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Dong YN, Mercado-Ayón E, Coulman J, Flatley L, Ngaba LV, Adeshina MW, Lynch DR. The Regulation of the Disease-Causing Gene FXN. Cells 2024; 13:1040. [PMID: 38920668 PMCID: PMC11202134 DOI: 10.3390/cells13121040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/10/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024] Open
Abstract
Friedreich's ataxia (FRDA) is a progressive neurodegenerative disease caused in almost all patients by expanded guanine-adenine-adenine (GAA) trinucleotide repeats within intron 1 of the FXN gene. This results in a relative deficiency of frataxin, a small nucleus-encoded mitochondrial protein crucial for iron-sulfur cluster biogenesis. Currently, there is only one medication, omaveloxolone, available for FRDA patients, and it is limited to patients 16 years of age and older. This necessitates the development of new medications. Frataxin restoration is one of the main strategies in potential treatment options as it addresses the root cause of the disease. Comprehending the control of frataxin at the transcriptional, post-transcriptional, and post-translational stages could offer potential therapeutic approaches for addressing the illness. This review aims to provide a general overview of the regulation of frataxin and its implications for a possible therapeutic treatment of FRDA.
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Affiliation(s)
- Yi Na Dong
- Departments of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Jennifer Coulman
- Departments of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Liam Flatley
- The Wharton School, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lucie Vanessa Ngaba
- Departments of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Miniat W. Adeshina
- Departments of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - David R. Lynch
- Departments of Pediatrics and Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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Mishra P, Sivakumar A, Johnson A, Pernaci C, Warden AS, El-Hachem LR, Hansen E, Badell-Grau RA, Khare V, Ramirez G, Gillette S, Solis AB, Guo P, Coufal N, Cherqui S. Gene editing improves endoplasmic reticulum-mitochondrial contacts and unfolded protein response in Friedreich's ataxia iPSC-derived neurons. Front Pharmacol 2024; 15:1323491. [PMID: 38420191 PMCID: PMC10899513 DOI: 10.3389/fphar.2024.1323491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 01/16/2024] [Indexed: 03/02/2024] Open
Abstract
Friedreich ataxia (FRDA) is a multisystemic, autosomal recessive disorder caused by homozygous GAA expansion mutation in the first intron of frataxin (FXN) gene. FXN is a mitochondrial protein critical for iron-sulfur cluster biosynthesis and deficiency impairs mitochondrial electron transport chain functions and iron homeostasis within the organelle. Currently, there is no effective treatment for FRDA. We have previously demonstrated that single infusion of wild-type hematopoietic stem and progenitor cells (HSPCs) resulted in prevention of neurologic and cardiac complications of FRDA in YG8R mice, and rescue was mediated by FXN transfer from tissue engrafted, HSPC-derived microglia/macrophages to diseased neurons/myocytes. For a future clinical translation, we developed an autologous stem cell transplantation approach using CRISPR/Cas9 for the excision of the GAA repeats in FRDA patients' CD34+ HSPCs; this strategy leading to increased FXN expression and improved mitochondrial functions. The aim of the current study is to validate the efficiency and safety of our gene editing approach in a disease-relevant model. We generated a cohort of FRDA patient-derived iPSCs and isogenic lines that were gene edited with our CRISPR/Cas9 approach. iPSC derived FRDA neurons displayed characteristic apoptotic and mitochondrial phenotype of the disease, such as non-homogenous microtubule staining in neurites, increased caspase-3 expression, mitochondrial superoxide levels, mitochondrial fragmentation, and partial degradation of the cristae compared to healthy controls. These defects were fully prevented in the gene edited neurons. RNASeq analysis of FRDA and gene edited neurons demonstrated striking improvement in gene clusters associated with endoplasmic reticulum (ER) stress in the isogenic lines. Gene edited neurons demonstrated improved ER-calcium release, normalization of ER stress response gene, XBP-1, and significantly increased ER-mitochondrial contacts that are critical for functional homeostasis of both organelles, as compared to FRDA neurons. Ultrastructural analysis for these contact sites displayed severe ER structural damage in FRDA neurons, that was undetected in gene edited neurons. Taken together, these results represent a novel finding for disease pathogenesis showing dramatic ER structural damage in FRDA, validate the efficacy profile of our FXN gene editing approach in a disease relevant model, and support our approach as an effective strategy for therapeutic intervention for Friedreich's ataxia.
