins and, in excess, promote their insolubility and condensation. In cells, poly-GR impairs Impα/β-mediated nuclear import, including import of TDP-43, an RBP that aggregates in C9orf72-ALS/FTD patients. Arginine-rich DPRs promote phase separation and insolubility of TDP-43 in vitro and in cells, and this pathological interaction is suppressed by elevating importin concentrations. Our findings suggest that importins can decrease toxicity of arginine-rich DPRs by suppressing their pathological interactions.
Collapse
Affiliation(s)
- Saskia Hutten
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany.
| | - Sinem Usluer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology & Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Benjamin Bourgeois
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology & Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Francesca Simonetti
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| | - Hana M Odeh
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Charlotte M Fare
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mareike Czuppa
- German Center for Neurodegenerative Diseases (DZNE), Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Marian Hruska-Plochan
- Department of Quantitative Biomedicine, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Mario Hofweber
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany; LMU Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany
| | - Magdalini Polymenidou
- Department of Quantitative Biomedicine, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - James Shorter
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany; LMU Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology & Biochemistry, Medical University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria
| | - Dorothee Dormann
- BioMedical Center (BMC), Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany; LMU Graduate School of Systemic Neurosciences (GSN), 82152 Planegg-Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany.
| |
Collapse
|
27
|
Rostalski H, Hietanen T, Leskelä S, Behánová A, Abdollahzadeh A, Wittrahm R, Mäkinen P, Huber N, Hoffmann D, Solje E, Remes AM, Natunen T, Takalo M, Tohka J, Hiltunen M, Haapasalo A. BV-2 Microglial Cells Overexpressing C9orf72 Hexanucleotide Repeat Expansion Produce DPR Proteins and Show Normal Functionality but No RNA Foci. Front Neurol 2020; 11:550140. [PMID: 33123074 PMCID: PMC7573144 DOI: 10.3389/fneur.2020.550140] [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: 04/11/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022] Open
Abstract
Hexanucleotide repeat expansion (HRE) in the chromosome 9 open-reading frame 72 (C9orf72) gene is the most common genetic cause underpinning frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). It leads to the accumulation of toxic RNA foci and various dipeptide repeat (DPR) proteins into cells. These C9orf72 HRE-specific hallmarks are abundant in neurons. So far, the role of microglia, the immune cells of the brain, in C9orf72 HRE-associated FTLD/ALS is unclear. In this study, we overexpressed C9orf72 HRE of a pathological length in the BV-2 microglial cell line and used biochemical methods and fluorescence imaging to investigate its effects on their phenotype, viability, and functionality. We found that BV-2 cells expressing the C9orf72 HRE presented strong expression of specific DPR proteins but no sense RNA foci. Transiently increased levels of cytoplasmic TAR DNA-binding protein 43 (TDP-43), slightly altered levels of p62 and lysosome-associated membrane protein (LAMP) 2A, and reduced levels of polyubiquitinylated proteins, but no signs of cell death were detected in HRE overexpressing cells. Overexpression of the C9orf72 HRE did not affect BV-2 cell phagocytic activity or response to an inflammatory stimulus, nor did it shift their RNA profile toward disease-associated microglia. These findings suggest that DPR proteins do not affect microglial cell viability or functionality in BV-2 cells. However, additional studies in other models are required to further elucidate the role of C9orf72 HRE in microglia.
Collapse
Affiliation(s)
- Hannah Rostalski
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Tomi Hietanen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Stina Leskelä
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Andrea Behánová
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Ali Abdollahzadeh
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Rebekka Wittrahm
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Petra Mäkinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Nadine Huber
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Dorit Hoffmann
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Eino Solje
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Neuro Center, Neurology, Kuopio University Hospital, Kuopio, Finland
| | - Anne M Remes
- Unit of Clinical Neuroscience, Neurology, University of Oulu, Oulu, Finland.,Medical Research Center (MRC) Oulu, Oulu University Hospital, Oulu, Finland
| | - Teemu Natunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Mari Takalo
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Jussi Tohka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mikko Hiltunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Annakaisa Haapasalo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
28
|
West RJH, Sharpe JL, Voelzmann A, Munro AL, Hahn I, Baines RA, Pickering-Brown S. Co-expression of C9orf72 related dipeptide-repeats over 1000 repeat units reveals age- and combination-specific phenotypic profiles in Drosophila. Acta Neuropathol Commun 2020; 8:158. [PMID: 32894207 PMCID: PMC7487709 DOI: 10.1186/s40478-020-01028-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 02/08/2023] Open
Abstract
A large intronic hexanucleotide repeat expansion (GGGGCC) within the C9orf72 (C9orf72-SMCR8 Complex Subunit) locus is the most prevalent genetic cause of both Frontotemporal Dementia (FTD) and Motor Neuron Disease (MND). In patients this expansion is typically hundreds to thousands of repeat units in length. Repeat associated non-AUG translation of the expansion leads to the formation of toxic, pathological Dipeptide-Repeat Proteins (DPRs). To date there remains a lack of in vivo models expressing C9orf72 related DPRs with a repeat length of more than a few hundred repeats. As such our understanding of how physiologically relevant repeat length DPRs effect the nervous system in an ageing in vivo system remains limited. In this study we generated Drosophila models expressing DPRs over 1000 repeat units in length, a known pathological length in humans. Using these models, we demonstrate each DPR exhibits a unique, age-dependent, phenotypic and pathological profile. Furthermore, we show co-expression of specific DPR combinations leads to distinct, age-dependent, phenotypes not observed through expression of single DPRs. We propose these models represent a unique, in vivo, tool for dissecting the molecular mechanisms implicated in disease pathology, opening up new avenues in the study of both MND and FTD.
