1
|
Niewiadomska-Cimicka A, Fievet L, Surdyka M, Jesion E, Keime C, Singer E, Eisenmann A, Kalinowska-Poska Z, Nguyen HHP, Fiszer A, Figiel M, Trottier Y. AAV-Mediated CAG-Targeting Selectively Reduces Polyglutamine-Expanded Protein and Attenuates Disease Phenotypes in a Spinocerebellar Ataxia Mouse Model. Int J Mol Sci 2024; 25:4354. [PMID: 38673939 PMCID: PMC11050704 DOI: 10.3390/ijms25084354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Polyglutamine (polyQ)-encoding CAG repeat expansions represent a common disease-causing mutation responsible for several dominant spinocerebellar ataxias (SCAs). PolyQ-expanded SCA proteins are toxic for cerebellar neurons, with Purkinje cells (PCs) being the most vulnerable. RNA interference (RNAi) reagents targeting transcripts with expanded CAG reduce the level of various mutant SCA proteins in an allele-selective manner in vitro and represent promising universal tools for treating multiple CAG/polyQ SCAs. However, it remains unclear whether the therapeutic targeting of CAG expansion can be achieved in vivo and if it can ameliorate cerebellar functions. Here, using a mouse model of SCA7 expressing a mutant Atxn7 allele with 140 CAGs, we examined the efficacy of short hairpin RNAs (shRNAs) targeting CAG repeats expressed from PHP.eB adeno-associated virus vectors (AAVs), which were introduced into the brain via intravascular injection. We demonstrated that shRNAs carrying various mismatches with the CAG target sequence reduced the level of polyQ-expanded ATXN7 in the cerebellum, albeit with varying degrees of allele selectivity and safety profile. An shRNA named A4 potently reduced the level of polyQ-expanded ATXN7, with no effect on normal ATXN7 levels and no adverse side effects. Furthermore, A4 shRNA treatment improved a range of motor and behavioral parameters 23 weeks after AAV injection and attenuated the disease burden of PCs by preventing the downregulation of several PC-type-specific genes. Our results show the feasibility of the selective targeting of CAG expansion in the cerebellum using a blood-brain barrier-permeable vector to attenuate the disease phenotype in an SCA mouse model. Our study represents a significant advancement in developing CAG-targeting strategies as a potential therapy for SCA7 and possibly other CAG/polyQ SCAs.
Collapse
Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Lorraine Fievet
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Magdalena Surdyka
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Ewelina Jesion
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Céline Keime
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Elisabeth Singer
- Centre for Rare Diseases (ZSE), University of Tuebingen, 72076 Tuebingen, Germany;
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Aurélie Eisenmann
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Zaneta Kalinowska-Poska
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Hoa Huu Phuc Nguyen
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland;
| | - Maciej Figiel
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Yvon Trottier
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| |
Collapse
|
2
|
Brunet de Courssou JB, Durr A, Adams D, Corvol JC, Mariani LL. Antisense therapies in neurological diseases. Brain 2021; 145:816-831. [PMID: 35286370 DOI: 10.1093/brain/awab423] [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: 07/12/2021] [Revised: 10/16/2021] [Accepted: 11/01/2021] [Indexed: 12/18/2022] Open
Abstract
Advances in targeted regulation of gene expression allowed new therapeutic approaches for monogenic neurological diseases. Molecular diagnosis has paved the way to personalized medicine targeting the pathogenic roots: DNA or its RNA transcript. These antisense therapies rely on modified nucleotides sequences (single-strand DNA or RNA, both belonging to the antisense oligonucleotides family, or double-strand interfering RNA) to act specifically on pathogenic target nucleic acids, thanks to complementary base pairing. Depending on the type of molecule, chemical modifications and target, base pairing will lead alternatively to splicing modifications of primary transcript RNA or transient messenger RNA degradation or non-translation. The key to success for neurodegenerative diseases also depends on the ability to reach target cells. The most advanced antisense therapies under development in neurological disorders are presented here, at the clinical stage of development, either at phase 3 or market authorization stage, such as in spinal amyotrophy, Duchenne muscular dystrophy, transthyretin-related hereditary amyloidosis, porphyria and amyotrophic lateral sclerosis; or in earlier clinical phase 1 B, for Huntington disease, synucleinopathies and tauopathies. We also discuss antisense therapies at the preclinical stage, such as in some tauopathies, spinocerebellar ataxias or other rare neurological disorders. Each subtype of antisense therapy, antisense oligonucleotides or interfering RNA, has proved target engagement or even clinical efficacy in patients; undisputable recent advances for severe and previously untreatable neurological disorders. Antisense therapies show great promise, but many unknowns remain. Expanding the initial successes achieved in orphan or rare diseases to other disorders will be the next challenge, as shown by the recent failure in Huntington disease or due to long-term preclinical toxicity in multiple system atrophy and cystic fibrosis. This will be critical in the perspective of new planned applications to premanifest mutation carriers, or other non-genetic degenerative disorders such as multiple system atrophy or Parkinson disease.