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Affiliation(s)
- Priyanka Mishra
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Anusha Sivakumar
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Avalon Johnson
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Carla Pernaci
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Anna S. Warden
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Lilas Rony El-Hachem
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Emily Hansen
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Rafael A. Badell-Grau
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Veenita Khare
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Gabriela Ramirez
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Sydney Gillette
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Angelyn B. Solis
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
| | - Peng Guo
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
| | - Nicole Coufal
- Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
- Sanford Consortium for Regenerative Medicine, La Jolla, CA, United States
| | - Stephanie Cherqui
- Department of Pediatrics, Division of Genetics, University of California, San Diego, San Diego, CA, United States
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Psaras Y, Toepfer CN. Targeted genetic therapies for inherited disorders that affect both cardiac and skeletal muscle. Exp Physiol 2024; 109:175-189. [PMID: 38095849 PMCID: PMC10988723 DOI: 10.1113/ep090436] [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: 10/03/2022] [Accepted: 10/27/2023] [Indexed: 12/21/2023]
Abstract
Skeletal myopathies and ataxias with secondary cardiac involvement are complex, progressive and debilitating conditions. As life expectancy increases across these conditions, cardiac involvement often becomes more prominent. This highlights the need for targeted therapies that address these evolving cardiac pathologies. Musculopathies by and large lack cures that directly target the genetic basis of the diseases; however, as our understanding of the genetic causes of these conditions has evolved, it has become tractable to develop targeted therapies using biologics, to design precision approaches to target the primary genetic causes of these varied diseases. Using the examples of Duchenne muscular dystrophy, Friedreich ataxia and Pompe disease, we discuss how the genetic causes of such diseases derail diverse homeostatic, energetic and signalling pathways, which span multiple cellular systems in varied tissues across the body. We outline existing therapeutics and treatments in the context of emerging novel genetic approaches. We discuss the hurdles that the field must overcome to deliver targeted therapies across the many tissue types affected in primary myopathies.
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Affiliation(s)
- Yiangos Psaras
- Division of Cardiovascular MedicineRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Christopher N. Toepfer
- Division of Cardiovascular MedicineRadcliffe Department of MedicineUniversity of OxfordOxfordUK
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Maheshwari S, Vilema-Enríquez G, Wade-Martins R. Patient-derived iPSC models of Friedreich ataxia: a new frontier for understanding disease mechanisms and therapeutic application. Transl Neurodegener 2023; 12:45. [PMID: 37726850 PMCID: PMC10510273 DOI: 10.1186/s40035-023-00376-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/28/2023] [Indexed: 09/21/2023] Open
Abstract
Friedreich ataxia (FRDA) is a rare genetic multisystem disorder caused by a pathological GAA trinucleotide repeat expansion in the FXN gene. The numerous drawbacks of historical cellular and rodent models of FRDA have caused difficulty in performing effective mechanistic and translational studies to investigate the disease. The recent discovery and subsequent development of induced pluripotent stem cell (iPSC) technology provides an exciting platform to enable enhanced disease modelling for studies of rare genetic diseases. Utilising iPSCs, researchers have created phenotypically relevant and previously inaccessible cellular models of FRDA. These models enable studies of the molecular mechanisms underlying GAA-induced pathology, as well as providing an exciting tool for the screening and testing of novel disease-modifying therapies. This review explores how the use of iPSCs to study FRDA has developed over the past decade, as well as discussing the enormous therapeutic potentials of iPSC-derived models, their current limitations and their future direction within the field of FRDA research.