Collapse
Affiliation(s)
- Ryan J. H. West
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, 385 Glossop Road, Sheffield, S10 2HQ UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN UK
| | - Joanne L. Sharpe
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - André Voelzmann
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Anna L. Munro
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Ines Hahn
- Division of Molecular and Cellular Function, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Richard A. Baines
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Stuart Pickering-Brown
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| |
Collapse
|
29
|
Le Gall L, Anakor E, Connolly O, Vijayakumar UG, Duddy WJ, Duguez S. Molecular and Cellular Mechanisms Affected in ALS. J Pers Med 2020; 10:E101. [PMID: 32854276 PMCID: PMC7564998 DOI: 10.3390/jpm10030101] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/17/2020] [Accepted: 08/22/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a terminal late-onset condition characterized by the loss of upper and lower motor neurons. Mutations in more than 30 genes are associated to the disease, but these explain only ~20% of cases. The molecular functions of these genes implicate a wide range of cellular processes in ALS pathology, a cohesive understanding of which may provide clues to common molecular mechanisms across both familial (inherited) and sporadic cases and could be key to the development of effective therapeutic approaches. Here, the different pathways that have been investigated in ALS are summarized, discussing in detail: mitochondrial dysfunction, oxidative stress, axonal transport dysregulation, glutamate excitotoxicity, endosomal and vesicular transport impairment, impaired protein homeostasis, and aberrant RNA metabolism. This review considers the mechanistic roles of ALS-associated genes in pathology, viewed through the prism of shared molecular pathways.
Collapse
Affiliation(s)
- Laura Le Gall
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
- NIHR Biomedical Research Centre, University College London, Great Ormond Street Institute of Child Health and Great Ormond Street Hospital NHS Trust, London WC1N 1EH, UK
| | - Ekene Anakor
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
| | - Owen Connolly
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
| | - Udaya Geetha Vijayakumar
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
| | - William J. Duddy
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
| | - Stephanie Duguez
- Northern Ireland Center for Stratified/Personalised Medicine, Biomedical Sciences Research Institute, Ulster University, Derry-Londonderry BT47, UK; (L.L.G.); (E.A.); (O.C.); (U.G.V.); (W.J.D.)
| |
Collapse
|
30
|
Jafarinia H, van der Giessen E, Onck PR. Phase Separation of Toxic Dipeptide Repeat Proteins Related to C9orf72 ALS/FTD. Biophys J 2020; 119:843-851. [PMID: 32730793 DOI: 10.1016/j.bpj.2020.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/28/2020] [Accepted: 07/06/2020] [Indexed: 10/23/2022] Open
Abstract
The expansion mutation in the C9orf72 gene is the most common known genetic cause for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). This mutation can produce five dipeptide repeat proteins (DPRs), of which three are known to be toxic: poly-PR, poly-GR, and poly-GA. The toxicity of poly-GA is attributed to its aggregation in the cytoplasm, whereas for poly-PR and poly-GR, several toxicity pathways have been proposed. The toxicity of the DPRs has been shown to depend on their length, but the underlying molecular mechanism of this length dependence is not well understood. To address the possible role of phase separation in DPR toxicity, a one-bead-per-amino-acid (1BPA) coarse-grained molecular dynamics model is used to study the single-molecule and phase-separation properties of the DPRs. We find a strong dependence of the phase-separation behavior on both DPR length and concentration, with longer DPRs having a higher propensity to phase separate and form condensed phases with higher concentrations. The critical lengths required for phase separation (25 for poly-PR and 50 for poly-GA) are comparable to the toxicity threshold limit of 30 repeats found for the expansion mutation in patient cells, suggesting that phase separation could play an important role in DPR toxicity.
Collapse
Affiliation(s)
- Hamidreza Jafarinia
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands
| | - Erik van der Giessen
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands
| | - Patrick R Onck
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands.
| |
Collapse
|
31
|
Khosravi B, LaClair KD, Riemenschneider H, Zhou Q, Frottin F, Mareljic N, Czuppa M, Farny D, Hartmann H, Michaelsen M, Arzberger T, Hartl FU, Hipp MS, Edbauer D. Cell-to-cell transmission of C9orf72 poly-(Gly-Ala) triggers key features of ALS/FTD. EMBO J 2020; 39:e102811. [PMID: 32175624 PMCID: PMC7156967 DOI: 10.15252/embj.2019102811] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/13/2022] Open
Abstract
The C9orf72 repeat expansion causes amyotrophic lateral sclerosis and frontotemporal dementia, but the poor correlation between C9orf72‐specific pathology and TDP‐43 pathology linked to neurodegeneration hinders targeted therapeutic development. Here, we addressed the role of the aggregating dipeptide repeat proteins resulting from unconventional translation of the repeat in all reading frames. Poly‐GA promoted cytoplasmic mislocalization and aggregation of TDP‐43 non‐cell‐autonomously, and anti‐GA antibodies ameliorated TDP‐43 mislocalization in both donor and receiver cells. Cell‐to‐cell transmission of poly‐GA inhibited proteasome function in neighboring cells. Importantly, proteasome inhibition led to the accumulation of TDP‐43 ubiquitinated within the nuclear localization signal (NLS) at lysine 95. Mutagenesis of this ubiquitination site completely blocked poly‐GA‐dependent mislocalization of TDP‐43. Boosting proteasome function with rolipram reduced both poly‐GA and TDP‐43 aggregation. Our data from cell lines, primary neurons, transgenic mice, and patient tissue suggest that poly‐GA promotes TDP‐43 aggregation by inhibiting the proteasome cell‐autonomously and non‐cell‐autonomously, which can be prevented by inhibiting poly‐GA transmission with antibodies or boosting proteasome activity with rolipram.
