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Bonsor M, Ammar O, Schnoegl S, Wanker EE, Silva Ramos E. Polyglutamine disease proteins: Commonalities and differences in interaction profiles and pathological effects. Proteomics 2024; 24:e2300114. [PMID: 38615323 DOI: 10.1002/pmic.202300114] [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: 11/30/2023] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/16/2024]
Abstract
Currently, nine polyglutamine (polyQ) expansion diseases are known. They include spinocerebellar ataxias (SCA1, 2, 3, 6, 7, 17), spinal and bulbar muscular atrophy (SBMA), dentatorubral-pallidoluysian atrophy (DRPLA), and Huntington's disease (HD). At the root of these neurodegenerative diseases are trinucleotide repeat mutations in coding regions of different genes, which lead to the production of proteins with elongated polyQ tracts. While the causative proteins differ in structure and molecular mass, the expanded polyQ domains drive pathogenesis in all these diseases. PolyQ tracts mediate the association of proteins leading to the formation of protein complexes involved in gene expression regulation, RNA processing, membrane trafficking, and signal transduction. In this review, we discuss commonalities and differences among the nine polyQ proteins focusing on their structure and function as well as the pathological features of the respective diseases. We present insights from AlphaFold-predicted structural models and discuss the biological roles of polyQ-containing proteins. Lastly, we explore reported protein-protein interaction networks to highlight shared protein interactions and their potential relevance in disease development.
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Affiliation(s)
- Megan Bonsor
- Department of Neuroproteomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Orchid Ammar
- Department of Neuroproteomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Sigrid Schnoegl
- Department of Neuroproteomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Erich E Wanker
- Department of Neuroproteomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Eduardo Silva Ramos
- Department of Neuroproteomics, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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2
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Zhang H, Wu S, Itzhaki LS, Perrett S. Interaction between huntingtin exon 1 and HEAT repeat structure probed by chimeric model proteins. Protein Sci 2023; 32:e4810. [PMID: 37853955 PMCID: PMC10659953 DOI: 10.1002/pro.4810] [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: 06/29/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 10/20/2023]
Abstract
Huntington disease (HD) is associated with aggregation of huntingtin (HTT) protein containing over 35 continuous Q residues within the N-terminal exon 1 encoded region. The C-terminal of the HTT protein consists mainly of HEAT repeat structure which serves as a scaffold for multiple cellular activities. Structural and biochemical analysis of the intact HTT protein has been hampered by its huge size (~300 kDa) and most in vitro studies to date have focused on the properties of the exon 1 region. To explore the interaction between HTT exon 1 and the HEAT repeat structure, we constructed chimeric proteins containing the N-terminal HTT exon 1 region and the HEAT repeat protein PR65/A. The results indicate that HTT exon 1 slightly destabilizes the downstream HEAT repeat structure and endows the HEAT repeat structure with more conformational flexibility. Wild-type and pathological lengths of polyQ did not show differences in the interaction between HTT exon 1 and the HEAT repeats. With the C-terminal fusion of PR65/A, HTT exon 1 containing pathological lengths of polyQ could still form amyloid fibrils, but the higher-order architecture of fibrils and kinetics of fibril formation were affected by the C-terminal fusion of HEAT repeats. This indicates that interaction between HTT exon 1 and HEAT repeat structure is compatible with both normal function of HTT protein and the pathogenesis of HD, and this study provides a potential model for further exploration.
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Affiliation(s)
- Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
- Institute of Basic Medical Sciences, Chinese Academy of Medical SciencesPeking Union Medical CollegeBeijingChina
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
| | | | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
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3
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Reed AL, Mitchell W, Alexandrescu AT, Alder NN. Interactions of amyloidogenic proteins with mitochondrial protein import machinery in aging-related neurodegenerative diseases. Front Physiol 2023; 14:1263420. [PMID: 38028797 PMCID: PMC10652799 DOI: 10.3389/fphys.2023.1263420] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023] Open
Abstract
Most mitochondrial proteins are targeted to the organelle by N-terminal mitochondrial targeting sequences (MTSs, or "presequences") that are recognized by the import machinery and subsequently cleaved to yield the mature protein. MTSs do not have conserved amino acid compositions, but share common physicochemical properties, including the ability to form amphipathic α-helical structures enriched with basic and hydrophobic residues on alternating faces. The lack of strict sequence conservation implies that some polypeptides can be mistargeted to mitochondria, especially under cellular stress. The pathogenic accumulation of proteins within mitochondria is implicated in many aging-related neurodegenerative diseases, including Alzheimer's, Parkinson's, and Huntington's diseases. Mechanistically, these diseases may originate in part from mitochondrial interactions with amyloid-β precursor protein (APP) or its cleavage product amyloid-β (Aβ), α-synuclein (α-syn), and mutant forms of huntingtin (mHtt), respectively, that are mediated in part through their associations with the mitochondrial protein import machinery. Emerging evidence suggests that these amyloidogenic proteins may present cryptic targeting signals that act as MTS mimetics and can be recognized by mitochondrial import receptors and transported into different mitochondrial compartments. Accumulation of these mistargeted proteins could overwhelm the import machinery and its associated quality control mechanisms, thereby contributing to neurological disease progression. Alternatively, the uptake of amyloidogenic proteins into mitochondria may be part of a protein quality control mechanism for clearance of cytotoxic proteins. Here we review the pathomechanisms of these diseases as they relate to mitochondrial protein import and effects on mitochondrial function, what features of APP/Aβ, α-syn and mHtt make them suitable substrates for the import machinery, and how this information can be leveraged for the development of therapeutic interventions.
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Affiliation(s)
- Ashley L. Reed
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Wayne Mitchell
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Andrei T. Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Nathan N. Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
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4
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Sahoo G, Samal D, Khandayataray P, Murthy MK. A Review on Caspases: Key Regulators of Biological Activities and Apoptosis. Mol Neurobiol 2023; 60:5805-5837. [PMID: 37349620 DOI: 10.1007/s12035-023-03433-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Caspases are proteolytic enzymes that belong to the cysteine protease family and play a crucial role in homeostasis and programmed cell death. Caspases have been broadly classified by their known roles in apoptosis (caspase-3, caspase-6, caspase-7, caspase-8, and caspase-9 in mammals) and in inflammation (caspase-1, caspase-4, caspase-5, and caspase-12 in humans, and caspase-1, caspase-11, and caspase-12 in mice). Caspases involved in apoptosis have been subclassified by their mechanism of action as either initiator caspases (caspase-8 and caspase-9) or executioner caspases (caspase-3, caspase-6, and caspase-7). Caspases that participate in apoptosis are inhibited by proteins known as inhibitors of apoptosis (IAPs). In addition to apoptosis, caspases play a role in necroptosis, pyroptosis, and autophagy, which are non-apoptotic cell death processes. Dysregulation of caspases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders, and increasing evidence shows that altering caspase activity can confer therapeutic benefits. This review covers the different types of caspases, their functions, and their physiological and biological activities and roles in different organisms.
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Affiliation(s)
- Gayatri Sahoo
- Department of Zoology, PSSJ College, Banarpal, 759128, Odisha, India
| | - Dibyaranjan Samal
- Department of Biotechnology, Academy of Management and Information Technology (AMIT, affiliated to Utkal University), Khurda, 752057, Odisha, India
| | | | - Meesala Krishna Murthy
- Department of Allied Health Sciences, Chitkara School of Health Sciences, Chitkara University, Rajpura, Punjab, 140401, India.
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5
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Bhat SA, Ahamad S, Dar NJ, Siddique YH, Nazir A. The Emerging Landscape of Natural Small-molecule Therapeutics for Huntington's Disease. Curr Neuropharmacol 2023; 21:867-889. [PMID: 36797612 PMCID: PMC10227909 DOI: 10.2174/1570159x21666230216104621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/12/2022] [Accepted: 11/18/2022] [Indexed: 02/18/2023] Open
Abstract
Huntington's disease (HD) is a rare and fatal neurodegenerative disorder with no diseasemodifying therapeutics. HD is characterized by extensive neuronal loss and is caused by the inherited expansion of the huntingtin (HTT) gene that encodes a toxic mutant HTT (mHTT) protein having expanded polyglutamine (polyQ) residues. Current HD therapeutics only offer symptomatic relief. In fact, Food and Drug Administration (FDA) approved two synthetic small-molecule VMAT2 inhibitors, tetrabenazine (1) and deutetrabenazine (2), for managing HD chorea and various other diseases in clinical trials. Therefore, the landscape of drug discovery programs for HD is evolving to discover disease- modifying HD therapeutics. Likewise, numerous natural products are being evaluated at different stages of clinical development and have shown the potential to ameliorate HD pathology. The inherent anti-inflammatory and antioxidant properties of natural products mitigate the mHTT-induced oxidative stress and neuroinflammation, improve mitochondrial functions, and augment the anti-apoptotic and pro-autophagic mechanisms for increased survival of neurons in HD. In this review, we have discussed HD pathogenesis and summarized the anti-HD clinical and pre-clinical natural products, focusing on their therapeutic effects and neuroprotective mechanism/s.
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Affiliation(s)
| | - Shakir Ahamad
- Department of Chemistry, Aligarh Muslim University, Aligarh, U.P., India
| | - Nawab John Dar
- School of Medicine, UT Health San Antonio, Texas, TX, USA
| | | | - Aamir Nazir
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, U.P., India
- Academy of Scientific and Innovative Research, New Delhi, India
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6
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Saha G, Ghosh S, Dubey VK, Saudagar P. Gene Alterations Induced by Glutamine (Q) Encoding CAG Repeats Associated with Neurodegeneration. Methods Mol Biol 2023; 2575:3-23. [PMID: 36301468 DOI: 10.1007/978-1-0716-2716-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Several studies have been reported linking the role of polyglutamine (polyQ) disease-associated proteins with altered gene regulation induced by an unstable trinucleotide (CAG) repeat. Owing to their dynamic nature of expansion, these DNA repeats form secondary structures interfering with the normal cellular mechanisms like replication and transcription and, thereby, have become the underlying cause of numerous neurodegenerative disorders involving mental retardation and/or muscular or neuronal degeneration. Despite the widespread expression of the disease-causing protein, specific subsets of neurons are susceptible to specific patterns of inheritance and clinical symptoms. Although this cell-type selectivity is still elusive and less understood, it has been found that aberrant transcriptional regulation is one of the primary causes of polyQ diseases where the functions of histone-modifying complexes are disrupted. Besides, epigenetic modifications play a critical role in the pathogenesis of these diseases. In this chapter, we will be delving into how these polyQ repeats induce the self-assembly and aggregation of altered carrier proteins based on gene alterations, causing neuronal toxicity and cellular deaths. Besides, genomic instability in CAG repeats due to altered chromatin-related enzymes will be highlighted, along with epigenetic changes present in many polyQ disorders. Understanding the underlying molecular mechanisms in the root cause of these disorders will culminate in identifying therapeutic approaches for the treatment of these neurodegenerative disorders.