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Affiliation(s)
- Saumya Maheshwari
- Department of Physiology, Anatomy and Genetics, Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Gabriela Vilema-Enríquez
- Department of Physiology, Anatomy and Genetics, Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Richard Wade-Martins
- Department of Physiology, Anatomy and Genetics, Kavli Institute for Nanoscience Discovery, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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Murugesan R, Karuppusamy KV, Marepally S, Thangavel S. Current approaches and potential challenges in the delivery of gene editing cargos into hematopoietic stem and progenitor cells. Front Genome Ed 2023; 5:1148693. [PMID: 37780116 PMCID: PMC10540692 DOI: 10.3389/fgeed.2023.1148693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 08/17/2023] [Indexed: 10/03/2023] Open
Abstract
Advancements in gene delivery and editing have expanded the applications of autologous hematopoietic stem and progenitor cells (HSPCs) for the treatment of monogenic and acquired diseases. The gene editing toolbox is growing, and the ability to achieve gene editing with mRNA or protein delivered intracellularly by vehicles, such as electroporation and nanoparticles, has highlighted the potential of gene editing in HSPCs. Ongoing phase I/II clinical trials with gene-edited HSPCs for β-hemoglobinopathies provide hope for treating monogenic diseases. The development of safe and efficient gene editing reagents and their delivery into hard-to-transfect HSPCs have been critical drivers in the rapid translation of HSPC gene editing into clinical studies. This review article summarizes the available payloads and delivery vehicles for gene editing HSPCs and their potential impact on therapeutic applications.
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Affiliation(s)
- Ramya Murugesan
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Christian Medical College Campus, Vellore, Tamil Nadu, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Karthik V. Karuppusamy
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Christian Medical College Campus, Vellore, Tamil Nadu, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Srujan Marepally
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Christian Medical College Campus, Vellore, Tamil Nadu, India
| | - Saravanabhavan Thangavel
- Centre for Stem Cell Research (CSCR), A Unit of InStem Bengaluru, Christian Medical College Campus, Vellore, Tamil Nadu, India
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Mishra P, Silva A, Sharma J, Nguyen J, Pizzo DP, Hinz D, Sahoo D, Cherqui S. Rescue of Alzheimer's disease phenotype in a mouse model by transplantation of wild-type hematopoietic stem and progenitor cells. Cell Rep 2023; 42:112956. [PMID: 37561625 PMCID: PMC10617121 DOI: 10.1016/j.celrep.2023.112956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 05/19/2023] [Accepted: 07/22/2023] [Indexed: 08/12/2023] Open
Abstract
Alzheimer's disease (AD) is the most prevalent cause of dementia; microglia have been implicated in AD pathogenesis, but their role is still matter of debate. Our study showed that single systemic wild-type (WT) hematopoietic stem and progenitor cell (HSPC) transplantation rescued the AD phenotype in 5xFAD mice and that transplantation may prevent microglia activation. Indeed, complete prevention of memory loss and neurocognitive impairment and decrease of β-amyloid plaques in the hippocampus and cortex were observed in the WT HSPC-transplanted 5xFAD mice compared with untreated 5xFAD mice and with mice transplanted with 5xFAD HSPCs. Neuroinflammation was also significantly reduced. Transcriptomic analysis revealed a significant decrease in gene expression related to "disease-associated microglia" in the cortex and "neurodegeneration-associated endothelial cells" in the hippocampus of the WT HSPC-transplanted 5xFAD mice compared with diseased controls. This work shows that HSPC transplant has the potential to prevent AD-associated complications and represents a promising therapeutic avenue for this disease.
