1
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Sturchio A, Duker AP, Muñoz-Sanjuan I, Espay AJ. Subtyping monogenic disorders: Huntington disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 193:171-184. [PMID: 36803810 DOI: 10.1016/b978-0-323-85555-6.00003-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Huntington disease is a highly disabling neurodegenerative disease characterized by psychiatric, cognitive, and motor deficits. The causal genetic mutation in huntingtin (Htt, also known as IT15), located on chromosome 4p16.3, leads to an expansion of a triplet coding for polyglutamine. The expansion is invariably associated with the disease when >39 repeats. Htt encodes for the protein huntingtin (HTT), which carries out many essential biological functions in the cell, in particular in the nervous system. The precise mechanism of toxicity is not known. Based on a one-gene-one-disease framework, the prevailing hypothesis ascribes toxicity to the universal aggregation of HTT. However, the aggregation process into mutant huntingtin (mHTT) is associated with a reduction of the levels of wild-type HTT. A loss of wild-type HTT may plausibly be pathogenic, contributing to the disease onset and progressive neurodegeneration. Moreover, many other biological pathways are altered in Huntington disease, such as in the autophagic system, mitochondria, and essential proteins beyond HTT, potentially explaining biological and clinical differences among affected individuals. As one gene does not mean one disease, future efforts at identifying specific Huntington subtypes are important to design biologically tailored therapeutic approaches that correct the corresponding biological pathways-rather than continuing to exclusively target the common denominator of HTT aggregation for elimination.
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Affiliation(s)
- Andrea Sturchio
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States; Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, Stockholm, Sweden.
| | - Andrew P Duker
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | | | - Alberto J Espay
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States.
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2
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Conroy F, Miller R, Alterman JF, Hassler MR, Echeverria D, Godinho BMDC, Knox EG, Sapp E, Sousa J, Yamada K, Mahmood F, Boudi A, Kegel-Gleason K, DiFiglia M, Aronin N, Khvorova A, Pfister EL. Chemical engineering of therapeutic siRNAs for allele-specific gene silencing in Huntington's disease models. Nat Commun 2022; 13:5802. [PMID: 36192390 PMCID: PMC9530163 DOI: 10.1038/s41467-022-33061-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 08/31/2022] [Indexed: 11/23/2022] Open
Abstract
Small interfering RNAs are a new class of drugs, exhibiting sequence-driven, potent, and sustained silencing of gene expression in vivo. We recently demonstrated that siRNA chemical architectures can be optimized to provide efficient delivery to the CNS, enabling development of CNS-targeted therapeutics. Many genetically-defined neurodegenerative disorders are dominant, favoring selective silencing of the mutant allele. In some cases, successfully targeting the mutant allele requires targeting single nucleotide polymorphism (SNP) heterozygosities. Here, we use Huntington’s disease (HD) as a model. The optimized compound exhibits selective silencing of mutant huntingtin protein in patient-derived cells and throughout the HD mouse brain, demonstrating SNP-based allele-specific RNAi silencing of gene expression in vivo in the CNS. Targeting a disease-causing allele using RNAi-based therapies could be helpful in a range of dominant CNS disorders where maintaining wild-type expression is essential. Chemically modified siRNAs distinguish between mutant and normal huntingtin based on a single nucleotide difference and lower mutant huntingtin specifically in patient derived cells and in a mouse model of Huntington’s disease.
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Affiliation(s)
- Faith Conroy
- Department of Medicine, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Rachael Miller
- Department of Medicine, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Julia F Alterman
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Matthew R Hassler
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Dimas Echeverria
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Bruno M D C Godinho
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Emily G Knox
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Ellen Sapp
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Jaquelyn Sousa
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Ken Yamada
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Farah Mahmood
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Adel Boudi
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Kimberly Kegel-Gleason
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Marian DiFiglia
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Neil Aronin
- Department of Medicine, UMass Chan Medical School, Worcester, MA, 01605, USA.,RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, MA, 01605, USA.
| | - Edith L Pfister
- Department of Medicine, UMass Chan Medical School, Worcester, MA, 01605, USA.
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3
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Shin JW, Shin A, Park SS, Lee JM. Haplotype-specific insertion-deletion variations for allele-specific targeting in Huntington's disease. Mol Ther Methods Clin Dev 2022; 25:84-95. [PMID: 35356757 PMCID: PMC8933729 DOI: 10.1016/j.omtm.2022.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 03/01/2022] [Indexed: 11/25/2022]
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disease caused by an expanded CAG repeat in huntingtin (HTT). Given an important role for HTT in development and significant neurodegeneration at the time of clinical manifestation in HD, early treatment of allele-specific drugs represents a promising strategy. The feasibility of an allele-specific antisense oligonucleotide (ASO) targeting single-nucleotide polymorphisms (SNPs) has been demonstrated in models of HD. Here, we constructed a map of haplotype-specific insertion-deletion variations (indels) to develop alternative mutant-HTT-specific strategies. We mapped indels annotated in the 1000 Genomes Project data on common HTT haplotypes, revealing candidate indels for mutant-specific HTT targeting. Subsequent sequencing of an HD family confirmed candidate sites and revealed additional allele-specific indels. Interestingly, the most common normal HTT haplotype carries indels of big allele length differences at many sites, further uncovering promising haplotype-specific targets. When patient-derived cells carrying the most common HTT diplotype were treated with ASOs targeting the mutant alleles of candidate indels (rs772629195 or rs72239206), complete mutant specificity was observed. In summary, our map of haplotype-specific indels permits the identification of allele-specific targets in HD subjects, potentially contributing to the development of safe HTT-lowering therapeutics that are suitable for early treatment in HD.
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Affiliation(s)
- Jun Wan Shin
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Aram Shin
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Seri S Park
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jong-Min Lee
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.,Medical and Population Genetics Program, Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
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4
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Park HJ, Han A, Kim JY, Choi J, Bae HS, Cho GB, Shin H, Shin EJ, Lee KI, Kim S, Lee JY, Song J. SUPT4H1-edited stem cell therapy rescues neuronal dysfunction in a mouse model for Huntington's disease. NPJ Regen Med 2022; 7:8. [PMID: 35046408 PMCID: PMC8770473 DOI: 10.1038/s41536-021-00198-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/30/2021] [Indexed: 01/29/2023] Open
Abstract
Huntington’s disease (HD) is a severe inherited neurological disorder caused by a CAG repeat expansion in the huntingtin gene (HTT), leading to the accumulation of mutant huntingtin with polyglutamine repeats. Despite its severity, there is no cure for this debilitating disease. HTT lowering strategies, including antisense oligonucleotides (ASO) showed promising results very recently. Attempts to develop stem cell-based therapeutics have shown efficacy in preclinical HD models. Using an HD patient’s autologous cells, which have genetic defects, may hamper therapeutic efficacy due to mutant HTT. Pretreating these cells to reduce mutant HTT expression and transcription may improve the transplanted cells’ therapeutic efficacy. To investigate this, we targeted the SUPT4H1 gene that selectively supports the transcription of long trinucleotide repeats. Transplanting SUPT4H1-edited HD-induced pluripotent stem cell-derived neural precursor cells (iPSC-NPCs) into the YAC128 HD transgenic mouse model improved motor function compared to unedited HD iPSC-NPCs. Immunohistochemical analysis revealed reduced mutant HTT expression without compensating wild-type HTT expression. Further, SUPT4H1 editing increased neuronal and decreased reactive astrocyte differentiation in HD iPSC-NPCs compared to the unedited HD iPSC-NPCs. This suggests that ex vivo editing of SUPT4H1 can reduce mutant HTT expression and provide a therapeutic gene editing strategy for autologous stem cell transplantation in HD.
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Affiliation(s)
- Hyun Jung Park
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, 335 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Korea.
| | - Areum Han
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, 335 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Korea
| | - Ji Yeon Kim
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, 335 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Korea
| | - Jiwoo Choi
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, 335 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Korea
| | - Hee Sook Bae
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Gyu-Bon Cho
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Hyejung Shin
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Eun Ji Shin
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Kang-In Lee
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Seokjoong Kim
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea
| | - Jae Young Lee
- Toolgen Inc., 219 Gasan Digital 1-ro, Geumcheon-gu, Seoul, 08594, Korea.
| | - Jihwan Song
- Department of Biomedical Science, CHA Stem Cell Institute, CHA University, 335 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Korea. .,iPS Bio, Inc., 3F, 16 Daewangpangyo-ro 712 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13522, Korea.
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5
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Jarosińska OD, Rüdiger SGD. Molecular Strategies to Target Protein Aggregation in Huntington's Disease. Front Mol Biosci 2021; 8:769184. [PMID: 34869596 PMCID: PMC8636123 DOI: 10.3389/fmolb.2021.769184] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by the aggregation of the mutant huntingtin (mHTT) protein in nerve cells. mHTT self-aggregates to form soluble oligomers and insoluble fibrils, which interfere in a number of key cellular functions. This leads to cell quiescence and ultimately cell death. There are currently still no treatments available for HD, but approaches targeting the HTT levels offer systematic, mechanism-driven routes towards curing HD and other neurodegenerative diseases. This review summarizes the current state of knowledge of the mRNA targeting approaches such as antisense oligonucleotides and RNAi system; and the novel methods targeting mHTT and aggregates for degradation via the ubiquitin proteasome or the autophagy-lysosomal systems. These methods include the proteolysis-targeting chimera, Trim-Away, autophagosome-tethering compound, autophagy-targeting chimera, lysosome-targeting chimera and approach targeting mHTT for chaperone-mediated autophagy. These molecular strategies provide a knowledge-based approach to target HD and other neurodegenerative diseases at the origin.
