1
|
Tandon S, Sarkar S. Glutamine stimulates the S6K/4E-BP branch of insulin signalling pathway to mitigate human poly(Q) disorders in Drosophila disease models. Nutr Neurosci 2024; 27:783-794. [PMID: 37658796 DOI: 10.1080/1028415x.2023.2253028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
OBJECTIVE AND METHODS Since, the S6K/4E-BP sub-pathway can be stimulated by various amino acids; we extended our investigation to examine if oral feeding of amino acids delivers rescue against human poly(Q) toxicity in Drosophila. We utilised Drosophila models of two different poly(Q) disorders to test our hypothesis. Glutamine was fed to the test flies orally mixed in the food. Control and treated flies were then tested for different parameters, such as formation of poly(Q) aggregates and neurodegeneration, to evaluate glutamine's proficiency in mitigating poly(Q) neurotoxicity. RESULTS Our study, for the first time, reports that glutamine feeding stimulates the growth promoting S6K/4E-BP branch of insulin signalling pathway and restricts pathogenesis of poly(Q) disorders in Drosophila disease models. We noted that glutamine treatment restricts the formation of neurotoxic poly(Q) aggregates and minimises neuronal deaths. Further, glutamine treatment re-establishes the chromatin architecture by improving the histone acetylation which is otherwise compromised in poly(Q) expressing neuronal cells. DISCUSSION Since, the insulin signalling pathway as well as mechanism of action of glutamine are fairly conserved between human and Drosophila, our finding strongly suggests that glutamine holds immense potential to be developed as an intervention therapy against the incurable human poly(Q) disorders.
Collapse
Affiliation(s)
- Shweta Tandon
- Department of Genetics, University of Delhi South Campus, New Delhi, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, New Delhi, India
| |
Collapse
|
2
|
Desai M, Hemant, Deo A, Naik J, Dhamale P, Kshirsagar A, Bose T, Majumdar A. Mrj is a chaperone of the Hsp40 family that regulates Orb2 oligomerization and long-term memory in Drosophila. PLoS Biol 2024; 22:e3002585. [PMID: 38648719 PMCID: PMC11034981 DOI: 10.1371/journal.pbio.3002585] [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: 03/27/2023] [Accepted: 03/12/2024] [Indexed: 04/25/2024] Open
Abstract
Orb2 the Drosophila homolog of cytoplasmic polyadenylation element binding (CPEB) protein forms prion-like oligomers. These oligomers consist of Orb2A and Orb2B isoforms and their formation is dependent on the oligomerization of the Orb2A isoform. Drosophila with a mutation diminishing Orb2A's prion-like oligomerization forms long-term memory but fails to maintain it over time. Since this prion-like oligomerization of Orb2A plays a crucial role in the maintenance of memory, here, we aim to find what regulates this oligomerization. In an immunoprecipitation-based screen, we identify interactors of Orb2A in the Hsp40 and Hsp70 families of proteins. Among these, we find an Hsp40 family protein Mrj as a regulator of the conversion of Orb2A to its prion-like form. Mrj interacts with Hsp70 proteins and acts as a chaperone by interfering with the aggregation of pathogenic Huntingtin. Unlike its mammalian homolog, we find Drosophila Mrj is neither an essential gene nor causes any gross neurodevelopmental defect. We observe a loss of Mrj results in a reduction in Orb2 oligomers. Further, Mrj knockout exhibits a deficit in long-term memory and our observations suggest Mrj is needed in mushroom body neurons for the regulation of long-term memory. Our work implicates a chaperone Mrj in mechanisms of memory regulation through controlling the oligomerization of Orb2A and its association with the translating ribosomes.
Collapse
Affiliation(s)
- Meghal Desai
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Hemant
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Ankita Deo
- Institute of Bioinformatics and Biotechnology (IBB), Savitribai Phule Pune University, Pune, India
| | - Jagyanseni Naik
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Prathamesh Dhamale
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Avinash Kshirsagar
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| | - Tania Bose
- Institute of Bioinformatics and Biotechnology (IBB), Savitribai Phule Pune University, Pune, India
| | - Amitabha Majumdar
- National Centre for Cell Science, Savitribai Phule Pune University Campus, Pune, India
| |
Collapse
|
3
|
Lobato AG, Ortiz-Vega N, Zhu Y, Neupane D, Meier KK, Zhai RG. Copper enhances aggregational toxicity of mutant huntingtin in a Drosophila model of Huntington's Disease. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166928. [PMID: 38660915 PMCID: PMC11046041 DOI: 10.1016/j.bbadis.2023.166928] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 04/26/2024]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder with clinical presentations of moderate to severe cognitive, motor, and psychiatric disturbances. HD is caused by the trinucleotide repeat expansion of CAG of the huntingtin (HTT) gene. The mutant HTT protein containing pathological polyglutamine (polyQ) extension is prone to misfolding and aggregation in the brain. It has previously been observed that copper and iron concentrations are increased in the striata of post-mortem human HD brains. Although it has been shown that the accumulation of mutant HTT protein can interact with copper, the underlying HD progressive phenotypes due to copper overload remains elusive. Here, in a Drosophila model of HD, we showed that copper induces dose-dependent aggregational toxicity and enhancement of Htt-induced neurodegeneration. Specifically, we found that copper increases mutant Htt aggregation, enhances the accumulation of Thioflavin S positive β-amyloid structures within Htt aggregates, and consequently alters autophagy in the brain. Administration of copper chelator D-penicillamine (DPA) through feeding significantly decreases β-amyloid aggregates in the HD pathological model. These findings reveal a direct role of copper in potentiating mutant Htt protein-induced aggregational toxicity, and further indicate the potential impact of environmental copper exposure in the disease onset and progression of HD.
Collapse
Affiliation(s)
- Amanda G Lobato
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA; Graduate Program in Human Genetics and Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Natalie Ortiz-Vega
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA; Graduate Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Yi Zhu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Deepa Neupane
- Graduate Program in Chemistry, University of Miami, Coral Gables, Florida, USA; Department of Chemistry, University of Miami, Coral Gables, Florida, USA
| | - Katlyn K Meier
- Department of Chemistry, University of Miami, Coral Gables, Florida, USA
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
4
|
Swinter K, Salah D, Rathnayake R, Gunawardena S. PolyQ-Expansion Causes Mitochondria Fragmentation Independent of Huntingtin and Is Distinct from Traumatic Brain Injury (TBI)/Mechanical Stress-Mediated Fragmentation Which Results from Cell Death. Cells 2023; 12:2406. [PMID: 37830620 PMCID: PMC10572422 DOI: 10.3390/cells12192406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 10/14/2023] Open
Abstract
Mitochondrial dysfunction has been reported in many Huntington's disease (HD) models; however, it is unclear how these defects occur. Here, we test the hypothesis that excess pathogenic huntingtin (HTT) impairs mitochondrial homeostasis, using Drosophila genetics and pharmacological inhibitors in HD and polyQ-expansion disease models and in a mechanical stress-induced traumatic brain injury (TBI) model. Expression of pathogenic HTT caused fragmented mitochondria compared to normal HTT, but HTT did not co-localize with mitochondria under normal or pathogenic conditions. Expression of pathogenic polyQ (127Q) alone or in the context of Machado Joseph Disease (MJD) caused fragmented mitochondria. While mitochondrial fragmentation was not dependent on the cellular location of polyQ accumulations, the expression of a chaperone protein, excess of mitofusin (MFN), or depletion of dynamin-related protein 1 (DRP1) rescued fragmentation. Intriguingly, a higher concentration of nitric oxide (NO) was observed in polyQ-expressing larval brains and inhibiting NO production rescued polyQ-mediated fragmented mitochondria, postulating that DRP1 nitrosylation could contribute to excess fission. Furthermore, while excess PI3K, which suppresses polyQ-induced cell death, did not rescue polyQ-mediated fragmentation, it did rescue fragmentation caused by mechanical stress/TBI. Together, our observations suggest that pathogenic polyQ alone is sufficient to cause DRP1-dependent mitochondrial fragmentation upstream of cell death, uncovering distinct physiological mechanisms for mitochondrial dysfunction in polyQ disease and mechanical stress.
Collapse
Affiliation(s)
| | | | | | - Shermali Gunawardena
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260, USA
| |
Collapse
|
5
|
Santarelli S, Londero C, Soldano A, Candelaresi C, Todeschini L, Vernizzi L, Bellosta P. Drosophila melanogaster as a model to study autophagy in neurodegenerative diseases induced by proteinopathies. Front Neurosci 2023; 17:1082047. [PMID: 37274187 PMCID: PMC10232775 DOI: 10.3389/fnins.2023.1082047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 04/14/2023] [Indexed: 06/06/2023] Open
Abstract
Proteinopathies are a large group of neurodegenerative diseases caused by both genetic and sporadic mutations in particular genes which can lead to alterations of the protein structure and to the formation of aggregates, especially toxic for neurons. Autophagy is a key mechanism for clearing those aggregates and its function has been strongly associated with the ubiquitin-proteasome system (UPS), hence mutations in both pathways have been associated with the onset of neurodegenerative diseases, particularly those induced by protein misfolding and accumulation of aggregates. Many crucial discoveries regarding the molecular and cellular events underlying the role of autophagy in these diseases have come from studies using Drosophila models. Indeed, despite the physiological and morphological differences between the fly and the human brain, most of the biochemical and molecular aspects regulating protein homeostasis, including autophagy, are conserved between the two species.In this review, we will provide an overview of the most common neurodegenerative proteinopathies, which include PolyQ diseases (Huntington's disease, Spinocerebellar ataxia 1, 2, and 3), Amyotrophic Lateral Sclerosis (C9orf72, SOD1, TDP-43, FUS), Alzheimer's disease (APP, Tau) Parkinson's disease (a-syn, parkin and PINK1, LRRK2) and prion diseases, highlighting the studies using Drosophila that have contributed to understanding the conserved mechanisms and elucidating the role of autophagy in these diseases.
Collapse
Affiliation(s)
- Stefania Santarelli
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
| | - Chiara Londero
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
| | - Alessia Soldano
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
- Department of Neuroscience, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
| | - Carlotta Candelaresi
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
| | - Leonardo Todeschini
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
| | - Luisa Vernizzi
- Institute of Molecular Life Sciences, University of Zurich, Zürich, Switzerland
| | - Paola Bellosta
- Department of Cellular, Computational and Integrative Biology (CiBiO), University of Trento, Trento, Italy
- Department of Medicine, NYU Langone Medical Center, New York, NY, United States
| |
Collapse
|
6
|
Krzystek TJ, White JA, Rathnayake R, Thurston L, Hoffmar-Glennon H, Li Y, Gunawardena S. HTT (huntingtin) and RAB7 co-migrate retrogradely on a signaling LAMP1-containing late endosome during axonal injury. Autophagy 2023; 19:1199-1220. [PMID: 36048753 PMCID: PMC10012955 DOI: 10.1080/15548627.2022.2119351] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/09/2022] Open
Abstract
ABBREVIATIONS Atg5: Autophagy-related 5; Atg8a: Autophagy-related 8a; AL: autolysosome; AP: autophagosome; BAF1: bafilomycin A1; BDNF: brain derived neurotrophic factor; BMP: bone morphogenetic protein; Cyt-c-p: Cytochrome c proximal; CQ: chloroquine; DCTN1: dynactin 1; Dhc: dynein heavy chain; EE: early endosome; DYNC1I1: dynein cytoplasmic 1 intermediate chain 1; HD: Huntington disease; HIP1/Hip1: huntingtin interacting protein 1; HTT/htt: huntingtin; iNeuron: iPSC-derived human neurons; IP: immunoprecipitation; Khc: kinesin heavy chain; KIF5C: kinesin family member 5C; LAMP1/Lamp1: lysosomal associated membrane protein 1; LE: late endosome; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAP3K12/DLK: mitogen-activated protein kinase kinase kinase 12; MAPK8/JNK/bsk: mitogen-activated protein kinase 8/basket; MAPK8IP3/JIP3: mitogen-activated protein kinase 8 interacting protein 3; NGF: nerve growth factor; NMJ: neuromuscular junction; NTRK1/TRKA: neurotrophic receptor tyrosine kinase 1; NRTK2/TRKB: neurotrophic receptor tyrosine kinase 2; nuf: nuclear fallout; PG: phagophore; PtdIns3P: phosphatidylinositol-3-phosphate; puc: puckered; ref(2)P: refractory to sigma P; Rilpl: Rab interacting lysosomal protein like; Rip11: Rab11 interacting protein; RTN1: reticulon 1; syd: sunday driver; SYP: synaptophysin; SYT1/Syt1: synaptotagmin 1; STX17/Syx17: syntaxin 17; tkv: thickveins; VF: vesicle fraction; wit: wishful thinking; wnd: wallenda.
