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Papazoglou A, Henseler C, Weickhardt S, Teipelke J, Papazoglou P, Daubner J, Schiffer T, Krings D, Broich K, Hescheler J, Sachinidis A, Ehninger D, Scholl C, Haenisch B, Weiergräber M. Sex- and region-specific cortical and hippocampal whole genome transcriptome profiles from control and APP/PS1 Alzheimer's disease mice. PLoS One 2024; 19:e0296959. [PMID: 38324617 PMCID: PMC10849391 DOI: 10.1371/journal.pone.0296959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/21/2023] [Indexed: 02/09/2024] Open
Abstract
A variety of Alzheimer's disease (AD) mouse models has been established and characterized within the last decades. To get an integrative view of the sophisticated etiopathogenesis of AD, whole genome transcriptome studies turned out to be indispensable. Here we carried out microarray data collection based on RNA extracted from the retrosplenial cortex and hippocampus of age-matched, eight months old male and female APP/PS1 AD mice and control animals to perform sex- and brain region specific analysis of transcriptome profiles. The results of our studies reveal novel, detailed insight into differentially expressed signature genes and related fold changes in the individual APP/PS1 subgroups. Gene ontology and Venn analysis unmasked that intersectional, upregulated genes were predominantly involved in, e.g., activation of microglial, astrocytic and neutrophilic cells, innate immune response/immune effector response, neuroinflammation, phagosome/proteasome activation, and synaptic transmission. The number of (intersectional) downregulated genes was substantially less in the different subgroups and related GO categories included, e.g., the synaptic vesicle docking/fusion machinery, synaptic transmission, rRNA processing, ubiquitination, proteasome degradation, histone modification and cellular senescence. Importantly, this is the first study to systematically unravel sex- and brain region-specific transcriptome fingerprints/signature genes in APP/PS1 mice. The latter will be of central relevance in future preclinical and clinical AD related studies, biomarker characterization and personalized medicinal approaches.
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Affiliation(s)
- Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Sandra Weickhardt
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Jenni Teipelke
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Panagiota Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Teresa Schiffer
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Damian Krings
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Jürgen Hescheler
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Cologne, Germany
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Agapios Sachinidis
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Cologne, Germany
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Dan Ehninger
- Translational Biogerontology, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Bonn, Germany
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Bonn, Germany
| | - Catharina Scholl
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
| | - Britta Haenisch
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Bonn, Germany
- Center for Translational Medicine, Medical Faculty, University of Bonn, Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Bonn, Germany
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Cologne, Germany
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Cologne, Germany
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2
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Veselkina ER, Trostnikov MV, Roshina NV, Pasyukova EG. The Effect of the Tau Protein on D. melanogaster Lifespan Depends on GSK3 Expression and Sex. Int J Mol Sci 2023; 24:2166. [PMID: 36768490 PMCID: PMC9916465 DOI: 10.3390/ijms24032166] [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: 12/05/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
The microtubule-associated conserved protein tau has attracted significant attention because of its essential role in the formation of pathological changes in the nervous system, which can reduce longevity. The study of the effects caused by tau dysfunction and the molecular mechanisms underlying them is complicated because different forms of tau exist in humans and model organisms, and the changes in protein expression can be multidirectional. In this article, we show that an increase in the expression of the main isoform of the Drosophila melanogaster tau protein in the nervous system has differing effects on lifespan depending on the sex of individuals but has no effect on the properties of the nervous system, in particular, the synaptic activity and distribution of another microtubule-associated protein, Futsch, in neuromuscular junctions. Reduced expression of tau in the nervous system does not affect the lifespan of wild-type flies, but it does increase the lifespan dramatically shortened by overexpression of the shaggy gene encoding the GSK3 (Glycogen Synthase Kinase 3) protein kinase, which is one of the key regulators of tau phosphorylation levels. This effect is accompanied by the normalization of the Futsch protein distribution impaired by shaggy overexpression. The results presented in this article demonstrate that multidirectional changes in tau expression can lead to effects that depend on the sex of individuals and the expression level of GSK3.
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Affiliation(s)
- Ekaterina R. Veselkina
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
| | - Mikhail V. Trostnikov
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
| | - Natalia V. Roshina
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
- Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena G. Pasyukova
- Institute of Molecular Genetics, National Research Centre “Kurchatov Institute”, 123182 Moscow, Russia
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3
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Yang X, Ma Z, Lian P, Xu Y, Cao X. Common mechanisms underlying axonal transport deficits in neurodegenerative diseases: a mini review. Front Mol Neurosci 2023; 16:1172197. [PMID: 37168679 PMCID: PMC10164940 DOI: 10.3389/fnmol.2023.1172197] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/05/2023] [Indexed: 05/13/2023] Open
Abstract
Many neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the accumulation of pathogenic proteins and abnormal localization of organelles. These pathological features may be related to axonal transport deficits in neurons, which lead to failures in pathological protein targeting to specific sites for degradation and organelle transportation to designated areas needed for normal physiological functioning. Axonal transport deficits are most likely early pathological events in such diseases and gradually lead to the loss of axonal integrity and other degenerative changes. In this review, we investigated reports of mechanisms underlying the development of axonal transport deficits in a variety of common neurodegenerative diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease and Huntington's disease to provide new ideas for therapeutic targets that may be used early in the disease process. The mechanisms can be summarized as follows: (1) motor protein changes including expression levels and post-translational modification alteration; (2) changes in microtubules including reducing stability and disrupting tracks; (3) changes in cargoes including diminished binding to motor proteins. Future studies should determine which axonal transport defects are disease-specific and whether they are suitable therapeutic targets in neurodegenerative diseases.
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4
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Gambino G, Rossi L, Iacopetti P, Ghezzani C, Guidi P, Linsalata S, Ippolito C, Salvetti A. Microtubule-associated protein 1B is implicated in stem cell commitment and nervous system regeneration in planarians. PLoS One 2022; 17:e0278966. [PMID: 36508441 PMCID: PMC9744283 DOI: 10.1371/journal.pone.0278966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
Microtubule-associated 1B (MAP1B) proteins are expressed at the nervous system level where they control cytoskeleton activity and regulate neurotransmitter release. Here, we report about the identification of a planarian MAP1B factor (DjMap1B) that is enriched in cephalic ganglia and longitudinal nerve cords but not in neoblasts, the plentiful population of adult stem cells present in planarians, thanks to which these animals can continuously cell turnover and regenerate any lost body parts. DjMap1B knockdown induces morphological anomalies in the nervous system and affects neoblast commitment. Our data put forward a correlation between a MAP1B factor and stem cells and suggest a function of the nervous system in non-cell autonomous control of planarian stem cells.
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Affiliation(s)
- Gaetana Gambino
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Leonardo Rossi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paola Iacopetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Claudio Ghezzani
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Patrizia Guidi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Stefania Linsalata
- Medical Physics Unit, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy
| | - Chiara Ippolito
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Alessandra Salvetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- * E-mail:
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5
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Deolankar SC, Najar MA, Raghu SV, Prasad TSK. Aβ42 Expressing Drosophila melanogaster Model for Alzheimer's Disease: Quantitative Proteomics Identifies Altered Protein Dynamics of Relevance to Neurodegeneration. OMICS : A JOURNAL OF INTEGRATIVE BIOLOGY 2022; 26:51-63. [PMID: 35006003 DOI: 10.1089/omi.2021.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Production and deposition of β-amyloid peptides (Aβ) are among the major hallmarks of the pathogenesis of Alzheimer's disease (AD). Mapping the altered protein dynamics associated with Aβ accumulation and neuronal damage may open up new avenues to innovation for drug target discovery in AD. Using quantitative proteomics, we report new findings from the amyloid beta-peptide with 42 amino acids (Aβ42) expressing Drosophila melanogaster model for AD compared to that of the wild-type flies. We identified 302,241 peptide-spectrum matches with 25,641 nonredundant peptides corresponding to 7959 D. melanogaster proteins. Furthermore, we unraveled 538 significantly altered proteins in Aβ42 expressing flies. These differentially expressed proteins were enriched for biological processes associated with neuronal damage leading to AD progression. We also identified 463 unique post-translational modification events mapping to 202 proteins from the same dataset. Among these, 303 modified peptides corresponding to 246 proteins were also altered in the AD model. These modified proteins are known to be involved in the disruption of molecular functions maintaining neuronal plasticity. This study provides new molecular leads on altered protein dynamics relevant to neurodegeneration, neuroplasticity, and AD progression induced by Aβ42 toxicity. These proteins may prove useful to discover new drugs in an AD model of D. melanogaster and evaluate their efficacy and mode of molecular action in the future.
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Affiliation(s)
- Sayali Chandrashekhar Deolankar
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Mohammad Altaf Najar
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Shamprasad Varija Raghu
- Neurogenetics Laboratory, Department of Applied Zoology, Mangalore University, Mangalore, India
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6
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Prokop A. Cytoskeletal organization of axons in vertebrates and invertebrates. J Cell Biol 2021; 219:151734. [PMID: 32369543 PMCID: PMC7337489 DOI: 10.1083/jcb.201912081] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/11/2022] Open
Abstract
The maintenance of axons for the lifetime of an organism requires an axonal cytoskeleton that is robust but also flexible to adapt to mechanical challenges and to support plastic changes of axon morphology. Furthermore, cytoskeletal organization has to adapt to axons of dramatically different dimensions, and to their compartment-specific requirements in the axon initial segment, in the axon shaft, at synapses or in growth cones. To understand how the cytoskeleton caters to these different demands, this review summarizes five decades of electron microscopic studies. It focuses on the organization of microtubules and neurofilaments in axon shafts in both vertebrate and invertebrate neurons, as well as the axon initial segments of vertebrate motor- and interneurons. Findings from these ultrastructural studies are being interpreted here on the basis of our contemporary molecular understanding. They strongly suggest that axon architecture in animals as diverse as arthropods and vertebrates is dependent on loosely cross-linked bundles of microtubules running all along axons, with only minor roles played by neurofilaments.