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Affiliation(s)
- Olga D. Jarosińska
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- Science for Life, Utrecht University, Utrecht, Netherlands
| | - Stefan G. D. Rüdiger
- Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Utrecht, Netherlands
- Science for Life, Utrecht University, Utrecht, Netherlands
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6
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Caron NS, Anderson C, Black HF, Sanders SS, Lemarié FL, Doty CN, Hayden MR. Reliable Resolution of Full-Length Huntingtin Alleles by Quantitative Immunoblotting. J Huntingtons Dis 2021; 10:355-365. [PMID: 34092649 DOI: 10.3233/jhd-200463] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Therapeutics that lower mutant huntingtin (mHTT) have shown promise in preclinical studies and are in clinical development for the treatment of Huntington's disease (HD). Multiple assays have been developed that either quantify mHTT or total HTT but may not accurately measure levels of wild type HTT (wtHTT) in biological samples. OBJECTIVE To optimize a method that can be used to resolve, quantify and directly compare levels of full length wtHTT and mHTT in HD samples. METHODS We provide a detailed quantitative immunoblotting protocol to reproducibly resolve full length wtHTT and mHTT in multiple HD mouse and patient samples. RESULTS We show that this assay can be modified, depending on the sample, to resolve wtHTT and mHTT with a wide range of polyglutamine differences (ΔQs 22-179). We also demonstrate that this method can be used to quantify allele-selective lowering of mHTT using an antisense oligonucleotide in HD patient-derived cells. CONCLUSION This quantitative immunoblotting method can be used to reliably resolve full length HTT alleles with ΔQs≥22 and allows for direct comparison of wtHTT and mHTT levels in HD samples.
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Affiliation(s)
- Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | | | - Hailey Findlay Black
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.,Current address: Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Fanny L Lemarié
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Crystal N Doty
- Centre for Molecular Medicine and Therapeutics, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
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7
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Beatriz M, Lopes C, Ribeiro ACS, Rego ACC. Revisiting cell and gene therapies in Huntington's disease. J Neurosci Res 2021; 99:1744-1762. [PMID: 33881180 DOI: 10.1002/jnr.24845] [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: 11/05/2020] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 12/31/2022]
Abstract
Neurodegenerative movement disorders, such as Huntington's disease (HD), share a progressive and relentless course with increasing motor disability, linked with neuropsychiatric impairment. These diseases exhibit diverse pathophysiological processes and are a topic of intense experimental and clinical research due to the lack of therapeutic options. Restorative therapies are promising approaches with the potential to restore brain circuits. However, there were less compelling results in the few clinical trials. In this review, we discuss cell replacement therapies applied to animal models and HD patients. We thoroughly describe the initial trials using fetal neural tissue transplantation and recent approaches based on alternative cell sources tested in several animal models. Stem cells were shown to generate the desired neuron phenotype and/or provide growth factors to the degenerating host cells. Besides, genetic approaches such as RNA interference and the CRISPR/Cas9 system have been studied in animal models and human-derived cells. New genetic manipulations have revealed the capability to control or counteract the effect of human gene mutations as described by the use of antisense oligonucleotides in a clinical trial. In HD, innovative strategies are at forefront of human testing and thus other brain genetic diseases may follow similar therapeutic strategies.
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Affiliation(s)
- Margarida Beatriz
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra - Polo I, Coimbra, Portugal
| | - Carla Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra - Polo I, Coimbra, Portugal.,IIIUC-Institute for Interdisciplinary Research, University of Coimbra - Polo II, Coimbra, Portugal
| | | | - Ana Cristina Carvalho Rego
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra - Polo I, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra - Polo III, Coimbra, Portugal
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8
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Chan L, Yokota T. Development and Clinical Applications of Antisense Oligonucleotide Gapmers. Methods Mol Biol 2021; 2176:21-47. [PMID: 32865780 DOI: 10.1007/978-1-0716-0771-8_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
DNA-like molecules called antisense oligonucleotides have opened new treatment possibilities for genetic diseases by offering a method of regulating gene expression. Antisense oligonucleotides are often used to suppress the expression of mutated genes which may interfere with essential downstream pathways. Since antisense oligonucleotides have been introduced for clinical use, different chemistries have been developed to further improve efficacy, potency, and safety. One such chemistry is a chimeric structure of a central block of deoxyribonucleotides flanked by sequences of modified nucleotides. Referred to as a gapmer, this chemistry produced promising results in the treatment of genetic diseases. Mipomersen and inotersen are examples of recent FDA-approved antisense oligonucleotide gapmers used for the treatment of familial hypercholesterolemia and hereditary transthyretin amyloidosis, respectively. In addition, volanesorsen was conditionally approved in the EU for the treatment of adult patients with familial chylomicronemia syndrome (FCS) in 2019. Many others are being tested in clinical trials or under preclinical development. This chapter will cover the development of mipomersen and inotersen in clinical trials, along with advancement in gapmer treatments for cancer, triglyceride-elevating genetic diseases, Huntington's disease, myotonic dystrophy, and prion diseases.
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Affiliation(s)
- Leanna Chan
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Arts and Science, University of Toronto, Toronto, ON, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada. .,Faculty of Arts and Science, University of Toronto, Toronto, ON, Canada. .,The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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9
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Kay C, Collins JA, Caron NS, Agostinho LDA, Findlay-Black H, Casal L, Sumathipala D, Dissanayake VHW, Cornejo-Olivas M, Baine F, Krause A, Greenberg JL, Paiva CLA, Squitieri F, Hayden MR. A Comprehensive Haplotype-Targeting Strategy for Allele-Specific HTT Suppression in Huntington Disease. Am J Hum Genet 2019; 105:1112-1125. [PMID: 31708117 PMCID: PMC6904807 DOI: 10.1016/j.ajhg.2019.10.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/11/2019] [Indexed: 11/20/2022] Open
Abstract
Huntington disease (HD) is a fatal neurodegenerative disorder caused by a gain-of-function mutation in HTT. Suppression of mutant HTT has emerged as a leading therapeutic strategy for HD, with allele-selective approaches targeting HTT SNPs now in clinical trials. Haplotypes associated with the HD mutation (A1, A2, A3a) represent panels of allele-specific gene silencing targets for efficient treatment of individuals with HD of Northern European and indigenous South American ancestry. Here we extend comprehensive haplotype analysis of the HD mutation to key populations of Southern European, South Asian, Middle Eastern, and admixed African ancestry. In each of these populations, the HD mutation occurs predominantly on the A2 HTT haplotype. Analysis of HD haplotypes across all affected population groups enables rational selection of candidate target SNPs for development of allele-selective gene silencing therapeutics worldwide. Targeting SNPs on the A1 and A2 haplotypes in parallel is essential to achieve treatment of the most HD-affected subjects in populations where HD is most prevalent. Current allele-specific approaches will leave a majority of individuals with HD untreated in populations where the HD mutation occurs most frequently on the A2 haplotype. We further demonstrate preclinical development of potent and selective ASOs targeting SNPs on the A2 HTT haplotype, representing an allele-specific treatment strategy for these individuals. On the basis of comprehensive haplotype analysis, we show the maximum proportion of HD-affected subjects that may be treated with three or four allele targets in different populations worldwide, informing current allele-specific HTT silencing strategies.
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Affiliation(s)
- Chris Kay
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Jennifer A Collins
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Nicholas S Caron
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Luciana de Andrade Agostinho
- PPGNEURO, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ 20270-004, Brazil; Centro Universitário UNIFAMINAS, Muriaé, MG 36880-000, Brazil; Hospital do Câncer de Muriaé, Muriaé, MG 36880-000, Brazil
| | - Hailey Findlay-Black
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | - Lorenzo Casal
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada
| | | | | | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima 15003, Peru; Center for Global Health, Universidad Peruana Cayetano Heredia, Lima 15102, Peru
| | - Fiona Baine
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa; Division of Human Genetics, Department of Pathology, University of Cape Town, Observatory 7925, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa
| | - Jacquie L Greenberg
- Division of Human Genetics, Department of Pathology, University of Cape Town, Observatory 7925, South Africa
| | - Carmen Lúcia Antão Paiva
- PPGNEURO, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ 20270-004, Brazil
| | - Ferdinando Squitieri
- Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy
| | - Michael R Hayden
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC V5Z4H4, Canada.
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10
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Li X, Li H, Dong Y, Gao B, Cheng H, Ni W, Gan S, Liu Z, Burgunder J, Wu Z. Haplotype analysis encompassing
HTT
gene in Chinese patients with Huntington's disease. Eur J Neurol 2019; 27:273-279. [DOI: 10.1111/ene.14072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 08/21/2019] [Indexed: 12/19/2022]
Affiliation(s)
- X.‐Y. Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - H.‐L. Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - Y. Dong
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - B. Gao
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - H.‐R. Cheng
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - W. Ni
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
| | - S.‐R. Gan
- Department of Neurology and Institute of Neurology First Affiliated Hospital Fujian Medical University FuzhouChina
| | - Z.‐J. Liu
- Department of Neurology and Institute of Neurology Huashan Hospital Shanghai Medical College Fudan University Shanghai China
| | - J.‐M. Burgunder
- Swiss Huntington’s Disease Centre, Siloah, Gümligen and Department of Neurology, University of Bern Bern Switzerland
| | - Z.‐Y. Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province Zhejiang University School of Medicine HangzhouChina
- Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto Zhejiang University HangzhouChina
- CAS Center for Excellence in Brain Science and Intelligence Technology Shanghai China
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11
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Kaemmerer WF, Grondin RC. The effects of huntingtin-lowering: what do we know so far? Degener Neurol Neuromuscul Dis 2019; 9:3-17. [PMID: 30881191 PMCID: PMC6413743 DOI: 10.2147/dnnd.s163808] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Therapies targeting mutant huntingtin DNA, mRNA, and protein have a chance at becoming the first disease-modifying treatments for Huntington’s disease, a fatal inherited neurodegenerative disorder for which only symptom management treatments are available today. This review focuses on evidence addressing several key questions pertinent to huntingtin-lowering, ranging from the functions of wild-type huntingtin (wtHTT) that may be disrupted by huntingtin-lowering treatments through the various ways huntingtin can be lowered, the tolerability of wtHTT-lowering in mice and primates, what has been found in the Ionis Pharmaceutical safety trial of a huntingtin-lowering therapy, and to the question of how much mutant huntingtin may need to be lowered for a therapy to be clinically effective. We conclude that adverse consequences of lowering wtHTT in animals appear to be brain region-specific, and/or dependent upon the animal’s stage of development and the amount by which huntingtin is lowered. Therefore, safe approaches to huntingtin-lowering in patients may be to lower huntingtin only moderately, or lower huntingtin only in the most affected brain regions, or lower huntingtin allele-selectively, or all of the above. Many additional questions about huntingtin-lowering remain open, and will only be answered by upcoming clinical trials, such as whether the delivery approaches currently planned will be adequate to get the treatment to the necessary brain regions, and whether non-allele-selective huntingtin-lowering will be safe in the long run. Meantime, there is a role for preclinical research to address key knowledge gaps, including the effects of non-allele-selective huntingtin-lowering on protein trafficking and viability at the cellular level, the tolerability of wtHTT-lowering in the corticostriatal connections of the primate brain, and the effects of this lowering on the functioning of neurotransmitter systems and the transport of neurotrophic factors to the striatum.