Collapse
Affiliation(s)
- Jean-Baptiste Brunet de Courssou
- Assistance Publique Hôpitaux de Paris, Department of Neurology, CIC Neurosciences, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Alexandra Durr
- Sorbonne University, Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
| | - David Adams
- Department of Neurology, Bicêtre hospital, Assistance Publique Hôpitaux de Paris, Centre de Référence National des Neuropathies Périphériques Rares, Paris Saclay University, INSERM U 1195, Le Kremlin Bicêtre, France
| | - Jean-Christophe Corvol
- Assistance Publique Hôpitaux de Paris, Department of Neurology, CIC Neurosciences, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France.,Sorbonne University, Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
| | - Louise-Laure Mariani
- Assistance Publique Hôpitaux de Paris, Department of Neurology, CIC Neurosciences, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France.,Sorbonne University, Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
| |
Collapse
|
3
|
Borbolla-Jiménez FV, Del Prado-Audelo ML, Cisneros B, Caballero-Florán IH, Leyva-Gómez G, Magaña JJ. New Perspectives of Gene Therapy on Polyglutamine Spinocerebellar Ataxias: From Molecular Targets to Novel Nanovectors. Pharmaceutics 2021; 13:1018. [PMID: 34371710 PMCID: PMC8309146 DOI: 10.3390/pharmaceutics13071018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 01/03/2023] Open
Abstract
Seven of the most frequent spinocerebellar ataxias (SCAs) are caused by a pathological expansion of a cytosine, adenine and guanine (CAG) trinucleotide repeat located in exonic regions of unrelated genes, which in turn leads to the synthesis of polyglutamine (polyQ) proteins. PolyQ proteins are prone to aggregate and form intracellular inclusions, which alter diverse cellular pathways, including transcriptional regulation, protein clearance, calcium homeostasis and apoptosis, ultimately leading to neurodegeneration. At present, treatment for SCAs is limited to symptomatic intervention, and there is no therapeutic approach to prevent or reverse disease progression. This review provides a compilation of the experimental advances obtained in cell-based and animal models toward the development of gene therapy strategies against polyQ SCAs, providing a discussion of their potential application in clinical trials. In the second part, we describe the promising potential of nanotechnology developments to treat polyQ SCA diseases. We describe, in detail, how the design of nanoparticle (NP) systems with different physicochemical and functionalization characteristics has been approached, in order to determine their ability to evade the immune system response and to enhance brain delivery of molecular tools. In the final part of this review, the imminent application of NP-based strategies in clinical trials for the treatment of polyQ SCA diseases is discussed.
Collapse
Affiliation(s)
- Fabiola V. Borbolla-Jiménez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico;
- Programa de Ciencias Biomédicas, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - María Luisa Del Prado-Audelo
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey Campus Ciudad de México, Ciudad de México 14380, Mexico;
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México 07360, Mexico;
| | - Isaac H. Caballero-Florán
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
- Departamento de Farmacia, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México 07360, Mexico
| | - Gerardo Leyva-Gómez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - Jonathan J. Magaña
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico;
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey Campus Ciudad de México, Ciudad de México 14380, Mexico;
| |
Collapse
|
4
|
Current Status of Gene Therapy Research in Polyglutamine Spinocerebellar Ataxias. Int J Mol Sci 2021; 22:ijms22084249. [PMID: 33921915 PMCID: PMC8074016 DOI: 10.3390/ijms22084249] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/14/2021] [Accepted: 04/14/2021] [Indexed: 12/26/2022] Open
Abstract
Polyglutamine spinocerebellar ataxias (PolyQ SCAs) are a group of 6 rare autosomal dominant diseases, which arise from an abnormal CAG repeat expansion in the coding region of their causative gene. These neurodegenerative ataxic disorders are characterized by progressive cerebellar degeneration, which translates into progressive ataxia, the main clinical feature, often accompanied by oculomotor deficits and dysarthria. Currently, PolyQ SCAs treatment is limited only to symptomatic mitigation, and no therapy is available to stop or delay the disease progression, which culminates with death. Over the last years, many promising gene therapy approaches were investigated in preclinical studies and could lead to a future treatment to stop or delay the disease development. Here, we summed up the most promising of these therapies, categorizing them in gene augmentation therapy, gene silencing strategies, and gene edition approaches. While several of the reviewed strategies are promising, there is still a gap from the preclinical results obtained and their translation to clinical studies. However, there is an increase in the number of approved gene therapies, as well as a constant development in their safety and efficacy profiles. Thus, it is expected that in a near future some of the promising strategies reviewed here could be tested in a clinical setting and if successful provide hope for SCAs patients.
