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Scott V, Delatycki MB, Tai G, Corben LA. New and Emerging Drug and Gene Therapies for Friedreich Ataxia. CNS Drugs 2024; 38:791-805. [PMID: 39115603 PMCID: PMC11377510 DOI: 10.1007/s40263-024-01113-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/18/2024] [Indexed: 09/06/2024]
Abstract
The life shortening nature of Friedreich Ataxia (FRDA) demands the search for therapies that can delay, stop or reverse its relentless trajectory. This review provides a contemporary position of drug and gene therapies for FRDA currently in phase 1 clinical trials and beyond. Despite significant scientific advances in the specificity of both compounds and targets developed and investigated, challenges remain for the advancement of treatments in a limited recruitment population. Currently therapies focus on reducing oxidative stress and improving mitochondrial function, modulating frataxin controlled metabolic pathways and gene replacement and editing. Approval of omaveloxolone, the first treatment for individuals with FRDA aged 16 years and over, has created much excitement for both those living with FRDA and those that care for them. The process of approval of omaveloxolone by the US Food and Drug Administration highlighted the importance of sensitive outcome measures and the significant role of data from natural history studies.
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Affiliation(s)
- Varlli Scott
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Martin B Delatycki
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
- Victorian Clinical Genetics Service, Parkville, VIC, Australia
| | - Geneieve Tai
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia
| | - Louise A Corben
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Parkville, VIC, 3052, Australia.
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia.
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia.
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2
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Kioutchoukova IP, Foster DT, Thakkar RN, Foreman MA, Burgess BJ, Toms RM, Molina Valero EE, Lucke-Wold B. Neurologic orphan diseases: Emerging innovations and role for genetic treatments. World J Exp Med 2023; 13:59-74. [PMID: 37767543 PMCID: PMC10520757 DOI: 10.5493/wjem.v13.i4.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/16/2023] [Accepted: 08/11/2023] [Indexed: 09/15/2023] Open
Abstract
Orphan diseases are rare diseases that affect less than 200000 individuals within the United States. Most orphan diseases are of neurologic and genetic origin. With the current advances in technology, more funding has been devoted to developing therapeutic agents for patients with these conditions. In our review, we highlight emerging options for patients with neurologic orphan diseases, specifically including diseases resulting in muscular deterioration, epilepsy, seizures, neurodegenerative movement disorders, inhibited cognitive development, neuron deterioration, and tumors. After extensive literature review, gene therapy offers a promising route for the treatment of neurologic orphan diseases. The use of clustered regularly interspaced palindromic repeats/Cas9 has demonstrated positive results in experiments investigating its role in several diseases. Additionally, the use of adeno-associated viral vectors has shown improvement in survival, motor function, and developmental milestones, while also demonstrating reversal of sensory ataxia and cardiomyopathy in Friedreich ataxia patients. Antisense oligonucleotides have also been used in some neurologic orphan diseases with positive outcomes. Mammalian target of rapamycin inhibitors are currently being investigated and have reduced abnormal cell growth, proliferation, and angiogenesis. Emerging innovations and the role of genetic treatments open a new window of opportunity for the treatment of neurologic orphan diseases.
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Affiliation(s)
| | - Devon T Foster
- Florida International University Herbert Wertheim College of Medicine, Florida International University Herbert Wertheim College of Medicine, Miami, FL 33199, United States
| | - Rajvi N Thakkar
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Marco A Foreman
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Brandon J Burgess
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Rebecca M Toms
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | | | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32611, United States
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3
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Bouchard C, Gérard C, Yanyabé SGF, Majeau N, Aloui M, Buisson G, Yameogo P, Couture V, Tremblay JP. Finding an Appropriate Mouse Model to Study the Impact of a Treatment for Friedreich Ataxia on the Behavioral Phenotype. Genes (Basel) 2023; 14:1654. [PMID: 37628705 PMCID: PMC10454134 DOI: 10.3390/genes14081654] [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: 07/18/2023] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Friedreich ataxia (FRDA) is a progressive neurodegenerative disease caused by a GAA repeat in the intron 1 of the frataxin gene (FXN) leading to a lower expression of the frataxin protein. The YG8sR mice are Knock-Out (KO) for their murine frataxin gene but contain a human frataxin transgene derived from an FRDA patient with 300 GAA repeats. These mice are used as a FRDA model but even with a low frataxin concentration, their phenotype is mild. We aimed to find an optimized mouse model with a phenotype comparable to the human patients to study the impact of therapy on the phenotype. We compared two mouse models: the YG8sR injected with an AAV. PHP.B coding for a shRNA targeting the human frataxin gene and the YG8-800, a new mouse model with a human transgene containing 800 GAA repeats. Both mouse models were compared to Y47R mice containing nine GAA repeats that were considered healthy mice. Behavior tests (parallel rod floor apparatus, hanging test, inverted T beam, and notched beam test) were carried out from 2 to 11 months and significant differences were noticed for both YG8sR mice injected with an anti-FXN shRNA and the YG8-800 mice compared to healthy mice. In conclusion, YG8sR mice have a slight phenotype, and injecting them with an AAV-PHP.B expressing an shRNA targeting frataxin does increase their phenotype. The YG8-800 mice have a phenotype comparable to the human ataxic phenotype.
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Affiliation(s)
- Camille Bouchard
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Catherine Gérard
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Solange Gni-fiene Yanyabé
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Nathalie Majeau
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Malek Aloui
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
| | - Gabrielle Buisson
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
| | - Pouiré Yameogo
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Vanessa Couture
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
| | - Jacques P. Tremblay
- Centre de Recherche du CHU, Québec-Université Laval, Québec, QC G1V 4G2, Canada (N.M.); (M.A.); (G.B.)
- Département de Médecine Moléculaire, l’Université Laval Québec, Québec, QC G1V 4G2, Canada
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Yaméogo P, Gérard C, Majeau N, Tremblay JP. Removal of the GAA repeat in the heart of a Friedreich's ataxia mouse model using CjCas9. Gene Ther 2023; 30:612-619. [PMID: 36781946 DOI: 10.1038/s41434-023-00387-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/12/2023] [Accepted: 01/27/2023] [Indexed: 02/15/2023]
Abstract
Most Friedreich ataxia (FRDA) cases are caused by the elongation of the GAA repeat (GAAr) sequence in the first intron of the FXN gene, leading to a decrease of the frataxin protein expression. Deletion of this GAAr with CRISPR/Cas9 technology leads to an increase in frataxin expression in vitro. We are therefore aiming to develop FRDA treatment based on the deletion of GAAr with CRISPR/Cas9 technology using a single AAV expressing a small Cas9 (CjCas9) and two single guide RNAs (sgRNAs) targeting the FXN gene. This AAV was intraperitoneally administrated to YG8sR (250-300 GAAr) and to YG8-800 (800 GAAr) mice. DNA and RNA were extracted from different organs a month later. PCR amplification of part of intron 1 of the FXN gene detected some GAAr deletion in some cells in heart and liver of both mouse models, but the editing rate was not sufficient to cause an increase in frataxin mRNA in the heart. However, the correlation observed between the editing rate and the distribution of AAV suggests a possible therapy based on the removal of the GAAr with a better delivery tool of the CRISPR/Cas9 system.
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Affiliation(s)
- Pouiré Yaméogo
- Centre de Recherche du CHU de Québec-Université Laval, Québec city, QC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec city, QC, Canada
| | - Catherine Gérard
- Centre de Recherche du CHU de Québec-Université Laval, Québec city, QC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec city, QC, Canada
| | - Nathalie Majeau
- Centre de Recherche du CHU de Québec-Université Laval, Québec city, QC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec city, QC, Canada
| | - Jacques P Tremblay
- Centre de Recherche du CHU de Québec-Université Laval, Québec city, QC, Canada.
- Département de Médecine Moléculaire, Université Laval, Québec city, QC, Canada.
