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Ghaffari LT, Trotti D, Haeusler AR. Differential response of C9orf72 transcripts following neuronal depolarization. iScience 2023; 26:106959. [PMID: 37332610 PMCID: PMC10272498 DOI: 10.1016/j.isci.2023.106959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/19/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023] Open
Abstract
The (G4C2)n nucleotide repeat expansion (NRE) mutation in C9orf72 is the most common genetic cause of ALS and FTD. The biological functions of C9orf72 are becoming understood, but it is unclear if this gene is regulated in a neural-specific manner. Neuronal activity is a crucial modifier of biological processes in health and neurodegenerative disease contexts. Here, we show that prolonged membrane depolarization in healthy human iPSC-cortical neurons leads to a significant downregulation of a transcript variant 3 (V3) of C9orf72, with a concomitant increase in variant 2 (V2), which leads to total C9orf72 RNA transcript levels remaining unchanged. However, the same response is not observed in cortical neurons derived from patients with the C9-NRE mutation. These findings reveal the impact of depolarization on C9orf72 transcripts, and how this response diverges in C9-NRE-carriers, which may have important implications in the underlying unique clinical associations of C9-NRE transcripts and disease pathogenesis.
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Affiliation(s)
- Layla T. Ghaffari
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Davide Trotti
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Aaron R. Haeusler
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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2
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Key role of Rho GTPases in motor disorders associated with neurodevelopmental pathologies. Mol Psychiatry 2023; 28:118-126. [PMID: 35918397 DOI: 10.1038/s41380-022-01702-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 06/24/2022] [Accepted: 07/02/2022] [Indexed: 01/07/2023]
Abstract
Growing evidence suggests that Rho GTPases and molecules involved in their signaling pathways play a major role in the development of the central nervous system (CNS). Whole exome sequencing (WES) and de novo examination of mutations, including SNP (Single Nucleotide Polymorphism) in genes coding for the molecules of their signaling cascade, has allowed the recent discovery of dominant autosomic mutations and duplication or deletion of candidates in the field of neurodevelopmental diseases (NDD). Epidemiological studies show that the co-occurrence of several of these neurological pathologies may indeed be the rule. The regulators of Rho GTPases have often been considered for cognitive diseases such as intellectual disability (ID) and autism. But, in a remarkable way, mild to severe motor symptoms are now reported in autism and other cognitive NDD. Although a more abundant litterature reports the involvement of Rho GTPases and signaling partners in cognitive development, molecular investigations on their roles in central nervous system (CNS) development or degenerative CNS pathologies also reveal their role in embryonic and perinatal motor wiring through axon guidance and later in synaptic plasticity. Thus, Rho family small GTPases have been revealed to play a key role in brain functions including learning and memory but their precise role in motor development and associated symptoms in NDD has been poorly scoped so far, despite increasing clinical data highlighting the links between cognition and motor development. Indeed, early impairements in fine or gross motor performance is often an associated feature of NDDs, which then impact social communication, cognition, emotion, and behavior. We review here recent insights derived from clinical developmental neurobiology in the field of Rho GTPases and NDD (autism spectrum related disorder (ASD), ID, schizophrenia, hypotonia, spastic paraplegia, bipolar disorder and dyslexia), with a specific focus on genetic alterations affecting Rho GTPases that are involved in motor circuit development.
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3
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Cang X, Wang Y, Zeng J, Gao J, Yu Q, Lu C, Xu F, Lin J, Zhu J, Wang X. C9orf72 knockdown alleviates hepatic insulin resistance by promoting lipophagy. Biochem Biophys Res Commun 2022; 588:15-22. [PMID: 34942529 DOI: 10.1016/j.bbrc.2021.12.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 01/08/2023]
Abstract
Insulin resistance (IR) attributed by the deficiency of lipophagy, is an abnormal state of downregulation of insulin-mediated glucose uptake and use into the liver. Chromosome 9 open reading frame 72 (C9orf72) variously modulates autophagy. We investigated the role and the downstream pathway of C9orf72 in hepatic IR. We found that C9orf72 knockdown alleviated hepatic IR by lipophagy promotion in T2DM mice and in IR-challenged hepatocytes in vitro. C9orf72 interacted with and activated cell division cycle 42 (Cdc42) protein in IR-challenged hepatocytes, Which in turn, inhibits lipophagy by promoting neural Wiskott-Aldrich syndrome protein (N-WASP) expression and activation. C9orf72 inhibited lipophagy by activating the Cdc42/N-WASP axis to facilitate hepatic IR; therefore, the knockdown of C9orf72 may be potentially therapeutic for the treatment of IR.
