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Wu Y, Chen Y, Yu X, Zhang M, Li Z. Towards Understanding Neurodegenerative Diseases: Insights from Caenorhabditis elegans. Int J Mol Sci 2023; 25:443. [PMID: 38203614 PMCID: PMC10778690 DOI: 10.3390/ijms25010443] [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: 12/08/2023] [Revised: 12/23/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
The elevated occurrence of debilitating neurodegenerative disorders, such as amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), Alzheimer's disease (AD), Parkinson's disease (PD) and Machado-Joseph disease (MJD), demands urgent disease-modifying therapeutics. Owing to the evolutionarily conserved molecular signalling pathways with mammalian species and facile genetic manipulation, the nematode Caenorhabditis elegans (C. elegans) emerges as a powerful and manipulative model system for mechanistic insights into neurodegenerative diseases. Herein, we review several representative C. elegans models established for five common neurodegenerative diseases, which closely simulate disease phenotypes specifically in the gain-of-function aspect. We exemplify applications of high-throughput genetic and drug screenings to illustrate the potential of C. elegans to probe novel therapeutic targets. This review highlights the utility of C. elegans as a comprehensive and versatile platform for the dissection of neurodegenerative diseases at the molecular level.
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Affiliation(s)
| | | | | | | | - Zhaoyu Li
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; (Y.W.); (Y.C.); (X.Y.); (M.Z.)
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2
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Pradhan SS, R SS, Kanikaram SP, V M DD, Pargaonkar A, Dandamudi RB, Sivaramakrishnan V. Metabolic deregulation associated with aging modulates protein aggregation in the yeast model of Huntington's disease. J Biomol Struct Dyn 2023:1-18. [PMID: 37732342 DOI: 10.1080/07391102.2023.2257322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 09/05/2023] [Indexed: 09/22/2023]
Abstract
Huntington's disease is associated with increased CAG repeat resulting in an expanded polyglutamine tract in the protein Huntingtin (HTT) leading to its aggregation resulting in neurodegeneration. Previous studies have shown that N-terminal HTT with 46Q aggregated in the stationary phase but not the logarithmic phase in the yeast model of HD. We carried out a metabolomic analysis of logarithmic and stationary phase yeast model of HD expressing different polyQ lengths attached to N-terminal HTT tagged with enhanced green fluorescent protein (EGFP). The results show significant changes in the metabolic profile and deregulated pathways in stationary phase cells compared to logarithmic phase cells. Comparison of metabolic pathways obtained from logarithmic phase 46Q versus 25Q with those obtained for presymptomatic HD patients from our previous study and drosophila model of HD showed considerable overlap. The arginine biosynthesis pathway emerged as one of the key pathways that is common in stationary phase yeast compared to logarithmic phase and HD patients. Treatment of yeast with arginine led to a significant decrease, while transfer to arginine drop-out media led to a significant increase in the size of protein aggregates in both logarithmic and stationary phase yeast model of HD. Knockout of arginine transporters in the endoplasmic reticulum and vacuole led to a significant decrease in mutant HTT aggregation. Overall our results highlight arginine as a critical metabolite that modulates the aggregation of mutant HTT and disease progression in HD.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sai Sanwid Pradhan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh, India
| | - Sai Swaroop R
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh, India
| | - Sai Phalguna Kanikaram
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh, India
| | - Datta Darshan V M
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh, India
| | - Ashish Pargaonkar
- Application Division, Agilent Technologies Ltd., Bengaluru, Karnataka, India
| | | | - Venketesh Sivaramakrishnan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Anantapur, Andhra Pradesh, India
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3
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Jain M, Patil N, Abdi G, Abbasi Tarighat M, Mohammed A, Ahmad Mohd Zain MR, Goh KW. Mechanistic Insights and Potential Therapeutic Approaches in PolyQ Diseases via Autophagy. Biomedicines 2023; 11:biomedicines11010162. [PMID: 36672670 PMCID: PMC9856063 DOI: 10.3390/biomedicines11010162] [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: 08/21/2022] [Revised: 10/23/2022] [Accepted: 10/25/2022] [Indexed: 01/11/2023] Open
Abstract
Polyglutamine diseases are a group of congenital neurodegenerative diseases categorized with genomic abnormalities in the expansion of CAG triplet repeats in coding regions of specific disease-related genes. Protein aggregates are the toxic hallmark for polyQ diseases and initiate neuronal death. Autophagy is a catabolic process that aids in the removal of damaged organelles or toxic protein aggregates, a process required to maintain cellular homeostasis that has the potential to fight against neurodegenerative diseases, but this pathway gets affected under diseased conditions, as there is a direct impact on autophagy-related gene expression. The increase in the accumulation of autophagy vesicles reported in neurodegenerative diseases was due to an increase in autophagy or may have been due to a decrease in autophagy flux. These reports suggested that there is a contribution of autophagy in the pathology of diseases and regulation in the process of autophagy. It was demonstrated in various disease models of polyQ diseases that autophagy upregulation by using modulators can enhance the dissolution of toxic aggregates and delay disease progression. In this review, interaction of the autophagy pathway with polyQ diseases was analyzed, and a therapeutic approach with autophagy inducing drugs was established for disease pathogenesis.
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Affiliation(s)
- Mukul Jain
- Department of Lifesciences, Parul Institute of Applied Sciences, Parul University, Vadodara 391760, India
- Lab 209 Cell and Developmental Biology Lab, Centre of Research for Development, Parul University, Vadodara 391760, India
| | - Nil Patil
- Department of Lifesciences, Parul Institute of Applied Sciences, Parul University, Vadodara 391760, India
- Lab 209 Cell and Developmental Biology Lab, Centre of Research for Development, Parul University, Vadodara 391760, India
| | - Gholamreza Abdi
- Department of Biotechnology, Persian Gulf Research Institute, Persian Gulf University, Bushehr, 75169, Iran
- Correspondence: (G.A.); (M.R.A.M.Z.); (K.W.G.)
| | - Maryam Abbasi Tarighat
- Faculty of Nano and Bio Science and Technology, Persian Gulf University, Bushehr 75169, Iran
| | - Arifullah Mohammed
- Department of Agriculture, Faculty of Agro-Based Industry, Universiti Malaysia Kelantan, Jeli 17600, Malaysia
| | - Muhammad Rajaei Ahmad Mohd Zain
- Department of Orthopaedics, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia
- Correspondence: (G.A.); (M.R.A.M.Z.); (K.W.G.)
| | - Khang Wen Goh
- Faculty of Data Science and Information Technology, INTI International University, Nilai 71800, Malaysia
- Correspondence: (G.A.); (M.R.A.M.Z.); (K.W.G.)
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4
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Lee Y, Kim H, Barker D, Vijayvargia R, Atwal RS, Specht H, Keshishian H, Carr SA, Lee R, Kwak S, Hyun KG, Loupe J, MacDonald ME, Song JJ, Seong IS. Huntingtin turnover: modulation of huntingtin degradation by cAMP-dependent protein kinase A (PKA) phosphorylation of C-HEAT domain Ser2550. Hum Mol Genet 2023; 32:30-45. [PMID: 35908190 DOI: 10.1093/hmg/ddac165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 01/25/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by an inherited unstable HTT CAG repeat that expands further, thereby eliciting a disease process that may be initiated by polyglutamine-expanded huntingtin or a short polyglutamine-product. Phosphorylation of selected candidate residues is reported to mediate polyglutamine-fragment degradation and toxicity. Here to support the discovery of phosphosites involved in the life-cycle of (full-length) huntingtin, we employed mass spectrometry-based phosphoproteomics to systematically identify sites in purified huntingtin and in the endogenous protein by proteomic and phosphoproteomic analyses of members of an HD neuronal progenitor cell panel. Our results bring total huntingtin phosphosites to 95, with more located in the N-HEAT domain relative to numbers in the Bridge and C-HEAT domains. Moreover, phosphorylation of C-HEAT Ser2550 by cAMP-dependent protein kinase (PKA), the top hit in kinase activity screens, was found to hasten huntingtin degradation, such that levels of the catalytic subunit (PRKACA) were inversely related to huntingtin levels. Taken together, these findings highlight categories of phosphosites that merit further study and provide a phosphosite kinase pair (pSer2550-PKA) with which to investigate the biological processes that regulate huntingtin degradation and thereby influence the steady state levels of huntingtin in HD cells.
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Affiliation(s)
- Yejin Lee
- Department of Biological Sciences, KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Hyeongju Kim
- Department of Biological Sciences, KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Douglas Barker
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Ravi Vijayvargia
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Ranjit Singh Atwal
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Harrison Specht
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Hasmik Keshishian
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Steven A Carr
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Ramee Lee
- CHDI Management/CHDI Foundation, Princeton, NJ 08540, USA
| | - Seung Kwak
- CHDI Management/CHDI Foundation, Princeton, NJ 08540, USA
| | - Kyung-Gi Hyun
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Jacob Loupe
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
| | - Ji-Joon Song
- Department of Biological Sciences, KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ihn Sik Seong
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02114, USA
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5
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The folding and misfolding mechanisms of multidomain proteins. MEDICINE IN DRUG DISCOVERY 2022. [DOI: 10.1016/j.medidd.2022.100126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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6
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Gkekas I, Gioran A, Boziki MK, Grigoriadis N, Chondrogianni N, Petrakis S. Oxidative Stress and Neurodegeneration: Interconnected Processes in PolyQ Diseases. Antioxidants (Basel) 2021; 10:antiox10091450. [PMID: 34573082 PMCID: PMC8471619 DOI: 10.3390/antiox10091450] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 12/16/2022] Open
Abstract
Neurodegenerative polyglutamine (polyQ) disorders are caused by trinucleotide repeat expansions within the coding region of disease-causing genes. PolyQ-expanded proteins undergo conformational changes leading to the formation of protein inclusions which are associated with selective neuronal degeneration. Several lines of evidence indicate that these mutant proteins are associated with oxidative stress, proteasome impairment and microglia activation. These events may correlate with the induction of inflammation in the nervous system and disease progression. Here, we review the effect of polyQ-induced oxidative stress in cellular and animal models of polyQ diseases. Furthermore, we discuss the interplay between oxidative stress, neurodegeneration and neuroinflammation using as an example the well-known neuroinflammatory disease, Multiple Sclerosis. Finally, we review some of the pharmaceutical interventions which may delay the onset and progression of polyQ disorders by targeting disease-associated mechanisms.