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Affiliation(s)
- Priyanka Mishra
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Alexander Silva
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Jay Sharma
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Jacqueline Nguyen
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Donald P Pizzo
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Denise Hinz
- Flow Cytometry Core Facility, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Debashis Sahoo
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA; Department of Computer Science and Engineering, University of California, La Jolla, La Jolla, CA, USA; Moores Comprehensive Cancer Center, University of California, La Jolla, La Jolla, CA, USA
| | - Stephanie Cherqui
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
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7
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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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Hatanaka J, Hashiya K, Bando T, Sugiyama H. Substitution to hydrophobic linker and formation of host-guest complex enhanced the effect of synthetic transcription factor made of pyrrole-imidazole polyamide. Bioorg Med Chem 2023; 81:117208. [PMID: 36780807 DOI: 10.1016/j.bmc.2023.117208] [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: 12/19/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023]
Abstract
GAA repeat expansion in the first intron of the frataxin (FXN) gene represses the transcription of FXN, and that induces Friedreich's ataxia (FRDA). Pyrrole-imidazole polyamides (PIPs) are the class of oligopeptide that targets double-stranded DNA with sequence selectivity. Previously, bromodomain inhibitors such as JQ1 conjugated with PIPs were reported to selectively increase transcription. Here, we report the synthesis of a compound that increases the transcription of FXN in cells derived from an FRDA patient. The compound was effective in lower (one tenth) concentration than the compound that previously reported. High concentration of the compound is toxic, but toxicity was reduced with a host-guest complex.
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Affiliation(s)
- Junnosuke Hatanaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, Japan
| | - Kaori Hashiya
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, Japan
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, Japan.
| | - Hiroshi Sugiyama
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Yoshida-Ushinomiyacho, Sakyo, Kyoto, Japan.
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9
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Phenotype and management of neurologic intronic repeat disorders (NIRDs). Rev Neurol (Paris) 2023; 179:173-182. [PMID: 36371266 DOI: 10.1016/j.neurol.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 11/11/2022]
Abstract
During recent years an increasing number of neurologic disorders due to expanded tri-, tetra-, penta-, or hexa-nucleotide repeat motifs in introns of various genes have been described (neurologic intronic repeat disorders (NIRDs)). The repeat may be pathogenic in the heterozygous or homozygous form. Repeat lengths vary considerably and can be stable or unstable during transmission to the next generation. The most well-known NIRDs are Friedreich ataxia, spinocerebellar ataxia types-10, -31, and -36, CANVAS, C9Orf72 familial amyotrophic lateral sclerosis (fALS), and myotonic dystrophy-2 (MD2). Phenotypically, NIRDs manifest as mono-organ (e.g. spinocerebellar ataxia type 31) or multi-organ disease (e.g. Friedreich ataxia, myotonic dystrophy-2). A number of other more rare NIRDs have been recently detected. This review aims at summarising and discussing previous findings and recent advances concerning the etiology, pathophysiology, clinical presentation, and therapeutic management of the most common NIRDs.
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10
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Buffa V, Alvarez Vargas JR, Galy A, Spinozzi S, Rocca CJ. Hematopoietic stem and progenitors cells gene editing: Beyond blood disorders. Front Genome Ed 2023; 4:997142. [PMID: 36698790 PMCID: PMC9868335 DOI: 10.3389/fgeed.2022.997142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/19/2022] [Indexed: 01/10/2023] Open
Abstract
Lessons learned from decades-long practice in the transplantation of hematopoietic stem and progenitor cells (HSPCs) to treat severe inherited disorders or cancer, have set the stage for the current ex vivo gene therapies using autologous gene-modified hematopoietic stem and progenitor cells that have treated so far, hundreds of patients with monogenic disorders. With increased knowledge of hematopoietic stem and progenitor cell biology, improved modalities for patient conditioning and with the emergence of new gene editing technologies, a new era of hematopoietic stem and progenitor cell-based gene therapies is poised to emerge. Gene editing has the potential to restore physiological expression of a mutated gene, or to insert a functional gene in a precise locus with reduced off-target activity and toxicity. Advances in patient conditioning has reduced treatment toxicities and may improve the engraftment of gene-modified cells and specific progeny. Thanks to these improvements, new potential treatments of various blood- or immune disorders as well as other inherited diseases will continue to emerge. In the present review, the most recent advances in hematopoietic stem and progenitor cell gene editing will be reported, with a focus on how this approach could be a promising solution to treat non-blood-related inherited disorders and the mechanisms behind the therapeutic actions discussed.
