1
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Meng Z, Saei AA, Gharibi H, Zhang X, Lyu H, Lundström SL, Végvári Á, Gaetani M, Zubarev RA. Gel-Assisted Proteome Position Integral Shift Assay Returns Molecular Weight to Shotgun Proteomics and Identifies Caspase 3 Substrates. Anal Chem 2024; 96:13533-13541. [PMID: 39110629 PMCID: PMC11339726 DOI: 10.1021/acs.analchem.4c02051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/26/2024] [Accepted: 07/26/2024] [Indexed: 08/21/2024]
Abstract
Here, we present a high-throughput virtual top-down proteomics approach that restores the molecular weight (MW) information in shotgun proteomics and demonstrates its utility in studying proteolytic events in programmed cell death. With gel-assisted proteome position integral shift (GAPPIS), we quantified over 7000 proteins in staurosporine-induced apoptotic HeLa cells and identified 84 proteins exhibiting in a statistically significant manner at least two of the following features: (i) a negative MW shift; (ii) an elevated ratio in a pair of a semitryptic and tryptic peptide, (iii) a negative shift in the standard deviation of MW estimated for different peptides, and (iv) a negative shift in skewness of the same data. Of these proteins, 58 molecules were previously unreported caspase 3 substrates. Further analysis identified the preferred cleavage sites consistent with the known caspase cleavages after the DXXD motif. As a powerful tool for high-throughput MW analysis simultaneously with the conventional expression analysis, the GAPPIS assay can prove useful in studying a broad range of biological processes involving proteolytic events.
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Affiliation(s)
- Zhaowei Meng
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics Unit, Science for Life Laboratory
(SciLifeLab), Stockholm 17165, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
| | - Amir Ata Saei
- Department
of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Hassan Gharibi
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics Unit, Science for Life Laboratory
(SciLifeLab), Stockholm 17165, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
| | - Xuepei Zhang
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics Unit, Science for Life Laboratory
(SciLifeLab), Stockholm 17165, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
| | - Hezheng Lyu
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- HDXperts
AB, Danderyd 18212, Sweden
| | - Susanna L. Lundström
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics Unit, Science for Life Laboratory
(SciLifeLab), Stockholm 17165, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
| | - Ákos Végvári
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | - Massimiliano Gaetani
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics Unit, Science for Life Laboratory
(SciLifeLab), Stockholm 17165, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
| | - Roman A. Zubarev
- Division
of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
- Chemical
Proteomics, Swedish National Infrastructure
for Biological Mass Spectrometry (BioMS), Stockholm 17177, Sweden
- The National
Medical Research Center for Endocrinology, Moscow 115478, Russia
- Department
of Pharmacological & Technological Chemistry, I.M. Sechenov First Moscow State Medical University, Moscow 119048, Russia
- Department
of Pharmaceutical and Toxicological Chemistry, RUDN University, 6 Miklukho-Maklaya
St., Moscow 117198, Russia
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2
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Alshehabi Y, Martin DDO. Protective Proteolysis in Huntington's Disease: Unraveling the Role of Post-Translational Myristoylation of Huntingtin in Autophagy. J Huntingtons Dis 2024:JHD240028. [PMID: 38995796 DOI: 10.3233/jhd-240028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder characterized by impaired motor function and cognitive decline, ultimately leading to death. HD is caused by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein, which is linked to decreased HTT turnover, increased HTT proteolysis, increased HTT aggregation, and subsequent neuronal death. In this review, we explore the mechanism of the protective effect of blocking HTT proteolysis at D586, which has been shown to rescue the HD phenotype in HD mouse models. Until recently, the mechanism remained unclear. Herein, we discuss how blocking HTT proteolysis at D586 promotes HTT turnover by correcting autophagy, and making HTT a better autophagy substrate, through post-translational myristoylation of HTT at G553.
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Affiliation(s)
- Yasmeen Alshehabi
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Dale D O Martin
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
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3
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Shirguppe S, Gapinske M, Swami D, Gosstola N, Acharya P, Miskalis A, Joulani D, Szkwarek MG, Bhattacharjee A, Elias G, Stilger M, Winter J, Woods WS, Anand D, Lim CKW, Gaj T, Perez-Pinera P. In vivo CRISPR base editing for treatment of Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602282. [PMID: 39005280 PMCID: PMC11245100 DOI: 10.1101/2024.07.05.602282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Huntington's disease (HD) is an inherited and ultimately fatal neurodegenerative disorder caused by an expanded polyglutamine-encoding CAG repeat within exon 1 of the huntingtin (HTT) gene, which produces a mutant protein that destroys striatal and cortical neurons. Importantly, a critical event in the pathogenesis of HD is the proteolytic cleavage of the mutant HTT protein by caspase-6, which generates fragments of the N-terminal domain of the protein that form highly toxic aggregates. Given the role that proteolysis of the mutant HTT protein plays in HD, strategies for preventing this process hold potential for treating the disorder. By screening 141 CRISPR base editor variants targeting splice elements in the HTT gene, we identified platforms capable of producing HTT protein isoforms resistant to caspase-6-mediated proteolysis via editing of the splice acceptor sequence for exon 13. When delivered to the striatum of a rodent HD model, these base editors induced efficient exon skipping and decreased the formation of the N-terminal fragments, which in turn reduced HTT protein aggregation and attenuated striatal and cortical atrophy. Collectively, these results illustrate the potential for CRISPR base editing to decrease the toxicity of the mutant HTT protein for HD.
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4
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Wang JY, Liu YJ, Zhang XL, Liu YH, Jiang LL, Hu HY. PolyQ-expanded ataxin-2 aggregation impairs cellular processing-body homeostasis via sequestering the RNA helicase DDX6. J Biol Chem 2024; 300:107413. [PMID: 38810698 PMCID: PMC11254730 DOI: 10.1016/j.jbc.2024.107413] [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] [Received: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 05/31/2024] Open
Abstract
Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.
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Affiliation(s)
- Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Yin-Hu Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, PR China.
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5
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Bhat MA, Dhaneshwar S. Neurodegenerative Diseases: New Hopes and Perspectives. Curr Mol Med 2024; 24:1004-1032. [PMID: 37691199 DOI: 10.2174/1566524023666230907093451] [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] [Received: 05/29/2023] [Revised: 07/10/2023] [Accepted: 07/27/2023] [Indexed: 09/12/2023]
Abstract
Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, Huntington's disease, and Friedrich ataxia are all incurable neurodegenerative diseases defined by the continuous progressive loss of distinct neuronal subtypes. Despite their rising prevalence among the world's ageing population, fewer advances have been made in the concurrent massive efforts to develop newer drugs. Recently, there has been a shift in research focus towards the discovery of new therapeutic agents for neurodegenerative diseases. In this review, we have summarized the recently developed therapies and their status in the management of neurodegenerative diseases.
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Affiliation(s)
- Mohammad Aadil Bhat
- Amity Institute of Pharmacy, Lucknow, Amity University Uttar Pradesh, Noida, UP, India
| | - Suneela Dhaneshwar
- Amity Institute of Pharmacy, Amity University Maharashtra, Mumbai, Maharashtra, India
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6
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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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7
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Tassone A, Meringolo M, Ponterio G, Bonsi P, Schirinzi T, Martella G. Mitochondrial Bioenergy in Neurodegenerative Disease: Huntington and Parkinson. Int J Mol Sci 2023; 24:ijms24087221. [PMID: 37108382 PMCID: PMC10138549 DOI: 10.3390/ijms24087221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Strong evidence suggests a correlation between degeneration and mitochondrial deficiency. Typical cases of degeneration can be observed in physiological phenomena (i.e., ageing) as well as in neurological neurodegenerative diseases and cancer. All these pathologies have the dyshomeostasis of mitochondrial bioenergy as a common denominator. Neurodegenerative diseases show bioenergetic imbalances in their pathogenesis or progression. Huntington's chorea and Parkinson's disease are both neurodegenerative diseases, but while Huntington's disease is genetic and progressive with early manifestation and severe penetrance, Parkinson's disease is a pathology with multifactorial aspects. Indeed, there are different types of Parkinson/Parkinsonism. Many forms are early-onset diseases linked to gene mutations, while others could be idiopathic, appear in young adults, or be post-injury senescence conditions. Although Huntington's is defined as a hyperkinetic disorder, Parkinson's is a hypokinetic disorder. However, they both share a lot of similarities, such as neuronal excitability, the loss of striatal function, psychiatric comorbidity, etc. In this review, we will describe the start and development of both diseases in relation to mitochondrial dysfunction. These dysfunctions act on energy metabolism and reduce the vitality of neurons in many different brain areas.