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Advancement in CRISPR/Cas9 Technology to Better Understand and Treat Neurological Disorders. Cell Mol Neurobiol 2023; 43:1019-1035. [PMID: 35751791 DOI: 10.1007/s10571-022-01242-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/09/2022] [Indexed: 11/26/2022]
Abstract
Neurological disorders have complicated pathophysiology that may involve several genetic mutations. Conventional treatment has limitations as they only treat apparent symptoms. Although, personalized medicine is emerging as a promising neuro-intervention, lack of precision is the major pitfall. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system is evolving as a technological platform that may overcome the therapeutic limitations towards precision medicine. In the future, targeting genes in neurological disorders may be the mainstay of modern therapy. The present review on CRISPR/Cas9 and its application in various neurological disorders may provide a platform for its future clinical relevance towards developing precise and personalized medicine.
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Santos C, Malheiro S, Correia M, Damásio J. Gene Suppression Therapies in Hereditary Cerebellar Ataxias: A Systematic Review of Animal Studies. Cells 2023; 12:cells12071037. [PMID: 37048110 PMCID: PMC10093402 DOI: 10.3390/cells12071037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 03/30/2023] Open
Abstract
Introduction: Hereditary cerebellar ataxias (HCAs) are a heterogenous group of neurodegenerative disorders associated with severe disability. Treatment options are limited and overall restricted to symptomatic approaches, leading to poor prognoses. In recent years, there has been extensive research on gene suppression therapies (GSTs) as a new hope for disease-modifying strategies. In this article, we aim to perform a review of in vivo studies investigating the efficacy and safety profile of GSTs in HCAs. Methods: A structured PubMed® search on GSTs in HCAs from January 1993 up to October 2020 was performed. Inclusion and exclusion criteria were defined, and the selection process was conducted accordingly. The screening process was independently carried out by two authors and was initially based on title and abstract, followed by full-text reading. The risk-of-bias assessment was performed with SYRCLE’s tool. A data extraction sheet was created to collect relevant information from each selected article. Results: The initial search yielded 262 papers, of which 239 were excluded. An additional article was obtained following reference scrutiny, resulting in a total of 24 articles for final analysis. Most studies were not clear on the tools used to assess bias. In SCA1, SCA2, MJD/SCA3 and SCA7, RNA interference (iRNA) and antisense oligonucleotide (ASO) therapies proved to be well tolerated and effective in suppressing mutant proteins, improving neuropathological features and the motor phenotype. In SCA6, the phenotype was improved, but no investigation of adverse effects was performed. In FRDA, only the suppression efficacy of the electroporation of the clustered regularly interspaced short palindromic repeats associated with Cas9 enzyme system (CRISPR-Cas9) system was tested and confirmed. Conclusion: The literature reviewed suggests that GSTs are well tolerated and effective in suppressing the targeted proteins, improving neuropathological features and the motor phenotype in vivo. Nonetheless, there is no guarantee that these results are free of bias. Moreover, further investigation is still needed to clarify the GST effect on HCAs such as FRDA, SCA6 and SCA2.
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Dhuriya YK, Naik AA. CRISPR: a tool with potential for genomic reprogramming in neurological disorders. Mol Biol Rep 2023; 50:1845-1856. [PMID: 36507966 DOI: 10.1007/s11033-022-08136-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/17/2022] [Indexed: 12/14/2022]
Abstract
The intricate neural circuitry of the brain necessitates precise and synchronized transcriptional programs. Any disturbance during embryonic or adult development, whether caused by genetic or environmental factors, may result in refractory and recurrent neurological disorders. Inadequate knowledge of the pathogenic mechanisms underlying neurological disorders is the primary obstacle to the development of effective treatments, necessitating the development of alternative therapeutic approaches to identify rational molecular targets. Recently, with the evolution of CRISPR-Cas9 technology, an engineered RNA system provides precise and highly effective correction or silencing of disease-causing mutations by modulating expression and thereby avoiding the limitations of the RNA interference strategy. This article discusses the CRISPR-Cas9 technology, its mechanisms, and the limitations of the new technology. We provide a glimpse of how the far-reaching implications of CRISPR can open new avenues for the development of tools to combat neurological disorders, as well as a review of recent attempts by neuroscientists to launch therapeutic correction.
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Affiliation(s)
| | - Aijaz A Naik
- National Institute of Mental Health (NIMH), Bethesda, USA.
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Kalef-Ezra E, Edzeamey FJ, Valle A, Khonsari H, Kleine P, Oggianu C, Al-Mahdawi S, Pook MA, Anjomani Virmouni S. A new FRDA mouse model [ Fxn null:YG8s(GAA) > 800] with more than 800 GAA repeats. Front Neurosci 2023; 17:930422. [PMID: 36777637 PMCID: PMC9909538 DOI: 10.3389/fnins.2023.930422] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 01/04/2023] [Indexed: 01/27/2023] Open
Abstract
Introduction Friedreich's ataxia (FRDA) is an inherited recessive neurodegenerative disorder caused by a homozygous guanine-adenine-adenine (GAA) repeat expansion within intron 1 of the FXN gene, which encodes the essential mitochondrial protein frataxin. There is still no effective therapy for FRDA, therefore the development of optimal cell and animal models of the disease is one of the priorities for preclinical therapeutic testing. Methods We obtained the latest FRDA humanized mouse model that was generated on the basis of our previous YG8sR, by Jackson laboratory [YG8JR, Fxn null:YG8s(GAA) > 800]. We characterized the behavioral, cellular, molecular and epigenetics properties of the YG8JR model, which has the largest GAA repeat sizes compared to all the current FRDA mouse models. Results We found statistically significant behavioral deficits, together with reduced levels of frataxin mRNA and protein, and aconitase activity in YG8JR mice compared with control Y47JR mice. YG8JR mice exhibit intergenerational GAA repeat instability by the analysis of parent and offspring tissue samples. Somatic GAA repeat instability was also detected in individual brain and cerebellum tissue samples. In addition, increased DNA methylation of CpG U13 was identified in FXN GAA repeat region in the brain, cerebellum, and heart tissues. Furthermore, we show decreased histone H3K9 acetylation and increased H3K9 methylation of YG8JR cerebellum tissues within the FXN gene, upstream and downstream of the GAA repeat region compared to Y47JR controls. Discussion These studies provide a detailed characterization of the GAA repeat expansion-based YG8JR transgenic mouse models that will help investigations of FRDA disease mechanisms and therapy.
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Affiliation(s)
- Ester Kalef-Ezra
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Fred Jonathan Edzeamey
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Adamo Valle
- Energy Metabolism and Nutrition, Research Institute of Health Sciences (IUNICS), University of Balearic Islands, Palma, Spain,Health Research Institute of Balearic Islands (IdISBa), Palma, Spain,Biomedical Research Networking Center for Physiopathology of Obesity and Nutrition (CIBERobn CB06/03/0043), Instituto de Salud Carlos III, Madrid, Spain
| | - Hassan Khonsari
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Paula Kleine
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Carlo Oggianu
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Sahar Al-Mahdawi
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Mark A. Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Sara Anjomani Virmouni
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom,*Correspondence: Sara Anjomani Virmouni,
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9
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Gérard C, Archambault AF, Bouchard C, Tremblay JP. A promising mouse model for Friedreich Ataxia progressing like human patients. Behav Brain Res 2023; 436:114107. [DOI: 10.1016/j.bbr.2022.114107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 11/27/2022]
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10
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Masnovo C, Lobo AF, Mirkin SM. Replication dependent and independent mechanisms of GAA repeat instability. DNA Repair (Amst) 2022; 118:103385. [PMID: 35952488 PMCID: PMC9675320 DOI: 10.1016/j.dnarep.2022.103385] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 11/20/2022]
Abstract
Trinucleotide repeat instability is a driver of human disease. Large expansions of (GAA)n repeats in the first intron of the FXN gene are the cause Friedreich's ataxia (FRDA), a progressive degenerative disorder which cannot yet be prevented or treated. (GAA)n repeat instability arises during both replication-dependent processes, such as cell division and intergenerational transmission, as well as in terminally differentiated somatic tissues. Here, we provide a brief historical overview on the discovery of (GAA)n repeat expansions and their association to FRDA, followed by recent advances in the identification of triplex H-DNA formation and replication fork stalling. The main body of this review focuses on the last decade of progress in understanding the mechanism of (GAA)n repeat instability during DNA replication and/or DNA repair. We propose that the discovery of additional mechanisms of (GAA)n repeat instability can be achieved via both comparative approaches to other repeat expansion diseases and genome-wide association studies. Finally, we discuss the advances towards FRDA prevention or amelioration that specifically target (GAA)n repeat expansions.
