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Kim HU, Bharda AV, Moon JC, Jeoung D, Chung JM, Jung HS. Microscopic studies on severing properties of actin-binding protein: its potential use in therapeutic treatment of actin-rich inclusions. J Anal Sci Technol 2021. [DOI: 10.1186/s40543-021-00305-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractActin is an important unit of the cytoskeletal system, involved in many cellular processes including cell motility, signaling, and intracellular trafficking. Various studies have been undertaken to understand the regulatory mechanisms pertaining actin functions, especially the ones controlled by actin-binding proteins. However, not much has been explored about the molecular aspects of these proteins implicated in various diseases. In this study, we aimed to demonstrate the molecular properties of gelsolin, an actin-severing protein on the disassembly of the aggregation of actin-rich intracellular inclusions, Hirano body. We observed a decreasing tendency of actin aggregation by co-sedimentation assay and transmission electron microscopy in the presence of gelsolin. Therefore, we provide suggestive evidence for the use of actin-severing protein in novel therapeutic strategies for neurodegenerative conditions.
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Martín‐González J, Montero‐Bullón J, Lacal J. Dictyostelium discoideum as a non-mammalian biomedical model. Microb Biotechnol 2021; 14:111-125. [PMID: 33124755 PMCID: PMC7888446 DOI: 10.1111/1751-7915.13692] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/06/2020] [Accepted: 10/11/2020] [Indexed: 02/06/2023] Open
Abstract
Dictyostelium discoideum is one of eight non-mammalian model organisms recognized by the National Institute of Health for the study of human pathology. The use of this slime mould is possible owing to similarities in cell structure, behaviour and intracellular signalling with mammalian cells. Its haploid set of chromosomes completely sequenced amenable to genetic manipulation, its unique and short life cycle with unicellular and multicellular stages, and phenotypic richness encoding many human orthologues, make Dictyostelium a representative and simple model organism to unveil cellular processes in human disease. Dictyostelium studies within the biomedical field have provided fundamental knowledge in the areas of bacterial infection, immune cell chemotaxis, autophagy/phagocytosis and mitochondrial and neurological disorders. Consequently, Dictyostelium has been used to the development of related pharmacological treatments. Herein, we review the utilization of Dictyostelium as a model organism in biomedicine.
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Affiliation(s)
- Javier Martín‐González
- Molecular Genetics of Human Diseases GroupDepartment of Microbiology and GeneticsFaculty of BiologyUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
| | - Javier‐Fernando Montero‐Bullón
- Metabolic Engineering GroupDepartment of Microbiology and GeneticsUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
| | - Jesus Lacal
- Molecular Genetics of Human Diseases GroupDepartment of Microbiology and GeneticsFaculty of BiologyUniversity of SalamancaCampus Miguel de UnamunoSalamancaE‐37007Spain
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Pathak S, Parkar H, Tripathi S, Kale A. Ofloxacin as a Disruptor of Actin Aggresome "Hirano Bodies": A Potential Repurposed Drug for the Treatment of Neurodegenerative Diseases. Front Aging Neurosci 2020; 12:591579. [PMID: 33132905 PMCID: PMC7573105 DOI: 10.3389/fnagi.2020.591579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/09/2020] [Indexed: 01/27/2023] Open
Abstract
There is a growing number of aging populations that are more prone to the prevalence of neuropathological disorders. Two major diseases that show a late onset of the symptoms include Alzheimer’s disorder (AD) and Parkinson’s disorder (PD), which are causing an unexpected social and economic impact on the families. A large number of researches in the last decade have focused upon the role of amyloid precursor protein, Aβ-plaque, and intraneuronal neurofibrillary tangles (tau-proteins). However, there is very few understanding of actin-associated paracrystalline structures formed in the hippocampus region of the brain and are called Hirano bodies. These actin-rich inclusion bodies are known to modulate the synaptic plasticity and employ conspicuous effects on long-term potentiation and paired-pulse paradigms. Since the currently known drugs have very little effect in controlling the progression of these diseases, there is a need to develop therapeutic agents, which can have improved efficacy and bioavailability, and can transport across the blood–brain barrier. Moreover, finding novel targets involving compound screening is both laborious and is an expensive process in itself followed by equally tedious Food and Drug Administration (FDA) approval exercise. Finding alternative functions to the already existing FDA-approved molecules for reversing the progression of age-related proteinopathies is of utmost importance. In the current study, we decipher the role of a broad-spectrum general antibiotic (Ofloxacin) on actin polymerization dynamics using various biophysical techniques like right-angle light scattering, dynamic light scattering, circular dichroism spectrometry, isothermal titration calorimetry, scanning electron microscopy, etc. We have also performed in silico docking studies to deduce a plausible mechanism of the drug binding to the actin. We report that actin gets disrupted upon binding to Ofloxacin in a concentration-dependent manner. We have inferred that Ofloxacin, when attached to a drug delivery system, can act as a good candidate for the treatment of neuropathological diseases.