Collapse
Affiliation(s)
- Bahram Khosravi
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximilians-University Munich, Munich, Germany
| | | | | | - Qihui Zhou
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Frédéric Frottin
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Nikola Mareljic
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Mareike Czuppa
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Daniel Farny
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | | | - Meike Michaelsen
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Thomas Arzberger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany.,Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Mark S Hipp
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Department of Biomedical Sciences of Cells and Systems, University of Groningen, Groningen, The Netherlands.,School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximilians-University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
32
|
Fallini C, Khalil B, Smith CL, Rossoll W. Traffic jam at the nuclear pore: All roads lead to nucleocytoplasmic transport defects in ALS/FTD. Neurobiol Dis 2020; 140:104835. [PMID: 32179176 DOI: 10.1016/j.nbd.2020.104835] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/25/2020] [Accepted: 03/12/2020] [Indexed: 02/06/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal late-onset neurodegenerative disease that specifically affects the function and survival of spinal and cortical motor neurons. ALS shares many genetic, clinical, and pathological characteristics with frontotemporal dementia (FTD), and these diseases are now recognized as presentations of a disease spectrum known as ALS/FTD. The molecular determinants of neuronal loss in ALS/FTD are still debated, but the recent discovery of nucleocytoplasmic transport defects as a common denominator of most if not all forms of ALS/FTD has dramatically changed our understanding of the pathogenic mechanisms of this disease. Loss of nuclear pores and nucleoporin aggregation, altered nuclear morphology, and impaired nuclear transport are some of the most prominent features that have been identified using a variety of animal, cellular, and human models of disease. Here, we review the experimental evidence linking nucleocytoplasmic transport defects to the pathogenesis of ALS/FTD and propose a unifying view on how these defects may lead to a vicious cycle that eventually causes neuronal death.
Collapse
Affiliation(s)
- Claudia Fallini
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA; Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA; Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA.
| | - Bilal Khalil
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Courtney L Smith
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Wilfried Rossoll
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
| |
Collapse
|
33
|
Hayes LR, Duan L, Bowen K, Kalab P, Rothstein JD. C9orf72 arginine-rich dipeptide repeat proteins disrupt karyopherin-mediated nuclear import. eLife 2020; 9:e51685. [PMID: 32119645 PMCID: PMC7051184 DOI: 10.7554/elife.51685] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/17/2020] [Indexed: 12/13/2022] Open
Abstract
Disruption of nucleocytoplasmic transport is increasingly implicated in the pathogenesis of neurodegenerative diseases, including ALS caused by a C9orf72 hexanucleotide repeat expansion. However, the mechanism(s) remain unclear. Karyopherins, including importin β and its cargo adaptors, have been shown to co-precipitate with the C9orf72 arginine-containing dipeptide repeat proteins (R-DPRs), poly-glycine arginine (GR) and poly-proline arginine (PR), and are protective in genetic modifier screens. Here, we show that R-DPRs interact with importin β, disrupt its cargo loading, and inhibit nuclear import of importin β, importin α/β, and transportin cargoes in permeabilized mouse neurons and HeLa cells, in a manner that can be rescued by RNA. Although R-DPRs induce widespread protein aggregation in this in vitro system, transport disruption is not due to nucleocytoplasmic transport protein sequestration, nor blockade of the phenylalanine-glycine (FG)-rich nuclear pore complex. Our results support a model in which R-DPRs interfere with cargo loading on karyopherins.
Collapse
Affiliation(s)
- Lindsey R Hayes
- Department of Neurology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Brain Science Institute, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Lauren Duan
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins UniversityBaltimoreUnited States
| | - Kelly Bowen
- Department of Neurology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Brain Science Institute, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Petr Kalab
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins UniversityBaltimoreUnited States
| | - Jeffrey D Rothstein
- Department of Neurology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Brain Science Institute, Johns Hopkins University School of MedicineBaltimoreUnited States
| |
Collapse
|
34
|
Zhou Q, Mareljic N, Michaelsen M, Parhizkar S, Heindl S, Nuscher B, Farny D, Czuppa M, Schludi C, Graf A, Krebs S, Blum H, Feederle R, Roth S, Haass C, Arzberger T, Liesz A, Edbauer D. Active poly-GA vaccination prevents microglia activation and motor deficits in a C9orf72 mouse model. EMBO Mol Med 2020; 12:e10919. [PMID: 31858749 PMCID: PMC7005532 DOI: 10.15252/emmm.201910919] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/29/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022] Open
Abstract
The C9orf72 repeat expansion is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and/or frontotemporal dementia (FTD). Non-canonical translation of the expanded repeat results in abundant poly-GA inclusion pathology throughout the CNS. (GA)149 -CFP expression in mice triggers motor deficits and neuroinflammation. Since poly-GA is transmitted between cells, we investigated the therapeutic potential of anti-GA antibodies by vaccinating (GA)149 -CFP mice. To overcome poor immunogenicity, we compared the antibody response of multivalent ovalbumin-(GA)10 conjugates and pre-aggregated carrier-free (GA)15 . Only ovalbumin-(GA)10 immunization induced a strong anti-GA response. The resulting antisera detected poly-GA aggregates in cell culture and patient tissue. Ovalbumin-(GA)10 immunization largely rescued the motor function in (GA)149 -CFP transgenic mice and reduced poly-GA inclusions. Transcriptome analysis showed less neuroinflammation in ovalbumin-(GA)10 -immunized poly-GA mice, which was corroborated by semiquantitative and morphological analysis of microglia/macrophages. Moreover, cytoplasmic TDP-43 mislocalization and levels of the neurofilament light chain in the CSF were reduced, suggesting neuroaxonal damage is reduced. Our data suggest that immunotherapy may be a viable primary prevention strategy for ALS/FTD in C9orf72 mutation carriers.
