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Walker AJ, Graham C, Greenwood M, Woodall M, Maeshima R, O’Hara-Wright M, Sanz DJ, Guerrini I, Aldossary AM, O’Callaghan C, Baines DL, Harrison PT, Hart SL. Molecular and functional correction of a deep intronic splicing mutation in CFTR by CRISPR-Cas9 gene editing. Mol Ther Methods Clin Dev 2023; 31:101140. [PMID: 38027060 PMCID: PMC10661860 DOI: 10.1016/j.omtm.2023.101140] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/17/2023] [Indexed: 12/01/2023]
Abstract
Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. The 10th most common mutation, c.3178-2477C>T (3849+10kb C>T), involves a cryptic, intronic splice site. This mutation was corrected in CF primary cells homozygous for this mutation by delivering pairs of guide RNAs (gRNAs) with Cas9 protein in ribonucleoprotein (RNP) complexes that introduce double-strand breaks to flanking sites to excise the 3849+10kb C>T mutation, followed by DNA repair by the non-homologous end-joining pathway, which functions in all cells of the airway epithelium. RNP complexes were delivered to CF basal epithelial cell by a non-viral, receptor-targeted nanocomplex comprising a formulation of targeting peptides and lipids. Canonical CFTR mRNA splicing was, thus, restored leading to the restoration of CFTR protein expression with concomitant restoration of electrophysiological function in airway epithelial air-liquid interface cultures. Off-target editing was not detected by Sanger sequencing of in silico-selected genomic sites with the highest sequence similarities to the gRNAs, although more sensitive unbiased whole genome sequencing methods would be required for possible translational developments. This approach could potentially be used to correct aberrant splicing signals in several other CF mutations and other genetic disorders where deep-intronic mutations are pathogenic.
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Affiliation(s)
- Amy J. Walker
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Carina Graham
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Miriam Greenwood
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Maximillian Woodall
- Institute for Infection and Immunity, St. George’s, University of London, London, UK
| | - Ruhina Maeshima
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Michelle O’Hara-Wright
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - David J. Sanz
- Department of Physiology, BioSciences Institute, University College Cork, Cork, Ireland
| | - Ileana Guerrini
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Ahmad M. Aldossary
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Christopher O’Callaghan
- Infection, Immunity & Inflammation Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Deborah L. Baines
- Institute for Infection and Immunity, St. George’s, University of London, London, UK
| | - Patrick T. Harrison
- Department of Physiology, BioSciences Institute, University College Cork, Cork, Ireland
| | - Stephen L. Hart
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
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Oliver KE, Carlon MS, Pedemonte N, Lopes-Pacheco M. The revolution of personalized pharmacotherapies for cystic fibrosis: what does the future hold? Expert Opin Pharmacother 2023; 24:1545-1565. [PMID: 37379072 PMCID: PMC10528905 DOI: 10.1080/14656566.2023.2230129] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 06/29/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF), a potentially fatal genetic disease, is caused by loss-of-function mutations in the gene encoding for the CFTR chloride/bicarbonate channel. Modulator drugs rescuing mutant CFTR traffic and function are now in the clinic, providing unprecedented breakthrough therapies for people with CF (PwCF) carrying specific genotypes. However, several CFTR variants are unresponsive to these therapies. AREA COVERED We discussed several therapeutic approaches that are under development to tackle the fundamental cause of CF, including strategies targeting defective CFTR mRNA and/or protein expression and function. Alternatively, defective chloride secretion and dehydration in CF epithelia could be restored by exploiting pharmacological modulation of alternative targets, i.e., ion channels/transporters that concur with CFTR to maintain the airway surface liquid homeostasis (e.g., ENaC, TMEM16A, SLC26A4, SLC26A9, and ATP12A). Finally, we assessed progress and challenges in the development of gene-based therapies to replace or correct the mutant CFTR gene. EXPERT OPINION CFTR modulators are benefiting many PwCF responsive to these drugs, yielding substantial improvements in various clinical outcomes. Meanwhile, the CF therapy development pipeline continues to expand with the development of novel CFTR modulators and alternative therapeutic strategies with the ultimate goal of providing effective therapies for all PwCF in the foreseeable future.