Collapse
Affiliation(s)
- Thomas J. Krzystek
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Joseph A. White
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Rasika Rathnayake
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Layne Thurston
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Hayley Hoffmar-Glennon
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Yichen Li
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| |
Collapse
|
7
|
Tandon S, Sarkar S. Glipizide ameliorates human poly(Q) mediated neurotoxicity by upregulating insulin signalling in Drosophila disease models. Biochem Biophys Res Commun 2023; 645:88-96. [PMID: 36680941 DOI: 10.1016/j.bbrc.2023.01.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Increasing reports suggest insulin signalling pathway as a putative drug target against polyglutamine [poly(Q)] disorders, such as Huntington's disease (HD), Spinocerebellar ataxias (SCA) 1, 2, 3 etc. However, studies on drug-based stimulation of insulin signalling cascade to mitigate poly(Q) pathogenesis are lacking. In our study, we adopted an evidence-based approach to examine if some established insulin stimulating drug can be utilized to restrict poly(Q) aetiology in Drosophila disease models. For the first time, we report that glipizide, an FDA approved anti-diabetic drug upregulates insulin signalling in poly(Q) expressing tissues and restricts formation of inclusion bodies and neurodegeneration. Moreover, it reinstates the chromatin architecture by improving histone acetylation, which is otherwise abrogated due to poly(Q) toxicity. In view of the functional conservation of insulin signalling pathway in Drosophila and humans, our finding strongly suggests that glipizide can be repurposed as an effective treatment strategy against the neurodegenerative poly(Q) disorders. Also, with appropriate validation studies in mammalian disease models, glipizide could be subsequently considered for the clinical trials in human patients.
Collapse
Affiliation(s)
- Shweta Tandon
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India.
| |
Collapse
|
8
|
Merino M, Sequedo MD, Sánchez-Sánchez AV, Clares MP, García-España E, Vázquez-Manrique RP, Mullor JL. Mn(II) Quinoline Complex (4QMn) Restores Proteostasis and Reduces Toxicity in Experimental Models of Huntington's Disease. Int J Mol Sci 2022; 23:8936. [PMID: 36012207 PMCID: PMC9409211 DOI: 10.3390/ijms23168936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 12/04/2022] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, of the so-called minority diseases, due to its low prevalence. It is caused by an abnormally long track of glutamines (polyQs) in mutant huntingtin (mHtt), which makes the protein toxic and prone to aggregation. Many pathways of clearance of badly-folded proteins are disrupted in neurons of patients with HD. In this work, we show that one Mn(II) quinone complex (4QMn), designed to work as an artificial superoxide dismutase, is able to activate both the ubiquitin-proteasome system and the autophagy pathway in vitro and in vivo models of HD. Activation of these pathways degrades mHtt and other protein-containing polyQs, which restores proteostasis in these models. Hence, we propose 4QMn as a potential drug to develop a therapy to treat HD.
Collapse
Affiliation(s)
- Marián Merino
- Bionos Biotech SL, Biopolo Hospital La Fe, 46026 Valencia, Spain
| | - María Dolores Sequedo
- Laboratory of Molecular, Cellular and Genomic Biomedicine, Instituto de Investigación Sanitaria La Fe, 46026 Valencia, Spain
| | | | - Mª Paz Clares
- Departamento de Química Orgánica e Inorgánica, Instituto de Ciencia Molecular, Universidad de Valencia, 46980 Valencia, Spain
| | - Enrique García-España
- Departamento de Química Orgánica e Inorgánica, Instituto de Ciencia Molecular, Universidad de Valencia, 46980 Valencia, Spain
| | - Rafael P. Vázquez-Manrique
- Laboratory of Molecular, Cellular and Genomic Biomedicine, Instituto de Investigación Sanitaria La Fe, 46026 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
- Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012 Valencia, Spain
| | - José L. Mullor
- Bionos Biotech SL, Biopolo Hospital La Fe, 46026 Valencia, Spain
| |
Collapse
|
9
|
Vela M, García-Gimeno MA, Sanchis A, Bono-Yagüe J, Cumella J, Lagartera L, Pérez C, Priego EM, Campos A, Sanz P, Vázquez-Manrique RP, Castro A. Neuroprotective Effect of IND1316, an Indole-Based AMPK Activator, in Animal Models of Huntington Disease. ACS Chem Neurosci 2022; 13:275-287. [PMID: 34962383 DOI: 10.1021/acschemneuro.1c00758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aggregation of mutant huntingtin, because of an expanded polyglutamine track, underlies the cause of neurodegeneration in Huntington disease (HD). However, it remains unclear how some alterations at the cellular level lead to specific structural changes in HD brains. In this context, the neuroprotective effect of the activation of AMP-activated protein kinase (AMPK) appears to be a determinant factor in several neurodegenerative diseases, including HD. In the present work, we describe a series of indole-derived compounds able to activate AMPK at the cellular level. By using animal models of HD (both worms and mice), we demonstrate the in vivo efficacy of one of these compounds (IND1316), confirming that it can reduce the neuropathological symptoms of this disease. Taken together, in vivo results and in silico studies of druggability, allow us to suggest that IND1316 could be considered as a promising new lead compound for the treatment of HD and other central nervous system diseases in which the activation of AMPK results in neuroprotection.
Collapse
Affiliation(s)
- Marta Vela
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - María Adelaida García-Gimeno
- Department of Biotechnology, Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural (ETSIAMN), Universitat Politécnica de València, 46022 Valencia, Spain
| | - Ana Sanchis
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain
- Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012 Valencia, Spain
| | - José Bono-Yagüe
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain
- Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012 Valencia, Spain
| | - José Cumella
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - Laura Lagartera
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - Concepción Pérez
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - Eva-María Priego
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| | - Angela Campos
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)-ISCIII, 28029 Madrid, Spain
- Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)-ISCIII, 28029 Madrid, Spain
- Instituto de Biomedicina de Valencia, IBV-CSIC, 46010 Valencia, Spain
| | - Rafael P. Vázquez-Manrique
- Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026 Valencia, Spain
- Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)-ISCIII, 28029 Madrid, Spain
| | - Ana Castro
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
| |
Collapse
|
10
|
Huelsmeier J, Walker E, Bakthavachalu B, Ramaswami M. A C-terminal ataxin-2 disordered region promotes Huntingtin protein aggregation and neurodegeneration in Drosophila models of Huntington’s disease. G3 GENES|GENOMES|GENETICS 2021; 11:6385240. [PMID: 34718534 PMCID: PMC8664476 DOI: 10.1093/g3journal/jkab355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/01/2021] [Indexed: 11/15/2022]
Abstract
The Ataxin-2 (Atx2) protein contributes to the progression of neurodegenerative phenotypes in animal models of amyotrophic lateral sclerosis (ALS), type 2 spinocerebellar ataxia (SCA-2), Parkinson’s disease, and Huntington’s disease (HD). However, because the Atx2 protein contains multiple separable activities, deeper understanding requires experiments to address the exact mechanisms by which Atx2 modulates neurodegeneration (ND) progression. Recent work on two ALS models, C9ORF72 and FUS, in Drosophila has shown that a C-terminal intrinsically disordered region (cIDR) of Atx2 protein, required for assembly of ribonucleoprotein (RNP) granules, is essential for the progression of neurodegenerative phenotypes as well as for accumulation of protein inclusions associated with these ALS models. Here, we show that the Atx2-cIDR also similarly contributes to the progression of degenerative phenotypes and accumulation of Huntingtin protein aggregates in Drosophila models of HD. Because Huntingtin is not an established component of RNP granules, these observations support a recently hypothesized, unexpected protein-handling function for RNP granules, which could contribute to the progression of Huntington’s disease and, potentially, other proteinopathies.
Collapse
Affiliation(s)
- Joern Huelsmeier
- School of Genetics and Microbiology, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Emily Walker
- School of Genetics and Microbiology, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Baskar Bakthavachalu
- School of Basic Science, Indian Institute of Technology, Mandi, Suran 175075, India
| | - Mani Ramaswami
- School of Genetics and Microbiology, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
- National Centre for Biological Sciences, TIFR, Bangalore 560065, India
| |
Collapse
|
11
|
Moreira R, Mendonça LS, Pereira de Almeida L. Extracellular Vesicles Physiological Role and the Particular Case of Disease-Spreading Mechanisms in Polyglutamine Diseases. Int J Mol Sci 2021; 22:ijms222212288. [PMID: 34830171 PMCID: PMC8621536 DOI: 10.3390/ijms222212288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/16/2022] Open
Abstract
Recent research demonstrated pathological spreading of the disease-causing proteins from one focal point across other brain regions for some neurodegenerative diseases, such as Parkinson's and Alzheimer's disease. Spreading mediated by extracellular vesicles is one of the proposed disease-spreading mechanisms. Extracellular vesicles are cell membrane-derived vesicles, used by cells for cell-to-cell communication and excretion of toxic components. Importantly, extracellular vesicles carrying pathological molecules, when internalized by "healthy" cells, may trigger pathological pathways and, consequently, promote disease spreading to neighboring cells. Polyglutamine diseases are a group of genetic neurodegenerative disorders characterized by the accumulation of mutant misfolded proteins carrying an expanded tract of glutamines, including Huntington's and Machado-Joseph disease. The pathological spread of the misfolded proteins or the corresponding mutant mRNA has been explored. The understanding of the disease-spreading mechanism that plays a key role in the pathology progression of these diseases can result in the development of effective therapeutic approaches to stop disease progression, arresting the spread of the toxic components and disease aggravation. Therefore, the present review's main focus is the disease-spreading mechanisms with emphasis on polyglutamine diseases and the putative role played by extracellular vesicles in this process.
Collapse
Affiliation(s)
- Ricardo Moreira
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal;
- CIBB—Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Liliana S. Mendonça
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal;
- CIBB—Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-504 Coimbra, Portugal
- Correspondence: (L.S.M.); (L.P.d.A.); Tel.: +351-239-820-190 (L.S.M.)
| | - Luís Pereira de Almeida
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal;
- CIBB—Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
- Correspondence: (L.S.M.); (L.P.d.A.); Tel.: +351-239-820-190 (L.S.M.)
| |
Collapse
|
12
|
Peng K, Lozach PY. Rift Valley fever virus: a new avenue of research on the biological functions of amyloids? Future Virol 2021. [DOI: 10.2217/fvl-2021-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rift Valley fever is a mosquito-borne viral zoonosis that was first discovered in the Great Rift Valley, Kenya, in 1930. Rift Valley fever virus (RVFV) primarily infects domestic animals and humans, with clinical outcomes ranging from self-limiting febrile illness to acute hepatitis and encephalitis. The virus left Africa a few decades ago, and there is a risk of introduction into southern Europe and Asia. From this perspective, we introduce RVFV and focus on the capacity of its virulence factor, the nonstructural protein NSs, to form amyloid-like fibrils. Here, we discuss the implications for the NSs biological function, the ability of RVFV to evade innate immunity, and RVFV virulence and neurotoxicity.