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Affiliation(s)
- Ioannis Gkekas
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece;
| | - Anna Gioran
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece; (A.G.); (N.C.)
| | - Marina Kleopatra Boziki
- 2nd Neurological Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (M.K.B.); (N.G.)
| | - Nikolaos Grigoriadis
- 2nd Neurological Department, AHEPA University General Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (M.K.B.); (N.G.)
| | - Niki Chondrogianni
- Institute of Chemical Biology, National Hellenic Research Foundation, 11635 Athens, Greece; (A.G.); (N.C.)
| | - Spyros Petrakis
- Institute of Applied Biosciences/Centre for Research and Technology Hellas, 57001 Thessaloniki, Greece;
- Correspondence: ; Tel.: +30-2311257525
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7
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Huntingtin and Its Role in Mechanisms of RNA-Mediated Toxicity. Toxins (Basel) 2021; 13:toxins13070487. [PMID: 34357961 PMCID: PMC8310054 DOI: 10.3390/toxins13070487] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/09/2021] [Accepted: 07/11/2021] [Indexed: 12/20/2022] Open
Abstract
Huntington’s disease (HD) is caused by a CAG-repeat expansion mutation in the Huntingtin (HTT) gene. It is characterized by progressive psychiatric and neurological symptoms in combination with a progressive movement disorder. Despite the ubiquitous expression of HTT, pathological changes occur quite selectively in the central nervous system. Since the discovery of HD more than 150 years ago, a lot of research on molecular mechanisms contributing to neurotoxicity has remained the focal point. While traditionally, the protein encoded by the HTT gene remained the cynosure for researchers and was extensively reviewed elsewhere, several studies in the last few years clearly indicated the contribution of the mutant RNA transcript to cellular dysfunction as well. In this review, we outline recent studies on RNA-mediated molecular mechanisms that are linked to cellular dysfunction in HD models. These mechanisms include mis-splicing, aberrant translation, deregulation of the miRNA machinery, deregulated RNA transport and abnormal regulation of mitochondrial RNA. Furthermore, we summarize recent therapeutical approaches targeting the mutant HTT transcript. While currently available treatments are of a palliative nature only and do not halt the disease progression, recent clinical studies provide hope that these novel RNA-targeting strategies will lead to better therapeutic approaches.
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8
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Dantuma NP, Herzog LK. Machado-Joseph Disease: A Stress Combating Deubiquitylating Enzyme Changing Sides. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1233:237-260. [PMID: 32274760 DOI: 10.1007/978-3-030-38266-7_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Machado-Joseph disease (MJD), also known as Spinocerebellar ataxia type 3 (SCA3), is an autosomal dominant inheritable neurodegenerative disorder. After a long pre-symptomatic period, this late-onset disease progressively disables patients and typically leads to premature death. Neuronal loss in specific regions of the cerebellum, brainstem and basal ganglia as well as the spinal cord explains the spectra of debilitating neurological symptoms, most strikingly progressive limb, and gait ataxia. The genetic cause of MJD is a polyglutamine (polyQ) repeat expansion in the gene that encodes ataxin-3. This polyQ-containing protein displays a well-defined catalytic activity as ataxin-3 is a deubiquitylating enzyme that removes and disassembles ubiquitin chains from specific substrates. While mutant ataxin-3 with an expanded polyQ repeat induces cellular stress due to its propensity to aggregate, the native functions of wild-type ataxin-3 are linked to the cellular countermeasures against the very same stress conditions inflicted by polyQ-containing and other aggregation-prone proteins. Hence, a mixture of gain-of-function and loss-of-function mechanisms are likely to contribute to the neuronal demise observed in MJD. In this review, we discuss the intimate link between ataxin-3 and cellular stress and its relevance for therapeutic intervention in MJD.
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Affiliation(s)
- Nico P Dantuma
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden.
| | - Laura K Herzog
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden
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9
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Poulson BG, Szczepski K, Lachowicz JI, Jaremko L, Emwas AH, Jaremko M. Aggregation of biologically important peptides and proteins: inhibition or acceleration depending on protein and metal ion concentrations. RSC Adv 2020; 10:215-227. [PMID: 35492549 PMCID: PMC9047971 DOI: 10.1039/c9ra09350h] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 12/14/2019] [Indexed: 01/03/2023] Open
Abstract
The process of aggregation of proteins and peptides is dependent on the concentration of proteins, and the rate of aggregation can be altered by the presence of metal ions, but this dependence is not always a straightforward relationship. In general, aggregation does not occur under normal physiological conditions, yet it can be induced in the presence of certain metal ions. However, the extent of the influence of metal ion interactions on protein aggregation has not yet been fully comprehended. A consensus has thus been difficult to reach because the acceleration/inhibition of the aggregation of proteins in the presence of metal ions depends on several factors such as pH and the concentration of the aggregated proteins involved as well as metal concentration level of metal ions. Metal ions, like Cu2+, Zn2+, Pb2+etc. may either accelerate or inhibit aggregation simply because the experimental conditions affect the behavior of biomolecules. It is clear that understanding the relationship between metal ion concentration and protein aggregation will prove useful for future scientific applications. This review focuses on the dependence of the aggregation of selected important biomolecules (peptides and proteins) on metal ion concentrations. We review proteins that are prone to aggregation, the result of which can cause serious neurodegenerative disorders. Furthering our understanding of the relationship between metal ion concentration and protein aggregation will prove useful for future scientific applications, such as finding therapies for neurodegenerative diseases. The process of aggregation of proteins and peptides is dependent on the concentration of proteins, and the rate of aggregation can be altered by the presence of metal ions, but this dependence is not always a straightforward relationship.![]()
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Affiliation(s)
- Benjamin Gabriel Poulson
- Division of Biological and Environmental Sciences and Engineering (BESE)
- King Abdullah University of Science and Technology (KAUST)
- Thuwal 23955-6900
- Saudi Arabia
| | - Kacper Szczepski
- Division of Biological and Environmental Sciences and Engineering (BESE)
- King Abdullah University of Science and Technology (KAUST)
- Thuwal 23955-6900
- Saudi Arabia
| | - Joanna Izabela Lachowicz
- Department of Medical Sciences and Public Health
- University of Cagliari
- Cittadella Universitaria
- Italy
| | - Lukasz Jaremko
- Division of Biological and Environmental Sciences and Engineering (BESE)
- King Abdullah University of Science and Technology (KAUST)
- Thuwal 23955-6900
- Saudi Arabia
| | - Abdul-Hamid Emwas
- Core Labs
- King Abdullah University of Science and Technology (KAUST)
- Thuwal 23955-6900
- Saudi Arabia
| | - Mariusz Jaremko
- Division of Biological and Environmental Sciences and Engineering (BESE)
- King Abdullah University of Science and Technology (KAUST)
- Thuwal 23955-6900
- Saudi Arabia
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10
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Singer E, Walter C, Fabbro D, Rageot D, Beaufils F, Wymann MP, Rischert N, Riess O, Hillmann P, Nguyen HP. Brain-penetrant PQR620 mTOR and PQR530 PI3K/mTOR inhibitor reduce huntingtin levels in cell models of HD. Neuropharmacology 2019; 162:107812. [PMID: 31622602 DOI: 10.1016/j.neuropharm.2019.107812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/25/2019] [Accepted: 10/10/2019] [Indexed: 12/20/2022]
Abstract
One of the pathological hallmarks of Huntington disease (HD) is accumulation of the disease-causing mutant huntingtin (mHTT), which leads to the disruption of a variety of cellular functions, ultimately resulting in cell death. Induction of autophagy, for example by the inhibition of mechanistic target of rapamycin (mTOR) signaling, has been shown to reduce HTT levels and aggregates. While rapalogs like rapamycin allosterically inhibit the mTOR complex 1 (TORC1), ATP-competitive mTOR inhibitors suppress activities of TORC1 and TORC2 and have been shown to be more efficient in inducing autophagy and reducing protein levels and aggregates than rapalogs. The ability to cross the blood-brain barrier of first generation catalytic mTOR inhibitors has so far been limited, and therefore sufficient target coverage in the brain could not be reached. Two novel, brain penetrant compounds - the mTORC1/2 inhibitor PQR620, and the dual pan-phosphoinositide 3-kinase (PI3K) and mTORC1/2 kinase inhibitor PQR530 - were evaluated by assessing their potential to induce autophagy and reducing mHTT levels. For this purpose, expression levels of autophagic markers and well-defined mTOR targets were analyzed in STHdh cells and HEK293T cells and in mouse brains. Both compounds potently inhibited mTOR signaling in cell models as well as in mouse brain. As proof of principle, reduction of aggregates and levels of soluble mHTT were demonstrated upon treatment with both compounds. Originally developed for cancer treatment, these second generation mTORC1/2 and PI3K/mTOR inhibitors show brain penetrance and efficacy in cell models of HD, making them candidate molecules for further investigations in HD.
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Affiliation(s)
- Elisabeth Singer
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany; Centre for Rare Diseases (ZSE), University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany.
| | - Carolin Walter
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany; Centre for Rare Diseases (ZSE), University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany.
| | - Doriano Fabbro
- PIQUR Therapeutics AG, Hochbergerstrasse 60C, Basel, 4057, Switzerland.
| | - Denise Rageot
- Department of Biomedicine, University of Basel, Mattenstrasse 28, Basel, 4056, Switzerland.
| | - Florent Beaufils
- PIQUR Therapeutics AG, Hochbergerstrasse 60C, Basel, 4057, Switzerland.
| | - Matthias P Wymann
- Department of Biomedicine, University of Basel, Mattenstrasse 28, Basel, 4056, Switzerland.
| | - Nadine Rischert
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany; Centre for Rare Diseases (ZSE), University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany.
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany; Centre for Rare Diseases (ZSE), University of Tuebingen, Calwerstrasse 7, Tuebingen, 72076, Germany.
| | - Petra Hillmann
- PIQUR Therapeutics AG, Hochbergerstrasse 60C, Basel, 4057, Switzerland.
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Universitaetsstrasse 150, Bochum, 44801, Germany.
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11
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Banez-Coronel M, Ranum LPW. Repeat-associated non-AUG (RAN) translation: insights from pathology. J Transl Med 2019; 99:929-942. [PMID: 30918326 PMCID: PMC7219275 DOI: 10.1038/s41374-019-0241-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
More than 40 different neurological diseases are caused by microsatellite repeat expansions. Since the discovery of repeat-associated non-AUG (RAN) translation by Zu et al. in 2011, nine expansion disorders have been identified as RAN-positive diseases. RAN proteins are translated from different types of nucleotide repeat expansions and can be produced from both sense and antisense transcripts. In some diseases, RAN proteins have been shown to accumulate in affected brain regions. Here we review the pathological and molecular aspects associated with RAN protein accumulation for each particular disorder, the correlation between disease pathology and the available in vivo models and the common aspects shared by some of the newly discovered RAN proteins.
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Affiliation(s)
- Monica Banez-Coronel
- Center for NeuroGenetics, University of Florida, Gainesville, FL, 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, 32610, USA
| | - Laura P W Ranum
- Center for NeuroGenetics, University of Florida, Gainesville, FL, 32610, USA.
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, 32610, USA.
- Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
- McKnight Brain Institute, University of Florida, Gainesville, FL, 32610, USA.
- Genetics Institute, University of Florida, Gainesville, FL, 32610, USA.