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Affiliation(s)
- Chiara Masnovo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Ayesha F Lobo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02155, USA.
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11
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Sivakumar A, Cherqui S. Advantages and Limitations of Gene Therapy and Gene Editing for Friedreich's Ataxia. Front Genome Ed 2022; 4:903139. [PMID: 35663795 PMCID: PMC9157421 DOI: 10.3389/fgeed.2022.903139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 04/21/2022] [Indexed: 12/26/2022] Open
Abstract
Friedreich's ataxia (FRDA) is an inherited, multisystemic disorder predominantly caused by GAA hyper expansion in intron 1 of frataxin (FXN) gene. This expansion mutation transcriptionally represses FXN, a mitochondrial protein that is required for iron metabolism and mitochondrial homeostasis, leading to neurodegerative and cardiac dysfunction. Current therapeutic options for FRDA are focused on improving mitochondrial function and increasing frataxin expression through pharmacological interventions but are not effective in delaying or preventing the neurodegeneration in clinical trials. Recent research on in vivo and ex vivo gene therapy methods in FRDA animal and cell models showcase its promise as a one-time therapy for FRDA. In this review, we provide an overview on the current and emerging prospects of gene therapy for FRDA, with specific focus on advantages of CRISPR/Cas9-mediated gene editing of FXN as a viable option to restore endogenous frataxin expression. We also assess the potential of ex vivo gene editing in hematopoietic stem and progenitor cells as a potential autologous transplantation therapeutic option and discuss its advantages in tackling FRDA-specific safety aspects for clinical translation.
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Affiliation(s)
| | - Stephanie Cherqui
- Division of Genetics, Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
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12
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Mechanistic and Therapeutic Insights into Ataxic Disorders with Pentanucleotide Expansions. Cells 2022; 11:cells11091567. [PMID: 35563872 PMCID: PMC9099484 DOI: 10.3390/cells11091567] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/01/2023] Open
Abstract
Pentanucleotide expansion diseases constitute a special class of neurodegeneration. The repeat expansions occur in non-coding regions, have likely arisen from Alu elements, and often result in autosomal dominant or recessive phenotypes with underlying cerebellar neuropathology. When transcribed (potentially bidirectionally), the expanded RNA forms complex secondary and tertiary structures that can give rise to RNA-mediated toxicity, including protein sequestration, pentapeptide synthesis, and mRNA dysregulation. Since several of these diseases have recently been discovered, our understanding of their pathological mechanisms is limited, and their therapeutic interventions underexplored. This review aims to highlight new in vitro and in vivo insights into these incurable diseases.
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13
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Nambiar TS, Baudrier L, Billon P, Ciccia A. CRISPR-based genome editing through the lens of DNA repair. Mol Cell 2022; 82:348-388. [PMID: 35063100 PMCID: PMC8887926 DOI: 10.1016/j.molcel.2021.12.026] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 01/22/2023]
Abstract
Genome editing technologies operate by inducing site-specific DNA perturbations that are resolved by cellular DNA repair pathways. Products of genome editors include DNA breaks generated by CRISPR-associated nucleases, base modifications induced by base editors, DNA flaps created by prime editors, and integration intermediates formed by site-specific recombinases and transposases associated with CRISPR systems. Here, we discuss the cellular processes that repair CRISPR-generated DNA lesions and describe strategies to obtain desirable genomic changes through modulation of DNA repair pathways. Advances in our understanding of the DNA repair circuitry, in conjunction with the rapid development of innovative genome editing technologies, promise to greatly enhance our ability to improve food production, combat environmental pollution, develop cell-based therapies, and cure genetic and infectious diseases.
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Affiliation(s)
- Tarun S Nambiar
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lou Baudrier
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N1, Canada
| | - Pierre Billon
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N1, Canada.
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA.
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Yang W, Thompson B, Kwa FAA. Molecular approaches for the treatment and prevention of Friedreich's ataxia. Drug Discov Today 2021; 27:866-880. [PMID: 34763067 DOI: 10.1016/j.drudis.2021.11.003] [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: 07/28/2021] [Revised: 10/01/2021] [Accepted: 11/01/2021] [Indexed: 12/11/2022]
Abstract
Friedreich's ataxia (FRDA) is caused by an intronic guanine-adenine-adenine (GAA) trinucleotide expansion in the gene encoding the frataxin protein (FXN). This triggers the transcriptional silencing of the fratxin gene (FXN) and subsequent FXN deficiency in affected cells, which accounts for the multisystemic symptoms of this condition. Current management strategies aim for symptomatic relief and no treatments can prevent disease onset or progression. Thus, research efforts have focused on targeting the molecular pathways that silence FXN and downstream pathological processes. However, progression of potential therapies into clinical use has been hindered by inconclusive clinical trials because of the small patient sample size associated with the low prevalence of this condition. Here, we discuss various molecular approaches and explore their therapeutic potential to alter the course of this progressive condition.
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Affiliation(s)
- Wenyao Yang
- School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Bruce Thompson
- School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Faith A A Kwa
- School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
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15
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Yaméogo P, Duchêne BL, Majeau N, Tremblay JP. CRISPR-SCReT (CRISPR-Stop Codon Read Through) method to control Cas9 expression for gene editing. Gene Ther 2021; 29:171-177. [PMID: 34593991 DOI: 10.1038/s41434-021-00297-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 12/28/2022]
Abstract
CRISPR/Cas9 has paved the way for the development of therapies that correct genetic mutations. However, constitutive expression of the Cas9 gene can increase off-target mutations and induce an immune response against the Cas9 protein. To limit the time during which the Cas9 nuclease is expressed, we proposed a simple drug inducible system. The approach consists of introducing a premature termination codon (PTC) in the Cas9 gene and subsequently treating with an aminoglycoside drug, which allows readthrough of the complete protein. To validate that system, HEK293T cells were co-transfected with a PX458 plasmid, which was mutated to introduce a PTC in the SpCas9 gene and two sgRNAs targeting the DMD gene (exons 50 and 54). Cells were treated with different doses of geneticin (G418) for 48 h. Western blot confirmed that the Cas9 protein expression, which was shut down by the PTC mutation, can be induced by the drug. The hybrid exon 50-54 formed by the deletion of part of the DMD gene was detected by PCR only in the cells treated with G418. The approach was also used successfully with CjCas9 to edit the FXN gene. Our results show that it is possible to control SpCas9 and CjCas9 expression by CRISPR-SCReT (CRISPR-Stop Codon Read Through) method.
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Affiliation(s)
- Pouiré Yaméogo
- Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
| | - Benjamin L Duchêne
- Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
| | - Nathalie Majeau
- Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.,Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
| | - Jacques P Tremblay
- Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada. .,Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada.
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16
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Perlman SL. Update on the Treatment of Ataxia: Medication and Emerging Therapies. Neurotherapeutics 2020; 17:1660-1664. [PMID: 33021724 PMCID: PMC7851298 DOI: 10.1007/s13311-020-00941-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
Abstract
While rehabilitation therapies always help patients with ataxia, there are currently no FDA-approved treatments for ataxia. Medications are available to treat symptoms that may complicate an ataxic illness, e.g., tremor, myoclonus, dystonia, and rigidity, which are discussed elsewhere in this volume. Spasticity, pain, fatigue, depression, sleep disturbances, cognitive decline, and bowel and bladder dysfunction, if they occur, all have multiple available drugs and therapies for symptomatic use. There is also an extensive literature on off-label uses of various medications to improve imbalance. The pipeline of emerging therapies for symptomatic and possible disease-modifying management of ataxia gives hope that we will soon see the first of many FDA-approved drugs for ataxic illnesses.
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Affiliation(s)
- Susan L Perlman
- Clinical Professor of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.