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Affiliation(s)
| | - Richard C Grondin
- Department of Neuroscience, University of Kentucky Medical Center, Lexington, KY, USA,
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12
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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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13
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Abstract
Polyglutamine diseases are hereditary degenerative disorders of the nervous system that have remained, to this date, untreatable. Promisingly, investigation into their molecular etiology and the development of increasingly perfected tools have contributed to the design of novel strategies with therapeutic potential. Encouraging studies have explored gene therapy as a means to counteract cell demise and loss in this context. The current chapter addresses the two main focuses of research in the area: the characteristics of the systems used to deliver nucleic acids to cells and the molecular and cellular actions of the therapeutic agents. Vectors used in gene therapy have to satisfyingly reach the tissues and cell types of interest, while eliciting the lowest toxicity possible. Both viral and non-viral systems have been developed for the delivery of nucleic acids to the central nervous system, each with its respective advantages and shortcomings. Since each polyglutamine disease is caused by mutation of a single gene, many gene therapy strategies have tried to halt degeneration by silencing the corresponding protein products, usually recurring to RNA interference. The potential of small interfering RNAs, short hairpin RNAs and microRNAs has been investigated. Overexpression of protective genes has also been evaluated as a means of decreasing mutant protein toxicity and operate beneficial alterations. Recent gene editing tools promise yet other ways of interfering with the disease-causing genes, at the most upstream points possible. Results obtained in both cell and animal models encourage further delving into this type of therapeutic strategies and support the future use of gene therapy in the treatment of polyglutamine diseases.
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Yu M, Fu Y, Liang Y, Song H, Yao Y, Wu P, Yao Y, Pan Y, Wen X, Ma L, Hexige S, Ding Y, Luo S, Lu B. Suppression of MAPK11 or HIPK3 reduces mutant Huntingtin levels in Huntington's disease models. Cell Res 2017; 27:1441-1465. [PMID: 29151587 PMCID: PMC5717400 DOI: 10.1038/cr.2017.113] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/14/2017] [Accepted: 08/08/2017] [Indexed: 12/13/2022] Open
Abstract
Most neurodegenerative disorders are associated with accumulation of disease-relevant proteins. Among them, Huntington disease (HD) is of particular interest because of its monogenetic nature. HD is mainly caused by cytotoxicity of the defective protein encoded by the mutant Huntingtin gene (HTT). Thus, lowering mutant HTT protein (mHTT) levels would be a promising treatment strategy for HD. Here we report two kinases HIPK3 and MAPK11 as positive modulators of mHTT levels both in cells and in vivo. Both kinases regulate mHTT via their kinase activities, suggesting that inhibiting these kinases may have therapeutic values. Interestingly, their effects on HTT levels are mHTT-dependent, providing a feedback mechanism in which mHTT enhances its own level thus contributing to mHTT accumulation and disease progression. Importantly, knockout of MAPK11 significantly rescues disease-relevant behavioral phenotypes in a knockin HD mouse model. Collectively, our data reveal new therapeutic entry points for HD and target-discovery approaches for similar diseases.
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Affiliation(s)
- Meng Yu
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yuhua Fu
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yijiang Liang
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Haikun Song
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yao Yao
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Peng Wu
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yuwei Yao
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yuyin Pan
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Xue Wen
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Lixiang Ma
- Department of Anatomy and Histology & Embryology, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Saiyin Hexige
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Yu Ding
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
| | - Shouqing Luo
- Peninsula Schools of Medicine and Dentistry, Institute of Translational and Stratified Medicine, University of Plymouth, Research Way, Plymouth, PL68BU, UK
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology, Huashan Hospital, School of Life Sciences, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai 200438, China
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15
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Influence of mismatched and bulged nucleotides on SNP-preferential RNase H cleavage of RNA-antisense gapmer heteroduplexes. Sci Rep 2017; 7:12532. [PMID: 28970564 PMCID: PMC5624880 DOI: 10.1038/s41598-017-12844-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/11/2017] [Indexed: 12/15/2022] Open
Abstract
This study focused on determining design rules for gapmer-type antisense oligonucleotides (ASOs), that can differentiate cleavability of two SNP variants of RNA in the presence of ribonuclease H based on the mismatch type and position in the heteroduplex. We describe the influence of structural motifs formed by several arrangements of multiple mismatches (various types of mismatches and their position within the ASO/target RNA duplex) on RNase H cleavage selectivity of five different SNP types. The targets were mRNA fragments of APP, SCA3, SNCA and SOD1 genes, carrying C-to-G, G-to-C, G-to-A, A-to-G and C-to-U substitutions. The results show that certain arrangements of mismatches enhance discrimination between wild type and mutant SNP alleles of RNA in vitro as well as in HeLa cells. Among the over 120 gapmers tested, we found two gapmers that caused preferential degradation of the mutant allele APP 692 G and one that led to preferential cleavage of the mutant SNCA 53 A allele, both in vitro and in cells. However, several gapmers promoted selective cleavage of mRNA mutant alleles in in vitro experiments only.
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16
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Haplotype-based stratification of Huntington's disease. Eur J Hum Genet 2017; 25:1202-1209. [PMID: 28832564 DOI: 10.1038/ejhg.2017.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 05/11/2017] [Accepted: 06/13/2017] [Indexed: 01/21/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by expansion of a CAG trinucleotide repeat in HTT, resulting in an extended polyglutamine tract in huntingtin. We and others have previously determined that the HD-causing expansion occurs on multiple different haplotype backbones, reflecting more than one ancestral origin of the same type of mutation. In view of the therapeutic potential of mutant allele-specific gene silencing, we have compared and integrated two major systems of HTT haplotype definition, combining data from 74 sequence variants to identify the most frequent disease-associated and control chromosome backbones and revealing that there is potential for additional resolution of HD haplotypes. We have used the large collection of 4078 heterozygous HD subjects analyzed in our recent genome-wide association study of HD age at onset to estimate the frequency of these haplotypes in European subjects, finding that common genetic variation at HTT can distinguish the normal and CAG-expanded chromosomes for more than 95% of European HD individuals. As a resource for the HD research community, we have also determined the haplotypes present in a series of publicly available HD subject-derived fibroblasts, induced pluripotent cells, and embryonic stem cells in order to facilitate efforts to develop inclusive methods of allele-specific HTT silencing applicable to most HD patients. Our data providing genetic guidance for therapeutic gene-based targeting will significantly contribute to the developments of rational treatments and implementation of precision medicine in HD.
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Dietrich P, Johnson IM, Alli S, Dragatsis I. Elimination of huntingtin in the adult mouse leads to progressive behavioral deficits, bilateral thalamic calcification, and altered brain iron homeostasis. PLoS Genet 2017; 13:e1006846. [PMID: 28715425 PMCID: PMC5536499 DOI: 10.1371/journal.pgen.1006846] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 07/31/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023] Open
Abstract
Huntington's Disease (HD) is an autosomal dominant progressive neurodegenerative disorder characterized by cognitive, behavioral and motor dysfunctions. HD is caused by a CAG repeat expansion in exon 1 of the HD gene that is translated into an expanded polyglutamine tract in the encoded protein, huntingtin (HTT). While the most significant neuropathology of HD occurs in the striatum, other brain regions are also affected and play an important role in HD pathology. To date there is no cure for HD, and recently strategies aiming at silencing HTT expression have been initiated as possible therapeutics for HD. However, the essential functions of HTT in the adult brain are currently unknown and hence the consequence of sustained suppression of HTT expression is unpredictable and can potentially be deleterious. Using the Cre-loxP system of recombination, we conditionally inactivated the mouse HD gene homologue at 3, 6 and 9 months of age. Here we show that elimination of Htt expression in the adult mouse results in behavioral deficits, progressive neuropathological changes including bilateral thalamic calcification, and altered brain iron homeostasis.
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Affiliation(s)
- Paula Dietrich
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Irudayam Maria Johnson
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Shanta Alli
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
| | - Ioannis Dragatsis
- Department of Physiology, The University of Tennessee, Health Science Center, Memphis, Tennessee, United States of America
- * E-mail:
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18
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CRISPR-Cas9 Mediated Gene-Silencing of the Mutant Huntingtin Gene in an In Vitro Model of Huntington's Disease. Int J Mol Sci 2017; 18:ijms18040754. [PMID: 28368337 PMCID: PMC5412339 DOI: 10.3390/ijms18040754] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/23/2017] [Accepted: 03/26/2017] [Indexed: 01/14/2023] Open
Abstract
Huntington’s disease (HD) is a fatal neurodegenerative genetic disease characterized by a loss of neurons in the striatum. It is caused by a mutation in the Huntingtin gene (HTT) that codes for the protein huntingtin (HTT). The mutant Huntingtin gene (mHTT) contains extra poly-glutamine (CAG) repeats from which the translated mutant huntingtin proteins (mHTT) undergo inappropriate post-translational modifications, conferring a toxic gain of function, in addition to its non-functional property. In order to curb the production of the mHTT, we have constructed two CRISPR (clustered regularly interspaced short palindromic repeat)-Cas9 (CRISPR associate protein) plasmids, among which one nicks the DNA at untranslated region upstream to the open reading frame (uORF), and the other nicks the DNA at exon1-intron boundary. The primary goal of this study was to apply this plasmid into mesenchymal stem cells (MSCs) extracted from the bone-marrow of YAC128 mice, which carries the transgene for HD. Our results suggest that the disruption of uORF through CRISPR-Cas9 influences the translation of mHTT negatively and, to a lesser extent, disrupts the exon1-intron boundary, which affects the translation of the mHTT. These findings also revealed the pattern of the nucleotide addition or deletion at the site of the DNA-nick in this model.