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Affiliation(s)
- Valentina Buffa
- Genethon, Evry, France,Integrare Research Unit UMR_S951, Université Paris-Saclay, University Evry, Inserm, Genethon, Evry, France
| | - José Roberto Alvarez Vargas
- Genethon, Evry, France,Integrare Research Unit UMR_S951, Université Paris-Saclay, University Evry, Inserm, Genethon, Evry, France
| | - Anne Galy
- Genethon, Evry, France,Integrare Research Unit UMR_S951, Université Paris-Saclay, University Evry, Inserm, Genethon, Evry, France
| | - Simone Spinozzi
- Genethon, Evry, France,Integrare Research Unit UMR_S951, Université Paris-Saclay, University Evry, Inserm, Genethon, Evry, France
| | - Céline J. Rocca
- Genethon, Evry, France,Integrare Research Unit UMR_S951, Université Paris-Saclay, University Evry, Inserm, Genethon, Evry, France,*Correspondence: Céline J. Rocca,
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Profeta V, McIntyre K, Wells M, Park C, Lynch DR. Omaveloxolone: an activator of Nrf2 for the treatment of Friedreich ataxia. Expert Opin Investig Drugs 2023; 32:5-16. [PMID: 36708320 DOI: 10.1080/13543784.2023.2173063] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
INTRODUCTION Friedreich ataxia (FRDA) is a rare autosomal recessive degenerative disorder characterized by ataxia, dysarthria, diabetes, cardiomyopathy, scoliosis, and occasionally vision loss in late-stage disease. The discovery of the abnormal gene in FRDA and its product frataxin has provided insight into the pathophysiology and mechanisms of treatment. AREAS COVERED Although the neurologic phenotype of FRDA is well defined, there are currently no established pharmacological treatments. Omaveloxolone, a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, is currently under review by the Food and Drug Administration (FDA) and has the potential to be the first approved treatment for FRDA. In the present report, we have reviewed the basic and clinical literature on Nrf2 deficiency in FRDA, and evidence for the benefit of omaveloxolone. EXPERT OPINION The present perspective suggests that omaveloxolone is a rational and efficacious therapy that is possibly disease modifying in treatment of FRDA.
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Affiliation(s)
- Victoria Profeta
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kellie McIntyre
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - McKenzie Wells
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Courtney Park
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David R Lynch
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Abstract
This narrative review aims at providing an update on the management of inherited cerebellar ataxias (ICAs), describing main clinical entities, genetic analysis strategies and recent therapeutic developments. Initial approach facing a patient with cerebellar ataxia requires family medical history, physical examination, exclusions of acquired causes and genetic analysis, including Next-Generation Sequencing (NGS). To guide diagnosis, several algorithms and a new genetic nomenclature for recessive cerebellar ataxias have been proposed. The challenge of NGS analysis is the identification of causative variant, trio analysis being usually the most appropriate option. Public genomic databases as well as pathogenicity prediction software facilitate the interpretation of NGS results. We also report on key clinical points for the diagnosis of the main ICAs, including Friedreich ataxia, CANVAS, polyglutamine spinocerebellar ataxias, Fragile X-associated tremor/ataxia syndrome. Rarer forms should not be neglected because of diagnostic biomarkers availability, disease-modifying treatments, or associated susceptibility to malignancy. Diagnostic difficulties arise from allelic and phenotypic heterogeneity as well as from the possibility for one gene to be associated with both dominant and recessive inheritance. To complicate the phenotype, cerebellar cognitive affective syndrome can be associated with some subtypes of cerebellar ataxia. Lastly, we describe new therapeutic leads: antisense oligonucleotides approach in polyglutamine SCAs and viral gene therapy in Friedreich ataxia. This review provides support for diagnosis, genetic counseling and therapeutic management of ICAs in clinical practice.