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17
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Mazzara PG, Muggeo S, Luoni M, Massimino L, Zaghi M, Valverde PTT, Brusco S, Marzi MJ, Palma C, Colasante G, Iannielli A, Paulis M, Cordiglieri C, Giannelli SG, Podini P, Gellera C, Taroni F, Nicassio F, Rasponi M, Broccoli V. Frataxin gene editing rescues Friedreich's ataxia pathology in dorsal root ganglia organoid-derived sensory neurons. Nat Commun 2020; 11:4178. [PMID: 32826895 PMCID: PMC7442818 DOI: 10.1038/s41467-020-17954-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 07/28/2020] [Indexed: 12/31/2022] Open
Abstract
Friedreich's ataxia (FRDA) is an autosomal-recessive neurodegenerative and cardiac disorder which occurs when transcription of the FXN gene is silenced due to an excessive expansion of GAA repeats into its first intron. Herein, we generate dorsal root ganglia organoids (DRG organoids) by in vitro differentiation of human iPSCs. Bulk and single-cell RNA sequencing show that DRG organoids present a transcriptional signature similar to native DRGs and display the main peripheral sensory neuronal and glial cell subtypes. Furthermore, when co-cultured with human intrafusal muscle fibers, DRG organoid sensory neurons contact their peripheral targets and reconstitute the muscle spindle proprioceptive receptors. FRDA DRG organoids model some molecular and cellular deficits of the disease that are rescued when the entire FXN intron 1 is removed, and not with the excision of the expanded GAA tract. These results strongly suggest that removal of the repressed chromatin flanking the GAA tract might contribute to rescue FXN total expression and fully revert the pathological hallmarks of FRDA DRG neurons.
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Affiliation(s)
- Pietro Giuseppe Mazzara
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
- Department of Neuroscience, The Scripps Research Institute, 92037, La Jolla, CA, USA
| | - Sharon Muggeo
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Mirko Luoni
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Luca Massimino
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Mattia Zaghi
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | | | - Simone Brusco
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Matteo Jacopo Marzi
- Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia (IIT), 20139, Milan, Italy
| | - Cecilia Palma
- Department of Electronics, Information & Bioengineering, Politecnico di Milano, 20133, Milan, Italy
| | - Gaia Colasante
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Angelo Iannielli
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129, Milan, Italy
| | - Marianna Paulis
- Humanitas Clinical and Research Center, 20089, Rozzano, Milano, Italy
| | - Chiara Cordiglieri
- National Institute of Molecular Genetics "Romeo e Enrica Invernizzi" - INGM, 20122, Milan, Italy
| | - Serena Gea Giannelli
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Paola Podini
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133, Milan, Italy
| | - Franco Taroni
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133, Milan, Italy
| | - Francesco Nicassio
- Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia (IIT), 20139, Milan, Italy
| | - Marco Rasponi
- Department of Electronics, Information & Bioengineering, Politecnico di Milano, 20133, Milan, Italy
| | - Vania Broccoli
- Division of Neuroscience, San Raffaele Scientific Institute, 20132, Milan, Italy.
- National Research Council (CNR), Institute of Neuroscience, 20129, Milan, Italy.
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18
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Demidov VV. Site-specifically deuterated essential lipids as new drugs against neuronal, retinal and vascular degeneration. Drug Discov Today 2020; 25:1469-1476. [DOI: 10.1016/j.drudis.2020.03.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/07/2020] [Accepted: 03/23/2020] [Indexed: 01/10/2023]
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19
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CRISPR-Cas9 system: A genome-editing tool with endless possibilities. J Biotechnol 2020; 319:36-53. [DOI: 10.1016/j.jbiotec.2020.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/30/2020] [Accepted: 05/14/2020] [Indexed: 12/27/2022]
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20
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Li J, Li Y, Wang J, Gonzalez TJ, Asokan A, Napierala JS, Napierala M. Defining Transcription Regulatory Elements in the Human Frataxin Gene: Implications for Gene Therapy. Hum Gene Ther 2020; 31:839-851. [PMID: 32527155 PMCID: PMC7462031 DOI: 10.1089/hum.2020.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022] Open
Abstract
Friedreich's ataxia (FRDA) is the most common inherited form of ataxia in humans. It is caused by severe downregulation of frataxin (FXN) expression instigated by hyperexpansion of the GAA repeats located in intron 1 of the FXN gene. Despite numerous studies focused on identifying compounds capable of stimulating FXN expression, current knowledge regarding cis-regulatory elements involved in FXN gene expression is lacking. Using a combination of episomal and genome-integrated constructs, we defined a minimal endogenous promoter sequence required to efficiently drive FXN expression in human cells. We generated 19 constructs varying in length of the DNA sequences upstream and downstream of the ATG start codon. Using transient transfection, we evaluated the capability of these constructs to drive FXN expression. These analyses allowed us to identify a region of the gene indispensable for FXN expression. Subsequently, selected constructs containing the FXN expression control regions of varying lengths were site specifically integrated into the genome of HEK293T and human-induced pluripotent stem cells (iPSCs). FXN expression was detected in iPSCs and persisted after differentiation to neuronal and cardiac cells, indicating lineage independent function of defined regulatory DNA sequences. Finally, based on these results, we generated AAV encoding miniFXN genes and demonstrated in vivo FXN expression in mice. Results of these studies identified FXN sequences necessary to express FXN in human and mouse cells and provided rationale for potential use of endogenous FXN sequence in gene therapy strategies for FRDA.
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Affiliation(s)
- Jixue Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jun Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Trevor J. Gonzalez
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Aravind Asokan
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jill S. Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
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21
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Rocca CJ, Rainaldi JN, Sharma J, Shi Y, Haquang JH, Luebeck J, Mali P, Cherqui S. CRISPR-Cas9 Gene Editing of Hematopoietic Stem Cells from Patients with Friedreich's Ataxia. Mol Ther Methods Clin Dev 2020; 17:1026-1036. [PMID: 32462051 PMCID: PMC7240056 DOI: 10.1016/j.omtm.2020.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 04/27/2020] [Indexed: 12/26/2022]
Abstract
Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by expansion of GAA repeats in intron 1 of the frataxin (FXN) gene, leading to significant decreased expression of frataxin, a mitochondrial iron-binding protein. We previously reported that syngeneic hematopoietic stem and progenitor cell (HSPC) transplantation prevented neurodegeneration in the FRDA mouse model YG8R. We showed that the mechanism of rescue was mediated by the transfer of the functional frataxin from HSPC-derived microglia/macrophage cells to neurons/myocytes. In this study, we report the first step toward an autologous HSPC transplantation using the CRISPR-Cas9 system for FRDA. We first identified a pair of CRISPR RNAs (crRNAs) that efficiently removes the GAA expansions in human FRDA lymphoblasts, restoring the non-pathologic level of frataxin expression and normalizing mitochondrial activity. We also optimized the gene-editing approach in HSPCs isolated from healthy and FRDA patients' peripheral blood and demonstrated normal hematopoiesis of gene-edited cells in vitro and in vivo. The procedure did not induce cellular toxic effect or major off-target events, but a p53-mediated cell proliferation delay was observed in the gene-edited cells. This study provides the foundation for the clinical translation of autologous transplantation of gene-corrected HSPCs for FRDA.
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Affiliation(s)
- Celine J. Rocca
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph N. Rainaldi
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jay Sharma
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yanmeng Shi
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph H. Haquang
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jens Luebeck
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Prashant Mali
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephanie Cherqui
- Division of Genetics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
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22
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Khristich AN, Mirkin SM. On the wrong DNA track: Molecular mechanisms of repeat-mediated genome instability. J Biol Chem 2020; 295:4134-4170. [PMID: 32060097 PMCID: PMC7105313 DOI: 10.1074/jbc.rev119.007678] [Citation(s) in RCA: 160] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Expansions of simple tandem repeats are responsible for almost 50 human diseases, the majority of which are severe, degenerative, and not currently treatable or preventable. In this review, we first describe the molecular mechanisms of repeat-induced toxicity, which is the connecting link between repeat expansions and pathology. We then survey alternative DNA structures that are formed by expandable repeats and review the evidence that formation of these structures is at the core of repeat instability. Next, we describe the consequences of the presence of long structure-forming repeats at the molecular level: somatic and intergenerational instability, fragility, and repeat-induced mutagenesis. We discuss the reasons for gender bias in intergenerational repeat instability and the tissue specificity of somatic repeat instability. We also review the known pathways in which DNA replication, transcription, DNA repair, and chromatin state interact and thereby promote repeat instability. We then discuss possible reasons for the persistence of disease-causing DNA repeats in the genome. We describe evidence suggesting that these repeats are a payoff for the advantages of having abundant simple-sequence repeats for eukaryotic genome function and evolvability. Finally, we discuss two unresolved fundamental questions: (i) why does repeat behavior differ between model systems and human pedigrees, and (ii) can we use current knowledge on repeat instability mechanisms to cure repeat expansion diseases?