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Affiliation(s)
- Gundappa Saha
- Department of Basic & Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sukanya Ghosh
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Vikash Kumar Dubey
- School of Biochemical Engineering, Indian Institute of Technology BHU, Varanasi, Uttar Pradesh, India
| | - Prakash Saudagar
- Department of Biotechnology, National Institute of Technology, Warangal, Telangana, India.
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Incebacak Eltemur RD, Nguyen HP, Weber JJ. Calpain-mediated proteolysis as driver and modulator of polyglutamine toxicity. Front Mol Neurosci 2022; 15:1020104. [PMID: 36385755 PMCID: PMC9648470 DOI: 10.3389/fnmol.2022.1020104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/26/2022] [Indexed: 09/22/2023] Open
Abstract
Among posttranslational modifications, directed proteolytic processes have the strongest impact on protein integrity. They are executed by a variety of cellular machineries and lead to a wide range of molecular consequences. Compared to other forms of proteolytic enzymes, the class of calcium-activated calpains is considered as modulator proteases due to their limited proteolytic activity, which changes the structure and function of their target substrates. In the context of neurodegeneration and - in particular - polyglutamine disorders, proteolytic events have been linked to modulatory effects on the molecular pathogenesis by generating harmful breakdown products of disease proteins. These findings led to the formulation of the toxic fragment hypothesis, and calpains appeared to be one of the key players and auspicious therapeutic targets in Huntington disease and Machado Joseph disease. This review provides a current survey of the role of calpains in proteolytic processes found in polyglutamine disorders. Together with insights into general concepts behind toxic fragments and findings in polyglutamine disorders, this work aims to inspire researchers to broaden and deepen the knowledge in this field, which will help to evaluate calpain-mediated proteolysis as a unifying and therapeutically targetable posttranslational mechanism in neurodegeneration.
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Affiliation(s)
- Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
| | - Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Bochum, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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8
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Baier A, Szyszka R. CK2 and protein kinases of the CK1 superfamily as targets for neurodegenerative disorders. Front Mol Biosci 2022; 9:916063. [PMID: 36275622 PMCID: PMC9582958 DOI: 10.3389/fmolb.2022.916063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/02/2022] [Indexed: 11/13/2022] Open
Abstract
Casein kinases are involved in a variety of signaling pathways, and also in inflammation, cancer, and neurological diseases. Therefore, they are regarded as potential therapeutic targets for drug design. Recent studies have highlighted the importance of the casein kinase 1 superfamily as well as protein kinase CK2 in the development of several neurodegenerative pathologies, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. CK1 kinases and their closely related tau tubulin kinases as well as CK2 are found to be overexpressed in the mammalian brain. Numerous substrates have been detected which play crucial roles in neuronal and synaptic network functions and activities. The development of new substances for the treatment of these pathologies is in high demand. The impact of these kinases in the progress of neurodegenerative disorders, their bona fide substrates, and numerous natural and synthetic compounds which are able to inhibit CK1, TTBK, and CK2 are discussed in this review.
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Affiliation(s)
- Andrea Baier
- Institute of Biological Sciences, The John Paul II Catholic University of Lublin, Lublin, Poland
| | - Ryszard Szyszka
- Institute of Biological Sciences, The John Paul II Catholic University of Lublin, Lublin, Poland
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9
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van der Bent ML, Evers MM, Vallès A. Emerging Therapies for Huntington's Disease - Focus on N-Terminal Huntingtin and Huntingtin Exon 1. Biologics 2022; 16:141-160. [PMID: 36213816 PMCID: PMC9532260 DOI: 10.2147/btt.s270657] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 09/14/2022] [Indexed: 11/12/2022]
Abstract
Huntington's disease is a devastating heritable neurodegenerative disorder that is caused by the presence of a trinucleotide CAG repeat expansion in the Huntingtin gene, leading to a polyglutamine tract in the protein. Various mechanisms lead to the production of N-terminal Huntingtin protein fragments, which are reportedly more toxic than the full-length protein. In this review, we summarize the current knowledge on the production and toxicity of N-terminal Huntingtin protein fragments. Further, we expand on various therapeutic strategies targeting N-terminal Huntingtin on the protein, RNA and DNA level. Finally, we compare the therapeutic approaches that are clinically most advanced, including those that do not target N-terminal Huntingtin, discussing differences in mode of action and translational applicability.
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Affiliation(s)
| | - Melvin M Evers
- uniQure biopharma B.V., Department of Research and Development, Amsterdam, the Netherlands
| | - Astrid Vallès
- uniQure biopharma B.V., Department of Research and Development, Amsterdam, the Netherlands
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10
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Johnson SL, Tsou WL, Prifti MV, Harris AL, Todi SV. A survey of protein interactions and posttranslational modifications that influence the polyglutamine diseases. Front Mol Neurosci 2022; 15:974167. [PMID: 36187346 PMCID: PMC9515312 DOI: 10.3389/fnmol.2022.974167] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/27/2022] [Indexed: 01/20/2023] Open
Abstract
The presence and aggregation of misfolded proteins has deleterious effects in the nervous system. Among the various diseases caused by misfolded proteins is the family of the polyglutamine (polyQ) disorders. This family comprises nine members, all stemming from the same mutation—the abnormal elongation of a polyQ repeat in nine different proteins—which causes protein misfolding and aggregation, cellular dysfunction and disease. While it is the same type of mutation that causes them, each disease is distinct: it is influenced by regions and domains that surround the polyQ repeat; by proteins with which they interact; and by posttranslational modifications they receive. Here, we overview the role of non-polyQ regions that control the pathogenicity of the expanded polyQ repeat. We begin by introducing each polyQ disease, the genes affected, and the symptoms experienced by patients. Subsequently, we provide a survey of protein-protein interactions and posttranslational modifications that regulate polyQ toxicity. We conclude by discussing shared processes and pathways that bring some of the polyQ diseases together and may serve as common therapeutic entry points for this family of incurable disorders.
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Affiliation(s)
- Sean L. Johnson
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Wei-Ling Tsou
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Matthew V. Prifti
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Autumn L. Harris
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
- Maximizing Access to Research Careers (MARC) Program, Wayne State University, Detroit, MI, United States
| | - Sokol V. Todi
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
- Maximizing Access to Research Careers (MARC) Program, Wayne State University, Detroit, MI, United States
- Department of Neurology, Wayne State University, Detroit, MI, United States
- *Correspondence: Sokol V. Todi,
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11
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Cho IK, Clever F, Hong G, Chan AWS. CAG Repeat Instability in the Peripheral and Central Nervous System of Transgenic Huntington’s Disease Monkeys. Biomedicines 2022; 10:biomedicines10081863. [PMID: 36009409 PMCID: PMC9405741 DOI: 10.3390/biomedicines10081863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/16/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022] Open
Abstract
Huntington’s Disease (HD) is an autosomal dominant disease that results in severe neurodegeneration with no cure. HD is caused by the expanded CAG trinucleotide repeat (TNR) on the Huntingtin gene (HTT). Although the somatic and germline expansion of the CAG repeats has been well-documented, the underlying mechanisms had not been fully delineated. Increased CAG repeat length is associated with a more severe phenotype, greater TNR instability, and earlier age of onset. The direct relationship between CAG repeat length and molecular pathogenesis makes TNR instability a useful measure of symptom severity and tissue susceptibility. Thus, we examined the tissue-specific TNR instability of transgenic nonhuman primate models of Huntington’s disease. Our data show a similar profile of CAG repeat expansion in both rHD1 and rHD7, where high instability was observed in testis, liver, caudate, and putamen. CAG repeat expansion was observed in all tissue samples, and tissue- and CAG repeat size-dependent expansion was observed. Correlation analysis of CAG repeat expansion and the gene expression profile of four genes in different tissues, clusterin (CLU), transferrin (TF), ribosomal protein lateral stalk subunit P1 (RPLP1), and ribosomal protein L13a (RPL13A), showed a strong correlation with CAG repeat instability. Overall, our data, along with previously published studies, can be used for studying the biology of CAG repeat instability and identifying new therapeutic targets.
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Affiliation(s)
- In K. Cho
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA;
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (F.C.); (G.H.)
- Correspondence:
| | - Faye Clever
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (F.C.); (G.H.)
| | - Gordon Hong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (F.C.); (G.H.)
| | - Anthony W. S. Chan
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA;
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA; (F.C.); (G.H.)
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12
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Moretto E, Stuart S, Surana S, Vargas JNS, Schiavo G. The Role of Extracellular Matrix Components in the Spreading of Pathological Protein Aggregates. Front Cell Neurosci 2022; 16:844211. [PMID: 35573838 PMCID: PMC9100790 DOI: 10.3389/fncel.2022.844211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/08/2022] [Indexed: 11/23/2022] Open
Abstract
Several neurodegenerative diseases are characterized by the accumulation of aggregated misfolded proteins. These pathological agents have been suggested to propagate in the brain via mechanisms similar to that observed for the prion protein, where a misfolded variant is transferred from an affected brain region to a healthy one, thereby inducing the misfolding and/or aggregation of correctly folded copies. This process has been characterized for several proteins, such as α-synuclein, tau, amyloid beta (Aβ) and less extensively for huntingtin and TDP-43. α-synuclein, tau, TDP-43 and huntingtin are intracellular proteins, and their aggregates are located in the cytosol or nucleus of neurons. They have been shown to spread between cells and this event occurs, at least partially, via secretion of these protein aggregates in the extracellular space followed by re-uptake. Conversely, Aβ aggregates are found mainly extracellularly, and their spreading occurs in the extracellular space between brain regions. Due to the inherent nature of their spreading modalities, these proteins are exposed to components of the extracellular matrix (ECM), including glycans, proteases and core matrix proteins. These ECM components can interact with or process pathological misfolded proteins, potentially changing their properties and thus regulating their spreading capabilities. Here, we present an overview of the documented roles of ECM components in the spreading of pathological protein aggregates in neurodegenerative diseases with the objective of identifying the current gaps in knowledge and stimulating further research in the field. This could potentially lead to the identification of druggable targets to slow down the spreading and/or progression of these pathologies.
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Affiliation(s)
- Edoardo Moretto
- Institute of Neuroscience, National Research Council, CNR, Milan, Italy
- UK Dementia Research Institute, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
- *Correspondence: Edoardo Moretto,
| | - Skye Stuart
- UK Dementia Research Institute, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Sunaina Surana
- UK Dementia Research Institute, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
- UCL Queen Square Motor Neuron Disease Centre, University College London, London, United Kingdom
| | - Jose Norberto S. Vargas
- UK Dementia Research Institute, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
- UCL Queen Square Motor Neuron Disease Centre, University College London, London, United Kingdom
| | - Giampietro Schiavo
- UK Dementia Research Institute, University College London, London, United Kingdom
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, London, United Kingdom
- UCL Queen Square Motor Neuron Disease Centre, University College London, London, United Kingdom
- Giampietro Schiavo,
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N-alpha-acetylation of Huntingtin protein increases its propensity to aggregate. J Biol Chem 2021; 297:101363. [PMID: 34732320 PMCID: PMC8640455 DOI: 10.1016/j.jbc.2021.101363] [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: 09/07/2021] [Revised: 10/23/2021] [Accepted: 10/25/2021] [Indexed: 11/22/2022] Open
Abstract
Huntington’s disease (HD) is a neurodegenerative disorder caused by a poly-CAG expansion in the first exon of the HTT gene, resulting in an extended poly-glutamine tract in the N-terminal domain of the Huntingtin (Htt) protein product. Proteolytic fragments of the poly-glutamine–containing N-terminal domain form intranuclear aggregates that are correlated with HD. Post-translational modification of Htt has been shown to alter its function and aggregation properties. However, the effect of N-terminal Htt acetylation has not yet been considered. Here, we developed a bacterial system to produce unmodified or N-terminally acetylated and aggregation-inducible Htt protein. We used this system together with biochemical, biophysical, and imaging studies to confirm that the Htt N-terminus is an in vitro substrate for the NatA N-terminal acetyltransferase and show that N-terminal acetylation promotes aggregation. These studies represent the first link between N-terminal acetylation and the promotion of a neurodegenerative disease and implicates NatA-mediated Htt acetylation as a new potential therapeutic target in HD.