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12
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Chen ZS, Wong AKY, Cheng TC, Koon AC, Chan HYE. FipoQ/FBXO33, a Cullin-1-based ubiquitin ligase complex component modulates ubiquitination and solubility of polyglutamine disease protein. J Neurochem 2019; 149:781-798. [PMID: 30685895 DOI: 10.1111/jnc.14669] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/17/2018] [Accepted: 01/16/2019] [Indexed: 12/16/2022]
Abstract
Polyglutamine (polyQ) diseases describe a group of progressive neurodegenerative disorders caused by the CAG triplet repeat expansion in the coding region of the disease genes. To date, nine such diseases, including spinocerebellar ataxia type 3 (SCA3), have been reported. The formation of SDS-insoluble protein aggregates in neurons causes cellular dysfunctions, such as impairment of the ubiquitin-proteasome system, and contributes to polyQ pathologies. Recently, the E3 ubiquitin ligases, which govern substrate specificity of the ubiquitin-proteasome system, have been implicated in polyQ pathogenesis. The Cullin (Cul) proteins are major components of Cullin-RING ubiquitin ligases (CRLs) complexes that are evolutionarily conserved in the Drosophila genome. In this study, we examined the effect of individual Culs on SCA3 pathogenesis and found that the knockdown of Cul1 expression enhances SCA3-induced neurodegeneration and reduces the solubility of expanded SCA3-polyQ proteins. The F-box proteins are substrate receptors of Cul1-based CRL. We further performed a genetic modifier screen of the 19 Drosophila F-box genes and identified F-box involved in polyQ pathogenesis (FipoQ) as a genetic modifier of SCA3 degeneration that modulates the ubiquitination and solubility of expanded SCA3-polyQ proteins. In the human SK-N-MC cell model, we identified that F-box only protein 33 (FBXO33) exerts similar functions as FipoQ in modulating the ubiquitination and solubility of expanded SCA3-polyQ proteins. Taken together, our study demonstrates that Cul1-based CRL and its associated F-box protein, FipoQ/FBXO33, modify SCA3 protein toxicity. These findings will lead to a better understanding of the disease mechanism of SCA3 and provide insights for developing treatments against SCA3. Cover Image for this issue: doi: 10.1111/jnc.14510.
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Affiliation(s)
- Zhefan Stephen Chen
- Laboratory of Drosophila Research, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Azaria Kam Yan Wong
- Laboratory of Drosophila Research, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Molecular Biotechnology Programme, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Tat Cheung Cheng
- Laboratory of Drosophila Research, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Alex Chun Koon
- Laboratory of Drosophila Research, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Ho Yin Edwin Chan
- Laboratory of Drosophila Research, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Molecular Biotechnology Programme, Faculty of Science, School of Life Sciences, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.,Gerald Choa Neuroscience Centre, The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
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13
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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]
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14
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A Liquid to Solid Phase Transition Underlying Pathological Huntingtin Exon1 Aggregation. Mol Cell 2018; 70:588-601.e6. [PMID: 29754822 PMCID: PMC5971205 DOI: 10.1016/j.molcel.2018.04.007] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/08/2018] [Accepted: 04/05/2018] [Indexed: 12/31/2022]
Abstract
Huntington’s disease is caused by an abnormally long polyglutamine tract in the huntingtin protein. This leads to the generation and deposition of N-terminal exon1 fragments of the protein in intracellular aggregates. We combined electron tomography and quantitative fluorescence microscopy to analyze the structural and material properties of huntingtin exon1 assemblies in mammalian cells, in yeast, and in vitro. We found that huntingtin exon1 proteins can form reversible liquid-like assemblies, a process driven by huntingtin’s polyQ tract and proline-rich region. In cells and in vitro, the liquid-like assemblies converted to solid-like assemblies with a fibrillar structure. Intracellular phase transitions of polyglutamine proteins could play a role in initiating irreversible pathological aggregation. Aggregates of huntingtin exon1 exist in distinct liquid-like and solid-like forms Liquid-like assembly formation is driven by polyQ and proline-rich regions of exon1 The liquid-like assemblies convert into solid-like assemblies in vitro and in cells Electron tomography reveals liquid and solid assemblies have distinct structures
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15
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Katyal N, Deep S. Inhibition of GNNQQNY prion peptide aggregation by trehalose: a mechanistic view. Phys Chem Chem Phys 2018; 19:19120-19138. [PMID: 28702592 DOI: 10.1039/c7cp02912h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Deposition of amyloid fibrils is the seminal event in the pathogenesis of numerous neurodegenerative diseases. The formation of this amyloid assembly is the manifestation of a cascade of structural transitions including toxic oligomer formation in the early stages of aggregation. Thus a viable therapeutic strategy involves the use of small molecular ligands to interfere with this assembly. In this perspective, we have explored the kinetics of aggregate formation of the fibril forming GNNQQNY peptide fragment from the yeast prion protein SUP35 using multiple all atom MD simulations with explicit solvent and provided mechanistic insights into the way trehalose, an experimentally known aggregation inhibitor, modulates the aggregation pathway. The results suggest that the assimilation process is impeded by different barriers at smaller and larger oligomeric sizes: the initial one being easily surpassed at higher temperatures and peptide concentrations. The kinetic profile demonstrates that trehalose delays the aggregation process by increasing both these activation barriers, specifically the latter one. It increases the sampling of small-sized aggregates that lack the beta sheet conformation. Analysis reveals that the barrier in the growth of larger stable oligomers causes the formation of multiple stable small oligomers which then fuse together bimolecularly. The PCA of 26 properties was carried out to deconvolute the events within the temporary lag phases, which suggested dynamism in lags involving an increase in interchain contacts and burial of SASA. The predominant growth route is monomer addition, which changes to condensation on account of a large number of depolymerisation events in the presence of trehalose. The favourable interaction of trehalose specifically with the sidechain of the peptide promotes crowding of trehalose molecules in its vicinity - the combination of both these factors imparts the observed behaviour. Furthermore, increasing trehalose concentration leads to faster expulsion of water molecules than interpeptide interactions. These expelled water molecules have larger translational movement, suggesting an entropy factor to favor the assembly process. Different conformations observed under this condition suggest the role of water molecules in guiding the morphology of the aggregates as well. A similar scenario exists on increasing peptide concentration.
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Affiliation(s)
- Nidhi Katyal
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauzkhas, New Delhi, India.
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology, Delhi, Hauzkhas, New Delhi, India.
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16
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Supplemental Treatment for Huntington's Disease with miR-132 that Is Deficient in Huntington's Disease Brain. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 11:79-90. [PMID: 29858092 PMCID: PMC5852323 DOI: 10.1016/j.omtn.2018.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 02/06/2023]
Abstract
Huntington’s disease (HD) is an intractable neurodegenerative disorder caused by mutant Huntingtin (HTT) proteins that adversely affect various biomolecules and genes. MicroRNAs (miRNAs), which are functional small non-coding RNAs, are also affected by mutant HTT proteins. Here, we show amelioration in motor function and lifespan of HD-model mice, R6/2 mice, by supplying miR-132 to HD brains using a recombinant adeno-associated virus (rAAV) miRNA expression system. miR-132 is an miRNA related to neuronal maturation and function, but the level of miR-132 in the brain of R6/2 mice was significantly lower than that of wild-type mice. Our miR-132 supplemental treatment, i.e., supplying miR-132 to the brain, produced symptomatic improvement or retarded disease progression in R6/2 mice; interestingly, it had little effect on disease-causing mutant HTT mRNA expression and its products. Therefore, the findings suggest that there may be a therapeutic way to treat HD without inhibiting and/or repairing disease-causing HTT genes and gene products. Although miR-132 supplement may not be a definitive treatment for HD, it may become a therapeutic method for relieving HD symptoms and delaying HD progression.
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17
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Halbach MV, Gispert S, Stehning T, Damrath E, Walter M, Auburger G. Atxn2 Knockout and CAG42-Knock-in Cerebellum Shows Similarly Dysregulated Expression in Calcium Homeostasis Pathway. THE CEREBELLUM 2017; 16:68-81. [PMID: 26868665 PMCID: PMC5243904 DOI: 10.1007/s12311-016-0762-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominantly inherited neurodegenerative disorder with preferential affection of Purkinje neurons, which are known as integrators of calcium currents. The expansion of a polyglutamine (polyQ) domain in the RNA-binding protein ataxin-2 (ATXN2) is responsible for this disease, but the causal roles of deficient ATXN2 functions versus aggregation toxicity are still under debate. Here, we studied mouse mutants with Atxn2 knockout (KO) regarding their cerebellar global transcriptome by microarray and RT-qPCR, in comparison with data from Atxn2-CAG42-knock-in (KIN) mouse cerebellum. Global expression downregulations involved lipid and growth signaling pathways in good agreement with previous data. As a novel effect, downregulations of key factors in calcium homeostasis pathways (the transcription factor Rora, transporters Itpr1 and Atp2a2, as well as regulator Inpp5a) were observed in the KO cerebellum, and some of them also occurred subtly early in KIN cerebellum. The ITPR1 protein levels were depleted from soluble fractions of cerebellum in both mutants, but accumulated in its membrane-associated form only in the SCA2 model. Coimmunoprecipitation demonstrated no association of ITPR1 with Q42-expanded or with wild-type ATXN2. These findings provide evidence that the physiological functions and protein interactions of ATXN2 are relevant for calcium-mediated excitation of Purkinje cells as well as for ATXN2-triggered neurotoxicity. These insights may help to understand pathogenesis and tissue specificity in SCA2 and other polyQ ataxias like SCA1, where inositol regulation of calcium flux and RORalpha play a role.
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Affiliation(s)
- Melanie Vanessa Halbach
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany
| | - Suzana Gispert
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany
| | - Tanja Stehning
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany
| | - Ewa Damrath
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany
| | - Michael Walter
- Institute for Medical Genetics, Eberhard-Karls-University of Tuebingen, 72076, Tuebingen, Germany
| | - Georg Auburger
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590, Frankfurt am Main, Germany.
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18
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A brain-targeting lipidated peptide for neutralizing RNA-mediated toxicity in Polyglutamine Diseases. Sci Rep 2017; 7:12077. [PMID: 28935901 PMCID: PMC5608758 DOI: 10.1038/s41598-017-11695-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/29/2017] [Indexed: 01/11/2023] Open
Abstract
Polyglutamine (PolyQ) diseases are progressive neurodegenerative disorders caused by both protein- and RNA-mediated toxicities. We previously showed that a peptidyl inhibitor, P3, which binds directly to expanded CAG RNA can inhibit RNA-induced nucleolar stress and suppress RNA-induced neurotoxicity. Here we report a N-acetylated and C-amidated derivative of P3, P3V8, that showed a more than 20-fold increase in its affinity for expanded CAG RNA. The P3V8 peptide also more potently alleviated expanded RNA-induced cytotoxicity in vitro, and suppressed polyQ neurodegeneration in Drosophila with no observed toxic effects. Further N-palmitoylation of P3V8 (L1P3V8) not only significantly improved its cellular uptake and stability, but also facilitated its systemic exposure and brain uptake in rats via intranasal administration. Our findings demonstrate that concomitant N-acetylation, C-amidation and palmitoylation of P3 significantly improve both its bioactivity and pharmacological profile. L1P3V8 possesses drug/lead-like properties that can be further developed into a lead inhibitor for the treatment of polyQ diseases.