Collapse
Affiliation(s)
- Ke Peng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, 430071, PR China
- University of the Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Pierre-Yves Lozach
- Cell Networks, CIID (Cluster of Excellence & Center for Integrative Infectious Disease Research), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
- University of Lyon, INRAE, EPHE, IVPC (Infections Virales et Pathologie Comparée), 69007, Lyon, France
| |
Collapse
|
13
|
Wu Y, Fu A, Yossifon G. Micromotor-based localized electroporation and gene transfection of mammalian cells. Proc Natl Acad Sci U S A 2021; 118:e2106353118. [PMID: 34531322 PMCID: PMC8463876 DOI: 10.1073/pnas.2106353118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2021] [Indexed: 11/18/2022] Open
Abstract
Herein, we studied localized electroporation and gene transfection of mammalian cells using a metallodielectric hybrid micromotor that is magnetically and electrically powered. Much like nanochannel-based, local electroporation of single cells, the presented micromotor was expected to increase reversible electroporation yield, relative to standard electroporation, as only a small portion of the cell's membrane (in contact with the micromotor) is affected. In contrast to methods in which the entire membrane of all cells within the sample are electroporated, the presented micromotor can perform, via magnetic steering, localized, spatially precise electroporation of the target cells that it traps and transports. In order to minimize nonselective electrical lysis of all cells within the chamber, resulting from extended exposure to an electrical field, magnetic propulsion was used to approach the immediate vicinity of the targeted cell, after which short-duration, electric-driven propulsion was activated to enable contact with the cell, followed by electroporation. In addition to local injection of fluorescent dye molecules, we demonstrated that the micromotor can enhance the introduction of plasmids into the suspension cells because of the dielectrophoretic accumulation of the plasmids in between the Janus particle and the attached cell prior to the electroporation step. Here, we chose a different strategy involving the simultaneous operation of many micromotors that are self-propelling, without external steering, and pair with cells in an autonomic manner. The locally electroporated suspension cells that are considered to be very difficult to transfect were shown to express the transfected gene, which is of significant importance for molecular biology research.
Collapse
Affiliation(s)
- Yue Wu
- Faculty of Mechanical Engineering, Micro-, and Nanofluidics Laboratory, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Afu Fu
- Technion Rappaport Integrated Cancer Center, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Gilad Yossifon
- Faculty of Mechanical Engineering, Micro-, and Nanofluidics Laboratory, Technion - Israel Institute of Technology, Haifa 32000, Israel;
| |
Collapse
|
14
|
RACK1 modulates polyglutamine-induced neurodegeneration by promoting ERK degradation in Drosophila. PLoS Genet 2021; 17:e1009558. [PMID: 33983927 PMCID: PMC8118270 DOI: 10.1371/journal.pgen.1009558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/20/2021] [Indexed: 11/19/2022] Open
Abstract
Polyglutamine diseases are neurodegenerative diseases caused by the expansion of polyglutamine (polyQ) tracts within different proteins. Although multiple pathways have been found to modulate aggregation of the expanded polyQ proteins, the mechanisms by which polyQ tracts induced neuronal cell death remain unknown. We conducted a genome-wide genetic screen to identify genes that suppress polyQ-induced neurodegeneration when mutated. Loss of the scaffold protein RACK1 alleviated cell death associated with the expression of polyQ tracts alone, as well as in models of Machado-Joseph disease (MJD) and Huntington's disease (HD), without affecting proteostasis of polyQ proteins. A genome-wide RNAi screen for modifiers of this rack1 suppression phenotype revealed that knockdown of the E3 ubiquitin ligase, POE (Purity of essence), further suppressed polyQ-induced cell death, resulting in nearly wild-type looking eyes. Biochemical analyses demonstrated that RACK1 interacts with POE and ERK to promote ERK degradation. These results suggest that RACK1 plays a key role in polyQ pathogenesis by promoting POE-dependent degradation of ERK, and implicate RACK1/POE/ERK as potent drug targets for treatment of polyQ diseases.
Collapse
|
15
|
Subhan I, Siddique YH. Modulation of Huntington's disease in Drosophila. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 20:894-903. [PMID: 33845728 DOI: 10.2174/1871527320666210412155508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 11/22/2022]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder which deteriorates the physical and mental abilities of the patients. It is an autosomal dominant disorder and is mainly caused by the expansion of a repeating CAG triplet. A number of animal models ranging from worms, fruit flies, mice and rats to pigs, sheep and monkeys are available which have been helpful in understanding various pathways involved during the progression of the disease. Drosophila is one of the most commonly used model organisms for biomedical science, due to low cost maintenance, short life span and easily implications of genetic tools. The present review provides brief description of HD and the studies carried out for HD to date taking Drosophila as a model.
Collapse
Affiliation(s)
- Iqra Subhan
- Drosophila Transgenic Laboratory, Section of Genetics, Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh-202002, Uttar Pradesh. India
| | - Yasir Hasan Siddique
- Drosophila Transgenic Laboratory, Section of Genetics, Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh-202002, Uttar Pradesh. India
| |
Collapse
|
16
|
Perrone-Capano C, Volpicelli F, Penna E, Chun JT, Crispino M. Presynaptic protein synthesis and brain plasticity: From physiology to neuropathology. Prog Neurobiol 2021; 202:102051. [PMID: 33845165 DOI: 10.1016/j.pneurobio.2021.102051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/14/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022]
Abstract
To form and maintain extremely intricate and functional neural circuitry, mammalian neurons are typically endowed with highly arborized dendrites and a long axon. The synapses that link neurons to neurons or to other cells are numerous and often too remote for the cell body to make and deliver new proteins to the right place in time. Moreover, synapses undergo continuous activity-dependent changes in their number and strength, establishing the basis of neural plasticity. The innate dilemma is then how a highly complex neuron provides new proteins for its cytoplasmic periphery and individual synapses to support synaptic plasticity. Here, we review a growing body of evidence that local protein synthesis in discrete sites of the axon and presynaptic terminals plays crucial roles in synaptic plasticity, and that deregulation of this local translation system is implicated in various pathologies of the nervous system.
Collapse
Affiliation(s)
- Carla Perrone-Capano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy; Institute of Genetics and Biophysics "Adriano Buzzati Traverso", CNR, Naples, Italy.
| | | | - Eduardo Penna
- Department of Biology, University of Naples Federico II, Naples, Italy.
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy.
| | - Marianna Crispino
- Department of Biology, University of Naples Federico II, Naples, Italy.
| |
Collapse
|
17
|
Tandon S, Sarkar S. The S6k/4E-BP mediated growth promoting sub-pathway of insulin signalling cascade is essential to restrict pathogenesis of poly(Q) disorders in Drosophila. Life Sci 2021; 275:119358. [PMID: 33744321 DOI: 10.1016/j.lfs.2021.119358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/19/2021] [Accepted: 03/06/2021] [Indexed: 01/05/2023]
Abstract
Human neurodegenerative polyglutamine [poly(Q)] disorders, such as Huntington's disease (HD) and spinocerebellar ataxias (SCA), are characterised by an abnormal expansion of CAG repeats in the affected gene. The mutated proteins misfold and aggregate to form inclusion bodies that sequester important factors involved in cellular transcription, growth, stress and autophagic response and other essential functions. The insulin signalling pathway has been demonstrated as a major modifier and a potential drug target to ameliorate the poly(Q) mediated neurotoxicity in various model systems. Insulin signalling cascade harbours several downstream sub-pathways, which are synergistically involved in discharging indispensable biological functions such as growth and proliferation, metabolism, autophagy, regulation of cell death pathways etc. Hence, it is difficult to conclude whether the mitigation of poly(Q) neurotoxicity is an accumulative outcome of the insulin cascade, or the result of a specific sub-pathway. For the first time, we report that the ligand binding domain of insulin receptor mediated downstream growth promoting sub-pathway plays the pivotal role in operating the rescue event. We show that the growth promoting activity of insulin cascade is essential to minimize the abundance of inclusion bodies, to restrict neurodegeneration, and to restore the cellular transcriptional balance. Subsequently, we noted the involvement of the mTOR/S6k/4E-BP candidates in mitigating poly(Q) mediated neurotoxicity. Due to the conserved cellular functioning of the insulin cascade across species, and availability of several growth promoting molecules, our results in Drosophila poly(Q) models indicate towards a possibility of designing novel therapeutic strategies to restrict the pathogenesis of devastating human poly(Q) disorders.
Collapse
Affiliation(s)
- Shweta Tandon
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
| |
Collapse
|
18
|
Chatterjee M, Steffan JS, Lukacsovich T, Marsh JL, Agrawal N. Serine residues 13 and 16 are key modulators of mutant huntingtin induced toxicity in Drosophila. Exp Neurol 2020; 338:113463. [PMID: 32941796 DOI: 10.1016/j.expneurol.2020.113463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/07/2020] [Indexed: 10/23/2022]
Abstract
Poly-glutamine expansion near the N-terminus of the huntingtin protein (HTT) is the prime determinant of Huntington's disease (HD) pathology; however, post-translational modifications and protein context are also reported to influence poly-glutamine induced HD toxicity. The impact of phosphorylating serine 13/16 of mutant HTT (mHTT) on HD has been documented in cell culture and murine models. However, endogenous processing of the human protein in mammalian systems complicates the interpretations. Therefore, to study the impact of S13/16 phosphorylation on the subcellular behavior of HTT under a controlled genetic background with minimal proteolytic processing of the human protein, we employed Drosophila as the model system. We ectopically expressed full-length (FL) and exon1 fragment of human HTT with phosphomimetic and resistant mutations at serines 13 and 16 in different neuronal populations. Phosphomimetic mHTT aggravates and the phosphoresistant mutation ameliorates mHTT-induced toxicity in the context of both FL- and exon1- mHTT in Drosophila although in all cases FL appears less toxic than exon1. Our observations strongly indicate that the phosphorylation status of S13/16 can affect HD pathology in Drosophila and these residues can be potential targets for affecting HD pathogenesis.
Collapse
Affiliation(s)
- Megha Chatterjee
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Joan S Steffan
- Department of Psychiatry and Human Behavior, University of California Irvine, Irvine, CA 92697-1705, USA
| | - Tamas Lukacsovich
- Brain Research Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697-2300, USA
| | - Namita Agrawal
- Department of Zoology, University of Delhi, Delhi, 110007, India.
| |
Collapse
|
19
|
Joag H, Ghatpande V, Desai M, Sarkar M, Raina A, Shinde M, Chitale R, Deo A, Bose T, Majumdar A. A role of cellular translation regulation associated with toxic Huntingtin protein. Cell Mol Life Sci 2020; 77:3657-3670. [PMID: 31796991 PMCID: PMC11105026 DOI: 10.1007/s00018-019-03392-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022]
Abstract
Huntington's disease (HD) is a severe neurodegenerative disorder caused by poly Q repeat expansion in the Huntingtin (Htt) gene. While the Htt amyloid aggregates are known to affect many cellular processes, their role in translation has not been addressed. Here we report that pathogenic Htt expression causes a protein synthesis deficit in cells. We find a functional prion-like protein, the translation regulator Orb2, to be sequestered by Htt aggregates in cells. Co-expression of Orb2 can partially rescue the lethality associated with poly Q expanded Htt. These findings can be relevant for HD as human homologs of Orb2 are also sequestered by pathogenic Htt aggregates. Our work suggests that translation dysfunction is one of the contributors to the pathogenesis of HD and new therapies targeting protein synthesis pathways might help to alleviate disease symptoms.