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Affiliation(s)
- Kathryn E. Oliver
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
- Center for Cystic Fibrosis and Airways Disease Research, Emory University and Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Marianne S. Carlon
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium
- Center for Molecular Medicine, KU Leuven, Leuven, Belgium
| | | | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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Kerschner JL, Paranjapye A, Vaghela N, Wilson MD, Harris A. An ectopic enhancer restores CFTR expression through de novo chromatin looping. Gene Ther 2023; 30:478-486. [PMID: 36510002 DOI: 10.1038/s41434-022-00378-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/30/2022] [Accepted: 11/29/2022] [Indexed: 12/14/2022]
Abstract
Transcription of the cystic fibrosis transmembrane conductance regulator (CFTR) gene is regulated by both ubiquitous and cell-type selective cis-regulatory elements (CREs). These CREs include extragenic and intronic enhancers that bind lineage-specific transcription factors, and architectural protein-marked structural elements. Deletion of the airway-selective -35 kb enhancer in 16HBE14o- lung epithelial cells was shown earlier to disrupt normal enhancer-promoter looping at the CFTR locus and nearly abolish its expression. Using a 16HBE14o- clone that lacks the endogenous -35 kb CRE, we explore the impact of relocating the functional core of this element to an ectopic site in intron 1. The -35 kb sequence establishes a de novo enhancer signature in chromatin at the insertion site, and augments CFTR expression, albeit not fully restoring WT levels. The relocated -35 kb enhancer also initiates de novo chromatin contacts with the CFTR promoter and other known CFTR CREs. These results are broadly relevant to therapeutic gene editing.
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Affiliation(s)
- Jenny L Kerschner
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, 44116, USA
| | - Alekh Paranjapye
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, 44116, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA
| | - Nirbhayaditya Vaghela
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, 44116, USA
| | - Michael D Wilson
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, 44116, USA
| | - Ann Harris
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, 44116, USA.
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4
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Genome-engineering technologies for modeling and treatment of cystic fibrosis. Adv Med Sci 2023; 68:111-120. [PMID: 36917892 DOI: 10.1016/j.advms.2023.02.003] [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: 08/20/2022] [Revised: 10/29/2022] [Accepted: 02/26/2023] [Indexed: 03/14/2023]
Abstract
Cystic fibrosis (CF) is an autosomal recessive disease caused by defects in the CF transmembrane conductance regulator (CFTR) protein. Due to the genetic nature of the disease, interventions in the genome can target any underlying alterations and potentially provide permanent disease resolution. The current development of gene-editing tools, such as designer nuclease technology capable of genome correction, holds great promise for both CF and other genetic diseases. In recent years, Cas9-based technologies have enabled the generation of genetically defined human stem cell and disease models based on induced pluripotent stem cells (iPSC). In this article, we outline the potential and possibilities of using CRISPR/Cas9-based gene-editing technology in CF modeling.
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Development of novel therapeutics for all individuals with CF (the future goes on). J Cyst Fibros 2023; 22 Suppl 1:S45-S49. [PMID: 36319570 DOI: 10.1016/j.jcf.2022.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/06/2022] [Accepted: 10/17/2022] [Indexed: 11/08/2022]
Abstract
Despite the major advances and successes in finding and establishing new treatments that tackle the basic defect in Cystic Fibrosis (CF), there is still an unmet need to bring these potentially curative therapies to all individuals with CF. Here, we review aspects of what is still missing to treat all individuals with CF by such approaches. On the one hand, we discuss novel holistic (high-throughput) approaches to elucidate mechanistic defects caused by distinct classes of mutations to identify novel drug targets. On the other hand, we examine therapeutic approaches to correct the gene in its own environment, i.e., in the genome.