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Affiliation(s)
- Samridhi Pathak
- School of Chemical Sciences, University of Mumbai - Department of Atomic Energy Center for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Mumbai, India
| | - Haifa Parkar
- School of Chemical Sciences, University of Mumbai - Department of Atomic Energy Center for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Mumbai, India
| | - Sarita Tripathi
- School of Chemical Sciences, University of Mumbai - Department of Atomic Energy Center for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Mumbai, India
| | - Avinash Kale
- School of Chemical Sciences, University of Mumbai - Department of Atomic Energy Center for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Mumbai, India
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Pathak S, Tripathi S, Deori N, Ahmad B, Verma H, Lokhande R, Nagotu S, Kale A. Effect of tetracycline family of antibiotics on actin aggregation, resulting in the formation of Hirano bodies responsible for neuropathological disorders. J Biomol Struct Dyn 2020; 39:236-253. [PMID: 31948361 DOI: 10.1080/07391102.2020.1717629] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Actin, an ATPase superfamily protein, regulates some vital biological functions like cell locomotion, cytokinesis, synaptic plasticity and cell signaling in higher eukaryotes, and is dependent on the dynamics of actin polymerization process. Impaired regulation of actin polymerization has been implicated in the formation and deposition of rod-like paracrystalline structures called as Hirano bodies in neuronal cells of patients suffering from Alzheimer's disease, Pick's disease, Guam amyotrophic lateral sclerosis and parkinsonism-dementia complex. Aggregation of actin forming amorphous deposition in the brain cells is also associated with chronic alcoholism and aging of the neurons. In the current article, we propose the breaking of the highly amorphous and dysregulated actin aggregates using generic compounds like tetracycline, oxytetracycline, doxycycline and minocycline which are used as antibiotics against tuberculosis and infection caused due to various Gram-negative bacteria. We have investigated the effect and affinity of binding of these four compounds to that of actin aggregates using 90° light scattering, size exclusion chromatography, dynamic light scattering, circular dichroism, scanning electron microscopy, transmission electron microscopy imaging and kinetic analysis. The isothermal calorimetric measurements showed that the binding constant for the cycline family molecules used in this study range from 9.8 E4 M-1 to 1.3 E4 M-1. To understand the in vivo effect, we also studied the effect of these drugs on Saccharomyces cerevisiae Δend3 mutant cells. Our data suggest that these generic compounds can plausibly be used for the treatment of various neurodegenerative diseases occurring due to Hirano body formation in brain cells.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Samridhi Pathak
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
| | - Sarita Tripathi
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
| | - Nayan Deori
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Basir Ahmad
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India.,Protein Assembly Laboratory, JH-Institute of Molecular Medicine, New Delhi, India
| | - Hriday Verma
- School of Life Sciences, Jaipur National University, Jaipur, Rajasthan, India
| | - Rama Lokhande
- School of Life Sciences, Jaipur National University, Jaipur, Rajasthan, India
| | - Shirisha Nagotu
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Avinash Kale
- School of Chemical Sciences, UM-DAE Center for Excellence in Basic Sciences, University of Mumbai, Mumbai, Maharashtra, India
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Ishikawa-Ankerhold HC, Daszkiewicz W, Schleicher M, Müller-Taubenberger A. Actin-Interacting Protein 1 Contributes to Intranuclear Rod Assembly in Dictyostelium discoideum. Sci Rep 2017; 7:40310. [PMID: 28074884 PMCID: PMC5225641 DOI: 10.1038/srep40310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/02/2016] [Indexed: 12/21/2022] Open
Abstract
Intranuclear rods are aggregates consisting of actin and cofilin that are formed in the nucleus in consequence of chemical or mechanical stress conditions. The formation of rods is implicated in a variety of pathological conditions, such as certain myopathies and some neurological disorders. It is still not well understood what exactly triggers the formation of intranuclear rods, whether other proteins are involved, and what the underlying mechanisms of rod assembly or disassembly are. In this study, Dictyostelium discoideum was used to examine appearance, stages of assembly, composition, stability, and dismantling of rods. Our data show that intranuclear rods, in addition to actin and cofilin, are composed of a distinct set of other proteins comprising actin-interacting protein 1 (Aip1), coronin (CorA), filactin (Fia), and the 34 kDa actin-bundling protein B (AbpB). A finely tuned spatio-temporal pattern of protein recruitment was found during formation of rods. Aip1 is important for the final state of rod compaction indicating that Aip1 plays a major role in shaping the intranuclear rods. In the absence of both Aip1 and CorA, rods are not formed in the nucleus, suggesting that a sufficient supply of monomeric actin is a prerequisite for rod formation.
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Affiliation(s)
| | - Wioleta Daszkiewicz
- Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Michael Schleicher
- Department of Cell Biology (Anatomy III), Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
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Dong Y, Shahid-Salles S, Sherling D, Fechheimer N, Iyer N, Wells L, Fechheimer M, Furukawa R. De novo actin polymerization is required for model Hirano body formation in Dictyostelium. Biol Open 2016; 5:807-18. [PMID: 27215322 PMCID: PMC4920178 DOI: 10.1242/bio.014944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hirano bodies are eosinophilic, actin-rich inclusions found in autopsied brains in numerous neurodegenerative diseases. The mechanism of Hirano body formation is unknown. Mass spectrometry analysis was performed to identify proteins from partially purified model Hirano bodies from Dictyostelium This analysis identified proteins primarily belonging to ribosomes, proteasomes, mitochondria and cytoskeleton. Profilin, Arp/2/3 and WASH identified by mass spectrometry were found to colocalise with model Hirano bodies. Due to their roles in actin regulation, we selected these proteins for further investigation. Inhibition of the Arp2/3 complex by CK666 prevented formation of model Hirano bodies. Since Arp2/3 activation occurs via the WASH or WAVE complex, we next investigated how these proteins affect Hirano body formation. Whereas model Hirano bodies could form in WASH-deficient cells, they failed to form in cells lacking HSPC300, a member of the WAVE complex. We identified other proteins required for Hirano body formation that include profilin and VASP, an actin nucleation factor. In the case of VASP, both its G- and F-actin binding domains were required for model Hirano body formation. Collectively, our results indicate that de novo actin polymerization is required to form model Hirano bodies.