Collapse
Affiliation(s)
- Hiranmay Joag
- National Centre for Cell Science, S. P. Pune University, Pune, India
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | | | - Meghal Desai
- National Centre for Cell Science, S. P. Pune University, Pune, India
| | - Maitheli Sarkar
- National Centre for Cell Science, S. P. Pune University, Pune, India
| | - Anshu Raina
- National Centre for Cell Science, S. P. Pune University, Pune, India
| | - Mrunalini Shinde
- Institute of Bioinformatics and Biotechnology, S. P. Pune University, Pune, India
| | - Ruta Chitale
- Institute of Bioinformatics and Biotechnology, S. P. Pune University, Pune, India
| | - Ankita Deo
- Institute of Bioinformatics and Biotechnology, S. P. Pune University, Pune, India
| | - Tania Bose
- Institute of Bioinformatics and Biotechnology, S. P. Pune University, Pune, India.
| | - Amitabha Majumdar
- National Centre for Cell Science, S. P. Pune University, Pune, India.
| |
Collapse
|
20
|
White JA, Krzystek TJ, Hoffmar-Glennon H, Thant C, Zimmerman K, Iacobucci G, Vail J, Thurston L, Rahman S, Gunawardena S. Excess Rab4 rescues synaptic and behavioral dysfunction caused by defective HTT-Rab4 axonal transport in Huntington's disease. Acta Neuropathol Commun 2020; 8:97. [PMID: 32611447 PMCID: PMC7331280 DOI: 10.1186/s40478-020-00964-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/11/2020] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is characterized by protein inclusions and loss of striatal neurons which result from expanded CAG repeats in the poly-glutamine (polyQ) region of the huntingtin (HTT) gene. Both polyQ expansion and loss of HTT have been shown to cause axonal transport defects. While studies show that HTT is important for vesicular transport within axons, the cargo that HTT transports to/from synapses remain elusive. Here, we show that HTT is present with a class of Rab4-containing vesicles within axons in vivo. Reduction of HTT perturbs the bi-directional motility of Rab4, causing axonal and synaptic accumulations. In-vivo dual-color imaging reveal that HTT and Rab4 move together on a unique putative vesicle that may also contain synaptotagmin, synaptobrevin, and Rab11. The moving HTT-Rab4 vesicle uses kinesin-1 and dynein motors for its bi-directional movement within axons, as well as the accessory protein HIP1 (HTT-interacting protein 1). Pathogenic HTT disrupts the motility of HTT-Rab4 and results in larval locomotion defects, aberrant synaptic morphology, and decreased lifespan, which are rescued by excess Rab4. Consistent with these observations, Rab4 motility is perturbed in iNeurons derived from human Huntington's Disease (HD) patients, likely due to disrupted associations between the polyQ-HTT-Rab4 vesicle complex, accessory proteins, and molecular motors. Together, our observations suggest the existence of a putative moving HTT-Rab4 vesicle, and that the axonal motility of this vesicle is disrupted in HD causing synaptic and behavioral dysfunction. These data highlight Rab4 as a potential novel therapeutic target that could be explored for early intervention prior to neuronal loss and behavioral defects observed in HD.
Collapse
Affiliation(s)
- Joseph A. White
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Thomas J. Krzystek
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Hayley Hoffmar-Glennon
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Claire Thant
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Katherine Zimmerman
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Gary Iacobucci
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Julia Vail
- Department of Biological Engineering, Cornell University, Ithaca, NY USA
| | - Layne Thurston
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Saad Rahman
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| | - Shermali Gunawardena
- Department of Biological Sciences, The State University of New York at Buffalo, New York, 14260 USA
| |
Collapse
|
21
|
Léger P, Nachman E, Richter K, Tamietti C, Koch J, Burk R, Kummer S, Xin Q, Stanifer M, Bouloy M, Boulant S, Kräusslich HG, Montagutelli X, Flamand M, Nussbaum-Krammer C, Lozach PY. NSs amyloid formation is associated with the virulence of Rift Valley fever virus in mice. Nat Commun 2020; 11:3281. [PMID: 32612175 PMCID: PMC7329897 DOI: 10.1038/s41467-020-17101-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 06/13/2020] [Indexed: 12/22/2022] Open
Abstract
Amyloid fibrils result from the aggregation of host cell-encoded proteins, many giving rise to specific human illnesses such as Alzheimer’s disease. Here we show that the major virulence factor of Rift Valley fever virus, the protein NSs, forms filamentous structures in the brain of mice and affects mortality. NSs assembles into nuclear and cytosolic disulfide bond-dependent fibrillary aggregates in infected cells. NSs structural arrangements exhibit characteristics typical for amyloids, such as an ultrastructure of 12 nm-width fibrils, a strong detergent resistance, and interactions with the amyloid-binding dye Thioflavin-S. The assembly dynamics of viral amyloid-like fibrils can be visualized in real-time. They form spontaneously and grow in an amyloid fashion within 5 hours. Together, our results demonstrate that viruses can encode amyloid-like fibril-forming proteins and have strong implications for future research on amyloid aggregation and toxicity in general. Rift Valley fever virus (RVFV) can cause severe diseases in humans, including encephalitis. Here the authors show that NSs, the major virulence factor of RVFV, is an amyloidogenic protein forming fibrils in infected mouse brains and causing increased mortality in mice.
Collapse
Affiliation(s)
- Psylvia Léger
- CellNetworks-Cluster of Excellence and Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany.,Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Eliana Nachman
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | | | | | - Jana Koch
- CellNetworks-Cluster of Excellence and Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany.,Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Robin Burk
- Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Susann Kummer
- Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | - Qilin Xin
- University Lyon, INRAE, EPHE, IVPC, 69007, Lyon, France
| | - Megan Stanifer
- Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany.,DKFZ, 69120, Heidelberg, Germany
| | - Michèle Bouloy
- Unité de Génétique Moléculaire des Bunyavirus, Institut Pasteur, 75015, Paris, France
| | - Steeve Boulant
- Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany.,DKFZ, 69120, Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
| | | | - Marie Flamand
- Structural Virology, Institut Pasteur, 75015, Paris, France
| | - Carmen Nussbaum-Krammer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Pierre-Yves Lozach
- CellNetworks-Cluster of Excellence and Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany. .,Center for Integrative Infectious Diseases Research (CIID), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany. .,University Lyon, INRAE, EPHE, IVPC, 69007, Lyon, France.
| |
Collapse
|
22
|
Wilton DK, Stevens B. The contribution of glial cells to Huntington's disease pathogenesis. Neurobiol Dis 2020; 143:104963. [PMID: 32593752 DOI: 10.1016/j.nbd.2020.104963] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 05/07/2020] [Accepted: 06/10/2020] [Indexed: 12/20/2022] Open
Abstract
Glial cells play critical roles in the normal development and function of neural circuits, but in many neurodegenerative diseases, they become dysregulated and may contribute to the development of brain pathology. In Huntington's disease (HD), glial cells both lose normal functions and gain neuropathic phenotypes. In addition, cell-autonomous dysfunction elicited by mutant huntingtin (mHTT) expression in specific glial cell types is sufficient to induce both pathology and Huntington's disease-related impairments in motor and cognitive performance, suggesting that these cells may drive the development of certain aspects of Huntington's disease pathogenesis. In support of this imaging studies in pre-symptomatic HD patients and work on mouse models have suggested that glial cell dysfunction occurs at a very early stage of the disease, prior to the onset of motor and cognitive deficits. Furthermore, selectively ablating mHTT from specific glial cells or correcting for HD-induced changes in their transcriptional profile rescues some HD-related phenotypes, demonstrating the potential of targeting these cells for therapeutic intervention. Here we review emerging research focused on understanding the involvement of different glial cell types in specific aspects of HD pathogenesis. This work is providing new insight into how HD impacts biological functions of glial cells in the healthy brain as well as how HD induced dysfunction in these cells might change the way they integrate into biological circuits.
Collapse
Affiliation(s)
- Daniel K Wilton
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Beth Stevens
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Stanley Center, Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
23
|
Donnelly KM, DeLorenzo OR, Zaya ADA, Pisano GE, Thu WM, Luo L, Kopito RR, Panning Pearce MM. Phagocytic glia are obligatory intermediates in transmission of mutant huntingtin aggregates across neuronal synapses. eLife 2020; 9:e58499. [PMID: 32463364 PMCID: PMC7297539 DOI: 10.7554/elife.58499] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence supports the hypothesis that pathogenic protein aggregates associated with neurodegenerative diseases spread from cell to cell through the brain in a manner akin to infectious prions. Here, we show that mutant huntingtin (mHtt) aggregates associated with Huntington disease transfer anterogradely from presynaptic to postsynaptic neurons in the adult Drosophila olfactory system. Trans-synaptic transmission of mHtt aggregates is inversely correlated with neuronal activity and blocked by inhibiting caspases in presynaptic neurons, implicating synaptic dysfunction and cell death in aggregate spreading. Remarkably, mHtt aggregate transmission across synapses requires the glial scavenger receptor Draper and involves a transient visit to the glial cytoplasm, indicating that phagocytic glia act as obligatory intermediates in aggregate spreading between synaptically-connected neurons. These findings expand our understanding of phagocytic glia as double-edged players in neurodegeneration-by clearing neurotoxic protein aggregates, but also providing an opportunity for prion-like seeds to evade phagolysosomal degradation and propagate further in the brain.
Collapse
Affiliation(s)
- Kirby M Donnelly
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Olivia R DeLorenzo
- Program in Neuroscience, University of the SciencesPhiladelphiaUnited States
| | - Aprem DA Zaya
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Gabrielle E Pisano
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Wint M Thu
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
| | - Liqun Luo
- Department of Biology, Stanford UniversityStanfordUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Ron R Kopito
- Department of Biology, Stanford UniversityStanfordUnited States
| | - Margaret M Panning Pearce
- Department of Biological Sciences, University of the SciencesPhiladelphiaUnited States
- Program in Neuroscience, University of the SciencesPhiladelphiaUnited States
| |
Collapse
|
24
|
Lin YH, Maaroufi HO, Ibrahim E, Kucerova L, Zurovec M. Expression of Human Mutant Huntingtin Protein in Drosophila Hemocytes Impairs Immune Responses. Front Immunol 2019; 10:2405. [PMID: 31681295 PMCID: PMC6805700 DOI: 10.3389/fimmu.2019.02405] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/25/2019] [Indexed: 01/30/2023] Open
Abstract
The pathogenic effect of mutant HTT (mHTT) which causes Huntington disease (HD) are not restricted to nervous system. Such phenotypes include aberrant immune responses observed in the HD models. However, it is still unclear how this immune dysregulation influences the innate immune response against pathogenic infection. In the present study, we used transgenic Drosophila melanogaster expressing mutant HTT protein (mHTT) with hemocyte-specific drivers and examined the immune responses and hemocyte function. We found that mHTT expression in the hemocytes did not affect fly viability, but the numbers of circulating hemocytes were significantly decreased. Consequently, we observed that the expression of mHTT in the hemocytes compromised the immune responses including clot formation and encapsulation which lead to the increased susceptibility to entomopathogenic nematode and parasitoid wasp infections. In addition, mHTT expression in Drosophila macrophage-like S2 cells in vitro reduced ATP levels, phagocytic activity and the induction of antimicrobial peptides. Further effects observed in mHTT-expressing cells included the altered production of cytokines and activation of JAK/STAT signaling. The present study shows that the expression of mHTT in Drosophila hemocytes causes deficient cellular and humoral immune responses against invading pathogens. Our findings provide the insight into the pathogenic effects of mHTT in the immune cells.