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Egan ME. Non-Modulator Therapies: Developing a Therapy for Every Cystic Fibrosis Patient. Clin Chest Med 2022; 43:717-725. [PMID: 36344076 DOI: 10.1016/j.ccm.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy brings hope to most patients with cystic fibrosis (CF), but not all. For approximately 12% of CF patients with premature termination codon mutations, large deletions, insertions, and frameshifts, the CFTR modulator therapy is not effective. Many believe that genetic-based therapies such as RNA therapies, DNA therapies, and gene editing technologies will be needed to treat mutations that are not responsive to modulator therapy. Delivery of these therapeutic agents to affected cells is the major challenge that will need to be overcome if we are to harness the power of these emerging therapies for the treatment of CF.
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Affiliation(s)
- Marie E Egan
- Division of Pulmonary Allergy Immunology Sleep Medicine, Department of Pediatrics, Pediatric Pulmonary Allergy Immunology and Sleep Medicine, Yale Cystic Fibrosis Center, School of Medicine, Yale University, 333 Cedar Street, PO Box 208064, New Haven, CT 06520, USA.
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Sui H, Xu X, Su Y, Gong Z, Yao M, Liu X, Zhang T, Jiang Z, Bai T, Wang J, Zhang J, Xu C, Luo M. Gene therapy for cystic fibrosis: Challenges and prospects. Front Pharmacol 2022; 13:1015926. [PMID: 36304167 PMCID: PMC9592762 DOI: 10.3389/fphar.2022.1015926] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/29/2022] [Indexed: 11/25/2022] Open
Abstract
Cystic fibrosis (CF) is a life-threatening autosomal-recessive disease caused by mutations in a single gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). CF effects multiple organs, and lung disease is the primary cause of mortality. The median age at death from CF is in the early forties. CF was one of the first diseases to be considered for gene therapy, and efforts focused on treating CF lung disease began shortly after the CFTR gene was identified in 1989. However, despite the quickly established proof-of-concept for CFTR gene transfer in vitro and in clinical trials in 1990s, to date, 36 CF gene therapy clinical trials involving ∼600 patients with CF have yet to achieve their desired outcomes. The long journey to pursue gene therapy as a cure for CF encountered more difficulties than originally anticipated, but immense progress has been made in the past decade in the developments of next generation airway transduction viral vectors and CF animal models that reproduced human CF disease phenotypes. In this review, we look back at the history for the lessons learned from previous clinical trials and summarize the recent advances in the research for CF gene therapy, including the emerging CRISPR-based gene editing strategies. We also discuss the airway transduction vectors, large animal CF models, the complexity of CF pathogenesis and heterogeneity of CFTR expression in airway epithelium, which are the major challenges to the implementation of a successful CF gene therapy, and highlight the future opportunities and prospects.
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Affiliation(s)
- Hongshu Sui
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
- *Correspondence: Hongshu Sui, ; Changlong Xu, ; Mingjiu Luo,
| | - Xinghua Xu
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Yanping Su
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Zhaoqing Gong
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Minhua Yao
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Xiaocui Liu
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Ting Zhang
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Ziyao Jiang
- Department of Histology and Embryology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Science, Jinan, Shandong, China
| | - Tianhao Bai
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai’an, China
| | - Junzuo Wang
- The Affiliated Tai’an City Central Hospital of Qingdao University, Tai’an, Shandong, China
| | - Jingjun Zhang
- Department of Neurology, The Second Affiliated Hospital of Shandong First Medical University, Tai’an, Shandong, China
| | - Changlong Xu
- The Reproductive Medical Center of Nanning Second People’s Hospital, Nanning, China
- National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Talent Highland of Bio-targeting Theranostics, Guangxi Medical University, Nanning, China
- *Correspondence: Hongshu Sui, ; Changlong Xu, ; Mingjiu Luo,
| | - Mingjiu Luo
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai’an, China
- *Correspondence: Hongshu Sui, ; Changlong Xu, ; Mingjiu Luo,
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8
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Advances in Preclinical In Vitro Models for the Translation of Precision Medicine for Cystic Fibrosis. J Pers Med 2022; 12:jpm12081321. [PMID: 36013270 PMCID: PMC9409685 DOI: 10.3390/jpm12081321] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
The development of preclinical in vitro models has provided significant progress to the studies of cystic fibrosis (CF), a frequently fatal monogenic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein. Numerous cell lines were generated over the last 30 years and they have been instrumental not only in enhancing the understanding of CF pathological mechanisms but also in developing therapies targeting the underlying defects in CFTR mutations with further validation in patient-derived samples. Furthermore, recent advances toward precision medicine in CF have been made possible by optimizing protocols and establishing novel assays using human bronchial, nasal and rectal tissues, and by progressing from two-dimensional monocultures to more complex three-dimensional culture platforms. These models also enable to potentially predict clinical efficacy and responsiveness to CFTR modulator therapies at an individual level. In parallel, advanced systems, such as induced pluripotent stem cells and organ-on-a-chip, continue to be developed in order to more closely recapitulate human physiology for disease modeling and drug testing. In this review, we have highlighted novel and optimized cell models that are being used in CF research to develop novel CFTR-directed therapies (or alternative therapeutic interventions) and to expand the usage of existing modulator drugs to common and rare CF-causing mutations.