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Glorioso JC, Cohen JB, Carlisle DL, Munoz-Sanjuan I, Friedlander RM. Moving toward a gene therapy for Huntington's disease. Gene Ther 2016; 22:931-3. [PMID: 26633828 DOI: 10.1038/gt.2015.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J C Glorioso
- Department of Microbiology and Molecular Genetics, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - J B Cohen
- Department of Microbiology and Molecular Genetics, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - D L Carlisle
- Department of Neurological Surgery, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - I Munoz-Sanjuan
- CHDI Foundation/CHDI Management, Los Angeles, CA, USA. E-mail:
| | - R M Friedlander
- Department of Neurological Surgery, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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20
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Magner D, Biala E, Lisowiec-Wachnicka J, Kierzek E, Kierzek R. A Tandem Oligonucleotide Approach for SNP-Selective RNA Degradation Using Modified Antisense Oligonucleotides. PLoS One 2015; 10:e0142139. [PMID: 26544037 PMCID: PMC4704561 DOI: 10.1371/journal.pone.0142139] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/19/2015] [Indexed: 12/19/2022] Open
Abstract
Antisense oligonucleotides have been studied for many years as a tool for gene silencing. One of the most difficult cases of selective RNA silencing involves the alleles of single nucleotide polymorphisms, in which the allele sequence is differentiated by a single nucleotide. A new approach to improve the performance of allele selectivity for antisense oligonucleotides is proposed. It is based on the simultaneous application of two oligonucleotides. One is complementary to the mutated form of the targeted RNA and is able to activate RNase H to cleave the RNA. The other oligonucleotide, which is complementary to the wild type allele of the targeted RNA, is able to inhibit RNase H cleavage. Five types of SNPs, C/G, G/C, G/A, A/G, and C/U, were analyzed within the sequence context of genes associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease, ALS (Amyotrophic Lateral Sclerosis), and Machado-Joseph disease. For most analyzed cases, the application of the tandem approach increased allele-selective RNA degradation 1.5–15 fold relative to the use of a single antisense oligonucleotide. The presented study proves that differentiation between single substitution is highly dependent on the nature of the SNP and surrounding nucleotides. These variables are crucial for determining the proper length of the inhibitor antisense oligonucleotide. In the tandem approach, the comparison of thermodynamic stability of the favorable duplexes WT RNA-inhibitor and Mut RNA-gapmer with the other possible duplexes allows for the evaluation of chances for the allele-selective degradation of RNA. A larger difference in thermodynamic stability between favorable duplexes and those that could possibly form, usually results in the better allele selectivity of RNA degradation.
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Affiliation(s)
- Dorota Magner
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Ewa Biala
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Jolanta Lisowiec-Wachnicka
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Elzbieta Kierzek
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
| | - Ryszard Kierzek
- Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Noskowskiego, 12/14, Poland
- * E-mail:
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21
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Kay C, Collins JA, Skotte NH, Southwell AL, Warby SC, Caron NS, Doty CN, Nguyen B, Griguoli A, Ross CJ, Squitieri F, Hayden MR. Huntingtin Haplotypes Provide Prioritized Target Panels for Allele-specific Silencing in Huntington Disease Patients of European Ancestry. Mol Ther 2015. [PMID: 26201449 DOI: 10.1038/mt.2015.128] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Huntington disease (HD) is a dominant neurodegenerative disorder caused by a CAG repeat expansion in the Huntingtin gene (HTT). Heterozygous polymorphisms in cis with the mutation allow for allele-specific suppression of the pathogenic HTT transcript as a therapeutic strategy. To prioritize target selection, precise heterozygosity estimates are needed across diverse HD patient populations. Here we present the first comprehensive investigation of all common target alleles across the HTT gene, using 738 reference haplotypes from the 1000 Genomes Project and 2364 haplotypes from HD patients and relatives in Canada, Sweden, France, and Italy. The most common HD haplotypes (A1, A2, and A3a) define mutually exclusive sets of polymorphisms for allele-specific therapy in the greatest number of patients. Across all four populations, a maximum of 80% are treatable using these three target haplotypes. We identify a novel deletion found exclusively on the A1 haplotype, enabling potent and selective silencing of mutant HTT in approximately 40% of the patients. Antisense oligonucleotides complementary to the deletion reduce mutant A1 HTT mRNA by 78% in patient cells while sparing wild-type HTT expression. By suppressing specific haplotypes on which expanded CAG occurs, we demonstrate a rational approach to the development of allele-specific therapy for a monogenic disorder.
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Affiliation(s)
- Chris Kay
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jennifer A Collins
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Niels H Skotte
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Simon C Warby
- Department of Psychiatry, Université de Montréal, Montréal, Québec, Canada
| | - Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Crystal N Doty
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Betty Nguyen
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Annamaria Griguoli
- Neurogenetics Unit and Rare Disease Centre, IRCCS Neuromed Pozzilli (IS), Pozzilli, Italy
| | - Colin J Ross
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ferdinando Squitieri
- Neurogenetics Unit and Rare Disease Centre, IRCCS Neuromed Pozzilli (IS), Pozzilli, Italy
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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22
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Cheng HM, Chern Y, Chen IH, Liu CR, Li SH, Chun SJ, Rigo F, Bennett CF, Deng N, Feng Y, Lin CS, Yan YT, Cohen SN, Cheng TH. Effects on murine behavior and lifespan of selectively decreasing expression of mutant huntingtin allele by supt4h knockdown. PLoS Genet 2015; 11:e1005043. [PMID: 25760041 PMCID: PMC4356588 DOI: 10.1371/journal.pgen.1005043] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/30/2015] [Indexed: 01/13/2023] Open
Abstract
Production of protein containing lengthy stretches of polyglutamine encoded by multiple repeats of the trinucleotide CAG is a hallmark of Huntington's disease (HD) and of a variety of other inherited degenerative neurological and neuromuscular disorders. Earlier work has shown that interference with production of the transcription elongation protein SUPT4H results in decreased cellular capacity to transcribe mutant huntingtin gene (Htt) alleles containing long CAG expansions, but has little effect on expression of genes containing short CAG stretches. zQ175 and R6/2 are genetically engineered mouse strains whose genomes contain human HTT alleles that include greatly expanded CAG repeats and which are used as animal models for HD. Here we show that reduction of SUPT4H expression in brains of zQ175 mice by intracerebroventricular bolus injection of antisense 2'-O-methoxyethyl oligonucleotides (ASOs) directed against Supt4h, or in R6/2 mice by deletion of one copy of the Supt4h gene, results in a decrease in mRNA and protein encoded specifically by mutant Htt alleles. We further show that reduction of SUPT4H in mouse brains is associated with decreased HTT protein aggregation, and in R6/2 mice, also with prolonged lifespan and delay of the motor impairment that normally develops in these animals. Our findings support the view that targeting of SUPT4H function may be useful as a therapeutic countermeasure against HD.
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Affiliation(s)
- Hui-Min Cheng
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - I-Hui Chen
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Chia-Rung Liu
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Sih-Huei Li
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Seung J. Chun
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Frank Rigo
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - C. Frank Bennett
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Ning Deng
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Yanan Feng
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Chyuan-Sheng Lin
- Department of Pathology and Cell Biology & Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York, United States of America
| | - Yu-Ting Yan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Stanley N. Cohen
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Tzu-Hao Cheng
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan, Republic of China
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23
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Godinho BM, Malhotra M, O’Driscoll CM, Cryan JF. Delivering a disease-modifying treatment for Huntington's disease. Drug Discov Today 2015; 20:50-64. [DOI: 10.1016/j.drudis.2014.09.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/28/2014] [Accepted: 09/16/2014] [Indexed: 11/16/2022]
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24
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Skotte NH, Southwell AL, Østergaard ME, Carroll JB, Warby SC, Doty CN, Petoukhov E, Vaid K, Kordasiewicz H, Watt AT, Freier SM, Hung G, Seth PP, Bennett CF, Swayze EE, Hayden MR. Allele-specific suppression of mutant huntingtin using antisense oligonucleotides: providing a therapeutic option for all Huntington disease patients. PLoS One 2014; 9:e107434. [PMID: 25207939 PMCID: PMC4160241 DOI: 10.1371/journal.pone.0107434] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/11/2014] [Indexed: 01/10/2023] Open
Abstract
Huntington disease (HD) is an inherited, fatal neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene. The mutant protein causes neuronal dysfunction and degeneration resulting in motor dysfunction, cognitive decline, and psychiatric disturbances. Currently, there is no disease altering treatment, and symptomatic therapy has limited benefit. The pathogenesis of HD is complicated and multiple pathways are compromised. Addressing the problem at its genetic root by suppressing mutant huntingtin expression is a promising therapeutic strategy for HD. We have developed and evaluated antisense oligonucleotides (ASOs) targeting single nucleotide polymorphisms that are significantly enriched on HD alleles (HD-SNPs). We describe our structure-activity relationship studies for ASO design and find that adjusting the SNP position within the gap, chemical modifications of the wings, and shortening the unmodified gap are critical for potent, specific, and well tolerated silencing of mutant huntingtin. Finally, we show that using two distinct ASO drugs targeting the two allelic variants of an HD-SNP could provide a therapeutic option for all persons with HD; allele-specifically for roughly half, and non-specifically for the remainder.