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Affiliation(s)
- Andreas Prokop
- School of Biology, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
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7
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Vargas EJM, Matamoros AJ, Qiu J, Jan CH, Wang Q, Gorczyca D, Han TW, Weissman JS, Jan YN, Banerjee S, Song Y. The microtubule regulator ringer functions downstream from the RNA repair/splicing pathway to promote axon regeneration. Genes Dev 2020; 34:194-208. [PMID: 31919191 PMCID: PMC7000917 DOI: 10.1101/gad.331330.119] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/10/2019] [Indexed: 12/17/2022]
Abstract
In this study, Vargas et al. set out to elucidate the downstream effectors of the Rtca-mediated RNA repair/splicing pathway. Using genome-wide transcriptome analysis, the authors demonstrate that the microtubule-associated protein (MAP) tubulin polymerization-promoting protein (TPPP) ringer functions downstream from and is suppressed by Rtca via Xbp1-dependent transcription. Ringer cell-autonomously promotes axon regeneration in the peripheral and central nervous system. Promoting axon regeneration in the central and peripheral nervous system is of clinical importance in neural injury and neurodegenerative diseases. Both pro- and antiregeneration factors are being identified. We previously reported that the Rtca mediated RNA repair/splicing pathway restricts axon regeneration by inhibiting the nonconventional splicing of Xbp1 mRNA under cellular stress. However, the downstream effectors remain unknown. Here, through transcriptome profiling, we show that the tubulin polymerization-promoting protein (TPPP) ringmaker/ringer is dramatically increased in Rtca-deficient Drosophila sensory neurons, which is dependent on Xbp1. Ringer is expressed in sensory neurons before and after injury, and is cell-autonomously required for axon regeneration. While loss of ringer abolishes the regeneration enhancement in Rtca mutants, its overexpression is sufficient to promote regeneration both in the peripheral and central nervous system. Ringer maintains microtubule stability/dynamics with the microtubule-associated protein futsch/MAP1B, which is also required for axon regeneration. Furthermore, ringer lies downstream from and is negatively regulated by the microtubule-associated deacetylase HDAC6, which functions as a regeneration inhibitor. Taken together, our findings suggest that ringer acts as a hub for microtubule regulators that relays cellular status information, such as cellular stress, to the integrity of microtubules in order to instruct neuroregeneration.
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Affiliation(s)
- Ernest J Monahan Vargas
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Andrew J Matamoros
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jingyun Qiu
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Calvin H Jan
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94158, USA.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Qin Wang
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - David Gorczyca
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Tina W Han
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94158, USA.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA.,Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Swati Banerjee
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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8
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Guo J, Cai Y, Ye X, Ma N, Wang Y, Yu B, Wan J. MiR-409-5p as a Regulator of Neurite Growth Is Down Regulated in APP/PS1 Murine Model of Alzheimer's Disease. Front Neurosci 2019; 13:1264. [PMID: 31849582 PMCID: PMC6892840 DOI: 10.3389/fnins.2019.01264] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/07/2019] [Indexed: 12/21/2022] Open
Abstract
Alzheimer’s disease (AD) is a heterogeneous neurodegenerative disease. Recent studies suggest that miRNA expression changes are associated with the development of AD. Our previous study showed that the expression level of miR-409-5p was stably downregulated in the early stage of APP/PS1 double transgenic mice model of AD. We now report that miR-409-5p impairs neurite outgrowth, decreases neuronal viability, and accelerates the progression of Aβ1–42-induced pathologies. In this study, we found that Aβ1–42 peptide significantly decreased the expression of miR-409-5p, which was consistent with the expression profile of miR-409-5p in the APP/PS1 mice cortexes. Plek was confirmed to be a potential regulatory target of miR-409-5p by luciferase assay and Western blotting. Overexpression of miR-409-5p has an obvious neurotoxicity in neuronal cell viability and differentiation, whereas Plek overexpression could partially rescue neurite outgrowth from this toxicity. Some cytoskeleton regulatory proteins have been found to be related to AD pathogenesis. Our data show some clues that cytoskeletal reorganization may play roles in AD pathology. The early downregulation of miR-409-5p in AD progression might be a self-protective reaction to alleviate the synaptic damage induced by Aβ, which may be used as a potential early biomarker of AD.
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Affiliation(s)
- Jing Guo
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Yifei Cai
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Xiaoyang Ye
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Nana Ma
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Yuan Wang
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Bo Yu
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Department of Dermatology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jun Wan
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
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9
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Qu Y, Hahn I, Lees M, Parkin J, Voelzmann A, Dorey K, Rathbone A, Friel CT, Allan VJ, Okenve-Ramos P, Sanchez-Soriano N, Prokop A. Efa6 protects axons and regulates their growth and branching by inhibiting microtubule polymerisation at the cortex. eLife 2019; 8:50319. [PMID: 31718774 PMCID: PMC6884004 DOI: 10.7554/elife.50319] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/06/2019] [Indexed: 12/12/2022] Open
Abstract
Cortical collapse factors affect microtubule (MT) dynamics at the plasma membrane. They play important roles in neurons, as suggested by inhibition of axon growth and regeneration through the ARF activator Efa6 in C. elegans, and by neurodevelopmental disorders linked to the mammalian kinesin Kif21A. How cortical collapse factors influence axon growth is little understood. Here we studied them, focussing on the function of Drosophila Efa6 in experimentally and genetically amenable fly neurons. First, we show that Drosophila Efa6 can inhibit MTs directly without interacting molecules via an N-terminal 18 amino acid motif (MT elimination domain/MTED) that binds tubulin and inhibits microtubule growth in vitro and cells. If N-terminal MTED-containing fragments are in the cytoplasm they abolish entire microtubule networks of mouse fibroblasts and whole axons of fly neurons. Full-length Efa6 is membrane-attached, hence primarily blocks MTs in the periphery of fibroblasts, and explorative MTs that have left axonal bundles in neurons. Accordingly, loss of Efa6 causes an increase of explorative MTs: in growth cones they enhance axon growth, in axon shafts they cause excessive branching, as well as atrophy through perturbations of MT bundles. Efa6 over-expression causes the opposite phenotypes. Taken together, our work conceptually links molecular and sub-cellular functions of cortical collapse factors to axon growth regulation and reveals new roles in axon branching and in the prevention of axonal atrophy. Furthermore, the MTED delivers a promising tool that can be used to inhibit MTs in a compartmentalised fashion when fusing it to specifically localising protein domains.
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Affiliation(s)
- Yue Qu
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Ines Hahn
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Meredith Lees
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Jill Parkin
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - André Voelzmann
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Karel Dorey
- Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Manchester, United Kingdom
| | - Alex Rathbone
- School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom
| | - Claire T Friel
- School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom
| | - Victoria J Allan
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
| | - Pilar Okenve-Ramos
- Department of Cellular and Molecular Physiology,Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Natalia Sanchez-Soriano
- Department of Cellular and Molecular Physiology,Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom
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10
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Hahn I, Voelzmann A, Liew YT, Costa-Gomes B, Prokop A. The model of local axon homeostasis - explaining the role and regulation of microtubule bundles in axon maintenance and pathology. Neural Dev 2019; 14:11. [PMID: 31706327 PMCID: PMC6842214 DOI: 10.1186/s13064-019-0134-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [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: 10/02/2019] [Indexed: 12/20/2022] Open
Abstract
Axons are the slender, cable-like, up to meter-long projections of neurons that electrically wire our brains and bodies. In spite of their challenging morphology, they usually need to be maintained for an organism's lifetime. This makes them key lesion sites in pathological processes of ageing, injury and neurodegeneration. The morphology and physiology of axons crucially depends on the parallel bundles of microtubules (MTs), running all along to serve as their structural backbones and highways for life-sustaining cargo transport and organelle dynamics. Understanding how these bundles are formed and then maintained will provide important explanations for axon biology and pathology. Currently, much is known about MTs and the proteins that bind and regulate them, but very little about how these factors functionally integrate to regulate axon biology. As an attempt to bridge between molecular mechanisms and their cellular relevance, we explain here the model of local axon homeostasis, based on our own experiments in Drosophila and published data primarily from vertebrates/mammals as well as C. elegans. The model proposes that (1) the physical forces imposed by motor protein-driven transport and dynamics in the confined axonal space, are a life-sustaining necessity, but pose a strong bias for MT bundles to become disorganised. (2) To counterbalance this risk, MT-binding and -regulating proteins of different classes work together to maintain and protect MT bundles as necessary transport highways. Loss of balance between these two fundamental processes can explain the development of axonopathies, in particular those linking to MT-regulating proteins, motors and transport defects. With this perspective in mind, we hope that more researchers incorporate MTs into their work, thus enhancing our chances of deciphering the complex regulatory networks that underpin axon biology and pathology.
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Affiliation(s)
- Ines Hahn
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - André Voelzmann
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Yu-Ting Liew
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Beatriz Costa-Gomes
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, The University of Manchester, School of Biology, Manchester, UK.
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11
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Drosophila Tau Negatively Regulates Translation and Olfactory Long-Term Memory, But Facilitates Footshock Habituation and Cytoskeletal Homeostasis. J Neurosci 2019; 39:8315-8329. [PMID: 31488613 DOI: 10.1523/jneurosci.0391-19.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/24/2019] [Accepted: 08/07/2019] [Indexed: 01/07/2023] Open
Abstract
Although the involvement of pathological tau in neurodegenerative dementias is indisputable, its physiological roles have remained elusive in part because its abrogation has been reported without overt phenotypes in mice and Drosophila This was addressed using the recently described Drosophila tauKO and Mi{MIC} mutants and focused on molecular and behavioral analyses. Initially, we show that Drosophila tau (dTau) loss precipitates dynamic cytoskeletal changes in the adult Drosophila CNS and translation upregulation. Significantly, we demonstrate for the first time distinct roles for dTau in adult mushroom body (MB)-dependent neuroplasticity as its downregulation within α'β'neurons impairs habituation. In accord with its negative regulation of translation, dTau loss specifically enhances protein synthesis-dependent long-term memory (PSD-LTM), but not anesthesia-resistant memory. In contrast, elevation of the protein in the MBs yielded premature habituation and depressed PSD-LTM. Therefore, tau loss in Drosophila dynamically alters brain cytoskeletal dynamics and profoundly affects neuronal proteostasis and plasticity.SIGNIFICANCE STATEMENT We demonstrate that despite modest sequence divergence, the Drosophila tau (dTau) is a true vertebrate tau ortholog as it interacts with the neuronal microtubule and actin cytoskeleton. Novel physiological roles for dTau in regulation of translation, long-term memory, and footshock habituation are also revealed. These emerging insights on tau physiological functions are invaluable for understanding the molecular pathways and processes perturbed in tauopathies.
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12
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Bodaleo F, Tapia-Monsalves C, Cea-Del Rio C, Gonzalez-Billault C, Nunez-Parra A. Structural and Functional Abnormalities in the Olfactory System of Fragile X Syndrome Models. Front Mol Neurosci 2019; 12:135. [PMID: 31191246 PMCID: PMC6548058 DOI: 10.3389/fnmol.2019.00135] [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: 01/14/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022] Open
Abstract
Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability. It is produced by mutation of the Fmr1 gene that encodes for the Fragile Mental Retardation Protein (FMRP), an important RNA-binding protein that regulates the expression of multiple proteins located in neuronal synapses. Individuals with FXS exhibit abnormal sensory information processing frequently leading to hypersensitivity across sensory modalities and consequently a wide array of behavioral symptoms. Insects and mammals engage primarily their sense of smell to create proper representations of the external world and guide adequate decision-making processes. This feature in combination with the exquisitely organized neuronal circuits found throughout the olfactory system (OS) and the wide expression of FMRP in brain regions that process olfactory information makes it an ideal model to study sensory alterations in FXS models. In the last decade several groups have taken advantage of these features and have used the OS of fruit fly and rodents to understand neuronal alteration giving rise to sensory perception issues. In this review article, we will discuss molecular, morphological and physiological aspects of the olfactory information processing in FXS models. We will highlight the decreased inhibitory/excitatory synaptic balance and the diminished synaptic plasticity found in this system resulting in behavioral alteration of individuals in the presence of odorant stimuli.