Collapse
Affiliation(s)
- Yu-Hsien Lin
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czechia.,Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia
| | - Houda Ouns Maaroufi
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czechia.,Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia
| | - Emad Ibrahim
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czechia.,Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia
| | - Lucie Kucerova
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czechia
| | - Michal Zurovec
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czechia.,Faculty of Science, University of South Bohemia, Ceske Budejovice, Czechia
| |
Collapse
|
25
|
Xu F, Kula-Eversole E, Iwanaszko M, Lim C, Allada R. Ataxin2 functions via CrebA to mediate Huntingtin toxicity in circadian clock neurons. PLoS Genet 2019; 15:e1008356. [PMID: 31593562 PMCID: PMC6782096 DOI: 10.1371/journal.pgen.1008356] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/07/2019] [Indexed: 12/12/2022] Open
Abstract
Disrupted circadian rhythms is a prominent and early feature of neurodegenerative diseases including Huntington’s disease (HD). In HD patients and animal models, striatal and hypothalamic neurons expressing molecular circadian clocks are targets of mutant Huntingtin (mHtt) pathogenicity. Yet how mHtt disrupts circadian rhythms remains unclear. In a genetic screen for modifiers of mHtt effects on circadian behavior in Drosophila, we discovered a role for the neurodegenerative disease gene Ataxin2 (Atx2). Genetic manipulations of Atx2 modify the impact of mHtt on circadian behavior as well as mHtt aggregation and demonstrate a role for Atx2 in promoting mHtt aggregation as well as mHtt-mediated neuronal dysfunction. RNAi knockdown of the Fragile X mental retardation gene, dfmr1, an Atx2 partner, also partially suppresses mHtt effects and Atx2 effects depend on dfmr1. Atx2 knockdown reduces the cAMP response binding protein A (CrebA) transcript at dawn. CrebA transcript level shows a prominent diurnal regulation in clock neurons. Loss of CrebA also partially suppresses mHtt effects on behavior and cell loss and restoration of CrebA can suppress Atx2 effects. Our results indicate a prominent role of Atx2 in mediating mHtt pathology, specifically via its regulation of CrebA, defining a novel molecular pathway in HD pathogenesis. Circadian clocks evolved to anticipate 24 h environmental rhythms driven by the earth’s daily rotation and regulate nearly all aspects of behavior, physiology and the genome. Disruptions of the circadian clock have been associated with a wide range of human diseases, including neurodegenerative diseases such as Huntington’s disease (HD). Using an HD animal model in which a mutant Huntingtin (mHtt) protein is expressed, we identify a role for the RNA binding protein and neurodegenerative disease gene Ataxin-2 (Atx2) in mediating mHtt effects on circadian behavioral rhythms. Using transcriptomics, we identify the transcription factor CrebA as a potential target of both Atx2 and the circadian clock. Finally, we demonstrate a role for CrebA in mediating mHtt effects on circadian behavior, defining a novel Atx2-CrebA pathway in a neurodegenerative disease model. These studies define the molecular mechanisms by which mHtt can disrupt circadian rhythms identifying potential novel therapeutic targets for this uniformly fatal disease.
Collapse
Affiliation(s)
- Fangke Xu
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Elzbieta Kula-Eversole
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Marta Iwanaszko
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Chunghun Lim
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
| |
Collapse
|
26
|
Nmnat restores neuronal integrity by neutralizing mutant Huntingtin aggregate-induced progressive toxicity. Proc Natl Acad Sci U S A 2019; 116:19165-19175. [PMID: 31484760 DOI: 10.1073/pnas.1904563116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accumulative aggregation of mutant Huntingtin (Htt) is a primary neuropathological hallmark of Huntington's disease (HD). Currently, mechanistic understanding of the cytotoxicity of mutant Htt aggregates remains limited, and neuroprotective strategies combating mutant Htt-induced neurodegeneration are lacking. Here, we show that in Drosophila models of HD, neuronal compartment-specific accumulation of mutant Htt aggregates causes neurodegenerative phenotypes. In addition to the increase in the number and size, we discovered an age-dependent acquisition of thioflavin S+, amyloid-like adhesive properties of mutant Htt aggregates and a concomitant progressive clustering of aggregates with mitochondria and synaptic proteins, indicating that the amyloid-like adhesive property underlies the neurotoxicity of mutant Htt aggregation. Importantly, nicotinamide mononucleotide adenylyltransferase (NMNAT), an evolutionarily conserved nicotinamide adenine dinucleotide (NAD+) synthase and neuroprotective factor, significantly mitigates mutant Htt-induced neurodegeneration by reducing mutant Htt aggregation through promoting autophagic clearance. Additionally, Nmnat overexpression reduces progressive accumulation of amyloid-like Htt aggregates, neutralizes adhesiveness, and inhibits the clustering of mutant Htt with mitochondria and synaptic proteins, thereby restoring neuronal function. Conversely, partial loss of endogenous Nmnat exacerbates mutant Htt-induced neurodegeneration through enhancing mutant Htt aggregation and adhesive property. Finally, conditional expression of Nmnat after the onset of degenerative phenotypes significantly delays the progression of neurodegeneration, revealing the therapeutic potential of Nmnat-mediated neuroprotection at advanced stages of HD. Our study uncovers essential mechanistic insights to the neurotoxicity of mutant Htt aggregation and describes the molecular basis of Nmnat-mediated neuroprotection in HD.
Collapse
|
27
|
Rodriguez-Fernandez IA, Qi Y, Jasper H. Loss of a proteostatic checkpoint in intestinal stem cells contributes to age-related epithelial dysfunction. Nat Commun 2019; 10:1050. [PMID: 30837466 PMCID: PMC6401111 DOI: 10.1038/s41467-019-08982-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/09/2019] [Indexed: 01/08/2023] Open
Abstract
A decline in protein homeostasis (proteostasis) has been proposed as a hallmark of aging. Somatic stem cells (SCs) uniquely maintain their proteostatic capacity through mechanisms that remain incompletely understood. Here, we describe and characterize a ‘proteostatic checkpoint’ in Drosophila intestinal SCs (ISCs). Following a breakdown of proteostasis, ISCs coordinate cell cycle arrest with protein aggregate clearance by Atg8-mediated activation of the Nrf2-like transcription factor cap-n-collar C (CncC). CncC induces the cell cycle inhibitor Dacapo and proteolytic genes. The capacity to engage this checkpoint is lost in ISCs from aging flies, and we show that it can be restored by treating flies with an Nrf2 activator, or by over-expression of CncC or Atg8a. This limits age-related intestinal barrier dysfunction and can result in lifespan extension. Our findings identify a new mechanism by which somatic SCs preserve proteostasis, and highlight potential intervention strategies to maintain regenerative homeostasis. Protein homeostasis maintenance (proteostasis) is critical for cell function, but declines during aging. Here the authors detail a proteostatic checkpoint in Drosophila intestinal stem cells coordinating cell cycle arrest with protein aggregate clearance, along with its role in aging related intestinal dysfunction.
Collapse
Affiliation(s)
- Imilce A Rodriguez-Fernandez
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA.,Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Yanyan Qi
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA
| | - Heinrich Jasper
- Buck Institute for Research on Aging, 8001 Redwood Boulevard, Novato, CA, 94945-1400, USA. .,Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, California, 94080, USA. .,Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, 07745, Germany.
| |
Collapse
|
28
|
Bason M, Meister-Broekema M, Alberts N, Dijkers P, Bergink S, Sibon OCM, Kampinga HH. Astrocytic expression of the chaperone DNAJB6 results in non-cell autonomous protection in Huntington's disease. Neurobiol Dis 2018; 124:108-117. [PMID: 30408590 DOI: 10.1016/j.nbd.2018.10.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 10/02/2018] [Accepted: 10/28/2018] [Indexed: 01/02/2023] Open
Abstract
Several neurodegenerative diseases like Huntington's, a polyglutamine (PolyQ) disease, are initiated by protein aggregation in neurons. Furthermore, these diseases are also associated with a multitude of responses in non-neuronal cells in the brain, in particular glial cells, like astrocytes. These non-neuronal responses have repeatedly been suggested to play a disease-modulating role, but how these may be exploited to delay the progression of neurodegeneration has remained unclear. Interestingly, one of the molecular changes that astrocytes undergo includes the upregulation of certain Heat Shock Proteins (HSPs) that are classically considered to maintain protein homeostasis, thus resulting in cell autonomous protection. Previously, we discovered DNAJB6, a member of the human DNAJ family, as potent cell autonomous suppressor of PolyQ aggregation and related neurodegeneration. Using cell type specific expression systems in D. melanogaster, we show that exclusive expression of DNAJB6 in astrocytes (that do not express PolyQ protein) can delay neurodegeneration and expands lifespan when the PolyQ protein is exclusively expressed in neurons (that do not co-express DNAJB6 themselves). This provides direct evidence for a non-cell autonomous protective role of astrocytes in PolyQ diseases.
Collapse
Affiliation(s)
- Matteo Bason
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Melanie Meister-Broekema
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Niels Alberts
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Pascale Dijkers
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Steven Bergink
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Ody C M Sibon
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Harm H Kampinga
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands.
| |
Collapse
|
29
|
Drombosky KW, Rode S, Kodali R, Jacob TC, Palladino MJ, Wetzel R. Mutational analysis implicates the amyloid fibril as the toxic entity in Huntington's disease. Neurobiol Dis 2018; 120:126-138. [PMID: 30171891 DOI: 10.1016/j.nbd.2018.08.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 10/28/2022] Open
Abstract
In Huntington disease (HD), an expanded polyglutamine (polyQ > 37) sequence within huntingtin (htt) exon1 leads to enhanced disease risk. It has proved difficult, however, to determine whether the toxic form generated by polyQ expansion is a misfolded or avid-binding monomer, an α-helix-rich oligomer, or a β-sheet-rich amyloid fibril. Here we describe an engineered htt exon1 analog featuring a short polyQ sequence that nonetheless quickly forms amyloid fibrils and causes HD-like toxicity in rat neurons and Drosophila. Additional modifications within the polyQ segment produce htt exon1 analogs that populate only spherical oligomers and are non-toxic in cells and flies. Furthermore, in mixture with expanded-polyQ htt exon1, the latter analogs in vitro suppress amyloid formation and promote oligomer formation, and in vivo rescue neurons and flies expressing mhtt exon1 from dysfunction and death. Thus, in our experiments, while htt exon1 toxicity tracks with aggregation propensity, it does so in spite of the toxic construct's possessing polyQ tracts well below those normally considered to be disease-associated. That is, aggregation propensity proves to be a more accurate surrogate for toxicity than is polyQ repeat length itself, strongly supporting a major toxic role for htt exon1 aggregation in HD. In addition, the results suggest that the aggregates that are most toxic in these model systems are amyloid-related. These engineered analogs are novel tools for mapping properties of polyQ self-assembly intermediates and products that should similarly be useful in the analysis of other expanded polyQ diseases. Small molecules with similar amyloid inhibitory properties might be developed into effective therapeutic agents.
Collapse
Affiliation(s)
- Kenneth W Drombosky
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sascha Rode
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ravi Kodali
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Michael J Palladino
- Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ronald Wetzel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA; Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| |
Collapse
|
30
|
Rosas-Arellano A, Estrada-Mondragón A, Piña R, Mantellero CA, Castro MA. The Tiny Drosophila Melanogaster for the Biggest Answers in Huntington's Disease. Int J Mol Sci 2018; 19:E2398. [PMID: 30110961 PMCID: PMC6121572 DOI: 10.3390/ijms19082398] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/08/2018] [Accepted: 08/09/2018] [Indexed: 12/18/2022] Open
Abstract
The average life expectancy for humans has increased over the last years. However, the quality of the later stages of life is low and is considered a public health issue of global importance. Late adulthood and the transition into the later stage of life occasionally leads to neurodegenerative diseases that selectively affect different types of neurons and brain regions, producing motor dysfunctions, cognitive impairment, and psychiatric disorders that are progressive, irreversible, without remission periods, and incurable. Huntington's disease (HD) is a common neurodegenerative disorder. In the 25 years since the mutation of the huntingtin (HTT) gene was identified as the molecule responsible for this neural disorder, a variety of animal models, including the fruit fly, have been used to study the disease. Here, we review recent research that used Drosophila as an experimental tool for improving knowledge about the molecular and cellular mechanisms underpinning HD.