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Affiliation(s)
- Niels H. Skotte
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amber L. Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Jeffrey B. Carroll
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, Washington, United States of America
| | - Simon C. Warby
- Center for Advanced Research in Sleep Medicine, Department of Psychiatry, University of Montréal, Montréal, Quebec, Canada
| | - Crystal N. Doty
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eugenia Petoukhov
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Andrew T. Watt
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Susan M. Freier
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Gene Hung
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Punit P. Seth
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - C. Frank Bennett
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Eric E. Swayze
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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25
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Sun X, Marque LO, Cordner Z, Pruitt JL, Bhat M, Li PP, Kannan G, Ladenheim EE, Moran TH, Margolis RL, Rudnicki DD. Phosphorodiamidate morpholino oligomers suppress mutant huntingtin expression and attenuate neurotoxicity. Hum Mol Genet 2014; 23:6302-17. [PMID: 25035419 DOI: 10.1093/hmg/ddu349] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Disease pathogenesis derives, at least in part, from the long polyglutamine tract encoded by mutant HTT. Therefore, considerable effort has been dedicated to the development of therapeutic strategies that significantly reduce the expression of the mutant HTT protein. Antisense oligonucleotides (ASOs) targeted to the CAG repeat region of HTT transcripts have been of particular interest due to their potential capacity to discriminate between normal and mutant HTT transcripts. Here, we focus on phosphorodiamidate morpholino oligomers (PMOs), ASOs that are especially stable, highly soluble and non-toxic. We designed three PMOs to selectively target expanded CAG repeat tracts (CTG22, CTG25 and CTG28), and two PMOs to selectively target sequences flanking the HTT CAG repeat (HTTex1a and HTTex1b). In HD patient-derived fibroblasts with expanded alleles containing 44, 77 or 109 CAG repeats, HTTex1a and HTTex1b were effective in suppressing the expression of mutant and non-mutant transcripts. CTGn PMOs also suppressed HTT expression, with the extent of suppression and the specificity for mutant transcripts dependent on the length of the targeted CAG repeat and on the CTG repeat length and concentration of the PMO. PMO CTG25 reduced HTT-induced cytotoxicity in vitro and suppressed mutant HTT expression in vivo in the N171-82Q transgenic mouse model. Finally, CTG28 reduced mutant HTT expression and improved the phenotype of Hdh(Q7/Q150) knock-in HD mice. These data demonstrate the potential of PMOs as an approach to suppressing the expression of mutant HTT.
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Affiliation(s)
- Xin Sun
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Leonard O Marque
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Zachary Cordner
- Behavioral Neuroscience Laboratory, Department of Psychiatry and Behavioral Sciences
| | - Jennifer L Pruitt
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Manik Bhat
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Pan P Li
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Geetha Kannan
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences
| | - Ellen E Ladenheim
- Behavioral Neuroscience Laboratory, Department of Psychiatry and Behavioral Sciences
| | - Timothy H Moran
- Behavioral Neuroscience Laboratory, Department of Psychiatry and Behavioral Sciences
| | - Russell L Margolis
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Department of Neurology, and Program of Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Dobrila D Rudnicki
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Program of Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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26
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Fiszer A, Krzyzosiak WJ. Oligonucleotide-based strategies to combat polyglutamine diseases. Nucleic Acids Res 2014; 42:6787-810. [PMID: 24848018 PMCID: PMC4066792 DOI: 10.1093/nar/gku385] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Considerable advances have been recently made in understanding the molecular aspects of pathogenesis and in developing therapeutic approaches for polyglutamine (polyQ) diseases. Studies on pathogenic mechanisms have extended our knowledge of mutant protein toxicity, confirmed the toxicity of mutant transcript and identified other toxic RNA and protein entities. One very promising therapeutic strategy is targeting the causative gene expression with oligonucleotide (ON) based tools. This straightforward approach aimed at halting the early steps in the cascade of pathogenic events has been widely tested for Huntington's disease and spinocerebellar ataxia type 3. In this review, we gather information on the use of antisense oligonucleotides and RNA interference triggers for the experimental treatment of polyQ diseases in cellular and animal models. We present studies testing non-allele-selective and allele-selective gene silencing strategies. The latter include targeting SNP variants associated with mutations or targeting the pathologically expanded CAG repeat directly. We compare gene silencing effectors of various types in a number of aspects, including their design, efficiency in cell culture experiments and pre-clinical testing. We discuss advantages, current limitations and perspectives of various ON-based strategies used to treat polyQ diseases.
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Affiliation(s)
- Agnieszka Fiszer
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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27
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Paulsen JS, Long JD, Johnson HJ, Aylward EH, Ross CA, Williams JK, Nance MA, Erwin CJ, Westervelt HJ, Harrington DL, Bockholt HJ, Zhang Y, McCusker EA, Chiu EM, Panegyres PK. Clinical and Biomarker Changes in Premanifest Huntington Disease Show Trial Feasibility: A Decade of the PREDICT-HD Study. Front Aging Neurosci 2014; 6:78. [PMID: 24795630 PMCID: PMC4000999 DOI: 10.3389/fnagi.2014.00078] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/05/2014] [Indexed: 11/13/2022] Open
Abstract
There is growing consensus that intervention and treatment of Huntington disease (HD) should occur at the earliest stage possible. Various early-intervention methods for this fatal neurodegenerative disease have been identified, but preventive clinical trials for HD are limited by a lack of knowledge of the natural history of the disease and a dearth of appropriate outcome measures. Objectives of the current study are to document the natural history of premanifest HD progression in the largest cohort ever studied and to develop a battery of imaging and clinical markers of premanifest HD progression that can be used as outcome measures in preventive clinical trials. Neurobiological predictors of Huntington's disease is a 32-site, international, observational study of premanifest HD, with annual examination of 1013 participants with premanifest HD and 301 gene-expansion negative controls between 2001 and 2012. Findings document 39 variables representing imaging, motor, cognitive, functional, and psychiatric domains, showing different rates of decline between premanifest HD and controls. Required sample size and models of premanifest HD are presented to inform future design of clinical and preclinical research. Preventive clinical trials in premanifest HD with participants who have a medium or high probability of motor onset are calculated to be as resource-effective as those conducted in diagnosed HD and could interrupt disease 7-12 years earlier. Methods and measures for preventive clinical trials in premanifest HD more than a dozen years from motor onset are also feasible. These findings represent the most thorough documentation of a clinical battery for experimental therapeutics in stages of premanifest HD, the time period for which effective intervention may provide the most positive possible outcome for patients and their families affected by this devastating disease.
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Affiliation(s)
- Jane S. Paulsen
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Neurology, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Psychology, The University of Iowa, Iowa City, IA, USA
| | - Jeffrey D. Long
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Biostatistics, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Hans J. Johnson
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Biomedical Engineering, College of Engineering, The University of Iowa, Iowa City, IA, USA
| | - Elizabeth H. Aylward
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, USA
| | | | | | - Martha A. Nance
- Department of Neurology, College of Medicine, The University of Minnesota, Minneapolis, MN, USA
| | - Cheryl J. Erwin
- Center of Excellence for Ethics, Humanities and Spirituality, Texas Tech University Health Sciences Center School of Medicine, Lubbock, TX, USA
| | - Holly J. Westervelt
- Department of Psychiatry and Human Behavior, Division of Biology and Medicine, Brown University, Providence, RI, USA
| | - Deborah L. Harrington
- Department of Radiology, School of Medicine, University of California, San Diego, CA, USA
- Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | | | - Ying Zhang
- Department of Biostatistics, Indiana University Fairbanks School of Public Health and Indiana University School of Medicine, Indianapolis, IN, USA
| | - Elizabeth A. McCusker
- Department of Neurology, Westmead Hospital, The University of Sydney, Sydney, NSW, Australia
| | - Edmond M. Chiu
- Department of Psychiatry, The University of Melbourne, Melbourne, VIC, Australia
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28
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Nishimura AL, Shum C, Scotter EL, Abdelgany A, Sardone V, Wright J, Lee YB, Chen HJ, Bilican B, Carrasco M, Maniatis T, Chandran S, Rogelj B, Gallo JM, Shaw CE. Allele-specific knockdown of ALS-associated mutant TDP-43 in neural stem cells derived from induced pluripotent stem cells. PLoS One 2014; 9:e91269. [PMID: 24651281 PMCID: PMC3961241 DOI: 10.1371/journal.pone.0091269] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 02/10/2014] [Indexed: 12/12/2022] Open
Abstract
TDP-43 is found in cytoplasmic inclusions in 95% of amyotrophic lateral sclerosis (ALS) and 60% of frontotemporal lobar degeneration (FTLD). Approximately 4% of familial ALS is caused by mutations in TDP-43. The majority of these mutations are found in the glycine-rich domain, including the variant M337V, which is one of the most common mutations in TDP-43. In order to investigate the use of allele-specific RNA interference (RNAi) as a potential therapeutic tool, we designed and screened a set of siRNAs that specifically target TDP-43(M337V) mutation. Two siRNA specifically silenced the M337V mutation in HEK293T cells transfected with GFP-TDP-43(wt) or GFP-TDP-43(M337V) or TDP-43 C-terminal fragments counterparts. C-terminal TDP-43 transfected cells show an increase of cytosolic inclusions, which are decreased after allele-specific siRNA in M337V cells. We then investigated the effects of one of these allele-specific siRNAs in induced pluripotent stem cells (iPSCs) derived from an ALS patient carrying the M337V mutation. These lines showed a two-fold increase in cytosolic TDP-43 compared to the control. Following transfection with the allele-specific siRNA, cytosolic TDP-43 was reduced by 30% compared to cells transfected with a scrambled siRNA. We conclude that RNA interference can be used to selectively target the TDP-43(M337V) allele in mammalian and patient cells, thus demonstrating the potential for using RNA interference as a therapeutic tool for ALS.