Collapse
Affiliation(s)
- Qihui Zhou
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
| | - Nikola Mareljic
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
| | - Meike Michaelsen
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
| | - Samira Parhizkar
- Chair of Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MunichMunichGermany
| | - Steffanie Heindl
- Institute for Stroke and Dementia ResearchLudwig‐Maximilians‐University MunichMunichGermany
| | - Brigitte Nuscher
- Chair of Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MunichMunichGermany
| | - Daniel Farny
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
| | - Mareike Czuppa
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
| | - Carina Schludi
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
| | - Alexander Graf
- Laboratory for Functional Genome AnalysisGene CenterLudwig Maximilian University of MunichMunichGermany
| | - Stefan Krebs
- Laboratory for Functional Genome AnalysisGene CenterLudwig Maximilian University of MunichMunichGermany
| | - Helmut Blum
- Laboratory for Functional Genome AnalysisGene CenterLudwig Maximilian University of MunichMunichGermany
| | - Regina Feederle
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Monoclonal Antibody Core Facility and Research GroupInstitute for Diabetes and ObesityHelmholtz Zentrum MünchenGerman Research Center for Environmental Health (GmbH)MunichGermany
| | - Stefan Roth
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Institute for Stroke and Dementia ResearchLudwig‐Maximilians‐University MunichMunichGermany
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Chair of Metabolic BiochemistryBiomedical Center (BMC)Faculty of MedicineLudwig‐Maximilians‐Universität MunichMunichGermany
| | - Thomas Arzberger
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Center for Neuropathology and Prion ResearchLudwig‐Maximilians‐University MunichMunichGermany
- Department of Psychiatry and PsychotherapyUniversity HospitalLudwig‐Maximilians‐University MunichMunichGermany
| | - Arthur Liesz
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Institute for Stroke and Dementia ResearchLudwig‐Maximilians‐University MunichMunichGermany
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), MunichMunichGermany
- Munich Cluster of Systems Neurology (SyNergy)MunichGermany
- Ludwig‐Maximilians‐University MunichMunichGermany
| |
Collapse
|
35
|
Boivin M, Pfister V, Gaucherot A, Ruffenach F, Negroni L, Sellier C, Charlet-Berguerand N. Reduced autophagy upon C9ORF72 loss synergizes with dipeptide repeat protein toxicity in G4C2 repeat expansion disorders. EMBO J 2020; 39:e100574. [PMID: 31930538 PMCID: PMC7024836 DOI: 10.15252/embj.2018100574] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 11/28/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022] Open
Abstract
Expansion of G4C2 repeats within the C9ORF72 gene is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Such repeats lead to decreased expression of the autophagy regulator C9ORF72 protein. Furthermore, sense and antisense repeats are translated into toxic dipeptide repeat (DPR) proteins. It is unclear how these repeats are translated, and in which way their translation and the reduced expression of C9ORF72 modulate repeat toxicity. Here, we found that sense and antisense repeats are translated upon initiation at canonical AUG or near‐cognate start codons, resulting in polyGA‐, polyPG‐, and to a lesser degree polyGR‐DPR proteins. However, accumulation of these proteins is prevented by autophagy. Importantly, reduced C9ORF72 levels lead to suboptimal autophagy, thereby impairing clearance of DPR proteins and causing their toxic accumulation, ultimately resulting in neuronal cell death. Of clinical importance, pharmacological compounds activating autophagy can prevent neuronal cell death caused by DPR proteins accumulation. These results suggest the existence of a double‐hit pathogenic mechanism in ALS/FTD, whereby reduced expression of C9ORF72 synergizes with DPR protein accumulation and toxicity.
Collapse
Affiliation(s)
- Manon Boivin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Véronique Pfister
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Angeline Gaucherot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Frank Ruffenach
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Luc Negroni
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| | - Nicolas Charlet-Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France
| |
Collapse
|
36
|
Nihei Y, Mori K, Werner G, Arzberger T, Zhou Q, Khosravi B, Japtok J, Hermann A, Sommacal A, Weber M, Kamp F, Nuscher B, Edbauer D, Haass C. Poly-glycine-alanine exacerbates C9orf72 repeat expansion-mediated DNA damage via sequestration of phosphorylated ATM and loss of nuclear hnRNPA3. Acta Neuropathol 2020; 139:99-118. [PMID: 31642962 PMCID: PMC6942035 DOI: 10.1007/s00401-019-02082-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/30/2019] [Accepted: 10/01/2019] [Indexed: 12/13/2022]
Abstract
Repeat expansion in C9orf72 causes amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Expanded sense and antisense repeat RNA transcripts in C9orf72 are translated into five dipeptide-repeat proteins (DPRs) in an AUG-independent manner. We previously identified the heterogeneous ribonucleoprotein (hnRNP) A3 as an interactor of the sense repeat RNA that reduces its translation into DPRs. Furthermore, we found that hnRNPA3 is depleted from the nucleus and partially mislocalized to cytoplasmic poly-GA inclusions in C9orf72 patients, suggesting that poly-GA sequesters hnRNPA3 within the cytoplasm. We now demonstrate that hnRNPA3 also binds to the antisense repeat RNA. Both DPR production and deposition from sense and antisense RNA repeats are increased upon hnRNPA3 reduction. All DPRs induced DNA double strand breaks (DSB), which was further enhanced upon reduction of hnRNPA3. Poly-glycine–arginine and poly-proline-arginine increased foci formed by phosphorylated Ataxia Telangiectasia Mutated (pATM), a major sensor of DSBs, whereas poly-glycine–alanine (poly-GA) evoked a reduction of pATM foci. In dentate gyri of C9orf72 patients, lower nuclear hnRNPA3 levels were associated with increased DNA damage. Moreover, enhanced poly-GA deposition correlated with reduced pATM foci. Since cytoplasmic pATM deposits partially colocalized with poly-GA deposits, these results suggest that poly-GA, the most frequent DPR observed in C9orf72 patients, differentially causes DNA damage and that poly-GA selectively sequesters pATM in the cytoplasm inhibiting its recruitment to sites of DNA damage. Thus, mislocalization of nuclear hnRNPA3 caused by poly-GA leads to increased poly-GA production, which partially depletes pATM, and consequently enhances DSB.