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Affiliation(s)
- Felipe Bodaleo
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Christian Cea-Del Rio
- Laboratory of Neurophysiopathology, Centro de Investigacion Biomedica y Aplicada (CIBAP), School of Medicine, Universidad de Santiago de Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cellular and Neuronal Dynamics, Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, United States
| | - Alexia Nunez-Parra
- Department of Biology, Faculty of Science, Universidad de Chile, Santiago, Chile.,Cell Physiology Center, Universidad de Chile, Santiago, Chile
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13
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Kaiser M, Arvidson R, Zarivach R, Adams ME, Libersat F. Molecular cross-talk in a unique parasitoid manipulation strategy. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 106:64-78. [PMID: 30508629 DOI: 10.1016/j.ibmb.2018.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/18/2018] [Accepted: 11/29/2018] [Indexed: 06/09/2023]
Abstract
Envenomation of cockroach cerebral ganglia by the parasitoid Jewel wasp, Ampulex compressa, induces specific, long-lasting behavioural changes. We hypothesized that this prolonged action results from venom-induced changes in brain neurochemistry. Here, we address this issue by first identifying molecular targets of the venom, i.e., proteins to which venom components bind and interact with to mediate altered behaviour. Our results show that venom components bind to synaptic proteins and likely interfere with both pre- and postsynaptic processes. Since behavioural changes induced by the sting are long-lasting and reversible, we hypothesized further that long-term effects of the venom must be mediated by up or down regulation of cerebral ganglia proteins. We therefore characterize changes in cerebral ganglia protein abundance of stung cockroaches at different time points after the sting by quantitative mass spectrometry. Our findings indicate that numerous proteins are differentially expressed in cerebral ganglia of stung cockroaches, many of which are involved in signal transduction, such as the Rho GTPase pathway, which is implicated in synaptic plasticity. Altogether, our data suggest that the Jewel wasp commandeers cockroach behaviour through molecular cross-talk between venom components and molecular targets in the cockroach central nervous system, leading to broad-based alteration of synaptic efficacy and behavioural changes that promote successful development of wasp progeny.
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Affiliation(s)
- Maayan Kaiser
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel
| | - Ryan Arvidson
- Graduate Program in Biochemistry and Molecular Biology, University of California, Riverside, CA, 92521, USA; Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Raz Zarivach
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel
| | - Michael E Adams
- Graduate Program in Biochemistry and Molecular Biology, University of California, Riverside, CA, 92521, USA; Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA; Department of Entomology, University of California, Riverside, CA, 92521, USA
| | - Frederic Libersat
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva, 84105, Israel.
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14
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Levels of Par-1 kinase determine the localization of Bruchpilot at the Drosophila neuromuscular junction synapses. Sci Rep 2018; 8:16099. [PMID: 30382129 PMCID: PMC6208417 DOI: 10.1038/s41598-018-34250-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 09/21/2018] [Indexed: 12/11/2022] Open
Abstract
Functional synaptic networks are compromised in many neurodevelopmental and neurodegenerative diseases. While the mechanisms of axonal transport and localization of synaptic vesicles and mitochondria are relatively well studied, little is known about the mechanisms that regulate the localization of proteins that localize to active zones. Recent finding suggests that mechanisms involved in transporting proteins destined to active zones are distinct from those that transport synaptic vesicles or mitochondria. Here we report that localization of BRP-an essential active zone scaffolding protein in Drosophila, depends on the precise balance of neuronal Par-1 kinase. Disruption of Par-1 levels leads to excess accumulation of BRP in axons at the expense of BRP at active zones. Temporal analyses demonstrate that accumulation of BRP within axons precedes the loss of synaptic function and its depletion from the active zones. Mechanistically, we find that Par-1 co-localizes with BRP and is present in the same molecular complex, raising the possibility of a novel mechanism for selective localization of BRP-like active zone scaffolding proteins. Taken together, these data suggest an intriguing possibility that mislocalization of active zone proteins like BRP might be one of the earliest signs of synapse perturbation and perhaps, synaptic networks that precede many neurological disorders.
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15
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Arasaki K, Nagashima H, Kurosawa Y, Kimura H, Nishida N, Dohmae N, Yamamoto A, Yanagi S, Wakana Y, Inoue H, Tagaya M. MAP1B-LC1 prevents autophagosome formation by linking syntaxin 17 to microtubules. EMBO Rep 2018; 19:embr.201745584. [PMID: 29925525 DOI: 10.15252/embr.201745584] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 11/09/2022] Open
Abstract
In fed cells, syntaxin 17 (Stx17) is associated with microtubules at the endoplasmic reticulum-mitochondria interface and promotes mitochondrial fission by determining the localization and function of the mitochondrial fission factor Drp1. Upon starvation, Stx17 dissociates from microtubules and Drp1, and binds to Atg14L, a subunit of the phosphatidylinositol 3-kinase complex, to facilitate phosphatidylinositol 3-phosphate production and thereby autophagosome formation, but the mechanism underlying this phenomenon remains unknown. Here we identify MAP1B-LC1 (microtubule-associated protein 1B-light chain 1) as a critical regulator of Stx17 function. Depletion of MAP1B-LC1 causes Stx17-dependent autophagosome accumulation even under nutrient-rich conditions, whereas its overexpression blocks starvation-induced autophagosome formation. MAP1B-LC1 links microtubules and Stx17 in fed cells, and starvation causes the dephosphorylation of MAP1B-LC1 at Thr217, allowing Stx17 to dissociate from MAP1B-LC1 and bind to Atg14L. Our results reveal the mechanism by which Stx17 changes its binding partners in response to nutrient status.
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Affiliation(s)
- Kohei Arasaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Haruki Nagashima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Yuri Kurosawa
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hana Kimura
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Naoki Nishida
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan
| | - Akitsugu Yamamoto
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga, Japan
| | - Shigeru Yanagi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Yuichi Wakana
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hiroki Inoue
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Mitsuo Tagaya
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
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16
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Smith GM, Gallo G. The role of mitochondria in axon development and regeneration. Dev Neurobiol 2017; 78:221-237. [PMID: 29030922 DOI: 10.1002/dneu.22546] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/12/2017] [Accepted: 10/08/2017] [Indexed: 12/26/2022]
Abstract
Mitochondria are dynamic organelles that undergo transport, fission, and fusion. The three main functions of mitochondria are to generate ATP, buffer cytosolic calcium, and generate reactive oxygen species. A large body of evidence indicates that mitochondria are either primary targets for neurological disease states and nervous system injury, or are major contributors to the ensuing pathologies. However, the roles of mitochondria in the development and regeneration of axons have just begun to be elucidated. Advances in the understanding of the functional roles of mitochondria in neurons had been largely impeded by insufficient knowledge regarding the molecular mechanisms that regulate mitochondrial transport, stalling, fission/fusion, and a paucity of approaches to image and analyze mitochondria in living axons at the level of the single mitochondrion. However, technical advances in the imaging and analysis of mitochondria in living neurons and significant insights into the mechanisms that regulate mitochondrial dynamics have allowed the field to advance. Mitochondria have now been attributed important roles in the mechanism of axon extension, regeneration, and axon branching. The availability of new experimental tools is expected to rapidly increase our understanding of the functions of axonal mitochondria during both development and later regenerative attempts. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 221-237, 2018.
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Affiliation(s)
- George M Smith
- Department of Neuroscience, Temple University, Lewis Katz School of Medicine, Philadelphia, Pennsylvania, 19140.,Shriners Hospitals Pediatric Research Center, Temple University, Lewis Katz School of Medicine, Philadelphia, Pennsylvania, 19140
| | - Gianluca Gallo
- Department of Anatomy and Cell Biology, Temple University, Lewis Katz School of Medicine, Philadelphia, Pennsylvania, 19140.,Shriners Hospitals Pediatric Research Center, Temple University, Lewis Katz School of Medicine, Philadelphia, Pennsylvania, 19140
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17
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De Vos KJ, Hafezparast M. Neurobiology of axonal transport defects in motor neuron diseases: Opportunities for translational research? Neurobiol Dis 2017; 105:283-299. [PMID: 28235672 PMCID: PMC5536153 DOI: 10.1016/j.nbd.2017.02.004] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/26/2017] [Accepted: 02/20/2017] [Indexed: 12/12/2022] Open
Abstract
Intracellular trafficking of cargoes is an essential process to maintain the structure and function of all mammalian cell types, but especially of neurons because of their extreme axon/dendrite polarisation. Axonal transport mediates the movement of cargoes such as proteins, mRNA, lipids, membrane-bound vesicles and organelles that are mostly synthesised in the cell body and in doing so is responsible for their correct spatiotemporal distribution in the axon, for example at specialised sites such as nodes of Ranvier and synaptic terminals. In addition, axonal transport maintains the essential long-distance communication between the cell body and synaptic terminals that allows neurons to react to their surroundings via trafficking of for example signalling endosomes. Axonal transport defects are a common observation in a variety of neurodegenerative diseases, and mutations in components of the axonal transport machinery have unequivocally shown that impaired axonal transport can cause neurodegeneration (reviewed in El-Kadi et al., 2007, De Vos et al., 2008; Millecamps and Julien, 2013). Here we review our current understanding of axonal transport defects and the role they play in motor neuron diseases (MNDs) with a specific focus on the most common form of MND, amyotrophic lateral sclerosis (ALS).