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Affiliation(s)
- Agnes L. Nishimura
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Carole Shum
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Emma L. Scotter
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Amr Abdelgany
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Valentina Sardone
- Department of Public Health, Neuroscience, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy
| | - Jamie Wright
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Youn-Bok Lee
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Han-Jou Chen
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Bilada Bilican
- MRC Centre for Regenerative Medicine and Centre for Neurodegeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Monica Carrasco
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Tom Maniatis
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Siddharthan Chandran
- MRC Centre for Regenerative Medicine and Centre for Neurodegeneration, University of Edinburgh, Edinburgh, United Kingdom
| | - Boris Rogelj
- Department of Biotechnology, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Jean-Marc Gallo
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
| | - Christopher E. Shaw
- Department of Clinical Neuroscience, King's College London, London, United Kingdom
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29
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Yu S, Liang Y, Palacino J, Difiglia M, Lu B. Drugging unconventional targets: insights from Huntington's disease. Trends Pharmacol Sci 2014; 35:53-62. [PMID: 24388390 DOI: 10.1016/j.tips.2013.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 12/03/2013] [Accepted: 12/05/2013] [Indexed: 12/12/2022]
Abstract
Classical targeted drug discovery is based on targeting druggable targets, typically kinases and receptors of which the function can be agonized or antagonized. This strategy meets difficulties in cases such as Huntington's disease (HD) and similar neurodegenerative disorders, where the pathological function of the protein causing the disease is not clear. HD is caused by mutant HTT protein (mHTT) containing an expanded polyglutamine (polyQ) stretch, but the function of mHTT and how mHTT causes HD are unknown, thus preventing efforts to screen for mHTT 'inhibitors'. However, HD is appealing for drug discovery because the genetic mutation is clear, as compared with other major neurodegenerative disorders. Although mHTT is not a conventional 'druggable' target, one approach that appears promising is lowering its level, which might be applicable to other neurodegenerative disorders and proteinopathies linked to aberrant accumulation of proteins. Here we review mHTT lowering strategies that might provide promising avenues for drugging such diseases.
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Affiliation(s)
- Shenliang Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yijian Liang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - James Palacino
- Developmental Molecular Pathways, Novartis Institutes for Biomedical Research, Cambridge, MA, USA.
| | - Marian Difiglia
- Mass General Institute for Neurodegenerative Disease, Charlestown, MA, USA.
| | - Boxun Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China; Mass General Institute for Neurodegenerative Disease, Charlestown, MA, USA.
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30
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Evers MM, Tran HD, Zalachoras I, Meijer OC, den Dunnen JT, van Ommen GJB, Aartsma-Rus A, van Roon-Mom WMC. Preventing formation of toxic N-terminal huntingtin fragments through antisense oligonucleotide-mediated protein modification. Nucleic Acid Ther 2013; 24:4-12. [PMID: 24380395 DOI: 10.1089/nat.2013.0452] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Huntington's disease (HD) is a progressive autosomal dominant disorder, caused by a CAG repeat expansion in the HTT gene, which results in expansion of a polyglutamine stretch at the N-terminal end of the huntingtin protein. Several studies have implicated the importance of proteolytic cleavage of mutant huntingtin in HD pathogenesis and it is generally accepted that N-terminal huntingtin fragments are more toxic than full-length protein. Important cleavage sites are encoded by exon 12 of HTT. Here we report proof of concept using antisense oligonucleotides to induce skipping of exon 12 in huntingtin pre-mRNA, thereby preventing the formation of a 586 amino acid N-terminal huntingtin fragment implicated in HD toxicity. In vitro studies showed successful exon skipping and appearance of a shorter huntingtin protein. Cleavage assays showed reduced 586 amino acid N-terminal huntingtin fragments in the treated samples. In vivo studies revealed exon skipping after a single injection of antisense oligonucleotides in the mouse striatum. Recent advances to inhibit the formation of mutant huntingtin using oligonucleotides seem promising therapeutic strategies for HD. Nevertheless, huntingtin is an essential protein and total removal has been shown to result in progressive neurodegeneration in vivo. Our proof of concept shows a completely novel approach to reduce mutant huntingtin toxicity not by reducing its expressing levels, but by modifying the huntingtin protein.
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Affiliation(s)
- Melvin M Evers
- 1 Department of Human Genetics, Leiden University Medical Center , The Netherlands
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31
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Synthetic zinc finger repressors reduce mutant huntingtin expression in the brain of R6/2 mice. Proc Natl Acad Sci U S A 2012; 109:E3136-45. [PMID: 23054839 DOI: 10.1073/pnas.1206506109] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by expanded CAG repeats in the huntingtin (HTT) gene. Although several palliative treatments are available, there is currently no cure and patients generally die 10-15 y after diagnosis. Several promising approaches for HD therapy are currently in development, including RNAi and antisense analogs. We developed a complementary strategy to test repression of mutant HTT with zinc finger proteins (ZFPs) in an HD model. We tested a "molecular tape measure" approach, using long artificial ZFP chains, designed to bind longer CAG repeats more strongly than shorter repeats. After optimization, stable ZFP expression in a model HD cell line reduced chromosomal expression of the mutant gene at both the protein and mRNA levels (95% and 78% reduction, respectively). This was achieved chromosomally in the context of endogenous mouse HTT genes, with variable CAG-repeat lengths. Shorter wild-type alleles, other genomic CAG-repeat genes, and neighboring genes were unaffected. In vivo, striatal adeno-associated virus viral delivery in R6/2 mice was efficient and revealed dose-dependent repression of mutant HTT in the brain (up to 60%). Furthermore, zinc finger repression was tested at several levels, resulting in protein aggregate reduction, reduced decline in rotarod performance, and alleviation of clasping in R6/2 mice, establishing a proof-of-principle for synthetic transcription factor repressors in the brain.
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32
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Magaña JJ, Velázquez-Pérez L, Cisneros B. Spinocerebellar ataxia type 2: clinical presentation, molecular mechanisms, and therapeutic perspectives. Mol Neurobiol 2012; 47:90-104. [PMID: 22996397 DOI: 10.1007/s12035-012-8348-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/05/2012] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant genetic disease characterized by cerebellar dysfunction associated with slow saccades, early hyporeflexia, severe tremor of postural or action type, peripheral neuropathy, cognitive disorders, and other multisystemic features. SCA2, one of the most common ataxias worldwide, is caused by the expansion of a CAG triplet repeat located in the N-terminal coding region of the ATXN2 gene, which results in the incorporation of a segment of polyglutamines in the mutant protein, being longer expansions associated with earlier onset and more sever disease in subsequent generations. In this review, we offer a detailed description of the clinical manifestations of SCA2 and compile the experimental evidence showing the participation of ataxin-2 in crucial cellular processes, including messenger RNA maturation and translation, and endocytosis. In addition, we discuss in the light of present data the potential molecular mechanisms underlying SCA2 pathogenesis. The mutant protein exhibits a toxic gain of function that is mainly attributed to the generation of neuronal inclusions of phosphorylated and/or proteolytic cleaved mutant ataxin-2, which might alter normal ataxin-2 function, leading to cell dysfunction and death of target cells. In the final part of this review, we discuss the perspectives of development of therapeutic strategies for SCA2. Based on previous experience with other polyglutamine disorders and considering the molecular basis of SCA2 pathogenesis, a nuclei-acid-based strategy focused on the specific silencing of the dominant disease allele that preserves the expression of the wild-type allele is highly desirable and might prevent toxic neurodegenerative sequelae.
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Affiliation(s)
- J J Magaña
- Department of Genetics, National Rehabilitation Institute (INR), Mexico City, Mexico
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33
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Rindt H, Yen PF, Thebeau CN, Peterson TS, Weisman GA, Lorson CL. Replacement of huntingtin exon 1 by trans-splicing. Cell Mol Life Sci 2012; 69:4191-204. [PMID: 22814437 DOI: 10.1007/s00018-012-1083-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 06/07/2012] [Accepted: 07/03/2012] [Indexed: 02/06/2023]
Abstract
Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by polyglutamine expansion in the amino-terminus of huntingtin (HTT). HD offers unique opportunities for promising RNA-based therapeutic approaches aimed at reducing mutant HTT expression, since the HD mutation is considered to be a "gain-of-function" mutation. Allele-specific strategies that preserve expression from the wild-type allele and reduce the levels of mutant protein would be of particular interest. Here, we have conducted proof-of-concept studies to demonstrate that spliceosome-mediated trans-splicing is a viable molecular strategy to specifically repair the HTT allele. We employed a dual plasmid transfection system consisting of a pre-mRNA trans-splicing module (PTM) containing HTT exon 1 and a HTT minigene to demonstrate that HTT exon 1 can be replaced in trans. We detected the presence of the trans-spliced RNA in which PTM exon 1 was correctly joined to minigene exons 2 and 3. Furthermore, exon 1 from the PTM was trans-spliced to the endogenous HTT pre-mRNA in cultured cells as well as disease-relevant models, including HD patient fibroblasts and primary neurons from a previously described HD mouse model. These results suggest that the repeat expansion of HTT can be repaired successfully not only in the context of synthetic minigenes but also within the context of HD neurons. Therefore, pre-mRNA trans-splicing may be a promising approach for the treatment of HD and other dominant genetic disorders.
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Affiliation(s)
- Hansjörg Rindt
- Department of Veterinary Pathobiology, Life Sciences Center, University of Missouri, Room 471G, Columbia, MO 65211, USA
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34
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Spadaro PA, Bredy TW. Emerging role of non-coding RNA in neural plasticity, cognitive function, and neuropsychiatric disorders. Front Genet 2012; 3:132. [PMID: 22811697 PMCID: PMC3395882 DOI: 10.3389/fgene.2012.00132] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/28/2012] [Indexed: 11/18/2022] Open
Abstract
Non-coding RNAs (ncRNAs) have emerged as critical regulators of transcription, epigenetic processes, and gene silencing, which make them ideal candidates for insight into molecular evolution and a better understanding of the molecular pathways of neuropsychiatric disease. Here, we provide an overview of the current state of knowledge regarding various classes of ncRNAs and their role in neural plasticity and cognitive function, and highlight the potential contribution they may make to the development of a variety of neuropsychiatric disorders, including schizophrenia, addiction, and fear-related anxiety disorders.