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Affiliation(s)
- Xiaomin Cang
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, The First People's Hospital of Nantong, Nantong, Jiangsu, China
| | - Yu Wang
- Department of Hepatobiliary Surgery, Jintan Affiliated Hospital of Jiangsu University, Changzhou, China
| | - Jia Zeng
- Department of Pathogen Biology, Medical College, Nantong University, Nantong, Jiangsu, China
| | - Jingwen Gao
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qianqian Yu
- Department of Radiotherapy, Jintan Affiliated Hospital of Jiangsu University, Changzhou, China
| | - Chunfeng Lu
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, The First People's Hospital of Nantong, Nantong, Jiangsu, China
| | - Feng Xu
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, The First People's Hospital of Nantong, Nantong, Jiangsu, China
| | - Jiaxi Lin
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jinzhou Zhu
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, China.
| | - Xueqin Wang
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, The First People's Hospital of Nantong, Nantong, Jiangsu, China.
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Bonifacino T, Zerbo RA, Balbi M, Torazza C, Frumento G, Fedele E, Bonanno G, Milanese M. Nearly 30 Years of Animal Models to Study Amyotrophic Lateral Sclerosis: A Historical Overview and Future Perspectives. Int J Mol Sci 2021; 22:ijms222212236. [PMID: 34830115 PMCID: PMC8619465 DOI: 10.3390/ijms222212236] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal, multigenic, multifactorial, and non-cell autonomous neurodegenerative disease characterized by upper and lower motor neuron loss. Several genetic mutations lead to ALS development and many emerging gene mutations have been discovered in recent years. Over the decades since 1990, several animal models have been generated to study ALS pathology including both vertebrates and invertebrates such as yeast, worms, flies, zebrafish, mice, rats, guinea pigs, dogs, and non-human primates. Although these models show different peculiarities, they are all useful and complementary to dissect the pathological mechanisms at the basis of motor neuron degeneration and ALS progression, thus contributing to the development of new promising therapeutics. In this review, we describe the up to date and available ALS genetic animal models, classified by the different genetic mutations and divided per species, pointing out their features in modeling, the onset and progression of the pathology, as well as their specific pathological hallmarks. Moreover, we highlight similarities, differences, advantages, and limitations, aimed at helping the researcher to select the most appropriate experimental animal model, when designing a preclinical ALS study.
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Affiliation(s)
- Tiziana Bonifacino
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Genoa, Italy
| | - Roberta Arianna Zerbo
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Matilde Balbi
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Carola Torazza
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Giulia Frumento
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
| | - Ernesto Fedele
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
- Correspondence:
| | - Giambattista Bonanno
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Marco Milanese
- Pharmacology and Toxicology Unit, Department of Pharmacy, University of Genoa, 16148 Genoa, Italy; (T.B.); (R.A.Z.); (M.B.); (C.T.); (G.F.); (G.B.); (M.M.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Genoa, Italy
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Liguori F, Amadio S, Volonté C. Fly for ALS: Drosophila modeling on the route to amyotrophic lateral sclerosis modifiers. Cell Mol Life Sci 2021; 78:6143-6160. [PMID: 34322715 PMCID: PMC11072332 DOI: 10.1007/s00018-021-03905-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rare, devastating disease, causing movement impairment, respiratory failure and ultimate death. A plethora of genetic, cellular and molecular mechanisms are involved in ALS signature, although the initiating causes and progressive pathological events are far from being understood. Drosophila research has produced seminal discoveries for more than a century and has been successfully used in the past 25 years to untangle the process of ALS pathogenesis, and recognize potential markers and novel strategies for therapeutic solutions. This review will provide an updated view of several ALS modifiers validated in C9ORF72, SOD1, FUS, TDP-43 and Ataxin-2 Drosophila models. We will discuss basic and preclinical findings, illustrating recent developments and novel breakthroughs, also depicting unsettled challenges and limitations in the Drosophila-ALS field. We intend to stimulate a renewed debate on Drosophila as a screening route to identify more successful disease modifiers and neuroprotective agents.
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Affiliation(s)
- Francesco Liguori
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy
| | - Susanna Amadio
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy
| | - Cinzia Volonté
- Preclinical Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 65, 00143, Rome, Italy.
- Institute for Systems Analysis and Computer Science "A. Ruberti", National Research Council (IASI-CNR), Via dei Taurini 19, 00185, Rome, Italy.