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Affiliation(s)
- Yun Dong
- Department of Cellular Biology, University of Georgia, Athens, GA, USA 30602
| | | | - Dan Sherling
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA USA 30602
| | - Nathan Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, GA, USA 30602
| | - Nathan Iyer
- Department of Cellular Biology, University of Georgia, Athens, GA, USA 30602
| | - Lance Wells
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA USA 30602
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, GA, USA 30602
| | - Ruth Furukawa
- Department of Cellular Biology, University of Georgia, Athens, GA, USA 30602
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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: 8.8] [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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Furgerson M, Clark JK, Crystal JD, Wagner JJ, Fechheimer M, Furukawa R. Hirano body expression impairs spatial working memory in a novel mouse model. Acta Neuropathol Commun 2014; 2:131. [PMID: 25178488 PMCID: PMC4160558 DOI: 10.1186/s40478-014-0131-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/15/2014] [Indexed: 11/29/2022] Open
Abstract
Introduction Hirano bodies are actin-rich intracellular inclusions found in the brains of patients with neurodegenerative conditions such as Alzheimer's disease or frontotemporal lobar degeneration-tau. While Hirano body ultrastructure and protein composition have been well studied, little is known about the physiological function of Hirano bodies in an animal model system. Results Utilizing a Cre/Lox system, we have generated a new mouse model which develops an age-dependent increase in the number of model Hirano bodies present in both the CA1 region of the hippocampus and frontal cortex. These mice develop normally and experience no overt neuron loss. Mice presenting model Hirano bodies have no abnormal anxiety or locomotor activity as measured by the open field test. However, mice with model Hirano bodies develop age-dependent impairments in spatial working memory performance assessed using a delayed win-shift task in an 8-arm radial maze. Synaptic transmission, short-term plasticity, and long-term plasticity was measured in the CA1 region from slices obtained from both the ventral and dorsal hippocampus in the same mice whose spatial working memory was assessed. Baseline synaptic responses, paired pulse stimulation and long-term potentiation measurements in the ventral hippocampus were indistinguishable from control mice. In contrast, in the dorsal hippocampus, synaptic transmission at higher stimulus intensities were suppressed in 3 month old mice with Hirano bodies as compared with control mice. In addition, long-term potentiation was enhanced in the dorsal hippocampus of 8 month old mice with Hirano bodies, concurrent with observed impairment of spatial working memory. Finally, an inflammatory response was observed at 8 months of age in mice with Hirano bodies as assessed by the presence of reactive astrocytes. Conclusion This study shows that the presence of model Hirano bodies initiates an inflammatory response, alters hippocampal synaptic responses, and impairs spatial working memory in an age-dependent manner. This suggests that Hirano bodies may promote disease progression. This new model mouse provides a tool to investigate how Hirano bodies interact with other pathologies associated with Alzheimer's disease. Hirano bodies likely play a complex and region specific role in the brain during neurodegenerative disease progression. Electronic supplementary material The online version of this article (doi:10.1186/s40478-014-0131-9) contains supplementary material, which is available to authorized users.
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Spears W, Furgerson M, Sweetnam JM, Evans P, Gearing M, Fechheimer M, Furukawa R. Hirano bodies differentially modulate cell death induced by tau and the amyloid precursor protein intracellular domain. BMC Neurosci 2014; 15:74. [PMID: 24929931 PMCID: PMC4084581 DOI: 10.1186/1471-2202-15-74] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/06/2014] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Hirano bodies are actin-rich paracrystalline inclusions found in brains of patients with Alzheimer's disease (AD), frontotemporal dementia (FTD), and in normal aged individuals. Although studies of post-mortem brain tissue provide clues of etiology, the physiological function of Hirano bodies remains unknown. A cell culture model was utilized to study the interactions of mutant tau proteins, model Hirano bodies, and GSK3β in human astrocytoma cells. RESULTS Most tau variants showed co-localization with model Hirano bodies. Cosedimentation assays revealed this interaction may be direct, as recombinant purified forms of tau are all capable of binding F-actin. Model Hirano bodies had no effect or enhanced cell death induced by tau in the absence of amyloid precursor protein intracellular domain (AICD). In the presence of AICD and tau, synergistic cell death was observed in most cases, and model Hirano bodies decreased this synergistic cell death, except for forms of tau that caused significant cell death in the presence of Hirano bodies only. A role for the kinase GSK3β is suggested by the finding that a dominant negative form of GSK3β reduces this synergistic cell death. A subset of Hirano bodies in brain tissue of both Alzheimer's disease and normal aged individuals was found to contain tau, with some Hirano bodies in Alzheimer's disease brains containing hyperphosphorylated tau. CONCLUSION The results demonstrate a complex interaction between tau and AICD involving activation of GSK3β in promoting cell death, and the ability of Hirano bodies to modulate this process.