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19
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Roshan R, Choudhary A, Bhambri A, Bakshi B, Ghosh T, Pillai B. microRNA dysregulation in polyglutamine toxicity of TATA-box binding protein is mediated through STAT1 in mouse neuronal cells. J Neuroinflammation 2017; 14:155. [PMID: 28774347 PMCID: PMC5543588 DOI: 10.1186/s12974-017-0925-3] [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: 10/10/2016] [Accepted: 07/21/2017] [Indexed: 01/10/2023] Open
Abstract
Background Polyglutamine diseases constitute a class of neurodegenerative disorders associated with expansion of the cytosine-adenine-guanine (CAG) triplet, in protein coding genes. Expansion of a polyglutamine tract in the N-terminal of TBP is the causal mutation in SCA17. Brain sections of patients with spinocerebellar ataxia 17 (SCA17), a type of neurodegenerative disease, have been reported to contain protein aggregates of TATA-binding protein (TBP). It is also implicated in other neurodegenerative diseases like Huntington’s disease, since the protein aggregates formed in such diseases also contain TBP. Dysregulation of miR-29a/b is another common feature of neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, and SCA17. Using a cellular model of SCA17, we identified key connections in the molecular pathway from protein aggregation to miRNA dysregulation. Methods Gene expression profiling was performed subsequent to the expression of TBP containing polyglutamine in a cellular model of SCA17. We studied the expression of STAT1 and other interferon-gamma dependent genes in neuronal apoptosis. The molecular pathway leading to the dysregulation of miRNA in response of protein aggregation and interferon release was investigated using RNAi-mediated knockdown of STAT1. Results We show that the accumulation of polyglutamine-TBP in the cells results in interferon-gamma release which in turn signals through STAT1 leading to downregulation of miR-29a/b. We propose that the release of interferons by cells harboring toxic protein aggregates may trigger a bystander effect resulting in loss of neurons. Interferon-gamma also led to upregulation of miR-322 although this effect is not mediated through STAT1. Conclusions Our investigation shows that neuroinflammation could be an important player in mediating the transcriptional dysregulation of miRNA and the subsequent apoptotic effect of toxic polyglutamine-TBP. The involvement of immunomodulators in polyglutamine diseases holds special therapeutic relevance in the light of recent findings that interferon-gamma can modulate behavior.
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Affiliation(s)
- Reema Roshan
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Ashwani Choudhary
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Indian Institute of Science, Centre for Neuroscience, Bangalore, 560012, Karnataka, India
| | - Aksheev Bhambri
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research (AcSIR), Mathura Road, Delhi, 110025, India.,Present address: Indian Council of Medical Research, New Delhi, India
| | - Bhawani Bakshi
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Tanay Ghosh
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Wellcome-Medical Research Council Cambridge Stem Cell Institute, Department of Clinical Neurosciences,, University of Cambridge, Cambridge, UK
| | - Beena Pillai
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India. .,Academy of Scientific and Innovative Research (AcSIR), Mathura Road, Delhi, 110025, India.
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20
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Wen J, Scoles DR, Facelli JC. Molecular dynamics analysis of the aggregation propensity of polyglutamine segments. PLoS One 2017; 12:e0178333. [PMID: 28542401 PMCID: PMC5444867 DOI: 10.1371/journal.pone.0178333] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 05/11/2017] [Indexed: 01/09/2023] Open
Abstract
Protein misfolding and aggregation is a pathogenic feature shared among at least ten polyglutamine (polyQ) neurodegenerative diseases. While solvent-solution interaction is a key factor driving protein folding and aggregation, the solvation properties of expanded polyQ tracts are not well understood. By using GPU-enabled all-atom molecular dynamics simulations of polyQ monomers in an explicit solvent environment, this study shows that solvent-polyQ interaction propensity decreases as the lengths of polyQ tract increases. This study finds a predominance in long-distance interactions between residues far apart in polyQ sequences with longer polyQ segments, that leads to significant conformational differences. This study also indicates that large loops, comprised of parallel β-structures, appear in long polyQ tracts and present new aggregation building blocks with aggregation driven by long-distance intra-polyQ interactions. Finally, consistent with previous observations using coarse-grain simulations, this study demonstrates that there is a gain in the aggregation propensity with increased polyQ length, and that this gain is correlated with decreasing ability of solvent-polyQ interaction. These results suggest the modulation of solvent-polyQ interactions as a possible therapeutic strategy for treating polyQ diseases.
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Affiliation(s)
- Jingran Wen
- Department of Biomedical Informatics, University of Utah, Salt Lake City, Utah, United States of America
| | - Daniel R. Scoles
- Department of Neurology, University of Utah, Salt Lake City, Utah, United States of America
| | - Julio C. Facelli
- Department of Biomedical Informatics, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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21
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East DA, Campanella M. Mitophagy and the therapeutic clearance of damaged mitochondria for neuroprotection. Int J Biochem Cell Biol 2016; 79:382-387. [DOI: 10.1016/j.biocel.2016.08.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 08/20/2016] [Indexed: 12/23/2022]
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22
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An Intrabody Drug (rAAV6-INT41) Reduces the Binding of N-Terminal Huntingtin Fragment(s) to DNA to Basal Levels in PC12 Cells and Delays Cognitive Loss in the R6/2 Animal Model. JOURNAL OF NEURODEGENERATIVE DISEASES 2016; 2016:7120753. [PMID: 27595037 PMCID: PMC4995342 DOI: 10.1155/2016/7120753] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/27/2016] [Indexed: 01/01/2023]
Abstract
Huntington's disease (HD) is a fatal progressive disease linked to expansion of glutamine repeats in the huntingtin protein and characterized by the progressive loss of cognitive and motor function. We show that expression of a mutant human huntingtin exon-1-GFP fusion construct results in nonspecific gene dysregulation that is significantly reduced by 50% due to coexpression of INT41, an intrabody specific for the proline-rich region of the huntingtin protein. Using stable PC12 cell lines expressing either inducible human mutant huntingtin (mHtt, Q73) or normal huntingtin (nHtt, Q23), we investigated the effect of rAAV6-INT41, an adeno-associated virus vector with the INT41 coding sequence, on the subcellular distribution of Htt. Compartmental fractionation 8 days after induction of Htt showed a 6-fold increased association of a dominate N-terminal mHtt fragment with DNA compared to N-terminal nHtt. Transduction with rAAV6-INT41 reduced DNA binding of N-terminal mHtt 6.5-fold in the nucleus and reduced nuclear translocation of the detected fragments. Subsequently, when rAAV6-INT41 is delivered to the striatum in the R6/2 mouse model, treated female mice exhibited executive function statistically indistinguishable from wild type, accompanied by reductions in Htt aggregates in the striatum, suggesting that rAAV6-INT41 is promising as a gene therapy for Huntington's disease.
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23
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Li L, Liu H, Dong P, Li D, Legant WR, Grimm JB, Lavis LD, Betzig E, Tjian R, Liu Z. Real-time imaging of Huntingtin aggregates diverting target search and gene transcription. eLife 2016; 5. [PMID: 27484239 PMCID: PMC4972539 DOI: 10.7554/elife.17056] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/07/2016] [Indexed: 01/21/2023] Open
Abstract
The presumptive altered dynamics of transient molecular interactions in vivo contributing to neurodegenerative diseases have remained elusive. Here, using single-molecule localization microscopy, we show that disease-inducing Huntingtin (mHtt) protein fragments display three distinct dynamic states in living cells - 1) fast diffusion, 2) dynamic clustering and 3) stable aggregation. Large, stable aggregates of mHtt exclude chromatin and form 'sticky' decoy traps that impede target search processes of key regulators involved in neurological disorders. Functional domain mapping based on super-resolution imaging reveals an unexpected role of aromatic amino acids in promoting protein-mHtt aggregate interactions. Genome-wide expression analysis and numerical simulation experiments suggest mHtt aggregates reduce transcription factor target site sampling frequency and impair critical gene expression programs in striatal neurons. Together, our results provide insights into how mHtt dynamically forms aggregates and disrupts the finely-balanced gene control mechanisms in neuronal cells.
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Affiliation(s)
- Li Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,LKS Bio-medical and Health Sciences Center, CIRM Center of Excellence, University of California, Berkeley, United States
| | - Hui Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Peng Dong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Dong Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Wesley R Legant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jonathan B Grimm
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Robert Tjian
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,LKS Bio-medical and Health Sciences Center, CIRM Center of Excellence, University of California, Berkeley, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
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24
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Alves S, Marais T, Biferi MG, Furling D, Marinello M, El Hachimi K, Cartier N, Ruberg M, Stevanin G, Brice A, Barkats M, Sittler A. Lentiviral vector-mediated overexpression of mutant ataxin-7 recapitulates SCA7 pathology and promotes accumulation of the FUS/TLS and MBNL1 RNA-binding proteins. Mol Neurodegener 2016; 11:58. [PMID: 27465358 PMCID: PMC4964261 DOI: 10.1186/s13024-016-0123-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 07/21/2016] [Indexed: 12/17/2022] Open
Abstract
Background We used lentiviral vectors (LVs) to generate a new SCA7 animal model overexpressing a truncated mutant ataxin-7 (MUT ATXN7) fragment in the mouse cerebellum, in order to characterize the specific neuropathological and behavioral consequences of the genetic defect in this brain structure. Results LV-mediated overexpression of MUT ATXN7 into the cerebellum of C57/BL6 adult mice induced neuropathological features similar to that observed in patients, such as intranuclear aggregates in Purkinje cells (PC), loss of synaptic markers, neuroinflammation, and neuronal death. No neuropathological changes were observed when truncated wild-type ataxin-7 (WT ATXN7) was injected. Interestingly, the local delivery of LV-expressing mutant ataxin-7 (LV-MUT-ATXN7) into the cerebellum of wild-type mice also mediated the development of an ataxic phenotype at 8 to 12 weeks post-injection. Importantly, our data revealed abnormal levels of the FUS/TLS, MBNL1, and TDP-43 RNA-binding proteins in the cerebellum of the LV-MUT-ATXN7 injected mice. MUT ATXN7 overexpression induced an increase in the levels of the pathological phosphorylated TDP-43, and a decrease in the levels of soluble FUS/TLS, with both proteins accumulating within ATXN7-positive intranuclear inclusions. MBNL1 also co-aggregated with MUT ATXN7 in most PC nuclear inclusions. Interestingly, no MBNL2 aggregation was observed in cerebellar MUT ATXN7 aggregates. Immunohistochemical studies in postmortem tissue from SCA7 patients and SCA7 knock-in mice confirmed SCA7-induced nuclear accumulation of FUS/TLS and MBNL1, strongly suggesting that these proteins play a physiopathological role in SCA7. Conclusions This study validates a novel SCA7 mouse model based on lentiviral vectors, in which strong and sustained expression of MUT ATXN7 in the cerebellum was found sufficient to generate motor defects. Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0123-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sandro Alves
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.