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Layalle S, They L, Ourghani S, Raoul C, Soustelle L. Amyotrophic Lateral Sclerosis Genes in Drosophila melanogaster. Int J Mol Sci 2021; 22:ijms22020904. [PMID: 33477509 PMCID: PMC7831090 DOI: 10.3390/ijms22020904] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating adult-onset neurodegenerative disease characterized by the progressive degeneration of upper and lower motoneurons. Most ALS cases are sporadic but approximately 10% of ALS cases are due to inherited mutations in identified genes. ALS-causing mutations were identified in over 30 genes with superoxide dismutase-1 (SOD1), chromosome 9 open reading frame 72 (C9orf72), fused in sarcoma (FUS), and TAR DNA-binding protein (TARDBP, encoding TDP-43) being the most frequent. In the last few decades, Drosophila melanogaster emerged as a versatile model for studying neurodegenerative diseases, including ALS. In this review, we describe the different Drosophila ALS models that have been successfully used to decipher the cellular and molecular pathways associated with SOD1, C9orf72, FUS, and TDP-43. The study of the known fruit fly orthologs of these ALS-related genes yielded significant insights into cellular mechanisms and physiological functions. Moreover, genetic screening in tissue-specific gain-of-function mutants that mimic ALS-associated phenotypes identified disease-modifying genes. Here, we propose a comprehensive review on the Drosophila research focused on four ALS-linked genes that has revealed novel pathogenic mechanisms and identified potential therapeutic targets for future therapy.
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Affiliation(s)
- Sophie Layalle
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Laetitia They
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Sarah Ourghani
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
| | - Cédric Raoul
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
- Laboratory of Neurobiology, Kazan Federal University, 420008 Kazan, Russia
- Correspondence: (C.R.); (L.S.)
| | - Laurent Soustelle
- The Neuroscience Institute of Montpellier, INSERM, University of Montpellier, 34091 Montpellier, France; (S.L.); (L.T.); (S.O.)
- Correspondence: (C.R.); (L.S.)
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7
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Fortier G, Butti Z, Patten SA. Modelling C9orf72-Related Amyotrophic Lateral Sclerosis in Zebrafish. Biomedicines 2020; 8:E440. [PMID: 33096681 PMCID: PMC7589578 DOI: 10.3390/biomedicines8100440] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/16/2020] [Accepted: 10/17/2020] [Indexed: 12/12/2022] Open
Abstract
A hexanucleotide repeat expansion within the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and its discovery has revolutionized our understanding of this devastating disease. Model systems are a valuable tool for studying ALS pathobiology and potential therapies. The zebrafish (Danio rerio) has particularly become a useful model organism to study neurological diseases, including ALS, due to high genetic and physiological homology to mammals, and sensitivity to various genetic and pharmacological manipulations. In this review we summarize the zebrafish models that have been used to study the pathology of C9orf72-related ALS. We discuss their value in providing mechanistic insights and their potential use for drug discovery.
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Affiliation(s)
- Gabrielle Fortier
- INRS-Centre Armand-Frappier Santé et Biotechnologie, Laval, QC H7V 1B7, Canada; (G.F.); (Z.B.)
| | - Zoé Butti
- INRS-Centre Armand-Frappier Santé et Biotechnologie, Laval, QC H7V 1B7, Canada; (G.F.); (Z.B.)
| | - Shunmoogum A. Patten
- INRS-Centre Armand-Frappier Santé et Biotechnologie, Laval, QC H7V 1B7, Canada; (G.F.); (Z.B.)
- Centre d’Excellence en Recherche sur les Maladies Orphelines—Fondation Courtois (CERMO-FC), Université du Québec à Montréal (UQAM), Montréal, QC H2X 3Y7, Canada
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8
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Kim T, Song B, Lee IS. Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:E4859. [PMID: 32660023 PMCID: PMC7402321 DOI: 10.3390/ijms21144859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.
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Affiliation(s)
| | | | - Im-Soon Lee
- Department of Biological Sciences, Center for CHANS, Konkuk University, Seoul 05029, Korea; (T.K.); (B.S.)
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Morrice JR, Gregory-Evans CY, Shaw CA. Investigating microglia during motor neuron degeneration using a zebrafish model. Micron 2020; 133:102852. [PMID: 32203887 DOI: 10.1016/j.micron.2020.102852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/14/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022]
Abstract
Many different types of pathologies can arise in the central nervous system (CNS), such as neurodegeneration. The incidence of neurodegenerative diseases continues to increase, yet the pathogenesis underlying most neurodegenerative diseases, notably in amyotrophic lateral sclerosis (ALS), remains elusive. Neuronal support cells, or glia, are known to play a crucial role in ALS. Microglia are the resident immune cells of the CNS and also have neurotrophic support functions. These cells have a disease-modifying function in ALS, yet this role is not well understood. A likely reason for this is that the intact CNS is particularly challenging to access for investigation in patients and in most animal models, which has impeded research in this field. The zebrafish is emerging as a robust model system to investigate cells in vivo, and offer distinct advantages over other vertebrate models for investigating neurodegenerative diseases. Live imaging in vivo is a powerful technique to characterize the role of dynamic cells such as microglia during neurodegeneration, and zebrafish provide a convenient means for live imaging. Here, we discuss the zebrafish as a model for live imaging, provide a brief overview of available high resolution imaging platforms that accommodate zebrafish, and describe our own in vivo studies on the role of microglia during motor neuron degeneration. Live in vivo imaging is anticipated to provide invaluable advancements to defining the pathogenesis underlying neurodegenerative diseases, which may in turn allow for more specifically targeted therapeutics.