Collapse
|
37
|
Congenic expression of poly-GA but not poly-PR in mice triggers selective neuron loss and interferon responses found in C9orf72 ALS. Acta Neuropathol 2020; 140:121-142. [PMID: 32562018 PMCID: PMC7360660 DOI: 10.1007/s00401-020-02176-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022]
Abstract
Expansion of a (G4C2)n repeat in C9orf72 causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but the link of the five repeat-encoded dipeptide repeat (DPR) proteins to neuroinflammation, TDP-43 pathology, and neurodegeneration is unclear. Poly-PR is most toxic in vitro, but poly-GA is far more abundant in patients. To directly compare these in vivo, we created congenic poly-GA and poly-PR mice. 40% of poly-PR mice were affected with ataxia and seizures, requiring euthanasia by 6 weeks of age. The remaining poly-PR mice were asymptomatic at 14 months of age, likely due to an 80% reduction of the transgene mRNA in this subgroup. In contrast, all poly-GA mice showed selective neuron loss, inflammation, as well as muscle denervation and wasting requiring euthanasia before 7 weeks of age. In-depth analysis of peripheral organs and blood samples suggests that peripheral organ failure does not drive these phenotypes. Although transgene mRNA levels were similar between poly-GA and affected poly-PR mice, poly-GA aggregated far more abundantly than poly-PR in the CNS and was also found in skeletal muscle. In addition, TDP-43 and other disease-linked RNA-binding proteins co-aggregated in rare nuclear inclusions in the hippocampus and frontal cortex only in poly-GA mice. Transcriptome analysis revealed activation of an interferon-responsive pro-inflammatory microglial signature in end-stage poly-GA but not poly-PR mice. This signature was also found in all ALS patients and enriched in C9orf72 cases. In summary, our rigorous comparison of poly-GA and poly-PR toxicity in vivo indicates that poly-GA, but not poly-PR at the same mRNA expression level, promotes interferon responses in C9orf72 disease and contributes to TDP-43 abnormalities and neuron loss selectively in disease-relevant regions.
Collapse
|
38
|
Morón-Oset J, Supèr T, Esser J, Isaacs AM, Grönke S, Partridge L. Glycine-alanine dipeptide repeats spread rapidly in a repeat length- and age-dependent manner in the fly brain. Acta Neuropathol Commun 2019; 7:209. [PMID: 31843021 PMCID: PMC6916080 DOI: 10.1186/s40478-019-0860-x] [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] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/02/2019] [Indexed: 12/12/2022] Open
Abstract
Hexanucleotide repeat expansions of variable size in C9orf72 are the most prevalent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Sense and antisense transcripts of the expansions are translated by repeat-associated non-AUG translation into five dipeptide repeat proteins (DPRs). Of these, the polyGR, polyPR and, to a lesser extent, polyGA DPRs are neurotoxic, with polyGA the most abundantly detected DPR in patient tissue. Trans-cellular transmission of protein aggregates has recently emerged as a major driver of toxicity in various neurodegenerative diseases. In vitro evidence suggests that the C9 DPRs can spread. However, whether this phenomenon occurs under more complex in vivo conditions remains unexplored. Here, we used the adult fly brain to investigate whether the C9 DPRs can spread in vivo upon expression in a subset of neurons. We found that only polyGA can progressively spread throughout the brain, which accumulates in the shape of aggregate-like puncta inside recipient cells. Interestingly, GA transmission occurred as early as 3 days after expression induction. By comparing the spread of 36, 100 and 200 polyGA repeats, we found that polyGA spread is enhanced upon expression of longer GA DPRs. Transmission of polyGA is greater in older flies, indicating that age-associated factors exacerbate the spread. These data highlight a unique propensity of polyGA to spread throughout the brain, which could contribute to the greater abundance of polyGA in patient tissue. In addition, we present a model of early GA transmission that is suitable for genetic screens to identify mechanisms of spread and its consequences in vivo.
Collapse
|
39
|
Nguyen L, Montrasio F, Pattamatta A, Tusi SK, Bardhi O, Meyer KD, Hayes L, Nakamura K, Banez-Coronel M, Coyne A, Guo S, Laboissonniere LA, Gu Y, Narayanan S, Smith B, Nitsch RM, Kankel MW, Rushe M, Rothstein J, Zu T, Grimm J, Ranum LPW. Antibody Therapy Targeting RAN Proteins Rescues C9 ALS/FTD Phenotypes in C9orf72 Mouse Model. Neuron 2019; 105:645-662.e11. [PMID: 31831332 DOI: 10.1016/j.neuron.2019.11.007] [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: 07/16/2019] [Revised: 10/10/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
The intronic C9orf72 G4C2 expansion, the most common genetic cause of ALS and FTD, produces sense- and antisense-expansion RNAs and six dipeptide repeat-associated, non-ATG (RAN) proteins, but their roles in disease are unclear. We generated high-affinity human antibodies targeting GA or GP RAN proteins. These antibodies cross the blood-brain barrier and co-localize with intracellular RAN aggregates in C9-ALS/FTD BAC mice. In cells, α-GA1 interacts with TRIM21, and α-GA1 treatment reduced GA levels, increased GA turnover, and decreased RAN toxicity and co-aggregation of proteasome and autophagy proteins to GA aggregates. In C9-BAC mice, α-GA1 reduced GA as well as GP and GR proteins, improved behavioral deficits, decreased neuroinflammation and neurodegeneration, and increased survival. Glycosylation of the Fc region of α-GA1 is important for cell entry and efficacy. These data demonstrate that RAN proteins drive C9-ALS/FTD in C9-BAC transgenic mice and establish a novel therapeutic approach for C9orf72 ALS/FTD and other RAN-protein diseases.
Collapse
Affiliation(s)
- Lien Nguyen
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | | | - Amrutha Pattamatta
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Solaleh Khoramian Tusi
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Olgert Bardhi
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Kevin D Meyer
- Neurimmune AG, 8952 Schlieren, Switzerland; Institute for Regenerative Medicine-IREM, University of Zurich, 8952 Schlieren, Switzerland
| | - Lindsey Hayes
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Katsuya Nakamura
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Monica Banez-Coronel
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Alyssa Coyne
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Shu Guo
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Lauren A Laboissonniere
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Yuanzheng Gu
- Neuromuscular and Movement Disorders, Biogen, Cambridge, MA 02142, USA
| | | | - Benjamin Smith
- Neuromuscular and Movement Disorders, Biogen, Cambridge, MA 02142, USA
| | - Roger M Nitsch
- Neurimmune AG, 8952 Schlieren, Switzerland; Institute for Regenerative Medicine-IREM, University of Zurich, 8952 Schlieren, Switzerland
| | - Mark W Kankel
- Neuromuscular and Movement Disorders, Biogen, Cambridge, MA 02142, USA
| | - Mia Rushe
- Neuromuscular and Movement Disorders, Biogen, Cambridge, MA 02142, USA
| | - Jeffrey Rothstein
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Tao Zu
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA
| | - Jan Grimm
- Neurimmune AG, 8952 Schlieren, Switzerland
| | - Laura P W Ranum
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32610, USA.