| | - Thibaut Marais
- CNRS FRE3617, Center for Research in Myology, Sorbonne Universités UPMC Univ Paris 06, INSERM UMRS974, Institut de Myologie, G-H Pitié-Salpêtrière, 75013, Paris, France
| | - Maria-Grazia Biferi
- CNRS FRE3617, Center for Research in Myology, Sorbonne Universités UPMC Univ Paris 06, INSERM UMRS974, Institut de Myologie, G-H Pitié-Salpêtrière, 75013, Paris, France
| | - Denis Furling
- CNRS FRE3617, Center for Research in Myology, Sorbonne Universités UPMC Univ Paris 06, INSERM UMRS974, Institut de Myologie, G-H Pitié-Salpêtrière, 75013, Paris, France
| | - Martina Marinello
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.,EPHE Ecole Pratique des Hautes Etudes, Laboratoire de Neurogénétique, PSL Universités, 75013, Paris, France
| | - Khalid El Hachimi
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.,EPHE Ecole Pratique des Hautes Etudes, Laboratoire de Neurogénétique, PSL Universités, 75013, Paris, France
| | | | - Merle Ruberg
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France
| | - Giovanni Stevanin
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.,EPHE Ecole Pratique des Hautes Etudes, Laboratoire de Neurogénétique, PSL Universités, 75013, Paris, France.,Département de Génétique et Cytogénétique, AP-HP, G-H Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Alexis Brice
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.,Département de Génétique et Cytogénétique, AP-HP, G-H Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75013, Paris, France
| | - Martine Barkats
- CNRS FRE3617, Center for Research in Myology, Sorbonne Universités UPMC Univ Paris 06, INSERM UMRS974, Institut de Myologie, G-H Pitié-Salpêtrière, 75013, Paris, France
| | - Annie Sittler
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités UPMC, Univ Paris 06 UMR_S 1127, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013, Paris, France.
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25
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Hwang S, Disatnik MH, Mochly-Rosen D. Impaired GAPDH-induced mitophagy contributes to the pathology of Huntington's disease. EMBO Mol Med 2016; 7:1307-26. [PMID: 26268247 PMCID: PMC4604685 DOI: 10.15252/emmm.201505256] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial dysfunction is implicated in multiple neurodegenerative diseases. In order to maintain a healthy population of functional mitochondria in cells, defective mitochondria must be properly eliminated by lysosomal machinery in a process referred to as mitophagy. Here, we uncover a new molecular mechanism underlying mitophagy driven by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) under the pathological condition of Huntington’s disease (HD) caused by expansion of polyglutamine repeats. Expression of expanded polyglutamine tracts catalytically inactivates GAPDH (iGAPDH), which triggers its selective association with damaged mitochondria in several cell culture models of HD. Through this mechanism, iGAPDH serves as a signaling molecule to induce direct engulfment of damaged mitochondria into lysosomes (micro-mitophagy). However, abnormal interaction of mitochondrial GAPDH with long polyglutamine tracts stalled GAPDH-mediated mitophagy, leading to accumulation of damaged mitochondria, and increased cell death. We further demonstrated that overexpression of inactive GAPDH rescues this blunted process and enhances mitochondrial function and cell survival, indicating a role for GAPDH-driven mitophagy in the pathology of HD.
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Affiliation(s)
- Sunhee Hwang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Marie-Hélène Disatnik
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
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26
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Glycogen synthase kinase 3β suppresses polyglutamine aggregation by inhibiting Vaccinia-related kinase 2 activity. Sci Rep 2016; 6:29097. [PMID: 27377031 PMCID: PMC4932512 DOI: 10.1038/srep29097] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/09/2016] [Indexed: 12/19/2022] Open
Abstract
Huntington’s disease (HD) is a neurodegenerative disorder caused by an abnormal expansion of polyglutamine repeats in the N-terminal of huntingtin. The amount of aggregate-prone protein is controlled by various mechanisms, including molecular chaperones. Vaccinia-related kinase 2 (VRK2) is known to negatively regulate chaperonin TRiC, and VRK2-facilitated degradation of TRiC increases polyQ protein aggregation, which is involved in HD. We found that VRK2 activity was negatively controlled by glycogen synthase kinase 3β (GSK3β). GSK3β directly bound to VRK2 and inhibited the catalytic activity of VRK2 in a kinase activity-independent manner. Furthermore, GSK3β increased the stability of TRiC and decreased the formation of HttQ103-GFP aggregates by inhibiting VRK2. These results indicate that GSK3β signaling may be a regulatory mechanism of HD progression and suggest targets for further therapeutic trials for HD.
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27
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He WT, Zheng XM, Zhang YH, Gao YG, Song AX, van der Goot FG, Hu HY. Cytoplasmic Ubiquitin-Specific Protease 19 (USP19) Modulates Aggregation of Polyglutamine-Expanded Ataxin-3 and Huntingtin through the HSP90 Chaperone. PLoS One 2016; 11:e0147515. [PMID: 26808260 PMCID: PMC4726498 DOI: 10.1371/journal.pone.0147515] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 01/05/2016] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin-specific protease 19 (USP19) is one of the deubiquitinating enzymes (DUBs) involved in regulating the ubiquitination status of substrate proteins. There are two major isoforms of USP19 with distinct C-termini; the USP19_a isoform has a transmembrane domain for anchoring to the endoplasmic reticulum, while USP19_b contains an EEVD motif. Here, we report that the cytoplasmic isoform USP19_b up-regulates the protein levels of the polyglutamine (polyQ)-containing proteins, ataxin-3 (Atx3) and huntingtin (Htt), and thus promotes aggregation of their polyQ-expanded species in cell models. Our data demonstrate that USP19_b may orchestrate the stability, aggregation and degradation of the polyQ-expanded proteins through the heat shock protein 90 (HSP90) chaperone system. USP19_b directly interacts with HSP90 through its N-terminal CS (CHORD and SGT1)/P23 domains. In conjunction with HSP90, the cytoplasmic USP19 may play a key role in triage decision for the disease-related polyQ-expanded substrates, suggesting a function of USP19 in quality control of misfolded proteins by regulating their protein levels.
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Affiliation(s)
- Wen-Tian He
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xue-Ming Zheng
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Department of Biochemistry and Molecular Biology, School of Medical Technology, Jiangsu University, Zhenjiang 212013, Jiangsu, China
| | - Yu-Hang Zhang
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yong-Guang Gao
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ai-Xin Song
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | | | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- * E-mail:
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28
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Arimoto-Matsuzaki K, Saito H, Takekawa M. TIA1 oxidation inhibits stress granule assembly and sensitizes cells to stress-induced apoptosis. Nat Commun 2016; 7:10252. [PMID: 26738979 PMCID: PMC4729832 DOI: 10.1038/ncomms10252] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 11/20/2015] [Indexed: 12/24/2022] Open
Abstract
Cytoplasmic stress granules (SGs) are multimolecular aggregates of stalled translation pre-initiation complexes that prevent the accumulation of misfolded proteins, and that are formed in response to certain types of stress including ER stress. SG formation contributes to cell survival not only by suppressing translation but also by sequestering some apoptosis regulatory factors. Because cells can be exposed to various stresses simultaneously in vivo, the regulation of SG assembly under multiple stress conditions is important but unknown. Here we report that reactive oxygen species (ROS) such as H2O2 oxidize the SG-nucleating protein TIA1, thereby inhibiting SG assembly. Thus, when cells are confronted with a SG-inducing stress such as ER stress caused by protein misfolding, together with ROS-induced oxidative stress, they cannot form SGs, resulting in the promotion of apoptosis. We demonstrate that the suppression of SG formation by oxidative stress may underlie the neuronal cell death seen in neurodegenerative diseases. Cytoplasmic stress granules (SG) are intracellular aggregates that suppress translation and sequester apoptosis regulatory factors. Here the authors show that reactive oxygen species oxidise the SG-nucleating protein TIA1, preventing SG formation and promoting apoptosis in the presence of additional stress.
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Affiliation(s)
- Kyoko Arimoto-Matsuzaki
- Division of Molecular Cell Signaling, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Haruo Saito
- Division of Molecular Cell Signaling, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Mutsuhiro Takekawa
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
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29
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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.
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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.
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30
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Dictyostelium discoideum has a highly Q/N-rich proteome and shows an unusual resilience to protein aggregation. Proc Natl Acad Sci U S A 2015; 112:E2620-9. [PMID: 25941378 DOI: 10.1073/pnas.1504459112] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Many protein-misfolding diseases are caused by proteins carrying prion-like domains. These proteins show sequence similarity to yeast prion proteins, which can interconvert between an intrinsically disordered and an aggregated prion state. The natural presence of prions in yeast has provided important insight into disease mechanisms and cellular proteostasis. However, little is known about prions in other organisms, and it is not yet clear whether the findings in yeast can be generalized. Using bioinformatics tools, we show that Dictyostelium discoideum has the highest content of prion-like proteins of all organisms investigated to date, suggesting that its proteome has a high overall aggregation propensity. To study mechanisms regulating these proteins, we analyze the behavior of several well-characterized prion-like proteins, such as an expanded version of human huntingtin exon 1 (Q103) and the prion domain of the yeast prion protein Sup35 (NM), in D. discoideum. We find that these proteins remain soluble and are innocuous to D. discoideum, in contrast to other organisms, where they form cytotoxic cytosolic aggregates. However, when exposed to conditions that compromise molecular chaperones, these proteins aggregate and become cytotoxic. We show that the disaggregase Hsp101, a molecular chaperone of the Hsp100 family, dissolves heat-induced aggregates and promotes thermotolerance. Furthermore, prion-like proteins accumulate in the nucleus, where they are targeted by the ubiquitin-proteasome system. Our data suggest that D. discoideum has undergone specific adaptations that increase the proteostatic capacity of this organism and allow for an efficient regulation of its prion-like proteome.
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31
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Wen J, Scoles DR, Facelli JC. Structure prediction of polyglutamine disease proteins: comparison of methods. BMC Bioinformatics 2014; 15 Suppl 7:S11. [PMID: 25080018 PMCID: PMC4110737 DOI: 10.1186/1471-2105-15-s7-s11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Background The expansion of polyglutamine (poly-Q) repeats in several unrelated proteins is associated with at least ten neurodegenerative diseases. The length of the poly-Q regions plays an important role in the progression of the diseases. The number of glutamines (Q) is inversely related to the onset age of these polyglutamine diseases, and the expansion of poly-Q repeats has been associated with protein misfolding. However, very little is known about the structural changes induced by the expansion of the repeats. Computational methods can provide an alternative to determine the structure of these poly-Q proteins, but it is important to evaluate their performance before large scale prediction work is done. Results In this paper, two popular protein structure prediction programs, I-TASSER and Rosetta, have been used to predict the structure of the N-terminal fragment of a protein associated with Huntington's disease with 17 glutamines. Results show that both programs have the ability to find the native structures, but I-TASSER performs better for the overall task. Conclusions Both I-TASSER and Rosetta can be used for structure prediction of proteins with poly-Q repeats. Knowledge of poly-Q structure may significantly contribute to development of therapeutic strategies for poly-Q diseases.