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14
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Chongtham A, Bornemann DJ, Barbaro BA, Lukacsovich T, Agrawal N, Syed A, Worthge S, Purcell J, Burke J, Chin TM, Marsh JL. Effects of flanking sequences and cellular context on subcellular behavior and pathology of mutant HTT. Hum Mol Genet 2021; 29:674-688. [PMID: 31943010 DOI: 10.1093/hmg/ddaa001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/06/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022] Open
Abstract
Huntington's disease (HD) is caused by an expansion of a poly glutamine (polyQ) stretch in the huntingtin protein (HTT) that is necessary to cause pathology and formation of HTT aggregates. Here we ask whether expanded polyQ is sufficient to cause pathology and aggregate formation. By addressing the sufficiency question, one can identify cellular processes and structural parameters that influence HD pathology and HTT subcellular behavior (i.e. aggregation state and subcellular location). Using Drosophila, we compare the effects of expressing mutant full-length human HTT (fl-mHTT) to the effects of mutant human HTTexon1 and to two commonly used synthetic fragments, HTT171 and shortstop (HTT118). Expanded polyQ alone is not sufficient to cause inclusion formation since full-length HTT and HTTex1 with expanded polyQ are both toxic although full-length HTT remains diffuse while HTTex1 forms inclusions. Further, inclusions are not sufficient to cause pathology since HTT171-120Q forms inclusions but is benign and co-expression of HTT171-120Q with non-aggregating pathogenic fl-mHTT recruits fl-mHTT to aggregates and rescues its pathogenicity. Additionally, the influence of sequences outside the expanded polyQ domain is revealed by finding that small modifications to the HTT118 or HTT171 fragments can dramatically alter their subcellular behavior and pathogenicity. Finally, mutant HTT subcellular behavior is strongly modified by different cell and tissue environments (e.g. fl-mHTT appears as diffuse nuclear in one tissue and diffuse cytoplasmic in another but toxic in both). These observations underscore the importance of cellular and structural context for the interpretation and comparison of experiments using different fragments and tissues to report the effects of expanded polyQ.
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Affiliation(s)
- Anjalika Chongtham
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - Douglas J Bornemann
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Brett A Barbaro
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Tamas Lukacsovich
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Namita Agrawal
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Adeela Syed
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Shane Worthge
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Judith Purcell
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - John Burke
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Theodore M Chin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
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15
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Inhibition of GSK-3 ameliorates the pathogenesis of Huntington's disease. Neurobiol Dis 2021; 154:105336. [PMID: 33753290 DOI: 10.1016/j.nbd.2021.105336] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/10/2021] [Accepted: 03/17/2021] [Indexed: 12/22/2022] Open
Abstract
In Huntington's disease (HD), the mutant huntingtin (mHtt) accumulates as toxic aggregates in the striatum tissue, with deleterious effects on motor-coordination and cognitive functions. Reducing the levels of mHtt is therefore a promising therapeutic strategy. We have previously reported that GSK-3 is a negative regulator of the autophagy/lysosome pathway, which is responsible for intracellular degradation, and is critically important for maintaining neuronal vitality. Thus, we hypothesized that inhibition of GSK-3 may trigger mHtt clearance thereby reducing mHtt cytotoxicity and improving HD symptoms. Here, we demonstrate that depletion or suppression of autophagy results in a massive accumulation of mHtt aggregates. Accordingly, mHtt aggregates were localized in lysosomes, but, mostly mislocalized from lysosomes in the absence of functional autophagy. Overexpression of GSK-3, particularly the α isozyme, increased the number of mHtt aggregates, while silencing GSK-3α/β, or treatment with a selective GSK-3 inhibitor, L807mts, previously described by us, reduced the amounts of mHtt aggregates. This effect was mediated by increased autophagic and lysosomal activity. Treating R6/2 mouse model of HD with L807mts, reduced striatal mHtt aggregates and elevated autophagic and lysosomal markers. The L807mts treatment also reduced hyperglycemia and improved motor-coordination functions in these mice. In addition, L807mts restored the expression levels of Sirt1, a critical neuroprotective factor in the HD striatum, along with its targets BDNF, DRPP-32, and active Akt, all provide neurotrophic/pro-survival support and typically decline in the HD brain. Our results provide strong evidence for a role for GSK-3 in the regulation of mHtt dynamics, and demonstrate the benefits of GSK-3 inhibition in reducing mHtt toxicity, providing neuroprotective support, and improving HD symptoms.
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16
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Tu Y, Li X, Zhu X, Liu X, Guo C, Jia D, Tang TS. Determining the Fate of Neurons in SCA3: ATX3, a Rising Decision Maker in Response to DNA Stresses and Beyond. Front Cell Dev Biol 2021; 8:619911. [PMID: 33425926 PMCID: PMC7793700 DOI: 10.3389/fcell.2020.619911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/01/2020] [Indexed: 12/14/2022] Open
Abstract
DNA damage response (DDR) and apoptosis are reported to be involved in the pathogenesis of many neurodegenerative diseases including polyglutamine (polyQ) disorders, such as Spinocerebellar ataxia type 3 (SCA3) and Huntington's disease (HD). Consistently, an increasing body of studies provide compelling evidence for the crucial roles of ATX3, whose polyQ expansion is defined as the cause of SCA3, in the maintenance of genome integrity and regulation of apoptosis. The polyQ expansion in ATX3 seems to affect its physiological functions in these distinct pathways. These advances have expanded our understanding of the relationship between ATX3's cellular functions and the underlying molecular mechanism of SCA3. Interestingly, dysregulated DDR pathways also contribute to the pathogenesis of other neurodegenerative disorder such as HD, which presents a common molecular mechanism yet distinct in detail among different diseases. In this review, we provide a comprehensive overview of the current studies about the physiological roles of ATX3 in DDR and related apoptosis, highlighting the crosslinks between these impaired pathways and the pathogenesis of SCA3. Moreover, whether these mechanisms are shared in other neurodegenerative diseases are analyzed. Finally, the preclinical studies targeting DDR and related apoptosis for treatment of polyQ disorders including SCA3 and HD are also summarized and discussed.
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Affiliation(s)
- Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Xiaoling Li
- Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, China
| | - Xuefei Zhu
- Guangdong Key Laboratory for Genome Stability & Disease Prevention, Shenzhen University Health Science Center, Shenzhen, China
| | - Xiaokang Liu
- Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, China
| | - Caixia Guo
- Beijing Institute of Genomics (China National Center for Bioinformation), University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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17
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Neueder A, Orth M. Mitochondrial biology and the identification of biomarkers of Huntington's disease. Neurodegener Dis Manag 2020; 10:243-255. [PMID: 32746707 DOI: 10.2217/nmt-2019-0033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Apart from finding novel compounds for treating Huntington's disease (HD) an important challenge at present consists in finding reliable read-outs or biomarkers that reflect key biological processes involved in HD pathogenesis. The core elements of HD biology, for example, HTT RNA levels or protein species can serve as biomarker, as could measures from biological systems or pathways in which Huntingtin plays an important role. Here we review the evidence for the involvement of mitochondrial biology in HD. The most consistent findings pertain to mitochondrial quality control, for example, fission/fusion. However, a convincing mitochondrial signature with biomarker potential is yet to emerge. This requires more research including in peripheral sources of human material, such as blood, or skeletal muscle.
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Affiliation(s)
| | - Michael Orth
- Department of Neurology, Ulm University, Ulm, Germany.,SwissHuntington's Disease Centre, Neurozentrum Siloah, Worbstr. 312, 3073 Gümligenbei Bern, Switzerland
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18
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Bartl S, Oueslati A, Southwell AL, Siddu A, Parth M, David LS, Maxan A, Salhat N, Burkert M, Mairhofer A, Friedrich T, Pankevych H, Balazs K, Staffler G, Hayden MR, Cicchetti F, Smrzka OW. Inhibiting cellular uptake of mutant huntingtin using a monoclonal antibody: Implications for the treatment of Huntington's disease. Neurobiol Dis 2020; 141:104943. [PMID: 32407769 DOI: 10.1016/j.nbd.2020.104943] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/08/2020] [Accepted: 05/06/2020] [Indexed: 12/24/2022] Open
Abstract
Huntington's disease (HD) is caused by a highly polymorphic CAG trinucleotide expansion in the gene encoding for the huntingtin protein (HTT). The resulting mutant huntingtin protein (mutHTT) is ubiquitously expressed but also exhibits the ability to propagate from cell-to-cell to disseminate pathology; a property which may serve as a new therapeutic focus. Accordingly, we set out to develop a monoclonal antibody (mAB) targeting a particularly exposed region close to the aa586 caspase-6 cleavage site of the HTT protein. This monoclonal antibody, designated C6-17, effectively binds mutHTT and is able to deplete the protein from cell culture supernatants. Using cell-based assays, we demonstrate that extracellular secretion of mutHTT into cell culture media and its subsequent uptake in recipient HeLa cells can be almost entirely blocked by mAB C6-17. Immunohistochemical stainings of post-mortem HD brain tissue confirmed the specificity of mAB C6-17 to human mutHTT aggregates. These findings demonstrate that mAB C6-17 not only successfully engages with its target, mutHTT, but also inhibits cell uptake suggesting that this antibody could interfere with the pathological processes of mutHTT spreading in vivo.
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Affiliation(s)
| | - Abid Oueslati
- Université Laval/Centre de recherche du CHU, Québec, Canada
| | | | - Alberto Siddu
- Université Laval/Centre de recherche du CHU, Québec, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | - Oskar W Smrzka
- AFFiRiS AG, Vienna, Austria; Ablevia biotech GmbH, Vienna, Austria
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19
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Park J, Lai MKP, Arumugam TV, Jo DG. O-GlcNAcylation as a Therapeutic Target for Alzheimer's Disease. Neuromolecular Med 2020; 22:171-193. [PMID: 31894464 DOI: 10.1007/s12017-019-08584-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and the number of elderly patients suffering from AD has been steadily increasing. Despite worldwide efforts to cope with this disease, little progress has been achieved with regard to identification of effective therapeutics. Thus, active research focusing on identification of new therapeutic targets of AD is ongoing. Among the new targets, post-translational modifications which modify the properties of mature proteins have gained attention. O-GlcNAcylation, a type of PTM that attaches O-linked β-N-acetylglucosamine (O-GlcNAc) to a protein, is being sought as a new target to treat AD pathologies. O-GlcNAcylation has been known to modify the two important components of AD pathological hallmarks, amyloid precursor protein, and tau protein. In addition, elevating O-GlcNAcylation levels in AD animal models has been shown to be effective in alleviating AD-associated pathology. Although studies investigating the precise mechanism of reversal of AD pathologies by targeting O-GlcNAcylation are not yet complete, it is clearly important to examine O-GlcNAcylation regulation as a target of AD therapeutics. This review highlights the mechanisms of O-GlcNAcylation and its role as a potential therapeutic target under physiological and pathological AD conditions.