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Affiliation(s)
- Jessica R Morrice
- Experimental Medicine Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Cheryl Y Gregory-Evans
- Experimental Medicine Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada; Department of Ophthalmology and Visual Sciences, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Christopher A Shaw
- Experimental Medicine Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada; Department of Ophthalmology and Visual Sciences, University of British Columbia, 2329 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
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10
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Xiao S, McKeever PM, Lau A, Robertson J. Synaptic localization of C9orf72 regulates post-synaptic glutamate receptor 1 levels. Acta Neuropathol Commun 2019; 7:161. [PMID: 31651360 PMCID: PMC6813971 DOI: 10.1186/s40478-019-0812-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022] Open
Abstract
A hexanucleotide repeat expansion in a noncoding region of C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Reduction of select or total C9orf72 transcript and protein levels is observed in postmortem C9-ALS/FTD tissue, and loss of C9orf72 orthologues in zebrafish and C. elegans results in motor deficits. However, how the reduction in C9orf72 in ALS and FTD might contribute to the disease process remains poorly understood. It has been shown that C9orf72 interacts and forms a complex with SMCR8 and WDR41, acting as a guanine exchange factor for Rab GTPases. Given the known synaptosomal compartmentalization of C9orf72-interacting Rab GTPases, we hypothesized that C9orf72 localization to synaptosomes would be required for the regulation of Rab GTPases and receptor trafficking. This study combined synaptosomal and post-synaptic density preparations together with a knockout-confirmed monoclonal antibody for C9orf72 to assess the localization and role of C9orf72 in the synaptosomes of mouse forebrains. Here, we found C9orf72 to be localized to both the pre- and post-synaptic compartment, as confirmed by both post-synaptic immunoprecipitation and immunofluorescence labelling. In C9orf72 knockout (C9-KO) mice, we demonstrated that pre-synaptic Rab3a, Rab5, and Rab11 protein levels remained stable compared with wild-type littermates (C9-WT). Strikingly, post-synaptic preparations from C9-KO mouse forebrains demonstrated a complete loss of Smcr8 protein levels, together with a significant downregulation of Rab39b and a concomitant upregulation of GluR1 compared with C9-WT mice. We confirmed the localization of Rab39b downregulation and GluR1 upregulation to the dorsal hippocampus of C9-KO mice by immunofluorescence. These results indicate that C9orf72 is essential for the regulation of post-synaptic receptor levels, and implicates loss of C9orf72 in contributing to synaptic dysfunction and related excitotoxicity in ALS and FTD.
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Rostalski H, Leskelä S, Huber N, Katisko K, Cajanus A, Solje E, Marttinen M, Natunen T, Remes AM, Hiltunen M, Haapasalo A. Astrocytes and Microglia as Potential Contributors to the Pathogenesis of C9orf72 Repeat Expansion-Associated FTLD and ALS. Front Neurosci 2019; 13:486. [PMID: 31156371 PMCID: PMC6529740 DOI: 10.3389/fnins.2019.00486] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/29/2019] [Indexed: 12/11/2022] Open
Abstract
Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative diseases with a complex, but often overlapping, genetic and pathobiological background and thus they are considered to form a disease spectrum. Although neurons are the principal cells affected in FTLD and ALS, increasing amount of evidence has recently proposed that other central nervous system-resident cells, including microglia and astrocytes, may also play roles in neurodegeneration in these diseases. Therefore, deciphering the mechanisms underlying the disease pathogenesis in different types of brain cells is fundamental in order to understand the etiology of these disorders. The major genetic cause of FTLD and ALS is a hexanucleotide repeat expansion (HRE) in the intronic region of the C9orf72 gene. In neurons, specific pathological hallmarks, including decreased expression of the C9orf72 RNA and proteins and generation of toxic RNA and protein species, and their downstream effects have been linked to C9orf72 HRE-associated FTLD and ALS. In contrast, it is still poorly known to which extent these pathological changes are presented in other brain cells. Here, we summarize the current literature on the potential role of astrocytes and microglia in C9orf72 HRE-linked FTLD and ALS and discuss their possible phenotypic alterations and neurotoxic mechanisms that may contribute to neurodegeneration in these diseases.
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Affiliation(s)
- Hannah Rostalski
- 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
| | - Nadine Huber
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Kasper Katisko
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland
| | - Antti Cajanus
- Institute of Clinical Medicine - Neurology, 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
| | - Mikael Marttinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Teemu Natunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Anne M Remes
- Medical Research Center, Oulu University Hospital, Oulu, Finland.,Research Unit of Clinical Neuroscience, Neurology, University of Oulu, Oulu, 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
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