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Affiliation(s)
- Annalisa Tassone
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Saint Camillus International University of Health and Medical Sciences, 00131 Rome, Italy
| | - Giulia Ponterio
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Tommaso Schirinzi
- Unit of Neurology, Department of Systems Medicine, Tor Vergata University of Rome, 00133 Rome, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
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8
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Tshilenge KT, Aguirre CG, Bons J, Gerencser AA, Basisty N, Song S, Rose J, Lopez-Ramirez A, Naphade S, Loureiro A, Battistoni E, Milani M, Wehrfritz C, Holtz A, Hetz C, Mooney SD, Schilling B, Ellerby LM. Proteomic Analysis of Huntington's Disease Medium Spiny Neurons Identifies Alterations in Lipid Droplets. Mol Cell Proteomics 2023; 22:100534. [PMID: 36958627 PMCID: PMC10165459 DOI: 10.1016/j.mcpro.2023.100534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 03/15/2023] [Accepted: 03/19/2023] [Indexed: 03/25/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease caused by a CAG repeat expansion in the Huntingtin (HTT) gene. The resulting polyglutamine (polyQ) tract alters the function of the HTT protein. Although HTT is expressed in different tissues, the medium spiny projection neurons (MSNs) in the striatum are particularly vulnerable in HD. Thus, we sought to define the proteome of human HD patient-derived MSNs. We differentiated HD72 induced pluripotent stem cells and isogenic controls into MSNs and carried out quantitative proteomic analysis. Using data-dependent acquisitions with FAIMS for label-free quantification on the Orbitrap Lumos mass spectrometer, we identified 6,323 proteins with at least two unique peptides. Of these, 901 proteins were altered significantly more in the HD72-MSNs than in isogenic controls. Functional enrichment analysis of upregulated proteins demonstrated extracellular matrix and DNA signaling (DNA replication pathway, double-strand break repair, G1/S transition) with the highest significance. Conversely, processes associated with the downregulated proteins included neurogenesis-axogenesis, the brain-derived neurotrophic factor-signaling pathway, Ephrin-A: EphA pathway, regulation of synaptic plasticity, triglyceride homeostasis cholesterol, plasmid lipoprotein particle immune response, interferon-γ signaling, immune system major histocompatibility complex, lipid metabolism and cellular response to stimulus. Moreover, proteins involved in the formation and maintenance of axons, dendrites, and synapses (e.g., Septin protein members) were dysregulated in HD72-MSNs. Importantly, lipid metabolism pathways were altered, and using quantitative image, we found analysis that lipid droplets accumulated in the HD72-MSN, suggesting a deficit in the turnover of lipids possibly through lipophagy. Our proteomics analysis of HD72-MSNs identified relevant pathways that are altered in MSNs and confirm current and new therapeutic targets for HD.
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Affiliation(s)
| | - Carlos Galicia Aguirre
- The Buck Institute for Research on Aging, Novato, California, 94945, USA; University of Southern California, Leonard Davis School of Gerontology, 3715 McClintock Ave, Los Angeles, CA 90893, USA
| | - Joanna Bons
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Akos A Gerencser
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Nathan Basisty
- The Buck Institute for Research on Aging, Novato, California, 94945, USA; Translational Gerontology Branch, National Institute on Aging (NIA), NIH, Baltimore, Maryland, 21244, USA
| | - Sicheng Song
- Department of Biomedical Informatics and Medical Education, School of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Jacob Rose
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | | | - Swati Naphade
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Ashley Loureiro
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Elena Battistoni
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Mateus Milani
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile; Center for Geroscience, Brain Health and Metabolism (GERO), Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile
| | - Cameron Wehrfritz
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Anja Holtz
- The Buck Institute for Research on Aging, Novato, California, 94945, USA
| | - Claudio Hetz
- The Buck Institute for Research on Aging, Novato, California, 94945, USA; Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile; Center for Geroscience, Brain Health and Metabolism (GERO), Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile
| | - Sean D Mooney
- Department of Biomedical Informatics and Medical Education, School of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Birgit Schilling
- The Buck Institute for Research on Aging, Novato, California, 94945, USA; University of Southern California, Leonard Davis School of Gerontology, 3715 McClintock Ave, Los Angeles, CA 90893, USA.
| | - Lisa M Ellerby
- The Buck Institute for Research on Aging, Novato, California, 94945, USA; University of Southern California, Leonard Davis School of Gerontology, 3715 McClintock Ave, Los Angeles, CA 90893, USA.
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9
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Lemarié FL, Sanders SS, Nguyen Y, Martin DDO, Hayden MR. Full-length huntingtin is palmitoylated at multiple sites and post-translationally myristoylated following caspase-cleavage. Front Physiol 2023; 14:1086112. [PMID: 36711022 PMCID: PMC9880554 DOI: 10.3389/fphys.2023.1086112] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Introduction: Huntington disease is an autosomal dominant neurodegenerative disorder which is caused by a CAG repeat expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. Huntingtin is subjected to multiple post-translational modifications which regulate its cellular functions and degradation. We have previously identified a palmitoylation site at cysteine 214 (C214), catalyzed by the enzymes ZDHHC17 and ZDHHC13. Reduced palmitoylation level of mutant huntingtin is linked to toxicity and loss of function. Moreover, we have described N-terminal myristoylation by the N-myristoyltransferases of a short fragment of huntingtin (HTT553-586) at glycine 553 (G553) following proteolysis at aspartate 552 (D552). Results: Here, we show that huntingtin is palmitoylated at numerous cysteines: C105, C433, C3134 and C3144. In addition, we confirm that full-length huntingtin is cleaved at D552 and post-translationally myristoylated at G553. Importantly, blocking caspase cleavage at the critical and pathogenic aspartate 586 (D586) significantly increases posttranslational myristoylation of huntingtin. In turn, myristoylation of huntingtin promotes the co-interaction between C-terminal and N-terminal huntingtin fragments, which is also protective. Discussion: This suggests that the protective effect of inhibiting caspase-cleavage at D586 may be mediated through post-translational myristoylation of huntingtin at G553.
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10
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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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11
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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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12
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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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13
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Mata-Martínez E, Díaz-Muñoz M, Vázquez-Cuevas FG. Glial Cells and Brain Diseases: Inflammasomes as Relevant Pathological Entities. Front Cell Neurosci 2022; 16:929529. [PMID: 35783102 PMCID: PMC9243488 DOI: 10.3389/fncel.2022.929529] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 12/13/2022] Open
Abstract
Inflammation mediated by the innate immune system is a physiopathological response to diverse detrimental circumstances such as microbe infections or tissular damage. The molecular events that underlie this response involve the assembly of multiprotein complexes known as inflammasomes. These assemblages are essentially formed by a stressor-sensing protein, an adapter protein and a non-apoptotic caspase (1 or 11). The coordinated aggregation of these components mediates the processing and release of pro-inflammatory interleukins (IL-β and IL-18) and cellular death by pyroptosis induction. The inflammatory response is essential for the defense of the organism; for example, it triggers tissue repair and the destruction of pathogen microbe infections. However, when inflammation is activated chronically, it promotes diverse pathologies in the lung, liver, brain and other organs. The nervous system is one of the main tissues where the inflammatory process has been characterized, and its implications in health and disease are starting to be understood. Thus, the regulation of inflammasomes in specific cellular types of the central nervous system needs to be thoroughly understood to innovate treatments for diverse pathologies. In this review, the presence and participation of inflammasomes in pathological conditions in different types of glial cells will be discussed.
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14
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Weber JJ, Anger SC, Pereira Sena P, Incebacak Eltemur RD, Huridou C, Fath F, Gross C, Casadei N, Riess O, Nguyen HP. Calpains as novel players in the molecular pathogenesis of spinocerebellar ataxia type 17. Cell Mol Life Sci 2022; 79:262. [PMID: 35482253 PMCID: PMC9050766 DOI: 10.1007/s00018-022-04274-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 03/07/2022] [Accepted: 03/25/2022] [Indexed: 11/23/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is a neurodegenerative disease caused by a polyglutamine-encoding trinucleotide repeat expansion in the gene of transcription factor TATA box-binding protein (TBP). While its underlying pathomechanism is elusive, polyglutamine-expanded TBP fragments of unknown origin mediate the mutant protein’s toxicity. Calcium-dependent calpain proteases are protagonists in neurodegenerative disorders. Here, we demonstrate that calpains cleave TBP, and emerging C-terminal fragments mislocalize to the cytoplasm. SCA17 cell and rat models exhibited calpain overactivation, leading to excessive fragmentation and depletion of neuronal proteins in vivo. Transcriptome analysis of SCA17 cells revealed synaptogenesis and calcium signaling perturbations, indicating the potential cause of elevated calpain activity. Pharmacological or genetic calpain inhibition reduced TBP cleavage and aggregation, consequently improving cell viability. Our work underlines the general significance of calpains and their activating pathways in neurodegenerative disorders and presents these proteases as novel players in the molecular pathogenesis of SCA17.
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Affiliation(s)
- Jonasz Jeremiasz Weber
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Stefanie Cari Anger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Priscila Pereira Sena
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,Graduate School of Cellular Neuroscience, University of Tübingen, 72074, Tübingen, Germany
| | - Rana Dilara Incebacak Eltemur
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Chrisovalantou Huridou
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Florian Fath
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany
| | - Caspar Gross
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076, Tübingen, Germany.,NGS Competence Center Tübingen, 72076, Tübingen, Germany
| | - Huu Phuc Nguyen
- Department of Human Genetics, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
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15
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Chen KP, Hua KF, Tsai FT, Lin TY, Cheng CY, Yang DI, Hsu HT, Ju TC. A selective inhibitor of the NLRP3 inflammasome as a potential therapeutic approach for neuroprotection in a transgenic mouse model of Huntington’s disease. J Neuroinflammation 2022; 19:56. [PMID: 35219323 PMCID: PMC8882273 DOI: 10.1186/s12974-022-02419-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 02/21/2022] [Indexed: 12/11/2022] Open
Abstract
Background Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of the CAG repeat in the huntingtin (HTT) gene. When the number of CAG repeats exceeds 36, the translated expanded polyglutamine-containing HTT protein (mutant HTT [mHTT]) interferes with the normal functions of many cellular proteins and subsequently jeopardizes important cellular machineries in major types of brain cells, including neurons, astrocytes, and microglia. The NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome, which comprises NLRP3, ASC, and caspase-1, is involved in the activation of IL-1β and IL-18 and has been implicated in various biological functions. Although the existence of the NLRP3 inflammasome in the brain has been documented, the roles of the NLRP3 inflammasome in HD remain largely uncharacterized. MCC950 is a highly selective and potent small-molecule inhibitor of NLRP3 that has been used for the treatment of several diseases such as Alzheimer’s disease. However, whether MCC950 is also beneficial in HD remains unknown. Therefore, we hypothesized that MCC950 exerts beneficial effects in a transgenic mouse model of HD. Methods To evaluate the effects of MCC950 in HD, we used the R6/2 (B6CBA-Tg[HDexon1]62Gpb/1J) transgenic mouse model of HD, which expresses exon 1 of the human HTT gene carrying 120 ± 5 CAG repeats. Male transgenic R6/2 mice were treated daily with MCC950 (10 mg/kg of body weight; oral administration) or water for 5 weeks from the age of 7 weeks. We examined neuronal density, neuroinflammation, and mHTT aggregation in the striatum of R6/2 mice vs. their wild-type littermates. We also evaluated the motor function, body weight, and lifespan of R6/2 mice. Results Systematic administration of MCC950 to R6/2 mice suppressed the NLRP3 inflammasome, decreased IL-1β and reactive oxygen species production, and reduced neuronal toxicity, as assessed based on increased neuronal density and upregulation of the NeuN and PSD-95 proteins. Most importantly, oral administration of MCC950 increased neuronal survival, reduced neuroinflammation, extended lifespan, and improved motor dysfunction in R6/2 mice. Conclusions Collectively, our findings indicate that MCC950 exerts beneficial effects in a transgenic mouse model of HD and has therapeutic potential for treatment of this devastating neurodegenerative disease. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02419-9.