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Affiliation(s)
- Jinsu Park
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
- Department of Health Science and Technology, Sungkyunkwan University, Seoul, 06351, Korea
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Thiruma V Arumugam
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea.
- Department of Physiology, Yong Loo Lin School Medicine, National University of Singapore, Singapore, 117593, Singapore.
- Department of Physiology, Anatomy & Microbiology, School of Life Sciences, La Trobe University, Bundoora, VIC, Australia.
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea.
- Department of Health Science and Technology, Sungkyunkwan University, Seoul, 06351, Korea.
- Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, 16419, Korea.
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20
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Smatlikova P, Askeland G, Vaskovicova M, Klima J, Motlik J, Eide L, Ellederová Z. Age-Related Oxidative Changes in Primary Porcine Fibroblasts Expressing Mutated Huntingtin. NEURODEGENER DIS 2019; 19:22-34. [PMID: 31167196 DOI: 10.1159/000500091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 03/30/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is a devastating neurodegenerative disorder caused by CAG triplet expansions in the huntingtin gene. Oxidative stress is linked to HD pathology, although it is not clear whether this is an effect or a mediator of disease. The transgenic (TgHD) minipig expresses the N-terminal part of human-mutated huntingtin and represents a unique model to investigate therapeutic strategies towards HD. A more detailed characterization of this model is needed to fully utilize its potential. METHODS In this study, we focused on the molecular and cellular features of fibroblasts isolated from TgHD minipigs and the wild-type (WT) siblings at different ages, pre-symptomatic at the age of 24-36 months and with the onset of behavioural symptoms at the age of 48 months. We measured oxidative stress, the expression of oxidative stress-related genes, proliferation capacity along with the expression of cyclin B1 and D1 proteins, cellular permeability, and the integrity of the nuclear DNA (nDNA) and mitochondrial DNA in these cells. RESULTS TgHD fibroblasts isolated from 48-month-old animals showed increased oxidative stress, which correlated with the overexpression of SOD2 encoding mitochondrial superoxide dismutase 2, and the NEIL3 gene encoding DNA glycosylase involved in replication-associated repair of oxidized DNA. TgHD cells displayed an abnormal proliferation capacity and permeability. We further demonstrated increased nDNA damage in pre-symptomatic TgHD fibroblasts (isolated from animals aged 24-36 months). CONCLUSIONS Our results unravel phenotypic alterations in primary fibroblasts isolated from the TgHD minipig model at the age of 48 months. Importantly, nDNA damage appears to precede these phenotypic alterations. Our results highlight the impact of fibroblasts from TgHD minipigs in studying the molecular mechanisms of HD pathophysiology that gradually occur with age.
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Affiliation(s)
- Petra Smatlikova
- Laboratory of Cell Regeneration and Plasticity, Research Center PIGMOD, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czechia.,Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czechia
| | - Georgina Askeland
- Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, Oslo, Norway.,Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | - Michaela Vaskovicova
- Laboratory of DNA Integrity, Research Center PIGMOD, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czechia.,Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czechia
| | - Jiri Klima
- Laboratory of Cell Regeneration and Plasticity, Research Center PIGMOD, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czechia
| | - Jan Motlik
- Laboratory of Cell Regeneration and Plasticity, Research Center PIGMOD, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czechia
| | - Lars Eide
- Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Zdenka Ellederová
- Laboratory of Cell Regeneration and Plasticity, Research Center PIGMOD, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czechia,
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21
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Reindl W, Baldo B, Schulz J, Janack I, Lindner I, Kleinschmidt M, Sedaghat Y, Thiede C, Tillack K, Schmidt C, Cardaun I, Schwagarus T, Herrmann F, Hotze M, Osborne GF, Herrmann S, Weiss A, Zerbinatti C, Bates GP, Bard J, Munoz-Sanjuan I, Macdonald D. Meso scale discovery-based assays for the detection of aggregated huntingtin. PLoS One 2019; 14:e0213521. [PMID: 30913220 PMCID: PMC6435127 DOI: 10.1371/journal.pone.0213521] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/24/2019] [Indexed: 12/31/2022] Open
Abstract
Huntington's disease (HD) is a monogenic neurodegenerative disorder caused by an expansion of the CAG trinucleotide repeat domain in the huntingtin (HTT) gene, leading to an expanded poly-glutamine (polyQ) stretch in the HTT protein. This mutant HTT (mHTT) protein is highly prone to intracellular aggregation, causing significant damage and cellular loss in the striatal, cortical, and other regions of the brain. Therefore, modulation of mHTT levels in these brain regions in order to reduce intracellular mHTT and aggregate levels represents a direct approach in the development of HD therapeutics. To this end, assays that can be used to detect changes in HTT levels in biological samples are invaluable tools to assess target engagement and guide dose selection in clinical trials. The Meso Scale Discovery (MSD) ELISA-based assay platform is a robust and sensitive method previously employed for the quantification of HTT. However, the currently available MSD assays for HTT are primarily detecting the monomeric soluble form of the protein, but not aggregated species. In this study, we describe the development of novel MSD assays preferentially detecting mHTT in an aggregated form. Recombinant monomeric HTT(1-97)-Q46, which forms aggregates in a time-dependent manner, was used to characterize the ability of each established assay to distinguish between HTT monomers and HTT in a higher assembly state. Further validation of these assays was performed using brain lysates from R6/2, zQ175 knock-in, and BACHD mouse models, to replicate a previously well-characterized age-dependent increase in brain aggregate signals, as well as a significant reduction of aggregate levels in the striatum following mHTT knockdown with a CAG-directed allele-specific zinc-finger repressor protein (ZFP). Lastly, size exclusion chromatography was used to separate and characterize HTT species from brain tissue lysates to demonstrate specificity of the assays for the fractions containing aggregated HTT. In summary, we demonstrate that the newly developed assays preferentially detect aggregated HTT with improved performance in comparison to previous assay technologies. These assays complement the existing MSD platform assays specific for soluble HTT monomers, allowing for a more comprehensive analysis of disease-relevant HTT species in preclinical models of HD.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Georgina F. Osborne
- Dept. Neurodegenerative Disease, Huntington’s Disease Centre and Dementia Research Institute, Institute of Neurology, University College London, London, United Kingdom
| | | | | | | | - Gillian P. Bates
- Dept. Neurodegenerative Disease, Huntington’s Disease Centre and Dementia Research Institute, Institute of Neurology, University College London, London, United Kingdom
| | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
| | | | - Douglas Macdonald
- CHDI Management/CHDI Foundation, Los Angeles, CA, United States of America
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22
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Hansen CV, Schroll HJ, Wüstner D. A discontinuous Galerkin model for fluorescence loss in photobleaching of intracellular polyglutamine protein aggregates. BMC BIOPHYSICS 2018; 11:7. [PMID: 30519460 PMCID: PMC6264036 DOI: 10.1186/s13628-018-0046-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 10/30/2018] [Indexed: 12/03/2022]
Abstract
Background Intracellular phase separation and aggregation of proteins with extended poly-glutamine (polyQ) stretches are hallmarks of various age-associated neurodegenerative diseases. Progress in our understanding of such processes heavily relies on quantitative fluorescence imaging of suitably tagged proteins. Fluorescence loss in photobleaching (FLIP) is particularly well-suited to study the dynamics of protein aggregation in cellular models of Chorea Huntington and other polyQ diseases, as FLIP gives access to the full spatio-temporal profile of intensity changes in the cell geometry. In contrast to other methods, also dim aggregates become visible during time evolution of fluorescence loss in cellular compartments. However, methods for computational analysis of FLIP data are sparse, and transport models for estimation of transport and diffusion parameters from experimental FLIP sequences are missing. Results In this paper, we present a computational method for analysis of FLIP imaging experiments of intracellular polyglutamine protein aggregates also called inclusion bodies (IBs). By this method, we can determine the diffusion constant and nuclear membrane transport coefficients of polyQ proteins as well as the exchange rates between aggregates and the cytoplasm. Our method is based on a reaction-diffusion multi-compartment model defined on a mesh obtained by segmentation of the cell images from the FLIP sequence. The discontinuous Galerkin (DG) method is used for numerical implementation of our model in FEniCS, which greatly reduces the computing time. The method is applied to representative experimental FLIP sequences, and consistent estimates of all transport parameters are obtained. Conclusions By directly estimating the transport parameters from live-cell image sequences using our new computational FLIP approach surprisingly fast exchange dynamics of mutant Huntingtin between cytoplasm and dim IBs could be revealed. This is likely relevant also for other polyQ diseases. Thus, our method allows for quantifying protein dynamics at different stages of the protein aggregation process in cellular models of neurodegeneration. Electronic supplementary material The online version of this article (10.1186/s13628-018-0046-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christian V Hansen
- 1Department of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, Odense M, 5230 Denmark
| | - Hans J Schroll
- 1Department of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, Odense M, 5230 Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, Campusvej 55, Odense M, 5230 Denmark
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23
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Weber JJ, Kloock SJ, Nagel M, Ortiz-Rios MM, Hofmann J, Riess O, Nguyen HP. Calpastatin ablation aggravates the molecular phenotype in cell and animal models of Huntington disease. Neuropharmacology 2018; 133:94-106. [PMID: 29355642 DOI: 10.1016/j.neuropharm.2018.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/21/2017] [Accepted: 01/16/2018] [Indexed: 12/15/2022]
Abstract
Deciphering the molecular pathology of Huntington disease is of particular importance, not only for a better understanding of this neurodegenerative disease, but also to identify potential therapeutic targets. The polyglutamine-expanded disease protein huntingtin was shown to undergo proteolysis, which results in the accumulation of toxic and aggregation-prone fragments. Amongst several classes of proteolytic enzymes responsible for huntingtin processing, the group of calcium-activated calpains has been found to be a significant mediator of the disease protein toxicity. To confirm the impact of calpain-mediated huntingtin cleavage in Huntington disease, we analysed the effect of depleting or overexpressing the endogenous calpain inhibitor calpastatin in HEK293T cells transfected with wild-type or polyglutamine-expanded huntingtin. Moreover, we crossbred huntingtin knock-in mice with calpastatin knockout animals to assess its effect not only on huntingtin cleavage and aggregation but also additional molecular markers. We demonstrated that a reduced or ablated expression of calpastatin triggers calpain overactivation and a consequently increased mutant huntingtin cleavage in cells and in vivo. These alterations were accompanied by an elevated formation of predominantly cytoplasmic huntingtin aggregates. On the other hand, overexpression of calpastatin in cells attenuated huntingtin fragmentation and aggregation. In addition, we observed an enhanced cleavage of DARPP-32, p35 and synapsin-1 in neuronal tissue upon calpain overactivation. Our results corroborate the important role of calpains in the molecular pathogenesis of Huntington disease and endorse targeting these proteolytic enzymes as a therapeutic approach.