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Affiliation(s)
- Paola A Spadaro
- Psychiatric Epigenomics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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35
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Matsui M, Corey DR. Allele-selective inhibition of trinucleotide repeat genes. Drug Discov Today 2012; 17:443-50. [PMID: 22285529 PMCID: PMC3468950 DOI: 10.1016/j.drudis.2012.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/06/2011] [Accepted: 01/11/2012] [Indexed: 01/09/2023]
Abstract
Expanded trinucleotide repeats cause Huntington's disease (HD) and many other neurodegenerative disorders. There are no cures for these devastating illnesses and treatments are urgently needed. Each trinucleotide repeat disorder is the result of the mutation of just one gene, and agents that block expression of the mutant gene offer a promising option for treatment. Therapies that block expression of both mutant and wild-type alleles can have adverse effects, challenging researchers to develop strategies to lower levels of mutant protein while leaving adequate wild-type protein levels. Here, we review approaches that use synthetic nucleic acids to inhibit expression of trinucleotide repeat genes.
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Affiliation(s)
- Masayuki Matsui
- Departments of Pharmacology and Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
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36
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Zhang Y, Friedlander RM. Using non-coding small RNAs to develop therapies for Huntington's disease. Gene Ther 2012; 18:1139-49. [PMID: 22158031 DOI: 10.1038/gt.2011.170] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Huntington's disease (HD) is caused by an expansion of CAG triplets at the 5' end of the HD gene, which encodes a pathologically elongated polyglutamine stretch near the N-terminus of huntingtin. HD is an incurable autosomal-dominant neurodegenerative disease characterized by movement disorder, as well as emotional distress and dementia. The newly discovered roles of the non-coding small RNAs in specific degradation or translational suppression of the targeted mRNAs suggest a potential therapeutic approach of post-transcriptional gene silencing that targets the underlying disease etiology rather than the downstream pathological consequences. From pre-clinical trials in different HD animal models to cells from HD patients, small RNA interference has been applied to 'allele-non-specifically or allele-specifically' silence the mutant HD transgene or endogenous mutant HD allele. Silencing the mutant HD transgene significantly inhibits neurodegeneration, improves motor control, and extends survival of HD mice. With future improvement of mutant allele selectivity (preserving the expression of the neuroprotective wild-type allele), target specificity, efficacy and safety, as well as optimization of delivery methods, small non-coding RNA-based therapeutic applications will be a promising approach to treat HD.
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Affiliation(s)
- Y Zhang
- Department of Neurological Surgery, UPMC Presbyterian Hospital, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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37
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Liu CR, Chang CR, Chern Y, Wang TH, Hsieh WC, Shen WC, Chang CY, Chu IC, Deng N, Cohen S, Cheng TH. Spt4 Is Selectively Required for Transcription of Extended Trinucleotide Repeats. Cell 2012; 148:690-701. [DOI: 10.1016/j.cell.2011.12.032] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/03/2011] [Accepted: 12/13/2011] [Indexed: 10/28/2022]
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38
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Abstract
Polyglutamine neurodegenerative diseases result from the expansion of a trinucleotide CAG repeat, encoding a polyglutamine tract in the disease-causing protein. The process by which each polyglutamine protein exerts its toxicity is complex, involving a variety of mechanisms including transcriptional dysregulation, proteasome impairment and mitochondrial dysfunction. Thus, the most effective and widely applicable therapies are likely to be those designed to eliminate production of the mutant protein upstream of these deleterious effects. RNA-based approaches represent promising therapeutic strategies for polyglutamine diseases, offering the potential to suppress gene expression in a sequence-specific manner at the transcriptional and post-transcriptional levels. In particular, gene silencing therapies capable of discrimination between mutant and wildtype alleles, based on disease-linked polymorphisms or CAG repeat length, might prove crucial in cases where a loss of wild type function is deleterious. Novel methods, such as gene knockdown and replacement, seek to eliminate the technical difficulties associated with allele-specific silencing by avoiding the need to target specific mutations. With a variety of RNA technologies currently being developed to target multiple facets of polyglutamine pathogenesis, the emergence of an effective therapy seems imminent. However, numerous technical obstacles associated with design, discrimination and delivery must be overcome before RNA therapy can be effectively applied in the clinical setting.
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39
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Nucleic Acid-Based Therapy Approaches for Huntington's Disease. Neurol Res Int 2012; 2012:358370. [PMID: 22288011 PMCID: PMC3263636 DOI: 10.1155/2012/358370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/28/2011] [Accepted: 10/05/2011] [Indexed: 01/30/2023] Open
Abstract
Huntington's disease (HD) is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date.
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Genetically engineered mesenchymal stem cells as a proposed therapeutic for Huntington's disease. Mol Neurobiol 2011; 45:87-98. [PMID: 22161544 PMCID: PMC3259334 DOI: 10.1007/s12035-011-8219-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 11/09/2011] [Indexed: 12/14/2022]
Abstract
There is much interest in the use of mesenchymal stem cells/marrow stromal cells (MSC) to treat neurodegenerative disorders, in particular those that are fatal and difficult to treat, such as Huntington's disease. MSC present a promising tool for cell therapy and are currently being tested in FDA-approved phase I-III clinical trials for many disorders. In preclinical studies of neurodegenerative disorders, MSC have demonstrated efficacy, when used as delivery vehicles for neural growth factors. A number of investigators have examined the potential benefits of innate MSC-secreted trophic support and augmented growth factors to support injured neurons. These include overexpression of brain-derived neurotrophic factor and glial-derived neurotrophic factor, using genetically engineered MSC as a vehicle to deliver the cytokines directly into the microenvironment. Proposed regenerative approaches to neurological diseases using MSC include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation, MSC in the brain promote endogenous neuronal growth, encourage synaptic connection from damaged neurons, decrease apoptosis, reduce levels of free radicals, and regulate inflammation. These abilities are primarily modulated through paracrine actions. Clinical trials for MSC injection into the central nervous system to treat amyotrophic lateral sclerosis, traumatic brain injury, and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of Huntington's disease is discussed.
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Olson SD, Kambal A, Pollock K, Mitchell GM, Stewart H, Kalomoiris S, Cary W, Nacey C, Pepper K, Nolta JA. Examination of mesenchymal stem cell-mediated RNAi transfer to Huntington's disease affected neuronal cells for reduction of huntingtin. Mol Cell Neurosci 2011; 49:271-81. [PMID: 22198539 DOI: 10.1016/j.mcn.2011.12.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 11/27/2011] [Accepted: 12/01/2011] [Indexed: 01/31/2023] Open
Abstract
Huntington's disease (HD) is a fatal, autosomal dominant neurodegenerative disorder caused by an expanded trinucleotide (CAG) repeat in exon 1 of the huntingtin gene (Htt). This expansion creates a toxic polyglutamine tract in the huntingtin protein (HTT). Currently, there is no treatment for either the progression or prevention of the disease. RNA interference (RNAi) technology has shown promise in transgenic mouse models of HD by reducing expression of mutant HTT and slowing disease progression. The advancement of RNAi therapies to human clinical trials is hampered by problems delivering RNAi to affected neurons in a robust and sustainable manner. Mesenchymal stem cells (MSC) have demonstrated a strong safety profile in both completed and numerous ongoing clinical trials. MSC exhibit a number of innate therapeutic effects, such as immune system modulation, homing to injury, and cytokine release into damaged microenvironments. The ability of MSC to transfer larger molecules and even organelles suggested their potential usefulness as delivery vehicles for therapeutic RNA inhibition. In a series of model systems we have found evidence that MSC can transfer RNAi targeting both reporter genes and mutant huntingtin in neural cell lines. MSC expressing shRNA antisense to GFP were found to decrease expression of GFP in SH-SY5Y cells after co-culture when assayed by flow cytometry. Additionally MSC expressing shRNA antisense to HTT were able to decrease levels of mutant HTT expressed in both U87 and SH-SY5Y target cells when assayed by Western blot and densitometry. These results are encouraging for expanding the therapeutic abilities of both RNAi and MSC for future treatments of Huntington's disease.
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Affiliation(s)
- Scott D Olson
- Institute for Regenerative Cures, University of California Davis Health System, 2921 Stockton Blvd Room #1300, Sacramento, CA 95817, USA
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Lowery JW, Rosen V. Allele-specific RNA interference in FOP silencing the FOP gene. Gene Ther 2011; 19:701-2. [PMID: 22130446 DOI: 10.1038/gt.2011.190] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Reddy PH, Shirendeb UP. Mutant huntingtin, abnormal mitochondrial dynamics, defective axonal transport of mitochondria, and selective synaptic degeneration in Huntington's disease. Biochim Biophys Acta Mol Basis Dis 2011; 1822:101-10. [PMID: 22080977 DOI: 10.1016/j.bbadis.2011.10.016] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 11/19/2022]
Abstract
Huntington's disease (HD) is a progressive, fatal neurodegenerative disease caused by expanded polyglutamine repeats in the HD gene. HD is characterized by chorea, seizures, involuntary movements, dystonia, cognitive decline, intellectual impairment and emotional disturbances. Research into mutant huntingtin (Htt) and mitochondria has found that mutant Htt interacts with the mitochondrial protein dynamin-related protein 1 (Drp1), enhances GTPase Drp1 enzymatic activity, and causes excessive mitochondrial fragmentation and abnormal distribution, leading to defective axonal transport of mitochondria and selective synaptic degeneration. This article summarizes latest developments in HD research and focuses on the role of abnormal mitochondrial dynamics and defective axonal transport in HD neurons. This article also discusses the therapeutic strategies that decrease mitochondrial fragmentation and neuronal damage in HD.
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Affiliation(s)
- P Hemachandra Reddy
- Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
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Evers MM, Pepers BA, van Deutekom JCT, Mulders SAM, den Dunnen JT, Aartsma-Rus A, van Ommen GJB, van Roon-Mom WMC. Targeting several CAG expansion diseases by a single antisense oligonucleotide. PLoS One 2011; 6:e24308. [PMID: 21909428 PMCID: PMC3164722 DOI: 10.1371/journal.pone.0024308] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 08/04/2011] [Indexed: 12/16/2022] Open
Abstract
To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion in the HTT gene, which results in an expansion of a glutamine stretch at the N-terminal end of the huntingtin protein. This polyglutamine expansion plays a central role in the disease and results in the accumulation of cytoplasmic and nuclear aggregates. Here, we make use of modified 2'-O-methyl phosphorothioate (CUG)n triplet-repeat antisense oligonucleotides to effectively reduce mutant huntingtin transcript and protein levels in patient-derived Huntington's disease fibroblasts and lymphoblasts. The most effective antisense oligonucleotide, (CUG)(7), also reduced mutant ataxin-1 and ataxin-3 mRNA levels in spinocerebellar ataxia 1 and 3, respectively, and atrophin-1 in dentatorubral-pallidoluysian atrophy patient derived fibroblasts. This antisense oligonucleotide is not only a promising therapeutic tool to reduce mutant huntingtin levels in Huntington's disease but our results in spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy cells suggest that this could also be applicable to other polyglutamine expansion disorders as well.