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Affiliation(s)
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, Massachusetts 02155.
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23
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Srivastava A, Swarup V, Kumar V, Faruq M, Singh H, Singh I. CRISPR/Cas9 technology in neurological disorders: An update for clinicians. ANNALS OF MOVEMENT DISORDERS 2020. [DOI: 10.4103/aomd.aomd_39_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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24
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Raikwar SP, Kikkeri NS, Sakuru R, Saeed D, Zahoor H, Premkumar K, Mentor S, Thangavel R, Dubova I, Ahmed ME, Selvakumar GP, Kempuraj D, Zaheer S, Iyer SS, Zaheer A. Next Generation Precision Medicine: CRISPR-mediated Genome Editing for the Treatment of Neurodegenerative Disorders. J Neuroimmune Pharmacol 2019; 14:608-641. [PMID: 31011884 PMCID: PMC8211357 DOI: 10.1007/s11481-019-09849-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 03/29/2019] [Indexed: 12/13/2022]
Abstract
Despite significant advancements in the field of molecular neurobiology especially neuroinflammation and neurodegeneration, the highly complex molecular mechanisms underlying neurodegenerative diseases remain elusive. As a result, the development of the next generation neurotherapeutics has experienced a considerable lag phase. Recent advancements in the field of genome editing offer a new template for dissecting the precise molecular pathways underlying the complex neurodegenerative disorders. We believe that the innovative genome and transcriptome editing strategies offer an excellent opportunity to decipher novel therapeutic targets, develop novel neurodegenerative disease models, develop neuroimaging modalities, develop next-generation diagnostics as well as develop patient-specific precision-targeted personalized therapies to effectively treat neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, Frontotemporal dementia etc. Here, we review the latest developments in the field of CRISPR-mediated genome editing and provide unbiased futuristic insights regarding its translational potential to improve the treatment outcomes and minimize financial burden. However, despite significant advancements, we would caution the scientific community that since the CRISPR field is still evolving, currently we do not know the full spectrum of CRISPR-mediated side effects. In the wake of the recent news regarding CRISPR-edited human babies being born in China, we urge the scientific community to maintain high scientific and ethical standards and utilize CRISPR for developing in vitro disease in a dish model, in vivo testing in nonhuman primates and lower vertebrates and for the development of neurotherapeutics for the currently incurable neurodegenerative disorders. Graphical Abstract.
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Affiliation(s)
- Sudhanshu P Raikwar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Nidhi S Kikkeri
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Ragha Sakuru
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Daniyal Saeed
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Haris Zahoor
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Keerthivaas Premkumar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Shireen Mentor
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- Department of Medical Biosciences, University of the Western Cape, Bellville, 7535, Republic of South Africa
| | - Ramasamy Thangavel
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Iuliia Dubova
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Mohammad Ejaz Ahmed
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Govindhasamy P Selvakumar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Duraisamy Kempuraj
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Smita Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
| | - Shankar S Iyer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA
| | - Asgar Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, M741A Medical Science Building, 1 Hospital Drive, Columbia, MO, 65211, USA.
- U.S. Department of Veterans Affairs, Harry S. Truman Memorial Veteran's Hospital, Columbia, MO, USA.
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25
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Weng L, Wang Q, Yu S, Yang X, Lynch DR, Mesaros C, Blair IA. Evaluation of antibodies for western blot analysis of frataxin protein isoforms. J Immunol Methods 2019; 474:112629. [PMID: 31279523 PMCID: PMC6829029 DOI: 10.1016/j.jim.2019.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/21/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022]
Abstract
Frataxin is the protein that is down-regulated in Friedreich ataxia (FRDA), an autosomal recessive genetic disease caused by an intronic GAA repeat expansion in intron-1 of the FXN gene. The GAA repeats result in epigenetic silencing of the FXN gene and reduced expression of the cytosolic full-length frataxin (1-210) protein. Full length frataxin translocates to the mitochondria, leading to formation of mature frataxin (81-210) formed by cleavage of the mitochondrial targeting sequence at K-80 of the full-length protein. There are currently no approved treatments for FRDA, although experimental approaches involving up-regulation or replacement of mature frataxin protein through numerous approaches are being tested. Many of the pre-clinical studies of these experimental approaches are conducted in mouse and monkey models as well as in human cell lines. Consequently, well-validated antibodies are required for use in western blot analysis to determine whether levels of various forms of frataxin have been increased. Here we examined the specificity of five commercially available anti-frataxin antibodies and determined whether they detect mature frataxin in mouse heart tissue. Four protein standards of monkey, human, and mouse frataxin as well as mouse heart tissue were examined using polyacrylamide gel electrophoresis (PAGE) in combination with western blot analysis. One antibody failed to detect any of the frataxin standards or endogenous frataxin in mouse heart tissue. Three of the antibodies detected a protein in mouse heart tissue that ran slightly faster on PAGE (at 23.4 kDa) to that predicted for full-length frataxin (23.9 kDa). One antibody detected all four frataxin standards as well as endogenous mouse mature frataxin in mouse tissue. Significantly, this antibody, which will be useful for monitoring mature frataxin levels in monkey, human, and mouse tissues, did not detect a protein in mouse heart tissue at 23.4 kDa. Therefore, antibodies detecting the immunoreactive protein at 23.4 kDa could be misleading when testing for the up-regulation of frataxin in animal models.
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Affiliation(s)
- Liwei Weng
- Penn/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qingqing Wang
- Penn/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sixiang Yu
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xiaolu Yang
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David R Lynch
- Penn/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Clementina Mesaros
- Penn/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ian A Blair
- Penn/CHOP Center of Excellence in Friedreich's Ataxia, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn SRP Center and Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Gottesfeld JM. Molecular Mechanisms and Therapeutics for the GAA·TTC Expansion Disease Friedreich Ataxia. Neurotherapeutics 2019; 16:1032-1049. [PMID: 31317428 PMCID: PMC6985418 DOI: 10.1007/s13311-019-00764-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Friedreich ataxia (FRDA), the most common inherited ataxia, is caused by transcriptional silencing of the nuclear FXN gene, encoding the essential mitochondrial protein frataxin. Currently, there is no approved therapy for this fatal disorder. Gene silencing in FRDA is due to hyperexpansion of the triplet repeat sequence GAA·TTC in the first intron of the FXN gene, which results in chromatin histone modifications consistent with heterochromatin formation. Frataxin is involved in mitochondrial iron homeostasis and the assembly and transfer of iron-sulfur clusters to various mitochondrial enzymes and components of the electron transport chain. Frataxin insufficiency leads to progressive spinocerebellar neurodegeneration, causing symptoms of gait and limb ataxia, slurred speech, muscle weakness, sensory loss, and cardiomyopathy in many patients, resulting in death in early adulthood. Numerous approaches are being taken to find a treatment for FRDA, including excision or correction of the repeats by genome engineering methods, gene activation with small molecules or artificial transcription factors, delivery of frataxin to affected cells by protein replacement therapy, gene therapy, or small molecules to increase frataxin protein levels, and therapies aimed at countering the cellular consequences of reduced frataxin. This review will summarize the mechanisms involved in repeat-mediated gene silencing and recent efforts aimed at development of therapeutics.
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Affiliation(s)
- Joel M Gottesfeld
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, 92037, USA.
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Delatycki MB, Bidichandani SI. Friedreich ataxia- pathogenesis and implications for therapies. Neurobiol Dis 2019; 132:104606. [PMID: 31494282 DOI: 10.1016/j.nbd.2019.104606] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/08/2019] [Accepted: 09/04/2019] [Indexed: 01/01/2023] Open
Abstract
Friedreich ataxia is the most common of the hereditary ataxias. It is due to homozygous/compound heterozygous mutations in FXN. This gene encodes frataxin, a protein largely localized to mitochondria. In about 96% of affected individuals there is homozygosity for a GAA repeat expansion in intron 1 of the FXN gene. Studies of people with Friedreich ataxia and of animal and cell models, have provided much insight into the pathogenesis of this disorder. The expanded GAA repeat leads to transcriptional deficiency of the FXN gene. The consequent deficiency of frataxin protein leads to reduced iron-sulfur cluster biogenesis and mitochondrial ATP production, elevated mitochondrial iron, and oxidative stress. More recently, a role for inflammation has emerged as being important in the pathogenesis of Friedreich ataxia. These findings have led to a number of potential therapies that have been subjected to clinical trials or are being developed toward human studies. Therapies that have been proposed include pharmaceuticals that increase frataxin levels, protein and gene replacement therapies, antioxidants, iron chelators and modulators of inflammation. Whilst no therapies have yet been approved for Friedreich ataxia, there is much optimism that the advances in the understanding of the pathogenesis of this disorder since the discovery its genetic basis, will result in approved disease modifying therapies in the near future.