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Affiliation(s)
- Jonasz Jeremiasz Weber
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Simon Johannes Kloock
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Maike Nagel
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Midea Malena Ortiz-Rios
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Julian Hofmann
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
| | - Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany; Centre for Rare Diseases, University of Tübingen, Calwerstraße 7, 72076, Tübingen, Germany.
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24
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Luis-Ravelo D, Estévez-Silva H, Barroso-Chinea P, Afonso-Oramas D, Salas-Hernández J, Rodríguez-Núñez J, Acevedo-Arozena A, Marcellino D, González-Hernández T. Pramipexole reduces soluble mutant huntingtin and protects striatal neurons through dopamine D3 receptors in a genetic model of Huntington's disease. Exp Neurol 2018; 299:137-147. [DOI: 10.1016/j.expneurol.2017.10.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/29/2017] [Accepted: 10/19/2017] [Indexed: 12/26/2022]
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25
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He WT, Xue W, Gao YG, Hong JY, Yue HW, Jiang LL, Hu HY. HSP90 recognizes the N-terminus of huntingtin involved in regulation of huntingtin aggregation by USP19. Sci Rep 2017; 7:14797. [PMID: 29093475 PMCID: PMC5666004 DOI: 10.1038/s41598-017-13711-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/27/2017] [Indexed: 11/09/2022] Open
Abstract
Huntington’s disease (HD) is caused by aberrant expansion of polyglutamine (polyQ) in the N-terminus of huntingtin (Htt). Our previous study has demonstrated that HSP90 is involved in the triage decision of Htt, but how HSP90 recognizes and regulates Htt remains elusive. We investigated the interaction between HSP90 and the N-terminal fragments of Htt (Htt-N), such as the N-terminal 90-residue fragment (Htt-N90). Our results showed that HSP90 binds to the N-terminal extreme of Htt-N in a sequence just ahead of the polyQ tract. Structural integration of the middle and C-terminal domains of HSP90 is essential for interacting with Htt-N90, and the dimerization mediated by the C-terminal domain facilitates this interaction. Moreover, ubiquitin-specific protease 19 (USP19), a deubiquitinating enzyme interacting with HSP90, up-regulates the protein level of Htt-N90 and consequently promotes its aggregation, whereas disruption of the interaction between Htt-N90 and HSP90 attenuates the effect of USP19 on Htt-N90. Thus, HSP90 interacts with Htt-N90 on the N-terminal amphipathic α-helix, and then recruits USP19 to modulate the protein level and aggregation of Htt-N90. This study provides mechanistic insights into the recognition between HSP90 and the N-terminus of Htt, and the triage decision for the Htt protein by the HSP90 chaperone system.
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Affiliation(s)
- Wen-Tian He
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Wei Xue
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Yong-Guang Gao
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Jun-Ye Hong
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Hong-Wei Yue
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, P. R. China.
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26
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Jimenez-Sanchez M, Licitra F, Underwood BR, Rubinsztein DC. Huntington's Disease: Mechanisms of Pathogenesis and Therapeutic Strategies. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a024240. [PMID: 27940602 DOI: 10.1101/cshperspect.a024240] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Huntington's disease is a late-onset neurodegenerative disease caused by a CAG trinucleotide repeat in the gene encoding the huntingtin protein. Despite its well-defined genetic origin, the molecular and cellular mechanisms underlying the disease are unclear and complex. Here, we review some of the currently known functions of the wild-type huntingtin protein and discuss the deleterious effects that arise from the expansion of the CAG repeats, which are translated into an abnormally long polyglutamine tract. Finally, we outline some of the therapeutic strategies that are currently being pursued to slow down the disease.
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Affiliation(s)
- Maria Jimenez-Sanchez
- Department of Medical Genetics, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge CB2 0XY, United Kingdom
| | - Floriana Licitra
- Department of Medical Genetics, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge CB2 0XY, United Kingdom
| | - Benjamin R Underwood
- Department of Old Age Psychiatry, Beechcroft, Fulbourn Hospital, Cambridge CB21 5EF, United Kingdom
| | - David C Rubinsztein
- Department of Medical Genetics, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge CB2 0XY, United Kingdom
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27
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Adegbuyiro A, Sedighi F, Pilkington AW, Groover S, Legleiter J. Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease. Biochemistry 2017; 56:1199-1217. [PMID: 28170216 DOI: 10.1021/acs.biochem.6b00936] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several hereditary neurological and neuromuscular diseases are caused by an abnormal expansion of trinucleotide repeats. To date, there have been 10 of these trinucleotide repeat disorders associated with an expansion of the codon CAG encoding glutamine (Q). For these polyglutamine (polyQ) diseases, there is a critical threshold length of the CAG repeat required for disease, and further expansion beyond this threshold is correlated with age of onset and symptom severity. PolyQ expansion in the translated proteins promotes their self-assembly into a variety of oligomeric and fibrillar aggregate species that accumulate into the hallmark proteinaceous inclusion bodies associated with each disease. Here, we review aggregation mechanisms of proteins with expanded polyQ-tracts, structural consequences of expanded polyQ ranging from monomers to fibrillar aggregates, the impact of protein context and post-translational modifications on aggregation, and a potential role for lipid membranes in aggregation. As the pathogenic mechanisms that underlie these disorders are often classified as either a gain of toxic function or loss of normal protein function, some toxic mechanisms associated with mutant polyQ tracts will also be discussed.
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Affiliation(s)
- Adewale Adegbuyiro
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Faezeh Sedighi
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Sharon Groover
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, 217 Clark Hall, West Virginia University , Morgantown, West Virginia 26506, United States.,Blanchette Rockefeller Neurosciences Institute, Robert C. Byrd Health Sciences Center, P.O. Box 9304, West Virginia University , Morgantown, West Virginia 26506, United States.,NanoSAFE, P.O. Box 6223, West Virginia University , Morgantown, West Virginia 26506, United States
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28
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Krench M, Littleton J. Neurotoxicity Pathways in Drosophila Models of the Polyglutamine Disorders. Curr Top Dev Biol 2017; 121:201-223. [DOI: 10.1016/bs.ctdb.2016.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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29
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Kumar S, Cieplak P. CaspNeuroD: a knowledgebase of predicted caspase cleavage sites in human proteins related to neurodegenerative diseases. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2016; 2016:baw142. [PMID: 28025335 PMCID: PMC5199200 DOI: 10.1093/database/baw142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/18/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022]
Abstract
Background: A variety of neurodegenerative diseases (NDs) have been associated with deregulated caspase activation that leads to neuronal death. Caspases appear to be involved in the molecular pathology of NDs by directly cleaving important proteins. For instance, several proteins involved in Alzheimer’s disease, including β-amyloid precursor protein (APP) and presenilins, are known to be cleaved by caspases. Therefore, cell death pathway may play a central role in many neurological diseases, and targeting the important proteins that control the cell survival and death may potentially represent a therapeutic approach for chronic neurodegenerative disorders. Findings: We developed CaspNeuroD, a relational database of in silico predicted caspase cleavage sites in human proteins associated with NDs. The prediction has been done on collection of 249 human proteins reported in clinical studies of NDs using the recently published CaspDB Random Forest machine-learning model. This database could be used for identifying new caspase substrates and further our understanding of the caspase-mediated substrate cleavage in NDs. Conclusion: Our database provides information about potential caspase cleavage sites in a verified set of human proteins involved in NDs. It provides also information about the conservation of cleavage positions in corresponding orthologs, and information about the positions of single nucleotide polymorphisms and posttranslational modifications (PTMs) that may modulate the caspase cleavage efficiency. Database URL:caspdb.sanfordburnham.org/caspneurod.php .
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Affiliation(s)
- Sonu Kumar
- SBP Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Piotr Cieplak
- SBP Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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30
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Kino Y, Washizu C, Kurosawa M, Yamada M, Doi H, Takumi T, Adachi H, Katsuno M, Sobue G, Hicks GG, Hattori N, Shimogori T, Nukina N. FUS/TLS acts as an aggregation-dependent modifier of polyglutamine disease model mice. Sci Rep 2016; 6:35236. [PMID: 27739513 PMCID: PMC5064419 DOI: 10.1038/srep35236] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 09/26/2016] [Indexed: 12/13/2022] Open
Abstract
FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington's disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of (HD, but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/- double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration.
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Affiliation(s)
- Yoshihiro Kino
- CREST(Core Research for Evolutionary Science and Technology), JST, Saitama, Japan.,Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory for Structural Neuropathology , Brain Science Institute, RIKEN, Saitama, Japan.,Laboratory for Molecular Mechanisms of Thalamus Development, Brain Science Institute, RIKEN, Saitama, Japan.,Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan
| | - Chika Washizu
- Laboratory for Structural Neuropathology , Brain Science Institute, RIKEN, Saitama, Japan
| | - Masaru Kurosawa
- CREST(Core Research for Evolutionary Science and Technology), JST, Saitama, Japan.,Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory for Structural Neuropathology , Brain Science Institute, RIKEN, Saitama, Japan.,Laboratory for Molecular Mechanisms of Thalamus Development, Brain Science Institute, RIKEN, Saitama, Japan
| | - Mizuki Yamada
- Laboratory for Structural Neuropathology , Brain Science Institute, RIKEN, Saitama, Japan
| | - Hiroshi Doi
- Department of Clinical Neurology and Stroke Medicine, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Toru Takumi
- CREST(Core Research for Evolutionary Science and Technology), JST, Saitama, Japan.,Laboratory for Mental Biology, Brain Science Institute, RIKEN, Saitama, Japan.,Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiroaki Adachi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Gen Sobue
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Geoffrey G Hicks
- Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Canada
| | - Nobutaka Hattori
- Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tomomi Shimogori
- Laboratory for Molecular Mechanisms of Thalamus Development, Brain Science Institute, RIKEN, Saitama, Japan
| | - Nobuyuki Nukina
- CREST(Core Research for Evolutionary Science and Technology), JST, Saitama, Japan.,Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory for Structural Neuropathology , Brain Science Institute, RIKEN, Saitama, Japan.,Laboratory for Molecular Mechanisms of Thalamus Development, Brain Science Institute, RIKEN, Saitama, Japan.,Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, Kyoto, Japan
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31
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Ni CL, Seth D, Fonseca FV, Wang L, Xiao TS, Gruber P, Sy MS, Stamler JS, Tartakoff AM. Polyglutamine Tract Expansion Increases S-Nitrosylation of Huntingtin and Ataxin-1. PLoS One 2016; 11:e0163359. [PMID: 27658206 PMCID: PMC5033456 DOI: 10.1371/journal.pone.0163359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/07/2016] [Indexed: 11/19/2022] Open
Abstract
Expansion of the polyglutamine (polyQ) tract in the huntingtin (Htt) protein causes Huntington’s disease (HD), a fatal inherited movement disorder linked to neurodegeneration in the striatum and cortex. S-nitrosylation and S-acylation of cysteine residues regulate many functions of cytosolic proteins. We therefore used a resin-assisted capture approach to identify these modifications in Htt. In contrast to many proteins that have only a single S-nitrosylation or S-acylation site, we identified sites along much of the length of Htt. Moreover, analysis of cells expressing full-length Htt or a large N-terminal fragment of Htt shows that polyQ expansion strongly increases Htt S-nitrosylation. This effect appears to be general since it is also observed in Ataxin-1, which causes spinocerebellar ataxia type 1 (SCA1) when its polyQ tract is expanded. Overexpression of nitric oxide synthase increases the S-nitrosylation of normal Htt and the frequency of conspicuous juxtanuclear inclusions of Htt N-terminal fragments in transfected cells. Taken together with the evidence that S-nitrosylation of Htt is widespread and parallels polyQ expansion, these subcellular changes show that S-nitrosylation affects the biology of this protein in vivo.