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9
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Ensinck MM, Carlon MS. One Size Does Not Fit All: The Past, Present and Future of Cystic Fibrosis Causal Therapies. Cells 2022; 11:cells11121868. [PMID: 35740997 PMCID: PMC9220995 DOI: 10.3390/cells11121868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/25/2022] [Accepted: 05/28/2022] [Indexed: 02/04/2023] Open
Abstract
Cystic fibrosis (CF) is the most common monogenic disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Over the last 30 years, tremendous progress has been made in understanding the molecular basis of CF and the development of treatments that target the underlying defects in CF. Currently, a highly effective CFTR modulator treatment (Kalydeco™/Trikafta™) is available for 90% of people with CF. In this review, we will give an extensive overview of past and ongoing efforts in the development of therapies targeting the molecular defects in CF. We will discuss strategies targeting the CFTR protein (i.e., CFTR modulators such as correctors and potentiators), its cellular environment (i.e., proteostasis modulation, stabilization at the plasma membrane), the CFTR mRNA (i.e., amplifiers, nonsense mediated mRNA decay suppressors, translational readthrough inducing drugs) or the CFTR gene (gene therapies). Finally, we will focus on how these efforts can be applied to the 15% of people with CF for whom no causal therapy is available yet.
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Affiliation(s)
- Marjolein M. Ensinck
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
| | - Marianne S. Carlon
- Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium;
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Flanders, Belgium
- Correspondence:
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Grubb BR, Livraghi-Butrico A. Animal models of cystic fibrosis in the era of highly effective modulator therapies. Curr Opin Pharmacol 2022; 64:102235. [DOI: 10.1016/j.coph.2022.102235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 12/17/2022]
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Effective viral-mediated lung gene therapy: is airway surface preparation necessary? Gene Ther 2022:10.1038/s41434-022-00332-7. [DOI: 10.1038/s41434-022-00332-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 12/20/2022]
Abstract
AbstractGene-based therapeutics are actively being pursued for the treatment of lung diseases. While promising advances have been made over the last decades, the absence of clinically available lung-directed genetic therapies highlights the difficulties associated with this effort. Largely, progress has been hindered by the presence of inherent physical and physiological airway barriers that significantly reduce the efficacy of gene transfer. These barriers include surface mucus, mucociliary action, cell-to-cell tight junctions, and the basolateral cell membrane location of viral receptors for many commonly used gene vectors. Accordingly, airway surface preparation methods have been developed to disrupt these barriers, creating a more conducive environment for gene uptake into the target airway cells. The two major approaches have been chemical and physical methods. Both have proven effective for increasing viral-mediated gene transfer pre-clinically, although with variable effect depending on the specific strategy employed. While such methods have been explored extensively in experimental settings, they have not been used clinically. This review covers the airway surface preparation strategies reported in the literature, the advantages and disadvantages of each method, as well as a discussion about applying this concept in the clinic.