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32
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Tezenas du Montcel S, Durr A, Bauer P, Figueroa KP, Ichikawa Y, Brussino A, Forlani S, Rakowicz M, Schöls L, Mariotti C, van de Warrenburg BPC, Orsi L, Giunti P, Filla A, Szymanski S, Klockgether T, Berciano J, Pandolfo M, Boesch S, Melegh B, Timmann D, Mandich P, Camuzat A, Goto J, Ashizawa T, Cazeneuve C, Tsuji S, Pulst SM, Brusco A, Riess O, Brice A, Stevanin G. Modulation of the age at onset in spinocerebellar ataxia by CAG tracts in various genes. ACTA ACUST UNITED AC 2014; 137:2444-55. [PMID: 24972706 DOI: 10.1093/brain/awu174] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Polyglutamine-coding (CAG)n repeat expansions in seven different genes cause spinocerebellar ataxias. Although the size of the expansion is negatively correlated with age at onset, it accounts for only 50-70% of its variability. To find other factors involved in this variability, we performed a regression analysis in 1255 affected individuals with identified expansions (spinocerebellar ataxia types 1, 2, 3, 6 and 7), recruited through the European Consortium on Spinocerebellar Ataxias, to determine whether age at onset is influenced by the size of the normal allele in eight causal (CAG)n-containing genes (ATXN1-3, 6-7, 17, ATN1 and HTT). We confirmed the negative effect of the expanded allele and detected threshold effects reflected by a quadratic association between age at onset and CAG size in spinocerebellar ataxia types 1, 3 and 6. We also evidenced an interaction between the expanded and normal alleles in trans in individuals with spinocerebellar ataxia types 1, 6 and 7. Except for individuals with spinocerebellar ataxia type 1, age at onset was also influenced by other (CAG)n-containing genes: ATXN7 in spinocerebellar ataxia type 2; ATXN2, ATN1 and HTT in spinocerebellar ataxia type 3; ATXN1 and ATXN3 in spinocerebellar ataxia type 6; and ATXN3 and TBP in spinocerebellar ataxia type 7. This suggests that there are biological relationships among these genes. The results were partially replicated in four independent populations representing 460 Caucasians and 216 Asian samples; the differences are possibly explained by ethnic or geographical differences. As the variability in age at onset is not completely explained by the effects of the causative and modifier sister genes, other genetic or environmental factors must also play a role in these diseases.
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Affiliation(s)
- Sophie Tezenas du Montcel
- 1 Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France2 INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, F-75013, Paris, France3 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Biostatistics Unit, Paris, F-75013, France
| | - Alexandra Durr
- 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Department of Genetics and Cytogenetics, F-75013, Paris, France5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Peter Bauer
- 6 Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Karla P Figueroa
- 7 Department of Neurology, University of Utah, Salt Lake City, USA
| | - Yaeko Ichikawa
- 8 Department of Neurology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan
| | - Alessandro Brussino
- 9 University of Torino, Department of Medical Sciences, and Medical Genetics Unit, Az. Osp. 'Città della Salute e della Scienza', Torino, Italy
| | - Sylvie Forlani
- 5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Maria Rakowicz
- 10 Institute of Psychiatry and Neurology Warsaw, Sobieskiego 9, 02-957 Warsaw, Poland
| | - Ludger Schöls
- 11 Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany12 German Centre of Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Caterina Mariotti
- 13 SOSD Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS, Istituto Neurologico 'Carlo Besta', Milan, Italy
| | - Bart P C van de Warrenburg
- 14 Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radbound University Medical Centre, Nijmegen, The Netherlands
| | - Laura Orsi
- 15 Neurologic Division I, Department of Neuroscience and Mental Health, AOU Città della Salute e della Scienza, Torino, Italy
| | - Paola Giunti
- 16 Institute of Neurology, Department of Molecular Neuroscience, UCL, Queen Square, London, UK
| | - Alessandro Filla
- 17 Department of Neurological Sciences, Federico II University, Naples, Italy
| | - Sandra Szymanski
- 18 Department of Neurology, St. Josef Hospital, University Hospital of Bochum, Bochum, Germany
| | | | - José Berciano
- 20 Department of Neurology, University Hospital 'Marqués de Valdecilla', UC, IDIVAL and CIBERNED, 39008 Santander, Spain
| | - Massimo Pandolfo
- 21 Department of Neurology, ULB-Hôpital Erasme, Université Libre de Bruxelles, CP 231, Campus Plaine, ULB, Brusssels, Belgium
| | - Sylvia Boesch
- 22 Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Bela Melegh
- 23 Department of Medical Genetics, and Szentagothai Research Centre, University Pécs, Hungary
| | - Dagmar Timmann
- 24 Department of Neurology, University Clinic Essen, University of Duisburg-Essen, Essen, Germany
| | - Paola Mandich
- 25 Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genova, and U.O. Medical Genetics of IRCCS AOU S. Martino Institute, Genova, Italy
| | - Agnès Camuzat
- 5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | | | | | - Jun Goto
- 8 Department of Neurology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan
| | - Tetsuo Ashizawa
- 26 Department of Neurology and McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Cécile Cazeneuve
- 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Department of Genetics and Cytogenetics, F-75013, Paris, France
| | - Shoji Tsuji
- 8 Department of Neurology, University of Tokyo, Graduate School of Medicine, Tokyo, Japan
| | - Stefan-M Pulst
- 7 Department of Neurology, University of Utah, Salt Lake City, USA
| | - Alfredo Brusco
- 9 University of Torino, Department of Medical Sciences, and Medical Genetics Unit, Az. Osp. 'Città della Salute e della Scienza', Torino, Italy
| | - Olaf Riess
- 6 Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Alexis Brice
- 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Department of Genetics and Cytogenetics, F-75013, Paris, France5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France
| | - Giovanni Stevanin
- 4 AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Department of Genetics and Cytogenetics, F-75013, Paris, France5 Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France27 Ecole Pratique des Hautes Etudes, heSam Université, laboratoire de neurogénétique, ICM, Groupe Hospitalier Pitié-Salpêtrière, F-75013 Paris, France
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33
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Sahoo B, Singer D, Kodali R, Zuchner T, Wetzel R. Aggregation behavior of chemically synthesized, full-length huntingtin exon1. Biochemistry 2014; 53:3897-907. [PMID: 24921664 PMCID: PMC4075985 DOI: 10.1021/bi500300c] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Repeat
length disease thresholds vary among the 10 expanded polyglutamine
(polyQ) repeat diseases, from about 20 to about 50 glutamine residues.
The unique amino acid sequences flanking the polyQ segment are thought
to contribute to these repeat length thresholds. The specific portions
of the flanking sequences that modulate polyQ properties are not always
clear, however. This ambiguity may be important in Huntington’s
disease (HD), for example, where in vitro studies
of aggregation mechanisms have led to distinctly different mechanistic
models. Most in vitro studies of the aggregation
of the huntingtin (HTT) exon1 fragment implicated in the HD mechanism
have been conducted on inexact molecules that are imprecise either
on the N-terminus (recombinantly produced peptides) or on the C-terminus
(chemically synthesized peptides). In this paper, we investigate the
aggregation properties of chemically synthesized HTT exon1 peptides
that are full-length and complete, containing both normal and expanded
polyQ repeat lengths, and compare the results directly to previously
investigated molecules containing truncated C-termini. The results
on the full-length peptides are consistent with a two-step aggregation
mechanism originally developed based on studies of the C-terminally
truncated analogues. Thus, we observe relatively rapid formation of
spherical oligomers containing from 100 to 600 HTT exon1 molecules
and intermediate formation of short protofibril-like structures containing
from 500 to 2600 molecules. In contrast to this relatively rapid assembly,
mature HTT exon1 amyloid requires about one month to dissociate in vitro, which is similar to the time required for neuronal
HTT exon1 aggregates to disappear in vivo after HTT
production is discontinued.
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Affiliation(s)
- Bankanidhi Sahoo
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15260, United States
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Mohan RD, Abmayr SM, Workman JL. Pulling complexes out of complex diseases: Spinocerebellar Ataxia 7. Rare Dis 2014; 2:e28859. [PMID: 25054097 PMCID: PMC4091419 DOI: 10.4161/rdis.28859] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/06/2014] [Accepted: 04/11/2014] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia 7 (SCA7) is an incurable disease caused by expansion of CAG trinucleotide sequences within the Ataxin-7 gene. This elongated CAG tract results in an Ataxin-7 protein bearing an expanded polyglutamine (PolyQ) repeat. SCA7 disease is characterized by progressive neural and retinal degeneration leading to ataxia and blindness. Evidence gathered from investigating SCA7 and other PolyQ diseases strongly suggest that misregulation of gene expression contributes to neurodegeneration. In fact, Ataxin-7 is a subunit of the essential Spt-Ada-Gcn5-Acetltransferase (SAGA) chromatin modifying complex that regulates expression of a large number of genes. Here we discuss recent insights into Ataxin-7 function and, considering these findings, propose a model for how polyglutamine expansion of Ataxin-7 may affect Ataxin-7 function to alter chromatin modifications and gene expression.
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Affiliation(s)
- Ryan D Mohan
- Stowers Institute for Medical Research; Kansas City, MO USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research; Kansas City, MO USA
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35
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Regulation of autophagy by mTOR-dependent and mTOR-independent pathways: autophagy dysfunction in neurodegenerative diseases and therapeutic application of autophagy enhancers. Biochem Soc Trans 2014; 41:1103-30. [PMID: 24059496 DOI: 10.1042/bst20130134] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autophagy is an intracellular degradation pathway essential for cellular and energy homoeostasis. It functions in the clearance of misfolded proteins and damaged organelles, as well as recycling of cytosolic components during starvation to compensate for nutrient deprivation. This process is regulated by mTOR (mammalian target of rapamycin)-dependent and mTOR-independent pathways that are amenable to chemical perturbations. Several small molecules modulating autophagy have been identified that have potential therapeutic application in diverse human diseases, including neurodegeneration. Neurodegeneration-associated aggregation-prone proteins are predominantly degraded by autophagy and therefore stimulating this process with chemical inducers is beneficial in a wide range of transgenic disease models. Emerging evidence indicates that compromised autophagy contributes to the aetiology of various neurodegenerative diseases related to protein conformational disorders by causing the accumulation of mutant proteins and cellular toxicity. Combining the knowledge of autophagy dysfunction and the mechanism of drug action may thus be rational for designing targeted therapy. The present review describes the cellular signalling pathways regulating mammalian autophagy and highlights the potential therapeutic application of autophagy inducers in neurodegenerative disorders.