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Affiliation(s)
- Kurt J De Vos
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK.
| | - Majid Hafezparast
- Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
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18
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Reduced Expression of Foxp1 as a Contributing Factor in Huntington's Disease. J Neurosci 2017; 37:6575-6587. [PMID: 28550168 DOI: 10.1523/jneurosci.3612-16.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 05/08/2017] [Accepted: 05/11/2017] [Indexed: 12/31/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disease caused by a polyglutamine expansion in the huntington protein (htt). The neuropathological hallmark of HD is the loss of neurons in the striatum and, to a lesser extent, in the cortex. Foxp1 is a member of the Forkhead family of transcription factors expressed selectively in the striatum and the cortex. In the brain, three major Foxp1 isoforms are expressed: isoform-A (∼90 kDa), isoform-D (∼70 kDa), and isoform-C (∼50 kDa). We find that expression of Foxp1 isoform-A and -D is selectively reduced in the striatum and cortex of R6/2 HD mice as well as in the striatum of HD patients. Furthermore, expression of mutant htt in neurons results in the downregulation of Foxp1 Elevating expression of isoform-A or -D protects cortical neurons from death caused by the expression of mutant htt On the other hand, knockdown of Foxp1 promotes death in otherwise healthy neurons. Neuroprotection by Foxp1 is likely to be mediated by the transcriptional stimulation of the cell-cycle inhibitory protein p21Waf1/Cip1 Consistently, Foxp1 activates transcription of the p21Waf1/Cip1 gene promoter, and overexpression of Foxp1 in neurons results in the elevation of p21 expression. Moreover, knocking down of p21Waf1/Cip1 blocks the ability of Foxp1 to protect neurons from mut-Htt-induced neurotoxicity. We propose that the selective vulnerability of neurons of the striatum and cortex in HD is related to the loss of expression of Foxp1, a protein that is highly expressed in these neurons and required for their survival.SIGNIFICANCE STATEMENT Although the mutant huntingtin gene is expressed widely, neurons of the striatum and cortex are selectively affected in Huntington's disease (HD). Our results suggest that this selectivity is attributable to the reduced expression of Foxp1, a protein expressed selectively in striatal and cortical neurons that plays a neuroprotective role in these cells. We show that protection by Foxp1 involves stimulation of the p21Waf1/Cip1 (Cdkn1a) gene. Although three major Foxp1 isoforms (A, C, and D) are expressed in the brain, only isoform-A has been studied in the nervous system. We show that isoform-D is also expressed selectively, neuroprotective and downregulated in HD mice and patients. Our results suggest that Foxp1 might be an attractive therapeutic target for HD.
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19
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Sunderhaus ER, Kretzschmar D. Mass Histology to Quantify Neurodegeneration in Drosophila. J Vis Exp 2016. [PMID: 28060320 DOI: 10.3791/54809] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Progressive neurodegenerative diseases like Alzheimer's disease (AD) or Parkinson's disease (PD) are an increasing threat to human health worldwide. Although mammalian models have provided important insights into the underlying mechanisms of pathogenicity, the complexity of mammalian systems together with their high costs are limiting their use. Therefore, the simple but well-established Drosophila model-system provides an alternative for investigating the molecular pathways that are affected in these diseases. Besides behavioral deficits, neurodegenerative diseases are characterized by histological phenotypes such as neuronal death and axonopathy. To quantify neuronal degeneration and to determine how it is affected by genetic and environmental factors, we use a histological approach that is based on measuring the vacuoles in adult fly brains. To minimize the effects of systematic error and to directly compare sections from control and experimental flies in one preparation, we use the 'collar' method for paraffin sections. Neurodegeneration is then assessed by measuring the size and/or number of vacuoles that have developed in the fly brain. This can either be done by focusing on a specific region of interest or by analyzing the entire brain by obtaining serial sections that span the complete head. Therefore, this method allows one to measure not only severe degeneration but also relatively mild phenotypes that are only detectable in a few sections, as occurs during normal aging.
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Affiliation(s)
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University;
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20
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Bodaleo FJ, Gonzalez-Billault C. The Presynaptic Microtubule Cytoskeleton in Physiological and Pathological Conditions: Lessons from Drosophila Fragile X Syndrome and Hereditary Spastic Paraplegias. Front Mol Neurosci 2016; 9:60. [PMID: 27504085 PMCID: PMC4958632 DOI: 10.3389/fnmol.2016.00060] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/11/2016] [Indexed: 11/21/2022] Open
Abstract
The capacity of the nervous system to generate neuronal networks relies on the establishment and maintenance of synaptic contacts. Synapses are composed of functionally different presynaptic and postsynaptic compartments. An appropriate synaptic architecture is required to provide the structural basis that supports synaptic transmission, a process involving changes in cytoskeletal dynamics. Actin microfilaments are the main cytoskeletal components present at both presynaptic and postsynaptic terminals in glutamatergic synapses. However, in the last few years it has been demonstrated that microtubules (MTs) transiently invade dendritic spines, promoting their maturation. Nevertheless, the presence and functions of MTs at the presynaptic site are still a matter of debate. Early electron microscopy (EM) studies revealed that MTs are present in the presynaptic terminals of the central nervous system (CNS) where they interact with synaptic vesicles (SVs) and reach the active zone. These observations have been reproduced by several EM protocols; however, there is empirical heterogeneity in detecting presynaptic MTs, since they appear to be both labile and unstable. Moreover, increasing evidence derived from studies in the fruit fly neuromuscular junction proposes different roles for MTs in regulating presynaptic function in physiological and pathological conditions. In this review, we summarize the main findings that support the presence and roles of MTs at presynaptic terminals, integrating descriptive and biochemical analyses, and studies performed in invertebrate genetic models.
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Affiliation(s)
- Felipe J Bodaleo
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile; Center for Geroscience, Brain Health and Metabolism (GERO)Santiago, Chile
| | - Christian Gonzalez-Billault
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile; Center for Geroscience, Brain Health and Metabolism (GERO)Santiago, Chile; The Buck Institute for Research on Aging, NovatoCA, USA
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21
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Mino RE, Rogers SL, Risinger AL, Rohena C, Banerjee S, Bhat MA. Drosophila Ringmaker regulates microtubule stabilization and axonal extension during embryonic development. J Cell Sci 2016; 129:3282-94. [PMID: 27422099 DOI: 10.1242/jcs.187294] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 07/13/2016] [Indexed: 11/20/2022] Open
Abstract
Axonal growth and targeting are fundamental to the organization of the nervous system, and require active engagement of the cytoskeleton. Polymerization and stabilization of axonal microtubules is central to axonal growth and maturation of neuronal connectivity. Studies have suggested that members of the tubulin polymerization promoting protein (TPPP, also known as P25α) family are involved in cellular process extension. However, no in vivo knockout data exists regarding its role in axonal growth during development. Here, we report the characterization of Ringmaker (Ringer; CG45057), the only Drosophila homolog of long p25α proteins. Immunohistochemical analyses indicate that Ringer expression is dynamically regulated in the embryonic central nervous system (CNS). ringer-null mutants show cell misplacement, and errors in axonal extension and targeting. Ultrastructural examination of ringer mutants revealed defective microtubule morphology and organization. Primary neuronal cultures of ringer mutants exhibit defective axonal extension, and Ringer expression in cells induced microtubule stabilization and bundling into rings. In vitro assays showed that Ringer directly affects tubulin, and promotes microtubule bundling and polymerization. Together, our studies uncover an essential function of Ringer in axonal extension and targeting through proper microtubule organization.
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Affiliation(s)
- Rosa E Mino
- Department of Physiology, University of Texas School of Medicine, Health Science Center, San Antonio, TX 78229, USA
| | - Stephen L Rogers
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - April L Risinger
- Department of Pharmacology, University of Texas School of Medicine, Health Science Center, San Antonio, TX 78229, USA
| | - Cristina Rohena
- Department of Pharmacology, University of Texas School of Medicine, Health Science Center, San Antonio, TX 78229, USA Department of Medicine, University of California, San Diego, CA 92093, USA
| | - Swati Banerjee
- Department of Physiology, University of Texas School of Medicine, Health Science Center, San Antonio, TX 78229, USA
| | - Manzoor A Bhat
- Department of Physiology, University of Texas School of Medicine, Health Science Center, San Antonio, TX 78229, USA
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22
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Eira J, Silva CS, Sousa MM, Liz MA. The cytoskeleton as a novel therapeutic target for old neurodegenerative disorders. Prog Neurobiol 2016; 141:61-82. [PMID: 27095262 DOI: 10.1016/j.pneurobio.2016.04.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 04/13/2016] [Accepted: 04/13/2016] [Indexed: 12/12/2022]
Abstract
Cytoskeleton defects, including alterations in microtubule stability, in axonal transport as well as in actin dynamics, have been characterized in several unrelated neurodegenerative conditions. These observations suggest that defects of cytoskeleton organization may be a common feature contributing to neurodegeneration. In line with this hypothesis, drugs targeting the cytoskeleton are currently being tested in animal models and in human clinical trials, showing promising effects. Drugs that modulate microtubule stability, inhibitors of posttranslational modifications of cytoskeletal components, specifically compounds affecting the levels of tubulin acetylation, and compounds targeting signaling molecules which regulate cytoskeleton dynamics, constitute the mostly addressed therapeutic interventions aiming at preventing cytoskeleton damage in neurodegenerative disorders. In this review, we will discuss in a critical perspective the current knowledge on cytoskeleton damage pathways as well as therapeutic strategies designed to revert cytoskeleton-related defects mainly focusing on the following neurodegenerative disorders: Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Amyotrophic Lateral Sclerosis and Charcot-Marie-Tooth Disease.
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Affiliation(s)
- Jessica Eira
- Neurodegeneration Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200 Porto, Portugal
| | - Catarina Santos Silva
- Neurodegeneration Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200 Porto, Portugal
| | - Mónica Mendes Sousa
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200 Porto, Portugal; Nerve Regeneration Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200 Porto, Portugal
| | - Márcia Almeida Liz
- Neurodegeneration Group, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200 Porto, Portugal.
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23
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Burnouf S, Grönke S, Augustin H, Dols J, Gorsky MK, Werner J, Kerr F, Alic N, Martinez P, Partridge L. Deletion of endogenous Tau proteins is not detrimental in Drosophila. Sci Rep 2016; 6:23102. [PMID: 26976084 PMCID: PMC4792132 DOI: 10.1038/srep23102] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 02/26/2016] [Indexed: 01/06/2023] Open
Abstract
Human Tau (hTau) is a highly soluble and natively unfolded protein that binds to microtubules within neurons. Its dysfunction and aggregation into insoluble paired helical filaments is involved in the pathogenesis of Alzheimer’s disease (AD), constituting, together with accumulated β-amyloid (Aβ) peptides, a hallmark of the disease. Deciphering both the loss-of-function and toxic gain-of-function of hTau proteins is crucial to further understand the mechanisms leading to neurodegeneration in AD. As the fruit fly Drosophila melanogaster expresses Tau proteins (dTau) that are homologous to hTau, we aimed to better comprehend dTau functions by generating a specific tau knock-out (KO) fly line using homologous recombination. We observed that the specific removal of endogenous dTau proteins did not lead to overt, macroscopic phenotypes in flies. Indeed, survival, climbing ability and neuronal function were unchanged in tau KO flies. In addition, we did not find any overt positive or negative effect of dTau removal on human Aβ-induced toxicity. Altogether, our results indicate that the absence of dTau proteins has no major functional impact on flies, and suggests that our tau KO strain is a relevant model to further investigate the role of dTau proteins in vivo, thereby giving additional insights into hTau functions.