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Affiliation(s)
- Martin B Delatycki
- Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia.
| | - Sanjay I Bidichandani
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Shen X, Beasley S, Putman JN, Li Y, Prakash TP, Rigo F, Napierala M, Corey DR. Efficient electroporation of neuronal cells using synthetic oligonucleotides: identifying duplex RNA and antisense oligonucleotide activators of human frataxin expression. RNA (NEW YORK, N.Y.) 2019; 25:1118-1129. [PMID: 31151992 PMCID: PMC6800520 DOI: 10.1261/rna.071290.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/23/2019] [Indexed: 05/08/2023]
Abstract
Oligonucleotide drugs are experiencing greater success in the clinic, encouraging the initiation of new projects. Resources are insufficient to develop every potentially important project, and persuasive experimental data using cell lines close to disease target tissue is needed to prioritize candidates. Friedreich's ataxia (FRDA) is a devastating and currently incurable disease caused by insufficient expression of the enzyme frataxin (FXN). We have previously shown that synthetic nucleic acids can activate FXN expression in human patient-derived fibroblast cells. We chose to further test these compounds in induced pluripotent stem cell-derived neuronal progenitor cells (iPSC-NPCs). Here we describe methods to deliver oligonucleotides and duplex RNAs into iPSC-NPCs using electroporation. Activation of FXN expression is potent, easily reproducible, and potencies parallel those determined using patient-derived fibroblast cells. A duplex RNA and several antisense oligonucleotides (ASOs) with different combinations of 2'-methoxyethyl (2'-MOE), 2'-fluoro (2'-F), and constrained ethyl (cEt) were active, providing multiple starting points for further development and highlighting improved potency as an important goal for preclinical development. Our data support the conclusion that ASO-mediated activation of FXN is a feasible approach for treating FRDA and that electroporation is a robust method for introducing ASOs to modulate gene expressions in neuronal cells.
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Affiliation(s)
- Xiulong Shen
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
| | | | - Jennifer N Putman
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama, Birmingham, Alabama 35294, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, California 92010, USA
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama, Birmingham, Alabama 35294, USA
| | - David R Corey
- Departments of Pharmacology and Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
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Raaijmakers RHL, Ripken L, Ausems CRM, Wansink DG. CRISPR/Cas Applications in Myotonic Dystrophy: Expanding Opportunities. Int J Mol Sci 2019; 20:ijms20153689. [PMID: 31357652 PMCID: PMC6696057 DOI: 10.3390/ijms20153689] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 02/06/2023] Open
Abstract
CRISPR/Cas technology holds promise for the development of therapies to treat inherited diseases. Myotonic dystrophy type 1 (DM1) is a severe neuromuscular disorder with a variable multisystemic character for which no cure is yet available. Here, we review CRISPR/Cas-mediated approaches that target the unstable (CTG•CAG)n repeat in the DMPK/DM1-AS gene pair, the autosomal dominant mutation that causes DM1. Expansion of the repeat results in a complex constellation of toxicity at the DNA level, an altered transcriptome and a disturbed proteome. To restore cellular homeostasis and ameliorate DM1 disease symptoms, CRISPR/Cas approaches were directed at the causative mutation in the DNA and the RNA. Specifically, the triplet repeat has been excised from the genome by several laboratories via dual CRISPR/Cas9 cleavage, while one group prevented transcription of the (CTG)n repeat through homology-directed insertion of a polyadenylation signal in DMPK. Independently, catalytically deficient Cas9 (dCas9) was recruited to the (CTG)n repeat to block progression of RNA polymerase II and a dCas9-RNase fusion was shown to degrade expanded (CUG)n RNA. We compare these promising developments in DM1 with those in other microsatellite instability diseases. Finally, we look at hurdles that must be taken to make CRISPR/Cas-mediated editing a therapeutic reality in patients.
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Affiliation(s)
- Renée H L Raaijmakers
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain Cognition and Behavior, 6525 GA Nijmegen, The Netherlands
| | - Lise Ripken
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
| | - C Rosanne M Ausems
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain Cognition and Behavior, 6525 GA Nijmegen, The Netherlands
| | - Derick G Wansink
- Department of Cell Biology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands.
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Abstract
Nucleotide repeat disorders encompass more than 30 diseases, most of which show dominant inheritance, such as Huntington's disease, spinocerebellar ataxias, and myotonic dystrophies. Yet others, including Friedreich's ataxia, are recessively inherited. A common feature is the presence of a DNA tandem repeat in the disease-associated gene and the propensity of the repeats to expand in germ and in somatic cells, with ensuing neurological and frequently also neuromuscular defects. Repeat expansion is the most frequent event in these diseases; however, sequence contractions, deletions, and mutations have also been reported. Nucleotide repeat sequences are predisposed to adopt non-B-DNA conformations, such as hairpins, cruciform, and intramolecular triple-helix structures (triplexes), also known as H-DNA. For gain-of-function disorders, oligonucleotides can be used to target either transcripts or duplex DNA and in diseases with recessive inheritance oligonucleotides may be used to alter repressive DNA or RNA conformations. Most current treatment strategies are aimed at altering transcript levels, but therapies directed against DNA are also emerging, and novel strategies targeting DNA, instead of RNA, are described. Different mechanisms using modified oligonucleotides are discussed along with the structural aspects of repeat sequences, which can influence binding modes and efficiencies.
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Affiliation(s)
- Rula Zain
- Department of Laboratory Medicine, Centre for Advanced Therapies, Karolinska Institutet, Karolinska University Hospital, SE-141 86, Stockholm, Sweden.
- Department of Clinical Genetics, Centre for Rare Diseases, Karolinska University Hospital, SE-171 76, Stockholm, Sweden.
| | - C I Edvard Smith
- Department of Laboratory Medicine, Centre for Advanced Therapies, Karolinska Institutet, Karolinska University Hospital, SE-141 86, Stockholm, Sweden
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Babačić H, Mehta A, Merkel O, Schoser B. CRISPR-cas gene-editing as plausible treatment of neuromuscular and nucleotide-repeat-expansion diseases: A systematic review. PLoS One 2019; 14:e0212198. [PMID: 30794581 PMCID: PMC6386526 DOI: 10.1371/journal.pone.0212198] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 01/29/2019] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION The system of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (cas) is a new technology that allows easier manipulation of the genome. Its potential to edit genes opened a new door in treatment development for incurable neurological monogenic diseases (NMGDs). The aim of this systematic review was to summarise the findings on the current development of CRISPR-cas for therapeutic purposes in the most frequent NMGDs and provide critical assessment. METHODS AND DATA ACQUISITION We searched the MEDLINE and EMBASE databases, looking for original studies on the use of CRISPR-cas to edit pathogenic variants in models of the most frequent NMGDs, until end of 2017. We included all the studies that met the following criteria: 1. Peer-reviewed study report with explicitly described experimental designs; 2. In vitro, ex vivo, or in vivo study using human or other animal biological systems (including cells, tissues, organs, organisms); 3. focusing on CRISPR as the gene-editing method of choice; and 5. featured at least one NMGD. RESULTS We obtained 404 papers from MEDLINE and 513 from EMBASE. After removing the duplicates, we screened 490 papers by title and abstract and assessed them for eligibility. After reading 50 full-text papers, we finally selected 42 for the review. DISCUSSION Here we give a systematic summary on the preclinical development of CRISPR-cas for therapeutic purposes in NMGDs. Furthermore, we address the clinical interpretability of the findings, giving a comprehensive overview of the current state of the art. Duchenne's muscular dystrophy (DMD) paves the way forward, with 26 out of 42 studies reporting different strategies on DMD gene editing in different models of the disease. Most of the strategies aimed for permanent exon skipping by deletion with CRISPR-cas. Successful silencing of the mHTT gene with CRISPR-cas led to successful reversal of the neurotoxic effects in the striatum of mouse models of Huntington's disease. Many other strategies have been explored, including epigenetic regulation of gene expression, in cellular and animal models of: myotonic dystrophy, Fraxile X syndrome, ataxias, and other less frequent dystrophies. Still, before even considering the clinical application of CRISPR-cas, three major bottlenecks need to be addressed: efficacy, safety, and delivery of the systems. This requires a collaborative approach in the research community, while having ethical considerations in mind.