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Elsadany M, Elghaish RA, Khalil AS, Ahmed AS, Mansour RH, Badr E, Elserafy M. Transcriptional Analysis of Nuclear-Encoded Mitochondrial Genes in Eight Neurodegenerative Disorders: The Analysis of Seven Diseases in Reference to Friedreich’s Ataxia. Front Genet 2021; 12:749792. [PMID: 34987545 PMCID: PMC8721009 DOI: 10.3389/fgene.2021.749792] [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: 07/30/2021] [Accepted: 10/20/2021] [Indexed: 11/25/2022] Open
Abstract
Neurodegenerative diseases (NDDs) are challenging to understand, diagnose, and treat. Revealing the genomic and transcriptomic changes in NDDs contributes greatly to the understanding of the diseases, their causes, and development. Moreover, it enables more precise genetic diagnosis and novel drug target identification that could potentially treat the diseases or at least ease the symptoms. In this study, we analyzed the transcriptional changes of nuclear-encoded mitochondrial (NEM) genes in eight NDDs to specifically address the association of these genes with the diseases. Previous studies show strong links between defects in NEM genes and neurodegeneration, yet connecting specific genes with NDDs is not well studied. Friedreich’s ataxia (FRDA) is an NDD that cannot be treated effectively; therefore, we focused first on FRDA and compared the outcome with seven other NDDs, including Alzheimer’s disease, amyotrophic lateral sclerosis, Creutzfeldt–Jakob disease, frontotemporal dementia, Huntington’s disease, multiple sclerosis, and Parkinson’s disease. First, weighted correlation network analysis was performed on an FRDA RNA-Seq data set, focusing only on NEM genes. We then carried out differential gene expression analysis and pathway enrichment analysis to pinpoint differentially expressed genes that are potentially associated with one or more of the analyzed NDDs. Our findings propose a strong link between NEM genes and NDDs and suggest that our identified candidate genes can be potentially used as diagnostic markers and therapeutic targets.
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Affiliation(s)
- Muhammad Elsadany
- University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Reem A. Elghaish
- University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Aya S. Khalil
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Alaa S. Ahmed
- University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Rana H. Mansour
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Eman Badr
- University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Faculty of Computers and Artificial Intelligence, Cairo University, Giza, Egypt
- *Correspondence: Eman Badr, ; Menattallah Elserafy,
| | - Menattallah Elserafy
- University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- *Correspondence: Eman Badr, ; Menattallah Elserafy,
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17
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Pasha T, Zatorska A, Sharipov D, Rogelj B, Hortobágyi T, Hirth F. Karyopherin abnormalities in neurodegenerative proteinopathies. Brain 2021; 144:2915-2932. [PMID: 34019093 PMCID: PMC8194669 DOI: 10.1093/brain/awab201] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 04/08/2021] [Accepted: 05/11/2021] [Indexed: 11/12/2022] Open
Abstract
Neurodegenerative proteinopathies are characterized by progressive cell loss that is preceded by the mislocalization and aberrant accumulation of proteins prone to aggregation. Despite their different physiological functions, disease-related proteins like tau, α-synuclein, TAR DNA binding protein-43, fused in sarcoma and mutant huntingtin, all share low complexity regions that can mediate their liquid-liquid phase transitions. The proteins' phase transitions can range from native monomers to soluble oligomers, liquid droplets and further to irreversible, often-mislocalized aggregates that characterize the stages and severity of neurodegenerative diseases. Recent advances into the underlying pathogenic mechanisms have associated mislocalization and aberrant accumulation of disease-related proteins with defective nucleocytoplasmic transport and its mediators called karyopherins. These studies identify karyopherin abnormalities in amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's disease, and synucleinopathies including Parkinson's disease and dementia with Lewy bodies, that range from altered expression levels to the subcellular mislocalization and aggregation of karyopherin α and β proteins. The reported findings reveal that in addition to their classical function in nuclear import and export, karyopherins can also act as chaperones by shielding aggregation-prone proteins against misfolding, accumulation and irreversible phase-transition into insoluble aggregates. Karyopherin abnormalities can, therefore, be both the cause and consequence of protein mislocalization and aggregate formation in degenerative proteinopathies. The resulting vicious feedback cycle of karyopherin pathology and proteinopathy identifies karyopherin abnormalities as a common denominator of onset and progression of neurodegenerative disease. Pharmacological targeting of karyopherins, already in clinical trials as therapeutic intervention targeting cancers such as glioblastoma and viral infections like COVID-19, may therefore represent a promising new avenue for disease-modifying treatments in neurodegenerative proteinopathies.
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Affiliation(s)
- Terouz Pasha
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Anna Zatorska
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Daulet Sharipov
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Boris Rogelj
- Jozef Stefan Institute, Department of Biotechnology, 1000 Ljubljana, Slovenia
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, 1000 Ljubljana, Slovenia
| | - Tibor Hortobágyi
- ELKH-DE Cerebrovascular and Neurodegenerative Research Group, Department of Neurology, University of Debrecen, 4032 Debrecen, Hungary
- King's College London, Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, London SE5 8AF, UK
| | - Frank Hirth
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
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Vieweg S, Mahul-Mellier AL, Ruggeri FS, Riguet N, DeGuire SM, Chiki A, Cendrowska U, Dietler G, Lashuel HA. The Nt17 Domain and its Helical Conformation Regulate the Aggregation, Cellular Properties and Neurotoxicity of Mutant Huntingtin Exon 1. J Mol Biol 2021; 433:167222. [PMID: 34492254 DOI: 10.1016/j.jmb.2021.167222] [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: 05/12/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022]
Abstract
Converging evidence points to the N-terminal domain comprising the first 17 amino acids of the Huntingtin protein (Nt17) as a key regulator of its aggregation, cellular properties and toxicity. In this study, we further investigated the interplay between Nt17 and the polyQ domain repeat length in regulating the aggregation and inclusion formation of exon 1 of the Huntingtin protein (Httex1). In addition, we investigated the effect of removing Nt17 or modulating its local structure on the membrane interactions, neuronal uptake, and toxicity of monomeric or fibrillar Httex1. Our results show that the polyQ and Nt17 domains synergistically modulate the aggregation propensity of Httex1 and that the Nt17 domain plays important roles in shaping the surface properties of mutant Httex1 fibrils and regulating their poly-Q-dependent growth, lateral association and neuronal uptake. Removal of Nt17 or disruption of its transient helical conformations slowed the aggregation of monomeric Httex1 in vitro, reduced inclusion formation in cells, enhanced the neuronal uptake and nuclear accumulation of monomeric Httex1 proteins, and was sufficient to prevent cell death induced by Httex1 72Q overexpression. Finally, we demonstrate that the uptake of Httex1 fibrils into primary neurons and the resulting toxicity are strongly influenced by mutations and phosphorylation events that influence the local helical propensity of Nt17. Altogether, our results demonstrate that the Nt17 domain serves as one of the key master regulators of Htt aggregation, internalization, and toxicity and represents an attractive target for inhibiting Htt aggregate formation, inclusion formation, and neuronal toxicity.