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Affiliation(s)
- Chun-Lun Ni
- Cell Biology Program, Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Divya Seth
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Fabio Vasconcelos Fonseca
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Liwen Wang
- Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Tsan Sam Xiao
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Phillip Gruber
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Man-Sun Sy
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Jonathan S. Stamler
- Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, 44106, United States of America
| | - Alan M. Tartakoff
- Cell Biology Program, Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
- Department of Pathology, Case Western Reserve University, Cleveland, OH, 44106, United States of America
- * E-mail:
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32
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Arndt JR, Chaibva M, Legleiter J. The emerging role of the first 17 amino acids of huntingtin in Huntington's disease. Biomol Concepts 2016; 6:33-46. [PMID: 25741791 DOI: 10.1515/bmc-2015-0001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 02/09/2015] [Indexed: 01/01/2023] Open
Abstract
Huntington's disease (HD) is caused by a polyglutamine (polyQ) domain that is expanded beyond a critical threshold near the N-terminus of the huntingtin (htt) protein, directly leading to htt aggregation. While full-length htt is a large (on the order of ∼350 kDa) protein, it is proteolyzed into a variety of N-terminal fragments that accumulate in oligomers, fibrils, and larger aggregates. It is clear that polyQ length is a key determinant of htt aggregation and toxicity. However, the flanking sequences around the polyQ domain, such as the first 17 amino acids on the N terminus (Nt17), influence aggregation, aggregate stability, influence other important biochemical properties of the protein and ultimately its role in pathogenesis. Here, we review the impact of Nt17 on htt aggregation mechanisms and kinetics, structural properties of Nt17 in both monomeric and aggregate forms, the potential role of posttranslational modifications (PTMs) that occur in Nt17 in HD, and the function of Nt17 as a membrane targeting domain.
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33
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Macakova M, Bohuslavova B, Vochozkova P, Pavlok A, Sedlackova M, Vidinska D, Vochyanova K, Liskova I, Valekova I, Baxa M, Ellederova Z, Klima J, Juhas S, Juhasova J, Klouckova J, Haluzik M, Klempir J, Hansikova H, Spacilova J, Collins R, Blumenthal I, Talkowski M, Gusella JF, Howland DS, DiFiglia M, Motlik J. Mutated Huntingtin Causes Testicular Pathology in Transgenic Minipig Boars. NEURODEGENER DIS 2016; 16:245-59. [PMID: 26959244 DOI: 10.1159/000443665] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 12/23/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Huntington's disease is induced by CAG expansion in a single gene coding the huntingtin protein. The mutated huntingtin (mtHtt) primarily causes degeneration of neurons in the brain, but it also affects peripheral tissues, including testes. OBJECTIVE We studied sperm and testes of transgenic boars expressing the N-terminal region of human mtHtt. METHODS In this study, measures of reproductive parameters and electron microscopy (EM) images of spermatozoa and testes of transgenic (TgHD) and wild-type (WT) boars of F1 (24-48 months old) and F2 (12-36 months old) generations were compared. In addition, immunofluorescence, immunohistochemistry, Western blot, hormonal analysis and whole-genome sequencing were done in order to elucidate the effects of mtHtt. RESULTS Evidence for fertility failure of both TgHD generations was observed at the age of 13 months. Reproductive parameters declined and progressively worsened with age. EM revealed numerous pathological features in sperm tails and in testicular epithelium from 24- and 36-month-old TgHD boars. Moreover, immunohistochemistry confirmed significantly lower proliferation activity of spermatogonia in transgenic testes. mtHtt was highly expressed in spermatozoa and testes of TgHD boars and localized in all cells of seminiferous tubules. Levels of fertility-related hormones did not differ in TgHD and WT siblings. Genome analysis confirmed that insertion of the lentiviral construct did not interrupt any coding sequence in the pig genome. CONCLUSIONS The sperm and testicular degeneration of TgHD boars is caused by gain-of-function of the highly expressed mtHtt.
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Affiliation(s)
- Monika Macakova
- Laboratory of Cell Regeneration and Plasticity, Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czech Republic
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Multidrug resistance protein 1 reduces the aggregation of mutant huntingtin in neuronal cells derived from the Huntington's disease R6/2 model. Sci Rep 2015; 5:16887. [PMID: 26586297 PMCID: PMC4653614 DOI: 10.1038/srep16887] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 10/16/2015] [Indexed: 11/13/2022] Open
Abstract
Mutant huntingtin (mHtt) aggregation in the nucleus is the most readily apparent phenotype and cause of neuronal death in Huntington’s disease (HD). Inhibiting mHtt aggregation reduces cell death in the brain and is thus a promising therapeutic approach. The results of the present study demonstrated that mHtt aggregation in the nucleus was altered by the activity of multidrug resistance protein 1 (MDR1), which was experimentally modulated by verapamil, siRNA and an expression vector. MDR1 detoxifies drugs and metabolites through its excretory functions in the membrane compartment, thereby protecting cells against death or senescence. When they were treated with verapamil, R6/2 mice showed a progressive decline in rotarod performance and increased mHtt aggregation in the brain. Using neuronal stem cells from R6/2 mice, we developed an in vitro HD model to test mHtt accumulation in the nuclei of neurons. When MDR1 activity in cells was decreased by verapamil or siRNA, mHtt aggregation in the nuclei increased, whereas the induction of MDR1 resulted in a decrease in mHtt aggregation. Thus, our data provide evidence that MDR1 plays an important role in the clearance of mHtt aggregation and may thus be a potential target for improving the survival of neurons in Huntington’s disease.
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35
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Clemens LE, Weber JJ, Wlodkowski TT, Yu-Taeger L, Michaud M, Calaminus C, Eckert SH, Gaca J, Weiss A, Magg JCD, Jansson EKH, Eckert GP, Pichler BJ, Bordet T, Pruss RM, Riess O, Nguyen HP. Olesoxime suppresses calpain activation and mutant huntingtin fragmentation in the BACHD rat. Brain 2015; 138:3632-53. [PMID: 26490331 DOI: 10.1093/brain/awv290] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 08/11/2015] [Indexed: 12/14/2022] Open
Abstract
Huntington's disease is a fatal human neurodegenerative disorder caused by a CAG repeat expansion in the HTT gene, which translates into a mutant huntingtin protein. A key event in the molecular pathogenesis of Huntington's disease is the proteolytic cleavage of mutant huntingtin, leading to the accumulation of toxic protein fragments. Mutant huntingtin cleavage has been linked to the overactivation of proteases due to mitochondrial dysfunction and calcium derangements. Here, we investigated the therapeutic potential of olesoxime, a mitochondria-targeting, neuroprotective compound, in the BACHD rat model of Huntington's disease. BACHD rats were treated with olesoxime via the food for 12 months. In vivo analysis covered motor impairments, cognitive deficits, mood disturbances and brain atrophy. Ex vivo analyses addressed olesoxime's effect on mutant huntingtin aggregation and cleavage, as well as brain mitochondria function. Olesoxime improved cognitive and psychiatric phenotypes, and ameliorated cortical thinning in the BACHD rat. The treatment reduced cerebral mutant huntingtin aggregates and nuclear accumulation. Further analysis revealed a cortex-specific overactivation of calpain in untreated BACHD rats. Treated BACHD rats instead showed significantly reduced levels of mutant huntingtin fragments due to the suppression of calpain-mediated cleavage. In addition, olesoxime reduced the amount of mutant huntingtin fragments associated with mitochondria, restored a respiration deficit, and enhanced the expression of fusion and outer-membrane transport proteins. In conclusion, we discovered the calpain proteolytic system, a key player in Huntington's disease and other neurodegenerative disorders, as a target of olesoxime. Our findings suggest that olesoxime exerts its beneficial effects by improving mitochondrial function, which results in reduced calpain activation. The observed alleviation of behavioural and neuropathological phenotypes encourages further investigations on the use of olesoxime as a therapeutic for Huntington's disease.
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Affiliation(s)
- Laura E Clemens
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Jonasz J Weber
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Tanja T Wlodkowski
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Libo Yu-Taeger
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Magali Michaud
- 3 Trophos SA., Parc Scientifique de Luminy Case 931, 13288 Marseille Cedex 9, France
| | - Carsten Calaminus
- 4 Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of Tuebingen, Roentgenweg 13, 72076 Tuebingen, Germany
| | - Schamim H Eckert
- 5 Department of Pharmacology, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Janett Gaca
- 5 Department of Pharmacology, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Andreas Weiss
- 6 Novartis Institutes for BioMedical Research, Klybeckstrasse 141, 4057 Basel, Switzerland
| | - Janine C D Magg
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Erik K H Jansson
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Gunter P Eckert
- 5 Department of Pharmacology, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, 60438 Frankfurt, Germany
| | - Bernd J Pichler
- 4 Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of Tuebingen, Roentgenweg 13, 72076 Tuebingen, Germany
| | - Thierry Bordet
- 3 Trophos SA., Parc Scientifique de Luminy Case 931, 13288 Marseille Cedex 9, France
| | - Rebecca M Pruss
- 3 Trophos SA., Parc Scientifique de Luminy Case 931, 13288 Marseille Cedex 9, France
| | - Olaf Riess
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
| | - Huu P Nguyen
- 1 Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany 2 Centre for Rare Diseases, University of Tuebingen, Calwerstrasse 7, 72076 Tuebingen, Germany
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Xu Z, Tito AJ, Rui YN, Zhang S. Studying polyglutamine diseases in Drosophila. Exp Neurol 2015; 274:25-41. [PMID: 26257024 DOI: 10.1016/j.expneurol.2015.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 08/02/2015] [Accepted: 08/03/2015] [Indexed: 12/16/2022]
Abstract
Polyglutamine (polyQ) diseases are a family of dominantly transmitted neurodegenerative disorders caused by an abnormal expansion of CAG trinucleotide repeats in the protein-coding regions of the respective disease-causing genes. Despite their simple genetic basis, the etiology of these diseases is far from clear. Over the past two decades, Drosophila has proven to be successful in modeling this family of neurodegenerative disorders, including the faithful recapitulation of pathological features such as polyQ length-dependent formation of protein aggregates and progressive neuronal degeneration. Additionally, it has been valuable in probing the pathogenic mechanisms, in identifying and evaluating disease modifiers, and in helping elucidate the normal functions of disease-causing genes. Knowledge learned from this simple invertebrate organism has had a large impact on our understanding of these devastating brain diseases.