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Affiliation(s)
- Haris Babačić
- Friedrich Baur Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
- * E-mail: (BS); (HB)
| | - Aditi Mehta
- Faculty of Pharmacy, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Olivia Merkel
- Faculty of Pharmacy, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Benedikt Schoser
- Friedrich Baur Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
- * E-mail: (BS); (HB)
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32
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Yrigollen CM, Davidson BL. CRISPR to the Rescue: Advances in Gene Editing for the FMR1 Gene. Brain Sci 2019; 9:E17. [PMID: 30669625 PMCID: PMC6357057 DOI: 10.3390/brainsci9010017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/13/2019] [Accepted: 01/15/2019] [Indexed: 12/17/2022] Open
Abstract
Gene-editing using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is promising as a potential therapeutic strategy for many genetic disorders. CRISPR-based therapies are already being assessed in clinical trials, and evaluation of this technology in Fragile X syndrome has been performed by a number of groups. The findings from these studies and the advancement of CRISPR-based technologies are insightful as the field continues towards treatments and cures of Fragile X-Associated Disorders (FXADs). In this review, we summarize reports using CRISPR-editing strategies to target Fragile X syndrome (FXS) molecular dysregulation, and highlight how differences in FXS and Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) might alter treatment strategies for each syndrome. We discuss the various modifications and evolutions of the CRISPR toolkit that expand its therapeutic potential, and other considerations for moving these strategies from bench to bedside. The rapidly growing field of CRISPR therapeutics is providing a myriad of approaches to target a gene, pathway, or transcript for modification. As cures for FXADs have remained elusive, CRISPR opens new avenues to pursue.
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Affiliation(s)
- Carolyn M Yrigollen
- The Raymond G. Perelman Center of Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| | - Beverly L Davidson
- The Raymond G. Perelman Center of Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Shen X, Kilikevicius A, O'Reilly D, Prakash TP, Damha MJ, Rigo F, Corey DR. Activating frataxin expression by single-stranded siRNAs targeting the GAA repeat expansion. Bioorg Med Chem Lett 2018; 28:2850-2855. [PMID: 30076049 PMCID: PMC6129981 DOI: 10.1016/j.bmcl.2018.07.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 11/18/2022]
Abstract
Friedreich's ataxia (FRDA) is an incurable neurodegenerative disorder caused by reduced expression of the mitochondrial protein frataxin (FXN). The genetic cause of the disease is an expanded GAA repeat within the FXN gene. Agents that increase expression of FXN protein are a potential approach to therapy. We previously described anti-trinucleotide GAA duplex RNAs (dsRNAs) and antisense oligonucleotides (ASOs) that activate FXN protein expression in multiple patient derived cell lines. Here we test two distinct series of compounds for their ability to increase FXN expression. ASOs with butane linkers showed low potency, which is consistent with the low Tm values and suggesting that flexible conformation impairs activity. By contrast, single-stranded siRNAs (ss-siRNAs) that combine the strengths of dsRNA and ASO approaches had nanomolar potencies. ss-siRNAs provide an additional option for developing nucleic acid therapeutics to treat FRDA.
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Affiliation(s)
- Xiulong Shen
- Department of Pharmacology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States; Department of Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States
| | - Audrius Kilikevicius
- Department of Pharmacology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States; Department of Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States
| | - Daniel O'Reilly
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | | | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, United States
| | - David R Corey
- Department of Pharmacology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States; Department of Biochemistry, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, United States.
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Trinucleotide repeat instability during double-strand break repair: from mechanisms to gene therapy. Curr Genet 2018; 65:17-28. [DOI: 10.1007/s00294-018-0865-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/25/2018] [Accepted: 07/01/2018] [Indexed: 12/26/2022]
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Burnight ER, Giacalone JC, Cooke JA, Thompson JR, Bohrer LR, Chirco KR, Drack AV, Fingert JH, Worthington KS, Wiley LA, Mullins RF, Stone EM, Tucker BA. CRISPR-Cas9 genome engineering: Treating inherited retinal degeneration. Prog Retin Eye Res 2018; 65:28-49. [PMID: 29578069 PMCID: PMC8210531 DOI: 10.1016/j.preteyeres.2018.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 12/18/2022]
Abstract
Gene correction is a valuable strategy for treating inherited retinal degenerative diseases, a major cause of irreversible blindness worldwide. Single gene defects cause the majority of these retinal dystrophies. Gene augmentation holds great promise if delivered early in the course of the disease, however, many patients carry mutations in genes too large to be packaged into adeno-associated viral vectors and some, when overexpressed via heterologous promoters, induce retinal toxicity. In addition to the aforementioned challenges, some patients have sustained significant photoreceptor cell loss at the time of diagnosis, rendering gene replacement therapy insufficient to treat the disease. These patients will require cell replacement to restore useful vision. Fortunately, the advent of induced pluripotent stem cell and CRISPR-Cas9 gene editing technologies affords researchers and clinicians a powerful means by which to develop strategies to treat patients with inherited retinal dystrophies. In this review we will discuss the current developments in CRISPR-Cas9 gene editing in vivo in animal models and in vitro in patient-derived cells to study and treat inherited retinal degenerative diseases.
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Affiliation(s)
- Erin R Burnight
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Joseph C Giacalone
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Jessica A Cooke
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Jessica R Thompson
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Laura R Bohrer
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Kathleen R Chirco
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Arlene V Drack
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - John H Fingert
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Kristan S Worthington
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States; Department of Biochemical Engineering, University of Iowa, Iowa City, IA, United States
| | - Luke A Wiley
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Robert F Mullins
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Edwin M Stone
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
| | - Budd A Tucker
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States.
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Vannocci T, Notario Manzano R, Beccalli O, Bettegazzi B, Grohovaz F, Cinque G, de Riso A, Quaroni L, Codazzi F, Pastore A. Adding a temporal dimension to the study of Friedreich's ataxia: the effect of frataxin overexpression in a human cell model. Dis Model Mech 2018; 11:dmm032706. [PMID: 29794127 PMCID: PMC6031361 DOI: 10.1242/dmm.032706] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 05/08/2018] [Indexed: 12/27/2022] Open
Abstract
The neurodegenerative disease Friedreich's ataxia is caused by lower than normal levels of frataxin, an important protein involved in iron-sulfur (Fe-S) cluster biogenesis. An important step in designing strategies to treat this disease is to understand whether increasing the frataxin levels by gene therapy would simply be beneficial or detrimental, because previous studies, mostly based on animal models, have reported conflicting results. Here, we have exploited an inducible model, which we developed using the CRISPR/Cas9 methodology, to study the effects of frataxin overexpression in human cells and monitor how the system recovers after overexpression. Using new tools, which range from high-throughput microscopy to in cell infrared, we prove that overexpression of the frataxin gene affects the cellular metabolism. It also leads to a significant increase of oxidative stress and labile iron pool levels. These cellular alterations are similar to those observed when the gene is partly silenced, as occurs in Friedreich's ataxia patients. Our data suggest that the levels of frataxin must be tightly regulated and fine-tuned, with any imbalance leading to oxidative stress and toxicity.