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Affiliation(s)
- Sophie Vieweg
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Anne-Laure Mahul-Mellier
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Francesco S Ruggeri
- Laboratory of the Physics of Living Matter, EPFL, 1015 Lausanne, Switzerland
| | - Nathan Riguet
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Sean M DeGuire
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Anass Chiki
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Urszula Cendrowska
- Laboratory of the Physics of Living Matter, EPFL, 1015 Lausanne, Switzerland
| | - Giovanni Dietler
- Laboratory of the Physics of Living Matter, EPFL, 1015 Lausanne, Switzerland
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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19
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Simões AT, Carmona V, Duarte-Neves J, Cunha-Santos J, Pereira de Almeida L. Identification of the calpain-generated toxic fragment of ataxin-3 protein provides new avenues for therapy of Machado-Joseph disease| Spinocerebellar ataxia type 3. Neuropathol Appl Neurobiol 2021; 48:e12748. [PMID: 34273111 DOI: 10.1111/nan.12748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 06/26/2021] [Accepted: 07/11/2021] [Indexed: 12/14/2022]
Abstract
AIMS Machado-Joseph disease (MJD) is the most frequent dominantly inherited cerebellar ataxia worldwide. Expansion of a CAG trinucleotide in the MJD1 gene translates into a polyglutamine tract within ataxin-3, which upon proteolysis may lead to MJD. The aim of this work was to understand the in vivo contribution of calpain proteases to the pathogenesis of MJD. Therefore, we investigated (a) the calpain cleavage sites in ataxin-3 protein, (b) the most toxic ataxin-3 fragment generated by calpain cleavage and (c) whether targeting calpain cleavage sites of mutant ataxin-3 could be a therapeutic strategy for MJD. METHODS We generated truncated and calpain-resistant constructs at the predicted cleavage sites of ataxin-3 using inverse PCR mutagenesis. Lentiviral vectors encoding these constructs were transduced in the adult mouse brain prior to western blot and immunohistochemical analysis 5 and 8 weeks later. RESULTS We identified the putative calpain cleavage sites for both wild-type and mutant ataxin-3 proteins. The mutation of these sites eliminated the formation of the toxic fragments, namely, the 26-kDa fragment, the major contributor for striatal degeneration. Nonetheless, reducing the formation of both the 26- and 34-kDa fragments was required to preclude the intranuclear localisation of ataxin-3. A neuroprotective effect was observed upon mutagenesis of calpain cleavage sites within mutant ataxin-3 protein. CONCLUSIONS These findings suggest that the calpain system should be considered a target for MJD therapy. The identified calpain cleavage sites will contribute to the design of targeted drugs and genome editing systems for those specific locations.
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Affiliation(s)
- Ana Teresa Simões
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Vítor Carmona
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Joana Duarte-Neves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Janete Cunha-Santos
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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20
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Temussi PA, Tartaglia GG, Pastore A. The seesaw between normal function and protein aggregation: How functional interactions may increase protein solubility. Bioessays 2021; 43:e2100031. [PMID: 33783021 DOI: 10.1002/bies.202100031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation has been studied for at least 3 decades, and many of the principles that regulate this event are relatively well understood. Here, however, we present a different perspective to explain why proteins aggregate: we argue that aggregation may occur as a side-effect of the lack of one or more natural partners that, under physiologic conditions, would act as chaperones. This would explain why the same surfaces that have evolved for functional purposes are also those that favour aggregation. In the course of reviewing this field, we substantiate our hypothesis with three paradigmatic examples that argue for the generality of our proposal. An obvious corollary of this hypothesis is, of course, that targeting the physiological partners of a protein could be the most direct and specific approach to designing anti-aggregation molecules. Our analysis may thus inform a different strategy for combating diseases of protein aggregation and misfolding.
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Affiliation(s)
- Piero Andrea Temussi
- UK Dementia Research Institute at King's College London, The Maurice Wohl Institute, London, UK
| | - Gian Gaetano Tartaglia
- Center for Human Technologies, Central RNA laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Charles Darwin Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Annalisa Pastore
- UK Dementia Research Institute at King's College London, The Maurice Wohl Institute, London, UK
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21
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Duez H, Pourcet B. Nuclear Receptors in the Control of the NLRP3 Inflammasome Pathway. Front Endocrinol (Lausanne) 2021; 12:630536. [PMID: 33716981 PMCID: PMC7947301 DOI: 10.3389/fendo.2021.630536] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/04/2021] [Indexed: 12/13/2022] Open
Abstract
The innate immune system is the first line of defense specialized in the clearing of invaders whether foreign elements like microbes or self-elements that accumulate abnormally including cellular debris. Inflammasomes are master regulators of the innate immune system, especially in macrophages, and are key sensors involved in maintaining cellular health in response to cytolytic pathogens or stress signals. Inflammasomes are cytoplasmic complexes typically composed of a sensor molecule such as NOD-Like Receptors (NLRs), an adaptor protein including ASC and an effector protein such as caspase 1. Upon stimulation, inflammasome complex components associate to promote the cleavage of the pro-caspase 1 into active caspase-1 and the subsequent activation of pro-inflammatory cytokines including IL-18 and IL-1β. Deficiency or overactivation of such important sensors leads to critical diseases including Alzheimer diseases, chronic inflammatory diseases, cancers, acute liver diseases, and cardiometabolic diseases. Inflammasomes are tightly controlled by a two-step activation regulatory process consisting in a priming step, which activates the transcription of inflammasome components, and an activation step which leads to the inflammasome complex formation and the subsequent cleavage of pro-IL1 cytokines. Apart from the NF-κB pathway, nuclear receptors have recently been proposed as additional regulators of this pathway. This review will discuss the role of nuclear receptors in the control of the NLRP3 inflammasome and the putative beneficial effect of new modulators of inflammasomes in the treatment of inflammatory diseases including colitis, fulminant hepatitis, cardiac ischemia-reperfusion and brain diseases.
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22
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Chiu YJ, Lin SA, Chen WL, Lin TH, Lin CH, Yao CF, Lin W, Wu YR, Chang KH, Lee-Chen GJ, Chen CM. Pathomechanism characterization and potential therapeutics identification for SCA3 targeting neuroinflammation. Aging (Albany NY) 2020; 12:23619-23646. [PMID: 33196459 PMCID: PMC7762503 DOI: 10.18632/aging.103700] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 06/29/2020] [Indexed: 12/12/2022]
Abstract
Polyglutamine (polyQ)-mediated spinocerebellar ataxias (SCA) are caused by mutant genes with expanded CAG repeats encoding polyQ tracts. The misfolding and aggregation of polyQ proteins result in increased reactive oxygen species (ROS) and cellular toxicity. Inflammation is a common manifestation of oxidative stress and inflammatory process further reduces cellular antioxidant capacity. Increase of activated microglia in the pons of SCA type 3 (SCA3) patients suggests the involvement of neuroinflammation in the disease pathogenesis. In this study, we evaluated the anti-inflammatory potentials of indole compound NC009-1, 4-aminophenol-arachidonic acid derivative AM404, quinoline compound VB-037 and chalcone-coumarin derivative LM-031 using human HMC3 microglia and SCA3 ATXN3/Q75-GFP SH-SY5Y cells. The four tested compounds displayed anti-inflammatory activity by suppressing NO, IL-1β, TNF-α and IL-6 production and CD68 expression of IFN-γ-activated HMC3 microglia. In retinoic acid-differentiated ATXN3/Q75-GFP SH-SY5Y cells inflamed with IFN-γ-primed HMC3 conditioned medium, treatment with the tested compounds mitigated the increased caspase 1 activity and lactate dehydrogenase release, reduced polyQ aggregation and ROS and/or promoted neurite outgrowth. Examination of IL-1β- and TNF-α-mediated signaling pathways revealed that the tested compounds decreased IκBα/P65, JNK/JUN and/or P38/STAT1 signaling. The study results suggest the potential of NC009-1, AM404, VB-037 and LM-031 in treating SCA3 and probable other polyQ diseases.
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Affiliation(s)
- Ya-Jen Chiu
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Shu-An Lin
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Wan-Ling Chen
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Te-Hsien Lin
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Chih-Hsin Lin
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Ching-Fa Yao
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Wenwei Lin
- Department of Chemistry, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Yih-Ru Wu
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Kuo-Hsuan Chang
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
| | - Guey-Jen Lee-Chen
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Chiung-Mei Chen
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 33302, Taiwan
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23
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Van Pelt KM, Truttmann MC. Caenorhabditis elegans as a model system for studying aging-associated neurodegenerative diseases. TRANSLATIONAL MEDICINE OF AGING 2020; 4:60-72. [PMID: 34327290 PMCID: PMC8317484 DOI: 10.1016/j.tma.2020.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative diseases (NDs) are a heterogeneous group of aging-associated disorders characterized by the disruption of cellular proteostasis machinery and the misfolding of distinct protein species to form toxic aggregates in neurons. The increasing prevalence of NDs represents a growing healthcare burden worldwide, a concern compounded by the fact that few, if any, treatments exist to target the underlying cause of these diseases. Consequently, the application of a high-throughput, physiologically relevant model system to studies dissecting the molecular mechanisms governing ND pathology is crucial for identifying novel avenues for the development of targeted therapeutics. The nematode Caenorhabditis elegans (C. elegans) has emerged as a powerful tool for the study of disease mechanisms due to its ease of genetic manipulation and swift cultivation, while providing a whole-animal system amendable to numerous molecular and biochemical techniques. To date, numerous C. elegans models have been generated for a variety of NDs, allowing for the large-scale in vivo study of protein-conformation disorders. Furthermore, the comparatively low barriers to entry in the development of transgenic worm models have facilitated the modeling of rare or "orphan" NDs, thereby providing unparalleled insight into the shared mechanisms underlying these pathologies. In this review, we summarize findings from a comprehensive collection of C. elegans neurodegenerative disease models of varying prevalence to emphasize shared mechanisms of proteotoxicity, and highlight the utility of these models in elucidating the molecular basis of ND pathologies.