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12
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Haq I, Almulhem M, Soars S, Poulton D, Brodlie M. Precision Medicine Based on CFTR Genotype for People with Cystic Fibrosis. Pharmgenomics Pers Med 2022; 15:91-104. [PMID: 35153502 PMCID: PMC8828078 DOI: 10.2147/pgpm.s245603] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
Cystic fibrosis (CF) is an autosomal recessive genetic condition that is caused by variants in the cystic fibrosis transmembrane conductance regulator gene. This causes multisystem disease due to dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel at the apical surface of epithelia. Until recently, treatment was directed at managing the downstream effects in affected organs, principally improving airway clearance and treating infection in the lungs and improving malabsorption in the gastrointestinal tract. Care delivered by multidisciplinary teams has yielded incremental improvements in outcomes. However, the development of small-molecule CFTR modulator drugs over the last decade has heralded a new era of CF therapeutics. Modulators target the underlying defect and improve CFTR function. Either monotherapy or a combination of modulators is used depending on the specific genotype and class of CFTR disease-causing variants that an individual has. Both ivacaftor and the ivacaftor/tezacaftor/elexacaftor combination have been demonstrated to be associated with clinically very significant benefits in randomised trials and have rapidly been made available as part of standard care in many countries. CFTR modulators represent one of the best examples of precision medicine to date. They are expensive, however, and equity of access to them worldwide remains an issue. Studies and approvals are also ongoing for children under the age of 6 years for ivacaftor/tezacaftor/elexacaftor. Furthermore, no modulators are available for around 10% of the people with CF. In this review, we firstly summarise the genetics, pathophysiology and clinical problems associated with CF. We then discuss the development of CFTR modulators and key clinical trials to support their use along with other potential future therapeutic approaches.
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Affiliation(s)
- Iram Haq
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Paediatric Respiratory Medicine, Great North Children’s Hospital, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Maryam Almulhem
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Simone Soars
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - David Poulton
- Paediatric Respiratory Medicine, Great North Children’s Hospital, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Paediatrics, Ninewells Hospital, NHS Tayside, Dundee, UK
| | - Malcolm Brodlie
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Paediatric Respiratory Medicine, Great North Children’s Hospital, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Correspondence: Malcolm Brodlie, Paediatric Respiratory Medicine, Level 3, Clinical Resource Building, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK, Tel +44 191 2336161, Email
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13
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Assays of CFTR Function In Vitro, Ex Vivo and In Vivo. Int J Mol Sci 2022; 23:ijms23031437. [PMID: 35163362 PMCID: PMC8836180 DOI: 10.3390/ijms23031437] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/12/2022] [Accepted: 01/21/2022] [Indexed: 12/22/2022] Open
Abstract
Cystic fibrosis, a multi-organ genetic disease, is characterized by abnormal function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel at the apical membrane of several epithelia. In recent years, therapeutic strategies have been developed to correct the CFTR defect. To evaluate CFTR function at baseline for diagnosis, or the efficacy of CFTR-restoring therapy, reliable tests are needed to measure CFTR function, in vitro, ex vivo and in vivo. In vitro techniques either directly or indirectly measure ion fluxes; direct measurement of ion fluxes and quenching of fluorescence in cell-based assays, change in transmembrane voltage or current in patch clamp or Ussing chamber, swelling of CFTR-containing organoids by secondary water influx upon CFTR activation. Several cell or tissue types can be used. Ex vivo and in vivo assays similarly evaluate current (intestinal current measurement) and membrane potential differences (nasal potential difference), on tissues from individual patients. In the sweat test, the most frequently used in vivo evaluation of CFTR function, chloride concentration or stimulated sweat rate can be directly measured. Here, we will describe the currently available bio-assays for quantitative evaluation of CFTR function, their indications, advantages and disadvantages, and correlation with clinical outcome measures.