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Affiliation(s)
- Sylvie Burnouf
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany
| | - Sebastian Grönke
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany
| | - Hrvoje Augustin
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Jacqueline Dols
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany
| | - Marianna Karina Gorsky
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany
| | - Jennifer Werner
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany
| | - Fiona Kerr
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Nazif Alic
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Pedro Martinez
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany.,CECAD Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases, 50931 Cologne, Germany.,Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
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Dutta S, Rieche F, Eckl N, Duch C, Kretzschmar D. Glial expression of Swiss cheese (SWS), the Drosophila orthologue of neuropathy target esterase (NTE), is required for neuronal ensheathment and function. Dis Model Mech 2015; 9:283-94. [PMID: 26634819 PMCID: PMC4826977 DOI: 10.1242/dmm.022236] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/26/2015] [Indexed: 01/04/2023] Open
Abstract
Mutations in Drosophila Swiss cheese (SWS) or its vertebrate orthologue neuropathy target esterase (NTE), respectively, cause progressive neuronal degeneration in Drosophila and mice and a complex syndrome in humans that includes mental retardation, spastic paraplegia and blindness. SWS and NTE are widely expressed in neurons but can also be found in glia; however, their function in glia has, until now, remained unknown. We have used a knockdown approach to specifically address SWS function in glia and to probe for resulting neuronal dysfunctions. This revealed that loss of SWS in pseudocartridge glia causes the formation of multi-layered glial whorls in the lamina cortex, the first optic neuropil. This phenotype was rescued by the expression of SWS or NTE, suggesting that the glial function is conserved in the vertebrate protein. SWS was also found to be required for the glial wrapping of neurons by ensheathing glia, and its loss in glia caused axonal damage. We also detected severe locomotion deficits in glial sws-knockdown flies, which occurred as early as 2 days after eclosion and increased further with age. Utilizing the giant fibre system to test for underlying functional neuronal defects showed that the response latency to a stimulus was unchanged in knockdown flies compared to controls, but the reliability with which the neurons responded to increasing frequencies was reduced. This shows that the loss of SWS in glia impairs neuronal function, strongly suggesting that the loss of glial SWS plays an important role in the phenotypes observed in the sws mutant. It is therefore likely that changes in glia also contribute to the pathology observed in humans that carry mutations in NTE.
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Affiliation(s)
- Sudeshna Dutta
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, OR 97239, USA
| | - Franziska Rieche
- Institut für Zoologie III - Neurobiologie, Universität Mainz, Colonel-Kleinmann-Weg 2, Mainz D-55099, Germany
| | - Nina Eckl
- Institut für Zoologie III - Neurobiologie, Universität Mainz, Colonel-Kleinmann-Weg 2, Mainz D-55099, Germany
| | - Carsten Duch
- Institut für Zoologie III - Neurobiologie, Universität Mainz, Colonel-Kleinmann-Weg 2, Mainz D-55099, Germany
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, OR 97239, USA
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25
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Ali Y, Ruan K, Grace Zhai R. Drosophila Models of Tauopathy. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00054-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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26
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Long DM, Blake MR, Dutta S, Holbrook SD, Kotwica-Rolinska J, Kretzschmar D, Giebultowicz JM. Relationships between the circadian system and Alzheimer's disease-like symptoms in Drosophila. PLoS One 2014; 9:e106068. [PMID: 25171136 PMCID: PMC4149435 DOI: 10.1371/journal.pone.0106068] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/28/2014] [Indexed: 12/20/2022] Open
Abstract
Circadian clocks coordinate physiological, neurological, and behavioral functions into circa 24 hour rhythms, and the molecular mechanisms underlying circadian clock oscillations are conserved from Drosophila to humans. Clock oscillations and clock-controlled rhythms are known to dampen during aging; additionally, genetic or environmental clock disruption leads to accelerated aging and increased susceptibility to age-related pathologies. Neurodegenerative diseases, such as Alzheimer's disease (AD), are associated with a decay of circadian rhythms, but it is not clear whether circadian disruption accelerates neuronal and motor decline associated with these diseases. To address this question, we utilized transgenic Drosophila expressing various Amyloid-β (Aβ) peptides, which are prone to form aggregates characteristic of AD pathology in humans. We compared development of AD-like symptoms in adult flies expressing Aβ peptides in the wild type background and in flies with clocks disrupted via a null mutation in the clock gene period (per01). No significant differences were observed in longevity, climbing ability and brain neurodegeneration levels between control and clock-deficient flies, suggesting that loss of clock function does not exacerbate pathogenicity caused by human-derived Aβ peptides in flies. However, AD-like pathologies affected the circadian system in aging flies. We report that rest/activity rhythms were impaired in an age-dependent manner. Flies expressing the highly pathogenic arctic Aβ peptide showed a dramatic degradation of these rhythms in tune with their reduced longevity and impaired climbing ability. At the same time, the central pacemaker remained intact in these flies providing evidence that expression of Aβ peptides causes rhythm degradation downstream from the central clock mechanism.
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Affiliation(s)
- Dani M. Long
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Matthew R. Blake
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Sudeshna Dutta
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Scott D. Holbrook
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Joanna Kotwica-Rolinska
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Jadwiga M. Giebultowicz
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
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27
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A presynaptic role of microtubule-associated protein 1/Futsch in Drosophila: regulation of active zone number and neurotransmitter release. J Neurosci 2014; 34:6759-71. [PMID: 24828631 DOI: 10.1523/jneurosci.4282-13.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Structural microtubule-associated proteins (MAPs), like MAP1, not only control the stability of microtubules, but also interact with postsynaptic proteins in the nervous system. Their presynaptic role has barely been studied. To tackle this question, we used the Drosophila model in which there is only one MAP1 homolog: Futsch, which is expressed at the larval neuromuscular junction, presynaptically only. We show that Futsch regulates neurotransmitter release and active zone density. Importantly, we provide evidence that this role of Futsch is not just the consequence of its microtubule-stabilizing function. Using high-resolution microscopy, we show that Futsch and microtubules are almost systematically present in close proximity to active zones, with Futsch being localized in-between microtubules and active zones. Using proximity ligation assays, we further demonstrate the proximity of Futsch, but not microtubules, to active zone components. Altogether our data are in favor of a model by which Futsch locally stabilizes active zones, by reinforcing their link with the underlying microtubule cytoskeleton.
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28
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Bolkan BJ, Kretzschmar D. Loss of Tau results in defects in photoreceptor development and progressive neuronal degeneration in Drosophila. Dev Neurobiol 2014; 74:1210-25. [PMID: 24909306 DOI: 10.1002/dneu.22199] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 05/28/2014] [Accepted: 06/04/2014] [Indexed: 12/20/2022]
Abstract
Accumulations of Tau, a microtubule-associated protein (MAP), into neurofibrillary tangles is a hallmark of Alzheimer's disease and other tauopathies. However, the mechanisms leading to this pathology are still unclear: the aggregates themselves could be toxic or the sequestration of Tau into tangles might prevent Tau from fulfilling its normal functions, thereby inducing a loss of function defect. Surprisingly, the consequences of losing normal Tau expression in vivo are still not well understood, in part due to the fact that Tau knockout mice show only subtle phenotypes, presumably due to the fact that mammals express several MAPs with partially overlapping functions. In contrast, flies express fewer MAP, with Tau being the only member of the Tau/MAP2/MAP4 family. Therefore, we used Drosophila to address the physiological consequences caused by the loss of Tau. Reducing the levels of fly Tau (dTau) ubiquitously resulted in developmental lethality, whereas deleting Tau specifically in neurons or the eye caused progressive neurodegeneration. Similarly, chromosomal mutations affecting dTau also caused progressive degeneration in both the eye and brain. Although photoreceptor cells initially developed normally in dTau knockdown animals, they subsequently degenerated during late pupal stages whereas weaker dTau alleles caused an age-dependent defect in rhabdomere structure. Expression of wild type human Tau partially rescued the neurodegenerative phenotype caused by the loss of endogenous dTau, suggesting that the functions of Tau proteins are functionally conserved from flies to humans.
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Affiliation(s)
- Bonnie J Bolkan
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon, 97239
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29
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Sharma A, Khan AN, Subrahmanyam S, Raman A, Taylor GS, Fletcher MJ. Salivary proteins of plant-feeding hemipteroids - implication in phytophagy. BULLETIN OF ENTOMOLOGICAL RESEARCH 2014; 104:117-36. [PMID: 24280006 DOI: 10.1017/s0007485313000618] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. Saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. A plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. Hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump feeding and cell-rupture feeding. The last strategy also includes several different tactics such as lacerate-and-flush, lacerate-and-sip and macerate-and-flush. Understanding hemipteroid feeding mechanisms is critical, since feeding behaviour directs salivary composition. Saliva of the Heteroptera that are specialized as fruit and seed feeders, includes cell-degrading enzymes, auchenorrhynchan salivary composition also predominantly consists of cell-degrading enzymes such as amylase and protease, whereas that of the Sternorhyncha includes a variety of allelochemical-detoxifying enzymes. Little is known about the salivary composition of the Thysanoptera. Cell-degrading proteins such as amylase, pectinase, cellulase and pectinesterase enable stylet entry into the plant tissue. In contrast, enzymes such as glutathione peroxidase, laccase and trehalase detoxify plant chemicals, enabling the circumvention of plant-defence mechanisms. Salivary enzymes such as M1-zinc metalloprotease and CLIP-domain serine protease as in Acyrthosiphon pisum (Aphididae), and non-enzymatic proteins such as apolipophorin, ficolin-3-like protein and 'lava-lamp' protein as in Diuraphis noxia (Aphididae) have the capacity to alter host-plant-defence mechanisms. A majority of the hemipteroids feed on phloem, hence Ca++-binding proteins such as C002 protein, calreticulin-like isoform 1 and calmodulin (critical for preventing sieve-plate occlusion) are increasingly being recognized in hemipteroid-plant interactions. Determination of a staggering variety of proteins shows the complexity of hemipteroid saliva: effector proteins localized in hemipteran saliva suggest a similarity to the physiology of pathogen-plant interactions.