| |
Collapse
|
40
|
Vanneste J, Vercruysse T, Boeynaems S, Sicart A, Van Damme P, Daelemans D, Van Den Bosch L. C9orf72-generated poly-GR and poly-PR do not directly interfere with nucleocytoplasmic transport. Sci Rep 2019; 9:15728. [PMID: 31673013 PMCID: PMC6823349 DOI: 10.1038/s41598-019-52035-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/11/2019] [Indexed: 12/29/2022] Open
Abstract
Repeat expansions in the C9orf72 gene cause amyotrophic lateral sclerosis and frontotemporal dementia characterized by dipeptide-repeat protein (DPR) inclusions. The toxicity associated with two of these DPRs, poly-GR and poly-PR, has been associated with nucleocytoplasmic transport. To investigate the causal role of poly-GR or poly-PR on active nucleocytoplasmic transport, we measured nuclear import and export in poly-GR or poly-PR expressing Hela cells, neuronal-like SH-SY5Y cells and iPSC-derived motor neurons. Our data strongly indicate that poly-GR and poly-PR do not directly impede active nucleocytoplasmic transport.
Collapse
Affiliation(s)
- Joni Vanneste
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Thomas Vercruysse
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Leuven, Belgium
| | - Steven Boeynaems
- Department of Genetics, Stanford University School of Medicine, Stanford, USA
| | - Adria Sicart
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Philip Van Damme
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
- University Hospitals Leuven, Department of Neurology, Leuven, Belgium
| | - Dirk Daelemans
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Leuven, Belgium
| | - Ludo Van Den Bosch
- KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium.
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
| |
Collapse
|
41
|
TDP-43 regulates transcription at protein-coding genes and Alu retrotransposons. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194434. [PMID: 31655156 DOI: 10.1016/j.bbagrm.2019.194434] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 12/13/2022]
Abstract
The 43-kDa transactive response DNA-binding protein (TDP-43) is an example of an RNA-binding protein that regulates RNA metabolism at multiple levels from transcription and splicing to translation. Its role in post-transcriptional RNA processing has been a primary focus of recent research, but its role in regulating transcription has been studied for only a few human genes. We characterized the effects of TDP-43 on transcription genome-wide and found that TDP-43 broadly affects transcription of protein-coding and noncoding RNA genes. Among protein-coding genes, the effects of TDP-43 were greatest for genes <30 thousand base pairs in length. Surprisingly, we found that the loss of TDP-43 resulted in increased evidence for transcription activity near repetitive Alu elements found within expressed genes. The highest densities of affected Alu elements were found in the shorter genes, whose transcription was most affected by TDP-43. Thus, in addition to its role in post-transcriptional RNA processing, TDP-43 plays a critical role in maintaining the transcriptional stability of protein-coding genes and transposable DNA elements.
Collapse
|
42
|
Lee SM, Asress S, Hales CM, Gearing M, Vizcarra JC, Fournier CN, Gutman DA, Chin LS, Li L, Glass JD. TDP-43 cytoplasmic inclusion formation is disrupted in C9orf72-associated amyotrophic lateral sclerosis/frontotemporal lobar degeneration. Brain Commun 2019; 1:fcz014. [PMID: 31633109 PMCID: PMC6788139 DOI: 10.1093/braincomms/fcz014] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/10/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
The G4C2 hexanucleotide repeat expansion mutation in the C9orf72 gene is the most common genetic cause underlying both amyotrophic lateral sclerosis and frontotemporal dementia. Pathologically, these two neurodegenerative disorders are linked by the common presence of abnormal phosphorylated TDP-43 neuronal cytoplasmic inclusions. We compared the number and size of phosphorylated TDP-43 inclusions and their morphology in hippocampi from patients dying with sporadic versus C9orf72-related amyotrophic lateral sclerosis with pathologically defined frontotemporal lobar degeneration with phosphorylated TDP-43 inclusions, the pathological substrate of clinical frontotemporal dementia in patients with amyotrophic lateral sclerosis. In sporadic cases, there were numerous consolidated phosphorylated TDP-43 inclusions that were variable in size, whereas inclusions in C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration were quantitatively smaller than those in sporadic cases. Also, C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration homogenized brain contained soluble cytoplasmic TDP-43 that was largely absent in sporadic cases. To better understand these pathological differences, we modelled TDP-43 inclusion formation in fibroblasts derived from sporadic or C9orf72-related amyotrophic lateral sclerosis/frontotemporal dementia patients. We found that both sporadic and C9orf72 amyotrophic lateral sclerosis/frontotemporal dementia patient fibroblasts showed impairment in TDP-43 degradation by the proteasome, which may explain increased TDP-43 protein levels found in both sporadic and C9orf72 amyotrophic lateral sclerosis/frontotemporal lobar degeneration frontal cortex and hippocampus. Fibroblasts derived from sporadic patients, but not C9orf72 patients, demonstrated the ability to sequester cytoplasmic TDP-43 into aggresomes via microtubule-dependent mechanisms. TDP-43 aggresomes in vitro and TDP-43 neuronal inclusions in vivo were both tightly localized with autophagy markers and, therefore, were likely to function similarly as sites for autophagic degradation. The inability for C9orf72 fibroblasts to form TDP-43 aggresomes, together with the observations that TDP-43 protein was soluble in the cytoplasm and formed smaller inclusions in the C9orf72 brain compared with sporadic disease, suggests a loss of protein quality control response to sequester and degrade TDP-43 in C9orf72-related diseases.