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Affiliation(s)
- William Spears
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Matthew Furgerson
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | | | - Parker Evans
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Marla Gearing
- Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ruth Furukawa
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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Griffin P, Furukawa R, Piggott C, Maselli A, Fechheimer M. Requirements for Hirano body formation. EUKARYOTIC CELL 2014; 13:625-34. [PMID: 24632241 PMCID: PMC4060480 DOI: 10.1128/ec.00044-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 03/06/2014] [Indexed: 11/20/2022]
Abstract
Hirano bodies are paracrystalline F-actin-rich structures associated with diverse conditions, including neurodegeneration and aging. Generation of model Hirano bodies using altered forms of Dictyostelium 34-kDa actin-bundling protein allows studies of their physiological function and mechanism of formation. We describe a novel 34-kDa protein mutant, E60K, with a point mutation within the inhibitory domain of the 34-kDa protein. Expression of E60K in Dictyostelium induces the formation of model Hirano bodies. The E60K protein has activated actin binding and is calcium regulated, unlike other forms of the 34-kDa protein that induce Hirano bodies and that have activated actin binding but lack calcium regulation. Actin filaments in the presence of E60K in vitro show enhanced resistance to disassembly induced by latrunculin B. Actin filaments in model Hirano bodies are also protected from latrunculin-induced depolymerization. We used nocodazole and blebbistatin to probe the role of the microtubules and myosin II, respectively, in the formation of model Hirano bodies. In the presence of these inhibitors, model Hirano bodies can form but are smaller than controls at early times of formation. The ultrastructure of model Hirano bodies did not reveal any major difference in structure and organization in the presence of inhibitors. In summary, these results support the conclusion that formation of model Hirano bodies is promoted by gain-of-function actin filament bundling, which enhances actin filament stabilization. Microtubules and myosin II contribute to but are not required for formation of model Hirano bodies.
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Affiliation(s)
- Paul Griffin
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | - Ruth Furukawa
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | - Cleveland Piggott
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | - Andrew Maselli
- Department of Biological Sciences, Chicago State University, Chicago, Illinois, USA
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
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Singhrao SK. C1q, the classical complement pathway protein binds Hirano bodies in Pick's disease. Microsc Res Tech 2013; 76:606-11. [PMID: 23512330 DOI: 10.1002/jemt.22206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 02/04/2013] [Accepted: 02/27/2013] [Indexed: 11/06/2022]
Abstract
Haematoxylin/Eosin staining was performed to screen for Hirano bodies from the temporal lobe including the hippocampus in 10 Pick's disease cases containing Pick bodies. Although the inclusions were confirmed in 9 out of 10 cases, only 4 out of 10 were particularly enriched with the eosinophilic bodies. These were subjected to immunostaining with anticomplement antibodies and astrocyte marker antiglial fibrillary acidic protein antibody and the HLA class II CR3/43 antibody to visualize microglia. An intraneuronal Hirano body was observed in one case that otherwise contained mainly the extracellular inclusions. In all cases, the extracellular Hirano bodies were seen lying adjacent to soma of neurons within CA1 region of the hippocampus. The extracellular Hirano bodies stained intensely with C1q, the first component of the classical pathway of activation but remained unreactive against antibodies to C4 and the C3 activation products (C3b and iC3b) and the alternative complement pathway component factor B. Hirano bodies also remained negative with the antiglial fibrillary acidic protein for astrocytes and HLA class II antibody CR3/43 for microglia. The results demonstrate that Hirano bodies have strong immunoreactivity to C1q; however, whether other complement components are associated with these inclusions remains to be further investigated.
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Affiliation(s)
- Sim K Singhrao
- Oral & Dental Sciences Research Group, School of Postgraduate Medical & Dental Education, University of Central Lancashire, Preston, PR1 2HE, United Kingdom.
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Abstract
A peripheral nerve trunk is composed of nerve fascicles supported in a fibrous collagenous sheath and defined by concentric layers of cells (the perineurium) that separate the contents (the endoneurium) from its fibrous collagen support (the epineurium). In the endoneurium are myelinated and unmyelinated fibers that are axons combined with their supporting Schwann cells to provide physical and electrical connections with end-organs such as muscle fibers and sensory endings. Axons are tubular neuronal extensions with a cytoskeleton of neurotubules and tubulin along which organelles and proteins can travel between the neuronal cell body and the axon terminal. During development some axons enlarge and are covered by a chain of Schwann cells each associated with just one axon. As the axons grow in diameter, the Schwann cells wrap round them to produce a myelin sheath. This consists of many layers of compacted Schwann cell membrane plus some additional proteins. Adjacent myelin segments connect at highly specialized structures, the nodes of Ranvier. Myelin insulates the axon so that the nerve impulse can jump from one node to the next. The region adjacent to the node, the paranodal segment, is the site of myelin terminations on the axolemma. There are connections here between the Schwann cell and the axon via a complex chain of proteins. The Schwann cell cytoplasm in the adjacent segment, the juxtaparanode, contains most of the Schwann cell mitochondria. In addition to the node, continuity of myelin lamellae is broken at intervals along the internode by helical regions of decompaction known as Schmidt-Lanterman incisures; these are seen as paler conical segments in suitably stained microscopical preparations and provide a pathway between the adaxonal and abaxonal cytoplasm. Smaller axons without a myelin sheath conduct very much more slowly and have a more complex relationship with their supporting Schwann cells that has important implications for repair.
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Affiliation(s)
- Rosalind King
- Department of Clinical Neurosciences, Institute of Neurology, University College London, Royal Free Campus, London, UK.
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Furgerson M, Fechheimer M, Furukawa R. Model Hirano bodies protect against tau-independent and tau-dependent cell death initiated by the amyloid precursor protein intracellular domain. PLoS One 2012; 7:e44996. [PMID: 23028730 PMCID: PMC3445605 DOI: 10.1371/journal.pone.0044996] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 08/14/2012] [Indexed: 11/19/2022] Open
Abstract
The main pathological hallmarks of Alzheimer's disease are amyloid-beta plaques and neurofibrillary tangles, which are primarily composed of amyloid precursor protein (APP) and tau, respectively. These proteins and their role in the mechanism of neurodegeneration have been extensively studied. Hirano bodies are a frequently occurring pathology in Alzheimer's disease as well as other neurodegenerative diseases. However, the physiological role of Hirano bodies in neurodegenerative diseases has yet to be determined. We have established cell culture models to study the role of Hirano bodies in amyloid precursor protein and tau-induced cell death mechanisms. Exogenous expression of APP and either of its c-terminal fragments c31 or Amyloid Precursor Protein Intracellular Domain c58 (AICDc58) enhance cell death. The presence of tau is not required for this enhanced cell death. However, the addition of a hyperphosphorylated tau mimic 352PHPtau significantly increases cell death in the presence of both APP and c31 or AICDc58 alone. The mechanism of cell death induced by APP and its c-terminal fragments and tau was investigated. Fe65, Tip60, p53, and caspases play a role in tau-independent and tau-dependent cell death. In addition, apoptosis was determined to contribute to cell death. The presence of model Hirano bodies protected against cell death, indicating Hirano bodies may play a protective role in neurodegeneration.