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Affiliation(s)
- A Sharma
- School of Agricultural & Wine Sciences, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia
| | - A N Khan
- School of Agricultural & Wine Sciences, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia
| | - S Subrahmanyam
- School of Agricultural & Wine Sciences, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia
| | - A Raman
- School of Agricultural & Wine Sciences, Charles Sturt University, PO Box 883, Orange, NSW 2800, Australia
| | - G S Taylor
- Australian Centre for Evolutionary Biology and Biodiversity, and School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Australia
| | - M J Fletcher
- Orange Agricultural Institute, NSW Department of Primary Industries, Forest Road, Orange, NSW 2800, Australia
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30
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Kruer MC, Jepperson T, Dutta S, Steiner RD, Cottenie E, Sanford L, Merkens M, Russman BS, Blasco PA, Fan G, Pollock J, Green S, Woltjer RL, Mooney C, Kretzschmar D, Paisán-Ruiz C, Houlden H. Mutations in γ adducin are associated with inherited cerebral palsy. Ann Neurol 2014; 74:805-14. [PMID: 23836506 PMCID: PMC3952628 DOI: 10.1002/ana.23971] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/27/2013] [Accepted: 06/07/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Cerebral palsy is estimated to affect nearly 1 in 500 children, and although prenatal and perinatal contributors have been well characterized, at least 20% of cases are believed to be inherited. Previous studies have identified mutations in the actin-capping protein KANK1 and the adaptor protein-4 complex in forms of inherited cerebral palsy, suggesting a role for components of the dynamic cytoskeleton in the genesis of the disease. METHODS We studied a multiplex consanguineous Jordanian family by homozygosity mapping and exome sequencing, then used patient-derived fibroblasts to examine functional consequences of the mutation we identified in vitro. We subsequently studied the effects of adducin loss of function in Drosophila. RESULTS We identified a homozygous c.1100G>A (p.G367D) mutation in ADD3, encoding gamma adducin in all affected members of the index family. Follow-up experiments in patient fibroblasts found that the p.G367D mutation, which occurs within the putative oligomerization critical region, impairs the ability of gamma adducin to associate with the alpha subunit. This mutation impairs the normal actin-capping function of adducin, leading to both abnormal proliferation and migration in cultured patient fibroblasts. Loss of function studies of the Drosophila adducin ortholog hts confirmed a critical role for adducin in locomotion. INTERPRETATION Although likely a rare cause of cerebral palsy, our findings indicate a critical role for adducins in regulating the activity of the actin cytoskeleton, suggesting that impaired adducin function may lead to neuromotor impairment and further implicating abnormalities of the dynamic cytoskeleton as a pathogenic mechanism contributing to cerebral palsy.
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31
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Cook M, Bolkan BJ, Kretzschmar D. Increased actin polymerization and stabilization interferes with neuronal function and survival in the AMPKγ mutant Loechrig. PLoS One 2014; 9:e89847. [PMID: 24587072 PMCID: PMC3934941 DOI: 10.1371/journal.pone.0089847] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 01/27/2014] [Indexed: 11/18/2022] Open
Abstract
loechrig (loe) mutant flies are characterized by progressive neuronal degeneration, behavioral deficits, and early death. The mutation is due to a P-element insertion in the gene for the γ-subunit of the trimeric AMP-activated protein kinase (AMPK) complex, whereby the insertion affects only one of several alternative transcripts encoding a unique neuronal isoform. AMPK is a cellular energy sensor that regulates a plethora of signaling pathways, including cholesterol and isoprenoid synthesis via its downstream target hydroxy-methylglutaryl (HMG)-CoA reductase. We recently showed that loe interferes with isoprenoid synthesis and increases the prenylation and thereby activation of RhoA. During development, RhoA plays an important role in neuronal outgrowth by activating a signaling cascade that regulates actin dynamics. Here we show that the effect of loe/AMPKγ on RhoA prenylation leads to a hyperactivation of this signaling pathway, causing increased phosphorylation of the actin depolymerizating factor cofilin and accumulation of filamentous actin. Furthermore, our results show that the resulting cytoskeletal changes in loe interfere with neuronal growth and disrupt axonal integrity. Surprisingly, these phenotypes were enhanced by expressing the Slingshot (SSH) phosphatase, which during development promotes actin depolymerization by dephosphorylating cofilin. However, our studies suggest that in the adult SSH promotes actin polymerization, supporting in vitro studies using human SSH1 that suggested that SSH can also stabilize and bundle filamentous actin. Together with the observed increase in SSH levels in the loe mutant, our experiments suggest that in mature neurons SSH may function as a stabilization factor for filamentous actin instead of promoting actin depolymerization.
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Affiliation(s)
- Mandy Cook
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, Oregon, United States of America
| | - Bonnie J. Bolkan
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, Oregon, United States of America
| | - Doris Kretzschmar
- Oregon Institute of Occupational Health Sciences, Oregon Health & Sciences University, Portland, Oregon, United States of America
- * E-mail:
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32
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Chan SL, Angeles DC, Tan EK. Targeting leucine-rich repeat kinase 2 in Parkinson's disease. Expert Opin Ther Targets 2013; 17:1471-82. [DOI: 10.1517/14728222.2013.842978] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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33
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Neurodegeneration caused by polyglutamine expansion is regulated by P-glycoprotein in Drosophila melanogaster. Genetics 2013; 195:857-70. [PMID: 24037265 DOI: 10.1534/genetics.113.155077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Trinucleotide CAG repeat disorders are caused by expansion of polyglutamine (polyQ) domains in certain proteins leading to fatal neurodegenerative disorders and are characterized by accumulation of inclusion bodies in the neurons. Clearance of these inclusion bodies holds the key to improve the disease phenotypes, which affects basic cellular processes such as transcription, protein degradation and cell signaling. In the present study, we show that P-glycoprotein (P-gp), originally identified as a causative agent of multidrug-resistant cancer cells, plays an important role in ameliorating the disease phenotype. Using a Drosophila transgenic strain that expresses a stretch of 127 glutamine repeats, we demonstrate that enhancing P-gp levels reduces eye degeneration caused by expression of polyQ, whereas reducing it increases the severity of the disease. Increase in polyQ inclusion bodies represses the expression of mdr genes, suggesting a functional link between P-gp and polyQ. P-gp up-regulation restores the defects in the actin organization and precise array of the neuronal connections caused by inclusion bodies. β-Catenin homolog, Armadillo, also interacts with P-gp and regulates the accumulation of inclusion bodies. These results thus show that P-gp and polyQ interact with each other, and changing P-gp levels can directly affect neurodegeneration.
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Baumgartner R, Stocker H, Hafen E. The RNA-binding proteins FMR1, rasputin and caprin act together with the UBA protein lingerer to restrict tissue growth in Drosophila melanogaster. PLoS Genet 2013; 9:e1003598. [PMID: 23874212 PMCID: PMC3708825 DOI: 10.1371/journal.pgen.1003598] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/15/2013] [Indexed: 12/19/2022] Open
Abstract
Appropriate expression of growth-regulatory genes is essential to ensure normal animal development and to prevent diseases like cancer. Gene regulation at the levels of transcription and translational initiation mediated by the Hippo and Insulin signaling pathways and by the TORC1 complex, respectively, has been well documented. Whether translational control mediated by RNA-binding proteins contributes to the regulation of cellular growth is less clear. Here, we identify Lingerer (Lig), an UBA domain-containing protein, as growth suppressor that associates with the RNA-binding proteins Fragile X mental retardation protein 1 (FMR1) and Caprin (Capr) and directly interacts with and regulates the RNA-binding protein Rasputin (Rin) in Drosophila melanogaster. lig mutant organs overgrow due to increased proliferation, and a reporter for the JAK/STAT signaling pathway is upregulated in a lig mutant situation. rin, Capr or FMR1 in combination as double mutants, but not the respective single mutants, display lig like phenotypes, implicating a redundant function of Rin, Capr and FMR1 in growth control in epithelial tissues. Thus, Lig regulates cell proliferation during development in concert with Rin, Capr and FMR1. Animal growth is orchestrated by controlled expression of growth-regulatory factors. This regulation is achieved at different molecular levels like transcription, translation initiation, and translational regulation. Whereas transcriptional control and translation initiation of growth components have been well studied, the role of translational control in this process is less well understood. Here, we describe Lingerer (Lig), an UBA domain-containing protein, as a new growth suppressor that associates with the three RNA-binding proteins Fragile X mental retardation protein 1 (FMR1), Rasputin (Rin) and Caprin (Capr). Drosophila FMR1, Rin and Capr orthologs are known translational regulators. In lig mutants and in FMR1, Capr and rin in combination as double mutants, organ size is increased due to excess proliferation. These data unveil a growth-regulatory function of Lig, and a redundant function of the RNA-binding proteins FMR1, Capr and Rin. Our findings demonstrate the involvement of mRNA-binding proteins in epithelial growth control and may also contribute to a better molecular understanding of the Fragile X mental retardation syndrome.
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Affiliation(s)
- Roland Baumgartner
- Institute of Molecular Systems Biology, ETH Zürich, Wolfgang-Pauli-Strasse, Zürich, Switzerland
| | - Hugo Stocker
- Institute of Molecular Systems Biology, ETH Zürich, Wolfgang-Pauli-Strasse, Zürich, Switzerland
| | - Ernst Hafen
- Institute of Molecular Systems Biology, ETH Zürich, Wolfgang-Pauli-Strasse, Zürich, Switzerland
- * E-mail:
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35
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Nahm M, Lee MJ, Parkinson W, Lee M, Kim H, Kim YJ, Kim S, Cho YS, Min BM, Bae YC, Broadie K, Lee S. Spartin regulates synaptic growth and neuronal survival by inhibiting BMP-mediated microtubule stabilization. Neuron 2013; 77:680-95. [PMID: 23439121 DOI: 10.1016/j.neuron.2012.12.015] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2012] [Indexed: 01/06/2023]
Abstract
Troyer syndrome is a hereditary spastic paraplegia caused by human spartin (SPG20) gene mutations. We have generated a Drosophila disease model showing that Spartin functions presynaptically with endocytic adaptor Eps15 to regulate synaptic growth and function. Spartin inhibits bone morphogenetic protein (BMP) signaling by promoting endocytic degradation of BMP receptor wishful thinking (Wit). Drosophila fragile X mental retardation protein (dFMRP) and Futsch/MAP1B are downstream effectors of Spartin and BMP signaling in regulating microtubule stability and synaptic growth. Loss of Spartin or elevation of BMP signaling induces age-dependent progressive defects resembling hereditary spastic paraplegias, including motor dysfunction and brain neurodegeneration. Null spartin phenotypes are prevented by administration of the microtubule-destabilizing drug vinblastine. Together, these results demonstrate that Spartin regulates both synaptic development and neuronal survival by controlling microtubule stability via the BMP-dFMRP-Futsch pathway, suggesting that impaired regulation of microtubule stability is a core pathogenic component in Troyer syndrome.