Collapse
Affiliation(s)
- Samuel M Lee
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Seneshaw Asress
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Chadwick M Hales
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Marla Gearing
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Juan C Vizcarra
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Christina N Fournier
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - David A Gutman
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lih-Shen Chin
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Lian Li
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jonathan D Glass
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
43
|
Abstract
The discovery that repeat expansions in the C9orf72 gene are a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) has revolutionized our understanding of these diseases. Substantial headway has been made in characterizing C9orf72-mediated disease and unravelling its underlying aetiopathogenesis. Three main disease mechanisms have been proposed: loss of function of the C9orf72 protein and toxic gain of function from C9orf72 repeat RNA or from dipeptide repeat proteins produced by repeat-associated non-ATG translation. Several downstream processes across a range of cellular functions have also been implicated. In this article, we review the pathological and mechanistic features of C9orf72-associated FTD and ALS (collectively termed C9FTD/ALS), the model systems used to study these conditions, and the probable initiators of downstream disease mechanisms. We suggest that a combination of upstream mechanisms involving both loss and gain of function and downstream cellular pathways involving both cell-autonomous and non-cell-autonomous effects contributes to disease progression.
Collapse
Affiliation(s)
- Rubika Balendra
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, UCL, London, UK
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK. .,UK Dementia Research Institute at UCL, UCL Institute of Neurology, London, UK.
| |
Collapse
|
44
|
Yin P, Guo X, Yang W, Yan S, Yang S, Zhao T, Sun Q, Liu Y, Li S, Li XJ. Caspase-4 mediates cytoplasmic accumulation of TDP-43 in the primate brains. Acta Neuropathol 2019; 137:919-937. [PMID: 30810811 PMCID: PMC6531422 DOI: 10.1007/s00401-019-01979-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 12/12/2022]
Abstract
The cytoplasmic accumulation of the nuclear TAR DNA-binding protein 43 (TDP-43) is a pathologic hallmark in amyotrophic lateral sclerosis, frontotemporal lobar degeneration, and other neurological disorders. However, most transgenic TDP-43 rodent models show predominant nuclear distribution of TDP-43 in the brain. By expressing mutant TDP-43 (M337V) in the brains of rhesus monkeys and mice, we verified that mutant TDP-43 is distributed in the cytoplasm of the monkey brain and that the majority of mutant TDP-43 remains in the nuclei of the mouse brain. The primate-specific caspase-4, but not mouse homologue caspase-11, could remove the NLS-containing N-terminal domain and generate fragmented TDP-43 that accumulates in the cytoplasm. Moreover, increased expression of caspase-4 in the monkey brain promotes the cytoplasmic accumulation of endogenous TDP-43, and suppressing caspase-4 reduces the cytoplasmic distribution of endogenous TDP-43 in cultured human neural cells. Our findings suggest that primate-specific caspase-4-mediated cleavage of TDP-43 accounts for its cytoplasmic mislocalization in the primate brains and may serve as a potential therapeutic target.
Collapse
|
45
|
Barton SK, Gregory JM, Chandran S, Turner BJ. Could an Impairment in Local Translation of mRNAs in Glia be Contributing to Pathogenesis in ALS? Front Mol Neurosci 2019; 12:124. [PMID: 31164803 PMCID: PMC6536688 DOI: 10.3389/fnmol.2019.00124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/26/2019] [Indexed: 12/13/2022] Open
Abstract
One of the key pathways implicated in amyotrophic lateral sclerosis (ALS) pathogenesis is abnormal RNA processing. Studies to date have focussed on defects in RNA stability, splicing, and translation, but this review article will focus on the largely overlooked RNA processing mechanism of RNA trafficking, with particular emphasis on the importance of glia. In the central nervous system (CNS), oligodendrocytes can extend processes to myelinate and metabolically support up to 50 axons and astrocytes can extend processes to cover up to 100,000 synapses, all with differing local functional requirements. Furthermore, many of the proteins required in these processes are large, aggregation-prone proteins which would be difficult to transport in their fully translated, terminally-folded state. This, therefore, highlights a critical requirement in these cells for local control of protein translation, which is achieved through specific trafficking of mRNAs to each process and local translation therein. Given that a large number of RNA-binding proteins have been implicated in ALS, and RNA-binding proteins are essential for trafficking mRNAs from the nucleus to glial processes for local translation, RNA misprocessing in glial cells is a likely source of cellular dysfunction in ALS. To date, neurons have been the focus of ALS research, but an intrinsic deficit in glia, namely astrocytes and oligodendrocytes, could have an additive effect on declining neuronal function in ALS. This review article aims to highlight the key evidence that supports the contention that RNA trafficking deficits in astrocytes and oligodendrocytes may contribute to in ALS.
Collapse
Affiliation(s)
- Samantha K Barton
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia.,Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jenna M Gregory
- Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute at University of Edinburgh, Edinburgh, United Kingdom
| | - Siddharthan Chandran
- Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute at University of Edinburgh, Edinburgh, United Kingdom
| | - Bradley J Turner
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
46
|
Nguyen L, Cleary JD, Ranum LPW. Repeat-Associated Non-ATG Translation: Molecular Mechanisms and Contribution to Neurological Disease. Annu Rev Neurosci 2019; 42:227-247. [PMID: 30909783 DOI: 10.1146/annurev-neuro-070918-050405] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Microsatellite mutations involving the expansion of tri-, tetra-, penta-, or hexanucleotide repeats cause more than 40 different neurological disorders. Although, traditionally, the position of the repeat within or outside of an open reading frame has been used to focus research on disease mechanisms involving protein loss of function, protein gain of function, or RNA gain of function, the discoveries of bidirectional transcription and repeat-associated non-ATG (RAN) have blurred these distinctions. Here we review what is known about RAN proteins in disease, the mechanisms by which they are produced, and the novel therapeutic opportunities they provide.