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Affiliation(s)
- Matthew Furgerson
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Ruth Furukawa
- Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
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Ha S, Furukawa R, Fechheimer M. Association of AICD and Fe65 with Hirano bodies reduces transcriptional activation and initiation of apoptosis. Neurobiol Aging 2011; 32:2287-98. [PMID: 20133016 PMCID: PMC2894277 DOI: 10.1016/j.neurobiolaging.2010.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 12/22/2009] [Accepted: 01/07/2010] [Indexed: 02/03/2023]
Abstract
Hirano bodies are cytoplasmic inclusions predominantly found in the central nervous system associated with various conditions including aging and Alzheimer's disease (AD). Since most studies of Hirano bodies have been performed in post-mortem samples, the physiological roles of Hirano bodies have not been investigated. Astrocytoma H4 cells were employed to test the hypothesis that Hirano bodies interact with and modulate signaling by the C-terminal fragment of amyloid-β precursor protein (AICD). We demonstrated by immunofluorescence and immunoprecipitation that model Hirano bodies accumulate AICD. Since stimulation of transcription by AICD is dependent on its interaction with the nuclear adaptor protein Fe65, we examined localization of Fe65, and employed a dual luciferase reporter assay to test the effects of Hirano bodies on AICD- and Fe65-dependent modulation of gene expression. We find that both AICD and Fe65 are co-localized in model Hirano bodies. Model Hirano bodies also down-regulate both AICD-dependent apoptosis and AICD- and Fe65-dependent transcriptional activity. Thus, association of AICD and Fe65 with Hirano bodies impedes their function in promoting apoptosis and modulating transcription.
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Affiliation(s)
- Sangdeuk Ha
- Department of Cellular Biology, University of Georgia, Athens, GA 30602 USA
| | - Ruth Furukawa
- Department of Cellular Biology, University of Georgia, Athens, GA 30602 USA
| | - Marcus Fechheimer
- Department of Cellular Biology, University of Georgia, Athens, GA 30602 USA
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15
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Ha S, Furukawa R, Stramiello M, Wagner JJ, Fechheimer M. Transgenic mouse model for the formation of Hirano bodies. BMC Neurosci 2011; 12:97. [PMID: 21978358 PMCID: PMC3203848 DOI: 10.1186/1471-2202-12-97] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 10/06/2011] [Indexed: 12/28/2022] Open
Abstract
Background Hirano bodies are actin-rich cytoplasmic inclusions found predominantly in the brain in association with a variety of conditions including aging and Alzheimer's disease. The function of Hirano bodies in normal aging and in progression of disease has not been extensively investigated due to a lack of experimental model systems. We have developed a transgenic mouse model by expression of a gain-of-function actin cross-linking protein mutant. Results We used the Cre/loxP system to permit tissue specific expression of Hirano bodies, and employed the murine Thy 1 promoter to drive expression of Cre recombinase in the brain. Hirano bodies were observed in the cerebral cortex and hippocampus of homozygous double transgenic 6 month old mice containing Cre. The Hirano bodies were eosinophilic rods, and also exhibited the paracrystalline F-actin filament organization that is characteristic of these inclusions. Mice with Hirano bodies appear healthy and fertile, but exhibited some alterations in both short-term and long-term synaptic plasticity, including paired-pulse depression rather than facilitation, and decreased magnitude of early LTP. Conclusions Hirano bodies are not lethal and appear to have little or no effect on histology and tissue organization. Hirano bodies do modulate synaptic plasticity and exert clearly discernable effects on LTP and paired-pulse paradigms. This model system will allow us to investigate the impact of Hirano bodies in vivo, the pathways for formation and degradation of Hirano bodies, and whether Hirano bodies promote or modulate development of pathology and disease progression.
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Affiliation(s)
- Sangdeuk Ha
- Department Cellular Biology, University of Georgia, Athens, GA 30602, USA
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16
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King RHM, Chandler D, Lopaticki S, Huang D, Blake J, Muddle JR, Kilpatrick T, Nourallah M, Miyata T, Okuda T, Carter KW, Hunter M, Angelicheva D, Morahan G, Kalaydjieva L. Ndrg1 in development and maintenance of the myelin sheath. Neurobiol Dis 2011; 42:368-80. [PMID: 21303696 DOI: 10.1016/j.nbd.2011.01.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 01/13/2011] [Accepted: 01/28/2011] [Indexed: 02/04/2023] Open
Abstract
CMT4D disease is a severe autosomal recessive demyelinating neuropathy with extensive axonal loss leading to early disability, caused by mutations in the N-myc downstream regulated gene 1 (NDRG1). NDRG1 is expressed at particularly high levels in the Schwann cell (SC), but its physiological function(s) are unknown. To help with their understanding, we characterise the phenotype of a new mouse model, stretcher (str), with total Ndrg1 deficiency, in comparison with the hypomorphic Ndrg1 knock-out (KO) mouse. While both models display normal initial myelination and a transition to overt pathology between weeks 3 and 5, the markedly more severe str phenotype suggests that even low Ndrg1 expression results in significant phenotype rescue. Neither model replicates fully the features of CMT4D: although axon damage is present, regenerative capacity is unimpaired and the mice do not display the early severe axonal loss typical of the human disease. The widespread large fibre demyelination coincides precisely with the period of rapid growth of the animals and the dramatic (160-500-fold) increase in myelin volume and length in large fibres. This is followed by stabilisation after week 10, while small fibres remain unaffected. Gene expression profiling of str peripheral nerve reveals non-specific secondary changes at weeks 5 and 10 and preliminary data point to normal proteasomal function. Our findings do not support the proposed roles of NDRG1 in growth arrest, terminal differentiation, gene expression regulation and proteasomal degradation. Impaired SC trafficking failing to meet the considerable demands of nerve growth, emerges as the likely pathogenetic mechanism in NDRG1 deficiency.