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Affiliation(s)
- Zhen Xu
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Antonio Joel Tito
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; Programs in Human and Molecular Genetics and Neuroscience, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Graduate School of Biomedical Sciences, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Yan-Ning Rui
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States
| | - Sheng Zhang
- The Brown Foundation Institute of Molecular Medicine, 1825 Pressler Street, Houston, TX 77030, United States; Department of Neurobiology and Anatomy, 1825 Pressler Street, Houston, TX 77030, United States; Programs in Human and Molecular Genetics and Neuroscience, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Graduate School of Biomedical Sciences, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Medical School at Houston, 1825 Pressler Street, Houston, TX 77030, United States; The University of Texas Health Science Center at Houston (UTHealth), 1825 Pressler Street, Houston, TX 77030, United States.
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Huntingtin is required for ciliogenesis and neurogenesis during early Xenopus development. Dev Biol 2015; 408:305-15. [PMID: 26192473 DOI: 10.1016/j.ydbio.2015.07.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/09/2015] [Accepted: 07/13/2015] [Indexed: 11/21/2022]
Abstract
Huntington's Disease (HD) is a neurodegenerative disorder that results from the abnormal expansion of poly-glutamine (polyQ) repeats in the Huntingtin (HTT) gene. Although HTT has been linked to a variety of cellular events, it is still not clear what the physiological functions of the protein are. Because of its critical role during mouse embryonic mouse development, we investigated the functions of Htt during early Xenopus embryogenesis. We find that reduction of Htt levels affects cilia polarity and function and causes whole body paralysis. Moreover, Htt loss of function leads to abnormal development of trigeminal and motor neurons. Interestingly, these phenotypes are partially rescued by either wild-type or expanded HTT. These results show that the Htt activity is required for normal embryonic development, and highlight the usefulness of the Xenopus system for investigating proteins involved in human diseases.
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El-Daher MT, Hangen E, Bruyère J, Poizat G, Al-Ramahi I, Pardo R, Bourg N, Souquere S, Mayet C, Pierron G, Lévêque-Fort S, Botas J, Humbert S, Saudou F. Huntingtin proteolysis releases non-polyQ fragments that cause toxicity through dynamin 1 dysregulation. EMBO J 2015; 34:2255-71. [PMID: 26165689 DOI: 10.15252/embj.201490808] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 06/12/2015] [Indexed: 12/11/2022] Open
Abstract
Cleavage of mutant huntingtin (HTT) is an essential process in Huntington's disease (HD), an inherited neurodegenerative disorder. Cleavage generates N-ter fragments that contain the polyQ stretch and whose nuclear toxicity is well established. However, the functional defects induced by cleavage of full-length HTT remain elusive. Moreover, the contribution of non-polyQ C-terminal fragments is unknown. Using time- and site-specific control of full-length HTT proteolysis, we show that specific cleavages are required to disrupt intramolecular interactions within HTT and to cause toxicity in cells and flies. Surprisingly, in addition to the canonical pathogenic N-ter fragments, the C-ter fragments generated, that do not contain the polyQ stretch, induced toxicity via dilation of the endoplasmic reticulum (ER) and increased ER stress. C-ter HTT bound to dynamin 1 and subsequently impaired its activity at ER membranes. Our findings support a role for HTT on dynamin 1 function and ER homoeostasis. Proteolysis-induced alteration of this function may be relevant to disease.
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Affiliation(s)
| | - Emilie Hangen
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Julie Bruyère
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France
| | - Ghislaine Poizat
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Raul Pardo
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Nicolas Bourg
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Sylvie Souquere
- CNRS UMR8122, Villejuif, France Institut Gustave Roussy, Villejuif, France
| | - Céline Mayet
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Gérard Pierron
- CNRS UMR8122, Villejuif, France Institut Gustave Roussy, Villejuif, France
| | - Sandrine Lévêque-Fort
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Juan Botas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sandrine Humbert
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France
| | - Frédéric Saudou
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France CHU de Grenoble, Grenoble, France
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Milewski M, Gawliński P, Bąk D, Matysiak A, Bal J. Complex interplay between the length and composition of the huntingtin-derived peptides modulates the intracellular behavior of the N-terminal fragments of mutant huntingtin. Eur J Cell Biol 2015; 94:179-89. [PMID: 25773959 DOI: 10.1016/j.ejcb.2015.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 01/04/2023] Open
Abstract
Diverse subcellular localizations of the huntingtin-containing inclusion bodies are frequently suspected of reflecting crucial divisions between different cellular pathways contributing to the pathophysiology of Huntington's disease. Here, we use a panel of different N-terminal huntingtin fragments overexpressed in transfected neuronal and non-neuronal cells to demonstrate that it is the length of the N-terminal huntingtin fragments rather than a presence of any specific amino acid sequences that determines the ratio between the nuclear and cytoplasmic inclusion bodies. Importantly, the length of those fragments does also seem to strongly influence the folding of the aggregating huntingtin species, as indicated by the apparent differences in their accessibility for different antibodies directed against particular subdomains within the N-terminal part of huntingtin, although these differences do not correlate with the peptides' ability to efficiently aggregate within the cell nucleus. Furthermore, the relatively long huntingtin fragment containing 588 amino acids of the reference sequence shows intracellular behavior that is substantially different from that exhibited by its shorter counterparts (containing either 171, 120, 89 or 64 amino acids), as this rarely aggregating peptide is not only accumulating in cytoplasmic inclusions of slightly different morphology but is also most strongly affected by the FLAG-tagging procedure that unexpectedly induces (or enhances) autophagy-related processes. Together, our results reveal a significant heterogeneity of the huntingtin accumulation patterns that are observed at the cellular level. These patterns are not only strongly dependent on both the length and the amino acid composition of the N-terminal huntingtin peptides but also seem to engage different cellular mechanisms implicated in the pathogenesis of Huntington's disease, including the non-proteasomal degradation of potentially toxic huntingtin forms.
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Affiliation(s)
- Michał Milewski
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland.
| | - Paweł Gawliński
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Daniel Bąk
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Agata Matysiak
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland; Institute of Genetics and Biotechnology, Warsaw University, Warsaw, Poland
| | - Jerzy Bal
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
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Wang XJ, Cao Q, Zhang Y, Su XD. Activation and regulation of caspase-6 and its role in neurodegenerative diseases. Annu Rev Pharmacol Toxicol 2014; 55:553-72. [PMID: 25340928 DOI: 10.1146/annurev-pharmtox-010814-124414] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Caspases, a family of cysteine proteases, are major mediators of apoptosis and inflammation. Caspase-6 is classified as an apoptotic effector, and it mediates nuclear shrinkage during apoptosis, but it possesses unique activation and regulation mechanisms that differ from those of other effector caspases. Furthermore, increasing evidence has shown that caspase-6 is highly involved in axon degeneration and neurodegenerative diseases, such as Huntington's disease and Alzheimer's disease. Cleavage at the caspase-6 site in mutated huntingtin protein is a prerequisite for the development of the characteristic behavioral and neuropathological features of Huntington's disease. Active caspase-6 is present in early stages of Alzheimer's disease, and caspase-6 activity is associated with the disease's pathological lesions. In this review, we discuss the evidence relevant to the role of caspase-6 in neurodegenerative diseases and summarize its activation and regulation mechanisms. In doing so, we provide new insight about potential therapeutic approaches that incorporate the modulation of caspase-6 function for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Xiao-Jun Wang
- State Key Laboratory of Protein and Plant Gene Research and
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41
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From pathways to targets: understanding the mechanisms behind polyglutamine disease. BIOMED RESEARCH INTERNATIONAL 2014; 2014:701758. [PMID: 25309920 PMCID: PMC4189765 DOI: 10.1155/2014/701758] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 09/03/2014] [Indexed: 12/27/2022]
Abstract
The history of polyglutamine diseases dates back approximately 20 years to the discovery of a polyglutamine repeat in the androgen receptor of SBMA followed by the identification of similar expansion mutations in Huntington's disease, SCA1, DRPLA, and the other spinocerebellar ataxias. This common molecular feature of polyglutamine diseases suggests shared mechanisms in disease pathology and neurodegeneration of disease specific brain regions. In this review, we discuss the main pathogenic pathways including proteolytic processing, nuclear shuttling and aggregation, mitochondrial dysfunction, and clearance of misfolded polyglutamine proteins and point out possible targets for treatment.
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42
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Pla P, Orvoen S, Saudou F, David DJ, Humbert S. Mood disorders in Huntington's disease: from behavior to cellular and molecular mechanisms. Front Behav Neurosci 2014; 8:135. [PMID: 24795586 PMCID: PMC4005937 DOI: 10.3389/fnbeh.2014.00135] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/03/2014] [Indexed: 01/29/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder that is best known for its effect on motor control. Mood disturbances such as depression, anxiety, and irritability also have a high prevalence in patients with HD, and often start before the onset of motor symptoms. Various rodent models of HD recapitulate the anxiety/depressive behavior seen in patients. HD is caused by an expanded polyglutamine stretch in the N-terminal part of a 350 kDa protein called huntingtin (HTT). HTT is ubiquitously expressed and is implicated in several cellular functions including control of transcription, vesicular trafficking, ciliogenesis, and mitosis. This review summarizes progress in efforts to understand the cellular and molecular mechanisms underlying behavioral disorders in patients with HD. Dysfunctional HTT affects cellular pathways that are involved in mood disorders or in the response to antidepressants, including BDNF/TrkB and serotonergic signaling. Moreover, HTT affects adult hippocampal neurogenesis, a physiological phenomenon that is implicated in some of the behavioral effects of antidepressants and is linked to the control of anxiety. These findings are consistent with the emerging role of wild-type HTT as a crucial component of neuronal development and physiology. Thus, the pathogenic polyQ expansion in HTT could lead to mood disorders not only by the gain of a new toxic function but also by the perturbation of its normal function.
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Affiliation(s)
- Patrick Pla
- Institut Curie Orsay, France ; CNRS UMR3306 Orsay, France ; INSERM U1005 Orsay, France ; Faculté des Sciences, Université Paris-Sud Orsay, France
| | - Sophie Orvoen
- EA3544, Faculté de Pharmacie, Université Paris-Sud Châtenay-Malabry, France
| | - Frédéric Saudou
- Institut Curie Orsay, France ; CNRS UMR3306 Orsay, France ; INSERM U1005 Orsay, France
| | - Denis J David
- EA3544, Faculté de Pharmacie, Université Paris-Sud Châtenay-Malabry, France
| | - Sandrine Humbert
- Institut Curie Orsay, France ; CNRS UMR3306 Orsay, France ; INSERM U1005 Orsay, France
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43
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Kantcheva RB, Mason R, Giorgini F. Aggregation-prone proteins modulate huntingtin inclusion body formation in yeast. PLOS CURRENTS 2014; 6. [PMID: 24804153 PMCID: PMC4006944 DOI: 10.1371/currents.hd.501008f3051342c9a5c0cd0f3a5bf3a4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin (HTT) protein. The expression of mutant HTT in the baker's yeast Saccharomyces cerevisiae recapitulates many of the cellular phenotypes observed in mammalian HD models. Mutant HTT aggregation and toxicity in yeast is influenced by the presence of the Rnq1p and Sup35p prions, as well as other glutamine/asparagine-rich aggregation-prone proteins. Here we investigated the ability of a subset of these proteins to modulate mutant HTT aggregation and to substitute for the prion form of Rnq1p. We find that overexpression of either the putative prion Ybr016wp or the Sup35p prion restores aggregation of mutant HTT in yeast cells lacking the Rnq1p prion. These results indicate that an interchangeable suite of aggregation-prone proteins regulates mutant HTT aggregation dynamics in yeast, which may have implications for mutant HTT aggregation in human cells.