Collapse
|
5
|
Burman RJ, Watson LM, Smith DC, Raimondo JV, Ballo R, Scholefield J, Cowley SA, Wood MJA, Kidson SH, Greenberg LJ. Molecular and electrophysiological features of spinocerebellar ataxia type seven in induced pluripotent stem cells. PLoS One 2021; 16:e0247434. [PMID: 33626063 PMCID: PMC7904216 DOI: 10.1371/journal.pone.0247434] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 02/07/2021] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the ATXN7 gene. Patients with this disease suffer from a degeneration of their cerebellar Purkinje neurons and retinal photoreceptors that result in a progressive ataxia and loss of vision. As with many neurodegenerative diseases, studies of pathogenesis have been hindered by a lack of disease-relevant models. To this end, we have generated induced pluripotent stem cells (iPSCs) from a cohort of SCA7 patients in South Africa. First, we differentiated the SCA7 affected iPSCs into neurons which showed evidence of a transcriptional phenotype affecting components of STAGA (ATXN7 and KAT2A) and the heat shock protein pathway (DNAJA1 and HSP70). We then performed electrophysiology on the SCA7 iPSC-derived neurons and found that these cells show features of functional aberrations. Lastly, we were able to differentiate the SCA7 iPSCs into retinal photoreceptors that also showed similar transcriptional aberrations to the SCA7 neurons. Our findings give technical insights on how iPSC-derived neurons and photoreceptors can be derived from SCA7 patients and demonstrate that these cells express molecular and electrophysiological differences that may be indicative of impaired neuronal health. We hope that these findings will contribute towards the ongoing efforts to establish the cell-derived models of neurodegenerative diseases that are needed to develop patient-specific treatments.
Collapse
Affiliation(s)
- Richard J. Burman
- Department of Human Biology, University of Cape Town, South Africa
- Neuroscience Institute, University of Cape Town, South Africa
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Lauren M. Watson
- Department of Pathology, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Danielle C. Smith
- Department of Pathology, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Joseph V. Raimondo
- Department of Human Biology, University of Cape Town, South Africa
- Neuroscience Institute, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Robea Ballo
- Department of Human Biology, University of Cape Town, South Africa
| | - Janine Scholefield
- Gene Expression & Biophysics Group, Synthetic Biology ERA, CSIR Biosciences, Pretoria, Gauteng, South Africa
| | - Sally A. Cowley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Matthew J. A. Wood
- Department of Paediatrics, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Susan H. Kidson
- Department of Human Biology, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| | - Leslie J. Greenberg
- Department of Pathology, University of Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
| |
Collapse
|
6
|
Przybyl L, Wozna-Wysocka M, Kozlowska E, Fiszer A. What, When and How to Measure-Peripheral Biomarkers in Therapy of Huntington's Disease. Int J Mol Sci 2021; 22:ijms22041561. [PMID: 33557131 PMCID: PMC7913877 DOI: 10.3390/ijms22041561] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 12/11/2022] Open
Abstract
Among the main challenges in further advancing therapeutic strategies for Huntington’s disease (HD) is the development of biomarkers which must be applied to assess the efficiency of the treatment. HD is a dreadful neurodegenerative disorder which has its source of pathogenesis in the central nervous system (CNS) but is reflected by symptoms in the periphery. Visible symptoms include motor deficits and slight changes in peripheral tissues, which can be used as hallmarks for prognosis of the course of HD, e.g., the onset of the disease symptoms. Knowing how the pathology develops in the context of whole organisms is crucial for the development of therapy which would be the most beneficial for patients, as well as for proposing appropriate biomarkers to monitor disease progression and/or efficiency of treatment. We focus here on molecular peripheral biomarkers which could be used as a measurable outcome of potential therapy. We present and discuss a list of wet biomarkers which have been proposed in recent years to measure pre- and postsymptomatic HD. Interestingly, investigation of peripheral biomarkers in HD can unravel new aspects of the disease pathogenesis. This especially refers to inflammatory proteins or specific immune cells which attract scientific attention in neurodegenerative disorders.