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Meszaros A, Ahmed J, Russo G, Tompa P, Lazar T. The evolution and polymorphism of mono-amino acid repeats in androgen receptor and their regulatory role in health and disease. Front Med (Lausanne) 2022; 9:1019803. [PMID: 36388907 PMCID: PMC9642029 DOI: 10.3389/fmed.2022.1019803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
Androgen receptor (AR) is a key member of nuclear hormone receptors with the longest intrinsically disordered N-terminal domain (NTD) in its protein family. There are four mono-amino acid repeats (polyQ1, polyQ2, polyG, and polyP) located within its NTD, of which two are polymorphic (polyQ1 and polyG). The length of both polymorphic repeats shows clinically important correlations with disease, especially with cancer and neurodegenerative diseases, as shorter and longer alleles exhibit significant differences in expression, activity and solubility. Importantly, AR has also been shown to undergo condensation in the nucleus by liquid-liquid phase separation, a process highly sensitive to protein solubility and concentration. Nonetheless, in prostate cancer cells, AR variants also partition into transcriptional condensates, which have been shown to alter the expression of target gene products. In this review, we summarize current knowledge on the link between AR repeat polymorphisms and cancer types, including mechanistic explanations and models comprising the relationship between condensate formation, polyQ1 length and transcriptional activity. Moreover, we outline the evolutionary paths of these recently evolved amino acid repeats across mammalian species, and discuss new research directions with potential breakthroughs and controversies in the literature.
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Affiliation(s)
- Attila Meszaros
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Junaid Ahmed
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Giorgio Russo
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Peter Tompa
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Research Centre for Natural Sciences (RCNS), ELKH, Budapest, Hungary
- *Correspondence: Peter Tompa,
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), Brussels, Belgium
- Structural Biology Brussels (SBB), Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Tamas Lazar,
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14
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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: 3] [Impact Index Per Article: 1.5] [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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15
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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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16
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Antony JS, Daniel-Moreno A, Lamsfus-Calle A, Raju J, Kaftancioglu M, Ureña-Bailén G, Rottenberger J, Hou Y, Santhanakumaran V, Lee JH, Heumos L, Böhringer J, Krägeloh-Mann I, Handgretinger R, Mezger M. A Mutation-Agnostic Hematopoietic Stem Cell Gene Therapy for Metachromatic Leukodystrophy. CRISPR J 2021; 5:66-79. [PMID: 34882002 DOI: 10.1089/crispr.2021.0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Metachromatic leukodystrophy (MLD) is a rare genetic disorder caused by mutations in the Arylsulfatase-A (ARSA) gene. The enzyme plays a key role in sulfatide metabolism in brain cells, and its deficiency leads to neurodegeneration. The clinical manifestations of MLD include stagnation and decline of motor and cognitive function, leading to premature death with limited standard treatment options. Here, we describe a mutation-agnostic hematopoietic stem and progenitor cell (HSPC) gene therapy using CRISPR-Cas9 and AAV6 repair template as a prospective treatment option for MLD. Our strategy achieved efficient insertions and deletions (>87%) and a high level of gene integration (>47%) at the ARSA locus in human bone marrow-derived HSPCs, with no detectable off-target editing. As a proof of concept, we tested our mutation-agnostic therapy in HSPCs derived from two MLD patients with distinct mutations and demonstrated restoration of ARSA enzyme activity (>30-fold improvement) equivalent to healthy adults. In summary, our investigation enabled a mutation-agnostic therapy for MLD patients with proven efficacy and strong potential for clinical translation.