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Affiliation(s)
- Rosalind H M King
- Department of Clinical Neurosciences, Institute of Neurology, UCL, London NW3 2PF, UK.
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17
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Amberg D, Leadsham JE, Kotiadis V, Gourlay CW. Cellular ageing and the actin cytoskeleton. Subcell Biochem 2011; 57:331-52. [PMID: 22094429 DOI: 10.1007/978-94-007-2561-4_15] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
For some time the view that the actin cytoskeleton acts primarily as a scaffold, to be assembled in response to a signaling cascade as an end point in the pathway, has prevailed. However, it is now clear that the dynamic nature of the cytoskeleton is linked to downstream signaling events that further modulate cellular activity, and which can determine cell fate. Examples of this lie within the regulation of programmed cell death, the maintenance of homeostasis and the process of cellular ageing. In yeast the actin cytoskeleton has been shown to interact directly with signaling pathways known to be important in the regulation of both ageing and cell death. For example it has been discovered that the level of damage sustained by the actin cytoskeleton under conditions of oxidative stressoxidative stress is directly linked to apoptosis. Further evidence comes from the finding that actin based propulsion mechanisms are required for the inheritance of mitochondria and anti-ageing factors into newly formed cells. In addition to this actin is known to directly influence the formation of protein aggregations. In this chapter we will discuss these points and postulate as to their significance with respect to the maintenance of cellular homeostasis.
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Affiliation(s)
- David Amberg
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA,
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18
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Schmauch C, Claussner S, Zöltzer H, Maniak M. Targeting the actin-binding protein VASP to late endosomes induces the formation of giant actin aggregates. Eur J Cell Biol 2009; 88:385-96. [DOI: 10.1016/j.ejcb.2009.02.185] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 02/12/2009] [Accepted: 02/19/2009] [Indexed: 11/24/2022] Open
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19
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Annesley SJ, Fisher PR. Dictyostelium discoideum--a model for many reasons. Mol Cell Biochem 2009; 329:73-91. [PMID: 19387798 DOI: 10.1007/s11010-009-0111-8] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 04/02/2009] [Indexed: 10/25/2022]
Abstract
The social amoeba or cellular slime mould Dictyostelium discoideum is a "professional" phagocyte that has long been recognized for its value as a biomedical model organism, particularly in studying the actomyosin cytoskeleton and chemotactic motility in non-muscle cells. The complete genome sequence of D. discoideum is known, it is genetically tractable, readily grown clonally as a eukaryotic microorganism and is highly accessible for biochemical, cell biological and physiological studies. These are the properties it shares with other microbial model organisms. However, Dictyostelium combines these with a unique life style, with motile unicellular and multicellular stages, and multiple cell types that offer for study an unparalleled variety of phenotypes and associated signalling pathways. These advantages have led to its recent emergence as a valuable model organism for studying the molecular pathogenesis and treatment of human disease, including a variety of infectious diseases caused by bacterial and fungal pathogens. Perhaps surprisingly, this organism, without neurons or brain, has begun to yield novel insights into the cytopathology of mitochondrial diseases as well as other genetic and idiopathic disorders affecting the central nervous system. Dictyostelium has also contributed significantly to our understanding of NDP kinase, as it was the Dictyostelium enzyme whose structure was first determined and related to enzymatic activity. The phenotypic richness and tractability of Dictyostelium should provide a fertile arena for future exploration of NDPK's cellular roles.
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Affiliation(s)
- Sarah J Annesley
- Department of Microbiology, La Trobe University, Bundoora, VIC 3086, Australia
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20
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Formation of Hirano bodies after inducible expression of a modified form of an actin-cross-linking protein. EUKARYOTIC CELL 2009; 8:852-7. [PMID: 19363062 DOI: 10.1128/ec.00379-08] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hirano bodies are cytoplasmic inclusions composed mainly of actin and actin-associated proteins. The formation of Hirano bodies during various neurodegenerative disorders, including Alzheimer's disease and amyotrophic lateral sclerosis, has been reported. Although the underlying molecular mechanisms that lead to the formation of these inclusions in the brain are not known, expression of the C-terminal fragment (CT) (amino acids 124 to 295) from the endogenous 34-kDa actin-binding protein of Dictyostelium discoideum leads to the formation of actin inclusions in vivo. In the current study, we report the development of an inducible expression system to study the early phases of Hirano body formation using an inducible promoter system (rnrB). By fusing the CT to a green fluorescent protein (CT-GFP), we monitored protein expression and localization by fluorescence microscopy, flow cytometry, and Western blot analysis. We observed an increase in the number and size of inclusions formed following induction of the CT-GFP vector system. Time-lapse microscopy studies revealed that the CT-GFP foci associated with the cell cortex and fused to form a single large aggregate. Transmission electron microscopy further demonstrates that these inclusions have a highly ordered ultrastructure, a pathological hallmark of Hirano bodies observed in postmortem brain samples from patients with various neurodegenerative disorders. Collectively, this system provides a method to visualize and characterize the events that surround early actin inclusion formation in a eukaryotic model.