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Huber HF, Jaberi-Douraki M, DeVader S, Aparicio-Lopez C, Nava-Chavez J, Xu X, Millagaha Gedara NI, Gaudreault NN, Delong RK. Targeting SARS-CoV-2 Variants with Nucleic Acid Therapeutic Nanoparticle Conjugates. Pharmaceuticals (Basel) 2021; 14:1012. [PMID: 34681236 PMCID: PMC8539335 DOI: 10.3390/ph14101012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 12/19/2022] Open
Abstract
The emergence of SARS-CoV-2 variants is cause for concern, because these may become resistant to current vaccines and antiviral drugs in development. Current drugs target viral proteins, resulting in a critical need for RNA-targeted nanomedicines. To address this, a comparative analysis of SARS-CoV-2 variants was performed. Several highly conserved sites were identified, of which the most noteworthy is a partial homopurine palindrome site with >99% conservation within the coding region. This sequence was compared among recently emerged, highly infectious SARS-CoV-2 variants. Conservation of the site was maintained among these emerging variants, further contributing to its potential as a regulatory target site for SARS-CoV-2. RNAfold was used to predict the structures of the highly conserved sites, with some resulting structures being common among coronaviridae. An RNA-level regulatory map of the conserved regions of SARS-CoV-2 was produced based on the predicted structures, with each representing potential target sites for antisense oligonucleotides, triplex-forming oligomers, and aptamers. Additionally, homopurine/homopyrimidine sequences within the viral genome were identified. These sequences also demonstrate appropriate target sites for antisense oligonucleotides and triplex-forming oligonucleotides. An experimental strategy to investigate these is summarized along with potential nanoparticle types for delivery, and the advantages and disadvantages of each are discussed.
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Affiliation(s)
- Hanah F. Huber
- Nanotechnology Innovation Center, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (H.F.H.); (S.D.); (C.A.-L.); (J.N.-C.)
| | - Majid Jaberi-Douraki
- 1DATA Consortium and Department of Mathematics, Kansas State University Olathe, Olathe, KS 66061, USA; (M.J.-D.); (X.X.); (N.I.M.G.)
| | - Sarah DeVader
- Nanotechnology Innovation Center, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (H.F.H.); (S.D.); (C.A.-L.); (J.N.-C.)
| | - Cesar Aparicio-Lopez
- Nanotechnology Innovation Center, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (H.F.H.); (S.D.); (C.A.-L.); (J.N.-C.)
| | - Juliet Nava-Chavez
- Nanotechnology Innovation Center, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (H.F.H.); (S.D.); (C.A.-L.); (J.N.-C.)
| | - Xuan Xu
- 1DATA Consortium and Department of Mathematics, Kansas State University Olathe, Olathe, KS 66061, USA; (M.J.-D.); (X.X.); (N.I.M.G.)
| | - Nuwan Indika Millagaha Gedara
- 1DATA Consortium and Department of Mathematics, Kansas State University Olathe, Olathe, KS 66061, USA; (M.J.-D.); (X.X.); (N.I.M.G.)
| | - Natasha N. Gaudreault
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA;
| | - Robert K. Delong
- Nanotechnology Innovation Center, Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (H.F.H.); (S.D.); (C.A.-L.); (J.N.-C.)
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Meyenberg M, Ferreira da Silva J, Loizou JI. Tissue Specific DNA Repair Outcomes Shape the Landscape of Genome Editing. Front Genet 2021; 12:728520. [PMID: 34539755 PMCID: PMC8446275 DOI: 10.3389/fgene.2021.728520] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/05/2021] [Indexed: 12/26/2022] Open
Abstract
The use of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 has moved from bench to bedside in less than 10years, realising the vision of correcting disease through genome editing. The accuracy and safety of this approach relies on the precise control of DNA damage and repair processes to achieve the desired editing outcomes. Strategies for modulating pathway choice for repairing CRISPR-mediated DNA double-strand breaks (DSBs) have advanced the genome editing field. However, the promise of correcting genetic diseases with CRISPR-Cas9 based therapies is restrained by a lack of insight into controlling desired editing outcomes in cells of different tissue origin. Here, we review recent developments and urge for a greater understanding of tissue specific DNA repair processes of CRISPR-induced DNA breaks. We propose that integrated mapping of tissue specific DNA repair processes will fundamentally empower the implementation of precise and safe genome editing therapies for a larger variety of diseases.
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Affiliation(s)
- Mathilde Meyenberg
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Joana Ferreira da Silva
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Joanna I. Loizou
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
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