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Affiliation(s)
- Kate M. Van Pelt
- Cellular & Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Matthias C. Truttmann
- Cellular & Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
- Geriatrics Center, University of Michigan, Ann Arbor, MI, 48109, USA
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24
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Voet S, Srinivasan S, Lamkanfi M, van Loo G. Inflammasomes in neuroinflammatory and neurodegenerative diseases. EMBO Mol Med 2020; 11:emmm.201810248. [PMID: 31015277 PMCID: PMC6554670 DOI: 10.15252/emmm.201810248] [Citation(s) in RCA: 436] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neuroinflammation and neurodegeneration often result from the aberrant deposition of aggregated host proteins, including amyloid‐β, α‐synuclein, and prions, that can activate inflammasomes. Inflammasomes function as intracellular sensors of both microbial pathogens and foreign as well as host‐derived danger signals. Upon activation, they induce an innate immune response by secreting the inflammatory cytokines interleukin (IL)‐1β and IL‐18, and additionally by inducing pyroptosis, a lytic cell death mode that releases additional inflammatory mediators. Microglia are the prominent innate immune cells in the brain for inflammasome activation. However, additional CNS‐resident cell types including astrocytes and neurons, as well as infiltrating myeloid cells from the periphery, express and activate inflammasomes. In this review, we will discuss current understanding of the role of inflammasomes in common degenerative diseases of the brain and highlight inflammasome‐targeted strategies that may potentially treat these diseases.
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Affiliation(s)
- Sofie Voet
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sahana Srinivasan
- VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Mohamed Lamkanfi
- Department of Internal Medicine, Ghent University, Ghent, Belgium .,Janssen Immunosciences, World without Disease Accelerator, Pharmaceutical Companies of Johnson & Johnson, Beerse, Belgium
| | - Geert van Loo
- VIB Center for Inflammation Research, Ghent, Belgium .,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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25
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Kumar A, Kumar V, Singh K, Kumar S, Kim YS, Lee YM, Kim JJ. Therapeutic Advances for Huntington's Disease. Brain Sci 2020; 10:brainsci10010043. [PMID: 31940909 PMCID: PMC7016861 DOI: 10.3390/brainsci10010043] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023] Open
Abstract
Huntington’s disease (HD) is a progressive neurological disease that is inherited in an autosomal fashion. The cause of disease pathology is an expansion of cytosine-adenine-guanine (CAG) repeats within the huntingtin gene (HTT) on chromosome 4 (4p16.3), which codes the huntingtin protein (mHTT). The common symptoms of HD include motor and cognitive impairment of psychiatric functions. Patients exhibit a representative phenotype of involuntary movement (chorea) of limbs, impaired cognition, and severe psychiatric disturbances (mood swings, depression, and personality changes). A variety of symptomatic treatments (which target glutamate and dopamine pathways, caspases, inhibition of aggregation, mitochondrial dysfunction, transcriptional dysregulation, and fetal neural transplants, etc.) are available and some are in the pipeline. Advancement in novel therapeutic approaches include targeting the mutant huntingtin (mHTT) protein and the HTT gene. New gene editing techniques will reduce the CAG repeats. More appropriate and readily tractable treatment goals, coupled with advances in analytical tools will help to assess the clinical outcomes of HD treatments. This will not only improve the quality of life and life span of HD patients, but it will also provide a beneficial role in other inherited and neurological disorders. In this review, we aim to discuss current therapeutic research approaches and their possible uses for HD.
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Affiliation(s)
- Ashok Kumar
- Department of Genetics, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow 226014, UP, India;
| | - Vijay Kumar
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
- Correspondence: (V.K.); (J.-J.K.)
| | - Kritanjali Singh
- Central Research Station, Subharti Medical College, Swami Vivekanand Subharti University, Meerut 250002, India;
| | - Sukesh Kumar
- PG Department of Botany, Nalanda College, Bihar Sharif, Magadh University, Bihar 824234, India;
| | - You-Sam Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
| | - Yun-Mi Lee
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
| | - Jong-Joo Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Korea; (Y.-S.K.); (Y.-M.L.)
- Correspondence: (V.K.); (J.-J.K.)
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26
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Mioduszewski Ł, Cieplak M. Protein droplets in systems of disordered homopeptides and the amyloid glass phase. Phys Chem Chem Phys 2020; 22:15592-15599. [DOI: 10.1039/d0cp01635g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We study phase diagrams and liquid droplet formation for systems of polyglutamine and polyalanine chains in a coarse-grained model.
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Affiliation(s)
| | - Marek Cieplak
- Institute of Physics
- Polish Academy of Sciences
- 02-668 Warsaw
- Poland
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27
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Affiliation(s)
- Lisa M Ellerby
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA.
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28
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Da Silva JD, Teixeira-Castro A, Maciel P. From Pathogenesis to Novel Therapeutics for Spinocerebellar Ataxia Type 3: Evading Potholes on the Way to Translation. Neurotherapeutics 2019; 16:1009-1031. [PMID: 31691128 PMCID: PMC6985322 DOI: 10.1007/s13311-019-00798-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD), is a neurodegenerative disorder caused by a polyglutamine expansion in the ATXN3 gene. In spite of the identification of a clear monogenic cause 25 years ago, the pathological process still puzzles researchers, impairing prospects for an effective therapy. Here, we propose the disruption of protein homeostasis as the hub of SCA3 pathogenesis, being the molecular mechanisms and cellular pathways that are deregulated in SCA3 downstream consequences of the misfolding and aggregation of ATXN3. Moreover, we attempt to provide a realistic perspective on how the translational/clinical research in SCA3 should evolve. This was based on molecular findings, clinical and epidemiological characteristics, studies of proposed treatments in other conditions, and how that information is essential for their (re-)application in SCA3. This review thus aims i) to critically evaluate the current state of research on SCA3, from fundamental to translational and clinical perspectives; ii) to bring up the current key questions that remain unanswered in this disorder; and iii) to provide a frame on how those answers should be pursued.
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Affiliation(s)
- Jorge Diogo Da Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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29
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Tao M, Pandey NK, Barnes R, Han S, Langen R. Structure of Membrane-Bound Huntingtin Exon 1 Reveals Membrane Interaction and Aggregation Mechanisms. Structure 2019; 27:1570-1580.e4. [PMID: 31466833 DOI: 10.1016/j.str.2019.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/23/2019] [Accepted: 08/09/2019] [Indexed: 02/08/2023]
Abstract
Huntington's disease is caused by a polyQ expansion in the first exon of huntingtin (Httex1). Membrane interaction of huntingtin is of physiological and pathological relevance. Using electron paramagnetic resonance and Overhauser dynamic nuclear polarization, we find that the N-terminal residues 3-13 of wild-type Httex1(Q25) form a membrane-bound, amphipathic α helix. This helix is positioned in the interfacial region, where it is sensitive to membrane curvature and electrostatic interactions with head-group charges. Residues 14-22, which contain the first five residues of the polyQ region, are in a transition region that remains in the interfacial region without taking up a stable, α-helical structure. The remaining C-terminal portion is solvent exposed. The phosphomimetic S13D/S16D mutations, which are known to protect from toxicity, inhibit membrane binding and attenuate membrane-mediated aggregation of mutant Httex1(Q46) due to electrostatic repulsion. Targeting the N-terminal membrane anchor using post-translational modifications or specific binders could be a potential means to reduce aggregation and toxicity in vivo.
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Affiliation(s)
- Meixin Tao
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Nitin K Pandey
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Ryan Barnes
- Department of Chemistry and Biochemistry, Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Songi Han
- Department of Chemistry and Biochemistry, Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ralf Langen
- Department of Neuroscience and Physiology, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
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30
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Liu P, Smith BR, Huang ES, Mahesh A, Vonsattel JPG, Petersen AJ, Gomez-Pastor R, Ashe KH. A soluble truncated tau species related to cognitive dysfunction and caspase-2 is elevated in the brain of Huntington's disease patients. Acta Neuropathol Commun 2019; 7:111. [PMID: 31358058 PMCID: PMC6664763 DOI: 10.1186/s40478-019-0764-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022] Open
Abstract
Huntington’s disease (HD) is a progressive neurodegenerative disease. Involuntary movements, cognitive impairment and psychiatric disturbance are the major clinical manifestations, and gradual atrophy and selective neuronal loss in the striatum and cerebral cortex are the pathologic hallmarks. HD is caused by expanded CAG trinucleotide repeats at the N-terminus of IT15 that encodes the huntingtin (HTT) protein, though the molecular mechanisms through which the mutant HTT (mHTT) exerts toxic effects remain obscure. Members of the caspase family, including caspase-2 (Casp2), play an important role in HD pathogenesis. Genetic ablation of Casp2 ameliorates cognitive and motor deficits of HD mice, though the molecular targets of Casp2 are still unclear. It is well established that the microtubule-associated protein tau potentiates cognitive dysfunction in a variety of neurodegenerative disorders, including HD. Our recent study indicates that Casp2-catalyzed tau cleavage at aspartate 314 (tau 2N4R isoform numbering system) mediates synaptotoxicity, cognitive deficits and neurodegeneration in cellular and mouse models of frontotemporal dementia; further, levels of Δtau314, the soluble, N-terminal cleavage product, are elevated in individuals with mild cognitive impairment and Alzheimer’s disease, compared with cognitively normal individuals. Here, we identified the presence of Δtau314 proteins in the striatum (caudate nucleus) and prefrontal cortex (Brodmann’s area 8/9) of human subjects, and showed that in both structures, levels of Casp2 and Δtau314 proteins correlate well, and both proteins are higher in HD patients than non-HD individuals. Our findings advance our understanding of the contribution of Casp2-mediated Δtau314 production to HD pathogenesis.