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Affiliation(s)
- Justin S Antony
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Alberto Daniel-Moreno
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Andrés Lamsfus-Calle
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Janani Raju
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Merve Kaftancioglu
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Guillermo Ureña-Bailén
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Jennifer Rottenberger
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Yujuan Hou
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Vidiyaah Santhanakumaran
- Department of Pediatric Neurology, University Children's Hospital Tübingen, Germany; and University of Tübingen, Tübingen, Germany
| | - Jun-Hoe Lee
- Quantitative Biology Center (QBiC), University of Tübingen, Tübingen, Germany
| | - Lukas Heumos
- Quantitative Biology Center (QBiC), University of Tübingen, Tübingen, Germany
| | - Judith Böhringer
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany.,Department of Pediatric Neurology, University Children's Hospital Tübingen, Germany; and University of Tübingen, Tübingen, Germany
| | - Ingeborg Krägeloh-Mann
- Department of Pediatric Neurology, University Children's Hospital Tübingen, Germany; and University of Tübingen, Tübingen, Germany
| | - Rupert Handgretinger
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
| | - Markus Mezger
- Department of Hematology and Oncology, University Children's Hospital, University of Tübingen, Germany; University of Tübingen, Tübingen, Germany
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17
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The power and the promise of CRISPR/Cas9 genome editing for clinical application with gene therapy. J Adv Res 2021; 40:135-152. [PMID: 36100322 PMCID: PMC9481961 DOI: 10.1016/j.jare.2021.11.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/22/2021] [Accepted: 11/30/2021] [Indexed: 02/07/2023] Open
Abstract
Due to its high accuracy and efficiency, CRISPR/Cas9 techniques may provide a great chance to treat some gene-related diseases. Researchers used the CRISPR/Cas9 technique to cure or alleviate cancers through different approaches, such as gene therapy and immune therapy. The treatment of ocular diseases by Cas9 has entered into clinical phases.
Background Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is derived from the bacterial innate immune system and engineered as a robust gene-editing tool. Due to the higher specificity and efficiency of CRISPR/Cas9, it has been widely applied to many genetic and non-genetic disease, including cancers, genetic hemolytic diseases, acquired immunodeficiency syndrome, cardiovascular diseases, ocular diseases, and neurodegenerative diseases, and some X-linked diseases. Furthermore, in terms of the therapeutic strategy of cancers, many researchers used the CRISPR/Cas9 technique to cure or alleviate cancers through different approaches, such as gene therapy and immune therapy. Aim of Review Here, we conclude the recent application and clinical trials of CRISPR/Cas9 in non-cancerous diseases and cancers and pointed out some of the problems to be solved. Key Scientific Concepts of Review CRISPR/Cas9, derived from the microbial innate immune system, is developed as a robust gene-editing tool and has been applied widely. Due to its high accuracy and efficiency, CRISPR/Cas9 techniques may provide a great chance to treat some gene-related diseases by disrupting, inserting, correcting, replacing, or blocking genes for clinical application with gene therapy.
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18
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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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19
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Koniali L, Lederer CW, Kleanthous M. Therapy Development by Genome Editing of Hematopoietic Stem Cells. Cells 2021; 10:1492. [PMID: 34198536 PMCID: PMC8231983 DOI: 10.3390/cells10061492] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/12/2022] Open
Abstract
Accessibility of hematopoietic stem cells (HSCs) for the manipulation and repopulation of the blood and immune systems has placed them at the forefront of cell and gene therapy development. Recent advances in genome-editing tools, in particular for clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) and CRISPR/Cas-derived editing systems, have transformed the gene therapy landscape. Their versatility and the ability to edit genomic sequences and facilitate gene disruption, correction or insertion, have broadened the spectrum of potential gene therapy targets and accelerated the development of potential curative therapies for many rare diseases treatable by transplantation or modification of HSCs. Ongoing developments seek to address efficiency and precision of HSC modification, tolerability of treatment and the distribution and affordability of corresponding therapies. Here, we give an overview of recent progress in the field of HSC genome editing as treatment for inherited disorders and summarize the most significant findings from corresponding preclinical and clinical studies. With emphasis on HSC-based therapies, we also discuss technical hurdles that need to be overcome en route to clinical translation of genome editing and indicate advances that may facilitate routine application beyond the most common disorders.