Collapse
Affiliation(s)
- Lien Nguyen
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA;
| | - John Douglas Cleary
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA;
| | - Laura P W Ranum
- Center for NeuroGenetics, Department of Molecular Genetics and Microbiology, Genetics Institute, and McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida 32610, USA;
| |
Collapse
|
47
|
Molecular Mechanisms of Neurodegeneration Related to C9orf72 Hexanucleotide Repeat Expansion. Behav Neurol 2019; 2019:2909168. [PMID: 30774737 PMCID: PMC6350563 DOI: 10.1155/2019/2909168] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/28/2018] [Accepted: 09/18/2018] [Indexed: 12/11/2022] Open
Abstract
Two clinically distinct diseases, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), have recently been classified as two extremes of the FTD/ALS spectrum. The neuropathological correlate of FTD is frontotemporal lobar degeneration (FTLD), characterized by tau-, TDP-43-, and FUS-immunoreactive neuronal inclusions. An earlier discovery that a hexanucleotide repeat expansion mutation in chromosome 9 open reading frame 72 (C9orf72) gene causes ALS and FTD established a special subtype of ALS and FTLD with TDP-43 pathology (C9FTD/ALS). Normal individuals carry 2–10 hexanucleotide GGGGCC repeats in the C9orf72 gene, while more than a few hundred repeats represent a risk for ALS and FTD. The proposed molecular mechanisms by which C9orf72 repeat expansions induce neurodegenerative changes are C9orf72 loss-of-function through haploinsufficiency, RNA toxic gain-of-function, and gain-of-function through the accumulation of toxic dipeptide repeat proteins. However, many more cellular processes are affected by pathological processes in C9FTD/ALS, including nucleocytoplasmic transport, RNA processing, normal function of nucleolus, formation of membraneless organelles, translation, ubiquitin proteasome system, Notch signalling pathway, granule transport, and normal function of TAR DNA-binding protein 43 (TDP-43). Although the exact molecular mechanisms through which C9orf72 repeat expansions account for neurodegeneration have not been elucidated, some potential therapeutics, such as antisense oligonucleotides targeting hexanucleotide GGGGCC repeats in mRNA, were successful in preclinical trials and are awaiting phase 1 clinical trials. In this review, we critically discuss each proposed mechanism and provide insight into the most recent studies aiming to elucidate the molecular underpinnings of C9FTD/ALS.
Collapse
|
48
|
Vatsavayai SC, Nana AL, Yokoyama JS, Seeley WW. C9orf72-FTD/ALS pathogenesis: evidence from human neuropathological studies. Acta Neuropathol 2019; 137:1-26. [PMID: 30368547 DOI: 10.1007/s00401-018-1921-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
What are the most important and treatable pathogenic mechanisms in C9orf72-FTD/ALS? Model-based efforts to address this question are forging ahead at a blistering pace, often with conflicting results. But what does the human neuropathological literature reveal? Here, we provide a critical review of the human studies to date, seeking to highlight key gaps or uncertainties in our knowledge. First, we engage the C9orf72-specific mechanisms, including C9orf72 haploinsufficiency, repeat RNA foci, and dipeptide repeat protein inclusions. We then turn to some of the most prominent C9orf72-associated features, such as TDP-43 loss-of-function, TDP-43 aggregation, and nuclear transport defects. Finally, we review potential disease-modifying epigenetic and genetic factors and the natural history of the disease across the lifespan. Throughout, we emphasize the importance of anatomical precision when studying how candidate mechanisms relate to neuronal, regional, and behavioral findings. We further highlight methodological approaches that may help address lingering knowledge gaps and uncertainties, as well as other logical next steps for the field. We conclude that anatomically oriented human neuropathological studies have a critical role to play in guiding this fast-moving field toward effective new therapies.
Collapse
Affiliation(s)
- Sarat C Vatsavayai
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Alissa L Nana
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - Jennifer S Yokoyama
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA
| | - William W Seeley
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, USA.
- Department of Pathology, University of California, San Francisco, Box 1207, San Francisco, CA, 94143-1207, USA.
| |
Collapse
|
49
|
Abstract
Microsatellite expansions cause more than 40 neurological disorders, including Huntington's disease, myotonic dystrophy, and C9ORF72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD). These repeat expansion mutations can produce repeat-associated non-ATG (RAN) proteins in all three reading frames, which accumulate in disease-relevant tissues. There has been considerable interest in RAN protein products and their downstream consequences, particularly for the dipeptide proteins found in C9ORF72 ALS/FTD. Understanding how RAN translation occurs, what cellular factors contribute to RAN protein accumulation, and how these proteins contribute to disease should lead to a better understanding of the basic mechanisms of gene expression and human disease.
Collapse
Affiliation(s)
- John Douglas Cleary
- From the Center for NeuroGenetics
- Departments of Molecular Genetics and Microbiology and
- Genetics Institute, and
| | - Amrutha Pattamatta
- From the Center for NeuroGenetics
- Departments of Molecular Genetics and Microbiology and
- Genetics Institute, and
| | - Laura P W Ranum
- From the Center for NeuroGenetics,
- Departments of Molecular Genetics and Microbiology and
- Genetics Institute, and
- Neurology, College of Medicine
- McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
| |
Collapse
|
50
|
Patient-derived frontotemporal lobar degeneration brain extracts induce formation and spreading of TDP-43 pathology in vivo. Nat Commun 2018; 9:4220. [PMID: 30310141 PMCID: PMC6181940 DOI: 10.1038/s41467-018-06548-9] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/14/2018] [Indexed: 12/12/2022] Open
Abstract
The stereotypical distribution of TAR DNA-binding 43 protein (TDP-43) aggregates in frontotemporal lobar degeneration (FTLD-TDP) suggests that pathological TDP-43 spreads throughout the brain via cell-to-cell transmission and correlates with disease progression, but no in vivo experimental data support this hypothesis. We first develop a doxycycline-inducible cell line expressing GFP-tagged cytoplasmic TDP-43 protein (iGFP-NLSm) as a cell-based system to screen and identify seeding activity of human brain-derived pathological TDP-43 isolated from sporadic FTLD-TDP and familial cases with Granulin (FTLD-TDP-GRN) or C9orf72 repeat expansion mutations (FTLD-TDP-C9+). We demonstrate that intracerebral injections of biologically active pathogenic FTLD-TDP seeds into transgenic mice expressing cytoplasmic human TDP-43 (lines CamKIIa-hTDP-43NLSm, rNLS8, and CamKIIa-208) and non-transgenic mice led to the induction of de-novo TDP-43 pathology. Moreover, TDP-43 pathology progressively spreads throughout the brain in a time-dependent manner via the neuroanatomic connectome. Our study suggests that the progression of FTLD-TDP reflects the templated cell-to-cell transneuronal spread of pathological TDP-43.
Collapse
|