Collapse
Affiliation(s)
- Abraham Rosas-Arellano
- Unidad de Imagenología, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
| | - Argel Estrada-Mondragón
- Department of Clinical and Experimental Medicine, Linköping University, 581 83 Linköping, Sweden.
| | - Ricardo Piña
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile.
- Departamento de Ciencias Químicas y Biológicas, Universidad Bernardo O'Higgins, Santiago 8370993, Chile.
| | - Carola A Mantellero
- Facultad de Ciencias de la Salud, Universidad de Las Américas, Santiago 7500972, Chile.
| | - Maite A Castro
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia 5090000, Chile.
- Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia 5090000, Chile.
| |
Collapse
|
31
|
Brazill JM, Zhu Y, Li C, Zhai RG. Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ. J Vis Exp 2018:58041. [PMID: 30124668 PMCID: PMC6126610 DOI: 10.3791/58041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal dysfunction and loss. Fluorescence-based imaging tools and technologies enable unprecedented analysis of subcellular neurobiological processes, yet there is still a need for unbiased, reproducible, and accessible approaches for extracting quantifiable data from imaging studies. We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-based imaging studies using Drosophila models of neurodegeneration. Specifically, we describe an easy-to-follow, semi-automated approach using Fiji/ImageJ to analyze two cellular processes: first, we quantify protein aggregate content and profile in the Drosophila optic lobe using fluorescent-tagged mutant huntingtin proteins; and second, we assess autophagy-lysosome flux in the Drosophila visual system with ratiometric-based quantification of a tandem fluorescent reporter of autophagy. Importantly, the protocol outlined here includes a semi-automated segmentation step to ensure all fluorescent structures are analyzed to minimize selection bias and to increase resolution of subtle comparisons. This approach can be extended for the analysis of other cell biological structures and processes implicated in neurodegeneration, such as proteinaceous puncta (stress granules and synaptic complexes), as well as membrane-bound compartments (mitochondria and membrane trafficking vesicles). This method provides a standardized, yet adaptable reference point for image analysis and quantification, and could facilitate reliability and reproducibility across the field, and ultimately enhance mechanistic understanding of neurodegeneration.
Collapse
Affiliation(s)
- Jennifer M Brazill
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine
| | - Yi Zhu
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine
| | - Chong Li
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine
| | - R Grace Zhai
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine; School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University;
| |
Collapse
|
32
|
Tissue-Specific Upregulation of Drosophila Insulin Receptor (InR) Mitigates Poly(Q)-Mediated Neurotoxicity by Restoration of Cellular Transcription Machinery. Mol Neurobiol 2018; 56:1310-1329. [DOI: 10.1007/s12035-018-1160-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 05/29/2018] [Indexed: 12/11/2022]
|
33
|
RNA Aptamers Rescue Mitochondrial Dysfunction in a Yeast Model of Huntington's Disease. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 12:45-56. [PMID: 30195782 PMCID: PMC6023792 DOI: 10.1016/j.omtn.2018.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 03/27/2018] [Accepted: 04/25/2018] [Indexed: 01/27/2023]
Abstract
Huntington’s disease (HD) is associated with the misfolding and aggregation of mutant huntingtin harboring an elongated polyglutamine stretch at its N terminus. A distinguishing pathological hallmark of HD is mitochondrial dysfunction. Any strategy that can restore the integrity of the mitochondrial environment should have beneficial consequences for the disease. Specific RNA aptamers were selected that were able to inhibit aggregation of elongated polyglutamine stretch containing mutant huntingtin fragment (103Q-htt). They were successful in reducing the calcium overload, which leads to mitochondrial membrane depolarization in case of HD. In one case, the level of Ca2+ was restored to the level of cells not expressing 103Q-htt, suggesting complete recovery. The presence of aptamers was able to increase mitochondrial mass in cells expressing 103Q-htt, along with rescuing loss of mitochondrial genome. The oxidative damage to the proteome was prevented, which led to increased viability of cells, as monitored by flow cytometry. Thus, the presence of aptamers was able to inhibit aggregation of mutant huntingtin fragment and restore mitochondrial dysfunction in the HD cell model, confirming the advantage of the strategy in a disease-relevant parameter.
Collapse
|
34
|
Koon AC, Chan HYE. Drosophila melanogaster As a Model Organism to Study RNA Toxicity of Repeat Expansion-Associated Neurodegenerative and Neuromuscular Diseases. Front Cell Neurosci 2017; 11:70. [PMID: 28377694 PMCID: PMC5359753 DOI: 10.3389/fncel.2017.00070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/27/2017] [Indexed: 12/14/2022] Open
Abstract
For nearly a century, the fruit fly, Drosophila melanogaster, has proven to be a valuable tool in our understanding of fundamental biological processes, and has empowered our discoveries, particularly in the field of neuroscience. In recent years, Drosophila has emerged as a model organism for human neurodegenerative and neuromuscular disorders. In this review, we highlight a number of recent studies that utilized the Drosophila model to study repeat-expansion associated diseases (READs), such as polyglutamine diseases, fragile X-associated tremor/ataxia syndrome (FXTAS), myotonic dystrophy type 1 (DM1) and type 2 (DM2), and C9ORF72-associated amyotrophic lateral sclerosis/frontotemporal dementia (C9-ALS/FTD). Discoveries regarding the possible mechanisms of RNA toxicity will be focused here. These studies demonstrate Drosophila as an excellent in vivo model system that can reveal novel mechanistic insights into human disorders, providing the foundation for translational research and therapeutic development.
Collapse
Affiliation(s)
- Alex C Koon
- Laboratory of Drosophila ResearchHong Kong, Hong Kong; Biochemistry ProgramHong Kong, Hong Kong
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila ResearchHong Kong, Hong Kong; Biochemistry ProgramHong Kong, Hong Kong; Cell and Molecular Biology ProgramHong Kong, Hong Kong; Molecular Biotechnology Program, Faculty of Science, School of Life SciencesHong Kong, Hong Kong; School of Life Sciences, Gerald Choa Neuroscience Centre, The Chinese University of Hong KongHong Kong, Hong Kong
| |
Collapse
|
35
|
Transactivation Domain of Human c-Myc Is Essential to Alleviate Poly(Q)-Mediated Neurotoxicity in Drosophila Disease Models. J Mol Neurosci 2017; 62:55-66. [PMID: 28316031 DOI: 10.1007/s12031-017-0910-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/08/2017] [Indexed: 10/19/2022]
Abstract
Polyglutamine (poly(Q)) disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, represent a group of neurological disorders which arise due to an atypically expanded poly(Q) tract in the coding region of the affected gene. Pathogenesis of these disorders inside the cells begins with the assembly of these mutant proteins in the form of insoluble inclusion bodies (IBs), which progressively sequester several vital cellular transcription factors and other essential proteins, and finally leads to neuronal dysfunction and apoptosis. We have shown earlier that targeted upregulation of Drosophila myc (dmyc) dominantly suppresses the poly(Q) toxicity in Drosophila. The present study examines the ability of the human c-myc proto-oncogene and also identifies the specific c-Myc isoform which drives the mitigation of poly(Q)-mediated neurotoxicity, so that it could be further substantiated as a potential drug target. We report for the first time that similar to dmyc, tissue-specific induced expression of human c-myc also suppresses poly(Q)-mediated neurotoxicity by an analogous mechanism. Among the three isoforms of c-Myc, the rescue potential was maximally manifested by the full-length c-Myc2 protein, followed by c-Myc1, but not by c-MycS which lacks the transactivation domain. Our study suggests that strategies focussing on the transactivation domain of c-Myc could be a very useful approach to design novel drug molecules against poly(Q) disorders.
Collapse
|
36
|
Pathogenic Huntington Alters BMP Signaling and Synaptic Growth through Local Disruptions of Endosomal Compartments. J Neurosci 2017; 37:3425-3439. [PMID: 28235896 DOI: 10.1523/jneurosci.2752-16.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 02/07/2017] [Accepted: 02/13/2017] [Indexed: 01/05/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by expansion of a polyglutamine (polyQ) stretch within the Huntingtin (Htt) protein. Pathogenic Htt disrupts multiple neuronal processes, including gene expression, axonal trafficking, proteasome and mitochondrial activity, and intracellular vesicle trafficking. However, the primary pathogenic mechanism and subcellular site of action for mutant Htt are still unclear. Using a Drosophila HD model, we found that pathogenic Htt expression leads to a profound overgrowth of synaptic connections that correlates directly with the levels of Htt at nerve terminals. Branches of the same nerve containing different levels of Htt show distinct phenotypes, indicating that Htt acts locally to disrupt synaptic growth. The effects of pathogenic Htt on synaptic growth arise from defective synaptic endosomal trafficking, leading to expansion of a recycling endosomal signaling compartment containing Sorting Nexin 16 and a reduction in late endosomes containing Rab11. The disruption of endosomal compartments leads to elevated BMP signaling within nerve terminals, driving excessive synaptic growth. Blocking aberrant signaling from endosomes or reducing BMP activity ameliorates the severity of HD pathology and improves viability. Pathogenic Htt is present largely in a nonaggregated form at synapses, indicating that cytosolic forms of the protein are likely to be the toxic species that disrupt endosomal signaling. Our data indicate that pathogenic Htt acts locally at nerve terminals to alter trafficking between endosomal compartments, leading to defects in synaptic structure that correlate with pathogenesis and lethality in the Drosophila HD model.SIGNIFICANCE STATEMENT Huntington's disease (HD) is the most commonly inherited polyglutamine expansion disorder, but how mutant Huntingtin (Htt) disrupts neuronal function is unclear. In particular, it is unknown within what subcellular compartment pathogenic Htt acts and whether the pathogenesis is associated with aggregated or more soluble forms of the protein. Using a Drosophila HD model, we find that nonaggregated pathogenic Htt acts locally at synaptic terminals to disrupt endosomal compartments, leading to aberrant wiring defects. Genetic manipulations to increase endosomal trafficking of synaptic growth receptors from signaling endosomes or to reduce BMP signaling reduce pathology in this HD model. These data indicate that pathogenic Htt can act locally within nerve terminals to disrupt synaptic endosomal signaling and induce neuropathology.
Collapse
|
37
|
Krench M, Littleton J. Neurotoxicity Pathways in Drosophila Models of the Polyglutamine Disorders. Curr Top Dev Biol 2017; 121:201-223. [DOI: 10.1016/bs.ctdb.2016.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
38
|
Babcock DT, Ganetzky B. Non-cell autonomous cell death caused by transmission of Huntingtin aggregates in Drosophila. Fly (Austin) 2016; 9:107-9. [PMID: 26655374 DOI: 10.1080/19336934.2015.1118591] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Recent evidence indicates that protein aggregates can spread between neurons in several neurodegenerative diseases but much remains unknown regarding the underlying mechanisms responsible for this spreading and its role in disease progression. We recently demonstrated that mutant Huntingtin aggregates spread between cells within the Drosophila brain resulting in non-cell autonomous loss of a pair of large neurons in the posterior protocerebrum. However, the full extent of neuronal loss throughout the brain was not determined. Here we examine the effects of driving expression of mutant Huntingtin in Olfactory Receptor Neurons (ORNs) by using a marker for cleaved caspase activity to monitor neuronal apoptosis as a function of age. We find widespread caspase activity in various brain regions over time, demonstrating that non-cell autonomous damage is widespread. Improved understanding of which neurons are most vulnerable and why should be useful in developing treatment strategies for neurodegenerative diseases that involve transcellular spreading of aggregates.