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Affiliation(s)
- Lola Koniali
- Department of Molecular Genetics Thalassemia, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (L.K.); (M.K.)
| | - Carsten W. Lederer
- Department of Molecular Genetics Thalassemia, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (L.K.); (M.K.)
- Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
| | - Marina Kleanthous
- Department of Molecular Genetics Thalassemia, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (L.K.); (M.K.)
- Cyprus School of Molecular Medicine, Nicosia 2371, Cyprus
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20
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Maganti HB, Bailey AJM, Kirkham AM, Shorr R, Pineault N, Allan DS. Persistence of CRISPR/Cas9 gene edited hematopoietic stem cells following transplantation: A systematic review and meta-analysis of preclinical studies. Stem Cells Transl Med 2021; 10:996-1007. [PMID: 33666363 PMCID: PMC8235122 DOI: 10.1002/sctm.20-0520] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/14/2021] [Accepted: 01/24/2021] [Indexed: 12/13/2022] Open
Abstract
Gene editing blood‐derived cells is an attractive approach to cure selected monogenic diseases but remains experimental. A systematic search of preclinical controlled studies is needed to determine the persistence of edited cells following reinfusion. All studies identified in our systematic search (to 20 October 2020) examining the use of CRISPR/Cas9 gene editing in blood‐derived cells for transplantation were included. Meta‐analysis was performed to determine the engraftment and persistence of gene edited cells. A total of 3538 preclinical studies were identified with 15 published articles meeting eligibility for meta‐analysis. These in vivo animal studies examined editing of hemoglobin to correct sickle cell disease (eight studies), inducing resistance to acquired immunodeficiency syndrome (two studies), and six other monogenic disorders (single studies). CRISPR‐Cas9 edited hematopoietic stem and progenitor cells demonstrated equivalent early engraftment compared to controls in meta‐analysis but persistence of gene‐edited cells was reduced at later time points and in secondary transplant recipients. Subgroup analysis in studies targeting the hemoglobin gene revealed a significant reduction in the persistence of gene‐edited cells whether homology‐directed repair or nonhomologous end‐joining were used. No adverse side effects were reported. Significant heterogeneity in study design and outcome reporting was observed and the potential for bias was identified in all studies. CRISPR‐Cas9 gene edited cells engraft similarly to unedited hematopoietic cells. Persistence of gene edited cells, however, remains a challenge and improved methods of targeting hematopoietic stem cells are needed. Reducing heterogeneity and potential risk of bias will hasten the development of informative clinical trials.
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Affiliation(s)
- Harinad B Maganti
- Canadian Blood Services, Stem Cells and Centre for Innovation, Ottawa, Ontario, Canada.,Clinical Epidemiology & Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Adrian J M Bailey
- Canadian Blood Services, Stem Cells and Centre for Innovation, Ottawa, Ontario, Canada.,Clinical Epidemiology & Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Aidan M Kirkham
- Canadian Blood Services, Stem Cells and Centre for Innovation, Ottawa, Ontario, Canada
| | - Risa Shorr
- Information Services, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Nicolas Pineault
- Canadian Blood Services, Stem Cells and Centre for Innovation, Ottawa, Ontario, Canada
| | - David S Allan
- Canadian Blood Services, Stem Cells and Centre for Innovation, Ottawa, Ontario, Canada.,Clinical Epidemiology & Regenerative Medicine, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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