Collapse
Affiliation(s)
- Lukasz Przybyl
- Laboratory of Mammalian Model Organisms, Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Poland
- Correspondence: (L.P.); (A.F.)
| | - Magdalena Wozna-Wysocka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Poland; (M.W.-W.); (E.K.)
| | - Emilia Kozlowska
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Poland; (M.W.-W.); (E.K.)
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry Polish Academy of Sciences, 61-704 Poznan, Poland; (M.W.-W.); (E.K.)
- Correspondence: (L.P.); (A.F.)
| |
Collapse
|
7
|
Antisense Transcription across Nucleotide Repeat Expansions in Neurodegenerative and Neuromuscular Diseases: Progress and Mysteries. Genes (Basel) 2020; 11:genes11121418. [PMID: 33261024 PMCID: PMC7760973 DOI: 10.3390/genes11121418] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Unstable repeat expansions and insertions cause more than 30 neurodegenerative and neuromuscular diseases. Remarkably, bidirectional transcription of repeat expansions has been identified in at least 14 of these diseases. More remarkably, a growing number of studies has been showing that both sense and antisense repeat RNAs are able to dysregulate important cellular pathways, contributing together to the observed clinical phenotype. Notably, antisense repeat RNAs from spinocerebellar ataxia type 7, myotonic dystrophy type 1, Huntington's disease and frontotemporal dementia/amyotrophic lateral sclerosis associated genes have been implicated in transcriptional regulation of sense gene expression, acting either at a transcriptional or posttranscriptional level. The recent evidence that antisense repeat RNAs could modulate gene expression broadens our understanding of the pathogenic pathways and adds more complexity to the development of therapeutic strategies for these disorders. In this review, we cover the amazing progress made in the understanding of the pathogenic mechanisms associated with repeat expansion neurodegenerative and neuromuscular diseases with a focus on the impact of antisense repeat transcription in the development of efficient therapies.
Collapse
|
8
|
Artificial miRNAs targeting CAG repeat expansion in ORFs cause rapid deadenylation and translation inhibition of mutant transcripts. Cell Mol Life Sci 2020; 78:1577-1596. [PMID: 32696070 PMCID: PMC7904544 DOI: 10.1007/s00018-020-03596-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 07/01/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
Abstract
Polyglutamine (polyQ) diseases are incurable neurological disorders caused by CAG repeat expansion in the open reading frames (ORFs) of specific genes. This type of mutation in the HTT gene is responsible for Huntington’s disease (HD). CAG repeat-targeting artificial miRNAs (art-miRNAs) were shown as attractive therapeutic approach for polyQ disorders as they caused allele-selective decrease in the level of mutant proteins. Here, using polyQ disease models, we aimed to demonstrate how miRNA-based gene expression regulation is dependent on target sequence features. We show that the silencing efficiency and selectivity of art-miRNAs is influenced by the localization of the CAG repeat tract within transcript and the specific sequence context. Furthermore, we aimed to reveal the events leading to downregulation of mutant polyQ proteins and found very rapid activation of translational repression and HTT transcript deadenylation. Slicer-activity of AGO2 was dispensable in this process, as determined in AGO2 knockout cells generated with CRISPR-Cas9 technology. We also showed highly allele-selective downregulation of huntingtin in human HD neural progenitors (NPs). Taken together, art-miRNA activity may serve as a model of the cooperative activity and targeting of ORF regions by endogenous miRNAs.