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21
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Michaud JLR, Hosseini-Abardeh M, Farah K, Kennedy CRJ. Modulating α-actinin-4 dynamics in podocytes. ACTA ACUST UNITED AC 2009; 66:166-78. [DOI: 10.1002/cm.20339] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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22
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Kim DH, Davis RC, Furukawa R, Fechheimer M. Autophagy contributes to degradation of Hirano bodies. Autophagy 2009; 5:44-51. [PMID: 18989098 DOI: 10.4161/auto.5.1.7228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hirano bodies are actin-rich inclusions reported most frequently in the hippocampus in association with a variety of conditions including neurodegenerative diseases, and aging. We have developed a model system for formation of Hirano bodies in Dictyostelium and cultured mammalian cells to permit detailed studies of the dynamics of these structures in living cells. Model Hirano bodies are frequently observed in membrane-enclosed vesicles in mammalian cells consistent with a role of autophagy in the degradation of these structures. Clearance of Hirano bodies by an exocytotic process is supported by images from electron microscopy showing extracellular release of Hirano bodies, and observation of Hirano bodies in the culture medium of Dictyostelium and mammalian cells. An autophagosome marker protein Atg8-GFP, was co-localized with model Hirano bodies in wild type Dictyostelium cells, but not in atg5(-) or atg1-1 autophagy mutant strains. Induction of model Hirano bodies in Dictyostelium with a high level expression of 34 kDa DeltaEF1 from the inducible discoidin promoter resulted in larger Hirano bodies and a cessation of cell doubling. The degradation of model Hirano bodies still occurred rapidly in autophagy mutant (atg5(-)) Dictyostelium, suggesting that other mechanisms such as the ubiquitin-mediated proteasome pathway could contribute to the degradation of Hirano bodies. Chemical inhibition of the proteasome pathway with lactacystin, significantly decreased the turnover of Hirano bodies in Dictyostelium providing direct evidence that autophagy and the proteasome can both contribute to degradation of Hirano bodies. Short term treatment of mammalian cells with either lactacystin or 3-methyl adenine results in higher levels of Hirano bodies and a lower level of viable cells in the cultures, supporting the conclusion that both autophagy and the proteasome contribute to degradation of Hirano bodies.
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Affiliation(s)
- Dong-Hwan Kim
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
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23
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Medvedeva AV, Molotkov DA, Nikitina EA, Popov AV, Karagodin DA, Baricheva EM, Savvateeva-Popova EV. Systemic regulation of genetic and cytogenetic processes by a signal cascade of actin remodeling: Locus agnostic in Drosophila. RUSS J GENET+ 2008. [DOI: 10.1134/s1022795408060069] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Lázaro-Diéguez F, Aguado C, Mato E, Sánchez-Ruíz Y, Esteban I, Alberch J, Knecht E, Egea G. Dynamics of an F-actin aggresome generated by the actin-stabilizing toxin jasplakinolide. J Cell Sci 2008; 121:1415-25. [PMID: 18398002 DOI: 10.1242/jcs.017665] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In this study, we report the formation of several cytoplasmic inclusion bodies composed of filamentous actin (F-actin) and generated by experimental treatments using depolymerizing or stabilizing actin toxins in neuronal and non-neuronal mammalian cell lines. The actin-stabilizing toxin jasplakinolide (Jpk) induced, in a microtubule-dependent manner, a single, large F-actin aggregate, which contained beta- and gamma-actin, ADF/cofilin, cortactin, and the actin nucleator Arp2/3. This aggregate was tightly associated with the Golgi complex and mitochondria, and was surrounded by vimentin intermediate filaments, microtubules and MAP4. Therefore, the Jpk-induced single, large F-actin aggregate fits the established criteria for being considered an aggresome. Lysosomes and/or autophagic vacuoles, proteasomes and microtubules were found to directly participate in the dissolution of this F-actin aggresome. Finally, the model reported here is simple, highly reproducible and reversible, and it provides an opportunity to test pharmacological agents that interfere with the formation, maintenance and/or disappearance of F-actin-enriched pathological inclusion bodies.
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Affiliation(s)
- Francisco Lázaro-Diéguez
- Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
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25
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Davis RC, Furukawa R, Fechheimer M. A cell culture model for investigation of Hirano bodies. Acta Neuropathol 2008; 115:205-17. [PMID: 17978823 DOI: 10.1007/s00401-007-0275-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 07/24/2007] [Accepted: 07/26/2007] [Indexed: 11/28/2022]
Abstract
Hirano bodies are paracrystalline F-actin-rich aggregations associated with a variety of conditions including aging, and neurodegenerative diseases. The composition and structure of these inclusions have been described by immunohistochemistry and ultrastructure, respectively. However, studies of the physiological function and dynamics of Hirano bodies have been hindered due to lack of a facile in vitro experimental system. We have developed a model for formation of Hirano bodies in mammalian cell cultures by expression of the carboxy-terminal fragment (CT) of a 34-kDa actin-bundling protein. Expression of the CT protein induces F-actin rearrangement in HEK 293, HeLa, Cos7 cells, neuroblastoma and astrocytic cells, and in primary neurons. We have termed these structures model Hirano bodies, since their composition and ultrastructure is quite similar to that reported in vivo. Model Hirano bodies in cell cultures sometimes appeared to be formed of a number of smaller domains, suggesting that small aggregates are intermediates in the formation of Hirano bodies. Stable lines expressing CT and bearing model Hirano bodies exhibit normal growth, morphology, and motility. This model provides a valuable system for the study of the dynamics of Hirano bodies, and their role in disease processes.