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Affiliation(s)
| | - Robert Mason
- Department of Genetics, University of Leicester, Leicester, UK
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44
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Dolezalova D, Hruska-Plochan M, Bjarkam CR, Sørensen JCH, Cunningham M, Weingarten D, Ciacci JD, Juhas S, Juhasova J, Motlik J, Hefferan MP, Hazel T, Johe K, Carromeu C, Muotri A, Bui J, Strnadel J, Marsala M. Pig models of neurodegenerative disorders: Utilization in cell replacement-based preclinical safety and efficacy studies. J Comp Neurol 2014; 522:2784-801. [DOI: 10.1002/cne.23575] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Dasa Dolezalova
- Department of Anesthesiology; University of California; San Diego La Jolla CA USA
| | | | - Carsten R. Bjarkam
- Department of Neurosurgery; Aalborg University Hospital; Aalborg Denmark
- Department of Biomedicine; Institute of Anatomy, University of Aarhus; Aarhus Denmark
| | | | - Miles Cunningham
- MRC 312, McLean Hospital, Harvard Medical School; Belmont MA 02478 USA
| | - David Weingarten
- UCSD Division of Neurosurgery; University of California; San Diego CA USA
| | - Joseph D. Ciacci
- UCSD Division of Neurosurgery; University of California; San Diego CA USA
| | - Stefan Juhas
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences; 277 21 Libechov Czech Republic
| | - Jana Juhasova
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences; 277 21 Libechov Czech Republic
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences; 277 21 Libechov Czech Republic
| | | | | | | | - Cassiano Carromeu
- Department of Cellular and Molecular Medicine; University of California; San Diego CA USA
| | - Alysson Muotri
- Department of Cellular and Molecular Medicine; University of California; San Diego CA USA
| | - Jack Bui
- Department of Pathology; University of California; San Diego CA USA
| | - Jan Strnadel
- Department of Pathology; University of California; San Diego CA USA
| | - Martin Marsala
- Department of Anesthesiology; University of California; San Diego La Jolla CA USA
- Institute of Neurobiology, Slovak Academy of Sciences; Kosice Slovakia
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45
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Sanders SS, Mui KKN, Sutton LM, Hayden MR. Identification of binding sites in Huntingtin for the Huntingtin Interacting Proteins HIP14 and HIP14L. PLoS One 2014; 9:e90669. [PMID: 24651384 PMCID: PMC3947954 DOI: 10.1371/journal.pone.0090669] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 02/04/2014] [Indexed: 11/26/2022] Open
Abstract
Huntington disease is an adult onset neurodegenerative disease characterized by motor, cognitive, and psychiatric dysfunction, caused by a CAG expansion in the HTT gene. Huntingtin Interacting Protein 14 (HIP14) and Huntingtin Interacting Protein 14-like (HIP14L) are palmitoyl acyltransferases (PATs), enzymes that mediate the post-translational addition of long chain fatty acids to proteins in a process called palmitoylation. HIP14 and HIP14L interact with and palmitoylate HTT and are unique among PATs as they are the only two that have an ankyrin repeat domain, which mediates the interaction between HIP14 and HTT. These enzymes show reduced interaction with and palmitoylation of mutant HTT, leading to increased mutant HTT inclusion formation and toxicity. The interaction between HIP14 and HTT goes beyond that of only an enzyme–substrate interaction as HTT is essential for the full enzymatic activity of HIP14. It is important to further understand and characterize the interactions of HTT with HIP14 and HIP14L to guide future efforts to target and enhance this interaction and increase enzyme activity to remediate palmitoylation of HTT and their substrates, as well as to understand the relationship between the three proteins. HIP14 and HIP14L have been previously shown to interact with HTT amino acids 1–548. Here the interaction of HIP14 and HIP14L with N- and C-terminal HTT 1–548 deletion mutations was assessed. We show that HTT amino acids 1–548 were sufficient for full interaction of HTT with HIP14 and HIP14L, but partial interaction was also possible with HTT 1–427 and HTT 224–548. To further characterize the binding domain we assessed the interaction of HIP14-GFP and HIP14L-GFP with 15Q HTT 1-548Δ257-315. Both enzymes showed reduced but not abolished interaction with 15Q HTT 1-548Δ257-315. This suggests that two potential binding domains exist, one around residues 224 and the other around 427, for the PAT enzymes HIP14 and HIP14L.
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Affiliation(s)
- Shaun S. Sanders
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine K. N. Mui
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Liza M. Sutton
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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46
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Caron NS, Hung CL, Atwal RS, Truant R. Live cell imaging and biophotonic methods reveal two types of mutant huntingtin inclusions. Hum Mol Genet 2013; 23:2324-38. [PMID: 24334607 DOI: 10.1093/hmg/ddt625] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominant, neurodegenerative disorder that can be characterized by the presence of protein inclusions containing mutant huntingtin within a subset of neurons in the brain. Since their discovery, the relevance of inclusions to disease pathology has been controversial. We show using super-resolution fluorescence imaging and Förster resonance energy transfer (FRET) in live cells, that mutant huntingtin fragments can form two morphologically and conformationally distinct inclusion types. Using fluorescence recovery after photobleaching (FRAP), we demonstrate that the two huntingtin inclusion types have unique dynamic properties. The ability to form one or the other type of inclusion can be influenced by the phosphorylation state of serine residues at amino acid positions 13 and 16 within the huntingtin protein. We can define two types of inclusions: fibrillar, which are tightly packed, do not exchange protein with the soluble phase, and result from phospho-modification at serines 13 and 16 of the N17 domain, and globular, which are loosely packed, can readily exchange with the soluble phase, and are not phosphorylated in N17. We hypothesize that the protective effect of N17 phosphorylation or phospho-mimicry seen in animal models, at the level of protein inclusions with elevated huntingtin levels, is to induce a conformation of the huntingtin amino-terminus that causes fragments to form tightly packed inclusions that do not exit the insoluble phase, and hence exert less toxicity. The identification of these sub-types of huntingtin inclusions could allow for drug discovery to promote protective inclusions of mutant huntingtin protein in HD.
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Affiliation(s)
- Nicholas S Caron
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada L8N 3Z5
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47
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Soluble forms of polyQ-expanded huntingtin rather than large aggregates cause endoplasmic reticulum stress. Nat Commun 2013; 4:2753. [DOI: 10.1038/ncomms3753] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/11/2013] [Indexed: 11/08/2022] Open
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Bard J, Wall MD, Lazari O, Arjomand J, Munoz-Sanjuan I. Advances in huntington disease drug discovery: novel approaches to model disease phenotypes. ACTA ACUST UNITED AC 2013; 19:191-204. [PMID: 24196395 DOI: 10.1177/1087057113510320] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Huntington disease is a monogenic, autosomal dominant, progressive neurodegenerative disorder caused by a trinucleotide CAG repeat expansion in exon 1 of the huntingtin (HTT) gene; age of onset of clinical symptoms inversely correlates with expanded CAG repeat length. HD leads to extensive degeneration of the basal ganglia, hypothalamic nuclei, and selected cortical areas, and a wide range of molecular mechanisms have been implicated in disease pathology in animal or cellular models expressing mutated HTT (mHTT) proteins, either full-length or amino-terminal fragments. However, HD cellular models that recapitulate the slow progression of the disease have not been available due to the toxicity of overexpressed exogenous mHTT or to limitations with using primary cells for long-term studies. Most investigations of the effects of mHTT relied on cytotoxicity or aggregation end points in heterologous systems or in primary embryonic neuroglial cultures derived from HD mouse models. More innovative approaches are currently under active investigation, including screening using electrophysiological endpoints, as well as the recent use of primary blood mononuclear cells and of human embryonic stem cells derived from a variety of HD research participants. Here we describe how these cellular systems are being used to investigate HD biology as well as to identify mechanisms with therapeutic potential.
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Affiliation(s)
- Jonathan Bard
- 1CHDI Management/CHDI Foundation, Princeton, NJ, and Los Angeles, CA, USA
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49
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Clabough EBD. Huntington's disease: the past, present, and future search for disease modifiers. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2013; 86:217-33. [PMID: 23766742 PMCID: PMC3670441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant genetic disorder that specifically causes neurodegeneration of striatal neurons, resulting in a triad of symptoms that includes emotional, cognitive, and motor disturbances. The HD mutation causes a polyglutamine repeat expansion within the N-terminal of the huntingtin (Htt) protein. This expansion causes aggregate formation within the cytosol and nucleus due to the presence of misfolded mutant Htt, as well as altered interactions with Htt's multiple binding partners, and changes in post-translational Htt modifications. The present review charts efforts toward a therapy that delays age of onset or slows symptom progression in patients affected by HD, as there is currently no effective treatment. Although silencing Htt expression appears promising as a disease modifying treatment, it should be attempted with caution in light of Htt's essential roles in neural maintenance and development. Other therapeutic targets include those that boost aggregate dissolution, target excitotoxicity and metabolic issues, and supplement growth factors.
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Affiliation(s)
- Erin B D Clabough
- Randolph-Macon College, Department of Biology, Ashland, Virginia 23005, USA.
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50
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Disease modeling and drug screening for neurological diseases using human induced pluripotent stem cells. Acta Pharmacol Sin 2013; 34:755-64. [PMID: 23685955 PMCID: PMC3674515 DOI: 10.1038/aps.2013.63] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
With the general decline of pharmaceutical research productivity, there are concerns that many components of the drug discovery process need to be redesigned and optimized. For example, the human immortalized cell lines or animal primary cells commonly used in traditional drug screening may not faithfully recapitulate the pathological mechanisms of human diseases, leading to biases in assays, targets, or compounds that do not effectively address disease mechanisms. Recent advances in stem cell research, especially in the development of induced pluripotent stem cell (iPSC) technology, provide a new paradigm for drug screening by permitting the use of human cells with the same genetic makeup as the patients without the typical quantity constraints associated with patient primary cells. In this article, we will review the progress made to date on cellular disease models using human stem cells, with a focus on patient-specific iPSCs for neurological diseases. We will discuss the key challenges and the factors that associated with the success of using stem cell models for drug discovery through examples from monogenic diseases, diseases with various known genetic components, and complex diseases caused by a combination of genetic, environmental and other factors.
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