Collapse
Affiliation(s)
- Daniel T Babcock
- a Laboratory of Genetics, University of Wisconsin , Madison , WI , USA
| | - Barry Ganetzky
- a Laboratory of Genetics, University of Wisconsin , Madison , WI , USA
| |
Collapse
|
39
|
Serpionov GV, Alexandrov AI, Ter-Avanesyan MD. Distinct mechanisms of mutant huntingtin toxicity in different yeast strains. FEMS Yeast Res 2016; 17:fow102. [PMID: 27915242 DOI: 10.1093/femsyr/fow102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/17/2016] [Accepted: 12/01/2016] [Indexed: 11/12/2022] Open
Abstract
Expansion of polyglutamine stretches in several proteins causes neurodegenerative amyloidoses, including Huntington disease. In yeast, mutant huntingtin (mHtt) with a stretch of 103 glutamine residues (HttQ103) forms toxic aggregates. A range of yeast strains have been used to elucidate the mechanisms of mHtt toxicity, and have revealed perturbations of various unrelated processes. HttQ103 aggregates can induce aggregation of cellular proteins, many of which contain glutamine/asparagine-rich regions, including Sup35 and Def1. In the strain 74-D694 HttQ103, toxicity is related to aggregation-mediated depletion of soluble Sup35 and its interacting partner Sup45. Def1 was also implicated in mHtt toxicity, since its lack detoxified HttQ103 in another yeast strain, BY4741. Here we show that in BY4742, deletion of DEF1 lowers HttQ103 toxicity and decreases the amount of its polymers, but does not affect copolymerization of Sup35. Furthermore, in contrast to 74-D694, increasing the levels of soluble Sup35 and Sup45 does not alleviate toxicity of HttQ103 in BY4742. These data demonstrate a difference in the mechanisms underlying mHtt toxicity in different yeast strains and suggest that in humans with Huntington disease, neurons of different brain compartments and cells in other tissues can also be damaged by different mechanisms.
Collapse
Affiliation(s)
- Genrikh V Serpionov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| | - Alexander I Alexandrov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| | - Michael D Ter-Avanesyan
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow 119071, Russia
| |
Collapse
|
40
|
Abstract
Polyglutamine (polyQ) expansion within Huntingtin (Htt) causes the fatal neurodegenerative disorder Huntington’s Disease (HD). Although Htt is ubiquitously expressed and conserved from Drosophila to humans, its normal biological function is still being elucidated. Here we characterize a role for the Drosophila Htt homolog (dHtt) in fast axonal transport (FAT). Generation and expression of transgenic dHtt-mRFP and human Htt-mRFP fusion proteins in Drosophila revealed co-localization with mitochondria and synaptic vesicles undergoing FAT. However, Htt was not ubiquitously associated with the transport machinery, as it was excluded from dense-core vesicles and APLIP1 containing vesicles. Quantification of cargo movement in dHtt deficient axons revealed that mitochondria and synaptic vesicles show a decrease in the distance and duration of transport, and an increase in the number of pauses. In addition, the ratio of retrograde to anterograde flux was increased in mutant animals. Densecore vesicles did not display similar defects in processivity, but did show altered retrograde to anterograde flux along axons. Given the co-localization with mitochondria and synaptic vesicles, but not dense-core vesicles, the data suggest dHtt likely acts locally at cargo interaction sites to regulate processivity. An increase in dynein heavy chain expression was also observed in dHtt mutants, suggesting that the altered flux observed for all cargo may represent secondary transport changes occurring independent of dHtt’s primary function. Expression of dHtt in a milton (HAP1) mutant background revealed that the protein does not require mitochondria or HAP1 to localize along axons, suggesting Htt has an independent mechanism for coupling with motors to regulate their processivity during axonal transport.
Collapse
Affiliation(s)
- Kurt R Weiss
- a Department of Biology , The Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge , MA , USA.,b Department of Brain and Cognitive Sciences , The Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge , MA , USA
| | - J Troy Littleton
- a Department of Biology , The Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge , MA , USA.,b Department of Brain and Cognitive Sciences , The Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge , MA , USA
| |
Collapse
|
41
|
Krench M, Cho RW, Littleton JT. A Drosophila model of Huntington disease-like 2 exhibits nuclear toxicity and distinct pathogenic mechanisms from Huntington disease. Hum Mol Genet 2016; 25:3164-3177. [PMID: 27288455 DOI: 10.1093/hmg/ddw166] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/22/2016] [Accepted: 05/20/2016] [Indexed: 12/23/2022] Open
Abstract
Huntington disease-like 2 (HDL2) and Huntington disease (HD) are adult-onset neurodegenerative diseases characterized by movement disorders, psychiatric disturbances and cognitive decline. Brain tissue from HD and HDL2 patients shows degeneration of the striatum and ubiquitinated inclusions immunoreactive for polyglutamine (polyQ) antibodies. Despite these similarities, the diseases result from different genetic mutations. HD is caused by a CAG repeat expansion in the huntingtin (HTT) gene, while HDL2 results from an expansion at the junctophilin 3 (JPH3) locus. Recent evidence indicates that the HDL2 expansion may give rise to a toxic polyQ protein translated from an antisense mRNA derived from the JPH3 locus. To investigate this hypothesis, we generated and characterized a Drosophila HDL2 model and compared it with a previously established HD model. We find that neuronal expression of HDL2-Q15 is not toxic, while the expression of an expanded HDL2-Q138 protein is lethal. HDL2-Q138 forms large nuclear aggregates, with only smaller puncta observed in the cytoplasm. This is in contrast to what is observed in a Drosophila model of HD, where polyQ aggregates localize exclusively to the cytoplasm. Altering localization of HLD2 with the addition of a nuclear localization or nuclear export sequence demonstrates that nuclear accumulation is required for toxicity in the Drosophila HDL2 model. Directing HDL2-Q138 to the nucleus exacerbates toxicity in multiple tissue types, while confining HDL2-Q138 to the cytoplasm restores viability to control levels. We conclude that while HD and HDL2 have similar clinical profiles, distinct pathogenic mechanisms are likely to drive toxicity in Drosophila models of these disorders.
Collapse
Affiliation(s)
- Megan Krench
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences
| | - Richard W Cho
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences .,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
42
|
Patel KA, Sethi R, Dhara AR, Roy I. Challenges with osmolytes as inhibitors of protein aggregation: Can nucleic acid aptamers provide an answer? Int J Biol Macromol 2016; 100:75-88. [PMID: 27156694 DOI: 10.1016/j.ijbiomac.2016.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 02/07/2023]
Abstract
Protein aggregation follows some common motifs. Whether in the formation of inclusion bodies in heterologous overexpression systems or inclusions in protein conformational diseases, or aggregation during storage or transport of protein formulations, aggregates form cross beta-sheet structures and stain with amyloidophilic dyes like Thioflavin T and Congo Red, irrespective of the concerned protein. Traditionally, osmolytes are used to stabilize proteins against stress conditions. They are employed right from protein expression, through production and purification, to formulation and administration. As osmolytes interact with the solvent, the differential effect of the stress condition on the solvent mostly determines the effect of the osmolyte on protein stability. Nucleic acid aptamers, on the other hand, are highly specific for their targets. When selected against monomeric, natively folded proteins, they bind to them with very high affinity. This binding inhibits the unfolding of the protein and/or monomer-monomer interaction which are the initial common steps of protein aggregation. Thus, by changing the approach to a protein-centric model, aptamers are able to function as universal stabilizers of proteins. The review discusses cases where osmolytes were unable to provide stabilization to proteins against different stress conditions, a gap which the aptamers seem to be able to fill.
Collapse
Affiliation(s)
- Kinjal A Patel
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
| | - Ratnika Sethi
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
| | - Anita R Dhara
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
| | - Ipsita Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India.
| |
Collapse
|
43
|
Dinculescu A, Min SH, Dyka FM, Deng WT, Stupay RM, Chiodo V, Smith WC, Hauswirth WW. Pathological Effects of Mutant C1QTNF5 (S163R) Expression in Murine Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2016; 56:6971-80. [PMID: 26513502 DOI: 10.1167/iovs.15-17166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The mutation S163R in complement C1q tumor necrosis factor-related protein-5 (C1QTNF5) causes an autosomal dominant disorder known as late-onset retinal degeneration (L-ORD). In this study, our goal is to evaluate the consequences of mutant S163R C1QTNF5 expression in mouse RPE following its delivery using an adeno-associated viral (AAV) vector. METHODS We generated AAV vectors containing either human wild-type C1QTNF5 or mutant S163R C1QTNF5 driven by an RPE-specific BEST1 promoter, and delivered them subretinally into one eye of adult C57BL/6 mice. Transgene expression was detected by immunohistochemistry. Retinal function was assessed by full-field ERG. Pathological changes were further examined by digital fundus imaging and spectral-domain optical coherence tomography (SD-OCT). RESULTS We show that the AAV-expressed mutant S163R leads to pathological effects similar to some of those found in patients with advanced L-ORD, including RPE thinning, RPE cell loss, and retinal degeneration. In addition, we provide in vivo evidence that mutant S163R C1QTNF5 can form large, transparent, spherical intracellular aggregates throughout the RPE, which are detectable by light microscopy. In contrast to AAV-expressed wild-type C1QTNF5, which is secreted apically from the RPE toward the photoreceptor cells and the outer limiting membrane, the S163R mutant is primarily routed toward the basal side of RPE, where it forms thick, extracellular deposits over time. CONCLUSIONS Adeno-associated viral-targeted expression of mutant S163R in the RPE represents a useful approach for quickly generating animal models that mimic pathological features of L-ORD and offers the potential to understand disease mechanisms and develop therapeutic strategies.
Collapse
|
44
|
Kokona B, May CA, Cunningham NR, Richmond L, Jay Garcia F, Durante JC, Ulrich KM, Roberts CM, Link CD, Stafford WF, Laue TM, Fairman R. Studying polyglutamine aggregation in Caenorhabditis elegans using an analytical ultracentrifuge equipped with fluorescence detection. Protein Sci 2015; 25:605-17. [PMID: 26647351 DOI: 10.1002/pro.2854] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/01/2015] [Indexed: 11/11/2022]
Abstract
This work explores the heterogeneity of aggregation of polyglutamine fusion constructs in crude extracts of transgenic Caenorhabditis elegans animals. The work takes advantage of the recent technical advances in fluorescence detection for the analytical ultracentrifuge. Further, new sedimentation velocity methods, such as the multi-speed method for data capture and wide distribution analysis for data analysis, are applied to improve the resolution of the measures of heterogeneity over a wide range of sizes. The focus here is to test the ability to measure sedimentation of polyglutamine aggregates in complex mixtures as a prelude to future studies that will explore the effects of genetic manipulation and environment on aggregation and toxicity. Using sedimentation velocity methods, we can detect a wide range of aggregates, ranging from robust analysis of the monomer species through an intermediate and quite heterogeneous population of oligomeric species, and all the way up to detecting species that likely represent intact inclusion bodies based on comparison to an analysis of fluorescent puncta in living worms by confocal microscopy. Our results support the hypothesis that misfolding of expanded polyglutamine tracts into insoluble aggregates involves transitions through a number of stable intermediate structures, a model that accounts for how an aggregation pathway can lead to intermediates that can have varying toxic or protective attributes. An understanding of the details of intermediate and large-scale aggregation for polyglutamine sequences, as found in neurodegenerative diseases such as Huntington's Disease, will help to more precisely identify which aggregated species may be involved in toxicity and disease.