Collapse
|
9
|
Kotowska-Zimmer A, Ostrovska Y, Olejniczak M. Universal RNAi Triggers for the Specific Inhibition of Mutant Huntingtin, Atrophin-1, Ataxin-3, and Ataxin-7 Expression. MOLECULAR THERAPY. NUCLEIC ACIDS 2019; 19:562-571. [PMID: 31927329 PMCID: PMC6957814 DOI: 10.1016/j.omtn.2019.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/04/2019] [Accepted: 12/11/2019] [Indexed: 12/13/2022]
Abstract
The expansion of CAG repeats within the coding region of associated genes is responsible for nine inherited neurodegenerative disorders including Huntington’s disease (HD), spinocerebellar ataxias (SCAs), and dentatorubral-pallidoluysian atrophy (DRPLA). Despite years of research aimed at developing an effective method of treatment, these diseases remain incurable and only their symptoms are controlled. The purpose of this study was to develop effective and allele-selective genetic tools for silencing the expression of mutated genes containing expanded CAG repeats. Here we show that repeat-targeting short hairpin RNAs preferentially reduce the levels of mutant huntingtin, atrophin-1, ataxin-3, and ataxin-7 proteins in patient-derived fibroblasts and may serve as universal allele-selective reagents for polyglutamine (polyQ) diseases.
Collapse
Affiliation(s)
- Anna Kotowska-Zimmer
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Yuliya Ostrovska
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Marta Olejniczak
- Department of Genome Engineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland; Dystrogen Gene Therapies, 1415 W 37(th) Street, Chicago, IL, USA.
| |
Collapse
|
10
|
Niewiadomska-Cimicka A, Trottier Y. Molecular Targets and Therapeutic Strategies in Spinocerebellar Ataxia Type 7. Neurotherapeutics 2019; 16:1074-1096. [PMID: 31432449 PMCID: PMC6985300 DOI: 10.1007/s13311-019-00778-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a rare autosomal dominant neurodegenerative disorder characterized by progressive neuronal loss in the cerebellum, brainstem, and retina, leading to cerebellar ataxia and blindness as major symptoms. SCA7 is due to the expansion of a CAG triplet repeat that is translated into a polyglutamine tract in ATXN7. Larger SCA7 expansions are associated with earlier onset of symptoms and more severe and rapid disease progression. Here, we summarize the pathological and genetic aspects of SCA7, compile the current knowledge about ATXN7 functions, and then focus on recent advances in understanding the pathogenesis and in developing biomarkers and therapeutic strategies. ATXN7 is a bona fide subunit of the multiprotein SAGA complex, a transcriptional coactivator harboring chromatin remodeling activities, and plays a role in the differentiation of photoreceptors and Purkinje neurons, two highly vulnerable neuronal cell types in SCA7. Polyglutamine expansion in ATXN7 causes its misfolding and intranuclear accumulation, leading to changes in interactions with native partners and/or partners sequestration in insoluble nuclear inclusions. Studies of cellular and animal models of SCA7 have been crucial to unveil pathomechanistic aspects of the disease, including gene deregulation, mitochondrial and metabolic dysfunctions, cell and non-cell autonomous protein toxicity, loss of neuronal identity, and cell death mechanisms. However, a better understanding of the principal molecular mechanisms by which mutant ATXN7 elicits neurotoxicity, and how interconnected pathogenic cascades lead to neurodegeneration is needed for the development of effective therapies. At present, therapeutic strategies using nucleic acid-based molecules to silence mutant ATXN7 gene expression are under development for SCA7.
Collapse
Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France
| | - Yvon Trottier
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France.
| |
Collapse
|
11
|
Buijsen RAM, Toonen LJA, Gardiner SL, van Roon-Mom WMC. Genetics, Mechanisms, and Therapeutic Progress in Polyglutamine Spinocerebellar Ataxias. Neurotherapeutics 2019; 16:263-286. [PMID: 30607747 PMCID: PMC6554265 DOI: 10.1007/s13311-018-00696-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative disorders characterized by degeneration of the cerebellum and its connections. All ADCAs have progressive ataxia as their main clinical feature, frequently accompanied by dysarthria and oculomotor deficits. The most common spinocerebellar ataxias (SCAs) are 6 polyglutamine (polyQ) SCAs. These diseases are all caused by a CAG repeat expansion in the coding region of a gene. Currently, no curative treatment is available for any of the polyQ SCAs, but increasing knowledge on the genetics and the pathological mechanisms of these polyQ SCAs has provided promising therapeutic targets to potentially slow disease progression. Potential treatments can be divided into pharmacological and gene therapies that target the toxic downstream effects, gene therapies that target the polyQ SCA genes, and stem cell replacement therapies. Here, we will provide a review on the genetics, mechanisms, and therapeutic progress in polyglutamine spinocerebellar ataxias.
Collapse
Affiliation(s)
- Ronald A M Buijsen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - Lodewijk J A Toonen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Sarah L Gardiner
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
- Department of Neurology, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | | |
Collapse
|