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36
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Papáčková Z, Cahová M. Important role of autophagy in regulation of metabolic processes in health, disease and aging. Physiol Res 2014; 63:409-20. [PMID: 24702497 DOI: 10.33549/physiolres.932684] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Autophagy is the basic catabolic mechanism that involves degradation of dysfunctional cellular components through the action of lysosome as well as supplying energy and compounds for the synthesis of essential biomacromolecules. This process enables cells to survive stress from the external environment like nutrient deprivation. Autophagy is important in the breakdown of proteins, carbohydrates and lipids as well. Furthermore, recent studies have shown that autophagy is critical in wide range of normal human physiological processes, and defective autophagy is associated with diverse diseases, including lysosomal storage disease, myopathies, neurodegeneration and various metabolic disorders. This review summarizes the most up-to-date findings on what role autophagy plays in metabolism.
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Affiliation(s)
- Z Papáčková
- Institute for Clinical and Experimental Medicine, Department of Metabolism and Diabetes, Prague, Czech Republic.
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37
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Landrum E, Wetzel R. Biophysical underpinnings of the repeat length dependence of polyglutamine amyloid formation. J Biol Chem 2014; 289:10254-10260. [PMID: 24596088 DOI: 10.1074/jbc.c114.552943] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
There are now 10 expanded CAG repeat diseases in which both disease risk and age of onset are strongly dependent on the repeat length of the polyglutamine (polyQ) sequence in the disease protein. Large, polyQ-rich inclusions in patient brains and in cell and animal models are consistent with the involvement of polyQ aggregation in the disease mechanism. This possibility is reinforced by studies showing strong repeat length dependence to the aggregation process, qualitatively mirroring the repeat length dependence of disease risk. Our understanding of the underlying biophysical principles that mediate the repeat length dependence of aggregation, however, is far from complete. A previous study of simple polyQ peptides showed that N*, the size of the critical nucleus that controls onset of aggregation, decreases from unfavorable tetramer to favorable monomer over the range Q23 to Q26. These data, however, do not explain why, for all peptides exhibiting N* ∼ 1, spontaneous aggregation rates continue to increase with increasing repeat length. Here we describe a novel kinetics analyses that maps out the nonlinear dependence with repeat length of a nucleation efficiency term that is likely related to aspects of nucleus structure. This trend accounts for why nucleus size increases to tetrameric at repeat lengths of Q23 or below. Intriguingly, both aggregation and age of onset trend with repeat length in similar ways, exhibiting large changes per added Gln at low repeat lengths and small changes per added Gln at relatively long repeat lengths. Fibril stability also increases with repeat length in a nonlinear fashion.
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Affiliation(s)
- Elizabeth Landrum
- Department of Structural Biology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Ronald Wetzel
- Department of Structural Biology and the Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260.
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Sancho M, Herrera AE, Orzáez M, Pérez-Payá E. Inactivation of Apaf1 reduces the formation of mutant huntingtin-dependent aggregates and cell death. Neuroscience 2014; 262:83-91. [PMID: 24412373 DOI: 10.1016/j.neuroscience.2013.12.062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 12/20/2013] [Accepted: 12/27/2013] [Indexed: 10/25/2022]
Abstract
Polyglutamine expansions in some proteins associated with neurodegenerative diseases, such as Huntington's disease or several ataxias, lead to insoluble aggregates in the cell. These aggregates accumulate through a mechanism that is not yet fully understood, but it activates cell death pathways and contributes to kill the cell. Here, we show that apoptotic protease activating factor 1 (Apaf1) down-regulation, or treatment with pharmacological Apaf1 inhibitor SVT016426, decreases both polyglutamine-induced aggregation and polyglutamine-induced apoptotic cell death in different cellular models. We demonstrate that Apaf1 binds to both Htt and to heat shock protein chaperone Hsp70, and that this interaction is altered in the presence of the pharmacological inhibitor of Apaf1. Based on our findings, we hypothesize that Apaf1 enhances polyglutamine aggregation by reducing the cellular protein levels of available functional Hsp70.
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Affiliation(s)
- M Sancho
- Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain
| | - A E Herrera
- Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain
| | - M Orzáez
- Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain.
| | - E Pérez-Payá
- Laboratory of Peptide and Protein Chemistry, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain; Instituto de Biomedicina de Valencia, IBV-CSIC, E-46010 Valencia, Spain
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Long Z, Tang B, Jiang H. Alleviating neurodegeneration in Drosophila models of PolyQ diseases. CEREBELLUM & ATAXIAS 2014; 1:9. [PMID: 26331033 PMCID: PMC4552282 DOI: 10.1186/2053-8871-1-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Accepted: 05/06/2014] [Indexed: 11/23/2022]
Abstract
Polyglutamine (polyQ) diseases are a group of neurodegenerative conditions, induced from CAG trinucleotide repeat expansion within causative gene respectively. Generation of toxic proteins, containing polyQ-expanded tract, is the key process to cause neurodegeneration. Till now, although polyQ diseases remain uncurable, numerous therapeutic strategies with great potential have been examined and have been proven to be effective against polyQ diseases, including diverse small biological molecules and many pharmacological compounds mainly through prevention on formation of aggregates and inclusions, acceleration on degradation of toxic proteins and regulation of cellular function. We review promising therapeutic strategies by using Drosophila models of polyQ diseases including HD, SCA1, SCA3 and SBMA.
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Affiliation(s)
- Zhe Long
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya road, Changsha, 410008 Hunan China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya road, Changsha, 410008 Hunan China ; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, 87 Xiangya road, Changsha, 410008 Hunan China ; State Key Laboratory of Medical Genetics, Central South University, 110 Xiangyaroad, Changsha, 410078 Hunan China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya road, Changsha, 410008 Hunan China ; Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, 87 Xiangya road, Changsha, 410008 Hunan China ; State Key Laboratory of Medical Genetics, Central South University, 110 Xiangyaroad, Changsha, 410078 Hunan China
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Evans-Galea MV, Hannan AJ, Carrodus N, Delatycki MB, Saffery R. Epigenetic modifications in trinucleotide repeat diseases. Trends Mol Med 2013; 19:655-63. [DOI: 10.1016/j.molmed.2013.07.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 07/12/2013] [Accepted: 07/22/2013] [Indexed: 12/18/2022]
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Strnad P, Nuraldeen R, Guldiken N, Hartmann D, Mahajan V, Denk H, Haybaeck J. Broad Spectrum of Hepatocyte Inclusions in Humans, Animals, and Experimental Models. Compr Physiol 2013; 3:1393-436. [DOI: 10.1002/cphy.c120032] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Neurodegeneration caused by polyglutamine expansion is regulated by P-glycoprotein in Drosophila melanogaster. Genetics 2013; 195:857-70. [PMID: 24037265 DOI: 10.1534/genetics.113.155077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Trinucleotide CAG repeat disorders are caused by expansion of polyglutamine (polyQ) domains in certain proteins leading to fatal neurodegenerative disorders and are characterized by accumulation of inclusion bodies in the neurons. Clearance of these inclusion bodies holds the key to improve the disease phenotypes, which affects basic cellular processes such as transcription, protein degradation and cell signaling. In the present study, we show that P-glycoprotein (P-gp), originally identified as a causative agent of multidrug-resistant cancer cells, plays an important role in ameliorating the disease phenotype. Using a Drosophila transgenic strain that expresses a stretch of 127 glutamine repeats, we demonstrate that enhancing P-gp levels reduces eye degeneration caused by expression of polyQ, whereas reducing it increases the severity of the disease. Increase in polyQ inclusion bodies represses the expression of mdr genes, suggesting a functional link between P-gp and polyQ. P-gp up-regulation restores the defects in the actin organization and precise array of the neuronal connections caused by inclusion bodies. β-Catenin homolog, Armadillo, also interacts with P-gp and regulates the accumulation of inclusion bodies. These results thus show that P-gp and polyQ interact with each other, and changing P-gp levels can directly affect neurodegeneration.
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Todd TW, Lim J. Aggregation formation in the polyglutamine diseases: protection at a cost? Mol Cells 2013; 36:185-94. [PMID: 23794019 PMCID: PMC3800151 DOI: 10.1007/s10059-013-0167-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 06/02/2013] [Indexed: 12/30/2022] Open
Abstract
Mutant protein aggregation is a hallmark of many neurodegenerative diseases, including the polyglutamine disorders. Although the correlation between aggregation formation and disease pathology originally suggested that the visible inclusions seen in patient tissue might directly contribute to pathology, additional studies failed to confirm this hypothesis. Current opinion in the field of polyglutamine disease research now favors a model in which large inclusions are cytoprotective and smaller oligomers or misfolded monomers underlie pathogenesis. Nonetheless, therapies aimed at reducing or preventing aggregation show promise. This review outlines the debate about the role of aggregation in the polyglutamine diseases as it has unfolded in the literature and concludes with a brief discussion on the manipulation of aggregation formation and clearance mechanisms as a means of therapeutic intervention.
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Affiliation(s)
- Tiffany W. Todd
- Department of Genetics, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Janghoo Lim
- Department of Genetics, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA
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Mechanisms of RNA-induced toxicity in CAG repeat disorders. Cell Death Dis 2013; 4:e752. [PMID: 23907466 PMCID: PMC3763438 DOI: 10.1038/cddis.2013.276] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/21/2013] [Accepted: 06/28/2013] [Indexed: 01/27/2023]
Abstract
Several inherited neurodegenerative disorders are caused by CAG trinucleotide repeat expansions, which can be located either in the coding region or in the untranslated region (UTR) of the respective genes. Polyglutamine diseases (polyQ diseases) are caused by an expansion of a stretch of CAG repeats within the coding region, translating into a polyQ tract. The polyQ tract expansions result in conformational changes, eventually leading to aggregate formation. It is widely believed that the aggregation of polyQ proteins is linked with disease development. In addition, in the last couple of years, it has been shown that RNA-mediated mechanisms also have a profound role in neurotoxicity in both polyQ diseases and diseases caused by elongated CAG repeat motifs in their UTRs. Here, we review the different molecular mechanisms assigned to mRNAs with expanded CAG repeats. One aspect is the mRNA folding of CAG repeats. Furthermore, pathogenic mechanisms assigned to CAG repeat mRNAs are discussed. First, we discuss mechanisms that involve the sequestration of the diverse proteins to the expanded CAG repeat mRNA molecules. As a result of this, several cellular mechanisms are aberrantly regulated. These include the sequestration of MBNL1, leading to misregulated splicing; sequestration of nucleolin, leading to reduced cellular rRNA; and sequestration of proteins of the siRNA machinery, resulting in the production of short silencing RNAs that affect gene expression. Second, we discuss the effect of expanded CAG repeats on the subcellular localization, transcription and translation of the CAG repeat mRNA itself. Here we focus on the MID1 protein complex that triggers an increased translation of expanded CAG repeat mRNAs and a mechanism called repeat-associated non-ATG translation, which leads to proteins aberrantly translated from CAG repeat mRNAs. In addition, therapeutic approaches for CAG repeat disorders are discussed. Together, all the findings summarized here show that mutant mRNA has a fundamental role in the pathogenesis of CAG repeat diseases.