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31
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Matlahov I, van der Wel PC. Conformational studies of pathogenic expanded polyglutamine protein deposits from Huntington's disease. Exp Biol Med (Maywood) 2019; 244:1584-1595. [PMID: 31203656 PMCID: PMC6920524 DOI: 10.1177/1535370219856620] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Huntington’s disease, like other neurodegenerative diseases, continues to lack an
effective cure. Current treatments that address early symptoms ultimately fail
Huntington’s disease patients and their families, with the disease typically
being fatal within 10–15 years from onset. Huntington’s disease is an inherited
disorder with motor and mental impairment, and is associated with the genetic
expansion of a CAG codon repeat encoding a polyglutamine-segment-containing
protein called huntingtin. These Huntington’s disease mutations cause misfolding
and aggregation of fragments of the mutant huntingtin protein, thereby likely
contributing to disease toxicity through a combination of gain-of-toxic-function
for the misfolded aggregates and a loss of function from sequestration of
huntingtin and other proteins. As with other amyloid diseases, the mutant
protein forms non-native fibrillar structures, which in Huntington’s disease are
found within patients’ neurons. The intracellular deposits are associated with
dysregulation of vital processes, and inter-neuronal transport of aggregates may
contribute to disease progression. However, a molecular understanding of these
aggregates and their detrimental effects has been frustrated by insufficient
structural data on the misfolded protein state. In this review, we examine
recent developments in the structural biology of polyglutamine-expanded
huntingtin fragments, and especially the contributions enabled by advances in
solid-state nuclear magnetic resonance spectroscopy. We summarize and discuss
our current structural understanding of the huntingtin deposits and how this
information furthers our understanding of the misfolding mechanism and disease
toxicity mechanisms.
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Affiliation(s)
- Irina Matlahov
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Patrick Ca van der Wel
- Department of Structural Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, The Netherlands
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32
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Marx S, Van Gysel M, Breuer A, Dal Maso T, Michiels C, Wouters J, Le Calvé B. Potentialization of anticancer agents by identification of new chemosensitizers active under hypoxia. Biochem Pharmacol 2019; 162:224-236. [DOI: 10.1016/j.bcp.2019.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 01/04/2019] [Indexed: 12/27/2022]
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33
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Lois C, González I, Izquierdo-García D, Zürcher NR, Wilkens P, Loggia ML, Hooker JM, Rosas HD. Neuroinflammation in Huntington's Disease: New Insights with 11C-PBR28 PET/MRI. ACS Chem Neurosci 2018; 9:2563-2571. [PMID: 29719953 DOI: 10.1021/acschemneuro.8b00072] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease is a devastating neurodegenerative genetic disorder that causes progressive motor dysfunction, emotional disturbances, and cognitive impairment. Unfortunately, there is no treatment to cure or slow the progression of the disease. Neuroinflammation is one hallmark of Huntington's disease, and modulation of neuroinflammation has been suggested as a potential target for therapeutic intervention. The relationship between neuroinflammation markers and the disease pathology is still poorly understood. To improve our understanding of neuroinflammation in Huntington's disease, we measured translocator protein (TSPO) expression using 11C-PBR28 and simultaneous PET/MRI. Standardized-uptake-value ratios, normalized by whole brain uptake, were calculated for data acquired 60-90 min after radiotracer administration. We identified distinct patterns of regional neuroinflammation (as defined by TSPO overexpression relative to a control group) in the basal ganglia of Huntington's disease patients. These patterns were observed at the individual level in all patients, with region of interest analysis confirming significant differences between patients and the control group in the putamen and the pallidum. Additionally, we observed further distinct regional and subregional signatures, which may provide insights into phenotypical variability. For example, in certain Huntington's disease patients, we observed in vivo elevation of the level of TSPO binding in subnuclei in the thalamus and brainstem that have been previously associated with visual function, motor function, and motor coordination. Our main result is an objective score, based solely on 11C-PBR28 measurements, that correlates well with measurements of brain atrophy. We conclude that PET/MR imaging using 11C-PBR28 provides a high signal-to-background ratio and has the potential to be used to assess Huntington's disease progression. Our results suggest 11C-PBR28 might prove useful in clinical trials evaluating therapies targeting neuroinflammation.
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Affiliation(s)
- Cristina Lois
- Department of
Radiology, Gordon Center for Medical Imaging, Massachusetts General
Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
- Department of
Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
- Madrid-MIT M+Visión Consortium, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Iván González
- Department of
Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - David Izquierdo-García
- Department of
Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Nicole R. Zürcher
- Department of
Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Paul Wilkens
- Department of
Neurology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Marco L. Loggia
- Department of
Anesthesiology, Athinoula A. Martinos Center for Biomedical Imaging,
Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - Jacob M. Hooker
- Department of
Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
| | - H. Diana Rosas
- Department of
Neurology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts
General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, United States
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34
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Weishäupl D, Schneider J, Peixoto Pinheiro B, Ruess C, Dold SM, von Zweydorf F, Gloeckner CJ, Schmidt J, Riess O, Schmidt T. Physiological and pathophysiological characteristics of ataxin-3 isoforms. J Biol Chem 2018; 294:644-661. [PMID: 30455355 DOI: 10.1074/jbc.ra118.005801] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/08/2018] [Indexed: 12/18/2022] Open
Abstract
Ataxin-3 is a deubiquitinating enzyme and the affected protein in the neurodegenerative disorder Machado-Joseph disease (MJD). The ATXN3 gene is alternatively spliced, resulting in protein isoforms that differ in the number of ubiquitin-interacting motifs. Additionally, nonsynonymous SNPs in ATXN3 cause amino acid changes in ataxin-3, and one of these polymorphisms introduces a premature stop codon in one isoform. Here, we examined the effects of different ataxin-3 isoforms and of the premature stop codon on ataxin-3's physiological function and on main disease mechanisms. At the physiological level, we show that alternative splicing and the premature stop codon alter ataxin-3 stability and that ataxin-3 isoforms differ in their enzymatic deubiquitination activity, subcellular distribution, and interaction with other proteins. At the pathological level, we found that the expansion of the polyglutamine repeat leads to a stabilization of ataxin-3 and that ataxin-3 isoforms differ in their aggregation properties. Interestingly, we observed a functional interaction between normal and polyglutamine-expanded ATXN3 allelic variants. We found that interactions between different ATXN3 allelic variants modify the physiological and pathophysiological properties of ataxin-3. Our findings indicate that alternative splicing and interactions between different ataxin-3 isoforms affect not only major aspects of ataxin-3 function but also MJD pathogenesis. Our results stress the importance of considering isoforms of disease-causing proteins and their interplay with the normal allelic variant as disease modifiers in MJD and autosomal-dominantly inherited diseases in general.
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Affiliation(s)
- Daniel Weishäupl
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany.,the Graduate Training Center of Neuroscience, 72074 Tübingen, Germany
| | - Juliane Schneider
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Barbara Peixoto Pinheiro
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Corinna Ruess
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Sandra Maria Dold
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Felix von Zweydorf
- the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany, and
| | - Christian Johannes Gloeckner
- the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany, and.,the Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Jana Schmidt
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Olaf Riess
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
| | - Thorsten Schmidt
- From the Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany, .,the Center for Rare Diseases, 72076 Tübingen, Germany.,the NGS Competence Center, 72076 Tübingen, Germany
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35
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Martin DDO, Schmidt ME, Nguyen YT, Lazic N, Hayden MR. Identification of a novel caspase cleavage site in huntingtin that regulates mutant huntingtin clearance. FASEB J 2018; 33:3190-3197. [PMID: 30423259 DOI: 10.1096/fj.201701510rrr] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Huntington disease (HD) is a progressive neurodegenerative disease that initially affects the striatum and leads to changes in behavior and loss of motor coordination. It is caused by an expansion in the polyglutamine repeat at the N terminus of huntingtin (HTT) that leads to aggregation of mutant HTT. The loss of wild-type function, in combination with the toxic gain of function mutation, initiates various cell death pathways. Wild-type and mutant HTT are regulated by different posttranslational modifications that can positively or negatively regulate their function or toxicity. In particular, we have previously shown that caspase cleavage of mutant HTT at amino acid position aspartate 586 (D586) by caspase-6 is critical for the pathogenesis of the disease in an HD mouse model. Herein, we describe the identification of a new caspase cleavage site at position D572 that is mediated by caspase-1. Inhibition of caspase-1 also appeared to decrease proteolysis at D586, likely by blocking the downstream activation of caspase-6 through caspase-1. Inhibition of caspase cleavage at D572 significantly decreased mutant HTT aggregation and significantly increased the turnover of soluble mutant HTT. This suggests that caspase-1 may be a viable target to inhibit caspase cleavage of mutant HTT at both D572 and D586 to promote mutant HTT clearance.-Martin, D. D. O., Schmidt, M. E., Nguyen, Y. T., Lazic, N., Hayden, M. R. Identification of a novel caspase cleavage site in huntingtin that regulates mutant huntingtin clearance.
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Affiliation(s)
- Dale D O Martin
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Mandi E Schmidt
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Yen T Nguyen
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nikola Lazic
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
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36
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Matos CA, de Almeida LP, Nóbrega C. Machado-Joseph disease/spinocerebellar ataxia type 3: lessons from disease pathogenesis and clues into therapy. J Neurochem 2018; 148:8-28. [PMID: 29959858 DOI: 10.1111/jnc.14541] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/05/2018] [Accepted: 06/27/2018] [Indexed: 12/25/2022]
Abstract
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), is an incurable disorder, widely regarded as the most common form of spinocerebellar ataxia in the world. MJD/SCA3 arises from mutation of the ATXN3 gene, but this simple monogenic cause contrasts with the complexity of the pathogenic mechanisms that are currently admitted to underlie neuronal dysfunction and death. The aberrantly expanded protein product - ataxin-3 - is known to aggregate and generate toxic species that disrupt several cell systems, including autophagy, proteostasis, transcription, mitochondrial function and signalling. Over the years, research into putative therapeutic approaches has often been devoted to the development of strategies that counteract disease at different stages of cellular pathogenesis. Silencing the pathogenic protein, blocking aggregation, inhibiting toxic proteolytic processing and counteracting dysfunctions of the cellular systems affected have yielded promising ameliorating results in studies with cellular and animal models. The current review analyses the available studies dedicated to the investigation of MJD/SCA3 pathogenesis and the exploration of possible therapeutic strategies, focusing primarily on gene therapy and pharmacological approaches rooted on the molecular and cellular mechanisms of disease.