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Affiliation(s)
- Minyeop Nahm
- Department of Cell and Developmental Biology, Dental Research Institute, Seoul National University, Seoul 110-749, Republic of Korea
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Momota R, Narasaki M, Komiyama T, Naito I, Ninomiya Y, Ohtsuka A. Drosophila type XV/XVIII collagen mutants manifest integrin mediated mitochondrial dysfunction, which is improved by cyclosporin A and losartan. Int J Biochem Cell Biol 2013; 45:1003-11. [PMID: 23454281 DOI: 10.1016/j.biocel.2013.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 01/06/2013] [Accepted: 02/04/2013] [Indexed: 02/07/2023]
Abstract
Vertebrate collagen types XV and XVIII are broadly distributed basement membrane components, classified into a structurally distinct subgroup called "multiplexin collagens". Mutations in mammalian multiplexins are identified in some degenerative diseases such as Knobloch syndrome 1 (KNO1) or skeletal/cardiac myopathies, however, these progressive properties have not been elucidated. Here we investigated Drosophila mutants of Multiplexin (Mp), the only orthologue of vertebrate collagen types XV and XVIII, to understand the pathogenesis of multiplexin-related diseases. The mp mutants exhibited morphological changes in cardiomyocytes and progressive dysfunction of the skeletal muscles, reminiscent phenotypes observed in Col15a1-null mice. Ultrastructural analysis revealed morphologically altered mitochondria in mutants' indirect flight muscles (IFMs), resulting in severely attenuated ATP production and enhanced reactive oxygen species (ROS) production. In addition, mutants' IFMs exhibited diminished βPS integrin clustering and abolished focal adhesion kinase (FAK) phosphorylation. Furthermore, mutants' defective IFMs are improved by the administrations of cyclosporin A, an inhibitor against mitochondrial permeability transition pore (mPTP) opening or losartan, an angiotensin II type 1 receptor (AT1R) blocker. Thus, our results suggest that Mp modulates mPTP opening and AT1R activity through its binding to integrin and that lack of Mp causes unregulated mPTP opening and AT1R activity, leading to mitochondrial dysfunctions. Hence, our results provide new insights towards the roles of multiplexin collagens in mitochondrial homeostasis and may serve as pharmacological evidences for the potential use of cyclosporin A or losartan for the therapeutic strategies.
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Affiliation(s)
- Ryusuke Momota
- Department of Human Morphology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1, Shikata-cho, Kita, Okayama 7008558, Japan.
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37
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β-secretase cleavage of the fly amyloid precursor protein is required for glial survival. J Neurosci 2013; 32:16181-92. [PMID: 23152602 DOI: 10.1523/jneurosci.0228-12.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
β-secretase (or BACE1) is the key enzyme in the production of β-amyloid (Aβ), which accumulates in the senile plaques characteristic for Alzheimer's disease. Consequently, the lack of BACE1 prevents β-processing of the amyloid precursor protein and Aβ production, which made it a promising target for drug development. However, the loss of BACE1 is also detrimental, leading to myelination defects and altered neuronal activity, functions that have been associated with the cleavage of Neuregulin and a voltage-gated sodium channel subunit. Here we show that the Drosophila ortholog of BACE, dBACE, is required for glial survival. Cell-specific knockdown experiments reveal that this is a non-cell autonomous function, as a knockdown of dBACE in photoreceptor neurons leads to progressive degeneration of glia in their target zone, the lamina. Interestingly, this phenotype is suppressed by the loss of the fly amyloid precursor protein (APPL), whereas a secretion-deficient form of APPL enhances the degeneration. This shows that full-length APPL in neurons promotes the death of neighboring glial cells and that β-processing of APPL is needed to prevent glial death. These results therefore not only demonstrate a novel function for an APP protein in glia, but they also show this function specifically requires regulation by β-cleavage.
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38
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Nfonsam LE, Cano C, Mudge J, Schilkey FD, Curtiss J. Analysis of the transcriptomes downstream of Eyeless and the Hedgehog, Decapentaplegic and Notch signaling pathways in Drosophila melanogaster. PLoS One 2012; 7:e44583. [PMID: 22952997 PMCID: PMC3432130 DOI: 10.1371/journal.pone.0044583] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 08/09/2012] [Indexed: 01/22/2023] Open
Abstract
Tissue-specific transcription factors are thought to cooperate with signaling pathways to promote patterned tissue specification, in part by co-regulating transcription. The Drosophila melanogaster Pax6 homolog Eyeless forms a complex, incompletely understood regulatory network with the Hedgehog, Decapentaplegic and Notch signaling pathways to control eye-specific gene expression. We report a combinatorial approach, including mRNAseq and microarray analyses, to identify targets co-regulated by Eyeless and Hedgehog, Decapentaplegic or Notch. Multiple analyses suggest that the transcriptomes resulting from co-misexpression of Eyeless+signaling factors provide a more complete picture of eye development compared to previous efforts involving Eyeless alone: (1) Principal components analysis and two-way hierarchical clustering revealed that the Eyeless+signaling factor transcriptomes are closer to the eye control transcriptome than when Eyeless is misexpressed alone; (2) more genes are upregulated at least three-fold in response to Eyeless+signaling factors compared to Eyeless alone; (3) based on gene ontology analysis, the genes upregulated in response to Eyeless+signaling factors had a greater diversity of functions compared to Eyeless alone. Through a secondary screen that utilized RNA interference, we show that the predicted gene CG4721 has a role in eye development. CG4721 encodes a neprilysin family metalloprotease that is highly up-regulated in response to Eyeless+Notch, confirming the validity of our approach. Given the similarity between D. melanogaster and vertebrate eye development, the large number of novel genes identified as potential targets of Ey+signaling factors will provide novel insights to our understanding of eye development in D. melanogaster and humans.
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Affiliation(s)
- Landry E. Nfonsam
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Carlos Cano
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Joann Mudge
- National Center for Genome Resources, Santa Fe, New Mexico, United States of America
| | - Faye D. Schilkey
- National Center for Genome Resources, Santa Fe, New Mexico, United States of America
| | - Jennifer Curtiss
- Department of Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
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Xu P, Tan H, Duong DM, Yang Y, Kupsco J, Moberg KH, Li H, Jin P, Peng J. Stable isotope labeling with amino acids in Drosophila for quantifying proteins and modifications. J Proteome Res 2012; 11:4403-12. [PMID: 22830426 DOI: 10.1021/pr300613c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Drosophila melanogaster is a common animal model for genetics studies, and quantitative proteomics studies of the fly are emerging. Here, we present in detail the development of a procedure to incorporate stable isotope-labeled amino acids into the fly proteome. In the method of stable isotope labeling with amino acids in Drosophila melanogaster (SILAC fly), flies were fed with SILAC-labeled yeast grown with modified media, enabling near complete labeling in a single generation. Biological variation in the proteome among individual flies was evaluated in a series of null experiments. We further applied the SILAC fly method to profile proteins from a model of fragile X syndrome, the most common cause of inherited mental retardation in human. The analysis identified a number of altered proteins in the disease model, including actin-binding protein profilin and microtubulin-associated protein futsch. The change of both proteins was validated by immunoblotting analysis. Moreover, we extended the SILAC fly strategy to study the dynamics of protein ubiquitination during the fly life span (from day 1 to day 30), by measuring the level of ubiquitin along with two major polyubiquitin chains (K48 and K63 linkages). The results show that the abundance of protein ubiquitination and the two major linkages do not change significantly within the measured age range. Together, the data demonstrate the application of the SILAC principle in D. melanogaster, facilitating the integration of powerful fly genomics with emerging proteomics.
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Affiliation(s)
- Ping Xu
- Department of Human Genetics, Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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40
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Drosophila models of tauopathies: what have we learned? Int J Alzheimers Dis 2012; 2012:970980. [PMID: 22701808 PMCID: PMC3373119 DOI: 10.1155/2012/970980] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 04/08/2012] [Indexed: 01/10/2023] Open
Abstract
Aggregates of the microtubule-associated protein Tau are neuropathological hallmark lesions in Alzheimer's disease (AD) and related primary tauopathies. In addition, Tau is genetically implicated in a number of human neurodegenerative disorders including frontotemporal dementia (FTD) and Parkinson's disease (PD). The exact mechanism by which Tau exerts its neurotoxicity is incompletely understood. Here, we give an overview of how studies using the genetic model organism Drosophila over the past decade have contributed to the molecular understanding of Tau neurotoxicity. We compare the different available readouts for Tau neurotoxicity in flies and review the molecular pathways in which Tau has been implicated. Finally, we emphasize that the integration of genome-wide approaches in human or mice with high-throughput genetic validation in Drosophila is a fruitful approach.
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Abstract
The cytoskeleton forms the backbone of neuronal architecture, sustaining its form and size, subcellular compartments and cargo logistics. The synaptic cytoskeleton can be categorized in the microtubule-based core cytoskeleton and the cortical membrane skeleton. While central microtubules form the fundamental basis for the construction of elaborate neuronal processes, including axons and synapses, cortical actin filaments are generally considered to function as mediators of synapse dynamics and plasticity. More recently, the submembranous network of spectrin and ankyrin molecules has been involved in the regulation of synaptic stability and maintenance. Disruption of the synaptic cytoskeleton primarily affects the stability and maturation of synapses but also secondarily disturbs neuronal communication. Consequently, a variety of inherited diseases are accompanied by cytoskeletal malfunctions, including spastic paraplegias, spinocerebellar ataxias, and mental retardation. Since the primary reasons for many of these diseases are still unknown model organisms with a conserved repertoire of cytoskeletal elements help to understand the underlying biological mechanisms. The astonishing technical as well as genetic accessibility of synapses in Drosophila has shown that loss of the cytoskeletal architecture leads to axonal transport defects, synaptic maturation deficits, and retraction of synaptic boutons, before synaptic terminals finally detach from their target cells, suggesting that similar processes could be involved in human neuronal diseases.
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Affiliation(s)
- Bernd Goellner
- Heinrich-Heine-University Düsseldorf, Functional Cell Morphology Lab, Düsseldorf, Germany
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42
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Nicholson SJ, Hartson SD, Puterka GJ. Proteomic analysis of secreted saliva from Russian Wheat Aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat. J Proteomics 2012; 75:2252-68. [DOI: 10.1016/j.jprot.2012.01.031] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/03/2012] [Accepted: 01/27/2012] [Indexed: 01/21/2023]
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43
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Keller LC, Cheng L, Locke CJ, Müller M, Fetter RD, Davis GW. Glial-derived prodegenerative signaling in the Drosophila neuromuscular system. Neuron 2012; 72:760-75. [PMID: 22153373 DOI: 10.1016/j.neuron.2011.09.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2011] [Indexed: 11/15/2022]
Abstract
We provide evidence for a prodegenerative, glial-derived signaling framework in the Drosophila neuromuscular system that includes caspase and mitochondria-dependent signaling. We demonstrate that Drosophila TNF-α (eiger) is expressed in a subset of peripheral glia, and the TNF-α receptor (TNFR), Wengen, is expressed in motoneurons. NMJ degeneration caused by disruption of the spectrin/ankyrin skeleton is suppressed by an eiger mutation or by eiger knockdown within a subset of peripheral glia. Loss of wengen in motoneurons causes a similar suppression providing evidence for glial-derived prodegenerative TNF-α signaling. Neither JNK nor NFκβ is required for prodegenerative signaling. However, we provide evidence for the involvement of both an initiator and effector caspase, Dronc and Dcp-1, and mitochondrial-dependent signaling. Mutations that deplete the axon and nerve terminal of mitochondria suppress degeneration as do mutations in Drosophila Bcl-2 (debcl), a mitochondria-associated protein, and Apaf-1 (dark), which links mitochondrial signaling with caspase activity in other systems.