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Popiel HA, Takeuchi T, Burke JR, Strittmatter WJ, Toda T, Wada K, Nagai Y. Inhibition of protein misfolding/aggregation using polyglutamine binding peptide QBP1 as a therapy for the polyglutamine diseases. Neurotherapeutics 2013; 10:440-6. [PMID: 23504628 PMCID: PMC3701761 DOI: 10.1007/s13311-013-0184-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Protein misfolding and aggregation in the brain have been recognized to be crucial in the pathogenesis of various neurodegenerative diseases, including Alzheimer's, Parkinson's, and the polyglutamine (polyQ) diseases, which are collectively called the "protein misfolding diseases". In the polyQ diseases, an abnormally expanded polyQ stretch in the responsible proteins causes the proteins to misfold and aggregate, eventually resulting in neurodegeneration. Hypothesizing that polyQ protein misfolding and aggregation could be inhibited by molecules specifically binding to the expanded polyQ stretch, we identified polyQ binding peptide 1 (QBP1). We show that QBP1 does, indeed, inhibit misfolding and aggregation of the expanded polyQ protein in vitro. Furthermore overexpression of QBP1 by the crossing of transgenic animals inhibits neurodegeneration in Drosophila models of the polyQ diseases. We also introduce our attempts to deliver QBP1 into the brain by administration using viral vectors and protein transduction domains. Interestingly, recent data suggest that QBP1 can also inhibit the misfolding/aggregation of proteins responsible for other protein misfolding diseases, highlighting the potential of QBP1 as a general therapeutic molecule for a wide range of neurodegenerative diseases. We hope that in the near future, aggregation inhibitor-based drugs will be developed and bring relief to patients suffering from these currently intractable protein misfolding diseases.
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Affiliation(s)
- H. Akiko Popiel
- />Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa Higashi, Kodaira, Tokyo 187-8502 Japan
| | - Toshihide Takeuchi
- />Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa Higashi, Kodaira, Tokyo 187-8502 Japan
| | - James R. Burke
- />Department of Medicine (Neurology) and Deane Laboratory, Duke University Medical Center, Durham, NC 27710 USA
| | - Warren J. Strittmatter
- />Department of Medicine (Neurology) and Deane Laboratory, Duke University Medical Center, Durham, NC 27710 USA
| | - Tatsushi Toda
- />Division of Neurology/Molecular Brain Science, Kobe University Graduate School of Medicine, Kobe, 650-0017 Japan
| | - Keiji Wada
- />Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa Higashi, Kodaira, Tokyo 187-8502 Japan
| | - Yoshitaka Nagai
- />Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa Higashi, Kodaira, Tokyo 187-8502 Japan
- />Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Saitama, 332-0012 Japan
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Guan WJ, Xia KD, Ma YT, Liu YT, Shi YT, Jiang H, Shen L, Xia K, Li JD, Tang BS, Wang JL. Transglutaminase 6 interacts with polyQ proteins and promotes the formation of polyQ aggregates. Biochem Biophys Res Commun 2013; 437:94-100. [DOI: 10.1016/j.bbrc.2013.06.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 06/13/2013] [Indexed: 01/07/2023]
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Sharma S, Singh TD, Poojary SS, Rohilla MS, Singh A, Lowalekar KB, Tiwari PK. Analysis of autosomal dominant spinocerebellar ataxia type 1 in an extended family of central India. INDIAN JOURNAL OF HUMAN GENETICS 2013; 18:299-304. [PMID: 23716937 PMCID: PMC3656518 DOI: 10.4103/0971-6866.107981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Spinocerebeller ataxia type 1 (SCA1) is a specific type of ataxia among a group of inherited diseases of the central nervous system. In SCA1, genetic defects lead to impairment of specific nerve fibers carrying messages to and from the brain, resulting in the degeneration of the cerebellum, the coordination center of the brain. We investigated 24 members of an extended family in Gwalior city, India, some of which were earlier clinically diagnosed to be suffering from yet unconfirmed type of SCA neurodegenerative disorder. MATERIALS AND METHODS All the family members from each age group were screened clinically and the characteristics of those resembling with ataxia were recorded for diagnosis by MRI. The confirmed patients of the family were genetically tested by PCR based molecular testing to identify the type of SCA (i.e., SCA 1, 2, 3, 4, 6 or 7). Family tree of the disease inheritance was constructed by pedigree based method. RESULT AND CONCLUSION We found the clinical (symptoms and MRI) and genetic (Pedigree and PCR) results to be correlated. The PCR result revealed the disease to be of SCA 1 type being inherited in the family.
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Nguyen HP, Hübener J, Weber JJ, Grueninger S, Riess O, Weiss A. Cerebellar soluble mutant ataxin-3 level decreases during disease progression in Spinocerebellar Ataxia Type 3 mice. PLoS One 2013; 8:e62043. [PMID: 23626768 PMCID: PMC3633920 DOI: 10.1371/journal.pone.0062043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/17/2013] [Indexed: 02/02/2023] Open
Abstract
Spinocerebellar Ataxia Type 3 (SCA3), also known as Machado-Joseph disease, is an autosomal dominantly inherited neurodegenerative disease caused by an expanded polyglutamine stretch in the ataxin-3 protein. A pathological hallmark of the disease is cerebellar and brainstem atrophy, which correlates with the formation of intranuclear aggregates in a specific subset of neurons. Several studies have demonstrated that the formation of aggregates depends on the generation of aggregation-prone and toxic intracellular ataxin-3 fragments after proteolytic cleavage of the full-length protein. Despite this observed increase in aggregated mutant ataxin-3, information on soluble mutant ataxin-3 levels in brain tissue is lacking. A quantitative method to analyze soluble levels will be a useful tool to characterize disease progression or to screen and identify therapeutic compounds modulating the level of toxic soluble ataxin-3. In the present study we describe the development and application of a quantitative and easily applicable immunoassay for quantification of soluble mutant ataxin-3 in human cell lines and brain samples of transgenic SCA3 mice. Consistent with observations in Huntington disease, transgenic SCA3 mice reveal a tendency for decrease of soluble mutant ataxin-3 during disease progression in fractions of the cerebellum, which is inversely correlated with aggregate formation and phenotypic aggravation. Our analyses demonstrate that the time-resolved Förster resonance energy transfer immunoassay is a highly sensitive and easy method to measure the level of soluble mutant ataxin-3 in biological samples. Of interest, we observed a tendency for decrease of soluble mutant ataxin-3 only in the cerebellum of transgenic SCA3 mice, one of the most affected brain regions in Spinocerebellar Ataxia Type 3 but not in whole brain tissue, indicative of a brain region selective change in mutant ataxin-3 protein homeostasis.
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Affiliation(s)
- Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Jeannette Hübener
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
- * E-mail:
| | - Jonasz Jeremiasz Weber
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Stephan Grueninger
- Neuroscience Discovery, Novartis Institute for BioMedical Research, Basel, Switzerland
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Andreas Weiss
- Neuroscience Discovery, Novartis Institute for BioMedical Research, Basel, Switzerland
- IRBM Promidis, Pomezia, Italy
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Zhou YF, Liao SS, Luo YY, Tang JG, Wang JL, Lei LF, Chi JW, Du J, Jiang H, Xia K, Tang BS, Shen L. SUMO-1 modification on K166 of polyQ-expanded ataxin-3 strengthens its stability and increases its cytotoxicity. PLoS One 2013; 8:e54214. [PMID: 23382880 PMCID: PMC3561348 DOI: 10.1371/journal.pone.0054214] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Accepted: 12/10/2012] [Indexed: 12/18/2022] Open
Abstract
Post-translational modification by SUMO was proposed to modulate the pathogenesis of several neurodegenerative diseases. Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is an autosomal dominant neurodegenerative disease caused by polyQ-expanded ataxin-3. We have previously shown that ataxin-3 was a new target of SUMOylation in vitro and in vivo. Here we identified that the major SUMO-1 binding site was located on lysine 166. SUMOylation did not influence the subcellular localization, ubiquitination or aggregates formation of mutant-type ataxin-3, but partially increased its stability and the cell apoptosis. Our findings revealed the role of ataxin-3 SUMOylation in SCA3/MJD pathogenesis.
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Affiliation(s)
- Ya-Fang Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Shu-Sheng Liao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Ying-Ying Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jian-Guang Tang
- Department of Neurology, the Second Xiangya Hospital, Central South University, Changsha, China
| | - Jun-Ling Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Li-Fang Lei
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Jing-Wei Chi
- National Laboratory of Medical Genetics of China, Central South University, Changsha, China
| | - Juan Du
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hong Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Laboratory of Medical Genetics of China, Central South University, Changsha, China
| | - Kun Xia
- National Laboratory of Medical Genetics of China, Central South University, Changsha, China
| | - Bei-Sha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Laboratory of Medical Genetics of China, Central South University, Changsha, China
- Neurodegenerative Disorders Research Center, Central South University, Changsha, China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Neurodegenerative Disorders Research Center, Central South University, Changsha, China
- * E-mail:
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Hsp40 gene therapy exerts therapeutic effects on polyglutamine disease mice via a non-cell autonomous mechanism. PLoS One 2012; 7:e51069. [PMID: 23226463 PMCID: PMC3511362 DOI: 10.1371/journal.pone.0051069] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/29/2012] [Indexed: 11/23/2022] Open
Abstract
The polyglutamine (polyQ) diseases such as Huntington’s disease (HD), are neurodegenerative diseases caused by proteins with an expanded polyQ stretch, which misfold and aggregate, and eventually accumulate as inclusion bodies within neurons. Molecules that inhibit polyQ protein misfolding/aggregation, such as Polyglutamine Binding Peptide 1 (QBP1) and molecular chaperones, have been shown to exert therapeutic effects in vivo by crossing of transgenic animals. Towards developing a therapy using these aggregation inhibitors, we here investigated the effect of viral vector-mediated gene therapy using QBP1 and molecular chaperones on polyQ disease model mice. We found that injection of adeno-associated virus type 5 (AAV5) expressing QBP1 or Hsp40 into the striatum both dramatically suppresses inclusion body formation in the HD mouse R6/2. AAV5-Hsp40 injection also ameliorated the motor impairment and extended the lifespan of R6/2 mice. Unexpectedly, we found even in virus non-infected cells that AAV5-Hsp40 appreciably suppresses inclusion body formation, suggesting a non-cell autonomous therapeutic effect. We further show that Hsp40 inhibits secretion of the polyQ protein from cultured cells, implying that it inhibits the recently suggested cell-cell transmission of the polyQ protein. Our results demonstrate for the first time the therapeutic effect of Hsp40 gene therapy on the neurological phenotypes of polyQ disease mice.
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