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Affiliation(s)
- Carlos A Matos
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Clévio Nóbrega
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal.,Department of Biomedical Sciences and Medicine, University of Algarve, Coimbra, Portugal.,Centre for Biomedical Research (CBMR), University of Algarve, Coimbra, Portugal.,Algarve Biomedical Center (ABC), University of Algarve, Faro, Portugal
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37
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Abstract
The 25 years since the identification of the gene responsible for Huntington disease (HD) have stood witness to profound discoveries about the nature of the disease and its pathogenesis. Despite this progress, however, the development of disease-modifying therapies has thus far been slow. Preclinical validation of the therapeutic potential of disrupted pathways in HD has led to the advancement of pharmacological agents, both novel and repurposed, for clinical evaluation. The most promising therapeutic approaches include huntingtin (HTT) lowering and modification as well as modulation of neuroinflammation and synaptic transmission. With clinical trials for many of these approaches imminent or currently ongoing, the coming years are promising not only for HD but also for more prevalent neurodegenerative disorders, such as Alzheimer and Parkinson disease, in which many of these pathways have been similarly implicated.
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38
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Tissue-Specific Upregulation of Drosophila Insulin Receptor (InR) Mitigates Poly(Q)-Mediated Neurotoxicity by Restoration of Cellular Transcription Machinery. Mol Neurobiol 2018; 56:1310-1329. [DOI: 10.1007/s12035-018-1160-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 05/29/2018] [Indexed: 12/11/2022]
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39
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Potkin KT, Potkin SG. New directions in therapeutics for Huntington disease. FUTURE NEUROLOGY 2018; 13:101-121. [PMID: 30800004 DOI: 10.2217/fnl-2017-0035] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 03/06/2018] [Indexed: 11/21/2022]
Abstract
Huntington disease (HD) is an autosomal dominantly inherited neurodegenerative disease that affects motor, cognitive and psychiatric functions, and ultimately leads to death. The pathology of the disease is based on an expansion of CAG repeats in exon 1 of the huntingtin gene on chromosome 4, which produces a mutant huntingtin protein (mHtt). This protein is involved in neurotoxicity and brain atrophy, and can form β-sheets and abnormal mHtt aggregates. Currently, there are no approved effective treatments for HD, although tetrabenazine (Xenazine™) and deutetrabenazine (AUSTEDO™) have been approved for treatment of the motor symptom chorea in HD. This literature review aims to address the latest research on promising therapeutics based on influencing the hypothesized pathological mechanisms.
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Affiliation(s)
- Katya T Potkin
- Stony Brook School of Medicine, 101 Nicolls Rd, Stony Brook, NY 11794, USA.,Stony Brook School of Medicine, 101 Nicolls Rd, Stony Brook, NY 11794, USA
| | - Steven G Potkin
- Professor Emeritus, Department of Psychiatry & Human Behavior, University of California, Irvine, CA 92697, USA.,Professor Emeritus, Department of Psychiatry & Human Behavior, University of California, Irvine, CA 92697, USA
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40
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Sethi R, Tripathi N, Pallapati AR, Gaikar A, Bharatam PV, Roy I. Does N-terminal huntingtin function as a 'holdase' for inhibiting cellular protein aggregation? FEBS J 2018; 285:1791-1811. [PMID: 29630769 DOI: 10.1111/febs.14457] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 03/14/2018] [Accepted: 03/29/2018] [Indexed: 11/28/2022]
Abstract
Proteolytic cleavage of huntingtin gives rise to N-terminal fragments. While the role of truncated mutant huntingtin is described in Huntington's disease (HD) pathogenesis, the function of N-terminal wild-type protein is less studied. The yeast model of HD is generated by the presence of FLAG tag and absence of polyproline tract as flanking sequences of the elongated polyglutamine stretch. We show that the same sequence derived from wild-type huntingtin exon1 is able to inhibit the aggregation of proteins in vitro and in yeast cells. It is able to stabilize client proteins as varied as luciferase, α-synuclein, and p53 in a soluble but non-native state. This is somewhat similar to the 'holdase' function of small heat shock proteins and 'nonchaperone proteins' which are able to stabilize partially unfolded client proteins in a nonspecific manner, slowing down their aggregation. Mutagenesis studies show this property to be localized at the N17 domain preceding the polyglutamine tract. Distortion of this ordered segment, either by deletion of this segment or mutation of a single residue (L4A), leads to decreased stability and increased aggregation of client proteins. It is interesting to note that the helical conformation of the N17 domain is also essential for aggregation of the N-terminal mutant protein. Our results provide evidence for a novel function for the amphipathic helix derived from exon1 of wild-type huntingtin.
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Affiliation(s)
- Ratnika Sethi
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
| | - Neha Tripathi
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Punjab, India
| | - Anusha R Pallapati
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
| | - Abhishek Gaikar
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
| | - Prasad V Bharatam
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research, Punjab, India.,Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Punjab, India
| | - Ipsita Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
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41
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Caterino M, Squillaro T, Montesarchio D, Giordano A, Giancola C, Melone MAB. Huntingtin protein: A new option for fixing the Huntington's disease countdown clock. Neuropharmacology 2018. [PMID: 29526547 DOI: 10.1016/j.neuropharm.2018.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Huntington's disease is a dreadful, incurable disorder. It springs from the autosomal dominant mutation in the first exon of the HTT gene, which encodes for the huntingtin protein (HTT) and results in progressive neurodegeneration. Thus far, all the attempted approaches to tackle the mutant HTT-induced toxicity causing this disease have failed. The mutant protein comes with the aberrantly expanded poly-glutamine tract. It is primarily to blame for the build-up of β-amyloid-like HTT aggregates, deleterious once broadened beyond the critical ∼35-37 repeats threshold. Recent experimental findings have provided valuable information on the molecular basis underlying this HTT-driven neurodegeneration. These findings indicate that the poly-glutamine siding regions and many post-translation modifications either abet or counter the poly-glutamine tract. This review provides an overall, up-to-date insight into HTT biophysics and structural biology, particularly discussing novel pharmacological options to specifically target the mutated protein and thus inhibit its functions and toxicity.
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Affiliation(s)
- Marco Caterino
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy
| | - Tiziana Squillaro
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy
| | - Daniela Montesarchio
- InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Department of Chemical Sciences, University of Napoli Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA; Department of Medicine, Surgery and Neuroscience University of Siena, Siena, Italy
| | - Concetta Giancola
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy.
| | - Mariarosa A B Melone
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.
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Abstract
Huntingtin (Htt) is a large (348 kDa) protein, essential for embryonic
development and involved in diverse cellular activities such as vesicular
transport, endocytosis, autophagy and transcription regulation1,2.
While an integrative understanding of Htt's biological functions is
lacking, the large number of identified interactors suggests that Htt serves as
a protein-protein interaction hub1,3,4.
Furthermore, Huntington’s disease is caused by a mutation in the Htt
gene, resulting in a pathogenic expansion of a polyglutamine (polyQ) repeat at
the N-terminus of Htt5,6. However, only limited structural
information on Htt is currently available. Here we employed cryo-electron
microscopy (cryo-EM) to determine the structure of full-length human Htt in a
complex with HAP40/F8A7 to 4 Å
resolution. Htt is largely α-helical and consists of three major domains.
The N- and C-terminal domains contain multiple HEAT repeats arranged in a
solenoid fashion. These domains are connected by a smaller bridge domain
containing different types of tandem repeats. HAP40 is also largely
α-helical and has a tetratricopeptide repeat (TPR)-like organization.
HAP40 binds in a cleft contacting the three Htt domains by hydrophobic and
electrostatic interactions, thereby stabilizing Htt conformation. These data
rationalize previous biochemical results and pave the way for an improved
understanding of Htt’s diverse cellular functions.
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43
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Molecular Mechanisms and Cellular Pathways Implicated in Machado-Joseph Disease Pathogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:349-367. [PMID: 29427113 DOI: 10.1007/978-3-319-71779-1_18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Machado-Joseph disease (MJD) is a dominantly inherited disorder originally described in people of Portuguese descent, and associated with the expansion of a CAG tract in the coding region of the causative gene MJD1/ATX3. The CAG repeats range from 10 to 51 in the normal population and from 55 to 87 in SCA3/MJD patients. MJD1 encodes ataxin-3, a protein whose physiological function has been linked to ubiquitin-mediated proteolysis. Despite the identification of the causative mutation, the pathogenic process leading to the neurodegeneration observed in the disease is not yet completely understood. In the past years, several studies identified different molecular mechanisms and cellular pathways as being impaired or deregulated in MJD. Autophagy, proteolysis or post-translational modifications, among other processes, were implicated in MJD pathogenesis. From these studies it was possible to identify new targets for therapeutic intervention, which in some cases proved successful in models of disease.