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Affiliation(s)
- Richard C Davis
- Department of Cellular Biology, University of Georgia, 724 Biological Sciences, Athens, GA 30602, USA
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26
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Schoser BGH, Müller-Höcker J, Horvath R, Gempel K, Pongratz D, Lochmüller H, Müller-Felber W. Adult-onset glycogen storage disease type 2: clinico-pathological phenotype revisited. Neuropathol Appl Neurobiol 2007; 33:544-59. [PMID: 17573812 DOI: 10.1111/j.1365-2990.2007.00839.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The need for clinical awareness and diagnostic precision of glycogen storage disease type 2 (GSD2) has increased, as enzyme replacement therapy has become available. So far, only small series have reported the muscle pathology of late-onset GSD2. We reassessed 43 muscle biopsies of 38 GSD2 patients. In all patients the diagnosis of GSD2 has been established by biochemistry and/or mutational analysis of the GAA gene. Additionally to the expected morphological features, ultrastructural analysis revealed a high incidence of autophagic vacuoles, lipofuscin debris, structural Z-line disorganization and histological neurogenic-like pattern that were not thoroughly appreciated, previously. Comparing age at onset and morphology, excessive vacuolar and autophagic myopathy and mitochondrial disorganization of virtually all fibres is common in infants. At juvenile onset, a more moderate vacuolization without significant differences in overall morphology is notable. At late-onset, the spectrum of vacuolar myopathy is more divergent, ranging from almost normal to severe. Here pronounced secondary alterations are observed that include lipofuscin debris, autophagic vacuoles with residual lysosomal bodies and granular inclusions, structural mitochondrial and Z-line texture alterations. Moreover, there is a high incidence of subtle neurogenic-like alteration in all subtypes. Nineteen patients were genetically tested; in 15 patients the common leaky splicing mutation c.-45T>G (or IVS1-13T>G) in intron1 of the GAA gene was found on at least one allele, facilitating genetic screening. In our patients, GAA genotype appears not to be associated with secondary alterations such as autophagic vacuoles, structural alterations or neurogenic-like changes. These findings may have implications for our understanding of the pathogenesis of GSD2 and for assessing therapeutic success of enzyme replacement therapy.
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Affiliation(s)
- B G H Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany.
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27
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Alafag JII, Moon EK, Hong YC, Chung DI, Kong HH. Molecular and biochemical characterization of a novel actin bundling protein in Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2007; 44:331-41. [PMID: 17170575 PMCID: PMC2559136 DOI: 10.3347/kjp.2006.44.4.331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Actin binding proteins play key roles in cell structure and movement particularly as regulators of the assembly, stability and localization of actin filaments in the cytoplasm. In the present study, a cDNA clone encoding an actin bundling protein named as AhABP was isolated from Acanthamoeba healyi, a causative agent of granulomatous amebic encephalitis. This clone exhibited high similarity with genes of Physarum polycephalum and Dictyostelium discoideum, which encode actin bundling proteins. Domain search analysis revealed the presence of essential conserved regions, i.e., an active actin binding site and 2 putative calcium binding EF-hands. Transfected amoeba cells demonstrated that AhABP is primarily localized in phagocytic cups, peripheral edges, pseudopods, and in cortical cytoplasm where actins are most abundant. Moreover, AhABP after the deletion of essential regions formed ellipsoidal inclusions within transfected cells. High-speed co-sedimentation assays revealed that AhABP directly interacted with actin in the presence of up to 10 microM of calcium. Under the electron microscope, thick parallel bundles were formed by full length AhABP, in contrast to the thin actin bundles formed by constructs with deletion sites. In the light of these results, we conclude that AhABP is a novel actin bundling protein that is importantly associated with actin filaments in the cytoplasm.
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Affiliation(s)
- Joanna It-Itan Alafag
- Department of Parasitology, Kyungpook National University School of Medicine, Daegu, Korea
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28
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Jang DH, Han JH, Lee SH, Lee YS, Park H, Lee SH, Kim H, Kaang BK. Cofilin expression induces cofilin-actin rod formation and disrupts synaptic structure and function in Aplysia synapses. Proc Natl Acad Sci U S A 2005; 102:16072-7. [PMID: 16247020 PMCID: PMC1276089 DOI: 10.1073/pnas.0507675102] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cofilin-actin rods are inclusion-like structures that are induced by certain chemical or physical stresses in cultured cells, and the rods formed in neurons are thought to be associated with neurodegeneration. Here, we cloned an Aplysia cofilin homolog and overexpressed it in cultured neurons. Overexpressed cofilin formed rod-like structures that included actin. The overall neuronal morphology was unaffected by cofilin overexpression; however, a decrease in number of synaptic varicosities was observed. Consistent with this structural change by cofilin overexpression, the synaptic strength was reduced, and furthermore, the long-term facilitation elicited by repeated pulses of 5-hydroxytryptamine was impaired in sensory-to-motor synapses. However, cofilin overexpression did not induce programmed cell death. These findings suggest that the formation of cofilin-actin rod-like structures can lead to neurodegeneration, and this might be a mechanism of rundown of neuronal and synaptic function without cell death in neurodegenerative diseases.
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Affiliation(s)
- Dong-Hyuk Jang
- National Research Laboratory of Neurobiology, Institute of Molecular Biology and Genetics, School of Biological Sciences, College of Natural Sciences, Seoul National University, San 56-1 Silim-dong Kwanak-gu, Seoul 151-742, Korea
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