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Affiliation(s)
- Tommaso Vannocci
- Basic and Clinical Neuroscience, Maurice Wohl Institute, King's College London, 5 Cutcombe Road, London SE5 9RT, UK
| | - Roberto Notario Manzano
- Basic and Clinical Neuroscience, Maurice Wohl Institute, King's College London, 5 Cutcombe Road, London SE5 9RT, UK
| | - Ombretta Beccalli
- Division of Neuroscience, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Barbara Bettegazzi
- Division of Neuroscience, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Fabio Grohovaz
- Division of Neuroscience, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Gianfelice Cinque
- Department of Physical Chemistry and Electrochemistry, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | | | - Luca Quaroni
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, PL-30387, Kraków, Poland
| | - Franca Codazzi
- Division of Neuroscience, Vita-Salute San Raffaele University and IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Annalisa Pastore
- Basic and Clinical Neuroscience, Maurice Wohl Institute, King's College London, 5 Cutcombe Road, London SE5 9RT, UK
- Molecular Medicine Department, University of Pavia, I-27100 Pavia, Italy
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Dangi AK, Sinha R, Dwivedi S, Gupta SK, Shukla P. Cell Line Techniques and Gene Editing Tools for Antibody Production: A Review. Front Pharmacol 2018; 9:630. [PMID: 29946262 PMCID: PMC6006397 DOI: 10.3389/fphar.2018.00630] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/25/2018] [Indexed: 12/16/2022] Open
Abstract
The present day modern formulation practices for drugs are based on newer tools and techniques toward effective utilization. The methods of antibody formulations are to be revolutionized based on techniques of cell engineering and gene editing. In the present review, we have discussed innovations in cell engineering toward production of novel antibodies for therapeutic applications. Moreover, this review deciphers the use of RNAi, ribozyme engineering, CRISPR-Cas-based techniques for better strategies for antibody production. Overall, this review describes the multidisciplinary aspects of the production of therapeutic proteins that has gained more attention due to its increasing demand.
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Affiliation(s)
- Arun K. Dangi
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
| | | | - Shailja Dwivedi
- Advanced Biotech Lab, Ipca Laboratories Limited, Mumbai, India
| | | | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak, India
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38
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Mollanoori H, Teimourian S. Therapeutic applications of CRISPR/Cas9 system in gene therapy. Biotechnol Lett 2018; 40:907-914. [PMID: 29704220 DOI: 10.1007/s10529-018-2555-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/16/2018] [Indexed: 12/11/2022]
Abstract
Gene therapy is based on the principle of the genetic manipulation of DNA or RNA for treating and preventing human diseases. The clustered regularly interspaced short palindromic repeats/CRISPR associated nuclease9 (CRISPR/Cas9) system, derived from the acquired immune system in bacteria and archaea, has provided a new tool for accurate manipulation of genomic sequence to attain a therapeutic result. The advantage of CRISPR which made it an easy and flexible tool for diverse genome editing purposes is that a single protein (Cas9) complex with 2 short RNA sequences, function as a site-specific endonuclease. Recently, application of CRISPR/Cas9 system has become popular for therapeutic aims such as gene therapy. In this article, we review the fundamental mechanisms of CRISPR-Cas9 function and summarize preclinical CRISPR-mediated gene therapy reports on a wide variety of disorders.
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Affiliation(s)
- Hasan Mollanoori
- Department of Medical Genetics, Iran University of Medical Sciences (IUMS), Crossroads of Shahid Hemmat & Shahid Chamran Highways, P.O. Box: 15875-6171, 1449614535, Tehran, Iran
| | - Shahram Teimourian
- Department of Medical Genetics, Iran University of Medical Sciences (IUMS), Crossroads of Shahid Hemmat & Shahid Chamran Highways, P.O. Box: 15875-6171, 1449614535, Tehran, Iran. .,Department of Infectious Diseases, School of Medicine, Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Hartman HA, Rossidis AC, Peranteau WH. In Utero Gene Therapy and Genome Editing. CURRENT STEM CELL REPORTS 2018. [DOI: 10.1007/s40778-018-0117-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Lupoli F, Vannocci T, Longo G, Niccolai N, Pastore A. The role of oxidative stress in Friedreich's ataxia. FEBS Lett 2018; 592:718-727. [PMID: 29197070 PMCID: PMC5887922 DOI: 10.1002/1873-3468.12928] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 12/12/2022]
Abstract
Oxidative stress and an increase in the levels of free radicals are important markers associated with several pathologies, including Alzheimer's disease, cancer and diabetes. Friedreich's ataxia (FRDA) is an excellent paradigmatic example of a disease in which oxidative stress plays an important, albeit incompletely understood, role. FRDA is a rare genetic neurodegenerative disease that involves the partial silencing of frataxin, a small mitochondrial protein that was completely overlooked before being linked to FRDA. More than 20 years later, we now know how important this protein is in terms of being an essential and vital part of the machinery that produces iron-sulfur clusters in the cell. In this review, we revisit the most important steps that have brought us to our current understanding of the function of frataxin and its role in disease. We discuss the current hypotheses on the role of oxidative stress in FRDA and review some of the existing animal and cellular models. We also evaluate new techniques that can assist in the study of the disease mechanisms, as well as in our understanding of the interplay between primary and secondary phenotypes.
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Affiliation(s)
- Federica Lupoli
- Department of Biotechnology, Chemistry and PharmacyUniversity of SienaItaly
| | - Tommaso Vannocci
- The Maurice Wohl InstituteDementia Research CentreKing's College LondonUK
| | | | - Neri Niccolai
- Department of Biotechnology, Chemistry and PharmacyUniversity of SienaItaly
| | - Annalisa Pastore
- The Maurice Wohl InstituteDementia Research CentreKing's College LondonUK
- Department of Molecular MedicineUniversity of PaviaItaly
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Affiliation(s)
| | - Sylvia Bösch
- Neurology Department, Innsbruck Medical University, Innsbruck, Austria
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Polyzos AA, McMurray CT. Close encounters: Moving along bumps, breaks, and bubbles on expanded trinucleotide tracts. DNA Repair (Amst) 2017; 56:144-155. [PMID: 28690053 PMCID: PMC5558859 DOI: 10.1016/j.dnarep.2017.06.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Expansion of simple triplet repeats (TNR) underlies more than 30 severe degenerative diseases. There is a good understanding of the major pathways generating an expansion, and the associated polymerases that operate during gap filling synthesis at these "difficult to copy" sequences. However, the mechanism by which a TNR is repaired depends on the type of lesion, the structural features imposed by the lesion, the assembled replication/repair complex, and the polymerase that encounters it. The relationships among these parameters are exceptionally complex and how they direct pathway choice is poorly understood. In this review, we consider the properties of polymerases, and how encounters with GC-rich or abnormal structures might influence polymerase choice and the success of replication and repair. Insights over the last three years have highlighted new mechanisms that provide interesting choices to consider in protecting genome stability.
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Affiliation(s)
- Aris A Polyzos
- MBIB Division, Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Cynthia T McMurray
- MBIB Division, Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States.
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Strawser C, Schadt K, Hauser L, McCormick A, Wells M, Larkindale J, Lin H, Lynch DR. Pharmacological therapeutics in Friedreich ataxia: the present state. Expert Rev Neurother 2017; 17:895-907. [PMID: 28724340 DOI: 10.1080/14737175.2017.1356721] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Friedreich ataxia (FRDA) is a progressive, inherited, neurodegenerative disease for which there is currently no cure or approved treatment. FRDA is caused by deficits in the production and expression of frataxin, a protein found in the mitochondria that is most likely responsible for regulating iron-sulfur cluster enzymes within the cell. A decrease in frataxin causes dysfunction of adenosine triphosphate synthesis, accumulation of mitochondrial iron, and other events leading to downstream cellular dysfunction. Areas covered: Therapeutic development for FRDA currently focuses on improving mitochondrial function and finding ways to increase frataxin expression. Additionally, the authors will review potential approaches aimed at iron modulation and genetic modulation. Finally, gene therapy is progressing rapidly and is being explored as a treatment for FRDA. Expert commentary: The collection of multiple therapeutic approaches provides many possible ways to treat FRDA. Although the mitochondrial approaches are not thought to be curative, as the primary frataxin deficit will remain, they may still produce improvements in quality of life and slowing of progression. Therapies aimed at frataxin restoration are more likely to truly modify the disease, with gene therapy as the best possibility to alter the course of the disease from both a cardiac and neurological perspective.
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Affiliation(s)
| | - Kimberly Schadt
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Lauren Hauser
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | | | - McKenzie Wells
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Jane Larkindale
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - Hong Lin
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
| | - David R Lynch
- a Children's Hospital of Philadelphia , Philadelphia , PA , USA
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