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44
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The CAG-polyglutamine repeat diseases: a clinical, molecular, genetic, and pathophysiologic nosology. HANDBOOK OF CLINICAL NEUROLOGY 2018; 147:143-170. [PMID: 29325609 DOI: 10.1016/b978-0-444-63233-3.00011-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Throughout the genome, unstable tandem nucleotide repeats can expand to cause a variety of neurologic disorders. Expansion of a CAG triplet repeat within a coding exon gives rise to an elongated polyglutamine (polyQ) tract in the resultant protein product, and accounts for a unique category of neurodegenerative disorders, known as the CAG-polyglutamine repeat diseases. The nine members of the CAG-polyglutamine disease family include spinal and bulbar muscular atrophy (SBMA), Huntington disease, dentatorubral pallidoluysian atrophy, and six spinocerebellar ataxias (SCA 1, 2, 3, 6, 7, and 17). All CAG-polyglutamine diseases are dominantly inherited, with the exception of SBMA, which is X-linked, and many CAG-polyglutamine diseases display anticipation, which is defined as increasing disease severity in successive generations of an affected kindred. Despite widespread expression of the different polyQ-expanded disease proteins throughout the body, each CAG-polyglutamine disease strikes a particular subset of neurons, although the mechanism for this cell-type selectivity remains poorly understood. While the different genes implicated in these disorders display amino acid homology only in the repeat tract domain, certain pathologic molecular processes have been implicated in almost all of the CAG-polyglutamine repeat diseases, including protein aggregation, proteolytic cleavage, transcription dysregulation, autophagy impairment, and mitochondrial dysfunction. Here we highlight the clinical and molecular genetic features of each distinct disorder, and then discuss common themes in CAG-polyglutamine disease pathogenesis, closing with emerging advances in therapy development.
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45
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Polyglutamine expansion diseases: More than simple repeats. J Struct Biol 2017; 201:139-154. [PMID: 28928079 DOI: 10.1016/j.jsb.2017.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/24/2017] [Accepted: 09/15/2017] [Indexed: 12/27/2022]
Abstract
Polyglutamine (polyQ) repeat-containing proteins are widespread in the human proteome but only nine of them are associated with highly incapacitating neurodegenerative disorders. The genetic expansion of the polyQ tract in disease-related proteins triggers a series of events resulting in neurodegeneration. The polyQ tract plays the leading role in the aggregation mechanism, but other elements modulate the aggregation propensity in the context of the full-length proteins, as implied by variations in the length of the polyQ tract required to trigger the onset of a given polyQ disease. Intrinsic features such as the presence of aggregation-prone regions (APRs) outside the polyQ segments and polyQ-flanking sequences, which synergistically participate in the aggregation process, are emerging for several disease-related proteins. The inherent polymorphic structure of polyQ stretches places the polyQ proteins in a central position in protein-protein interaction networks, where interacting partners may additionally shield APRs or reshape the aggregation course. Expansion of the polyQ tract perturbs the cellular homeostasis and contributes to neuronal failure by modulating protein-protein interactions and enhancing toxic oligomerization. Post-translational modifications further regulate self-assembly either by directly altering the intrinsic aggregation propensity of polyQ proteins, by modulating their interaction with different macromolecules or by modifying their withdrawal by the cell quality control machinery. Here we review the recent data on the multifaceted aggregation pathways of disease-related polyQ proteins, focusing on ataxin-3, the protein mutated in Machado-Joseph disease. Further mechanistic understanding of this network of events is crucial for the development of effective therapies for polyQ diseases.
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46
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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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47
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Mukherjee A, Williams DW. More alive than dead: non-apoptotic roles for caspases in neuronal development, plasticity and disease. Cell Death Differ 2017. [PMID: 28644437 PMCID: PMC5520460 DOI: 10.1038/cdd.2017.64] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nervous systems are arguably the most fascinating and complex structures in the known universe. How they are built, changed by experience and then degenerate are some of the biggest questions in biology. Regressive phenomena, such as neuron pruning and programmed cell death, have a key role in the building and maintenance of the nervous systems. Both of these cellular mechanisms deploy the caspase family of protease enzymes. In this review, we highlight the non-apoptotic function of caspases during nervous system development, plasticity and disease, particularly focussing on their role in structural remodelling. We have classified pruning as either macropruning, where complete branches are removed, or micropruning, where individual synapses or dendritic spines are eliminated. Finally we discuss open questions and possible future directions within the field.
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Affiliation(s)
- Amrita Mukherjee
- Centre for Developmental Neurobiology, King's College London, London, UK
| | - Darren W Williams
- Centre for Developmental Neurobiology, King's College London, London, UK
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48
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Sambataro F, Pennuto M. Post-translational Modifications and Protein Quality Control in Motor Neuron and Polyglutamine Diseases. Front Mol Neurosci 2017; 10:82. [PMID: 28408866 PMCID: PMC5374214 DOI: 10.3389/fnmol.2017.00082] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 03/08/2017] [Indexed: 11/30/2022] Open
Abstract
Neurodegenerative diseases, including motor neuron and polyglutamine (polyQ) diseases, are a broad class of neurological disorders. These diseases are characterized by neuronal dysfunction and death, and by the accumulation of toxic aggregation-prone proteins in the forms of inclusions and micro-aggregates. Protein quality control is a cellular mechanism to reduce the burden of accumulation of misfolded proteins, a function that results from the coordinated actions of chaperones and degradation systems, such as the ubiquitin-proteasome system (UPS) and autophagy-lysosomal degradation system. The rate of turnover, aggregation and degradation of the disease-causing proteins is modulated by post-translational modifications (PTMs), such as phosphorylation, arginine methylation, palmitoylation, acetylation, SUMOylation, ubiquitination, and proteolytic cleavage. Here, we describe how PTMs of proteins linked to motor neuron and polyQ diseases can either enhance or suppress protein quality control check and protein aggregation and degradation. The identification of molecular strategies targeting these modifications may offer novel avenues for the treatment of these yet incurable diseases.
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Affiliation(s)
- Fabio Sambataro
- Department of Experimental and Clinical Medical Sciences, University of UdineUdine, Italy
| | - Maria Pennuto
- Centre for Integrative Biology, Dulbecco Telethon Institute, University of TrentoTrento, Italy
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49
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Kuiper EFE, de Mattos EP, Jardim LB, Kampinga HH, Bergink S. Chaperones in Polyglutamine Aggregation: Beyond the Q-Stretch. Front Neurosci 2017; 11:145. [PMID: 28386214 PMCID: PMC5362620 DOI: 10.3389/fnins.2017.00145] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/08/2017] [Indexed: 01/12/2023] Open
Abstract
Expanded polyglutamine (polyQ) stretches in at least nine unrelated proteins lead to inherited neuronal dysfunction and degeneration. The expansion size in all diseases correlates with age at onset (AO) of disease and with polyQ protein aggregation, indicating that the expanded polyQ stretch is the main driving force for the disease onset. Interestingly, there is marked interpatient variability in expansion thresholds for a given disease. Between different polyQ diseases the repeat length vs. AO also indicates the existence of modulatory effects on aggregation of the upstream and downstream amino acid sequences flanking the Q expansion. This can be either due to intrinsic modulation of aggregation by the flanking regions, or due to differential interaction with other proteins, such as the components of the cellular protein quality control network. Indeed, several lines of evidence suggest that molecular chaperones have impact on the handling of different polyQ proteins. Here, we review factors differentially influencing polyQ aggregation: the Q-stretch itself, modulatory flanking sequences, interaction partners, cleavage of polyQ-containing proteins, and post-translational modifications, with a special focus on the role of molecular chaperones. By discussing typical examples of how these factors influence aggregation, we provide more insight on the variability of AO between different diseases as well as within the same polyQ disorder, on the molecular level.
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Affiliation(s)
- E F E Kuiper
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Eduardo P de Mattos
- Department of Cell Biology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil
| | - Laura B Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Department of Genetics, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil; Medical Genetics Service, Hospital de Clínicas de Porto AlegrePorto Alegre, Brazil; Departamento de Medicina Interna, Universidade Federal do Rio Grande do SulPorto Alegre, Brazil
| | - Harm H Kampinga
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
| | - Steven Bergink
- Department of Cell Biology, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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50
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Lee AL, Ung HM, Sands LP, Kikis EA. A new Caenorhabditis elegans model of human huntingtin 513 aggregation and toxicity in body wall muscles. PLoS One 2017; 12:e0173644. [PMID: 28282438 PMCID: PMC5345860 DOI: 10.1371/journal.pone.0173644] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 02/22/2017] [Indexed: 11/29/2022] Open
Abstract
Expanded polyglutamine repeats in different proteins are the known determinants of at least nine progressive neurodegenerative disorders whose symptoms include cognitive and motor impairment that worsen as patients age. One such disorder is Huntington’s Disease (HD) that is caused by a polyglutamine expansion in the human huntingtin protein (htt). The polyglutamine expansion destabilizes htt leading to protein misfolding, which in turn triggers neurodegeneration and the disruption of energy metabolism in muscle cells. However, the molecular mechanisms that underlie htt proteotoxicity have been somewhat elusive, and the muscle phenotypes have not been well studied. To generate tools to elucidate the basis for muscle dysfunction, we engineered Caenorhabditis elegans to express a disease-associated 513 amino acid fragment of human htt in body wall muscle cells. We show that this htt fragment aggregates in C. elegans in a polyglutamine length-dependent manner and is toxic. Toxicity manifests as motor impairment and a shortened lifespan. Compared to previous models, the data suggest that the protein context in which a polyglutamine tract is embedded alters aggregation propensity and toxicity, likely by affecting interactions with the muscle cell environment.
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Affiliation(s)
- Amy L. Lee
- Biology Department, The University of the South, Sewanee, TN, United States of America
| | - Hailey M. Ung
- Biology Department, The University of the South, Sewanee, TN, United States of America
| | - L. Paul Sands
- Biology Department, The University of the South, Sewanee, TN, United States of America
| | - Elise A. Kikis
- Biology Department, The University of the South, Sewanee, TN, United States of America
- * E-mail:
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