Collapse
Affiliation(s)
- Bashkim Kokona
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| | - Carrie A May
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, 03824
| | | | - Lynn Richmond
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| | - F Jay Garcia
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| | - Julia C Durante
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| | - Kathleen M Ulrich
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| | - Christine M Roberts
- Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, 80309
| | - Christopher D Link
- Integrative Physiology, University of Colorado Boulder, Boulder, Colorado, 80309
| | - Walter F Stafford
- Boston Biomedical Research Institute, Watertown, Massachusetts, 02472
| | - Thomas M Laue
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, 03824
| | - Robert Fairman
- Department of Biology, Haverford College, Haverford, Pennsylvania, 19041
| |
Collapse
|
45
|
Serpionov GV, Alexandrov AI, Antonenko YN, Ter-Avanesyan MD. A protein polymerization cascade mediates toxicity of non-pathological human huntingtin in yeast. Sci Rep 2015; 5:18407. [PMID: 26673834 PMCID: PMC4682096 DOI: 10.1038/srep18407] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022] Open
Abstract
Several neurodegenerative amyloidoses, including Huntington disease, are caused by expansion of polyglutamine (polyQ) stretches in otherwise unrelated proteins. In a yeast model, an N-terminal fragment of mutant huntingtin with a stretch of 103 glutamine residues aggregates and causes toxicity, while its non-toxic wild type variant with a sequence of 25 glutamines (Htt25Q) does not aggregate. Here, we observed that non-toxic polymers of various proteins with glutamine-rich domains could seed polymerization of Htt25Q, which caused toxicity by seeding polymerization of the glutamine/asparagine-rich Sup35 protein thus depleting the soluble pools of this protein and its interacting partner, Sup45. Importantly, only polymers of Htt25Q, but not of the initial benign polymers, induced Sup35 polymerization, indicating an intermediary role of Htt25Q in cross-seeding Sup35 polymerization. These data provide a novel insight into interactions between amyloidogenic proteins and suggest a possible role for these interactions in the pathogenesis of Huntington and other polyQ diseases.
Collapse
Affiliation(s)
- Genrikh V Serpionov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences. 33, bld. 2 Leninsky Ave., Moscow 119071, Russia
| | - Alexander I Alexandrov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences. 33, bld. 2 Leninsky Ave., Moscow 119071, Russia
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie gori, 1, bldg. 40, Moscow 119991, Russia
| | - Michael D Ter-Avanesyan
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences. 33, bld. 2 Leninsky Ave., Moscow 119071, Russia
| |
Collapse
|
46
|
Transcellular spreading of huntingtin aggregates in the Drosophila brain. Proc Natl Acad Sci U S A 2015; 112:E5427-33. [PMID: 26351672 DOI: 10.1073/pnas.1516217112] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A key feature of many neurodegenerative diseases is the accumulation and subsequent aggregation of misfolded proteins. Recent studies have highlighted the transcellular propagation of protein aggregates in several major neurodegenerative diseases, although the precise mechanisms underlying this spreading and how it relates to disease pathology remain unclear. Here we use a polyglutamine-expanded form of human huntingtin (Htt) with a fluorescent tag to monitor the spreading of aggregates in the Drosophila brain in a model of Huntington's disease. Upon expression of this construct in a defined subset of neurons, we demonstrate that protein aggregates accumulate at synaptic terminals and progressively spread throughout the brain. These aggregates are internalized and accumulate within other neurons. We show that Htt aggregates cause non-cell-autonomous pathology, including loss of vulnerable neurons that can be prevented by inhibiting endocytosis in these neurons. Finally we show that the release of aggregates requires N-ethylmalemide-sensitive fusion protein 1, demonstrating that active release and uptake of Htt aggregates are important elements of spreading and disease progression.
Collapse
|
47
|
Xu Z, Tito AJ, Rui YN, Zhang S. Studying polyglutamine diseases in Drosophila. Exp Neurol 2015; 274:25-41. [PMID: 26257024 DOI: 10.1016/j.expneurol.2015.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 12/16/2022]
Abstract
Polyglutamine (polyQ) diseases are a family of dominantly transmitted neurodegenerative disorders caused by an abnormal expansion of CAG trinucleotide repeats in the protein-coding regions of the respective disease-causing genes. Despite their simple genetic basis, the etiology of these diseases is far from clear. Over the past two decades, Drosophila has proven to be successful in modeling this family of neurodegenerative disorders, including the faithful recapitulation of pathological features such as polyQ length-dependent formation of protein aggregates and progressive neuronal degeneration. Additionally, it has been valuable in probing the pathogenic mechanisms, in identifying and evaluating disease modifiers, and in helping elucidate the normal functions of disease-causing genes. Knowledge learned from this simple invertebrate organism has had a large impact on our understanding of these devastating brain diseases.
Collapse
Affiliation(s)
- Zhen Xu
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Antonio Joel Tito
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; Programs in Human and Molecular Genetics and Neuroscience, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Graduate School of Biomedical Sciences, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Yan-Ning Rui
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Sheng Zhang
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; Department of Neurobiology and Anatomy, 1825 Pressler Street, Houston, TX 77030, United States; Programs in Human and Molecular Genetics and Neuroscience, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Graduate School of Biomedical Sciences, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States.
| |
Collapse
|
48
|
Lewis EA, Smith GA. Using Drosophila models of Huntington's disease as a translatable tool. J Neurosci Methods 2015; 265:89-98. [PMID: 26241927 DOI: 10.1016/j.jneumeth.2015.07.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 11/17/2022]
Abstract
The Huntingtin (Htt) protein is essential for a wealth of intracellular signaling cascades and when mutated, causes multifactorial dysregulation of basic cellular processes. Understanding the contribution to each of these intracellular pathways is essential for the elucidation of mechanisms that drive pathophysiology. Using appropriate models of Huntington's disease (HD) is key to finding the molecular mechanisms that contribute to neurodegeneration. While mouse models and cell lines expressing mutant Htt have been instrumental to HD research, there has been a significant contribution to our understating of the disease from studies utilizing Drosophila melanogaster. Flies have an Htt protein, so the endogenous pathways with which it interacts are likely conserved. Transgenic flies engineered to overexpress the human mutant HTT gene display protein aggregation, neurodegeneration, behavioral deficits and a reduced lifespan. The short life span of flies, low cost of maintaining stocks and genetic tools available for in vivo manipulation make them ideal for the discovery of new genes that are involved in HD pathology. It is possible to do rapid genome wide screens for enhancers or suppressors of the mutant Htt-mediated phenotype, expressed in specific tissues or neuronal subtypes. However, there likely remain many yet unknown genes that modify disease progression, which could be found through additional screening approaches using the fly. Importantly, there have been instances where genes discovered in Drosophila have been translated to HD mouse models.
Collapse
Affiliation(s)
- Elizabeth A Lewis
- Neurobiology Department, Aaron Lazare Research Building, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Gaynor A Smith
- Neurobiology Department, Aaron Lazare Research Building, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| |
Collapse
|
49
|
De Genst E, Chirgadze DY, Klein FAC, Butler DC, Matak-Vinković D, Trottier Y, Huston JS, Messer A, Dobson CM. Structure of a single-chain Fv bound to the 17 N-terminal residues of huntingtin provides insights into pathogenic amyloid formation and suppression. J Mol Biol 2015; 427:2166-78. [PMID: 25861763 PMCID: PMC4451460 DOI: 10.1016/j.jmb.2015.03.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/17/2015] [Accepted: 03/30/2015] [Indexed: 10/25/2022]
Abstract
Huntington's disease is triggered by misfolding of fragments of mutant forms of the huntingtin protein (mHTT) with aberrant polyglutamine expansions. The C4 single-chain Fv antibody (scFv) binds to the first 17 residues of huntingtin [HTT(1-17)] and generates substantial protection against multiple phenotypic pathologies in situ and in vivo. We show in this paper that C4 scFv inhibits amyloid formation by exon1 fragments of huntingtin in vitro and elucidate the structural basis for this inhibition and protection by determining the crystal structure of the complex of C4 scFv and HTT(1-17). The peptide binds with residues 3-11 forming an amphipathic helix that makes contact with the antibody fragment in such a way that the hydrophobic face of this helix is shielded from the solvent. Residues 12-17 of the peptide are in an extended conformation and interact with the same region of another C4 scFv:HTT(1-17) complex in the asymmetric unit, resulting in a β-sheet interface within a dimeric C4 scFv:HTT(1-17) complex. The nature of this scFv-peptide complex was further explored in solution by high-resolution NMR and physicochemical analysis of species in solution. The results provide insights into the manner in which C4 scFv inhibits the aggregation of HTT, and hence into its therapeutic potential, and suggests a structural basis for the initial interactions that underlie the formation of disease-associated amyloid fibrils by HTT.
Collapse
Affiliation(s)
- Erwin De Genst
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Dimitri Y Chirgadze
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Fabrice A C Klein
- Translational Medicine and Neurogenetics Programme, Institute of Genetics and Molecular and Cellular Biology, 67404 Illkirch Cédex, France
| | - David C Butler
- Neural Stem Cell Institute, Regenerative Research Foundation, Rensselaer, NY 12144, USA; Department of Biomedical Sciences, University at Albany, Albany, NY 12208, USA
| | - Dijana Matak-Vinković
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Yvon Trottier
- Translational Medicine and Neurogenetics Programme, Institute of Genetics and Molecular and Cellular Biology, 67404 Illkirch Cédex, France
| | - James S Huston
- James S. Huston, The Antibody Society, Newton, MA 02462, USA
| | - Anne Messer
- Neural Stem Cell Institute, Regenerative Research Foundation, Rensselaer, NY 12144, USA; Department of Biomedical Sciences, University at Albany, Albany, NY 12208, USA
| | - Christopher M Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| |
Collapse
|
50
|
Barbaro BA, Lukacsovich T, Agrawal N, Burke J, Bornemann DJ, Purcell JM, Worthge SA, Caricasole A, Weiss A, Song W, Morozova OA, Colby DW, Marsh JL. Comparative study of naturally occurring huntingtin fragments in Drosophila points to exon 1 as the most pathogenic species in Huntington's disease. Hum Mol Genet 2014; 24:913-25. [PMID: 25305076 DOI: 10.1093/hmg/ddu504] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Although Huntington's disease is caused by the expansion of a CAG triplet repeat within the context of the 3144-amino acid huntingtin protein (HTT), studies reveal that N-terminal fragments of HTT containing the expanded PolyQ region can be produced by proteolytic processing and/or aberrant splicing. N-terminal HTT fragments are also prevalent in postmortem tissue, and expression of some of these fragments in model organisms can cause pathology. This has led to the hypothesis that N-terminal peptides may be critical modulators of disease pathology, raising the possibility that targeting aberrant splicing or proteolytic processing may present attractive therapeutic targets. However, many factors can contribute to pathology, including genetic background and differential expression of transgenes, in addition to intrinsic differences between fragments and their cellular effects. We have used Drosophila as a model system to determine the relative toxicities of different naturally occurring huntingtin fragments in a system in which genetic background, transgene expression levels and post-translational proteolytic processing can be controlled. These studies reveal that among the naturally occurring N-terminal HTT peptides, the exon 1 peptide is exceptionally pathogenic and exhibits unique structural and biophysical behaviors that do not appear to be incremental changes compared with other fragments. If this proves correct, efforts to specifically reduce the levels of exon 1 peptides or to target toxicity-influencing post-translational modifications that occur with the exon 1 context are likely to have the greatest impact on pathology.
Collapse
Affiliation(s)
- Brett A Barbaro
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Tamas Lukacsovich
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Namita Agrawal
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA, Department of Zoology, University of Delhi, Delhi 110007, India
| | - John Burke
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Doug J Bornemann
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Judith M Purcell
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Shane A Worthge
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | | | | | - Wan Song
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA
| | - Olga A Morozova
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA
| | - David W Colby
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California, Irvine 92697, USA,
| |
Collapse
|