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Affiliation(s)
- Lani C Keller
- Department of Biochemistry and Biophysics, University of California, San Francisco, 1550 4th Street, Rock Hall 4th Floor North, San Francisco, CA 94143, USA
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Wentzell JS, Bolkan BJ, Carmine-Simmen K, Swanson TL, Musashe DT, Kretzschmar D. Amyloid precursor proteins are protective in Drosophila models of progressive neurodegeneration. Neurobiol Dis 2012; 46:78-87. [PMID: 22266106 DOI: 10.1016/j.nbd.2011.12.047] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 12/06/2011] [Accepted: 12/31/2011] [Indexed: 12/11/2022] Open
Abstract
The processing of Amyloid Precursor Proteins (APPs) results in several fragments, including soluble N-terminal ectodomains (sAPPs) and C-terminal intracellular domains (AICD). sAPPs have been ascribed neurotrophic or neuroprotective functions in cell culture, although β-cleaved sAPPs can have deleterious effects and trigger neuronal cell death. Here we describe a neuroproprotective function of APP and fly APPL (Amyloid Precursor Protein-like) in vivo in several Drosophila mutants with progressive neurodegeneration. We show that expression of the N-terminal ectodomain is sufficient to suppress the progressive degeneration in these mutants and that the secretion of the ectodomain is required for this function. In addition, a protective effect is achieved by expressing kuzbanian (which has α-secretase activity) whereas expression of fly and human BACE aggravates the phenotypes, suggesting that the protective function is specifically mediated by the α-cleaved ectodomain. Furthermore, genetic and molecular studies suggest that the N-terminal fragments interact with full-length APPL activating a downstream signaling pathway via the AICD. Because we show protective effects in mutants that affect different genes (AMP-activated protein kinase, MAP1b, rasGAP), we propose that the protective effect is not due to a genetic interaction between APPL and these genes but a more general aspect of APP proteins. The result that APP proteins and specifically their soluble α-cleaved ectodomains can protect against progressive neurodegeneration in vivo provides support for the hypothesis that a disruption of the physiological function of APP could play a role in the pathogenesis of Alzheimer's Disease.
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Affiliation(s)
- Jill S Wentzell
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Sciences University, Portland, OR 97239, USA
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45
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Abstract
Gene products such as organelles, proteins and RNAs are actively transported to synaptic terminals for the remodeling of pre-existing neuronal connections and formation of new ones. Proteins described as molecular motors mediate this transport and utilize specialized cytoskeletal proteins that function as molecular tracks for the motor based transport of cargos. Molecular motors such as kinesins and dynein's move along microtubule tracks formed by tubulins whereas myosin motors utilize tracks formed by actin. Deficits in active transport of gene products have been implicated in a number of neurological disorders. We describe such disorders collectively as "transportopathies". Here we review current knowledge of critical components of active transport and their relevance to neurodegenerative diseases.
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Cowan CM, Sealey MA, Quraishe S, Targett MT, Marcellus K, Allan D, Mudher A. Modelling tauopathies in Drosophila: insights from the fruit fly. Int J Alzheimers Dis 2011; 2011:598157. [PMID: 22254145 PMCID: PMC3255107 DOI: 10.4061/2011/598157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 11/02/2011] [Indexed: 01/04/2023] Open
Abstract
Drosophila melanogaster is an experimentally tractable model organism that has been used successfully to model aspects of many human neurodegenerative diseases. Drosophila models of tauopathy have provided valuable insights into tau-mediated mechanisms of neuronal dysfunction and death. Here we review the findings from Drosophila models of tauopathy reported over the past ten years and discuss how they have furthered our understanding of the pathogenesis of tauopathies. We also discuss the multitude of technical advantages that Drosophila offers, which make it highly attractive as a model for such studies.
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Affiliation(s)
- Catherine M Cowan
- Centre for Biological Sciences, University of Southampton, University Road, Southampton SO17 3JD, UK
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47
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Krishnan N, Rakshit K, Chow ES, Wentzell JS, Kretzschmar D, Giebultowicz JM. Loss of circadian clock accelerates aging in neurodegeneration-prone mutants. Neurobiol Dis 2011; 45:1129-35. [PMID: 22227001 DOI: 10.1016/j.nbd.2011.12.034] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 11/30/2011] [Accepted: 12/18/2011] [Indexed: 10/14/2022] Open
Abstract
Circadian clocks generate rhythms in molecular, cellular, physiological, and behavioral processes. Recent studies suggest that disruption of the clock mechanism accelerates organismal senescence and age-related pathologies in mammals. Impaired circadian rhythms are observed in many neurological diseases; however, it is not clear whether loss of rhythms is the cause or result of neurodegeneration, or both. To address this important question, we examined the effects of circadian disruption in Drosophila melanogaster mutants that display clock-unrelated neurodegenerative phenotypes. We combined a null mutation in the clock gene period (per(01)) that abolishes circadian rhythms, with a hypomorphic mutation in the carbonyl reductase gene sniffer (sni(1)), which displays oxidative stress induced neurodegeneration. We report that disruption of circadian rhythms in sni(1) mutants significantly reduces their lifespan compared to single mutants. Shortened lifespan in double mutants was coupled with accelerated neuronal degeneration evidenced by vacuolization in the adult brain. In addition, per(01)sni(1) flies showed drastically impaired vertical mobility and increased accumulation of carbonylated proteins compared to age-matched single mutant flies. Loss of per function does not affect sni mRNA expression, suggesting that these genes act via independent pathways producing additive effects. Finally, we show that per(01) mutation accelerates the onset of brain pathologies when combined with neurodegeneration-prone mutation in another gene, swiss cheese (sws(1)), which does not operate through the oxidative stress pathway. Taken together, our data suggest that the period gene may be causally involved in neuroprotective pathways in aging Drosophila.
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Affiliation(s)
- Natraj Krishnan
- Department of Zoology, Oregon State University, Corvallis, OR, USA
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48
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Papanikolopoulou K, Skoulakis EMC. The power and richness of modelling tauopathies in Drosophila. Mol Neurobiol 2011; 44:122-33. [PMID: 21681411 DOI: 10.1007/s12035-011-8193-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 06/06/2011] [Indexed: 02/07/2023]
Abstract
Tauopathies are a group of neurodegenerative disorders characterised by altered levels of phosphorylation or mutations in the neuronal microtubule protein Tau. The heterogeneous pathology of tauopathies suggests differential susceptibility of different neuronal types to wild-type and mutant Tau. The genetic power and facility of the Drosophila model has been instrumental in exploring the molecular aetiologies of tauopathies, identifying additional proteins likely contributing to neuronal dysfunction and toxicity and novel Tau phosphorylations mediating them. Importantly, recent results indicate tissue- and temporal-specific effects on dysfunction and toxicity coupled with differential effects of distinct Tau isoforms within them. Therefore, they reveal an unexpected richness of the Drosophila model that, coupled with its molecular genetic power, will likely play a significant role in our understanding of multiple tauopathies potentially leading to their differential treatment.
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Affiliation(s)
- Katerina Papanikolopoulou
- Institute of Cellular and Developmental Biology, Biomedical Sciences Research Centre Alexander Fleming, Vari 16672, Greece.
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49
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Tien NW, Wu GH, Hsu CC, Chang CY, Wagner OI. Tau/PTL-1 associates with kinesin-3 KIF1A/UNC-104 and affects the motor's motility characteristics in C. elegans neurons. Neurobiol Dis 2011; 43:495-506. [PMID: 21569846 DOI: 10.1016/j.nbd.2011.04.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 04/06/2011] [Accepted: 04/25/2011] [Indexed: 11/29/2022] Open
Abstract
Tauopathies are neurodegenerative diseases based on pathological tau-aggregation including Alzheimer's disease, frontotemporal dementia (FTD) and Pick's disease. In general, cargo (e.g., β-amyloid precursor protein, tau, neurofilaments) accumulation is a commonly observed phenomenon in degenerated neurons. Therefore, it is crucial to investigate the interaction between cargo, microtubule-binding proteins and molecular motors. We report the effect of tau/PTL-1 (protein with tau-like repeats) on the transport characteristics of the major axonal transporter kinesin-3 KIF1A/UNC-104 in the nervous system of Caenorhabditis elegans. Using confocal spinning disk time-lapse imaging we analyzed the motility of UNC-104::mRFP in ptl-1 knockout worms and found that predominantly retrograde moving characteristics are affected (rather than the motor's anterograde displacements). A similar motility pattern was observed for synaptobrevin-1-containing vesicles, a major cargo of UNC-104. Moreover, UNC-104 and PTL-1 colocalize and occasionally co-migrate. We further confirmed physical interactions between PTL-1 and UNC-104 in living animals using the bimolecular fluorescence complementation assay (BiFC) as well as in co-immunoprecipitation experiments. Though this study focuses on PTL-1/UNC-104 interactions, we extended our research on monitoring conventional kinesin-1 (UNC-116) as well as dynein motility pattern and found that in ptl-1 mutants retrograde displacements were also affected for UNC-116, while for dynein, interestingly, its anterograde movements were affected.
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Affiliation(s)
- Nai-Wen Tien
- Institute of Molecular and Cellular Biology and Department of Life Science, National Tsing Hua University, 30013 Hsinchu, Taiwan, ROC
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50
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Godena VK, Romano G, Romano M, Appocher C, Klima R, Buratti E, Baralle FE, Feiguin F. TDP-43 regulates Drosophila neuromuscular junctions growth by modulating Futsch/MAP1B levels and synaptic microtubules organization. PLoS One 2011; 6:e17808. [PMID: 21412434 PMCID: PMC3055892 DOI: 10.1371/journal.pone.0017808] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 02/11/2011] [Indexed: 12/13/2022] Open
Abstract
TDP-43 is an evolutionarily conserved RNA binding protein recently associated with the pathogenesis of different neurological diseases. At the moment, neither its physiological role in vivo nor the mechanisms that may lead to neurodegeneration are well known. Previously, we have shown that TDP-43 mutant flies presented locomotive alterations and structural defects at the neuromuscular junctions. We have now investigated the functional mechanism leading to these phenotypes by screening several factors known to be important for synaptic growth or bouton formation. As a result we found that alterations in the organization of synaptic microtubules correlate with reduced protein levels in the microtubule associated protein futsch/MAP1B. Moreover, we observed that TDP-43 physically interacts with futsch mRNA and that its RNA binding capacity is required to prevent futsch down regulation and synaptic defects.
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Affiliation(s)
- Vinay K. Godena
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Giulia Romano
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Maurizio Romano
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Chiara Appocher
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Raffaella Klima
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Emanuele Buratti
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Francisco E. Baralle
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail: (FEB); (FF)
| | - Fabian Feiguin
- International Center for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail: (FEB); (FF)
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