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Affiliation(s)
- Melvin M. Evers
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Barry A. Pepers
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | - Johan T. den Dunnen
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Leiden Genome Technology Center, Leiden University Medical Center, Leiden, The Netherlands
| | - Annemieke Aartsma-Rus
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Gert-Jan B. van Ommen
- Center for Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Sierant M, Paduszynska A, Kazmierczak-Baranska J, Nacmias B, Sorbi S, Bagnoli S, Sochacka E, Nawrot B. Specific Silencing of L392V PSEN1 Mutant Allele by RNA Interference. Int J Alzheimers Dis 2011; 2011:809218. [PMID: 21559198 PMCID: PMC3090069 DOI: 10.4061/2011/809218] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Accepted: 02/07/2011] [Indexed: 01/07/2023] Open
Abstract
RNA interference (RNAi) technology provides a powerful molecular tool to reduce an expression of selected genes in eukaryotic cells. Short interfering RNAs (siRNAs) are the effector molecules that trigger RNAi. Here, we describe siRNAs that discriminate between the wild type and mutant (1174 C→G) alleles of human Presenilin1 gene (PSEN1). This mutation, resulting in L392V PSEN1 variant, contributes to early onset familial Alzheimer's disease. Using the dual fluorescence assay, flow cytometry and fluorescent microscopy we identified positions 8th–11th, within the central part of the antisense strand, as the most sensitive to mismatches. 2-Thiouridine chemical modification introduced at the 3′-end of the antisense strand improved the allele discrimination, but wobble base pairing adjacent to the mutation site abolished the siRNA activity. Our data indicate that siRNAs can be designed to discriminate between the wild type and mutant alleles of genes that differ by just a single nucleotide.
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Affiliation(s)
- Malgorzata Sierant
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Lodz, Sienkiewicza 112, Poland
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Hu J, Liu J, Corey DR. Allele-selective inhibition of huntingtin expression by switching to an miRNA-like RNAi mechanism. ACTA ACUST UNITED AC 2011; 17:1183-8. [PMID: 21095568 DOI: 10.1016/j.chembiol.2010.10.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 10/27/2010] [Accepted: 10/29/2010] [Indexed: 12/15/2022]
Abstract
Inhibiting expression of huntingtin (HTT) protein is a promising strategy for treating Huntington's disease (HD), but indiscriminant inhibition of both wild-type and mutant alleles may lead to toxicity. An ideal silencing agent would block expression of mutant HTT while leaving expression of wild-type HTT intact. We observe that fully complementary duplex RNAs targeting the expanded CAG repeat within HTT mRNA block expression of both alleles. Switching the RNAi mechanism toward that used by miRNAs by introducing one or more mismatched bases into these duplex RNAs leads to potent (<10 nM) and highly selective (>30-fold relative to wild-type HTT) inhibition of mutant HTT expression in patient-derived cells. Potent, allele selective inhibition of HTT by mismatched RNAs provides a new option for developing HD therapeutics.
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Affiliation(s)
- Jiaxin Hu
- The Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9041, USA
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Joyce N, Annett G, Wirthlin L, Olson S, Bauer G, Nolta JA. Mesenchymal stem cells for the treatment of neurodegenerative disease. Regen Med 2011; 5:933-46. [PMID: 21082892 DOI: 10.2217/rme.10.72] [Citation(s) in RCA: 356] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mesenchymal stem cells/marrow stromal cells (MSCs) present a promising tool for cell therapy, and are currently being tested in US FDA-approved clinical trials for myocardial infarction, stroke, meniscus injury, limb ischemia, graft-versus-host disease and autoimmune disorders. They have been extensively tested and proven effective in preclinical studies for these and many other disorders. There is currently a great deal of interest in the use of MSCs to treat neurodegenerative diseases, in particular for those that are fatal and difficult to treat, such as Huntington's disease and amyotrophic lateral sclerosis. Proposed regenerative approaches to neurological diseases using MSCs include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation into the brain, MSCs promote endogenous neuronal growth, decrease apoptosis, reduce levels of free radicals, encourage synaptic connection from damaged neurons and regulate inflammation, primarily through paracrine actions. MSCs transplanted into the brain have been demonstrated to promote functional recovery by producing trophic factors that induce survival and regeneration of host neurons. Therapies will capitalize on the innate trophic support from MSCs or on augmented growth factor support, such as delivering brain-derived neurotrophic factor or glial-derived neurotrophic factor into the brain to support injured neurons, using genetically engineered MSCs as the delivery vehicles. Clinical trials for MSC injection into the CNS to treat traumatic brain injury and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of neurodegenerative disorders are discussed.
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Affiliation(s)
- Nanette Joyce
- Department of Internal Medicine, Division of Hematology/Oncology, Stem Cell Program, University of California, Davis, CA 95817, USA
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Gagnon KT, Pendergraff HM, Deleavey GF, Swayze EE, Potier P, Randolph J, Roesch EB, Chattopadhyaya J, Damha MJ, Bennett CF, Montaillier C, Lemaitre M, Corey DR. Allele-selective inhibition of mutant huntingtin expression with antisense oligonucleotides targeting the expanded CAG repeat. Biochemistry 2010; 49:10166-78. [PMID: 21028906 DOI: 10.1021/bi101208k] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Huntington's disease (HD) is a currently incurable neurodegenerative disease caused by the expansion of a CAG trinucleotide repeat within the huntingtin (HTT) gene. Therapeutic approaches include selectively inhibiting the expression of the mutated HTT allele while conserving function of the normal allele. We have evaluated a series of antisense oligonucleotides (ASOs) targeted to the expanded CAG repeat within HTT mRNA for their ability to selectively inhibit expression of mutant HTT protein. Several ASOs incorporating a variety of modifications, including bridged nucleic acids and phosphorothioate internucleotide linkages, exhibited allele-selective silencing in patient-derived fibroblasts. Allele-selective ASOs did not affect the expression of other CAG repeat-containing genes and selectivity was observed in cell lines containing minimal CAG repeat lengths representative of most HD patients. Allele-selective ASOs left HTT mRNA intact and did not support ribonuclease H activity in vitro. We observed cooperative binding of multiple ASO molecules to CAG repeat-containing HTT mRNA transcripts in vitro. These results are consistent with a mechanism involving inhibition at the level of translation. ASOs targeted to the CAG repeat of HTT provide a starting point for the development of oligonucleotide-based therapeutics that can inhibit gene expression with allelic discrimination in patients with HD.
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Affiliation(s)
- Keith T Gagnon
- Department of Pharmacology, UT Southwestern Medical Center, ND8.136B, Dallas, Texas 75390-9041, United States
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Zuccato C, Valenza M, Cattaneo E. Molecular Mechanisms and Potential Therapeutical Targets in Huntington's Disease. Physiol Rev 2010; 90:905-81. [DOI: 10.1152/physrev.00041.2009] [Citation(s) in RCA: 626] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the gene encoding for huntingtin protein. A lot has been learned about this disease since its first description in 1872 and the identification of its causative gene and mutation in 1993. We now know that the disease is characterized by several molecular and cellular abnormalities whose precise timing and relative roles in pathogenesis have yet to be understood. HD is triggered by the mutant protein, and both gain-of-function (of the mutant protein) and loss-of-function (of the normal protein) mechanisms are involved. Here we review the data that describe the emergence of the ancient huntingtin gene and of the polyglutamine trait during the last 800 million years of evolution. We focus on the known functions of wild-type huntingtin that are fundamental for the survival and functioning of the brain neurons that predominantly degenerate in HD. We summarize data indicating how the loss of these beneficial activities reduces the ability of these neurons to survive. We also review the different mechanisms by which the mutation in huntingtin causes toxicity. This may arise both from cell-autonomous processes and dysfunction of neuronal circuitries. We then focus on novel therapeutical targets and pathways and on the attractive option to counteract HD at its primary source, i.e., by blocking the production of the mutant protein. Strategies and technologies used to screen for candidate HD biomarkers and their potential application are presented. Furthermore, we discuss the opportunities offered by intracerebral cell transplantation and the likely need for these multiple routes into therapies to converge at some point as, ideally, one would wish to stop the disease process and, at the same time, possibly replace the damaged neurons.
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Affiliation(s)
- Chiara Zuccato
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
| | - Marta Valenza
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
| | - Elena Cattaneo
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
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Harnessing chaperone-mediated autophagy for the selective degradation of mutant huntingtin protein. Nat Biotechnol 2010; 28:256-63. [PMID: 20190739 DOI: 10.1038/nbt.1608] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 01/25/2010] [Indexed: 02/02/2023]
Abstract
Huntington's Disease (HD) is a dominantly inherited pathology caused by the accumulation of mutant huntingtin protein (HTT) containing an expanded polyglutamine (polyQ) tract. As the polyglutamine binding peptide 1 (QBP1) is known to bind an expanded polyQ tract but not the polyQ motif found in normal HTT, we selectively targeted mutant HTT for degradation by expressing a fusion molecule comprising two copies of QBP1 and copies of two different heat shock cognate protein 70 (HSC70)-binding motifs in cellular and mouse models of HD. Chaperone-mediated autophagy contributed to the specific degradation of mutant HTT in cultured cells expressing the construct. Intrastriatal delivery of a virus expressing the fusion molecule ameliorated the disease phenotype in the R6/2 mouse model of HD. Similar adaptor molecules comprising HSC70-binding motifs fused to an appropriate structure-specific binding agent(s) may have therapeutic potential for treating diseases caused by misfolded proteins other than those with expanded polyQ tracts.
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